Topics to be covered. Fundamental Concepts & Definitions: Thermodynamics; definition and scope. Microscopic

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1 time Class No Text/ Reference page Topics to be covered Fundamental Concepts & Definitions: Thermodynamics; definition and scope. Microscopic 1 and Macroscopic approaches. Engineering Thermodynamics Definition,, System (closed system) and Control Volume (open system);. Thermodynamic properties-definition and units, 2 Module 1 intensive and extensive properties. Thermodynamic state, state point, state diagram, path and process, quasi-static process, cyclic and non-cyclic 3 processes. Thermodynamic equilibrium; definition, mechanical equilibrium; Diathermic wall, thermal equilibrium, chemical equilibrium Zeroth law of thermodynamics, Temperature; concepts 4 Scales, measurement. Internal fixed points, 5 Numerical problems 6 Numerical problems Work & Heat: Mechanics, definition of work and its 7 limitations. Thermodynamic definition of work; Examples, sign convention. Displacement work; at part 8 of a system boundary, at whole of a system boundary, expressions for displacement work in various processes 9 through p-v diagrams 10 Shaft work; Electrical work. Other types of work 11 T 1 Page.No Heat; definition, units and sign convention, what heat is not, Numerical problems 12 Numerical Problems Module 2 T 1 Page.No R 1 Page.No T 1 Page.No. 63 R 1 Page.No T 1 Page.No. 63 Numerical problems 19 T 1 Page.No. 63 Numerical problems 20 T 1 Page.No R 1 Page.No First Law of Thermodynamics: Joule s experiments, equivalence of heat and work. Statement of the First law of thermodynamics, extension of the First law to non -cyclic processes energy, energy as a property, modes of energy, pure substance; definition, two-property rule, Specific heat at constant volume, enthalpy, specific heat at constant pressure. Extension of steady state-steady flow energy equation,numerical problems Important applications, analysis of unsteady processes such as filling and evacuation of vessels with and without heat transfer. Second Law of Thermodynamics: Devices converting heat to work; (a) in a thermodynamic cycle, (b) in a mechanical cycle. Thermal reservoir. Direct heat % of syllabus covered Chapter wise Cumulative 1

2 21 engine; Schematic representation and efficiency. Devices converting work to heat in a thermodynamic cycle; reversed heat engine, schematic representation T 1 Page.No T 1 Page.No Coefficients of performance. Kelvin -Planck statement of the Second law of Thermodynamic; PMM I and PMM1I. Clasiu's statement.of Second law of Thermodynamic; Equivalence of the two statements; Reversible and irreversible processes Factors that make a process.irreversible, reversible heat engines, Carnot cycle, Carnot principles, Thermodynamic temperature scale Numerical problems Numerical problems 27 Module 3 Reversibility: Definitions of a reversible process, reversible heat engine, importance and superiority of a reversible heat engine and irreversible processes;. 28 factors that make a process irreversible, reversible heat engines Unresisted expansion, remarks on Carnot s 29 engine, internal and external reversibility, Definition of the thermodynamic temperature scale 30 Numerical problems Entropy: Clasius inequality; statement, proof, 31 application to a reversible cycle T 1 Page.No Q 32 R /T as independent of the path. Entropy; definition, a R 1 Page.No property, principle of increase of entropy Entropy as a quantitative test for irreversibility, 33 calculation of entropy using Tds relations Availability, Irreversibility and General Thermodynamic relations. Introduction, Availability (Exergy), Unavailable energy (anergy), 34 Relation between increase in unavailable energy Module 4 and increase in entropy. Maximum work, maximum useful work for a system and control volume, 35 T 1 Page.No irreversibility, second law efficiency (effectiveness). heats.gibbs and Helmholtz

3 T 1 Page.No functions, Maxwell relations, Clapeyron equation, Joule Thomson coefficient, general relations for Numerical problems change in entropy, enthalpy, internal energy and specific Numerical problems Pure substances: P-T and P-V diagrams, triple point and critical points Sub- cooled liquid, saturated liquid, mixture of saturated liquid and vapor, saturated vapor and superheated vapour states of a pure substance with water as example 39 R 1 Page.No Enthalpy of change of phase (Latent heat). Dryness factor (quality), T-S and h-s diagrams, representation of various processes on these diagrams Steam tables and its use. Throttling calorimeter, 40 separating and throttling calorimeter. 41 T 1 Page.No Numerical problems 42 Numerical problems Ideal gas mixture : Ideal gas mixture; Dalton's laws of 43 partial pressures Amagat's law of additive volumes, evaluation of Module 5 T 1 Page.No R 1 Page.No properties internal energy and enthalpy as functions of temperature only, universal and particular gas constants, specific heats, perfect and semi-perfect gases. 46 Analysis of various processes.. 47 T 1 Page.No Numerical problems T 1 Page.No R 1 Page.No T 1 Page.No Real gases Introduction, Air water mixture and related properties, Van der Waal's Equation of state, Van der Waal's constants in terms of critical properties. Redlich and Kwong equation of state Beattie Bridgeman equation. Law of corresponding states, compressibility factor. compressibility chart. Difference between Ideal and real gases.law of corresponding states, compressibility factor; compressibility chart. Numerical problems

4 TEXTBOOKS: 1. Basic and Applied Thermodynamics, P.K.Nag, 2 nd Ed., Tata McGrawHill Pub Basic Engineering Thermodynamics, Dr. A.Venkatesh, Universities Press, 2008 REFERENCE BOOKS: 1. Thermodynamics, An Engineering Approach, Yunus A.Cenegal and Michael A.Boles, Tata McGraw Hill publications, Fundamentals of Classical Thermodynamics, G.J.Van Wylen and R.E.Sonntag, Wiley Eastern. 3. Engineering Thermodynamics, J.B.Jones and G.A.Hawkins, John Wiley and Sons. 4. An Introduction to Thermodynamcis, Y.V.C.Rao, Wiley Eastern, 1993, Question Bank: Unit I FUNDAMENTAL CONCEPTS & DEFINITIONS:- 1. What is the difference between the classical and the statistical approaches to thermodynamics? 2. What is the difference between the macroscopic and microscopic forms of energy? 3. Why does a bicyclist pick up speed on a downhill road even when he is not pedaling? Does this violate the conservation of energy principle? 4. An office worker claims that a cup of cold coffee on his table warmed up to 80 C by picking up energy from the Surrounding air, which is at 25 C.? Is there any truth to his claim? Does this process violate any thermodynamic laws? 5. What is the difference between pound-mass and pound-force? 6. A can of soft drink at room temperature is put into the refrigerator so that it will cool. Would you model the can of soft drink as a closed system or as an open system? Explain. 7. What is the difference between intensive and extensive properties? 4

5 8. For a system to be in thermodynamic equilibrium, do the temperature and the pressure have to be the same everywhere? 9. What is a quasi-equilibrium process? What is its importance in engineering? 10. Define the isothermal, isobaric, and isochoric processes. 11. What is the zeroth law of thermodynamics? 12. What are the ordinary and absolute temperature scales in the SI and the English system? 13. Consider an alcohol and a mercury thermometer that read exactly 0 C at the ice point and 100 C at the steam point. The distance between the two points is divided into 100 equal parts in both thermometers. Do you think these thermometers will give exactly the same reading at a temperature of, say, 60 C? Explain. 14. A 1m 3 tank is filled with a gas at room temperature 20 C and pressure 100 Kpa. How much mass is there if the gas is a) Air b) Neon, or c) Propane? 15. A cylinder has a thick piston initially held by a pin as shown in fig below. The cylinder contains carbon dioxide at 200 Kpa and ambient temperature of 290 k. the metal piston has a density of 8000 Kg/m3 and the atmospheric pressure is 101 Kpa. The pin is now removed, allowing the piston to move and after a while the gas returns to ambient temperature. Is the piston against the stops? 16. Two tanks are connected as shown in fig, both containing water. Tank A is at 200 Kpa,ν=1m3 and tank B contains 3.5 Kg at 0.5 Mp, 4000C. The valve is now opened and the two come to a uniform state. Find the specific volume. Unit II WORK & HEAT:- 1. In what forms can energy cross the boundaries of a closed system? 2. When is the energy crossing the boundaries of a closed system heat and when is it work? 3. A room is heated by an iron that is left plugged in. Is this a heat or work interaction? Take the entire room, including the iron, as the system. 4. What are point and path functions? Give some examples. 5. The engine of a 1500-kg automobile has a power rating of 75 kw. Determine the time required to accelerate this car from rest to a speed of 100 km/h at full power on a level road. Is your answer realistic? 6. A ski lift has a one-way length of 1 km and a vertical rise of 200 m. The chairs are spaced 20 m apart, and each chair can seat three people. The lift is operating at a steady speed of 10 km/h. Neglecting friction and air drag and assuming that the average mass of each loaded chair is 250 kg, determine the power required to operate this ski lift. Also estimate the power required to accelerate this ski lift in 5 s to its operating speed when it is first turned on. 7. Determine the power required for a 2000-kg car to climb a 100-m-long uphill road with a slope of 30 (from horizontal) in 10 s (a) at a constant velocity, (b) from rest to a final velocity of 30 m/s, and (c) from 35 m/s to a finalvelocity of 5 m/s. Disregard friction, air drag, and rolling resistance. Answers: (a) 98.1 kw, (b) 188 kw, (c) kw Unit III FIRST LAW OF THERMODYNAMICS:- 1. For a cycle, is the net work necessarily zero? For what kind of systems will this be the case? 5

6 2. On a hot summer day, a student turns his fan on when he leaves his room in the morning. When he returns in the evening, will the room be warmer or cooler than the neighboring rooms? Why? Assume all the doors and windows are kept closed. 3. What are the different mechanisms for transferring energy to or from a control volume? 4. Water is being heated in a closed pan on top of a range while being stirred by a paddle wheel. During the process, 30 kj of heat is transferred to the water, and 5 kj of heat is lost to the surrounding air. The paddlewheel work amounts to 500 N m. Determine the final energy of the system if its initial energy is 10 kj. Answer: 35.5 kj 5. Water is being heated in a closed pan on top of a range while being stirred by a paddle wheel. During the process, 30 kj of heat is transferred to the water, and 5 kj of heat is lost to the surrounding air. The paddlewheel work amounts to 500 N m. Determine the final energy of the system if its initial energy is 10 kj. Answer: 35.5 kj 6. Consider a room that is initially at the outdoor temperature of 20 C. The room contains a 100-W light bulb, a 110-W TV set, a 200-W refrigerator, and a 1000-W iron. Assuming no heat transfer through the walls, determine the rate of increase of the energy content of the room when all of these electric devices are on. 7. Air enters a nozzle steadily at 2.21 kg/m3 and 40 m/s and leaves at kg/m3 and 180 m/s. If the inlet area of then nozzle is 90 cm2, determine (a) the mass flow rate through the nozzle, and (b) the exit area of the nozzle. Answers: (a) kg/s, (b) 58 cm2 8. A hair dryer is basically a duct of constant diameter in which a few layers of electric resistors are placed. A small fan pulls the air in and forces it through the resistors where it is heated. If the density of air is 1.20 kg/m3 at the inlet and 1.05 kg/m3 at the exit, determine the percent increase in the velocity of air as it flows through the dryer 9. Air enters an adiabatic nozzle steadily at 300 kpa, 200 C, and 30 m/s and leaves at 100 kpa and 180 m/s. The inlet area of the nozzle is 80 cm2. Determine (a) the mass flow rate through the nozzle, (b) the exit temperature of the air, and (c) the exit area of the nozzle. Answers: (a) kg/s, (b) C, (c) 38.7 cm2 Unit IV SECOND LAW OF THERMODYNAMICS:- 1. An experimentalist claims to have raised the temperature of a small amount of water to 150 C by transferring heat from high-pressure steam at 120 C. Is this a reasonable claim? Why? Assume no refrigerator or heat pump is used in the process. 2. What is a thermal energy reservoir? Give some examples. 6

7 3. Consider the process of baking potatoes in a conventional oven. Can the hot air in the oven be treated as a thermal energy reservoir? Explain. 4. What is the Kelvin Planck expression of the second law of thermodynamics? 5. Does a heat engine that has a thermal efficiency of 100 percent necessarily violate (a) the first law and (b) the second law of thermodynamics? Explain. 6. What is the difference between a refrigerator and a heat pump? 7. What is the difference between a refrigerator and an air conditioner? 8. In a refrigerator, heat is transferred from a lower temperature medium (the refrigerated space) to a higher temperature one (the kitchen air). Is this a violation of the second law of thermodynamics? Explain. 9. A heat pump is a device that absorbs energy from the cold outdoor air and transfers it to the warmer indoors. Is this a violation of the second law of thermodynamics? Explain. 10. Define the coefficient of performance of a refrigerator in words. Can it be greater than unity? 11. Define the coefficient of performance of a heat pump in words. Can it be greater than unity? 12. In a steam power plant 1 MW is added at 700 C in the boiler, 0.58 MW is taken at out at 40 C in the condenser, and the pump work is 0.02 MW. Find the plant thermal efficiency. Assuming the same pump work and heat transfer to the boiler is given, how much turbine power could be produced if the plant were running in a Carnot cycle? 13. We wish to produce refrigeration at 300C. A reservoir, shown in fig is available at 200 0C and the ambient temperature is 30 0C. This, work can be done by a cyclic heat engine operating between the 200 0C reservoir and the ambient. This work is used to drive the refrigerator. Determine the ratio of heat transferred from 200 0C reservoir to the heat transferred from the 300C reservoir, assuming all process are reversible. Unit V ENTROPY:- 1. Does the temperature in the Clausius inequality relation have to be absolute temperature? Why? 2. Does the cyclic integral of heat have to be zero (i.e., does a system have to reject as much heat as it receives to complete a cycle)? Explain. 3. Does the cyclic integral of work have to be zero (i.e., does a system have to produce as much work as it consumes to complete a cycle)? Explain. 4. A system undergoes a process between two fixed states first in a reversible manner and then in an irreversible manner. For which case is the entropy change greater? Why? 5. Is an isothermal process necessarily internally reversible? Explain your answer with an example. 6. The entropy of a hot baked potato decreases as it cools. Is this a violation of the increase of entropy principle? Explain. 7. The radiator of a steam heating system has a volume of 20 L and is filled with superheated water vapor at 200 kpa and 150 C. At this moment both the inlet and the exit valves to the radiator are closed. After a while the temperature of the steam drops to 40 C as a result of heat transfer to the room air. Determine the entropy change of the steam during this process. Answer: _0.132 kj/k 8. A well-insulated rigid tank contains 2 kg of a saturated liquid vapor mixture of water at 100 kpa. Initially, three-quarters of the mass is in the liquid phase. An electric resistance heater placed in the tank is now 7

turned on and kept on until all the liquid in the tank is vaporized. Determine the entropy change of the steam during this process. Answer: 8.10 kj/k 9. An insulated piston cylinder device contains 0.

Determine (a) the final temperature in the cylinder and (b) the work done by the refrigerant. Unit VI PURE SUBSTANCES:- 1. Define latent heat of ice. 2. What is pure substance? 3.

8 turned on and kept on until all the liquid in the tank is vaporized. Determine the entropy change of the steam during this process. Answer: 8.10 kj/k 9. An insulated piston cylinder device contains 0.05 m3 of saturated refrigerant-134a vapor at 0.8-MPa pressure. The refrigerant is now allowed to expand in a reversible manner until the pressure drops to 0.4 MPa. Determine (a) the final temperature in the cylinder and (b) the work done by the refrigerant. Unit VI PURE SUBSTANCES:- 1. Define latent heat of ice. 2. What is pure substance? 3. What is saturation temperature and saturation pressure? 4. Define latent Heat of vaporization. 5. Define the terms 'Boiling point' and 'Melting point. 6. What is meant by super heated steam? and indicate its use. 7. Define: sensible heat of water. 8. Define the term "Super heat enthalpy". 9. What are wet and dry steam? 10. State phase rule of pure substances. 11. Define dryness fraction of steam (or) what is quality of steam? 12. Explain the terms: Degree of super heat, Degree of sub cooling. Degree of super heat: 13. Define triple point and critical point for pure substance. 14. A certain quantity of gas is head at constant pressure from 35 0 to 185 c. Estimate the amount of heat transferred, ideal work done, change in internal energy, when the initial volume of the gas is 0.6 m kg of gas at a pressure of 1.5bar. Occupies a volume of 2.5 m3. If this gas compresses isothermally to 1/3 times the initial volume. Find initial. Final temperature, work done, heat transfer. 16. A piston cylinder device contains 0.1 m3 of liquid water and 0.9 m3 of water vapor in equilibrium at 800 kpa. Heat is transferred at constant pressure until the temperature reaches 350 C. (a) What is the initial temperature of the water? (b) Determine the total mass of the water. (c) Calculate the final volume. 8

(d) Show the process on a P-v diagram with respect to saturation lines. 17. A piston cylinder device initially contains 50 L of liquid water at 40 C and 200 kpa.

9 (d) Show the process on a P-v diagram with respect to saturation lines. 17. A piston cylinder device initially contains 50 L of liquid water at 40 C and 200 kpa. Heat is transferred to the water at constant pressure until the entire liquid is vaporized. (a) What is the mass of the water? (b) What is the final temperature? (c) Determine the total enthalpy change. (d) Show the process on a T-v diagram with respect to saturation lines. Answers: (a) kg, (b) C, (c) 125,943 Kj 18. Determine the specific volume of superheated water vapor at 10 MPa and 400 C, using (a) The ideal-gas equation, (b) The generalized compressibility chart, and (c) the steam tables. Also determine the error involved in the first two cases Answers: (a) m3/kg, 17.6 percent; (b) m3/kg, 1.2 percent; (c) m3/kg Unit VII THERMODYNAMIC RELATIONS 1. Can the variation of specific heat cp with pressure at a given temperature be determined from a knowledge of Pv- T data alone? 2. Show that the enthalpy of an ideal gas is a function of temperature only and that for an incompressible substance it also depends on pressure. 3. Derive an expression for the specific-heat difference cp _ cv for (a) an ideal gas, (b) a van der Waals gas, and (c) an incompressible substance. 4. Estimate the specific-heat difference cp - cv for liquid water at 15 MPa and 80 C. Answer: 0.32 kj/kg K 5. Estimate the specific-heat difference cp - cv for liquid water at 1000 psia and 150 F. Answer: Btu/lbm R 6. Derive a relation for the Joule-Thomson coefficient and the inversion temperature for a gas whose equation of state is (P- a/v2) v = RT. 7. Steam is throttled from 4.5 MPa and 300 C to 2.5 MPa. Estimate the temperature change of the steam during this process and the average Joule-Thomson coefficient. Answers: _26.3 C, 13.1 C/MPa 8. A rigid tank contains 1.2 m3 of argon at _100 C and 1 MPa. Heat is now transferred to argon until the temperature in the tank rises to 0 C. Using the generalized charts, determine (a) the mass of the argon in the tank, (b) the final pressure, and (c) the heat transfer. Answers: (a) 35.1 kg, (b) 1531 kpa, (c) 1251 kj 9

10 Unit VIII IDEAL GAS MIXTURE:- 1. What is the difference between the component pressure and the partial pressure? When are these two equivalent? 2. What is the difference between the component volume and the partial volume? When are these two equivalent? 3. In a gas mixture, which component will have the higher partial pressure the one with the higher mole number or the one with the larger molar mass? 4. Consider a rigid tank that contains a mixture of two ideal gases. A valve is opened and some gas escapes. As a result, the pressure in the tank drops. Will the partial pressure of each component change? How about the pressure fraction of each component? 5. Consider a rigid tank that contains a mixture of two ideal gases. The gas mixture is heated, and the pressure and temperature in the tank rise. Will the partial pressure of each component change? How about the pressure fraction of each component? 6. Is this statement correct? The volume of an ideal gas mixture is equal to the sum of the volumes of each individual gas in the mixture. If not, how would you correct it? 7. Is this statement correct? The temperature of an ideal-gas mixture is equal to the sum of the temperatures of each individual gas in the mixture. If not, how would you correct it? 8. Is a mixture of ideal gases also an ideal gas? Givean example. 9. Express Dalton s law of additive pressures. Does this law hold exactly for ideal-gas mixtures? How about no ideal gas mixtures? 10. A rigid tank that contains 1 kg of N2 at 25 C and 300 kpa is connected to another rigid tank that contains 3 kg of O2 at 25 C and 500 kpa. The valve connecting the two tanks is opened, and the two gases are allowed to mix. If the final mixture temperature is 25 C, determine the volume of each tank and the final mixture pressure. Answers: m3, m3, 422 kpa 11. An insulated tank that contains 1 kg of O2 at 15 C and 300 kpa is connected to a 2-m3 uninsulated tank that contains N2 at 50 C and 500 kpa. The valve connecting the two tanks is opened, and the two gases form a homogeneous mixture at 25 C. Determine (a) the final pressure in the tank, (b) the heat transfer, and (c) the entropy generated during this process. Assume T0 =25 C. Answers: (a) kpa, (b) kj, (c) kj/k 10

11 12. A 0.9-m3 rigid tank is divided into two equal compartments by a partition. One compartment contains Ne at 20 C and 100 kpa, and the other compartment contains Ar at 50 C and 200 kpa. Now the partition is removed, and the two gases are allowed to mix. Heat is lost to the surrounding air during this process in the amount of 15 kj. Determine (a) the final mixture temperature and (b) the final mixture pressure. Answers: (a) 16.2 C, (b) kpa 11

UBMCC11 - THERMODYNAMICS. B.E (Marine Engineering) B 16 BASIC CONCEPTS AND FIRST LAW PART- A

UBMCC11 - THERMODYNAMICS. B.E (Marine Engineering) B 16 BASIC CONCEPTS AND FIRST LAW PART- A UBMCC11 - THERMODYNAMICS B.E (Marine Engineering) B 16 UNIT I BASIC CONCEPTS AND FIRST LAW PART- A 1. What do you understand by pure substance? 2. Define thermodynamic system. 3. Name the different types