JP2017026448A - Method and device for estimating temperature in furnace - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method and device for estimating a temperature in a furnace, capable of stably, reliably estimating a temperature in the furnace for a long time without depending on the variation of the thickness of a slag coating layer.SOLUTION: A temperature in the furnace of a reactor covered with a slag coating layer is calculated by the following formula (1). T=T+(T-T)+K(T)×ΔT... (1), where in the formula (1), Tis a temperature estimation value in the furnace; Tis a temperature measurement value in the inside of a furnace wall, K (T) is a correction coefficient corresponding to T; ΔTis a variation value of the temperature measurement value in the inside of the furnace wall; Tis a temperature initial value in the furnace being a measurement value of the temperature in the furnace measured when the method for estimating the temperature in the furnace is started; and Tis a temperature initial value in the inside of the furnace wall being a temperature measurement value in the inside of the furnace wall measured when the method for estimating the temperature in the furnace is started.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a method for estimating an in-furnace temperature of a reactor whose inner surface is covered with a slag coating layer, and an in-furnace temperature estimating apparatus.

  Solid hydrocarbon fuel (hereinafter, simply referred to as “fuel”) such as coal (coke), biomass, and industrial wastes obtained by pyrolyzing industrial waste (hereinafter simply referred to as “fuel”) at high temperatures (approximately 1300 ° C. to 1600 ° C.) In a reaction furnace such as a gasification furnace for gasification or a combustion furnace for burning fuel, the temperature in the reaction furnace needs to be measured and optimally controlled so that the reaction proceeds appropriately. One such reactor is a coal gasifier.

  In the case of a coal gasification furnace, ash contained in the fuel melts in the furnace and flows down along the wall to form a slag coating layer for protecting the furnace wall. In addition, the ash content is melted and separated and removed from the product gas in the reaction furnace, thereby preventing adverse effects on the downstream gas purification equipment disposed downstream of the reaction furnace.

  Here, if the temperature in the gasification furnace is not stably maintained within an appropriate range, the thickness of the formed slag coating layer may increase or decrease or disappear, and the furnace wall of the reactor may be damaged. is there. Further, if the temperature in the gasification furnace is not stably maintained in an appropriate range, the slag discharge port at the lower part of the gasification furnace may be clogged. Therefore, in order to keep the slag flow down normally, it is very important to control the furnace temperature.

  The temperature range to be measured and controlled here is approximately 1300 ° C to 1600 ° C. Conventionally, thermocouples are most commonly used as such temperature measuring means. Further, when used at such a high temperature, the thermocouple is inserted into a protective tube made of an iridium alloy or the like.

  As a means for measuring the temperature other than the thermocouple, for example, a radiation thermometer using a reaction field flame or radiant energy of a high temperature gas is used. The radiation thermometer measures the temperature by measuring the wavelength and brightness of light through a transparent viewing window (usually made of glass) provided in the reaction furnace.

  In addition, in Patent Document 1, based on the temperature measured by a plurality of thermocouples installed at different positions in the axial direction of the outlet of the blast furnace, the thermal conductivity of the outlet mud and the like is taken into consideration and the hot metal in the blast furnace A technique for estimating temperature is disclosed.

JP 2007-78475 A

As described above, the temperature in a reaction furnace such as a gasification furnace or a combustion furnace is very high (approximately 1300 ° C. to 1600 ° C.). For this reason, when the protection tube of the thermocouple is used, it is corroded and damaged by the gas in the use environment and the molten ash peculiar to the solid fuel.
As a result, even the thermocouple strands are damaged, and there is a problem that they cannot be used for a long time.

On the other hand, when a radiation thermometer is used, there is a problem that an accurate temperature cannot be measured because a transparent observation window provided in the reaction furnace is contaminated by molten ash or dust in the reaction furnace.
When a radiation thermometer is used, a gas that blows off the deposits attached to the transparent viewing window is circulated, but it is difficult to always keep it clean for a long time.
That is, with the conventional method, it has been difficult to accurately and accurately measure the temperature in the reactor for a long period of time.

Moreover, when forming the slag coating layer by molten ash on the inner wall of a reaction furnace like a coal gasification furnace, the heat conductivity between the inside of a reaction furnace and a thermocouple changes.
For this reason, when the technique disclosed in Patent Document 1 is used, since the thermal conductivity is included in the temperature estimation equation in the reactor, the reliability of the estimated temperature in the furnace is reduced when the thermal conductivity changes. There was a risk of decline.

  Therefore, the present invention provides an in-furnace temperature estimation method capable of stably and reliably estimating the in-furnace temperature for a long time without depending on the change in the thickness of the slag coating layer, and the in-furnace temperature. An object is to provide an estimation device.

In order to solve the above-described problem, according to one aspect of the present invention, an in-furnace temperature for estimating an in-furnace temperature, which is a temperature of a space defined by the slag coating layer of a reactor whose inner surface is covered with a slag coating layer. An estimation method, wherein a first thermocouple partially disposed inside a furnace wall constituting the reaction furnace is used to continuously measure a temperature inside the furnace wall, which is a temperature inside the furnace wall. A furnace wall internal temperature measurement step, and a furnace wall internal temperature measurement value that is a difference obtained by subtracting the furnace wall internal temperature measurement value of a predetermined time from the current furnace wall internal temperature measurement value A wall internal temperature change value calculation step and a correction coefficient for converting the furnace wall internal temperature change value into a change value in the furnace temperature, wherein the correction coefficient is inversely proportional to the furnace wall internal temperature measurement value. Based on the measured temperature inside the furnace wall. A correction coefficient calculation step for calculating the correction coefficient, a term of a value obtained by multiplying the furnace wall internal temperature change value by the correction coefficient, and a term of the furnace wall internal temperature measurement value, Based on the furnace temperature estimation step of calculating the furnace temperature estimated value,
An in-furnace temperature estimation method is provided.
T ₄ = T ₂ + (T ₄₀ −T ₂₀ ) + K (T ₂ ) × ΔT ₂ (1)
Here, in the above formula (1), T ₄ is the furnace temperature estimated value, T ₂ is the furnace wall internal temperature measurement value, K (T ₂ ) is the correction coefficient corresponding to T ₂ , and ΔT ₂ is the above The change value of the measured temperature inside the furnace wall, T ₄₀ is the initial value of the furnace temperature that is the measured value of the furnace temperature measured at the start of the furnace temperature estimation method, and T ₂₀ is the value of the furnace temperature estimation method. The furnace wall internal temperature initial value, which is the furnace wall internal temperature measurement value measured at the start, is shown.

  According to the in-furnace temperature estimation method of the present invention, the in-furnace temperature can be estimated by continuously measuring the temperature inside the furnace wall, which is a low temperature and non-corrosive environment. Without being disabled, the furnace temperature can be continuously estimated over a long period of time.

  Further, according to the in-furnace temperature estimation method of the present invention, the change value of the in-furnace temperature is estimated by using a value obtained by multiplying the in-furnace temperature change value by the correction coefficient. Thus, it is possible to estimate the temperature change value in the furnace regardless of whether the slag coating layer is formed or the thickness is changed.

  Therefore, according to the method of the present invention, the furnace temperature of the reactor whose inner surface is covered with the slag coating layer can be stably maintained for a long period of time regardless of the presence or absence of the slag coating layer and the change in thickness. It can be estimated with high reliability.

It is a figure which shows the structure of the furnace temperature estimation apparatus which is one Embodiment to which this invention is applied. It is sectional drawing for demonstrating the height of a burner when using the lower end of a reaction furnace as a reference | standard, a furnace temperature measurement part, the furnace wall internal thermometer side part, and a furnace wall external temperature measurement part. It is a figure for demonstrating how to obtain | require a correction coefficient. It is a figure which shows the curve showing the relationship between a furnace wall internal temperature and a correction coefficient. It is a figure which shows the relationship between the furnace wall internal temperature used when explaining an example of the furnace temperature estimation method, the furnace temperature, and elapsed time. It is a flowchart for demonstrating the furnace temperature estimation method which concerns on one embodiment of this invention. It is a figure which shows the relationship between the furnace wall internal temperature used when explaining the other example of the furnace temperature estimation method, the furnace temperature, and elapsed time.

  Hereinafter, the configuration of an in-furnace temperature estimation apparatus according to an embodiment to which the present invention is applied will be described in detail with reference to the drawings. Note that the drawings used in the following description may show the features that are enlarged for convenience in order to make the features easier to understand, and the dimensional ratios and the like of each component of the actual furnace temperature estimation device It is not always the same as actual.

  FIG. 1 is a diagram showing a configuration of an in-furnace temperature estimation apparatus that is an embodiment to which the present invention is applied. FIG. 1 shows a state where the slag coating layer 4 is thickest as an example. In FIG. 1, for convenience of explanation, the reaction furnace 2 and the slag coating layer 4 are illustrated in a horizontal section.

FIG. 2 is a cross-sectional view for explaining the height of the burner 5, the furnace temperature measurement unit 11, the furnace wall internal thermometer side part 12, and the furnace wall external temperature measurement unit 13 when the lower end of the reaction furnace is used as a reference. FIG.
In FIG. 2, for convenience of explanation, the burner 5, the furnace temperature measurement unit 11, the furnace wall internal thermometer side unit 12, and the furnace wall external temperature measurement unit 13 that do not exist on the same cut surface are illustrated on the same cut surface. . 2, the same components as those in the structure shown in FIG.

In the present invention, the temperature in the space defined by the slag coating layer 4 formed in the reaction furnace 2 is defined as “furnace temperature”, and the internal temperature of the furnace wall 3 constituting the reaction furnace 2 is defined as “furnace wall internal temperature”. The external temperature of the furnace wall constituting the reaction furnace 2 is referred to as “furnace wall external temperature”.
In the present embodiment, as an example, the temperature at a position 1 cm from the inner surface of the slag coating layer 4 to the reactor center side is measured as the furnace temperature, and the furnace wall internal temperature is measured in the thickness direction of the furnace wall 3. The temperature of the center position is measured, and the temperature of the outer surface of the furnace wall 3 is measured as the furnace wall external temperature.

  With reference to FIG.1 and FIG.2, the reactor apparatus 1 with a furnace temperature estimation function including the furnace temperature estimation apparatus 10 which is one Embodiment is demonstrated.

  The reactor apparatus 1 with an in-furnace temperature estimation function includes a reaction furnace 2, a plurality of burners 5, and an in-furnace temperature estimation apparatus 10. The furnace temperature estimation device 10 includes a furnace temperature measurement unit 11, a furnace wall internal temperature measurement unit 12, a furnace wall external temperature measurement unit 13, and a control device 14.

The reaction furnace 2 is formed of a refractory material. As the refractory material, for example, a refractory material containing 95% or more of alumina (Al ₂ O ₃ ) may be used.
When the reaction furnace 2 is a gasification furnace for power generation, the outer periphery of the reaction furnace 2 may be configured with water-cooled walls. The furnace wall 3 is provided with holes for inserting the burner 5, the furnace temperature measuring part 11, and the furnace wall inside thermometer side part 12.

  The plurality of burners 5 are arranged so as to penetrate the furnace wall 3 of the reaction furnace 2 from the outside of the reaction furnace 2 so that a swirl flow can be formed. It is preferable that the tip of the burner 5 protrudes into a space defined by the slag coating layer 4 so as not to be covered with the slag coating layer 4.

A plurality of burners 5 are mounted on the furnace wall 3 of the reaction furnace 2. Fuel and oxidant (not shown) are injected from the tips of the plurality of burners 5 in the circumferential direction inside the reaction furnace 2.
Thus, since the swirling flow can be generated in the reactor 2 by injecting the fuel and the oxidant in the circumferential direction, the ash content in the molten fuel can be moved to the furnace wall side. . If there are at least two burners 5, a swirling flow can be generated.

  When the fuel supplied to the inside of the reaction furnace 2 reacts with the oxidant, a high-temperature flame 6 (for example, a temperature range of 1300 ° C. to 1600 ° C.) is formed at the tip of the burner 5. When the fuel contains ash, the ash melts and adheres to the inner surface of the furnace wall 3 to form the slag coating layer 4. In the case of a gasification furnace, the operation state is managed so that the slag coating layer 4 is appropriately formed to protect the furnace wall 3.

The thickness of the slag coating layer 4 changes under the influence of a change in reaction temperature due to a change in the flow rate of fuel or oxidant. In the performance of the coal gasification furnace (hereinafter referred to as “gasification test furnace”) that the inventors have conducted tests, the thickness of the slag coating layer 4 varies in the range of 0 to 1 cm, for example.
The tip of the burner 5 and the tip of the in-furnace temperature measuring unit 11 protrude into the space defined by the slag coating layer 4 and are not normally covered by the slag coating layer 4.

  In FIG. 2, there is a gas outlet 7 at the top of the reactor 2, and a slag outlet 8 at the bottom of the reactor 2. The gas after the reaction is led out from the upper gas outlet 7 to a downstream gas purification device or the like. The molten slag flows down to the lower part of the reaction furnace 2 and is discharged from the slag discharge port 8 to the outside of the furnace.

About the installation position of the in-furnace temperature measurement part 11, it installs in the height direction of the reaction furnace 2 on the basis of the slag discharge port 8, for example, the same height as the burner 5, and / or higher than the height of the burner 5. .
The flame 6 formed at the tip of the burner 5 is formed to extend in the horizontal direction or slightly upward. The flame 6 is equal to the height of the burner 5 or includes a high temperature zone on the upper side thereof, and the ash is melted and slagged. Therefore, it is important to estimate and manage the temperature at this position from the viewpoint of protecting the furnace wall.

As for the installation position of the in-furnace temperature measuring unit 11 in the circumferential direction of the reaction furnace 2, for example, a position where molten slag is likely to adhere, such as the vicinity of the burner 5 or the position where the flame 6 of the burner 5 approaches the furnace wall 3. It is desirable to install in.
Further, it is desirable that the thermocouple installation position of the in-furnace temperature measurement unit 11 is installed so as to protrude into the space in the furnace so as not to be buried in the slag coating layer 4.

As an example of the installation position of the burner 5, if the height of the reaction furnace 2 with respect to the slag discharge port 8 is set to 1.00, the burner 5 may be installed at a height of 0.11 from the slag discharge port 8. it can.
In this case, the installation position of the in-furnace temperature measurement unit 11 can be installed at a height in the range of 0.11 to 0.15 from the slag discharge port 8, for example. In this case, the furnace wall internal thermometer side part 12 and the furnace wall external temperature measurement part 13 can be installed in the height of the range of 0.11 to 0.15 from the slag discharge port 8, for example.

  The furnace temperature of the reaction furnace 2 is, for example, 1300 ° C to 1600 ° C. At this temperature, the ash in the fuel melts. Therefore, the gasification furnace has a strongly reducing corrosive atmosphere. Further, when the reaction furnace 2 is a combustion furnace, an oxidizing atmosphere is formed as compared with a gasification furnace, but when the fuel contains a sulfur content or the like, a corrosive atmosphere is formed.

As a temperature measuring element of the in-furnace temperature measuring part 11, a thermocouple can be illustrated, for example. As a thermocouple capable of measuring a gas in a temperature range of 1300 ° C. to 1600 ° C., for example, a special type B sheathed thermocouple can be exemplified. As the special type B sheathed thermocouple, for example, a thermocouple using platinum rhodium (Pt—Rh40 / Pt—Rh20) as an electrode material and an iridium alloy as a material for a protective tube can be used.
As a result of the gasification test furnace, the life of a special type B sheathed thermocouple using an iridium alloy as a protective tube is as short as about 24 to 500 hours. When the temperature inside the furnace is increased using coal having a high ash melting point temperature, the thermocouple is disconnected in less than 24 hours.

As a temperature measurement element of the furnace wall internal temperature measurement part 12 which measures the furnace wall internal temperature, a thermocouple can be illustrated, for example. When a thermocouple is used as the furnace wall internal temperature measurement unit 12, the temperature at the installation position of the furnace wall internal temperature measurement unit 12 is, for example, in the range of 300 ° C to 1000 ° C.
In this case, examples of the thermocouple serving as the furnace wall internal temperature measurement unit 12 include a K-type thermocouple (electrode: NCF600 (Ni—Cr system / Ni system)). In addition, since there is no gas intrusion at the installation position of the furnace wall internal temperature measuring unit 12 and a low corrosion atmosphere, SUS310 is generally used as the material of the protective tube constituting the furnace wall internal thermometer side unit 12. is there.
In the results of the gasification test furnace, a K-type thermocouple using SUS310 as a protective tube was used as the furnace wall internal temperature measurement unit 12, but the thermocouple was never damaged.

Regarding the installation position of the furnace wall internal temperature measurement unit 12 in the height direction of the reaction furnace 2 and the installation position of the furnace wall internal temperature measurement unit 12 in the circumferential direction of the reaction furnace 2, It is preferable to set similarly.
Improve the estimation accuracy of the temperature in the reaction furnace 2 by arranging the furnace temperature measurement unit 11 and the furnace wall internal temperature measurement unit 12 along the heat flux direction from the reaction furnace 2 to the outside of the reaction furnace 2. Because you can.

  The furnace wall external temperature measurement unit 13 measures the temperature of the outer surface of the furnace wall constituting the reaction furnace 2. Since the temperature is usually the atmospheric temperature or the temperature of the water-cooled wall covering the furnace wall, there is little change in the temperature measurement value. For this reason, the measurement can be omitted, and for example, a fixed value such as a saturation temperature of saturated water flowing through the water-cooled wall can be used.

  Moreover, many furnace wall internal temperature measurement parts 12 can be installed in the circumferential direction of the reaction furnace 2, and the furnace temperature estimated value based on each furnace wall internal temperature measurement value can be calculated. By estimating the furnace temperature from each furnace wall internal temperature measurement value and calculating the average value of the estimated temperature, it is possible to improve the estimation accuracy of the furnace temperature. Since the atmosphere at the position where the furnace wall internal temperature measuring unit 12 is installed is a relatively low temperature of 300 ° C. to 1000 ° C. and a low corrosion environment as described above, the protective tube and the thermocouple are low grade, and An inexpensive one can be used. As a result, even if many furnace wall internal thermometer side parts 12 are installed, the cost does not increase greatly.

  As described above, by using a configuration in which the temperature inside the furnace is estimated using a plurality of furnace wall internal temperature measuring units 12, some thermometers are abnormal compared to the case of temperature measurement at only one location. The effect of reducing the estimation error that occurs in some cases occurs. For example, processing such as taking an average excluding the maximum value and the minimum value is possible. This produces an effect that the furnace temperature can be estimated with high accuracy.

  The control device 14 executes each process for estimating the furnace temperature. The control device 14 includes a storage unit 141 and a calculation unit 142.

  The storage unit 141 stores programs and various temperature measurement values. As the program, for example, there is a program for executing a furnace temperature estimation method such as calculation of a furnace wall internal temperature change value, correction coefficient calculation, furnace temperature estimated value calculation, and the like. Various temperature measurement values include furnace temperature measurement values, furnace wall internal temperature measurement values, furnace wall external temperature measurement values, furnace temperature initial values, furnace wall internal temperature initial values, and furnace wall external temperature initial values. is there. In addition, the storage unit 141 stores a correspondence relationship between the furnace wall internal temperature measurement value and the correction coefficient as a function generator.

  The calculation unit 142 calculates a change value of the measured temperature inside the furnace wall, calculates a correction coefficient corresponding to the temperature inside the furnace wall, calculates an estimated temperature inside the furnace, and the like.

FIG. 3 is a diagram for explaining how to obtain the correction coefficient.
Here, with reference to FIG. 3, the calculation method of the correction coefficient and the calculation formula of the estimated temperature in the furnace will be described.
In FIG. 3, the same components as those in the structure shown in FIG. Moreover, the meaning of each symbol in FIG. 3 is as follows.
S: sectional area through which heat passes = unit area (1 m ² )
Q: Heat flow rate per unit area (W / m ² )
λ _c : furnace wall thermal conductivity (W / m · ° C)
λ _s : thermal conductivity of slag coating layer 4 (W / m · ° C.)
L ₁ : Distance from the outer surface of the furnace wall 3 to the thermometer inside the furnace wall (m)
L ₂ : Distance from the furnace wall internal thermometer to the inner surface of the furnace wall 3 (m)
L ₃ : thickness of the slag coating layer 4 (m)
T ₁ : Furnace wall external temperature (° C.) which is the temperature of the outer surface of the furnace wall 3 forming the reaction furnace 2
T ₂ : Furnace wall internal temperature (° C.) which is the temperature inside the furnace wall 3 forming the reaction furnace 2
T ₃ : Temperature (° C.) of the furnace wall inner surface which is the temperature of the inner surface of the furnace wall 3 forming the reaction furnace 2
T ₄ : Furnace temperature (° C.)
T _b : temperature bias value (° C.) which is a difference obtained by subtracting the furnace wall internal temperature T ₂ from the furnace internal temperature T ₄

3, since the temperature T ₄ is furnace is at a temperature higher than the furnace wall outside the temperature T _1, heat is conducted toward the outside of the furnace from the furnace. The furnace wall 3 and the slag coating layer 4 have heat transfer resistance. Since the temperature drop caused by the heat transfer resistance, the furnace wall internal temperature T ₂ becomes lower than the furnace temperature T _4. Therefore, the furnace temperature can be calculated by adding a constant temperature bias value T _b , that is, (T ₄ −T ₂ ), to the furnace wall internal temperature T ₂ .

Further, the furnace when the furnace temperature T ₄ is changed, although a change in furnace wall internal temperature T _2, the change value of the furnace wall internal temperature T ₂ by the heat transfer resistance of the furnace wall 3 and the slag coating layer 4 It is smaller than the change value of the internal temperature T _4. Therefore, a value K × ΔT ₂ obtained by multiplying the change value ΔT ₂ of the furnace wall internal temperature T _{2 by} a predetermined ratio (correction coefficient: K) can be used as the estimated value of the change value of the furnace temperature T ₄ .

In summary, the furnace temperature T ₄ can be estimated by adding the temperature bias value T _b and the estimated value K × ΔT ₂ of the change value of the furnace temperature T _{4 to} the furnace wall internal temperature T ₂ . This relationship is expressed by the following formula (2).
T ₄ = T ₂ + T _b + K × ΔT ₂ (2)

Since the thickness of the slag coating layer 4 and the heat transfer resistance increases thick, the change of the furnace wall internal temperature T ₂ with respect to changes in furnace temperature T ₄ is reduced. Thus, the ratio of the change in value of the in-furnace temperature T ₄ with respect to the change value of the furnace wall internal temperature T _2, i.e. the correction coefficient K is larger as the thickness of the slag coating layer 4. When the slag coating layer 4 is thick, furnace wall internal temperature T ₂ is reduced. Therefore, the lower the furnace wall internal temperature T _2, the correction coefficient K is the ratio of the furnace change value of the temperature T ₄ for furnace wall internal temperature variation value [Delta] T ₂ increases.

That is, when low furnace wall internal temperature T _2, the correction coefficient K is larger, conversely, when the high furnace wall internal temperature T _2, the correction coefficient K is smaller. Therefore, the correction coefficient K, which is the ratio of the temperature change value in the furnace wall to the temperature change value ΔT _{2 in} the furnace wall, is inversely proportional to the temperature T ₂ in the furnace wall.

Figure 4 shows a variation of the correction coefficient K corresponding to the furnace wall internal temperature T _2. Furnace wall internal temperature T correction factor K as it goes ₂ to the cold zone is gradually increased, as it goes to the high temperature region on the opposite, the correction coefficient K is gradually decreased.

By using the correction coefficient K, the furnace temperature T ₄ can be obtained only from the furnace wall internal temperature T ₂ and the change value ΔT ₂ of the furnace wall internal temperature. Therefore, according to the formula (2), the furnace temperature can be estimated without being affected by the thermal conductivity of the slag coating layer 4.

FIG. 5 is a diagram illustrating the relationship between the furnace wall internal temperature and the furnace temperature and the elapsed time used when explaining an example of the furnace temperature estimation method.
With reference to FIG. 5, the calculation method of the furnace temperature estimated value will be described.

In FIG. 5, the current time is n. The time at which the in-furnace temperature estimation method is started is defined as 0, the in-furnace temperature at time 0 is the initial value T _{40 in} the in-furnace temperature, and the in-furnace wall temperature at time 0 is the initial in-wall temperature T ₂₀ , T ₄₀ to T _20. The value obtained by subtracting is used as the initial value T _b0 of the temperature bias value. The difference obtained by subtracting the current furnace wall internal temperature initial value T ₂₀ from the measured T _2n at time n and furnace wall internal temperature variation value [Delta] T _2n.

Further, a correction coefficient K (T _2n ) corresponding to the current furnace wall internal temperature T _2n is obtained. Then, the _{T b0} added to _{T 2n} measured at current time, adds the value obtained by multiplying the K _{(T 2n)} of the above [Delta] T _2n, it is possible to obtain the estimated value of the in-furnace temperature _{T 4.}

Relationship between the furnace wall internal temperature T ₂ and the correction factor K can be determined from the operating performance of the gasification test furnace. The relationship between the furnace wall internal temperature T ₂ and the correction coefficient K, if stored in advance as a function generator storage unit 141, obtains the furnace wall internal temperature measurement value T _2, the correction coefficient K corresponding to the value (T ₂ ) can be obtained. If you build a reactor to a new, and testing is performed during commissioning, it is possible to determine the relationship between the furnace wall internal temperature T ₂ and the correction coefficient K.

Relationship between the furnace wall internal temperature T ₂ and the correction coefficient K can also be determined from the heat transfer calculations for the heat flow towards the furnace out of the furnace.

  Referring to FIG. 3 again, a method for obtaining a correction coefficient by heat transfer calculation and a method for estimating the furnace temperature will be described.

In FIG. 3, the heat flow rate Q per unit area is expressed by the following equation.
Q = (T ₂ −T ₁ ) / (L ₁ / λ _c )
Q = (T ₄ −T ₂ ) / (L ₂ / λ _c + L ₃ / λ _s )
From the above relational expression, the relation between T ₄ and T ₂ is expressed by the following expression (3).
_{T 4 = T 2 + (L} 2 / λ c + L 3 / λ s) × (T 2 -T 1) / (L 1 / λ c) ··· (3)

From equation (3), the temperature bias value _{T b} which is the difference between _{T 4} and _{T 2} are, determined by the following equation (4).
_{T b = T 4 -T 2 =} (L 2 / λ c + L 3 / λ s) × (T 2 -T 1) / (L 1 / λ c)
(4)
The furnace wall internal temperature initial value T ₂₀ and furnace temperature initial value T ₄₀ of the measures, when the difference between the initial value T _b0 of temperature bias value, T _b0 is determined by the following equation (5).
_{T b0} = T 40 _{-T 20}
= (L ₂ / λ _c + L ₃ / λ _s ) × (T ₂₀ −T ₁ ) / (L ₁ / λ _c ) (5)
This is organized for T ₁ .
_{T 1 = T 20 -Tb 0 ×} (L 1 / λ c) / (L 2 / λ c + L 3 / λ s) ··· (6)
Substituting the above formula (6) into the above formula (3) and rearranging it gives the following formula (7).
T ₄ =
T ₂ + Tb ₀ + (L ₂ / λ _c + L ₃ / λ _s ) / (L ₁ / λ _c ) × (T ₂ −T ₂₀ ) (7)
On the other hand, the following relationship is obtained from the above equation (3).
_{L 2 / λ c + L 3} / λ s) / (L 1 / λ c) = (T 4 -T 2) / (T 2 -T 1) ··· (8)
Substituting the above equation (8) into the above equation (7) yields the following equation (9).
_{T 4 = T 2 + T b0} + (T 4 -T 2) / (T 2 -T 1) × (T 2 -T 20) ··· (9)

When the above expression (9) is made to correspond to the above expression (2), the correction coefficient K corresponding to the furnace wall internal temperature T ₂ and the furnace wall internal temperature change value ΔT ₂ are expressed by the following expressions (10) and (11). It can be seen that
K = (T ₄ −T ₂ ) / (T ₂ −T ₁ ) (10)
ΔT ₂ = T ₂ −T ₂₀ (11)

According to the estimation formulas of the above formulas (9) to (11), the furnace temperature T ₄ is estimated only by the furnace wall internal temperature T ₂ , the furnace wall external temperature T _1, and the furnace wall internal temperature change value ΔT _2. Can do. Therefore, the furnace temperature can be estimated regardless of the thermal conductivity of the slag coating layer 4.

Since the K of the equation (10) includes an estimation calculation result T ₄ of the furnace temperature, ingenuity is required for the calculation process.

One way of calculating the T _4, there is a method due to repeated calculations. First, T ₄ in the above equation (10) is set as the furnace temperature initial value T ₄₀ , T ₄ is calculated by the above equation (9), and the calculation result T ₄ is substituted into the above equation (10) again. T ₄ is calculated by substituting the correction coefficient obtained here into the equation (9). A correction coefficient which is obtained in this manner by substituting the calculation results above again (10) of T ₄ that calculates of T ₄ is substituted into Equation (9), determining of T ₄ by performing repetitive calculations Can do.

Further, in the above equation (10), the in-furnace temperature can be estimated assuming T ₄ as the in-furnace temperature initial value T ₄₀ . Further, since the outside temperature T ₁ is normally constant, it can be assumed that T ₁ is a constant value T ₁₀ . Placing the above assumption, _{T 4} can be calculated by the following equation (12) and (13).
_{K = (T 40 -T 2)} / (T 2 -T 10) ··· (12)
T ₄ = T ₂ + (T ₄₀ −T ₂₀ ) + K × ΔT ₂ (13)

According to the estimation formulas of the above equations (12) and (13), the furnace temperature T ₄ can be estimated only from the furnace wall internal temperature T ₂ and the furnace wall internal temperature change value ΔT ₂ . Therefore, the furnace temperature can be estimated regardless of the thermal conductivity of the slag coating layer.

  Next, a furnace temperature estimation method according to an embodiment will be described in detail with reference to the drawings.

  FIG. 6 is a diagram showing a flowchart of a furnace temperature estimation method according to an embodiment to which the present invention is applied.

  A furnace temperature estimation method according to an embodiment will be described with reference to FIGS.

  When the processing step shown in FIG. 6 is started, an in-furnace temperature measurement step of STEP 10 is first performed. In the in-furnace temperature measuring step, the measured value of the in-furnace temperature of the in-furnace temperature measuring unit 11 is AD converted. In the next in-furnace temperature initial value setting step of STEP 11, the current measured in-furnace temperature value converted by AD is stored in the storage unit 141 as the in-furnace temperature initial value.

  In the next step 12 of the furnace wall external temperature measurement step, the measured value of the furnace wall external temperature of the furnace wall external temperature measurement unit 13 is AD converted. In the next furnace wall external temperature initial value setting step in STEP 13, the current furnace wall external temperature measured value obtained by AD conversion is stored in the storage unit 141 as the furnace wall external temperature initial value. Then, it progresses to the furnace wall internal temperature measurement process of STEP14. In the furnace wall internal temperature measurement step, the measured value of the furnace wall internal temperature of the furnace wall internal temperature measurement unit 12 is AD converted. In the next furnace wall internal temperature initial value setting step of STEP 15, the current furnace wall internal temperature measured value obtained by AD conversion is stored in the storage unit 141 as the furnace wall internal temperature initial value.

  Then, it progresses to the furnace wall internal temperature measurement process of STEP20. In the furnace wall internal temperature measurement step, the measurement value of the furnace wall internal temperature of the furnace wall internal temperature measurement unit 12 is AD converted and stored in the storage unit 141 as the current furnace wall internal temperature measurement value. Next, in the furnace wall internal temperature change value calculation step of STEP 21, the furnace wall internal temperature measurement for a predetermined time stored in the storage unit 141 from the current furnace wall internal temperature measurement value stored in the storage unit 141. The value obtained by subtracting the value is calculated as the furnace wall internal temperature change value.

  In the subsequent correction coefficient calculation step of STEP 22, the correction coefficient is calculated using the function generator stored in the storage unit 141 based on the current value of the furnace wall internal temperature measurement value. In the subsequent step 23, the estimated temperature in the furnace is calculated by the above equation (2) using the value obtained by multiplying the change in the temperature in the furnace wall by the correction coefficient and the current value of the temperature in the furnace wall. To do.

  Here, in the correction coefficient calculation step of STEP 22, the correction coefficient K can also be calculated by the above equation (12). When the correction coefficient K is calculated by the above equation (12), the in-furnace temperature estimation value is calculated by the above equation (13) in the subsequent step 23 of the in-furnace temperature estimation step.

Further, in the correction coefficient calculation step of STEP 22, the correction coefficient K can be calculated by the above equation (10). When the correction coefficient K is calculated by the above equation (10), an estimated value of the in-furnace temperature T ₄ is calculated by the above equation (9) in the subsequent step 23 of estimating the furnace temperature. Then return to the correction coefficient calculating step of STEP 22, and calculates the correction coefficient K on the basis of the estimated value of the temperature in the furnace _{T 4} obtained in STEP23 by equation (10). Then at furnace temperature estimation process of STEP 23, based on the correction coefficient K obtained in the previous STEP22 the correction coefficient calculating step calculates an estimated value of the in-furnace temperature T ₄ by the equation (9).
Here the difference between the estimated value of the in-furnace temperature T ₄ of the estimate and the furnace temperature T ₄ previously determined that the determined iterate computed between the STEP22 and STEP23 to converge to within a predetermined threshold, the furnace Calculate the estimated temperature.
As the predetermined threshold, for example, a value of 10 ° C. can be taken.

  As described above, by adopting a configuration in which the calculation is repeatedly performed between the above formulas (10) and (9), the effect of obtaining a calculation result close to the theoretical value related to heat transfer is multiplied. Thereby, the effect that the precision of the estimation calculation of the furnace temperature can be improved is produced.

  In the next STEP 24, it is determined whether or not to end the processing step. When not finishing a processing process, it returns to the furnace wall internal temperature measurement process of STEP20. When the processing step is finished, the processing is finished.

In the above-described embodiment, the estimation of the furnace temperature is performed by continuously measuring only the temperature inside the furnace wall, which is a low temperature and non-corrosive atmosphere. This makes it difficult to cause damage to the thermocouple that is a temperature gauge. As a result, the furnace temperature can be estimated stably for a long time.
In addition, by using a correction coefficient that is a function of only the furnace wall internal temperature, the thermal conductivity from the inside of the furnace to the furnace wall internal thermometer is not considered in the furnace temperature estimation formula. As a result, there is an effect that the temperature in the furnace can be accurately estimated even if the presence or absence and the thickness of the slag coating layer are increased or decreased.

  Next, a furnace temperature estimation method according to another embodiment will be described.

  In another embodiment, the furnace temperature estimation step is the same as the flowchart shown in FIG. In another embodiment, the estimation method is a discrete value system. Therefore, the calculation method of the change value of the furnace wall internal temperature measurement value in the furnace wall internal temperature change value calculation process of STEP 21 and the furnace temperature estimation calculation formula in the furnace temperature estimation process of STEP 23 are different.

  In another embodiment, the furnace wall internal temperature is measured every predetermined sample time interval, and the furnace temperature estimation method is executed every sample time interval.

  In another embodiment, the change value of the furnace wall internal temperature measurement value is a value obtained by subtracting the furnace wall internal temperature measurement value one sample time interval before the current furnace wall internal temperature measurement value.

In this case, the estimated temperature in the furnace is calculated by the following equation (14). The correction coefficient K is set by a function generator.
T _4n = T _2n + (T ₄₀ −T ₂₀ ) + Σ _{(i = 1)} ⁽ⁿ⁻¹⁾ {K (T _2i ) × ΔT _2i } + K (T _2n ) × ΔT _2n (14)

In the above formula (14), n is an integer indicating the current time. n takes a value of 0 at the time when the in-furnace temperature estimation step starts operation, and thereafter is incremented by 1 every predetermined sample time interval.
T _4n indicates an estimated temperature T ₄ in the furnace at time n. _{Similarly, T 2n} represents the _{T 2} of the time n. That is, the subscript n indicates that each value is that of the current time.
T ₄₀ represents T ₄ at time 0, that is, the furnace temperature initial value. _{Similarly, T 20} denotes the initial value of _{T 2.}
K (T _2n ) is obtained by calculating a correction coefficient corresponding to T _2n using a function generator in which the relationship between the measured value of the furnace wall internal temperature and the correction coefficient is stored in advance. ΔT _2n is a change value of T ₂ at time n. It is specifically a value obtained by subtracting the _{T 2 (n-1)} from _{T 2n.}

i is an integer indicating the past time. i takes a value ranging from 1 to (n-1). A subscript i indicates that each value is a value at a past time i. That is, T _2i represents T ₂ at time i, K (T _2i ) represents a correction coefficient corresponding to T ₂ at time i, and ΔT _2i represents a change value of T ₂ at time i.

  A method for calculating the in-furnace temperature estimated value according to another embodiment will be described with reference to FIG. 7 showing the relationship between the in-furnace temperature and the elapsed time.

1 sample time interval from the furnace wall internal temperature measurement value T _2n measured current at time n before the furnace wall internal temperature measurement value T ₂ the difference obtained by subtracting the _(n-1) and furnace wall internal temperature variation value [Delta] T _2n. A value obtained by multiplying the furnace wall internal temperature change value ΔT _2n by a correction coefficient K (T _2n ) is defined as a furnace temperature change value. Then, the temperature bias value T _b0 is added to T _2n measured at the current time n, and the total value Σ _{(i = 1)} ^{(n− 1)} Add {K (T _2i ) × ΔT _2i } and a value obtained by multiplying the above ΔT _2n by K (T _2n ) to obtain an estimated value of the furnace temperature T ₄ .

Referring to FIG. 7, it can be seen that the value obtained by subtracting T _{4 (n−1)} from T _4n is a value obtained by adding ΔT ₂ and K (T _2n ) × ΔT _2n . Therefore, when the above equation (14) is modified, the furnace temperature can be estimated by the following equation (15).
T _4n = T _{4 (n-1)} + ΔT _2n + K (T _2n ) × ΔT _2n (15)

In the above equation (14), since only the furnace temperature estimated value T4 _(n−1) one sample time before is a past value, there is an effect that the value to be stored is reduced.

  In the other embodiments described above, an operation of facilitating digital processing by a digital computer is produced by the configuration of performing processing in a discrete value system. Thereby, there is an effect that program modules such as various filter operations and averaging processes used in digital processing can be easily used. As a result, the accuracy of the estimation calculation of the furnace temperature can be improved.

  The technical scope of the present invention is not limited to the above embodiment, and various modifications can be made without departing from the spirit of the present invention.

DESCRIPTION OF SYMBOLS 1 ... Reactor apparatus with in-furnace temperature estimation apparatus, 2 ... Reaction furnace, 3 ... Furnace wall, 4 ... Slag coating layer, 5 ... Burner, 6 ... Flame, 7 ... Gas outlet, 8 ... Slag discharge port, 10 ... Furnace Internal temperature estimation device, 11 ... Furnace temperature measurement unit, 12 ... Furnace wall internal temperature measurement unit, 13 ... Furnace wall external temperature measurement unit, 14 ... Control device, 141 ... Storage unit, 142 ... Calculation unit

Claims (8)

A furnace temperature estimation method for estimating a furnace temperature which is a temperature of a space defined by the slag coating layer of a reactor whose inner surface is covered with a slag coating layer,
The inside of the furnace wall that continuously measures the temperature measured inside the furnace wall, which is the temperature inside the furnace wall, using a first thermocouple partially disposed inside the furnace wall constituting the reactor Temperature measurement process,
A furnace wall internal temperature change value calculating step for calculating a furnace wall internal temperature change value that is a difference obtained by subtracting the furnace wall internal temperature measurement value of a predetermined time from the current furnace wall internal temperature measurement value;
A correction coefficient for converting the furnace wall internal temperature change value into the furnace temperature change value, wherein the correction coefficient is inversely proportional to the furnace wall internal temperature measurement value. A correction coefficient calculation step of calculating the correction coefficient based on the internal temperature measurement value;
A furnace for calculating the furnace temperature estimated value based on the following equation (1) including a term of a value obtained by multiplying the furnace wall internal temperature change value by the correction coefficient and a term of the furnace wall internal temperature measurement value. Internal temperature estimation process,
An in-furnace temperature estimation method.
T ₄ = T ₂ + (T ₄₀ −T ₂₀ ) + K (T ₂ ) × ΔT ₂ (1)
Here, in the above formula (1), T ₄ is the furnace temperature estimated value, T ₂ is the furnace wall internal temperature measurement value, K (T ₂ ) is the correction coefficient corresponding to T ₂ , and ΔT ₂ is the above The change value of the measured temperature inside the furnace wall, T ₄₀ is the initial value of the furnace temperature that is the measured value of the furnace temperature measured at the start of the furnace temperature estimation method, and T ₂₀ is the value of the furnace temperature estimation method. The furnace wall internal temperature initial value, which is the furnace wall internal temperature measurement value measured at the start, is shown.
The change value of the furnace wall internal temperature measurement value is a value obtained by subtracting the furnace wall internal temperature initial value from the furnace wall internal temperature measurement value.
The furnace temperature estimation method according to claim 1.
The correction coefficient is calculated based on the furnace wall internal temperature measurement value by a function generator in which a correspondence relationship between the furnace wall internal temperature measurement value and the correction coefficient is stored in advance.
The in-furnace temperature estimation method according to claim 2.
The correction coefficient corresponding to the furnace wall internal temperature measurement value is calculated by the following equation (2).
The in-furnace temperature estimation method according to claim 2.
K (T ₂ ) = (T ₄₀ −T ₂ ) / (T ₂ −T ₁₀ ) (2)
Here, in the above formula (2), K (T ₂ ) is a correction coefficient corresponding to T ₂ , T ₄₀ is a measured value of the furnace temperature measured at the start of the furnace temperature estimation method, and T ₂ is the furnace wall internal temperature measurements, T ₁₀ is a measurement of the external surface temperature of the furnace wall is measured at the start of the furnace temperature estimation method, respectively.
The furnace wall internal temperature is measured at predetermined sample time intervals, and the furnace temperature estimation method is a discrete value system calculation method executed at each sample time interval,
The change value of the furnace wall internal temperature measurement value is a value obtained by subtracting the furnace wall internal temperature measurement value before the sample time interval from the current furnace wall internal temperature measurement value.
The furnace temperature estimation method according to claim 1.
The estimated furnace temperature is:
The in-furnace temperature estimation method according to claim 5, which is calculated by the following equation (3).
T _4n = T _2n + (T ₄₀ -T ₂₀ ) + K (T _2n ) × ΔT _2n + Σ _{(i = 1)} ⁽ⁿ⁻¹⁾ {K (T _2i ) × ΔT _2i } (3)
Here, in the above formula (3), n is an integer indicating the current time, takes a value of 0 at the time when the in-furnace temperature estimation step starts operation, and thereafter 1 at each sampling time interval. Is added. T _4n is the estimated temperature inside the furnace at time n, T _2n is the measured value inside the furnace wall at time n, T ₄₀ is the initial temperature inside the furnace, and T ₂₀ is the initial temperature inside the furnace wall. Each is shown. K (T _2n ) is a correction coefficient corresponding to the furnace wall internal temperature measurement value T _2n at time n calculated by a function generator in which the relationship between the furnace wall internal temperature measurement value and the correction coefficient is stored in advance. Show. ΔT _2n indicates a value obtained by subtracting the furnace wall internal temperature measurement value at time (n−1) from the furnace wall internal temperature measurement value at time n. i is an integer indicating the past time, and takes a value from 1 to (n-1). T _2i indicates the measured value of the temperature inside the furnace wall at time i. K (T _2i ) is a correction coefficient corresponding to the furnace wall internal temperature measurement value T _2i at time i calculated by a function generator in which the relationship between the furnace wall internal temperature measurement value and the correction coefficient is stored in advance. Show. ΔT _2i represents a change value of the measured temperature inside the furnace wall at time i.
Storing the estimated temperature inside the furnace,
The estimated furnace temperature is:
The in-furnace temperature estimation method according to claim 5, which is calculated by the following equation (4).
T _4n = T _{4 (n−1)} + ΔT _2n + K (T _2n ) × ΔT _2n (4)
Here, in the above formula (4), n takes a value of 0 at the time when the in-furnace temperature estimation process starts to operate, and thereafter, the current time is incremented by 1 every predetermined sample time interval. Is an integer. T _4n represents the estimated temperature in the furnace at time n. T4 _(n-1) represents the estimated temperature in the furnace at time (n-1). ΔT _2n indicates a value obtained by subtracting the furnace wall internal temperature measurement value at time (n−1) from the furnace wall internal temperature measurement value at time n. T _2n indicates the furnace wall internal temperature measurement value T ₂ at time n. K (T _2n ) represents a correction coefficient corresponding to T _2n obtained using a function generator in which the relationship between the measured value inside the furnace wall temperature and the correction coefficient is stored in advance.
An in-furnace temperature estimation device for estimating an in-furnace temperature which is a temperature of a space defined by the slag coating layer of a reactor whose inner surface is covered with a slag coating layer,
The furnace temperature estimation device has a furnace temperature measurement unit that measures the furnace temperature, a furnace wall internal temperature measurement unit that measures the furnace wall internal temperature, and a control device,
The control device includes a storage unit and a calculation unit,
The thermocouple of the furnace wall internal temperature measurement unit is installed inside the furnace wall constituting a part of the reactor,
The storage unit stores a correspondence relationship between the furnace wall internal temperature measurement value and the correction coefficient as the function generator,
The calculation unit performs an in-furnace temperature estimation calculation using the correction coefficient.
An in-furnace temperature estimation device.