Solar energy has found its widespread use in direct conversion into electricity either by photovoltaic conversion or through thermal energy, reduction in post-harvest losses, and crop drying. Solar Drying Systems analyzes the fundamentals, principles and applications, heat transfer, elements of drying and solar dryer designs, and related modeling and analysis aspects of solar energy.
- Discusses both technical and policy related issues
- Explores up-to-date status reviews of different solar drying systems
- Reviews the highlights of present and future solar drying options
- Includes many figures, solved examples, and tables with problems/exercises at the end of each chapter
This book is aimed at senior undergraduate and graduate students in energy engineering.
Author(s): Om Prakash, Anil Kumar
Publisher: CRC Press
Year: 2020
Language: English
Pages: 154
City: Boca Raton
Cover
Half Title
Title Page
Copyright Page
Table of Contents
Foreword by Rebecca R. Milczarek
Preface
Acknowledgments
Authors
Chapter 1: Fundamentals of Solar Drying Systems
1.1 Introduction
1.2 Importance of Drying
1.3 Crop Drying Characteristics
1.4 Safe Moisture Content
1.5 Dried Product Quality Parameters
1.6 Classification of Drying
1.7 Introduction to Solar Drying
Problems
References
Chapter 2: Drying Methodology
2.1 Introduction
2.2 Moisture Content
2.3 Moisture Movement Mechanism
2.4 Equilibrium Moisture Content (EMC)
2.4.1 EMC Models
2.4.1.1 Henderson Equation
2.4.1.2 Chung–Pfost Equation
2.4.1.3 Modified Halsey Equation
2.4.1.4 Modified Oswin Equation
2.5 Drying Theory
2.6 Drying Rate Equation
2.6.1 Constant Drying Rate Period
2.6.2 Falling Drying Rate Period
2.7 Shrinkage
2.7.1 Shrinkage Model
2.7.2 Volume Shrinkage
2.7.3 Bulk Density
2.7.4 Particle Density
2.7.5 Dry Solids Density
2.7.6 Equilibrium Density
2.7.7 Porosity
2.8 Pretreatments for Drying
2.8.1 Pretreatment of Vegetables
2.8.2 Pretreatment of Fruit
Problems
References
Chapter 3: Various Designs of Solar Drying Systems
3.1 Introduction
3.1.1 Open Sun Drying (OSD)
3.1.2 Direct Solar Drying (DSD)
3.1.3 Indirect Solar Drying (ISD)
3.2 Classification of Solar Dryers
3.3 Passive Solar Dryers
3.3.1 Direct Passive Solar Dryers
3.3.2 Cabinet Dryers
3.3.2.1 Normal Absorber Cabinet Dryer
3.3.2.2 Reverse Absorber Cabinet Dryer (RACD)
3.3.3 Greenhouse Dryers
3.3.3.1 Definition of Greenhouse Effect
3.3.4 Indirect Passive Solar Dryers
3.3.5 Mixed Mode Passive Solar Dryers
3.4 Active Solar Dryers
3.4.1 Direct Active Solar Dryers
3.4.2 Indirect Active Solar Dryers
3.4.3 Mixed Mode Active Solar Dryers
3.5 Hybrid Solar Dryers
3.6 Innovations in Solar Dryers
3.7 Miscellaneous Design Solar Dryer
Problems
References
Chapter 4: Performance Analysis of Solar Drying Systems
4.1 Introduction
4.2 Drying Efficiency
4.3 Coefficient of Performance
4.4 Thermal Efficiency
4.5 Overall Daily Thermal Efficiency
4.6 Exergy Analysis
4.7 Exergy Analysis of Various Solar Dryers
4.8 Testing Procedure of Solar Dryers in Load and No-Load Conditions
4.8.1 Load Condition
4.8.2 No-Load Condition
4.9 Discussion
4.10 Performance Characteristics of Various Solar Dryers
Problems
References
Chapter 5: Thermal Modeling of Solar Drying Systems
5.1 Introduction
5.2 Convective Heat and Mass Transfer
5.2.1 Convective Heat Transfer
5.2.2 Convective Mass Transfer
5.3 Modeling Procedure for Convective Heat Transfer (CHT)
5.3.1 Case I: Natural Convection
5.3.2 Case II: Forced Convection
5.4 Thermal Modeling of Various Types of Dryers
5.4.1 Thermal Modeling of Open Sun Drying
5.4.1.1 Crop Surface
5.4.1.2 Moist Air above the Crop
5.4.1.3 Analysis for Steady State Condition
5.4.2 Thermal Modeling of Greenhouse Drying Systems (TMGDS)
5.4.2.1 Greenhouse Dryers under Natural Convection Mode
5.4.2.2 Solution of the Thermal Model for Greenhouse Dryers under Passive Mode
5.4.2.3 Greenhouse Dryers under Forced Convection Mode
5.4.2.4 Solution of the Thermal Model
5.4.3 Thermal Modeling of Indirect Solar Drying (ISD) Systems
5.4.3.1 Solar Air Heater
5.4.3.2 Drying Chamber
5.5 Statistical Parameters
5.5.1 Root Mean Square Deviation/Root Mean Square Error
5.5.2 Coefficient of Correlation ( r)
5.5.3 Coefficient of Determination
5.5.4 Sum of Squared Errors
5.5.5 Root Mean Square Error (RMSE)
5.5.6 Mean Percentage Error (MPE)
5.5.7 Mean Square Error (MSE)
5.5.8 Adjusted R 2 (R 2)
5.5.8.1 Case Study
Problems
References
Chapter 6: Energy Analysis of Solar Drying Systems
6.1 Introduction
6.2 Embodied Energy of Different Prominent Materials
6.3 Energy Payback Time
6.4 CO 2 Emissions
6.5 Earned Carbon Credit
6.6 Energy Analysis of Various Solar Dryers
6.7 Energy Efficiency of Solar Drying Systems
6.7.1 Case Study 1: Direct Solar Dryer
6.7.2 Case Study 2: Indirect Solar Dryer
6.7.3 Case Study 3: Mixed Solar Dryer
Problems
Nomenclature
References
Chapter 7: Economic Analysis of Solar Drying Systems
7.1 Introduction
7.2 Cost Analysis
7.2.1 Capital Recovery Factor (CRF)
7.2.2 Uniform Annualized Cost (UAC)
7.2.3 Sinking Fund Method (SFM)
7.3 Cash Flow
7.4 Payback Time
7.5 Benefit–Cost (B/C) Ratio
7.5.1 Advantages and Limitations of the B/C Ratio
7.5.2 Shortcomings of the B/C Ratio
7.6 Effect of Depreciation
7.7 Annual Cost Method
7.8 Economic Analysis of Various Solar Dryers
7.8.1 Direct Solar Dryers
7.8.2 Mixed Mode Solar Dryers
7.8.3 Indirect Solar Dryers
Problems
References
Appendix: The Microsoft Excel Templates
Index
