ORC直接接触式蒸发器传热性能研究

Study on Heat-transfer Performance of ORC Direct Contact Evaporators

为分析低温余热发电ORC直接接触式蒸发器内分散相在连续相中的传热性能,分别选用新型环保有机工质R245fa和THERMINOL66导热油作为分散相和连续相,进行ORC直接接触式蒸发器传热性能的研究,分析了初始传热温差、工质体积流量和导热油质量流量对ORC直接接触式蒸发器容积传热系数的影响.结果表明:容积传热系数随着传热时间的增加先呈增大趋势,然后逐渐减小并趋于平稳,但大于传热开始阶段的容积传热系数;在工质体积流量和初始传热温差为定值的情况下,为获得较大的容积传热系数,导热油质量流量应控制在较小的范围内.

To analyze the heat-transfer performance of dispersed phase in continuous phase within ORC di- rect contact evaporator for low-temperature waste-heat power generation, the environmental-friendly re- frigerant R245fa and heat-transfer oil THERMINOL-R 66 were respectively taken as the dispersed phase and continuous phase, with which the influence of following factors on the volumetric heat-transfer coefficient of ORC direct contact evaporator was analyzed, such as the initial temperature difference, the refrigerant flow rate and the oil flow rate, etc. Results show that the volumetric heat-transfer coefficient rises first, drops later on, and finally tends to be stable, always being larger than the coefficient at initial period~ for a fixed refrigerant flow rate and initial temperature difference, the flow rate of heat-transfer oil should be controlled within a narrow range so as to obtain higher volumetric heat-transfer coefficient of ORC direct contact evaporators.