Patent ID: 11892210
Assignee: HILL PHOENIX, INC.
Field: Thermal processes and apparatus (Mechanical engineering)
Classification: CPC F  Y | IPC F

Claim 14:
15. A valve assembly for a refrigeration system, the valve assembly comprising:
a capillary tube configured to receive all refrigerant exiting from a condenser of the refrigeration system and cause a fixed decrease in a measurable thermodynamic property of the refrigerant as a result of a geometry of the capillary tube;
an expansion valve positioned downstream of the capillary tube and configured to receive the refrigerant from the capillary tube and provide the refrigerant to an evaporator of the refrigeration system, the expansion valve adjustable to cause a variable decrease in the measureable thermodynamic property of the refrigerant to accommodate varying refrigeration loads, the expansion valve positioned within the valve assembly such that refrigerant passing through the expansion valve first passes through the capillary tube;
a bypass line arranged in parallel with the expansion valve and configured to allow a portion of the refrigerant to bypass the expansion valve while requiring a remaining amount of the refrigerant to pass through the expansion valve, the bypass line comprising a bleeder system configured to bypass the portion of the refrigerant in the bypass line at an order of magnitude less than the remaining amount of the refrigerant to pass through the expansion valve;
a sensor positioned downstream of the evaporator and configured to measure a temperature of the refrigerant upon exiting the evaporator; and
a controller in communication with the sensor and configured to:
determine an amount of superheat in the refrigerant at an outlet of the evaporator based on the measured temperature;
compare the amount of superheat to a superheat setpoint; and
drive the amount of superheat to the superheat setpoint by adjusting a decrease in the measurable thermodynamic property of the of the refrigerant by modulating the expansion valve, the decrease in the measurable thermodynamic property of the refrigerant being a sum of the fixed decrease in the measurable thermodynamic property of the refrigerant caused by the capillary tube and the variable decrease in the measurable thermodynamic property of the refrigerant caused by the expansion valve.