| 摘要 |
<p>1,170,507. Refrigerating. N.V. PHILIPS, GLOEILAMPENFABRIEKEN. 28 Feb., 1967 [3 March, 1966], No. 9347/67. Heading F4H. In a refrigeration process gas is passed to and fro in a tube containing material whose entropy charges as a result of variation of an electric or magnetic parameter and which is located between a cooler and a freezer. The entropy of the material and thus its temperature are varied in opposite directions when the direction of gas flow is reversed, and the apparatus is such that gas present at any time at the cooler never reaches the freezer. As illustrated in Fig. 1, a paramagnetic material 6 provided with a solenoid 11 is located between a cooler 9 and a freezer 10, a mass of helium being trapped and moved to and fro by pistons 2 and 3. Masses of porous material 7 and 8 are provided for flow stabilization purposes. When, from the Fig. 1 position gas is moved to the left, the solenoid 11 is energized and the heat generated in the material 6 is carried to the cooler by the portion of helium I-II. When the flow of gas is reversed, the solenoid is de-energized and the cold generated is carried to the freezer by the portion of gas III-IV. The portion of gas II-III acts as a movable regenerator. In a modification, Fig. 3 (not shown), the ends of the duct containing the cooler, material and the freezer are connected to the ends of another duct containing a single piston for displacing the gas. In a further modification, Fig. 5 (not shown), a number of masses of paramagnetic material are located in series between the cooler and freezer and are separated by masses of flow stabilizing material. As illustrated in Fig. 4, the material 36 together will flow smoothing passages 45 are mounted for movement by a rod 47 relative to a coil 41 which is superconducting at the temperature of the freezer 40 and is thermally connected to the freezer. The material is moved into and out of the field of the coil 41 to charge its entropy at appropriate points in the cycle. In another embodiment, Figs. 6 and 7 (not shown), a single piston moves gas through two assemblies of cooler, material and freezer, the cycles for the two assemblies being 180 degrees out of phase and the entropy of the materials being charged by a permanent magnet which is moved to be in magnetic contact with the materials at appropriate points in the cycles. The cooler in the above embodiment may be a heat exchanger supplied with liquefied gas or may be the output heat exchanger of a cold gas refrigerator. It will normally be at a temperature below 30‹ K. The pressure of the helium is maintained above its critical pressure but the operating conditions are such that no phase transition occurs. If temperatures lower than 2À5‹K are to occur the isotope He<SP>3</SP> is used. A liquid may be used instead of a gas in the cycle provided that the operating conditions are such that no phase transition occurs.</p> |
