JP6655316B2 - Furnace temperature estimation method and furnace temperature estimation device - Google Patents

Description

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

  Coal, coke, biomass, and solid hydrocarbon fuels (hereinafter, simply referred to as "fuel") such as carbides (distillate) obtained by pyrolyzing industrial wastes at high temperatures (approximately 1300C to 1600C) In a reaction furnace such as a gasification furnace for gasification or a combustion furnace for burning fuel, it is necessary to measure the temperature in the reaction furnace and control it optimally so that the reaction proceeds properly. One such reactor is a coal gasifier.

  In the case of a coal gasifier, the ash contained in the fuel melts in the furnace and flows down along the walls, forming a slag coating layer for protecting the furnace walls. Further, by melting the ash in the reaction furnace and separating and removing the ash from the product gas, adverse effects on downstream gas purification equipment disposed downstream of the reaction furnace are prevented.

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

  Here, the temperature range to be measured and controlled is approximately 1300 ° C. to 1600 ° C. Conventionally, thermocouples have been most commonly used as such temperature measuring means. 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 temperature measuring means other than the thermocouple, for example, a radiation thermometer using radiant energy of a flame or a high-temperature gas in a reaction field 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.

  Patent Document 1 discloses that hot metal in a blast furnace is considered based on the temperature measured by a plurality of thermocouples installed at different positions in the axial direction of the tap hole of the blast furnace in consideration of the thermal conductivity of the tap hole mud and the like. Techniques for estimating temperature have been disclosed.

JP 2007-78475 A

As described above, the temperature inside a reaction furnace such as a gasification furnace or a combustion furnace is extremely high (about 1300 ° C. to 1600 ° C.). For this reason, if the protective tube of the above-mentioned thermocouple is used, it will be corroded and damaged by gas in a use environment and molten ash peculiar to solid fuel.
As a result, even the element wire of the thermocouple is damaged, and there is a problem that it cannot withstand long-time use.

On the other hand, when a radiation thermometer is used, there is a problem that the temperature cannot be accurately measured because the transparent sight window provided in the reactor is contaminated with molten ash and dust in the reactor.
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 keep it clean over a long period of time.
That is, it has been difficult to stably measure the temperature in the reactor accurately for a long period of time with the conventional method.

Further, when a slag coating layer made of molten ash is formed on the inner wall of a reaction furnace as in a coal gasification furnace, the thermal conductivity between the inside of the reaction furnace and the thermocouple changes.
For this reason, if the technology disclosed in Patent Document 1 is used, the thermal conductivity is included in the equation for estimating the temperature in the reactor, and if the thermal conductivity changes, the reliability of the estimated temperature in the furnace becomes low. There was a risk of lowering.

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

In order to solve the above problems, according to one aspect of the present invention, a furnace temperature for estimating a furnace temperature that is a temperature of a space defined by the slag coating layer in a reactor whose inner surface is covered with a slag coating layer is provided. Estimation method, using a first thermocouple partially disposed inside the furnace wall constituting the reaction furnace, the furnace wall internal temperature measurement value that is the temperature inside the furnace wall is continuously A furnace wall internal temperature measurement step, and a furnace wall internal temperature change value that is a difference obtained by subtracting the furnace wall internal temperature measurement value a predetermined time before from the current furnace wall internal temperature measurement value. A wall internal temperature change value calculating step, and a correction coefficient for converting the furnace wall internal temperature change value to a furnace internal temperature change value, wherein the correction coefficient is inversely proportional to the furnace wall internal temperature measurement value. Based on the above, based on the measured temperature inside the furnace wall, The following equation (1) includes a correction coefficient calculating step of 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. A furnace temperature estimation step of calculating the furnace temperature estimate based on the
Is provided.
T ₄ = T ₂ + (T ₄₀ −T ₂₀ ) + K (T ₂ ) × ΔT ₂ (1)
Here, in the above formula (1), the correction coefficient, [Delta] T _{2 T 4} is the furnace temperature estimate, _{T 2} is the furnace wall internal temperature measured value, K _{(T 2)} is corresponding to _{T 2} are the change value of the furnace wall internal temperature measurements, T ₄₀ is the furnace measurement at a reactor internal temperature initial value of the temperature measured at the start of the furnace temperature estimation method, T ₂₀ is 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 furnace temperature estimation method of the present invention, the furnace temperature can be estimated by continuously measuring the temperature inside the furnace wall, which is a low-temperature and non-corrosive environment. The temperature inside the furnace can be continuously and stably estimated for a long period without becoming impossible.

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

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

It is a figure showing composition of a furnace temperature estimating device which is one embodiment to which the present invention is applied. It is sectional drawing for demonstrating the height of the burner, the furnace temperature measurement part, the furnace wall inside thermometer side part, and the furnace wall outside temperature measurement part based on the lower end of a reaction furnace. FIG. 9 is a diagram for explaining how to obtain a correction coefficient. It is a figure showing a curve showing a relation between a furnace wall inside temperature and a correction coefficient. It is a figure which shows the relationship between a furnace wall internal temperature, furnace temperature, and elapsed time used when explaining an example of a furnace internal temperature estimation method. 4 is a flowchart for explaining a furnace temperature estimation method according to one embodiment of the present invention. It is a figure which shows the relationship between a furnace wall internal temperature, furnace temperature, and elapsed time used when explaining another example of the furnace temperature estimation method.

  Hereinafter, the configuration of a furnace temperature estimating apparatus according to an embodiment of the present invention will be described in detail with reference to the drawings. In the drawings used in the following description, in order to make the characteristics easy to understand, the characteristic portions may be enlarged for convenience, and the dimensional ratios and the like of the respective components of the actual in-furnace temperature estimating apparatus may be shown. It is not always the same.

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

FIG. 2 is a cross-sectional view for explaining the heights of the burner 5, the in-furnace temperature measuring unit 11, the inner wall of the furnace wall thermometer 12, and the outer wall of the furnace wall temperature measuring unit 13 with respect to the lower end of the reactor. FIG.
In FIG. 2, for convenience of description, the burner 5, the in-furnace temperature measuring unit 11, the furnace wall internal thermometer side part 12, and the furnace wall external temperature measuring unit 13 which are not present on the same cut surface are illustrated on the same cut surface. . 2, the same components as those of the structure shown in FIG. 1 are denoted by the same reference numerals.

In the present invention, the temperature in the space defined by the slag coating layer 4 formed in the reactor 2 is referred to as “furnace temperature”, and the internal temperature of the furnace wall 3 forming the reactor 2 is referred to 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, as a furnace temperature, a temperature at a position 1 cm from the inner surface of the slag coating layer 4 toward the center of the reactor from the inner surface of the slag coating layer 4 is measured. The temperature at the center position is measured, and the temperature on the outer surface of the furnace wall 3 is measured as the furnace wall outside temperature.

  With reference to FIGS. 1 and 2, a description will be given of a reactor apparatus 1 with a furnace temperature estimation function including a furnace temperature estimation apparatus 10 according to an embodiment.

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

The reactor 2 is made 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 a water-cooled wall. The furnace wall 3 is provided with holes for inserting the burner 5, the in-furnace temperature measuring unit 11, and the in-furnace-wall thermometer side 12.

  The plurality of burners 5 are arranged so as to penetrate the furnace wall 3 of the reactor 2 from outside the reactor 2 so as to form a swirling flow. The tip of the burner 5 preferably projects into a space defined by the slag coating layer 4 so as not to be covered by 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 (omitted in the figure) are injected from the tips of the plurality of burners 5 in the circumferential direction inside the reactor 2.
In this way, by injecting the fuel and the oxidant in the circumferential direction, it becomes possible to generate a swirling flow in the reactor 2, so that the ash in the molten fuel can be moved to the furnace wall side. . In addition, if there are at least two or more burners 5, a swirling flow can be generated.

  When the fuel and the oxidant supplied inside the reaction furnace 2 react with each other, a high-temperature (for example, a temperature range of 1300 ° C. to 1600 ° C.) flame 6 is formed at the tip of the burner 5. When ash is contained in the fuel, 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 the reaction temperature due to a change in the flow rate of the fuel or the oxidant. In the results of a coal gasifier (hereinafter referred to as “gasification test furnace”) in which the inventors have conducted tests, the thickness of the slag coating layer 4 varies, for example, in the range of 0 to 1 cm.
The tip of the burner 5 and the tip of the in-furnace temperature measuring unit 11 protrude into a space defined by the slag coating layer 4 and are not normally covered by the slag coating layer 4.

  In FIG. 2, a gas outlet 7 is provided at an upper part of the reactor 2, and a slag discharge port 8 is provided at a 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.

The installation position of the in-furnace temperature measurement unit 11 is, for example, installed at the same height as the burner 5 and / or above the height of the burner 5 in the height direction of the reaction furnace 2 with respect to the slag discharge port 8. .
The flame 6 formed at the tip of the burner 5 is formed to extend horizontally or slightly upward. The flame 6 includes a high-temperature zone at or above the height of the burner 5, and the ash melts and slags. Therefore, it is important to estimate and manage the temperature at this position from the viewpoint of furnace wall protection.

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

As an example, assuming that the height of the reactor 2 with respect to the slag outlet 8 is 1.00, the burner 5 can be installed at a height of 0.11 from the slag outlet 8 as an example. it can.
In this case, the installation position of the in-furnace temperature measurement unit 11 can be installed, for example, at a height of 0.11 to 0.15 from the slag discharge port 8. In this case, the furnace wall inside thermometer side part 12 and the furnace wall outside temperature measuring part 13 can be installed at a height in the range of 0.11 to 0.15 from the slag discharge port 8, for example.

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

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

As a temperature measuring element of the furnace wall internal temperature measuring unit 12 for measuring the furnace wall internal temperature, for example, a thermocouple can be exemplified. When a thermocouple is used as the furnace wall internal temperature measuring unit 12, the temperature at the installation position of the furnace wall internal temperature measuring unit 12 is, for example, in a range of 300 ° C to 1000 ° C.
In this case, as the thermocouple serving as the furnace wall internal temperature measurement unit 12, for example, a class K thermocouple (electrode: NCF600 (Ni-Cr-based / Ni-based)) can be exemplified. In addition, since there is no gas intrusion at the installation position of the furnace wall internal temperature measuring unit 12 and there is a low corrosive atmosphere, SUS310 is generally used as the material of the protective tube constituting the furnace wall internal temperature measuring side 12. is there.
According to the results of the gasification test furnace, a class K thermocouple using SUS310 as a protective tube was used as the furnace wall internal temperature measuring unit 12, but the thermocouple was not damaged.

The installation position of the furnace wall internal temperature measurement unit 12 in the height direction of the reactor 2 and the installation position of the furnace wall internal temperature measurement unit 12 in the circumferential direction of the reaction furnace 2 are the same as the installation position of the furnace temperature measurement unit 11. It is preferable to set similarly.
By disposing the in-furnace temperature measurement unit 11 and the in-furnace temperature measurement unit 12 along the heat flux direction from the inside of the reaction furnace 2 to the outside of the reaction furnace 2, the accuracy of estimating the temperature inside the reaction furnace 2 is improved. Because it can be.

  The furnace wall external temperature measuring 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 cooling wall covering the furnace wall, the change in the measured temperature value is small. Therefore, the measurement may be omitted and a fixed value such as the saturation temperature of the saturated water flowing through the water cooling wall may be used.

  In addition, a number of furnace wall internal temperature measuring units 12 are installed in the circumferential direction of the reaction furnace 2, and a furnace temperature estimated value based on each furnace wall internal temperature measured value can be calculated. By estimating the in-furnace temperature from the measured values of the in-furnace wall temperatures and calculating the average value of the estimated temperatures, it is possible to improve the accuracy of estimating the in-furnace temperature. As described above, the atmosphere at the position where the furnace wall internal temperature measurement unit 12 is installed has a relatively low temperature of 300 ° C. to 1000 ° C. and a low corrosive environment, so that the protection tube and the thermocouple are of low grade, and Inexpensive ones can be used. As a result, even if a large number of thermometer side portions 12 inside the furnace wall are provided, there is no significant increase in cost.

  As described above, by adopting a configuration in which the furnace temperature is estimated using the plurality of furnace wall internal temperature measurement units 12, some of the thermometers are abnormal as compared with a case where only one location is measured. The effect of reducing the estimation error that occurs in such a case occurs. For example, it is possible to perform processing such as taking an average excluding the maximum value and the minimum value. As a result, there is an effect that the furnace temperature can be accurately estimated.

  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. Examples of the program include a program for executing a furnace temperature estimation method such as calculation of a furnace wall temperature change value, calculation of a correction coefficient, calculation of a furnace temperature estimation value, and the like. The various temperature measurement values include a furnace temperature measurement value, a furnace wall internal temperature measurement value, and a furnace wall external temperature measurement value, and a furnace temperature initial value, a furnace wall internal temperature initial value, and a furnace wall external temperature initial value. is there. The storage unit 141 stores the correspondence 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 furnace wall internal temperature measurement value, calculates a correction coefficient corresponding to the furnace wall internal temperature, calculates a furnace internal temperature estimated value, and the like.

FIG. 3 is a diagram for explaining how to obtain a correction coefficient.
Here, a method of calculating the correction coefficient and a formula for calculating the estimated furnace temperature will be described with reference to FIG.
3, the same components as those of the structure shown in FIG. 1 are denoted by the same reference numerals. The meaning of each symbol in FIG. 3 is as follows.
S: cross-sectional area through which heat passes = unit area (1 m ² )
Q: heat flow rate per unit area (W / m ² )
λ _c : thermal conductivity of the furnace wall (W / m · ° C)
λ _s : thermal conductivity of the slag coating layer 4 (W / m · ° C.)
L ₁ : distance (m) from the outer surface of the furnace wall 3 to the thermometer inside the furnace wall
L ₂ : distance (m) from the furnace wall internal thermometer to the inner surface of the furnace wall 3
L ₃ : thickness (m) of the slag coating layer 4
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 : temperature inside the furnace wall (° C.) which is the temperature inside the furnace wall 3 forming the reaction furnace 2
T ₃ : temperature (° C.) of the inner surface of the furnace wall, 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 furnace wall temperature T ₂ from furnace 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. Thus, constant temperature bias to the furnace wall internal temperature _{T 2} value _{T b, i.e.,} it is possible to calculate the furnace temperature by the addition of _(T 4 -T _2).

When the furnace temperature T ₄ changes, the furnace wall internal temperature T ₂ changes. However, the change value of the furnace wall internal temperature T ₂ depends on 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 internal 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 equation (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. Accordingly, the correction coefficient K, which is the ratio of the furnace temperature change value to the furnace wall temperature change value ΔT ₂ , is in a relationship inversely proportional to the furnace wall temperature T ₂ .

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 change value [Delta] T ₂ of the furnace wall internal temperature T ₂ and the furnace wall inner temperature. Therefore, according to the above equation (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 internal temperature and the elapsed time used when describing an example of the furnace internal temperature estimation method.
With reference to FIG. 5, a method of calculating the estimated furnace temperature will be described.

In FIG. 5, the current time is set to n. The time to start the furnace temperature estimating method as 0, T ₂₀ the furnace temperature at time 0 furnace temperature initial value T _40, the furnace wall internal temperature at time 0 from the furnace wall internal temperature initial value T _20, T ₄₀ Is subtracted from the initial value _Tb0 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, T _b0 is added to T _2n measured at the current time, and a value obtained by multiplying K (T _2n ) by ΔT _2n is added to obtain an estimated value of the 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 of obtaining a correction coefficient by heat transfer calculation and a method of estimating the furnace temperature will be described.

In FIG. 3, the heat flow rate Q per unit area is represented 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 top of the relationship, the relationship between T ₄ and T ₂ are represented by the following formula (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 will be organized for T _1.
T ₁ = T ₂₀ −Tb ₀ × (L ₁ / λ _c ) / (L ₂ / λ _c + L ₃ / λ _s ) (6)
By substituting the above equation (6) into the above equation (3) and rearranging, the following equation (7) is obtained.
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)
By substituting the above equation (8) into the above equation (7), the following equation (9) is obtained.
T ₄ = T ₂ + T _b0 + (T ₄ −T ₂ ) / (T ₂ −T ₁ ) × (T ₂ −T ₂₀ ) (9)

When the above equation (9) is made to correspond to the above equation (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 equations (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 estimation formula in the above formula (9) to (11), the furnace temperature T ₄ is be estimated only by the furnace walls inside temperature T ₂ and the furnace wall outer temperatures T ₁ and the furnace wall internal temperature variation value [Delta] T ₂ Can be. Therefore, the furnace temperature can be estimated without depending on 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 equation (10) is calculated of _{T 4} of _{T 4} as furnace temperature initial value _{T 40} by the expression (9) is substituted into the result of the calculation of _{T 4} again equation (10). The correction coefficients calculated here is calculated of T ₄ is substituted into 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 be.

In the above equation (10), the furnace temperature can be estimated on the assumption that T ₄ is the furnace temperature initial value T ₄₀ . Further, since the out-furnace temperature _{T 1} of is usually constant, it can be assumed the _{T 1} 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 estimation formula in the above formula (12) and (13), the furnace temperature T ₄ can be estimated only by the furnace walls inside temperature T ₂ and the furnace wall inner temperature variation value [Delta] T _2. Therefore, the furnace temperature can be estimated without depending on 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.

  With reference to FIG. 1, FIG. 2, and FIG. 6, a method for estimating a furnace temperature according to one embodiment will be described.

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

  In the furnace wall outside temperature measurement step of the next STEP 12, the measured value of the furnace wall outside temperature of the furnace wall outside temperature measurement unit 13 is AD-converted. In the furnace wall external temperature initial value setting step in the next STEP 13, the current measured furnace wall external temperature value obtained by AD conversion is stored in the storage unit 141 as the furnace wall external temperature initial value. Subsequently, the process proceeds to a furnace wall internal temperature measurement step of STEP14. In the furnace wall inside temperature measurement step, the measured value of the furnace wall inside temperature of the furnace wall inside temperature measuring 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 measurement value obtained by AD conversion is stored in the storage unit 141 as the furnace wall internal temperature initial value.

  Subsequently, the process proceeds to a furnace wall internal temperature measurement step in STEP 20. In the furnace wall internal temperature measurement step, the measured value of the furnace wall internal temperature of the furnace wall internal temperature measuring unit 12 is A / D converted and stored in the storage unit 141 as the current furnace wall internal temperature measured 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 before stored in the storage unit 141 is performed based on the current furnace wall internal temperature measurement value stored in the storage unit 141. The value obtained by subtracting the value is calculated as a furnace wall internal temperature change value.

  In the subsequent correction coefficient calculation step in STEP 22, a 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 furnace temperature estimating step of STEP 23, the furnace temperature estimated value is calculated by the above equation (2) using the value obtained by multiplying the furnace wall temperature change value by the correction coefficient and the current value of the furnace wall temperature. I do.

  Here, in the correction coefficient calculation step of STEP 22, the correction coefficient K can be calculated by the above equation (12). When the correction coefficient K is calculated by the above equation (12), in the furnace temperature estimating step of STEP 23, an estimated furnace temperature is calculated by the above equation (13).

Further, in the correction coefficient calculation step of STEP 22, the correction coefficient K can be calculated by the above equation (10). If the correction coefficient K is calculated by the equation (10), In the subsequent STEP23 furnace temperature estimation step calculates an estimated value of the in-furnace temperature T ₄ by the equation (9). 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 temperature estimate.
As the predetermined threshold, for example, a value of 10 ° C. can be used.

  As described above, by performing the calculation repeatedly between the equations (10) and (9), the effect of obtaining a calculation result close to the theoretical value regarding heat transfer is multiplied. Thereby, there is an effect that the accuracy of the estimation calculation of the furnace temperature can be improved.

  In the next STEP 24, it is determined whether or not to end the processing steps. If the processing step is not completed, the process returns to the step 20 of measuring the temperature inside the furnace wall in STEP20. When ending the processing step, the processing is ended.

In the above embodiment, the estimation calculation of the furnace temperature is performed by continuously measuring only the inside temperature of the furnace wall which is a low-temperature and non-corrosive atmosphere. This makes it difficult for the thermocouple, which is a temperature measuring element, to be damaged. As a result, there is an effect that the furnace temperature can be stably estimated for a long time.
Further, the configuration in which the correction coefficient that is a function of only the furnace wall internal temperature is used has an effect that the thermal conductivity from the furnace inside to the furnace wall internal thermometer is not considered in the furnace temperature estimation formula. As a result, there is an effect that the furnace temperature can be accurately estimated even if the presence or absence and the thickness of the slag coating layer increase or decrease.

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

  In another embodiment, the in-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 step in STEP 21 is different from the furnace temperature estimation calculation formula in the furnace temperature estimation step of STEP 23.

  In another embodiment, the temperature inside the furnace wall is measured at predetermined sample time intervals, and the furnace temperature estimation method is executed at each 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 earlier from the current furnace wall internal temperature measurement value.

The estimated furnace temperature in this case 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 equation (14), n is an integer indicating the current time. n takes a value of 0 at the time when the in-furnace temperature estimating step starts operation, and thereafter is incremented by 1 at every predetermined sampling time interval.
T _4n indicates the furnace temperature estimated value T ₄ at time n. _{Similarly, T 2n} represents the _{T 2} of the time n. That is, the subscript n indicates that each value is the current time.
T ₄₀ is _{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 a value obtained by calculating a correction coefficient corresponding to T _2n using a function generator in which the relationship between the furnace wall internal temperature measured value 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 in the range of 1 to (n-1). The subscript i indicates that each value is a value at the past time i. That is, T _2i is T ₂ at time i, K (T _2i ) is a correction coefficient corresponding to T ₂ at time i, and ΔT _2i is a change value of T ₂ at time i.

  A method of calculating an estimated furnace temperature in this other embodiment will be described with reference to FIG. 7 showing a relationship between the furnace temperature and 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. The value obtained by multiplying the furnace wall internal temperature change value ΔT _2n by the correction coefficient K (T _2n ) is defined as the furnace internal temperature change value. Then, _{T 2n} measured current at time n, the addition temperature bias value _{T b0,} further, the time (n-1) the total value of the estimated value of the furnace temperature change value to 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, if 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 estimated furnace temperature T4 _(n-1) one sample time ago is a past value, the value to be stored is reduced.

  In the other embodiments described above, the configuration of performing the processing in the discrete value system has an effect of facilitating the digital processing by the digital computer. As a result, there is an effect that program modules for 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.

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

DESCRIPTION OF SYMBOLS 1 ... Reactor apparatus with a furnace internal temperature estimation apparatus, 2 ... Reactor, 3 ... Furnace wall, 4 ... Slag coating layer, 5 ... Burner, 6 ... Flame, 7 ... Gas outlet, 8 ... Slag discharge port, 10 ... Furnace Internal temperature estimating device, 11: furnace temperature measuring unit, 12: furnace wall internal temperature measuring unit, 13: furnace wall external temperature measuring unit, 14: control device, 141: storage unit, 142: arithmetic 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 the reactor whose inner surface is covered with the slag coating layer,
Using a first thermocouple partially disposed inside the furnace wall constituting the reaction furnace, the inside of the furnace wall for continuously measuring the measured value of the inside temperature of the furnace wall, which is the temperature inside the furnace wall Temperature measurement process,
A furnace wall internal temperature change value calculating step of calculating a furnace wall internal temperature change value that is a difference obtained by subtracting the furnace wall internal temperature measured value before a predetermined time from the current furnace wall internal temperature measured value,
A correction coefficient for converting the furnace wall internal temperature change value into a furnace internal 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 estimated furnace temperature based on the following equation (1) including a term of the furnace wall internal temperature change value multiplied by the correction coefficient and a term of the measured furnace wall internal temperature value: Internal temperature estimation process,
A furnace temperature estimation method having:
T ₄ = T ₂ + (T ₄₀ −T ₂₀ ) + K (T ₂ ) × ΔT ₂ (1)
Here, in the above formula (1), the correction coefficient, [Delta] T _{2 T 4} is the furnace temperature estimate, _{T 2} is the furnace wall internal temperature measured value, K _{(T 2)} is corresponding to _{T 2} are the change value of the furnace wall internal temperature measurements, T ₄₀ is the furnace measurement at a reactor internal temperature initial value of the temperature measured at the start of the furnace temperature estimation method, T ₂₀ is 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 method for estimating a furnace temperature according to claim 1.
The correction coefficient is based on the furnace wall internal temperature measurement value, and is calculated by a function generator that stores a correspondence relationship between the furnace wall internal temperature measurement value and the correction coefficient in advance.
The method for estimating a furnace temperature according to claim 2.
The correction coefficient corresponding to the furnace wall internal temperature measurement value is calculated by the following equation (2).
The method for estimating a furnace temperature according to claim 2.
K (T ₂ ) = (T ₄₀ −T ₂ ) / (T ₂ −T ₁₀ ) (2)
Here, in the above equation (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, 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 method for estimating a furnace temperature according to claim 1.
The estimated furnace temperature is:
The furnace temperature estimation method according to claim 5, wherein the method 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 equation (3), n is an integer indicating the current time, takes a value of 0 at the time when the in-furnace temperature estimating step starts operation, and thereafter, one by one at each of the sample time intervals. Is added. T _4n is the furnace temperature estimated value at time n, T _2n is the furnace wall temperature measurement value at time n, T ₄₀ is the furnace temperature initial value, and T ₂₀ is the furnace wall internal temperature initial value. Shown respectively. 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 indicates a change value of the furnace wall internal temperature measurement value at time i.
Having a step of storing the furnace temperature estimated value,
The estimated furnace temperature is:
The furnace temperature estimation method according to claim 5, wherein the method 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 equation (4), n takes a value of 0 at the time when the in-furnace temperature estimating step starts operation, and thereafter, the current time is added by one at a predetermined sampling time interval. Is an integer. T _4n indicates the estimated value of the furnace temperature at time n. T4 _(n-1) indicates the estimated value of the furnace temperature 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 measured value T ₂ of the temperature inside the furnace wall at time n. K (T _2n ) indicates a correction coefficient corresponding to T _2n obtained by using a function generator in which the relationship between the furnace wall internal temperature measured value and the correction coefficient is stored in advance.
A furnace temperature estimating device for estimating a furnace temperature which is a temperature of a space partitioned by the slag coating layer of the reactor whose inner surface is covered with the slag coating layer,
The in-furnace temperature estimating device includes a furnace temperature measuring unit that measures the furnace temperature, a furnace wall internal temperature measuring unit that measures an internal temperature of a furnace wall that forms the reaction furnace, and a control device. ,
The control device has a storage unit and an operation unit,
The thermocouple of the furnace wall internal temperature measurement unit is installed inside the furnace wall constituting a part of the reaction furnace,
The storage unit stores, as a function generator, a correspondence relationship between a furnace wall internal temperature measurement value measured by the furnace wall internal temperature measurement unit and a correction coefficient,
The calculation unit executes a furnace temperature estimation calculation using the correction coefficient,
An in-furnace temperature estimating device, characterized in that: