Combustion chamber includes a primary stage fuel burner to supply fuel into a primary combustion zone and secondary stage fuel burner supplies fuel into a secondary combustion zone. A sensor is positioned downstream from combustion chamber measuring concentration of one or more compounds. The sensor sends measurements of the concentration of compounds to a processor. The processor compares the measured concentration of the compound with a first threshold value and a second threshold value. The processor supplies more fuel to the primary stage fuel burner if the measured concentration is higher than the first threshold value, supplies more fuel to the secondary stage fuel burner if the measured concentration is higher than the second threshold value, maintaining fuel supply to the primary and secondary stage fuel burners if the measured concentration is lower than the first threshold value and lower than the second threshold value.

Aspects of the present disclosure relate generally to a system including: a computing device in communication with a combustion system, wherein the computing device is configured to perform actions including: issuing an input to the combustion system; determining whether one of a dynamic output and an emission output corresponding to the input to the combustion system exceeds a first boundary condition; and adjusting the input to the combustion system by one of a first step change and a second step change; wherein the first step change corresponds to the dynamic output and the emission output not exceeding the first boundary condition, and the second step change corresponds to one of the dynamic output and the emission output exceeding the first boundary condition, the second step change being less than the first step change.

A gas analysis device includes: a measurement part configured to measure an absorption amount of a laser light including an absorption wavelength corresponding to at least two electronic level transitions having the same component contained in the combustion gas, by emitting the laser light on a plurality of measurement paths disposed to pass through the combustion gas; a standard setting part configured to set a standard gas concentration distribution and a standard temperature distribution on the basis of a measurement result of the measurement part; and an analysis part configured to obtain the gas concentration distribution and the temperature distribution by solving a function including the gas concentration distribution and the temperature distribution as variables so as to minimize a difference between the absorption amount measured by the measurement part and a standard absorption amount obtained on the basis of the standard gas concentration distribution and the standard temperature distribution.

A method for operating a furnace includes: providing a furnace comprising feed materials, an oxygen-containing stream, and a fuel-containing stream; providing a virtual sensor including a model generated using inputs including condition data collected by a physical gas sensor previously arranged in the furnace; placing the virtual sensor in communication with the furnace; operating the furnace by a combustion reaction, where during operation of the furnace: the virtual sensor receives the further condition data; in response to receiving the further condition data, the virtual sensor, using the model, determines the combustion product based on the further condition data; and based on the determined combustion product, the virtual sensor sends a signal to the furnace to automatically adjust a flow rate of at least one input.

Systems and methods for reducing NO.sub.x and CO emissions in a natural draft heater are disclosed. For example, the disclosure provides embodiments of systems and methods for controlling a draft value within a heater shell to deliver an amount of excess air to a burner to thereby maintain at least one of NOx emissions not exceeding 0.025 lb/MMBtu (HHV) and CO emissions not exceeding 0.01 lb/MMBtu (HHV) in a natural draft heater.

Systems and methods for reducing NO.sub.x and CO emissions in a natural draft heater are disclosed. For example, the disclosure provides embodiments of systems and methods for controlling a draft value within a heater shell to deliver an amount of excess air to a burner to thereby maintain at least one of NO.sub.x emissions not exceeding 0.025 lb/MMBtu (HHV) and CO emissions not exceeding 0.01 lb/MMBtu (HHV) in a natural draft heater.

A combustion system including a fuel storage stores solid fuel, a supply device connected to the fuel storage, a combustion device combusts supplied solid fuel, and a prediction device for predicting a switching time for types of solid fuel supplied from the fuel storage to the combustion device via the supply device. The prediction device comprises at least one processor configured to acquire a level of solid fuel stored in the fuel storage, predict, as the switching time, a future time when a level obtained by extrapolating time-dependent change in decrease in the level of the solid fuel reaches a threshold value, and display the switching time on a display device.

The combustion system includes an ammonia supply source, a cracker that is connected to the ammonia supply source and that decomposes ammonia into hydrogen and nitrogen, a combustor that is connected to the ammonia supply source and the cracker and that combusts ammonia from the ammonia supply source and gas including hydrogen from the cracker, a sensor that detects a combustion abnormality in the combustor, and a controller that is communicatively connected to the sensor and that adjusts an amount of gas from the cracker to the combustor based on a detection result of the sensor.

Various embodiments of the present technology relate to emission monitoring. Some embodiments comprise an exhaust testing system to characterize exhaust gas composition. The exhaust testing system comprises a sampling system and a gas analyzer. The sampling system is coupled to an exhaust stack of a combustion system. The sampling system comprises a cage, sampling pipes, and valves. The cage is mounted to the opening of the exhaust stack. The sampling pipes are mounted to the cage. The sampling pipes capture exhaust gas generated by the combustion system and emitted through the opening of the exhaust stack. The valves control gas flow through the sampling pipes. The gas analyzer is coupled to the sampling pipes. The gas analyzer determines gas composition of the exhaust gas.

A method for reducing combustion temperature and/or thermal radiation within a lime kiln of a pulp production plant, which kiln is a rotary kiln having a kiln tube (1) internally covered with refractory tiles (13) and having a burner (2) supplied by fuel for heating of the rotary kiln by a flame (3). The effects are achieved by supplying calcium carbonate containing particles to the flame (3) and/or to surrounding area around the flame (3). The particles are supplied into the rotary kiln by at least one lance (9) to the upper part of the flame (3). Calcium oxide containing particles may be supplied to the rotary kiln to areas surrounding the flame (3) for reducing the thermal radiation to an area over the flame (3) and/or to the area at the side of the flame (3), where the refractory tiles (13) of the kiln are rotating downwards.