Ethylene rectification tower sensitive plate temperature control system and control method thereof

Abstract

The invention relates to an ethylene rectification tower system belonging to an ethylene device and a control method thereof. The invention provides a sensitive plate temperature control system and a control method thereof by combining the process operation characteristics in an ethylene rectification production process, comprehensively using latest technology in chemical engineering and automatic control science and adopting nonlinear control theory. The system and the method perform balancing control of the temperature deviation of discharged materials of two reboilers by arranging a temperature balancing control circuit and online adjustment of the flow rate of a heating medium entering the two reboilers and a load distribution proportion, ensure the gas and liquid phase balance in an ethylene rectification tower, stabilize the temperatures of a control sensitive plate and the discharged materials, overcome external disturbance caused by changes in the temperature and pressure of the heating medium, lay a firm foundation for the stable operation of the whole rectification tower and the 'optimized' operation of product quality, fully use the DCS in the ethylene device and the potential of operational equipment, and effectively utilize raw material and energy.

Description

technical field [0001] The invention relates to an ethylene rectification tower system in an ethylene plant and a control method thereof, in particular to an ethylene rectification tower sensitive plate temperature balance adjustment system with double reboilers and a control method thereof. Background technique [0002] In the process of ethylene production, the ethylene rectification tower is an important equipment of the production unit. Whether its operation is stable or not will not only affect the product quality and output of the entire ethylene rectification tower, but also directly affect the downstream production units (such as polyethylene, acetic acid , ethylene glycol, polyvinyl chloride and other devices) smooth operation. [0003] At present, all ethylene plants in China adopt the basic control functions of Distributed Control Systems (DCS) to monitor the production process. These basic control systems ensure the safe operation of the ethylene rectification to...

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Problems solved by technology

[0003] At present, all ethylene plants in China adopt the basic control functions of Distributed Control Systems (DCS) to monitor the production process. These basic control systems ensure the safe operation of the ethylene rectification tower. Effective control, the load of the gas phase and liquid phase in the tower fluctuates greatly, and the temperature of the sensitive plate as the indicator of the component content in the tower still fluctuates greatly, which greatly affects the stable operation of the ethylene rectification tower

[0004] The ethylene rectification tower is a very complex precision distillation process; the process operation and automatic control of this system are relatively difficult, and its stable control has always been one of the difficult problems to be solved in the ethylene production process at home and abroad, especially for those with two In the rectification tower of the boiler, because the characteristics of the two reboilers are not completely consistent, it is difficult to match and control the heating load of the two, and the temperature of the sensitive plate fluctuates greatly, which seriously affects the stable operation of the rectification tower. Difficulties in Stable Control of Distillation Column

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