三峡电站保温保压浇蜗壳二期混凝土装置设计

Design of second stage concrete placement facilities with controlledpressure and temperature for TGP power station's spiral case

要使三峡电站在一年四季各种水头 (水温 )下运行时 ,既要使蜗壳外缘与外围混凝土紧贴 ,又要使蜗壳外围混凝土受力适中 ,尽量减少钢筋配置 ,便于混凝土浇筑 ,保证施工质量。经过大量的分析研究 ,提出用保温保压的办法浇筑蜗壳二期混凝土 ,即浇筑混凝土时的蜗壳中心平面保压水头控制在 70± 1m ,水温控制在 16～2 2℃ ,于是提出了在冬季浇筑蜗壳外围混凝土时 ,蜗壳内的压力水需要加温 ,夏季浇筑蜗壳外围混凝土时蜗壳内的压力水需要降温的问题。介绍了左岸电站充水保温保压浇筑蜗壳外围混凝土的升温装置和降温装置系统设计中几个主要技术问题 ,推导了传热计算公式 ,在此基础上提出加温、降温装置的设计 。

In order to make both the external surface of turbine spiral cases closely contact with the surrounding concrete and the stresses of the concrete surrounding spiral cases be moderate when the Three Gorges Project hydropower station operates at various water heads(water temperatures) in four seasons of the year to reduce reinforcing bars, facilitate concrete placement and guarantee good concrete quality, a construction method of maintaining the temperature and pressure in spiral cases was used for placing the concrete surrounding spiral cases after extensive analyses and studies. That is, during concrete placement the water head at the center level of spiral cases was controlled to be 70±1 m, and the water temperature was controlled to be 16~22℃. For this purpose, the water in spiral cases was to be heated during placing the concrete surrounding spiral case in winter, and was to be cooled in summer. Several key technical problems on the design of the water temperature rising and lowering system for placing the concrete surrounding spiral cases of the Three Gorges left hydropower station are presented. The practical operation has proved that the design of the system is correct.