Geometrical optimization of bare tube heat exchangers for process industries

Author(s):  
T. Q. Ma ◽  
K. T. Ooi ◽  
T. N. Wong

This paper presents simulation results on the geometrical optimization design of bare tube heat exchangers. By linking a mathematical model with an optimization alogorithm, it is possible to predict which combination of five geometrical variables would produce a given coil capacity of a heat exchanger, the minimum core volume size operating at the minimum pressure drop. A constrained multivariable direct search technique is used in which the five geometrical variables and a mixture of five explicit and implicit constraints are accommodated. Using this design method, three typical sizes of bare tube optimization cases have been studied. The simulation results predict significant performance improvements for heat exchanger design. The range of tube outer diameter in this optimization study is from 4.9 to 9.0 mm.

2012 ◽  
Vol 629 ◽  
pp. 699-703
Author(s):  
Chun Sheng Guo ◽  
Wen Jing Du ◽  
Lin Cheng

The entransy loss minimization approach for the heat exchanger optimization design was established by Guo Z Y; the study based Guo Z Y’s works, found relationship between the entransy loss uniformity and the heat exchanger performance and the expression of the local entransy loss rate for heat convection was derived, numerical results of the heat transfer in a chevron plate heat exchanger and helix baffle heat exchanger show that the larger entransy loss uniformity factor appear in about Re=2000 and the entransy loss uniformity factor of chevron plate heat exchanges higher than helix baffle one.


2012 ◽  
Vol 490-495 ◽  
pp. 2381-2385
Author(s):  
Bao Lan Xiao ◽  
Wei Ming Wu ◽  
Xiao Li Yu ◽  
Guo Dong Lu

The excellent thermal-hydraulic performances of oil cooler are the strong guaranty for automotives’ normal operation. In this study, the thermal-hydraulic performances of compact oil cooler units with different fin size parameters are numerical simulated. According to simulation results, combined with neural networks method, the optimal fin size parameters are determined. Based on this, the effects of different fin arrange layouts on performances are also studied, and optimal layouts for different requirements for flow resistance and heat transfer performances are put forward. This optimal design method can play a guidance role for the designer and manufacturer of heat exchangers.


2020 ◽  
Vol 34 (14n16) ◽  
pp. 2040111
Author(s):  
Shu-Ling Tian ◽  
Ying-Ying Shen ◽  
Yao Li ◽  
Hai-Bo Wang ◽  
Sheryar Muhammad ◽  
...  

Plate-fin heat exchangers are widely used in industry at present due to their compact structure and high efficiency. However, there is a problem of flow maldistribution, resulting in poor performance of heat exchangers. The influence of the header configuration on fluid flow distribution is studied by using CFD software FLUENT. The numerical results show that the fluid flow inside the header is seriously uneven. The reliability of the numerical simulation is validated against the published results. They are found to be basically consistent within considerable error. The optimal number of the punch baffle is investigated. Various header configuration with different opening ratios have been studied under the same boundary conditions. The gross flow maldistribution parameter (S) is used to evaluate flow nonuniformity, and the flow maldistribution parameters of different schemes under different Reynolds numbers are listed and compared. The optimal header with minimum flow maldistribution parameter is obtained through the performance analysis of headers. It is found that the flow maldistribution of the improved header is significantly smaller compared with the conventional header. Hence, the efficiency of the heat exchanger is effectively enhanced. The conclusion provides a reference for the optimization design of plate-fin heat exchanger.


2019 ◽  
Vol 27 (01) ◽  
pp. 1950008 ◽  
Author(s):  
B. G. Prashantha ◽  
S. Seetharamu ◽  
G. S. V. L. Narasimham ◽  
M. R. Praveen Kumar

In this paper, the design of 50 W thermoacoustic refrigerators operating with air as working substance at 10 bar pressure and 3% drive ratio for a temperature difference of 28 K is described. The design strategies discussed in this paper help in design and development of low cost thermoacoustic coolers compared to helium as the working substance. The design and optimization of spiral stack and heat exchangers, and the promising 0.2[Formula: see text] and 0.15[Formula: see text] resonator design with taper and divergent section with hemispherical end are discussed. The surface area, volume, length and power density of the hemispherical end design with air as working substance is found better compared to the published 10 and 50 W coolers using helium as the working substance. The theoretical design results are validated using DeltaEC software simulation results. The DeltaEC predicts 51.4% improvement in COP (1.273) at the cold heat exchanger temperature of [Formula: see text]C with air as working substance for the 50[Formula: see text]W 0.15[Formula: see text]TDH resonator design compared to the published 50[Formula: see text]W 0.25[Formula: see text]TDH resonator design with helium as working substance.


2014 ◽  
Vol 686 ◽  
pp. 529-534
Author(s):  
Jian Xin Xie ◽  
Xiao Le Wang ◽  
Chao Liu

In this study, the engine suspension system was optimized for making the vibration between engine and car body minimized, and also the optimization was simulated using software Adams. The purpose of this study was to research the vibration isolation of the engine mounting system and implement multi-objective optimization for the intrinsic frequency. In this paper, the optimization was implemented in two ways: (1) the intrinsic frequency was optimized by reasonably allocating it: (2) the intrinsic frequency was optimized using energy decoupling. The optimized intrinsic frequencies were simulated using software Adams and then the simulation results were compared. The simulation results showed that the optimized energy distribution was almost up to 90% and the decoupling degree was greatly improved by comparing the initial data, proving the optimized data played a greater effect on engine vibration isolation and further verifying the feasibility of optimization design method.


Author(s):  
Piyush Sabharwall ◽  
Denis E. Clark ◽  
Ronald E. Mizia ◽  
Michael V. Glazoff ◽  
Michael G. McKellar

The goal of next generation reactors is to increase energy efficiency in the production of electricity and provide high-temperature heat for industrial processes. The efficient transfer of energy for industrial applications depends on the ability to incorporate effective heat exchangers between the nuclear heat transport system and the industrial process. The need for efficiency, compactness, and safety challenge the boundaries of existing heat exchanger technology. Various studies have been performed in attempts to update the secondary heat exchanger that is downstream of the primary heat exchanger, mostly because its performance is strongly tied to the ability to employ more efficient industrial processes. Modern compact heat exchangers can provide high compactness, a measure of the ratio of surface area-to-volume of a heat exchange. The microchannel heat exchanger studied here is a plate-type, robust heat exchanger that combines compactness, low pressure drop, high effectiveness, and the ability to operate with a very large pressure differential between hot and cold sides. The plates are etched and thereafter joined by diffusion welding, resulting in extremely strong all-metal heat exchanger cores. After bonding, any number of core blocks can be welded together to provide the required flow capacity. This study explores the microchannel heat exchanger and draws conclusions about diffusion welding/bonding for joining heat exchanger plates, with both experimental and computational modeling, along with existing challenges and gaps. Also, presented is a thermal design method for determining overall design specifications for a microchannel printed circuit heat exchanger for both supercritical (24 MPa) and subcritical (17 MPa) Rankine power cycles.


2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Yifei Wu ◽  
Wei Jia

AbstractPrecooled engine is a highly expected solution to achieve supersonic transport. As the crucial component, heat exchangers protect other components from ultrahigh temperature. In traditional design methods, the nominal result is multiplied by a safety factor, whose selection entirely depends on experience, ensuring sufficient working margin to cope with fluctuation of parameters. For aero-engine, heat exchangers must work reliably with minimum weight. An advanced method of thermal optimization design with parameters’ fluctuation is proposed and proved to be effective by experimental verification. The heat transfer area can be quantitatively linked with the design confidence level, considering the coupling effect of various parameters’ fluctuation. The probability density distribution of heat transfer area has the characteristic of positive skewness distribution. With the increase of design confidence, the required heat transfer area is growing faster and faster. After optimization, the design of heat exchanger meets the requirements and the weight is effectively controlled.


Author(s):  
Serhii Pyskunov ◽  
Serhii Trubachev ◽  
Oleksandr Baranyuk

Based on the results of the study of the parameters of the air flow inside of the brass screw-shape tube of the heat exchanger, the determination of their optimal geometric characteristics and further modeling of the stress-strain state was performed. Verification of simulation results is carried out on the basis of comparison with the test task.


2019 ◽  
Vol 114 ◽  
pp. 07001
Author(s):  
Tatyana Rafalskaya ◽  
Valery Rudyak

Heat exchangers used in various industries, most often work in conditions of variable flows and temperatures. At the same time, the existing theories of calculation of heat exchanger modes are based on the use of constant dimensionless parameters in any mode of operation. The purpose of this work is to obtain dependencies to determine the effect of coolant temperatures on the variable parameter of the heat exchanger. Using the simulation method, dependencies were found that describe the change in the heat exchanger parameter which made it possible to obtain a general formula for the change in the heat exchanger parameter at varying coolant temperatures. To test the applicability of the existing relations describing the change in the heat exchanger parameter and the formula obtained, a large number of heat exchangers were calculated in variable operating modes. Comparison with the simulation results showed that the ratios of the known theories of heat exchangers do not work in all modes and their application can lead to significant errors. A formula has been obtained allows one to find the effect of coolant temperatures on the variable parameter of the heat exchanger. The formula can be used to predict the modes of large systems.


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