Abstract: An air conditioning system and a control method are provided. The air conditioning system includes: at least one heat exchanger (1, 2); and at least one control mechanism. Each control mechanism is connected to one of the at least one heat exchanger (1, 2) and is configured to control the corresponding heat exchanger to switch between a first working state and a second working state. The heat exchanger (1, 2) drains liquid when in the first working state and stores liquid when in the second working state.

Abstract: The present disclosure discloses a control method for a multi-split air conditioning system and a multi-split air-conditioning system, the multi-split air conditioning system, including a compressor and a plurality of indoor units respectively arranged on a plurality of parallel branches, the indoor unit including a fan and the control method including: in a cooling mode, when the multi-split air conditioning system needs oil return, the multi-split air conditioning system opening a branch where an indoor unit in an off state is located, determining whether the indoor unit has reached a dewing condition, opening the branch on which the indoor unit is located, and controlling the fan of the indoor unit according to a determination result.

Abstract: The present disclosure relates to a method of controlling operation state of multi-split air conditioner and system, and a heat pump multi-split. The control method includes: determining a target operation mode of each indoor unit according to an operation mode set by a user for the indoor unit; performing statistics on heat exchange demands of the indoor units corresponding to different target operation modes, and determining a dominant operation mode among the target operation modes according to the heat exchange demands; and using the dominant operation mode as the operation mode of an outdoor unit.

Abstract: A mode switcher includes at least one mode conversion branch. The mode conversion branch includes: a liquid pipe section, a high-pressure gas pipe section and a low-pressure gas pipe section. The mode switcher further includes a high-pressure electronic expansion valve and a low-pressure electronic expansion valve, the high-pressure electronic expansion valve and the low-pressure electronic expansion valve are respectively arranged in series in the high-pressure gas pipe section and the low-pressure gas pipe section, so as to gradually be opened and closed during air conditioning mode switching to reduce a differential pressure between before and after a mode conversion operation. A heat recovery multi-split air conditioning system and control method are further provided.

Abstract: A variable refrigerant volume system includes: a compressor; a four-way valve; an indoor unit; a liquid tube, the first end thereof being connected to the indoor unit, the second end thereof being connected to the third valve port of the four-way valve, and a condenser being provided on the liquid tube; a low pressure air pipe, the first end thereof being connected to the indoor unit, and the second end thereof being connected to the fourth valve port of the four-way valve; a refrigerant adjustment tank, the first port thereof being connected to the liquid tube, the second port thereof being connected to the low pressure air pipe, and the third port thereof optionally communicating with the liquid tube or the low pressure air pipe.

Abstract: A variable refrigerant volume system and control method thereof. The variable refrigerant volume system comprises: a compressor (1); a four-way valve (19); an indoor unit; a liquid tube (22), the first end thereof being connected to the indoor unit, the second end thereof being connected to the third valve port of the four-way valve (19), and a condenser (18) being provided on the liquid tube (22); a low pressure air pipe (23), the first end thereof being connected to the indoor unit, and the second end thereof being connected to the fourth valve port of the four-way valve (19); a refrigerant adjustment tank (6), the first port thereof being connected to the liquid tube (22), the second port thereof being connected to the low pressure air pipe (23), and the third port thereof optionally communicating with the liquid tube (22) or the low pressure air pipe (23).

Abstract: A method of producing a pre-bent wind blade, includes: obtaining a pre-bent curve of a straight wind blade; and producing a bent wind blade according to the pre-bent curve, in such a manner that under a rating wind speed, the wind blade extends to be straight, so as to increase energy yield annually.