燃气驱动天然气压缩机厂房通风设计要点

Key Points of Ventilation Design for Gas-driven Natural Gas Compressor Plant

压缩机增压提产是长庆油田天然气生产重要的地面工艺技术,燃气驱动天然气压缩机应用最为广泛。燃气驱动天然气压缩机在运行中产生热量大,而现行各类规范仅从安全角度提出通风要求,未对厂房内的排热做出明确的要求和指导。根据设备厂家提供的机组工况数据,对燃气驱动压缩机燃烧热量转化进行分析,发现燃烧热量主要转化为输出功、烟气热以及发动机散热。将天然气压缩近似看作绝热压缩过程,采用Lee-Kesler(李-凯斯勒方程式)法计算两级压缩前后天然气焓值变化,得到压缩过程散热量。综合发动机散热和天然气压缩散热,得到不同工况下散入压缩机厂房内的热量,并计算所需的排风量及补风量。通过比较发现压缩机空冷器风量太大,应将排风直接导出室外,不宜直接排放到室内;经过举例计算,压缩机的输出功率会全部转化为热量散失;空冷器排风导出室外的情况下,压缩机厂房散热所需全面通风量仍然比安全所需通风量要大得多,设计中应同时计算取较大者。

Compressor boosting is an important surface technology for natural gas production in Changqing Oilfield,and the gas-driven natural gas compressor is the most widely used.The gas-driven natural gas compressor products a lot of heat in operation,but current design codes only put forward ventilation requirements on safety and do not make clear requirements for heat dissipation in the plant.According to the unit working condition data provided by the equipment manufacturer,the combustion heat conversion of gas-driven compressor is analyzed,and it is found that the combustion heat is mainly converted to output power,flue gas heat,and engine heat dissipation.The natural gas compression is approximately regarded as an adiabatic compression process,the Lee-Kesler Method is used to calculate the change of natural gas enthalpy value before and after two-stage compression to obtain the heat dissipation during the compression process.Combined with engine heat dissipation and natural gas compression heat dissipation,the heat dissipated into the compressor plant under different working conditions is obtained,and the required exhaust air volume and supplement air volume are calculated.Through comparison,it is found that the air volume of air cooler of the compressor is too large,and the exhaust air should be directly exported to the outside rather than directly discharged to the indoor.Through example calculation,the output power of the compressor is completely converted into heat loss.When the exhaust air of the air cooler is exported to the outside,the overall ventilation required for the heat dissipation of the compressor plant is still much larger than the ventilation required for safety,so both value should be calculated in the design and the larger one should be taken.