Study On Cold Storage Multi-Temperature Co-Distribution Considering Carbon Emission Under Time-Varying Road

With the accelerated development of the cold chain industry and the continuous upgrading of residents’ consumption capacity,the requirements for temperature diversity in the distribution process become higher,and the requirements for the accuracy of distribution time of cold chain products are also more stringent.Under the research background of cold chain logistics multi-temperature collaborative distribution,this paper considers the time-varying and carbon emission factors of road network.Through the analysis of multi-temperature co-distribution,time-varying road network and carbon emission,the path optimization problem of cold storage multi-temperature co-distribution considering carbon emission under time-varying road network is studied.Firstly,this paper analyzes the problem from the aspects of the design of cold storage multi-temperature co-distribution system,the treatment of time-varying road network and the treatment of carbon emission.The core of the cold storage multi-temperature codistribution system is the refrigerator and cold accumulator.And the overall operation equipment includes ordinary freight cars and freezing machines that provide cold energy.With regard to the treatment of time-varying road network under cold chain transportation,the actual factors affecting traffic conditions are analyzed,and the vehicle speed in congested period and normal period are divided;Under the time-varying function description of time-varying road network based on driving speed,the driving time of vehicles is calculated by using the method of time division.With regard to the treatment of vehicle carbon emission under cold chain transportation,the main sources of vehicle carbon emission under cold storage multi-temperature co-distribution are analyzed,and the influence of vehicle speed and load on carbon emission is considered;According to the variables such as speed,time and distance obtained under time-varying conditions,the comprehensive mode emission model is used to calculate the fuel consumption of vehicles;According to the relationship between fuel consumption and carbon emission,the carbon emission of the vehicle during driving is obtained.Secondly,considering the relevant characteristics of road network and carbon emission factors,the costs of cold storage multi-temperature co-distribution path problem are analyzed;The penalty cost of time window is calculated by using soft time window;Introduce a carbon tax to facilitate the calculation of the cost of carbon emissions.With the goal of reducing logistics investment and improving efficiency,the multi-objective mixed integer model with the lowest total distribution cost and the shortest driving time is constructed.Finally,the fast non-dominated sorting genetic algorithm is used to solve the problem.Before fast non-dominated sorting,this paper uses penalty function to eliminate infeasible solutions in the iterative process.In terms of example analysis,based on the location information of the first 30 customers in Solomon example C101,the algorithm parameters are set,and each run will get a series of Pareto optimal solution sets.Through the sensitivity analysis of carbon tax cost,the time-varying analysis of road network and the analysis of three hypothetical cases,the advantages of this model in the design of cold chain product distribution scheme are verified.The sensitivity analysis of the cost of carbon tax shows that,setting an appropriate carbon tax price within the economic tolerance of enterprises will enable them to choose the best distribution route with low fuel consumption,which is obviously helpful to reduce carbon emissions.The analysis of the time variability of the road network shows that,selecting the best departure time of vehicles can effectively avoid the congestion period,and save distribution time and cost.The scenario analysis makes corresponding scenario assumptions from the perspectives of vehicle speed,carbon emission cost and distribution mode,which further verifies that the model established in this paper can not only meet the needs of distribution temperature diversity,but also deliver goods in an accurate time,save costs and improve distribution efficiency.To sum up,when using the cold storage multi-temperature co-distribution method for path planning of cold chain products,considering the time-varying and carbon emission factors of the road network,it is of great significance in saving costs and improving the accuracy of delivery time.And it provides solutions for realizing energy conservation and emission reduction and optimizing resource allocation path planning.