FLUCTUATIONS IN ASHRAE HANDBOOK REFRIGERANT PHYSICAL PROPERTIES AND THE EFFECT ON SINGLE AND TWO PHASE FLOW A Thesis by PAUL HENRY NAGY Submitted to the Office of Graduate and Professional Studies of Texas A&M University in partial fulfillment of the requirements for the degree of MASTER OF SCIENCE Chair of Committee, Michael Pate Committee Members, Jorge Alvarado Partha Mukherjee Head of Department, Andreas Polycarpou December 2014 Major Subject: Mechanical Engineering Copyright 2014 Paul Nagy ABSTRACT Throughout the course of the American Society of Heating Refrigeration and Air Conditioning, data of refrigerant physical properties have been published in their Handbooks. However, this information is not constant, rather varying as each subsequent handbook edition is released. Thirteen properties (liquid and vapor viscosity, thermal conductivity, specific heat, enthalpy, surface tension, density and specific volume) from five widely used refrigerants (R-22, R-134a, R-410a, R-152a, R-600a) are examined at temperatures of 100 and 40 degrees Fahrenheit. Also, standard correlations to design variables such as effect on Reynolds number are obtained using these properties. Mass flux rates of 100 and 300 lbm/ft2-s are considered with pipe diameter of 8.52mm. The resultant values are compared to 2013, the most recent ASHRAE Handbook edition, as well as between editions beginning in 1981 in a standard percent change format. It is seen that physical properties can vary by nearly 30% with respect to edition 2013 and up to 25% between editions with a stabilizing effect appearing near more current editions. Additionally, design variables showed a similar trend however, as equations became a function of more physical properties, percent change became more erratic. With regards to mass flux rate, percent change was not affected for the selected single phase design variables as mass flux increased due to a scaling factor response, yet at lower mass flux pipe friction factor could be affected. Two phase flow calculations resulted in R-600a showing discrepancies of nearly plus and minus 50 percent through the quality range of 0.2 to 0.8 for condensation and ii plus 15 percent to negative 20 percent for qualities of 0.2 and 0.8, respectively. R-22 showed the lowest error with R-152a revealing at times negative 40 percent error for condensation and plus 7 percent error for evaporation. iii DEDICATION This thesis is dedicated to my mom and my dad for their love and support every step of the way. iv ACKNOWLEDGEMENTS First and foremost I would like to thank Dr. Pate for his guidance and giving me the opportunity to work on this thesis. I would also like to thank Dr. Alvarado and Dr. Mukherjee for being on my committee. A big thank you to Jason Korn for assisting me with the proof reading and helping throughout the entire process, I couldn’t have done it without you. Also I would like to acknowledge my brother, Phillip Nagy for helping through the proofing process and putting up with the late nights. Lastly, thank you to Yuliang Ji for helping with the two phase calculations. v NOMENCLATURE ASHRAE American Society of Heating Refrigerating & Air Conditioning Engineers ASHAE American Society of Heating & Air Conditioning Engineers ASRE American Society of Refrigerating Engineers ASME American Society of Mechanical Engineers ASH&VE American Society of Heating & Ventilating Engineers HVAC Heating Ventilation & Air Conditioning EPA Environmental Protection Agency GWP Global Warming Potential ODP Ozone Depletion Potential IPCC Intergovernmental Panel on Climate Change µ Viscosity, 푙푏푚/(푓푡 ∙ ℎ푟) κ Thermal Conductivity, 퐵푡푢/(푓푡 ∙ ℎ푟 ∙ 퐹) ρ Density, 푙푏푚/푓푡3 hf Liquid Enthalpy, 퐵푡푢/푙푏 hg Vapor Enthalpy, 퐵푡푢/푙푏 V Velocity, 푓푡/푠 D Diameter,푓푡, 푚푚 Re Reynolds Number Nu Nusselt Number vi Pr Prandtl Number G Mass Flux, 푙푏푚/(푓푡2 ∙ 푠) 2 Pr Reduced Pressure, 푙푏푓/푛 Cp Specific Heat, 퐵푡푢/(푙푏푚 ∙ 퐹) h Heat Transfer Coefficient, 퐵푡푢/(푓푡2 ∙ ℎ푟 ∙ 퐹) f Friction Factor P Pressure, 푙푏푓/푛2 x Quality 2 hTP Two Phase Heat Transfer Coefficient, 푊/(푚 ∙ 퐾) 2 hLT Liquid Heat Transfer Coefficient, 푊/(푚 ∙ 퐾) Fr Froude Number Ffl Fluid Dependent Parameter Bo Boiling Number Co Convection Number vii TABLE OF CONTENTS Page ABSTRACT .......................................................................................................................ii DEDICATION .................................................................................................................. iv ACKNOWLEDGEMENTS ............................................................................................... v NOMENCLATURE .......................................................................................................... vi TABLE OF CONTENTS ............................................................................................... viii LIST OF FIGURES ............................................................................................................ x LIST OF TABLES ......................................................................................................... xiii 1. INTRODUCTION .......................................................................................................... 1 1.1 Problem Overview ................................................................................................ 1 1.2 Problem Validation ............................................................................................... 2 2. BACKGROUND AND HISTORY ................................................................................ 3 2.1 History of ASHRAE ............................................................................................. 3 2.2 ASHRAE Handbook ............................................................................................ 4 2.3 Refrigerant Background ....................................................................................... 5 3. DATA ANALYSIS METHODOLOGY ........................................................................ 9 3.1 Overview .............................................................................................................. 9 3.2 Method .................................................................................................................. 9 3.3 R-410a Interpolation ........................................................................................... 10 3.4 Data Organization and Trends ............................................................................ 11 3.5 Data Percent Change .......................................................................................... 14 4. PHYSICAL PROPERTIES .......................................................................................... 18 4.1 Preface ................................................................................................................ 18 4.2 Viscosity ............................................................................................................. 18 4.3 Thermal Conductivity ......................................................................................... 21 4.4 Enthalpy .............................................................................................................. 25 4.5 Summary ............................................................................................................ 29 viii 5. SINGLE PHASE FLOW CORRELATIONS .............................................................. 32 5.1 Reynolds Number ............................................................................................... 32 5.2 Prandtl Number .................................................................................................. 39 5.3 Nusselt Number .................................................................................................. 46 5.4 Heat Transfer Coefficient ................................................................................... 52 5.5 Darcy Friction Factor ......................................................................................... 58 5.6 Pressure Drop ..................................................................................................... 64 5.7 Limitations of Results ........................................................................................ 69 6. TWO PHASE FLOW CORRELATIONS ................................................................... 71 6.1 Key Differences .................................................................................................. 71 6.2 Condensation ...................................................................................................... 71 6.3 Evaporation ........................................................................................................ 78 7. CONCLUSIONS .......................................................................................................... 86 REFERENCES ................................................................................................................. 87 APPENDIX A .................................................................................................................. 90 APPENDIX B .................................................................................................................. 92 APPENDIX C ................................................................................................................ 110 ix LIST OF FIGURES Page Figure 1: Saturated Liquid Viscosity Trend 40 Degrees Fahrenheit ................................ 13 Figure 2: Saturated Liquid Viscosity