Friday, April 14, 2006

HW #6 - P #4 - Effect of Source and Sink Temperatures on HE Efficiency - 8 pts

A heat engine operates between a source at TH and a sink at TC. Heat is supplied to the heat engine at a steady rate of 1200 kJ/min. Study the effects of TH and TC on the maximum power produced and the maximum cycle efficiency. For TC = 25oC, let TH vary from 300oC to 1000oC. Create plots of Wcycle and ηth as functions of TH. For TH = 550oC, let TC vary from 0oC to 50oC. Create plots of Wcycle and ηth as functions of TC. Discuss the results.

6 comments:

Anonymous said...

Dr. B said the W cycle in this problem is acutally W(doc) cycle, or power. Hope this will help everybody.

"It is difficult to put the dot over the Wcycle in html. I want you to plot the power, Wcycle, in kJ/min."

Dr. B said...

Kaifu 6:54
That is correct plot W in kJ/min.

Anonymous said...

I want to make sure I understand what the problem is asking for. Are we to make 4 separate plots Wcycle vs T(h); n(th) vs T(h); Wcycle vs T(c); and n(th) vs T(c)? Or did I read it wrong?

Dr. B said...

Carina 7:53 PM
Yes, make 4 separate plots. You read it correctly.

Anonymous said...

i am not sure if i have this right but should three of the plots be linear and only one is curved... that doesn't seem right to me

Dr. B said...

Anon 10:16 PM
Max Efficiency and Power vs Tc, are both linear. Neither is linear when plotted against TH.