On the Modification of Suction Valve's Aperture of a Reciprocating Compressor

摘要

The pulsation of the refrigerant fluid inside the suction chamber is one of the most important sources of noise and vibration in eciprocating compressors. The pulsation inside suction chamber is directly related to the aperture of the suction valve. Usually reciprocating compressors used in domestic refrigeration appliances use reed valves with a passive aperture, i.e., opened solely by the pressure difference across them. In this work the modification of the suction valve's aperture is evaluated via a numerical analysis. The aim of this study is reduce the sound pressure level inside the suction chamber without compromising the compressor's thermodynamic efficiency. In a first moment, different apertures were imposed on the suction valve with intuit to evaluate their influence on the sound pressure level inside the suction chamber and on the total compressor noise. An optimization analysis is also performed pursuing to obtain an aperture on the suction valve that minimizes the pressure inside suction chamber and maximizes the thermodynamic efficiency. Furthermore, in order to generate the external force on the valve a control system with an electromechanical actuator and a linear quadratic regulator was used. This control system was implemented inside the compressor numerical methodology and its operation was simulated. After the simulations it was seen that the control system was able to produce a desired aperture on suction valve. In addition some apertures showed lower sound pressure levels inside the suction chamber without a significant reduction of the compressor efficiency. Although the electromechanical actuator was able to produce the external force necessary to modify the aperture of the valve, the energy to accomplish this task was relevant when compared to the energy of whole system.