A Study of Adiabatic and Diabatic Flow Boiling in Parallel Microchannels and Fractal-like Branching Microchannels

A Study of Adiabatic and Diabatic Flow Boiling in Parallel Microchannels and Fractal-like Branching Microchannels

4.11 - 1251 ratings - Source



A one-dimensional numerical model has been developed to study diabatic and adiabatic flow boiling in microchannels. This model accounts for developing flow effects and variable property effects. The model uses correlations for void fraction and two-phase multipliers found in the literature. The model has been used to study the performance differences between diabatic flow in single-phase and two-phase flow in fractal-like branching channels. It has also been used to examine the performance differences between diabatic two-phase flow boiling in these same fractal-like branching channels and straight parallel channels with identical wall surface areas. The model also was used to study pressure drop and exit quality differences for adiabatic two-phase flow boiling between fractal-like branching channels, with different geometries than the diabatic cases, and parallel channels again with identical wall surface areas. Results from experiments examining flow boiling in fractal-like branching channels are also reported. These results include channel pressure drop and void fraction for mass flow rates ranging from 100 to 225 g/min and inlet subcooling levels of 0 to 5AdC. The fractal-like branching network studied had four branching levels, a length ratio of 0.7071, a channel width ratio of 0.7071, a channel height of 150 um, a total channel length of 18 mm and a terminal channel width of 100 microm. The channel pressure drops varied from 20 kPa to 90 kPa. These results were also compared to results from the 1-D model, and the model showed good agreement with the pressure drop results. The agreement with the void fraction results was not as good driven primarily by noise in the experimental measurement.The reservoir was a small capacity residential water heater with a 2 kW heating element (Rheem 81VD6S). The thermostat circuit on the water heater was bypassed due to maximum water temperature limitations of the circuit. A PID controlleranbsp;...


Title:A Study of Adiabatic and Diabatic Flow Boiling in Parallel Microchannels and Fractal-like Branching Microchannels
Author:
Publisher:ProQuest - 2008
ISBN-13:

You must register with us as either a Registered User before you can Download this Book. You'll be greeted by a simple sign-up page.

Once you have finished the sign-up process, you will be redirected to your download Book page.

How it works:
  • 1. Register a free 1 month Trial Account.
  • 2. Download as many books as you like (Personal use)
  • 3. Cancel the membership at any time if not satisfied.


Click button below to register and download Ebook
Privacy Policy | Contact | DMCA