前言 随着我国石油工业的迅速发展,长输油气管道工程日益重要。埋地大口径薄壁弯头的升温载荷问题,是解决热油气长输管道强度问题中的一个重要环节。 地上管道弯头的升温载荷计算方法,在一般热力管道科技书中都有论述。但是埋地弯头的升温载荷计算,到目前为止尚未见到理论性分析资料。工业部门由于缺乏依据,过去设计热油气长输管道中的埋地弯头时,只计算内压应力,而不计算温度应力。因此,投产后 Preface With the rapid development of China’s oil industry, long-distance pipeline projects are increasingly important. Buried large-diameter thin-walled elbow heating load problem is to solve the problem of long-distance hot oil and gas pipelines in an important part of the problem. The calculation method of the heating load of the pipe bend on the ground is discussed in the general thermal pipe technology book. However, the calculation of the heating load of the buried elbow has not seen any theoretical analysis so far. Due to a lack of basis in the industrial sector, in the past when designing the buried elbow in a hot-oil and gas long-distance pipeline, only the internal compressive stress was calculated without calculating the temperature stress. Therefore, after putting into production