The effect of driving voltage waveforms on the efficiency of linear compressor

Abstract

Linear compressors, known for their oil-free operation and elimination of crank mechanism, have found extensive applications in cryocoolers and domestic refrigeration. The efficiency improvement of linear compressor is crucial for refrigerators and cryocoolers, particularly in space application. This paper experimentally studies the impact of driving voltage waveforms on the efficiency of linear compressors, employing four different waveforms for comprehensive analysis: sine wave without crest, sine wave without trough, sine wave, and sine wave without both crest and trough. By fixing compressor stroke and piston offset, the results show that the sine wave without a crest and sine wave without a trough outperform the sine wave and sine wave without both crest and trough in terms of mass flow rate and adiabatic efficiency. The sine wave without a trough demonstrates an 8% enhancement in adiabatic efficiency compared to the standard sine wave. This superior performance is attributed to the reduction in body pressure variation because of faster arrival at datum position, causing lower gas leakage across the radial clearance gap.