MCHFR depends on CHF, the enthalpy and flow rate of the coolant, and the local heat flux at the critical location.CHF(critical heat flux),
MCHFR(minimum critical heat flux ratio)
how we will find the MCHFR for vs time for coast down transient by drawing channel operating channel and CHF setpoint curves for several time?
I really confused about this can you help me about it
I mean - what is the physical significance of CHF? In other words, what physically happens at the location when the heat flux of the cladding reaches CHF on a BWR fuel rod? This is fundamental knowledge for a fuel designer, fuel performance engineer and reactor operator.its iportant in the safety for heat transfer fro the cladding, its important for the design
Think about the difference in heat transfer coefficient between water and steam, and the significance of heat transfer coefficient, heat flux, and delta-T between coolant and cladding surface.its like a limit so we cant go beyond it to aviod heat trnsfer in the cladding, but i am asking something else
I would think that would be covered in the textbook that one is using.I have no idea about it at all thats why I asked <<<no information on the web and I dont have any supported material to read
Two things happen with decreasing mass flow: 1) the same portion of coolant (differential volume) picks up more heat, thus at a given axial elevation (downstream location), the specific enthalpy is greater (i.e. it's hotter if liquid, or it has higher quality if two phase), and 2) the heat transfer decreases, which means at a given location, delta-T is greater, which means the cladding temperature is greater.unfortunatly I dont have these book, I have the diagram only but i dont have explantion for it just slide, but thanx its very good inforation i understand to it, but what about as i said flow coastdown , i think in this case the mass flow rate will decrease resulting decrease in the heat flux and we will have big gap margin between it, is true what i said, because i have to show as it asked me find MCHF versus time?