Dynamic and Efficiency Characteristics of an Inlet Metering Valve Controlled Fixed Displacement Pump
Total Page：16
File Type：pdf, Size：1020Kb
DYNAMIC AND EFFICIENCY CHARACTERISTICS OF AN INLET METERING VALVE CONTROLLED FIXED DISPLACEMENT PUMP _______________________________________ A Dissertation presented to the Faculty of the Graduate School at the University of Missouri-Columbia _______________________________________________________ In Partial Fulfillment of the Requirements for the Degree Doctor of Philosophy _____________________________________________________ by Julie Kay Wisch Dr. Noah D. Manring, Dissertation Adviser MAY 2016 The undersigned, appointed by the dean of the Graduate School, have examined the dissertation entitled DYNAMIC AND EFFICIENCY CHARACTERISTICS OF AN INLET METERING VALVE CONTROLLED FIXED DISPLACEMENT PUMP presented by Julie Wisch, a candidate for the degree of doctor of philosophy, and hereby certify that, in their opinion, it is worthy of acceptance. Professor Noah Manring Professor Roger Fales Professor Gary Solbrekken Professor Jacob McFarland Professor Steve Borgelt ACKNOWLEDGEMENTS I would like to thank my committee: Roger Fales, Gary Solbrekken, Jacob McFarland, and Steve Borgelt for their support in this endeavor. I would most especially like to thank Noah Manring, who has worked with me throughout this project, and devoted considerable time and attention to critically reviewing my work and pointing me in the right direction. I would also like to thank our partners at Caterpillar: Jeff Kuehn, Jeremy Peterson, Viral Mehta, Hongliu Du, and Randy Harlow for both the financial support and collective engineering experience that they contributed to this project. I am lucky to have had a team of engineers to brainstorm with, and am so grateful for the prototype they were able to provide. Thank you to Dr. Frank Feng, who was both an excellent mentor for my time as a teaching assistant, as well as the person who introduced me to another funding opportunity for my graduate studies via the Missouri Space Grant Consortium. Thank you to Doug Steinhoff, Karen King, Leon Schumacher, and Steve Borgelt who all facilitated opportunities for me to explore teaching and develop skills in that area. Finally, I would like to thank my parents, Kevin and Karen Wisch. They always show up for me, and I couldn’t ask for anything more. ii TABLE OF CONTENTS ACKNOWLEDGEMENTS ................................................................................................ ii LIST OF FIGURES .............................................................................................................v LIST OF TABLES ............................................................................................................ vii NOMENCLATURE ........................................................................................................ viii CHAPTER 1. INTRODUCTION ..........................................................................................1 Background and Motivation System Description Experimental Set Up Contribution Dissertation Outline 2. LITERATURE REVIEW .............................................................................11 Literature Review Introduction Inlet Metering Valves Hydraulic Systems, A Brief History A Comparison of Oil and Water Hydraulic Systems Cavitation Machine Design Considerations Entrained Air Fluid Modeling Justification Literature Conclusions 3. ANALYSIS ...................................................................................................26 Analysis Introduction Transient Pressure Analysis Pump Discharge Flow Pump Flow Phase I Pump Flow Phase II Pump Flow Phase III Pump Flow Phase IV Pump Flow Summary Inlet Metering Valve Valve Flow Force Considerations Flow Force Analysis Full Dynamic Valve Equation Summary of Dimensional Equations Nondimensionalization Variable Displacement Pump Model iii 4. EFFICIENCY ...............................................................................................50 Efficiency Introduction Traditional Pump Efficiency Inlet Metering Pump Efficiency Efficiency Model Validation Discussion of the Variable Displacement and Inlet Metering System 5. DESIGN AND MODELING ........................................................................72 Introduction to System Design and Modeling System Stability Design Criteria Development Solution of the System of Equations Dynamic System Response Design Process Illustrative Model Selection Modeling Introduction 6. RESULTS AND DISCUSSION ...................................................................89 Results Introduction Experimental Results System Efficiency Results Valve and Pressure Response Results Stability Discussion Design Parameter Adherence A Qualitative Discussion about the Inlet Metering System Efficiency System Dynamics Comparison Discussion of Valve Dynamic System Response 7. CONCLUSION ...........................................................................................119 Conclusion Introduction List of Conclusions Comparative Analysis Future Work REFERENCES ................................................................................................................128 APPENDIX ......................................................................................................................137 VITA ................................................................................................................................148 iv LIST OF FIGURES Figure Page 1-1. System design and associated nomenclature ...........................................................3 1-2. Spool valve...............................................................................................................4 1-3. Piston pump ............................................................................................................5 1-4. Test rig experimental set up ....................................................................................7 2-1. Diesel fuel injector diagram .................................................................................12 3-1. Piston pump ..........................................................................................................27 3-2. Strip chart illustrating piston pressure and displacement .....................................28 3-3. Inlet metering valve and associated nomenclature ...............................................37 3-4. Inlet metering valve free body diagram ................................................................41 3-5. Inlet metering valve flow at the outlet ..................................................................42 4-1. Variable displacement pump diagram ..................................................................51 4-2. Schematic of the pump, showing mass and volumetric flow rates .......................52 4-3. Inlet metering system control volume definition ..................................................57 4-4. Pressure as a Function of Crankshaft Position .....................................................58 4-5. Levenberg-Marquardt Solution Process ...............................................................67 5-1. Block diagram of the full order inlet metering valve system ...............................87 5-2. Block diagram of the reduced order inlet metering valve system ........................88 6-1. Inlet Metering System Experimental Set Up .........................................................90 6-2. Volumetric flow rate over time ............................................................................91 6-3. Averaged nondimensional discharge flow per position .......................................92 6-4. Averaged nondimensional discharge flow per position ........................................94 6-5. Averaged nondimensional discharge flow per position ........................................95 6-6. Comparison of fluid flow to valve position ...........................................................99 6-7. Torque requirement ............................................................................................100 6-8. Pump efficiency as a function of pump flow output ..........................................101 6-9. Inlet metering pump efficiency map ....................................................................102 6-10. Measured efficiency results for the inlet metering system ..................................103 6-11. Normalized Efficiency Comparison ....................................................................105 6-12. Normalized Efficiency Discrepancy ....................................................................106 6-13. Models A and A’ valve displacement ..................................................................108 6-14. Models A and A’ discharge pressure behavior ....................................................108 6-15. Models B and B’ valve displacement ..................................................................109 6-16. Models B and B’ discharge pressure behavior ....................................................109 6-17. Model A valve displacement over an extended time period ...............................110 6-18. Model B valve displacement over an extended time period ................................111 6-19. Magnified view of Models B and B’ pressure response ......................................112 6-20. Models A and A’ Bode Plot ................................................................................114 v 6-21. Models B and B’ Bode Plot .................................................................................114 6-22. Models A and A’ Step Response Plot .................................................................116