| 摘要 |
Provided is an air conditioning system for vehicles wherein a flow rate of refrigerant used for estimating a compressor torque can be accurately estimated by accurately detecting a difference between pressures at upstream and downstream sides of an orifice, which has a high correlation with the flow rate of refrigerant, and ultimately, the compressor torque can be accurately estimated, and this estimation can be performed while space saving and cost down can be achieved. The air conditioning system for vehicles having a refrigeration cycle provided with a refrigerant compressor, a condenser, a pressure reduction/expansion mechanism and an evaporator is characterized in that an orifice for throttling a refrigerant flow is disposed in a refrigerant path between the condenser and the pressure reduction/expansion mechanism, a pressure difference detection means capable of detecting a difference between pressures at upstream and downstream positions of the orifice is provided, and provided are a refrigerant flow rate estimation means for estimating a refrigerant flow rate with reference to the detected pressure difference and a compressor torque estimation means for estimating a compressor torque with reference to the estimated refrigerant flow rate.
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