热油循环方法回收利用燃气透平机烟气余热——海上气田燃气透平机烟气余热的回收利用

Recyling of residual heat from a gas turbine's flue gases in offshore oil and gas fields

由于受海洋特殊地理环境、生产设施及投资成本等因素的制约,目前海上油气生产对燃气透平机烟气余热的回收利用还是一个空白。为此,针对海上平台淡水资源缺乏、平台空间有限的特点,结合中海石油有限公司湛江分公司崖城气田的工艺流程,在优选燃气透平烟气余热回收利用方案的基础上,提出了热油循环方法回收利用燃气透平机烟气余热的设计方案:拆除三甘醇再沸器的直燃式加热火管及其燃料气控制系统,在三甘醇再沸器里面安装热油盘管,在燃气透平机烟囱内部安装一个烟气/热油换热器,用于回收燃气透平机的烟气余热,将热油加热到245～300℃之间,建立一套热油循环系统,持续地将已加热的热油输送到热油盘管,加热三甘醇再沸器里的富液三甘醇。可行性及经济性分析表明:该方案需要改造和增加的设备少、体积小,平台空间占用少,改造工作量少,工程实施的技术难度不大,生产操作可靠性高,可行性强,初期投入资金(305.5万元)、生产操作及维修保养成本较低(35.1万元/a);每年可实现的节能减排量为1 955.023t标准煤、可节约燃料气161×104 m3,折合节约费用322万元,经济效益可观,节能减排效果明显,应用前景广阔。

There is still a blank space in the recycling of residual heat from a gas turbine's flue gases in offshore hydrocarbon fields due to the restriction by such factors as specific geological environment,production facilities,and investment costs,etc.Such a study in a sea environment is complicated for lack of freshwater resources and enough platform space.Therefore,in combination with the case history of Yacheng 13-1 Gas Field operated by the CNOOC Zhanjiang Limited and based upon the optimized schemes,a project is presented of using the thermal oil recovery methods for the recovery and utilization of flue gas residual heat from a gas turbine.In this project,the direct-fired heater and its fuel gas control system are demolished in a TEG reboiler,instead,a heating oil coil is installed inside and a flue gas/thermal oil heat exchanger is assembled in its chimney.In this way,the flue gas residual heat from this fuel turbine is then recovered to heat the oil up to 245-300 ℃,and a set of thermal oil recovery system is formed to continuously send the heated thermal oil to the heating oil coil,thus,the rich fluid is heated in the TEG reboiler.Through an analysis of this project's feasibility and economic efficiency in a case study,the following two results are concluded herein.First,in this project,few facilities are to be modified or added and less occupied space is needed,therefore,less reconstruction engineering work is actually needed with less difficulty whereas the operation is of high reliability and practicability.Second,with the preliminary input of RMB 3.055 million Yuan,the operation and maintenance cost is rather low with RMB 0.351 million Yuan per year,as a result,the annual capacity of energy saving and emission reducing is calculated to be 1955.023 tons of standard coal consumption and 161×104 m3 of the fuel gas per year,being converted to RMB 3.22 million Yuan as the saving cost each year in the end.This case study shows that this project has a prospective application with significant economic profit and obviously good results in energy saving and emission reducing.