Theoretical and experimental investigations on the partial scaling method for the Oxford-type moving-coil linear compressor

•Partial scaling method of Oxford-type moving-coil linear compressor is put forward.•Selected parameters are adjusted to scale compressor with efficiency unchanged.•Input capacity and cooling power increases by 56.3% and 50%, respectively, at 80 K.•A better match between scaled compressor and original cold finger is achieved.•Rationality and feasibility of the method are verified by analyses and experiments.

This paper puts forward the partial scaling method of the Oxford-type moving-coil linear compressor for pulse tube cryocoolers and analyzes the related principles. The systematic experimental investigations are further made to verify the analyses. One of the typical compressors developed in the authors’ laboratory is chosen to be scaled, and then coupled with the original pulse tube cold finger. At the typical operating temperature of 80 K for the pulse tube cold finger, the scaled compressor’s maximum input electric power increases from 236.7 W to 370.0 W, and the cooling power is enhanced from 10.0 W to 15.0 W. The motor efficiency decreases from 78% to 73%, but the average cooling efficiency slightly increases from 11% to 12% of Carnot efficiency due to a better match between scaled compressor and original cold finger. The rationality and feasibility of the partial scaling method have been verified by the theoretical analyses and experimental investigations.