多热源环状管网仿真实验研究及平台开发

发布时间：2019-04-16 20:50

【摘要】：随着我国城镇化进程的不断推进,居民建筑的规模和集中供热的面积日益增加,多热源环状供热管网依靠其经济效益高、安全可靠和良好的运行灵活性等优点,在旧网改造和新网建设过程中受到越来越多的关注。然而,由于多热源环状管网的拓扑结构较为复杂、管段和热用户的数量较大,目前仍难以系统、准确地掌握其运行工况下的水力特性,特别是管网水力交汇点的具体数目和位置,从而直接影响了各热源的实际供热范围和效果。因此,对多热源环状供热管网来说,在明确水力交汇点数目和位置的基础上,系统分析供热管网的水力和热力特性,对实现供热管网的水力和热力平衡具有重要研究意义和应用前景。首先,本文基于流体网络分析法,并以图论为基本理论,利用基尔霍夫定律、管路特性方程和环能量方程,在对多热源环状管网中的水力交汇用户进行虚拟分割的基础上,以多热源环状供热实验管网为例,重点分析了不同类型公共管道的简化处理过程。即针对公共管道上是否存在用户,以及存在用户时是否存在水力交汇用户的不同情况,提出了公共管道断开省略、两端点设置虚拟用户或虚拟热源等相应的水力建模方法。在此基础上,系统地提出了具有普适性的多热源环状管网的水力建模方法和步骤,并以搭建的多热源环状供热实验管网为基础,通过MATLAB软件,分别建立了单热源双环、双热源双环和三热源三环供热实验管网水力仿真模型。其次,利用上述三种不同的水力仿真模型和相对应的供热实验管网,对单热源双环的一种变工况、双热源双环的理想工况和两种变工况以及三热源三环的理想工况分别进行了建模仿真和实验研究,重点分析水力交汇用户的数目和位置,以及各用户压差和流量的异同,并在考虑仪表测量误差的基础上进行误差分析。结果表明,在5种工况下,用户压差的仿真数据与相对应的实验数据的相对误差绝对值的最大值分别为0.42%、2.83%、2.40%、3.17%和0.98%,用户流量的仿真数据与相对应的实验数据的相对误差绝对值的最大值分别为1.96%、2.07%、3.60%、2.18%和1.00%,验证了该仿真模型的有效性和准确性,进而证明了本文建模方法的合理性和适用性。然后,为了更加系统、高效地进行多热源环状供热管网的水力工况分析,本文在已搭建的多热源环状供热实验管网及其水力仿真模型基础上,利用MATLAB GUI建立一个系统、简洁的多热源环状供热实验管网水力仿真平台,并生成相应的可执行文件。平台界面友好,使用简单,利用该仿真平台,可以对供热实验管网三种供热模式下的水力仿真模型的理想工况和变工况进行仿真和研究,并能与相应实验数据进行比较分析,进而促进对多热源多环供热管网的水力工况进行更系统高效的分析与研究。最后,为了进一步研究管道散热损失对集中供热系统热力平衡和节能降耗的影响,本文采用流体网络分析法,考虑散热损失,建立了单热源枝状管网(一次网)的热力仿真模型。基于管网质量平衡和能量平衡,采取质调节和量调节,满足末端用户热需求,分析比较了该管网仿真模型的五种热力工况。仿真结果表明,在一个供暖期(120天)内该模拟管网由散热损失引起的热量损耗最少增加6.42×104GJ,同时,在满足末端用户热需求的前提下,热力平衡比水力平衡至少节能1.79×10~2GJ。
[Abstract]:With the development of the process of urbanization in China, the scale of the residential building and the area of the central heating are increasing, and the multi-heat-source annular heat-supply pipe network has the advantages of high economic benefit, safety, reliability and good operation flexibility. More and more attention has been paid to the transformation of the old network and the construction of the new network. However, because the topological structure of the multi-heat-source ring-shaped pipe network is more complex, the number of the pipe section and the hot user is large, the system is still difficult to be systematically and accurately controlled, in particular the specific number and the position of the hydraulic pressure point of the pipe network, So that the actual heat supply range and the effect of each heat source are directly affected. Therefore, on the basis of determining the number and position of the water-supply pipe network, the hydraulic and thermal characteristics of the heat-supply pipe network are systematically analyzed on the basis of specifying the number and the position of the water-supply pipe network, and the hydraulic and thermal balance of the heat-supply pipe network has important research significance and application prospect. First, based on the fluid network analysis method, and based on the theory of the basic theory, the Kirchhoff's law, the pipeline characteristic equation and the ring energy equation are used, on the basis of the virtual division of the hydraulic junction user in the multi-heat source ring-shaped pipe network, the multi-heat source annular heat supply experimental pipe network is taken as an example, The simplified process of the common pipeline of different types is analyzed. Namely, whether a user exists on a common pipeline and whether there is a different situation of a hydraulic convergence user in the presence of a user, and a corresponding hydraulic modeling method such as a virtual user or a virtual heat source and the like is arranged at two ends of the common pipeline. On the basis of this, the hydraulic modeling method and the step of the universal multi-heat-source ring-shaped pipe network are put forward, and the single-heat-source double-ring is established by the MATLAB software based on the built multi-heat source annular heat-supply experimental pipe network. Hydraulic simulation model of double-heat-source double-ring and three-heat-source three-ring heat-supply experimental pipe network. Secondly, using the three different hydraulic simulation models and the corresponding heat supply experiment pipe network, the model simulation and experimental study of one variable working condition of single heat source double ring, the ideal working condition of double heat source double ring and the ideal working condition of three-heat source three-ring are respectively carried out, The number and position of the hydraulic cross user and the difference between the pressure and the flow of each user are analyzed, and the error analysis is carried out on the basis of the measurement error of the instrument. The results show that the absolute value of the relative error of the user pressure difference is 0.42%, 2.83%, 2.40%, 3.17% and 0.98%, respectively, under 5 working conditions. The simulation data of user traffic and the relative error absolute value of the corresponding experimental data are 1.96%, 2.07%, 3.60%, 2.18% and 1.00%, respectively, and the validity and accuracy of the simulation model are verified, and the rationality and applicability of the modeling method are also proved. Then, in order to make a more systematic and efficient analysis of the hydraulic working condition of the multi-heat source annular heat supply network, this paper establishes a system using the MATLAB GUI on the basis of the established multi-heat source annular heat supply experimental pipe network and the hydraulic simulation model. The compact multi-heat source annular heat supply experimental pipe network hydraulic simulation platform and the corresponding executable file are generated. The platform interface is friendly, the use is simple, the simulation platform is utilized, the ideal working condition and the variable working condition of the hydraulic simulation model under the three heating modes of the heat supply experimental pipe network can be simulated and researched, and the comparison and analysis with the corresponding experimental data can be carried out, And further, the hydraulic working condition of the multi-heat source multi-ring heat supply pipe network is promoted to be analyzed and researched more efficiently. Finally, in order to further study the influence of the heat dissipation loss on the heat balance and energy saving of the central heating system, this paper adopts the fluid network analysis method to consider the heat dissipation loss and establishes the heat simulation model of the single-heat-source heat-dissipation pipe network (primary network). Based on the mass balance and energy balance of the pipe network, the quality adjustment and the quantity adjustment are adopted to meet the heat demand of the end users, and the five thermal conditions of the pipe network simulation model are analyzed and compared. The simulation results show that, in a heating period (120 days), the heat loss caused by the heat dissipation loss is at least 6.42-104GJ, and at the same time, the heat balance is at least 1.79-104GJ at least energy-saving and 1.79-104GJ under the premise of meeting the heat demand of the end users.
【学位授予单位】：山东建筑大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TU995.3

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