Analysis and optimization of hot air return in excavator cooling system
In view of the high temperature torque limiting problem of an excavator un-der market conditions,an in plant heat balance test was conducted.The test fuel con-sumption percentage and torque percentage are the same as those in the market,with con-sistency and reproducibility.Considering the problem of hot air backflow caused by the cracking of the heat insulation sealing plate,the test plan is designed to remove the heat insulation sealing plate,install the heat insulation sealing plate and add heat insulation cotton.In Scheme I,the temperature difference between the inlet air of water dispersion and oil dispersion and the environment is 8.8℃and 9.7℃respectively,which is greater than the limit value of 5℃,which is consistent with the market test results.After TRN-SYS simulation verification,the problem of high temperature torsion limit in the market is characterized as that the heat balance exceeds the standard due to hot air reflux.Al-though Scheme Ⅱ and Scheme Ⅲ have been improved,the heat balance is still not up to standard.The hot air return is optimized by replacing the 7-blade fan and increasing the cooling area of the engine room to 0.32 m2.The excessive temperature is reduced to 0.4℃and 0.5℃,the heat balance is up to standard,and the wind speed and noise are also im-proved accordingly.The problem of high temperature torque limitation has been funda-mentally solved.
torsion limit at high temperatureheat balancehot air returntestTRNSYS
NETL
NSTL
万方数据
