Heat accumulators for heating. Buffer tank (heat accumulator) for the heating system

The main objectives of the design and installation of the system autonomous heating are comfort in the home and trouble-free operation. Therefore, those people who believe that to achieve comfort it is enough to simply install a boiler and connect it to the heating system are mistaken.

And this mistake lies in the fact that sooner or later any boiler, even the best quality, can fail. And most often this happens in the midst of heating season, when the equipment operation mode is most intensive. How can you insure yourself in such a case?

There are several options:

Have a regular stove in your home that is in working order.
Have two boilers, one of which, with a lower power, is used only in an emergency.
Include a device in the heating system that allows you to accumulate thermal power during operation of the boiler, capable of maintaining the temperature of the coolant at the proper level for a sufficiently long time when it stops.

The first option is good for those houses that previously had stove heating, and then were equipped with their own boiler room. It is unlikely that anyone will build a stove in a new house, for which heating from a boiler was initially provided. The second option is used infrequently, but has a right to life. Usually the main one here is a solid fuel and gas unit, and the backup one is an electric boiler of not too high power, used exclusively as a backup heat source.

But the third option from the point of view of reliability is the most optimal. Such a device is called a heat accumulator and is most often used in systems equipped with periodic boilers. Most often this solid fuel boilers(needing to be loaded with fuel several times a day) and electric units that are profitable to turn on only at night (if electricity is cheaper at night).

What is a heat accumulator (TA)

A heat accumulator is a reservoir of a certain (rather large) capacity filled with a coolant (usually water). The tank must be well insulated from the external environment. At the same time, during operation of the boiler, due to the high heat capacity of water, the coolant is heated throughout the entire volume of the tank. Due to this, a large reserve of thermal power is created, providing stable work heating and hot water supply systems (if any) during the entire boiler downtime. Moreover, the reason for the downtime is not important - it could just be a break between fireboxes or an accident.

With a sufficient tank volume, even a large house can last up to 2 days. At the same time, the temperature in it will drop by only 2-3 degrees. This is the most obvious and understandable advantage of having a heat accumulator in the home heating system. In fact, its capabilities are much wider. Indeed, in fact, it significantly increases the volume of coolant in the heating system circuit. At the same time, its indicators such as heat capacity and inertness also increase.

That is, the system warms up more slowly, absorbing more energy, but it also cools down for a very long time, maintaining the temperature in the house even when the boiler is not working.

There are a number of situations in which the presence of a heat accumulator in the system greatly simplifies and reduces the cost of achieving the desired results.

Fuel burns best when the boiler is operating in maximum power. But in spring and summer this power is clearly excessive. And the presence of a water tank will allow you to quickly heat the water in it to desired temperature and stop the combustion process, saving fuel and time for boiler maintenance.

Solid fuel boilers have a minimum power during ignition; as the fuel burns, it reaches a maximum, and then drops again. This mode is not very useful for the operation of the heating system - the temperature of the coolant in it constantly fluctuates. The presence of a heat accumulator allows you to maintain the temperature in the system at an optimal level.

If the system has several sources of heating the coolant, and one of them is a solid fuel boiler, then connecting the others becomes very difficult. A coolant reservoir allows you to organize such connections easily and at low cost.

If it is necessary to organize hot water supply in the house, then you have to install an additional heat exchanger in the boiler or use a boiler indirect heating. All this negatively affects the operation of the heating system. And here is a large reservoir with hot water makes it easy to get out of the situation.

Thus, the TA is a decoupling unit between the heating circuit and the boiler, allowing minimal costs implement various additional functions.

To do this, you need to build on the following data:

heating unit power;
the time during which the coolant in the heat exchanger must warm up;
the time for which the thermal power accumulated in the reservoir should be enough to cover the heat loss of the house.

For correct selection it is necessary to know the thermal power of the heater.

It is calculated using the formula:

Q = m × C × (T2 – T1),

where m is the mass of the coolant (depending on the volume of the heat exchanger), kg;
C – specific heat capacity of the coolant;
T2 – T1 is the difference between the final and initial water temperatures. Usually it is taken equal to 40 degrees.

One ton of water, when cooled by 40 degrees, releases 46 kWh of heat.

If you want to switch the boiler to periodic operation, for example, only to night or day mode, then the power of the boiler should be enough to heat the house for the remaining time.

Let's give an example. Suppose you use a solid fuel boiler that operates only during the daytime for 10 hours. In this case, the heat loss of the house is 5 kW, then per day 5 × 24 = 120 kW*h of thermal power will be required to maintain the heating function. The TA will be used for 14 hours. This means that it should accumulate: 5 × 14 = 70 kWh of heat. If the coolant is water, then its weight should be 70: 46 = 1.52 tons. With a margin of 15% this will be 1.75 tons, then the volume of the heat exchanger should be approximately 1.75 cubic meters. m.

Do not forget that the boiler power should be sufficient to produce 120 kWh of energy in 10 hours of operation. That is, its power must be at least 120: 10 = 12 kW.

If the heater is used only for the safety of the heating system in case of an accident, then the reserve of thermal power in it should be enough for 1-2 days. That is, the power reserve must be at least 120 - 240 kWh. Then the volume of TA will be: 240: 46 = 5.25 cubic meters. m.

This approximate calculations, however, they allow you to get a rough idea of TA parameters.

There are simpler ways to calculate the volume of TA:

Volume equal to area premises in meters multiplied by 4. For example, a house has an area of 120 square meters. m. Then the volume of the tank should be: 120 × 4 = 480 l.
The boiler power is multiplied by 25. For example, the boiler has a power of 12 kW, then the volume of the tank will be 12 × 25 = 300 liters.

You can make a reservoir for heating the coolant yourself or purchase a ready-made one. Self-production is associated with the difficulties of taking into account the characteristics and features of future equipment. Not only the price of the issue will depend on this, but also the performance of the TA, as well as its durability.

The main operating parameters of heat accumulators are:

Weight, volume and dimensions. The volume of the tank is selected according to the power of the boiler. But the larger its volume, the more economically the system as a whole will operate. A large heat exchanger will take longer to heat up, but the time between firing the boiler will also increase. If the tank is too large according to calculations and does not fit into the allocated room, then you can use several smaller containers.
Pressure in the heating system. The thickness of the TA walls, as well as the shape of its bottom and lid, depend on this value. If the pressure in the system is no more than 3 bar, then the most common heat accumulators can be used. If the operating pressure is in the range of 4-8 bar, then you need to choose tanks with torispherical lids. Such equipment will cost more.
The material from which the tank is made. Most often this is standard carbon steel coated with waterproof paint. But if possible, it is better to choose a tank from of stainless steel. It is more resistant to additives contained in the coolant and corrosion.
Maximum fluid temperature.
Availability of the possibility of installing additional equipment: heating elements, a built-in heat exchanger for connecting to the hot water system, additional heat exchangers for organizing connection to other sources of heating the coolant.

How to install a heat storage tank

The most in a simple way The installation is a vertically located TA, into the walls of which there are 4 pipes embedded, two on each side. Each pair is spaced vertically. On one side, the upper pipe is connected to the supply line of the boiler unit, and on the other, to the supply branch of the heating system. Below, on the corresponding sides of the tank, there are pipes connected to the return lines of the boiler and the heating circuit.

The return pipelines of the boiler and heating circuit are equipped with circulation pumps.

After loading fuel into the boiler and achieving stable combustion, turn on the circulation pump, supplying water from the bottom of the heat exchanger to its heating zone. At the same time, in parallel, hot coolant used for heating the premises is supplied to the heating unit through the upper pipe.

In this case, active mixing of cold and hot water in the tank does not occur - this is prevented different densities water different temperatures.

After the fuel burns out, the tank is filled with water at the required temperature. After this, the circulation pump of the heating circuit is turned on, which pumps heated water through the system. Due to the fact that the coolant enters the system through the upper pipe, and the water spent in the system and already cooled enters from below, mixing of layers of water of different temperatures does not occur, and TA long time supplies water to the system required temperature.

Types of TA depending on design

Depending on the functional purpose, all heat accumulators are divided into the following types:

Empty - with direct connection of circuits. In such a system, no heat exchangers are used, and the separation of cold and hot water is ensured only by the difference in their density. Homemade TAs usually have exactly this design.
With built-in boiler. Inside the main tank there is an additional container intended for heating water in the DHW system.
With internal heat exchanger. This model allows you to separate coolants in the circuits of the boiler and heating system. The separation of liquids is ensured by the walls of the heat exchanger.

What does the heating equipment market offer?

Our market has products from well-known foreign companies:

Buderus (Germany) - produces universal TAs that can be used to work with solid fuel boilers of any other brands. Tanks are made from carbon steel and are equipped with insulation from a layer of foam plastic 100 mm thick.
Hajdu is a Hungarian product that is attractive due to its good price-quality ratio. The thickness of the insulation layer is also 100 mm.
Lapesa is a Spanish company that produces heat accumulators not only for household but also for industrial use. For thermal insulation of tanks, polyurethane foam is used, which ensures extremely low heat loss.
NIBE (Sweden) - produces models that allow the use of various coolant heating units (heat pump or solar collector). The thermal insulation of the tanks is a layer of polystyrene foam 80 mm thick.
S-TANK is a Belarusian product. It is of high quality and affordable price. Can work with low quality water. Has anti-corrosion protection in the form of an enamel layer.
GOPPO are Russian heat accumulators for heating systems, designed for pressures of 3 and 6 bar. They have 30 mm thick polyethylene foam insulation.

Choosing a heating system for the heating system of a private home is a responsible matter. If the heating installation is carried out by a specialized company, then you don’t have to worry about the correct selection of heating equipment. If you decide to do this yourself, then try to take into account all the listed parameters and choose a tank with at least a small reserve of volume.

Heating with wood or coal is not very pleasant. You have to heat it often, especially in cold weather; it takes a lot of time and effort. In addition, the fluctuating temperature - sometimes cold, sometimes hot - does not bring joy either. These problems can be solved by installing a heat accumulator (heat accumulator) for heating.

What is a heat accumulator for heating?

In the simplest case, a heat accumulator for a heating system is a container filled with coolant (water). This container is connected to the heating water boiler and to the heating system (through pipes of a suitable diameter). In more complex devices, a heat exchanger is located inside the container, connected to the heating boiler. The hot water supply comb can also be powered from this container through another heat exchanger.

Heat accumulators for heating are usually made of steel - regular, structural or stainless steel. They can be cylindrical or parallelepiped-shaped (square). Since they are designed to retain heat, much attention is paid to insulation.

What is it needed for

Installation of a thermal accumulator (TA) for individual heating can solve several problems at once. Most often, TAs are placed where they are heated with wood or coal. In this case, the following tasks are solved:

A water tank is a guarantee that the water in the system will not overheat (if the length of the heat exchanger and the tank capacity are correctly calculated).
Using the heat accumulated in the coolant, normal temperature is maintained after the fuel load has burned out.
Due to the fact that there is a reserve of heat in the system, you need to heat it less often.

All these considerations force you to buy a very expensive heat accumulator for heating.

Some craftsmen make. This is an economical option, but it also costs at least 20-50 thousand rubles. With a purchased TA you will have to spend many times more than with a homemade one.

Heat accumulators are not cheap, but the result of their use is worth it. Firstly, it increases safety (the heating system will not boil, pipes will not burst, etc.). Secondly, you won’t have to heat it so often. Thirdly, a more stable temperature, since the container with water is a buffer that smoothes out temperature fluctuations that characterize heating with wood and coal (it’s hot, then it’s cool). Therefore, these devices are also called “ buffer capacity for heating."

Connecting two boilers via a buffer tank is easy and simple

Separately, it is worth mentioning the saving of firewood and coal. In a heating system without TA, on relatively warm days it is necessary to limit the access of air, reducing the combustion intensity. Otherwise the house is too hot. Since conventional solid fuel (SF) boilers are not particularly designed for such modes, the efficiency of the boiler in this case is very low. Most of the heat simply flies into the chimney. In the case of an installed water heat accumulator, everything is exactly the opposite: you do not need to limit combustion. The faster the water heats up, the better. It is only important to correctly calculate the system parameters.

Another option is a heat accumulator for heating with a built-in tubular electric heater (TEH). This makes it possible to further increase the time between starts of the solid fuel boiler. Moreover, if there is a night tariff in your region, you can turn on the electric heating at night. Then it won’t hurt your wallet so much. You can also solve the problem of insufficient power of the selected and installed heating boiler.

There are other areas of application. For example, some owners install two boilers. To reserve just in case, since one type of fuel is not always available. This practice is quite common. Connecting them via a heat accumulator greatly simplifies the wiring. There is no need to install a lot of shut-off and control valves. Put the boilers into a heat accumulator - and that’s all there is to it. By the way, you can connect to the same container. They also easily fit into such a scheme. By the way, the heat stored on a sunny day with the help of solar collectors can be heated for up to two days.

Owners of electric boilers install a buffer tank to save money. Yes, this increases the volume of coolant that has to be heated, but the boiler is started during the reduced tariff - at night. During the day, the temperature is simply maintained by the heat that is “stored” in the heat accumulator. How profitable this method is depends on the region. In some regions, night rates are significantly lower than day rates, i.e. It is quite possible to make heating cheaper.

How to calculate the volume of TA

In order for a heat accumulator for heating to perform its functions, its volume must be selected correctly. There are several methods:

by heated area;
by boiler power;
according to the time available.

Most of the methods are based on experience. For this reason, there is a “fork” in the recommendations. For example, from 35 to 50 liters per square meter of heated area. How exactly to determine the number? It is worth taking into account the region of residence and the degree of insulation of the house. If you live in a region with not the most severe winters or the house is well insulated, it is better to take it at the lower limit or so. Otherwise - on the top.

When choosing the volume of a heat accumulator for heating, two points must also be taken into account. First - a large number of water will allow you to heat it much less often. Due to the stored heat, the temperature can be maintained for a long time. But, on the other hand, the time it takes to “accelerate” this volume to the required temperature greatly increases (heating to 85-88°C is considered normal). In this case, the system becomes very inertial. You can, of course, take a more powerful boiler, but paired with a buffer tank, this will cost a considerable amount. Therefore, you have to maneuver, finding the optimal solution.

By heated area

You can select the volume of the heat accumulator for the heating system according to the area of the room. It is believed that by ten square meters 35 to 50 liters are needed. The selected value is multiplied by the quadrature divided by ten to obtain the desired volume.

For example, in the heating system of a house with an area of 120 m² with average insulation, it is better to install a heat accumulator for heating 120 m² / 10 * 45 l = 12 * 45 = 540 liters. This will not be enough for the Middle Zone, so you should look at containers with a volume of approximately 800 liters.

In general, to make it easier to navigate, for a house with an area of 160-200 square meters, located in Middle lane, with average insulation, the optimal tank volume is 1000-1200 liters. Yes, with such a volume, you will have to heat it more often in cold weather. But this will not undermine your budget too much, and will allow you to live quite comfortably almost all winter.

By boiler power

Since the boiler will have to work on heating the water in the tank, it makes sense to calculate the volume based on its capabilities. In this case, 50 liters of capacity are taken per 1 kW of power.

You can make it even simpler - use the table (the values that are optimal in terms of cost and performance are shaded in yellow)

The calculation is simple. For a 20 kW boiler, a TA of 1000 liters is suitable. With such a volume of heat storage for heating, you will have to heat it twice a day.

According to the desired duration of downtime and heat loss

This method is more accurate, as it allows you to select dimensions specifically for the parameters of your home (heat loss) and your wishes (duration of downtime).

Let's calculate the volume of a heat accumulator for a house with a heat loss of 10 kW/hour and an idle time of 8 hours. We will heat the water to 88 °C, and it will cool down to 40 °C. The calculation is as follows:

For these conditions, the required capacity of the heat accumulator for heating is 1500 liters. This is because heat loss of 10 kW/hour is too much. This is a house with virtually no heating.

Types of buffer tanks, features of their use

We will talk about the “filling” of heat accumulators for heating. Outwardly, they all look the same, but the inside may be completely empty, or there may be heat exchangers. Usually this is a pipe - smooth or corrugated - twisted into a spiral. It is by the presence, quantity and location of these spirals that a heat accumulator for heating is distinguished.

Buffer tanks for heating systems come with different “fillings”

Without heat exchanger

Essentially, it is just a thermally insulated tank with direct connection to the boiler and consumers. Such a heat accumulator can be used in systems where the same coolant is acceptable. For example, you can’t connect the hot water supply like that. Even if water is used as a coolant, its composition is far from drinking water or even that which can be used for domestic needs. As a technical one, it’s possible, but not in all cases.

The second limitation is the pressure on consumers. In any operating mode, the operating pressure of consumers must be no lower than the pressure in the boiler and the tank itself. Since the system is single, the pressure will be common. Everything is clear here and no explanation is required.

The third limitation is temperature. The maximum temperature at the boiler outlet should not exceed the permissible temperatures of all other system components. This also requires no explanation.

A heat accumulator without a heat exchanger is simply a sealed insulated container with pipes for connecting the boiler and consumers

Basically, this is the most cheap option heat accumulator for heating, but the choice is not the best. The fact is that the boiler heat exchanger will not last long. The entire considerable volume of water will be pumped through it and a considerable amount of salts will be deposited. And if there is also a water consumption - as a hot water supply - then the source of salts will become inexhaustible, as it will be replenished with fresh water from the tap. So we install a heat accumulator without a heat exchanger as a last resort - if we really don’t have the funds for more expensive devices.

With a heat exchanger in the lower or upper part of the tank, with two (bivalent)

Installing a heat exchanger connected to the boiler solves many problems. A small volume of coolant circulates through this circle and does not mix with the rest. So a lot of salts will not be deposited on the boiler heat exchanger. In addition, problems with pressure and temperature are eliminated. Since the circuit is closed, the pressure in it does not affect the rest of the system and can be any within a reasonable range.

Temperature restrictions remain: it is important that the coolant does not boil. But this can be solved - there are special ways to solve it.

But where is it better to install the heat exchanger from the boiler in the heat accumulator - at the top or at the bottom? If you place it at the bottom, there will be constant movement in the container. The heated coolant will rise up, the colder one will fall down. This way all the water in the container will be more or less the same temperature. This is good if you need the same temperature for all consumers. In such cases, heat accumulators with a lower heat exchanger are chosen.

If the boiler spiral is located in the upper part, the coolant is heated layer by layer. The most heat It turns out in the upper part, gradually decreasing downwards. This temperature stratification can be useful if you supply water at different temperatures. For example, you can feed it hotter into radiators. The pipes going to them must be connected to the topmost terminals. The heated floor needs a warm coolant - we take it from the middle. So this is a good option too.

There are also heat accumulators with two heat exchangers. Outputs from different heat sources are connected to them. This could be two boilers, a boiler + solar collectors, or other options. Here you just have to decide which source to connect up and which down. In some TA models, spiral heat exchangers are nested one inside the other. Then everything is simpler - you figure out which source can heat the larger volume, and connect it to an external heat exchanger. The second is to the internal.

Options for DHW

Installing a heat accumulator solves the problem of hot water supply. There are several ways to provide water heating for technical needs.

As already mentioned, heated water can be taken directly from the tank. But its quality will be technical. Do you want to use this for showering, bathing, washing dishes - no questions asked. No - you will have to install a heat accumulator with a special heat exchanger and connect it to the comb cold water, tie. But the water will be of proper quality.

Another option is a heat accumulator with a built-in hot water tank. Applicable for cases when warm water It is not needed at a time when the coolant is actively heating. The tank located in the upper part retains heat, so that even when the rest of the volume cools, the water remains warm. Tanks can be additionally equipped with heating elements. This will make it possible to have water at the desired temperature in any case.

What are the benefits of a heat accumulator for heating with a built-in hot water tank? Space is saved. To place a heat exchanger and an indirect heating boiler next to each other will require much more space. The second advantage is that there are small cost savings. Minus - if the buffer tank fails, you lose both hot water and heating.

When using a gas boiler, we do not need to independently maintain a certain temperature in the heating circuit - this is done automatically. But everything changes when a solid fuel boiler is installed in the house. The fuel in it burns unevenly, which leads to cooling or overheating of the heating system. A heat accumulator for heating will help compensate for these fluctuations and stabilize the temperature in the circuit. Spacious storage tank will be able to retain excess thermal energy, gradually releasing it into the heating system.

In this review we will look at:

How heat accumulators for heating systems work;
How to calculate the required volume of a battery tank;
How storage tanks are connected;
The most popular models of thermal storage devices.

Let's go through these points in more detail.

Operating principle of heat accumulators

If you install a solid fuel boiler in your house, there will be dire necessity in regularly adding new portions of firewood. It's all about the limited volume of the combustion chamber - it cannot accommodate an unlimited number of logs. And their systems automatic feeding haven’t come up with it yet, if you don’t take into account pellet boilers with automation. In other words, you will have to monitor the operation of the heating system yourself.

These boilers develop maximum power at the moment when firewood is happily blazing in them. At this moment, they provide a lot of excess energy, so users dose the firewood carefully, placing it one log at a time. Otherwise the house will be too hot. There is nothing good about this, since this increases the number of approaches, which is already high. The problem is solved using a heat accumulator.

A heat accumulator for heating is a storage tank in which hot coolant accumulates. Moreover, energy is supplied to the heating circuit in a strictly dosed manner, which ensures temperature stability. Due to this, household members get rid of temperature fluctuations and frequent trips to lay firewood. Storage tanks are capable of accumulating excess thermal energy and smoothly releasing it into heating circuits.

Let's try to explain the principle of operation on the fingers:

The simplicity of the thermal accumulator design not only increases the reliability of the unit, but also simplifies repairs and scheduled maintenance.

Installed in a heating system with a heat accumulator, the heating boiler is loaded with firewood and produces a large amount of thermal energy;
The resulting energy is sent to a thermal battery and accumulates there;
At the same time, with the help of a heat exchanger, heat is collected for the heating system.

The buffer tank for heating (also known as a heat accumulator) operates in two modes - accumulation and release. In this case, the boiler power may exceed the required thermal power to heat the home. While the wood is burning in the firebox, heat will accumulate in the thermal accumulator. After the logs go out, energy will continue to be drawn from the battery for a long time.

Lazhebok’s heat accumulators for greenhouses and greenhouses are designed in approximately the same way - during the day they accumulate heat from the sun, and at night they release it, warming the plants and preventing them from freezing. They just look a little different.

Heat accumulators for heating systems are also necessary if solar panels or heat pumps are used as a heat source. The same batteries cannot provide heat around the clock, since dark time days, their effectiveness drops to zero. During daylight hours, they will not only heat the house, but also accumulate thermal energy in the storage tank.

Heat accumulators can be useful when using electric boilers . This scheme justifies itself on a two-tariff payment system. In this case, the system is configured so that heat accumulation occurs at night, and its release begins during the day. Thanks to this, consumers have the opportunity to save money on energy consumption.

Types of heat accumulators

The heat accumulator for the heating system is a capacious tank equipped with solid thermal insulation - it is responsible for minimizing heat loss. Using one pair of pipes, the battery is connected to the boiler, and using the other pair, to the heating system. Additional pipes may also be provided here to connect the DHW circuit or additional sources of thermal energy. Let's look at the main types of heat accumulators for heating systems:

With a circulation pump, it becomes possible to use several buffer tanks at once, which allows you to evenly heat several rooms at once.

Buffer tank is a simple tank without internal heat exchangers. The design provides for the use of the same coolant in the boiler and batteries, at the same permissible pressure. If you plan to pass one coolant through the boiler and another through the batteries, you should connect an external heat exchanger to the heat accumulator;
Heat accumulators for individual heating with lower, upper or several heat exchangers at once - such heat accumulators allow you to organize two independent circuits. The first circuit is a tank connected to the boiler, and the second is a heating circuit with radiators or convectors. The coolants do not mix here; there may be different pressures in both circuits. Heating is carried out using a heat exchanger;
With a flow-through heat exchanger of the DHW circuit or with a tank - for organizing hot water supply. In the first case, water can be consumed throughout the day and evenly. The second scheme involves the accumulation of water for the purpose of its rapid release to certain time(for example, in the evening, when everyone takes a shower before going to bed) - indirect boilers that accumulate water are designed in a similar way.

The design of heat accumulators for heating can be very different, the choice suitable option depends on the complexity of the heating system, its characteristics and the number of sources of hot coolant.

Some heat accumulators are equipped with heating elements with thermostats, which makes it possible to provide consumers with heat at night, when the coolant has already cooled down and there is no one to throw firewood into the firebox. They are also useful when using heat pumps and solar panels.

Calculation of heat accumulator volume

We have come close to the most difficult issue - calculating the required volume of the heat accumulator. To do this, we will use the following formula – m=W/(K*C*Δt). The letter W denotes the amount of excess heat, K is the efficiency of the boiler (we indicate decimal), C is the heat capacity of water (coolant), and Δt is the temperature difference, determined by subtracting the temperature of the coolant on the return pipe from the temperature on the supply pipe. For example, it can be 80 degrees at the outlet and 45 at the return - in total we get Δt=35.

First, let's calculate the amount of excess heat. Let's assume that for a house with an area of 100 sq. m. we need 10 kW of heat per hour. The burning time on one stack of firewood is 3 hours, and the boiler power is 25 kW. Consequently, in 3 hours the boiler will generate 75 kW of heat, of which only 30 kW needs to be sent for heating. In total, we are left with 45 kW of excess heat - this is enough for another 4.5 hours of heating. In order not to lose this heat and not reduce the amount of loaded firewood (otherwise we will simply overheat the system), you should use a heat accumulator.

As for the heat capacity of water, it is 1.164 W*hour/kg*°C - if you don’t understand physics, just don’t go into details. And remember that if you use a different coolant, its heat capacity will be different.

Having carried out the necessary calculations using our advice, you can easily select the model that most accurately satisfies all your needs.

In total, we have all four values - this is 45,000 W of heat, the efficiency of the boiler (let's assume 85%, which in fractional calculations will be 0.85), the heat capacity of water is 1.164 and the temperature difference is 35 degrees. We carry out calculations - m=45000/(0.85*1.164*35). With these figures, the volume is equal to 1299.4 liters. We round up and get the capacity of the heat accumulator for our heating system equal to 1300 liters.

If you cannot carry out the calculations yourself, use special calculators, auxiliary tables or the help of specialists.

Connection diagrams

The simplest scheme for connecting a heat accumulator to a solid fuel boiler involves using the same coolant at equal pressure in the boiler and the heating system. For these purposes, the simplest storage tank without heat exchangers is suitable. Two pumps are installed on the return pipes - by adjusting their performance, we will ensure temperature control in the heating system. There is a similar scheme using three way valve– it allows you to regulate the temperature by mixing the hot coolant and the cooled coolant from the return pipe.

Heat accumulators with a built-in heat exchanger are designed to work in heating systems with high pressure coolant. To do this, heat exchangers are located inside them, connected through a circulation pump to the boilers - this is how a supply circuit is formed. The internal storage tank with a second circulation pump and batteries forms a heating circuit. Different coolants can circulate in both circuits, for example, water and glycol.

The design of a solid fuel boiler with a heat accumulator and a hot water circuit allows for the supply of hot water without the use of dual-circuit equipment. For this purpose, internal flow-through heat exchangers or built-in tanks are used. If hot water is needed throughout the day, we recommend purchasing and installing a heat accumulator with a flow exchanger. For peak one-time consumption, batteries with hot water tanks are optimal.

Bivalent and multivalent connection schemes have also been developed - they involve the use of several heat sources at once for heating operation. For this purpose, heat accumulators with several heat exchangers can be used.

Popular models

It's time to understand the most popular models of heat accumulators for heating systems. We will consider products from domestic and foreign manufacturers.

The manufacturer of Prometheus heat accumulators is the Novosibirsk company SibEnergoTerm. It produces models with volumes of 230, 300, 500, 750 and 1000 liters. The equipment warranty is 5 years. The heat accumulators are equipped with four outlets for connection to heating and heat sources. A layer of thermal insulation made of mineral wool is responsible for preserving the accumulated energy. The working pressure is 2 atm, the maximum is 6 atm. When purchasing equipment, take into account its dimensions - for example, the diameter of a 1000-liter model is 900 mm, which is why its body may not fit into standard doorways 80 cm wide.

The price of the presented heat accumulator for heating systems varies in the range from 65 to 70 thousand rubles.

Another capacious heat accumulator for 1000 liters of water. It is equipped with one or two smooth-tube heat exchangers, but lacks thermal insulation, which must be taken into account when installing it - it will have to be purchased separately. The diameter of the case is 790 mm, but if thermal insulation is added to it, the diameter increases to 990 mm. The maximum temperature in the heating system is +110 degrees, in the DHW circuit – up to +95 degrees.

These heat accumulators are available in modifications with six or ten connections. Temperature sensor terminals are also provided on board. The tank capacity is 960 liters, operating pressure is up to 3 bar. The thickness of the thermal insulation layer is 80 mm. The use of liquids other than water as a coolant is not allowed - this applies to both circuits, and not just the heating circuit. If necessary, it is possible to connect several heat accumulators in series into a single cascade.

Homemade heat accumulators

Nothing prevents you from assembling a heat accumulator for a heating system with your own hands - for this you need to carry out calculations and draw a drawing, focusing on the required capacity. Tanks are constructed from sheet metal 1-2 mm thick, cut with a plasma cutter, cutting machine or welding machine. Heat exchangers are organized from metal straight or corrugated pipes. And in order to avoid rapid corrosion of the metal, you need to purchase a magnesium anode. Basalt wool can be used as thermal insulation.

As a bonus, we provide a detailed drawing of a heat accumulator with a capacity of 500 liters - this is enough to maintain the operation of the heating system in a small house.

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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 tell you about a heat accumulator for heating boilers (HS) using solid fuel. This is a really necessary device that allows you to balance the operation of the circuit, smooth out temperature changes in the coolant, and also save money. Let us immediately note 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 makes no 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 loads solid fuel into the boiler. It is a reservoir into 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, and it circulates throughout the entire circuit. Of course, non-freezing 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 a heating system with a heat accumulator with antifreeze, since such tanks are placed in residential premises. And the essence of their use is to ensure that the temperature in the circuit is always stable, and therefore the water in the system is warm. Application of a large heat accumulator for heating in country houses temporary residence is impractical, and a small tank is of little use. This is due to the operating principle of the heat accumulator for the heating system.

TA is located between the boiler and the heating system. When the boiler heats the coolant, it enters the heat exchanger;
then the water flows through pipes to the radiators;
the return flow returns to the TA, and then directly to the boiler.

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

In order for the TA to perform its main function of storing heat, these flows must be mixed. The difficulty is that high temperatures always rise, and cold tends to fall. It is necessary to create such 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 is equalized throughout the tank, then it is considered fully charged.

After the boiler has burned out everything that was loaded into it, it stops working and the 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 accumulator for heating is small, then its reserve will last only for a short time, while the heating time of the batteries increases, since the volume of coolant in the circuit has become larger. Disadvantages of using for temporary residences:

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

As you understand, filling the system and draining water every time you come to your dacha is troublesome, to say the least. Considering that the tank alone will be 300 liters, it makes no sense to take such measures for the sake of a few days a week.

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

low temperature heating (warm floor).

Thus, even the most primitive single-circuit boiler or even 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 heater's performance will be fully used.

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 is an additional option and is not mandatory; keep this in mind if you decide to make a heat accumulator for heating with your own hands.

Heat accumulator wiring diagrams

We dare to suggest that if you are interested in this article, then, most likely, you have decided to make a heat accumulator for heating and its wiring with your own hands. You can come up with many connection schemes, the main thing is that everything works. If you correctly understand the processes occurring in the circuit, then you can experiment. How you connect the TA to the boiler will affect the operation of the entire system. Let's first look at the most simple diagram 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 heating element and the boiler must pump a larger amount of coolant than the one that stands before the tank. Only in this case will a sufficient drawing force be generated, which will remove part of the heat from the supply. The disadvantage of this 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.

Scheme of piping TA with boiler heating circuit

The essence of the heating circuit is that the thermostat does not add water from the heater until the boiler warms it up to established level. When the boiler has warmed up, part of the supply goes into the TA, and part is mixed with 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 become warm faster.

This method of installing a heat accumulator in a heating system allows you to use the circuit in autonomous mode when the pump will not work. Please note that the diagram shows only the connection points of the heating unit to the boiler. The coolant circulates to the radiators in a different way, which also passes through the heat exchanger. The presence of two bypasses allows you to be on the safe side twice:

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

In principle, some simplifications can be made to this design. Given the fact that the check valve has high flow resistance, it can be excluded from the circuit.

TA piping diagram without a check valve for a gravity system

In this case, when the light goes out, you will need to manually open the ball valve. It should be said that with such a layout, the TA must be located above the level of the radiators. If you do not plan for the system to operate by gravity, then connecting the heating system to the heat accumulator can be done according to the diagram shown below.

TA piping diagram for a circuit with forced circulation

The correct movement of water is created in the TA, which allows it to be heated ball by ball, starting from the top. The question may arise, what to do if there is no light? We talked about this in an article about . It will be more economical and convenient. After all, gravity contours are made of large-section pipes, and in addition, inclines that are not always convenient must be observed. If you calculate the price of pipes and fittings, weigh all the installation inconveniences and compare all this with the price of a UPS, then the idea of installing an alternative power source will become very attractive.

Calculation of heat storage volume

Heat accumulator volume for heating

As we have already mentioned, it is not advisable to use small volume TAs, and tanks that are too large are also not always appropriate. So the question has arisen about how to calculate the required volume of TA. I really want to give a specific answer, but, unfortunately, there cannot be one. 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 has and you can't find out, for example, if it hasn't been built yet. By the way, to reduce heat loss, you need . You can select a tank based on two values:

area of the heated room;
boiler power.

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

It is these two characteristics that are decisive. Different sources offer their own method of calculation, but in fact these two methods are closely interrelated. Suppose we decide to calculate the volume of a heat accumulator for heating, based on the area of the room. To do this, you need to multiply the square footage of the heated room by four. For example, if we have little house 100 sq. m., then you will need a tank of 400 liters. This volume will allow reducing the boiler load to twice a day.

Undoubtedly, this is the case pyrolysis boilers, in which fuel is added twice a day, only in this case the operating principle is slightly different:

the fuel flares up;
air supply decreases;
the smoldering process begins.

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

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

Now let's try to calculate the volume of the heater based on the number of kilowatts in the heater. By the way, this indicator is calculated based on the square footage of the room. At 10 m 1 kW is taken. 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 heating unit. 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 takes 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 matter, as in any other, one must do without fanaticism. If you install a TA for two thousand liters, then the heater simply cannot cope with such a volume. Be objective.

Companies involved in the development of engineering systems last years focus on the development of alternative technological solutions. Concepts and directions that do not involve the use of natural resources. At the very least, experts strive to minimize their consumption. A tangible benefit in this segment is demonstrated by a heat accumulator for a heating system, which is included in the existing engineering complex as an additional optimization component.

General information about heat accumulators

There are many modifications and varieties of heat accumulators, which are also called buffer heaters. The tasks that such installations perform are also different. As a rule, batteries are used to increase the efficiency of the main unit, for example a solid fuel boiler. In these cases, it is advisable to use such systems to carry out a monitoring function, which is difficult to implement in the process of servicing traditional boiler rooms in private homes. Most often, heat storage tanks with a capacity of up to 150 liters are used for this. In the industrial sector, of course, installations with a capacity of about 500 liters can also be used.

The tank itself contains elements that ensure maintenance of the required temperature of the medium. The very material from which the tank is made is mandatory interfaces with layers of insulators. Active components are heating elements and copper pipes. The configuration of their placement in tanks may differ, as well as the systems for controlling the operating parameters of the battery.

Operating principle

From a storage drive's point of view, the main task is to ensure that the desired temperature regime, which is specified by the user himself. As the boiler operates, the tank receives hot water and stores it until the heating system stops functioning. Conditions for maintaining temperature balance are determined insulating materials containers and internal heating elements. A classic heat accumulator for a heating system, in essence, resembles the operation of a boiler and is also integrated into the system. That is, on the one hand, the equipment is connected to a heat source, and on the other, it ensures the operation of direct heaters, which can be radiators. In addition, the system is often used as a full-fledged source of hot water for domestic needs in constant consumption mode.

Functions of thermal accumulators

As already noted, units of this type can perform different tasks, the requirements for which determine the criteria for choosing a particular system. The basic and main functions include the accumulation of heat from the generator and its subsequent release. In other words, the same tank collects, stores and transfers energy to the direct heating element. In combination with solid fuel boiler The system's functions also include overheating protection. Automated and electronic control relays are ineffective in solid fuel units. Therefore, it is practiced to optimize the operation of the boiler using a heat accumulator, which naturally collects excess energy and returns it during temperature drops. Electric, gas and liquid generators are easier to control, but with the help of a battery they can be connected into a single complex and operated with minimal heat loss.

Where can a thermal accumulator be used?

It is advisable to use a heat storage system in cases where the existing heating unit does not allow sufficient control of its operation. For example, solid fuel boilers inevitably provide for maintenance moments when their capacities are not loaded. To compensate for heat loss, it makes sense to use such a system. Also, in the operation of water and electric heating systems, this solution is economically justified. A modern heat accumulator with automatic control can be configured to operate during certain periods of time when the most economical energy consumption tariff is in effect. So, for example, at night the system will conserve a certain volume which can be used for any needs during the next day.

Where is it undesirable to use heat accumulators?

The nature of the operation of buffer batteries is designed to ensure uniform heat transfer and smooth out surges during temperature changes. But this principle of operation is not always useful. For heating systems, which, on the contrary, require an accelerated increase or decrease in temperature, such an addition will be unnecessary. In such situations, increasing the potential of the coolant due to auxiliary ones will prevent rapid cooling and heating. In addition, it is worth noting that home heat accumulators for the most part make precise temperature control impossible. It would seem that such a solution could be optimal for heating systems operating in short intervals - it is enough to heat the container in advance and then use the ready energy at the appointed time. However, maintaining the optimal state of the coolant itself requires the consumption of certain energy. Therefore, for example, a boiler room used for irregular and short-term heating of a dryer can easily do without a battery. It’s a different matter if we are talking about a whole group of boilers that can be combined into one system using a buffer.

Battery characteristics

Among the main characteristics are the dimensional parameters of the unit, its capacity, maximum temperature and pressure indicator. For private homes, manufacturers offer small installations, the diameter of which can be 500-700 mm, and the height - about 1500 mm. It is also important to consider weight, since in some cases specialists have to use concrete screeds to give the structure stability. The average heat accumulator weighs about 70 kg, although exact value directly related to the capacity and quality of the tank insulation. Performance characteristics come down to temperature and pressure. The first value is about 100 °C and the pressure level can reach 3 Bar.

Battery connection

A homeowner with knowledge in electrical engineering can not only independently connect a ready-made buffer to the heating system, but also completely assemble the structure. First you need to order a container in the form of a cylinder, which will become a working buffer. Next, in transit through the entire tank, it is necessary to conduct a return pipeline through the niche of the future heat accumulator. The connection should begin with the connection between the boiler return and the tank. From one component to the second, a place should be provided where the circulation pump will be installed. With its help, the hot coolant will move from the barrel to the shut-off valve and expansion tank.

You need to install the heat accumulator with your own hands in such a way that the most rational distribution of liquid throughout all rooms is assumed. To assess the quality of work assembled system You can provide it with thermometers and pressure sensors. Such equipment will allow you to evaluate how efficiently the battery will function through the connected circuits.

Water systems

A classic heat accumulator involves the use of water as an energy carrier. Another thing is that this resource can be used in different ways. For example, it is used to supply heated floors - the liquid passes through circulation pipes into a special coating. Water can also be used to ensure the operation of the shower and other needs, including technological, hygienic and sanitary purposes. It is worth noting that the interaction of boilers with water is quite common due to its low cost. Water heat storage is cheaper compared to electric heaters. On the other hand, they also have their drawbacks. As a rule, they come down to nuances in the organization of circulation networks. The greater the volume of resource consumed, the more expensive its organization is. Installation costs are one-time, but operation will be cheaper.

Solar systems

In water systems, the design includes a comb heat exchanger designed for a geothermal pump. But a solar collector can also be used. In essence, this creates a power plant center that optimizes the function of the heating plant by reserving energy from different sources. Although solar thermal storage is less common, it can be used in typical heating systems. Solar collectors They also retain energy potential, which is later spent on household needs. But it is important to consider that hot coolant in the form of water itself requires less energy than solar battery. The best option The use of such batteries is the direct integration of panels into places where heating should be carried out without additional transformations.

How to choose heat?

It is worth starting from several parameters. To begin with, the functionality of the system and its performance indicators are determined. The tank must completely cover the volumes that are planned to be consumed during operation of the heating system. You shouldn’t skimp on control systems either. Modern relays with automatic regulators not only make programming convenient engineering systems, but also provide protective properties. A properly equipped heat accumulator has protection against idle move and provides ample opportunities to indicate temperature conditions.