Research On Thermo-hydraulic Behaviors Of Thermal Discharge At Lateral Out Flow Mixing

With the rapid development of China’s power industry, the size of the thermal,nuclear power plants is also expanding. Power plant cooling water contains largeamounts of waste heat, will give an adverse environmental impact. How to coordinatethe relationship between the cooling water discharge and water environmentprotection is the problem to be solved in the research, planning and construction ofpower plant. Therefore, the prediction of the cooling water into the flow field andtemperature field distribution in the receiving water and the cooling capacity of theforecasting water are of great significance.To reduce the environment water temperature rise due to thermal discharge, aneffective way is to take a deep drainage measures to enhance the mixing between thepower plant drainage and environmental water, which the value and range ofinfluence on the water surface temperature can be limited. Subject to the ChinaInstitute of Water Resources and Hydropower Research Special Fund "Thermal,nuclear power plant cooling water sports simulation test and improve"(ID:HR200704002) funding, this paper adopts the method of numerical simulation, theresearch in-depth on the bottom of the lateral thermal discharge stream is conducted.The main topics of the paper are as follows:(1) The author reviewed the basic theories and research methods on jet,summarized the current status quo topics of jet at home and abroad, and brieflyintroduced to the turbulent jet mathematical models and numerical methods. Based onthe existing research results in the field, the practical ideas and approaches suitable forthe study of this project have been developed.(2) To study the environment impact of the hydrodynamic discharge flow out ofthe aperture at lateral bottom of the single-hole mixing, the Reynolds stress model hasbeen adopted with taking the buoyancy affects into consideration, the genericequations are discredited by the finite-volume methods, and pressure term in thediscrete equations with grid SIMPLE algorithm correction coupled with the speed byselecting the appropriate turbulence parameters and wall parameters. The series ofnumerical simulation of flow for different operating conditions have been carried out.(3) In this paper, the flow field and temperature field distributions have beenpresented to the different conditions of velocity ratio, temperature discharge flow tomain flow, based on buoyant jet flow field and temperature field of the buoyant jettrajectory. The results show the attenuation law of temperature and velocity along with the axis and the buoyancy impacted on the jet trajectory. The analysis of differentflow velocity distribution under the conditions of the temperature rise characteristicshas been carried out further. Some valuable rules and conclusions on the buoyant jethave been obtained.The study reached the intended purpose. The achieved results are of importantreference value to the thermal, the nuclear power plant cooling water and low-levelwaste modeling and forecasting, and provide some information which iscomprehensive and reliable basis for the development of more appropriatethree-dimensional mathematical model in the future. Although the study is on theemission of thermal discharge, the results and approaches of the research can bereferenced to other areas of similar positive buoyancy to estimate the flow mixing.