The invention provides an
air conditioning system, a controlling method and air conditioner. The
air conditioning system comprises a compressor, a condenser and an
evaporator, further comprise an oiltank, wherein the
oil tank communicates with a gas suction port of the compressor through a balance
pipe, the
air conditioning system further comprises a primary
injection device, the primary
injection device comprises a first
injector, the first high-
pressure injection end of the first
injector communicates with the condenser, the first low-
pressure injection end communicates with the
evaporator,and the first outlet end of the first
injector communicates with the
oil tank. According to the air conditioning system, the controlling method and the air conditioner, a scheme that oil is directlyinjected to the gas suction port of the compressor is abolished, and the oil is prevented from being directly injected to the gas suction port of the compressor to be taken away by a gas flow, so thatthe condition that the compressor is caused to lack the oil is avoided, normal oil return when the compressor sucks is guaranteed, a secondary injection pipeline is removed, a primary injection pipeline is directly connected with the
oil tank, the combination of oil return injection and
oil cooling assistance is adopted, the times of oil soaking of the balance
pipe can be reduced, and the stressstrain of the long-segment pipeline can be reduced as well.