A refrigerant circuit has a liquid passage that allows a receiver to communicate with a utilization heat exchanger, and a first expansion valve provided in the liquid passage. The controller opens the first expansion valve when the compression element is in the stopped state and a pressure in the receiver exceeds a predetermined first pressure.

Disclosed are a refrigerator diagnostic method and a refrigerator using an artificial intelligence algorithm (AI) and/or machine learning algorithm in a 5G environment connected for the Internet of things. The refrigerator diagnostic method may include determining an installation state of a refrigerator based on a power value of a compressor provided in the refrigerator and the number of revolutions of a cooling fan provided in the refrigerator, when an operating time after initial installation of the refrigerator is less than or equal to a particular value, and determining a malfunction and a cleaning state of the refrigerator based on the power value of the compressor and the number of revolutions of the cooling fan, when the operating time after initial installation of the refrigerator exceeds the particular value.

There is disclosed a refrigeration system comprising a refrigeration circuit that includes a compressor, a condenser, an expansion valve and an evaporator. A condenser fan of the refrigeration system is configured to operate, under the control of a controller, at a condenser fan speed that is set based on a current refrigeration demand on the system.

There is disclosed a refrigeration system comprising a refrigeration circuit that includes a compressor, a condenser, an expansion valve and an evaporator. A condenser fan of the refrigeration system is configured to operate, under the control of a controller, at a condenser fan speed that is set based on a current refrigeration demand on the system.

Systems and methods for a vapor compression system including primary actuators, secondary actuators, primary sensors that provide a primary set of system outputs, and secondary sensors that provide a secondary set of system outputs. A primary controller receives the primary set of system outputs, and produces a primary set of control inputs for the primary actuators, to regulate one or more zone temperatures to set-points and to regulate one or more critical process variables to set-points. A secondary controller receives the secondary set of system outputs, and produces a secondary set of control inputs, to minimize an overall system power consumption. The secondary inputs may include set-points to the primary controller. The primary outputs may include estimates of critical process variables that are used as inputs to the secondary controller.

A cooling system is provided and includes pump, condenser fan, and control modules. The pump module controls a pump to pump a cooling fluid through a cooling circuit. The condenser fan module controls a condenser fan to transfer air across a condenser of the cooling circuit. The control module, while operating in a pumped refrigerant economizer mode or a mixed mode, determines a requested CFC percentage. The pump module activates the pump if the requested CFC percentage is greater than or equal to a predetermined CFC percentage. The condenser fan module: if the requested CFC percentage is greater than or equal to the predetermined CFC percentage, activates the condenser fan or operates the condenser fan at least at a minimum speed; and based on the requested CFC percentage, adjusts a speed of the condenser fan between the minimum speed and a maximum permitted speed to provide the requested CFC percentage.

A system and method are provided including a system controller for a refrigeration or HVAC system having a compressor rack with a compressor and a condensing unit with a condenser fan. The system controller monitors and controls operation of the refrigeration or HVAC system. A rack controller monitors and controls operation of the compressor rack and determines compressor rack power consumption data. A condensing unit controller monitors and controls operation of the condensing unit and determines condensing unit power consumption data. The system controller receives the compressor rack power consumption data and the condensing unit power consumption data, determines a total power consumption of the refrigeration or HVAC system, determines a predicted power consumption or a benchmark power consumption for the refrigeration system, compares the total power consumption with the predicted power consumption or the benchmark power consumption, and generates an alert based on the comparison.

A system and method are provided including a system controller for a refrigeration or HVAC system having a compressor rack with a compressor and a condensing unit with a condenser fan. The system controller monitors and controls operation of the refrigeration or HVAC system. A rack controller monitors and controls operation of the compressor rack and determines compressor rack power consumption data. A condensing unit controller monitors and controls operation of the condensing unit and determines condensing unit power consumption data. The system controller receives the compressor rack power consumption data and the condensing unit power consumption data, determines a total power consumption of the refrigeration or HVAC system, determines a predicted power consumption or a benchmark power consumption for the refrigeration system, compares the total power consumption with the predicted power consumption or the benchmark power consumption, and generates an alert based on the comparison.

A monitoring system is disclosed for a heating, ventilation, or air conditioning (HVAC) system of a residential or commercial building. The monitoring system includes an evaporator unit device including a first current sensor that measures current supplied to a circulator blower. The measured current from the first current sensor is used to diagnose a problem with the circulator blower. The monitoring system includes a first temperature sensor that measures refrigerant temperature between a condenser and an expansion valve. The monitoring system includes a second temperature sensor that measures refrigerant temperature between an evaporator and a compressor. The monitoring system includes a condenser unit device that communicates with the evaporator unit device. The condenser unit device includes a second current sensor that measures current supplied to the compressor. The evaporator unit device transmits sensor data to a remote monitoring service over a data network.

An internal temperature adjusting device includes a heat pump, an internal heat exchanger, and an external heat exchanger. The internal heat exchanger is configured to function as one of an evaporator or a condenser of the heat pump, and exchange heat between a heat medium and air inside the container. The external heat exchanger is configured to function as the other one of the evaporator or the condenser, and exchange heat between the heat medium and air outside the container. The external heat exchanger includes a plurality of heat exchanging members separated from each other. According to the internal temperature adjusting device, drainage of the external heat exchanger as a whole can be secured.