（全是英文）What is the basic start up sequence of a gas turbine steam
本帖最后由 yinalan 于 2017-10-31 21:26 编辑Quora 上搬过来的，大家看看，感觉不错的大侠，给评分，给俺多些动力搬更多:lol
Ensure all Safetys are acknowleged.
All sub support utilities are online and ready (Compressed Air, Water for Cooling or NOx Reduction, Power Supplies).
Press the Start button.
Hydraulic Pumps turns the Hydraulic Motor to bring Gas Turbine up to speed. After 66% Engine Speed the Turbine Bleed Valve closes equalizing all Stages of the Compressor and Exhaust Stages and the Turbine can sustain itself...if not it will go into Stall and Fail start-up.
Beforw reaching 100% Turbine Engine Speed the Generator Field is Flashed to energize the Electrical Field.
The sprague clutch is over ridden and the Turbine reaches 100% Engine Speed.
Once the Turbine reaches 100% the Heat Recovery diverters slowly adjust open to direct Heat to the Boiler Section. Once the Boiler Pressure increases past 25% Load the Main Generator Breaker can be Closed and provide Power to your Facility.
It is now safe to establish Water Injection to the Gas Turbine for NOx Reduction because it will not Flameout as long as the Turbine is running at 100% Engine Speed.
The Steam Pressure should now be reaching maximum Steam Pressure Setpoint and the Diverters will noticeably backoff to maintain setpoint.
Once you have a good Steam Supply you can now bring online the Steam Turbine.
Reset all Safety Trips. Open the Steam Turbine Chest valves to remove all built up Condensate. As the drainings become full steam and no water -you can close the Turbine Chest Valves and the Turbine should begin to build momentum and increase in RPM.
Once at 50% speed the Governor can be reset and Turbine will reach 100%.
You should now be burning Fuel to sustain the Gas Turbine whichs is providing Electrical Power. And building Steam Pressure to sustain the Steam Turbine for either Electrical Generation, Building Heating and Cooling or Compressor Operation. Here is what General Electric says : “ This is how a combined-cycle plant works to produce electricity and captures waste heat from the gas turbine to increase efficiency and electrical output.
Gas turbine burns fuel.The gas turbine compresses air and mixes it with fuel that is heated to a very high temperature. The hot air-fuel mixture moves through the gas turbine blades, making them spin.The fast-spinning turbine drives a generator that converts a portion of the spinning energy into electricity.
Heat recovery system captures exhaust.A Heat Recovery Steam Generator (HRSG) captures exhaust heat from the gas turbine that would otherwise escape through the exhaust stack.The HRSG creates steam from the gas turbine exhaust heat and delivers it to the steam turbine.
Steam turbine delivers additional electricity.The steam turbine sends its energy to the generator drive shaft, where it is converted into additional electricity.” Why does a steam turbine have more efficiency than a gas turbine?
This question is honestly a good question, even if it's like comparing rice and noodles. I think the answer can be found in the current technical limitations for each base component of such plants. But this comparison needs a bit of background to have a solid comparison.
Let us assume we compare a heavy-duty gas turbine simple cycle plant and a heavy-duty steam turbine plant (fired with whatever and without considering district heating), similar power output and both designed for 20 years base-load operation, state of the art aero design as well as an economical and competitive operation. The GT is usually designed for Combined Cycle operation, hence the GT exhaust delivers enough heat and pressure for a HRSG.
The efficiency limit on the steam plant is mostly given by the last low pressure stages, where the steam gets wet. The more water drops are in the steam, the more the blades suffer from pitting corrosion/erosion. Complex hydrodynamic flows as well as materials are limiting to get to lower pressures. The best steam plants have an efficiency above 46%. (e.g. Lünen in Germany, hard coal fired STPP operated by Trianel)
The best heavy-duty gas turbines in simple cycle have an efficiency of 42% (aeroderivatives better then combined cycle designed GT). The limit on the gas turbines is the temperature capability of the turbine inlet section (front turbine rows). The reason why GT have such high lambda values (stoichiometric air to fuel ratio) is mainly not the combustion stability or the emissions. It's limited by the material temperature limits, which limits the efficiency. 看不太懂，谁给翻一下？？ 这个写得很笼统，没有细节描述。只是科普科普。
光是盘车都要一个多小时。
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