Material issues with the heat exchangers in the ammonia system
Thread Content
For ammonia refrigeration systems using calcium chloride brine, a heat exchanger is required; the tubes of this heat exchanger should be made of TP2 copper. Is it really necessary to use copper? Some people say it is prone to corrosion, but there are units that have been in use for many years without any problems. Additionally, can alternatives such as aluminum or stainless steel be used instead of copper?
Copper has a high heat transfer coefficient, but it will definitely react with ammonia, albeit slowly. If a large heat exchange area is required, a lot of stainless steel materials may be needed. At this point, the advantages of plate heat exchangers made of aluminum alloy become quite evident.
It’s made of aluminum, so isn’t it more prone to corrosion? Aluminum is more reactive than copper, right?
The metallic activity of aluminum is manifested in its reaction with acids; this problem does not occur with ammonia
Ordinary stainless steel cannot be used for calcium chloride brine heat exchangers, as chloride ions cause severe corrosion of stainless steel.