The Research On The Coal Inventory Capacity Of Coal-fired Power Plants

The power industry is the foundation of the national economy, and relates to the sustained and healthy economic development and social harmony and stability. Since China is the second-biggest coal supplier and consumer in the world, power generation by coal plays a dominant role in power industry for a long time. The coal in our country is mainly located in the northwest, but coal-fired power plants are usually built on the southeast coast, which leads to the mode of "coal transport form north to south and west to east" in coal transportation. Although the seaway transportation has advantages of large quantity and low unit costs, which are benefic in reducing logistics costs of fuel supply for power plants, the seaway transportation is seriously influenced by port operating conditions, sea hydro-meteorological factors and so on, that has an effect on the accuracy of the time for ships' arrival, bringing certain difficulties to control the reasonable fuel inventory.Because the power generation needs to ensure continuous production, and electricity can not be stored, we must set up safety stock levels to accommodate this situation. Despite of the increase of fuel stocks is in favor of safely production for power plants, but the high level of inventory holding costs will undoubtedly increase the supply costs of power plants, furthermore, affect the corporate profits. In order to reduce the fuel supply logistics costs of power plants, it is necessary to rationally determine the safety stock levels of power plants.In this paper, establishes safety stock model of sea coal supply of coastal power plants, through analyzing the composing and characteristics of sea-coal supply logistics system, including the fluctuations of the sea coal supply, uncertainties in the demand of power plants and the possible delays in transportation and lead time fluctuations due to the risk of incidents. By identifying the optimal supply quantity based on certain service level, perform an optimize analysis on determining the fuel yard capacity of discharging ports in the view of supply chain. What is said above provides a scientific analyzing method and warranty for decision-making for power plants to identify reasonable fuel yard capacity of the power plants.Through the analysis on the rates of demand and supply, related costs of S power plant, combined with characteristics of fuel transportation, the paper establishes the cargo timely replenishment optimal order quantity model to the fuel yard stock of discharging ports. In addition, according to the demand characteristics of the fuel of power plants, using related theories in statistics and control theory, we can determine the maximum inventory levels for power plants under different levels of out-of-stock when power plants operates in peak and average situation respectively. The research achievement of this paper, not only can be used to the construction planning of the sea-coal discharging ports of coastal power plants and the capacity of coal yard, but also has a guiding role in reducing inventory of sea coal effectively and saving the cost of fuel supply.