PLC BASED COAL LEVEL SENSING IN THERMAL POWER PLANTS PDF

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International Journal of Research and Engineering Volume 3, Issue 3 PLC BASED COAL LEVEL SENSING IN THERMAL POWER PLANTS Author(s): Rupesh Bhosale, Omkar Nalawade, Akshay Chavan Affiliation: K J College Of Engineering & Management Research, Pune Abstract: This paper refers to the plc based autom...

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International Journal of Research and Engineering

Volume 3, Issue 3

PLC BASED COAL LEVEL SENSING IN THERMAL POWER PLANTS Author(s): Rupesh Bhosale, Omkar Nalawade, Akshay Chavan Affiliation: K J College Of Engineering & Management Research, Pune Abstract: This paper refers to the plc based automation that can be carried out in the coal mining area and thermal power plant where coal handling is of prime importance. A coal-fired power plant typically has silos, bunkers or stockpiles in which the fuel is placed for storage purposes. Real-time feedback sensors are utilized to sense the coal height so data can be sent to downstream systems for further processing. there should be proper monitoring and observation over the level of the coal in the storage tanks which involves keeping continuous watch over the tanks in hazardous conditions. The performance of ultrasonic, radar, and laser rangefinder sensors was investigated to determine the height of coal stockpiles in various sites in a coal-fired power plant. hence this paper will bring you a brief idea about the various sensor that can be used to detect the level of the coal in the tanks with the sole controlling and monitoring action performed by programmable logic controller. Keywords: programmable logic controller, realtime, silos, feedback sensor.

(Fig no.1: coal level sensing) 1. Introduction Technological advances in recent years have resulted in development of programmable logic controller and a consequential revolution of control engineering. A programmable logic controller(PLC)is a special form of microprocessor based controller that uses a programmable memory to store the instruction and to implement the function such as logic, sequencing, timing, counting and arithmetic operation in order to control the machine and process. The first PLC was developed in 1969,they are now widely used in almost every industry where automation is carried out.

2. PLC system

(Fig no.2: PLC architecture) a)The processor or central processing unit is the main functional area of the plc that carries out all the logical and arithmetic operation. it monitors the status of the input devices and keeps the sequence in order according to the program stored in the memory. b) power supply unit is provided to power up the device.it convers the mains high AC voltage to low voltage signal usable by the plc processor c) programming device is used to enter the required program into the memory of the processor. the program is developed into the programming device and then it is downloaded into the plc. d)Input / Output module of the plc provides the interface between the system and the outside world. the input module gives the information and the status of the input devices such as feedback sensors, thermal sensors, limit switches connected at the input module. similarly output module provide access to the various output controlled devices such as actuators, relays, motors starters, solid state devices, etc. both the module provides electronic isolation to the processor. 3. Various input Feedback sensor a) LDR sensor : In our project we have used LDR sensor to detect the coal level in the storage tanks. A light dependent resistor(LDR) is a device whose resistivity is a function of the incident electromagnetic radiation hence an light sensitive device. When light falls on the LDR then its resistance decreases which results in the increase in the voltage at pin 2 of the IC555.IC555 has built in comparator that compares the input voltage at pin 2 and 1/3rd of the power supply voltage. when input falls below the 1/3rd of the power supply then output is high otherwise it is set low. so in brightness input voltage rises so we obtain no positive voltage at the output of pin3 to drive the relay or LED. besides in poor light condition we get output to energize.

\ Fig no.1: PLC

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ISSN 2348-7852 (Print) | ISSN 2348-7860 (Online) (This work is licensed under a Creative Commons Attribution 4.0 International License.)

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International Journal of Research and Engineering

(Fig no 2: LDR sensor circuit) b)Ultrasonic Sensor: Ultrasonic sensors transmit ultrasonic waves from its sensor head and again receives the ultrasonic waves reflected from an object. By measuring the length of time from the transmission to reception of the sonic wave, it detects the position of the object. Transducer This is a device which uses electrical energy to generate ultrasound waves, and which also converts ultrasound vibrational energy into electrical signals. A barium titanate transducer applying piezoelectric effect is normally used in ultrasound switches.

Volume 3, Issue 3 between the probe's sensing area and a grounded back target. If the gap between the sensor and the back target is stable, changes in the sensor output are indicitive of changes in thickness, density, or composition of the material in the gap .

Fig no.6: capacitive sensor

(fig no 4: ultrasonic sensor) Reflection and transmission Ultrasound waves move straight forward in a uniform medium, and are reflected and transmitted at the boundary between differing media. This phenomenon is affected by the type and shape of the media. 4.Result: c) Photoelectric sensor: It is an equipment used to discover the distance, absence, or presence of an object by using a light transmitter, often infrared, and a photoelectric receiver. A self-contained photoelectric sensor contains the optics, along with the electronics. It requires only a power source. The sensor performs its own modulation, demodulation, amplification, and output switching. A through beam arrangement consists of a receiver located within the line-of-sight of the transmitter. In this mode, an object is detected when the light beam is blocked from getting to the receiver from the transmitter.

( Fig no5: Photoelectric sensor)

d) Capacitive Sensor: A capacitive sensor is a proximity sensor that detects nearby objects by their effect on the electrical field created by the sensor. Capacitive sensors are sensitive to nonconductive materials which are placed

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This sensors detects the the object arriving under their fields without physical contact and generates the output signal which is provided at input module of PLC. 5.Conclusion: Thus various feedback sensors are available in the market and can be studied and examined for there operating limitations and can be made to use for detecting coal level. Though this technology is mentioned for coal level detection but further design and improvement can be undertaken to use for different industrial applications. . 6. Acknowledgements It gives us immense pleasure to present paper on “plc based coal level sensing in Thermal power plants”. We are profoundly grateful to our guide prof.Puja Choudhari for her scholastic approach and continuous encouragement with timely guidance, interest and curiosity through out the tenure of the project. We are highly obliged to our h.o.d prof. Dr.N. M. Lokhande, electrical engineering department for providing all facilities for this project. Finally we would like to thank all staff members of electrical department and those who have helped me in preparing this project paper directly or indirectly. Immense thanks to all our friends for giving us the timely support and co-operation with no time constraints. And last but not the least we are grateful to all non-teaching staff members of department who have knowingly or unknowingly helped in completing this project.

ISSN 2348-7852 (Print) | ISSN 2348-7860 (Online) (This work is licensed under a Creative Commons Attribution 4.0 International License.)

http://www.ijre.org

International Journal of Research and Engineering

Volume 3, Issue 3

7. References [1] Siemens. „Basic Of PLCs‟ STEP 2000 series, Siemens Technical Education Program. [2] Vijaya Rahgavan, Chitra.S. (conveyor controller using programmable logic controller) International journal of advancement in research & technology, volume 3,issue 8,august 2014, ISSN 2278-7763. [3] Daniel Sinkonde Kayange, Noel Mbonde .( An Automatic Circuit Design for Metal Detector by Using Programmable Logic Controller Technique) International Journal of Engineering Science and Innovative Technology Volume 4, Issue 1, January 2015, ISSN: 2319-5967 [4] http://circuiteasy.com/automatic-street-light/ [5] Sensor based effective monitoring of coal handling system(CHS)Kuttalkani. M,Natarjan.R, Vijaykumar. J,Arunan.S, Sarojini.L. [6] Petruzela,F.D. Programmable logic controllers, McGraw Hill,2005 [7] L.A.Bryan and E.Bryan,” programmable logic controller: theory and implementation,”1997 [8] securing SCADA system by Ronald L.Krutz. [9] Gary Dunning,” Introduction to Programmable Logic Controller,”Thomson,2nd edition.

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ISSN 2348-7852 (Print) | ISSN 2348-7860 (Online) (This work is licensed under a Creative Commons Attribution 4.0 International License.)

http://www.ijre.org...