西气东输一线管道掺氢输送压缩机运行工况适应性分析

目的将氢气掺入天然气管网会改变气体的组成和物性参数,使离心式压缩机运行工况点发生偏移,影响压缩机进出口压力、功率和能耗。为此,需对掺氢输送压缩机的运行工况进行适应性分析。 方法以西气东输一线管道为研究对象,考虑氢气掺入对天然气物性参数的影响,建立了基于相似换算方法的掺氢天然气离心压缩机特性计算模型、掺氢量为0%~20%条件下的掺氢天然气输送管道仿真模型；分析了掺氢前后在同等输量和同等发热量两种状态下,管道沿线压力、温度、离心式压缩机工况点与性能参数的变化规律。 结果对于同等输量工况,在输量为(2 800～4 500)×10⁴ m³/d,掺氢量为0%～20%时,掺氢量每增加5%,典型R-R型压缩机进口压力、出口压力和压头平均增加3.34%、1.60%和0.39%,压缩机自耗气、功率和压比平均减少0.35%、4.11%和1.64%；对于同等发热量工况,在输量为(2 800～3 500)×10⁴ m³/d、掺氢量为0%～20%时,掺氢量每增加5%,典型R-R型压缩机进口压力、出口压力、自耗气和功率平均增加7.31%、5.37%、4.78%和0.84%,压头和压比平均减少0.11%和1.72%。 结论西气东输一线管道压缩机适用于掺氢输送工况。 

Adaptability analysis of operating conditions of hydrogen-blended compressors in the first West-East gas pipeline

ObjectiveAdding hydrogen into the natural gas pipeline network will change the composition and physical parameters of the gas, cause the operating point of the centrifugal compressor to shift, and affect the inlet and outlet pressure, power and energy consumption of the compressor. Therefore, it is necessary to analyze the adaptability of the operating conditions of the hydrogen-blending transport compressor. Methods Taking the first-line West-East gas pipeline as the research object and considering the influence of hydrogen blending on the physical properties of natural gas, a calculation model of the centrifugal compressor characteristics of hydrogen-blended natural gas based on the similar conversion method was established. Furthermore, the simulation model of the hydrogen-blended natural gas pipeline with hydrogen admixture of 0%-20% was analyzed; the variation law of the pressure, temperature, operating point and performance parameters of the centrifugal compressor along the pipeline was analyzed before and after hydrogen blending under the same transmission capacity and the same calorific value. ResultsFor the same transmission conditions, when the transmission volume was (28-45)×10⁶ m³/d and the hydrogen admixture was 0%-20%, the increase of hydrogen admixture by every 5% would cause the inlet pressure, outlet pressure and pressure head of the typical R-R compressor increase by 3.34%, 1.60% and 0.39% on average, respectively. It would also lead to the reduction of the self-consumption gas, power, and pressure ratio of the compressor by 0.35%, 4.11% and 1.64% on average, respectively. For the same calorific value, when the transmission volume was (28-35)×10⁶ m³/d and the hydrogen admixture was 0%-20%, the increase of hydrogen admixture by every 5% would cause the inlet pressure, outlet pressure, consumable gas and power of typical R-R compressors increase 7.31%, 5.37%, 4.78% and 0.84% on average, respectively. It would also lead the head and pressure ratio decrease by 0.11% and 1.72% on average, respectively. ConclusionThe first-line pipeline compressor of the West-East gas pipeline is suitable for hydrogen-mixed transmission conditions.