HEAT TRANSFER IN TWO-PHASE FLOW OF REFRIGERANT 12 THROUGH HORIZONTAL TUBE

2019 ◽  
Author(s):  
Hideo Uchida ◽  
Susumu Yamaguchi
Keyword(s):  
Heat Transfer ◽  
Two Phase Flow ◽  
Horizontal Tube ◽  
Phase Flow ◽  
Two Phase

Experimental Investigation on Heat Transfer of CO2 Solid-Gas Two Phase Flow With Dry Ice Sublimation

2009 ◽  
Author(s):  
Xin-Rong Zhang ◽  
Hiroshi Yamaguchi
Keyword(s):  
Heat Transfer ◽  
Gas Flow ◽  
Two Phase Flow ◽  
Horizontal Tube ◽  
Tube Length ◽  
Phase Flow ◽  
Two Phase ◽  
Average Value ◽  
Pressure Fields ◽  
Phase Fluid

From the viewpoint of protecting the ozone layer and preventing global warming, there is now strong demand for science and technology based on ecologically safe ‘natural’ working fluids. A CO2 refrigeration method has been proposed and developed several years ago, using CO2 solid-gas two phase fluid as refrigerant. Heat transfer of the CO2 solid-gas two phase flow in a horizontal tube is important to design of such a refrigeration system. In the present paper, an experiment work is conducted to measure its heat transfer characteristics in the horizontal tube. The results show an average value 310 W/(m2-K) of heat convective coefficient is experimentally obtained, which is much higher than that of gas flow. In the sublimation area, the Nusselt number is observed to increase slowly along the tube length, the phenomena may be physically explained that the sublimation process changes the thermal boundary layer thickness; makes the flow turbulence stronger; or changes the flow and the pressure fields.

Experimental Investigation and Empirical Correlations of Heat Transfer in Different Regimes of Air–Water Two-Phase Flow in a Horizontal Tube

2016 ◽  
Vol 9 (2) ◽  
Author(s):  
S. A. Nada
Keyword(s):  
Heat Transfer ◽  
Experimental Investigation ◽  
Reynolds Number ◽  
Heat Transfer Coefficient ◽  
Flow Rate ◽  
Two Phase Flow ◽  
Horizontal Tube ◽  
Flow Regimes ◽  
Phase Flow ◽  
Two Phase

This article reports on the experimental investigation of heat transfer to cocurrent air–water two-phase flow in a horizontal tube. The idea is to enhance heat transfer to the coolant liquid by air injection. Experiments were conducted for different air water ratios in constant temperature heated tube. Visual identification of flow regimes was supplemented. The effects of the liquid and gas superficial velocities and the flow regimes on the heat transfer coefficients were investigated. The results showed that the heat transfer coefficient generally increases with the increase of the injected air flow rate, and the enhancement is more significant at low water flow rates. A maximum value of the two-phase heat transfer coefficient was observed at the transition to wavy-annular flow as the air superficial Reynolds number increases for a fixed water flow rate. It was noticed that the Nusselt number increased about three times due to the injection of air at low water Reynolds number. Correlations for heat transfer by air–water two-phase flow were deduced in dimensionless form for different flow regimes.

Effect of Bubble flow on Heat Transfer Characteristics in Gas-Liquid Two-Phase Flow in a Horizontal Tube Bundle

2020 ◽  
Vol 2020 (0) ◽  
pp. OS12-06
Author(s):  
Kyoya ARAKI ◽  
Hideki MURAKAWA ◽  
Katsumi SUGIMOTO ◽  
Hitoshi ASANO ◽  
Daisuke ITO ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Two Phase Flow ◽  
Tube Bundle ◽  
Horizontal Tube ◽  
Bubble Flow ◽  
Phase Flow ◽  
Heat Transfer Characteristics ◽  
Two Phase ◽  
Transfer Characteristics
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