RU2347147C2 - Method of flue gas purification and heat utilisation and device for its implementation - Google Patents

Abstract

FIELD: heating, burning.

SUBSTANCE: invention relates to heating engineering and can be used to purify gases of heat power plants, heating installations, industrial boiler houses and to utilise heat of these gases. An exhaust gas flue of a boiler furnace is equipped with an open-end metal casing of a low-temperature heater connected through a cyclone and filter purification system, a catalyst for carbon monoxide removal and through large-diameter heating manifold pipes with suction tubes of air inlet filters of internal combustion engine which provide for the necessary pressure difference and draught in the flue. The large-diameter pipes are laid in the heated ground under greenhouses and are selectively heat insulated leaving an air pocket over the pipes which is protected by perforated covers and closing hatches for dust removal. The low-temperature heater is connected to the high-temperature heater through the main closed pipe loop and to the manifold pipes for heating greenhouse rooms through an additional closed loop parallel to the main one, the high-temperature heater is made as a water jacket of a cooling system of an internal combustion engine. The flue gases are finally purified from harmful chemical compounds in combustion chambers of internal combustion engines by thermal incineration.

EFFECT: complete flue gas purification, increasing efficiency of heating installations due to the utilisation of flue gas heat.

2 cl, 1 dwg

Description

The invention relates to heat engineering and can be used for cleaning gases of thermal power plants, heating plants, industrial boilers and heat recovery from these gases.

There is a method of heat recovery of exhaust process gases, including the supply of dusty exhaust gases to cyclone dust separators, sludge filtration, the supply of purified gases to a heat exchanger with coolant layers, stepwise heat exchange with cooling of purified gases with a liquid coolant flow, the use of a heated stream for technological purposes [1].

The known method does not allow to utilize the heat of polluted gases of chimneys of significant cross-section, discharging a large gas stream, since already at the first stage of heat transfer foam-bubble layers of the coolant will not cope with the passage of this gas stream due to the inability to maintain the pressure drop (draft) between chimney and boiler furnace.

Closest to the technological essence of the proposed is a method of utilization and purification of flue gases, including intensive ejection (suction) of flue gases and the creation of rarefaction in the chimney while maintaining a pressure differential between the chimney and the boiler furnace, purification of the flue gases in the pipe with a sprayed liquid in the form of dispersed small droplets, heat transfer between flue gases and a liquid coolant of a low-temperature heater, supply of a heated liquid coolant and its cooling in a high eraturnom preheater, wherein the liquid coolant is cooled and fed through a conduit to a low temperature heater and further for technological purposes to repeat the work cycle [2].

The disadvantage of this method is the need for a chimney, emissions of even purified flue gases from which pollutes the surrounding atmosphere.

The known method of utilizing flue gas heat does not allow the use of heat of highly heated flue gases at the inlet to the pipe, this heat is lost as the flue gases pass through the vertical exhaust pipe and is only partially used by the low-temperature heater, so the efficiency of the use of flue gas heat remains low.

A chimney device [3] is known, comprising a gas outlet trunk with a metal finned multi-sectional heat exchanger and an unloading window located inside it, characterized in that the heat exchanger is made sectional in the form of interconnected external and internal collectors, while the heat exchanger is connected to a turbine rotating an electric generator.

A disadvantage of the known device is the need for a vertical pipe trunk for the emission of flue gases with pollution of the surrounding atmosphere.

The closest in technical essence to the proposed is a device [2] for heat recovery and flue gas cleaning, comprising a housing with inlet and outlet ducts, a ventilation system, a low-temperature water heater for technological purposes, a high-temperature heater with nozzles for supplying and discharging a liquid coolant, a cleaning system water and flue gases from particulate matter.

The known device operates in the presence of a vertical chimney barrel, through which the flue gas after incomplete cleaning enters the surrounding atmosphere, polluting it. The use of flue gas heat occurs partially in the upper part of the device case after its partial cooling, and not at the inlet of the supply gas duct.

The technological result of the proposed method for heat recovery and flue gas cleaning, including intensive flue gas suction by creating a vacuum in the chimney while maintaining the flue gas draft pressure from the exhaust gas duct of the boiler furnace, dust separation and sludge filtration, heat exchange between flue gases and a heat transfer fluid of a low-temperature heater, the supply of liquid coolant and its cooling in a high-temperature heater, from which the heated coolant liquid through the pipe the wire is fed to a low-temperature heater to repeat the operation cycle, the use of heated liquid coolant for technological purposes is achieved by maintaining the flue gas draft by means of a high-temperature heater by the suction pipes of the air intakes of internal combustion engines, the total volume of air intake of which is equal to or greater than the flow rate of flue gases from a unit of time supply duct, for technological purposes, heat of liquid heat carriers obtained from low temperature is used a flue gas heater immediately at the outlet of the supply gas duct and from a water jacket for cooling internal combustion engines, as well as heat from collector pipes of larger diameter laid in a heated medium and connecting the supply gas duct with the intake of the internal combustion engine through a cyclone and filter cleaning system for flue gases , and heat from the manifold pipeline of the liquid cooling system of internal combustion engines forming a low-temperature hearth with the pipeline revatelya parallel main closed loop, the final purification of flue gases from the harmful chemical compounds produced in combustion chambers of internal combustion engines by their thermal calcination.

The technical result of the proposed device for heat recovery and flue gas cleaning, comprising a housing with inlet and outlet ducts, a ventilation system and cyclone and filter flue gas purification from solid particles, a low-temperature water heater for technological purposes, connected by a closed circuit pipe to a high-temperature heater with nozzles for supplying and discharging liquid coolant, is achieved by the fact that the low-temperature heater is mounted on a metal casing the flue gas duct, the high-temperature heater is made in the form of a water jacket for the cooling system of the internal combustion engine, which is connected to the collector pipe for heating the technological premises via an additional parallel main closed circuit, the body of the flue gas duct through the cyclone and filter flue gas purification system and the carbon monoxide catalyst is connected through the heating manifold large diameter pipes with suction nozzles for engine air intakes of combustion, the larger diameter tube selectively insulated and provided with hatches purification.

The drawing shows the proposed device for heat recovery and flue gas cleaning.

The proposed method of heat recovery and flue gas cleaning is implemented by a device (drawing), which contains a housing 1 with a fan 2 in the inlet duct 3 and a metal case 4 in the outlet duct 5, made in one piece with a low-temperature water heater 6 for technological purposes, connected in a closed loop pipeline 7 with pipes 8 and 9 of the inlet and outlet of the heat transfer fluid from the high-temperature heater 10, made in the form of a water jacket cooling system of the internal combustion engine 11, and akzhe for additional parallel to the main closed circuit - a collector pipe 12 Heating technology space 13, such as residential houses, greenhouses or factory floor. At the same time, the body 4 of the exhaust gas duct 5 through a system of cyclones 14 and filters 15 for cleaning flue gases from solid particles and a carbon monoxide catalyst 16 is connected to the intake pipes 18 of the filters 19 of the air intakes of internal combustion engines through heating manifolds 17 of large diameter. At the same time, collector pipes 17 of large diameter are laid in a heated medium, for example, in the soil 20 of greenhouses 13, are selectively insulated with a heat insulator 21 (fiberglass, etc.) from an unheated medium, and their uninsulated sections are made with an air cavity 22 closed by perforated covers 23, and the length of the pipe 17 of larger diameter are equipped with technological hatches (not shown) for their periodic additional cleaning.

A device for heat recovery and flue gas cleaning (drawing) by the proposed method works as follows.

The vertical trunk of the chimney duct is destroyed and a metal housing 4 of the low-temperature water heater 6 of the proposed device is installed on the exhaust duct 5. By a fan 2 from the boiler furnace body 1, flue gases from the inlet gas duct 3 are driven into the exhaust gas duct 5 and through a low-temperature heater 6 into a cyclone and filtration cleaning system. The heat of the flue gases (t≈145-160 ° C) is given through the metal casing of the low-temperature heater 6 for heating water for technological purposes (space heating, etc.). The flue gases coming from the housing 4 of the low-temperature heater 6 to the cyclones 14 are cleaned of solid particles and then passed through filters 15 for final cleaning of fine dust into the carbon monoxide catalyst 16. The purified flue gas after the catalyst 16 is sent to the collector pipes 17 of a larger diameter (d≈1.0 ÷ 1.5 m), laid in the soil at a depth (≈0.5 m) under the greenhouses 13. The heat of the flue gases from the pipes 17 through the air cavity 22 and perforated covers 23 of the casing of the thermal insulator 21 heats the soil 20 of the greenhouses. Flue gases with harmful chemical compounds are then sucked out from the collector pipes 17 of larger diameter through the nozzles 18 of the filters 19 by the air intakes of the internal combustion engines 11 into the combustion chambers, where they are finally neutralized after high-temperature calcination and emitted into the atmosphere. In this case, the total volume of flue gases absorbed by the air intakes per unit time should be equal to or greater than the flow rate of flue gases from the exhaust duct 5 to create a pressure difference between them and the required draft, which is regulated by the number of internal combustion engines 11 used. The heat of internal combustion engines 11 is accumulated in a water jacket 10 and cooled by a liquid heat carrier of a high-temperature heater and enters from a pipe 9 into a closed circuit of a pipeline 7 for technological needs and through an additional parallel closed circuit to a collector pipe 12 for heating greenhouse premises. The cooled liquid coolant flows back through the supply pipe 8 to the cooling water jacket 10 of the internal combustion engine 11. Internal combustion engines 11 are equipped with electric energy generators 24 for lighting technological rooms and domestic needs. Larger diameter pipes 17 are periodically cleaned of dust through special built-in hatches (not shown).

The proposed method and device for heat recovery and flue gas cleaning will completely eliminate existing chimneys and the harmful effects of flue gases on the environment. Practical research indicates the complete neutralization of harmful chemical compounds in flue gases after their calcination in the combustion chambers of internal combustion engines. The method of heat extraction from flue gases immediately at the outlet of the exhaust gas duct and from internal combustion engines for technological needs significantly increases the efficiency of heating boilers. There is a great commercial interest of large industrial enterprises in the use of the proposed inventions.

Information sources

1. USSR copyright certificate No. 1314220, class. F27D 17/00, 1985 (analogous to the method).

2. USSR author's certificate No. 1728593, cl. F23J 15/00, 1990 (prototype of the method and device).

3. USSR author's certificate No. 773391, cl. F23J 11/00, 1979 (similar in design).

Claims (2)

1. A method of heat recovery and flue gas cleaning, including intensive flue gas suction by creating a vacuum in the chimney while maintaining the flue gas draft pressure from the exhaust gas duct of the boiler furnace, dust separation and sludge filtration, heat exchange between flue gases and a liquid coolant of a low-temperature heater, supply of liquid heat carrier and its cooling in a high-temperature heater, in which the liquid is cooled and fed through a pipeline to a low-temperature heater for repetition cycle of operation, the use of a heated liquid coolant for technological purposes, characterized in that the flue gas draft pressure is maintained by a high-temperature heater with suction nozzles of the filters of the air intakes of internal combustion engines, the total volume of air intake of which per unit time is equal to or greater than the flow rate of the exit of flue gases from the exhaust gas duct of the furnace the boiler, for technological purposes, use heat from liquid coolants obtained by a low-temperature heater m from the flue gases at the outlet of the exhaust gas duct of the boiler furnace and from the water jacket for cooling the internal combustion engine, as well as heat from the collector pipes of larger diameter laid in the heated medium and connecting the supply duct with the air intakes of internal combustion engines through the cyclone and filtration flue gas cleaning system , and heat from the manifold pipe of the liquid cooling system of internal combustion engines, forming with the pipeline of the low-temperature heater paral closed to the main circuit, and the final cleaning of flue gases from harmful chemical compounds is carried out in the combustion chambers of internal combustion engines by calcining them. 2. Device for heat recovery and flue gas cleaning, comprising a housing with inlet and outlet ducts, ventilation systems and cyclone and filter cleaning of flue gases from solid particles, a low-temperature water heater for technological purposes, connected by a closed loop pipeline to a high-temperature heater with supply pipes and removal of liquid coolant, characterized in that the low-temperature heater is mounted on a metal casing of the exhaust gas duct, high-temperature The first heater is made in the form of a water jacket for the cooling system of an internal combustion engine, which is connected to the collector pipe for heating technological rooms via an additional parallel main closed circuit, the exhaust duct body through a cyclone and filter flue gas purification system, and the carbon monoxide catalyst is connected through larger diameter heating manifold pipes with intake pipes of the intakes of internal combustion engines, with larger pipes meter selectively insulated and provided with hatches purification.