Calculating Work and Heat Transfer in Gas Mixture Compression

Click For Summary

Discussion Overview

The discussion centers around calculating work and heat transfer for the compression of a hydrocarbon gas mixture in a reversible, isothermal, steady-flow compressor. The problem involves determining these values per unit mass of the gas mixture, considering its composition and initial conditions.

Discussion Character

  • Homework-related
  • Mathematical reasoning

Main Points Raised

  • One participant presents the problem involving a gas mixture of methane, propane, and butane, specifying the initial and final pressures and temperatures.
  • Several participants emphasize the need for the original poster to show their attempt at a solution before receiving help.
  • A participant suggests using equations related to work and heat transfer, noting that since the process is isothermal, the temperatures remain constant and changes in kinetic and potential energy are negligible.
  • Another participant proposes calculating the work input by determining how pressure varies with volume along the compression path for a unit mass of the mixture.

Areas of Agreement / Disagreement

There is no consensus on the solution approach, as participants are focused on guiding the original poster to demonstrate their understanding before proceeding. The discussion remains unresolved regarding the specific calculations needed.

Contextual Notes

Participants have not provided specific assumptions or detailed mathematical steps, and the discussion lacks a clear resolution on how to approach the calculations.

Who May Find This Useful

Students or individuals interested in thermodynamics, particularly in the context of gas mixtures and compression processes, may find this discussion relevant.

stephenzztan
Messages
2
Reaction score
0
A mixture of hydrocarbon gases is composed of 60% methane, 25% propane, and 15%
butane by weight. This mixture is compressed from 100 kPa and 20ºC to 1000 kPa in a
reversible, isothermal, steady-flow compressor. Determine the work and heat transfer
for this compression per unit mass of the mixture.
 
Physics news on Phys.org
If you are asking for help obtaining a solution to this problem, you must show your attempt at a solution first.
 
CFDFEAGURU said:
If you are asking for help obtaining a solution to this problem, you must show your attempt at a solution first.

hi there... i just can't figure out where to start... perhaps... should be using few of these equations : -

W in = q out + (h2 - h1)
Win = Q out
since it's isothermal, T1 = T2, change of KE and PE will be negligible
steady flow , mass flow rate will be constant

i just.. blurred... i hope there's enlightment... i need to submit this on coming friday.

thank you
 
I would calculate Win here.

For that, you'd need to figure out how pressure varies with the volume of a unit mass -- say 1 kg -- along the path described.
 

Similar threads

  • · Replies 2 ·
Replies
2
Views
2K
Replies
1
Views
2K
Replies
9
Views
9K
  • · Replies 7 ·
Replies
7
Views
2K
  • · Replies 4 ·
Replies
4
Views
4K
  • · Replies 8 ·
Replies
8
Views
4K
Replies
1
Views
2K
  • · Replies 3 ·
Replies
3
Views
2K
  • · Replies 23 ·
Replies
23
Views
6K
Replies
21
Views
9K