二次提升型吸收式变热器热力性能分析

为有效地回收低品位余热 ,该文以水 /溴化锂(H2 O/ L i Br)工质对为例 ,分析了 3种二次提升型吸收式变热器 ,指出其中第一级吸收器和第二级蒸发器相连接的形式(A1- E2型 )是最可取的。并着重分析了 A 1- E2型二次提升型吸收式变热器的热力性能 ,结果表明 ,二次提升型吸收式变热器比单级吸收式变热器有更高的温度提升 ,运行范围扩大 ,但系统性能有所下降。根据对不同工质对的热力分析 ,该文还提出了第一级采用 H2 O/ L i Br,第二级采用三氟乙醇 / N -甲基 - 2 -吡咯烷酮 (TFE/ NMP)为工质对的二次提升型吸收式变热器的设想 ,它既能获得较高的温度提升又有相对较高的性能系数。

Performance analysis of the two stage heat transformer

The efficiency of low grade energy transfor was compared using three kinds of two stage heat transformers. The best two stage heat transformer couples the first stage absorber to the second stage evaporator. And the thermal performance of this system was analyzed in detail. The results show that the two stage heat transformer can reach a higher useful temperature and has a wider working range, but has a lower efficiency than the single stage heat transformer. Based on the analysis of different working fluids, a new two stage heat transformer using H2O/LiBr solution in the first stage and TFE/NMP in the second stage was proposed to obtain a higher temperature lift and better efficiency.