KR20240019302A - Operation method of ammonia fuel supply unit, power plant and boiler - Google Patents

Abstract

An ammonia fuel supply unit for supplying ammonia fuel to a boiler includes a first vaporizer and a second vaporizer. The first vaporizer is configured to vaporize liquid ammonia as a fuel using a heat source at a temperature equal to or higher than the boiling point of liquid ammonia. The second vaporizer is provided between the first vaporizer and the boiler, and uses hot air generated using the arrangement of the boiler as a direct or indirect heat source to vaporize the liquid ammonia remaining in the vaporization process in the first vaporizer. It is composed.

Description

Operation method of ammonia fuel supply unit, power plant and boiler

The present disclosure relates to a method of operating an ammonia fuel supply unit, power plant and boiler.

This application claims priority based on Patent Application No. 2021-120097 filed with the Japan Patent Office on July 21, 2021, and uses the content here.

Conventionally, power plants that supply ammonia fuel to boilers are known. For example, the power plant disclosed in Patent Document 1 is equipped with a vaporizer that vaporizes liquid ammonia to generate ammonia gas. Ammonia gas generated by the vaporizer is supplied to the boiler as fuel. The vaporizer uses hot water sent from the heat recovery boiler as a heat source. The hot water that has completed heat exchange with liquid ammonia returns to the heat recovery boiler via the circulation passage.

Japanese Patent No. 6245404 Publication

In the above patent document, hot water circulating between a heat recovery boiler and a vaporizer is used as a heat source for vaporizing liquid ammonia, so there is a risk of affecting the efficiency of the heat cycle constituted by the turbine and condenser of the power plant. Additionally, in the above patent document, vaporization treatment using hot water as an indirect heat source is performed only once, and there is a risk that the amount of heat for vaporization treatment of liquid ammonia cannot be secured.

The purpose of the present disclosure is to provide a method of operating an ammonia fuel supply unit, power plant, and boiler that secures the amount of heat required to vaporize liquid ammonia and suppresses the effect on the thermal efficiency of the heat cycle.

An ammonia fuel supply unit according to at least one embodiment of the present disclosure,

It is an ammonia fuel supply unit to supply ammonia fuel to the boiler,

a first vaporizer for vaporizing liquid ammonia as fuel using a heat source at a temperature equal to or higher than the boiling point of the liquid ammonia;

It is provided between the first vaporizer and the boiler, and uses hot air generated using the arrangement of the boiler as a direct or indirect heat source to vaporize the liquid ammonia remaining in the vaporization process in the first vaporizer. 2nd vaporizer for

is provided.

A power plant according to at least one embodiment of the present disclosure,

The ammonia fuel supply unit,

the boiler generating steam using combustion gas generated by combustion of fuel supplied from the ammonia fuel supply unit as a heat source;

a turbine for rotating using the steam from the boiler as a driving source;

Generator for generating power by rotation of the turbine

is provided.

A method of operating a boiler according to at least one embodiment of the present disclosure,

This is a method of operating a boiler supplied with ammonia fuel,

A first vaporization process for vaporizing liquid ammonia as a fuel using a heat source at a temperature equal to or higher than the boiling point of the liquid ammonia;

A second vaporization treatment process for vaporizing the liquid ammonia remaining in the first vaporization treatment process using hot air generated using an array of boilers as a direct or indirect heat source.

Equipped with

According to the present disclosure, it is possible to provide an ammonia fuel supply unit, a power plant, and a boiler operation method that secures the amount of heat for vaporizing liquid ammonia and suppresses the effect on the thermal efficiency of the heat cycle.

1 is a schematic diagram showing a boiler according to an embodiment of the present disclosure.
2 is a schematic diagram of a power plant according to an embodiment of the present disclosure.
Figure 3A is a schematic diagram showing an ammonia fuel supply unit according to one embodiment of the present disclosure.
3B is a schematic diagram showing an ammonia fuel supply unit according to one embodiment of the present disclosure.
Figure 4 is a flowchart showing a method of operating a boiler according to an embodiment of the present disclosure.

Hereinafter, preferred embodiments according to the present disclosure will be described with reference to the drawings. In addition, the present invention is not limited to this embodiment, and when there are multiple embodiments, it also includes a configuration by combining each embodiment. In the following description, up or upward refers to the upper side in the vertical direction, and downward or downward refers to the lower side in the vertical direction, and the vertical direction is not exact and includes errors.

In addition, the dimensions, materials, shapes, relative arrangements, etc. of component parts described as embodiments or shown in the drawings are not intended to limit the scope of the present disclosure, but are merely illustrative examples.

For example, expressions expressing relative or absolute arrangement such as “in a certain direction,” “along a certain direction,” “parallel,” “orthogonal,” “center,” “concentric,” or “coaxial,” are strictly such expressions. It not only indicates the arrangement, but also indicates the state of relative displacement with a tolerance or an angle or distance sufficient to obtain the same function.

For example, expressions indicating that things are in an equal state, such as “same,” “equal,” and “homogeneous,” not only express a state of being strictly equal, but also indicate that there is a tolerance, or difference to the extent that the same function can be obtained. It should also indicate the status.

For example, expressions representing shapes such as a square shape or a cylindrical shape not only represent shapes such as a square shape or a cylindrical shape in a geometrically strict sense, but also include uneven portions, chamfered portions, etc. to the extent that the same effect is obtained. The shape is also shown.

On the other hand, the expressions “to include,” “include,” or “to have” one component are not exclusive expressions that exclude the presence of other components.

In addition, similar configurations may be given the same reference numerals and explanation may be omitted.

<Overview of boiler (10) and power plant (1)>

1 is a schematic diagram showing a boiler according to an embodiment of the present disclosure.

The boiler 10 according to an embodiment of the present disclosure uses pulverized coal (carbon-containing solid fuel) as pulverized fuel, combusts this pulverized fuel by a burner, and uses the heat generated by this combustion as water supply or It is a coal-fired (pulverized coal-fired) boiler that can generate superheated steam by exchanging heat with steam. The boiler 10 of this embodiment burns, in addition to pulverized fuel, ammonia gas generated by vaporizing liquid ammonia using a burner. Therefore, in the boiler 10 of this embodiment, mixed combustion of pulverized coal and ammonia gas is performed.

In the following description, liquid ammonia and ammonia gas may be referred to generically or, if no distinction is made, may be referred to as ammonia fuel. In addition, liquid ammonia may be liquid ammonia as a pure substance, or may be a mixed solution in which liquid ammonia and water are mixed in a very small proportion.

In this embodiment, as shown in FIG. 1, the boiler 10 has a furnace 11, a combustion device 12, and a combustion gas passage 13. The furnace 11 has a rectangular hollow shape and is installed along the vertical direction. The furnace wall 101 constituting the furnace 11 is composed of a plurality of heat transfer tubes and pins connecting them, and heat generated by combustion of at least one of pulverized fuel or ammonia gas is combined with water or steam flowing inside the heat transfer tube. By heat exchange, the temperature rise of the furnace wall 101 is suppressed.

The combustion device 12 is provided on the lower side of the furnace wall 101 constituting the furnace 11. In this embodiment, the combustion device 12 has a plurality of burners (for example, 21, 22, 23, 24, 25) mounted on the furnace wall 101. For example, the burners 21, 22, 23, 24, and 25 are one set arranged at equal intervals along the circumferential direction of the furnace 11, and are arranged in multiple stages along the vertical direction (for example, in FIG. 1). 5 steps) are placed. However, the shape of the furnace, the number of burners in one stage, the number of stages, their arrangement, etc. are not limited to this embodiment.

An ammonia fuel supply unit 60 for supplying ammonia fuel to the boiler 10 is connected to the burners 21, 22, and 23 through an ammonia gas supply pipe 69. The ammonia fuel supply unit 60 is configured to vaporize liquid ammonia as fuel using seawater and hot air generated using the arrangement of the boiler 10. In this embodiment, ammonia gas generated by vaporization treatment is supplied to the burners 21, 22, and 23. Additionally, hot air may be a direct heat source for vaporizing liquid ammonia, or it may be an indirect heat source. Details of the ammonia fuel supply unit 60 will be described later.

The burners 24 and 25 are connected to a plurality of crushers (mills) 34 and 35 through pulverized coal supply pipes 29 and 33 (hereinafter, the crushers 34 and 35 are collectively referred to as the crusher 3). in some cases). In this grinder 3, for example, a grinding table (not shown) is supported in a housing so as to be rotatable, and a plurality of grinding rollers (not shown) above this grinding table can rotate in conjunction with the rotation of the grinding table. It is supported and constructed. When coal is put between a plurality of crushing rollers and a crushing table, it is pulverized, and is conveyed to a classifier (not shown) in the housing of the crusher 3 by a conveying gas (primary air, oxidizing gas), and is predetermined. Pulverized fuel classified within the particle size range can be supplied to the burners 24 and 25 from the pulverized coal supply pipes 29 and 33. In addition, the transport gas also plays a role in drying the pulverized fuel.

The above-described conveying gas is delivered to the pulverizer 3 through the air pipe 30 from the primary air ventilator 31 (PAF: Primary Air Fan) that introduces outside air. The air pipe 30 includes a hot air induction pipe 30A through which hot air heated by the air heater 42 flows in the air delivered from the primary air ventilator 31, and air in the air delivered from the primary air ventilator 31. It is provided with a cold air guide pipe 30B through which cold air close to room temperature flows without passing through the heater 42, and a conveying gas flow path 30C through which hot air and cold air merge and flow. A hot air damper 30D and a cold air damper 30E are provided in the hot air induction pipe 30A and the cold air induction pipe 30B, respectively. By adjusting the opening degrees of each of these dampers according to the supply conditions of the pulverized coal fuel, the flow rate and temperature of the conveying gas flowing through the conveying gas flow path 30C are adjusted. In addition, in this embodiment, the conveying gas flowing through the conveying gas flow path 30C includes hot air from the hot air guide pipe 30A. That is, the hot air induction pipe 30A and the conveying gas flow path 30C are configured to guide hot air heated by the air heater 42 to the pulverizer 3 that crushes coal as fuel. In the following description, when the hot air guide pipe 30A and the conveying gas flow path 30C are collectively referred to as the pulverizer heat air pipe 39, there may be cases.

The heat air pipe 39 for the pulverizer connected to the air heater 42 and the pulverizer 3 includes a branch portion 63 that is connected to the heat air pipe 62, which is a component of the ammonia fuel supply unit 60. . An adjustment damper 49 for the pulverizer is provided in the heat air pipe 39 for the pulverizer between the branch portion 63 and the pulverizer 3, and a heat source adjustment damper 68 is provided in the heat air pipe 62. The pulverizer adjustment damper 49 is configured to adjust the flow rate of the return gas (i.e., the flow rate of hot air) supplied to the pulverizer 3, and the heat source adjustment damper 68 is configured to adjust the flow rate of the return gas supplied to the pulverizer 3, and the heat source adjustment damper 68 is configured to adjust the flow rate of the return gas supplied to the pulverizer 3. It is configured to adjust the flow rate of hot air. Both the grinder adjustment damper 49 and the heat source adjustment damper 68 of this embodiment are dampers whose openings can be adjusted. Details will be described later, but the opening degrees of the pulverizer adjustment damper 49 and the heat source adjustment damper 68 are adjusted according to the combustion conditions of the boiler 10, such as the ammonia mixture combustion rate, so that there is no need to supply to the pulverizer 3. Excess hot air is supplied to the ammonia fuel supply unit 60. As a result, a heat source for the ammonia fuel supply unit 60 to vaporize liquid ammonia is secured. In addition, in the embodiment illustrated in FIG. 1, the hot air pipe 62 is connected to the conveying gas flow path 30C, but in other embodiments, the hot air pipe 62 may be connected to the hot air guide pipe 30A. , may be connected to the outlet of the air heater 42.

In addition, the furnace 11 is provided with an air duct 36 at the mounting position of the burners 21, 22, 23, 24, and 25, and one end of an air duct (wind duct) 37 is connected to the air duct 36. there is. The air duct 37 is provided with a forced draft fan (FDF) 38 at the other end.

As shown in FIG. 1, the combustion gas passage 13 is connected to the vertical upper part of the furnace 11. The combustion gas passage 13 is a heat exchanger for recovering the heat of the combustion gas, and is provided with superheaters 102, 103, 104, reheaters 105, 106, and economizers 107, and the furnace 11 Heat exchange is performed between the generated combustion gas and the water or steam circulating inside each heat exchanger.

As shown in FIG. 1, the combustion gas passage 13 is connected to its downstream side with a flue 14 through which heat-exchanged combustion gas is discharged. The flue 14 is provided with an air heater 42 for heating the air flowing through each of the air duct 37 and the air pipe 30. In the air heater 42, heat exchange is performed between the outside air flowing through the air duct 37 and the combustion gas flowing through the flue 14, and combustion air supplied to the burners 21, 22, 23, 24, and 25 The temperature can be raised. Additionally, in the air heater 42, heat exchange is performed between the outside air flowing toward the hot air guide pipe 30A and the combustion gas flowing through the flue 14, and the outside air can be changed into hot air. Accordingly, it is understood that the air heater 42 is configured to heat the outside air using the arrangement of the boiler 10.

Additionally, in the flue 14, a denitrification device 43 is provided at a position upstream of the air heater 42. The denitrification device 43 supplies a reducing agent that has the effect of reducing nitrogen oxides, such as ammonia and urea, into the flue 14, and causes a reaction between the nitrogen oxides in the combustion gas supplied with the reducing agent and the reducing agent. Nitrogen oxides in combustion gas are removed and reduced by promoting them through the catalytic action of a denitrification catalyst installed inside. The gas duct 41 connected to the flue 14 is located downstream of the air heater 42, and includes a dust collection device 44 such as an electrostatic precipitator, an induced draft fan (IDF) 45, and a desulfurization device. (46), etc. are provided, and a funnel (50) is provided at the downstream end.

On the other hand, when the plurality of pulverizers [34, 35(3)] are driven, the generated pulverized fuel flows to the burners 24, 25 through the pulverized coal supply pipes 29, 33 together with the return gas (primary air, oxidizing gas). is supplied to. In addition, by heat exchange between the exhaust gas discharged from the flue 14 and the air heater 42, heated combustion air (secondary air, oxidizing gas) flows from the air duct 37 through the upwind 36 to the burner 21. , 22, 23, 24, 25). The burners 24 and 25 blow a pulverized fuel mixture containing pulverized fuel and conveying gas into the furnace 11 and blow combustion air into the furnace 11, and at this time, the pulverized fuel mixture ignites, causing a flame. can be formed. A flame is generated in the lower part of the furnace 11, and high-temperature combustion gas rises within the furnace 11 and is discharged into the combustion gas passage 13. Simultaneously with the start of blowing of the pulverized fuel mixture (or after ignition of the pulverized fuel mixture), the burners 21, 22, and 23 blow ammonia gas into the furnace 11, thereby causing combustion of ammonia gas and mixing pulverized coal and ammonia. Combustion takes place. Additionally, as the oxidizing gas, air is used in this embodiment. It may have a higher or lower oxygen ratio than air, and can be used by optimizing the fuel flow rate.

After that, as shown in FIG. 1, the combustion gas is supplied to the second superheater 103, third superheater 104, and first superheater 102 (hereinafter simply referred to as superheaters) disposed in the combustion gas passage 13. After heat exchange in the second reheater 106, the first reheater 105 (hereinafter sometimes simply referred to as a reheater), and the economizer 107, the denitrification device 43 Nitrogen oxides are reduced and removed, particulate matter is removed in the dust collector 44, and sulfur oxides are removed in the desulfurization device 46, and then discharged into the atmosphere from the stack 50. Additionally, each heat exchanger does not necessarily have to be arranged in the order described above with respect to the combustion gas flow.

In addition, Figure 1 does not accurately show the position of each heat exchanger (superheaters 102, 103, 104, reheaters 105, 106, and economizer 107) in the combustion gas passage 13, and each heat exchanger The batch purity of the combustion gas flow is not limited to the description in FIG. 1.

Figure 2 is a schematic diagram of a power plant according to an embodiment of the present disclosure. As an example, the power plant 1 of this embodiment includes a boiler 10 including each of the heat exchangers described above, a turbine 110 for rotating using steam from the boiler 10 as a power source, and the turbine 110. A generator 115 for generating power by rotation, a condenser 114 for condensing the steam discharged from the turbine 110, and a boiler for sending the condensate treated by the condenser 114 to the boiler 10. It is provided with a water pump 123 and an ammonia fuel supply unit 60. The boiler 10, turbine 110, condenser 114, and boiler feed pump 123 form a defined thermal cycle (eg, Rankine cycle). By drawing from turbine 110 in this thermal cycle, generator 115 generates power. The circulating heat medium in this thermal cycle is water circulating at a pressure and temperature above the triple point.

In one embodiment, all of the above-described components of the power plant 1 except the ammonia fuel supply unit 60 are existing facilities, and the ammonia fuel supply unit 60 is additionally installed to these existing facilities.

The turbine 110 of this embodiment is composed of, for example, a high-pressure turbine 111, a medium-pressure turbine 112, and a low-pressure turbine 113, and is composed of, for example, a combustion gas flowing through the combustion gas passage 13 (see FIG. 1). The high pressure turbine 111 and the medium pressure turbine 112 are connected to each other through heat recovery reheaters 105 and 106. A condenser 114 is connected to the low pressure turbine 113. The condenser 114 accommodates a heat pipe 117 configured to allow cooling water to flow therein. Cooling water is, for example, sea water, fresh water, or brackish water. The steam that rotates the low-pressure turbine 113 flows into the condenser 114 and is cooled by the cooling water to become condensate.

The condenser 114 is connected to the economizer 107 through the water supply line L1. The feed water line L1 is provided with, for example, a condensate pump (CP) 121, a low-pressure feed water heater 122, a boiler feed water pump (BFP) 123, and a high-pressure feed water heater 124. A part of the steam that drives the turbines 111, 112, and 113 (110) is extracted from the low-pressure feedwater heater 122 and the high-pressure feedwater heater 124, and is extracted from the high-pressure feedwater heater 124 through an extraction line (not shown). and is supplied as a heat source to the low-pressure water heater 122, and the water supplied to the economizer 107 is heated.

The fuel used in the boiler 10 may be solid fuel such as biomass fuel, PC (petroleum coke) fuel generated during petroleum refining, or petroleum residue. In addition, the fuel is not limited to solid fuel, and petroleum such as heavy oil, diesel oil, and heavy oil, and liquid fuel such as factory waste fluid can also be used. Furthermore, gaseous fuel (natural gas, by-product gas, etc.) can be used as the fuel. Additionally, it can be applied to mixed combustion boilers that use a combination of these fuels.

<Example of details of ammonia fuel supply unit 60 according to one embodiment>

Figure 3A is a schematic diagram showing an ammonia fuel supply unit [60A (60)] according to one embodiment of the present disclosure. The ammonia fuel supply unit 60A is configured to vaporize liquid ammonia using the above-described hot air as a direct heat source. In addition, in FIG. 3A, the hot air damper 30D, cold air guide pipe 30B, and cold air damper 30E conceptually illustrated in FIG. 1 are omitted (the same applies to FIG. 3B).

The ammonia fuel supply unit 60A includes a first vaporizer 81 for vaporizing liquid ammonia as fuel using seawater, and a second vaporizer [82A ( 82)]. Seawater is an example of a heat source with a temperature above the boiling point of liquid ammonia. The heat source is outside the thermal cycle that includes the boiler 10 as a component. The ammonia fuel supply unit 60 of this embodiment further includes an ammonia tank 71 provided on the upstream side of the first vaporizer 81. Liquid ammonia stored in the ammonia tank 71 is supplied to the first vaporizer 81 by driving the ammonia supply pump 75. The supply pressure at this time is adjusted by the pressure adjustment valve 109.

The first vaporizer 81 of this embodiment includes a first container 91 that accommodates a plurality of first heat transfer tubes (not shown) extending up and down. Liquid ammonia flowing into the first vaporizer 81 flows inside the first heat transfer tube. Additionally, seawater is supplied to the first container 91 by a seawater pump outside the city. Seawater flowing into the first container 91 exchanges heat with liquid ammonia flowing inside the first heat transfer tube. Thereby, liquid ammonia is vaporized and ammonia gas is generated. However, although the temperature of seawater exceeds the boiling point of liquid ammonia, there are cases where it falls below the dew point temperature of liquid ammonia when moisture is mixed with liquid ammonia. Therefore, in the vaporization process in the first vaporizer 81, liquid ammonia is It remains. Ammonia fuel (ammonia gas and liquid ammonia) discharged from the first vaporizer 81 is supplied to the second vaporizer 82A via the connection pipe 89. Additionally, the liquid ammonia remaining in the first vaporizer 81 includes liquid ammonia that has not been vaporized in the process of flowing through the first heat transfer tube, and liquid ammonia that has been vaporized and then re-condensed in the process of flowing through the first heat transfer tube.

Additionally, the heat source of the first vaporizer 81 may be other than seawater as long as it has a temperature higher than the boiling point of liquid ammonia, and may be, for example, water (industrial water) or steam. These are also preferably heat sources outside the thermal cycle system that includes the boiler 10 as a component.

The second vaporizer 82A is configured to vaporize the liquid ammonia remaining in the vaporization process of the first vaporizer 81 using the hot air generated using the arrangement of the boiler 10 as a direct heat source. The second vaporizer 82A of this embodiment includes a second container 92 that accommodates a second heat transfer pipe (not shown) through which ammonia fuel flows. A heat air pipe 62A (62), which is a component of the ammonia fuel supply unit 60, is connected to the second vaporizer 82A. The hot air guided into the second vaporizer 82 by the hot air pipe 62A exchanges heat with the ammonia fuel flowing through the second heat transfer pipe. The temperature of the hot air is sufficiently higher than the evaporation temperature and dew point temperature of liquid ammonia. Therefore, among the ammonia fuel flowing into the second vaporizer 82A, the liquid ammonia remaining in the first vaporizer 81 is vaporized, and the remaining ammonia gas that was already vaporized at the time of flow is heated up. The ammonia gas discharged from the second vaporizer 82A of this embodiment is supplied to the boiler 10 via the ammonia gas supply pipe 69 in a state with a constant degree of superheat. Additionally, the second container 92 of the second vaporizer 82A may accommodate a fan (not shown) for promoting the flow of hot air. Thereby, heat exchange between hot air and ammonia fuel is promoted.

In another embodiment, the ammonia fuel supply unit 60A does not need to be equipped with the ammonia tank 71, the ammonia supply pump 75, and the pressure adjustment valve 109. For example, instead of the ammonia tank 71, liquid ammonia may be supplied to the first vaporizer 81 from a large tank lorry or ship storing liquid ammonia. Additionally, liquid ammonia, such as ammonia mist, may be mixed into the ammonia gas discharged from the second vaporizer 82.

According to the above configuration, a plurality of heat sources for vaporizing liquid ammonia, such as seawater (or other heat sources with a temperature above the boiling point of liquid ammonia) and hot air, are used, so the amount of heat for vaporizing liquid ammonia can be easily secured. In addition, seawater and hot air as heat sources are outside the system of the specified heat cycle constituted by the boiler 10, turbine 110, condenser 114, and boiler feed water pump 123, so their influence on the thermal efficiency of the heat cycle. This is suppressed. In view of the above, an ammonia fuel supply unit 60A is realized that secures the amount of heat for vaporizing liquid ammonia and suppresses the influence on the thermal efficiency of the heat cycle.

Additionally, the hot air pipe 62A is connected to the second vaporizer 82A, so that the second vaporizer 82A vaporizes liquid ammonia using hot air as a direct heat source. Since the heat contained in the hot air is directly transferred to the liquid ammonia in the second vaporizer 82A, the amount of heat for vaporizing the liquid ammonia can be more easily secured.

The ammonia tank 71 of this embodiment stores liquid ammonia mixed with liquid ammonia and water at a specified ratio. Water is mixed with liquid ammonia in a ratio of several mol%, for example. According to the above configuration, because the liquid ammonia contains water, stress corrosion cracking of steel materials constituting the ammonia tank 71 can be suppressed. Thereby, leakage of liquid ammonia from the ammonia tank 71 can be suppressed. In addition, the dew point temperature of liquid ammonia containing water tends to be higher than that of liquid ammonia as a pure substance, for example, but sufficient vaporization treatment by the first vaporizer 81 and the second vaporizer 82A 2 It is possible to suppress ammonia mist from being included in the ammonia fuel discharged from the vaporizer 82A. As a result, misfire in the boiler 10 during ammonia mixed combustion can be suppressed.

The ammonia fuel supply unit 60A is provided with a hot air pipe 62A that guides hot air from the air heater 42 to the second vaporizer 82A, and a heat source adjustment damper 68 provided in the hot air pipe 62A. . The heat source adjustment damper 68 is configured to adjust the flow rate of hot air flowing through the hot air pipe 62A (that is, in the embodiment illustrated in FIG. 3A, the second vaporizer 82A is a direct heat source). The amount of hot air is adjusted by adjusting the opening degree of the heat source adjustment damper 68. The opening degree of this heat source adjustment damper 68 may be changed according to the supply amount of ammonia fuel supplied to the second vaporizer 82A. As a result, the heat source required by the second vaporizer 82A in order to vaporize the ammonia fuel is secured. Additionally, the supply amount of ammonia fuel supplied to the second vaporizer 82A is correlated with the ammonia mixed combustion rate.

In another embodiment, in addition to the flow rate of the supplied ammonia fuel (or instead of the flow rate of the supplied ammonia fuel), the opening degree of the heat source adjustment damper 68 may be adjusted according to the pressure in the second vaporizer 82. . Depending on the pressure in the second vaporizer 82A, the evaporation temperature of the liquid ammonia, etc. is determined, and the amount of heat required for the vaporization process of the liquid ammonia is determined. The pressure in this second vaporizer 82A may be specified by a pressure gauge (not shown) provided at the inlet or outlet of the second vaporizer 82A, and the internal pressure of the ammonia tank 71 and the pressure adjustment valve 109 It may be specified by the degree of openness. In addition, the adjustment of the opening degree of the heat source adjustment damper 68 may be performed by a controller 90 described later or may be performed by an operator.

According to the above configuration, the opening degree of the heat source adjustment damper 68 is adjusted, so that the second vaporizer 82A can use hot air according to the flow rate of the supplied ammonia fuel as a heat source. In addition, since the hot air pipe 62A induces hot air from the air heater 42, even if the equipment including the boiler 10 and the air heater 42 is existing equipment, additional installation work is required for this existing equipment. By doing so, a configuration for the second vaporizer 82A to use hot air as a heat source can be realized.

Additionally, the second vaporizer 82A is configured to generate ammonia gas by heating the ammonia fuel discharged from the first vaporizer 81 to a dew point temperature or higher. As a specific example, the opening degrees of the pulverizer adjustment damper 49 provided in the pulverizer heat air pipe 39 and the heat source adjustment damper 68 provided in the heat air pipe 62A are adjusted, thereby adjusting the heat air pipe 62A. The flow rate of flowing hot air can be adjusted, and the heat source that can be used by the second vaporizer 82A can be adjusted. At this time, the opening degrees of the hot air damper 30D and the cold air damper 30E shown in FIG. 1 may be adjusted together to control the temperature of the hot air.

Additionally, the respective opening degrees of the pulverizer adjustment damper 49 and the heat source adjustment damper 68 may be adjusted according to the pressure in the second vaporizer 82A (the pressure specification method is as described above). In addition, the adjustment of the opening degrees of the pulverizer adjustment damper 49 and the heat source adjustment damper 68 may be performed by a controller 90 described later or may be performed by an operator.

According to the above configuration, mixing of ammonia mist into the ammonia gas discharged from the second vaporizer 82A can be suppressed. Therefore, misfire in the boiler 10 can be suppressed.

The ammonia fuel supply unit 60 is provided with a controller 90 configured to control the opening degree of the heat source adjustment damper 68 according to the flow rate of the ammonia fuel supplied to the second vaporizer 82A. The flow rate of ammonia fuel supplied to the second vaporizer 82 may be obtained based on the ammonia mixed combustion rate.

The controller 90 includes a processor that executes various computational processes and a memory that non-transitory or temporarily stores various data processed by the processor. The processor is realized by CPU, GPU, MPU, DSP, various computing devices other than these, or a combination thereof. Memory is realized by ROM, RAM, flash memory, or a combination thereof.

The controller 90 of this embodiment is configured to control not only the ammonia fuel supply unit 60 but also the power plant 1, and obtains a command indicating the ammonia mixed combustion rate in the boiler 10. Based on this ammonia mixed combustion rate, the controller 90 specifies the supply amount of ammonia fuel to the boiler 10. The supply amount of a specific ammonia fuel can be regarded as the flow rate of ammonia fuel to be supplied to the second vaporizer 82A. Based on the flow rate of this ammonia fuel, the controller 90 adjusts the opening degree of the heat source adjustment damper 68.

According to the above configuration, the flow rate of hot air used as a heat source by the second vaporizer 82A can be automatically adjusted according to the supply amount of ammonia fuel.

Additionally, when adjusting the opening degree of the heat source adjustment damper 68, the controller 90 may also adjust the opening degree of the grinder adjustment damper 49. In this case, the hot air generated by the air heater 42 can be appropriately and automatically distributed between the hot air supplied to the pulverizer 3 and the hot air directly used in the second vaporizer 82A according to the supply amount of ammonia fuel. there is.

In this embodiment, the heat air pipe 62A is provided by branching from the heat air pipe 39 for a pulverizer. According to the above configuration, even if the equipment including the boiler 10, the air heater 42, and the pulverizer 3 is already installed, the heat air pipe 62A is branched from the heat air pipe 39 for the pulverizer, so the existing equipment It is possible to facilitate the task of additionally installing the ammonia fuel supply unit (60B).

Although the details of the ammonia fuel supply unit 60A have been illustrated above, the number of the first vaporizer 81 and the second vaporizer 82A (82) may be either singular or plural (as illustrated in FIG. 3B). The same applies to the ammonia fuel supply unit 60B described later). As a specific example, a plurality of first vaporizers 81 may be arranged in series or parallel, and a plurality of second vaporizers 82A (82) may also be arranged in series or parallel. As a result, more liquid ammonia can be vaporized, and thus the amount of ammonia gas supplied to the boiler 10 can be increased.

<Example of ammonia fuel supply unit 60B according to another embodiment>

FIG. 3B is a configuration diagram showing an ammonia fuel supply unit [60B (60)] according to another embodiment of the present disclosure. The ammonia fuel supply unit 60B is configured to vaporize liquid ammonia using the above-described hot air as an indirect heat source. In the following, the same components as those of the ammonia fuel supply unit 60A are given the same reference numerals in the drawings, and some or all of their descriptions are omitted.

The ammonia fuel supply unit 60B is provided with a hot air pipe 62B(62), a heat exchanger 65, a pipe 66, and a second vaporizer 82B(82). The heat air pipe 62B is connected to the branch portion 63 and the heat exchanger 65, and the heat air pipe 62B guides hot air into the interior of the heat exchanger 65.

The hot air introduced into the heat exchanger 65 exchanges heat with the heat medium liquid circulating between the heat exchanger 65 and the second vaporizer 82, and the heat medium liquid is heated. The pipe 66 constitutes a part of the circulation path 77 for the heat medium liquid. The pipe 66 guides the heat medium liquid discharged from the heat exchanger 65 by driving the pump 55 provided in the circulation path 77 to the second vaporizer 82B. The second vaporizer [82B (82)] is configured to vaporize the liquid ammonia remaining in the vaporization process in the first vaporizer (81) using the heated heating medium liquid as a direct heat source. That is, the second vaporizer 82B is configured to vaporize liquid ammonia using the hot air generated using the arrangement of the boiler 10 as an indirect heat source. The second vaporizer 82B is, for example, a hot water bath type vaporizer, and the temperature of the hot water as a heat medium flowing into the second vaporizer 82B is higher than the evaporation temperature and dew point temperature of liquid ammonia. Ammonia gas discharged from the second vaporizer (82B) is supplied to the boiler (10) via the ammonia gas supply pipe (69).

According to the above configuration, the ammonia fuel supply unit 60B, like the ammonia fuel supply unit 60A, can secure the amount of heat for vaporizing liquid ammonia and suppress the influence of the heat cycle on the thermal efficiency.

Additionally, the heat medium liquid heated by hot air in the heat exchanger 65 flows into the second vaporizer 82B via the pipe 66. The second vaporizer 82B vaporizes liquid ammonia using heated heat medium liquid, that is, using hot air as an indirect heat source. Since the specific volume of the heat medium liquid is small compared to hot air, the second vaporizer 82 that accommodates the second heat transfer tube can be miniaturized. Therefore, the second vaporizer 82B can be miniaturized.

The heat source adjustment damper 68 provided in the hot air pipe 62B is configured to adjust the flow rate of hot air flowing through the hot air pipe 62B (i.e., an indirect heat source of the second vaporizer 82A in the embodiment illustrated in FIG. 3B). It is composed. In this embodiment, the controller 90 adjusts the opening degree of the heat source adjustment damper 68 according to the flow rate of the ammonia fuel supplied to the second vaporizer 82A (that is, according to the ammonia mixed combustion rate of the boiler 10). Adjust. At this time, the controller 90 according to the present embodiment also adjusts the opening degree of the heat source adjustment damper 68 provided in the heat air pipe 39 for the pulverizer. Since the advantages of adopting the above configuration are the same as described above with reference to FIG. 3A, detailed description will be omitted to avoid duplication of explanation.

<Example of operating method of boiler 10>

Figure 4 is a flowchart showing a boiler operation method according to an embodiment of the present disclosure. The flowchart shown in FIG. 4 is executed by the controller 90 as an example. In the flow chart of FIG. 4, both ammonia fuel supply units 60A and 60B (see FIGS. 3A and 3B) are applicable.

Initially, coal burning of the boiler 10 is carried out (S11). For example, the controller 90 is connected to the pulverizer 3, the hot air damper 30D, the cold air damper 30E, the pulverizer adjustment damper 49, the primary air ventilator 31, and the press-fit ventilator 38. Send a control signal. The burners 24 and 25 blow a pulverized fuel mixture of pulverized fuel and conveying gas into the furnace 11 and blow combustion air into the furnace 11. The pulverized fuel mixture is ignited, and a flame is formed within the boiler 10. Additionally, in this embodiment, at this time, the burners 21, 22, and 23 are not in operation, the heat source adjustment damper 68 is closed, and hot air is not supplied to the ammonia fuel supply unit 60.

Subsequently, it is determined whether to start ammonia mixed combustion (S13). For example, the controller 90 determines whether the mixed combustion start condition is met. The mixed combustion start condition is that the temperature in the furnace 11 becomes a certain temperature or higher, that a mixed combustion start command is input from the operator, or a combination thereof. In this embodiment, coal combustion is performed until the mixed combustion start conditions are met (S13: "No").

When the mixed combustion start condition is met (S13: “Yes”), the ammonia mixed combustion rate is obtained (S15). The mixed combustion rate may be a value indicated by a command previously written in the program, or may be a value input by the operator as a command.

Next, a first vaporization treatment process for vaporizing liquid ammonia using seawater is performed (S17). For example, the controller 90 specifies the flow rate of liquid ammonia to be supplied from the ammonia tank 71 based on the ammonia mixture combustion rate obtained in S13. The controller 90 controls the ammonia supply pump 75, the seawater pump, and the pressure adjustment valve 109 so that the specified liquid ammonia is vaporized in the first vaporizer 81. As seawater flows into the first vaporizer 81, liquid ammonia flows into the first vaporizer 81 from the ammonia tank 71, and heat exchange occurs between the liquid ammonia and the seawater. Thereby, the first vaporization treatment process is performed. Additionally, if seawater as a heat source in the first vaporization treatment process is sufficiently secured, the seawater pump may supply seawater at a constant flow rate to the first vaporizer 81 regardless of the ammonia mixture combustion rate obtained in S15.

Next, a second vaporization treatment process for vaporizing the liquid ammonia remaining in the first vaporization treatment process is performed using the hot air generated using the arrangement of the boiler 10 as a direct or indirect heat source (S19 ).

In the second vaporization treatment step (S19) of the present embodiment, the opening degree of the heat source adjustment damper 68 is determined according to the ammonia mixed combustion rate obtained in S15 (that is, according to the ammonia fuel supplied to the second vaporizer 82). is controlled by the controller 90. As a result, hot air according to the ammonia mixed combustion rate is used by the second vaporizer 82 as a heat source. As a result, the remaining liquid ammonia in the first vaporizer 81 is vaporized, and the temperature of the ammonia gas vaporized in the first vaporizer 81 increases. Ammonia gas discharged from the second vaporizer 82 is supplied to the burners 21, 22, and 23 via the ammonia gas supply pipe 69. When these burners blow ammonia gas into the furnace 11, combustion of ammonia gas occurs and mixed combustion of coal and ammonia begins.

According to the above configuration, the flow rate of the amount of hot air used as a heat source in the second vaporization treatment process can be adjusted according to the ammonia mixing combustion rate. Therefore, ammonia gas according to the ammonia mixed combustion rate can be supplied to the boiler 10.

Furthermore, in the second vaporization treatment step (S19) of this embodiment, the controller 90 controls the opening degree of the heat source adjustment damper 68 according to the ammonia mixed combustion rate obtained in S15. As the ammonia mixed combustion rate increases, the amount of coal supplied to the boiler 10 decreases, so the amount of hot air to be supplied to the pulverizer 3 decreases, and the opening degree of the heat source adjustment damper 68 can be reduced. As a result, at least a portion of the hot air generated by the air heater 42 becomes surplus. The controller 90 of this embodiment controls the opening degree of the heat source adjustment damper 68 so that this excess hot air flows through the hot air pipe 62. That is, the amount of hot air obtained by subtracting the amount of hot air to be supplied to the pulverizer 3 from the amount of hot air generated in the air heater 42 flows through the hot air pipe 62 and directly or indirectly acts as a heat source for the second vaporizer 82. It is used as The amount of surplus hot air determined according to such ammonia mixed combustion rate sufficiently exceeds the required minimum value of the amount of hot air to be used in the second vaporizer 82, which is determined based on the supply amount of ammonia fuel. That is, sufficient hot air required for the second vaporization treatment process is secured, and ammonia mist can be suppressed from being included in the ammonia gas discharged from the second vaporizer 82.

According to the above configuration, the hot air generated by the air heater 42 is appropriately and automatically mixed with the hot air supplied to the pulverizer 3 and the hot air used directly or indirectly in the second vaporizer 82 according to the ammonia mixing combustion rate. It can be distributed as

In another embodiment, the heat air pipe 62 and the heat air pipe 39 for a pulverizer may be separately connected to the air heater 42, and in this case, the opening degree of the heat source adjustment damper 68 is the heat air pipe for a pulverizer. It may be set regardless of the openness of (39).

After execution of S19, it is determined whether the ammonia mixture combustion rate is changed (S21). For example, the controller 90 determines whether the program to be executed includes an ammonia mixture combustion rate change command, or whether an ammonia mixture combustion rate change command has been input by the operator. If the ammonia mixture combustion rate is changed (S21: “Yes”), the controller 90 repeats S15 to S21.

If the ammonia mixture combustion rate is not changed (S21: "No"), it is determined whether the temperature of the ammonia gas supplied to the boiler 10 is below the specified value (S23). For example, the controller 90 acquires the temperature of the ammonia gas based on the detection result of the temperature sensor 88 (see FIGS. 3A and 3B) provided in the ammonia gas supply pipe 69, and the acquired temperature is the specified value. Determine whether it is below . The specified value is a value higher than the evaporation temperature and dew point temperature of liquid ammonia. If the temperature of the ammonia gas is above the specified value (S23: "No"), S27 described later is executed.

On the other hand, when the ammonia gas is below the specified value (S23: "Yes"), the heat source used in the second vaporizer 82 is insufficient in the future for some reason, and ammonia mist is discharged from the second vaporizer 82. There is a possibility that it will happen. In this case, notification processing is executed (S25). For example, the controller 90 notifies the operator that the temperature of the ammonia gas is below the specified value. The operator can determine whether to terminate the operation of the boiler 10.

Afterwards, it is determined whether to end operation of the boiler 10 (S27). For example, the controller 90 determines whether a command to end operation of the boiler 10 has been input from the operator. If no end command is input (S27: "No"), the controller 90 returns processing to S21. When a termination command is input (S27: "Yes"), the controller 90 terminates the operation of the boiler 10 after executing the prescribed processing.

Additionally, in S11 according to another embodiment, combustion of coal and oil, for example, may be performed instead of combustion of coal. Alternatively, mixed combustion of ammonia gas and other fuels may be performed from the start of operation of the boiler 10, and S11 and S13 do not need to be performed.

<Organization>

The contents described in some of the above-described embodiments are understood as follows, for example.

1) The ammonia fuel supply unit 60 according to at least one embodiment of the present disclosure,

An ammonia fuel supply unit 60 for supplying ammonia fuel to the boiler 10,

A first vaporizer (81) for vaporizing liquid ammonia as fuel using a heat source at a temperature equal to or higher than the boiling point of the liquid ammonia;

It is provided between the first vaporizer 81 and the boiler 10, and the hot air generated using the arrangement of the boiler 10 is used as a direct or indirect heat source to vaporize the first vaporizer 81. A second vaporizer (82) for vaporizing the liquid ammonia remaining in the treatment.

is provided.

When liquid ammonia is supplied as fuel for the boiler 10, the supply amount tends to be greater than when liquid ammonia is used as a reducing agent for, for example, removing or reducing nitrogen oxides discharged from the boiler 10. . Additionally, the ratio of the latent heat of evaporation to the calorific value of ammonia is about 6%, which is also high compared to fuels such as propane (the ratio of the latent heat of evaporation to the calorific value is about 0.8%). Therefore, the amount of heat required to vaporize liquid ammonia used as fuel tends to increase. In this regard, according to the configuration of 1) above, a heat source and hot air with a temperature above the boiling point of liquid ammonia are used as a plurality of heat sources to vaporize liquid ammonia, so the amount of heat for vaporizing liquid ammonia can be easily secured. . Additionally, since all of the above heat sources are outside the system of the heat cycle including the boiler 10 as a component, their influence on the thermal efficiency of the heat cycle is suppressed. In view of the above, an ammonia fuel supply unit 60 is realized that secures the amount of heat for vaporizing liquid ammonia and suppresses the influence on the thermal efficiency of the heat cycle.

2) In some embodiments, the ammonia fuel supply unit 60 described in 1) above,

a heat air pipe (62) for guiding the hot air from an air heater (42) that heats the outside air using the arrangement of the boiler (10);

A heat source adjustment damper 68 provided in the hot air pipe 62, for adjusting the flow rate of the hot air as the heat source of the second vaporizer 82.

It is further provided with

According to the configuration of 2) above, the opening degree of the heat source adjustment damper 68 is adjusted, so that hot air according to the flow rate of the supplied ammonia fuel can be used as a heat source. In addition, since the hot air pipe 62 induces hot air from the air heater 42, even if the equipment including the boiler 10 and the air heater 42 is existing equipment, additional installation work is required to install the existing equipment. By doing so, it is possible to realize a configuration in which the second vaporizer 82 uses hot air as a heat source.

3) In some embodiments, an ammonia fuel supply unit 60 as described in 2) above,

It further includes a controller 90 configured to control the opening degree of the heat source adjustment damper 68 according to the flow rate of ammonia fuel supplied to the second vaporizer 82.

According to the configuration of 3) above, the flow rate of hot air used as a heat source of the second vaporizer 82 can be automatically adjusted according to the supply amount of ammonia fuel.

4) In some embodiments, an ammonia fuel supply unit 60 as described in 2) or 3) above,

The hot air pipe 62 is provided by branching from the hot air pipe 35 for the pulverizer to guide the hot air heated by the air heater 42 to the pulverizer 3 that crushes coal as fuel.

According to the configuration of 4) above, even if the equipment including the boiler 10, the air heater 42, and the pulverizer 3 is an existing equipment, the heat air pipe 62 is branched from the heat air pipe 35 for the pulverizer. Therefore, it is possible to facilitate the additional installation of the ammonia fuel supply unit 60 in existing equipment.

5) In some embodiments, an ammonia fuel supply unit (60) as described in any of 2) to 4) above,

The hot air pipe 62 is connected to the second vaporizer 82,

The second vaporizer 82 is configured to vaporize the liquid ammonia using the hot air as a direct heat source.

According to the configuration of 5) above, since the heat contained in the hot air is directly transferred to the liquid ammonia, the amount of heat for vaporizing the liquid ammonia can easily be secured.

6) In some embodiments, an ammonia fuel supply unit (60) as described in any of 2) to 4) above,

A heat exchanger (65) configured to heat the heating medium liquid by heat exchange between the hot air induced by the hot air pipe (62) and the heating medium liquid,

A pipe 66 for guiding the heat medium liquid discharged from the heat exchanger 65 to the second vaporizer 82.

It is further provided with,

The second vaporizer 82 is configured to vaporize the liquid ammonia using the hot air as an indirect heat source.

According to the configuration of 6) above, the heat medium liquid heated by hot air in the heat exchanger 65 flows into the second vaporizer 82 via a pipe. The second vaporizer 82 vaporizes liquid ammonia using heated heat medium liquid. Since the specific volume of the heat medium liquid is small compared to hot air, the second vaporizer 82 can be miniaturized.

7) In some embodiments, an ammonia fuel supply unit (60) as described in any of 1) to 6) above,

An ammonia tank 71 is provided on the upstream side of the first vaporizer 81 and stores liquid ammonia mixed with liquid ammonia and water at a specified ratio.

According to the configuration of 7) above, since the liquid ammonia contains water, stress corrosion cracking in the ammonia tank 71 can be suppressed, and leakage of liquid ammonia from the ammonia tank 71 can be suppressed. In addition, the dew point temperature of liquid ammonia containing water tends to be higher than that of liquid ammonia as a pure substance, for example, but sufficient vaporization treatment by the first vaporizer 81 and the second vaporizer 82 2 It is possible to suppress ammonia mist from being included in the ammonia fuel discharged from the vaporizer 82.

8) In some embodiments, an ammonia fuel supply unit (60) as described in any of 1) to 7) above,

The second vaporizer 82 is configured to generate ammonia gas by heating the ammonia fuel discharged from the first vaporizer 81 to a dew point temperature or higher.

According to the configuration of 8), it is possible to suppress ammonia mist from being included in the ammonia fuel discharged from the second vaporizer 82.

9) The power plant 1 according to at least one embodiment of the present disclosure,

The ammonia fuel supply unit 60 according to any one of 1) to 8) above,

The boiler (10) generates steam using combustion gas generated by combustion of fuel supplied from the ammonia fuel supply unit (60) as a heat source;

A turbine 110 for rotating using the steam from the boiler 10 as a driving source,

Generator 115 for generating power by rotation of the turbine 110

is provided.

According to the configuration of 9) above, for the same reason as 1) above, a power plant is realized that secures the amount of heat for vaporizing liquid ammonia and suppresses the influence of the heat cycle on the thermal efficiency.

10) In some embodiments, the power plant (1) described in 9) above,

an air heater 42 that heats outdoor air using the arrangement of the boiler 10;

A crusher (3) configured to crush coal as fuel;

A pulverizer provided in a pulverizer hot air pipe 39 for guiding the hot air generated by the air heater 42 to the pulverizer 3, and for adjusting the flow rate of the hot air supplied to the pulverizer 3. Adjustable Dampers for(49)

It is further provided with,

The ammonia fuel supply unit 60,

It is provided in a hot air pipe (62) branching from the hot air pipe (39) for a pulverizer on an upstream side of the pulverizer adjustment damper (49), and adjusts the flow rate of the hot air as the heat source of the second vaporizer (82). It further includes a heat source adjustment damper (68) for

The power plant (1),

The adjustment damper 49 for the pulverizer so that the flow rate of the hot air in each of the hot air pipe 39 and the hot air pipe 62 for the pulverizer is adjusted based on the ammonia mixed combustion rate in the boiler 10. ) and a controller 90 configured to control each of the heat source adjustment dampers 68.

According to the configuration of 10), as the ammonia mixed combustion rate increases, the amount of coal supplied to the boiler 10 decreases, so the amount of heat air required by the pulverizer 3 is reduced, and the amount of heat air required by the pulverizer 3 is reduced. The degree of opening becomes smaller. As a result, excess heat air is generated. On the other hand, as the ammonia mixed combustion rate increases, the amount of heat required by the second vaporizer 82 increases, so the opening degree of the heat source adjustment damper 68 increases. As a result, the surplus hot air described above is effectively used as a heat source for the second vaporizer 82. Therefore, the hot air generated by the air heater 42 can be appropriately and automatically distributed to the hot air supplied to the pulverizer 3 and the hot air used in the second vaporizer 82 according to the ammonia mixed combustion rate.

11) A method of operating the boiler 10 according to at least one embodiment of the present disclosure,

This is a method of operating the boiler 10 supplied with ammonia fuel,

A first vaporization process (S17) for vaporizing liquid ammonia as a fuel using a heat source at a temperature equal to or higher than the boiling point of the liquid ammonia;

A second vaporization treatment process (S19) for vaporizing the liquid ammonia remaining in the first vaporization treatment process (S17) using the hot air generated using the arrangement of the boiler 10 as a direct or indirect heat source.

Equipped with

According to the configuration of 11) above, for the same reason as 1) above, a method of operating the boiler 10 that secures the amount of heat for vaporizing liquid ammonia and suppresses the effect on the thermal efficiency of the heat cycle is realized. do.

12) In some embodiments, a method of operating the boiler 10 described in 11) above,

In the second vaporization treatment process (S19),

A heat source adjustment damper ( The opening degree of 68) is controlled according to the ammonia mixed combustion rate in the boiler 10.

According to the configuration of 12), the flow rate of the amount of hot air used as a heat source in the second vaporization treatment process (S19) can be adjusted according to the ammonia mixed combustion rate. Therefore, ammonia fuel according to the ammonia mixed combustion rate can be supplied to the boiler 10.

13) In some embodiments, a method of operating the boiler 10 described in 12) above,

In the second vaporization treatment process (S19),

A heat air pipe (39) for a pulverizer including a branch portion (63) that is a connection portion with the hot air pipe (62), and is connected to a pulverizer (3) configured to pulverize coal as fuel and the air heater (42). In the hot air pipe 39, the opening degree of the pulverizer adjustment damper 49 provided between the branch portion 63 and the pulverizer 3 is controlled according to the ammonia mixed combustion rate.

According to the configuration of 13), as the ammonia mixed combustion rate increases, the amount of coal supplied to the boiler 10 decreases, so the amount of heat air required by the crusher 3 is reduced, and the amount of heat air required by the crusher 3 is reduced, and the amount of heat air required by the crusher 3 is reduced. The degree of opening becomes smaller. As a result, excess heat air is generated. On the other hand, as the ammonia mixed combustion rate increases, the amount of heat required by the second vaporizer 82 increases, so the opening degree of the heat source adjustment damper 68 increases. As a result, the above-described surplus of hot air is effectively used by the second vaporizer 82 as a heat source. Therefore, the hot air generated by the air heater 42 can be appropriately distributed between the hot air supplied to the pulverizer 3 and the hot air used in the second vaporizer 82 according to the ammonia mixed combustion rate.

1: Power plant
3: Grinder
10: Boiler
30: air pipe
34: Grinder
39: Heat air pipe for grinder
42: Air heater
49: Adjustable damper for grinder
60: Ammonia fuel supply unit
62: Heat pipe
63: bifurcation
65: heat exchanger
66: Plumbing
68: Heat source adjustment damper
71: Ammonia tank
81: first vaporizer
82: second vaporizer
90: controller
110: turbine
115: Generator

Claims (13)

It is an ammonia fuel supply unit to supply ammonia fuel to the boiler,
a first vaporizer for vaporizing liquid ammonia as fuel using a heat source at a temperature equal to or higher than the boiling point of the liquid ammonia;
It is provided between the first vaporizer and the boiler, and uses hot air generated using the arrangement of the boiler as a direct or indirect heat source to vaporize the liquid ammonia remaining in the vaporization process in the first vaporizer. 2nd vaporizer for
An ammonia fuel supply unit comprising: According to paragraph 1,
a heat air pipe for guiding the hot air from an air heater that heats the outside air using the arrangement of the boiler;
The ammonia fuel supply unit is provided in the hot air pipe and further includes a heat source adjustment damper for adjusting a flow rate of the hot air as the heat source of the second vaporizer. According to paragraph 2,
The ammonia fuel supply unit further includes a controller configured to control an opening degree of the heat source adjustment damper according to the flow rate of the ammonia fuel supplied to the second vaporizer. According to paragraph 2 or 3,
The ammonia fuel supply unit, wherein the hot air pipe is provided by branching from a hot air pipe for a pulverizer to guide the hot air heated by the air heater to a pulverizer that crushes coal as fuel. According to paragraph 2 or 3,
The hot air pipe is connected to the second vaporizer,
The ammonia fuel supply unit wherein the second vaporizer is configured to vaporize the liquid ammonia using the hot air as a direct heat source. According to paragraph 2 or 3,
a heat exchanger configured to heat the heat medium liquid by heat exchange between the heat air induced by the heat air pipe and the heat medium liquid;
Piping for guiding the heat medium liquid discharged from the heat exchanger to the second vaporizer
It is further provided with,
The ammonia fuel supply unit is configured to vaporize the liquid ammonia using the hot air as the indirect heat source. According to claim 1 or 2,
An ammonia fuel supply unit provided on an upstream side of the first vaporizer and further comprising an ammonia tank storing the liquid ammonia mixed with liquid ammonia and water at a specified ratio. According to claim 1 or 2,
The second vaporizer is configured to generate ammonia gas by heating the ammonia fuel discharged from the first vaporizer to a dew point temperature or higher. The ammonia fuel supply unit according to claim 1,
the boiler generating steam using combustion gas generated by combustion of fuel supplied from the ammonia fuel supply unit as a heat source;
a turbine for rotating using the steam from the boiler as a driving source;
Generator for generating power by rotation of the turbine
A power plant equipped with a. According to clause 9,
an air heater that heats outdoor air using the arrangement of the boiler;
a crusher configured to crush coal as fuel;
An adjustment damper for the pulverizer is provided in a hot air pipe for the pulverizer to guide the hot air generated by the air heater to the pulverizer, and adjusts the flow rate of the hot air supplied to the pulverizer.
It is further provided with,
The ammonia fuel supply unit,
It is provided in a hot air pipe branching from the hot air pipe for a pulverizer on an upstream side of the pulverizer adjustment damper, and further includes a heat source adjustment damper for adjusting the flow rate of the hot air as the heat source of the second vaporizer,
The power plant,
Configured to control each of the pulverizer adjustment damper and the heat source adjustment damper so that the flow rate of the hot air in each of the pulverizer hot air pipe and the hot air pipe is adjusted based on the ammonia mixed combustion rate in the boiler. A power generation plant further comprising a controller. This is a method of operating a boiler supplied with ammonia fuel,
A first vaporization process for vaporizing liquid ammonia as a fuel using a heat source at a temperature equal to or higher than the boiling point of the liquid ammonia;
A second vaporization treatment process for vaporizing the liquid ammonia remaining in the first vaporization treatment process using hot air generated using an array of boilers as a direct or indirect heat source.
A method of operating a boiler provided with. According to clause 11,
In the second vaporization treatment process,
The opening degree of the heat source adjustment damper provided in the heat air pipe for guiding the hot air from the air heater that heats the outside air using the arrangement of the boiler, and adjusting the flow rate of the hot air, is determined by the boiler. A boiler operation method controlled according to the ammonia mixture combustion rate. According to clause 12,
In the second vaporization treatment process,
A hot air pipe for a pulverizer including a branch portion that is a connection portion with the hot air pipe, the hot air pipe for a pulverizer being connected to a pulverizer configured to pulverize coal as fuel and the air heater, wherein the hot air pipe for a pulverizer is provided between the branch portion and the pulverizer. A boiler operating method in which the opening degree of the adjustment damper is controlled according to the ammonia mixture combustion rate.

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