JPH085011A - Method and device for estimating control of amount of harmful micro constituent - Google Patents

Abstract

PURPOSE:To permit the correct control of a pouring amount by a method wherein the amount of harmful micro constituents in exhaust gas is estimated from the amount of harmful micro constituents in fuel, a reference amount of harmful constituents, which is obtained from the amount of exhaust gas, and the air excessive rate and the like of a fluidized bed combustion device, in a device, in which the amount of harmful micro constituents is controlled by pouring a treating agent into the exhaust gas. CONSTITUTION:The amount of harmful micro constituents in exhaust gas discharged from a fluidized bed combustion device 7 into an high-temperature pipeline for exhaust gas is operated in an operating means 25 from an air excessive rate, the staying time of gas in a fluidized bed 10 and a reference amount of harmful micro constituents. In this case, the air excessive rate is obtained from a solid hydrocarbon fuel supplying amount and an air supplying amount, the staying time of gas in the fluidized bed 10 is obtained from the height of the fluidized bed and the reference amount of harmful micro constituents is obtained from the supplying amount of solid hydrocarbon fuel, a previously analyzed contents of harmful micro constituents and the amount of exhaust gas of combustion. The optimum amount of treating agent against the obtained amount of harmful micro constituents is injected from a treating agent pouring nozzle 1 to reduce the amount of harmful micro constituents discharged out of a chimney.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention predicts and calculates the amount of harmful trace constituents in exhaust gas generated from a fluidized bed combustion apparatus that burns a solid hydrocarbon fuel from the variables related to combustion, and uses the predicted value of the quantity of harmful trace constituents. The present invention relates to a harmful trace component control method and device for injecting and controlling a treating agent in a fluidized bed combustion device.

[0002]

2. Description of the Related Art NH ₃ as a reducing catalyst and a reducing agent is used to control the amount of harmful trace components in exhaust gas generated from a conventional combustion device.
There is a catalytic reduction denitration method that uses a catalyst and a non-catalytic denitration method that injects a reducing agent into a combustion device without using a catalyst. In the catalytic reduction NOx removal method, NOx in the exhaust gas upstream of the position where the reducing agent NH ₃ is supplied is measured with a NOx analyzer, and NO
The supply is controlled so that a predetermined molar ratio is obtained with respect to x. On the other hand, the non-catalytic NOx removal method
NOx is measured by a NOx analyzer, and a reducing agent is controlled and injected so that a predetermined molar ratio to NOx is obtained according to the measured value.

[0003]

However, when the catalyst-free denitration method of the above-mentioned conventional techniques is applied to a pressurized fluidized bed boiler, the following problems occur. In order for NH ₃ to reduce and reduce NOx to the target value, it is necessary to secure the required residence time from its reaction time.To that end, the dust removal equipment installed on the downstream side of the pressurized fluidized bed boiler must be used. It is necessary to inject NH ₃ into the upstream side and allow the reduction reaction to proceed in the high temperature pipe. However, in the above method, since there are scattered particles in the exhaust gas, it is necessary to install some sort of dust remover upstream of the NOx analyzer inlet, and maintenance and inspection of this dust remover is required when operating for a long time. Become. Further, branching from a high temperature pipe connecting the outlet of the pressurized fluidized bed boiler furnace and the dust removing device and providing a sampling port poses a problem in terms of strength of the high temperature pipe having high internal pressure. Therefore, the NOx in the exhaust gas is not measured by the NOx analyzer, and the amount of harmful trace components in the exhaust gas is calculated from the formula consisting of variables such as the fuel supply amount, the air supply amount, and the fluidized bed height that are the control amounts related to combustion. It is desired to inject an optimum amount of the treating agent with respect to this harmful trace amount of component to reduce it to the target harmful trace component amount.

An object of the present invention is to predict and control the amount of harmful trace components in exhaust gas from the variables relating to combustion.

[0005]

SUMMARY OF THE INVENTION The above-mentioned object is to provide a method for controlling a harmful trace amount component by injecting a treating agent into exhaust gas generated by burning the fuel in a fluidized bed combustion device to control the harmful trace amount component. A harmful trace component in the exhaust gas from the amount of the harmful trace component contained and the amount of the reference harmful trace component obtained from the exhaust gas amount, the excess air ratio of the fluidized bed combustion device, and the residence time of the exhaust gas in the fluidized bed. This is achieved by predicting the amount and controlling the injection amount of the treatment agent according to the predicted amount of harmful trace components in the exhaust gas.

The above object is to control the amount of harmful trace components by injecting a treating agent into the exhaust gas generated from a fluidized bed combustion apparatus in which a solid fuel and air are supplied and burned in a fluidized bed in which a fluidized medium flows. In the trace component control method, the supply amount of the solid fuel, a reference harmful trace component amount obtained from the pre-analyzed harmful trace component ratio in the solid fuel and the combustion exhaust gas amount, and the supply amount of the solid fuel and the air The excess air ratio obtained from the supply amount and theoretical air amount, and the gas retention time obtained from the fluidized bed height and the gas velocity in the fluidized bed are used to predict and calculate the amount of harmful trace components in the combustion exhaust gas, This is achieved by controlling the injection amount of the treatment agent according to the predicted trace amount of harmful trace components in the combustion exhaust gas.

The above object is to control the amount of harmful trace components by injecting a treating agent into the exhaust gas generated from a fluidized bed combustion apparatus in which a solid hydrocarbon fuel and air are supplied and burned in a fluidized bed in which a fluidized medium flows. In the control method, the supply amount of the solid hydrocarbon fuel, a reference harmful trace component amount obtained from the pre-analyzed harmful hydrocarbon component ratio in the solid hydrocarbon fuel and the combustion exhaust gas amount, and the solid hydrocarbon fuel The excess amount of air obtained from the supply amount and the supply amount of the air and the theoretical air amount, and the gas retention time obtained from the fluidized bed height and the gas velocity in the fluidized bed, from the amount of harmful trace components in the combustion exhaust gas. Prediction calculation is performed, and injection is performed from a nozzle installed in the exhaust gas duct connected to the fluidized bed combustion device or the nozzle installed in the fluidized bed combustion device according to the amount of harmful trace components in the combustion exhaust gas calculated by the prediction calculation. It is achieved by controlling the injection amount of the treatment agent.

The above object is to provide a harmful trace amount control method for controlling harmful trace components contained in the exhaust gas, in which power is recovered by a gas turbine from the exhaust gas generated by burning fuel in a pressurized fluidized bed apparatus. A treatment agent is injected into the exhaust gas from the pressurized fluidized bed device to control harmful trace components, and the trace amount of harmful trace components is detected on the downstream side of the gas turbine so that the detected trace amount of harmful trace components exceeds the upper limit. In that case, it is achieved by further injecting a treating agent.

The above object is to provide a method for controlling a harmful trace component contained in the exhaust gas, wherein power is recovered from the exhaust gas generated by burning fuel in a pressurized fluidized bed apparatus by a gas turbine. Injecting a treating agent in the exhaust gas from the pressurized fluidized bed apparatus to control harmful trace components, detecting the residual treating agent amount on the downstream side of the gas turbine,
If the amount of the residual treatment agent detected exceeds the upper limit, it is achieved by stopping the injection of the treatment agent.

The above object is achieved when the harmful trace component is NOx and the treating agent is NH ₃ .

The above object is to analyze the amount of supply of the fuel in advance in a harmful trace component control method in which a treating agent is injected into exhaust gas generated by burning fuel in a fluidized bed combustion device to control the amount of harmful trace components. The amount of harmful trace components in the exhaust gas is predicted from the reference amount of harmful trace components contained in the fuel and the exhaust gas amount, and the excess amount of combustion air in the fluidized bed combustor is predicted. This can be achieved by controlling the injection amount of the treatment agent according to the amount of harmful trace components in the exhaust gas.

The above object is achieved when the harmful trace component is SOx and the treating agent is CaCO ₃ .

[0013] The above-mentioned object is to detect a harmful trace component amount for detecting the amount of a harmful trace component contained in an exhaust gas from a fluidized bed combustion apparatus for fluidized combustion of a solid fuel, and a harmful contaminant detected by the harmful trace component amount detecting means. In a harmful trace component control device having a treating agent injection control means for controlling the amount of a treating agent injected into the exhaust gas by the amount of a trace constituent, in place of the harmful trace constituent amount detecting means, a supply amount of the solid fuel, previously analyzed Exhaust gas from the reference harmful trace component amount obtained from the ratio of harmful trace component contained in the fuel and the amount of exhaust gas, the excess air ratio of combustion air in the fluidized bed combustion device, and the residence time of the exhaust gas in the fluidized bed This is achieved by providing a harmful trace component amount predicting means for predicting and calculating the amount of harmful trace component therein.

A treatment agent injection nozzle for injecting the treatment agent is provided in the fluidized bed combustion device or an exhaust gas duct that is connected to the fluidized bed combustion device and guides the exhaust gas to the outside, and the treatment agent injection nozzle of the exhaust gas duct is provided. It is desirable to provide an air injection nozzle that injects air upstream.

The above-mentioned object is a method of predicting a harmful trace component contained in an exhaust gas generated by burning a fuel in a fluidized bed device, wherein the harmful trace component contained in the fuel and the exhaust gas amount are included. Reference harmful trace amount obtained from, and the combustion air excess rate of the fluidized bed combustion device,
This is achieved by predicting the amount of harmful trace components in the exhaust gas from the residence time of the exhaust gas in the fluidized bed.

In a harmful trace component predictor for predicting the amount of harmful trace components contained in the exhaust gas from a fluidized bed combustion apparatus for fluidized combustion of solid fuel, the amount of harmful trace components contained in the fuel and the amount of exhaust gas were determined. A harmful trace component amount predicting means for predicting and calculating the harmful trace component amount in the exhaust gas from the reference harmful trace component amount, the combustion air excess rate of the fluidized bed combustion device, and the residence time of the exhaust gas in the fluidized bed. It is achieved by providing.

[0017]

[Function] Generally, when NOx is a harmful trace component contained in the exhaust gas from the combustion device, the causes are thermal NOx affected by combustion conditions and fuel NOx affected by nitrogen content in fuel. ing. The fluidized bed combustor basically has a small amount of thermal NOx because the combustion temperature is low, but the inventor has found that the fuel NOx is influenced by the excess air ratio and the gas retention time in the fluidized bed in the combustion conditions.

The reason why the amount of NOx generated in the fluidized bed combustion apparatus changes depending on the excess air ratio and the gas retention time in the fluidized bed can be considered as follows. When the excess air ratio increases, the amount of oxygen in the fluidized bed naturally increases, the oxidation reaction of the nitrogen content in the fuel is promoted, and the amount of NOx produced increases. Further, when the excess air ratio becomes high, the proportion of carbon in the fuel that becomes unburned is small, the char concentration in the fluidized bed decreases, the amount of NOx reduction reaction due to char decreases, and the amount of NOx discharged from the fluidized bed decreases. To increase.

The reason why the amount of NOx increases as the gas retention time in the fluidized bed becomes shorter is that the NOx generated in the fluidized bed is increased.
This is because the contact time between char and the char in the fluidized bed is shortened, and the amount of NOx reduction reaction by char is reduced.

In this way, the NOx amount contained in the exhaust gas can be predicted from the reference NOx concentration, the excess air ratio, and the gas retention time. Therefore, the NOx in the exhaust gas is not measured by the NOx analyzer, and the fuel supply which is the combustion control amount is supplied. The amount of NOx in the exhaust gas is predicted from a calculation formula that includes variables such as nitrogen content, air supply amount, and fluidized bed height obtained by analyzing the fuel in advance, and the optimal amount of treatment agent is injected to this NOx amount. By controlling in this way, it is possible to reduce to the target NOx amount.

Further, by injecting air into the exhaust gas duct for guiding the exhaust gas from the fluidized bed combustion device to the outside, the unburned components contained in the exhaust gas are incompletely burned to generate CO and reduce NOx. it can.

The reason why the harmful trace components contained in the exhaust gas from the fluidized bed combustor change depending on the excess air ratio in the case of SOx is that the total exhaust gas increases as the excess air ratio increases.
The ratio of x in the exhaust gas decreases and the SOx concentration decreases. On the other hand, when the excess air ratio decreases, the ratio of SOx in the exhaust gas increases and the SOx concentration increases, so the SOx amount can be predicted from the reference SOx concentration and excess air ratio.

[0023]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a flow chart for explaining the basic configuration of the embodiment of the present invention.

As shown in this figure, the amount of harmful trace components in the exhaust gas discharged from the fluidized bed combustion device 7 to the exhaust gas high temperature pipe 6 is calculated by the calculating means 25 in excess of the air ratio {(actually supplied for combustion. It is calculated from (amount of air) / (amount of air for complete combustion of fuel)}, the gas residence time in the fluidized bed 10 and the amount of reference harmful trace components. Here, the excess air ratio is based on the solid hydrocarbon fuel supply amount and the air supply amount, the gas retention time in the fluidized bed is based on the fluidized bed height, and the reference harmful trace amount is the solid hydrocarbon fuel supply amount and the harmful trace amount component previously analyzed. Calculated from the content rate of the amount and the amount of exhaust gas. For this harmful trace component amount,
An appropriate amount of the treating agent from the treating agent tank 5 is supplied from the treating agent injection nozzle 1 into the exhaust gas high temperature pipe 6 or the fluidized bed combustion device 7.
As a result, the amount of harmful trace components emitted from the chimney 18 is reduced to the target value.

FIG. 2 is a flow chart for explaining the constitution of the embodiment of the present invention.

In this example, NH ₃ in a single-column fluidized bed plant was used.
This is an example of non-catalytic denitration by injection.

At least one NH ₃ injection nozzle 1 is installed in the high temperature exhaust gas pipe 6 installed at the outlet of the fluidized bed boiler furnace. Here, the harmful trace components are nitrogen oxides (hereinafter abbreviated as NOx), and the treating agent is NH ₃ . In this example, NOx and N measured with an analyzer at the feed-forward control using the NOx prediction formula from the fluidized bed and the gas turbine outlet were used.
This is a denitration control method that combines feedback control based on the H ₃ concentration.

First, the denitration control method (feedforward control) using the NOx prediction formula from the fluidized bed will be described.

In the calculation means A, NOx is calculated from the NOx prediction formula.
Then, the amount of reducing agent NH ₃ is calculated at a constant ratio to this amount, and then injected. NOx concentration is predicted by equation (1).

[0031]

[Equation 1]

Where r: excess air ratio, rs: reference excess air ratio,
θs: Standard gas residence time (sec), θ: Gas residence time (sec),
A, B, n: are constants.

The range (1) applicable to the excess air ratio by linear approximation is 1.0 to 1.4, and the excess air ratio may be as high as around 2.0 at the time of start-up according to the formula (1a). Predict.

Predicted NOx concentration (ppm) = reference NOx concentration (ppm) + A ₁ [A ₂ -exp {A ₃ (rs-r)}] + B (θs-θ) ………………………… …………………… (1a) where A ₁ , A ₂ and A ₃ are constants.

The excess air ratio: r is calculated from the fuel supply amount (kg / h) and the combustion air amount (kg / h) from the equation (2) in the calculating means B.

Excess air ratio: r (-) = [combustion air amount (kg / h) / {fuel supply amount (kg / h) × theoretical air amount (Nm ³ /kg·cwp)×1.293(kg/Nm ³ )}] × Combustion efficiency (%) / 100) ……………………………………… (2) Gfw1 (s) and Gfw2 (s) are transfer functions of combustion air quantity and fuel, respectively. It is for compensating the dynamic characteristics of the supply amount.

The gas retention time: θ (sec) is the fluidized bed height (m) obtained by the calculation means C from the equation (3) and the gas retention time in the fluidized bed: θ (sec) is obtained from the indicated value of the differential pressure gauge. And the gas velocity (m / sec) in the fluidized bed.

Gas retention time in fluidized bed: θ (sec) = {fluidized bed height (m)} / gas velocity in fluidized bed (m / sec)} ………………………… (3) Here, the gas velocity (m / sec) in the fluidized bed is calculated from Eq. (4) by the amount of combustion air (kg / h), the internal cross-sectional area of the fluidized bed combustor (m ² ), the internal temperature of the fluidized bed (° C). Calculate from

Fluidized bed gas velocity (m / sec) = C {combustion air amount (kg / h)} × 1.293 (kg / Nm ³ ) / 3600 × {fluidized bed temperature (° C.) + 273} / {standard Temperature 0 (℃) +273} / {Fluidized bed combustor internal cross-sectional area (m ² )} ……………… (4) where C is a constant.

The standard NOx concentration is the nitrogen content (mg / kg) in the coal and the higher calorific value (kcal / k) of the coal obtained in advance by analysis from the equation (5).
g), total nitrogen ratio in coal (wt%), fuel supply amount (kg / h), exhaust gas amount (kg / h).

[0041]

[Equation 2]

Here, E and m are constants, and the rate at which the nitrogen content in the coal is converted to NOx is determined by m. The NH ₃ injection nozzle 1 installed in the high temperature exhaust gas pipe 6 is controlled so that the amount of NH ₃ calculated by the equation (6) can be supplied.

Injected NH ₃ amount (kg / h) = F (set NH ₃ / NO molar ratio) × {predicted NOx concentration (ppm)} (6) Here, F is a constant.

In feedback control, NOx analyzer A
The output of X-1, NH ₃ analyzer AX-2 works to cancel the deviation of feedforward control. Specifically, NOx analyzer AX-1
The amount of NOx was measured in the above, and if this value exceeds the upper limit, a reducing agent is further injected, and the residual NH ₃ concentration is measured in the NH ₃ analyzer AX-2. If so, control to stop the NH ₃ injection. A catalytic denitration device 17 is installed downstream of the gas turbine 15 to further reduce Nox up to the inlet of the chimney 18. Since the gas turbine 15 is not equipped with a combustor, NOx is not generated here.

When a plurality of fluidized bed boilers 7 are installed, at least one NH ₃ injection nozzle 1 is installed in the high temperature exhaust gas pipe 6 installed at each fluidized bed boiler furnace outlet.

FIG. 3 is a table for explaining the relationship between the excess air ratio, the gas retention time in the fluidized bed and the NOx concentration in the embodiment of the present invention.

In the figure, the horizontal axis shows the excess air ratio, the vertical axis shows the NOx concentration, and the gas retention time is shown as a parameter. Each line is
The calculated values of the gas retention time obtained from the prediction formula (1) are circles, and the circles are the measured values for the retention times of 2 seconds and 4 seconds. The NOx concentration increases as the excess air ratio increases and as the residence time decreases. Comparing the measured value with the calculated value, both values agree within 10%, so the NOx concentration can be clearly predicted from the equation (1). FIG. 4 is a chart for explaining the relationship between the molar ratio and the NOx reduction rate in the example of the present invention. Figure 2
It is data of non-catalytic denitration by NH ₃ injection in the fluidized bed plant shown in. The horizontal axis is (NH ₃ moles / (NO moles), the vertical axis is N
Indicates the Ox reduction rate. If this value increases, NOx in exhaust gas
The quantity will be smaller. Also, in order to increase this value, the amount of NH ₃ supplied increases. The higher the in-furnace temperature, that is, the reaction temperature, the higher the NOx reduction rate. The value indicated by the broken line is the target value, and it is necessary to control the NH ₃ injection amount so as to achieve this target value.

FIG. 5 is a flow chart for explaining the configuration of another embodiment of the present invention.

This example shows CaCO in a single-column fluidized bed plant.
_{3 This} is an example of desulfurization by injection.

Here, harmful trace components are sulfur oxides (hereinafter S
(Abbreviated as Ox), the treating agent becomes CaCO ₃ . The present embodiment is a desulfurization control method that combines feedforward control using the SO ₂ predictive equation from the fluidized bed and feedback control based on the SO ₂ concentration measured by an analyzer at the gas turbine outlet. First, desulfurization control method using SOx prediction formula from fluidized bed
(Feedforward control) will be described. Computing means
In A, the SO ₂ amount was calculated from the SO ₂ prediction formula, and the CaCO ₃ supply amount from the desulfurizing agent bunker 27 was adjusted so that (Ca mole number) / (S mole number) would be the optimum value for this amount. It is controlled by the feeder 28.

The SO ₂ concentration is predicted by the equation (7).

Predicted SO ₂ concentration (ppm) = reference SO ₂ concentration (ppm) -G · exp (H · r) …………………… (7) where r: excess air ratio, G, H: It is a constant.

The excess air ratio: r is calculated from the fuel supply amount and the combustion air amount (kg / h) from the equation (8). Air excess ratio: r (-) = [combustion air amount (kg / h) / {fuel supply amount (kg / h) × theoretical air amount (Nm ³ / kg ・ cwp) × 1.293 (kg / Nm ³ )} ] × Combustion efficiency (%) / 100 ……… (8) The standard SO ₂ concentration is calculated from Eq. (9) as fuel supply amount (kg / h), total sulfur content in coal (wt%), exhaust gas amount (kg /). Calculate from h).

Standard SO ₂ concentration (pppm) = I {fuel supply amount (kg / h)} × {total sulfur ratio in coal (wt%) / 100} / exhaust gas amount (kg / h) ……………… ……………… (9) where I is a constant.

In feedback control, SO ₂ analyzer A
The output of X-1 acts to cancel the deviation of the feedforward control. Specifically, the SO ₂ concentration is measured by the SO ₂ analyzer AX-1, and the amount of SO ₂ is determined. If this value exceeds the upper limit, the desulfurizing agent CaCO ₃ is further supplied. FIG. 6 is a flowchart explaining the configuration of another embodiment of the present invention.

This example is for a single-column fluidized bed plant.
NH ₃ in the exhaust-gas upstream side of the NH ₃ injection nozzle 1 of the uncatalyzed denitration by injection is an example of the air nozzle 24 is installed. In a basic test, it has been confirmed that in the NO-NH ₃ -O ₂ denitration reaction, the coexistence of CO (carbon monoxide) enhances the denitration performance even in the low temperature region around 750 ° C. In the present embodiment, this CO coexistence effect is utilized.
Since a large amount of char that does not burn and scatters in the fluidized bed at low load, air is supplied from the air nozzle 24 installed at the furnace outlet, where char is incompletely burned to generate CO, and after NH ₃ injection In the NO reduction region of, the NOx removal reaction effectively proceeds even at low load (exhaust gas temperature near 750 ° C). The operation of supplying air from the air nozzle 24 to generate CO is performed especially when the exhaust gas temperature is low and the boiler load is about 50%. Control of non-catalytic denitration is carried out by the same method as in the first embodiment.

FIG. 7 is a flow chart for explaining the configuration of another embodiment of the present invention.

The present embodiment is an example in which a high temperature denitration catalyst is used instead of the non-catalytic denitration in a single-column fluidized bed plant. At the rated load, the inlet temperature of the gas turbine 15 is about 850 ° C., and the catalyst needs to be able to withstand this temperature. The present embodiment is a denitration control method that combines feedforward control using a NOx prediction formula from a fluidized bed and feedback control based on NOx and NH ₃ concentrations measured by an analyzer at a chimney inlet.

In the feedforward control, the calculation formulas in the calculating means A, B and C are the same as those explained in the first embodiment. In this embodiment, NH ₃ supplied to the high temperature catalyst
The reducing agent amount such as is supplied at a constant ratio to the NOx amount calculated by the calculating means A. In feedback control, NOx analyzers AX-1 and NH ₃ installed at the outlet of the high temperature denitration catalyst
The output of the analyzer AX-2 works to cancel the deviation of the feedforward control. Specifically, in the NOx analyzer AX-1, N
Ox amount is measured, if this value exceeds the upper limit, further reducing agent is injected, and NH ₃ concentration is measured by NH ₃ analyzer AX-2, and if this value exceeds the upper limit. It controls to stop the injection of NH ₃ .

[0060]

According to the present invention, the amount of harmful trace constituents contained in the exhaust gas can be predicted from the excess air ratio and the gas retention time of the fluidized bed combustion apparatus, so that it is possible to measure the amount of harmful trace constituents in the exhaust gas. By predicting the amount of harmful trace components in the exhaust gas from the calculation formula that includes variables such as the fuel supply amount and the harmful trace component ratio, the air supply amount, and the fluidized bed height, and controlling to inject the optimum amount of treatment agent, the target It has the effect of reducing the amount of harmful trace components.

[Brief description of drawings]

FIG. 1 is a flowchart illustrating a basic configuration of an exemplary embodiment of the present invention.

FIG. 2 is a flowchart illustrating a configuration of an exemplary embodiment of the present invention.

FIG. 3 is a table for explaining the relationship between the excess air ratio, the gas retention time in the fluidized bed, and the NOx concentration in the example of the present invention.

FIG. 4 is a chart illustrating the relationship between the molar ratio and the NOx reduction rate in the example of the present invention.

FIG. 5 is a flowchart illustrating the configuration of another embodiment of the present invention.

FIG. 6 is a flowchart illustrating the configuration of another embodiment of the present invention.

FIG. 7 is a flowchart illustrating the configuration of another embodiment of the present invention.

[Explanation of symbols]

1 Treatment Agent Injection Nozzle 2 Fuel Supply Nozzle 3 Combustion Air Duct 4 Differential Pressure Meter 5 Treatment Agent Tank 6 High Temperature Pipe for Exhaust Gas 7 Fluidized Bed Boiler 8 Combustion Air Windbox 9 Dispersion Plate 10 Fluidized Bed 11 Cyclone 12 Ceramic Filter 13 Gas Turbine Inlet duct 14 Compressor 15 Gas turbine 16 Generator 17 High temperature catalytic denitration device 18 Chimney 19 Mixer 20 NH ₃ Diluting air supply pipe 21 NH ₃ Diluting air supply adjusting valve 22 Heat transfer pipe 23 NH ₃ supplying adjusting valve 24 Air Nozzle 25 Computing means 26 Monitor for monitoring 27 Desulfurizing agent bunker 28 Feeder

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification number Reference number in the agency FI Technical indication location F23N 5/00 ZAB J Y (72) Inventor Niichi Tomuro 7-1, Omika-cho, Hitachi-shi, Ibaraki Hitachi, Ltd. Hitachi Research Laboratory (72) Inventor Toru Inada 1-1-1, Omika-cho, Hitachi City, Ibaraki Prefecture Hitachi Ltd. Hitachi Research Laboratory (72) Inventor Nobuyuki Hokari Omika-machi, Hitachi City, Ibaraki Prefecture 7-1-1, Hitachi Ltd. Hitachi Research Laboratory (72) Inventor Katsuya Oki 6-9 Takaracho, Kure-shi, Hiroshima Babcock Hitachi Kure Factory

Claims (13)

[Claims] 1. A method for controlling a harmful trace amount of a trace amount by injecting a treating agent into an exhaust gas generated by burning a fuel in a fluidized bed combustion device to control the amount of a trace amount of the harmful trace component, The amount of reference harmful trace components obtained from the amount of exhaust gas, the excess air ratio of the fluidized bed combustion device, and the amount of harmful trace components in the exhaust gas from the residence time of the exhaust gas in the fluidized bed, and the predicted A method for controlling the amount of harmful trace components, which comprises controlling the injection amount of the treatment agent according to the amount of harmful trace components in the exhaust gas. 2. A harmful trace component for controlling the amount of a harmful trace component by injecting a treating agent into an exhaust gas generated from a fluidized bed combustion apparatus in which a solid fuel and air are supplied and burned in a fluidized bed in which a fluid medium flows. In the control method, a supply amount of the solid fuel, a reference harmful trace component amount obtained from a pre-analyzed harmful trace component ratio in the solid fuel and the combustion exhaust gas amount, a supply amount of the solid fuel, and an air supply Amount and theoretical air amount, the excess air ratio, and the gas retention time obtained from the fluidized bed height and the gas velocity in the fluidized bed are used to predictively calculate the amount of harmful trace components in the combustion exhaust gas. A method for controlling the amount of harmful trace components, which comprises controlling the injection amount of the treating agent according to the amount of harmful trace components in the burned exhaust gas. 3. A control for injecting a treating agent into an exhaust gas generated from a fluidized bed combustion apparatus in which a solid hydrocarbon fuel and air are supplied and burned in a fluidized bed in which a fluidized medium flows to control a harmful trace amount of components. In the method, a supply amount of the solid hydrocarbon fuel, a reference harmful trace component amount obtained from a pre-analyzed harmful trace component ratio in the solid hydrocarbon fuel and the combustion exhaust gas amount, and a supply amount of the solid hydrocarbon fuel And an excess air ratio obtained from the air supply amount and the theoretical air amount,
The amount of harmful trace components in the combustion exhaust gas is predicted from the fluidized bed height and the gas residence time obtained from the gas velocity in the fluidized bed, and the flow is calculated according to the predicted amount of harmful trace components in the combustion exhaust gas. A method for controlling a harmful trace amount of a component, which comprises controlling an injection amount of the processing agent injected from a nozzle installed in an exhaust gas duct connected to a bed combustion device or in a fluidized bed combustion device. 4. A method for controlling a harmful trace component contained in the exhaust gas, wherein power is recovered from the exhaust gas generated by burning a fuel in a pressurized fluidized bed device by a gas turbine, and the pressurization is performed in the control method. Injecting a treatment agent into the exhaust gas from the fluidized bed equipment to control harmful trace components, detect the amount of harmful trace components on the downstream side of the gas turbine, and detect that the detected amount of harmful trace components exceeds the upper limit. A method for controlling the amount of harmful trace components, which further comprises injecting a treating agent. 5. A method for controlling a harmful trace amount contained in the exhaust gas, wherein power is recovered from the exhaust gas generated by burning fuel in a pressurized fluidized bed apparatus by a gas turbine, and the pressurization is performed in the control method. If a treating agent is injected into the exhaust gas from the fluidized bed apparatus to control harmful trace components, the residual treating agent amount is detected on the downstream side of the gas turbine, and the detected residual treating agent amount exceeds the upper limit. A method for controlling the amount of harmful minor constituents, which comprises stopping the injection of the treatment agent. 6. The harmful trace amount component control according to claim 1, wherein the harmful trace component is NOx and the treating agent is NH _3. Method. 7. A harmful trace component control method for controlling a harmful trace component amount by injecting a treatment agent into an exhaust gas generated by burning a fuel in a fluidized bed combustion device, the supply amount of the fuel comprising:
Predicting the harmful trace component amount in the exhaust gas from the reference harmful trace component amount obtained from the pre-analyzed ratio of the harmful trace component contained in the fuel and the exhaust gas amount, and the combustion air excess rate of the fluidized bed combustion device, A method for controlling harmful trace constituents, which comprises controlling the injection amount of the treating agent according to the predicted amount of harmful trace constituents in the exhaust gas. 8. The method for controlling the amount of harmful trace constituents according to claim 7, wherein the harmful trace constituents are SOx and the treating agent is CaCO ₃ . 9. A harmful trace component amount detecting means for detecting the amount of harmful trace component contained in exhaust gas from a fluidized bed combustion apparatus for fluidized combustion of solid fuel, and a harmful trace component detected by the harmful trace component amount detecting means. In the harmful trace ingredient control device having a treating agent injection control means for controlling the amount of the treating agent injected into the exhaust gas by the amount, instead of the harmful trace ingredient amount detecting means, the supply amount of the solid fuel, the previously analyzed In the exhaust gas from the reference harmful trace component amount obtained from the ratio of the harmful trace component contained in the fuel and the exhaust gas amount, the combustion air excess rate of the fluidized bed combustion device, and the residence time in the fluidized bed of the exhaust gas. A harmful trace component control device comprising a harmful trace component amount prediction means for predicting and calculating a harmful trace component amount. 10. A treatment agent injection nozzle for injecting the treatment agent is provided in the fluidized bed combustion device or an exhaust gas duct that is connected to the fluidized bed combustion device and guides the exhaust gas to the outside.
The harmful trace component control device according to claim 9, wherein an air injection nozzle for injecting air is provided upstream of the treatment agent injection nozzle of the exhaust gas duct. 11. The harmful trace component amount control device according to claim 9, wherein the harmful trace component is NOx and the treating agent is NH ₃ . 12. A method for predicting a harmful trace component contained in an exhaust gas generated by burning a fuel in a fluidized bed apparatus, wherein the harmful trace component contained in the fuel and the exhaust gas amount are obtained. Harmful harmful trace amount in the exhaust gas from the reference harmful trace amount, the combustion air excess rate of the fluidized bed combustion device, and the residence time of the exhaust gas in the fluidized bed Component prediction method. 13. A harmful trace component predictor for predicting a harmful trace component amount contained in an exhaust gas from a fluidized bed combustion device for fluidized combustion of a solid fuel, comprising: measuring a harmful trace component component contained in the fuel and the exhaust gas amount; Amount of reference harmful trace components obtained, combustion air excess rate of the fluidized bed combustion device,
A harmful trace component predicting apparatus comprising a harmful trace component predicting means for predicting and calculating a harmful trace component amount in the exhaust gas from a residence time of the exhaust gas in a fluidized bed.