ENTROPY BALANCE AND PERFORMANCE CHARACTERIZATION OF THE NARROW BASIC PULSE-TUBE REFRIGERATOR

The basic pulse-tube refrigerator is studied using near-isothermal the ory, The theory has been extended to include evaluation not only of th e enthalpy flux, but also of entropy, This allows for dividing the ent halpy flux into heat and work at the extremities of the tube, and as a result, the pulse-tube performance can be determined, Except for a si mple numerical integration, this study proceeds entirely in closed for m, so that an investigation of the complete parameter space can be per formed fairly easily, Since the device is inherently irreversible, the coefficient of performance is limited to values lower than the Carnot limit, and the results show that coefficients of performance up to ab out 50% of the limit are possible, but for relatively small temperatur e differences, outside of the cryogenic range, Still, in the usual arr angement with regenerator, a properly designed basic pulse-tube, with high-pressure amplitude and a suitable ratio between the volume of the tube and the volume of the cooler or reservoir, may conceivably remai n competitive with the orifice-type device, in which, in contrast with the basic pulse-tube, an adiabatic loss at the cold end is unavoidabl e.