Investigation on deicing process and influencing factors of pavement deicing salt based on heat and mass transfer theory
To solve the problem related to scientific and effective use of deicing salt in different environments,and reduce the road distress and environmental pollution caused by abuse of deicing salt,the mass balance equation and heat flux balance equation of road deicing salt in melting process were established base on mechanism of heat and mass transfer of road deicing salt.The temperature field model of road deicing salt melting was established by COMSOL finite element software by considering the influence of various factors such as phase transition process,wind speed,initial temperature and solar radiation.The variation rule of temperature field during ice melting was analyzed.The results show that the temperature of salt solution decreases rapidly at first and then rises slowly during the process of melting ice.During the period when the solid deicing salt is completely dissolved (stage Ⅰ),the temperature of salt solution decreases rapidly.After the deicing salt is completely dissolved (phase Ⅱ),the temperature of salt solution slowly rises.The higher external temperature increases the melting volume of deicing salt per unit mass,and the external temperature has greater influence on final temperature of salt solution than wind speed and the amount of deicing salt.The higher the wind speed,the shorter the time required for solid salt dissolution.The lower temperature of salt solution system after the end of stage Ⅰ makes the temperature of salt solution drop faster.As the increase of wind speed will accelerate the heat exchange between salt solution layer and external environment,the temperature rise of deicing salt deicing phase Ⅱ is obvious,and the average temperature of salt solution after dissolution is higher.The higher initial temperature of deicing salt can promote the dissolution of solid salt.At the same time,with the increase of initial reaction temperature,the end temperature of melting reaction also grows up.In addition,it is found that the influence of solar radiation on the process of deicing salt melting is not significant in stage Ⅰ,and the significant influence exhibits in stage Ⅱ.The research results can provide technical support and theoretical reference for the scientific and effective use of deicing salt in winter pavement.
deicing saltheat and mass transferpavement de-icingheat fluxCOMSOL
万方数据
维普
