Water utilization system and chemical heat storage system

Abstract

To provide a water utilization system which enables liquid sending for sending water condensed in a condenser to an evaporator and liquid sending for circulating water in the evaporator while avoiding increase of the number of electric pumps, and to provide a chemical heat storage system.SOLUTION: A water utilization system includes a water utilization path 71 for supplying water W2 condensed by a condenser 41 to an evaporator 51. The water utilization path 71 includes: a first electric pump 72; an ejector 73; a pump suction passage 74 which causes the first electric pump 72 to suction water W1 in the evaporator 51; and an ejector suction passage 75 which causes the ejector 73 to suction the water W2 in the condenser 41 as suction fluid of the ejector 73. The water utilization path 71 includes: an ejector driving passage 76 for supplying the water W1 discharged by the first electric pump 72 to the ejector 73 as driving fluid of the ejector 73; and an evaporator liquid sending passage 77 for sending water discharged from the ejector 73 to the evaporator 51.SELECTED DRAWING: Figure 4

Description

[Technical field]

[0001] The present disclosure relates to a water utilization system and a chemical heat storage system. [Background technology]

[0002] As described in Patent Document 1, a chemical heat storage system is known in which water is used as a reaction medium for a chemical heat storage material. The chemical heat storage system includes an evaporator that generates water vapor and a condenser that condenses the water vapor. By sending the water condensed by the condenser to the evaporator, it becomes possible to reuse the water in the chemical heat storage system. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2022-040464 A Summary of the Invention [Problem to be solved by the invention]

[0004] In a chemical heat storage system, an electric pump is used to send water condensed in a condenser to an evaporator. On the other hand, from the viewpoint of increasing the water heating efficiency in the evaporator, it is preferable to circulate the water in the evaporator. However, if an additional electric pump is installed to circulate the water in the evaporator, for example, there is a risk that the electrical wiring will become complicated. [Means for solving the problem]

[0005] The water utilization system that solves the above problem is a water utilization system used for applications in which water is utilized within a chemical heat storage system, and includes an evaporator that generates water vapor to be used within the chemical heat storage system, a condenser that condenses the water vapor generated within the chemical heat storage system, and a water utilization path that supplies the water condensed by the condenser to the evaporator, wherein the water utilization path includes an electric pump, an ejector, a pump suction flow path that causes the electric pump to draw in one of the water in the evaporator and the water in the condenser, an ejector suction flow path that causes the ejector to draw in the other of the water in the evaporator and the water in the condenser as a suction fluid for the ejector, an ejector drive flow path that supplies water discharged from the electric pump to the ejector as a drive fluid for the ejector, and an evaporator liquid delivery flow path that delivers the water discharged from the ejector to the evaporator.

[0006] According to this configuration, the electric pump and the ejector can be used to send the water condensed in the condenser to the evaporator and to circulate the water in the evaporator. Effect of the Invention

[0007] The present disclosure has the effect of making it possible to send water condensed in a condenser to an evaporator and to circulate water within the evaporator without having to install an additional electric pump. [Brief description of the drawings]

[0008] [Figure 1] FIG. 1 is a schematic diagram showing a chemical heat storage system in a first embodiment. [Diagram 2] FIG. 2 is a schematic diagram illustrating the heat storage operation of the chemical heat storage system. [Diagram 3] FIG. 3 is a schematic diagram illustrating the regenerative operation of the chemical heat storage system. [Figure 4] FIG. 4 is a schematic diagram illustrating the water utilization operation of the water utilization system. [Diagram 5] FIG. 5 is a schematic diagram showing a main part of a chemical heat storage system in the second embodiment. [Figure 6]FIG. 6 is a schematic diagram illustrating the water utilization operation of the water utilization system. [Figure 7] FIG. 7 is a schematic diagram illustrating the water utilization operation of the water utilization system. [Figure 8] FIG. 8 is a flow diagram illustrating the flow of the water utilization operation. [Figure 9] FIG. 9 is a schematic diagram showing a main part of a chemical heat storage system in the third embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] (First embodiment) Hereinafter, a first embodiment of a water utilization system and a chemical heat storage system will be described with reference to the drawings.

[0010] <Overall configuration of chemical heat storage system and water utilization system> 1, the chemical heat storage system 11 includes a chemical heat storage reactor 21, a recovery vessel 31, a condenser 41, and an evaporator 51. The chemical heat storage system 11 can be used as a chemical heat pump that stores heat from an exhaust heat source HS and then releases heat at a temperature higher than that of the exhaust heat source HS. The chemical heat storage system 11 can send water vapor to a heating target 61 during heat release operation.

[0011] The chemical heat storage system 11 includes a water utilization system that utilizes water within the chemical heat storage system 11. The water utilization system includes an evaporator 51, a condenser 41, and a water utilization path 71 that supplies water condensed in the condenser 41 to the evaporator 51.

[0012] <Chemical heat storage reactor> The chemical heat storage reactor 21 has a chemical heat storage material HM with water as a reaction medium in the chemical heat storage system 11. That is, the chemical heat storage material HM undergoes a dehydration reaction during the heat storage operation of the chemical heat storage system 11, and undergoes a hydration reaction during the heat dissipation operation of the chemical heat storage system 11. The chemical heat storage material HM is preferably a powdered material. The chemical heat storage material HM may be composed of only a chemical heat storage material that undergoes a dehydration reaction and a hydration reaction, or may be a material in which the chemical heat storage material is bound with a water vapor permeable binder such as a water vapor permeable resin. Examples of the chemical heat storage material include alkaline earth metal halides. The chemical heat storage material HM may be one type or a combination of multiple types.

[0013] The dehydration and hydration reactions of calcium chloride, which is a type of chemical heat storage material, are represented by, for example, the following formula (A). CaCl 2 H 2 O+H 2 O⇔CaCl 2 2H 2 O···(A) The chemical heat storage reactor 21 includes a first heat exchanger 22 that is provided so as to be able to exchange heat with the chemical heat storage material HM. The chemical heat storage reactor 21 generates saturated steam in the flow path of the first heat exchanger 22 by utilizing heat generated from the chemical heat storage material HM. The chemical heat storage reactor 21 includes a first container 23 that accommodates the chemical heat storage material HM and the first heat exchanger 22. The first container 23 of the chemical heat storage reactor 21 is configured so that water vapor used in the hydration reaction of the chemical heat storage material HM can be introduced. In addition, the first container 23 of the chemical heat storage reactor 21 is configured so that water vapor generated by the dehydration reaction of the chemical heat storage material HM is discharged.

[0014] Examples of the first heat exchanger 22 of the chemical heat storage reactor 21 include a fin-tube type heat exchanger, a finless heat exchanger, etc. As for the heat exchanger described below, a similar heat exchanger can be used unless otherwise specified.

[0015] <Collector> The recovery device 31 has an absorbent material LM that absorbs water vapor. The recovery device 31 recovers water vapor generated from the chemical heat storage material HM of the chemical heat storage reactor 21 by the absorbent material LM. The recovery device 31 includes a second heat exchanger 32 that is provided so as to be able to exchange heat with the absorbent material LM, and a second container 33 that accommodates the absorbent material LM and the second heat exchanger 32.

[0016] The absorbent LM is used to lower the temperature at which the chemical heat storage material HM undergoes a dehydration reaction. By using the absorbent LM, it is possible to promote the dehydration reaction of the chemical heat storage material HM and store heat even with exhaust heat at a lower temperature. A substance capable of undergoing a dehydration reaction at the temperature of the exhaust heat source HS is used as the absorbent LM. This makes it possible to regenerate the absorbent LM by utilizing the heat of the exhaust heat source HS.

[0017] The equilibrium vapor pressure VP2C of the absorbent LM at the temperature of the cooling source CS is lower than the equilibrium vapor pressure VP1H of the chemical heat storage material HM at the temperature of the exhaust heat source HS, so that the dehydration reaction of the chemical heat storage material HM can be favorably promoted. On the other hand, it is preferable that the equilibrium vapor pressure VP2H of the absorbent LM at the temperature of the exhaust heat source HS is higher than the equilibrium vapor pressure VP1H of the chemical heat storage material HM at the temperature of the exhaust heat source HS. Since such an absorbent LM is easier to dehydrate than the chemical heat storage material HM, it can be efficiently used for the next heat storage operation by regenerating the absorbent LM using the exhaust heat source HS. In addition, it is preferable that the equilibrium vapor pressure VP2H of the absorbent LM at the temperature of the exhaust heat source HS is higher than the equilibrium vapor pressure VP3C of water at the temperature of the cooling source CS. As a result, the absorbent LM can be efficiently regenerated by condensing the water vapor generated by heating the absorbent LM with the exhaust heat source HS by cooling with the cooling source CS.

[0018] Examples of the absorbent LM include zeolite, lithium hydroxide, magnesium sulfate, strontium bromide, activated carbon, porous metal complexes (MOF), etc. The absorbent LM may be used alone or in combination of two or more kinds.

[0019] The dehydration and hydration reactions of strontium bromide, which is one type of absorbent material LM, are represented, for example, by the following formula (B). SrBr 2 H 2 O+5H 2 O⇔SrBr 2 6H 2 O···(B) <Condenser> The condenser 41 condenses the water vapor generated from the absorbent LM. The condenser 41 also cools the recovery device 31. The condenser 41 includes a third heat exchanger 42 through which a cooling medium supplied from a cooling source CS flows, and a third container 43 that houses the third heat exchanger 42. The third heat exchanger 42 cools the water vapor flowing into the third container 43 of the condenser 41, thereby condensing it.

[0020] The condenser 41 is configured to supply water to the second heat exchanger 32 of the recovery device 31. The condenser 41 is configured to receive water that has passed through the second heat exchanger 32 of the recovery device 31. The condenser 41 has, for example, a nozzle 44 provided in a third container 43. The nozzle 44 can eject the water that has passed through the second heat exchanger 32 of the recovery device 31 into the third container 43. In the third container 43, the water may be cooled by utilizing flash evaporation of the water ejected from the nozzle 44. By setting the pressure condition in the third container 43 to a pressure condition lower than the equilibrium vapor pressure at the temperature of the water that has passed through the second heat exchanger 32 of the recovery device 31, the water can be cooled by utilizing flash evaporation.

[0021] <Evaporator> The evaporator 51 supplies water vapor to be reacted with the chemical heat storage material HM to the chemical heat storage reactor 21. The evaporator 51 includes a fourth heat exchanger 52 to which a heating medium is supplied from the exhaust heat source HS, and a fourth container 53 that houses the fourth heat exchanger 52. The fourth heat exchanger 52 of the evaporator 51 generates water vapor by heating water W1, which is an evaporation fluid.

[0022] <Water use route> The water use path 71 includes a first electric pump 72 and an ejector 73. The water use path 71 includes a pump suction flow path 74 that causes the first electric pump 72 to suck the water W1 in the evaporator 51, and an ejector suction flow path 75 that causes the ejector 73 to suck the water W2 in the condenser 41 as the suction fluid of the ejector 73. The water use path 71 includes an ejector drive flow path 76 that supplies the water W1 discharged from the first electric pump 72 to the ejector 73 as the drive fluid of the ejector 73. The water use path 71 includes an evaporator liquid delivery flow path 77 that delivers the water discharged from the ejector 73, i.e., the mixed water of the water W1 and the water W2, to the evaporator 51.

[0023] The first electric pump 72 of this embodiment is, for example, a non-positive-displacement pump such as a centrifugal pump. The ejector 73 can generate negative pressure inside when the driving fluid supplied thereto is discharged. The ejector 73 draws in a suction fluid different from the driving fluid by the negative pressure generated inside. The ejector 73 discharges the suction fluid together with the driving fluid. The ejector 73 includes a nozzle, a diffuser, and the like. When the water utilization path 71 is not in use, it is preferable to close the on-off valve provided in the ejector suction flow path 75. This can prevent backflow of water from the ejector 73 to the condenser 41.

[0024] <Flow path configuration> Next, a description will be given of the flow paths used in the heat storage operation, the regeneration operation, and the heat dissipation operation of the chemical heat storage system 11. First, a description will be given of the flow paths used in the heat storage operation of the chemical heat storage system 11.

[0025] 2, the chemical heat storage system 11 has a recovery steam flow path L1 that sends steam WV1 from the chemical heat storage reactor 21 to the recovery device 31. The chemical heat storage system 11 has a reactor heating flow path L2 that sends water W1 heated in the evaporator 51 to the first heat exchanger 22 of the chemical heat storage reactor 21 by the first electric pump 72, and a first evaporator flow path L3 that returns the water W1 that has passed through the first heat exchanger 22 to the evaporator 51.

[0026] The chemical heat storage system 11 has a recovery device cooling flow path L4 that sends the water W2 cooled in the condenser 41 to the second heat exchanger 32 of the recovery device 31 by the second electric pump 81, and a first condenser flow path L5 that returns the water W2 that has passed through the second heat exchanger 32 to the condenser 41. In this way, between the condenser 41 and the recovery device 31, there is a flow path that allows the water W2 cooled in the condenser 41 to be circulated to the second heat exchanger 32 of the recovery device 31.

[0027] Next, the flow paths used in the regenerating operation of the chemical heat storage system 11 will be described. 3, the chemical heat storage system 11 has a second condenser flow path L6 that sends water vapor WV2 from the recovery device 31 to the condenser 41. The chemical heat storage system 11 has a recovery device heating flow path L7 that sends the water W1 heated in the evaporator 51 to the second heat exchanger 32 of the recovery device 31 by the first electric pump 72, and a second evaporator flow path L8 that returns the water W1 that has passed through the second heat exchanger 32 to the evaporator 51.

[0028] The chemical heat storage system 11 is configured to be switchable between the collector cooling flow path L4 shown in Fig. 2 and the collector heating flow path L7 shown in Fig. 3. This allows for alternately storing heat in the chemical heat storage material HM using the collector cooling flow path L4 and regenerating the absorbent material LM using the collector heating flow path L7. Note that the collector cooling flow path L4 and the collector heating flow path L7 can be switched between by opening and closing a valve.

[0029] Next, the flow paths used for the heat dissipation operation of the chemical heat storage system 11 will be described. 1 and 4, the chemical heat storage system 11 has a reactor water vapor flow path L9 that sends water vapor WV3 generated in the evaporator 51 to the chemical heat storage reactor 21. As shown in Fig. 1, the chemical heat storage system 11 includes a steam supply flow path L10 that sends water vapor in the first heat exchanger 22 of the chemical heat storage reactor 21 to a heating target 61. The heating target 61 is not particularly limited. Examples of the heating target 61 include a steam generator.

[0030] <Operation of chemical heat storage system> Next, an example of the operation of the chemical heat storage system 11 will be described. (Heat storage operation of chemical heat storage system) 2, in the heat storage operation of the chemical heat storage system 11, the water vapor WV1 discharged from the chemical heat storage material HM of the chemical heat storage reactor 21 is recovered by the recovery device 31. In detail, the water vapor WV1 discharged from the chemical heat storage material HM of the chemical heat storage reactor 21 is sent to the recovery device 31 through a recovery water vapor flow path L1. The water W2 in the condenser 41 is sent to the second heat exchanger 32 of the recovery device 31 through a recovery device cooling flow path L4.

[0031] The water W2 sent to the second heat exchanger 32 of the recovery device 31 is returned to the condenser 41 through the first condenser flow path L5. The water W2 cooled in the condenser 41 in this manner is circulated between the condenser 41 and the second heat exchanger 32 of the recovery device 31 through the recovery device cooling flow path L4 and the first condenser flow path L5.

[0032] The water vapor WV1 discharged from the chemical heat storage material HM of the chemical heat storage reactor 21 is sent to the recovery vessel 31, whereby a dehydration reaction of the chemical heat storage material HM is carried out. Here, as the dehydration reaction of the chemical heat storage material HM progresses, the temperature of the chemical heat storage material HM decreases. When the temperature of the chemical heat storage material HM becomes lower than the temperature of the heating medium of the exhaust heat source HS, the water W1 heated by the evaporator 51 is circulated between the first heat exchanger 22 of the chemical heat storage reactor 21 and the evaporator 51 through the reactor heating flow path L2 and the first evaporator flow path L3. The evaporator 51 can heat the water W1 by supplying the heating medium from the exhaust heat source HS to the fourth heat exchanger 52 of the evaporator 51.

[0033] As described above, the dehydration reaction of the chemical heat storage material HM is advanced by heating the chemical heat storage material HM in the chemical heat storage reactor 21 using the exhaust heat source HS. The heat storage operation of the chemical heat storage system 11 can be stopped by closing the valve between the chemical heat storage reactor 21 and the recovery vessel 31.

[0034] (Regeneration operation of chemical heat storage system) 3, in the regeneration operation of the chemical heat storage system 11, the water vapor WV2 discharged from the absorbent LM of the recovery device 31 is condensed by the condenser 41. In detail, the water vapor WV2 discharged from the absorbent LM of the recovery device 31 is sent to the condenser 41 through the second condenser flow path L6. A cooling medium is supplied from the cooling source CS to the third heat exchanger 42 of the condenser 41. The regeneration operation of the chemical heat storage system 11 can be stopped by closing the valve between the recovery device 31 and the condenser 41.

[0035] (Heat dissipation operation of chemical heat storage system) As shown in Fig. 4, in the heat dissipation operation of the chemical heat storage system 11, a heating medium is supplied from the exhaust heat source HS to the fourth heat exchanger 52 of the evaporator 51, thereby generating water vapor WV3 in the evaporator 51. The water vapor WV3 generated in the evaporator 51 is sent to the chemical heat storage reactor 21 through the reactor water vapor flow path L9 shown in Fig. 1 and Fig. 4. As a result, a hydration reaction of the chemical heat storage material HM in the chemical heat storage reactor 21 occurs.

[0036] The water in the flow path of the first heat exchanger 22 of the chemical heat storage reactor 21 is heated by heat generated by the hydration reaction of the chemical heat storage material HM. This allows water vapor to be generated in the flow path of the first heat exchanger 22. The water vapor in the flow path of the first heat exchanger 22 is sent to the heating target 61 through the steam supply flow path L10 shown in Fig. 1. The heat dissipation operation of the chemical heat storage system 11 can be stopped by closing the valve between the evaporator 51 and the chemical heat storage reactor 21.

[0037] In the chemical heat storage system 11, it is preferable to send the water W1 heated in the evaporator 51 to the first heat exchanger 22 of the chemical heat storage reactor 21 through the reactor heating passage L2 before the heat dissipation operation.

[0038] (Water use operation of water use route) Next, the water utilization operation of the water utilization path 71 will be described. As shown in Fig. 4, the water utilization operation of the water utilization path 71 is performed during the heat dissipation operation of the chemical heat storage system 11. In the water utilization operation, the water W1 in the evaporator 51 is sucked into the first electric pump 72 through the pump suction flow path 74. The first electric pump 72 supplies the water W1 to the ejector 73 through the ejector drive flow path 76. At this time, the water W2 in the condenser 41 is sucked into the ejector 73 through the ejector suction flow path 75. The water W2 in the condenser 41 sucked into the ejector 73 is mixed with the water W1, which is the drive fluid of the ejector 73, and then discharged from the ejector 73. The water discharged from the ejector 73 (mixture of the water W1 and the water W2) is sent to the evaporator 51 through the evaporator liquid sending flow path 77. In this way, in the water utilization operation, the first liquid supply, which sends the water W2 condensed in the condenser 41 to the evaporator 51, and the second liquid supply, which circulates the water W1 in the evaporator 51, can be performed using the first electric pump 72 and the ejector 73.

[0039] <How to use the chemical heat storage system> The above-mentioned method of using the chemical heat storage system 11 includes a heat storage step of performing the heat storage operation, a regeneration step of performing the regeneration operation, and a heat dissipation step of performing the heat dissipation operation. The heat storage step and the heat dissipation step can be repeated alternately. The regeneration step can be performed after the heat storage step and before the next heat storage step is started. In the method of using the chemical heat storage system 11, it is possible to switch between a regeneration step of regenerating the absorbent material LM using the above-mentioned collector heating flow path L7 and a heat storage step of storing heat in the chemical heat storage material HM using the above-mentioned collector cooling flow path L4.

[0040] In the heat dissipation step of this embodiment, by performing the water utilization operation described above, the water W2 condensed in the condenser 41 can be reused in the evaporator 51, and the heating efficiency of the water W1 in the evaporator 51 can be increased by circulating the water in the evaporator 51.

[0041] <Action and Effects> The operation and effects of this embodiment will be described. (1-1) The water utilization system is used for utilizing water in the chemical heat storage system 11. The water utilization system includes an evaporator 51 that generates water vapor WV3 to be used in the chemical heat storage system 11, and a condenser 41 that condenses the water vapor WV2 generated in the chemical heat storage system 11. The water utilization system includes a water utilization path 71 that supplies water W2 condensed in the condenser 41 to the evaporator 51. The water utilization path 71 includes a first electric pump 72 and an ejector 73. The water utilization path 71 includes a pump suction flow path 74 that causes the first electric pump 72 to suck the water W1 in the evaporator 51, and an ejector suction flow path 75 that causes the ejector 73 to suck the water W2 in the condenser 41 as a suction fluid for the ejector 73. The water utilization path 71 includes an ejector drive flow path 76 that supplies the water W1 discharged from the first electric pump 72 to the ejector 73 as the driving fluid for the ejector 73, and an evaporator liquid delivery flow path 77 that delivers the water discharged from the ejector 73 to the evaporator 51.

[0042] According to this configuration, the first liquid delivery for delivering the water W2 condensed in the condenser 41 to the evaporator 51 and the second liquid delivery for circulating the water W1 in the evaporator 51 can be performed using the first electric pump 72 and the ejector 73. Therefore, it is possible to perform the first liquid delivery and the second liquid delivery without adding an electric pump. This makes it possible to avoid, for example, the complication of electrical wiring that accompanies the addition of an electric pump.

[0043] In addition, since the pump suction flow path 74 of the present embodiment is a flow path that causes the first electric pump 72 to suck the water W1 in the evaporator 51, it is possible to easily increase the flow rate in the second liquid transfer that circulates the water W1 in the evaporator 51 using the first electric pump 72. Therefore, it is possible to further increase the heating efficiency of the water W1 in the evaporator 51.

[0044] (1-2) The chemical heat storage system 11 includes a collector cooling flow path L4 that sends the water W2 cooled in the condenser 41 to the second heat exchanger 32 of the collector 31, and a collector heating flow path L7 that sends the water W1 heated in the evaporator 51 to the second heat exchanger 32 of the collector 31. The collector cooling flow path L4 and the collector heating flow path L7 are configured to be switchable. Note that the collector heating flow path L7 can also be changed so as to send the water vapor generated in the evaporator 51 to the second heat exchanger 32 of the collector 31.

[0045] In this case, the recovery device 31 can be cooled and heated by the water W2 passing through the recovery device cooling flow path L4, which is independent of the flow path of the cooling medium of the cooling source CS, and the water W1 passing through the recovery device heating flow path L7, which is independent of the flow path of the heating medium of the exhaust heat source HS. Therefore, in the second heat exchanger 32 of the recovery device 31, it is possible to prevent the heating medium of the exhaust heat source HS from mixing with the cooling medium of the cooling source CS. As a result, the system of the cooling source CS is not affected by the properties of the heating medium of the exhaust heat source HS. Also, in the second heat exchanger 32 of the recovery device 31, it is possible to prevent the cooling medium of the cooling source CS from mixing with the heating medium of the exhaust heat source HS. As a result, the system of the exhaust heat source HS is not affected by the properties of the cooling medium of the cooling source CS. Therefore, it is possible to maintain the system of the cooling source CS and the system of the exhaust heat source HS in an independent state at the site where the chemical heat storage system 11 is introduced.

[0046] (1-3) In the case where the heating medium of the exhaust heat source HS is supplied to the first heat exchanger 22 of the chemical heat storage reactor 21, the first heat exchanger 22 is affected by the properties and cleanliness of the heating medium of the exhaust heat source HS. As a result, for example, the first heat exchanger 22 may require a lot of work for maintenance. In contrast, the chemical heat storage system 11 of this embodiment further includes a reactor heating flow path L2 that sends the water W1 heated by the evaporator 51 to the first heat exchanger 22 of the chemical heat storage reactor 21. In this case, it is easy to stabilize the properties and ensure the cleanliness of the water W1 supplied to the first heat exchanger 22 of the chemical heat storage reactor 21. As a result, for example, it is possible to reduce the work of maintenance of the first heat exchanger 22 of the chemical heat storage reactor 21. Even when the water vapor generated by the evaporator 51 is supplied to the first heat exchanger 22 of the chemical heat storage reactor 21, the same action and effect can be obtained.

[0047] Second embodiment The second embodiment will be described focusing on the differences from the first embodiment. The same components as those in the first embodiment are denoted by the same reference numerals as those in the first embodiment, and the description thereof will be omitted.

[0048] 5, the water utilization path 71 in the water utilization system of the second embodiment further includes a bypass flow path 78. The bypass flow path 78 returns the water W1 discharged from the first electric pump 72 into the evaporator 51 without supplying it to the ejector 73. The bypass flow path 78 is connected to an evaporator liquid delivery flow path 77. The water utilization path 71 is configured to be switchable between the bypass flow path 78 and the ejector drive flow path 76. Switching between the bypass flow path 78 and the ejector drive flow path 76 can be performed by opening and closing a valve.

[0049] The water utilization system of this embodiment includes a flowmeter 79 that measures the flow rate of the water W1 returned to the evaporator 51 through the bypass flow path 78. The water utilization system includes a control unit (not shown) that switches between the bypass flow path 78 and the ejector drive flow path 76 based on the measurement result of the flowmeter 79. When the control unit determines that the flow rate measured by the flowmeter 79 is insufficient, the control unit switches from the bypass flow path 78 to the ejector drive flow path 76. At this time, the flowmeter 79 can measure the flow rate of water sent from the ejector 73 to the evaporator 51. The control unit can also be configured to switch from the bypass flow path 78 to the ejector drive flow path 76 when it is determined that the flow rate measured by the flowmeter 79 has changed from an insufficient state to a normal state. The control unit includes, for example, an input unit to which a signal from the flowmeter 79 is input, a storage unit that stores a preset threshold value, and an opening / closing control unit that controls the opening and closing of a valve based on the threshold value. The control unit can be configured with a processor, a memory, software, etc.

[0050] Next, the water utilization operation of the water utilization system will be described with reference to the flow chart of FIG. In the water usage operation, the first electric pump 72 is operated (step S11). In step S11, as shown in Fig. 6, the water W1 discharged from the first electric pump 72 is returned to the evaporator 51 through the bypass passage 78. By circulating the water W1 in the evaporator 51 in this manner, it becomes possible to efficiently heat the water W1 in the evaporator 51.

[0051] In step S12, it is determined whether or not the flow rate measured by flowmeter 79 is insufficient. If it is determined in step S12 that the flow rate measured by flowmeter 79 is insufficient (step S12: YES), the process proceeds to step S13. If it is not determined in step S12 that the flow rate measured by flowmeter 79 is insufficient (step S12: NO), step S12 is repeated.

[0052] The flow rate measured by the flowmeter 79 in step S12 corresponds to the amount of water fed by the first electric pump 72. The pressure on the suction side of the first electric pump 72 decreases as the amount of water W1 in the evaporator 51 decreases. This makes the amount of water W1 discharged from the first electric pump 72 unstable, and the amount of water fed by the first electric pump 72 decreases. In other words, based on the decrease in the flow rate measured by the flowmeter 79, it can be seen that the amount of water W1 in the evaporator 51 is decreasing.

[0053] In step S13, the ejector 73 is operated. More specifically, in step S13, as shown in Fig. 7, the water W1 discharged from the first electric pump 72 is supplied to the ejector 73, and the water W2 in the condenser 41 is supplied to the evaporator 51. As the amount of the water W1 in the evaporator 51 increases, the discharge of the water W1 from the first electric pump 72 becomes stable. As a result, the flow rate of the water W1 measured by the flow meter 79 increases.

[0054] In step S14, it is determined whether the flow rate measured by flowmeter 79 is normal. That is, in step S14, it is determined whether the decrease in the flow rate measured by flowmeter 79 has been resolved and a flow rate exceeding a predetermined value is secured. If it is determined in step S14 that the flow rate measured by flowmeter 79 is normal (step S14: YES), the process proceeds to step S15. If it is determined in step S14 that the flow rate measured by flowmeter 79 is not normal (step S14: NO), step S14 is repeated.

[0055] In step S15, the ejector 73 is stopped. That is, as shown in FIG. 6, the water W1 discharged from the first electric pump 72 is returned into the evaporator 51 through the bypass passage 78. After step S15, the process proceeds to step S12. Such a series of water use operations is performed during the heat dissipation operation. The water use operation is stopped together with the stop of the heat dissipation operation.

[0056] The operation and effects of the second embodiment will be described. (2-1) The water utilization system of the second embodiment also provides the same effects as those described in section (1-1) of the first embodiment. The chemical heat storage system 11 of the second embodiment also provides the same effects as those described in sections (1-2) and (1-3) of the first embodiment.

[0057] (2-2) The water utilization path 71 in the water utilization system of the second embodiment further includes a bypass flow path 78. The bypass flow path 78 returns the water W1 discharged from the first electric pump 72 into the evaporator 51 without supplying it to the ejector 73. The water utilization path 71 is configured to be able to switch between the bypass flow path 78 and the ejector driving flow path 76. In this case, it is possible to save the power of the first electric pump 72 by operating the ejector 73 only when it is necessary to supply the water W2 in the condenser 41 to the evaporator 51 using the ejector 73. Therefore, the first liquid supply for sending the water W2 condensed in the condenser 41 to the evaporator 51 and the second liquid supply for circulating the water W1 in the evaporator 51 can be efficiently performed.

[0058] (2-3) The water utilization system further includes a flowmeter 79 that measures the flow rate of water W1 returned into the evaporator 51 through the bypass flow path 78. The water utilization system further includes a control unit that switches between the bypass flow path 78 and the ejector drive flow path 76 based on the measurement result of the flowmeter 79. When the control unit determines that the flow rate measured by the flowmeter 79 is insufficient, it switches from the bypass flow path 78 to the ejector drive flow path 76. In this case, switching from the bypass flow path 78 to the ejector drive flow path 76 can be easily performed at an appropriate timing.

[0059] Third embodiment The third embodiment will be described focusing on the differences from the first embodiment. The same components as those in the first embodiment are denoted by the same reference numerals as those in the first embodiment, and the description thereof will be omitted.

[0060] 9, a water utilization path 71 in the water utilization system of the third embodiment differs from that of the first embodiment in the connection between a pump suction passage 74 and an ejector suction passage 75. The pump suction passage 74 of the third embodiment causes the first electric pump 72 to suck water W2 in the condenser 41. The ejector suction passage 75 of the third embodiment causes the ejector 73 to suck water W1 in the evaporator 51 as a suction fluid for the ejector 73.

[0061] The water utilization path 71 includes an ejector drive flow path 76 that supplies water W2 discharged from the first electric pump 72 to the ejector 73 as a driving fluid for the ejector 73, and an evaporator liquid delivery flow path 77 that delivers the water discharged from the ejector 73 to the evaporator 51.

[0062] In the water utilization operation of the water utilization system of the third embodiment, the water W2 in the condenser 41 is sucked into the first electric pump 72 through the pump suction passage 74. The first electric pump 72 supplies water W1 to the ejector 73 through the ejector drive passage 76. At this time, the water W1 in the evaporator 51 is sucked into the ejector 73 through the ejector suction passage 75. The water W1 in the evaporator 51 sucked into the ejector 73 is mixed with water W2, which is the driving fluid of the ejector 73, and then discharged from the ejector 73. The water discharged from the ejector 73 (mixture of water W1 and water W2) is sent to the evaporator 51 through the evaporator liquid sending passage 77. In this way, in the water utilization operation, the first liquid supply, which sends the water W2 condensed in the condenser 41 to the evaporator 51, and the second liquid supply, which circulates the water W1 in the evaporator 51, can be performed using the first electric pump 72 and the ejector 73.

[0063] In the water utilization operation of the water utilization system of the third embodiment, the water W1 in the evaporator 51 can be circulated only when the first liquid delivery in which the water W2 condensed in the condenser 41 is delivered to the evaporator 51 is performed.

[0064] The operation and effects of the third embodiment will be described. (3-1) The water utilization system of the third embodiment also provides the same effects as those described in section (1-1) of the first embodiment. The chemical heat storage system 11 of the second embodiment also provides the same effects as those described in sections (1-2) and (1-3) of the first embodiment.

[0065] <Example of change> The above embodiment may be modified as follows: The above embodiment and the following modified examples may be implemented in combination with each other to the extent that there is no technical contradiction.

[0066] In the second embodiment, the flow meter 79 may be omitted, and a level gauge may be provided to measure the amount of water in the evaporator 51. That is, the control unit of the water utilization system may be configured to switch between the bypass flow path 78 and the ejector drive flow path 76 based on the measurement result of the level gauge. For example, when it is determined that the amount of liquid measured by the level gauge is insufficient, the control unit switches from the bypass flow path 78 to the ejector drive flow path 76. Even in this case, the same effects as those described in section (2-3) of the second embodiment above can be obtained.

[0067] In the water utilization system of the second embodiment, the bypass flow passage 78 and the ejector drive flow passage 76 can be switched manually. In the water utilization system of the third embodiment, a liquid level gauge for measuring the amount of water in the evaporator 51 may be provided, and the first electric pump 72 may be operated based on the amount of water measured by the liquid level gauge.

[0068] In the above-described chemical heat storage system 11, as shown in FIG. 2, the water W1 heated in the evaporator 51 is supplied to the first heat exchanger 22 of the chemical heat storage reactor 21. However, the system can be modified so that the heating medium of the exhaust heat source HS is supplied to the first heat exchanger 22 of the chemical heat storage reactor 21.

[0069] 3, the chemical heat storage system 11 is provided with a recovery device heating flow path L7 that sends the water W1 heated in the evaporator 51 to the second heat exchanger 32 of the recovery device 31, but this flow path may be omitted. In other words, the system may be modified so that the heating medium of the exhaust heat source HS is supplied to the second heat exchanger 32 of the recovery device 31.

[0070] In the heat storage operation of the above-mentioned chemical heat storage system 11, the recovery of the water vapor WV1 generated from the chemical heat storage material HM can also be performed using the condenser 41 and the recovery device 31. That is, in the above-mentioned heat storage method, the heat storage step of performing a dehydration reaction of the chemical heat storage material HM may include a condenser operation step and a recovery device operation step performed after the condenser operation step. In the condenser operation step, the water vapor WV1 generated from the chemical heat storage material HM is introduced into the condenser 41. In the recovery device operation step, the water vapor WV1 generated from the chemical heat storage material HM is introduced into the recovery device 31.

[0071] The water utilization system can also be applied to chemical heat storage systems other than the chemical heat storage system 11 described above. [Explanation of symbols]

[0072] 11…Chemical heat storage system 21...Chemical heat storage reactor 31...Collector 41…Condenser 51...Evaporator 71...Water use route 72…First electric pump 73…Ejector 74…Pump suction passage 75...Ejector suction passage 76...Ejector drive passage 77...Evaporator liquid supply channel 78...Bypass flow path 79…Flow meter HM…Chemical heat storage material LM: Absorbing material W1, W2…Water WV1, WV2, WV3...Water vapor

Claims

1. A water utilization system used for utilizing water in a chemical heat storage system, an evaporator for generating water vapor for use in the chemical heat storage system; A condenser that condenses water vapor generated in the chemical heat storage system; a water utilization path that supplies water condensed in the condenser to the evaporator; The water utilization route is An electric pump, An ejector, a pump suction passage for sucking one of the water in the evaporator and the water in the condenser into the electric pump; an ejector suction flow passage for sucking the other of the water in the evaporator and the water in the condenser into the ejector as a suction fluid of the ejector; an ejector driving flow passage that supplies water discharged from the electric pump to the ejector as a driving fluid for the ejector; an evaporator liquid delivery passage that delivers the water ejected from the ejector to the evaporator.

2. the pump suction flow path is a flow path for sucking water in the evaporator into the electric pump, The water utilization system according to claim 1 , wherein the ejector suction passage is a passage for sucking water in the condenser into the ejector.

3. The water utilization route is a bypass flow path for returning water discharged from the electric pump to the evaporator without supplying the water to the ejector, The water utilization system according to claim 2 , wherein the bypass flow path and the ejector drive flow path are switchable.

4. a flow meter that measures a flow rate of the water returned into the evaporator through the bypass passage, or a liquid level meter that measures an amount of water in the evaporator; a control unit that switches between the bypass flow path and the ejector driving flow path based on a measurement result of the flow meter or the liquid level gauge, The control unit is The water utilization system according to claim 3 , wherein when it is determined that the flow rate measured by the flow meter or the amount of water measured by the level gauge is insufficient, the bypass flow path is switched to the ejector drive flow path.

5. A chemical heat storage reactor having a chemical heat storage material using water as a reaction medium; A recovery vessel having an absorbent material for absorbing water vapor and recovering water vapor generated from the chemical heat storage material; A condenser that condenses the water vapor generated from the absorbent; An evaporator that supplies water vapor to be reacted with the chemical heat storage material to the chemical heat storage reactor, a water utilization path for supplying water condensed in the condenser to the evaporator; The water utilization route is An electric pump, An ejector, a pump suction passage for sucking one of the water in the evaporator and the water in the condenser into the electric pump; an ejector suction flow passage for sucking the other of the water in the evaporator and the water in the condenser into the ejector as a suction fluid of the ejector; an ejector driving flow passage that supplies water discharged from the electric pump to the ejector as a driving fluid for the ejector; an evaporator liquid delivery flow path that delivers the water discharged from the ejector to the evaporator.

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