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 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 profile pipes section 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 collector.
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.
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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 electric cable, and the outer one is 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 then drilled holes high speed tool. The bolts enter with an interference fit, and when they are clamped with nuts, they additionally seal the junction. Budget engineering solution- 3 bottles of sanitary silicone (actually 2.5 bottles were used).
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 provided high precision conjugation of 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 on 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 the best EC ( natural circulation if the electricity is turned off) and to reduce unnecessary mixing of the coolant at the moment when CO does not take heat away or takes little of it. Because the scheme of the heating system laid out at the beginning with TA is general, then the user sketched more detailed options container work.
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 top part 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, ended heating season and the heat accumulator has cooled down, but it has become cold, 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 begins 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 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.
For most, any heating system consists of three main parts:
- heating radiators
- Pipelines
- Heating appliance or boiler
However, modern systems can be equipped with many other useful devices, one of which is a heat accumulator. With its help, it is possible to accumulate the excess energy that is generated in the boiler and is spent completely in vain.
Most models are nothing more than equipped with several lower and upper nozzles. Heat sources are connected to the first, consumers are connected to the second. Inside it is a liquid that can be used for desired purposes. Making a heat accumulator with your own hands is not difficult - enough time, working materials with a tool and desire.
Introductory installation video
Principle of operation
Based on the working principle heat accumulator is the high heat capacity of water. It can be described as follows:
- connects to the top of the tank, into which hot water enters - the most heated coolant
- Below is a circulating pump that selects cold water and lets it through the heating system back to the boiler
- The liquid that has cooled down very quickly is replaced by a newly heated one.
When the boiler stops working, the water in the pipelines of the heating system begins to gradually cool down. Circulating, it enters the tank, in which it begins to squeeze out the hot coolant into the pipes. Thus, the heating of the premises will continue for a certain time period.
The functions that the heat accumulator performs
Modern heat storage devices are complex devices that perform more than one useful function:
- Capable of providing domestic hot water
- Stabilize indoor temperatures
- Allow to increase System efficiency heating to the maximum possible, reducing fuel costs
- Capable of combining more than one heat source into a common circuit and vice versa
- Accumulate excess energy generated by the boiler
Despite all positive features, which performs a heat accumulator in the heating system, it has two significant drawbacks:
- The water resource directly depends on the capacity installed tank, however, it remains bounded and has the fast property of ending. It will not be superfluous to have an additional heating system from outside
- From the first drawback, the second one gradually appears: more resource-intensive installations require a large free area for their placement, for example, a separate room in the form of a boiler room
Simple heat accumulator
The simplest heat accumulator with your own hands can be made based on the principle of operation of a thermos - due to its non-conductive heat walls, it does not allow the liquid to cool down over a long period of time.
For work it is necessary to prepare:
- Tank of the desired capacity (from 150 l)
- Thermal insulation material
- Scotch
- Heating elements or copper pipes
- concrete slab
First of all, you should think about what the tank itself will be. As a rule, use any available at hand metal barrel. Everyone determines its volume individually, but taking a capacity of less than 150 liters does not make practical sense.
The selected barrel must be put in order. It should be cleaned, dust and other debris removed from the inside, and areas where corrosion has begun to form should be treated.
Then a heater is prepared, which will wrap the barrel. He will be responsible for keeping the heat inside as long as possible. For homemade design mineral wool is perfect. Enveloping with outside container, it is necessary to wrap it well with tape. Additionally, the surface is covered with sheet metal or wrapped in foil.
In order for the water to be heated inside, you must select one of the options:
- Installation of electric heaters
- Installation of a coil
The first option is quite complicated and not safe, so it is abandoned. The coil can be built independently from a copper tube with a diameter of 2-3 cm and a length of about 8-15 m. A spiral is bent from it and placed inside.
In the manufactured model, the upper part of the barrel is the heat accumulator - it is necessary to let the outlet pipe out of it. Another branch pipe is installed from below - the inlet, through which cold water. They should be equipped with cranes.
A simple device is ready to use, but before that, a question related to fire safety. It is recommended to locate such an installation exclusively on concrete slab, if possible fenced off with walls.
How to connect
A person who has many times encountered the device of heating systems should easily make a heat accumulator with his own hands and make further connections. It should not be particularly difficult for a beginner to do this work.
In words, the connection scheme can be described as follows:
- In transit through the entire tank, a return pipeline must pass through the heat accumulator, at its ends a one and a half inch inlet and outlet must be provided
- First, the boiler return and the tank are connected to each other. Between them should be placed circulation pump, driving water from a barrel to a shut-off valve, expansion tank and heater
- The circulation pump and the shut-off valve are also mounted on the second side
- It is necessary to connect the supply pipeline by analogy with the previous one, but now heat pumps not installed
It should be noted that in this way the heat accumulator is connected to the heating system operating on the basis of only one boiler. If their number increases, the scheme will become much more complicated.
The container must be additionally equipped with a thermometer, pressure sensors inside and an explosion valve. Accumulating constantly heat, the barrel can overheat over time. To prevent an explosion, it is necessary to relieve excess pressure periodically.
Heat accumulator and different types of heating systems
You can install a heat accumulator in conjunction with various heating systems. Interacting with each of them, it provides a number of advantages and quickly pays for itself.
The most common heat accumulators installed together heating equipment solid fuel, which have a minimum amount of residues. Bringing the efficiency to the maximum possible, they heat up very quickly heating radiators which wear out soon. It is better to save a part of the generated energy and use it when the need really arises.
double night rate for electricity - a problem for owners of electric heating boilers. Thus, during the daytime, the heat accumulator will accumulate heat in itself at a more favorable cost, and at night it will give it to the heating system.
Similar settings are used in multi-loop systems, distributing water between circuits. If you install nozzles at different heights, you can take water with different temperatures.
Upgrade options
Looking at the simplest do-it-yourself heat accumulator, a person with an engineering education will probably think about options for upgrading it. You can do this in the following ways:
- Another heat exchanger is installed below, through which the energy received by the solar collector can be accumulated
- Can be divided inner space tank into several sections that communicate with each other so that the stratification of the liquid by temperature is more pronounced
- To spend money on thermal insulation or not - everyone decides for himself. But a few centimeters of polyurethane foam will significantly reduce heat loss.
- By increasing the number of nozzles, it will be possible to mount the unit to more complex heating systems with several circuits operating independently
- It is possible to make an additional heat exchanger in which drinking water will accumulate
Video - Heat accumulator in a house with a periodic firebox
Summing up
Absolutely everyone can collect heat accumulators with their own hands. For him, there is no need to buy expensive equipment, and the most simple model consists of components that good man always in the garage or pantry.
All those who do not trust homemade devices, can get acquainted with the rich selection of models in the markets. Their cost is more than acceptable, and the investment pays off quickly.
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 solid fuel boilers. We will talk about the heat accumulator for heating boilers (TA) on solid fuels. This is a really necessary device that allows you to balance the operation of the circuit, smooth out the temperature drops of the coolant, while also saving money. We note right away 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 does not make any 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 loads solid fuel into the boiler. It is a reservoir in which there is no air access. It is insulated and has enough large volume. There is always water in the heat accumulator for heating, it also circulates throughout the circuit. Of course, as a coolant can be antifreeze liquid, but still, because of its high cost, it is not used in circuits with TA.
In addition, there is no point in filling the heating system with a heat accumulator with antifreeze, since such tanks are placed in residential premises. And the essence of their application is to ensure that the temperature in the circuit is always stable, and, accordingly, the water in the system is warm. The use of a large heat accumulator for heating in country houses temporary residence is impractical, and a small reservoir is of little use. This is due to the principle of operation of the heat accumulator for the heating system.
- The TA is located between the boiler and the heating system. When the boiler heats up the coolant, it enters the TA;
- then the water flows through the pipes to the radiators;
- The return line returns to the TA, and then immediately to the boiler.
Although the heat accumulator for the heating system is a single vessel, due to its large sizes the direction of flow at the top and bottom is different.
In order for TA to perform its primary function of heat storage, these streams must be mixed. The difficulty lies in the fact that heat always rises, and the cold seeks to descend. It is necessary to create 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 has evened out in the entire tank, then it is considered fully charged.
After the boiler fired everything that was loaded into it, it stops working and 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 storage for heating is small, then its reserve will last for a very short time, while the heating time of the batteries increases, since the volume of the coolant in the circuit has become larger. Cons of using for temporary residences:
- the warm-up time increases;
- a 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 at least troublesome. Considering that the tank alone will be 300 liters. For the sake of several days a week, it is pointless to take such measures.
Additional circuits are built into the tank - these are metal spiral pipes. The liquid in the spiral does not have direct contact with the coolant in the heat accumulator for heating the house. These can be contours:
- low-temperature heating (warm floor).
Thus, even the most primitive single-circuit boiler or even a stove can become a universal heater. He will provide the whole house necessary heat and hot water simultaneously. Accordingly, the performance of the heater will be fully utilized.
AT production models, manufactured in working 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.
This heating is additional options and is not mandatory, consider this if you decide to make a heat accumulator for heating with your own hands.
Heat accumulator piping schemes
We dare to assume that if you are interested in this article, then most likely you decided to make a heat accumulator for heating and tie it yourself. You can come up with a lot of connection schemes, the main thing is that everything works. If you correctly understand the processes occurring in the circuit, then you can quite experiment. How you connect the HA to the boiler will affect the operation of the entire system. Let's first take a look at the most a simple circuit 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 TA and the boiler must pump a larger amount of coolant than the one that stands up to the tank. Only in this case will a sufficient retracting force be formed, which will take part of the heat from the supply. The disadvantage of such a 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.
TA piping scheme with a boiler heating circuit
The essence of the heating circuit is that the thermostat does not mix water from the TA until the boiler warms it up to the set level. When the boiler is warmed up, part of the supply goes to the TA, and the part is mixed with the 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 get warm faster.
This method of installing a heat accumulator in a heating system allows you to use the circuit in offline when the pump is not running. Please note that the diagram shows only the nodes for connecting the TA to the boiler. The circulation of the coolant to the radiators occurs in a different way, which also passes through the TA. The presence of two bypasses allows you to play it safe twice:
- the check valve is activated if the pump is stopped and the ball valve on the lower bypass is closed;
- in the event of a pump stop and breakdown check valve circulation is carried out through the lower bypass.
In principle, some simplifications can be made in such a construction. Given the fact that the check valve has a high flow resistance, it can be excluded from the circuit.
TA piping scheme without check valve for gravity system
In this case, when the light disappears, you will need to manually open the ball valve. It should be said that with such a wiring, the TA should be above the level of the radiators. If you do not plan that the system will work by gravity, then the piping of the heating system with a heat accumulator can be performed according to the scheme shown below.
Scheme of piping TA for a circuit with forced circulation
In TA, the correct movement of water is created, which allows ball after ball, starting from the top, to warm it up. Perhaps the question arises, what to do if there is no light? We talked about this in an article about . It will be more economical and more convenient. After all, gravity circuits are made of pipes large section, moreover, not always convenient slopes must be observed. If you calculate the price of pipes and fittings, weigh all the inconveniences of installation and compare it all with the price of a UPS, then the idea of \u200b\u200binstallation alternative source nutrition will become very attractive.
Calculation of the volume of the heat storage
The volume of the heat accumulator for heating
As we have already mentioned, it is not advisable to use a small volume TA, while too large tanks are also not always appropriate. So the question arose of how to calculate the required volume of TA. I really want to give a specific answer, but, unfortunately, it cannot be. 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 is 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 choose a tank based on two values:
- the area of the heated room;
- boiler power.
Methods for calculating the volume of TA: room area x 4 or boiler power x 25.
It is these two characteristics that are decisive. Various sources offer their own method of calculation, but in fact these two methods are closely related. Suppose we decide to calculate the volume of a heat accumulator for heating, starting from the area of \u200b\u200bthe room. To do this, you need to multiply the quadrature of the heated room by four. For example, if we have little house 100 square meters, you will need a tank of 400 liters. This volume will reduce the loading of the boiler up to two times a day.
Undoubtedly, and so it is pyrolysis boilers, in which fuel is laid twice a day, only in this case the principle of operation is slightly different:
- fuel ignites;
- the air supply is reduced;
- the smoldering process begins.
In this case, when the fuel flares up, the temperature in the circuit begins to rise rapidly, and then smoldering keeps the water warm. During this very smoldering, a lot of energy escapes 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. In it in literally words water starts to boil. If the pipes are made of polymers, then this is simply fatal for them.
In one of the articles about TA, it takes some of the heat and the tank can boil only after the tank is fully charged. That is, the possibility of boiling, with the right amount of TA, tends to zero.
Now let's try to calculate the volume of TA, based on the number of kilowatts in the heater. By the way, this indicator is calculated on the basis of the quadrature of the room. 1 kW is taken for 10 m. 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 TA. 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 is taking 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 case, as in any other, one must do without fanaticism. If you put a TA for two thousand liters, then the heater simply cannot cope with such a volume. Be objective.
Installing a water heat accumulator in the heating system solves many problems at once. With solid fuel boilers, there are generally many benefits: less often to heat and the temperature in the house is more even. This device also helps to make heating more economical, since the boiler works in its own optimal mode- with active burning of firewood. Another heat accumulator (TA) allows you to heat with electricity is not so expensive. it a good option save for those who have a nightly rate with a substantial price difference relative to the daytime rate. The only thing stopping high prices for heat storage tanks - hundreds of thousands. There are more cheap option- make a heat accumulator with your own hands. It will cost 20-50 thousand - depending on the volume and the selected material.
Materials, design and insulation
Homemade storage tanks for heating systems are usually made in the form of a cube. Everyone chooses sizes and proportions based on the available area. What is their disadvantage? Most of them are non-hermetic. No, they don't leak and feel very good.
In system closed type, a sealed container is desirable - so that there is no air in the coolant, it is possible to maintain a stable pressure. To achieve this in artisanal conditions is not at all easy, although it is possible.
With and without heat exchanger
There are two types of heat accumulators that are put into heating: with a heat exchanger inside connected to the boiler and without it. In the second case, it's just a container with nozzles. Such TAs are installed if the coolant in the system and the boiler is the same, and if the pressure in all parts of the system is the same. The third limitation is temperature. In heating systems of this type, the temperature inside the boiler and on consumers (radiators, underfloor heating and other devices) can be the same.
At first glance, a heat accumulator without a heat exchanger seems to be more advantageous: direct water heating is more efficient than indirect heating (through a heat exchanger). The costs are less - since the heat exchanger is made of a copper pipe or stainless steel and the length of the pipe is several tens of meters.
But, if you let the water from the boiler through the coil, the boiler heat exchanger will last longer. After all, a small volume will circulate in this circle. The salts dissolved in it will quickly settle, and since there are no new “receipts”, there will be no other deposits. Without a coil, all the coolant in the system will be pumped (including the one in the tank), so the sediment will be ten times more.
What length of pipe to take for a heat exchanger
In most cases, heat accumulators are made with heat exchangers. Use for this copper pipe coiled or cast iron radiators. With this, everything is clear. But how long should the pipe be or how many sections are in the radiator? This must be counted. The exact calculation is long and complicated, but approximately can be calculated as follows:
- According to experimental data, the radiator section has a heat transfer coefficient of about 500 W / sq. m * deg, inch copper pipe— 800 W/sq.m*deg.
- We also accept that the average temperature difference in the coolant is 10°C.
- To calculate the planned heat reserve, we divide it by the heat transfer coefficient of the material (pipe or radiator). We get the heat exchange area for this case in square meters.
- We are looking for in the data what is the surface area of the material you have chosen (for 1 meter of pipe or 1 section of radiators). To find the footage or number of sections, we divide the resulting heat transfer area by the surface area.
This is an approximate calculation. The data will be a little overestimated, but it's not bad. It is much worse if they are underestimated - the coolant in the heat exchanger will boil before the water in the TA tank heats up. Therefore, it is better to take with a margin.
To make it a little clearer, we calculate the length of the pipe and the number of sections, if it is necessary to transfer 25 kW of heat to the water in the TA. 25000 W / 800 W / sq.m * hail = 3.21 m2. In the case of an inch tube, about 40 m will be required.
For radiators, the calculation is similar: 25000 W / 500 W / sq.m * hail = 5 m2. This is about 20 battery sections.
Which is better - radiators or pipes? In terms of practicality, better radiators. If it suddenly turned out that the heat transfer made by the heat exchanger is insufficient, you can always add a couple of sections. It’s more difficult with a pipe - you won’t grow it. You will either have to take a longer piece, or be smart about something with the second circuit of the heat exchanger. True, there are still options - add fins (to increase the heat transfer area) or install a circulation pump that will create movement in the tank. This will increase heat transfer.
The pump is easier to install, but it will only work if there is power. So this option is not for all occasions. Unless you have an electric generator or other power source in case of power failure.
What materials are they made from
Independently capacity for heat storage in the heating system is made:
- From ordinary sheet steel 4 mm thick. Most a budget option. It is bad that such a tank rusts. But there are technologies and coatings that will allow this process to be prevented / slowed down (description just below).
- From sheet stainless steel from 2 mm thick. There is a problem with the welds. If welded under normal conditions, the alloying metals in the heated area (seams) burn out, so that the seams rust and leak. You can solve the problem by buying a TIG torch and cooking in an argon environment.
- From Eurocube. This is a large plastic container. It doesn't rust, it's sealed. That's just the temperature of the liquid in it should not exceed 72-73 ° C, otherwise it will "lead". In order not to overheat, you will have to increase the volume or reduce the "downtime" between the furnaces.
In general, they make a heat accumulator from large barrels. Under a small system, you can weld two or three two-hundred-liter barrels. This container can be placed in small house- up to 60-70 squares.
So that a container made of ordinary steel does not rust, it must be covered with a sealed composition from the inside. For these purposes, a thick film is used, which covers the pools. It is welded on the right size local. There are also rubber-like paints or mastics. Some of them are also used for sealing pools, but many are used in various industries. Both films and mastics / paints you need to find those whose temperature regime of use exceeds 100 ° C (or better - 110 ° C). Another option is heat-resistant glass enamel.
When it comes to heat exchangers, they are made from a variety of materials:
Home-made heat exchangers for heat accumulators are usually made in the form of a spiral. For these purposes, annealed copper or corrugated stainless pipe. It is not a problem to bend them, even with a small diameter. These two materials are in the lead. But corrugated pipe not very good in terms of heat dissipation. Let her more area surface, but the movement of the coolant along it is difficult. So this is not the best choice. Especially for boilers with low power.
Paired with powerful boilers and in storage tanks of large volumes (from a cube and more), cast-iron radiators performed well. This is a budget option, but it has serious drawbacks. The first is great inertia. Until the radiator itself heats up, there is no heat exchange with water. This increases the heating time of the TA. The second drawback is that cast iron rusts. Maybe not so fast, but still. To prevent rust particles from entering the system, place mud collectors at the outlet of the homemade buffer tank.
Warming
Since the main task is to save as much heat as possible, home-made heat accumulators must be insulated. The two most common materials for these purposes are foam. high density(not less than 350 gr/m³) and mineral wool. Mineral wool is better to take in mats, it is easier to work with it. In terms of thickness - they take 10 cm on the bottom and sides, the top can be insulated more carefully - 15 cm.
To make a self-made heat accumulator look more presentable, and in order to slightly improve heat saving, it can be covered with foil foam insulation on top of the thermal insulation, sheathed with plywood, OSB or other sheet material.
A little more difficult with the insulation of the lower part of the buffer tank. Filled with water, it will weigh very solidly, so that many materials will simply crumble, and there will be very little sense from them. There are two solutions:
- Use foam / gas as a heat-insulating layer concrete blocks, on top of which lay several layers of basalt cardboard. It turns out good thermal insulation.
- Make a tank on legs or weld a frame on which to put the container. In this case, you can use any of the heaters - it can be put on mounting foam.
To unusual materials, which were used to insulate heat accumulators, is cellular polycarbonate. It itself retains heat well, as it is used in the construction of greenhouses. It can be laid in several layers, bringing the thermal insulation almost to the ideal. In this case, the lining with foil insulation makes more sense: the heat will be reflected back to the tank.
Stiffeners or frame
Do-it-yourself heat accumulator is made more often from sheet metal. Its thickness is several millimeters. Even with a volume of 500-700 liters, such a solid capacity is obtained. When filled with water, the walls of the container swell to the sides - the water pressure is considerable.
These are the ties inside the heat accumulator - so that the walls are not squeezed out by water
So that the walls of the container do not sag, you can either weld stiffeners from the inside (as in the photo), or weld the frame from corners and metal strips, and then scald it with metal. When choosing the option with stiffeners, they must be welded along the long side (if any) with a distance of no more than 50 cm. Having welded the transverse strips on opposite sides cube, they are connected using metal strips or pins, welding them too with a not too big step.
Examples of homemade heat storage tanks for heating
TA for cheap heating with electricity
This heat storage tank was made for an electric boiler. With its help, heat is stored during the night tariff. The capacity turned out to be large, in order to speed up the process and have a certain power reserve in case of a decrease in the validity of the night tariff, three more heating elements of 2 kW each were embedded. They are connected by a "star" to a three-phase network.
According to materials:
- tank size - 1.5 * 1.5 * 0.75 m (capacity about 1.7 m³), sheet thickness - 4 mm (part of the sheet went 1.5 * 6 m);
- cast iron radiator - 7 sections;
- metal corner - welded around the perimeter of the upper part to fix the cover;
- rubber compressor on a self-adhesive basis - to seal the same cover;
- metal fittings - fittings with external thread, shut-off valves;
- welding electrodes.
The process of assembling the container itself is simple - you need to:
- Boil all seams, clean, coat with a primer.
- Make holes for the pipes, install and scald the fittings.
- Weld "ties" inside the tank.
Heating elements are installed at the bottom - to heat the coldest layer
So that the walls do not "inflate" - Drill the corners in increments of 15-20 cm. These are the holes for the screed screws. then - strapping from the corner.
- Welding areas (all) should be cleaned, primed, painted.
- Prime and paint all surfaces inside and out.
- Clean, coat with a primer twice and paint the cast-iron battery / heat exchanger.
- Connect the battery to the conclusions made under the heat exchanger, fix it in the tank.
- Glue a rubber seal around the perimeter of the tank lid. It is better to glue the whole piece - it will be more airtight.
The finished tank is installed on a layer of high density foam (10 cm), lined on the sides and top with a mat of mineral wool 10 cm thick. The insulation was glued to the walls. During operation, the tank and components began to rust heavily. Installed inside helped to slow down the process magnesium anode.
Homemade sealed stainless steel tank
In a heating system with a coal-fired boiler with a capacity of 56 kW (heated area 190 m²), collected a heat accumulator with a volume of 4 cubes. Both the power of the boiler and the dimensions of the tank are taken with a very large margin - the owner wants to heat in the cold no more than 1 time per day, with a slight minus - once every two to three days. With these parameters, he succeeds. It is supposed to supply a coolant with a temperature not higher than 50 ° C to the system, so that the radiators in the rooms are installed with a double margin (). They stand on each radiator so that it is possible to regulate the temperature in each room separately. For a self-made heat accumulator, sheet stainless steel 2 mm thick was used.
Of the design features: homemade heat exchanger. It is also made of sheet metal. It consists of two plates, between which strips of metal are welded. These strips are guides for the flow of coolant. They do not reach one of the edges a little, they are located so that the flow goes in a "snake".
So "guides" for the flow of coolant from the boiler are welded
The size of the heat exchanger turned out to be large. To prevent the structure from walking, the cover, in addition to being scalded, was pulled over the area with studs, the installation sites were scalded with overlays from the same stainless steel. To check the tightness, a pressure test of 3.5 atm was carried out. Everything is intact, no leaks.
It is unlikely that questions will arise regarding welding of the hull itself. The only thing that could be interesting is that they cooked it with ordinary welding inverter, but with a TIG torch (purchased from a specialized store). An argon tank was also bought, so they cooked stainless steel in an argon environment.
A corner was scalded along the upper edge, studs were welded to the corner. They will be covered with a rubber seal.
Since the capacity is large, even dense foam will not withstand it. Therefore, a stand made of steel corner is welded under it.
All this is installed in the boiler room. The tank was covered on all sides with mineral wool 15 cm thick, OSB was sheathed over the insulation and painted. AT ready-made everything looks good.
According to the results of operation. In frosts of -25 ° C, it is necessary to heat once a day. At -7°C or -10°C - once every two days. With even warmer - and even less often.
How to make a buffer tank from a eurocube
If you decide to make a heat accumulator from plastic container be sure to pay attention to the temperature characteristics. Since the temperature of the coolant can reach 90 ° C, this should be the temperature that the plastic can withstand for a long time. There are few such European cubes and they are expensive. In principle, you can navigate by price. If the container is expensive, it may be suitable. Polyethylene products are distinguished by high heat resistance low pressure(PE-HD). These containers are suitable for making a heat accumulator with your own hands.
It is easier to make a heat accumulator from an eurotank than from any other material. The container is ready, you just need to run the heat exchangers inside, cut through and insert functional devices and fittings. the main task- carefully cut holes - exactly under the fittings. Seal them with high-temperature sealants (non-acidic).
If it is necessary to install heating elements from a Eurocube in a heat accumulator tank, it is better to cut out part of the wall, cut a plate from thick sheet aluminum. Pull the plate to the wall with bolts with paronite gaskets, carefully smearing everything with the same sealant.
Warming:
- sides - foil isol 5 mm. foil inside + 50 mm. EPPS
- top - 2 layers 10 mm. folgoizola + 50 mm XPS
- from below only 10 mm. folgoizol - a cube was placed on it during installation.
- The seams are additionally foamed. So EPP is safe.
Feedback from operation:
“Yesterday it got warmer to +2, so in the morning, at 7-00, it was 85 degrees, in TA, at 16-00 78 degrees, about 23-00, before turning on the heating elements - 75. As a result, the heating elements worked very little! But that's not always the case, sometimes it gets colder. Weather, wind, etc. - everything affects.
Independent manufacture of a heat accumulator is within the power of every person who has the skills to work with elementary plumbing and household tools. To assemble such a unit, you do not have to buy any expensive parts and materials. Components for the simplest model can be found in the garage or pantry of any thrifty and economic person.
After studying the following guide, you will be able to make a heat accumulator yourself and connect it to the heating system.
The device and features of the heat accumulator
By its design, a typical one is a steel tank with nozzles at the top and bottom, which are at the same time the ends of a coil made of a copper tube. The lower branch pipes are connected to the heat source, the upper ones - to the heating system. Inside the installation is a liquid that the consumer can use to solve the problems he needs.
The principle of operation of the unit is based on the high heat capacity of water. In general, the mechanism of action of a heat accumulator can be described as follows:
- two pipes are cut into the side walls of the container. Through one, cold water enters the tank from the water supply or from tanks, through the second, the heated coolant is discharged to the heating radiators;
- the upper end of the coil installed in the tank is connected to the cold water pipe of the boiler, the lower end to the hot water pipe;
- circulating through the coil, hot water heats the liquid in the tank. After turning off the boiler, the water in heating pipes starts to cool down, but continues to circulate. When it enters the heat accumulator, the cool liquid pushes the hot coolant accumulated there into the heating system, due to which the heating of the premises continues for some time (depending on the storage capacity) even when the boiler is turned off.
Important! To ensure the movement of the coolant, the system is completed.
Prices for heat accumulators for heating systems
Heat accumulators for heating systems
Key functions of heat storage
The heat accumulator has many useful features, including:
- providing the user with hot water;
- normalization temperature regime in heated rooms;
- performance improvement useful action heating system with a simultaneous reduction in heating costs;
- the possibility of combining several heat sources into a single circuit;
- accumulation of excess energy that the boiler produces, etc.
With all its advantages, heat accumulators have only 2 disadvantages, namely:
- the resource of the accumulated warm liquid directly depends on the volume of the tank used, but under any circumstances it remains strictly limited and ends quite quickly, so it is necessary to think over the issue of arrangement additional system heating;
- larger drives require a lot of space to install, for example, a boiler room.
Assembly of a simple heat accumulator
The simplest thermal storage device works on the principle of a thermos. The walls of the installation practically do not conduct heat and allow the water to remain warm for a sufficiently long time.
To assemble such a unit, we need the following devices:
- tank. choose individually, according to your needs and possibilities. Objective minimum - 150 l;
- material for thermal insulation. Mineral wool is excellent;
- adhesive tape;
- copper tubes for the manufacture of a coil;
- concrete slab or formwork boards and mortar for pouring.
The heat accumulator can be assembled on the basis of an iron barrel. The volume, as already noted, is selected individually, but there is not much point in using a tank with a capacity of less than 150 liters.
First step
Preparing the barrel for further work. If this is an old container, we carefully clean it from various contaminants and clean out signs of corrosion.
Heat accumulator, pipes. 1 - heating system. 2 - upper coil. 3 - lower coil. 4 - TA cooling. 5 - security group. 6 - magnesium anode 
Heat accumulator, pipes on the other side. 1 - Wats thermometers. 2 - solid fuel boiler. 3 - thermal sensors for the controller of solar systems Second step
Wrapping the outer walls heat-insulating material. Mineral wool works well. The barrel wrapped in thermal insulation is additionally wrapped with adhesive tape in several layers.
Third step
Wrap the tank in foil. To fix the material, we also use adhesive tape. Sewing if desired isolated structure sheet metal.
Fourth step
We make a coil through which the coolant will be transported. For this we use copper tube 8-15 m long (depending on the volume of the selected barrel) and about 20-30 m in diameter. We bend the pipe into a spiral and place it inside the tank. The coil is connected to the boiler. In the future, this spiral will heat up and give off the received heat to the water in the tank.
Coil - heat exchanger 
Fifth step
We make nozzles in the side walls of the drive. Cold water will enter the tank through one pipe, hot water will come out through the other. We equip the branch pipes with taps to quickly shut off the water circulation.
sixth step
We install the thermal drive and connect it.
For a better understanding of the procedure for connecting a heat accumulator, we look at the diagram.
Important! The barrel can only be placed on a concrete slab. We buy a finished product or cast the base ourselves.
According to the considered method, the drive is connected to a heating system operating using 1 boiler. In case of application more heating units, the scheme becomes much more complicated. The system will have to be equipped with pressure and temperature sensors, explosive and safety valves etc. It is recommended to start assembling such a unit only if you have the appropriate skills and due experience.
The use of a heat accumulator in various heating systems
Thermal accumulators show themselves effectively when used in a wide variety of applications. different systems heating. At the same time, in each case, such a drive can significantly save on heating.
Most often, heat accumulators are equipped with solid fuel heating systems. Installation will help more economical consumption fuel and efficient heating and also prevent premature wear of heating radiators.
It will not be superfluous to have a thermal accumulator in the system, especially in regions with a double tariff for electricity. At night, when electricity is sold to the consumer at a more affordable cost, the battery will accumulate heat. During the day, it will be possible to turn off the boiler for a while and heat it with the help of a heat accumulator.
Accumulators are also used in multi-circuit heating systems Oh. Thanks to them, the distribution of the coolant between the circuits is ensured. The fittings can be installed on different height, which will allow you to get water heated to different temperatures.
A few words about modernization
If necessary, the heat accumulator assembled by us can be easily upgraded. There are several ways.
- We can install an additional heat exchanger from below, thanks to which the energy received will be accumulated. Actual for modern systems using solar energy for space heating.
- We can divide the internal space of the tank into several communicating sections, which will provide a more pronounced stratification of water by temperature. Relevant for multi-circuit systems.
- We can slightly increase the budget and insulate the walls of the tank instead of mineral wool. This material will further reduce heat loss.
- We can increase the number of pipes and connect the heat storage to more complex system heating, built on the basis of several independent circuits. Actual for heating systems serving big houses with high power boilers.
- We can install an additional heat exchanger to store water. It can be used for various household and household needs.
Now you own everything necessary knowledge for self assembly, installation, connection and modernization of the heat accumulator.
Successful work!
Video - Do-it-yourself heat accumulator
| Heat accumulator Jaspi (l) | Heating time (hours) at power | ||||||||
|---|---|---|---|---|---|---|---|---|---|
| 20 kW | 25 kW | 30 kW | 35 kW | 40 kW | 45 kW | 50 kW | 55 kW | 60 kW | |
| 500 | |||||||||
| 1000 | 2,3 | ||||||||
| 1200 | 2,8 | 2,2 | |||||||
| 1500 | 3,5 | 2,8 | 2,3 | ||||||
| 1800 | 3,4 | 2,8 | 2,4 | 2,1 | |||||
| 2000 | 3,1 | 2,7 | 2,3 | 2,1 | |||||
| 2400 | 3,2 | 2,8 | 2,5 | 2,2 | 2,0 | ||||
| 3000 | 3,5 | 3,1 | 2,8 | 2,5 | 2,3 | ||||
| 3500 | 3,3 | 3,0 | 2,7 | ||||||
| 4000 | 3,4 | 3,1 | |||||||
| 4500 | 3,5 |
