The Research On Optimization For HVAC System Design Scheme In Underground Hydropower Station

As a renewable energy, hydropower has a small impact on environment. Base onthe background of the global energy crisis, hydropower is vigorously developed inChina, giving rise to the construction of hydropower station. HVAC system inunderground hydropower station is aimed at controlling thermal and humid environment,to ensure the normal and stable operation of process equipment and comfort workingenvironment of staffs.Through times of test experience and reading related literature, I realized that thereexist some problems when designing HVAC system in the underground hydropowerstation. For example, the understanding for characteristics of equipment heat dissipationis not enough, which results in larger calculated value about the heat load. Airprocessing schemes are selected and system design air volume is calculated bothaccording to experience at present, as the methods are not clear. These problems arelikely to lead to the consequence that system equipment capacity and demand do notmatch. Therefore, the optimization for system design scheme is discussed and studied inthis paper, to find a more reasonable and scientific way to calculate the heat load, to putforward the method to select the optimal air processing scheme and to calculate designair volume. The work presented in this paper is financially supported by NationalNature Science Foundation of China titled by Formation mechanism of thermal andmoist environment in deeply buried underground hydropower station and it’senergy-saving control strategy (Project No.51178482).The effect and working time of equipment in hydropower station is summarized. Inaddition, three kinds of law of equipment heat dissipation and the characteristics of heatdissipation distribution in each site of hydropower house are summed up. Meanwhile,the characteristics of heat transfer about equipment are analyzed, revealing the relationbetween heat produced by equipment and heat load. Based on the existing problems ofheat load calculation, an accurate formula to calculate heat load is put forward. Thisformula can reflect the actual equipment working time and heat transfer process, whichmakes the calculated value more close to the real value.8feasible types of air processing schemes are summarized and factors affecting thedesign air volume are analyzed. Moreover, according to design temperature andhumidity parameters and the heat balance equation, the methods for determining the design air volume and air processing equipment capacity corresponding to various airprocessing schemes and ventilation process are also deduced.Based on technical and economic evaluation index, such as feasibility, regulatory,environmental impact, investment, energy consumption, operation cost and so on,comprehensive comparison of various air processing schemes is made, so as to sum upfactors influencing the scheme selection. And the various factors, namely the outdoorinlet air parameters, the hot and wet processing capacity of underground tunnel and heatload are analyzed. Then the optimization method for air processing schemes is proposed.Finally, with Baihetan hydropower station as an example, the air processing scheme forthis station is selected using the optimization method mentioned above. This schemeand the other schemes are compared, which shows that the scheme selected using theoptimization method is the most scientific. Therefore, the optimization method for airprocessing schemes is viable and reasonable.