ES 202 Fluid and Thermal Systems Lecture 21: Isentropic Efficiencies (1/30/2003)

Slides:



Advertisements
Similar presentations
Second Law Analysis of Open Systems Isentropic Device Efficiency
Advertisements

Entropy balance for Open Systems
Advanced Thermodynamics Note 6 Applications of Thermodynamics to Flow Processes Lecturer: 郭修伯.
Chapter 7 Entropy (Continue).
ES 202 Fluid and Thermal Systems Lecture 15: Properties in Two-Phase Region (1/16/2003)
Department of Mechanical Engineering ME 322 – Mechanical Engineering Thermodynamics Lecture 19 Calculation of Entropy Changes.
Entropy Cengel & Boles, Chapter 6 ME 152.
Entropy Change Property diagrams (T-s and h-s diagrams) –From the definition of the entropy, it is known that  Q=TdS during a reversible process. –Hence.
Lec 18: Isentropic processes, TdS relations, entropy changes
Consequences from the Existence of Entropy Relationship between the internal energy U=U(T,V) and the equation of state P=P(T,V) Remember: with this notation.
7.7 The Tds Relations.
ES 202 Fluid and Thermal Systems Lecture 2 (12/03/2002)
ES 202 Fluid and Thermal Systems Lecture 18: Making the Connection (1/23/2003)
ES 202 Fluid and Thermal Systems Lecture 5: Buoyancy & ES 201 Review (12/10/2002)
Entropy Thermodynamics Professor Lee Carkner Lecture 13.
ES 202 Fluid and Thermal Systems Lecture 6: ES 201 Review & Steady State Devices (12/12/2002)
ES 202 Fluid & Thermal Systems
Chapter 7 Continued Entropy: A Measure of Disorder Study Guide in PowerPoint to accompany Thermodynamics: An Engineering Approach, 5th edition.
ES 202 Fluid and Thermal Systems Lecture 23: Power Cycles (2/4/2003)
ES 202 Fluid and Thermal Systems Lecture 22: Isentropic Efficiencies & Simple Power Cycles (2/3/2003)
ES 202 Fluid and Thermal Systems Lecture 7: Mechanical Energy Balance (12/16/2002)
ES 202 Fluid and Thermal Systems Lecture 17: More on properties and phases (1/21/2003)
ES 202 Fluid and Thermal Systems Lecture 12: Pipe Flow Overview (1/9/2003)
Instructors Visual Aids Heat, Work and Energy. A First Course in Thermodynamics © 2002, F. A. Kulacki Chapter 6 Module 1 Slide 1 The T-dS Equations ΔS.
ES 202 Fluid and Thermal Systems Lecture 20: Isentropic Processes (1/28/2003)
ES 202 Fluid and Thermal Systems Lecture 24: Power Cycles (II) (2/6/2003)
ES 202 Fluid and Thermal Systems Lecture 16: Property Tables (1/20/2003)
EGR 334 Thermodynamics Chapter 6: Sections 11-13
Power Generation Cycles Vapor Power Generation The Rankine Cycle
Department of Mechanical Engineering ME 322 – Mechanical Engineering Thermodynamics Lecture 27 Gas Power Generation The Brayton Cycle.
Evaluating entropy changes
Thermodynamics I Chapter 6 Entropy Mohsin Mohd Sies Fakulti Kejuruteraan Mekanikal, Universiti Teknologi Malaysia.
PTT 201/4 THERMODYNAMIC SEM 1 (2013/2014) CHAPTER 7: Entropy.
Chapter 7 ENTROPY Mehmet Kanoglu
PTT 201/4 THERMODYNAMIC SEM 1 (2012/2013). Objectives Apply the second law of thermodynamics to processes. Define a new property called entropy to quantify.
Department of Mechanical Engineering ME 322 – Mechanical Engineering Thermodynamics Review For Exam 1.
ES 202 Fluid and Thermal Systems Lecture 14: Phase Change (1/14/2003)
Introduction Lecture Prepared by Prof. M. G. Wasel.
ME 200 L31: Review for Examination 3 ME 200 L31: Review for Examination 3 Thu 4/10/14 Examination 3 (L22 – L30) 6:30 – 7:30 PM WTHR 200, CL50 224, PHY.
Lecture slides by Mehmet Kanoglu
Entropy Chapter The important point is that since entropy is a property, the change in the entropy of a substance in going from one.
Review for Exam 2.
ERT 206 THERMODYNAMICS WAN KHAIRUNNISA WAN RAMLI
Last Time Where did all these equations come from?
Entropy Change Property diagrams (T-s and h-s diagrams) from the definition of the entropy, it is known that Q=TdS during a reversible.
Chapter 4: Applications of the First Law Different types of work: Configuration work: (reversible process) Dissipative work: (irreversible process) Adiabatic.
ChemE 260 Entropy Balances On Open and Closed Systems
ES 202 Fluid & Thermal Systems
Entropy Property Relationships Chapter 7b. The T-ds relations Consider an internally reversible process occurring in a closed system.
1 Property Relationships Chapter 6. 2 Apply the differential form of the first law for a closed stationary system for an internally reversible process.
Chapter 7 ENTROPY Dr. Kagan ERYURUK
Thermodynamics I Inter - Bayamon Lecture 7 Thermodynamics I MECN 4201 Professor: Dr. Omar E. Meza Castillo
6. ENTROPY. Objectives Apply the second law of thermodynamics to processes. Define a new property called entropy to quantify the second-law effects. Establish.
kr 1 Lecture Notes on Thermodynamics 2008 Chapter 7 Entropy Prof. Man Y. Kim, Autumn 2008, ⓒ Aerospace.
CHAPTER 6 Entropy. Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. The Clausius Inequality: This inequality.
The Second Law of Thermodynamics Entropy and Work Chapter 7c.
Unit Eight Quiz Solutions and Unit Nine Goals Mechanical Engineering 370 Thermodynamics Larry Caretto April 1, 2003.
Thermodynamics of Ideal Processes P M V Subbarao Professor Mechanical Engineering Department Entropy View of Theoretical Processes …..
ChemE 260 Entropy Generation Fundamental Property Relationships May 6, 2005 Dr. William Baratuci Senior Lecturer Chemical Engineering Department University.
Thermodynamics I. Examples  2.25  2.74  2.89 Wrap-up  Heat – work equivalent  Chapter 2 Equations  One-Minute Paper  Test 1: 1/27 Chapter 2 Text.
Reversibility Thermodynamics Professor Lee Carkner Lecture 14.
The Polytropic Process – Ideal Gas
Chapter 7 Entropy: A Measure of Disorder
Thermodynamics: An Engineering Approach Yunus A. Cengel, Michael A
Fundamentals of Thermal-Fluid Sciences
Review for Exam 2.
CHAPTER 6 Entropy.
Chapter 6: Entropy First law: Energy conservation concept.
Presentation transcript:

ES 202 Fluid and Thermal Systems Lecture 21: Isentropic Efficiencies (1/30/2003)

Lecture 21ES 202 Fluid & Thermal Systems2 Assignments Homework: –7-87, 7-90 in Cengel & Turner –Find rate of S gen in 7-63 (Monday) –Find  S for 7-35 (no modification on Tuesday) Reading assignment –8-5 to 8-7, 8-10, 8-11 in Cengel & Turner –ES 201 notes

Lecture 21ES 202 Fluid & Thermal Systems3 Announcements Problem session this evening at 7 pm Short quiz next Monday on Week 7 materials

Lecture 21ES 202 Fluid & Thermal Systems4 Road Map of Lecture 21 Overview of what you have already learned –property changes –general substances versus models –constant versus variable specific heats (solution methods) Finish up example on adiabatic versus non-adiabatic turbine More examples –reinforce what was taught –introduce the limit of best performance –notion of isentropic efficiency Representation of isentropic and non-isentropic processes on T-s diagram

Lecture 21ES 202 Fluid & Thermal Systems5 A Check List for You Property changes: –internal energy, enthalpy, entropy –general substances (State Principle) versus models general substance: State Principle (exact differential) definition of specific heats c p, c v Gibbs equation (two different forms) models: ideal gas, incompressible substance (resulting simplifications) constant versus variable specific heats –different solution methods: constant specific heats (analytical solutions) variable specific heats: –direct integration (the hard way) –use property table ( u, h, s 0, P r, v r ) – the easier way –“average” specific heats (may require iterations if temperatures are unknown) Special case of isentropic process

Lecture 21ES 202 Fluid & Thermal Systems6 Continue example on adiabatic versus non-adiabatic turbine

Lecture 21ES 202 Fluid & Thermal Systems7 Example on Entropy Generation

Lecture 21ES 202 Fluid & Thermal Systems8 Isentropic Efficiency Central theme: the reversible, adiabatic (i.e. isentropic) process sets the limit of best performance of any system It also sets the reference for the definition of efficiency of compressors and turbines For compressors and pumps, work is done on the system: For turbines, work is done by the system:

Lecture 21ES 202 Fluid & Thermal Systems9 Representation on T-s Diagram TurbineCompressor work out 12 work in 12 T s 1 2s 2 constant pressure lines T s 2s 1 2 constant pressure lines