What is the effect of reheat in gas turbines?
What is the effect of reheat in gas turbines?
Effect of reheating: This increases the work output of the turbine by keeping the compressor work constant. The mean temperature of heat rejection is also increased, resulting in a decrease in the thermal efficiency of the plant. For a given power output, the fuel consumption rate decreases.
What are the disadvantages of reheating?
Disadvantages of Reheating: 1- Reheating requires more maintenance. 2- The increase in thermal efficiency is not appreciable in comparison to the expenditure incurred in reheating.
What are the effects of reheat cycle?
The reheat cycle increases the turbine work and consequently the net work of the cycle. This is accomplished not by changing the compressor work or the turbine inlet temperature but instead by dividing the turbine expansion into two or more parts with constant pressure heating before each expansion.
What is the effect of reheat on the cycle efficiency?
The Rankine cycle performance and efficiency can be improved with the reheat cycle as well as by regenerative cycle. It can be improved by increasing the thermodynamic properties of the steam entering into the turbine. At the initial stage, increased pressure results in increased expansion ratio.
What is the effect of reheat on system quality?
Explanation: Reheat increases work output.
What is effect of reheat and regeneration on efficiency?
Abstract. Reheating in a reheat regenerative steam power cycle increases efficiency by increasing the average temperature of heat reception, but also increases the irreversibility of feed water heaters by raising the temperature of the superheated steam used for the regenerative process.
What is a reheat turbine?
Reheat turbines are also used almost exclusively in thermal power plants. All turbines that have a high-pressure turbine and low-pressure turbines use a steam reheat between these stages. Reheat allows delivering more heat at a temperature close to the cycle’s peak (i.e., thermal efficiency increases).
What is the effect of reheat on steam quality?
In case of two reheats, steam is super-heated twice at different constant temperatures. A high reheat pressure increases the the moisture content at turbine exhaust which results in scaling and it should be optimised. Thus the work produced is increased ,thereby efficiency increases.
What is the effect of decrease of reheat pressure on the quality of steam at turbine exhaust?
7. What is the effect of decrease of reheat pressure on the quality of steam at turbine exhaust? Explanation: For too low a reheat pressure, the exhaust steam may even be in the superheated state which isn’t good.
What is the effect of reheat on steam quality A increases?
Why reheat system improves efficiency?
A high reheat pressure increases the the moisture content at turbine exhaust which results in scaling and it should be optimised. Thus the work produced is increased ,thereby efficiency increases.
What is the purpose of reheating?
The main purpose of reheating is to avoid excess moisture in steam at the end of expansion to protect the turbine.