Internal Thermal Environment Simulation Of Construction Machinery

During the working process of construction machinery, the power losses of each part in its engine compartment spread into atmosphere in a way of convection and heat-exchanging, which makes the temperature in the compartment higher. If this temperature exceeds the parts in the compartment can bear, lots of bad effects will come out, even affect the function of the whole machine. Therefore, studying, predicting the thermal environment inside the engine compartment, and controlling the temperature within the parts' bearable limitation under normal working condition have great practical significances to the effective operation of construction machinery.A certain type of pipelayer is researched in this paper. During its electricity generating process, high temperature appeared in the engine compartment, which exceeds the maximum 60 degree centigrade it can endure, partial area can even reach to 80 degree centigrade. This makes some parts in the compartment, like fuel viscosity, hydraulic fuel viscosity, working resistance and other indexes of engine, hydraulic pump and electricity-generator change a lot and affect the function of each part. We use computational simulation method to study the internal thermal environment in order to confirm the distribution of temperature field and velocity field, analyze the factors which affect the thermal environment of engine compartment and reasons of high temperature, put forward the measures to lower the temperature in the compartment so that it can provide the advisory suggestion to the improvement of the engine compartment structure.CFD software-Fluent is used to simulate the thermal environment inside the engine compartment of this pipelayer while generating electricity. In the model, considered the air-flow is 3D steady-state turbulence and the fluid cannot be compressed, we define it by using Reynold Time-mean Equation and Double Equations Mathematics Model, which are most commonly used to solve the practical turbulence problem.;When doing computational simulation, by changing the location, size of the intakes and blowing direction of the cooling fan, totally three factors, to calculate eight different conditions and comparative analyze the results due to temperature field, velocity field and the distribution of mass flow rate, discussing the effect laws of the three factors to the internal thermal environment.The result shows that the effect of intakes' locations and blowing direction of fan to the internal thermal environment of engine compartment is much greater than that of the size of intakes. Open intakes in proper locations can make the temperature field distribute equally; change the blowing direction of the fan can increase the total air-flow greatly to accelerate the convection and heat-exchanging.In this model being studied, on the condition that the fan, water tank and other fittings are all done, given the location of the intake in the engine compartment, the current high temperature of partial areas can be solved, to make sure that the construction machinery is working normally and effectively.