| 摘要 |
A refrigerant heating and cooling system for a motor vehicle includes an inside coil, an outside coil, expansion valves, a reversing valve, a refrigerant compressor, a chiller and a control device. The compressor, outside coil, an expansion valve and the inside coil define a first circuit for cooling the air within the vehicle. The compressor, inside coil, an expansion valve and the chiller define a second circuit for heating the interior of the vehicle. The chiller is a refrigerant-to-engine coolant heat exchanger. When in the heating mode, the chiller functions as an evaporator, the inside coil functions as a condenser and the engine coolant system is the heat source. The control device varies the flow of the engine coolant through the chiller as a function of the engine coolant temperature in order to maintain a relatively constant set temperature within the vehicle. In the preferred form, the control device is a microprocessor controlled motor driven valve which senses the engine coolant temperature at the inlet to the chiller, a maximum pressure at the compressor discharge or outlet, the vehicle interior temperature, a set or desired temperature and the outside ambient temperature.
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