白鹤滩水电站出线竖井通风阻力特性

发布时间：2018-05-12 19:46

本文选题：地下水电站 + 出线竖井　；参考：《重庆大学》2014年硕士论文

【摘要】：水电资源的优越性能以及目前严重的能源短缺问题，使得水电站在我国能源建设中据有十分重要的位置。水电站地下洞室群的通风空调及防排烟系统，由交通洞、厂房、母线洞、主变洞、出线道、进风洞、排风洞等洞室和送排风管道系统构成。通风空调及防排烟系统对保障地下电站的生产环境和运行安全十分关键。出线井作为地下水电站通风系统的重要环节，其通风效果的优劣将直接影响到出线井内空气的温度、相对湿度、有害气体浓度、水电站厂房的通风效果和机械设备的正常运行。出线井机械通风，风机的正确选择和合理利用，对保障机电设备正常、安全、高效的运行，值班和设备检修人员的身体健康以及节能降耗都具有十分重要的意义。因此，有必要对出线井的通风流动阻力特性进行详细的研究分析。本文是国家自然科学基金资助面上项目（51178482）“深埋地下水电站热湿环境形成机理与节能调控”的研究内容之一。出线竖井内每隔一定间距布置一层钢格栅，便于工作人员对出线竖井内的设备进行维护与检修。目前尚无可用的参数计算这种特殊通道的通风流动阻力，需采用模型试验等手段获取。模型试验获得的成果真实可靠，但却耗资耗时。本文选用模型试验和CFD数值模拟相结合的方法，研究分析地下水电站出线竖井的通风流动阻力特性，总结出一定的规律，指导今后类似工程的建设。首先通过相似模型试验，得到出线竖井的当量沿程阻力系数λe。然后将CFD数值模拟结果与模型试验结果对照，验证了CFD数值模拟方法对于研究出线竖井通风流动阻力特性的可行性和可靠性。接下来采用CFD数值模拟方法研究分析了出线竖井的断面形状、格栅的结构、格栅的有效通风系数和格栅间距对出线井通风流动阻力特性的影响。研究分析得到： ①出线竖井的断面形状对出线竖井的通风流动阻力特性影响较小； ②格栅的孔口密度只要保持在一定的范围内，格栅的结构对出线竖井通风流动阻力特性的影响在实际工程中可以忽略不计； ③出线竖井内格栅之间的间距一定时，随着格栅的有效通风系数增大，出线竖井的当量沿程阻力系数逐渐减小。格栅的有效通风系数小于0.76时，格栅有效通风系数对出线竖井的当量沿程阻力系数影响较大，随着格栅有效通风系数的增大，出线竖井的当量沿程阻力系数显著下降。格栅的有效通风系数大于0.76以后，随着格栅有效通风系数的增大，出线竖井的当量沿程阻力系数变化平缓，趋于定值； ④格栅为局部构件，当格栅间距较小时，由于局部构件之间相互影响，导致出线竖井内流体的扰动增强，出线竖井的通风流动阻力较大。随着格栅间距增大，格栅之间的影响逐渐减弱，出线竖井的通风流动阻力逐渐趋于定值。以上研究结果表明，出线竖井的当量沿程阻力系数主要取决于格栅的有效通风系数和格栅间距。根据研究结果，，绘制出格栅有效通风系数为0.6—0.9、格栅间距为1de—4de时，出线竖井的当量沿程阻力系数的线算图，便于类似工程通风系统的设计和动力设备的选型。本文还根据研究得到的当量沿程阻力系数和查阅相关资料，计算出白鹤滩水电站出线井的通风流动阻力，并进一步讨论了不同季节，由于室内外空气密度差和出线井进出口高差所形成的热压大小，为工程设计中通风动力设备的正确匹配提供指导。
[Abstract]:The superior performance of hydropower resources and the serious energy shortage at present make the hydropower station have a very important position in the energy construction of our country. The ventilation and air conditioning and smoke control system of the underground caverns of the hydropower station are made up of the tunnels, such as the tunnel, the powerhouse, the bus hole, the main tunnel, the outlet tunnel, the air tunnel, the exhaust tunnel and other caverns and the exhaust and exhaust pipes system. Ventilation, air conditioning and smoke control systems are critical to ensuring the production environment and operation safety of underground power stations.
As an important link in the ventilation system of the underground hydropower station, the outgoing well will directly affect the temperature of the air in the out well, the relative humidity, the concentration of the harmful gas, the ventilation effect of the hydropower plant and the normal operation of the mechanical equipment. The mechanical ventilation of the outgoing well, the correct selection and rational use of the fan, will ensure the mechanical and electrical equipment. It is of great significance to prepare normal, safe and efficient operation, on duty and equipment maintenance personnel's health and energy saving. Therefore, it is necessary to study and analyze the ventilation flow resistance characteristics of the out well. This article is the National Natural Science Foundation Project (51178482) "the heat and humidity of the deep underground hydropower station." One of the research contents of environmental formation mechanism and energy saving regulation.
A steel grid is arranged at every interval in the outgoing shaft to facilitate the maintenance and maintenance of the equipment in the vertical shaft of the outgoing shaft. At present, there is no available parameters to calculate the ventilation flow resistance of this special channel. It is necessary to use the model test and other means. The results obtained by the model test are true, but cost time consuming. With the combination of model test and CFD numerical simulation, the ventilation flow resistance characteristics of the outgoing shaft in the underground hydropower station are studied and analyzed, and some rules are summed up to guide the construction of similar projects in the future.
First, the equivalent drag coefficient of the vertical shaft is obtained by the similar model test, and then the results of the CFD numerical simulation are compared with the model test results. The feasibility and reliability of the CFD numerical simulation method to study the flow resistance characteristics of the shaft shaft ventilation flow are verified. Then the CFD numerical simulation method is used to study and analyze the outgoing line of the CFD. The influence of the section shape of the shaft, the structure of the grille, the effective ventilation coefficient of the grid and the spacing between the grille on the ventilation flow resistance characteristics of the outlet well are studied.
Research and analysis are obtained:
(1) the shape of the outlet shaft has little effect on the ventilation flow resistance characteristics of the outlet shaft.
As long as the aperture density of the grid is kept in a certain range, the influence of the grid structure on the ventilation flow resistance characteristics of the outgoing shaft can be ignored in the actual project.
3. When the spacing between the grille in the outgoing shaft is certain, with the increase of the effective ventilation coefficient of the grid, the equivalent drag coefficient of the vertical shaft decreases gradually. When the effective ventilation coefficient of the grid is less than 0.76, the effective ventilation coefficient of the grid has a greater influence on the equivalent drag coefficient of the outgoing shaft, with the increase of the effective ventilation coefficient of the grid. When the effective ventilation coefficient of the grid is greater than 0.76, with the increase of the effective ventilation coefficient of the grid, the change of the equivalent drag coefficient of the vertical shaft is slow and tends to the fixed value.
4. As the grid is a local component, when the grid spacing is small, the disturbance of the fluid in the shaft shaft is enhanced and the ventilation flow resistance of the outgoing shaft is larger because of the interaction between the local components. With the increase of the grid spacing, the influence of the grid is gradually weakened, and the ventilation flow resistance of the outgoing shaft gradually tends to a fixed value.
The above results show that the equivalent drag coefficient of the vertical shaft depends mainly on the effective ventilation coefficient and the grid spacing of the grid. According to the research results, the effective ventilation coefficient of the grid is 0.6 - 0.9 and the grid spacing is 1De - 4de. The linear calculation of the equivalent drag coefficient of the outgoing shaft is convenient for the similar engineering ventilation system. Design and type selection of power equipment.
In addition, the ventilation flow resistance of the outlet well of baihhan hydropower station is calculated according to the equivalent resistance coefficient and reference data obtained, and further discussion is made in different seasons. Due to the difference of air density between indoor and outdoor and the heat pressure of the exit and outlet of the outgoing well, it is the correct matching of the ventilation power equipment in the engineering design. Provide guidance.

【学位授予单位】：重庆大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TV735

【参考文献】