Making a buffer container with your own hands. How to make your own heat accumulator for a heating boiler

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 is electrical energy. In addition, new technologies are increasingly being used that make it possible 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 the high cost of energy consumed. It is obvious that 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 would help by including in the general scheme a special device that would accumulate the currently unclaimed thermal energy and give it away as needed. 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.

Normal work solid fuel boiler characterized by a pronounced alternation of peaks and troughs in thermal energy production

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 significant cost savings. 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 minimum consumption her 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, a special device called a heat accumulator (thermal accumulator, buffer tank) is used.

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. It is better to consider the simplest scheme using 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 (KHP), 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 cooled and hot water, there will be no active mixing in the tank - during the combustion of the fuel fill, the heat exchanger 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 of the fuel (minus, of course, the inevitable losses reflected in the efficiency of the boiler) is converted into heat, which is accumulated in the heating element. 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. Again, intensive independent mixing is not observed - for the reason already mentioned, and the supply pipe receives hot water, the cooled one 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 fixed time in the evening and in the morning, and during the day the heating circuits will be powered only (or mainly) 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. And here internal structure 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 the permissible values for the 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 from overgrowing the internal walls of the tank. Subject to periodic replacement.

3 – The heat accumulator is supplemented with a flow-through hot water supply circuit. Entrance cold water carried out from below, 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 indirect heating boiler.

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 - choice specific model depends on the complexity of the heating system being created, the number 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 operating modes of the heat exchange devices are adjusted according to qualitative principle– with a change in coolant temperature. 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 an auxiliary role in the overall heating scheme. 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 reality, connecting a heat accumulator to complex, branched systems, with different contours heating systems, and even those receiving heat from sources of different power and temperature, require highly professional design with engineering thermal calculations, using many additional control 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 electric heaters – heating elements – built into it. Sometimes it is beneficial to support with their help set temperature 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 the level set by the user. 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 you still need 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 boiler power, required quantity energy for heating and hot water supply. In a word, the capacity must be such as to ensure the accumulation of all excess on this moment 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, of course, more expensive, but their warranty period is also much longer.
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 of additional options - the possibility of installing heating elements, installing instrumentation, 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 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 are installed on all pipes entering the heat accumulator mechanical cleaning water - “mud collectors”.
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 that can only be accomplished by 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.

Maximum power boiler is usually known - this is the nameplate value designed for optimal solid fuel water. 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 short, the value of the thermal energy demand of a particular building is necessary to ensure comfortable conditions accommodation.

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. The reader can get acquainted with the calculation algorithm, including a convenient calculator, by opening the publication dedicated to it using 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– Efficiency of the boiler installation. 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. It can be determined experimentally for your system by 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.

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 loading solid fuel into the boiler. It is a reservoir into which there is no air access. It is insulated and has enough 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. The use of a large heat accumulator for heating in temporary country houses is impractical, and a small reservoir 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 sizes 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;
higher installation costs.

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 production models manufactured in 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 the set 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 circuits are made of pipes large section, besides, not always convenient slopes must be observed. If you calculate the price of pipes and fittings, weigh all the inconveniences of installation and compare all this with the price of a UPS, then the idea of installing alternative source nutrition 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 required volume 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, with the correct volume of 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.

How to organize the operation of an autonomous heating system in economical mode? It is necessary to install a heat accumulator for heating boilers. As a result, efficiency will significantly increase while fuel costs will be reduced, and the overall cost of maintaining the property will also be reduced.

We will talk about how the unit works, which allows you to collect and store the heat generated by the boiler. We describe in detail all the device options used in everyday life. The article we presented describes the scope of application of heat accumulators and operating rules.

A heat accumulator is a buffer reservoir designed to accumulate excess heat volumes generated during boiler operation. The saved resource is then used in the heating system in the period between scheduled loads of the main fuel resource.

Connecting a properly selected battery allows you to reduce the cost of purchasing fuel (in some cases up to 50%) and makes it possible to switch to one load per day instead of two.

In addition to the function of accumulating the generated heat, the buffer tank provides protection cast iron units from cracking in the event of an unexpected and sharp change in the temperature of the working supply water

If you equip the equipment with intelligent controllers and temperature sensors, and supply heat from storage tank automation into the heating system, heat transfer will increase significantly, and the number of portions of fuel loaded into the combustion chamber of the heating unit will noticeably decrease.

Features of internal and external devices

The heat accumulator is a vertical cylinder-shaped tank made of high-strength black or stainless steel sheet.

There is a layer of bakelite varnish on the inner surface of the device. It protects the buffer tank from the aggressive influence of industrial hot water, weak salt solutions and concentrated acids. Powder paint is applied to the outside of the unit, resistant to high thermal loads.

The tank volume varies from 100 to several thousand liters. The most spacious models have large linear dimensions, making it difficult to place equipment in the limited space of a home boiler room

External thermal insulation is made of recycled polyurethane foam. The thickness of the protective layer is about 10 cm. The material has a specific complex weave and an internal polyvinyl chloride coating.

This configuration prevents particles of dirt and small debris from accumulating between the fibers, provides a high level of water resistance and increases the overall wear resistance of the heat insulator.

The heat insulator is not always included in the heat accumulator kit. Sometimes you have to buy it separately and then install it on the unit yourself

The surface of the protective layer is covered with a leatherette cover good quality. Thanks to these conditions, the water in the buffer tank cools much more slowly, and the level of overall heat loss of the entire system is significantly reduced.

The operating principle of a heat-saving product

The heat accumulator operates according to the simplest scheme. A pipe from a gas, solid fuel or electric boiler is connected to the unit from above.

According to her storage tank hot water comes in. Cooling down during the process, it falls down to the location of the circular pump and, with its help, is fed back into the main passage to return to the boiler for the next heating.

Installing a heat accumulator prevents overheating of the coolant when the boiler is operating at full power and ensures maximum heat transfer with economical fuel consumption. This reduces the load on the heating system and extends its service life

A boiler of any type, regardless of the type of fuel resource, operates in steps, periodically turning on and off when the optimal temperature of the heating element is reached.

When work stops, the coolant enters the reservoir, and in the system it is replaced by hot liquid that has not cooled due to the presence of a heat accumulator. As a result, even after the boiler is turned off and goes into passive mode until the next fuel supply, the batteries remain hot for some time, and warm water comes out of the tap.

Types of heat storage models

All buffer tanks perform almost the same function, but have some design features.

Manufacturers produce three types of storage units:

hollow(without internal heat exchangers);
with one or two coils ensuring more efficient operation of equipment;
with built-in boiler tanks Not large diameter, designed for the correct operation of an individual hot water supply complex for a private home.

The heat accumulator is connected to the heating boiler and the communication wiring of the home heating system through threaded holes located in the outer casing of the unit.

How does a hollow unit work?

The device, which has neither a coil nor a built-in boiler inside, is one of the simplest types of equipment and costs less than its more “sophisticated” counterparts.

It is connected to one or more (depending on the needs of the owners) energy sources through central communications, and then through 1 ½ pipes it is routed to points of consumption.

It is planned to install an additional heating element operating on electrical energy. The unit provides high-quality heating of residential property, minimizes the risk of coolant overheating and makes operation of the system completely safe for the consumer.

When a residential building already has a separate hot water supply system and the owners do not plan to use solar thermal heat sources to heat the room, it is advisable to save money and install a hollow buffer tank in which all effective area the tank is given to the coolant, and is not occupied by coils

Thermal accumulator with one or two coils

A heat accumulator equipped with one or two heat exchangers (coils) is a progressive option for equipment with a wide range of applications. The upper coil in the design is responsible for the selection of thermal energy, and the lower one carries out intensive heating of the buffer tank itself.

The presence of heat exchange units in the unit allows you to receive hot water for domestic needs around the clock, heat the tank from the solar collector, warm up house paths and make the most efficient use of useful heat for any other convenient purposes.

Module with internal boiler

A heat accumulator with a built-in boiler is a progressive unit that not only accumulates excess heat generated by the boiler, but also ensures the supply of hot water to the tap for domestic purposes.

The internal boiler tank is made of stainless alloy steel and equipped with a magnesium anode. It reduces the level of water hardness and prevents the formation of scale on the walls.

Owners choose the appropriate volume of the buffer tank on their own, but experts say that there is no practical point in purchasing a tank less than 150 liters

A unit of this type connects to various energy sources and works correctly with both open and closed systems. Controls the temperature level of the operating coolant and protects the heating complex from overheating of the boiler.

Optimizes fuel consumption and reduces the number and frequency of loading. Compatible with solar collectors of any model and can function as a substitute for a hydraulic boom.

Scope of application of the heat accumulator

The heat accumulator collects and stores the energy generated by the heating system, and then helps to use it as efficiently as possible for efficient heating and providing residential premises with hot water.

You need to purchase a device for accumulating excess heating resources only in specialized stores. The seller must provide the buyer with a product quality certificate and full instructions by use

Work with different types equipment, but most often used in conjunction with solar collectors, solid fuel and electric boilers.

Thermal accumulator in a solar system

A solar collector is a modern type of equipment that allows you to use free solar energy for everyday household needs. But without a heat accumulator, the equipment is not able to fully function, since it supplies unevenly. This is due to changes in time of day, weather conditions and seasonality.

A solar collector equipped with a heat accumulator is placed on the south side of the site. There the device absorbs maximum energy and gives effective output

If the heating and water supply system is powered only by a single energy source (the sun), at some points residents may experience serious problems with the supply of resources and receipt of familiar elements of comfort.

A heat accumulator will help you avoid these unpleasant moments and make the most efficient use of clear, sunny days to accumulate energy. To work in a solar system, it uses high heat capacity water, 1 liter of which, cooling by just a degree, releases thermal potential to heat 1 cubic meter of air by 4 degrees.

The solar collector and heat accumulator make up unified system, which makes it possible to use solar energy as the only source for heating a residential building

During the period of peak solar activity, when it collects maximum amount light and energy production significantly exceeds consumption, the heat accumulator accumulates the excess and supplies it to the heating system when the supply of resources from the outside decreases or even stops, for example, at night.

The following article will introduce you to the options and schemes for country property, which we recommend reading.

Buffer tank for solid fuel boiler

Cyclicity is a characteristic feature of work. At the first stage, firewood is loaded into the firebox and heating occurs for some time. Maximum power and most high temperatures observed at the peak of bookmark combustion.

Then the heat transfer gradually decreases, and when the wood finally burns out, the process of generating useful heating energy stops. All boilers operate on this principle, including long-burning appliances.

It is not possible to precisely configure the unit to generate thermal energy in relation to the level of consumption required at any given moment. This function is only available in more advanced equipment, for example, in modern gas or electric heating boilers.

Therefore, immediately at the moment of ignition and when reaching actual power, and then during the process of cooling and the forced passive state of the equipment, there may simply not be enough thermal energy for full heating and heating of hot water.

But during peak operation and the active phase of fuel combustion, the amount of energy released will be excessive and most of, literally, “will go down the drain.” As a result, the resource will be spent irrationally, and the owners will have to constantly load new portions of fuel into the boiler.

In order for the house to be heated for a long time after the solid fuel boiler is turned off, you need to purchase a buffer tank big size. It will not be possible to accumulate a significant amount of resource in a small reservoir and its purchase will be a pointless waste of money

This problem is solved by installing a heat accumulator, which will accumulate heat in the tank at times of increased activity. Then, when the wood burns out and the boiler goes into passive standby mode, the buffer will transfer the collected energy, which will warm up and begin to circulate through the system, heating the room bypassing the cooled appliance.

Reservoir for electrical system

Electric heating equipment is a rather expensive option, but it is sometimes installed, and, as a rule, in conjunction with a solid fuel boiler.

Usually installed where other sources of heat are not available due to objective reasons. Of course, with this heating method, electricity bills increase significantly and home comfort costs the owners a lot of money.

The buffer tank must be installed directly next to the heating boiler. The equipment has substantial dimensions and in a private house you will have to allocate a special room for it. The system will fully pay for itself within 2-5 years

In order to reduce electricity costs, it is advisable to use the equipment to the maximum during the preferential tariff period, that is, at night and on weekends.

But such an operating mode is possible only if there is a capacious buffer tank, where the energy generated during the grace period will accumulate, which can then be spent on heating and supplying hot water to residential premises.

Do-it-yourself energy storage device

The simplest possible model of a heat accumulator can be made with your own hands from a ready-made steel barrel. If you don’t have one at your disposal, you will have to purchase several sheets of stainless steel with a thickness of at least 2 mm and weld them into a container of a suitable size in the form of a vertical cylindrical tank.

It is not recommended to use a Eurocube to make a heat accumulator. It is designed for contact with coolant having an operating temperature of up to + 70 ºС and simply will not withstand hotter liquids

DIY Guide

To heat the water in the buffer you will need to take copper tube with a diameter of 2-3 centimeters and a length of 8 to 15 m (depending on the size of the tank). It will have to be bent into a spiral and placed inside the tank.

The battery in this model will be top part barrels. From there you need to remove the outlet pipe for the hot water outlet, and make the same one from below for the cold water inlet. Each outlet should be equipped with a tap to control the flow of liquid into the accumulation zone.

In an open heating system, a rectangular steel tank can be used as a buffer tank. IN closed system this is excluded due to possible surges in internal pressure

On next stage it is necessary to check the container for leaks by filling it with water or lubricating the welded seams with kerosene. If there is no leak, you can proceed to creating an insulating layer that will allow the liquid inside the tank to remain hot for as long as possible.

How to insulate a homemade unit?

To begin with, the outer surface of the container must be thoroughly cleaned and degreased, and then primed and painted with heat-resistant paint. powder paint, thus protecting against corrosion.

Then wrap the tank glass wool insulation or roll basalt wool 6-8 mm thick and secure it with cords or regular tape. If desired, cover the surface with sheet metal or “wrap” the tank in foil film.

You should not use extruded polystyrene foam or polystyrene foam for insulation. With the onset of cold weather, these materials may harbor mice looking for a warm place to live during the winter.

In outer layer Holes for the outlet pipes should be cut and the container should be connected to the boiler and heating system.

The buffer tank must be equipped with a thermometer, internal pressure sensors and an explosion valve. These elements allow you to control potential overheating of the barrel and relieve excess pressure from time to time.

Accumulated resource consumption rate

It is impossible to accurately answer the question of how quickly the heat accumulated in the battery is consumed.

How long it will work on a resource collected in a buffer tank directly depends on such items as:

actual volume of storage capacity;
level of heat loss in the heated room;
outside air temperature and current time of year;
set values of temperature sensors;
useful area of the house that needs to be heated and supplied with hot water.

Heating of a private house in a passive state of the heating system can be carried out from several hours to several days. At this time, the boiler will “rest” from the load and its working resource will last for a longer period of time.

Rules for safe operation

Do-it-yourself heat accumulators at home are subject to special requirements security:

Hot tank elements must not come into contact with or otherwise come into contact with flammable or explosive materials or substances. Ignoring this point may cause a fire in individual objects and a fire in the boiler room.
Closed heating system assumes constant high pressure of the coolant circulating inside. To ensure this point, the tank structure must be completely sealed. Additionally, its body can be reinforced with stiffening ribs, and the lid on the tank can be equipped with durable rubber gaskets that are resistant to intense operating loads and elevated temperatures.
If the design contains an additional heating element, its contacts must be very carefully insulated, and the tank must be grounded. In this way, it will be possible to avoid electric shock and short circuit, which can damage the system.

If these rules are followed, the operation of a self-made heat accumulator will be completely safe and will not cause any problems or hassle for the owners.

Conclusions and useful video on the topic

Installing a heat accumulator for a home heating system is very profitable and economically justified. The presence of this unit reduces labor costs for lighting the boiler and allows you to add a heating resource not twice a day, but only once.

The fuel consumption required for the correct operation of heating equipment is significantly reduced. The heat produced is used optimally and is not wasted. Costs for heating and hot water supply are reduced, and living conditions become more convenient, comfortable and enjoyable.

Tell us about how you installed the heat accumulator on your boiler. Share the technological details of the process and your impressions of the efficiency of the device. Please leave comments in the block below, post photos, and ask questions about controversial issues.

The heat accumulator contains a large volume of water (coolant), so it can accumulate thermal energy and release it when the boiler is not working. This allows you to approach the solid fuel boiler much less often, in fact once every two days in the off-season, if the boiler is powerful and the house is insulated, and also makes it possible to use cheap heating to the maximum for the benefit of heating. night rate electricity.

The idea of installing a buffer tank (heat accumulator) looks brilliant for everyone who is tired of being on duty at the boilers, but it breaks down due to the price tag for heat accumulators. It turns out that increasing comfort is not very cheap. But maybe you can make a heat accumulator with your own hands? After all, at first glance there is nothing complicated...

How to make a heat accumulator

The factory design of the heat accumulator is usually a barrel, round in cross-section. The volume is usually between 500 and 2000 liters. Diameter - up to a meter, height up to 2.5 meters. Placed on legs, with many welded fittings. It may contain 1 or 2 or more spiral heat exchangers for connecting independent circuits, for example, a solar collector, heating running water...

The container is insulated with a layer of thermal insulation so as not to overheat the air in the boiler room. Branded heat accumulators have a complex flow distribution inside... You can take a look at the Buderus advertisement in the video...

The basis for designing a buffer tank is how flows should be directed

To create the correct flow direction, connections to the buffer tank are made as follows.

The supply from the boiler is at the top.
Supply from the tank to the radiators - in the upper part, at the level of the boiler supply
The return from the radiators is in the lower part.
The return to the boiler is in the lower part, just below the return from the radiators.

In this case, the liquid in the heat accumulator must necessarily move from top to bottom, along the boiler circuit ring, and also from the boiler to the radiators.

You can track the direction of fluid movement using temperature sensors - the boiler return should be warmer than the radiator return.

It is important to follow the principle: – the coolant flow in the boiler circuit must exceed the flow in the radiators, only then the heat accumulator can operate normally. This is usually ensured by high hydraulic resistance of the consumer circuit, with identical pumps.

The radiators will receive hot coolant as soon as it appears inside the heat accumulator, taking it from the top with its pump, which ensures efficient control of all heating and response to daily temperature changes.

The most important issue when installing a heat accumulator is protecting the boiler from cold return flow, which must be done, for example, using a three-way valve.

Buffer tank design basics

It is much preferable to use a large ready-made barrel or pipe, then there will be much fewer welds than in a homemade rectangular structure.

3/4 inch pipes are welded in to connect the circuits. But to implement emergency gravity circulation, it is advisable to create a circuit of a solid fuel boiler of at least 1 inch, while the supply from the boiler, where overheating is possible, is steel.
The drain pipe, which is also the sludge cleaner, is at the very bottom.
It is recommended to create a large diameter pipe in the lid to connect an automatic air vent or safety group.

Only a qualified welder can make a buffer tank independently. An example of creating a heat accumulator from barrels, but obvious circuit design errors should not be repeated...

One of the solutions promoted by some experts is 4 cheap 200 liter barrels connected in pairs with large diameter pipes...

How much buffer capacity will be needed?

The key question is how much heat storage capacity can be considered sufficient. The normal operating mode is heating up to +90 degrees and cooling down to +60 degrees, until the radiators work effectively... The difference of 30 degrees is the energy that can be accumulated and used.

A simple thermal calculation shows that one ton of water will be enough to heat a moderately insulated house of 100 sq. m during the most extreme frosts for 5 hours. And at average seasonal temperatures - a day.

In practice, a capacity of 1.2 tons in a well-insulated small house allows you to avoid going near a 30 kW boiler on wood for 2 days... There is no particular point in installing a buffer capacity of less than 0.8 tons...

The issue of insulation

There is no need to rush to apply insulation until complete heat and pressure tests have been completed. When heated above 60 degrees, polystyrenes begin to rapidly decompose, releasing poison. For the buffer tank, it is better to use loose mineral wool 5 cm thick; insulate it from the living space with foil-lined polyethylene foam taped with tape.

Buffer container made of Eurocube

You can inexpensively purchase used polyethylene containers for a ton of water, located in a metal lattice. Their permissible heating limit is +70 degrees, above which the fluidity of the material begins to appear. But among the advantages is the extremely low cost of production; you can do everything yourself without involving a welder... Watch the video to see what comes of it.

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 made of mineral wool or polyethylene foam.

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) 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 in the required mode transfers 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 essentially. When the battery capacity is heated, the boiler constantly operates at full power, and this avoids the appearance of tarry condensate in the boiler.

How does a heat accumulator work?

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

The container has several pipes for connecting various equipment:

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

Materials of water-containing container.

Carbon steel of various grades with (or without) protective enamel or varnish applied to the inner surface is the cheapest and therefore most common material.
Stainless steel is the most durable material that is not subject to corrosion. Its main disadvantage is its high price.
Fiberglass - this “exotic” material is used to make dismountable heat accumulators, which are assembled directly on site. This method allows you to carry the TA along the narrowest stairs and assemble it exactly in the right place. If interested, watch the video of what it looks like

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 (). I recommend reading a separate article dedicated to this useful device. Let me say briefly that such a connection scheme eliminates the mutual influence of different ones and makes it possible to provide the boiler 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 it separately, but I believe that this can only be done if you have the necessary space in your boiler room.

Summary.

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.