Heat accumulator for heating. Heating with a heat accumulator at night electricity tariff Heat accumulator for heating boilers

Heat accumulator - a unit for collecting and increasing heat in order to further application. The device is used in private houses, apartments, enterprises, as well as for engine preheating. The heat accumulator for the heating system allows you to reduce energy costs for space heating and hot water supply. The units are installed in the piping of a solid fuel boiler or connected to a solar system.

Purpose of the unit

The operation of a solid fuel boiler in the heating system is a certain cyclicity. First, fuel is placed in it, ignited, and then the boiler gradually reaches maximum power and transmits thermal energy through the coolant to the heating system.

The laying of firewood gradually burns out, heat transfer decreases, and the coolant cools down. During peak power part of the thermal energy remains unclaimed, and during the burnout of the fuel, on the contrary, it will not be enough. To repeat the cycle, it is necessary to carry out the laying of solid fuel again.

A pyrolysis boiler can partially solve this problem. long burning, but during its operation, the peaks of production and consumption of thermal energy often do not coincide. To resolve this situation, an energy storage device is installed for the heating system, which is known as a buffer tank or heat storage.

Piping of a solid fuel boiler with a heat accumulator

The operation of this unit is based on the high heat capacity of water. If during the period of maximum power of the boiler a certain amount of water is heated, then later its energy potential can be used for heating needs.

For example, water, when cooled by 1 ° C, can heat 1 m³ of air by 4 ° C. The simplest heat accumulator for heating boilers is a vertical container with four embedded in different sides nozzles. There are heat accumulators with a variety of storage materials:

On one side of the body, two pipes are connected to the boiler pipelines, and on the other - to the heating system. After starting the heater circulation pump starts pumping the coolant through the buffer tank.

Cold coolant enters the lower part of the storage tank, and hot coolant enters the upper part. Due to the significant difference in density, the water will not mix, and the hot coolant will gradually fill the entire container.

Usually, the volume of a thermal accumulator for heating is calculated in such a way that one bookmark of fuel is enough to completely fill the tank. hot water. That is, all the energy of the boiler, excluding losses, is converted into heat, which will be accumulated in the storage tank.

Thermal insulation allows you to keep the high temperature of the water for a long time. When the boiler stops working, the heating system continues to function. Thanks to the pump, hot water from the battery enters the pipelines and home heating appliances.

In place of the hot coolant, cooled water again enters the buffer tank through the lower branch pipe from the return line of the pipeline. Using electric boiler The heating circuit with a heat storage can be used at night when the discounted rate is in effect.

Schemes of boiler rooms with a heat accumulator

All storage tanks are vertical cylindrical tanks. They differ from each other only in the elements located inside the structure. There are several types of thermal accumulators:

All such designs can be produced in various variations depending on the complexity of the heating scheme, the number and types of heaters and water circuits used. Complex devices are easy to identify by the numerous nozzles coming out of the tank.

Heat accumulator or Buffer tank. And why is it needed. Storage tank or buffer capacity principle

Heat accumulator for heating boilers

We continue our series of articles with a topic that will be of interest to those who heat their homes solid fuel boilers. We will talk about the heat accumulator for heating boilers (TA) on solid fuels. This is a really necessary device that allows you to balance the operation of the circuit, smooth out the temperature drops of the coolant, while also saving money. We note right away that a heat accumulator for electric heating boilers is used only if the house has an electric meter with separate calculation of night and day energy. Otherwise, installing a heat accumulator for gas heating boilers does not make any sense.

How does a heating system with a heat accumulator work?

A heat accumulator for heating boilers is a part of the heating system designed to increase the time between loading solid fuel into the boiler. It is a reservoir in which there is no air access. It is insulated and has enough large volume. There is always water in the heat accumulator for heating, it also circulates throughout the circuit. Of course, as a coolant can be antifreeze liquid, but still, because of its high cost, it is not used in circuits with TA.

In addition, there is no point in filling the heating system with a heat accumulator with antifreeze, since such tanks are placed in residential premises. And the essence of their application is to ensure that the temperature in the circuit is always stable, and, accordingly, the water in the system is warm. The use of a large heat accumulator for heating in country houses temporary residence is impractical, and a small reservoir is of little use. This is due to the principle of operation of the heat accumulator for the heating system.

The TA is located between the boiler and the heating system. When the boiler heats up the coolant, it enters the TA;
then the water flows through the pipes to the radiators;
The return line returns to the TA, and then immediately to the boiler.

Although the heat accumulator for the heating system is a single vessel, due to its large sizes the direction of flow at the top and bottom is different.

In order for TA to perform its primary function of heat storage, these streams must be mixed. The difficulty lies in the fact that heat always rises, and the cold seeks to descend. It is necessary to create conditions so that part of the heat sinks to the bottom of the heat accumulator in the heating system and heats the return coolant. If the temperature has evened out in the entire tank, then it is considered fully charged.

After the boiler fired everything that was loaded into it, it stops working and TA comes into play. The circulation continues and it gradually releases its heat through the radiators into the room. All this happens until the next portion of fuel enters the boiler again.

If the heat storage for heating is small, then its reserve will last for a very short time, while the heating time of the batteries increases, since the volume of the coolant in the circuit has become larger. Cons of using for temporary residences:

the warm-up time increases;
a larger volume of the circuit, which makes filling it with antifreeze more expensive;
higher installation costs.

As you understand, filling the system and draining water every time you arrive at your dacha is at least troublesome. Considering that the tank alone will be 300 liters. For the sake of several days a week, it is pointless to take such measures.

Additional circuits are built into the tank - these are metal spiral pipes. The liquid in the spiral does not have direct contact with the coolant in the heat accumulator for heating the house. These can be contours:

low-temperature heating (warm floor).

Thus, even the most primitive single-circuit boiler or even a stove can become a universal heater. He will provide the whole house necessary heat and hot water at the same time. Accordingly, the performance of the heater will be fully utilized.

IN production models, manufactured in working conditions, additional heating sources are built in. These are also spirals, only they are called electric heating elements. There are often several of them and they can work from different sources:

circuit;
solar panels.

This heating is additional options and is not mandatory, consider this if you decide to make a heat accumulator for heating with your own hands.

Heat accumulator piping schemes

We dare to assume that if you are interested in this article, then most likely you decided to make a heat accumulator for heating and tie it yourself. You can come up with a lot of connection schemes, the main thing is that everything works. If you correctly understand the processes occurring in the circuit, then you can quite experiment. How you connect the HA to the boiler will affect the operation of the entire system. Let's first take a look at the most a simple circuit heating with a heat accumulator.

A simple TA strapping scheme

In the figure you see the direction of movement of the coolant. Please note that upward movement is prohibited. To prevent this from happening, the pump between the TA and the boiler must pump large quantity coolant than the one that stands up to the tank. Only in this case will a sufficient retracting force be formed, which will take part of the heat from the supply. The disadvantage of such a connection scheme is long time circuit heating. To reduce it, you need to create a boiler heating ring. You can see it in the following diagram.

TA piping scheme with a boiler heating circuit

The essence of the heating circuit is that the thermostat does not mix water from the TA until the boiler warms it up to the set level. When the boiler is warmed up, part of the supply goes to the TA, and the part is mixed with the coolant from the reservoir and enters the boiler. Thus, the heater always works with an already heated liquid, which increases its efficiency and the heating time of the circuit. That is, the batteries will get warm faster.

This method of installing a heat accumulator in a heating system allows you to use the circuit in offline when the pump is not running. Please note that the diagram shows only the nodes for connecting the TA to the boiler. The circulation of the coolant to the radiators occurs in a different way, which also passes through the TA. The presence of two bypasses allows you to play it safe twice:

the check valve is activated if the pump is stopped and the ball valve on the lower bypass is closed;
in the event of a pump stop and breakdown check valve circulation is carried out through the lower bypass.

In principle, some simplifications can be made in such a construction. Given the fact that the check valve has a high flow resistance, it can be excluded from the circuit.

TA piping scheme without check valve for gravity system

In this case, when the light disappears, you will need to manually open the ball valve. It should be said that with such a wiring, the TA should be above the level of the radiators. If you do not plan that the system will work by gravity, then the piping of the heating system with a heat accumulator can be performed according to the scheme shown below.

Scheme of piping TA for a circuit with forced circulation

In TA, the correct movement of water is created, which allows ball after ball, starting from the top, to warm it up. Perhaps the question arises, what to do if there is no light? We talked about this in an article about alternative power sources for the heating system. It will be more economical and more convenient. After all, gravity circuits are made of pipes large section, moreover, not always convenient slopes must be observed. If you calculate the price of pipes and fittings, weigh all the inconveniences of installation and compare it all with the price of a UPS, then the idea of \u200b\u200binstallation alternative source nutrition will become very attractive.

Calculation of the volume of the heat storage

The volume of the heat accumulator for heating

As we have already mentioned, it is not advisable to use a small volume TA, while too large tanks are also not always appropriate. So the question arose of how to calculate the required volume of TA. I really want to give a specific answer, but, unfortunately, it cannot be. Although there is still an approximate calculation of a heat accumulator for heating. Let's say you don't know what heat loss your house is and you can't find out, for example, if it hasn't been built yet. By the way, to reduce heat loss, you need to insulate the walls of a private house under the siding. You can choose a tank based on two values:

the area of the heated room;
boiler power.

Methods for calculating the volume of TA: room area x 4 or boiler power x 25.

It is these two characteristics that are decisive. Various sources offer their own method of calculation, but in fact these two methods are closely related. Suppose we decide to calculate the volume of a heat accumulator for heating, starting from the area of \u200b\u200bthe room. To do this, you need to multiply the quadrature of the heated room by four. For example, if we have little house 100 square meters, you will need a tank of 400 liters. This volume will reduce the loading of the boiler up to two times a day.

Undoubtedly, and so it is pyrolysis boilers, in which fuel is placed twice a day, only in this case the principle of operation is slightly different:

fuel ignites;
the air supply is reduced;
the smoldering process begins.

In this case, when the fuel flares up, the temperature in the circuit begins to rise rapidly, and then smoldering keeps the water warm. During this very smoldering, a lot of energy escapes into the pipe. In addition, if a solid fuel boiler works in tandem with a leaky heating system, then at peak temperature expansion tank sometimes boils. In the truest sense of the word, water begins to boil in it. If the pipes are made of polymers, then this is simply fatal for them.

In one of the articles about polymer pipes we talked about their characteristics. TA takes away some of the heat and the tank can boil only after the tank is fully charged. That is, the possibility of boiling, with the right amount of TA, tends to zero.

Now let's try to calculate the volume of TA, based on the number of kilowatts in the heater. By the way, this indicator is calculated on the basis of the quadrature of the room. 1 kW is taken for 10 m. It turns out that in a house of 100 square meters there should be a boiler of at least 10 kilowatts. Since the calculation is always done with a margin, we can assume that in our case there will be a 15 kilowatt unit.

If you do not take into account the amount of coolant in the radiators and pipes, then one kilowatt of the boiler can heat approximately 25 liters of water in the TA. Therefore, the calculation will be appropriate: you need to multiply the boiler power by 25. As a result, we will get 375 liters. If we compare with the previous calculation, the results are very close. Only this, taking into account that the boiler power will be calculated with a gap of at least 50%.

Remember, the more TA, the better. But in this case, as in any other, one must do without fanaticism. If you put a TA for two thousand liters, then the heater simply cannot cope with such a volume. Be objective.

utepleniedoma.com

Heat accumulator in the heating system

The heating system includes, in the usual view that has developed over the years, three elements - a heat source (boiler), pipelines and directly heating appliances(radiators). But if this is a private house with a solid fuel boiler (wood, peat briquette, coal) and you want to increase efficiency and save yourself from the need to constantly monitor the furnace, then it may be worth using such a unit as a heat accumulator in the system. [content]

The principle of operation of the heat accumulator

The main task performed by the heat accumulator is to increase the inertia of the heating system. To do this, increase the volume of the coolant and, consequently, the amount of heat accumulated by it. Thus, the battery is an insulated container embedded in the heating circuit.

As mentioned above, the battery significantly increases the inertia of the system, that is, although the coolant heats up longer, it accumulates more heat and gives it longer and reduces temperature fluctuations.

Internal organization heat accumulator

Thus, if the house is connected to central heating or the system uses gas or liquid fuel boilers operating in automatic mode, heat accumulators are simple extra costs material and funds. But there are cases when their use is more than justified:

If solid fuel boilers are used in the heating system (especially without bunker loading), and there is no way to ensure their constant maintenance (in a private house). In this case, the heat accumulator will provide a constant stable temperature in the room, and even be able to smooth out the inevitable surges during cleaning and ash removal;
If electrical water heating and a differentiated system of payment for electricity is applied. Heat accumulators will make it possible to accumulate heat during hours when the tariff is minimal, and in the future, heaters can be used at minimum power;
If the heating system has periods of peak analysis of thermal energy (most often this is due to the cost of heating water, for example, with intensive operation of showers), and installing an additional boiler is not practical. The battery will be able to provide heat transfer during these usually short periods of time.

Where the heat accumulator will be "superfluous"

Sometimes for heating systems, on the contrary, it is desirable to quickly set the temperature and decrease it, in this case, the increased amount of coolant that the accumulation tanks accumulate will only interfere with rapid heating and cooling and fine adjustment temperature. In particular:

If heating is needed only for short periods of time and excessive fuel consumption is undesirable. For example, a boiler house is used to heat a dryer, which is used only occasionally. In this case, it does not make sense to heat the empty room from which the material is unloaded with the accumulated heat.
If, in addition to heating, the heating plant is also used to provide heat for some technological equipment and a quick and accurate change of temperature regimes is required - increased inertia will only interfere.

How heat accumulators crash correctly

If a forced circulation heating system is used, then the tie-in point does not play special significance, since the pump delivers thermal energy from the accumulator. You can choose any comfortable spot given that the battery has a decent size.

For its correct operation, it is necessary to correctly position the connecting pipes - the inlet (according to the movement of the thermal energy carrier in the system) at the bottom, the outlet at the top.

Heat accumulator connection diagram

If heating with natural circulation is used, then the location of the tie-in plays an important role. Many people make the mistake of combining heat accumulators and expansion tanks. The expansion tank is located at the highest point of heating and hot water from it can begin to move, only cooling down through the pipes and increasing its density. For effective work The thermal energy accumulator must be located at the bottom of the heating supply pipe and as close as possible to the boiler.

Is it possible to assemble and install a thermal energy accumulator on my own?

From a constructive point of view, thermal energy accumulators are quite simple - this is a container with heat-insulated walls, equipped with nozzles for connecting to the heating system. Therefore, it will not be difficult for any person who has the skills of plumbing and welding work.

The question of calculating the thermal insulation of the walls may only arise. But in this case, the principle “more is better than less” can be applied, since for tanks used as heat accumulators, due to their shape, there is no concept of effective thermal insulation radius.

The video below shows the installation diagram and the principle of operation of the heat accumulator:

all-for-teplo.ru

A heat accumulator for a heating system - the main advantages. Click!

The desire of many owners of private houses and cottages to use resources as efficiently as possible to heat their homes quite often faces the same problem - even when using all modern technologies insulation and energy saving, installation of the most economical heating boilers - there is no significant saving of resources.

In many ways, this is a consequence of mistakes made long before the question of prudent use of resources and the use of modern construction technologies was raised. But what about the new houses built according to all modern canons, has the limit of development really come?

For most it will stay that way. rhetorical question, but for those who decide to really use scientific knowledge, and not excerpts from advertising booklets, it is worth thinking about including a new element in the heating system - a heat accumulator.

How the heating system works

In the modern understanding of the energy efficiency of heating installations, including separate house or cottage, Lately the emphasis has shifted significantly from the fuel consumption indicator for space heating to the indicator that characterizes the efficiency of energy use for the complete heat supply of the house.

Such a justified focus on energy efficiency allows us to take a fresh look at the problem of home heat supply, which includes two main tasks:

House heating;
hot water supply.

A new way to save energy in the heating system of a building today is the installation of additional equipment in the heating system, the function of which is to accumulate thermal energy and gradually consume it.

The use of a heat accumulator in the scheme of heating system devices, where the solid fuel boiler acts as the main source of energy, makes it possible to reduce fuel consumption by up to 50% without additional costs. heating season. But this is in the future, but for now it is quite clear to consider the principle of operation of this device.

The principle of operation of the system with a solid fuel boiler

The highest effect from connecting to the system will be in relation to solid fuel boilers.

The heat released during the combustion of fuel through the heat exchanger through the pipeline enters the registers or radiators, which are essentially the same heat exchangers, only they do not receive heat, but, on the contrary, give it to surrounding objects, air, in general, to the heating room.

Cooling down, the coolant - water in the batteries, goes down and again flows into the boiler heat exchanger circuit, where it heats up again. In such a scheme, there are at least two points associated with a large, if not a huge loss of heat:

direct direction of movement of the coolant from the boiler to the registers and rapid cooling of the coolant;
a small volume of coolant inside the heating system, which does not allow maintaining a stable temperature;
necessity constant maintenance stable high temperature of the coolant in the boiler circuit.

It is important to understand that such an approach can only be called wasteful. After all, when laying fuel, first at a high combustion temperature in the premises, the air warms up quite quickly. But, as soon as the combustion process stops, the heating of the room will also end, and as a result, the temperature of the coolant will drop again, and the air in the room will cool.

Using a thermal storage

Unlike standard system heating, a system equipped with a heat accumulator works a little differently. In its most primitive form, immediately after the boiler, the tank is installed as a buffer device.

A tank with multilayer thermal insulation is installed between the boiler and pipelines. The capacity of the tank, and it is calculated in such a way that the amount of coolant inside the tank is greater than in the heating system, contains the coolant heated from the boiler.

Several heat exchangers are introduced inside the tank for the heating system and for the hot water supply system. The internal volume of the accumulator heated from the boiler can maintain a high temperature for a long time and gradually release it for heating and water supply systems.

Given that the smallest tank has a volume of 350 liters of water, it is easy to calculate that by spending the same amount of fuel when using a heat accumulator, the effect will be much greater than with a direct heating system.

But this is the most primitive kind thermal device. A standard, designed to really work in the conditions of heat supply of a separate house, a heat accumulator can have:

The price of such batteries depends on many factors:

tank material;
the volume of the internal tank;
the material from which the heat exchanger is made;
manufacturer's firms;
a set of additional equipment;

Specialist note: calculate correct work of the entire heating system, starting from the TT boiler and ending with the diameter of the steamers, in principle, you can do it yourself, but it should be borne in mind that the power of both the boiler and the installation itself must be designed to work in conditions of maximum low temperatures in the region.

More detailed information on this issue today can be found on the pages of Internet sites, both in text form and using the services of specialized online calculators, and of course in specialized companies involved in the development and installation of heat supply systems.

Everything is electronically controlled

Perhaps for many such a thing as " smart House has long been part of the normal rhythm of life.

A house in which electronics takes over many functions for the maintenance and management of systems cannot do without the participation of electronic components and the operation of the heating and water supply system with a heat accumulator.

To maintain a stable comfortable temperature, it is necessary not so much to constantly burn fuel in the boiler furnace, but to maintain a stable temperature in the heating system. And with such a task, the electronic control of the operation of the heat accumulator is quite coping.

Control board features:

In addition, the electronic component can be perfectly used as a controller of the operation of both solid fuel boilers and electric heaters, and even as a solar collector system for maximum benefit and resource saving.

The economic effect of even including a heat accumulator in the heat supply scheme allows, as already mentioned, to reduce fuel costs in the heating season by up to 50%, and given that the price of energy carriers is constantly growing, such an investment becomes not only profitable, but already mandatory for new buildings.

Watch the video in which the user explains in great detail the scheme of the solid fuel boiler, coupled with a heat accumulator:

heat.guru

Heat accumulator in the heating system: familiarity with the principle of operation, design and installation options

Why are heat accumulators needed in heating systems? How are they arranged? How to include a heat accumulator in a common circuit when installing a heating system with your own hands? Let's try to figure it out.

The hero of our article is in the photo on the right.

First meeting

What is a storage tank for heating?

In the very simple execution- high cylindrical or square section container with multiple nozzles different height from the base. Volume - from 200 to 3000 liters (the most popular models are from 0.3 to 2 cubic meters).

The list of options and options is quite large:

The number of nozzles can vary from four to a couple of dozen. It all depends on the configuration heating system and on the number of independent circuits.
The thermal accumulator of water heating can be thermally insulated. 5-10 centimeters of foamed polyurethane foam will significantly reduce untargeted heat losses if the tank is located outside the heated room.

Tip: even if the tank is inside the house and, it would seem, its heat transfer helps the radiators to perform their functions, thermal insulation will not hurt. The amount of heat emitted by a tank with a volume of 0.3-2 cubic meters is VERY large. Our plans do not include organizing a round-the-clock sauna.

The wall material can be either black steel or stainless steel. It is clear that in the second case, the service life of the heat accumulator is longer, but its price is also higher. By the way, in closed system water quickly becomes chemically inert, and the corrosion process of black steel is greatly slowed down.
The tank can be divided into communicating sections by several horizontal partitions. In this case, the stratification of water by temperature inside its volume will be more pronounced.
Flanges for mounting tubular electric heaters can be located on the tank. In fact, with sufficient power, the accumulator for heating systems will turn into a full-fledged electric boiler.
The heat storage tank can be equipped with a heat exchanger for the preparation of hot drinking water. Moreover, it can be flowing plate heat exchanger, and storage tank inside the main tank. Compared to the amount accumulated by the tank heat costs for heating water in any case will be negligible.
An additional heat exchanger for connecting the solar collector can be located at the bottom of the tank. It is at the bottom - to ensure efficient heat transfer from the collector to the storage tank, even at low efficiency (for example, at dusk).

So the heat accumulator is used in the solar heating system.

Functions

It is easy to guess that heating heat accumulators are needed in order to accumulate thermal energy in reserve. But even without them, the heating seems to work, and not bad. In what cases is their use justified?

solid fuel boiler

For solid fuel boilers (with or without a water circuit), the most efficient mode of operation is in which the fuel burns with a minimum amount of residues (including not only ash, but also acids and tar) and maximum efficiency - full power. Power adjustment is usually carried out by restricting air access to the furnace - with unambiguous consequences.

However, dispose of all thermal power- means in a short time to heat the radiators almost red-hot, and then let them cool down. This mode is extremely inefficient, leads to accelerated wear of pipes, their connections and provides uncomfortable temperature regime in the house.

This is where a heating system with a heat accumulator comes to the rescue:

The heat generated by the boiler at full power is utilized to heat the water in the tank.
After the fuel burns out, the water continues to circulate between the storage tank and the radiators, taking away heat from it GRADUALLY.

As a bonus, we get a much rarer kindling of the boiler, which will save us both strength and time.

The buffer capacity will allow solid fuel boiler work optimally.

Electric boiler

What is the advantage of thermal storage heating when electricity is used as a heat source? After all, all modern electric boilers can smoothly or stepwise regulate power and do not need frequent maintenance?

Key phrase - night rate. The cost of a kilowatt-hour in the presence of a two-tariff meter can be VERY different at night, when the power systems are unloaded, and during the day, at the peak of consumption.

By varying tariffs, power engineers distribute electricity consumption more evenly; well, this is in our favor:

At night, the programmable boiler turns on by a timer and heats the accumulator for heating to its maximum operating temperature at 90 degrees.
During the day, the accumulated thermal energy is used to heat the home. The flow rate of the heat carrier for heating systems is dosed by adjusting the performance of the circulation pump.

A heat accumulator in combination with a two-tariff meter will help to significantly save on heating.

Multi-circuit heating

Another very useful function of the storage tank is the ability to use it simultaneously with the accumulation of energy as a hydraulic gun. What is it and why is it needed?

Recall that there are usually more than four nozzles on the body of a tall tank. Although, it would seem, quite enough entry and exit. At different levels from storage capacity you can take water with different temperatures; as a result, we can get, most typically, a high-temperature circuit with radiators and low temperature heating- warm floor.

Please note: pumps with thermal control circuits will still be needed. IN different time days at the same level of the tank, the water temperature will vary greatly.

Branch pipes can be used not only as outlets for heating circuits. Several boilers different types can also be connected to a heat accumulator.

Connection and thermal capacity

What does a heating system with a heat accumulator look like?

Heat accumulators for heating are connected in the same way as hydraulic arrows and, in general, differ from them only in thermal insulation and volume. They are placed between the supply and return pipelines leading from the boiler. The supply is connected to the top of the tank, the return to the bottom.

The secondary circuits are powered depending on what temperature of the coolant they require: high-temperature heating draws water from the top of the tank, low-temperature heating from the bottom.

Principal connection diagram.

The instruction for calculating the thermal capacity is based on a simple formula: Q = mc(T2-T1), where:

Q - accumulated heat;
m is the mass of water in the tank;
With - specific heat coolant in J / (kg * K), for water equal to 4200;
T2 and T1 - initial and final temperatures of the coolant.

Let's say a heat accumulator with a volume of two cubic meters at a temperature delta of 20C (90-70) and using water as a coolant can accumulate 2000kg (we will take the density of water as 1kg / l, although at 90C it is slightly less) x4200 J / (kg * K) x20 = 168000000 Joules.

What does this amount of energy mean? The tank can deliver 168 megawatts of thermal power in one second or, more realistically, 5 kilowatts in 33,600 seconds (9.3 hours).

Conclusion

As usual, you can learn more about heat accumulators by watching the video attached to the article (see also the water heating scheme for a private house).

Corrugated pipe for heating

The internal structure and principle of operation of the heat accumulator for heating boilers is designed to ensure that the required temperature of the heat carrier is maintained for 5-10 hours after the main energy source is turned off. storage tank is placed in a harness with solid fuel and electric boilers. Can be connected to a heat pump and solar collectors.

What is buffer capacity

In fact, this is a tank with a built-in DHW coil and a heat-insulating casing. The purpose of the tank is to accumulate excess thermal energy. After turning off the main source of heating of the coolant, the tank is on certain time replaces it.

A correctly used principle of operation of a buffer tank in a heating system reduces heating costs and makes heating a building more comfortable. To make sure that it is expedient to connect a tank, it is necessary to consider its structure and principle of operation, as well as take into account the existing advantages and disadvantages.

Device and principle of operation

The heat storage tank is an ordinary metal barrel, with external thermal insulation. A simple heat storage device, however, is different high efficiency and indispensable for heating systems. The buffer tank in the section consists of several nodes:

Tank - made of sheet metal(enamelled), stainless steel. Branch pipes depart from the tank for connection to the heating system and the heat generator. The material of the tank largely determines the service life of the heat accumulator.
Spiral heat exchanger- installed in models connected to heating systems with several types of heat carriers (heat pump, solar collectors). Made from stainless steel.
Built-in DHW coil- some buffer tanks, in addition to maintaining the heating temperature of the coolant in the heating system, heat water for hot water supply.

In the case there is an inspection window for servicing the tank, removing scale and debris, carrying out repair work if necessary.

Purpose of heat accumulators

Basis of work buffer tank due to the fact that excess thermal energy is accumulated, after which it is used to heat the building and hot water. A heat accumulator in the heating system is needed to maintain a comfortable temperature in a residential building after the main source of thermal energy is turned off.

The purpose of installing a storage tank varies depending on the type of heat source:

The tasks and purposes of using heat accumulators are different. In some cases, the installation of a tank is an indispensable condition for operation, in others it is only a desired requirement that ensures comfortable and economical heating building.

Pros and cons of buffer capacity

The first and obvious drawback: the high cost of the tank. High-quality products made in the EU or in Russia will cost from 25,000 to 300,000 rubles. Another disadvantage: the large dimensions of the product. Often it is necessary to install tanks of 1000 or more liters, which take up a lot of space.

Now about the benefits of connecting. There are several of them:

Opportunity uninterrupted operation solid fuel boilers- if a buffer tank is not installed in the heating system, the coolant begins to cool immediately after the firewood burns out. A drop in temperature is felt by a person after about 3 hours.
Cooling down will be slower when a heat accumulator is connected. The water in the heating system will remain hot for about 5-10 hours (depending on the volume of the heat accumulator).
Profitability - excess thermal energy is accumulated and used when the coolant cools down, which significantly reduces fuel costs.
Safety - the operation of boilers with cast-iron heat exchangers is facilitated. After the tank, the water enters the boiler warm, which prevents damage to the core from rapid cooling.
Additional functions- in the device of some tanks there is a DHW coil. There is a simultaneous accumulation of the heated coolant and heating of hot water. The installation can satisfy the needs for hot water supply of residents of the house using single-circuit solid fuel or electric boilers that are not designed to provide hot water.

The installation of a buffer tank requires an initial investment, but later pays off by reducing the cost of space heating and operating comfort.

Which heat accumulator to choose

It is better to entrust the selection of storage capacity to specialists. You will need to select the tank that is best suited for the type of heating equipment. Selection of a heat accumulator for a solid fuel boiler and heat pump may differ. Leading manufacturers in the operating instructions directly indicate for which type of heating system this or that buffer tank is intended.

When choosing, pay attention to several specifications:

Storage tank material- a stainless steel tank is unreasonably expensive, especially considering that the battery receives a coolant from the heating system, which is less aggressive than water in the hot water supply. Enamelled coating using glass polymers, the optimal solution.
Additional functions- it is possible to select a tank for various water consumers, connect heating systems using water as a heat carrier and special formulations(heat pump, solar collectors). Special mention should be made of tanks capable of heating water simultaneously with the accumulation of thermal energy.

The choice of heat accumulators begins with the calculation of the volume of the tank and the definition of technical characteristics. After selection by parameters, the choice is made in accordance with the brand of the manufacturer you like.

How to calculate buffer capacity

To select the required volume of the heat accumulator, you can go three ways. The first is related to the use of special online calculators. You will need to enter the following parameters:

heated area;
boiler power;
time of autonomous maintenance of temperature in the heating system after the boiler is turned off.

With the help of online calculators, it will be possible to calculate the approximate volume of a heat accumulator for a heating system. The output will be a result with an error of 10-15%.

To obtain exact value use the second method, according to the formulas for calculating the buffer capacity. During the calculations, several values are calculated:

accumulator accumulation time or water heating up to the temperature of 80-90°С;
battery life;
boiler power.

The method for calculating the buffer capacity includes the use of several formulas:

Q = m×cp×(T2-T1)- according to the calculations, it will be possible to calculate how long it will take to accumulate sufficient thermal energy and find out possible losses. Values:
- m - coolant flow rate;
- cp - specific heat capacity;
- T2 and T1 - initial and final temperature of water heating in the tank.
Using the formula, a heat accumulator is calculated for a solid fuel or electric boiler.
Calculations for solar collectors carried out somewhat differently. The formula Va=Sl × (Vn/Sn) is used. In order not to go into technical details in the calculations, you can use the following table:

There is a third calculation method, in which the calculation of water in the accumulator tank is determined depending on the volume of water in the system, more precisely, on the rate of its heating. Usually the consumer knows how many times it is necessary to heat the boiler with wood in order to maintain comfortable temperature. When calculating, the volume of the coolant is multiplied by the estimated time of autonomous operation between the laying of fuel.

And lastly, the capacity of the buffer tanks is chosen so that 30-50 liters of coolant account for 1 kW of boiler energy.

For convenience in the calculations, you can use the following table:

The determination of the minimum amount of heat produced in kW is carried out using the tables attached below.

Calculations for electric boilers, subject to the use of the night tariff:

The minimum required power to maintain the buffer tank connected to the solid fuel boiler in working condition:

Which company to buy a buffer drive

After performing the calculations and determining the desired technical characteristics, you can proceed to the selection of heat accumulators by manufacturer. Not only European products are represented on the market. There are heat accumulators for heating boilers Russian production, which are not inferior in quality to eminent foreign equipment.

To facilitate the choice of buffer capacity, the following is a description of the most popular models for domestic consumers:

From the presented list of heat accumulators, you can choose equipment suitable for housing of any size, heated by an electric or solid fuel boiler, heat pump, with and without the possibility of heating hot water.

Immediately after connecting the buffer tank, fuel costs will decrease by 15-30%. More importantly, the boiler will no longer be subjected to hydraulic shocks, and the heating of the coolant in the heating system will become more uniform. The battery tank occupies an integral place in modern systems heating.

Solid fuel boilers cannot operate for a long time without the intervention of a person who must periodically load firewood into the firebox. If this is not done, the system will begin to cool down, the temperature in the house will drop. In the event of a power outage with a fully ignited furnace, there is a danger of the coolant boiling up in the jacket of the unit and its subsequent destruction. All these problems can be solved by installing a heat accumulator for heating boilers. It can also perform a protective function cast iron installations from cracking at sharp drop supply water temperatures.

Piping of a solid fuel boiler with a heat accumulator

Calculation of the buffer capacity for the boiler

The role of the heat accumulator in the general heating scheme is as follows: during the operation of the boiler in the normal mode, accumulate thermal energy, and after the furnace is attenuated, give it to the radiators for a certain period of time. Structurally, a heat accumulator for a solid fuel boiler is an insulated water tank with an estimated capacity. It can be installed both in the furnace room and in private room Houses. It does not make sense to put such a tank on the street, since the water in it will cool much faster than inside the building.

Given the presence free space in the house, the calculation of the heat accumulator for a solid fuel boiler in practice is as follows: tank capacity is taken from the ratio of 25-50 liters of water per 1 kW of power required to heat the house. For more accurate calculation buffer tank for the boiler, it is assumed that the water in the tank will heat up to 90 ⁰С during the operation of the boiler installation, and after the latter is turned off, it will give off heat and cool down to 50 ⁰С. For a temperature difference of 40 ⁰С, the values of the heat given off for different tank volumes are presented in the table.

Table of heat output values for different tank sizes

Even if the building has a place to install large capacity, it doesn't always make sense. It should be remembered that a large number of water will need to be heated, then the power of the boiler itself should initially be 2 times more than what is needed to heat the home. Too small a tank will not perform its functions, as it will not be able to accumulate enough heat.

The choice of a heat accumulator for a solid fuel boiler is influenced by the availability of free space in the room. When buying a large storage tank, it will be necessary to provide for a foundation, since equipment with a significant mass cannot be placed on ordinary floors. If, according to the calculation, a tank with a volume of 1 m 3 is required, and there is not enough space for its installation, then you can purchase 2 products of 0.5 m 3 each, placing them in different places.

Heat accumulator for solid fuel boiler

Another point is the presence in the house DHW systems. In the event that the boiler does not have its own water heating circuit, it is possible to purchase a heat accumulator with such a circuit. Of no small importance is the value of the working pressure in the heating system, which in residential buildings traditionally should not exceed 3 bar. IN individual cases the pressure reaches 4 bar if a powerful home-made unit is used as a heat source. Then the heat accumulator for the heating system will have to choose special execution, - with torospherical cover.

Some factory-made hot water accumulators are equipped with an electric heating element installed at the top of the tank. Such a technical solution will not allow the coolant to completely cool down after the boiler is stopped, the upper zone of the tank will be heated. DHW will be supplied for household needs.

Simple switching circuit with mixing

The storage device can be included in the system by different schemes. The simplest piping of a solid fuel boiler with a heat accumulator is suitable for working with gravitational coolant supply systems and will operate in the event of a power outage. To do this, the tank must be installed above the heating radiators. The circuit includes a circulation pump, a thermostatic three-way valve and a check valve. At the beginning of the heating cycle, water, driven by the pump, passes through the supply pipeline from the heat source through the three-way valve to the heaters. This continues until the flow temperature reaches a certain value, eg 60°C.

At this temperature, the valve begins to mix cold water into the system from the lower pipe of the tank, observing the set temperature of 60 ⁰С at the outlet. Through the upper pipe, directly connected to the boiler, heated water will begin to flow into the tank, the battery will begin to charge. At complete combustion firewood in the firebox, the temperature in the supply pipe will begin to drop. When it becomes less than 60 ⁰С, the thermostat will gradually shut off the supply from the heat source and open the flow of water from the tank. That, in turn, will gradually fill up cold water from the boiler and at the end of the cycle the three-way valve will return to its original position.

The non-return valve, connected in parallel with the three-way thermostat, is activated when the circulation pump stops. Then the boiler with a heat accumulator will work directly, the coolant will go to the heating devices directly from the tank, which will be replenished with water from the heat source. The thermostat in this case does not take part in the operation of the circuit.

Schematic with hydraulic separation

Another, more complex connection scheme, implies uninterrupted supply electricity. If this is not possible, then it is necessary to provide for connection to the network through uninterruptible source nutrition. Another option is to use diesel or gasoline power plants. In the previous case, the connection of the heat accumulator to the solid fuel boiler was independent, that is, the system could work separately from the tank. In this scheme, the battery acts as a buffer tank (hydraulic separator). In the primary circuit, through which water circulates when the boiler is ignited, a special block mixing (LADDOMAT).

Connecting a heat accumulator to a solid fuel boiler

Block elements:

circulation pump;
three-way thermostatic valve;
check valve;
sump;
Ball Valves;
temperature control devices.

Differences from the previous scheme - all devices are assembled in one unit, and the coolant goes to the tank, and not to the heating system. The principle of operation of the stirring unit remains unchanged. Such a piping of a solid fuel boiler with a heat accumulator allows you to connect as many heating branches as you like at the outlet of the tank. For example, to supply radiators and underfloor or air heating systems. In addition, each branch has its own circulation pump. All circuits are separated hydraulically, excess heat from the source is accumulated in the tank and used if necessary.

Advantages and disadvantages

A heating system with a heat accumulator, in which a solid fuel installation serves as a heat source, has a lot of advantages:

Increased comfort in the house, because after the combustion of fuel, the heating system continues to heat the house with hot water from the tank. No need to get up in the middle of the night and load a portion of firewood into the firebox.
The presence of a container protects the water jacket of the boiler from boiling and destruction. If there is a sudden power outage or thermostatic heads installed on radiators cut off the coolant due to reaching the desired temperature, then the heat source will heat the water in the tank. During this time, the power supply may be restored or the diesel generator will be started.
Submission ruled out cold water from the return pipeline to the red-hot cast iron heat exchanger after sudden activation of the circulation pump.
Heat accumulators can be used as hydraulic separators in the heating system (hydraulic arrows). This makes the operation of all circuit branches independent, which provides additional savings in thermal energy.

The higher cost of installing the entire system and the requirements for equipment placement are the only disadvantages of using storage tanks. However, these investments and inconveniences will be followed by minimal operating costs in the long run.

Heat accumulator for heating boilers

We continue our series of articles with a topic that will be of interest to those who heat their homes with solid fuel boilers. We will talk about the heat accumulator for heating boilers (TA) on solid fuels. This is a really necessary device that allows you to balance the operation of the circuit, smooth out the temperature drops of the coolant, while also saving money. We note right away that a heat accumulator for electric heating boilers is used only if the house has an electric meter with separate calculation of night and day energy. Otherwise, installing a heat accumulator for gas heating boilers does not make any sense.

How does a heating system with a heat accumulator work?

A heat accumulator for heating boilers is a part of the heating system designed to increase the time between loading solid fuel into the boiler. It is a reservoir in which there is no air access. It is insulated and has a fairly large volume. There is always water in the heat accumulator for heating, it also circulates throughout the circuit. Of course, an antifreeze liquid can also be used as a coolant, but still, due to its high cost, it is not used in circuits with TA.

In addition, there is no point in filling the heating system with a heat accumulator with antifreeze, since such tanks are placed in residential premises. And the essence of their application is to ensure that the temperature in the circuit is always stable, and, accordingly, the water in the system is warm. The use of a large heat accumulator for heating in country houses of temporary residence is impractical, and there is little sense from a small reservoir. This is due to the principle of operation of the heat accumulator for the heating system.

The TA is located between the boiler and the heating system. When the boiler heats up the coolant, it enters the TA;
then the water flows through the pipes to the radiators;
The return line returns to the TA, and then immediately to the boiler.

Although the heat accumulator for the heating system is a single vessel, due to its large size, the flow direction at the top and bottom is different.

In order for TA to perform its primary function of heat storage, these streams must be mixed. The difficulty lies in the fact that the heat always rises, and the cold tends to fall. It is necessary to create conditions so that part of the heat sinks to the bottom of the heat accumulator in the heating system and heats the return coolant. If the temperature has evened out in the entire tank, then it is considered fully charged.

the warm-up time increases;
a larger volume of the circuit, which makes filling it with antifreeze more expensive;
higher installation costs.

low-temperature heating (warm floor).

Thus, even the most primitive single-circuit boiler or even a stove can become a universal heater. It will provide the entire house with the necessary heat and hot water at the same time. Accordingly, the performance of the heater will be fully utilized.

In serial models manufactured under production conditions, additional heating sources are built in. These are also spirals, only they are called electric heating elements. There are often several of them and they can work from different sources:

circuit;
solar panels.

Such heating refers to additional options and is not mandatory, consider this if you decide to make a heat accumulator for heating with your own hands.

Heat accumulator piping schemes

We dare to assume that if you are interested in this article, then most likely you decided to make a heat accumulator for heating and tie it yourself. You can come up with a lot of connection schemes, the main thing is that everything works. If you correctly understand the processes occurring in the circuit, then you can quite experiment. How you connect the HA to the boiler will affect the operation of the entire system. Let's first analyze the simplest heating scheme with a heat accumulator.

A simple TA strapping scheme

In the figure you see the direction of movement of the coolant. Please note that upward movement is prohibited. To prevent this from happening, the pump between the TA and the boiler must pump a larger amount of coolant than the one that stands up to the tank. Only in this case will a sufficient retracting force be formed, which will take part of the heat from the supply. The disadvantage of such a connection scheme is the long heating time of the circuit. To reduce it, you need to create a boiler heating ring. You can see it in the following diagram.

TA piping scheme with a boiler heating circuit

This method of installing a heat accumulator in a heating system allows you to use the circuit offline when the pump is not running. Please note that the diagram shows only the nodes for connecting the TA to the boiler. The circulation of the coolant to the radiators occurs in a different way, which also passes through the TA. The presence of two bypasses allows you to play it safe twice:

the check valve is activated if the pump is stopped and the ball valve on the lower bypass is closed;
in the event of a pump stop and a check valve failure, circulation is carried out through the lower bypass.

In principle, some simplifications can be made in such a construction. Given the fact that the check valve has a high flow resistance, it can be excluded from the circuit.

TA piping scheme without check valve for gravity system

Scheme of piping TA for a circuit with forced circulation

In TA, the correct movement of water is created, which allows ball after ball, starting from the top, to warm it up. Perhaps the question arises, what to do if there is no light? We talked about this in an article about . It will be more economical and more convenient. After all, gravity circuits are made of large-section pipes, and besides, not always convenient slopes must be observed. If you calculate the price of pipes and fittings, weigh all the inconveniences of installation and compare it all with the price of a UPS, then the idea of installing an alternative power source becomes very attractive.

Calculation of the volume of the heat storage

The volume of the heat accumulator for heating

the area of the heated room;
boiler power.

Methods for calculating the volume of TA: room area x 4 or boiler power x 25.

It is these two characteristics that are decisive. Different sources offer their own calculation method, but in fact these two methods are closely related. Suppose we decide to calculate the volume of a heat accumulator for heating, starting from the area of \u200b\u200bthe room. To do this, you need to multiply the quadrature of the heated room by four. For example, if we have a small house of 100 square meters, then we need a tank of 400 liters. This volume will reduce the loading of the boiler up to two times a day.

Undoubtedly, there are pyrolysis boilers that are loaded with fuel twice a day, only in this case the principle of operation is slightly different:

fuel ignites;
the air supply is reduced;
the smoldering process begins.

In this case, when the fuel flares up, the temperature in the circuit begins to rise rapidly, and then smoldering keeps the water warm. During this very smoldering, a lot of energy escapes into the pipe. In addition, if a solid fuel boiler works in tandem with a leaky heating system, then at peak temperatures the expansion tank sometimes boils. In the truest sense of the word, water begins to boil in it. If the pipes are made of polymers, then this is simply fatal for them.

In one of the articles about TA, it takes some of the heat and the tank can boil only after the tank is fully charged. That is, the possibility of boiling, with the right amount of TA, tends to zero.