Refrigerant charge variation mechanism
AssigneeElectric Power Research Institute, Inc.
InventorWayne P. Reedy
Life of this patent
Estimating the term…
Abstract
A heat pump system capable of heating and cooling an indoor space includes a refrigerant compressor having a discharge side and a suction side interconnected with respective indoor and outdoor heat exchanger coils via a reversing valve, and a condensed refrigerant line interconnecting the indoor and outdoor heat exchangers. Refrigerant charge can be variably added or taken away from the system based on operating conditions using a refrigerant reservoir having a flow regulated first valve connected to the condensed refrigerant line and a similar second valve connected to the suction side. A flow regulated third valve is used to bleed vapor from the reservoir to lower the pressure of refrigerant contained therein relative to the pressure in the liquid line.
Claims5
A heat pump system capable of heating and cooling an indoor space, comprising:
- a refrigerant compressor having a discharge port for discharging compressed refrigerant vapor and a suction port for returning low pressure refrigerant vapor to the compressor;
- indoor and outdoor heat exchangers, each having respective heat exchanging coils having first and second refrigerant ports, and indoor and outdoor expansion devices respectively coupled to said second refrigerant ports;
- a reversing valve having a first port coupled by a pressure line to the discharge port of said compressor, a second port coupled by a suction line to the suction port of said compressor, and third and fourth ports coupled respectively to the first ports of said indoor and outdoor heat exchanger coils;
- said reversing valve having a heating position in which the compressed refrigerant is supplied to the indoor coil and the low pressure vapor is returned from the outdoor coil, and a cooling position in which compressed refrigerant is supplied to the outdoor coil and the low pressure vapor is returned to the indoor coil;
- a condensed refrigerant line interconnecting said indoor and said outdoor heat exchangers for supplying condensed refrigerant from one of said heat exchanger coils to the expansion device of the other heat exchanger;
- and
- refrigerant charge variation means for varying the amount of refrigerant in the system based on operating conditions, including:
- a refrigerant reservoir, having a first branch connected to the condensed refrigerant line and a second branch, separate from said first branch, connected to the suction line, said first and second branches including respective first and second valves and flow restrictor elements connected in series;
- means coupled to the compressor discharge line for detecting the amount of thermal energy of the compressed refrigerant being discharged from said compressor;
- means for actuating said first and second valves based on the thermal energy of the compressed refrigerant in order to transfer refrigerant from the condensed refrigerant line to the reservoir when said thermal energy is below a predetermined level and to transfer refrigerant from said reservoir to said suction line when said thermal energy is above a predetermined level;
- and
- means for lowering the pressure of refrigerant contained in said refrigerant reservoir when the pressure in said reservoir is higher than the pressure of condensed refrigerant in said pressure line.
Dependencies are inferred from the claim text.