燃气泄漏扩散数值模拟分析及软件开发

发布时间：2018-08-05 09:19

【摘要】：随着21世纪的第二个十年的到来，城市发展也越来越快，作为配套基础设施的燃气行业得到了空前的大发展。但因为燃气管道铺设的方式、燃气管道材质的问题、供气范围的扩大等多方面因素的影响，燃气泄漏事件是很容易产生的。因此无论从对人员的保护还是经济财产的保护的角度，研究燃气的泄漏扩散规律都是相当必要的，这对减小事故引起的各方面损失有重要的意义。本文梳理了现有的燃气扩散理论，比较分析了风向风速、空气温度、大气因素、燃气物理性质及地面条件等等对燃气泄漏扩散过程的影响。同时为了简化Fluent软件的模拟操作，本文中运用了Fluent的程序日志文件，在.NET操作平台上编写了一个针对Fluent的辅助程序，通过该程序实现了对Fluent软件的数值模拟过程的控制，成功在软件界面整合了各项如扩散模型、物理性质等重要参数设置，简单直观的设置之后在后台调用Fluent进行数值计算，并且能在计算收敛后，生成所需要的云图和矢量图进行观察分析。这就能很好的节约使用人员的设置时间和学习成本，并且对燃气泄漏扩散的模拟具有一定的通用性。最后，通过该自制程序对住宅小区内的燃气管道泄漏导致的燃气泄漏扩散的各种扩散状态进行数值模拟，得到了燃气在不同物理性质下、不同室外风速条件下、不同室外风向下以及不同时间段的浓度、速度、压力分布图，并详细分析了之前各种不同条件下，即风向风速、空气温度、大气因素、燃气物理性质及地面条件等等影响下的燃气泄漏扩散规律。得出如下结论：（1）轻质气体不仅受室外风的作用，也受室外空气浮力的作用，会有很明显的向上扩散趋势，而重气受空气浮力影响较小，会向下并且顺风扩散；（2）室外风是有利于泄漏气体的泄漏扩散的，外界风速越大，泄漏源及其附近地带形成的浓度分布越小；（3）障碍物的存在是降低燃气扩散速度的重要因素之一；（4）风向的变化也会改变泄漏燃气原有的流动规律；（5）模拟区域内的燃气浓度与泄漏时间几乎是成线性关系的，在一定的时间段内，泄漏时间越长，燃气的浓度也就越大；（6）在模拟区域内的燃气泄漏过程，，首先是一个非稳态的泄漏过程，然后随着泄漏时间的慢慢变长逐渐变成一个稳定不变的状态。
[Abstract]:With the arrival of the second ten years in twenty-first Century, the urban development is getting faster and faster. The gas industry, as a supporting infrastructure, has been developing unprecedentedly. But because of the gas pipeline laying, the problem of gas pipeline material and the expansion of the gas supply range, gas leakage is very easy to produce. It is necessary to study the law of gas leakage and diffusion, not only from the protection of personnel or the protection of economic property, which is of great significance to reduce the loss of all aspects caused by the accident.
In this paper, the existing theory of gas diffusion is combed, and the influence of wind direction wind speed, air temperature, atmospheric factors, physical properties of gas and ground conditions on the process of gas leakage and diffusion is compared. In order to simplify the simulation operation of Fluent software, the Fluent program log file is used in this paper, and one of the.NET operating platform is written. An auxiliary program for Fluent is used to control the numerical simulation process of Fluent software. It has successfully integrated various important parameters such as diffusion model and physical property in the software interface. After simple and intuitive setting, it can be called Fluent for numerical calculation in the background, and it can be generated after the calculation is convergent. It is very good to save the time and the learning cost of the personnel, and it has a certain generality for the simulation of gas leakage diffusion.
Finally, through the self-made program, the diffusion of gas leakage caused by gas pipeline leakage in the residential district is simulated. The concentration, velocity and pressure distribution of gas in different outdoor wind direction and different outdoor wind direction under different physical properties and different outdoor wind speed conditions are obtained, and the detailed analysis is made. The law of gas leakage and diffusion under the influence of wind direction wind speed, air temperature, atmospheric factors, physical properties of gas and ground conditions and so on. The following conclusions are drawn: (1) light gas is not only affected by outdoor air, but also affected by outdoor air buoyancy, it will have a very obvious upward diffusion trend, and the heavy gas is floated by air. The influence of the force is smaller and will spread down the wind; (2) the outdoor wind is beneficial to the leakage of the leakage gas. The greater the wind speed, the smaller the concentration distribution of the leakage source and its vicinity; (3) the existence of the obstacles is one of the important factors to reduce the gas diffusion speed; (4) the change of wind direction will also change the original gas leakage. (5) the gas concentration in the simulated region is almost linear with the leakage time. In a certain period of time, the longer the leakage time, the greater the gas concentration. (6) the process of gas leakage in the simulated region is first an unsteady state leakage process, and then gradually changes with the length of the leakage time. Become a steady state.
【学位授予单位】：重庆交通大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TU996

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