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

Claim 0:
1. A refrigeration system, comprising:
an evaporator;
a condenser;
a compressor configured to circulate a refrigerant between the evaporator and the condenser;
a capillary tube positioned downstream from the condenser and configured to receive refrigerant exiting from the condenser, the capillary tube configured to 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 in series with the capillary tube and configured to receive the refrigerant from the capillary tube and provide the refrigerant to the evaporator, the expansion valve adjustable to control a flow rate of the refrigerant through the capillary tube and cause a variable decrease in the measurable thermodynamic property of the refrigerant based at least in part on a refrigeration load, the refrigerant exiting from the condenser passes through the capillary tube before being supplied to the expansion valve;
a bypass line arranged in parallel with the expansion valve and configured to allow a first portion of the refrigerant to bypass the expansion valve while allowing a second portion of the refrigerant to pass through the expansion valve, the bypass line comprising a bleeder system configured to bypass the first portion of the refrigerant in the bypass line at an order of magnitude less than the second portion of the refrigerant passed to the expansion valve;
a sensor positioned downstream of the capillary tube and configured to measure a temperature of the refrigerant and generate a signal corresponding to the measured temperature of the refrigerant; 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.