Study On Temperature Of Water Released From Multi-level Side Intakes

After reservoir built, as the water dynamics and water heat storage structure changed, the vertical water temperature in the reservoir will present the obvious stratification. Water temperature delamination will lead to low temperature in a relatively stable state of the lower reservoir water all the year. Low temperature water released from reservoirs has an adverse impact on the aquatic ecosystem and agricultural irrigation.In order to control the water temperature released, stop log gate intake, multi- level orifice intake and floating point intake are often used in thermally stratified reservoir in the engineering. The accurate simulation and prediction of temperature of water released, has guiding significance to the stratified water solution.In this paper, we have studied the temperature of water released from multi- level lateral intake by simulation of the distribution of water temperature based on the background of a thermally stratified reservoir through experiment. And used the numerical simulation software FLUENT to simulate the temperature of water released from the reservoir and studied the law of water flow near the intake. The main research contents and achievements of this paper include the following aspects:(1) Introduced the formation mechanism of thermally stratified reservoir, the harm of low temperature of water released, discharge cold water harm reduction effect and corresponding measures of common multi- level withdrawal. Research methods of reservoir temperature of water released are classified and summarized.(2) Based on the background of a thermally stratified reservoir, with design flow of water intake unchanged, changing the submerged depth of water intake in turn, the temperature of water released of different submerged depth of water intake are compared. The results show that the smaller the submerged depth of water intake, the higher temperature of water released. The greater difference of the surface and bottom temperature of the reservoir, the great margin increased of the temperature of water released. With design submerged depth of water intake, changing the water draw rate in turn, the temperature of water released water of different water draw rate are compared. The results show that the smaller the water draw rate, the lower the temperature of water released.(3) Based on the FLUENT, established the numerical simulation method of water temperature. Simulated the temperature of water released with the same water draw rate and different submerged depth, and compared with test results. Results show that numerical simulation by FLUENT for the temperature of water released can be perfect, and that method can be used to predict the temperature of water released.(4) For the multi- level lateral intake, we used the FLUENT to study the flow field near the intake, results show that the extraction of surface water related with the water temperature distribution. Water released range with submerged depth increases decreases, but cannot extract the deep water all the conditions. In the same conditions, the water intake in surface is more than the lower.