An Arduino based control system for a brackish water desalination plant.

89 Pages·2015·1.4 MB·English

by  Caraballo, Ginna

AN ARDUINO BASED CONTROL SYSTEM FOR A BRACKISH WATER
DESALINATION PLANT

Ginna Caraballo, M.S.E.E.

Thesis Prepared for the Degree of
MASTER OF SCIENCE

UNIVERSITY OF NORTH TEXAS
August, 2015

APPROVED:
Miguel Acevedo, Major Professor
Shengli Fu, Committee Member and Chair of
the Department of Electrical
Engineering
Yan Wan, Committee Member
Costas Tsatsoulis, Dean of the College of
Engineering
Mark Wardell, Dean of the Tolouse Graduate
School
Caraballo, Ginna. An Arduino based control system for a brackish water desalination
plant. Master of Science (Electrical Engineering), August 2015, 79 pp, 19 tables, 39
illustrations, bibliographies, 54 titles.
Water scarcity for agriculture is one of the most important challenges to improve food
security worldwide. In this thesis we study the potential to develop a low-cost controller for a
small scale brackish desalination plant that consists of proven water treatment technologies,
reverse osmosis, cation exchange, and nanofiltration to treat groundwater into two final products:
drinking water and irrigation water. The plant is powered by a combination of wind and solar
power systems.
The low-cost controller uses Arduino Mega, and Arduino DUE, which consist of
ATmega2560 and Atmel SAM3X8E ARM Cortex-M3 CPU microcontrollers. These are widely
used systems characterized for good performance and low cost. However, Arduino also requires
drivers and interfaces to allow the control and monitoring of sensors and actuators. The thesis
explains the process, as well as the hardware and software implemented.
Copyright 2015
by
Ginna Caraballo
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ACKNOWLEDGMENTS
I would like to express my most sincere gratitude to Almighty God for giving me the
strength and perseverance to do this work.
I also would like to express immense gratitude to my supervisor Dr. Miguel Acevedo. His
support made it possible to complete the thesis work. I would like to take this opportunity to thank
him for his constant support, thoughtful suggestions, patience and advice. As well as Ran Nahir
and Paul Hunninghaus my fellows in the GreenDesal team who constantly helped me and
encouraged me during this process.
I want to thank all my friends and fellow students who helped me with their suggestions
and ideas for my project during the time of despair.
I am grateful to my family for their encouragement and support. Without their inspiration
it would have been more difficult to achieve my professional goals.
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TABLE OF CONTENTS
ACKNOWLEDGMENTS ............................................................................................................. iii
LIST OF TABLES ........................................................................................................................ vii
LIST OF FIGURES ..................................................................................................................... viii
CHAPTER 1 ................................................................................................................................... 1
1.1 Problem Statement ........................................................................................................... 2
1.2 Research Questions .......................................................................................................... 2
1.3 Limitations ....................................................................................................................... 3
1.4 Overview of the Remainder of the Thesis ........................................................................ 4
CHAPTER 2 ................................................................................................................................... 5
2.1 Feed ....................................................................................................................................... 7
2.2 Cation Exchanger CEX ......................................................................................................... 9
2.2.1 Adsorption .................................................................................................................... 10
2.2.2 Regeneration ................................................................................................................. 12
2.2.3 Conditions ..................................................................................................................... 12
2.3 Nanofiltration ...................................................................................................................... 14
2.4 Reverse Osmosis ................................................................................................................. 14
CHAPTER 3 ................................................................................................................................. 17
3.1 Arduino................................................................................................................................ 17
3.1.1 Arduino Mega 2560 R3 ................................................................................................ 18
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3.1.2 Arduino DUE ................................................................................................................ 18
3.2 Arduino Shield .................................................................................................................... 20
3.3 System Components and its Drivers ................................................................................... 22
3.3.1 Solenoid Valve ............................................................................................................. 22
3.3.2 Pumps and Compressor ................................................................................................ 25
3.3.3 Flow Meters .................................................................................................................. 28
3.3.4 pH Meter ....................................................................................................................... 29
3.3.5 EC Meter....................................................................................................................... 30
3.3.6 Pressure Transmitter ................................................................................................... 311
3.3.7 Temperature Transmitter ............................................................................................ 333
3.3.8 Dosing Pumps ............................................................................................................. 344
3.3.9 Proportional Valves ...................................................................................................... 37
3.3.10 Level Switches .......................................................................................................... 388
3.4 Wiring Diagram................................................................................................................. 400
3.4.1 Electrical connection .................................................................................................. 400
3.4.2 I2C Wiring Diagram ................................................................................................... 444
3.5 I/O Mapping ...................................................................................................................... 477
CHAPTER 4 ............................................................................................................................... 543
4.1 Arduino IDE ...................................................................................................................... 543
4.2 Actuators ........................................................................................................................... 554
4.2.1 ON/OFF Actuators ..................................................................................................... 554
4.2.2 Proportional Control ................................................................................................... 565
4.3 Sensor ................................................................................................................................ 576
4.3.1 Flow Rate .................................................................................................................... 587
4.3.2 Pressure, pH and Conductivity ..................................................................................... 59
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4.3.3 Temperature ................................................................................................................ 633
4.3.4 Level Switch ............................................................................................................... 655
4.4 I2C Communications......................................................................................................... 656
4.5 CEX, RO, NF and Feed Routines ....................................................................................... 67
4.5.1 Slave 1 .......................................................................................................................... 67
4.5.2 Slave 2 ........................................................................................................................ 712
CHAPTER 5 ................................................................................................................................. 77
BIBLIOGRAPHY ......................................................................................................................... 79
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LIST OF TABLES
Table 2-1: Feed system signals ....................................................................................................... 7
Table 2-2: CEX system signals ..................................................................................................... 10
Table 3-1: Arduino Comparison Table ......................................................................................... 20
Table 3-2: Technical Detail Solenoid Valve ................................................................................. 22
Table 3-3: Description Table for the Circuit Components ........................................................... 24
Table 3-4: Description Table for Pumps ....................................................................................... 26
Table 3-5: Description Table for flow meter ................................................................................ 28
Table 3-6: Description Table for pH Meter ................................................................................ 300
Table 3-7: Description Table for EC Meter ................................................................................ 311
Table 3-8: Description Table for 200 PSI Pressure Transmitter .................................................. 32
Table 3-9: Description Table for 500 PSI Pressure Transmitter................................................... 33
Table 3-10: Description Table for DS18B20 Temperature Sensor .............................................. 34
Table 3-11: Description Table for Peristaltic Pump ..................................................................... 35
Table 3-12: Peristaltic pump's flow rates. ..................................................................................... 36
Table 3-13: Description Table proportional Valve ........................................................................37
Table 3-14: I2C pins in Arduino Boards....................................................................................... 44
Table 3-15: I/O Mapping Slave 1 ................................................................................................. 47
Table 3-16: I/O Mapping Slave 2 ................................................................................................. 49
Table 3-17: I/O Mapping Slave 3 ................................................................................................. 53
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LIST OF FIGURES
Figure 2-1: Four major parts of the process and its components .....................................................6
Figure 2-2: Flow Diagram – Pump P1 Operation ............................................................................8
Figure 2-3: Flow Diagram - Flow rate adjustment ..........................................................................8
Figure 2-4: Flow Diagram - Overflow Protection T1 ......................................................................9
Figure 2-5: Flow Diagram - TDS value adjustment in T4 ...............................................................9
Figure 2-6: Flow Diagram – Adsorption .......................................................................................11
Figure 2-7: Flow Diagram – Regeneration ....................................................................................13
Figure 2-8: Flow Diagram – Nanofiltration ...................................................................................15
Figure 2-9: Flow Diagram- Reverse Osmosis ...............................................................................16
Figure 3-1: Arduino Mega 2560 R3...............................................................................................18
Figure 3-2: Arduino DUE ..............................................................................................................19
Figure 3-3: Arduino DUE Shield (Slave 3) .................................................................................. 21
Figure 3-4: Arduino Mega 2560 Shield (Slave 2) .........................................................................21
Figure 3-5: Adafruit Solenoid Valve .............................................................................................24
Figure 3-6: Solenoids Driver .........................................................................................................25
Figure 3-7: Drivers for solenoid valves .........................................................................................26
Figure 3-8: 5V Relays wired to the pumps and compressor ..........................................................27
Figure 3-9: Wiring Diagram 5V Relay ..........................................................................................28
Figure 3-10: Flow Meter - Adafruit ...............................................................................................29
Figure 3-11: pH Meter Kit- DFROBOT ........................................................................................30
Figure 3-12: EC meter ...................................................................................................................31
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Figure 3-13: 200 PSI Pressure Transmitter ....................................................................................32
Figure 3-14: 500 PSI Pressure Transmitter ....................................................................................33
Figure 3-15: Temperature Transmitter...........................................................................................34
Figure 3-16: Peristaltic Pump ........................................................................................................35
Figure 3-17: L293D connected to the pumps ................................................................................36
Figure 3-18: AMEP-3516 actuator VFZ-4103AM valve ..............................................................37
Figure 3-19: L293D connected to the proportional valves ............................................................38
Figure 3-20: Level Switches ..........................................................................................................38
Figure 3-21: Driver and Electrical Diagram Level Switch ............................................................39
Figure 3-22: Circuits for the Level Switches .................................................................................39
Figure 3-23: 24Vdc Electrical Diagram .........................................................................................40
Figure 3-24: Wiring Diagram Proportional Valve .........................................................................41
Figure 3-25: Wiring Diagram Flow Meter, Pump and Level Switch ............................................41
Figure 3-26: 12 VDC Electrical Diagram ......................................................................................42
Figure 3-27: Wiring Diagram Solenoid Valves .............................................................................43
Figure 3-28: Wiring diagram EC, pH, Temperature and Pressure Transmitters ...........................43
Figure 3-29: SPI bus configuration for 3 salves and 1 master .......................................................45
Figure 3-30: I2C connection of the system ....................................................................................46
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