Parallel capillary expansion tube systems and methods

A method for operating a cooling system, comprising:

• sensing a temperature and a pressure of refrigerant output from an evaporator of the cooling system at a first location of a suction line using one or more sensors communicatively coupled to an expansion valve;
• adjusting flow rate of a first portion of refrigerant flowing through a first fluid line of a subcooling heat exchange assembly to a second location of a suction line based on the sensed temperature and the sensed pressure, wherein the subcooling heat exchange assembly comprises the first fluid line and a second fluid line each fluidly coupled to an output of a condenser of the cooling system, wherein adjusting the flow rate of the first portion of refrigerant comprises adjusting a position of the expansion valve to a more open position when the temperature and pressure of the refrigerant output from the evaporator at the first location increase, wherein the first location is downstream of the second location, and wherein the flow rate of the first portion of refrigerant increases when the expansion valve is opened to the more open position;
• and
• affecting an adjustment of a choked mass flow rate of the refrigerant through a plurality of parallel capillary tubes, wherein the plurality of capillary tubes is fluidly coupled to the output of the second fluid line of the subcooling heat exchange assembly.

A cooling system, comprising:

• a subcooling heat exchange assembly comprising:
• a first fluid line configured to be fluidly coupled to an output of a condenser to enable a first portion of refrigerant output from the condenser to flow through the first fluid line;
• a second fluid line configured to be fluidly coupled to the output of the condenser to enable a second portion of the refrigerant output from the condenser to flow through the second fluid line to a suction line at a first location of the suction line, wherein the first portion of refrigerant is a greater portion of the refrigerant output from the condenser relative to the second portion of refrigerant, wherein second portion of the refrigerant is configured to adjust a magnitude of subcooling of the first portion of the refrigerant,
• an electronic expansion valve disposed along the second fluid line configured to exert a first pressure drop on the second portion of the refrigerant when the thermal expansion valve is open greater than a threshold position, wherein the threshold position is closed, wherein the first pressure drop is configured to decrease the temperature of the second portion of refrigerant;
• and
• a controller communicatively coupled to the electronic expansion valve and configured to control a valve position of the electronic expansion valve;
• a plurality of capillary expansion tubes fluidly coupled in parallel to an output of the first fluid line and configured to exert a second pressure drop on the refrigerant circulated through the cooling system;
• and
• an evaporator heat exchanger fluidly coupled to the plurality of expansion tubes, wherein:
• the evaporator heat exchanger comprises a plurality of evaporator paths;
• each of the plurality of evaporator paths is fluidly coupled to a corresponding one of the plurality of capillary expansion tubes;
• and
• each of the plurality of evaporator paths is configured to facilitate heat exchange between the refrigerant circulated through the evaporator heat exchanger and a surrounding fluid;
• and
• one or more sensors communicatively coupled to the controller and configured to measure a temperature and a pressure of the refrigerant output from the evaporator heat exchanger to a second location of the suction line and output the temperature and pressure measurements to the controller, wherein the second location is downstream of the first location;
• wherein the controller is configured to output a first instruction to the expansion valve to adjust the valve position of the expansion valve to a more open position when the measured temperature is greater than a threshold temperature.