| 摘要 |
1,155,432. Refrigerating. ROBERTSHAW CONTROLS CO. 16 June, 1966 [16 June, 1965], No. 26984/66. Heading F4H. [Also in Division G3] The heating and cooling systems for a building complex are controlled by a known digital computer having a stored programme. Temperatures at selected points of each system, Figs. 1, 2 (not shown), are sensed by thermocouples and compared by the computer with stored predetermined values and the necessary control actions are initiated by digital signals which, through a multiplexer, actuate digital stepping motors positioning the mechanical controls of a system. As shown for a cooling system, Fig. 3, output signals 1P1S from the computer are used to control liquid cooling units 1-3 connected, in series-parallel, to air cooling heat exchangers AHI-AHL which are connected in parallel. The cooling units are identical and unit 1 comprises an evaporator 96 and condenser 100 through which the coolant is circulated by a compressor 98. The condenser is cooled by the water flow through a cooling tower 109 which is circulated by a pump 106. The coolant flow in the evaporator 96 is determined by a vane control 94 positioned, through a pneumatic diaphragm arrangement 88, by a ball-valve 74 positioned by a digital stepping motor 50. The stepping motor 50 is controlled through a transfer network and contacts 42, 46, actuated by alternately energized relay coils 34, 36 responsive to computer output signals 1P1S 3-6. Input signals 1P1S 1-2 control the energization of a motor 98M for the compressor 98, signals 1P1S T1-2 control the tower 109 and 1P1S P1-4 control a motor 106M for pump 106 and a motor 110M for pump 110 in the circulating line to the heat-exchangers AH1-AHL. The monitoring input signals comprise a positional feedback signal 1P1FS from a potentiometer 1PT1 coupled to the stepping motor 50, signals 1KM1-3 from the pump compressors and representing their power consumption; signals 1FM1-3FM1 representative of the flow rate through the cooling units 1-3, signals 1CTS1-3CTS2 representative of the inlet and outlet temperatures of the cooling units, and a signal CRS representative of the common return temperature which are derived to evaluate the temperatures across the cooling units; input signals 1SI-1SL are derived from temperature sensing devices associated with the heat-exchangers AH1-AHL. It is stated that the computer controls the start-up and close-down of a cooling unit and optimizes the operation of the units in dependence on demand. A read-out console is stated to record the efficiencies of the systems. |
