エジェクタ冷凍サイクル試験結果のエクセルギーによる性能評価

抄録

There is huge amount of unused heat resources being lower than 373 K not only in industries but also in increasing PV-solar-panels. Utilization of such thermal energy for cooling can greatly reduce the consumption of electricity especially in summer. We focus on the development of an ejector refrigeration-cycle system for enhancing such heat-utilization. We measured the performance of the testing device of an ejector refrigeration cycle. Confirmation of operation-stability of our testing device and exergy evaluation of the performance are reported here. Exergy evaluation is a useful tool for heat-pump systems because thermal energy can be treated as the energy being as the equivalent value of electricity. The ideal exergy-efficiency is always 100 %, which differs from COP being greater than unity. It is important that COP doesn’t show the ideal value. Calculations of the exergy assuming constant-temperature heat-sources just as treating of Carnot cycle in Thermodynamics from the principle, and the other considering the temperature change as used in heat-transfer processes for rational heat-exchanger designing are also reported here. As a result, both exergy efficiencies are still very low, which suggests us more improvements to be possible and to be required for the next stage of the development.