The Coal-Fired PFBC Machine: Operating Experience and Further Development
The key components of Pressurized Fluidized Bed Combined Cycle (PFBC) plants are the specially designed gas turbine, which we refer to as the PFBC machine, and the pressurized fluidized bed boiler used to generate and superheat steam for expansion in a steam turbine, in ABB’s P200 and P800 modules, ABB Stal’s 17 MWe GT35P and 70 MWe GT140P machines, respectively, are used. Particulate cleanup before expansion in the turbine sections is with cyclones. So far, over 70,000 hours of operation has been accumulated on P200 modules in the world’s first PFBC plants, demonstrating that PFBC meets the expectations. The GT35P machines have been found to perform as expected, although some teething problems have also been experienced. The next P200 plant will be built in Germany for operation on brown coal. The first GT140P machine has been manufactured. After shop testing in Finspong, it will be shipped to Japan for installation in the first P800 plant, which is under construction. Future development of the PFBC machines are foreseen to include raising the turbine inlet temperature through combustion of a topping fuel in order to reach thermal efficiencies which ultimately may be in the range of 50 to 53% (LHV).