A refrigeration cycle apparatus includes: an outdoor unit; a branch unit connected to the outdoor unit via a first pipe and a second pipe; a first indoor unit connected to the branch unit via a third pipe and a fourth pipe; and a second indoor unit connected to the branch unit via a fifth pipe and a sixth pipe. A refrigerant circuit includes a compressor, a first heat exchanger, a second heat exchanger, a third heat exchanger, and a six-way valve. The six-way valve switches between a first state in which the first heat exchanger acts as a condenser and at least the second heat exchanger acts as an evaporator and a second state in which the first heat exchanger acts as an evaporator and at least the second heat exchanger acts as a condenser.

An air conditioning apparatus includes: an outdoor unit configured to circulated refrigerant; a first pipe and a second pipe that are connected to the outdoor unit; an indoor unit configured to circulate water; and a heat exchange device that connects the outdoor unit to the indoor unit. The heat exchange device includes a first heat exchanger and a second heat exchanger that are each configured to perform heat exchange between the refrigerant and the water, a plurality of connection pipes, a bypass pipe configured to guide the refrigerant passing through the first heat exchanger to the second heat exchanger, and a bypass valve installed at the bypass pipe.

A data center cooling system has an indoor portion wherein heat is absorbed from components in the data center, and an outdoor heat exchanger portion wherein outside air is used to cool a first heat transfer fluid (e.g., water) present in at least the outdoor heat exchanger portion of the cooling system during a first mode. When an appropriate time has been reached to switch from the first mode to a second mode, the outdoor heat exchanger portion of the data cooling system is switched to a second heat transfer fluid, which is a relatively low performance heat transfer fluid (compared to the first fluid). It has a second heat transfer fluid freezing point, lower than the first heat transfer fluid freezing point, and sufficiently low to operate without freezing when the outdoor air temperature drops below a first predetermined relationship with the first heat transfer fluid freezing point.

The present invention provides a heat pump system which comprises a compressor (110), a mode switch valve assembly (120), a mode switch flow path, and a first heat exchanger, a second heat exchanger and a heat recovery heat exchanger respectively connected between the mode switch valve assembly and the mode switch flow path, wherein the mode switch flow path is provided with a first flow path (160), a second flow path (170) and a third flow path (180) which converge at an intersection point, and at least the first flow path and the second flow path are respectively provided with a throttling section (161,171), and the first flow path, the second flow path and the third flow path are controllably switched on/off to realize different function modes. Therefore, a heat pump unit having a heat recovery function is provided, which has advantages of simple structure and high operational reliability, etc.

Proposed a gas heat-pump system including: a compressor compressing refrigerant and discharging the compressed refrigerant; an engine providing a drive force to the compressor; a radiator that cools coolant which is heated while passing through the engine; an indoor heat exchanger causing heat exchange to occur between indoor air and the refrigerant and thus cooling or heating an indoor space; an outdoor heat exchanger condensing the refrigerant; a four-way valve switching a flow direction of the refrigerant in such a manner that the refrigerant discharged from the compressor flows to the outdoor heat exchanger in a cooling operation mode and flows to the indoor heat exchanger in a heating operation mode; and a hot-water storage tank causing the heat exchange to occur between stored water and the refrigerant, and thus cooling the refrigerant in the cooling operation mode and heating the refrigerant in the heating operation mode.

At a refrigeration cycle device, an injection pipe and an economizer heat exchanger are provided at a main refrigerant circuit. In addition, the refrigeration cycle device includes a sub-refrigerant circuit having a sub-usage-side heat exchanger. At the refrigeration cycle device, the sub-usage-side heat exchanger functions as an evaporator of a sub-refrigerant and cools a main refrigerant that has been cooled at the economizer heat exchanger, or functions as a radiator of the sub-refrigerant and heats the main refrigerant that has been cooled at the economizer heat exchanger.

A heat pump system includes a compressor, a first heat exchanger, a second heat exchanger, a third heat exchanger, an intermediate heat exchanger, a first throttling element and a first valve member. The intermediate heat exchanger includes a first heat exchange portion and a second heat exchange portion that may carry out heat exchange. A first port of the first heat exchange portion communicates with an inlet of the compressor. A second port of the first heat exchange portion may communicate with at least one of an outlet of the second heat exchanger and a second port of the third heat exchanger. A first port of the second heat exchange portion may communicate with a first port of the third heat exchanger. The first heat exchanger and the second heat exchanger are indoor heat exchangers which are configured to be disposed in an air-conditioning cabinet.

A heat pump system includes a compressor, a usage side heat exchanger, a heat source side heat exchanger, an expansion mechanism, a main refrigerant flow control valve switchable between cooling and heating modes, a gas reheat heat exchanger, a fan, and a secondary refrigerant flow control device switchable between first, second, and third modes. Refrigerant flows from the compressor discharge line to the main refrigerant flow control device in the first mode. Refrigerant flows from discharge line to gas reheat heat exchanger and then main refrigerant flow control valve in the second mode. Refrigerant flows both from discharge line to gas reheat heat exchanger and then main refrigerant flow control valve, and from discharge line to main refrigerant flow control valve without flowing through the gas reheat heat exchanger in the third mode. Refrigerant flows to the usage side and hot gas reheat heat exchanger in the heating mode.

A heat pump system includes a compressor, a usage side heat exchanger, a heat source side heat exchanger, an expansion mechanism, a main refrigerant flow control device switchable between cooling and heating modes, a gas reheat heat exchanger, a fan, and a secondary refrigerant flow control device switchable between first, second, and third modes. Refrigerant flows from the compressor discharge line to the main refrigerant flow control device in the first mode. Refrigerant flows from discharge line to gas reheat heat exchanger and then main refrigerant flow control device in the second mode. Refrigerant flows both from discharge line to gas reheat heat exchanger and then main refrigerant flow control device, and from discharge line to main refrigerant flow control device without flowing through the gas reheat heat exchanger in the third mode. Refrigerant may flow to the usage side and hot gas reheat heat exchanger in the heating mode.

A dynamic receiver is included in parallel to an expander of a heating, ventilation, air conditioning, and refrigeration (HVACR) system. The dynamic receiver allows control of the refrigerant charge of the HVACR system to respond to different operating conditions. The dynamic receiver can be filled or emptied in response to the subcooling observed in the HVACR system compared to desired subcooling for various operating modes. The flow through an expander of the HVACR system can be controlled to account for the mass flow rate through an outlet valve of the dynamic receiver when the dynamic receiver is emptied, preventing or reducing instability or effects on system parameters such as the suction superheat.