Heat accumulator for the system. Heat accumulator for heating boilers: parameters, installation features and where to buy heat accumulator for heating boilers

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

General information about heat accumulators

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

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

Operating principle

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

Functions of thermal accumulators

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

Where can a thermal accumulator be used?

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

Where is it undesirable to use heat accumulators?

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

Battery characteristics

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

Battery connection

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

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

Water systems

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

Solar systems

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

How to choose heat?

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

In the majority modern systems heating has an inherent flaw that makes it impossible effective organization heating using a periodic heating boiler. The problem lies not in the principle of fuel combustion, although not everything is smooth there either, but in the organization of heat transfer from the heat source - the combustion front of solid fuel into the air space living rooms houses or apartments. Heat accumulators are designed to compensate for losses caused by periodic operation of the boiler. To be precise, a heat accumulator is necessary for any intermittent heating boiler.

The device, proudly called a heat accumulator for heating boilers, is a tank of significant capacity, reaching in some cases up to 10 tons of water, with a system of internal heat exchangers. What should the use of a heat accumulator provide:

  • Safe accumulation of excess heat generated by the boiler into the coolant water flow;
  • Increase the duration of the heating-cooling cycle of the boiler installation, thereby simplifying its maintenance, freeing it from the need to start it at night or at inconvenient times;
  • Increase operating efficiency and increase the service life of heating boilers.

Interesting ! The primitive design of the heat accumulator for heating boilers allows you to make it yourself; you only need a water tank, pipes for connection, valve equipment and a welding machine.

In addition to a solid fuel heating boiler, systems also need to use a heat accumulator. electric boilers heating. In this case, the use of a heat accumulator is dictated by the artificial choice in favor of periodic heating, and only at night, when it is possible to use a more favorable preferential tariff.

The design of modern heating boilers is maximally optimized in terms of costs and production costs to please the manufacturer. A modern heating boiler is made of sheet steel with minimal costs for scarce and expensive copper and nickel, and operates in “potbelly stove” mode.

There is not even a hint of a heat accumulator in its design. Such a heating boiler is, in principle, unable to accumulate thermal energy. Compare a modern pellet or coal boiler with the old heavy designs of cast iron heating boilers, or even better, with the device of an ordinary village stone oven. In the latter case, the functions of the heat accumulator are performed most efficiently brickwork, directly absorbing heat from the flame and evenly transferring it into the air of the room within 10-12 hours.

Therefore, a modern heating boiler is ineffective without a heat accumulator. Solid fuel unit will be indispensable in work and will do without multi-ton heat accumulators if its device includes a system for automatically loading fuel into the firebox and subsequent cleaning of ash.

How does a heat accumulator work?

The purpose of the heat accumulator is to provide additional thermal energy to the water heating circuit after the heat generation by the heating boiler has decreased or stopped. For this purpose, in a huge container there is a large number of boiling water at a pressure of about 3 atm. A heat exchanger is soldered into the tank body, through which heat is “pumped” into the battery and returned to the heating system. Often, an additional heat exchanger is built into the tank to produce hot water for the needs of the kitchen and bathroom.

The principle of mixing flows of different temperatures

To quickly warm up the room, the heat accumulator is switched off from the circuit of movement of the heated coolant using a three-way valve. Only after the water flow in the pipes has warmed up above 60 o C is water from the heat accumulator reserve connected to the circuit. And while the boiler is running, heat goes in two directions: into the storage tank and into the heating radiators.

There are certain positive aspects to this principle:

  1. Rapid heating of the living space, and only after this the excess heat is discharged into the heat accumulator;
  2. The mixing principle provides efficient heat exchange;
  3. The water reserve in the heat accumulator is a strategic reserve for the boiler, thereby preventing its possible burnout if the water circulation in the heating plant is disrupted.

Important ! In such a scheme, any non-ferrous metals that produce an electrochemical couple with steel and aluminum should be excluded.

Ideally, the water circulating in the hot heat exchanger of the heating boiler should not mix with the coolant flowing throughout the heating system. Therefore, a different scheme is often used in heat accumulators - with hydraulic isolation and flow separation.

System with hydraulic isolation of thermal media

In this scheme, the heat accumulator plays the role of one of the elements of the heat supply circuit; it cannot be excluded from the flow. In fact, in the heat accumulator there is a constant transfer of heat from the dedicated “hot” circuit of the heating boiler and the rest of the water or coolant circulating in the heating system.

What does it give:

  • The highly loaded heat exchanger of a heating boiler requires the use of special water purified from impurities and air oxygen. Only such water guarantees a long service life of the heat exchanger tubes and seals. Stock required quantity prepared water is stored in an additional boiler.
  • By means of a special circuit of heated water from the heat accumulator tank, the temperature of the selected liquid can be easily adjusted, which simplifies the heating control system.

The disadvantages include the need for additional devices - two pumps: coolant circulation and power supply systems. Sometimes a couple of devices are used for backup - a voltage converter and an electric battery for a heating boiler. Otherwise, a power outage may lead to a serious accident in the primary circuit.

A more complex and improved scheme involves the use of two independent heat exchangers combined in one heat accumulator body. This is a more rational way to organize the operation of a heat accumulator with a high degree of redundancy. This is what we can recommend for those who want to make a heat accumulator for a heating boiler with their own hands.

Building a heat accumulator on your own

To manufacture a heat storage device, you need to determine the thermal power of the battery. There is a certain methodology for constructing an accumulating system. The amount of water in the battery is taken based on 30-40 liters of liquid for every 1000 W of boiler thermal power. In this case, for a house with 100 m2 of heated area, a capacity of 350-400 liters will be required. The best option There will be the use of a ready-made boiler tank, with sensors for water level, pressure and temperature.

If a system with admixture is chosen as the working scheme, which works properly even in the absence of special pumps, a three-position block valve will have to be additionally installed in the heating circuit.

Simpler schemes will require one or two heat exchangers to be installed in the tank

Important ! The Internet often recommends installing copper heat exchangers made of twisted copper pipe 15-17m long and with a “clearance” diameter of 15-20mm. The recommendation has dubious prospects, since copper and iron in contact with hot water intensively corrode.

It is better to use a heat exchanger made of the same material as the container. This guarantees normal quality weld seam when installing the heat exchanger. In addition, in the cavity of the heat accumulator it is better to use anodic protection with magnesium electrodes, similar to electric boilers hot water supply. The outer walls of the heat storage tank are sheathed thermal insulation mats or mineral wool.

Promising options for heat accumulators

One of interesting solutions Small-sized batteries have become available, using low-melting paraffins or silicone oils instead of water. Thanks to much more high heat capacity it became possible to use safe, small-sized storage systems for electric boilers in apartment heating systems. Instead of a 300-liter heavy tank, it is planned to use a two-section battery with a total volume of 50 liters of coolant, having a thermal reserve of 15 kWh.

For your information ! Most often, heat accumulators are used as backup source heat when growing vegetables in greenhouses, for quickly heating the room during a sudden cold snap or frost.

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 a fairly large volume. There is always water in the heat accumulator for heating, and it circulates throughout the entire circuit. Of course, non-freezing liquid can also be used as a coolant, but still, due to its high cost, it is not used in circuits with TA.

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

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

Although the heat accumulator for the heating system is a single vessel, due to its large 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;
  • higher installation costs.

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. 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 a small house of 100 square meters, then we 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 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.

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

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

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

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

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

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

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

Which boilers require a heat accumulator?

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

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

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

Thermal accumulator device

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

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

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

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

How does a heat accumulator work in a heating system?

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

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

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

Practical use

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

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

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

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

Heat accumulator and circulation pump

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

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

About the advantages and disadvantages

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

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

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


Heat accumulator for boiler

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

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

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

Why is it needed?

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

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

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

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

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

By design, the heat accumulator can be:

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

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

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

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

  • Q = m*C*(T2-T1),
  • m – mass, kg,
  • 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.

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


Heat accumulator, its structure and principle of operation.

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

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

I'll start answering these questions in order.

What is a heat accumulator?

To answer this question we need to give a definition. It sounds like this: a heat accumulator is a container in which a large volume of hot coolant accumulates. The outside of the container is covered with thermal insulation 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 solid fuel) always works in conjunction with a heat accumulator. The boiler quickly and non-stop transfers heat from the burned fuel to the heat accumulator, and it, in turn, slowly and 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 to be essentially a long-burning boiler. When the battery capacity is heated, the boiler constantly operates at full power, and this avoids the appearance of tarry condensate in the chimney and boiler.

How does a heat accumulator work?

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

The container has several pipes for connecting various equipment:

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

Materials of water-containing container.

Heat accumulator connection diagram.

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

From this diagram it can be seen that the TA is included in the heating system as a hydraulic separator (hydraulic arrow). I recommend reading a separate article dedicated to this useful device. Let me say briefly that this switching scheme eliminates the mutual influence of different circulation pumps and 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:

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

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

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

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



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

Installing a heat accumulator allows you to:

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

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

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

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

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

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

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

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

Why is it needed?

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

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

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

  • A solid fuel boiler only periodically heats the water. At the moment of ignition, the power is minimal, during active combustion the power increases to a maximum, after the bookmark burns out, it drops again and so the cycle repeats. As a result, the water temperature in the circuit constantly fluctuates over a fairly wide range;
  • To obtain hot water, it is necessary to install an additional heat exchanger or an external boiler with indirect heating, which significantly affects the operation of the heating circuit;
  • It is extremely difficult to connect additional heat sources to a heating system built around a solid fuel boiler. A complex decoupling will be required, preferably with automatic control;
  • A solid fuel boiler, even one that burns for a long time, constantly requires the user’s attention. 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;
  • C – specific heat capacity W/kg*K;
  • (T2-T1) – temperature delta, final and initial.

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

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 heat exchanger and the boiler so that hot water flows into top part TA, 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 a gravity heating system. 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 a separate element of the 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.

When the maximum water temperature in the heater and the target temperature in the radiators are reached, the overheating sensor installed in the boiler is triggered 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. Alternatively, they are available for sale ready-made assemblies for connecting heat accumulators - 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 the nominal pressure in the system with a reserve;
  • 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