COMBINED COOLING, HEATING, AND POWER SYSTEMS

Contents List of Figures xiii List of Tables xvii Series Preface xix Preface xxi Acknowledgment xxiii Acronyms xxv Symbols xxvii Introduction xxxiii 1 State-of-the-Art of Combined Cooling, Heating, and Power (CCHP) Systems 1 1.1 Introduction 1 1.2 Prime Movers 4 1.2.1 Reciprocating IC Engines 4 1.2.2 Combustion Turbines 6 1.2.3 Steam Turbines 6 1.2.4 Micro-turbines 7 1.2.5 Stirling Engines 9 1.2.6 Fuel Cells 10 1.3 Thermally Activated Technologies 11 1.3.1 Absorption Chillers 13 1.3.2 Adsorption Chillers 15 1.3.3 Desiccant Dehumidifier 16 1.4 System Configuration 17 1.4.1 Micro-Scale CCHP Systems 17 1.4.2 Small-Scale CCHP Systems 20 x Contents 1.4.3 Medium-Scale CCHP Systems 22 1.4.4 Large-Scale CCHP Systems 23 1.5 System Management, Optimization, and Sizing 25 1.5.1 Conventional Operation Strategies 25 1.5.2 Novel Operation Strategies 25 1.5.3 System Optimization 27 1.5.4 Sizing 30 1.6 Development and Barriers of CHP/CCHP Systems in Representative Countries 32 1.6.1 The United States 32 1.6.2 The United Kingdom 33 1.6.3 The People’s Republic of China 35 1.7 Summary 37 References 38 2 An Optimal Switching Strategy for Operating CCHP Systems 49 2.1 Introduction and Related Work 49 2.2 Conventional Operation Strategies of CCHP Systems 51 2.2.1 FEL Mode of the CCHP System 52 2.2.2 FTL Mode of the CCHP System 53 2.3 EC Function and the Optimal Switching Operation Strategy 54 2.3.1 PEC 54 2.3.2 CDE 55 2.3.3 COST 55 2.3.4 EC Function 55 2.3.5 Optimal Switching Operation Strategy 56 2.4 Analysis and Discussion 57 2.4.1 Case 1: Euser ≥ KQuser 57 2.4.2 Case 2: Euser KQuser 59 2.4.3 Border Surfaces and Partition of Operating Modes 59 2.5 Case Study 60 2.5.1 Hypothetical Building Configuration 60 2.5.2 Test Results 61 2.6 Summary 67 References 67 3 A Balance-Space-Based Operation Strategy for CCHP Systems 69 3.1 Introduction and Related Work 69 3.2 Optimal Operation Strategy 70 3.2.1 CCHP Systems with Unlimited PGU Capacity 70 3.2.2 CCHP Systems with Limited PGU Capacity 74 3.3 EC Function Construction 78 3.3.1 PES 79 3.3.2 HTCS 79 Contents xi 3.3.3 CDER 79 3.3.4 EC Function 79 3.3.5 Optimal PGU Capacity 80 3.4 Case Study 80 3.4.1 Hypothetical Building Configuration 80 3.4.2 Simulation Parameters 80 3.4.3 Test Results 81 3.5 Summary 85 References 85 4 Energy Hub Modeling and Optimization-Based Operation Strategy for CCHP Systems 87 4.1 Introduction and Related Work 87 4.2 System Matrix Modeling 88 4.2.1 Efficiency Matrices of System Components 88 4.2.2 Dispatch Matrices 89 4.2.3 Conversion Matrix of the CCHP System 91 4.3 Optimal Control Design 92 4.3.1 Decision Variables 92 4.3.2 Objective Function 93 4.3.3 Non-linear Equality Constraint 93 4.3.4 Non-linear Inequality Constraints 95 4.3.5 Optimization Algorithm 97 4.4 Case Study 97 4.4.1 Hypothetical Building Configuration 97 4.4.2 Simulation Parameters 98 4.4.3 Test Results 99 4.5 Summary 102 4.A Non-convex Optimization Algorithm 103 4.A.1 EC Function Construction 103 4.A.1.1 PES 103 4.A.1.2 HTCS 103 4.A.1.3 CDER 104 4.A.1.4 EC Function 104 4.A.2 Optimization Problem Formulation 104 4.A.2.1 Objective Function 104 4.A.2.2 Non-convex and Non-linear Equality Constraints 105 4.A.2.3 Linear Inequality Constraints 105 4.A.2.4 Non-convex and Non-linear Inequality Constraints 106 4.A.3 Optimization Algorithm 106 4.A.3.1 An Exact Penalty Formulation 106 4.A.3.2 Convexification of the Non-convex Inequality Constraints 108 4.A.3.3 Summary 111 References 112 xii Contents 5 Short-Term Load Forecasting and Post-Strategy Design for CCHP Systems 113 5.1 Introduction and Related Work 113 5.2 Estimation Model and Load Forecasting 115 5.2.1 First Stage Identification – IV Estimation 115 5.2.2 Second Stage Identification – TSRLS 116 5.2.3 Load Forecasting 118 5.3 Operation Strategy Design 119 5.3.1 Optimal Operation Strategy for Forecasted Load 120 5.3.2 Post-strategy Design 120 5.4 Case Study 124 5.4.1 Hypothetical Building Configuration 124 5.4.2 Weather and Load Data 124 5.4.3 Test Results 130 5.5 Summary 134 5.A Closed-Form Identification Solution of Quadratic ARMAX Model 134 5.A.1 Quadratic ARMA Model 134 5.A.2 Quadratic ARMAX Model 137 References 138 6 Complementary Configuration and Operation of a CCHP-ORC System 140 6.1 Introduction and Related Work 140 6.2 System Configuration and Formulation 141 6.2.1 Energy Flows and Balances 142 6.2.2 Equipment Efficiency and Energy Conversion 143 6.2.3 Two Key Adjustable Parameters 145 6.2.4 Electricity to Thermal Energy Output Ratio 145 6.3 Optimal Operation Strategy for Normal Load Cases 146 6.3.1 Normal Load Case 1: Euser = KQeq 146 6.3.2 Normal Load Case 2: Euser KQeq 146 6.3.3 Normal Load Case 3: Euser KQeq 147 6.3.4 Decision-making Process 148 6.4 Operation Strategy for Overload Cases 148 6.4.1 Overload Case 1: Euser Ē pgu o and Qeq Q̄ r 149 6.4.2 Overload Case 2: Euser Ē pgu o and Qeq ≤ Q̄ r 150 6.4.3 Overload Case 3: Euser ≤ Ē pgu o and Qeq Q̄ r 151 6.5 EC Function of the CCHP-ORC System 152 6.6 Case Study 152 6.6.1 Hypothetical Building Configuration 152 6.6.2 Test Results 152 6.7 Summary 155 References