Fuel Gas Conditioning System Modularization and Optimization

Siemens Energy, Inc. has developed a modular approach that standardizes the components and configuration of the fuel gas conditioning system, while allowing for customization to meet site-specific requirements. The intent of this approach is to: • Lower engineering costs (design only has to be done once). • Allow for interchageability (long-lead components purchased for one project can be used on another project if necessary). • Simplify installation and commissioning at the site. In the past, fuel gas conditioning system components have been purchased from various suppliers. In cooperation with these suppliers we developed a modular fuel gas conditioning system that would lower engineering costs, standardize design, and allow for interchageability of components. The result was the development of three standard fuel gas conditioning systems that accommodate several combined cycle power plant sites. Design 1 is for sites that require compression, but no pressure regulation. Design 2 is for sites that require regulation, but little or no compression. Design 3 is for sites that require both compression and pressure regulation. Site specific customization is minimized, since the standard designs encompass most of the foreseen site conditions. We have developed control technologies to accommodate high variability in site gas pressures and minimize the impact of pressure spikes. We also reviewed the optimum placement of the compressor gas cooler. Installing the cooler in the recycle stream rather than as an aftercooler can reduce capital costs. Additionally, this configuration improves gas turbine heat rate. This paper will describe in detail the design of the fuel gas conditioning system, the various applications, and the benefits to the customer.