Paper 3: Boiler Feed Pump Design for Maximum Availability

Abstract

With increasing size of turbo-generator sets, the criterion of maximum availability for boiler feed pumps has assumed even greater importance. Capital cost, power consumption, and availability are all necessary considerations in the economic optimization of power-generation equipment design. The capital and running costs of the boiler feed pump are relatively small compared to the plant for which it is an auxiliary. However, such plant depends implicitly for its revenue-earning capacity on the reliability of the boiler feed pump. Awareness of these overall economic considerations has led to the maximum availability design concept for large boiler feed pumps.To achieve these ends, a high-speed, rigid-rotor design concept has been evolved which permits the machine to continue in satisfactory mechanical operation under vapour-locked conditions. A new cartridge principle of pump construction has been introduced, wherein the complete internal assembly, incorporating end covers and bearings, is withdrawn as a single unit leaving the casing in situ.The extensive research and development carried out to prove the individual features of the design are fully described, together with particulars of the complete prototype machine, which at the time of writing is believed to be the highest stage pressure boiler feed pump in commercial operation in any power station throughout the world.