Patent ID: 11920840
Assignee: HEATCRAFT REFRIGERATION PRODUCTS LLC
Field: Thermal processes and apparatus (Mechanical engineering)
Classification: CPC F  Y | IPC F

Claim 0:
1. A heating, ventilation, and air conditioning (HVAC) system, comprising:
a refrigerant conduit subsystem;
a condensing unit configured to discharge heat from a refrigerant received from the refrigerant conduit subsystem;
a unit cooler comprising a first evaporator coil, a second evaporator coil, and a blower;
a first sensor disposed at a discharge side of the first evaporator coil, the first sensor configured to measure a temperature of the refrigerant discharged from the first evaporator coil;
a second sensor disposed at a discharge side of the second evaporator coil, the second sensor configured to measure a temperature of the refrigerant discharged from the second evaporator coil;
a pressure regulator disposed at a suction side of the first evaporator coil, wherein the pressure regulator is configured to control the suction pressure of the first evaporator coil such that the refrigerant in the first evaporator coil operates at a cooler temperature relative to the refrigerant in the second evaporator coil;
a first valve corresponding to the first evaporator coil and configured to provide a flow of the refrigerant into the first evaporator coil, wherein the first valve is disposed upstream of the unit cooler;
a second valve corresponding to the second evaporator coil and configured to provide the flow of the refrigerant into the second evaporator coil, wherein the second valve is disposed upstream of the unit cooler; and
a controller operable to:
receive the temperature of the refrigerant discharged from the first evaporator coil;
initiate a first defrost cycle for the first evaporator coil in response to the received temperature of the refrigerant discharged from the first evaporator coil, wherein initiating the first defrost cycle includes-by transmitting instructions to close the first valve to prevent the flow of refrigerant into the first evaporator coil;
transmit instructions to open the first valve when the first defrost cycle for the first evaporator coil has terminated;
receive the temperature of the refrigerant discharged from the second evaporator coil;
initiate a second defrost cycle for the second evaporator coil in response to the received temperature of the refrigerant discharged from the first evaporator coil, wherein initiating the second defrost cycle includes transmitting instructions to close the second valve to prevent the flow of refrigerant into the second evaporator coil;
transmit instructions to open the second valve when the second defrost cycle for the second evaporator coil has terminated; and
actuate the blower to direct air to flow over both the first evaporator coil and the second evaporator coil during the first defrost cycle and the second defrost cycle.