特高拱坝通水冷却管网智能联控原型试验研究

开展特高拱坝施工期通水冷却管网的智能联控研究,对确保实现精准、高效的大坝混凝土温控防裂具有重要意义。基于白鹤滩特高拱坝通水冷却智能温控实践,本文系统分析了冷却水的温度、流量、流向等参数满足特高拱坝换热防裂的适应条件,提出了混凝土温控冷却水需求的确定方法,定义了供水保证率的量化评价指标。通过在白鹤滩特高拱坝建设现场开展原型生产性试验,提出了通水冷却管网智能联控的方法,并研发了联控系统,克服了人工手动换向的不确定性,实现了对通水冷却管网温度、压力、流量的实时在线监测和通水流向的智能调控,换热效果更好。现场试验揭示了冷却水管网输送的时空规律,结果表明供水水温沿程变化主要受外界气温与管道保温影响;在制冷容量满足需求的前提下,流量供应主要受供水压力支配。本文成果促进了特高拱坝通水冷却管网智能联控全面应用,也可供同类工程设计与施工参考。

Study on prototype intelligent control test of cooling pipeline for a super-high arch dam

Carrying out a prototype intelligent control test of the cooling pipeline of a super-high arch dam is of great significance to ensure accurate, efficient cracking control. Based on the intelligent cooling practice of the Baihetan super-high arch dam, this study systematically analyses the adaptable conditions for heat exchange and cracking prevention of super-high arch dams, including the temperature, flow rate, and direction. The demand determination method of the cooling water is proposed, and a quantitative evaluation index of the water supply guarantee rate is defined firstly. An intelligent control method and system of the cooling pipeline is developed based on conducting prototype tests at Baihetan dam site. The system overcomes the uncertainty of manual control, realizes real-time online cooling monitoring of the temperature, pressure,flow rate,and flow direction. The heat exchange effect is better. The spatial-temporal distribution of the cooling water inside the pipeline is revealed. The test results show that the temperature change of the supply cooling water along the way is mainly affected by the outside air temperature and pipeline insulation. Under the condition that the cooling capacity meets the demand, the cooling water is mainly affected by supply pressure. The study results promote the full application of intelligent cooling pipeline control on a super-high arch dam and may also be applicable to the design and construction of similar projects worldwide.