Abstract: A vapor compression system (20; 120; 220; 320) has: first (22A; 122A; 222A) and second (22B; 122B; 222B) compressors; first (40) and second (46) heat exchangers; and one or more expansion devices (52; 52A, 52B). Means (32A, 32B; 32A, 32B, 126A, 126B; 32A, 32B, 232A, 232B) are provided for switching the system between operation in first and second modes using the respective first and second compressors. In the first mode: the first compressor compresses refrigerant; the compressed refrigerant is cooled in the first heat exchanger; the cooled refrigerant is expanded in at least one of the one or more expansion devices; and the expanded refrigerant absorbs heat in the second heat exchanger. In the second mode: the second compressor compresses refrigerant; the compressed refrigerant is cooled in the second heat exchanger; the cooled refrigerant is expanded in at least one of the one or more expansion devices; and the expanded refrigerant absorbs heat in the first heat exchanger.

Abstract: A method for operating a heat pump (20; 300) includes operating in a cooling mode wherein heat is absorbed by refrigerant in the indoor heat exchanger (26) and rejected by refrigerant in the outdoor heat exchanger (24). The heat pump switches to operation in a heating mode wherein heat is rejected by refrigerant in the indoor heat exchanger, heat is absorbed by refrigerant in the outdoor heat exchanger, and there is an ejector (60) motive flow and ejector secondary flow. In the heating mode a refrigerant pressure (PH) or temperature (TL) is measured and, responsive to the measured refrigerant pressure or temperature, at least one of a fan speed is changed and a needle (132) of the ejector is actuated.

Abstract: A method for operating a heat pump (20; 300) includes operating in a cooling mode wherein heat is absorbed by refrigerant in the indoor heat exchanger (26) and rejected by refrigerant in the outdoor heat exchanger (24). The heat pump switches to operation in a heating mode wherein heat is rejected by refrigerant in the indoor heat exchanger, heat is absorbed by refrigerant in the outdoor heat exchanger, and there is an ejector (60) motive flow and ejector secondary flow. In the heating mode a refrigerant pressure (PH) or temperature (TL) is measured and, responsive to the measured refrigerant pressure or temperature, at least one of a fan speed is changed and a needle (132) of the ejector is actuated.

Abstract: Systems and methods for defrost control in a heat pump are disclosed. In some embodiments, a system comprises at least one processor; and memory storing instructions executable by the at least one processor, the instructions when executed cause the system to: determine a heat load forecast; determine a frost growth forecast based on the determined heat load forecast; determine one or more control parameters of the heat pump based on the determined frost growth forecast.

Abstract: A refrigeration system is provided and includes a common suction line, a common discharge line, first and second high-side compressors disposed in parallel to receive low-pressure refrigerant from the common suction line and to direct high-pressure refrigerant to the common discharge line, a first pipe connected to the first and second high-side compressors at vertical heights at which an oil supply is required to remain higher and a second pipe connected to the first and second high-side compressors at vertical heights sufficient to maintain gas pressure balance between the first and second high-side compressors.

Abstract: A system has: a compressor having a suction port and a discharge port; an ejector having a motive flow inlet, a suction flow inlet, and an outlet; a separator having an inlet, a vapor outlet, and a liquid outlet; a first heat exchanger; an expansion device; and a second heat exchanger. Conduits and valves are positioned to provide alternative operation in: a cooling mode and a heating mode. In the cooling mode, a needle of the ejector is closed. In the heating mode refrigerant passes sequentially from a first section of the second heat exchanger to a second section. In the cooling mode refrigerant passes in parallel through the first section and the second section.

Abstract: A system (20; 300) has: a compressor (22) having a suction port (40) and a discharge port (42); an ejector (32) having a motive flow inlet (50), a suction flow inlet (52), and an outlet (54); a separator (34) having an inlet (72), a vapor outlet (74), and a liquid outlet (76); a first heat exchanger (24); an expansion device (28); and a second heat exchanger (26; 302). Conduits and valves are positioned to provide alternative operation in: a cooling mode; a first heating mode; and a second heating mode. In the cooling mode and second heating mode, a needle (60) of the ejector is closed.

Abstract: A method for operating a heat pump (20; 300) includes operating in a cooling mode wherein heat is absorbed by refrigerant in the indoor heat exchanger (26) and rejected by refrigerant in the outdoor heat exchanger (24). The heat pump switches to operation in a heating mode wherein heat is rejected by refrigerant in the indoor heat exchanger, heat is absorbed by refrigerant in the outdoor heat exchanger, and there is an ejector (60) motive flow and ejector secondary flow. In the heating mode a refrigerant pressure (PH) or temperature (TL) is measured and, responsive to the measured refrigerant pressure or temperature, at least one of a fan speed is changed and a needle (132) of the ejector is actuated.

Abstract: A HVAC system includes a compressor having a low pressure input and a high pressure output. The compressor is driven by a motor having a liquid coolant flowpath configured to cool and lubricate the motor. The motor has a coolant input and a coolant output. An evaporator is in communication with the compressor, and includes a coolant input and a coolant output. A condenser is in fluid communication with the evaporator and the compressor. A first coolant flowpath, includes a coolant drive system connecting the output of the condenser to a valve switching device. A second coolant flowpath connects the output of the condenser to the input of the evaporator and to a second input of the valve switching device. A third coolant flowpath connects the valve switching device to the inputs of the motor. A fourth coolant flowpath connects outputs of the motor to the input of the evaporator.

Abstract: A vapor compression system (20; 120; 220; 320) has: first (22A; 122A; 222A) and second (22B; 122B; 222B) compressors; first (40) and second (46) heat exchangers; and one or more expansion devices (52; 52A, 52B). Means (32A, 32B; 32A, 32B, 126A, 126B; 32A, 32B, 232A, 232B) are provided for switching the system between operation in first and second modes using the respective first and second compressors. In the first mode: the first compressor compresses refrigerant; the compressed refrigerant is cooled in the first heat exchanger; the cooled refrigerant is expanded in at least one of the one or more expansion devices; and the expanded refrigerant absorbs heat in the second heat exchanger. In the second mode: the second compressor compresses refrigerant; the compressed refrigerant is cooled in the second heat exchanger; the cooled refrigerant is expanded in at least one of the one or more expansion devices; and the expanded refrigerant absorbs heat in the first heat exchanger.

Abstract: A system (20; 300) comprises: a compressor (22) having a suction port (40) and a discharge port (42); an ejector (32) having a motive flow inlet (50), a suction flow inlet (52), and an outlet (54); a separator (34) having an inlet (72), a vapor outlet (74), and a liquid outlet (76); a first heat exchanger (24); an expansion device (28); and a second heat exchanger (26; 302). Conduits and valves are positioned to provide alternative operation in: a cooling mode; a first heating mode; and a second heating mode. In the cooling mode and second heating mode, a needle (60) of the ejector is closed.

Abstract: A system (20; 300) comprises: a compressor (22) having a suction port (40) and a discharge port (42); an ejector (32) having a motive flow inlet (50), a suction flow inlet (52), and an outlet (54); a separator (34) having an inlet (72), a vapor outlet (74), and a liquid outlet (76); a first heat exchanger (24); an expansion device (28); and a second heat exchanger (26; 302). Conduits and valves are positioned to provide alternative operation in: a cooling mode; a first heating mode; and a second heating mode. In the cooling mode and second heating mode, a needle (60) of the ejector is closed.

Abstract: A system (20; 300; 500) comprises: a compressor (22) having a suction port (40) and a discharge port (42); an ejector (32) having a motive flow inlet (50), a suction flow inlet (52), and an outlet (54); a separator (34) having an inlet (72), a vapor outlet (74), and a liquid outlet (76); a first heat exchanger (24); at least one expansion device (28, 30; 520); a second heat exchanger (26); and a plurality of conduits and a plurality of valves (100, 120, 130, 140, 144, 148, 150; 100, 140, 144, 148, 150, 320, 340; 100, 120, 530). The conduits and valves are positioned to provide alternative operation in: a cooling mode; a first heating mode wherein the ejector has a motive flow and a suction flow and where utilizing a first expansion device (30; 520) of the at least one expansion device; and a second heating mode utilizing the first expansion device and wherein the ejector has a suction flow and essentially no motive flow.

Abstract: A heat pump system includes a refrigerant circuit, at least one variable speed compressor operating with a maximum pressure ratio of at least 5.0 and a variable speed range of at least three times (3×), a heat absorption heat exchanger, a heat rejection heat exchanger, an ejector disposed on the refrigerant circuit upstream of the compressor to extend a pressure ratio range and a volumetric flow range of the compressor in the cold climates, a separator disposed downstream of the ejector and upstream of the heat absorption heat exchanger, and at least one variable speed fan configured to move air through the heat rejection heat exchanger to provide a predefined an air discharge temperature greater than 90° F. A two-phase refrigerant is provided to an inlet of the heat absorption heat exchanger with a quality of less than or equal to 0.05.

Abstract: A system (20; 300) comprises: a compressor (22) having a suction port (40) and a discharge port (42); an ejector (32) having a motive flow inlet (50), a suction flow inlet (52), and an outlet (54); a separator (34) having an inlet (72), a vapor outlet (74), and a liquid outlet (76); a first heat exchanger (24); an expansion device (28); and a second heat exchanger (26; 302). Conduits and valves are positioned to provide alternative operation in: a cooling mode; a first heating mode; and a second heating mode. In the cooling mode and second heating mode, a needle (60) of the ejector is closed.

Abstract: A cooling system includes a main closed-loop refrigerant circuit having a compressor and a condenser. The cooling system also includes a subcooler closed-loop refrigerant circuit having a compressor and a condenser. A portion of the condenser of the subcooler circuit is in parallel with the condenser of the main circuit with respect to air flow. A single exhaust fan can be in fluid communication with both the condenser of the main circuit and the condenser of the subcooler circuit.

Abstract: A system (10) includes a fluid with components that evaporate at different temperatures, a condenser (12) with an inlet (22) and an outlet (24), a pump (14) with an outlet (28) and with an inlet (26) connected to the outlet (24) of the condenser (12), and an evaporator (16). The evaporator (16) includes an inlet (30) connected to the outlet (28) of the pump (14), an outlet (31), evaporating tubes (38), pool boiling tubes (42), and a fluid distribution system (33) for spraying the fluid over the evaporating tubes (38). The system (10) further includes a turbine (18) with an inlet (44) connected to the outlet (31) of the evaporator (16), an outlet (48) connected to the inlet (22) of the condenser (12), and a drive shaft (46). A generator (20) is connected to the drive shaft (46) of the turbine (18).

Abstract: A cooling system includes a main closed-loop refrigerant circuit having a compressor and a condenser. The cooling system also includes a subcooler closed-loop refrigerant circuit having a compressor and a condenser. A portion of the condenser of the subcooler circuit is in parallel with the condenser of the main circuit with respect to air flow. A single exhaust fan can be in fluid communication with both the condenser of the main circuit and the condenser of the subcooler circuit.

Abstract: A system (20; 300; 500) comprises: a compressor (22) having a suction port (40) and a discharge port (42); an ejector (32) having a motive flow inlet (50), a suction flow inlet (52), and an outlet (54); a separator (34) having an inlet (72), a vapor outlet (74), and a liquid outlet (76); a first heat exchanger (24); at least one expansion device (28, 30; 520); a second heat exchanger (26); and a plurality of conduits and a plurality of valves (100, 120, 130, 140, 144, 148, 150; 100, 140, 144, 148, 150, 320, 340; 100, 120, 530). The conduits and valves are positioned to provide alternative operation in: a cooling mode; a first heating mode wherein the ejector has a motive flow and a suction flow and where utilizing a first expansion device (30; 520) of the at least one expansion device; and a second heating mode utilizing the first expansion device and wherein the ejector has a suction flow and essentially no motive flow.

Abstract: A heat pump system includes a refrigerant circuit, at least one variable speed compressor operating with a maximum pressure ratio of at least 5.0 and a variable speed range of at least three times (3×), a heat absorption heat exchanger, a heat rejection heat exchanger, an ejector disposed on the refrigerant circuit upstream of the compressor to extend a pressure ratio range and a volumetric flow range of the compressor in the cold climates, a separator disposed downstream of the ejector and upstream of the heat absorption heat exchanger, and at least one variable speed fan configured to move air through the heat rejection heat exchanger to provide a predefined an air discharge temperature greater than 90° F. A two-phase refrigerant is provided to an inlet of the heat absorption heat exchanger with a quality of less than or equal to 0.05.