PDF Publication Title:
Text from PDF Page: 010
HFC refrigerants Resulting design and construction criteria Suitable compressors are required for R134a with a special oil charge and adapt- ed system components. The normal metallic materials used in CFC plants have also been proven with ester oils; elastomers must sometimes be matched to the chang- ing situation. This is especially valid for flex- ible hoses where the requirements call for a minimum residual moisture content and low permeability. The plants must be dehydrated with particu- lar care and the charging or changing of lubricant must also be done carefully. In addition relatively large driers should be provided, which have also to be matched to the smaller molecule size of R134a. Meanwhile, many years of very positive experience with R134a and ester oils have been accumulated. For this refrig- erant, BITZER offers an unequalled wide range of reciprocating, screw and scroll compressors. Converting existing R12 plants to R134a At the beginning this subject was discussed very controversially, several conversion methods were recommended and applied. Today there is a general agreement on technically and economically matching solu- tions. The characteristics of ester oils are very favourable here: Under certain conditions they can be used with CFC refrigerants, they can be mixed with mineral oils and tol- erate a proportion of chlorine up to a few hundred ppm in an R134a system. The remaining moisture content has, how- ever, an enormous influence. Very thorough evacuation (removal of remaining chlorine and dehydration) is therfore essential, as well as the installation of generously dimen- sioned driers. There is doubtful experience with systems where the chemical stability was already insufficient with R12 operation e.g. with bad maintenance, small drier capacity, high thermal loading. Increased deposition of oil decomposition products containing chlorine is found often. These products are released by the influence of the highly polarized mixture of ester oil and R134a and find their way into the compres- sor and control devices. Conversion should therefore be limited to systems which are in a good condition. Restrictions for R134a in mobile air conditioning (MAC) systems An EU Directive on "Emissions from MAC systems" bans the use of R134a in new systems. Various alternative technologies are already in use. For further explanations see pages 11 and 36). Supplementary BITZER information concerning the use of R134a (see also https://www.bitzer.de) o Technical Information KT-500 „BITZER refrigeration compressor oils for reciprocating compressors“ Fig. 10 R134a/R12/R22 – comparison of pressure levels 10PDF Image | REFRIGERANT REPORT 21
PDF Search Title:
REFRIGERANT REPORT 21Original File Name Searched:
A-501-21_EN.pdfDIY PDF Search: Google It | Yahoo | Bing
CO2 Organic Rankine Cycle Experimenter Platform The supercritical CO2 phase change system is both a heat pump and organic rankine cycle which can be used for those purposes and as a supercritical extractor for advanced subcritical and supercritical extraction technology. Uses include producing nanoparticles, precious metal CO2 extraction, lithium battery recycling, and other applications... More Info
Heat Pumps CO2 ORC Heat Pump System Platform More Info
CONTACT TEL: 608-238-6001 Email: greg@infinityturbine.com (Standard Web Page)