Good day everyone! If you have landed on this page of my blog, then you are interested in at least 2 questions:
- What is a heat accumulator?
- How is a heat accumulator arranged?
I will start answering these questions in order.
What is a heat accumulator?
In order to answer this question, a definition needs to be given. It sounds like this, a heat accumulator is a container in which a large volume of hot coolant accumulates. Outside, the container is covered with thermal insulation made of mineral wool or foamed polyethylene.
Why do you need a heat accumulator?
You ask: “Why do we need this overgrown thermos?” Everything is very simple here, it allows you to optimally use the heat given off by the boiler. Paired with a heat accumulator, a powerful boiler always works (most often). The boiler quickly and non-stop transfers heat from the burned fuel to the heat accumulator, and it, in turn, slowly and in the right mode gives this heat to the heating system. The volume of the system is much smaller than the capacity of the battery. This allows you to "stretch" the heat from the fuel over time. It actually turns out. When the battery capacity is heated, the boiler constantly operates at full capacity, and this avoids the appearance of tarry condensate in the boiler.
How is a heat accumulator arranged?
As mentioned above, TA is a container in which hot water (or another) accumulates. To make it clear, look at the following figure: 
The tank has several nozzles for connecting various equipment:
- Thermal energy generator - boiler,.
- Plate heat exchanger for heating hot water.
- Various boiler equipment - safety group, expansion tank and so on.
Water container materials.
- Carbon steel of various grades with or without protective enamel or varnish on the inner surface is the cheapest and therefore the most common material.
- Stainless steel is the most durable material that does not corrode. Its main disadvantage is the high price.
- Fiberglass - collapsible heat accumulators are made from this "exotic" material, which are assembled directly on site. This method allows you to carry the TA along the narrowest stairs and assemble it exactly in the right place. If you're interested, watch the video to see what it looks like.
Heat accumulator connection diagram.
Now let's look at how the battery is included in the heating system:
From this diagram it can be seen that the TA is included in the heating system as a hydraulic separator (). I recommend reading a separate article dedicated to this useful device. I will say briefly that such a switching scheme excludes the mutual influence of different ones and allows you to provide the boiler with the required volume of coolant, which has a positive effect on the life of the heat exchanger.
Heat accumulator and hot water supply.
Another important issue is the device in the house of hot water. Here TA can also come to the rescue. Of course, it is impossible to use water directly from the heating system for sanitary needs. But there are at least two solutions here:
- Connection to the TA of a plate heat exchanger in which sanitary water will be heated is used on the simplest TA models.
- Purchase of a heat accumulator with a built-in DHW system - it can be implemented using either a separate heat exchanger (coil) or according to the “tank in tank” scheme.
You can, of course, still purchase separately, but I believe that this can only be done if you have the necessary space in your boiler room.
Summary.
A heat accumulator is another way to increase the time between fuel fillings in 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.
The internal structure and principle of operation of the heat accumulator for heating boilers is designed to ensure that the required temperature of the heat carrier is maintained for 5-10 hours after the main energy source is turned off. The storage tank is placed in a harness with solid fuel and electric boilers. Can be connected to a heat pump and solar collectors.
What is buffer capacity
In fact, this is a tank with a built-in DHW coil and a heat-insulating casing. The purpose of the tank is to accumulate excess thermal energy. After turning off the main source of heating of the coolant, the tank replaces it for a certain time.A correctly used principle of operation of a buffer tank in a heating system reduces heating costs and makes heating a building more comfortable. To make sure that it is expedient to connect a tank, it is necessary to consider its structure and principle of operation, as well as take into account the existing advantages and disadvantages.
Device and principle of operation
The heat storage tank is a conventional metal barrel with external thermal insulation. A simple heat storage device, however, is highly efficient and indispensable for heating systems. The buffer tank in the section consists of several nodes:- Tank - made of sheet metal (with enamel coating), stainless steel. Branch pipes depart from the tank for connection to the heating system and the 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 heat carriers (heat pump, solar collectors). Made from stainless steel.
- Built-in DHW coil- some buffer tanks, in addition to maintaining the heating temperature of the coolant in the heating system, heat water for hot water supply.
In the case there is an inspection window for servicing the tank, removing scale and debris, and carrying out repairs if necessary.
Purpose of heat accumulators
The basis of the operation of the buffer tank is due to the fact that the excess thermal energy is accumulated, after which it is used to heat the building and hot water. A heat accumulator in the 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 source: 
The tasks and purposes of using heat accumulators are different. In some cases, the installation of a tank is an indispensable condition for operation, in others it is only a desired requirement that ensures comfortable and economical heating of the building.
Pros and cons of buffer capacity
The first and obvious drawback: the high cost of the tank. High-quality products made in the EU or in Russia will cost from 25,000 to 300,000 rubles. Another disadvantage: the large dimensions of the product. Often it is necessary to install tanks of 1000 or more liters, which take up a lot of space.Now about the benefits of connecting. There are several of them:
- Possibility of uninterrupted operation of 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. A drop in temperature is felt by a person after about 3 hours.
Cooling down will be slower when a heat accumulator is connected. The water in the heating system will remain hot for about 5-10 hours (depending on the volume of the heat accumulator). - Profitability - excess thermal energy is accumulated and used when the coolant cools down, which significantly reduces fuel costs.
- Safety - the operation of boilers with cast-iron heat exchangers is facilitated. After the tank, the water enters the boiler warm, which eliminates damage to the core from rapid cooling.
- Additional functions- in the device of some tanks there is a DHW coil. There is a simultaneous accumulation of the heated coolant and heating of hot water. The installation can satisfy the needs for hot water supply of residents of the house using single-circuit solid fuel or electric boilers that are not designed to provide hot water.
Which heat accumulator to choose
It is better to entrust the selection of storage capacity to specialists. You will need to choose a tank that is optimally suited for the type of heating equipment used. The selection of a heat accumulator for a solid fuel boiler and a heat pump may differ. Leading manufacturers in the operating instructions directly indicate for which type of heating system this or that buffer tank is intended. When choosing, pay attention to several technical characteristics:
- Storage tank material- a stainless steel tank is unreasonably expensive, especially considering that the battery receives a coolant from the heating system, which is less aggressive than water in the hot water supply. Enamelled coating using glass polymers, 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 compositions (heat pump, solar collectors). Special mention should be made of tanks capable of heating water simultaneously with the accumulation of thermal energy.
How to calculate buffer capacity
To select the required volume of the heat accumulator, you can go three ways. The first is related to the use of special online calculators. You will need to enter the following parameters:- heated area;
- boiler power;
- time of autonomous maintenance of temperature in the heating system after the boiler is turned off.
To get the exact value, use the second method, according to the formulas for calculating the buffer capacity. During the calculations, several values are calculated:
- accumulator accumulation time or water heating up to the temperature of 80-90°С;
- battery life;
- boiler power.
- Q = m×cp×(T2-T1)- according to the 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 rate;
- cp - specific heat capacity;
- T2 and T1 - initial and final temperature of water heating in the tank.
- Calculations for solar collectors are carried out somewhat differently. The formula Va=Sl × (Vn/Sn) is used. In order not to go into technical details in the calculations, you can use the following table:
And lastly, the capacity of the buffer tanks is chosen so that 30-50 liters of coolant account for 1 kW of boiler energy.
For convenience in the calculations, you can use the following table:
The determination of the minimum amount of heat produced in kW is carried out using the tables attached below.
Calculations for electric boilers, subject to the use of the night tariff:
The minimum required power to maintain the buffer tank connected to the solid fuel boiler in working condition:
Which company to buy a buffer drive
After performing the calculations and determining the desired technical characteristics, you can proceed to the selection of heat accumulators by manufacturer. Not only European products are represented on the market. There are heat accumulators for Russian-made heating boilers, which are not inferior in quality to eminent foreign equipment.To facilitate the choice of buffer capacity, the following is a description of the most popular models for domestic consumers: 
From the presented list of heat accumulators, you can choose equipment suitable for housing of any size, heated by an electric or solid fuel boiler, heat pump, with and without the possibility of heating hot water.
Immediately after connecting the buffer tank, fuel costs will decrease by 15-30%. More importantly, the boiler will no longer be subjected 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.
How to organize the operation of an autonomous heating system in an economical mode? It is necessary to install a heat accumulator for heating boilers. As a result, efficiency will increase significantly while reducing fuel costs, and the overall costs of maintaining the property will also decrease.
We will talk about how the unit works, which allows you to collect and store the heat generated by the boiler. We describe in detail all the device options used in everyday life. In the article presented by us, the scope of application of heat accumulators and the rules of operation are given.
A heat accumulator is a buffer tank designed to accumulate excess heat generated during boiler operation. The saved resource is then used in the heating system during the period between scheduled loads of the main fuel resource.
Connecting the right battery allows you to reduce the cost of purchasing fuel (in some cases up to 50%) and makes it possible to switch to one load per day instead of two.
In addition to the function of accumulating the released heat, the buffer tank protects cast iron units from cracking in the event of an unexpected and sharp drop in the temperature of the working network water.
If the equipment is equipped with intelligent controllers and temperature sensors, and the heat supply from the storage tank to the heating system is automated, the heat transfer will increase significantly, and the number of fuel portions loaded into the combustion chamber of the heating unit will noticeably decrease.
Features of internal and external device
The heat accumulator is a tank in the form of a vertical cylinder, made of high strength black or stainless steel sheet.
On the inner surface of the device there is a layer of bakelite varnish. It protects the buffer tank from the aggressive influence of industrial hot water, weak salt solutions and concentrated acids. The outer side of the unit is powder coated, resistant to high thermal loads.
The volume of the tank varies from 100 to several thousand liters. The most capacious models have large linear dimensions that make it difficult to place equipment in the limited space of a home boiler room.
External thermal insulation is made of recycled polyurethane foam. The thickness of the protective layer is about 10 cm. The material has a specific complex weaving and an internal polyvinyl chloride coating.
This configuration prevents particles of dirt and small debris from accumulating between the fibers, provides a high level of water resistance and increases the overall wear resistance of the thermal insulator.
The heat insulator is not always included in the heat accumulator kit. Sometimes you have to buy it separately, and then mount it yourself on the unit
The surface of the protective layer is covered with a good quality leatherette cover. Due to these conditions, the water in the buffer tank cools much more slowly, and the overall heat loss of the entire system is significantly reduced.
The principle of operation of a heat-saving product
The heat accumulator functions according to the simplest scheme. From above, a pipe is supplied to the unit from a gas, solid fuel or electric boiler.
Hot water flows through it into the storage tank. Cooling down in the process, it goes down to the location of the circulation pump and with its help is fed back into the main passage to return to the boiler for the next heating.
Installing a heat accumulator prevents overheating of the coolant when the boiler is operating at full capacity and provides maximum heat transfer with economical fuel consumption. This reduces the load on the heating system and prolongs its service life.
A boiler of any type, regardless of the type of fuel resource, operates in steps, periodically turning on and off when the optimum temperature of the heating element is reached.
When work stops, the coolant enters the tank, and in the system it is replaced by a hot liquid that has not cooled down due to the presence of a heat accumulator. As a result, even after turning off the boiler and switching it to passive mode until the next fuel filling, the batteries remain hot for some time, and warm water comes out of the tap.
Varieties of heat-accumulating models
All buffer tanks perform almost the same function, but have some design features.
Manufacturers produce storage units of three types:
- hollow(not having internal heat exchangers);
- with one or two coils, providing more efficient operation of the equipment;
- with built-in boiler tanks small diameter, designed for the correct operation of an individual complex of hot water supply of a private house.
The heat accumulator is connected to the heating boiler and the communication wiring of the home heating system through threaded holes located in the outer casing of the unit.
How does a hollow aggregate work?
The device, which does not have either a coil or a built-in boiler inside, belongs to the simplest types of equipment and costs less than its more “fancy” counterparts.
It is connected to one or more (depending on the needs of the owners) sources of energy supply through central communications, and then through 1 ½ branch pipes it is diluted to consumption points.
It is planned to install an additional heating element operating on electric energy. The unit provides high-quality heating of residential real estate, minimizes the risk of overheating of the coolant and makes the operation of the system completely safe for the consumer.
When a residential building already has a separate hot water supply system and the owners do not plan to use solar thermal heat sources for space heating, it is advisable to save money and install a hollow buffer tank in which the entire useful area of the tank is given to the coolant, and not occupied by coils
Heat accumulator with one or two coils
A heat accumulator equipped with one or two heat exchangers (coils) is a progressive version of equipment for a wide range of applications. The upper coil in the design is responsible for the selection of thermal energy, and the lower one performs intensive heating of the buffer tank itself.
The presence of heat exchange units in the unit allows you to receive hot water for domestic needs around the clock, heat the tank from the solar collector, warm up the house paths and make the most efficient use of useful heat for any other convenient purposes.
Module with internal boiler
A heat accumulator with a built-in boiler is a progressive unit that not only accumulates excess heat generated by the boiler, but also supplies hot water to the tap for domestic purposes.
The internal boiler tank is made of stainless alloy steel and equipped with a magnesium anode. It reduces the level of water hardness and prevents the formation of scale on the walls.
The owners choose the appropriate volume of buffer capacity on their own, but experts say that there is no practical sense in buying a tank of less than 150 liters
This type of unit is connected to various energy sources and works correctly with both open and closed systems. Controls the temperature level of the operating coolant and protects the heating complex from boiler overheating.
Optimizes fuel consumption and reduces the number and frequency of downloads. It is compatible with solar collectors of any models and can function as a substitute for a hydraulic switch.
Scope of the heat accumulator
The heat accumulator collects and accumulates the energy generated by the heating system, and then helps to use it as rationally as possible for efficient heating and providing residential premises with hot water.
You need to purchase a device for accumulating excess heating resource only in specialized stores. The seller must provide the buyer with a product quality certificate and full instructions for use
It works with different types of equipment, but is most often used in combination with solar collectors, solid fuel and electric boilers.
Heat accumulator in solar system
A solar collector is a modern type of equipment that allows you to use free solar energy for everyday household needs. But without a heat accumulator, the equipment is not able to fully function, as it comes in unevenly. This is due to the change of time of day, weather conditions and seasonality.
A solar collector equipped with a heat accumulator is placed on the south side of the site. There, the device absorbs maximum energy and gives an effective return.
If the heating and water supply system is powered only from a single source of energy (the sun), at some point the residents may have serious problems with the supply of the resource and getting the usual elements of comfort.
A heat accumulator will help to avoid these unpleasant moments and make the most efficient use of clear, sunny days for energy storage. To work in the solar system, it uses the high heat capacity of water, 1 liter of which, cooling down by only a degree, releases thermal potential to heat 1 cubic meter of air by 4 degrees.
The solar collector and the heat accumulator make up a single system that makes it possible to use solar energy as the only source for heating a residential building
During peak solar activity, when it collects the maximum amount of light and energy production significantly exceeds consumption, the heat accumulator accumulates excess and supplies them to the heating system when the supply of the resource from the outside decreases or even stops, for example, at night.
The following article, which we recommend reading, will acquaint you with options and schemes for suburban property.
Buffer tank for solid fuel boiler
Cyclicity is a characteristic feature of work. At the first stage, firewood is loaded into the firebox and heating takes place for some time. The maximum power and the highest temperatures are observed at the peak of the bookmark combustion.
Then the heat transfer gradually decreases, and when the firewood finally burns out, the process of generating useful heating energy stops. All boilers, including long-burning appliances, operate according to this principle.
It is not possible to precisely configure the unit for the generation of thermal energy with reference to the level of consumption required at any given moment. This function is only available in more advanced equipment, such as modern gas or electric heating boilers.
Therefore, immediately at the moment of ignition and during reaching the actual power, and then in the process of cooling and the forced passive state of the equipment, thermal energy for full-fledged heating and hot water heating may simply not be enough.
But during peak operation and the active phase of fuel combustion, the amount of energy released will be excessive and most of it will literally “fly out into the pipe”. As a result, the resource will be spent irrationally, and the owners will have to constantly load new portions of fuel into the boiler.
In order for the house to be heated for a long time after turning off the solid fuel boiler, you need to purchase a large buffer tank. It will not be possible to accumulate a solid amount of a resource in a small reservoir, and its purchase will turn out to be a waste of money.
The installation of a heat accumulator solves this problem, which at the time of increased activity will accumulate heat in the reservoir. Then, when the firewood burns out and the boiler goes into passive standby mode, the buffer will transfer the collected energy, which will warm up and begin to circulate through the system, heating the room, bypassing the cooled device.
Reservoir for electrical system
Electric heating equipment is a rather expensive option, but it is also sometimes installed, and, as a rule, in combination with a solid fuel boiler.
Usually arranged where other sources of heat are not available due to objective reasons. Of course, with this method of heating, electricity bills seriously increase and home comfort costs the owners a lot of money.
The buffer tank must be installed directly next to the heating boiler. The equipment has solid dimensions and in a private house it will be necessary to allocate a special room for it. The system will fully pay off within 2-5 years
In order to reduce the cost of paying for electricity, it is advisable to use the equipment to the maximum during the period of preferential tariffication, that is, at night and on weekends.
But such an operating mode is possible only if there is a capacious buffer tank, where the energy generated during the grace period will accumulate, which can then be spent on heating and supplying hot water to residential premises.
DIY energy storage
The simplest model of a heat accumulator can be made with your own hands from a finished steel barrel. If this is not available, you will have to purchase several sheets of stainless steel with a thickness of at least 2 mm and weld from them a container of suitable size in the form of a vertical cylindrical tank.
It is not recommended to use the eurocube for the manufacture of a heat accumulator. It is designed for contact with a coolant having an operating temperature of up to + 70 ºС and simply cannot withstand hotter liquids.
DIY guide
To heat the water in the buffer, you will need to take a copper tube with a diameter of 2-3 centimeters and a length of 8 to 15 m (depending on the size of the tank). It will have to be bent into a spiral and placed inside the tank.
The battery in this model will be the upper part of the barrel. From there, you need to bring out the outlet pipe for the outlet of hot water, and make the same from below for the inlet of cold water. Equip each outlet with a tap to control the flow of liquid into the accumulation zone.
In an open heating system, a rectangular steel tank can be used as a buffer tank. In a closed system, this is excluded due to possible jumps in internal pressure.
At the next stage, it is necessary to check the container for leaks by filling it with water or lubricating the welds with kerosene. If there is no leakage, you can proceed to create an insulating layer that will allow the liquid inside the tank to remain hot for as long as possible.
How to insulate a homemade unit?
To begin with, the outer surface of the container must be thoroughly cleaned and degreased, and then primed and painted with heat-resistant powder paint, thus protecting it from corrosion.
Then wrap the tank with glass wool insulation or rolled basalt wool 6-8 mm thick and secure it with cords or ordinary tape. If desired, cover the surface with sheet metal or “wrap” the tank in foil.
Do not use extruded polystyrene foam or polystyrene for insulation. With the onset of cold weather, mice can start in these materials, looking for a warm place for their winter residence.
Holes for outlet pipes should be cut in the outer layer and the container should be connected to the boiler and heating system.
The buffer tank must be equipped with a thermometer, internal pressure sensors and an explosion valve. These elements allow you to control the potential overheating of the barrel and relieve excess pressure from time to time.
Accumulated resource consumption rate
It is impossible to accurately answer the question of how quickly the heat accumulated in the battery is consumed.
How long it will work on a resource collected in a buffer tank directly depends on such positions as:
- the actual volume of the storage capacity;
- the level of heat loss in the heated room;
- outdoor air temperature and the current season;
- set values of temperature sensors;
- useful area of the house that needs to be heated and supplied with hot water.
Heating of a private house in the passive state of the heating system can be carried out from several hours to several days. At this time, the boiler will “rest” from the load and its working resource will last for a longer amount of time.
Rules for safe operation
Do-it-yourself heat accumulators are subject to special safety requirements:
- The hot parts of the tank must not come into contact with or otherwise come into contact with flammable and explosive materials and substances. Ignoring this item can provoke the ignition of individual objects and a fire in the boiler room.
- A closed heating system assumes a constant high pressure of the coolant circulating inside. To ensure this point, the design of the tank must be completely tight. In addition, it is possible to strengthen its body with stiffeners, and equip the lid on the tank with durable rubber gaskets that are resistant to intense operating loads and elevated temperatures.
- If an additional heating element is present in the design, it is necessary to insulate its contacts very carefully, and the tank must be grounded. In this way, it will be possible to avoid electric shock and short circuit, which can disable the system.
Subject to these rules, the operation of a self-made heat accumulator will be completely safe and will not cause any problems or troubles to the owners.
Conclusions and useful video on the topic
Installing a heat accumulator for a home heating system is very beneficial and economically justified. The presence of this unit reduces the labor costs for kindling the boiler and allows you to bookmark the heating resource not twice a day, but only once.
The fuel consumption required for the correct operation of heating equipment is significantly reduced. The heat produced is used optimally and is not wasted. Heating and hot water costs are reduced, and living conditions become more convenient, comfortable and enjoyable.
Tell us about how the heat accumulator was installed on your boiler. Share the technological subtleties of the process and impressions about the efficiency of the device. Please leave comments in the block below, post photos, ask questions on controversial issues.
A heat accumulator, also known as a thermal accumulator, or a buffer tank, is gaining more and more popularity every year as one of the important elements of the heating system of a private house.
Moreover, in some European countries, the use of solid fuel heating boilers is generally prohibited, and the list of such countries is constantly updated. Yes, and in our country, the pace of sales of heat accumulators for heating boilers shows a steady increase from year to year.
Some domestic manufacturers have launched the production of thermal batteries designed specifically for Russian conditions and climatic features of our country. Let's try to figure out what the purpose of this type of equipment is, what are its features, and most importantly, what the installation of a heat accumulator will give to a particular owner of a private house, and how to choose exactly what is needed.
Heat accumulator and its use with heat sources of various types
The principle of operation of a heat accumulator is very simple: its main task is to accumulate thermal energy when there is an excess of it in the heating system, and to release this heat during its deficit, i.e. when the heat source is not working. This implies the main conclusion - the most efficient use of heat accumulators with heat sources, which have a pronounced periodic nature of work.
These include the majority, 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 combined with heat storage can be more efficient. If the difference between daytime and nighttime electricity tariffs is significant, for example, the nighttime tariff is more than 2 times less than the daytime one, you can make the heating system in the house so that it works only at night, and heat the house during the day due to 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 decision becomes relevant.
Another factor determining the efficiency of using heat accumulators is that a heat accumulator can become a link that combines several heat sources at once. In other words, if necessary - for example, when the cost of solar collectors will decrease even more, and the efficiency will increase - you can, without significant changes, rebuild the heating system in your house so that you can heat the premises to the maximum due to cheap solar energy, but at the same time, when the sun no, use a solid fuel boiler.
In this case, it becomes possible to fully accumulate all the excess heat, and then give it away as needed. In fact, the heat accumulator allows the use of various sources of thermal energy at the current minimum cost and at the same time ensures the stability of the system by switching between them. Of course, not every heat accumulator has such an opportunity - you should select the desired model in advance.
Heat accumulator in a system with a solid fuel boiler
Currently, heat accumulators are most often used in heating systems with solid fuel boilers. A characteristic feature of solid fuel boilers is that the optimal mode of their operation is associated with complete combustion of fuel, i.e. achieved when operating at maximum power. Otherwise, as a result of incomplete combustion of fuel, toxic gases are formed, heat exchange surfaces inside the boiler are clogged, soot appears in the chimney, which leads to deterioration in performance and even failure of the boiler, which is unsafe for the house and its inhabitants.
So, it is best when the boiler is working "at full". Such a regime is quite justified in the cold, but for most of the year the heating system of the house simply does not need the amount of heat received in excess - it will be too hot. If you do not have a heat accumulator, the only way out is to "heat the street", i.e. open vents. This is both expensive and inefficient.
Therefore, a buffer tank is built into the heating system - it takes away excess thermal energy, which otherwise would simply be lost aimlessly, in order to subsequently use them for their intended purpose, without spending fuel on this!
In short, a heating system with a solid fuel boiler and a heat accumulator works like this. During operation, the solid fuel boiler not only supplies the heated coolant to the heating system of the house, but also heats it up in the heat accumulator tank. After the boiler stops working, the house, accordingly, begins to cool. At this moment, the air temperature or the heat carrier temperature sensor in the heating system sends a signal to turn on the circulation pump, which ensures the supply of the heat carrier accumulated in the heat accumulator tank to the house heating system.
When the temperature of the air (heat carrier) rises to the set value, the sensor turns off the pump and the heat supply stops. At the same time, 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, being inside the tank, cools down very slowly by itself. Cycles of turning on and off the pump 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 estimate the economic effect of installing a heat accumulator in different ways. 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 the heat accumulator - in addition to improving the security of the house and saving you money, it also gives you comfort. Firstly, with the advent of a buffer tank in your house, you will have to load fuel into the boiler much less often. If you have calculated and installed everything correctly, if your house has good thermal insulation, using a heat accumulator, you will be able to heat your solid fuel boiler not several times a day, but up to 1 time in 2 days.
Secondly, the heat accumulator is able to smooth out the "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, with the help of a heat accumulator, you can additionally provide your home with hot water, but this possibility is not provided in all models.
How to choose the right heat accumulator
First you have to calculate the volume of the heat accumulator. This is important because the overall dimensions of the buffer tank depend on the volume. 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 the doorways, and then install it next to the solid fuel boiler, as is most often the case in practice. Of course, only a specialist can make accurate calculations, because. this requires taking into account many specific factors, but in any case, you need to understand 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 in this way the maximum efficiency of the boiler is achieved with maximum fuel economy.
But, as a rule, for starters, you can use the following calculation method: 1 kW of power of a solid fuel boiler 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 a heating boiler power of 15 kW, the capacity of the heat accumulator must be at least: 15 * 25 \u003d 375 liters. And no more than 15 * 50 = 750 liters. It is better to choose with a margin, i.e. about 400-500 liters.
In general, manufacturers of heat 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 through the doorway of your house.
What type of heat storage is right for you
The type depends on your needs, ie. how exactly you want to use it. There are 4 conditional types of heat accumulators:
- A simple body accumulator, for connection to a single heat source;
- Buffer tank for the simultaneous connection of several heat sources, such as a solid fuel heating boiler and a solar collector. It differs from the previous type by the presence of a lower coil;
- A heat accumulator with a DHW coil is designed both for heating and for the production of hot water in flow mode;
- A heat accumulator with an internal tank for hot water supply (tank-in-tank design) is used both for heat storage in the heating system and for the preparation and accumulation of hot water that is used in everyday life.
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 case 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. Important factors are also the power of the heating device and the hourly heat consumption.».
In addition, the heat accumulator can be additionally equipped with one or more heaters for autonomous water heating, when necessary.
The price of a heat accumulator depends on its volume, type, as well as on additional options and, of course, on 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 their 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 ✮Large selection of heat accumulators on the website portal
Because even the greatest folk craftsman, when constructing a heat accumulator from an 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, there is an increased pressure inside the system. No one can predict how the handicraft buffer tank will behave during operation. Whether it is worth putting your home at risk is an open question. Everyone makes a choice.
How to improve the efficiency of a solid fuel boiler? Reduce the cost of purchasing energy? Reduce the number of furnaces (the number of approaches for throwing / loading coal or firewood into the boiler) per day? The answer is to install a buffer capacity, the so-called. heat accumulator, and "charge" it with energy from the heat generator - heat the water in reserve. And then, as needed, spend it for the heating system. You can buy a heat accumulator ready-made - from the factory, or try to save money and make it yourself. We will talk about the successful implementation of homemade products in this article.
- How to make a heat accumulator for a solid fuel boiler from a tank.
- How to connect a buffer tank to a heating system with a solid fuel boiler.
- Experience in the use of a heat accumulator.
Homemade heat accumulator for a TT boiler from a tank from a fire engine
Sjava FORUMHOUSE user
We have expensive gas. Therefore, in addition to a 24 kW gas boiler, which I now heat the house with, I bought a solid fuel (TT) boiler with a capacity of 20 kW. Heated area - 135 sq. m. From it: 110 sq. m I heat with underfloor heating and another 25 sq. m radiators. TT boiler, after installation, paid off in almost a season. I believe that the installation of a heat accumulator (TA) will increase the efficiency of the heating system. In the off-season, with TA, I generally think of switching only to heating with a TT boiler and using a gas boiler as a reserve and for quick heating of the coolant. Then I plan to save even more - I will install a solar collector, and in the summer I will dump “free” energy from it into a buffer tank.
First, let's show the scheme of the heating system Sjava.
The circuit, after the commissioning of the heat accumulator, has undergone a slight change, which we will discuss below.
Now let's show how the user made a heat accumulator. The basis of the TA is a used barrel - a 1.5 cubic meter tank from a fire truck.
It is easier and cheaper to make a heat accumulator from a ready-made container than to cook a steel tank from zero on your own.
Important. If barrels / tanks from fuel and lubricants are used as a home-made container for TA(fuel and lubricants), then, in order to avoid accidents, because vapors retain flammability for many years, extra care must be taken when working especially welding.
V757V FORUMHOUSE user
I once got into a conversation with a fuel trucker, and he told me how they cook tanks at the oil depot. Pour water into the tank to the eyeballs. They put a raft with a burning candle at the top and slowly drain the water. Water gradually flows out, and everything that can burn quietly burns out as the container is emptied.
From the tank, measuring 2 (height) x 1.35 x 0.75 m, they cut off everything superfluous.
Because the heat accumulator is placed vertically so that the tank filled with water does not swell, the user made “ties” from a pipe with a diameter of 22 mm.
"Cables" are reinforced with washers, although, according to sjava, it's too much.
Pipe ties can be used as sleeves for installing thermometers or temperature sensors in TA.
The tank hatch is used as an inspection hatch and for inserting heating elements (tubular electric heaters) with built-in magnesium anodes 3 pcs. 2 or 3 kW.
The water in the TA will also be heated by electricity at a cheaper nightly rate.
Hatch details.
The bottom of the TA tank is reinforced with profile pipes with a section of 4x4 cm.
Welded pipes for tying TA with a boiler and a heating system.
The top of the TA is also reinforced, otherwise it will bulge from the pressure when the water is heated.
Welded homemade manifold.
Couplings for heating elements are welded into the hatch.
The base for the TA is made of plywood and timber with a section of 100x100 mm with slots so that the pipes welded to the bottom of the tank do not press on the base.
The base for the heat accumulator is insulated with foam plastic.
In parallel with the manufacture of TA for the heating system, components came. thermostatic valve.
A circulation pump with taps, which will then be replaced with "American" ones.
Heating elements with magnesium anodes.
.
Magnesium anodes protect TA metal from rust.
Cover seal Sjava made according to the original technology. First, the user sealed the cap with sealant. I screwed the cover on 16 bolts, but when testing the TA with a pressure of 2 bar, water began to ooze from under the roof. The do-it-yourselfer did not cut the rubber gasket. Too complicated, and there are no guarantees of tightness. Eventually Sjava made a silicone gasket.
Step by step instructions for making it:
- The place where the gasket is placed is painted, because silicone in contact with unprotected ferrous metal activates corrosion.
- With the help of hot glue, beads are glued around the circumference of the lid.
The inner collar is a piece of electrical cable, and the outer one is a packing tape.
Then the user, having previously calculated the volume of the gasket, took the cylinders with silicone, and filled the entire space between the shoulders, gradually smoothing the silicone with an old credit card.
The thickness of the gasket is 8 mm.
Sjava FORUMHOUSE user
I immediately warn you that silicone dries out for about a week. I removed the collars on the fourth day. When everything dried up, an elastic silicone mass was obtained. I drilled the holes later, at high speeds of the tool. The bolts enter with an interference fit, and when they are clamped with nuts, they additionally seal the junction. The budget of the engineering solution is 3 cylinders of sanitary silicone (2.5 cylinders actually took).
Rings (2 pcs.) for the lid are homemade, welded from two metal corners rolled around the circumference.
The assembly - tank-ring-lid-ring is first assembled on tacks and only then all the holes are drilled. This ensured high precision of mating parts.
Scheme of the neck of the heat accumulator cover.
So, a homemade heat accumulator is ready. Then the user proceeded to routine work - tying the HE with the boiler and connecting it to the heating system. And here's what happened.
Knots close up.
Schemes for connecting a buffer tank to a solid fuel boiler and a heating system
Topic Sjava aroused keen interest on the portal. Users began to discuss the scheme for connecting the TA to the boiler.
ZelGen FORUMHOUSE user
Looked at the scheme of the heating system. The question arose, why is the entrance to the TA located just above the middle of the tank? If the inlet is made from the top of the buffer tank, then the hot carrier from the TT boiler is immediately fed to the outlet, without mixing with the colder carrier in the TA. The container is gradually filled with hot coolant from top to bottom. And so, until the upper half of the TA warms up, which is approximately 500 liters, the hot carrier in the TA is mixed and cooled.
According to sjava, the input to the heat accumulator is made in such a way for better EC (natural circulation if the electricity is turned off) and to reduce unnecessary mixing of the coolant at a time when CO does not take heat or takes it away a little. Because the scheme of the heating system with TA laid out at the beginning is general, then the user sketched out more detailed options for the operation of the tank.
Advantages - if the light is turned off, then natural circulation works. The disadvantage is the inertia of the system.
An analogue of the first scheme, but if all thermal heads are closed in the heating system, then the upper part of the heat accumulator is the warmest and there is no intensive mixing. When the thermal heads are opened, the coolant is immediately supplied to the CO. This reduces inertia. There is also an EC.
The heat accumulator is placed parallel to the system. Advantages - fast supply of coolant, but natural circulation in the system is in doubt. Possible boiling of the coolant.
Development of the third scheme with closed thermal heads. The disadvantage is that there is a complete mixing of all layers of water in the heat accumulator, which is bad for natural circulation if there is no electricity.
This made it possible to change the connection scheme of the heat accumulator from parallel to serial. For example, the heating season has ended and the heat accumulator has cooled down, but it has become colder, then, without heating the heat accumulator, you can quickly heat the house with a boiler.
Operation of a heat accumulator with a solid fuel boiler: personal experience
The user's conclusions from the operation of the TA are interesting:
- The boiler enters the mode + 80-85 ° C in 10-15 minutes. As a result, there is no soot and smoke. After two or three furnaces, tar deposits and streaks from last year's condensate burned out. After two weeks of work in the optimal temperature regime, the boiler furnace became almost like new, now there is only ashes inside. Firewood in the boiler burns out completely, with maximum heat release, and the heat generator is not driven into smoldering mode.
If the coolant temperature is lowered below 60-65 °C, then conditions are created in the TTK combustion chamber for the appearance of condensate (harmful acids).
- A solid fuel boiler in tandem with a heat accumulator operates with maximum efficiency both in winter and in the off-season, at outdoor temperatures of 0 ° C - -5-10 ° C. Excess heat from a well-fired boiler is simply discharged into a heat accumulator, and then, as necessary, the coolant is consumed.
- Water in TA is "charged" in layers:
- Top - + 80 °C.
- Middle - + 65-70 °C.
- Lower part - +50-60 °C.
- When the boiler is not working, the water temperature in the lower part does not fall below the return temperature, and the top is gradually discharged. According to observations Sjava TA is “charged” to the above temperatures in 3-4 hours. If there is no frost on the street, and most of the underfloor heating branches are closed, then the heat removal to the CO decreases and the TA charge occurs faster.
- The thermostat is installed at the outlet of the flow from the heat accumulator to the heating system. At his command, if the water temperature drops to + 40 ° C, the gas boiler is turned on for reheating.
Sjava FORUMHOUSE user
With the blower fully open in the boiler, the temperature at the supply max + 90 °C. Usually the temperature is kept + 80-85 °C. The heat accumulator is charged in layers. First, the temperature of the top rises, and then the middle and bottom. For example, when the top is heated to the supply temperature, the temperature of the coolant in the middle of the heat exchanger starts to rise (the top remains 80-85 °C), then the temperature rises downwards.
The heat accumulator should be well insulated and placed vertically, because. hot water is concentrated at the top of the TA.
Questions arise, but is such a volume of TA enough for a house in cold weather? According to calculations Sjava for his cottage, at a temperature of -25 ° C, a heat accumulator of 5000 liters is needed. To quickly heat such a volume of water, a boiler with a capacity of 50-100 kW is required. But it is spent on an expensive system.
