# US 10,767,909 B2 · Thermal storage of carbon dioxide system for power outage > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,767,909 B2 - Document ID: US10767909B2 - Status: Granted - Kind: B2 - Application number: 15/667,194 - Filed: 2017-08-02 - Published: 2019-02-07 - Granted: 2020-09-08 - Earliest claimed: 2017-08-02 - Assignees: Heatcraft Refrigeration Products LLC - Applicants: Heatcraft Refrigeration Products LLC - Inventors: Shitong Zha; Fardis Najafifard; Xi Sun - Web page: https://patentgrep.com/patent/US10767909B2 ## CPC - F25B 9/008: {the refrigerant being carbon dioxide} - F25B 1/10: with multi-stage compression (with cascade operation F25B7/00) - F25B 31/006: {Cooling of compressor or motor} - F25B 5/02: arranged in parallel - F25B 41/39: Dispositions with two or more expansion means arranged in series, i.e. multi-stage expansion, on a refrigerant line leading to the same evaporator - F25B 2309/06: Compression machines, plants or systems characterised by the refrigerant being carbon dioxide - F25B 2400/23: Separators - F25B 2500/07: Exceeding a certain pressure value in a refrigeration component or cycle - F25B 2600/2509: Economiser valves - F25B: REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS ## Abstract A system includes a high side heat exchanger, a flash tank, a first load, a second load, and a thermal storage tank. The high side heat exchanger is configured to remove heat from a refrigerant. The flash tank is configured to store the refrigerant from the high side heat exchanger and discharge a flash gas. The first load is configured to use the refrigerant from the flash tank to remove heat from a first space proximate to the first load. The second load is configured to use the refrigerant from the flash tank to remove heat from a second space proximate to the second load. The thermal storage tank is configured, when a power outage is determined to be occurring, to receive the flash gas from the flash tank, and remove heat from the flash gas. ## Claims ### Claim 1 A system comprising: a high side heat exchanger configured to remove heat from a refrigerant; a flash tank configured to: store the refrigerant from the high side heat exchanger; and discharge a flash gas; a first load configured to use the refrigerant from the flash tank to remove heat from a first space proximate to the first load; a second load configured to use the refrigerant from the flash tank to remove heat from a second space proximate to the second load; a first compressor configured to compress the refrigerant from the first load; and a second compressor configured to compress the refrigerant from the second load and the first compressor; and a thermal storage tank configured, when the system does not have power, to: receive the flash gas from the flash tank; remove heat from the flash gas, thereby condensing the flash gas to a condensed liquid; and direct the condensed liquid to the flash tank; and wherein the thermal storage tank is further configured, when the system has power, to: receive the refrigerant from the flash tank; transfer heat from the thermal storage tank to the refrigerant, thereby heating the refrigerant; and direct the heated refrigerant to the second compressor. ### Claim 2 (depends on 1) The system of claim 1, the second compressor further configured, when the system has power, to compress the heated refrigerant from the thermal storage tank. ### Claim 3 (depends on 1) The system of claim 1, wherein the first space is at a lower temperature than the second space. ### Claim 4 A method comprising: removing heat from a first space proximate to a first load using a refrigerant from a flash tank; removing heat from a second space proximate to a second load using the refrigerant from the flash tank; compressing the refrigerant from the first load using a first compressor; compressing the refrigerant from the second load using a second compressor; removing heat from the refrigerant using a high side heat exchanger; storing the refrigerant from the high side heat exchanger in the flash tank; discharging the flash gas from the flash tank; when the system does not have power: removing heat from the flash gas using a thermal storage tank, thereby condensing the flash gas to a condensed liquid; and directing the condensed liquid to the flash tank; when the system has power: directing the refrigerant from the flash tank to the thermal storage tank; transferring heat from the thermal storage tank to the refrigerant, thereby heating the refrigerant; and directing the heated refrigerant from the thermal storage tank to the second compressor. ### Claim 5 (depends on 4) The method of claim 4, further comprising, when the system has power, compressing the heated refrigerant from the thermal storage tank using the second compressor. ### Claim 6 (depends on 4) The method of claim 4, wherein the first space is at a lower temperature than the second space. ### Claim 7 A system comprising: a flash tank configured to: store a refrigerant; and discharge a flash gas; a first load configured to use the refrigerant from the flash tank to remove heat from a first space proximate to the first load; a second load configured to use the refrigerant from the flash tank to remove heat from a second space proximate to the second load; a first compressor configured to compress the refrigerant from the first load; and a second compressor configured to compress the refrigerant from the second load and the first compressor; and a thermal storage tank configured, when the system does not have power, to: receive the flash gas from the flash tank; remove heat from the flash gas, thereby condensing the flash gas to a condensed liquid; and direct the condensed liquid to the flash tank; and wherein the thermal storage tank is configured, when the system has power, to: receive the refrigerant from the flash tank; transfer heat from the thermal storage tank to the refrigerant, thereby heating the refrigerant; and direct the heated refrigerant to the second compressor. ### Claim 8 (depends on 7) The system of claim 7, further comprising the second compressor further configured, when the system has power, to compress the heated refrigerant from the thermal storage tank. ### Claim 9 (depends on 7) The system of claim 7, wherein the first space is at a lower temperature than the second space.