A method for automatic switching control of water hydrolysis reactor in ammonia production system

Abstract

The invention discloses a control method for automatic switching of hydrolysis reactors in an ammonia production system, which preheats the second reactor and controls the pressure of the second reactor to ensure that the pressure of the second reactor is stable and completes the process before switching the second reactor. Preheating preparation; continue to adjust the temperature of the second reactor to the first preset temperature value, and control the urea flow rate with the second preset flow value matched with the minimum ammonia demand to reduce switching fluctuations. When the temperature, pressure and urea flow rate are respectively within the preset deviation range, the second reactor and the first reactor are respectively controlled to increase or decrease the load in a preset way until the urea flow rate of the first reactor meets the requirements, and the switching is completed. The fluctuation of process switching is small, and the pressure of the main pipe of ammonia gas is effectively controlled to be stable, so that the output of ammonia gas meets the requirements of the boiler, preventing excessive discharge of NOX in the boiler system and excessive leakage of ammonia gas; the production conditions are continuously stable, reducing the workload of operators and improving production efficiency , to ensure safe production.

Description

technical field [0001] The invention relates to the technical field of automatic control of a hydrolysis reaction system, in particular to an automatic switching control method of a hydrolysis reactor in an ammonia production system. Background technique [0002] As people's awareness of the safety of liquid ammonia is getting deeper and deeper, more and more countries have begun to use urea as a source of NH3. The United States and Europe have begun to use urea as an indirect denitrification reducing agent in large quantities since the 1990s. [0003] Urea and water can produce a mixture of ammonia and CO2 at a certain temperature and pressure, and this reaction is an endothermic reaction. The urea hydrolysis reaction can reach different chemical equilibrium states at different temperatures and pressures. Generally, this reaction is carried out at 150°C to 300°C. Under this temperature and normal pressure, the chemical reaction speed of urea hydrolysis is very slow, and it...

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Problems solved by technology

[0008] In view of this, the purpose of the present invention is to provide a method for automatic switching control of the hydrolysis reactor in the ammonia production system, to solve the problem that the existing hydrolysis reactor switching control is generally manually operated, and the stable production of ammonia cannot be controlled, resulting in excessive ammonia gas. row and so on

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