Fully-automatic ammonia-preparing ammonia-adding integrated machine device and fully-automatic ammonia-preparing ammonia-adding method

Abstract

The invention discloses a fully automatic ammonia-preparing ammonia-adding integrated machine device and a fully automatic ammonia-preparing ammonia-adding method. According to the device and method provided by the invention, when ammonia is automatically prepared, ammonia gas and desalted water are introduced respectively, electrical conductivity and a liquid level signal in an ammonia water solution tank are collected, an ammonia gas electric valve and a desalted water electric valve are controlled by using a PLC to control the electrical conductivity and the liquid level value in the ammonia solution tank to reach a required range, so that stability of a concentration of ammonia water entering a water-vapor system is ensured; and automatic ammonia addition adopts a feedforward compensation PID control method, a condensate water main pipe flow rate is introduced as a feedforward amount, a electrical conductivity value of an inlet of an deaerator is collected at the time, after calculation is performed by the PLC, a frequency converter is used to control an ammonia adding metering pump to ensure that the electrical conductivity of the inlet of the deaerator reaches a desired value, so that automatic adjustment of an addition amount of ammonia is realized.

Description

technical field [0001] The invention relates to the technical field of chemical ammonia addition in the water vapor system of a power plant, in particular to a fully automatic ammonia distribution and ammonia addition integrated machine device and a fully automatic ammonia distribution and ammonia addition method. Background technique [0002] Ammonia is the most commonly used alkalizing agent for metal anticorrosion in thermal systems. Boiler ammonia dosing technology is an important part of the soda water dosing system in power plants, and it is the most economical and practical way to prevent metal corrosion by feed water. By controlling the pH value of the feed water, and the conductivity is a highly reliable signal, there is a conversion formula between the conductivity of the feed water and the pH value, pH=8.57+lgSC, so controlling the conductivity of the feed water can effectively prevent the water supply pipe from Corrosion of the road and damage to the protective f...

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Problems solved by technology

[0003] At present, the power plant is manually operated from the configuration of ammonia water to the water supply ammonia addition system. When distributing ammonia, the purchased concentrated ammonia water is added to the ammonia solution tank according to the proportion, and then the demineralized water is added. Since the concentration of concentrated ammonia water in each batch is different, As a result, the concentration of the ammonia solution in the ammonia solution tank is often changed, so that the amount of ammonia added needs to be changed frequently; at the same time, manual operation is adopted for adding ammonia to the boiler feed water. Adjust the frequency of the metering pump to change the amount of ammonia added, the water quality control index is unstable, and there is a certain amount of equipment corrosion

[0004] Since most power plant units are in peak-shaving operation, the load often changes, so the adjustment of the amount of ammonia added to the water supply in the water vapor system cannot meet the requirements of frequent load changes, resulting in the instability of the pH (conductivity) at the inlet of the deaerator, which not only affects The safety of the unit operation, but also greatly increased the difficulty of the operator's work

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