A STUDY ON THE EFFECTS OF STEAM PRESSURE AND PINCH POINT TEMPERATURE IN ONE AND TWO PRESSURE LEVELS HRSG FOR A COMBINATION CYCLES PLANT

• Main Author: Kriscahyo, Sevian
• Format: Final Project
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/47151
• Institution: Institut Teknologi Bandung

In a combined power plant, gas turbine?s exhaust is further utilized for generating steam which then is expanded in a steam turbine for additional power output. The aim of this study is to explore the effect of steam pressure and pinch point temperature on heat absorption and steam power generation. In order to achieve the aim of the study, the first law of thermodynamics is implemented to a HRSG thermal model using Cycle Tempo 5.0, where the output data is collected and processed using Microsoft Excel. For thermal model simulations, pressure range of 7–70 bar and pinch point temperature range of 5–20oC are employed. The result of a one-pressure level HRSG shows that the highest heat absorption which is 241.5 MW at a combination of steam pressure and certain temperature pinch points, such as 7.0 bar of steam pressure and pinch point temperature of 20°C; whereas the maximum turbine output of 71.24 MW occurs when the steam pressure is 54.3 bar at pinch point temperature of 5 o C. For a two-pressure level HRSG with constant low steam pressure of 3.6 bar at pinch point temperature of 5 o C, there is an optimum heat absorption of 229.84 MW and steam turbine power generation of 76.55 MW which occurs at high steam pressure of 70.0 bar at pinch point temperature of 5 o C. The results of a one-pressure level HRSG show that there is an optimum pressure which produces the greatest steam turbine power at the smallest pinch point temperature. The greatest heat absorption is obtained at a combination of steam pressures and pinch point temperatures. The results of a two-pressure level HRSG with a constant low pressure of 3.6 bar at pinch point temperature of 5 o C show that there is the best of turbine power and heat absorption at the highest steam pressure and lowest pinch point temperature.