Prevention of flooded starts in heat pumps
AssigneeCarrier Corporation
InventorsAlexander Lifson, Michael Taras
Life of this patent
Estimating the term…
Abstract
A heat pump is provided with a method and control for eliminating flooded starts. In particular, the heat pump at start-up is operated for a short period of time in the opposite mode to that in which it had been operated before the previous shutdown. In this way, the compressor ingestion of liquid refrigerant is limited or completely eliminated. After a short period of time, the heat pump is moved back to the intended mode of operation. Additional features can be added to the control scheme to limit this type of operation at start-up only to certain ambient conditions or only to a prolonged period between shutdown and start-up.
Claims20
A heat pump comprising:
- a compressor, said compressor delivering refrigerant to a discharge line, and receiving refrigerant from a suction line, said discharge line and said suction line communicating with a reversing valve, said reversing valve being movable between a heating position and a cooling position, said reversing valve directing refrigerant between an indoor heat exchanger and an outdoor heat exchanger in opposite flow directions in said heating position and in said cooling position, and a control for said reversing valve, said control being programmed to move said reversing valve to the opposite position relative to an intended position at start-up for a period of time then move said reversing valve to said intended position.
A method of operating a heat pump comprising the steps of:
- (1) operating said heat pump in one of a cooling and heating mode;
- (2) shutting down said heat pump;
- (3) starting said heat pump back up to run in said one of said cooling and heating modes, by initially moving said heat pump to operate in the other of said cooling and heating modes;
- and
- (4) switching said heat pump to said one of said cooling and heating modes after running in said other of said cooling and heating states for a period of time.
Dependencies are inferred from the claim text.