# US 12,111,085 B2 · Refrigerant circuit with reduced environmental impact > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 12,111,085 B2 - Document ID: US12111085B2 - Status: Granted - Kind: B2 - Application number: 18/396,660 - Filed: 2023-12-26 - Published: 2024-04-18 - Granted: 2024-10-08 - Earliest claimed: 2021-07-23 - Assignees: Refrigerated Solutions Group LLC - Applicants: Refrigerated Solutions Group LLC - Inventors: William Craig Larson; Narasimha Sapta Sailesh Krovvidi; Nicholas Scott Huppert; Brian McCain - Web page: https://patentgrep.com/patent/US12111085B2 ## CPC - F25B 49/02: for compression type machines, plants or systems - F25B 5/02: arranged in parallel - F25B 2400/06: Several compression cycles arranged in parallel - F25B 2400/12: Inflammable refrigerants - F25B 2500/18: Optimization, e.g. high integration of refrigeration components - F25B 2600/0251: with on-off operation - F25B 2700/2104: of an indoor room or compartment - F25B: REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS ## Abstract A refrigeration system configured to receive a refrigerant is provided, as well as a walk-in refrigeration unit configured to utilize said system. The refrigeration system comprises: a power source, a condenser unit, an evaporation unit, a plurality of compressors, wherein each of the plurality of compressors is communicably coupled to the condenser unit, and a plurality of expansion devices, wherein each of the plurality of expansion devices is communicably coupled to the evaporation unit. The system is configured to receive an A3 refrigerant having a Global Warming Potential (GWP) value less than 10. ## Claims ### Claim 1 A walk-in refrigeration unit comprising: one or more refrigeration systems, each of the one or more refrigeration systems operatively coupled to a walk-in refrigeration unit, each of the one or more refrigeration systems configured to receive a refrigerant and a single source of power, wherein each refrigeration system comprises: a condenser; a plurality of compressors, wherein each of the plurality of compressors comprises a compressor input and a compressor output and wherein each compressor output is communicably coupled to the condenser; an evaporator; and propane refrigerant with a maximum charge of 5.3 ounces per each of the plurality of compressors. ### Claim 2 (depends on 1) The walk-in refrigeration unit of claim 1, further comprises a plurality of expansion devices, wherein each of the plurality of expansion devices comprises an expansion device input and an expansion device output and wherein each expansion device output is communicably coupled to one of a plurality of evaporator inputs of the evaporator. ### Claim 3 (depends on 1) The walk-in refrigeration unit of claim 1, wherein the condenser comprises a plurality of condenser inputs and condenser outputs, wherein each condenser output is communicably coupled to one of the plurality of expansion device inputs. ### Claim 4 (depends on 1) The refrigeration system of claim 1, further comprising a controller, wherein the controller is configured to activate the plurality of compressors sequentially, or to activate the plurality of compressors based on a sensed temperature, a change in temperature, or a temperature threshold. ### Claim 5 (depends on 1) The walk-in refrigeration unit of claim 1, wherein a combined refrigeration capacity of the one or more refrigeration systems is equivalent to a total refrigeration capacity of the walk-in refrigeration unit. ### Claim 6 (depends on 1) The walk-in refrigeration unit of claim 1, wherein the evaporator is positioned inside of a temperature regulated environment and the condenser is positioned outside of the temperature-regulated environment. ### Claim 7 A method of cooling a walk-in refrigeration unit, the method comprising: providing one or more refrigeration systems, wherein each refrigeration system comprises: a condenser; a plurality of compressors, wherein each of the plurality of compressors comprises a compressor input and a compressor output and wherein each compressor output is communicably coupled to the condenser; and propane refrigerant with a maximum charge of 5.3 ounces per each of the plurality of compressors; an evaporator; wherein the one or more refrigeration systems provides cooling to the walk-in refrigeration unit. ### Claim 8 (depends on 7) The method of claim 7, wherein each of the one or more refrigeration system further comprises a plurality of expansion devices, wherein each of the plurality of expansion devices comprises an expansion device input and an expansion device output and wherein each expansion device output is communicably coupled to one of a plurality of evaporator inputs of the evaporator. ### Claim 9 (depends on 7) The method of claim 7, further comprising activating, via a controller, the plurality of compressors sequentially, or based on a sensed temperature. ### Claim 10 (depends on 7) The method of claim 7, wherein the evaporator of at least one of the one or more refrigeration systems is positioned inside of a temperature regulated environment and the condenser of at least one of the one or more refrigeration systems is positioned outside of the temperature-regulated environment. ### Claim 11 A walk-in refrigeration unit comprising: one or more refrigeration systems configured to receive power from a single source, wherein each refrigeration system comprises: a single condenser coupled to the power source; a plurality of compressors, wherein each of the plurality of compressors comprises a compressor input and a compressor output and wherein each compressor output is communicably coupled to the condenser; an A3 refrigerant with a maximum charge of 5.3 ounces per each of the plurality of compressors; a plurality of expansion devices communicably coupled to the condenser; and a single evaporator communicably coupled to the plurality of expansion devices. ### Claim 12 (depends on 11) The walk-in refrigeration unit of claim 11, wherein the A3 refrigerant is propane. ### Claim 13 (depends on 11) The walk-in refrigeration unit of claim 11, wherein the single evaporator is positioned inside of a temperature regulated environment and the single condenser is positioned outside of the temperature-regulated environment.