Analysis And Experiment Study On Heat Transfer In The Asphalt Pavement Heating Process

The asphalt pavement heating is a key procedure in the hot in-place recycling(HIR)process.HIR is an economic,efficient,quick and environmental asphalt pavement maintenance technology,which generally heats the asphalt pavement temperature to 100?,while the surface temperature is 180?.Else,the asphalt pavement aging and even coking when the surface temperature of pavement is too high,or the heating time is prolonged when the surface temperature of pavement is too low.Although the HIR technology has been widely used,the relationship between the heating power and the recycling temperature still needs to study in-depth.Analyzing the heat transfer characteristics in different heating procedure can solve the problem of recycling temperature control for achieving efficient energy-saving heating.This paper is based on the Project Study on heat transfer mechanism of infrared continuous heating process of Asphalt Pavement Based on spectral analysis supported by NSFC,Project Study on heat transfer mechanism of series heating methods for asphalt pavement geothermal regeneration supported by the Fundamental Research Funds for the Central Universities and the Project Development and industrialization of high efficiency environmental protection and intelligent regeneration units for Asphalt Pavement supported by the Jiangsu province enterprise innovation,combined with asphalt pavement structure,the principle of heat transfer and assumption,the heat transfer model is established and the heat transfer equation is deduced.According to the heat transfer equation and boundary condition,the main influence factors of heat transfer efficiency in heating process are analyzed.The heat transfer equation is solved,the finite difference program is written,and the reliability of the numerical simulation is verified by the simulation heating experiment.Based on the feasibility of numerical simulation,the heating and heat transfer process of traditional asphalt pavement heating technology is analyzed,and a continuous heating mode with variable power is put forward.Through numerical simulation analysis,the continuous variable power heating can make the asphalt pavement surface reaches the set temperature and remained constant during the construction process of the heating power machine should be timely adjusted according to the control speed of the construction,material characteristics and environmental factors,to provide a theoretical reference for the control of heating temperature and heating rate,heating machine design and construction.