Bi-directional variable subcooler for heat pumps
First Claim
1. In a refrigerant heat pump system selectively operable in a heating or cooling mode, said system including a refrigerant compressor, an indoor heat exchanger, an outdoor heat exchanger, a reversing valve operable to select the heating or the cooling mode by interchanging the operating function of the indoor and the outdoor heat exchangers as an evaporator and a condenser, and first and second expansion/check valve means associated with the indoor and outdoor heat exchangers respectively, and operative to restrict refrigerant flow in one direction while allowing it in another direction,an auxiliary heat exchanger disposed with the outdoor heat exchanger, said auxiliary heat exchanger comprising:
- a first and a second section joined in serial flow arrangement, with one end of the first section being connected in fluid communication with the first expansion/check valve means, and the other end of the first section connected to one end of the second section, the serially joined end of the first and second section and the other end of the second section being connected separately to the second expansion/check valve means,said auxiliary heat exchanger being operative to subcool refrigerant fluid leaving the outdoor heat exchanger during operation of the system in the cooling mode using both the first and second sections, and operative to subcool refrigerant flowing through the second expansion/check valve means and into the outdoor heat exchanger using the first section while storing excess refrigerant in the second section during operation of the system in the heating mode.
10 Assignments
0 Petitions
Accused Products
Abstract
A bi-directional flow auxiliary heat exchanger is disposed in proximity to the outdoor heat exchanger of a heat pump. The auxiliary fin and tube coil is active in both the heating and cooling modes to subcool refrigerant fluid flowing from the condenser. During operation of the heat pump system in the cooling mode, the entire auxiliary coil is used for subcooling; however, a portion of the subcooler is bypassed during heating mode operation to reduce the effective size of the subcooler. The bypassed portion of the auxiliary coil is used for storing excess refrigerant charge. This arrangement provides the system with the optimum amount of subcooling in each mode of operation, and adjusts the refrigerant charge for optimum performance in both the heating and cooling modes.
44 Citations
19 Claims
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1. In a refrigerant heat pump system selectively operable in a heating or cooling mode, said system including a refrigerant compressor, an indoor heat exchanger, an outdoor heat exchanger, a reversing valve operable to select the heating or the cooling mode by interchanging the operating function of the indoor and the outdoor heat exchangers as an evaporator and a condenser, and first and second expansion/check valve means associated with the indoor and outdoor heat exchangers respectively, and operative to restrict refrigerant flow in one direction while allowing it in another direction,
an auxiliary heat exchanger disposed with the outdoor heat exchanger, said auxiliary heat exchanger comprising: -
a first and a second section joined in serial flow arrangement, with one end of the first section being connected in fluid communication with the first expansion/check valve means, and the other end of the first section connected to one end of the second section, the serially joined end of the first and second section and the other end of the second section being connected separately to the second expansion/check valve means, said auxiliary heat exchanger being operative to subcool refrigerant fluid leaving the outdoor heat exchanger during operation of the system in the cooling mode using both the first and second sections, and operative to subcool refrigerant flowing through the second expansion/check valve means and into the outdoor heat exchanger using the first section while storing excess refrigerant in the second section during operation of the system in the heating mode. - View Dependent Claims (2, 3, 4, 5, 6, 7)
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8. In a heat pump system for selectively heating or cooling a space, said system including a refrigerant compressor having a discharge port and a suction port;
- an indoor heat exchanger;
an outdoor heat exchanger;
a reversing valve in fluid communication with both the indoor and outdoor heat exchangers and the suction and discharge ports and operative to selectively connect the discharge port in fluid communication with the indoor heat exchanger and the suction port in fluid communication with the outdoor heat exchanger in a heating mode, and operative to selectively connect the discharge port in fluid communication with the outdoor heat exchanger and the suction port in fluid communication with the indoor heat exchanger in a cooling mode;
first expansion/check valve means for restricting the flow of refrigerant into the indoor heat exchanger in the cooling mode and allowing refrigerant to flow freely out of the indoor heat exchanger in the heating mode;
second expansion/check valve means having a first flow path connected in parallel to a second flow path, for restricting refrigerant fluid flow into the outdoor heat exchanger through the first flow path in the heating mode and for allowing refrigerant fluid to flow freely out of the outdoor heat exchanger through the second flow path in the cooling mode; and
a refrigerant line connecting the first expansion/check valve means in fluid communication with an auxiliary heat exchanger disposed in proximity to the outdoor heat exchanger, said auxiliary heat exchanger comprisinga first section and a second section, one end of the first 25 section connected to the refrigerant line and the other end joined with a "T" connection in series flow relationship to one end of the second section the other end of the second section being connected to the second flow path of the second expansion/check valve means, said "T" connection being connected to the first flow path; whereby in the cooling mode, condensed refrigerant fluid flows from the outdoor heat exchanger through the second flow path and is subcooled as it flows through both sections of the auxiliary heat exchanger; and
whereby in the heating mode, condensed refrigerant fluid flows from the indoor heat exchanger through the refrigerant line and is subcooled as it flows through the first section and into the first flow path, while the second section of the auxiliary heat exchanger is operative to store excess refrigerant charge. - View Dependent Claims (9, 10, 11, 12, 13, 14)
- an indoor heat exchanger;
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15. In a refrigerant heat pump system selectably operable in a heating or a cooling mode, said system including an outdoor heat exchanger, an expansion/check valve means for controlling refrigerant flow into and out of the outdoor heat exchanger, and an auxiliary heat exchanger including a first and a second section disposed in proximity to the outdoor heat exchanger, a method for subcooling refrigerant comprising the steps of:
subcooling the refrigerant leaving the outdoor heat exchanger using both the first and second sections of the auxiliary heat exchanger during operation of the system in the cooling mode; and
subcooling refrigerant flowing through the expansion/check valve means into the outdoor heat exchanger using only the first section while storing excess refrigerant in the section of the auxiliary heat exchanger, during operation of the system in the heating mode.- View Dependent Claims (16, 17, 18, 19)
Specification