DOCSLIB.ORG

Heat Engines and Refrigerators

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Heat Engines and Refrigerators Heat Engines and Refrigerators Ron Reifenberger Birck Nanotechnology Center Purdue University February 27, 2013 Exam II will be held on Tuesday April 30, 2013 TIME: 8:00-10:00 AM PLACE: ARMS 1021 Lecture 8 1 DEFINITION Any device that has the primary purpose to convert heat to work is called a Heat Engine. First, a quick review of different types of heat engines 2 Basic Idea ABCD Mass = m h gas Apply Heat! Remove Schematic: Heat! Qin C P B D PdV mgh A Qout V 3 EXAMPLE I: Early heat engines were steam engines (Savery in 1698, Newcomen in 1705, Watt in 1770) Simplified Steam Engine* Mechanical Piston Linkage Turning Steam wheel Boiler Water Cold Condenser 4 * REQUIRED A LICENSED OPERATING ENGINEER Modern steam engine (Work comes from decrease of Eint of steam) High pressure Low pressure flywheel Steam condenses Clean water to water at low is recycled! pressure (invented ~1865) An example of an external combustion engine Earliest steam engines were ~1% efficient (they burned enormous amounts of fuel!); by early 1900’s efficiencies reached ~10%; modern steam engines have efficiencies above 30%. 5 Classic Heat Engines • Rankine (steam) engine – 1859 (theory) 1st generation • Stirling engine - 1816 • Internal Combustion (Otto) engine - 1876 2nd generation • Diesel engine - 1893 6 Steam (Rankine) Cycle change water to steam Isentropic (constant entropy) expansion change steam Eint = 0 to water Isentropic Why? compression isentropic = quasistatic plus adiabatic7 Example II: The Stirling Engine (Invented by Robert Sterling in 1816) cooling fins two pistons Heat Heat Heat Heat Characteristics: Recycles same trapped gas, quiet, low vibration, higher efficiency (~40%) than steam engine or internal combustion engine, low power applications. http://en.wikipedia.org/wiki/Stirling_engine8 Moveable gas tight piston Simplified Stirling Engine 3 Flywheel not shown 2 4 Moveable 1 5 (or 1) displacer Cold Cold Cold Cold Cold w. shaft Loose- fitting P displacer (takes up P P space) P P Tube, open at top end, Hot Hot Hot Hot Hot closed at bottom end Expansion Compression caused by caused by thermal downward 9 expansion of motion of gas red piston Stirling Thermodynamic Cycle Qin isothermal process Eint = 0 Why? Qout 10 A commercial Stirling Engine Floor model Table model "The Lake Breeze Motor“ was marketed in 1919. Its original price was ~$25. It functions as a hot-air engine. A hot-air engine is a heat engine that uses the expansion and contraction of air under the influence of a temperature change to convert thermal energy into mechanical work. When you light the wick in the kerosene lamp, the hot air pushes through a turbine that then turns a shaft that ultimately turns the fan. Popular11 before the electrification of rural America which commenced in the mid 1930s. Example III: Second generation heat engines - Internal Combustion; William Barnet (1838) (takes advantage of the energy content of fossil fuels) How is heat derived from fuel? Through two basic chemical reactions: C + O2 CO2 + heat energy Exothermic or reactions: heat of O + H2 H2O + heat energy combustion Example: The reaction of a hydrocarbon heptane with oxygen 6 C7H16 + 11O2 7CO2 + 8H2O + 4.8 x 10 J (per 100 gm of C7H16) 12 Internal Combustion Engine (enabled by the extraction of petroleum from the earth by Drake in 1859) converts ~20% of chemical energy to mechanical energy Characteristics: • undesirable exhaust gas, • noisy, ~70 atm. gas pressure exerts • high vibration, force on piston • high power Compression to 6-10 atmospheres T ~ 1000 C 13 The Otto Thermodynamic Cycle (close approximation to the internal combustion engine) burning gasoline adiabatic process – rapid expansion Eint = 0 Why? adiabatic exhaust to process – rapid environment compression 14 Example IV: Diesel Engines Rudolf Diesel (1893) 6135H (6 cylinder, 13.5L, Turbocharged and Aftercooled) Tier 3 engine at 448kW @ 2100rpm (rated speed), BTE (brake thermal efficiency) is around 39% +/- 0.6%. 4024T (4 cylinder, 2.4L, Turbocharged) Tier 2 engine at 49kW @ 2800rpm,15 BTE is about 32%. The Wartsila-Sulzer RTA96-C turbocharged two-stroke diesel engine is the most powerful and most efficient prime-mover in the world today (12 cylinder version) Cylinder diameter 38 “ • Length 89 ft ; Width 44 ft • Max. Power 108,920 hp at 102 rpm •. At maximum economy, the engine exceeds 50% thermal efficiency. One piston and rod • Consumes 1,660 gallons of heavy fuel oil per hour 16 Internal Combustion Engines If an automobile engine (gasoline) were an ideal engine, it would have an efficiency of ~55%. Its actual efficiency is probably closer to 25%. A considerable amount of heat input is lost to the environment and NOT converted to work. Diesel engines have a slightly higher efficiency than gasoline engines. Diesels do not mix fuel with air and do not require electric spark ignition. The combustion occurs because a high temperature is reached upon compression. The efficiency of a diesel engine is ~30%. 17 Schematic Representation of Generic Heat Engine W = Qh -Qc Every heat engine transfers some fraction of heat energy from a hot reservoir to the surroundings (i.e. a cold reservoir). 18 Efficiency of Engine Efficiency = work done/energy in Don’t worry about previous sign conventions for Q (Qc is inherently negative; origin of minus sign?). Treat all Q’s as positive numbers! The proper definition of efficiency is important for historical reasons. It showed that the efficiency of an engine does NOT depend on the type of fuel, the pressure of the gas, the volume of the piston, etc. 19 Rate of heat transfer Rate of heat transfer: For a heat engine with ε =0.25, for every watt W = Qh -Qc (1W=1 J/s) of power generated by the engine, heat is removed from the hot reservoir at a rate of 4 watts (Qh) and heat is exhausted to the cold reservoir at a rate of 3 watts (Qc). 1 horsepower = 745.7 watts 20 Typical efficiencies: Liquid fuel rocket ~0.48 Steam turbine ~0.46 Diesel engine ~0.37 Automobile engine ~0.25 Steam locomotive ~0.08 21 Example During one cycle, an engine extracts 2 x 103 J of energy from a hot reservoir and transfers 1.5 x 103 J of energy to a cold reservoir. a) What is efficiency of engine? Q = 1 -c = 1 – 0.75 = 0.25 Qh b) How much work is done in one cycle? W = Qh-Qc = 500 J c) How much power is delivered if one cycle takes 0.4 s? W P = = 1250 W t 22 KEY IDEA: Knowing the shape and parameters of a thermodynamic cycle, it is possible to calculate the efficiency of a thermodynamic process SIMPLE EXAMPLE Take 1 mole of ideal gas quasistatically through the Useful factors: reversible process shown below: 101.3 J= 1 ℓ•atm R=8.206 x 10-2 ℓ•atm/(mol•K) P (in atm) PTVPV/T 23 2 1 1 atm 300K 24.6 ℓ 0.082 2 2 atm 600K 24.6 ℓ 0.082 1 1 4 3 2 atm 1200K 49.2 ℓ 0.082 1 atm 600K 49.2 ℓ 0.082 V (in ℓ) 4 24.6 49.2 23 See Tipler and Mosa: Prob. 19:25 W1 2: PΔV=0 Q1 2: ΔEint=CVΔT=1.5nRΔT=3.74 kJ W2 3: PΔV=4.99 kJ Q2 3: CPΔT=2.5nRΔT=12.5 kJ W3 4: PΔV=0 Q3 4: ΔEint=CVΔT=1.5nRΔT=-7.48 kJ W4 1: PΔV=-2.49 kJ Q4 1: CPΔT=2.5nRΔT=-6.24 kJ WkJkJkJWW 4.99 ( 2.49 ) 2.5 23 41 15.4% QQin 12 Q 23 3.74 kJkJ 12.5 16.24 kJ 24 Note that W= Qhc - Q (3.74 12.5) (7.48 6.24) 2.5kJ 4. High pressure liquid Refrigeration expands (and cools) through high-pressure expansion valve and returns to cooling coil 1. Refrigerant 3. Since temperature absorbs heat of compressed gas is and goes from higher than room liquid to gas temperature, heat is given off. Gas then condenses to a liquid under high pressure 2. Compressor increases pressure (and raises temperature) of gas 25 A refrigerator is a heat engine running backwards Q COP = c W Typical refrigerators have a COP 5 - 6 Rate of heat transfer: For a refrigerator with a COP = 5, for every watt of power used by the compressor (1W=1J/s), heat is removed from the cold reservoir at a rate of 5 watts (Q ) and heat is nd c The 2 Law of exhausted to the hot reservoir at Thermodynamics requires a rate of 6 watts (Qh). a COP < ∞ 26 After a party, 2 L (0.002 m3) of beer is placed in a refrigerator. The beer initially is at 323 K and is cooled to 283 K. If the COP of the fridge is 5, how much energy is needed to cool the beer? Assume beer is mostly water: c = 4190 J/(kg K); = 1 x 103 kg/m3 m = V = 2.0 kg 5 Qc = mcT = -3.35 x 10 J (heat flows out) Q 3.35 x 105 J COP = c = = 5 W = 6.7 x 104 J W W 27 Why can’t ε=1? Mass = m h W= Q–q=mgh gas n,T,V Apply T+ΔT, V+ΔV Heat! Q some heat q is always deposited in the gas: q=nCp ΔT =W/Q=(Q-q)/Q =1-[q/Q] < 1 since q>0 28.
Load more

Recommended publications
  • 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]
  • Arxiv:2003.07157V1 [Cond-Mat.Stat-Mech] 10 Mar 2020 Oin Ti on Htteiiilvlmso H Odadho Engine
    Stirling engine operating at low temperature difference Alejandro Romanelli∗ Instituto de F´ısica, Facultad de Ingenier´ıa Universidad de la Rep´ublica C.C. 30, C.P. 11000, Montevideo, Uruguay (Dated: March 17, 2020) Abstract The paper develops the dynamics and thermodynamics of Stirling engines that run with tem- perature differences below 100 0C. The working gas pressure is analytically expressed using an alternative thermodynamic cycle. The shaft dynamics is studied using its rotational equation of motion. It is found that the initial volumes of the cold and hot working gas play a non-negligible role in the functioning of the engine. arXiv:2003.07157v1 [cond-mat.stat-mech] 10 Mar 2020 1 I. INTRODUCTION In the field of energy efficiency, the use of waste energy is one of the keys to improve the performance of facilities, whether industrial or domestic. In general the waste energy arises as heat, from some thermal process, that it is necessary to remove. Therefore the use of the waste energy is usually conditioned by the difficulty of converting heat into other forms of energy.1,2 The Stirling engines, being external combustion machines, have the potential to take advantage of any source of thermal energy to convert it into mechanical energy. This makes them candidates to be used in heat recovery systems. The Stirling engine is essentially a two-part hot-air engine which operates in a closed regenerative thermodynamic cycle, with cyclic compressions and expansions of the working fluid at different temperature levels.3,4 The flow of the working fluid is controlled only by the internal volume changes; there are no valves and there is a net conversion of heat into work or vice-versa.
    [Show full text]
  • Gamma-Type Stirling Engine Prototype
    MODELLING AND OPTIMIZATION OF HIGH TEMPERATURE DIFFERENCE (HTD) GAMMA- TYPE STIRLING ENGINE PROTOTYPE By Suliman Alfarawi A thesis submitted to the University of Birmingham for the Degree of Doctor of Philosophy School of Mechanical Engineering College of Engineering and Physical Sciences The University of Birmingham September - 2017 University of Birmingham Research Archive e-theses repository This unpublished thesis/dissertation is copyright of the author and/or third parties. The intellectual property rights of the author or third parties in respect of this work are as defined by The Copyright Designs and Patents Act 1988 or as modified by any successor legislation. Any use made of information contained in this thesis/dissertation must be in accordance with that legislation and must be properly acknowledged. Further distribution or reproduction in any format is prohibited without the permission of the copyright holder. ABSTRACT Finding solutions for increasing energy demands is being globally pursued. One of the promising solutions is the utilization of renewable forms of energy with thermo-mechanical conversion systems such as Stirling engines. Nowadays, effort is made in industry and academia to promote the development of Stirling technology. In this context, this thesis was first focused on modelling of High Temperature Difference (HTD) gamma-type Stirling engine prototype (ST05-CNC) and investigating means of improving its performance. Secondly, newly parallel- geometry mini-channel regenerators (with hydraulic diameters of 0.5, 1, 1.5 mm) and their test facility were developed and fabricated to enhance engine performance. Both thermodynamic and CFD models were comprehensively developed to simulate the engine and have been successfully validated against experimental data.
    [Show full text]
  • Stirling Engine)
    Heat Cycles Hot air engine (Stirling engine) OPERATE A FUNCTIONAL MODEL OF A STIRLING ENGINE AS A HEAT ENGINE Operate the hot-air engine as a heat engine Demonstrate how thermal energy is converted into mechanical energy Measure the no-load speed as a function of the thermal power UE2060100 04/16 JS BASIC PRINCIPLES The thermodynamic cycle of the Stirling engine While the working piston is in its top dead centre posi- (invented by Rev. R. Stirling in 1816) can be pre- tion: the displacement piston retracts and air is dis- sented in a simplified manner as the processes placed towards the top end of the large cylinder so that thermal input, expansion, thermal output and com- it cools. pression. These processes have been illustrated by The cooled air is compressed by the working piston schematic diagrams (Fig. 1 to Fig. 4) for the func- extending. The mechanical work required for this is tional model used in the experiment. provided by the flywheel rod. A displacement piston P1 moves upwards and displac- If the Stirling engine is operated without any mechanical es the air downwards into the heated area of the large load, it operates with at a speed which is limited only by cylinder, thereby facilitating the input of air. During this internal friction and which depends on the input heating operation the working piston is at its bottom dead centre energy. The speed is reduced as soon as a load takes position since the displacement piston is ahead of the up some of the mechanical energy. This is most easily working piston by 90°.
    [Show full text]
  • HOT AIR ENGINE, DEVELOPED and PATENTED by TRAIAN VUIA, a ROMANIAN PERFORMANCE for 21St CENTURY
    HOT AIR ENGINE, DEVELOPED AND PATENTED BY TRAIAN VUIA, A ROMANIAN PERFORMANCE FOR 21st CENTURY DUMITRU MIHALCEA1 Abstract. After thoroughly researching data from national archives, libraries, and important technical studies from Romania and abroad, I concluded that the hot air and closed-circuit engine built, tested, and patented by Romanian engineer Traian Vuia (1872–1950), is superior in its thermodynamic performances to similar engines investigated today. For this engine, almost as perfect thermodynamic Carnot engine, Traian Vuia has achieved ten (10) patents, during 1908-1916 years. Therefore, this engine unjustified forgotten or ignored over a century should be considered a wealth, which belongs (inter) national technical heritage. It represents a great challenge to bring this engine back to the scientific and industrial circuit and, in order to do so, this paper clarifies the following issues: • How evolved over time thermal cycling of different engines, as target perfect thermodynamic engine Carnot; • Which was the thermal process used at Vuia engine for isothermation of compression and expansion; • Today “isodiabate heat release and receipt” at Vuia engine can be qualified as an isentropic process for ideal conditions or adiabatic process for real conditions, with irreversibility, or others; • Which device used Traian Vuia for “isodiabate heat release and receipt”; • Which is the construction and operation of Vuia engine; • If thermal cycle and engine Vuia has been recognized internationally. Key words: Carnot, Stirling, Ericsson, Joule, Brayton, engines, almost perfect thermo- dynamic engines Vuia and Pomojnicu, engines with external combustion, isothermate compression and expansion, isentropic, adiabatic, isodiabatic heat release and receipt, regenerator, recuperator. 1. INTRODUCTION At a time when the steam engine showed signs of technical ageing, causing numerous accidents due to explosion of boilers and high consumption of coal, experts turned their attention to regenerative engines with open or closed circuits, 1Corresponding address: str.
    [Show full text]
  • Beta Type Stirling Engine. Schmidt and Finite Physical Dimensions Thermodynamics Methods Faced to Experiments
    entropy Article Beta Type Stirling Engine. Schmidt and Finite Physical Dimensions Thermodynamics Methods Faced to Experiments Cătălina Dobre 1 , Lavinia Grosu 2, Monica Costea 1 and Mihaela Constantin 1,* 1 Department of Engineering Thermodynamics, Engines, Thermal and Refrigeration Equipments, University Politehnica of Bucharest, Splaiul Independent, ei 313, 060042 Bucharest, Romania; [email protected] (C.D.); [email protected] (M.C.) 2 Laboratory of Energy, Mechanics and Electromagnetic, Paris West Nanterre La Défense University, 50, Rue de Sèvres, 92410 Ville d’Avray, France; [email protected] * Correspondence: [email protected] Received: 10 September 2020; Accepted: 9 November 2020; Published: 11 November 2020 Abstract: The paper presents experimental tests and theoretical studies of a Stirling engine cycle applied to a β-type machine. The finite physical dimension thermodynamics (FPDT) method and 0D modeling by the imperfectly regenerated Schmidt model are used to develop analytical models for the Stirling engine cycle. The purpose of this study is to show that two simple models that take into account only the irreversibility due to temperature difference in the heat exchangers and imperfect regeneration are able to indicate engine behavior. The share of energy loss for each is determined using these two models as well as the experimental results of a particular engine. The energies exchanged by the working gas are expressed according to the practical parameters, which are necessary for the engineer during the entire project, namely the maximum pressure, the maximum volume, the compression ratio, the temperature of the heat sources, etc. The numerical model allows for evaluation of the energy processes according to the angle of the crankshaft (kinematic–thermodynamic coupling).
    [Show full text]
  • Determining the Efficiency of the Hot-Air Engine As a Refrigerator
    LD Heat Physics Thermodynamic cycle Leaflets P2.6.2.3 Hot-air engine: quantitative experiments Determining the efficiency of the hot-air engine as a refrigerator Objects of the experiments Measuring the heat Q2 extracted from the cylinder head during one revolution. Measuring the heat Q1 transferred to the cooling water during one revolution. Determining the efficiency ␩ of the refrigerator. Principles During one revolution, the hot-air engine, operated as a re- The efficiency is determined experimentally by driving the frigerator, extracts the heat Q2 from the cylinder head and flywheel of the hot-air engine with an electric motor at an transfers the heat Q1 to the cooling water. As heat is transferred angular speed f and determining the electric calorific power from the colder to the warmer reservoir, that is, in the opposite that permanently keeps the cylinder head at room temperature direction of spontaneous heat transfer, a certain amount of in a compensation measurement. The electric work supplied mechanical work W has to be supplied during one revolution. per revolution is equal to the heat Q2 extracted from the The refrigerator thus is a heat engine operated in the reverse cylinder head, that is direction. If there are no losses, the following relation between U ⋅ I the quantities involved holds: Q = (III) 2 f Q1 = Q2 + W (I). U: heating voltage, I: heating current The efficiency of a refrigerator is defined as the ratio In addition, the increase in temperature ⌬␽ of the cooling water Q is measured and the power transferred to the cooling water ␩ = 2 (II) ⌬V W P = c ⋅ ␳ ⋅ ⋅ ⌬␽ (IV) ⌬t c = 4.185 J g–1 K–1: specific heat capacity of water, ␳ = 1 g cm–3: density of water ⌬V : volume flow rate of the cooling water Determining the efficiency of the refrigerator ⌬t is determined.
    [Show full text]
  • Thermodynamic Study of a Low Temperature Difference Stirling Engine at Steady State Operation
    Int. J. of Thermodynamics ISSN 1301-9724 Vol. 10 (No. 4), pp. 165-176, December 2007 Thermodynamic Study of a Low Temperature Difference Stirling Engine at Steady State Operation Nadia MARTAJ *, Lavinia GROSU 1*, Pierre ROCHELLE *,** * Laboratoire d’Energétique et d’Economie d’Energie 50, rue de sèvres, 92 410 Ville d’Avray ** Laboratoire de Mécanique Physique 2, av. de la Gare de Ceinture 78310 Saint Cyr l’Ecole [email protected] Abstract In the current energy economy context, the use of renewable energies and the valuation of lost energies are the subject of many studies. From this point of view, the Stirling engine draws attention of the researchers for its many advantages. This paper presents a thermodynamic analysis of a low temperature Stirling engine at steady state operation; energy, entropy and exergy balances being presented at each main element of the engine. A zero dimensional numerical model describing the variables evolution (pressure, volumes, masses, exchanged energies, irreversibilities...) as function of the crankshaft angle is also presented. The calculated irreversibilities are due to imperfect regeneration and temperature differences between gas and wall in the hot and cold exchangers. A favourable comparison was made with experimental results obtained on an small size engine. Keywords: Stirling engine, numerical model, thermodynamic analysis, imperfect regeneration. 1. Introduction Cold Sink In the past few yars the understanding of the Stirling engine has shown considerable growth. Vc TDC Many new applications were developed, one of y these applications being the low temperature lr y0+l r difference Stirling engine. This new type of Vh Stirling engine is able to operate with very low BDC temperature difference between the source and the TDC sink of the engine.
    [Show full text]
  • The Stirling Engine
    THE STIRLING ENGINE STUDENT BOOKLET January 2009 Table of contents Once upon a time a surprising machine! ......................................................................................3 Let's warm up a little ......................................................................................................................4 Kinetic theory of gases...................................................................................................................6 Number of molecules and volume of a gas..................................................................................9 The effect of temperature on the volume of a gas (Charles Law) .................................... 15 The effect of pressure on the volume of a gas (Boyle-Mariotte’s Law) .......................... 21 Function of a liquid column pressure gauge (optional)...........................................................27 The effect of temperature on the pressure of a gas (Gay-Lussac's Law) ......................36 Questionnaire on the general laws of gases ............................................................................43 Back to the Stirling engine .........................................................................................................44 Nomenclature of the Stirling engine .........................................................................................45 Stirling engine operating guide ...................................................................................................46 Analysis of the laboratory Stirling
    [Show full text]
  • Comparative Study of Stirling Engine
    International Journal of Technical Research and Applications e-ISSN: 2320-8163, www.ijtra.com Volume 6, Issue 2 (MARCH-APRIL 2018), PP. 72-75 COMPARATIVE STUDY OF STIRLING ENGINE Amit Baghel1, Rajesh Yadav2, Manish Rajput3, Mayank Agrawal4, Department of Mechanical Engineering 1Student, Dayalbagh Educational Institute Agra, India 2Student, Dayalbagh Educational Institute Agra, India 3Student, Dayalbagh Educational Institute Agra, India 4Lecturer, Dayalbagh Educational Institute Agra, India Abstract—A Stirling engine is a heat engine operating by cycle the energies and high initial capital cost to install the compression and expansion of air or other gas stirling engine is a conversion technologies new generation of stirling engine that has been born to increase A Stirling engine is a heat engine that operates by cyclic the effectiveness of stirling engine .this engine is noted for its high compression and expansion of air or other gas at different efficiency compared to another engines. This compatibility with temperatures, such that there is a net conversion of heat energy alternative and renewable energy sources in which it has become increasingly significant as the price of conventional fuels rises, to mechanical work More specifically, the Stirling engine is a and also in light of concerns such as peak oil and climate change . closed-cycle regenerative this paper is mainly aimed to analyze stirling engine as a LTD or heat engine with a permanently gaseous working fluid. practical engine which has high efficiency almost nearer to the Closed-cycle,in this context, means a thermodynamic cycle in carnot cycle based engine .As a result , this study indicates how which the working fluid specific type of internal heat stirling engines work and give the higher efficiency than present exchanger and thermal store, known as the renerator The time engine.
    [Show full text]
  • The Hot-Air Engine As a Heat Engine: Recording and Evaluating the Pv Diagram with CASSY
    Heat LEYBOLD 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 LEYBOLD 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]