去离子冷却水系统布水器的数值模拟及试验研究

Numerical simulation and experimental study on water diffuser of deionized cooling-water system

稳态强磁场实验装置(Steady High Magnetic Field Facilities,SHMFF)的运行需要10℃以下的去离子水带走磁体内的热负荷。通过优化蓄冷罐内的布水器类型和尺寸提高分层蓄冷效率,增加磁体装置的运行时间,在理论指导下以设计计算为基础选取5种径向型布水器,且采用数值模拟的方法研究了同一蓄冷罐内八角型和径向型布水器的斜温层厚度。定义布水效率的计算方法,并以布水效率为评价指标,分析了布水器的布水效果。研究表明:相同Re下径向型布水器的布水效果优于八角型,更易形成稳定的斜温层;相同出口流速型号为200-7.5径向型布水器的布水效率为89%;而型号为375-4的径向型布水器的布水效率为84.2%;径向型布水器的径高比是影响蓄冷罐内斜温层厚度的重要因素。研究成果可为蓄冷系统径向型布水器的优化设计提供指导依据。

The deionized water with the temperature below 10 ℃ is required to take away the thermal load inside of magnet during the operation of the Steady High Magnetic Field Facilities（ SHMFF）. Through the optimization of the type and dimension of the water diffuser inside of chilled-water storage tank for enhancing the stratified chilled-water storage efficiency and increasing the operation time of magnetic device,5 types of radial water diffusers are selected according to the design calculation under the guidance of the relevant theory,and then the thermocline thicknesses of the octagonal and radial water diffusers installed inside of the same chilled-water storage tank are studied with the method of numerical simulation. The method for calculating the water-diffusing efficiency is defined,while the diffusing effect of water diffuser is analyzed by taking the water-diffusing efficiency as the evaluation index. The study shows that the diffusing effect of the radial water diffuser is better than that of the octagonal one under the condition of the same Re,and then is more prone to create a stable thermocline. For the same outlet flowrate,the water diffusing efficiency of the radial water diffuser with the type of 200-7. 5 is 89%,while that of the radial water diffuser with the type of 375-4 is 84. 2%. Therefore,the ratio of height to diameter of the radial water diffuser is an important factor to influence the thickness of the thermocline inside of the chilled-water storage tank. The study result provides a guiding basis for the optimal design of the radial water diffuser for chilled-water storage system.