自然循环汽化冷却系统水-水引射的行为

以Fluent 6.3为计算平台,采用数值模拟的方法对一种加热炉自然循环汽化冷却启动引射新技术——水-水引射的引射行为进行了系统研究,探讨了引射管管径、出入口直径比和喷射流量等参数对冷却回路循环流速和引射管附近冷却回路局部阻损系数的影响.研究结果表明,管内流场符合受限等温直流引射射流的一般规律.当引射管管径不变时,冷却回路中的循环流速随引射流量的增加而增大,随引射管出入口直径比的增大而减小;当引射流量及引射管出入口直径比不变时,冷却回路中的循环流速随着引射管管径的增大而减小.从引射效果和减小回路阻损的角度来看,缩口型引射管优于扩口型引射管.

Water-Water Ejecting Behavior in a Natural Circulation Evaporation Cooling System

The ejecting behavior of a new ejecting technique， named water-water ejecting technique， which is used to start up the natural circulation evaporation cooling system for a reheating furnace is numerically simulated with Fluent 6.3 software.The influences of ejecting tube diameter， diameter ratio of outlet to inlet and ejecting flowrate on circulating velocity and local resistance loss coefficient of the evaporation cooling circuit nearby ejecting tube are studied. The results indicated that the flow characteristics of water in the cooling circuit follows the general law of confined isothermal jet ejecting. The circulating velocity increases with the increasing of ejecting flowrate， but it decreases with the increasing of diameter ratio of outlet to inlet when the ejecting tube diameter is constant. At the same time， the circulating velocity decreases with the increasing of ejecting tube diameter when the ejecting flowrate and diameter ratio of outlet to inlet are both constant. The performance of necking-type ejecting tube is better than that of flared-type considering the ejecting performance and resistance loss.