Hydrogen storage supply system

Abstract

To provide a hydrogen storage supply system that can suppress an installation capacity of a cold / hot heat source even when a hydrogen occlusion speed and discharge speed to a hydrogen storage alloy are high.SOLUTION: A hydrogen storage supply system 1 includes: an alloy tank 10 in which a hydrogen storage alloy is encapsulated and through which a heat medium exchanging heat with the hydrogen storage alloy passes; a cold / hot heat source 20 for cooling and heating the heat medium; a heat storage tank 30 for storing the heat medium at a predetermined temperature; a first circulation path part through which the heat medium circulates between the cold / hot heat source 20 and the heat storage tank 30; and a second circulation path part through which the heat medium circulates among the alloy tank 10, the cold / hot heat source 20 and the heat storage tank 30.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a hydrogen storage and delivery system. [Background technology]

[0002] When hydrogen is used in a building or the like, it is necessary to store the hydrogen for a certain period of time. One possible method of storing hydrogen is to use a hydrogen storage alloy, which has the property of absorbing hydrogen. When hydrogen is absorbed into the hydrogen storage alloy, the hydrogen storage alloy must be cooled. On the other hand, when hydrogen is released from the hydrogen storage alloy, the hydrogen storage alloy must be heated. By sealing the hydrogen storage alloy inside an alloy tank and running a heat medium through the alloy tank to cool or heat the hydrogen storage alloy inside the alloy tank, it is possible to store or release hydrogen into the hydrogen storage alloy.

[0003] Patent document 1 discloses a hydrogen utilization system in which a heat transfer medium (cold water, hot water) is circulated between an alloy tank containing a hydrogen storage alloy and a heat storage tank, and the heat transfer medium from the heat storage tank is cooled with a cold heat source or heated with a fuel cell (hot heat source) before being supplied into the alloy tank to cool or heat the hydrogen storage alloy. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent No. 7201176 Summary of the Invention [Problem to be solved by the invention]

[0005] Incidentally, the output of the heat source (cold heat source, hot heat source) required to cool or heat the heat transfer medium is related to the rate at which hydrogen is absorbed and released from the hydrogen storage alloy. For example, in order to increase the rate at which hydrogen is absorbed into the hydrogen storage alloy, it is necessary to increase the output of the cold heat source required to cool the heat transfer medium. On the other hand, in order to increase the rate at which hydrogen is released from the hydrogen storage alloy, it is necessary to increase the output of the hot heat source required to heat the heat transfer medium. For this reason, when hydrogen is rapidly absorbed from the outside into the hydrogen storage alloy in the alloy tank, and when hydrogen is supplied to equipment that consumes a large amount of hydrogen per unit time, a heat source (cold heat source, hot heat source) with a large capacity is required. However, when the capacity of the heat source is large, the installation cost of the hydrogen storage and supply system that stores and supplies hydrogen becomes high, which is not preferable.

[0006] The present invention has been made in consideration of the above circumstances, and aims to provide a hydrogen storage and supply system that can keep the heat source equipment capacity small even if the hydrogen absorption and release rates in a hydrogen storage alloy are high. [Means for solving the problem]

[0007] One aspect of the present invention is a hydrogen storage and supply system that causes a hydrogen storage alloy to absorb hydrogen and release the hydrogen from the hydrogen storage alloy, the hydrogen storage and supply system comprising: an alloy tank in which the hydrogen storage alloy is sealed and through which a heat medium passes that exchanges heat with the hydrogen storage alloy; a cold / hot heat source that cools or heats the heat medium; a heat storage tank that stores the heat medium at a predetermined temperature; a first circulation path section through which the heat medium circulates between the cold / hot heat source and the heat storage tank; and a second circulation path section through which the heat medium circulates between the alloy tank and the cold / hot heat source and the heat storage tank. Effect of the Invention

[0008] According to the present invention, even if the hydrogen absorption and release rates for the hydrogen storage alloy are high, the installed capacity of the heat source (hot / cold heat source) provided in the hydrogen storage and supply system can be kept small. [Brief description of the drawings]

[0009] [Figure 1] 1 is a schematic block diagram showing a hydrogen storage and supply system according to a first embodiment of the present invention. [Diagram 2] FIG. 4 is a schematic block diagram showing a hydrogen storage and supply system according to a second embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] First Embodiment Hereinafter, a first embodiment of the present invention will be described with reference to FIG. The hydrogen storage and supply system 1 according to the first embodiment shown in Fig. 1 is a system that takes in hydrogen from the outside and stores it in a hydrogen storage alloy, and releases hydrogen from the hydrogen storage alloy and supplies it to the outside. The hydrogen storage and supply system 1 includes an alloy tank 10, a low / high temperature heat source 20, a heat storage tank 30, a first circulation path section, a second circulation path section, and a control device 40.

[0011] A hydrogen storage alloy is sealed in the alloy tank 10. Inside the alloy tank 10, hydrogen is appropriately absorbed and released from the hydrogen storage alloy. When hydrogen is absorbed into the hydrogen storage alloy, hydrogen is introduced into the alloy tank 10. When hydrogen is released from the hydrogen storage alloy, hydrogen is released to the outside of the alloy tank 10. The alloy tank 10 is configured to allow a heat transfer medium to pass through for heat exchange with the hydrogen storage alloy. The heat transfer medium may be a fluid, but in this embodiment, it is a liquid.

[0012] A hydrogen path section RH through which hydrogen flows in and out of the alloy tank 10 is connected to the alloy tank 10. A mass flow controller 50 that adjusts the flow rate of hydrogen flowing in and out of the alloy tank 10 is provided in the hydrogen path section RH.

[0013] The hot / cold heat source 20 cools or heats a heat medium. In this embodiment, the hot / cold heat source 20 is a chiller, but is not limited thereto. The heat storage tank 30 stores the heat medium so as to maintain the heat medium at a predetermined temperature.

[0014] The first circulation path portion is a path portion for the heat medium through which the heat medium circulates between the low / high temperature heat source 20 and the heat storage tank 30. The second circulation path portion is a path portion for the heat medium circulates between the alloy tank 10 and the low / high temperature heat source 20 and the heat storage tank 30. In the hydrogen storage and supply system 1 of this embodiment, the path portions through which the heat medium passes include an introduction path portion R11, a discharge path portion R12, a first branch path portion R13, and a second branch path portion R14.

[0015] The introduction path section R11 is a path section connected to the alloy tank 10 and through which the heat transfer medium passes to be introduced into the alloy tank 10. The introduction path section R11 is provided with a first valve V1 that opens and closes the introduction path section R11, and a first pump P1 that pumps the heat transfer medium passing through the introduction path section R11 toward the alloy tank 10. The discharge path section R12 is a path section connected to the alloy tank 10 and through which the heat transfer medium discharged from the alloy tank 10 passes. In this embodiment, an expansion tank 60 that absorbs thermal expansion of the heat transfer medium is provided in the middle of the discharge path section R12.

[0016] The first branch path section R13 and the second branch path section R14 are two path sections branching off and extending from the downstream end of the discharge path section R12. The downstream ends of the first branch path section R13 and the second branch path section R14 are connected to the upstream end of the introduction path section R11.

[0017] The above-mentioned low / high temperature heat source 20 is provided in the first branch path section R13. The first branch path section R13 is also provided with a second valve V2 for opening and closing the inlet path section R11 and a second pump P2 for pumping the heat medium passing through the first branch path section R13 toward the connection point of the inlet path section R11 and the second branch path section R14. In FIG. 1, the second valve V2 and the second pump P2 are provided in the first branch path section R13 between the low / high temperature heat source 20 and the connection point of the exhaust path section R12, the first branch path section R13, and the second branch path section R14. For example, at least one of the second valve V2 and the second pump P2 may be provided in the first branch path section R13 between the low / high temperature heat source 20 and the connection point of the inlet path section R11, the first branch path section R13, and the second branch path section R14.

[0018] The above-mentioned heat storage tank 30 is provided in the second branch path section R14. A third valve V3 for opening and closing the second branch path section R14 is provided in the second branch path section R14 between the heat storage tank 30 and the connection point of the introduction path section R11, the first branch path section R13, and the second branch path section R14. A fourth valve V4 for opening and closing the second branch path section R14 is provided in the second branch path section R14 between the heat storage tank 30 and the connection point of the discharge path section R12, the first branch path section R13, and the second branch path section R14.

[0019] The first circulation path portion is composed of a first branch path portion R13 and a second branch path portion R14. The second circulation path portion is composed of an introduction path portion R11, a discharge path portion R12, the first branch path portion R13, and the second branch path portion R14.

[0020] The hydrogen storage and supply system 1 further includes a first temperature measurement unit T1, a second temperature measurement unit T2, a third temperature measurement unit T3, and a pressure measurement unit P. The first temperature measurement unit T1 is provided in the alloy tank 10 and measures the temperature of the alloy tank 10. The second temperature measurement unit T2 is provided in the introduction path unit R11 and measures the temperature of the heat medium immediately before being introduced into the alloy tank 10. In this embodiment, the second temperature measurement unit T2 is provided in the introduction path unit R11 between the first valve V1 and the alloy tank 10. The third temperature measurement unit T3 is provided in the heat storage tank 30 and measures the temperature of the heat storage tank 30. The pressure measurement unit P is provided in the alloy tank 10 and measures the pressure inside the alloy tank 10.

[0021] The control device 40 controls the operation of the hydrogen storage and supply system 1. This control is performed appropriately mainly depending on whether hydrogen is stored in or released from the hydrogen storage alloy in the alloy tank 10. The control device 40 mainly controls the opening and closing of the valves V1 to V4 and the ON / OFF of the pumps P1 and P2 to switch the path through which the heat medium flows. The control device 40 also controls the operation of the low-temperature heat source 20.

[0022] When there is no absorption or release of hydrogen into or from the hydrogen storage alloy, the control device 40 causes the heat medium to flow through the first circulation path portion, i.e., causes the heat medium to circulate between the low / high temperature heat source 20 and the heat storage tank 30. In practice, the control device 40 closes the first valve V1 and opens the second to fourth valves V2 to V4. The control device 40 also turns off the first pump P1 and turns on the second pump P2. This causes the heat medium to circulate between the low / high temperature heat source 20 and the heat storage tank 30.

[0023] When the heat medium flows through the first circulation path portion, the control device 40 controls the operation of the low / high temperature heat source 20 to cause the low / high temperature heat source 20 to heat or cool the heat medium. For example, when it is predicted that the state will be switched from one in which the hydrogen storage alloy does not absorb or release hydrogen to one in which hydrogen is absorbed by the hydrogen storage alloy, the control device 40 causes the low / high heat source 20 to cool the heat medium. This allows the heat medium to be stored in the heat storage tank 30 at a low temperature. On the other hand, when it is predicted that the state will be switched from one in which the hydrogen storage alloy does not absorb or release hydrogen to one in which hydrogen is released from the hydrogen storage alloy, the control device 40 causes the low / high heat source 20 to heat the heat medium. This allows the heat medium to be stored in the heat storage tank 30 at a high temperature. The prediction of hydrogen absorption or release from the hydrogen storage alloy can be performed based on a hydrogen absorption and release plan prepared in advance. For example, when the hydrogen storage and supply system 1 is used in a building, the hydrogen absorption and release plan can be prepared in a BEMS (Building Energy Management System) or the like.

[0024] When hydrogen is absorbed or released from the hydrogen storage alloy, the control device 40 causes the heat medium to flow through the second circulation path portion, i.e., causes the heat medium to circulate between the alloy tank 10 and the low / high temperature heat source 20 and the heat storage tank 30, and supplies the heat medium from the heat storage tank 30 or the low / high temperature heat source 20 to the alloy tank 10. In practice, the control device 40 opens the first valve V1 and appropriately controls the second to fourth valves V2 to V4 and the first and second pumps P1 and P2. The patterns for supplying the heat medium from the heat storage tank 30 or the low / high temperature heat source 20 to the alloy tank 10 include a first supply pattern, a second supply pattern, and a third supply pattern.

[0025] The first supply pattern is a pattern in which the heat medium is supplied only from the heat storage tank 30 to the alloy tank 10. In the first supply pattern, the control device 40 opens the first, third and fourth valves V1, V3 and V4 and closes the second valve V2. The control device 40 also turns on the first pump P1 and turns off the second pump P2. This causes the heat medium to be supplied only from the heat storage tank 30 to the alloy tank 10. The heat medium discharged from the alloy tank 10 returns only to the heat storage tank 30. In the first supply pattern, the control device 40 stops the operation of the low / high temperature heat source 20.

[0026] In the first supply pattern, the heat medium stored in the heat storage tank 30 at a predetermined temperature is supplied to the alloy tank 10. Therefore, when hydrogen is absorbed in the hydrogen storage alloy when the heat medium is supplied from the heat storage tank 30 to the alloy tank 10, the control device 40 stores the low-temperature heat medium cooled in advance by the low-temperature heat source 20 in the heat storage tank 30 before the heat medium is supplied to the alloy tank 10. This allows the hydrogen storage alloy to be cooled by the heat medium supplied from the low-temperature heat source 20 to the alloy tank 10 during hydrogen absorption. On the other hand, when hydrogen is released from the hydrogen storage alloy when the heat medium is supplied from the heat storage tank 30 to the alloy tank 10, the control device 40 stores the high-temperature heat medium heated in advance by the low-temperature heat source 20 in the heat storage tank 30 before the heat medium is supplied to the alloy tank 10. This allows the hydrogen storage alloy to be heated by the heat medium supplied from the low-temperature heat source 20 to the alloy tank 10 during hydrogen release.

[0027] The second supply pattern is a pattern in which the heat medium is supplied to the alloy tank 10 from both the low / high temperature heat source 20 and the heat storage tank 30. In the second supply pattern, the control device 40 opens the first to fourth valves V1 to V4. The control device 40 also turns on the first and second pumps P1 and P2. This causes the heat medium to be supplied to the alloy tank 10 from both the low / high temperature heat source 20 and the heat storage tank 30. The heat medium discharged from the alloy tank 10 returns to both the low / high temperature heat source 20 and the heat storage tank 30.

[0028] In the second supply pattern, the control device 40 causes the low / high temperature heat source 20 to cool or heat the heat medium. For example, when hydrogen is absorbed into the hydrogen storage alloy, the control device 40 causes the low / high temperature heat source 20 to cool the heat medium. This allows the hydrogen storage alloy to be cooled by the heat medium supplied from the low / high temperature heat source 20 to the alloy tank 10 during hydrogen absorption. On the other hand, when hydrogen is released from the hydrogen storage alloy, the control device 40 causes the low / high temperature heat source 20 to heat the heat medium. This allows the hydrogen storage alloy to be heated by the heat medium supplied from the low / high temperature heat source 20 to the alloy tank 10 during hydrogen release. In the second supply pattern, similarly to the first supply pattern, a heat transfer medium of a predetermined temperature that has been stored in the heat storage tank 30 in advance in anticipation of hydrogen absorption or release is supplied from the heat storage tank 30 to the alloy tank 10.

[0029] The third supply pattern is a pattern in which the heat medium is supplied to the alloy tank 10 only from the low / high temperature heat source 20. In the third supply pattern, the control device 40 opens the first and second valves V1 and V2 and closes the third and fourth valves V3 and V4. The control device 40 also turns off the first pump P1 and turns on the second pump P2. This causes the heat medium to be supplied to the alloy tank 10 only from the low / high temperature heat source 20. The heat medium discharged from the alloy tank 10 returns only to the low / high temperature heat source 20. In the third supply pattern, the control device 40 causes the heat medium to be cooled or heated by the low / high temperature heat source 20 in the same manner as in the second supply pattern. In the above-described third supply pattern, the control device 40 may, for example, turn on the first pump P1 and turn off the second pump P2, or may, for example, turn on both the first and second pumps P1 and P2.

[0030] Table 1 briefly shows the pattern (heat storage pattern) in which the heat medium circulates between the low / high temperature heat source 20 and the heat storage tank 30, and the opening / closing control of the valves V1 to V4 and the operation control of the pumps P1 and P2 in the first to third supply patterns in which the heat medium is supplied to the alloy tank 10.

[0031] [Table 1]

[0032] In Table 1, "storing cold / hot heat in the heat storage tank 30" corresponds to the heat storage pattern. "supplying cold / hot heat only from the heat storage tank 30 to the alloy tank 10" corresponds to the first supply pattern. "supplying cold / hot heat to the alloy tank 10 by using the heat storage tank 30 and the cold / hot heat source 20 in combination" corresponds to the second supply pattern. "supplying cold / hot heat only from the cold / hot heat source 20 to the alloy tank 10" corresponds to the third supply pattern.

[0033] In this embodiment, when hydrogen is absorbed or released from the hydrogen storage alloy, the control device 40 selects one of the first supply pattern, the second supply pattern, and the third supply pattern described above, depending on at least one of the temperature of the alloy tank 10, the temperature of the heat medium immediately before being introduced into the alloy tank 10, the temperature of the heat storage tank 30, and the pressure inside the alloy tank 10. Here, the "temperature of the alloy tank 10" is a measurement value measured by the first temperature measurement unit T1 described above. The "temperature of the heat medium immediately before being introduced into the alloy tank 10" is a measurement value measured by the second temperature measurement unit T2 described above. The "temperature of the heat storage tank 30" is a measurement value measured by the third temperature measurement unit T3. The "pressure inside the alloy tank 10" is a measurement value measured by the pressure measurement unit P.

[0034] The selection of supply patterns by the controller 40 in response to various temperatures and pressures is further described below. The control device 40 switches from the first supply pattern to the second supply pattern, or from the second supply pattern to the third supply pattern, when at least one of the temperature of the alloy tank 10, the temperature of the heat medium just before the alloy tank 10, and the temperature of the heat storage tank 30 exceeds a predetermined temperature threshold, or when the pressure inside the alloy tank 10 exceeds a predetermined pressure threshold, during the storage of hydrogen in the hydrogen storage alloy. For example, when at least one of the temperatures of the alloy tank 10, the heat medium immediately before the alloy tank 10, and the heat storage tank 30 exceeds a first temperature threshold value during hydrogen absorption, or when the pressure in the alloy tank 10 exceeds a first pressure threshold value, the control device 40 switches from the first supply pattern to the second supply pattern. Furthermore, when at least one of the temperatures of the alloy tank 10, the heat medium immediately before the alloy tank 10, and the heat storage tank 30 exceeds a second temperature threshold value that is higher than the first temperature threshold value, or when the pressure in the alloy tank 10 exceeds a second pressure threshold value that is higher than the first pressure threshold value, the control device 40 switches from the second supply pattern to the third supply pattern.

[0035] The temperature threshold during hydrogen absorption may be, for example, 80° C. or less, which can suppress the influence on the heat resistance of the pumps P1, P2, etc. For example, the first temperature threshold may be 10° C. or more and 80° C. or less, and the second temperature threshold may be 15° C. or more and 80° C. or less. The pressure threshold during hydrogen absorption may be, for example, equal to or lower than the set pressure of a safety valve attached to the alloy tank 10. For example, the first pressure threshold may be 0.10 MPaG or more and 0.95 MPaG or less, and the second pressure threshold may be 0.15 MPaG or more and 0.95 MPaG or less. The temperature threshold and pressure threshold during hydrogen absorption are not limited to the above numerical ranges, and may be set appropriately depending on the equipment capacity, operation, and the like.

[0036] During hydrogen absorption, the control device 40 switches the supply pattern as described above. Therefore, even if the cooling of the hydrogen storage alloy by the heat medium from the heat storage tank 30 is insufficient in the first and second supply patterns due to an increase in the temperature of the low-temperature heat medium previously stored in the heat storage tank 30, the hydrogen storage alloy can be cooled by the heat medium cooled by the low / high temperature heat source 20 by switching to the second and third supply patterns. Therefore, the hydrogen storage alloy can be continuously cooled during hydrogen absorption.

[0037] When releasing hydrogen to the hydrogen storage alloy, the control device 40 switches from the first supply pattern to the second supply pattern, or from the second supply pattern to the third supply pattern, when at least one of the temperature of the alloy tank 10, the temperature of the heat medium just before the alloy tank 10, and the temperature of the heat storage tank 30 falls below a predetermined temperature threshold, or when the pressure inside the alloy tank 10 falls below a predetermined pressure threshold. For example, when at least one of the temperatures of the alloy tank 10, the heat medium immediately before the alloy tank 10, and the heat storage tank 30 falls below a third temperature threshold during hydrogen release, or when the pressure in the alloy tank 10 falls below a third pressure threshold, the control device 40 switches from the first supply pattern to the second supply pattern. Furthermore, when at least one of the temperatures of the alloy tank 10, the heat medium immediately before the alloy tank 10, and the heat storage tank 30 falls below a fourth temperature threshold lower than the third temperature threshold, or when the pressure in the alloy tank 10 falls below a fourth pressure threshold lower than the third pressure threshold, the control device 40 switches from the second supply pattern to the third supply pattern.

[0038] The temperature threshold value when releasing hydrogen may be, for example, a temperature at which the heat medium can be prevented from freezing (0°C or higher when the heat medium is water). For example, the third temperature threshold value may be 0°C or higher and 80°C or lower, and the fourth temperature threshold value may be 0°C or higher and 75°C or lower. The pressure threshold for releasing hydrogen may be, for example, equal to or higher than the pressure (for example, 0.1 MPaG) at which hydrogen can be released from the alloy tank 10. For example, the first pressure threshold may be equal to or higher than 0.10 MPaG and equal to or lower than 0.95 MPaG, and the second pressure threshold may be equal to or higher than 0.1 MPaG and equal to or lower than 0.90 MPaG. The temperature threshold and pressure threshold during hydrogen release are not limited to the above numerical ranges, and may be set appropriately depending on the equipment capacity, operation, etc.

[0039] When hydrogen is released, the control device 40 switches the supply pattern as described above. Therefore, even if the heating of the hydrogen storage alloy by the heat medium from the heat storage tank 30 is insufficient in the first and second supply patterns due to an increase in the temperature of the high-temperature heat medium previously stored in the heat storage tank 30, the hydrogen storage alloy can be heated by the heat medium heated by the low / high temperature heat source 20 by switching to the second and third supply patterns. Therefore, the hydrogen storage alloy can be continuously heated when hydrogen is released.

[0040] Furthermore, when hydrogen is absorbed or released from the hydrogen storage alloy, the control device 40 of this embodiment selects one of the above-mentioned first supply pattern, second supply pattern, or third supply pattern according to the hydrogen absorption flow rate (absorption rate) or hydrogen release flow rate (release rate) from the hydrogen storage alloy. Information on the "hydrogen absorption flow rate" and the "hydrogen release flow rate" can be obtained, for example, from the above-mentioned mass flow controller 50.

[0041] The selection of the supply pattern by the control device 40 in accordance with the flow rates of hydrogen absorption and release will be further described below. When hydrogen is absorbed or released from the hydrogen storage alloy, if the hydrogen absorption flow rate or release flow rate is equal to or less than a predetermined flow rate threshold, the control device 40 supplies the heat medium to the alloy tank 10 in the first supply pattern or the third supply pattern to cool or warm the hydrogen storage alloy. If the hydrogen absorption flow rate or release flow rate exceeds the predetermined flow rate threshold, the control device 40 switches from the first or third supply pattern to the second supply pattern. As a result, the heat medium is supplied from both the low / high temperature heat source 20 and the heat storage tank 30, and the energy for cooling or heating the hydrogen storage alloy can be increased. As a result, even if the hydrogen absorption flow rate or release flow rate becomes larger than expected, hydrogen can be absorbed or released sufficiently. The flow rate threshold value may be a predicted value or a planned value of the hydrogen absorption flow rate or release flow rate by, for example, a BEMS or the like.

[0042] As described above, in the hydrogen storage and supply system 1 of this embodiment, when there is no absorption or release of hydrogen into or from the hydrogen storage alloy, the heat medium can be flowed through the first circulation path portion, thereby storing the heat medium in advance at a desired temperature in the heat storage tank 30. This makes it possible to keep the equipment capacity of the low / high heat source 20 provided in the hydrogen storage and supply system 1 small, even if the hydrogen absorption and release rates into and from the hydrogen storage alloy are high.

[0043] For example, when hydrogen is to be absorbed in a hydrogen storage alloy, a heat medium may be passed through the first circulation path portion in advance, and the heat medium cooled in the low / high temperature heat source 20 may be stored in the heat storage tank 30. In this way, the low-temperature heat medium stored in the heat storage tank 30 may be used to cool the hydrogen storage alloy, thereby increasing the rate at which hydrogen is absorbed into the hydrogen storage alloy. Similarly, when there is a plan to release hydrogen from the hydrogen storage alloy, a heat medium can be caused to flow in advance through the first circulation path portion, and the heat medium heated in the low / high temperature heat source 20 can be stored in the heat storage tank 30. In this way, the high temperature heat medium stored in the heat storage tank 30 can be used to heat the hydrogen storage alloy, thereby increasing the rate at which hydrogen is released from the hydrogen storage alloy.

[0044] In the hydrogen storage and supply system 1 of this embodiment, when hydrogen is absorbed or released from the hydrogen storage alloy, the control device 40 selects one of the first supply pattern, the second supply pattern, and the third supply pattern according to at least one of the temperature of the alloy tank 10, the temperature of the heat medium immediately before being introduced into the alloy tank 10, the temperature of the heat storage tank 30, and the pressure inside the alloy tank 10. This makes it possible to supply a heat medium of an appropriate temperature to the alloy tank 10 when hydrogen is absorbed or released from the hydrogen storage alloy, thereby sufficiently cooling or heating the hydrogen storage alloy. Therefore, even if the equipment capacity of the cooling / heating heat source 20 is kept small, hydrogen can be sufficiently absorbed or released.

[0045] Second Embodiment Next, a second embodiment of the present invention will be described with reference to Fig. 2. In the following description, configurations common to those already described will be given the same reference numerals and duplicated description will be omitted.

[0046] As shown in FIG. 2, the hydrogen storage and supply system 1A according to the second embodiment includes an alloy tank 10, a low / high temperature heat source 20, a heat storage tank 30, a first circulation path section, a second circulation path section, a control device 40, and the like, similar to those of the first embodiment. The hydrogen storage and supply system 1A of the second embodiment differs from the first embodiment mainly in the specific path sections constituting the first and second circulation path sections. In the hydrogen storage and supply system 1A of the second embodiment, the path sections through which the heat transfer medium passes include a first connection path section R21, a second connection path section R22, a third connection path section R23, a first bypass path section R31, a second bypass path section R32, and a third bypass path section R33.

[0047] The first connection path portion R21 connects the alloy tank 10 and the low / high temperature heat source 20. In this embodiment, the first connection path portion R21 functions as an introduction path portion through which a heat medium passes to be introduced into the alloy tank 10. The first connection path portion R21 is provided with a fifth valve V5 that opens and closes the first connection path portion R21.

[0048] The second connection path portion R22 connects the alloy tank 10 and the heat storage tank 30. In this embodiment, the second connection path portion R22 functions as a discharge path portion through which the heat medium discharged from the alloy tank 10 passes. The second connection path portion R22 is provided with a seventh valve V7 that opens and closes the second connection path portion R22. The heat storage tank 30 connected to the second connection path portion R22 also functions as an expansion tank.

[0049] The third connection path section R23 connects the heat storage tank 30 and the low-temperature heat source 20. The third connection path section R23 is provided with a ninth valve V9 that opens and closes the third connection path section R23, and a pump P3 that pressure-feeds the heat medium passing through the third connection path section R23 toward the low-temperature heat source 20. In Fig. 2, the pump P3 and the ninth valve V9 are sequentially arranged in a direction from the heat storage tank 30 toward the low-temperature heat source 20.

[0050] The first bypass path portion R31 branches off from the first connection path portion R21 and is connected to the second connection path portion R22. Specifically, the first bypass path portion R31 branches off from a portion of the first connection path portion R21 between the low / high heat source 20 and the fifth valve V5. The first bypass path portion R31 is connected to a portion of the second connection path portion R22 between the alloy tank 10 and the seventh valve V7. The first bypass path portion R31 is provided with a sixth valve V6 that opens and closes the first bypass path portion R31.

[0051] The second bypass path portion R32 branches off from a portion of the second connection path portion R22 between the connection point with the first bypass path portion R31 and the heat storage tank 30, and is connected to the third connection path portion R23. Specifically, the second bypass path portion R32 branches off from a portion of the second connection path portion R22 between the connection point with the first bypass path portion R31 and the seventh valve V7. The second bypass path portion R32 is provided with an eighth valve V8 that opens and closes the second bypass path portion R32.

[0052] The third bypass path section R33 branches off from a portion of the third connection path section R23 between the connection point with the second bypass path section R32 and the low / high temperature heat source 20, and is connected to a portion of the first connection path section R21 between the low / high temperature heat source 20 and the branch point with the first bypass path section R31. Specifically, the third bypass path section R33 branches off from a portion of the third connection path section R23 between the pump P3 and the ninth valve V9. The third bypass path section R33 is provided with a tenth valve V10 that opens and closes the third bypass path section R33.

[0053] In the hydrogen storage and supply system 1A of the second embodiment, the first circulation path section is composed of the first bypass path section R31, a portion of the second connection path section R22 between the connection point with the first bypass path section R31 and the heat storage tank 30, the third connection path section R23, and a portion of the first connection path section R21 between the low-temperature heat source 20 and the branch point with the first bypass path section R31. The second circulation path section is composed of the first connection path section R21, the second connection path section R22, the third connection path section R23, the second bypass path section R32, and the third bypass path section R33.

[0054] The hydrogen storage and supply system 1A of the second embodiment includes a first temperature measurement unit T1, a second temperature measurement unit T2, a third temperature measurement unit T3, and a pressure measurement unit P similar to those of the first embodiment. In the second embodiment, the second temperature measurement unit T2 is provided between the fifth valve V5 and the alloy tank 10 in the first connection path unit R21.

[0055] In the second embodiment, when there is no absorption or release of hydrogen into or from the hydrogen storage alloy, the control device 40 closes the fifth, eighth, and tenth valves V5, V8, and V10 and opens the sixth, seventh, and ninth valves V6, V7, and V9 to allow the heat medium to flow through the first circulation path portion. The control device 40 also turns on the pump P3. This causes the heat medium to circulate between the low / high temperature heat source 20 and the heat storage tank 30. When the heat medium flows through the first circulation path portion, the control device 40 controls the operation of the low / high temperature heat source 20 in the same manner as in the first embodiment, and causes the low / high temperature heat source 20 to heat or cool the heat medium.

[0056] When hydrogen is absorbed or released from the hydrogen storage alloy, the controller 40 opens the fifth valve V5, closes the sixth valve V6, and turns on the pump P3 in order to allow the heat medium to flow through the second circulation path portion. Furthermore, the controller 40 appropriately controls the seventh to tenth valves V7 to V10. The patterns for supplying the heat medium from the heat storage tank 30 or the low / high temperature heat source 20 to the alloy tank 10 include the first supply pattern, the second supply pattern, and the third supply pattern, which are the same as those in the first embodiment.

[0057] In the first supply pattern, the control device 40 opens the fifth, seventh, and tenth valves V5, V7, and V10, and closes the sixth, eighth, and ninth valves V6, V8, and V9. This causes the heat medium to be supplied only from the heat storage tank 30 to the alloy tank 10. The heat medium discharged from the alloy tank 10 returns only to the heat storage tank 30. In the first supply pattern, the control device 40 stops the operation of the low-temperature heat source 20.

[0058] In the second supply pattern, the control device 40 opens the fifth, seventh, and ninth valves V5, V7, and V9, and closes the sixth, eighth, and tenth valves V6, V8, and V10. This allows the heat medium to be supplied from both the low-temperature heat source 20 and the heat storage tank 30 to the alloy tank 10. The heat medium discharged from the alloy tank 10 returns to both the low-temperature heat source 20 and the heat storage tank 30. In the second supply pattern of the second embodiment, the heat medium discharged from the alloy tank 10 passes through the heat storage tank 30 and the low-temperature heat source 20 in order, and then returns to the alloy tank 10. In the second supply pattern, the control device 40 causes the low-temperature heat source 20 to cool or heat the heat medium.

[0059] In the third supply pattern, the control device 40 opens the fifth, eighth, and ninth valves V5, V8, and V9, and closes the sixth, seventh, and tenth valves V6, V7, and V10. This causes the heat medium to be supplied to the alloy tank 10 only from the low / high temperature heat source 20. The heat medium discharged from the alloy tank 10 returns only to the low / high temperature heat source 20. In the third supply pattern, the control device 40 causes the heat medium to be cooled or heated by the low / high temperature heat source 20 in the same manner as in the second supply pattern.

[0060] Table 2 briefly shows the pattern (heat storage pattern) in which the heat medium circulates between the low / high temperature heat source 20 and the heat storage tank 30, and the opening / closing control of the valves V5 to V10 and the operation control of the pump P3 in the first to third supply patterns in which the heat medium is supplied to the alloy tank 10.

[0061] [Table 2]

[0062] Furthermore, in the second embodiment, as in the first embodiment, when hydrogen is absorbed or released from the hydrogen storage alloy, the control device 40 selects one of the first supply pattern, second supply pattern, or third supply pattern described above depending on at least one of the temperature of the alloy tank 10, the temperature of the heat transfer medium immediately before being introduced into the alloy tank 10, the temperature of the heat storage tank 30, and the pressure within the alloy tank 10, and depending on the hydrogen absorption flow rate (absorption rate) or hydrogen release flow rate (release rate) from the hydrogen storage alloy.

[0063] The hydrogen storage and supply system 1A of the second embodiment has the same effects as the first embodiment. Moreover, the hydrogen storage and supply system 1A of the second embodiment includes a first connection path section R21, a second connection path section R22, a third connection path section R23, a first bypass path section R31, a second bypass path section R32, and a third bypass path section R33. With this, it is possible to circulate the heat medium between the heat storage tank 30 and the low / high temperature heat source 20, or to circulate the heat medium between the alloy tank 10 and the heat storage tank 30 and the low / high temperature heat source 20, by using a single pump P3. Therefore, it is possible to provide a hydrogen storage and supply system 1A with lower installation costs.

[0064] In the second embodiment, the pump P3 may pump the heat medium passing through the third connection path portion R23 toward the heat storage tank 30 side, for example.

[0065] In the second embodiment, the pump P3 is not limited to being disposed at a position between the connection point of the third connection path section R23 with the second bypass path section R32 and the connection point of the third bypass path section R33. The pump P3 may be disposed, for example, at a position between the connection point of the first connection path section R21 with the third bypass path section R33 and the connection point of the first bypass path section R31. The pump P3 may also be disposed, for example, at a position between the connection point of the second connection path section R22 with the first bypass path section R31 and the connection point of the second bypass path section R32.

[0066] Although the embodiment of the present invention has been described above, the present invention is not limited to the above embodiment, and can be modified as appropriate without departing from the spirit of the present invention.

[0067] In the hydrogen storage and supply system of the present invention, during hydrogen absorption or release, the control device 40 may monitor, for example, only one of the temperature of the alloy tank 10, the temperature of the heat medium just before the alloy tank 10, the temperature of the heat storage tank 30, and the pressure within the alloy tank 10, and select one of the first to third supply patterns based on the monitored measured values. [Explanation of symbols]

[0068] 1,1A Hydrogen storage and supply system 10 Alloy Tank 20. Hot and cold sources 30 Heat storage tank 40 Control device 50 Mass Flow Controller 60 Expansion Tank P Pressure measurement section R11 Introduction Path R12 Exhaust path section R13 First branch path R14 Second branch path section R21 First connection path R22 Second connection path R23 Third connection path R31 First bypass route R32 Second bypass route R33 Third bypass route RH Hydrogen path T1 First temperature measurement section T2 Second temperature measuring section T3 Third temperature measuring section

Claims

1. A hydrogen storage and supply system for causing a hydrogen storage alloy to absorb hydrogen and for causing the hydrogen storage alloy to release the hydrogen, comprising: an alloy tank in which the hydrogen storage alloy is sealed and through which a heat medium passes for heat exchange with the hydrogen storage alloy; A cold / hot heat source for cooling or heating the heat transfer medium; a heat storage tank for storing the heat medium at a predetermined temperature; A first circulation path portion in which the heat medium circulates between the low-temperature heat source and the heat storage tank; a second circulation path portion through which the heat medium circulates between the alloy tank and the low / high temperature heat source and the heat storage tank.

2. The hydrogen storage and supply system of claim 1, further comprising a control device which causes the heat transfer medium to flow through the first circulation path section when there is no absorption or release of hydrogen into the hydrogen storage alloy, and causes the heat transfer medium to flow through the second circulation path section when there is absorption or release of hydrogen into the hydrogen storage alloy.

3. The hydrogen storage and supply system of claim 2, wherein the control device, when hydrogen is absorbed or released from the hydrogen storage alloy, selects one of the following supply patterns: a first supply pattern in which the heat medium is supplied to the alloy tank only from the heat storage tank, a second supply pattern in which the heat medium is supplied to the alloy tank from both the low-temperature heat source and the heat storage tank, and a third supply pattern in which the heat medium is supplied to the alloy tank only from the low-temperature heat source, depending on at least one of the temperature of the alloy tank, the temperature of the heat medium immediately before being introduced into the alloy tank, the temperature of the heat storage tank, and the pressure within the alloy tank.

4. The hydrogen storage and supply system of claim 3, wherein the control device switches from the first supply pattern to the second supply pattern, or from the second supply pattern to the third supply pattern, when at least one of the temperatures exceeds a predetermined temperature threshold or when the pressure exceeds a predetermined pressure threshold during storage of the hydrogen into the hydrogen storage alloy.

5. The hydrogen storage and supply system of claim 3, wherein the control device switches from the first supply pattern to the second supply pattern, or switches from the second supply pattern to the third supply pattern, when at least one of the temperatures falls below a predetermined temperature threshold or when the pressure falls below a predetermined pressure threshold during release of the hydrogen from the hydrogen storage alloy.

6. The hydrogen storage and supply system of claim 2, wherein the control device selects, depending on the hydrogen absorption flow rate or the hydrogen release flow rate for the hydrogen storage alloy, one of a first supply pattern in which the heat transfer medium is supplied to the alloy tank only from the heat storage tank, a second supply pattern in which the heat transfer medium is supplied to the alloy tank from both the low-temperature heat source and the heat storage tank, and a third supply pattern in which the heat transfer medium is supplied to the alloy tank only from the low-temperature heat source.

7. A first connection path portion connecting the alloy tank and the hot / cold heat source; A second connection path portion that connects the alloy tank and the heat storage tank; A third connection path portion that connects the heat storage tank and the low-temperature heat source; a first bypass path portion branching from the first connection path portion and connected to the second connection path portion; a second bypass path portion that branches off from a portion of the second connection path portion between a connection point with the first bypass path portion and the heat storage tank and is connected to the third connection path portion; a third bypass path portion that branches off from a portion of the third connection path portion between a connection point with the second bypass path portion and the low / high temperature heat source and is connected to a portion of the first connection path portion between a branch point with the low / high temperature heat source and the first bypass path portion, the first circulation path portion is composed of the first bypass path portion, a portion of the second connection path portion between a connection point with the first bypass path portion and the heat storage tank, the third connection path portion, and a portion of the first connection path portion between the low-temperature heat source and a branch point with the first bypass path portion, 7. The hydrogen storage and supply system according to claim 1, wherein the second circulation path portion is composed of the first connection path portion, the second connection path portion, the third connection path portion, the second bypass path portion, and the third bypass path portion.

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