Analyse et développement du réglage d'un système de conditionnement d'air équipé de compresseurs volumétriques à régulation externe et d'un détendeur automatique.

One of the aims of new car air-conditioning systems is to reduce the impact on fuel consumption without penalizing cabin thermal comfort. One way to reduce fuel over consumption is to use a variable external controlled compressor. These compressors can vary their displacement in order to reach a fixed level of thermal comfort inside the cabin, giving, in all the working conditions, the right refrigerant capacity without the need for reheat. A variable external controlled compressor coupled with an expansion valve generates fluctuations on cooling power (hunting), that have a negative impact on thermal comfort, on consumption, and on compressor reliability. This paper describes the development of a compressor control that eliminates these fluctuations.