| With the improvement of the quality of life and consumption level of Chinese residents,the demand for fresh cold chain products is rising,and China’s cold chain logistics industry is in a rapid growth stage.Currently,the transportation industry is the second largest source of global carbon emissions,of which the cold chain logistics industry has higher energy consumption and carbon emissions compared to the ambient logistics industry,and is an important part of the logistics sector to carry out industry greening reform.It is against this background that this paper chooses to study the optimisation of cold chain logistics distribution routes from a green and low carbon perspective.Firstly,the current distribution of multi-category cold chain products generally adopts a multi-vehicle model,but there are disadvantages such as low vehicle loading rate,high refrigeration cost,high loss rate and high carbon emission.For this reason,considering the perishable characteristics of cold chain products,in order to reduce product loss and improve consumer satisfaction,this paper introduces the multi-temperature co-delivery mode,and after comparing the advantages and disadvantages of the two realisation methods of mechanical refrigerated vehicles and stored-cooled ambient vehicles,the stored-cooled type is chosen to realise this mode.Secondly,in order to improve the efficiency of vehicle traffic and avoid road congestion,this paper considers the influence of the actual road conditions during the distribution process,and introduces the traffic congestion index to portray the speed of vehicle traffic,and uses a time-varying model to calculate the travel time of vehicles under different time periods.At the same time,a load estimation model is used to calculate the carbon emissions in the process of vehicle distribution,and a carbon tax is introduced to calculate the carbon emission cost.Subsequently,this paper constructs a cold chain distribution path optimisation model with the objective of minimising the total distribution cost.The total cost of the model includes vehicle fixed cost,vehicle transportation cost,refrigeration cost,carbon emission cost and penalty cost.In order to solve the constructed model,the ant colony algorithm is chosen as the base algorithm of this paper.After studying the principles and defects of the traditional ant colony algorithm,the traditional ant colony algorithm is improved from various aspects such as heuristic factors,selection of movement probability,pheromone update strategy,etc.,and the2-opt local optimization algorithm is mixed in.Finally,I selected the Wuxi fresh community group purchasing platform as an example and used MATLAB software to solve this paper’s model,comparing the calculation results of this paper’s improved algorithm and other ant colony algorithms to confirm the advantages of the improved algorithm’s performance;at the same time,the model was solved from several perspectives,such as not considering the actual road conditions,using the traditional multivehicle model and not considering the cost of carbon emissions,to analyse the solution results under different modes.The effectiveness of this paper’s path optimisation model is confirmed.In summary,in the actual distribution business of cold chain products,considering the actual road traffic conditions and carbon emission costs,and introducing multi-temperature codistribution mode can effectively reduce the costs of distribution,reduce the loss of cold chain products,and improve the green level of transportation process and user satisfaction.The optimization model of cold chain multi-temperature co-distribution path and the improved ant colony algorithm studied in this paper can provide certain reference value and practical basis for relevant logistics enterprises and departments. |
