Exergy Study of Fouling Factors in Heat Exchanger Networks

2009 ◽  
Vol 132 (1) ◽  
Author(s):  
Zunlong Jin ◽  
Qiwu Dong ◽  
Minshan Liu
Keyword(s):  
Heat Transfer ◽  
Heat Exchanger ◽  
Objective Function ◽  
Capital Cost ◽  
Numerical Results ◽  
Heat Transfer Area ◽  
Heat Exchanger Networks ◽  
Exergy Consumption ◽  
Exergoeconomic Analysis ◽  
Selection Of

Selection of fouling factors is somewhat arbitrary in heat exchanger networks (HENs) synthesis. Fouling factors were reconsidered in this article for heat exchanger networks design. An objective function based on exergoeconomic analysis was introduced to assess optimal less conservative fouling factors. The objective took account of exergy consumption expense and heat exchanger capital cost at the same time. The exergy consumption of heat transfer in HENs was calculated using subsection integral on balanced composite curves. The proposed method was applied to an industrial case. Numerical results indicated that the optimal less conservative fouling factors were 80% of the original values and the heat transfer area of the system saved 350 m2 compared with root design. So it is necessary to reconsider the values of fouling factors for HENs design and that exergoeconomic analysis is useful in determining the optimal less conservative fouling factors.

Numerical simulation of the effect of baffle cut and baffle spacing on shell side heat exchanger performance using CFD

2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Swanand Gaikwad ◽  
Ashish Parmar
Keyword(s):  
Heat Transfer ◽  
Heat Transfer Coefficient ◽  
Heat Exchanger ◽  
Pressure Drop ◽  
Transfer Coefficient ◽  
Numerical Results ◽  
Shell Side ◽  
Tube Heat Exchanger ◽  
Shell And Tube ◽  
Two Parameters

AbstractHeat exchangers possess a significant role in energy transmission and energy generation in most industries. In this work, a three-dimensional simulation has been carried out of a shell and tube heat exchanger (STHX) consisting of segmental baffles. The investigation involves using the commercial code of ANSYS CFX, which incorporates the modeling, meshing, and usage of the Finite Element Method to yield numerical results. Much work is available in the literature regarding the effect of baffle cut and baffle spacing as two different entities, but some uncertainty pertains when we discuss the combination of these two parameters. This study aims to find an appropriate mix of baffle cut and baffle spacing for the efficient functioning of a shell and tube heat exchanger. Two parameters are tested: the baffle cuts at 30, 35, 40% of the shell-inside diameter, and the baffle spacing’s to fit 6,8,10 baffles within the heat exchanger. The numerical results showed the role of the studied parameters on the shell side heat transfer coefficient and the pressure drop in the shell and tube heat exchanger. The investigation shows an increase in the shell side heat transfer coefficient of 13.13% when going from 6 to 8 baffle configuration and a 23.10% acclivity for the change of six baffles to 10, for a specific baffle cut. Evidence also shows a rise in the pressure drop with an increase in the baffle spacing from the ranges of 44–46.79%, which can be controlled by managing the baffle cut provided.

scholarly journals Numerical Study on Flow and Heat Transfer Mechanisms in the Heat Exchanger Channel with V-Orifice at Various Blockage Ratios, Gap Spacing Ratios, and Flow Directions

2019 ◽  
Vol 2019 ◽  
pp. 1-21 ◽  
Author(s):  
Amnart Boonloi ◽  
Withada Jedsadaratanachai
Keyword(s):  
Heat Transfer ◽  
Heat Exchanger ◽  
Numerical Study ◽  
Numerical Results ◽  
Blockage Ratio ◽  
Maximum Heat ◽  
Flow And Heat Transfer ◽  
Maximum Heat Transfer ◽  
Smooth Channel ◽  
Gap Spacing

Numerical assessments in the square channel heat exchanger installed with various parameters of V-orifices are presented. The V-orifice is installed in the heat exchanger channel with gap spacing between the upper-lower edges of the orifice and the channel wall. The purposes of the design are to reduce the pressure loss, increase the vortex strength, and increase the turbulent mixing of the flow. The influence of the blockage ratio and V-orifice arrangement is investigated. The blockage ratio, b/H, of the V-orifice is varied in the range 0.05–0.30. The V-tip of the V-orifice pointing downstream (V-downstream) is compared with the V-tip pointing upstream (V-upstream) by both flow and heat transfer. The numerical results are reported in terms of flow visualization and heat transfer pattern in the test section. The thermal performance assessments in terms of Nusselt number, friction factor, and thermal enhancement factor are also concluded. The numerical results reveal that the maximum heat transfer enhancement is found to be around 26.13 times higher than the smooth channel, while the optimum TEF is around 3.2. The suggested gap spacing for the present configuration of the V-orifice channel is around 5–10%.

Heat Transfer in Liquid-Coupled Indirect Heat Exchanger Systems

1975 ◽  
Vol 97 (4) ◽  
pp. 499-503 ◽  
Author(s):  
R. B. Holmberg
Keyword(s):  
Heat Transfer ◽  
Heat Exchanger ◽  
Flow Rate ◽  
Liquid Flow ◽  
Rate Ratio ◽  
Liquid Flow Rate ◽  
Coupled System ◽  
Heat Transfer Area ◽  
Cold Side ◽  
Total Heat Transfer

The theory of liquid-coupled indirect heat exchanger systems has been studied to ascertain optimum criteria with respect to the coupling-liquid flow rate and the distribution of total heat transfer area between the hot-side and cold-side exchanger units in the case of counterflow arrangement. The optimum coupling-liquid capacity rate is derived and given as a function of the over-all capacity rate ratio and the Ntu ratio between the two exchanger units. For this optimum liquid capacity rate together with the proposed over-all number of transfer units, it is shown that the over-all heat transfer effectiveness of the liquid-coupled system can be expressed in the ordinary form for individual exchanger units in true counterflow.

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