| 摘要 |
<p>1123310 Valves TEXAS INSTRUMENTS Inc 11 Nov 1966 [3 Jan 1966] 50685/66 Headings G3R R4 R61 and R37D A refrigeration apparatus comprises a compressor 11 driven by an electric motor 12, a condenser 13 and evaporator 15, the flow of refrigerant around the apparatus being controlled by a valve 19. The various signal producing elements include thermistors TH1, TH2 for sensing the temperature of the motor M and the temperature of the cooled space, a sensor HS for sensing the humidity of the space and sensors PS1; PS2 for sensing the pressures in the refrigerating system on either side of the valve 19. Each of the sensors is associated respectively with reference elements R1-R5, the difference signals being combined to produce a signal which, by way of an amplifier A controls the energization of a heating element H1 situated in the valve 19 so as to control the amount of refrigeration. The apparatus is normally controlled by way of signals TH2, HS or TH2 alone if desired, the signals TH1, PS1, PS2 being limiting signals to shut down the system if the motor temperature or the pressures in the refrigerating system become excessive. The valve 19 includes a cylinder 27 in which moves a piston 31 carrying a rod 23 having a conical end co-operating with an orifice 25 so as to meter the flow of refrigerant. Movement of the piston in the cylinder is effected by a spring and a mass of material 35 - such as a silicone rubber - having a temperature coefficient of expansion greater than that of the cylinder 27; expansion of the rubber 35 being caused by the heat generated by the heating element H1.</p> |
