Copper tubing in your condensers or feedwater heaters can be a problem when optimizing the cycle chemistry to protect the carbon and alloy steels. Ammonia additions for increasing pH also attack copper’s protective layer, decreasing the tubes life. Copper alloys have been thought to have higher thermal conductivity than stainless or titanium alloys, so the assumption has been that if a plant switches, it will have a negative impact on heat rate. That may not be the case as the copper protective layer is much thicker and more thermally resistive than the other alloys. Additionally, copper alloys have a limited lifespan and can be easily damaged by a number of mechanisms causing forced outages and derates. This paper provides a tool and options using financial justifications when considering replacing your copper based condenser tubing. It is based on the HEI 10th Edition Standard for Condenser Performance. It also provides an option for cooling water uprates that can provide a very significant performance payback that would not be possible with the copper alloy.
Author: Dan Janikowski