Heating of premises with wood and electricity boilers. 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 support mode. The fuel in the furnace runs out - the boiler stops working, respectively, the coolant starts to cool down. This problem is well known to private sector residents and owners. country houses.

It is not always possible to constantly throw up coal or wood when filling the firebox, and stopping the boiler in winter is fraught with a sharp decline temperatures in all living quarters.

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

Layout of solid fuel and electric boilers when used together in a heating system

The operation of solid fuel boilers requires periodic monitoring by a person - all models of such units need to be loaded with fuel.

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

The main task for the owner of the house when the heating is 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. Consider in detail the connection of a solid fuel boiler with a heating device powered by electricity.

The working one looks like this: a solid fuel unit with a capacity of 50 kW should be combined with an electric boiler with a capacity of 28 kW. The operation of the electric heating device is periodic. The unit must be on the catch - be ready to turn on immediately after stopping the main equipment. The electric boiler starts up when the fuel in the solid fuel boiler runs out, and the temperature of the coolant in the system drops to 50 0 C. At the same time, there must be a water tank in the circuit for the hot water supply system, which in this case plays the role of a heat accumulator.

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

• heating radiators - require 30 kW;
• underfloor heating system - up to 15 kW;
• storage tank for the DHW system - an average of 300 liters.

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

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

A 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 the critical level, the electric boiler, equipped with heating elements, is included in the work, taking on the task of heating the house. A thermostat and a three-way valve control the temperature of the hot water tank. When the temperature of the water in the DHW system circuit drops, the heat carrier is fed into the coil for heating hot water. A correctly connected electric boiler, competent piping with a solid fuel boiler, will make your system fully controlled.

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

Combined heating boilers

Another, less costly 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. The idea to combine electrical device with a solid fuel unit is not new, but it became possible to organize the production of appropriate heating equipment only after the advent of combined automation devices and materials of a new generation.

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

In practice, it looks like this: the fuel fill has already completely burned out, so the boiler has gone out. The boiler water starts to lose its temperature accordingly. Solid fuel is being replaced by electric heating. Now the heating mechanism works like a conventional electric boiler until the firebox is filled with another batch of wood or coal.

After the main unit reaches the optimal operating mode, the control unit turns off the electric heating elements, the heating works again 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;
• no condensation, since the first heating of the device is carried out in both modes - main and auxiliary;
• the entire heating complex is constantly in working order, which is important in the long absence of the owners of the house.

However, this technique also has disadvantages.

A significant disadvantage for combined heating devices is volatility. In the absence of mains voltage, the system loses its efficiency and versatility.

Important! When installing the equipment, it is necessary to take into account the potential of the household wiring, which may not be rated for the capacity of the equipment being installed. The presence of circuit breakers for small amperage will lead to constant power outages in the house. Before installation, make sure that your allotted power consumption limit is able to satisfy the operation of the heating equipment.

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

How to achieve joint operation of electrical and solid fuel units

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

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

What you need to pay attention to during installation:

• both devices must have a reasonable power ratio, a coal-fired or wood-fired heater is the main source of heat, so its power must be twice the power of the electric boiler;
• both units are connected in parallel, which gives the independence of the operation of one from the other;
• a solid fuel unit is the main one and is connected to a large circuit, while an 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 heating device is set to a certain heating temperature - for solid fuel equipment, the operating temperature should be 60-70 0 С, while on the electric unit the temperature value is set at 40-50 0 С, 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 decides himself how to organize the autonomous heating system. The proposed technical solutions will allow not only to eliminate the unpleasant consequences of the decay of the main heater during a fierce winter, but will also give some energy savings.

The efficiency of operation of solid fuel units and electric boilers in steam 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 combined heating boilers, universal for a private house, operating simultaneously on two types of fuel. Combining firewood and electricity together is a rather clever solution; such a boiler is quite reliable, compact and practical. And in the event of a power outage or 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 in one fell swoop:

1. For heating, two alternative energy sources are used at once relative to natural gas.
2. The issue of cooling the premises is being resolved 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 you 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-fired heating boilers of the latest generation with a large firebox are made so that switching to electric heating occurs automatically when the water temperature in the boiler falls below a certain level. Naturally, the reverse transition to solid fuel combustion occurs with the help of external actions.

Electric wood boiler design

Externally, a combined TT boiler, firewood, electricity is in no way different from a conventional solid fuel unit. In fact, this is the same wood-burning heating boiler, its only difference is that it has a heating element 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 jacket and there is a special contact hole to which the wiring contacts are connected.

The device of this type of heater 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 heat exchanger of a water-tube or fire-tube type, where the combustion products transfer most of the heat to the water before being released into the chimney;
• at the bottom of the firebox there is a grate, and under it is an ash chamber;
• firebox and ash pan equipped with doors in front;
• to adjust the intensity of combustion, there is a mechanical draft regulator or an air blower (if there is no manual control of the air damper).

Domestic 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 are connected to the control panel using an electric cable, and the heating part is immersed in the coolant.

How does a combination boiler work?

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

1. The boiler is fired up and heated up as usual. When solid fuel is burning, 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 have burned out, the temperature of the coolant in the system gradually drops to a certain value, after reaching which the heating element (one or more) is switched on by the signal from the temperature sensor. At this moment, the boiler starts working on electricity.
3. After the next portion of firewood or coal is loaded, the water in the system begins to warm up from the side of the combustion chamber, electrical part automatically turns off until the moment when 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 ensures comfortable conditions in a private house.

The advantages of universal boilers

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

1. Versatility. You will have a 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 been burned out in the loading chamber. This will maintain a comfortable temperature inside the room, and in the event of your long absence, it will prevent pipes and radiators from freezing.
3. Comfort. Maintaining the temperature with electricity is of great service in helping to get rid of the problem of night trips to reload the fuel into the combustion chamber.
4. If electricity metering is done according to a multi-tariff scheme, then in addition to convenience, you can also save on the night work of heating elements.
5. Thoughtful device. The heat is distributed in such a way that the loss of heat energy is close to a minimum, which makes the boilers quite efficient.
6. Long period of operation. If properly operated, such a boiler can serve you 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 mode of operation with the help of the heating element is limited by the uninterrupted supply of electricity.
8. You can find models with pre-built pipes in order to be able to connect a "warm floor" system.

Combined heating boilers, which operate on both wood and electricity, cope with their task even with low-power mode.

Disadvantages of combined units

Electric heaters of a universal boiler are only supposed to maintain the temperature of the water in the system, full replacement they will not be able to burn solid fuel. The reason for this is the low power of the heating element unit, which are mounted by manufacturers on solid fuel boilers. This feature, unfortunately, is one of the serious disadvantages of combined boilers for heating a private house with wood.

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

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

Do not forget one more important detail. As with the classic solid fuel boiler, the wood-fired electric combi boiler must be connected to hot water heating via a three-way valve, as shown in the diagram below. A small circulation loop is necessary to protect the furnace from the negative effects of condensate during firing up.

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

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

How to choose a firewood electricity boiler?

Manufacturers offer combined heating boilers that run on both wood and electricity, which differ in performance, power and configuration. 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. Combustion chamber dimensions - its volume will show how often it will be necessary to load fuel.
3. Quiet - installation of a special valve will ensure quiet operation of the unit.
4. Number of circuits - some models carry out water heating 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 can be made of 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. Grizzlies. The material of manufacture can be very different. It can be either cast iron or ceramics. Cast iron has a higher heat resistance and is suitable for the combustion of any solid fuel. Ceramic-coated cast iron honeycomb grates are suitable for bulk materials that consume more oxygen during combustion.
8. Unit weight and dimensions. Due to the large dimensions, it may be necessary to strengthen 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 is required. If the area of \u200b\u200bthe 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 \u200b\u200b400 m2. This may entail budget overruns both for the purchase of the unit and for its subsequent operation.

A combined wood-fired and electricity boiler is perhaps one of the most successful solutions for heating a summer cottage or a small private house. In the cottage, which has 2-3 floors, heating elements will only save the system from freezing. Combined boilers will help out if there is no way to use a constant and reliable source of energy. In addition, these boilers will save money quite seriously if you use more expensive fuel as a backup option.

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 established based on the requirements of safety rules and technology requirements.

Our units run on solid fuel and are designed for wood heating of summer cottages and private country houses of low storey. The area of \u200b\u200brooms heated with wood is from 80 to 320 square meters.

The design of the wood-burning appliance makes it possible to additionally use the electric heating of the coolant. For 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 to avoid temperature fluctuations in the heating system between furnaces. When using water as a heat carrier, electric heating will protect the system from freezing in case of prolonged downtime during the cold season.

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

Installation of heating elements

The heating element is not included in the sale of the wood-burning boiler, but is an option that must be purchased separately. For combined wood-fired boilers of low power up to 18 kW, a tubular electric heater of 1-3 kW is suitable, for 18-32 kW devices, 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 on / off the electric heater. The unit is equipped with boiling protection and a light signal.

Heating elements with a power of 1 to 3 kW are single-phase and are powered from 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 from a network with a voltage of 220/380 V. When installing the unit, connect the ground.

Until 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 is natural gas. However, the time has come non-standard solutions, since energy resources are constantly becoming more expensive, and which one will be profitable for use tomorrow is unknown. That is why there has been a massive interest in heating installations such as an electric wood-fired boiler.

Why are combined units so good?

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;
• to play it safe for the future, having in reserve 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.

It is also important to organize heating with electric wood-burning boilers in new buildings, for the same reasons. At the same time, it is possible to recall the old-fashioned methods and install a gravity heating system in order to maximize independence from external influences. Although a convection system is not the best solution in terms of efficiency, it is an affordable 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 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 the contacts for connecting electrical wires... In fact, the combi plant has a combustion chamber for loading solid fuels, an ash chamber with a damper through which combustion air passes, and a grate.

Household combined boilers for wood and electricity can be equipped with both a water-tube heat exchanger and smoke tubes. Some models are supplied and hobslocated at the top of the combustion chamber. That is, these are full-fledged solid fuel plants with an efficiency of 75-85%. But they have one design feature: one of the walls of the furnace, 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 shirt. it special case the scheme by which electric-wood heating boilers are made, heating elements can be built into the boiler tank in other ways.

When, for any 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.

Boiler operation description

The heating elements are controlled by the electric unit, and the intensity of solid fuel combustion is regulated by the air supply thermostat, opening the ash chamber flap with a chain at a certain angle. That is, the control functions of the electric and solid fuel parts of the heater are separate. If air is supplied to the furnace by a forced fan, then both parts are controlled by the automatics for the wood boiler. In the first case, the algorithm is as follows:

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

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

Having reached the water temperature set on the control panel, the heating elements are turned off and the coolant is heated with wood until the operating temperature. The intensity of combustion is controlled by a chain-driven thermostat, and as soon as the water reaches the operating temperature, it shuts off the air supply.

When the combi boiler burns its main fuel and there is no new load, the coolant will start to cool down and at a certain moment the sensor of the electric unit will work and it will turn on the heaters that will maintain the water temperature until the next firewood is loaded.

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 non-volatility 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 unusual for conventional solid fuel units:

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

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

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

Conclusion

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

Large-scale construction of suburban real estate led to the rapid development of the heating systems market. The owners of private and country houses are increasingly preferring modern systems autonomous heating, refusing gas water heaters... This is often due to the high cost of a natural resource or the inability to connect gas to the house. Universal combined boilers are gradually replacing gas units.

Combined boilers are designs that are capable of operating on different types fuel. Versatility These units also lies 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 drops in electricity. If problems arise, you can easily switch to another fuel source. The combined equipment can operate on diesel and solid fuels, gas and electricity.

Combined boiler device

Types of combined boilers

Depending on the combination of fuels, they emit different 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.

Gas, diesel and solid fuel boilers, last years are gaining more and more popularity. It has become out of fashion 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.

Firewood gas boilers are no less popular, however, 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 an optimal temperature level in the system.

A boiler using electricity, gas, diesel and solid fuel is a versatile device for heating and water supply living quarters. The use of such boilers minimizes heating costs and also reduces the risks of operation.

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

Combined wood-electricity boiler

The design of this unit is well thought out and practical. 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 optimal temperature level 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 fuels is provided, which provides maximum safety of the unit. 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 unit cost;
2. Versatility;
3. Availability;
4. Availability of an automation system;
5. High quality heating.

Principle of operation

This model works in almost the same way as a conventional solid fuel boiler. Firewood is loaded into the firebox, which is located below, and the heat that is released during the combustion of wood is heated by a heat exchanger with water, which enters the heating system. Additional heating element maintains the required temperature, preventing the coolant from freezing. After the firewood burns out, 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, taking into account the basic parameters:

• power;
• the presence of a coil for hot water - the second circuit;
• grate material for screening 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 may weigh more than a dozen kilograms, so additional floor reinforcement may be required before installation;
• the size of the firebox;
• valve for silent boiler operation;
• 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 from corrosion.

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