Entropy generation during a phase-change process in a parallel plate channel

2009 ◽  
Vol 489 (1-2) ◽  
pp. 70-74 ◽  
Author(s):  
Mehmet F. Orhan ◽  
Aytunc Erek ◽  
Ibrahim Dincer
Keyword(s):  
Phase Change ◽  
Entropy Generation ◽  
Change Process ◽  
Parallel Plate ◽  
Phase Change Process ◽  
Plate Channel

scholarly journals Experimental research on hydrodynamic instabilities during condensation of the pro-ecological refrigerant R1234yf in tubular minichannels

2018 ◽  
Vol 70 ◽  
pp. 02010
Author(s):  
Waldemar Kuczyński ◽  
Aleksander Denis
Keyword(s):  
Experimental Data ◽  
Phase Change ◽  
Experimental Research ◽  
Change Process ◽  
Internal Diameter ◽  
Hydrodynamic Instabilities ◽  
Condensation Zone ◽  
Phase Change Process ◽  
Flow Condensation ◽  
Propagation Velocities

The following paper presents the results of preliminary experimental research on the influence of instabilities of a hydrodynamic type on the condensation phase change process in tubular minichannels. The research was focused on a new pro-ecological refrigerant, R1234yf, intended as a substitute for R134a that currently is being phased out. The flow condensation phase change process was investigated for both steady and un-steady conditions in singular tubular minichannels with an internal diameter d = {1,44; 2,30; 3,30} mm. The scope of the analysis of the experimental data covered an estimation of propagation velocities for both pressure and temperature instabilities as well as the shrinkage of the condensation zone. The results were also compared with the previous results obtained for the flow condensation phase change of R134a refrigerant in tubular minichannels with the same internal diameters.

Entropy Analysis of Mixed Convective Condensation by Evaluating Fan Velocity With a New Approach

2018 ◽  
Vol 10 (5) ◽  
Author(s):  
Dipanka Bhuyan ◽  
Asis Giri ◽  
Pradip Lingfa
Keyword(s):  
Entropy Generation ◽  
Parallel Plate ◽  
Numerical Study ◽  
Channel Length ◽  
Entropy Analysis ◽  
New Approach ◽  
Central Focus ◽  
Plate Channel ◽  
Convective Condensation ◽  
Velocity Channel

Present paper conducts an extensive numerical study on entropy analysis of mixed convective condensation inside a vertical parallel plate channel. A new approach is proposed to separate pump velocity component/Reynolds number from inlet mixed convection velocity. Influence of inlet governing parameters on condensation heat and mass transfer at different inlet pressure, velocity, channel length, and width are widely studied. The central focus of this paper is to study entropy generation under mixed convective condensation. Variation of local as well as overall entropy generation and second law efficiency for different geometric and environmental conditions are presented. For effective condenser design, present study provides two important correlations of overall volumetric entropy generation due to thermal transport and overall volumetric entropy generation due to mass transport.

Sign in / Sign up

Export Citation Format

Share Document