Combined gas/steam turbine plants have been proposed for cogeneration of electricity and process steam for quite some time now. Examples include combined cycle-power plants coupled with absorption refrigeration, seawater desalination plants and district heating. Typical of combined-cycle plants is their dependance on the performance of the prime mover (gas turbine) powering the cycle, on the one hand, and the heat recovery steam generator's (HRSG's) operating parameters, on the other hand. Gas turbines are usually rated at certain environmental conditions which are, an ambient temperature of 15°C, a 60% relative humidity (RH), and sea-level conditions. However, the above conditions rarely prevail at all times in hot climate regions where temperatures in excess of 45°C and relative humidities of more than 90% are present simultaneously. Consequently, their actual power output and thermal efficiencies are much lower during hot and humid conditions than their rated design values. Nevertheless, changes made in the HRSG's operating parameters (i.e., pinch point, approach temperature, first and second stage pressures, and mass ratios) can greatly affect the HRSG performance and will eventually affect the overall combined plant performance. Analysis of such combined plants at various operating conditions is with no doubt a tedious and time-consuming job. It is therefore the purpose of this paper to introduce the development of a computer program to study the performance of the overall combined plant at various atmospheric and loading conditions. The program uses a fully interactive approach and should be most helpful in monitoring changes in the plant performance, if any of the operating parameters is varied.
|Publication status||Published - 1 Oct 1991|
ASJC Scopus subject areas
- Filtration and Separation