Question

Steam enters an adiabatic turbine at 7 MPa, 600°C, and 80 m/s and leaves at 50 kPa, 150°C, and 140 m/s. If the power output of the turbine is 6 MW, determine:
(a) the mass flow rate of the steam flowing through the turbine.
(b) the isentropic efficiency of the turbine.

Answer 1

Answer:

mass flow=6.84kg/s

efficiency=73.5%

Explanation:

Hi!

To solve this problem follow the steps below, the procedure is attached in an image

1. Draw the complete outline of the problem.

2.Through laboratory tests, thermodynamic tables were developed, these allow to know all the thermodynamic properties of a substance (entropy, enthalpy, pressure, specific volume, internal energy etc ..)  

through prior knowledge of two other properties such as pressure and temperature.  

use thermodynamic tables to determine the following thermodynamic properties:

a. enthalpy at the turbine inlet

b. entropy at the turbine entrance

c. ideal enthalpy at the turbine outlet

d. real enthalpy at the turbine outlet

3.  use the turbine efficiency equation and use the enthalpies found in step 2

4.

uses the first law of thermodynamics that states that the energy that enters a system is the same that must come out, in this way we find the mass flow