Geothermal Heat Pump and Heat Engine Systems

A unique approach to the study of geothermal energy systems

This book takes a unique, holistic approach to the interdisciplinary study of geothermal energy systems, combining low, medium, and high temperature applications into a logical order. The emphasis is on the concept that all geothermal projects contain common elements of a "thermal energy reservoir" that must be properly designed and managed.

The book is organized into four sections that examine geothermal systems: energy utilization from resource and site characterization; energy harnessing; energy conversion (heat pumps, direct uses, and heat engines); and energy distribution and uses.

Examples are provided to highlight fundamental concepts, in addition to more complex system design and simulation.

Key features:

• Companion website containing software tools for application of fundamental principles and solutions to real-world problems.

• Balance of theory, fundamental principles, and practical application.

• Interdisciplinary treatment of the subject matter.

Geothermal Heat Pump & Heat Engine Systems: Theory and Practice is a unique textbook for Energy Engineering and Mechanical Engineering students as well as practicing engineers who are involved with low-enthalpy geothermal energy systems.

Autorentext

Andrew Chiasson is a faculty member in the Department of Mechanical & Aerospace Engineering, University of Dayton, where he teaches courses and conducts research in the areas of thermofluid sciences, and renewable and clean energy. He has academic and professional practice experience in a wide range of geothermal and hydrogeologic applications related to geothermal heat pumps (geoexchange), direct-use geothermal, small-scale electrical power generation, hydrogeological site evaluations, and groundwater flow and mass/heat transport modeling. Dr. Chiasson has been extensively involved in research and development of design and simulation tools for optimal earth heat exchanger coupling, hybrid geoexchange systems, and underground solar energy storage. As a Professional Engineer in the United States and in Canada, he has designed numerous closed and open-loop geoexchange systems and HVAC systems for a wide variety of building types. He is a member of ASHRAE Technical Committees and is an IGSHPA Accredited Ground Source Heat Pump Trainer.

Zusammenfassung

A unique approach to the study of geothermal energy systems

This book takes a unique, holistic approach to the interdisciplinary study of geothermal energy systems, combining low, medium, and high temperature applications into a logical order. The emphasis is on the concept that all geothermal projects contain common elements of a "thermal energy reservoir" that must be properly designed and managed.

The book is organized into four sections that examine geothermal systems: energy utilization from resource and site characterization; energy harnessing; energy conversion (heat pumps, direct uses, and heat engines); and energy distribution and uses.

Examples are provided to highlight fundamental concepts, in addition to more complex system design and simulation.

Key features:

• Companion website containing software tools for application of fundamental principles and solutions to real-world problems.
• Balance of theory, fundamental principles, and practical application.
• Interdisciplinary treatment of the subject matter.
  Geothermal Heat Pump & Heat Engine Systems: Theory and Practice is a unique textbook for Energy Engineering and Mechanical Engineering students as well as practicing engineers who are involved with low-enthalpy geothermal energy systems.

Inhalt

Series Preface xiv

Preface xv

About the Companion Website xviii

1 Geothermal Energy Project Considerations 1

1.1 Overview 1

1.2 Renewable/Clean Energy System Analysis 1

1.3 Elements of Renewable/Clean Energy Systems 4

1.4 Geothermal Energy Utilization and Resource Temperature 5

1.5 Geothermal Energy Project History and Development 5

1.6 Chapter Summary 18

Discussion Questions and Exercise Problems 19

Part I Geothermal Energy Utilization and Resource Characterization 21

2 Geothermal Process Loads 23

2.1 Overview 23

2.2 Weather Data 24

2.3 Space Heating and Cooling Loads 26

2.4 Hot Water Process Loads 38

2.5 Swimming Pool and Small Pond Heating Loads 40

2.6 Snow-Melting Loads 46

2.7 Chapter Summary 53

Discussion Questions and Exercise Problems 54

3 Characterizing the Resource 55

3.1 Overview 55

3.2 Origin and Structure of the Earth 56

3.3 Geology and Drilling Basics for Energy Engineers 59

3.4 Earth Temperature Regime and Global Heat Flows: Why is the Center of the Earth Hot? 62

3.5 Shallow Earth Temperatures 64

3.6 The Geothermal Reservoir Concept 66

3.7 Geothermal Site Suitability Analysis 68

3.8 Chapter Summary 79

Discussion Questions and Exercise Problems 80

Part II Harnessing the Resource 81

4 Groundwater Heat Exchange Systems 83

4.1 Overview 83

4.2 Why Groundwater? 84

4.3 Theoretical Considerations 85

4.4 Practical Considerations 108

4.5 Groundwater Heat Pump Systems 123

4.6 Chapter Summary 134

Discussion Questions and Exercise Problems 135

5 Borehole Heat Exchangers 138

5.1 Overview of Borehole Heat Exchangers (BHEs) 138

5.2 What is a Borehole Heat Exchanger? 139

5.3 Brief Historical Overview of BHEs 140

5.4 Installation of BHEs 141

5.5 Thermal and Mathematical Considerations for BHEs 142

5.6 Thermal Response Testing 169

5.7 Pressure Considerations for Deep Vertical Boreholes 175

5.8 Special Cases 176

5.9 Chapter Summary 178

Discussion Questions and Exercise Problems 179

6 Multi-Borehole Heat Exchanger Arrays 181

6.1 Overview 181

6.2 Vertical GHX Design Length Equation and Design Parameters 184

6.3 Vertical GHX Simulation 198

6.4 Hybrid Geothermal Heat Pump Systems 199

6.5 Modeling Vertical GHXs with Software Tools 200

6.6 Chapter Summary 216

Discussion Questions and Exercise Problems 217

7 Horizontal Ground Heat Exchangers 219

7.1 Overview 219

7.2 Horizontal GHX Design Length Equation and Design Parameters 221

7.3 Modeling Horizontal GHXs with Software Tools 232

7.4 Simulation of Horizontal GHXs 237

7.5 Earth Tubes 238

7.6 Chapter Summary 244

Discussion Questions and Exercise Problems 244

8 Surface Water Heat Exchange Systems 246

8.1 Overview 246

8.2 Thermal Processes in Surface Water Bodies 247

8.3 Open-Loop Systems 250

8.4 Closed-Loop Systems 251

8.5 Chapter Summary 266

Discussion Questions and Exercise Problems 266

9 Opportunistic Heat Sources and Sinks 267

9.1 Overview 267

9.2 Use of Existing Water Wells 267

9.3 Heat Exchange With Building Foundations 268

9.4 Utilization of Infrastructure from Other Energy Sectors 268

9.5 Cascaded Loads and Combined Heat and Power (CHP) 271

9.6 Integrated Loads and Load Sharing with Heat Pumps 273

9.7 Chapter Summary 278

Discussion Questions and Exercise Problems 279 **10 Piping and P...