两万t重载列车空气制动过程建模

Modeling of air braking process of 20 000 ton heavy haul train

针对使用《列车牵引计算规程》规定的牵引计算方法对2万t重载组合列车空气制动过程计算准确性有限的问题,在牵引规程既有空气制动计算模型基础上,提出一种适用于长编组重载组合列车空气制动过程的求解方法。首先,通过分析牵引规程模型的局限性,基于空气制动系统动态行为,按照时间节点将重载列车空气制动过程分别描述为实际系统空走阶段、制动力建立的暂态阶段和制动力稳定发挥的稳态阶段。其次,考虑历史操纵行为对当前空气制动性能发挥的影响,引入空气制动性能修正函数;考虑列车编组形式对制动波分布和制动波传递的影响,引入组合列车闸瓦压力分布函数。然后,基于牵引规程空气制动力基本计算方法,考虑制动全过程中空气制动力分布的连续性,提出一种三段式精细化空气制动力计算模型。最后,基于2万t重载列车实车运行数据,定义模型误差评价函数,通过与既有牵引规程模型对比,论证精细化模型的正确性和有效性。研究结果表明,所提模型在仿真重载列车单次短坡道制动和长大下坡道循环制动工况下都有良好的适应度。

In view of the limited accuracy of the traction calculation method specified in the code for train traction calculation in solving the air braking process of 20 000 ton heavy haul combined trains, based on the existing air braking calculation model of traction gauge, an air braking process solution method suitable for long marshaling heavy haul combined trains was put forward. Firstly, by analyzing the limitations of the traction gauge model and based on the dynamic behavior of the air braking system, the air braking process of heavy haul train was described as idling stage, braking force establishment transient stage and braking force stability steady-state stage according to the time node. Secondly, considering the influence of historical handling behavior on the current air braking performance,the air braking performance correction function was introduced;considering the influence of train formation form on brake wave distribution and brake wave transmission, the brake shoe pressure distribution function of combined train was introduced. Then, based on the basic calculation method of traction gauge air braking force and considering the continuity of air braking force distribution in the whole braking process, a three-stage refined air braking force calculation model was summarized. Finally, based on the actual operation data of20 000 ton heavy haul train, the model error evaluation function was defined, and the correctness and effectiveness of the refined model were demonstrated by comparing with the existing traction gauge model. The results show that the model has good adaptability under the conditions of single short ramp braking and long downhill cyclic braking of heavy haul train.