The influence of efficiency of the cooling system on the thermodynamic parameters and performance of a two - stage VC 20.96 reciprocating compressor designed to serve as a marine engine starter

The paper presents results of the research related to the analysis of the thermodynamic and flow processes occurring in a prototype VC 20.96 two-stage liquid-cooled reciprocating compressor. The compressor has been developed and manufactured by H. Cegielski Poznan metal works in collaboration with the Poznan University of Technology. The research related to the VC compressor was realized within the KBN 3127/C.T07-6/2002 project titled “Development of design of type-series of reciprocating compressors and their implementation in production”. The basic task of the project was to develop two type-series of liquid- and air- cooled reciprocating compressors of the V- and W- arrangement, designed to serve as marine engine starters. The result of the design work was the manufacturing of two compressors: the VC 20.96 liquid-cooled compressor and the WP 18.80 air-cooled one. The main aim of the research described in this paper was to evaluate the efficiency of the cooling system which uses inter-coolers integrated with the compressing stages and the cooperation of the compressing stages in terms of pressure ratio distribution. Owing to the cooling method, the applied design assumptions enabled to develop a compact compressor fulfilling the assumed operating parameters.