The Design And Development Of The Temperature Balance Control System For The Multi-channel Tubes Of The USC Type Ethylene Cracking Furnace

Ethylene cracking furnace is an important equipment in petrochemical production process.The outlet temperature of multiple furnace tubes of cracking furnace should be kept in balance,otherwise there will be problems such as coking or insufficient cracking depth of furnace tubes.Therefore,it is very important to realize the balance control of the outlet temperature of multi-channel furnace tubes.However,relying on the existing equipment,conventional control is difficult to meet the complex industrial needs.In order to improve the precision of temperature control at the outlet of multi-channel furnace tubes and ensure the quality of products,an advanced control scheme of branch balance is proposed.The main research contents are as follows:Firstly,the background significance of branch balance in ethylene cracking furnace is introduced,and the research status of advanced control algorithm for temperature at the outlet of multiple furnace tubes is analyzed.Type and 12 sets of USC at Hengli petrochemical ethylene cracking furnace as the research object,the process flow of ethylene cracking furnace,analysis the existing conventional control scheme,based on this,advances multiplex outlet temperature of the furnace tube balance branch balance of advanced control scheme,this scheme can be applied for multiple conditions of different patterns of advanced control system.Secondly,the implementation of the site project is elaborated in detail.OPC communication configuration was carried out based on APC-ISYS advanced control platform（upper computer）,the real and virtual bit numbers were configured,the dynamic mathematical model of ethylene cracking furnace was established,and the algorithm of advanced controller was written.Based on the Centum VP platform（lower computer）in Yokogawa,the advanced control interface logic and the configuration of DCS operation interface can be realized,such as error reporting and real-time trend chart viewing.Finally,the designed multi-channel tube temperature balance control system was applied to 12 USC ethylene cracking furnaces of Hengli Petrochemical Co.,Ltd.Taking furnace A of No.1 and furnace B of No.4of Hengli Petrochemical Co.,Ltd.,as an example,A detailed comparative analysis was made on the effects before and after its application.Compared with the original conventional control,the application of advanced control scheme of multi-channel furnace tube outlet temperature balance,the fluctuation range of multi-channel furnace tube outlet temperature is obviously smaller,the temperature of each branch is more stable,has good anti-interference ability,can ensure the long-term safe operation of the device.