在中压热工水力回路的喷放段上设计一定的破口面积,模拟小破口失水事故喷放进行了瞬态热工水力特性实验。本实验的工况参数范围为:压力 p=0.7～2.2MPa,过冷度△T_(sub)=50～120℃,质量流速 G=1750～2800kg/m~2·s,热流密度 q=0.3～1MW/m~2。通过实验,得出了系统压力、质量流速、壁温随喷放时间的变化关系曲线及系统压力、质量流速、初始过冷度、临界时间的相互影响关系曲线。 A certain breaking area was designed on the discharge section of the medium-pressure thermal hydraulic circuit, and the transient thermal-hydraulic characteristics experiment was simulated by simulating the small-breakage water-loss accident discharge. The experimental parameters range of working conditions: pressure p = 0.7 ~ 2.2MPa, subcooling △ T sub = 50 ~ 120 ℃, mass flow rate G = 1750 ~ 2800kg / m ~ 2 · s, heat flux density q = 0.3 ~ 1MW / m ~ 2. Through experiments, the relationship curves of system pressure, mass flow rate, wall temperature with discharge time and interaction between system pressure, mass flow rate, initial undercooling and critical time are obtained.