Refrigeration system with efficient expansion device control, liquid refrigerant return, oil return, and evaporator defrost
AssigneeHill Phoenix, Inc.
InventorsSenthilkumar Kandappa Goundar Shanmugam, Manu Mital
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Abstract
A refrigeration system includes an evaporator configured to receive a flow of refrigerant and transfer heat into the refrigerant within the evaporator to provide cooling for a temperature-controlled space, an expansion valve operable to modulate the flow of refrigerant into the evaporator, a liquid level sensor configured to measure a level of liquid accumulated within a component of the refrigeration system, and a controller configured to operate the expansion valve to increase the flow of refrigerant into the evaporator or decrease the flow of refrigerant into the evaporator based on the level of liquid measured by the liquid level sensor.
Claims20
A controller operatively coupled to a refrigeration system, the controller configured to perform operations comprising:
- determining a level of liquid refrigerant accumulated within the refrigeration system by subtracting a level of oil from a total level of oil and liquid refrigerant;
- and
- based on the level of liquid refrigerant, operating an expansion valve to control a flow of refrigerant into an evaporator configured to provide cooling for a temperature-controlled space.
A controller operatively coupled to a refrigeration system, the controller configured to perform operations comprising:
- determining a level of liquid refrigerant accumulated within a liquid/vapor separator of the refrigeration system by subtracting a level of oil from a total level of oil and liquid refrigerant;
- and
- in response to at least one of i) the level of liquid refrigerant accumulated within the liquid/vapor separator exceeding a threshold liquid level or ii) a calculated value based on the level of liquid refrigerant accumulated within the liquid/vapor separator exceeding the threshold liquid level, the level of liquid refrigerant comprising the total level of oil and liquid refrigerant accumulated within the liquid/vapor separator, initiating a liquid refrigerant return process in the refrigeration system.
A controller configured to perform operations comprising:
- measuring a level of liquid accumulated within a liquid/vapor separator of a refrigeration system;
- measuring a level of oil accumulated within the liquid/vapor separator;
- determining that at least one of i) the level of liquid accumulated within the liquid/vapor separator exceeds a threshold value or ii) a calculated value based on the level of liquid accumulated within the liquid/vapor separator exceeds the threshold value, the level of liquid comprising a total level of oil and liquid refrigerant accumulated within the liquid/vapor separator;
- in response to said determination, determining a level of liquid refrigerant accumulated within the liquid/vapor separator by subtracting the level of oil from the total level of oil and liquid refrigerant;
- initiating a liquid refrigerant return process in response to the level of liquid refrigerant accumulated within the liquid/vapor separator exceeding the threshold value;
- preventing vapor refrigerant from exiting the liquid/vapor separator;
- connecting the liquid/vapor separator to a high pressure source to pressurize vapor refrigerant and liquid refrigerant within the liquid/vapor separator;
- and
- opening a liquid refrigerant return valve fluidly coupled to the liquid/vapor separator, causing the liquid refrigerant within the liquid/vapor separator to exit the liquid/vapor separator and return to an evaporator of the refrigeration system.
Dependencies are inferred from the claim text.