Based on the experiment of onset of nucleate boiling(ONB)in natural circulation and the nonequilibrium thermodynamics dissipative theory,the mechanism of ONB in narrow rectangle channels of natural circulation is prop...Based on the experiment of onset of nucleate boiling(ONB)in natural circulation and the nonequilibrium thermodynamics dissipative theory,the mechanism of ONB in narrow rectangle channels of natural circulation is proposed.It points out that the onset of nucleate boiling is influenced by the degree of superheat and the special conditions of narrow channels.Under the conditions of both density difference in natural circulation and narrow rectangle channels,the prediction model of ONB in natural circulation of narrow channels based on fluctuating is established.The experimental results show that the present model can be used to predict the heat flux of ONB in narrow rectangle channels.Features of ONB in natural circulation narrow rectangle channels are as follows:heating power is the incentive of the happen of ONB;the higher the heating power is,the higher the degree of superheat is,and the earlier the ONB will appear.With the pressurizing,the appearance of ONB will be delayed.The higher the degree of supercooling is,the later the ONB appears.The ONB will happen easier when there are noncondensable gases and roughness in the channels.展开更多
为更好地开展自主化压水堆(pressurized water reactor,PWR)子通道分析软件传热模型的评价工作,对国家核安全局目前在审的几款国产自主化压水堆子通道分析软件的传热模型开展分析研究。首先,确认传热模型对于自主化压水堆子通道分析软...为更好地开展自主化压水堆(pressurized water reactor,PWR)子通道分析软件传热模型的评价工作,对国家核安全局目前在审的几款国产自主化压水堆子通道分析软件的传热模型开展分析研究。首先,确认传热模型对于自主化压水堆子通道分析软件的实际意义,即软件传热模型计算的相关参数主要体现在液相能量守恒方程的封闭过程中。然后通过对核态沸腾起始点(onset of nucleate boiling,ONB)模型的实验确认以及敏感性分析。最终得到ONB模型的计算偏差对通道内轴向压力、燃料包壳外壁面温度等参数的计算结果影响很小。虽然ONB模型的计算偏差会对通道内空泡份额以及偏离泡核沸腾比(departure from nucleate boiling ratio,DNBR)产生一定影响,但仅局限于ONB起始点附近位置,对后续高空泡份额、更小DNBR的通道轴向位置的参数计算影响很小。展开更多
Assume that D is a nuclear space and D' its strong topological dual space. Let {B_t}t∈(0,∞) be a Wiener D'-process. In this paper, the real-valued and D'-valued weak stochastic integral with respect to {...Assume that D is a nuclear space and D' its strong topological dual space. Let {B_t}t∈(0,∞) be a Wiener D'-process. In this paper, the real-valued and D'-valued weak stochastic integral with respect to {B_t} are established.AMS Subject Classification. 60H05.展开更多
基金Supported by National Natural Science Foundation of China(No.50976033)National Key Laboratory of Bubble Physics and Natural Circulation(No.9140C7 101030905)North China Electric Power University’s 211 Project
文摘Based on the experiment of onset of nucleate boiling(ONB)in natural circulation and the nonequilibrium thermodynamics dissipative theory,the mechanism of ONB in narrow rectangle channels of natural circulation is proposed.It points out that the onset of nucleate boiling is influenced by the degree of superheat and the special conditions of narrow channels.Under the conditions of both density difference in natural circulation and narrow rectangle channels,the prediction model of ONB in natural circulation of narrow channels based on fluctuating is established.The experimental results show that the present model can be used to predict the heat flux of ONB in narrow rectangle channels.Features of ONB in natural circulation narrow rectangle channels are as follows:heating power is the incentive of the happen of ONB;the higher the heating power is,the higher the degree of superheat is,and the earlier the ONB will appear.With the pressurizing,the appearance of ONB will be delayed.The higher the degree of supercooling is,the later the ONB appears.The ONB will happen easier when there are noncondensable gases and roughness in the channels.
文摘为更好地开展自主化压水堆(pressurized water reactor,PWR)子通道分析软件传热模型的评价工作,对国家核安全局目前在审的几款国产自主化压水堆子通道分析软件的传热模型开展分析研究。首先,确认传热模型对于自主化压水堆子通道分析软件的实际意义,即软件传热模型计算的相关参数主要体现在液相能量守恒方程的封闭过程中。然后通过对核态沸腾起始点(onset of nucleate boiling,ONB)模型的实验确认以及敏感性分析。最终得到ONB模型的计算偏差对通道内轴向压力、燃料包壳外壁面温度等参数的计算结果影响很小。虽然ONB模型的计算偏差会对通道内空泡份额以及偏离泡核沸腾比(departure from nucleate boiling ratio,DNBR)产生一定影响,但仅局限于ONB起始点附近位置,对后续高空泡份额、更小DNBR的通道轴向位置的参数计算影响很小。
文摘Assume that D is a nuclear space and D' its strong topological dual space. Let {B_t}t∈(0,∞) be a Wiener D'-process. In this paper, the real-valued and D'-valued weak stochastic integral with respect to {B_t} are established.AMS Subject Classification. 60H05.
