Heating of premises with the help of boilers on wood and electricity. Combined boilers firewood electricity: device and principle of operation Heating stoves combined firewood electricity

Solid fuel boilers, despite all the obvious advantages and disadvantages, have another hidden aspect that you have to pay attention to over time. Systems with manual boot mode do not work in maintenance mode. The fuel in the furnace has run out - the boiler stops working, respectively, the coolant begins to cool. This problem is well known to private sector residents and property owners. country houses.

Constantly throwing up coal or firewood, filling the furnace, is not always possible, and stopping the boiler in winter is fraught with sharp decline temperatures in all residential areas.

The best option to prevent such a situation would be a heating system in which an electric boiler is tied to a solid fuel boiler.

Functions of an electric boiler in a heating system with a solid fuel unit

Connecting an electric boiler to the system in conjunction with a solid fuel heater is a fairly common engineering solution. This option eliminates the possibility of cooling the heating system, prevents hypothermia of the main heating unit and maintains a comfortable temperature in the house. An electric boiler often acts as a backup heating device, the task of which is to equalize the temperature of the coolant in the heating system.

The layout of solid fuel and electric boilers when used together in the heating system

The operation of solid fuel boilers needs periodic human control - all models of such units need to be loaded with fuel.

On a note: for traditional boilers, the number of downloads can reach up to 2-6 times per day. The situation is different with pyrolysis boilers and units. long burning. Here, frequent human intervention is not required. One load of fuel is enough for 12-24 hours of boiler operation, and for some models - for 48 hours of operation.

The main task for the owner of the house with the heating turned on is to prevent the boiler and heating system from cooling down. An electric boiler paired with a solid fuel boiler successfully solve this problem. Let us consider in detail the combination of a solid fuel boiler with a heating device powered by electricity.

The working one is as follows: a solid fuel unit with a power of 50 kW must be combined with an electric boiler with a power of 28 kW. The operation of the electric heater is periodic. The unit must be on the pickup - be ready to turn on immediately after the main equipment stops. The electric boiler starts when the fuel in the solid fuel boiler runs out and the temperature of the coolant in the system drops to 50 0 C. In this case, there must be a water tank for the hot water supply system in the circuit, which in this case acts as a heat accumulator.

The main elements of the circuit that consume the power of autonomous heating boilers are:

• heating radiators - require 30 kW;
• heating system "warm floor" - up to 15 kW;
• storage capacity for the DHW system - an average of 300 liters.

Attention! Automation for adjusting the switching of circuits in this situation - a bunch of units is not required.

An electric boiler, working together with a heat accumulator, is a group that prevents a coolant with a temperature that has fallen below a critical level of 50 0 C from entering the main heating unit.

The pump installed in the system periodically drives the coolant through the pipeline, signaling the temperature in the heating circuit. When the temperature of the coolant drops to a critical level, the electric boiler equipped with heating elements is put into operation, taking on the task of supplying heat to the house. A thermostat and a three-way valve provide temperature control of the hot water tank. When the water temperature in the DHW system circuit drops, the coolant is launched into the heating coil hot water. A properly connected electric boiler, competent piping with a solid fuel boiler, will make your system completely controllable.

In the described design of the heating system, all heating equipment, including the pipeline, is reliably protected from defrosting when the main heating device is stopped and does not cause interruptions in residential heating and hot water supply.

Combined heating boilers

Another, less expensive option is the installation of a combined unit, which is a solid fuel boiler and an electric unit at the same time.

Such devices use solid fuel and electricity to heat the coolant, being designed for the interchangeability of these energy carriers during operation. A feature of such units is the installation of electric heating elements in the tank of a solid fuel boiler - heating elements provide the necessary heating of the coolant passing through the heat exchanger. Idea to combine electrical device with a solid fuel unit is not new, but it became possible to establish the production of the corresponding heating equipment only after the appearance of combined automation devices and new generation materials.

The principle of operation of combined heating mechanisms is that, while combustion chamber free from the main type of fuel (wood, coal, peat, etc.), the main work on heating the coolant for. Thanks to the installed control sensors, the equipment independently reacts to changes temperature regime, turning on and off as needed.

In practice, it looks like this: the fuel filling has already completely burned out, respectively, the boiler went out. The boiler water accordingly begins to lose its temperature. Solid fuel is being replaced by electric heating. Now the heating mechanism works like a regular electric boiler until the firebox is filled with the next batch of firewood or coal.

After the main unit reaches the optimal operating mode, the control unit turns off the electric heating elements, the heating again works on solid fuel.

Advantages and disadvantages of combined heating equipment

Despite the high cost, combined boilers have undeniable advantages. These include not only complete control over the state of the entire home heating system, but also a number of others:

• the device does an excellent job of heating rooms with low energy consumption;
• combined boilers are environmentally friendly heating units;
• lack of condensate, since the first heating of the device is carried out in both modes - main and auxiliary;
• the entire heating complex is constantly in working condition, which is important in the event of a long absence of the owners of the house.

However, this technique also has disadvantages.

A significant disadvantage for combined heaters is energy dependence. In the absence of voltage in the network, the system loses its efficiency and versatility.

Important! When installing equipment, it is necessary to take into account the potential of home electrical wiring, which may not be designed for the power of the equipment being installed. The presence of low-amperage circuit breakers will lead to constant power outages in the house. Before installation, make sure that the power consumption limit allocated for you is able to satisfy the operation of the heating equipment.

Unlike traditional solid fuel appliances, in which the efficiency reaches 70-80%, combined products have a lower coefficient - by about 3-5%.

How to achieve joint operation of electric and solid fuel units

If you are faced with a choice of which individual heating option to prefer - a solid fuel boiler, an autonomous electrical unit or a combination of these two devices, the latter option has advantages. To install the circuit, you will need a connection diagram for both units, similar to a gas-solid fuel heating complex. Properly done piping of equipment is a guarantee of the efficiency and safety of operation of this equipment.

The proposed video describes in detail how and in what way to connect heating devices on a solid together with electric heating elements

What to pay attention to when installing:

• both devices must have a reasonable power ratio, a coal-fired or wood-burning heater is the main source of heat, so its power must be twice the power of an electric boiler;
• both units are connected in parallel, which gives the independence of the operation of one from the other;
• the solid fuel unit is the main one and is connected to a large circuit, while the electric boiler is responsible for the temperature in a small one;
• the main heating unit is equipped with a three-way valve;
• to save energy and ensure the safety of heating, the installation of a heat accumulator is required;
• each heater is set to a certain heating temperature - for solid fuel equipment, the operating temperature should be 60-70 0 C, while on the electric unit the temperature is set to 40-50 0 C, since due to the presence it will cool down more slowly, and the electric boiler will start with a delay in time.

Eventually

In each case, the homeowner himself decides how to organize an autonomous heating system. Suggested technical solutions will allow not only to eliminate the unpleasant consequences of the attenuation of the main heater during a severe winter, but also give some energy savings.

The efficiency of operation of solid fuel units and electric boilers in pairs has been proven by practice - the interaction of these devices gives greater comfort and guarantees the reliability of heat supply.

All in our time, you can increasingly see universal combined for a private house heating boilers operating simultaneously on two types of fuel. Combining firewood and electricity together is a pretty smart solution, such a boiler is quite reliable, compact and practical. And if there is a power outage or a lack of fuel, you will not experience discomfort from the cold or lack of hot water during the cold period.

Modern heating boilers use solid fuel, combining it with both gas and electricity, which is more relevant for consumers. When purchasing a heating boiler that works both on wood and on electricity, several problems are solved at once:

1. For heating, two alternative energy carriers relative to natural gas are used at once.
2. The issue of cooling down the premises is being solved in the case when everything in the firebox has completely burned out, and a new portion of fuel has not yet been loaded.
3. Makes more comfortable water heating, since you no longer need to get up in the middle of the night and go to the boiler room to load fuel.

Combined electric wood heating boilers of the latest generation with a large firebox are made in such a way that switching to electric heating occurs automatically when the water temperature in the boiler drops below a certain mark. Naturally, the reverse transition to the combustion of solid fuel occurs with the help of external actions.

The design of the electric wood boiler

Externally, the combined TT firewood boiler is in no way different from a conventional solid fuel unit. In fact, this is the same wood-burning heating boiler, the only difference is that it has a heater installed in the heat exchanger. Another important difference from the standard configuration is the presence of a water jacket.

One of the walls of such a boiler is made by cold stamping and has a complex configuration. Heating elements are installed between the walls of the shirt and there is a special contact hole to which the electrical wiring contacts are connected.

This type of heater device is similar in design to a standard solid fuel boiler, which consists of the following main elements:

• firebox (combustion chamber), a place for loading solid fuel;
• outside it is washed by the coolant, which is inside the water jacket;
• a water-tube or fire-tube type heat exchanger, where the combustion products transfer most of the heat to water before being released into the chimney;
• at the bottom of the firebox there is a grate, and under it there is an ash chamber;
• firebox and ash pan in front equipped with doors;
• to adjust the intensity of combustion, there is a mechanical draft regulator or a fan-blower (if there is no manual control of the air damper).

Household combined heating boilers are distinguished by the design of a water jacket, where a place is provided for the installation of a block of tubular electric heaters - heating elements. Their contacts are brought out and connected to the control panel with the help of an electric cable, and the heating part is immersed in the coolant.

How a combi boiler works

The principle of operation of a solid fuel heater, in which electric heaters are installed, is as follows:

1. Kindling and heating of the boiler are carried out in the usual mode. When burning solid fuel, the temperature of the coolant is maintained using a mechanical thermostat or a fan together with a sensor, and the heating elements are turned off at this time.
2. After the contents of the fuel chamber burn out, the temperature of the coolant in the system gradually drops to a certain value, reaching which, at the signal of the temperature sensor, the heating element (one or more) is turned on. At this point, the boiler starts to work on electricity.
3. After the next portion of firewood or coal is loaded, the water in the system begins to be heated from the side of the combustion chamber, electrical part automatically turns off until the temperature of the coolant drops to a certain value.
4. Electrical equipment is auxiliary.
5. The heater control unit is used to maintain a certain water temperature, based on the readings of the air or water sensor.

Continuous heating of water is provided by switching from one mode to another, which provides comfortable conditions in a private house.

Advantages of universal boilers

After installing a combined wood-electricity heating boiler, you will receive the following bonuses:

1. Versatility. You will have the choice of which of the two fuels to use and when.
2. Due to the built-in heating elements, the coolant will maintain the set temperature even after the fuel has burned out in the loading chamber. This will maintain a comfortable temperature inside the room, and in case of your long absence, it will prevent pipes and radiators from freezing.
3. Comfort. Maintaining the temperature with electricity will be of great service, helping to get rid of the problem of night trips to re-load fuel into the combustion chamber.
4. If electricity is metered according to a multi-tariff scheme, then in addition to convenience, you can also save on the night operation of heating elements.
5. Thoughtful device. The heat is distributed in such a way that the loss of thermal energy is close to a minimum, thanks to which the boilers are quite efficient.
6. Long period of operation. If properly maintained, such a boiler can serve you for at least 20 years.
7. Autonomy. You do not need to constantly monitor the process - for this the unit is equipped with automation. Especially in the case of operation from electricity, the operation mode using a heating element is limited to an uninterrupted supply of electricity.
8. You can find models with pre-built pipes in order to be able to connect the "warm floor" system.

Heating combined boilers, which work both on wood and on electricity, cope with their task even in low-power mode.

Disadvantages of combined units

The electric heaters of the universal boiler are intended only to maintain the temperature of the water in the system, complete replacement they will not be able to burn solid fuels. The reason for this is the low power of the block of heating elements, which are mounted by manufacturers on solid fuel boilers. This feature, unfortunately, is one of the serious drawbacks of combined boilers for heating a private house on wood.

Heating a private house with a combined boiler that runs on both electricity and firewood has other disadvantages.

1. The useful volume is taken away from the loading chamber by the block of heaters, which significantly affects the burning time from one load.
2. The operation of the device directly depends on the stability of the power supply.
3. The cost of combi boilers is much higher compared to classic solid fuel boilers.
4. The efficiency during operation of the heating elements drops by 2-5% due to the air flow that passes through the cooled furnace. The reason for this is the constant draft in the chimney, it forces the air out of the rooms to leave through the chimney and thereby cools the water jacket of the heater.

Do not forget one more important detail. As in the case of a classic solid fuel boiler, a combined heating boiler of the wood and electricity type must be connected to the water heating through a three-way valve, as shown in the diagram below. A small circulation circuit is necessary to protect the furnace from the negative effects of condensate during kindling.

In order to prevent the walls of the combustion chamber from being covered with condensate when the temperature drops, the solid fuel boiler must be connected according to the standard scheme with a three-way valve:

In the event that the power of the heating elements is not enough to heat the coolant to a temperature of + 55 ° C or more, then condensate will never appear in the furnace of the combined boiler during ignition, and the unit with a three-way mixing valve will not be needed. But as practice shows, a small circulation circuit, nevertheless, is necessary, at least in the event of a power outage or a breakdown of one of the heating elements.

How to choose a boiler "firewood electricity"?

Manufacturers offer combined heating boilers that run on both wood and electricity, which differ in performance, power and equipment. When buying this equipment, you need to pay attention to the following points:

1. Power - this parameter depends on what type of fuel is used. It is necessary to determine in advance the main type of fuel for the purchased device.
2. The dimensions of the combustion chamber - its volume will show how often it will be necessary to load fuel.
3. Noiselessness - installation of a special valve will ensure quiet operation of the unit.
4. Number of circuits - some models heat water only with the help of heating elements.
5. The most economical models are those in which the coil is mounted in the combustion chamber.
6. Heat exchanger. It is made from both steel and cast iron. Cast iron ones are not so susceptible to corrosion, they give off heat longer, although they heat up longer, they also have a rather serious weight, and with sudden temperature changes they can crack. Steel has less resistance to corrosion and oxidation, but they are lighter and more resistant to temperature extremes.
7. Grids. The material of manufacture can be very different. They can be both cast iron and ceramics. Cast iron has a higher heat resistance and is suitable for the combustion of any solid fuel. Honeycomb cast iron grate with ceramic coating is suitable for bulk materials, the combustion of which consumes more oxygen.
8. The weight and dimensions of the unit. Due to the large dimensions, it may be necessary to reinforce the surface area where the unit will be installed with a concrete screed.

When choosing a boiler for heating a house, you need to correctly calculate the power of the device based on the parameters of the area of ​​\u200b\u200bthe room. This will indicate how much fuel consumption will be required. If the area of ​​the house does not exceed 80 m2, then you do not need to buy a boiler whose capacity is designed to heat a house with an area of ​​400 m2. This may lead to overspending of budgetary funds for the purchase of the unit, and for its subsequent operation.

A combined wood and electricity boiler is perhaps one of the most successful solutions for heating a summer house or a small private house. In a cottage that has 2-3 floors, heating elements will only save the system from freezing. Combined boilers will help out if it is not possible to use a constant and reliable source of energy. In addition, these boilers will save you quite a lot of money if you use more expensive fuel as a fallback.

For the installation of such a boiler, it is better to use the services of a specialist who works in this profile. He will advise the most suitable device model for you and without unnecessary problems it will be installed based on the requirements of safety rules and technology requirements.

Our units run on solid fuel and are designed for wood heating of cottages and low-rise private country houses. The area of ​​premises heated by firewood is from 80 to 320 squares.

The design of the wood burning apparatus allows additional use of electric heating of the coolant. To do this, a threaded sleeve for the heating element is provided on the rear or side wall of the housing.

This is a useful option for wood-fired boilers, which allows you to avoid temperature fluctuations in the heating system between fires. When water is used as the heating medium, the electric heating will protect the system from freezing in the event of prolonged downtime during the cold season.

A tubular electric heater with a control panel will automate the process of controlling the unit and expand the functionality of a simple wood-fired boiler.

Heating element installation

The heating element is not included in the sale of the wood-burning boiler, but is an option that must be purchased separately. For combi wood boilers of low power up to 18 kW, a tubular electric heater of 1-3 kW is suitable; for devices of 18-32 kW, a heater with a rated power of 6 to 9 kW is recommended.

The control panel with a thermostat automatically maintains the temperature within the specified range by turning the electric heater on and off. The block is equipped with protection against boiling and a light signal.

Heating elements with a power of 1 to 3 kW are single-phase and are powered by a household electrical network with a voltage of 220 V, and heating elements with a power of 6 to 9 kW are three-phase and are powered by a network with a voltage of 220/380 V. When installing the unit, connect the ground.

Until quite recently, the owners of private houses did not even think about what fuel the heat source would operate on to heat their homes. The question was considered rhetorical, and the answer was clear - it was natural gas. However, the time has come non-standard solutions, since energy carriers are constantly becoming more expensive, and which of them will be beneficial for use tomorrow is unknown. That is why there has been a massive interest in such heating installations as an electric wood-burning boiler.

What are the advantages of combined installations?

The solution is really non-standard, and it makes it possible to kill several birds with one stone:

• find an alternative to natural gas for heating;
• play it safe for the future, having in stock as many as two additional energy carriers;
• at the same time, ensure comfortable operation of the heater, eliminating the need to fiddle with firewood in the furnace at night.

Arranging heating with electric wood-burning boilers is also relevant in new buildings, for the same reasons. At the same time, it is possible to recall the old-fashioned methods and mount a gravity-flow heating system in order to maximize independence from external influences. Although the convection system is not the best solution in terms of efficiency, it is affordable at the cost of installation. And in the event of a power outage, you can always safely switch to firewood.

Unit design features

Externally, the device of an electric wood-burning boiler practically does not differ from a traditional solid fuel heat generator. Only in one place, where under the cladding and thermal insulation is located water jacket unit, there is a special hole from which you can see the contacts for connecting electrical wires. In reality, the combined plant has a solid fuel combustion chamber, an ash chamber with a damper through which the combustion air passes, and a grate.

Household combined boilers for wood and electricity can be equipped with both a water-tube heat exchanger and fire tubes. Some models are supplied with hobs located at the top of the combustion chamber. That is, these are full-fledged solid fuel installations with an efficiency of 75-85%. But they have one design feature: one of the furnace walls, which is the inner lining of the water jacket, has a complex profile made using cold stamping. Thanks to this profile, one or more heating elements are placed in the space between the inner and outer skin of the jacket. This special case the scheme according to which electric wood-burning heating boilers are made, heating elements can be built into the boiler tank in other ways.

When for some reason the boiler cannot operate on the main fuel - wood, it automatically switches to electricity and vice versa, when the furnace is ignited, the electric heaters are turned off.

Description of the boiler

The heating elements are controlled by an electric unit, and the intensity of solid fuel combustion is regulated by an air supply thermostat, opening the ash chamber damper at a certain angle by a chain. That is, the control functions of the electric and solid fuel parts of the heater are separated. If air is forced into the furnace by a fan, then both parts are controlled by automation for a wood-burning boiler. In the first case, the algorithm of work is as follows:

After connecting the heat generator to the network, the electric heater is switched on. The temperature of the coolant is set on the control panel and the heating element starts to heat the water in automatic mode. It is better to set the temperature 10-15 ºС below the working one.

At this time, fuel is loaded into the combustion chamber and it is ignited. From this point on, the heating of the coolant occurs jointly, unless the electric heaters are forcibly turned off.

Having reached the water temperature set on the remote control, the heating elements turn off and the heat carrier is heated by firewood to the operating temperature. The intensity of combustion is controlled by a thermostat with a chain drive, and as soon as the water reaches the operating temperature, it shuts off the air supply.

When the combined boiler burns out its main fuel and there is no new load, the coolant will begin to cool down and at a certain moment the sensor of the electrical unit will work and it will turn on the heaters, which will maintain the temperature of the water until the next laying of firewood.

The algorithm for working with an air supply fan and a single electronic unit is similar to that described above, only the process of setting up the equipment is simplified. In this case, the energy independence of the solid fuel part of the unit is lost.

Due to their design and principle of operation, electric wood heating boilers for a private house acquire some advantages that are not characteristic of conventional solid fuel units:

1. Condensation does not occur on the inner walls of the furnace due to flow from the return pipeline cold water, since the boiler tank is constantly heated by a heating element.
2. As a result, the building heating system can be connected directly to the heat source, without organizing a small circuit and mixing unit with three way valve.
3. Theoretically, the efficiency of a combined water heater increases to 97-99% when the electric heating is on and the main firebox is not operating.

At the same time, the versatility of the unit does not eliminate the shortcomings inherent in both types of heaters separately. This is inertia, which is expressed in the impossibility of immediately stopping the heating of the coolant when the maximum temperature is reached.

Another drawback is the relatively low power of the electrical part, which will not be significantly increased by a water jacket device, it is impossible to build many electric heaters into it. For this reason, the power electric heaters equal to the power of a wood-burning combustion chamber in the range of 6-25 kW. If a higher rate is required, then the electricity will only serve as heating and will be able to maintain the temperature of the coolant at a certain level.

Conclusion

The use of universal installations of electricity - solid fuel for heating a small private house is enough rational decision, giving a lot of advantages over a separate system. Yes, and the issue of cost plays a role, at the price of a combined heater, buy separately solid fuel and electric boilers heating will fail.

The large-scale construction of suburban real estate has led to the rapid development of the heating systems market. Owners of private and country houses increasingly prefer modern systems autonomous heating, refusing gas water heaters. Often this is due to the high cost of natural resources or the inability to connect gas to the house. Universal combined boilers are gradually replacing gas units.

Combined boilers are designs that are able to work on various types fuel. Versatility of these units lies also in the fact that they can be used absolutely in any area, they do not require special conditions. Plus, combined boilers can be used without worrying about a weak gas supply or electricity fluctuations. In case of problems, you can easily switch to another fuel source. Combined equipment can operate on diesel and solid fuels, gas and electricity.

The device of combined boilers

Types of combined boilers

Depending on the combination of fuel types, Various types combined boilers:

• diesel fuel and natural gas;
• diesel, natural gas and solid fuels (usually wood is used);
• diesel, natural gas and electricity;
• diesel, solid fuel, gas and electricity.

Combined boilers for diesel and natural gas are less common than others. This is a rather unusual combination of the most expensive and cheapest fuel. But this model of the combined unit is very technically efficient.

Boilers operating on gas, diesel and solid fuels, last years are gaining more and more popularity. It has become unfashionable to use boilers only on wood, however, boilers with a combination of different types of fuel continue to be produced. In addition, it is not at all necessary to use firewood, they can be replaced peat or wood briquettes, coal or coke.

Gas-fired boilers are no less popular, but these models have the lowest level of control. security and automation, accordingly require more attention and concentration of the owner. In this regard, such boilers have the lowest cost.

Combined gas-solid fuel-electricity boilers. Very common in private and country houses. The only and most important drawback of such boilers is inability to fully heat the entire house. This device can only maintain the optimum temperature level in the system.

A boiler using electricity, gas, diesel and solid fuels is a universal device for heating and water supply residential premises. The use of such boilers minimizes heating costs, and also reduces the risks of operation.

A variation of this model is a combined boiler that runs on electricity and solid fuel (wood).

Combined wood-electricity boiler

The design of this unit is well thought out and practical designed. In order to warm the house in a short time, you can use wood or wood waste. Electric mode operation is switched on only to maintain the optimum level of temperature in the room. This is very convenient, especially at night, when it is almost impossible to constantly monitor the firebox.

Unlike traditional solid fuel boilers, an additional heating element is installed in the heat exchanger tank. In addition, this combi boiler model has a built-in automation system, allowing to change the power and operating modes of the boiler. Also in such models automatic switching between types of fuel is provided, which provides maximum unit safety. It can be concluded that this model of boilers is the most efficient and has a number of advantages over other types of combined boilers.

pros

1. Low cost of the unit;
2. Versatility;
3. Availability;
4. Availability of an automation system;
5. High quality heating.

Principle of operation

This model works almost the same as a conventional solid fuel boiler. Firewood is loaded into the furnace, which is located below, and the heat that is released during the combustion of wood is heated by a heat exchanger with water that enters the heating system. Additional heater maintains the required temperature preventing freezing of the coolant. After burning firewood, it turns on automatically.

What to Look for When Buying an Electric Wood Boiler

A combined boiler that runs on wood and electricity is worth buying, given the main parameters:

• power;
• the presence of a coil for hot water - the second circuit;
• grate material for sifting ash, when using firewood, it is better to give preference cast iron grates, they are the most heat-resistant, ceramic grates are suitable for bulk materials - straw or wood chips;
• unit weight - some models can weigh more than a dozen kilograms, so additional floor reinforcement may be required before installation;
• furnace size;
• valve for silent operation of the boiler;
• heat exchanger material, it can be steel or cast iron the latter are heavier in weight and can crack from temperature extremes, but, unlike steel ones, they will save them from corrosion.

The use of combined heating systems will ensure reliability, high performance and heating efficiency of your home.