Hermetic Compressor, Suction Valve, Fluid Structure Interaction, Reed Valve
Hermetic reciprocating compressors are widely used in small and medium size vapor compression refrigeration systems. 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 study of these processes in the compressor itself is very complex, mainly because the small size of the compressor. Thus, experimental analysis in laboratory valve models can be useful for improving the understanding of the flow characteristics. This work consists in an experimental investigation of the fluid-structure interaction problem in a model of reed suction valve with diameter ratio equal to 1.3. The fluid-structure interaction problem was studied by measuring the instantaneous position of the reed by using a very accurate optical sensor. Results for Reynolds number based in the orifice inlet parameters varying from 2,000 and 20,000 were obtained. Due to hydrodynamic instabilities of the flow, the reed does not reach an equilibrium position, even for the constant mass flow rates prescribed for the flow. The results show that there is a well defined frequency for the reed movement for a given Reynolds number, which reduces slightly for increasing Reynolds numbers. Besides helping to improve the understanding of the flow characteristics in reed type valves, these results can also be used for validating computational codes used for the solution of general fluid-structure interaction problems, and specifically for reed type valves.