Symbols of thermal circuits in industrial and domestic boiler rooms

Our company positions itself as a manufacturer of innovative compact pellet equipment, designed primarily to work with high-ash fuel. At the same time, the power of heating equipment, boilers is from 25 to 500 kW and pellet burners from 17 to 900 kW, allows talking about the positioning of equipment in the industrial segment. The range includes compact household and industrial boiler houses that implement industrial heating principles for installations with a potential capacity of up to 2.2 MW. From us, industrialists can not only buy a cheap boiler, but also acquire really high-quality industrial-class equipment.

Several reviews can be found on the site like solid fuel boilers FOCUS and pellet burners, as well as complete pellet boiler (boilers) of our brand. Their main feature is their availability in the household or semi-industrial segment. As a result, owners of houses, greenhouses, small farms have the opportunity to install semi-industrial boilers and enjoy the quality of industrial heating.

Boiler equipment FOCUS focused on the use of a fuel pellet as an energy carrier. But the equipment can also be used to burn other problematic fuels, such as coal. Considering that we are talking about industrial heating, in this publication we will consider the main tasks that are solved when deploying industrial boiler houses.

The principle of the passage of combustion products through a plate heat exchanger, which acts as a filter for solid ash particles

a - double-flow through the air with its two-way supply; b - double-flow with one-way air supply; v - multi-threaded through the air; 1 - cold air inlet; 2 - hot air outlet

 

What parameters are taken into account when designing boilers

Improvement of fuel combustion conditions in boiler equipment is directly related to the choice of the energy source and the elemental composition of the fuel. We are talking about the calculated masses, about the methods of efficient combustion of raw materials, taking into account the physicochemical foundations of the combustion of solid organic composition. When you want to buy a boiler inexpensively, you need to understand that some components or units of the boiler units will be missing or partially implemented.

The principle of combustion in the furnace

An important characteristic of combustion is the excess air ratio in the furnace, which also determines the supply of air using a fan and nozzles. Usually, these conditions are taken into account by the so-called layered mechanical furnaces, where air naturally circulates inside the tank and the combustion products are burned. A similar principle is implemented in the FOCUS boiler equipment. It is combined with the design thermal calculation of the flare furnace.

Heat exchanger convection and hydraulic calculation

As has been noted many times, the efficiency of fuel combustion should be comparable to the convective capacity of the heat exchanger. In turn, there is a steam-water mixture in the heat exchange circuit, which moves throughout the available volume according to thermodynamic laws.

To study the conditions for the movement of the steam-water mixture throughout the volume of the heat-exchange and radiator circuit, the method of hydraulic calculation is used. In this case, the movement of the steam-water mass can be realized using natural or forced circulation. Automatically controlled pumps are used in modern heating systems and connection circuits. It is with their help that the elementary functions of climate control are realized when three types of sensors are connected:

• outdoor air temperature sensor;
• room temperature sensor;
• temperature sensor in the circuit.

In practice, only the temperature of the coolant is controlled with the setting of the operating mode using a mechanical or digital controller. If necessary, this can be done automatically by analyzing data from user-defined scenarios and sensors. The overwhelming majority of such systems support control from a mobile device.

Climate control is not a mandatory heating function of the heating system and is available as an option. At the same time, heating engineers must take into account the operating modes of the circulation and ensure the necessary safety, taking into account the cooling conditions of the heat supply circuits.

This concerns, first of all, the transition from iron to polypropylene pipes, the temperature reserve of which does not exceed 90 ° C. In this case, the temperature of the coolant can be much higher. In this case, the introduction of an additional circuit is required, in which the solid fuel boiler will operate. It is usually combined with a thermal buffer, it also performs the functions of hot water supply, that is, at least two-circuit water heating is realized. When connecting collector junctions, one boiler can operate, in addition to hot water supply, to heat the coolant in high-temperature and low-temperature circuits.

 

Connecting a solid fuel boiler FOCUS to a system with a heat buffer with a DHW function

In this case, heating engineers take into account the conditions of steam contamination and the requirements for the coolant. In this regard, the piping of boiler rooms should also include separation devices. The principle of staged evaporation is also taken into account, especially in drum-type boilers. Firewalls imply the calculation of the evaporative capacity of vapor-generating surfaces.

Scale

When calculating and designing a boiler house in the long term, the influence of internal deposits - scale is taken into account. It is also important to make a thermal calculation of different heating surfaces, this is the so-called boiler steel and its analogues.

Structural strength

After carrying out the basic calculations, calculations are carried out to track the strength of the main elements of the boiler. At the same time, it is important to choose the right frame, foundation and structural elements, as well as lining and insulation.

Self-traction and aerodynamic drag

In combination with boiler equipment, when designing a boiler room, control, shut-off, protective and control valves are considered. The composition of industrial boiler houses includes reduction and cooling units, blowing of furnace walls, water cleaning of heating surfaces and other equipment.

In the compact boiler houses FOCUS, despite the deployment of cascade installations with a total capacity of up to 2.2 MW, this can be avoided. In this case, in the boilers themselves, the occurrence of the effect of gravity and aerodynamic resistance of the gas-air duct is taken into account. These conditions are controlled by the built-in microcontroller, which also ensures normal safety mode. You can purchase the equipment as an industrial boiler room of a compact class without sacrificing functionality and heat supply.

Ash collection and ash separation

Boilers FOCUS refer to compact equipment, therefore, some calculations can be neglected and provide the consumer with the opportunity to buy a professional-class boiler at an inexpensive price. At the same time, taking into account the existing problems with the ash content of the fuel pellets, special attention in the design of the FOCUS boiler equipment was paid to ash collection and ash separation. For these purposes directly in pellet burner vibration cleaning is applied.

For the readers, we note that in addition to the used dry inertial ash collection system, wet scrubbers, electrostatic precipitators, pneumatic and hydraulic systems are used in boiler equipment. In the FOCUS boiler equipment, due to the peculiarities of the structural solution, such a rise in the cost of the solution is excessive and not economical.

A plate heat exchanger acts as a mechanical separation device for the boiler. Cleaning is done manually through a convenient door. As an option, you can order a container for ash removal and installation of a pneumatic system. In combination with vibration cleaning of the pellet burner, such an addition will involve a fully automatic ash removal system.

Note that the pellet belongs to environmentally friendly fuel. Boiler equipment FOCUS involves monitoring the maximum permissible emissions and concentrations of harmful substances. First of all, this concerns the afterburning of combustion products and mechanical cleaning of the boiler from ash and slag waste to maintain the calculated efficiency.

Attention was also paid to the protection against corrosion of FOCUS boilers and a stainless steel cladding. The use of carbon steel (due to the lack of special alloys of boiler steel in Ukraine), practically without damage, made it possible to reduce the cost of domestic boiler units, increasing the efficiency of work with any pellet fuel.

Do I need to make a boiler room project or just buy a cheap boiler in a set

Boilers FOCUS, as required, are accompanied by an instruction containing the recommended connection diagrams. It should be noted that, at the request of the customer, the boiler equipment is supplied with complete piping. If you want to buy a boiler inexpensively, choose compact boiler rooms, but check the complete set of the boiler units. Standard equipment will cost an order of magnitude more.

In the case of FOCUS, victalitic shut-off valves (non-welded) are used to deploy boiler rooms. This significantly extends the life of the boiler house in the long term. Despite the fact that the owners of private houses, farms and farms can use the standard harness, it is still recommended to carry out professional design work.

What is a thermal circuit

One of the key design documents in the design of a boiler house is a thermal diagram. It is a graphically drawing diagram of the connection of the main and additional boiler equipment. Elements are united by a pipeline or several of their contours.

In heat power engineering, it is customary to distinguish between several types of thermal schemes:

• principal - includes only basic equipment. For example, boilers, heat exchangers, pumps, deaerators, pipes (without marking fittings and auxiliary elements and secondary pipelines);
• expanded - it includes all equipment and communications with fittings. In large boiler rooms, it is difficult to fully depict all equipment, therefore it is divided into technological processes;
• working (assembly) - this scheme is already performed in orthogonal and axonometric form. Perform with an indication of the location of the equipment, installation conditions and features of the slope. Fittings, dimensions, slopes, fasteners and other important notes are included in the wiring diagram.

The task of the working scheme is to achieve the correct spatial arrangement of the boiler room elements. At the same time, it is important to achieve the smallest number of breaks and intersections of communications when performing installation work.

All of the above schemes are performed in this order and are regulated by the corresponding GOST. The FOCUS instructions show only a schematic diagram of the boiler connection. At the same time, all the secondary and auxiliary elements of the boiler room are indicated.

Conclusion

From what has been described it becomes clear. The FOCUS boiler connection diagram does not replace the design of the connection of heat and power equipment. However, when deploying small boiler houses, the schematic diagram is not done. It is carried out by a specialist with the appropriate qualifications to carry out the work. It is his task to create a real wiring diagram based on a conceptual solution.

The company "FOCUS" offers its services for the design of turnkey boiler houses with a capacity of 25 kW to 2.2 MW. In this case, a cascade principle of connecting low-power equipment is used. In this case, users can set up an autonomous pellet heating system. At the same time, it is possible to achieve a level of comfort that is not inferior to systems with gas heating.

But in this case, the FOCUS pellet boiler room is able to provide at least 50% savings. And this is at a cost per kilowatt of thermal energy when using certified pellets. When using ash pellets, the seasonal economic benefit of switching to pellets will be even greater. So, you need not only to smoke a boiler inexpensively, but it is also important to calculate the operating costs.

Symbols

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