Development of a 5W at 65 K air-cooled pulse tube cryocooler

LG Electronics (LGE) has developed an air-cooled Pulse Tube Cryocooler (PTC) for HTS applications. The air-cooled PTC provides 5.5 W of cooling at 65 K and 25degreesC ambient with 280 W of input power with a single-acting linear compressor. Its performance is greater than that of an LGE water-cooled PTC of last year, 4.9 W at 65 K and 20degreesC, with 270 W of input power. The air-cooled PTC, compared to the water-cooled one, has a lower-efficiency linear motor, a 3% decrease due to cutting down the cost of the linear motor, and a higher temperature at the surface of the aftercooler, 30degreesC higher than the water-cooled one, Thus, the performance has improved significantly. We have optimized the geometry of the regenerator, the pulse tube, and the inertance tube using both simulation and test; a significant increase of the performance is noted. Also, to maintain the low cost target, we have decreased the cost of the linear motor and used a common heat exchanger for air-cooling.