煤自燃倾向性氧化动力学测试系统及自动控制

发布时间：2018-02-12 04:39

本文关键词： 煤自燃倾向性氧化动力学测试测试炉煤样反应罐自动控制系统　出处：《中国矿业大学》2013年博士论文　论文类型：学位论文

【摘要】：煤自燃是我国煤炭行业生产中的重要灾害之一，不仅造成国家能源的严重浪费，同时还会引发煤尘瓦斯爆炸，给煤炭行业的安全生产带来恶劣的影响。因此，煤炭行业相关部门对煤自燃的防治一直高度重视。煤的自燃倾向性测试又是煤自燃防治的基础和依据。我国煤自燃倾向性测试的研究水平较国外先进水平还很薄弱，在测试方法及测试技术手段上还有不足之处。为此，本论文对煤自燃倾向性的氧化动力学测试系统的关键技术展开研究。首先，对不同物理尺寸的煤样反应罐内气体流场的分布特性进行了深入的理论分析，并运用Fluent软件研究了煤样反应罐内煤样的耗氧特性。通过对比研究得出结论：反应罐内直径越小，煤样罐出口的氧气浓度和流速越小。其次，测试三种典型煤样在煤样罐直径和氧化动力学测试指标之一的交叉点温度之间的关系，通过实验得知，直径越小，交叉点温度越高，最终确定了直径为45mm的圆柱体煤样罐为最佳的物理尺寸。然后，分析了煤样反应罐在测试炉的不同摆放位置对测试炉内部温度场分布的影响，从而确定其相对较优的摆放位置。在煤自燃倾向性的氧化动力学测试系统的研制过程中，高分辨率温度测量是整个测试系统的关键点和难点，要想自动精确控制测试炉的温度，必须首先解决温度测量的高分辨率的问题。通过对温度测量的理论计算和相关的误差因素分析，该测试系统的测温范围在0—400℃范围内，测温分辨率达到0.0067℃。这些指标能达到了国外先进公司（日本岛津公司）的同类仪器的性能指标。整个测试系统的自动精确控制，是另一个关键点和难点，就整个测试系统而言，涉及到的控制问题很多，本文选择了测试炉的温度控制作为研究对象，首先用工程整定法和解方程法分别对控制系统进行数学建模分析，通过对比研究，作者选用了后者。但是本文的控制对象的控制范围跨度大、控制精度要求很高，要建立该控制对象的非常准确的数学模型是非常困难的。鉴于此，选用PID控制算法并优化控制参数P、I、D等，满足控制指标需要，在理论验证可行的基础上，成功实现了相关PID控制器并应用于测试系统。在实验过程中，尤其是温度控制的高温段时，发现控制算法的控制性能下降很多，，已经不能满足系统在此时的控制需求,需要研究并优化新的控制算法。通过对比研究，本文选择了更加智能的模糊控制算法，它的最大优点是在缺乏控制系统数学模型的情况下，达到较优的控制效果。通过对模糊控制器的控制规则和相关控制参数的优化,克服了控制性能严重下降的问题，同时也较好地满足了测试系统的控制需求。就控制指标而言，控温精度可达0.1℃，能够达到国内同类仪器的先进水平。本文研发的测试系统，不仅可以测量交叉点温度和70℃煤样反应罐出口处的耗氧这两个关键指标，还可以对煤与氧气反应气体产物进行快速分析测试，自动取样、进样。测试气体的种类包括：O2、N2、CO、CO2、CH4、C2H4、C2H6、C2H2、C3H8等。测试周期小于8分钟，测试精度高，O2、N2常量气体最小检测浓度≤0.01%，其他种类的微量气体检测精度可达0.1ppm。上位机测试软件可以实时记录系统的各种测试数据，并实时动态曲线显示。并进行相关数据的处理形成给出煤自燃倾向性的氧化动力学测试评价结果。除此之外，该测试系统还可用于煤的绝热氧化实验和煤层标志性气体分析测试等相关实验研究。
[Abstract]:Coal spontaneous combustion is one of the important disasters in China's coal industry in the production, not only caused a serious waste of national energy, but also cause coal dust and gas explosion, brings bad influence to the safe production of the coal industry. Therefore, prevention and control of coal spontaneous combustion of the coal industry. The relevant departments attach great importance to direct test of coal spontaneous combustion tendency is the foundation and basis of the coal spontaneous combustion. The research level test of coal spontaneous combustion in China tend to foreign advanced level is still very weak, in the means of testing method and testing technology are inadequate. Therefore, this thesis launches the research on coal spontaneous combustion in the key technologies of the oxidation kinetics testing system.
First of all, the distribution characteristics of the gas flow field of coal samples of different physical dimensions of the reaction tank in an in-depth theoretical analysis, the oxygen consumption characteristics and the use of Fluent software to study the coal sample in the reaction tank of the coal sample. Through the comparative study concluded that: the smaller the diameter of the reaction tank, the coal tank oxygen concentration and flow rate of export the smaller. Secondly, three kinds of typical coal sample testing in the relationship between the cross point temperature test index of coal tank diameter and oxidation kinetics, the experiments show that the smaller diameter, cross point temperature is higher, and ultimately determine the diameter of cylinder coal tank for 45mm. Then the best physical size and analysis of the different position of coal in the reaction tank testing furnace for the test furnace internal temperature field distribution, so as to determine its relatively superior position.
In the development process of oxidation kinetics testing system of coal spontaneous combustion tendency in the high resolution temperature measurement is the key point of the whole testing system and difficult to accurately control the temperature of furnace automatic testing, we must first solve the problem of temperature measurement with high resolution. Through the calculation of the temperature measurement theory and related factors analysis of error the test system, the measurement range of 0 to 400 DEG C, the temperature reached 0.0067 degrees. The resolution of these indicators can reach the advanced foreign company (Shimadzu Corporation) performance index of similar instruments. Automatically and accurately control the whole test system, is another key point, the whole test system, control the problem involves a lot of, this paper chooses test furnace temperature control as the research object, first used for tuning the reconciliation equation method were used to control system mathematical modeling points Through the analysis, comparative study, the author chooses the latter. But the control range of the control object of the span, the control precision is very high, very accurate to establish a mathematical model of the control object is very difficult. In view of this, the PID control algorithm and optimization of control parameters P, I, D etc., meet control index, in the theoretical verification feasible on the basis of the successful implementation of the PID controller and its application in test system. During the experiment, especially high temperature section temperature control, found that the control performance is far less, has been unable to meet the needs of the system in the control of the need to study and optimize the control algorithm. Through the comparative study, this paper chose the fuzzy control algorithm is more intelligent, its biggest advantage is the lack of the mathematical model of the control system under the condition of the optimal control effect is achieved through the fuzzy control. The control rules and optimization of related control parameters overcome the serious decline of control performance and satisfy the control demand of test system. For control index, the accuracy of control temperature can reach 0.1 degrees, and it can reach the advanced level of similar instruments in China.
The test system developed in this paper, not only can the two key indexes of oxygen consumption measurement crossing point temperature and 70 DEG C coal reaction tank at the exit, but also on the coal and oxygen gas products for rapid analysis testing, automatic sampling, sample test gas. Including types: O2, N2, CO, CO2. CH4, C2H4, C2H6, C2H2, C3H8 and so on. The test cycle is less than 8 minutes, high test precision, O2, N2 constant gas minimum detectable concentration is less than 0.01%, other kinds of trace gas detection accuracy of 0.1ppm. test software can real-time recording system test data, and real-time dynamic curve display and processing. The relevant data form results in spontaneous combustion of coal. The oxidation kinetics of testing and evaluation. Besides, the testing system also can be used in experimental study of gas analysis test and adiabatic oxidation of coal. Coal seam

【学位授予单位】：中国矿业大学
【学位级别】：博士
【学位授予年份】：2013
【分类号】：TD752.2

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