Optimal Thermal Design of Fin-and-Tube Heat Exchangers by Integration of a SUMT and a SCGM

2016 ◽  
Author(s):  
Xinyi Li ◽  
Ting Ma ◽  
Qiuwang Wang
Keyword(s):  
Heat Exchangers ◽  
Optimization Technique ◽  
Unconstrained Minimization ◽  
Geometric Parameters ◽  
Thermal Design ◽  
Trial And Error ◽  
Heat Transfer Area ◽  
Compact Heat Exchangers ◽  
Minimization Technique ◽  
Combined Structure

It is a recognized hard task for the traditional thermal design of compact heat exchangers to obtain the optimal geometric parameters efficiently and effectively, owing to its complex trial-and-error process. In response to this issue, a simplified conjugate-gradient method (SCGM) combined with a sequential unconstrained minimization technique (SUMT) as a favorable optimization technique is incorporated with the traditional thermal design in this study, and then the key geometric parameters of fin-and-tube heat exchangers (FTHEs) are investigated and optimized successfully. In this method, the minimum total weight of FTHEs as the final objective is discussed, involving two geometric parameters, diameter of tube and height of shape as search variables. Aiming to minimize the objective function, SCGM is introduced to the SUMT to update the search variables continually with the fixed search steps and the search directions. Meanwhile, with the known geometric parameters from the SUMT, the log-mean temperature difference method (LMTD) is applied to determine the heat transfer area under the combined structure sizes for a given heat duty. Additionally, optimization results for three different heat duty is discussed in this work. The results show that it is effective to obtain the optimal sets of geometric parameters of FTHEs by the present method, and there are some guidance values for the thermal designs of compact heat exchangers.

scholarly journals Numerical Investigation on the Optimum Thermal Design of the Shape and Geometric Parameters of Microchannel Heat Exchangers with Cavities

Micromachines ◽  
2020 ◽  
Vol 11 (8) ◽  
pp. 721
Author(s):  
Haiwang Li ◽  
Yujia Li ◽  
Binghuan Huang ◽  
Tiantong Xu
Keyword(s):  
Heat Transfer ◽  
Thermal Performance ◽  
Heat Exchangers ◽  
Flow Resistance ◽  
Stokes Equations ◽  
Geometric Parameters ◽  
Thermal Design ◽  
Low Flow ◽  
High Heat Transfer ◽  
The Impact

Due to the large surface-area-to-volume ratio, microchannel heat exchangers have a higher heat transfer rate compared with traditional scale heat exchangers. In this study, the optimum microchannel cavity with high heat transfer and low flow resistance is designed to further improve microchannel exchangers’ thermal performance. A three-dimensional laminar flow model, consisting of Navier–Stokes equations and an energy conservation equation is solved and the conjugate heat transfer between the silicon basement and deionized water is taken into consideration. The impact of the shape, aspect ratio, size and spacing of the cavity on the thermal performance of microchannel exchangers are numerically investigated, respectively. The results indicated that the cavity on the sidewall can enhance heat transfer and reduce flow resistance simultaneously, and cavities with a relatively small expansion angle and streamlined edge could enhance thermal performance the most. Based on the conclusions, a new cavity shape is proposed, and the simulation results verify its excellent thermal performance as expected. Furthermore, investigation is performed to figure out the optimum design of the new cavity and the optimal geometric parameters of the cavity under different flow conditions have been obtained in principle for microchannel exchangers’ design.

scholarly journals Modeling and Optimization of Potable Water Network

2000 ◽  
Author(s):  
Berge Djebedjian ◽  
Ahmed Herrick ◽  
Magdy Abou Rayan
Keyword(s):  
System Design ◽  
Distribution System ◽  
Water Distribution ◽  
Potable Water ◽  
Water Distribution System ◽  
Optimization Technique ◽  
Unconstrained Minimization ◽  
Pipe Diameter ◽  
Water Network ◽  
Minimization Technique

A potable water network hydraulic analysis is presented in this paper. A mathematical model was developed, the model treats looped network. A computer program is developed in order to facilitate water distribution system design, which satisfies all constraints including pipe diameter and nodal pressure. An optimization technique is developed in order to evaluate the optimum network configuration and cost, the parameters are pipe diameter, flow rate, corresponding pressure and hydraulic losses. A non-linear technique was adopted in the solution. The model uses the sequential unconstrained minimization technique (SUMT) of Fiacco and McCormick (1964) to solve the optimal design of network. The adopted optimization technique decreases the required number of design iterations which for example may reach 1.48 billion iterations for a network with 8 pipes and a set of 14 available commercial pipes. The initially assumed pipe diameters are successively adjusted to suit the existing standard commercial pipe diameters. The technique was applied on a simple case study of gravity-fed network. The objective of the present investigation is to present a practical tool to help in the optimization of water distribution system, design and operation.

Thermal Design of Heat Exchanger With Fins Inside and Outside Tubes

2006 ◽  
Author(s):  
G. N. Xie ◽  
Q. Y. Chen ◽  
M. Zeng ◽  
Q. W. Wang
Keyword(s):  
Heat Transfer ◽  
Heat Exchanger ◽  
Pressure Drop ◽  
Heat Exchangers ◽  
Total Pressure ◽  
Thermal Design ◽  
Operating Pressure ◽  
Heat Transfer Area ◽  
Tube Heat Exchanger ◽  
Total Pressure Drop

Compact heat exchangers such as tube-fin types and plate-fin types are widely used for gas-liquid or gas-gas applications. Some examples are air-coolers, fan coils, regenerators and recuperators in micro-turbines. In this study, thermal design of fin-and-tube (tube-fin) heat exchanger performance with fins being employed outside and inside tubes was presented, with which designed plate-fin heat exchanger was compared. These designs were performed under identical mass flow rate, inlet temperature and operating pressure on each side for recuperator in 100kW microturbine as well as specified allowable fractions of total pressure drop by means of Log-Mean Temperature Difference (LMTD) method. Heat transfer areas, volumes and weights of designed heat exchangers were evaluated. It is shown that, under identical heat duty, fin-and-tube heat exchanger requires 1.8 times larger heat transfer area outside tubes and volume, 0.6 times smaller heat transfer area inside tubes than plate-fin heat exchanger. Under identical total pressure drop, fin-and-tube heat exchanger requires about 5 times larger volume and heat transfer area in gas-side, 1.6 times larger heat transfer area in air-side than plate-fin heat exchanger. Total weight of fin-and-tube heat exchanger is about 2.7 times higher than plate-fin heat exchanger, however, the heat transfer rate of fin-and-tube heat exchanger is about 1.4 times larger than that of plate-fin heat exchanger. It is indicated that, both-sides finned tube heat exchanger may be used in engineering application where the total pressure drop is severe to a small fraction and the operating pressure is high, and may be adopted for recuperator in microturbine.

scholarly journals Simulated annealing technique to design minimum cost exchanger

2011 ◽  
Vol 17 (4) ◽  
pp. 409-427 ◽  
Author(s):  
Nadeem Khalfe ◽  
Kumar Lahiri ◽  
Kumar Wadhwa
Keyword(s):  
Simulated Annealing ◽  
Heat Exchangers ◽  
Cost Minimization ◽  
Optimization Technique ◽  
Optimization Procedure ◽  
Minimum Cost ◽  
Geometric Parameters ◽  
Tube Length ◽  
Total Annual Cost ◽  
Economic Point

Owing to the wide utilization of heat exchangers in industrial processes, their cost minimization is an important target for both designers and users. Traditional design approaches are based on iterative procedures which gradually change the design and geometric parameters to satisfy a given heat duty and constraints. Although well proven, this kind of approach is time consuming and may not lead to cost effective design as no cost criteria are explicitly accounted for. The present study explores the use of nontraditional optimization technique: called simulated annealing (SA), for design optimization of shell and tube heat exchangers from economic point of view. The optimization procedure involves the selection of the major geometric parameters such as tube diameters, tube length, baffle spacing, number of tube passes, tube layout, type of head, baffle cut etc and minimization of total annual cost is considered as design target. The presented simulated annealing technique is simple in concept, few in parameters and easy for implementations. Furthermore, the SA algorithm explores the good quality solutions quickly, giving the designer more degrees of freedom in the final choice with respect to traditional methods. The methodology takes into account the geometric and operational constraints typically recommended by design codes. Three different case studies are presented to demonstrate the effectiveness and accuracy of proposed algorithm. The SA approach is able to reduce the total cost of heat exchanger as compare to cost obtained by previously reported GA approach.

A swarm intelligent approach for multi-objective optimization of compact heat exchangers

2016 ◽  
Vol 231 (2) ◽  
pp. 164-171 ◽  
Author(s):  
Milad Yousefi ◽  
Moslem Yousefi ◽  
Ricardo Poley Martins Ferreira ◽  
Amer Nordin Darus
Keyword(s):  
Heat Exchangers ◽  
Constraint Handling ◽  
Trial And Error ◽  
Compact Heat Exchangers ◽  
Multi Objective ◽  
Ranking Strategy ◽  
Intelligent Approach ◽  
User Friendly ◽  
Complicated Task

Design optimization of heat exchangers is a very complicated task that has been traditionally carried out based on a trial-and-error procedure. To overcome the difficulties of the conventional design approaches especially when a large number of variables, constraints and objectives are involved, a new method based on a well-established evolutionary algorithm, particle swarm optimization, weighted sum approach and a novel constraint handling strategy is presented in this study. Since the conventional constraint handling strategies are not effective and easy-to-implement in multi-objective algorithms, a novel feasibility-based ranking strategy is introduced which is both extremely user-friendly and effective. A case study from industry has been investigated to illustrate the performance of the presented approach. The results show that the proposed algorithm can find the near pareto-optimal with higher accuracy when it is compared to conventional non-dominated sorting genetic algorithm II. Moreover, the difficulties of a trial-and-error process for setting the penalty parameters are solved in this algorithm.

Particle swarm optimization technique for the optimal design of shell and tube heat exchangers

2012 ◽  
Vol 7 (1) ◽  
Author(s):  
Sandip Kumar Lahiri ◽  
Nadeem Muhammed Khalfe ◽  
Shiv Kumar Wadhwa
Keyword(s):  
Heat Exchanger ◽  
Heat Exchangers ◽  
Optimization Technique ◽  
Optimization Procedure ◽  
Geometric Parameters ◽  
Total Annual Cost ◽  
Swarm Optimization ◽  
Economic Point ◽  
Shell And Tube ◽  
Operational Constraints

Abstract Owing to the wide utilization of heat exchangers in industrial processes, their cost minimization is an important target for both designers and users. Traditional design approaches are based on iterative procedures which gradually change the design and geometric parameters until given heat duty and set of geometric and operational constraints are satisfied.Although well proven, this kind of approach is time consuming and may not lead to cost effective design. The present study explores the use of non-traditional optimization technique: calledParticle swarm optimization (PSO), for design optimization of shell and tube heat exchangers from economic point of view. The optimization procedure involves the selection of the major geometric parameters such as tube diameters, tubelength, bafflespacing, number of tube passes, tubelayout, type of head, baffle cutetc and minimization of total annual cost is considered as design target. The presented PSO technique is conceptually simple, has only a few parameters and is easy to implement.Furthermore, the PSO algorithm explores the good quality solutions quickly, giving the designer more degrees of freedom in the final choice with respect to traditional methods. The methodology takes into account the geometric and operational constraints typically recommended by design codes. Three different case studies are presented to demonstrate the effectiveness and accuracy of proposed algorithm . The PSO method leads to a design of a heat exchanger with a reduced cost of heat exchanger as compare to cost obtained by previously reported GA approach.

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