Vacuum Tube

الوصف

a) High Thermal Conductivity Heat conductivity of heat pipe is much higher than the common metal, from the above table, we can see that because inside the heat pipe it transfer heat by gas and liquid phase change heat, heat resistance is very small, so the axial heat conductivity is very high, while the radial heat conductivity is general. b) Good Isothermal performance when heat pipe is working, the working fluid temperature is the same, but it will absorb or release a lot heat, therefore, heat pipe can transfer much heat under isothermal circumstances theoretically, whose outside behavior is the isothermal performance of heat pipe is very ***** c) Reversibility of Heat Flow A heat pipe with wick, if only the capiliary force is enough, it will begin transfer heat, so that it make the temperature of two ends to equal. d) Thermodiode The heat pipe without wick like gravity-assisted heat pipe in solar water heater, in the absence of wick structure, the working fluid inside the pipe can just recycle by gravity, and the heat transferred from the bottom to the top and will not reverse so that get the heat lossed during night and winter. e) Thermal Switches Properity when the heat pipe temperature is lower than the freezing point of working fluid, heat pipe will stop working;when heat pipe temperature is higher than the critical temperature, the pipe is filled with steam, there is no phase change heat transfer process inside the pipe, heat pipe will stop working, therefore, the heat pipe working temperature is between the freezing point and critical point. f) Variability of Heat Flow Heat pipe can change the heat transfer area of the two ends independently, that is ing heat through smaller heating area but outputing heat by larger cooling area, or vice verse; by doing this to change the heat flow den.