电厂取水设施运行对水生生物影响与减缓措施 |
Effects of Cooling Water Intake Structure and Its Operation on Aquatic Organisms and Mitigation Measures at Power Plants Using Once-through Cooling System |
投稿时间:2016-10-25 修订日期:2017-07-28 |
DOI:10.15928/j.1674-3075.2017.04.001 |
中文关键词:电厂 冷却水取水设施 直流冷却水系统 闭式循环冷却水系统 撞击 夹带 |
英文关键词:power plant cooling water intake structure once-through cooling system closed-cycle recirculating system impingement entrainment |
基金项目:环保公益性行业科研专项(课题编号:201509074) |
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中文摘要: |
直流冷却水系统电厂从地表吸入大量的冷却水,该设施取水和运行可能伤害冷却水中的水生生物。对于较大的水生生物,其无法通过滤网,若不被移出取水设施,则受滤网的撞击影响;对于小型的水生生物,有可能穿过滤网进入冷凝器冷却系统而受到热应力、机械应力、压应力及杀生剂的影响,即夹带影响。我国直流冷却水系统电厂(尤其是核电厂)的机组数量多、取水量大,取水设施运行的环境影响未得到重视,没有考虑撞击的影响,无相关的缓解措施。美国对直流冷却水系统电厂水生生物的撞击和夹带影响进行了30多年的监测和研究,本文对此进行了系统调研和分析。研究表明:(1)有些电厂取水设施对鱼类、贝类等水生生物的撞击和夹带的负面影响水平是中等,甚至是大的,对生态系统可能造成直接和间接的影响;(2)采用闭式循环冷却水系统替代直流冷却水系统,控制取水通过滤网流速≤0.15m/s,在取水设施外围设置屏障网,采用改进型滤网,设置离岸速度盖等措施,能够有效地降低对鱼类、贝类等水生生物的撞击损失;而对于夹带影响,当前除了采用闭式循环冷却替代技术外,其他措施效果有限,应继续开展相关研究。 |
英文摘要: |
The operation of power plants with once-through (condenser cooling) system requires large amounts of water that are taken directly from surface waters. The aquatic organisms in the surface water are drawn into the intake with the cooling water, some are too large to pass through the debris screens and impinged against the screens; while the others are small enough to pass through the debris screens in the intake will travel through the entire condenser cooling system and be exposed to heat, mechanical stress, pressure stress and biocides before being discharged, this process is called entrainment. Both impingement and entrainment will injure or kill the aquatic organisms seriously during the operations of cooling water intake structures (CWIS). In China, the power plants with once-through cooling system, especially the nuclear power plants have many units, consequently resulting in the need of a larger amount of water from surface. However, few studies have been reported on the adverse impacts associated with CWIS operations, and no studies concerned about the effects of impingement and entrainment on the aquatic organisms. In United States, lots of studies have been carried out for the assessment of environmental impacts from power plant entrainment and impingement of aquatic organism in the past three decades. In this study, we reviewed the results of these studies and the environmental impact controlling measures. It shows as following: (1) the adverse impacts of entrainment and impingement by the operation of CWIS on fish, shellfish and wild life are not even, some impacts are light , some are moderate while some are much serious in a few power plants with once-through cooling systems; The losses of organisms associated with CWIS operations have direct and indirect effects on aquatic ecosystems; (2) The losses of fish, shellfish and wild life impingement are well controlled by replacing once-through cooling system with closed-cycle recirculating system, controlling through-screen velocity lower than 0.15m/s, installing barrier net at the peripheral of the CWIS, using modified travelling screen, or constructing far offshore velocity caps; while, for the effects of entrainment, the only effective controlling method is replacing once-through cooling system with closed-cycle recirculating system. Further study should be carried out to find other effective entrainment controlling methods. |
魏新渝,张琨,熊小伟,王一川,方圆,杨端节,商照荣.2017.电厂取水设施运行对水生生物影响与减缓措施[J].水生态学杂志,38(4):1-10. |
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