Thursday, July 18, 2019

A combined heat and power (CHP) station generates electrical power and useful heat. The diagram shows the input and output for a CHP station.


Question 30
A combined heat and power (CHP) station generates electrical power and useful heat. The diagram shows the input and output for a CHP station.



What is the efficiency of the CHP station for producing useful power?
A 31%             B 38%             C 50%             D 81%





Reference: Past Exam Paper – November 2015 Paper 11 Q16





Solution:
Answer: D.

Useful power output = Useful heating power + Useful electrical power
Useful power output = 160 + 100 = 260 MW


Total power input = Useful heating power + Useful electrical power + Wasted power
Total power input = 160 + 100 + 60 = 320 MW


Efficiency = useful output power / total power input × 100%

Efficiency = (260 / 320) × 100 %
Efficiency = 81.25 % = 81 %
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2 comments:

  1. AnonymousJuly 20, 2019 at 2:40 AM

    Hello. Could you please solve May/June 2016 P4 Q2? Thank you.

    ReplyDelete
    Replies
    1. AdminJuly 20, 2019 at 11:58 PM

      go to
      http://physics-ref.blogspot.com/2019/07/gas-molecules-leak-from-container-in-b.html

      Delete

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