HVAC · Practice-Exam-2 · Problem 73PDFSolution in PDF ↓
HVAC · Practice-Exam-2 · Problem 73
Problem & Solution
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Topic: Turbine / expander — Steam enters a turbine at a pressure of 1,000 PSIA and a temperature of 800 degrees, and exits at a pressure of 90 PSIA and a temperature of 400 degrees.
Method: What is the efficiency?
Key values: 1389 BTU per pound, 1.567 BTU per pound degrees Fahrenheit, 1,000 PSIA
Reference: table, we'll find that H1 is 1389 BTU per pound
✅ Answer: B
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Student questions asked in live office hours about this problem
OH 113: HVAC: Full Practice Exam #73
Q: And then the next one is from HVAC Practice Exam 73.
A: When I searched the reference sample for an equation for turbine efficiency, the one I found was on page 281, turbine, isentropic efficiency. This formula was based on the temperature and used TES. The isentropic exit temperature in the denominator.