ME 311 FALL 2007 CHAPTER 9 Gas Power Cycles
THERMODYNAMICS
S. Masutani
Chapter 8 focused on power systems in which the working fluid existed as either a liquid or a gas at different points in the cycle. The chief advantage of these vapor power sys
ME 311 FALL 2007 CHAPTER 3 (continued)
THERMODYNAMICS
S. Masutani
Thermodynamic Property Data, p-v-T Relationship for Gases Learn to use tables of thermodynamic properties. 1. Steam tables (power systems)/refrigerant tables 2. Gas tables propulsi
ME 311 FALL 2007 CHAPTER 8 (continued)
THERMODYNAMICS
S. Masutani
The ideal Rankine cycle consists of internally reversible processes. We determined earlier that
a b Q )int .rev. = TdS Qintrev. = TdS . a b
Or, in terms of a unit mass flowing th
ME 311 FALL 2007 UNIT SYSTEMS
THERMODYNAMICS
S. Masutani
The textbook employs two systems: SI and English engineering system This is rather tedious, but probably will continue for a good portion of your careers. Before examining the differences in
ME 311 FALL 2007 CHAPTER 2 (continued)
THERMODYNAMICS
S. Masutani
Reiterating The energy (E = U + KE + PE) of a closed system is altered by interactions between the system and its surroundings. These interactions are divided into work and heat tr
ME 311 FALL 2007 CHAPTER 3
THERMODYNAMICS
S. Masutani
The State Postulate & Properties of Simple Substances It is clear that, to perform an energy (thermodynamic) analysis of a system, we need information on the properties of the system and relati
ME 311 FALL 2007 CHAPTER 6 (continued)
THERMODYNAMICS
S. Masutani
Having derived relationships for changes in entropy of two idealized substances (ideal gases and incompressible substances), we next consider their application in processes or event
ME 311 FALL 2007 CHAPTER 6 (continued) Gibbs Equation
THERMODYNAMICS
S. Masutani
We have derived thermodynamic definitions of temperature and pressure (for a SCS):
1 s p s and T u v T v u
Since s = s(u,v), then
1 p s s ds = d
ME 311 FALL 2007
THERMODYNAMICS
S. Masutani
CHAPTER 8 VAPOR POWER CYCLES The fundamental task to be accomplished by the systems described in Chapters 8 and 9 is the conversion of chemical or nuclear energy (i.e., energy "stored" in molecular or nu
ME 311 FALL 2007 CHAPTER 6 (continued) Example (limiting efficiencies)
THERMODYNAMICS
S. Masutani
Combustion power system: TH = 2000 K; TC = 290 K Material limitations typical result in TH ~ 1000 K. Thus, for an ideal cycle, the limiting T 290 = 0
ME 311 FALL 2007 FINAL LECTURE CHAPTER 10
THERMODYNAMICS
S. Masutani
REFRIGERATION AND HEAT PUMPS The objective of refrigeration systems is to remove energy by means of heat transfer from an insulated space held at a temperature below ambient. Thi
ME 311 FALL 2007 CHAPTER 2
THERMODYNAMICS
S. Masutani
Focus for time being on closed systems. 1st Law: Conservation of Energy Energy: Can be stored (accumulated) Can be transformed Can be transferred across system boundaries For closed systems:
ME 311 FALL 2007
THERMODYNAMICS
S. Masutani
Specific Volume = v 1/ Volume occupied by a unit mass Textbook uses notation v to signify the volume occupied by a mole (kgmole, lbmole, gmole) of molecules; hence
v = MW v
Pressure Very familiar c
ME 311 FALL 2007
THERMODYNAMICS
S. Masutani
Lecture I: Introductory Concepts (Sections 1.1-1.3 in textbook) Thermodynamics as a discipline focuses on energy. Energy, in turn, typically is related to the ability to perform work. A conceptual fee
ME 311 FALL 2007 CHAPTER 5 The 2nd Law The direction of processes
THERMODYNAMICS
S. Masutani
The first law (COE) is applied to confirm that a postulated process or event does not violate the principle that energy cannot be created nor destroyed. A
Will be posted prior to each Quiz ECE331 Section 001 Instructor: Prof. B.J. Baliga Quiz 6:_April 15, 2005 with Solutions
Problem 1:_OpAmp Circuit (50 points) (a) State the "Summing Point Constraint" for an OpAmp circuit. (10 points) (b) Identify (by
ME 311 FALL 2007
THERMODYNAMICS
S. Masutani
Probability Measures-Basic Concepts Consider a container with three numbered balls: 1, 2, and 3
1 3
2
Perform an experiment: blindfolded, pull out a ball; have an assistant record its number; replace
ME 311 FALL 2007 CHAPTER 5 (continued)
THERMODYNAMICS
S. Masutani
To be able to apply the 2nd Law in analyses of systems we must be able to evaluate entropy as a function of state. 2 ways: 1. Determine the probabilities of energy microstates and a
ME 311 FALL 2007 CHAPTER 6
THERMODYNAMICS
S. Masutani
The preceding lectures attempted to provide insight on how entropy can be evaluated using quantumstatistical (microscopic) concepts. As mentioned previously, the difference in the entropy of tw
ME 311 FALL 2007 CHAPTER 8 (conclusion)
THERMODYNAMICS
S. Masutani
Example: Basic open Rankine cycle
& Qin
2
& Wp
boiler 3
pump turbine 1
& Wt
4
Working Fluid: H2O p1 = 1 bar, T1= 25C = 298K p2 = 40 bar T3 = saturation temperature at 40 bar
ME 311 FALL 2007 CHAPTER 9 (conclusion) GAS POWER SYSTEMS
THERMODYNAMICS
S. Masutani
Familiar examples: gas turbine power plants; automobile, truck, locomotive engines; ramjets and aircraft propulsion systems. Internal Combustion Engines: Refers