Controlling the injection of ammonia in a dry type exhaust gas denitration process

Patent · Tue Feb 02 00:00:00 EST 1982

OSTI ID:5199302

Shiraishi, Y; Ukawa, N

In a first processor unit the relationship between the amount of nitrogen oxides in a combustion exhaust gas and a numerical value representing an amount of combustion, E.G. - fuel flow rate or the like, is stored. In a second processor unit the ratio of ammonia to nitrogen oxides as a function of the combustion exhaust gas temperature is stored. A numerical value corresponding to the actual measured amount of combustion is inputted to the first processor unit to derive the amount of nitrogen oxides in the combustion exhaust gas. The actual measured combustion exhaust gas temperature is inputted to the second processor unit to derive the ratio of ammonia to nitrogen oxides. The optimum amount of ammonia to be injected is derived by multiplying the amount of nitrogen oxides, derived by means of the first processor unit, by the ratio of ammonia to nitrogen oxides derived by means of the second processor unit. In a preferable embodiment of the present invention, the ratio of ammonia to nitrogen oxides is corrected before the multiplication by means of a correction factor which is stored in a third processor unit and which corresponds to a time variation rate of the combustion exhaust gas temperature.

• Assignee: Mitsubishi Jukogyo K K (Japan)
• Patent Number(s): US 4314345
• OSTI ID: 5199302
• Resource Relation: Patent Priority Date: Priority date 23 Jan 1978, Japan; Other Information: PAT-APPL-172853
• Country of Publication: United States
• Language: English

Related Subjects

20 FOSSIL-FUELED POWER PLANTS
DENITRATION
AMMONIA
CONTROL
EXHAUST GASES
AIR POLLUTION CONTROL
COMBUSTION
DECOMPOSITION
INJECTION
NITROGEN OXIDES
CHALCOGENIDES
CHEMICAL REACTIONS
FLUIDS
GASEOUS WASTES
GASES
HYDRIDES
HYDROGEN COMPOUNDS
INTAKE
NITROGEN COMPOUNDS
NITROGEN HYDRIDES
OXIDATION
OXIDES
OXYGEN COMPOUNDS
POLLUTION CONTROL
THERMOCHEMICAL PROCESSES
WASTES
200202* - Fossil-Fueled Power Plants- Waste Management- Noxious Gas & Particulate Emissions