Influence of the Main Parameters of the Suction Valve on the Overall Performance of a Small Hermetic Reciprocating Compressor

Abstract

A self actuated valve is commonly used in the intake manifold of small hermetically sealed reciprocating compressors. During the gas exchange process the valve losses influence the overall performance due to the throttling process which increases the pressure drop between the intake port and the gas chamber of such a machine. So there is a rise in the gas exchange work respectively the piston work to get the same discharge pressure. These valve losses influence the COP in two ways. First, in the increase of the consumption of electrical power and second, in the decrease of the mass flow rate. Due to this fact it is important for the designer to understand the dynamic behavior of such a valve. In this paper, numerical and experimental investigations are done to quantify the influence of main parameters of the suction valve on the overall performance of the compressor. The thermodynamic cycle calculation is performed using the AVL BOOST, a CFD software program. The calculation model covers the whole compressor domain between shell inlet and outlet. The dynamic valve displacement is calculated using an equivalent spring-dampermass system. The experiments are effected on a calorimetric test bench.