【作者】 李海港；

【导师】 王德明；

【作者基本信息】 中国矿业大学 ， 安全技术及工程， 2013， 博士

【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。更多还原

【Abstract】 Coal spontaneous combustion is one of the important disasters in China coal industry. It will not only cause a serious waste of energy, but also evoke coal dust and gas explosion which brought bad influence to the safety production of the coal industry. Therefore, the relevant departments of the coal industry have always attached great importance to the prevention and control of coal spontaneous combustion. The identification of the propensity to spontaneous combustion is the basis for determination of coal spontaneous combustion prevention. Its importance is self-evident. But, our research on coal spontaneous combustion which compared with foreign advanced level is still relatively weak. Therefore, The paper will study on the key technical problems of testing system for identifying the propensity of coal spontaneous combustion.Firstly, the paper makes a deep analysis of the distribution characteristics of the gas flow in coal samples of different physical dimension of the reaction tank, and study the coal sample reaction tank oxygen consumption characteristics by using Fluent simulation technology. Through the above research, we determine the cylinder coal sample tank of45mm diameter for the best physical size. In addition, also analyze the influence of different location of coal sample reaction tank in the test furnace for testing the distribution of furnace temperature field. Ultimately, we determine the relative optimal placement.In the development process of oxidation kinetics testing system of coal spontaneous combustion, high resolution temperature measurement is the key point of the whole system. Because it is a scientific analysis instrument, the measuring accuracy is very high, And the temperature measurement is the basis of accurate automatic control of follow-up. Through the analysis of the temperature measurement of the theoretical calculation and the error, we design the test system of temperature resolution of0.0067℃in the range of0-400℃。Some indicators meet the foreign progressive Corp(Shimadzu Corporation) performance of similar instruments. Automatic control of the whole testing system is another key point and the difficulty. Speaking of the entire test system, many control problems involved. In the paper, the choice of test furnace temperature control as the object of study. Firstly, we use the engineering tuning method and equation method respectively to the control system mathematical modeling analysis. Through the comparative study, we choose the latter method. But the control objects of the paper, its control range span, control of high precision. It is very difficult to establish an accurate mathematical model of the control object. We use the PID algorithm and the optimization of control parameters P,I,D etc to design controller. Through the theoretical calculation and simulation, the relevant control indicators meet the needs. Based on theoretical verification, we have achieved the PID controller and its application in test system. During the experiment, especially at high temperature range(250-400℃), we found that the control performance of the control algorithm is decreased a lot, it has been unable to meet the demand of the system in the control respect. In order to overcome these defects, we need to study and optimize the new control algorithm. Through the comparative study, we chose the fuzzy control algorithm which has a significant advantage that can achieve better control effect in the circumstances of indistinct mathematical model.The oxidation kinetics method of coal spontaneous combustion tendency is a relatively new method. But the shortest coal spontaneous combustion period and the parameters used more widely. Through the study of the relation between the test data and the shortest coal spontaneous combustion period, the paper can more accurately estimate the shortest coal spontaneous combustion period, and integrate it into the test software which developed by author. It is very good to expand the application field of the test system and shorten the time of test period and the complexity of the shortest coal spontaneous combustion.更多还原