OR-20-025 -- Development of New Accelerated Corrosion Test(s) for All-Aluminum Microchannel and Tube and Fin Heat Exchangers--Part I: Comprehensive Literature Review ✓ Most Recent

An exhaustive and comprehensive literature search wasdone on various laboratory testing methods to assess performanceof all-aluminum microchannel heat exchangers andtube and fin heat exchangers. Cabinet style and electrochemicalaccelerated corrosion testing methods as well as lesscommon corrosion tests are reviewed and attributes of eachgroup of testing methods are provided. Literature reviewrevealed that test parameters used in most accelerated corrosiontests such as temperature, concentration of corrosiveagents, and relative humidity are intentionally selected toduplicated the most aggressive environments. The idea is thatif a heat exchanger can survive harsh corrosive environment,it can survive milder environments. Among the standard testprotocols the tests most used are Sea Water Acid AcceleratedTest (SWAAT)] and Copper Accelerated-Acid Salt Spray Test(CASS). SWAAT appears to be used most in North America andEurope, while CASS is more popular in Japan. Currently, thereis no test method that includes impact of operational parameterssuch as duty cycle on corrosion of heat exchangers. Heatexchanger manufacturers perform their propriety corrosiontest protocols which makes performance comparison of variousproducts impractical. It was concluded that electrochemicaltesting used in the past utilizes corrosion potential that isa thermodynamic parameter and does not provide any insightin the kinetics of corrosion therefore the parameter has a verylimited use for HVACR industry. Newly designed acceleratedcorrosion test should have a well defined and measurableparameter resulting in an unambiguous characterization of thesystem being tested. Part II of this work will focus on ISO 9223standard (Corrosion of metals and alloys - Corrosivity of atmospheres- Classification, determination and estimation). See more