Analysis of a novel combined power and ejector-refrigeration cycle

摘要

A novel combined power and ejector-refrigeration cycle using zeotropic mixture is proposed. In the combined cycle, the turbine exhaust from the organic Rankine cycle entrains the vapor from the ejector-refrigeration cycle. And the zeotropic mixture is divided into the power cycle and the ejector refrigeration cycle through a vapor-liquid separator. And these two flows have different composition. The cycle performance with different fluid composition is evaluated and it is compared with a conventional combined cycle. It is found that the cycle exergy achieves a maximum value of 10.29% with mixture isobutane/pentane (40%/60%), and the thermal efficiency gets a maximum value of 10.77% with mixture isobutane/pentane (70%/30%). The temperature glide in the evaporator achieves a maximum value of 15.09 K with mixture isobutane/pentane (80%/20%). The parametric analysis shows that the cycle performs better in lower condenser temperature. Though the refrigeration cycle achieves lower evaporating temperature in higher generating temperature, the power output is reduced. (C) 2015 Elsevier Ltd. All rights reserved.