摘要随着天然气的大量使用,每一座居民大楼都被天然气所“笼罩”。天然气的普及给公共生活带来了方便,减少了城市的污染,提高了生活质量和效率,但是同时,天然气也是潜在的“危险品”,一旦发生大面积泄漏,处置不及时就可能引发大爆炸,给居民的生命财产安全带来巨大的威胁。面对燃气泄漏而造成的种种事故威胁，我们需要一个解决办法。使用天然气报警器是对付燃气无形杀手的重要手段之一。
    本论文以半导体气敏传感器和单片机技术为核心设计的气体报警器可实现声光报警功能，是一种结构简单、性能稳定、使用方便、价格低廉、智能化的气体报警器，具有一定的实用价值。
其中选用MQ-2传感器实现对气体的检测，具有灵敏度高、响应快、抗干扰能力强等优点，而且价格低廉，使用寿命长。经AT89C51单片机处理，并对处理后的数据进行分析，是否大于或等于某个预设值(也就是报警限)，如果大于则会自动启动报警电路发出报警声音，反之则为正常状态，而且在此设计中我们通过DS18B20温度传感器和AT89C51单片机进行连接，将温度信号转换成单片机可识别的数字信号，经过单片机处理并对其进行分析，最终将温度还有气体的浓度显示在LED的显示管中。8791
关键词  气敏传感器    报警器    单片机    温度传感器   
毕业设计说明书（论文）外文摘要
Title   Design of indoor gas & natural gas alarm based on  51 microcontroller                    
       Abstract
With the wide use of natural gas, each residential towers were "enveloped" by the gas. The popularity of natural gas to public life brought convenient, reduce the city's pollution and improve the life quality and efficiency, but at the same time, natural gas is also potential "dangerous", once produce large leak, disposal not timely could trigger, the big bang to people's life and property safety brought great threat. Facing the gas leak all kinds of accidents caused by threats, we need a solution. Use of natural gas alarm is deal with gas invisible killer one of the important means.
This papers to the semiconductor gas sensors and single chip microcomputer as the core design can realize the gas alarm sound-light alarm functions, is a kind of simple structure, stable performance, easy to use, inexpensive and intelligent gas alarm, has certain practical value.
Among them we choose MQ-2 of gas detection sensor, it has a high sensitivity, fast response, strong anti-jamming capability etc, and the price is low, service life long.  by AT89C51 for processing the data and analysis, whether is equal to or greater than the a default value (that is, the alarm limit), if beyond the limit than it will automatically start alarm circuit warning voice, otherwise conversely for normal state. In this design, we connected DS18B20 temperature sensor and the AT89C51 micr- ocontroller ,it turns the temperature signals into the digital signal which the microcontroller can identify. Finally the temperature of gas will be displayed on the LED display tube.
Keywords ：gas sensor  alarm  single chip microcomputer  temperature sensor
 目录
1.1、课题研究的背景    1
1.2、课题研究的意义    2
1.3国内外研究情况及其发展    2
1.3.1、可燃性气体泄漏报警器种类与结构    2
1.3.2、国内外情况及其发展趋势    2
2 天燃气泄漏报警系统的方案设计    3
2.1方案的选择    3 AT89C51单片机室内煤气天然气泄漏警报器的设计:http://www.youerw.com/zidonghua/lunwen_7250.html