BACKGROUND

An LPG gas sensor detector is use to detect the presence of liquid petroleum gas leakage that may be source of risk and help to avoid information sent to fire station being delayed if any accident happened.  It will detect the presence of gasses using MQ2 sensor, if the sensor detect the level of gasses is exceeding the normal level it will send an information through the phone apps through Internet of Thing (IOT).

Gas sensor MQ2 is a sensor that detects gases, specifically hydrogen (H2), Liquid Petroleum Gas (LPG), Methane (CH4), Carbon Monoxide (CO), Alcohol, Propane, Smoke at the atmosphere. 

DHT11 is use to detect an increment of temperature if the fire happens, it will send an alert message through android apps and location via GPS through IOT to the nearest fire station. It is used to sense a high temperature or positive change of temperature and it will send a pulse to microcontroller. This DHT11 sensor not only contains calibrated digital outputs of temperature but it also contains calibrated digital signal of humidity. This sensor contains resistive sense of wet components and an NTC temperature measurement devices and connected with a high performance 8-bit microcontroller.

PROBLEM STATEMENT

Liquid Petroleum Gas (LPG) is a highly flammable chemical that consists of mixture of propane and butane. LPG is used for cooking at home, restaurant, and certain use for industry. They have certain weaknesses that make the gas leakage occur. The leakage of gases only can be detected by human nearby and if there are no human nearby, it cannot be detected. But sometimes it cannot be detected by human that has a low sense of smell. Thus, this system will help to detect the presence of gas leakage.

Furthermore, gas leakage can cause fire that will lead to serious injury or death and it also can destroy human properties. This system was developed by using IoT to give real-time response to the user and the nearest fire station.

OBJECTIVE

• To build a system that can detect the liquid petroleum gas leakage.
• To detect the changes of temperature caused by fire.
• To send the information to the nearest fire station through Internet of Thing (IoT).

SCOPE

The scope of this project had been performed in order to achieve the objectives of this project.  Design and build a prototype of an LPG leakage detector controlled by Arduino Uno using MQ-2 gas sensor to detect the presence of gas leakage and DHT-11 temperature sensor. To give the real time response, Espresso lite V2.0 was used as Wi-Fi module and Blynk act as software that use to display all the reading.

This system can be implemented in residential area, small industries and restaurant.  Besides that, this system also exposes to the community about the important of the LPG leakage detector to be used because it can help to avoid any dangers of gas leakage that not only can give effect to the user but to the other person too.

OVERVIEW

As the figure show that there are 2 input sensors which is MQ-2 gas sensor and DHT11 temperature sensor, 2 microcontrollers which is Arduino Uno and Espresso Lite V2.0 and two output which is 2X16 line LCD display and Blynk. Figure 3.2 shows overview of the Project.

Refer to the figure shows that Arduino Uno acts as microcontroller and espresso as a Wi-Fi module. The TX, RX are connected to digital pin D2 and D3, while the GND and VIN connected to the GND and 5V pin to the Arduino Uno board. For the MQ-2 sensor and DHT-11 sensor is connected to the pin A0 and D4 as the input to the microcontroller. The LCD display the pin of SCL and SDA are connected to the pin A5 and A4.

RESULTS & DISCUSSION

The results obtain from the implemented of the gas leakage system. The lighter was used as a gas that be detect by the detector and using the hairdryer to get the changes of the temperature. The response of the reading was obtained using the phone application blynk and the liquid crystal display. The sensitivity of the MQ-2 sensor to detect the concentration of the gas is by changing the sensor resistance value. The resistor value obtains from the serial monitor display by Arduino Ide.

The resistor value (RO) that be testing is from 6.00 Ω to 9.30 Ω. From the result obtained, the relationship between the resistance value and the concentration of gas per time. The result that show by the Blynk application is real-time response. The MQ-2 sensor not only detect the concentration of the gas but it’s also detect the concentration of the smoke. The result of the relationship was showed in table 4.1 and table 4.2.

The DHT-11 was testing using hairdryer to detect the changes of the temperature. Based on the result that obtained the notification of the system will alert the user when the temperature exceeds the value of 30^oC. This experiment is to assume the condition if the fired occurred.

The experimental was setup as shown in figure 4.1. This system has a simple implemented circuit and the output of the system shown in the figure 4.2, 4.3, 4.4, 4.5 and 4.6 as the result obtained by Blynk the reading of the concentration gas will safe at the green level and the meter will turn to red colour if the system at the dangerous level or exceed 100ppm. For the smoke concentration it will be safe or at green level if the reading below 100ppm and it will turn to red level if the reading exceeds the 100ppm.

The result for the changing temperature based on the figure 4.4, 4.5, and 4.6 it will be at green level or safe level if the reading below 29^oC and it will turn to the red level or dangerous level if the reading exceeds 32^oC.

Experimental setup.

Concentration of gas at safe (green on the left) & dangerous (red on the right) level. 

Temperature at safe (left), medium (middle), & dangerous (right) level.

Recording to the Table 4.1 and Table 4.2 the higher the value of resistance that adjusted by potentiometer, the low sensitive for the MQ2 gas sensor to detect leakage gas. Based on the Figure 4.2, 4.3, 4.4, 4.5 and 4.6 the project was success because the system can detect the leakage of gasses and the changes of temperature.

The concentration of gas and smoke reading changes the colour from the green level or safe level to the red level or dangerous level when the reading of the concentration in ppm unit is more than 100ppm. While the meter reading for the temperature changes from safe level or green to the red when the reading of temperature exceeds 32^oC.

CONCLUSION

This gas leakage system can be applied for household safety and many other applications in the industry. Any leakage can be recognized through the receiver module and automatically will convey the information to the firefighters. Since the system being monitored 24 hours by the Fire Station therefore this system may avoid the dangerous of the leakage gas.