HEAT AND MASS TRANSFER FOR THE DIFFUSION …

1 heat AND mass TRANSFER FOR THE DIFFUSION driven DESALINATION PROCESS By YI LI A DISSERTATION PRESENTED TO THE GRADUATE SCHOOL OF THE UNIVERSITY OF FLORIDA IN PARTIAL FULFILLMENT OF THE REQUIREMENTS FOR THE DEGREE OF DOCTOR OF PHILOSOPHY UNIVERSITY OF FLORIDA 2006 Copyright 2006 by YI LI This dissertation is dedicated with love and gratitude to my family. Without their love, support and faith in me, this accomplishment would not have been possible. iv ACKNOWLEDGMENTS My appreciation and respect go to my advisor, Professor James Klausner, for introducing me to the field of multiphase flow and for giving me the opportunity to study heat and mass TRANSFER dynamics for my dissertation.

2 His continuous support and patience helped me to achieve this work. I would like to express my special thanks to Professor Renwei Mei for his help and encouragement in my study of turbulence and numerical analysis. I sincerely thank my committee members for their comments and help. I would like to thank all my colleagues, in particular Jessica Knight and Jun Liao. I also extend my thanks to the individuals in the department who have helped me in one way or another during my graduate studies.

3 I would like to acknowledge the support of the Department of Energy under Award No. DE-FG26-02NT41537 for this research. I also thank the University of Florida for the financial assistance through the UF Alumni Fellowship I was awarded for the academic years 2003-2006. Finally, I would like to thank my family for their continuous support and encouragement through the years of my studies. To them, I dedicate this dissertation. v TABLE OF CONTENTS page ACKNOWLEDGMENTS.

4 Iv LIST OF TABLES ..viii LIST OF ix NOMENCLATURE ..xiii xvi CHAPTER 1 INTRODUCTION AND LITERATURE REVIEW .. 1 Description of Thermal Desalting and Membrane Separation .. 2 Description of HDH and MEH 4 Description of DDD 6 Comparison of the DDD Process with HDH and MEH .. 8 Comparison of the DDD Process with MSF and RO .. 10 Potential Applications for the DDD Process .. 12 Properties of Saline Water .. 17 Objectives of the 21 Scope of 21 2 THERMODYNAMIC ANALYSIS OF THE DDD PROCESS .. 23 Mathematic Model .. 23 Computation Results and 26 3 EXPERIMENTAL 35 Experimental System Description.

5 35 Experimental Facility and 38 4 heat AND mass TRANSFER FOR THE DIFFUSION 48 heat and mass TRANSFER Model for the DIFFUSION Tower .. 48 Model Comparison with Experiments for the DIFFUSION Tower .. 57 Pressure Drop through the Packing Material .. 60 vi Optimization of the Packing Material .. 61 5 heat AND mass TRANSFER FOR THE DIRECT CONTACT CONDENSER 73 Mathematical Model of the Packed Bed Direct Contact 75 Model Comparison with Experiments for the Packed Bed Direct Contact Condenser .. 82 Wetting Phenomena within Packed 87 Experimental Results of the Droplet Direct Contact Condenser.

6 90 Condenser 95 6 DDD PROCESS OPTIMIZATION DESIGN AND ECONOMIC 98 Mathematical 99 Computation Results and 101 Economic Analysis .. 111 7 CONCLUSIONS .. 119 APPENDIX A ONDA S CORRELATION ..122 B EXPERIMENTAL DATA OF THE DIFFUSION 123 C EXPERIMENTAL DATA OF THE AIR SIDE PRESSURE DROP THROUGH THE PACKING MATERIAL .. 125 D EXPERIMENTAL DATA OF THE COUNTERCURRENT FLOW DIRECT CONTACT CONDENSER STAGE WITH PACKED BED .. 126 E EXPERIMENTAL DATA OF THE CO-CURRENT FLOW DIRECT CONTACT CONDENSER STAGE WITH PACKED BED.

7 128 F EXPERIMENTAL DATA OF THE DROPLET DIRECT CONTACT CONDENSERS WITH CO-CURRENT AND COUNTERCURRENT FLOW .. 129 G EXPERIMENTAL DATA OF THE DROPLET DIRECT CONTACT CONDENSER STAGE WITH COUNTERCURRENT 132 H UNCERTAINTY ANALYSIS OF THE FLUID PROPERTIES .. 133 Theory of Uncertainty .. 133 Uncertainty of the Calculated Fluid Properties .. 134 Uncertainty of the mass and heat TRANSFER Coefficients .. 141 Results and 144 LIST OF 151 vii BIOGRAPHICAL SKETCH .. 155 viii LIST OF TABLES Table page 1-1 Pumping and heating energy consumption of some desalination processes.

8 4 1-2 Comparison of electricity consumption for DDD, MSF, and RO desalination technologies .. 10 1-3 Comparison of advantages and disadvantages of DDD, RO, and MSF desalination 11 4-1 Packing material configurations .. 63 6-1 Summary of direct costs .. 114 6-2 Details of cost calculations .. 114 ix LIST OF FIGURES Figure page 1-1 Schematic diagram of mechanical vapor compression process .. 2 1-2 Schematic diagram of thermal vapor compression combined multi-effect destillation process .. 3 1-3 Schematic diagram for DIFFUSION driven desalination 7 1-4 Depth to saline ground water in the United States [18].

9 13 1-5 Flow diagram of DDD process driven by solar 14 1-6 Flow diagram of DDD process driven by geothermal energy .. 15 2-1 Flow diagram for DIFFUSION driven desalination 23 2-2 Rate of entropy generation for different exit brine temperature, Th=27 C .. 27 2-3 Variation of exit brine temperature with exit air temperature, Th=27 C .. 28 2-4 Fresh water production efficiency, Th=27 C .. 28 2-5 Rate of entropy generation for different exit brine temperature: a) Th=50 C, b) Th=80 29 2-6 Variation of exit brine temperature with exit air temperature: a) Th=50 C, b) Th=80 30 2-7 Fresh water production efficiency: a) Th=50 C, b) Th=80 C.

10 32 2-8 Rate of energy consumption: a) Th=50 C, b) Th=80 33 2-9 Minimum rate of energy consumption for different 34 3-1 Pictorial view of the laboratory scale DDD experiment .. 36 3-2 Schematic diagram of laboratory scale DDD facility .. 37 3-3 Schematic diagram of experimental DIFFUSION tower .. 39 x 3-4 Schematic diagram of experimental direct contact condenser .. 40 3-5 Pictorial view of spray 41 3-6 Pictorial view of packing 42 3-7 Schematic diagram of the instrumentation system for the DDD experiment.