Abstract: The invention discloses an electronic expansion valve. The electronic expansion valve includes: a valve body (10), a first chamber being formed in the valve body (10), a liquid inlet (11) and a liquid outlet (12) being oppositely provided at two ends of the valve body (10); a second chamber, provided in the first chamber, a coil (20) being provided in the second chamber; a third chamber, an inlet end of the third chamber being communicated with the liquid inlet (11), an outlet end of the third chamber being communicated with the liquid outlet (12), the inlet end of the third chamber and the outlet end of the third chamber being coaxially provided, and a valve core (31) being provided in the third chamber; and the first chamber being communicated with the liquid inlet (11) via the first liquid passage hole (33).

Abstract: An oil return method for multi-split air conditioner in heating comprises steps of: S1, adjusting operation frequency f0 of a compressor (11) to a first preset oil return frequency f1, and simultaneously, adjusting open degree S0 of each indoor throttling element (22) to a preset oil return open degree; S2, measuring operation parameters of the air conditioner; S3, judging whether the air conditioner operates abnormally, jumping to Step S4 if so, or jumping to Step S5 if not; S4, exiting from oil return process, adjusting the operation frequency f0 of the compressor (11) to a second preset oil return frequency f2, judging whether the air conditioner operates abnormally, existing from the oil return process if so, or jumping to Step S5 if not; S5, ending the oil return process when oil return time reaches the oil return time t2.

Abstract: The invention discloses an electronic expansion valve. The electronic expansion valve includes: a valve body (10), a first chamber being formed in the valve body (10), a liquid inlet (11) and a liquid outlet (12) being oppositely provided at two ends of the valve body (10); a second chamber, provided in the first chamber, a coil (20) being provided in the second chamber; a third chamber, an inlet end of the third chamber being communicated with the liquid inlet (11), an outlet end of the third chamber being communicated with the liquid outlet (12), the inlet end of the third chamber and the outlet end of the third chamber being coaxially provided, and a valve core (31) being provided in the third chamber; and the first chamber being communicated with the liquid inlet (11) via the first liquid passage hole (33).

Abstract: An oil return method for multi-split air conditioner in heating comprises steps of: S1, adjusting operation frequency f0 of a compressor (11) to a first preset oil return frequency f1, and simultaneously, adjusting open degree S0 of each indoor throttling element (22) to a preset oil return open degree; S2, measuring operation parameters of the air conditioner; S3, judging whether the air conditioner operates abnormally, jumping to Step S4 if so, or jumping to Step S5 if not; S4, exiting from oil return process, adjusting the operation frequency f0 of the compressor (11) to a second preset oil return frequency f2, judging whether the air conditioner operates abnormally, existing from the oil return process if so, or jumping to Step S5 if not; S5, ending the oil return process when oil return time reaches the oil return time t2.