JPWO2019176119A1 - Boiler equipment and thermal power generation equipment - Google Patents

Abstract

The boiler equipment (20) includes a flow path forming equipment (21, 22) that forms a flow path through which the exhaust gas discharged after fuel is burned, and a first heat exchanger (23) arranged in the flow path. The first heat exchanger (23) is provided with a second heat exchanger (24) arranged in the flow path and arranged on the upstream side of the exhaust gas flow from the first heat exchanger (23). ) Has an outer surface having a higher acid corrosion resistance to dew condensation acid, which is an acid generated when a component contained in the exhaust gas condenses, than the second heat exchanger (24).

Description

The present invention relates to a boiler facility in which a heat exchanger is arranged in a flow path through which exhaust gas discharged after fuel is burned, and a thermal power generation facility provided with the boiler facility.

Conventionally, there is known a boiler facility (and a thermal power generation facility provided with the boiler facility) in which a heat exchanger is arranged in a flow path through which exhaust gas discharged after fuel is burned flows. For example, Patent Document 1 includes a boiler that heats water supply to generate main steam by using heat generated by combustion of fossil fuel, and a reheater (heat exchanger) installed in the boiler. The power plant is disclosed.

Japanese Unexamined Patent Publication No. 2008-248822

However, in the above-mentioned conventional boiler equipment, there is a case where the temperature of the exhaust gas that can be lowered by the heat exchanger is limited, and in this case, there is a problem that the heat in the exhaust gas cannot be effectively utilized.

The present invention has been made to solve the above problems, and an object of the present invention is to provide a boiler facility and a thermal power generation facility capable of effectively utilizing heat in exhaust gas.

In order to achieve the above object, the boiler equipment according to one aspect of the present invention includes a flow path forming facility for forming a flow path through which the exhaust gas discharged by burning fuel flows, and a first flow path forming facility arranged in the flow path. The first heat exchanger comprises one heat exchanger and a second heat exchanger arranged in the flow path and arranged upstream of the flow of the exhaust gas from the first heat exchanger. It has an outer surface having a higher acid corrosion resistance to dew condensation acid, which is an acid generated when a component contained in the exhaust gas condenses, than the second heat exchanger.

The present invention can be realized not only as such a boiler facility, but also as a thermal power generation facility provided with the boiler facility. Further, the present invention can also be realized as a control device included in the boiler equipment and a control method performed by the control device. Further, the present invention can also be realized as an integrated circuit including a characteristic processing unit included in the control device. Further, the present invention is realized as a program for causing a computer to execute a characteristic process included in the control method, or a computer-readable CD-ROM (Compact Disc-Read Only Memory) in which the program is recorded. It can also be realized as a recording medium. Then, such a program can be distributed via a recording medium such as a CD-ROM and a transmission medium such as the Internet.

According to the boiler equipment and the like in the present invention, it is possible to effectively utilize the heat in the exhaust gas.

FIG. 1 is a schematic view showing a schematic configuration of a thermal power generation facility according to an embodiment. FIG. 2 is a schematic view showing the configuration of the boiler equipment according to the embodiment. FIG. 3 is a schematic view showing the configuration of the boiler equipment according to the first modification of the embodiment. FIG. 4 is a schematic view showing the configuration of the boiler equipment according to the second modification of the embodiment.

As described above, in the above-mentioned conventional boiler equipment, the heat in the exhaust gas may not be effectively utilized. That is, when the temperature of the exhaust gas drops due to heat exchange by the heat exchanger, the components in the exhaust gas condense, but depending on the dew condensation components, the boiler equipment may be damaged due to corrosion or the like. Therefore, the temperature of the exhaust gas that can be lowered by the heat exchanger is often limited, and in this case, the heat in the exhaust gas cannot be effectively utilized.

The present invention has been made to solve the above problems, and an object of the present invention is to provide a boiler facility or the like capable of effectively utilizing heat in exhaust gas.

In order to achieve the above object, the boiler equipment according to one aspect of the present invention includes a flow path forming facility for forming a flow path through which the exhaust gas discharged by burning fuel flows, and a first flow path forming facility arranged in the flow path. The first heat exchanger comprises one heat exchanger and a second heat exchanger arranged in the flow path and arranged upstream of the flow of the exhaust gas from the first heat exchanger. It has an outer surface having a higher acid corrosion resistance to dew condensation acid, which is an acid generated when a component contained in the exhaust gas condenses, than the second heat exchanger.

According to this, the boiler equipment is provided with a first heat exchanger and a second heat exchanger on the upstream side of the exhaust gas from the first heat exchanger in the flow path of the exhaust gas, and the first heat exchange The vessel has an outer surface that has higher acid corrosion resistance to dew condensation acid, which is an acid generated when a component contained in the exhaust gas condenses, than the second heat exchanger. That is, the exhaust gas flows from the upstream in the order of the second heat exchanger and the first heat exchanger, and when it reaches the first heat exchanger, the temperature drops, so that the first heat exchanger The acid corrosion resistance of the outer surface is made higher than that of the second heat exchanger. As a result, even when the temperature of the exhaust gas is lowered and the dew condensation acid is generated, it is possible to suppress the corrosion of the first heat exchanger by the dew condensation acid, so that the temperature of the exhaust gas can be lowered. As described above, it is not necessary to limit the temperature of the exhaust gas that can be lowered by the heat exchanger, and the temperature of the exhaust gas can be lowered, so that the heat in the exhaust gas can be effectively utilized.

Further, the first heat exchanger may have a main body portion and a paint which is arranged on the surface of the main body portion and has higher acid corrosion resistance to the dew condensation acid than the main body portion.

According to this, in the first heat exchanger, a paint having high acid corrosion resistance against dew condensation acid is provided on the surface of the main body portion. By providing (applying) the paint having high acid corrosion resistance on the surface of the main body of the first heat exchanger in this way, the outer surface having high acid corrosion resistance can be easily formed.

Further, the first heat exchanger may be arranged at a position in the flow path that is equal to or lower than the dew point temperature of the dew condensation acid.

According to this, the first heat exchanger is arranged at a position in the flow path of the exhaust gas that is equal to or lower than the dew point temperature of the dew condensation acid. Here, if the exhaust gas can be condensed, the latent heat of vaporization of the components contained in the exhaust gas can be recovered, so that the exhaust heat recovery efficiency can be significantly improved. Therefore, by arranging the first heat exchanger in the flow path of the exhaust gas at a position below the dew point temperature, the latent heat of vaporization in the exhaust gas can be recovered by the first heat exchanger, so that the latent heat of vaporization in the exhaust gas can be recovered. Effective use of heat can be achieved.

Further, the first heat exchanger has a first pipe through which the heat medium flows, and a second pipe arranged on the upstream side of the exhaust gas flow from the first pipe and through which the heat medium flows. The first pipe may have an outer surface having a higher acid corrosion resistance to the dew condensation acid than the second pipe.

According to this, the first heat exchanger has a first pipe and a second pipe on the upstream side of the exhaust gas from the first pipe, and the first pipe has more dew condensation acid than the second pipe. It has an outer surface that is highly resistant to acid corrosion. That is, the exhaust gas flows in the order of the second pipe and the first pipe from the upstream, and the temperature drops when the exhaust gas reaches the first pipe. Therefore, the acid corrosion resistance of the outer surface of the first pipe is improved. Make it higher than two pipes. As a result, even when the temperature of the exhaust gas is lowered and the dew condensation acid is generated, it is possible to suppress the corrosion of the first pipe by the dew condensation acid, so that the temperature of the exhaust gas can be lowered. As described above, it is not necessary to limit the temperature of the exhaust gas that can be lowered by the heat exchanger, and the temperature of the exhaust gas can be lowered, so that the heat in the exhaust gas can be effectively utilized.

Further, the flow path forming facility may be formed with a discharge port for discharging the dew condensation acid.

According to this, the flow path forming facility for forming the flow path of the exhaust gas is formed with a discharge port for discharging the dew condensation acid. As a result, even when the temperature of the exhaust gas is lowered and the dew condensation acid is generated, the dew condensation acid can be discharged from the discharge port, so that the flow path forming equipment can be suppressed from being corroded by the dew condensation acid.

Further, a pipe connecting the discharge port and the wastewater treatment facility may be provided.

According to this, the boiler equipment is provided with a pipe connecting the dew condensation acid discharge port formed in the flow path forming equipment and the wastewater treatment equipment. As a result, even when the temperature of the exhaust gas is lowered and the dew condensation acid is generated, the dew condensation acid can be sent to the wastewater treatment facility via the pipe, so that the dew condensation acid can be treated.

Further, the flow path forming facility may have a bottom surface on which an inclined surface inclined toward the discharge port is formed.

According to this, an inclined surface inclined toward the dew condensation acid discharge port is formed on the bottom surface of the flow path forming facility. As a result, even when the temperature of the exhaust gas drops and dew condensation acid is generated, the dew condensation acid can be easily discharged from the discharge port, so that the flow path forming equipment can be suppressed from being corroded by the dew condensation acid. it can.

Further, the inclined surface may be arranged on the downstream side of the flow of the exhaust gas from the first heat exchanger.

According to this, the inclined surface formed on the bottom surface of the flow path forming facility is arranged on the downstream side of the exhaust gas from the first heat exchanger. Here, when the temperature of the exhaust gas drops in the first heat exchanger and dew condensation acid is generated, the dew condensation acid rides on the flow of the exhaust gas and is located downstream of the exhaust gas from the first heat exchanger. Scatter. Therefore, in the flow path forming facility, since the inclined surface is formed on the downstream side of the exhaust gas from the first heat exchanger, the dew condensation acid scattered on the downstream side of the exhaust gas can be dropped on the inclined surface. it can. As a result, the dew condensation acid can be guided to the discharge port along the inclined surface, so that the dew condensation acid can be easily discharged from the discharge port, and the flow path forming equipment is suppressed from being corroded by the dew condensation acid. Can be done.

Further, the inclined surface may have higher acid corrosion resistance to the dew condensation acid than other parts of the flow path forming facility.

According to this, the inclined surface formed on the bottom surface of the flow path forming facility has higher acid corrosion resistance to dew condensation acid than other parts of the flow path forming facility. That is, since the inclined surface is a portion that becomes a flow path of the dew condensation acid and is in contact with the dew condensation acid for a relatively long time, the acid corrosion resistance of the inclined surface is enhanced. As a result, even when the temperature of the exhaust gas is lowered and dew condensation acid is generated, it is possible to prevent the inclined surface from being corroded by the dew condensation acid.

Further, a control device for controlling the flow of the heat medium in the first heat exchanger is provided, and in the control device, the temperature of the heat medium at the inlet of the first heat exchanger is the dew point of the dew condensation acid. Even when the temperature drops below the temperature, the heat medium may be allowed to flow in the first heat exchanger without heating.

According to this, the control device installed in the boiler equipment keeps the heat medium in the first heat exchanger even when the temperature of the heat medium at the inlet of the first heat exchanger becomes equal to or lower than the dew point temperature of the dew condensation acid. Control the flow of the heat medium so that it flows without heating. That is, when the temperature of the heat medium at the inlet of the first heat exchanger is lowered because the first heat exchanger has an outer surface having higher acid corrosion resistance to dew condensation acid than the second heat exchanger. However, the heat medium can be flowed into the first heat exchanger without heating the heat medium. As described above, since the control device does not need to control the heating of the heat medium, the control process can be simplified.

Further, the flow path forming facility forms a flow path in the exhaust heat recovery boiler through which the exhaust gas discharged from the gas turbine flows, and the first heat exchanger is an economizer in the exhaust heat recovery boiler. You may.

According to this, the flow path forming facility forms a flow path in the exhaust heat recovery boiler through which the exhaust gas from the gas turbine flows, and the first heat exchanger is an economizer in the exhaust heat recovery boiler. As described above, the present invention can be applied to a boiler facility provided with an exhaust heat recovery steam generator.

Hereinafter, the boiler equipment and the thermal power generation equipment according to the embodiment and its modification will be described with reference to the drawings. It should be noted that the embodiments and modifications thereof described below are all comprehensive or specific examples. Numerical values, shapes, materials, components, arrangement positions and connection forms of components, control processing, order of control processing, etc. shown in the following embodiments and modifications thereof are examples, and the gist of limiting the present invention. is not. Further, among the components in the following embodiments and modifications thereof, the components not described in the independent claims indicating the highest level concept will be described as arbitrary components.

(Embodiment)
[1 Explanation of the configuration of thermal power generation equipment]
First, the schematic configuration of the thermal power generation facility 1 will be described. FIG. 1 is a schematic view showing a schematic configuration of a thermal power generation facility 1 according to the present embodiment.

The thermal power generation facility 1 is a power generation facility that burns fossil fuels to generate power. As shown in FIG. 1, a gas turbine 10, a boiler facility 20, a steam turbine 30, a generator 40, a chimney 50, and wastewater treatment. It is equipped with equipment 60 and the like. That is, the thermal power generation facility 1 is a combined cycle power generation type thermal power plant in the present embodiment. Further, the thermal power generation facility 1 further includes a control device 2. Each of these components will be specifically described below.

The gas turbine 10 includes an air compressor 11, a combustor 12, and a turbine 13. With this configuration, the gas turbine 10 compresses the sucked air into high-pressure air by the air compressor 11, and injects fuel such as NG (natural gas) into the high-pressure air by the combustor 12 to burn it. NG can be obtained by vaporizing LNG (liquefied natural gas) stored in a tank (not shown). Then, the combustion gas that has become high temperature and high pressure rotates the turbine 13. As a result, the gas turbine 10 applies a rotational force to the generator 40 to generate electric power. The turbine 13 also applies a rotational force to the air compressor 11. Then, the combustion gas that rotates the turbine 13 is discharged to the boiler equipment 20.

The boiler equipment 20 includes a first flow path forming facility 21, a second flow path forming facility 22, a first heat exchanger 23, and a second heat exchanger 24. The first flow path forming facility 21 and the second flow path forming facility 22 are facilities for forming a flow path through which the exhaust gas (exhaust gas g in FIG. 1) discharged by burning fuel in the gas turbine 10 flows. The first heat exchanger 23 and the second heat exchanger 24 are facilities that are arranged in the flow path and exchange heat between the heat medium flowing inside and the heat of the exhaust gas g.

As described above, the boiler facility 20 is a facility provided with an exhaust heat recovery boiler (HRSG) that recovers the heat of the exhaust gas discharged from the gas turbine 10. That is, the first flow path forming facility 21 and the second flow path forming facility 22 are facilities for forming a flow path in the exhaust heat recovery boiler through which the exhaust gas g discharged from the gas turbine 10 flows. Specifically, the first flow path forming facility 21 is a body portion of the exhaust heat recovery boiler, and the second flow path forming facility 22 is a flue portion. That is, the first flow path forming facility 21 is a portion that accommodates the first heat exchanger 23 and the second heat exchanger 24, and the second flow path forming facility 22 has the first flow path forming facility 21 and the chimney 50. This is the part to connect.

Further, the first heat exchanger 23 is a heat exchanger arranged on the downstream side of the flow of the exhaust gas g from the second heat exchanger 24, and is an economizer in the exhaust heat recovery boiler. Further, the second heat exchanger 24 is a heat exchanger arranged on the upstream side of the flow of the exhaust gas g with respect to the first heat exchanger 23, and is an evaporator or a superheater in the exhaust heat recovery boiler. If the second heat exchanger 24 is arranged on the upstream side of the flow of the exhaust gas g rather than the first heat exchanger 23, the first heat exchanger 23 and the second heat exchanger 24 may be used. It is not limited to economizers and evaporators or superheaters.

Here, the first heat exchanger 23 and the second heat exchanger 24 cool the exhaust gas g flowing from the gas turbine 10 toward the chimney 50 and heat the heat medium flowing inside. For example, as the first heat exchanger 23 and the second heat exchanger 24, a heater that cools the exhaust gas g and heats the heat medium by flowing the heat medium through the pipe and passing the exhaust gas g around the heat medium. (Heat exchanger) can be used. In the present embodiment, the heat medium is water (pure water), but it may be a liquid other than water (pure water) or a gas such as steam.

In this way, the exhaust gas g is cooled by the second heat exchanger 24 and the first heat exchanger 23, so that the first heat exchanger 23 on the downstream side is the exhaust gas g formed by the first flow path forming facility 21. It is arranged at a position below the dew point temperature of the dew condensation acid in the flow path of. Here, the dew-condensing acid is an acid generated when a component contained in the exhaust gas g condenses. For example, the components contained in the exhaust gas g are sulfur contained in the fossil fuel, NOx and CO ₂ generated by burning the fossil fuel, ammonia injected from the denitration device, and the dew condensation acid. , Sulfuric acid, nitric acid, carbon dioxide, ammonium sulfate and the like obtained by combining various components in the exhaust gas g containing these components and forming dew. The first heat exchanger 23 does not have to be entirely arranged at a position below the dew point temperature of the dew condensation acid, and at least a part thereof is arranged at a position below the dew point temperature of the dew condensation acid. I just need to be there. Further, the first heat exchanger 23 does not have to be always arranged at a position below the dew point temperature of the dew condensation acid, and may be temporarily arranged at a position below the dew point temperature of the dew condensation acid. Just do it.

For this reason, the first heat exchanger 23 has an outer surface having a higher acid corrosion resistance to the dew condensation acid than the second heat exchanger 24. In the present embodiment, the first heat exchanger 23 is configured to have an outer surface having a high acid corrosion resistance to the dew condensation acid by applying a paint having a high acid corrosion resistance to the dew condensation acid. That is, the first heat exchanger 23 has a main body portion and a paint that is arranged on the surface of the main body portion and has higher acid corrosion resistance to the dew condensation acid than the main body portion.

The paint having high acid corrosion resistance to dew condensation acid means a paint having higher acid corrosion resistance to dew condensation acid than the base material when applied to the base material. As such a paint, a paint containing any component may be used. For example, as the paint, acid resistance can be prevented by returning (rusting) the iron surface to an oxide or the like. Reactive paints can be used. That is, the base material of the first heat exchanger 23 and the second heat exchanger 24 is formed of, for example, a carbon steel material (carbon steel pipe), and the above-mentioned paint is applied to the outer surface of the base material of the first heat exchanger 23. Therefore, the first heat exchanger 23 can be configured to have an outer surface having a higher acid corrosion resistance to dew condensation acid than the second heat exchanger 24.

With the above configuration, a heat medium such as water (pure water) is supplied to the first heat exchanger 23 from the water supply pipe 32 described later, and the heat medium is the first heat exchanger 23 and the second heat exchanger. It flows through the 24 and is heated by the exhaust gas g discharged from the gas turbine 10. Then, the heated heat medium becomes a high-temperature heat medium such as steam, and is supplied to the steam turbine 30 through the steam pipes 34 and 35. Further, the exhaust gas g discharged from the gas turbine 10 is discharged from the chimney 50 through the second flow path forming facility 22 after heating the heat medium in the second heat exchanger 24 and the first heat exchanger 23. Will be done. By the time the exhaust gas g is discharged from the chimney 50, unnecessary substances are removed by a denitration device or the like (not shown). A more detailed description of the configuration of the boiler equipment 20 will be described later.

The steam turbine 30 is a turbine to which steam generated by the boiler equipment 20 is supplied and driven (rotated) by the energy of the steam. That is, steam is supplied from the first heat exchanger 23 and the second heat exchanger 24 to the steam turbine 30 through the steam pipes 34 and 35, and the turbine is driven. The configuration of the steam turbine 30 is not particularly limited, and it may be composed of one turbine, or may have a plurality of turbines such as a high-pressure turbine, a medium-pressure turbine, and a low-pressure turbine. Further, the steam discharged from the steam turbine 30 is sent to the condenser 31, and is cooled by the condenser 31 by a cooling source such as seawater or a river to become water. Then, the water is sent to the first heat exchanger 23 of the boiler equipment 20 as the above-mentioned heat medium through the water supply pipe 32 by the condensate pump 33.

The generator 40 is a generator that generates electricity by the gas turbine 10 and the steam turbine 30. That is, the generator 40 is coaxially connected to the gas turbine 10 and the steam turbine 30, and when the gas turbine 10 and the steam turbine 30 rotate, the generator 40 rotates and power is generated. As described above, the generator 40 is a turbine generator that generates electricity by converting the rotational force of the gas turbine 10 and the steam turbine 30 into electric power.

The wastewater treatment facility 60 is a facility that treats the waste liquid discharged from the boiler facility 20 via the discharge pipe 61. Here, the drainage liquid discharged from the boiler equipment 20 is the above-mentioned dew condensation acid. Specifically, the second flow path forming facility 22 of the boiler facility 20 is formed with a discharge port 22a for discharging the dew condensation acid, and the discharge pipe 61 is connected to the discharge port 22a and the wastewater treatment facility 60. The discharge port 22a and the wastewater treatment facility 60 are connected to each other. A valve for stopping the flow of dew condensation acid, a valve for adjusting the flow rate of dew condensation acid, a pump for sending dew condensation acid, or the like may be provided in the middle of the discharge pipe 61.

Further, the wastewater treatment facility 60 is also connected to other facilities in the thermal power generation facility 1 by a discharge pipe 62, and is configured to treat various waste liquids discharged from the other facilities via the discharge pipe 62. It has become. That is, the waste liquid (condensable acid) discharged from the boiler facility 20 is treated by utilizing the wastewater treatment facility 60 used for the wastewater treatment of the entire thermal power generation facility 1. The wastewater treatment facility 60 may be a dedicated wastewater treatment facility for treating the waste liquid (condensable acid) discharged from the boiler facility 20.

The control device 2 is a computer (processor) that controls the flow of the heat medium in the first heat exchanger 23. Specifically, the control device 2 controls the flow rate and flow velocity of the heat medium supplied from the water supply pipe 32 to the first heat exchanger 23 and flowing in the first heat exchanger 23 and the second heat exchanger 24. To do. The control device 2 also has a function of controlling the operation of other equipment in the thermal power generation equipment 1. That is, the control device 2 is a device that controls the operation of the entire thermal power generation facility 1. The control device 2 may be a dedicated control device for controlling the flow of the heat medium in the first heat exchanger 23.

More specifically, in the control device 2, even when the temperature of the heat medium at the inlet of the first heat exchanger 23 (first heat exchanger inlet 23p) becomes equal to or lower than the dew point temperature of the dew condensation acid, the first heat The heat medium is controlled to flow into the exchanger 23 without heating. That is, the control device 2 recirculates the heat medium and reduces the flow rate and flow velocity of the heat medium even when the temperature of the heat medium at the first heat exchanger inlet 23p becomes equal to or lower than the dew point temperature of the dew condensation acid. , Do not heat the heat medium by stopping the flow of the heat medium. As a result, the temperature of the heat medium at the inlet 23p of the first heat exchanger drops below the dew point temperature of the dew condensation acid, so that the first heat exchanger 23 is arranged at a position below the dew point temperature of the dew condensation acid. It becomes.

[2 Detailed explanation of the configuration of boiler equipment]
Next, the configuration of the boiler equipment 20 will be described in more detail. FIG. 2 is a schematic view showing the configuration of the boiler equipment 20 according to the present embodiment.

As shown in FIG. 2, the first heat exchanger 23 has a first pipe 23a and a second pipe 23b. The first pipe 23a is arranged on the downstream side of the flow of the exhaust gas g with respect to the second pipe 23b, and is a pipe through which the heat medium supplied from the water supply pipe 32 flows. The second pipe 23b is arranged on the upstream side of the flow of the exhaust gas g with respect to the first pipe 23a, and is a pipe through which the heat medium supplied from the first pipe 23a flows. The lengths of the first pipe 23a and the second pipe 23b are not particularly limited, but in the present embodiment, the first pipe 23a and the second pipe 23b have the same length.

The first pipe 23a has an outer surface having a higher acid corrosion resistance to dew condensation acid than the second pipe 23b. Specifically, as described above, the first pipe 23a has an outer surface having a high acid corrosion resistance to the dew condensation acid by applying a paint having a high acid corrosion resistance to the dew condensation acid. That is, the first pipe 23a has a main body portion and a paint which is arranged on the surface of the main body portion and has high acid corrosion resistance to the dew condensation acid. Specifically, the base material of the first pipe 23a and the second pipe 23b is formed of, for example, a carbon steel material (carbon steel pipe), and the above-mentioned paint is applied to the outer surface of the base material of the first pipe 23a. The one pipe 23a is configured to have an outer surface having a higher acid corrosion resistance to dew condensation acid than the second pipe 23b.

As described above, in the present embodiment, the first heat exchanger 23 has a second heat exchanger 23a having an outer surface having a higher acid corrosion resistance to dew condensation acid than the second heat exchanger 24. It has a structure having an outer surface having a higher acid corrosion resistance to dew condensation acid than the exchanger 24. The second pipe 23b may have an acid corrosion resistance to dew condensation acid equal to or lower than that of the second heat exchanger 24, but higher than that of the second heat exchanger 24. Is preferable. That is, it is preferable that the second heat exchanger 24, the second pipe 23b, and the first pipe 23a have higher acid corrosion resistance to dew condensation acid in this order.

Further, as described above, the second flow path forming facility 22 is formed with a discharge port 22a connected to the discharge pipe 61 to discharge the dew condensation acid, but the second flow path forming facility 22 further includes. It has a bottom surface on which an inclined surface 22b inclined toward the discharge port 22a is formed. That is, the discharge port 22a and the inclined surface 22b are arranged on the downstream side of the flow of the exhaust gas g from the first heat exchanger 23.

The inclined surface 22b is an inclined surface formed on the bottom surface arranged at the lowest position of the second flow path forming facility 22, and specifically, is arranged on the chimney 50 side of the second flow path forming facility 22. It is an inclined surface formed on the bottom surface. That is, the discharge port 22a is also formed on the bottom surface of the second flow path forming facility 22 on the chimney 50 side, which is arranged at the lowest position of the second flow path forming facility 22. Further, the inclined surface 22b is a surface in which the portion around the discharge port 22a on the bottom surface is inclined downward toward the discharge port 22a, and has a conical shape (mortar shape). The shape of the inclined surface 22b is not particularly limited, and may be, for example, a shape recessed in a pyramid shape, or a groove whose bottom is inclined toward the discharge port 22a may be formed on the bottom surface.

Further, in the second flow path forming facility 22, the inclined surface 22c is further arranged on the upstream side of the flow of the exhaust gas g with respect to the inclined surface 22b. The inclined surface 22c is an inclined surface formed on the bottom surface arranged at a position higher than the inclined surface 22b, and specifically, is arranged on the first flow path forming facility 21 side of the second flow path forming facility 22. It is an inclined surface formed on the bottom surface. Similar to the inclined surface 22b, the inclined surface 22c is also an inclined surface that is arranged on the downstream side of the flow of the exhaust gas g from the first heat exchanger 23 and is inclined toward the discharge port 22a.

Further, the inclined surfaces 22b and 22c are formed to have higher acid corrosion resistance to dew condensation acid than other parts of the second flow path forming facility 22. That is, the inclined surfaces 22b and 22c are configured to have high acid corrosion resistance to dew condensation acid by applying a paint having high acid corrosion resistance to dew condensation acid, similarly to the first heat exchanger 23. .. Specifically, the second flow path forming facility 22 is formed of, for example, a carbon steel material (carbon steel plate), and the above-mentioned paint is applied to the inclined surfaces 22b and 22c so that the inclined surfaces 22b and 22c become other parts. It can be configured to have higher acid corrosion resistance to dew condensation acid than.

[3 Explanation of effect]
As described above, according to the boiler equipment 20 according to the present embodiment, the first heat exchanger 23 and the second heat exchanger 23 on the upstream side of the exhaust gas g are in the flow path of the exhaust gas g. A heat exchanger 24 is provided, and the first heat exchanger 23 has more acid corrosion resistance to dew condensation acid, which is an acid generated when a component contained in the exhaust gas g condenses, than the second heat exchanger 24. It has a high outer surface. Here, in general, the second heat exchanger 24 on the upstream side is in a higher temperature and high pressure environment than the first heat exchanger 23 on the downstream side, so that the second heat exchanger 24 is used for high temperature and high pressure. Although piping made of the same material as above is used, the material for high temperature and high pressure usually has relatively high acid corrosion resistance. Therefore, in general, the second heat exchanger 24 has higher acid corrosion resistance to dew condensation acid than the first heat exchanger 23. However, since the exhaust gas g flows in the order of the second heat exchanger 24 and the first heat exchanger 23 from the upstream, the temperature drops when the first heat exchanger 23 is reached. The heat exchanger 23 is easily corroded. Therefore, in the boiler equipment 20 according to the present embodiment, the acid corrosion resistance of the outer surface of the first heat exchanger 23 is made higher than that of the second heat exchanger 24. As a result, even when the temperature of the exhaust gas g is lowered to generate dew condensation acid, the first heat exchanger 23 can be suppressed from being corroded by the dew condensation acid, so that the temperature of the exhaust gas g can be lowered. it can. As described above, it is not necessary to limit the temperature of the exhaust gas g that can be lowered by the heat exchanger, and the temperature of the exhaust gas g can be lowered, so that the heat in the exhaust gas g can be effectively utilized. As a result, the power generation efficiency of the thermal power generation facility 1 can be improved.

Further, the first heat exchanger 23 is provided with a paint having high acid corrosion resistance against dew condensation acid on the surface of the main body portion. By providing (applying) the paint having high acid corrosion resistance on the surface of the main body of the first heat exchanger 23 in this way, the outer surface having high acid corrosion resistance can be easily formed.

Further, the first heat exchanger 23 is arranged at a position in the flow path of the exhaust gas g that is equal to or lower than the dew point temperature of the dew condensation acid. Here, if the exhaust gas g can be condensed, the latent heat of vaporization of the components contained in the exhaust gas g can be recovered, so that the exhaust heat recovery efficiency can be significantly improved. Therefore, by arranging the first heat exchanger 23 in the flow path of the exhaust gas g at a position below the dew point temperature, the latent heat of vaporization in the exhaust gas g can be recovered by the first heat exchanger 23. , It is possible to effectively utilize the heat in the exhaust gas g.

Further, the first heat exchanger 23 has a first pipe 23a and a second pipe 23b on the upstream side of the exhaust gas g from the first pipe 23a, and the first pipe 23a is from the second pipe 23b. Also has an outer surface that is highly resistant to acid corrosion against dew condensation. That is, the exhaust gas g flows in the order of the second pipe 23b and the first pipe 23a from the upstream, and the temperature drops when the exhaust gas g reaches the first pipe 23a. Therefore, the acid resistance of the outer surface of the first pipe 23a. The corrosiveness is made higher than that of the second pipe 23b. As a result, even when the temperature of the exhaust gas g is lowered and the dew condensation acid is generated, it is possible to suppress the corrosion of the first pipe 23a by the dew condensation acid, so that the temperature of the exhaust gas g can be lowered. As described above, it is not necessary to limit the temperature of the exhaust gas g that can be lowered by the heat exchanger, and the temperature of the exhaust gas g can be lowered, so that the heat in the exhaust gas g can be effectively utilized.

Further, the flow path forming facility (second flow path forming facility 22) that forms the flow path of the exhaust gas g is formed with a discharge port 22a for discharging the dew condensation acid. As a result, even when the temperature of the exhaust gas g is lowered and the dew condensation acid is generated, the dew condensation acid can be discharged from the discharge port 22a, so that the flow path forming equipment can be suppressed from being corroded by the dew condensation acid. it can.

Further, the boiler facility 20 includes a discharge pipe 61 that connects the dew condensation acid discharge port 22a formed in the flow path forming facility (second flow path forming facility 22) and the wastewater treatment facility 60. As a result, even when the temperature of the exhaust gas g is lowered and the dew condensation acid is generated, the dew condensation acid can be sent to the wastewater treatment facility 60 via the discharge pipe 61, so that the dew condensation acid can be treated. ..

Further, on the bottom surface of the flow path forming facility (second flow path forming facility 22), inclined surfaces 22b and 22c inclined toward the dew condensation acid discharge port 22a are formed. As a result, even when the temperature of the exhaust gas g is lowered and the dew condensation acid is generated, the dew condensation acid can be easily discharged from the discharge port 22a, so that the flow path forming equipment is suppressed from being corroded by the dew condensation acid. be able to.

Further, the inclined surfaces 22b and 22c formed on the bottom surface of the flow path forming facility (second flow path forming facility 22) are arranged on the downstream side of the exhaust gas g from the first heat exchanger 23. Here, when the temperature of the exhaust gas g is lowered in the first heat exchanger 23 to generate dew condensation acid, the dew condensation acid rides on the flow of the exhaust gas g and exhaust gas more than the first heat exchanger 23. It scatters on the downstream side of g. Therefore, in the flow path forming facility, the inclined surfaces 22b and 22c are formed on the downstream side of the exhaust gas g from the first heat exchanger 23, so that the dew condensation acid scattered on the downstream side of the exhaust gas g is discharged on the inclined surface. It can be dropped on 22b, 22c. As a result, the dew condensation acid can be guided to the discharge port 22a along the inclined surfaces 22b and 22c, so that the dew condensation acid can be easily discharged from the discharge port 22a, and the flow path forming facility is corroded by the dew condensation acid. Can be suppressed.

Further, the inclined surfaces 22b and 22c formed on the bottom surface of the flow path forming facility (second flow path forming facility 22) have higher acid corrosion resistance to dew condensation acid than other parts of the flow path forming facility. That is, since the inclined surfaces 22b and 22c are portions that serve as a flow path for the dew condensation acid and are in contact with the dew condensation acid for a relatively long time, the acid corrosion resistance of the inclined surfaces 22b and 22c is enhanced. As a result, even when the temperature of the exhaust gas g is lowered and the dew condensation acid is generated, it is possible to prevent the inclined surfaces 22b and 22c from being corroded by the dew condensation acid.

Further, in the control device 2 provided in the boiler equipment 20, even when the temperature of the heat medium at the first heat exchanger inlet 23p becomes equal to or lower than the dew point temperature of the dew condensation acid, the heat medium is contained in the first heat exchanger 23. Control the flow of the heat medium so that it flows without heating. That is, since the first heat exchanger 23 has an outer surface having a higher acid corrosion resistance to dew condensation acid than the second heat exchanger 24, the temperature of the heat medium at the first heat exchanger inlet 23p becomes lower. Even in this case, the heat medium can be passed through the first heat exchanger 23 without heating the heat medium. As described above, since the control device 2 does not need to control the heating of the heat medium, the control process can be simplified. Further, since it is not necessary to provide equipment such as a pipe and a control valve for heating the heat medium, the configuration of the boiler equipment 20 can be simplified.

Further, the flow path forming facility (second flow path forming facility 22) forms a flow path in the exhaust heat recovery boiler through which the exhaust gas g from the gas turbine 10 flows, and the first heat exchanger 23 is in the exhaust heat recovery boiler. It is an economizer. As described above, the present invention can be applied to the boiler equipment 20 provided with the exhaust heat recovery steam generator.

Further, the boiler equipment 20 having the above configuration is simply modified by applying a paint having high acid corrosion resistance to dew condensation acid to the boiler equipment 20 of the existing power plant and adding a discharge pipe 61. By doing so, it can be realized. Further, even when a thermal power plant is newly constructed, the boiler equipment 20 having the above configuration can be easily constructed because the configuration is simple.

[4 Description of modified example]
(Modification example 1)
Next, a modification 1 of the above embodiment will be described. FIG. 3 is a schematic view showing the configuration of the boiler equipment 20A according to the first modification of the present embodiment.

As shown in FIG. 3, the boiler equipment 20A according to the present modification has a flat surface 22d instead of the discharge port 22a and the inclined surface 22b in the boiler equipment 20 of the above embodiment, and replaces the inclined surface 22c. , Has a discharge port 22e and an inclined surface 22f. That is, in the present modification, the discharge port 22a and the sloped surface 22f having the same configuration as the discharge port 22a and the sloped surface 22b of the above embodiment are provided at the position of the inclined surface 22c in the above-described embodiment. Since the other configurations are the same as those in the above embodiment, detailed description thereof will be omitted.

As described above, according to the boiler equipment 20A according to the present modification, the same effect as that of the above embodiment can be obtained. In particular, in this modification, the dew condensation acid generated in the first flow path forming facility 21 can be discharged to the wastewater treatment facility 60 without flowing to the wake.

In this modification, the discharge port 22a and the inclined surface 22b similar to those in the above embodiment may be formed at the position of the flat surface 22d. As a result, the dew condensation acid that could not be discharged from the discharge port 22e and flowed to the wake from the inclined surface 22f can also be discharged to the wastewater treatment facility 60.

(Modification 2)
Next, a modification 2 of the above embodiment will be described. FIG. 4 is a schematic view showing the configuration of the boiler equipment 20B according to the second modification of the present embodiment.

As shown in FIG. 4, the boiler equipment 20B according to the present modification uses the flow path forming equipment 25 instead of the first flow path forming equipment 21 and the second flow path forming equipment 22 in the boiler equipment 20 of the above embodiment. I have. That is, the boiler equipment 20B of the present modification is not provided with a vertical exhaust heat recovery boiler as in the above embodiment, but is provided with a horizontal exhaust heat recovery boiler. Therefore, the first heat exchanger 23 and the second heat exchanger 24 are also arranged according to the horizontal type, and the discharge port 25a and the inclined surface 25b are formed on the bottom surface of the flow path forming facility 25 on the chimney 50 side. ing.

The discharge port 25a and the inclined surface 25b are arranged on the downstream side of the flow of the exhaust gas g from the first heat exchanger 23, as in the above embodiment, and the inclined surface 25b is inclined toward the discharge port 25a. It is a sloped surface. Further, the inclined surface 25b is formed to have higher acid corrosion resistance to dew condensation acid than other parts of the flow path forming facility 25, as in the above embodiment. Since the other configurations are the same as those in the above embodiment, detailed description thereof will be omitted.

As described above, according to the boiler equipment 20B according to the present modification, the same effect as that of the above embodiment can be obtained. In particular, in this modification, it is not necessary to provide equipment corresponding to the second flow path forming equipment 22 in the above embodiment, so that the boiler equipment 20B can be easily configured.

The shape of the exhaust heat recovery boiler provided in the boiler equipment may be an L-shape or the like in which the above-mentioned vertical type and horizontal type are combined. In this case, the first heat exchanger 23 and the second heat exchanger 24 may be arranged in any part of the L-shape, and the first heat exchanger 23 or the second heat exchanger 24 is L-shaped. It may have the shape of a mold. That is, if the first heat exchanger 23 is arranged on the downstream side of the flow of the exhaust gas g from the second heat exchanger 24, which of the first heat exchanger 23 and the second heat exchanger 24 is It may be arranged at such a position, or may be configured in any shape.

(Other variants)
Although the boiler equipment and the thermal power generation equipment according to the present embodiment and its modified examples have been described above, the present invention is not limited to the above-described embodiment and its modified examples. That is, it should be considered that the embodiments disclosed this time and examples thereof are examples in all respects and are not restrictive. The scope of the present invention is shown by the claims rather than the above description, and it is intended that all modifications within the meaning and scope equivalent to the claims are included.

For example, in the above embodiment and its modification, the first heat exchanger 23 is coated with a paint having high acid corrosion resistance against dew condensation acid, and the second heat exchanger 24 is not coated with the paint. It was decided that the heat exchanger 23 has higher acid corrosion resistance to dew condensation acid than the second heat exchanger 24. However, the second heat exchanger 24 is also coated with a paint having a high acid corrosion resistance to dew condensation acid, and the first heat exchanger 23 is also coated with a paint having a higher acid corrosion resistance to dew condensation acid. The first heat exchanger 23 may have higher acid corrosion resistance to dew condensation acid than the second heat exchanger 24. Further, the first heat exchanger 23 (or the second heat exchanger 24) is not coated with the paint, but is formed of a material having high acid corrosion resistance against dew condensation acid such as stainless steel. You may decide.

Further, in the above-described embodiment and its modification, a part (first pipe 23a) of the first heat exchanger 23 is formed to have high acid corrosion resistance to dew condensation acid. However, all of the first heat exchanger 23 (first pipe 23a and second pipe 23b) may be formed to have high acid corrosion resistance to dew condensation acid.

Further, in the above-described embodiment and its modified example, it is assumed that the flow path forming facility is formed with a discharge port for discharging the dew condensation acid. However, the discharge port is not formed in the flow path forming facility, and the dew condensation acid may be discharged by pumping the dew condensation acid with a pump or the like.

Further, in the above-described embodiment and its modification, it is assumed that a paint having high acid corrosion resistance against dew condensation acid is applied to the inclined surface of the flow path forming facility. However, the bottom surface of the flow path forming facility on which the inclined surface is formed may be made of a material having high acid corrosion resistance to dew condensation acid such as stainless steel. Alternatively, the inclined surface of the flow path forming facility may have the same acid corrosion resistance to dew condensation acid as other parts of the flow path forming facility.

Further, in the above-described embodiment and its modification, the control device 2 is inside the first heat exchanger 23 even when the temperature of the heat medium at the first heat exchanger inlet 23p is equal to or lower than the dew point temperature of the dew condensation acid. It was decided to flow the heat medium without heating. That is, the first heat exchanger 23 is arranged at a position below the dew point temperature of the dew condensation acid. However, when the temperature of the heat medium at the inlet 23p of the first heat exchanger becomes equal to or lower than the dew point temperature of the dew condensation acid, the control device 2 heats the heat medium flowing into the first heat exchanger 23 to heat the heat medium. The one heat exchanger 23 may be arranged at a position higher than the dew point temperature of the dew condensation acid. Even in this case, the first heat exchanger 23 is arranged at a position below the dew point temperature of the dew condensation acid, although it is a short time when the thermal power generation facility is started, and therefore, corrosion is suppressed by the present invention. be able to.

Further, in the above-described embodiment and its modification, the steam turbine 30 is arranged between the generator 40 and the gas turbine 10. However, the arrangement of the generator 40, the gas turbine 10 and the steam turbine 30 is not particularly limited, and for example, the generator 40 may be arranged between the gas turbine 10 and the steam turbine 30.

Further, in the above-described embodiment and its modification, the generator 40 has a configuration coaxial with the gas turbine 10 and the steam turbine 30. However, any one of the generator 40, the gas turbine 10 and the steam turbine 30 may have a different rotation shaft. For example, the steam turbine 30 may be configured coaxially with another generator and have a rotation axis different from that of the generator 40 and the gas turbine 10, or may have other configurations.

Further, in the above-described embodiment and its modification, the boiler equipment is provided in the combined cycle power generation type thermal power generation equipment. However, the boiler equipment may be provided in a gas turbine power generation type thermal power generation equipment that does not have a steam turbine. Further, the boiler equipment may be configured to exchange heat with the exhaust gas of the steam turbine in the thermal power generation equipment. Alternatively, the boiler equipment can be applied not to thermal power generation equipment but to various equipment that exchanges heat with combustion exhaust gas, such as waste incineration equipment. In the waste incineration facility, since the combustion exhaust gas contains a large amount of components that generate dew condensation acid, the effect when the present invention is applied is high.

For example, the above boiler equipment can be applied to a high humidity air utilization turbine (AHAT) system. In a high-humidity air-utilizing turbine system, steam is generated by an exhaust heat recovery boiler (boiler equipment) and burned together with fuel gas by a gas turbine to generate power, and the water in the exhaust gas is recovered by a water recovery device to steam. It is a power generation system that supplies waste heat recovery boiler as water for generation. By applying the above boiler equipment to a high-humidity air utilization turbine system, the power generation efficiency is improved due to the improvement of exhaust heat recovery efficiency, and the water recovery device is made more compact and water is reduced as the inlet temperature of the water recovery device is lowered. It is possible to reduce the power of the cooling device of the recovery device, improve the water recovery efficiency, reduce the exhaust gas NOx, and the like.

In particular, by sending the drain generated in the boiler equipment (exhaust heat recovery boiler) to the water recovery device, the amount of water that can be recovered by the water recovery device can be increased, and the amount of steam supplied to the gas turbine can be increased. It is possible to improve the power generation output. Specifically, by setting the boiler equipment in the high-humidity air utilization turbine system to the boiler equipment having the configuration shown in the above-described embodiment and its modification, from the discharge port formed on the bottom surface of the boiler equipment. The discharged water can be collected and sent to a water recovery device. In this case, the water discharged from the discharge port can be sent to the water recovery device by various methods such as providing a drain tank for pumping up or directly sending water only by a pipe.

Further, the example of water recovery of the high humidity air utilization turbine system can be applied to the above-described embodiment and its modifications. In other words, in power generation equipment such as combined cycle plants, the wastewater discharged from the boiler equipment is not sent to the wastewater treatment equipment, but is passed through a demista installed near the flue outlet, for example, to remove the mist in the exhaust gas. The drain may be collected. As a result, water can be recovered in places where water is precious, such as inland areas and desert areas.

Further, the present invention can also be realized as a control device 2 provided in the boiler equipment and a control method performed by the control device 2. Further, the present invention can also be realized as an integrated circuit including a characteristic processing unit included in the control device 2. Further, the present invention is realized as a program that causes a computer (processor) to execute a characteristic process included in the control method, or a non-temporary recording medium that can be read by a computer (processor) in which the program is recorded. For example, as any medium such as flexible disk, hard disk, CD-ROM, MO, DVD, DVD-ROM, DVD-RAM, BD (Blue-ray (registered trademark) Disc), semiconductor memory, flash memory, magnetic storage device, optical disk, etc. It can also be realized. Then, such a program can be distributed via a recording medium such as a CD-ROM and a transmission medium such as the Internet.

Further, a form constructed by arbitrarily combining the components included in the above-described embodiment and the above-described modification is also included in the scope of the present invention.

The present invention can be applied to boiler equipment and the like capable of effectively utilizing heat in exhaust gas.

1 Thermal power generation equipment 2 Controller 10 Gas turbine 11 Air compressor 12 Combustor 13 Turbine 20, 20A, 20B Boiler equipment 21 First flow path formation equipment 22 Second flow path formation equipment 22a, 22e, 25a Outlet 22b, 22c 22f, 25b Inclined surface 22d Flat surface 23 First heat exchanger 23a First piping 23b Second piping 23p First heat exchanger inlet 24 Second heat exchanger 25 Flow path forming equipment 30 Steam turbine 31 Condenser 32 Water supply piping 33 Condensation pump 34, 35 Steam piping 40 Generator 50 Chimney 60 Wastewater treatment equipment 61, 62 Discharge piping

Claims (12)

A flow path forming facility that forms a flow path through which the exhaust gas discharged by burning fuel flows,
The first heat exchanger arranged in the flow path and
A second heat exchanger, which is arranged in the flow path and is arranged on the upstream side of the exhaust gas flow from the first heat exchanger, is provided.
The first heat exchanger is a boiler facility having an outer surface having a higher acid corrosion resistance to dew condensation acid, which is an acid generated when a component contained in the exhaust gas condenses, than the second heat exchanger. The first heat exchanger is
With the main body
The boiler equipment according to claim 1, further comprising a paint that is arranged on the surface of the main body and has higher acid corrosion resistance to the dew condensation acid than the main body. The boiler equipment according to claim 1 or 2, wherein the first heat exchanger is arranged at a position in the flow path that is equal to or lower than the dew point temperature of the dew condensation acid. The first heat exchanger is
The first pipe through which the heat medium flows and
It has a second pipe arranged on the upstream side of the exhaust gas flow from the first pipe and through which the heat medium flows.
The boiler equipment according to any one of claims 1 to 3, wherein the first pipe has an outer surface having a higher acid corrosion resistance to dew condensation acid than the second pipe. The boiler equipment according to any one of claims 1 to 4, wherein a discharge port for discharging the dew condensation acid is formed in the flow path forming equipment. further,
The boiler equipment according to claim 5, further comprising a pipe connecting the discharge port and the wastewater treatment equipment. The boiler equipment according to claim 5 or 6, wherein the flow path forming equipment has a bottom surface on which an inclined surface inclined toward the discharge port is formed. The boiler facility according to claim 7, wherein the inclined surface is arranged on the downstream side of the exhaust gas flow from the first heat exchanger. The boiler equipment according to claim 7 or 8, wherein the inclined surface has higher acid corrosion resistance to dew condensation acid than other parts of the flow path forming equipment. Further, a control device for controlling the flow of the heat medium in the first heat exchanger is provided.
The control device does not heat the heat medium in the first heat exchanger even when the temperature of the heat medium at the inlet of the first heat exchanger becomes equal to or lower than the dew point temperature of the dew condensation acid. Boiler equipment according to any one of claims 1 to 9. The flow path forming facility forms a flow path in the exhaust heat recovery boiler through which the exhaust gas discharged from the gas turbine flows.
The boiler equipment according to any one of claims 1 to 10, wherein the first heat exchanger is an economizer in the exhaust heat recovery boiler. A thermal power generation facility including the boiler facility according to any one of claims 1 to 11.

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