摘要 |
The present invention relates to a defrost arrangement for refrigeration systems and in the preferred embodiment to reverse cycle, heat pump refrigeration systems. A secondary defrost circuit is provided including valves which permit refrigerant flow to by-pass the compressor and the expansion device only when compressor operation terminates and the system pressure differential is equalized. The refrigerant flow in the secondary circuits allows refrigerant to flow between the upper portions and lower portions of the indoor and outdoor heat exchangers. This free non-restrictive flow of refrigerant causes the relatively warm refrigerant in gaseous phase when present in the condenser to displace the relatively cold refrigerant in liquid phase when present in the evaporator, with the flow continuing until the system equalizes.
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