The Natural Ventilation Research Of Xiaowan Waterpower Station

Natural ventilation has been applied early in underground buildings as a means ofenergy efficiency, but which is also most complex and difficultly controlled ventilationmode. This paper discusses the laws of natural ventilation of power station as XiaoWanwater power station as prototype through the method of physics analogue modelexperiment. Natural ventilation combined with modern control technology can servepower station better on the base of gaining the fluid mechanics and laws. Based on the theoretical analyses, this paper deduces the similarity rule andsimilarity scales for natural ventilation according to energy conversation law ofhydrodynamics. Natural ventilation model experiment can be carried out in differentheight above sea level and different climate condition from prototype by utilizingsimilarity rule. The model is designed and made as the geometric scale of 1/20 usingother model experiment experience for reference. The prototype parameters such astemperature, pressure, impedance and so on are obtained through model measurement. The model experiment is divided into cold conditionexperiment and heat experiment:the cold condition experiment carries through the flow status analyses, impedancemeasurement and calculating the prototype impedance through model impedance. Heatcondition experiment is divided in winter experiment, transition season experiment andsummer experiment, in these three seasons the natural ventilation flow rate andtemperature of model from one unit to six units operating statuses are measured andtransformed to prototype. The workshop temperatures'changing law as time and space'schanging and the natural ventilation flow rate's changing law as season, operating unitsand outdoor air temperature's changing are obtained. In the end mathematics model is combined with experiment data to probe intonatural ventilation law generally and the calculation equation to obtain the naturalventilation flow rate at any season, any operating status and any time of the day isdeduced; natural ventilation feasibility condition is discussed and some dangeroustemperature points that may easily beyond the control temperature are found; naturalventilation available operating time of the whole year is calculated based on naturalventilation feasible climate condition combined with the typical climate condition ofXiaoWan; the control project of natural ventilation, mechanical ventilation and airconditioning switching reciprocally and commendatory project to improve the floworganization, adjust flow rate distribution and boost natural ventilation up is brought III重庆大学硕士学位论文forward.