DOCSLIB.ORG

ANU Big Dish Steam Engine Analysis, Review and Construction

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
ANU Big Dish Steam Engine Analysis, Review and Construction ANU Big Dish Steam Engine Analysis, Review and Construction James Shepherd u4663314 Supervised by Prof. Keith Lovegrove September 2010 A thesis submitted in part fulfilment of the degree of Bachelor of Engineering Department of Engineering Australian National University Commercial In Confidence: This report contains information and descriptions that are not to be disclosed without prior consent from the Australian National University Solar Thermal Group. This thesis contains no material which has been accepted for the award of any other degree or diploma in any university. To the best of the author’s knowledge, it contains no material previously published or written by another person, except where due reference is made in the text. James Shepherd 24 September 2010 ii Acknowledgements I would like to thank Professor Keith Lovegrove for offering me the opportunity to contribute in a very small way towards the research at The Australian national University’s Solar Thermal Group. To all staff and students currently working within the ANU Solar Thermal Group, thank you for your assistance and the pleasant conversations had during lunch. Special mention should go to Geoff Major who was eager to provide assistance with even the most minor requests in what was to me, a new environment. I would also like to thank Ben Nash, Rob Gresham and Ljiljana Argy. Manufacturing of components required for the spare custom Lister Diesel Steam Engine at the Solar Thermal Group would not have been possible within the time constraints had Ben not assisted; especially as the ANU School of Engineering did not have a student workshop during this period due construction work. Finally to friends and family, who have always been there, thanks for your patience and support during this busy period in my life. iii Abstract This report investigates the condition and configuration of the current Lister HL4 Big Dish steam engine in the context of the inlet valve. The sources of failure within the mechanical pin actuating method of the inlet system are investigated along with one potential method to alleviate the potential for increased internal engine failure resulting from the complete deterioration of these pins. Analysis of the peak stresses on the valve bash pins indicate that it is unlikely that a material will be found that possesses the strength, price and machinability to withstand the harsh conditions that these components are exposed to within the cylinder of the engine. As such these components will only ever be a wear part or consumable. It is recommended that consideration be given to the replacement of the valve bash pins with solenoid actuated valve pins. It is hoped that this suggestion will lead to reduced potential for damage within the cylinder as a result of the complete failure of the current valve pins. Initial calculations indicate that the bash pins could be replaced with solenoid valves operating at 40A and around 25V. The size of an appropriate solenoid coil appears to be capable of fitting within the space limitations of the steam chest of the HL4 Big Dish steam engine, and it could probably be implemented without major engine redesigns or costs incurred. Benefits to the implementation include increase motor control through variable timing and the ability to optimise the overall efficiency of the engine, through direct data analysis; as the expansion ratio of the engine could be controlled by crank angle rather than by ad hoc methods such as, deactivation of cylinders or installation of spacer plates. However, it has been determined that running 12 solenoids of the size suggested will consume around 1kW of electrical energy or 2% of the total engine output if running at full capacity. Should the solenoid valve concept be considered reasonable by the ANU Solar Thermal Group, there is plenty of scope within the implementation of a solenoid valve to the current steam engine, along with a control system and the subsequent analysis of the steam cycle within the engine for a PHD thesis. iv Contents Chapter 1 Introduction .......................................................................................................... 1 1.1 Thesis Impetus and Objectives .................................................................................... 1 1.1.1 Current Energy Sector Environment and Issues .................................................. 1 1.1.2 History of the ANU Solar Thermal Group .......................................................... 2 1.1.3 Reciprocating Steam Engines and Energy Conversion ....................................... 2 1.1.4 STG’s Reciprocating Steam Engine .................................................................... 3 1.2 Thesis Scope and Outline ............................................................................................ 3 Chapter 2 Background and Previous Work .......................................................................... 5 2.1 Introduction ................................................................................................................. 5 2.2 Rankine Cycle Theory ................................................................................................. 5 2.2.1 Feedwater Pump................................................................................................... 7 2.2.2 Receiver Isobaric Heating .................................................................................... 7 2.2.3 Adiabatic Expansion ............................................................................................ 8 2.2.4 Isobaric and Isothermal Condensation ................................................................. 9 2.2.5 System Analysis ................................................................................................... 9 2.3 Reciprocating Engine Theory .................................................................................... 10 2.4 The ANU Big Dish System ....................................................................................... 12 2.4.1 Paraboloidal Dish Collector ............................................................................... 13 2.4.2 Solar Receiver .................................................................................................... 14 2.4.3 STG’s Lister HL4 Diesel Conversion ................................................................ 14 2.5 Prior Research and Conclusions ................................................................................ 16 2.6 Current Engine Conditions ........................................................................................ 18 2.6.1 Valve Actuator Pins ........................................................................................... 19 2.6.2 Head Gaskets ..................................................................................................... 20 2.6.3 Valve Ball-bearing and Valve Seats .................................................................. 21 2.6.4 Cylinders ............................................................................................................ 21 2.7 Summary ................................................................................................................... 24 Chapter 3 Investigation into Valve Pin Failure .................................................................. 26 3.1 Introduction ............................................................................................................... 26 3.2 Pin Failure Characteristics ........................................................................................ 26 3.3 Valve Mechanical Operation ..................................................................................... 27 v 3.3.1 Peak Contact Stresses ........................................................................................ 28 3.3.2 Buckling Critical Loads ..................................................................................... 33 3.4 Valve Bash Pin Geometric Analysis and Results ...................................................... 34 Chapter 4 Valve Pin Material Analysis .............................................................................. 36 4.1 Introduction ............................................................................................................... 36 4.2 Material Selection Parameters ................................................................................... 36 4.3 Material Selection ..................................................................................................... 37 4.4 Conclusion ................................................................................................................. 40 Chapter 5 Valve Actuator Concept Review ....................................................................... 41 5.1 Introduction ............................................................................................................... 41 5.2 Current Bash Pin Design Issues and Potential Solutions .......................................... 41 5.3 Solenoid Actuation as a Potential Replacement ........................................................ 42 5.3.1 Solenoid Operation and Advantages .................................................................. 43 5.3.2 Solenoid Disadvantages ..................................................................................... 43 5.3.3 Solenoid Valve Equations and Optimisation ..................................................... 44 5.3.4 Summary ...........................................................................................................
Load more

Recommended publications
  • Greensteam Design Report
    Greensteam Design Report Double-acting Compound - Phase I Tae Rugh Fall 2020 Initial design CAD, renders, and motivation This is a 2 stage double-acting inline compound engine. This engine replaces the traditional cross-slide by extending the piston rod through the back end of the cylinder, thereby supporting the piston on either end. This increases the amount of required seals by two, but reduces moving mass and engine complexity. Steam enters the high pressure cylinder on both ends through bash valves. After high pressure expansion, steam exits through uniflow ports into a manifold which goes to the low pressure cylinder. Here, the semi-expanded steam expands again before finally exiting through uniflow exhaust ports into the atmosphere. The timing between high and low pressure pistons is slightly offset such that for the first ~5-10% of low pressure power stroke, the low pressure piston acts as a pump to improve the exhaust performance of the high pressure cylinder. For this portion, the low pressure piston is actually doing negative work, but the hope is that this produces more efficiency gains in the exhaust process to offset these losses. This claim is not too far-fetched considering, for example, internal combustion engines also incorporate an exhaust stroke in which the piston acts as a pump to remove the exhaust gas. Of course, this mechanism will need to be validated with further calculations. Part Breakdown The crankshaft has overhung cranks on either end, much like bicycle pedals, in order to avoid the manufacturing complexities that accompany traditional (non-overhung) cranks. o The cranks are offset from each other (currently at 120 )​ such that the low pressure piston is ​ slightly ahead of the high pressure piston, which induces the vacuum pump function of the low pressure piston.
    [Show full text]
  • Greensteam Design Report: Double-Acting Uniflow Engine Part
    Greensteam Design Report: Double-acting Uniflow Engine Tae Rugh, Summer 2020 This is a single-cylinder double-acting uniflow engine with bash valve actuation. The cylinder has steam inlets on both sides, so that while one side is in power stroke, the other is in return stroke. The bash mechanism means that this engine does not need to draw from the shaft’s rotation for valve timing, which significantly reduces the complexity and number of moving parts. The drawback is that control of inlet cutoff is severely limited by geometry such that the inlet must be open before top dead center for the same amount of time as it remains open after top dead center. A single uniflow exhaust port is located in the center of the cylinder block and used for both sides. Part Breakdown The driveshaft consists of an overhung crank, flywheel, and shaft. The crank is overhung in order to reduce complexities in manufacturing. A bronze bushing is pressed into the crank and holds the crank pin, which is pressed into the piston’s connecting rod. The crank is secured to the shaft by a cotter pin. The flywheel is set to the shaft by two set screws, angled at 45°. The cylinder block includes the piston chamber, uniflow exhaust ports, and bash valves. An inner cylinder sleeve is used to maximize the area for exhaust to escape while maintaining guiding rails to keep the piston aligned. The groove on the inner cylinder allows exhaust exiting through any of the slots to continue to flow out through the exhaust port in the cylinder block.
    [Show full text]
  • Greensteam Report: Valve Actuation Systems & Further Research Tae Rugh, Summer 2020
    Greensteam Report: Valve Actuation Systems & Further Research Tae Rugh, Summer 2020 Valve Actuation Systems Greensteam aims to design a modern steam engine that maximizes simplicity and frugality while maintaining high energy efficiency. The valve actuation mechanism presents one of the most important design challenges in achieving this objective. A number of potential options have been designed, each with its advantages and drawbacks. Cam/Poppet The classic option--a staple for internal combustion engines--is the cam/poppet valve system. Unlike internal combustion engines which typically have a separate belt-driven camshaft, we can simply attach the cam to the crankshaft to reduce complexity. As the crankshaft rotates, the cam’s asymmetric shape pushes the cam follower rod up which opens a poppet valve to allow inlet steam to enter the cylinder. This system has superior sealing qualities and reliability. The drawbacks are that it can be complex to manufacture (high precision is required for the poppet head, poppet seat, and cam), it requires a heavy spring to maintain contact between the follower and cam (which reduces efficiency), and a separate poppet valve is necessary for each cylinder (meaning more moving parts). The cam shape determines the engine’s timing, but it is constrained by a number of variables. The first constraint is cutoff (cutoff is the percentage of the powerstroke duration in which steam is allowed to enter). For a 20% cutoff, the incline and decline must occur within 38° of the cam’s rotation. The second constraint is that the height offset must be sufficient for the desired inlet flow rate.
    [Show full text]
  • System Analysis of a Piston Steam Engine Employing the Uniflow PERFORMING ORGANIZATION CURE Principle, a Study in Optimized Performance 6
    General Disclaimer One or more of the Following Statements may affect this Document This document has been reproduced from the best copy furnished by the organizational source. It is being released in the interest of making available as much information as possible. This document may contain data, which exceeds the sheet parameters. It was furnished in this condition by the organizational source and is the best copy available. This document may contain tone-on-tone or color graphs, charts and/or pictures, which have been reproduced in black and white. This document is paginated as submitted by the original source. Portions of this document are not fully legible due to the historical nature of some of the material. However, it is the best reproduction available from the original submission. Produced by the NASA Center for Aerospace Information (CASI) M-TU-75-5 F^ May 1975 • 4::7SPAC1' GEORGE C ^/CNT EN^fR l SYSTEM ANALY S IS OF A P I STON STEAM ENGINE EMPLOYING THE UNIFLOW PRINCIPLE, A STUDY IN k OPTIMIZED PERFORMANCE By Jerry A. Peoples (NASA-TM-X-66918) SYSTEM ANALYSIS OF A N75-24544 PISTON STEAM SNGINE EMPLOYING THE UNIFLOW UPINCIPLE, A ST?IDY IF OPTIMIZED PE&FO..MANCE (NAS,i ) 76 p HC $4.75 CSCL 21G Unclas G3/85 21845 v t^ • v 1 / - Ito ^6 sponsored by: Technology Util ization Office K kTIONAL AERONAUTICS AND SPACE ADMINISTRATION MSFC - Furm 4S4 (Rry October 1967) y TFf'Wki1(-A1 1aFMnPT CTANr1ARr1 TITI P PAGF REPORT 40. 2 GOVERNMENT ACCESSION NO. 3, RECIPIENT'S CATALOG NO.
    [Show full text]
  • Parabolic Dish Solar Thermal Power Annual Program Review Proceedings
    5105 -83 DOE/JPL 1060-46 Solar Thermal Power Systems Project D~stributionCategory UC-62 Parabolic Dlsh Systems Devebpment Parabolic Dish Solar Thermal Power Annual Program Review Proceedings May 1,1981 Prepared for U.S. Department of Energy Through an agreement wlih Natlonal Aeronautics and Space Adm~nistration by Jet Propuls~onLaboratory Cal~forn~aInsh, ~teof Technology Pasadena. Cahfornia (JPL F'UBLICATION 81-44) 5105 -83 DOE/JPL U60-46 Solar Thermal Power Systems Project Distribution Category UC-62 Parabolic Dish Systems Development .I :: # a -. i- Parabolic Dish 3.*. ' i Solar Thermal Power . *_ ~ a h Annual Program Review Proceedings May 1,1981 Prepared for U S. Department of Energy Throuah an aareement wltk ~at106al~eroiautics and Space Admmistration by Jet Propulsion Laboratory Callforn~alnstltute of Technology Pasadena, Callfornla (JPI . PUBLICATION 81-44) Prepared by the Jet Propulsion khontory, California Institute of Technology, for the U.S Department of Energy through an agreement with the Natrond Aere nautics and Space Administration. The JPL Solar Thermal Power Systems Project is sponsored by the U.S. Depart- ment of Energy and fxms a part of :he Soh Thermal Rognm to develop low- cost solar thermal and electric power plantr Thb report was prepared as an account of work sponsored by the United States Government. Neither the United States nor the United States Department of Energy, nor any of their employees, nor any of their contractors. subcontractors, or theu employees. makes any warranty, cxpress or implied, or assumes any legal liability or respons~bilityfor the accuracy, completeness or usefulness of any in- formation, apparatus.
    [Show full text]
  • Owner's Manual
    MODEL 49104 owner’s manual INTRODUCTION 3 BEFORE YOU Thank you for purchasing a Traxxas T-Maxx Nitro Monster Truck. PROCEED Traxxas engineers have loaded your T-Maxx with innovative features Traxxas Support and incredible “drive-over-anything” performance that you won’t find Traxxas support is with you every step of the 4 SAFETY way. Refer to the next page to find out how to PRECAUTIONS anywhere else! contact us and what your support options are. Your T-Maxx combines automatic, two-speed shifting in forward 5 TOOLS, SUPPLIES, and reverse, with powerful four-wheel disc braking. The patented AND REQUIRED Quick Start transmission design and TQ 2.4GHz system put these functions right at EQUIPMENT This manual is designed with a Quick your fingertips. Start path that outlines the necessary 6 ANATOMY OF The TRX 2.5 engine is one of the most powerful engines of its size procedures to get your model up THE T-MAXX ever available in a Ready-To-Race® truck. Two years of engineering and running in the shortest time possible. If you are an development and advanced design, along with thousands of hours of experienced R/C enthusiast, you will find it helpful and fast. 7 QUICK START: testing, puts the TRX 2.5 in a class by itself. Each part of the TRX 2.5, Be sure and read through the rest of the manual to learn GETTING UP TO from the air filter on the slide carburetor, to the tip on the dyno-tuned about important safety, maintenance, and adjustment SPEED exhaust system, has been carefully engineered to provide maximum procedures.
    [Show full text]
  • Roger L. Demler Foster-Miller Associates, Inc. Waltham, Massachusetts
    STEAM ENGINE RESEARCH FOR SOLAR PARABOLIC DISH Roger L. Demler Foster-Miller Associates, Inc. Waltham, Massachusetts ABSTRACT A steam engine design and experimental program is exploring the efficiency potential of a small 25 kW compound reheat cycle piston engine. An engine efficiency of 35 percent is estimated for a 700°C steam temperature from the solar receiver. BACKGROUND The parabolic dish solar concentrator provides an opportunity to generate high grade energy in a modular system. Most of the capital cost is projected to be in the 2ish and its installation. Assurance of a high production demand of a standard dish could lead to dramatic cost reductions. High ~roductionvolume in turn depends upon maximum application flexibility by providing energy output options, e.g. heat, electricity, chemicals and combinations thereof. Subsets of these options include energy storage and combustion assist. Individual dish mounted engine generator sets represent a major market opportunity . The Market Projecting new product market potential is a risky business. Presuming success in meeting system cost and performance goals, dish-engine production has been studied in the 10,000 to 100,000 range of annual unit volume. Selection of the best engine type from among the Brayton, Stirling and Rankine engines will have to wait for development results. The Steam Rankine Engine The positive displacement steam engine is an excellent fit in the component chain. High efficiency at moderate temperatures (55 to 59 percent of Carnot) yields high dish and receiver efficiencies as well. Engine efficiency is insensitive to load and ambient variations. A high efficiency 60 Hz alter- nator can be directly driven.
    [Show full text]
  • Mechatronic Steam Valve Samuel Hince Anthony Ochoa Spring 2020
    Mechatronic Steam Valve Samuel Hince Anthony Ochoa Spring 2020 1. Introduction/Overview of Initial Design Goals The overarching goal of the valve portion of GreenSteam has been to find a low power, fast actuating, highly reliable, mechatronic valve solution to best optimize the power output of the proposed GreenSteam engine. This report is a summary of the research conducted to this end. Time was initially invested into finding quick, cheap, off the shelf options. This was done to create figures for engine designers to pull from as well as create a solution that already had extensively tested specs and was easy to replace. Eventually this led to initial research into the best mechanism and materials suited for high heat/pressure actuation. Preliminary investigation was done into the feasibility of custom mechatronic, and mechanical, solutions. An additional reading list has been compiled for use in onboarding additional members to the GreenSteam Valve team. The research presented below has been conducted with an emphasis on small scale valves which might be appropriate for an engine of approximately 1 cubic inch per cylinder, operating at speeds at or below 500RPM. Additional assumptions include a supply pressure which can be varied to meet the valve’s capabilities and steam temperatures around 150-170 degrees celsius. 2. Valve Actuation Solutions explored 2.1 Piezoelectric Piezoelectric Valves have been tested extensively to be reliable in high heat, corrosive environments, as well as in vacuum(tech briefs cite). With extremely fast actuation times(numbers here), precise control, and low power draw, Piezo actuated valves are an incredibly enticing solution to the design goals of Green steam.
    [Show full text]
  • A Weektjy Journal of Practtcal Information
    [Entered Il..t the Post omee of New York. N. Y., as Second Class Matter.] A WEEKTJY JOURNAL OF PRACTTCAL INFORMATION. ART. SCIENCE. MECHANICS. CHEMTSTRY AND MANUFACTURES. 15.-, Vol. [NEWXLVI.-No. SERIES.] NEW YORK} APRIL 15, 1882. [$3.20[roB'rAGE perAIIDllm. PREPA.lD.] c ---�---- -... - - - - - --- ----,-_.. __ ._," ...-- - . - '- . � - ------- - c-=-. ..... _--. .. -: .. --- .. -:'.�-- Fig.l.-BIRD'S EYE VIEW OF COAL PIERS AND DOCKS HOBOKEN. Fig. 7.-RET11RN SWITCH, RIVER END OF THE PIER. Fig.2.-VIEW OF TBACX8, mCLlNER, AND PIERS, FRO. SHORE SIDE. THE GRAVITY COAL pmRS OF THE DELAWARE, LACKAWANNA & WESTERN RAILROAD CO., B;Ql,30KEN, N.; .. ,. © 1882 SCIENTIFIC AMERICAN, INC J Citutifi£ �mttinu•• [ APRIL 15. 1882. NEW FIELD A �OR INVENTION. tbousand miles of tbe sun, passing through the corona and �mttitan. A correspondent, writing from New South Wales, calls perhaps grazing the pbotosphere. Mr. Boss estimates the �titntifir attention to a wide and promising field of invention which distance at ten million miles, but both observers agree in does not appe r to have been much explored. In all parts prop esy n ery near approacb. Few in an e are re­ EST'ABLISHFJD 1845. a h i g a v st c s of the world there are many noxious plants, which cultiva- corded of comuts comiug so near the sun. Those of 1880, MUNN & CO., Editors and Proprietors. tors of the soil find it difficult or impossible to eradicate by 1843, and 1680 bad nearly the same perihelion distance, but PUBLISHED WEEKI,Y AT the means now in nse. In New Soutb Wales, for in stance, these dates are considered by many astronomers as marking No.
    [Show full text]
  • The Development, Construction and Testing of a Piston Expander for Small-Scale Solar Thermal Power Plants
    The development, construction and testing of a piston expander for small-scale solar thermal power plants by Bradley Da Silva Thesis presented in partial fulfilment of the requirements for the degree of Master of Engineering (Mechanical) in the Faculty of Engineering at Stellenbosch University Supervisor: Prof Chris Meyer March 2018 Stellenbosch University https://scholar.sun.ac.za Declaration By submitting this thesis electronically, I declare that the entirety of the work contained therein is my own, original work, that I am the sole author thereof (save to the extent explicitly otherwise stated), that reproduction and publication thereof by Stellenbosch University will not infringe any third party rights and that I have not previously in its entirety or in part submitted it for obtaining any qualification. March 2018 Copyright © 2018 Stellenbosch University All rights reserved i Stellenbosch University https://scholar.sun.ac.za Abstract The development of a prototype variable valve duration reciprocating steam expander was undertaken. A variable valve duration system was developed which could vary the cut-off ratio from 15 % to 90 %. An existing internal combustion engine was converted into the prototype reciprocating steam engine. Thermodynamic models were developed to determine the theoretical power output and working fluid consumption of the manufactured prototype engine. Proof of concept tests were performed on the engine. The engine was operated at 500 rpm where the output power and air consumption were measured. Tests were performed for various cut-off ratios to determine the influence on output power and air consumption. The experimental results showed a strong correlation to the theoretical effect of cut-off ratio on power output and air consumption.
    [Show full text]
  • "Refrigerant Engine" Or "Aerothermal Engine"- "A.T.E." an Experimental Gasoline Engine Modification
    FOR FREE THINKING RESEARCHERS ONLY "REFRIGERANT ENGINE" OR "AEROTHERMAL ENGINE"- "A.T.E." AN EXPERIMENTAL GASOLINE ENGINE MODIFICATION. TURN AN OPEN INTAKE/OPEN EXHAUST HEAT BASED GASOLINE ENGINE INTO A "CLOSED LOOP" COLD REFRIGERANT BASED ENGINE. THE ULTIMATE ENERGY SOURCE FOR THIS ENGINE IS HEAT. IN PRACTICAL USE, HEAT IS PROVIDED BY THE SUN, AND IS EXTRACTED IN AN ECONOMICAL FASHION. EXCESS HEAT ENERGY IS PRESENT IN INEXTINGUISHABLE QUANTITIES ON PLANET EARTH. CONSTRUCTION COMMON GASOLINE ENGINE, 2 CYCLE OR 4 CYCLE. NOTE: 2 CYLINDERS MUST HAVE 180 DEGREE CRANKSHAFT. NO 3 OR 5 CYLINDER ENGINES. NO DIESEL. 1. CONNECT EXHAUST PIPE/TUBE TO INTAKE PIPE/TUBE AT CLOSEST POINTS POSSIBLE, WITHOUT LEAKS, MAKING ENGINE CLOSED LOOP OPERATION. 2. ADD A T-FITTING OR OUTLET CONNECTION TO THE EXHAUST/INTAKE LOOP, PREFERABLY NEARER THE EXHAUST MANIFOLD. 3. ADD A ONE WAY CHECK VALVE AT THE EXIT OF THE T-FITTING/CONNECTION. CHECK VALVE EXAMPLE- PARKER PNEUMATIC VALVE OPENS AT 5-7 PSI (11 PSI MAXIMUM). 4. BEYOND THE CHECK VALVE, ADD A BALL VALVE TO REGULATE FLOW. 5. BEYOND CHECK VALVE/BALL VALVE ASSEMBLY, CONTINUE PIPE/TUBE TO INLET SIDE OF AN AIR CONDITIONING PUMP, THAT IS IN OPERATING CONDITION, AND ALREADY ATTACHED TO THE ENGINE. 6. OUTLET OF THE AIR CONDITIONING PUMP GOES THROUGH ONE OR MORE CONDENSER COILS, AND THEN TO A SMALL ACCUMULATOR ABOVE THE FUEL INJECTOR, WHICH IS MENTIONED LATER. CONDENSER MUST BE COOLED BY FAN AND/OR AIRFLOW. 7. REMOVE SPARK PLUG(S). MAKE AN ADAPTER TO INSTALL AN LPG/PROPANE TYPE FUEL INJECTOR INTO SPARK PLUG OPENING.
    [Show full text]
  • The Steam Car Page 35
    steamcar-template.qxp 15/11/2005 22:28 Page 35 (c) Respiratory problems in the blast pipe restricting the exhaust (contributory) Had this issue been resolved greater power, greater economy may well have resulted. "Review of Testing and Evaluation of an Improved Steam Engine" by Roy A Renner (Courtesy "The Steam Automobile VOL 25 No 2 1983") This forward thinking team took Steam Car engine efficiency to very creditable 24% and appear to have reached similar conclusions and I quote "Another design improvement has been proposed to reduce throttling losses at the first stage inlet (poppet valve). As steam chest can be installed upstream of the inlet (poppet) valve, storing enough steam to allow filling the cylinder with a minimum pressure drop in the steam line. Of course the steam chest would be heavily insulated." The Single Headed Poppet Valve Advantages * Capable of handling vast quantities of superheated Steam. * Comfortably able to handle steam temperatures in excess of 1,500oF * Little potential for leakage * No rubbing contact with sealing surfaces, minimum friction * Separate steam admission and steam exhaust valve * Very short cut-offs indeed can be achieved * Variable exhaust and inlet timing, able to be optimised for best performance * Minimum clearance volume can be achieved * Can be made self opening in the event of water compression * Does away with upper cylinder lubrication, as only the valve guide requires lubrication. Modern seals will prevent oil ingress into the cylinder head. * A self-opening admission valve could nullify the effect of clearance volume and increase steam temperature by compression and improve efficiency (doubtful).
    [Show full text]