CAJ | 학술논문

针对100℃以下流体的余热回收,建立了采用低沸点工质的双循环螺杆膨胀机余热回收系统优化模型,根据工质在蒸发器出口的热力状态不同,对不同膨胀过程求解,并分析了影响系统性能的主要因素.结果表明:对于工质蒸发温度的选择,当可以忽略蒸发侧泵耗时,宜采用以机组效率最大为目标进行优化设计,当必须考虑蒸发侧泵耗时,宜采用以系统效率最大为目标进行优化设计;对于螺杆膨胀机膨胀比的选择,当余热温度<100℃时,工质R245fa的最佳膨胀比为4,丁烷的最佳膨胀比为3,当余热温度>100℃时,最佳膨胀比的值增大;对于循环工质的选择,应考虑单位质量做功能力强、蒸发压力低和最佳膨胀比小的有机物等.
침대100℃이하류체적여열회수,건립료채용저비점공질적쌍순배라간팽창궤여열회수계통우화모형,근거공질재증발기출구적열력상태불동,대불동팽창과정구해,병분석료영향계통성능적주요인소.결과표명:대우공질증발온도적선택,당가이홀략증발측빙모시,의채용이궤조효솔최대위목표진행우화설계,당필수고필증발측빙모시,의채용이계통효솔최대위목표진행우화설계;대우라간팽창궤팽창비적선택,당여열온도<100℃시,공질R245fa적최가팽창비위4,정완적최가팽창비위3,당여열온도>100℃시,최가팽창비적치증대;대우순배공질적선택,응고필단위질량주공능력강、증발압력저화최가팽창비소적유궤물등.
An optimizing model of dual-cycle low-temperature waste heat recovery system using screw expander was proposed in this paper. In this analysis, the working fluids were below boiling temperature, and the heat resource was waste thermal fluid below 100 ℃. According to the thermal states of working fluids at the evaporator outlet, the factors affecting the system performance were analyzed through calculations in different expanding processes. The results show that as for the option of evaporate temperature, when power consumption of the pump at evaporator section can be neglected, the optimal design aims at the maximum of expander efficiency; when the power consumption can not be neglected, the optimal design aims at the maximum of the system efficiency; as for the option of expansion ratio, when waste heat source temperature is below 100 ℃, the optimal expansion ratio of the working fluid R245fa is 4, that of the working fluid butane is 3; when waste heat source temperature is above 100 ℃, the optimal expansion ratio increases: as for the option of working fluid, some organic matter with low evaporating pressure and low optimal expansion ratio while with strong working capability per unit mass needs to be considered to adopt. The conclusions provide references for the further engineering applications.