Experimental evaluation of the effect of an internal heat exchanger on a transcritical CO2 ejector system

摘要

This study presents experimental results focused on a performance comparison of a transcritical 2 ejector system%29&ck%5B%5D=abstract&ck%5B%5D=keyword'>CO2 ejector system without an internal heat exchanger (IHX) (EJE-S) to a transcritical 2 ejector system%29&ck%5B%5D=abstract&ck%5B%5D=keyword'>CO2 ejector system with an IHX (EJE-IHX-S). The comparison includes the effects of changes in operating conditions such as cooling water flow rate and inlet temperature. Experiments are conducted to assess the influence of the IHX on the r)%29&ck%5B%5D=abstract&ck%5B%5D=keyword'>heating coefficient of performance (COPr), heating capacity, entrainment ratio, pressure lift, and other parameters. The primary flow rate of the EJE-IHX-S is higher than that of the EJE-S. The pressure lift and actual ejector work recovery are reduced when the IHX is added to the transcritical 2 ejector system%29&ck%5B%5D=abstract&ck%5B%5D=keyword'>CO2 ejector system. Using a more practical performance calculation, the compression ratio in the EJE-S is reduced by 10.0%–12.1%, while that of EJE-IHX-S is reduced only by 5.6%–6.7% compared to that of a conventional transcritical CO2 system. Experimental results are used to validate the findings that the IHX weakens the contribution of the ejector to the system performance.