A refrigerant leakage determination device includes a calculator and a determination unit. The calculator calculates a deviation degree of a refrigerant circuit from a normal state based on data related to operation of a refrigeration apparatus. The determination unit determines refrigerant leakage or estimates refrigerant leakage occurrence time based on a calculation result of the calculator. The calculator calculates first and second index values respectively from data related to operation of the refrigeration apparatus in a first period and a second period that differs in length from the first period and calculates the deviation degree of the refrigerant circuit from the normal state based on the first and second index values. The determination unit determines refrigerant leakage or estimates refrigerant leakage occurrence time based on the deviation degree of the refrigerant circuit from the normal state.

A refrigeration apparatus includes a compressor, a heat source-side heat exchanger, a receiver, a utilization-side heat exchange, a receiver degassing pipe interconnecting an upper portion of the receiver and a suction side of the compressor, and a receiver liquid level detection pipe connected to the receiver. The receiver liquid level detection pipe detects whether or not liquid level in the receiver has reached a predetermined position on a lower side of a position where the receiver degassing pipe is connected. The receiver liquid level detection pipe merges with the receiver degassing pipe via a capillary tube. The receiver degassing pipe has a refrigerant heater to heat refrigerant flowing through the receiver degassing pipe. Whether or not the liquid level in the receiver has reached the predetermined position is detected using a temperature of refrigerant flowing though the receiver degassing pipe.

A refrigeration apparatus includes a compressor, a heat source-side heat exchanger, a receiver, a utilization-side heat exchange, a receiver degassing pipe interconnecting an upper portion of the receiver and a suction side of the compressor, and a receiver liquid level detection pipe connected to the receiver. The receiver liquid level detection pipe detects whether or not liquid level in the receiver has reached a predetermined position on a lower side of a position where the receiver degassing pipe is connected. The receiver liquid level detection pipe merges with the receiver degassing pipe via a capillary tube. The receiver degassing pipe has a refrigerant heater to heat refrigerant flowing through the receiver degassing pipe. Whether or not the liquid level in the receiver has reached the predetermined position is detected using a temperature of refrigerant flowing though the receiver degassing pipe.

A refrigeration system includes a gas cooler or a condenser configured to reject first heat from a first fluid that is at a first pressure and that is in a supercritical state or subcritical state. The refrigeration system further includes an evaporator configured to absorb second heat into a second fluid that is at a second pressure that is lower than the first pressure and that is in a liquid state, a vapor state, or a two-phase mixture of liquid and vapor. The refrigeration system further includes a rotary pressure exchanger configured to receive the first fluid from the gas cooler or the condenser, to receive the second fluid from the evaporator, and to exchange pressure, via a rotor of the rotary pressure exchanger, between the first fluid and the second fluid.

Heat pump type heating apparatus capable of performing a continuous dual-stage operation without stopping a high stage side compressor even when a return temperature of a heating medium reaches a prescribed high temperature and, thereby, improving a sense of being insufficiently warmed due to stoppage of the high stage side compressor or a sense of being insufficiently warmed due to execution of frequent defrosting operations. The heat pump type heating apparatus includes an internal heat exchanger (a second internal heat exchanger) that performs heat exchange between a low-temperature refrigerant on a low-pressure side of a low stage side refrigeration circuit and a high-temperature refrigerant on a high-pressure side of a high stage side refrigerant circuit, a bypass pipe bypassing the internal heat exchanger, and flow path control means that controls a refrigerant flow to each of the internal heat exchanger and the bypass pipe.

There is disclosed a vehicle air-conditioning device in which a refrigerant subcool degree in a radiator is appropriately controlled, so that comfortable and efficient vehicle interior air conditioning is achievable. The vehicle air-conditioning device executes a heating mode in which a controller lets a refrigerant discharged from a compressor 2 radiate heat in a radiator 4, decompresses the refrigerant by which heat has been radiated by an outdoor expansion valve 6, and then lets the refrigerant absorb heat in an outdoor heat exchanger 7. In the heating mode, the vehicle air-conditioning device controls a refrigerant subcool degree SC of the radiator 4 by the outdoor expansion valve 6. On a basis of a radiator inlet air temperature THin that is a temperature of the air flowing into the radiator 4, the controller corrects a target subcool degree TGSC that is a target value of the refrigerant subcool degree SC in the radiator 4 in a lowering direction, as the radiator inlet air temperature THin rises.

A heat exchanger includes an inner tube extending along a central axis, an array of a plurality of heat transfer members mounted to the inner tube, and a plurality of outer tubes disposed radially outward of and in parallel relationship to the inner tube, the inner and outer tubes extending longitudinally to pass through the array of heat transfer members. The heat exchanger is particularly suited for use as an engine exhaust cooler in connection with a transport refrigeration unit, wherein the inner tube defines an internal flow passage through which engine exhaust gas passes, each outer tube defines an internal flow passage through which refrigerant passes, and the plurality of flow passages between adjacent heat transfer members defines an air flow passage. In an embodiment, the heat transfer members may be annular disks having an internal chamber filled with air or other heat transfer working fluid.

An intermediate unit includes a liquid-side pipe, a first valve, and a refrigerant pressure sensor. The liquid-side pipe is connected to a liquid connection pipe connecting a heat source unit and a utilization unit together. A controller of the intermediate unit adjusts the opening degree of the first valve based on a value measured by the refrigerant pressure sensor. The pressure of a refrigerant to be sent through the liquid connection pipe from the intermediate unit to the utilization unit is adjusted by the first valve.

A thermal management system includes a closed dynamic cooling circuit, and a closed first steady-state cooling circuit. Each circuit has its own compressor, heat rejection exchanger, and expansion device. A thermal energy storage (TES) system is configured to receive a dynamic load and thermally couple the dynamic cooling circuit and the first steady-state cooling circuit. The dynamic cooling circuit is configured to cool the TES to fully absorb thermal energy received by the TES when a dynamic thermal load is ON, and the steady-state cooling circuit is configured to cool the TES when the dynamic thermal load is OFF.

This gas-liquid separator is provided with: a tank part which stores and separates a refrigerant; and a pipe connection part forming outlet/inlet ports for the refrigerant from the tank part. The pipe connection part has: a first connection part having a first connection pipe which guides the refrigerant to an expansion valve; a second connection part having a second connection pipe through which the cooled refrigerant returns; a third connection part having a third connection pipe which guides the refrigerant to a compressor; a fourth connection part having a fourth connection pipe which guides the refrigerant into the tank part from an outdoor heat exchanger; and a first flow path switching valve which allows the inside of the tank part to communicate with the third connection pipe during heating operations, and allows the second connection pipe to communicate with the third connection pipe during cooling operations.