Abstract: A multi-outdoor unit parallel type non-reversing defrosting system, which includes an indoor heat exchanger and three or more outdoor units arranged in parallel. The outdoor units each include a compressor, a four-way valve, an outdoor heat exchanger, a first solenoid valve, and a bypass branch. Two ends of the bypass branch are respectively in bypass connection with a pipeline between the four-way valve and the outdoor heat exchanger and a pipeline between the first solenoid valve and the indoor heat exchanger. The bypass branch is provided with a second solenoid valve configured to control connection and disconnection of the bypass branch. When it is monitored that any outdoor unit is abnormal in frosting, the outdoor units which are not frosted are correspondingly distributed and started as required on the basis of a current heating energy requirement A of the indoor heat exchanger.

Abstract: A three-pipe multi-split system. The three-pipe multi-split system includes an outdoor unit, a plurality of indoor units, and a plurality of hydraulic modules connected respectively by air pipes, liquid pipes, and condensate water pipes.

Abstract: A defrosting control method of a multi-functional multi-split system with double four-way valves. The multi-functional multi-split system includes an outdoor unit, at least one set of hydraulic modules, and at least one set of indoor modules. When the multi-split system is switched from a normal operation mode to a defrosting mode, a first four-way valve and a second four-way valve are powered down, and operation modes of each set of indoor modules and each set of hydraulic modules, the on/off state of fans of an indoor heat exchanger and a hydraulic heat exchanger, opening degrees of a first electromagnetic valve of the indoor heat exchanger and a second electromagnetic valve of the hydraulic heat exchanger, and the on/off state of the first electromagnetic valve and the second electromagnetic valve are correspondingly adjusted based on the previous operation modes of each set of indoor modules and each set of hydraulic modules.

Abstract: 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.

Abstract: A multi-connected heat recovery air conditioning system and a control method thereof. The multi-connected heat recovery air conditioning system includes an indoor unit, an outdoor unit and a hydraulic module, wherein the outdoor unit comprises a compressor, an outdoor heat exchanger, a first four-way valve and a second four-way valve. The multi-connected heat recovery air conditioning system further comprises an indoor unit temperature unit, a water temperature unit, a high-pressure sensor and a low-pressure sensor. The indoor unit temperature unit is arranged in the indoor unit for detecting and obtaining the outlet temperature value of the indoor unit, the water temperature unit is arranged at a heat exchange water tank for detecting and obtaining water temperature, and the high-pressure sensor and the low-pressure sensor are arranged at the output end and the air return end of the compressor respectively.

Abstract: An output inductance value controlling method, apparatus, and computer device for a multi-tap reactor. A single output port of the multi-tap reactor is correspondingly connected to a single relay, and each relay is connected to a general power supply of all air conditioner internal units. When in use, an air conditioning system acquires a motor speed and a phase current of each air conditioner internal unit separately, and then calculates a sum of motor powers of all the air conditioner internal units according to the motor speeds and the phase currents. The system matches a basic inductance value required by the air conditioner internal units according to the sum of motor powers, sets a current output inductance value of the multi-tap reactor according to the basic inductance value, and inputs the output inductance value into the corresponding air conditioner internal units.

Abstract: An automatic oil level retention system for a compressor and a method for controlling a same, including: a normal oil return mode and an auxiliary oil return mode. When a lubricating oil liquid level monitored by a liquid level detection unit in real time is above a required liquid level height, the system initiates only the normal oil return mode; and when the lubricating oil liquid level monitored by the liquid level detection unit in real time is below the required liquid level height, the system initiates the auxiliary oil return mode, and the auxiliary oil return mode is closed and the normal oil return mode is initiated after the lubricating oil liquid level monitored in real time is lifted above the required liquid level height.

Abstract: A communication circuit for indoor and outdoor units of an air conditioner and an air conditioner. The circuit includes an outdoor unit sending module, an outdoor unit receiving module, an indoor unit receiving module, an indoor unit sending module, a weak electricity grounding end and a voltage regulation rectifying circuit, wherein the voltage regulation rectifying circuit, the outdoor unit receiving module, the outdoor unit sending module, the indoor unit receiving module, the indoor unit sending module and the weak electricity grounding end are sequentially connected in series to form a loop; the voltage regulation rectifying circuit is configured to convert alternating current of a main control board of an indoor unit into direct current, and supply electricity to the loop.