Water heating system of high-rise buildings

High-rise buildings and sanitary facilities are classified: they are divided into parts - zones of a certain height, separated by technical floors. Equipment and communications are placed on technical floors. In heating, ventilation and water supply systems, the permissible zone height is determined by the value of the hydrostatic water pressure in the lower heating devices or other elements and the possibility of placing equipment, air ducts, pipes and other communications on technical floors.

For a water heating system, the height of the zone, depending on the hydrostatic pressure allowed as a working one for certain types of heating appliances (from 0.6 to 1.0 MPa), should not exceed (with some margin) 55 m when using cast iron and steel appliances (with radiators type MS - 80 m) and 90 m for devices with steel heating pipes.

Within one zone, a water heating system is arranged with water heat supply according to a scheme with independent connection to external heat pipelines, i.e., hydraulically isolated from the external heat network and from other heating systems. Such a system has its own water-to-water heat exchanger, circulation and make-up pumps, and an expansion tank.

The number of zones along the height of the building is determined, like the height of a separate zone, by the allowable hydrostatic pressure, but not for heating devices, but for equipment in heating points located with water heating, usually in the basement. The main equipment of these heating points, namely the usual type of water-to-water heat exchangers and pumps, even made to order, can withstand a working pressure of not more than 1.6 MPa.

This means that with such equipment, the height of the building with hydro-water heating by hydraulically isolated systems has a limit of 150-160 m. In such a building, two (75-80 m high) or three (50-55 m high) ) zone heating systems. In this case, the hydrostatic pressure in the equipment of the heating system of the upper zone, located in the basement, will reach the calculated limit.

In buildings with a height of 160-250 m, water-water heating can be used using special equipment designed for a working pressure of 2.5 MPa. Combined heating can also be implemented if steam is available: in addition to water-water heating in the lower 160 m, in the area above 160 m, steam-water heating is installed.

The coolant steam, characterized by a slight hydrostatic pressure, is supplied to the technical floor under the upper zone, where another heating point is equipped. It installs a steam-water heat exchanger, its own circulation pump and expansion tank, devices for qualitative-quantitative regulation.

Each zone heating system has its own expansion tank, equipped with an electrical signaling system and system feed control.

A similar complex of combined heating operates in the central part of the main building of Moscow State University: in the lower three zones water-water heating with cast-iron radiators is arranged, in the upper zone IV - steam-water heating.

In buildings with a height of more than 250 m, new zones of steam-water heating are provided or they resort to electric water heating if there is no source of steam.

To reduce the cost and simplify the design, it is possible to replace the combined heating of a high-rise building with a single water heating system, which does not require a second primary heat carrier (for example, steam). The building can be equipped with a hydraulically common system with one water-to-water heat exchanger, a common circulation pump and an expansion tank (Fig. 2). The system by building height is still divided into zonal parts according to the above rules. Water is supplied to the second and subsequent zones by zone circulation booster pumps and returns from each zone to a common expansion tank. The necessary hydrostatic pressure in the main return riser of each zone part is maintained by a pressure regulator of the “upstream” type. The hydrostatic pressure in the substation equipment, including booster pumps, is limited by the installation height of the open expansion tank and does not exceed the standard operating pressure of 1 MPa.

The heating systems of high-rise buildings are characterized by their division within each zone along the sides of the horizon (along the facades) and automation of the temperature control of the coolant. The temperature of the water coolant for the zone heating system is set according to a given program, depending on the change in the outside air temperature (regulation "by disturbance"). At the same time, for the part of the system that heats the rooms facing south and west, additional regulation of the temperature of the heat carrier is provided (to save thermal energy) in the case when the temperature of the rooms rises during insolation (regulation "by deviation").

To empty individual risers or parts of the system, drain lines are laid on the technical floors. For the duration of the system, the drainage line is turned off to prevent uncontrolled leakage of water by a common valve in front of the separating drain tank.

Decentralized hot water heating system

Among the water heating systems used, systems prevail in which the surface temperature of the heating devices is limited to 95 °C. Above, we considered common systems where the local coolant is centrally heated by high-temperature water, and it is heated up to a maximum of 95 ° C in two-pipe systems and up to 105 ° C in one-pipe systems. Meanwhile, a system in which high-temperature water would be brought as close as possible to the heating devices, and the temperature of their surface, due to hygienic requirements, was kept low, would have a certain economic advantage over the conventional system. This advantage would be achieved by reducing the diameter of the pipes to move a reduced amount of water at an increased speed under the pressure of the network (station) circulation pump.

In such a combined water-water system, the heat carrier would be heated decentralized. In the heating point of the building, equipment for heating and creating water circulation was not required, only the operation of the system would be controlled there, and the consumption of thermal energy would be taken into account.

Let us analyze some schemes of a system for decentralized heating of a local heat carrier with high-temperature water, developed by Soviet engineers, dividing them into two groups: with independent and dependent connection of the system to external heat pipelines.

Non-pressure steel or ceramic heaters are offered for decentralized heating of local water or oil according to an independent scheme. These devices, like open vessels, are filled with water (oil), heated through the walls of the coil with high-temperature water. Evaporation from the surface of the water in the appliance increases the humidity in the room. The coil is included in a single-pipe flow-controlled system with "inverted" circulation of high-temperature water. High-temperature water can have a temperature of 110°C with ceramic blocks, 130°C with steel appliances filled with mineral oil. In this case, the surface temperature of the devices does not exceed 95 °C.

Decentralized mixing of high- and low-temperature water, i.e. heating of the local coolant according to a dependent scheme, can be carried out in mains, risers and directly in heating devices.

When mixed in the mains, the heating system is divided into several series-connected parts (subsystems), each consisting of several single-pipe U-shaped risers. Associated mixing of high-temperature water with cooled return water from subsystems (to increase the temperature from 70 to 105 °C) occurs through jumpers with diaphragms into intermediate lines between individual subsystems.

In a system with mixing water at the base of single-pipe U-shaped risers, the line with high-temperature water is also single-pipe, unlike known heating systems. The water in it lowers the temperature at the mixing points and enters the risers with different temperatures. In vertical risers, mainly natural circulation of water occurs, since the hydraulic resistance of the closing sections is relatively small.

To mix water at the base of two-pipe risers, special mixers are used 2 . The water in both lines moves under the pressure of the network pump, in the risers there is a natural circulation of water.

With decentralized mixing and single-pipe risers, the heating system is divided into two parts: in the first, high-temperature water moves in the risers from the bottom up, cooling to a temperature of 95 ° C, in the second, from top to bottom. To ensure that the required amount of high-temperature water flows into the devices, diaphragms are installed in the closing sections.

With decentralized mixing in two-pipe risers, high-temperature water is supplied inside each heater through a perforated collector 4 or through a mixing nozzle, and the chilled water is removed in the same amount to the return riser.

The described heating systems have not received mass distribution due to difficulties in laying high-temperature water pipes in rooms, the complexity of installation and operational regulation.

Currently, a direct-flow heating system is used with decentralized heating of water returning from three or four subsystems (groups of risers) connected in series. In this so-called step temperature regeneration (CRT) system (high temperature water heats chilled water in two to three (between subsystems) temperature regenerators (RT). The temperature regenerators are counterflow heat exchangers of the "pipe in pipe" type (for example, a Dy25 pipe in Dy40 case).Water flows twice through each RT; first in the form of high-temperature water through the annular space, then in the form of chilled water through the inner pipe.Water returning from the last subsystem is heated by high-temperature water to 95-105 °C, then it enters the penultimate subsystem and etc., until it returns cooled from the first subsystem to the point of high-temperature water entry into the building.

The SRT heating system is performed as a single-pipe system with one-sided unified instrument assemblies, with an upper or lower distribution of the supply line.

Apartment heating system

The problem of rational consumption and distribution of thermal energy by heating systems is still relevant, because under the climatic conditions of Russia, heating systems for residential buildings are the most energy-intensive of engineering systems.

In recent years, prerequisites have been created for the construction of residential buildings with reduced energy consumption by optimizing urban planning and space-planning decisions, the shape of buildings, by increasing the level of thermal protection of enclosing structures and by using more energy-efficient engineering systems.

Residential buildings built since 2000 with thermal protection corresponding to the second stage of energy saving meet the energy efficiency requirements of countries such as Germany and the UK. The walls and windows of residential buildings have become "warmer" - heat loss by building envelopes has decreased by 2-3 times, modern translucent fences (windows, doors of loggias and balconies) have such low air permeability that with closed windows there is practically no infiltration.

At the same time, in residential buildings of mass construction, heating systems made according to standard designs are still being designed and operated. The systems traditionally use high-temperature coolants with parameters of 105–70, 95–70°C. When providing thermal protection of buildings according to the second stage of energy saving and with the specified parameters of the coolant, the dimensions and heating surface of heating devices are reduced, the coolant flow through each device and, as a result, protection from reverse radiation is not provided in the area of ​​windows, doors of balconies, loggias, working conditions worsen and regulation of automatic thermostats of heating devices.

To create buildings with a more efficient use of thermal energy, providing comfortable conditions for human habitation, modern, energy-efficient heating systems are needed. Adjustable apartment heating systems fully meet these requirements. However, the widespread use of apartment heating systems is held back in part by the lack of sufficient regulatory frameworks and design guidelines.

Currently, the Department of Technical Regulation of the Gosstroy of Russia is considering the Code of Rules "Systems for apartment heating of residential buildings." The set of rules was prepared by a group of specialists from FSUE "SantekhNIIproekt", OJSC "Mosproekt", Gosstroy of Russia and includes requirements for systems, heaters, fittings and pipelines, requirements for safety, durability and maintainability of apartment heating systems.

The set of rules supplements and develops the requirements for the design of apartment heating systems in accordance with SNiP 2.04.05-(2) and can be used to design apartment heating systems in residential buildings of various types, single and multi-apartment, block and sectional in the construction of new and reconstructed buildings provided with thermal energy from thermal networks (CHP, RTS, boiler house), from autonomous or individual heat sources.

Apartment heating system - a system with piping within one apartment, ensuring the maintenance of a given air temperature in the premises of this apartment.

An analysis of a number of projects shows that apartment heating systems have a number of advantages compared to central systems:

Provide greater hydraulic stability of the heating system of a residential building;

Increase the level of comfort in apartments by ensuring the air temperature in each room at the request of the consumer;

Provide the ability to account for heat in each apartment and reduce heat consumption for the heating period by 10-15% with automatic or manual regulation of heat flows;

Satisfy the customer's design requirements (the ability to choose the type of heater, pipes, pipe laying schemes in the apartment);

They provide the possibility of replacing pipelines, shut-off and control valves and heating devices in individual apartments during redevelopment or in emergency situations without violating the operating mode of heating systems in other apartments, the possibility of carrying out adjustment work and hydrostatic tests in a separate apartment.

The level of thermal protection of residential buildings with apartment heating systems must not be lower than the required values ​​​​of the reduced resistance to heat transfer of the external fences of the building in accordance with SNiP II-3-79 *.

The design air temperature for the cold period of the year in the heated premises of a residential building should be taken within the optimal norms in accordance with GOST 30494, but not lower than 20 ° C for premises with a permanent stay of people. In multi-apartment buildings, it is allowed to lower the air temperature in heated rooms when they are not in use (during the absence of the owner of the apartment), lower than the standard by no more than 3–5 ° C, but not lower than 15 ° C. With such a temperature difference, heat loss through the internal enclosing structures may not be taken into account.

In an apartment building with a central heating system, apartment heating systems should be designed for all apartments. It is not allowed to install apartment systems for one or more apartments in the house. Apartment heating systems in a residential building are connected to heating networks according to an independent scheme through heat exchangers, in a quarterly central heating station or in an individual heating point (ITP). It is allowed to connect apartment heating systems to heating networks according to a dependent scheme, while ensuring automatic control of the parameters of the heat carrier in the ITP.

In single-apartment and block houses with individual heat supply sources, both apartment heating systems with heaters and underfloor heating systems for heating individual rooms or floor sections can be used, provided that the set temperature of the coolant and the temperature on the floor surface are automatically maintained.

For apartment heating systems, as a rule, water is used as a heat carrier; other coolants may be used during a feasibility study in accordance with the requirements of SNiP 2.04.05-91*.

The parameters of the coolant for apartment heating systems, depending on the heat source, the type of pipes used and the way they are laid, are given in the table.

In apartment heating systems of a residential building, the parameters of the coolant must be the same for all apartments. In the technical justification or on the instructions of the customer, it is allowed to take the temperature of the heat carrier of the apartment heating system of one of the apartments lower than that adopted for the heating system of the building. At the same time, automatic maintenance of the specified coolant temperature should be ensured.

Heating systems

In buildings with a height of two or more floors, for supplying coolant to apartments, two-pipe systems should be designed with lower or upper wiring of main pipelines, main vertical risers serving part of the building or one section.

The supply and return main vertical risers for each part of the section building are laid in special shafts of common corridors, stair halls. In the shafts on each floor, built-in installation cabinets are provided, in which floor-by-floor distribution manifolds with outlet pipelines for each apartment, shut-off valves, filters, balancing valves, and heat meters should be placed.

Apartment heating systems can be performed according to the following schemes:

Two-pipe horizontal (dead-end or associated) with parallel connection of heating devices (Fig. 1). Pipes are laid near the outer walls, in the floor structure or in special skirting boxes;

Two-pipe beam with individual connection by pipelines (loops) of each heater to the distribution manifold of the apartment (Fig. 2). It is allowed to connect "on the hitch" of two heaters within the same room. Pipelines are laid in the form of loops in the floor structure or along the walls under skirting boards. The system is convenient for installation, since pipelines of the same diameter are used, there are no pipe connections in the floor;

Single-pipe horizontal with closing sections and serial connection of heating devices (Fig. 3). The consumption of pipes is significantly reduced, but the heating surface of heating devices is increased by approximately 20% or more. The circuit is recommended for use with higher coolant parameters and a smaller temperature difference (for example, 90–70°C). By increasing the amount of water flowing into the device, the heating surface of the device decreases. The calculated temperature of the water leaving the last appliance must not be lower than 40°C;

Floor-standing with laying heating coils from pipes in the floor structure. Floor systems have a greater inertia than systems with heating devices, are less accessible for repair and dismantling. Possible options for laying pipes in underfloor heating systems are shown in fig. 4, 5. Scheme according to fig. 4 ensures easy installation of pipes and uniform temperature distribution over the floor surface. The scheme according to fig. 5 provides approximately equal average temperature on the floor surface.

Bathroom heated towel rails are connected to the hot water supply system - when the building is supplied from heating networks or from an autonomous source, or to the heating system - with an individual heat source.

In residential buildings with more than three floors, with a central or general autonomous source of heat supply, it is necessary to design the heating of stairwells, stairwells and elevator lobbies. In buildings with more than three floors, but not more than 10, as well as in buildings of any number of floors with individual heat sources, it is allowed not to design the heating of smoke-free staircases of the first type. In this case, the heat transfer resistance of the internal walls that enclose the unheated staircase from the living quarters is taken equal to the heat transfer resistance of the outer walls.

Hydraulic calculations of apartment heating systems are carried out according to existing methods, taking into account recommendations for the use and selection of heating devices, developed on the basis of the results of the Research Institute of Sanitary Engineering when testing and certifying heating devices from various manufacturers.

The connection of the heater to pipelines can be carried out according to the following schemes:

Lateral one-way connection;

Radiator connection from below;

Lateral double-sided (versatile) connection to the lower radiator plugs. Versatile connection of pipelines should be provided for radiators with a length of not more than 2,000 mm, as well as for radiators connected “on a hitch”. In a two-pipe heating system, it is allowed to connect two heaters “on a hitch” within the same room.

In apartment heating systems, as in traditional heating systems, heaters, valves, fittings, pipes and other materials approved for use in construction and having certificates of conformity of the Russian Federation should be used.

In multi-apartment residential buildings, the service life of heating devices and pipelines of heating systems must be at least 25 years; in single-family houses, the service life is taken at the request of the customer.

As heating devices, it is advisable to use steel radiators or other devices with a smooth surface that cleans the surface from dust. It is allowed to use convectors with air control valves.

To regulate the heat flow in the premises, control valves should be installed near the heating devices. As a rule, automatic temperature controllers (with built-in or remote thermostatic elements) are installed in rooms with permanent residence of people, which ensure the maintenance of the set temperature in each room and save heat supply through the use of internal heat surpluses (domestic heat emissions, solar radiation).

For hydraulic balancing of individual branches of the apartment two-pipe heating system, valves with pre-setting are installed for all heating devices in the apartment.

For the hydraulic stability of the heating system of the building, it is planned to install balancing valves on the main vertical risers for each part of the building, section, and also at each floor distribution manifold.

In buildings with apartment heating systems, the following should be provided:

Installation in the ITP of a closed expansion tank and a filter for the building system with heat supply from heat networks and an autonomous heat source;

Installation of a closed expansion tank and a filter for each apartment with heat supply from an individual heat source.

With open expansion tanks, the water in the system is saturated with air, which significantly activates the process of corrosion of the metal elements of the system, and air plugs form in the system.

The pipelines of the apartment heating system can be made of steel, copper, heat-resistant polymer or metal-polymer pipes. In heating systems with pipelines made of polymer or metal-polymer pipes, the coolant parameters (temperature and pressure) should not exceed the maximum allowable values ​​specified in the technical documentation for their manufacture. When choosing the parameters of the coolant, it should be taken into account that the strength of polymer and metal-polymer pipes depends on the operating temperature and pressure of the coolant. With a decrease in the temperature and pressure of the coolant below the maximum allowable values, the safety factor and, accordingly, the service life of the pipes increase. Pipelines of apartment heating systems, as a rule, are laid hidden: in strobes, in the floor structure. Open laying of metal pipelines is allowed. In the case of hidden laying of pipelines at the locations of collapsible connections and fittings, hatches or removable shields should be provided for inspection and repair.

When calculating heating devices in each room, at least 90% of the incoming heat from pipelines passing through the room should be taken into account. Heat losses due to cooling of the coolant in uninsulated openly laid horizontal pipelines are accepted according to reference data. The heat flow of openly laid pipes is taken into account within:

90% with horizontal pipe laying near the floor;

70–80% when laying horizontal pipes under the ceiling;

85–90% for vertical pipe laying.

Thermal insulation is provided for pipelines laid in the grooves of external walls, in mines and in unheated premises, in floor areas with close placement of four or more pipes in the floor, ensuring an acceptable temperature on the surface.

Accounting for heat energy consumption

Apartment heating systems, on the one hand, provide the most comfortable living conditions that satisfy the consumer, and on the other hand, they allow you to regulate the heat output of heating devices in the apartment, taking into account the mode of residence of the family in the apartment, the need to reduce the cost of paying for heating, etc.

In a building with apartment heating systems, it is planned to account for the heat consumption of the building as a whole, as well as separately for each apartment and public and technical premises located in this building.

To account for the heat consumption of each apartment, the following can be provided: heat consumption meters for each apartment system; heat distributors of evaporative or electronic type on each heater; heat consumption meter at the entrance to the building. With any type of heat metering devices, the tenant's payment should include the total heat costs for the building (heating of staircases, elevator lobbies, service and technical premises).

In buildings with increased thermal protection of building envelopes, apartment heating systems (with automatic thermostats for heating devices and heat consumption meters both at the entrance to the building and for each apartment) create additional opportunities and incentives for more efficient use of thermal energy. Thanks to the automatic control of the heat output of heating devices when the heat load in the premises changes and the ability of residents to regulate the heat output of heating devices, taking into account the mode of residence of the family (reducing the air temperature in the premises during the absence of residents, reducing heat losses), savings in heat energy from 20 to 30% can be achieved. At the same time, consumers' payment for heat will decrease, since the established norms for the consumption of heat energy significantly exceed the actual consumption.

Hydraulic calculation of the water heating system. Methods for hydraulic calculation of a water heating system. Calculation by specific linear pressure loss; calculation according to the characteristics of resistance and conductivity; calculation by lengths and dynamic pressures. - 1 hour.

Loss of pressure in the network.

The movement of fluid in heat pipelines occurs from a section with a high pressure to a section with a lower pressure due to the pressure difference. When moving a liquid, potential energy is consumed, i.e., hydrostatic pressure to overcome resistance from friction against the walls of pipes and from turbulence and shock when changing the speed and direction of movement in fittings, devices and fittings.

The pressure drop due to frictional resistance against the pipe walls is a linear loss; the pressure drop caused by local resistances is a local loss.

The pressure drop Ap, Pa, caused by friction and local resistances, is measured in fractions of the dynamic pressure and is expressed by a formula known from the course of hydraulics

If, when calculating heating systems, we take the density of the coolant (liquid) constant, which leads to an error that lies outside the practical accuracy of the calculation, then the values ​​\u200b\u200bcan be determined as constants for a heat pipe of a given diameter.

Using a constant ratio in calculations - allows you to determine the coolant velocity by dividing the flow rate by this value by a given coolant flow rate and the diameter of the heat pipe; the use of a constant value makes it possible to determine the pressure loss in the heat pipeline at a given flow rate, bypassing the determination of the velocity.

Hydraulic calculation of water heating systems.

Pipelines in the heating system perform an important function of distributing the coolant to individual heaters. They are heat conductors, the task of which is to transfer a certain calculated amount of heat to each device.

The heating system is a highly branched and complex looped network of heat pipelines, each section of which must carry a certain amount of heat. Performing an accurate calculation of such a network is a complex hydraulic task associated with solving a large number of nonlinear equations. In engineering practice, this problem is solved by the selection method.

In water systems, the amount of heat brought by the coolant depends on its flow rate and the temperature drop when the water is cooled in the device. Usually, when calculating, they set the temperature drop of the coolant common for the system and strive to ensure that this drop is maintained in two-pipe systems - for all devices and the system as a whole; in one-pipe systems - for all risers. With a known temperature drop of the coolant through the heat pipes of the system, a calculated water flow must be supplied to each heater.

With this approach, to perform a hydraulic calculation of the heating network of the heating system means (taking into account the available circulation pressure) to select the diameters of individual sections in such a way that the calculated flow rate of the coolant passes through them. The calculation is carried out by selecting diameters according to the existing range of pipes, so it is always associated with some error. Certain discrepancies are allowed for various systems and individual elements.

In contrast to the method discussed above, at the present time, in relation to the calculation of one-pipe heating systems, the method with a variable water temperature drop in the risers, proposed by A. I. Orlov in 1932, has found wide distribution.

The principle of the calculation is that the water flow rates in the risers are not set in advance, but are determined in the process of hydraulic calculation based on the full linkage of pressures in all rings of the system and the accepted diameters of the heat pipes of the network. The temperature drop of the coolant in the individual risers is different - variable. The area of ​​the heat-releasing surface of the heating devices is determined by the temperature and water flow determined by the hydraulic calculation. The calculation method with a variable temperature difference more accurately reflects the actual picture of the system operation, eliminates the need for mounting adjustment, facilitates the unification of the pipe billet, as it makes it possible to avoid the use of various combinations of diameters of radiator assemblies and composite risers. This method became widespread after, in 1936, G.I. Fikhman proved the possibility of using the averaged values ​​of friction coefficients in the calculation of heat pipelines of water heating systems and conducting the entire calculation according to a quadratic law.

General instructions for calculating the water heating system

The artificial pressure Arn created by the pump is taken:

a) for dependent heating systems connected to heating networks through elevators or mixing pumps, based on the available pressure difference at the inlet and the mixing ratio;

b) for independent heating systems connected to heat networks through heat exchangers or to boiler rooms without the prospect of connecting to heat networks, based on the maximum allowable speed of water movement in heat pipelines, the possibility of linking pressure loss in the circulation rings of systems and technical and economic calculations.

Focusing on the value of the average specific linear pressure loss Rcr, first determine the preliminary, and then (taking into account the loss due to local resistance) the final diameters of the heat pipes.

The calculation of heat pipelines begins with the main most unfavorable circulation ring, which should be considered:

a) in a pumping system with a dead-end movement of water in the mains - a ring through the most loaded and remote from the heating point riser;

b) in a pumping system with associated water movement - a ring through the middle most loaded riser;

c) in the gravitational system - a ring, in which, depending on the available circulation pressure, the value of Rсp will be the smallest.,

The linkage of pressure losses in the circulation rings should be made taking into account only those areas that are not common to the compared rings.

The discrepancy (discrepancy) in the calculated pressure losses in parallel-connected sections of individual rings of the system is allowed for dead-end water movement up to 15%, for associated water movement in mains ± 5%.

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An apartment in a high-rise building is an urban alternative to private houses, and a very large number of people live in apartments. The popularity of city apartments is not strange, because they have everything a person needs for a comfortable stay: heating, sewerage and hot water supply. And if the last two points do not need special introduction, then the heating scheme of a multi-storey building requires detailed consideration. From the point of view of design features, the centralized one has a number of differences from autonomous structures, which allows it to provide the house with thermal energy in the cold season.

Features of the heating system of apartment buildings

When installing heating equipment in multi-storey buildings, it is imperative to comply with the requirements established by the regulatory documentation, which includes SNiP and GOST. These documents state that the heating structure should provide a constant temperature in the apartments within the range of 20-22 degrees, and the humidity should vary from 30 to 45 percent.

Despite the existence of standards, many houses, especially old ones, do not meet these indicators. If this is the case, then first of all you need to deal with the installation of thermal insulation and change the heating devices, and only then contact the heat supply company. The heating of a three-story house, the scheme of which is shown in the photo, can be cited as an example of a good heating scheme.

To achieve the required parameters, a complex design is used that requires high-quality equipment. When creating a project for the heating system of an apartment building, specialists use all their knowledge to achieve an even distribution of heat in all sections of the heating main and create a comparable pressure on each tier of the building. One of the integral elements of the work of such a design is the work on a superheated coolant, which provides for the heating scheme of a three-story house or other skyscrapers.

How it works? Water comes directly from the thermal power plant and is heated to 130-150 degrees. In addition, the pressure is increased to 6-10 atmospheres, so the formation of steam is impossible - high pressure will drive water through all floors of the house without loss. The temperature of the liquid in the return pipeline in this case can reach 60-70 degrees. Of course, at different times of the year, the temperature regime can change, since it is directly related to the ambient temperature.

Purpose and principle of operation of the elevator unit

It was said above that the water in the heating system of a multi-storey building is heated to 130 degrees. But consumers do not need such a temperature, and it is absolutely pointless to heat the batteries to such a value, regardless of the number of floors: the heating system of a nine-story building in this case will not differ from any other. Everything is explained quite simply: the heating supply in multi-storey buildings is completed by a device that goes into the return circuit, which is called an elevator unit. What is the meaning of this node, and what functions are assigned to it?

The coolant heated to a high temperature enters, which, according to the principle of its operation, is similar to a dosing injector. It is after this process that the liquid carries out heat exchange. Leaving through the elevator nozzle, the high-pressure coolant exits through the return line.

In addition, through the same channel, the liquid enters the heating system for recirculation. All these processes together make it possible to mix the coolant, bringing it to the optimum temperature, which is sufficient to heat all apartments. The use of an elevator node in the scheme allows you to provide the highest quality heating in high-rise buildings, regardless of the number of storeys.

Design features of the heating circuit

There are different valves in the heating circuit behind the elevator unit. Their role cannot be underestimated, since they make it possible to regulate heating in individual entrances or in the whole house. Most often, the adjustment of the valves is carried out manually by employees of the heat supply company, if such a need arises.

In modern buildings, additional elements are often used, such as collectors, thermal and other equipment. In recent years, almost every heating system in high-rise buildings is equipped with automation to minimize human intervention in the operation of the structure (read: ""). All the described details allow to achieve better performance, increase efficiency and make it possible to distribute heat energy more evenly throughout all apartments.

Piping in a multi-storey building

As a rule, in multi-storey buildings, a single-pipe wiring diagram with top or bottom filling is used. The location of the forward and return pipes can vary depending on many factors, including even the region where the building is located. For example, the heating scheme in a five-story building will be structurally different from heating in three-story buildings.

When designing a heating system, all these factors are taken into account, and the most successful scheme is created that allows you to bring all the parameters to the maximum. The project may involve various options for filling the coolant: from the bottom up or vice versa. In individual houses, universal risers are installed, which ensure the rotation of the movement of the coolant.

Types of radiators for heating apartment buildings

In multi-storey buildings, there is no single rule that allows the use of a specific type of radiator, so the choice is not particularly limited. The heating scheme of a multi-storey building is quite versatile and has a good balance between temperature and pressure.

The main models of radiators used in apartments include the following devices:

1. Cast iron batteries. Often used even in the most modern buildings. They are cheap and very easy to install: as a rule, apartment owners install this type of radiator on their own.
2. Steel heaters. This option is a logical continuation of the development of new heating devices. Being more modern, steel heating panels demonstrate good aesthetic qualities, are quite reliable and practical. Very well combined with the regulating elements of the heating system. Experts agree that it is steel batteries that can be called optimal when used in apartments.
3. Aluminum and bimetallic batteries. Products made of aluminum are very much appreciated by the owners of private houses and apartments. Aluminum batteries have the best performance compared to previous options: excellent external data, low weight and compactness are perfectly combined with high performance. The only disadvantage of these devices, which often scares off buyers, is the high cost. Nevertheless, experts do not recommend saving on heating and believe that such an investment will pay off pretty quickly.

Conclusion

It is also not recommended to carry out repair work in the heating system of an apartment building on your own, especially if it is heating in the walls of a panel house: practice shows that residents of houses, without having the appropriate knowledge, are able to throw away an important element of the system, considering it unnecessary.

Centralized heating systems demonstrate good qualities, but they need to be constantly maintained in working order, and for this you need to monitor many indicators, including thermal insulation, equipment wear and regular replacement of spent parts.

Description:

The buildings considered in the book can be classified as high-rise buildings. We hope that in the future there will be a book about domestic experience in designing engineering equipment for ultra-tall buildings, figuratively called skyscrapers.

Heat supply and heating of high-rise residential buildings

To the publication of the book

V. I. Livchak, Vice-President of NP AVOK, Head of Energy Efficiency in Construction at Mosgosexpertiza

In Moscow, half a century after the construction of seven "Stalinist" skyscrapers, the construction of high-rise buildings resumed. Now buildings above 40 floors have been built: in 2003 - "Edelweiss" on Davydkovskaya St., vl. 3 (height 176 m, 43 floors), "Scarlet Sails" building 4 (179 m, 48 floors) on Aviation Street, vl. 77–79; in 2004 - "Vorobyovy Gory" (188 m, 49 floors) on Mosfilmovskaya st., vl. 4-6, "Triumph Palace" - the highest residential building in Europe (225 m, 59 floors, with a spire - 264 m), Chapaevsky lane, vl. 2.

Several dozens of buildings with a height of 30-50 floors are planned for construction under the city's investment program "The New Ring of Moscow". A number of skyscrapers over 300 meters high are being built in the Moscow City business center, and the apotheosis of everything is the construction of the Rossiya Tower, 600 meters high, designed by the English architect Norman Foster, the design of which began in 2006.

The project of the residential building "Edelweiss" was carried out by TsNIIEPzhilischa, the engineering part of the other listed high-rise residential buildings built by the company "DON-stroy" was the fruit of the creativity of the design and production company "Alexander Kolubkov" under the leadership of A. N. Kolubkov and bearing his name. It is also interesting that DON-Stroy itself operates the houses it builds, and therefore the applied solutions are confirmed by the practice of their work.

The experience gained in the design of these buildings and their operation was the basis of the book "Engineering equipment of high-rise buildings", published by "ABOK-PRESS" in 2007 under the general editorship of prof. Moscow Architectural Institute M. M. Brodach.

In our opinion, all buildings by height can be divided into 5 categories:

Up to five floors where installation of elevators is not required - low-rise buildings;

Up to 75 m (25 floors), within which vertical zoning for fire compartments is not required - multi-storey buildings;

76–150 m - high-rise buildings;

151–300 m - high-rise buildings;

Over 300 m - ultra-tall buildings.

The gradation is a multiple of 150 m due to a change in the calculated outdoor temperature for the design of heating and ventilation - every 150 m it decreases by 1 °C.

The design features of buildings above 75 m are due to the fact that they must be vertically divided into hermetic fire compartments (zones), the boundaries of which are enclosing structures that provide the required fire resistance limits for localizing a possible fire and preventing it from spreading to adjacent compartments. The height of the zones should be 50–75 m, and it is not necessary to separate vertical fire compartments with technical floors, as is customary in warm countries, where technical floors do not have walls and are used to collect people in case of fire and their subsequent evacuation. In countries with a harsh climate, the need for technical floors is due to the requirements for the placement of engineering equipment. When it is installed in the basement, only part of the floor located at the border of fire compartments can be used to place smoke protection fans, the rest - for working rooms. With a cascade connection scheme for heat exchangers, as a rule, they, together with pumping groups, are placed on technical floors, where they need more space, and occupy the entire floor, and sometimes two floors in ultra-tall buildings.

The buildings considered in the book can be classified as high-rise buildings. We hope that in the future there will be a book about domestic experience in designing engineering equipment for ultra-tall buildings, figuratively called skyscrapers.

Below, an analysis of design solutions for heat and water supply and heating of the listed residential buildings will be given. And this is only a part of the subject to which this book is devoted, beyond the scope of this article is the analysis of advanced solutions implemented in a number of foreign high-rise buildings, and the features of the influence of the outdoor climate, experience in designing ventilation and air conditioning systems for residential and public buildings, fire safety systems, water disposal and waste disposal, automation and dispatching, also given in the book "Engineering Equipment for High-Rise Buildings".

Heat supply

A feature of the design of heat and water supply systems is that all pumping and heat exchange equipment of the considered high-rise residential buildings is located at ground level or minus the first floor. This is due to the danger of placing overheated water pipelines on residential floors, the lack of confidence in the sufficiency of protection against noise and vibration of adjacent residential premises during the operation of pumping equipment, and the desire to save a scarce area to accommodate more apartments.

Such a solution is possible due to the use of high-pressure pipelines, heat exchangers, pumps, shut-off and control equipment that can withstand operating pressures up to 25 atm. Therefore, in the piping of heat exchangers from the side of local water, butterfly valves with collar flanges, pumps with a U-shaped element, pressure regulators “to themselves” of direct action installed on the make-up pipeline, electromagnetic valves rated for a pressure of 25 atm are used. at the filling station for heating systems.

With a building height above 220 m, due to the occurrence of ultra-high hydrostatic pressure, it is recommended to use a cascade connection scheme for zone heat exchangers for heating and hot water supply, an example of such a solution is given in the book.

Another feature of the heat supply of the implemented high-rise residential buildings is that in all cases the source of heat supply is the city heat networks. Connection to them is made through the central heating station, which occupies a rather large area, for example, in the Vorobyovy Gory complex, it occupies 1,200 m 2 with a room height of 6 m (rated power 34 MW).

The CHP includes heat exchangers with circulation pumps for heating systems of different zones, heat supply systems for ventilation and air conditioning heaters, hot water supply systems, pumping stations for filling heating systems and pressure maintenance systems with expansion tanks and automatic control equipment, emergency electric hot water storage water heaters. Equipment and pipelines are arranged vertically so that they are easily accessible during operation. A central passage with a width of at least 1.7 m passes through all the central heating stations for the possibility of moving special loaders, which make it possible to remove heavy equipment when it is replaced (Fig. 1).

Picture 1.

This decision is also due to the fact that high-rise complexes, as a rule, are multifunctional in purpose with a developed stylobate and underground part, on which several buildings can be located. Therefore, in the Vorobyovy Gory complex, which includes 3 high-rise residential buildings of 43-48 floors and 4 buildings of 17-25 floors, united by a five-level stylobate part, technical collectors with numerous pipelines depart from this single central heating station, and to reduce them in the technical In the zone of high-rise buildings, booster pumping stations for water supply were located, which pump cold and hot water into each zone of high-rise buildings.

Another solution is also possible - the central heating station is used to introduce urban heat networks to the facility, place a pressure drop regulator "after itself", a heat energy metering unit and, if necessary, a cogeneration unit and can be combined with one of the individual local heating points (ITP), serving to connect local heat consumption systems close in location to this heating point. From this CHP, superheated water is supplied through two pipes, and not through several from the comb, as in the previous case, to local ITPs located in other parts of the complex, including on the upper floors, according to the principle of proximity to the heat load. With this solution, there is no need to connect the internal heat supply system of the supply air heaters according to an independent scheme through a heat exchanger. The heater itself is a heat exchanger and is connected directly to the superheated water pipelines with pumping to improve the quality of load control and increase the reliability of the protection of heaters from freezing.

One of the solutions for redundant centralized heat and power supply of high-rise buildings can be the installation of autonomous mini-CHPs based on gas turbine (GTP) or gas piston (GPU) plants that simultaneously produce both types of energy. Modern means of protection against noise and vibration make it possible to place them directly in the building, including on the upper floors. As a rule, the power of these units does not exceed 30-40% of the maximum required power of the facility, and in the normal mode these units operate, supplementing the centralized power supply systems. With a higher capacity of cogeneration plants, problems arise in transferring excesses of one or another energy carrier to the network.

The book provides an algorithm for calculating and selecting a mini-CHP when the object is supplied with offline power and an analysis of optimizing the choice of a mini-CHP using the example of a specific project. With a shortage of only thermal energy for the object under consideration, an autonomous heat supply source (AHS) in the form of a boiler room with hot water boilers can be taken as a source of heat supply. Attached, located on the roof or protruding parts of the building, or stand-alone boiler rooms designed in accordance with SP 41-104-2000 can be used. The possibility and location of AIT should be linked to the whole complex of its impact on the environment, including on a residential high-rise building.

Heating

Water heating systems of high-rise buildings are zoned in height and, as already mentioned, if fire compartments are separated by technical floors, then the zoning of heating systems, as a rule, coincides with fire compartments, since technical floors are convenient for laying distribution pipelines. In the absence of technical floors, the zoning of heating systems may not coincide with the division of the building into fire compartments. Fire authorities allow crossing the boundaries of fire compartments with pipelines of water-filled systems, and the height of the zone is determined by the value of the allowable hydrostatic pressure for the lower heaters and their piping.

Initially, the design of zonal heating systems was carried out as for ordinary multi-storey buildings. As a rule, two-pipe heating systems with vertical risers and lower wiring of the supply and return lines passing through the technical floor were used, which made it possible to turn on the heating system without waiting for the construction of all floors of the zone. Such heating systems were implemented in the residential complexes "Scarlet Sails", "Vorobyovy Gory", "Triumph Palace". Each riser is equipped with automatic balancing valves to ensure automatic distribution of the coolant among the risers, and each heater is equipped with an automatic thermostat with increased hydraulic resistance to provide the tenant with the opportunity to set the desired air temperature in the room and minimize the influence of the gravitational component of the circulation pressure and turn on / off thermostats on other heaters connected to this riser.

Further, in order to avoid unbalancing the heating system associated with the unauthorized removal of thermostats in individual apartments, which has repeatedly occurred in practice, it was proposed to switch to a heating system with an upper distribution of the supply line with an associated movement of the coolant along the risers. This equalizes the pressure losses of the circulation rings through the heating devices, regardless of which floor they are located on, increases the hydraulic stability of the system, guarantees the removal of air from the system and facilitates the setting of thermostats.

However, later, as a result of analyzing various solutions, the designers came to the conclusion that the best heating system, especially for buildings without technical floors, are systems with flat-by-apartment horizontal wiring connected to vertical risers, which, as a rule, pass through the stairwell and are made according to two-pipe scheme with lower wiring. Such a system was designed in the crowning part (9 floors of the third zone) of the Triumph Palace high-rise complex and in a 50-storey building under construction without intermediate technical floors on the street. Pyreva, 2.

Apartment heating systems are equipped with a unit with shut-off valves, regulating valves and drain fittings, filters and a heat energy meter. This node should be located outside the apartment in the stairwell for unhindered access to the maintenance service. In apartments over 100 m 2, the connection is made not by a loop laid along the perimeter of the apartment (since the diameter of the pipeline increases with increasing load, and as a result, installation becomes more complicated and the cost increases due to the use of expensive large fittings), but through an intermediate apartment distribution cabinet, in which the comb is installed, and from it the coolant is directed by pipelines of smaller diameter to the heaters according to the radial scheme according to the radiant scheme according to the two-pipe scheme.

Pipelines are used from heat-resistant polymeric materials, as a rule, from cross-linked PEX polyethylene (the justification for its use is given in the book), the laying is carried out in the preparation of the floor. The design parameters of the coolant, based on the technical conditions for such pipelines, are 90–70 (65) ° С for fear that a further decrease in temperature leads to a significant increase in the heating surface of heating devices, which is not welcomed by investors due to the increase in the cost of the system. The experience of using metal-plastic pipes in the heating system of the Triumph Palace complex was considered unsuccessful. During operation, as a result of aging, the adhesive layer is destroyed and the inner layer of the pipe “collapses”, as a result of which the flow area narrows and the heating system stops working normally.

The authors of the book believe that for apartment-by-apartment wiring, the best solution is to use automatic balancing valves ASV-P (PV) on the return pipeline and shut-off and measuring valves ASV-M (ASV-1) on the supply pipeline. The use of this pair of valves makes it possible not only to compensate for the influence of the gravitational component, but also to limit the flow to each apartment in accordance with the parameters. Valves are usually selected according to the diameter of the pipelines and adjusted to maintain a pressure drop of 10 kPa. This valve setting is selected based on the required pressure loss on the radiator thermostats to ensure their optimal operation. The flow limit per apartment is set by the setting on the ASV-1 valves, taking into account that in this case the pressure losses on these valves must be included in the differential pressure maintained by the ASV-PV regulator.

The use of apartment horizontal heating systems compared to a system with vertical risers leads to a reduction in the length of the main pipelines (they only fit the stair riser, and not to the most remote riser in the corner room), reduce heat losses from pipelines, simplify the floor-by-floor commissioning of the building and increase hydraulic stability of the system. The cost of installing an apartment system is not much different from standard ones with vertical risers, however, the service life is higher due to the use of pipes made of heat-resistant polymer materials.

In apartment heating systems, it is much easier and with absolute visibility for residents to carry out heat energy metering. We must agree with the opinion of the authors that although the installation of heat meters is not an energy-saving measure, however, payment for the actually consumed thermal energy is a powerful incentive that makes residents take care of its expenditure. Naturally, this is achieved, first of all, by the obligatory use of thermostats on heating appliances. The experience of their operation has shown that in order to avoid affecting the thermal regime of adjacent apartments, the thermostat control algorithm should be limited to lowering the temperature in the room they serve at least 15-16 ° C, and heaters should be selected with a power margin of at least 15%.

Water supply

To improve the reliability of water supply in buildings up to 250 m, at least two inputs from independent water supplies (separate lines of the external ring water supply network) are provided, with a higher height, each input is laid in two lines, each of which must be designed for a pass of at least 50% of the calculated expense.

In order to increase reliability and ensure uninterrupted operation of hot water supply in all high-rise residential buildings, in addition to high-speed hot water heaters, the installation of capacitive electric water heaters is provided, which are turned on during a shutdown of the heating network for scheduled maintenance or accidents. The volume of these backup water heaters is selected based on the one and a half hour peak consumption of hot water. The power of the heating element is assigned in such a way that the heating time for a given volume of water is 8 hours - this is the interval between the peak morning and evening water intakes.

As a rule, there are a lot of backup electric water heaters (there are objects where their number reaches 13 units), and for the stability of their operation, the water heaters should be turned on according to the scheme with associated water movement. If the water heater is the first to connect hot water, it should be the last one to supply heated water. The operating pressure of electric water heaters does not exceed 7 atm. This determines the height of the zone of water supply systems. Therefore, it is not necessary that the number of zones in water supply systems coincide with heating. So, in a 50-storey residential building on the street. Pyriev, there are 3 vertical zones for the heating system and 4 for hot and cold water supply (Fig. 2). For the latter systems, the number of zones is the same to enable redundancy between them.

Figure 2 () Zoning of engineering systems

Another feature of the hot water supply system of the listed high-rise buildings is that, regardless of the number of zones, a single heat exchanger is installed for the entire system, and then hot water is pumped into the corresponding zone by separate booster pumping stations. Also, for cold water, there are their own booster pumping stations for each zone, which increases the reliability of the water supply system, allowing in emergency situations to supply water through hot water pipelines.

The circulation pipelines of different zones are connected to a common comb through a unit that includes, in addition to shut-off valves and a check valve, a downstream pressure regulator and a flow regulator. This scheme was adopted after a lot of trial and error. Electric control valves were installed first. During operation, it turned out that their response speed is not enough for normal operation. It was necessary to find equipment capable of responding more quickly to changes in pressure in the circulation pipeline. As a result, direct acting pressure regulators were chosen. Initially, they were delivered without flow regulators, but since the circulation pumps contribute to airing, these pressure regulators began to work like chokes with unacceptable noise. To eliminate this defect, they tried to adjust the system more carefully, but then they installed flow regulators, after which the described effect disappeared.

So that a change in pressure in the city water supply does not affect the stability of maintaining pressure by pumping stations, a pressure regulator "after itself" is installed at the inlet of the water supply. If before the installation of this regulator, the pressure spread was 0.6–0.9 atm., Then after installation it stabilized at the level of 0.2–0.4 atm. At the hot water supply inlet (after the heat exchangers, in front of the pumping station of each zone), their own pressure regulators “after themselves” are also installed, thanks to which false operation of check valves and the inclusion of standby pumps without special need are excluded.

The water supply system, as a rule, is organized with horizontal apartment wiring. Such a solution has been successfully implemented in the high-rise residential complexes "Vorobyovy Gory", "Triumph Palace" and on the street. Pyriev. In this case, the risers of the water supply system are laid in the stair-lift hall, from where hot and cold water pipelines are supplied to the apartment. The system is equipped with cold and hot water meters, which, together with filters and pressure regulators, are installed in distribution cabinets in the stair-lift hall. In order to avoid the overflow of water (from a cold main to a hot one and vice versa) resulting from improper operation of plumbing equipment, check valves are installed at the inlets to apartments on the supply pipelines of cold and hot water.

Piping from risers to apartments and in apartments is made of cross-linked polyethylene pipes (PEX-pipes). In apartments, it is advisable to use collector wiring, when water is supplied to each water tap from the collector through a separate pipe, this minimizes the influence of neighboring devices on each other (when one mixer is turned on, the spout temperature on the other changes). The risers are laid from steel pipes, and just like in the heating system, hot water risers are equipped with compensators and fixed supports. Estimated circulation in the amount of 40% of the calculated water intake is set using control and balancing valves.

With horizontal wiring of the hot water supply system, you can refuse to install heated towel rails. Operating experience has shown that even in buildings equipped with heated towel rails, up to 70% of apartment owners do not use them. They either leave the bathroom without towel warmers at all, or use electric heated towel rails. The use of electric heated towel rails, from the point of view of the owner of the apartment, is more convenient, since it turns on only as needed.

These are the solutions for the systems of heat supply and heating of the tallest residential buildings built to date in Moscow. They are clear, logical and do not fundamentally differ from the solutions used in the design of conventional multi-storey buildings with a height of less than 75 m, with the exception of the division of heating and water supply systems into zones. But within each zone, standard approaches to the implementation of these systems remain. Greater attention is paid to the installations for filling heating systems and maintaining pressure in them and on each floor of water supply systems, as well as in circulation lines from different zones before connecting them to a common comb, automatic control of heat supply and distribution of the coolant to implement comfortable and economical modes, redundancy operation of equipment to ensure uninterrupted supply of consumers with heat and water.

A distinctive feature is the use of emergency capacitive electric water heaters for an hour and a half supply of water for the purposes of uninterrupted supply of hot water. But it seems that their potential is not being fully utilized. In addition to turning them on in case of an accident or scheduled preventive maintenance of heating networks, they could be tied in such a way that their capacity is used to relieve peak heat loads on the heat supply system.

This ingenious scheme, proposed by A. V. Khludov, the progenitor of hot water supply technology, includes a water heater, a storage tank and a pump that performs the function of charging the tank with hot water (Fig. 3). When the accumulator is charged, cold water flows in parallel flows into the water heater and into the accumulator tank, displacing hot water from the accumulator upwards into the consumer system. Thus, with a large drawdown, the consumer receives hot water from the water heater and accumulator into his system. With a decrease in water intake, the pump squeezes out the excess of water heated in the water heater into the storage tank, thereby displacing cold water from the bottom of the battery into the water heater, i.e., the battery is charging. This allows you to equalize the load on the water heater and reduce its heating surface.

The disadvantages of the adopted solutions include ignoring the use of energy-saving solutions, such as partial replacement of energy demand through the use of autonomous energy-producing gas turbine or gas piston units, solar photovoltaic or water heating elements, heat pumps using low-potential ground energy, ventilation emissions. It should also be noted the insufficient use of centralized refrigeration to increase the comfort of living in apartments and eliminate the negative impact on the architecture of the building of the external blocks of split systems randomly hung on the facade. High-rise buildings, being advanced in terms of architectural and structural solutions, should be an example of the implementation of promising technologies in engineering systems.

Currently, the vast majority of existing residential multi-storey buildings in our country are heated mainly by vertical single-pipe water heating systems. The advantages and disadvantages of such systems are noted in other sources. Among the main shortcomings, the following should be noted:

□ it is impossible to account for heat consumption for heating each apartment;

□ it is impossible to pay for heat consumption for actually consumed heat energy (TE);

□ it is very difficult to maintain the required air temperature in each apartment.

Therefore, we can conclude that it is necessary to abandon the use of vertical systems for heating residential multi-storey buildings and use apartment heating systems (CO), as recommended. At the same time, it is necessary to install a heat meter in each apartment.

Apartment-specific SS in multi-storey buildings are systems that can be serviced by residents of an apartment without changing the hydraulic and thermal regimes of neighboring apartments and provide apartment-by-apartment accounting for heat consumption. This increases the thermal comfort in residential premises and saves heat for heating. At first glance, these are two contradictory tasks. However, there is no contradiction here, because overheating of the premises is eliminated due to the absence of hydraulic and thermal misalignment of CO. In addition, the heat of solar radiation and household heat inputs to each apartment are used 100%. The urgency of solving this problem is realized by builders and maintenance services. Existing apartment heating systems in our country are rarely used for heating multi-storey buildings for various reasons, including their low hydraulic and thermal stability. The apartment heating system, protected by the current patent of the Russian Federation No. 2148755 F24D 3/02, according to the authors, meets all the requirements. On fig. 1 shows the CO scheme for residential buildings with a small number of floors.

WITH contains supply 1 and return 2 heat pipelines of network water, communicated with an individual heat point 3 and connected, in turn, with the supply heat pipeline 4 WITH. A vertical supply riser 5 is connected to the supply heat pipe 4, connected to a floor horizontal branch 6. Heaters 7 are connected to the branch 6. In the same apartments where the vertical supply riser 5 is installed, a return riser 8 is installed, which is connected to the return heat pipe CO 9 and horizontal floor branches 6. Vertical risers 5 and 8 limit the length of floor branches 6 to one apartment. On each floor line 6, an apartment heating point 10 is installed, which serves to ensure the supply of the required coolant flow and to account for the heat consumption for heating each apartment and to control the air temperature inside the room depending on the outside temperature, heat input from solar radiation, heat generation in each apartment , wind speed and direction. To turn off each horizontal branch, valves 11 and 12 are provided. Air taps 13 serve to remove air from heaters and branches 6. Taps 14 can be installed at heaters 7 to control the flow of water passing through heaters 7.

Rice. 1. Scheme of the heating system for buildings with a small number of floors: 1 - heating supply network water; 2 - return heat pipe of network water; 3 - individual thermal

paragraph; 4 - supply heat pipe of the heating system; 5 - vertical supply riser; 6 - floor horizontal branch; 7 - heating devices; 8 - reverse riser; 9 - return heat pipe of the heating system;

10 - apartment heating point; 11, 12 - valves; 13 - air valves; 14 - taps for regulating the flow of water.

In the case of a multi-storey building (Fig. 2), the supply vertical riser 5 is made in the form of a group of risers - 5, 15 and 16, and the vertical return riser 8 is made in the form of a group of risers 8, 17 and 18. In this CO, the supply riser 5 and the reverse riser 8, connected respectively with the heat pipes 4 and 9, unite in block "A" horizontal floor branches 6 of several (in this particular case, three branches) of the upper floors of the building. The supply riser 15 and the return riser 17 are also connected to the heat pipes 4 and 9 and unite the horizontal floor branches of the next three floors into block "B". Vertical supply riser 16 and return riser 18 unite floor branches 6 of the three lower floors into block "C" (the number of branches in blocks A, B and C can be more or less than three). On each horizontal floor branch 6, located in one apartment, an apartment heating point 10 is installed. It includes, depending on the parameters of the coolant and local conditions, shut-off and control and instrumentation valves, a pressure (flow) regulator and a device for accounting for heat consumption (heat meter). To turn off the horizontal branches, valves 11 and 12 are provided. Valves 14 are used to regulate the heat transfer of the heater (if necessary). Air is removed through taps 13.

The number of horizontal branches in each block is determined by calculation and can be more or less than three. It should be noted that the vertical supply risers 5, 15, 16 and return risers 8, 17, 18 are laid in the same apartment, i.e. the same as in fig. 1, and this ensures high hydraulic and thermal stability of the CO of a multi-storey building and, consequently, the efficient operation of the CO.

By changing the number of blocks into which CO is divided along the height, it is possible to almost completely eliminate the influence of natural pressure on the hydraulic and thermal stability of the water heating system of a multi-storey building.

In other words, we can say that with the number of blocks equal to the number of floors in the building, we will get a water heating system in which the natural pressure arising from the cooling of water in heaters connected to floor branches will not affect the hydraulic and thermal stability of CO.

The considered SS provides high sanitary and hygienic indicators in heated rooms, saves heat for heating, and effectively regulates the air temperature in the room. It is possible to carry out the start-up of CO in action at the request of the resident (if there is a coolant) in the heat point 3 at any time, without waiting for the start-up of CO in other apartments or in the whole house. Taking into account that the thermal power and the length of the horizontal branches are approximately the same, the maximum unification of the CO units is achieved during the manufacture of the pipe billet, and this reduces the cost of manufacturing and installation of the CO. The developed system of apartment heating for multi-storey residential buildings is universal, i.e. such CO can be used for heat supply:

□ from the central source of heat (from heating networks);

□ from an autonomous source of heat (including a rooftop boiler).

Rice. 2. Scheme of the heating system of multi-storey buildings. 1 - supply heat pipe network water; 2 - return heat pipe of network water; 3 - individual heating point; 4 - supply heat pipe of the heating system; 5, 15, 16 - vertical supply risers; 6 - floor horizontal branch; 7 - heating devices; 8, 17, 18 - return risers; 9 - return heat pipe of the heating system; 10 - apartment heating point; 11, 12 - valves; 13 - air valves; 14 - taps for regulating the flow of water.

Such a system has hydraulic and thermal stability, can be single-pipe and two-pipe, and it can use any type of heating device that meets the requirements. The scheme for supplying the coolant to the heater may be different, when installing a tap at the heater, you can adjust the thermal output of the heater. Such CO can be used not only for heating residential buildings, but also public and industrial buildings. In this case, a horizontal branch is laid near the floor (or in the recess of the floor) along the plinth. Such a CO can be repaired and reconstructed if there is a need to redevelop the building. The system described above requires less metal consumption. Installation of such CO can be carried out from steel, copper, brass and polymer pipes approved for use in construction. The heat transfer of heat pipes should be taken into account when calculating heating devices. The use of apartment COs provides a reduction in heat consumption by 10-20%.

The idea to use apartment systems for heating multi-storey residential buildings was born a long time ago. However, such heating systems were not used even in newly built residential buildings for many reasons, including the lack of a regulatory framework and design recommendations. Over the past 5 years, a regulatory framework has been created and recommendations for the design of such systems have been developed. In Russia, there is still no experience in the operation of apartment COs connected to various heat sources.

When designing such systems, many questions arise regarding the placement of horizontal branches and places for laying vertical supply and return drains. The consumption of pipelines for the installation of horizontal branches will be minimal if the apartment in the plan is in the shape of a square or approaches a square.

It should be noted that the supply and return vertical risers can be laid in special shafts located in stairwells or common corridors. In the shafts on each floor, installation cabinets should be located in which the apartment input nodes are placed.

For mass housing construction, it is expedient to perform per-apartment COs as single-pipe horizontal ones with trailing sections and serial connection of heating devices. In this case, the consumption of pipes is significantly reduced, but at the same time, the heating surface of the heating devices increases (due to the reduction in thermal pressure) by an average of 10-30%.

Horizontal branches should be laid near the outer walls, above the floor, or in the floor structure or in special plinths - boxes, depending on the height of the heater, its type and the distance from the floor to the window sill (the distance from the floor to the window sill during new construction, if necessary, can be increased by 100-250 mm).

With long heaters, such as convectors, it will be possible to use through convectors and use a versatile (diagonal) connection of appliances to a horizontal branch, and this in many cases improves the heating of appliances and, consequently, increases their heat transfer. With open laying of horizontal branches, their heat transfer to the room increases, and this ultimately leads to a decrease in the surface of heating devices and, consequently, metal consumption for their manufacture decreases.

Such a system is convenient for installation and, as a rule, pipelines of the same diameter are used for horizontal branches. In addition, with single-pipe CO, higher coolant parameters (up to 105 ° C) can be used. When using three-way valves (or other constructive solution), it is possible to increase the amount of water flowing into the device, and this reduces the heating surface of the devices. With such a constructive implementation of the system, it is possible to repair it, i. replacement of pipelines, shut-off and control valves and heating devices in each apartment without opening the floor structure, etc.

The indisputable advantage of such heating systems is that only Russian-made materials and products can be used for their construction.

Literature

1. Scanavi A.N., Makhov L.M. Heating. Textbook for universities - M.: DIA Publishing House, 2002. 576 p.

2. SNiP. 41-01-2003. Heating, ventilation and air conditioning / Gosstroy of Russia. - M.: FSUE TsPP, 2004.

3. Livchak I.F. Apartment heating. - M.: Stroyizdat, 1982.

When designing large-scale heating systems (in particular, calculations for adjusting the heating system of an apartment building and its full functioning), special attention is paid to external and internal factors in the operation of the equipment. Several heating schemes for central heating have been developed and successfully applied in practice, differing from each other in structure, parameters of the working fluid and piping schemes in apartment buildings.

What are the types of heating systems in an apartment building

Depending on the installation of the heat generator or the location of the boiler room:

Heating schemes depending on the parameters of the working fluid:

Based on the piping diagram:

Functioning of the heating system of an apartment building

Autonomous heating systems of a multi-storey residential building perform one function - the timely transportation of the heated coolant and its adjustment for each consumer. To ensure the possibility of general control of the circuit in the house, a single distribution unit is mounted with elements for adjusting the parameters of the coolant, combined with a heat generator.

The autonomous heating system of a multi-storey building necessarily includes the following components and components:

1. The route of the pipeline through which the working fluid is delivered to apartments and premises. As already mentioned, the piping scheme in multi-storey buildings can be single- or double-circuit;
2. KPiA - control devices and equipment that reflects the parameters of the coolant, regulates its characteristics and takes into account all its changing properties (flow rate, pressure, inflow rate, chemical composition);
3. A distribution unit that distributes heated coolant through pipe lines.

A practical scheme for heating a residential multi-storey building includes a set of documentation: a project, drawings, calculations. All documentation for heating in an apartment building is compiled by responsible executive services (design bureaus) in strict accordance with GOST and SNiP. The responsibility for ensuring that the centralized central heating system will be operated correctly lies with the management company, as well as its repair or complete replacement of the heating system in a multi-apartment building.

How does the heating system work in an apartment building

The normal operation of the heating of an apartment building depends on compliance with the basic parameters of the equipment and the coolant - pressure, temperature, wiring diagram. According to the accepted standards, the main parameters must be observed within the following limits:

1. For an apartment building with a height of not more than 5 floors, the pressure in the pipes should not exceed 2-4.0 atm;
2. For an apartment building with a height of 9 floors, the pressure in the pipes should not exceed 5-7 atm;
3. The spread of temperature values ​​for all heating circuits operating in residential premises is +18 0 C / +22 0 C. The temperature in radiators on landings and in technical rooms is +15 0 C.

The choice of piping in a five-story or multi-story building depends on the number of floors, the total area of ​​\u200b\u200bthe building, and the heat output of the heating system, taking into account the quality or availability of thermal insulation of all surfaces. In this case, the difference in pressure between the first and ninth floors should not be more than 10%.

Single pipe wiring

The most economical variant of pipe wiring is according to a single-loop scheme. A single-pipe circuit works more efficiently in low-rise buildings and with a small heating area. As a water (and not steam) heating system, single-pipe wiring has been used since the beginning of the 50s of the last century, in the so-called "Khrushchev". The coolant in such a wiring flows through several risers to which apartments are connected, while the entrance for all risers is one, which makes the installation of the route simple and fast, but uneconomical due to heat losses at the end of the circuit.

Since the return line is physically absent, and its role is played by the working fluid supply pipe, this gives rise to a number of negative points in the operation of the system:

1. The room warms up unevenly, and the temperature in each individual room depends on the distance of the radiator to the point of intake of the working fluid. With such a dependence, the temperature on distant batteries will always be lower;
2. Manual or automatic temperature control on heaters is not possible, but bypasses can be installed in the Leningradka circuit, which allows you to connect or disconnect additional radiators;
3. It is difficult to balance a single-pipe heating scheme, since this is only possible when shut-off valves and thermal valves are included in the circuit, which, if the coolant parameters change, can cause the entire heating system of a three-story or higher house to fail.

In new buildings, a single-pipe scheme has not been implemented for a long time, since it is almost impossible to effectively control and account for the coolant flow for each apartment. The difficulty lies precisely in the fact that for each apartment in the "Khrushchev" there can be up to 5-6 risers, which means that you need to embed the same number of water meters or hot water meters.

A correctly drawn up estimate for heating a multi-storey building with a one-pipe system should include not only maintenance costs, but also the modernization of pipelines - the replacement of individual components with more efficient ones.

Two-pipe wiring

This heating scheme is more efficient, since in it the cooled working fluid is taken in through a separate pipe - the return pipe. The nominal diameter of the heat carrier return pipes is chosen the same as for the supply heating main.

The double-circuit heating system is designed so that the water that has given off heat to the premises of the apartment is fed back to the boiler through a separate pipe, which means it does not mix with the supply and does not take the temperature from the coolant delivered to the radiators. In the boiler, the cooled working fluid is heated up again and sent to the supply pipe of the system. When drawing up a project and during the operation of heating, the following number of features should be taken into account:

1. You can regulate the temperature and pressure in the heating main in any individual apartment, or in a common heating main. To adjust the parameters of the system, mixing units crash into the pipe;
2. When carrying out repair or maintenance work, the system does not need to be turned off - the necessary sections are cut off with shutoff valves, and the faulty circuit is repaired, while the remaining sections work and move heat around the house. This is the principle of operation, and the advantage of a two-pipe system over the rest.

The pressure parameters in the heating pipes in an apartment building depend on the number of floors, but lie in the range of 3-5 atm, which should ensure the delivery of heated water to all floors without exception. In high-rise buildings, intermediate pumping stations can be used to lift the coolant to the last floors. Radiators for any heating systems are selected according to design calculations, and must withstand the required pressure and maintain a given temperature regime.

Heating system

The layout of the heating pipes in a multi-storey building plays an important role in maintaining the specified parameters of the equipment and the working fluid. So, the upper wiring of the heating system is more often used in low-rise buildings, the lower one - in high-rise buildings. The method of delivery of the coolant - centralized or autonomous - can also affect the reliable operation of heating in the house.

In overwhelming cases, they make a connection to the central heating system. This allows you to reduce the current costs in the estimate for heating a multi-storey building. But in practice, the level of quality of such services remains extremely low. Therefore, if there is a choice, preference is given to autonomous heating of a multi-storey building.

Modern new buildings are connected to mini-boiler rooms or to centralized heating, and these schemes work so efficiently that it makes no sense to change the connection method to an autonomous one or another one (common house or apartment). But the autonomous scheme gives preference to apartment or house-wide heat distribution. When installing heating in each apartment, an autonomous (independent) piping is performed, a separate boiler is installed in the apartment, control and metering devices are also installed separately for each apartment.

When organizing a common house wiring, it is necessary to build or install a common boiler room with its own specific requirements:

1. Several boilers must be installed - gas or electric, so that in case of an accident it is possible to duplicate the operation of the system;
2. Only a double-circuit pipeline route is carried out, the plan of which is drawn up in the design process. Such a system is regulated for each apartment separately, since the settings can be individual;
3. A schedule of planned preventive and repair activities is required.

In a common building heating system, control and accounting of heat consumption is carried out on an apartment-by-apartment basis. In practice, this means that a meter is installed on each coolant supply pipe from the main riser.

Centralized heating for an apartment building

If you connect the pipes to the central heating system, then what will be the difference in the wiring diagram? The main working unit of the heat supply circuit is the elevator, which stabilizes the liquid parameters within the specified values. This is necessary because of the long length of heating mains in which heat is lost. The elevator unit normalizes the temperature and pressure: for this, the water pressure in the heat point increases to 20 atm, which automatically increases the coolant temperature to +120 0 C. But, since such characteristics of the liquid medium for pipes are unacceptable, the elevator normalizes them to acceptable values.

The heating point (elevator unit) functions both in a two-circuit heating scheme and in a single-pipe heating system of an apartment high-rise building. The functions that it will perform with this connection: Reduce the working pressure of the liquid using an elevator. The cone valve changes the flow of fluid into the distribution system.

Conclusion

When drawing up a project for heating, do not forget that the estimate for the installation and connection of centralized heating to an apartment building differs from the cost of organizing an autonomous system downwards.