External Effects Of Pre-cooling On Fruit And Optimization Of Pre-cooling Node Layout

With the continuous development of China's economy and cold chain logistics industry,people's demand for fresh agricultural products has increased year by year,and higher requirements for quality and safety have been put forward.The cold chain logistics of fresh agricultural products,especially the fruits,has become the mainstream trend.In recent years,the CPC central committee and the state councils have enacted a series of policies to promote the construction of modern cold chain logistics system,emphasizing the importance of cold chain logistics in rural development and food safety.From the perspective of pre-cooling external effect,this paper deeply studies the pre-cooled cold chain logistics model of post-harvest fruit,combines the minimization of costs and the maximization of the external effects of cold chain logistics,optimizes the location of the pre-cooling nodes,and optimizes the front-end cold chain logistics.It reveals the important role of pre-cooling in front-end cold chain logistics and provides policy support for the government.It can alleviate the problems such as high decay rate,high unmarketable corruption and safety accidents due to pre-cooling and incomplete cold chain facilities.The details of this paper are as follows:(1)Summarize the relevant concepts and research methods related to externality,logistics node,cold chain logistics node and so on,and focus on clarifying the connotation and classification of external effects,and then clarify the scope of the external effect in the cold chain logistics.It provides a reference and basis for the model construction of the post-harvest pre-cooling node of the fruit considering the external effect.(2)Conduct a systematic analysis of the current cold chain logistics model for fresh produce.Divided by regions,they can be divided into within and outside the region.Divided into the main business,can be divided into the following three kinds of fresh agricultural products cold chain logistics model: a cold chain logistics mode,which is dominated by alarge-scale processing enterprises,dominated by large-scale wholesale market and dominated by supermarket chains.This article takes into account all factors such as region,business entity,cold chain equipment,and operation link in the existing model,and innovatively proposes a new front-end cold chain logistics model.(3)Calculate the value of the external effects of post-harvest pre-cooling of fruits.Taking fresh fruits as an example,on the basis of a new front-end cold chain logistics model,through literature research,field investigation and induction analysis.The post-harvest pre-cooling of fruits will mainly produce arable land effects,garbage disposal effects,and carbon emissions effects.And then,use the market value method and the equivalent factor method to measure the value of the three external effects produced.(4)Construct a pre-cooling node layout optimization model based on external effects.Under the circumstance of maximizing the external effect of pre-cooling of fruits after harvest,a two stage post-harvest distribution model of fruit is set up.The model consists of two stages:the stage from collection point to pre-cooling center,and the stage from pre-cooling center to the main body of operation.A multi-objective function with minimum total operating cost and maximum external effect is established to optimize the location of pre-cooling nodes.(5)Finally,propose a case study of a pre-cooling node layout optimization model based on external effects for Conghua litchi.On the basis of analyzing the cold chain logistics mode of Conghua litchi front-end,through field investigation,confirm the related location and transportation data,and build the multi-objective model.Under the new cold chain logistics model of Conghua,two new pre-cooling nodes could be built,totally costing 737 thousand yuan.The amount of external effects due to pre-cooling is 68.139 million yuan,which is 92 times the operation cost of the whole pre-cooling center and one-fifth of the total litchi sales for the whole year.The external value of the saving arable land is 49.788 million yuan,the external value of the waste reduction is 18.353 million yuan,and the external value of its carbon emissions is-3119 yuan.