View metadata, citation and similar papers at core.ac.uk brought to you by CORE provided by UTHM Institutional Repository i INVESTIGATING FLUSH SYSTEM METHOD FOR MINIMUM WATER USAGE OF TOILET SYSTEM MOHD SYAFIQ SALMAN BIN OTHMAN A project report submitted in partial fulfillment of the requirement for the award of the Degree of Master of Mechanical Faculty of Mechanical And Manufacturing Engineering Universiti Tun Hussein Onn Malaysia JANUARY 2014 v ABSTRACT A major concern for most people these days is the use and availability of clean water. With 83 million more people on Earth each year, demands for clean water will keep on rising. Water is everywhere and also important to living things on Earth. But because of the global warming and pollution, water has become deficit in many parts of the world. It can be foreseen that one day water will become a very valuable asset for countries in the future as energy is now. In this study, focus will be given more on the effect of water tank designs in reducing the volume of water usage in toilet system. Testing was divided into two sections that were experimental study and simulation study. First, experimental study conducted to test the performance of four different types of tanks and results are recorded. After that, simulation study conducted and data was recorded. The parameters of the study were the effect of depth of water and design of the water tanks towards pressure and volume flow rate of the water. Based from the test results, comparison was calculated. With percentage error below than 5 percent, it has been determined that simulation study was indeed suitable for this study. To achieve the objectives of this study, the change in design of water tank was proposed to minimize the amount of water used without sacrificing the performance of the toilet. By modifying the water tank designs, the amount of water used inside the tank can be decreased. From simulation study that has been conducted for two design concepts, pressure exerted from the tanks only lost a little amount of energy. As conclusion, by changing the design of water tanks without changing the water level, one could help reduce the amount of water used for flushing his waste. At the same time, it will not affecting the performance of the whole toilet system. vi ABSTRAK Satu kebimbangan utama bagi kebanyakan penduduk dunia pada hari ini ialah penggunaan serta bekalan air bersih. Dengan lebih daripada 83 juta orang di lahirkan setiap tahun, permintaan untuk air bersih akan terus meningkat. Air boleh di dapati di mana-mana jua dan amat penting untuk kehidupan di Bumi. Tetapi disebabkan pemanasan global serta pencemaran, air telah menjadi berkurangan di kebanyakan tempat. Boleh diramalkan bahawa suatu hari nanti air akan menjadi aset yang amat berharga bagi sesebuah negara pada masa akan datang sebagaimana permintaan untuk tenaga pada masa sekarang. Dalam kajian ini, tumpuan akan lebih diberikan kepada kesan reka bentuk tangki air dalam mengurangkan jumlah penggunaan air bagi keseluruhan sistem tandas. Ujian akan dibahagikan kepada dua bahagian iaitu kajian eksperimen dan simulasi. Kajian eksperimen dijalankan untuk menguji prestasi empat jenis tangki dan keputusan direkodkan. Kemudian, kajian simulasi dijalankan dan data direkodkan. Parameter kajian ini ialah kesan kedalaman air serta reka bentuk tangki air terhadap tekanan dan kadar aliran isipadu air. Berdasarkan dari keputusan ujian, perbandingan telah dikira. Dengan ralat peratusan bawah daripada 5 peratus , ia membuktikan bahawa kajian simulasi sememangnya sesuai untuk kajian ini. Bagi mencapai objektif kajian, perubahan dalam reka bentuk tangki air telah dicadangkan untuk mengurangkan jumlah air yang digunakan tanpa mengorbankan prestasi tandas. Dengan mengubah reka bentuk tangki air, jumlah air yang digunakan di dalam tangki dapat dikurangkan. Dari kajian simulasi yang telah dijalankan terhadap dua konsep reka bentuk, didapati hanya sedikit kehilangan tekanan sahaja yang dikesan. Kesimpulannya, dengan menukar reka bentuk tangki air tanpa mengubah paras air, ia dapat membantu mengurangkan jumlah air yang digunakan untuk mengepam keluar bahan buangan. Pada masa yang sama, ia tidak akan memberi kesan kepada prestasi keseluruhan sistem tandas. vii CONTENTS TITLE i DECLARATION ii DEDICATION iii ACKNOWLEDGEMENT iv ABSTRACT v ABSTRAK vi CONTENTS vii LIST OF FIGURES xii LIST OF TABLES xvi LIST OF SYMBOLS AND ABBREVIATIONS xviii LIST OF APPENDICES xx CHAPTER 1: INTRODUCTION 1 1.1 Water Crisis 1 1.2 High Efficiency Toilets 2 1.3 Dual Flush Toilets vs. Ultra-Low Flow Toilets 4 viii 1.4 Research Background 5 1.5 Theoretical Background 7 1.6 Problem Statement 9 1.7 Objectives 10 1.8 Scope of Research Work 10 1.9 Hypotheses 11 1.10 Dissertation Content 12 CHAPTER 2: STATE OF ART 14 2.1 Introduction 14 2.2 Pressure 15 2.3 Relationship between Pressure and Elevation 15 2.4 The Hydrostatic Paradox 16 2.5 Rate of Discharge 17 2.6 Toilet Design 18 2.7 Mechanism of Toilet Flush 19 2.7.1. Flush Mechanism 20 2.7.2. Refill Mechanism 21 2.8 Flush Tank Design 21 2.9 Conclusion 23 CHAPTER 3: METHODOLOGY 24 3.1 Overview 24 3.2 Objectives and Variables 24 ix 3.3 Mechanism of Toilet Works 25 3.4 Experimental Study 25 3.5 Sample Modeling 27 3.6 Simulation Study 27 3.7 Summary 28 CHAPTER 4: EXPERIMENTAL TEST 33 4.1. Introduction 33 4.2. Experiment 1: Performance on different design of tanks 34 4.2.1. Performance Test Setup 34 4.2.2. Work Flow Chart 36 4.2.3. Work Procedures 38 4.3. Experiment 1: Results and discussion 39 4.3.1. Pressure 39 4.3.2. Time taken 40 4.4. Experiment 2: Effect of volume of water 42 4.4.1. Performance test setup 42 4.4.2. Work Flow Chart 44 4.4.3. Work Procedures 46 4.5. Experiment 2: Results and Analysis 46 4.5.1. Pressure 46 4.5.2. Time Taken 49 4.5.3. Volume Flow Rate 51 x CHAPTER 5: SIMULATION STUDY 54 5.1. Introduction 54 5.2. Process Flow for Simulation Study 55 5.3. Creating a Flow Simulation Project 57 5.4. Viewing the Results 68 5.4.1. Viewing Surface Parameters 69 5.4.2. Viewing Flow Trajectories 71 5.4.3. Viewing Cut Plots 72 5.5. Results for Simulation Study 74 5.5.1. Results Simulation for tank model 3005 74 5.5.2. Results Simulation for tank model 3011 76 5.5.3. Results Simulation for tank model 3306 79 CHAPTER 6: RESULTS AND DISCUSSION 82 6.1. Introduction 82 6.2. Verification of Simulation Result 83 6.3. Discussion on Simulation Results 84 6.4. Design Optimization Proposed 84 6.4.1. First Concept 85 6.4.2. Second Concept 90 6.5. Conclusion 94 CHAPTER 7: NOVELTY OF RESEARCH FINDINGS 96 7.1. Introduction 96 7.2. Contribution from Experimental Study 96 xi 7.3. Contribution from Simulation Study 98 7.4. Contribution of findings 98 CHAPTER 8: CONCLUSION & FUTURE DEVELOPMENT 99 8.1. Introduction 99 8.2. Final conclusions about the results 99 8.3. Further simulations and improvements in the model 100 8.3.1. Study of the Whole Set of Toilet 100 8.3.2. Study On Other Design Proposed Based From This Study 100 8.4. Recommendation For Future Work 104 REFERENCES 105 APPENDICES 108 xii LIST OF FIGURES 1. 1 In-house water consumption in a typical Australia 3 1. 2 Niagara Stealth Toilet 4 1. 3 Water Efficiency Label 8 1. 4 The pressure fluid at rest increases with depth 11 2. 1 Pressure increase with depth 16 2. 2 The Hydrostatic Paradox 17 2. 3 Reduction in maximum WC flush volume since 1900 in Australia 19 2. 4 The Bowl Siphon 20 2. 5 The Flush Mechanism 21 3. 1 Process Flow Chart for Methodology 26 3. 2 Water tank design for LC 3029 D 29 3. 3 Water tank design for LC3005D 30 3. 4 Water tank design for LC 3011 BIBO 31 3. 5 Water tank design for LC 3306 D 32 xiii 4. 1 Four different water tanks model 34 4. 2 Experimental test setup 35 4. 3 Weight scale 35 4. 4 Experimental Test Work Flow 37 4. 5 Electronic manometer 38 4. 6 Setup for Electronic Manometer to drain pipe 39 4. 7 Schematic diagram for Experimental Study 39 4. 8 Full flush mode pressure for four different types of water tanks 41 4. 9 Half-flush mode pressure for four different types of water tanks 41 4. 10 Test setup for Experiment 2 42 4. 11 Water labeled inside water tanks 43 4. 12 Work flow chart for Experiment 2 45 4. 13 Effect of Depth of Water towards Pressure for 3029 water tank 47 4. 14 Effect of Depth towards Pressure for 3005 water tank model 48 4. 15 Effect of Water Volume towards Time (model: 3029) 49 4. 16 Effect of Water Volume towards Time (model: 3005) 50 4. 17 Volume Flow Rate for water tank model 3029 52 4. 18 Volume Flow Rate for water tank model 3005 53 5. 1 Work flow for simulation study 56 5. 2 Main menu in Flow Simulation Project 57 5. 3 Wizard – Project Configuration 57 5. 4 Flow Simulation Unit 58 xiv 5. 5 Analysis Type 59 5. 6 Default fluid for analysis study 59 5. 7 Wall condition 60 5. 8 Comparison of velocity for full flush and half flush mode 61 5. 9 Initial conditions 61 5. 10 Results and Geometry resolution 62 5. 11 The Flow Simulation Analysis Tree 62 5. 12 Specify the Boundary Conditions 63 5.