A multi-split air-conditioner and an outdoor unit system thereof are provided. The outdoor unit system includes: a compressor (1) having a gas outlet (a) and a gas inlet (b); an outdoor heat exchanger (2) having an inlet (c) and an outlet (d); a switching assembly (3) having first to sixth ports, wherein the first port (e) is connected with the gas outlet (a) of the compressor (1), the second port (f) is connected with the gas inlet (b) of the compressor (1), the third port (g) is connected with the inlet (c) of the outdoor heat exchanger (2), the fourth port (h) is connected with the outlet (d) of the outdoor heat exchanger (2), the fifth port (i) is connected with an inlet pipe (4) and the sixth port (j) is connected with an outlet pipe (5).

A heat pump system, a defrosting method for the heat pump system, and a controller. The heat pump system includes a heat exchanger assembly for exchanging heat with a fluid medium, the heat exchanger assembly comprised a first heat exchanger and a second heat exchanger arranged in parallel, the second heat exchanger being arranged upstream of the first heat exchanger in the flow direction of the fluid medium, and when the heat pump system is operating in a heating mode and the temperature and/or ambient humidity to which the heat exchanger assembly is currently exposed reach a pre-set value, the second heat exchanger and the first heat exchanger function as a condenser and an evaporator, respectively.

A refrigeration cycle apparatus includes a heat source side unit, a relay unit, and a plurality of load side units, the heat source side unit and the relay unit are connected by using a low-pressure pipe and a high-pressure pipe, and the relay unit and each of the plurality of load side units are connected by using a corresponding liquid branch pipe and a corresponding gas branch pipe. The heat source side unit includes a compressor configured to compress refrigerant, at least one flow switching valve configured to change a passage of refrigerant based on an operation mode, and at least one heat source side heat exchanger, and the relay unit includes six-way valves or pairs of four-way valves.

A dual function water heater and air-conditioning unit including air-conditioner and water heater subassemblies. In the operational cycle illustrated, the unit heats the water in a geyser and operates an air-conditioner in cooling mode. The geyser heat exchanger acts as a condenser in which the refrigerant transitions from a vapor phase to a liquid phase. The liquid refrigerant is conveyed to an interior unit expansion valve where the liquid refrigerant is flash evaporated and conveyed to the interior unit heat exchanger operating as an evaporator, in which adiabatic cooling of the refrigerant causes extraction of heat from air flowing over the interior unit heat exchanger tubes. The extracted heat is transferred to the refrigerant, causing evaporation of the liquid refrigerant to a gaseous refrigerant, which is directed, from the internal unit heat exchanger to the compressor, for repetition of the cycle.

A heat recovery air-conditioning hot water system and a refrigerant flow control method therefor. The heat recovery air-conditioning hot water system includes a compressor, a condenser, heat exchangers, an indoor unit, a first throttling device, a second throttling device, a first reversing valve, and a second throttling device, wherein the first reversing valve is used to control the refrigerant switching of the indoor heat exchanger, so as to realize the switching of cooling and heating modes; the second reversing valve is used to control the refrigerant switching of the outdoor heat exchanger, so as to realize the operation switching of cooling and heating modes of the outdoor heat exchanger; and an exhaust pipe of the compressor is respectively connected to the first reversing valve, the second reversing valve, and the water-side heat exchanger by means of a water-side high-pressure air pipe.

An air conditioning, heat pump and water heating system includes a compressor, a switching valve, an outdoor heat exchanger, a refrigerant storage tank, an indoor heat exchanger and a water heater. The air conditioning, heat pump and water heating system is configured to selectively operate between an air conditioning mode, a heat pump mode, a first water heating mode and a second water heating mode. In the first water heating mode, heat absorbed from an indoor space is utilized to heat up water circulating in the water heater so that when the air conditioning, heat pump and water heating system is operated in the first water heating mode, no heat is discharged to ambient environment. In the second water heating mode, heat absorbed from an ambient environment is utilized to heat up water circulating in the water heater.

A heat pump system, a controlling method thereof, and a heat pump unit using the heat pump system. The heat pump system includes a compressor, a first heat exchanger, a second heat exchanger, a heat-recovery-type heat exchanger, a multi-way valve, a throttling element, and a mode-switching flow path, which has both air conditioning and water heating functions. By switching the multi-way valve and powering on/off electromagnetic valves in the heat pump system, the controlling method controls the heat pump system to implement multiple functional modes. Furthermore, the heat pump unit using the heat pump system provides multiple functions simply by laying a small amount of parts and elements and pipelines outdoors, thereby greatly reducing the engineering cost and cost of parts, and ensuring a much higher water heating efficiency.

A refrigeration cycle apparatus includes a heat exchanger, and a flow switching circuit configured to switch the heat exchanger to act as any one of an evaporator and a condenser, the flow switching circuit is configured to allow refrigerant to flow into the heat exchanger in the same direction both in a case where the heat exchanger acts as an evaporator and in a case where the heat exchanger acts as a condenser, the heat exchanger includes a path switching circuit including a plurality of paths, and the path switching circuit is configured to switch an order of the plurality of paths through which refrigerant flows between an order of the plurality of paths in the case where the heat exchanger acts as an evaporator and another order of the plurality of paths in the case where the heat exchanger acts as a condenser.

An air conditioning apparatus includes a refrigerant tank, a cryogenic liquid pump, a condensing evaporator, a compressor, a user system, a throttle valve, a first reversing valve, and a second reversing valve. It operates in two modes. In the first mode, the refrigerant in the refrigerant tank flows sequentially from the refrigerant tank, the cryogenic liquid pump, the condensing evaporator, the first reversing valve, the compressor, the second reversing valve, the user system, the first reversing valve, the second reversing valve, the condensing evaporator, the throttle valve, and back to the refrigerant tank. In the second mode, refrigerant in the refrigerant tank flows sequentially from the refrigerant tank, the cryogenic liquid pump, the condensing evaporator, the first reversing valve, the second reversing valve, the user system, the first reversing valve, the compressor, the second reversing valve, the condensing evaporator, the throttle valve, and back to the refrigerant tank.

Provided is a refrigeration cycle apparatus configured to perform a heating operation and a simultaneous heating and hot-water supply operation. The refrigeration cycle apparatus is configured to execute an operation mode circulating refrigerant through, in order, a discharge outlet of a compressor, a first heat exchanger, an expansion device, a second heat exchanger provided to a water tank, and a suction inlet of the compressor, and causing the refrigerant flowing through the second heat exchanger to evaporate by heat generated by a heat source provided to the water tank.