WO2020116167A1 - Solar thermal power generation system - Google Patents

Abstract

This solar thermal power generation system has a solar heat collection device (2), a heat storage device (4), a vapor turbine (31), a generator (32), a condenser (51), a water tank (52), and a water supply pump (53). It is possible to switch between a daytime operation mode in which the storing of heat in the heat storage device (4) and the operation of the vapor turbine (31) are performed by heated vapor supplied from the solar heat collection device (2), and a nighttime operation mode in which the vapor turbine (31) is operated by heated vapor produced by heating by means of heat released from the heat storage device (4). The heat storage device (4) incorporates a chemical heat storage material capable of storing and releasing heat by means of a chemical reaction. Further, the heat storage device (4) is connected to a reactant storage (6) and is configured so that a reactant utilized for the chemical reaction of the chemical heat storage material can be supplied from the reactant storage (6) to the heat storage device (4).

Description

Solar thermal power generation system

The present invention relates to a solar thermal power generation system.

　As one of the power generation systems that use natural energy, there is a solar thermal power generation system that uses the heat energy emitted from the sun to generate electricity. A solar thermal power generation system collects solar heat to heat water (water or steam) directly or indirectly through a heat medium to heat superheated steam or saturated steam (hereinafter collectively referred to as “collection of these” in a daytime with a lot of sunlight. "Heated steam") is generated, the steam turbine is rotated by the steam, and power is generated by a generator connected to the steam turbine. Then, at night without sunlight, a part of the solar heat is stored in the heat storage device in the daytime, and heating steam is generated by heat radiation from the heat storage device to generate power in the same manner as described above. Many.

　To make effective use of the solar thermal power generation system, it is necessary to generate power at night more efficiently than ever before. In order to perform night-time power generation, it is essential to use a heat storage device capable of storing heat in the daytime and radiating heat at night to heat water directly or indirectly via a heat medium. In the system in which oil or molten salt is used as the heat medium to exchange heat between the heat medium and water to generate heated steam, the heat medium itself can be stored and used as a heat storage device. On the other hand, in a system using the DSG (Direct Steam Generation) method using water as a heat medium, a pressure accumulator such as an accumulator may be used as a heat storage device for storing heated steam. Although they are not suitable for long-term storage and use, they require huge equipment.

On the other hand, from the viewpoint of equipment cost, power generation efficiency from transmitted solar heat, environmental aspects, and simplification of system configuration, a system using the DSG method using water as a heat medium is considered to be advantageous, and is excellent. It is desired to develop a heat storage device.

As a solar thermal power generation system, for example, the one described in Patent Document 1 is considered, but there is a problem to be improved in this system. The technique of Patent Document 1 adopts the DSG method, and includes three types of heat storage tanks corresponding to water states, that is, superheated steam, saturated steam, and saturated water states, as a heat storage device. Is. However, the provision of the three types of heat storage devices complicates the piping configuration and the like, and increases the heat loss due to the long transport path of the heat medium, and further increases the equipment cost.

Japanese Unexamined Patent Publication No. 2014-092086

As described above, although various technologies that use the DSG method as a solar thermal power generation system have been proposed in the past, in many cases, piping must be configured in a complicated manner to install a heat storage device. This leads to an increase in loss.

The present invention has been made in view of such a background, and it is an object of the present invention to provide a simple solar thermal power generation system that adopts the DSG method and has a small heat loss in a path necessary for a heat storage device.

One aspect of the present invention, a solar heat collector that directly heats a heat medium made of water by the collected solar heat to generate heated steam,
A heat storage device that performs heat exchange with the heat medium to store heat and radiate heat,
A steam turbine driven by heated steam,
A generator for generating power by the power of the steam turbine,
A condenser for condensing steam discharged from the steam turbine;
A water tank that stores the reconstituted water,
A water supply pump for pumping water from the water tank,
A daytime operation mode of performing heat storage to the heat storage device and operation of the steam turbine by the heating steam supplied from the solar heat collector.
It is configured to be able to switch between the night operation mode in which the steam turbine is operated by the heated steam that is heated by receiving the heat radiation of the heat storage device,
The heat storage device contains a chemical heat storage material capable of storing heat and releasing heat by a chemical reaction, and is further connected to a reactant storage device, and a reaction material used in association with the chemical reaction of the chemical heat storage material, A solar thermal power generation system is configured to be able to supply from the reactant storage device to the heat storage device.
The night operation mode is not limited to the night operation mode, and includes a case where the sunshine such as cloudy day is insufficient in the daytime.

In the solar thermal power generation system, as described above, after adopting the DSG method using water (including water, steam, and a mixed state of water and steam. The same applies hereinafter) as a heat medium, a chemical heat storage material is incorporated. Uses a heat storage device. The chemical heat storage material has a characteristic of receiving a heat transfer from a heat medium to cause a chemical reaction of releasing a reactant and storing the heat, and causing a chemical reaction of incorporating the reactant to radiate heat. Then, by utilizing the reversible reaction, it is possible to repeatedly store and radiate heat, and the heat storage energy density is high, so that stable radiative use for a long time is possible.

Here, in the solar thermal power generation system, the reactant stored in the reactant reservoir is used as the reactant released or introduced along with the reaction of the chemical heat storage material. By positively adopting this configuration, the path required for the heat storage device can be simplified and shortened, and the thermal efficiency can be improved.

As described above, according to the above aspect, it is possible to provide a simple solar thermal power generation system that adopts the DSG method and has a small heat loss in the path required for the heat storage device.

Explanatory drawing which shows the structure of the solar thermal power generation system in Example 1. FIG. FIG. 6 is an explanatory diagram showing a configuration of a solar thermal power generation system according to a second embodiment. Explanatory drawing which shows the structure of the solar thermal power generation system in Example 3. FIG.

In the solar thermal power generation system, various types of trough type, Fresnel type, tower type and the like can be adopted as the solar heat collector. In addition, as the steam turbine, the generator, the condenser, the water supply pump, the piping configuration and other components, various known components can be adopted.

Also, as the heat storage device, as mentioned above, a device that incorporates a chemical heat storage material that stores and dissipates heat by a chemical reaction is adopted. Examples of this type of chemical heat storage material include oxides of alkaline earth metals such as calcium oxide (CaO), magnesium oxide (MgO), and barium oxide (BaO).

The chemical heat storage material radiates heat in accordance with a hydration reaction that takes in water (H ₂ O) or a carbonation reaction that takes in carbon dioxide (CO ₂ ), and receives heat transfer from a heat medium to release water. Heat is stored by the reaction or the decarboxylation reaction that releases carbon dioxide, and is regenerated into an oxide. Then, the reversible reaction can be used to repeatedly store and radiate heat, and the heat storage energy density is high, so that stable radiative use for a long time is possible.

The reactive substance used in association with the chemical reaction of the chemical heat storage material incorporated in the heat storage device in the solar thermal power generation system is either water or carbon dioxide.

Further, the reactant storage device is configured to be able to supply, to the heat storage device, the reactant used in association with the chemical reaction of the chemical heat storage material contained in the heat storage device. At this time, the reactant may be transferred between the reactant reservoir and the heat storage device. That is, not only can the reactant be supplied from the reactant storage device to the heat storage device, but the reactant released from the heat storage device can also be recovered and stored in the reaction device storage device.

Further, the solar thermal power generation system includes a plurality of the solar heat collectors, a plurality of the heat storage device, and a plurality of the reactant storage device, in the daytime operation mode, the heat medium, At least, after sequentially passing through the first solar heat collector, the first heat storage device, the second solar heat collector, the second heat storage device, and the third solar heat collector, the The heat medium is supplied to the steam turbine, and in the night operation mode, the flow paths of the heat medium are branched and supplied to the first and second heat storage devices respectively, and after being heated, they are merged and supplied to the steam turbine. In addition, the reactant may be supplied from the first and second reactant storage devices to the first and second heat storage devices, respectively.

In this case, by combining a plurality of solar heat collectors and a plurality of heat storage devices, it is possible to increase the amount of heat storage even if the capacity of each heat storage device is not high. Further, since the heat storage device can be downsized and the capacity thereof can be reduced, the facility cost can be reduced as compared with the case where the large heat storage device is provided. In addition, it is possible to optimize the balance of the amount of power generation during the day and night, and it is possible to supply steam in accordance with the turbine scale throughout the day and night, thus improving energy efficiency.

Further, even if the capacity of each solar heat collector is not high, it is sufficient to collect heat by the amount of heat stored by the heat storage device by one heat exchange, so that the solar heat collector can be miniaturized and reduced in capacity. Therefore, the equipment cost can be reduced and the energy efficiency in heat storage can be improved as compared with the case where the large-sized solar heat collector is provided.

The number of the solar heat collector and the number of the heat storage device do not have to be the same, and the number and arrangement of specific devices may be appropriately adjusted, such as combining those having different capacities in series or in parallel. Good. The same applies hereinafter.

Moreover, the solar thermal power generation system includes a plurality of the solar heat collectors, and in the daytime operation mode, the flow path of the heat medium that has passed through the first solar heat collector is branched to form a daytime mainstream. And the daytime stream are formed, the heat medium of the daytime main stream is supplied to the steam turbine, and the heat medium of the daytime stream sequentially passes through the second solar heat collecting device and the heat storage device, and then again the second heat collecting device. Continuing the repeated circulation of sequentially passing through the solar heat collector and the heat storage device, in the night operation mode, the heat medium is supplied to the heat storage device, heated, and then supplied to the steam turbine. The reactant may be supplied from the reactant reservoir to the heat storage device.

In this case, a circulation path is formed as a heat medium flow path, and the solar heat collector and the heat storage device are arranged in the circulation path. By adopting this configuration, it is possible to optimize the balance of the amount of power generation during the day and night, and it is possible to supply steam in accordance with the scale of the turbine throughout the day and night, so that the effect of improving energy efficiency can be obtained. Further, even if the capacity of the solar heat collector in the circulation path is not high, it is sufficient to collect heat by the amount of heat stored by the heat storage device by one heat exchange, so that the solar heat collector can be downsized and have low capability. It is possible to reduce the equipment cost.

(Example 1)
An example according to the solar thermal power generation system 101 of the present application will be described with reference to FIG.
As shown in FIG. 1, the solar thermal power generation system 101 according to the present embodiment heat-exchanges the solar heat collector 2 that directly heats a heat medium composed of water with the collected solar heat to generate heating steam, and the heat medium. The heat storage device 4 for performing heat storage and heat dissipation, a steam turbine 31 driven by heated steam, a generator 32 for generating power by the power of the steam turbine 31, and steam discharged from the steam turbine 31 to condensate water. The condenser 51, the water tank 52 that stores the condensed water, and the water supply pump 53 that pumps the water from the water tank 52. Then, a daytime operation mode in which heat is stored in the heat storage device 4 and the steam turbine 31 is operated by the heating steam supplied from the solar heat collector 2, and heating is performed by receiving heat radiation from the heat storage device 4. The night operation mode in which the steam turbine 31 is operated by steam can be switched. The heat storage device 4 has a built-in chemical heat storage material capable of storing and releasing heat by a chemical reaction, and is further connected to a reactant storage device 6 to be used in association with the chemical reaction of the chemical heat storage material. Can be supplied from the reactant storage device 6 to the heat storage device 4.
Further details will be given below.

As described above, the solar thermal power generation system 101 according to the present embodiment has a configuration including the solar heat collector 2, the heat storage device 4, and the reactant storage device 6. Then, the pipe 7 for circulating the heat medium has a plurality of open/close valves 801, 802 so as to connect the solar heat collector 2, the heat storage device 4, the steam turbine 31, the condenser 51, the water tank 52, and the water supply pump 53. It is arranged while intervening.

The heat storage device 4 of the present embodiment incorporates CaO/Ca(OH) ₂ , CaO/CaCO ₃ , MgO/Mg(OH) ₂ , MgO/MgCO _3, etc. as the chemical heat storage material. CaO and Ca(OH) ₂ , CaO and CaCO ₃ , MgO and Mg(OH) ₂ , and MgO and MgCO ₃ have reversibly changeable characteristics. Specifically, CaO and Ca(OH) ₂ cause the dehydration reaction of Equation 1 when heat is stored and the hydration reaction of Equation 2 when heat is released. Further, CaO and CaCO ₃ cause a reaction of releasing carbon dioxide of Formula 3 during heat storage, and CaO ₃ reacts with carbon dioxide as in Formula 4 during heat release to cause a reaction of becoming CaCO ₃ . The same applies to MgO and Mg(OH) ₂ , and MgO and MgCO ₃ .
Formula 1: Ca(OH) ₂ + heat → CaO + water (water or steam)
Formula 2: CaO + water (water or water vapor) → Ca(OH) ₂ + heat Formula 3: CaCO ₃ + heat → CaO + CO ₂ (carbon dioxide)
Formula 4: CaO+CO ₂ (carbon dioxide) → CaCO ₃ + heat

The heat storage device 4 includes a heat medium passage 43 in which a heat medium for exchanging heat with the chemical heat storage material is circulated, and a reaction material passage for releasing and introducing a reactant during a chemical reaction in the chemical heat storage material. 44, and the reactant flow path 44 is connected to the reactant storage device 6.

The reactant storage device 6 of this embodiment supplies water or carbon dioxide to the heat storage device 4 as the above-mentioned reactant. For example, when the reaction substance is water (hereinafter, referred to as reaction water), when the heat storage device 4 radiates heat, the reaction water is accumulated from the reaction substance reservoir 6 by a pump or the like via the reaction substance flow path 44. It can be supplied to the device 4. On the other hand, during heat storage, the reaction water generated by the dehydration reaction of the chemical heat storage material contained in the heat storage device 4 is transferred from the heat storage device 4 to the reactant storage device 6 via the reactant flow path 44 by a pump or the like. Can be sent. That is, the reaction water can be transferred between the reactant storage device 6 and the heat storage device 4.

Further, for example, when the reactant is carbon dioxide, when the heat storage device 4 radiates heat, the high-pressure tank filled with carbon dioxide serves as the reactant reservoir 6 and the valve of the high-pressure tank is opened. Carbon dioxide can be supplied to the heat storage device 4 via the flow path 44. On the other hand, during heat storage, carbon dioxide generated from the chemical heat storage material contained in the heat storage device 4 can be sent from the heat storage device 4 to the reactant storage device 6 via the reactant flow path 44 by a pump or the like. .. That is, carbon dioxide can be transferred between the reactant storage device 6 and the heat storage device 4.

The details of the flow path of the heat medium in the configuration of this embodiment will be described below by dividing into the daytime operation mode and the nighttime operation mode of the solar thermal power generation system 101. In addition, in the first embodiment and other embodiments after that, the configuration of the system is shown using the drawings, and in the following description, the temperature of the heat medium is also described for the sake of clarity, but this is only an example. However, it goes without saying that it can actually be changed by setting the capability of each device.

The flow path of the heat medium in the daytime operation mode in the solar thermal power generation system 101 is, as shown in FIG. 1, first, the heat medium in the water tank 52 is pressure-fed by the water supply pump 53, and the solar heat collector 2 is moved along the direction of arrow A. Sent to. In the solar heat collector 2, the heat medium at 30° C. is heated by the collected solar heat to become heated steam at 600° C., and is sent to the heat medium passage 43 of the heat storage device 4 along the direction of arrow A. .. In the heat storage device 4, heat of 100° C. is stored from the heat medium of 600° C. Then, the heated steam having a temperature of 500° C. is sent from the heat medium flow path 43 of the heat storage device 4 to the steam turbine 31, and the steam turbine 31 is driven to generate power by the generator 32. The heated steam (heat medium) discharged from the steam turbine 31 is condensed by the condenser 51 and returned to the water tank 52 for storage.

Here, in the daytime operation mode, as described above, the heat storage device 4 stores 100° C. of heat. At this time, the chemical heat storage material contained in the heat storage device 4 causes a chemical reaction such as Equation 1 or Equation 3 illustrated above, and releases the reactant. This reactant may flow and be stored through the reactant channel 44 along the direction of arrow a1 toward the reactant reservoir 6.

Next, in the night operation mode of the solar thermal power generation system 101, the flow path of the pipe 7 connected to the solar heat collector 2 is stopped by closing the opening/closing valve 801. On the other hand, the opening/closing valve 802 of the pipe 7 connected to the heat storage device 4 from the water supply pump 53 in the direction of the arrow B is opened. Then, the heat medium in the water tank 52 is pressure-fed by the water supply pump 53 and heads for the heat storage device 4 along the direction of arrow B. The heat medium of 30° C. directed to the heat storage device 4 is supplied to the heat medium flow path 43 of the heat storage device 4, heated to 500° C. by heat exchange with the chemical heat storage material, and then supplied to the steam turbine 31 and the generator. Power is generated by 32. The heated steam (heat medium) discharged from the steam turbine 31 is condensed by the condenser 51 and returned to the water tank 52 for storage.

Further, the reactant is supplied from the reactant storage device 6 along the direction of the arrow a2 to the heat storage device 4 through the reactant flow path 44, and is used for the chemical reaction accompanying the heat dissipation of the chemical heat storage material. In the heat storage device 4, the heat medium is heated as described above by the heat generated by the chemical reaction between the reactant and the chemical heat storage material.

In the daytime operation mode and nighttime operation mode as described above, the opening/closing valves in the pipe 7 through which the heat medium passes are opened, and the other opening/closing valves are closed.

In the solar thermal power generation system 101 of this embodiment, since the reactant storage device 6 can be installed at a desired position, the path required for the heat storage device 4 is shortened and the structure can be further simplified. Further, along with this, it is possible to reduce the heat loss on the route and the energy required for transporting the reactant.

Further, in the solar thermal power generation system 101 of the present embodiment, the reactant stored in the reactant storage device 6 can be used as the reactant released or introduced along with the reaction of the chemical heat storage material. In other words, it has a transport path for the reactant that is independent of the heat medium path of the solar thermal power generation system 101. By positively adopting this configuration, the reactant used for the chemical heat storage material is not limited to water, and carbon dioxide can also be used, so that the range of choices for the chemical heat storage material and the reaction material is expanded. Therefore, it is possible to generate power according to the location where the solar thermal power generation system 101 is installed, the usage conditions, and the like. In addition, since the temperature required for heat storage and the temperature to be radiated differ depending on the difference between the chemical heat storage material and the reactant, power generation using a heat medium adjusted to a suitable temperature becomes possible.

In addition, the reactant storage device 6 can supply the reactant to the heat storage device 4 and does not interfere with the heat medium path of the solar thermal power generation system 101, so that the control becomes easy. Furthermore, since the reactant used in the heat storage device 4 is not limited to water, the amount of water used can be reduced.

(Example 2)
The solar thermal power generation system 102 of the present embodiment is an example in which a solar heat collector, a heat storage device, and a reactant storage device are added based on the configuration of the first embodiment. That is, as shown in FIG. 2, a first heat storage device 41 is provided on the downstream side of the first solar heat collecting device 21, a second solar heat collecting device 22 is provided on the downstream side thereof, and a second solar heat collecting device 22 is provided on the downstream side thereof. The heat storage device 42 is provided, and the third solar heat collector 23 is further provided on the downstream side. Further, in each of the heat storage devices 41 and 42, it is connected to the reactant storage devices 61 and 62 via the reactant flow paths 414 and 424, and the reactant used for the chemical reaction of the chemical heat storage material can be supplied. Is becoming For convenience of description, components having the same functions as those in the first embodiment will be described using the same reference numerals as those in the first embodiment. Hereinafter, the same applies to the third embodiment.

In the daytime operation mode in this example, the heat medium in the water tank 52 is pressure-fed by the water supply pump 53 and is fed to the first solar heat collector 21 in the direction of arrow A. In the first solar heat collector 21, the heat medium of 30° C. is heated by the collected solar heat into heated steam of 600° C., and then the heat medium of the first heat storage device 41 along the direction of arrow A. It is sent to the flow path 413. In the first heat storage device 41, heat of 100° C. is stored from the heat medium of 600° C. and becomes heated steam of 500° C.

Next, the heated steam that has reached 500° C. is sent to the second solar heat collector 22 on the downstream side along the direction of arrow A, is heated to 600° C. again, and then the second heat storage on the downstream side. It is sent to the heat medium flow path 423 of the device 42, and heat of 100° C. is accumulated from the heat medium of 600° C., and the heat medium becomes 500° C. Then, along the direction of the arrow A, is sent to the third solar heat collector 23 further downstream and heated to 600° C. again, and then sent from the third solar heat collector 23 to the steam turbine 31, Power is generated in the same manner as described above. The heated steam (heat medium) discharged from the steam turbine 31 is condensed by the condenser 51 and returned to the water tank 52 for storage.

Also, in the daytime operation mode, heat of 100° C. is stored in each of the first and second heat storage devices 41 and 42. At this time, the reactant released from the first and second heat storage devices 41, 42 passes through the respective reactant passages 414, 424 along the direction of the arrow a1 to reach the reactant reservoirs 61, 62. It may be sent and stored.

Next, in the night operation mode of the solar thermal power generation system 102, the flow path of the pipe 7 connected to the first to third solar heat collectors 21, 22, 23 is stopped by closing the opening/closing valves 801, 803, 804. .. On the other hand, the on-off valves 802 and 806 of the pipe 7 connected to the first and second heat storage devices 41 and 42 from the water supply pump 53 along the direction of the arrow B and the first and second heat storage devices 41 and 42 to the arrow B. The on-off valves 805, 807 of the pipe 7 connected to the steam turbine 31 along the direction are opened.

Then, the heat medium in the water tank 52 is pressure-fed by the water supply pump 53, and goes toward the first and second heat storage devices 41 and 42 along the flow path indicated by the arrow B. The heat medium supplied to the heat medium flow paths 413 and 423 of the heat storage devices 41 and 42 is heated to 500° C. by heat exchange with the chemical heat storage material.

The heat medium heated in each heat storage device 41, 42 merges along the direction of arrow B through the bypass 7 (b) without being sent to the solar heat collectors 22, 23, and the steam turbine 31 And is generated by the generator 32. The heated steam (heat medium) discharged from the steam turbine 31 is condensed by the condenser 51 and returned to the water tank 52 for storage.

Further, the reactants are supplied from the reactant reservoirs 61, 62 to the heat storage devices 41, 42 along the direction of arrow a2. In the heat storage devices 41 and 42, the heat medium is heated as described above by the heat generated by the chemical reaction between the reactant and the chemical heat storage material.

In the case of the present embodiment, by providing a plurality of solar heat collectors 21, 22, 23, and further by providing heat storage devices 41, 42 between them, in addition to the function and effect shown in Embodiment 1, day and night The balance of power generation can be optimized. Further, since it is possible to supply steam in accordance with the scale of the turbine throughout the day and night, it is possible to obtain the effect of improving energy efficiency.

Also, even if the capacity of each heat storage device is not high, it is possible to increase the amount of heat storage by having multiple heat storage devices. Further, since the heat storage device can be downsized and its capacity can be reduced, the facility cost can be reduced as compared with the case where the large heat storage device is provided.

Further, even if the capacity of each solar heat collector is not high, it is sufficient to collect heat by the amount of heat stored by the heat storage device by one heat exchange, so that the solar heat collector can be miniaturized and reduced in capacity. Therefore, the equipment cost can be reduced and the energy efficiency in heat storage can be improved as compared with the case where the large-sized solar heat collector is provided.

(Example 3)
In the daytime operation mode, the solar thermal power generation system 103 of the present example enables repeated circulation flow in which the solar heat collector and the heat storage device are sequentially passed and then the solar heat collector and the heat storage device are sequentially passed again. That is, as shown in FIG. 3, the downstream side of the heat storage device 4 and the upstream side of the solar heat collector 22 are connected by the circulation path 7(c).

In the daytime operation mode in this example, the heat medium in the water tank 52 is pressure-fed by the water supply pump 53 and is fed to the first solar heat collector 21 along the direction of arrow A. In the first solar heat collector 21, the heat medium at 30° C. is heated to 500° C. by the collected solar heat and becomes heated steam.

The flow path of the heat medium that has passed through the first solar heat collector 21 is branched to form a daytime main stream along the direction of arrow A1 and a daytime branch stream along the direction of arrow A2. Is supplied to the steam turbine 31 along the direction of arrow A1, and power generation is performed in the same manner as described above. The heated steam (heat medium) discharged from the steam turbine 31 is condensed by the condenser 51 and returned to the water tank 52 for storage.

The heat medium of the daytime flow first passes through the second solar heat collector 22 along the direction of arrow A2 to be heated to 600° C., and then passes through the heat medium passage 43 of the heat storage device 4. The heat of 100° C. is accumulated to 500° C., and then the circulation path 7(c) is advanced along the direction of the arrow A2, and the repetitive circulation of sequentially passing through the second solar heat collecting device 22 and the heat storing device 4 again is performed. to continue.

The reactant released from the chemical heat storage material in the heat storage device 4 during heat storage may be sent to the reactant storage device 6 and stored therein through the reactant flow path 44 along the direction of arrow a1.

Next, in the night operation mode of the present embodiment, the flow path of the pipe 7 connected to the first solar heat collector 21 and the steam turbine 31 from the first solar heat collector 21 along the direction of arrow A1. The flow path of the connected pipe 7 and the flow path of the circulation path 7(c) are stopped by closing the opening/closing valves 801, 808, 809. On the other hand, the on-off valve 802 of the pipe 7 connected to the heat storage device 4 from the water supply pump 53 along the direction of the arrow B and the on-off valve 810 of the pipe 7 connected to the steam turbine 31 from the heat storage device 4 along the direction of the arrow B are opened. It

Then, the heat medium at 30° C. in the water tank 52 is pressure-fed by the water supply pump 53, is supplied to the heat medium passage 43 of the heat storage device 4 along the direction of the arrow B, and is 500° C. by heat exchange with the chemical heat storage material. After being heated to 1, it is supplied to the steam turbine 31 and is generated by the generator 32. The heated steam (heat medium) discharged from the steam turbine 31 is condensed by the condenser 51 and returned to the water tank 52 for storage.

Further, the reactant is sent from the reactant reservoir 6 through the reactant channel 44 in the direction of arrow a2 to the heat storage device 4 and supplied to the chemical heat storage material. In the heat storage device 4, the heat medium is heated as described above by the heat generated by the chemical reaction between the reactant and the chemical heat storage material.

In the case of the present embodiment, in the daytime operation mode, after repeatedly passing through the solar heat collector 22 and the heat storage device 4, it is possible to repeatedly circulate through the solar heat collector 22 and the heat storage device 4 again. As a result, in addition to the operational effects shown in the first embodiment, it is possible to optimize the balance of the amount of power generation during the day and night, and it is possible to supply steam in accordance with the turbine scale throughout the day and night, so that the effect of improving energy efficiency is obtained. be able to. Further, even if the capacity of the solar heat collector 22 in the circulation path is not high, the second solar heat collector 22 only needs to collect heat on the high-temperature heat medium that has passed through the heat storage device 4, and further the heat storage device. The solar heat collector 22 can be downsized and its capacity can be reduced, and the facility cost can be reduced, because the solar heat collector 22 can collect heat by the amount of heat stored by one heat exchange.

As described above, according to the present embodiment, it is possible to provide a simple solar thermal power generation system that adopts the DSG method and has a small heat loss in the path required for the heat storage device.

Claims (3)

A solar heat collector that directly heats a heat medium consisting of water by the collected solar heat to generate heated steam,
A heat storage device that performs heat exchange with the heat medium to store heat and radiate heat,
A steam turbine driven by heated steam,
A generator for generating power by the power of the steam turbine,
A condenser for condensing steam discharged from the steam turbine;
A water tank that stores the reconstituted water,
A water supply pump for pumping water from the water tank,
A daytime operation mode of performing heat storage to the heat storage device and operation of the steam turbine by the heating steam supplied from the solar heat collector.
It is configured to be able to switch between the night operation mode in which the steam turbine is operated by the heated steam that is heated by receiving the heat radiation of the heat storage device,
The heat storage device has a built-in chemical heat storage material capable of heat storage and heat dissipation by a chemical reaction, and is further connected to a reactant storage device, and a reaction material used in association with the chemical reaction of the chemical heat storage material, A solar thermal power generation system configured to be able to supply from the reactant storage device to the heat storage device. The solar thermal power generation system includes a plurality of the solar heat collectors, a plurality of the heat storage device, a plurality of the reactant storage device,
In the daytime operation mode, the heat medium includes at least a first solar heat collector, a first heat storage device, a second solar heat collector, a second heat storage device, and a third heat storage device. After sequentially passing through the solar heat collector, is supplied to the steam turbine,
In the night operation mode, the flow path of the heat medium is branched and supplied to the first and second heat storage devices, respectively, and after being heated, they are merged and supplied to the steam turbine, and The solar thermal power generation system according to claim 1, wherein the reactant is supplied from the second and second reactant storage devices to the first and second heat storage devices, respectively. The solar thermal power generation system includes a plurality of the solar heat collectors,
In the daytime operation mode, the flow path of the heat medium that has passed through the first solar heat collector is branched to form a daytime main stream and a daytime branch stream, and the heat medium of the daytime main stream is supplied to the steam turbine. The heat medium of the daytime stream sequentially passes through the second solar heat collector and the heat storage device, and then repeats repeated circulation through the second solar heat collector and the heat storage device.
In the night operation mode, the heat medium is supplied to the heat storage device, heated and then supplied to the steam turbine, and the reactant is supplied from the reactant storage device to the heat storage device. The solar thermal power generation system according to claim 1, which is configured to.

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