Propane Gas Detection System Using Microcontroller

Transcription

1 Propane Gas Detection System Using Microcontroller Anand Mohan Assistant Professor, Department of Electronics & Communication Engineering RVS College of Engineering and Technology Jamshedpur, India. Shalini Kumari Assistant Professor, Department of Electronics & Communication Engineering RVS College of Engineering and Technology Jamshedpur, India. Deepak Kumar Assistant Professor, Department of Electronics & Communication Engineering RVS College of Engineering and Technology Jamshedpur, India. Kundan Kumar Assistant Professor, Department of Electronics & Communication Engineering RVS College of Engineering and Technology Jamshedpur, India. Abstract: Use of this system is to monitoring propane gas and if there is any leakage alarm will blow. The gas sensor is used to detect the presence of a dangerous LPG leak in home,cars or in a service station, storage tank environment. This system can be easily attached with an alarm unit, to sound an alarm or give a visual indication of the LPG concentration. The MQ-6 sensor can also sense iso-butane, propane, LPG and cigarette smoke. If the MQ-6 sensor senses any type of gas leakage from storage,the output of this sensor goes low. The microcontroller monitored this low signal and identify the gas leakage. Now the microcontroller is turn on LED and Buzzer. After few milliseconds delay, it also turn on exhaust fan for throwing gas out. Keyword-Butane,LPG,MQ-sensor Propane I. INTRODUCTION The LPG or propane which is flammable mixture of hydrocarbon gases used as fuel in many applications like homes, hostels, industries, automobiles, vehicles because of its desirable properties which include high calorific value, which produce the less smoke, produces less soot, and does not cause much harm to the environment. Natural gas is another widely used fuel in homes. Both gases burns to produce clean energy, however there is a serious problem Available 66

2 about their leakage in the air. The gases being heavier than air do not disperse easily and may lead to suffocation when inhaled also when gas leakage into the air may lead to explosion. Due to the explosion of LPG gas the number of deaths has been increased in recent years. To avoid this problem there is a need for a system to detect and also prevent leakage of LPG. Gas leak detection is the process of identifying potentially hazardous gas leaks by means of various sensors. These sensors usually employ an audible alarm to alert people when a dangerous gas has been detected. Now day s accident occurs due to leakage of LPG gas, this gas is highly inflammable and spread in air very quickly. Which damage life as well as property. It is necessary to detect the LPG gas and prevent from accident happen due to leakage of LPG gas. Our project had been designed to detect the LPG gas by using microcontroller and by using exhaust fan to decrease the concentration of LPG gas from that area and also alert the user by alarm. LPG gas detection system have been designed earlier with different component which included basis electronics component such the use of MQ-6 sensor which sense the LPG gases. They are used in gas leakage detecting equipment in family and industry, are suitable for detecting of LPG, isobutane, propane, LNG, avoid the noise of alcohol and cooking fumes and cigarette smoke. When it senses LPG gas it turn on the buzzer and exhaust fan to throughout gas out. Some of the limitations incurred in these circuits were as The circuit use MQ-6 sensors which senses propane and butane only. It is less sensitivity to other material like cooking fumes, cigarettes, etc. Sensitive material of MQ-6 gas sensor is SnO2, which with lower conductivity in clean air. Need of LPG Gas Detector As the LPG gas is widely use in commercial and domestic always a big issue for safety, which is much needed. 2.1 LPG Gas II. THEORY The LPG is finding wide range in homes, industries and in automobiles as fuels. In the year 1910 LPG, first produced by Dr.Walter Snelling the U.S Bureau of mines investigated gasoline to see why it evaporated so fast and discovered that the evaporating gases were propane, butane and other light hydrocarbons. Both LPG and natural gas are environmental friendly they easily be detected these gases are normally stored in pressurized Steel cylinders in liquid form and vaporize at normal temperatures. With comparison of air LPG is heavier therefore it flows along the floor and also settles in low points which make it difficult to disperse. LPG is a mixture of commercial butane and commercial propane having both saturated and unsaturated hydrocarbons.lpg marketed in India shall be governed by Indian Standard Code IS-4576 and the test methods by IS Characteristics of this dangerous gas include (a) vapor pressure: The pressure inside a LPG storage vessel/ cylinder will be equal to the vapor pressure Available 67

3 corresponding to the temperature of LPG in the storage vessel. The vapor pressure is dependent on temperature as well as on the ratio of mixture of hydrocarbons; (b) Flammability: LPG has an explosive range of 1.8% to 9.5% volume of gas in air. This is considerably narrower than other common gaseous fuels; (c) Combustion: The combustion reaction of LPG increases the volume of products in addition to the generation of heat. LPG requires up to 50 times its own volume of air for complete combustion ;(d) Odor: LPG has only a very faint smell, and consequently, it is necessary to add some odorant so that any escaping gas can vapor phase, but can, however, suffocate when in large concentrations due to the fact that it displaces oxygen.;(e) Toxicity: LPG even though slightly toxic, is not poisonous in can pose a serious effect if they leak. Impacts: LPG may leak as a gas or a liquid. If the liquid leaks it will quickly evaporate and form a relatively large cloud of gas which will drop to the ground, as it is heavier than air. LPG Vapors can run for long distances along the ground and can collect in drains or basements Cylinders can explode if involved in a fire. The health impact this dangerous gas can cause cold burns to the skin and it can act as an asphyxiate at high concentrations. Leak cause a negative effect to the health such that the hydrocarbons and other chemicals of the LPG causes very long sleep. It also causes irritated respiratory tract, nose and eyes. Problem Statement Gas leakage leads to various accidents resulting into both financial loss as well as human injuries. In human daily life environment gives the most significant impact to their health issues. The risk of firing, explosion, suffocation all are based on their physical properties such flammability, toxicity etc. The number of deaths due to the explosion of gas cylinders has been increasing in recent years. The reason for such explosion is due to substandard cylinders, old valves, worn out regulators and lack of awareness using gas cylinders add to the risks. Inspections by oil companies found that many LPG consumers are unaware of safety checks of gas cylinders. Another reason is illegal filling of gas cylinder also causes accidents. There is a need for a system to detect and also prevent leakage of LPG. Figure 2.1 : Types of hazardous gas and their risks symbol Necessity for detection: The consumers have to upgrade their safety standards, act in accordance with statutory requirements on Environmental commitments and most importantly the basic function being prevented by accidents and protect life and property from disasters. Figure 2.2 : Typical threshold value of LPG Thus it takes nearly 60 min to detect when 1% of gas leak occurs. As a solution for the problem, a monitoring system of gas detector by wireless system needs to be developed in order to solve the problem. By monitoring system wirelessly, user can remotely view the condition of the home without them being there themselves. Available 68

4 Vol. 2, Issue 3,Sepg 2015, ISSN III. DESIGN AND IMPLEMENTATION 3.1 Block Diagram made by plastic and stainless steel net. The heater provides necessary work conditions for work of sensitive components. The enveloped MQ-6 have 6 pin, 4 of them are used to fetch signals, and other 2 are used for providing heating current. Features:- High sensitivity to LPG, natural gas, town gas Small sensitivity to alcohol, smoke Fast response, stable and long life Figure 3.1 : Block Diagram for Propane gas detector system using microcontroller Relay Driver Circuit 3.2 Circuit Diagram And Description LPG Gas Detector Figure 3.3 : Relay Driver Circuit Figure 3.2 : Circuit diagram for LPG Gas Detector MQ-6 Sensor The circuit of relay K1 whose one terminal is attached to the transistor and LED for indication of supply or switching of voltage to the relay. When an active high signal is received from the port of the microcontroller to the base of transistor, the transistor becomes active high and these drive the relay which switches ON/OFF the appliance attached to other relay output Power Supply Circuit MQ-6 sensor made of SnO2 and measuring electrode and heater are fixed into acrust Available 69

5 Vol. 2, Issue 3,Sepg 2015, ISSN metal oxide crystal such as SnO2 is heated at a certain high temperature in air, oxygen is adsorbed on the crystal surface with a negative charge. Then donor electrons in the crystal surface are transferred to the adsorbed oxygen, resulting in leaving positive charges in a space charge layer. Thus, surface potential is formed to serve as a potential barrier against electron flow. Figure 3.4 : Power Supply Circuit The circuit consists of a single step-down transformer which is used to step down the Ac 220V main supply to 12v. The transformer on the output side is connected to a pair of diodes D1, D2, D3 and D4 which are used as a full wave rectifier circuit to get 12v DC voltage. The diodes D1 and D2 are connected in same direction and diode D3 and D4 are connected in same direction but opposite to that of diodes D1 and D2. The output of these rectified signal is then connected in parallel to the capacitors C1 and C2 which act as filter for reducing the ac ripples and get a constant dc voltage supply. For regulated 5v DC supply the terminal from the capacitor C2 is connected first to the voltage regulator LM7805 and then again further passed to the parallel capacitor C1 and C2 then the regulated 5v supply is obtained. This 12V DC supply is used to drive the relay driver circuit according to the command from the microcontroller. And the 5V supply is used as VCC for microcontroller and for different sensor circuits Working Principle The sensing material in TGS gas sensors is metal oxide, most typically SnO2. When a Inside the sensor, electricc current flows through the conjunctionn parts (grain boundary) of SnO2 micro crystals. At grain boundaries, adsorbed oxygen forms a potential barrier which prevents carriers from moving freely. The electrical resistance of the sensor is attributed to this potential barrier. In the presence of a deoxidizing gas, the surface density of the negatively charged oxygen decreases, so the barrier height in the grain boundary is reduced. The reduced barrier height decreases sensor resistance. IV. HARDWARE AND SOFTWARE REQUIRED 4.1 Microcontroller The microcontroller incorporates all the features that are found in microprocessor. The microcontroller has built in ROM, RAM, Input Output ports, Serial Port, timers, interrupts and clock circuit. A microcontroller is an entire computer manufactured on a single chip. Microcontrollers are usually dedicated devices embedded within an application. For example, microcontrollers are used as engine controllers in automobiles and as exposure and focus controllers in cameras. In order to serve these applications, they have a high concentration of on-chip facilities such as serial ports, parallel input output ports, timers, counters, interrupt control,analog-to-digital converters, random access memory, read only memory, etc. The Available 70

6 I/O, memory, and on-chip peripherals of a microcontroller are selected depending on the specifics of the target application. Since microcontrollers are powerful digital processors, the degree of control and programmability they provide significantly enhances the effectiveness of the application. The 8051 is the first microcontroller of the MCS-51 family introduced by Intel Corporation at the end of the 1970s. The 8051 family with its many enhanced members enjoys the largest market share, estimated to be about 40%, among the various microcontroller architectures. The microcontroller has on chip peripheral devices. In this unit firstly we differentiate microcontroller from microprocessor then we will discuss about Hardware details of 8051 and then introduce the Assembly level language in brief. Microcontroller (MC) may be called computer on chip since it has basic features of microprocessor with internal ROM, RAM, Parallel and serial ports within single chip. Or we can say microprocessor with memory and ports is called as microcontroller. This is widely used in washing machines,vcd player, microwave oven, and robotics or in industries. Microcontroller can be classified on the basis of their bits processed like8bit MC, 16bit MC. 8 bit microcontroller, means it can read, write and process 8 bit data. Ex microcontroller. Basically 8 bit specifies the size of data bus. 8 bit microcontroller means 8 bit data can travel on the data bus or we can read, write process 8 bit data Microcontroller AT89S52 The AT89S52 is a low-power, highperformance CMOS 8-bit microcontroller with 8K bytes of in-system programmable Flash memory. The device is manufactured using Atmel s high-density nonvolatile memory technology and is compatible with the industry-standard 80C51 instruction set and pin out. The on-chip Flash allows the program memory to be reprogrammed insystem or by a conventional nonvolatile memory pro-grammar. By combining a versatile 8-bit CPU with in-system programmable Flash on a monolithic chip, the Atmel AT89S52 is a powerful microcontroller which provides a highlyflexible and cost-effective solution to many embedded control applications. The AT89S52 provides the following standard features: 8K bytes of Flash, 256 bytes of RAM, 32 I/O lines, Watchdog timer, two data pointers, three 16-bit timer/counters, a six-vector two-level interrupt architecture, a full duplex serial port, on-chip oscillator, and clock circuitry. In addition, the AT89S52 is designed with static logic for operation down to zero frequency and supports two software selectable power saving modes. The Idle Mode stops the CPU while allowing the RAM, timer/counters, serial port, and interrupt system to continue functioning. The Power-down mode saves the RAM con-tents but freezes the oscillator, disabling all other chip functions until the next interrupt or hardware reset. Features: Compatible with MCS -51 Products 8K Bytes of In-System Programmable (ISP) Flash Memory Endurance: 10,000 Write/Erase Cycles 4.0V to 5.5V Operating Range Fully Static Operation: 0 Hz to 33 MHz Three-level Program Memory Lock 256 x 8-bit Internal RAM 32 Programmable I/O Lines Three 16-bit Timer/Counters Eight Interrupt Sources Full Duplex UART Serial Channel Available 71

7 Vol. 2, Issue 3,Sepg 2015, ISSN Low-power Idle and Power-down Modes Interrupt Recovery from Power-down Mode Watchdog Timer Dual Data Pointer Power-off Flag Fast Programming Time Flexible ISP Programming (Byte and Page Mode) Green (Pb/Halide-free) Packaging Option Block Diagram Of AT89S52 Figure 4.1: Block Diagram of AT89S PIN Configuration 4.2 Sensor A sensor is a transducer whose purpose is to senses some characteristic of its environments. It detects events or changes in quantities and provides a corresponding output, generally as an electrical or optical signal; for example, a thermo couple converts temperature to an output voltage. But a mercury-in-glass thermometer is also a sensor; it converts the measured temperature into expansion and contraction of a liquid which can be read on a calibrated glass tube. Sensors are used in everyday objects such as touch-sensitive elevator buttons and lamps which dim or brighten by touching the base, besides innumerable applications of which most people are never aware MQ-6 Sensor Features High sensitivity to LPG, iso-butane, propane Small sensitivity to alcohol, smoke. Fast response. Stable and long life Simple drive circuit Application They are used in gas leakage detecting equipment s in family and industry, are suitable for detecting of LPG, iso-butane, propane, LNG, avoid the noise of alcohol and cooking fumes and cigarette smoke Specifications Figure 4.2 : PIN Diagram Available 72

8 Vol. 2, Issue 3,Sepg 2015, ISSN Figure 4.4 : sensitivity characteristics of the MQ-6 Figure 4.5 : Dependence of the MQ-6 on temperature and humidity Sensitivity Adjustment Figure 4.3 : MQ sensor Structure and configuration of MQ-6 gas sensor is shown as Fig.4.3 (Configuration A or B), sensor composed by micro AL2O3 ceramic tube, Tin Dioxide (SnO2) sensitive layer, measuring electrode and heater are fixed into a crust made by plastic and stainless steel net. The heater provides necessary work conditions for work of sensitive components. The enveloped MQ-6 have 6 pin, 4 of them are used to fetch signals, and other 2 are used for providing heating current. Sensitivity characteristic curve Resistance value of MQ-6 is difference to various kinds and various concentration gases. So, when using this components, sensitivity adjustment is very necessary. We recommend that you calibrate the detector for 1000ppm of LPG concentration in air and use value of Load resistance ( RL) about 20KΩ(10KΩ to 47KΩ). When accurately measuring, the proper alarm point for the gas detector should be determined after considering the temperature and humidity influence. 4.3 Software Used ORG 0000H LJMP MAIN ORG 0300H Q1: DB '*LPG GAS DETECT*',0 Q2: DB 'USING MICROCONT*',0 Q3: DB 'MONITRING SYSTM',0 Q4: DB 'GAS FOUND',0 Q5: DB 'EXHAUST FAN ON',0 ORG 0030H MAIN: MOV P2,#00H MOV P0,#00H MOV P1,#0FFH MOV TMOD,#10H MOV A,#38H Available 73

9 MOV A,#0CH MOV A,#06H ACALL MSG MOV DPTR,#Q1 ACALL LCD MOV A,#0C0H MOV DPTR,#Q2 ACALL LCD 1 ACALL MSG MOV DPTR,#Q3 ACALL LCD H1: JNB P1.1,H1 ACALL MSG MOV DPTR,#Q4 ACALL LCD SETB P2.0 SETB P2.1 MOV A,#0C0H MOV DPTR,#Q5 ACALL LCD H2: JB P1.0,H2 H3: JNB P1.0,H3 CLR P2.0 CLR P2.0 SJMP MAIN SJMP $ LCD: CLR A MOVC A,@A+DPTR JZ OUT MOV P0,A ACALL DATA INC DPTR SJMP LCD OUT: RET MSG: MOV A,#01H MOV A,#80H RET CMD: MOV P0,A CLR P2.6 SETB P2.7 CLR P2.7 RET DATA: MOV P0,A SETB P2.6 SETB P2.7 CLR P2.7 RET DELAY1: MOV R0,#20 HE1: MOV TH1,#48H MOV TL1,#0FEH SETB TR1 HERE2: JNB TF1,HERE2 CLR TF1 CLR TR1 DJNZ R0,HE1 RET DELAY: MOV R1,#30H H21: MOV R2,#0FFH H11: DJNZ R2,H11 DJNZ R1,H21 RET V. ADVANTAGE AND DISADVANTAGE 5.1 Advantage 1. It is used in house as LPG leakage detection. 2. It also detects alcohol so it is used as liquor tester. 3. These sensor has excellent sensitivity Available 74

10 combined with a quick response time. 5.2 Disadvantage 1. It is little sensitivity to smoke, then in kitchen it is not perfect response for LPG gas leakage. 2. It works only when at 5Vpower supply is given. 3. Its sensitivity depends on Humidity and temperature. VI. APPLICATION This project is applicable in the following field: 1. Domestic gas leakage detector 2. Industrial Combustible gas detector 3. Portable gas detector 4. Homes 5. Factories 6. LPG storage 7. Gas Cars 8. Hotels and Restaurants VII. FUTURE SCOPE This system can be further enhanced by using Bluetooth to send the alarm messages to user, which supports the realtime application.for industrial purposes mobile robot can be developed for detecting multiple gas concentrations. Addition to gas sensor temperature sensor can also be used which detects the high pressure gas in cylinder pipe, display the alert when high temperature is reached. Detector. It provides safely detection any malfunction of a pressurized gas system. It prevents accumulation of combustible gases so that damage or explosion may not occur. ACKNOWLEDGMENT We wish to express our heartiest thanks to Director Dr.M.P.Singh, for providing us the guidelines to start this paper and the students who helped us a lot. REFERENCES [1]H.Huang, H.Bainand S.Zhu, A Greenhouse Remote Monitoring System Based on GSM, in Proc. of IEEE International Conference on information management, pp ,2011. [2] A Wireless Home Safety Gas Leakage Detection System: Luay Friwan, Khaldon Lweesy, Aya Bani- Salma, Nour Mani. IEEE [3] Automatic LPG Booking, Leakage Detection And Real Time Gas Measurement Monitoring System: B. D. Jolhe, P. A. Potdukhe, N. S. Gawai. [4] Hanwei Electronics Co. Ltd, MQ 5 sensor Datasheet. [5] GSM: Architecture, protocols and services by Jorg Eberspacher, Christian, Hansjoerg vogel, Christian Hartmann, John Wiley Son Ltd, [6] Rajkamal, Embedded Systems: Architecture, Programming and Design, Tata McGraw-Hill Education VIII. CONCLUSION I have finally succeeded in making the Microcontroller Based Propane Gas Available 75

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