KR20240017924A - Ammonia supply unit for power plant, ammonia vaporization treatment method for power plant, and power plant - Google Patents

Abstract

An ammonia supply unit for a power plant has at least one ammonia vaporizer. The ammonia vaporizer is provided inside the condenser for condensing the vapor discharged from the turbine. The ammonia vaporizer is configured to vaporize liquid ammonia using steam or condensate inside the condenser as a heat source.

Description

Ammonia supply unit for power plant, ammonia vaporization treatment method for power plant, and power plant

The present disclosure relates to an ammonia supply unit for a power plant, an ammonia vaporization treatment method for a power plant, and a power plant.

This application claims priority based on Patent Application No. 2021-114843 filed with the Japan Patent Office on July 12, 2021, and uses the contents herein.

Patent Document 1 discloses a power plant in which liquefied natural gas (hereinafter referred to as LNG) is used as fuel, and a condenser is connected to an LNG vaporizer through a refrigerant pipe. The heat of the steam flowing into the condenser from the turbine is recovered by cooling water flowing through the refrigerant pipe, and the heat-recovered cooling water flows into the LNG vaporizer and is used for the vaporization process of LNG.

Japanese Patent Publication No. 8-200017

In the above patent document, a configuration for vaporizing liquid ammonia is not disclosed, and a configuration for securing the amount of heat for vaporizing liquid ammonia is also not disclosed. Additionally, since heat exchange only occurs between the steam passing through the turbine and the cooling water flowing through the refrigerant pipe inside the condenser of the above patent document, there is a risk that the condensate treatment within the condenser may be insufficient. In this case, the pressure inside the condenser is not sufficiently lowered, and there is a risk that power generation efficiency may decrease.

The purpose of the present disclosure is to provide an ammonia supply unit for a power generation plant, an ammonia vaporization treatment method for a power plant, and a power plant that can secure the amount of heat for vaporizing liquid ammonia and improve the thermal efficiency of the heat cycle.

An ammonia supply unit for a power plant according to at least one embodiment of the present disclosure,

It is provided inside a condenser for condensing steam discharged from the turbine, and has at least one ammonia vaporizer for vaporizing liquid ammonia.

An ammonia vaporization treatment method for a power plant according to at least one embodiment of the present disclosure,

A vaporization treatment process of vaporizing liquid ammonia is provided using at least one ammonia vaporizer provided inside a condenser for processing vapor from a turbine.

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

boiler,

a turbine for rotating steam from the boiler as a power source;

A generator for generating power by rotation of the turbine,

A condenser for condensing steam discharged from the turbine;

At least one ammonia vaporizer provided inside the condenser and for vaporizing liquid ammonia

is provided.

According to the present disclosure, it is possible to provide an ammonia supply unit for a power generation plant, an ammonia vaporization treatment method for a power generation plant, and a power plant that can secure the amount of heat for vaporizing liquid ammonia and improve 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 3 is a schematic diagram showing an ammonia supply unit according to the first embodiment of the present disclosure.
4 is a graph conceptually showing the operation period of two vaporizers according to an embodiment of the present disclosure.
Figure 5 is a schematic diagram showing an ammonia supply unit according to a second embodiment of the present disclosure.
Figure 6 is a schematic diagram showing an ammonia supply unit according to a third embodiment of the present disclosure.
Figure 7 is a flowchart showing an ammonia vaporization treatment method for a power plant according to an embodiment of the present disclosure.
Figure 8 is a flowchart showing a vaporization treatment process 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 description thereof 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 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, the arrangement, etc. are not limited to this embodiment.

The burners 21, 22, and 23 are connected to the ammonia gas supply pipe 69. The ammonia gas supply pipe 69 is a component of the ammonia supply unit 60 (hereinafter sometimes simply referred to as the ammonia supply unit 60) for a power plant to generate ammonia gas by vaporizing liquid ammonia. Details of the ammonia 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 air pipe 30 is configured to guide hot air heated by the air heater 42 to the pulverizer 3 that crushes coal as fuel.

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 (air preheater) 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. Additionally, the ammonia gas supply pipe 69 described above may be connected to the denitrification device 43. That is, the ammonia gas supplied from the ammonia supply unit 60 may be used as a reducing agent. The ammonia supply unit 60 in this case is shown in FIG. 1 by a double-dashed line.

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 supply unit 60. Boiler 10, turbine 110, condenser 114 and boiler feed pump 123 form a defined thermal cycle (e.g. 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 supply unit 60 are existing facilities, and the ammonia supply unit 60 is installed additionally 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. Inside the condenser 114 of this embodiment, at least one ammonia vaporizer 61, which is a component of the ammonia supply unit 60, is provided. The ammonia vaporizer 61 is configured to vaporize liquid ammonia. The steam that rotates the low-pressure turbine 113 flows into the condenser 114 and is cooled by cooling water and liquid ammonia to become condensate. At this time, liquid ammonia is vaporized in the ammonia vaporizer 61 to generate ammonia gas.

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 feed water heater 122, and the feed water supplied to the economizer 107 is heated.

In the above-described embodiment, the boiler 10 is a coal-fired boiler in which mixed combustion with ammonia gas is performed, but it may be a coal-fired boiler. In this case, the ammonia supply unit 60 may be configured to supply ammonia gas as a reducing agent to the flue 14.

Additionally, 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. In addition, it can be applied to co-fired boilers that use a combination of these fuels.

In addition, the vaporized ammonia gas may be used as a fuel for other power generation means (gas turbine power generation, etc.) in addition to the fuel for the boiler 10. Additionally, ammonia gas vaporized in the condenser 114 installed in the gas turbine combined cycle plant may be used as fuel for the gas turbine.

<First example of details of ammonia supply unit 60>

Figure 3 is a schematic diagram showing an ammonia supply unit according to the first embodiment of the present disclosure. Before explaining the ammonia supply unit [60A (60)] according to the first embodiment, the condenser (114) will be described in detail. The condenser 114 includes a first container 81 that accommodates the heat transfer tube 117. The condenser 114 is disposed immediately below the turbine 110 (low pressure turbine 113).

The ammonia supply unit [60A (60)] according to the first embodiment includes an ammonia tank (71) storing liquid ammonia, at least one ammonia vaporizer (61) provided inside the condenser (114), and an ammonia tank (71). ) and a supply line 72 for supplying liquid ammonia from the ammonia vaporizer 61 to the ammonia vaporizer 61, and a supply pump 73 provided in the supply line 72. As an example, the ammonia vaporizer 61 is a heat transfer tube provided inside the first container 81 of the condenser 114, and the liquid ammonia supplied from the ammonia tank 71 when the supply pump 73 is driven is supplied through the heat transfer tube. It vaporizes during the flow process.

In this embodiment, the steam flowing into the first container 81 of the condenser 114 from the turbine 110 (low pressure turbine 113) exchanges heat with the cooling water flowing through the heat transfer pipe 117 described above. In addition, heat exchange occurs between the liquid ammonia flowing through the ammonia vaporizer (61). As a result, the vapor in the condenser 114 is treated as condensation water to generate condensate, and the liquid ammonia in the ammonia vaporizer 61 is vaporized to generate ammonia gas. Ammonia gas is discharged from the ammonia vaporizer 61 and supplied, for example, to the boiler 10.

Additionally, the heat transfer tube 117 or the ammonia vaporizer 61 may be immersed in condensed water accumulating at the bottom of the condenser 114 (not shown). For example, when the ammonia vaporizer 61 is immersed in condensate, liquid ammonia exchanges heat with the condensate. In this case as well, the ammonia vaporizer 61 can vaporize liquid ammonia using condensate as a heat source, and the condenser 114 can process condensate vapor by cooling the condensate. Additionally, the ammonia vaporizer 61 immersed in condensate may be arranged downstream of the heat transfer pipe 117 in the direction in which the steam flows. Additionally, only one of the plurality of ammonia vaporizers (61) may be disposed on the downstream side with respect to the heat transfer tube (117). Additionally, the ammonia supply unit 60 does not need to be equipped with an ammonia tank 71 and a supply pump 73. For example, liquid ammonia may be supplied to the ammonia vaporizer 61 by a large tank lorry or ship storing liquid ammonia.

According to the above configuration, the ammonia vaporizer 61 vaporizes liquid ammonia using at least one of the vapor or condensate inside the condenser 114 as a direct heat source. Therefore, a heat source for vaporizing liquid ammonia can be secured. At the same time, since liquid ammonia in addition to the cooling water is used for condensate treatment, condensate treatment in the condenser 114 is promoted. As a result, the internal pressure of the condenser 114 is sufficiently lowered, and the thermal efficiency of a thermal cycle including the turbine 110, the condenser 114, and the boiler 10, such as the Rankine cycle, is improved. Accordingly, an ammonia supply unit 60 is realized that can secure the amount of heat for vaporizing liquid ammonia and improve the thermal efficiency of the heat cycle.

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, when liquid ammonia is vaporized using steam extracted from the turbine 110 as a heat source, power generation efficiency is likely to decrease. However, in this embodiment, the heat generated in the condenser 114 is used to vaporize the liquid ammonia and the pressure drop in the condenser 114 is promoted, thereby increasing the turbine efficiency of the turbine 110. This increase can suppress the decline in power generation efficiency.

In the embodiment illustrated in Figure 3, the ammonia vaporizer 61 includes two or more vaporizers 61A arranged in parallel. In the illustrated embodiment, two vaporizers 61A are provided as heat transfer tubes. Liquid ammonia supplied from the ammonia tank 71 is vaporized while flowing through a certain vaporizer 61A. The two vaporizers 61A may be operated (vaporization process) at different timings or may be operated simultaneously. According to the above configuration, ammonia gas of the same temperature is discharged from each of two or more vaporizers 61A provided in parallel. Therefore, the amount of ammonia gas produced per unit time when the specified temperature is reached increases.

In this embodiment, the operating states of the two vaporizers 61A are switched with each other. More specifically, the ammonia supply unit 60A is provided with a switching valve 76 for switching the operating state of each vaporizer 61A. The switching valve 76 in this example is an opening/closing valve provided in each of the two liquid ammonia supply pipes 74, and the number of switching valves 76 is two. Liquid ammonia from the supply line 72 flows into the liquid ammonia supply pipe 74 with the switching valve 76 opened and is supplied to the vaporizer 61A. As a result, the vaporizer 61A operates and performs vaporization processing. In another embodiment, the switching valve 76 may be a three-way valve (flow switching valve) provided at the connection between the two liquid ammonia supply pipes 74 and the supply line 72. In this case, the number of switching valves 76 is one.

FIG. 4 is a graph conceptually showing the operation period of two vaporizers according to an embodiment of the present disclosure. In this embodiment, the two vaporizers 61A are configured to alternately perform vaporization processing in accordance with the operation of the switching valve 76. In the embodiment illustrated in FIG. 4, the end time of one vaporization process and the start time of the other vaporization process are the same, but in another embodiment, a specified time is left blank after one vaporization process is finished and the other vaporization process is completed. You may start the vaporization process of the indigo.

In another embodiment, the other vaporization process may be started before one vaporization process is completed. This is because, when switching, the two vaporizers are operated overlapping for a certain period of time, which allows for a stable supply of a certain amount of ammonia gas due to less variation in flow rate during switching.

Since the temperature of liquid ammonia is very low, there is a risk that vapor or condensate may adhere to the operating vaporizer 61A as precipitates such as frost or ice. As a more specific example, precipitates adhere to the outer surface of the heat transfer tube constituting the vaporizer 61A. Additionally, attachment of such precipitates may occur even when the vaporizer 61A is immersed in condensate.

If the vaporizer 61A continues the vaporization process as is, there is a risk that precipitates will further accumulate, heat transfer to the liquid ammonia may be impaired, and there is a risk that the liquid ammonia will remain in the ammonia gas discharged from the vaporizer 61A. In this regard, according to the above configuration, a time period occurs in which one vaporizer 61A is vaporized and the other vaporizer 61A is idle. In the other vaporizer 61A, the attached precipitates are removed by steam or condensed water inside the condenser 114. Therefore, the ammonia supply unit 60A can continuously and stably perform the vaporization process of liquid ammonia.

In this way, rather than simultaneously operating two or more vaporizers 61A provided in parallel, selectively switching the operating state of each vaporizer 61A produces ammonia gas that has reached a specified temperature continuously and stably. can do.

Returning to Fig. 3, the ammonia supply unit 60A of the first embodiment includes a temperature sensor 78 for detecting the temperature of the ammonia gas on the outlet side of the vaporizer 61A. In the illustrated embodiment, a temperature sensor 78 is provided in each of the two ammonia gas outlet pipes 77. The two ammonia gas outlet pipes 77 are respectively connected to the outlets of the two vaporizers 61A. In this embodiment, the ammonia gas flowing through the two ammonia gas outlet pipes 77 is supplied to the boiler 10 via the ammonia gas supply pipe 69 described above.

The ammonia supply unit 60A is provided with a controller 90 configured to control the switching valve 76 based on the measurement results of the two temperature sensors 78. However, in Fig. 3, in order to make the drawing easier to see, the controller 90 is electrically connected to only one temperature sensor 78 and one switching valve 76.

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. Additionally, the controller 90 may be configured to control the power plant 1.

To prevent excessive precipitates from being deposited in the ammonia vaporizer 61, the controller 90 is configured to adjust the operation period of the ammonia vaporizer 61 through control of the switching valve 76. The principle is as follows. As precipitates are deposited in the ammonia vaporizer 61, the amount of heat used in the vaporization process of liquid ammonia decreases, so the outlet temperature of ammonia gas tends to decrease. Therefore, in response to the outlet temperature of the ammonia gas discharged from the ammonia vaporizer 61 in operation meeting a specified drop condition (detailed below), the vaporization process in the ammonia vaporizer 61 in operation is paused, and the other The vaporization process in the ammonia vaporizer 61 on the side starts. As a result, it is possible to automatically switch the ammonia vaporizer 61 that performs the vaporization process to suppress liquid ammonia from being discharged from the ammonia vaporizer 61.

Based on the above principle, when the controller 90 of the present embodiment determines that the outlet temperature measured by one of the temperature sensors 78 satisfies the specified drop condition, it responds to one of the temperature sensors 78. The two switching valves 76 are controlled so that the open switching valve 76 on one side is closed and the other closed switching valve 76 is opened. This control is realized by sending a control signal from the controller 90 to each switching valve 76.

Additionally, the drop condition is that the temperature characteristic value specified based on the outlet temperature measured by the temperature sensor 78 falls below the specified threshold. The temperature characteristic value of this embodiment is the same as the outlet temperature measured by the temperature sensor 78. The temperature characteristic value in another embodiment is specified by the temperature sensor 78 measuring the temperature multiple times. As a more specific example, the temperature characteristic value is the temperature average value of the outlet temperature of ammonia gas, the temperature predicted value, or the temperature change rate. Additionally, when the outlet temperature of ammonia gas continues to decrease, the temperature change rate becomes a negative value.

Additionally, in another embodiment, a single temperature sensor 78 may be provided in the ammonia gas supply pipe 69. Even in this case, if the operating periods of the two vaporizers 61A do not overlap, it is possible to detect the outlet temperature of the ammonia gas discharged from the operating vaporizer 61A based on the detection result of the temperature sensor 78. do. Accordingly, the controller 90 can control the switching valve 76 based on the detection result of the single temperature sensor 78.

According to the above configuration, the opening and closing operation of the switching valve 76 can be automatically performed depending on the outlet temperature of the ammonia gas. Therefore, excessive deposition of precipitates in the ammonia vaporizer 61 can be automatically suppressed.

The ammonia supply unit 60A illustrated in FIG. 3 is configured to supply ammonia gas generated by vaporization treatment to the boiler 10. More specifically, the ammonia supply unit 60A is provided with an ammonia gas supply pipe 69 for supplying ammonia gas vaporized by the ammonia vaporizer 61 to the boiler 10. According to the above configuration, liquid ammonia can be converted into ammonia gas and supplied as fuel to the boiler 10. Therefore, the heat source in the condenser 114 can be effectively utilized, and ammonia gas as fuel can be supplied to the boiler 10.

In the embodiment illustrated in FIG. 3 , the first container 81 of the ammonia supply unit 60A accommodates the ammonia vaporizer 61 and the heat pipe 117. The ammonia vaporizer 61 is located upstream of the heat transfer pipe 117 in the direction in which steam flows. According to the above configuration, in the condenser 114, heat exchange between vapor and liquid ammonia is performed before heat exchange between vapor and cooling water. Since heat is transferred to the liquid ammonia from the vapor before being cooled by the cooling water, the amount of heat for vaporizing the liquid ammonia can be secured.

<Second example of details of ammonia supply unit 60>

Figure 5 is a schematic diagram showing an ammonia supply unit according to a second embodiment of the present disclosure. The ammonia supply unit [60B (60)] according to the second embodiment includes a second container (82) accommodating at least one ammonia vaporizer (61), and a first container (81) and a second container of the condenser (114). It is provided with a communication pipe (85) communicating with (82). Steam from the turbine 110 (low-pressure turbine 113) flows into the second container 82 via the communication pipe 85. The introduced vapor is condensed by heat exchange with liquid ammonia flowing through the ammonia vaporizer (61). Accordingly, the second vessel 82 is responsible for the function of condensing steam from the turbine 110 and is therefore understood to form part of the condenser 114. Condensed water generated in the second container 82 flows to the first container 81 via the drain pipe 83, which is a component of the ammonia supply unit 60B.

Additionally, in the illustrated embodiment, the communication pipe 85 is connected to the first container 81 and the second container 82, but instead of this, the steam between the turbine 110 and the first container 81 It may be connected to the flow path 89 and the second container 82. Also in this case, if the downstream end of the vapor flow path 89 is connected to the first container 81, the first container 81 and the second container 82 are provided in parallel with each other. In the example of FIG. 5, the ammonia vaporizer 61 includes two vaporizers 61A provided inside the second container 82, but these two vaporizers 61A may be connected in parallel with each other. Additionally, another ammonia vaporizer 61 may be provided inside the first container 81. That is, the number of ammonia vaporizers 61 may be two or more.

According to the above configuration, even if the first container 81 is an existing equipment, the ammonia supply unit 60B is completed by additionally installing the second container 82, the drain pipe 83, and the communication pipe 85. Therefore, construction of the ammonia supply unit 60B can be facilitated.

In the embodiment illustrated in FIG. 5 , the bottom portion 82A of the second container 82 is provided at a higher position than the bottom portion 81A of the first container 81. According to the above configuration, condensed water generated in the second container 82 easily flows into the first container 81 via the drain pipe 83. Therefore, steam or condensate circulates without stagnation.

<Third example of details of ammonia supply unit 60>

Figure 6 is a schematic diagram showing an ammonia supply unit according to a third embodiment of the present disclosure. The ammonia supply unit 60C (60) according to the third embodiment is different from the ammonia supply unit 60B in that the first container 81 and the second container 82 are provided in series. To explain the specific difference in configuration, the connection point of the vapor flow path 89 is the second container 82 instead of the first container 81, and the ammonia supply unit [60C (60)] is connected to the communication pipe 85 (FIG. 5 (see) Instead, a communication pipe 86 is provided. The steam flow path 89 forms a flow path downstream of the turbine 110 (low pressure turbine 113) and is connected to the turbine 110 and the second vessel 82. The communication pipe 86 is connected to the second container 82 and the first container 81. Accordingly, the steam discharged from the turbine 110 flows into the second container 82 via the steam flow path 89. Condensate generated in the second container 82 flows into the first container 81 through the drain pipe 83, and the vapor remaining in the condensate treatment of the second container 82 flows into the first container 81 through the communication pipe 86. 1 Container 81 processes the remaining vapor as condensation.

According to the above configuration, even if the first vessel 81 is an existing equipment, if the connection point of the steam flow path 89 is changed and the second vessel 82, the drain pipe 83, and the communication pipe 86 are additionally installed, The ammonia supply unit 60C is complete. Since additional construction on the existing first container, such as drilling work, is reduced, construction of the ammonia supply unit 60C can be facilitated.

<Example of ammonia vaporization treatment method for power plant>

Figure 7 is a flowchart showing an ammonia vaporization treatment method for a power plant according to an embodiment of the present disclosure. Figure 8 is a flowchart showing a vaporization treatment process according to an embodiment of the present disclosure. The flowcharts shown in FIGS. 7 and 8 are executed by the controller 90 as an example. Additionally, the ammonia gas generated by the ammonia vaporization treatment method described below may be used as either a fuel or a reducing agent. In the following description, the step may be abbreviated as "S".

As shown in FIG. 7, when the ammonia vaporization treatment method for a power plant is started, the vaporization treatment process is executed (S11). In the vaporization process, liquid ammonia is vaporized by at least one ammonia vaporizer 61. As a more specific example, in the vaporization treatment process of this example, the respective operating states of two or more vaporizers 61A connected in parallel are switched. The operating state of each vaporizer 61A is switched by the controller 90 controlling the switching valve 76 based on the detection result of the temperature sensor 78. Below, an embodiment in which the number of ammonia vaporizers 61 is two and two switching valves 76 are provided in two liquid ammonia supply pipes 74, respectively, will be described.

As shown in FIG. 8, in the vaporization treatment process, vaporization treatment is first performed using one ammonia vaporizer 61 (S31). The controller 90 transmits a control signal to change one of the two switch valves 76, which are both closed, to an open state. As a result, liquid ammonia flows into one ammonia vaporizer 61, and vaporization of the liquid ammonia is performed. Liquid ammonia generated during the vaporization process is used as fuel for the boiler 10, for example.

Subsequently, it is determined whether the temperature characteristic value specified based on the measurement result of the temperature sensor 78 corresponding to the ammonia vaporizer 61 performing the vaporization process satisfies the drop condition (S33). If the controller 90 determines that the drop condition is not met (S33: “No”), it is determined whether to end the vaporization treatment process (S35). For example, the controller 90 makes the determination based on whether or not it has received an end instruction signal for the vaporization process sent from the operator. If the controller 90 determines that the vaporization treatment process has not ended (S35: "No"), the process returns to S33. If excessive precipitates are not deposited in the operating ammonia vaporizer 61, the drop condition is not met (S33: "No") and a signal indicating the end of the vaporization treatment process is not received (S35: "No"), the controller (90) repeats S33 and S35.

Then, when a certain amount of precipitates attaches to the operating ammonia vaporizer 61 and the drop condition is met (S33: “Yes”), the controller 90 switches the ammonia vaporizer 61 performing the vaporization process (S37) . The controller 90 sends a control signal to each of the two switching valves 76 so that the open switching valve 76 is closed and the closed switching valve 76 is opened. After that, the process returns to S33. In this way, as the controller 90 repeats S31 to S37, the two ammonia vaporizers 61 automatically perform vaporization processing in turns.

When it is determined that the vaporization process is finished (S35: "Yes"), the controller 90 stops the ammonia vaporizer 61 that is performing the vaporization process (S39). Specifically, the controller 90 sends a control signal to the open switching valve 76 so that the switching valve 76 is closed. After completion of the vaporization treatment process, the treatment returns to the flow illustrated in Figure 7, and the method of vaporization treatment of ammonia is terminated.

<Organization>

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

1) The ammonia supply unit 60 for a power plant according to at least one embodiment of the present disclosure,

It is provided inside the condenser 114 for treating steam discharged from the turbine 110, and includes at least one ammonia vaporizer 61 for vaporizing liquid ammonia.

According to the configuration of 1) above, the ammonia vaporizer 61 vaporizes liquid ammonia using at least one of the vapor or condensate inside the condenser 114 as a direct heat source. Therefore, a heat source for vaporizing liquid ammonia can be secured. At the same time, since liquid ammonia in addition to the cooling water is used for condensate treatment, condensate treatment in the condenser 114 is promoted. As a result, the pressure inside the condenser 114 is sufficiently lowered, and the thermal efficiency of the heat cycle including the turbine 110 and the condenser 114 is improved. Accordingly, the ammonia supply unit 60 for a power generation plant is realized, which can secure the amount of heat for vaporizing liquid ammonia and improve the thermal efficiency of the heat cycle.

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

The condenser 114 is,

A heat pipe 117 configured to allow coolant to flow inside,

It includes a first container (81) accommodating the heat transfer tube (117),

A second container 82 is provided in communication with the first container 81 to form a part of the condenser 114 and accommodates the at least one ammonia vaporizer 61.

According to the configuration of 2) above, even if the condenser 114 including the heat transfer pipe 117 and the first container 81 is an existing facility, construction of additionally installing the ammonia supply unit 60 can be facilitated.

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

The bottom 82A of the second container 82 is provided at a higher position than the bottom 81A of the first container 81.

According to the configuration of 3) above, condensed water generated in the second container (82) easily flows into the first container (81). Therefore, steam or condensate circulates without stagnation.

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

The condenser 114 is,

A heat pipe 117 configured to allow coolant to flow inside,

A first container (81) accommodating the heat transfer tube (117)

Including,

The at least one ammonia vaporizer (61) is disposed on the upstream side of the heat transfer tube (117) in the first container (81).

According to the configuration in 4) above, in the condenser 114, the vapor exchanges heat with liquid ammonia before exchanging heat with the cooling water. Thereby, the amount of heat for vaporizing liquid ammonia can be secured.

5) In some embodiments, an ammonia supply unit (60) as described in any of 1) to 4) above,

The at least one ammonia vaporizer 61 includes two or more vaporizers 61A arranged in parallel.

According to the configuration of 5) above, ammonia gas of the same temperature is discharged from each of two or more vaporizers 61A provided in parallel. Therefore, it is possible to increase the amount of ammonia gas produced per unit time that has reached the specified temperature.

6) In some embodiments, the ammonia supply unit 60 described in 5) above,

It is further provided with a switching valve 76 for switching the operating state of each vaporizer 61A.

Precipitates such as frost or ice that adhere to the ammonia vaporizer 61 during the vaporization process of liquid ammonia may inhibit heat transfer to the liquid ammonia. In this regard, according to the configuration of 6), excessive deposition of precipitates in any of the vaporizers 61A can be suppressed by switching the switching valve 76.

7) In some embodiments, the ammonia supply unit 60 described in 6) above,

a temperature sensor 78 for detecting the temperature of the ammonia gas on the outlet side of each vaporizer 61A;

It further includes a controller 90 for controlling the switching valve 76 based on the detection result of the temperature sensor 78.

According to the configuration in 7), the controller 90 controls the switching valve 76 according to the outlet temperature of the ammonia gas, thereby automatically suppressing excessive deposition of precipitates in the vaporizer 61A.

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

It is further provided with an ammonia gas supply pipe 69 for supplying the ammonia gas vaporized by the ammonia vaporizer 61 to the boiler 10.

According to the configuration of 8) above, liquid ammonia can be converted into ammonia gas and supplied as fuel to the boiler 10. Therefore, the heat source in the condenser 114 can be effectively utilized, and ammonia gas as fuel can be supplied to the boiler 10.

9) An ammonia vaporization treatment method for a power plant according to at least one embodiment of the present disclosure,

A vaporization treatment process (S11) is provided in which liquid ammonia is vaporized by at least one ammonia vaporizer 61 provided inside the condenser 114 for processing vapor from the turbine 110.

According to the configuration of 9) above, for the same reason as 1) above, an ammonia vaporization treatment method for a power plant is realized that can secure the amount of heat for vaporizing liquid ammonia and improve the thermal efficiency of the heat cycle. .

10) In some embodiments, the ammonia vaporization treatment method for a power plant according to 9) above,

The at least one ammonia vaporizer (61) includes two or more vaporizers (61A) connected in parallel to each other,

In the vaporization treatment step (S11), the operating state of each vaporizer 61A is switched.

According to the configuration of 10), excessive deposition of precipitates in any of the vaporizers 61A can be suppressed.

11) In some embodiments, the ammonia vaporization treatment method for a power plant according to 10) above,

In the vaporization process S11, the operating state of each vaporizer 61A is determined based on the detection result of the temperature sensor 78 for detecting the temperature of the ammonia gas on the outlet side of each vaporizer 61A. Controls the switching valve 76 to switch.

According to the configuration of 11) above, the operating state of the vaporizer 61A can be stably switched by controlling the switching valve 76 based on the temperature of the ammonia gas.

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

Boiler (10),

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

A generator 115 for generating power by rotation of the turbine 110,

A condenser 114 for condensing the steam discharged from the turbine 110,

At least one ammonia vaporizer 61 provided inside the condenser 114 and for vaporizing liquid ammonia.

is provided.

According to the configuration of 12) above, for the same reason as 1) above, the power plant 1 is realized that can secure the amount of heat for vaporizing liquid ammonia and improve the thermal efficiency of the heat cycle.

1: Power plant
10: Boiler
60: Ammonia supply unit
61: Ammonia vaporizer
61A: Carburetor
69: Ammonia gas supply pipe
76: Diverter valve
78: Temperature sensor
81: first container
81A: bottom
82: Second container
82A: bottom
83: drain pipe
85, 86: Flue tube
89: Steam Euro
90: controller
110: turbine
111: turbine
114: revenge machine
115: Generator
117: Heat pipe

Claims (12)

An ammonia supply unit for a power plant, which is provided inside a condenser for condensing steam discharged from a turbine and includes at least one ammonia vaporizer for vaporizing liquid ammonia. According to paragraph 1,
The condenser,
A heat pipe configured to allow coolant to flow inside,
A first container accommodating the heat transfer tube
Including,
An ammonia supply unit for a power plant, comprising a second vessel provided in communication with the first vessel to form part of the condenser and containing the at least one ammonia vaporizer. According to paragraph 2,
An ammonia supply unit for a power plant, wherein the bottom of the second container is provided at a higher position than the bottom of the first container. According to paragraph 1,
The condenser,
A heat pipe configured to allow coolant to flow inside,
A first container accommodating the heat transfer tube
Including,
The ammonia supply unit for a power plant, wherein the at least one ammonia vaporizer is disposed on an upstream side of the heat transfer pipe in the first container. According to any one of claims 1 to 4,
The ammonia supply unit for a power plant, wherein the at least one ammonia vaporizer includes two or more vaporizers arranged in parallel. According to clause 5,
An ammonia supply unit for a power plant, further comprising a switching valve for switching the operating state of each of the vaporizers. According to clause 6,
a temperature sensor for detecting the temperature of ammonia gas on the outlet side of each vaporizer;
An ammonia supply unit for a power plant, further comprising a controller for controlling the switching valve based on the detection result of the temperature sensor. According to any one of claims 1 to 3,
An ammonia supply unit for a power plant, further comprising an ammonia gas supply pipe for supplying ammonia gas vaporized by the ammonia vaporizer to a boiler. An ammonia vaporization treatment method for a power plant, comprising a vaporization process of vaporizing liquid ammonia using at least one ammonia vaporizer provided inside a condenser for condensing vapor from a turbine. According to clause 9,
The at least one ammonia vaporizer includes two or more vaporizers connected in parallel with each other,
An ammonia vaporization treatment method for a power plant, wherein in the vaporization treatment step, the operating state of each of the vaporizers is switched. According to clause 10,
In the vaporization treatment process, a switching valve for switching the operating state of each vaporizer is controlled based on the detection result of a temperature sensor for detecting the temperature of the ammonia gas on the outlet side of each vaporizer. Ammonia vaporization treatment method. boiler,
A turbine for rotating using steam from the boiler as a power source,
A generator for generating power by rotation of the turbine,
a condenser for condensing the steam discharged from the turbine;
At least one ammonia vaporizer provided inside the condenser and for vaporizing liquid ammonia
A power plant equipped with a.

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