Condensation heat transfer has been extensively applied across various fields, including aerospace, chemical industry, and power generation. Air is invariably present in condensation systems, making the condensation heat transfer of vapor in the presence of air a long-standing and intriguing topic. In this book, we present a comprehensive review of the condensation heat transfer of vapor interacting with air within or over smooth tubes, and heat pipe systems. As a practical example, we thoroughly elucidated the condensation heat transfer of vapor with air across a horizontal tube. Four types of investigations were presented: (1) three-field synergy in steam condensation in the presence of air, (2) air accumulation in a condensation space, (3) air adsorption during condensation with air drainage, and (4) the effects of stagnant air on vapor condensation. We proposed a computational model based on a set of two-dimensional momentum and energy conservation equations to address the three-field synergy in vapor condensation with air. Five experimental setups were clarify the characteristics of air accumulation, air adsorption, and stagnant air. We described the calculation methods for various parameters, including the coordinated angles among the three fields, the thickness of the gas-film layer and condensate, the induced velocity, the shear stress at the gas-liquid interface, the vapor flow front, the ratio of the gas-film layer to overall thermal resistance, the air mole fraction, theheat transfer coefficients, the relative air content, the ending temperature difference, the Nusselt number, the amount of air adsorption at the gas-liquid interface, and the Reynolds number of the condensate. Additionally, we analyzed the influences of several factors, such as air mole or mass fractions, mainstream velocity, circumferential angle, pressure, temperature, mass flux of cooling water, and mass flux of vapor. We compared and evaluated experimental data and calculated results from various references. Notably, the condensation heat transfer of vapor with air in a heat pipe was also presented. Through this research, readers can gain insights into the thermodynamic characteristics of air in various condensation systems and the effects of air on steam condensation under diverse parameters and conditions.
Table of Contents
Chapter 1 Introduction 001
1.1 Progress of the three-field synergy theory 002
1.2 Condensation in the presence of non-condensable gas across a horizontal tube 003
1.3 Condensation in the presence of non-condensable gas in the tube 008
1.4 Condensation in the presence of non-condensable gas in a heat pipe 013
Chapter 2 Condensation heat transfer of vapor/air across a horizontal tube 019
2.1 Numerical study on the three-field synergy in condensation of vapor with air 020
2.2 Experimental designation on condensation across a horizontal tube 034
2.3 Air accumulation in the condensation of vapor 055
2.4 Air adsorption on the gas-liquid interface 067
2.5 Effects of stagnant air on condensation heat transfer 078
Chapter 3 Condensation heat transfer of vapor/air in the tube 091
3.1 Problem statements 092
3.2 Mode method 093
3.3 Condensation heat transfer of vapor/air in the vertical tube 096
3.4 Pure vapor condensation in a horizontal tube 101
3.5 Condensation heat transfer of vapor/air in a tilted tube 107
3.6 Conclusions 109
Chapter 4 Condensation heat transfer of vapor/air in the heat pipe 111
4.1 Theoretical study on heat pipe used for waste heat recovery of air-conditioning 112
4.2 Effect of air on condensation in a non-vacuum gravity heat pipe 127
Chapter 5 Direct contact condensation heat transfer of steam with air in a venturi tube 147
5.1 Mathematical model 148
5.2 Numerical solution 154
5.3 Model verification 156
5.4 Effect of convergent angle 157
5.5 Effect of the vapor pressure 161
5.6 Effects of NCG mass fraction 163
5.7 Effects of initial parameters of the falling water column 165
5.8 Condensation length of vapor 170
5.9 Conclusions 172
Nomenclature 174
References 181
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Condensation Heat Transfer Performance of Steam in the Presence of Non-condensable Gas
