2. This tutorial is a PowerPoint ® file which includes recorded narration. Automatic slide sequencing is coupled to the sound track. For the most effective use, please ensure that your computer is equipped with a sound card and that it is activated. If you cannot hear this message from your computer’s speakers, please connect them. Should there be an excessive delay between slides, press the spacebar to proceed.

3. Effect of Fuel Gas Heating on Power Plant Performance One technique utilized to enhance combined cycle power plant performance is to heat the gas turbine fuel gas. Heat is extracted from somewhere in the cycle and used to raise the temperature of the fuel yielding an improvement in net plant heat rate. Typically, this technique is employed where efficiency is a key factor, and advanced gas turbines have firing temperatures above 2300°F (1260°C) are used. Additionally, many DLE combustion systems require fuel at moderately high temperatures

4. Siemens-Westinghouse 501F gas turbine with turbine cooling air pre-cooler

23. We will now evaluate three different techniques to improve plant efficiency by heating the gas turbine’s fuel 1.Use of turbine cooling air precooler as source 2.Use of IPE water as source 3.Split turbine cooling air pre-cooler source – portion to heat fuel, balance to IPB Assume fuel supply is at 77°F and heated to be delivered to control valve at 365°F

24. FUEL Heat Rejection We will now evaluate three different techniques to improve plant efficiency by heating the gas turbine’s fuel 1.Use of turbine cooling air precooler as source

27. 365 100

28. FUEL IPE2 Deaerator We will now evaluate three different techniques to improve plant efficiency by heating the gas turbine’s fuel 1.Use of turbine cooling air precooler as source 2.Use of IPE water as source

32. 100 0

33. FUEL IPS 1 IPE 2 We will now evaluate three different techniques to improve plant efficiency by heating the gas turbine’s fuel 1.Use of turbine cooling air precooler as source 2.Use of IPE water as source 3.Split turbine cooling air precooler source – portion to heat fuel, balance to IPB

34. 100

38. Summary Spreadsheet

40. A few words of caution - Thermoflow’s predictions of the available CA precooler heat from a given gas turbine are inferred, not directly obtained from the vendor’s specifications, and therefore not as reliable as power, heat rate, exhaust flow, and exhaust temperature predictions With this inferred information, the program can estimate the total amount of heat that the CA precooler can provide, but not the temperature at which it can be supplied. Generally, the higher the temperature of the receiving stream to which the heat is transferred, the smaller is the fraction of the CA precooler heat that can actually be delivered to that stream. The user is advised to consult with the gas turbine vendor to determine if the desired heat recovery from the CA precooler can be truly achieved with the selected engine.

41. Fuel Heating Summary Overall plant net efficiency improves ~ 0.5%. Gas turbine power is slightly reduced. Must look at impact of fuel gas heating on all costs - Gas turbine, Steam equipment (HRSG, steam turbine, condenser, piping, etc.), Civil & Mechanical works, Installation. For gas turbines where turbine cooling air pre-coolers are available, additional steam generating capability may be utilized to improve steam turbine performance. Always run Base Case to make true evaluation.