高海拔公路隧道运营通风海拔高度系数研究

With the development of road construction in Tibetan areas, there will be more and more high-altitude road tunnels, although there have been more than 10 road tunnels whose altitudes are over 3000 meters. However, the current situation is that there are not enough elaborate studies on high-altitude tunnel ventilation in current domestic and foreign tunnel specifications and codes and the altitude coefficients which can be used and found are only the design values whose altitudes are individually 2200m for CO and 2400m for VI, which brings about some challenges when high-altitude road tunnels ventilation are done. Not only does the altitude affect altitude coefficients (CO,VI), but also the emission standards and the vehicle types affect the altitude coefficients a lot. In order to demonstrate the relationship between these 3 factors and the altitude coefficient more clearly ,some studies are done in this subject.Firstly, field tests about altitude coefficients are done with four emission standards and the formula about changes with emission standards are put forward.Secondly, each vehicle type is chosen to do field tests.In this part, the relationship between altitude coefficient of each vehicle type and separate car is studied and the altitude coefficient correction formula changes with vehicle type is proposed. Finally,different vehicle type under each emission standard is chosen to do field tests. Altitude coefficient of each vehicle type under different emission standards is studied and altitude coefficient correction formula based on each vehicle type for four kinds of emission standards is proposed. There have been four kinds of emission standards in China since 1995 and thus the car ownership data are counted for statistics samples.Also, some mathematical formula are established to determine the weight of four kinds of emission standards vehicles. From this comprehensive research ,the altitude coefficient is put forward.In addition, conclusions drawn from this study would provide a theoretical basis for the road tunnel ventilation design.

我国海拔高度3000m以上的公路隧道已超过10座，随着藏区公路的发展，高海拔公路隧道将越来越多。现行的国内、外公路隧道规范对高海拔隧道通风研究甚少，只给出了海拔高度2200m（CO）和2400m（VI）以下的海拔高度系数设计值，这给高海拔公路隧道通风设计带来巨大难题。海拔高度系数（CO、VI）不但与海拔高度有关，还与排放标准、车型关系极大。本课题首先选择四种排放标准单车进行海拔高度系数现场实验，提出每种排放标准单车海拔高度系数随海拔高度变化公式。然后对四种排放标准分别选择不同车型进行现场实验，研究每种排放标准下各类车型的海拔高度系数与单车的关系，提出每种排放标准海拔高度系数随海拔高度变化的车型修正公式。以1995年以来我国四种排放标准汽车保有量数据为样本，建立数学模型，通过分析，确定海拔高度系数对应四种排放标准的权重。综合研究，提出高海拔公路隧道海拔高度系数，为隧道通风设计提供理论依据。

经统计，目前我国已建和在建海拔超过3000m的公路隧道约15座。其中，雀儿山隧道为目前世界上海拔最高的公路隧道，已达到4300m；长度最长的高海拔公路隧道为巴郎山隧道，已达到7940m。随着西部地区的快速崛起，特别是藏区公路的建设，将会修建越来越多的高海拔公路隧道。.由于海拔高度的增加，使得大气压力降低，从而使汽车发动机进气量减少，发动机气缸内的混合气变浓。这一现象除直接导致车辆动力性能降低之外，还使汽油车和柴油车的污染物排放量发生变化。尤其是在高海拔地区所修建的长隧道或特长隧道，更应考虑海拔高度变化对隧道通风设计带来的影响。目前我国公路隧道通风的设计依据是交通运输部发布的《公路隧道通风照明设计规范》（JTJ026.1）。在该规范中，对汽车污染物排放量的变化用修正系数的方式给予了处理。即：以海拔标高400 m为基准高度，进行有害气体排放量的计算。大于海拔标高400 m的基准高度时，则乘以一个大于1的系数进行修正，这个系数称为“海拔高度系数”。.然而，经过近50年的时间，世界范围内机动车排放标准和车型均发生了巨大变化。因此，采用规范进行隧道需风量计算时存在三个问题：排放标准对海拔高度系数影响规律；车型对海拔高度系数的影响规律以及高海拔隧道海拔高度系数的确定方法。 .本课题采用现场测试、理论分析和数值模拟的方法对单车随海拔高度变化的排放系数、汽油车和柴油车在不同海拔高度下的海拔高度系数等进行了研究。.通过理论分析得到了柴油车及汽油车的排放机理，对柴油车烟雾排放及汽油车CO排放进行了海拔400m-4500m的现场测试，得到了补充车型尾气排放的实测数据，建立了海拔超过2400m考虑混合车型的烟雾海拔高度系数计算公式。结合依托工程，对省道303巴朗山隧道营运通风设计提出了建议，并运用实测考虑烟雾及CO海拔高度系数值重新进行了通风修正设计保障了通风安全。对类似工程有参考作用。.依托本课题开展的研究，在相关杂志和期刊上发表了6篇文章，申请专利1项，获奖1项。培养博士1人，硕士2人；已毕业博士和硕士各1人。

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