大型复杂天然气管网水/热力双层分治高效GPU并行模拟方法研究

The hydraulic-thermal simulation technique of natural gas pipeline network plays a significant role in energy-saving optimization and safety management of natural gas pipeline network. With the rapid construction of large-scale long-distance natural gas pipeline and urban natural gas pipeline network, the scale of the national natural gas pipeline network increases quickly and its network topology is more complex. Unfortunately, the computation efficiency of the current simulation technique is low for large-scale complex natural gas pipeline network, which cannot meet the requirements of national natural gas pipeline network management, such as optimization operation, intelligent scheduling. In this project, the computation efficiency for large-scale complex natural gas pipeline network is significantly improved from two aspects: (1) The proposed "Components Divide and Conquer"(CDC) approach is going to be extended to a "Sub-networks Divide and Conquer"(SDC) approach in which basic units are sub-networks rather than components. Subsequently, an integrated bi-layer divide and conquer strategy is developed, in which SDC is utilized for pipeline network while CDC for sub-network. In this way, the simulation efficiency can be significantly improved. (2) Combined the bi-layer divide-and-conquer with the block-thread parallel platform GPU, the efficient parallel simulation technique is developed to further improve the simulation efficiency of large-scale complex pipeline network. With the efforts of this project, the simulation efficiency of the large-scale complex pipeline network is promising to improve more than 50 times than the famous commercial software SPS. Furthermore, the hydraulic/thermal operation characteristic can be clarified using the developed efficient simulation technique, which can provide powerful supports for the operation and management of the nationwide natural gas pipeline network.

天然气管网水/热力模拟技术是天然气管网的节能优化运行和安全稳定供气的核心基础技术，一直是相关科研人员的研究热点。但对大型复杂管网求解效率较低的问题仍未得到完善解决，无法满足我国全国性天然气管网的优化运行、智能调度等的快速计算需求。为此，本项目从两个方面来提高其模拟效率：（1）基于分而治之思想，从管网拓扑结构出发，提出以子网为求解单元的“子网分治”，发展管网“子网分治”和子网“元件分治”的双层分治方法，大幅度提高模拟效率；（2）将双层分治方法与具有多层次并行特点的GPU并行相结合，开发大型复杂天然气管网水/热力高效GPU并行模拟技术，进一步提高模拟效率。通过本项目研究，不仅可实现我国全国性天然气管网水/热力的高效模拟，有望在个人计算机上较国际著名软件SPS快50倍以上，而且基于所开发的高效模拟方法，查明我国天然气管网水/热力运行规律，可为我国大型复杂天然气管网的安全节能运行提供有力理论支持。

为全面提高大型复杂天然气管网水/热力模拟效率，满足我国全国性天然气管网输气工程的需求。本项目基于分而治之思想，从管网拓扑结构出发，开发了基于线性化+水热力去耦管网稳态系统，两层级GPU并行水力系统，基于路径搜索的热力系统的一系列高效模拟方法，大幅度提高求解速度。所开发模拟方法可在几乎不影响计算精度的前提下，较国际著名商业管道仿真软件SPS可提高求解速度50倍以上，为全国性天然气管网的快速模拟提供重要技术支持。基于所开发模拟方法，研究了天然气管网多气源运行特性、供气可靠性、可靠性和经济性的多目标优化等管网运行特性，为天然气管网的节能优化运行和安全稳定供气提供技术和理论支撑。