GB668621A - Improvements in or relating to refrigerating machines operating on the reversed hot-gas engine principle - Google Patents

Abstract

668,621. Refrigerating. NAAMLOOZE VENNOOTSCHAP PHILIPS' GLOEILAMPENFABRIEKEN. April 22, 1947 [JuIy 27, 1944], No. 10743/47. Class 29 In multi-cycle refrigerating machines of the reversed hot-gas engine type, each thermodynamic cycle of the working fluid is performed in more than one cylinder, the operative piston surfaces 191,192 being all arranged in pairs rigidly connected together, one surface 191 of each pair being movable in a heated chamber associated with one cycle while the other surface 192 is movable in a cooled chamber associated with another cycle. Each pair of piston surfaces may comprise the opposite surfaces of the same piston as shown, or two rigidly connected pistons moving in a divided cylinder. The four cylinders 131- 134 each have the top end of one connected to the bottom end of the next by pipes 154-157 leading from the bottom of each cylinder jacket, the pipe 157 from the last cylinder jacket returning to the first cylinder 131. Each cylinder has a heating jacket 135 open to the upper end of the cylinder and heated by the material being refrigerated, a regenerator 136, and a cooling jacket 137 transferring the heat of compression to a water jacket 153 common to the lower ends of the cylinders. The heating jackets 135 have ribs 152 and may project into the space to be cooled. The pistons are reciprocated 90 degrees out of phase by a crankshaft 142 driven by a motor 145. Each cycle of the working gas thus takes place in the space between the top surface 191 of a piston and the bottom surface 192 of the piston in the next cylinder and includes the heating jacket 135, the regenerator 136 and the cooling jacket 137 of the first cylinder. After the piston has reached the top dead centre position as shown in the cylinder 131 expansion occurs in the space 190 and the gas therein cools, absorbing heat from the chamber being refrigerated. The volume of the space 193 beneath the next piston then increases, and the gas passes through the regenerator 136 over cooler 137 to the cooler space 193. Compression then occurs in the space 193 and the gas is returned through the cooler 137, regenerator 136 and heater 135 to the space 190, giving up the heat of compression to the water jacket 153, whereupon the cycle is repeated. The cylinders can be arranged in pairs V-wise, or in a square with the piston driven by a swash plate. In a modification, Fig. 2 (not shown), two cylinders are used, one being divided and having two pistons on one rod, one piston working in each part. The other cylinder is as shown in Fig. 1 and its jacket is connected to the lower part of the divided cylinder so that one of the working spaces is formed between the lower surface of its piston and the upper surface of the piston in the lower part of the divided cylinder.