Design And Research Of Deep Condensation Gas Boiler Based On Absorption Heat Pump

Natural gas belongs to clean primary energy,and its main component is methane（CH₄）,which has high hydrogen content.The content of water vapor in the flue gas after complete combustion is much higher than that of coal and other fossil fuels after complete combustion.The flue gas produced by natural gas combustion contains about 18%volume fraction of water vapor.This part of water vapor reaches its saturated water vapor partial pressure at about 55～60℃,and begins to condense。When condensing to 30℃,the heat released by condensing accounts for 14%of the low calorific value of natural gas,and the heat released by condensing is far greater than the sensible heat of flue gas.The efficiency of gas-fired boiler can be greatly improved by reducing the temperature of flue gas and using the condensation heat of flue gas water vapor.The first type of Li Br absorption heat pump can reduce the temperature of exhaust gas and make use of the condensation heat of flue gas water vapor.The first type of Li Br absorption heat pump is a kind of equipment which uses high-temperature heat source as driving heat source,Li Br solution as absorbent,water as refrigerant,recovers and utilizes the heat energy of low-temperature heat source,makes the required process or heating high-temperature heat medium,and realizes the transfer of heat energy from low temperature to high temperature.Boiler flue gas can be used as a stable low-temperature heat source,boiler combustion has a higher temperature,can be used as a stable driving heat source.Therefore,the boiler itself has the conditions to realize the operation of the first type of Li Br absorption heat pump.In this paper,based on the principle of absorption heat pump,the boiler and absorption heat pump are organically combined to complete the thermal cycle calculation of a absorption heat pump based deep condensation gas boiler with a heating capacity of 800KW and a flue gas temperature of 30℃,and complete the design of its structure and control system.Through the application analysis of the deep condensation boiler,the static recovery period is about 3 years,and the economic benefit is relatively ideal;the deep condensation gas boiler can effectively reduce the water content in the flue gas,the amount of white"smoke"is only 25.6%of the traditional boiler;the total emission of pollutants in the deep condensation gas boiler is reduced by 14.7%;due to the reduction of the flue gas temperature,the chimney suction lift needs to be calculated.Based on the absorption heat pump deep condensation gas boiler,the traditional absorption heat pump and gas boiler are integrated as a whole equipment,which can effectively reduce the unnecessary heat exchange links and auxiliary equipment,reduce the cost of the heat recovery system,and make the technology have a good economy in the small and medium boiler room.