Stabilisation of the methanol synthesis cycle based on algorithmic control of the cooling and condensation unit
DOI:
https://doi.org/10.33216/1998-7927-2025-296-10-61-68Keywords:
methanol synthesis, air cooling devices, condensation, automation, discrete control, disturbance compensationAbstract
The paper investigates the influence of the operating modes of the gas-product mixture cooling and condensation unit on the stability and economic efficiency of the methanol synthesis cycle. It is shown that uncoordinated control of air cooling devices, which is mainly implemented in manual mode, leads to significant temperature and hydraulic disturbances in the synthesis circulation circuit. This, in turn, causes fluctuations in synthesis gas consumption, changes in pressure drops at the compressor, and a decrease in the overall stability of the unit. Existing approaches to regulating heat exchange processes, in particular the use of frequency converters to control air cooling unit fans, have been analysed, and their limited effectiveness and high cost for existing production facilities have been substantiated. An alternative approach to the automation of the cooling and condensation unit is proposed, based on the principle of compensation for disturbances in the input parameters of the process. The essence of the approach lies in the use of a discrete control system with algorithmic selection of the optimal combination of operating air cooling devices, taking into account the temperature of the gas-product mixture at the unit inlet, its flow rate and the ambient temperature. This approach minimises temperature jumps at the unit outlet, reduces pressure drops and ensures a smoother transition in the methanol synthesis cycle. The advantage of the proposed solution is that it can be implemented without installing additional expensive equipment, using only existing automation and control systems. The results obtained can be used to improve the reliability and energy efficiency of existing methanol synthesis units.
The implementation of the proposed approach creates the conditions for the further integration of intelligent control methods and digital twins of technological processes, which is in line with current trends in the development of the chemical industry and the Industry 4.0 concept.
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