On-line detection device and method for gas-liquid transfer method escaping ammonia

Abstract

The invention discloses an on-line detection device and method for gas-liquid transfer method escaping ammonia. The online detection device comprises a fluid flowmeter, an absorption liquid supply system, a smoke dust filter, a liquid membrane heat absorption tube, a gas-liquid first-stage separator, a flow-through tank, a measurement control system, a water quality ammonia nitrogen sensor used for detecting the concentration of NH4<+> contained in absorption liquid in the flow-through tank, and a liquid density sensor used for detecting density of liquid in the flow-through tank. The on-line detection device and method can accurately detect the concentration of escaping ammonia online.

Description

technical field [0001] The invention relates to an on-line detection device and method, in particular to an on-line detection device and method for escaped ammonia by a gas-liquid transfer method. Background technique [0002] At present, my country's flue gas denitrification devices in thermal power plants based on SCR and SNCR processes have generally begun to be put into operation. The size of escaped ammonia (unreacted ammonia concentration in flue gas) at the outlet of SCR and SNCR devices is crucial to the safe operation of downstream equipment. SCR devices are usually required to be controlled within 3 μL / L, and SNCR is usually required to be controlled within 10 μL / L within. Since changes in flue gas conditions and catalyst activity during operation will affect the amount of slipped ammonia, in order to ensure the safe operation of downstream equipment, the outlets of existing SNCR and SCR devices are equipped with online slipped ammonia detection devices, so that o...

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Problems solved by technology

[0003] However, the actual operation of the existing online ammonia escape monitoring device cannot meet the monitoring requirements, and in the best case, it can only reflect the trend and cannot provide the required detection accuracy

The measurement principle of these devices is the in-situ laser method. The main source of the problem is: because the absorption spectrum of NH3 is close to that of H2O, the interference of water is difficult to eliminate; the in-situ installation method is inevitably affected by the dust content in the flue gas; the emission and The receiving sensor is installed on the flue. Due to the expansion or contraction of the flue due to changes in temperature, the deviation of the light cannot be avoided.

However, during the operation of the power plant, steam soot blowing and load lifting will cause large changes in flue gas moisture, ash concentration, and flue gas temperature. In principle, there are insurmountable difficulties

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