# US 8,769,968 B2 · Refrigerant system and method for controlling the same > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 8,769,968 B2 - Document ID: US8769968B2 - Status: Granted - Kind: B2 - Application number: 13/240,717 - Filed: 2011-09-22 - Published: 2012-03-29 - Granted: 2014-07-08 - Earliest claimed: 2010-09-27 - Assignees: LG Electronics Inc. - Applicants: Hojong Jeong; Baikyoung Chung; Jaehwa Jung; Yongcheol Sa; Byungsoon Kim - Inventors: Hojong Jeong; Baikyoung Chung; Jaehwa Jung; Yongcheol Sa; Byungsoon Kim - Web page: https://patentgrep.com/patent/US8769968B2 ## CPC - F25B 45/00: Arrangements for charging or discharging refrigerant - F25B 13/00: Compression machines, plants or systems, with reversible cycle (defrosting cycles F25B47/02) - F25B 2313/02741: using one four-way valve - F25B 2313/0315: Temperature sensors near the outdoor heat exchanger - F25B 2400/075: with parallel compressors - F25B 2400/13: Economisers - F25B 2400/16: Receivers - F25B 2600/05: Refrigerant levels - F25B 2700/04: Refrigerant level - F25B 2700/1931: Discharge pressures - F25B 2700/21152: at the discharge side of the compressor - F25B: REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS ## Abstract A refrigerant system and a method for controlling the same are provided. A refrigerant system includes: an outdoor heat exchanger disposed in an operating loop of the refrigerant system and configured to perform a heat exchange between outdoor air and a refrigerant; a compressor disposed in the operating loop and configured to compress the refrigerant; an indoor heat exchanger disposed in the operating loop and configured to perform a heat exchange between indoor air and the refrigerant; an expander disposed in the operating loop and configured to expand the refrigerant; a refrigerant storage connected to the operating loop and configured to receive and store the refrigerant from and discharge the refrigerant to the operating loop; and a refrigerant storage controller configured to control a total amount of refrigerant in the operating loop based on an indoor air conditioning load and an amount of the stored refrigerant. ## Claims ### Claim 1 A refrigerant system, comprising: an outdoor heat exchanger disposed in an operating loop of the refrigerant system and configured to perform a heat exchange between outdoor air and a refrigerant; a compressor disposed in the operating loop and configured to compress the refrigerant; an indoor heat exchanger disposed in the operating loop and configured to perform a heat exchange between indoor air and the refrigerant; an expander disposed in the operating loop and configured to expand the refrigerant; a refrigerant storage connected to the operating loop and configured to receive and store the refrigerant from and discharge the refrigerant to the operating loop; and a refrigerant storage controller configured to control a total amount of refrigerant in the operating loop based on an indoor air conditioning load and an amount of the stored refrigerant, and wherein if the indoor air conditioning load is less than a reference load and if the amount of the stored refrigerant is greater than a first reference amount, then the refrigerant storage controller controls the total amount of refrigerant in the operating loop to be increased. ### Claim 2 (depends on 1) The refrigerant system of claim 1, wherein if the indoor air conditioning load is less than a reference load and if the amount of the stored refrigerant is less than a first reference amount, then the refrigerant storage controller controls the total amount of refrigerant in the operating loop to be maintained. ### Claim 3 (depends on 1) The refrigerant system of claim 1, wherein if the indoor air conditioning load is greater than a reference load and if the amount of the stored refrigerant is less than a second reference amount, then the refrigerant storage controller controls the total amount of refrigerant in the operating loop to be decreased. ### Claim 4 (depends on 1) The refrigerant system of claim 1, wherein if the indoor air conditioning load is greater than a reference load and if the amount of the stored refrigerant is greater than a second reference amount, then the refrigerant storage controller controls the total amount of refrigerant in the operating loop to be maintained. ### Claim 5 (depends on 1) The refrigerant system of claim 1, wherein if the indoor air conditioning load is neither less than nor greater than a second reference load, then the refrigerant storage controller controls the total amount of refrigerant in the operating loop to be maintained. ### Claim 6 A refrigerant system, comprising: an outdoor heat exchanger disposed in an operating loop of the refrigerant system and configured to perform a heat exchange between outdoor air and a refrigerant; a compressor disposed in the operating loop and configured to compress the refrigerant; an indoor heat exchanger disposed in the operating loop and configured to perform a heat exchange between indoor air and the refrigerant; an expander disposed in the operating loop and configured to expand the refrigerant; a refrigerant storage connected to the operating loop and configured to receive and store the refrigerant from and discharge the refrigerant to the operating loop; an inflow controller configured to control an amount of refrigerant received by the refrigerant storage; a discharge controller configured to control an amount of refrigerant discharged from the refrigerant storage; and a refrigerant storage controller configured to control inflow controller and the discharge controller based on an indoor air conditioning load and an amount of the stored refrigerant, and wherein if the indoor air conditioning load is less than a reference load and if the amount of the stored refrigerant is greater than a first reference amount, then the refrigerant storage controller controls the discharge controller to be opened and controls the inflow controller to be closed. ### Claim 7 (depends on 6) The refrigerant system of claim 6, wherein if the indoor air conditioning load is less than a reference load and if the amount of the stored refrigerant is less than a first reference amount, then the refrigerant storage controller controls the discharge controller and the inflow controller to be closed. ### Claim 8 (depends on 6) The refrigerant system of claim 6, wherein if the indoor air conditioning load is greater than a reference load and if the amount of the stored refrigerant is less than a second reference amount, then the refrigerant storage controller controls the discharge controller to be closed and the inflow controller to be opened. ### Claim 9 (depends on 6) The refrigerant system of claim 6, wherein if the indoor air conditioning load is greater than a reference load and if the amount of the stored refrigerant is greater than a second reference amount, then the refrigerant storage controller controls the discharge controller and the inflow controller to be closed. ### Claim 10 (depends on 6) The refrigerant system of claim 6, wherein if the indoor air conditioning load is neither less than nor greater than a reference load, then the refrigerant storage controller controls the discharge controller and the inflow controller to be closed. ### Claim 11 A refrigerant system comprising: an outdoor heat exchanger disposed in an operating loop of the refrigerant system and configured to perform a heat exchange between outdoor air and a refrigerant; a compressor disposed in the operating loop and configured to compress the refrigerant; an indoor heat exchanger disposed in the operating loop and configured to perform a heat exchange between indoor air and the refrigerant; an expander disposed in the operating loop and configured to expand the refrigerant; a refrigerant storage connected to the operating loop and configured to receive the refrigerant from and discharge the refrigerant to the operating loop; a refrigerant sensor configured to sense an amount of refrigerant stored in the refrigerant storage; and a supercooling sensor configured to sense a supercooling amount of the refrigerant flowing from the outdoor heat exchanger, and wherein if the supercooling amount sensed by the supercooling sensor is less than a reference supercooling amount and if the amount of refrigerant sensed by the refrigerant sensor is greater than a first reference amount, then a total amount of refrigerant in the operating loop is increased. ### Claim 12 (depends on 11) The refrigerant system of claim 11, further comprising a high pressure sensor configure to sense a pressure of the refrigerant flowing from a discharge side of the compressor. ### Claim 13 (depends on 12) The refrigerant system of claim 12, wherein if the pressure sensed by the high pressure sensor is less than a reference pressure and if the amount of refrigerant sensed by the refrigerant sensor is greater than a first reference amount, then a total amount of refrigerant in the operating loop is increased. ### Claim 14 (depends on 12) The refrigerant system of claim 12, wherein if the pressure sensed by the high pressure sensor is less than a reference pressure and if the amount of refrigerant sensed by the refrigerant sensor is less than a first reference amount, then a total amount of refrigerant in the operating loop is maintained. ### Claim 15 (depends on 12) The refrigerant system of claim 12, wherein if the pressure sensed by the high pressure sensor is greater than a reference pressure and if the amount of refrigerant sensed by the refrigerant sensor is less than a second reference amount, then a total amount of refrigerant in the operating loop is decreased. ### Claim 16 (depends on 12) The refrigerant system of claim 12, wherein if the pressure sensed by the high pressure sensor is greater than a reference pressure and if the amount of refrigerant sensed by the refrigerant sensor is greater than a second reference amount, then a total amount of refrigerant in the operating loop is maintained. ### Claim 17 (depends on 12) The refrigerant system of claim 12, wherein if the pressure sensed by the high pressure sensor is neither less than nor greater than a reference pressure, then a total amount of refrigerant in the operating loop is maintained. ### Claim 18 (depends on 11) The refrigerant system of claim 11, wherein if the supercooling amount sensed by the supercooling sensor is less than a reference supercooling amount and if the amount of refrigerant sensed by the refrigerant sensor is less than a first reference amount, then a total amount of refrigerant in the operating loop is maintained. ### Claim 19 (depends on 11) The refrigerant system of claim 11, wherein if the supercooling amount sensed by the supercooling sensor is greater than a reference supercooling amount and if the amount of refrigerant sensed by the refrigerant sensor is less than a second reference amount, then a total amount of refrigerant in the operating loop is decreased. ### Claim 20 (depends on 11) The refrigerant system of claim 11, wherein if the supercooling amount sensed by the supercooling sensor is greater than a reference supercooling amount and if the amount of refrigerant sensed by the refrigerant sensor is greater than a second reference amount, then a total amount of refrigerant in the operating loop is maintained. ### Claim 21 (depends on 11) The refrigerant system of claim 11, wherein if the supercooling amount sensed by the supercooling sensor is neither less than nor greater than the reference supercooling amount, then a total amount of refrigerant in the operating loop is maintained. ### Claim 22 (depends on 11) The refrigerant system of claim 11, further comprising a high pressure sensor configure to sense a pressure of the refrigerant flowing from a discharge side of the compressor, wherein if the supercooling amount sensed by the supercooling sensor is less than a reference supercooling amount, if the sensed pressure is less than a safety pressure and if the amount of refrigerant sensed by the refrigerant sensor is greater than a first reference amount, then a total amount of refrigerant in the operating loop is increased. ### Claim 23 (depends on 22) The refrigerant system of claim 22, wherein if the supercooling amount sensed by the supercooling sensor is less than the reference supercooling amount and if the sensed pressure is greater than a safety pressure, the total amount of refrigerant in the operating loop is maintained. ### Claim 24 (depends on 12) The refrigerant system of claim 12, wherein the refrigerant sensor includes a plurality of level sensors to sense a plurality of levels of the refrigerant stored in the refrigerant storage. ### Claim 25 (depends on 24) The refrigerant system of claim 24, wherein a first of the plurality of sensors is provided at a low position in an internal space of the refrigerant storage and a second the plurality of sensors is provided at a high position in the internal space of the refrigerant storage. ### Claim 26 (depends on 25) The refrigerant system of claim 25, wherein a third of the plurality of sensors is provided in the internal space of the refrigerant storage at a position between the low position of the first sensor and the high position of the second sensor.