The Analysis Of The ZL80 Wheel Loader Heat Exchanger

As the performance of the Wheel loader enhances, more and more heat isgenerated by the engine hydraulic system of the working set and trig system. Inorder to work normally, the loader must be cooled down by the radiator, middlecooler , oil cooler, hydraulic oil cooler and etc. Among those components, theradiator is the key part. Its efficiency and compact performance has always been theaim of researchers, that is, generates more heat flux in the same volume .Comparedwith other type of heat exchangers, the aluminous plate-fin heat exchanger is featureof its efficiency, compact, light and firm and low-cost., Which make it adapt to thebad working environment , large quantity of work and compact structure of thewhole machine.The paper mainly uses ANSYS FLOTRAN(CFD) to analyze the temperaturefield and the heat exchange of the aluminous plate-fin heat exchanger. By using theMultiple Species heat exchanger to simulate the process of the heat exchange betweenthe air and liquid, we could find the most important factor which affects the heatexchanger. And it will provide valuable reference for the plate-fin heat exchanger ofthe loader.During the analysis, it is very important to establish the boundary conditionbetween the two liquids. But it is also very difficult because it changes frequently asthe liquid flows along the channel. As a result, how to establish the conditionbecomes the key point of reflecting the real heat exchange. In this paper we use aspecial method to solve this problem. First, we modeling the structure of theplate-fine heat exchanger and then transmit it to ANSYS. Second, we modeling theliquid which flows along the channel in ANSYS. Thus we get a cooling cell groupwhich includes the liquid and plate-fin. By using ANSYS FLOTRAN(CFD) tocalculate the liquid filed of the model , the distribution of the liquid filed will beoutput. At last we put temperature condition on the liquid boundary, then we can geta true boundary condition between the liquid and the fin., under which we cancalculate the temperature field that fit it very well.By using this way we calculate the liquid filed in a part of the subchannel, weget the distribution of the flow of the liquid field and performance of the heatexchanger. We can get the conclusion by the result. The major reason which enhanceheat exchange of the plate-fin heat exchanger is the development and destroy of theflow boundary layer. The flow in the channel is three-dimensional flow but thevelocity which is plumb the clapboard is a tiny one, Flow boundary layer of theclapboard is not destroyed, the curve of the heat exchange along the clapboard doesnot jump. The whorl made some effect during the heat exchange. It is related to wayof the whorl wash out the wall around. On this paper we also simulate the wholeperformance of the plate-fin heat exchanger. We change the boundary condition suchas pressure and temperature. By doing these we want to make sure how these factorswork on the heat exchanger. We get some conclusion. The velocity in the entry of theheat exchanger changed greatly. Those parts are most important parts of the heatexchanger. Between the pressures lost arrange we want to decrease the pressure drop.It will slow down the flow, it will enhance the heat exchange. We should increase thepressure on the inlet of the air channel, It will enhance the heat exchange. The heatexchanger will adjust by itself. It can adapt the changing environment. But if theinlet temperature is too high, it is harm for the heat exchanger. So make sure the heatexchanger work in the normal condition.On the paper, we adopt the finite element method to analyze the heat exchanger.It can provide valuable reference for the plate-fin heat exchanger of the loader.