DOCSLIB.ORG

Lecture 3 Thermodynamic Principles of Energy Conversion

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Lecture 3 Thermodynamic Principles of Energy Conversion Thermodynamic principles of energy conversion Md. Mizanur Rahman School of Mechanical Engineering Universiti Teknologi Malaysia 1 Introduction • Mechanical and electrical power developed from the combustion of fossil fuels or the fission of nuclear fuel or renewable sources • This released energy is never lost but is transformed into other forms • This conservation of energy is explicitly expressed by the first law of thermodynamics • The work of an engine cannot be the same as the energy available in the fuel sources • Second law of thermodynamics is to meet to happen the process 2 Forms of energy • Energy can exist in numerous forms such as thermal, mechanical, kinetic, potential, electric, magnetic, chemical, and nuclear, and their sum constitutes the total energy, E of a system. • Mechanical Energy • Kinetic energy, KE: The energy that a system possesses as a result of its motion relative to some reference frame, KE=1/2mV2. • Potential energy, PE: The energy that a system possesses as a result of its elevation in a gravitational field, PE=mgh • For a moving body, E=PE+KE remains constant 3 Internal energy, U: The sum of all the microscopic forms of energy. • For gases, molecules are so widely separated in space that they may be considered to be moving independently of each other, each possessing a distinct total energy. • In the case of liquids or solids, each molecule is under the influence of forces exerted by nearby molecules • Changes in internal energy are measurable by changes in temperature, pressure, and density. 4 • Chemical energy: The internal energy associated with the atomic bonds in a molecule. • Nuclear energy: The tremendous amount of energy associated with the strong bonds within the nucleus of the atom itself. Thermal = Sensible + Latent Internal = Sensible + Latent + Chemical + Nuclear 5 Energy form examples • In a gasoline engine, the combustion of the fuel–air mixture involves U, PdV and Echem • In a steam and gas turbine, only H and KE change • In a nuclear power plant fuel rod, U and Enuc are involved • In a magnetic cryogenic refrigerator, U and Emag are important. 6 The various forms of energy that can be possessed by a material body can be added together to define a total energy, to which we give the symbol E, Total energy per unit mass 7 Work and Heat interactions • Work Interaction W = pΔV Heat Interaction Q = mCpΔT 8 THE FIRST LAW OF THERMODYNAMICS • Energy can be neither created nor destroyed during a process; it can only change forms. • The First Law: For all adiabatic processes between two specified states of a closed system, the net work done is the same regardless of the nature of the closed system and the details of the process. • The change of energy in the system dE equals the heat dQ transferred to the system minus the work dW done by the system In a cyclic process, Ei=Ef I.e. Net heat and work are equal 9 A process must satisfy the first law to occur, however, satisfying the first law alone does not ensure that the process will actually take place. Processes proceed in a certain direction and not in the reverse direction In a process for which dQ = 0, which is called an adiabatic process, the entropy may remain the same or increase but may never decrease. An adiabatic process for which the entropy increases is an irreversible process. 10 The Carnot cycle is composed of four reversible processes—two reversible isothermal and two reversible adiabatic process Net work done during Carnot cycle In a P-V diagram the area under the process curve represents the boundary work for quasi-equilibrium (internally reversible) processes, The area under curve 1-2-3 is the work done by the gas during the expansion The area under curve 3-4-1 is the work done on the gas during the compression. The area enclosed by the path of the cycle (area 1-2-3-4-1) is the difference between these two and represents the net work done during the cycle. 12 REFRIGERATORS AND HEAT PUMPS Heat is transferred in the direction of decreasing temperature, that is, from high-temperature mediums to low temperature ones. The reverse process, however, cannot occur by itself. The transfer of heat from a low-temperature medium to a high-temperature one requires special devices called refrigerators and heat pump . 13 Coefficient of Performance The COP of a refrigerator can be expressed as 14 Rankine Cycle: The Ideal Cycle for Vapour Power Cycles . Many of the impracticalities associated with the Carnot cycle can be eliminated by superheating the steam in the boiler and condensing it completely in the condenser. The cycle that results is the Rankine cycle, which is the ideal cycle for vapor power plants. The ideal Rankine cycle does not involve any internal irreversibilities. 1-2 Isentropic expansion in a turbine 2-3 Constant pressure heat rejection in a condenser 3-4 Isentropic compression in a pump 4-5-1 Constant pressure heat addition in a boiler The simple ideal Rankine cycle 15 The simple ideal Rankine cycle 16 Energy Analysis of Basic Rankine Cycle (ideal) . The steam flows round the cycle and each process is analyzed using steady flow energy equation. Using energy balance for a steady flow system . For single stream (one-inlet-one-exit) systems, mass flow rate remains constant. If kinetic and potential energy are negligible, the energy equation becomes 17 Types of Gas Turbine Cycles There are two types of gas turbine cycle; Brayton/Joule cycle and Atkinson cycle Brayton Cycle . Heat added and rejected is at constant pressure 18 Brayton Cycle: Ideal Cycle for Gas Turbine Cycle . Gas turbines usually operate on an open cycle. Air at ambient conditions is drawn into the compressor, where its temperature and pressure are raised. The high pressure air proceeds into the combustion chamber, where the fuel is burned at constant pressure. .The high-temperature gases then enter the turbine where they expand to atmospheric pressure while producing power output. .Some of the output power is used to drive the compressor. .The exhaust gases leaving the turbine are thrown out (not re- circulated), causing the cycle to be classified as an open cycle. 19 Brayton Cycle - Closed Cycle Model .The open gas-turbine cycle can be modelled as a closed cycle, using the air-standard assumptions .The compression and expansion processes remain the same, but the combustion process is replaced by a constant-pressure heat addition process from an external source. .The exhaust process is replaced by a constant-pressure heat rejection process to the ambient air. 20 The Brayton Cycle Process .The ideal cycle that the working fluid undergoes in the closed loop is the Brayton cycle. It is made up of four internally reversible processes: . 1-2 Isentropic compression; . 2-3 Constant-pressure heat addition; . 3-4 Isentropic expansion; . 4-1 Constant-pressure heat rejection. .The T-s and P-v diagrams of an ideal Brayton cycle are shown beside. .Note: All four processes of the Brayton cycle are executed in steady-flow devices thus, they should be analyzed as steady-flow processes. 21 Otto and Diesel Cycle 22 Stirling cycle The ideal Otto and Diesel cycles are not totally reversible because they involve heat transfer through a finite temperature difference The irreversibility renders the thermal efficiency of these cycles less than that of a Carnot engine operating within the same limits of temperature. The Stirling cycle has two isentropic processes featured in the Carnot cycle 1-2 Isothermal heat addition (expansion) 2-3 Isochoric heat removal (constant volume) 3-4 Isothermal heat removal (compression) 4-1 Isochoric heat addition (constant volume) 23 Ericsson Cycle 1-2 Isothermal heat addition (expansion) 2-3 Isobaric heat removal 3-4 Isothermal heat removal (compression) 4-1 Isobaric heat addition The Ericsson cycle is often compared with the Stirling cycle, since the engine designs based on these respective cycles are both external combustion engines with regenerators. The most well-known ideal cycle is the Carnot cycle, although a useful Carnot engine is not known to have been invented. The theoretical efficiencies for both, Ericsson and Stirling cycles acting in the same limits are equal to the Carnot Efficiency for same limits. 24 FUEL CELLS • We see several different systems for converting the energy of fuel to mechanical energy by utilizing direct combustion of the fuel with air, each based upon an equivalent thermodynamic cycle. • In these systems, a steady flow of fuel and air is supplied to the “heat engine,” within which the fuel is burned, giving rise to a stream of combustion products that are vented to the atmosphere. • The thermal efficiency of these cycles, which is the ratio of the mechanical work produced to the heating value of the fuel, is usually in the range of 25% to 50%. 25 FUEL CELLS • This efficiency is limited by the combustion properties of the fuel and mechanical limitations of the various engines. • Is there a more efficient way to convert fuel energy to work? The second law of thermodynamics places an upper limit on the amount of work that can be generated in an exothermic chemical reaction, such as that involved in oxidizing a fuel in air. 26 • A fuel cell is an electrochemical device that converts chemical energy from a fuel into electrical energy without any moving parts • Fuel cells are operationally equivalent to a battery, but the reactants or fuel in a fuel cell can be replaced unlike a standard disposable or rechargeable battery 27 28 29 Group discussion Discuss with your friends about the following issues (5 minutes) 1. An modern engine can have more efficiency than a Carnot engine operating between same temperature limits? 2.
Load more

Recommended publications
  • An Analysis of the Brayton Cycle As a Cryogenic Refrigerator
    jbrary, E-01 Admin. BJdg. OCT 7 1968 NBS 366 An Analysis of the Brayton Cycle As a Cryogenic Refrigerator ITATIONAL BURSAL' OF iTANDABD8 LIBRABT MAR 6 J973 V* 0F c J* 0a <5 Q \ v S. DEPARTMENT OF COMMERCE in Q National Bureau of Standards %. *^CAU 0? * : NATIONAL BUREAU OF STANDARDS The National Bureau of Standards 1 was established by an act of Congress March 3, 1901. Today, in addition to serving as the Nation's central measurement laboratory, the Bureau is a principal focal point in the Federal Government for assuring maxi- mum application of the physical and engineering sciences to the advancement of tech- nology in industry and commerce. To this end the Bureau conducts research and provides central national services in three broad program areas and provides cen- tral national services in a fourth. These are: (1) basic measurements and standards, (2) materials measurements and standards, (3) technological measurements and standards, and (4) transfer of technology. The Bureau comprises the Institute for Basic Standards, the Institute for Materials Research, the Institute for Applied Technology, and the Center for Radiation Research. THE INSTITUTE FOR BASIC STANDARDS provides the central basis within the United States of a complete and consistent system of physical measurement, coor- dinates that system with the measurement systems of other nations, and furnishes essential services leading to accurate and uniform physical measurements throughout the Nation's scientific community, industry, and commerce. The Institute consists of an Office of Standard Reference Data and a group of divisions organized by the following areas of science and engineering Applied Mathematics—Electricity—Metrology—Mechanics—Heat—Atomic Phys- 2 2 ics—Cryogenics-—Radio Physics-—Radio Engineering —Astrophysics —Time and Frequency.
    [Show full text]
  • A Turbo-Brayton Cryocooler for Future European Observation Satellite Generation
    C19_078 1 A Turbo-Brayton Cryocooler for Future European Observation Satellite Generation J. Tanchon1, J. Lacapere1, A. Molyneaux2, M. Harris2, S. Hill2, S.M. Abu-Sharkh2, T. Tirolien3 1Absolut System SAS, Seyssinet-Pariset, France 2Ofttech, Gloucester, United Kingdom 3European Space Agency, Noordwijk, The Netherlands ABSTRACT Several types of active cryocoolers have been developed for space and military applications in the last ten years. Performances and reliability continuously increase to follow the requirements evolution of new generations of satellite: less power consumption, more cooling capacity, increased life duration. However, in addition to this increase of performances and reliability, the microvibrations re- quirement becomes critical. In fact, with the development of vibration-free technologies, classical Earth Observation cryocoolers (Stirling, Pulse Tube) will become the main source of microvibra- tions on-board the satellite. A new generation cryocooler is being developed at Absolut System using very high speed turbomachines in order to avoid any generated perturbations below 1000 Hz. This development is performed in the frame of ESA Technical Research Program - 4000113495/15/NL/KML. This paper presents the status of this development project based on Reverse Brayton cycle with very high speed turbomachines. INTRODUCTION The space cryogenics sector is characterized by a large number of applications (detection, im- aging, sample conservation, propulsion, telecommunications etc.) that lead to various requirements (temperature range, microvibration, lifetime, power consumption etc.) that can be met by different solutions (Stirling or JT coolers, mechanical or sorption compressors etc.). The recent years saw, in Europe, the developments of coolers to meet Earth Observation mission UHTXLUHPHQWVWKDWDUHFDSDEOHWRSURYLGHVLJQL¿FDQWFRROLQJSRZHUDWDQRSHUDWLRQDOWHPSHUDWXUH around 50K (for IR detection).
    [Show full text]
  • First and Second Law Evaluation of Combined Brayton-Organic Rankine Power Cycle
    Journal of Thermal Engineering, Vol. 6, No. 4, pp. 577-591, July, 2020 Yildiz Technical University Press, Istanbul, Turkey FIRST AND SECOND LAW EVALUATION OF COMBINED BRAYTON-ORGANIC RANKINE POWER CYCLE Önder Kaşka1, Onur Bor2, Nehir Tokgöz3* Muhammed Murat Aksoy4 ABSTRACT In the present work, we have conducted thermodynamic analysis of an organic Rankine cycle (ORC) using waste heat from intercooler and regenerator in Brayton cycle with intercooling, reheating, and regeneration (BCIRR). First of all, the first law analysis is used in this combined cycle. Several outputs are revealed in this study such as the cycle efficiencies in Brayton cycle which is dependent on turbine inlet temperature, intercooler pressure ratios, and pinch point temperature difference. For all cycles, produced net power is increased because of increasing turbine inlet temperature. Since heat input to the cycles takes place at high temperatures, the produced net power is increased because of increasing turbine inlet temperature for all cycles. The thermal efficiency of combined cycle is higher about 11.7% than thermal efficiency of Brayton cycle alone. Moreover, the net power produced by ORC has contributed nearly 28650 kW. The percentage losses of exergy for pump, turbine, condenser, preheater I, preheater II, and evaporator are 0.33%, 33%, 22%, 23%, 6%, and16% respectively. The differences of pinch point temperature on ORC net power and efficiencies of ORC are investigated. In addition, exergy efficiencies of components with respect to intercooling pressure ratio and evaporator effectiveness is presented. Exergy destructions are calculated for all the components in ORC. Keywords: Brayton Cycle, Organic Rankine Cycle, Bottoming Cycle, Pinch Point Temperature, Waste Heat, Energy and Exergy Analysis INTRODUCTION Thermal energy systems as well as corresponding all parts have been challenged to improve overall efficiency due to lack of conventional fuels, reduce climate change and so on for recent years.
    [Show full text]
  • Recording and Evaluating the Pv Diagram with CASSY
    LD Heat Physics Thermodynamic cycle Leaflets P2.6.2.4 Hot-air engine: quantitative experiments The hot-air engine as a heat engine: Recording and evaluating the pV diagram with CASSY Objects of the experiment Recording the pV diagram for different heating voltages. Determining the mechanical work per revolution from the enclosed area. Principles The cycle of a heat engine is frequently represented as a closed curve in a pV diagram (p: pressure, V: volume). Here the mechanical work taken from the system is given by the en- closed area: W = − ͛ p ⋅ dV (I) The cycle of the hot-air engine is often described in an idealised form as a Stirling cycle (see Fig. 1), i.e., a succession of isochoric heating (a), isothermal expansion (b), isochoric cooling (c) and isothermal compression (d). This description, however, is a rough approximation because the working piston moves sinusoidally and therefore an isochoric change of state cannot be expected. In this experiment, the pV diagram is recorded with the computer-assisted data acquisition system CASSY for comparison with the real behaviour of the hot-air engine. A pressure sensor measures the pressure p in the cylinder and a displacement sensor measures the position s of the working piston, from which the volume V is calculated. The measured values are immediately displayed on the monitor in a pV diagram. Fig. 1 pV diagram of the Stirling cycle 0210-Wei 1 P2.6.2.4 LD Physics Leaflets Setup Apparatus The experimental setup is illustrated in Fig. 2. 1 hot-air engine . 388 182 1 U-core with yoke .
    [Show full text]
  • Novel Hot Air Engine and Its Mathematical Model – Experimental Measurements and Numerical Analysis
    POLLACK PERIODICA An International Journal for Engineering and Information Sciences DOI: 10.1556/606.2019.14.1.5 Vol. 14, No. 1, pp. 47–58 (2019) www.akademiai.com NOVEL HOT AIR ENGINE AND ITS MATHEMATICAL MODEL – EXPERIMENTAL MEASUREMENTS AND NUMERICAL ANALYSIS 1 Gyula KRAMER, 2 Gabor SZEPESI *, 3 Zoltán SIMÉNFALVI 1,2,3 Department of Chemical Machinery, Institute of Energy and Chemical Machinery University of Miskolc, Miskolc-Egyetemváros 3515, Hungary e-mail: [email protected], [email protected], [email protected] Received 11 December 2017; accepted 25 June 2018 Abstract: In the relevant literature there are many types of heat engines. One of those is the group of the so called hot air engines. This paper introduces their world, also introduces the new kind of machine that was developed and built at Department of Chemical Machinery, Institute of Energy and Chemical Machinery, University of Miskolc. Emphasizing the novelty of construction and the working principle are explained. Also the mathematical model of this new engine was prepared and compared to the real model of engine. Keywords: Hot, Air, Engine, Mathematical model 1. Introduction There are three types of volumetric heat engines: the internal combustion engines; steam engines; and hot air engines. The first one is well known, because it is on zenith nowadays. The steam machines are also well known, because their time has just passed, even the elder ones could see those in use. But the hot air engines are forgotten. Our aim is to consider that one. The history of hot air engines is 200 years old.
    [Show full text]
  • Design of a Cryogenic Turbine for a Hybrid Cryocooler
    Design of a Cryogenic Turbine for a Hybrid Cryocooler by Thomas L. Fraser A thesis submitted in partial fulfillment of the requirements for the degree of Master of Science (Mechanical Engineering) at the UNIVERISTY OF WISCONSIN-MADISON 2006 Approved by _____________________________________________ ______________ Professor Gregory F. Nellis Date i Abstract The hybrid pulse tube-reverse Brayton cycle cryocooler has the potential for cooling to temperatures on the order of 10 K. By using the rectifying interface which converts the oscillating pulse tube flow to continuous flow, both vibrations and low temperature regenerator losses are overcome, making the hybrid an ideal candidate for cooling infrared focal plane arrays which demand low temperature and low vibration. However, the turboexpander within the reverse Brayton cycle is complex and its performance is highly dependent on the performance of its subcomponents, thus necessitating a model predicting the turboexpander performance. A model was developed to predict the performance of the reverse Brayton cycle stage including the recuperative heat exchanger and turboexpander components. The turboexpander was numerically modeled in detail to include the sub-models of rotordynamics, the thermal and leakage performance of the seal, and the turboalternator. Where possible, the models were verified against either an analytical model or experimental data. A parametric analysis was carried out to determine the optimal design and conditions for the turboexpander. ii Acknowledgements First and foremost I would like to thank Greg Nellis. Besides being my advisor for this project he is also responsible for sparking an interest in energy science through his heat transfer courses I took as an undergrad.
    [Show full text]
  • Supercritical Carbon Dioxide(S-CO2) Power Cycle for Waste Heat Recovery: a Review from Thermodynamic Perspective
    processes Review Supercritical Carbon Dioxide(s-CO2) Power Cycle for Waste Heat Recovery: A Review from Thermodynamic Perspective Liuchen Liu, Qiguo Yang and Guomin Cui * School of Energy and Power Engineering, University of Shanghai for Science and Technology, Shanghai 200093, China; [email protected] (L.L.); [email protected] (Q.Y.) * Correspondence: [email protected] Received: 11 October 2020; Accepted: 13 November 2020; Published: 15 November 2020 Abstract: Supercritical CO2 power cycles have been deeply investigated in recent years. However, their potential in waste heat recovery is still largely unexplored. This paper presents a critical review of engineering background, technical challenges, and current advances of the s-CO2 cycle for waste heat recovery. Firstly, common barriers for the further promotion of waste heat recovery technology are discussed. Afterwards, the technical advantages of the s-CO2 cycle in solving the abovementioned problems are outlined by comparing several state-of-the-art thermodynamic cycles. On this basis, current research results in this field are reviewed for three main applications, namely the fuel cell, internal combustion engine, and gas turbine. For low temperature applications, the transcritical CO2 cycles can compete with other existing technologies, while supercritical CO2 cycles are more attractive for medium- and high temperature sources to replace steam Rankine cycles. Moreover, simple and regenerative configurations are more suitable for transcritical cycles, whereas various complex configurations have advantages for medium- and high temperature heat sources to form cogeneration system. Finally, from the viewpoints of in-depth research and engineering applications, several future development directions are put forward. This review hopes to promote the development of s-CO2 cycles for waste heat recovery.
    [Show full text]
  • Cryogenic Refrigeration Using an Acoustic Stirling Expander
    CRYOGENIC REFRIGERATION USING AN ACOUSTIC STIRLING EXPANDER Masters Thesis by Nick Emery Department of Mechanical Engineering, University of Canterbury Christchurch, New Zealand Abstract A single-stage pulse tube cryocooler was designed and fabricated to provide cooling at 50 K for a high temperature superconducting (HTS) magnet, with a nominal electrical input frequency of 50 Hz and a maximum mean helium working gas pressure of 2.5 MPa. Sage software was used for the thermodynamic design of the pulse tube, with an initially predicted 30 W of cooling power at 50 K, and an input indicated power of 1800 W. Sage was found to be a useful tool for the design, and although not perfect, some correlation was established. The fabricated pulse tube was closely coupled to a metallic diaphragm pressure wave generator (PWG) with a 60 ml swept volume. The pulse tube achieved a lowest no-load temperature of 55 K and provided 46 W of cooling power at 77 K with a p-V input power of 675 W, which corresponded to 19.5% of Carnot COP. Recommendations included achieving the specified displacement from the PWG under the higher gas pressures, design and development of a more practical co-axial pulse tube and a multi-stage configuration to achieve the power at lower temperatures required by HTS. ii Acknowledgements The author acknowledges: His employer, Industrial Research Ltd (IRL), New Zealand, for the continued support of this work, Alan Caughley for all his encouragement, help and guidance, New Zealand’s Foundation for Research, Science and Technology for funding, University of Canterbury – in particular Alan Tucker and Michael Gschwendtner for their excellent supervision and helpful input, David Gedeon for his Sage software and great support, Mace Engineering for their manufacturing assistance, my wife Robyn for her support, and HTS-110 for creating an opportunity and pathway for the commercialisation of the device.
    [Show full text]
  • Thermodynamic Analysis of an Irreversible Maisotsenko Reciprocating Brayton Cycle
    entropy Article Thermodynamic Analysis of an Irreversible Maisotsenko Reciprocating Brayton Cycle Fuli Zhu 1,2,3, Lingen Chen 1,2,3,* and Wenhua Wang 1,2,3 1 Institute of Thermal Science and Power Engineering, Naval University of Engineering, Wuhan 430033, China; [email protected] (F.Z.); [email protected] (W.W.) 2 Military Key Laboratory for Naval Ship Power Engineering, Naval University of Engineering, Wuhan 430033, China 3 College of Power Engineering, Naval University of Engineering, Wuhan 430033, China * Correspondence: [email protected] or [email protected]; Tel.: +86-27-8361-5046; Fax: +86-27-8363-8709 Received: 20 January 2018; Accepted: 2 March 2018; Published: 5 March 2018 Abstract: An irreversible Maisotsenko reciprocating Brayton cycle (MRBC) model is established using the finite time thermodynamic (FTT) theory and taking the heat transfer loss (HTL), piston friction loss (PFL), and internal irreversible losses (IILs) into consideration in this paper. A calculation flowchart of the power output (P) and efficiency (η) of the cycle is provided, and the effects of the mass flow rate (MFR) of the injection of water to the cycle and some other design parameters on the performance of cycle are analyzed by detailed numerical examples. Furthermore, the superiority of irreversible MRBC is verified as the cycle and is compared with the traditional irreversible reciprocating Brayton cycle (RBC). The results can provide certain theoretical guiding significance for the optimal design of practical Maisotsenko reciprocating gas turbine plants. Keywords: finite-time thermodynamics; irreversible Maisotsenko reciprocating Brayton cycle; power output; efficiency 1. Introduction The revolutionary Maisotsenko cycle (M-cycle), utilizing the psychrometric renewable energy from the latent heat of water evaporating, was firstly provided by Maisotsenko in 1976.
    [Show full text]
  • Gas Power Cycles
    Week 11 Gas Power Cycles ME 300 Thermodynamics II 1 Today’s Outline • Gas turbine engines • Brayton cycle • Analysis • Example ME 300 Thermodynamics II 2 Gas Turbine Engine • Produces shaft power by GE H series power generation gas turbine. This 480-megawatt unit has a rated thermal expanding high enthalpy gas efficiency of 60% in combined cycle through a turbine configurations. • A compressor and a combustor produce the enthalpy increasing pressure and temperature, resp. • The spinning turbine rotates a shaft which drives the compressor • Remaining enthalpy can be used to drive a generator or can be expanded in a nozzle producing kinetic energy e.g. thrust ME 300 Thermodynamics II 3 Enthalpy Generation and Conversion Turbine Fuel converts enthalpy Generator to shaft power for Compressor Combustor electricity increases increases pressure Temperature Air (pv) (u) Nozzle converts enthalpy into kinetic energy ME 300 Thermodynamics II 4 Gas Turbine Engine Components http://www.stanford.edu/group/ctr/ResBriefs/temp05/schluter2.pdf www.aem.umn.edu/research/Images/pw_GasTurbine.gif ME 300 Thermodynamics II 5 Combustor Simulations ME 300 Thermodynamics II 6 Schematic • Fresh air enters compressors ~constant pressure • Air compressed to high pressure in compressor e.g. 23:1 • High pressure air is mixed with injected fuel spray in combustor raising temperatures • High enthalpy product gases expand in turbine producing shaft work to run compressor or Open cycle generator ME 300 Thermodynamics II 7 Air Standard Brayton Cycle • Model as closed cycle
    [Show full text]
  • Comparison of ORC Turbine and Stirling Engine to Produce Electricity from Gasified Poultry Waste
    Sustainability 2014, 6, 5714-5729; doi:10.3390/su6095714 OPEN ACCESS sustainability ISSN 2071-1050 www.mdpi.com/journal/sustainability Article Comparison of ORC Turbine and Stirling Engine to Produce Electricity from Gasified Poultry Waste Franco Cotana 1,†, Antonio Messineo 2,†, Alessandro Petrozzi 1,†,*, Valentina Coccia 1, Gianluca Cavalaglio 1 and Andrea Aquino 1 1 CRB, Centro di Ricerca sulle Biomasse, Via Duranti sn, 06125 Perugia, Italy; E-Mails: [email protected] (F.C.); [email protected] (V.C.); [email protected] (G.C.); [email protected] (A.A.) 2 Università degli Studi di Enna “Kore” Cittadella Universitaria, 94100 Enna, Italy; E-Mail: [email protected] † These authors contributed equally to this work. * Author to whom correspondence should be addressed; E-Mail: [email protected]; Tel.: +39-075-585-3806; Fax: +39-075-515-3321. Received: 25 June 2014; in revised form: 5 August 2014 / Accepted: 12 August 2014 / Published: 28 August 2014 Abstract: The Biomass Research Centre, section of CIRIAF, has recently developed a biomass boiler (300 kW thermal powered), fed by the poultry manure collected in a nearby livestock. All the thermal requirements of the livestock will be covered by the heat produced by gas combustion in the gasifier boiler. Within the activities carried out by the research project ENERPOLL (Energy Valorization of Poultry Manure in a Thermal Power Plant), funded by the Italian Ministry of Agriculture and Forestry, this paper aims at studying an upgrade version of the existing thermal plant, investigating and analyzing the possible applications for electricity production recovering the exceeding thermal energy. A comparison of Organic Rankine Cycle turbines and Stirling engines, to produce electricity from gasified poultry waste, is proposed, evaluating technical and economic parameters, considering actual incentives on renewable produced electricity.
    [Show full text]
  • Chapter 9, Problem 16. an Air-Standard Cycle Is Executed in A
    COSMOS: Complete Online Solutions Manual Organization System Chapter 9, Problem 16. An air-standard cycle is executed in a closed system and is composed of the following four processes: 1-2 Isentropic compression from 100 kPa and 27°C to 1 MPa 2-3 P = constant heat addition in amount of 2800 kJ/kg 3-4 v = constant heat rejection to 100 kPa 4-1 P = constant heat rejection to initial state (a) Show the cycle on P-v and T-s diagrams. (b) Calculate the maximum temperature in the cycle. (c) Determine the thermal efficiency. Assume constant specific heats at room temperature. * Problems designated by a “C” are concept questions, and students are encouraged to answer them all. Problems designated by an “E” are in English units, and the SI users can ignore them. Problems with the are solved using EES, and complete solutions together with parametric studies are included on the enclosed DVD. Problems with the are comprehensive in nature and are intended to be solved with a computer, preferably using the EES software that accompanies this text. Thermodynamics: An Engineering Approach, 5/e, Yunus Çengel and Michael Boles, © 2006 The McGraw-Hill Companies. COSMOS: Complete Online Solutions Manual Organization System Chapter 9, Problem 37. The compression ratio of an air-standard Otto cycle is 9.5. Prior to the isentropic compression process, the air is at 100 kPa, 35°C, and 600 cm3. The temperature at the end of the isentropic expansion process is 800 K. Using specific heat values at room temperature, determine (a) the highest temperature and pressure in the cycle; (b) the amount of heat transferred in, in kJ; (c) the thermal efficiency; and (d) the mean effective pressure.
    [Show full text]