聚酯装置中气相热媒系统的设计与应用

Design and application of gas heating medium system for polyester plant

介绍了气相热媒介质联苯-联苯醚共沸混合物的物理性质和使用要求;分析了在聚酯装置中气相热媒系统的设计与控制方案。提出在气相热媒系统设计中,应减少热媒泄漏,采取程序化升温,先快速升温到216℃,然后缓慢升温至270～295℃;在其配管设计中,要考虑每段管道的特殊性,减少凝液直接回流至热媒蒸发器,一次热媒的流向为蒸发器的下部进、上部出的方式;在聚酯装置开车时,气相热媒的加热应采取液相温度和气相压力共同控制的方法,保证热媒蒸发器的稳定性。

The physical properties and operating requirements of the gas heating medium of diphenyl and diphenylether azeotropic mixture were introduced. The design and control plan of gas heating medium system were analyzed for polyester plant. For the design of gas heating medium system, the heating medium leakage should be avoided and the programmed temperature should be applied which comprised two stages of quickly heating to 216 ℃ and then slowly heating to 270 -295 ℃. For the piping design, the speciality of every pipe section should be taken into consideration, the condensation liquid directly refluxing into the heating medium evaporator should be depressed, and the primary heating medium should flow into the evaporator from the lower part and out from the upper part. Moreover, the heating medium should be heated under the combination control of liquid-phase temperature and gas-phase pressure to ensure the stability of the heating medium evaporator at the start-up of polyester plant.