ORC系统蒸发器夹点温差的数值分析和实验研究  

Numerical Analysis and Experimental Investigation of the Evaporator PPTD in ORC System

作　　者：马新灵[1] 王聪[1] 石文琪 孟祥睿[1] 张景迪 邱宇恒 潘佳浩 MA Xinling;WANG Cong;SHI Wenqi;MENG Xiangrui;ZHANG Jingdi;QIU Yuheng;PAN Jiahao(School of Mechanical and Power Engineering,Zhengzhou University,Zhengzhou 450001,China)

机构地区：[1]郑州大学机械与动力工程学院,河南郑州450001

出　　处：《郑州大学学报（工学版）》2023年第1期65-69,82,共6页Journal of Zhengzhou University（Engineering Science）

基　　金：河南省科技攻关计划项目(162102310504);河南省高等学校重点科研项目(19A480005)。

摘　　要：有机朗肯循环(ORC)是一种高效回收余热的可靠手段。考虑蒸发器的换热面积和系统的热力性能,自定义了性能评价指标F(·),在热源温度为105~165℃、蒸发器夹点温差为3~30℃时,分别从工质流量和蒸发温度的角度,模拟分析了夹点温差对系统性能的影响。结果表明:系统的净输出功和热效率均随夹点温差的降低而增加,且分别在热源温度为165℃、夹点温差为3℃时达到最大值53.53 kW和12.21%;一定工质流量下,热源温度为165℃时,F(·)的值最小,此时最优夹点温差为15℃;一定蒸发温度下,F(·)的值随夹点温差的增大一直减小。在自主搭建的小型ORC低温余热发电试验平台上,分别研究了不同的热源流量、冷却水流量和工质流量下,蒸发器夹点温差对ORC系统性能的影响。结果发现:当热源流量为4 m^(3)/h,系统在较低的蒸发器夹点温差下有更好的表现,此时存在使系统性能最佳的工质流量和冷却水流量,分别为700 kg/h和3 m^(3)/h。Organic Rankine Cycle(ORC),a reliable way in recovering waste heat efficiently was examined in this study.Firstly,considering the heat exchange area of the evaporator and the thermodynamic performance of the sys-tem,the performance evaluation index F(·)was defined.When the heat source temperature was 105-165℃and the evaporator pinch point temperature difference(PPTD)was 3-30℃,the influence of the evaporator PPTD on the system performance was simulated and analyzed from the aspects of working fluid flow rate and evaporation tem-perature,respectively.The results showed that the net output work and thermal efficiency of the system increased with the decrease of PPTD,and respectively reached the maximum value of 53.53 kW and 12.21%when the heat source temperature was 165℃and the PPTD was 3℃.At a certain working fluid flow rate and the heat source temperature was 165℃,the F(·)was the minimum,where the optimal PPTD was 15℃.At a certain evaporation temperature,the F(·)decreased with the increase of PPTD.Then,on the self-built small-scale ORC low-temper-ature waste heat power generation test platform,the influence of the evaporator PPTD on the performance of ORC system at different heat source flow rate,cooling water flow rate and working fluid flow rate was studied.It is found that when the heat source flow rate was 4 m^(3)/h,the system performed better with a lower PPTD,meanwhile the working fluid flow rate of 700 kg/h and cooling water flow rate of 3 m^(3)/h made the system performance the best.

关 键 词：蒸发器夹点温差 实验研究 热力学性能 有机朗肯循环 

分 类 号：TK115[动力工程及工程热物理—热能工程]