Application of First Law of Thermodynamics
The application of the First Law of Thermodynamics in technology and engineering involves the conservation of energy within a system. This principle is used to analyze and design various energy conversion processes, such as engines, power plants, and refrigeration systems. By accounting for the transfer of heat and work within these systems, engineers can optimize their efficiency and performance.
8 Key excerpts on "Application of First Law of Thermodynamics"
eBook - ePub- Mike Pauken(Author)
- 2011(Publication Date)
- For Dummies(Publisher)
...energy reservoirs Harnessing heat engines and estimating their efficiency Regulating refrigerators and calculating coefficients of performance Ralph Waldo Emerson said, “Build a better mousetrap and the world will beat a path to your door.” This sentiment has been the mantra of many inventors, even before Emerson came along and expressed it so eloquently. Since the dawn of human civilization, people have thought of countless ways to do more work with less effort. Some have even tried to get work done without any effort at all. People have put a lot of thought and effort into trying to invent perpetual-motion machines, but to no avail. The second law of thermodynamics is useful for determining what is and isn’t possible when it comes to building a better “mousetrap” that uses energy to produce work or work to move heat. Many perpetual motion concepts can obey the first law of thermodynamics, which is the conservation of energy principle, but they still aren’t possible. If you fire a bullet into a block of wood, the kinetic energy of the bullet is converted to heat because energy is conserved. But have you ever heard of a bullet lodged in a block of wood cooling off and firing itself out of the wood block? The energy is still conserved, but this process isn’t possible. I introduce the first law of thermodynamics in Chapter 2 and apply it to several systems in Chapters 5 and 6. In this chapter, I introduce you to the second law of thermodynamics. The second law shows there are limits to the way heat is converted to work and the way work moves heat from a cold place to a warm one. The second law of thermodynamics can’t easily be defined in a simple, single sentence like the first law. Instead, it describes a set of connected concepts about energy. It’s almost like a Bill of Rights for energy rather than just a law. Just as the Bill of Rights describes the limits of the U.S...
eBook - ePub- Tangellapalli Srinivas(Author)
- 2021(Publication Date)
- Bentham Science Publishers(Publisher)
...The performance can be solved using first law of thermodynamics. First law of thermodynamics focuses on energy. It says that energy can be converted from one from to another. It can be destroyed or created and just converts only. So the energy of universe is constant. The first law of thermodynamics provides the base for measurement of energy through the properties. But it has certain limitations as it is not in complete form. It is focused on transfer of energy quantities without dealing the quality transformation. The study on energy conversion direction is missing. It will not say that the process is feasible or not. Since the first law explains the energy conversion, it defines the energy conversion efficiency or first law efficiency of a process or cycle. It also called as thermal efficiency which is the ratio of output to input. Joule conducted an experiment to demonstrate the first law of thermodynamics applicable to a cycle. Let a certain amount of work W 1-2 be done upon the system by the paddle wheel. The quantity of work can be measured by the product of weight and the vertical height through which the weight descends. The work input to the insulated vessel causes a rise in the temperature of the fluid. For the process 1-2, Q + U 1 = W + U 2 (3) He conducted the experiment in a water container with insulation. The temperature of water is increased by the stirrer work. The work done on the system, U 1 + W = U 2. The temperature of water increases from T 1 to T 2. The work is used to rise the internal energy of the system i.e. U 2 – U 1. In second step, the insulation is removed and the water bath is inserted into another water container. The heat is transfer to the water and the system gains its original state. For the process 2-1, U 2 + Q = U 1 (4) Since there is no work, the heat rejection is equal to decrease in internal energy i.e. U 2 – U 1. Now the system under goes two process one is forward the second the backward and completes a cycle...
eBook - ePubThe Myth of Progress
Toward a Sustainable Future
- Tom Wessels(Author)
- 2013(Publication Date)
- University Press of New England(Publisher)
...Carnot’s observation certainly wasn’t new. But he took his observation a step further by showing that Newtonian mechanics couldn’t explain such a unidirectional movement. The result of his work launched a new branch of physics known as thermodynamics. By 1865 the German physicist Rudolf Clausius had drafted the first and second laws of this young science. The first law of thermodynamics, also known as the law of conservation of energy, simply states that energy can neither be created nor destroyed. This means that the amount of energy in the universe today is exactly what it was thirteen billion years ago, just after the Big Bang. This is a powerful concept, but from a practical standpoint it’s the second law of thermodynamics that is the most important to us. The second law, also known as the law of entropy, states that although energy can’t be created or destroyed, it can be transformed from one form to another. As I type, some of the electrical energy that runs my computer originally came from the decay of uranium atoms within the Vermont Yankee nuclear power plant. As a uranium atom breaks apart, a minute amount of the mass of its nucleus is transformed into heat energy. The heat energy is used to produce steam. The steam then turns electric turbines, this transformation producing kinetic energy, the energy of motion. The kinetic energy of the rotating turbines is then transformed into electrical energy. The electrical energy enters my computer and is transformed into light and the words that appear on my screen, finally being transformed into heat that dissipates into my room. Throughout all these transformations no new energy has been created and none has been destroyed. But the transformation of energy from one state to another is not the critical aspect of the second law. The critical point is that although energy can be transformed, no transformation is 100 percent efficient...
eBook - ePub- V. Babu(Author)
- 2019(Publication Date)
- CRC Press(Publisher)
...CHAPTER 8 SECOND LAW OF THERMODYNAMICS In this chapter, the second law of thermodynamics is introduced from the perspective of the performance of devices (engines) that execute a cyclic process. Two different statements of the law are given and discussed. Most importantly, their equivalence is established. Limits imposed by the second law on how best these devices can perform are also discussed. 8.1 Need for the second law Consider again the example discussed in section 4.1, where 100 J of energy is transferred to the system in three different ways to be converted to work. It was said that when heat is supplied to a system, it is utilized to increase the energy associated with molecular motion, which is disordered. Hence, it cannot be converted entirely into work. In an engineering context, years of efforts to improve the performance of engines that convert heat into work, and run continuously, led to the realization that there is fundamentally a limit on how efficient such engines can be, even under ideal circumstances. Interestingly enough, the first law, Eqn. 4.1, seemed to place no such restriction - the heat supplied could entirely be converted to work without violating it. This conflict suggests that there is another fundamental law in action. In addition, first law is also unable to explain the preferred directionality of many processes that are seen in nature. For instance, mixing takes place most readily on its own, however, once mixed, the constituents never have been seen to separate out on their own. Air in a high pressure vessel escapes most easily on its own but the reverse does not happen spontaneously. Most, if not all, spontaneous processes † in nature always take place in one direction on their own but not in the opposite direction, although the first law does not forbid this from happening. The above considerations clearly bring out the need for a second law...
eBook - ePub- RogerTim Haug(Author)
- 2018(Publication Date)
- Routledge(Publisher)
...One of the central themes of this book is the application of thermodynamic principles to composting systems, which by their nature are composed of physical, chemical, and biological processes. No single science unifies the diverse aspects of composting as does thermodynamics. The First and Second Laws of Thermodynamics form the foundation upon which the science is based. Both are accepted as first principles that have been repeatedly upheld by human observations. The First Law states that energy can be neither created nor destroyed. In engineering terms it is commonly referred to as the Law of Conservation of Energy. The concepts of heat, work, internal energy, and enthalpy are related to the First Law. The Second Law resulted from a search to explain the direction in which spontaneous processes would occur. This led to the realization that all spontaneous changes in an isolated system occur with an increase in entropy or randomness. The concept of free energy was developed from the First and Second Laws. Free energy gives the useful work which can be derived from a chemical reaction that occurs under constant pressure and temperature conditions. This is extremely useful because most microbial processes occur under such conditions. Therefore, a measure exists of the useful energy available from the feed substrate being used by a microbial population. All chemical reactions have a standard free energy change, measured with all reactants and products at unit activity (approximately a 1 M concentration). Spontaneous chemical reactions proceed in the direction of decreasing free energy. If the free energy change is zero the reaction is at equilibrium...
eBook - ePubBiomolecular Thermodynamics
From Theory to Application
- Douglas Barrick(Author)
- 2017(Publication Date)
- CRC Press(Publisher)
...chapter 3 The Framework of Thermodynamics and the First Law Goal and Summary The goals of this chapter are twofold. First, to give students an understanding of the logic of thermodynamic analysis, key concepts are described, including the differences between macroscopic and microscopic (or “statistical”) approaches to thermodynamics, the partitioning between “system” and “surroundings,” the concepts of reversibility and irreversibility, and the importance of the equilibrium state and corresponding equations of state. These concepts are key to understanding the first and second law (Chapter 4), the connection to free energy (Chapters 5 through 8), and the different types of statistical ensembles that will be analyzed in Chapters 9 through 11. The second goal of this chapter is to introduce the first law of thermodynamics, re-enforcing the differences between path and state functions, and highlighting the use of simple state functions to calculate thermodynamic changes along complicated paths. General concepts of work will be introduced, focusing on expansion and compression of ideal gases. Heat flow will be described in terms of temperature changes and heat capacities. Considerable attention will be given to analysis of adiabatic expansion, to illustrate various approaches to thermodynamic analysis (empirical observation, comparison of alternative of paths, and differential approaches). We will conclude with a discussion of the van der Waals gas, to provide a picture of nonideality and its origins. What Is Thermodynamics and What Does It Treat? Thermodynamics describes the properties (especially energetic properties) of matter. As suggested from the first part of its name, thermodynamics describes properties that are “thermal” in nature, such as temperature, heat capacity, various forms of energy, and also energetic processes like heat flow and work...
eBook - ePubFrom Vehicles to Grid to Electric Vehicles to Green Grid
Many a Little Makes a Miracle
- Fuhuo Li, Shigeru Kanemitsu;Jianjie Zhang(Authors)
- 2019(Publication Date)
- WSPC(Publisher)
...the extensive variable and intensive variable, where the former depends on the change of the object while the latter does not change, e.g. the pressure remains the same during changes and it is often denoted by p rather than P. But we shall not adopt this distinction in most cases. The first law of thermodynamics or the law of conservation of energy is one of the most universal laws that governs our space. In addition to the symbols P, V, T introduced in § 2.1, we need a few more to describe the basics of thermodynamics. We consider an isolated thermodynamical system, where isolated means that the system does not give or receive heat from outside sources. Although we are to use p to denote the state quantity, we follow the notation commonly used. • U means the inner energy • Q means the heat • W means the work • means the entropy The last is a temporary definition of entropy and a more proper definition is given by where d Q rev is the infinitesimal change of the heat under a reversible process and d S i rr is that of the entropy under an irreversible process. Also, to be most precise, we need to place a conversion factor = mechanical equivalent to heat, to convert the heat in work: where Q 2 and Q 1 are the heat exerted on and emitted from the system and W is the work done on the system. However, we may discard this factor if we measure the heat in Joules. Or if we take the ratio, such as heat efficiency, this disappears. As we have the equation of state (2.2), we always have a relation between these variables and the situation is such that there are only two variables can be independent. The first law of thermodynamics then reads i.e. the sum of the energy exerted on an object, to change its state, in the form of work W and of heat Q is independent of the way they are exerted. This implies the negation of the existence of a perpetual engine of the first kind, i.e. “Realizing a system which repeats a cyclic movement (e.g...
eBook - ePubEssentials of Energy Technology
Sources, Transport, Storage, Conservation
- Jochen Fricke, Walter L. Borst(Authors)
- 2013(Publication Date)
- Wiley-VCH(Publisher)
...Chapter 3 Thermodynamic Energy Efficiency The conversion of most forms of primary energy to useful energy is still highly inefficient today. Only about one-third of the primary energy is actually put to use (Figure 3.1). There are several reasons for this: relatively low energy costs (especially in the United States), marginal incentives for higher efficiency, and fundamental thermodynamic limitations. Figure 3.1 Typical flow of energy in an industrialized country, here Germany. Most primary energy comes from coal, natural gas, oil, and uranium. The end energies are electricity, gasoline, and diesel fuel, for industry, trade, heating and air conditioning, transportation, and so on. (Source: Adapted from Ref. [1].) 3.1 Carnot's Law The proper application of thermodynamics is the key for higher energy efficiency. The upper limit for the conversion of heat into useful work is given by Carnot's law: 3.1 where η C is the energy efficiency of the Carnot engine (Figure 3.2) operating between two reservoirs at absolute temperatures T h (hot) and T c (cold). First described by Sadi Carnot in 1824, this law shows that the higher the temperature T h is for a fixed T c, the higher is the efficiency. In the Carnot engine, all processes are assumed to be reversible and infinitely slow so that the system is in equilibrium at all times. Figure 3.2 (a) Energy flow chart for the Carnot process. (b) Pressure-Volume (pV) diagram. The shaded area of the closed loop is the extracted work W. (c) Temperature–Entropy (TS) diagram. Vertical transitions represent isentropic (adiabatic) processes. Two adiabatic and two isothermal processes make up the closed cycle, in which heat Q 34 at high temperature T h is used to produce work W, with heat Q 12 discharged at low temperature T c. The efficiency η C in Eq. (3.1) is defined as the work W divided by the provided heat Q 34. Applying the first law of thermodynamics (conservation of energy), we know that 3.2 and we obtain 3.3 Problem 3.1 Derive Eq...
