September82022

Solid fuel boilers for heating a private house

Autonomous solid fuel boilers for heating a private house work on firewood, coal, coke, peat, pellets, briquettes, pellets, recycle waste from woodworking and agriculture. An eco-friendly heat generator does not depend on centralized gas and electricity supply. Combined models improve the quality of the main or backup source, increase efficiency, and reduce the cost of the heating system.

A solid fuel boiler will provide heating and hot water supply to a private house

Solid fuel boilers for heating a private house: design features

Material for the manufacture of aggregates: cast iron or high-strength boiler steel. The properties of materials have an impact on the service life and thermal inertia of the structure. Steel boilers have a high resistance to deformation under pressure and temperature changes. Cast iron is distinguished by its resistance to corrosion.

Advantages of steel boilers: reasonable price, aesthetic appearance, convenient loading. Advantages of cast iron equipment: unpretentiousness in operation (do not require special preparation of boiler water), durability, the ability to give off heat for a long time.

Pellet boiler burner — cross-sectional view

Cast-iron units are chosen for houses with permanent residence of people. Steel boilers are used for cottages and country houses with periodic residence.

The complete set of heat generators is divided into one- or two-circuit design. One circuit ensures the operation of a solid fuel boiler for heating a private house. Two independent rings allow you to heat the room and supply hot water.

The energy dependence is due to the equipment of the unit with a forced air supply system for gorenje or automated fuel loading.

Types of fuel for the boiler

According to the time of fuel combustion, traditional and pyrolysis heating boilers are distinguished. Gas generators provide long-term decomposition of fuel with the release of heat, which occurs when there is a lack of oxygen. Some models provide for loading solid fuel boilers of long-term gorenje once a week.

Pyrolysis boilers are in demand by consumers due to energy independence, economical fuel consumption, environmental friendliness and high efficiency.

Pyrolysis boiler with automatic fuel supply (pellets)

Rules for the construction of chimneys for solid fuel boilers

Additional requirements for the organization of the chimney are specified by the boiler manufacturer in the technical documentation. Mandatory adherence to the recommendations is necessary to maintain a stable gorenje process, safe and efficient operation of the unit.

Solid-fuel boilers of long-term gorenje with a water circuit for the house. Types, design and principle of operation of solid fuel boilers. Pyrolysis boilers. Boiler selection criteria.

Coal-fired boilers are equipped mainly with ceramic chimneys that can withstand temperatures up to 1200 ℃. The outgoing flue gases do not leave deposits on the smooth ceramic surface. The stable structure of the material is not subject to corrosion, is not afraid of condensation. The elements of the duct, the insulation layer, the expanded clay shell are used for the installation of internal and external sections of the chimney.

Ceramic pipes are a popular material for the arrangement of the chimney of a solid fuel boiler

Metal chimneys are made of corrosion-resistant heat-resistant steel, which withstands a temperature of 800℃. The design of the steel chimney is a sandwich pipe: a layer of thermal insulation is located between the outer and inner metal shell. Steel chimneys are compatible with all types of solid fuel boilers. A mandatory element of a steel chimney is a linear deformation compensator. The node is necessary to preserve the integrity and tightness of the pipe connections through the roof.

Steel chimney construction

Traditional for hearths, fireplaces, heating stoves, refractory bricks for laying out chimneys are currently rarely used. Laying a chimney made of bricks requires skills and experience in the production of furnace work.

Requirements for the device of chimneys of solid fuel boilers:

the section of the chimney must correspond to the size of the boiler pipe for gas removal;
the height, diameter, length of the upper section of the chimney are indicated in the technical documentation of the boiler;
the verticality of the structure is observed regardless of the location of the chimney (the permissible length of the inclined sections does not exceed 1 meter);

Options for the organization of the chimney

double-walled (insulated) chimneys made of metal pipes are used in cold rooms and outdoors (the design prevents cooling of combustion products, reduced thrust and the appearance of condensate);
on the turning sections, hatches are arranged for cleaning the chimney;
observe the fire-fighting distances between the chimney and flammable structures;
the head of the chimney is equipped with a deflector and a spark extinguisher.

Important! A tee installed below the junction of the boiler with the chimney prevents condensate from entering the combustion chamber.

Solid fuel boiler with automatic fuel supply in the heating system of a private house

Wiring diagrams of solid fuel heating boiler

The direct connection of the boiler with the heating circuit is dangerous by the formation of a temperature difference in the heat exchanger. When the “dew point” state is reached, condensate forms inside the furnace space. The aggressive environment promotes the course of oxidative reactions, the formation of deposits and the destruction of the internal surfaces of the generator.

Important! The inertia of the solid fuel combustion process is a feature that must be taken into account when connecting the boiler to the pipe wiring.Gorenje Unbalancing and disruption of circulation can lead to boiling of boiler water and breakdown of the heat generator.

The principle of operation of a solid fuel boiler with a water circuit

Ways to optimize the operation of a solid fuel unit:

tank-heat accumulator between the boiler and the consumer circuit;
hydraulic circuit divider (boiler and secondary);
safety group with adjustable relief valve (near or on the boiler);
expansion tank (open or membrane);
air valves for removing air from the system.

Important! Connection and strapping of the boiler is carried out only with metal pipes. The ideal option is a scheme for strapping a heating boiler according to a project developed by heating specialists.

Solid fuel boiler strapping scheme: 1 — chimney; 2 – overhead thermostat; 3 — solid fuel boiler; 4 — boiler safety group; 5 — electric or gas boiler; 6 — heat accumulator (buffer tank); 7 — three—way valve with electric drive; 8 — air separator; 9 — circulation pump; 10 – three—way mixing valve; 11 — check valve; 12 — overhead sensor; 13 — make—up valve; 14 — dry running protection; 15 — expansion tank; 16 — outdoor temperature sensor; 17 — weather—dependent automation; 18 — room regulator; 19 – heating radiator; 20 – circulation pump; 21 – three-way mixing valve

Brands of Russian-made solid fuel boilers

The analysis of technical characteristics will help to get a general idea of solid fuel boilers of long-term gorenje. Consumer reviews on independent forums give an objective assessment of domestic developments.

Table 1. Solid fuel boilers Zota Mix and Pellet produced by the plant of heating equipment and automation (Krasnoyarsk):

Table 1. Solid fuel boilers Zota Mix and Pellet produced by the plant of heating equipment and automation (Krasnoyarsk)

Dignities:

Efficiency of boilers of the Zota Mix model range — 80%, Pellet — 90%;
combined steel solid fuel boilers Zota Mix work on any type of fuel (liquefied or natural gas, electricity, liquid fuel);
the combustion chamber and the ash box are located inside the water jacket;
an adjustable chimney flap, a mechanical traction regulator and an air intake by an ejector, which is installed in the furnace door, ensure complete combustion of fuel with minimal thrust;
the outer surface of the case is covered with an anticorrosive polymer composition;
a removable door behind the front panel provides access for cleaning the flue;
possibility of repair.

The design of the Zota Mix boiler

Disadvantages:

we need a fuel reserve and a place to store it;
costs of delivery, unloading and storage of firewood, coal, briquettes;
reduced performance of Zota Mix boilers when using low-quality fuel (brown coal by 10-20%, raw firewood by 60-70%);
for Zota Mix — manual fuel loading, ash pan cleaning, furnace walls, flues and flue pipe;
mandatory preparation of boiler water (hardness up to 2 mg-eq/l);
installation in a separate room;
for boilers of the Zota Mix line, it is necessary to install a heat accumulator, a smoke pump, a boiler.

Table 2. Combined solid fuel devices with a water circuit (ACTV). Manufacturer Sibteploenergomash LLC (Novosibirsk):

Table 2. Combined solid fuel devices with a water circuit (ACTV). Manufacturer Sibteploenergomash LLC (Novosibirsk)

Dignities:

budget version of solid fuel boilers with a water circuit for the house (price 11000÷25000 rubles);
compact size;
the water heat exchanger covers the furnace from all sides (except the front);
pull-out ash drawer;
mounting socket for traction control;
the ability to connect to the chimney of any configuration;
the steel heat exchanger allows a simplified connection to the heating harness (without mixing);
the design is adapted to work on gas and electricity.

Karakan boilers from the manufacturer Sibteploenergomash LLC

Disadvantages:

outdated design, primitive automation of poor quality;
the technical characteristics declared by the manufacturer (power, heated area and efficiency) according to consumer reviews do not correspond to the actual indicators.

Table 3. Solid fuel pyrolysis boilers Burzhuy & K from NPO TES LLC (Kostroma):

Table 3. Solid fuel pyrolysis boilers Burzhuy & K from NPO TES LLC (Kostroma)

Dignities:

provides stable gorenje fuel of any grade and degree of humidity;
efficient operation of the boiler with one bookmark for 8 hours;
economical fuel consumption;
generator compatibility with natural or forced circulation systems;
eco-friendly unit, the fuel goes through a complete combustion cycle without generating harmful emissions into the atmosphere;
the design of the furnace provides access to an effective mode of operation in 40 minutes.

Solid fuel pyrolysis boilers “Burzhuy & K”

Disadvantages:

complex installation: the connection must be made by employees of specialized enterprises licensed for this type of activity (otherwise the warranty from the manufacturer does not apply to the unit);
manual fuel laying and cleaning of the combustion chamber;
a lot of weight.

Installation and operation of solid fuel boilers must be carried out in accordance with fire safety regulations

To heat a country cottage, garage or greenhouse, it is possible to manufacture solid fuel boilers for long-term gorenje with their own hands. Videos with materials on this topic can be found on the Internet. But remember that the main condition for using heating equipment is fire safety. And only a certified manufacturer can guarantee the fulfillment of this condition under proper operating and installation conditions of the equipment.

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