Superpowerful combined cycle power units with one gas turbine

Abstract

This paper deals with different ways to increase the unit capacity of combined cycle power plants (CCPP) with an in-line equipment layout using a single gas turbine. The transition to a double flow gas turbine using a low-speed low pressure compressor connected with a low-speed steam turbine is a revolutionary way to solve the above problem. The double-shaft compressor is commonly designed with two additional internal bearings and is offered as a solution. The first stages of such a compressor (low pressure compressor (LPC)) connect with the steam turbine, but the second high-pressure group of stages (high-pressure compressor (HPC)) is driven by the gas turbine. So the gas turbine unites a start-up at the base of the HPC. The low pressure compressor and steam turbine can be designed with low revolution speed, which considerably increases air flow through the compressor and leads to an increase in the combined cycle power plant’s power capacity.