用于烟气全热回收的全开式吸收式热泵

Full-open absorption heat pump for total heat recovery of flue gas

提出一种新型全开式吸收式热泵技术用于烟气余热回收,利用燃烧器产生的高温烟气在发生器中驱动稀溶液再生,降温、加湿后的烟气经冷凝器被冷却水冷却到饱和状态,再与待回收的目标烟气混合进入吸收器,被浓溶液吸收.其中,冷凝和吸收过程放出的热量可用于供热.系统的3个主要部件均为喷淋塔结构,节省了传热管材,有效降低初投资;同时,这种全开式常压结构对强度要求不高,可进一步降低制造和维护成本.该技术在热网回水温度较高时仍能有效回收烟气余热,而且烟气最终被处理到过热状态,避免了排出过程中结露腐蚀的问题.采用欧拉-拉格朗日方法建立了细致的液滴动力学和耦合传热传质模型,根据该模型理论计算,设计并搭建了实验样机,结果表明,系统COP最高达到1. 621,排烟露点最低达到36. 2℃,相对湿度为62. 4%.仿真与实验结果吻合较好,理论模型得到了验证.

A novel full-open absorption heat pump(FOAHP)for the waste heat recovery of the flue gas was proposed.The high-temperature flue gas produced by the burner drived the regeneration of the weak solution in the generator.Having been cooled and humidified in the generator,the driving flue gas entered the condenser and was cooled to the saturation state by the cooling water.The residual driving flue gas was mixed with the objective flue gas and was recovered by the strong solution in the absorber altogether.The condensation heat and the absorption heat were used for district heating.The three main components,including generator,condenser and absorber were all spray tower structured,saving considerable heat transfer materials and therefore cutting the initial investment much.Besides,all the spray towers were operated under atmospheric pressure,without requirement for high mechanic strength,so the fabrication and maintenance cost can be further reduced.The system could efficiently recover waste heat even if the return temperature of the district heating network was relatively high.Moreover,the objective flue gas was processed to the superheat state,in avoidance of the condensing corrosion in the discharging process.A detailed model for the liquid particle dynamics and the conjugate heat and mass transfer by Eulerian-Lagrangian formulation was established.On the basis of the simulation results,a prototype system was developed and experimented.Experimental results show that the system can achieve the COP of 1.621,the exit dew point of 36.2℃and 62.4%RH Simulation results are well in agreement with the experimental ones.