For more efficient operation of an air cooled chiller, a refrigerant pump and bypass valve connected in parallel feed refrigerant from the condenser to a receiver. The pump is activated in response to pressure in the condenser; the bypass is used otherwise. Further efficiency is provided by controlling the condenser fan based on power consumption by the air cooled chiller and/or resetting a set point of the evaporator to meet load conditions. An expansion valve for the evaporator is controlled based on chilled water temperature, such as Delta T, or information from an air handling unit. Feedback of valve setting or position, air temperature, valve size, and/or importance of an air handling unit may be used to control the flow of chilled water. In addition to or an alternative to control of the chilled water flow, the refrigerant temperature may be controlled based on information from the air handling unit.

A heat pump device includes a compressor including a compression mechanism that compresses a refrigerant and a motor that drives the compression mechanism, an inverter that applies a voltage for driving the motor, a converter that applies a voltage to the inverter, an inverter control unit that generates a driving signal for driving the inverter, and a converter control unit that generates a driving signal for driving the converter. The inverter control unit includes a heating-operation-mode control unit that controls a driving-signal generating unit such that the driving-signal generating unit outputs, as inverter driving signals, PWM signals for heating the compressor without rotationally driving the motor by feeding a high-frequency current that the motor cannot follow in a heating operation mode.

The present invention is directed to an apparatus for minimizing power consumption in a cooling system. In one embodiment, the apparatus comprises one or more processors, one or more sensors associated with one or more regulated environments and one or more chillers that regulate temperature of the one or more regulated environments and a storage device, coupled to the one or more processors, storing instructions that when executed by the one or more processors performs a method. The method comprises gathering readings from the one or more sensors, determining a cost and power consumption associated with setting values for a plurality of control variables associated with the one or more chiller plants, selecting values for the control variables with a minimum cost as optimized control variable values and applying the optimized control variable values to the plurality of control variables to minimize power consumption of the cooling system.

A DC-powered system may include controls configured to switch between available DC power supplies and manage the refrigeration system in accordance with one or more methods. The one or more methods of the control system may include multiple tiers of power management, including, e.g., maximization of power usage when on a photovoltaic power supply to subcool a refrigerated load.

An apparatus for controlling a refrigerator, and a method for diagnosing a fault of the refrigerator are presented. More specifically, a power consumption of a refrigerator may be measured, and a fault of a plurality of loads included in the refrigerator may be diagnosed based on the measured power consumption. Accordingly, all of the plurality of loads included in the refrigerator may be diagnosed whether they have a fault or not. Further, among the plurality of loads included in the refrigerator, one or more loads having feedback uncontrollable may be diagnosed whether they have a fault of not.

A cryocooler includes a motion conversion mechanism that converts rotating motion output by a motor into linear reciprocating motion of a displacer and includes a first component and a second component slidably connected to each other, a measuring instrument that is connected to the motor to output time-series data indicating power consumption of the motor or a current flowing through the motor, and a processing unit that detects abrasion of a sliding surface between a first component and a second component of the motion conversion mechanism on the basis of section data including an intake start timing or an exhaust start timing in the time-series data.

A method for remotely diagnosing an abnormality in a climate control device includes the following steps: (a) receiving, at a diagnostic device remote from the climate control device, a signal representing one or more operating parameters of the climate control device, (b) generating, at the diagnostic device, an operating state metric at least partially from the signal representing the one or more operating parameters, (c) comparing, at the remote diagnostic device, the operating state metric to a reference metric, and (d) diagnosing, at the remote diagnostic device, the abnormality in response to a difference between the operating state metric and the reference metric.

A dehumidifying system and method for reducing humidity in ambient air is disclosed. The system includes a circulation unit, a refrigeration unit, a condensate receptacle for receiving condensate generated by the refrigeration unit, a controller to control both the circulation and refrigeration units, and wherein the controller receives input from one or more ambient sensors configured to sense ambient conditions, and a user interface configured to receive input from a user. The system implements variable speed control within the circulation and/or refrigeration unit to maximize efficiency or capacity under a current threshold, and enables the system to delay the need for defrost cycling during low temperature operation.

The degree of freedom when a refrigerant cycle system is constructed in a building or the like is increased. A refrigerant cycle system according to the present disclosure includes a refrigerant cycle, a first power feed unit, a second power feed unit, a first transmission line, and a second transmission line. The power feed unit feeds auxiliary power to a utilization unit of which a power source has been interrupted. The first transmission line connects a heat source unit and the first power feed unit to each other. The second transmission line connects the first power feed unit and the second power feed unit to each other. The second power feed unit is connected to the heat source unit via the first power feed unit.

The disclosed technology includes systems and methods for operating a fluid heating device comprising a heat pump and an electric heating element. The disclosed technology can include a system and method that can receive current data from a current sensor and temperature data from a temperature sensor, determine whether the current is greater than or equal to a threshold current and whether the temperature is greater than or equal to a threshold temperature, and output a control signal to heat the fluid using the heat pump only or the electric heating element only based on the current data and the temperature data.