PROJECT: Boiler Steam Blowdown Heat Recovery System

A west coast state prison facility received authorization within their budget to implement energy savings projects. The engineering services team was part of a recent resurrection of their co-generation unit consisting of a Solar Centaur 40 gas turbine and a 46,000 lbs/hr (@ 150 psig saturated steam) Heat Recovery Steam Generator (HRSG). The boiler blowdown steam from the HRSG (used to maintain water chemistry) was discharged through a failing steam flashtank system, mixed with cold utility water because of limited discharge temperature requirements, and flushed into the utility sewer system.

Engineering services was asked to be the design engineer for the replacement of the flashtank system. Therefore, work was performed to research and find a heat recovery system that would return approximately 90% of the previously lost heat to the condensate makeup water system thus reduce duct burner fuel use for supplemental firing on the HRSG steam production. Additional, savings were returned by eliminating the need to waste the site's dependancy on the utility water to cool the blowdown steam prior to discharge into the sewer system.

A design specification, material ordering, supervised construction were completed, and successful commisssioning of this new system.