2 Scope

While the main focus on water and steam chemistry in the new combined cycle plant is on the HRSG and steam turbine, chemistry limits are also important for water that is used to cool air feeding the gas turbine and water directly injected into the gas turbine. The limits suggested herein address all these water uses in a combined cycle plant. Small, low pressure HRSGs operating with soft water makeup are included in the document, although the suggested chemistry limits for these units are the same as for industrial watertube boilers. This document does not cover HRSGs used for enhanced oil recovery or thermal in-situ operations.