Ch 5. Second Law of Thermodynamics Multimedia Engineering Thermodynamics Heat Engine The SecondLaw CarnotCycle Carnot HeatEngine CarnotRefrigerator
 Chapter 1. Basics 2. Pure Substances 3. First Law 4. Energy Analysis 5. Second Law 6. Entropy 7. Exergy Analysis 8. Gas Power Cyc 9. Brayton Cycle 10. Rankine Cycle Appendix Basic Math Units Thermo Tables Search eBooks Dynamics Statics Mechanics Fluids Thermodynamics Math Author(s): Meirong Huang Kurt Gramoll ©Kurt Gramoll

 THERMODYNAMICS - CASE STUDY Introduction A Power Plant In order to win a design contract for a power plant, a company is soliciting ideas from its three design teams. The power plant receives heat from a underground hot spring and rejects the waste heat to the surrounding air. The three teams are required to submit the schematic of their design and report the efficiency of the power plant. What is known: The temperature of water in the underground hot spring is 140 oC The temperature of the surrounding air is 30 oC The thermal efficiencies reported by the three teams are: Team A: 18.0% Team B: 26.6% Team C: 28.0% Question Based on the Carnot Principles, determine which design is possible. Approach Compare the thermal efficiency reported by the three teams with the thermal efficiency of a Carnot Heat Engine (will be introduced in next section) working between 140 oC and 30 oC, which is:       ηREV = 1 - (30 + 273)/(140 + 273) = 26.6%