EVALUATION OF PARALLEL FEED WATER HEATING IN INTEGRATED SOLAR THERMAL POWER PLANT

Abstract

The integration of steam power plant to solar thermal energy is a research area based on modern day challenges of higher power production with lower emission. The steam power plant solar integration can be done in many ways detailed in this project. One such method is to replace feed water heaters of a regenerative steam power plant with solar heating system. This is the most recent scheme and requites least modification in existing plant. It is also very flexible integration scheme as the control systems provide methods to operate plant in solar integrated mode as well as base mode. The analysis is done based on two methods; analytical method and simulation method. The analysis is performed by formulating entire case and then analyzing it with data available with on ‘Engineering Equation Solver’ (EES) software. The concept of solar thermal energy storage to increase overall efficiency of integrated model is also introduced and analyzed. This model is then simulated in ‘System Analyzer Model’ (SAM) software to get the trend analysis results of the project. The ‘Integrated Solar Thermal Power Plant, Dadri’ is chosen as the base model of this work. The solar thermal integration at this plant is modeled on ‘Compact Linear Fresnel Reflector’ (CLFR) Technology. In this work the CLFR is replaced with ‘Heliostat Field Collector’ (HFC). This model is having higher solar thermal collection efficiency as well as more heat available to aid the steam cycle. The solar thermal storage addition had added system ability to operate with integrated mode for a longer duration. Talking to the environmental front, this type of integrating with optimum integration mode had proved better on emission front. The carbon dioxide and sulphur dioxide emissions are reduced in the integrated mode as obtained from the analysis results. The other pollutants are also assumed to be reduced in the same pattern. In economical terms, the project is also analyzed on coal saving front. The hourly coal saving in different integration modes is provided. This shows the economical benefits of the project. Carbon dioxide emission reduction is also a good step to save carbon tax as well. Thus the benefits of such schemes are worth noting and further research should also be continued on the technology for betterment of existing results.