Design And Performance Calculation of a Solar Aided Super Critical Coal Power Plant with Thermal Energy Storage

To reduce fuel costs and to reduce the impact of power generation on the environment, retrofitting traditional coal powered power plants with clean, renewable solar thermal power has been proposed. However, a detailed estimate of the costs and benefits of such a retrofit need to be quantified in the context of the specific plant location and its load profile. This work presents the concept of Solar Aided Power Generation (SAPG), where a conventional coal fired power plant is hybridised with the parabolic trough field. The operation of a 660 MW supercritical coal fired plant in Gujarat, India integrated with solar field of parabolic trough collectors has been designed for part load conditions. A solar field, based on calculations of solar angle is proposed. A comparative study of both North-South alignment and East-West alignment has been made. The main feature of this hybrid system is the molten salt carrying the solar energy. The energy from a fixed solar field size, coupled with a thermal energy storage mechanism has been designed to replace steam in one of the feed water heaters. The effect of this retrofit on the net efficiency of the coal plant has been examined. Also, a concept of two tank direct molten salt storage has been introduced for this hybrid plant. When thermal energy storage is removed, the improvement in the coal plant efficiency is in the range of 7-14 %. Calculations for the storage systems and the salt-water heat exchanger are also shown. The improvement in the net efficiency of the coal plant comes out to be in the range of 1-3% by using two tank direct thermal storage system.by Sonia GuptaM.Tech.M.Tech