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SECTION-A(ii)

SECTION-A(ii). Basics of thermodynamics. Syllabus (ME-101-F). Section-A Introduction to machine tools Basic Concepts of thermodynamics Properties of steam & steam generators Section-B Refrigeration & Air conditioning. Hydraulic turbines & pumps. Section-C

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SECTION-A(ii)

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  1. SECTION-A(ii) Basics of thermodynamics For more info. : www.goodwisher.com

  2. Syllabus(ME-101-F) • Section-A • Introduction to machine tools • Basic Concepts of thermodynamics • Properties of steam & steam generators • Section-B • Refrigeration & Air conditioning. • Hydraulic turbines & pumps. • Section-C • Power transmission methods & devices • Stresses & strains • Section-D • Introduction to manufacturing system(NC & CNC Machining) For more info. : www.goodwisher.com

  3. Topics • Introduction, • States, Work, Heat, Temperature, • 1st law of thermodynamics • 2nd law of thermodynamics • 3rd law of thermodynamics, • Zeroth law of thermodynamics • Internal energy, • Enthalpy and entropy. For more info. : www.goodwisher.com

  4. Thermodynamics • Thermodynamics is a branch of science that deals with energy transfer & its effects on the state or the condition of the system. For more info. : www.goodwisher.com

  5. Thermodynamic System, Sorrounding & Boundary Sorrounding SYSTEM Boundary For more info. : www.goodwisher.com

  6. System • Thermodynamic system refers to a prescribed & identifiable quantity of matter under consideration to analyze a problem. For more info. : www.goodwisher.com

  7. Sorroundings • The combination of matter & space external to the system,that may be influenced by the changes in system is called sorrounding. For more info. : www.goodwisher.com

  8. Boundary • Thermodynamic system & sorroundings can be seperated by an envelope called boundary. • It represents the limit of the system • It may be real or imaginary. For more info. : www.goodwisher.com

  9. Types of systems • There are 3 types of systems:- • OPEN SYSTEM • CLOSED SYSTEM • ISOLATED SYSTEM For more info. : www.goodwisher.com

  10. OPEN SYSTEM Energy transfer as work • A system which can exchange mass with the sorrounding along with the transfer of energy in the form of heat & work. • Example:Motor car engine. MASS IN MASS OUT Energy transfer as heat For more info. : www.goodwisher.com

  11. CLOSED SYSTEM Energy transfer as work • A system which can exchange energy in the form of heat & work,with its enviornment,but there is no mass transfer across the system boundary. • Example:Motor car battery Mass constant Energy transfer as heat For more info. : www.goodwisher.com

  12. Isolated System • A system which exchanges neither mass nor energy with the sorrounding . • Example:Universe Fixed mass & energy For more info. : www.goodwisher.com

  13. THERMODYNAMIC PROPERTY • It refers to the characterstics,which can be used to describe the condition or the state of a system. • It is of 2 types:- • Intensive properties:-The properties,which are independent of mass are called intensive properties. Example:Pressure,volumeetc • Extensive properties:-The properties which are dependent on the mass are called intensive properties. Example:Enthalpy,Entropy,Internal energy For more info. : www.goodwisher.com

  14. Thermodynamic State 1 2 P 1 & 2 are the states V For more info. : www.goodwisher.com

  15. Thermodynamic state(Contd….) • It is the condition of the system, identified by the thermodynamic properties. • With properties as coordinates, States can be represented by a point. • Any operation in which change of properties of a system shanges is called change of state. For more info. : www.goodwisher.com

  16. THERMODYNAMIC PATH 1 A 2 P 1-A-2 is the PATH V For more info. : www.goodwisher.com

  17. THERMODYNAMIC PATH(Contd…..) • The locus of series of states through which a system passes in going from initial to final state is called a path. For more info. : www.goodwisher.com

  18. Thermodynamic process 2 A 1 P 1-2 is the process V For more info. : www.goodwisher.com

  19. Thermodynamic process • A complete specification of the path is referred to as process. • A thermodynamic process represents a transition in which a system changes from one state to another. • When a system in a given state undergoes through a series of processes such that the final & initial state is identical, a cyclic process is said to have been executed. For more info. : www.goodwisher.com

  20. SUMMARY(STATE,PATH,PROCESS) 1 B 2 P 3 A A & B are the states A-1-B is the path A-2-B is the path. A-3-B is the path A-B is a process. A-B-A is a cyclic process. V For more info. : www.goodwisher.com

  21. WORK • It refers to the interaction between system & sorrounding whose sole effect, external to the system could be the reduced to lifting of mass against gravitational force. • Sign conventions: • +W---------Work done by the system • -W----------Work done on the system For more info. : www.goodwisher.com

  22. HEAT • HEAT is defined as the form of energy that is transferred across the boundaries of the system because of temperature difference between the system & its sorroundings. • Sign conventions: • +Q--------Heat transferred to the system. • -Q---------Heat transferred from the system. For more info. : www.goodwisher.com

  23. Temperature & temperature scale • Temperature scale is referred to a thermometer for measuring the inequality of temperature.To construct a thermometer two reference points are chosen,namely ice point & steam point. • Relation between temperature sacles: • Relation between Celsius to Farenheit: • F= • Relation between celsius& kelvin: • K=C+273 For more info. : www.goodwisher.com

  24. ZEROTH LAW OF THERMODYNAMICS • When two systems have equality of temperature to a third sytem, then they in turn have equity of temperature with each other. • A • B • A B C C For more info. : www.goodwisher.com

  25. First law of thermodynamics • It is the case of law of conservation of energy. • Energy can neither be created nor can be destroyed . • Total energy of a System remains constant. For more info. : www.goodwisher.com

  26. First law(contd…) • “if a system undergoes a cyclic process, then the algebraic sum of work delivered to the Surroundings is proportional to the algebraic sum of heat taken from surroundings”. For more info. : www.goodwisher.com

  27. POINT FUNCTION & PATH FUNCTION • PATH functions have inexact differentials designated by • Therefore , differential amount of work & heat is represented by &. • Point functions have exact differentials designated by symbol d. • Properties are point functions , they depend upon the state,& not on how the system reaches that state. • Ex:- dT or dP. For more info. : www.goodwisher.com

  28. Energy is a property of the system Invoking first law for the process 1-A-2-B-1 Similarly,for process 1-A-2-C-1 FROM 1 & 2 A 1 B 1 P C 2 2 SO,it can be concluded that V For more info. : www.goodwisher.com

  29. Energy is a property of system(contd..) • The function is called the internal energy of the system. • Hence =dE • +dE • The energy E includes all forms of energy in the system. • E=U+K.E + P.E + Chemical energy+ electrical energy+………. • So , internal energy is the sum of all microscopic forms of energy of the system. • It is energy associated with the molecular structure of particles of system. For more info. : www.goodwisher.com

  30. 2ND law of thermodynamics(KELVIN-PLANK STATEMENT) HEAT SOURCE HEAT SOURCE Q1 Q H.E W=Q1-Q2 H.E W=Q Q2 IMPOSSIBLE HEAT SINK POSSIBLE “IT IS IMPOSSIBLE TO CONSTRUCT AN ENGINE THAT OPERATES IN A CYCLE & PRODUCES NO EFFECT OTHER THAN WORK OUTPUT & EXCHANGE OF HEAT IN SINGLE RESERVOIR.” For more info. : www.goodwisher.com

  31. 2ND law of thermodynamics(CLAUSIUS STATEMENT) HEAT SOURCE HEAT SOURCE Q1 Q1 Q1=Q2 W R R Q2 Q2 HEAT SINK HEAT SINK IMPOSSIBLE POSSIBLE “IT IS IMPOSSIBLE TO CONSTRUCT A DEVICE THAT OPERATES IN A CYCLE & PRODUCES NO EFFECT OTHER THAN TRANSFER OF HEAT FROM A SYSTEM OF LOWER TEMPERATURE TO HIGHER TEMPERATURE. For more info. : www.goodwisher.com

  32. ENTROPY • Entropy is the function of quantity of heat which shows the possibility of conversion of heat into useful work. • It increases with the addition of heat and decreases with its removal. • It is defined with respect to a reversible process. • Mathematically, • Where , T is absolute tempertature, is the increase in entropy For more info. : www.goodwisher.com

  33. Enthalpy • The sum of internal energy & flow work is defined as Enthalpy. • Enthalpy, h=u+pv • Where , u is the internal energy, • Pv is the flow work or work done. For more info. : www.goodwisher.com

  34. 3rd law of thermodynamics • At absolute zero , the entropy of all homogeneous crystalline substances in a state of equillibrium becomes zero. • Mathematically,SdT=0. • It implies that at absolute zero,the entropy ceases to be a function of state & approaches to a constant value independent of parameters. • For imperfect crystals , there is some entropy associated with the configuration of molecules & atoms. For more info. : www.goodwisher.com

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