JP2009019866A - Chemical heat accumulating device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve a heat radiating quantity, in a chemical heat accumulating device for supplying water of liquid to a heat accumulating material of liquid. <P>SOLUTION: This chemical heat accumulating device 50 has a heat accumulator 9, a condenser 10 condensing steam and storing condensed water, a recirculating passage 22 returning the steam generated by heating the heat accumulating material 8 in the heat accumulator 9 to the condenser 10 in a heat accumulating process, and a supply passage 23 supplying the water in the condenser 10 to the heat accumulator 9 in a heat radiating process. The heat accumulating material 8 using calcium chloride is stored in a heat accumulating tank 21 of the heat accumulator 9, as the heat accumulating material 8 having a specific gravity larger than the water in a liquid phase state and capable of accumulating or radiating heat by performing reversible reaction causing desorption of the water. The supply passage 23 is constituted so as to supply the water from a lower side part of the heat accumulating tank 21 in the heat accumulating tank 21. In the heat radiating process, supply of the water is finished before the supplied water reaches an interface 8a of the heat accumulating material 8. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a chemical heat storage device using a chemical reaction.

Conventionally, a heat storage technique for storing thermal energy has been effective as an energy saving technique. In recent years, hot water supply equipment using a CO ₂ heat pump or a fuel cell cogeneration system has attracted attention, but the development of high-density heat storage technology has been awaited in order to downsize these equipment and improve installation. ing.

  Heat storage technology is roughly classified into sensible heat storage technology, latent heat storage technology, and chemical heat storage technology. Furthermore, the chemical heat storage technology can be subdivided into an adsorption system, a hydrogen storage alloy system, an organic reaction system, an inorganic reaction system, etc., depending on the chemical reaction used.

  As a conventional chemical heat storage device using a chemical reaction, one that stores heat by drying an adsorbent is known (for example, see Patent Document 1). In this type of chemical heat storage device, the heat storage material is used in the following two forms. A 1st form is a form which obtains cold using a thermal storage material, and is called what is called desiccant air conditioning. In the first embodiment, air is directly passed through the adsorbent layer, and humidified cold air is obtained by humidifying the resulting dry air. A 2nd form is a form which obtains heat using a thermal storage material. In the second embodiment, the humidified air is directly passed through the adsorbent layer, and the air is heated by the adsorption heat generated during the moisture adsorption of the adsorbent. Since the heated air becomes high temperature, for example, hot water can be obtained by heating water using this high temperature air. In the second embodiment, the heat storage material (adsorbent) is a solid material, and the water supplied to the heat storage material is supplied as water vapor.

  Patent Document 2 utilizes a reaction in which a solid inorganic hydrate (for example, calcium chloride dihydrate) reacts with water vapor to produce a solid inorganic hydrate (for example, calcium chloride hexahydrate). A chemical heat storage technique is disclosed. Patent Document 2 discloses that heat (condensation heat) generated by condensation of water vapor generated during heat storage is recovered by a heat pump that is a heat storage heat source. However, also in this case, the heat storage material (inorganic hydrate) is a solid material, and the water supplied to the heat storage material is supplied as water vapor.

Patent Document 3 discloses a chemical heating device that supplies water as a liquid to a solid alkaline earth metal oxide and reacts the alkaline earth metal oxide and water in a sealed container. . In this apparatus, moisture supplied to the heat storage material (alkaline earth metal oxide) is supplied as liquid water, but the heat storage material is a solid material.
JP 2001-255088 A Japanese Patent Publication No. 7-6708 JP-A-8-337773

  By the way, when using a solid thing as a heat storage material, the space | gap is formed in the inside of a heat storage material, and there exists a subject that the heat storage amount per unit volume will reduce by the part of a space | gap. Therefore, the inventor of the present application considered that the heat storage material after heat storage is in a solid-liquid coexistence state or liquid phase state, and supplies heat of liquid to the heat storage material in the solid-liquid coexistence state or liquid phase state during heat dissipation. .

However, if water is sprayed from above on the heat storage material in the solid-liquid coexistence state or the liquid phase state, the reaction proceeds near the interface (liquid surface) of the heat storage material, but the heat storage material is usually more specific than water. Therefore, water is not sufficiently supplied below the interface of the heat storage material, and the reaction becomes insufficient. Therefore, there is a problem that it is difficult to obtain a sufficient heat radiation amount without releasing all the heat stored in the heat storage material.

  The present invention has been made in view of such points, and the object of the present invention is to improve the heat radiation amount in a chemical heat storage device that supplies liquid water to a heat storage material in a solid-liquid coexistence state or a liquid phase state. There is to plan.

  The chemical heat storage device according to the present invention has a heat storage material that has a specific gravity greater than that of water in a liquid phase and can store or dissipate heat by performing a reversible reaction involving desorption of water. Sometimes a heat accumulator having a heat accumulator that stores in a solid-liquid coexistence state or a liquid phase state, a condenser that condenses water vapor and stores condensed water, and the heat accumulator in the heat accumulator is heated during the heat accumulating step. And a supply path for supplying water in the condenser from the lower part of the heat storage tank to the heat storage tank during the heat dissipation process. It is.

  In the chemical heat storage device, the supply of water from the supply path is stopped before the water supplied from the supply path rises in the heat storage tank and reaches the interface of the heat storage material during the heat dissipation process. It may be a thing.

  In addition, the chemical heat storage device is configured so that, during the heat radiation process, the water supplied from the supply path is formed in the heat storage tank before the streaks of water extending in the vertical direction reaching the interface of the heat storage material. The supply of water from the road may be stopped.

  The heat storage tank may include a bottom plate formed with a plurality of holes for introducing water from the supply path into the heat storage tank.

  The heat storage material may be a calcium chloride hydrate in a solid state.

  The chemical heat storage device includes a valve provided in the supply path, a flow sensor for measuring a cumulative flow rate of water flowing through the supply path, and the valve when the cumulative flow rate measured by the flow sensor exceeds a predetermined amount. And a closing controller.

  The chemical heat storage device includes a heat exchange section disposed in the heat storage tank, includes a first heat medium circuit through which a heat medium flows, and a cooling section disposed in the condenser, and the heat medium flows through the heat storage section. A second heat medium circuit, and in the heat storage step, the heat storage material in the heat storage tank is heated by the heat medium supplied to the heat exchange unit, and the condensation is performed by the heat medium supplied to the cooling unit. Water vapor in the container may be condensed, and heat may be absorbed from the heat storage material in the heat storage tank by a heat medium supplied to the heat exchange unit in the heat dissipation step.

The chemical heat storage device, speed u ₁ after the acceleration of water rising the thermal storage tank, the supply time of water t, when the thickness of the heat storage material and is h, satisfy u ₁ × t <h It may be a thing.

  According to the present invention, a heat storage material in a solid-liquid coexistence state or a liquid phase state and liquid water can be mixed relatively evenly, and the amount of heat radiation can be improved.

  FIG. 1 is a configuration diagram of a chemical heat storage device 50 according to an embodiment of the present invention. The chemical heat storage device 50 includes a heat pump circuit 53, a first heat medium circuit 51, a second heat medium circuit 52, and a heat storage circuit 54.

  The heat pump circuit 53 includes a compressor 2 that compresses the refrigerant, a gas cooler 3 that dissipates the compressed refrigerant, an expansion mechanism 4 that expands the refrigerant after heat dissipation, and an evaporator 5 that evaporates the refrigerant after expansion. ing. Although the kind of refrigerant | coolant with which the heat pump circuit 53 is filled is not specifically limited, In this embodiment, the carbon dioxide is filled as a refrigerant | coolant. In the present embodiment, the refrigerant is compressed to a supercritical state by the compressor 2. The gas cooler 3 is configured by a heat exchanger that exchanges heat between the refrigerant circulating in the heat pump circuit 53 and the heat medium circulating in the first heat medium circuit 51. The expansion mechanism 4 only needs to expand the refrigerant. For example, the expansion mechanism 4 may be an expansion valve or a rotary expander. The evaporator 5 includes a heat exchanger that exchanges heat between the refrigerant circulating in the heat pump circuit 53 and the outside air and the heat medium circulating in the second heat medium circuit 52. Reference numeral 1 denotes a blower that supplies air to the evaporator 5.

  The heat storage circuit 54 includes a heat storage unit 9 having a heat storage tank 21, a condenser 10, a reflux path 22 that connects an upper part of the heat storage tank 21 and an upper part of the condenser 10, a lower part of the condenser 10, and heat storage. A supply path 23 connecting the lower portion of the tank 21 is provided.

  The heat storage tank 21 is composed of a sealed container excellent in heat insulation. The heat storage tank 21 stores a heat storage material 8 having a specific gravity larger than that of water not only in a solid state but also in a liquid state. In the present embodiment, calcium chloride hydrate is employed as the heat storage material 8. Calcium chloride hydrate reversibly desorbs water, absorbs heat by desorption of water, and dissipates heat by binding with water. As the heat storage material 8, calcium chloride hexahydrate which becomes calcium chloride tetrahydrate by desorption of water and further becomes calcium chloride dihydrate is particularly preferable.

The heat storage material 8 may use heat storage (latent heat storage) accompanying phase change in addition to heat storage (chemical heat storage) accompanying water desorption. In order to use latent heat storage, the heat storage material 8 preferably transitions from a solid phase state to a liquid phase state or a solid-liquid coexistence state at a temperature of less than 100 ° C. More specifically, calcium chloride hexahydrate is in a solid state at a temperature below room temperature as indicated by a point A in FIG. 4 before heat storage, but water is desorbed to remove calcium chloride tetrahydrate. When the heat is stored while shifting to, the mixed state (solid-liquid coexistence state) of calcium chloride dihydrate and calcium chloride hydrate melt (calcium chloride aqueous solution) as shown by point B in FIG. ) Thus, the heat storage material 8 stores heat by chemical heat storage and latent heat storage in addition to sensible heat storage. The ratio of the mass of calcium chloride to the total mass of the heat storage material 8 at the time of heat storage (CaCl ₂ mass concentration) is about 50% at the start of heat storage and is about 62% at the start of heat dissipation after heat storage.

The state of the heat storage material 8 does not need to change between point A and point B in FIG. 4. For example, in the state after heat storage, the calcium chloride hydrate melt becomes a simple substance (liquid phase state) and starts heat dissipation. The CaCl ₂ mass concentration at the time may be about 60%. Moreover, the heat storage material 8 may be in a mixed state of calcium chloride hexahydrate and calcium chloride tetrahydrate in the solid phase (CaCl ₂ mass concentration at the start of heat storage is, for example, about 55%). Alternatively, a part of calcium chloride hexahydrate may be dissolved in water before heat storage.

  The condenser 10 condenses the water vapor returning from the heat storage tank 21 through the reflux path 22 and stores the condensed water. In this embodiment, the condenser 10 consists of a tank. The supply path 23 is provided with a pump 12, a flow rate sensor 11, and an electromagnetic valve 13. Note that the valve of the supply passage 23 is not necessarily the electromagnetic valve 13. The chemical heat storage device 50 is provided with a controller 35 that controls the electromagnetic valve 13 based on the measurement value of the flow sensor 11.

  The supply path 23 supplies water from the lower part of the heat storage tank 21 into the heat storage tank 21. Here, the lower part of the heat storage tank 21 is a part below the intermediate position in the vertical direction of the stored heat-storage material 8 in the solid-liquid coexistence state or the liquid phase state. Although not limited to the bottom surface, in the present embodiment, the supply path 23 is configured to supply water from the bottom surface of the heat storage tank 21. Specifically, as schematically shown in FIG. 2, a plurality of holes 25 a are formed in the bottom plate 25 of the heat storage tank 21. The water from the supply path 23 is introduced into the heat storage tank 21 through these holes 25a. That is, the plurality of holes 25 a constitute a supply port of the supply path 23 that opens into the heat storage tank 21. The plurality of holes 25a may be regularly arranged in a matrix shape or a zigzag shape, or may be irregularly arranged.

  Although the details will be described later, the supply path 23 is supplied to the interface 8 of the heat storage material 8 as the supplied water rises in the heat storage tank 21 (surface that is formed by gravity and contacts the air in the heat storage tank 21). Stop water supply before reaching. That is, the supply path 23 supplies water so that the supplied water sufficiently reaches the interface 8 a of the heat storage material 8 after sufficiently reacting with the heat storage material 8. If the amount of water supplied from the supply path 23 is large or the supply speed is too fast, a part of the supplied water reaches the interface 8a without reacting with the heat storage material 8. As a result, as shown in the virtual diagram of FIG. 3, a streak 30 a of water extending in the vertical direction reaching the interface 8 a is formed inside the heat storage tank 21. In this embodiment, the supply path 23 ends the supply of water before the water streaks 30a are formed so that such water streaks 30a are not formed.

ｕ₁：水の加速後の速度［ｍ／ｓ］ ｕ₀：水の噴出速度［ｍ／ｓ］
ρ_∞：蓄熱材密度［ｋｇ／ｍ³］ ρ：水の密度［ｋｇ／ｍ³］
ｇ：重力加速度［ｍ／ｓ²］ ｈ：蓄熱材の層厚［ｍ］
から求められる、浮力によって加速された後の水の速度ｕ₁と、所定の供給量を供給する
時間ｔ（例えば３０ｓ）との積が、蓄熱材８の層厚ｈよりも小さくなるようにまず水の噴出速度ｕ₀を決定し、これに基づいて孔２５ａの数および直径を決定すればよい。すなわ
ち、水の加速後の速度ｕ₁［ｍ／ｓ］×供給時間ｔ［ｓ］＜蓄熱材層の層厚ｈ［ｍ］とい
う不等式が満たされるように水の噴出速度ｕ₀並びに孔２５ａの数および直径を決定すれ
ば、理論上、供給した水が蓄熱材８の界面８ａに達する前に水の供給を終了することができる。水の噴出速度を決定する際の供給時間ｔとしては、仮の目標時間（例えば１８００ｓ）を使用すればよい。なお、実際には、種々の外乱もあり得るので、必ずしも上記不等式を満たさなくても、供給した水が蓄熱材８の界面８ａに達する前に水の供給を終了することができる場合もある。 In the present embodiment, the supply amount and supply speed of water are determined by the flow rate of water flowing through the supply path 23, the number and diameter of the holes 25 a of the heat storage tank 21, and the layer thickness of the heat storage material 8. The diameter of the hole 25a may be uniform or non-uniform. When the diameter of the hole 25a is not uniform, the average diameter of the hole 25a may be used for the calculation. Regarding the number and diameter of the holes 25a, for example,

u ₁ : Speed after water acceleration [m / s] u ₀ : Water ejection speed [m / s]
ρ _∞ : Thermal storage material density [kg / m ³ ] ρ: Water density [kg / m ³ ]
g: Gravitational acceleration [m / s ² ] h: Thermal storage material layer thickness [m]
_First , the product of the speed u ₁ of water after being accelerated by buoyancy and the time t (for example, 30 s) for supplying a predetermined supply amount, which is obtained from the above, is smaller than the layer thickness h of the heat storage material 8 The water ejection speed u ₀ may be determined, and the number and diameter of the holes 25a may be determined based on this. That is, the water ejection speed u _{0 and the} hole 25a are set so that the inequality of the speed u ₁ [m / s] after the acceleration of water × the supply time t [s] <the layer thickness h [m] of the heat storage material layer is satisfied. If the number and diameter are determined, the supply of water can theoretically be terminated before the supplied water reaches the interface 8a of the heat storage material 8. A provisional target time (for example, 1800 s) may be used as the supply time t when determining the water ejection speed. In practice, there may be various disturbances, so the supply of water may be terminated before the supplied water reaches the interface 8a of the heat storage material 8 without necessarily satisfying the above inequality.

In order to prevent the formation of the water streaks 30a reaching the interface 8a of the heat storage material 8, the water ejection speed u ₀ is preferably as slow as possible from the above inequality, but the ejection from all the holes 25a. From the viewpoint of making the speed the same, the water ejection speed u ₀ is 2Q / A [m / s] (Q
: The flow rate of water [m ³ / s], and A: the area [m ² ] of the bottom plate 25) or more.

In summary, it can be seen that the range of the water ejection speed u ₀ only needs to satisfy the following equation.

  The first heat medium circuit 51 is a circuit that supplies heat to the heat storage material 8 during the heat storage process and flows a heat medium that absorbs heat from the heat storage material 8 during the heat dissipation process. In this embodiment, water is used as the heat medium. In the first heat medium circuit 51, the first circulation pump 14, the first three-way valve 16, the second three-way valve 6, the gas cooler 3, the third three-way valve 7, and the fourth three-way valve 17 are sequentially connected in an annular manner. The main circuit 51a is provided. A heat exchange unit 20 disposed in the heat storage tank 21 is provided between the third three-way valve 7 and the fourth three-way valve 17. In addition, the heat exchange part 20 should just be heat-exchanged with the thermal storage material 8 in the thermal storage tank 21, and does not necessarily need to be provided in the thermal storage tank 21 inside. The heat exchanging unit 20 may heat or cool the heat storage tank 21 from the outside of the heat storage tank 21. The first heat medium circuit 51 includes an introduction circuit 51b for introducing water from the second three-way valve 6 to the main circuit 51a, a derivation circuit 51c for deriving water of the main circuit 51a from the third three-way valve 7, It has. The introduction circuit 51b is provided with a pump 15 that conveys water toward the main circuit 51a. Further, the first heat medium circuit 51 is provided with a passage 51 d that connects the first three-way valve 16 and the fourth three-way valve 17.

  The second heat medium circuit 52 is a circuit in which a heat medium for cooling the water vapor in the condenser 10 circulates during the heat storage process. In this embodiment, water is used as the heat medium. To the second heat medium circuit 52, the second circulation pump 18, the cooling unit 24 disposed in the condenser 10, and the evaporator 5 are sequentially connected in an annular shape. The cooling unit 24 is sufficient if it cools the water vapor in the condenser 10, and is not necessarily disposed inside the condenser 10. The cooling unit 24 may be installed outside the condenser 10.

  Next, the operation of the chemical heat storage device 50 will be described.

  First, the heat storage process will be described with reference to FIG. In the heat storage process, heat is stored in the heat storage material 8 using the heat pump circuit 53 as a heat source.

  In the heat pump circuit 53, the refrigerant discharged from the compressor 2 radiates heat with the gas cooler 3, and the refrigerant after heat dissipation expands with the expansion mechanism 4. The expanded refrigerant evaporates in the evaporator 5 and returns to the compressor 2.

  In the first heat medium circuit 51, the first circulation pump 14 operates and the pump 15 stops operating. The water discharged from the first circulation pump 14 sequentially passes through the first three-way valve 16 and the second three-way valve 6 and is heated in the gas cooler 3. The heated water (for example, water at about 80 ° C.) passes through the third three-way valve 7 and then radiates heat to the heat storage material 8 in the heat exchange unit 20. The water after heat dissipation passes through the fourth three-way valve 17 and returns to the first circulation pump 14.

  In the second heat medium circuit 52, the water cooled by the evaporator 5 passes through the second circulation pump 18 and is supplied to the cooling unit 24 of the condenser 10. The water supplied to the cooling unit 24 cools the water vapor in the condenser 10 and condenses the water vapor. The water that has flowed out of the cooling unit 24 is cooled again by the evaporator 5 and the above-described operation is repeated.

In the heat storage circuit 54, the pump 12 does not operate and the electromagnetic valve 13 is closed. In the heat accumulator 9, the heat storage material 8 is heated by the hot water flowing through the heat exchange unit 20. As a result, the calcium chloride hexahydrate (heat storage material) in the heat storage tank 21 absorbs heat to become calcium chloride tetrahydrate, and moisture is released from the heat storage material 8 as water vapor. The water vapor generated in the heat storage tank 21 is supplied to the condenser 10 through the reflux path 22 where it is cooled by the cooling unit 24 and condensed. The condensed water is stored in the condenser 10. The amount of water vapor transferred from the heat storage tank 21 to the condenser 10 is regulated by a valve (not shown) provided in the reflux path 22, so that the heat storage material 8 finally has calcium chloride dihydrate and calcium chloride. It becomes a mixed state (solid-liquid coexistence state) with the hydrate melt. In addition, you may make it easy to evaporate a water | moisture content from the thermal storage material 8 by providing a vacuum pump in the reflux path 22, and decompressing the inside of the thermal storage 9.

  Next, the heat dissipation process will be described with reference to FIG. The heat dissipation step is a step of heating the water of the first heat medium circuit 51 using the heat storage of the heat accumulator 9 and using the water for hot water supply or the like.

  In the heat dissipation process, the heat pump circuit 53 and the second heat medium circuit 52 are not operated.

  In the heat storage circuit 54, the solenoid valve 13 is opened and the pump 12 is driven. Water in the condenser 10 is supplied from the supply path 23 to the heat storage tank 21. As a result, water is supplied from the bottom of the heat storage tank 21. Since the supplied water has a density lower than that of the heat storage material 8, it rises due to a density difference with the heat storage material 8. As a result, the supplied water rises in the heat storage tank 21 while reacting with the heat storage material 8. At this time, reaction heat is obtained by a hydration reaction between calcium chloride and water contained in the heat storage material 8. The water rising in the heat storage tank 21 may generate a vortex as it rises. In that case, the heat storage material 8 is agitated by this vortex, and becomes easier to mix with water more uniformly.

  The accumulated flow rate of the water supplied from the condenser 10 to the heat storage tank 21 is measured by the flow rate sensor 11. In this embodiment, when a predetermined amount of water is supplied, that is, when the cumulative flow rate measured by the flow sensor 11 exceeds a predetermined amount, the electromagnetic valve 13 is closed by the controller 35 and the water for the heat storage tank 21 is closed. Supply is stopped. Here, the “predetermined amount” is an amount such that the supplied water is terminated before the supplied water reaches the interface 8a of the heat storage material 8, as described above. The amount is slightly smaller than the amount reaching the interface 8a of the heat storage material 8. In other words, the “predetermined amount” is an amount such that the water streaks 30 a are not formed in the heat storage tank 21. This “predetermined amount” may be set in advance by simulation or the like, or may be set by experiment or the like.

  In the first heat medium circuit 51, the operation of the first circulation pump 14 is stopped, and the pump 15 of the introduction circuit 51b is driven. In the first heat medium circuit 51, the water supplied from the pump 15 passes through the second three-way valve 6, the first three-way valve 16, the passage 51 d, and the fourth three-way valve 17 in this order, and in the heat storage tank 21. Into the heat exchange section 20. The water flowing into the heat exchanging unit 20 is heated by the heat storage material 8 and becomes warm water (for example, warm water of about 95 ° C.). This hot water flows out of the heat exchanging section 20, passes through the third three-way valve 7, is guided to the derivation circuit 51c, and is then used as hot water or the like. On the other hand, the heat storage material 8 is cooled by exchanging heat with water in the heat exchanging unit 20, thereby returning to calcium chloride hexahydrate in a solid state.

  As described above, according to the chemical heat storage device 50 according to the present embodiment, the lower portion of the heat storage tank 21 with respect to the heat storage tank 21 storing the solid-liquid coexisting heat storage material 8 having a specific gravity greater than that of water. We decided to supply water. For this reason, the supplied water rises in the heat storage tank 21 while reacting with the heat storage material 8, so that the water and the heat storage material 8 are mixed relatively uniformly in the heat storage tank 21. Therefore, unlike the method of spraying water from above on the interface 8a of the heat storage material 8, the water and the heat storage material 8 can be reacted well, and the amount of heat radiation can be improved.

FIG. 7A shows a heat storage tank in which a heat storage material 8 (solid-liquid coexistence state of melt and calcium chloride dihydrate) obtained by heating calcium chloride tetrahydrate is stored in a heat storage tank 21. It is a figure which shows the temperature change of the thermal storage material 8 when water is supplied from the lower part of 21. On the other hand, FIG.7 (b) has stored the thermal storage material 8 (solid-liquid coexistence state of a melt and calcium chloride dihydrate) obtained by heating calcium chloride tetrahydrate in the thermal storage tank 21, It is a figure which shows the temperature change of the thermal storage material 8 when water is sprayed from upper direction. In either case, the temperature of the heat storage material 8 rises due to the water supply, and then the heat storage material 8 is cooled by the heat exchange unit 20, so that the temperature is lowered. However, as apparent from comparing FIGS. 7 (a) and 7 (b), the temperature rises more when water is supplied from the lower portion of the heat storage tank 21, and the temperature drops to a predetermined temperature accordingly. It takes a long time to extend the heat radiation time.

  In particular, according to the present embodiment, in the heat dissipation step, the supply of water is terminated before the water supplied to the lower portion of the heat storage tank 21 reaches the interface 8a of the heat storage material 8. According to the present embodiment, it is possible to prevent the water streak 30a extending in the vertical direction reaching the interface 8a from being formed inside the heat storage material 8. Therefore, the supplied water can be prevented from moving upward from the interface 8a of the heat storage material 8 without reacting with the heat storage material 8, and water and the heat storage material 8 can be reacted efficiently. That is, the water and the heat storage material 8 can be sufficiently reacted before the supplied water reaches the interface 8a. Therefore, it is possible to further improve the heat radiation amount.

  FIG. 8 is a graph showing the change over time in the conversion rate of the heat storage material 8 to calcium chloride hexahydrate when the water supply rate (spout rate) is changed. As can be seen from FIG. 8, the conversion rate is greater when the water has not reached the interface 8a when the supply of water is completed, compared to when the water has reached the interface 8a.

  In the present embodiment, a plurality of holes 25a are formed in the bottom plate 25 of the heat storage tank 21, and water is supplied from these holes 25a. Therefore, water can be supplied relatively uniformly from the lower side of the heat storage material 8. Moreover, the comparatively simple structure of having the bottom plate 25 formed with a plurality of holes 25a can realize a suitable means for supplying water to the lower portion of the heat storage tank 21.

  In the present embodiment, the cumulative flow rate of water flowing through the supply path 23 is measured, and the supply of water is stopped based on the cumulative flow rate. That is, whether or not the supplied water reaches the interface 8a of the heat storage material 8 is estimated based on the accumulated flow rate of water in the supply path 23, and the water supply is stopped before the water reaches the interface 8a. Therefore, it is possible to know the timing of the water supply stop relatively accurately and easily, and to stop the water supply by a relatively simple method.

  In addition to the heat storage circuit 54, the chemical heat storage device 50 according to the present embodiment includes a first heat medium circuit 51 having a heat exchange unit 20 disposed in the heat storage tank 21, and a cooling unit 24 disposed in the condenser 10. And a second heat medium circuit 52. Therefore, an excellent chemical heat storage device 50 that suitably uses the heat storage circuit 54 can be obtained.

<Modification>
In the embodiment, carbon dioxide is used as the refrigerant in the heat pump circuit 53, but the refrigerant is not limited to carbon dioxide. As the refrigerant, for example, a fluorocarbon refrigerant can be used. Moreover, in the said embodiment, although water is used as a heat medium of the 1st heat medium circuit 51 and the 2nd heat medium circuit 52, you may use heat media other than water, for example, antifreezing liquid, heat-medium oil, etc. The heat medium is not limited to a liquid but may be a gas.

Moreover, in the said embodiment, although the hydrate of calcium chloride is used as the thermal storage material 8, the material of the thermal storage material 8 is not necessarily limited to this. That is, the heat storage material of the present invention only needs to be in a solid phase state at the start of heat storage and be in a solid-liquid coexistence state or a liquid phase state at the start of heat dissipation, and other material systems having a large difference in water absorption relative to relative humidity A thing can also be used suitably. For example, the heat storage material 8 may be potassium bromide hexahydrate or the like. However, if the heat storage material 8 is a hydrate of calcium chloride, it can be obtained in large quantities at low cost, and thus the manufacturing cost can be reduced.

  The configuration for supplying water from the lower portion of the heat storage tank 21 into the heat storage tank 21 is not limited to the bottom plate 25 in which a plurality of holes 25a are formed as in the above embodiment. Further, the lower portion of the heat storage tank 21 is not necessarily limited to the bottom surface of the heat storage tank 21 and may be a portion slightly above the bottom surface. For example, as shown in FIG. 9, the tube 26 in which a plurality of holes 26 a are formed may be disposed above the bottom plate 25. In this case, the tube 26 may be disposed so as to be in contact with the bottom plate 25, but may be disposed slightly apart from the bottom plate 25. In this modification, water is supplied from the hole 26 a of the pipe 26 to the heat storage material 8 in the heat storage tank 21.

  In the above embodiment, whether or not the water supplied to the heat storage tank 21 has reached the interface 8a of the heat storage material 8 is estimated based on the flow rate of the water flowing through the supply path 23, but is estimated using another method. You may do it.

  For example, the above estimation may be performed based on the water supply time. For example, the electromagnetic valve 13 may be closed when a predetermined time has elapsed from the start of water supply so that the supply of water is stopped before the supplied water reaches the interface 8a of the heat storage material 8.

  Further, when the reaction between the heat storage material 8 and water proceeds, the temperature of the heat storage material 8 changes. Therefore, the above estimation may be performed based on the temperature of the heat storage material 8. For example, when a temperature sensor for measuring the temperature of the heat storage material 8 is provided, and the temperature of the heat storage material 8 reaches a predetermined temperature so that the supply of water is stopped before the supplied water reaches the interface 8a of the heat storage material 8. The electromagnetic valve 13 may be closed.

  Further, when the reaction between the heat storage material 8 and water proceeds, the position of the interface 8a of the heat storage material 8 changes. Therefore, the above estimation may be performed based on the position of the interface 8a of the heat storage material 8. For example, a liquid level sensor that detects the position of the interface 8a of the heat storage material 8 is provided in the heat storage tank 21, and the supply of water is stopped before the supplied water reaches the interface 8a of the heat storage material 8. When the position becomes a predetermined position, the electromagnetic valve 13 may be closed.

  The present invention is useful for a chemical heat storage device that can be used in various fields such as refrigeration, air conditioning, and hot water supply.

1 is an overall configuration diagram of a chemical heat storage device according to an embodiment of the present invention. Perspective view of bottom plate of heat storage tank Virtual conceptual diagram for explaining the behavior of water in the heat storage tank Phase diagram showing changes in heat storage material Overall configuration diagram of chemical heat storage device during heat storage process Overall configuration diagram of chemical heat storage device during heat dissipation process (A) is a graph showing the temperature change of the heat storage material when water is supplied from the lower side of the heat storage material, (b) is a graph showing the temperature change of the heat storage material when water is sprayed from above the heat storage material. Graph showing change over time in conversion rate of heat storage material The perspective view of the lower part of the heat storage tank concerning a modification

Explanation of symbols

8 Heat storage material 8a Interface of heat storage material 9 Heat storage device 10 Condenser 11 Flow rate sensor 13 Solenoid valve 20 Heat exchange unit 21 Heat storage tank 22 Recirculation channel 23 Supply channel 24 Cooling unit 25 Bottom plate 25a Hole 35 Controller 50 Chemical heat storage device 51 First heat Medium circuit 52 Second heat medium circuit 53 Heat pump circuit 54 Heat storage circuit

Claims (9)

A heat storage material that has a specific gravity greater than that of water in the liquid phase and that can store or release heat by performing a reversible reaction with desorption of water is in a solid phase at the start of heat storage, or in a solid-liquid coexistence state or in a liquid phase at the start of heat dissipation A heat accumulator having a heat accumulator stored in
A condenser for condensing water vapor and storing the condensed water;
A reflux path for guiding water vapor generated by heating the heat storage material in the heat storage tank to the condenser during the heat storage process;
A supply path for supplying water in the condenser into the heat storage tank from a lower portion of the heat storage tank during a heat dissipation process;
A chemical heat storage device. The chemical heat storage device according to claim 1,
A chemical heat storage device in which water supply from the supply path is stopped before the water supplied from the supply path rises in the heat storage tank and reaches the interface of the heat storage material during the heat dissipation process. The chemical heat storage device according to claim 1,
During the heat dissipation process, the supply of water from the supply path is stopped before the water supplied from the supply path has a streak of water extending in the vertical direction reaching the interface of the heat storage material in the heat storage tank. Chemical heat storage device. In the chemical heat storage device according to any one of claims 1 to 3,
The said thermal storage tank is a chemical thermal storage apparatus provided with the baseplate in which the several hole for introducing the water from the said supply path into the said thermal storage tank was formed. In the chemical heat storage device according to any one of claims 1 to 3,
The said heat storage material is a chemical heat storage apparatus which is a hydrate of calcium chloride in a solid state. The chemical heat storage device according to claim 2 or 3,
A valve provided in the supply path;
A flow rate sensor for measuring a cumulative flow rate of water flowing through the supply path;
A controller that closes the valve when the cumulative flow rate measured by the flow rate sensor exceeds a predetermined amount;
A chemical heat storage device further comprising: In the chemical heat storage device according to any one of claims 1 to 3,
A first heat medium circuit having a heat exchanging portion disposed in the heat storage tank and through which the heat medium flows;
A second heat medium circuit having a cooling unit disposed in the condenser and through which the heat medium flows;
Further comprising
In the heat storage step, the heat storage material in the heat storage tank is heated by the heat medium supplied to the heat exchange unit, and the water vapor in the condenser is condensed by the heat medium supplied to the cooling unit,
A chemical heat storage device that absorbs heat from a heat storage material in the heat storage tank by a heat medium supplied to the heat exchange unit during a heat dissipation process. The chemical heat storage device according to claim 2,
The speed after the acceleration of water rising the thermal storage tank u _1, the supply time of the water t, when the thickness of the heat storage material and is h, the chemical heat storage device that satisfies u ₁ × t <h. The chemical heat storage device according to claim 2,
Water ejection speed u ₀ , heat storage material density ρ _∞ , water density ρ, gravity acceleration g, heat storage material layer thickness h, water supply time t, water flow rate Q, heat storage material When the area of the bottom plate in contact with is A,

A chemical heat storage device that meets the requirements.

Images