# ass12 - ENGRD 221 ENGINEERING THERMODYNAMICS Problem Set 12...

This preview shows pages 1–2. Sign up to view the full content.

ENGRD 221: E NGINEERING T HERMODYNAMICS Problem Set 12 Due: April 24 th 2009, Upson Room 123 (4 Questions) Question 1 (MS 10.31) : The figure below shows a two-stage, ammonia vapor compression refrigeration system with two evaporators and a direct contact heat exchanger. Saturated vapor from evaporator 1 enters compressor 1 at 18 lbf/in. 2 and exits at 70 lbf/in. 2 Evaporator 2 operates at 70 lbf/in. 2 , with saturated vapor exiting at state 8. The condenser pressure is 200 lbf/in. 2 , and saturated liquid refrigerant exits the condenser. Each compressor stage has an isentropic efficiency of 80%. The refrigeration capacity of each evaporator is shown in the figure. Sketch the T-s diagram of the cycle and determine (a) the temperatures, in °F, of the refrigerant in each evaporator. (b) the power input to each compressor stage, in horsepower. (c) the overall coefficient of performance.

This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document
This is the end of the preview. Sign up to access the rest of the document.

{[ snackBarMessage ]}

### What students are saying

• As a current student on this bumpy collegiate pathway, I stumbled upon Course Hero, where I can find study resources for nearly all my courses, get online help from tutors 24/7, and even share my old projects, papers, and lecture notes with other students.

Kiran Temple University Fox School of Business ‘17, Course Hero Intern

• I cannot even describe how much Course Hero helped me this summer. It’s truly become something I can always rely on and help me. In the end, I was not only able to survive summer classes, but I was able to thrive thanks to Course Hero.

Dana University of Pennsylvania ‘17, Course Hero Intern

• The ability to access any university’s resources through Course Hero proved invaluable in my case. I was behind on Tulane coursework and actually used UCLA’s materials to help me move forward and get everything together on time.

Jill Tulane University ‘16, Course Hero Intern