Influence of packed honeycomb ceramic on heat extraction rate of packed bed embedded heat exchanger and heat transfer modes in heat transfer process

2015 ◽  
Vol 65 ◽  
pp. 76-81 ◽  
Author(s):  
Zengli Gao ◽  
Yongqi Liu ◽  
Zhenqiang Gao
Keyword(s):  
Heat Transfer ◽  
Heat Exchanger ◽  
Transfer Process ◽  
Packed Bed ◽  
Heat Transfer Process ◽  
Extraction Rate ◽  
Heat Extraction ◽  
Honeycomb Ceramic ◽  
Heat Extraction Rate

scholarly journals CFD SIMULATION OF THE HEAT TRANSFER PROCESS IN A CHEVRON PLATE HEAT EXCHANGER USING THE SST TURBULENCE MODEL

2015 ◽  
Vol 55 (4) ◽  
pp. 267 ◽  
Author(s):  
Jan Skočilas ◽  
Ievgen Palaziuk
Keyword(s):  
Heat Transfer ◽  
Heat Exchanger ◽  
Transfer Process ◽  
Cfd Simulation ◽  
Numerical Study ◽  
Analytical Calculation ◽  
Heat Transfer Process ◽  
Plate Heat Exchanger ◽  
Hot Water ◽  
Plate Heat

<p>This paper deals with a computational fluid dynamics (CFD) simulation of the heat transfer process during turbulent hot water flow between two chevron plates in a plate heat exchanger. A three-dimensional model with the simplified geometry of two cross-corrugated channels provided by chevron plates, taking into account the inlet and outlet ports, has been designed for the numerical study. The numerical model was based on the shear-stress transport (SST) <em>k-!</em> model. The basic characteristics of the heat exchanger, as values of heat transfer coefficient and pressure drop, have been investigated. A comparative analysis of analytical calculation results, based on experimental data obtained from literature, and of the results obtained by numerical simulation, has been carried out. The coefficients and the exponents in the design equations for the considered plates have been arranged by using simulation results. The influence on the main flow parameters of the corrugation inclination angle relative to the flow direction has been taken into account. An analysis of the temperature distribution across the plates has been carried out, and it has shown the presence of zones with higher heat losses and low fluid flow intensity.</p>

Interplay of fluids mixing and heat transfer in a dual-loop ORC direct contact heat exchanger used for waste heat utilization

2020 ◽  
Vol 234 (11) ◽  
pp. 2294-2305
Author(s):  
Qingtai Xiao ◽  
Wen Luo ◽  
Junwei Huang ◽  
Jianxin Xu ◽  
Hua Wang
Keyword(s):  
Heat Transfer ◽  
Heat Exchanger ◽  
Transfer Process ◽  
Boiling Heat Transfer ◽  
Direct Contact ◽  
Heat Transfer Process ◽  
Mixing Process ◽  
Contact Heat ◽  
Mixing Index ◽  
Direct Contact Heat Exchanger

By bringing two immiscible fluids at different temperatures into a direct contact heat exchanger (DCHE), bubble swarms are produced in the dual-loop ORC direct contact boiling heat transfer process. The aim of this paper is to make effort to explore the interplay between mixing state quality and heat transfer performance of fluids in the DCHE. Through flow visualization of this mixing process, a simple image analysis technique is introduced to represent the formation and evolution of vapor around the injected coolant droplets. Description of the boiling heat transfer process is here achieved by average volumetric heat transfer coefficient (VHTC). Experimental results attest that the proposed mixing index is powerful and sufficient compared with the Betti numbers method for the mixing quality quantification of bubbles inside DCHE. The synergistic association between the fluids mixing process and the heat transfer process is investigated by statistical regression model of new mixing index and VHTC. The contributions, including the data from monitoring practice in ORC heat transfer system and the proposed way, are presented to delve into the transient behaviors comparison of various fluids mixing and heat transfer processes conveniently.

scholarly journals Experimental Investigation on Thermal Performance of Double-U-tube Heat Exchanger Using CuO/water Nanofluid as Heat Transfer Fluid

2020 ◽  
Vol 165 ◽  
pp. 01022
Author(s):  
Ruiqing Du ◽  
Dandan Jiang ◽  
Yong Wang
Keyword(s):  
Heat Transfer ◽  
Heat Exchanger ◽  
Thermal Performance ◽  
Transfer Process ◽  
Heat Transfer Process ◽  
Heat Transfer Fluid ◽  
Geothermal Heat ◽  
Tube Heat Exchanger ◽  
Heating And Cooling ◽  
Geothermal Heat Exchanger

By applying the shallow ground energy to supply building heating and cooling, the geothermal heat exchanger systems were considered as an energy-efficient building service system. In this study, the CuO/water nanofluid was employed as circuit fluids of the geothermal heat exchanger system, and the thermal performance of the heat exchanger was investigated. The results showed that the heat transfer process of CuO/water nanofluid became stable earlier than that water. Furthermore, the heat transfer rate of nanofluid was higher than that of water when the heat transfer process plateaued.

Intensification of the heat-transfer process in an air-cooled plate-ribbed heat exchanger

1986 ◽  
Vol 22 (12) ◽  
pp. 558-560
Author(s):  
Ya. A. Berman ◽  
V. G. Bulygin ◽  
E. R. Yakhenko
Keyword(s):  
Heat Transfer ◽  
Heat Exchanger ◽  
Transfer Process ◽  
Heat Transfer Process

THE ANALYSIS OF EXERGY EFFICIENCY IN THE LOW TEMPERATURE HEAT EXCHANGER

2007 ◽  
Vol 21 (18n19) ◽  
pp. 3497-3499 ◽  
Author(s):  
LAN PENG ◽  
YOU-RONG LI ◽  
SHUANG-YING WU ◽  
BO LAN
Keyword(s):  
Heat Transfer ◽  
Heat Capacity ◽  
Heat Exchanger ◽  
Low Temperature ◽  
Transfer Process ◽  
Heat Exchangers ◽  
Heat Transfer Process ◽  
Exergy Efficiency ◽  
Capacity Ratio ◽  
Temperature Heat

Based on the analyzing of the thermodynamic performance of the heat transfer process in the low temperature heat exchangers, the exergy efficiency of the heat transfer process is defined and a general expression for the exergy efficiency is derived, which can be used to discuss the effect of heat transfer units number and heat capacity ratio of fluids on the exergy efficiency of the low temperature heat exchanger. The variation of the exergy efficiency for several kinds of flow patterns in the low heat exchangers is compared and the calculating method of the optimal values of heat capacity ratio for the maximum exergy efficiency is given.

The effect of heat loss on the performance of a solar-driven heat engine

2009 ◽  
Vol 223 (7) ◽  
pp. 1615-1621
Author(s):  
O S Sogut ◽  
A Durmayaz
Keyword(s):  
Heat Transfer ◽  
Heat Exchanger ◽  
Heat Loss ◽  
Transfer Process ◽  
Rankine Cycle ◽  
Heat Transfer Process ◽  
Working Fluid ◽  
Fluid Temperature ◽  
Parabolic Trough ◽  
Thermal Reservoir

An optimal performance analysis of a parabolic-trough direct-steam-generation solar-driven Rankine cycle power plant at maximum power (MP) and under maximum power density (MPD) conditions is performed numerically to investigate the effects of heat loss from the heat source and working fluid. In this study, the ideal Rankine cycle of the solar-driven power plant is modified into an equivalent Carnot-like cycle with a finite-rate heat transfer. The main assumptions of this study include that: (a) the parabolic collector is the thermal reservoir at a high temperature, (b) the heat transfer process between the collector and the working fluid is through either radiation and convection simultaneously or radiation only, and (c) the heat transfer process from the working fluid to the low-temperature thermal reservoir is convection dominated. Comprehensive discussions on the effect of heat loss during the heat transfer process from the hot thermal reservoir to the working fluid in the parabolic-trough solar collector are provided. The major results of this study can be summarized as follows: (a) the working fluid temperature at the hot-side heat exchanger decreases remarkably whereas the working fluid temperature at the cold-side heat exchanger does not show any significant change with increasing heat loss, (b) the MP, MPD, and thermal efficiencies decrease with increasing heat loss, and (c) the effect of heat loss on the decrease of thermal efficiency increases when convection is the dominant heat transfer mode at the hot-side heat exchanger.

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