Predictive Controller for Acetylene Plant Suction Pressure
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Solution Overview
Problem
Modern acetylene production plants with reduced buffer volume, lacking electrostatic filters and gasometers, face challenges in maintaining continuous operation due to abrupt changes in mass flow rates, leading to frequent shutdowns and increased apparatus wear.
Innovation Solution
Implementing a higher-level model-supported predictive controller in conjunction with conventional controllers to manage suction pressure and mass flow rate changes, allowing for controlled recycling and diversion of reaction gas, thereby preventing abrupt pressure fluctuations and ensuring continuous operation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If conventional controllers with slow control characteristic are used to maintain suction pressure, then normal operation is smooth, but abrupt changes in mass flow rate cannot be controlled, leading to pressure leaving permissible range and plant shutdown
Solution Approach 1:
The higher-level model-supported predictive controller performs preliminary action by calculating and reacting to abrupt changes in mass flow rate before they cause pressure to leave the permissible range. The controller predicts future states based on process models and proactively adjusts control variables to prevent shutdown conditions.
Solution Approach 2:
The higher-level model-supported predictive controller acts as an intermediary between the conventional controller and the process. It receives information about abrupt mass flow changes and translates them into appropriate control actions, mediating between the slow response of conventional controllers and the need for rapid response to maintain reliability.
2Device complexity
If buffer volume is reduced to avoid gasometer and electrostatic filters, then capital costs are reduced, but ability to buffer changes in load is reduced, leading to frequent shutdowns
Solution Approach 1:
The patent replaces mechanical buffer systems (gasometers and electrostatic filters) with a control-based system. Instead of using physical volume to buffer load changes, the invention uses a higher-level controller that actively manages mass flow rate changes, substituting mechanical buffering with intelligent control.
Solution Approach 2:
The invention changes the approach from physical parameter buffering (volume) to control parameter management (mass flow rate). By actively managing and adjusting mass flow rate parameters through the predictive controller, the system compensates for the reduced buffer volume without requiring additional physical infrastructure.
3Productivity
If mass flow rate changes abruptly due to reactor failure or compressor failure, then production continues, but suction pressure leaves permissible range causing shutdown of compressors or reactors
Solution Approach 1:
The higher-level model-supported predictive controller implements feedback by continuously monitoring mass flow rate changes and adjusting control variables accordingly. When abrupt changes occur due to reactor or compressor failures, the controller receives feedback about these changes and actively counteracts their impact on suction pressure, preventing shutdown conditions.
Solution Approach 2:
The controller performs preliminary action by detecting and reacting to abrupt mass flow rate changes before they cause suction pressure to leave the permissible range. This proactive response prevents the cascade shutdown that would otherwise occur, maintaining both productivity and pressure control reliability.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This solution enables continuous acetylene production by effectively managing sudden changes in mass flow rates, reducing shutdowns, and minimizing apparatus wear, thus preventing disruptions to upstream and downstream plants and improving operational smoothness.
Implementation Method 1
the pressure of the reaction gas mixture on the suction side of the compressor being controlled within a predefined range
Implementation Method 2
The cleavage gas obtained is subsequently compressed and then separated in a known manner
Implementation Method 3
The flame reaction at temperatures above about 1500° C. is quenched after a few milliseconds by injecting water or oil, i.e. the very rapid cooling to, for example, 90° C. or 220° C. terminates the free-radical chain reaction in the flame
Implementation Method 4
preparing acetylene from hydrocarbons by partial oxidation, cleavage in an arc or pyrolysis of hydrocarbons
Implementation Method 5
cleavage in an arc, cleavage in a plasma or pyrolysis of hydrocarbons or carbon
Data Source
AI summary
A process is proposed for continuously operating a plant for preparing acetylene from hydrocarbons by partial oxidation, cleavage in an arc or pyrolysis of hydrocarbons to obtain a reaction gas mixture which is conducted through one or more compressors, the pressure of the reaction gas mixture on the suction side of the compressor being controlled within a predefined range by means of a conventional controller, which comprises additionally using a higher-level model-supported predictive controller which reacts to abrupt changes in the mass flow rate of the reaction gas mixture.