Introduction: How to Find the Work of an Isentropic Turbine.

Steam enters at turbine at an inlet temperature (T) 200 degrees C and pressure (P) of 0.06 bar and a mass flow rate (m) of 4kg/s. Water vapor exits the turbine at the outlet of a pressure (P2) of 0.00611 bar. The turbine is isentropic. Find the power (W) produced by the turbine.

Step 1: Draw a Picture of a Turbine.

A turbine can be modeled as trapezoid where the parallel sides are vertical and the short side is facing toward the right.

Step 2: Label

Label all given information with units on the inlets and outlets of the turbine. The inlet of the turbine is on the left side and the outlet of the turbine is on the right side.

Step 3: Create a Separate Table of All Given Data and Allow Room for New Data.

Create two tables labeled “Inlet” and “Outlet” and write down all the given data in the problem statement.

Step 4: Go to "Superheated Water"

Find the table where the pressure equals the inlet pressure. In that chart look down the ‘T’ column until you find the inlet temperature value. At that temperature, look to the right until you reach the ‘h’ and ‘s’ column. Write those numbers in your chart under "Inlet."

Step 5: Go to "Properties of Saturated Water (Liquid-Vapor): Temperature Table.

In the table, go to the “sg” column and find the value that is within ±0.02 of your inlet ‘s’ value . In that same row, go to the column that says “hg” and write down in our “Outlet” chart and label it as h2.

Step 6: Solve Using the Equation W=m*(h_1-h_2)

You have all the information you need to solve the power produced coming out of the turbine.

Step 7: Check Your Answer.

YYou should get the answer 1512 ±5kW.


seamster (author)2016-09-02

Thanks for sharing :)