Optimizing gas turbine performance with precise humidity measurements - VAISALA - #1

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Optimizing gas turbine performance with precise humidity measurements Ensuring gas turbines run at maximum efficiency is a primary goal for operators. In the current economic climate, anything that increases productivity, and hence profit, is clearly welcome. From an environmental point of view, it is also important that turbines run as efficiently – and produce as few emissions – as possible. Fortunately, there are several ways to improve gas turbine output. Controlling the humidity and temperature of air entering the combustion inlet is one of the most important, as it has a direct effect on the turbine’s efficiency, emissions, and operational reliability. / APPLICATION NOTE Cooler, denser air increases output and efficiency In terms of gas turbine efficiency, the effect of air density is well known: denser intake air increases mass flow rate, which consequently results in improved turbine output and efficiency. Air density is inversely proportional to temperature, meaning that rising temperatures decrease air density and therefore reduce gas turbine efficiency and power. Inlet-air cooling, especially in warm and hot environments, is commonly used to compensate for the efficiency loss caused by high air temperature. Even a small reduction in air temperature can lead to a significant increase in power output. A 1°C reduction in air temperature can increase output by up to 0.5%. There are several techniques that are used to cool intake air. A common solution is a fogger, a system that injects water into the airflow through nozzles, causing the air to cool as the water droplets evaporate.