Urea hydrolysis reactor control system and urea hydrolysis reactor control method based on heat feed-forward signals

Abstract

The invention relates to a urea hydrolysis reactor control method based on the heat feed-forward signals, which comprises the steps of 1) acquiring a transfer function from a hydrolysis rector load to heating steam consumption; 2) generating a path of heating steam consumption signals through the transfer function by a hydrolysis rector load instruction, and converting the heating steam consumption signals into corresponding first heating steam governing valve openness signals; 3) generating second heating steam governing valve openness signals through a governing valve openness control function by a hydrolysis rector pressure deviation signals, and acquiring a deviation value; 4) leading the first heating steam governing valve openness signals into heating steam governing valve openness automatic control logic to act as feed-forward signals, and determining an openness reference value; and 5) weighing the heating steam governing valve openness reference value and the deviation value, outputting the weighed heating steam governing valve openness reference value and the weighed deviation value so as to acquire heating steam governing valve openness signals under variable load conditions. The control system provided by the invention comprises a PLC (programmable logic controller) which is used for receiving the hydrolysis reactor load instruction, a hydrolysis reactor pressure set value and measurement signals.

Description

technical field [0001] The invention relates to a technology for producing ammonia by urea hydrolysis for denitrification in a thermal power plant, in particular to a control system and method for a urea hydrolysis reactor based on a heat feedforward signal. Background technique [0002] In recent years, domestic and foreign power generation companies have paid more and more attention to the potential dangers in the use of liquid ammonia. In some special areas and coal-fired power plants that are close to cities and residential areas, urea hydrolysis to ammonia has become an important method for the preparation of SCR denitrification and reduction. The recommended process for the agent. [0003] The urea hydrolysis ammonia production process has been gradually applied in the SCR denitrification reducing agent preparation section of thermal power plants. Ammonia production system; CN202430017U, a urea hydrolyzer applied to flue gas denitrification; CN201458752U; urea hydroly...

AI Technical Summary

Problems solved by technology

Due to the large size of the hydrolysis reactor and a large amount of high-temperature urea solution stored in the container, the working temperature of the hydrolysis reactor changes slowly under the action of thermal inertia, coupled with the heat conduction process of the heating steam, from the gas phase outlet valve action to the heating steam valve action The elapsed time will be very long, the response speed of the hydrolysis reactor to the load changing command is very slow, the steam valve moves frequently during the load changing process, and the heat waste is very serious

On the other hand, the shutdown process of the urea hydrolysis plant is relatively slow. When the ammonia gas supply needs to be cut off quickly due to a fault in the SCR area, how to control the emergency shutdown of the urea hydrolysis plant is also an urgent problem to be solved.

Images