Adiabatic Saturation Temperature Psychrometric Chart Fuels and Combustion Amount of Air Required for Combustion Steam Generators Boller Mountings and Accessories Boller Draught and Performance Steam Engines Efficiencies ofa Steam Engine Steam Turbines Engine-Cooling System Reciprocating Air Compressor Reciprocating Compressor Terminology Rotary Compressor Jet and Rocket Propulsions Air-Conditioning Elements of Heat Transfer I observed that customarily, major problems are faced by students in understanding the text and illustrations.
The presentation is simple, lucid and easy to understand, The topics are explained right from the Fundamentals withthe help of illustrative figures, enabling even a beginner to understand the subject very easily. This approach will help the students in developing an analytical mind. Chapter 1 provides an overview of the basic concepts of thermodynamics. Energy is basic requirement for work transfer.
Chapter 2 gives a detailed treatment of energy and its forms, work and heat transfer. Applications ofthe first law of thermodynamics to non-flow processes for closed systems and flow processes open systems or control volume are explained with support of several examples in Chapters 4 and 5, respectively The second law of thermodynamics is treated in a comprehensive manner in Chapter 6 and prolonged in Chapter 7 with the concept of entropy.
Other second-law concepts, availability and irreversibility, ate introduced in Chapter 8 along with the development ofa procedure for performance evaluation ofa system. Chapter 10 deals with compressible fluid flow, It uses the concept of the fist and second laws for a moving fluid. The comprehensive thermodynamic analysis of gas power eycles Chapter 11 , vapour power cycles Chapter 12 , refrigeration cycles Chapter 13 , ideal gas mixtures Chapter 14 and psychrometry Chapter 15 are carefully considered.
Emphasis is given to steam engineering from Chapter 17 to Chapter Chapter 17 gives an overview of different types of boilers. Chapter 18 incorporates various important oiler mountings and accessories. Even though steam engines are obsolete nowadays, still the concept and preliminary analysis of steam engines are taken up in Chapter Chapter 23 gives an elementary treatment to steam condensers. The internal combustion engines are discussed in Chapter 24, Chapters 25 and 26 take up the analytical treatment to reciprocating and rotary air compressors.
Hoxoever readers are fret follow the sequence of her choc. He has provided required support from time to time. Some mistakes might have crept in the text, My efforts in writing this book will be rewarded if readers send their constructive suggestions and objective criticism with view to improve the usefulness of the book. Piracy related issues may also be reported. In some chopters, the whole concept is Dicturised withthe help ofa simple figure. These ore very helpful to teachers in set ting class work, assignments, quizzes and examinations.
For easy understanding the properties of elements, a large variety of tables and Graphs are provided in Appendices—A, B, and c. It also deals with thermodynamic equilibrium and feasibility of processes Every engineering activity involves an interac- tion between energy and matter, and it is hard to find an area which does not relate to thermodynam- ies in some respect.
An ordinary house has a gas stove, an electric iron, fans, a cooler, a refrigerator, pressure cooker and televisions. The design of each item requires the knowledge of thermodynamics. The size, location and power input to an air-conditioner is decided after thermodynamic analysis ofa room, 1. The teal or imaginary surface that separates the system from ts surroundings is called the boundary. The system and its surroundings constitute the universe.
These terms are ilusrated in Fig 1. Homogencous and heterogeneous systems Figure 1. Eras Mess 0 oe Fig. Representaion ofa closed system 1. Gas Trapped within a Piston-cylinder Device, Fig. Food Items in a Pressure Cooker, Fig. Thus, energy crosses the boundary. Steam Thermal Power Plant Figure 1. The working substance is water vapour, The boiler, turbine, condenser, and feed pump together constitute a system.
Bulbs and Lamps, Fig. Other examples are thermos flask Fig. Thermos flask Itusually enclosesadevice Which involves mass flow, such as a compressor, turbine or nozzle. Flow through these devices is best studied by selecting a region within the devices a control volume. LL Some examples of open systems are discussed below. Flow through Tubes and Nozzles, Fig.
Water Boiler, Fig. Gi Energy as heat enters the control surface. Reciprocating Air Compressor Figure 1. The interior surface of eylinder and piston forms the control surface Tet ree t ftw Fig.
Energy as work and heat can cross the contol surface C 4. Internat combustion engines, gas turbine, Fig. Insulated turbines, throttle valves, water pumps, water turbines, insulated heat exchangers, ete, are some examples of adiabatic systems.
Fluid enters and leaves the control surface. Therefore, important that we must recognise the type of system before analysing it, Ifenergy transfor does [17 heat transfer does rot take place across not take place across the boundary then the the contol surface closed system is called then an open aystem an isolated system.
It is treated as one constituent for is analysis. The macroscopic approach in the study of thermodynamics is also called classical thermodynamics. Wt provides. The structure of the matters not considered, 2. Only a few variables are needed to describe the state ofthe system, 3. Thus, this approach is also called statistical thermodynamics. In the microscopic approach, 1. The knowledge ofthe structure of the matter is necessary 2.
A large number of variables are needed to and its imtergration cannot be evaluated unless the relationship between p and is known, Thus the quantity pa is not A propery. Here, vis functionally related with p, and thus bythe same teasing as given in i , the quantity ndp isnot a property Example 1. It is called a change of state, A locus of series of states through which a system passes between initial and inal states is called a path as shown in Fig1.
A process undergone by a fluid in a closed system, is referred asa non-flow process 2. A process undergone by a fluid in an open system is referred as a flow process 3. When a process proceeds in such a manner that the system remains almost infinitesimally close to equilibrium, such process is called a quasi-static process 4. A process which cannot be reversed by the same path, and follows in one direction only is called an irreversible process, It passes through a serics of non equilibrium states, 6.
When a system undergoes a process, while enclosed by an adiabatic wall ideal insu- lator , the system does not experience any heat exchange between the system and its surroundings. Such a process is called an adiabatic process.
Point functions can be represented by a point on any plot, e. These properties have exact differentials designated by the symbol d. The path functions have inexact differentials represented by the symbol 5. A quasi-static process is viewed as a sufficiently slow process in Which system changes its state very slowly under the influence of an infinitesimally small driving force. The piston is loaded by number of small masses. As one mass is removed, the gas expands slightly, allowing the piston to move slowly upward.
First these are easy to analyse; and second, work- producing devices deliver the maximum work, and Wworkabsorbing devices require minimum work when they operate on quasi-equilibrium processes.
A systems said to bein equilibrium stare when there is no unbalance potential driving force within the system. It means thatthe intensive propertics are same throughout the entire system land there is no tendency for a change of state. If two systems are in the same intensive stat, they are in equilibrium with each other. I'the system and its surroundings are in the same intensive state, they are also in equilibrium state. The force is directly related with pressure. When any oncofthe above conditions of equilibrium ate not satisfied, the system isnot considered to be in thermodynamic equilibrium.
Pressure pascal Pa kgim. Symbols of unit names derived after scientist's names are always writen with an inital capital letter. If the symbol of a unit is not derived from scientist's name, i is writen with a small letter. The symbols of units do not take a plural form. For example, the length ofan object can be writen as 5 mor 5 metres bbut not 5 ms.
No full stop or other punctuation mark is placed after symbols, unless they appear a the end ofa sentence. For better appearance, a single space must always be provided between a numerical value and a symbol ofa unit, 1. We speak of pressure only when we deal with a gas of liquid. The counterpart of pressure in a solid is stress, If Fis the force normal to the area 4, then - wm?
Gauge Pressures 0 Atmospheric Pressure tis the pressure exerted by the envelope of air surrounding the earth's surface. The standard atmospheric pressure is equal to the pressure produced by mm high column of mercury, the density of mercury being 13, kim?
This difference is called gauge pressure. In a piston-linder arrangement, the pressure is imersely proportional the square ofthe Volume. The inl pressure 10 bar athe ender and the intel vole is. The volume now chonged 5 that thf preset 2 bar. Take the atmospheric pressure as I bar rene Fig. For example, forthe energy interaction betwoen a system and its surroundings, the energy lost by a system must be exactly equal to the amount of energy gained by the surroundings.
Lotus considera process that involves only heat transfer but no work interaction. A hot potato taken from an oven is exposed to room aie as shown in Fig 2. As a result of heat transfer from the hot potato its energy will deerease. That is, ae oonse : Qh ws Jose. The ener- ay interactions are recognised at the system bound- ary as they cross it, and direction of energy transfer represents the energy gain or loss by a system dur- ing a process.
Heat Transfer, Q. A rising piston, rotating shaft, and an cleetric wire carrying current crossing the system boundary—all these energy transfers are associated with work interactions. Thus process 4 and process 2B form a cycle. Thus, we formulate the frst law of thermodynamics fora process. The integration ofeach side of Eq, 2. Thus, the energy is a stae function and property. The part of electricity gen- erated by the plant is to be used for the resistance heating and pump work, The rest ofthe eletrcity js the net output of the plant.
Therefore, such a device js called the perpetual motion machine ofthe first kind PMI , whieh is impossible Example 2. The temperatures must be used in Kelvin K. Thus, external work is done by steam due to increase in specific volume. Identify the ope of steam in the lowing three cass, using the steam bles and ging ecesetrycalcalatonsmpporing you cai 6 2g of steam a 8 bar with an enthalpy of The specific heat of superheated steam at constant pressure is 2. Sat Temp] Sp. Dry and saturated steam, and 1.
Tae specific heat for superheated stam as 2. This latent heat is used to overcome the molecular forces of traction andthe specific hea of water Becomes infinity during phase change. Working Substances 77 6 As- lower limit ithe steam is completely wet, the mass of vapour willbe zero. Then the above relation yields to zero dryness. We shall discuss the following calorimeters inthis text 1. Barrel Calorimeter 2. Separating Calorimeter 3. Throttling Calorimeter 4 ned separating and throttling ealori- 3.
As stam condenses, the mass land temperature of water inerease. Borre calorimeter quating and i , we get the dryness fraction, Where m.
Example 3. The fankis made of copper is 10 in mars and has a specie. A sample of wet steam ata pressure p is taken from the steam main through a perforated Working Substances 79 Fig.
Ihe steam is very wet then the resultant dryness fration obtained by this technique is not very accurate Example 3. The wet steam taken from a steam main via a steam stop valve is fist passed through a separating calorimeter. Some part of the moisture is removed from steam, due to sudden change in its direction. The resulting semi-dry steam is then throttled into throttling calorimeter. The steam coming out the throttling calorimeter is superhcated at a pressure pz and temperature Ts, The theotling calorimeter is well insulated to prevent any heat loss.
The mass of steam condensed after thotling wat 2. Take specific. Ithas no intermolecular forces of attraction or repulsion, 2. It does not change its phase during a thermodynamic process 3. Dense gases, such as water vapour, reftigerant however, should not be treated as ideal Boyle's law represents a rectangular hyperbola curve, This curve is als called an isotherm and the process ocurring at constant temperature is known as an isothermal process.
Teper Fig. Any equation tht relates the pressure, temperature and specific volume of a substance is known as an equation of tae. Universal G: constant, Ry When the molecular mass of any gas M is multiplied by its specific gas constant R , itis observed that the product MR is always same forall gases. This product is called universal gas constant and itis denoted as R, RMR an, For SI system, the value of the universal gas constant is 8.
Calculation of R The value of the gas constant is determined from dividing the universal gas constant 2, by its molecular mass M1 as pe M Table 3. G48 3. Avogadro's Law or Avogadro's Hypothesis Ie snes that the molecular mass of all perfect toes occupies te same volume under Meat onaitions of pressure and temperature.
Assume atmospheric pressure tobe 1. Assumptions Airis an ideal gas. Determine the gas pressure in bar. Determine the mass and munber of moles of air displaced bythe balloon If hydrogen gas is filled in the balloon under the same conditions of temperature and pressure, calculate the mass and number of mole of hydrogen.
Molecular masses of air and hydrogen are taken as The speci. Analysis i Heat supplied at constant pressure Q. These are Reduced pressure py 2. The results obtained by using compressibility chart are Working Substances 91 accurate within few percentage, The deviation of real-gas behaviour from that of ideal gas is greatest in vieinity of the critical point, Better results ean be obtained for some gases by using pscudo-reduced coordinates in place of reduced properties.
For superheated steam tbe ideal gas aye 22 comsazowe p iB OPA 3. Von der Waals Equation In , 1D. Re Sip. Despite of its limitations, the van der Waal equation has a historical impor- tance because it was the fist attempt to model the behaviour of real gases.
Working Substances 93 6. Nz Virial Equation of State The equation of sate for areal gas canbe expressed inthe frm of power Bayt bed RT i an where a,b 6 dy ete are second, thd, fourth, ct, Vital coeficints and these ae function of tem- perature only.
SRy mol? The gas is allowed to expand until the pressure is KPa and final volume is 4 times the inital volume. An sloplne has two tyres that are inflated to kPa. Each tyre has a volume of 0. What other considerations are involved in deciding whether t use helium? Then it is throttled to 8 pres: sure of 5. Calculate the temperature of steam immediately after throting and dryness fection of seam before and ate he separator.
Caeulte the final temperature, work done, het transferred and change in entropy. Example 47 Air initially at 60 KPa pressure, K temperature and 0. C where log. Fora given mass system, itis pv C consant 0 Relation between p, V and T The thermody- namie properties fora perfect gas ae elated as on 2. C kis K Fig. The following equation, which com sects pand vfor several gases is wnat bpv where a and b are constants, Prove that fora reverseble ediabate process bat po?
The gasis then expanded adiabatically tna its volume is 1. Assumg The system is non-ow, and i Airisa perfect gas. TF edingram Fig 4. Each of the four processes dis- cussed earlier can also be represented by polytropic process as Fig.
This includes heat transfer in the case of a convection-dominated system and a radiation-dominated system. It also discusses a bit about internal heat transfer in a plate with fins. A good amount of information is provided about the specific properties that play into each scenario and how they can be calculated using boundary conditions or by using Fourier's law.
Here, the author provides a detailed discussion of how thermal conductivity can be applied to determine the rate of heat transfer in different geometries. These include diffusion-controlled methods, mass transfer methods, and material processes such as phase change or crystallization. Availability and Irreversibility 8. Availability of Energy Entering a System 8. Thermodynamic Relations 9. Helmholtz and Gibbs Function: Gibbsian Equations 9. Compressible Fluid Flow Gas Power Cycles mn "2 Vapour Power Cycles na n2 23 Ra ns na 28 n9 Amagat-Leduce Law of Additive Volumes Psychrometry Adiabatic Saturation Temperature Psychrometric Chart Fuels and Combustion Amount of Air Required for Combustion Steam Generators Boller Mountings and Accessories Boller Draught and Performance Steam Engines Efficiencies ofa Steam Engine Steam Turbines Engine-Cooling System Reciprocating Air Compressor Reciprocating Compressor Terminology Rotary Compressor Jet and Rocket Propulsions Air-Conditioning Elements of Heat Transfer I observed that customarily, major problems are faced by students in understanding the text and illustrations.
The presentation is simple, lucid and easy to understand, The topics are explained right from the Fundamentals withthe help of illustrative figures, enabling even a beginner to understand the subject very easily. This approach will help the students in developing an analytical mind. Chapter 1 provides an overview of the basic concepts of thermodynamics. Energy is basic requirement for work transfer. Chapter 2 gives a detailed treatment of energy and its forms, work and heat transfer.
Applications ofthe first law of thermodynamics to non-flow processes for closed systems and flow processes open systems or control volume are explained with support of several examples in Chapters 4 and 5, respectively The second law of thermodynamics is treated in a comprehensive manner in Chapter 6 and prolonged in Chapter 7 with the concept of entropy. Other second-law concepts, availability and irreversibility, ate introduced in Chapter 8 along with the development ofa procedure for performance evaluation ofa system.
Chapter 10 deals with compressible fluid flow, It uses the concept of the fist and second laws for a moving fluid. The comprehensive thermodynamic analysis of gas power eycles Chapter 11 , vapour power cycles Chapter 12 , refrigeration cycles Chapter 13 , ideal gas mixtures Chapter 14 and psychrometry Chapter 15 are carefully considered. Emphasis is given to steam engineering from Chapter 17 to Chapter Chapter 17 gives an overview of different types of boilers. Chapter 18 incorporates various important oiler mountings and accessories.
Even though steam engines are obsolete nowadays, still the concept and preliminary analysis of steam engines are taken up in Chapter Chapter 23 gives an elementary treatment to steam condensers. The internal combustion engines are discussed in Chapter 24, Chapters 25 and 26 take up the analytical treatment to reciprocating and rotary air compressors. Hoxoever readers are fret follow the sequence of her choc.
He has provided required support from time to time. Some mistakes might have crept in the text, My efforts in writing this book will be rewarded if readers send their constructive suggestions and objective criticism with view to improve the usefulness of the book.
Piracy related issues may also be reported. In some chopters, the whole concept is Dicturised withthe help ofa simple figure. These ore very helpful to teachers in set ting class work, assignments, quizzes and examinations. For easy understanding the properties of elements, a large variety of tables and Graphs are provided in Appendices—A, B, and c. It also deals with thermodynamic equilibrium and feasibility of processes Every engineering activity involves an interac- tion between energy and matter, and it is hard to find an area which does not relate to thermodynam- ies in some respect.
An ordinary house has a gas stove, an electric iron, fans, a cooler, a refrigerator, pressure cooker and televisions.
The design of each item requires the knowledge of thermodynamics. The size, location and power input to an air-conditioner is decided after thermodynamic analysis ofa room, 1. The teal or imaginary surface that separates the system from ts surroundings is called the boundary. The system and its surroundings constitute the universe.
These terms are ilusrated in Fig 1. Homogencous and heterogeneous systems Figure 1. Eras Mess 0 oe Fig. Representaion ofa closed system 1. Gas Trapped within a Piston-cylinder Device, Fig. Food Items in a Pressure Cooker, Fig. Thus, energy crosses the boundary. Steam Thermal Power Plant Figure 1. The working substance is water vapour, The boiler, turbine, condenser, and feed pump together constitute a system.
Bulbs and Lamps, Fig. Other examples are thermos flask Fig. Thermos flask Itusually enclosesadevice Which involves mass flow, such as a compressor, turbine or nozzle. Flow through these devices is best studied by selecting a region within the devices a control volume. LL Some examples of open systems are discussed below. Flow through Tubes and Nozzles, Fig. Water Boiler, Fig. Gi Energy as heat enters the control surface.
Reciprocating Air Compressor Figure 1. The interior surface of eylinder and piston forms the control surface Tet ree t ftw Fig. Energy as work and heat can cross the contol surface C 4. Internat combustion engines, gas turbine, Fig. Insulated turbines, throttle valves, water pumps, water turbines, insulated heat exchangers, ete, are some examples of adiabatic systems.
Fluid enters and leaves the control surface.
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