# US 9,752,801 B2 · Ejector cycle > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 9,752,801 B2 - Document ID: US9752801B2 - Status: Granted - Kind: B2 - Application number: 13/703,736 - Filed: 2011-07-20 - Published: 2013-05-23 - Granted: 2017-09-05 - Earliest claimed: 2010-07-23 - Assignees: Carrier Corporation - Applicants: Parmesh Verma; Thomas D. Radcliff; Frederick J. Cogswell - Inventors: Parmesh Verma; Thomas D. Radcliff; Frederick J. Cogswell - Web page: https://patentgrep.com/patent/US9752801B2 ## CPC - F25B 1/06: with compressor of jet type, e.g. using liquid under pressure ({F25B1/005,} F25B1/10 take precedence) - F25B 1/10: with multi-stage compression (with cascade operation F25B7/00) - F25B 40/00: Subcoolers, desuperheaters or superheaters - F25B 41/00: Fluid-circulation arrangements - F25B 2341/0011: Ejectors with the cooled primary flow at reduced or low pressure - F25B 2341/0015: using two or more ejectors - F25B: REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS ## Abstract A system (200; 250; 270) has first (220) and second (222) compressors, a heat rejection heat exchanger (30), first (38) and second (202) ejectors, a heat absorption heat exchanger (64), and a separator (48). The heat rejection heat exchanger is coupled to the second compressor to receive refrigerant compressed by the second compressor. The first ejector has a primary inlet (40) coupled to the heat rejection exchanger to receive refrigerant, a secondary inlet (42), and an outlet (44). The second ejector has a primary inlet (204) coupled to the heat rejection heat exchanger to receive refrigerant, a secondary inlet (206), and an outlet (208). The separator has an inlet (50) coupled to the outlet (44) of the first ejector to receive refrigerant from the first ejector. The separator has a gas outlet (54) coupled to the secondary inlet (206) of the second ejector via the first compressor (220) to deliver refrigerant to the second ejector. The separator has a liquid outlet (52) coupled to the secondary inlet (42) of the first ejector via the heat absorption heat exchanger to deliver refrigerant to the first ejector. ## Claims ### Claim 1 A system (200; 250; 270) comprising: a first compressor (220) and a second compressor (221); a heat rejection heat exchanger (30) coupled to the second compressor to receive refrigerant compressed by the second compressor; a first ejector (38) having: a primary inlet (40) coupled to the heat rejection heat exchanger to receive refrigerant; a secondary inlet (42); and an outlet (44); a heat absorption heat exchanger (64); a second ejector (202) having: a primary inlet (204) coupled to the heat rejection heat exchanger to receive refrigerant; a secondary inlet (206); and an outlet (208) coupled to the second compressor to deliver refrigerant to the second compressor; compressor, the second compressor positioned downstream of the outlet of the second ejector to compress refrigerant passing from the outlet of the second ejector to the heat rejection heat exchanger; and a separator (48) having: an inlet (50) coupled to the outlet of the first ejector to receive refrigerant from the first ejector; a gas outlet (54) coupled to the secondary inlet of the second ejector via the first compressor to deliver refrigerant to the second ejector; and a liquid outlet (52) coupled to the secondary inlet of the first ejector via the first heat absorption heat exchanger to deliver refrigerant to the first ejector. ### Claim 2 (depends on 1) The system of claim 1 further comprising: a controllable expansion device (70) between the separator liquid outlet and the heat absorption heat exchanger. ### Claim 3 (depends on 1) The system of claim 1 wherein: the separator is a gravity separator; a single phase gas flow exits the gas outlet; and a single phase liquid flow exits the liquid outlet. ### Claim 4 (depends on 1) The system of claim 1 wherein: the system has no other separator. ### Claim 5 (depends on 1) The system of claim 1 wherein: the system has no other ejectors other than the first ejector and the second ejector. ### Claim 6 (depends on 1) The system of claim 1 further comprising: a controllable valve (240) having: an open condition permitting flow from the heat rejection heat exchanger to the second ejector primary inlet; and a closed condition preventing said flow. ### Claim 7 (depends on 1) The system of claim 1 further comprising an economizer heat exchanger (252) having: a heat rejection leg (256) positioned between: a) the heat rejection heat exchanger; and b) the inlet of the first ejector; and a heat absorption leg (254) positioned between: c) the outlet of the second ejector; and b) the second compressor. ### Claim 8 (depends on 1) The system of claim 1 wherein: refrigerant comprises at least 50% carbon dioxide, by weight. ### Claim 9 (depends on 1) The system of claim 1 wherein: the first and second compressors are separately powered. ### Claim 10 (depends on 1) The system of claim 1 wherein: the first and second compressors are separate stages of a single compressor. ### Claim 11 (depends on 1) The system of claim 1 wherein: a line 210 from an outlet (34) of the heat rejection heat exchanger splits into a first branch (210-1) and a second branch (210-2) respectively feeding the first ejector primary inlet (40) and the second ejector primary inlet (204) without passing through the first compressor or the second compressor. ### Claim 12 (depends on 1) The system of claim 1 wherein: a refrigerant flowpath passes from the first compressor through the second ejector and to the second compressor before reaching the heat rejection heat exchanger. ### Claim 13 (depends on 1) A method for operating the system of claim 1 comprising running the system in a first mode wherein: refrigerant received from the second compressor by the heat rejection heat exchanger rejects heat in the heat rejection heat exchanger to produce initially cooled refrigerant; the initially cooled refrigerant splits into a first primary flow received by the first ejector primary inlet and a second primary flow received by the second ejector primary inlet; in the respective first ejector and second ejector, the first primary flow and second primary flow respectively join with a first secondary inlet flow and second secondary inlet flow to respectively form a first outlet flow and a second outlet flow; the first outlet flow is separated in the separator into a first flow and a second flow, the first flow becoming the first secondary inlet flow and the second flow becoming the second secondary inlet flow; the first flow passes through the first heat absorption heat exchanger; the second flow passes through the first compressor and is compressed before reaching the second ejector secondary inlet; and the second secondary inlet flow and second primary flow merge in the second ejector to form the second outlet flow and pass to the second compressor where the second outlet flow is compressed. ### Claim 14 (depends on 13) The method of claim 13 wherein: the first flow has a higher proportion of liquid relative to gas than does the second flow. ### Claim 15 (depends on 13) The method of claim 13 further comprising operating in a second mode wherein: the second primary flow is prevented. ### Claim 16 (depends on 15) The method of claim 15 wherein, in the second mode, flow passes from the first compressor through the second ejector secondary inlet and through the second ejector to the second compressor to be compressed and delivered to the heat rejection heat exchanger. ### Claim 17 (depends on 13) The method of claim 13 wherein: operation in the first mode is controlled by a controller (140) programmed to control operation of the first ejector, the second ejector, the first compressor, the second compressor, and a controllable expansion device (70) between the separator liquid outlet and the heat absorption heat exchanger; the first primary flow and second primary flow consist essentially of supercritical or liquid states; and the first secondary inlet flow and second secondary inlet flow consist essentially of gas. ### Claim 18 (depends on 13) The method of claim 13 wherein, in the first mode, the entire second outlet flow passes to the second compressor. ### Claim 19 A system (200; 250; 270) comprising: a first compressor (220) and a second compressor (221); a heat rejection heat exchanger (30) positioned downstream of the second compressor and coupled to the second compressor to receive refrigerant compressed by the second compressor; a first ejector (38) having: a primary inlet (40) coupled to the heat rejection heat exchanger to receive refrigerant; a secondary inlet (42); and an outlet (44); a heat absorption heat exchanger (64); a separator (48) having: an inlet (50) coupled to the outlet of the first ejector to receive refrigerant from the first ejector; a gas outlet (54) coupled to the first compressor to deliver refrigerant to the first compressor; and a liquid outlet (52) coupled to the secondary inlet of the first ejector via the first heat absorption heat exchanger to deliver refrigerant to the first ejector; and means (202, 240) for controllably providing a pressure lift between the first compressor and the second compressor. ### Claim 20 (depends on 19) The system of claim 19 wherein: the means comprises a second ejector. ### Claim 21 (depends on 20) The system of claim 20 wherein: the second ejector has, in at least a first mode: a suction port (206) coupled to the first compressor to receive refrigerant compressed by the first compressor; and an outlet (208) coupled to the second compressor to deliver refrigerant to the second compressor. ### Claim 22 (depends on 21) The system of claim 21 wherein: the second ejector outlet is coupled to the second compressor inlet via a leg (254) of a heat exchanger (252); and a second leg (256) of the heat exchanger (252), in heat exchange relation with the first leg (254) is between the heat rejection heat exchanger and the primary inlet of the first ejector. ### Claim 23 (depends on 21) The system of claim 21 further comprising: a valve (260) positioned to selectively switch between: said first mode; and a second mode wherein a flow to the second ejector suction port is blocked and a bypass flow is provided from the first compressor to the second compressor bypassing the second ejector. ### Claim 24 (depends on 1) The system of claim 1 wherein: the system has no other ejectors other than the first ejector and the second ejector. ### Claim 25 (depends on 19) The system of claim 19 wherein the second ejector has a primary inlet (204) on a flowpath branching from a flowpath from the heat rejection heat exchanger to the primary inlet of the first ejector. ### Claim 26 A system (200; 250; 270) comprising: a reciprocating compressor comprising: a first section (220) and a second section (221); a heat rejection heat exchanger (30) coupled to the second section to receive refrigerant compressed by the second section; a first ejector (38) having: a primary inlet (40) coupled to the heat rejection heat exchanger to receive refrigerant; a secondary inlet (42); and an outlet (44); a heat absorption heat exchanger (64); a second ejector (202) having: a primary inlet (204) coupled to the heat rejection heat exchanger to receive refrigerant; a secondary inlet (206); and an outlet (208) coupled to the second section to deliver refrigerant to the second section; and a separator (48) having: an inlet (50) coupled to the outlet of the first ejector to receive refrigerant from the first ejector; a gas outlet (54) coupled to the secondary inlet of the second ejector via the first section to deliver refrigerant to the second ejector; and a liquid outlet (52) coupled to the secondary inlet of the first ejector via the heat absorption heat exchanger to deliver refrigerant to the first ejector.