WO2017217390A1 - Molten salt-type heat medium, method for using molten salt-type heat medium and solar heat utilization system - Google Patents

Molten salt-type heat medium, method for using molten salt-type heat medium and solar heat utilization system Download PDF

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WO2017217390A1
WO2017217390A1 PCT/JP2017/021742 JP2017021742W WO2017217390A1 WO 2017217390 A1 WO2017217390 A1 WO 2017217390A1 JP 2017021742 W JP2017021742 W JP 2017021742W WO 2017217390 A1 WO2017217390 A1 WO 2017217390A1
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molten salt
heat medium
carbonate
heat
type heat
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PCT/JP2017/021742
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French (fr)
Japanese (ja)
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善太郎 椿
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綜研テクニックス株式会社
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    • C—CHEMISTRY; METALLURGY
    • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
    • C09K—MATERIALS FOR MISCELLANEOUS APPLICATIONS, NOT PROVIDED FOR ELSEWHERE
    • C09K5/00—Heat-transfer, heat-exchange or heat-storage materials, e.g. refrigerants; Materials for the production of heat or cold by chemical reactions other than by combustion
    • C09K5/02—Materials undergoing a change of physical state when used
    • C09K5/06—Materials undergoing a change of physical state when used the change of state being from liquid to solid or vice versa
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
    • F01K—STEAM ENGINE PLANTS; STEAM ACCUMULATORS; ENGINE PLANTS NOT OTHERWISE PROVIDED FOR; ENGINES USING SPECIAL WORKING FLUIDS OR CYCLES
    • F01K25/00—Plants or engines characterised by use of special working fluids, not otherwise provided for; Plants operating in closed cycles and not otherwise provided for
    • F01K25/08—Plants or engines characterised by use of special working fluids, not otherwise provided for; Plants operating in closed cycles and not otherwise provided for using special vapours
    • F01K25/10—Plants or engines characterised by use of special working fluids, not otherwise provided for; Plants operating in closed cycles and not otherwise provided for using special vapours the vapours being cold, e.g. ammonia, carbon dioxide, ether
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F03—MACHINES OR ENGINES FOR LIQUIDS; WIND, SPRING, OR WEIGHT MOTORS; PRODUCING MECHANICAL POWER OR A REACTIVE PROPULSIVE THRUST, NOT OTHERWISE PROVIDED FOR
    • F03G—SPRING, WEIGHT, INERTIA OR LIKE MOTORS; MECHANICAL-POWER PRODUCING DEVICES OR MECHANISMS, NOT OTHERWISE PROVIDED FOR OR USING ENERGY SOURCES NOT OTHERWISE PROVIDED FOR
    • F03G6/00—Devices for producing mechanical power from solar energy
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F24—HEATING; RANGES; VENTILATING
    • F24S—SOLAR HEAT COLLECTORS; SOLAR HEAT SYSTEMS
    • F24S90/00—Solar heat systems not otherwise provided for
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
    • Y02E10/00—Energy generation through renewable energy sources
    • Y02E10/40—Solar thermal energy, e.g. solar towers
    • Y02E10/46—Conversion of thermal power into mechanical power, e.g. Rankine, Stirling or solar thermal engines

Definitions

  • the present invention relates to a molten salt type heat medium, a method of using the molten salt type heat medium, and a solar heat utilization system.
  • the solar thermal power generation system is said to be capable of generating heat of about 1000 ° C. by sunlight, and it is required to increase the power generation efficiency of the solar thermal power generation system by increasing the steam temperature accordingly. ing.
  • a hydrogen production system using solar heat is also known, but a high-temperature process exceeding 650 ° C. may be required for the hydrothermal decomposition reaction, and a method of directly heating the reaction tank with solar heat or the like is used. Yes.
  • the method of directly heating the reaction tank it is difficult to control the reaction temperature, and in order to control the reaction temperature more easily and stably, it is required to heat with a heat-resistant heat medium.
  • a carbonate type heat medium containing sodium carbonate, lithium carbonate and calcium carbonate is known.
  • Patent Document 1 describes the use of carbonate as a heat storage material for photovoltaic power generation.
  • Patent Document 2 describes the use of carbonate as an electrolyte for fuel cells.
  • neither of Patent Documents 1 and 2 reports the use of carbonate as a heat medium. Therefore, the present inventor has focused on this carbonate, and as a result of intensive research in pursuit of a low melting point, has led to the present invention.
  • an object of the present invention is to provide a molten salt type heat medium having a low melting point and a relatively high heat resistance temperature, a method for using the molten salt type heat medium, and a solar heat utilization system using the molten salt type heat medium. Is to provide.
  • the molten salt type heat medium includes 10 to 30 mole percent potassium carbonate, 13 to 35 mole percent sodium carbonate, 20 to 40 mole percent Less than or equal to lithium carbonate, 1.5 to 15 mole percent calcium carbonate, 5 to 20 mole percent barium carbonate, and a total of 0.2 to 35 mole percent magnesium carbonate And / or cesium carbonate, and a carbonate mixture containing the cesium carbonate.
  • the method of using the molten salt type heat medium according to another embodiment of the present invention is 10 mol percent or more and 30 mol percent or less of potassium carbonate, 13 mol percent or more and 35 mol percent or less of sodium carbonate, and 20 mol percent. More than 40 mol% lithium carbonate, 1.5 mol% to 15 mol% calcium carbonate, 5 mol% to 20 mol% barium carbonate, and 0.2 mol% to 35 mol% in total
  • a solar heat utilization system includes 10 to 30 mole percent potassium carbonate, 13 to 35 mole percent sodium carbonate, and 20 to 40 mole percent.
  • the heat use part to be used and the heated molten salt type heat medium to the heat use part To feed it characterized a conduit in fluid communication with and the solar heating unit and the heat using unit, further comprising.
  • the molten salt type heat medium of the present invention has a low melting point and a relatively high heat resistance temperature. For this reason, the molten salt type heat medium of the present invention, for example, can reduce the size of the equipment by omitting a large preheating process for a solar thermal power generation system and can increase the power generation efficiency, and can increase the temperature such as hydrogen production. It can also be applied to required processes.
  • FIG. 1 is an overall schematic diagram of a solar heat utilization system using a molten salt type heat medium according to an embodiment of the present invention. It is the elements on larger scale which expanded the condensing element of the solar thermal utilization system of FIG.
  • FIG. 3 is a graph in which a weight reduction rate of a molten salt type heat medium according to an embodiment of the present invention is plotted with respect to a heating temperature, and illustrates a definition of a heat resistant temperature Th of the molten salt type heat medium.
  • FIG. 1 is an overall schematic diagram of a solar heat utilization system 1 using a molten salt type heat medium 10
  • FIG. 2 is a partially enlarged view in which the condensing element 110 of the solar heat utilization system 1 in FIG. 1 is enlarged.
  • each component ratio of the component of the molten salt type heat medium 10 is shown by mole percentage.
  • each component ratio of the molten salt type heat medium 10 represents the number of moles of each component with respect to the total number of moles of all the components of the molten salt type heat medium 10 as a percentage.
  • the number of moles of each component) ⁇ 100 / (total number of moles of all components of the molten salt type heat medium 10) [mole percent].
  • fluid communication means that the same fluid is connected so that it can flow, and includes both cases of direct connection and indirect connection. .
  • the molten salt type heat medium 10 can be utilized for various uses which need to take out heat from a heat source not only in it, for example, thermal power It can also be used for power generation systems.
  • the molten salt type heat medium 10 which concerns on embodiment of this invention is demonstrated.
  • the molten salt type heat medium 10 heats or cools an object in a heat use unit 300 including a power generation device such as thermal power generation and solar thermal power generation, a reaction device that produces hydrogen by hydrothermal decomposition reaction, and the like. In order to achieve the target temperature, it is used to transfer heat between the heating unit 100 and the heat using unit 300 of the molten salt heat medium 10.
  • a gas generation product for rotating a gas turbine such as steam or combustion gas
  • a reaction device for producing hydrogen a reaction object such as water vapor or a metal oxide is an object. It becomes a thing.
  • the molten salt type heat medium 10 includes at least 10 mole percent to 30 mole percent potassium carbonate (K 2 CO 3 ), 13 mole percent to 35 mole percent sodium carbonate (Na 2 CO 3 ), and 20 moles. Lithium carbonate (Li 2 CO 3 ) of not less than 40 percent and not more than 15 mol, calcium carbonate (CaCO 3 ) of not less than 1.5 and not more than 15 mol percent, and barium carbonate (BaCO 3 ) of not less than 5 and not more than 20 mol percent. ) And a total of 0.2 mole percent to 35 mole percent magnesium carbonate (MgCO 3 ) and / or cesium carbonate (Cs 2 CO 3 ).
  • the molten salt type heat medium 10 is a heat medium of at least 6 or 7 component system containing magnesium carbonate and / or cesium carbonate in addition to the above 5 components. According to this, since the molten salt type heat medium 10 can have a low melting point and a relatively high heat resistance, a large preheating element for the molten salt type heat medium 10 is not required, And the heat exchange efficiency between the heating part 100 of the molten salt type heat medium 10 and the heat
  • the molten salt type heat medium 10 has a low melting point Tm and a high heat resistant temperature Th, and therefore has a wide temperature range that can be normally used. Therefore, the molten salt type heat medium 10 does not require a large preheating element of the heat medium, and can reduce the size of the facility and reduce the amount of the heat medium used. In addition, since the molten salt heat medium 10 has a relatively low viscosity, it can smoothly flow through the pipe 410. Moreover, it can be said that it has excellent physical properties as a heat medium in that it does not contain a metal halide-based molten salt such as a metal chloride or has a small content, so that corrosion of equipment can be suppressed.
  • a metal halide-based molten salt such as a metal chloride or has a small content
  • the "heat-resistant temperature” in the present invention refers to a temperature at which a weight reduction of 1% by weight is recognized from the sample weight at 550 ° C. after the molten salt type heat medium is heated and melted.
  • the “melting point” in the present invention means an endotherm when a molten salt type heat medium is completely heated and melted, once cooled and solidified, and then heated again at a constant rate. It shall refer to the temperature at the peak.
  • the molten salt heat medium 10 may include a carbonate mixture containing both magnesium carbonate and cesium carbonate as essential components in addition to the above-mentioned five previous components. That is, the molten salt heat medium 10 is at least a seven-component molten salt heat medium containing magnesium carbonate and cesium carbonate as essential components, thereby greatly reducing the melting point Tm of the molten salt heat medium 10.
  • the temperature range that can be normally used can be expanded.
  • the molten salt type heat medium 10 includes a carbonate mixture containing both magnesium carbonate and cesium carbonate as essential components in addition to the previous five components
  • the molten salt type heat medium 10 includes a carbonate mixture containing magnesium carbonate and cesium carbonate as essential components in addition to the foregoing five components
  • the magnesium carbonate is contained in an amount of 1.0 to 25 mole percent.
  • cesium carbonate is contained in an amount of 0.5 mole percent to 20 mole percent.
  • the molten salt type heat medium 10 has a melting point Tm as compared with a system containing only either magnesium carbonate or cesium carbonate. And the heat resistant temperature Th can be made suitable.
  • the molten salt type heat medium 10 may contain other components other than potassium carbonate, sodium carbonate, lithium carbonate, barium carbonate, calcium carbonate, magnesium carbonate, and / or cesium carbonate.
  • Other components of the molten salt heat medium 10 include alkali metal or alkaline earth metal carbonates other than the above, such as strontium carbonate (SrCO 3 ), nitrates, sulfates, acetates of alkali metals or alkaline earth metals And phosphates, alkali metal or alkaline earth metal halides, and other molten salts.
  • the content of the other components contained in the molten salt heat medium 10 is greater than 0 mole percent and not greater than 20 mole percent, preferably greater than 0 mole percent and not greater than 10 mole percent, more preferably 0 mole. Greater than percent and less than or equal to 5 mole percent.
  • the content of the metal halide contained in the molten salt type heat medium 10 is changed from that of the molten salt type heat medium 10 due to the necessity of preventing the corrosion of the equipment.
  • the total amount of 100 mole percent it is preferably 0.1 mole percent or less, more preferably 0.05 mole percent or less, and still more preferably not blended at all.
  • each carbonate contained in the molten salt type heat medium 10 may exist separately in the molten salt type heat medium 10, a plurality of types of carbonates are combined to form, for example, sodium potassium carbonate. It may exist as a carbonate containing a plurality of metal ions such as sodium and potassium such as (NaKCO 3 ).
  • the molten salt type heat medium which concerns on embodiment of this invention does not require the large-scale preheating element for a heat medium, for example in a solar thermal power generation system, size reduction of an installation, and use of a heat medium The amount can be reduced. Moreover, the power generation efficiency of the solar thermal power generation system can be increased, and it can also be applied to heating reactors that require high-temperature processes such as hydrogen production.
  • the solar heat utilization system 1 uses a molten salt type heat medium 10, and includes a molten salt type heat medium 10, a solar heating unit 100 that heats the molten salt type heat medium 10 with sunlight, and a molten salt type heat medium.
  • the solar heating part 100 and the heat using part 300 are in fluid communication.
  • the solar heating unit 100 may include a condensing element 110, and the condensing element 110 may include a condenser tube 112 and a condenser mirror 114 through which the molten salt heat medium 10 passes.
  • the light collecting element 110 may be a trough-type light collecting device in which a plurality of curved reflecting mirrors are arranged along a plurality of light collecting tubes 112 arranged in parallel. It may be a Fresnel type, a dish type, or other known light collecting device.
  • the condensing element 110 may include components (not shown) such as a heliostat as necessary.
  • the solar heat utilization system 1 may further include at least one of the heat medium containers 210, 220, and 230 that are in fluid communication with the pipe line 410. That is, the heat medium containers 210, 220, and 230 are containers that temporarily store the molten salt heat medium 10 temporarily.
  • the heat medium containers 210, 220, and 230 are provided with the high temperature heat medium tank 210 that can store the high temperature molten salt heat medium 10 heated by the solar heating unit 100 and the heat using unit 300 after supplying heat. They are a low-temperature heat medium container 220 that can store a low-temperature molten salt heat medium 10 and an expansion tank 230 for the molten salt heat medium 10.
  • the heat medium containers 210, 220, and 230 may be configured to seal the molten salt type heat medium 10 with carbon dioxide by being filled with the molten salt type heat medium 10 and carbon dioxide. According to this, the heat resistance of the molten salt heat medium 10 can be further improved, and the practical heat resistant temperature can be increased to about 1000 ° C. In addition, the liquid containing the molten salt type heat medium 10 can be put in the heat medium containers 210, 220, and 230, and the empty area can be filled with only carbon dioxide.
  • the heat use unit 300 is not particularly limited as long as it uses solar heat, and may include a heat use element 310 such as a power generation device including a gas turbine and a reaction device that produces hydrogen by a hydrothermal decomposition reaction.
  • a gas turbine include a steam turbine and a combustion gas turbine.
  • the hydrothermal decomposition reaction a two-stage hydrothermal decomposition reaction using a metal oxide such as iron oxide or cerium oxide is exemplified.
  • the two-stage hydrothermal decomposition reaction includes an oxygen generation reaction in which oxygen is released from a metal oxide at a high temperature of 650 ° C. or higher in a low oxygen partial pressure gas atmosphere such as nitrogen, and a 650 ° C. is applied to the metal oxide after releasing oxygen. This is performed by alternately repeating two reactions of hydrogen generation reaction in which water vapor (H 2 O) is brought into contact with each other at a low temperature to generate hydrogen.
  • water vapor H 2 O
  • the heat using unit 300 may further include a cooling element 320 that cools a heat medium different from the molten salt type heat medium 10 described later, after the heat using element 310.
  • the molten salt type heat medium 10 supplied from the pipe line 410 may be directly circulated.
  • the heat use part 300 further includes a heat exchanger 330, and in the heat use part 300, Further, another heat medium different from the molten salt type heat medium 10 that has exchanged heat with the molten salt type heat medium 10 may be circulated.
  • the pipe line 410 is in fluid communication with the piping of the solar heating unit 100 such as the condenser tube 112 and the piping of the heat using unit 300, for example, and the molten salt type heat medium 10 is connected to the solar heating unit 100 and the heat using unit 300. Circulate between. For this reason, the pipe line 410 may be provided with one or more pumps 420 and one or more valves 461 and 462.
  • the solar heat utilization system 1 may further include a heat storage unit (not shown) in order to stabilize the solar heat utilization efficiency of the solar heat utilization system 1. That is, the solar heat utilization system 1 may store solar heat in the heat storage unit during daytime or when the weather is good, and take out solar heat from the heat storage unit and use it at night or when the weather is bad.
  • the sunlight utilization system which concerns on embodiment of this invention can make a sunlight utilization system more efficient by using the molten salt type heat medium 10 with high heat resistance.
  • the solar power utilization system can be improved in efficiency because power generation efficiency can be increased and a heat medium can be used for a process requiring high temperature such as hydrogen production.
  • the use of the molten salt heat medium 10 has a wide temperature range that can be normally used, it is possible to reduce the size of the equipment and reduce the operation cost.
  • the molten salt heat medium 10 can be used by, for example, heating the molten salt heat medium 10 with sunlight in the solar heating unit 100 and using a pipe 410 in fluid communication with the solar heating unit 100. Supplying the mold heat medium 10 to the heat using unit 300, and using the heat provided by the molten salt type heat medium 10 in the heat using unit 300.
  • the sunlight collected by the light collecting element 110 is converted into heat in the solar light heating unit 100, and the molten salt heat medium 10 is heated.
  • the molten salt heat medium 10 transfers solar heat from the solar heating part 100 to the heat using part 300, and uses the solar heat in the heat using part 300 to perform hydrogen generation by power generation or hydrothermal decomposition reaction. .
  • the method of using the molten salt type heat medium 10 may further include a storage step of the molten salt type heat medium 10.
  • the molten salt type heat medium 10 is supplied to the heat medium containers 210, 220, 230, and the molten salt type heat medium 10 is stored in the heat medium containers 210, 220, 230. It is.
  • a carbon dioxide filling step of filling the heat medium containers 210, 220, and 230 with carbon dioxide may be included before or after the storage step of the molten salt heat medium 10.
  • the inside of the heat medium container 210, 220, 230 can be a carbon dioxide atmosphere, the reduction of the heated molten salt type heat medium 10 can be suppressed in the heat medium container 210, 220, 230. . In this way, the heat resistance of the molten salt heat medium 10 can be further improved.
  • the method for using the molten salt type heat medium 10 further includes a step of supplying the molten salt type heat medium 10 to the solar heating unit 100, and the molten salt type heat medium 10 is circulated in the solar heat utilization system 1 for use. It is preferable. In this case, maintenance such as replacement of the molten salt heat medium 10 is required as the molten salt heat medium 10 deteriorates.
  • the usage method of the molten salt type heat medium 10 which concerns on embodiment of this invention demonstrated using the solar-heat utilization system 1, it is not limited to this, You may use in a thermal power generation system etc. In this case, the solar heating unit 100 is replaced with a heating unit 100a including a heating medium heater such as a heating medium boiler (not shown).
  • Examples 1, 2, and 3 A method for preparing a molten salt heat medium according to Examples 1, 2, and 3 will be described.
  • potassium carbonate, lithium carbonate, sodium carbonate, calcium carbonate, barium carbonate, and magnesium carbonate were mixed at a ratio described in the component column of Examples 1 and 2 in Table 1.
  • the carbonate mixture was pulverized for 1 hour in an automatic mortar and then dehydrated by heating at 300 ° C. for 2 hours using a dryer.
  • the mixture was uniformly mixed for 5 minutes by a rocking mill at the ratio described in the component column of Examples 1, 2, and 3 in Table 1, and used as the molten salt type heat medium according to Examples 1, 2, and 3.
  • the molten salt type heat medium according to Examples 4, 5, and 6 includes potassium carbonate, lithium carbonate, sodium carbonate, calcium carbonate, barium carbonate, and cesium carbonate in the component columns of Examples 4, 5, and 6 in Table 1.
  • the molten salt type heat medium according to Example 7-15 includes potassium carbonate, lithium carbonate, sodium carbonate, calcium carbonate, barium carbonate, magnesium carbonate, and cesium carbonate in the column of Example 7-15 in Table 1.
  • Comparative Example 1 The molten salt type heat medium according to Comparative Example 1 used a nitrate mixture in which potassium carbonate, lithium carbonate, sodium carbonate, calcium carbonate, and barium carbonate were mixed at a ratio described in the component column of Comparative Example 1 in Table 1. Except for the above, samples prepared in the same manner as the molten salt type heat medium according to Examples 1, 2, and 3 were used as the molten salt type heat medium of Comparative Example 1.
  • TG / DTA differential thermothermal gravimetric simultaneous measurement apparatus
  • the heat resistance temperature of the molten salt type heat medium of the present invention is higher than that of the molten salt type heat medium composed of potassium carbonate, sodium carbonate, lithium carbonate, calcium carbonate, and barium carbonate in Comparative Example 1. Although equivalent, the melting point was significantly lower.
  • the molten salt type heat mediums of Examples 1 to 15 had a melting point of 360 ° C. or less across the board and reduced in weight even when it exceeded 650 ° C. It was difficult to proceed.
  • the numerical value shown in Table 1 and FIG. 3 is a measured value in a carbon dioxide atmosphere.
  • the molten salt type heat medium of this example had a viscosity sufficiently low to pass through the pipe line 410 and the like.

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Abstract

[Problem] The purpose of the present invention is to provide: a molten salt-type heat medium which has a high heat resistance temperature and is usable in a wide temperature range; a method for using a molten salt-type heat medium; and a solar heat utilization system which uses a molten salt-type heat medium. [Solution] A molten salt-type heat medium according to the present invention comprises a carbonate mixture that contains from 10 mol% to 30 mol% (inclusive) of potassium carbonate, from 13 mol% to 35 mol% (inclusive) of sodium carbonate, from 20 mol% to 40 mol% (inclusive) of lithium carbonate, from 1.5 mol% to 15 mol% (inclusive) of calcium carbonate, from 5 mol% to 20 mol% (inclusive) of barium carbonate, and from 0.2 mol% to 35 mol% (inclusive) of magnesium carbonate and/or cesium carbonate in total.

Description

溶融塩型熱媒体、溶融塩型熱媒体の使用方法および太陽熱利用システムMolten salt heat medium, method of using molten salt heat medium, and solar heat utilization system
　本発明は、溶融塩型熱媒体、溶融塩型熱媒体の使用方法および太陽熱利用システムに関する。 The present invention relates to a molten salt type heat medium, a method of using the molten salt type heat medium, and a solar heat utilization system.
　近年、永続的に利用することができる再生可能エネルギーとして、太陽熱エネルギーを利用することが世界的に注目されている。太陽熱エネルギーを利用するものとしては、太陽熱発電システムなどが知られており、高温で使用可能な溶融塩型熱媒体が広く使用されている。 In recent years, the use of solar thermal energy has attracted worldwide attention as a renewable energy that can be used permanently. Solar thermal power generation systems and the like are known as devices using solar thermal energy, and molten salt heat media that can be used at high temperatures are widely used.
　太陽熱発電システムは、太陽光によって約１０００℃程度の熱を発生させることが可能であると言われており、それに応じて蒸気温度を高めることで、太陽熱発電システムの発電効率を高めることが求められている。また、太陽熱を利用した水素製造システムも知られているが、水熱分解反応に６５０℃を超える高温プロセスが必要とされる場合もあり、太陽熱などで反応槽を直接加熱する方法が用いられている。しかしながら、反応槽を直接加熱する方法では、反応温度の制御が難しく、より容易かつ安定的に反応温度を制御するために、高耐熱性の熱媒体によって加熱を行うことが求められている。 The solar thermal power generation system is said to be capable of generating heat of about 1000 ° C. by sunlight, and it is required to increase the power generation efficiency of the solar thermal power generation system by increasing the steam temperature accordingly. ing. A hydrogen production system using solar heat is also known, but a high-temperature process exceeding 650 ° C. may be required for the hydrothermal decomposition reaction, and a method of directly heating the reaction tank with solar heat or the like is used. Yes. However, in the method of directly heating the reaction tank, it is difficult to control the reaction temperature, and in order to control the reaction temperature more easily and stably, it is required to heat with a heat-resistant heat medium.
　従来の高耐熱性の溶融塩型熱媒体としては、例えば炭酸ナトリウム、炭酸リチウム及び炭酸カルシウムを含む炭酸塩型熱媒体が知られている。 As a conventional high heat resistant molten salt type heat medium, for example, a carbonate type heat medium containing sodium carbonate, lithium carbonate and calcium carbonate is known.
　しかしながら、昨今の熱媒体には、高い耐熱性に加えて、熱媒体の予熱過程を極力省き、かつ配管内での凝固リスクを軽減する観点で、融点の低さが求められているが、従来の炭酸塩型熱媒体では、特に融点の観点で十分とは言えない場合があった。 However, in recent heat media, in addition to high heat resistance, a low melting point is required from the viewpoint of eliminating the preheating process of the heat medium as much as possible and reducing the risk of solidification in the piping. In the case of the carbonate-type heat medium, it may not be sufficient particularly from the viewpoint of the melting point.
　特許文献１には、炭酸塩を太陽光発電の蓄熱材として使用することが記載されている。また特許文献２には、炭酸塩を燃料電池用電解質として使用することが記載されている。しかしながら、特許文献１及び２のいずれにおいても、炭酸塩を熱媒体として使用することは報告されていない。そこで、本発明者は、この炭酸塩に着目し、特に融点の低さを追求して鋭意研究を行った結果、本発明に至ったものである。 Patent Document 1 describes the use of carbonate as a heat storage material for photovoltaic power generation. Patent Document 2 describes the use of carbonate as an electrolyte for fuel cells. However, neither of Patent Documents 1 and 2 reports the use of carbonate as a heat medium. Therefore, the present inventor has focused on this carbonate, and as a result of intensive research in pursuit of a low melting point, has led to the present invention.
国際公開第２０１２／１３０２８５号International Publication No. 2012/130285 特公平７－５４７１０号公報Japanese Patent Publication No. 7-54710
　従って、本発明の課題は、融点が低く、かつ比較的高い耐熱温度を有する溶融塩型熱媒体、当該溶融塩型熱媒体の使用方法、及び、当該溶融塩型熱媒体を使用した太陽熱利用システムを提供することである。 Accordingly, an object of the present invention is to provide a molten salt type heat medium having a low melting point and a relatively high heat resistance temperature, a method for using the molten salt type heat medium, and a solar heat utilization system using the molten salt type heat medium. Is to provide.
（１）本発明の一実施形態に係る溶融塩型熱媒体は、１０モルパーセント以上３０モルパーセント以下の炭酸カリウムと、１３モルパーセント以上３５モルパーセント以下の炭酸ナトリウムと、２０モルパーセント以上４０モルパーセント以下の炭酸リチウムと、１．５モルパーセント以上１５モルパーセント以下の炭酸カルシウムと、５モルパーセント以上２０モルパーセント以下の炭酸バリウムと、合計で０．２モルパーセント以上３５モルパーセント以下の炭酸マグネシウム及び／又は炭酸セシウムと、を含有する炭酸塩混合物を含むことを特徴とする。 (1) The molten salt type heat medium according to an embodiment of the present invention includes 10 to 30 mole percent potassium carbonate, 13 to 35 mole percent sodium carbonate, 20 to 40 mole percent Less than or equal to lithium carbonate, 1.5 to 15 mole percent calcium carbonate, 5 to 20 mole percent barium carbonate, and a total of 0.2 to 35 mole percent magnesium carbonate And / or cesium carbonate, and a carbonate mixture containing the cesium carbonate.
（２）本発明の他実施形態に係る溶融塩型熱媒体の使用方法は、１０モルパーセント以上３０モルパーセント以下の炭酸カリウムと、１３モルパーセント以上３５モルパーセント以下の炭酸ナトリウムと、２０モルパーセント以上４０モルパーセント以下の炭酸リチウムと、１．５モルパーセント以上１５モルパーセント以下の炭酸カルシウムと、５モルパーセント以上２０モルパーセント以下の炭酸バリウムと、合計で０．２モルパーセント以上３５モルパーセント以下の炭酸マグネシウム及び／又は炭酸セシウムと、を含有する炭酸塩混合物を含む溶融塩型熱媒体を、加熱部において加熱すること、上記加熱部に流体連通する管路によって、上記溶融塩型熱媒体を熱使用部に給送すること、及び、上記熱使用部において、上記溶融塩型熱媒体により供される熱を使用すること、を備えることを特徴とする。 (2) The method of using the molten salt type heat medium according to another embodiment of the present invention is 10 mol percent or more and 30 mol percent or less of potassium carbonate, 13 mol percent or more and 35 mol percent or less of sodium carbonate, and 20 mol percent. More than 40 mol% lithium carbonate, 1.5 mol% to 15 mol% calcium carbonate, 5 mol% to 20 mol% barium carbonate, and 0.2 mol% to 35 mol% in total The molten salt type heat medium containing a carbonate mixture containing magnesium carbonate and / or cesium carbonate is heated in a heating part, and the molten salt type heat medium is supplied by a conduit in fluid communication with the heating part. Feeding to the heat using part, and in the heat using part, the molten salt type heat The use of heat to be supplied by the body, characterized in that it comprises a.
（３）本発明の他実施形態に係る太陽熱利用システムは、１０モルパーセント以上３０モルパーセント以下の炭酸カリウムと、１３モルパーセント以上３５モルパーセント以下の炭酸ナトリウムと、２０モルパーセント以上４０モルパーセント以下の炭酸リチウムと、１．５モルパーセント以上１５モルパーセント以下の炭酸カルシウムと、５モルパーセント以上２０モルパーセント以下の炭酸バリウムと、合計で０．２モルパーセント以上３５モルパーセント以下の炭酸マグネシウム及び／又は炭酸セシウムと、を含有する炭酸塩混合物を含む溶融塩型熱媒体と、上記溶融塩型熱媒体を太陽光によって加熱する太陽光加熱部と、上記溶融塩型熱媒体により供される熱を使用する熱使用部と、加熱された上記溶融塩型熱媒体を上記熱使用部に給送するために、上記太陽光加熱部と上記熱使用部とに流体連通する管路と、備えることを特徴とする。 (3) A solar heat utilization system according to another embodiment of the present invention includes 10 to 30 mole percent potassium carbonate, 13 to 35 mole percent sodium carbonate, and 20 to 40 mole percent. Lithium carbonate, 1.5 to 15 mole percent calcium carbonate, 5 to 20 mole percent barium carbonate, and 0.2 to 35 mole percent magnesium carbonate in total and / or Or a molten salt type heat medium containing a carbonate mixture containing cesium carbonate, a solar heating part for heating the molten salt type heat medium with sunlight, and heat provided by the molten salt type heat medium. The heat use part to be used and the heated molten salt type heat medium to the heat use part To feed, it characterized a conduit in fluid communication with and the solar heating unit and the heat using unit, further comprising.
　本発明の溶融塩型熱媒体は、融点が低く、かつ耐熱温度を比較的高くすることができる。このため、本発明の溶融塩型熱媒体は、例えば、太陽熱発電システムためにおいては大掛かりな予熱過程を省くことで設備を小型化するとともに、発電効率を上げることができ、水素製造などの高温を要するプロセスにも適用することができる。 The molten salt type heat medium of the present invention has a low melting point and a relatively high heat resistance temperature. For this reason, the molten salt type heat medium of the present invention, for example, can reduce the size of the equipment by omitting a large preheating process for a solar thermal power generation system and can increase the power generation efficiency, and can increase the temperature such as hydrogen production. It can also be applied to required processes.
本発明の一実施形態に係る溶融塩型熱媒体を使用した太陽熱利用システムの全体概略図である。1 is an overall schematic diagram of a solar heat utilization system using a molten salt type heat medium according to an embodiment of the present invention. 図１の太陽熱利用システムの集光要素を拡大した部分拡大図である。It is the elements on larger scale which expanded the condensing element of the solar thermal utilization system of FIG. 本発明の一つの実施態様による溶融塩型熱媒体の重量減少率を加熱温度に対してプロットしたグラフであって、溶融塩型熱媒体の耐熱温度Ｔｈの定義を説明するものである。FIG. 3 is a graph in which a weight reduction rate of a molten salt type heat medium according to an embodiment of the present invention is plotted with respect to a heating temperature, and illustrates a definition of a heat resistant temperature Th of the molten salt type heat medium.
　図１から図２を参照して、本発明の実施形態に係る溶融塩型熱媒体１０、溶融塩型熱媒体１０の使用方法、および、溶融塩型熱媒体１０を使用した太陽熱利用システム１を説明する。図１は、溶融塩型熱媒体１０を使用した太陽熱利用システム１の全体概略図であり、図２は、図１の太陽熱利用システム１の集光要素１１０を拡大した部分拡大図である。なお、本明細書において、溶融塩型熱媒体１０の成分の各成分比率は、モル百分率によって示される。すなわち、溶融塩型熱媒体１０の各成分比率は、溶融塩型熱媒体１０の全成分の合計モル数に対する各成分のモル数を百分率で表したものであり、（溶融塩型熱媒体１０の各成分のモル数）×１００／（溶融塩型熱媒体１０の全成分の合計モル数）［モルパーセント］で算出されるものである。また、本明細書において、流体連通するとは、同じ流体が流通できるように接続されていることをいい、直接的に接続されている場合、および、間接的に接続されている場合の両方を含む。また、本明細書は、太陽熱利用システム１を用いて説明するが、溶融塩型熱媒体１０は、それに限らず、熱源から熱を取り出す必要がある様々な用途に利用可能であり、例えば、火力発電システムなどにも利用可能である。 With reference to FIGS. 1 to 2, a molten salt heat medium 10, a method of using the molten salt heat medium 10, and a solar heat utilization system 1 using the molten salt heat medium 10 according to the embodiment of the present invention are described. explain. FIG. 1 is an overall schematic diagram of a solar heat utilization system 1 using a molten salt type heat medium 10, and FIG. 2 is a partially enlarged view in which the condensing element 110 of the solar heat utilization system 1 in FIG. 1 is enlarged. In addition, in this specification, each component ratio of the component of the molten salt type heat medium 10 is shown by mole percentage. That is, each component ratio of the molten salt type heat medium 10 represents the number of moles of each component with respect to the total number of moles of all the components of the molten salt type heat medium 10 as a percentage. The number of moles of each component) × 100 / (total number of moles of all components of the molten salt type heat medium 10) [mole percent]. Also, in this specification, fluid communication means that the same fluid is connected so that it can flow, and includes both cases of direct connection and indirect connection. . Moreover, although this specification demonstrates using the solar-heat utilization system 1, the molten salt type heat medium 10 can be utilized for various uses which need to take out heat from a heat source not only in it, for example, thermal power It can also be used for power generation systems.
［溶融塩型熱媒体］
　図１および図２を参照して、本発明の実施形態に係る溶融塩型熱媒体１０を説明する。本発明の実施形態に係る溶融塩型熱媒体１０は、火力発電や太陽熱発電など発電装置や水熱分解反応によって水素を製造する反応装置などを含む熱使用部３００において、対象物を加熱あるいは冷却して目的の温度にするために、溶融塩型熱媒体１０の加熱部１００と熱使用部３００との間での熱を移動させるのに使用される。例えば、発電装置においては、蒸気や燃焼ガスなどガスタービンを回転させるためのガス発生物が対象物であり、水素を製造する反応装置においては、水蒸気や金属酸化物のような反応対象物が対象物となる。 [Molten salt type heat medium]
With reference to FIG. 1 and FIG. 2, the molten salt type heat medium 10 which concerns on embodiment of this invention is demonstrated. The molten salt type heat medium 10 according to the embodiment of the present invention heats or cools an object in a heat use unit 300 including a power generation device such as thermal power generation and solar thermal power generation, a reaction device that produces hydrogen by hydrothermal decomposition reaction, and the like. In order to achieve the target temperature, it is used to transfer heat between the heating unit 100 and the heat using unit 300 of the molten salt heat medium 10. For example, in a power generation device, a gas generation product for rotating a gas turbine such as steam or combustion gas is an object, and in a reaction device for producing hydrogen, a reaction object such as water vapor or a metal oxide is an object. It becomes a thing.
　溶融塩型熱媒体１０は、少なくとも、１０モルパーセント以上３０モルパーセント以下の炭酸カリウム（Ｋ２ＣＯ３）と、１３モルパーセント以上３５モルパーセント以下の炭酸ナトリウム（Ｎａ２ＣＯ３）と、２０モルパーセント以上４０モルパーセント以下の炭酸リチウム（Ｌｉ２ＣＯ３）と、１．５モルパーセント以上１５モルパーセント以下の炭酸カルシウム（ＣａＣＯ３）と、５モルパーセント以上２０モルパーセント以下の炭酸バリウム（ＢａＣＯ３）と、合計で０．２モルパーセント以上３５モルパーセント以下の炭酸マグネシウム（ＭｇＣＯ３）及び／又は炭酸セシウム（Ｃｓ２ＣＯ３）と、を含有する炭酸塩混合物を含む。すなわち、溶融塩型熱媒体１０は、上述の前５成分に加えて、炭酸マグネシウム及び／又は炭酸セシウムを含有してなる、少なくとも６成分又は７成分系の熱媒体である。これによれば、溶融塩型熱媒体１０を低融点とし、かつ比較的高い耐熱性を有するものとすることができるため、溶融塩型熱媒体１０のための大掛かりな予熱要素を必要とせず、かつ溶融塩型熱媒体１０の加熱部１００と熱使用部３００との間の熱交換効率を高めることができる。また、溶融塩型熱媒体１０は、従来は熱媒体を使用できなかった高温プロセスでの熱媒体の使用を可能とし、熱使用部３００における高温プロセスの温度制御を容易にし、かつ安定化させることができる。なお、溶融塩型熱媒体１０は、物性を良好に制御する観点から、炭酸塩混合物のみから構成されてもよい。 The molten salt type heat medium 10 includes at least 10 mole percent to 30 mole percent potassium carbonate (K 2 CO 3 ), 13 mole percent to 35 mole percent sodium carbonate (Na 2 CO 3 ), and 20 moles. Lithium carbonate (Li 2 CO 3 ) of not less than 40 percent and not more than 15 mol, calcium carbonate (CaCO 3 ) of not less than 1.5 and not more than 15 mol percent, and barium carbonate (BaCO 3 ) of not less than 5 and not more than 20 mol percent. ) And a total of 0.2 mole percent to 35 mole percent magnesium carbonate (MgCO 3 ) and / or cesium carbonate (Cs 2 CO 3 ). That is, the molten salt type heat medium 10 is a heat medium of at least 6 or 7 component system containing magnesium carbonate and / or cesium carbonate in addition to the above 5 components. According to this, since the molten salt type heat medium 10 can have a low melting point and a relatively high heat resistance, a large preheating element for the molten salt type heat medium 10 is not required, And the heat exchange efficiency between the heating part 100 of the molten salt type heat medium 10 and the heat | fever use part 300 can be improved. Further, the molten salt type heat medium 10 enables the use of a heat medium in a high temperature process that could not be conventionally used, facilitates and stabilizes the temperature control of the high temperature process in the heat using part 300. Can do. In addition, the molten salt type heat medium 10 may be comprised only from the carbonate mixture from a viewpoint of controlling a physical property favorably.
　上述したように、溶融塩型熱媒体１０は融点Ｔｍが低く、耐熱温度Ｔｈが高いため、通常使用可能な温度範囲が広い。従って、溶融塩型熱媒体１０によれば、熱媒体の大掛かりな予熱要素を必要とせず、設備の小型化、ならびに熱媒体の使用量の削減を図ることができる。この他、溶融塩型熱媒体１０は、粘度が比較的低いため、管路４１０内を円滑に流れることができる。また、金属塩化物などの金属ハロゲン化物系の溶融塩を含有しないか、または、含有量が少ないから、設備の腐食を抑制できる点において熱媒体として優れた物性を有していると言える。 As described above, the molten salt type heat medium 10 has a low melting point Tm and a high heat resistant temperature Th, and therefore has a wide temperature range that can be normally used. Therefore, the molten salt type heat medium 10 does not require a large preheating element of the heat medium, and can reduce the size of the facility and reduce the amount of the heat medium used. In addition, since the molten salt heat medium 10 has a relatively low viscosity, it can smoothly flow through the pipe 410. Moreover, it can be said that it has excellent physical properties as a heat medium in that it does not contain a metal halide-based molten salt such as a metal chloride or has a small content, so that corrosion of equipment can be suppressed.
　なお、詳しくは後述するが、本発明における「耐熱温度」とは、溶融塩型熱媒体を加熱、溶融した後の５５０℃における試料重量から１重量％の重量減少が認められた温度を指すものとする。 In addition, although mentioned later in detail, the "heat-resistant temperature" in the present invention refers to a temperature at which a weight reduction of 1% by weight is recognized from the sample weight at 550 ° C. after the molten salt type heat medium is heated and melted. And
　また、詳しくは後述するが、本発明における「融点」とは、溶融塩型熱媒体を完全に加熱溶融し、一旦降温して固化させた後、再び一定速度で昇温させた際の、吸熱ピーク時における温度を指すものとする。 In addition, as will be described in detail later, the “melting point” in the present invention means an endotherm when a molten salt type heat medium is completely heated and melted, once cooled and solidified, and then heated again at a constant rate. It shall refer to the temperature at the peak.
　また、溶融塩型熱媒体１０は、上述の前５成分に加えて、炭酸マグネシウムと、炭酸セシウムとの両方を必須の成分として含有する炭酸塩混合物を含んでもよい。すなわち、溶融塩型熱媒体１０が炭酸マグネシウム及び炭酸セシウムを必須の成分とする、少なくとも７成分系の溶融塩型熱媒体であることで、溶融塩型熱媒体１０の融点Ｔｍを大きく低下させることができ、通常使用可能な温度範囲を広げることができる。 Further, the molten salt heat medium 10 may include a carbonate mixture containing both magnesium carbonate and cesium carbonate as essential components in addition to the above-mentioned five previous components. That is, the molten salt heat medium 10 is at least a seven-component molten salt heat medium containing magnesium carbonate and cesium carbonate as essential components, thereby greatly reducing the melting point Tm of the molten salt heat medium 10. The temperature range that can be normally used can be expanded.
　特に、溶融塩型熱媒体１０が上述の前５成分に加えて、炭酸マグネシウム及び炭酸セシウムの両方を必須の成分として含有する炭酸塩混合物を含む場合は、炭酸セシウムと炭酸マグネシウムのモル比（Ｃｓ：Ｍｇと記す）がＣｓ：Ｍｇ＝１：０．５～６であることが好ましい。 In particular, when the molten salt type heat medium 10 includes a carbonate mixture containing both magnesium carbonate and cesium carbonate as essential components in addition to the previous five components, the molar ratio of cesium carbonate to magnesium carbonate (Cs : Written as Mg) is preferably Cs: Mg = 1: 0.5-6.
　また、溶融塩型熱媒体１０が上述の前５成分に加えて、炭酸マグネシウム及び炭酸セシウムを必須の成分として含有する炭酸塩混合物を含む場合は、炭酸マグネシウムを１．０モルパーセント以上２５モルパーセント以下、炭酸セシウムを０．５モルパーセント以上２０モルパーセント以下含むことが好ましい。 Further, when the molten salt type heat medium 10 includes a carbonate mixture containing magnesium carbonate and cesium carbonate as essential components in addition to the foregoing five components, the magnesium carbonate is contained in an amount of 1.0 to 25 mole percent. Hereinafter, it is preferable that cesium carbonate is contained in an amount of 0.5 mole percent to 20 mole percent.
　上述の前５成分に加えて、炭酸マグネシウム及び炭酸セシウムを上記の範囲で含むことで、溶融塩型熱媒体１０は、炭酸マグネシウム又は炭酸セシウムのいずれか一方しか含まない系と比べて、融点Ｔｍと耐熱温度Ｔｈの両方を好適なものとすることができる。 By containing magnesium carbonate and cesium carbonate in the above range in addition to the above five components, the molten salt type heat medium 10 has a melting point Tm as compared with a system containing only either magnesium carbonate or cesium carbonate. And the heat resistant temperature Th can be made suitable.
　そして、溶融塩型熱媒体１０は、炭酸カリウム、炭酸ナトリウム、炭酸リチウム、炭酸バリウム、炭酸カルシウム、炭酸マグネシウム及び／又は炭酸セシウム以外のその他の成分を含んでもよいことは言うまでもない。溶融塩型熱媒体１０のその他の成分としては、炭酸ストロンチウム（ＳｒＣＯ３）などの上記以外のアルカリ金属またはアルカリ土類金属の炭酸塩、アルカリ金属またはアルカリ土類金属の硝酸塩、硫酸塩、酢酸塩およびリン酸塩、アルカリ金属またはアルカリ土類金属のハロゲン化物、その他溶融塩が例示される。 And it cannot be overemphasized that the molten salt type heat medium 10 may contain other components other than potassium carbonate, sodium carbonate, lithium carbonate, barium carbonate, calcium carbonate, magnesium carbonate, and / or cesium carbonate. Other components of the molten salt heat medium 10 include alkali metal or alkaline earth metal carbonates other than the above, such as strontium carbonate (SrCO 3 ), nitrates, sulfates, acetates of alkali metals or alkaline earth metals And phosphates, alkali metal or alkaline earth metal halides, and other molten salts.
　このように溶融塩型熱媒体１０にその他の成分を含有する場合には、溶融塩型熱媒体１０の融点や粘度を低くするなどの観点から、その他の成分が選定されることが望ましい。この場合、溶融塩型熱媒体１０に含有されるその他の成分の含有量は、０モルパーセントより大きく２０モルパーセント以下、好ましくは、０モルパーセントより大きく１０モルパーセント以下、より好ましくは、０モルパーセントより大きく５モルパーセント以下である。 Thus, when the molten salt type heat medium 10 contains other components, it is desirable to select other components from the viewpoint of reducing the melting point and viscosity of the molten salt type heat medium 10. In this case, the content of the other components contained in the molten salt heat medium 10 is greater than 0 mole percent and not greater than 20 mole percent, preferably greater than 0 mole percent and not greater than 10 mole percent, more preferably 0 mole. Greater than percent and less than or equal to 5 mole percent.
　なお、その他の成分として金属ハロゲン化物を含有する場合は、設備の腐食を防止する必要性から、溶融塩型熱媒体１０に含有される金属ハロゲン化物の含有量を、溶融塩型熱媒体１０の全量１００モルパーセント中、０．１モルパーセント以下とすることが好ましく、０．０５モル％以下とすることがより好ましく、全く配合しないことがさらに好ましい。 When the metal halide is contained as the other component, the content of the metal halide contained in the molten salt type heat medium 10 is changed from that of the molten salt type heat medium 10 due to the necessity of preventing the corrosion of the equipment. Of the total amount of 100 mole percent, it is preferably 0.1 mole percent or less, more preferably 0.05 mole percent or less, and still more preferably not blended at all.
　なお、溶融塩型熱媒体１０中、溶融塩型熱媒体１０に含まれる各炭酸塩は、それぞれが分離して存在することもできるが、複数種の炭酸塩が結合して、例えば炭酸ナトリウムカリウム（ＮａＫＣＯ３）のようにナトリウムおよびカリウムなどの複数の金属イオンを含んだ炭酸塩として存在していてもよい。 In addition, although each carbonate contained in the molten salt type heat medium 10 may exist separately in the molten salt type heat medium 10, a plurality of types of carbonates are combined to form, for example, sodium potassium carbonate. It may exist as a carbonate containing a plurality of metal ions such as sodium and potassium such as (NaKCO 3 ).
　上述のとおりであるから、本発明の実施形態に係る溶融塩型熱媒体は、例えば太陽熱発電システムにおいて熱媒体のための大掛かりな予熱要素を必要とせず、設備の小型化、ならびに熱媒体の使用量の削減を図ることができる。また、太陽熱発電システムの発電効率を上げ、水素製造などの高温プロセスを要する反応装置の加熱用にも適用することができる。 Since it is as above-mentioned, the molten salt type heat medium which concerns on embodiment of this invention does not require the large-scale preheating element for a heat medium, for example in a solar thermal power generation system, size reduction of an installation, and use of a heat medium The amount can be reduced. Moreover, the power generation efficiency of the solar thermal power generation system can be increased, and it can also be applied to heating reactors that require high-temperature processes such as hydrogen production.
［太陽熱利用システム］
　次に、図１および図２を参照して、本発明の実施形態に係る太陽熱利用システム１を説明する。太陽熱利用システム１は、溶融塩型熱媒体１０を使用するものであり、溶融塩型熱媒体１０と、溶融塩型熱媒体１０を太陽光によって加熱する太陽光加熱部１００と、溶融塩型熱媒体１０により供される熱を使用する熱使用部３００と、加熱された溶融塩型熱媒体１０を熱使用部３００に供給するために、太陽光加熱部１００と熱使用部３００とに流体連通する管路４１０と、を備える。 [Solar heat utilization system]
Next, with reference to FIG. 1 and FIG. 2, the solar-heat utilization system 1 which concerns on embodiment of this invention is demonstrated. The solar heat utilization system 1 uses a molten salt type heat medium 10, and includes a molten salt type heat medium 10, a solar heating unit 100 that heats the molten salt type heat medium 10 with sunlight, and a molten salt type heat medium. In order to supply the heat using part 300 using the heat provided by the medium 10 and the heated molten salt type heat medium 10 to the heat using part 300, the solar heating part 100 and the heat using part 300 are in fluid communication. A pipe line 410 to be provided.
　太陽光加熱部１００は、集光要素１１０を含み、集光要素１１０は、溶融塩型熱媒体１０が通過する集光管１１２と集光鏡１１４を含んでもよい。図示するように、集光要素１１０は、複数並列された集光管１１２に沿って複数の曲面状の反射鏡が配置されたトラフ型集光装置であってもよいし、図示しないタワー型、フレネル型、ディッシュ型その他公知の集光装置であってもよい。また、集光要素１１０は、必要に応じて、ヘリオスタットなどの図示しない部品を含んでもよいことは言うまでもない。 The solar heating unit 100 may include a condensing element 110, and the condensing element 110 may include a condenser tube 112 and a condenser mirror 114 through which the molten salt heat medium 10 passes. As shown in the figure, the light collecting element 110 may be a trough-type light collecting device in which a plurality of curved reflecting mirrors are arranged along a plurality of light collecting tubes 112 arranged in parallel. It may be a Fresnel type, a dish type, or other known light collecting device. Needless to say, the condensing element 110 may include components (not shown) such as a heliostat as necessary.
　太陽熱利用システム１は、さらに、管路４１０に流体連通する熱媒容器２１０，２２０，２３０の少なくともいずれか１つを備えてもよい。すなわち、熱媒容器２１０，２２０，２３０は、一時的に溶融塩型熱媒体１０を直接貯蔵する容器である。例えば、熱媒容器２１０，２２０，２３０は、太陽光加熱部１００で加熱された高温の溶融塩型熱媒体１０を蓄積できる高温熱媒タンク２１０と、熱使用部３００で熱を供した後の低温の溶融塩型熱媒体１０を蓄積できる低温熱媒容器２２０と、溶融塩型熱媒体１０の膨張タンク２３０である。 The solar heat utilization system 1 may further include at least one of the heat medium containers 210, 220, and 230 that are in fluid communication with the pipe line 410. That is, the heat medium containers 210, 220, and 230 are containers that temporarily store the molten salt heat medium 10 temporarily. For example, the heat medium containers 210, 220, and 230 are provided with the high temperature heat medium tank 210 that can store the high temperature molten salt heat medium 10 heated by the solar heating unit 100 and the heat using unit 300 after supplying heat. They are a low-temperature heat medium container 220 that can store a low-temperature molten salt heat medium 10 and an expansion tank 230 for the molten salt heat medium 10.
　熱媒容器２１０，２２０，２３０は、溶融塩型熱媒体１０と二酸化炭素とが充填されていることで、溶融塩型熱媒体１０を二酸化炭素でシールするものであってもよい。これによれば、溶融塩型熱媒体１０の耐熱性をより向上することができ、実用上の耐熱温度を１０００℃程度まで高めることができる。なお、熱媒容器２１０，２２０，２３０には、溶融塩型熱媒体１０を含む液体を入れ、空き領域に二酸化炭素のみを充填することができる。 The heat medium containers 210, 220, and 230 may be configured to seal the molten salt type heat medium 10 with carbon dioxide by being filled with the molten salt type heat medium 10 and carbon dioxide. According to this, the heat resistance of the molten salt heat medium 10 can be further improved, and the practical heat resistant temperature can be increased to about 1000 ° C. In addition, the liquid containing the molten salt type heat medium 10 can be put in the heat medium containers 210, 220, and 230, and the empty area can be filled with only carbon dioxide.
　熱使用部３００は、太陽熱を利用するものであれば特に限定されず、例えば、ガスタービンを含む発電装置および水熱分解反応によって水素を製造する反応装置などの熱使用要素３１０を含んでもよい。ガスタービンとしては、蒸気タービンや燃焼ガスタービンが例示される。例えば、水熱分解反応としては、鉄酸化物、酸化セリウム等の金属酸化物を用いた二段階水熱分解反応が例示される。二段階水熱分解反応は、窒素等の低酸素分圧ガス雰囲気下で６５０℃以上の高温において金属酸化物から酸素を放出させる酸素発生反応と、酸素を放出した後の金属酸化物に６５０℃以下の低温で水蒸気（Ｈ２Ｏ）を接触させ水素を発生させる水素発生反応の２つの反応を交互に繰り返すことによって行われるものである。 The heat use unit 300 is not particularly limited as long as it uses solar heat, and may include a heat use element 310 such as a power generation device including a gas turbine and a reaction device that produces hydrogen by a hydrothermal decomposition reaction. Examples of the gas turbine include a steam turbine and a combustion gas turbine. For example, as the hydrothermal decomposition reaction, a two-stage hydrothermal decomposition reaction using a metal oxide such as iron oxide or cerium oxide is exemplified. The two-stage hydrothermal decomposition reaction includes an oxygen generation reaction in which oxygen is released from a metal oxide at a high temperature of 650 ° C. or higher in a low oxygen partial pressure gas atmosphere such as nitrogen, and a 650 ° C. is applied to the metal oxide after releasing oxygen. This is performed by alternately repeating two reactions of hydrogen generation reaction in which water vapor (H 2 O) is brought into contact with each other at a low temperature to generate hydrogen.
　熱使用部３００は、熱使用要素３１０よりも後段に、後述の、溶融塩型熱媒体１０とは異なる熱媒体を冷却する冷却要素３２０をさらに含んでもよい。なお、熱使用部３００内では、管路４１０から供給される溶融塩型熱媒体１０が直接循環してもよいし、熱使用部３００は更に熱交換器３３０を備え、熱使用部３００内では、溶融塩型熱媒体１０と熱交換を行った溶融塩型熱媒体１０とは異なる別の熱媒体が循環してもよい。 The heat using unit 300 may further include a cooling element 320 that cools a heat medium different from the molten salt type heat medium 10 described later, after the heat using element 310. In addition, in the heat use part 300, the molten salt type heat medium 10 supplied from the pipe line 410 may be directly circulated. The heat use part 300 further includes a heat exchanger 330, and in the heat use part 300, Further, another heat medium different from the molten salt type heat medium 10 that has exchanged heat with the molten salt type heat medium 10 may be circulated.
　管路４１０は、例えば集光管１１２などの太陽光加熱部１００の配管と熱使用部３００の配管とに流体連通して、溶融塩型熱媒体１０を太陽光加熱部１００と熱使用部３００との間に循環させる。このため、管路４１０には、１または複数のポンプ４２０、および、１または複数のバルブ４６１，４６２が設けられていてもよい。 The pipe line 410 is in fluid communication with the piping of the solar heating unit 100 such as the condenser tube 112 and the piping of the heat using unit 300, for example, and the molten salt type heat medium 10 is connected to the solar heating unit 100 and the heat using unit 300. Circulate between. For this reason, the pipe line 410 may be provided with one or more pumps 420 and one or more valves 461 and 462.
　また、日射量に応じて太陽熱利用効率は変動するので、太陽熱利用システム１の太陽熱利用効率を安定化させるために、太陽熱利用システム１は、図示しない蓄熱部を更に備えてもよい。すなわち、太陽熱利用システム１は、日中や天候が良い時などに太陽熱を蓄熱部に蓄熱し、夜間や天候が悪い時などに太陽熱を蓄熱部から取出して利用できるようにしてもよい。 Further, since the solar heat utilization efficiency varies depending on the amount of solar radiation, the solar heat utilization system 1 may further include a heat storage unit (not shown) in order to stabilize the solar heat utilization efficiency of the solar heat utilization system 1. That is, the solar heat utilization system 1 may store solar heat in the heat storage unit during daytime or when the weather is good, and take out solar heat from the heat storage unit and use it at night or when the weather is bad.
　上述のとおりであるから、本発明の実施形態に係る太陽光利用システムは、耐熱性が高い溶融塩型熱媒体１０を使用することで太陽光利用システムをより効率化できる。例えば、太陽光利用システムは、発電効率を上げることができ、かつ、水素製造などの高温を要するプロセスに熱媒体を使用することができることで効率化される。また、溶融塩型熱媒体１０の使用は、通常使用可能な温度範囲が広いから、設備の小型化、ならびに運用コストの削減を実現することができる。 Since it is as above-mentioned, the sunlight utilization system which concerns on embodiment of this invention can make a sunlight utilization system more efficient by using the molten salt type heat medium 10 with high heat resistance. For example, the solar power utilization system can be improved in efficiency because power generation efficiency can be increased and a heat medium can be used for a process requiring high temperature such as hydrogen production. Moreover, since the use of the molten salt heat medium 10 has a wide temperature range that can be normally used, it is possible to reduce the size of the equipment and reduce the operation cost.
［溶融塩型熱媒体の使用方法］
　次に、図１および図２を参照して、本発明の実施形態に係る溶融塩型熱媒体１０の使用方法を説明する。溶融塩型熱媒体１０の使用方法は、例えば、溶融塩型熱媒体１０を、太陽光加熱部１００において太陽光で加熱すること、太陽光加熱部１００に流体連通する管路４１０によって、溶融塩型熱媒体１０を熱使用部３００に供給すること、及び、熱使用部３００において、溶融塩型熱媒体１０により供される熱を使用すること、を備える。 [How to use molten salt type heat medium]
Next, with reference to FIG. 1 and FIG. 2, the usage method of the molten salt type heat medium 10 which concerns on embodiment of this invention is demonstrated. The molten salt heat medium 10 can be used by, for example, heating the molten salt heat medium 10 with sunlight in the solar heating unit 100 and using a pipe 410 in fluid communication with the solar heating unit 100. Supplying the mold heat medium 10 to the heat using unit 300, and using the heat provided by the molten salt type heat medium 10 in the heat using unit 300.
　溶融塩型熱媒体１０の加熱ステップは、具体的には、太陽光加熱部１００において、集光要素１１０によって集められた太陽光が熱に変換され、溶融塩型熱媒体１０が加熱される。例えば、太陽光利用システム１の集光管１１２を通過する際に、集光鏡１１４によって集光管１１２に集められた太陽光によって、加熱が行われる。そして、溶融塩型熱媒体１０は、太陽光加熱部１００から熱使用部３００に太陽熱を移送し、熱使用部３００において、太陽熱を使用して、発電や水熱分解反応による水素製造などを行う。 Specifically, in the heating step of the molten salt heat medium 10, the sunlight collected by the light collecting element 110 is converted into heat in the solar light heating unit 100, and the molten salt heat medium 10 is heated. For example, when passing through the condenser tube 112 of the solar light utilization system 1, heating is performed by sunlight collected on the condenser tube 112 by the condenser mirror 114. And the molten salt type heat medium 10 transfers solar heat from the solar heating part 100 to the heat using part 300, and uses the solar heat in the heat using part 300 to perform hydrogen generation by power generation or hydrothermal decomposition reaction. .
　溶融塩型熱媒体１０の使用方法は、さらに、溶融塩型熱媒体１０の貯蔵ステップを含んでもよい。溶融塩型熱媒体１０の貯蔵ステップは、溶融塩型熱媒体１０を熱媒容器２１０，２２０，２３０に供給して、溶融塩型熱媒体１０を熱媒容器２１０，２２０，２３０に貯蔵するものである。この場合、溶融塩型熱媒体１０の貯蔵ステップの前または後に、熱媒容器２１０，２２０，２３０に二酸化炭素を充填する二酸化炭素充填ステップを含んでもよい。これによれば、熱媒容器２１０，２２０，２３０内を二酸化炭素雰囲気とすることができるから、熱媒容器２１０，２２０，２３０内において、加熱された溶融塩型熱媒体１０の減少をおさえられる。このようにして、溶融塩型熱媒体１０の耐熱性をより向上させることができる。 The method of using the molten salt type heat medium 10 may further include a storage step of the molten salt type heat medium 10. In the storage step of the molten salt type heat medium 10, the molten salt type heat medium 10 is supplied to the heat medium containers 210, 220, 230, and the molten salt type heat medium 10 is stored in the heat medium containers 210, 220, 230. It is. In this case, a carbon dioxide filling step of filling the heat medium containers 210, 220, and 230 with carbon dioxide may be included before or after the storage step of the molten salt heat medium 10. According to this, since the inside of the heat medium container 210, 220, 230 can be a carbon dioxide atmosphere, the reduction of the heated molten salt type heat medium 10 can be suppressed in the heat medium container 210, 220, 230. . In this way, the heat resistance of the molten salt heat medium 10 can be further improved.
　溶融塩型熱媒体１０の使用方法は、さらに、溶融塩型熱媒体１０を太陽光加熱部１００に供給するステップを含み、溶融塩型熱媒体１０を太陽熱利用システム１内に循環させて使用するものであることが好ましい。この場合は、溶融塩型熱媒体１０の劣化に伴って、溶融塩型熱媒体１０を交換するなどのメンテナンスが必要となる。本発明の実施形態に係る溶融塩型熱媒体１０の使用方法は、太陽熱利用システム１を用いて説明を行ったが、これに限定されず、火力発電システムなどにおいて使用されてもよい。この場合には、太陽光加熱部１００は、図示しない熱媒ボイラなどの熱媒ヒータを含む加熱部１００ａに置換される。 The method for using the molten salt type heat medium 10 further includes a step of supplying the molten salt type heat medium 10 to the solar heating unit 100, and the molten salt type heat medium 10 is circulated in the solar heat utilization system 1 for use. It is preferable. In this case, maintenance such as replacement of the molten salt heat medium 10 is required as the molten salt heat medium 10 deteriorates. Although the usage method of the molten salt type heat medium 10 which concerns on embodiment of this invention demonstrated using the solar-heat utilization system 1, it is not limited to this, You may use in a thermal power generation system etc. In this case, the solar heating unit 100 is replaced with a heating unit 100a including a heating medium heater such as a heating medium boiler (not shown).
　次に、本実施形態に係る溶融塩型熱媒体１０を更に具現化した実施例１～１５に係る溶融塩型熱媒体を説明する。まず、実施例および比較例にかかる溶融塩型熱媒体の調製方法および物性の測定方法などを詳細に説明する。 Next, the molten salt type heat medium according to Examples 1 to 15 that further embodies the molten salt type heat medium 10 according to the present embodiment will be described. First, a method for preparing a molten salt heat medium and a method for measuring physical properties according to Examples and Comparative Examples will be described in detail.
＜溶融塩型熱媒体の調製方法＞
（実施例１，２，３）
　実施例１，２，３に係る溶融塩型熱媒体の調製方法について説明する。実施例１に係る溶融塩型熱媒体は、炭酸カリウムと炭酸リチウムと炭酸ナトリウムと炭酸カルシウムと炭酸バリウムと炭酸マグネシウムとを、表１の実施例１，２の成分欄に記載の比率で混合した炭酸塩混合物を自動乳鉢で１時間微粉化したのち乾燥機を用いて３００℃、２時間加熱し脱水を行った。表１の実施例１，２，３の成分欄に記載の比率でロッキングミルによって５分間均一に混合し実施例１，２，３に係る溶融塩型熱媒体として用いた。 <Method for preparing molten salt type heat medium>
(Examples 1, 2, and 3)
A method for preparing a molten salt heat medium according to Examples 1, 2, and 3 will be described. In the molten salt type heat medium according to Example 1, potassium carbonate, lithium carbonate, sodium carbonate, calcium carbonate, barium carbonate, and magnesium carbonate were mixed at a ratio described in the component column of Examples 1 and 2 in Table 1. The carbonate mixture was pulverized for 1 hour in an automatic mortar and then dehydrated by heating at 300 ° C. for 2 hours using a dryer. The mixture was uniformly mixed for 5 minutes by a rocking mill at the ratio described in the component column of Examples 1, 2, and 3 in Table 1, and used as the molten salt type heat medium according to Examples 1, 2, and 3.
（実施例４，５，６）
　実施例４，５，６に係る溶融塩型熱媒体は、炭酸カリウムと炭酸リチウムと炭酸ナトリウムと炭酸カルシウムと炭酸バリウムと炭酸セシウムを、表１の実施例４，５，６の成分欄に記載の比率で混合した炭酸塩混合物を用いた以外は、実施例１，２，３に係る溶融塩型熱媒体と同様に調製した試料を、実施例４，５，６に係る溶融塩型熱媒体として用いた。 (Examples 4, 5, and 6)
The molten salt type heat medium according to Examples 4, 5, and 6 includes potassium carbonate, lithium carbonate, sodium carbonate, calcium carbonate, barium carbonate, and cesium carbonate in the component columns of Examples 4, 5, and 6 in Table 1. A sample prepared in the same manner as the molten salt type heat medium according to Examples 1, 2, and 3 except that the carbonate mixture mixed at the ratio of Used as.
（実施例７－１５）
　実施例７－１５に係る溶融塩型熱媒体は、炭酸カリウムと炭酸リチウムと炭酸ナトリウムと炭酸カルシウムと炭酸バリウムと炭酸マグネシウムと炭酸セシウムとを、表１の実施例７－１５の成分欄に記載の比率で混合した炭酸塩混合物を用いた以外は、実施例１，２，３に係る溶融塩型熱媒体と同様に調製した試料を、実施例７－１５に係る溶融塩型熱媒体として用いた。 (Examples 7-15)
The molten salt type heat medium according to Example 7-15 includes potassium carbonate, lithium carbonate, sodium carbonate, calcium carbonate, barium carbonate, magnesium carbonate, and cesium carbonate in the column of Example 7-15 in Table 1. A sample prepared in the same manner as the molten salt type heat medium according to Examples 1, 2, and 3 except that the carbonate mixture mixed at a ratio of 1 to 5 was used as the molten salt type heat medium according to Examples 7-15. It was.
（比較例１）
　比較例１に係る溶融塩型熱媒体は、炭酸カリウムと炭酸リチウムと炭酸ナトリウムと炭酸カルシウムと炭酸バリウムとを、表１の比較例１の成分欄に記載の比率で混合した硝酸塩混合物を用いた以外は、実施例１，２，３に係る溶融塩型熱媒体と同様に調製した試料を、比較例１の溶融塩型熱媒体として用いた。 (Comparative Example 1)
The molten salt type heat medium according to Comparative Example 1 used a nitrate mixture in which potassium carbonate, lithium carbonate, sodium carbonate, calcium carbonate, and barium carbonate were mixed at a ratio described in the component column of Comparative Example 1 in Table 1. Except for the above, samples prepared in the same manner as the molten salt type heat medium according to Examples 1, 2, and 3 were used as the molten salt type heat medium of Comparative Example 1.
＜耐熱温度測定方法＞
　実施例１～１５および比較例１の溶融塩型熱媒体１０ｍｇを白金製試料皿に入れ、精秤した後、示差熱熱重量同時測定装置（ＴＧ／ＤＴＡ、日立ハイテクサイエンス社製）にセットした。そして、実施例１～１５および比較例１の溶融塩型熱媒体を２３℃から１２５０℃まで１０℃／分の速度で昇温し、試料が溶融した後、５５０℃における試料重量を測定した。その後、昇温を継続し、当該５５０℃における試料重量から１重量％の重量減少が認められた温度を耐熱温度Ｔｈとした。測定された実施例１～１５と比較例１の溶融塩型熱媒体の耐熱温度Ｔｈに基づく評価を表１に示す。なお、当該評価基準は下記のとおりである： <Method for measuring heat-resistant temperature>
10 mg of the molten salt type heat medium of Examples 1 to 15 and Comparative Example 1 was put in a platinum sample dish, precisely weighed, and then set in a differential thermothermal gravimetric simultaneous measurement apparatus (TG / DTA, manufactured by Hitachi High-Tech Science Co., Ltd.). . Then, the molten salt type heat media of Examples 1 to 15 and Comparative Example 1 were heated from 23 ° C. to 1250 ° C. at a rate of 10 ° C./min, and after the sample was melted, the sample weight at 550 ° C. was measured. Thereafter, the temperature increase was continued, and the temperature at which a weight reduction of 1% by weight was observed from the sample weight at 550 ° C. was defined as the heat resistant temperature Th. Table 1 shows the evaluation based on the measured heat resistance temperature Th of the molten salt type heat media of Examples 1 to 15 and Comparative Example 1. The evaluation criteria are as follows:
　　　Ｓ：概ね８００℃以上の耐熱性を呈する
　　　Ａ：６５０℃以上８００℃未満の耐熱性を呈し、高耐熱用途には問題ない水準 S: Heat resistance of approximately 800 ° C. or higher A: Heat resistance of 650 ° C. or higher and lower than 800 ° C.
＜融点測定方法＞
　実施例１～１５および比較例１の溶融塩型熱媒体１０ｍｇを白金製試料皿に入れ、精秤した後、示差熱熱重量同時測定装置（ＴＧ／ＤＴＡ、日立ハイテクサイエンス社製）にセットした。そして、実施例１～１５および比較例１の溶融塩型熱媒体を２３℃から５５０℃まで４０℃／分の速度で昇温し、５５０℃で１０分間保持し溶融塩型熱媒体を溶融した後、１５０℃まで４０℃／分で降温し固化させ、さらに５５０℃まで１０℃／分昇温中の各溶融塩型熱媒体の吸熱ピーク時における温度を溶融塩型熱媒体の融点Ｔｍとした。測定は二酸化炭素中で行った。測定した実施例１～１５および比較例１の溶融塩型熱媒体の融点を表１に示す。 <Measuring method of melting point>
10 mg of the molten salt type heat medium of Examples 1 to 15 and Comparative Example 1 was put in a platinum sample dish, precisely weighed, and then set in a differential thermothermal gravimetric simultaneous measurement apparatus (TG / DTA, manufactured by Hitachi High-Tech Science Co., Ltd.). . Then, the molten salt type heat mediums of Examples 1 to 15 and Comparative Example 1 were heated from 23 ° C. to 550 ° C. at a rate of 40 ° C./min and held at 550 ° C. for 10 minutes to melt the molten salt type heat medium. Thereafter, the temperature was lowered to 150 ° C. at 40 ° C./min to solidify, and the temperature at the endothermic peak of each molten salt heat medium during the temperature rise to 10 ° C./min to 550 ° C. was defined as the melting point Tm of the molten salt heat medium. . The measurement was performed in carbon dioxide. Table 1 shows the measured melting points of the molten salt heat media of Examples 1 to 15 and Comparative Example 1.
Figure JPOXMLDOC01-appb-T000001
Figure JPOXMLDOC01-appb-T000001
　表１に示すように、本発明の溶融塩型熱媒体は、比較例１の炭酸カリウムと炭酸ナトリウムと炭酸リチウムと炭酸カルシウムと炭酸バリウムからなる溶融塩型熱媒体と比較して、耐熱温度は同等であるが、融点が有意に低いものであった。 As shown in Table 1, the heat resistance temperature of the molten salt type heat medium of the present invention is higher than that of the molten salt type heat medium composed of potassium carbonate, sodium carbonate, lithium carbonate, calcium carbonate, and barium carbonate in Comparative Example 1. Although equivalent, the melting point was significantly lower.
　これに対して、表１及び図３に示すように、実施例１から実施例１５の溶融塩型熱媒体は、軒並み融点が３６０℃台以下であって、なおかつ６５０℃を超えても重量減少が進みにくいものであった。なお、表１及び図３に示す数値は、二酸化炭素雰囲気中での測定値である。 On the other hand, as shown in Table 1 and FIG. 3, the molten salt type heat mediums of Examples 1 to 15 had a melting point of 360 ° C. or less across the board and reduced in weight even when it exceeded 650 ° C. It was difficult to proceed. In addition, the numerical value shown in Table 1 and FIG. 3 is a measured value in a carbon dioxide atmosphere.
　また、本実施例の溶融塩型熱媒体は、管路４１０などを通過するのに十分低い粘度を有するものであった。 Further, the molten salt type heat medium of this example had a viscosity sufficiently low to pass through the pipe line 410 and the like.
　以上、本発明を実施形態および実施例を用いて説明したが、本発明の技術的範囲は上記実施形態および実施例に記載の範囲には限定されないことは言うまでもない。上記実施形態および実施例に、多様な変更または改良を加えることが可能であることは当業者に明らかである。また、その様な変更または改良を加えた形態も本発明の技術的範囲に含まれ得ることが、特許請求の範囲の記載から明らかである。 As mentioned above, although this invention was demonstrated using embodiment and an Example, it cannot be overemphasized that the technical scope of this invention is not limited to the range as described in the said embodiment and Example. It will be apparent to those skilled in the art that various modifications or improvements can be made to the embodiments and examples. Further, it is apparent from the description of the scope of claims that embodiments with such changes or improvements can also be included in the technical scope of the present invention.
１　　　　　　　太陽熱利用システム
１０　　　　　　溶融塩型熱媒体
１００　　　　　加熱部
１１２　　　　　集光管
１１４　　　　　集光鏡
２１０　　　　　高温熱媒タンク
２２０　　　　　低温熱媒タンク
２３０　　　　　膨張タンク
３００　　　　　熱使用部
３１０　　　　　熱使用要素
３２０　　　　　冷却要素
４１０　　　　　管路
４２０　　　　　ポンプ
４６１，４６２　バルブ
Ｔｍ　　　　　　融点
Ｔｈ　　　　　　耐熱温度 DESCRIPTION OF SYMBOLS 1 Solar heat utilization system 10 Molten salt type heat medium 100 Heating part 112 Condenser pipe 114 Condensing mirror 210 High temperature heat medium tank 220 Low temperature heat medium tank 230 Expansion tank 300 Heat use part 310 Heat use element 320 Cooling element 410 Pipe line 420 Pump 461,462 Valve Tm Melting point Th Heat resistance temperature

Claims (10)

  1. 　１０モルパーセント以上３０モルパーセント以下の炭酸カリウムと、１３モルパーセント以上３５モルパーセント以下の炭酸ナトリウムと、２０モルパーセント以上４０モルパーセント以下の炭酸リチウムと、１．５モルパーセント以上１５モルパーセント以下の炭酸カルシウムと、５モルパーセント以上２０モルパーセント以下の炭酸バリウムと、合計で０．２モルパーセント以上３５モルパーセント以下の炭酸マグネシウム及び／又は炭酸セシウムとを含有する炭酸塩混合物を含むことを特徴とする溶融塩型熱媒体。 10 to 30 mole percent potassium carbonate, 13 to 35 mole percent sodium carbonate, 20 to 40 mole percent lithium carbonate, 1.5 to 15 mole percent Characterized in that it comprises a carbonate mixture containing calcium carbonate, 5 mol percent or more and 20 mol percent or less barium carbonate, and a total of 0.2 mol percent or more and 35 mol percent or less magnesium carbonate and / or cesium carbonate. Molten salt type heat carrier.
  2. 　請求項１記載の溶融塩型熱媒体であって、
    　少なくとも炭酸マグネシウムを含有することを特徴とする溶融塩型熱媒体。     The molten salt type heat medium according to claim 1,
    A molten salt heat medium comprising at least magnesium carbonate.
  3. 　請求項１記載の溶融塩型熱媒体であって、
    　少なくとも炭酸セシウムを含有することを特徴とする溶融塩型熱媒体。     The molten salt type heat medium according to claim 1,
    A molten salt type heat medium comprising at least cesium carbonate.
  4. 　請求項１記載の溶融塩型熱媒体であって、
    　炭酸マグネシウム及び炭酸セシウムを含有することを特徴とする溶融塩型熱媒体。     The molten salt type heat medium according to claim 1,
    A molten salt-type heat medium comprising magnesium carbonate and cesium carbonate.
  5. 　１０モルパーセント以上３０モルパーセント以下の炭酸カリウムと、１３モルパーセント以上３５モルパーセント以下の炭酸ナトリウムと、２０モルパーセント以上４０モルパーセント以下の炭酸リチウムと、１．５モルパーセント以上１５モルパーセント以下の炭酸カルシウムと、５モルパーセント以上２０モルパーセント以下の炭酸バリウムと、合計で０．２モルパーセント以上３５モルパーセント以下の炭酸マグネシウム及び／又は炭酸セシウムとを含有する炭酸塩混合物を含む溶融塩型熱媒体を、加熱部において加熱すること、
    　前記加熱部に流体連通する管路によって、前記溶融塩型熱媒体を熱使用部に供給すること、及び、
    　前記熱使用部において、前記溶融塩型熱媒体により供される熱を使用すること、を備えることを特徴とする溶融塩型熱媒体の使用方法。     10 to 30 mole percent potassium carbonate, 13 to 35 mole percent sodium carbonate, 20 to 40 mole percent lithium carbonate, 1.5 to 15 mole percent Molten salt heat comprising a carbonate mixture containing calcium carbonate, 5 mole percent to 20 mole percent barium carbonate, and a total of 0.2 mole percent to 35 mole percent magnesium carbonate and / or cesium carbonate Heating the medium in the heating section;
    Supplying the molten salt type heat medium to the heat using part by a conduit in fluid communication with the heating part; and
    The method of using a molten salt type heat medium, comprising: using heat provided by the molten salt type heat medium in the heat using part.
  6. 　請求項５記載の溶融塩型熱媒体の使用方法であって、
    　前記管路に流体連通された熱媒容器に前記溶融塩型熱媒体を供給すること、及び、
    　前記溶融塩型熱媒体を供給するステップの前または後に、前記熱媒容器に二酸化炭素を充填すること、をさらに備えることを特徴とする溶融塩型熱媒体の使用方法。     A method for using the molten salt heat medium according to claim 5,
    Supplying the molten salt heat medium to a heat medium container in fluid communication with the conduit; and
    Before or after the step of supplying the molten salt heat medium, the method of using the molten salt heat medium further comprises filling the heat medium container with carbon dioxide.
  7. 　１０モルパーセント以上３０モルパーセント以下の炭酸カリウムと、１３モルパーセント以上３５モルパーセント以下の炭酸ナトリウムと、２０モルパーセント以上４０モルパーセント以下の炭酸リチウムと、１．５モルパーセント以上１５モルパーセント以下の炭酸カルシウムと、５モルパーセント以上２０モルパーセント以下の炭酸バリウムと、合計で０．２モルパーセント以上３５モルパーセント以下の炭酸マグネシウム及び／又は炭酸セシウムと、を含有する炭酸塩混合物を含む溶融塩型熱媒体と、
    　前記溶融塩型熱媒体を太陽光によって加熱する太陽光加熱部と、
    　前記溶融塩型熱媒体により供される熱を使用する熱使用部と、
    　加熱された前記溶融塩型熱媒体を前記熱使用部に供給するために、前記太陽光加熱部と前記熱使用部とに流体連通する管路と、
    を備えることを特徴とする太陽熱利用システム。     10 to 30 mole percent potassium carbonate, 13 to 35 mole percent sodium carbonate, 20 to 40 mole percent lithium carbonate, 1.5 to 15 mole percent A molten salt form comprising a carbonate mixture containing calcium carbonate, 5 mol percent or more and 20 mol percent or less of barium carbonate, and 0.2 mol percent or more and 35 mol percent or less of magnesium carbonate and / or cesium carbonate in total A heat medium;
    A solar heating section for heating the molten salt heat medium with sunlight,
    A heat using part using heat provided by the molten salt type heat medium;
    A conduit in fluid communication with the solar heating section and the heat use section for supplying the heated molten salt heat medium to the heat use section;
    A solar heat utilization system comprising:
  8. 　請求項７記載の太陽熱利用システムであって、
    　さらに、前記管路に流体連通する熱媒容器を備え、
    　前記熱媒容器には、前記溶融塩型熱媒体と二酸化炭素とが充填されていることを特徴とする太陽熱利用システム。     The solar heat utilization system according to claim 7,
    Furthermore, a heating medium container in fluid communication with the pipe line is provided,
    The solar heat utilization system, wherein the heat medium container is filled with the molten salt heat medium and carbon dioxide.
  9. 　請求項７記載の太陽熱利用システムであって、
    　前記熱使用部は、ガスタービンを含む発電装置を含むことを特徴とする太陽熱利用システム。     The solar heat utilization system according to claim 7,
    The said heat utilization part contains the electric power generating apparatus containing a gas turbine, The solar heat utilization system characterized by the above-mentioned.
  10. 　請求項７記載の太陽熱利用システムであって、
    　前記熱使用部は、水熱分解反応によって水素を製造する反応装置であることを特徴とする太陽熱利用システム。     The solar heat utilization system according to claim 7,
    The solar heat utilization system, wherein the heat use part is a reaction apparatus for producing hydrogen by a hydrothermal decomposition reaction.
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