Steam at 15 bar is throttled to 1 bar and a temperature of 150°C. Calculate the initial dryness fraction and the change of entropy. Sketch the process on a T-s diagram?
Answers
Steam at 15 bar is thrown into 1 bar with a temperature of 150 ° C and the first part of the drying and entropy change:
Steam in 15 bar is broken into one bar and a temperature of 150 o C.
Calculate the first fraction of dryness and the change of a particular entropy.
Draw the process in the T diagram and state the considerations made in the drawing process.
s (0.992; 1.202 kJ / kg K).
In the case of wet steam, actual entropy can be calculated with evaporation quality, x, and specific entropies of liquid and dry steam = s s x + (1 - x) s l.
there. s wet = entropy of steam steam (J / kg K) s s = entropy of “dry” steam (J / kg K) s s l = entropy of solid liquid (J / kg K) Direct Volume of Liquid Steam.
Similarly, a certain amount of water is not a full liquid (x = 0).
As it depends on the initial and final state of the system, the total amount of entropy cannot be determined.
You need to consider the difference between the initial and the final condition in order to determine the change in entropy.
Procedure on T-s drawing:
T-s drawing is a useful and common tool, especially because it helps to visualize heat transfer during the process.
The isentropic process is shown as a straight line in the T-s diagram, while the isothermal process is a horizontal line.
In the ideal case, compression is a pump, compressor compression, and turbine expansion are isentropic processes.