Temperature measuring device, temperature measuring method, and operation control method using the same

Abstract

To provide a temperature measuring device that can easily measure the temperature of an object facing the inside of a furnace without requiring any additional construction work. [Solution] The temperature measuring device 50 comprises a rod-shaped main body portion 51 extending in one direction from the outside FO toward the inside FI of the furnace, a folded portion 53 connected to the end of the main body portion 51 toward the inside FI and folded back in the opposite direction to the one direction, and a temperature measuring portion provided at the end of the folded portion 53 toward the opposite direction and in contact with the end face 21-2b1 of the splitter 21-2b which is the object to be measured and faces the inside FI of the furnace.

Description

Technical Field

[0001] The present disclosure relates to a temperature measuring device, a temperature measuring method, and an operation control method using the same, which are suitable for use in a burner provided in a boiler, for example.

Background Art

[0002] Large boilers such as power generation boilers have a furnace with a hollow shape installed vertically, and a plurality of burners are arranged along the circumferential direction of the furnace on the furnace wall. In addition, a flue is connected above the furnace in the vertical direction of the large boiler, and a heat exchanger for generating steam is arranged in this flue. Then, a flame is formed by injecting a mixture of fuel and air (oxidizing gas) into the furnace by the burner, combustion gas is generated and flows into the flue. A heat exchanger is installed in the region where the combustion gas flows, and water and steam flowing in the heat transfer tubes constituting the heat exchanger are heated to generate superheated steam.

[0003] A flame holder for maintaining the flame is provided at the tip of the burner. The flame holder faces the space inside the furnace. Particularly in a burner that has been extinguished, since the cooling effect by the combustion air cannot be obtained, it becomes high temperature due to the flame radiation inside the furnace, and there is a concern about burning out of the flame holder. Cooling air for preventing burning out is flowing through the burner during extinguishing, but the flow rate is determined by, for example, changing the flow rate of the cooling air during a test run to measure the temperature and determining the flow rate of the cooling air so that burning out does not occur.

[0004] A temperature sensor is installed in the flame holder for temperature measurement (see Patent Document 1).

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0006] However, as mentioned above, the flame holder becomes very hot, which can cause the temperature sensor to burn out or malfunction, making it unusable for extended periods. Furthermore, reinstalling the temperature sensor requires shutting down the boiler and undertaking extensive ancillary work, including the installation of scaffolding inside the furnace.

[0007] In recent years, the amount of electricity generated from renewable energy sources has been expanding. However, renewable energy sources face challenges in ensuring a stable supply of electricity, and a gap can occur between electricity demand and the amount of electricity generated from renewable sources. For thermal power plants, there is a need to expand the operating load range, especially to reduce the minimum operating load, in order to increase the capacity to adjust the supply and demand of electricity. Furthermore, there is a need to introduce carbon-neutral fuels such as biomass fuels to reduce CO2 emissions. To meet these demands, it has become necessary to change the cooling air volume settings from those used during commissioning. However, temperature sensors installed during construction are often already malfunctioning and unusable. If excessive cooling air is continuously supplied to the burner due to low-load operation or fuel changes, problems such as decreased plant efficiency, deterioration of exhaust gas properties discharged from the boiler, and reduced ignition and flame retention in the burner may occur.

[0008] This disclosure is made in view of these circumstances and aims to provide a temperature measuring device, a temperature measuring method, and an operation control method using the same that can easily measure the temperature of a measurement target facing the inside of a furnace without requiring any incidental construction work. [Means for solving the problem]

[0009] A temperature measuring device according to one aspect of the present disclosure comprises a rod-shaped main body extending in one direction from outside the furnace to inside the furnace, a bent portion connected to the end of the main body extending into the furnace and bent back in the opposite direction to the one direction, and a temperature measuring portion provided at the end of the bent portion extending in the opposite direction and in contact with the object to be measured facing the inside of the furnace.

[0010] A temperature measurement method according to one aspect of the present disclosure is a temperature measurement method using the above-described temperature measurement device, comprising: an insertion step of inserting the folded portion and the main body portion connected to the folded portion into the furnace from outside the furnace through an inspection opening; and a contact step of bringing the temperature measuring portion of the folded portion into contact with the object to be measured. The system includes an output acquisition step for acquiring the output detected by the temperature measuring unit.

[0011] An operation control method according to one aspect of this disclosure controls the operating state of a furnace based on the temperature obtained by the temperature measurement method described above. [Effects of the Invention]

[0012] It allows for the simple measurement of the temperature of an object facing the inside of a furnace without requiring any additional construction work. [Brief explanation of the drawing]

[0013] [Figure 1] This is a schematic diagram showing a boiler using the temperature measuring device of this disclosure. [Figure 2] This is a vertical cross-sectional view of the burner in a plan view. [Figure 3] This is a front view showing the fuel nozzle of the burner. [Figure 4] Figure 2 is a longitudinal cross-sectional view showing the burner with a temperature measuring device inserted. [Figure 5] This is a side view showing a temperature measuring device. [Figure 6] This is a plan view showing the positional relationship between the temperature measuring section at the folded-over part and the splitter. [Figure 7] This is a front view showing the folded portion positioned relative to the fuel nozzle. [Modes for carrying out the invention]

[0014] Hereinafter, an embodiment according to the present disclosure will be described with reference to the drawings. Note that the present invention is not limited by this embodiment, and when there are multiple embodiments, those configured by combining each embodiment are also included. In the following description, "upper" and "above" indicate the upper side in the vertical direction, and "lower" and "below" indicate the lower side in the vertical direction. The vertical direction is not strict and includes errors.

[0015] FIG. 1 shows a boiler 10 that uses solid fuel as the main fuel in this embodiment.

[0016] The boiler 10 is a boiler capable of burning pulverized fuel obtained by pulverizing solid fuel with a burner and exchanging heat between the heat generated by this combustion and feed water or steam to generate superheated steam. As the solid fuel, biomass fuel, coal, etc. are used.

[0017] The boiler 10 has a furnace 11, a combustion device 20, and a combustion gas passage 12. The furnace 11 has a hollow shape of a square cylinder and is installed along the vertical direction. The furnace wall 101 constituting the inner wall surface of the furnace 11 is composed of a plurality of heat transfer tubes and fins connecting the heat transfer tubes to each other, and recovers the heat generated by the combustion of the pulverized fuel by exchanging heat with water or steam flowing inside the heat transfer tubes, and suppresses the temperature rise of the furnace wall 101.

[0018] The combustion device 20 is installed in the lower region of the furnace 11. In this embodiment, the combustion device 20 has a plurality of burners 21A, 21B, 21C, 21D, 21E, 21F (hereinafter, may be collectively referred to as "burner 21") attached to the furnace wall 101. The burners 21 are arranged at equal intervals along the circumferential direction of the furnace 11 (for example, 4 installed at each corner of the square furnace 11) as one set, and are arranged in a plurality of stages along the vertical direction. In FIG. 1, for the convenience of illustration, only 2 of one set of burners are shown, and each set is labeled 21A, 21B, 21C, 21D, 21E, 21F. The shape of the furnace, the number of stages of the burners, the number of burners in one stage, the arrangement of the burners, etc. are not limited to this embodiment.

[0019] Burners 21A, 21B, 21C, 21D, 21E, and 21F are each connected to a plurality of mills (pulverizers) 31A, 31B, 31C, 31D, 31E, and 31F (hereinafter sometimes collectively referred to as "mill 31") via a plurality of pulverized fuel supply pipes 22A, 22B, 22C, 22D, 22E, and 22F (hereinafter sometimes collectively referred to as "pulverized fuel supply pipe 22"). The mill 31 pulverizes solid fuel into pulverized fuel. For example, a pulverizing table (not shown) is supported inside the mill 31 so as to be rotatable, and a plurality of pulverizing rollers (not shown) are supported above the pulverizing table so as to be rotatable in conjunction with the rotation of the pulverizing table. It is a vertical roller mill configured in this way. The solid fuel pulverized by the cooperation of the pulverizing roller and the pulverizing table is conveyed to a classifier (not shown) provided in the mill 31 by primary air (transport gas, oxidizing gas) supplied to the mill 31. In the classifier, the pulverized solid fuel is classified into pulverized fuel having a particle size suitable for combustion in the burner 21 and coarse powder fuel having a particle size larger than the above-mentioned particle size. The pulverized fuel that has passed through the classifier is supplied to the burner 21 via the pulverized fuel supply pipe 22 together with the primary air. The coarse powder fuel that has not passed through the classifier falls onto the pulverizing table inside the mill 31 due to its own weight and is pulverized again.

[0020] An air register 23 is provided outside the furnace of the furnace 11 at the mounting position of the burner 21, and one end of an air duct 24 is connected to this air register 23. A forced draft fan (FDF) 32 is connected to the other end of the air duct 24. The air supplied from the forced draft fan 32 is heated by an air preheater 42 installed in the air duct 24 (details will be described later), and is supplied to the burner 21 as secondary air (combustion air, oxidizing gas) via the air register 23 and is introduced into the furnace 11.

[0021] The combustion gas passage 12 is connected to the upper vertical part of the furnace 11. The combustion gas passage 12 is equipped with superheaters 102A, 102B, 102C (hereinafter sometimes collectively referred to as "superheater 102"), reheaters 103A, 103B (hereinafter sometimes collectively referred to as "reheater 103"), and an economizer 104 as heat exchangers for recovering heat from the combustion gas. Heat exchange takes place between the combustion gas generated in the furnace 11 and the feedwater or steam circulating inside each heat exchanger. Note that the arrangement and shape of each heat exchanger are not limited to the configuration shown in Figure 1.

[0022] Downstream of the combustion gas passage 12 is a flue 13 through which the combustion gas, whose heat has been recovered by the heat exchanger, is discharged. An air preheater (air heater) 42 is installed between the flue 13 and the air duct 24, and heat exchange takes place between the air flowing through the air duct 24 and the combustion gas flowing through the flue 13. By heating the primary air supplied to the mill 31 and the secondary air supplied to the burner 21, heat is further recovered from the combustion gas after heat exchange with water or steam.

[0023] Furthermore, a denitrification device 43 may be provided in the flue 13 at a position upstream of the air preheater 42. The denitrification device 43 supplies a reducing agent, such as ammonia or urea solution, which has the effect of reducing nitrogen oxides, to the combustion gas flowing through the flue 13. The reaction between the nitrogen oxides (NOx) in the combustion gas to which the reducing agent has been supplied and the reducing agent is promoted by the catalytic action of a denitrification catalyst installed in the denitrification device 43, thereby removing and reducing nitrogen oxides in the combustion gas.

[0024] A gas duct 41 is connected downstream of the air preheater 42 in the flue 13. The gas duct 41 is equipped with dust collection devices 44, such as an electrostatic precipitator, to remove ash and other particles from the combustion gas, and environmental devices such as a desulfurization device 46 to remove sulfur oxides, as well as an induced draft fan (IDF) 45 to guide the exhaust gas to these environmental devices. The downstream end of the gas duct 41 is connected to the chimney 47, and the combustion gas treated by the environmental devices is discharged outside the system as exhaust gas.

[0025] In the boiler 10, when multiple mills 31 are driven, the crushed and classified pulverized fuel is supplied to the burner 21 via the pulverized fuel supply pipe 22 along with primary air. In addition, secondary air heated by the air preheater 42 is supplied to the burner 21 from the air duct 24 via the wind box 23. The burner 21 blows a pulverized fuel mixture, which is a mixture of pulverized fuel and primary air, into the furnace 11, and also blows secondary air into the furnace 11. The pulverized fuel mixture blown into the furnace 11 ignites and reacts with the secondary air to form a flame. The flame is formed in the lower region of the furnace 11, and the high-temperature combustion gas rises inside the furnace 11 and flows into the combustion gas passage 12. In this embodiment, air is used as the oxidizing gas (primary air, secondary air), but a gas with a higher or lower oxygen content than air may also be used, and stable combustion in the furnace 11 can be achieved by adjusting the ratio of oxygen to the supplied fuel amount to an appropriate range. Furthermore, burner 21 that is not in use (extinguishing) is supplied with only the necessary amount of primary air for cooling to prevent burner 21 from burning out. If this cooling air becomes excessive, the amount of combustion air supplied to other burners that are in operation (ignited) will decrease, which may lead to problems such as a decrease in plant efficiency, deterioration of the exhaust gas properties discharged from boiler 10, and a decrease in the ignition and flame retention ability of burner 21.

[0026] The combustion gas flowing into the combustion gas passage 12 undergoes heat exchange with water and steam in the superheater 102, reheater 103, and economizer 104 located inside the combustion gas passage 12, before being discharged into the flue 13. There, nitrogen oxides are removed in the denitrification device 43, and after heat exchange with primary and secondary air in the air preheater 42, it is further discharged into the gas duct 41. Ash and other contaminants are removed in the dust collector 44, and sulfur oxides are removed in the desulfurization device 46 before being discharged out of the system through the chimney 47. Note that the arrangement of each heat exchanger in the combustion gas passage 12 and each device from the flue 13 to the gas duct 41 does not necessarily have to be in the order described above with respect to the combustion gas flow.

[0027] In the embodiments described above, the boiler of the present invention was described as a boiler that uses solid fuel. Examples of solid fuels used in the boiler include coal, biomass fuel, petroleum coke (PC) fuel, and petroleum residue. Furthermore, boiler fuels are not limited to solid fuels; liquid fuels such as heavy oil, light oil, heavy crude oil, and other petroleum products, as well as industrial wastewater and liquefied ammonia, can also be used. Gaseous fuels such as natural gas, various petroleum gases, by-product gases generated in steelmaking processes, hydrogen gas, and ammonia gas can also be used. Moreover, this technology can be applied to co-firing boilers that use a combination of these various fuels.

[0028] Figure 2 shows a longitudinal section of the burner 21 in a plan view. In this figure, the left side shows the in-furnace FI and the right side shows the out-furnace FO.

[0029] The burner 21 comprises a burner body 21-1, a fuel nozzle 21-2 connected to the tip of the burner body 21-1, and combustion air nozzles 21-3 provided around the fuel nozzles 21-2. Air is supplied to the combustion air nozzles 21-3 from the wind box 23 (see Figure 1).

[0030] The burner body 21-1 is connected to the fine fuel supply pipe 22 (see Figure 1), through which fine fuel and primary air flow. The downstream side (left side in the figure) of the burner body 21-1 extends in a substantially straight line along the axis CL direction, while the upstream side is bent at a substantially right angle via the bend portion 21-1a. However, the upstream side of the burner body 21-1 is not limited to being bent at a substantially right angle via the bend portion 21-1a.

[0031] An inspection port (insertion port) 21-1b is formed on the upstream side of the burner body 21-1, opening to the outside of the furnace FO so as to coincide with the extension of the axis CL. The inspection port 21-1b is closed by a cover (not shown) while the burner 21 is burning. Specifically, the inspection port 21-1b is closed by a cover (not shown) while the fine fuel is flowing inside the burner body 21-1. When measuring the temperature, the cover is removed and the inspection port 21-1b is opened so that the temperature measurement described later can be performed.

[0032] The fuel nozzle 21-2 is connected to the tip of the burner 21 and injects a combustible mixed fluid consisting of pulverized fuel and primary air towards the reactor FI. As shown in Figure 3, the fuel nozzle 21-2 is rectangular in shape and has a partition member 21-2a and a splitter 21-2b inside.

[0033] The partition members 21-2a are horizontally mounted plate-like bodies, and two are provided, one above the other. Each partition member 21-2a evenly divides the space of the fuel nozzle 21-2 in the vertical direction. Note that the number of partition members 21-2a is not limited to two; there may be one or three or more.

[0034] The splitters 21-2b extend vertically in the up-and-down direction and are arranged in five equally spaced rows. Each splitter 21-2b evenly divides the space of the fuel nozzle 21-2 horizontally. However, the number of rows of splitters 21-2b is not limited to five; it may be four or fewer rows, or six or more rows.

[0035] Each splitter 21-2b is fixed to the downstream end of the partition member 21-2a and has a wedge shape that widens from the upstream side to the downstream side (see, for example, Figure 6). Therefore, the downstream end face 21-2b1 of the splitter 21-2b faces the furnace interior FI and is an area that is easily exposed to flame radiation. The wedge-shaped splitter 21-2b functions as a flame holder to retain the flame.

[0036] The splitter 21-2b is described as having a structure divided vertically in the middle. However, the splitter 21-2b is not limited to this vertically divided structure.

[0037] Next, we will explain the temperature measurement of the burner 21 mentioned above. Figure 4 shows the temperature measuring device 50 inserted into the burner 21. The temperature measuring device 50 is inserted into the burner body 21-1 through the inspection port 21-1b along the axis CL. The temperature measuring device 50 may also be inserted at an angle to intersect the axis CL, depending on the position (measurement position) where the temperature sensing part described later is to be made contact.

[0038] The temperature measuring device 50 comprises a rod-shaped main body portion 51 extending in the axial direction CL (one direction) and a folded portion 53 connected to the tip of the main body portion 51 facing the furnace interior FI.

[0039] As shown in Figure 5, the main body 51 is composed of a plurality of divided sections 51a that are detachably connected to each other. Each divided section 51a is detachably fixed to the others by a screw structure 51b. Alternatively, other detachable structures such as a fitting structure may be used instead of the screw structure 51b.

[0040] The folded portion 53 is shaped to fold in the opposite direction to the furnace FI. Specifically, the folded portion 53 is J-shaped, hook-shaped, or rib-shaped. As schematically shown in Figure 6, a temperature measuring section 53a is provided at the folded tip of the folded portion 53 to contact the end face 21-2b1 (object to be measured) of the splitter 21-2b to measure the temperature.

[0041] A thermocouple is preferably used as the temperature measuring unit 53a. However, other temperature sensors may also be used, for example, a resistance thermometer may be used. The detection output from the temperature measuring unit 53a is transmitted to the control unit (not shown) of the boiler 10 via wiring (not shown). The wiring (not shown) is led to the outside of the furnace FO through a hole formed in the main body 51.

[0042] The control unit consists of, for example, a CPU (Central Processing Unit), RAM (Random Access Memory), ROM (Read Only Memory), and a computer-readable storage medium. A series of processes for realizing various functions are stored in the storage medium in the form of a program, for example. The CPU reads this program into the RAM and performs information processing and calculations to realize the various functions. The program may be pre-installed in ROM or other storage media, provided stored in a computer-readable storage medium, or distributed via wired or wireless communication. Computer-readable storage media include magnetic disks, magneto-optical disks, CD-ROMs, DVD-ROMs, and semiconductor memory.

[0043] Figure 7 shows the state in which the temperature measuring unit is positioned on the front side (furnace FI side) of the end face 21-2b1 of the splitter 21-2b by the folded portion 53. In this figure, the measurement is taken at the center in the vertical direction of the splitter 21-2b which is positioned in the center in the width direction, but it is also possible to measure at other positions or to measure other splitters 21-2b.

[0044] As shown in Figure 5, the main body 51 of the temperature measuring device 50 is equipped with a stopper 55 at its base end located outside the furnace FO. The stopper 55 is rod-shaped and protrudes in a direction perpendicular to the extending direction of the main body 51. The length of the stopper 55 (vertical dimension in Figure 5) is larger than the inner diameter of the inspection port 21-1b (see Figure 4). This prevents the temperature measuring device 50 from falling into the furnace FI side by having the stopper 55 catch on the inspection port 21-1b. Note that the shape of the stopper 55 is not limited to the shape shown in Figure 5; it is sufficient to have a portion that protrudes to the extent that it catches on the inspection port 21-1b.

[0045] It is preferable that the protruding direction of the stopper 55 coincides with the bending direction of the folded portion 53. This allows the operator to determine the angle at which the temperature sensing portion 53a is located around the axis of the main body portion 51, even if the folded portion 53 is not visible. Alternatively, instead of using the protruding direction of the stopper 55 as a marker to determine the angular position of the temperature sensing portion 53a, a mark formed on the main body portion 51 by engraving or printing may be used as a marker.

[0046] An extension 57 is provided at the base end of the main body 51, extending further from the stopper 55 towards the outside FO side. The extension 57 forms a counterweight corresponding to the weight of the main body 51 inserted into the furnace FI. Alternatively, a heavy object may be fixed to the extension 57 as the counterweight. The counterweight may be equal to the weight of the main body 51 inserted into the furnace FI, or it may be lighter or heavier than that weight, as long as it reduces the burden on the worker.

[0047] Next, a method for measuring temperature using the temperature measuring device 50 described above will be explained.

[0048] When the need arises to measure the temperature during operation of boiler 10, the cover of inspection port 21-1b is first removed and inspection port 21-1b is opened. At this time, flames are formed in the furnace of boiler 10, but the burner 21 used for temperature measurement is stopped (fire extinguished), and only primary air for cooling is supplied, with no pulverized fuel being supplied.

[0049] Then, in the work area outside the furnace FO, the worker inserts the main body 51 from the inspection port 21-1b toward the furnace FI, with the folded-over section 53 leading. At this time, the worker may pre-form a straight main body of a predetermined length by connecting a predetermined number of divided sections 51a in the work area outside the furnace FO.

[0050] While inserting the folded portion 53 toward the furnace FI, the worker extends the main body 51 by sequentially connecting the divided portions 51a. This allows the worker to hold the main body 51 outside the furnace FO and insert the folded portion 53 toward the furnace FI.

[0051] Insertion of the main body 51 is stopped when the temperature measuring section 53a, located at the tip of the folded section 53, passes through the splitter 21-2b. Specifically, the temperature measuring device 50 is inserted to the state shown in Figure 4. As shown in Figure 4, the stopper 55 is positioned on the outside FO side. The gripping position where the worker grasps the main body 51 is on the outside FO side closest to the inspection port 21-1b, for example, the position indicated by the symbol H in Figure 4. The stopper 55 is positioned on the outside FO side (to the right in Figure 4) of this gripping position H. The weight of the stopper 55 and the main body 51 (including the extension section 57) located on the outside FO side of the gripping position H becomes a counterweight corresponding to the weight of the temperature measuring device 50 inserted on the inside FI side of the furnace.

[0052] The operator then rotates the main body 51 around its axis to set the temperature measuring unit 53a to the desired angular position. At this time, the operator adjusts the angular position of the temperature measuring unit 53a while checking the protruding direction of the stopper 55 corresponding to the angular position of the temperature measuring unit 53a. Specifically, as shown in Figure 7, the operator positions the folded portion 53 so that the temperature measuring unit 53a is located at the desired position on the front surface (furnace FI side surface) of the end face 21-2b1 of the splitter 21-2b which is the object to be measured.

[0053] The operator then pulls the main body 51 towards the outside FO side (direction of arrow P in Figure 6) and brings the temperature measuring unit 53a into contact with the end face 21-2b1 of the splitter 21-2b. As a result, the temperature of the end face 21-2b1 is transmitted to the temperature measuring unit 53a and the temperature is measured. The temperature measurement value monitored by the control unit rises sharply due to heat conduction at the moment the temperature measuring unit 53a makes contact with the end face 21-2b1, so it is possible to confirm that the temperature measuring unit 53a has made contact. Although a sheathed thermocouple in which the thermocouple wires are arranged inside a sheath via an insulator can be used, it is also possible to measure the temperature by directly grounding the thermocouple wires to the object to be measured (without going through a sheath or insulator) to make it conductive. This makes it possible to measure the temperature only when it is grounded, so it is possible to more reliably confirm the timing when the temperature measuring unit 53a makes contact with the end face 21-2b1.

[0054] The temperature calculated by the control unit may be corrected using previously acquired calibration data. Calibration data can include the temperature measured by a temperature sensor fixed to the end face 21-2b1 of the splitter 21-2b during preliminary tests, or temperature data obtained from past operating records.

[0055] Based on the temperature data obtained as described above, the operating parameters of the boiler 10 are adjusted. For example, when the measured temperature is greater than a predetermined value, the flow rate of primary air (cooling air) supplied to the burner 21 is increased to increase the amount of cooling for the splitter 21-2b, etc. Conversely, when the temperature is less than a predetermined value, the flow rate of primary air (cooling air) supplied to the burner 21 may be decreased to reduce the amount of cooling for the splitter 21-2b, etc.

[0056] The effects and advantages of this embodiment, as described above, are as follows. The main body 51 of the temperature measuring device 50 is inserted into the furnace FI from the outside FO of the boiler 10, and the folded portion 53 connected to the tip of the main body 51 is guided to the end face 21-2b1 of the splitter 21-2b, which is the object to be measured. Then, the temperature measuring section 53a, which is provided at the tip of the folded portion 53 facing in the opposite direction, is brought into contact with the end face 21-2b1 facing the inside of the furnace, thereby measuring the temperature of the end face 21-2b1. By inserting the temperature measuring device 50 into the furnace FI in this way, the temperature of the object to be measured facing the furnace FI can be measured as needed, even while the boiler 10 is in operation. For this reason, there is no need to permanently install the temperature measuring device 50 in the furnace FI, and the temperature can be measured simply without requiring any additional construction work.

[0057] The main body 51 is composed of multiple divided sections 51a, and each divided section 51a is detachable from the others. This allows the length of the main body 51 to be adjusted according to the distance from the outside FO to the inside FI by arbitrarily adjusting the number of separated divided sections 51a, thereby expanding the range of application. Furthermore, since the main body 51 can be inserted into the inside FI while extending the main body 51 by sequentially connecting the separated divided sections 51a, work can be performed even when the working space outside FO is narrow.

[0058] By providing a stopper 55 at the base end of the main body 51 located outside the furnace FO, which protrudes in a direction intersecting the extending direction of the main body 51, the stopper 55 can be hooked onto the inspection port 21-1b of the temperature measuring device 50. This prevents the temperature measuring device 50 from accidentally falling into the furnace FI.

[0059] By providing an extension 57 that extends in the direction toward the outside of the furnace FO beyond the stopper 55, a counterweight is provided at the base end located at the outside of the furnace FO. This reduces the rotational moment at the gripping position H of the main body, which is generated by the weight of the main body 51 inserted into the furnace FI. Therefore, the burden on the worker can be reduced and work efficiency can be improved.

[0060] The position of the temperature measuring unit 53a provided on the folded portion 53 is determined by the bending direction of the folded portion 53, which is folded back relative to the tip of the main body 51 on the furnace side FI. In other words, the angle around the axis of the main body 51 is determined by the bending direction of the folded portion 53. The protruding direction of the stopper 55 located at the base end of the main body 51 outside the furnace is used as a marker to indicate the bending direction of the folded portion 53. This allows the operator operating from outside the furnace FO to determine the angular position of the temperature measuring unit 53a even if the folded portion 53 is not visible.

[0061] The temperature obtained by the temperature measuring device 50 is corrected in the control unit using configuration data. This reduces variations in temperature measurement.

[0062] The operation of the boiler 10 is controlled based on the temperature measured by the temperature measuring device 50. For example, when the measured temperature is higher than a predetermined value, the flow rate of primary air supplied to the burner 21 is increased to properly cool the splitter 21-2b and other components. Since the flow rate of primary air used for cooling can be properly maintained, damage to the splitter 21-2b and other components can be suppressed, and adverse effects such as a decrease in plant efficiency, deterioration of exhaust gas properties, and a decrease in ignition flame retention caused by excessive primary air input can be suppressed.

[0063] In the embodiments described above, the end face 21-2b1 of the splitter 21-2b was used as an example of the object to be measured for temperature. However, the object to be measured for temperature is not limited to this, and the above disclosure can be applied to any component of the burner 21 facing the furnace FI (for example, the tip of the partition member 21-2a).

[0064] The temperature measuring device, temperature measuring method, and operation control method using the same described in each embodiment above can be understood, for example, as follows.

[0065] A temperature measuring device (50) according to a first aspect of the present disclosure comprises a rod-shaped main body (51) extending in one direction from outside the furnace (FO) toward inside the furnace (FI), a bent portion (53) connected to the end of the main body toward inside the furnace and bent in the opposite direction to the one direction, and a temperature measuring portion (53a) provided at the end of the bent portion toward the opposite direction and in contact with the object to be measured facing inside the furnace.

[0066] The main body is inserted into the furnace from outside, and the folded-over section connected to the tip of the main body is guided to the object to be measured facing the furnace. Then, the temperature measuring section, located at the tip facing the opposite direction of the folded-over section, is brought into contact with the object facing the furnace to measure its temperature. By inserting the temperature measuring device into the furnace in this way, the temperature of an object facing the furnace can be measured as needed, even while the furnace is in operation. Therefore, there is no need to permanently install the temperature measuring device inside the furnace, and temperature can be measured simply without requiring any additional construction work.

[0067] In the second aspect of the present disclosure, the temperature measuring device (50) is configured such that the main body (51) is composed of a plurality of divided parts (51a) that are detachably connected to one another.

[0068] The main body is composed of multiple sections, each of which is detachable from the others. This allows the length of the main body to be adjusted according to the distance from outside to inside the furnace by arbitrarily adjusting the number of separated sections, thereby expanding the range of application. Furthermore, since the main body can be extended by sequentially connecting the separated sections and inserting it into the furnace, work can be performed even when the working space outside the furnace is narrow.

[0069] In the third aspect of the present disclosure, the temperature measuring device (50) is provided with the main body (51) having a stopper (55) at its base end located outside the furnace, which protrudes in a direction intersecting the extending direction of the main body.

[0070] By providing a stopper at the base end of the main body that protrudes in a direction intersecting the extending direction of the main body, the stopper can be hooked onto the insertion opening (e.g., inspection opening) of the temperature measuring device into the furnace. This prevents the temperature measuring device from accidentally falling into the furnace.

[0071] In the fourth aspect of the present disclosure, the temperature measuring device (50) is provided in any of the first to third aspects, wherein the main body (51) includes an extension (57) that extends further outward from the stopper (55).

[0072] By providing an extension that extends outward from the stopper, a counterweight is provided at the base end located outside the furnace. This reduces the rotational moment at the gripping position of the main body, which is generated by the weight of the main body inserted into the furnace. Therefore, the burden on the worker can be reduced and work efficiency can be improved.

[0073] In the fifth aspect of the present disclosure, the temperature measuring device (50) is provided in any of the first to fourth aspects, wherein the main body (51) is provided with a marker at the base end located outside the furnace that indicates the bending direction of the folded portion (53).

[0074] The position of the temperature-sensing part is determined by the direction of the bend of the folded-over section relative to the tip of the main body. In other words, the angle around the axial direction (one direction) of the main body is determined by the direction of the bend of the folded-over section. A marker indicating this direction of bend of the folded-over section is provided at the base end of the main body outside the furnace. This allows the operator to determine the angular position of the temperature-sensing part even if they cannot see the folded-over section from outside the furnace. The mark formed on the main body can be used as a marker, or the direction in which the stopper protrudes as described above can be used as a marker.

[0075] A temperature measurement method according to a first aspect of this disclosure is a temperature measurement method using a temperature measurement device (50) described in any of the first to fifth aspects, comprising: an insertion step of inserting the folded portion (53) and the main body portion (51) connected to the folded portion into the furnace from outside the furnace through an inspection port (21-1b); a contact step of bringing the temperature measuring portion (53a) of the folded portion into contact with the object to be measured; and an output acquisition step of acquiring the output detected by the temperature measuring portion.

[0076] In the second aspect of the present disclosure, the temperature measurement method is as follows: In the first aspect, the main body (51) is composed of a plurality of divided parts (51a) that are detachably connected to one another, and the insertion step involves sequentially connecting the divided parts (51a) outside the furnace to extend the main body (51) while inserting the main body into the furnace.

[0077] A temperature measurement method according to a third aspect of the present disclosure, in the first or second aspect, comprises a main body (51) composed of a plurality of divided parts (51a) that are detachably connected to one another, a temperature acquisition step of obtaining a temperature from an output obtained in the output acquisition step, and a correction step of correcting the temperature obtained in the temperature acquisition step.

[0078] By correcting the obtained temperature, variations in temperature measurement can be reduced. For example, the temperature of a temperature sensor fixed to the object being measured can be obtained in advance as calibration data, and the difference from this calibration data can be used for correction.

[0079] The operation control method according to the first aspect of this disclosure controls the operating state of the furnace based on the temperature obtained by any of the temperature measurement methods described in the first to third aspects.

[0080] The furnace operation is controlled based on the measured temperature. For example, if the burner's flame holder is the target of measurement, the amount of air supplied to the burner can be increased when the temperature is higher than a predetermined value to properly cool the flame holder and other components. This allows for proper maintenance of the flow rate of primary air used for cooling, thereby suppressing damage to the flame holder and other components, as well as mitigating adverse effects such as decreased plant efficiency, deterioration of exhaust gas properties, and reduced ignition and flame retention caused by excessive primary air input. [Explanation of Symbols]

[0081] 10 Boilers 11 Furnace 12 Combustion gas passage 13 Flue 20 Combustion device 21 Burner 21-1 Burner body 21-1a Bend section 21-1b Inspection hatch 21-2 Fuel Nozzle 21-2a Partition Member 21-2b Splitter 21-2b1 End face 21-3 Combustion air nozzle 22 Fine fuel supply pipe 23. Air register 24. Air ducts 31. Mill (Grinder) 32 Forced draft fan (FDF) 41 Gas duct 42 Air preheater 43 Denitration equipment 44 Dust collection device 45. Induced Draft Fan (IDF) 46 Desulfurization equipment 47 Chimney 50 Temperature measuring device 51 Main body 51a Split part 51b Screw structure 53 Folded section 55 Stopper 57 Extension CL axis FI furnace FO furnace outside H holds the position

Claims

1. A rod-shaped main body extending in one direction from outside the furnace towards the inside of the furnace, A folded portion is connected to the tip of the main body portion facing into the furnace, and is folded back in the opposite direction to the one direction, A temperature measuring section is provided at the tip of the folded portion facing the opposite direction, and which contacts the object to be measured facing the inside of the furnace, A temperature measuring device equipped with the following features.

2. The temperature measuring device according to claim 1, wherein the main body is composed of a plurality of divided parts that are detachably connected to one another.

3. The temperature measuring device according to claim 1 or 2, wherein the main body portion is provided with a stopper at its base end located outside the furnace, which protrudes in a direction intersecting the extending direction of the main body portion.

4. The temperature measuring device according to claim 3, wherein the main body portion is provided with an extension portion that extends in a direction toward the outside of the furnace from the stopper.

5. The temperature measuring device according to claim 1 or 2, wherein the main body portion is provided with a marker indicating the bending direction of the folded portion at the base end portion located outside the furnace.

6. A method for measuring temperature using the temperature measuring device described in claim 1, An insertion step involves inserting the folded portion and the main body portion connected to the folded portion into the furnace from outside through an inspection opening, A contact step in which the temperature measuring portion of the folded portion is brought into contact with the object to be measured, An output acquisition step is to acquire the output detected by the temperature measuring unit, A method for measuring temperature, comprising the following characteristics.

7. The main body is composed of a plurality of divided parts that are detachably connected to each other. The temperature measurement method according to claim 6, wherein the insertion step involves sequentially connecting the divided parts outside the furnace to extend the main body and inserting the main body into the furnace.

8. A temperature acquisition step, which obtains the temperature from the output obtained in the output acquisition step, A correction step for correcting the temperature obtained in the temperature acquisition step, A temperature measurement method according to claim 6 or 7, having the following characteristics:

9. An operation control method for controlling the operating state of a furnace based on the temperature obtained by the temperature measurement method described in claim 6 or 7.

Images