Heat transfer in ?oblique? flow of a fluid with Pr?1 over a single tube

1977 ◽  
Vol 32 (6) ◽  
pp. 626-628
Author(s):  
V. M. Borishanskii ◽  
M. A. Gotovskii ◽  
V. B. Zhinkina ◽  
L. V. Kozlova ◽  
E. G. Kosheleva ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Single Tube ◽  
Oblique Flow

Thermodynamic Analysis of the Internal Melt-Ice-on-Tube during Melting under Natural Convection

2014 ◽  
Vol 937 ◽  
pp. 375-380
Author(s):  
Yi Liu ◽  
Xin Chen
Keyword(s):  
Heat Transfer ◽  
Natural Convection ◽  
Storage System ◽  
Heat Transfer Process ◽  
The Other ◽  
Ice Storage ◽  
Ice Melting ◽  
Single Tube ◽  
Initial Stage ◽  
The One

The numerical simulation of the ice melting processes in internal melt-ice-on-tube which is applied widely in the ice storage system is carried out. The dynamic mathematical models about melting are established and solved by using enthalpy method. Natural convection of the melted water in the course of melting is studied, and natural convection influences on single tube in melting heat transfer process is analyzed under the related parameters. Several conclusions are obtained:1. Because of natural convection of the melted water, the curve of melting interface is no longer a circle, but a curve changing with angle. The melting radius reaches minimum at the bottom and maximum at the top.2. The one with natural convention is compared to the other not considered. At initial stage, the influence of natural convection is smaller in the course of melting. However, the influence of natural convention increases along with melting.

The effect of an electric field on boiling heat transfer of refrigerant-11-boiling on a single tube

1990 ◽  
Vol 26 (2) ◽  
pp. 359-365 ◽  
Author(s):  
H. Kawahira ◽  
Y. Kubo ◽  
T. Yokoyama ◽  
J. Ogata
Keyword(s):  
Heat Transfer ◽  
Electric Field ◽  
Boiling Heat Transfer ◽  
Single Tube

Validation Experiment for the Cooling Capability of Passive Auxiliary Feedwater System (PAFS) With PASCAL Facility

2012 ◽  
Author(s):  
Byoung-Uhn Bae ◽  
Seok Kim ◽  
Yu-Sun Park ◽  
Bok-Deuk Kim ◽  
Kyoung-Ho Kang ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Natural Convection ◽  
Heat Exchanger ◽  
System Analysis ◽  
Thermal Power ◽  
Heat Removal ◽  
Steady State Condition ◽  
Single Tube ◽  
Decay Heat ◽  
Validation Experiment

The Passive Auxiliary Feedwater System (PAFS) is one of the advanced safety features adopted in the APR+ (Advanced Power Reactor Plus) which is intended to completely replace the conventional active auxiliary feedwater system. It removes the decay heat by cooling down the secondary system of the SG using condensation heat exchanger installed in the Passive Condensation Cooling Tank (PCCT). With an aim of validating the cooling and operational performance of the PAFS, PASCAL (PAFS Condensing Heat Removal Assessment Loop), was constructed to experimentally investigate the condensation heat transfer and natural convection phenomena in the PAFS. It simulates a single tube of the passive condensation heat exchangers, a steam-supply line, a return-water line, and a PCCT with a reduced area, which is equivalent to 1/240 of the prototype according to a volumetric scaling methodology with a full height. The objective of the experiment is to investigate the cooling performance and natural circulation characteristics of the PAFS by simulating a steady state condition of the thermal power. From the experiment, two-phase flow phenomena in the horizontal heat exchanger and PCCT were investigated and the cooling capability of the condensation heat exchanger was validated. Test results showed that the design of the condensation heat exchanger in PAFS could satisfy the requirement for heat removal rate of 540 kW per a single tube and the prevention of water hammer phenomenon inside the tube. It also proved that the operation of PAFS played an important role in cooling down the decay heat by natural convection without any active system. The present experimental results will contribute to improve the model of the condensation and boiling heat transfer, and also to provide the benchmark data for validating the calculation performance of a thermal hydraulic system analysis code with respect to the PAFS.

Study on Heat Transfer Characteristics of Loop Heat Pipe for Solar Collector

2012 ◽  
Author(s):  
Shota Sato ◽  
Shigeki Hirasawa ◽  
Tsuyoshi Kawanami ◽  
Katsuaki Shirai
Keyword(s):  
Heat Transfer ◽  
Heat Pipe ◽  
Heat Transfer Rate ◽  
Solar Collector ◽  
Transfer Rate ◽  
Thermal Conductance ◽  
Filling Ratio ◽  
Working Fluid ◽  
Loop Heat Pipe ◽  
Single Tube

We experimentally study the thermal conductance of single-tube and loop heat pipes for a solar collector. The evaporator of the heat pipe is 1 m long, 6 mm in diameter and has 30° inclination. The thermal conductance is defined as the heat transfer rate divided by the temperature difference between the evaporator-wall and the condenser-wall. Effects of heat transfer rate, saturation temperature of the working fluid, liquid filling ratio, inclination angle, and position of the evaporator on the thermal conductance are examined. We found that the thermal conductance of the 30°-inclined loop heat pipe with an upper-evaporator is 40–50 (W/K), which is 1.8 times higher than that of the vertical loop type and 3 times higher than that of the single-tube type. Thus, the inclined loop heat pipe is preferable for a solar collector. There is an optimum liquid filling ratio. When the liquid filling ratio is too small, a dry-out portion appears in the evaporator. When the liquid filling ratio is too large, the liquid flows in the condenser to decrease heat transfer area. Also we numerically analyze the thermal conductance of a vertical loop heat pipe.

Second Law Based Optimization of Falling Film Single Tube Absorption Generator

2002 ◽  
Author(s):  
Saeid Jani ◽  
Mohamad H. Saidi ◽  
Ali Heydari ◽  
Ali A. Mozaffari
Keyword(s):  
Heat Transfer ◽  
Mass Transfer ◽  
Entropy Generation ◽  
Horizontal Tube ◽  
Heat Transfer Fluid ◽  
Falling Film ◽  
Efficient Design ◽  
Single Tube ◽  
Evaporation Heat ◽  
Dimensionless Correlations

The objective of this paper is to provide optimization of falling film Li/Br solution on a horizontal single tube based on minimization of entropy generation. Flow regime is considered to be laminar, the effect of boiling has been ignored and wall temperature is constant. Velocity, temperature and concentration distributions are numerically determined and dimensionless correlations are obtained for predicting the average heat transfer coefficient and average evaporation factor on the horizontal tube. Thermodynamic imperfection due to passing lithium bromide solution is attributed to non-isothermal heat transfer; fluid flow friction and mass transfer irreversibility. Scale analysis shows that the momentum and mass transfer irreversibilities can be ignored at the expense of heat transfer irreversibility. In the process of optimization, for a specified evaporation heat flux, the entropy generation along with the developed heat and mass transfer dimensionless correlations is minimized and the optimal geometry and the optimum thermal hydraulic parameters are revealed. The investigation cited here indicates the promise of entropy generation minimization as an efficient design and optimized tool.

Single Tube Heat Transfer in Aerated Vibrated Beds

Drying ’85 ◽  
1985 ◽  
pp. 186-194 ◽  
Author(s):  
Karun Malhotra ◽  
Arun S. Mujumdar
Keyword(s):  
Heat Transfer ◽  
Single Tube

CFD Studies on the Heat Transfer Characteristics of a Horizontal Single-Tube in Fluidized Bed Heat Exchanger

2011 ◽  
Vol 374-377 ◽  
pp. 183-186
Author(s):  
Cong Shen ◽  
Jian Xiang Guo ◽  
Lin Li ◽  
Jin Fei Sun
Keyword(s):  
Heat Transfer ◽  
Heat Exchanger ◽  
Fluidized Bed ◽  
High Performance ◽  
Fluid Model ◽  
Two Phase ◽  
Scaling Properties ◽  
Single Tube ◽  
Industrial Sectors ◽  
Two Fluid Model

The fluidized-bed heat exchanger is widely used in various industrial sectors with the high performance of its heat transfer, ability to adapt working conditions, anti-scaling properties and many other advantages. This paper takes a horizontal single-tube in fluidized-bed heat exchanger and the fluidized low-temperature smoke around the tube as the objects of study. Euler-Euler two-fluid model is taken in use. Heat transfer between gas-solid two-phase flows and water in single-tube is simulated. The temperature field and general heat transfer coefficient is analyzed by simulated graphics.

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