DRY SUMP PUMP BUBBLE ELIMINATION FOR HYDRAULIC HYBRID VEHICLE SYSTEMS

DRY SUMP PUMP BUBBLE ELIMINATION FOR HYDRAULIC HYBRID VEHICLE SYSTEMS By Jason Moore A Thesis Submitted to the Faculty of the DEPARTMENT OF MECHANICAL ENGINEERING In Partial Fulfillment of the Requirements For the Degree of MASTER OF SCIENCE In the Department of Mechanical Engineering THE UNIVERSITY OF MICHIGAN 2007 Committee Members: Albert Shih Professor, ME Zoran Filipi, Research Associate Professor, ME Acknowledgements First I would like to thank my faculty advisors, Professor Albert Shih and Professor Zoran Filipi for there supervision and support I would also like to thank the Environmental Protection Agency by which this project was funded and especially Neil Johnson, Andy Moskalik, and Tony Tesoriero for their guidance and insight from the EPA on this project I also thank David Swain for working with me on my hydraulic bicycle project and first sparking my interest in hydraulic technology I also thank my parents, John and Beth Moore, for their support and encouragement Table of Contents List of Figures .i List of Tables i Biography iii Abstract .iv Chapter Introduction .1 1.1 Literature Review of Hydraulic Fluid Bubble Elimination 1.2 Efficiency Testing of Deaeration Devices Literature Review 1.3 Goals and Objectives 1.4 Overview of Thesis Chapter Bubble Elimination Efficiency Testing Apparatus .8 2.1 Overview .8 2.1.1 Description of fluid flow diagram 2.1.2 Closed loop system 11 2.1.3 Necessity of second dump tank .12 2.1.4 Check valves 12 2.1.5 Clear tubes .12 2.1.6 Drip tank 12 2.2 BEETA Component Design and Selection 13 2.2.1 Mixing air and hydraulic fluid 13 2.2.2 Graduated cylinder 13 2.2.3 Hydraulic fluid tanks .15 2.2.4 Pressure gauges .15 2.2.5 Mass flow meter .15 2.2.6 Borrowed items and petty cash items 16 2.3 Fabrication .16 2.3.1 Bracketry items 17 2.3.2 Routing hydraulic lines 18 2.4 Electrical Setup and Data Acquisition 18 2.4.1 Wiring schematic 18 2.4.2 Data acquisition .19 2.5 Procedure for Use 20 Step 1: Presetting all the valves 20 Step 2: Start air flow .21 Step 3: Start hydraulic fluid flow 21 Step 4: Back pressure .21 Step 5: Begin test 21 Step 6: Stopping the hydraulic fluid flow 21 Step 7: Final measurements and draining the system 22 Chapter Performance Efficiency and Testing Results 23 3.1 Bubble Removal Efficiency 23 3.2 Experimental Procedure 24 3.3 Results Effect of Flow Rate 25 3.4 Results Effect of Vent Pressure 27 3.5 Comparison with Suzuki et al [Error: Reference source not found] Testing Results .28 3.6 Conclusions from Testing .30 Chapter Theory of Dissolving Gas and Forces on Bubbles 31 4.1 Henry’s Law for Dissolved Gas .31 4.1.1 Cyclone pressure effect on dissolved gas 32 4.2 Forces Acting on Air Bubble 32 4.2.1 Drag 32 4.2.2 Buoyancy 33 4.2.3 Centrifugal force 34 4.3 Bubbles Naturally Settling out of Fluid .34 4.3.1 Dependence on bubble size 34 4.3.2 Dependence on pressure above fluid 35 4.3.3 Dependence on temperature 36 4.4 Conclusions from Theory .38 Chapter Conclusions and Recommendations 39 Appendix A: Survey Deaeration devices 41 Appendix B: Sizing of Graduated Cylinder 53 Appendix C: Bill of Materials 54 Appendix D: Petty Cash Spent 56 Appendix E: Items Borrowed from EPA 57 Appendix F: Matlab Program for Data Collection Analysis .58 Appendix G: Vacuum System for Dry Sump Pump .63 Resources 64 List of Figures Figure 1.1 Dry sump pump fluid diagram Figure 2.1 Overview of bubble elimination efficiency testing apparatus (BEETA) .9 Figure 2.2 Fluid diagram for the BEETA system 10 Figure 2.3 Koflo static mixer 13 Figure 2.4 Screen mixer inside clear tube 13 Figure 2.5 Graduated cylinder full of hydraulic fluid 14 Figure 2.6 Minimum and maximum flow meter range 16 Figure 2.7 Lower shelf .17 Figure 2.8 Valve bracket 17 Figure 2.9 Fluid lines routed underneath BEETA system table .18 Figure 2.10 Electrical wiring diagram .19 Figure 2.11 User interface for data acquisition .20 Figure 3.1 Cyclone bubble elimination performance .26 Figure 3.2 Increasing Pdelta effect on low flow rates .27 Figure 3.3 Lack of efficiency to varying Pdelta .28 Figure 3.4 Suzuki et al testing results [Error: Reference source not found] 29 Figure 3.5 Suzuki et al testing results reorganized [Error: Reference source not found] .29 Figure 4.1 Buoyancy force on bubble .33 Figure 4.2 Rise velocities strong dependence on bubble radius .35 Figure 4.3 Low pressure bubble rise velocity effect 36 Figure 4.4 Temperature bubble rise velocity effect 38 List of Tables Table 1: Starting Valve Configuration .20 Table 2: Low Flow Rate Testing .24 Table 3: High Flow Rate Testing .24 i Table 4: Constants of Solubility in Hydrocarbon Fluid [] 32 ii Biography Jason Moore was born in Marion, Indiana in 1984 He is the son of John and Beth Moore In 2002 he enrolled at the University of Michigan and completed his bachelor’s degree in mechanical engineering and received a minor in math after four years of school Jason spent the last year pursuing a Masters degree in mechanical engineering under the guidance of Professor Albert Shih and Professor Zoran Filipi Jason plans to continue his education and pursue a PhD in mechanical engineering at the University of Michigan iii Abstract The goal of this research is to investigate bubble elimination via cyclone bubble eliminator for use in a dry sump pump system, for the specific application of hydraulic hybrid vehicles Air bubbles in a hydraulic system cause poorer efficiencies, pump cavitation, oil deterioration, noise generation, and oil temperature rise For hydraulic hybrid vehicle systems, dry sump pumps are more efficient than wet sump pumps but have the aeration issues because of the air on the opposite side of the pistons The fluid leaks to the air and will eventually need to be deaerated and returned to the system This research investigates the mechanical cyclone system for deaeration A bubble elimination efficiency testing apparatus (BEETA) was built to measure the efficiency of the cyclone bubble elimination device The BEETA system measures the amount of air in the fluid air mixture going into the bubble eliminator and then measures the quantity of air in the fluid mixture exiting the bubble eliminator, therefore allowing the determination of the bubble eliminator efficiency Testing results reveal that the cyclone device removes less than 95% of small bubbles (< 0.75 mm radius), which is unacceptable for a dry sump pump application A model was developed to explain the effects of pressure, temperature, and bubble radius on a bubble in hydraulic oil iv Chapter Introduction Hybrid vehicles use a mixture of power sources to be more energy efficient and environmentally friendlier than conventional automotive drive systems [1,2] Two types of hybrid technology are the electric hybrid and hydraulic hybrid Electric hybrid vehicles connect a generator to the engine and a battery system stores energy from the generator In a parallel electric hybrid, the engine and an electric motor drive the wheels In a series electric hybrid, the battery system powers electric motors that drive the wheels Hydraulic hybrid vehicles connect a hydraulic pump to the engine that then stores energy in accumulators In a parallel hydraulic hybrid a hydraulic motor retrieves energy from the accumulators and assists the engine in powering the wheels This system uses fewer components than a series system and therefore is ideal for smaller vehicles In a series hydraulic hybrid a hydraulic motor completely powers the wheels Series systems are more energy efficient than parallel and due to hydraulics ability to transfer high power this system is ideal for heavy vehicles The engine in hybrid vehicles can run at an optimum speed range for better efficiency and lower emissions [Error: Reference source not found] Regenerative breaking can be implemented to recover energy normally lost in braking [3] Electric hybrids are currently being successfully manufactured and sold to consumers The electric hybrids obtain better gas mileage than conventional drive systems in city driving However, for large vehicles, the electric hybrids lack the efficiency at high power and cost more [4] Hydraulic hybrid systems offer better efficiency for heavy vehicles and are more efficient at regenerative breaking than electric hybrid vehicles [5,6,7] However, hydraulic hybrid vehicles have yet to be manufactured for general consumers because of a lack of technology and packaging problems [8] Packaging is a serious challenge because many of the hydraulic components, especially the accumulators, are fairly large and cannot easily fit into existing vehicle dimensions Hydraulic hybrid propulsion systems can either use dry or wet sump pumps Dry sump pumps contain a series of pistons to allow for variable displacement pumping where hydraulic fluid is on one side of the piston (fluid being pumped) and air on the opposing side of the piston In wet sump pumps both sides contain hydraulic fluid – one side is high pressure fluid being pumped and the other is stationary low-pressure fluid Dry sump pumps are more efficient than wet sump pumps because the air is less viscous than the hydraulic fluid and therefore offers less resistance Recent testing at the US Environmental Protection Agency (EPA) shows 2.5% efficiency improvement of a dry sump pump over a wet sump pump when running at 3000 rpm and 13.8 MPa [9] The downfall in using dry sump pumps in hydraulic hybrid vehicles is that hydraulic fluid will leak around the piston into the air side of the pump and become aerated (bubbles and dissolved gas) [Error: Reference source not found] The aerated hydraulic fluid is then returned to the main line of the hydraulic system and can cause damage Bubbles in hydraulic fluid cause poorer efficiencies, pump cavitations, oil deterioration, noise generation, and oil temperature rise [10,11] Dissolved gas is not as dangerous to the system components; however, the dissolved gas can easily form into bubbles from pressure changes in the system [12] The aerated oil will need to be deaerated The dry sump pump hydraulic system with deaeration is illustrated in Figure 1.1 The red lines indicate aerated fluid The black lines illustrate deaerated fluid which is able to be used in the main line of the system The deaeration system for a dry sump pump is the focus of this paper A.3 CONCLUSIONS AND RECCOMENDAIONS: Based on my research the mechanical degassing device is most promising It is available for $700.00 It is small in size and requires little energy input Looking towards the future the device could be implemented into the main line The disadvantages of the other systems are hindered by their development time or the ability to scale the idea up to the main line Membrane degassing devices are quite large, making them unrealistic to scale up to the main line A settling tank will require more experimentation before we know the exact size needed for our flow requirements (even more experimentation will be needed for the described enhancements) The NASA design combines membrane and mechanical degassing, which has not been verified to work on Earth Chemical additives may work, but experimentation will be needed to determine its effectiveness For these reasons, we recommend a mechanical degassing method be purchased for further tested 52 Appendix B: Sizing of Graduated Cylinder Minimum readable change B (ml) = Height of cylinder D (cm tall) = Volume of C C(ml) = MaxVbubble _ out = 40 200 C C A +C D A (gal)= 1.89 3.79 5.68 7.57 9.46 11.36 13.25 15.14 17.03 18.93 20.82 22.71 24.61 26.50 28.39 30.28 32.18 34.07 35.96 A (ml) 1893 3785 5678 7571 9464 11356 13249 15142 17034 18927 20820 22712 24605 26498 28391 30283 32176 34069 35961 MinVbubble _ out = Maximum Minimum 0.095570 0.000478 0.050183 0.000251 0.034024 0.000170 bubble_out 0.025737 0.000129 0.020696 0.000103 0.017307 0.000087 0.014871 0.000074 0.013036 0.000065 0.011605 0.000058 0.010456 0.000052 0.009515 0.000048 0.008729 0.000044 0.008063 0.000040 0.007491 0.000037 0.006995 0.000035 0.006561 0.000033 0.006177 0.000031 0.005836 0.000029 0.005531 0.000028 B A +C V A 53 Appendix C: Bill of Materials Part Needed Mixer Dump tank Fluid tank measuring tank mass flow Company Koflo McMaster Carr Polyfab Omega meter clear Phone Part Qu Cost (each) Total 3700 no 3/8-21 630-833- 62945K12 1 $117.00 $146.13 $117.00 $146.13 0300 62945K14 978-657- custom $228.35 $228.35 7704 sales: 1- $980.00 $980.00 10 $544.00 $544.00 9161K53 $5.85 $40.95 49035K85 $21.28 $21.28 9161K33 $9.54 $9.54 Number 847-516- stratos part made 888-TC- FMA-A23OMEGA fittings for PVC pipe 8' clear section of McMaster Carr PVC pipe 630-8330300 Clear PVC T Continued on next page 54 Part Needed air Company Phone Part Number Qu Cost (each) Total regulator and gauge mounting 4246k61 $42.98 $42.98 bracket grade 1A 4246K11 $5.58 $5.58 $26.32 $26.32 $26.32 $26.32 $48.65 $97.30 $57.07 $57.07 air pressure gauge grade 1A air 3708k21 0-60psi McMaster Carr 630-8330300 pressure 3708k21 gauge grade 1A 0-100psi oil pressure 4088K3 gauge grade 1A 0-100psi oil pressure gauge 4088K7 (flange) 0-60 psi 1-888- Grainger Barb fitting 361-8649 5A247 35 $2.05 Petty cash various hardware stores and Radio Shack, for details see petty cash items table $71.75 $167.96 Total $2,582.53 55 Appendix D: Petty Cash Spent Company Ace Hardware Ace Hardware Ace Hardware The Home Depot The Home Depot Date Item Description Used For Mounting screws for ball 10/25/2006 box of wood screws valve brackets Used to Polish bubble 11/2/2006 fine sand paper viewing tube Bolts, nuts, and Mounting various parts of the 11/11/2006 washers BEETA system 2"X4" boards of 10/26/2006 wood Lower shelve support zip ties and hose Mounting various parts of the 11/5/2006 clamps BEETA system buckets and The Home various hose buckets for transporting fluid, Depot 11/11/2006 clamps hose clamps for mounting PVC glue and The Home primer, nuts and PVC glue and primer used to Depot 10/31/2006 bolts join PVC together Wood drill bit used to drill The Home hose clamps, wood holes in the BEETA system Depot 11/7/2006 drill bit table Carpenter Used for low pressure lines Brothers 11/16/2006 Tubing on the BEETA system Harbor Teflon tape, fittings, Used throughout the BEETA Freight Tools 11/5/2006 Air hose system Carpenter Brothers 12/9/2006 J B Weld Screen filter construction Electrical Carpenter connectors and Brothers 12/8/2006 electrical tape Wiring of the BEETA system AC-DC transformer Radio Shack 12/8/2006 and wire Powers fluid flow meters Total Cost 4.23 7.37 12.49 4.18 9.84 24.48 12.01 12.54 9.22 19.65 5.08 8.23 38.64 167.96 56 Appendix E: Items Borrowed from EPA Quantity 2 1 1 1 Item Borrowed Swagelock R9FFB0201B - Male Quick Disconnect Swagelock R9GBKA005B - Female Quick Disconnect 1/4" Butech 2-way Valves Janus K63 1/4" Butech 3-way Valve Janus 3-K63 Parker NV400S Throttle Valve with Handle (Gray) Deltrol CMM25B Brass Check Valve Parker C400S Check Valve Jayco #312 1/2" 80psi Bronze Relief Valve Flow Technologies FT6-8AEU3-LEA-2034 Flow meters Flow Technologies A1-5-C-V2-1-1 (991031) RF Pickoff Flow Technologies 27-94057-110 RF Pickoff Flow Technologies 30880-101 Magnetic Pickoff 20 Male Pipe to -16 Male JIC adapter Delta-Power hp electric motor with A-23 gear pump JIC #4 Fittings Quantity 12 11 Type 90deg male-female straight male-male straight female-female 45deg male-female T male-male-female T all female T all male T male-female-male NPT to JIC Fittings Quantity 4 2 Size NPT 1/4" to JIC #4 NPT 1/4" to JIC #4 NPT 1/4" to JIC #4 NPT 3/16" to JIC #4 NPT 1/2" to JIC #6 NPT 1/2" to JIC #8 Type male-male female-male male-female female-male female-male male-female 57 NPT 1" to JIC #16 male-male JIC to JIC Conversion Fittings Quantity 2 Size JIC #6 to JIC #4 JIC #8 to JIC #4 JIC #8 to JIC #4 JIC #12 to JIC #4 JIC #16 to JIC #4 T JIC #4 Type female-male female-male male-male female-male female-male male-male-female Barb Fittings Quantity 16 1 Size JIC #4 to 1" barb JIC #12 to 1/4" barb 3/4" NPT to 1" barb Type female-barb female-barb male-barb Appendix F: Matlab Program for Data Collection Analysis clear all % Reads Data output from BEETA system A=textread('switchdiriction.txt'); %Inflow fluid %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% persec=A(1,1); count=-1; k=2; 58 frequency(1)=0; time(1)=0; last=1; for i=2:(length(A)-1) count=1+count; point=A(i,1); %if point is low if point4.5; last=1; end end frequency=1./(period*(1/persec)); sum=0; num=0; for i=3:length(frequency) sum=frequency(i)+sum; 59 num=1+num; end average_frequency=sum/num; frequency(1,2)=average_frequency; %outgoing fluid %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% count=-1; k=2; frequency2(1)=0; time2(1)=0; last=1; for i=2:(length(A)-1) count=1+count; point=A(i,3); %if point is low if point4.5; last=1; 60 end end frequency2=1./(period2*(1/persec)); sum=0; num=0; for i=3:length(frequency2) sum=frequency2(i)+sum; num=1+num; end average_frequency2=sum/num; frequency2(1,2)=average_frequency2; %air incoming %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% airvolt=rot90(A(:,2)); time3= 0:1/persec:(length(airvolt)-1)*(1/persec); average_voltage=mean(airvolt); %Solutions %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% average_voltage average_frequency2 average_frequency inflow_rate=average_frequency*.0097+.014 61 drainflow_rate=average_frequency2*.0097+.014 plot(time,frequency,time2,frequency2) title('Hydraulic Flowmeter Data') xlabel('Time (seconds)') ylabel('Frequency (hz)') legend('Inflow','Drainage flow') figure plot(time3,airvolt) title('Air Flowmeter Data') xlabel('Time (seconds)') ylabel('Voltage (volts)') 62 Appendix G: Vacuum System for Dry Sump Pump Deaerated oil Aerated oil 63 Resources 64 [] Ping Zheng, Anyuan Chen, Peter Thelin, Waqas Arshad, Chandur Sadarangani (2007) “Research on a Tubular Longitudinal Flux PM Linear Generator Used for Free-Piston Energy Converter” Eml symposium Paper #81 [] Paul Cook, Peter James, Mark Willows (2002) “Rapid Prototyping of Generic Hybid Concept Vehicles” SAE paper 2002-01-0755 [] Morteza Montazeri-Gh, Amir Poursamad (2006) “Application of Genetic Algorithm for Simultaneous Optimixation of HEV Component Sizing and Control Strategy” Int J Alternative Propulsion Vol No [] F V Conte (2006) “Battery and Battery Management for Hybrid Electric Vehicles: a Review” E&I September 2006 [] Mohammad Elahinia, Walter W Olson (2006) “Chassis Vibration Control for Hydraulic Hybrid Vehicles” SAE paper 2006-01-1970 [] R P Kepner (2002) “Hydraulic Power Assist – A Demonstratino of Hydraulic Hybrid Vehicle Regenerative Braking in a Road Vehicle Application” SAE paper 2002-01-3128 [] R Apter, M.Prathaler (2002) “Regeneration of Power in Hybrid Vehicles” IEEE [] Neil Johnson Personal Interview April 2007 [] Andy Moskalik Personal Interview May 2007 10 [] W D Phillips (2006) “The High-Temperature Degradation of Hydraulic Oils and Fluids” Journal of Synthetic Lubrication #23 11 [] George Deuard Totten, Lauralice de Campos Franceschini Canale, Hong Liang (2005) “Hydraulic Cavitation from a Sonomaterials Science Perspective: A Review” SAE paper 2005-01-4173 12 [] P Hodges (1996) Hydraulic Fluids Elsevier 13 [] “Degassing Pump, Degassing Equipment” Yokota Manufacturing Co Jun 2006 14 [] “Bubb-Less” G.E Totten & Associates G.E Totten & Associates Jun 2006 15 [] Ryushi Suzuki, Yutaka Tanaka, Kazuyoshi Arai, Shinich Yokota (1998) “Bubble Elimination in Oil for Fluid Power Systems” SAE paper 982037 16 [] Ryushi Suzuki, Yutaka Tanaka (2002) “Solution of Air Entrainment for Fluid Power Systems” SAE paper 2002-01-1387 17 [] H Yamaguchi, D Matsubara, S Shuchi (2001) “Flow Characteristics and Micro-Bubbles Behaviour in a Rotating Pipe Section with an Abrupt Enlargement” IMechE 18 [] C Knuppel, K Brodt, J Resemann, G Tan (2001) “Development of Membrane Based Gas Trap” SAE paper 2001-01-2294 19 [] “Bubble Eliminator Based on Centrifugal Flow” Lyndon B Johnson Space Center, Houston, Texas 20 [] “Degassing module for chemical fluids” Dainippon Ink and Chemicals Jun 2006 21 [] Stu Nemser Telephone Interview “Compact Membrane Systems Specifications” 31 May 2006 22 [] Stephen F Yates, Tihomir Tonev, Allen K MacKnight, Robert J Kay (2006) “Modified X Zeolites as Next Generation Carbon Dioxide Adsorbents” SAE paper 2006-01-2194 23 [] Yang, Ralph Personal Interview “Zeolite Oil Applications” Jun 2006 24 [] Chris Morgan, Jill Cummings, Roy Fewkes (2004) “A New Method of Measuring Aeration and Deaeration of Fluids” SAE paper 2004-01-2914 25 [] Teyssedout, Aube, and Champagne “Void fraction measurement system for high temperature flows” 25 Aug 2006 26 [] Hamad, Imberton, and Bruun “An optical probe for measurements in liquid-liquid twophase flow” 26 Aug 2006 27 [] “Flow & Level Measurement” Transactions vol 15 Aug 2006 28 [] J Jalber, R Gilbert, M.A El Khakani (2002) “Comparative Study of Vapor-Liquid Phase Equilibrium Methods to Measure Partitioning Coefficients of Dissolved Gasses in Hydrocarbon Oils” Vieweg & Sohn Verlagsgesellschaft 29 [] “Bubble Hydrodynamics” 24 February 2007 30 [] Mobile 3/14/2007 31 [] Roland Bishop Telephone Interview Jun 2006 32 [] Seigo Matsuzaki Telephone Interview Jun 2006 33 [] “AMSOIL Synthetic Automatic Transmission Fluid for Smooth Shifting” 2006 PerformanceMotorOil.com 31 May 2006 ... is to investigate bubble elimination via cyclone bubble eliminator for use in a dry sump pump system, for the specific application of hydraulic hybrid vehicles Air bubbles in a hydraulic system... completed on the dry sump pump bubble elimination for hydraulic hybrid vehicle systems project Chapter Bubble Elimination Efficiency Testing Apparatus: BEETA was constructed and allows for experimental... efficiencies, pump cavitation, oil deterioration, noise generation, and oil temperature rise For hydraulic hybrid vehicle systems, dry sump pumps are more efficient than wet sump pumps but have