Structural Evolution And Mathematical Model Derivation Of Concentric Circles Homogeneous Pool

The regulation mechanism of concentric circles homogeneous pool is not clear,and the structural mathematical model is lack,the engineering design depends on traditional experience.At the same time,the structure and function of the pool is simple and it’s regulation capacity is limited,which limits its application prospect.In this paper,based on the principle of structural decision function and the method of“time traceability”,the way of corridor water distribution and effluent mode of concentric circles homogeneous pool was improved to increase the diversity of the structure and the regulation function,and bypass accident pool to expand the scope of its regulation ability was also considered.We built the mathematical model,simulating the structural characteristics and the regulation process of the evolution structure of concentric circles homogeneous pool,and verified the results with experiment.the conclusions were as follows:（1）Introduces the ratio coefficient of corridor flow,transforming the static regulation process into dynamic regulation process,derived the equation of unequal proportion structure ,the equation of regulation function coefficient under sine wave inlet.We wrote simulation program based on the above equations,the results showed:the regulation function coefficient increased with the increase of the corridors number,and tends to be stable after four corridors;with the increase of the inner radius,the k increases first and then decreased;with the increase of effective water depth,k showed a trend of fluctuation.The experiment results indicated that:the mean relative absolute error of effluent water quality and simulation results was less than 2%with unequal proportion,the experiment regulation function coefficient was 0.89±0.04with optimal proportion,which was higher than the average ratio with 20%.（2）Using orifice flow,the water level is variable,and the pool has the synchronous emulation and adjustment function.Based on the basic formula of orifice flow,starting from the single channel model of continuous wave inflow,we established the synchronous emulation and adjustment mathematical model of the concentric circles water regulation tank;based on the“time traceability”,the limit division,and the water regulation model,we established the load regulation function mathematical model.The results indicated that:when the multiple get from the total water flow and the maximum flow rate of the single corridor division equal to the number of corridors,the equalization effect was achieve best;the equalization effect decreases with the increase of inner radius;with the increase of the height outlet,the regulation effect showed a variation trend,whereas,the outlet height had no effect on the adjustment effect;with the increase of the inlet volume load,the regulation effect increased first and then decreased.The results of the validation test showed that:the mean relative absolute error of effluent water quality and simulation results was less than 3%.（3）Based on the accident water caused by the superposition of high impact rectangular wave and reference sine wave,this paper proposed the concept of"big impact accident and small impact homogenization",established an accident conditioning system for the construction of bypass accident pool and homogeneous pool,derived the system structural equation.Where the total volume of the system was constant,the regulation effect increaseed,and the growth rate gradually decreased with the increase of volume ratio;the regulation effect increased with the increase of accident ratio,and increased with the decrease of mixing ratio.When the accident pool volume was constant,within the scope of the accident ratio>n_smin and also meet the requirements of the load of shock resistance,the mixing ratio has a greater impact on regulation effect;within the scope of the accident ratio<n_smin,the regulation function coefficient decreased with the decreased of effective volume of accident pool,no longer meet the above rules.The results of the validation test indicated that:when the concentration of the rectangular wave crest was 7.5 times higher than that of the sine wave,the mean relative absolute error of effluent water quality and simulation results in the accident regulation system was 9.6%;the regulation function coefficient of accident regulation system was 0.75,higher than the single homogeneous pool with 50%.