A comprehensive investigation of non-condensable gas and condenser temperature effects on power plant ejector performance by considering condensation flow regime

Abstract

Considering that the cycle of the steam power plant (Rankin) works with steam and water as working fluid in a closed cycle, the condenser will be one of the most important parts of this cycle, which has the task of changing the phase (condensation) of the turbine output steam and making it possible to transfer it to the beginning of the cycle. In addition to the working conditions of the cycle, such as the temperature and pressure of the turbine end, the performance of the condenser depends on the environmental conditions, such as the ambient temperature and the absence of non-condensable gases. In this paper, the effects of the condenser temperature and mass fraction (MF) of the air inside the condenser are investigated on the performance of the ejector (POE). It is shown that the effect of the condenser temperature on the POE is much higher than the effect of the air MF. With the increase of the condenser temperature and the air MF, the flow rate of the suction flow improves, and the entrainment ratio (ER) rises. With the temperature increment from 320 K to 340 K (without air in the condenser), ejector efficiency reduced by 61.16%, and exergy destruction enlarged by 12.13%. By incrementing the air MF from 0 to 0.35 at the temperature of 340 K, ejector efficiency, exergy destruction, and ER improve by 2.84%, 6.29%, and 3.88%, respectively.