Method for automatically controlling switching of large valve of ethylene cracking furnace

Abstract

The invention discloses a method for automatically controlling switching of a large valve of an ethylene cracking furnace. The method comprises the steps that initialization and initial allowable workinspection are carried out, a cracking furnace mode is switched to a large valve automatic switching mode from a hot standby mode, differential pressure stable state judgment logic is started, the closing action of a cracking gas large valve is started, and the cracking gas large valve is stopped from being closed until the large valve differential pressure PDZI reaches a first set value; after the pressure difference of the PDZI large valve reaches a first set value, the action of opening a decoking gas large valve is started; after a certain valve position of the decoking gas large valve isopened, differential pressure stable state judgment logic is started, the decoking gas large valve is continues opened after differential pressure is stable, and opening of the decoking gas large valve is stopped until the PDZI differential pressure is smaller than a second set value; and the operation is repeated until the pyrolysis gas large valve is completely closed / the decoking gas large valve is completely opened. The method has the advantages of fast adaptive control response, reduction of manual operation, facilitation of improvement of the stability of the cracking furnace mode switching process and the control precision of the differential pressure, and reduction of the safety risk of the device.

Description

technical field [0001] The invention relates to an automatic control method for switching large valves of an ethylene cracking furnace. Background technique [0002] The ethylene industry measures the development level of a country's petrochemical industry and has always been regarded as a symbol of petrochemical development. With the continuous development of computer application technology and automatic control technology, the process control system is an important guarantee to ensure the safe and efficient operation of ethylene production equipment. The ethylene production process implements computer control and optimized operation, and comprehensively applies chemical engineering technology, computer programs and automatic control strategies to give full play to the inherent potential of the plant equipment, and obtain high economic benefits of the plant through energy saving, low cost consumption and high-load production . [0003] The cracking furnace is the core equ...

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Problems solved by technology

This process has strict technical requirements for personnel operation and high risk. At present, there is no research and development of relevant control technology; secondly, the stable operation of the cracking furnace requires a large number of operators, who need to pay continuous attention to key parameters, and the operation error tolerance rate is low. ; At the same time, different personnel have different experience in operating key parameters, and the impact on the equipment body caused by the operation is large, which is likely to cause fluctuations in the downstream compression and separation systems caused by the operation of the cracking furnace

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