风浪流影响下的船舶废气排放测度模型研究

Calculation model for ship exhaust emissions on a count of the impacts of wind,wave and water current included

船舶速度是船舶废气排放量计算的重要影响因子。为更加准确地测度船舶废气排放量,考虑海洋环境场对船舶速度的影响,分析了风、浪、流影响下的船舶运动,利用获取的实时风、浪、流信息对船舶AIS提供的航速进行修正,在此基础上建立了风、浪、流影响下的船舶废气排放测度模型,并介绍了船舶引擎功率的估算方法,以及排放因子和负荷因子的确定。最后,选取某散货船和客滚船的两个航次,分别采用传统模型和风、浪、流影响下的船舶废气排放计算模型进行计算,以CO2排放量反推油耗,并计算其与实际油耗的误差,结果表明,与传统模型计算结果相比,基于风、浪、流影响下的船舶废气排放测度模型得到的误差均有所减小,分别减小16.90%、18.60%、21.59%、21.94%,验证了模型的有效性。

This paper takes is as its target to verify the effectiveness of a certain bulk carrier and ro-ro passenger ship navigating in the waters as a proposed model so as to work out the impacts of the wind,wave and current on the amount of ship exhaust emissions of each voyage,respectively. Actually,we have made experiments through the total four voyages as a case study sample through a comparative study of the said modified model. As is well known,ship speed is in fact one of the key influential factors on the calculation of the ship exhaust emissions. Therefore,in this paper,we have first of all calculated and analyzed the amount of ship exhaust emissions accurately as much as possible,while taking into account the influential factors of the ocean environment,the motion of the ship under the effect of wind,wave and current in combination of the data of the speed over the ground and the real-time information of the ocean environment. And,then,we have established a calculation model of ship exhaust emissions with the influence of the ocean environment. At the same time,the paper has also introduced the estimation method of the ship engine power and the way to determine the emission factors and the loading factors,so that the calculation results of CO2 emissions have been worked out over the amount of the fuel consumption,with the errors between the calculated value of fuel consumption and the actual value of the fuel consumption acquired from the Ship＇s Fuel Consumption Report. The results show that it is possible to reduce the errors with the help of the modified model,with the decrease of the error percentage at the rates of 16. 90%,18. 60%,21. 59%,21. 94%,respectively,which have well shown the advantage of the model proposed in this paper as compared with the model which does not include the influence of the ocean environment. Thus,the research findings in this paper can provide a feasible approach to the calculation of ship exhaust emissions while considering the impact of wind,wave and current in the ocean environment.