JP6339360B2 - BOILER WITH CORROSION CONTROL DEVICE AND BOILER CORROSION CONTROL METHOD - Google Patents

Description

  TECHNICAL FIELD The present invention relates to a boiler with a corrosion inhibiting device provided with a corrosion inhibiting device for preventing corrosion of a superheater tube of a boiler, and a boiler corrosion inhibiting method.

  As a conventional boiler, there is a boiler that burns fuel in a combustion furnace and superheats steam with a superheater by heat of combustion exhaust gas generated by the combustion to generate high-temperature and high-pressure superheated steam. This superheated steam can be used for power generation.

Here, in recent years, from the viewpoint of CO ₂ reduction and waste heat utilization, it is possible to use, for example, biomass such as construction waste wood and waste such as waste tires and plastic as fuel for boilers. It is being advanced.

In such biomass fuel and waste fuel, the fuel contains salts such as NaCl and KCl, and heavy metals such as lead and zinc. Accordingly, the combustion in the combustion furnace generates a low melting point (about 300 ° C.) molten salt composed of, for example, KCl, NaCl, ZnCl ₂ , K ₂ SO ₄ , Na ₂ SO _{4, and the} like. Flows along with the combustion ash to the superheater on the downstream side. Since this superheater generates high-temperature and high-pressure steam used for the power generation, the gas temperature is set higher than the steam temperature, and KCl, NaCl, ZnCl ₂ that has flowed in. , K ₂ SO ₄ , Na ₂ SO _4, etc. cause a problem that the superheater tube corrodes due to the molten salt adhering to the surface of the superheater tube constituting the high temperature superheater of 300 ° C. or higher. ing.

  Next, an example of a conventional boiler corrosion prevention method for solving the problem that the superheater tube corrodes in this way will be described (for example, see Patent Document 1).

  In this boiler corrosion suppression method, corrosion suppression particles having a particle size of 0.1 μm or more and less than 10 μm are supplied into the exhaust gas passage (for example, blown), and the surface of the superheater tube provided in the exhaust gas passage is supplied. By adhering, corrosion of the superheater tube is suppressed.

  According to this boiler corrosion inhibiting method, by supplying corrosion inhibiting particles having a particle diameter of 0.1 μm or more and less than 10 μm into the exhaust gas passage, the supplied corrosion inhibiting particles are subjected to thermophoresis with respect to the surface of the superheater tube. And can be attached by inertial collision. As a result, the corrosive particles having a particle diameter of 0.1 to 10 μm scattered in the exhaust gas passage can reduce the adhesion weight and the adhesion area adhering to the surface of the superheater tube, and the progress of corrosion of the superheater tube. Can be suppressed.

JP 2013-53829 A

  However, in the above conventional boiler corrosion suppression method, the temperature of the corrosion suppression particles is not set higher than the atmosphere around the outside of the boiler, so when the corrosion suppression particles are supplied into the exhaust gas passage, Due to the large temperature difference between the temperature of the combustion exhaust gas in the exhaust gas passage, where the temperature is much higher than that of the particles, and the temperature of the corrosion control particles, the corrosion-suppressing particles supplied in the exhaust gas passage cause the vicinity of the corrosion-inhibiting particles. The components in the combustion exhaust gas are cooled. As a result, the components in the combustion exhaust gas are condensed with the corrosion-inhibiting particles as the core, and the corrosion-inhibiting particles may become coarse.

  As a result, even if the coarsened corrosion-inhibiting particles can adhere to the surface of the superheater tube, corrosive particles (molten salt particles) having a smaller particle diameter are present on the outer surface of the corrosion-inhibiting particles. When attached, the corrosive particles having a small particle size may diffuse and pass through the gaps between the corrosion-inhibiting particles having a large particle size, and may adhere to the surface of the superheater tube.

  As a result, the conventional boiler corrosion suppression method may not effectively suppress the corrosion of the superheater tube. For example, when the corrosion of the superheater tube is fast, the supply weight of the corrosion-inhibiting particles can be increased. However, in this case, there is a problem that the cost of the corrosion-inhibiting particles increases.

  The present invention has been made in order to solve the above-described problems, and provides a boiler with a corrosion suppressing device capable of effectively suppressing corrosion of a superheater tube and a method for suppressing corrosion of a boiler. It is aimed.

A boiler with a corrosion inhibitor according to the present invention includes an exhaust gas passage through which combustion exhaust gas passes, a superheater pipe provided in the exhaust gas passage, and supplying corrosion-suppressing particles into the exhaust gas passage. a corrosion inhibiting device with a boiler and a corrosion inhibiting device for inhibiting corrosion,
The corrosion-inhibiting particle is a compound having a particle size of 0.1 μm or more and less than 10 μm, the main component being at least one element of Ca, Si, Al, Mg, and Fe,
The corrosion inhibiting device, the flow of the exhaust gas than the superheater tube high rather and wherein the corrosion inhibiting particles the exhaust gas passage of the low have a predetermined temperature above the melting point of the corrosion inhibiting particles than the atmosphere surrounding the boiler The gas is supplied to a region upstream of the direction and having a gas temperature lower than the melting point of the corrosion-inhibiting particles .

According to the boiler with a corrosion inhibiting device according to the present invention, by using the corrosion inhibiting device and supplying the corrosion inhibiting particles into the exhaust gas passage, the supplied corrosion inhibiting particles are supplied to the metal interface of the superheater tube or the outer surface thereof. Can be adhered to the surface of the corrosive layer formed (hereinafter also simply referred to as “metal interface of superheater tube”). Thereby, the corrosive particles scattered in the exhaust gas passage can reduce the adhesion weight and the adhesion area adhering to the metal interface of the superheater tube, and the progress of the corrosion of the superheater tube can be suppressed.
In the above corrosion suppression device, by supplying the corrosion suppression particles into the exhaust gas passage at a temperature lower than its melting point, the corrosion suppression particles can be prevented from melting and bonding to each other to increase the particle diameter. Corrosion-inhibiting particles can be attached to the entire surface of the corrosion layer formed on the metal interface of the superheater tube or its outer surface in a state where the particle diameter is originally small. Thereby, the progress of the corrosion of the entire surface of the superheater tube can be effectively suppressed.
Further, in the above corrosion suppression apparatus, the corrosion suppression particles are supplied to a region where the gas temperature in the exhaust gas passage is lower than the melting point of the corrosion suppression particles, so that the corrosion suppression particles are melted and bonded to each other. It is possible to prevent a part of the components from condensing with the corrosion-inhibiting particles as a nucleus and increasing the particle size, and the corrosion-inhibiting particles can be added to the superheater tube metal in the original small particle size. It can be adhered to the entire surface of the corrosion layer formed on the interface and its outer surface. Thereby, the progress of the corrosion of the entire surface of the superheater tube can be effectively suppressed.
The reason why the particle size of the corrosion-inhibiting particles is defined as 0.1 μm or more and less than 10 μm is that the corrosive particles that are the main cause of corroding the superheater tube have a particle size of 0.1 to 10 μm. This is because the corrosive particles are particles containing Na or K chloride, and such corrosive particles adhere to the metal interface or the like of the superheater tube, whereby the corrosion of the superheater tube proceeds.

  And a corrosion suppression apparatus can suppress the progress of corrosion of a superheater pipe | tube by supplying the corrosion suppression particle | grains of temperature higher than the atmosphere around a boiler in an exhaust gas channel | path.

  In this way, the progress of corrosion of the superheater tube can be further suppressed by making the temperature of the corrosion-inhibiting particles supplied into the exhaust gas passage higher than the ambient temperature around the boiler. This is because the temperature difference between the combustion exhaust gas and the corrosion-inhibiting particles can be reduced. When the temperature difference is thus reduced, the degree to which the components in the combustion exhaust gas near the corrosion suppression particles are cooled by the corrosion suppression particles supplied into the exhaust gas passage can be reduced. As a result, it is possible to prevent the components in the combustion exhaust gas from condensing with the corrosion-inhibiting particles as nuclei, and as a result, it is possible to suppress the corrosion-inhibiting particles from becoming coarse.

  In this way, the corrosion-inhibiting particles in which the coarsening is suppressed can reduce the adhesion weight and the adhesion area in which the corrosive particles adhere to the metal interface of the superheater tube, etc., compared to the corrosion-inhibiting particles in which the coarsening is not suppressed. It is possible to effectively suppress the progress of corrosion of the superheater tube.

  In the boiler with a corrosion suppressing apparatus according to the present invention, the corrosion suppressing particles include a heat source other than the boiler, heat held by the combustion exhaust gas or combustion ash in the exhaust gas passage, or heat held by steam generated in the boiler. It is preferable that the temperature be higher than the atmosphere around the boiler.

  In this way, by using a heat source other than the boiler so that the corrosion-inhibiting particles are at a higher temperature than the atmosphere around the boiler, the corrosion-inhibiting particles are raised to a desired temperature regardless of the operating state of the boiler. And coarsening of the corrosion-inhibiting particles can be appropriately suppressed. And since the vapor | steam of a boiler is not used in order to raise the temperature of a corrosion inhibitor particle, the temperature of a corrosion inhibitor particle can be raised, without reducing the output of a boiler. Moreover, since the output of a boiler is not reduced in this way, possibility that this invention can be applied to an existing boiler can be raised.

  Then, using the heat held by the combustion exhaust gas or combustion ash in the exhaust gas passage, if the corrosion-inhibiting particles are at a higher temperature than the atmosphere around the boiler, the thermal energy held by the combustion exhaust gas or combustion ash is increased. It can be used effectively.

  Further, for example, if the corrosion-suppressing particles have a higher temperature than the atmosphere around the boiler using the heat held by a part of the surplus steam among the steam generated in the boiler, the thermal energy possessed by the surplus steam. Can be used effectively.

In the boiler with a corrosion suppression device according to the present invention, the corrosion suppression device is configured to contact the corrosion-suppressing particles before being supplied into the exhaust gas passage with a transport fluid medium having a temperature higher than the predetermined temperature. It is preferable to have a heating device that heats the particles, and to supply both the corrosion-inhibiting particles heated by the heating device and the temperature thereof to the transport fluid medium into the exhaust gas passage.

  According to this corrosion inhibiting device, the corrosion inhibiting particles before being supplied into the exhaust gas passage can be heated by the heating device, and the heated corrosion inhibiting particles in a state where the temperature has risen are supplied into the exhaust gas passage. Can do. As a heat source for heating the corrosion-inhibiting particles by the heating device, a heat source other than the boiler, heat held by the combustion exhaust gas in the exhaust gas passage, or heat held by the steam generated in the boiler can be used.

  In the boiler with a corrosion inhibiting device according to the present invention, the corrosion inhibiting device may supply the corrosion inhibiting particles having a temperature of 150 to 200 ° C. into the exhaust gas passage.

  If it does in this way, progress of corrosion of a superheater pipe can be controlled more effectively.

  In the boiler with a corrosion suppressing device according to the present invention, the corrosion suppressing device is configured to discharge air from the blower as air flow from a transfer blower as a transfer fluid medium for supplying the corrosion suppressing particles into the exhaust gas passage. It is preferable to use combustion exhaust gas that is generated or steam generated in the boiler.

  As described above, when steam generated in the boiler is used as a conveying fluid medium for supplying the corrosion-inhibiting particles into the exhaust gas passage, the kinetic energy held by the steam is supplied to the corrosion-inhibiting particles in the exhaust gas passage. It can be used effectively as the transport energy.

  When combustion exhaust gas or steam is used as a fluid medium for conveyance, the heat held by the combustion exhaust gas or steam is effectively used as thermal energy for causing the corrosion-inhibiting particles to have a higher temperature than the atmosphere around the boiler. Can be used.

  In addition, when air blown from a transport blower is used as a transporting fluid medium for supplying corrosion-inhibiting particles into the exhaust gas passage, the corrosion-suppressing particles can be easily put into the exhaust gas passage by controlling the transport blower. Appropriately distributed.

  Therefore, by supplying corrosion-inhibiting particles having a particle size of about 0.1 μm or more and less than 10 μm to the corrosive particles to the exhaust gas passage and adhering to the metal interface of the superheater tube, the particle size is 0.1 to 10 μm. The corrosion weight of the superheater tube is reduced to reduce the weight and area of the superheater tube adhering to the metal interface of the superheater tube.

  In the boiler with a corrosion inhibiting device according to the present invention, the corrosion inhibiting particles may be combustion ash generated by the boiler, and the particle diameter may be more than 2 μm and less than 10 μm.

  Thus, by supplying combustion ash having a particle diameter of more than 2 μm and less than 10 μm into the exhaust gas passage, the progress of corrosion of the superheater tube can be suppressed because the particle diameter is 0.1 μm or more. This is because the burning ash having a particle size of 2 μm or less has a strong corrosive power, but the burning ash having a particle diameter of more than 2 μm and less than 10 μm has a weak corrosive power. Accordingly, by supplying combustion ash having a particle size with a weak corrosive force of more than 2 μm and less than 10 μm into the exhaust gas passage, the corrosive force of the combustion ash generated by the boiler on the superheater tube can be reduced. it can. If combustion ash is used as the corrosion inhibiting particles, the cost of the corrosion inhibiting particles can be reduced.

  In the boiler with a corrosion suppression device according to the present invention, the combustion ash as the corrosion suppression particles is at a temperature higher than the atmosphere around the boiler, using at least the heat held by the combustion ash. It is good to do.

  If it does in this way, the thermal energy which combustion ash holds can be used effectively.

In the method for inhibiting corrosion of a boiler according to the present invention, the corrosion-inhibiting particles at a predetermined temperature are located upstream of the superheater pipe in the exhaust gas passage of the boiler in the exhaust gas flow direction, and the gas temperature is higher than the melting point of the corrosion-inhibiting particles. Is a method of suppressing corrosion of the superheater tube by supplying to a lower region ,
The corrosion-inhibiting particle is a compound having a particle size of 0.1 μm or more and less than 10 μm, the main component being at least one element of Ca, Si, Al, Mg, and Fe,
The predetermined temperature is higher than an atmosphere around the boiler and lower than a melting point of the corrosion-inhibiting particles .
The method for inhibiting corrosion of the boiler heats the corrosion-inhibiting particles by bringing a fluid medium for conveyance higher than the predetermined temperature into contact with the corrosion-inhibiting particles before being supplied into the exhaust gas passage. Supplying both the corrosion-inhibiting particles and the transporting fluid medium into the exhaust gas passage may be included.

  The method for inhibiting corrosion of a boiler according to the present invention works in the same manner as the boiler with a corrosion inhibiting apparatus according to the present invention.

  According to the boiler with a corrosion inhibiting device and the boiler corrosion inhibiting method according to the present invention, by supplying the corrosion inhibiting particles to prevent coarsening into the exhaust gas passage, the corrosion inhibiting particles (in the vicinity of the boiler) that are not inhibited from coarsening. The progress of corrosion of the superheater tube can be suppressed as compared with the case where the corrosion-inhibiting particles having a temperature equal to or lower than that of the atmosphere are supplied into the exhaust gas passage. Thus, for example, when the progress of the corrosion of the superheater tube is defined at a predetermined speed, the supply weight of the corrosion suppressing particles supplied into the exhaust gas passage is used, and the corrosion suppressing particles that suppress the coarsening of the present invention are used. In this case, it is economical because it can be reduced as compared with the case of using corrosion-inhibiting particles in which coarsening is not suppressed.

  And according to the boiler with a corrosion inhibiting device and the method for inhibiting corrosion of a boiler according to the present invention, the progress of corrosion of the superheater tube can be suppressed more effectively than before, so the boiler can be stably continued for a long period of time. Can be used.

It is a schematic perspective view which shows the internal structure of the boiler with a corrosion inhibitor which concerns on 1st Embodiment of this invention. It is a block diagram which shows the control structure of the boiler which concerns on the 1st Embodiment. It is a block diagram showing the boiler concerning the 1st embodiment. It is a figure for demonstrating the boiler which concerns on the said 1st Embodiment, and is a figure which shows each component ratio in the combustion ash from which particle diameter differs. It is a figure for demonstrating the boiler which concerns on the said 1st Embodiment, and is a figure which shows the corrosion amount of the metal piece on the conditions which simulated the superheater pipe | tube by the combustion ash from which particle diameter differs. It is a figure for demonstrating the boiler which concerns on the said 1st Embodiment, and is a figure which shows the relationship between the addition ratio of a corrosion inhibitor particle, and the corrosion amount of the metal piece on the conditions which simulated the superheater pipe | tube. It is a figure for demonstrating the boiler which concerns on the said 1st Embodiment, and is a figure which shows the relationship between the addition rate of combustion ash, and the corrosion amount of the metal piece on the conditions which simulated the superheater pipe | tube. It is a block diagram showing the boiler concerning a 2nd embodiment of the invention. It is a block diagram which shows the same boiler which concerns on 3rd Embodiment of the same invention. It is a block diagram showing the boiler concerning a 4th embodiment of the invention. It is a block diagram showing the boiler concerning a 5th embodiment of the invention. It is a block diagram showing the boiler concerning a 6th embodiment of the invention. It is a block diagram showing the boiler concerning a 7th embodiment of the invention.

  First, the basic principle of the boiler with a corrosion inhibitor according to the present invention will be described. The inventor of the present application has a particle diameter of 0.1 to 10 μm scattered in the third flue 22 of the boiler 19 shown in FIG. 1, and corrosion containing Na or K chloride (for example, NaCl, KCl). The inventors investigated that the corrosion of the superheater tube 27 progresses when the conductive particles (particles as the oxidizing agent) adhere to the surface of the superheater tube 27 provided in the third flue 22. This particle diameter is a value obtained by measuring by, for example, a cascade impactor method.

  Accordingly, the corrosion suppression particles having the same particle size (0.1 μm or more and less than 10 μm) as the corrosive particles are supplied into, for example, the second flue 21 and adhered to the surface of the superheater tube 27, thereby burning. In order to suppress the progress of corrosion of the superheater tube 27 by reducing the weight and area of adhesion of corrosive particles having a particle diameter of 0.1 to 10 μm contained in the ash to the surface of the superheater tube 27 I made it.

  Furthermore, the corrosion inhibition mechanism by the corrosion inhibition particles will be described in detail.

(1) Corrosive particles having a particle size of 0.1 to 2 μm Corrosive particles having a particle size of 0.1 to 2 μm adhere to the metal interface of the superheater tube 27 mainly by thermophoresis. Of the particles scattered in the third flue 22, there are many corrosive particles containing Na or K chloride in the particles having a particle size of 0.1 to 2 μm. The corrosive particles have a high corrosive power.

  Therefore, corrosion occurs when these corrosive particles adhere to the metal interface of the superheater tube 27 or the like.

  Therefore, according to the boiler 19 with the corrosion suppressing device according to this embodiment, the corrosion suppressing device 59 (in FIG. 1, the corrosion is performed using the supply port 59a of the corrosion suppressing device 59 and having a particle diameter of 0.1 μm or more and less than 10 μm. By supplying the suppression particles into the second flue 21 (for example, by blowing), the supplied corrosion suppression particles are supplied to the metal interface of the superheater tube 27 provided in the third flue 22 or the like. In this way, the corrosive particles having a particle diameter of 0.1 to 2 μm in the third flue 22 adhere to the metal interface of the superheater tube 27 and the like. The adhesion area can be reduced, and the progress of corrosion of the superheater tube 27 can be suppressed.

(2) Corrosive particles having a particle diameter of 2 to 10 μm Some corrosive particles having a particle diameter of 2 to 10 μm adhere to the metal interface of the superheater tube 27 by thermophoresis, but inertial collision Therefore, there are many that adhere to the metal interface of the superheater tube 27.

  Of the particles (combustion ash) scattered in the third flue 22, the particles having a particle diameter of 2 to 10 μm are chlorinated with Na or K as compared with the particles having a particle diameter of 0.1 to 2 μm. It can be said that the corrosive force with respect to the superheater pipe | tube 27 is smaller than the case of said (1), since many corrosive particle | grains weaker than corrosive particle | grains containing a thing are contained.

  Further, in order for the corrosion to proceed, it is necessary for the corrosive particles to continuously adhere to the metal interface or the like of the superheater tube 27, but the particle size is 0.1 μm or more using the corrosion suppression device 59. When corrosion-suppressing particles of less than 10 μm are supplied into the second flue 21 and the supplied corrosion-suppressing particles adhere to the metal interface of the superheater tube 27 by inertial collision or thermophoresis, the superheater tube It is possible to prevent the corrosive particles adhering to the metal interface of 27 due to inertial collision or the like from diffusing and adhering to the metal interface of the superheater tube 27. Thereby, the progress of corrosion of the superheater tube 27 can be suppressed.

(3) Corrosion-inhibiting particles having a particle diameter of 10 μm or more Using the corrosion-inhibiting device 59, the corrosion-inhibiting particles having a particle diameter of 10 μm or more are supplied into the second flue 21, thereby supplying the supplied corrosion-inhibiting particles. When the particles are attached to the metal interface of the superheater tube 27 or the like, corrosive particles having a particle size of 0.1 to 10 μm enter through the gaps between the corrosion-inhibiting particles having a particle size of 10 μm or more. There is a high possibility of adhering to the metal interface. Therefore, when the corrosion-inhibiting particles having a particle diameter of 10 μm or more are used, the corrosion of the superheater tube 27 caused by the corrosive particles having a particle diameter of 0.1 to 10 μm can hardly be suppressed.

  Therefore, in this embodiment, the corrosion suppression particles having the same particle size (0.1 μm or more and less than 10 μm) as the corrosive particles having a particle size of 0.1 to 10 μm are supplied into the second flue 21 to be overheated. By adhering to the surface of the heater tube 27, the weight and area of adhesion of corrosive particles of 0.1 to 10 μm to the surface of the superheater tube 27 are reduced, and the progress of corrosion of the superheater tube 27 is suppressed. I tried to do it.

  Next, 1st Embodiment of the boiler 19 with a corrosion suppression apparatus which concerns on this invention, and the corrosion suppression method of a boiler is described with reference to FIGS. A boiler with a corrosion suppression device (hereinafter sometimes simply referred to as a “boiler”) 19 shown in FIG. 1 burns fuel in a combustion furnace 10, and superheater tubes are heated by the heat of combustion exhaust gas generated by the combustion. 27 can be heated to generate high-temperature and high-pressure superheated steam.

  And this boiler 19 is provided with the corrosion suppression apparatus 59, and this corrosion suppression apparatus 59 supplies this corrosion suppression particle | grain into the 2nd flue 21 (exhaust gas passage), and this downstream side is carried out. Corrosion of the provided superheater tube 27 can be suppressed.

  Further, the corrosion suppressing device 59 shown in FIG. 3 supplies corrosion suppressing particles having a temperature higher than that of the atmosphere around the outside of the boiler 19 into the second flue 21. The reason for this is to make the corrosion inhibition by the corrosion inhibition particles on the superheater tube 27 more effective, as will be described later.

  The boiler 19 shown in FIG. 1 is an exhaust heat boiler that uses, for example, a waste incinerator as the combustion furnace 10, and generates power using high-temperature and high-pressure superheated steam obtained through the superheater tube 27. Machine 11 is provided.

  As shown in FIG. 1, the waste incinerator (combustion furnace) 10 includes a hopper 12 for supplying waste. The hopper 12 is connected to the main combustion chamber 14 via the chute 13, and the dust supplied from the hopper 12 is sent to the main combustion chamber 14 through the chute 13. The main combustion chamber 14 is provided with a dry stoker 15, a combustion stoker 16, and a post-combustion stoker 17. Primary air is sent from below the stokers 15, 16, and 17, and secondary air is sent from the ceiling 14 a of the main combustion chamber 14.

  The garbage in the main combustion chamber 14 shown in FIG. 1 is first sent to the drying stoker 15 and dried and ignited by the primary air and the radiant heat of the main combustion chamber 14. The ignited garbage is sent to the combustion stoker 16. In addition, combustible gas is generated from the ignited garbage by thermal decomposition. This combustible gas is sent to the gas layer above the main combustion chamber 14 by the primary air, and flame burns with the secondary air in this gas layer. The temperature of the dust is further increased by the heat radiation accompanying the flame combustion. A part of the ignited garbage is combusted by the combustion stoker 16, and the remaining unburned portion is sent to the post-combustion stoker 17. Unburned waste is burned by the post-combustion stoker 17, and the incineration ash remaining after the combustion is discharged from the chute 18 to the outside.

  Further, as shown in FIG. 1, the main combustion chamber 14 is connected to a radiation chamber 20 provided in the boiler 19, and combustion exhaust gas generated by combustion of garbage is transferred from the main combustion chamber 14 to the radiation chamber 20. Will be sent. This combustion exhaust gas is burned again in the radiation chamber 20 and then led to the third flue 22 through the second flue 21 of the boiler 19 and then detoxified by the exhaust gas treatment facility 60 shown in FIG. After being made, it is released into the atmosphere.

  The boiler 19 shown in FIG. 1 is provided with a plurality of water pipes 23 connected to a boiler drum 24 on each of walls defining the radiation chamber 20 and the second flue 21. Water sent from the boiler drum 24 flows through the water pipe 23. The water in the water pipe 23 recovers the waste heat of the radiation chamber 20 or the second flue 21, part of which is evaporated to become brackish water and returned to the boiler drum 24. A part of the brackish water returning to the boiler drum 24 is vaporized to become steam. The steam is sent from the boiler drum 24 to a superheater 25 provided in the third flue 22 to be overheated. The superheated steam that has been heated up to high temperature and high pressure is sent to the turbine 26 and drives the generator 11.

  According to the boiler 19 configured as described above, the material volatilized during combustion and a part of the incineration ash (collectively referred to as “incineration ash etc.”) are caused by the combustion exhaust gas to the radiation chamber 20 and the second flue. 21, as well as the third flue 22, and deposit on the superheater tube 27 of the water tube 23 and the superheater 25. Such incineration ash and the like have high corrosiveness, and cause corrosion of the superheater tube 27 of the high-temperature superheater 25.

  Next, the corrosion inhibitor 59 will be described. The corrosion suppression device 59 is a device for suppressing the corrosion of the superheater tube 27 shown in FIG. And this corrosion suppression apparatus 59 is equipped with the particle | grain supply apparatus which can supply the corrosion suppression particle | grains in the 2nd flue 21, The corrosion suppression particle | grains are supplied in the 2nd flue 21 in FIG. A supply port 59a is provided in the side wall.

The corrosion-inhibiting particles are particles having a particle size of 0.1 μm or more and less than 10 μm, and are compounds containing at least one element of Ca, Si, Al, Mg, and Fe as a main component, for example, CaO, SiO ₂ It is.

  The corrosion inhibiting particles have a melting point of 800 ° C. or higher. The region where the corrosion inhibiting device 59 supplies the corrosion inhibiting particles is a region where the gas temperature in the exhaust gas passage of the boiler 19 is lower than the melting point of the corrosion inhibiting particles. That is, the corrosion-inhibiting particles are in a gas temperature region in which the corrosion-inhibiting particles are melted and bonded to each other by the combustion exhaust gas in the supplied region so that the particle diameter does not increase. In this embodiment, the corrosion-inhibiting particles are supplied into the second flue 21, and the second flue 21 is a region where the gas temperature of the combustion exhaust gas flowing inside thereof is lower than 800 ° C.

  Furthermore, in this embodiment, for example, a powder-like mixed material obtained by mixing the corrosion-inhibiting particles with powder (for example, incineration ash) having a particle diameter larger than that of the corrosion-inhibiting particles, The gas is supplied into the second flue 21.

  Next, the corrosion detection device 30, the control unit 100, and the corrosion suppression device 59 shown in FIGS. 1 and 2 will be described.

  As shown in FIG. 1, the corrosion detection device 30 is provided on the side wall portion of the third flue 22 of the boiler 19 and on the upstream side of the superheater 25 in the flow direction of the combustion exhaust gas. Located in the third flue 22. The corrosion detection device 30 has a pair of electrodes (not shown) provided in the third flue 22, and the degree of corrosion of the superheater tube 27 based on a change in electrical resistance between the pair of electrodes. And a corrosion detection signal corresponding to the degree of corrosion is generated.

  The control unit 100 controls the corrosion suppression device 59 based on the corrosion detection signal generated by the corrosion detection device 30 to control the supply weight of the corrosion suppression particles.

  Next, with reference to FIG. 3, the whole corrosion inhibitor 59 is demonstrated. As shown in FIG. 3, the distal end portion of the transport pipe 61 is connected to the supply port 59 a for the corrosion-inhibiting particles, and the proximal end portion of the transport pipe 61 is connected to the blowout port of the transport blower 62. Yes. Then, one end of the supply pipe 64 is connected to the bottom of the storage tank 63 for storing the corrosion-inhibiting particles, and the other end of the supply pipe 64 is connected to the middle part of the transport pipe 61 through the connection part 65. doing.

  According to this corrosion suppression device 59, when the conveying blower 62 sucks outside air (air) and blows out the sucked air (conveying fluid medium) from the blowing port, the blown air is transferred to the conveying pipe 61 and the supply port. It is fed into the second flue 21 through 59a. At this time, the corrosion-inhibiting particles stored in the storage tank 63 are supplied to the transfer pipe 61 through the supply pipe 64 by a supply device (not shown), and together with the air blown out from the transfer blower 62, in the second flue 21. The corrosion-inhibiting particles can be attached to the surface of the superheater tube 27.

  A heating device 66 is provided in the middle of the transport pipe 61 and upstream of the connection portion 65. The heating device 66 is for heating the air flowing in the transport pipe 61, and is, for example, a heat exchanger. According to the heating device 66, the air flowing in the transport pipe 61 can be heated, and the heated air can contact the corrosion-inhibiting particles in the transport pipe 61 and heat the corrosion-inhibiting particles. .

  According to this corrosion inhibiting device 59, the corrosion inhibiting particles can be heated before the corrosion inhibiting particles are supplied into the second flue 21, and thus heated, the temperature is higher than the atmosphere around the boiler 19. It is possible to supply the corrosion-inhibiting particles in a state in which the rise is in the second flue 21.

  The temperature at which the heating device 66 heats the air flowing through the transport pipe 61 is set so that the temperature of the corrosion-inhibiting particles supplied from the supply port 59a into the second flue 21 is, for example, 150 to 200 ° C. It is a possible temperature. Incidentally, the temperature of the combustion exhaust gas in the 2nd flue 21 is about 800 degreeC.

  Thus, heating the corrosion-inhibiting particles to a temperature of 150 to 200 ° C. increases the corrosion-inhibiting particles to such a temperature so that the corrosion-inhibiting effect of the corrosion-inhibiting particles on the superheater tube 27 is increased. It is because it improves. And it is for heating a corrosion suppression particle | grain to temperature lower than the melting | fusing point (800 degreeC or more). Moreover, it is also in order to save the consumption of the heat energy which takes in order to heat a corrosion inhibitor particle.

  As a heat source (heat supplied to the heat exchanger) for heating the corrosion-inhibiting particles by the heating device 66, for example, a heat source other than the boiler 19, heat held by the combustion exhaust gas in the exhaust gas passage of the boiler 19, or the boiler The heat held by the steam generated at 19 can be used. Examples of the heat source other than the boiler 19 include combustion exhaust gas generated when fuel such as kerosene is burned.

  Further, as shown in FIG. 3, since the air blown from the transport blower 62 is used as the transport fluid medium for supplying the corrosion-inhibiting particles into the second flue 21, the transport blower is By controlling, the corrosion-inhibiting particles can be easily dispersed and supplied in the exhaust gas passage.

Next, the effect | action of the boiler 19 with a corrosion suppression apparatus comprised as mentioned above and the corrosion suppression method of a boiler is demonstrated. According to the boiler 19 with a corrosion inhibiting device according to this embodiment, the corrosion inhibiting device 59 shown in FIG. 1 is used to corrode corrosion inhibiting particles (for example, CaO, SiO ₂ ) having a particle diameter of 0.1 μm or more and less than 10 μm. 2 By supplying the inside of the flue 21, the supplied corrosion inhibiting particles are applied to the metal interface of the superheater tube 27 and the surface of the corrosion layer formed on the outer surface thereof (metal interface of the superheater tube 27, etc.). It can be attached by thermophoresis or inertial collision. As a result, the corrosive particles (for example, KCl, NaCl) having a particle diameter of 0.1 to 10 μm scattered in the third flue 22 reduce the adhesion weight and adhesion area adhering to the metal interface of the superheater tube 27. The progress of corrosion of the superheater tube 27 can be suppressed.

  And the corrosion suppression apparatus 59 suppresses progress of the corrosion of the superheater pipe | tube 27 effectively by supplying the corrosion suppression particle | grains of temperature higher than the atmosphere around the boiler 19 in the 2nd flue 21. Can do.

  In this way, the progress of the corrosion of the superheater tube 27 can be effectively suppressed by making the temperature of the corrosion suppressing particles supplied into the second flue 21 higher than the atmosphere around the boiler 19. This is because the temperature difference between the second flue 21 and the corrosion-inhibiting particles can be reduced. When the temperature difference is thus reduced, the degree to which the components in the combustion exhaust gas near the corrosion suppression particles are cooled by the corrosion suppression particles supplied into the second flue 21 can be reduced. As a result, it is possible to prevent the components in the combustion exhaust gas from condensing with the corrosion-inhibiting particles as nuclei, and as a result, it is possible to suppress the corrosion-inhibiting particles from becoming coarse.

  In this way, the corrosion-inhibiting particles having a particle size of 0.1 μm or more and less than 10 μm in which coarsening is suppressed adhere more to the metal interface of the superheater tube 27 than the corrosion-inhibiting particles in which coarsening is not suppressed. Therefore, the progress of corrosion of the superheater tube 27 can be effectively suppressed.

  Accordingly, for example, when the progress of the corrosion of the superheater tube 27 is defined at a predetermined speed, the supply weight of the corrosion-inhibiting particles supplied into the second flue 21 is suppressed from being coarsened in this embodiment. When using corrosion-inhibiting particles, the corrosion-inhibiting particles (corrosion-inhibiting particles having a temperature equal to or lower than that of the atmosphere around the boiler 19), which is not inhibited from being coarsened, can be reduced and economical. Is.

  Therefore, the progress of corrosion of the superheater tube 27 can be suppressed more effectively than in the past. Therefore, the boiler 19 can be stably used continuously for a long time.

  Then, in the heating device 66 shown in FIG. 3, if the corrosion-inhibiting particles are at a temperature higher than the atmosphere around the boiler 19 using a heat source other than the boiler 19, regardless of the operating state of the boiler 19, The corrosion-inhibiting particles can be raised to a desired temperature, and the coarsening of the corrosion-inhibiting particles can be appropriately suppressed. And since the vapor | steam of the boiler 19 is not used in order to raise the temperature of a corrosion inhibitor particle, the temperature of a corrosion inhibitor particle can be raised, without reducing the output of the boiler 19. Moreover, since the output of the boiler 19 is not reduced in this way, the possibility that the corrosion suppressing device 59 of this embodiment can be applied to the existing boiler 19 can be increased.

  Then, in the heating device 66, if the heat of the combustion exhaust gas or combustion ash in the exhaust gas passage of the boiler 19 is used so that the corrosion inhibiting particles have a higher temperature than the atmosphere around the boiler 19, the combustion exhaust gas Or the thermal energy which combustion ash has can be used effectively.

  Further, in the heating device 66, for example, by using the heat held by a part of the surplus steam among the steam generated in the boiler 19, the corrosion-inhibiting particles have a higher temperature than the atmosphere around the boiler 19. The thermal energy possessed by the surplus steam can be used effectively.

  Furthermore, the heating device 66 shown in FIG. 3 heats the corrosion-inhibiting particles to a temperature lower than the melting point (800 ° C. or higher).

  In this way, the corrosion-inhibiting particles are heated to a temperature lower than their melting point and supplied into the second flue 21 to prevent the corrosion-inhibiting particles from melting and bonding to each other to increase the particle diameter. Corrosion layers formed on the metal interface of the superheater tube 27 and its outer surface in a state where the particle size of the corrosion-inhibiting particles is originally small (for example, a state where the particle size is 0.1 μm or more and less than 10 μm) It can be attached to the entire surface. Thereby, the progress of corrosion on the entire surface of the superheater tube 27 can be effectively suppressed.

  And the corrosion suppression apparatus 59 supplies the corrosion suppression particle | grains of the temperature of 150-200 degreeC in the 2nd flue 21. As shown in FIG. If it does in this way, progress of corrosion of superheater pipe 27 can be controlled more effectively.

  Further, the region where the corrosion suppressing device 59 supplies the corrosion suppressing particles is the region in the second flue 21 where the gas temperature in the exhaust gas passage is lower than the melting point of the corrosion suppressing particles.

  In this way, by supplying the corrosion inhibiting particles to the region in the second flue 21 where the gas temperature in the exhaust gas passage of the boiler 19 is lower than the melting point of the corrosion inhibiting particles, the corrosion inhibiting particles are melted to each other. Bonding can prevent the particle diameter from increasing, and the corrosion-inhibiting particles are in a state where the particle diameter is originally small (for example, a state where the particle diameter is 0.1 μm or more and less than 10 μm). It can adhere to the whole surface of the corrosion layer formed in a metal interface or its outer surface. Thereby, the progress of corrosion on the entire surface of the superheater tube 27 can be effectively suppressed.

  Since the corrosion-inhibiting particles are compounds mainly composed of at least one element of Ca, Si, Al, Mg, and Fe, a compound mainly composed of relatively easily available elements is used for overheating. The progress of corrosion of the vessel tube 27 can be suppressed.

  Further, a powdery mixed material obtained by mixing the corrosion-inhibiting particles with powder (for example, incineration ash) having a particle size larger than that of the corrosion-inhibiting particles is used in the second flue 21 using the corrosion-inhibiting device 59. Therefore, even when the weight of the corrosion-inhibiting particles to be supplied into the second flue 21 is small, the corrosion-inhibiting device 59 is used to accurately add the corrosion-inhibiting particles having a desired weight. 2 can be fed into the flue 21. Further, by using an inexpensive powder having a particle diameter larger than that of the corrosion-inhibiting particles, for example, incineration ash, as the powder mixed with the corrosion-inhibiting particles, the cost of the powder can be reduced.

  Next, FIGS. 4 to 7 will be described. FIG. 4 shows the ratio of each component in the combustion ash having different particle diameters. In FIG. 4, the total of Ca (calcium), Cl (chlorine), and Na + K (sodium, potassium) is represented as 1. The particles having a small particle diameter are particles having a particle diameter Dp ≦ 2 μm. The particles having a medium particle size are particles having a particle size of 2 μm <particle size Dp <10 μm. The particles having a large particle diameter are particles having a particle diameter Dp ≧ 10 μm.

  As can be seen from FIG. 4, the combustion ash (particles) having a small particle diameter is composed of Cl and Na + K having a strong corrosive power, and a slight amount of inactive Ca having no corrosive power. Yes. Therefore, it can be said that the combustion ash with a small particle diameter has extremely strong corrosive power.

  About 62% of the combustion ash having a medium particle size is composed of Cl and Na + K having strong corrosive power, and the remaining 38% is composed of Ca having no corrosive power. Therefore, it can be said that the combustion ash having a medium particle diameter has a lower corrosive power than the combustion ash having a small particle diameter.

  Combustion ash having a large particle size is composed of approximately 38% Cl and Na + K having strong corrosive power, and the remaining approximately 62% is composed of Ca having no corrosive power. Therefore, it can be said that the combustion ash having a large particle diameter has a corrosive force smaller than that of the combustion ash having a small particle diameter and medium.

  FIG. 5 shows the amount of corrosion of a metal piece (hereinafter referred to as “simulated superheater tube”) under conditions simulating the superheater tube 27 due to combustion ash having different particle diameters. As can be seen from FIG. 5, it can be said that the combustion ash having a small particle diameter has extremely strong corrosive power as compared with the combustion ash having a medium particle diameter. And it can be said that the combustion ash with a medium particle diameter has weak corrosive power. Although not shown in the figure, the combustion ash having a large particle size has extremely weak corrosive power.

  FIG. 6 is a diagram showing the relationship between the addition ratio of the corrosion-inhibiting particles and the corrosion amount of the simulated superheater tube. In other words, when adding corrosion inhibiting particles with a small particle size to combustion ash with a small corrosive particle size, increasing the addition ratio of the corrosion inhibiting particles increases the simulated superheater tube. It can be seen that the amount of corrosion decreases. As can be seen from this figure, when the addition ratio of the corrosion-inhibiting particles is about 50%, the amount of corrosion can be reduced to about 2/5 compared with the case where the corrosion-inhibiting particles are not added. An effect can be obtained.

  FIG. 7 is a diagram showing the relationship between the addition ratio of combustion ash and the amount of corrosion of the simulated superheater tube. In FIG. 6, the corrosion-inhibiting particles having a small particle size are added to the combustion ash having a small corrosive particle size. In FIG. 7, the combustion ash having a medium particle size is added to the combustion ash having a strong corrosive particle size. An example of addition to small combustion ash is shown. As can be seen from FIG. 5, the combustion ash having a medium particle size is weakly corrosive. Therefore, it can be seen that when the addition ratio is about 50%, a large corrosion inhibition effect can be obtained.

  Next, 2nd Embodiment of the boiler with a corrosion inhibitor which concerns on this invention is described with reference to FIG. The difference between the boiler 68 with a corrosion suppression device of the second embodiment shown in FIG. 8 and the boiler 19 with the corrosion suppression device of the first embodiment shown in FIG. 3 is that the corrosion suppression devices 69 and 59 are different. .

  3 is different from the corrosion suppression device 59 of the second embodiment shown in FIG. 8 in the first embodiment shown in FIG. A heating device 66 is provided in the middle of heating, and the air flowing through the transport pipe 61 is heated by the heating device 66. Then, the heated air comes into contact with the corrosion-inhibiting particles in the transport pipe 61, and the corrosion-inhibiting particles are removed. In the second embodiment shown in FIG. 8, the storage tank 63 is heated from the outside by a heating device 70 such as a heat exchanger, or the storage tank 63 is heated. A heating device such as a heat exchanger is disposed inside to heat the corrosion-inhibiting particles accommodated in the storage tank 63.

  According to the corrosion suppression device 69 of the second embodiment shown in FIG. 8, the heating device 70 is provided in the storage tank 63, so that the corrosion suppression is performed as compared with the case where the heating device is provided separately from the storage tank 63. The structure of the device 69 can be simplified, the cost can be reduced, and the installation space can be reduced.

  Other than this, the configuration is the same as that of the boiler 19 with the corrosion inhibiting device of the first embodiment and acts in the same manner. Therefore, the equivalent parts are denoted by the same reference numerals and the description thereof is omitted.

  Next, 3rd Embodiment of the boiler with a corrosion inhibitor which concerns on this invention is described with reference to FIG. The difference between the boiler 72 with the corrosion inhibitory device of the third embodiment shown in FIG. 9 and the boiler 19 with the corrosion inhibitory device of the first embodiment shown in FIG. 3 is that the corrosion inhibitors 73 and 59 are different. .

  9 includes a first transport pipe 74 and a second transport pipe 75, and a base end portion of the first transport pipe 74 is provided at an outlet of the exhaust gas treatment facility 60. It is connected to the first exhaust duct 76, and the tip end portion of the first transfer pipe 74 is connected to the suction port of the transfer blower 62. And the base end part of the 2nd conveyance pipe 75 is connected to the blowing outlet of this blower 62 for conveyance, and the front-end | tip part of this 2nd conveyance pipe 75 is connected to the supply port 59a of the corrosion suppression particle | grains. One end of the supply pipe 64 is connected to the bottom of the storage tank 63 for storing the corrosion-inhibiting particles, and the other end of the supply pipe 64 is connected to the connection part 65 in the middle of the second transport pipe 75. doing.

  According to this corrosion suppression device 73, the transport blower 62 sucks innoxious combustion exhaust gas discharged from the exhaust gas treatment facility 60 through the first exhaust duct 76 and the first transport pipe 74, and sucks it. Combustion exhaust gas (conveying fluid medium) can be blown out from the outlet, and the exhausted combustion exhaust gas is supplied into the second flue 21 through the second transfer pipe 75 and the supply port 59a. At this time, the corrosion suppressing particles stored in the storage tank 63 are supplied to the second transfer pipe 75 through the supply pipe 64 by a supply device (not shown), and the supply port 59a together with the combustion exhaust gas blown out from the transfer blower 62. The corrosion-suppressing particles can be attached to the surface of the superheater tube 27 by being supplied into the second flue 21 through the surface.

  And according to this corrosion suppression apparatus 73, since the combustion exhaust gas discharged | emitted from the exhaust-gas treatment equipment 60 is used as a fluid medium for conveyance for supplying the corrosion suppression particle | grains in the 2nd flue 21, combustion is carried out. The heat of the exhaust gas can be effectively used as thermal energy for causing the corrosion-inhibiting particles to have a higher temperature than the atmosphere around the boiler 19. Therefore, the heating device 66 shown in FIG. 3 can be omitted.

  Incidentally, the temperature of the combustion exhaust gas discharged from the exhaust gas treatment facility 60 is 150 to 170 ° C., and the corrosion-inhibiting particles can be heated to 150 to 170 ° C.

  And in 3rd Embodiment shown in FIG. 9, the thermal energy which the combustion exhaust gas taken out from the exit of the exhaust gas treatment facility 60 supplies corrosion suppression particle | grains stably, for example at 150-170 degreeC from the supply port 59a. When the heat energy is insufficient or when heating to a temperature higher than that, a heating device 66 is provided in the second transport pipe 75, and the combustion exhaust gas flowing in the second transport pipe 75 is heated by the heating device 66. May be.

  Other than this, the configuration is the same as that of the boiler 19 with the corrosion inhibiting device of the first embodiment and acts in the same manner. Therefore, the equivalent parts are denoted by the same reference numerals and the description thereof is omitted.

  Next, 4th Embodiment of the boiler with a corrosion inhibitor which concerns on this invention is described with reference to FIG. The difference between the boiler 78 with a corrosion suppression device of the fourth embodiment shown in FIG. 10 and the boiler 72 with the corrosion suppression device of the third embodiment shown in FIG. 9 is that the corrosion suppression devices 79 and 73 are different. .

  10 differs from the corrosion suppression device 79 of the fourth embodiment shown in FIG. 10 in the third embodiment shown in FIG. 9 in the exhaust gas treatment in the third embodiment shown in FIG. The combustion exhaust gas discharged from the facility 60 is taken out, and the corrosion suppression particles are supplied together with the combustion exhaust gas into the second flue 21 by the conveying blower 62, whereas the fourth embodiment shown in FIG. Then, the steam is taken out from the boiler 78, and this steam is supplied into the second flue 21 by the kinetic energy of the steam together with the corrosion inhibiting particles.

  When steam is used in this way, the kinetic energy and heat energy possessed by the steam can be used effectively. And if this steam is utilized, for example, a part of the surplus steam among the steam generated in the boiler 78 can be utilized, the thermal energy possessed by the surplus steam can be used effectively, and the heating device 66 can be used. Can be omitted. Further, the transfer blower 62 can be omitted.

  Other than this, the configuration is the same as that of the boiler 72 with the corrosion inhibiting device of the third embodiment and acts in the same way, so the equivalent parts are denoted by the same reference numerals and the description thereof is omitted.

  Next, 5th Embodiment of the boiler with a corrosion inhibitor which concerns on this invention is described with reference to FIG. The difference between the boiler 81 with the corrosion suppression device of the fifth embodiment shown in FIG. 11 and the boiler 72 with the corrosion suppression device of the third embodiment shown in FIG. 9 is that the corrosion suppression devices 83 and 73 are different. .

  That is, the corrosion suppression device 73 of the third embodiment shown in FIG. 9 supplies the corrosion suppression particles stored in the storage tank 63 to the second transport pipe 75, and transports the corrosion suppression particles together with the combustion exhaust gas. 62 is supplied into the second flue 21.

  On the other hand, the corrosion suppression apparatus 83 of the fifth embodiment shown in FIG. 11 takes out the combustion ash collected by the bag filter 60a of the exhaust gas treatment facility 60 and classifies the combustion ash by the classifier 84. Then, the classified ash (corrosion-inhibiting particles) having a small and medium particle size is supplied to the second transport pipe 75, and the combustion ash (corrosion-inhibiting particles) having a small and medium particle size is supplied to the combustion exhaust gas. At the same time, the air is supplied into the second flue 21 by the conveying blower 62.

  The combustion ash (corrosion inhibiting particles) having a small and medium particle size is a combustion ash having a particle size of less than 10 μm shown in FIG. The combustion ash having a large particle diameter of 10 μm or more classified by the classifier 84 is stored in another place.

  However, in this embodiment, the combustion ash is classified from the combustion ash by the classifier 84 and the combustion ash having a small and medium particle size of less than 10 μm is used as the corrosion-inhibiting particles. Therefore, it is preferable to classify the combustion ash having a particle diameter of more than 2 μm and less than 10 μm by the classifier 84 and use the combustion ash as corrosion-inhibiting particles.

  In this way, instead of the combustion ash having a small and medium particle size of less than 10 μm, the combustion ash having a particle size of more than 2 μm and less than 10 μm is supplied into the second flue 21, thereby superheater. The progress of corrosion of the tube 27 can be effectively suppressed because the combustion ash having a small particle diameter of 0.1 μm or more and 2 μm or less shown in FIG. 5 has a strong corrosive power but a medium particle diameter. This is because combustion ash exceeding 2 μm and less than 10 μm has weak corrosive power. Therefore, by supplying combustion ash having a particle size with a weak corrosive force of more than 2 μm and less than 10 μm into the second flue 21, the corrosive force of the combustion ash generated in the boiler on the superheater tube 27 is increased. It can be effectively reduced.

  And it is good for the combustion ash as a corrosion suppression particle to make it the temperature higher than the atmosphere around a boiler using the heat which the said combustion ash holds at least. If it does in this way, the thermal energy which combustion ash holds can be used effectively, and heating device 66 can be omitted. And the cost of a corrosion suppression particle | grain can be reduced by using combustion ash as a corrosion suppression particle | grain.

  However, in the fifth embodiment shown in FIG. 11, the combustion exhaust gas discharged from the exhaust gas treatment facility 60 is taken out, and the corrosion suppression particles (combustion ash) are transported together with the combustion exhaust gas in the second flue 21 by the transport blower 62. However, instead of this, in the same manner as shown in FIG. 10, the steam is taken out from the boiler 81 and the corrosion inhibiting particles are supplied into the second flue 21 together with the steam. Good.

  When steam is used in this way, the kinetic energy and heat energy possessed by the steam can be used effectively. And if it is made to utilize, for example, a part of surplus steam among the steam generated in a boiler as this utilized steam, the thermal energy which surplus steam can be used effectively. In addition, the transfer blower 62 can be omitted.

  Except for this, the configuration is the same as that of the boiler 72 with the corrosion suppressing device of the third embodiment shown in FIG. 9 and acts in the same way, so the equivalent parts are denoted by the same reference numerals and their description is omitted.

  And in 5th Embodiment shown in FIG. 11, the thermal energy which the combustion exhaust gas taken out from the exit of the exhaust-gas treatment equipment 60 carries out the corrosion suppression particle | grains stably from 150 to 170 degreeC, for example from the supply port 59a 2nd. When the heat energy to be supplied into the flue 21 is insufficient, the heating device 66 shown in FIG. 3 is provided in the second transport pipe 75 as in the corrosion suppression device 88 of the sixth embodiment shown in FIG. The combustion exhaust gas flowing in the second transport pipe 75 may be heated by the heating device 66.

  However, the heating device 66 is provided on the upstream side of the connection portion 87 with the classification pipe 86 in the second transport pipe 75. The connection portion 87 is a connection portion between the classification pipe 86 to which the combustion ash (corrosion suppressing particles) having a small particle diameter is supplied from the classification device 84 and the second transport pipe 75. The heating device 66 is provided on the upstream side of the connecting portion 87 in the second transport pipe 75. The heating device 66 is provided on the downstream side of the connecting portion 87 in the second transport pipe 75. This is because the downstream portion of the pipe 75 may be clogged with heated combustion ash.

  Further, in the fifth embodiment shown in FIG. 11, the combustion exhaust gas discharged from the exhaust gas treatment facility 60 is taken out, and the corrosion suppression particles (combustion ash) together with the combustion exhaust gas are secondly supplied from the supply port 59 a by the transport blower 62. Instead of this, the conveying blower 62 sucks outside air (air) from the outlet, as in the corrosion suppression device 90 of the seventh embodiment shown in FIG. You may make it supply the corrosion suppression particle | grains (combustion ash) with this air in the 2nd flue 21 from the supply port 59a by blowing out the sucked air (conveyance fluid medium).

  However, in the above embodiment, as shown in FIG. 1, for example, the waste incinerator 10 is given as an example of the combustion furnace 10 of the boiler 19, but other combustion furnaces can be applied, for example, heavy oil as fuel A combustion furnace can be applied.

  And in the said embodiment, as shown in FIG. 1, although the stoker type combustion furnace was mentioned as an example as the combustion furnace 10 of the boiler 19, the combustion furnace of a format other than this can be applied, for example, A fluidized bed furnace in which fuel is burned while flowing in a fluidized bed can be applied.

  Further, in the above embodiment, the corrosion-inhibiting particles having a particle size of 0.1 μm or more and less than 10 μm are supplied into the second flue 21 upstream from the superheater tube 27. 27 may be supplied into the third flue 22 in which 27 is provided.

  And in the said embodiment, although the corrosion suppression apparatus is supplying the corrosion suppression particle | grains of temperature higher than the atmosphere around a boiler in an exhaust gas channel, what is higher temperature than the atmosphere around this boiler? For example, when the corrosion-inhibiting particles are transported and supplied into the second flue 21 using air blown from the blower outlet of the transporting blower 62, the air being heated by the blower itself is being transported by the air. Although the temperature of the corrosion-inhibiting particles may rise, it means a temperature higher than this.

  As described above, the boiler with a corrosion inhibitor and the method for inhibiting corrosion of a boiler according to the present invention have an excellent effect of effectively suppressing corrosion of a superheater tube, and are superheated like a waste incineration boiler. Suitable for boilers where corrosion of pipes is a concern.

10 Combustion furnace (garbage incinerator)
DESCRIPTION OF SYMBOLS 11 Generator 12 Hopper 13 Chute 14 Main combustion chamber 14a Ceiling 15 Dry stalker 16 Combustion stalker 17 Post combustion stalker 18 Chute 19, 68, 72, 78, 81 Boiler 20 Radiation chamber 21 2nd flue 22 3rd flue 23 Water pipe 24 Boiler drum 25 Superheater 26 Turbine 27 Superheater tube 30 Corrosion detection device 59, 69, 73, 79, 83, 88, 90 Corrosion suppression device 59a Supply port 60 Exhaust gas treatment facility 60a Bag filter 61 Conveyance tube 62 Conveyance blower 63 Storage tank 64 Supply pipe 65, 87 Connection part 66, 70 Heating device 74 1st conveyance pipe 75 2nd conveyance pipe 76 1st exhaust duct 84 Classification apparatus 86 Classification pipe 100 Control part

Claims (8)

Exhaust gas passage through which combustion exhaust gas passes,
A superheater tube provided in the exhaust gas passage;
A corrosion inhibiting device with a boiler and a corrosion inhibiting device for inhibiting the corrosion of the superheater tube corrosion inhibiting particles are supplied to said exhaust gas passage,
The corrosion-inhibiting particle is a compound having a particle size of 0.1 μm or more and less than 10 μm, the main component being at least one element of Ca, Si, Al, Mg, and Fe,
The corrosion inhibiting device, said corrosion inhibiting particles low have a predetermined temperature than the melting point of the high rather and the corrosion inhibiting particles than surrounding atmosphere of the boiler, the exhaust gas than the superheater tubes in said exhaust gas channel A boiler with a corrosion inhibitor, wherein the boiler is supplied to a region upstream of the flow direction and having a gas temperature lower than the melting point of the corrosion inhibitor particles .   The corrosion-inhibiting particles are obtained from an atmosphere around the boiler by using a heat source other than the boiler, heat held by combustion exhaust gas or combustion ash in the exhaust gas passage, or heat held by steam generated in the boiler. The boiler with a corrosion inhibitor according to claim 1, wherein the boiler is at a high temperature. The corrosion inhibitor has a heating device that heats the corrosion inhibitor particles by bringing the fluid medium for transportation higher than the predetermined temperature into contact with the corrosion inhibitor particles before being supplied into the exhaust gas passage.
The corrosion suppression device according to claim 1 or 2, wherein both the corrosion suppression particles heated by the heating device and having a temperature increased and the transporting fluid medium are supplied into the exhaust gas passage. boiler. The corrosion inhibiting system, corrosion inhibiting device with a boiler according to claim 1, wherein the supplying the corrosion inhibiting particles at a temperature of 150 to 200 ° C. in said exhaust gas channel. The corrosion inhibiting device, as the transporting fluid medium, air blown out from the transport blower, the combustion exhaust gas discharged from the boiler, or to claim 3, characterized in that utilizing the steam generated by the boiler The boiler with a corrosion inhibitor as described. The boiler with a corrosion inhibitor according to any one of claims 1 to 5 , wherein the corrosion-suppressing particles are combustion ash generated in the boiler, and the particle diameter thereof is more than 2 µm and less than 10 µm. . The corrosion inhibiting particles having a predetermined temperature and supplies than superheater tubes in the exhaust gas channel of a boiler to a upstream side of the flow direction of the exhaust gas in the region lower than the melting point of the gas temperature is the corrosion inhibiting particles, the superheater A method for inhibiting pipe corrosion ,
The corrosion-inhibiting particle is a compound having a particle size of 0.1 μm or more and less than 10 μm, the main component being at least one element of Ca, Si, Al, Mg, and Fe,
The method for inhibiting corrosion of a boiler, wherein the predetermined temperature is higher than an atmosphere around the boiler and lower than a melting point of the corrosion-inhibiting particles . Heating the corrosion-inhibiting particles by bringing the fluid medium for conveyance higher than the predetermined temperature into contact with the corrosion-inhibiting particles before being supplied into the exhaust gas passage,
Supplying both the heated corrosion-inhibiting particles and the transporting fluid medium into the exhaust gas passage;
The method for inhibiting corrosion of a boiler according to claim 7.

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