EXPERIMENTAL INVESTIGATIONS ON DEVELOPMENT OF A SINGLE STAGE G-M TYPE PULSE TUBE REFRIGERATOR
A G-M type single stage pulse tube refrigerator has been designed, fabricated and operated with a helium compressor of 1.5 kW. A double-valved double-inlet configuration instead of conventional single-valved one is successfully used in experiments to reduce the DC flow. Operating under double inlet mode, 258 K minimum temperature has been reached at an average pressure of 12 bar and frequency 2 Hz. When operated as orifice type, 260 K is achieved at an average pressure of 9 bar. Minimum temperature at cold end is achieved at optimum opening of double inlet valve at 5 mm and orifice at 3.86 mm as double inlet type. A comparative study of results relating to cool-down, valve optimization and pressure variation, when the system is operated at different configurations is presented here.