Assessment of reed valve dynamic behavior in a scroll compressor through visualization

Measurement of reed valve dynamics and movement in compressors is a wellknown technique and can be performed by commercial proximity sensors, strain gauges or in house developed sensors embedded into the valve plate. Although timing and lift information is available through these methods, other modes of fluttering such as torsional movement a more difficult to be obtained. This work tries to address these unknowns by providing real operation information about valve dynamics through high speed imaging and processing of valve lift, valve speed and the presence of torsional movement. A scroll compressor was used and ran in a full system set up, controlling condensing and evaporating temperatures, as well as the speed of the compressor so the results can be used for variable speed systems. It was found that the information obtained from videos fits well with what has been reported in the literature and that the torsional movement was indeed observed and estimated. However, due to low impact velocities, even with torsional movement, valve reliability is not at risk under the conditions in which the visualization was performed.