人工煤气管道萘沉积量预测方法及影响因素研究

On the forecast methods and the influential factors of naphthalene deposition in the artificial gas pipeline

为了研究人工煤气管道内萘沉积量的预测方法及其影响因素,以昆明人工煤气输气干管为例,结合TGNET软件模拟输气干管的运行工况(选用BWRS状态方程,Colebrook-White流动方程)计算管内萘沉积量,通过改变模型参数(地温、输气温度及输送压力)分析萘沉积量的影响因素。结果表明:1)萘沉积量预测方法的计算结果与实际情况的相对误差仅为3.36%,方法可行;2)饱和萘含量随地温降低而降低,随管道输送压力降低而升高,随管道输送温度降低而降低,且管内外温差越大,萘沉积量越大;3)温度变化是造成人工煤气管道中萘沉积并堵塞管道的主要原因,建议在煤气进入城市管网前先对其作降温处理,冬季在弯管、调压器等易出现萘沉积的部位添加保温设施以维持管内温度。

The present article is devoted to finding a forecast method for the artificial gas pipeline working life and the influential factors of naphthalene deposition of such pipelines. In the article,we have taken the pipeline produced in Kunming as a case study sample. In the given paper,we have established a gas transmission hydraulic calculation model state equation and the Colebrook-White flow equation as our calculation standard based on the theory of naphthalene deposition by using a so-called TGNET software. According to the operating conditions of the gas pipeline,the deposition of naphthalene in the gas pipeline manufactured has been worked out,and then compared with the field test results. Furthermore,an analysis has been done on the influential factors( i. e. the ground temperature,the gas transportation temperature and the gas transportation pressure) of the naphthalene deposition in the pipe by changing the model parameters. The results of this analysis prove that the calculation result of the naphthalene deposition prediction method is 19. 384 t/a,and the relative error with the actual result 20. 06 t/a has turned out only 3. 36%. All the aforementioned calculation proves the feasibility of the naphthalene deposition forecasting method. Besides,the content of the saturated naphthalene also proves to decrease with the decrease of the ground temperature as well as the drop-down of pipeline temperature,but increases with the decrease of the pipeline pressure. That is to say,the greater the temperature difference between the inside and outside of the pipe,the greater the naphthalene deposition. Furthermore,temperature change also serves as the main cause of naphthalene deposition and blockage in the manufactured gas pipeline. Thus,it can be suggested that the manufactured gas should be cooled down before the manufactured gas enters the urban gas pipe network to precipitate some large amount of naphthalene. In this way,the naphthalene content in the urban gas pipe system tends to get reduced greatly. What is more,in cold winter days,it would be possible to maintain the temperature inside the pipe invariability and reduce the likeliness of naphthalene deposition by adding a thermal insulation facility or device in which there may take place naphthalene deposition in the pipes,such as elbows and pressure regulators.