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Phd Thesis Optimising Thermal Energy Recovery, Utilisation And OPTIMISING THERMAL ENERGY RECOVERY, UTILISATION AND MANAGEMENT IN THE PROCESS INDUSTRIES MATHEW CHIDIEBERE ANEKE PhD 2012 OPTIMISING THERMAL ENERGY RECOVERY, UTILISATION AND MANAGEMENT IN THE PROCESS INDUSTRIES MATHEW CHIDIEBERE ANEKE A thesis submitted in partial fulfilment of the requirements of the University of Northumbria at Newcastle for the degree of Doctor of Philosophy Research undertaken in the School of Built and Natural Environment in collaboration with Brunel University, Newcastle University, United Biscuits, Flo-Mech Ltd, Beedes Ltd and Chemistry Innovation Network (KTN) August 2012 Abstract The persistent increase in the price of energy, the clamour to preserve our environment from the harmful effects of the anthropogenic release of greenhouse gases from the combustion of fossil fuels and the need to conserve these rapidly depleting fuels has resulted in the need for the deployment of industry best practices in energy conservation through energy efficiency improvement processes like the waste heat recovery technique. In 2006, it was estimated that approximately 20.66% of energy in the UK is consumed by industry as end-user, with the process industries (chemical industries, metal and steel industries, food and drink industries) consuming about 407 TWh, 2010 value stands at 320.28 TWh (approximately 18.35%). Due to the high number of food and drink industries in the UK, these are estimated to consume about 36% of this energy with a waste heat recovery potential of 2.8 TWh. This work presents the importance of waste heat recovery in the process industries in general, and in the UK food industry in particular, with emphasis on the fryer section of the crisps manufacturing process, which has been identified as one of the energy-intensive food industries with high waste heat recovery potential. The work proposes the use of a dual heat source ORC system for the recovery and conversion of the waste heat from the fryer section of a crisps manufacturing plant to electricity. The result, obtained through modelling and simulation, shows that the proposed technology can produce about 92% of the daily peak electricity need of the plant which is currently 216 kW. Also, the economic analysis shows that the proposed technology is viable (even at an inflation rate of 5.03% and discounted rate of 6%), with a payback period of approximately three years and net present value of over £2.2 million if the prices of electricity and carbon is at an average value of £0.16 and £13.77 respectively throughout the 30 years service life of the plant. The life cycle assessment study shows that the proposed technology can reduce the CO 2 emission by 139,580 kg/year if the electricity produced is used to displace ii that which would have been produced from a conventional coal-fired power plant. Keywords : Waste Heat Recovery, Energy Efficiency, Organic Rankine Cycle, Life Cycle Assessment, Carbon Emission Reduction, Entropy Generation. iii Table of Contents Abstract ............................................................................................................... ii Table of Contents ............................................................................................... iv List of Figures .................................................................................................... ix List of Tables.................................................................................................... xiv Glossary ............................................................................................................ xv Dedication ....................................................................................................... xviii Acknowledgements .......................................................................................... xix Author’s Declaration .......................................................................................... xx Chapter One ....................................................................................................... 1 1 Introduction .................................................................................................. 1 1.1 Energy and Industry ............................................................................... 1 1.2 Project Motivations ................................................................................ 8 1.3 Waste Heat Energy Recovery ................................................................ 8 1.3.1 Where Do We Recover Waste Heat Energy? ................................... 9 1.3.2 Why Do We Recover Waste Heat Energy? ..................................... 10 1.3.3 How Do We Recover Waste Heat Energy? ..................................... 16 1.4 Waste Heat Energy Utilization ............................................................. 20 1.5 Energy Management............................................................................ 24 1.6 Aim of the Project ................................................................................ 26 1.7 Project Objectives ................................................................................ 27 1.8 Structure of the Thesis ......................................................................... 28 Chapter Two ..................................................................................................... 31 2 Literature Review ....................................................................................... 31 2.1 State of the Art Waste Heat Recovery Techniques/Applications ......... 31 iv 2.1.1 Waste Heat for Power Generation .................................................. 31 2.1.2 Waste Heat for Wastewater Desalination ........................................ 47 2.1.3 Waste Heat for Cooling or Refrigeration Applications ..................... 62 2.2 Overall Conclusions from the Literature Review .................................. 78 2.2.1 Original Contribution to Knowledge ................................................. 78 Chapter Three ................................................................................................... 81 3 Modelling and Simulation Tool ................................................................... 81 3.1 Modelling and Simulation Software ...................................................... 81 3.1.1 IPSEpro Simulation Software .......................................................... 81 3.1.2 Modelling an Object Using IPSEpro MDK ....................................... 85 3.1.3 Modelling a Process Using IPSEpro PSE ....................................... 87 Chapter Four ..................................................................................................... 89 4 Potato Crisp/Chip Manufacturing Process ................................................. 89 4.1 Energy Consumption in Crisp Manufacturing Process ......................... 95 4.2 Waste Heat Recovery Potential in Crisp Manufacturing Process ........ 96 Chapter Five ..................................................................................................... 97 5 Thermodynamics of ORC System and IPSEpro MDK Modelling of ORC Unit Operations .......................................................................................... 97 5.1 Thermodynamic Properties .................................................................. 97 5.2 Thermodynamic Processes ................................................................. 98 5.3 Thermodynamic Laws .......................................................................... 99 5.3.1 First Law of Thermodynamics ......................................................... 99 5.3.2 Second Law of Thermodynamics .................................................. 100 5.4 Reversible Cycle ................................................................................ 101 5.5 Irreversible Cycle ............................................................................... 104 v 5.6 Thermodynamic Processes of ORC System ...................................... 104 5.7 Steady State Modelling of the Proposed ORC Unit Operations in IPSEpro MDK ....................................................................................... 107 5.7.1 Evaporator (LMTD Method) .......................................................... 108 5.7.2 Condenser (LMTD Method) .......................................................... 110 5.7.3 Turbine/Expander ......................................................................... 112 5.7.4 Pump ............................................................................................. 115 5.7.5 Motor ............................................................................................. 116 5.7.6 Working Fluid Enthalpy Parameter ............................................... 117 Chapter Six ..................................................................................................... 119 6 Proposed ORC System Utilizing Waste Heat from the Fryer for Power Generation ............................................................................................... 119 6.1 Process Description of the Proposed ORC System ........................... 120 6.2 Waste Heat Quality ............................................................................ 121 6.2.1 Waste Heat from Fryer Foul Gas .................................................. 121 6.2.2 Waste Heat from the Exhaust Stack ............................................. 121 6.3 Building the IPSEpro Model of an ORC System Using IPSEpro PSE 121 6.3.1 Proposed Water Cooled Dual Heat Source ORC System
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