An Alternative Architecture of the Humphrey Cycle and the Effect of Fuel Type on Its Efficiency
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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. -
Basic Thermodynamics-17ME33.Pdf
Module -1 Fundamental Concepts & Definitions & Work and Heat MODULE 1 Fundamental Concepts & Definitions Thermodynamics definition and scope, Microscopic and Macroscopic approaches. Some practical applications of engineering thermodynamic Systems, Characteristics of system boundary and control surface, examples. Thermodynamic properties; definition and units, intensive and extensive properties. Thermodynamic state, state point, state diagram, path and process, quasi-static process, cyclic and non-cyclic processes. Thermodynamic equilibrium; definition, mechanical equilibrium; diathermic wall, thermal equilibrium, chemical equilibrium, Zeroth law of thermodynamics, Temperature; concepts, scales, fixed points and measurements. Work and Heat Mechanics, definition of work and its limitations. Thermodynamic definition of work; examples, sign convention. Displacement work; as a part of a system boundary, as a whole of a system boundary, expressions for displacement work in various processes through p-v diagrams. Shaft work; Electrical work. Other types of work. Heat; definition, units and sign convention. 10 Hours 1st Hour Brain storming session on subject topics Thermodynamics definition and scope, Microscopic and Macroscopic approaches. Some practical applications of engineering thermodynamic Systems 2nd Hour Characteristics of system boundary and control surface, examples. Thermodynamic properties; definition and units, intensive and extensive properties. 3rd Hour Thermodynamic state, state point, state diagram, path and process, quasi-static -
Thermodynamics the Goal of Thermodynamics Is to Understand How Heat Can Be Converted to Work
Thermodynamics The goal of thermodynamics is to understand how heat can be converted to work Main lesson: Not all the heat energy can be converted to mechanical energy This is because heat energy comes with disorder (entropy), and overall disorder cannot decrease Temperature v T Random directions of velocity Higher temperature means higher velocities v Add up energy of all molecules: Internal Energy of gas U Mechanical energy: all atoms move in the same direction 1 Mv2 2 Statistical mechanics For one atom 1 1 1 1 1 1 3 E = mv2 + mv2 + mv2 = kT + kT + kT = kT h i h2 xi h2 yi h2 z i 2 2 2 2 Ideal gas: No Potential energy from attraction between atoms 3 U = NkT h i 2 v T Pressure v Pressure is caused because atoms T bounce off the wall Lx p − x px ∆px =2px 2L ∆t = x vx ∆p 2mv2 mv2 F = x = x = x ∆t 2Lx Lx ∆p 2mv2 mv2 F = x = x = x ∆t 2Lx Lx 1 mv2 =2 kT = kT h xi ⇥ 2 kT F = Lx Pressure v F kT 1 kT A = LyLz P = = = A Lx LyLz V NkT Many particles P = V Lx PV = NkT Volume V = LxLyLz Work Lx ∆V = A ∆Lx v A = LyLz Work done BY the gas ∆W = F ∆Lx We can write this as ∆W =(PA) ∆Lx = P ∆V This is useful because the body could have a generic shape Internal energy of gas decreases U U ∆W ! − Gas expands, work is done BY the gas P dW = P dV Work done is Area under curve V P Gas is pushed in, work is done ON the gas dW = P dV − Work done is negative of Area under curve V By convention, we use POSITIVE sign for work done BY the gas Getting work from Heat Gas expands, work is done BY the gas P dW = P dV V Volume in increases Internal energy decreases .. -
25 Kw Low-Temperature Stirling Engine for Heat Recovery, Solar, and Biomass Applications
25 kW Low-Temperature Stirling Engine for Heat Recovery, Solar, and Biomass Applications Lee SMITHa, Brian NUELa, Samuel P WEAVERa,*, Stefan BERKOWERa, Samuel C WEAVERb, Bill GROSSc aCool Energy, Inc, 5541 Central Avenue, Boulder CO 80301 bProton Power, Inc, 487 Sam Rayburn Parkway, Lenoir City TN 37771 cIdealab, 130 W. Union St, Pasadena CA 91103 *Corresponding author: [email protected] Keywords: Stirling engine, waste heat recovery, concentrating solar power, biomass power generation, low-temperature power generation, distributed generation ABSTRACT This paper covers the design, performance optimization, build, and test of a 25 kW Stirling engine that has demonstrated > 60% of the Carnot limit for thermal to electrical conversion efficiency at test conditions of 329 °C hot side temperature and 19 °C rejection temperature. These results were enabled by an engine design and construction that has minimal pressure drop in the gas flow path, thermal conduction losses that are limited by design, and which employs a novel rotary drive mechanism. Features of this engine design include high-surface- area heat exchangers, nitrogen as the working fluid, a single-acting alpha configuration, and a design target for operation between 150 °C and 400 °C. 1 1. INTRODUCTION Since 2006, Cool Energy, Inc. (CEI) has designed, fabricated, and tested five generations of low-temperature (150 °C to 400 °C) Stirling engines that drive internally integrated electric alternators. The fifth generation of engine built by Cool Energy is rated at 25 kW of electrical power output, and is trade-named the ThermoHeart® Engine. Sources of low-to-medium temperature thermal energy, such as internal combustion engine exhaust, industrial waste heat, flared gas, and small-scale solar heat, have relatively few methods available for conversion into more valuable electrical energy, and the thermal energy is usually wasted. -
Supercritical CO 2 Cycles for Gas Turbine
Power Gen International December 8-10, Las Vegas, Nevada SUPERCRITICAL CO2 CYCLES FOR GAS TURBINE COMBINED CYCLE POWER PLANTS Timothy J. Held Chief Technology Officer Echogen Power Systems, LLC Akron, Ohio [email protected] ABSTRACT Supercritical carbon dioxide (sCO2) used as the working fluid in closed loop power conversion cycles offers significant advantages over steam and organic fluid based Rankine cycles. Echogen Power Systems LLC has developed several variants of sCO2 cycles that are optimized for bottoming and heat recovery applications. In contrast to cycles used in previous nuclear and CSP studies, these cycles are highly effective in extracting heat from a sensible thermal source such as gas turbine exhaust or industrial process waste heat, and then converting it to power. In this study, conceptual designs of sCO2 heat recovery systems are developed for gas turbine combined cycle (GTCC) power generation over a broad range of system sizes, ranging from distributed generation (~5MW) to utility scale (> 500MW). Advanced cycle simulation tools employing non-linear multivariate constrained optimization processes are combined with system and plant cost models to generate families of designs with different cycle topologies. The recently introduced EPS100 [1], the first commercial-scale sCO2 heat recovery engine, is used to validate the results of the cost and performance models. The results of the simulation process are shown as system installed cost as a function of power, which allows objective comparisons between different cycle architectures, and to other power generation technologies. Comparable system cost and performance studies for conventional steam-based GTCC are presented on the basis of GT-Pro™ simulations [2]. -
Removing the Mystery of Entropy and Thermodynamics – Part II Harvey S
Table IV. Example of audit of energy loss in collision (with a mass attached to the end of the spring). Removing the Mystery of Entropy and Thermodynamics – Part II Harvey S. Leff, Reed College, Portland, ORa,b Part II of this five-part series is focused on further clarification of entropy and thermodynamics. We emphasize that entropy is a state function with a numerical value for any substance in thermodynamic equilibrium with its surroundings. The inter- pretation of entropy as a “spreading function” is suggested by the Clausius algorithm. The Mayer-Joule principle is shown to be helpful in understanding entropy changes for pure work processes. Furthermore, the entropy change when a gas expands or is compressed, and when two gases are mixed, can be understood qualitatively in terms of spatial energy spreading. The question- answer format of Part I1 is continued, enumerating main results in Key Points 2.1-2.6. • What is the significance of entropy being a state Although the linear correlation in Fig. 1 is quite striking, the function? two points to be emphasized here are: (i) the entropy value In Part I, we showed that the entropy of a room temperature of each solid is dependent on the energy added to and stored solid can be calculated at standard temperature and pressure by it, and (ii) the amount of energy needed for the heating using heat capacity data from near absolute zero, denoted by T process from T = 0 + K to T = 298.15 K differs from solid to = 0+, to room temperature, Tf = 298.15 K. -
Ch 19. the First Law of Thermodynamics
Ch 19. The First Law of Thermodynamics Liu UCD Phy9B 07 1 19-1. Thermodynamic Systems Thermodynamic system: A system that can interact (and exchange energy) with its surroundings Thermodynamic process: A process in which there are changes in the state of a thermodynamic system Heat Q added to the system Q>0 taken away from the system Q<0 (through conduction, convection, radiation) Work done by the system onto its surroundings W>0 done by the surrounding onto the system W<0 Energy change of the system is Q + (-W) or Q-W Gaining energy: +; Losing energy: - Liu UCD Phy9B 07 2 19-2. Work Done During Volume Changes Area: A Pressure: p Force exerted on the piston: F=pA Infinitesimal work done by system dW=Fdx=pAdx=pdV V Work done in a finite volume change W = final pdV ∫V initial Liu UCD Phy9B 07 3 Graphical View of Work Gas expands Gas compresses Constant p dV>0, W>0 dV<0, W<0 W=p(V2-V1) Liu UCD Phy9B 07 4 19-3. Paths Between Thermodynamic States Path: a series of intermediate states between initial state (p1, V1) and a final state (p2, V2) The path between two states is NOT unique. V2 W= p1(V2-V1) +0 W=0+ p2(V2-V1) W = pdV ∫V 1 Work done by the system is path-dependent. Liu UCD Phy9B 07 5 Path Dependence of Heat Transfer Isotherml: Keep temperature const. Insulation + Free expansion (uncontrolled expansion of a gas into vacuum) Heat transfer depends on the initial & final states, also on the path. -
Investigation of Various Novel Air-Breathing Propulsion Systems
Investigation of Various Novel Air-Breathing Propulsion Systems A thesis submitted to the Graduate School of the University of Cincinnati in partial fulfillment of the requirements for the degree of MASTER OF SCIENCE in the Department of Aerospace Engineering & Engineering Mechanics of the College of Engineering and Applied Science 2016 by Jarred M. Wilhite B.S. Aerospace Engineering & Engineering Mechanics University of Cincinnati 2016 Committee Chair: Dr. Ephraim Gutmark Committee Members: Dr. Paul Orkwis & Dr. Mark Turner Abstract The current research investigates the operation and performance of various air-breathing propulsion systems, which are capable of utilizing different types of fuel. This study first focuses on a modular RDE configuration, which was mainly studied to determine which conditions yield stable, continuous rotating detonation for an ethylene-air mixture. The performance of this RDE was analyzed by studying various parameters such as mass flow rate, equivalence ratios, wave speed and cell size. For relatively low mass flow rates near stoichiometric conditions, a rotating detonation wave is observed for an ethylene-RDE, but at speeds less than an ideal detonation wave. The current research also involves investigating the newly designed, Twin Oxidizer Injection Capable (TOXIC) RDE. Mixtures of hydrogen and air were utilized for this configuration, resulting in sustained rotating detonation for various mass flow rates and equivalence ratios. A thrust stand was also developed to observe and further measure the performance of the TOXIC RDE. Further analysis was conducted to accurately model and simulate the response of thrust stand during operation of the RDE. Also included in this research are findings and analysis of a propulsion system capable of operating on the Inverse Brayton Cycle. -
“Fabrication of Stirling Engine”
“Fabrication of Stirling Engine” Sibabrata Mohanty*,Debasis Pattnayak** , Ashik Dash*** ,Raju Singh**** , Chandrakant Bhardwaj***** , Sk Firdosh Akhtar****** *Assistant Professor, Department of Mechanical Engineering, Gandhi Institute of Engineering and Technology, Gunupur, Rayagada Odisha, **,***,****,*****,&****** B.Tech Mechanical Students, Gandhi Institute of Engineering and Technology, Gunupur, Rayagada Odisha ABSTRACT The performance of Stirling engines meets the demands of the efficient use of energy and environmental security and therefore they are the subject of much current interest. Hence, the development and investigation of Stirling engine have come to the attention of many scientific institutes and commercial companies. The Stirling engine is both practically and theoretically a significant device, its practical virtue is simple, reliable and safe which was recognized for a full century following its invention by Robert Stirling in 1816. The engine operates on a closed thermodynamic cycle, which is reversible. The objective of this project paper is to provide fundamental information and present a detailed review of the efforts taken by us for the development of the Stirling cycle engine and techniques used for engine analysis. A number of attempts have been made by us to build and improve the performance of Stirling engines. It is seen that for successful operation of engine system with good efficiency a careful design, proper selection of drive mechanism and engine configuration is essential. This project paper indicates that a Stirling cycle engine working with relatively low temperature with air or helium as working fluid is potentially attractive engines of the future, especially solar-powered low-temperature differential Stirling engines. Keywords: Stirling engines, Stirling cycle, thermodynamic cycle 1. -
Thermodynamic Cycle
INTERNATIONAL JOURNAL OF ENVIRONMENTAL & SCIENCE EDUCATION 2016, VOL. 11, NO. 12, 5009-5019 OPEN ACCESS Detonation Jet Engine. Part 1 – Thermodynamic Cycle Pavel V. Bulata and Konstantin N. Volkovb aSaint Petersburg National Research University of Information Technologies, Mechanics and Optics, Saint Petersburg, RUSSIA; bKingston University, Faculty of Science, Engineering and Computing, London, UK ABSTRACT We present the most relevant works on jet engine design that utilize thermodynamic cycle of detonative combustion. The efficiency advantages of thermodynamic detonative combustion cycle over Humphrey combustion cycle at constant volume and Brayton combustion cycle at constant pressure were demonstrated. An ideal Ficket-Jacobs detonation cycle, and the thermodynamic cycle of real detonation engine that utilizes over compressed detonation were discussed. Main trends in development of detonation engines were described. Relevant for nearest time problems and directions of research were formulated. KEYWORDS ARTICLE HISTORY Detonation, detonation wave, detonation engine, Received 13 April 2016 rotational detonation engine, pulse detonation Revised 17 May 2016 engine Accepted 22 May 2016 Introduction Historically the most important investment into the development of detonative combustion was made by Soviet and then Russian scientists. Ya.B. Zeldovich (1940) was the first who proposed to utilize detonation in engines and energy devices. By examining problem of arbitrary discontinuity breakdown in reacting medium, G.M. Bam-Zelikovich (1949; 1952) has laid the theoretical foundation of pulse detonation engine. He also was the first to give a simple theoretical explanation of pulsation appearance during fuel mixture combustion in cylindrical channel. Later, works were carried out in laboratory of gas- dynamics at Central Institute of Aviation Motors, under the direction of L.I. -
Chapter 20 -- Thermodynamics
ChapterChapter 2020 -- ThermodynamicsThermodynamics AA PowerPointPowerPoint PresentationPresentation byby PaulPaul E.E. TippensTippens,, ProfessorProfessor ofof PhysicsPhysics SouthernSouthern PolytechnicPolytechnic StateState UniversityUniversity © 2007 THERMODYNAMICSTHERMODYNAMICS ThermodynamicsThermodynamics isis thethe studystudy ofof energyenergy relationshipsrelationships thatthat involveinvolve heat,heat, mechanicalmechanical work,work, andand otherother aspectsaspects ofof energyenergy andand heatheat transfer.transfer. Central Heating Objectives:Objectives: AfterAfter finishingfinishing thisthis unit,unit, youyou shouldshould bebe ableable to:to: •• StateState andand applyapply thethe first andand second laws ofof thermodynamics. •• DemonstrateDemonstrate youryour understandingunderstanding ofof adiabatic, isochoric, isothermal, and isobaric processes.processes. •• WriteWrite andand applyapply aa relationshiprelationship forfor determiningdetermining thethe ideal efficiency ofof aa heatheat engine.engine. •• WriteWrite andand applyapply aa relationshiprelationship forfor determiningdetermining coefficient of performance forfor aa refrigeratior.refrigeratior. AA THERMODYNAMICTHERMODYNAMIC SYSTEMSYSTEM •• AA systemsystem isis aa closedclosed environmentenvironment inin whichwhich heatheat transfertransfer cancan taketake place.place. (For(For example,example, thethe gas,gas, walls,walls, andand cylindercylinder ofof anan automobileautomobile engine.)engine.) WorkWork donedone onon gasgas oror workwork donedone byby gasgas INTERNALINTERNAL -
Comprehensive Thermodynamic Analysis of the Humphrey Cycle for Gas Turbines with Pressure Gain Combustion
energies Article Comprehensive Thermodynamic Analysis of the Humphrey Cycle for Gas Turbines with Pressure Gain Combustion Panagiotis Stathopoulos Chair of Unsteady Thermodynamics in Gas Turbine Processes, Hermann Föttinger Institute, Technische Universität Berlin, Müller Breslau Str. 8, 10623 Berlin, Germany; [email protected]; Tel.: +49-30-314-29361 Received: 20 November 2018; Accepted: 11 December 2018; Published: 18 December 2018 Abstract: Conventional gas turbines are approaching their efficiency limits and performance gains are becoming increasingly difficult to achieve. Pressure Gain Combustion (PGC) has emerged as a very promising technology in this respect, due to the higher thermal efficiency of the respective ideal gas turbine thermodynamic cycles. Up to date, only very simplified models of open cycle gas turbines with pressure gain combustion have been considered. However, the integration of a fundamentally different combustion technology will be inherently connected with additional losses. Entropy generation in the combustion process, combustor inlet pressure loss (a central issue for pressure gain combustors), and the impact of PGC on the secondary air system (especially blade cooling) are all very important parameters that have been neglected. The current work uses the Humphrey cycle in an attempt to address all these issues in order to provide gas turbine component designers with benchmark efficiency values for individual components of gas turbines with PGC. The analysis concludes with some recommendations for the best strategy to integrate turbine expanders with PGC combustors. This is done from a purely thermodynamic point of view, again with the goal to deliver design benchmark values for a more realistic interpretation of the cycle. Keywords: pressure gain combustion; gas turbine; Humphrey cycle; thermodynamic analysis; turbine cooling; turbine integration 1.