A refrigeration apparatus includes: a refrigerant circuit through which refrigerant circulates; a controller to execute a plurality of refrigerant shortage sensing functions of sensing a shortage of an amount of the refrigerant; and an input device through which an operation mode to be set is input into the controller. The operation mode includes: a first mode in which energy-saving performance is emphasized; and a second mode in which the refrigeration apparatus is permitted to operate in a range in which reliability is ensured. In accordance with the operation mode set through the input device, the controller determines which one of sensing results obtained by the refrigerant shortage sensing functions is enabled and which one of sensing results obtained by the refrigerant shortage sensing functions is disabled. When a sensing result determined to be enabled shows a refrigerant shortage, the controller gives a notification about the refrigerant shortage.

A modulating refrigeration system includes an evaporation unit and a condensing unit. The evaporation unit generates a first output airflow comprising a lower temperature, a lower relative humidity, or both than a first supply airflow and directs the first output airflow into a building. The condensing unit generates a second output airflow at a higher temperature than a second supply airflow and discharges the second output airflow to an unconditioned space. The evaporation unit comprises a first valve operable to direct a portion of refrigerant to a secondary evaporator and primary evaporator or to direct the entire flow of refrigerant to the primary evaporator and bypassing the secondary evaporator.

A heating, ventilation, and air-conditioning (“HVAC”) system for use with a refrigerant. The HVAC system includes a compressor, a condenser, an evaporator expansion device, and an evaporator. The HVAC system also includes a thermal energy storage device (“TESD”) including thermal energy storage media in line between the condenser and evaporator. A control system is programmed to operate the compressor and the evaporator expansion device to control the refrigerant flow through the HVAC system. The control system is also programmed to control the refrigerant flow through the TESD to charge the TESD with thermal energy. The control system is also programmed to control the refrigerant flow through the evaporator expansion device and evaporator and discharge the thermal energy from the charged TESD to improve the performance of the HVAC system.

Methods and systems for controlling working fluid flow in a heating, ventilation, air conditioning and refrigeration (HVACR) unit for an HVACR system are disclosed. The unit includes a compressor having a motor and a drive. The unit also includes a condenser fluidly connected to the compressor. A subcooler is located downstream of the condenser. The unit further includes an evaporator fluidly connected to the condenser. Also the unit includes a controller. The unit also includes a bypass assembly connected to the condenser. The bypass assembly includes a bypass flow control device and a bypass fluid line controlled by the bypass flow control device. When a heat recovery demand is detected by the controller, the controller is configured to open the bypass flow control device to allow a first portion of working fluid to bypass the condenser or the subcooler.

A refrigeration system includes a compressor for compressing a gaseous refrigerant, such that the temperature and pressure thereof increases; a four-way valve controlling whether the refrigeration system is in a heating mode or a cooling mode; a condenser, in which the gaseous refrigerant from the compressor exchanges heat with a high temperature heat carrier, said heat exchange resulting in the refrigerant condensing; an expansion valve reducing the pressure of liquid refrigerant from the condenser, hence reducing the boiling point of the refrigerant; an evaporator, in which the low boiling point refrigerant exchanges heat with a low temperature heat carrier, such that the refrigerant vaporizes; and a suction gas heat exchanger exchanging heat between high temperature liquid refrigerant from the condenser and low temperature gaseous refrigerant from the evaporator. A balance valve is arranged for controlling the amount of heat exchange between the high temperature liquid refrigerant and the low temperature gaseous refrigerant in the suction gas heat exchanger by directing a flow of high temperature liquid refrigerant directly from the condenser to the expansion valve. Disclosed is also a method for controlling such a system.

A refrigerant amount inference apparatus infers a refrigerant amount in an air conditioner in which a compressor, a heat source side heat exchanger, a supercooling heat exchanger, a pressure reducing valve, and a use side heat exchanger are connected to piping. The supercooling heat exchanger exchanges heat between refrigerant that passes through a valve provided in a bypass circuit and refrigerant in a mainstream circuit. The refrigerant amount inference apparatus includes an acquiring unit that acquires a state of refrigerant in first piping provided between the pressure reducing valve and the supercooling heat exchanger and an operation amount related to the state of the refrigerant in the first piping, and a training unit that performs training by associating the state of the refrigerant in the first piping and the operation amount related to the state of the refrigerant in the first piping with a refrigerant amount.

An outdoor unit is connected to a refrigerator and has two compressors that are connected in series, and a control method thereof. The outdoor unit according to an embodiment of the present invention includes a low pressure side compressor for compressing a refrigerant; a high pressure side compressor for compressing the refrigerant compressed by the low pressure side compressor; an outdoor heat exchanger for condensing the refrigerant compressed by the high pressure side compressor; a heat recovery unit for cooling the refrigerant condensed in the outdoor heat exchanger by exchanging heat with the refrigerant evaporated in the air conditioner; and a supercooler for expanding a part of the refrigerant cooled in the heat recovery unit to cool another part of the refrigerant cooled in the heat recovery unit, so that the discharge temperature of the low pressure side compressor and/or the high pressure side compressor can be reduced.

There is disclosed a refrigeration apparatus comprising a refrigerant circuit, the refrigerant circuit comprising a compressor comprising a compressor fan and a motor to drive the compressor fan; a condensing device disposed downstream of the compressor, the condensing device comprising a condenser and a sub-cooler; an expansion valve disposed downstream of the condensing device; an evaporator disposed between the expansion valve and the compressor; and a main refrigerant line fluidically connecting, in a loop in series: the compressor, condensing device, expansion valve and evaporator. A motor cooling line comprising a motor cooling valve fluidically connects the sub-cooler to the motor to tap refrigerant from the main refrigerant line to cool the motor and is further connected to the main refrigerant line at a return point which is upstream of the compressor fan to return refrigerant to the main refrigerant line at the compressor fan. A bypass line fluidically connects an outlet of the condenser to the expansion valve to bypass the sub-cooler, wherein the bypass line comprises a bypass valve to selectively permit refrigerant in the main refrigerant line to bypass the sub-cooler.

There is provided a vehicle air conditioning apparatus capable of removing frost formed on an outdoor heat exchanger at the same time as cooling of a battery. The vehicle air conditioning apparatus performs the operation in a first battery cooling mode, a second battery cooling mode, or a solo battery cooling mode, when it is determined that the battery needs to be cooled and also determined that the frost formed on the outdoor heat exchanger needs to be removed. By this means, it is possible to cool the battery and melt the frost formed on the outdoor heat exchanger at the same time by the battery cooling operation, and therefore it is possible to reduce the power consumption compared to the case where the battery cooling operation and the defrosting operation are performed individually.

A system for cooling a plurality of processors in a data center is disclosed. The cooling system includes a refrigeration system having a compressor for compressing a carbon dioxide (CO2) working fluid, an air cooled heat exchanger downstream from the compressor and located out-of-doors for cooling the working fluid, an expansion device downstream from the heat exchanger, a cooling device located within the data center in which the working fluid is expanded to cool the processors by circulating the cooled air around the processors, and a return line for the return of the working fluid from the cooling device to the compressor.