Hydrogen-nitrogen ratio control method for synthesis ammonia production device

Abstract

The invention discloses a production device of synthesis ammonia. The production device comprises a gas-making furnace control device. The ammonia is generated by the following steps: receiving a total nitrogen-adding air amount Qtn(t) and a total air inlet furnace amount set value Qta(t) output by a hydrogen-nitrogen ratio control device, generating a nitrogen-adding valve air inlet furnace amount Qn(t), an air inlet furnace amount Qh(t) discharged to atmosphere and an air blowing valve air inlet furnace amount Qa(t), entering the gas-making furnace via Qn(t) through the nitrogen-adding valve, entering the gas-making furnace via Qh(t) through an emptying valve and entering the gas-making furnace via Qa(t) through the air blowing valve, and reaching a synthesis tower after passing a transforming-purifying device, wherein Qtn(t)= Qn(t)+Qa(t)-Qh(t); and Qa(t)=Qta(t)-Qn(t). The invention further discloses a hydrogen-nitrogen ratio control method. The total air inlet furnace amount is not affected by the hydrogen-nitrogen ratio control; and the stable production, high yield and energy conservation in the production of ammonia are achieved.

Description

technical field [0001] The invention relates to a synthetic ammonia production device and a hydrogen-nitrogen ratio control method. Background technique [0002] When hydrogen (H2) and nitrogen (N2) are used to synthesize ammonia (NH3), the hydrogen-nitrogen ratio of the raw material gas is required to be 3. The so-called hydrogen-nitrogen ratio control is to adjust the amount of N2 added to make the H2 / N2 in the synthesis tower reached the set value. In my country, coal is mainly used to synthesize ammonia, and the process flow is as follows figure 1 shown. In order to produce qualified raw material gas for synthetic ammonia, the chemical reaction in the coal gasifier will be an endothermic reaction. In order to maintain the furnace temperature, the air gas generated by the air sent by the blower valve must be vented (or partly vented). When venting, the steam valve closure. The existing hydrogen-nitrogen ratio control method is: according to the level of H2 content (or...

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Problems solved by technology

Although the existing hydrogen-nitrogen ratio control process can ensure that the hydrogen-nitrogen ratio is basically qualified, it will lead to changes in furnace temperature and even serious deterioration of furnace conditions. To ensure that the hydrogen-nitrogen ratio is qualified, the amount of air entering the furnace through the nitrogen-adding valve should be increased, which will further lead to an increase in the furnace temperature, which forms a vicious circle, resulting in unstable furnace conditions and unstable hydrogen-nitrogen ratio, which seriously restricts manufacturing. The pursuit of stable, high-yield, and energy-saving production of gas furnaces needs to be improved urgently

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