高压旁路阀流动传热特性

Flow and heat transfer in high-pressure bypass valve

为揭示高压旁路阀阀内流体流动传热机理,采用FLUENT软件中的多相流Euler模型数值模拟研究高压旁路阀内部的流动传热过程,然后运用热耦合技术将流场温度耦合到阀体以研究阀体温度分布。研究结果表明：在高压差下,阀内流场速度整体较快,平均流速为10~30 m/s,其中最大流速出现在蒸汽与减温水喷嘴混合处,流速高达80 m/s,阀内温度场总体呈现入口高、出口低的特点,蒸汽入口温度为870 K,出口平均温度为660 K,最低温度出现在拉伐尔喷管处,约为470 K。阀体外表面无保温层时阀体温差大,约为203 K。

Euler multiphase flow model from FLUENT programmer was employed to study the fluid flow and heat transfer mechanisms in high-pressure bypass valve. The temperature distribution of valve body was investigated by coupling flow field temperature to valve body using thermal coupling technology. The results show that the average velocity in the valve is as large as 10-30 m/s under high differential pressure. The maximum velocity with 80 m/s occurs at the position where steam and hot water nozzle are mixed. The temperature in valve shows a gradient distribution with high in inlet and low in outlet, in which the temperature of inlet and outlet are 870 K and 660 K, respectively. The Laval nozzle shows the lowest temperature of 470 K. The temperature difference（about 203 K） of valve body is large when there is no thermal insulation at the outer surface of valve.