Design And Application Of Monitoring Method For Reservoir Bubbles

The complicated hydro logical situation of the river makes it difficult to monitor the bubbles in situ,which results in the unfavorable situation that the research on bubble monitoring methods at home and abroad is in the initial stage of development.Among them,there are few researches on reservoir bubbles,especially in situ bubble monitoring and estimation.But bubbles as one of the most important way to greenhouse gas emissions,the related research and has a profound scientific significance and application value,which in turn makes more and more researchers and relevant scholars into it,to explore the mechanism of bubble problem,including bubble discharge mode and characteristics of time and space,in order to further predict nitrogen oxide and methane and other greenhouse gas emissions and its corresponding gas ratio.However,due to the limitation of methods,many researches are difficult.Based on this research background,the fixed-point bubble monitoring method developed in this paper has extremely important engineering application value.However,due to the patios-temporal heterogeneity of bubbles,fixed-point monitoring is not enough to represent the overall level of the basin.Therefore,spatial measurement should be supplemented.EY60 equipment is mainly used in the field of fish acoustics.In this paper,it is developed for the measurement of bubble space.This method clarifies the relationship between bubble acoustics and depth response in the vertical mode region.The bubble data processing method is also described.On the whole,how to calculate the bubble escape flux of the"artificial lake"in the reservoir and how to evaluate the difference of bubble escape in different reservoirs are the hot and difficult points in the study of reservoir bubbles.Therefore,in this paper,the total amount of bubble escape is estimated through the statistical method and the in-situ water area monitoring and laboratory experiment verification,so that the bubble monitoring method has universal engineering application value,and provides scientific and technological support for the formulation of scientific pollution control measures in the basin and the in depth understanding of the reservoir’s impact on the ecological environment.This paper draws the following conclusions:（1）The fixed point bubble monitoring device based on photoelectric sensing technology can effectively carry out long-term continuous monitoring.The equipment construction process includes device hardware,detection algorithm,software check,original data check and smoothing algorithm check.For its data output and post-processing process,this paper expounds the detailed processing process,and further expands the theoretical research direction and thinking,for later researchers in depth study.（2）The aerial bubble monitoring device based on ultrasonic detection technology can effectively supplement and monitor the spatial continuous bubble data.Its specific operation process is relatively simple,similar to the test fish.But the difficulty lies in the process of data post-processing.Echo-view software is developed in this paper to process bubble acoustic data.The feasibility of this method is proved by the application of relevant acoustic theory.The post-processing method of bubble data includes target strength method and velocity conversion method.（3）After the field fixed point bubble monitoring and analysis of Lan-cang River and Xiang-xi River,the bubble phenomenon can be divided into five categories.These five types correspond to different bubble volume distribution bubble bubble time distribution and bubble radius distribution.Moreover,when the water depth exceeds 35.8m and the temperature is lower than 24.5℃,there is no bubble generated by non-human extrusion.When the temperature is below 25℃,the bubble escape decreases sharply.There is a negative correlation between the escape rate of air bubbles and the water depth.The relationship between time and bubble accumulation is nonlinear.When the water depth is greater than 40 meters,the bubble volume distribution ranges from 0 to 2m L except for a few outlines.When the water depth is less than 30m,the bubble volume distribution range increases,and the large-volume bubble distribution range tends to 20-25m L.The number of small bubbles in deep water is obviously more than that in shallow water.In addition,the bubble volume of deep-water bubbles less than 0.1m L accounts for 69%of the total bubble volume,and the number of bubbles accounts for 82%.Further analysis shows that the number of bubbles and depth are in line with the normal distribution under depth,and the maximum value of bubble number distribution is located at 40m water area.（4）Further put forward the corresponding mathematical model and physical concept,with a view to the initial construction of the reservoir bubble total theoretical equation,so that the bubble monitoring method has universal application value.The results show that the annual bubble release volume and flux of Xiang-xi River at fixed point are 3.274×10⁸L and 0.156L/（a·m²）respectively calculated by the traditional average method.The average air bubble flux during navigation is 0.0124L/（a·m²）,and 3.85×10⁷L bubbles are estimated through the whole basin.In this paper,the bubble growth cycle theory was first developed,and the average bubble flux was calculated to be 458.44L/（a·m²）and the bubble volume was 1.42×10¹²L by mutual checking with the combination of fixed point and navigation.