Parametric Analysis of Carbon Dioxide Trancritical Power Cycle PDF

Parametric analysis and optimization of Carbon Dioxide Transcritical Power Cycle Name of Students Roll No 1. Muhammad Shoaib (G.L) 18ME67 2. Zeeshan Ali 18ME28...

Parametric analysis and optimization of Carbon Dioxide Transcritical Power Cycle Name of Students Roll No 1. Muhammad Shoaib (G.L) 18ME67 2. Zeeshan Ali 18ME28 3. Huzaifa Ahmed 18ME29 SUPERVISED BY Prof. Dr Abdul Fatah Abbasi DEPARTMENT OF MECHANICAL ENGINEERING MEHRAN UNIVERSITY OF ENGINEERING AND TECHNOLOGY, JAMSHORO, PAKISTAN Submitted in partial fulfilment of the requirement of the degree of Bachelor of Mechanical Engineering. October of 2022 i  DEDICATION This thesis study is dedicated to Almighty Allah, who is the most merciful and kind, we thank Almighty Allah for giving us guidance and strength for this study. Secondly, we would like to thank our beloved parents who have been our greatest source of inspiration and gave us strength when we thought of giving up, and provided us with their emotional, moral, spiritual and financial support. Last but not least, we are grateful for having kind and generous brothers, sisters, friends and classmates who supported us when we needed them. ii  CERTIFICATE This is to certify that the work presented in this thesis titled ‘‘Parametric analysis and optimization of Carbon Dioxide Transcritical Power Cycle’’ is written by the following students under the supervision of Prof. Dr. Abdul Fatah Abbasi. Name of Students Roll No 1. Muhammad Shoaib (G.L) 18ME67 2. Zeeshan Ali 18ME28 3. Huzaifa Ahmed 18ME29 Project Supervisor External Examiner Chairman Department of Mechanical Engineering Dated ……………………… iii  ACKNOWLEDGEMENT First of all, we would like to thank Almighty Allah who has blessed us with strength and kept us safe, we could not have completed this thesis without his blessings and help. After that, we would like to give our warmest thanks to our final year project supervisor Prof. Dr Abdul Fatah Abbasi whose encouragement and extensive knowledge made this thesis possible, we are grateful for his contribution in helping us complete this thesis project. I could not have dreamed of having a better supervisor for our thesis. Lastly, we would like to thank our friends and colleagues whose knowledge has helped us to somewhat improve this thesis. iv  ABSTRACT In this thesis, the potential utilization of low-grade waste heat by the carbon dioxide transcritical power cycle (CDTPC) is analyzed. The working fluid is chosen CO2 as it has better temperature glide match with heat source at supercritical state than most alternatives in vapor generator. The thermodynamic parameters were analyzed with respect to energy and exergy on basic CDTPC to determine power, work input, work output, thermal efficiency, exergy efficiency and exergy destruction at each component. The mathematical models of exergy and energy were developed on EES software and the results were calculated with fixed mass flow rate of exhaust gas, fixed condensation temperature of condenser, fixed heat sink temperature and fixed isentropic efficiencies of turbine and pump by varying high pressure in CDTPC system. To optimize the thermal efficiency of the chosen cycle, CDTPC with regenerator was also analyzed and compared with basic CDTPC to determine which one is more suitable at given operating conditions and the results obtained were in favor of CDTPC with regenerator. v  TABLE OF CONTENTS TITLE PAGE................................................................................................................ i DEDICATION.............................................................................................................. ii CERTIFICATE...........................................................................................................iii ACKNOWLEDGEMENT.......................................................................................... iv ABSTRACT.................................................................................................................. v TABLE OF CONTENTS........................................................................................... vi LIST OF FIGURES..................................................................................................viii LIST OF TABLES...................................................................................................... ix LIST OF SYMBOLS................................................................................................... x CHAPTER 01............................................................................................................... 1 INTRODUCTION........................................................................................................ 1 1.1 Overview:........................................................................................................ 1 1.2 Carbon dioxide transcritical power cycle:....................................................... 2 1.3 Advantages of CO2 :........................................................................................ 3 1.4 Problem statement:.......................................................................................... 3 1.5 Objectives:....................................................................................................... 4 1.6 Scope of the research:..................................................................................... 4 CHAPTER 02............................................................................................................... 5 LITERATURE REVIEW........................................................................................... 5 CHAPTER 03............................................................................................................. 10 METHODOLOGY.................................................................................................... 10 3.1 System description........................................................................................ 10 3.1.1 Basic CDTPC......................................................................................... 10 3.1.2 CDTPC with regenerator....................................................................... 11 3.2 Thermodynamic analysis of Carbon dioxide transcritical power cycle:....... 12 3.3 Mathematical model...................................................................................... 12 vi  3.3.1 Energy analysis of the CDTPC:............................................................. 12 3.3.2 Exergy analysis of CDTPC:................................................................... 16 3.4 Validation of model;...................................................................................... 21 3.5 Parametric analysis:....................................................................................... 22 3.6 Working fluid analysis:................................................................................. 23 CHAPTER 4............................................................................................................... 24 RESULTS AND DISCUSSIONS.............................................................................. 24 4.1 Impact of turbine inlet pressure (10Mpa to 30Mpa) for different maximum temperatures vs thermal efficiency on CDTPC system:.......................................... 24 4.2 Impact of turbine inlet pressure(10Mpa to 30Mpa) for different temperatures vs Power on CDTPC system:................................................................................... 25 4.3 Impact of turbine inlet pressure(10Mpa to 30Mpa) on fixed maximum temperature(Tmax=150) vs work on CDTPC system:;........................................... 26 4.4 Impact of exhaust gas inlet temperature (130°C to 170°C) on exergy destruction in each component:............................................................................... 27 4.5 Impact of exhaust gas inlet temperature (130°C to 170°C) on exergy efficiency:................................................................................................................ 28 4.6 Efficiency of CDTPC cycle with and without regenerator:.......................... 29 CHAPTER 05............................................................................................................. 30 CONCLUSION AND FUTURE WORK................................................................. 30 5.1 Conclusions................................................................................................... 30 5.2 Recommendations:........................................................................................ 31 5.3 Future work:.................................................................................................. 31 References:.................................................................................................................. 32 vii  LIST OF FIGURES Figure 1: Schematic diagram of basic CDTPC ………………………………… 10 Figure 2: Schematic diagram of CDTPC with regenerator …………………….. 11 Figure 3: Turbine inlet pressure vs cycle efficiency …………………………… 24 Figure 4: Turbine inlet pressure vs net-work …………………………………... 25 Figure 5: Turbine inlet pressure vs work output, work input and net-work …… 26 Figure 6: Exhaust gas inlet temperature vs Exergy destruction …………………27 Figure 7: Exhaust gas inlet temperature vs Exergy efficiency …………………. 28 Figure 8: Cycle efficiency vs CDTPC with and without regenerator...………… 29 viii  LIST OF TABLES Table 1: Validation of model with literature review parameters …………………. 21 Table 2: Constant Parametric values and their range in CDTPC ………………… 22 Table 3: Properties of carbon dioxide CO2 ……………………………………….. 23 ix  LIST OF SYMBOLS CDTPC Carbon dioxide transcritical power cycle CO2 Carbon dioxide Cp Isobaric specific heat [kJ/kg] EES Engineering equation solver GWP Global warming potential IHX Internal heat exchanger M molecular mass [g/mol] ODP Ozone depletion region ORC Organic rankine Cycle P Pressure [kpa] T Temperature [◦C] TPC Transcritical power cycle Tgin Temperature of exhaust gas at inlet of vapor generator Tgo Temperature of exhaust gas at outlet of vapor generator Ẇ Work [kW] exg Exergy h Enthalpy max Maximum mcl Mass flow rate of cooling liquid mco2 Mass flow rate of carbon dioxide α Fraction of maximum theoretical work ᶯ Efficiency Q̇ Rate if heat transfer 1,2,3… respective state points in the system x  CHAPTER 01 INTRODUCTION 1.1 Overview: In this age, Reducing the amount of fossil fuels used in industries is major concern of the whole world to reduce the toxic gases produced while burning fossil fuels. However, due to increasing demand for electricity, many nations are planning to build coal-fired power plants which would release a large amount of heat and carbon dioxide in the Environment. Apart from coal-fired powerplants, A large amount of exhaust gases are released into Environment from diesel engines, and nuclear power plants, etc. This pollutes the environment and disturbs the Echo system of all living beings therefore Waste heat recovery (WHR) systems are built to recover some of that energy and convert it into useful work through turbine by combining evaporator with exhaust flue gases which have low-grade energy. There are several Waste Heat Recover systems such as ORC, CDTPC, etc, therefore choosing any WHR under various operating conditions should be done carefully however choosing carbon dioxide power cycle has many advantages, as refrigerant CO2 has many benefits Such as CO2 is natural, cheap, abundant in the environment and is non-toxic. Other than recovering waste heat from engines, CDTPC can also utilize green energy such as concentrated sunlight or geothermal energy to produce useful work. There has been some work done in CDTPC and still there is more to work on it, as it will help to decide when to choose CDTPC over other WHR systems therefore in the department of WHR, CDTPC has gained interest and attention from both industry and academia. The purpose of this thesis is to analyze CDTPC to improve its efficiency under given working parameters to utilize waste heat energy. 1 1.2 Carbon dioxide transcritical power cycle: A Transcritical power cycle (TPC) is a closed cycle in which working fluid exists in both supercritical and subcritical states during complete cycle, usually working fluid is supercritical at turbine inlet and subcritical on other stages namely condenser outlet and pump outlet in a simple transcritical power cycle. The purpose of transcritical power cycle (TPC) is to utilize the energy from waste heat exhaust gaseous, in case of carbon dioxide transcritical power cycle it can convert low- grade waste heat (