TEST_3_F95

# TEST_3_F95 - ME326:THERMODYNAMICS I Test3,Dec.1,1995...

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

ME 326: THERMODYNAMICS I Test 3, Dec. 1, 1995 1) (33%) An inventor  brings you a heat engine that she claims takes  thermal energy from a solar collector at 227°C at a rate of 300 kW, converts  200 kW to mechanical power  and  rejects the rest to a cooling pond  at 27°C. a) What is the thermal efficiency of this heat engine if it operates as  claimed? b) Does this heat engine violate the first law of thermodynamics? c) Does this heat engine violate the second  law of thermodynamics? (Provide  some mathematical justification for your answers.) SOLUTION: a)   η =W net /Q h =200/300=0.67 or 67% b)  Write First Law around  complete cycle:  W net =Q h -Q c   or Q c  = Q h  - W net  =300-200 = 100 kW; As long as rejected  rate of heat   transfer is 100 kW, the device obeys the First Law . c) Can 1) Check whether  efficiency of real device (0.67 from part a) is less

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.

## This note was uploaded on 04/20/2010 for the course M E 320 taught by Professor Deinert during the Spring '08 term at University of Texas.

### Page1 / 2

TEST_3_F95 - ME326:THERMODYNAMICS I Test3,Dec.1,1995...

This preview shows document pages 1 - 2. Sign up to view the full document.

View Full Document
Ask a homework question - tutors are online