Choking Flow in Supercritical Fluids

2002年，由10个国家组成的第四代国际论坛确定了六种不同的核电技术，这些技术应该与预计在不久的将来可用的能源转换系统竞争。与现有反应堆相比，新反应堆的相对优势包括运行安全性提高、废物产生最小化、武器扩散风险和温室气体排放降低。为了保持和进一步发展在国际核工业领域的领导地位，加拿大致力于在核反应堆研发国际计划中发挥重要作用。由于加拿大未来的核动力反应堆必须具备运行中换料的能力，因此加拿大核工业认为超临界水冷堆是所有拟议技术中最合适的一种。因此，未来的超临界核动力反应堆的设计将类似于众所周知的CANDU系统。同样重要的是，使用超临界水冷却剂将允许提高整个系统的热效率。因此，超临界核反应堆将通过确保低得多的环境影响，成功地与现有的化石燃料超临界锅炉竞争。加拿大工业界正在考虑到2040年，SCWR技术将取代第三代先进CANDU核反应堆。因此，最近确定了一项研究优先事项，以便开始进行基本调查并收集设计未来核反应堆所需的数据。在此框架下，本提案提出了一个研究计划，旨在实验研究超临界条件下用水呛流现象。为此目的，将建造一个小型超临界水循环进行三方面的研究工作，包括：i)设计和建造一个超临界试验设施，ii)进行调试试验，iii)进行超临界堵塞流实验，数据分析和建模。

In 2002, the Generation IV international forum formed by 10 countries has identified six different nuclear power technologies, which should compete with the energy conversion systems that are expected to be available in the near future. Comparative advantages of new reactors beside the existing ones include enhanced safety operation, minimal generation of waste as well as reduction of both risk of weapons proliferation and greenhouse gas emissions. In order to maintain and further develop a leadership in the international nuclear industry arena, Canada is committed in playing an important role in the nuclear reactor R&D international program. Since future Canadian nuclear power reactors must have the capability of being refueled under operation, the Supercritical-Water-Cooled Reactor is being considered by the Canadian nuclear industry as the most appropriate one among all proposed technologies. Thus, the design of future supercritical nuclear power reactors will be similar to the well-known CANDU system. It is also important to mention that the use of supercritical water coolant will permit to increase the overall system thermal efficiency. Hence, supercritical nuclear reactors will successfully compete with existing fossil fuel supercritical boilers by assuring much lower environmental impacts. The Canadian industry is considering that by the year 2040 the SCWR technology will replace the Generation III Advanced CANDU nuclear reactors. Therefore, a research priority has recently been established in order to start carrying out fundamental investigations and to collect data needed for designing the nuclear reactors of the future. Within this framework, this proposal presents a research program intended to study experimentally choking flow phenomenon using water under supercritical conditions. To this aim a small supercritical water loop will be constructed to carry out a three-fold research work consisting of: i) design and construct a supercritical test facility, ii) conduct commissioning tests, iii) carry out supercritical choking flow experiments, data analysis and modelling.