The optimaztion of train collection strategies in coal ports with eco-friendly yards: A case study in Nothern China

Eco-friendly yards, in which coal is stored in closed silos, can reduce the dust pollution in coal ports. However, the daily operation of coal ports with eco-friendly yards involves complex management strategies such as train collection strategies, storage strategies and so on, which should be studied to enhance the efficiency and cut down the cost. Thus, this paper aims to optimize the key train collection strategies from two aspects: economy and safety. Firstly, we analyze the handling operation process in coal terminals. On this basis, a simulation model of the coal ports with eco-friendly yards is built. Then, a time-cost model is used to do quantitative research on economic cost, while the number of silo-changing times is used as the index of security cost. Finally, a case study in northern China is done. The results show that if the ratio of the ship cost to the train cost is less than 12.7, short train collection period is benefit to cut down the time cost, the scheme 1 whose train collection period is 3 days, has about 22.7% higher cost than scheme 5 whose train collection period is 7 days. When the value is greater than 16.4, we should increase the train collection period. If the ratio is between 12.7 and 16.4, train collection period has little effect on time cost, the gap between scheme 1 and scheme is not more than 3%. In addition, shorter train collection period will lead to less silo-changing times which is benefit for the safety cost.