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US 2023/0408168 A1Published application
Hot gas defrost using fluid from high pressure tank
AssigneeHeatcraft Refrigeration Products LLC
InventorShitong Zha
Life of this patent
Estimating the term…
Abstract
A refrigeration system includes pressure-regulating valve positioned between two flash tanks and a heat exchanger is positioned downstream from a medium temperature compressor. After determining that operation of an evaporator in a defrost mode is indicated, the system causes the evaporator to operate in the defrost mode by adjusting the pressure-regulating valve to increase a pressure of a first flash tank relative to a pressure of a second flash tank, allowing flow of refrigerant from the first flash tank to the heat exchanger, and allowing refrigerant heated by the heat exchanger to flow to the first evaporator.
Claims20
A refrigeration system, comprising:
- a plurality of evaporators, each configured to transfer heat from a space to refrigerant;
- one or more medium temperature compressors configured to output compressed refrigerant;
- a first flash tank configured to receive and store cooled refrigerant provided by a gas cooler;
- a second flash tank configured to receive and store a portion of the cooled refrigerant from the first flash tank;
- a pressure-regulating valve disposed in refrigerant conduit coupling the first flash tank to the second flash tank;
- a heat exchanger positioned downstream from the one or more medium temperature compressors and configured, when at least one evaporator of the plurality of evaporators is operated in a defrost mode, to transfer heat from the compressed refrigerant output by the one or more medium temperature compressors to a flow of refrigerant from the first flash tank;
- and a controller communicatively coupled to the pressure-regulating valve, wherein the controller is configured to:
- determine that operation of a first evaporator of the plurality of evaporators in a defrost mode is indicated;
- and
- after determining that operation of the first evaporator in the defrost mode is indicated, cause the first evaporator to operate in the defrost mode by:
- adjusting the pressure-regulating valve to increase a pressure of the first flash tank relative to a pressure of the second flash tank;
- allowing flow of refrigerant from the first flash tank to the heat exchanger;
- and
- allowing refrigerant heated by the heat exchanger to flow to the first evaporator.
11 more elements
A method of operating a refrigeration system, the method comprising:
- operating a first evaporator of a plurality of evaporators in a refrigeration mode;
- determining that operation of the first evaporator in a defrost mode is indicated;
- and
- after determining that operation of the first evaporator in the defrost mode is indicated, causing the first evaporator to operate in the defrost mode by:
- adjusting a pressure-regulating valve disposed in refrigerant conduit coupling a first flash tank to a second flash tank to increase a pressure of the first flash tank relative to a pressure of the second flash tank, wherein the first flash tank is configured to receive and store refrigerant cooled by a gas cooler and the second flash tank is configured to receive and store a portion of the cooled refrigerant from the first flash tank;
- allowing a flow of refrigerant from the first flash tank to a heat exchanger configured to transfer heat from refrigerant output by one or more compressors of the refrigeration system to the flow of refrigerant from the first flash tank to the heat exchanger;
- and
- allowing refrigerant heated by the heat exchanger to flow to the first evaporator.
5 more elements
A controller of a refrigeration system, the controller comprising:
- an input/output interface communicatively coupled to a pressure-regulating valve disposed in refrigerant conduit coupling a first flash tank to a second flash tank to increase a pressure of the first flash tank relative to a pressure of the second flash tank, wherein the first flash tank is configured to receive and store refrigerant cooled by a gas cooler and the second flash tank is configured to receive and store a portion of the cooled refrigerant from the first flash tank;
- and
- a processor configured to:
- determine that operation of a first evaporator of a plurality of evaporators in a defrost mode is indicated;
- and
- after determining that operation of the first evaporator in the defrost mode is indicated, cause the first evaporator to operate in the defrost mode by:
- adjusting the pressure-regulating valve to increase a pressure of the first flash tank relative to a pressure of the second flash tank;
- allowing a flow of refrigerant from the first flash tank to the heat exchanger;
- and
- allowing refrigerant heated by the heat exchanger to flow to the first evaporator.
7 more elements
Dependencies are inferred from the claim text.