JP7403330B2 - Power generation plants and surplus energy thermal storage methods in power generation plants - Google Patents

Description

The present invention relates to a steam power generation plant that utilizes the combustion heat of various fuels, and in particular stores a portion of the heat of steam and a portion of surplus electricity as thermal energy (thermal storage), and stores (thermal storage) as necessary. Related to technology for supplying thermal energy to power plants.

There are thermal power plants that effectively utilize thermal energy to improve power plant performance from startup to shutdown, or to supply necessary thermal energy regardless of the operating state of the power plant. For example, Patent Document 1 describes "a boiler for generating steam, a steam turbine, a condenser, a feed water pump, a steam control valve, a turbine bypass piping, a turbine bypass valve, and a turbine bypass temperature reduction". A thermal power generation plant is disclosed that includes a heat storage device installed in a turbine bypass pipe, a supplementary water tank, piping connecting the supplementary water tank and the heat storage device, and an auxiliary boiler.

Japanese Patent Application Publication No. 8-319805

According to the technology disclosed in Patent Document 1, surplus thermal energy, which is thermal energy that was wasted when starting and stopping a power generation plant, can be stored in a heat storage material and used as a heat source during startup. Further, a heat storage device including heat storage materials having different melting points is provided, and surplus thermal energy is stored by passing steam in order from the one with the highest melting point. Therefore, surplus thermal energy can be recovered separately into high-temperature thermal energy and low-temperature thermal energy, and the heat can be used effectively.

However, during startup and the like, the temperature of the steam output from the boiler gradually increases. Therefore, the method of storing surplus thermal energy by always passing steam through a heat storage device having a heat storage material with a high melting point is not necessarily appropriate, and does not necessarily store thermal energy efficiently.

Furthermore, for example, when a power generation device using renewable energy such as solar light or wind power is incorporated into a power grid, it is necessary to adjust the output of the power generation plant in order to maintain stability of the power grid. However, in order to be able to respond to rapid load changes, it is desirable for power plants to maintain a minimum load. However, when a power generation plant maintains a minimum load, surplus power may be generated, and currently this surplus power cannot be fully utilized.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a technology for efficiently storing and utilizing surplus energy generated in a power generation plant.

The power generation plant of the present invention includes a boiler that heats supplied water to generate superheated steam, a steam turbine that is rotationally driven by the superheated steam superheated in the boiler and drives a generator, and surplus energy passing through the boiler. The present invention is characterized by comprising: a heat storage device that recovers and stores heat; and a control device that controls the surplus energy generated during operation, including when starting and stopping, to be stored in the heat storage device.

Further, the power generation plant of the present invention includes a boiler that heats supplied water to generate superheated steam, a steam turbine that is rotationally driven by the superheated steam superheated in the boiler and drives a generator, and a steam turbine that stores surplus energy. a heat storage device, the boiler includes a first boiler heat exchange section that generates a fluid having a temperature in a first temperature range by heat exchange, and the heat storage device stores thermal energy in the first temperature range. A part of the fluid generated in the first heat storage part that stores heat and the first boiler heat exchange part is guided to the first heat storage part, and after recovering the thermal energy in the first heat storage part, the first boiler A first heat recovery pipe leading to the outlet side of the heat exchange section.

According to the present invention, surplus energy generated in a power generation plant can be efficiently stored and utilized. Problems, configurations, and effects other than those described above will be made clear by the following description of the embodiments.

(a) is an explanatory diagram for explaining the relationship among the turbine generator load, boiler heat output, and steam temperature in each time change when the power plant is started and (b) is when the power plant is stopped. . FIG. 2 is an explanatory diagram for explaining the relationship among the turbine generator load, boiler heat output, and steam temperature in changes over time during pumping operation of the power plant. (a) is a system block diagram of a power generation plant of a first embodiment, and (b) is a block diagram of a control device of a first embodiment. It is an explanatory view for explaining the composition of the heat storage device of a first embodiment. It is an explanatory view for explaining control of the opening and closing state of each on-off valve by a control device at the time of starting up and stopping the power plant of the first embodiment. It is an explanatory view for explaining control of the opening and closing state of each on-off valve by a control device at the time of pumping operation of a power generation plant of a first embodiment. (a) is an explanatory diagram for explaining the opening/closing state of the on-off valve of the power plant of the first embodiment when it is in the first startup operation mode and (b) is in the second startup operation mode, respectively. (a) is an explanatory diagram for explaining the opening and closing states of the on-off valve of the power plant of the first embodiment in the third startup operation mode and (b) in the first stop operation mode, respectively. . It is an explanatory view for explaining the opening and closing state of the on-off valve of the power plant of the first embodiment at the time of pumping operation mode. (a) is a first startup operation mode, and (b) is a second startup operation mode, respectively, is an explanatory diagram for explaining the opening and closing states of each on-off valve of the heat storage device of the first embodiment. . (a) is an explanatory diagram for explaining the opening and closing states of each on-off valve of the heat storage device of the first embodiment in the first stop operation mode and (b) in the pumping operation mode, respectively. It is an explanatory view for explaining the opening and closing state of each on-off valve of the heat storage device of the first embodiment in the emergency operation mode. (a) is a system configuration diagram of a power generation plant of a second embodiment, and (b) is an explanatory diagram for explaining the configuration of a heat storage device of the second embodiment. It is an explanatory view for explaining control of the opening and closing state of each on-off valve by a control device at the time of starting up and stopping of a power generation plant of a second embodiment. It is an explanatory view for explaining control of the opening and closing state of each on-off valve by a control device at the time of pumping operation of a power generation plant of a second embodiment. (a) is a first start-up operation mode, and (b) is an explanatory diagram for explaining the opening and closing states of each on-off valve of the heat storage device of the second embodiment, respectively, during a second start-up operation mode. . (a) is an explanatory view for explaining the opening and closing states of each on-off valve of the heat storage device of the second embodiment in the first stop operation mode and (b) in the pumping operation mode, respectively. It is an explanatory view for explaining the opening and closing state of each on-off valve of the heat storage device of a second embodiment at the time of emergency operation mode. (a) is an explanatory diagram for explaining the configuration of a heat storage device according to a modification of the present invention, and (b) and (c) are diagrams showing the control of each on-off valve by the control device according to modification 1 of the present invention. It is an explanatory diagram for explanation. It is an explanatory view for explaining an example of the relationship between turbine generator load, boiler heat output, and steam temperature in time change at the time of startup of a power plant according to a modification of the present invention. (a) and (b) are explanatory diagrams for explaining the configuration of a heat storage device according to a modification of the present invention. (a) and (b) are explanatory diagrams for explaining the configuration of a heat storage device according to a modification of the present invention. FIG. 7 is an explanatory diagram for explaining an example of the relationship among the turbine generator load, boiler heat output, and steam temperature over time when the power generation plant according to a modification of the present invention is stopped. (a) describes the design temperature of each heat exchanger of the boiler of the power generation plant of the third embodiment, and (b) describes an example of the connection during heat recovery from the heat storage device of the third embodiment. FIG. (a) and (b) are explanatory diagrams for respectively explaining opportunities for recovering thermal energy stored in a heat storage device according to the third embodiment. It is an explanatory view for explaining another example at the time of recovery of thermal energy stored in the heat storage device of the third embodiment. It is an explanatory view for explaining another connection example at the time of heat recovery from a heat storage device of a modification of a third embodiment. It is an explanatory diagram for explaining connection to a heat storage device including a system configuration diagram of a power generation plant of a fourth embodiment. (a) is an explanatory diagram for explaining the example of composition of a heat storage device of a fourth embodiment, and (b) is a modification thereof. (a) to (c) are explanatory diagrams for explaining ON/OFF control of the electric heater according to the fourth embodiment. (a) is an explanatory view for explaining a connection example at the time of heat recovery of the fourth embodiment, and (b) is a modification thereof. It is an explanatory view for explaining an example of composition of a heat storage device of a modification of a fourth embodiment. It is a system configuration diagram of a power generation plant of a fifth embodiment. It is an explanatory view for explaining an example of composition of a heat storage device of a fifth embodiment. It is an explanatory view for explaining a connection example at the time of heat recovery of a fifth embodiment. It is an explanatory view for explaining the example of composition of the heat storage device of the modification of the fifth embodiment. It is an explanatory view for explaining a connection example at the time of heat recovery of a modification of the fifth embodiment. It is an explanatory view for explaining connection to a heat storage device including a system configuration diagram of a power generation plant of a modification of the fifth embodiment.

Embodiments of the present invention will be described below with reference to the drawings.

Prior to detailed description of each embodiment, an outline of the first to third embodiments of the present invention will be explained. In these embodiments, in order to effectively utilize surplus thermal energy in a power generation plant, heat is stored in a heat storage layer according to the temperature range of the surplus thermal energy. The stored heat is then recovered and utilized from the optimal temperature range at the appropriate timing during power plant operation. Note that the specific temperatures and the like described in this specification are merely examples for explanation.

Generally, a power generation plant includes a boiler that generates steam using heat obtained by burning fuel, and a steam turbine that generates electricity by rotating a turbine using the steam generated by the boiler. The surplus thermal energy in the embodiment is generated due to the difference between the amount of heat generated by the steam generated by the boiler (referred to as boiler heat output or boiler load) and the amount of heat required by the steam turbine (referred to as turbine generator load). do.

For example, when starting up a power plant, as shown in FIG. 1(a), after the boiler is ignited and before the boiler starts once-through operation, all of the boiler output heat is not used by the steam turbine. This is to warm up the equipment that makes up the steam cycle and to stabilize the process from startup to cruising operation of each equipment. During this time, surplus thermal energy is generated.

Furthermore, when the power generation plant is stopped, as shown in FIG. 1(b), a difference similarly occurs between the boiler heat output and the steam turbine generator load, and surplus thermal energy is generated. This means that even when the power plant is stopped, the boiler load must be maintained at about 20% for a predetermined period, while the turbine generator load monotonically decreases. Therefore, surplus thermal energy is generated during this time.

Further, as shown in FIG. 2, the power plant may be operated with the turbine generator load being smaller than the minimum load of the boiler by a predetermined amount α. Such an operating state occurs, for example, when the system absorbs fluctuations in the amount of power generated by natural energy. Hereinafter, in this specification, such an operating state of the power plant will be referred to as pumped storage operation. Even during this pumping operation, as shown in this figure, surplus thermal energy is generated due to the difference between the boiler heat output and the steam turbine generator load.

In the first to third embodiments of the present invention described below, surplus thermal energy output in the form of steam from a boiler and unused by the steam turbine is stored in a heat storage layer corresponding to the steam temperature at the time of generation. Also, when used, it is collected and used from the optimum temperature range. This allows surplus thermal energy to be efficiently stored and utilized.

<<First embodiment>>
A first embodiment of the present invention will be described. First, an example of a power generation plant to which the heat storage device of this embodiment is applied will be described. The heat storage device 200 of this embodiment is used, for example, in the power generation plant 100 shown in FIG. 3(a). FIG. 3(a) is a fluid system diagram of the power generation plant 100 of this embodiment.

The power generation plant 100 of this embodiment includes a boiler 110 that burns fuel and generates steam (superheated steam) using the heat of the combustion, and a generator 109 that rotates a turbine using the steam generated by the boiler 110. A steam turbine 120 that is driven to generate electricity; a water supply line 130 that returns exhaust steam from the steam turbine 120 to water and supplies it to the boiler 110; It includes a heat storage device 200 that stores heat and a control device 150 (see FIG. 3(b)).

The boiler 110 includes an economizer (ECO) 111, a water cooling wall 112, a brackish water separator 113, a superheater 114, and a reheater 115. In this embodiment, the superheater 114 and the reheater 115 are provided in multiple stages from downstream to upstream. Note that there may be one superheater 114 and one reheater 115.

The steam turbine 120 includes a high pressure steam turbine (HPT) 121, an intermediate pressure steam turbine (IPT) 122, and a low pressure steam turbine (LPT) 123, each of which performs a predetermined work for rotationally driving the generator 109. Equipped with Note that the intermediate pressure steam turbine 122 and the low pressure steam turbine 123 are also collectively referred to as an intermediate and low pressure steam turbine.

On the water supply line 130, a condenser 131, a condensate pump 132, a low pressure water heater (low pressure heater) 133, a deaerator 134, a water supply pump 135, and a high pressure water heater (high pressure heater) 136 are installed. and is provided.

In the power plant 100 having the above configuration, the economizer 111 preheats the supplied water by heat exchange with combustion gas. The water preheated by the economizer 111 passes through a furnace wall tube (not shown) formed in the wall of the furnace water wall 112 to generate a water-steam two-phase fluid. The water-steam two-phase fluid generated in the furnace water-cooled wall 112 is sent to a brackish water separator 113 and separated into saturated steam and saturated water. Here, saturated steam is guided to superheater 114, and saturated water is guided to condenser 131 through saturated water pipe 161, respectively.

The saturated steam separated by the brackish water separator 113 is superheated by a superheater 114 through heat exchange with combustion gas, and the generated superheated steam is introduced into the high-pressure steam turbine 121 via the main steam pipe 162. Note that the superheater 114 is provided in multiple stages as described above. Part of the steam from before the final stage superheater 114 is guided to the condenser 131 through the boiler bleed pipe 165. Note that the boiler bleed pipe 165 is provided with a boiler start bleed adjustment valve (heater bypass valve; EC) 175.

Steam that has performed predetermined work in the high-pressure steam turbine 121 is guided to the reheater 115 via the low-temperature reheat steam pipe 163. In the reheater 115, the steam that has performed a predetermined work in the high-pressure steam turbine 121 is resuperheated. The steam superheated in the reheater 115 is supplied to the intermediate pressure steam turbine 122 and the low pressure steam turbine 123 via the high temperature reheat steam pipe 164, where they each perform work and drive the generator 109. The main steam pipe 162 is provided with a main steam on-off valve 172 . Further, the high temperature reheat steam pipe 164 is provided with a reheat steam on-off valve 174 .

Steam that has completed its work in the low pressure steam turbine 123 is introduced into the condenser 131 through the turbine exhaust pipe 166. The condensate condensed in the condenser 131 passes through the low-pressure heater 133 by the condensate pump 132 together with the saturated water sent from the brackish water separator 113, and then is sent to the deaerator 134, where gas components in the condensate are removed. be done. The condensate that has passed through the deaerator 134 is further boosted in pressure by a water supply pump 135, then is sent to a high-pressure heater 136 to be heated, and is finally returned to the boiler 110.

Furthermore, the power plant 100 includes a main steam bypass pipe 167 that branches off from the main steam pipe 162 and guides the steam to the condenser 131, bypassing the high pressure steam turbine 121. The main steam bypass pipe 167 is provided with a main steam bypass on-off valve 177 .

The heat storage device 200 of this embodiment is arranged on the saturated water pipe 161, the boiler bleed pipe 165, and the main steam bypass pipe 167. The heat storage device 200 stores thermal energy of steam or saturated water flowing in the saturated water pipe 161, the boiler bleed pipe 165, and the main steam bypass pipe 167 by heat exchange. Steam or saturated water after heat exchange in the heat storage device 200 is introduced into the condenser 131 through respective piping.

Further, temperature sensors 181, 185, and 187 (see FIG. 3(b)) for detecting the temperature of steam passing through the saturated water pipe 161, the boiler bleed pipe 165, and the main steam bypass pipe 167 are each appropriately provided.

As shown in FIG. 3(b), the control device 150 receives instructions from the outside (such as a control console 151 placed in the power plant) or the temperature sensors 181, 185, and the like installed in the power plant 100. According to signals from various sensors including 187, the opening and closing of each on-off valve in the power generation plant 100 is controlled. For example, the main steam on-off valve 172, the reheat steam on-off valve 174, the boiler startup bleed air adjustment valve 175, and the main steam bypass on-off valve 177 of this embodiment are opened and closed depending on the operation mode. Details of the timing of opening and closing each on-off valve will be described later. Note that the on-off valves whose opening and closing are controlled by the control device 150 also include on-off valves included in the heat storage device 200, which will be described later.

The control device 150 includes, for example, a CPU, a memory, and a storage device, and achieves the above control by having the CPU load a program stored in the storage device in advance into the memory and execute it.

[Heat storage device]
Next, the heat storage device 200 of this embodiment will be explained using FIG. 4. Hereinafter, in this specification, steam, water, etc. that circulate within the power generation plant 100 will be referred to as fluids unless there is a need to distinguish between them.

The heat storage device 200 of this embodiment stores surplus thermal energy of the fluid in the power generation plant 100 according to instructions from the control device 150. The heat storage device 200 of the present embodiment includes a plurality of heat storage layers made of heat storage materials each having temperature characteristics (melting points) in different temperature ranges, a heat exchange section provided in each heat storage layer, and a heat storage device 200. A flow path that connects and guides the fluid in the piping to the heat exchange section or bypasses the heat storage device 200 and leads the fluid in the piping to the condenser 131, and regulates the inflow of fluid to each flow path. Equipped with an on-off valve (valve).

In this embodiment, when storing heat in the heat storage device 200, the path through which the fluid passes is changed depending on the temperature of the fluid flowing into the heat storage device 200. This allows for efficient heat storage. The route change is realized by a command from the control device 150 to an on-off valve (valve) provided in each flow path, which will be described later.

Hereinafter, in this embodiment, the heat storage device 200 includes a high temperature heat storage layer 210 (hereinafter also simply referred to as the high temperature layer 210), a medium temperature heat storage layer 220 (medium temperature layer 220), and a low temperature heat storage layer 230 (low temperature layer 220) as heat storage layers. A case in which three heat storage layers are provided will be described as an example.

Note that the high temperature layer 210 is a heat storage layer made of a heat storage material having temperature characteristics (melting point) in a temperature range (first temperature range) centered around 500°C. The intermediate temperature layer 220 is a heat storage layer made of a heat storage material having temperature characteristics in a temperature range centered around 400° C. (second temperature range). Furthermore, the low temperature layer 230 is a heat storage layer made of a heat storage material having temperature characteristics in a temperature range centered around 300° C. (third temperature range).

In addition, the heat storage device 200 of the present embodiment includes, as a heat exchange section, a high temperature heat exchange section 211 disposed within a high temperature layer 210 and a first medium temperature heat exchange section 211 disposed within a medium temperature layer 220, as shown in FIG. It includes an exchange section 221 and a second medium-temperature heat exchange section 222, and a first low-temperature heat exchange section 231, a second low-temperature heat exchange section 232, and a third low-temperature heat exchange section 233 arranged in the low-temperature layer 230.

Each heat exchange section (high temperature heat exchange section 211, first medium temperature heat exchange section 221, second medium temperature heat exchange section 222, first low temperature heat exchange section 231, second low temperature heat exchange section 232, third The low-temperature heat exchange section 233) exchanges heat with the inflowing fluid. When a fluid having a temperature equal to or higher than the melting point of the disposed heat storage layer flows into each of them, the heat storage layer functions as a heat storage section that stores thermal energy in the heat storage layer. On the other hand, when a fluid having a temperature lower than the melting point of the arranged heat storage layer flows in, the thermal energy stored in the heat storage layer is radiated.

The heat storage device 200 includes a main steam first flow path 371, a main steam bypass flow path 372, a main steam third flow path 373, a boiler exhaust flow path 351, and a boiler exhaust bypass flow as flow paths used during heat storage. It includes a passage 352, a saturated water passage 311, and a saturated water bypass passage 312.

Main steam first flow path 371 is connected to main steam bypass pipe 167. In this embodiment, the main steam bypass pipe 167 is branched off at a branch point 301, and the high temperature heat exchange section 211, the first medium temperature heat exchange section 221, and the first low temperature heat exchange section 231 are connected in this order, and at the confluence point 302. Connected to main steam bypass pipe 167. Thereby, the main steam first flow path 371 allows the fluid flowing into the heat storage device 200 from the main steam bypass pipe 167 to pass through the high temperature heat exchange section 211, the first medium temperature heat exchange section 221, and the first low temperature heat exchange section 231 in this order. and discharged from the heat storage device 200. During this time, the fluid passing through the main steam first flow path 371 exchanges heat in each heat storage layer and stores heat in each heat storage layer. When the temperature of the supplied fluid is higher than the melting point of the high temperature layer 210, the thermal energy of the fluid is stored in the high temperature layer 210, the intermediate temperature layer 220, and the low temperature layer 230 in this order. Note that the fluid discharged from the heat storage device 200 returns to the condenser 131 via the main steam bypass pipe 167.

The main steam bypass flow path 372 causes the fluid in the main steam bypass pipe 167 to bypass the heat storage device 200 . Note that the fluid that has bypassed the heat storage device 200 returns to the condenser 131 via the main steam bypass pipe 167. The main steam bypass flow path 372 branches at a branch point 301, bypasses the high temperature heat exchange section 211, the first medium temperature heat exchange section 221, and the first low temperature heat exchange section 231, and connects to the main steam bypass pipe 167 at the confluence point 302. join together.

The third main steam flow path 373 branches from the main steam bypass flow path 372, bypasses the high temperature heat exchange section 211, and joins the first main steam flow path 371. Thereby, the main steam third flow path 373 allows the fluid flowing into the heat storage device 200 from the main steam bypass pipe 167 to pass through the first medium temperature heat exchange section 221 and the first low temperature heat exchange section 231 in this order, and the fluid flowing into the heat storage device 200 discharge from. When the temperature of the supplied fluid is higher than the melting point of the intermediate temperature layer 220, the thermal energy of the fluid is stored in the intermediate temperature layer 220 and the low temperature layer 230 in this order. Note that the fluid discharged from the heat storage device 200 returns to the condenser 131 via the main steam bypass pipe 167.

Boiler exhaust flow path 351 is connected to boiler bleed pipe 165. The boiler exhaust flow path 351 branches from the boiler bleed pipe 165 at a branch point 303, connects the second medium temperature heat exchange section 222 and the second low temperature heat exchange section 232 in this order, and connects to the boiler bleed pipe 165 at a confluence point 304. do. Thereby, the boiler exhaust flow path 351 allows the fluid flowing into the heat storage device 200 from the boiler bleed pipe 165 to pass through the second medium temperature heat exchange section 222 and the second low temperature heat exchange section 232 in this order, and discharges it from the heat storage device 200. . The fluid passing through the boiler exhaust flow path 351 exchanges heat in each heat storage layer and stores heat in each heat storage layer. Note that the fluid discharged from the heat storage device 200 returns to the condenser 131 via the boiler bleed pipe 165.

Boiler exhaust bypass flow path 352 allows fluid in boiler bleed pipe 165 to bypass heat storage device 200 . Note that the fluid that has bypassed the heat storage device 200 returns to the condenser 131 via the boiler bleed pipe 165. The boiler exhaust bypass flow path 352 branches at a branch point 303, bypasses the second medium temperature heat exchange section 222 and the second low temperature heat exchange section 232, and joins the boiler exhaust flow path 351 at a confluence point 304.

The saturated water flow path 311 is connected to the saturated water pipe 161. It branches from the saturated water pipe 161 at a branch point 305 and connects to the saturated water pipe 161 at a confluence point 306 via the third low-temperature heat exchange section 233 . Thereby, the saturated water flow path 311 allows the fluid flowing into the heat storage device 200 from the saturated water pipe 161 to pass through the third low temperature heat exchange section 233 and is discharged from the heat storage device 200. The fluid passing through the saturated water flow path 311 exchanges heat with the low temperature layer 230 and stores heat in the low temperature layer 230 . Note that the fluid discharged from the heat storage device 200 returns to the condenser 131 via the saturated water pipe 161.

The saturated water bypass channel 312 returns the fluid in the saturated water pipe 161 to the condenser 131, bypassing the heat storage device 200. The saturated water bypass channel 312 branches at a branch point 305 , bypasses the third low-temperature heat exchange section 233 , and joins the saturated water channel 311 at a confluence point 306 . When the temperature of the supplied fluid is higher than the melting point of the low temperature layer 230, the thermal energy of the fluid is stored in the low temperature layer 230.

Moreover, each flow path is equipped with an on-off valve (valve). In this embodiment, the on-off valves include a main steam first on-off valve 376, a main steam second on-off valve 377, a main steam third on-off valve 378, an exhaust first on-off valve 356, and an exhaust second on-off valve 357. , a saturated water first on-off valve 316 , and a saturated water third on-off valve 317 .

The main steam first on-off valve 376 is provided downstream of the branch point 301 in the main steam first flow path 371 and controls the flow of fluid into the high temperature heat exchange section 211 .

The main steam third on-off valve 378 is provided downstream of the branch point of the main steam third flow path 373 and the main steam bypass flow path 372, and controls the inflow of fluid into the main steam third flow path 373.

The main steam second on-off valve 377 is provided downstream of the branch point of the main steam bypass flow path 372 and the main steam third flow path 373, and controls the inflow of fluid into the main steam bypass flow path 372.

The exhaust first opening/closing valve 356 is provided downstream of the branch point 303 in the boiler exhaust flow path 351 and controls the flow of fluid into the second medium temperature heat exchange section 222 .

The second exhaust opening/closing valve 357 is provided in the boiler exhaust bypass flow path 352 and controls the inflow of fluid into the boiler exhaust bypass flow path 352.

The first saturated water on-off valve 316 is provided downstream of the branch point 305 in the saturated water flow path 311 and controls the flow of fluid into the third low temperature heat exchange section 233 .

The third saturated water on-off valve 317 is provided in the saturated water bypass flow path 312 and controls the inflow of fluid into the saturated water bypass flow path 312 .

Each on-off valve is opened and closed according to a command from the control device 150, respectively. The control device 150 controls the fluid inflow path according to instructions input via the control console 151 or by detecting the temperature of the fluid flowing into the heat storage device 200 and opening and closing each on-off valve according to the temperature. control. For example, when controlling the opening and closing according to the temperature, the opening and closing of the opening and closing valve is controlled according to the temperature of the inflowing fluid so that heat is stored in the heat storage layer of the heat storage material that is lower than the temperature and has the closest melting point. do. A specific example of the on-off valve control will be described later.

As the heat storage material used in each heat storage layer, for example, a latent heat storage material that utilizes phase transformation latent heat of a substance can be used. The temperature characteristics of the heat storage layer are characteristics determined based on the melting temperature (melting point) of this latent heat storage material. Further, the heat storage material used for each heat storage layer may be an alloy material having a heat storage temperature (melting point) exceeding 500°C. Furthermore, a structure in which this alloy material is included in ceramics or metal may be used. For example, latent heat storage microcapsules disclosed in International Publication No. 2017/200021 can be used.

By using a heat storage material having a structure in which a latent heat storage material is included in ceramic or the like in each heat storage layer, it is possible to obtain a heat storage section that operates only by heat input and output, utilizing phase transformation of the latent heat storage material. Since the melting temperature can be controlled by the composition of the latent heat storage material during manufacture, the temperature range of the fluid can be set more precisely.

The heat storage material used for each heat storage layer is selected according to the temperature range of thermal energy stored in the heat storage device 200, and has a melting point within the temperature range. Further, the heat storage capacity of each heat storage layer is determined based on the estimated amount of surplus thermal energy. Thereby, the generated surplus thermal energy can be efficiently stored without wasting it. This also leads to optimization of capital investment.

Note that in the heat storage device 200, a flow path for connecting heat exchange sections in the same heat storage layer is further provided as a flow path used during heat recovery, which will be described later. As a flow path for heat recovery, the heat storage device 200 includes a first heat recovery pipe 410 that passes through the high temperature heat exchange section 211 of the high temperature layer 210, and a first intermediate temperature heat exchange section 221 and a second intermediate temperature heat exchange section of the intermediate temperature layer 220. A second heat recovery pipe 420 that passes through the section 222, and a third heat recovery pipe 430 that passes through the first low temperature heat exchange section 231, the second low temperature heat exchange section 232, and the third low temperature heat exchange section 233 of the low temperature layer 230. Equipped with

The first heat recovery pipe 410 recovers heat only from the high temperature layer 210 by passing the fluid only through the high temperature layer 210 during heat recovery. The second heat recovery pipe 420 recovers heat only from the intermediate temperature layer 220 by passing the fluid only through the intermediate temperature layer 220. The third heat recovery tube 430 recovers heat only from the low temperature layer 230 by passing the fluid only through the low temperature layer 230 .

The first heat recovery pipe 410, the second heat recovery pipe 420, and the third heat recovery pipe 430 each have a first heat recovery on-off valve 411 and a second heat recovery on-off valve 421 on the inlet side of each heat storage layer. , and a third heat recovery on/off valve 431 are provided. The opening and closing of these heat recovery on-off valves 411, 421, and 431 is controlled by the control device 150. During heat recovery, the control device 150 controls the opening and closing of these heat recovery on/off valves 411, 421, and 431 so that heat can be recovered from the heat storage layer in the optimal temperature range.

[Control of on-off valve by control device]
Hereinafter, control of the on-off valve by the control device 150 in the power generation plant 100 including the heat storage device 200 of this embodiment will be explained.

The control device 150 of the present embodiment stores surplus heat energy in the form of steam generated when the power generation plant 100 is started, stopped, or during pumping operation in the heat storage device 200 for each temperature range. Controls the opening and closing of each on-off valve.

For example, the power generation plant 100 of the present embodiment has a startup operation mode that is an operation mode at startup, a normal operation mode that is an operation mode during normal operation, a pumped storage operation mode that is an operation mode during pumping operation, and a stop operation mode. It has a stop operation mode, which is an operation mode when the system is in use, and an emergency operation mode, which is an operation mode when a system failure occurs. Among these, surplus thermal energy in the form of steam is generated during operation in the startup operation mode, pumping operation mode, stop operation mode, and emergency operation mode.

Hereinafter, control of each on-off valve in the power generation plant 100 for storing heat in the heat storage device 200 of the present embodiment by the control device 150 during the startup operation mode, pumping operation mode, stop operation mode, and emergency operation mode will be described. Opening/closing control will be explained.

As described above, in this embodiment, the control device 150 controls the on-off valves to store heat in different heat storage layers depending on the temperature of the surplus thermal energy. Here, in the start-up operation mode, as shown in FIG. The temperature of the output steam increases monotonically over time. Further, in the stop operation mode, as shown in FIG. 1(b), events such as the end of equilibrium and stoppage occur, and the temperature of the steam output from the boiler 110 monotonically decreases. On the other hand, in the pumping operation mode, as shown in FIG. 2, there are events such as the end of equilibrium and equilibrium, during which the temperature of the steam output from the boiler 110 is approximately constant.

Note that in this specification, balance refers to a state in which the boiler heat output per unit time and the turbine generator load are balanced. In addition, the end of equilibrium refers to the point in time when the boiler heat output becomes dominant and a difference occurs between the boiler heat output and the turbine generator load, which were in balance after receiving the stop instruction.

In this embodiment, in order to realize heat storage according to the temperature range, the control device 150 divides the startup operation mode and the stop operation mode into a plurality of operation modes according to the steam temperature, and controls the opening and closing differently for each operation mode. I do. In addition, since the steam temperature is substantially constant in the pumping operation mode, opening/closing control is performed as one operation mode.

For example, in the present embodiment, in the start-up operation mode, as shown in FIG. The starting operation mode, from equilibrium to normal operation, is the third starting operation mode. Moreover, in the stop operation mode, as shown in FIG. 1(b), the period from the end of equilibrium to the stop is set as the first stop operation mode.

Note that each operation mode is changed by receiving instructions from the operator via the control console 151. Note that the control device 150 may make the determination based on the temperature detected by a temperature sensor placed in each pipe. For example, in the start-up operation mode, from the first start-up operation mode to the second start-up operation mode, the temperature detected by the temperature sensor 187 arranged in the main steam bypass pipe 167 etc. is set to a predetermined threshold (for example, 500°C ) or above, the configuration may be such that the transition occurs.

In this embodiment, opening and closing of on-off valves provided in each pipe of the power generation plant 100 is controlled according to the operation mode. Furthermore, the opening and closing of the on-off valves provided in each flow path of the heat storage device 200 is controlled according to the temperature of the fluid at the inlet side of each flow path detected by temperature sensors 181, 185, and 187.

The open/close states of each on-off valve for each operation mode are stored in advance in the storage device of the control device 150 as an open/close state table.

In the following description, it is assumed that each on-off valve is in a closed state in its initial state unless otherwise specified.

Time charts of opening and closing of each on-off valve by the control device 150 for each operation mode and event are shown in FIGS. 5 and 6. Further, FIGS. 7A to 9 are diagrams illustrating the opening and closing states of the on-off valves in the power generation plant 100 for each operation mode.

Upon receiving a startup command from the control console 151 or the like, that is, a command to operate in the first startup operation mode, the control device 150 activates the boiler startup bleed air adjustment valve 175 and the like, as shown in FIGS. 5 and 7(a). , and the main steam bypass on-off valve 177 to open these on-off valves. Thereby, the steam generated in the boiler 110 is guided to the heat storage device 200 via the boiler bleed pipe 165 and the main steam bypass pipe 167.

Next, upon receiving the command to operate in the second start-up operation mode, the control device 150 issues a close command to the boiler start-up bleed air adjustment valve 175, as shown in FIGS. 5 and 7(b). An opening command is issued to the steam on-off valve 172 and the reheat steam on-off valve 174. Thereby, the steam generated by the boiler 110 is supplied to the steam turbine 120. At this time, a portion of the surplus steam is guided to the heat storage device 200 via the main steam bypass pipe 167.

Thereafter, upon receiving a command to operate in the third start-up operation mode, the control device 150 outputs a close command to the main steam bypass on-off valve 177 and returns it to the closed state, as shown in FIGS. 5 and 8(a). do. Thereby, the steam generated by the boiler 110 is supplied to the steam turbine 120. After that, when the mode shifts to normal operation mode, steam and water circulate between the boiler 110, the steam turbine 120, and the water supply line 130, and the generator 109 is driven.

Further, upon receiving a command to operate in the first stop operation mode, the control device 150 outputs an open command to the main steam bypass on-off valve 177, as shown in FIGS. 5 and 8(b), and returns it to the open state. do. As a result, the steam generated by the boiler 110 is supplied to the steam turbine 120 similarly to the second start-up operation mode. At this time, a portion of the surplus steam is guided to the heat storage device 200 via the main steam bypass pipe 167.

Further, when receiving a command to operate in the pumping operation mode during normal operation, the control device 150 controls the main steam on-off valve 172 and the reheat steam on-off valve 174, as shown in FIGS. 6 and 9. Leave it in the open state. Additionally, an open command is output to the main steam bypass on-off valve 177 to open it. Then, the boiler startup bleed air adjustment valve 175 is left in the closed state. Thereby, the steam generated by the boiler 110 is supplied to the steam turbine 120. In addition, surplus steam is guided to the heat storage device 200 via the main steam bypass pipe 167.

Next, control of the on-off valve of the heat storage device 200 by the control device 150 in the first start operation mode, second start operation mode, first stop operation mode, and pumping operation mode in which fluid is guided to the heat storage device 200 will be explained. . As described above, the control device 150 controls the opening and closing of each on-off valve according to the temperature of the generated surplus thermal energy in each operation mode. The opening and closing of each on-off valve is controlled so that the generated surplus thermal energy flows in the form of a fluid into a flow path that first passes through a heat storage section having temperature characteristics in the temperature range to which the surplus thermal energy belongs.

Here, control of the on-off valve of the heat storage device 200 in the emergency operation mode will also be explained. Note that the emergency operation mode is an operation mode for emergencies such as system failure.

In addition, since the control of the on-off valves of the heat storage device 200 during heat storage is explained here, the heat recovery on-off valves 411, 421, and 431 are omitted. During heat storage, these heat recovery on/off valves 411, 421, and 431 are basically kept closed.

In the first startup operation mode, as shown in FIG. 1(a), the steam temperature is 400°C or more and less than 500°C. Therefore, the control device 150 controls the opening and closing of the on-off valve so that the heat flows into the flow path that first passes through the heat storage section having temperature characteristics in this temperature range.

That is, as shown in FIGS. 5 and 10(a), the control device 150 opens the main steam third on-off valve 378, the exhaust first on-off valve 356, and the saturated water first on-off valve 316, and closes other main steam on-off valves. The first on-off valve 376, the second main steam on-off valve 377, the second exhaust on-off valve 357, and the third saturated water on-off valve 317 are closed. Thereby, as shown by the thick line in this figure, the fluid below 500° C. flowing into the heat storage device 200 is guided to the heat exchange section in the intermediate temperature layer 220 and the low temperature layer 230.

The fluid flowing in from the main steam bypass pipe 167 enters the first intermediate temperature heat exchange section 221 via the main steam bypass passage 372 and the third main steam passage 373. After heat exchange in the first medium temperature heat exchange section 221, the fluid whose temperature has decreased flows into the first low temperature heat exchange section 231. After heat exchange in the first low-temperature heat exchange section 231, the fluid whose temperature has further decreased is discharged from the heat storage device 200 to the condenser 131 via the main steam bypass pipe 167.

The fluid that has flowed into the boiler exhaust flow path 351 from the boiler bleed pipe 165 enters the second medium temperature heat exchange section 222 . After heat exchange in the second medium temperature heat exchange section 222, the fluid whose temperature has decreased flows into the second low temperature heat exchange section 232. After heat exchange in the second low-temperature heat exchange section 232, the fluid whose temperature has further decreased is discharged from the heat storage device 200 to the condenser 131 via the boiler bleed pipe 165.

Note that water always flows through the saturated water pipe 161 that leads water from the brackish water separator 113 to the condenser 131. That is, a fluid of 100° C. or lower flows. Therefore, the fluid flowing into the saturated water flow path 311 connected to the saturated water pipe 161 enters the third low temperature heat exchange section 233. After heat exchange in the third low-temperature heat exchange section 233, the fluid whose temperature has decreased is discharged from the heat storage device 200 to the condenser 131 via the saturated water pipe 161.

In the second starting operation mode, as shown in FIG. 1(a), the steam temperature is 500° C. or higher. Additionally, the boiler startup bleed air adjustment valve 175 is closed. Therefore, as shown in FIGS. 5 and 10(b), the control device 150 opens the main steam first on-off valve 376 and the saturated water first on-off valve 316, opens the main steam second on-off valve 377, and opens the main steam second on-off valve 377. The three on-off valves 378, the first exhaust on-off valve 356, the second exhaust on-off valve 357, and the third saturated water on-off valve 317 are closed. As a result, as shown by the thick line in this figure, the fluid at 500° C. or higher flowing into the heat storage device 200 is guided to the heat exchange portions in the high temperature layer 210, the intermediate temperature layer 220, and the low temperature layer 230. Further, water at a temperature of less than 100° C. flowing from the brackish water separator is guided to the low temperature layer 230 as in the first startup operation mode.

The fluid that has flowed into the main steam first flow path 371 from the main steam bypass pipe 167 enters the high temperature heat exchange section 211 . After heat exchange in the high temperature heat exchange section 211, the fluid whose temperature has decreased enters the first medium temperature heat exchange section 221. After heat exchange in the first medium temperature heat exchange section 221, the fluid whose temperature has decreased flows into the first low temperature heat exchange section 231. After heat exchange in the first low-temperature heat exchange section 231, the fluid whose temperature has further decreased is discharged from the heat storage device 200 to the condenser 131 via the main steam bypass pipe 167.

Note that the fluid that has flowed into the saturated water flow path 311 from the saturated water pipe 161 that leads water from the brackish water separator 113 to the condenser 131 enters the third low-temperature heat exchange section 233 and enters the third After heat exchange in the low-temperature heat exchange section 233, the water is discharged to the condenser 131 through the saturated water pipe 161.

FIG. 11(a) shows the state of the on-off valve in the first stop operation mode. As shown in FIG. 1(b), the steam temperature is 500° C. or higher in the first stop operation mode. Therefore, as shown in FIGS. 5 and 11(a), the control device 150 controls the opening and closing of each on-off valve as in the second start-up operation mode.

Figure 11(b) shows the on-off valve in the pumping operation mode. As shown in FIG. 2, the steam temperature is 500° C. or higher in the pumping operation mode. Therefore, as shown in FIGS. 6 and 11(b), the control device 150 basically controls the opening and closing of each on-off valve in the same manner as in the second starting operation mode. However, the saturated water first on-off valve 316 is closed.

Figure 12 shows the on-off valve in the emergency operation mode. In the emergency operation mode, it is necessary to flow fluid into the condenser 131 as quickly as possible regardless of the steam temperature to lower the overall temperature inside the power generation plant 100. Therefore, in this case, the control device 150 performs control to bypass the heat storage device 200 and guide the fluid to the condenser 131 without guiding the fluid to the heat storage device 200.

That is, as shown in FIG. 12, the main steam second on-off valve 377, the exhaust second on-off valve 357, and the saturated water third on-off valve 317 are opened, and the other on-off valves, the main steam first on-off valve 376, the main The third steam on-off valve 378, the first exhaust on-off valve 356, and the first saturated water on-off valve 316 are closed. As a result, as shown by the bold line in this figure, the fluid does not flow into the heat exchange section within the heat storage device 200 but is discharged to the condenser 131.

The temperature range of each heat storage layer is determined according to the steam temperature at the time of events such as ignition, start of ventilation, addition, balance, end of balance, and stop during each operation mode. Further, the heat storage capacity of each heat storage layer is the capacity capable of storing the amount of surplus thermal energy generated during each heat storage period.

As described above, the power generation plant 100 of the present embodiment includes piping that guides a fluid having thermal energy to the heat storage device 200 and pipes that are provided to guide the fluid to the heat storage device 200 only when surplus thermal energy is generated. and a control device 150 that controls the on-off valve. Further, the heat storage device 200 includes a plurality of heat storage layers each having temperature characteristics in a plurality of different temperature ranges, a flow path that allows fluid to pass through each heat storage layer, and an on-off valve provided in the flow path. When controlling the fluid to be guided to the heat storage device 200, the control device 150 controls the thermal energy of the fluid flowing into the heat storage device 200 to be stored in a heat storage layer according to the temperature range of the fluid.

Therefore, according to this embodiment, surplus thermal energy generated in the power generation plant 100 can be stored in a manner that can be used efficiently.

In particular, according to the present embodiment, surplus thermal energy generated during the period when the power generation plant 100 is started and stopped when the boiler heat output exceeds the turbine generator load is appropriately controlled according to the steam temperature and the saturated water temperature. Heat can be stored in the heat storage layer in the temperature range.

Although the temperature of the surplus steam is low during the period until it is annexed at startup, the overall amount of heat is large. In the conventional power plant 100, all surplus steam generated is returned to the condenser 131. Therefore, not only is there a lot of waste, but also a large receiving capacity is required on the condenser 131 side. However, according to the present embodiment, most of the heat amount of the fluid returned to the condenser 131 is stored in the heat storage device 200, so it is possible to suppress the capacity of the condenser 131. Therefore, equipment costs can be reduced.

Furthermore, even during pumping operation in which the generator load of the steam turbine 120 is suppressed below the heat output of the boiler 110, surplus thermal energy generated by the boiler 110 during that period can be efficiently stored.

Further, in the heat storage device 200 of the present embodiment, latent heat storage materials that utilize phase transformation latent heat of substances and have different melting points are used as the heat storage materials of each heat storage layer. Thereby, the generated surplus thermal energy can be stored in each heat storage layer according to the melting point of the latent heat storage material forming the heat storage layer. Further, since such a latent heat storage material is used, a heat storage section that operates only by heat input/output and is capable of high-density heat storage can be realized. Furthermore, by using an alloy material with a high melting point as the latent heat storage material, a high heat storage temperature can be achieved. Thereby, for example, high temperature fluid such as main steam can be stored at its high temperature. Additionally, it becomes possible to generate steam in the highest temperature range during heat recovery.

Furthermore, in the heat storage device 200 of the present embodiment, a flow path is provided in accordance with the temperature of the fluid flowing into the heat storage device 200 so that the fluid flows into a heat storage layer of a heat storage material having a melting point lower than the temperature and closest to the temperature, Controls the opening and closing of the on-off valve. Therefore, heat storage for each of a plurality of temperature ranges can be realized with a simple configuration.

Furthermore, each flow path in the heat storage device 200 is provided so that the fluid that has passed through the heat storage layer also passes through the heat storage layer, if there is a heat storage layer made of a heat storage material with the next highest melting point after the heat storage material. It will be done. That is, by arranging heat storage layers in the order of high temperature, medium temperature, and low temperature in one flow path, the heat of the fluid can be completely recovered. According to the power generation plant 100 having the heat storage device 200 of this embodiment, efficient operation of the power generation plant 100 can be realized, including utilizing the recovered thermal energy for startup and the like.

Furthermore, according to the heat storage device 200 of this embodiment, a heat storage layer having performance that is just over or under for each temperature range of the fluid is provided. For example, when using the heat storage for surplus thermal energy at startup, the temperature range of each heat storage layer is determined according to the steam temperature after a predetermined period of time has elapsed after the boiler 110 is ignited. Furthermore, the heat storage capacity of each heat storage layer is determined according to the amount of surplus thermal energy after each elapse of time.

This enables efficient heat recovery. For example, if a heat storage section is prepared in accordance with the assumed highest temperature of the fluid flowing into the heat storage device 200, the heat recovery of medium-temperature or low-temperature fluid will be overspecified, resulting in much waste. However, according to the present embodiment, such waste can be avoided because heat is stored in an appropriate heat storage layer for each temperature range.

As explained above, in the power generation plant 100 equipped with the heat storage device 200 of the present embodiment, in order to completely recover the heat of the fluid in the heat storage device 200, the amount of fluid discharged from the heat storage device 200 to the condenser 131 is temperature becomes lower. Therefore, the amount of heat returned to the condenser 131 can be suppressed.

<<Second embodiment>>
Next, a second embodiment of the present invention will be described. In the first embodiment, the heat storage device 200 includes a main steam bypass pipe 167 branching from the main steam pipe 162, and stores the heat of the fluid passing through the main steam bypass pipe 167. However, in this embodiment, a reheat steam bypass pipe branching from the high temperature reheat steam pipe 164 is further provided. The heat storage device 200 also stores the heat of the fluid passing through this reheat steam bypass pipe.

The present embodiment will be described below, focusing on the configuration different from the first embodiment.

FIG. 13(a) is a fluid system diagram of the power generation plant 101 of this embodiment. The power generation plant 101 of this embodiment has the configuration of the power generation plant 100 of the first embodiment, and further includes a reheat steam bypass pipe 168 branching from the high temperature reheat steam pipe 164, and a high pressure steam bypass pipe 168 branching from the main steam pipe 162. A high-pressure steam turbine bypass pipe 169 that bypasses the turbine 121 and connects to the low-temperature reheat steam pipe 163 is provided. That is, in this embodiment, the main steam pipe 162 and the low temperature reheat steam pipe 163 are connected to each other via the high pressure steam turbine bypass pipe 169.

The reheat steam bypass pipe 168 is provided with a reheat steam bypass on-off valve 178 . The high-pressure steam turbine bypass pipe 169 is provided with a high-pressure steam turbine bypass on-off valve 179 . Further, the reheat steam bypass pipe 168 is provided with a temperature sensor 188 that detects the temperature of the steam passing therethrough.

Further, the heat storage device 201 of this embodiment is arranged on the saturated water pipe 161, the boiler extraction pipe 165, the main steam bypass pipe 167, and the reheat steam bypass pipe 168. The steam after heat exchange in the heat storage device 201 is introduced into the condenser 131.

In the present embodiment, similarly to the first embodiment, the control device 150 receives instructions from the outside (control console 151 placed in the power plant, etc.) or the temperature control device installed in the power plant 101. The opening and closing of each on-off valve is controlled according to signals from various sensors including sensors 181, 185, 187, and 188.

The other configurations are the same as the configurations with the same name in the first embodiment, so their description will be omitted here. The same applies hereinafter in this embodiment.

[Heat storage device]
Next, the heat storage device 201 of this embodiment will be explained using FIG. 13(b).

Like the heat storage device 200 of the first embodiment, the heat storage device 201 of this embodiment also includes a plurality of heat storage layers each made of a heat storage material having temperature characteristics (melting points) in different temperature ranges, and a plurality of heat storage layers provided within each heat storage layer. a heat exchange section connected to the heat storage device 201 and a flow path that guides the fluid in the piping to the heat exchange section or bypasses the heat storage device 200 and guides the fluid in the piping to the condenser 131; It includes an on-off valve (valve) that regulates the inflow of fluid into the flow path.

Similarly to the first embodiment, the heat storage device 201 changes the path through which the fluid passes depending on the temperature of the fluid flowing into the heat storage device 201 by opening and closing the on-off valve according to a command from the control device 150. and store heat in an appropriate temperature range.

Also in this embodiment, similarly to the first embodiment, a case will be described using as an example a case where the heat storage layer includes a high temperature layer 210, an intermediate temperature layer 220, and a low temperature layer 230.

Further, as the heat exchange parts, similarly to the first embodiment, a high temperature heat exchange part 211 arranged in the high temperature layer 210, a first medium temperature heat exchange part 221 and a second medium temperature heat exchange part 221 arranged in the medium temperature layer 220 are used. It includes an exchange section 222, and a first low temperature heat exchange section 231, a second low temperature heat exchange section 232, and a third low temperature heat exchange section 233 arranged in the low temperature layer 230. Further, in this embodiment, the high temperature layer 210 includes a reheat high temperature heat exchange section 214, the intermediate temperature layer 220 includes a reheat intermediate temperature heat exchange section 224, and the low temperature layer 230 includes a reheat low temperature heat exchange section 234.

Furthermore, as in the first embodiment, the flow paths used during heat storage include a main steam first flow path 371, a main steam bypass flow path 372, a main steam third flow path 373, and a boiler exhaust flow path 351. , a boiler exhaust bypass flow path 352, a saturated water flow path 311, and a saturated water bypass flow path 312. The heat storage device 201 of this embodiment further includes a first reheated steam flow path 381, a reheated steam bypass flow path 382, and a third reheated steam flow path 383.

The reheated steam first flow path 381 is connected to the reheated steam bypass pipe 168. In this embodiment, the reheat steam bypass pipe 168 branches off at a branch point 307, and the reheat high temperature heat exchange section 214, the reheat medium temperature heat exchange section 224, and the reheat low temperature heat exchange section 234 are connected in this order, and the confluence point At 308 , it is connected to the reheat steam bypass pipe 168 . Thereby, the reheat steam first flow path 381 transfers the fluid flowing into the heat storage device 201 from the reheat steam bypass pipe 168 to the reheat high temperature heat exchange section 214, the reheat medium temperature heat exchange section 224, and the reheat low temperature heat exchange section 234. The steam is discharged from the heat storage device 201, passed through the reheat steam bypass pipe 168, and returned to the condenser 131. During this time, the fluid passing through the first reheated steam flow path 381 exchanges heat in each heat storage layer and stores heat in each heat storage layer. When the temperature of the supplied fluid is higher than the melting point of the high temperature layer 210, the thermal energy of the fluid is stored in the high temperature layer 210, the intermediate temperature layer 220, and the low temperature layer 230 in this order.

The reheat steam bypass passage 382 returns the fluid that has flowed through the reheat steam bypass pipe 168 to the condenser 131 by bypassing the heat storage device 201 . The reheat steam bypass flow path 382 branches at a branch point 307, bypasses the reheat high temperature heat exchange section 214, the reheat medium temperature heat exchange section 224, and the reheat low temperature heat exchange section 234, and bypasses the reheat steam bypass at the confluence point 308. It joins pipe 168.

The third reheat steam flow path 383 branches from the reheat steam bypass flow path 382, bypasses the reheat high temperature heat exchange section 214, and joins the first reheat steam flow path 381. Thereby, the reheat steam third flow path 383 allows the fluid flowing into the heat storage device 201 from the reheat steam bypass pipe 168 to pass through the reheat medium temperature heat exchange section 224 and the reheat low temperature heat exchange section 234 in this order. 201 and returns to the condenser 131 via the reheat steam bypass pipe 168. When the temperature of the supplied fluid is higher than the melting point of the intermediate temperature layer 220, the thermal energy of the fluid is stored in the intermediate temperature layer 220 and the low temperature layer 230 in this order.

In addition, as in the first embodiment, the heat storage device 201 includes a main steam first on-off valve 376, a main steam second on-off valve 377, a main steam third on-off valve 378, and an exhaust first on-off valve 356 as on-off valves. , a second exhaust on-off valve 357, a first saturated water on-off valve 316, and a third saturated water on-off valve 317. Furthermore, a reheat steam first on-off valve 386, a second reheat steam on-off valve 387, a third reheat steam on-off valve 388, a first heat recovery on-off valve 411, a second heat recovery on-off valve 421, A third heat recovery on/off valve 431 is provided.

The first reheat steam on-off valve 386 is provided downstream of the branch point 307 in the first reheat steam flow path 381 and controls the flow of fluid into the reheat high temperature heat exchange section 214 .

The third reheat steam opening/closing valve 388 is provided downstream of the branch point of the third reheat steam flow path 383 and the reheat steam bypass flow path 382, and is configured to prevent fluid from flowing into the third reheat steam flow path 383. control.

The second reheat steam on-off valve 387 is provided downstream of the branch point of the reheat steam bypass flow path 382 and the third reheat steam flow path 383, and prevents fluid from flowing into the reheat steam bypass flow path 382. Control.

Also in this embodiment, each on-off valve is opened and closed in response to a command from the control device 150 that is issued in accordance with the temperature of the fluid flowing through the installed flow path, as in the first embodiment. Note that the heat storage material and the like used in each heat storage layer are the same as those in the first embodiment, so the description thereof will be omitted here.

In addition, each flow path used during heat recovery, the first heat recovery pipe 410, the second heat recovery pipe 420, and the third heat recovery pipe 430, respectively, further includes a reheat high temperature heat exchange section 214, a reheat medium temperature heat exchange section 224 , and a reheat low temperature heat exchange section 234 .

[Control of on-off valve by control device]
Hereinafter, control of on-off valves by the control device 150 in the power generation plant 101 including the heat storage device 201 of this embodiment will be explained. Each operation mode is the same as in the first embodiment.

Also in this embodiment, the opening and closing of the on-off valves provided in each pipe of the power generation plant 101 is controlled according to the operation mode. Furthermore, opening and closing of the on-off valves provided in each flow path of the heat storage device 201 is controlled according to the temperature of the fluid on the inlet side of each flow path. Further, the open/close states of each on-off valve for each operation mode are stored in advance in the storage device of the control device 150 as an open/close state table. In the initial state, each on-off valve is in a closed state unless otherwise specified.

FIGS. 14 and 15 show time charts of opening and closing of each on-off valve for each operation mode and event.

The opening/closing timing of the on-off valve included in the power generation plant 100 of the first embodiment is the same as in the first embodiment. The reheated steam bypass on-off valve 178, the first reheated steam on-off valve 386, the second reheated steam on-off valve 387, and the third reheated steam on-off valve 388 of the present embodiment are the same as those of the first embodiment. Same as 177, 376, 377, 378. Furthermore, the high-pressure steam turbine bypass on-off valve 179 is kept open when storing heat in the heat storage device 201 . That is, it is opened and closed at the same timing as the reheat steam bypass on-off valve 178.

Also in this embodiment, the control device 150 controls opening and closing of each on-off valve according to instructions from the control console 151 and the like. Also in this embodiment, like the first embodiment, the control device 150 may control opening and closing according to the detection results of each temperature sensor. The open/close states of each on-off valve for each operation mode are stored in advance in the storage device of the control device 150 as an open/close state table.

Next, control of the on-off valve of the heat storage device 201 in the first start operation mode, second start operation mode, first stop operation mode, and pumping operation mode in which fluid is introduced to the heat storage device 201 will be explained. Here, control of the on-off valve of the heat storage device 201 in the emergency operation mode will also be explained.

In addition, in this embodiment as well, since the control of the on-off valves of the heat storage device 201 during heat storage is explained, the heat recovery on-off valves 411, 421, and 431 will be omitted. During heat storage, these heat recovery on/off valves 411, 421, and 431 are basically kept closed.

During the first startup operation mode, the control device 150 controls the main steam third on-off valve 378, the reheat steam third on-off valve 388, the exhaust first on-off valve 356, and the saturation The water first on-off valve 316 is opened, and the other main steam first on-off valves 376, main steam second on-off valves 377, reheated steam first on-off valves 386, reheated steam second on-off valves 387, and exhaust second on-off valves. The valve 357 and the third saturated water on-off valve 317 are closed. Thereby, as shown by the thick line in this figure, the fluid below 500° C. flowing into the heat storage device 200 is guided to the heat exchange section in the intermediate temperature layer 220 and the low temperature layer 230.

The fluid flowing from the reheat steam bypass pipe 168 enters the reheat intermediate temperature heat exchange section 224 through the reheat steam bypass flow path 382 and the third reheat steam flow path 383. After heat exchange in the reheat medium temperature heat exchange section 224, the fluid whose temperature has decreased flows into the reheat low temperature heat exchange section 234. After heat exchange in the reheat low-temperature heat exchange section 234, the fluid whose temperature has further decreased is discharged from the heat storage device 201 to the condenser 131 via the reheat steam bypass pipe 168.

During the second startup operation mode, the control device 150 operates the main steam first on-off valve 376, the reheat steam first on-off valve 386, and the saturated water first on-off valve 316, as shown in FIGS. 14 and 16(b). Open, main steam second on-off valve 377, main steam third on-off valve 378, reheated steam second on-off valve 387, reheated steam third on-off valve 388, exhaust first on-off valve 356, exhaust second on-off valve 357. , and the third saturated water on-off valve 317 is closed. Thereby, as shown by the thick line in this figure, the fluid at 500° C. or higher flowing into the heat storage device 201 is guided to the heat exchange portions in the high temperature layer 210, the intermediate temperature layer 220, and the low temperature layer 230. Further, water at a temperature of less than 100° C. flowing from the brackish water separator is guided to the low temperature layer 230 as in the first startup operation mode.

The fluid flowing into the reheat steam first flow path 381 from the reheat steam bypass pipe 168 enters the reheat high temperature heat exchange section 214 . After heat exchange in the reheat high temperature heat exchange section 214, the fluid whose temperature has decreased enters the reheat medium temperature heat exchange section 224. After heat exchange in the reheat medium temperature heat exchange section 224, the fluid whose temperature has decreased flows into the reheat low temperature heat exchange section 234. After heat exchange in the reheat low-temperature heat exchange section 234, the fluid whose temperature has further decreased is discharged from the heat storage device 201 to the condenser 131 via the reheat steam bypass pipe 168.

FIG. 17(a) shows the state of the on-off valve in the first stop operation mode. As shown in FIGS. 14 and 17(a), the control device 150 controls the opening and closing of each on-off valve as in the second starting operation mode.

Figure 17(b) shows the on-off valve in the pumping operation mode. As shown in FIGS. 15 and 17(b), the control device 150 basically controls the opening and closing of each on-off valve in the same manner as in the second starting operation mode. However, the saturated water first on-off valve 316 is closed.

Figure 18 shows the opening/closing valve in emergency operation mode. In the emergency operation mode, the control device 150 controls the fluid to bypass the heat storage device 201 and lead it to the condenser 131 without leading the fluid to the heat storage device 201, regardless of the steam temperature.

That is, as shown in FIG. 18, the main steam second on-off valve 377, the reheat steam second on-off valve 387, the exhaust second on-off valve 357, and the saturated water third on-off valve 317 are opened, and the other on-off valves are Close the main steam first on-off valve 376, main steam third on-off valve 378, reheat steam first on-off valve 386, reheat steam third on-off valve 388, exhaust first on-off valve 356, and saturated water first on-off valve 316. shall be. As a result, as shown by the thick line in this figure, the fluid does not flow into the heat exchange section in the heat storage device 201, but is discharged to the condenser 131.

In each operation mode, the flow of fluid flowing into the heat storage device 201 from the main steam bypass pipe 167, boiler bleed pipe 165, and saturated water pipe 161 is the same as in the first embodiment.

As explained above, in addition to the power generation plant 100 of the first embodiment, the power generation plant 101 of this embodiment acquires surplus thermal energy from the high temperature reheat steam pipe 164 and stores it in the heat storage device 201.

Therefore, in addition to the effects of the first embodiment, according to the present embodiment, surplus steam can be efficiently stored even during FCB (Fast Cut Back) operation, for example.

Generally, during FCB operation, a faster load change is required than during normal stoppage, and the amount of heat of excess steam is large. In the conventional power plant 100, when the FCB function is provided, all generated surplus steam is returned to the condenser 131. Therefore, not only is there a lot of waste, but also a large receiving capacity is required on the condenser 131 side. In order to realize a large receiving capacity of the condenser 131, extensive construction is required. However, according to this embodiment, most of the heat amount of the fluid returned to the condenser 131 is stored in the heat storage device 201, so the performance of the condenser 131 is lower than that of the condenser 131 used in the case without the FCB function. It can be roughly equivalent to . Therefore, according to this embodiment, equipment costs can be further reduced.

<Modification 1>
[Modified example of heat storage device]
In each of the embodiments described above, the heat storage devices 200 and 201 control the opening and closing of the on-off valves according to predetermined events. However, it is not limited to this. For example, conversely, a temperature threshold value may be set according to the temperature range of the heat storage layer, and the control device 150 may control opening and closing of the on-off valve according to the temperature threshold value.

This modification will be explained using the power generation plant 100 and the heat storage device 200 of the first embodiment as examples.

As shown in FIG. 19(a), the heat storage device 202 of this modification has the structure of the heat storage device 200 of the first embodiment, and further includes a main steam fourth flow path 374 and a main steam fourth on-off valve 379. , a fourth boiler exhaust flow path 354, and a fourth exhaust opening/closing valve 359. Note that the heat recovery on/off valves 411, 421, and 431 are omitted here. The same applies to each modification of the heat storage device 200 below.

The main steam fourth flow path 374 branches from the main steam bypass flow path 372, bypasses the high temperature heat exchange section 211 and the first medium temperature heat exchange section 221, and joins the main steam first flow path 371. Thereby, the main steam fourth flow path 374 allows the fluid flowing into the heat storage device 202 from the main steam bypass pipe 167 to pass through the first low-temperature heat exchange section 231 and is discharged from the heat storage device 202. The water is then returned to the condenser 131.

The main steam fourth on-off valve 379 is provided downstream of the branch point of the main steam fourth flow path 374 and the main steam bypass flow path 372, and controls the inflow of fluid into the main steam fourth flow path 374.

The fourth boiler exhaust flow path 354 branches from the boiler exhaust bypass flow path 352, bypasses the second medium temperature heat exchange section 222, and joins the boiler exhaust flow path 351. Thereby, the boiler exhaust fourth flow path 354 allows the fluid flowing into the heat storage device 202 from the boiler bleed pipe 165 to pass through the second low temperature heat exchange section 232, is discharged from the heat storage device 202, and passes through the boiler bleed pipe 165. , and returned to the condenser 131.

The fourth exhaust opening/closing valve 359 is provided downstream of the branch point of the fourth boiler exhaust flow path 354 and the boiler exhaust bypass flow path 352, and controls the inflow of fluid into the fourth boiler exhaust flow path 354.

The control device 150 controls opening and closing of each on-off valve according to the detection results of a temperature sensor 187 provided in the main steam bypass pipe 167 and a temperature sensor 185 provided in the boiler bleed pipe 165. For example, the timing of opening/closing control when the steam temperature increases monotonically is shown in FIGS. 19(b) and 19(c). Note that since the explanation is for heat storage, the main steam second on-off valve 377 and the exhaust second on-off valve 357 are omitted in these figures.

As shown in FIG. 19(b), when the temperature detected by the temperature sensor 187 is less than 400°C, the main steam fourth on-off valve 379 is opened in each flow path connected to the main steam bypass pipe 167, The other on-off valves, the main steam first on-off valve 376, the second main steam on-off valve 377, and the third main steam on-off valve 378 are closed. As a result, when the steam temperature is less than 400°C, the fluid is guided to the first low-temperature heat exchange section 231, exchanges heat in the first low-temperature heat exchange section 231, and passes from the main steam first flow path 371 to the main steam bypass. It is discharged to condenser 131 via pipe 167.

When the temperature detected by the temperature sensor 187 is 400°C or more and less than 500°C, the main steam third on-off valve 378 is opened in each flow path connected to the main steam bypass pipe 167, and the other on-off valves are opened. The main steam first on-off valve 376, the second main steam on-off valve 377, and the fourth main steam on-off valve 379 are closed. As a result, when the steam temperature is 400°C or more and less than 500°C, the fluid is guided to the first medium-temperature heat exchange section 221, and after heat exchange in the first medium-temperature heat exchange section 221, the fluid whose temperature has decreased is It flows into the first low temperature heat exchange section 231. After heat exchange in the first low-temperature heat exchange section 231, the fluid whose temperature has further decreased is discharged from the heat storage device 200 to the condenser 131 via the main steam bypass pipe 167.

When the temperature detected by the temperature sensor 187 is 500°C or higher, the main steam first on-off valve 376 is opened in each flow path connected to the main steam bypass pipe 167, and the other main steam second on-off valve is opened. The on-off valve 377, the third main steam on-off valve 378, and the fourth main steam on-off valve 379 are closed. As a result, when the steam temperature is 500°C or higher, the fluid is guided to the high temperature heat exchange section 211, and after heat exchange in the high temperature heat exchange section 211, the fluid whose temperature has decreased is transferred to the first medium temperature heat exchange section 221. After being guided and subjected to heat exchange in the first medium-temperature heat exchange section 221 , the fluid whose temperature has decreased flows into the first low-temperature heat exchange section 231 . After heat exchange in the first low-temperature heat exchange section 231, the fluid whose temperature has further decreased is discharged from the heat storage device 200 to the condenser 131 via the main steam bypass pipe 167.

Further, as shown in FIG. 19(c), when the temperature detected by the temperature sensor 185 is less than 400°C, the fourth exhaust opening/closing valve 359 is opened in each flow path connected to the boiler bleed pipe 165, The other on-off valves, the exhaust first on-off valve 356 and the second exhaust on-off valve 357, are closed. As a result, when the steam temperature is less than 400°C, the fluid is guided to the second low-temperature heat exchange section 232, where it exchanges heat, and flows from the boiler exhaust flow path 351 to the boiler bleed pipe 165. It is discharged to the condenser 131 through the .

When the temperature detected by the temperature sensor 185 is 400°C or more and less than 500°C, the first exhaust on-off valve 356 is opened in each flow path connected to the boiler bleed pipe 165, and the other on-off valve, the exhaust no. The second on-off valve 357 and the fourth exhaust on-off valve 359 are closed. As a result, when the steam temperature is 400°C or more and less than 500°C, the fluid is guided to the second medium-temperature heat exchange section 222, and after heat exchange in the second medium-temperature heat exchange section 222, the fluid whose temperature has decreased is It flows into the second low temperature heat exchange section 232. After heat exchange in the second low-temperature heat exchange section 232, the fluid whose temperature has further decreased is discharged from the heat storage device 200 to the condenser 131 via the boiler bleed pipe 165.

For example, when a period elapses between the shutdown and startup of the power plant 100, the initial steam temperature output from the boiler 110 significantly decreases from 500° C., as shown in FIG. 20. The heat storage device 202 of this modification can efficiently store heat in the heat storage layer in the optimal temperature range even in such a case.

In addition, although the power generation plant 100 and the heat storage device 200 of the first embodiment have been described as examples here, the same applies to the power generation plant 101 and the heat storage device 201 of the second embodiment. The opening and closing of each on-off valve is controlled according to the detection result of the temperature sensor 188 installed in the reheat steam bypass pipe 168, and the fluid is first guided to the heat exchange section of the heat storage layer in the temperature range corresponding to the detection result. .

<Modification 2>
[Modified example of heat storage device]
Note that, as shown in FIG. 21(a), flow paths may be provided so that the heat exchange parts in each heat storage layer are connected in series and in parallel. In addition, in FIG. 21(a), each bypass flow path of the main steam bypass flow path 372, the boiler exhaust bypass flow path 352, and the saturated water bypass flow path 312 is omitted.

In this modification, the main steam third flow path 373 allows the fluid flowing into the heat storage device 203 to pass through the first parallel medium-temperature heat exchange section 221b and the first parallel low-temperature heat exchange section 231b in this order. Discharge.

Further, the main steam fourth flow path 374 allows the fluid flowing into the heat storage device 203 to pass through the second parallel low-temperature heat exchange section 231c, and discharges the fluid from the heat storage device 203.

Further, the boiler exhaust third flow path 353 allows the fluid flowing into the heat storage device 203 to pass through the third parallel low-temperature heat exchange section 232b, and discharges the fluid from the heat storage device 203.

The opening/closing control of each on-off valve by the control device 150 according to the detected values of the temperature sensors 187 and 185 is the same as in the first modification.

<Modification 3>
[Modified example of heat storage device]
Further, as shown in FIG. 21(b), flow paths may be provided so that the heat exchange parts in each heat storage layer are connected in parallel. In addition, in FIG.21(b), each bypass flow path of the main steam bypass flow path 372, the boiler exhaust bypass flow path 352, and the saturated water bypass flow path 312 is omitted.

In this modification, the main steam third flow path 373 allows the fluid flowing into the heat storage device 204 to pass through the first parallel medium-temperature heat exchange section 221b, and discharges the fluid from the heat storage device 203.

Further, the main steam fourth flow path 374 allows the fluid flowing into the heat storage device 203 to pass through the second parallel low-temperature heat exchange section 231c, and discharges the fluid from the heat storage device 203.

Further, the boiler exhaust third flow path 353 allows the fluid flowing into the heat storage device 203 to pass through the third parallel low-temperature heat exchange section 232b, and discharges the fluid from the heat storage device 203.

The opening/closing control of each on-off valve by the control device 150 according to the detected values of the temperature sensors 187 and 185 is the same as in the first modification.

<Modification 4>
[Modified example of heat storage device]
Further, one heat exchange section of the heat storage device 205 may be provided in each heat storage layer for each inflow path. An example of the heat storage device 205 in this case is shown in FIG. 22(a).

As shown in this figure, one heat exchange section is provided in each heat storage layer for each main steam bypass pipe 167, boiler bleed pipe 165, and saturated water pipe 161, and they are connected in series and in parallel.

The opening/closing control of each on-off valve by the control device 150 according to the detected values of the temperature sensors 187 and 185 is the same as in the first modification.

<Modification 5>
[Modified example of heat storage device]
Furthermore, one heat exchange section of the heat storage device 205 may be provided in each heat storage layer, as shown in FIG. 22(b). The opening/closing control of each on-off valve according to the detected values of the temperature sensors 187 and 185 in this case is the same as in the first modification. However, in this case, the fluid discharged from the heat storage device 205 is returned to the condenser 131 via either the main steam bypass pipe 167, the boiler bleed air pipe 165, or the saturated water pipe 161, regardless of the inflow route. .

As shown in Modifications 4 and 5, by sharing the heat storage section, the same effects as other heat storage devices 200 can be obtained with a simpler configuration.

In addition, in each of the above-mentioned embodiments and each modification, the case where the heat storage device 200 includes three heat storage layers: a high temperature heat storage layer 210, a medium temperature heat storage layer 220, and a low temperature heat storage layer 230 will be described as an example. However, the number of heat storage layers is not limited to this. The number does not matter as long as there are two or more layers. Further, regarding each flow path, each heat storage layer does not necessarily need to be provided with a heat exchange section (heat storage section).

For example, when the heat storage device 200 has a two-layer configuration of a high temperature layer 210 and a medium temperature layer 220, the heat exchange section provided in the high temperature layer 210 is the first heat storage section, and the heat exchange section provided in the medium temperature layer 220 is the first heat storage section. They respectively correspond to the second heat storage section. Furthermore, when the heat storage device 200 has a three-layer configuration further including a low-temperature layer 230, a heat exchange section provided in the low-temperature layer 230 corresponds to a third heat storage section. In addition, when the heat storage device 200 has a two-layer configuration of a medium temperature layer 220 and a low temperature layer 230, the heat exchange section provided in the medium temperature layer 220 is the first heat storage section, and the heat exchange section provided in the low temperature layer 230 is the first heat storage section. Compatible with two heat storage parts.

<Modification 6>
Furthermore, in each of the embodiments described above, when the plant is stopped, the generator load of the steam turbine 120 is reduced in accordance with the reduction in the output of the boiler 110, as shown in FIG. 1(b). The time when the boiler 110 reaches the minimum load is defined as the end of equilibrium, and surplus thermal energy generated thereafter is stored. However, the operating mode and heat storage of each component when the plant is stopped is not limited to this.

For example, the reduction rate of the generator load of the steam turbine 120 may be increased more than the reduction in the output of the boiler 110. In this case, as shown in FIG. 23, the equilibrium state ends before the boiler 110 reaches its minimum load. Then, surplus thermal energy generated after the end of this equilibrium may be stored.

Thereby, the rate of decrease in the generator load of the steam turbine 120 can be controlled independently of the rate of decrease in the output of the boiler 110. That is, compared to the case where the generator load of the steam turbine 120 is reduced in accordance with the decrease in the output of the boiler 110, the rate of reduction of the generator load can be increased. Therefore, the period until the power generation plant 100 is stopped can be shortened, and the power generation plant 100 can be operated efficiently. Further, surplus thermal energy generated after the end of equilibrium can be stored in the heat storage device of any of the above embodiments and modifications in an efficient manner.

<<Third embodiment>>
Next, a third embodiment of the present invention will be described. This embodiment is an embodiment of recovering thermal energy from a heat storage device having heat storage layers in a plurality of different temperature ranges. In addition, as a heat storage device, the heat storage device (hereinafter, represented by the heat storage device 200) of each of the above-mentioned embodiments and each modification can be used. However, the heat storage device used is not limited to this. Hereinafter, this embodiment will be described using an example in which the heat storage device 200 is used.

As described above, the heat storage device 200 stores thermal energy in a plurality of temperature ranges. Therefore, when recovering heat from the heat storage device 200, it can be recovered for each temperature range and provided to the user. Here, as an example, a case will be described in which thermal energy recovered from each heat storage layer is supplied to each heat exchanger (boiler heat exchange section) in the boiler 110 and the high-pressure heater 136 at the front stage of the boiler 110 according to its design temperature. Give an example.

An example of the design temperature of each heat exchanger of the boiler 110 is shown in FIG. 24(a). Here, it is assumed that the boiler 110 includes a primary superheater 114a and a secondary superheater 114b.

As shown in this figure, the designed temperatures on the outlet side of the high-pressure heater 136 and the economizer 111 are 290°C and 340°C, respectively. Further, the design temperatures on the inlet side and outlet side of the primary superheater 114a are 430°C and 470°C, respectively.

In this embodiment, a part of the fluid supplied to the high-pressure heater 136 is heated by passing through the low-temperature layer 230, and is supplied to the outlet side of the high-pressure heater 136 or the outlet side of the economizer 111. Further, a part of the fluid supplied to the economizer 111 is heated by passing through the intermediate temperature layer 220 and is supplied to the exit side of the economizer 111 or the outlet side of the furnace water-cooled wall 112. Further, a part of the fluid supplied to the primary superheater 114a is heated by passing through the high temperature layer 210, and is supplied to the outlet side of the primary superheater 114a or the outlet side of the secondary superheater 114b.

In this case, as shown in FIG. 24(b), the inlet side of the third heat recovery pipe 430 that recovers thermal energy from the low temperature layer 230 of the heat storage device 200 is connected to the pipe on the inlet side of the high pressure heater 136. Further, the outlet side of the third heat recovery pipe 430 is branched into two, and is connected to the outlet side piping of the high pressure heater 136 and the outlet side of the energy saver 111, respectively. The third heat recovery pipe 430 after branching is provided with heat recovery on/off valves 433 and 434, respectively. After heat recovery from the low temperature layer 230, these heat recovery on/off valves 433 and 434 are controlled to open and close by the control device 150 depending on the operating state (fluid temperature, etc.). Specifically, the third heat recovery pipe 430 is provided with a temperature sensor that detects the temperature of the fluid on the outlet side thereof. The control device 150 obtains the fluid temperature after heat recovery from the low temperature layer 230 based on the detected value of the temperature sensor. Then, opening and closing are controlled so that the fluid is returned to the boiler heat exchange section having a design temperature higher than the obtained fluid temperature.

The inlet side of the second heat recovery pipe 420 that recovers thermal energy from the intermediate temperature layer 220 of the heat storage device 200 is connected to the pipe on the inlet side of the energy saver 111. Further, the outlet side of the second heat recovery pipe 420 is branched into two, and is connected to the outlet side piping of the energy saver 111 and the outlet side piping of the furnace water cooling wall 112, respectively. The second heat recovery pipe 420 after branching is provided with heat recovery on/off valves 423 and 424, respectively. After heat is recovered from the intermediate temperature layer 220, these heat recovery on/off valves 423 and 424 are controlled to open and close by the control device 150 depending on the operating state (fluid temperature, etc.). Specifically, the second heat recovery pipe 420 is provided with a temperature sensor that detects the temperature of the fluid on the outlet side thereof. The control device 150 obtains the fluid temperature after heat recovery from the intermediate temperature layer 220 based on the detected value of the temperature sensor. The obtained control device 150 then controls opening and closing so that the fluid is returned to the boiler heat exchange section having a design temperature higher than the fluid temperature.

The inlet side of the first heat recovery pipe 410 that recovers thermal energy from the high temperature layer 210 of the heat storage device 200 is connected to the pipe on the inlet side of the primary superheater 114a. The outlet side of the first heat recovery pipe 410 branches into two, and is connected to the outlet side piping of the primary superheater 114a and the outlet side piping of the secondary superheater 114b, respectively. The first heat recovery pipe 410 after branching is provided with heat recovery on/off valves 413 and 414, respectively. After heat is recovered from the high temperature layer 210, these heat recovery on/off valves 413 and 414 are controlled to open and close by the control device 150 depending on the operating state (fluid temperature, etc.). Specifically, the first heat recovery pipe 410 is provided with a temperature sensor that detects the temperature of the fluid on the outlet side thereof. The control device 150 obtains the fluid temperature after heat recovery from the high temperature layer 210 based on the detected value of the temperature sensor. The obtained control device 150 then controls opening and closing so that the fluid is returned to the boiler heat exchange section having a design temperature higher than the fluid temperature.

The fluid passing through the third heat recovery pipe 430 passes through the first low-temperature heat exchange section 231, the second low-temperature heat exchange section 232, and the third low-temperature heat exchange section 233 of the low-temperature layer 230, and loses heat in these heat exchange sections. Collect. As a result, a fluid having a temperature in the temperature range of the low temperature layer 230 is generated. Further, the fluid passing through the second heat recovery pipe 420 passes through the first intermediate temperature heat exchange section 221 and the second intermediate temperature heat exchange section 222 of the intermediate temperature layer 220, and recovers heat in these heat exchange sections. As a result, a fluid having a temperature in the temperature range of the intermediate temperature layer 220 is generated. The fluid passing through the first heat recovery pipe 410 passes through the high temperature heat exchange section 211 and recovers heat. As a result, a fluid having a temperature in the temperature range of the high temperature layer 210 is generated.

As described above, during heat recovery, the control device 150 controls the first heat recovery on-off valve 411, the second heat recovery on-off valve 421, and the third heat recovery on-off valve 431 to open states. Power generation plants 100 and 101 are equipped with temperature sensors that detect the temperature of each heat storage layer. The control device 150 monitors the temperature of each heat storage layer detected by these temperature sensors, and determines that heat recovery is complete when the temperature becomes lower than a predetermined set temperature of each heat storage layer. When determining that heat recovery is complete, the control device 150 controls these heat recovery on/off valves 411, 421, and 431 to close, respectively.

Further, during heat recovery, the control device 150 opens the main steam on-off valve 172 and the reheat steam on-off valve 174 in the power plant 100 of the first embodiment. Further, the boiler startup bleed air adjustment valve 175 and the main steam bypass on-off valve 177 are closed. Furthermore, in the power plant 101 of the second embodiment, the reheat steam bypass on-off valve 178 and the high-pressure steam turbine bypass on-off valve 179 are further closed.

As explained above, according to the heat storage device 200 of the present embodiment, thermal energy at a plurality of different temperatures depending on the melting point can be separately and independently recovered in each heat storage layer during heat recovery. The recovered thermal energy at different temperatures can then be provided to users depending on the required temperature. That is, according to the heat storage device 200 of this embodiment, it is possible to realize the use of heat depending on the purpose.

Furthermore, in the power generation plant 100 including the heat storage device 200 of this embodiment, surplus thermal energy is stored in the heat storage device 200 independently for each temperature zone. Therefore, when heat is recovered from the heat storage device 200, surplus thermal energy can be efficiently utilized by recovering heat from the heat storage layer in which thermal energy is stored according to the temperature required by the boiler heat exchange section to be used.

For example, as shown in FIG. 25(a) as "release of thermal energy," by using this surplus thermal energy at startup, it is possible to provide optimal thermal energy to each heat exchanger of the boiler 110. , can be started up quickly.

Moreover, the power generation plant 100 may be operated not only at the time of startup but also, for example, while recovering surplus thermal energy stored in the heat storage device 200 during normal operation.

For example, as shown in FIG. 25(b), the load on the boiler 110 is reduced while keeping the output of the steam turbine 120 constant (boiler heat output suppression). Further, as shown in the figure, the load on the steam turbine 120 is increased while keeping the load on the boiler 110 constant (steam turbine drive promotion). By utilizing the surplus thermal energy stored in the heat storage device 200 in this manner, the fuel used for combustion in the boiler 110 can be saved.

Further, as shown in FIG. 26, in the pumped storage operation mode, when the power generation plant 100 is stopped, the rate of decrease in the generator load of the steam turbine 120 is set to be equal to or higher than the rate of decrease in the output of the boiler 110, as described above. The surplus thermal energy is stored in the heat storage device 200. Further, during the period when the steam turbine 120 is stopped, surplus thermal energy generated by the boiler 110 is stored in the heat storage device 200. Then, at the time of startup, these surplus thermal energies stored in the heat storage device 200 may be recovered. This increases startup efficiency.

In the pumping operation mode, by utilizing the heat storage device 200 in this way, not only can thermal energy be used efficiently, but also the period required for stopping and starting can be shortened. Thereby, a smooth transition from the normal operation mode to the pumping operation mode and a smooth return from the pumping operation mode to the normal operation mode can be realized.

For example, by using the heat storage device 200 of this embodiment for starting and stopping a steam power generation plant in DSS (Daily Start & Stop), it is possible to shorten the starting and stopping time. Further, by using the heat storage device 200 of this embodiment, even when the steam power generation plant and the renewable energy power generation plant are used together, fluctuations in the amount of power supplied due to renewable energy can be leveled out in total. This reduces the number of times that the overall power supply exceeds the grid requirements.

Furthermore, according to the present embodiment, the thermal energy stored in the thermal storage device 200 can be utilized not only during normal startup, but also when the system is restored after FCB or when the load of the power generation plant 100 rapidly increases. This makes it possible to shorten the system recovery time and load rise time.

Note that the rapid load increase is, for example, a case where a faster load change is required than during startup/load change/stop during normal operation. For example, when the system requests a higher load increase than normal startup, such as when the system returns after becoming unstable. For example, in the case of the boiler 110, the rate of increase is 5%/min or more, and in the case of the gas turbine, the rate of increase is 10 to 20%/min or more.

In addition, there may be cases where the rate of load change exceeds a limit that corresponds to changes in heat amount of equipment that constitutes the power generation plant 100 other than the steam turbine 120, or there is a load change that prevents the boiler 110 from responding to the demands of the system. This also includes cases where it is requested.

Note that depending on the temperature range of each heat storage layer, the connection of each heat recovery pipe (first heat recovery pipe 410, second heat recovery pipe 420, and third heat recovery pipe 430) is not limited to the above-mentioned piping. For example, regarding each boiler heat exchange section included in the water supply line 130 and the boiler 110, a heat recovery pipe that passes through a heat storage layer in a temperature range higher than and closest to the inlet side temperature of the boiler heat exchange section branches from the inlet side piping, and The heat recovery pipe that has passed through the heat storage layer with a temperature lower than the side temperature and in the closest temperature range may be connected to the outlet side pipe.

For example, the boiler 110 has a first boiler heat exchange section that generates a fluid having a temperature in a first temperature range through heat exchange, and a fluid that has a temperature in a second temperature range that is lower than the first temperature range through heat exchange. The heat storage device 200 includes a second boiler heat exchange section (or high pressure heater 136 of the water supply line 130) that generates fluid, and a first heat storage section (high temperature layer) that stores thermal energy in the first temperature range. 210) and a second heat storage section (heat exchange section in the intermediate temperature layer 220) that stores heat energy in the second temperature range, the second heat recovery pipe 420 is connected to the second boiler. A part of the fluid generated in the heat exchange section is guided to the second heat storage section, and after recovering thermal energy in the second heat storage section, the fluid is transferred to the first boiler heat exchange section or the first boiler heat exchange section or higher in the boiler 110. It leads to the boiler heat exchange section which has the design temperature. In addition, the first heat recovery pipe 410 is connected to a boiler heat exchange section (for example, a first boiler heat exchange section or a boiler having a design temperature equal to or higher than the first boiler heat exchange section) into which the fluid guided by the second heat recovery tube 420 flows. A part of the fluid generated in the heat exchange section) is guided to the first heat storage section, and after recovering thermal energy in the first heat storage section, it is guided to the outlet side of the boiler heat exchange section.

<Modification 7>
[Variation example during heat recovery]
In the power generation plants 100 and 101 (hereinafter referred to as the power generation plant 100) of the above embodiment, thermal energy stored in the heat storage devices 200 to 206 (hereinafter referred to as the heat storage device 200) is stored in each heat storage layer. By supplying energy to the heat exchanger of the boiler 110 corresponding to the temperature range of the heat storage layer, energy supply is efficiently supported when the load of the boiler 110 increases.

However, the method of recovering heat from the heat storage device 200 is not limited to this. For example, as shown in FIG. 27, the fluid may be passed layer by layer in order from the low temperature layer 230, and after recovering the entire thermal energy stored in the heat storage device 200, it may be returned to the system of the power generation plant 100.

The return destination of the fluid after thermal energy recovery is, for example, the main steam pipe 162. Further, the fluid to the heat storage device 200 is supplied from the water supply line 130, for example. In this case, for example, a fourth heat recovery pipe 440 connecting the water supply line 130 and the main steam pipe 162 is provided, and the heat storage device 200 is arranged on the fourth heat recovery pipe 440.

By piping in this way, water input into the heat storage device 200 is heated in the order of the low temperature layer 230, the intermediate temperature layer 220, and the high temperature layer 210. As a result, high-temperature, high-pressure steam is generated only within the heat storage device 200, and can be directly input into the high-pressure steam turbine 121.

In addition, in this modification, during high-load operation, the low temperature reheat steam pipe 163 may be the destination for the return of the fluid after thermal energy recovery in the heat storage device 200.

<<Fourth embodiment>>
Next, a fourth embodiment of the present invention will be described. In this embodiment, unlike the first to third embodiments described above, surplus power is stored in a heat storage device. Surplus power is generated when a power generation device using renewable energy (hereinafter referred to as renewable energy) such as wind and solar power is incorporated into the power grid.

These types of renewable energy power generation depend on natural phenomena such as weather, and the amount of power generated fluctuates rapidly. When renewable energy power generation is incorporated into a thermal power generation power grid, fluctuations in the power generation amount due to renewable energy power generation are absorbed by adjusting the power generation amount of the thermal power plant in order to maintain the stability of the power system. Therefore, when the amount of power supplied by renewable energy power generation increases, a power supply command is issued to the thermal power plant to suppress the amount of power generation. However, a minimum operational load (for example, 30%, etc.) is set for thermal power plants. In a thermal power plant, even if an instruction is given to generate an amount of power below the minimum load, the thermal power plant may not be able to comply with the instruction, and a surplus may occur in the amount of power generated. In this embodiment, this surplus power is stored as heat.

There are systems that store electrical energy as thermal energy and release it as needed. For example, JP 2016-142272A (cited document 2) states that "an electrical energy storage and release system for storing electrical energy as thermal energy includes a heat pump cycle including a first working fluid and a second working fluid. a first heat storage system including a first thermal fluid, a second thermal storage system including a second thermal fluid, an electric heater, and a power conditioning device, the first thermal storage system including a first thermal fluid, the second thermal storage system including a second thermal fluid, and a power conditioning device fluidly connected to each other. The first thermal storage system includes a fluidically connected first low temperature thermal storage tank and a high temperature thermal storage tank, and the second thermal storage system includes a fluidically connected second low temperature thermal storage tank and a high temperature thermal storage tank. and an electric heater operatively connected between the thermal storage tanks. A power conditioning device regulates a portion of the excess electrical energy of the power source to supply the electric heater and the heat pump cycle. )” technology has been disclosed.

However, since the technology disclosed in Cited Document 2 does not assume renewable energy power generation integrated into the power grid, it is possible to store surplus power in the power grid or use the stored thermal energy to There is no mention of using it when the load increases.

In the fourth embodiment of the present invention, surplus power generated when the amount of power generation according to the power supply command falls below the minimum load of the power generation plant 100 is stored in a heat storage device. Then, as in the other embodiments described above, the stored heat is recovered from the optimum temperature range at an appropriate timing during operation of the power generation plant and utilized.

The fluid system of the power plant 100 of this embodiment basically has the same configuration as the first embodiment. However, as shown in FIG. 28, the heat storage device 207 of this embodiment stores surplus power of the power generated by the renewable energy power generation device 600 or the generator 109. Therefore, a power supply line is provided for feeding surplus power generated by power generation by the generator 109 or the renewable energy power generation device 600 to the heat storage device 207. In addition, in this embodiment, the saturated water pipe 161, the boiler bleed air pipe 165, the main steam bypass pipe 167, the boiler startup bleed air adjustment valve 175, and the main steam bypass on-off valve 177 may not be provided.

[Heat storage device]
FIG. 29(a) shows an example of the heat storage device 207 of this embodiment. The heat storage device 207 of this embodiment stores surplus power generated by the power generation plant 100 and the renewable energy power generation device 600 as surplus thermal energy in accordance with instructions from the control device 150.

The heat storage device 207 includes a plurality of heat storage layers made of heat storage materials each having temperature characteristics (melting points) in different temperature ranges, and a heat exchange section provided in each heat storage layer.

Hereinafter, in this embodiment, similarly to the first embodiment, the heat storage device 207 includes a high temperature heat storage layer 210 (high temperature layer 210), a medium temperature heat storage layer 220 (medium temperature layer 220), and a low temperature heat storage layer 230 as heat storage layers. (Low temperature layer 230) and the case where three heat storage layers are provided will be described as an example.

Note that, similarly to the first embodiment, the high temperature layer 210 is a heat storage layer made of a heat storage material having temperature characteristics (melting point) in a temperature range centered around 500° C. (first temperature range). The intermediate temperature layer 220 is a heat storage layer made of a heat storage material having temperature characteristics in a temperature range centered around 400° C. (second temperature range). Furthermore, the low temperature layer 230 is a heat storage layer made of a heat storage material having temperature characteristics in a temperature range centered around 300° C. (third temperature range).

Further, the heat storage device 207 of this embodiment uses an electric heater 510 that heats an object by passing a current through a resistor to generate heat, as shown in FIG. 29(a), as a heat exchange unit. The electric heaters 510 include a high temperature layer electric heater 511 placed in the high temperature layer 210, a medium temperature layer electric heater 521 placed in the medium temperature layer 220, and a low temperature layer electric heater 511 placed in the low temperature layer 230. 531. Note that it may be a device that heats an object by induction heating by passing a current through a coil. The electric heater 510 may be any device as long as it can heat an object using electric power.

The electric heater 511 for the high temperature layer, the electric heater 521 for the medium temperature layer, and the electric heater 531 for the low temperature layer use the surplus power supplied by the power supply lines 512, 522, and 532, respectively, to each heat storage layer (the high temperature layer 210, The medium temperature layer 220 and the low temperature layer 230) are heated.

The heat storage material used for each heat storage layer is basically the same as in the first embodiment. For example, a latent heat storage material that utilizes the latent heat of phase transformation of a substance can be used. The temperature characteristics of the heat storage layer are characteristics determined based on the melting temperature (melting point) of this latent heat storage material. Further, the heat storage material used for each heat storage layer may be an alloy material having a heat storage temperature (melting point) exceeding 500°C. Furthermore, a structure in which this alloy material is included in ceramics or metal may be used. For example, latent heat storage microcapsules disclosed in International Publication No. 2017/200021 can be used.

Further, the heat storage material may be a molten salt in which salt (solid) is in a molten state (liquid). Molten salt can store a large amount of heat when heated to high temperatures. As the molten salt, for example, a mixture of potassium nitrate and sodium nitrate can be used. However, it is not limited to this. It can be selected as appropriate depending on the required heat storage capacity, temperature, etc.

Note that, as in the first embodiment, inside the heat storage device 207, as a flow path used during heat recovery, there is also a flow path (first heat recovery pipe 410 and second heat recovery pipe 410) that connects the heat exchange parts in the same heat storage layer. A pipe 420 and a third heat recovery pipe 430) are provided therein.

The first heat recovery pipe 410, the second heat recovery pipe 420, and the third heat recovery pipe 430 each have a first heat recovery on-off valve 411 and a second heat recovery on-off valve 421 on the inlet side of each heat storage layer. , and a third heat recovery on/off valve 431 are provided. The opening and closing of these heat recovery on-off valves 411, 421, and 431 is controlled by the control device 150. During heat recovery, the control device 150 controls the opening and closing of these heat recovery on/off valves 411, 421, and 431 so that heat can be recovered from the heat storage layer in the optimal temperature range.

[ON/OFF control of electric heater by control device]
In general, a power generation plant generates electricity in response to a power dispatch command received from a power dispatch center or the like that monitors the power system under its jurisdiction. The power dispatch control center sends and controls power supply orders to each power generation plant so that the total power generation amount of all the power plants under its jurisdiction is equal to the amount of electricity used (demand amount).

Hereinafter, assuming that solar power generation is used as renewable energy power generation and the amount of electricity demanded is constant, ON/OFF control of the electric heater 510 will be explained using FIGS. 30(a) to 30(c).

In solar power generation, the amount of power supplied changes significantly depending on events such as sunrise and sunset, as shown in FIG. 30(b). Here, time TA is sunrise and time TD is sunset. The amount of power supplied by solar power generation is initially 0, but starts to increase from time TA and reaches the maximum value. Then, after maintaining the maximum value for a predetermined period, it starts to decrease and reaches the minimum (0) at time TD.

In response to such changes in the amount of power supplied by solar power generation, a power supply command is issued to the thermal power plant so that the amount of power supplied from the power grid matches the amount of demand. A dotted line in FIG. 30(a) shows the temporal change in the amount of power generated due to the power supply command. A power supply command is issued to the power generation plant 100 to reduce the amount of power generated until the amount of power supplied by solar power generation reaches the maximum. After that, the amount of power generated by solar power generation begins to decline, and a power supply order is issued to increase the amount of power generated.

FIG. 30(a) shows the turbine generator load of the power generation plant 100 that changes according to this power supply command. In the power generation plant 100, when the load on the boiler according to the amount of power generated by the power supply command reaches the minimum load, the load on the turbine generator cannot be reduced any further. Therefore, surplus power is generated at this timing.

As shown in FIG. 30(c), the control device 150 monitors the power supply command and the corresponding load of the boiler generator, and when the power supply command falls below the minimum load of the boiler generator, the control device 150 switches the electric heater 510 to the power supply command. Outputs ON command. Further, when the power supply command becomes equal to or higher than the minimum load of the boiler generator, an OFF command is output to the electric heater 510.

That is, at time TA (for example, at sunrise), the amount of power supplied from renewable energy power generation increases and the power supply command for thermal power starts to be suppressed in order to accept renewable energy. Then, at time TB, the power supply command falls below the minimum load. However, in the thermal power generation plant 100, the minimum load is determined in advance for each plant. Therefore, even if a power supply command below this minimum load is received, the load cannot be lowered any further. That is, since the power generation plant 100 continues to operate at the lowest load, the amount of power supplied due to operation at the lowest load exceeds the amount of power supplied according to the power supply command in the power grid, resulting in surplus power.

At this point (time TB), electric heater 510 is turned on to store surplus power in heat storage device 207 . Thereafter, the electric heater 510 is turned off at the time when the amount of renewable energy supplied starts to decrease and no surplus power is generated, in other words, at the time when the power supply command to the thermal power generation plant 100 reaches the minimum load (time TC). be done.

Note that each time the control device 150 receives a power supply command, it compares the received power supply command with the minimum load of the power generation plant 100, and if the amount of power supplied according to the power supply command is less than the minimum load, it turns on the electric heater 510. Output the command. On the other hand, when the amount of power supplied according to the power supply command exceeds the minimum load, an OFF command is output to the electric heater 510.

When an ON command is received, heat storage by the electric heater 510 is started, and when an OFF command is received, heat storage by the electric heater 510 is stopped.

In addition, in this embodiment, the electric heater 511 for the high temperature layer and the electric heater 521 for the medium temperature layer are used.
and the electric heater 531 for the low temperature layer, respectively, the high temperature layer 210, the medium temperature layer 220, and the low temperature layer
Heat 30 minutes. For this reason, the control device 150 may also monitor the temperature of each heat storage layer, and control the electric heater 510 to be turned off when the melting point of the heat storage layer is reached. for example,
When the temperature of the low temperature layer 230 reaches 300° C., the electric heater 531 for the low temperature layer is turned off, and when the temperature of the medium temperature layer 220 reaches 400° C., the electric heater 521 for the medium temperature layer is turned off.

[Heat recovery]
The connections during heat recovery are shown in FIG. 31(a). Since the connection of each heat recovery tube is the same as in the first embodiment, the explanation will be omitted here. The same applies to the opening/closing control of the heat recovery on/off valve.

As explained above, the power generation plant 100 of the present embodiment includes a boiler 110 that heats supplied water to generate superheated steam, and is rotationally driven by the superheated steam superheated in the boiler 110 to drive the generator 109. A steam turbine 120, a heat storage device 207 that collects surplus energy passing through the interior and stores it, and a control device 150 that controls the surplus energy generated during operation, including when starting and stopping, to be stored in the heat storage device 207. and.

The surplus energy includes surplus power energy that is surplus power energy, and the heat storage device 207 has a plurality of heat storage sections (a high temperature layer 210, a medium temperature layer 220, low temperature layer 230) is equipped with an electric heater 510 that is heated by surplus electric energy, and when the control device 150 receives a power supply command that is lower than a predetermined load (for example, minimum load) of the power generation plant 100, the control device 150 Activate heater 510.

In this way, in this embodiment, surplus electric energy is stored. When surplus heat (steam) is stored as surplus energy, the heat storage layer that supplies the surplus heat may be limited because the heat storage material cannot store heat at a temperature higher than that of the steam. However, when storing surplus power as surplus energy, the heat is stored by supplying the power to the electric heater 510, so as long as there is surplus power energy, the temperature can be increased without any restriction. can be selected arbitrarily. Therefore, according to the present embodiment, surplus power energy generated in the power generation plant 100 can be stored in a manner that can be used efficiently.

Further, according to the heat storage device 207 of the present embodiment, thermal energy at a plurality of different temperatures depending on the melting point can be separately and independently recovered in each heat storage layer during heat recovery. The recovered thermal energy at different temperatures can then be provided to users depending on the required temperature. That is, according to the heat storage device 207 of this embodiment, it is possible to realize the use of heat depending on the purpose.

Furthermore, in the power generation plant 100 including the heat storage device 207 of this embodiment, surplus thermal energy is stored in the heat storage device 207 independently for each temperature zone. Therefore, when heat is recovered from the heat storage device 200, surplus thermal energy can be efficiently utilized by recovering heat from the heat storage layer in which thermal energy is stored according to the temperature required by the boiler heat exchange section to be used.

<Modification 8>
In the embodiment described above, the heat storage device 207 includes a plurality of heat storage layers made of heat storage materials each having temperature characteristics in different temperature ranges, and stores heat only up to the temperature range. However, heat storage in the heat storage device 207 is not limited to this.

For example, like a heat storage device 207a shown in FIG. 29(b), all the devices may be configured to be able to store heat up to the same temperature, and may be configured to store heat up to that temperature. Here, as an example, a case will be exemplified in which heat is stored in all the heat storage layers up to a temperature corresponding to the high temperature layer 210 of the above embodiment.

FIG. 31(b) shows connections during heat recovery when the heat storage device 207a is used. In this modification, the inlet side of each heat recovery pipe (first heat recovery pipe 410, second heat recovery pipe 420, and third heat recovery pipe 430) is connected to the pipe on the inlet side of the primary superheater 114a. . A heat recovery on/off valve 411 is provided between the primary superheater 114a and each heat recovery pipe. Further, the outlet side is branched into two, and is connected to the outlet side piping of the primary superheater 114a and the outlet side piping of the secondary superheater 114b, respectively. The first heat recovery pipe 410 after branching is provided with heat recovery on/off valves 413 and 414, respectively. Control of each heat recovery on/off valve is the same as in the third embodiment.

In the case of this modification, in order to store heat in all the heat storage layers up to a temperature corresponding to the high temperature layer 210, the temperature of each heat storage layer is monitored and the electric heater of each heat storage layer is controlled to turn off, as in the above embodiment. There's no need.

According to this modification, surplus electric energy can be efficiently stored as thermal energy with a simple configuration.

Note that in this modification, the number of heat storage layers of the heat storage device 207 does not matter. For example, the heat storage device 207b shown in FIG. 32 may be a single layer.

<<Fifth embodiment>>
Next, a fifth embodiment of the present invention will be described. In this embodiment, surplus electrical energy and surplus thermal energy are stored in the heat storage device as surplus energy.

Similar to the first embodiment, surplus thermal energy is steam generated by the boiler 110 that is generated when the power generation plant 100 is started or stopped, and is thermal energy that is not used by the steam turbine 120. Further, the surplus power energy is the power generated when the power supply command value falls below the minimum load of the power generation plant 100, as in the fourth embodiment.

A fluid system diagram of the power plant 100 of this embodiment is shown in FIG. 33. The fluid system of this embodiment basically has the same configuration as the first embodiment. In this embodiment, in order to store surplus power energy in the heat storage device 208, a power supply line is further provided to feed the surplus power energy generated by power generation by the generator 109 or the renewable energy power generation device 600 to the heat storage device 208. .

[Heat storage device]
FIG. 34 shows an example of the heat storage device 208 of this embodiment. An example of the heat storage device 208 of this embodiment is shown. Similar to the first embodiment, the heat storage device 208 of this embodiment stores the surplus power energy generated by the power generation plant 100 and the renewable energy power generation device 600 as surplus thermal energy in accordance with instructions from the control device 150.

The heat storage device 208 of this embodiment has the same configuration as the heat storage device 200 of the first embodiment shown in FIG. Furthermore, the heat storage device 208 of this embodiment includes the electric heater 510 described in the fourth embodiment as a heat exchange section. Similar to the fourth embodiment, the electric heater 510 includes a high temperature layer electric heater 511 placed in the high temperature layer 210, a medium temperature layer electric heater 521 placed in the medium temperature layer 220, and a low temperature layer 230. It has an electric heater 531 for the low temperature layer. Further, power supply lines 512, 522, and 532 are provided for supplying surplus power to the electric heater 511 for the high temperature layer, the electric heater 521 for the middle temperature layer, and the electric heater 531 for the low temperature layer, respectively.

The heat storage material used for each heat storage layer is the same as in the fourth embodiment.

Further, the control device 150 of this embodiment controls the on-off valve and the electric heater 510.
N/OFF control is performed independently, and is the same as in the first embodiment and the fourth embodiment. In this embodiment as well, the control device 150 may also monitor the temperature of each heat storage layer and control the electric heater 510 to be turned off when the temperature reaches the melting point of the heat storage layer.

[Heat recovery]
FIG. 35 shows connections during heat recovery in this embodiment. Heat recovery depends on the temperature characteristics of the heat storage layer. Therefore, since the connection of each heat recovery tube is the same as in the first embodiment, the explanation will be omitted here. The same applies to the opening/closing control of the heat recovery on/off valve.

As explained above, the power generation plant 100 of the present embodiment includes a boiler 110 that heats supplied water to generate superheated steam, and is rotationally driven by the superheated steam superheated in the boiler 110 to drive the generator 109. A steam turbine 120, a heat storage device 208 that collects and stores surplus energy passing through the turbine, and a control device 150 that controls the surplus energy generated during operation, including when starting and stopping, to be stored in the heat storage device 208. and.

The surplus energy includes surplus thermal energy that is surplus thermal energy of the superheated steam generated by the boiler 110, and the heat storage device 208 recovers heat from the fluid passing through the flow path provided inside. A plurality of heat storage sections each having temperature characteristics in different temperature ranges (high temperature layer 210, medium temperature layer 220, low temperature layer 230) store heat, and operate according to instructions from the control device 150 to allow fluid to flow into the flow path. The control device 150 is configured such that surplus thermal energy generated during at least one of startup and shutdown has temperature characteristics in a temperature range to which the temperature of the surplus thermal energy belongs, in the form of a fluid. The opening and closing of the on-off valve is controlled so that the flow passes through the heat storage section first. Further, the surplus energy further includes surplus power energy that is surplus power energy, and each heat storage section is provided with an electric heater 510 that is heated by the surplus power energy, and the control device 150 controls When receiving a power supply command lower than the specified load (for example, minimum load), the electric heater 510 is activated.

Therefore, according to the present embodiment, surplus thermal energy and surplus electric energy generated in the power generation plant 100 can be stored in a manner that can be used efficiently. That is, the same effects as the first embodiment and the fourth embodiment can be obtained.

Although the heat storage device 200 of the first embodiment has been described here as an example of a configuration for storing surplus thermal energy, the present invention is not limited to this. For example, the heat storage device 201 of the second embodiment or the heat storage devices 200, 201, 202, 203, 204, and 205 of other modified examples may be used.

<Modification 9>
Moreover, like the heat storage device 208a shown in FIG. 36, like the fourth embodiment, all the devices may be configured to be able to store heat up to the same temperature, and may be configured to store heat up to that temperature. Here, as an example, a case will be exemplified in which heat is stored in all the heat storage layers up to a temperature corresponding to the high temperature layer 210 of the above embodiment.

On the other hand, since heat is stored in all the heat storage layers up to a temperature corresponding to the high temperature layer 210, in this modification, the control device 150 does not need to monitor the temperature of each heat storage layer and turn off the electric heater 510. .

[Heat recovery]
FIG. 37(a) shows connections during heat recovery when the heat storage device 208a is used. As described above, the control of the piping and heat recovery on/off valve during heat recovery depends on the temperature characteristics of the heat storage layer. Therefore, this case is similar to FIG. 31(b) of the fourth embodiment.

According to this modification, surplus electric energy and surplus thermal energy can be efficiently stored as thermal energy with a simple configuration.

In addition, when storing surplus thermal energy, a heat storage material corresponding to the temperature of the steam is arranged in each layer, and heat is stored/radiated in a phase change region (latent heat region, constant temperature). When surplus power energy is stored in the electric heater 510, the heat storage material can be heated up to the upper limit temperature of the electric heater 510, so that heat can be stored up to a temperature higher than the phase change region. In this case, heat is stored in the sensible heat region.

<Modification 10>
In addition, although the said modification illustrated the case where heat is stored in all the heat storage layers to the temperature corresponded to the high temperature layer 210, the heat storage temperature in each heat storage layer is not limited to this. The combination of heat storage temperatures is arbitrary. Furthermore, the number of heat storage layers is not limited.

For example, heat may be stored in the top two layers to a temperature corresponding to the high temperature layer 210, and heat may be stored in the bottom layer to a temperature corresponding to the medium temperature layer 220. Alternatively, heat may be stored in the uppermost layer to a temperature corresponding to the high temperature layer, and heat may be stored in the lower two layers to a temperature corresponding to the intermediate temperature layer 220. In this case, for heat radiation (heat recovery), the first heat recovery pipe 410 is also connected to the medium temperature layer 220 and the low temperature layer 230, and the second heat recovery pipe 420 is also connected to the low temperature layer 230, so that each line Install a valve in the By opening and closing these valves, it is possible to radiate heat according to the situation during heat storage.

Further, the heat storage device 200 that stores surplus thermal energy and the heat storage device 207 that stores surplus electric energy may be provided separately, as shown in FIG. 38. In this case, the arrangement position of the heat storage device 207 that stores surplus power energy can be freely set. In particular, the heat storage device 207 that stores surplus power energy may be placed at an arbitrary position for each heat storage layer. Furthermore, a heat storage device 208 that stores surplus power energy and surplus thermal energy can also be arranged in combination with at least one of these heat storage devices 200 and 207 as appropriate. Note that the heat storage device 200 may be the heat storage device 201 of the second embodiment or the heat storage devices 200, 201, 202, 203, 204, and 205 of other modifications as described above. Further, the heat storage device 207 may be heat storage devices 207a and 207b. Furthermore, the heat storage device 208 may be a heat storage device 208a. Furthermore, the number of heat storage layers in each heat storage device is not limited.

Note that the present invention is not limited to the above-described embodiments and modified examples, and various changes can be made according to the design etc. as long as they do not deviate from the technical idea of the present invention. For example, the flow channels and power supply lines used during heat storage in the heat storage devices 200 to 208a, and the flow channels used during heat recovery may not necessarily all be provided.

100: Power generation plant, 101: Power generation plant, 109: Generator,
110: Boiler, 111: Economizer, 112: Furnace water cooling wall, 113: Brackish water separator, 114: Superheater, 114a: Primary superheater, 114b: Secondary superheater, 115: Reheater,
120: steam turbine, 121: high pressure steam turbine, 122: intermediate pressure steam turbine, 123: low pressure steam turbine,
130: Water supply line, 131: Condenser, 132: Condensate pump, 133: Low pressure heater, 134: Deaerator, 135: Water supply pump, 136: High pressure heater,
150: control device, 151: control console,
161: Saturated water pipe, 162: Main steam pipe, 163: Low temperature reheat steam pipe, 164: High temperature reheat steam pipe, 165: Boiler extraction pipe, 166: Turbine exhaust pipe, 167: Main steam bypass pipe, 168: Reheat Steam bypass pipe, 169: high pressure steam turbine bypass pipe,
172: Main steam on-off valve, 174: Reheat steam on-off valve, 175: Boiler start extraction air adjustment valve, 177: Main steam bypass on-off valve, 178: Reheat steam bypass on-off valve, 179: High pressure steam turbine bypass on-off valve,
181: temperature sensor, 185: temperature sensor, 187: temperature sensor, 188: temperature sensor,
200: Heat storage device, 201: Heat storage device, 202: Heat storage device, 203: Heat storage device, 204: Heat storage device, 205: Heat storage device, 206: Heat storage device,
210: high temperature heat storage layer (high temperature layer), 211: high temperature heat exchange section, 214: reheat high temperature heat exchange section,
220: medium temperature heat storage layer (medium temperature layer), 221: first medium temperature heat exchange section, 221b: first parallel medium temperature heat exchange section, 222: second medium temperature heat exchange section, 224: reheat medium temperature heat exchange section,
230: Low temperature heat storage layer (low temperature layer), 231: First low temperature heat exchange section, 231b: First parallel low temperature heat exchange section, 231c: Second parallel low temperature heat exchange section, 232: Second low temperature heat exchange section, 232b: Third parallel low temperature heat exchange section, 233: Third low temperature heat exchange section, 234: Reheat low temperature heat exchange section,
301: Branch point, 302: Confluence point, 303: Branch point, 304: Confluence point, 305: Branch point, 306: Confluence point, 307: Branch point, 308: Confluence point,
311: Saturated water flow path, 312: Saturated water bypass flow path, 316: Saturated water first on-off valve, 317: Saturated water third on-off valve,
351: Boiler exhaust flow path, 352: Boiler exhaust bypass flow path, 353: Boiler exhaust third flow path, 354: Boiler exhaust fourth flow path, 356: Exhaust first on-off valve, 357: Exhaust second on-off valve, 359 : Exhaust fourth on-off valve,
371: Main steam first flow path, 372: Main steam bypass flow path, 373: Main steam third flow path, 374: Main steam fourth flow path, 376: Main steam first opening/closing valve, 377: Main steam second opening/closing Valve, 378: Main steam third on-off valve, 379: Main steam fourth on-off valve,
381: Reheat steam first flow path, 382: Reheat steam bypass flow path, 383: Reheat steam third flow path, 386: Reheat steam first on-off valve, 387: Reheat steam second on-off valve, 388: Reheat steam third on-off valve,
410: First heat recovery pipe, 411: First heat recovery on/off valve, 413: Heat recovery on/off valve, 414: Heat recovery on/off valve, 420: Second heat recovery pipe, 421: Second heat recovery on/off valve, 423: Heat recovery on/off valve, 424: Heat recovery on/off valve, 430: Third heat recovery pipe, 431: Third heat recovery on/off valve, 433: Heat recovery on/off valve, 434: Heat recovery on/off valve, 440: Fourth heat recovery pipe 207: Heat storage device, 207a: Heat storage device, 207b: Heat storage device, 208: Heat storage device, 208a: Heat storage device, 510: Electric heater, 511: Electric heater for high temperature layer, 512: Power supply line, 521: Electric heater for medium temperature layer , 522: Power supply line, 531: Electric heater for low temperature layer, 532: Power supply line, 600: Renewable energy power generation device

Claims (22)

a boiler that heats supplied water to generate superheated steam;
a steam turbine that is rotationally driven by superheated steam superheated in the boiler and drives a generator;
a heat storage device that collects and stores surplus energy passing through the interior;
a control device that controls so that the surplus energy generated during operation including when starting and stopping is stored in the heat storage device;
Equipped with
The surplus energy is surplus thermal energy of the superheated steam generated in the boiler.
surplus heat energy,
The heat storage device is
Each has a different temperature
Multiple heat storage parts with temperature characteristics in the degree range,
Opening/closing that operates according to instructions from the control device and controls the inflow of the fluid into the flow path.
comprising a valve;
The control device is configured to control the control device so that the control device generates the
The surplus thermal energy is in the form of a fluid and has temperature characteristics in a temperature range to which the temperature of the surplus thermal energy belongs.
Control the opening and closing of the on-off valve so that the flow path first passes through the heat storage section having a
to do
A power generation plant featuring: The power generation plant according to claim 1 ,
a water supply line that returns exhaust steam from the steam turbine to water and supplies it to the boiler;
Further comprising a main steam bypass pipe that branches from a main steam pipe that supplies the superheated steam from the boiler to the steam turbine and discharges the superheated steam to the water supply line,
The heat storage section is
a first heat storage part having temperature characteristics in a first temperature range;
a second heat storage part having temperature characteristics in a second temperature range that is a lower temperature range than the first temperature range,
The flow path is
A main steam bypass pipe connected to the main steam bypass pipe, which causes the fluid flowing into the heat storage device to pass through the first heat storage section and the second heat storage section in order, and discharges the fluid from the heat storage device to the main steam bypass pipe. Equipped with a first-class passage,
The control device is operated from the start of ventilation until the load of the boiler matches the generator load of the steam turbine, and in a state where the generator load of the steam turbine is smaller than the minimum load of the boiler by a predetermined amount. A power generation plant characterized in that opening and closing of the on-off valve is controlled so that the fluid flows into the first main steam flow path during at least one of the periods during which the fluid flows into the first main steam flow path. The power generation plant according to claim 2 ,
Further comprising a boiler bleed pipe that branches from a pipe in a superheater included in the boiler and discharges superheated steam in the boiler to the water supply line,
The flow path is
A main body connected to the main steam bypass pipe that causes the fluid flowing into the heat storage device to bypass the first heat storage portion, pass through the second heat storage portion, and discharge from the heat storage device to the main steam bypass pipe. a third steam flow path;
further comprising: a boiler exhaust flow path connected to the boiler bleed pipe and configured to cause the fluid flowing into the heat storage device to pass through the second heat storage section and be discharged to the boiler bleed pipe;
The control device is configured such that the fluid flows into the third main steam flow path and the boiler exhaust flow path, and the fluid does not flow into the first main steam flow path, from ignition to the boiler until the start of ventilation. A power generation plant characterized in that the opening and closing of the on-off valve is controlled in such a manner. The power generation plant according to claim 2 or 3 ,
The control device controls opening and closing of the on-off valve so that the fluid flows into the first main steam flow path when the generator load of the steam turbine is less than the boiler load when the power generation plant is stopped. A power generation plant featuring: The power generation plant according to claim 2 ,
The steam turbine includes a high pressure steam turbine and a medium and low pressure steam turbine,
The boiler includes a reheater that reheats the steam after rotationally driving the high-pressure steam turbine,
The main steam pipe supplies the superheated steam to the high pressure steam turbine,
The power generation plant is
a low-temperature reheat steam pipe that supplies the rotationally driven steam to the reheater;
a high-temperature reheat steam pipe that supplies steam resuperheated in the reheater to the medium and low pressure steam turbine;
a high-pressure steam turbine bypass pipe that branches from the main steam pipe and supplies the overheated steam to the low-temperature reheat steam pipe, bypassing the high-pressure steam turbine;
Further comprising a reheat steam bypass pipe branching from the high temperature reheat steam pipe and discharging steam in the high temperature reheat steam pipe to the water supply line,
The flow path is
A reheating device that is connected to the reheat steam bypass pipe and causes the fluid flowing into the heat storage device to pass through the first heat storage section and the second heat storage section in order, and is discharged from the heat storage device to the reheat steam bypass pipe. a first hot steam flow path;
The fluid connected to the reheat steam bypass pipe and flowing into the heat storage device bypasses the first heat storage section, passes through the second heat storage section, and is discharged from the heat storage device to the reheat steam bypass pipe. further comprising: a third reheat steam flow path;
The control device is operated from the start of ventilation until the load of the boiler matches the generator load of the steam turbine, and in a state where the generator load of the steam turbine is smaller than the minimum load of the boiler by a predetermined amount. A power generation plant characterized in that opening and closing of the on-off valve is controlled so that the fluid flows into the first reheat steam flow path during at least one of the periods during which the reheat steam is reheated. The power generation plant according to claim 5 ,
The control device controls the on-off valve so that the fluid flows into the third reheat steam flow path and the fluid does not flow into the first reheat steam flow path during a period from ignition to the boiler until the start of ventilation. A power generation plant characterized by controlling the opening and closing of. The power generation plant according to claim 5 or 6 ,
The control device controls the control device so that the fluid flows into the main steam first flow path and the reheat steam first flow path when the generator load of the steam turbine is less than the boiler load when the power generation plant is stopped. A power generation plant characterized by controlling the opening and closing of on-off valves. The power generation plant according to claim 2 ,
The heat storage section further includes a third heat storage section having temperature characteristics in a third temperature range that is a lower temperature range than the second temperature range,
The power generation plant, wherein the control device controls opening and closing of the on-off valve so that the fluid that has passed through the second heat storage section passes through the third heat storage section and is discharged from the heat storage device. The power plant according to claim 8 ,
Further comprising a saturated water pipe that discharges saturated water generated in a brackish water separator included in the boiler to the water supply line,
The flow path is
A power generation plant further comprising: a saturated water flow path connected to the saturated water pipe and configured to cause the saturated water flowing into the heat storage device to pass through the third heat storage section and be discharged to the saturated water pipe. The power generation plant according to claim 2 ,
further comprising a temperature sensor that detects the temperature of the superheated steam in the main steam pipe,
The power generation plant, wherein the control device identifies an event for controlling opening and closing of the on-off valve based on the output of the temperature sensor. The power generation plant according to claim 10 ,
The power generation plant, wherein the first temperature range and the second temperature range are each determined in correspondence with the temperature at the time of the specified event. The power generation plant according to claim 10 ,
A power generation plant characterized in that a capacity of each of the first heat storage section and the second heat storage section is determined according to the thermal energy generated between the events. a boiler that heats supplied water to generate superheated steam;
a steam turbine that is rotationally driven by superheated steam superheated in the boiler and drives a generator;
A heat storage device that stores thermal energy;
The boiler is
a first boiler heat exchange section that generates a fluid having a temperature in a first temperature range through heat exchange;
a second boiler heat exchange section that generates a fluid having a temperature in a second temperature range that is lower than the first temperature range by heat exchange;
The heat storage device is
a first heat storage section that stores thermal energy in the first temperature range;
a second heat storage section that stores thermal energy in the second temperature range;
A part of the fluid generated in the second boiler heat exchange section is guided to the second heat storage section, and after recovering the thermal energy in the second heat storage section, a second heat is guided to the first boiler heat exchange section. a collection pipe;
A part of the fluid generated in the first boiler heat exchange section is guided to the first heat storage section, and after recovering the thermal energy in the first heat storage section, it is guided to the outlet side of the first boiler heat exchange section. A power generation plant comprising a first heat recovery pipe. 14. The power plant according to claim 13 ,
further comprising a control device;
The heat storage device further includes a heat recovery on/off valve that operates according to instructions from the control device and controls the inflow of the fluid into each of the first heat recovery pipe and the second heat recovery pipe,
The control device includes:
The fluid flows into the first heat recovery pipe and the second heat recovery pipe during at least one of the following events: when starting up the power plant, suppressing heat output from the boiler, and promoting driving of the steam turbine. A power generation plant characterized in that opening and closing of the heat recovery on-off valve is controlled in such a manner. a boiler that heats supplied water to generate superheated steam;
a steam turbine that is rotationally driven by superheated steam superheated in the boiler and drives a generator;
a heat storage device that collects and stores surplus energy passing through the interior;
a control device that controls so that the surplus energy generated during operation including when starting and stopping is stored in the heat storage device;
A power generation plant comprising :
The surplus energy includes surplus power energy that is surplus power energy,
The heat storage device includes a heater heated by the surplus electric energy in a heat storage section provided therein,
The power generation plant, wherein the control device operates the heater when receiving a power supply command that is less than a predetermined load of the power generation plant. The power generation plant according to claim 1 ,
The surplus energy includes surplus power energy that is surplus power energy,
The heat storage device includes a heater heated by the surplus electric energy in a heat storage section provided therein,
The power generation plant, wherein the control device operates the heater when receiving a power supply command that is less than a predetermined load of the power generation plant. The power plant according to claim 15 or 16,
The heat storage device includes a plurality of the heat storage parts,
A power generation plant characterized in that each heat storage section has temperature characteristics in different temperature ranges. a boiler that heats supplied water to generate superheated steam;
a steam turbine that is rotationally driven by superheated steam superheated in the boiler and drives a generator;
Equipped with a heat storage device that stores surplus energy,
The boiler includes a first boiler heat exchange section that generates a fluid having a temperature in a first temperature range by heat exchange,
The heat storage device includes a first heat storage section that stores heat energy in the first temperature range;
A part of the fluid generated in the first boiler heat exchange section is guided to the first heat storage section, and after recovering the thermal energy in the first heat storage section, it is guided to the outlet side of the first boiler heat exchange section. A power generation plant comprising a first heat recovery pipe. 19. The power plant according to claim 18,
The boiler further includes a second boiler heat exchange section that generates a fluid having a temperature in a second temperature range that is lower than the first temperature range by heat exchange,
The heat storage device is
a second heat storage section that stores thermal energy in the second temperature range;
A part of the fluid generated in the second boiler heat exchange section is guided to the second heat storage section, and after recovering the thermal energy in the second heat storage section, a second heat is guided to the first boiler heat exchange section. A power generation plant further comprising a recovery pipe. a boiler that heats supplied water to generate superheated steam;
a steam turbine that is rotationally driven by superheated steam superheated in the boiler and drives a generator;
A method for storing surplus energy in a power generation plant, the method comprising: a heat storage device that collects and stores surplus energy passing through the power plant;
When the surplus energy is generated during operation including when starting and stopping, controlling the surplus energy to be stored in the heat storage device ,
The surplus energy is surplus thermal energy of the superheated steam generated in the boiler.
surplus heat energy,
The heat storage device is
Each has a different temperature
Multiple heat storage parts with temperature characteristics in the degree range,
an on-off valve that operates according to instructions from a control device and controls the inflow of the fluid into the flow path;
, comprising:
Before occurring at least one of the startup time and the shutdown time of the power generation plant.
The surplus thermal energy is in the form of a fluid and has a temperature characteristic in a temperature range to which the temperature of the surplus thermal energy belongs.
The opening and closing of the on-off valve is controlled so that the heat flows into the flow path that first passes through the heat storage section having a
to control
A method for storing surplus energy in a power generation plant characterized by: a boiler that heats supplied water to generate superheated steam;
a steam turbine that is rotationally driven by superheated steam superheated in the boiler and drives a generator;
,
A power generation plant equipped with a heat storage device that collects and stores surplus energy passing through the inside.
1. A method for storing surplus energy heat in a
If the surplus energy is generated during operation, including when starting and stopping, the surplus energy
control to store heat in the heat storage device,
The surplus energy includes surplus power energy that is surplus power energy,
The heat storage device includes a heater heated by the surplus electric energy in a heat storage section provided therein,
A method for storing surplus energy in a power generation plant, comprising: controlling the heater so as to operate the heater when a power supply command that is lower than a predetermined load of the power generation plant is received. 21. A method for storing surplus energy in a power generation plant according to claim 20 , comprising:
The surplus energy includes surplus power energy that is surplus power energy,
The heat storage device includes a heater heated by the surplus electric energy in a heat storage section provided therein,
A method for storing surplus energy in a power generation plant, comprising: controlling the heater so as to operate the heater when a power supply command that is lower than a predetermined load of the power generation plant is received.