An experimental investigation was conducted to identify the heat transfer performanceof liquld flow boiling through microchanneled tubes. Compared with smooth tube, the flowboiling heat transfer in enhanced tubes is a...An experimental investigation was conducted to identify the heat transfer performanceof liquld flow boiling through microchanneled tubes. Compared with smooth tube, the flowboiling heat transfer in enhanced tubes is apparently intensified, and the wall superheat ofboiling initiation is significantly decreased. For the case of small flow rate, the boiling heattransfer coefficient of enhanced tube is 1.7 times higher than that of smooth tube.展开更多
Experiments were conducted to investigate flow boiling of subcooled water -methanol mixtures flowing through rectangular microchannels. The results show that the size of the microchannels and the flow velocity would a...Experiments were conducted to investigate flow boiling of subcooled water -methanol mixtures flowing through rectangular microchannels. The results show that the size of the microchannels and the flow velocity would affect the boiling initiation and the wall heat flux. Mixtures with a small concentration of methanol augmented the heat transfer, while those with larger concentration decreased the heat transfer, as compared with that of pure methonal. An optimum concentration exists for specified flow velocity.展开更多
The thermodynamic aspects of phase transformation of liquids in microchannels were analyzed to further understand the boiling characteristics, and a nondimensional parameter and related criteria that determine the pha...The thermodynamic aspects of phase transformation of liquids in microchannels were analyzed to further understand the boiling characteristics, and a nondimensional parameter and related criteria that determine the phase transition in microchannels were derived theoretically using classical phase stability theory. It was found that the size of the microchannels results in dramatically high heat fluxes for liquid nucleation when the microchannel is sufficiently small. This work provides theoretical substance for further investigating, especially quantitatively describing the heat and mass transfer process.展开更多
文摘An experimental investigation was conducted to identify the heat transfer performanceof liquld flow boiling through microchanneled tubes. Compared with smooth tube, the flowboiling heat transfer in enhanced tubes is apparently intensified, and the wall superheat ofboiling initiation is significantly decreased. For the case of small flow rate, the boiling heattransfer coefficient of enhanced tube is 1.7 times higher than that of smooth tube.
文摘Experiments were conducted to investigate flow boiling of subcooled water -methanol mixtures flowing through rectangular microchannels. The results show that the size of the microchannels and the flow velocity would affect the boiling initiation and the wall heat flux. Mixtures with a small concentration of methanol augmented the heat transfer, while those with larger concentration decreased the heat transfer, as compared with that of pure methonal. An optimum concentration exists for specified flow velocity.
文摘The thermodynamic aspects of phase transformation of liquids in microchannels were analyzed to further understand the boiling characteristics, and a nondimensional parameter and related criteria that determine the phase transition in microchannels were derived theoretically using classical phase stability theory. It was found that the size of the microchannels results in dramatically high heat fluxes for liquid nucleation when the microchannel is sufficiently small. This work provides theoretical substance for further investigating, especially quantitatively describing the heat and mass transfer process.
