expansion project短语¹⁴⁴⁹⁷²⁺² 基本例句 扩建企业 建立业务关系 The optimization and method of startup and shutdown of Tianjin ethylene expansion project is introduced in the paper, providing suggestions for other ethylene expansion project. 文中主要阐述天津联合化学有限公司乙烯装置挖潜改造开停方案优化与方法，为同行业乙烯装置挖潜改造提供借鉴。 chemyq