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A combined cycle is characteristic of a power producing engine or plant that employs more than one thermodynamic cycle. Heat engines are only able to use a portion of the energy their fuel generates (usually less than 50%). The remaining heat (e.g. hot exhaust fumes) from combustion is generally wasted. Combining two or more "cycles" such as the Brayton cycle and Rankine cycle results in improved overall efficiency. It can also work with the Otto, diesel, and Crower cycles which may allow it to be suited to automotive use. Aside from the Rankine cycle, the Stirling cycle could also be used to re-use waste heat in automotive or aeronautical applications, for the simple reason that there is less weight (water) to carry and that stirling engines or turbines can be made to operate with low temperature differences.
In a combined cycle power plant (CCPP), or combined cycle gas turbine (CCGT) plant, a gas turbine generator generates electricity and the waste heat is used to make steam to generate additional electricity via a steam turbine; this last step enhances the efficiency of electricity generation. Most new gas power plants in North America and Europe are of this type. In a thermal power plant, high-temperature heat as input to the power plant, usually from burning of fuel, is converted to electricity as one of the outputs and low-temperature heat as another output. As a rule, in order to achieve high efficiency, the temperature difference between the input and output heat levels should be as high as possible (see Carnot efficiency). This is achieved by combining the Rankine (steam) and Brayton (gas) thermodynamic cycles. Such an arrangement used for marine propulsion is called Combined Gas (turbine) And Steam (turbine) (COGAS).
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What are some examples of a stationary combustion turbine?
Industrial gas turbines differ from aeroderivatave in that the frames, bearings, and blading is of heavier construction. Industrial gas turbines range in size from truck-mounted mobile plants to enormous, complex systems. They can be particularly efficient--up to 60%--when waste heat from the gas turbine is recovered by a heat recovery steam generator to power a conventional steam turbine in a combined cycle configuration. They can also be run in a cogeneration configuration: the exhaust is used for space or water heating, or drives an absorption chiller for cooling or refrigeration. A cogeneration configuration can be over 90% efficient. The power turbines in the largest industrial gas turbines operate at 3,000 or 3,600 rpm to match the AC power grid frequency and to avoid the need for a reduction gearbox. Such engines require a dedicated enclosure, both to protect the engine from the elements and the operators from the noise. Simple cycle gas turbines in the power industry require smaller capital investment than either coal or nuclear power plants and can be scaled to generate small or large amounts of power. Also, the actual construction process can take as little as several weeks to a few months, compared to years for base load power plants. Their other main advantage is the ability to be turned on and off within minutes, supplying power during peak demand. Because they are less efficient than combined cycle plants, they are usually used as peaking power plants, which operate anywhere from several hours per day to a couple dozen hours per year, depending on the electricity demand and the generating capacity of the region. In areas with a shortage of base load and load following power plant capacity, a gas turbine power plant may regularly operate during most hours of the day and even into the evening. A typical large simple cycle gas turbine may produce 100 to 300 megawatts of power and have 35-40% thermal efficiency. The most efficient turbines have reached 46% efficiency.[2]
Which of the following can be called non-conventional source of energy?
The non-conventional sources of energy are: 1. Wind Energy advantages- non-polluting; low cost production of electricity once setup; safe and clean disadvantages- noise pollution; wind mills costly to setup; disturbs radio and T.V. reception; harmful to birds. 2. Solar Energy advantages- inexhaustible; non-polluting disadvantages- expensive; diffused source, so gets wasted. 3. Tidal Energy advantages- non-polluting; inexhaustible disadvantages- destroys wildlife habitat; difficult to harness 4. Nuclear energy advantages- Emits large amount of energy disadvantages- generates radioactive waste; expensive 5. Bio Gas advantages- low cost; easy to operate; makes use of bio waste disadvantages- causes green house effect 6. Geothermal Energy advantages- clean Eco friendly and always available disadvantages- located far away from cities and so costly to transport the electricity
Describe the role of steam in a nuclear power plant?
In a nuclear power plant, steam is generated by heat produced from the nuclear fission reaction. This steam is used to spin turbines connected to generators, producing electricity. The steam is then condensed back into water and reused in a continuous cycle.
What are the relative advantage of Rankine Cycle over Carnot Cycle in thermal power plants?
Rankine cycle allows for practical implementation with real working fluids such as water, making it more feasible for thermal power plants compared to the idealized Carnot cycle. Rankine cycle also allows for the use of turbines and pumps which are more efficient than isothermal expansion and compression processes in the Carnot cycle. Additionally, Rankine cycle can be modified with reheating and regeneration to improve efficiency further, something the Carnot cycle cannot achieve.
Why is steam used to turn the turbines in power stations?
Steam is used in power stations to turn turbines because it has a high energy content and can generate significant mechanical power when flowing through the turbine blades. The steam is produced by heating water with the help of a heat source, such as burning fossil fuels or nuclear reactions, which drives the turbine and subsequently generates electricity through a generator. This process is known as the Rankine cycle and is a common method for converting heat energy into mechanical energy.
How is energy lost by combined cycle gas turbines?
umm no idea haha
What is the explanation for the internet shopping trade cycle?
what is the Advantages and disadvantages of consumer e-Commerce? answer it....
What are the advantages and disadvantages of Otto cycle?
advantages: when you turn on the windshield wipers you get a free ray gun. disadvantages: when you push the key in the ignition, it is actually a trigger for self destruction
Disadvantages of sdlc?
advantages and drowbacks of following a life cycle approach to information system development?
What are the advantages and disadvantages of communication cycle?
a disavantage is that sometime someone will not understand the message so when you get feedback that answer might show they have misunderstood therefor the cycle is in one way not completly effective.
What are the advantages and disadvantages of chopping down rainforest's?
There are no advantages I can see for taking down the rainforest. The disadvantages are that nothing else will grow there, that by removing trees you may loose future plants that will cure people of disease, the animals no longer will have a home, that the rain forest acts as part of the water cycle and that messes up the water cycle when you cut it down.
What are the disadvantages and advantages of dynamic system development method?
Advantages of system development life cycle in terms of waterfall model it only requires minimal resources in implementing this method. But it is hard to go back and change.
What are advantages and disadvantages of product life cycle?
What are advantages and disadvantages of product life cycle?In: http://wiki.answers.com/Q/FAQ/1866[Edit categories]The product life cycle is all estimated so anything can go wrong as it is all estimated. A product life cycle is not very helpful for future events and it suggets that all products are predictable. It is usually very dificult to attribute a timescale to the PLC and it does not always recognise life cycles are getting shorter.by Yousaf
How is recent combination cycle gas turbines lost?
factorys
What are the advantages and disadvantages of the product life cycle theory?
The intended advantage of product life cycle theory is to maximize the profitability of the product. A few disadvantages are that sometimes products can see a revival in sales which the theory does not take into account. In addition, the theory doesn't take into account product redesign potential.
What are the advantages and disadvantages of a traditional system life cycle?
Well, honey, the advantage of a traditional system life cycle is that it's like following a recipe - you know exactly what ingredients you need and when to add them. But, on the flip side, it can be as exciting as watching paint dry, with its rigid structure and lack of flexibility. So, if you're into playing by the rules and don't mind a little predictability, go ahead and embrace the traditional system life cycle.
What are the advantages and disadvantages of life cycle analysis and product costing?
The advantages of the product life cycle concept is that it provides a basic structure that allows you to see where you are, and what lies ahead. R u doing ur ICDM assignment? I may help u..pls contact 0134002000...Mr Lim.
