Expansion gear with needle valve and control fluid in a control device, for air-conditioner circuits using a fluid refrigerant based on a mixture of 1,1,1,2-tetrafluoropropene and trifluoroiodomethane

摘要

Expansion gear (12) for air-conditioner circuits with fluid refrigerant (FR), comprising a body (120) through which FR can pass under the control of a needle valve (134) and also a control device (200) containing control fluid (FC) and acting on the valve (134) according to the pressure of FC, in which FR is based on a mixture of 1,1,1,2-tetrafluoropropene (HFO-1234yf) and trifluoroiodomethane (CF3I) such that FC shows a saturation pressure higher than that of FR at a given temperature. An independent claim is also included for an air conditioner circuit (20) operating with FR and comprising a compressor (14), a condenser (11), expansion gear (12) as above and an evaporator (13), in which the expansion gear inlet (121) is connected to the condenser (11) and its outlet (123) is connected to the evaporator (13).