Research On The Key Technology Of Waist Tube Type Assembled Radiator

With the rapid development of automobile industry and the continuous improvement of cooling system heat dissipation performance,it is urgent to develop new heat transfer components to meet the heat dissipation needs of new automobiles.At present,a large number of studies have focused on the improvement of radiator performance in one aspect,but there are few studies on improving radiator performance from many aspects and angles.Prefabricated radiator because in the process of machining on the environment pollution-free,relative to the welding type radiator,more energy saving and environmental protection,can be widely used in some models,but the cooling efficiency low defect limits its use range.Therefore,to strengthen the research on the heat transfer performance of the assembled radiator is not only a response to the national policy of energy conservation and emission reduction,but also an important measure to enhance the competitiveness of enterprises and increase their profits.This study on the basis of flat tube type assembled radiator,starting from the main factors influencing the radiator cooling performance,from different angles to consider the radiator cooling performance boost,innovative design a new type waist type tube prefabricated radiator.The compared with the flat tube radiator,radiator has the characteristics of high efficiency,energy saving,environmental protection,in line with the current development trend of automobile industry,the research methods and research results in the future,the design of new type radiator,radiator cooling performance improvements,a single cooling components research and development has guiding significance and reference value.For prefabricated radiator cooling performance boost,this paper follow from the discharge pipe to the heat sink,to the discharge pipe and fin tube expanding exploration course,study of radiator core body responsible for heat dissipation and innovation.In the aspect of heat dissipation pipe,a new type of heat dissipation pipe with lumbar retraction structure,called lumbar retraction pipe,was innovatively proposed.Compared with flat pipe,the same diameter is smaller and the heat dissipation area is larger under the condition of the same cross-sectional area of flow in the same pipe.Fin aspects: change of the current existing cooperation manufacturer of louver fin structure parameters,blinds structure parameters under different target was optimized combination,design the match the collect waist tube heat dissipation performance high shutter fin.Radiator pipe and fin tube expanding aspects: changing the current fabricated car radiator general way of pushing expansion,innovation to new easily fabricated using the radiator bloated manner,improve the quality of the expanded joint,reduce the thermal resistance of the radiator,indirectly improve the cooling performance of radiator.In the whole process of research and innovation,and using methods of theoretical analysis,numerical simulation and wind tunnel test to study the discharge pipe,heat sinks,radiators,the overall flow heat transfer characteristics,reveals the new accept waist tube type assembled radiator to strengthen the cause of the heat transfer and easily meet the requirements of the expanded joint way;Under the change of multiple factors,the orthogonal test method was used to optimize the structure parameter combination of shutter fins.According to the test results,the formula of heat transfer and resistance performance with high precision of lump-type radiator was fitted by binomial linear regression method,which provided a basis for the prediction of heat transfer performance of radiator.The main contents are as follows:For different waist level of accept waist pipe and flat heat pipe tube and pipe outflow explorers carried on the simulation research,analyzes the type of the radiator pipe tube change to outside of tube and tube temperature field,velocity field,heat transfer enhancement performance parameters,comprehensive performance evaluation factor the influence of ascension.Studies have shown that under the same conditions,accept waist pipe tube and pipe outside of the inlet and outlet of the convective heat transfer coefficient and pressure drop were greater than the flat tube,the tube and comprehensive performance evaluation of enhanced boiling heat transfer outside tube improvement factor is greater than 1,prove the validity of the collect waist structure for enhancing heat transfer.In the study of waist collecting pipe,the comprehensive performance of no.3 waist collecting pipe with the largest waist collecting degree is the best,indicating that increasing waist collecting degree helps to improve the heat dissipation performance of the heat dissipation pipe.For in addition to the discharge pipe is different,other parameters are essentially the same 3 # waist tube radiator samples and flat tube radiator for numerical simulation of the analysis of two kinds of performance parameters of the radiator under the same conditions and the results showed that: 3 # collect waist tube radiator effect on heating of the air flow field is greater than the flat tube radiator,the convective heat transfer coefficient and pressure drop is higher than that of flat tube radiator,and the comprehensive heat transfer performance is better than that of flat tube radiator,which accords with the research results of discharge pipe.For new collect waist tube radiator and flat tube radiator for wind tunnel test,through experimental results of two kinds of radiator and the comparison of the results of numerical simulation,found that the test data and simulated data error is small,trend is consistent,the same conclusion,namely accept waist tube radiator manufacturers than existing flat tube radiator cooling performance is higher,the radiator of the wind tunnel test to prove the reliability of the numerical simulation and the correctness of the simulation model.In charge at the same time the waist tube radiator,on the basis of experimental results,the linear regression method is adopted,the fitting precision formula of heat transfer and resistance performance of the heat transfer performance of the new type radiator forecast provides the basis.Qualitatively studied with numerical simulation methods under the condition of single factor of louver fin window open the window Angle,fin spacing,fin spacing and fin thickness on the properties of the radiator cooling effect,the results show that,with the increase of Angle of window blinds the convective heat transfer coefficient of finned to rise,but the increase of heat transfer coefficient is very small,the pressure drop increase is very big,when the Angle of window is 27 °,comprehensive performance is best;As the fin spacing increases,the heat transfer coefficient and pressure drop both decrease.When the fin spacing is 1.2mm,the comprehensive performance is the best.,with the increase of fin spacing window under low wind speed,the louver fin heat transfer coefficient and pressure drop also will increase,but under the high wind speed,when the window shutter fin spacing Lp increases to a certain value,continue to increase the window fin spacing,decreases the convective heat transfer coefficient,pressure drop is reduced,when the window shutter fin spacing of 1.15 mm,comprehensive performance is best;As the fin thickness increases,the heat transfer coefficient of the shutter fin increases,and the pressure drop also increases slightly.When the fin thickness is 0.11 mm,the comprehensive performance is the best.Introduction of multi-factor orthogonal experiment method under the condition of louver fin structure parameters are optimized,build the L₉（3⁴）orthogonal test table,under the different optimization goal is best or optimal cooling fin of parameter combinations,the results for the design of the fin structure parameters and improvement has certain guiding role.Through the combination of numerical simulation and production practice,the deformation of the expanding rod of the waist-collecting tubular radiator is compared and studied.The results show that the closed tube radiator if use traditional prefabricated radiator way of pushing expansion,because waist tube small size of the waist,lead to push bilges bilge rod rigid when bad,product easy to instability,poor quality of expansion joint.When the method of expansion is adopted,the expansion force is small,the strength of the expansion bar meets the requirements,and the deformation of the expansion bar is small,which can well complete the expansion of the core body of the lumbar tubular assembly radiator.Therefore,according to the waist type radiator pipe structure characteristics and the expanding demand,pushing the traditional radiator expansion process,into a new expansion process,improve the quality of the expanded joint,reduce the thermal resistance of the radiator,indirectly improve the cooling performance of radiator.At the same time,the existing equipment is improved,and with the cooperation of manufacturers developed a fully automatic equipment for waist-tube-type radiator expansion.The research methods and results of this paper have higher reference value and practical significance for improving the heat dissipation performance of the assembled radiator from many aspects.