除湿剂超声波再生技术

About the Authors

Preface

Acknowledgements

Nomenclature

1 Introduction

1．1 Background

1．2 Literature Reviews

1．2．1 Desiccant Materials

1．2．2 Types of Desiccant Dryer

1．2．3 Regeneration Methods

1．3 The Proposed Method

1．3．1 Basic Knowledge about Ultrasound

1．3．2 Sound Generation

1．3．3 Fundamental Theory for Ultrasound-Assisted Regeneration

1．4 Summary

References

2 Ultrasound-Assisted Regeneration of Silica Gel

2．1 Theoretical Analysis

2．2 Experimental Study

2．2．1 Experimental Setup

2．2．2 Procedure for Experiments

2．2．3 Methods

2．2．4 Results and Discussions

2．3 Empirical Models for Ultrasound-Assisted Regeneration

2．3．1 Model Overviews

2．3．2 Model Analysis

2．4 Theoretic Model for Ultrasound-Assisted Regeneration

2．4．1 Physical Model

2．4．2 Mathematical Model for Ultrasonic Wave Propagation

2．4．3 Mathematical Model for Heat and Mass Transfer in Silica Gel Bed

2．4．4 Model Validation

2．4．5 Error Analysis for Experimental Data

2．5 Parametric Study on Silica Gel Regeneration Assisted by Ultrasound

2．5．1 Acoustic Pressure and Oscillation Velocity in the Packed Bed

2．5．2 Thermal Characteristics of the Bed during Ultrasound-Assisted Regeneration

2．5．3 Enhancement of Regeneration Assisted by Ultrasound

2．5．4 Comparisons between the Transverse- and Radial-Flow Beds

2．6 Quantitative Contribution of Ultrasonic Effects to Silica Gel Regeneration

2．6．1 Theoretical Analysis

2．6．2 Method

2．6．3 Results and Discussions

2．7 Energy-Saving Features of Silica Gel Regeneration Assisted by Ultrasound

2．7．1 Specific Energy Consumption

2．7．2 Results and Discussions

2．7．3 Brief Summary

2．8 Effects of Ultrasound-Assisted Regeneration on Desiccant System Performance

2．8．1 Study Objective and Method

2．8．2 Results and Discussions

2．8．3 Brief Summary

References

3 Ultrasound-Assisted Regeneration for a New Honeycomb Desiccant Material

3．1 Brief Introduction

3．2 Experimental Study

3．2．1 Experimental System

3．2．2 Raw Material and Experimental Conditions

3．2．3 Analysis Parameters

3．2．4 Experimental Results

3．2．5 Energy Attenuation and Absorptivity of Ultrasound in the Material

3．3 Theoretical Model for Honeycomb-Type Desiccant Regeneration

3．3．1 Basic Assumptions

3．3．2 Governing Equations

3．3．3 Determination of Key Parameters

3．3．4 Model Validation

3．4 Model Simulations and Analysis

3．4．1 Parametric Study

3．4．2 Quantitative Contributions of Ultrasonic Effects to the Regeneration of Honeycomb-Type Desiccant

3．5 Summary

References

4 Ultrasound-Atomizing Regeneration for Liquid Desiccants

4．1 Overview

4．1．1 Principles and Features of the Liquid-Desiccant Dehumidification

4．1．2 Thermo-Physical Properties of Liquid Desiccant Materials

4．1．3 Research Status of Solution Regenerators

4．2 Theoretical Analysis

4．2．1 Mass Transfer Coefficients for the Droplets

4．2．2 Atomized Size of Droplet by Ultrasonic Atomizing

4．2．3 Droplet Distribution Characteristics and Measurement Techniques

4．2．4 Vapor Pressure of Liquid Desiccant Mixture

4．3 Theoretical Modeling for the Ultrasound-Atomizing Regenerator

4．3．1 Assumptions

4．3．2 Basic Equations

4．3．3 Determination of Key Parameters

4．3．4 Model Validation

4．3．5 Parametric Study

4．4 Performance Analysis of Liquid-Desiccant Dehumidification System with Ultrasound-Atomizing Regeneration

4．4．1 The Ultrasound-Atomizing Regenerator versus the Packed One

4．4．2 Performance of Liquid Desiccant System with Different Regenerators

References

5 Ultrasonic Transducers

5．1 Longitudinal Vibration of Sandwich Piezoelectric Ultrasonic Transducer

5．1．1 Overview

5．1．2 Theoretical Analysis

5．1．3 State Equations of Sandwich Piezoelectric Electromechanical Transducer

5．1．4 Design Case

5．2 Radial Vibration Ultrasonic Transducer

5．2．1 Overview

5．2．2 Theoretical Analysis and Design of a Binary Radial Transducer

5．2．3 Radial Vibration Sandwich Piezoelectric Transducer

5．2．4 Summary

5．3 Ultrasonic Atomization Transducer

5．3．1 Basic Principle of Ultrasonic Atomization

5．3．2 Basic Structure of Ultrasonic Atomizers

5．3．3 Research Status and Applications

References

6 Desiccant System with Ultrasonic-Assisted Regeneration

6．1 For Solid-Desiccant System

6．1．1 Based on the Longitudinal Vibration Ultrasonic Transducer

6．1．2 Based on the Radial Vibration Ultrasonic Transducer

6．2 For Liquid-Desiccant System

6．3 Future Work

6．3．1 Development of Ultrasonic Transducer

6．3．2 Development of Desiccant Materials Adaptive to Ultrasound-Assisted Regeneration

6．3．3 Development of Demister

6．3．4 Environmental Impact

References

Appendix A Basic Equations for Properties of Common Liquid Desiccants

A．1 Lithium Chloride (LiC1)

A．2 Calcium Chloride (CaC12)

A．3 Lithium Bromide (LiBr)

A．4 Vapor Pressure (Pa)

A．5 Specific Thermal Capacity (J/(kg．℃))

A．6 Density (kg/m3)

A．7 Dynamic Viscosity (Pa s)

References

Index