Dry rotor or wet. How to choose the right circulation pump for heating systems. Benefits of a separate pumping unit

Circulation pumps are used in heating and hot water systems (hot water supply). The principle of operation is based on the forced circulation of fluid through the closed space of the pipeline.

These pumps are used in heating systems multi-storey buildings and country cottages. Due to the use of circulation pumps, the premises warm up faster and more evenly than when using the natural circulation of the coolant, where hot water is supplied through vertical pipe(riser) thanks to the natural convection method.

1 Description, device, principle of operation of the circulation pump

According to the device, the circulation pump, in fact, is similar to drainage installation. In stainless steel housing steel, cast iron or aluminum (sometimes bronze, brass) a rotor made of ceramic or steel is built in. The rotor shaft is equipped with a wheel with blades - an impeller. The paddle wheel is most often made from technopolymer.

The operation of such a device is due to the principle of centrifugal force, which is formed during the operation of the impeller. The movement of the coolant is carried out by capturing it from one side and forcing it into the pipeline from the other. A vacuum is formed in the suction pipe during the rotation of the impeller. The vacuum is responsible for the continuous process of circulation and supply of water to the suction pipe.

Water in such a mechanism can circulate at a speed of 2 m/s in domestic applications (to avoid vibrations and noises in pipes) and up to 8 m/s in industry. The pumps are powered by electricity, which is their advantage. After all, such a device, used in the industrial sector, consumes no more than 0.3 kW, in the household - up to 85W.

A heating system using circulation pumps is able to effectively heat rooms with any configuration of piping, with pipes of small diameter, including those built into the floor or walls.

The advantages of using this type of pumps include:

• rapid heating of the room;
• creation of a separate temperature regime in each room by means of a thermal relay;
• installation of the boiler in any place;
• the ability to adjust the rotor speed, which reduces energy costs;
• minimum number of air pockets.

1.1 Types of circulation pumps

Two types of circulation pumps are produced: “wet” and “dry” (with a wet and dry rotor).

The "wet" type is characterized by the fact that the rotor is located directly in the liquid that is pumped. The electric motor is located in a sealed part where water does not enter. The principle of operation of this mechanism is as follows: a rotating rotor accelerates the movement of water. The liquid in which the rotor is located is a coolant and lubricant for the mechanism.

Mechanisms with wet rotor are used in heating systems with a relatively small length of pipelines.

Advantages of the "wet" type of pumps:

• low noise level;
• ease of changing settings;
• stepless change of rotor speed;
• long period of service;
• no need for maintenance.

The main disadvantage of this type of device is the low level of efficiency (does not exceed 50%). The reason for the low productivity is that it will be almost impossible to seal the sleeve that separates the stator from the pumped liquid when the rotor diameter is increased.

In a "dry" type pump, the rotor does not come into contact with the coolant. Its working part is isolated from the engine using sealing rings, which are made of coal agglomerate, ceramic or stainless steel.

These pumps are more efficient. During operation, the sealing rings self-adjust and rub against each other. Their service life is at least 3 years. The efficiency is about 80%. But at the same time, running pumps with a dry rotor make a lot of noise, which is why they need to be installed in separate rooms with sound insulation. You also need to take into account the environment of the room in which such units are located. During operation, they create air turbulence, dust can rise up and penetrate into the system, which leads to damage to the surface of the seal rings.
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2 Popular manufacturers

Due to the great demand for these products, dozens, if not hundreds of enterprises around the world manufacture different types of circulation pumps. Therefore, I propose to review the products of some foreign manufacturers, as well as pumps Russian production.
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2.1 Salmson NXL

The French company Salmson is part of the WILO AG industrial group. Today, under the Salmson brand, a wide range of pumping products is produced, which has such characteristics as reliability, high quality, compliance with European standards.

Salmson circulation pumps are used in air conditioning, water supply, heating, ventilation systems. Them hallmark is that the rotor is practically not subject to contamination, since the water entering it passes through a cleaning filter.

In addition, the products of this series are characterized by the versatility of the model range, low noise, high quality and low cost. The pumps are equipped with a bronze casing, which makes it possible to use them for systems drinking water.
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2.2 Wester WCP 25-40G

Household surface circulation pump with nuts. Used for heating, air conditioning and floor heating systems. Can pump hot water, chemically non-aggressive liquids or liquids with a viscosity of not more than 2 sq. mm / s.

It has a "wet" rotor, manual three-stage switching of the number of revolutions.

The body is made of cast iron, the impeller is made of polymer.

Specifications:

• power - 93W;
• max head - 6m;
• throughput - 2.7 cubic meters / h;
• max temperature of the passed liquid — 110°C;
• max ambient temperature — 40°C;
• connection - 1 inch;
• max working pressure - 10 bar.

2.3 Vaillant 160928

The Vaillant circulation pump is used for the operation of ATMOmax and TURBOmax gas boilers, as well as in heating and hot water systems.

It supplies the coolant to the heating system or to the secondary heat exchanger. In the latter, cold water is heated.

Vaillant has the first and second degrees of speed with the possibility of manual switching. Manufacturers recommend keeping the pump in the second stage, since there will be more thermal power of the water supply and it takes less time to heat the water. The unit is switched to the first stage when it is necessary to reduce the noise level during its operation.
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2.4 Vortex BWZ 152½

This German-made equipment is suitable for heating systems and water supply systems. The Vortex circulation pump can pump hot water, chemically non-aggressive liquids or liquids with a viscosity of no more than 2 sq. mm / s, ethylene glycol with a concentration of no more than 40%.

Peculiarities:

• "wet" rotor;
• three-position speed control;
• included are union nuts;
• body - cast iron;
• impeller - polymer;
• motor housing - aluminum;
• silent process of work;
• small dimensions.

Index Z indicates the presence of a daily mechanical timer with a time step of 15 minutes.

Power - 0.025 kW, power supply - 230V, 50 Hz.
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2.5 Lowara TLCSOL

The circulation pump Lowara TLCSOL with a "wet" rotor is used in solar systems (systems with solar collectors).

The pumps are characterized by silent operation, as well as simple installation, which makes it possible to install them in any premises. The kit additionally includes 2 union nuts and a heat-insulating casing.

Characteristics of Lowara TLCSOL circulation pumps:

• country of origin - Italy;
• pumped liquid - water;
• voltage - 230V 50 Hz;
• max water temperature — 110°C;
• min water temperature — -10°C;
• body - cast iron;
• impeller - composite material;
• bearings are ceramic.

2.6 ATsML 1000

Russian-made single-stage centrifugal circulation pumps АЦМЛ 1000 are used in heating, water supply, fire extinguishing, irrigation and chemical production systems.

They are characterized by low noise level and high efficiency. There are different types of shaft seals. Transported liquid - pure water; liquids that are similar in characteristics to water; slightly aggressive and aggressive liquids.

Specifications:

• supply - up to 900 cubic meters / h;
• head - up to 90 m;
• max liquid temperature — 180°C;
• min liquid temperature — -15°C;
• max temperature environment— 40°C;
• housing and impeller - cast iron, bronze or stainless steel. Steel.

3 How to choose a circulation pump?

If you need a circulation pump, when choosing it, you should pay attention to the main characteristics: performance, pressure, coolant temperature, noise level, and also how much electricity it consumes.

The performance of the circulation pump is understood as the amount of liquid distilled. It is recommended that the pump pump a volume of water equal to three volumes of water per hour. heating system. It is recommended to choose a unit with a capacity of 10-20% in stock. Then it will not wear out for a long time and the premises will warm up sufficiently in the winter.

Also, the pump must provide sufficient pressure to overcome the resistance of the pipeline, raise the liquid to the desired height, and overcome all the bends of the heating system.

It is also necessary to clarify the temperature of the pumped liquid and correlate it with similar characteristics of the unit, as well as the type of coolant - water or antifreeze.

When considering energy consumption, it should be borne in mind that some of the most modern pumps consume less energy than a conventional light bulb. In addition, automatic control will help you save energy. heating appliances. In this case, the circulation pump will work intermittently. A special sensor will show when the temperature of the coolant has dropped below the set limit and will start the pump.

On how correctly you determine all the characteristics of the pump for your heating system, its service life will depend.
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main parameters

A modern circulation pump is a device similar in principle to working with drainage pump. At the same time, in most models, the body is made of the following materials:

• bronze;
• brass;
• cast iron;
• aluminum alloys.

The use of these substances reduces the effect of corrosion on the operation process. A rotating rotor is often made using ceramic materials. On the rotor shaft is a wheel with blades - an impeller.

The principle of operation of a circulation pump for heating or any other type is that during the start, due to the rotation of the impeller, an area with reduced pressure is formed near the inlet pipe. Such a vacuum draws in a certain portion of the coolant, and excess pressure is injected at the outlet pipe. This is facilitated by the centrifugal force that is formed during the rotation of the impeller. Thanks to this compression, fluid moves through a closed heating or hot water supply system.

For the effective operation of the hydraulic apparatus, the presence of such structural elements is necessary:

• housing with two inlet and outlet nozzles;
• impeller with blades;
• DC motor.

Device types

To figure out which circulation pump is better, you need to know their varieties. There are two large groups into which all devices of this type are divided. There are circulation pumps with a wet rotor or dry. In each case, they have their own positive and negative properties. Manufacturing companies are constantly working to improve the performance of models of all types.

Read this article: Where is a 12 volt circulation pump used

Wet rotor units

In devices of this type, the rotor is located in the liquid. Contacts are hidden in a special sleeve made of stainless steel.

During engine operation, additional grinding of the rings is carried out, which only increases the hermetic properties of the assembly.

Such an engineering solution uses a coolant in the form of a lubricant. The circulation pump with a wet rotor can be equipped with one of the types of electric motors:

• single-phase;
• three-phase.

The power of the electrical appliance is selected according to the design features of the apparatus. The inlet and outlet pipe is equipped with threaded connections or flanged ones, which make it easy to quickly mount the circuit for connecting the circulation pump.

The principle of operation of equipment with a wet rotor

The positive properties of this design are the following characteristics:

• small parameters and weight;
• low noise properties;
• minimum voltage consumption;
• long time of uninterrupted operation;
• ease of setup and a high degree of maintainability.

If the circulation pump in the heating system does not work, then this is easy to fix by replacing the damaged module.

The main disadvantage of a wet rotor apparatus is its low efficiency, which does not always reach 50%. This problem is more typical for large-sized devices with large-diameter rotors.

When mounting circulation pumps, the strict horizontality of the rotor shaft must be observed. This rule will ensure that the water lubricant is evenly distributed over the sleeve to the rolling bearings.

VIDEO: Installation of a Grundfos circulation pump with a wet rotor

Use of dry rotors

The rotor in pumps of this type was structurally separated by engineers with sealing rings made of ceramic or metal with high friction properties. During operation, the rings rotate relative to each other. A very thin water film remains in the narrow gap between the two surfaces of the rings. It helps to seal the assembly from the rest of the structure. Due to the pressure difference, the liquid does not flow to the rotor.

Constant grinding of the rings increases their wear, but a block of springs helps to reduce this factor, regularly pressing them against each other, minimizing gaps.

This type of device has more high efficiency which goes up to 80%. However, the design is not without certain disadvantages:

• Wet motor pumps are noisier than their counterparts and often require additional soundproofing.
• special requirements for the purity of the liquid used, since any contamination can violate the tightness of the pairing of the rings.

Scheme of the "dry" rotor

There are the following types of dry pumps:

• vertical, in which the electric motor is installed vertically, and the working pipes are installed in a single axis;
• horizontal, in which the motor is mounted in horizontal plane, the outlet pipe is installed radially, and the inlet - from the end side of the cochlea;
• block, in them the coolant is started along the axis, and exits in the radial direction.

VIDEO: Disassembly and repair of the pressure booster pump Oasis CNP 15/9

Features of the installation of circulation pumps

In most cases, the installation of this hydraulic equipment is carried out by specialists. However, this approach does not prevent you from installing the device yourself in a heating or hot water supply circuit. In this case, certain rules must be observed.

For installation, the least heated area with a coolant is selected - a return line that returns the cooled liquid to the boiler. For small rooms, area 200 square meters and less, this rule is rather a convention, since the temperature of the liquid at the inlet and outlet differs only by 2-3 0 C.

Be sure to observe the flow direction during installation in the diagram. It is indicated by an arrow on the pump housing. Shut-off valves are mounted on both sides of the pump, and a coarse filter is installed in front of the inlet pipe. The reliability of threaded connections is complemented by sealants. After the pump is installed in a horizontal position, the coolant is poured into the housing, and excess air is removed using a central screw.

With this article they read: Calculation of a circulation pump for a heating system of a private house

During the installation of the circulation pump in heating systems using combined circulation, a bypass (pipe with shutoff valves) must be installed. It will help, if repair or preventive maintenance of the pump is necessary, to let the coolant through the system due to the natural circulation of the liquid.

The cost of pumps often depends on their power characteristics. The approximate price is 65-215 $. The most popular models are products trademarks Wester, Grundfos, Pedrollo, Halm. Almost all of them have high performance characteristics. Domestic manufacturers do not produce household appliances, but focus on industrial products.

VIDEO: Installing a GRUNDFOS circulation pump in a heating system. Bypass installation

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The device and principle of operation of the circulation pump

Circulation pump device - implementation standard scheme centrifugal machine. The main structural components include:

• pump housing;
• a rotor that transmits rotation from the engine shaft to the turbine block;
• turbine impeller with inclined blades, which is also called the impeller;
• means of sealing, isolation from water or coolant;
• the main electrical circuit that switches operating modes and monitors engine parameters.

Circulation pumps can have a different body shape and the location of the outlet and inlet nozzles. This is done so that the device can be easily mounted, serviced in the operating conditions for which it is designed. In particular, the selection of the pump can be made according to the type of connection: with a flange, threaded connection, nut.

The circulating pump has small dimensions. It is often built directly into the internal cavity of the body of domestic gas heating boilers. Safety devices can be installed with the pump. The small size of the supercharger is easy to understand, given the purpose of the circulation pumps. They do not require a record liquid supply power. In fact, they move water literally in a horizontal direction.

The task of circulation pumps is to overcome hydraulic resistance pipelines. If an underfloor heating collector group is considered, the blower is busy creating a flow of very small volume as such, since there are no significant gravitational forces in heating scheme this type does not exist.

The principle of operation of the circulation pump can be illustrated in several ways.

1. The coolant enters the inlet pipe.
2. When the engine is turned on, the torque is transmitted through the rotor to the turbine wheel.
3. Rotating, the wheel moves water with inclined blades, which moves to the edge of the disk under the action of mechanics (distribution of forces along an inclined plane), as well as due to centrifugal force.
4. As you approach the edge of the disk, the speed of the water flow increases, as does its pressure.
5. The liquid is ejected into the outlet pipe.

As water or coolant moves to the edge of the turbine wheel, a rarefaction occurs in the inlet pipe, it captures a new portion of the working fluid for transportation.

Important! The circulation pump of a gas or solid fuel boiler is able to effectively serve a certain length of pipelines, pumping the volume of coolant declared in the characteristics. If you need more performance and pressure - it is not necessary to buy a separate, external supercharger. An additional pump can be installed in the system, which will create the necessary flow or help raise water to the second floor. They do the same when building a distributed, zoned floor heating system.

Both a conventional home heating system and a two-pump heating system can use different types of blowers. The main difference between the models offered on the market is in the engineering solution of the rotor-turbine zone.

Glandless pumps

Glandless circulation pumps - the most common type of blowers for the heating system of a private house or apartment. The devices are so named due to the fact that the operation of the nodes occurs directly in the coolant.

1. The rotor is placed in a special glass with sealing or vortex protection against leakage.
2. During operation, rotor parts, including plain bearings, are in water or coolant.
3. There is a continuous lubrication and cooling of parts of the structure.

Thanks to these features of work wet systems are stable, maintenance-free, low noise.

To prevent air from entering the rotor area, the pump is equipped with exhaust outlets. The top one is for work automated system, and gas is released through the front of the housing during commissioning or adjustment.

Important! The operation of the pump with a wet rotor, provided that air enters the pipelines, causes a sharp increase in wear of moving parts, overheating, jamming or irreparable damage to the equipment. The presence of abrasive particles in the coolant is not recommended. Therefore, a wet rotor water pump should only be installed in a closed heating system.

Dry rotor pumps

The dry rotor pump is available with careful isolation of the turbine block from leaks. The system has a number of advantages and disadvantages.

1. The advantage of dry systems is better cooling - most of the nodes in the heating system do not come into contact with the hot coolant.
2. Dry pumps are noisier.
3. The overall level of reliability of pumps with a dry rotor is lower due to the large number of seals, the lack of constant lubrication.

However, the main advantage of dry type blowers is that they are not afraid of airing.. They are also less disturbed by the abrasive suspension in the water - only the turbine suffers from it, in which the resource for failure is much higher than that of the rotor block with its plain bearings. Therefore, such superchargers should be chosen if an open heating system with a circulation pump is being built.

Variable speed pumps

The speed of the pump in the heating system plays a big role. By changing it, you can achieve:

• optimal mode of operation of heating equipment;
• stabilization of the temperature of all radiators, regardless of the distance of their location from the boiler;
• reducing the temperature of the coolant with a constant heating efficiency, since at a higher circulation rate, each passage of water loses less energy.

There are various technical solutions for pumps on the market today. Home heating can use a single-speed model, the performance of which must be selected in accordance with the characteristics of the boiler and the total volume of the heat carrier. Offered two, three, four speed models. Their work is based on changing the switching circuit of the motor pole pairs.

A more technologically advanced, but also noticeably expensive solution is frequency control. This type of pump does not provide step switching, but smooth speed control. This allows you to very finely tune the operation of the heating circuit.

The use of circulation pumps in home heating

Since some of the features of the operation of circulation pumps for water in various schemes heating, it is necessary to touch on the main features of their organization in more detail. It is worth noting that in any case, the supercharger is placed on the return pipe, if home heating involves raising the liquid to the second floor, another copy of the supercharger is installed there.

closed system

The most important feature of a closed heating system is sealing. Here:

• the coolant does not come into contact with the air in the room;
• inside the sealed piping system, the pressure is higher than atmospheric pressure;
• the expansion tank is built according to the hydraulic compensator scheme, with a membrane and an air area that creates back pressure and compensates for the expansion of the coolant when heated.

On a note! For a closed circuit, you can make an expansion tank with your own hands. Its capacity is calculated using simple formulas, it depends on the total volume of water in the system.

The advantages of a closed heating system are many. This is the ability to carry out desalination of the coolant for zero sediment and scale on the boiler heat exchanger, and filling in antifreeze to prevent freezing, and the ability to use a wide range of compounds and substances for heat transfer, from a water-alcohol solution to machine oil.

The scheme of a closed heating system with a single-pipe and two-pipe type pump is as follows:

When installing Mayevsky nuts on heating radiators, the circuit setting is improved, a separate air exhaust system and fuses in front of the circulation pump are not needed.

Important! A closed heating system built without tilting pipes, observing the level of the main lines of movement of the coolant, does not work without a circulation pump. It also does not function when the power is turned off.

Open heating system

External characteristics open system similar to a closed one: the same pipelines, heating radiators, expansion tank. But there are fundamental differences in the mechanics of work.

1. The main driving force of the coolant is gravitational. Heated water rises up the accelerating pipe; to increase circulation, it is recommended to make it as long as possible.
2. The supply and return pipes are placed at an angle.
3. Expansion tank - open type. In it, the coolant is in contact with air.
4. The pressure inside an open heating system is equal to atmospheric pressure.
5. The circulation pump installed on the feed return acts as a circulation amplifier. Its task is also to compensate for the shortcomings of the pipeline system: excessive hydraulic resistance due to excessive joints and turns, violation of tilt angles, and so on.

An open heating system requires maintenance, in particular, a constant topping up of coolant to compensate for evaporation from an open tank. Also, corrosion processes are constantly taking place in the network of pipelines and radiators, due to which the water is saturated with abrasive particles, and it is recommended to install

The scheme of an open heating system is as follows:

An open heating system with the correct angles of inclination and a sufficient height of the accelerating pipe can be operated and when power is off(stopping the circulation pump). To do this, a bypass is made in the pipeline structure. The heating scheme looks like this:

In the event of a power outage, it is enough to open the valve on the bypass bypass loop so that the system continues to work on the gravitational circulation scheme. This unit also makes the initial start-up of the heating easier.

Underfloor heating system

In the underfloor heating system, the correct calculation of the circulation pump and the choice of a reliable model are a guarantee of stable operation of the system. Without forced water injection, such a structure simply cannot work. Pump installation principle next:

• hot water from the boiler is supplied to the inlet pipe, which is mixed through the mixer block with the return flow of the underfloor heating;
• the supply manifold for underfloor heating is connected to the pump outlet.

The distribution and control unit of the underfloor heating is as follows:

The system works according to the following principle.

1. Installed at the pump inlet main thermostat, which controls the mixing unit. It can receive data from an external source, for example, remote sensors in the room.
2. Hot water of the set temperature enters the supply manifold and diverges through the floor heating network.
3. The incoming return has a lower temperature than the supply from the boiler.
4. The temperature regulator with the help of the mixer unit changes the proportions of the hot flow of the boiler and the cooled return.
5. Water of the set temperature is supplied through the pump to the inlet distribution manifold of the underfloor heating.

Important! In such a structure, there is no gravitational component of circulation. Therefore, when the power and pump are turned off, the warm floor simply does not work.

Main characteristics of circulation pumps

The main characteristics by which the choice of the circulation pump is made:

• pressure, showing the ability of the device to raise water to a certain height;
• performance and consumption, showing how much fluid the supercharger delivers per unit of time.

These parameters are key in the calculation of the heating system. The head will allow you to understand whether the supercharger is able to serve the pipeline network with a certain height difference. And the cost is calculated according to the requirements heating boiler for the planned volume of coolant.

Another factor that is often very important for the user is the mounting size of the device. This is the size of the pump and is a critical consideration if the blower is to be installed into an existing piping while still providing a neat and discreet installation.

All data required by the user is contained markings on the front. The numbers on the circulation pump mean:

• type of device (most often it is UP - circulating);
• type of speed control (not specified - single-speed, S - step switching, E - smooth frequency control);
• nozzle diameter (indicated in millimeters, means the internal dimension of the pipe);
• head in decimeters or meters (may vary from manufacturer to manufacturer);
• mounting dimension.

The marking of the pump contains information about the types of connections of the inlet and outlet pipes. The complete coding scheme and word order looks like this:

Responsible manufacturers always follow standard rules markings. However, individual companies may not indicate some of the data, for example, the installation dimension. You need to learn it directly from the documentation for the device.

The choice of a circulation pump is always made after a careful calculation, which takes into account the type of heating equipment, the volume of the coolant, elevation changes, and the minimum required blower performance.

Therefore, it is worth choosing a pump only from trusted brands. Reliable devices are also presented in the average price category. And if you need the highest quality and there is an opportunity to pay one and a half to two times more - you should pay attention to the products of the brands GRUNDOFS, WILO.

Overview of popular models

It is impossible to give a clear name of the model of the best among superchargers without a clear segmentation according to their operating conditions. Therefore, the rating of circulation pumps for heating represents the competition of brands and the key features of the equipment they offer.

1 Grundfos UPS

One of the most popular and high quality types of pumps. A company with roots in Denmark has ensured maximum reliability using stainless sleeves, ceramic bearings, turbine wheels made of composite materials. Glandless pumps are distinguished by the following features:

• low power consumption, from 45 to 220 W;
• very low noise level (up to 43 dB) and vibrations - to understand that the pump is working, you can only put your hand on it;
• wide temperature Range from 2 (-20 at individual models) up to 110 degrees Celsius;
• simple installation;
• unpretentiousness, lack of service;
• durability, the service life is at least 10 years.

Grundfos UPS pumps are very compact and lightweight. Their disadvantages include high price, up to 2 times higher than competitors. However, the popularity of products of this brand suggests that their characteristics justify the price tag.

2. Wilo Star RS

Products of this brand are considered the most reliable. Only proven and simple solutions are used in their design and electronic circuits. The pumps are characterized by:

• economy;
• simple power adjustment;
• reliability, durability - cast iron housing, polypropylene turbine wheel, metal graphite bearings, stainless shafts;
• operating temperature from -10 to 110 degrees Celsius;
• protection against surges and surges;
• ease of installation.

Wilo Star-RS pumps are compact, lightweight, maintenance-free. Their price is also higher than competitors, but lower than that of the leader of the rating. Users note that at the highest speed, the pump starts to make noise over time.

3. Gileks "Compass"

The Compass Series is a smart choice, a solid mid-ranger with attractive performance and value. Pumps are distinguished by:

• profitability;
• simple speed switching circuit;
• small dimensions;
• sufficiently low noise level up to 65 dB;
• rich equipment and easy installation;
• fault tolerance due to the lack of complex technical solutions and the use of reliable materials;
• low price.

The manufacturing company has an extensive service network, however, users note that the pumps of the Gileks "Compass" series break very rarely.

4. DAB VA

A series of pumps from an Italian manufacturer is optimal balance characteristics and prices. They are not able to offer record performance, but they are reliable and adapted to the realities of domestic power grids. Devices are characterized by:

• three-stage speed control;
• easy installation using quick coupling;
• two types of mounting dimensions of 130 and 180 mm;
• noise level up to 70 dB;
• affordable cost.

On a note! Today, the updated DAB VA line is presented on the market, where the issue of reliability has been carefully worked out. Cast aluminum engine shell, technopolymer turbine wheel, ceramic shaft and thrust bearing, graphite bushings, many stainless parts and a new generation of O-rings in EPDM.

Conclusion

Today on the market you can buy any circulation pump. In addition to those presented in the rating above, we offer adaptive systems, which independently determine the parameters of the working body and change the performance. For the user, the main thing is to correctly calculate the required performance of the supercharger. And then, if you do not buy frankly junk products from the Chinese garage industry, the heating system with a high-quality pump will function for a long time, without fail and stably.

Glandless circulation pumps

In the section "Pumps" we will talk about pumps for heating with a "wet" rotor. The circulation pump is a very important element in heating, air conditioning, hot water, and floor heating systems. Thanks to the pump, the coolant circulates in the "closed" heating system, the "warm floor" system, which increases heat transfer. When using a pump, smaller diameter pipelines can be installed, hence reducing the amount of coolant in the system, reducing the consumption of energy carriers and reducing the cost of the costs of the materials used, although it is necessary to additionally install. Such heating systems react faster to temperature fluctuations and are easier to adjust. The use of circulation pumps in heating systems allows saving up to 30% of energy carriers used to heat the coolant. Pumps for hot water supply (DHW) allow you to maintain a constant temperature of water in hot water systems (hot water recirculation). When choosing a circulation pump, it is necessary to consider where the pump will be used in the heating or hot water supply system. Structurally, the pumps have a clear division into pumps for heating and hot water. Pump housings for heating systems are made of cast iron, while hot water pump housings are made of bronze or brass. Circulating pumps for heating systems with wet rotor work constantly throughout heating season, therefore, high requirements are imposed on them: silent operation, low power consumption, simplicity and reliability. There are two most common types of circulation pumps - pumps with a "wet" and "dry" rotor. In this article, we will talk about wet rotor pumps.

Device and design

Structurally heating pumps with wet rotor consist of four main elements: stator, rotor, separating cup and housing (photo).

The design of pumps with a "wet" rotor

Mounting methods

Union nuts are manufactured and supplied for pumps with a "wet" rotor (photo)

or as the Americans call them, threaded connection with nominal bore 1″ and 1 1/4″. Pumps bigger size have flange connections. Circulation pumps for heating systems can be mounted directly on the pipeline in a horizontal or vertical position, provided that the axis of the pump shaft must always be horizontal. They can be mounted on both supply and return pipelines. It is preferable to carry out installation on the return pipeline. The arrow on the pump housing for heating systems indicates the direction of movement of the coolant. Before and after the circulation pump, it is necessary to install shut-off valves or gate valves of the same diameter as the nominal diameter of the pump. Valves or gate valves are used for the convenience of pump maintenance during maintenance or repair. In this case, the coolant does not need to be drained from the heating or hot water supply system. Between the shut-off valve and the suction pipe of the pump, it is imperative to mount a coarse filter of the same diameter as the nominal diameter of the pump. If several circulation pumps are used in the heating system, check valves must be installed on each of them. The valve is installed with the same diameter as the nominal diameter of the pump and is mounted after the pump on the discharge pipe up to the shut-off valve. In case the axis of the motor shaft is mounted vertically (fig.)

in relation to the horizon, during operation, in the upper part of the separation sleeve, airlock. A ceramic or graphite bearing will not be lubricated by the pumped liquid, which can lead to its overheating and, as a result, jamming of the rotor shaft. As we have already said, the bearings of wet rotor pumps are lubricated by the pumped liquid. In addition, the cooling of the stator will deteriorate due to insufficient fluid circulation. To do this, the liquid must constantly circulate through the separating cup. More information about installation methods can be found in the installation and operation instructions for circulation pumps for heating systems.

The point at which the characteristics of the circulation pump and the system intersect is called the operating point of the system and the pump. This means that at this point there is a balance between the useful power of the pump and the power required to overcome the resistance of the heating system. The pump head is always equal to the system resistance. The flow that the pump can provide also depends on the pressure. It must be remembered that the feed should not fall below a certain minimum. Otherwise, low performance may cause a strong increase in temperature in the pump chamber, which may damage the pump. To avoid this, the pump manufacturer's instructions must be followed. Working point outside operating characteristic pump may cause overheating and failure of the pump. When the flow changes during pump operation, the pressure also changes, and, consequently, the operating point is constantly shifting. It is up to the designer to find the calculated operating point in accordance with the requirements when operating the system in maximum mode. All other operating points are to the left of the calculated operating point. The figure shows the effect of changing the hydraulic resistance on the displacement of the operating point.

Moving the system operating point to the left of the calculated operating point increases the pump head. This will lead to increased noise in the heating system in the presence of control fittings and valves.

pump delivery

To determine the flow in the heating system, the following formula is used: Q \u003d Q N / 1.163 * Δυ (m 3 / hour)

Q- pump flow at the design point in [m 3 / h]

QN– thermal output of the boiler in [kW]

1,163 – specific thermal capacity of water [W*h/kg*K]

Δυ - the calculated temperature difference in the direct and return pipelines of the heating system, in kelvins [K], while 10 - 20 K can be taken as a basis for standard systems.

Pump head

To deliver the pumped coolant to any point in the heating system, the pump must overcome the sum of all hydraulic resistances. Since it is usually quite difficult to determine the laying pattern and the conditional passage of pipelines, the following formula can be used to approximate the pressure of the heating system:

H=R *L*ZF/10,000 (m)

R– friction losses in pipes [Pa/m]. In this case, the value of 50 Pa / m - 150 Pa / m can be taken as a basis for standard systems (depending on the year of construction of the house, in old houses due to the use of pipes larger diameter less pressure loss (50 Pa/m)).

L– length [m] of direct and return pipelines or: (house length + house width + house height) x 2

ZF- coefficient. for stop valves ≈1.3, thermostatic valve ≈1.7, mixer ≈1.2

In the presence of shut-off valves and thermostatic valves, you need to use the coefficient ZF=2.2.

In the presence of shut-off valves, thermostatic valves and a mixer, you need to use the coefficient ZF=2.6.

10000 – conversion factor (m) and (Pa)

Example: a boiler installed in an old apartment building has a capacity of 50 kW.

For a temperature difference Δυ=20 K (supply temperature=90 °C, return temperature=70 °C), the head is: Q=Q N /1.163*Δυ (m 3 /h)=50/1.163*20=2.15 m 3 / hour

When heating a similar building with a lower temperature difference (e.g. 10 K), the circulation pump must provide a double flow rate, i.e. 4.3 m 3 /h, provided that the heat produced by the heat generator can reach the consumers in the required amount.

The pressure loss due to friction in the pipeline is 50 Pa/m in our example,

the total length of the direct and return pipelines is 150 m, the coefficient is 2.2, since there is no mixer and thermostatic valves. As a result, we get the head (H): H \u003d R * L * ZF / 10000 (m) \u003d 50-150-2.2 / 10000 \u003d 1.65 m.

Operation maintenance and repair

Circulation pumps for heating systems are reliable and efficient equipment that works for a long time under the conditions of operation. But pumps with a "wet" rotor have one serious drawback. of these pumps does not exceed 50%, while for dry rotor pumps this figure can reach 80-90%. Therefore, such pumps are most in demand in individual heating and hot water systems.

Circulation pumps for heating systems with a “wet” rotor cannot be operated without a coolant flow - ceramic or graphite bearings may overheat and, as a result, the rotor may jam.

To reduce noise in closed heating/cooling systems with circulation pumps, it is necessary that there is no air in the system. Air is removed by automatic air valves or .

In practice, it often happens that the coolant contains fine suspension and scale. When the pump is running, the scale gradually settles and builds up on the working surfaces of the rotor and the glass. The distance between the rotor and the glass is 0.1-0.2 mm, due to the build-up of scale, the rotor "jams" in the glass. If a pump with a “jammed” rotor is energized for a long time, then this defect can lead to a more serious breakdown: overheating and short circuit of the windings. The stator fails, as the coolant flow decreases or completely stops, and the engine is not cooled enough. Unfortunately, motor rewinding workshops do not take into operation the stators of domestic circulation pumps, because of their high labor intensity and difficulty in rewinding, as a result, the purchase of a new pump. If the pump stator has not failed, then it takes quite a lot of time to wedging the rotor: from several hours to several days. This procedure is especially difficult with pumps that have a ceramic shaft. The shaft of such pumps is very fragile and can break if careless movement. As a rule, it was possible to wedge all the rotors that were repaired with such a defect.

To reduce scale in the heating system, you must:

• Flush the heating system before commissioning. Especially a lot of scale is formed in heating systems operating on the "natural" circulation of the coolant, since it was necessary to add water to the expansion tanks, and this water is not prepared. After installing a circulation pump in such a system and poor flushing of the heating system, all the scale that has accumulated over the years in pipes and radiators with slow natural circulation very quickly ends up in the pump due to the fact that the coolant speed has increased several times.
• Fill the heating system with special softened water.
• Do not drain the coolant from the system after the end of the heating season.
• After the end of the heating season, it is necessary to turn on the pump for 1-2 minutes at least once a month so that at the beginning of the heating season they do not encounter the problem of rotor jamming.
• Install in heating system

The second reason for the failure of pumps is the presence of suspension in the heating system. Suspension enters the ceramic bearings, and wear is formed on the bearings and the shaft (this happens especially quickly on bearings made of graphite). Due to the development, there is a backlash and additional noise, and at one fine moment the rotor “sticks” to the glass. Simply put, the rotor stops spinning. There are practically no spare parts for circulation pumps, and you have to buy a new pump. To prevent such defects, it is necessary to follow the same procedures as when the rotor is jammed.

Summing up, we can say modern systems heating, both in individual and urban buildings, need high-quality pumping equipment that can ensure efficient circulation of the coolant. For their long and reliable operation, it is necessary to comply with the installation conditions and operating rules. The pumps used must meet very stringent requirements: be economical, reliable and provide continuous work during the heating period for many years.

Thank you for your attention.

The circulation pump is a key figure in modern heating systems with forced circulation of the coolant. Its use eliminates the need to install the boiler at the lowest point of the room and makes it possible to use small diameter pipes with an arbitrary location of the line. In addition, the introduction of a circulation pump into the circuit increases the heating performance and reduces energy costs. The service life of the unit directly depends on the correct installation and compliance of the technical characteristics with the hydraulic parameters of the heating system. We will understand the intricacies of pump designs and the nuances that you need to pay attention to when choosing a device.

Circulation pumps for heating systems

The pump for heating systems consists of a cast-type housing, a ceramic or steel rotor with a plastic or light-alloy impeller (impeller), a stator installed in a casing, and a terminal box with an adjusting device.

When the electric motor rotates, the impeller throws the coolant to the outer edge of the volute made in the housing. Further movement and injection of the working fluid occurs due to centrifugal force. At the same time, a vacuum occurs at the inlet pipe of the pump, which contributes to the absorption of a new portion of the coolant.

The design of the circulation pump is typical for centrifugal units, but at the same time it has many interesting features. constructive solutions

Design of pumps for heating systems

Depending on the design, all pumping units of heating systems are divided into two types:

• dry circulation pumps;
• wet rotor pumps.

Both types of devices are quite effective in heating pipelines and have both advantages and disadvantages.

Dry type pumps

In devices with a dry rotor, the electric motor is placed outside the pump housing

In such units, the rotor does not come into contact with the working fluid, since all elements of the electric motor are separated from the working chamber of the device by a sealing system of a special type. It consists of polished, carefully fitted metal rings. To eliminate friction, a thin film of liquid is constantly present between the sealing elements, which acts as a lubricant. It is she who prevents damage to the seal rings.

Depending on the location of individual structural elements, dry pumps of heating systems can be divided into three types:

• console type pumps;
• vertical centrifugal pumps;
• block pumps.

The suction pipe of cantilever circulation pumps is located on the outer edge of the volute, while the discharge part is moved to the opposite side. A feature of the units of the second type is the location of the electric motor in vertical plane, which can significantly improve the performance of devices.

The device of the circulation pump with a dry rotor

Dry rotor pumps have numerous advantages:

• long service life;
• high performance;
• Efficiency is close to 80%;
• the ability to work with a coolant leak;
• high maintainability;
• relatively low cost;
• reliability;
• Possibility of mounting in any position.

At the same time, the increased noise level of units of this type does not allow them to be installed in residential premises. The disadvantages also include the requirements for the cleanliness of the coolant and the need for periodic maintenance and lubrication of the movable seal.

Glandless circulation pumps

The advantages of wet rotor circulation pumps have opened up wide prospects for their use in autonomous heating systems.

The rotor and impeller of this type of pumps are in the pumped coolant, which does an excellent job not only with its main function, but also with cooling the parts of the electric motor. The pump motor stator is separated from the rotor by a hermetic cup made of non-magnetic steel or carbon fiber. Wet type units are designed to operate in systems with a stable, rarely changing fluid flow. The presence of a control unit allows you to vary the number of connected windings, and accordingly, change the pump performance. The choice of the optimal operating mode has a positive effect on the efficiency of the unit.

The advantages of "wet" type units include:

• low noise level;
• no need for lubrication;
• efficient cooling method;
• ease of maintenance and installation;
• relatively low price of the unit and spare parts;
• long service life.

Pumps with a wet rotor are not without disadvantages in the form of low efficiency (a little more than 30%), the inability of the unit to work without a coolant, and the requirements for the horizontal orientation of the rotor shaft during operation.

Design features by connection method

Flange connection is most often used in high power pump models

In the pipelines of municipal and industrial highways, circulation pumps with a dry rotor are most often used, as more productive and powerful devices. Their connection is carried out mainly by a flange connection, and both a common support frame and a specially equipped foundation can be used for installation. At the same time, manufacturers also produce devices designed for embedding in autonomous heating systems. As a rule, they all have increased power and performance, and their installation does not require special fastening.

The delivery set of pumps with a coupling type of connection necessarily includes fasteners

Coupling connections of circulation pumps are typical for low-power wet-type units with direct-flow movement of the coolant, which can be built directly into the pipeline. Such devices are represented by a wide range of household centrifugal pumps, while powerful industrial units with a flanged connection require additional fastening of the pipeline using a console and foundation.

Criterias of choice

The efficient operation of the heating system is directly related to the performance of the circulation pump and the pressure at its outlet.

If the power of the unit is low, an insufficient amount of coolant will be pumped through the system, which will make it impossible to reach the required temperature.

In addition, when used in everyday life, important factors influencing the choice are the noise level (which depends on speed) and the efficiency of the unit's electric motor. Correct selection heating system pump requires thermal and hydraulic calculations, on the basis of which the optimal technical characteristics are determined.

Selection and installation of circulation pumps for heating systems (video)

Required performance

Before proceeding to determine the performance (flow rate, volumetric flow) of the circulation pump, calculate the amount of heat required to heat the room in the coldest time of the year. To calculate this parameter, there are special formulas that include both the physical parameters of the room and possible heat losses. We propose to use a simplified calculation method applicable for middle lane our country. It lies in the fact that required amount heat for heating 1 sq.m of the area of ​​the room is 100 watts. Therefore, to determine the required amount of thermal energy, the total area of ​​\u200b\u200bthe premises in the house or apartment should be multiplied by 100. For thermally insulated buildings, this parameter is reduced by 25 - 30%.

P is the required thermal power, kW;

Tf is the temperature on the supply side, ºС;

Tr is the temperature in the return line, ºС.

For example, for home with total area 80 sq.m at a temperature of the heat carrier at the outlet of the boiler 70 ºС and in the return pipeline 50 ºС, the flow rate will be at least Q=8×0.86/(70-50)=0.34m3/h.

Calculation of the required pressure

The next step in choosing a pump is to calculate the supply pressure of the coolant. This characteristic determines how easily the unit can overcome the hydraulic resistance of the liquid in the pipes of the heating system. The pressure value is calculated by the formula:

H=1.3×(S1×L1+S2×L2+Z1+Z2+…Zx)/10000, here:

S1, S2 – pressure losses in the pressure and return lines, Pa/m;

L1, L2 - respectively, the length of the supply and return branches, m;

Zx - individual resistances of pipeline sections, Pa.

Table of hydraulic resistance values ​​for various pipeline parameters

Values ​​for calculations can be taken from the technical data sheets for the equipment and structural elements heating systems or from special tables. For a simplified calculation, you can use the following values:

• resistance of straight sections of pipes - from 100 to 150 Pa / m;
• losses on fittings are up to 30% of the resistance in straight sections of pipelines;
• resistance on thermostatic valves adds up to 70% more of the calculated value.

Pressure losses at nodal points of heating systems

Having received the values ​​​​of volumetric flow and pressure, the required model of the circulation pump is selected from the catalog.

Engine power

An important characteristic of a centrifugal pump is power, since it is this parameter that affects how much electricity its electric motor will consume. Modern devices equipped with a step adjustment system, which helps to choose the most optimal mode of operation.

The consumption of household circulation pumps is minimized and comparable to a small electric lamp.

In addition, manufacturers are constantly working to improve the energy efficiency of the units. For these purposes, introduced single classification by this setting. For example, the consumption of class "A" appliances is no more than 6 W, which will require a little more than 90 kW / h of electricity per year. The power of the circulation pump, as well as the strength of the current consumed, is indicated in the technical data sheet for the product and is duplicated in the plate located on its body.

Noise level

The specifics of the use of modern circulation pumps in living conditions forces manufacturers to resort to non-standard solutions to reduce the level sound pressure. So, to reduce cavitation that occurs during the operation of the unit, blades and channels of an optimized shape are used, and pump casings are massive structural elements. In addition, the rotating parts are placed in a liquid, which also contributes to quiet operation. Most often, the noise level of the unit does not exceed 45 dB when operating at the highest speeds. If the regulator is set to the minimum level, then it is almost impossible to hear the sound of rotating elements.

Difficulty in installation and operation

For long and reliable operation centrifugal pump heating system, it is important to install it correctly. Previously produced models were recommended to be mounted on return heating branches due to the low temperature of the coolant, and, accordingly, better cooling device motor. Modern units are made of high-strength, heat-resistant materials, so such restrictions on this moment removed. At the same time, manufacturers require that the pump be installed only in positions in which the rotor shaft will occupy a horizontal orientation in space. An important factor affecting the service life of the product is the absence of air in the pipes of the heating system. Therefore, the installation of expansion tanks and Mayevsky taps is mandatory.

During installation, a bypass line is required for the operation of gravity heating systems in the event of a pump failure. At the same time, shut-off valves are mounted on both sides of the pump. Ball Valves, and a coarse filter and a check valve are installed on the side of the boiler. This scheme increases the service life of the unit and increases the reliability of its operation.

During operation, the pump does not require maintenance. The only thing that may be required when turning on the device is to turn the rotor to facilitate its start and remove air from the working chamber. To do this, there is a special plug on the body of the device, and a groove for a screwdriver is made on the rotor shaft.

Starting the pump and removing air from its working chamber (video)

Thanks to an agreement between manufacturers of centrifugal pumps, their marking has been unified and has the following features:

• the first digits after the brand of the unit indicate the connecting diameter of its nozzles;
• the next number characterizes the magnitude of the pressure.

For example, the designation WILO 25-60 indicates that the unit manufactured by WILO is designed to be connected to 25 mm or 1 ″ spurs, and its head is 6 m or 0.6 atm. Information about the pump model is contained on a plate placed on the device case. It also includes current consumption data for various operating modes.

Marking of circulation pumps

Manufacturers and prices

There are many manufacturers of circulation pumps on the market. The units of the German company Grundfos have excellent quality and technical characteristics. The cost of low-power devices from their lineup starts from 6600 rubles for the UPS 25-40 model and exceeds 19000 rubles for the UPS 32-80.

The products of another German brand WILO have an excellent price / quality ratio. So, for a product with parameters 25-20, you will have to pay from 5990 rubles, while the cost of a powerful pump with a head of 80 m is almost 11 thousand rubles. As you can see, compared to Grundfos, the difference is significant.

More budget decisions can be found in the line of models of the Italian company DAB and Pedrollo, the price of which is reduced by about 25% compared to their German counterparts. From inexpensive products, we can distinguish products under the brand name SPRUT made in China. The LRS 25-40 pump can be bought for only 1800 rubles, while for the most powerful LRS 32-120 you will have to pay no more than 9 thousand rubles. The only problem is the build quality and components of products from China.

The choice of a centrifugal pump determines how reliable and efficient the heating will work. Therefore, an accurate calculation of all parameters is needed, taking into account the specific features of piping. Proper installation of the unit affects the service life and performance, therefore, during installation, the recommendations of the equipment manufacturer must be strictly observed. Only in this case, the pump will be able to work for a long time, delivering comfortable heat to every corner of your home.

These products are widely used in industrial scale, as well as in everyday life. They are compact devices that perform the function of pumping liquids through pipelines. They are mainly installed in hot water, heating and cold water supply systems.

Due to the design and application features, even with a long route, to ensure the reliable operation of the circuit, it is sufficient to install a circulation pump of relatively low power.

They are used not only to ensure the movement of water. They are capable of pumping liquid media, the temperature of which lies in the range from -40 to +130 0C. Asynchronous motors are used as a power element. Circulation pumps are classified in different ways. Depending on the design, they are divided into 2 types: models with a "dry" and "wet" rotor. Such a difference in the engineering solution largely determines their functional purpose.

What are dry-rotor circulation pumps made of and what are they

The device of the circulation pump with a "dry" rotor provides increased power, which significantly increases its performance. Such models are capable of creating high pressure in systems and are used for long lines, or if it is necessary to provide liquid supply to a great height. That is why they found the main application for industrial purposes.

They consist of two main parts - an electric motor and a pump itself - which have union connection. They got their name because the rotor does not have direct contact with the liquid. In turn, they are all divided into subspecies.

• KM (console K) is an assembly mounted on a common platform. The axes of the pump and motor are located strictly on the same line. The widest application was found in urban water supply systems, at enterprises to meet production needs. They can work with both clean and contaminated liquids.

• Console-monoblock KML are considered low-pressure. The pump and motor are mounted in a common housing. They are easier to operate and maintain, therefore they are more used in public utilities, mounted in general house engineering communications. The device of the circulation pump for heating is simple and does not differ in any way from the design of the models used in other systems.

What these subspecies have in common is that the inlet and outlet pipes are located at an angle.

• In-line pumps are distinguished by the fact that they can be installed directly on the pipeline. Their nozzles are located on the same axis. They are more reliable in terms of design. The natural development of the connecting rings (between the pump and the motor) during operation is automatically compensated by the pressure spring. There is a "self-adjustment" of parts.

Design features of wet rotor pumps

Models with a "wet" rotor are distinguished by a low level of generated noise. They are of interest from the point of view of domestic use. Widely used in the arrangement of autonomous heating systems in private buildings or in small administrative, industrial premises. The pump rotor is directly in the liquid.

They are attractive because they are easy to repair at home. But in order to eliminate the malfunction, it is necessary to know the features of the design. Therefore, let us consider in more detail how the circulation pump with a “wet” rotor is arranged.

For the manufacture of the body of models for heating, as a rule, cast iron is used, although products are produced in which the body is made of stainless steel (non-ferrous metals, aluminum, bronze, brass). They are used for hot water and cold water systems. The rotor is placed in a special glass and is rigidly connected to the impeller (impeller).

This achieves its isolation from the stator. The peculiarity of the technology is that the shaft can be either metal or ceramic. It is fixed in plain bearings (graphite or ceramic). The volute, on which the inlet and outlet pipes are located, is attached to the body using bolts, which are unscrewed with a special key (hexagon) supplied with the product.

On the front (end) part of the pump there is a plug, unscrewing which, you can bleed excess air. Although it is also provided for its automatic removal during operation. For this, an air vent is located in the upper part. There is a box for electrical connection with mode control.

When the plug is completely turned out, access to the shaft opens, on the end part of which there is a slot for a screwdriver. Thus, it is possible to manually scroll if the pump does not start after a long "idle" (for example, due to salt deposits). Perhaps the only drawback of such pumps is their low efficiency. If for "dry" models it is within 70 - 80%, then for "wet" models it does not exceed 55%.

But at the same time, such a circulation pump scheme has a number of undeniable advantages:

• the liquid that it pumps at the same time cools and lubricates the parts;
• products at start-up automatically remove the air that has got inside;
• pumps are assembled according to modular principle. Therefore, when repairing, it is enough to replace the faulty part;
• due to low power, they consume little electricity;
• switching of operating modes is provided, which allows you to choose the most optimal;
• the ability to automatically control the process of starting and stopping when using a temperature sensor, which also reduces energy consumption;
• absolute noiselessness in work;
• does not require maintenance.

The latest models of "wet" pumps are available shaftless. The impeller (aka the rotor) rotates on ceramic bearings under the influence of electromagnetic field created by the stator winding. This greatly simplified the design (there are no shaft and seals) and increased reliability and durability. Even the ingress of small fractions along with the liquid will not affect the operation of the pump.

The uninterrupted and safe operation of the heating system of a country cottage is one of the first and most important issues that must be addressed when designing engineering systems. Therefore, it is very important to know how to choose a circulation pump for heating a private house, what parameters should be taken into account, how to get around the pitfalls during operation.

When is a circulation pump needed?

The circulation pump provides a given flow rate of the energy carrier in autonomous system heating (in the central system, this role is played by industrial units). The need for it arises already in the presence of one of the following factors:

wiring from 2 or more circuits;

the length of the route is more than 50 m;

at least with 1 level difference;

the presence of a complex circuit (heat-insulated floor system);

heating of 2 or more floors;

installation of a boiler in the basement;

in a heating system with free movement of the energy carrier with a temperature difference between the incoming flow and the return flow of more than 15-20 ºС;

at a temperature difference of more than 1-2 ºС in radiators of one system.

The circulation pump in a short time creates the desired speed of movement of the coolant in all circuits, ensuring uniform temperature distribution. The difference between the outlet and inlet temperatures, when correctly set, should be about 10 ºС, which saves fuel and ensures careful operation of the boiler. The efficiency of the system increases by an average of 20-50%, which becomes noticeable both in a stable room temperature and in saving money.

Principle of operation

Circulation pumps for heating private houses are a closed structure, consisting of electric motor and the working body - the flywheel or rotor.

Water enters the cavity (recess) of the pump, where it is given centrifugal motion by moving blades. Further, water enters the spiral channel and, by inertia, with an already acquired speed, a spiral flow that reduces hydraulic resistance, flows further. A vacuum is created in this place, where it is sucked new portion water.

Pump modifications and technical parameters

Based on the design features, the pumps are characterized by the productive power of the engine, the type of rotor and control.

Engine

An exact calculation of the engine parameters is performed for a specific heating system, but the general selection rule is simple - power is proportional to the performance (size) of the working part.

Rotor or flywheel

There are 2 principles of rotor operation:

Dry. Friction parts and the rotor itself are in a hermetically sealed housing - only the blades that create the flow come into contact with water. Such models are characterized high power, efficiency, but are more sensitive to mechanical contamination of the energy carrier. An annual technical maintenance of the electric motor is required. In addition, their installation should be carried out away from living rooms due to the increased noise level.

Dry rotor circulation pump - motor and blower are located in separate housings

Wet. The most common type due to unpretentiousness in maintenance, cost and variety of models. In an open design, moving parts (bearings, shafts, rotor, etc.) are in water, which is both a lubricant for them and a coolant for the engine. Corresponding stainless alloys are used, gaskets made of waterproof materials. The system is less whimsical to mechanical impurities in the energy carrier, and the service life of the household appliance is designed for 7 years.

In a wet rotor pump, the motor and blower are located in the same housing

Work management

Pump control is the choice of speed modes, on which the efficiency of the entire system depends. For heating, the minimum mode is used, while at low temperatures, rapid heat removal requires an increase in speed. To regulate this process, 2 types of control are used:

Mechanical. The choice of speed is made independently, and switching manually. Such control is effective for small circuits where the response to speed changes is fast. Pump for heating in a private house, most often purchased with such control due to its low cost and higher maintainability.

Smart upgraded models controlled by an automation system, which, depending on the temperature of the coolant, regulates the flow rate. They cost more, but when installing multi-component systems with collectors, they are indispensable. In addition, they increase energy efficiency by 25-35%.

Each manufacturer uses its own developments that contribute to trouble-free operation during the shelf life, so the prices for models with the same characteristics differ, as well as the quality of the equipment.

Cost reduction in cheaper firms occurs due to the minimum margin of safety. Most often, this implies a decrease in thickness on non-critical elements of parts, the use of less durable and cheap materials, which are enough only for the specified service life. The choice of the manufacturer largely determines quality characteristics products. You can navigate them by reading reviews or delving into the study of the materials used for parts.

On our website you can find contacts of construction companies that offer home insulation services. You can directly communicate with representatives by visiting the exhibition of houses "Low-Rise Country".

What do we consider when choosing

How to choose a circulation pump for a private house heating system, and what parameters you need to know for this. Since the pump is a power unit, the first selection criterion will be its power. Next, we determine the type of rotor, and lastly, the type of control.

To determine the power, you need to know the parameters of the heating system. For large objects: industrial, multi-storey - measurements are taken. In private homes, such accuracy is not needed, so it is enough to know:

Boiler performance. The calculation is made theoretically according to the formula: W thermal boiler * K bandwidth(1l/min=60l/hour). For 25 kW 25*60= 1500 l/h; for 40 kW 40*60= 2400 l/h.

pressure. Indicated in meters of water column. For this calculation, you need to measure the total length of the circuit and multiply by a factor of 0.6 (10 linear meters correspond to 0.6 m of the head). For contours one-story house standard equipment of 6 m w.st. is sufficient, while 2;- and more floors require the installation of a station or several pumps.

Rotor type. Affects the cost and subsequent maintenance. Increased efficiency allows it to be used in complex systems. But given the possibility of remote installation and regular maintenance.

Control. It also affects the cost of the unit itself, but the convenience and efficiency more than cover this drawback. In complex systems, it is recommended to use only this type of control.

Pressure and air relief valve. It is not installed in all models, but you can overpay for this function, as it prevents the pump from turning on “dry” and provides a trouble-free stop when the power is turned off (the water heats up to a critical temperature, the pressure increases and opens the outlet valve).

Manufacturers

Pumps of this category, regardless of the company, must be replaced after the end of the service life, since there is a high probability of stopping due to sudden breakdowns. The division of units is carried out by manufacturers, since each of them focuses on performance, cost and reliability, the final characteristics of the pump are different.

European - as a rule, all work in the middle or high price segment and offer high quality. The price reduction is due to optimal design solutions and marketing policy, including the transfer of production to China.

The German manufacturer stands out for its high quality and performance Grundfos- These models are equipped with energy-saving technologies. The declared service life is at least 10 years.

Company Wilo also produces high-quality industrial and household models, mainly with electronic control.

DAB– Italy. With regular maintenance, the pumps work flawlessly. The company spends a lot of money to eliminate noise in dry-type pumps.

Chinese - in addition to the price, you should pay attention to the company.

Well-established company models Oasis. First of all, this is the cost, which is 30% less than Russian and European counterparts. At the same time, work is guaranteed for the declared period of operation.

Russian - as well as other participants, work in accordance with European GOSTs and comply with all safety requirements.

Among Russian manufacturers, the most famous firm is "Subline Service" brand UniPump. Manufactures various types of pumps. Models are distinguished by their low cost and the use of the most rational technologies.

Wester owned by Impulse. Produces products in a limited range. The pumps are distinguished by good assembly and the use of parts with a high margin of safety.

Jilex company model " Master" and " Compass". The range includes pumps for small circuits and 2;-3 storey systems.

Where to install the pump

When installing pump for heating private houses, how to choose the place of installation is no less important issue than the characteristics of the equipment itself. Here it is necessary to take into account the principle of operation of the unit, the type of system and the number of its circuits.

One of the options for connecting the circulation pump to the heating system

The pump can be installed both at the inlet and at the outlet, providing convenient access to it for technical inspections and preventive maintenance. In most cases, it is preferable to install pumps at the inlet so that the pump pumps water at a lower temperature, but the main criterion is still ease of maintenance.

Video description

Clearly about the installation of pumps on the supply or return in the video:

Important! Installing a pump between radiators or in front of an expansion tank creates eddy currents that disrupt the direction of movement, forming temperature differences in various parts of the system. Therefore, it is very important that the pump is located between the boiler and:

radiator system;

collector;

expansion tank.

In a two-circuit system, with the connection of "warm floors", a separate pump is installed on each circuit.

Installation of the system, which includes a circulation pump, is carried out with the connection of a backup power supply with a reserve of 4-6 hours.

For 1;-2-loop systems, it is mandatory to install a bypass, since in the event of a power outage, it will ensure the natural movement of the energy carrier flow in the system.

For reference! Bypass is a bypass, a small section of pipe with shut-off or adjustable valves, sometimes with a check valve. It is built into the bypass of the circulation pump and, when it stops, ensures free flow of flow.

The operation of the pump can only be checked when the system is full. main revealing correct installation– uniform distribution of heat between all radiators.

Wet rotor pumps are installed in a vertical position.

A coarse filter is required, and a fine filter is desirable.

The pump must be located in a place accessible for maintenance.

After all calculations have been made, add 20% of the rated power, so you will ensure the gentle operation of the equipment in optimal mode 85-90%, excluding work at the limit of capacity.

Solid fuel boilers

This type requires separate consideration. When the electricity is turned off, the pump stops, but the heating of the energy carrier in the boiler continues: it is impossible to quickly extinguish burning wood or coal, after 3-5 minutes the temperature will reach critical levels and the pressure relief valve will work. If the pump is installed on the outlet pipe, the discharge occurs after 4-6 minutes, while its installation on the return pipe increases this time to half an hour.

Video description

Clearly about the installation of a pump in a system with solid fuel boiler in the next video:

Price factor

When choosing a circulation pump, the cost of the device itself and its efficiency during operation are important. As a rule, the operation of the pump is justified by saving on fuel consumption, and the cost of the model itself is determined by its performance. In Moscow, the range of prices for pumps is very large. Conventionally, they can be divided into 3 categories:

For 3.5-7 thousand rubles, you can buy basic functions, with a minimum period of work and most often one-time use;

Devices for 7.5-20 thousand are "workhorses" that accurately provide the declared characteristics, with a service life not less than that specified by the manufacturer and with several degrees of protection and an optimal margin of safety;

VIP systems with full automation, set additional features, a high margin of safety and the ability to provide heat for a large volume will already cost from 20 to 45 thousand rubles.

Video description

And some more thoughts about circulation pumps in the following video:

Benefits of a separate pumping unit

The use of pumping equipment is justified in terms of fuel economy and increasing the efficiency of the boiler, so many companies build pumping units into boilers. But a separate installation of the unit has its advantages: quick replacement without removing the boiler, the ability to control the process in case of emergency situations (for example, using a bypass). In addition, the pump can be installed in a system not provided for by the project at the initial stage.

Conclusion

Despite the apparent simplicity of the choice, the pump parameters must be technically justified, for which mathematical calculations are carried out taking into account the laws of heat engineering, the characteristics of the individual system, so the exact choice should be made by a specialist who takes into account all factors based not only on theoretical knowledge, but also on practical experience.