Determination of the effective force and flow areas in an actual valve model used in refrigeration compressors

• Grant number: 14/24121-4
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: January 01, 2015
• End date: December 31, 2015
• Field of knowledge: Engineering - Mechanical Engineering - Thermal Engineering
• Principal Investigator: José Luiz Gasche
• Grantee: Eduardo Postingel Falcetti
• Host Institution: Faculdade de Engenharia (FEIS). Universidade Estadual Paulista (UNESP). Campus de Ilha Solteira. Ilha Solteira , SP, Brazil

Abstract

Hermetic reciprocating compressors are widely used in small and medium-sized refrigeration systems based in the vapor compressor cycle. One of the main parts of this type of compressor is the automatic valve system used to control the suction and discharge processes. The experimental or numerical/analytic study of these processes is very complex, mainly because the presence of fluid structure interaction during the operation of the valves as well as due to the geometric complexity of the valve design. For that reason, simplified models as radial diffusers have been used to represent the valve systems. Two very important parameters used to represent the behavior of the valve systems for the design and simulation purposes of the whole compressor are the effective force and flow areas. These parameters can be obtained by using experimental or numerical methodologies. The majority of the data available in the literature has been obtained by using the radial diffuser as a model to represent the valve system. In this project, a real geometry usually used in suction valves will be used as a model in order to numerically simulate the flow to determine those parameters. Simulation for Reynolds numbers based in the orifice diameter ranging from 3,000 to 20,000 will be performed considering actual valve aperture observed in small and medium-sized compressor. The simulations will be performed using an open and free computational code named Open FOAM, which is a continuously updated tool largely used for investigating a wide category of engineering problems.