Chapter 7

Info iconThis preview shows page 1. Sign up to view the full content.

View Full Document Right Arrow Icon
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: ines For a turbine under steady operation, the inlet state of the working fluid and the exhaust pressure are fixed. Therefore, the ideal process for an adiabatic turbine is an isentropic process between the inlet state and the exhaust pressure. The desired output of a turbine is the work produced, and the isentropic efficiency of a turbine is defined as the ratio of the actual work output of the turbine to the work output that would be achieved if the process between the inlet state and the exit pressure were isentropic: hT Actual turbine work Isentropic turbine work wa ws (7–60) Usually the changes in kinetic and potential energies associated with a fluid stream flowing through a turbine are small relative to the change in enthalpy and can be neglected. Then the work output of an adiabatic turbine simply becomes the change in enthalpy, and Eq. 7–60 becomes hT h1 h1 h2a h2s (7–61) where h2a and h2s are the enthalpy values at the exit state for actual and isentropic processes, respectively (Fig. 7...
View Full Document

This document was uploaded on 11/28/2012.

Ask a homework question - tutors are online