Gas Turbine Life Limiting Effects Of Inlet And Interstage Water Injection.
Power enhancement technologies for gas turbines such as inlet fogging, interstage water injection, saturation cooling, inlet chillers, and combustor injection are being used by end users without evaluating the potentially negative effects these devices may have on the operational integrity of the gas turbine. Specifically, the effect of these add-on devices, off-design operating conditions, nonstandard fuels, and compressor degradation/fouling on the gas turbine’s axial compressor surge margin and aerodynamic stability is often overlooked. However, aerodynamic axial compressor instabilities caused by these factors can be directly linked to blade high-cycle fatigue and subsequent catastrophic gas turbine failure. A careful analysis should always proceed the application of power enhancement devices, especially if the gas turbine is operated at extreme conditions, uses older internal parts that are degraded and weakened, or uses nonstandard fuels. This paper discusses a simple method to assess the major factors that affect the aerodynamic stability of a single shaft gas turbine’s axial compressor. As an example, the method is applied to a frame type gas turbine, and the results are presented. These results show that inlet cooling alone will not cause gas turbine aerodynamic instabilities, but it can be a contributing factor if, for other reasons, the machine’s surge margin is already slim. The approach described herein can be employed to identify high-risk applications and bound the gas turbine operating regions to limit the risk of blade life reducing aerodynamic instability and potential catastrophic failure.
Analyze of gas turbine performances with the presence of the steam water in the combustion chamber
The role of gas turbine m the nuclear and conventional power industries has received considerable attention over the past several decades. However, in order to improve the performances of gas turbine, different methods such as regeneration, intercooler intermediate, pre-heating and injection of the steam water have been used. This later method is the more beneficial to increase efficiency. The steam water injection at the upstream of the combustion chamber has been proposed. The main purpose of the present work is to analysis the effect of the environmental conditions on the thermodynamic cycle processes of gas turbine, by using analytical relations. The quantity of water vapor carry' through will be injected only when the ambient conditions become higher than standards. The influence of inlet temperature and pressure, ambient temperature and the combustion comber temperature over a wide operating range are evaluated. Design data of an industrial gas turbine are employed to show the variation of injected steam water. The results obtained of infection are in good agreement with the qualitative variation of these, conditions in the case of normal operation without infection of the steam. For better illustration of the physical phenomena, the results are represented in the form of curves into both two and three dimensions.
Target of inhibition by the anti-lipogenic antibiotic cerulenin of sterol synthesis in yeast.
Abstract The antibiotic cerulenin inhibited the incorporation of 14 C-acetyl-CoA by 67% at a concentration of 9 × 10 −6 M but not that of 14 C-HMG-CoA into the non-saponifiable fraction in a cell-free extract of Saccharomyces cerevisiae . Cerulenin markedly inhibited the activity of partially purified HMG-CoA synthase. No inhibition of acetoacetyl-CoA thiolase activity was observed in the same preparation of HMG-CoA synthase. Therefore, cerulenin inhibition of overall sterol synthesis may be accounted for by the specific inhibition of HMG-CoA synthase activity.