安全阀流量检测新方法研究

发布时间：2018-02-09 23:00

本文关键词： 安全阀流量实验研究数值模拟　出处：《华南理工大学》2011年硕士论文　论文类型：学位论文

【摘要】：安全阀在承压设备,例如锅炉压力容器、压力管道等系统中得到广泛的应用,它是一种用来防止压力超过允许的极限值,确保生产系统正常运行的安全装置。工业生产的各个行业中都广泛应用了安全阀,其正常动作对于带压设备的安全运行起着十分重要的作用。从安全阀的运行经验可知,安全阀在使用过程中会出现各种各样的故障,如整定压力随着使用时间的推移会发生某些偏差,或者造成泄漏,阀瓣受粘,弹簧刚度过硬或软化,阀杆不对中等,从而引起严重的后果。即使超压时安全阀正常动作,如果排量不足以泄压,也会对设备安全造成危害。所以对安全阀的流量测量非常重要。在安全阀的超压泄放机理研究中,人们越来越认识到采用数值模拟进行研究的重要性,数值计算的结果能有效地以减少实验研究的规模、次数并能够更深入地探究安全阀介质流动机理。本文通过基本理论分析,尝试建立一种通过阀芯传感器的测试数据来计算安全阀开启过程中泄放量(排量)的方法。在对超压泄放过程流场进行数值模拟,探讨安全阀阀口流动的机理的基础上,得到阀瓣膜在泄放过程中的阀口压力随泄放时间的变化过程,根据阀口流动类似于喷口流动过程的物理特征相似的特点,从而将泄放过程中压力的时间变化曲线与有关瞬时流量关联,最终研究得到了一个有效的流量检测方法。实验室已经研发出一种阀芯传感器式的安全阀,并已经实现采集安全阀开启时阀芯应变数据的功能,本文将这些数据转化成压力数据后绘制成曲线。本文研究如何利用这些曲线得到安全阀泄放流量的检测方法。在现场试验研究中,本课题采用可压缩介质(空气)来进行排放试验,通过阀芯传感器测试数据计算出排量,并与检测法兰计算流量的方法进行了初步的比较,结果证明了使用安全阀上装设的阀芯传感器的测试曲线进行流量测量的可行性和准确性。从而扩展了阀芯膜传感器的应用范围。通过数值模拟和实验研究,发现带有阀膜传感器的安全阀可以在实现安全阀参数校验性能参数的同时,检测并计量安全阀的泄放流量,从而扩大了新型的阀芯膜传感器的应用范围。
[Abstract]:Safety valves are widely used in pressure-bearing equipment such as boilers, pressure vessels, pressure pipes, and so on. They are used to prevent pressure from exceeding the allowable limit. Safety devices to ensure the normal operation of production systems. Safety valves are widely used in various industries of industrial production, and their normal operation plays a very important role in the safe operation of pressurized equipment. Various failures occur during the use of the relief valve, such as certain deviations in setting pressure over time, or leakage, adhesion to the disc, stiffness of the spring, or softening, and the stem is not moderate. This will cause serious consequences. Even if the relief valve works normally during overpressure, if the displacement is not sufficient to discharge the pressure, it will also cause harm to the safety of the equipment. Therefore, it is very important to measure the flow of the safety valve. In the study of the mechanism of overpressure discharge of the safety valve, More and more people realize the importance of numerical simulation. The results of numerical calculation can effectively reduce the scale and number of experimental studies and can further explore the mechanism of the flow of relief valve media. This paper attempts to establish a method to calculate the discharge (displacement) of the safety valve during the opening process by means of the test data of the spool sensor. Based on the numerical simulation of the flow field in the process of overpressure discharge and the discussion of the mechanism of the flow of the relief valve, the variation process of the valve opening pressure with the release time during the release process of the disc membrane is obtained. According to the similar physical characteristics of valve flow process similar to that of nozzle flow process, the time-varying curve of pressure during discharge is related to the relevant instantaneous flow rate. The laboratory has developed a kind of valve core sensor type safety valve, and has realized the function of collecting the valve core strain data when the valve opens. In this paper, these data are converted into pressure data and then plotted into curves. This paper studies how to use these curves to obtain the detection method of relief valve discharge flow. In the field test research, the subject uses compressible medium (air) to carry on the discharge test, calculates the displacement through the valve core sensor test data, and has carried on the preliminary comparison with the detection flange calculation flow method. The results show that it is feasible and accurate to use the test curve of the spool sensor installed on the safety valve to measure the flow, thus extending the scope of application of the spool film sensor. Through numerical simulation and experimental study, it is found that the safety valve with film sensor can detect and measure the discharge rate of the relief valve while verifying the performance parameters of the safety valve. Thus, the application range of the new type of spool film sensor is expanded.
【学位授予单位】：华南理工大学
【学位级别】：硕士
【学位授予年份】：2011
【分类号】：TH134

【引证文献】