Water heating with heat accumulator. Heating by heat accumulator at night electricity tariff. How does a hollow aggregate work?

Inability to use relatively inexpensive energy as a source of energy for heating housing natural gas forces home owners to look for other acceptable solutions. So, in regions where there are no special problems with the procurement or purchase of firewood, solid fuel boilers come to the rescue. It also happens that the only alternative becomes Electric Energy. In addition, new technologies are increasingly being used to direct the energy of solar radiation to heating needs.

All these approaches are not without significant shortcomings. Thus, these include unevenness and pronounced periodicity in the supply of thermal energy. In the case of an electric boiler, the main negative factor will be high price consumed energy. It is obvious that the inclusion in the general scheme of a special device that would accumulate currently unclaimed thermal energy and release it as needed would help to significantly increase the efficiency of the heating system, improve the efficiency and uniformity of its operation, and simplify operational operations as much as possible. This is exactly the function that a heat accumulator performs for.

The main purpose of the heating system heat accumulator

• The simplest heating system with a solid fuel boiler has a pronounced cyclical operation. After loading firewood and igniting it, the boiler gradually reaches maximum power, actively transferring thermal energy to the heating circuits. But as the load burns out, the heat transfer begins to gradually decrease, and the coolant distributed through the radiators cools down.

The operation of a conventional solid fuel boiler is characterized by a pronounced alternation of peaks and “troughs” in the production of thermal energy

It turns out that during the period of peak heat production it may remain unclaimed, since a customized heating system equipped with thermostatic control will not take in excess. But during the period when the fuel burns out and, moreover, when the boiler is idle, there will be a clear lack of thermal energy. As a result, part of the fuel potential is simply wasted, but at the same time, the owners have to load firewood quite often.

To a certain extent, the severity of this problem can be reduced by installing a boiler long burning, but it’s impossible to completely remove it. The discrepancy between the peaks of heat production and its consumption can remain quite significant.

• In the case of an electric boiler, the high cost of energy consumption comes to the fore, which forces owners to think about maximizing the use of equipment during periods of preferential night tariffs and minimizing consumption during the daytime.

Benefits of using differentiated electricity tariffs

With a competent approach to electricity consumption, preferential tariffs can bring very tangible savings funds. This is described in detail in a special publication on the portal dedicated to.

An obvious solution arises - to accumulate thermal energy at night in order to achieve its minimum consumption during the day.

• The periodicity of thermal energy generation is even more pronounced in the case of using solar collectors. Here there is a dependence not only on the time of day (at night the intake is generally zero).

Heating peaks on a bright sunny day or in cloudy weather cannot be compared. It is clear that it is impossible to directly make your heating system dependent on the current “whims” of nature, but you also don’t want to neglect such a powerful additional source of energy. Obviously some kind of buffer device is required.

These three examples, with all their diversity, are united by one common circumstance - a clear discrepancy between the peaks of thermal energy production and its rational, uniform use for heating needs. To eliminate this imbalance it serves special device, called a heat accumulator (thermal storage, buffer tank).

Prices for heat accumulators Hajdu

heat accumulator Hajdu

The principle of its operation is based on the high heat capacity of water. If a significant volume of it is heated to the required level during the period of peak thermal energy supply, then for a certain period this accumulated energy potential can be used for heating needs. For example, if we compare thermophysical indicators, just one liter of water, when cooled by 1°C, can warm up a cubic meter of air by as much as 4°C.

The heat accumulator is always a volumetric reservoir with effective external thermal insulation, connected to the heat source circuit(s) and heating circuits. The simplest scheme It's better to look at an example:

The simplest heat accumulator (TA) in design is a vertically located volumetric tank, into which four pipes are embedded on two opposite sides. On the one hand, it is connected to the circuit (KTT), and on the other, to the heating circuit distributed throughout the house.

After loading and igniting the boiler, the circulation pump (Nk) of this circuit begins to pump coolant (water) through the heat exchanger. Cooled water enters the boiler from the lower part of the TA, and heated water arrives into the upper part. Due to the significant difference in the density of the cooled and hot water there will be no active mixing of it in the tank - during the combustion of the fuel fill, the TA will gradually be filled with hot coolant. As a result, if the parameters are correctly calculated, after the stored fuel has completely burned out, the container will be filled with hot water, heated to the calculated level. All potential energy fuel (minus, of course, the inevitable losses reflected in the boiler efficiency) is converted into heat, which is accumulated in the heat exchanger. High-quality thermal insulation allows you to maintain the temperature in the tank for many hours, and sometimes even days.

Stage two – the boiler is not working, but the heating system is functioning. Using your own circulation pump The heating circuit pumps coolant through pipes and radiators. The intake is made from above, from the “hot” zone. Intensive independent mixing is again not observed - for the reason already mentioned, and hot water enters the supply pipe, cooled water returns from below, and the tank gradually releases its heat in the direction from bottom to top.

In practice, during the heating process of the boiler, the selection of coolant into the heating system, as a rule, does not stop, and the heating system will only accumulate excess energy, which currently remains unclaimed. But with the correct calculation of the parameters of the buffer tank, not a single kilowatt of thermal energy should be wasted, and by the end of the boiler firing cycle, the TA should be “charged” to the maximum extent.

It is clear that the cyclical operation of such a system with an installed electric boiler will be tied to preferential night rates. The control unit's timer will turn the power on and off at a set time in the evening and morning, and during the day the heating circuits will be powered only (or predominantly) from the heat accumulator.

Design features and basic connection diagrams for various heat accumulators

So, a heat accumulator is always a volumetric vertical cylindrical tank, which has highly effective thermal insulation and is equipped with pipes for connecting heat generation and consumption circuits. But the internal design may vary. Let's consider the main types of existing models.

Main types of heat accumulator designs

1 – The simplest type of TA design. This implies a direct connection of both heat sources and consumption circuits. Such buffer tanks are used in the following cases:

• If the boiler and all heating circuits use the same coolant.
• If the maximum permissible coolant pressure in the heating circuits does not exceed that of the boiler and the heating unit itself.

In cases where the requirement cannot be met, the heating circuits can be connected through additional external heat exchangers

• If the temperature in the supply pipe at the outlet of their boiler does not exceed permissible temperature in heating circuits.

However, this requirement can also be bypassed when installing mixing units with three-way valves on circuits that require a lower temperature difference.

2 – The heat accumulator is equipped with an internal heat exchanger located in the lower part of the tank. The heat exchanger is usually a spiral made of steel stainless pipe, regular or corrugated. There may be several such heat exchangers.

This type of TA is used in the following cases:

• If the pressure and achieved temperature of the coolant in the heat source circuit significantly exceed valid values for consumption circuits and for the buffer tank itself.
• If there is a need to connect several heat sources (according to the bivalent principle). For example, a solar system (solar collector) or a geothermal heat pump comes to the aid of the boiler. Moreover, the lower the temperature pressure of the heat source, the lower its heat exchanger should be placed in the heat exchanger.
• If the heat source and consumption circuits use different type coolant.

Unlike the first scheme, this heat exchanger is characterized by active mixing of the coolant in the container - heating occurs in its lower part, and less dense hot water tends upward.

The diagram in the center of the HA shows a magnesium anode. Due to the lower electrical potential, it “pulls” ions of heavy salts onto itself, preventing scale build-up internal walls tank. Subject to periodic replacement.

3 – The heat accumulator is supplemented with a flow-through hot water supply circuit. Cold water enters from below, and supply to the hot water tap point, respectively, from below. Most of the heat exchanger is located in the upper part of the heat exchanger.

This scheme is considered optimal for conditions where hot water consumption is sufficiently stable and uniform, without pronounced peak loads. Naturally, the heat exchanger must be made of metal that meets food water consumption standards.

The rest of the scheme is similar to the first one, with direct connection of heat generation and consumption circuits.

4 – Inside the heat accumulator there is a tank to create a supply of hot water for domestic consumption. In fact, this scheme resembles a built-in boiler indirect heating.

The use of such a design is fully justified in cases where the peak of thermal energy production by the boiler does not coincide with the peak of hot water consumption. In other words, when the current household structure in the house involves massive, but rather short-term consumption of hot water.

All of the above schemes can vary in various combinations - the choice of a specific model depends on the complexity created system heating, quantity and type of body sources and consumption circuits. Please note that most heat accumulators have many outlet pipes spaced vertically.

The fact is that with any scheme, a temperature gradient (difference in temperature pressure in height) is formed one way or another inside the buffer tank. It becomes possible to connect heating system circuits that require different temperature conditions. This greatly facilitates the final thermostatic control of heat exchange devices (radiators or underfloor heating), with minimal unnecessary energy losses and reduced load on the control devices.

Typical connection diagrams for heat accumulators

Now we can consider the basic schemes for installing heat accumulators in a heating system.

Illustration	Brief description of the scheme
	The temperature and pressure are the same in the boiler and in the heating circuits. The coolant requirements are the same. A constant temperature is maintained at the boiler outlet and in the heat exchanger. On heat exchange devices, adjustment is limited only to a quantitative change in the coolant passing through them.
	The connection in the heat accumulator itself, in principle, repeats the first diagram, but the adjustment of the operating modes of the heat exchange devices is carried out according to a qualitative principle - with a change in the temperature of the coolant. For this purpose, thermostatic mixing units, for example, three-way valves, are included in the circuit. This scheme allows the most rational use of the potential accumulated by the heat accumulator, that is, its “charge” will last for a longer time.
	This scheme, with coolant circulation in a small boiler circuit through a built-in heat exchanger, is used when the pressure in this circuit exceeds the permissible limit in heating devices or in the buffer tank itself. The second option is that different coolants are used in the boiler and in the heating circuits.
	The initial conditions are similar to scheme No. 3, but an external heat exchanger is used. Possible reasons for this approach: - the heat exchange area of ​​the built-in “coil” is not enough to maintain the required temperature in the body accumulator. – previously a heat exchanger had already been purchased without an internal heat exchanger, and the modernization of the heating system required exactly this approach.
	Scheme with the organization of flowing hot water through a built-in spiral heat exchanger. Designed for uniform consumption of hot water, without peak loads.
	This scheme, using a heat accumulator with a built-in tank, is designed for peak hot water consumption, but not highly positive. After using up the created reserve and, accordingly, filling the container cold water, heating to the required temperature may take quite a long time.
	A bivalent circuit that allows you to use an additional source of thermal energy in the heating system. In this case, the option with connecting a solar collector is shown in a simplified manner. This circuit is connected to the heat exchanger at the bottom of the heat accumulator. Typically, such a system is designed in such a way that the main source is the solar collector, and the boiler is turned on as needed, for reheating, when there is insufficient energy from the main one. The solar collector, of course, is not a dogma - there may be a second boiler in its place.
	A scheme that can be called multivalent. In this case, the use of three sources of thermal energy is shown. The role of the high-temperature boiler is played by the boiler, which, again, can only play a supporting role in general scheme heating Solar collector - similar to the previous diagram. In addition, another low-temperature source is used, which, at the same time, is stable and independent of the weather and time of day - a geothermal heat pump. The lower the temperature pressure from the connected energy source, the lower the location of its connection to the heat accumulator.

Of course, the diagrams are given in a very simplified form. But in fact, connecting a heat accumulator to complex, branched systems, with different heating circuits, and even receiving heating from sources of different power and temperature, requires highly professional design with engineering thermotechnical calculations, using many additional adjustment devices.

One example is shown in the figure:

1 – solid fuel boiler.

2 – electric boiler, which turns on only as needed and only during the period of validity of the preferential tariff.

3 – special mixing unit in the high-temperature boiler circuit.

4 – solar station, solar collector, which on fine days can act as the main source of thermal energy.

5 – heat accumulator, to which all heat generation and consumption circuits converge.

6 – high-temperature heating circuit with radiators, with adjustment of modes according to the quantitative principle - only using shut-off valves.

7 – low-temperature heating circuit – “warm floor”, which necessarily provides for high-quality regulation of the heating temperature of the coolant.

8 – flow-through hot water supply circuit, equipped with its own mixing unit for high-quality regulation of the temperature of domestic hot water.

In addition to all of the above, the heat accumulator can have its own built-in electric heaters- Heating elements. Sometimes it is beneficial to maintain a given temperature with their help without, for example, once again resorting to unscheduled lighting of a solid fuel boiler.

Special additional heating elements can be purchased separately - their mounting thread is usually adapted to the connection sockets available on many models of heat accumulators. Naturally, connecting electrical heating will require the installation of an additional thermostatic unit, which will ensure that the heating elements are turned on only when the temperature in the heater drops below user installed level. Some heaters are already equipped with a built-in type of this type.

Prices for S-Tank heat accumulators

Thermal accumulator S-Tank

Video: Recommendations from a specialist for creating a heating system with a solid fuel boiler and heat accumulator

What to consider when choosing a heat accumulator

Of course, it is recommended to select a heat accumulator at the stage of designing a home heating system, guided by the calculation data of specialists. However, circumstances vary, and it is still necessary to know the basic criteria for evaluating such a device.

• The capacity of this buffer tank will always come first. This value is calculated in accordance with the parameters of the system being created, the power of the boiler, the required amount of energy for heating needs, and hot water supply. In a word, the container must be such as to ensure the accumulation of all currently excess heat, preventing its loss. Some rules for calculating capacity will be discussed below.
• Naturally, the dimensions of the product and its weight directly depend on the capacity. These parameters are also decisive - it is not always possible and not everywhere to place a heat accumulator of the required volume in a dedicated room, so the issue must be thought through in advance. It happens that large volume tanks (over 500 liters) do not fit through standard doorways (800 mm). When estimating the mass of TA, it must be taken into account together in the entire volume of water of a completely filled device.
• The next parameter is the maximum permissible pressure in the heating system being created or already functioning. A similar TA indicator should be, in any case, no lower. This will depend on the thickness of the walls, the type of material used, and even the shape of the container. Thus, in buffer tanks designed for pressures above 4 atmospheres (bar), the upper and lower lids usually have a spherical (toroidal) configuration.

• Material for making the container. Carbon steel tanks with anti-corrosion coating are cheaper. Stainless steel containers are certainly more expensive, but also guarantee period their exploitation is also significantly higher.
• Availability of additional built-in heat exchangers for heating or hot water supply circuits. Their purpose has already been mentioned above - models are selected depending on the overall complexity of the heating system.
• Availability additional options– the possibility of installing heating elements, installing control and measuring instruments, safety devices - safety valves, air vents, etc.
• The thickness and quality of the external thermal insulation of the TA body must be assessed so that you do not have to deal with this issue yourself. The better the tank is insulated, the longer the “thermal charge” will naturally be stored in it.

Features of installation of heat accumulators

Installation thermal battery implies compliance with certain rules:

• All connected circuits must be connected with threaded couplings or flanges. Welded joints are not allowed.
• The connected pipes must not exert any static load on the TA pipes.
• It is recommended to install shut-off valves on all pipes connected to the TA.
• Visual temperature monitoring devices (thermometers) are installed at all used inputs and outputs.
• There should be a drain valve at the lowest point of the TA or on the pipe in close proximity to it.
• Filters for mechanical water purification – “mud collectors” – are installed on all pipes entering the heat accumulator.
• Many models have a pipe on top for connecting an automatic air vent. If there is none, then the air vent must be installed on the uppermost outlet pipe.
• A pressure gauge and a safety valve are to be installed in the immediate vicinity of the heat accumulator.
• Making any independent changes to the design of the heat accumulator that are not specified by the manufacturer is strictly prohibited.
• Installation of TA should be carried out only in a heated room, eliminating the possibility of freezing of the liquid.
• A tank filled with water can have a very significant mass. The platform must be able to withstand such a high load. Often for these purposes it is necessary to add a special foundation.
• No matter how the heat accumulator is installed, free access to the inspection hatch must be ensured.

Carrying out simple calculations of heat accumulator parameters

As mentioned above, a comprehensive calculation of a heating system with several circuits for the production and consumption of thermal energy is a task only feasible for specialists, since many diverse factors have to be taken into account. But certain calculations can be carried out on your own.

For example, the house is installed. Its power generated at full fuel load is known. The combustion time of a full load of firewood was determined experimentally. You are planning to purchase a heat accumulator, and you need to determine how much volume is required to ensure that all the heat generated by the boiler is effectively used.

Let's take the well-known formula as a basis:

W = m × c × Δt

W- the amount of heat required to heat a mass of liquid ( m) with a known heat capacity ( With) by a certain number of degrees ( Δt).

From here it is easy to calculate the mass:

m = W / (s × Δt)

It wouldn’t hurt to take into account the boiler efficiency ( k), since energy losses are inevitable one way or another.

W = k× m × c × Δt, or

m = W / (k × c × Δt)

Now let's look at each of the values:

• m – the desired mass of water, from which, knowing the density, it will be easy to determine the volume. It would not be a big mistake to calculate from the calculation 1000 kg = 1 m³.
• W– excess amount of heat generated during the boiler firing period.

It can be defined as the difference in the energy values ​​generated during the combustion of the fuel deposit and spent during the same period on heating the house.

The maximum boiler power is usually known - this is the nameplate value designed for optimal waters solid fuel. It shows the amount of thermal energy generated by the boiler per unit of time, for example, 20 kW.

Any owner always knows quite accurately how long it takes for his fuel fill to burn out. Let's say it will be 2.5 hours.

Next, you need to know how much energy can be spent heating the house at this time. In a word, it is necessary to determine the thermal energy needs of a particular building to ensure comfortable living conditions.

Such a calculation, if the value of the required power is unknown, can be done independently - for this there is a convenient algorithm given in a special publication on our portal.

How to independently carry out thermal calculations for your own home?

Information about the amount of thermal energy required to heat a house is often in demand - when choosing equipment, arranging radiators, and when carrying out insulation work. With a calculation algorithm including convenient calculator, the reader can get acquainted by opening the publication dedicated to the link.

For example, heating a house requires 8.5 kW of energy per hour. This means that in 2.5 hours of combustion of the fuel filler the following will be obtained:

20 × 2.5 = 50 kW

During the same period the following will be spent:

8.5 × 2.5 = 21.5 kW

W = 50 – 21.5 = 28.5 kW

• k– Boiler room efficiency installations. Usually indicated in the product passport as a percentage (for example, 80%) or decimal (0,8).
• With– heat capacity of water. This is a tabular value that is equal to 4.19 kJ/kg×°C or 1.164 Wh/kg×°C or 1.16 kW/m³×°C.
• Δt– the temperature difference by which the water must be heated. You can define it for your system empirically, measuring the values ​​on the supply and return pipes when the system is operating at maximum power.

Let's assume that this value is

Δt = 85 – 60 = 35 °C

So, all the values ​​are known, and all that remains is to substitute them into the formula:

m = 28500 / (0.8 × 1.164 × 35) = 874.45 kg.

The same approach can be applied if the volume of a heat accumulator connected to is calculated. The only difference is that for the calculation it is not the combustion time that is taken, but the time interval of the preferential tariff, for example, from 23.00 to 6.00 = 7 hours. To “unify” this value, it can be called, for example, “boiler activity period.”

To simplify the task for the reader, below is a special calculator that will allow you to quickly calculate the recommended volume of a heat accumulator for an existing (planned for installation) boiler.

A heat accumulator is a device capable of accumulating thermal energy from a heat source when it is excessively produced, and then using its reserve if necessary.

The heat source can be a heating boiler, furnace, solar collector, etc.

Essentially, any massive body that has a temperature greater than absolute zero has a reserve of thermal energy. In this case, the reserve of accumulated heat depends on the degree of heating and body weight.

For example, any building made of brick, stone or concrete blocks (materials capable of storing heat) is a heat accumulator, the continuous operation of which few people pay attention to. But it is precisely thanks to the reserve of heat accumulated by the walls of the house that it is cool on a hot day and warm at night when the outside air temperature drops, the natural ventilation system works, and there are no sudden temperature jumps during a short-term shutdown of heating or during ventilation.

Another example of a heat accumulator is a Russian stove or any other heating stove made of stone or brick. When burning wood, the stove mass accumulates thermal energy, and then, when cooled, releases it into the surrounding space.

The greater the weight of the stove, the greater the heat reserve it has and the longer it can maintain comfortable temperature in room. It is for this reason that the traditional Russian stove is made massive, weighing up to one and a half tons or more, and it is heated periodically: once a day.

Traditionally, stones or baked bricks were used to accumulate heat, but their use is only justified for stove heating, the use of which in simple modern houses is not always convenient. For heating modern home More often they use heating boilers rather than stoves.

Which boilers require a heat accumulator?

A heat accumulator is needed only for boilers that operate periodically: coal or wood. Boilers that operate uninterruptedly (gas or electric), equipped with continuous fuel supply systems, long-burning boilers do not require heat accumulation.

Solid fuel traditional boilers require periodic loading of firewood, time complete combustion fuel in them for no more than 3 hours. At the end of the combustion process, the coolant in the heating system will not only cool down to the air temperature in the room, but also in places where the pipeline is laid at the boundary (on the floor, in the basement, in the attic) it may freeze, forming ice plugs in the heating system that block water circulation.

In these conditions we're talking about It’s no longer about comfortable conditions in the house, but about the integrity and safety of the heating system. The main task of heat accumulation in systems with a solid fuel heating boiler is to create a reserve of thermal energy, the use of which during the period of inactivity of the boiler will help to avoid a sharp drop in temperature in the room and to avoid freezing of the coolant.

Thermal accumulator device

A heat accumulator for a heating boiler should be convenient not only for storing heat, but also for its further use. The only substance suitable for solving the problem is the coolant. This can be water or antifreeze placed in a large container included in the heating system.

To preserve heat, the container is additionally insulated: lined with mineral wool, foil, thermal insulation panels, and installed on an insulated base.

The volume of the heat accumulator is chosen according to the principle, the larger the better, but usually we are talking about a capacity of 2-5 m3. Another important addition: the tank must be sealed, with two holes: for connecting the pipeline.

The heat accumulator is connected to the heating system parallel to the boiler according to the principle of a heating device with connections to both the supply and return. Shut-off valves must be installed at the supply, allowing you to change the direction of movement of the coolant, allowing it either only to the heating devices, or only to the heat accumulator, or at the same time both there and there. As a rule, this is a three-way valve.

How does a heat accumulator work in a heating system?

When wood burns intensively in a solid fuel boiler, maximum heat is generated, which allows heating not only the radiators in the house, but also the water supply in the battery. After the firewood burns out, the heat from the boiler stops flowing, but the coolant circulation in the system continues: cold water rolls down, and hotter coolant from the battery enters the system.

Return water, returning to the heating boiler, also passes through the battery. If the return temperature is higher than the temperature of the water in the container, then the liquid inside is additionally heated due to the return flow. If the return is cold, then, on the contrary, it is heated before entering the boiler, which reduces the temperature difference between the hot boiler and cold return water.

The larger the battery capacity, the longer the system can operate without “recharging”.

Practical use

A heat accumulator in a heating system with a solid fuel boiler can easily be called a real godsend for its owners. It is this simple device that allows you to leave the house for several hours even in severe frosts without fear for its safety. heating system, sleep peacefully at night, without jumping up to the boiler to add a new portion of firewood and without fear of the boiler being destroyed when too cold coolant enters it.

To control the operation of a heating system with a heat accumulator, a three-way valve is used.

With its help, you can open the movement of hot coolant only to heating devices, which is usually done when you want to quickly warm up a room. If the house is already hot, but the boiler continues to work, you can turn off the water supply to the radiators and direct it only to the heat accumulator.

To simultaneously heat the heating devices and the heat accumulator, an intermediate position of the tap is selected.

Heat accumulator and circulation pump

Usually, solid fuel boilers used in gravity heating systems. In this case, the heat accumulator operates due to natural convection: cold coolant flows into it through the lower pipe, and a more heated liquid rushes upward, flowing to the heating devices.

In systems with a circulation pump, the heat accumulator works the same way, but here the speed of movement of the coolant is set by the pump, which undoubtedly has a positive effect on the operation of the entire heating system.

About the advantages and disadvantages

Installing a heat accumulator makes the operation of the heating system stable, eliminating sudden changes in temperature not only in the house, but also in the flow of coolant into the boiler.

The only drawback of a heat accumulator is its size: a small capacity does not allow heat to be accumulated and used, and for a large-volume reservoir it is not always possible to find enough space. And to install the container, you will have to strengthen the foundation or place it in the basement.

Heat accumulator for heating boilers
Why do you need a heat accumulator for heating boilers? How is it designed and works? Practical application of a heat accumulator

Heat accumulator for boiler

When designing a heating system, the main goals are comfort and reliability. The house should be warm and cozy, and for this, hot coolant should always flow into the radiators without delays or temperature surges.

This is difficult to achieve with a solid fuel boiler, because it is not always possible to fill a new portion of firewood or coal on time, and the combustion process itself is uneven. A heat accumulator for heating boilers will help correct the situation.

With a simple design and operating principle, it can eliminate a number of inconveniences and disadvantages of the classical heating scheme.

Why is it needed?

The heat accumulator is a well-insulated large-capacity tank filled with coolant and water. Due to the high heat capacity of water, when heating the entire volume in the container, it accumulates significant reserve thermal power that can be used for its intended purpose at a time when the boiler cannot cope or is completely inactive.

The heat accumulator actually increases the volume of coolant in the heating circuit, the heat capacity and, accordingly, the inertia of the entire system. Heating the entire volume will require more energy and time with limited heating power, but the battery will also take a very long time to cool down. If necessary, hot water from the battery can be supplied to the heating circuit and maintain a comfortable temperature in the house.

To evaluate the benefits of a heat accumulator, it is easiest to consider several situations first:

• A solid fuel boiler only periodically heats the water. At the moment of ignition, the power is minimal, during active combustion the power increases to a maximum, after the bookmark burns out, it drops again and so the cycle repeats. As a result, the water temperature in the circuit constantly fluctuates over a fairly large range,
• To obtain hot water, it is necessary to install an additional heat exchanger or an external boiler with indirect heating, which significantly affects the operation of the heating circuit,
• It is extremely difficult to connect additional heat sources to a heating system built around a solid fuel boiler. A complex decoupling will be required, preferably with automatic control,
• A solid fuel boiler, even one that burns for a long time, constantly requires the user’s attention. Once you skip the time for adding a new portion of fuel, the coolant in the heating circuit is already starting to cool down, like the whole house,
• Often the maximum boiler power is excessive, especially in spring and summer, when maximum output is not required.

The solution for all of the above situations is a heat accumulator, and an uncompromising one at that. and the most affordable in terms of implementation and cost. It acts as a decoupling point between the solid fuel boiler and the heating circuit(s) and an excellent base platform for enabling additional functions.

By design, the heat accumulator can be:

• “empty” - a simple insulated container with a direct connection,
• with a coil or pipe register as a heat exchanger,
• with built-in boiler tank.

With a full body kit, the heat accumulator is capable of:

• Accumulate and store a significant amount of thermal energy, primarily excess, with its subsequent release into the heating circuit. Even if you miss one or two refills of firewood and the boiler stops, the temperature in the house will only drop a couple of degrees. For electric boilers, it is possible to set a schedule according to which electricity will be wasted only at night at a reduced rate, while during the day heat will be supplied from the heat accumulator,
• If there is a lower heat exchanger, connect additional heat sources, a solar collector, a spare boiler running on gas or diesel fuel, a geothermal heat pump,
• With built-in heating elements, used as a backup heat source in case the solid fuel boiler does not work or is turned off for maintenance and repair,
• If there is an upper heat exchanger - for connecting a DHW circuit or an indirect heating boiler. Some models of heat accumulators, instead of a heat exchanger, are equipped with a ready-made boiler located inside the main tank,
• Implement additional protection in systems with forced circulation in case of a power outage, preventing overheating of the water in the boiler. Considering the tank as a hydraulic isolation unit, it can be connected in a mixed circuit with the boiler, above it and pipes of larger diameter to maintain natural circulation. At the same time, distribution to the radiators will be carried out by a pump forcibly.

The power accumulated by a heat accumulator (TA) is calculated based on the volume of the container, more precisely the mass of the liquid in it, the specific heat capacity of the liquid used to fill it, and the temperature difference, the maximum to which the liquid can be heated, and the minimum target at which it can still be carried out. heat intake from the heat accumulator to the heating circuit.

• Q = m*C*(T2-T1),
• m – mass, kg,
• C – specific heat capacity W/kg*K,
• (T2-T1) – temperature delta, final and initial.

If the water in the boiler and, accordingly, in the heating element is heated to 90ºС, and the lower threshold is taken equal to 50ºС, then the delta is equal to 40ºС. If we take TA water as filling, then one ton of water, when cooled to 40ºC, releases approximately 46 kW*hours of heat.

Heat accumulator for boiler
In the article you can read what a heat accumulator for a boiler is and how to choose one. Heat accumulator connection diagram and manufacturers.

Heat accumulator, its structure and principle of operation.

Good day everyone! If you have come to this page of my blog, then you are interested in at least 2 questions:

• What is a heat accumulator?
• How does a heat accumulator work?

I'll start answering these questions in order.

What is a heat accumulator?

To answer this question we need to give a definition. It sounds like this: a heat accumulator is a container in which a large volume of hot coolant accumulates. The outside of the container is covered with thermal insulation from mineral wool or foamed polyethylene.

Why do you need a heat accumulator?

You ask: “Why do we need this oversized thermos?” Everything is very simple here; it allows you to optimally use the heat given off by the boiler. A powerful boiler (most often solid fuel) always works in conjunction with a heat accumulator. The boiler quickly and non-stop transfers heat from the burned fuel to the heat accumulator, and it, in turn, slowly and desired mode releases this heat to the heating system. The system volume is much smaller than the battery capacity. This allows you to “stretch” the heat from the fuel over time. It turns out to be essentially a long-burning boiler. When the battery capacity is heated, the boiler constantly operates at full power, and this avoids the appearance of tarry condensate in the chimney and boiler.

How does a heat accumulator work?

As mentioned above, TA is a container in which hot water (or other coolant) accumulates. To make everything clearer, look at the following figure:

The container has several pipes for connecting various equipment:

• Thermal energy generator - boiler, solar collector, heat pump.
• Plate heat exchanger for heating hot water.
• Various boiler equipment - safety group, expansion tank and so on.

Materials of water-containing container.

Heat accumulator connection diagram.

Now let's look at how the battery is included in the heating system:

From this diagram it can be seen that the TA is included in the heating system as a hydraulic separator (hydraulic arrow). I recommend reading a separate article dedicated to this useful device. Let me say briefly that this switching scheme eliminates the mutual influence of different circulation pumps and allows the boiler to be provided with the required volume of coolant, which has a positive effect on the life of the heat exchanger.

Thermal storage and hot water supply.

Another important issue is the installation of hot water supply in the house. This is where TA can also come to the rescue. Of course, you cannot use water directly from the heating system for sanitary needs. But there are at least two solutions:

• Connecting a plate heat exchanger to the TA, in which sanitary water will be heated, is used on the simplest TA models.
• Buying a heat accumulator with built-in DHW system- it can be implemented either using a separate heat exchanger (coil), or according to the “tank in tank” scheme.

You can, of course, also purchase an indirect heating boiler separately, but I believe that this can only be done if you have the necessary space in your boiler room.

A heat accumulator is another way to increase the time between adding fuel to the boiler. In addition, TA can be used in systems with solar collectors and heat pumps. Most often, TA is used as a replacement for long-burning boilers. The alternative is certainly interesting and worthy of your attention. This concludes my story. I look forward to your questions in the comments.

Thermal accumulator, its structure and principle of operation
Heat accumulator, its structure and principle of operation. What is a heat accumulator? Why do you need a heat accumulator? Materials of the water-containing tank of the heat accumulator. Thermal storage and hot water supply.

Solid fuel boilers are used to heat suburban properties if other types of fuel are unavailable or unreasonably expensive. To everyone heating season the owner of the cottage has to prepare the necessary supply of firewood and coal, the volume of which depends on the area of ​​the property and the quality of its thermal insulation, as well as the severity of climatic conditions in the region of residence. Most models of solid fuel boilers can provide a comfortable temperature in the house if they are heated twice a day at a strictly defined time. If you shift the time of ignition of fuel in the combustion chamber of the unit, then it becomes cold in the living room. The exception is long-burning boilers, which can maintain the required temperature in the house for several days. You can achieve the same result from a conventional solid fuel boiler if you include an additional unit in the heating system that can accumulate excess heat generated by the unit when burning a portion of fuel. Such units include buffer tanks or heat accumulators, which are also called storage tanks.

Installing a heat accumulator allows you to:

• organize boiler maintenance at a convenient time of day,
• increase the time between successive fuel loads without reducing the comfort of living in the house,
• optimize home maintenance costs by reducing purchases of solid fuel.

The use of solid fuel boilers together with buffer tanks allows you to reduce the consumption of solid fuel by several times, while ensuring the required level of comfort in the house. The efficiency of installing a storage tank can be significantly increased if you use intelligent controllers and sensors in the heating system. When the specified temperature values ​​are reached in the premises of the house, the coolant is supplied to heating devices stops.

The heat generated by the boiler, which continues to operate, is accumulated in a buffer tank, and then transferred to the cooled coolant, which begins to circulate through the system, bypassing the burnt-out boiler. The larger the volume of the buffer tank, the longer the house will be heated due to the thermal energy accumulated in it.

Advantages of using a thermal storage tank in the heating system of a country house connected to several heat generators

Heat accumulator for heating boilers: device, types, connection principles
Installation of a heat accumulator is necessary to increase the performance of a solid fuel boiler and reduce fuel consumption.

A heat accumulator is a unit for collecting and increasing heat for the purpose of its further use. The device is used in private homes, apartments, enterprises, and also for pre-heating engines. A heat accumulator for a heating system allows you to reduce energy costs for heating rooms 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 a heating system is somewhat cyclical. First, fuel is put into it, ignited, and then the boiler gradually reaches maximum power and transfers thermal energy through the coolant to the heating system.

The stack of firewood gradually burns out, heat transfer decreases, and the coolant cools down. During the period of 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, solid fuel must be added again.

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

Connecting a solid fuel boiler with a heat accumulator

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

For example, when water cools by 1° C, it can heat 1 m³ of air by 4° C. The simplest heat accumulator for heating boilers is a vertical container with four pipes cut into different directions. There are heat accumulators with a variety of storage materials:

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

IN bottom part The storage tank receives cold coolant, and the upper one receives hot fluid. Due to the significant difference in density, the water will not mix, and the hot coolant will gradually fill the entire container.

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

Thermal insulation allows you to maintain high water temperatures for a long time. When the boiler stops working, the heating system continues to function. Thanks to the pump, hot water from the battery flows into the pipelines and heating devices of the house.

In place of the hot coolant, cooled water again flows into the buffer tank through the lower pipe from the return line of the pipeline. When using an electric boiler, a heating circuit with a heat accumulator can be used at night, when a preferential tariff applies.

Diagrams of boiler rooms with a heat accumulator

All storage devices 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 easy to identify by the numerous pipes coming out of the tank.

Thermal accumulator or buffer tank. And why is it needed? Storage tank or buffer capacity principle

This is exactly the kind of heating in our houses - we wouldn’t install anything bad for ourselves.

My team and I installed the same heating system in more than 60 houses.

Send a request

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Thermal accumulator and night electricity tariff are the most profitable and cheapest system after mains gas.

All other heating options are wood pallets, wood boilers, diesel fuel - in any case they turn out to be more expensive. And you need to bother with them, constantly making sure that there is firewood or gas.

Here is a diagram of my heating system.

rice. storage tank in the heating system

What we have?

From the heat accumulator through the heat head (the temperature can be adjusted), the coolant is supplied to the floors. Here I also have a coil wound, which removes heat from the heat accumulator, and from it, from the coil, the coolant goes to the floors.

Accordingly, my heat accumulator is heated due to heating elements, i.e. electricity. And plus, if there is not enough heat, I also connect a wood-burning boiler (but over 4 winters I fired it at most 10 times, and then purely for the sake of maintaining its functionality, I ran the pumps, cleaned the chimney with fire, etc.)

As for main gas, why don’t I use it?

I have two pipes running along my property. But the owners set very high prices for connections. One asks for 800 thousand rubles, the other 1.1 million rubles. This is not serious at all.

I did the math and it turned out that such a connection would pay for itself in 66 years. That is, the pipes are not public, but private.

That is, if connecting to gas costs 300,000 rubles (I also include the gas project, bringing gas into the house, connecting it to your heating system), then there is probably some kind of logic. So that it pays off for you (and then it will pay off for you for 20 years).

Now let's return to the heating system of a frame house using a heat accumulator and a night electricity tariff.

In what cases is this relevant?

➤ First - and most importantly - good insulation your house. A correctly done project and insulation in the walls is 150-200 mm, and in the ceiling 200-250 mm of basalt wool.

➤ The second is the availability of dedicated electrical power. You must have a minimum of 15 kW. That is, if you have a category of land for permanent residence, then power engineers by default provide you with a power of 15 kW in three phases. It's enough.

➤ The third parameter is the availability of a night tariff. If you, for example, connect to the Moesk system, they will offer you a night tariff (from 11 pm to 7 am) by default.

We will use this tariff to the maximum, when electricity is three times cheaper than during the day.

When is the best time to install and install a home heating system?

It is best to think about this at the design stage of your home. Because a heating system with a heat accumulator works most efficiently in conjunction with heated floors.

I have seen when a heat accumulator is used in conjunction with radiators. But the downside is that the heat accumulator is a large capacity. It is quite difficult to heat it; it requires a lot of power. And in principle, it can be heated to 80-85 ºС, and your radiator will remove all this in 3-4 hours. And by evening the house will get cold.

Often homeowners are unable to buy modern heating equipment, so they are looking alternative solutions. Take, for example, a buffer tank (otherwise known as a heat accumulator), an indispensable item for heating systems with a solid fuel boiler. A storage tank with a volume of 500 liters costs approximately 600-700 USD. That is, the price of a thousand-liter barrel reaches 1000 USD. e. If you make a heat accumulator with your own hands, and then install the tank in the boiler room yourself, you will be able to save half of the specified amount. Our task is to talk about manufacturing methods.

Where is a heat accumulator used and how is it designed?

A thermal energy storage device is nothing more than an insulated iron tank with pipes for connecting water heating lines. The buffer tank performs 2 functions: it accumulates excess heat and heats the house during periods when the boiler is inactive. The heat accumulator replaces the heating unit in 2 cases:

1. When heating a home or with a boiler that burns solid fuel. The storage tank works for heating at night, after wood or coal burns out. Thanks to this, the homeowner can relax in peace, rather than running to the boiler room. It is comfortable.
2. When the heat source is an electric boiler, and electricity consumption is recorded using a multi-tariff meter. Energy at the night rate is half the price, so during the day the heating system is completely powered by the heat accumulator. It's economical.

On the left in the photo is a 400 liter buffer tank from Drazice, on the right is a Kospel electric boiler complete with a hot water storage tank

Important point. A hot water accumulator tank increases the efficiency of a solid fuel boiler. After all, the maximum efficiency of a heat generator is achieved with intense combustion, which cannot be constantly maintained without a buffer tank that absorbs excess heat. The more efficiently wood is burned, the less it is consumed. This also applies gas boiler, whose efficiency decreases in low combustion modes.

A storage tank filled with coolant operates according to simple principle. While the heat generator is heating the rooms, the water in the tank is heated to a maximum temperature of 80-90 ° C (the heat accumulator is charging). After the boiler is turned off, hot coolant begins to flow to the radiators from storage tank, providing heating of the house for a certain time (the thermal battery is discharged). The duration of operation depends on the volume of the tank and the outside air temperature.

How does a factory-made heat accumulator work?

The simplest factory-made storage tank for water, shown in the diagram, consists of the following elements:

• the main tank is cylindrical in shape, made of carbon or stainless steel;
• thermal insulation layer 50-100 mm thick, depending on the insulation used;
• outer skin – thin painted metal or polymer cover;
• connecting fittings embedded into the main container;
• immersion sleeves for installing a thermometer and pressure gauge.

Note. More expensive models of heat accumulators for heating systems are additionally equipped with coils for hot water supply and heating from solar collectors. Another useful option is a block of electric heating elements built into the upper zone of the tank.

Factory production of heat storage devices

If you are seriously concerned about installing a heat accumulator and decide to make it yourself, then first you should familiarize yourself with the factory assembly technology.

Cutting on plasma apparatus blanks for lid and bottom

Repeat technological process in a home workshop is unrealistic, but some techniques will be useful to you. At the enterprise, the hot water storage tank is made in the form of a cylinder with a hemispherical bottom and a lid in the following order:

1. Sheet metal 3 mm thick is fed to the machine plasma cutting, where blanks for end caps, housing, hatch and stand are obtained from it.
2. The lathe produces main fittings with a diameter of 40 or 50 mm (1.5 and 2” thread) and immersion sleeves for control devices. A large flange is also machined there for inspection hatch about 20 cm in size. A pipe for insertion into the body is welded to the latter.
3. The body blank (the so-called shell) in the form of a sheet with holes for fittings is directed to rollers that bend it to a certain radius. To get a cylindrical container for water, all that remains is to butt weld the ends of the workpiece.
4. A hydraulic press presses hemispherical caps from metal flat circles.
5. Next operation – welding work. The order is as follows: first, the body is welded using tacks, then the lids are tacked to it, then all the seams are completely welded. At the end, fittings and an inspection hatch are attached.
6. The finished storage tank is welded to the stand, after which it undergoes 2 permeability tests - air and hydraulic. The latter is produced at a pressure of 8 bar, the test lasts 24 hours.
7. The tested tank is painted and insulated with basalt fiber no less than 50 mm thick. The top of the container is sheathed with thin sheet steel with a colored polymer coating or covered with a thick cover.

The storage housing is bent from a sheet of iron on rollers

Reference. To insulate the tank, manufacturers use different materials. For example, Prometheus heat accumulators Russian production insulated with polyurethane foam.

Instead of cladding, manufacturers often use a special cover (you can choose the color)

Most factory heat accumulators are designed for a maximum pressure of 6 bar at a coolant temperature in the heating system of 90 °C. This value is twice the response threshold of the safety valve installed in the safety group of solid fuel and gas boilers (limit - 3 Bar). Details manufacturing process shown in video:

We make a heat battery ourselves

You have decided that you cannot do without a buffer tank and want to make it yourself. Then get ready to go through 5 stages:

1. Calculation of the volume of the heat accumulator.
2. Choosing a suitable design.
3. Selection and preparation of materials.
4. Assembly and leak testing.
5. Installation of the tank and connection to the water heating system.

Advice. Before calculating the volume of the barrel, think about how much space in the boiler room you can allocate for it (in terms of area and height). Clearly decide how long the water heat accumulator should replace the inactive boiler, and only then proceed to the first stage.

How to calculate tank volume

There are 2 ways to calculate the capacity of a storage tank:

• simplified, offered by manufacturers;
• accurate, carried out according to the formula for the heat capacity of water.

The duration of heating a house with a heat accumulator depends on its size

The essence of the enlarged calculation is simple: for each kW of boiler plant power, a volume equal to 25 liters of water is allocated in the tank. Example: if the productivity of the heat generator is 25 kW, then the minimum capacity of the heat accumulator will be 25 x 25 = 625 l or 0.625 m³. Now remember how much space is allocated in the boiler room and adjust the resulting volume to actual sizes premises.

Reference. Those who want to weld a homemade heat accumulator often wonder how to calculate the volume of a round barrel. Here it is worth recalling the formula for calculating the area of ​​a circle: S = ¼πD². Substitute the diameter of the cylindrical tank (D) into it, and multiply the resulting result by the height of the tank.

You will get more exact dimensions heat accumulator if you use the second method. After all, a simplified calculation will not show how long the calculated amount of coolant will last under the most unfavorable conditions. weather conditions. The proposed method is based on the indicators you need and is based on the formula:

m = Q / 1.163 x Δt

• Q is the amount of heat that needs to be accumulated in the battery, kWh;
• m – estimated mass of coolant in the tank, tons;
• Δt – difference in water temperatures at the beginning and end of heating;
• 1.163 W h/kg °C is the reference heat capacity of water.

Let's explain further with an example. Let's take a standard house of 100 m² with an average heat consumption of 10 kW, where the boiler must be idle for 10 hours a day. Then it is necessary to accumulate 10 x 10 = 100 kWh of energy in the barrel. The initial water temperature in the heating network is 20 °C, heating occurs up to 90 °C. We calculate the mass of the coolant:

m = 100 / 1.163 x (90 - 20) = 1.22 tons, which is approximately 1.25 m³.

Please note that a heat load of 10 kW is taken approximately; in an insulated building with an area of ​​100 m², heat loss will be less. Point two: so much heat is needed on the coldest days, of which there are 5 for the entire winter. That is, a heat accumulator for 1000 liters is sufficient with a large margin, and taking into account the seasonal temperature difference, you can easily keep within 750 liters.

Hence the conclusion: you need to substitute the average heat consumption for cold period equal to half the maximum:

m = 50 / 1.163 x (90 - 20) = 0.61 tons or 0.65 m³.

Note. If you calculate the volume of the barrel based on the average heat consumption, in severe frosts it will not be enough for the calculated period of time (in our example - 10 hours). But you will save money and space in the furnace room. More information on making payments is presented in.

About the design of the container

To make your own heat accumulator, you will have to defeat one insidious enemy - the pressure exerted by the liquid on the walls of the vessel. Do you think why factory tanks are made cylindrical, and the bottom and lid are hemispherical? Yes, because such a container can withstand the pressure of hot water without additional reinforcement.

On the other hand, few people have the technical ability to form metal on rollers, not to mention drawing semicircular parts. We offer the following ways to resolve the issue:

1. Order a round internal tank from a metalworking enterprise, and carry out the insulation and final installation work yourself. It will still cost less than buying a factory-assembled heat accumulator.
2. Take a ready-made cylindrical tank and make a buffer tank on its base. We will tell you where to get such tanks in the next section.
3. Weld a rectangular heat accumulator from sheet iron and strengthen its walls.

Sectional drawing of a rectangular heat accumulator with a volume of 500 l

Advice. IN closed system heating with a solid fuel boiler, where overpressure can jump to 3 Bar and higher, it is strongly recommended to use a cylindrical heat accumulator.

In an open heating system with zero water pressure, you can use a rectangular tank. But do not forget about the hydrostatic pressure of the coolant on the walls; add to it the height of the water column from the container to the expansion tank installed at the highest point. This is why flat walls should be reinforced homemade heat accumulator, as shown in the drawing of a container with a capacity of 500 liters.

A properly reinforced rectangular storage tank can also be used in a closed heating system. But in the event of an emergency pressure surge from overheating of the TT boiler, the tank will leak with a 90% probability, although you may not notice a small crack under the insulation layer. Watch the video to see how the unstrengthened metal of the vessel bulges when filled with water:

Reference. It makes no sense to weld directly onto the walls stiffeners made of corners, channels and other rolled metal. Practice shows that the pressure force bends corners of a small section along with the wall, and tears off large ones at the edges.

Making a powerful frame from the outside is impractical, the consumption of materials is too high. A compromise option is the internal spacers shown in the drawing of a homemade heat accumulator.

Drawing of a 500 l heat accumulator - top view (cross section)

Selection of materials for the tank

You will make your task much easier if you find a ready-made cylindrical tank, initially designed for a pressure of 3–6 bar. What containers can be used:

• propane cylinders of different capacities;
• discarded process tanks, for example, receivers from industrial compressors;
• receivers from railway cars;
• old iron boilers;
• internal tanks of containers for storing liquid nitrogen, made of stainless steel.

From ready-made steel vessels making a reliable heat accumulator is much easier

Note. In extreme cases, a steel pipe of suitable diameter will do. Flat covers can be welded to it, which will have to be reinforced with internal braces.

To weld a square tank, take sheet metal 3 mm thick, no more is needed. Make rigidities from round pipes Ø15-20 mm or profiles 20 x 20 mm. Select the size of the fittings according to the diameter of the boiler outlet pipes, and for cladding, buy thin steel (0.3-0.5 mm) with powder painting.

A separate question is how to insulate a heat accumulator that you welded yourself. The best option is basalt wool in rolls with a density of up to 60 kg/m³ and a thickness of 60-80 mm. Polymers such as polystyrene foam or extruded polystyrene foam should not be used. The reason is mice that love warmth and in the fall can easily settle under the lining of your storage tank. Unlike polymer insulation, basalt fiber they don't chew.

Don't have any illusions about extruded polystyrene foam, rodents eat it too

Now we will indicate other options for ready-made vessels that are not recommended for use for heat accumulators:

1. An improvised tank made from a Eurocube. Similar plastic containers designed for maximum temperature contents are 70 °C, but we need 90 °C.
2. Thermal accumulator from iron barrel. Contraindications: thin metal and flat tank lids. Instead of strengthening such a barrel, it is easier to take a good steel pipe.

Assembly of a rectangular heat accumulator

We would like to warn you right away: if you have mediocre welding skills, then it is better to order the manufacture of the tank externally according to your drawings. The quality and tightness of the seams is of great importance; at the slightest leak, the storage container will leak.

First, the tank is assembled using tacks, and then welded with a continuous seam

For a good welder there will be no problems here, you just need to understand the order of operations:

1. Cut metal blanks to size and weld the body without a bottom and a lid using tacks. To secure the sheets, use clamps and a square.
2. Cut holes in the side walls for the stiffeners. Insert the prepared pipes inside and scald their ends from the outside.
3. Grab the bottom and lid to the tank. Cut holes in them and repeat the operation with the installation of internal braces.
4. When all the opposite walls of the container are securely connected to each other, begin continuous welding of all seams.
5. Install supports from pipe sections at the bottom of the tank.
6. Insert the fittings at a distance of less than 10 cm from the bottom and lid, as shown in the photo below.
7. Weld metal brackets to the walls, which will serve as brackets for fastening thermal insulation material and sheathing.

The photo shows a stretch made from a wide strip, but it is better to use a pipe

Advice on installing internal struts. To ensure that the walls of the heat accumulator effectively resist bending and do not break due to welding, extend the ends of the stretch marks outward by 50 mm. Then additionally weld stiffeners from a steel sheet or strip to them. ABOUT appearance don’t worry, the ends of the pipes will then disappear under the cladding.

Steel brackets (clips) are welded to the body to secure insulation and sheathing

A few words about how to insulate a heat accumulator. First, check it for leaks by filling it with water or lubricating all the seams with kerosene. Thermal insulation is quite simple:

• clean and degrease all surfaces, apply primer and paint to protect them from corrosion;
• wrap the tank with insulation without squeezing it, and then secure it with a cord;
• cut the facing metal, make holes in it for the pipes;
• Screw the casing to the brackets with self-tapping screws.

Screw the cladding sheets so that they are connected to each other with fasteners. This completes the production of a homemade heat accumulator for an open heating system.

Installation and connection of the tank to heating

If the volume of your heat accumulator exceeds 500 liters, then it is not advisable to place it on a concrete floor; it is better to arrange separate foundation. To do this, dismantle the screed and dig a hole to a dense layer of soil. Then fill it with broken stone (rubble), compact it and fill it with liquid clay. Fill the top reinforced concrete slab 150 mm thick in wooden formwork.

Scheme of the foundation for the battery tank

The correct operation of a heat accumulator is based on the horizontal movement of hot and cooled flow inside the tank when the battery is “charging”, and the vertical flow of water during “discharging”. To organize such battery operation, you need to perform the following steps:

• the circuit of a solid fuel or other boiler is connected to a water storage tank through a circulation pump;
• The heating system is supplied with coolant using a separate pump and mixing unit With three way valve, allowing you to select from the battery required amount water;
• the pump installed in the boiler circuit should not be inferior in performance to the unit supplying coolant to the heating devices.

Tank-heat accumulator wiring diagram

The standard connection diagram for a heat accumulator with a TT boiler is shown above in the figure. The balancing valve on the return line serves to regulate the coolant flow based on the water temperature at the inlet and outlet of the tank. Our expert Vladimir Sukhorukov will tell you how to properly strap and set up in his video:

Reference. If you live in the capital of the Russian Federation or the Moscow region, then regarding the connection of any heat accumulators, you can consult personally with Vladimir, using the contact information on his official website.

Budget storage tank made from cylinders

For those homeowners whose boiler room area is very limited, we suggest making a cylindrical heat accumulator from propane cylinders.

Homemade heat storage device paired with a TT boiler

The 100 l design, developed by another of our masters, is designed to perform 3 functions:

• unload the solid fuel boiler when overheating, taking in excess heat;
• heat water for household needs;
• provide heating of the house for 1-2 hours in case of extinguishing of the TT boiler.

Note. The battery life of the heat accumulator is short due to its small volume. But it will fit in any furnace room and will be able to remove heat from the boiler after a power outage, since it is connected directly, without a pump.

This is what a tank made of cylinders looks like without lining

To assemble the storage tank you will need:

• 2 standard propane cylinders;
• at least 10 m of copper tube Ø12 mm or stainless corrugation of the same diameter;
• fittings and sleeves for thermometers;
• insulation – basalt wool;
• painted metal for cladding.

You need to unscrew the valves from the cylinders and cut off the caps with a grinder, filling them with water to prevent the remaining gas from exploding. Copper tube carefully bend it into a coil around another pipe of a suitable diameter. Then we proceed like this:

1. Using the presented drawing, drill holes in the future heat accumulator for pipes and sleeves for thermometers.
2. Secure by welding several metal brackets inside the cylinders for mounting the DHW heat exchanger.
3. Place the cylinders one on top of the other and weld them together.
4. Install a coil inside the resulting tank, releasing the ends of the tube through the holes. Use gland packing to seal these areas.
5. Attach the bottom and lid.
6. Insert an air vent into the lid and a drain valve into the bottom.
7. Weld the brackets to secure the casing. Make them of different lengths so that the finished product has rectangular shape. It will be inconvenient to bend the cladding in a semicircle, and it will not be aesthetically pleasing.
8. Insulate the tank and fasten the casing with self-tapping screws.

Connecting a tank to a TT boiler without a circulation pump

The design feature of this heat accumulator is that it is connected to a solid fuel boiler directly, without a circulation pump. Therefore, for docking they use steel pipesØ50 mm, laid with a slope, the coolant circulates by gravity. To supply water to the heating radiators, a pump + three-way mixing valve is installed after the buffer tank.

Conclusion

On many Internet resources there is a statement that making a heat accumulator with your own hands is a piece of cake. If you study our material, you will understand that such statements are far from reality; in fact, the issue is quite complex and serious. You can't just take a barrel and fit it to solid fuel boiler. Hence the advice: think carefully about all the nuances before starting work. And without a welder’s qualifications, it’s not worth taking on a buffer tank; it’s better to order it from a specialized workshop.