Thermal accumulator for heating operating principle. Heating by heat accumulator at night electricity tariff. Prices for S-Tank heat accumulators
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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.
WITH solid fuel boiler this is difficult to implement, 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 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 wide range;
- For getting hot water installation of an additional heat exchanger or external boiler with indirect heating is required, 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;
- Solid fuel boiler, even long burning, constantly requires the user's attention. As soon as you miss the time for adding a new portion of fuel, the coolant in the heating circuit is already beginning 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:
Calculation
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;
- WITH - specific heat 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.
The stored energy must be sufficient for the intended use of the heat accumulator.
To select the required volume of the heat accumulator, it is necessary to determine:
- The time during which the accumulated energy in the heat exchanger should be enough to cover the heat loss of the house;
- The time during which the coolant in the heat exchanger must heat up;
- Power of the main heat source.
For periodic operation of the boiler during the day
If it is needed to switch the boiler operation only to night or day mode, when heat is supplied for a limited time, then the TA power should be enough to cover the heat loss of the house for the remaining time. At the same time, the boiler’s power should be enough to heat the heating unit in a timely manner and, again, to heat the house.
Let's assume that a solid fuel boiler is used with firewood only during the day for 10 hours, the estimated heat loss of the house for the coldest period of the year is 5 kW. 120 kW*hours are required per day for full heating.
The battery is used for 14 hours, which means that it needs to accumulate 5 kW * 14 hours = 70 kW * hours of heat. If you take water as a coolant, you will need 1.75 tons or a heat exchange volume of 1.75 m3. It is important that the boiler must produce all the necessary heat within just 10 hours, that is, its power must be more than 120/10 = 12 kW.
If the heat accumulator is used as a backup option in case of boiler failure, then the stored energy should be enough for at least a day or two to cover all heat losses in the house. If we take the same 100 m2 house as an example, then heating it will require 240 kW*hours in two days, and the heat accumulator filled with water must have a volume of at least 5.3 m3.
But in this case, the TA does not necessarily have to heat up in a short period of time. A boiler power reserve of one and a half is enough to accumulate the required amount of heat in a week or two.
The calculation is approximate, without taking into account the reduction in the thermal power of radiators depending on the temperature of the coolant and air in the room.
In the simplest case, the heat accumulator is connected in series between the boiler and the heating circuit. A circulation pump is installed between the heating element and the boiler so that hot water enters the upper part of the heating element, pushing out cold water from the bottom into the boiler. A circulation pump is installed between the heat exchanger and the heating circuit to draw hot water from the upper part and transport it to the radiators.
However, this significantly increases the overall heat capacity of the system, and when starting the heating initially, you will have to wait until the entire volume of the heat exchanger is heated before the heat reaches the radiators.
Another option for switching on is parallel to the heating boiler. This option works well in combination with gravity system heating. The upper outlet of the heat accumulator is connected to the highest point of the distribution box, and at the lower point - to the boiler.
The disadvantages are the same as in the first case; the entire volume of coolant in the system and in the heater is heated, which significantly increases the time to start heating.
The only advantages are ease of connection and a minimum of elements used.
Switching circuit with mixing
The best thing use a switching circuit with mixing or hydraulic isolation. Three-way valves with a thermostat are used. The heat accumulator is installed as separate element system, parallel to the heating circuit.
The main part of the automation is installed on the supply pipeline: three-way valve, thermostats, safety group, etc. By default, the three-way valve directs the coolant from the boiler to the radiators until the room temperature reaches the required level.
As soon as there is no need for active heating, the valve transfers part of the coolant from the boiler to the heat accumulator, discharging excess heat.
Upon reaching maximum temperature water in the heater and the target temperature in the radiators, the sensor installed in the boiler is triggered by overheating and it turns off. While heating is required or the heat accumulator is not warmed up, the boiler continues to operate.
If for some reason the boiler stops producing rated power or switches off completely when the temperature on the supply line drops, water from the heat accumulator is mixed into the heating circuit, replenishing the heat loss of the system.
You can use several three way valves on the supply and return lines and a group of thermostats. As an option, ready-made assemblies for connecting heat accumulators are available for sale - an automatic mixing unit, for example LADDOMAT.
With your own hands
If you really want, you can build a storage tank with your own hands. Ideally she should:
- withstand with reserve nominal pressure in system;
- have a calculated volume;
- be protected from corrosion and high temperatures;
- be completely sealed.
For manufacturing, you should take sheet steel, preferably stainless steel with a thickness of at least 3 mm, taking into account the total load and pressure.
The standard TA shape is a tall cylinder with a semicircular base and lid. The ratio of diameter to height is selected to be approximately 1 to 3-4 to promote better heat distribution inside the container.
In this case, hot water is taken from the highest point to the radiators. Just above the center, the water is diverted to the heated floor circuit, and at the lowest point of the TA the return line is connected to the heating boiler.
It is almost impossible to weld a cylindrical container yourself. It is easier to build a parallelepiped with a similar configuration and aspect ratio. All corners should be further strengthened.
The container must be insulated. It is better to use basalt or mineral wool thickness of at least 150 mm, to reduce heat loss through the walls.
To install the heat accumulator, you should prepare a special support platform, foundation, capable of supporting the enormous weight of equipment. Even the battery itself can weigh up to 400-500 kg. If its volume is, for example, 3 cubic meters, then when filled its weight will exceed 3.5 tons.
Russian made
On Russian market There are not many domestically produced heat accumulators presented, since only recently they began to be actively introduced into autonomous heating systems.
| Model | Additional options | volume, m3 | Operating pressure, bar | Maximum temperature, ºС | Approximate cost, rub |
| Sibenergo-therm | — | 0.5 | 6 | 90 | 28500 |
| PROFBAK | DHW circuit | 0.5 | 3 | 90 | 56000 |
| GidroNova-HA750 | Electric heating element | 0.75 | 3 | 95 | 58000 |
| ELECTROTHERM ET 1000 A | DHW circuit, additional heat exchanger | 1.0 | 6 | 95 | 225000 |
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. Application of a large heat accumulator for heating in country houses temporary residence is impractical, and a small tank is of little use. This is due to the operating principle of the heat accumulator for the heating system.
- TA is located between the boiler and the heating system. When the boiler heats the coolant, it enters the heat exchanger;
- then the water flows through pipes to the radiators;
- the return flow returns to the TA, and then directly to the boiler.
Although the heat accumulator for the heating system is a single vessel, due to its large 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 heat always rises, but the cold tends to fall. It is necessary to create such conditions so that part of the heat sinks to the bottom of the heat accumulator in the heating system and heats the return coolant. If the temperature is equalized throughout the tank, then it is considered fully charged.
After the boiler has burned out everything that was loaded into it, it stops working and the TA comes into play. The circulation continues and it gradually releases its heat through the radiators into the room. All this happens until the next portion of fuel enters the boiler again.
If the heat accumulator for heating is small, then its reserve will last only for a short time, while the heating time of the batteries increases, since the volume of coolant in the circuit has become larger. Disadvantages of using for temporary residences:
- the room warm-up time increases;
- larger volume of the circuit, which makes filling it with antifreeze more expensive;
- more high costs for installation.
As you understand, filling the system and draining water every time you arrive at 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. He will provide for the whole house necessary warmth and hot water at the same time. Accordingly, the heater's performance will be fully used.
In serial models manufactured under production conditions, additional heating sources are built in. These are also spirals, only they are called electric heating elements. There are often several of them and they can work from different sources:
- circuit;
- solar panels.
Such heating is an additional option and is not mandatory; keep this in mind if you decide to make a heat accumulator for heating with your own hands.
Heat accumulator wiring diagrams
We dare to suggest that if you are interested in this article, then, most likely, you have decided to make a heat accumulator for heating and its wiring with your own hands. You can come up with many connection schemes, the main thing is that everything works. If you correctly understand the processes occurring in the circuit, then you can experiment. How you connect the TA to the boiler will affect the operation of the entire system. Let's first look at the most simple diagram heating with a heat accumulator.
A simple TA strapping scheme
In the figure you see the direction of movement of the coolant. Please note that upward movement is prohibited. To prevent this from happening, the pump between the heating element and the boiler must pump a larger amount of coolant than the one that stands before the tank. Only in this case will a sufficient drawing force be generated, which will remove part of the heat from the supply. The disadvantage of this connection scheme is long time heating 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
Created in TA correct movement water, which allows ball by ball, starting from the top, to warm it up. The question may arise, what to do if there is no light? We talked about this in an article about . It will be more economical and convenient. After all, gravity contours are made of large-section pipes, and in addition, inclines that are not always convenient must be observed. If you calculate the price of pipes and fittings, weigh all the 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, there are also pyrolysis boilers into 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 works in tandem with a leaky heating system, then at peak temperatures the expansion tank sometimes 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.
The main goals of the design and installation of an autonomous heating system are comfort in the home and trouble-free operation. Therefore, those people who believe that to achieve comfort it is enough to simply install a boiler and connect it to the heating system are mistaken.
And this mistake lies in the fact that sooner or later any boiler, even the best quality, can fail. And most often this happens in the midst of heating season, when the equipment operation mode is most intensive. How can you insure yourself in such a case?
There are several options:
- Have a regular stove in your home that is in working order.
- Have two boilers, one of which, with a lower power, is used only in an emergency.
- Include a device in the heating system that allows you to accumulate thermal power during operation of the boiler, capable of maintaining the temperature of the coolant at the proper level for a sufficiently long time when it stops.
The first option is good for those houses that previously had stove heating, and then were equipped with their own boiler room. It is unlikely that anyone will build a stove in a new house, for which heating from a boiler was initially provided. The second option is used infrequently, but has a right to life. Usually the main one here is a solid fuel and gas unit, and the spare one is an electric boiler, which is not very high power, used exclusively as backup source heat.
But the third option from the point of view of reliability is the most optimal. This device is called a heat accumulator and is most often used in systems equipped with boilers periodic action. Most often, these are solid fuel boilers (which need to be loaded with fuel several times a day) and electric units, which are profitable to turn on only at night (if electricity is cheaper at night).
What is a heat accumulator (TA)
A heat accumulator is a reservoir of a certain (rather large) capacity filled with a coolant (usually water). The tank must be well insulated from external environment. At the same time, during operation of the boiler, due to the high heat capacity of water, the coolant is heated throughout the entire volume of the tank. Due to this, a large reserve of thermal power is created, providing stable work heating and hot water supply systems (if any) during the entire boiler downtime. Moreover, the reason for the downtime is not important - it could just be a break between fireboxes or an accident.
Even if the tank volume is sufficient, big house able to last up to 2 days. At the same time, the temperature in it will drop by only 2-3 degrees. This is the most obvious and understandable advantage of having a heat accumulator in the home heating system. In fact, its capabilities are much wider. Indeed, in fact, it significantly increases the volume of coolant in the heating system circuit. At the same time, its indicators such as heat capacity and inertness also increase.
That is, the system warms up more slowly, absorbing more energy, but it also cools down for a very long time, maintaining the temperature in the house even when the boiler is not working.
Exists whole line situations in which the presence of a heat accumulator in the system significantly simplifies and reduces the cost of achieving the required results.
Fuel burns best when the boiler is operating in maximum power. But in spring and summer this power is clearly excessive. And the presence of a water tank will allow you to quickly heat the water in it to the desired temperature and stop the combustion process, saving fuel and time for servicing the boiler.
Solid fuel boilers have a minimum power during ignition; as the fuel burns, it reaches a maximum, and then drops again. This mode is not very useful for the operation of the heating system - the temperature of the coolant in it constantly fluctuates. The presence of a heat accumulator allows you to maintain the temperature in the system at an optimal level.
If the system has several sources of heating the coolant, and one of them is a solid fuel boiler, then connecting the others becomes very difficult. A coolant reservoir allows you to organize such connections easily and at low cost.
If it is necessary to organize hot water supply in the house, then you have to install an additional heat exchanger in the boiler or use a boiler indirect heating. All this negatively affects the operation of the heating system. And here large tank with hot water makes it easy to get out of the situation.
Thus, the TA is a decoupling unit between the heating circuit and the boiler, allowing minimal costs implement various additional functions.
To do this, you need to build on the following data:
- heating unit power;
- the time during which the coolant in the heat exchanger must warm up;
- the time for which the thermal power accumulated in the reservoir should be enough to cover the heat loss of the house.
For correct selection it is necessary to know the thermal power of the heater.
It is calculated using the formula:
Q = m × C × (T2 – T1),
- where m is the mass of the coolant (depending on the volume of the heat exchanger), kg;
- C – specific heat capacity of the coolant;
- T2 – T1 is the difference between the final and initial water temperatures. Usually it is taken equal to 40 degrees.
One ton of water, when cooled by 40 degrees, releases 46 kWh of heat.
If you want to switch the boiler to periodic operation, for example, only to night or day mode, then the power of the heating unit should be enough to heat the house for the remaining time.
Let's give an example. Suppose you use a solid fuel boiler that operates only in daytime within 10 hours. In this case, the heat loss of the house is 5 kW, then per day 5 × 24 = 120 kW*h of thermal power will be required to maintain the heating function. The TA will be used for 14 hours. This means that it should accumulate: 5 × 14 = 70 kWh of heat. If the coolant is water, then its weight should be 70: 46 = 1.52 tons. With a margin of 15% this will be 1.75 tons, then the volume of the heat exchanger should be approximately 1.75 cubic meters. m.
Do not forget that the boiler power should be sufficient to produce 120 kWh of energy in 10 hours of operation. That is, its power must be at least 120: 10 = 12 kW.
If the heater is used only for the safety of the heating system in case of an accident, then the reserve of thermal power in it should be enough for 1-2 days. That is, the power reserve must be at least 120 - 240 kWh. Then the volume of TA will be: 240: 46 = 5.25 cubic meters. m.
These are approximate calculations, but they allow you to get a rough idea of TA parameters.
There are simpler ways to calculate the volume of TA:
- Volume equal to area premises in meters multiplied by 4. For example, a house has an area of 120 square meters. m. Then the volume of the tank should be: 120 × 4 = 480 l.
- The boiler power is multiplied by 25. For example, the boiler has a power of 12 kW, then the volume of the tank will be 12 × 25 = 300 liters.
You can make a reservoir for heating the coolant yourself or purchase a ready-made one. Self-production is associated with the difficulties of taking into account the characteristics and features of future equipment. Not only the price of the issue will depend on this, but also the performance of the TA, as well as its durability.
The main operating parameters of heat accumulators are:
- Weight, volume and dimensions. The volume of the tank is selected according to the power of the boiler. But the larger its volume, the more economically the system as a whole will operate. A large TA will take longer to heat up, but the time between firing the boiler will also increase. If the tank is too large according to calculation and does not fit into the allocated room, then you can use several smaller containers.
- Pressure in the heating system. The thickness of the TA walls, as well as the shape of its bottom and lid, depend on this value. If the pressure in the system is no more than 3 bar, then the most common heat accumulators can be used. If operating pressure is within 4-8 bar, then you need to choose tanks with torispherical lids. Such equipment will cost more.
- The material from which the tank is made. Most often this is standard carbon steel coated with waterproof paint. But if possible, it is better to choose a tank from of stainless steel. It is more resistant to additives contained in the coolant and corrosion.
- Maximum fluid temperature.
- Availability of installation additional equipment: heating elements, built-in heat exchanger for connection to DHW system, additional heat exchangers for organizing connection to other sources of heating coolant.
How to install a heat storage tank
The most in a simple way The installation is a vertically located TA, into the walls of which there are 4 pipes embedded, two on each side. Each pair is spaced vertically. On one side, the upper pipe is connected to the supply line of the boiler unit, and on the other - to the supply branch heating system. Below, on the corresponding sides of the tank, there are pipes connected to the return lines of the boiler and the heating circuit.
Boiler return pipes and heating circuit equipped with circulation pumps.
After loading fuel into the boiler and achieving stable combustion, turn on the circulation pump, supplying water from the bottom of the heat exchanger to its heating zone. At the same time, in parallel, hot coolant used for heating the premises is supplied to the heating unit through the upper pipe.
In this case, active mixing of cold and hot water in the tank does not occur - this is prevented different densities water different temperatures.
After the fuel burns out, the tank is filled with water at the required temperature. After this, the circulation pump of the heating circuit is turned on, which pumps heated water through the system. Due to the fact that the coolant enters the system through the upper pipe, and the water used in the system and already cooled enters from below, mixing of layers of water of different temperatures does not occur, and the heat exchanger supplies water to the system for a long time required temperature.
Types of TA depending on design
Depending on the functional purpose, all heat accumulators are divided into the following types:
- Empty - with direct connection of circuits. In such a system, no heat exchangers are used, and the separation of cold and hot water is ensured only by the difference in their density. Homemade TAs usually have exactly this design.
- With built-in boiler. Inside the main tank there is an additional container intended for heating water in the DHW system.
- With internal heat exchanger. This model allows you to separate coolants in the circuits of the boiler and heating system. The separation of liquids is ensured by the walls of the heat exchanger.
What does the heating equipment market offer?
Our market has products from well-known foreign companies:
- Buderus (Germany) - produces universal TAs that can be used to work with solid fuel boilers of any other brands. The tanks are made of carbon steel and equipped with insulation from a layer of foam plastic 100 mm thick.
- Hajdu is a Hungarian product that is attractive due to its good price-quality ratio. The thickness of the insulation layer is also 100 mm.
- Lapesa is a Spanish company that produces heat accumulators not only for household, but also industrial purposes. For thermal insulation of tanks, polyurethane foam is used, which ensures extremely low heat loss.
- NIBE (Sweden) - produces models that allow the use of various coolant heating units (heat pump or solar collector). The thermal insulation of the tanks is a layer of polystyrene foam 80 mm thick.
- S-TANK is a Belarusian product. Is different high quality And affordable price. Can work with low quality water. It has anti-corrosion protection in the form of a layer of enamel.
- GOPPO are Russian heat accumulators for heating systems, designed for pressures of 3 and 6 bar. They have 30 mm thick polyethylene foam insulation.
Choosing a heating system for the heating system of a private home is a responsible matter. If the heating installation is carried out by a specialized company, then you don’t have to worry about the correct selection of heating equipment. If you decide to do this yourself, then try to take into account all the listed parameters and choose a tank with at least a small reserve of volume.
Thermal accumulator, also known as a heat accumulator, also known as a buffer tank, is gaining more and more popularity every year as one of important elements heating systems of a private house.
Moreover, in some European countries the use of solid fuel heating boilers without is generally prohibited, and the list of such countries is constantly growing. And in our country, the sales rate of heat accumulators for heating boilers shows a steady increase from year to year.
Some domestic producers launched the production of thermal batteries designed specifically for Russian conditions and climatic features our country. Let's try to figure out what the purpose of this type of equipment is, what its features are, and most importantly, what the installation of a heat accumulator will give to a specific owner of a private house, and how to choose exactly what is needed.
Thermal accumulator and its use with various types of heat sources
The principle of operation of a heat accumulator is very simple: its main task is to accumulate thermal energy, when there is a surplus in the heating system, and release this heat during periods of shortage, i.e. when the heat source is not working. This leads to the main conclusion - it is most effective to use heat accumulators with heat sources that have a pronounced periodic nature of operation.
These include the majority, which are very common both in Russia and abroad. And also rapidly gaining popularity, especially in the south. It is clear that solid fuel boilers heat water only during combustion, and solar collectors are useless at night.
But that's not all, even electric heating boilers in combination with heat accumulators can be more efficient. If the difference between daytime and nighttime electricity rates is significant, e.g. night rate less than the daytime is more than 2 times, you can make the heating system in the house in such a way that it works only at night, and during the day the house can be heated using the heat accumulated in the heat accumulator. By the way, taking into account the explosive growth of electricity tariffs, the economic feasibility of such a solution becomes relevant.
Another factor that determines the efficiency of using heat accumulators is that a heat accumulator can become a link that unites several heat sources at once. In other words, if necessary - for example, when the cost solar collectors will decrease even more, and efficiency will increase - you will be able to significant changes rebuild the heating system in your home so as to heat the premises to the maximum using cheap solar energy, but at the same time, when there is no sun, use a solid fuel boiler.
In this case, it becomes possible to fully accumulate all excess heat, and then release it as needed. In fact, the heat accumulator allows you to use various sources thermal energy with the current minimum cost and at the same time ensures system stability by switching between them. Of course, not every heat accumulator has this opportunity - you should choose the desired model in advance.
Thermal accumulator in a system with a solid fuel boiler
Currently, heat accumulators are most often used in heating systems with solid fuel boilers. Feature solid fuel boilers - optimal mode their functioning is related to complete combustion fuel, i.e. achieved when operating at maximum power. Otherwise, as a result incomplete combustion fuel, toxic gases are formed, the heat exchange surfaces inside the boiler become clogged, soot appears in the chimney, which leads to deterioration performance characteristics and even boiler failure, which is unsafe for the house and its inhabitants.
So, it is best when the boiler is running at full capacity. This mode is quite justified in cold weather, but for most of the year the house heating system simply does not need the excess amount of heat received - it will be too hot. If you don’t have a heat accumulator, the only option is to “heat the street”, i.e. open the windows. This is both expensive and ineffective.
Therefore, a buffer tank is built into the heating system - it takes away excess thermal energy, which otherwise would simply be lost aimlessly, so that it can later be used for its intended purpose, without wasting fuel on it!
Briefly, a heating system with a solid fuel boiler and a heat accumulator works like this. During operation, the solid fuel boiler not only supplies heated coolant to the heating system of the house, but also heats it in the heat accumulator tank. After the boiler stops working, the house begins to cool accordingly. At this moment, the air temperature or the coolant temperature sensor in the heating system sends a signal to turn on the circulation pump, which supplies the coolant accumulated in the heat accumulator tank to the heating system of the house.
When the air (coolant) temperature rises to the set value, the sensor turns off the pump and the heat supply stops. The temperature of the coolant in the tank decreases slightly, because part of the energy was transferred to the heating system. It should be noted that due to the good thermal insulation of the heat accumulator, the coolant, while inside the tank, itself cools very slowly. Cycles of turning the pump on and off continue until the temperature of the coolant in the heat accumulator remains higher than in the heating system. And the house will not cool down.
Experts have different assessments of the economic effect of installing a heat accumulator. This effect depends on many factors, some of which will be discussed below. On average, it ranges from 20%, i.e. Every 5th ruble is saved. Note that the heat accumulator is especially effective in the off-season, with its frequent temperature fluctuations.
And here comes another useful property of a heat accumulator - in addition to increasing the safety of your home and saving you money, it also gives you comfort. Firstly, with the appearance of a buffer tank in your home, you will have to load fuel into the boiler much less often. If you have calculated and installed everything correctly, if in your home good thermal insulation By using a heat accumulator, you can heat your solid fuel boiler not several times a day, but up to once every 2 days.
Secondly, the heat accumulator is able to smooth out “temperature jumps” associated with the cooling of the coolant in the heating system, because this system becomes more stable and inertial. Thirdly, it helps to simplify the maintenance of a solid fuel boiler and even increase its service life. Fourthly, using a heat accumulator you can additionally provide your home with hot water, but this opportunity Not available on all models.
How to choose the right heat accumulator
First, you have to calculate the volume of the heat accumulator. This is important because depends on volume dimensions buffer capacity. It should be remembered that you still need to find the “right” place in the house in order to first bring in a heat accumulator of considerable width and height through doorways, and then install it next to a solid fuel boiler, as is most often the case in practice. Of course accurate calculations can only be done by a specialist, because this requires taking into account many specific factors, but in any case you need to understand approximately what kind of buffer capacity you are buying.
The volume of the heat accumulator directly depends on the power of the solid fuel heating boiler. There are several preliminary calculation methods based on determining the ability of a solid fuel boiler to heat the required volume of working fluid to a temperature of at least 40°C during the combustion of one full load of fuel, i.e. in about 2-3 hours. It is believed that this achieves maximum boiler efficiency with maximum fuel economy.
But, as a rule, to begin with, you can use the following calculation method: 1 kW of solid fuel boiler power must correspond to at least 25 liters, but not more than 50 liters of the volume of the heat accumulator connected to it.
Thus, with power heating boiler, equal to 15 kW, the capacity of the heat accumulator must be at least: 15 * 25 = 375 liters. And no more than 15*50 = 750 liters. It is better to choose with a reserve, i.e. about 400-500 liters.
In general, manufacturers of thermal accumulators offer products of various volumes - from 40 to 10,000 liters. Attention! Heat accumulators with a capacity of more than 500 liters may not fit into the doorway of your home.
Which type of heat accumulator is right for you?
The type depends on your needs, i.e. depends on how exactly you want to use it. There are 4 conditional type thermal batteries:
- A simple body accumulator for connection to a single heat source;
- Buffer tank for simultaneous connection of several heat sources, for example, a solid fuel heating boiler and a solar collector. It differs from the previous type by the presence of a lower coil;
- The heat accumulator with a DHW coil is designed for both heating and the production of hot water in flow-through mode;
- A heat accumulator with an internal tank for hot water supply (tank-in-tank design) is used both for accumulating heat in a heating system and for preparing and storing hot water for domestic use.
Alexander Fedotov, Head of Sales Department
“The choice of a heat accumulator depends on the goals that the heating system is designed to solve. This could be heating the building or providing heating and hot water. In the first case, a conventional insulated tank can be used, in the second we are talking about a device with various built-in heat exchangers.
When choosing a heat accumulator, it is necessary to take into account the type of the main heat source and their quantity in the heat supply system. Power is also an important factor. thermal appliance and hourly heat consumption».
In addition, the heat accumulator can be additionally equipped with one or more units for autonomous heating of water when necessary.
The price of a heat accumulator depends on its volume, type, as well as additional options and, of course, from the manufacturer’s brand.
Making a heat accumulator with your own hands
The Internet is replete with various kinds of recommendations for craftsmen on how to make a heat accumulator on our own, assuring that there is nothing difficult about it. On the one hand, the abundance of these recommendations once again emphasizes the importance of heat accumulators in the heating system - useless things are not discussed. On the other hand, it makes a sane person think: when you have to make a choice between buying a heat accumulator from a certified manufacturer and paying a little more, or making it “in the garage”, but saving your money, you need to first think about the consequences.
What is a heat accumulator ✮Big choice heat accumulators on the website portal
Because even the greatest craftsman, constructing a heat accumulator from iron barrel, as is often recommended on various sites, must understand what such imaginary savings will lead to. Firstly, the temperature of the coolant inside the heat accumulator can be close to 100°C, and secondly, inside the system there is high blood pressure. No one can predict how a makeshift buffer tank will behave during operation. Whether it's worth putting your home at risk is an open question. Everyone makes their own choice.
The internal structure and operating principle of the heat accumulator for heating boilers is designed to ensure that the required coolant temperature is maintained for 5-10 hours after the main energy source is turned off. Storage tank installed in combination with solid fuel and electric boilers. Connection to a heat pump and solar collectors is possible.
What is buffer capacity
In fact, this is a tank with a built-in DHW coil and a thermal insulation casing. The purpose of the container is to accumulate excess thermal energy. After turning off the main source of heating of the coolant, the tank certain time replaces it.Correctly used operating principle of a buffer storage tank in a heating system reduces heating costs and makes heating the building more comfortable. To ensure the feasibility of connecting a tank, it is necessary to consider its structure and operating principle, as well as take into account the existing advantages and disadvantages.
Design and principle of operation
The heat storage tank is a regular metal barrel, With external thermal insulation. The simple design of the heat accumulator is nevertheless different high efficiency and indispensable for heating systems. The buffer tank in cross-section consists of several units:- Tank - made from sheet metal(enamel coated), stainless steel. Branch pipes extend from the tank for connection to the heating system and heat generator. The material of the tank largely determines the service life of the heat accumulator.
- Spiral heat exchanger- installed in models connected to heating systems with several types of coolants (heat pump, solar collectors). Made from stainless steel.
- Built-in coil for domestic hot water- some buffer tanks, in addition to maintaining the heating temperature of the coolant in the heating system, heat water for hot water supply.
The housing has an inspection window for servicing the tank, removing scale and debris, and repair work if necessary.
Purpose of heat accumulators
The basis of the operation of the buffer tank is due to the fact that excess thermal energy is accumulated, after which it is used to heat the building and hot water supply. A heat accumulator in a heating system is needed to maintain a comfortable temperature in a residential building after the main source of thermal energy is turned off.The purpose of installing a storage tank varies depending on the type of heat generator: 
The tasks and purposes of using heat accumulators are different. In some cases, installation of a tank is an indispensable condition of operation, in others it is just a desired requirement that ensures comfortable and economical heating building.
Pros and cons of buffer capacity
The first and obvious disadvantage: the high cost of the tank. Quality products, manufactured in the EU or in Russia, will cost from 25,000 to 300,000 rubles. Another disadvantage: the large dimensions of the product. It is often necessary to install tanks of 1000 liters or more, which take up a lot of space.Now about the benefits of connection. There are several of them:
- Opportunity uninterrupted operation solid fuel boilers- if a buffer tank is not installed in the heating system, the coolant begins to cool immediately after the firewood burns out. The drop in temperature is felt by a person after approximately 3 hours.
When a heat accumulator is connected, cooling will occur more slowly. The water in the heating system will remain hot for about 5-10 hours (depending on the volume of the heat accumulator). - Economical - excess thermal energy is accumulated and used when the coolant cools, which significantly reduces fuel costs.
- Safety - the operation of boilers with cast iron heat exchangers. After the tank, the water enters the boiler warm, which prevents damage to the core from rapid cooling.
- Additional functions- some tanks have a DHW coil. Simultaneous accumulation of the heated coolant and heating of hot water occurs. The installation can satisfy the needs for domestic hot water of residents of the house using single-circuit solid fuel or electric boilers, not intended to provide hot water supply.
Which heat accumulator to choose
It is better to entrust the selection of storage capacity to specialists. You will need to select a tank that is optimally suited for the type of used heating equipment. Selection of a heat accumulator for a solid fuel boiler and heat pump may vary. Leading manufacturers directly indicate in their operating instructions what type of heating system a particular buffer tank is intended for. When choosing, pay attention to several technical characteristics:
- Storage container material- a stainless steel tank is unreasonably expensive, especially considering that the battery receives coolant from the heating system, which is less aggressive than water in the hot water supply. Enameled coating using glass polymers is the optimal solution.
- Additional functions- it is possible to select a tank for various water consumers, connect heating systems using water as a coolant and special compounds(heat pump, solar collectors). Tanks that are capable of heating water simultaneously with the accumulation of thermal energy deserve special mention.
How to calculate buffer capacity
To select the required volume of a heat accumulator, you can go through three solutions. The first is associated with the use of special online calculators. You will need to enter the following parameters:- heated area;
- boiler power;
- time of autonomous temperature maintenance in the heating system after turning off the boiler.
To obtain exact value use the second method, using formulas to calculate the buffer capacity. During calculations, several values are calculated:
- battery accumulation time or water heating to a temperature of 80-90°C;
- battery life period;
- boiler power.
- Q = m × cp × (T2-T1)- according to calculations, it will be possible to calculate how long it will take to accumulate sufficient thermal energy and find out possible losses. Values:
- m - coolant flow;
- ср - specific heat capacity;
- T2 and T1 - the initial and final temperature of heating water in the tank.
- Calculations for solar collectors are carried out somewhat differently. The formula Va=Szh × (Vн/Sн) is used. In order not to go into technical details The following table can be used in calculations:
And lastly, the capacity of the buffer tanks is selected so that 30-50 liters of coolant per 1 kW of boiler energy.
For convenience in calculations, you can use the following table:
Definition minimum quantity of heat produced in kW is carried out using the tables attached below.
Calculations for electric boilers, subject to using a night tariff:
Minimum required power to maintain a buffer tank connected to a solid fuel boiler in working order:
Which company should I buy a buffer drive from?
After performing calculations and determining the desired technical characteristics, you can proceed to selecting heat accumulators by manufacturer. Not only European products are represented on the market. There are heat accumulators for heating boilers Russian production, the quality is not inferior to famous foreign equipment.To facilitate the selection of buffer capacity, below is a description of the most popular models among domestic consumers: 
From the presented list of heat accumulators, you can select equipment suitable for housing of any size, heated by an electric or solid fuel boiler, heat pump, with the possibility DHW heating and without it.
Immediately after connecting the buffer tank, fuel costs will decrease by 15-30%. More importantly, the boiler will no longer be subject to hydraulic shocks, and the heating of the coolant in the heating system will become more uniform. The storage tank occupies an integral place in modern heating systems.