JP5923619B2 - Thermal storage system, power generation system - Google Patents

Description

  The present invention relates to a heat storage system and a power generation system.

  A conventional typical heat storage technique is summarized as shown in FIG. In particular, industrially, heat storage technology using molten salt is often used. This is a technique for storing heat using the sensible heat or latent heat of the molten salt, and corresponds to the methods (a) and (b) of FIG.

There exists patent document 1 as a form using the latent heat of molten salt, for example. This stores heat by using the latent heat of fusion of nitrates and eutectic salts with melting points of 150-350 ° C. The amount of stored heat is 100 to 350 J / g as latent heat of fusion. As a technique using sensible heat, for example, NaNO ₃ + KNO ₃ is used as a heat storage medium, and heat is stored in a temperature range of about 290 to 600 ° C. where the molten salt is in a molten state. The amount of stored heat is the specific heat of the molten salt × temperature difference. Such molten salt heat storage technology is also applied to a solar thermal power generation system.

Further, Patent Document 2 proposes a method of using an enthalpy change of an electronic phase transition between solid phases for heat storage. For example, the transition enthalpy when V (1-x) W _x O ₂ undergoes a magnetic phase transition at about 40 ° C. is used as heat storage. The value of x in V (1-x) W _x O ₂ is adjusted, or the phase transition temperature and the transition enthalpy are adjusted by using another compound. NaNiO ₂ is known as a material having an excellent magnetocaloric effect, and a refrigeration method using a change in spin entropy combining isothermal magnetization and adiabatic demagnetization has been proposed. Such an electronic phase transition temperature is −120 ° C. to 213 ° C., and a transition enthalpy is 20 to 326 J / cc. Since the phase transition between the solid phases is used, the heat storage material is not melted, and there is an advantage that there is no leakage from the container. The amount of heat stored by this method is comparable to the latent heat of the molten salt.

JP 2011-58367 A JP 2010-163510 A

One way to increase the amount of heat storage is to increase the heat collection temperature. This is because the higher the temperature of the heat source for converting the heat energy to another energy form, the larger the heat storage amount. However, in Patent Document 1, for example, NaNO ₃ -KNO ₃ is thermally decomposed into NaNO ₂ , KNO ₂ , and O ₂ at about 600 ° C., so that there is a limit to increasing the temperature. Therefore, the use temperature range at the time of utilizing molten salt as a heat storage material becomes relatively narrow, and there is a problem in improving the heat storage amount.

  Moreover, in the thing of patent document 2, the use temperature as a thermal storage system is -120 degreeC-213 degreeC depending on the electronic phase transition temperature intrinsic | native to a substance, and is unsuitable for the thermal storage in higher temperature than a phase transition temperature. Therefore, similarly to the above, there is a problem in improving the heat storage amount.

  The object of the present invention is to improve the amount of heat storage.

In order to achieve the above object, the present invention provides a heat storage system including a heat storage unit that stores heat energy supplied from a heat source, wherein the heat storage material that stores or transports heat energy in the heat storage unit includes V ₂ O ₅ . It is characterized by being glass.

  According to the present invention, the amount of stored heat can be improved.

The schematic diagram at the time of heat storage utilization. The figure which shows the correlation of the molar entropy of V type | system | group glass, and temperature. The figure which shows the DTA curve of V type | system | group glass. The figure which shows the temperature change with respect to the heating time at the time of glass heating. The figure which shows the temperature change with respect to entropy at the time of glass heating. The figure which shows the thermal storage part of a thermal storage system. The figure which shows the thermal storage part of a thermal storage system. An example of a solar thermal power generation system. An example of a heat storage system. The figure which shows the Gibbs energy change of reaction with respect to the alloy of V type glass and molten salt.

The melting point of the glass containing V ₂ O ₅ as a component can be adjusted in the range of about 200 to 600 ° C. depending on the ratio of the components constituting the glass. In addition, the V-type glass in the molten state has a very low viscosity and does not decompose or evaporate up to around 900 ° C and is stable. In the present invention, a heat storage system using the latent heat of fusion utilizing such properties of the V glass and a heat storage system using sensible heat of the molten V glass are provided.

  The principle of heat storage technology using V glass is described below. First, the principle of the heat storage technology using the latent heat of fusion of V glass is described.

FIG. 2 is a graph showing the correlation between the molar entropy of V-based glass and temperature. The V-based glass is in a molten state at a temperature higher than the melting point Tm, and the molar entropy at the melting point Tm is defined as Sliq. When the molten V glass is cooled, solidification begins at Tm and latent heat is released. When rapidly cooled, the atoms lose their freedom of rearrangement due to Tg, that is, the glass state. The molar entropy at the time of Tg is Sglass, and the released latent heat ΔH is ΔH = ΔS1 × Tm = (Sliq-Sglass) × Tm
It is. When the molten V-based glass is removed, crystallization occurs, and the molar entropy is lower than that in the glass state. If the molar entropy when the glass is completely crystallized is Scrys, the latent heat ΔH released during crystallization is ΔH = ΔS2 × Tm = (Sliq-Scrys) × Tm
In principle, the value is larger than the latent heat in the glass state. That is, the amount of heat storage can be further increased by crystallization of most of the molten V-based glass. Depending on the crystallization rate of the crystallized glass, the molar entropy takes a value between Scrys and Sglass. In the present invention, these latent heats can also be used for heat storage.

In order to increase the crystallinity of the V-based glass, ceramic particles that can be crystal nuclei are preferably mixed in the V-based glass. The heat medium in this case is a mixture of glass and ceramic particles containing V ₂ O ₅ as a component, and at least a part of the glass is crystallized at room temperature.

The principle of the heat storage technology using the sensible heat of V glass is as follows. In this case, the product of the specific heat Cp of the molten V-based glass and the temperature difference ΔT is the amount of heat stored.
ΔH = Cp × ΔT
By adjusting the composition of V-based glass, the melting point can be lowered to 300 ° C or lower, and since it can exist stably in a liquid state up to a high temperature range of about 900 ° C, ΔT can be set to about 600 ° C or higher. Is possible. When using V-type glass as a heat storage material, the operating temperature range can be increased, so that the amount of heat storage can be increased.

  Mixing ceramic particles with V-based glass is also effective for increasing the sensible heat of molten V-based glass. The apparent specific heat can be increased and the sensible heat can be increased by mixing ceramic particles having a specific heat larger than that of the V-based glass to such an extent that the fluidity of the V-based glass is not impaired.

  The ceramic particles are preferably magnesium oxide, silica-based glass, mullite, porcelain, clay refractory, steatite, alumina, or spinel because they are difficult to dissolve in the molten V-based glass.

  In general, the maximum temperature of the heat source equipment that generates or collects heat is determined according to the system and scale, but the heat storage system of the present invention is based on the maximum temperature (maximum operating temperature) of the heat source equipment. Design the melting point optimally.

  When a molten salt is applied as in the prior art, the high corrosiveness at high temperatures becomes a problem, so a high-cost corrosion-resistant alloy material must be used, but the V-based glass that is the heat transfer medium of the present invention Since is an oxide, it is not as corrosive as molten salt.

  In this example, vanadium oxide glasses having various compositions were prepared, and the latent heat and sensible heat of the glasses were evaluated.

(Production of glass)
Glasses (Nos. 1 to 12) having the compositions shown in Table 1 were produced. The composition in the table is indicated by the mass ratio in terms of oxide of each component. As a starting material, oxide powder (purity 99.9%) manufactured by Kojundo Chemical Laboratory Co., Ltd. was used. In some samples, Ba (PO ₃ ) ₂ (barium phosphate, manufactured by Rasa Industry Co., Ltd.) was used as the Ba source and P source.

Each starting material powder was mixed at a mass ratio shown in Table 1, and a total of 200 g of the mixed powder was put in a crucible. Here, when the ratio of Ag ₂ O in the raw material was 40% by mass or less, a platinum crucible was used, and when it was 40% by mass or more, an alumina crucible was used. In mixing, in consideration of avoiding excessive moisture absorption to the raw material powder, mixing was performed in a crucible using a metal spoon.

  The crucible containing the raw material mixed powder was placed in a glass melting furnace and heated and melted. The temperature was raised at a rate of 10 ° C./min, and the molten glass was held for 1 hour at the set temperature (700 to 900 ° C.) while stirring. Thereafter, the crucible was taken out from the glass melting furnace, and the glass was cast into a graphite mold heated to 150 ° C. in advance. Next, the cast glass was moved to a strain relief furnace that had been heated to a strain relief temperature in advance, and strain was removed by holding for 1 hour, and then cooled to room temperature at a rate of 1 ° C./min. The glass cooled to room temperature was pulverized to produce glass powder having the composition shown in the table.

(Evaluation of glass characteristic temperature)
The characteristic temperature of each glass powder obtained above was measured by differential thermal analysis (DTA). The DTA measurement was performed at a heating rate of 5 ° C./min in the atmosphere with the reference sample (α-alumina) and the measurement sample each having a mass of 650 mg. In this example, the second endothermic peak temperature of the DTA curve of the glass was defined as the softening point Ts (see FIG. 3). Other glass characteristic temperatures are shown in FIG.

(Evaluation of specific heat and latent heat)
Specific heat and latent heat were measured by a differential scanning calorimeter (DSC). The peak area of the DSC curve is the product of power and time and gives the amount of heat directly. In addition, since the DSC baseline is related to the difference in specific heat between the reference material and the sample, the specific heat of the material can be measured using a material with a known specific heat. In this example, sapphire was used as a reference material.

  Table 1 shows the measurement results of glass transition point, softening point, specific heat and latent heat. Latent heat means melting latent heat and corresponds to the endothermic peak of the melting point portion in FIG. As shown in Table 1, by adjusting the glass composition, it can be adjusted to an appropriate melting point according to the heat collection temperature of the heat storage system.

  When using the latent heat of glass, the temperature should rise at least to the extent that the glass melts, so if the melting point of the glass is close to the maximum operating temperature of the heat storage system, the amount of heat stored will be increased and collected. Heat can be used without waste.

  When the sensible heat of glass is used, the operating temperature range is not less than the melting point of the glass and not more than the heat resistance temperature of the heat resistant alloy used for the glass container or piping, so the vicinity of the heat resistance temperature is the maximum use temperature. The heat-resistant temperature of heat-resistant alloys that are generally used is about 900 ° C., and the lower the melting point of glass, the wider the operating temperature range and the greater the amount of heat stored.

V-type glass used in heat storage systems is used for heat input and output in a closed system, so that it does not require particularly excellent water resistance, mechanical characteristics, and electrical characteristics, and may be crystallized. Thus, a glass having a relatively wide composition range can be applied, and in terms of oxide, V ₂ O ₅ : _{5 to} 65 wt%, Ag ₂ O: 0 to 60 wt%, WO ₃ : 0 to 45 wt%, TeO ₂ : 0 to 50 wt% %, P ₂ O ₅ : 0 to 45 wt% can be used. Thereafter, the melting point of the glass is appropriately adjusted according to the heat collection temperature of the heat storage system. For example, the description of 5 to 65 wt% means 5 wt% or more and 65 wt% or less, and the same shall apply hereinafter.

The melting point of the glass containing V ₂ O ₅ : 10 to 25 wt%, WO ₃ : 20 to 45 wt%, P ₂ O ₅ : 25 to 40 wt% in terms of oxide is in the range of 650 to 800 ° C. Glass with a suitable composition range is suitable for heat storage systems where the heat collection temperature is 700 ° C or higher.

Glass containing V ₂ O ₅ : 35 to 65 wt%, TeO ₂ : 0 to 40 wt%, P ₂ O ₅ : 0 to 45 wt% in terms of oxide is the most common V glass composition, and its melting point Is generally in the range of 400-650 ° C. That is, glass having such a composition range is suitable for a heat storage system having a heat collection temperature of 500 to 700 ° C.

A glass containing at least Ag ₂ O, V ₂ O ₅ and TeO _{2 in} terms of oxide and having a total content of Ag ₂ O, V ₂ O ₅ and TeO ₂ of 75 wt% or more is used. Or V ₂ O ₅ in terms of _{oxide: 5~65wt%, Ag 2 O:} 10~60wt%, TeO 2: 15~50wt%, the glass containing. Since these glasses have a melting point of 300 ° C. or lower, if the maximum operating temperature of the heat storage system is 900 ° C., they can be used as a heat storage material in a wide temperature range of 600 ° C. or higher. Also, when the heat collection temperature is 500 ° C. or lower, or when the molten V-based glass is used as a heat transfer fluid by circulating in the pipe, the lower melting point is better, so these composition ranges are preferable.

  As a comparative example, the characteristics of soda lime glass are also described. Since the melting point of soda-lime glass was high and the latent heat could not be measured, the estimated value is shown. The temperature at which the soda-lime glass flows must be at least 1200 ° C., which exceeds the heat-resistant temperature of the heat-resistant alloy. Accordingly, the glass of the comparative example cannot be used as a heat storage material and is not suitable as a heat storage material.

(Evaluation of crystallinity)
In the above examples, Nos. 1, 6, and 11 are glasses that are difficult to crystallize, and Nos. 2 and 10 are glasses that are easily crystallized. In Table 2, a small amount of Al ₂ O ₃ powder for promoting crystallization was mixed in each glass (0, 1, 5, 10 vol%), and the calorific value at the time of crystallization was determined from each DSC curve. In addition, X-ray analysis of the sample after the DSC test was performed to estimate the crystallinity. Although it is difficult to crystallize with a single glass, a part of the glass mixed with Al ₂ O ₃ powder that becomes the nucleus of crystallization crystallized and an exothermic peak appeared. In any glass, the degree of crystallization and the amount of heat generated during crystallization increased as the amount of Al ₂ O ₃ powder mixed increased.

About 11% of the glass in which 1 vol% Al ₂ O ₃ was added to No. 1 crystallized during cooling, and the calorific value at that time was 8.5 J / g. This is a smaller value than the latent heat of fusion of 52 J / g. When the amount of Al ₂ O _{3 to be} added is increased from 5 vol% to 10 vol%, the crystallinity becomes 28% and 35%, respectively, and the calorific value becomes 48 J / g and 55 J / g. As shown in FIG. 2, the glass crystallizes into a lower molar entropy state. By setting the crystallinity to about 30% or more, the amount of heat generated during crystallization is melted. It was shown to be equal to or greater than the latent heat. By using the amount of heat that enters and exits during crystallization for heat storage, a heat storage system with a larger amount of heat storage can be configured.

(Heat storage amount of glass)
When the glass for heat storage at room temperature is heated at a constant output, the temperature of the glass rises and accumulates heat corresponding to specific heat × temperature. When the glass reaches the melting point, the melting starts, and the temperature is constant until the melting is completed, and latent heat is accumulated. If the completely melted glass is further heated, the temperature of the glass rises again, and an amount of heat corresponding to specific heat × temperature is accumulated.

For example, FIG. 4 shows the temperature change of glass when 1 m ³ glass is heated at 0.01 GJ / min. Each marker indicates a molten salt having a melting point of 200 ° C. (comparative example), glass having a melting point of 250 ° C., and glass having a melting point of 500 ° C. (with crystallization and without crystallization). Each temperature curve has a plateau region at the melting point. The symbol “Δ” shows a temperature curve for a glass that does not crystallize at a melting point of 500 ° C., but the plateau region is narrow because of the low latent heat during crystallization. Thus, when the heat storage glass is heated at a constant speed, the temperature rises accordingly.

  In order to compare the heat storage amounts of glass, FIG. 5 is a diagram in which the horizontal axis represents the entropy (S) obtained by the glass heat storage material during heating and the vertical axis represents temperature (T). Each marker indicates a molten salt (comparative example) having a melting point of 200 ° C., glass having a melting point of 250 ° C., and glass having a melting point of 500 ° C. This figure is a TS diagram and represents the state of the heat storage material. When the molten salt is heated from the room temperature state (state 1), the state changes along the curve 1-2 on the TS diagram to reach the maximum temperature state (state 2). At this time, the area under the curve 1-2 represents the heat storage amount.

  Similarly, the glass having a melting point of 250 ° C. in the room temperature state (state 1) is heated, and the path to the maximum temperature state (state 3) is 1 → B → C → D → 3. The area under this curve is the amount of heat stored in the glass with a melting point of 250 ° C. In the case of glass with a melting point of 500 ° C., the path from state 1 to 3 is 1 → B → A → D → 3, and the area under the curve is the heat storage amount of the glass with a melting point of 500 ° C. Since state 3 is hotter than state 2, the amount of heat stored in any glass is greater than that of the molten salt, and the amount of heat stored in a glass with a melting point of 500 ° C is the amount of heat given by the area of the polygon ABCD Greater than the amount of heat stored.

  Table 3 shows the result of estimating the amount of heat stored when the V-type glass produced as described above is used as a heat storage material, in comparison with the example of the molten salt. The table lists typical values. When using V-type glass as a heat storage material, the specific heat does not reach that of molten salt, but V-type glass is stable up to nearly 900 ° C, so the temperature range used as a heat storage material can be widened, and the melting point can be adjusted. From this, the latent heat of fusion can be adjusted to be high, and by using the latent heat at the time of crystallization, a larger heat storage amount than the molten salt can be realized.

In this embodiment, a mode using latent heat will be described. Glass, which is a heat storage material, is used in a state where a solid and a liquid coexist. As an example of glass containing V ₂ O ₅ , several ten J / g of latent heat of fusion enters and exits as the phase changes from the solid state. Such latent heat of fusion varies depending on the glass component, melting point, and crystallinity. Using such latent heat of fusion of glass has the advantage that the amount of heat energy that can be stored in the same volume is greatly improved and that a constant temperature level of the melting point is automatically protected. That is, for example, it is possible to prevent thermal damage to peripheral equipment due to a sudden rise in the heat collection temperature of the heat collection system.

As one form of the heat storage system using the melting latent heat of V-type glass, V-type glass enclosed in a capsule is used as a heat storage medium. Since the thermal conductivity of V glass is low, encapsulating it in multiple capsules increases the heat transfer area. Since the corrosiveness of V-based glass is low, stainless steel or aluminum can be used for the capsule material.
The amount of energy that can be stored in a unit volume by using the latent heat of melting of glass is Q = ΔH × ρ at the melting point Tm.
Here, ΔH is the latent heat of fusion (J / g), and ρ is the density (g / cm ³ ). The latent heat of fusion can be expressed by the product of the entropy difference between the glass before and after melting and the melting point, and therefore ΔH generally increases in proportion to Tm. As a matter of course, the melting point of the glass used for the heat storage material is lower than the heat collection temperature. EXAMPLE melting point of the glass containing V ₂ O ₅ as shown in 1 and can be adjusted by the ratio of V ₂ O ₅ content and other components, collecting the heat collecting system a melting point glass in this embodiment Design according to the heat temperature. That is, by designing a glass having a melting point close to the heat collection temperature, the latent heat of fusion can be designed to the maximum according to the heat collection temperature. According to thermodynamics, it is preferable that the temperature of the heat source for converting to another energy form is high, so that it is an important advantage to be able to control the melting point of the heat storage material.

  Since the utilization of latent heat of fusion is performed by a heat storage material coexisting with solid and liquid, it is not suitable for transport by a pump. For example, FIG. 6A illustrates a latent heat type heat storage material. The heat storage material is filled in a certain container, and heat energy is transferred from the heat storage material to another heat medium through the wall of the container. A plurality of capsules 3 in which the heat storage glass 2 is enclosed in the heat-resistant container 1 are installed, a heat medium such as water vapor flows from the steam inlet 4, exchanges heat with the heat storage glass, reaches a high temperature and flows out from the outlet 5. FIG. 6B also heats the heat medium according to the same principle, but in the case of FIG. 6B, it is not enclosed in a capsule. A heat transfer tube 6 is installed in the heat-resistant container 1, and the heat storage glass 2 is filled around the heat transfer tube 6. The heat medium that has entered from the steam inlet 4 passes through the heat transfer tube 6 and exchanges heat with the heat storage glass 2, reaches a high temperature, and is discharged from the outlet 5.

  FIG. 7 is an example of a solar thermal power generation system to which a heat storage system is applied. The solar thermal power generation system having such a configuration is a conventional one, but the heat storage system is the one of this embodiment. Since the vapor temperature obtained from the solar concentrator 7 cannot be determined in advance due to the weather or the like, the vapor accumulator 8 is also used. The V-type glass that is a heated heat storage material is stored in the V-type glass regenerator 9. Heated heat medium such as water vapor is blown to the turbine 11 through the temperature reducer 10 to operate the generator 12. Thereafter, the heat medium is condensed in the condenser 13 and circulated through the ground condenser 14. 15 is a deaerator.

  For example, the heat storage capacity of a heat storage system configured by filling a No. 1 glass into a 50mm x 10m pipe and bundling it is 1.8Gcal (0.43GJ).

  In the case of a system in which there are a plurality of heat collecting portions 7 and the respective heat collecting temperatures are different, a plurality of types of V-based glasses having different melting points derived from the respective heat collecting temperatures may be used.

  In this embodiment, a mode using sensible heat will be described. One of the features of this example is that a V-type glass in a molten state with low viscosity is used as a heat transfer medium. For example, the glasses shown in Table 1 can be applied.

The characteristics of the glass containing at least V ₂ O ₅ as a component are that it has a low melting point and that the viscosity of the molten glass is extremely low. Therefore, the molten V2O5 glass can be circulated through a pipe using a pump. The concept of the heat storage system using the sensible heat of glass is shown in FIG. A heat storage glass 17 is filled in the heat storage material tank 16. When taking heat energy into the heat accumulator, the molten glass is circulated by the pump 18, the heat of the heat source 19 is taken through the heat exchanger 20, and the heat accumulator tank 16 is returned.

  On the other hand, when extracting heat, the molten glass is pumped out by the pump 22 and sent to the heat exchanger, where it is dissipated to operate the load 21 and return the cooled molten glass to the tank again. In the case of utilizing sensible heat, the temperature of the heat storage glass rises by taking in heat energy, and the temperature drops by taking it out. For this reason, although a constant temperature level is not maintained, since the heat storage glass is liquid, it can be transported by a pump to a required place.

The amount of thermal energy Q that can be stored in a certain volume of molten glass by sensible heat is approximately
Q = Cp × ρ × ΔT
It can be expressed as Here, Cp is the specific heat, ρ is the density, and ΔT is the temperature change width of the heat storage glass. The merit of utilizing the sensible heat of molten glass is that ΔT can be increased in a stable molten state, and that the absolute value of the temperature range can be adjusted by the melting point of the glass.

  When one tank is used as shown in FIG. 8, inevitably high-temperature molten glass is stored in the upper part of the tank and low-temperature molten glass is stored in the lower part, and a temperature gradient is generated inside the tank. In such a case, the molten glass in the tank can be agitated by a blade that agitates the inside. Alternatively, a two-tank type using separate tanks at high and low temperatures is also possible.

Compare the corrosivity of V glass and molten salt. Molten salts such as potassium nitrate and sodium nitrate decompose in the high temperature region as follows.
KNO ₃ → KNO ₂ + 0.5O ₂
NaNO ₃ → NaNO ₂ + 0.5O ₂
At this time, if an Fe-based alloy or Ni-based alloy is present in the vicinity, the metal is oxidized or corroded with alkali.
NaNO ₃ + Fe = 0.5O ₂ + 0.5N ₂ + NaFeO ₂
KNO ₃ + Fe = 0.5O ₂ + 0.5N ₂ + KFeO ₂
NaNO ₃ + Ni = NiO + NaNO ₂
KNO ₃ + Ni = NiO + KNO ₂
On the other hand, when the V-based glass of the present invention is brought into contact with the Fe-based alloy or Ni-based alloy, the metal is oxidized. Although the details of the reaction mechanism have not been clarified yet, it is considered that the reaction involves the reduction of V ₂ O ₅ , which is a constituent component of V glass, as follows.
1.5V ₂ O ₅ + Fe = 0.5Fe ₂ O ₃ + 1.5V ₂ O ₄
V ₂ O ₅ + Ni = NiO + V ₂ O ₄
It has been confirmed that these reactions do not proceed greatly. FIG. 9 shows a graph obtained by calculating the Gibbs energy change of each reaction for the corrosion of the metal by the molten salt and the progress of the oxidation of the metal by the V-based glass. The vertical axis represents the Gibbs energy change of the reaction, the horizontal axis represents the temperature, and each reaction is shown by mark. The smaller the Gibbs energy change of the reaction, the more likely the reaction will proceed.

  As is apparent from FIG. 9, it is shown that the Fe-based alloy is more easily corroded and oxidized than the Ni-based alloy, and the Ni-based alloy is more suitable for the tank and piping materials used in the heat storage system. Also, the Gibbs energy change related to the reaction between V-based glass and Ni-based alloy and Fe-based alloy shows a larger value than that of molten salt, and V-based glass does not corrode heat resistant alloys as much as molten salt. Indicated.

1: Heat-resistant container 2: Thermal storage glass 3: Capsule 4: Steam inlet 5: Steam outlet 6: Heat transfer tube 7: Solar concentrator 8: Steam accumulator 9: V-type glass thermal storage 10: Temperature reducer 11: Turbine 12: Generator 13: Condenser 14: Ground condenser 15: Deaerator 16: Thermal storage material tank 17: Thermal storage glass 18: Pump 19: Heat source 20: Heat exchanger 21: Load 22: Pump

Claims (9)

A heat storage system comprising a heat storage unit for storing heat energy supplied from a heat source, wherein the heat storage material that stores or transports heat energy in the heat storage unit is glass containing V ₂ O _5. . 2. The glass according to claim 1, when the component is expressed by an oxide, V ₂ O ₅ : _{5 to} 65 wt%, Ag ₂ O: 0 to 60 wt%, WO ₃ : 0 to 45 wt%, TeO ₂ : 0 to 50 wt% %, P ₂ O _5: heat storage system comprising 0~45wt%, the. According to claim 1, wherein the glass is V ₂ O ₅ when representing the component _{oxides: 10~25wt%, WO 3: 20~45wt} %, P 2 O 5: characterized in that it comprises 25～40Wt%, the Heat storage system. According to claim 1, wherein the glass is V ₂ O ₅ when representing the component _{oxides: 35~65wt%, TeO 2: 0~40wt} %, P 2 O 5: characterized in that it comprises 0～45Wt%, the Heat storage system. _{2. The} heat storage system according to claim 1, wherein the glass contains V ₂ O ₅ , Ag ₂ O, and TeO ₂ when the components are represented by oxides, and the total content is 75% by mass or more. 2. The glass according to claim 1, wherein the glass contains V ₂ O ₅ : _{5 to} 65 wt%, Ag ₂ O: 10 to 60 wt%, and TeO ₂ : 15 to 50 wt% when the components are represented by oxides. Heat storage system.   The heat storage system according to claim 1, wherein the heat storage material includes ceramic particles having a specific heat larger than that of the glass.   The heat storage system according to claim 1, wherein the thermal energy is supplied from solar heat.   A power generation comprising: the heat storage system according to any one of claims 1 to 8, a turbine driven by a heat medium that exchanges heat with the heat storage material in the heat storage system, and a generator driven by the turbine. system.

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