径向热流密度分布对并联多通道流动不稳定性的影响研究

以去离子水为工质，在系统压力为0.89~1.32 MPa、入口质量流速为500~750 kg/(m2?s)、入口温度58.5℃~132.3℃的参数范围内，研究了5根圆管[长1400 mm、外径Φ8 mm、壁厚2 mm（1400 mm×Φ8 mm× 2 mm）]加热通道内工质向上流动时，在不同径向热流密度分布条件下并联通道内发生流动不稳定时的特征，并对比了其流动不稳定边界。结果表明，在对热通道发生流动不稳定时的参数进行处理时，径向加热热流密度分布对并联多通道流动不稳定边界无明显影响；对于不同热流密度分布的并联多通道结构，其流动不稳定边界和完全对称加热的并联多通道的流动不稳定边界是一致的。 

Flow Instability in Parallel Narrow Rectangular Channel under Different Radial Heat Distribution

The flow instability in the parallel channels under different radial heat distribution was investigated in the following condition: the system pressure is 0.89~1.32 MPa, the mass flux is 500-750 kg/(m2·s) and the inlet temperature is 58.5℃~132.3℃ with the upflow deionized water. The test section consists of 5 parallel tube channels with the dimension of 1400 mm×Φ8 mm×2 mm. The characteristics of the flow instability in the parallel channels and the flow instability boundary was studied based on the experimental results. The results show that the distribution of the radial heating heat flux has no obvious effect on the unstable boundary of the parallel multi-channel flow, when dealing with the parameters of unsteady flow in the hot channel. For the parallel multi-channel structure with different heat flux distribution, the flow instability boundary is the same as that of the parallel multi-channel structure with complete symmetric heating.