|
Due to the high efficient and energy saving,plate-fin heat exchangers have been used widely,research and analysis of the main heat exchanger performance parameters and the optimal design are very important. In this paper,the study was focused on the plate-fin air to air heat exchanger which used simulated annealing algorithm to optimize the total number of entropy generation units under given space restriction,got the optimal parameters.Finally,compare the results with genetic algorithm,find the advantages and disadvantages of the simulated annealing algorithm.First, study the basis theories of plate-fin heat exchanger,and understand the design and heat transfer strengthen theory.Then choose the simulated annealing algorithm in this paper which is difficult to fall into the local minimum,simple to implement.SA does not require coding.Also study the principles of the algorithm,the algorithm process,the selection of parameters and the impact of parameters on the optimization results.Then analyse the reasons of the entropy generation which cansed by the limited temperature, the mixing flow and the flowing resistance,finally get the formula of the entropy generation of the plate-fin heat exchanger.Then,combine the example with the minimal entropy generation which is choosed as the objective function and use the software VC to compute the function,obtain the optimal sructural parameters of the plate-fin heat exchanger,compare the result of the economic cost,pressure drop and heat transfering area between SA and GA,SA is better.Finally,use the Second Law of Thermodynamics to analyse the optimized plate-fin heat exchanger such as Exergy analysis and improved Exergy analysis,then calculate the exergy efficiency of the heat system of the heat exchanger,to find that the exergy effciency of the plate-fin heat exchanger has been greatly improved.
|