Power generation system

Abstract

To provide a power generating system that can sufficiently improve power generation efficiency without requiring complicated control.SOLUTION: A power generating system 1 includes a fuel cell 10 in which a plurality of flat plate-shaped laminated materials including at least a separator 11 through which air passes, a separator 12 through which hydrogen gas G passes, and an MEA 13 disposed between the separators 11, 12 are stacked and integrated together, and configured to generate electricity by reacting air with hydrogen gas G via the MEA 13. The power generating system 1 includes a humidifier 4 having a water tank 21 through which hydrogen gas G to be supplied to the separator 12 can pass, and humidifying the hydrogen gas G that is passed through the water tank 21. The humidifier 4 includes a "first heat exchange section" that heats water W in the water tank 21 by heat exchange with air discharged from the separator 11.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a power generation system configured to be capable of generating power through a reaction between a first gas containing an oxidant and a second gas containing hydrogen.

Background Art

[0002] When generating power with a fuel cell, it is necessary to supply hydrogen gas or the like with sufficient humidity to the fuel cell in order to avoid reductions in power generation efficiency and damage to the membrane electrode assembly caused by excessive drying of the membrane electrode assembly. For this reason, when low-humidity hydrogen gas is used, a configuration in which the hydrogen gas is humidified before being supplied to the fuel cell is widely adopted.

[0003] For example, the following patent document discloses an invention of a fuel cell evaluation test apparatus (hereinafter also simply referred to as "test apparatus") that performs a performance evaluation test of a fuel cell by adjusting supply conditions such as temperature and humidity of gases supplied from a gas supply device to the fuel cell, the gases including "oxygen-containing gas (positive electrode side gas: cathode gas)" and "hydrogen-containing gas (negative electrode side gas: anode gas), hereinafter also referred to as "air" and "hydrogen gas". In this test apparatus, the gas supply device includes a humidification means that adjusts (humidifies) the humidity of air and hydrogen gas, a flow rate adjustment means that adjusts the flow rate of gas that passes through the humidification means (gas to be humidified), and a flow rate adjustment means that adjusts the flow rate of gas that does not pass through the humidification means (non-humidified gas), and is configured such that the humidity of the gas supplied to the fuel cell can be adjusted by adjusting the mixing ratio of the gas humidified by the humidification means and the non-humidified gas (adjusting the passage amount of gas by both flow rate adjustment means).

[0004] In this case, the humidification means comprises a sealed storage tank for storing water (e.g., pure water) and a heater (electric heater: water temperature adjustment means) for heating the water in the storage tank. By discharging gas into the stored water from a gas inlet located at the bottom of the storage tank, the gas floating in the stored water is humidified (bubbled) and discharged from a gas outlet located at the top of the storage tank. As a result, in this test apparatus, by mixing gas sufficiently humidified by the humidification means with gas that is not humidified by the humidification means in any ratio and supplying it to the fuel cell, it is possible to reproduce power generation under conditions where excessive drying of the membrane electrode assembly does not occur, as well as power generation under conditions where excessive drying of the membrane electrode assembly occurs, or where excessive wetting of the membrane electrode assembly occurs. [Prior art documents] [Patent Documents]

[0005] [Patent Document 1] Japanese Patent Publication No. 2019-210205 (pages 4-21, Figures 1-4D) [Overview of the Initiative] [Problems that the invention aims to solve]

[0006] However, the configuration of the test apparatus disclosed in the above-mentioned patent document has the following problems that need to be solved.

[0007] Specifically, the test apparatus disclosed in the above-mentioned patent document employs a configuration in which a portion of the gas supplied to the fuel cell is humidified when it is brought up from the stored water in the humidification means (storage tank). In this case, the humidification means of this test apparatus employs a configuration in which the temperature and humidity of the gas are adjusted by heating the stored water in the storage tank with an electric heater. Therefore, if the configuration of the test apparatus disclosed in this patent document is adopted in an actual power generation system using a fuel cell, electricity will be consumed by the electric heater to heat the water (storage water in the above-mentioned document) used to humidify the hydrogen gas, etc., in the power generation system for obtaining electricity, which will lead to a decrease in the power generation efficiency of the power generation system as a whole.

[0008] Furthermore, when generating electricity using a fuel cell, the temperature of the power generation cell changes sequentially in response to changes in the power generation environment, such as the elapsed time since the start of power generation and the amount of electricity generated. In this case, when a gas adjusted to a humidity suitable for power generation under a certain power generation environment is supplied to the power generation cell, if the temperature of the power generation cell rises higher than expected, the temperature of the supplied gas will rise and the relative humidity will decrease. Conversely, if the temperature of the power generation cell falls lower than expected, the temperature of the supplied gas will decrease, the relative humidity will rise, or some of the water will change into the liquid phase. As a result, in either case, there is a risk of a decrease in power generation efficiency. To avoid this, complicated control is required, such as changing the amount of electricity supplied to the electric heater according to the temperature of the power generation cell, adjusting the water temperature in the humidifying water tank (the temperature of the stored water in the storage tank in the configuration of the above-mentioned patent document), or adjusting the mixing ratio.

[0009] This invention has been made in view of the problems that need to be solved, and its main objective is to provide a power generation system that can sufficiently improve power generation efficiency without requiring complicated control. [Means for solving the problem]

[0010] To achieve the above objective, the power generation system according to claim 1 comprises a first separator through which a first gas containing an oxidizing agent passes, a second separator through which a second gas containing hydrogen passes, and a device disposed between the first separator and the second separator. membrane A power generation system comprising a power generation cell configured to generate electricity by reacting a first gas with a second gas via the film electrode assembly, wherein a plurality of flat laminated objects, each containing at least an electrode assembly, are stacked and integrated, and the first gas with the second gas is reacted via the electrode assembly, A first suction pump that introduces new first gas into the first separator by sucking the first gas from the first separator, and a gas-liquid separation tank that separates the mixture of the first gas and water discharged from the first separator into the first gas and the water, A humidifier having a water tank through which the second gas supplied to the second separator can pass, and humidifying the second gas passing through the water tank. and The humidifier is equipped with, The gas-liquid separation tank is configured to allow the separated water to be stored in the water storage tank, Discharged from the first separator and are separated in the gas-liquid separation tank. A first heat exchange unit that heats the water in the water tank by heat exchange with the first gas. and a second heat exchange unit that heats the water in the water tank by heat exchange with the first gas discharged from the first suction pump. Equipped with The first heat exchange unit is configured to heat the water in the water tank by heat exchange with the first gas passing through the first spiral pipe, and includes a first spiral pipe housed in the water tank so as to be immersed in the water in the water tank. The second heat exchange unit is configured to heat the water in the water tank by heat exchange with the first gas passing through the second spiral pipe, and includes a second spiral pipe housed in the water tank so as to be immersed in the water in the water tank. It is.

[0011] The power generation system according to claim 2 is the power generation system according to claim 1, The humidifier comprises a nozzle capable of discharging the second gas into the water tank, and a number of spheres formed in a small spherical shape and housed within the water tank so as to provide buoyancy to the water stored in the tank. The second gas discharged from the nozzle is allowed to float in the water stored in the tank before passing through the number of spheres and being supplied to the second separator. .

[0012] The power generation system according to claim 3 is the power generation system according to claim 1, further comprising a third heat exchange unit that heats the second gas introduced into the humidifier by heat exchange with the first gas discharged from the first separator.

[0013] The power generation system according to claim 4 is 1 The power generation system described includes a fourth heat exchange unit that heats the second gas introduced into the humidifier by heat exchange with the first gas discharged from the first suction pump.

[0014] The power generation system according to claim 5 is the power generation system according to claim 1, further comprising a fifth heat exchange unit that heats the second gas discharged from the humidifier by heat exchange with the first gas discharged from the first separator.

[0015] The power generation system according to claim 6 is, 1 The power generation system described includes a sixth heat exchange unit that heats the second gas discharged from the humidifier by heat exchange with the first gas discharged from the first suction pump. [Effects of the Invention]

[0022] The power generation system according to claim 1 includes a water tank through which a second gas supplied to a second separator can pass, and a humidifier that humidifies the second gas passing through the water tank. This humidifier includes a first heat exchange unit that heats the water in the water tank by heat exchange with the first gas discharged from the first separator. Therefore, according to the power generation system according to claim 1, unlike a configuration in which the water for humidification is heated by an electric heater, the heat of the first gas (the first gas discharged from the first separator) whose temperature has risen due to the heat generated by the power generation cell during power generation is utilized. This allows the water in the water tank to be heated and made more easily vaporizable without consuming electricity to humidify the second gas, and the power generation efficiency of the power generation system can be sufficiently improved by suitably humidifying the second gas that can float in the water. Furthermore, as the supply of the second gas to the power generation cell increases, i.e., as the amount of power generated by the power generation system increases, the temperature of the power generation cell rises. This causes the temperature of the first gas discharged from the first separator to rise, and by heating the water through heat exchange with this first gas, the water can be heated more effectively when the amount of the second gas to be humidified by the humidifier is large. This allows the second gas to be humidified effectively without the need for complicated control. .Ma , Claim 1 The power generation system described includes a first suction pump that introduces a new first gas into the first separator by drawing a first gas from the first separator, and a humidifier that includes a second heat exchange unit that heats the water in the water tank by heat exchange with the first gas discharged from the first suction pump. 1According to the power generation system described, by utilizing not only the heat of the first gas whose temperature has risen due to the heat generated by the power generation cell, but also the heat of the first gas whose temperature has risen due to compression by the first suction pump and the mechanical heat generated by the first suction pump (the first gas discharged from the first suction pump), the water in the water tank can be heated more effectively without consuming electricity to humidify the second gas. Furthermore, as the amount of second gas supplied to the power generation cell increases, i.e., as the amount of power generated by the power generation system increases, the amount of first gas sucked (compressed) by the first suction pump also increases. As a result, the temperature of the first gas discharged from the first suction pump rises, and by heating the water through heat exchange with this first gas, the water can be heated more effectively, especially when the amount of second gas to be humidified by the humidifier is large.

[0023] Furthermore, in the power generation system described in claim 2, the second gas discharged from the nozzle is allowed to float in the water stored in the reservoir before passing through a number of spheres and being supplied to the second separator. Therefore, according to the power generation system described in claim 2, the second gas, which is discharged from the nozzle into the reservoir and floats to near the water surface in the reservoir, passes through the spheres and is discharged from the reservoir. This prevents a situation where a large amount of water in the reservoir is discharged along with the second gas G, and allows the humidified second gas to be supplied to the power generation cell.

[0024] Furthermore, the power generation system according to claim 3 includes a third heat exchange unit that heats the second gas introduced into the humidifier by heat exchange with the first gas discharged from the first separator. Therefore, according to the power generation system according to claim 3, the relative humidity of the second gas introduced into the humidifier is reduced by utilizing the heat of the first gas (the first gas discharged from the first separator) whose temperature has risen due to the heat generated by the power generation cell during power generation, thereby sufficiently increasing the hygroscopicity of the humidifier and enabling suitable humidification. As a result, even if the amount of water stored in the humidifier (water tank) is small, the second gas can be suitably humidified and drying up of the membrane electrode assembly in the power generation cell can be suitably avoided. Therefore, by using a small amount of water, the amount of heat consumed to heat the water (the amount of heat exchanged between the first gas discharged from the first separator and the water) can be small, and as a result, the situation in which there is insufficient heat to suitably humidify the second gas can be suitably avoided.

[0025] Further, in the power generation system according to claim 4, a fourth heat exchange section is provided which heats the second gas introduced into the humidifier by heat exchange with the first gas discharged from the first suction pump. Therefore, according to the power generation system of claim 4, not only the heat of the first gas whose temperature is increased by the heat generated by the power generation cell, but also the heat of the first gas whose temperature is increased by compression by the first suction pump and mechanical heat generation of the first suction pump (the first gas discharged from the first suction pump) can be used to sufficiently reduce the relative humidity of the second gas introduced into the humidifier. This makes it possible to reliably avoid a situation where the amount of heat required for suitably humidifying the second gas is insufficient.

[0026] Further, in the power generation system according to claim 5, a fifth heat exchange section is provided which heats the second gas discharged from the humidifier by heat exchange with the first gas discharged from the first separator. Therefore, according to the power generation system of claim 5, the heat of the first gas whose temperature is increased by heat generated from the power generation cell during power generation (the first gas discharged from the first separator) is used to reduce the relative humidity of the second gas introduced into the second separator, and a situation where dew condensation occurs in the hydrogen flow path can be suitably avoided.

[0027] Further, in the power generation system according to claim 6, a sixth heat exchange section is provided which heats the second gas discharged from the humidifier by heat exchange with the first gas discharged from the first suction pump. Therefore, according to the power generation system of claim 6, not only the heat of the first gas whose temperature is increased by the heat generated by the power generation cell, but also the heat of the first gas whose temperature is increased by compression by the first suction pump and mechanical heat generation of the first suction pump (the first gas discharged from the first suction pump) can be used to reduce the relative humidity of the second gas introduced into the second separator, and a situation where dew condensation occurs in the hydrogen flow path can be suitably avoided. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] [Figure 1] It is a configuration diagram showing the configuration of the power generation system 1. [Figure 2] This is an explanatory diagram illustrating the configuration of humidifier 4. [Figure 3] This is an explanatory diagram illustrating the configuration of the heating section 5a. [Figure 4] This is an explanatory diagram illustrating the configuration of the heating section 5b. [Modes for carrying out the invention]

[0035] The following describes an embodiment of the power generation system with reference to the attached drawings.

[0036] The power generation system 1 shown in Figure 1 is an example of a "power generation system" and is configured to generate electricity by reacting a gas for power generation (air (atmosphere: oxygen), which is an example of a "first gas containing an oxidizing agent," and hydrogen gas G, which is an example of a "second gas containing hydrogen"). In this example, the power generation system 1 employs a configuration in which hydrogen gas G supplied from a hydrogen gas supply source X, which consists of a hydrogen generator (not shown) installed together with the power generation system 1 at the installation site of the power generation system 1, hydrogen gas G produced by the hydrogen generator, or hydrogen gas G produced elsewhere and transported to the installation site of the power generation system 1 and stored therein, is used as the "second gas" to generate electricity.

[0037] This power generation system 1 includes a pump 2, a gas-liquid separation tank 3, a humidifier 4, heating units 5a, 5b, control valves 6a-6d, 7a-7d, 8a, 8b, a control unit 9, a fuel cell cell 10, and piping Pa1-Pa5, Pb0-Pb4, Pc1-Pc4, Pd0-Pd4, Pe1-Pe3, Pg1-Pg3, Pw1, Pw2.

[0038] The fuel cell cell 10 is an example of a "power generation cell configured to generate electricity by reacting a first gas and a second gas," and comprises a power generation stack consisting of a separator 11 (an example of a "first separator") through which air (the first gas) passes, a separator 12 (an example of a "second separator") through which hydrogen gas G (the second gas) passes, and an MEA 13 (an example of a "membrane electrode assembly") sandwiched between separators 11 and 12; a separator 14 (an example of a "third separator") for allowing a "third gas" (for example, air: atmosphere) to pass through for cooling; and end plates (not shown) disposed at both ends in the stacking direction of each stack. In this example, each plate, such as separators 11, 12, 14, MEA 13, and end plates, corresponds to "multiple flat plate-shaped stacked objects," and the fuel cell cell 10 is constructed by stacking and integrating these.

[0039] In this case, the separator 11 has grooves (not shown) for allowing air to pass through, and pipe Pa1 is connected to the air inlet, while the gas-liquid separation tank 3 is connected to the air outlet via pipe Pa2. The separator 12 also has grooves (not shown) for allowing hydrogen gas G to pass through, and a humidifier 4 is connected to the hydrogen gas G inlet via pipe Pg2, while pipe Pg3 is connected to the hydrogen gas G outlet. Downstream of pipe Pg3, a post-treatment device (not shown) is connected to the hydrogen gas G discharged from the separator 12 (a gas containing unreacted hydrogen that did not react with air during power generation) to perform the necessary treatment in the operating environment of the power generation system 1. The MEA 13 is composed of an electrolyte membrane, a catalyst layer, and a gas diffusion layer.

[0040] In this fuel cell cell 10, the MEA 13 is sandwiched between the two separators 11 and 12, and they are stacked in this manner. As a result, an air passage 11a is formed by the grooves of separator 11 and one surface of the MEA 13, and a hydrogen passage 12a is formed by the grooves of separator 12 and the other surface of the MEA 13. Separator 14 has an air passage 14a (pores) formed therein for passing cooling air. A pipe Pa4 is connected to the air inlet, and a pipe Pb0 (described later) is connected to the air outlet via a pipe Pa5. This configuration allows the separators 11 and 12 to be cooled by heat exchange with the air passing through the air passage 14a. In reality, a fuel cell cell 10 is configured with multiple power generation stacks (separators 11, 12, and MEA 13) and separators 14, depending on the power generation capacity required by the power generation system 1. However, to facilitate understanding of the configuration and operation of the power generation system 1, an example is shown in which one separator 14 is placed between two power generation stacks.

[0041] Pump 2 corresponds to "a first suction pump that introduces new first gas into the first separator by sucking first gas from the first separator" and "a second suction pump that introduces new third gas into the third separator by sucking third gas from the third separator" (an example of a configuration in which one pump is used as both the "first pump" and the "second pump"). As will be described later, pump 2 introduces new air into separators 11 and 14 by sucking air from separators 11 and 14 in accordance with the control of control unit 9. In this case, when power is generated by the power generation system 1, the temperature of the fuel cell cell 10 rises, so the air discharged from separators 11 and 14 (sucked in from fuel cell cell 10 by pump 2) also rises in temperature due to heat exchange with separators 11 and 14. Furthermore, while pump 2 is operating, its exhaust (air drawn in from fuel cell cell 10 and discharged from pump 2) rises in temperature due to compression by pump 2 and mechanical heat generated by pump 2. Therefore, in the power generation system 1 of this example, as will be described later, a configuration is adopted in which the heat from this air is used to heat the water W and hydrogen gas G in humidifier 4.

[0042] The gas-liquid separation tank 3 is configured to separate the exhaust gas (a mixture of air and water) discharged from the separator 11 and flowing in through the piping Pa2 into air and water. In this case, when generating power in the fuel cell cell 10, the air (oxygen) passing through the separator 11 (air passage 11a) reacts with the hydrogen gas G passing through the separator 12 (hydrogen passage 12a) to generate water in the air passage 11a, and this water is discharged from the separator 11 together with the exhaust gas (air that has reacted with hydrogen). Therefore, in the power generation system 1 of this example, in order to prevent a large amount of moisture from being drawn into the pump 2 and causing malfunction, the system is configured to draw in air from which moisture has been separated (moisture removed) from the air discharged from the separator 11 into the pump 2, and to store the water separated in the gas-liquid separation tank 3 in the water storage tank 4a described later and use it to humidify the hydrogen gas G. The gas-liquid separation tank 3 has the intake port of pump 2 connected to its upper part via piping Pa3, Pb0~Pb4, humidifier 4, heating units 5a, 5b, and piping Pc1~Pc4, and the water storage tank 4a of humidifier 4, which will be described later, is connected to its bottom via piping Pw1.

[0043] Humidifier 4 is an example of a "humidifier" and is configured to humidify the hydrogen gas G supplied from the hydrogen gas supply source X to the fuel cell cell 10 (separator 12). Specifically, as shown in Figure 2, humidifier 4 comprises a water storage tank 21, a nozzle 22, spheres 23, 23..., spiral tubes 24, 25 and a water storage tank 4a (see Figure 1), and is configured to humidify the hydrogen gas G passing through the water storage tank 21 by bubbling. The water storage tank 21 is a sealed container, which is an example of a "water storage tank," and is configured to store water W (for example, pure water) for humidifying the hydrogen gas G. The nozzle 22 is located at the bottom of the water storage tank 21 so that the hydrogen gas G supplied from the hydrogen gas supply source X via the piping Pg1 can be discharged into the water storage tank 21. The spheres 23, 23... are components for preventing liquid water W from being discharged from the water storage tank 21 into the piping Pg2 along with hydrogen gas G. They are formed in the shape of small spheres of a material and structure capable of generating buoyancy for the water W stored in the water storage tank 21 and are housed within the water storage tank 21.

[0044] The spiral tube 24 corresponds to "a first heat exchange section that heats the water in the water tank by heat exchange with a first gas discharged from the first separator" and "a heat exchange section A that heats the water in the water tank by heat exchange with a third gas discharged from the third separator" (an example of a configuration in which one heat exchange section is used for both "the first heat exchange section" and "heat exchange section A"). The spiral tube 24 is housed in the water tank 21 so as to be submerged in the water W stored in the water tank 21, and a pipe Pb1 is connected to one end of the spiral tube 24 and a pipe Pc1 is connected to the other end, so that air sucked in from the separators 11 and 14 by the pump 2 passes through it, thereby heating the water W by heat exchange between the air and the water W.

[0045] The spiral tube 25 corresponds to "a second heat exchange section that heats the water in the water tank by heat exchange with a first gas discharged from the first suction pump" and "a heat exchange section B that heats the water in the water tank by heat exchange with a third gas discharged from the second suction pump" (an example of a configuration in which one heat exchange section is used for both "the second heat exchange section" and "heat exchange section B"). Similar to the spiral tube 24, the spiral tube 25 is housed in the water tank 21 so as to be submerged in the water W stored in the water tank 21, and a pipe Pd1 is connected to one end of the spiral tube 25 and a pipe Pe1 is connected to the other end, so that air discharged from the pump 2 and pumped through pipes Pd0 and Pd1 passes through it, thereby heating the water W through heat exchange between the air and the water W.

[0046] As shown in Figure 1, the water storage tank 4a is connected to the water storage tank 21 via piping Pw2, and is configured to store water W that has been pre-filled or water W separated in the gas-liquid separation tank 3 as described above, and to supply water W to the water storage tank 21 via piping Pw2. In this case, as an example, the power generation system 1 of this example is equipped with a water level sensor that detects the amount of water W stored in the water storage tank 21, and the control unit 9 controls the control valve 8b installed in piping Pw2 to open when the water level of water W in the water storage tank 21 falls below a specified amount based on the sensor signal from the water level sensor, thereby supplying water W from the water storage tank 4a to the water storage tank 21. In addition, as an example, the power generation system 1 of this example is configured such that the water storage tank 4a is located above the water storage tank 21, and the water W in the water storage tank 4a flows into the water storage tank 21 via piping Pw2 due to its own weight. Furthermore, if it is difficult to install the water storage tank 4a above the water storage tank 21, a configuration can be adopted in which a liquid transfer pump is installed in the piping Pw2 to allow the water W in the water storage tank 4a to flow into the water storage tank 21.

[0047] As shown in Figure 3, the heating section 5a includes a spiral tube 31, which is an example of a "third heat exchange section that heats the second gas introduced into the humidifier by heat exchange with the first gas discharged from the first separator" and a "heat exchange section C that heats the second gas introduced into the humidifier by heat exchange with the third gas discharged from the third separator" (an example of a configuration in which one heat exchange section is used as both the "third heat exchange section" and "heat exchange section C"), a spiral tube 32, which is an example of a "fourth heat exchange section that heats the second gas introduced into the humidifier by heat exchange with the first gas discharged from the first suction pump" and a "heat exchange section D that heats the second gas introduced into the humidifier by heat exchange with the third gas discharged from the second suction pump" (an example of a configuration in which one heat exchange section is used as both the "fourth heat exchange section" and "heat exchange section D"), and an insulating material 33.

[0048] In this heating section 5a, pipe Pg1 is inserted through the winding centers of both spiral pipes 31 and 32, and both spiral pipes 31 and 32, as well as pipe Pg1 through which they are inserted, are covered with insulating material 33 to insulate them from the surrounding air. In this case, pipe Pb2, which is connected to pipe Pb0, is connected to one end of spiral pipe 31, and pipe Pc2, which is connected to pipe Pc4, is connected to the other end. Also, pipe Pd2, which is connected to pipe Pd0, is connected to one end of spiral pipe 32, and pipe Pe2, whose one end is open to the atmosphere, is connected to the other end.

[0049] As shown in Figure 4, the heating section 5b includes a spiral tube 41, which is an example of a "fifth heat exchange section that heats the second gas discharged from the humidifier by heat exchange with the first gas discharged from the first separator" and a "heat exchange section E that heats the second gas discharged from the humidifier by heat exchange with the third gas discharged from the third separator" (an example of a configuration in which one heat exchange section is used as both the "fifth heat exchange section" and the "heat exchange section E"), a spiral tube 42, which is an example of a "sixth heat exchange section that heats the second gas discharged from the humidifier by heat exchange with the first gas discharged from the first suction pump" and a "heat exchange section F that heats the second gas discharged from the humidifier by heat exchange with the third gas discharged from the second suction pump" (an example of a configuration in which one heat exchange section is used as both the "sixth heat exchange section" and the "heat exchange section F"), and an insulating material 43.

[0050] In this heating section 5b, pipe Pg2 is inserted through the winding centers of both spiral pipes 41 and 42, and both spiral pipes 41 and 42, as well as pipe Pg2 through which they are inserted, are covered with insulating material 43 to insulate them from the surrounding air. Furthermore, pipe Pb3, which is connected to pipe Pb0, is connected to one end of spiral pipe 41, and pipe Pc3, which is connected to pipe Pc4, is connected to the other end. Similarly, pipe Pd3, which is connected to pipe Pd0, is connected to one end of spiral pipe 42, and pipe Pe3, whose one end is open to the atmosphere, is connected to the other end.

[0051] As shown in Figure 1, control valve 6a is located in the piping Pb1 and, according to the control of the control unit 9, adjusts the amount of air drawn in from separators 11 and 14 by the pump 2 into the humidifier 4 (spiral pipe 24) (the amount of air that can pass through the water storage tank 21). Control valve 6b is located in the piping Pb2 and, according to the control of the control unit 9, adjusts the amount of air drawn in from separators 11 and 14 by the pump 2 into the heating section 5a (spiral pipe 31). Control valve 6c is located in the piping Pb3 and, according to the control of the control unit 9, adjusts the amount of air drawn in from separators 11 and 14 by the pump 2 into the heating section 5b (spiral pipe 41). The control valve 6d is located in pipe Pb4, which is directly connected to the above-mentioned pipes Pb0 and Pc4. In accordance with the control of the control unit 9, it adjusts the amount of air drawn in from separators 11 and 14 by the pump 2 that flows into the pump 2 without passing through the humidifier 4 or heating units 5a and 5b.

[0052] Control valve 7a is located in the piping Pd1 described above and, in accordance with the control unit 9, adjusts the amount of air discharged from pump 2 into humidifier 4 (spiral pipe 25) (the amount of air that can pass through the water storage tank 21). Control valve 7b is located in the piping Pd2 described above and, in accordance with the control unit 9, adjusts the amount of air discharged from pump 2 into heating section 5a (spiral pipe 32). Control valve 7c is located in the piping Pd3 described above and, in accordance with the control unit 9, adjusts the amount of air discharged from pump 2 into heating section 5b (spiral pipe 42). Control valve 7d is located in piping Pd4 which directly releases air discharged from pump 2 into the atmosphere via piping Pd0 and, in accordance with the control unit 9, adjusts the amount of air discharged from pump 2 that is released into the atmosphere without passing through humidifier 4 or heating sections 5a and 5b.

[0053] Control valve 8a is installed in the above-mentioned piping Pw1 and, according to the control of the control unit 9, allows / regulates the flow of water W from the gas-liquid separation tank 3 to the water storage tank 4a. Control valve 8b is installed in the above-mentioned piping Pw2 and, according to the control of the control unit 9, allows / regulates the inflow of water W from the water storage tank 4a to the water storage tank 21.

[0054] The control unit 9 comprehensively controls the power generation system 1. Specifically, the control unit 9 controls the pump 2 to draw air from the separators 11 and 14, thereby introducing fresh air into the separators 11 and 14. In this example of the power generation system 1, as an example, the control unit 9 adjusts the flow rate of hydrogen gas G introduced from the hydrogen gas supply source X to the fuel cell cell 10 (separator 12) by adjusting the opening of a flow control valve (not shown) installed in the above-mentioned piping Pg1. However, in order to facilitate understanding of the configuration and operation of the power generation system 1, a detailed explanation of the flow rate adjustment of hydrogen gas G is omitted.

[0055] Furthermore, the control unit 9 controls the control valves 6a-6d and 7a-7d according to the power generation environment in the fuel cell cell 10, as described later, to adjust the amount of air passing through the humidifier 4 and heating units 5a and 5b. In this example, the power generation system 1 includes, as an example, a temperature sensor for detecting the temperature of the fuel cell cell 10, a temperature sensor for detecting the temperature of the hydrogen gas G supplied to the fuel cell cell 10 (separator 12), a temperature sensor for detecting the temperature of the water W in the humidifier 4, and a temperature sensor for detecting the temperature of the air discharged from the pump 2 (none of which are shown). The control unit 9 controls the control valves 6a-6d and 7a-7d according to the temperatures detected by these temperature sensors. The control of the pump 2 by the control unit 9, the flow rate adjustment of the hydrogen gas G, and the control of the control valves 6a-6d and 7a-7d will be described in detail later.

[0056] In this power generation system 1, as described above, electricity is generated by reacting air (oxygen) and hydrogen gas G (hydrogen) in the fuel cell cell 10. Specifically, when the start of power generation is instructed by operating an operation unit (not shown), the control unit 9 controls the pump 2 to start drawing in air (oxygen). In this case, since it is immediately after the start of power generation and the temperature of the fuel cell cell 10 and pump 2 has not risen, the control unit 9, as an example, moves control valves 6a to 6c to the closed state and control valve 6d to the open state, and moves control valves 7a to 7c to the closed state and control valve 7d to the open state.

[0057] In this process, air is drawn from separator 11 (air passage 11a) via piping Pc4, Pb4, Pb0, Pa3, gas-liquid separation tank 3, and piping Pa2, and new air is introduced into separator 11 (air passage 11a) via piping Pa1. At the same time, air is drawn from separator 14 (air passage 14a) via piping Pc4, Pb4, Pb0, Pa5, and new air is introduced into separator 14 (air passage 14a) via piping Pa4. The air drawn into pump 2 is then released into the atmosphere via piping Pd0 and Pd4.

[0058] In this state, by starting the supply of hydrogen gas G from the hydrogen gas supply source X, this hydrogen gas G is introduced into the separator 12 (hydrogen channel 12a) via piping Pg1, humidifier 4, and piping Pg2. The hydrogen gas G introduced into the separator 12 is then passed through the hydrogen channel 12a and sent via piping Pg3 to a post-treatment device (not shown). As a result, electricity is generated by the reaction between the air (oxygen) passing through the air channel 11a and the hydrogen gas G (hydrogen) passing through the hydrogen channel 12a.

[0059] In this case, the power generation system 1 of this example employs a configuration in which the hydrogen gas G discharged from the hydrogen gas supply source X is humidified in the humidifier 4 before being supplied to the fuel cell cell 10 (separator 12) in order to prevent the MEA 13 from drying up and causing a decrease in power generation efficiency when the hydrogen gas G discharged from the hydrogen gas supply source X is supplied to the fuel cell cell 10 (separator 12). Specifically, the hydrogen gas G supplied from the hydrogen gas supply source X to the humidifier 4 via piping Pg1 and discharged into the water tank 21 from the nozzle 22 absorbs moisture as it floats in the water W in the water tank 21, thereby increasing its relative humidity. The hydrogen gas G that has floated to near the water surface passes between each sphere 23, 23... and is discharged into the piping. As a result, the humidified hydrogen gas G is supplied to the fuel cell cell 10 (separator 12) via piping Pg2 without causing a situation in which a large amount of water W in the water tank 21 is discharged together with the hydrogen gas G.

[0060] Here, for a while after starting power generation, the amount of hydrogen gas G supplied to the fuel cell cell 10 is small, so the hydrogen gas G can be sufficiently humidified by floating it in the room temperature water W in the humidifier 4 (water storage tank 21). However, in order to transition the power generation system 1 to a steady-state operation and increase the amount of power generated, it becomes necessary to supply a large amount of hydrogen gas G to the fuel cell cell 10 to react with a large amount of air (oxygen). Therefore, simply floating it in the room temperature water W makes it difficult to sufficiently humidify the hydrogen gas G supplied to the fuel cell cell 10. Thus, in the power generation system 1 of this example, when increasing the amount of hydrogen gas G supplied to the fuel cell cell 10, a configuration is adopted in which the temperature of the water W and the temperature of the hydrogen gas G itself are raised to maintain a suitable humidity (sufficient humidity that does not cause the MEA 13 to dry out).

[0061] Specifically, when air is drawn in by pump 2 at the start of power generation, the temperature of the air discharged into piping Pd0 rises due to compression by pump 2 and mechanical heat generated by pump 2. Therefore, in the power generation system 1 of this example, a configuration is adopted in which the hydrogen gas G supplied to the separator 12 is sufficiently humidified by heating water W or hydrogen gas G using the heat of the air discharged from pump 2. More specifically, the control unit 9 first moves control valves 7a to 7c to the open state and control valve 7d to the closed state. At this time, the high-temperature air discharged from pump 2 into piping Pd0 is supplied to the humidifier 4 via piping Pd1, supplied to the heating unit 5a via piping Pd2, and supplied to the heating unit 5b via piping Pd3.

[0062] In this process, in the humidifier 4, the air supplied via the piping Pd1 passes through the spiral tube 25, causing the water W in the water tank 21 to be heated through heat exchange with the air in the spiral tube 25. This makes the water W more readily convertible to a gaseous state, and the hydrogen gas G that is sprayed into the water W from the nozzle 22 and floats within the water W is effectively humidified. The air that has been cooled by heat exchange with the water W after passing through the spiral tube 25 is then released into the atmosphere via the piping Pe1.

[0063] Furthermore, in the heating section 5a, the air supplied via the piping Pd2 passes through the spiral tube 32, causing the hydrogen gas G flowing from the hydrogen gas supply source X towards the humidifier 4 through the piping Pg1 through which the spiral tube 32 is inserted to have its temperature increased through heat exchange with the air inside the spiral tube 32. As a result, the relative humidity of the hydrogen gas G introduced into the humidifier 4 (water tank 21) decreases, making it easier for the humidifier 4 to absorb moisture. In addition, when the hydrogen gas G whose temperature has been raised in the heating section 5a is introduced into the humidifier 4, the water W in the water tank 21 also has its temperature raised, making it easier for the water W to change into the gas phase. Therefore, it becomes possible to sufficiently humidify the hydrogen gas G in the humidifier 4. The air whose temperature has been lowered through heat exchange with the hydrogen gas G after passing through the spiral tube 32 is released into the atmosphere via the piping Pe2.

[0064] Furthermore, in the heating section 5b, the air supplied via the piping Pd3 passes through the spiral tube 42, causing the hydrogen gas G flowing from the humidifier 4 towards the fuel cell cell 10 (separator 12) through the piping Pg2 through which the spiral tube 42 is inserted to have its temperature increased by heat exchange with the air inside the spiral tube 42. In this case, the hydrogen gas G, which has been sufficiently humidified in the humidifier 4, has a relative humidity of approximately 100% when it is discharged from the humidifier 4 into the piping Pg2. Therefore, if the hydrogen gas G humidified in the humidifier 4 is supplied directly to the fuel cell cell 10 (separator 12), condensation may occur due to changes in temperature and pressure inside the piping Pg2 or the separator 12, and the presence of liquid-phase moisture in the hydrogen flow path 12a may obstruct the passage of hydrogen gas G. Therefore, in the power generation system 1 of this example, a configuration is adopted in which the relative humidity is reduced by raising the temperature of the hydrogen gas G humidified in the humidifier 4 before supplying it to the separator 12. This makes it possible to avoid condensation occurring due to changes in temperature and humidity inside the piping Pg2 or the separator 12. In addition, the air that has passed through the spiral pipe 42 and whose temperature has been reduced by heat exchange with the hydrogen gas G is released into the atmosphere through the piping Pe3.

[0065] On the other hand, after a certain amount of time has passed since power generation began, the temperature of the fuel cell cell 10 rises due to the heat generated by the reaction between air (oxygen) and hydrogen gas G (hydrogen). As a result, the temperature of the air discharged from the separators 11 and 14 rises due to heat exchange with the fuel cell cell 10 (separators 11 and 14). Therefore, in the power generation system 1 of this example, a configuration is adopted in which the hydrogen gas G supplied to the separator 12 is sufficiently heated by using the thermal energy of the air discharged from the separators 11 and 14 to heat the water W and hydrogen gas G.

[0066] Specifically, the control unit 9 opens control valves 6a to 6c and closes control valve 6d. At this time, the high-temperature air discharged from separator 11 to pipe Pa2 and reaching pipe Pb0 via gas-liquid separation tank 3 and pipe Pa3 is combined with the high-temperature air discharged from separator 14 to pipe Pa5 and reaching pipe Pb0. This combined air is then supplied to humidifier 4 via pipe Pb1, to heating unit 5a via pipe Pb2, and to heating unit 5b via pipe Pb3.

[0067] In this process, in the humidifier 4, the air supplied via piping Pb1 passes through the spiral tube 24, causing the water W in the water tank 21 to be heated by heat exchange with the air in the spiral tube 24. This makes the water W more readily convertible to a gaseous state, and the hydrogen gas G that is sprayed into the water W from the nozzle 22 and floats within the water W is effectively humidified. The air that has been cooled by heat exchange with the water W after passing through the spiral tube 24 is then drawn into the pump 2 via piping Pc1 and Pc4.

[0068] Furthermore, in the heating section 5a, the air supplied via pipe Pb2 passes through the spiral tube 31, causing the hydrogen gas G flowing from the hydrogen gas supply source X toward the humidifier 4 through pipe Pg1 (in which the spiral tube 31 is inserted) to be heated by heat exchange with the air inside the spiral tube 31. As a result, the relative humidity of the hydrogen gas G introduced into the humidifier 4 (water tank 21) decreases, making it easier for the humidifier 4 to absorb moisture. In addition, the water W in the water tank 21 is also heated by heat exchange with the hydrogen gas G heated in the heating section 5a, resulting in the water W being more easily converted to the gas phase. Therefore, the hydrogen gas G can be sufficiently humidified in the humidifier 4. The air that has passed through the spiral tube 31 and whose temperature has decreased due to heat exchange with the hydrogen gas G is then drawn into the pump 2 via pipes Pc2 and Pc4.

[0069] Furthermore, in the heating section 5b, the air supplied via pipe Pb3 passes through the spiral tube 41, causing the hydrogen gas G flowing from the humidifier 4 towards the fuel cell cell 10 (separator 12) through pipe Pg2, which is through which the spiral tube 41 is inserted, to have its temperature increased through heat exchange with the air inside the spiral tube 41. As a result, the relative humidity of the hydrogen gas G humidified in the humidifier 4 is reduced before it is supplied to the separator 12, making it possible to avoid condensation caused by changes in temperature and humidity inside pipe Pg2 or the separator 12. The air that has passed through the spiral tube 41 and had its temperature reduced through heat exchange with the hydrogen gas G is then drawn into the pump 2 via pipes Pc3 and Pc4.

[0070] In practice, the control unit 9 adjusts the humidity of the hydrogen gas G supplied to the fuel cell 10 (separator 12) by arbitrarily opening and closing control valves 6a-6d and 7a-7d according to the amount of hydrogen gas G supplied to the fuel cell 10 (separator 12), the temperature of the hydrogen gas G discharged from the hydrogen gas supply source X, the temperature of the water W in the water storage tank 21, and the temperature of the hydrogen gas G supplied to the fuel cell 10 (separator 12). For example, when the amount of hydrogen gas G supplied to the separator 12 is small and the hydrogen gas G can be sufficiently humidified by the room temperature water W in the humidifier 4, either one or both of the control valves 6a and 7a are closed to continue power generation without heating the water W, or either one or both of the control valves 6b and 7b are closed to continue power generation without heating the hydrogen gas G.

[0071] Furthermore, when the temperature of the hydrogen gas G discharged from the hydrogen gas supply source X is sufficiently high and its hygroscopicity is sufficiently high, either or both of the control valves 6b and 7b are closed to continue power generation without heating the hydrogen gas G. Also, when the temperature of the water W in the water storage tank 21 is sufficiently high and it is in a state where it is easily converted to the gas phase, either or both of the control valves 6a and 7a are closed to continue power generation without heating the water W. Furthermore, when the temperature of the hydrogen gas G supplied to the fuel cell cell 10 (separator 12) is sufficiently high and there is no risk of condensation occurring in the piping Pg2 or separator 12, either or both of the control valves 6c and 7c are closed to continue power generation without heating the hydrogen gas G. Through these controls, it is possible to generate power without causing the MEA 13 to dry up, regardless of changes in the amount of power generated (i.e., the amount of hydrogen gas G supplied to the fuel cell cell 10) or changes in the operating environment of the power generation system 1 (changes in ambient temperature, etc.).

[0072] On the other hand, in this type of power generation system, water is generated in the air passage due to the reaction of oxygen and hydrogen in the fuel cell. In this case, the air containing liquid-phase water may be drawn into the pump, potentially causing the pump to malfunction. For this reason, the power generation system 1 in this example employs a configuration in which the water W generated in the fuel cell cell 10 (separator 11) during power generation is separated from the air and removed in the gas-liquid separation tank 3. Specifically, when air containing liquid-phase water W (water droplets) generated during power generation is discharged from the separator 11, this air flows into the gas-liquid separation tank 3 via the piping Pa2, where it is separated into air and water W. The separated water W is stored in the gas-liquid separation tank 3, and the air is discharged from the gas-liquid separation tank 3 into the piping Pa3 and, as described above, is drawn into the pump 2 along with the air discharged from the separator 14. This effectively avoids the situation in which air containing water W (water droplets) is drawn into the pump 2.

[0073] Furthermore, in the power generation system 1 of this example, a configuration is adopted in which the water W separated in the gas-liquid separation tank 3 is used for humidification in the humidifier 4. Specifically, when the control unit 9 determines that a specified amount of water W has been stored in the gas-liquid separation tank 3 based on the sensor signal from a water level sensor (not shown) installed in the gas-liquid separation tank 3, it controls the control valve 8a to the open state. At this time, the water W in the gas-liquid separation tank 3 is transferred to the water storage tank 4a via the pipe Pw1 by a liquid transfer pump (not shown) installed in the pipe Pw1, or by the weight of the water W itself. As a result, when the amount of water W stored in the humidifier 4 (water storage tank 21) falls below a specified amount, the control unit 9 controls the control valve 8b to the open state, thereby maintaining a condition in which sufficient water W is supplied from the water storage tank 4a to the water storage tank 21 via the pipe Pw2, allowing for suitable humidification of the hydrogen gas G.

[0074] Thus, this power generation system 1 has a water storage tank 21 through which hydrogen gas G supplied to the separator 12 can pass, and a humidifier 4 that humidifies the hydrogen gas G passing through the water storage tank 21. This humidifier 4 is equipped with a spiral tube 24 that heats the water W in the water storage tank 21 through heat exchange with the air discharged from the separator 11. Therefore, with this power generation system 1, unlike configurations that heat the water for humidification with an electric heater, the heat of the air (air discharged from the separator 11) whose temperature has risen due to the heat generated by the fuel cell cell 10 during power generation is utilized, thereby heating the water W in the water storage tank 21 to a state that is easily vaporized without consuming electricity to humidify the hydrogen gas G, and the hydrogen gas G that can float in this water W is appropriately humidified, thereby sufficiently improving the power generation efficiency of the power generation system 1. Furthermore, as the amount of hydrogen gas G supplied to the fuel cell 10 increases, that is, as the amount of power generated by the power generation system 1 increases, the temperature of the fuel cell 10 rises. As a result, the temperature of the air discharged from the separator 11 rises, and by exchanging heat with this air, the water W is heated, so that the water W can be heated more effectively when the amount of hydrogen gas G to be humidified by the humidifier 4 is large. This allows for effective humidification of the hydrogen gas G without the need for complex control.

[0075] Furthermore, this power generation system 1 is equipped with a pump 2 that introduces new air into the separator 11 by drawing air from the separator 11, and a humidifier 4 is equipped with a spiral tube 25 that heats the water W in the water storage tank 21 by heat exchange with the air discharged from the pump 2.Therefore, with this power generation system 1, by utilizing not only the heat of the air whose temperature has risen due to the heat generated by the fuel cell cell 10, but also the heat of the air whose temperature has risen due to compression by the pump 2 and the mechanical heat generated by the pump 2 (air discharged from the pump 2), the water W in the water storage tank 21 can be heated more effectively without consuming electricity to humidify the hydrogen gas G.In addition, in accordance with the increase in the amount of hydrogen gas G supplied to the fuel cell cell 10, that is, the increase in the amount of power generated by the power generation system 1, the amount of air drawn in (compressed) by the pump 2 also increases, and as a result the temperature of the air discharged from the pump 2 rises, the water W can be heated more effectively by heat exchange with this air, especially when the amount of hydrogen gas G to be humidified by the humidifier 4 is large.

[0076] Furthermore, this power generation system 1 is equipped with a heating section 5a having a spiral tube 31 that heats the hydrogen gas G introduced into the humidifier 4 by heat exchange with the air discharged from the separator 11. Therefore, with this power generation system 1, the relative humidity of the hydrogen gas G introduced into the humidifier 4 is reduced by utilizing the heat of the air (air discharged from the separator 11) whose temperature has risen due to the heat generated by the fuel cell cell 10 during power generation, thereby sufficiently increasing the hygroscopicity of the humidifier 4 and enabling suitable humidification. As a result, even if the amount of water W stored in the humidifier 4 (water tank 21) is small, the hydrogen gas G can be suitably humidified and the drying up of the MEA 13 in the fuel cell cell 10 can be suitably avoided. Therefore, by keeping the amount of water W stored small, the amount of heat consumed to heat the water W (amount of heat exchange between the air discharged from the separator 11 and the water W) can be small, and as a result, the situation in which there is insufficient heat to suitably humidify the hydrogen gas G can be suitably avoided.

[0077] Furthermore, this power generation system 1 is equipped with a spiral tube 32 that heats the hydrogen gas G introduced into the humidifier 4 through heat exchange with the air discharged from the pump 2. Therefore, with this power generation system 1, it is possible to sufficiently lower the relative humidity of the hydrogen gas G introduced into the humidifier 4 by utilizing not only the heat of the air whose temperature has risen due to the heat generated by the fuel cell cell 10, but also the heat of the air whose temperature has risen due to compression by the pump 2 and the mechanical heat generated by the pump 2 (the air discharged from the pump 2). This ensures that a situation in which there is insufficient heat to adequately humidify the hydrogen gas G can be avoided.

[0078] Furthermore, this power generation system 1 includes a heating section 5b having a spiral tube 41 that heats the hydrogen gas G discharged from the humidifier 4 through heat exchange with the air discharged from the separator 11. Therefore, with this power generation system 1, the relative humidity of the hydrogen gas G introduced into the separator 12 can be reduced by utilizing the thermal energy of the air (air discharged from the separator 11) whose temperature has risen due to the heat generated by the fuel cell cell 10 during power generation, thereby effectively avoiding condensation occurring in the hydrogen flow path 12a and other areas.

[0079] Furthermore, this power generation system 1 includes a heating section 5b having a spiral tube 42 that heats the hydrogen gas G discharged from the humidifier 4 through heat exchange with the air discharged from the pump 2. Therefore, with this power generation system 1, the relative humidity of the hydrogen gas G introduced into the separator 12 can be reduced by utilizing not only the heat of the air whose temperature has risen due to the heat generated by the fuel cell cell 10, but also the heat of the air whose temperature has risen due to compression by the pump 2 and the mechanical heat generated by the pump 2 (air discharged from the pump 2), thereby effectively avoiding condensation occurring in the hydrogen flow path 12a, etc.

[0080] Furthermore, this power generation system 1 has a water storage tank 21 through which hydrogen gas G supplied to the separator 12 can pass, and a humidifier 4 that humidifies the hydrogen gas G passing through the water storage tank 21. This humidifier 4 is equipped with a spiral tube 24 that heats the water W in the water storage tank 21 through heat exchange with the air discharged from the separator 14. Therefore, with this power generation system 1, unlike configurations that heat the water for humidification with an electric heater, the heat from the air (air discharged from the separator 14) whose temperature has risen due to the heat generated by the fuel cell cell 10 during power generation is utilized, thereby heating the water W in the water storage tank 21 to a state that is easily vaporized without consuming electricity to humidify the hydrogen gas G, and thereby suitably humidifying the hydrogen gas G that can float in the water W, thereby sufficiently improving the power generation efficiency of the power generation system 1. Furthermore, as the amount of hydrogen gas G supplied to the fuel cell 10 increases, that is, as the amount of power generated by the power generation system 1 increases, the temperature of the fuel cell 10 rises. As a result, the temperature of the air discharged from the separator 14 rises, and by heating the water W through heat exchange with this air, the water W can be heated more effectively when the amount of hydrogen gas G to be humidified by the humidifier 4 is large. This allows for effective humidification of the hydrogen gas G without the need for complex control.

[0081] Furthermore, this power generation system 1 is equipped with a pump 2 that introduces new air into the separator 14 by drawing air from the separator 14, and a humidifier 4 is equipped with a spiral tube 25 that heats the water W in the water storage tank 21 by heat exchange with the air discharged from the pump 2.Therefore, with this power generation system 1, by utilizing not only the heat of the air whose temperature has risen due to the heat generated by the fuel cell cell 10, but also the heat of the air whose temperature has risen due to compression by the pump 2 and the mechanical heat generated by the pump 2 (air discharged from the pump 2), the water W in the water storage tank 21 can be heated more effectively without consuming electricity to humidify the hydrogen gas G.In addition, in accordance with the increase in the amount of hydrogen gas G supplied to the fuel cell cell 10, that is, the increase in the amount of power generated by the power generation system 1, the amount of air drawn in (compressed) by the pump 2 also increases, and as a result the temperature of the air discharged from the pump 2 rises, the water W can be heated more effectively by heat exchange with this air, especially when the amount of hydrogen gas G to be humidified by the humidifier 4 is large.

[0082] Furthermore, this power generation system 1 is equipped with a heating section 5a having a spiral tube 31 that heats the hydrogen gas G introduced into the humidifier 4 by heat exchange with the air discharged from the separator 14. Therefore, with this power generation system 1, the relative humidity of the hydrogen gas G introduced into the humidifier 4 is reduced by utilizing the heat of the air (air discharged from the separator 14) whose temperature has risen due to the heat generated by the fuel cell cell 10 during power generation, thereby sufficiently increasing the hygroscopicity of the humidifier 4 and enabling suitable humidification. As a result, even if the amount of water W stored in the humidifier 4 (water tank 21) is small, the hydrogen gas G can be suitably humidified and the drying up of the MEA 13 in the fuel cell cell 10 can be suitably avoided. Therefore, by keeping the amount of water W stored small, the amount of heat consumed to heat the water W (amount of heat exchange between the air discharged from the separator 14 and the water W) can be small, and as a result, the situation in which there is insufficient heat to suitably humidify the hydrogen gas G can be suitably avoided.

[0083] Furthermore, this power generation system 1 includes a heating section 5a having a spiral tube 32 that heats the hydrogen gas G introduced into the humidifier 4 through heat exchange with the air discharged from the pump 2. Therefore, with this power generation system 1, it is possible to sufficiently lower the relative humidity of the hydrogen gas G introduced into the humidifier 4 by utilizing not only the heat of the air whose temperature has risen due to the heat generated by the fuel cell cell 10, but also the heat of the air whose temperature has risen due to compression by the pump 2 and the mechanical heat generated by the pump 2 (the air discharged from the pump 2). This ensures that a situation in which there is insufficient heat to adequately humidify the hydrogen gas G can be avoided.

[0084] Furthermore, this power generation system 1 includes a heating section 5b having a spiral tube 41 that heats the hydrogen gas G discharged from the humidifier 4 through heat exchange with the air discharged from the separator 14. Therefore, with this power generation system 1, the relative humidity of the hydrogen gas G introduced into the separator 12 can be reduced by utilizing the heat of the air (air discharged from the separator 14) whose temperature has risen due to the heat generated by the fuel cell cell 10 during power generation, thereby effectively avoiding condensation occurring in the hydrogen flow path 12a and other areas.

[0085] Furthermore, this power generation system 1 includes a heating section 5b having a spiral tube 42 that heats the hydrogen gas G discharged from the humidifier 4 through heat exchange with the air discharged from the pump 2. Therefore, with this power generation system 1, the relative humidity of the hydrogen gas G introduced into the separator 12 can be reduced by utilizing not only the heat of the air whose temperature has risen due to the heat generated by the fuel cell cell 10, but also the heat of the air whose temperature has risen due to compression by the pump 2 and the mechanical heat generated by the pump 2 (air discharged from the pump 2), thereby effectively avoiding condensation occurring in the hydrogen flow path 12a, etc.

[0086] Note that the configuration of the "power generation system" is not limited to the example of the configuration of power generation system 1 described above.

[0087] For example, the explanation described an example in which fresh air is introduced into separators 11 and 14 by sucking air from them using a single pump 2 (a configuration in which one pump is used as both the "first pump" and the "second pump"). However, it is also possible to install the "first pump" and the "second pump" separately, with the "first pump" sucking the "first gas" from the "first separator" and the "third pump" sucking the "third gas" from the "third separator" (not shown). Alternatively, instead of the suction-type pump 2, it is also possible to install a pressure-type pump at the inlet of separator 11 or separator 14 to introduce air into separators 11 and 14 (not shown).

[0088] Furthermore, although the explanation described an example in which the air drawn in from separators 11 and 14 is combined and passed through humidifier 4 (a spiral tube 24 that serves as both the "first heat exchange section" and "heat exchange section A"), the "first heat exchange section" and "heat exchange section A" can also be arranged separately (not shown). Furthermore, although the explanation described an example in which the air drawn in from separators 11 and 14 is combined and passed through heating section 5a (a spiral tube 31 that serves as both the "third heat exchange section" and "heat exchange section C"), the "third heat exchange section" and "heat exchange section C" can also be arranged separately (not shown). Furthermore, although the explanation described an example in which the air drawn in from separators 11 and 14 is combined and passed through the heating section 5b (a spiral tube 41 that serves as both the "fifth heat exchange section" and the "heat exchange section E"), the "fifth heat exchange section" and the "heat exchange section E" can also be arranged separately (not shown).

[0089] Furthermore, although the explanation described an example in which the air drawn in from separators 11 and 14 is combined and passed through humidifier 4 (a spiral tube 25 that serves as both the "second heat exchange section" and "heat exchange section B"), the "second heat exchange section" and "heat exchange section B" can also be arranged separately (not shown). Furthermore, although the explanation described an example in which the air drawn in from separators 11 and 14 is combined and passed through heating section 5a (a spiral tube 32 that serves as both the "fourth heat exchange section" and "heat exchange section D"), the "fourth heat exchange section" and "heat exchange section D" can also be arranged separately (not shown). Furthermore, although the explanation described an example in which the air drawn in from separators 11 and 14 is combined and passed through the heating section 5b (a spiral tube 42 that serves as both the "sixth heat exchange section" and the "heat exchange section F"), the "sixth heat exchange section" and the "heat exchange section F" can also be arranged separately (not shown).

[0090] Furthermore, configurations that do not utilize the thermal energy of the air discharged from separator 11 (not shown), configurations that do not utilize the thermal energy of the air discharged from separator 14 (not shown), and configurations that do not utilize the thermal energy of the air discharged from pump 2 (not shown) can also be adopted. [Explanation of Symbols]

[0091] 1. Power generation system 2 pumps 3 Gas-liquid separation tank 4 Humidifier 4a Water storage tank 5a,5b Heating section 6a~6c, 7a~7c, 8a, 8b control valves 9. Control Unit 10 fuel cell cells 11, 12, 14 Separators 11a Airflow channel 12a Hydrogen channel 13 MEA 14a Air channel a 21 Water storage tank 22 nozzles 23 Spheres 24,25,31,32,41,42 spiral tube 33,43 Insulation Pa1~Pa5, Pb0~Pb4, Pc1~Pc4, Pd0~Pd4, Pe1~Pe3, Pg1~Pg3, Pw1, Pw2 Piping G Hydrogen gas W water X Hydrogen gas supply source

Claims

1. A power generation system comprising a power generation cell configured to generate electricity by reacting the first gas and the second gas via the film electrode assembly, wherein a plurality of flat laminates, each including at least a first separator through which a first gas containing an oxidizing agent passes, a second separator through which a second gas containing hydrogen passes, and a film electrode assembly disposed between the first and second separators, are stacked and integrated, and the first gas and the second gas are reacted via the film electrode assembly, A first suction pump that introduces new first gas into the first separator by sucking the first gas from the first separator, A gas-liquid separation tank for separating the mixture of the first gas and water discharged from the first separator into the first gas and the water, The system comprises a humidifier having a water tank through which the second gas supplied to the second separator can pass, and a humidifier that humidifies the second gas passing through the water tank, The humidifier is configured to store the water separated in the gas-liquid separation tank in the water storage tank, and includes a first heat exchange unit that heats the water in the water storage tank by heat exchange with the first gas discharged from the first separator and separated in the gas-liquid separation tank, and a second heat exchange unit that heats the water in the water storage tank by heat exchange with the first gas discharged from the first suction pump. The first heat exchange unit is configured to heat the water in the water tank by heat exchange with the first gas that passes through the first spiral pipe, which is housed in the water tank so as to be immersed in the water in the water tank. The power generation system is configured such that the second heat exchange unit includes a second spiral pipe housed in the water storage tank so as to be immersed in the water in the water storage tank, and the water in the water storage tank is heated by heat exchange with the first gas that passes through the second spiral pipe.

2. The power generation system according to Claim 1, wherein the humidifier comprises a nozzle capable of discharging the second gas into the water storage tank, and a number of spheres formed in the shape of small balls and housed in the water storage tank so as to generate buoyancy relative to the water stored in the water storage tank, and the second gas discharged from the nozzle is made to float in the water stored in the water storage tank and then passes between the number of spheres before being supplied to the second separator.

3. The power generation system according to claim 1, further comprising a third heat exchange unit that heats the second gas introduced into the humidifier by heat exchange with the first gas discharged from the first separator.

4. The power generation system according to claim 1, further comprising a fourth heat exchange unit that heats the second gas introduced into the humidifier by heat exchange with the first gas discharged from the first suction pump.

5. The power generation system according to claim 1, further comprising a fifth heat exchange unit that heats the second gas discharged from the humidifier by heat exchange with the first gas discharged from the first separator.

6. The power generation system according to claim 1, further comprising a sixth heat exchange unit that heats the second gas discharged from the humidifier by heat exchange with the first gas discharged from the first suction pump.

Images