Design and Implementation of PLC based Water Level Control System

Project Title

Design and Implementation of PLC based Water Level Control System

Project Area of Specialization Internet of ThingsProject Summary

The changes in industrial automation have been happening very fast since the advent of first ever Programmable Logic Controller in 1960. In this project, a basic smart relay based Programmable Logic Controller is used to control water level in a container which indirectly can control different industrial parameters. Water level controller seems a problem encountered so many times in literature but it have not yet gain any significant improvement. An Arduino based water level controller is designed to mark some development in the problem considered.

Water level control system is a typical process control problem. It is highly important in industrial applications such as boilers in nuclear power plants to regulate steam supply. It is reported that about 25% of emergency shutdowns in the nuclear power plants are caused by poor control of the steam generator water level. Water level control system is a very complex system because of the nonlinearities and uncertainties of the system. Therefore, design of an accurate and effective water level controller is needed. In this project, different mechanical parts are designed using Solidworks. Finite Element Analysis (FEA) and Flow simulations are performed on the water tank to ensure safe design. The dynamic process is modelled on MATLAB (Simulink). The output response for PID controller and fuzzy controller is simulated. A Fatek PLC is selected as a controller of the project. A comparison is made between the PID controller and fuzzy controller at the end of this report. Finally, all the steps taken to make the experimental setup are demonstrated.

Project Objectives

The main objective of this project is to design and develop an automatic water level controller to maintain the outlet process of the water level at its desired level. The project also focuses on the need of the people to install automatic water level controller to avoid wastage of water. Water level control seems a bit simple at first glance but fast and accurate control of water can be used in many other Engneering Applications. Perfect water level control can reduce 25% emergency shutdowns.

Project Implementation Method

The project is implemented step by step as shown in figure for implemetation plan. 

Task/Month 2018-19	Sep	Oct	Nov	Dec	Jan	Feb	Mar	Apr	May
Basic Research, Literature Review, Proposal Report, Proposal Presentation
Design of water tank Finite Element Analysis, Flow Simulations
Mechanical Design of the experimental setup
Detail Design Report, Detail Design Presentation
Work on Hardware
Finalizing Hardware

Task/Month 2018-19

Basic Research, Literature Review, Proposal Report, Proposal Presentation

Design of water tank

Finite Element Analysis, Flow Simulations

Mechanical Design of the experimental setup

Detail Design Report, Detail Design Presentation

Work on Hardware

Finalizing Hardware

Benefits of the Project

1. Living in an age where we need to be more conscious of the energy that we use, a water level controller is ideal at saving power. Normally, regulating water levels can consume electricity and wast water. However, with automatic controllers, the electricity usage is limited as well as less water needed to regulate a supply.
2. A water level controller helps save money by limiting the waste of water and electricity. These devices accurately regulate how much energy is used to protect against any unnecessary water/electricity usage. Over time, the money saved is quite substantial.
3. Another notable advantage with these devices is that they regulate on their own. Eliminating manual operations with a timer switch, the frustrations of manual monitoring water tanks is minimized. Water levels are maintained at the appropriate levels thanks to the automatic operations of these devices.
4. On average, water pumps are used more during mid day. A water level controller can maximize the water usage provided during mid day while automatically lessening the water usage at night.  This results to an appropriate level of water at all times being maintained, while providing you with the maximum use of your water at the appropriate times.
5. Addressing the durability problems found in earlier designs, the solid state electronics in the newer models help to eliminate them. Not only do they help to eliminate the durability issues, but they also create considerable savings of the life span of the unit with an advanced modular design. In order to minimize problem areas of these designs, the only moving parts are the relays. These relays are easily replaced and tested by any skilled operator or electrician, while being an inexpensive part.
6. These new solid state electronics, and integrated electronics, offer superior performance, hassle-free installation, and lower cost to operate over time when compared to the lifespan of the original design. For continuous monitoring, the integrated firmware and digital dry-contact circuitry easily and quickly connect to the automation systems of a building. Each function of the integrated electronics and relays use LED lights to offer operators the ability to visually scan them in order to verify proper operations.

7. The following table lists some of the important applications of the water level control system.

   Water tank level control	Fuel tank level gauging
   Oil tank level control	High & low level alarms
   Pool water level control	Leachate level control
   Cooling tower water level control	Sewage pump level control
   Remote monitoring liquid	Pump controller
   Stream level monitoring	Process batch control & monitoring
   Tsunami warning and sea level monitoring	Irrigation control
   Dredging spoils level	Boiler Blowdown Tank

Water tank level control

Oil tank level control

Pool water level control

Cooling tower water level control

Remote monitoring liquid

Stream level monitoring

Tsunami warning and sea level monitoring

Dredging spoils level

Technical Details of Final Deliverable

The experimental setup designed works on 240V AC  supply. Two different types of transformers are used to feed different output currents to different devices as they require. Since most of the devices work on DC (Direct Current) so traditional power converting circuit known as bridge rectifier is used to convert Alternating current to Direct Current. Since smart relay based PLC is very sensitive to fluctuating currents so a DC to DC buck converter is used to make sure that constant 12V  voltage is applied to the PLC. An Arduino is used to read sensor values and to send signals to PLC. The PLC decides on what to do next .i.e. when to ON and OFF the mini water pumps that are used as an actuating valves. An LCD is used to display sensor values. To make sure less connecting wires between LCD and Arduino are used, an I2C module is used. A CO2  Gas Sensor is used to measure carbon dioxide level around the water tank. According to researchers, the CO2  gas level on the top layer of water in the ocean has been increasing day by day. A day will come when the ocean water will get saturated due to CO2  gas and the lives of species living under the ocean water would get affected. The CO2  gas Sensor senses the carbon dioxide level in the environment around water tank and it turns ON water pump when its value gets greater than 40.

Final Deliverable of the Project Hardware SystemType of Industry IT , Petroleum , Agriculture , Energy , Manufacturing , Others , Security Technologies Internet of Things (IoT), OthersSustainable Development Goals No Poverty, Zero Hunger, Good Health and Well-Being for People, Clean Water and Sanitation, Affordable and Clean Energy, Decent Work and Economic Growth, Industry, Innovation and Infrastructure, Responsible Consumption and Production, Climate Action, Life Below Water, Life on LandRequired Resources

Water tank level control	Fuel tank level gauging
Oil tank level control	High & low level alarms
Pool water level control	Leachate level control
Cooling tower water level control	Sewage pump level control
Remote monitoring liquid	Pump controller
Stream level monitoring	Process batch control & monitoring
Tsunami warning and sea level monitoring	Irrigation control
Dredging spoils level	Boiler Blowdown Tank