1、 2016 ASHRAE 71This paper is based on findings resulting from ASHRAE Research Project RP-1665.ABSTRACTInstances of counterfeit refrigerants causing violent andunexpected explosions, resulting in multiple fatalities, havebeen reported in mobile refrigeration units around the world.In addition, counte
2、rfeit refrigerants have caused system reli-ability issues in numerous air-conditioning applications. Itwas initially believed the inclusion of methyl chloride (R-40)in the refrigerant composition caused these explosions andreliability issues. ASHRAE Research Project RP-1665 wascommissioned to examin
3、e reactivity of R-40 with R-134a(methylene chloride) refrigeration system materials. R-40reactivity,inconcentrationrangesof0.01%to10%,wasstud-ied in the presence of R-134a, polyolester (POE) lubricant,aluminum 1100 metal, aluminum 380 metal, iron metal,coppermetal,sodiumpotassiumaluminumsilicatezeol
4、ite,andalumina catalysts. R-40 was shown to have varying levels ofreactivitygenerally mild, but showing the potential for cata-strophicreactivity.Thispapercontainsasummaryoftheworkfrom ASHRAE RP-1665 and provides insights into the impactof R-40 contamination by providing the chemistry of the reac-ti
5、ons, preventative safeguards, threshold levels, and assess-ment procedures.INTRODUCTIONThis research investigated the reactivity of R-40 in R-134a with various system materials including polyolester(POE) lubricant and aluminum alloys with and without ironmetal (Fe), copper metal (Cu), sodium potassi
6、um aluminumsilicate zeolite, and alumina (Al2O3) filter drier media. Thisinvestigation was prompted by three fatalities worldwidecaused by the explosion of refrigeration systems thatcontained R-40. A paper by Kujak et al. (2014) documentedvariousR-40issuesexperiencedbytheHVAC these were gas-phase vo
7、latiles determinedby gas chromatographic mass spectroscopy, analysis of thePOE lubricant by gas chromatographic mass spectroscopy,and, on Set 9, only ion chromatographic analysis for chlorideand fluoride. Reaction products of the POE are not discussedin this paper. A summary of all the analyses are
8、contained inthe research summary report and are not completely reportedin this paper.Published in ASHRAE Transactions, Volume 122, Part 2 ASHRAE Transactions 73In addition, a company member represented on the techni-cal review committee provided scanning electron microscopeenergy dispersive x-ray sp
9、ectroscopy (SEM/EDS) analyses onSet 4 coupons and corrosion surfaces that first identified alumi-num fluoride (AlF3) and silicon (Si) as principal reaction prod-ucts. This work first reported the formation of R133a as abreakdownproductofR-134a.TheamountofR133awasmoni-tored in all tests and reported
10、as %R133aFormation. Note thatthe%R133aFormationisnottheweightpercentofR133aintheR-134abutisthepercentpeakareafromthegaschromographic(GC)analysisoftheR133arelativetoitselfplusthepercentGCareaofR-40,or,inotherwords,theamountofR-40contributingto convert to R133a. This calculation technique was usedbeca
11、use R-40 was partially consumed by reaction with POE,andsothetruestmeasureofR-40conversiontoR133awastheirpost-experiment ratio.Table 1. Summary of 11 Experimental Tests and ConditionsExperimentalSetDescriptionRefrigerant Mixture(% by weight in R-134a)Materials Used Test Conditions1Experimental setup
12、 validation andR-40 reaction scoping tests(not reported in this paper)5% R-40 in R-134aUNS Al1100 or UNSAl380Various temperaturesand times2R-40 concentration effectswith aluminum alloys1% to 5% R-40 in R-134aUNS Al1100 or UNSAl38014 days at 347F(175C)3APolished aluminum couponsto remove aluminum oxi
13、de5% R-40 in R-134aUNS Al1100 or UNSAl38014 days at 347F(175C)3B 120 day extended exposure of 3A 5% R-40 in R-134aUNS Al1100 or UNSAl380120 days at 347F(175C)4 Initial catalyst investigations 5% R-40 in R-134aUNS Al1100 or UNSAl380with Fe, Cu, zeolite, orAl2O314 days at 347F(175C)5 Effects of high m
14、oisture (2000 ppm) 5% R-40 in R-134aUNS Al380 with Fe, Cu,zeolite, or Al2O314 days at 347F(175C)6UNS Al380 with Fe catalyst withvarying R-40 concentrations0.1%, 0.5%, and 5%R-40 in R-134aUNS Al380 and Fe14 days at 347F(175C)7UNS Al380 limiting Al2O3withcombination of catalysts0.1%, 0.5%, and 5%R-40
15、in R-134a0.1 g (0.0002 lbs) Al2O3with UNS Al380 and onecatalyst each of Fe, Cu,zeolite or Al2O314 days at 347F(175C)8 UNS Al380 with AlCl35% R-40 in R-134a0.1 g (0.0002 lbs) AlCl3with UNS Al38014 days at 347F(175C)9UNS Al380 with higher levels ofR-40 and catalysts10% and 30% R-40 in R-134a10% R-40 w
16、ith UNSAl380 with Fe, Cu, zeo-lite, or Al2O3and 30% R-40 with UNS Al380 andAl2O314 days at 347F(175C)10UNS Al380 with R-40 at low levelsof Al2O3and catalysts0.01%, 0.05%, 0.1%, 0.5%,and 1% R-40 in R-134a0.5 g (0.001 lbs) Al2O3with and without all threecatalysts14 days at 347F(175C)11UNS Al380 at var
17、ious R-40 levels withFe and catalyst combinations0.01%, 0.05%, 0.1%, 0.5%,1%, and 5% R-40 in R-134aUNS Al380 with Fe at0.01% to 5% R-40 andcombinations of UNSAl380 with catalysts at5% R-40; Al2O3wasactivated by drying at392F (200C)14 days at 347F(175C)Published in ASHRAE Transactions, Volume 122, Pa
18、rt 2 74 ASHRAE TransactionsDISCUSSION OF RESULTSOne of the most interesting facts determined by this workis that R-134a can break down in the presence of R-40 andcatalysts.TheformationofR133ahasneverbeforebeendocu-mented in the literature in R-134a reactions inside HVAC Anonymous 1954) highlight the
19、importance of POE as a radical scavenger.The reaction products found in exploded HVAC thus, the use of uncontaminated refrigerantgas and lubricating oil and adequate maintenance proceduresare essential to the long-term problem-free operation ofmobile HVAC systems.ACKNOWLEDGMENTSThe authors would lik
20、e to acknowledge the efforts of BillLapp, George Hansen, Elyse Sorenson, and Julie Majurin ofIngersollRandforprovidingSEM/EDSanalysisofsamplesofexperimental Set 4.RP-1665 was conducted by McCampbell Analytical Inc.,located in Pittsburg, CA.REFERENCESKujak, S., R. Yost, W. Clough and M. Scancarello.
21、2014.Dangers of counterfeit refrigerants. ASHRAE WinterConference proceeding (New York). Atlanta: ASHRAE.Walker, W.O., and K.S. Willson. 1937. The action of methylchloride on aluminum. Refrigeration Engineering34(126):8990.Clogston, C.C. 1945. Reactions of aluminum & magnesiumwith certain chlorinate
22、d hydrocarbons. CAS 40:1305.Underwriters Lab, Bull research, No. 34, pp. 515.Anonymous. 1954. Violent reaction between AI and chlori-nated hydrocarbons cited. Chemical Engineering News32(18):1824. http:/pubs.acs.org/doi/pdf/10.1021/cen-v032n018.p1824.Hamilton, E. 2014. Examination of the reaction of
23、 R-40 withrefrigeration system materials: R-134a, POE lubricant,Al1100, Al380, and Fe, Cu, zeolite silicate and aluminametal catalysts. ASHRAE Research Project RP-1665.DISCUSSIONRosine Rohatgi, Co-owner/President of Spauchus Associ-ates,Inc.,Clyde,NC:WhatcausedtheexplosionswithR-40?Stephen Kujak: A
24、complete understanding of what led to theexplosion is not known since no forensic investigation hasbeen published around the events. Servicing of the unit wasunderway in each of the events, so some combination ofservicing actions and the reactivity of the trimethylaluminium(TMA) pyrophoric being exp
25、osed to air led to the explosion,an overpressure event occurring from the breakdown productdriven by the reactivity of the R-40, or some other combina-tion of reactive by-products of the R-40 led to compromisingthe pressure rating of the equipment, which led to a suddenrelease of reactive materials, and then the TMA reacted withair that led to the outcome.Published in ASHRAE Transactions, Volume 122, Part 2
