Linde LNG terminal pre-cooling project
-CNOOC Tianjin Liquefied Natural Gas (LNG) Co., Ltd.
CNOOC Tianjin LNG Co., Ltd.
Aiming to "dedicate clean energy and create a better life", CNOOC Tianjin LNG Co., Ltd. is committed to promotion and use of clean energy of LNG. It is the first enterprise to introduce floating LNG receiving terminal technology in China. Tianjin LNG project led and constructed by CNOOC Tianjin LNG Co., Ltd. is not only a pilot clean energy project nationwide and key project in Tianjin, but also a key project launched by CNOOC.
In the light of Tianjin LNG discharge pipeline pre-cooling project of CNOOC, Linde is required to inject cryogenic nitrogen into the discharge pipeline pursuant to the cooling curve before discharge of LNG from carrier ship so as to cool the temperature of pipeline from room temperature to -120℃ and thereby minimize the waste caused by evaporation of low temperature LNG within the pipeline and the emissions to the atmosphere.
At present, there is no sophisticated plan for pre-cooling of LNG pipelines in China. In the event of any negligence in planning or any error in operation, there will be temperature stratification within the pipeline, or even accumulation of liquid nitrogen at excessively low temperature at bottom of pipeline, thus causing damages to the equipment. Linde's project plan can ensure that the nitrogen injected into the pipeline at each injection point will accurately cool the pipeline to the set temperature within the time limit as required and prevent fluid accumulation or temperature stratification in pipeline.
Based on the time spent on LNG pipeline pre-cooling, Linde team worked on device configuration and plan design in view of actual layout and length of pipeline on site and features of Linde equipment. The difficulties of the plan are how to prevent fluid accumulation and temperature stratification in the pipeline. So during the entire plan, it is imperative to cool the temperature in strict accordance with the set cooling curve. Linde Tianjin team employed software to make meticulous estimate for nitrogen injection amount at each injection point and the change in temperature, repeatedly communicated with customers and performed research on site to prepare a comprehensive plan on various potential emergencies likely to occur in the course of operation. LNG pipeline pre-cooling project was completed in November 2014 to the satisfaction of our customer.
In this project, Linde helped customer reduce waste of cryogenic LNG, to save valuable energy consumption and decrease gas emissions into the atmosphere. Should further optimization steps be taken in the future, the digital instrumentation will play an even greater role in automatic detection and control, with introduction of liquid nitrogen atomization technology, to control the amount of liquid nitrogen more precisely and save manpower cost.
Owing to the outstanding performance and excellent service in CNOOC Tianjin LNG pre-cooling project, Linde has established a good reputation, and ranked among CNOOC’s qualified suppliers for LNG pre-cooling project, which has laid a solid foundation for more cooperation between Linde and CNOOC in the future.