RU195412U1 - HEAT GENERATOR - Google Patents

Abstract

The utility model relates to heat engineering and is intended for heating air by burning combustible plant waste, which can be used as a coolant or drying agent, used respectively for air heating and ventilation of buildings and structures for various purposes or for supply to drying units. The heat generator contains a fixed on a frame with a lining, a combustion chamber with a grate, divided into combustion chambers and afterburning of volatile substances, a heat exchange unit, a feeder fuel, blower fan, heated air supply fan, flue gas recirculation smoke exhauster. To cool the frame of the combustion chamber and the grate formed by the pipes, a circulation loop of the intermediate heat carrier is used. Cooling occurs due to the transfer of heat in the heater, located on the side of the air inlet to the heat exchange unit. A useful model provides increased performance, reliability and efficiency. The low-temperature two-stage combustion process expands the range of fuels used and reduces the amount of harmful emissions.

Description

The utility model relates to heat engineering and is intended for heating air by burning combustible plant waste, which can be used as a coolant or drying agent, used respectively for air heating and ventilation of buildings and structures for various purposes or feeding into drying units. Mostly, this device is used in agricultural and forestry enterprises using heated air in various dryers by burning their own combustible waste. Thus, the tasks of waste disposal and cost savings in the generation of thermal energy are simultaneously solved.

Known heat-generating installation (RU 2234643 IPC F24H 3/00), containing a combustion chamber with manual maintenance, an ash pan, a chimney, a chimney in the composition of the pipes, supply and exhaust chambers and chimneys, an air duct, a fan and a chimney.

Also known is a heat generator (RU 182 666 IPC F24H 3/00, F24H 3/008) containing a combustion chamber with manual maintenance, a gas rotary box and heat exchange sections. The volume of the combustion chamber is designed for the use of local low-calorie coal.

The disadvantages of the considered heat generators are low reliability, low heat production and inconsistency in the quality of the issued heated agent, the need for manual labor, poor environmental performance.

 The inability to maintain the required thermal power at a constant level and the inconvenience of operation are due to periodic manual loading of fuel into the combustion chamber and the absence of a blower fan.

 The metal walls of the furnace, which are unprotected from the high-temperature effect of the furnace torch, in connection with a possible burnout, limit the applicability of fuels in terms of calorific value and plant power and require air supply to the furnace with a large excess.

 The absence of a blower fan and a stepwise supply of air to the combustion chamber, together with a periodic supply of fuel, leads to increased chemical and mechanical underburning in the flue gases.

 Low reliability due to the possibility of low temperature corrosion, as when cold air is supplied, the temperature of the walls of the pipes of the heat exchange unit can be cooled to a temperature below the temperature of the dew point of the flue gas.

The TPG series solid fuel heat generator with the BOT heat exchanger is known [see on the Internet https://nvt-tehno.com.ua/shop/teplogeneratory-na-sypuchej-organike/]. The heat generator consists of a combustion chamber lined with refractory bricks, an inclined grate composed of cast iron grates, a fuel hopper, a fuel feeder and a blower fan. To prevent overheating, the combustion chamber is surrounded by an air jacket in which the blast air is heated before it is fed under the grate. The heat exchange unit consists of horizontally concentrically arranged afterburners and a rotary chamber, interconnected by channels for the passage of gases. On the outer perimeter of the chambers installed finning. Heated air moves in the annular channels between the chambers.

High material consumption, restrictions on the used fuels, difficulty in maintenance, low reliability, due to the following:

 Refractory brick lining promotes a high-temperature furnace process. In this case, the formation of nitrogen oxides, the processes of slagging of the furnace walls and the introduction of heat-exchange heating surfaces by products of sublimation of ash occur. Regular labor-intensive cleaning of the furnace and heat exchanger is necessary. Thermocyclic stresses cause rapid destruction of the lining and the need for repair.

 Preheating the air supplied under the cast iron grates limits the use of dry high-calorie fuels. Possible rapid burnout of grates and the destruction of the refractory lining of the furnace.

 A longitudinally washing heat exchange unit is characterized by a low heat transfer coefficient, as a result of which its metal consumption and laboriousness of operations for cleaning from ash pollution are increased, while there is a need to cool flue gases with dilution with cold air and use expensive heat-resistant steels.

The objective of the utility model is:

 expansion of the range of used fuels and waste;

 increase in economic and environmental indicators of the heat generator;

 improving the reliability of the heat generator.

The solution to this problem is achieved by the fact that in a heat generator containing a furnace chamber formed by a wiring with a grate, a heat exchanger unit, a fuel feeder, a smoke exhauster and fans for supplying heated air and blast, it is proposed to fix the wiring on a cooled frame, and divide the combustion chamber into honeycomb connected by a connecting flue a combustion chamber with a grate and an afterburner with secondary blast nozzles, moreover, the cooled frame should be included in the coolant circulation circuit with a heater, which is located false before the heated air enters the heat exchange unit.

The technical result provided by the given set of features is, firstly, the expansion of the range of used fuels and wastes, as well as increased efficiency due to the possibility of using instead of purchased fuel various combustible plant wastes - shredded straw, bark and wood wastes, husks. This is achieved by dividing the furnace into two chambers - combustion and afterburning with secondary blast nozzles. In this case, a two-stage low-temperature combustion is organized. The first stage of combustion, including drying, the release of volatile substances and afterburning of coke residue, takes place in the first chamber - the combustion chamber. Air is supplied under the grate in an amount sufficient to burn out the coke residue, but not enough for the combustion of volatile substances. The second stage of combustion takes place in the afterburner, into which air is introduced through the secondary blast nozzles in an amount sufficient for complete combustion. Thus, optimal conditions are created at each stage of the combustion process and the influence of fuel characteristics on the quality and efficiency of combustion is minimized. In addition, efficiency is also enhanced by using recirculation to cool the flue gases before entering the heat exchange unit. Such cooling occurs without an increase in heat loss with flue gases, typical of the case with the use of air.

Secondly, with two-stage low-temperature combustion, environmental characteristics and reliability are increased due to the absence of wall slagging due to high-temperature exposure.

Thirdly, the circulating coolant provides reliable operation of the lining with its simultaneous simplification by fixing it to a cooled frame. A heater located in this circuit before the heated air enters the heat exchanger block provides air heating and, accordingly, protects the heating surfaces of the heat exchanger block from condensation of water vapor and low-temperature corrosion.

To improve reliability and performance, additional technical solutions are applied, paragraphs. 2-9 formulas of a utility model.

According to claim 2, the grate is formed by pipes and is included in the coolant circulation circuit. This increases reliability, as it eliminates burnout of the grate. Reliability is also increased when using antifreeze, p. 3, as it prevents the risk of defrosting the installation in the cold season.

Paragraphs 4 and 6 suggest measures aimed at improving the reliability of the heat exchange unit. To prevent burnout of the metal of the heat exchange unit, the flue gas inlet to the heat exchange unit is connected by a recirculation path to the exhaust gas duct, it has several stages, the first stage being made of heat-resistant steel.

To reduce the temperature and slag during operation on high-calorie fuels, in paragraph 5, it is proposed to connect the recirculation path to the combustion chamber.

To further increase the reliability, economic and environmental indicators, it was proposed in paragraph 7 to install in the furnace chamber a device for layer shaving and ash removal in the form of a screwing bar cooled by the coolant, which ensures a controlled stable furnace process due to its mechanization and automation.

The technical proposals in clauses 8 and 9 increase economic and environmental indicators by improving the quality of the burning out of volatile substances by intensifying their mixing with the oxidizer by a vortex, which is formed in the afterburner due to the tangential introduction of a connecting gas duct into it, as well as by installing secondary blast nozzles in the combustion chamber.

For explanation, the figure shows a schematic diagram of a heat generator.

The heat generator comprises a furnace chamber 2 limited by the wiring 1, with a grate 3, a heat exchange unit 4, a fuel feeder 5, a smoke exhauster 6, a heated air supply fan 7 and a blast supply fan 8. Moreover, the lining 1 is fixed to the frame 9, and the combustion chamber 2 is made as a camera combustion 10 connected through a connecting gas duct 11 to the afterburner 12. Secondary blast nozzles 13 are installed in the afterburner 12, and this design of the combustion chamber 2 creates a separation of the combustion process into two stages and provides a two-stage izkotemperaturnoe, bezshlakovochnoe and environmentally efficient combustion.

The heat generator also includes a coolant circulation circuit 14, which includes a cooled frame 9, an air heater 15, pipes 16 forming a grate 3 and other critical elements requiring cooling, as well as a circulation pump 17. A system with a circulating coolant ensures reliable operation of the lining 1, mounted on the cooled frame 9.

The heat exchange unit 4 has a first stage 18 made of heat-resistant steel, which increases the reliability of the heat generator, and with its input 19 it is connected to a flue gas duct 20, a channel with a smoke exhauster 21 flue gas recirculation.

The combustion chamber 10 is served by a cooled mechanized device 22 for layer shuffling and ash unloading; nozzles 23 are installed in it to supply additional secondary blast.

The proposed heat generator operates as follows. The fuel feeder 5 carries out continuous dosing of fuel from the feed hopper into the combustion chamber 2 limited by the wiring 1. In this case, the fuel is loaded directly into the combustion chamber 10 onto the grate 3 formed by the cooled pipes 16. Under the grate 3 and through the secondary blast nozzles 23, the air blows for the fan 8 combustion in an amount sufficient to maintain a low-temperature regime of gasification and complete burning of the coke-ash residue, but insufficient to completely burn combustible volatile substances from fuels . Then, the flue gases and products of incomplete combustion from the combustion chamber 10 through the connecting duct 11 enter the afterburner 12, and they enter tangentially with the formation of a vortex, therefore they intensively mix, quickly and completely burn in the secondary air stream, which is supplied by the blower fan 8 through nozzles secondary blast 13. After exiting the afterburning chamber 12, the hot products of combustion at the inlet 19 to the heat exchange unit 4 are diluted with an additive of cooled exhaust flue gases, which are fed by a recirculator and 21 of the flue gas duct 20.

At the same time, their temperature decreases to a level 4 safe under conditions of reliable operation of the metal. Flue gases prepared in this way enter the heat exchange unit 4, where they give off heat to the heated air. After passing through the heat exchange unit 4, part of the flue gases is sucked off by a recirculation exhaust fan 21, the rest of the volume of the exhaust fan 6 is discharged into the chimney.

The heat carrier that fills the circulation loop 14 cools the frame 9, the grate pipes 16, the ash flap and ash discharge device 22, and transfers heat to the air heater 15. At the same time, the circulation pump 17 ensures reliable circulation of the heat carrier.

In the heater 15, the coolant transfers heat to the incoming air stream, pumped by the fan 7 for supplying heated air. Such a preliminary heating of the air provides protection of the heating surfaces of the heat exchange unit 4 from condensation of water vapor and from low temperature corrosion. Further, the air is heated in the heat exchange unit 4, and thanks to the first stage 18, made of heat-resistant steel, heating can be carried out to a very high temperature, and sent through the duct for intended use.

The device 22 shuzhivaniya layer and unloading of ash is carried out mechanically, in automatic mode, leveling and mixing of fuel in the layer and the removal of ash from the combustion chamber.

Thus:

 Continuously organized fuel supply and combustion process ensure the stability of the characteristics of the air heated by the heat generator.

 The furnace process, divided into two stages, allows you to burn a wide range of fuels and combustible waste in terms of thermal characteristics without overheating of the lining, intense slagging and sintering of ash, with high environmental performance.

 The lining, mounted on a frame cooled by an intermediate heat carrier, works reliably and has a lightweight design.

 The grate, cooled by the intermediate coolant, eliminates the possibility of burnout grate.

 Dilution of combustion products after the afterburning chamber with chilled flue gases ensures reliable operation of the metal of the heat exchange unit without increasing heat loss with flue gases.

 Preheating the air heated in the heat exchange unit in the air heater prevents the possibility of condensation of water vapor from flue gases on excessively cooled pipes and, accordingly, corrosion and clogging of the heat exchange pipes.

Claims (7)

1. A heat generator comprising a lined combustion chamber with a grate, a heat exchange unit, a fuel feeder, a smoke exhauster and fans for supplying heated air and blast, characterized in that the combustion chamber is divided into a combustion chamber with a grate and an afterburner connected to each other, and combustion chambers and afterburning installed nozzles supply secondary blast. 2. The heat generator according to claim 1, characterized in that the connecting gas duct is introduced tangentially into the afterburner. 3. The heat generator according to claim 1, characterized in that the lining is mounted on a cooled frame, which is included in the circulation of the coolant with a heater located in front of the heated air inlet to the heat exchange unit. 4. The heat generator according to claim 3, characterized in that the grate is formed by pipes and is included in the coolant circuit. 5. The heat generator according to claim 3 or 4, characterized in that the circulation circuit is filled with antifreeze. 6. The heat generator according to claim 1, characterized in that the heat exchange unit contains several stages, and the first stage is made of heat-resistant steel. 7. The heat generator according to claim 1, characterized in that the combustion chamber is equipped with a device for lining the layer and / or unloading the ash.

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