Simplified Monitoring Technique of HFC Mixed Gases in a Coolant Recycle System

Abstract

Luminescence of dye-sensitized polymer films was investigated to develop a phosphor-based film sensor for hydro fluorocarbon (HFC) gases. The film shows a broad emission band at 560 nm. By flushing the HPC, the spectrum is drastically quenched by a factor of 500 in intensity, relative to new film. From infrared absorption spectra and experiments using reference films, this distinct quenching is ascribed to structural changes of the dye molecules. The findings give a clue towards developing on-site monitoring techniques for HFC mixed gases. Recently, a greenhouse gas effect has been caused by the Freon® substitutes (hydrofluorocarbon: HFC). This effect has now resulted in increased impact. Since HFC gases do not contain a chloride component, they are free of an ozone depletion effect. Therefore, HFCs are now used widely as Freon® substitutes in cooling facilities. Usually, HFC gas mixtures are chemically detected using gas chromatography (GC), mass spectrometry (MS), electron capture (ECD), or atomic emission (AE). Detection limits for HFC gases are ng by ECD, and pg by MS, AED technology. These methods are expensive and unable to be implemented in real time. There is a strong practical need to develop an on-site monitoring system for coolant gas mixtures in their various states that can be manufactured at a reasonable cost.