“…The proportion of exergy loss in compressor and rotary valve is similar to that in GM PTC [ 18 ]. In Stirling cryocooler, the efficiency of linear compressor is up to 80%∼90%, which is much higher than that of the compressor used in GM cryocooler [ 30 ]. As the cooling temperature decreases, the regenerator loss gradually increases in proportion to the loss of the whole cryocooler.…”