A heat exchanger, a heat exchanger unit, and a refrigeration cycle apparatus improve a heat exchange performance, a discharge performance, and a frosting resistance, and each include: a flat tube; a fin formed in the shape of a plate having a plate surface extending in a longitudinal direction of the fin that is perpendicular to a width direction thereof, coincides with an up/down direction, and crosses the tube axis of the flat tube; and a first water conveyance member provided below the fin. The first water conveyance member has: a first upper surface facing a lower end portion of the fin; a first ridge located at one end portion of the first upper surface; and a second ridge located at the other end portion of the first upper surface.

A motor drive apparatus includes a power converter including an inverter having an upper arm and a lower arm, the inverter being configured to control an operation of an electric motor, and a drive controller configured to apply a dead time for preventing a short circuit between the upper arm and the lower arm, and to control the power converter. The drive controller is configured to control the power converter by switching a first mode in which a first correction value representing a time used to correct a voltage drop due to the dead time is employed to control the power converter, and a second mode in which a second correction value smaller than the first correction value is employed to control the power converter.

A heat pump system and a control method thereof. The heat pump system includes: a compressor; an indoor heat exchanger; an outdoor heat exchanger configured as an interlaced heat exchanger having at least two refrigerant flow paths; a plurality of throttling elements; and a first type four-way valve and a second type four-way valve; in a local defrosting mode, refrigerant flows sequentially from the exhaust port of the compressor through at least one of the at least two refrigerant flow paths of the outdoor heat exchanger, the throttling element, at least another of the at least two refrigerant flow paths of the outdoor heat exchanger and the suction port of the compressor.

A heat pump system includes a compressor; an indoor heat exchanger; an outdoor heat exchanger configured as an interlaced heat exchanger having at least two refrigerant flow paths; a plurality of throttling elements; and a first type four-way valve and a second type four-way valve, with ports thereof respectively connected to the inlet and the outlet of the compressor, the indoor heat exchanger, and one of the at least two refrigerant flow paths of the outdoor heat exchanger; in a local defrosting mode, refrigerant from the outlet of the compressor flows respectively through the indoor heat exchanger and at least one of the at least two refrigerant flow paths of the outdoor heat exchanger, and then sequentially through the throttling elements, at least the other of the at least two refrigerant flow paths of the outdoor heat exchanger, and the inlet of the compressor.

A heat pump system and a control method thereof. The heat pump system includes a compressor; a heat storage heat exchanger, the pipeline connection of which is configured to be disconnectable from the heat pump system; an indoor heat exchanger and an outdoor heat exchanger; a plurality of throttling elements; and a first type four-way valve and a second type four-way valve, the ports of which are respectively connected to the air inlet and the air outlet of the compressor; the unconnected ports of the first type four-way valve are respectively connected to the outdoor heat exchanger and the heat storage heat exchanger; and the unconnected ports of the second type four-way valve are respectively connected to the indoor heat exchanger and connected to the port connected to the air inlet through a capillary or on-off valve; in a combined defrosting mode, the refrigerant dissipates heat from the indoor heat exchanger and the outdoor heat exchanger respectively.

The invention discloses a multi-split system with partitioned control. An output end of a compressor is in communication with first interfaces of a first four-way valve, a second four-way valve, and a third four-way valve respectively, a third interface of the first four-way valve is in communication with one end of an outdoor heat exchanger, a second interface of the second four-way valve is in communication with one end of one indoor unit set therein, a third interface of the third four-way valve is in communication with one end of the other indoor unit set, and the other end of the outdoor heat exchanger and the other ends of the indoor unit sets are in communication with each other in a convergence manner; the remaining interfaces of the second four-way valve and the third four-way valve are all in communication with an air return end of the compressor.

A refrigeration apparatus includes a refrigerant circuit switchable between a first operation of performing a refrigeration cycle in which a first compressor is stopped and a second compressor is driven and a second operation of performing a refrigeration cycle in which the first and second compressors and are driven. The refrigeration apparatus further includes a reduction mechanism configured to reduce a refrigerant flowing into the first compressor while a first condition is satisfied during the first operation. The first condition indicates that an internal pressure of the first compressor is lower than an evaporation pressure of an evaporator.

A method for terminating defrosting of an evaporator (104) is disclosed. The evaporator (104) is part of a vapour compression system (100). The vapour compression system (100) further comprises a compressor unit (101), a heat rejecting heat exchanger (102), and an expansion device (103). The compressor unit (101), the heat rejecting heat exchanger (102), the expansion device (103) and the evaporator (104) are arranged in a refrigerant path, and an air flow is flowing across the evaporator (104). When ice is accumulated on the evaporator (104), the vapour compression system (100) operates in a defrosting mode. At least one temperature sensor (305) monitors a temperature T.sub.air, of air leaving the evaporator (104). A rate of change of T.sub.air is monitored and defrosting is terminated when the rate of change of the temperature, T.sub.air, approaches zero.

An air conditioner switches between a normal refrigeration cycle and a defrosting refrigeration cycle, and includes: a refrigerant circuit that connects a first heat exchanger, a second heat exchanger, a radiation panel, and an expansion valve that regulates a flow rate of a refrigerant flowing through the radiation panel; and a controller that causes the air conditioner to switch between the normal refrigeration cycle and the defrosting cycle. During the normal refrigeration cycle, the radiation panel performs cooling or heating. During the defrosting cycle, the first heat exchanger serves as a radiator and the second heat exchanger serves as an evaporator. During the defrosting cycle, the controller causes the expansion valve to be in a fully closed state.

Provided is an air conditioning apparatus. The air conditioning apparatus includes an outdoor unit through which a refrigerant is circulated, an indoor unit through which water is circulated, and a heat exchange device including a heat exchanger in which the refrigerant and the water are heat-exchanged with each other. The heat exchanger includes a high-pressure guide tube, a low-pressure guide tube, a liquid guide tube, a bypass tube configured to connect a bypass branch point of the high-pressure gas tube of the outdoor unit to a bypass combination point of the liquid guide tube to bypass a high-pressure refrigerant existing in the high-pressure tube to the liquid guide tube, and a bypass valve installed in the bypass tube. The outdoor unit includes a first valve device configured to guide a refrigerant compressed in the compressor to the outdoor heat exchanger and a second valve device configured to guide the refrigerant compressed in the compressor to the high-pressure guide tube of the heat exchange device.