JP6612042B2 - Solar heat storage device - Google Patents

Description

  The present invention relates to a solar heat storage device, and more particularly, to a solar heat storage device suitable for a solar heat steam generation device that generates heat by heating steam by generating heat by heating solar water with solar radiation.

  The solar heat steam generator used in the concentrating solar power plant changes the amount of heat collection due to fluctuations in the amount of solar radiation, and cannot generate steam directly by solar heat at night when there is no solar radiation. For this reason, it is necessary to install a heat storage device that stores heat when the amount of solar radiation is large and dissipates heat when the amount of solar radiation is insufficient to compensate for the generation of steam.

  By the way, it is desirable that the power plant has a high steam temperature from the viewpoint of efficiency, and the heat storage device also requires a high-temperature heat storage material capable of generating high-temperature steam. For example, in a heat storage material used at a high temperature of 500 to 550 ° C., as described in Patent Document 1, Patent Document 2, and Patent Document 3, sodium nitrate, sodium nitrite, and potassium nitrate that are liquid at the heat storage temperature are used. A molten salt consisting of a mixture is used. The molten salt comprising a eutectic salt of sodium nitrate, sodium nitrite and potassium nitrate disclosed in these patent documents has a melting point of about 140 ° C., a maximum operating temperature of 650 ° C., and a wide operating temperature range. It is suitable for a sensible heat storage device.

  On the other hand, the heat storage material composed of the above-mentioned nitrate-based molten salt has a low thermal conductivity (0.6 W / mK), and therefore, when filled in a container, a temperature deviation is likely to occur. There is a problem that the heater is damaged and the output response is slow. In this regard, the above-mentioned document describes mixing a solid heat storage material mainly composed of clinker-like magnesia with excellent heat conduction, enclosing it in a container to form a heat storage tank, and an electric heater or It is disclosed that a temperature difference is reduced by installing a heat transfer tube.

  Patent Documents 1 and 2 describe that fins are attached to the outer peripheral surface of a heat transfer tube installed in a heat storage tank, and the fin density is increased from the tube inlet side to the tube outlet side. Thereby, the temperature deviation of the heat storage material generated between the entrance and exit of the heat transfer tube can be reduced to increase the amount of steam generated. Patent Documents 1 and 2 disclose that the inlet side of the heat transfer tube is formed of a double tube to prevent damage due to thermal shock.

  Further, Patent Document 2 discloses that an austenitic stainless steel having a chromium content of 14 wt% or more and a carbon content of 0.03 wt% or less is used as the tube material of the heat transfer tube. In Patent Document 3, a heat storage tank in which an electric heater and a heat transfer tube are sealed in a container filled with a heat storage material may be damaged by volume expansion accompanying solidification / melting of the heat storage material when used. For this reason, it is disclosed that the electric heater is installed sufficiently separated from the heat transfer tube through which the fluid to be heated flows.

Japanese Patent No.03153867 Patent 03165961 Japanese Patent No. 0273580

By the way, Patent Documents 1 to 3 do not give consideration to heating the heat storage material by heating the feed water flowing through the heat transfer tubes or steam by flowing the molten salt in the heat storage tank using a pump or the like. For example, in a container that circulates a heat storage material having fluidity, a heat exchanger containing a large number of heat transfer tubes that distribute water and steam is used, and the heat storage material in the container is made to flow by a pump or the like, thereby obtaining It can be expected to solve the problems described in 1-3. However, there is a problem in downsizing a heat storage device having a high heat storage temperature and a large heat storage capacity as in a power plant.

  The problem to be solved by the present invention is to provide a compact solar heat storage device suitable for a solar steam generator.

In order to solve the above problems, a solar heat storage device of the present invention includes a steam pipe that supplies steam generated by a solar heat steam generator to a supply destination, and a water supply pipe that supplies water for the steam to the solar heat steam generator. A heat exchanger formed by accommodating a heat transfer tube in a container, a first heat storage tank that is communicated in the container of the heat exchanger and stores a fluid heat storage material, and a heat exchanger of the heat exchanger A second heat storage tank that is communicated in a container and stores the heat storage material, and a heat storage material transfer that transfers the heat storage material to each other via the heat exchanger between the first heat storage tank and the second heat storage tank. e Bei a pump, the heat transfer tube of the heat exchanger comprises a plurality of heat transfer tubes arranged in parallel are formed in a planar shape by bending into the container, the heat storage material of the first thermal storage tank Between the plurality of heat transfer tubes arranged in a high temperature region in the container where A flow path heat material flows, characterized in that it constituted by arranging the solid heat storage member capacity and thermal conductivity are formed in a large solid heat storage material per volume than said heat storage material.

  According to this invention, a heat storage tank is divided into a 1st heat storage tank (high temperature heat storage tank) and a 2nd heat storage tank (low temperature heat storage tank), and the heat storage material of a high temperature heat storage tank and a low temperature heat storage tank according to heat storage mode and heat dissipation mode. Circulate through the heat exchanger, heat exchange between the feed water or steam circulating in the heat transfer pipe and the heat storage material, heat of the steam is stored in the heat storage material, or the heat of the heat storage material is dissipated to the water supply Can do. Moreover, even if a fluid heat storage material having a low thermal conductivity (0.6 W / mK) is used, it is possible to suppress the occurrence of temperature deviation between the inlet and outlet of the heat transfer tube disposed in the heat exchanger. This can prevent damage to the heat transfer tube. Further, measures such as increasing the fin density from the inlet side to the outlet side of the heat transfer tube are not necessarily required. Furthermore, it is not necessary to form a double tube in order to reduce the thermal shock on the inlet side of the heat transfer tube.

  And since the area | region in the container of the heat exchanger through which a low temperature thermal storage material flows can be pinpointed, since the heat transfer tube arrange | positioned in the low temperature area | region has few problems of corrosion, cheap carbon steel can be used. As a result, by increasing the number of heat transfer tubes and increasing the heat transfer area, the heat transfer efficiency can be improved and the heat exchanger can be made inexpensive and compact.

  Moreover, it is preferable that the heat storage material used for this invention contains the molten salt which consists of eutectic salt of sodium nitrate, sodium nitrite, and potassium nitrate.

  Moreover, it is preferable that the heat transfer tube of the heat exchanger is formed of a finned heat transfer tube with a length set from a portion communicating with the water supply pipe, and the other is formed of a finless heat transfer tube. According to this, since the heat transfer tubes arranged in the region in the container through which the low-temperature heat storage material flows are less susceptible to corrosion, it is possible to employ inexpensive carbon steel finned heat transfer tubes, so the number of heat transfer tubes The heat transfer area can be increased without increasing. Thereby, heat-transfer efficiency can be improved and a heat exchanger can be made cheap and compact. The finned heat transfer tube is preferably arranged in a low temperature setting region where the temperature of the heat storage material in the container is 450 ° C. or lower.

  On the other hand, since the heat transfer tube at a position away from the water supply pipe is disposed in a relatively high temperature region, for example, when the temperature exceeds 450 to 500 ° C., the corrosion of the fin body or fin welded portion of the heat transfer tube with fins easily proceeds. . Therefore, it is not preferable to employ an inexpensive carbon steel finned heat transfer tube in an operating temperature range exceeding 450 to 500 ° C. Therefore, a finless heat transfer tube made of carbon steel is used as the heat transfer tube in this region. Alternatively, the stainless steel containing chromium produces a dense chromium oxide film on the surface, and therefore, the corrosion of the material hardly occurs even in the region of 500 ° C. to 600 ° C., so that it is preferably used for the fin non-heat transfer tube. Thus, according to the present invention, the heat transfer tube with fins and the heat transfer tube without fins are selectively used in the low temperature region and the high temperature region in the container of the heat exchanger. In addition, when austenitic stainless steel finned heat transfer tubes such as SUS304 are used, corrosion durability increases and resistance to thermal shock increases, but there is a problem that costs increase.

  In the present invention, the heat transfer pipe of the heat exchanger includes a plurality of heat transfer pipes that are respectively connected to the steam pipe and the water supply pipe, bent in the container, are formed in a planar shape, and are arranged in parallel. Solid heat storage material with a larger heat capacity and thermal conductivity per volume than the heat storage material in the flow path through which the heat storage material flows between a plurality of heat transfer tubes arranged in a high temperature region in the container where the heat storage material of the tank is put in and out It is preferable to arrange a solid heat storage member formed of According to this, the solid formed with the solid heat storage material in the flow path through which the heat storage material flows around the plurality of heat transfer tubes (for example, the fin non-heat transfer tube group or the bare heat transfer tube group) arranged in the high temperature region. Since the heat storage member is arranged, the flow of the heat storage material having fluidity changes, the heat transfer coefficient in the high temperature region is improved, and the heat exchange efficiency is improved. In other words, the flow path through which the heat storage material having fluidity flows is a gap between the fin non-heat transfer tube groups, and by disposing the solid heat storage member, the flow path is narrowed and a contracted flow is generated, so that The flow rate increases, and the heat transfer coefficient of the fin non-heat transfer tube group increases. Furthermore, the solid heat storage member increases the heat storage density of the heat storage device, and by using a heat storage material with high thermal conductivity, the occurrence of internal stress in the solid heat storage member due to heat transfer is suppressed, making the solid heat storage member less likely to break. A uniform temperature stratification can be formed on the heat storage material in the heat exchanger. As a result, the heat exchanger can be made compact, and the cost can be reduced by using an inexpensive carbon steel finned tube for the heat transfer tube in the low temperature portion.

  ADVANTAGE OF THE INVENTION According to this invention, the compact solar heat storage apparatus suitable for a solar-heat-steam generator can be provided.

It is a block block diagram of Example 1 of the solar thermal storage device of the present invention applied to the solar thermal steam generator of the concentrating solar thermal power plant, and is a diagram for explaining the operation during thermal storage. It is a figure explaining the operation | movement at the time of thermal radiation of the solar thermal energy storage apparatus in FIG. 1 Example. It is a figure which shows the heat exchanger tube arrangement | positioning structure in the heat exchanger container in FIG. 1 Example. It is a figure explaining the flow of the thermal storage material by the solid thermal storage material arrange | positioned in the heat exchanger container in FIG. It is a figure which shows the heat exchanger tube arrangement | positioning structure in the exchanger container of the comparative example 1 for demonstrating the effect of the heat exchanger of this invention. It is a figure which shows the heat exchanger tube arrangement | positioning structure in the exchanger container of the comparative example 2 for demonstrating the effect of the heat exchanger of this invention. It is a figure which shows the heat exchanger tube arrangement | positioning structure in the heat exchanger container of Example 2 of this invention. It is a figure which shows the heat exchanger tube arrangement | positioning structure in the heat exchanger container of Example 3 of this invention.

  Hereinafter, a solar heat storage device of the present invention applied to a solar steam generator of a concentrating solar power plant will be described based on examples.

In FIG. 1, the block block diagram of the solar thermal energy storage apparatus of Example 1 of this invention applied to a solar thermal steam generator is shown. Example 1 is a solar heat storage device applied to a solar heat steam generator of a concentrating solar power plant. The solar steam generator 8 collects and collects the solar radiation 13 of the sun 12 with a mirror or lens (not shown) and generates steam to collect and collect heat with a mirror or lens (not shown). It comprises a superheater 2 that obtains superheated steam, a brackish water separator 3 and a circulation pump 4. The superheated steam generated by the superheater 2 is supplied to a steam turbine power generation system (not shown) via a steam pipe 10 having a steam stop valve 16 to drive the steam turbine to generate power. . The feed water containing the water condensed by driving the steam turbine is returned to the evaporator 1 of the solar heat steam generator 8 by the circulation pump 4a through the feed water pipe 11 having the feed stop valve 15 .

  The solar heat storage device 9 includes a high-temperature heat storage tank 6 as a first heat storage tank for storing a high-temperature heat storage material (molten salt) having fluidity, and a second for storing a low-temperature heat storage material (molten salt) having fluidity. It has a low-temperature heat storage tank 7 as a heat storage tank and a multi-tube heat exchanger 5. The high-temperature heat storage tank 6 is communicated with the container of the heat exchanger 5 through the transfer pipe 6a. A heat storage material stop valve 17a is interposed in the transfer pipe 6a. The low-temperature heat storage tank 7 is communicated with the container of the heat exchanger 5 through the transfer pipe 7a. A heat storage material transfer pump 14 and a heat storage material stop valve 17b are interposed in the transfer pipe 7a.

  The operation at the time of heat storage of the present embodiment configured as described above will be described with reference to FIG. Basically, water is supplied from the water supply pipe 11 to the solar thermal steam generator 8 to generate high-temperature superheated steam. During the day, the amount of superheated steam generated by the solar heat steam generator 8 is set to exceed the required amount of the concentrating solar power plant. In this case, a part of the generated superheated steam is taken out from the steam pipe 10, sent to the heat transfer pipe 21 of the heat exchanger 5 of the heat storage device 9 and stored, and the remaining superheated steam is not shown in the steam turbine. Supplied to the power generation system. In this heat storage process, the heat storage material stored in the low-temperature heat storage tank 7 is circulated into the container (container side) of the heat exchanger 5 by the heat storage material transfer pump 14. The heat storage material is heated by heat exchange between superheated steam (for example, 500 to 550 ° C.) flowing through the heat transfer tube 21 of the heat exchanger 5 and the heat storage material flowing through the container side. The molten salt (for example, 500-550 degreeC) which became high temperature by this is sent to the high temperature thermal storage tank 6, and is stored.

  On the other hand, the superheated steam sent to the heat transfer tube 21 of the heat exchanger 5 is condensed by heat exchange in the process of flowing through the heat transfer tube 21. This condensed water is returned to the evaporator 1 by the circulation pump 4a through the water supply pipe 11 by the circulation pump 4b. When the heat storage mode continues, for example, when the low-temperature heat storage tank 7 becomes empty, the heat storage material stop valves 17a and 17b are closed, the heat storage material transfer pump 14 and the circulation pump 4b are stopped, and the heat storage mode is ended. To do.

Next, with reference to FIG. 2, the operation example at the time of thermal radiation of the thermal storage apparatus 9 is shown. The solar heat steam generator 8 stops the solar heat steam generator 8 because there is no superheated steam output at night when there is no solar radiation as a heat source . Then, the heat radiation from the heat storage device 9 to generate superheated steam continues to perform power generation by driving the condensing type solar thermal power plant. In this heat radiation process, the water supply stop valve 15 and the steam stop valve 16 are closed to stop the water supply supplied to the heat collecting device 8. And while circulating the high temperature (for example, 500-550 degreeC) thermal storage material stored in the high temperature thermal storage tank 7 to the container side of the heat exchanger 5, the circulation pump 4b is driven and the heat exchanger tube 21 of the heat exchanger 5 is supplied. Circulate water supply. Thereby, in the heat exchanger 5, the feed water flowing through the heat transfer tube 21 is heated by the high-temperature heat storage material that flows through the container side, and superheated steam (for example, 500 to 550 ° C.) is generated by heat exchange. The generated superheated steam is supplied to the steam pipe 10 and supplied to a steam turbine power generation system of a concentrating solar power generation plant (not shown). The heat storage material after the heat exchange is sent to the low-temperature heat storage tank 7 and stored. When the high-temperature heat storage tank 6 becomes empty, the heat storage material stop valves 17a and 17b are closed, the heat storage material transfer pump 14 is stopped, and the circulation pump 4b is also stopped.

  With reference to FIG. 3, the detailed structure of the heat exchanger 5 and the operation | movement at the time of thermal storage are demonstrated. In FIG. 3, (a) shows the arrangement of the heat transfer tubes 21 viewed from the front, and (b) shows the arrangement of the heat transfer tubes 21 viewed from the side. As shown in the figure, the heat exchanger 5 of the present embodiment has a plurality of heat transfer tubes 21 through which water supply or steam flows. That is, each heat transfer tube 21 is connected to the steam pipe 10 and the water supply pipe 11, respectively. The heat transfer tubes 21 are respectively connected to the steam pipe 10 and the water supply pipe 11, bent in the container 19, formed in a planar shape, and arranged in parallel.

  On the other hand, the transfer pipe 6 a that transfers the heat storage material of the high-temperature heat storage tank 6 into the container 19 of the heat exchanger 5 is connected to a plurality of high-temperature heat storage material nozzles 29 arranged in the lower part of the container 19. That is, the plurality of high-temperature heat storage material nozzles 29 are coupled to the tube group of the heat transfer tubes 21 with a header structure such as a header. On the other hand, the transfer pipe 7 a for transferring the heat storage material from the container 19 of the heat exchanger 5 to the low-temperature heat storage tank 7 is connected to a plurality of low-temperature heat storage material nozzles 30 arranged at the upper part of the container 19. The plurality of low-temperature heat storage material nozzles 30 are coupled to the tube group of the heat transfer tubes 21 with a header structure such as a header. That is, the heat exchanger 5 is a multi-tube heat connected to the container 19 so that the heat storage material is counterflowed with respect to the flow of steam (water supply during heat dissipation) flowing through the heat transfer tube 21. It constitutes an exchange.

  Each heat transfer tube 21 is formed of a finned heat transfer tube in which a fin 20 is wound around a portion having a length set from a portion communicating with the water supply pipe 10. The region where the finned heat transfer tubes are arranged is a low temperature region B in the container 19 in which a heat storage material is put in and out of the low temperature heat storage tank 7. The heat transfer tubes 21 arranged in the other region, that is, the high temperature region A in the container 19 in which the heat storage material of the high temperature heat storage tank 6 is put in and out are formed of finless heat transfer tubes.

  Furthermore, as shown in FIG. 3, the heat storage material between the plurality of heat transfer tubes 21 arranged in the high temperature region A in the container 19 through which the heat storage material of the high temperature heat storage tank 6 enters and exits is positioned. A plurality of round bar-shaped solid heat storage members 24 formed of a solid heat storage material having a larger heat capacity and thermal conductivity per volume than the heat storage material are arranged.

  Here, the finned heat transfer tube and the finless heat transfer tube need not be made of the same material. For example, a part is made of austenitic stainless steel such as SUS304, and the other part is made of carbon steel such as STB340. Also good. Further, all may be austenitic stainless steel. The fins 20 do not have to be made of the same material as that of the heat transfer tube 21. For example, a ferrite steel fin 20 containing 0.11 wt% or more of chromium may be attached to an austenitic stainless steel heat transfer tube. Moreover, you may attach the fin 21 of the ferritic steel and austenitic stainless steel which contain 0.11 wt% or more of chromium to the heat transfer tube 21 of carbon steel. Furthermore, although it is preferable that the fin 20 winds and welds a plate, it does not need to be wound.

  During heat storage, superheated steam flows from the steam pipe 10 into the heat transfer pipe 21, and heat storage material flows into the container 19 from the low-temperature heat storage tank 7. As a result, the superheated steam that has flowed into the heat transfer pipe 21 is deprived of heat by the heat storage material, condenses and flows out to the water supply pipe 11, and the heat storage material that has reached a high temperature flows out to the high temperature heat storage tank 6. During heat dissipation, the flow of water supply and heat storage material is reversed from that during heat storage. Moreover, as shown to Fig.3 (a), the high temperature thermal storage material nozzle 29 and the low temperature thermal storage material nozzle 30 which were provided with multiple across the width direction of the heat exchanger 5 have the characteristic that heat conductivity is low and it is hard to flow. The heat storage material is made to flow uniformly, and a temperature difference is hardly generated over the width direction of the heat exchanger 5.

  Furthermore, in the first embodiment, the solid heat storage member 24 with good thermal conductivity is arranged in the tube group gap of the heat transfer tube 21. In the present embodiment, the solid heat storage members 24 are arranged in the same row in the gaps between the heat transfer tubes 21 arranged in the same row (inline). Thereby, the heat exchanger tube 21 and the solid heat storage member 24 are arrange | positioned in zigzag form as a whole. Thereby, the temperature difference over the width direction of the heat exchanger 5 hardly occurs, and the heat exchange efficiency can be improved. Thus, the heat storage performance and heat exchange performance of the heat storage device 9 are improved by disposing the solid heat storage member 24 in the container 19 of the heat exchanger 5 as well. The solid heat storage member 24 is preferably formed in a round bar shape, for example, using a material that satisfies the properties of having a larger amount of heat storage per volume than the heat storage material made of molten salt and having a higher thermal conductivity than the heat storage material. For example, pulverized minerals such as bauxite, corundum, and rhododendron, and materials such as magnesia clinker and alumina clinker are suitable.

  Here, the flow of the heat storage material in the container 19 when the solid heat storage member 24 is arranged will be described with reference to FIGS. FIG. 5B shows the heat storage material flow 25 when the solid heat storage member 24 is not disposed. On the other hand, the same figure (a) has shown the flow 25 of the thermal storage material when the solid thermal storage member 24 of a present Example is arrange | positioned. As is apparent from these drawings, by arranging the solid heat storage member 24 between the heat transfer tubes 21, a vortex is generated in the flow 25 of the heat storage material. Mixing of the heat storage material is promoted by this eddy current, and the heat transfer coefficient between the heat storage material and water or steam in the heat transfer tube 21 can be improved.

  Here, the effect of the heat exchanger 5 of the present embodiment will be described in comparison with Comparative Examples 1 and 2 shown in FIGS. The comparative example 1 of FIG. 5 shows the example of the heat exchanger whose steam conditions are about 300 degreeC. A finned tube in which the fins 20 are attached to the outside of the heat transfer tube 21 is used. If it is about 300 degreeC, since cheap carbon steel can be used for the heat exchanger tube 21, and a pipe with a fin can be used, it increases heat transfer area, improves heat transfer efficiency, and makes a heat exchanger cheap and compact. be able to. However, the nitrate-based molten salt heat storage material as in Example 1 has strong oxidizability, and carbon steel becomes severely corroded at 500 ° C. or higher. In particular, corrosion of the fin body of the finned tube and the welded portion of the fin tube is likely to proceed, and an inexpensive carbon steel finned tube cannot be employed at an operating temperature exceeding 500 ° C. On the other hand, in stainless steel containing chromium, a dense chromium oxide film is formed on the surface, so that the corrosion of the material hardly progresses even at 500 ° C to 600 ° C. Further, when an austenitic stainless steel finned tube such as SUS304 is used, corrosion durability increases and resistance to thermal shock increases, but there is a problem that costs increase.

  The comparative example 2 of FIG. 6 shows the example of a heat exchanger in case steam conditions are 500-550 degreeC. A finned tube is employed in the low temperature region B from the inlet / outlet of the heat transfer tube 21 through which the feed water, which is the coldest fluid in the container 19, flows. On the other hand, a finless tube (bare tube) is used in the low temperature region A from the inlet / outlet of the heat transfer tube 21 through which steam, which is the hottest fluid in the container 19, flows. According to the comparative example 2, since the fin effect cannot be obtained, the number of members in the high temperature region of the heat transfer tube 21 is significantly increased. Therefore, there is a problem that the heat exchanger 5 of the heat storage device 9 is enlarged.

  In the present Example 1, although the example arrange | positioned and divided | segmented into the area | region of the finned heat exchanger tube and the fin non-heat exchanger tube inside the container 19 of the heat exchanger 5 was shown, this invention is not limited to this. That is, the heat exchanger 5 may be divided and formed in accordance with the areas of the finned heat transfer tubes and the finless heat transfer tubes, and these heat exchangers may be connected in series.

  Moreover, since the heat exchanger 5 according to the present invention is based on forced convection, there is no directionality regarding gravity with respect to the installation of the heat exchanger 5. Therefore, a heat transfer tube group consisting of finless tubes is arranged in a region where a high temperature fluid enters and exits the heat transfer tube 21, and a heat transfer tube group consisting of finned tubes is arranged in a region where a low temperature fluid enters and exits the heat transfer tube 21, A plurality of solid heat storage members 24 may be arranged in the finless tube group region.

  With reference to FIG. 7, Example 2 of the heat exchanger of this invention is demonstrated. In Example 1, although the example which arrange | positioned the several heat exchanger tube 21 in parallel was shown, in this Example 2, it is the example arrange | positioned by staggering the position of the adjacent heat exchanger tube 21 alternately. In accordance with this, the solid heat storage members 24 are also arranged in a staggered manner. Moreover, the shape of the solid heat storage member 24 is the same cylindrical shape as the heat transfer tube 21, and the length is preferably about the width of the container of the heat exchanger 5, and the dimensions can be adjusted as appropriate.

  With reference to FIG. 8, Example 3 of the heat exchanger of this invention is demonstrated. In this embodiment, instead of the solid heat storage member 24 of the first embodiment, a solid heat storage material enclosing tube 27 enclosing a solid heat storage material is disposed. Since the heat storage material is enclosed in the pipe, it is not necessary to mold the heat storage material. As a result, a powder or liquid heat storage material can be used. Further, when the heat storage material made of molten salt and the solid heat storage member 24 are in direct contact as in the first embodiment, the flow rate of the heat storage material in the vicinity of the solid heat storage member 24 is increased, and erosion may occur. . Thereby, the solid heat storage member 24 is crushed and scattered in the heat storage material, which affects the operation of the devices such as the heat storage material transfer pump 14 and the heat storage material stop valves 17a and 17b. In this regard, as in the third embodiment, the erosion problem can be solved by causing the solid heat storage material and the solid heat storage material to contact each other indirectly using the solid heat storage material enclosing tube 27.

  As described above, the present invention has been described based on the embodiments, but the present invention is not limited thereto, and can be implemented in a form that is modified or changed within the scope of the gist of the present invention. It will be apparent to those skilled in the art that such variations or modifications are within the scope of the claims.

DESCRIPTION OF SYMBOLS 1 Evaporator 2 Superheater 3 Brackish water separator 4a, 4b Circulation pump 5 Heat exchanger 6 High temperature thermal storage tank 7 Low temperature thermal storage tank 8 Solar thermal steam generator 9 Thermal storage apparatus 10 Steam piping 11 Feed water piping 14 Thermal storage material transfer pump 19 Container 20 Fin 21 Heat Transfer Tube 24 Solid Heat Storage Member 27 Solid Heat Storage Material Enclosed Tube 29 High Temperature Storage Material Nozzle 30 Low Temperature Heat Storage Material Nozzle A Low Temperature Region B High Temperature Region

Claims (6)

A heat transfer pipe formed by connecting a steam pipe for supplying steam generated by a solar heat steam generator to a supply destination and a water supply pipe for supplying water for steam to the solar steam generator is housed in a container. Heat exchanger,
A first heat storage tank communicating with the heat exchanger and storing a fluid heat storage material;
A second heat storage tank communicating with the heat exchanger container and storing the heat storage material;
E Bei a heat storage material transfer pump for transferring the heat storage material to each other via the heat exchanger between said second thermal storage tank and said first heat-storage tank,
The heat transfer tube of the heat exchanger includes a plurality of heat transfer tubes that are bent in the container and formed in a planar shape and arranged in parallel.
The heat capacity per volume than the heat storage material in the flow path through which the heat storage material between a plurality of the heat transfer tubes arranged in a high temperature region in the container into and out of the heat storage material of the first heat storage tank. And a solar heat storage device comprising a solid heat storage member formed of a solid heat storage material having a high thermal conductivity .   2. The solar heat storage device according to claim 1, wherein the heat storage material includes a molten salt made of a eutectic salt of sodium nitrate, sodium nitrite, and potassium nitrate.   The heat transfer tube of the heat exchanger is formed of a finned heat transfer tube with a length set from a portion in the container communicated with the water supply pipe, and the other is formed of a fin non-heat transfer tube. The solar thermal energy storage device according to claim 1 or 2, wherein   The solar heat storage device according to claim 3, wherein the finned heat transfer tube is disposed in a low temperature setting region in which the temperature of the heat storage material in the container is 450 ° C or lower. The solar heat steam generator, one of the claims 1 to 4, characterized by being formed so as to deliver from the water supply to the steam pipe and generate steam superheated by solar radiation of the sun from the water supply pipe The solar heat storage apparatus of Claim 1. The heat storage material transfer pump transfers the heat storage material of the second heat storage tank to the first heat storage tank via the heat transfer pipe of the heat exchanger in a heat storage operation mode,
Of claims 1 to 5, characterized in that it is configured so that the heat storage material of the first thermal storage tank in the radiating operation mode through the heat transfer tube of the heat exchanger is transferred to the second thermal storage tank The solar heat storage apparatus of any one of Claims.

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