Method For Operating An Air Conditioning Unit For A Car

Abstract

In an air conditioning unit for a car, which air conditioning unit has a refrigerant circuit with a primary consumer branch having a compressor, condenser, and an evaporator, which air conditioning unit also has at least one auxiliary consumer branch that is connected parallel to the primary consumer branch and has a cold accumulator and its own evaporator, a stop valve is arranged in front of each evaporator. After operational phases charging the cold accumulator, the stop valve of the primary consumer branch is regularly opened for only a predetermined opening time that depends on particular operating parameters. The substantial operating parameters are the air inlet temperature and the air mass flow at the evaporator of the primary consumer branch. The method thus makes possible the alternating charging operation of the cold accumulator parallel to the cooling mode at low air temperatures at the evaporator of the primary consumer branch. By limiting the opening time for the stop valve of the primary consumer branch, no more than a suitable amount of liquid refrigerant accumulates in the evaporator of said primary consumer branch. As a result, the air temperature at the evaporator does not decrease further after the stop valve in the primary consumer branch was closed. For this reason, it is possible to select the lower limit temperature of 3° C. as the criterion for closing this stop valve.

Dependencies are inferred from the claim text.