Calculation Method and Analysis on Thermal Compressor Ejection Characteristics

Abstract

Thermal compressor, a similar device like steam driven jet pump, is usually used to keep the vacuum level of condensers in nuclear power plant. Meanwhile, the utilization of thermal compressor is an effective way to recover the heat of exhausted steam from turbines, improving the energy efficiency of secondary circuit in nuclear power plants. The extreme entrainment ration of thermal compressor is a significant parameter to describe its working performance. The present research conducts the theoretical derivation of the related physical process inside the thermal compressor and builds a theoretical model calculating the maximum entrainment ration. The results show that the present model can predict the ejection ability of the thermal compressor with satisfactory accuracy and application scope. The average relative deviation between calculated and experimental result is 9.7% and the maximum deviation does not exceed 23%. Moreover, the results of the model calculation indicate that the ejection ability is enhanced with the increase of primary and suction steam pressure, but weakened by the increase of compressed steam pressure. The entrainment ration increases with the superheat degree of primary steam because of the increasing critical velocity while the superheat degree of suction steam makes no obvious influence.