Ventilation Model Experiment And Research Of Air Current Properties Of Longtan Hydropower Station's Underground Houses

Longtan, as the largest underground hydropower station, the ventilation balance situation of complicated cavities and tunnels, the flow characteristic of air-current in gallery, and the probability of utilizing natural ventilation for energy efficiency and environment protect, of which, has been concerned extensively and specially. This thesis combined with the commissioned scientific research about ventilation model experiment of Longtan hydropower station's underground houses, involves from document retrieval, theoretical analyses, and model design to accomplishing the experiment, then to the contrast between antitype and model, and finally makes the analyses and research of ventilation balance situation, flow characteristic of air-current and natural ventilation in depth. The conclusion which achieves in the experiment has practical engineering value and will make reference for others. By researching and reading plenty of document and scientific reports, we find beforetime research mainly focus on air-flow organization, characteristic of thermal environment and impedance calculation etc. however, such complicated tunnels are absence. With the development of social construction, the scope of hydropower station expands increasingly; therefore it is very important to research of ventilation balance and characteristic of air-flow. Based on the theoretical analyses and three laws of similarity, this thesis applies law and equation analysis method to deduce the similarity rules and scales for different stage experiments. The geometric scale 1/20 is considered, we have accomplished the model design and making, experiment equipment debugging and adjusting step by step. All of above make a stable basic for developing test. The model experiment is divided into cold and heat condition experiment: Following Re similarity rule and without heat resource, it analyses condition of ventilation balance, impedance of key location and system access, and tests model design and air vent setting from the angle of air-flow and workshop construction. With the variation of equipments run-condition and outdoor meteorological condition, we study temperature field, natural ventilation and impedance in heat condition. It is divided into natural and mechanical ventilation experiment, and I emphases on the change regular of natural ventilation in winter. Through deducing the antitype, the thesis concludes the condition which adapt to Longtan for natural ventilation and some adjustment methods. This paper mainly researches air-flow performance and air-volume balance, on the basis of model experiment. Firstly, according to theory of tunnels networks ventilation and combining experiment results, all-round analysis study of balance condition has been carried out in view of plant's construction and air vent setting. Secondly, the factor of air-flow vortex has been expounded through applying circumferential motion to analyzing air-flow motion properties in cable shaft. Finally, it analyzes the natural ventilation condition by the principle of natural ventilation, and develops changing regular of natural ventilation and some measures which can strong it.