A flue gas waste heat recovery system for a steam injection heat pump cycle

Abstract

The invention discloses a steam jet type heat pump circulating flue gas waste heat recovery system. The steam jet type heat pump circulating flue gas waste heat recovery system comprises a gas-fired boiler, an air preheater and a steam jet type heat pump device, wherein the steam jet type heat pump device comprises an evaporator, a mixing chamber, a diffuser pipe, a condenser and a throttle mechanism, which are sequentially connected to form a loop, as well as a nozzle connected with the mixing chamber; a blow-off pipe is arranged on the evaporator and used for discharging flue gas and condensate water; a boiler low-temperature water supplying channel and a boiler high-temperature water supplying channel are formed in the condenser; the boiler high-temperature water supplying channel is connected to the gas-fired boiler; a high-temperature flue gas channel and a steam branch channel are formed in the gas-fired boiler. Compared with the prior art, the steam jet type heat pump circulating flue gas waste heat recovery system has the advantages that the water supplying temperature can be increased by 5-8 DEG C, and the heat absorption capacity of the supplied water in the boiler is reduced to reduce the fuel gas using amount, so as to achieve the purposes of saving energy and reducing emission.

Description

technical field [0001] The invention relates to a heat recovery device, in particular to a flue gas waste heat recovery system of a steam injection heat pump cycle. Background technique [0002] In order to change the air pollution caused by coal-fired heating in Urumqi in winter, since 2010, Urumqi has launched a "coal-to-gas" project. The implementation of the "coal-to-gas" project has resulted in the blue sky and white clouds in Urumqi. At present, the heating ratio of clean energy in Tianshan District, Shayibake District, High-tech Zone (New District), Shuimogou District, and Midong District in the main urban area of ​​Urumqi has reached 100%, completely realizing natural gas heating, becoming the first in the country A city heated by natural gas. As of the heating period in 2014, a total of more than 700 gas-fired boilers with a hot water capacity of 100,000 to 1 million tons have been installed. These gas-fired boilers absorb the waste heat of the flue gas by install...

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Problems solved by technology

[0004] Disadvantages of the solution to absorb the waste heat of the flue gas by installing the tail flue gas air preheater on the flue of the gas boiler can only use the heat transfer method of temperature difference as the driving force to utilize the waste heat, which makes the utilization rate of low-grade waste heat not high, resulting in The exhaust gas temperature of gas-fired boilers is not low enough, and there is room for further utilization of low-grade waste heat by other technologies

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