油气田在用燃气轮机系统的热力学分析及改进建议

目前油气田在用的燃气轮机系统实际运行指标（热效率及火用效率）与设计数值相差很大，使燃气轮机系统的性能未能得到充分发挥，达不到预期的经济效益，限制了燃气轮机在油气田的进一步推广。为此，对油气田在用燃气轮机的运行特性进行分析，其主要问题是余热锅炉运行时间短、负荷率低。根据燃气轮机热电联产系统特点，给出了热力学分析（能量平衡分析和火用分析）方法、评价准则及计算公式。利用实测运行参数，对一油气田在用燃气轮机系统进行了运行工况下的热力学分析。测算分析结果表明，该系统运行效率偏离设计值较远，运行效率较低。在各子系统的能量损失分布中，余热锅炉能损系数最大；火用损分布中，燃烧室火用损系数最大，其次为余热锅炉，表明燃气轮机的燃烧室和余热锅炉为系统能量利用的薄弱环节，为重点改造对象。建议扩大集中供热范围、采用余热发电和循环蒸气回注等提高运行效率的措施。

THERMODYNAMIC ANALYSIS METHOD AND ITS APPLICATION ON THE GAS TURBINE CHP SYSTEM IN OIL FIELDS

Because a seriously big gap is found out between the designed values and the actual parameters like heat efficiency and xergy rate collected from those in service gas turbines in the oil fields, the gas turbine CHP system can not be fully used, resulting in bad effects on the expected economic profit and then restricting its application in the oil fields. Therefore, focusing on the operation performance of gas turbines in the oil fields, this study discovered major problems like short operation time and low loading rate in the HRSG (heat recovery steam generator). In light of features on the gas turbine CHP system, this study put forward thermodynamic analysis method including energy equilibrium and exergy analysis, evaluation criterion, and calculating formula. According to the actual performing parameters, this thermodynamic analysis method was testified on the gas turbine CHP system under working conditions at a certain oil field. The analysis result showed that the low operation efficiency of this system departed from the designed value; and the energy loss in the HRSG was the greatest among those in subsystems, while the exergy loss is most serious in the heat chamber, and the HRSG was next to it. This paper suggests that the heat chamber and the HRSG should be innovated as the major points to improve the utilization efficiency of energy, and the CHP system operation rate should be enhanced by taking such measures like extending the central heat supply, generating power by the recovered heat, re injecting the recycling steam, and so on.