Diego A. Acosta

If you need a tester using libreoffice on windows 10, I will do it... How can I help?

I am interested... Can you revive bibus?

Aha! I think I found the problem with Exercise 6.46 from "Fundamentals of Thermodynamics" by Borgnakke and Sonntag: It is the thermdynamics package! When I tried V2 of Steam Tables it went wrong (an expander with a 116% efficiency is not right!) With V1 of steam tables the exercise is solved correctly. I am attaching it here for your consideration.

Hi Daniel, But of course! I will be very happy with that. The way I am learning is by solving problems from the literature and comparing my answers with the authors' answers. Many thanks, Diego

I have done another problem thinking that perhaps the original Exercise 6.46 from "Fundamentals of Thermodynamics" by Borgnakke and Sonntag wasn't correct. I am attaching it here in DWSIM and the problem comes from Cengel's 8ed Thermodynamics book: 5–48 Steam enters an adiabatic turbine at 10 MPa and 500°C and leaves at 10 kPa with a quality of 90 percent. Neglecting the changes in kinetic and potential energies, determine the mass flow rate required for a power output of 5 MW. Answer: 4.852 kg/s...

I have used an adjust block to get the 100 kW from the turbine by manipulating the adiabatic efficiency and was able to get the same answer as the COCO simulation but, the adiabatic efficiency turned out to be 116%... I am attaching the dwsim file for your review. Other than that the results coincide. EDIT: The isentropic efficiency with COCO yields 52.86%

I have used an adjust block to get the 100 kW from the turbine by manipulating the adiabatic efficiency and was able to get the same answer as the COCO simulation but, the adiabatic efficiency turned out to be 116%... I am attaching the dwsim file for your review. Other than that the results coincide.

Goodness sake... I was just toying with the efficiency Daniel... I will try that one, thanks!