颗粒流靶传热问题研究与设计

发布时间：2019-02-09 19:01

【摘要】：靶装置是一类用途广泛的科学研究装置,为了满足科学技术进步对实验条件提出的越来越高的要求,对于能够承受高功率靶装置的需求也越来越迫切。本工作以加速器驱动次临界系统项目为基础对于一种新型靶的传热流动问题及设计进行了研究。这一新型靶方案采用颗粒作为靶材料,通过颗粒在重力作用下的密相流动将沉积在靶材料中的束流能量进行移除,因而称为DGT(Dense Granular flow Target),目前研究认为这种靶方案在高温耐受、材料相容、运行可靠性与稳定性等方面具备更好的性能,并且有望实现更高的束流作用功率。颗粒材料之所以能够作为靶材料使用,是与其传热特性分不开的,但颗粒材料的传热过程较为复杂,存在多种机制并存的过程。本文第二章通过对于颗粒材料传热实验与理论研究较为系统的回顾,阐述了影响颗粒体系传热的因素以及热传导系数计算的方法。这一部分工作为颗粒在作为靶材料应用时的设计选择与性能评估提供了基础依据。与液态金属靶丰富的设计运行经验不同,使用颗粒材料作为传热工质的靶装置尽管在理论上是可行的,但在具体的实施上仍需要很多工作。而决定靶装置能否有效实施的重要一方面是实际设计结构情况下的流动传热相关问题,本文中所阐述的内容正是本人对这一问题的工作。对于这一问题的研究不仅需要对于个别物理问题的模拟研究,同样需要建立研究装置的实验支持,因而通过计算、实验、模拟等方法对一种颗粒流靶设计方案中主要的流动传热问题和相关装置的设计方法做出了研究,将这一靶与另一种受到广泛研究的无窗靶结构进行了对比。对博士期间的原创性工作,本文主要从:颗粒流靶性能需要考察的关键流动传热问题研究(第三章),初步验证性装置的系统设计与装置搭建运行(第四章),以及无窗流体靶设计问题及其与颗粒流靶的对比(第五章)进行了阐述。在关键问题的研究方面,本工作主要着眼于靶段设计对于总体流量的影响、靶段颗粒的堆积状态、束流作用区域的颗粒流动状态等方面。通过研究结论对于靶运行状态的支持,建设了与电子束耦合的颗粒流靶完整循环回路。这一循环回路实现了循环稳定运行,并与束流沉积模拟预测得到的热效果相符合。为了进一步阐明这一靶设计的热耦合与流动特点,将这一靶装置与液态金属靶装置在热耦合区域流动与设计方法等方面进行了比较。研究结论表明,DGT方案以流动颗粒材料作为靶的工质材料是能够胜任靶系统所需要的载热传热需求的。从对于装置性能起到重要影响的束流耦合区域流动传热层面而言,颗粒物质相比于传统的液态金属更易于实现,并在流动和传热的稳定性方面有一定的优势。同时,针对项目需求和研究需要,在研究工作中设计、搭建、并成功运行了包括大型无窗靶水模拟回路、电子束热耦合的DGT靶原理性测试装置、以及其他用于流动传热的小型台架和装置。在这些装置的基础上,对系统运行状态关键问题做出了实验性的确证评估,并于模拟结果实现了良好的符合,也为进一步项目计划的实施提供了基础依据。本文第一章为背景综述;第二章为研究课题的相关问题调研;第三至第五章为独立研究内容,其中第五章为对比研究。
[Abstract]:The target device is a kind of wide-purpose scientific research device. In order to meet the increasing demands of the scientific and technological progress on the experimental conditions, the demand for high-power target devices is becoming more and more urgent. This work is based on the accelerator-driven subcritical system project, and the heat transfer flow problem and the design of a new target are studied. This new target scheme uses the particles as the target material, and the beam energy deposited in the target material is removed by the dense phase flow of the particles under the action of gravity, thus known as the DGT (Dense flow Target), which is currently considered to be at high temperature resistance, material compatibility, the operation reliability and the stability and the like have better performance and are expected to achieve higher beam action power. The particle material can be used as a target material, which is separated from the heat transfer characteristic, but the heat transfer process of the granular material is more complex, and a plurality of mechanisms exist. In the second chapter, a systematic review of the heat transfer experiment and the theoretical research of the granular material is reviewed, and the factors that affect the heat transfer of the particle system and the method of the calculation of the heat transfer coefficient are described. This part of the work provides the basis for the design choice and performance evaluation of the particles as it is used as a target material. Unlike the rich design and operation experience of liquid metal targets, the use of particulate material as a target device for heat transfer working fluids, although technically feasible, still requires a lot of work in a specific implementation. The important aspect of determining whether the target device can be effectively implemented is the problem of the flow heat transfer in the case of the actual design structure, and the contents of this paper are the work of the problem. The research on this problem not only needs the simulation research on the individual physical problems, but also needs to establish the experimental support of the research device, The main flow heat transfer problem and the design method of the related devices in a particle flow target design scheme are studied by simulation and the like, and the target is compared with another non-window target structure which is widely researched. In this paper, the key flow heat transfer problem in the performance of the particle flow target is studied (the third chapter), and the system design of the preliminary verification device is in operation with the device (Chapter 4). and the design of the non-window fluid target and its comparison with the particle flow target (chapter V). In the aspect of the research of the key problem, this work mainly focuses on the influence of the target segment design on the overall flow rate, the accumulation state of the target segment particles, the particle flow state of the beam action area, and the like. The complete circulation loop of the particle flow target coupled with the electron beam is constructed by the support of the research conclusion to the target operation state. The circulating loop is used for circulating and stable operation, and is consistent with the thermal effect obtained by the current deposition simulation prediction. In order to further clarify the thermal coupling and flow characteristics of this target design, this target device and the liquid metal target device are compared with the design method and so on. The results of the study show that the DGT scheme takes the flowing granular material as the working medium material of the target, and can be used for the heat transfer demand of the heat transfer required by the target system. the particulate matter is easier to achieve than the conventional liquid metal and has a certain advantage in terms of flow and heat transfer stability from the flow heat transfer level of the beam coupling region that has an important effect on the performance of the device. At the same time, aiming at the needs of the project and the research needs, the design, construction and successful operation of the research work include the large-scale non-window target water simulation circuit, the DGT target principle test device for electron beam thermal coupling, and other small racks and devices for flow heat transfer. On the basis of these devices, the key problem of system operation is experimentally confirmed and evaluated, and good agreement is achieved in the simulation results, and the foundation for further implementation of the project plan is also provided. The first chapter is the background review, the second chapter is the relevant research of the research topic, the third to the fifth chapter are independent research contents, and the fifth chapter is the comparative study.
【学位授予单位】：兰州大学
【学位级别】：博士
【学位授予年份】：2016
【分类号】：O347.7

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