A non-stop defrosting multi-connected hot water system and a control method. Heat is recovered by utilizing the characteristic of a phase-change heat storage module that can store heat, and then the heat is released during defrosting. In a defrosting process, modes of a hydraulic module and an indoor unit are not changed, and a four-way valve is not reversed, so as to avoid the influence of the defrosting process on an indoor ambient temperature and a water temperature of the hydraulic module, and avoid the condition where a liquid refrigerant generated in the defrosting process does not evaporate and directly flows back into a compressor which causes liquid return of the compressor, thus improving the reliability of the overall operation of the system.

An air-conditioning apparatus includes an outdoor unit and a relay unit. The outdoor unit includes a compressor compressing and discharging refrigerant and a heat-source-side heat exchanger performing heat exchange between the refrigerant and outside air. The relay unit and the outdoor unit form a refrigerant circuit. The outdoor unit includes first and flow switching devices each switching an associated flow passage for the refrigerant between a plurality of flow passages, according to an operation mode. An outflow pipe and an inflow pipe through which refrigerant flows from the outdoor unit to the relay unit and from the relay unit into the outdoor unit, respectively, are between the outdoor unit and the relay unit. The first flow switching device is connected to the compressor, the second flow switching device, and the outflow pipe. The second flow switching device is connected to the first flow switching device and the inflow pipe.

A variable refrigerant flow (VRF) system, which includes: a first outdoor unit, the first outdoor unit at least including three external interfaces, namely, a gas-side stop valve, a liquid-side stop valve, and a multi-functional pipe stop valve; a first indoor unit, two ends of a refrigerant pipeline of the first indoor unit being respectively in communication with the gas-side stop valve and the liquid-side stop valve; and a replaceable module, one end of a refrigerant pipeline of the replaceable module being in communication with the multi-functional pipe stop valve, and the other end being in communication with the liquid-side stop valve.

An air-conditioner includes: a return-air inlet and a supply-air outlet each communicating with a predetermined space; a first main air channel configured to allow air to flow therein towards the supply-air outlet; a first heat exchanger disposed in the first main air channel and that causes heat-exchange between refrigerant flowing therein and air passing therethrough; an exhaust-air outlet communicating with an outside of the predetermined space; a second main air channel configured to allow air to flow therein towards the exhaust-air outlet; a second heat exchanger disposed in the second main air channel and that causes heat-exchange between refrigerant flowing therein and air passing therethrough; and an exhaust ventilation channel configured to allow air to flow therein from the return-air inlet towards the exhaust-air outlet.

Provided are a three-tube heat recovery multi-split air conditioning system and control method for the same, the system including: an outdoor unit; an indoor unit; a refrigerant distribution device, including a heat exchange assemble, a cooling-heating switching valve, and a low temperature cooling and anti-freezing module; and a controller, configured to acquire an evaporation temperature of the cooling indoor unit and an outdoor ambient temperature when the three-tube heat recovery multi-split air conditioning system operates in a cooling mode or a mixed operation mode, determine whether the evaporation temperature of the cooling indoor unit requires to be adjusted according to the evaporation temperature of the cooling indoor unit and the ambient temperature, and control the low temperature cooling and anti-freezing module to adjust the evaporation temperature of the cooling indoor unit if the evaporation temperature of the indoor unit requires to be adjusted.

A refrigeration cycle apparatus includes a refrigeration circuit in which non-azeotropic refrigerant mixture circulates. The refrigeration circuit includes a compressor, an outdoor heat exchanger, an indoor heat exchanger, an expansion valve, and a four-way valve. The four-way valve is configured to assume a first state and a second state. The outdoor heat exchanger includes a plurality of refrigerant flow paths and a linear flow path switching valve configured to switch connections of the plurality of refrigerant flow paths between a series state in which the non-azeotropic refrigerant mixture flows through the plurality of refrigerant flow paths in series and a parallel state in which the non-azeotropic refrigerant mixture flows through the plurality of refrigerant flow paths in parallel. A controller switches the linear flow path switching valve between the series state and the parallel state when a multi-way valve is in the second state.

A system comprising a compressor, a first valve coupled to the compressor and coupled to a first coil, a first expansion valve coupled to the first coil, a second coil, and a second expansion valve. The second expansion valve coupled to a third coil, a second valve coupled to the compressor and the third coil. A controller operable to operate the first valve, the first expansion valve, the second expansion valve, and the second valve. The second coil is coupled to the compressor and the refrigerant flows from the second coil to the compressor.

An energy efficient heat pump for a heating, ventilation, and air conditioning (HVAC) system includes a vapor compression circuit, a first heat exchanger of the vapor compression circuit configured to place a working fluid in a first heat exchange relationship with a first air flow directed across the first heat exchanger, a second heat exchanger of the vapor compression circuit configured to place the working fluid in a second heat exchange relationship with a second air flow directed across the second heat exchanger, and a valve system of the vapor compression circuit. The valve system is adjustable between a first configuration and a second configuration, the heat pump is configured to operate in a cooling mode with the valve system in the first configuration, the heat pump is configured to operate in a heating mode with the valve system in the second configuration, and the valve system is configured to direct the working fluid into the first heat exchanger to place the working fluid in a counterflow heat transfer arrangement with the first air flow directed across the first heat exchanger in the first configuration and in the second configuration.

A refrigeration cycle apparatus includes: a compressor; an indoor heat exchanger; an outdoor heat exchanger including first and second outdoor heat exchangers; a bypass flow passage causing a discharge side of the compressor to communicate with the first or second outdoor heat exchanger; a flow control valve at the bypass flow passage; and a controller performing a heating operation in which the first and second outdoor heat exchangers operate as an evaporator and the indoor heat exchanger operates as a condenser and a simultaneous heating and defrosting operation in which part of refrigerant the compressor discharges is supplied to one of the first and second outdoor heat exchangers through the bypass flow passage, the other of the outdoor heat exchangers operates as an evaporator, the indoor heat exchanger operates as a condenser, and an upper limit frequency of the compressor changes to a value higher than in the heating operation.

A heat-source-side heat exchanger is divided so that a heat-source-side heat exchanger that functions as an evaporator also functions as an intermediate cooler. Since, when an air conditioner includes a bypass pipe, a heat-source-side heat exchanger that functions as an evaporator and as an intermediate cooler also further functions as a radiator, operation efficiency is increased.