How are gas turbines cooled?
Fogging. Inlet air fogging consists of spraying finely atomized water (fog) into the inlet airflow of a gas turbine engine. The water droplets evaporate quickly, which cools the air and increases the power output of the turbine.
What is reheating and regeneration of gas turbine?
Reheating is applied in a gas turbine in such a way that it increases the turbine work without increasing the compressor work or melting the turbine materials. A reheater is generally is a combustor which reheat the flow between the high and low pressure turbines. In jet engines an afterburner is used to reheat.
What happens in gas turbine with regeneration?
It was found that adding regeneration to the simple gas turbine cycle results in an increase in the thermal efficiency of cycle. It was also found that including regeneration in gas turbine cycle results in an increase in the output power of the cycle, and it results in a decrease in the exhaust gas temperature.
Why both reheating and regenerating is used together?
Explanation: When vaporization pressure is high, the reheating of steam is adopted. 2. Why both reheating and regeneration is used together? Explanation: Thus a modern steam power plant has both reheating and regeneration.
What is difference between reheating and regeneration?
Reheating of steam improved the thermal efficiency of the plant, net work output of turbine, reduction in blade erosion (or quality of steam improve). By regeneration thermal efficiency of the plant can be increased but it does not affect work output from turbine.
What is reheat in gas turbine?
In a gas turbine, reheating is a process in which the hot gases coming out of the combustion chamber expands in two turbines i.e. high pressure and low pressure turbine. The hot gases firstly expands in a high pressure turbine then passes through a heat exchanger and then expands in the low pressure turbine.
Why regenerator is used in gas turbine power plant?
As an exhaust-gas heat exchanger, a regenerator recovers heat from the exhaust and uses it to preheat the compressed air before the compressed air enters the combustor. Thus, regenerators can be used to increase the thermal efficiencies and power outputs of gas turbines.
How can we increase the efficiency of gas turbine?
Therefore, gas turbine efficiency can be improved by cooling the inlet air. This is especially effective in hot, dry climates. A significant benefit of turbine air inlet cooling is that it can reduce (or eliminate) fuel efficiency reduction by evaporative cooling the inlet air to the wet bulb temperature.
What are the disadvantages of gas turbine?
Gas turbines have a very high power to weight ratio and are lighter and smaller than internal combustion engines of the same power….Power Generation/Gas Turbine Power.
| Advantages | Disadvantages |
|---|---|
| Lower operating costs | Overall efficiency of plant is low ≈ 20% because of exhaust gases still containing heat. only efficient in a Combined cycle configuration |
What is a work ratio?
The working ratio measures a company’s ability to recover operating costs from annual revenue. It is calculated by taking total annual expenses, excluding depreciation and debt-related expenses, and dividing it by the annual gross income.
How is work ratio calculated?
To solve this question, you must first add together the two halves of the ratio i.e. 4 + 2 = 6. Then you need to divide the total amount using that number i.e. 600/6 = 100. To work out how much each person gets, you then multiply their share by 100.
What is work ratio in Rankine Cycle?
And the work ratio is defined as the ratio of the net work W to the gross work output Wg, i.e. W/Wg. The Carnot cycle has a low work ratio. In a simple Rankine cycle, steam is used as the working fluid, generated from saturated liquid water (feed-water).
Why Carnot cycle is practically not possible?
Carnot cycles are not encountered in reality since achieving isothermal heat transfer is very difficult (needs very large heat exchangers and long time). Also process 3-4 requires a pump or compressor that can handle two phase mixture (liquid and vapor) which is impractical.
What is Q in Rankine Cycle?
This ‘exhaust’ heat is represented by the “Qout” flowing out of the lower side of the cycle shown in the T–s diagram below. Cooling towers operate as large heat exchangers by absorbing the latent heat of vaporization of the working fluid and simultaneously evaporating cooling water to the atmosphere.