膜法半开式吸收式热泵回收烟气余热及水分系统特性分析

燃煤机组锅炉尾部烟气直接排放会造成大量的余热与水分损失。本文基于陶瓷膜管的选择透过性，利用溴化锂溶液的吸湿性，提出一种膜法半开式吸收式热泵系统，其中多通道陶瓷膜管吸收器吸收烟气中余热与水分，高温发生器、回热发生器及气液分离器实现溴化锂溶液的再生。以某330 MW燃煤机组锅炉为例，分析了不同循环工质参数、不同回热蒸汽流量以及吸收器内热交换量变化对膜法半开式吸收式热泵系统的影响。结果表明:溴化锂溶液的流量与溶液出口温度、脱水量呈正相关变化；吸收器内凝结水吸热量增大会提高脱水量，但会降低溶液出口温度；回热蒸汽流量变化会改变系统内各部分热量分布，增大回热蒸汽流量可以减少驱动热源热量，提高系统热回收性能，但存在限值。

Performance analysis on waste heat and moisture recovery from flue gas by membrane semi-open absorption heat pump

The direct discharge of flue gas from the tail of coal-fired utility boilers will cause a lot of waste heat and water loss.Based on the selective permeability of ceramic membrane tubes and the hygroscopicity of lithium bromide solution,a membrane semi-open absorption heat pump system is proposed in this paper,in which multi-channel ceramic membrane tube absorbers absorb waste heat and moisture from flue gas,and high temperature generators,regenerators and gas-liquid separators realize the regeneration of lithium bromide solution.Taking a 330 MW coalfired utility boiler as an example,the effects of circulating fluid parameter,regenerative steam flow and heat exchange amount change inside the absorber on the dewatering performance and heat recovery of membrane semi-open absorption heat pump system are analyzed.The results show that,the flow rate of lithium bromide solution is positively correlated with the outlet temperature and dehydration amount of the solution.The increase of the heat absorbed by condensate water in the absorber increases the dehydration amount,but decreases the outlet temperature of the solution.The change of flow rate of the regenerative steam will change the heat distribution of each part of the system,and the increase of flow rate of the regenerative steam can reduce the heat of driving heat source and improve the heat recovery performance of the system,but with a limit value.