A refrigeration system includes a compressor, a condenser, a heat transfer component, and a refrigerant loop arranged to allow a flow of a refrigerant fluid. The compressor, the condenser, and the heat transfer component are connected in the refrigerant loop. The system further includes a bypass path extending between an output side of the compressor in the refrigerant loop and an input side of the heat transfer component in the refrigerant loop. A bypass valve is connected in the bypass path. A control circuit is in communication with the bypass valve. The control circuit is configured to open the bypass valve to allow the refrigerant fluid to pass to the heat transfer component thereby increasing the refrigerant fluid provided to the heat transfer component and artificially increasing a load on the refrigeration system. Other examples refrigeration system and examples methods are also disclosed.

An information processing apparatus obtains a heat load equation for calculating a heat load corresponding to a time at which a predetermined time period has elapsed from a current point in time using learning data concerning a heat load influencing factor of an air-conditioning apparatus, estimates, in a case where a compressor continues performing a low load operation, in which operation is performed at a standard operating frequency or less, for a predetermined time period or more, whether the heat load will become higher than the current point in time after the predetermined time period has elapsed using the heat load equation obtained, outputs, when estimating that the heat load will not become higher, an oil return command signal commanding that an operating frequency be increased to the compressor, and does not output, when estimating that the heat load will become higher, the oil return command signal to the compressor.

A refrigerator management method according to one aspect of the present invention includes: obtaining log information including temperature information indicating an interior temperature of a refrigerator and opened and closed information indicating whether or not a door of the refrigerator has been opened and closed; calculating, based on the log information, a timewise change in the interior temperature for when the door is opened and closed in a predetermined period and for when the door is not opened and closed in the predetermined period; and outputting result information indicating a calculation result calculated in the calculating.

An HVAC system includes an unloading device, a centrifugal compressor, a gas foil bearing, a VFD and a controller. The controller is programmed to start the centrifugal compressor from a stopped condition by operating the unloading device to remove a load from the centrifugal compressor, accelerating the motor to a first speed above a liftoff speed of the gas foil bearing and below an operating speed of the centrifugal compressor, running the motor for a period of time, operating the unloading device to apply the load to the centrifugal compressor, and accelerating the motor to the operating speed.

Disclosed is a method for controlling a refrigerator including a motor driving a compressor. The method for controlling a refrigerator includes: identifying driving revolutions per minute (RPM) for driving of the motor; performing a control of temperature in the refrigerator based on the identified driving RPM; and storing operation information of the motor associated with the performing of the control of temperature, where the identifying of the driving RPM involves identifying stored operation information of the motor associated with a previous motor driving process.

An abnormality determination device for a transporting refrigeration apparatus includes a determination unit that determines an abnormality of the transporting refrigeration apparatus installed on a container. In pre-trip inspection that is conducted before the container is loaded on a transporting device, a test operation is performed for test operating modes. The pre-trip inspection is conducted multiple times. The abnormality determination device is configured to obtain at least part of time series test data related to a same one of the test operating modes in the pre-trip inspection. The determination unit is configured to determine whether the transporting refrigeration apparatus has an abnormality based on a change trend of the time series test data related to a same one of the test operating modes when the pre-trip inspection is conducted multiple times, and when there is no abnormality, estimate an abnormality occurrence time.

A controller unit for controlling the speed of a motor for driving an oil injected compressor, the controller unit including: a data connection; and a first module to receive data through the data connection. The controller unit includes a processing unit for determining a minimum working speed of the motor on the basis of the measured working pressure, the ambient temperature and a dew point temperature; and a comparator unit to compare the determined minimum working speed with the retrieved working speed of the motor. The processing unit includes a signal generating unit to send a signal to the motor for increasing the working speed of the motor to at least the determined minimum working speed, if the retrieved working speed is lower than the determined minimum working speed.

This air conditioning device for a vehicle comprises: an indoor condenser; an indoor evaporator; a first expansion valve; a second expansion valve; a refrigerant line; an expansion valve control detector; and a controller. The expansion valve control detector is constituted by: only one temperature sensor that detects the temperature of refrigerant in an inter-expansion valve line of the refrigerant line; and only one pressure sensor that detects the pressure of the refrigerant in the inter-expansion valve line. During a cooling operation, the controller issues, to the first expansion valve, an opening command corresponding to a state quantity of the refrigerant that has been detected by the expansion valve control detector, and during a heating operation, the controller issues, to the second expansion valve, an opening command corresponding to a state quantity of the refrigerant that has been detected by the expansion valve control detector.

A heat exchanger system that includes a heat exchanger that includes a plurality of circuits wherein the heat exchanger is configured to exchange heat between a refrigerant and a working fluid. The heat exchanger system also includes a valve configured to fluidly couple a circuit of the plurality of circuits to a flow path of the refrigerant. Further, the heat exchanger system includes a controller that is configured to receive feedback indicative of an operating parameter of the heat exchanger system and actuate the valve based on the operating parameter.

A power converting apparatus includes: a rectifying unit configured to rectify an input AC power, a buck converter that is configured to step down a voltage of the rectified power and that is configured to output DC power having the step down voltage, a first inverter that is connected to an output terminal of the buck converter and that is configured to convert the DC power into AC power to drive a first motor, a second inverter that is connected to the output terminal of the buck converter, that is disposed in parallel to the first inverter, and that is configured to convert the DC power into AC power to drive a second motor, and a converter controller configured to control an output voltage of the DC power of the buck converter.