# US 10,371,423 B2 · Refrigerant balancing in a microchannel coil > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,371,423 B2 - Document ID: US10371423B2 - Status: Granted - Kind: B2 - Application number: 15/436,305 - Filed: 2017-02-17 - Published: 2018-08-23 - Granted: 2019-08-06 - Earliest claimed: 2017-02-17 - Assignees: Trane International Inc. - Applicants: Trane International Inc. - Inventors: Samuel J. Vanden Hogen; George M. Singh; William B. Fox - Web page: https://patentgrep.com/patent/US10371423B2 ## CPC - F25B 6/02: arranged in parallel - F25B 39/00: Evaporators; Condensers - F25B 39/04: Condensers - F25B 40/02: Subcoolers - F25B 41/30: Expansion means; Dispositions thereof - F25B 45/00: Arrangements for charging or discharging refrigerant - F25B 2339/044: Condensers with an integrated receiver - F25B 2500/09: Improving heat transfers - F25B: REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS ## Abstract A refrigeration unit and methods of operating a refrigeration unit for an HVACR system are disclosed. The refrigeration unit includes a refrigerant circuit, including a compressor, a condenser, an expansion device, and an evaporator fluidly connected. The condenser includes a condenser portion and a subcooler portion. A single receiver tank is fluidly connected to an output of the condenser portion and an input of the subcooler portion. A restrictor is fluidly connected to the receiver tank. The restrictor can induce a pressure drop in a working fluid flowing from the subcooler portion. ## Claims ### Claim 1 A refrigeration unit for a heating, ventilation, air conditioning, and refrigeration system, comprising: a refrigerant circuit, including: a compressor, a plurality of condensers connected in parallel and each having a condenser portion and a subcooler portion, an expansion device, and an evaporator fluidly connected; a single receiver tank that is physically separate from and fluidly connected to an output of the condenser portion and an input of the subcooler portion of one of the plurality of condensers; and a restrictor to induce a pressure drop in a working fluid flowing from the subcooler portion of at least one of the plurality of condensers. ### Claim 2 (depends on 1) The refrigeration unit according to claim 1, wherein the restrictor includes a restrictor plate including an aperture therethrough. ### Claim 3 (depends on 1) The refrigeration unit according to claim 1, wherein the restrictor is secured to an inside of a fluid line that fluidly connects the subcooler portion and the expansion device. ### Claim 4 (depends on 1) The refrigeration unit according to claim 1, wherein the restrictor receives working fluid which is a subcooled liquid. ### Claim 5 (depends on 1) The refrigeration unit according to claim 1, wherein the restrictor includes a restrictor plate including an aperture therethrough, and the aperture has a diameter selected to induce the pressure drop, the pressure drop is based on a pressure drop induced by the receiver tank. ### Claim 6 A refrigerant circuit, comprising: a compressor, a plurality of condensers connected in parallel and each having a condenser portion and a subcooler portion, an expansion device, and an evaporator fluidly; a single receiver tank that is physically separate from and fluidly connected to an output of the condenser portion and an input of the subcooler portion of one of the plurality of condensers; and a restrictor for inducing a pressure drop in a working fluid flowing from the subcooler portion of at least one of the plurality of condensers. ### Claim 7 (depends on 6) The refrigerant circuit according to claim 6, wherein the restrictor includes a circular restrictor plate including an aperture therethrough. ### Claim 8 (depends on 6) The refrigerant circuit according to claim 6, wherein the restrictor is secured to an inside of a fluid line that fluidly connects the subcooler portion and the expansion device. ### Claim 9 (depends on 6) The refrigerant circuit according to claim 6, wherein the restrictor includes a restrictor plate including an aperture therethrough, and the aperture has a diameter selected to induce the pressure drop, the pressure drop is based on a pressure drop induced by the receiver tank. ### Claim 10 (depends on 6) The refrigerant circuit according to claim 6, wherein the refrigerant circuit is included in one of a chiller and a rooftop air conditioner. ### Claim 11 A method, comprising: compressing a working fluid by a compressor in a refrigerant circuit; outputting the compressed working fluid to a plurality of condensers connected in parallel and each having a condenser portion and a subcooler portion in the refrigerant circuit, wherein the compressed working fluid is received by the condenser portions of the plurality of condensers; condensing the working fluid in the condenser portions and outputting the condensed working fluid to a single receiver tank disposed fluidly between the condenser portion and the subcooler portion of one of the plurality of condensers; and reducing a pressure of the working fluid output from the subcooler portion after outputting the working fluid from the subcooler portion. ### Claim 12 (depends on 11) The method of claim 11, wherein reducing the pressure of the working fluid includes passing the working fluid through an aperture of a restrictor plate, wherein the aperture has a diameter that is less than a diameter of a fluid line in which the restrictor plate is disposed.