gas supply system

Abstract

To provide a technology capable of using ammonia adsorbed to an adsorbent.SOLUTION: A gas supply system can execute a first desorption step of desorbing ammonia adsorbed to an adsorbent in a first vessel. The first desorption step includes, in a state in which ammonia is adsorbed to the adsorbent in the first vessel, heating gas in the first vessel by a first heater, suctioning the gas in the first vessel into a raw material gas passage through a first suction passage and an ejector by supplying the raw material gas to a reformer through the raw material gas passage, and supplying the suctioned gas together with the raw material gas to the reformer through the raw material gas passage.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The technology disclosed in this specification relates to a gas supply system.

Background Art

[0002] A gas supply system is disclosed in Patent Document 1. The gas supply system of Patent Document 1 includes a reformer that generates reformed gas by reforming raw material gas, and a raw material gas passage that supplies the raw material gas to the reformer. Further, the gas supply system of Patent Document 1 includes an adsorber having an adsorbent that adsorbs ammonia contained in the reformed gas generated by the reformer.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the gas supply system of Patent Document 1, ammonia adsorbed by the adsorbent cannot be utilized. Therefore, this specification provides a technology that can utilize ammonia adsorbed by the adsorbent.

Means for Solving the Problems

[0005] The gas supply system disclosed herein includes a reformer that generates a reformed gas by reforming a raw material gas, a raw material gas passage for supplying the raw material gas to the reformer, an ejector provided in the raw material gas passage, a first adsorbent comprising a first container containing an adsorbent for adsorbing ammonia contained in the gas, a first suction passage connected to the first container and the ejector, and a first heater for heating the gas in the first container. The gas supply system is capable of performing a first desorption step for desorbing ammonia adsorbed on the adsorbent in the first container. In the first desorption step, with ammonia adsorbed on the adsorbent in the first container, the gas in the first container is heated by the first heater, and the raw material gas is supplied to the reformer through the raw material gas passage, thereby drawing the gas in the first container into the raw material gas passage through the first suction passage and the ejector, and supplying the drawn gas together with the raw material gas to the reformer through the raw material gas passage.

[0006] With this configuration, the gas in the first container is heated by the first heater while the gas in the first container is drawn into the first suction passage by the ejector, thereby desorbing the ammonia adsorbed on the adsorbent in the first container and supplying it to the reformer. Therefore, the ammonia adsorbed on the adsorbent can be utilized.

[0007] The gas supply system may further include a fuel cell that generates electricity using fuel gas derived from the reformed gas produced by the reformer.

[0008] This configuration allows fuel gas derived from reformed gas using ammonia adsorbed on an adsorbent to be supplied to the fuel cell. This enables the supply of a large amount of fuel gas to the fuel cell, thereby accelerating power generation by the fuel cell.

[0009] The gas supply system is connected to the reformer and the first container and may further include a first reformed gas passage for supplying reformed gas produced by the reformer to the first container, a first on-off valve for opening and closing the first reformed gas passage, and a second on-off valve for opening and closing the first suction passage. The gas supply system may be capable of performing a first adsorption step in which ammonia contained in the reformed gas produced by the reformer is adsorbed onto an adsorbent in the first container. In the first adsorption step, with the first on-off valve open and the second on-off valve closed, raw material gas may be supplied to the reformer through the raw material gas passage, and reformed gas produced by the reformer may be supplied into the first container through the first reformed gas passage. When the first adsorption step is performed after the first desorption step, the second on-off valve may be closed with the first on-off valve closed, and then the first on-off valve may be opened with the second on-off valve closed before performing the first adsorption step.

[0010] With this configuration, when switching from the first desorption step to the first adsorption step, it is possible to suppress the suction of the reformed gas supplied into the first container through the first reformed gas passage to the ejector through the first suction passage.

[0011] The gas supply system may further include a second adsorbent comprising a second container containing an adsorbent for adsorbing ammonia contained in the gas, and a second reformed gas passage connected to the reformer and the second container, for supplying the reformed gas produced by the reformer to the second container. The gas supply system may also be capable of performing a second adsorption step in which ammonia contained in the reformed gas produced by the reformer is adsorbed onto the adsorbent in the second container. In the second adsorption step, by supplying the raw material gas to the reformer through the raw material gas passage, the gas drawn into the raw material gas passage in the first desorption step is supplied to the reformer together with the raw material gas through the raw material gas passage, and the reformed gas produced by the reformer is supplied into the second container through the second reformed gas passage.

[0012] With this configuration, the second adsorption step can be performed simultaneously with the first desorption step. By supplying reformed gas into the second container, ammonia adsorbed on the adsorbent in the first container can be desorbed.

[0013] The gas supply system may further include a connecting passage that is connected to the first container and the second container, and supplies the gas from which ammonia has been adsorbed by the adsorbent in the second container in the second adsorption step into the first container.

[0014] With this configuration, the gas supplied from the second container to the first container can desorb the ammonia adsorbed on the adsorbent in the first container. This reduces the time required for desorption in the first adsorbent.

[0015] The gas supply system is provided in the connecting passage and may further include a control valve for adjusting the flow rate of gas supplied from the second container to the first container.

[0016] This configuration allows for adjustment of the rate of ammonia desorption in the first adsorbent. For example, increasing the opening of the control valve can increase the rate of ammonia desorption, while decreasing the opening of the control valve can decrease the rate of ammonia desorption.

[0017] The gas supply system may further include a first pressure detection unit for detecting the pressure in the first container, a second pressure detection unit for detecting the pressure in the second container, and a control unit. The control unit may control the opening degree of the regulating valve based on the difference between the pressure detected by the second pressure detection unit and the pressure detected by the first pressure detection unit.

[0018] This configuration allows for maintaining a good gas state in both the first and second containers. [Brief explanation of the drawing]

[0019] [Figure 1]A diagram schematically showing the gas supply system of the embodiment. [Figure 2] A cross-sectional view of the ejector of the embodiment. [Figure 3] A diagram schematically showing the first state of the gas supply system of the embodiment. [Figure 4] A diagram schematically showing the second state of the gas supply system of the embodiment. [Figure 5] A diagram schematically showing the third state of the gas supply system of the embodiment. [Figure 6] A diagram schematically showing the fourth state of the gas supply system of the embodiment. [Figure 7] A diagram showing the control of the opening degree of the regulating valve of the embodiment. [Figure 8] A diagram schematically showing the gas supply system of the modified example.

Mode for Carrying Out the Invention

[0020] The gas supply system 2 of the embodiment will be described with reference to the drawings. As shown in FIG. 1, the gas supply system 2 of the embodiment includes a raw material tank 10, an ejector 70, a reformer 12, a first adsorber 14, a second adsorber 16, a fuel cell 18, and a control device 100 (an example of a control unit).

[0021]

[0022] The raw material tank 10 stores a raw material gas (for example, ammonia gas, hydrocarbon gas (city gas such as methane gas), formic acid gas, hydrazine gas, methylcyclohexane gas, etc.). A raw material gas passage 60 through which the raw material gas flows is connected to the raw material tank 10. The upstream end of the raw material gas passage 60 is connected to the raw material tank 10, and the downstream end is connected to the reformer 12. The raw material gas passage 60 supplies the raw material gas from the raw material tank 10 to the reformer 12. The raw material gas in the raw material tank 10 is pumped to the reformer 12 through the raw material gas passage 60 by the pressure in the raw material tank 10. In a modified example, a pump for pumping the raw material gas may be provided in the raw material gas passage 60.An ejector 70 is provided in the raw material gas passage 60. The raw material gas passage 60 comprises a first raw material gas passage 601 located upstream of the ejector 70 and a second raw material gas passage 602 located downstream of the ejector 70.

[0023] The ejector 70 is connected to the downstream end of the common suction passage 64, which will be described later. The upstream end of the common suction passage 64 is connected to the first container 142 of the first adsorber 14 and the second container 162 of the second adsorber 16, which will be described later. The ejector 70 is configured to draw gas from the common suction passage 64 by the negative pressure generated by the flow of raw material gas in the raw material gas passage 60. The ejector 70 can draw gas from the first container 142 or gas from the second container 162 into the raw material gas passage 60 through the common suction passage 64. The gas drawn in by the ejector 70 is supplied to the reformer 12 through the raw material gas passage 60 together with the raw material gas.

[0024] Figure 2 is a cross-sectional view of the ejector 70 of the embodiment. As shown in Figure 2, the ejector 70 includes a raw material gas inlet 80, a suction port 82, a throttling section 84, and a raw material gas outlet 86. The downstream end of the first raw material gas passage 601 is connected to the raw material gas inlet 80. Raw material gas is introduced into the ejector 70 from the first raw material gas passage 601 through the raw material gas inlet 80. The downstream end of the common suction passage 64 is connected to the suction port 82. Gas is drawn into the ejector 70 from the common suction passage 64 through the suction port 82. The upstream end of the second raw material gas passage 602 is connected to the raw material gas outlet 86. Raw material gas is discharged from the ejector 70 through the raw material gas outlet 86 to the second raw material gas passage 602.

[0025] The throttling section 84 of the ejector 70 is located between the raw material gas inlet 80 and the raw material gas outlet 86. The passage area of ​​the throttling section 84 is narrower than the passage areas on the upstream and downstream sides of the throttling section 84. The throttling section 84 is the part that increases the flow velocity of the raw material gas passing through the ejector 70.

[0026] The ejector 70 is configured to reduce the pressure in the common suction passage 64 connected to the ejector 70 by the flow of the raw material gas passing through the throttling section 84. The raw material gas that has passed through the throttling section 84 is discharged from the raw material gas outlet 86 into the second raw material gas passage 602, together with the gas drawn in from the suction port 82. In this way, the ejector 70 is a device that can draw in a fluid (gas) by creating a reduced pressure state through the Venturi effect. The principle of the ejector 70 is well known, so further detailed explanation will be omitted.

[0027] As shown in Figure 1, the second raw material gas passage 602 is connected to the reformer 12. The reformer 12 produces reformed gas by reforming the raw material gas (e.g., ammonia gas) supplied by the raw material gas passage 60 (first raw material gas passage 601 and second raw material gas passage 602). The catalyst used for reforming the raw material gas in the reformer 12 is, for example, copper, nickel, or ruthenium. The reformed gas produced by the reformer 12 contains hydrogen. This reformed gas also contains ammonia, a by-product of reforming, and undecomposed ammonia.

[0028] The upstream end of the common reformed gas passage 62 through which the reformed gas flows is connected to the reformer 12. Downstream of the common reformed gas passage 62, it branches into a first reformed gas passage 621 and a second reformed gas passage 622. The downstream end of the first reformed gas passage 621 is connected to the first container 142 of the first adsorber 14. The downstream end of the second reformed gas passage 622 is connected to the second container 162 of the second adsorber 16. The common reformed gas passage 62 and the first reformed gas passage 621 supply the reformed gas produced in the reformer 12 into the first container 142 of the first adsorber 14. The common reformed gas passage 62 and the second reformed gas passage 622 supply the reformed gas produced in the reformer 12 into the second container 162 of the second adsorber 16.

[0029] A first on-off valve 31 is provided in the first reformed gas passage 621. The first on-off valve 31 opens and closes the first reformed gas passage 621. When the first on-off valve 31 is open, reformed gas can be supplied to the first adsorber 14 through the first reformed gas passage 621. When the first on-off valve 31 is closed, reformed gas is no longer supplied from the reformer 12 to the first adsorber 14.

[0030] A third on-off valve 33 is provided in the second reformed gas passage 622 (the second on-off valve 32 will be described later). The third on-off valve 33 opens and closes the second reformed gas passage 622. When the third on-off valve 33 is open, reformed gas can be supplied to the second adsorber 16 through the second reformed gas passage 622. When the third on-off valve 33 is closed, reformed gas is no longer supplied from the reformer 12 to the second adsorber 16.

[0031] The first adsorbent 14 will now be described. The first adsorbent 14 comprises a first container 142 and an adsorbent F contained within the first container 142. The adsorbent F is, for example, activated carbon, zeolite, MOF (Metal Organic Framework), etc. The adsorbent F is filled into the first container 142. The adsorbent F adsorbs ammonia contained in the reformed gas introduced into the first container 142 from the first reformed gas passage 621. The first adsorbent 14 generates fuel gas by adsorbing ammonia contained in the reformed gas with the adsorbent F.

[0032] The gas supply system 2 further includes a first heater 72 for heating the gas in the first container 142 of the first adsorber 14. The first heater 72 is, for example, positioned around the first adsorber 14. In a modified example, the first heater 72 may be positioned inside the first container 142 of the first adsorber 14. The first heater 72 is, for example, electrically or gas-powered. For example, the first heater 72 may be an electric heater that generates heat when an electric current is applied. Alternatively, the first heater 72 may be a gas burner that heats an object using the heat of combustion of gas. Or, the first heater 72 may be a heat exchanger. In the gas supply system 2, when the gas in the first container 142 is heated by the first heater 72, the gas expands and its volume increases. For example, the volume of the gas in the first container 142 increases by approximately 160 times due to the heating.

[0033] The first container 142 of the first adsorbent 14 is equipped with a first pressure sensor 50 (an example of a first pressure detection unit). The first pressure sensor 50 detects the pressure inside the first container 142. The pressure information detected by the first pressure sensor 50 is transmitted to the control device 100.

[0034] Furthermore, the upstream end of the first suction passage 641 is connected to the first container 142 of the first adsorber 14. The downstream side of the first suction passage 641 merges with the second suction passage 642, which will be described later, to form a common suction passage 64. The downstream end of the common suction passage 64 is connected to an ejector 70 provided in the raw material gas passage 60. When raw material gas flows through the raw material gas passage 60, the ejector 70 causes the gas in the first container 142 to be drawn into the raw material gas passage 60 through the first suction passage 641 and the common suction passage 64.

[0035] A second on-off valve 32 is provided in the first suction passage 641. The second on-off valve 32 opens and closes the first suction passage 641. When the second on-off valve 32 is open, the gas in the first container 142 can flow through the first suction passage 641, and when the second on-off valve 32 is closed, the gas in the first container 142 cannot flow through the first suction passage 641.

[0036] In addition to the first suction passage 641, the first container 142 of the first adsorber 14 is connected to the upstream end of the first fuel gas passage 661 through which the fuel gas flows. The downstream side of the first fuel gas passage 661 merges with the second fuel gas passage 662, which will be described later, to form a common fuel gas passage 66. The downstream end of the common fuel gas passage 66 is connected to the fuel cell 18. The first fuel gas passage 661 and the common fuel gas passage 66 supply the fuel gas generated in the first adsorber 14 to the fuel cell 18.

[0037] A fifth on-off valve 40 is provided in the first fuel gas passage 661. The fifth on-off valve 40 opens and closes the first fuel gas passage 661. When the fifth on-off valve 40 is open, fuel gas can be supplied to the fuel cell 18 through the first fuel gas passage 661. When the fifth on-off valve 40 is closed, fuel gas is no longer supplied from the first adsorber 14 to the fuel cell 18.

[0038] Next, the second adsorbent 16 will be described. The second adsorbent 16 comprises a second container 162 and an adsorbent F contained within the second container 162. The adsorbent F is, for example, activated carbon, zeolite, MOF (Metal Organic Framework), etc. The adsorbent F is filled into the second container 162. The adsorbent F adsorbs ammonia contained in the reformed gas introduced into the second container 162 from the second reformed gas passage 622. The second adsorbent 16 generates fuel gas by adsorbing ammonia contained in the reformed gas with the adsorbent F.

[0039] The gas supply system 2 further includes a second heater 74 for heating the gas in the second container 162 of the second adsorber 16. The second heater 74 is, for example, positioned around the second adsorber 16. In a modified example, the second heater 74 may be positioned inside the second container 162 of the second adsorber 16. The second heater 74 is, for example, electrically or gas-powered. For example, the second heater 74 may be an electric heater that generates heat when an electric current is applied. Alternatively, the second heater 74 may be a gas burner that heats an object using the heat of combustion of the gas. Or, the second heater 74 may be a heat exchanger. In the gas supply system 2, when the gas in the second container 162 is heated by the second heater 74, the gas expands and its volume increases. For example, the volume of the gas in the second container 162 increases by approximately 160 times due to the heating.

[0040] The second container 162 of the second adsorber 16 is equipped with a second pressure sensor 52 (an example of a second pressure detection unit). The second pressure sensor 52 detects the pressure inside the second container 162. The pressure information detected by the second pressure sensor 52 is transmitted to the control device 100.

[0041] Furthermore, the upstream end of the second suction passage 642 is connected to the second container 162 of the second adsorber 16. The downstream side of the second suction passage 642 merges with the first suction passage 641 to form a common suction passage 64. The downstream end of the common suction passage 64 is connected to an ejector 70 provided in the raw material gas passage 60. When raw material gas flows through the raw material gas passage 60, the ejector 70 causes the gas in the second container 162 to be drawn into the raw material gas passage 60 through the second suction passage 642 and the common suction passage 64.

[0042] A fourth on-off valve 34 is provided in the second suction passage 642. The fourth on-off valve 34 opens and closes the second suction passage 642. When the fourth on-off valve 34 is open, the gas in the second container 162 can flow through the second suction passage 642, and when the fourth on-off valve 34 is closed, the gas in the second container 162 cannot flow through the second suction passage 642.

[0043] In addition to the second suction passage 642, the second container 162 of the second adsorber 16 is connected to the upstream end of the second fuel gas passage 662 through which fuel gas flows. The downstream side of the second fuel gas passage 662 merges with the first fuel gas passage 661 to form a common fuel gas passage 66. The downstream end of the common fuel gas passage 66 is connected to the fuel cell 18. The second fuel gas passage 662 and the common fuel gas passage 66 supply the fuel gas generated in the second adsorber 16 to the fuel cell 18.

[0044] A sixth on-off valve 42 is provided in the second fuel gas passage 662. The sixth on-off valve 42 opens and closes the second fuel gas passage 662. When the sixth on-off valve 42 is open, fuel gas can be supplied to the fuel cell 18 through the second fuel gas passage 662. When the sixth on-off valve 42 is closed, fuel gas is no longer supplied from the second adsorber 16 to the fuel cell 18.

[0045] The gas supply system 2 further includes a connecting passage 20 connected to the first fuel gas passage 661 and the second fuel gas passage 662, and a control valve 44 provided in the connecting passage 20. One end of the connecting passage 20 is connected to the first fuel gas passage 661 upstream of the fifth on-off valve 40 (on the first adsorber 14 side). The connecting passage 20 is connected to the first container 142 of the first adsorber 14 via the first fuel gas passage 661. The other end of the connecting passage 20 is connected to the second fuel gas passage 662 upstream of the sixth on-off valve 42 (on the second adsorber 16 side). The connecting passage 20 is connected to the second container 162 of the second adsorber 16 via the second fuel gas passage 662. The control valve 44 is configured to adjust the flow rate of gas flowing through the connecting passage 20 by adjusting its opening degree.

[0046] Next, the fuel cell 18 will be described. In addition to the common fuel gas passage 66, the fuel cell 18 is connected to an air passage 69 through which air flows. The upstream end of the air passage 69 is connected to an air supply source (not shown), and the downstream end is connected to the fuel cell 18. Air is supplied to the fuel cell 18 from the air supply source through the air passage 69. The upstream end of the air passage 69 may be open to the outside air.

[0047] The fuel cell 18 generates electricity using fuel gas supplied through a common fuel gas passage 66 and air supplied through an air passage 69. The fuel cell 18 includes, for example, multiple battery cells (not shown) stacked inside a container, and each battery cell generates electricity through a chemical reaction between hydrogen contained in the fuel gas and oxygen contained in the air. The battery cells are, for example, solid oxide fuel cells (SOFCs) or polymer electrolyte fuel cells (PEFCs), but are not limited to these. In a fuel cell 18 that generates electricity using fuel gas, unreacted fuel gas is discharged as exhaust gas during power generation.

[0048] An exhaust gas passage 68 is connected to the fuel cell 18 through which exhaust gas flows. The upstream end of the exhaust gas passage 68 is connected to the fuel cell 18, and the downstream end is connected to a discharge point (not shown). Exhaust gas is discharged from the fuel cell 18 to the discharge point through the exhaust gas passage 68. The discharge point may be, for example, a reformer 12, a first adsorbent 14, a second adsorbent 16, etc.

[0049] The control device 100 includes, for example, a CPU and memory (neither of which are shown), and performs various controls and processes related to the gas supply system 2 according to the program stored in the memory.

[0050] Next, we will explain the operation of the gas supply system 2. For convenience, we will describe the first state shown in Figure 3 as the initial state.

[0051] (First state; Figure 3) In the first state of the gas supply system 2, as shown in Figure 3, the first on-off valve 31 is closed, the second on-off valve 32 is open, the third on-off valve 33 is open, and the fourth on-off valve 34 is closed. Also, the fifth on-off valve 40 is closed, and the sixth on-off valve 42 is open. The opening degree of the control valve 44 is controllable. Furthermore, in the first state, the first heater 72 is operating, and the second heater 74 is stopped. Also, in the first state, ammonia is adsorbed on the adsorbent F of the first adsorbent 14.

[0052] In the first state, the first desorption process is performed in the first adsorbent 14. Specifically, in the first state, the first heater 72 heats the gas in the first container 142 of the first adsorbent 14, causing the gas in the first container 142 to expand. When raw material gas is supplied to the reformer 12 through the raw material gas passage 60 in this state, the gas that has expanded in the first container 142 is drawn into the raw material gas passage 60 through the first suction passage 641 and the common suction passage 64 by the action of the ejector 70 provided in the raw material gas passage 60. At this time, ammonia adsorbed on the adsorbent F of the first adsorbent 14 is desorbed into the gas in the first container 142. As a result, the gas containing the ammonia desorbed from the adsorbent F is drawn into the raw material gas passage 60. The gas containing the ammonia desorbed from the adsorbent F is supplied to the reformer 12 together with the raw material gas through the raw material gas passage 60.

[0053] Furthermore, in the first state, a second adsorption process is performed in the second adsorbent 16. Specifically, in the first state, when raw material gas is supplied to the reformer 12 through the raw material gas passage 60, the raw material gas is reformed in the reformer 12 to produce reformed gas. The reformed gas produced in the reformer 12 is supplied to the second adsorbent 16 through the common reformed gas passage 62 and the second reformed gas passage 622. The reformed gas produced by the reformer 12 contains ammonia. The ammonia contained in the reformed gas is adsorbed by the adsorbent F in the second adsorbent 16.

[0054] In the second adsorbent 16, fuel gas is generated when ammonia contained in the reformed gas is adsorbed by the adsorbent F. The fuel gas in this embodiment is the gas remaining after ammonia has been removed from the reformed gas. The fuel gas generated in the second adsorbent 16 is supplied to the fuel cell 18 through the second fuel gas passage 662 and the common fuel gas passage 66. The fuel cell 18 generates electricity using the fuel gas supplied through the common fuel gas passage 66. A portion of the fuel gas flowing through the second fuel gas passage 662 is supplied to the first container 142 of the first adsorbent 14 through the connecting passage 20 and the first fuel gas passage 661.

[0055] (Second state; Figure 4) Next, the second state will be described. As shown in Figure 4, in the second state, the first on-off valve 31 is closed, the second on-off valve 32 is closed, the third on-off valve 33 is open, and the fourth on-off valve 34 is closed. Also, the fifth on-off valve 40 is closed, and the sixth on-off valve 42 is open. The opening degree of the control valve 44 is controllable. Furthermore, in the second state, the first heater 72 is stopped, and the second heater 74 is stopped.

[0056] In the gas supply system 2, the control device 100 closes the second on-off valve 32 and turns off the first heater 72, thereby transitioning from the first state to the second state. In the second state, the first heater 72 stops, which cools the gas in the first container 142 of the first adsorber 14. Also in the second state, the second adsorption process is performed in the second adsorber 16. The second adsorption process in the second adsorber 16 is as described above.

[0057] (Third state; Figure 5) Next, the third state will be described. As shown in Figure 5, in the third state, the first on-off valve 31 is open, the second on-off valve 32 is closed, the third on-off valve 33 is open, and the fourth on-off valve 34 is closed. In addition, the fifth on-off valve 40 and the sixth on-off valve 42 are open. The opening degree of the control valve 44 is controllable. Furthermore, in the third state, the first heater 72 and the second heater 74 are stopped. In the gas supply system 2, the control device 100 opens the first on-off valve 31 and the fifth on-off valve 40, thereby transitioning from the second state to the third state.

[0058] In the third state, the first adsorption process is performed in the first adsorbent 14, and the second adsorption process is performed in the second adsorbent 16. Specifically, in the third state, when raw material gas is supplied to the reformer 12 through the raw material gas passage 60, the raw material gas is reformed in the reformer 12 to produce reformed gas. The reformed gas produced in the reformer 12 is supplied to the first adsorbent 14 through the common reformed gas passage 62 and the first reformed gas passage 621. The reformed gas produced by the reformer 12 contains ammonia. The ammonia contained in the reformed gas is adsorbed by the adsorbent F in the first adsorbent 14.

[0059] In the first adsorbent 14, fuel gas is generated when ammonia contained in the reformed gas is adsorbed onto the adsorbent F. The fuel gas in this embodiment is the gas remaining after ammonia has been removed from the reformed gas. The fuel gas generated in the first adsorbent 14 is supplied to the fuel cell 18 through the first fuel gas passage 661 and the common fuel gas passage 66. The fuel cell 18 generates electricity using the fuel gas supplied through the common fuel gas passage 66. The second adsorption process in the second adsorbent 16 is as described above.

[0060] In the third state, reformed gas is supplied to the first adsorber 14 and the second adsorber 16. In addition, the fuel gas generated in the first adsorber 14 and the second adsorber 16 is supplied to the fuel cell 18. As a result, in the third state, the pressure in the first container 142 of the first adsorber 14 and the pressure in the second container 162 of the second adsorber 16 become approximately the same.

[0061] (Fourth state; Figure 6) Next, the fourth state will be described. As shown in Figure 6, in the fourth state, the first on-off valve 31 is open, the second on-off valve 32 is closed, the third on-off valve 33 is closed, and the fourth on-off valve 34 is open. Also, the fifth on-off valve 40 is open, and the sixth on-off valve 42 is closed. The opening degree of the control valve 44 is controllable. Furthermore, in the fourth state, the first heater 72 is stopped, and the second heater 74 is operating. In the gas supply system 2, the control device 100 closes the third on-off valve 33, closes the sixth on-off valve 42, and starts the second heater 74, thereby transitioning from the third state to the fourth state.

[0062] In the fourth state, the first adsorption process is performed in the first adsorber 14. The first adsorption process in the first adsorber 14 is as described above. In the fourth state, a portion of the fuel gas flowing through the first fuel gas passage 661 is supplied into the second container 162 of the second adsorber 16 through the connecting passage 20 and the second fuel gas passage 662.

[0063] Furthermore, in the fourth state, a second desorption process is performed in the second adsorbent 16. Specifically, in the fourth state, the second heater 74 heats the gas in the second container 162 of the second adsorbent 16, causing the gas in the second container 162 to expand. When raw material gas is supplied to the reformer 12 through the raw material gas passage 60 in this state, the gas that has expanded in the second container 162 is drawn into the raw material gas passage 60 through the second suction passage 642 and the common suction passage 64 by the action of the ejector 70 provided in the raw material gas passage 60. At this time, ammonia adsorbed on the adsorbent F of the second adsorbent 16 is desorbed into the gas in the second container 162. As a result, the gas containing the ammonia desorbed from the adsorbent F is drawn into the raw material gas passage 60. The gas containing the ammonia desorbed from the adsorbent F is supplied to the reformer 12 together with the raw material gas through the raw material gas passage 60.

[0064] (From the 4th state to the 1st state) When transitioning the state of the gas supply system 2 from the fourth state to the first state, the control device 100 executes the reverse control described above. That is, when transitioning from the fourth state to the first state, the control device 100 executes the control described for the third on-off valve 33, fourth on-off valve 34, sixth on-off valve 42, and second heater 74 related to the second adsorber 16, respectively, for the first on-off valve 31, second on-off valve 32, fifth on-off valve 40, and first heater 72 related to the first adsorber 14. Conversely, when transitioning from the fourth state to the first state, the control device 100 executes the control described for the first on-off valve 31, second on-off valve 32, fifth on-off valve 40, and first heater 72 related to the first adsorber 14, respectively, for the third on-off valve 33, fourth on-off valve 34, sixth on-off valve 42, and second heater 74 related to the second adsorber 16.

[0065] (effect) The gas supply system 2 of the embodiment has been described above. As is clear from the above description, the gas supply system 2 includes an ejector 70 provided in the raw material gas passage 60, a first suction passage 641 connected to the first container 142 of the first adsorbent 14 and the ejector 70, and a first heater 72 for heating the gas in the first container 142. The gas supply system 2 is capable of performing a first desorption step to desorb ammonia adsorbed on the adsorbent F in the first container 142. In the first desorption step, with ammonia adsorbed on the adsorbent F in the first container 142, the gas in the first container 142 is heated by the first heater 72, and raw material gas is supplied to the reformer 12 through the raw material gas passage 60. As a result, the gas in the first container 142 is drawn into the raw material gas passage 60 by the action of the ejector 70, and the drawn gas is supplied to the reformer 12 together with the raw material gas.

[0066] With this configuration, the gas in the first container 142 is heated by the first heater 72 while the gas in the first container 142 is drawn into the raw material gas passage 60 by the ejector 70, thereby desorbing the ammonia adsorbed on the adsorbent F in the first container 142 and supplying it to the reformer 12. Therefore, the ammonia adsorbed on the adsorbent F can be utilized.

[0067] Furthermore, the gas supply system 2 includes a fuel cell 18 that generates electricity using fuel gas derived from the reformed gas produced by the reformer 12. With this configuration, fuel gas derived from the reformed gas, which utilizes ammonia adsorbed on the adsorbent F, can be supplied to the fuel cell 18. This allows a large amount of fuel gas to be supplied to the fuel cell 18, thereby accelerating the power generation of the fuel cell 18.

[0068] Furthermore, the gas supply system 2 includes a first reformed gas passage 621 that supplies reformed gas produced by the reformer 12 to the first container 142, a first on-off valve 31 that opens and closes the first reformed gas passage 621, and a second on-off valve 32 that opens and closes the first suction passage 641. The gas supply system 2 is capable of performing a first adsorption step in which ammonia contained in the reformed gas produced by the reformer 12 is adsorbed onto the adsorbent F in the first container 142. In the first adsorption step, with the first on-off valve 31 open and the second on-off valve 32 closed, raw material gas is supplied to the reformer 12 through the raw material gas passage 60. This supplies the reformed gas produced by the reformer 12 into the first container 142 through the first reformed gas passage 621. In the gas supply system 2, when the first adsorption step is performed after the first desorption step, the second on-off valve 32 is closed while the first on-off valve 31 is closed, and then the first on-off valve 31 is opened while the second on-off valve 32 is closed before the adsorption step is performed (see Figures 3-5). With this configuration, when switching from the first desorption step to the first adsorption step, it is possible to suppress the suction of the reformed gas supplied into the first container 142 through the first reformed gas passage 621 to the ejector 70 through the first suction passage 641. In other words, it is possible to prevent backflow of the reformed gas.

[0069] Furthermore, the gas supply system 2 includes a first adsorbent 14 and a second adsorbent 16. The gas supply system 2 is capable of performing a second adsorption step in which ammonia contained in the reformed gas produced by the reformer 12 is adsorbed onto the adsorbent F of the second adsorbent 16. In the second adsorption step, by supplying raw material gas to the reformer 12 through the raw material gas passage 60, the gas drawn into the raw material gas passage 60 in the first desorption step of the first adsorbent 14 is supplied to the reformer 12 together with the raw material gas. In addition, the reformed gas produced by the reformer 12 is supplied into the second container 162 through the second reformed gas passage 622. With this configuration, the first desorption step and the second adsorption step can be performed simultaneously. By supplying reformed gas into the second container 162, ammonia adsorbed on the adsorbent F in the first container 142 can be desorbed. Furthermore, even when the first adsorbent 14 is in the first desorption step, fuel gas can be supplied to the fuel cell 18 via the second adsorbent 16. Therefore, fuel gas can be continuously supplied to the fuel cell 18.

[0070] Furthermore, the gas supply system 2 is equipped with a connecting passage 20 that supplies the gas remaining after ammonia has been adsorbed onto the adsorbent F in the second container 162 into the first container 142. With this configuration, the gas supplied from the second container 162 to the first container 142 can desorb the ammonia adsorbed onto the adsorbent F in the first container 142. This shortens the time required for desorption in the first adsorbent 14.

[0071] Furthermore, the gas supply system 2 is equipped with a control valve 44 located in the connecting passage 20. The control valve 44 adjusts the flow rate of gas supplied from the second container 162 to the first container 142. With this configuration, the rate of ammonia desorption in the first adsorbent 14 can be adjusted. For example, by increasing the opening of the control valve 44, the rate of ammonia desorption can be increased, and by decreasing the opening of the control valve 44, the rate of ammonia desorption can be decreased.

[0072] (Correspondence) The combination of the first suction passage 641 and the common suction passage 64 is an example of a "first suction passage". The combination of the common reformed gas passage 62 and the first reformed gas passage 621 is an example of a "first reformed gas passage". The combination of the common reformed gas passage 62 and the second reformed gas passage 622 is an example of a "second reformed gas passage".

[0073] (modified version) (1) In some embodiments, in a first state of the gas supply system 2 (see Figure 3), the control device 100 may control the opening degree of the regulating valve 44 based on the difference (P2-P1) between the pressure P2 detected by the second pressure sensor 52 and the pressure P1 detected by the first pressure sensor 50. The control device 100 may also control the opening degree of the regulating valve 44 based on the relationship between the pressure difference (P2-P1) and a predetermined reference value Pt.

[0074] Figure 7 shows the control of the opening degree of the regulating valve 44 in the embodiment. The control device 100 may perform the control of Case 1 and the control of Case 2 shown in Figure 7. In Case 1, if the pressure difference (P2-P1) is greater than or equal to the reference value Pt, the control device 100 increases the opening degree of the regulating valve 44 (i.e., moves the regulating valve 44 to the open side). Also, if the pressure difference (P2-P1) is less than the reference value Pt, the control device 100 decreases the opening degree of the regulating valve 44 (i.e., moves the regulating valve 44 to the closed side).

[0075] In Case 2, the control device 100 reduces the opening of the control valve 44 (i.e., moves the control valve 44 to the closed side) if the pressure difference (P2-P1) is greater than or equal to the reference value Pt. The control device 100 increases the opening of the control valve 44 (i.e., moves the control valve 44 to the open side) if the pressure difference (P2-P1) is less than the reference value Pt.

[0076] According to the above configuration, by controlling the opening degree of the control valve 44 based on the pressure difference (P2-P1), the gas state in the first container 142 and the second container 162 can be maintained in a good state. For example, in Case 1, by increasing the opening degree of the control valve 44, it is possible to suppress the pressure in the second container 162 during the second adsorption process from becoming too high. Also, by decreasing the opening degree of the control valve 44, it is possible to suppress the pressure in the second container 162 during the second adsorption process from approaching the pressure in the first container 142 during the first desorption process.

[0077] Furthermore, according to Case 2, by reducing the opening of the control valve 44, it is possible to suppress excessive gas flow from the second container 162 to the first container 142. Conversely, by increasing the opening of the control valve 44, it is possible to suppress insufficient gas flow from the second container 162 to the first container 142.

[0078] (2) In some embodiments, the connecting passage 20 and the control valve 44 may be omitted, as shown in Figure 8. In this configuration, the control device 100 may control the opening degree of the fifth on-off valve 40 and the sixth on-off valve 42.

[0079] In the configuration shown in Figure 8, when the first desorption process and the second adsorption process are being performed simultaneously (first state; see Figure 3), the fifth on-off valve 40 opens, and a portion of the fuel gas flowing through the second fuel gas passage 662 is supplied to the first container 142 of the first adsorber 14 through the first fuel gas passage 661.

[0080] In the first state (see Figure 3), the control device 100 controls the opening degree of the fifth on-off valve 40 to prevent too much fuel gas from flowing into the first container 142 through the first fuel gas passage 661, thereby preventing the amount of fuel gas supplied to the fuel cell 18 from becoming too small.

[0081] Furthermore, in the configuration shown in Figure 8, when the first adsorption process and the second desorption process are being performed simultaneously (fourth state; see Figure 6), the sixth on-off valve 42 opens, and a portion of the fuel gas flowing through the first fuel gas passage 661 is supplied to the second container 162 of the second adsorber 16 through the second fuel gas passage 662.

[0082] In the fourth state (see Figure 6), the control device 100 controls the opening degree of the sixth on-off valve 42 to prevent too much fuel gas from flowing into the second container 162 through the second fuel gas passage 662, thereby preventing the amount of fuel gas supplied to the fuel cell 18 from becoming too small.

[0083] Furthermore, in the configuration shown in Figure 8, the control device 100 may control the opening degree of the fifth on-off valve 40 in the second state (see Figure 4) to prevent the pressure inside the first container 142 from becoming too high.

[0084] (Correspondence) In the configuration shown in Figure 8, the combination of the first fuel gas passage 661 and the first fuel gas passage 661 is an example of a "connecting passage".

[0085] (3) Each valve 31, 32, 33, 34, 40, 42, 44 may be opened and closed automatically or manually. The configuration for opening and closing each valve 31, 32, 33, 34, 40, 42, 44 is not particularly limited.

[0086] (4) The common reformed gas passage 62 may be separated into a first reformed gas passage 621 and a second reformed gas passage 622. The common suction passage 64 may be separated into a first suction passage 641 and a second suction passage 642. The common fuel gas passage 66 may be separated into a first fuel gas passage 661 and a second fuel gas passage 662.

[0087] (5) The distinction between "first" and "second" in the above explanation is for convenience only and they are interchangeable.

[0088] Although specific examples of the present invention have been described in detail above, these are merely illustrative and do not limit the scope of the claims. The technologies described in the claims include various modifications and changes to the specific examples illustrated above. The technical elements described in this specification or drawings exhibit technical usefulness individually or in various combinations, and are not limited to the combinations described in the claims at the time of filing. Furthermore, the technologies illustrated in this specification or drawings can achieve multiple objectives simultaneously, and achieving even one of these objectives itself constitutes technical usefulness. [Explanation of symbols]

[0089] 2: Gas supply system, 10: Raw material tank, 12: Reformer, 14: First adsorber, 16: Second adsorber, 18: Fuel cell, 20: Connecting passage, 31: First shut-off valve, 32: Second shut-off valve, 33: Third shut-off valve, 34: Fourth shut-off valve, 40: Fifth shut-off valve, 42: Sixth shut-off valve, 44: Control valve, 50: First pressure sensor, 52: Second pressure sensor, 60: Raw material gas passage, 62: Common reformed gas passage, 64: Common suction passage, 66: Common fuel gas passage, 68: Exhaust gas passage, 6 9: Air passage, 70: Ejector, 72: First heater, 74: Second heater, 80: Raw material gas inlet, 82: Suction port, 84: Throttle section, 86: Raw material gas outlet, 100: Control device, 142: First container, 162: Second container, 601: First raw material gas passage, 602: Second raw material gas passage, 621: First reformed gas passage, 622: Second reformed gas passage, 641: First suction passage, 642: Second suction passage, 661: First fuel gas passage, 662: Second fuel gas passage, F: Adsorbent

Claims

1. A reformer that generates reformed gas by reforming the raw material gas, A raw material gas passage for supplying raw material gas to the reformer, An ejector provided in the aforementioned raw material gas passage, A first adsorbent comprising a first container containing an adsorbent for adsorbing ammonia contained in the gas, The first container and the first suction passage connected to the ejector, A first heater for heating the gas in the first container, A second adsorbent comprising a second container containing an adsorbent for adsorbing ammonia contained in the gas, The reformer and the second container are connected, and the reformed gas passage is provided for supplying the reformed gas generated by the reformer to the second container. A first desorption step of desorbing ammonia adsorbed on the adsorbent in the first container, A second adsorption step is possible, in which ammonia contained in the reformed gas produced by the reformer is adsorbed onto the adsorbent in the second container. A connecting passage is provided, which is connected to the first container and the second container, and supplies the gas remaining after ammonia has been adsorbed by the adsorbent in the second container in the second adsorption step into the first container. A control valve is provided in the aforementioned connecting passage for adjusting the flow rate of gas supplied from the second container to the first container, A first pressure detection unit for detecting the pressure inside the first container, A second pressure detection unit for detecting the pressure inside the second container, The control unit further comprises, In the first desorption step, with ammonia adsorbed on the adsorbent in the first container, the gas in the first container is heated by the first heater, and the raw material gas is supplied to the reformer through the raw material gas passage, thereby drawing the gas in the first container into the raw material gas passage through the first suction passage and the ejector, and the drawn gas is supplied to the reformer through the raw material gas passage together with the raw material gas. In the second adsorption step, by supplying the raw material gas to the reformer through the raw material gas passage, the gas drawn into the raw material gas passage in the first desorption step is supplied to the reformer together with the raw material gas through the raw material gas passage, and the reformed gas produced by the reformer is supplied to the second container through the second reformed gas passage. The control unit controls the opening degree of the adjustment valve based on the difference between the pressure detected by the second pressure detection unit and the pressure detected by the first pressure detection unit, in a gas supply system.

2. A gas supply system according to claim 1, A gas supply system further comprising a fuel cell that generates electricity using fuel gas derived from the reformed gas produced by the reformer.

3. A gas supply system according to claim 1 or 2, A first reformed gas passage is connected to the reformer and the first container, and supplies the reformed gas generated by the reformer to the first container. A first on / off valve for opening and closing the first reformed gas passage, The system further comprises a second on-off valve for opening and closing the first suction passage, A first adsorption step can be performed in which ammonia contained in the reformed gas produced by the reformer is adsorbed onto the adsorbent in the first container. In the first adsorption step, with the first on-off valve open and the second on-off valve closed, raw material gas is supplied to the reformer through the raw material gas passage, and the reformed gas produced by the reformer is supplied into the first container through the first reformed gas passage. A gas supply system in which, when the first adsorption step is performed after the first desorption step, the second on-off valve is closed while the first on-off valve is closed, and then the first on-off valve is opened while the second on-off valve is closed before performing the first adsorption step.

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