Development of the circulating composition sensing circuit for a multiple split type air conditioner with R-407C

摘要

A composition sensing circuit (C.S. circuit) which detects the circulating composition of R-407C in the refrigeration cycle has been developed. The C. S. circuit consists of a heat exchanger, a capillary tube, two temperature detectors and onepressure detector. In the C. S. circuit, the circulating composition is indirectly detected from the temperature and pressure information using vapor-liquid equilibria for R-32/R125/R134a mixtures. The experiments were carried out to evaluate thecirculating composition detection accuracy of the C.S. circuit. The results showed that the detection accuracy of R-32 and R-125 were within 1%, and that of R134a was within 2%. This accuracy is satisfactory for performance stabilization and reliabilityimprovement of the multiple split type air conditioners with R-407C.