エジェクタを用いた冷媒蒸気再循環による蒸発器の伝熱促進と冷凍サイクルの性能向上

We have proposed new method that re-circulates vapor refrigerant into the evaporator using an ejector to enhance the evaporating heat transfer in the refrigeration cycle. It makes the evaporating heat transfer coefficient higher by increase of the dryness-quality at the inlet of evaporator. We investigated experimentally the coefficient of performance (COP) of the refrigeration cycle and the evaporating heat transfer coefficient with a proposal means, under various evaporating and condensing temperatures and heat loads. As a result, the COP of proposed cycle is 5-13% higher than the conventional cycle with a D.C. inverter compressor by re-circulation of refrigerant. Furthermore, we investigated the dry-out length in the evaporator by authorized empirical equation and evaluated the optimum flow rate of re-circulation.