Power generation unit

Abstract

To provide a power generation unit which can suppress the increase in an installation area even if it is equipped with a load module.SOLUTION: A power generation unit 100 is operated in a parallel state or a parallel-off state with a commercial power supply system 500, and includes: a power generation module 20; an auxiliary machine 30; a unit base 60 on which the power generation module 20 and the auxiliary machine 30 are mounted; a housing 62 which is installed on the unit base 60 so as to surround the power generation module 20 and the auxiliary machine 30; a power conditioner 16 arranged inside the housing 62; a controller 17 arranged inside the housing 62; an autonomous outlet 300 which is arranged inside or outside the housing 62, and supplies a part of generated power of the power generation module 20 to outside, in the parallel-off state with the commercial power supply system 500; and a load module 40 which is arranged outside the housing 62, and consumes a part of the generated power of the power generation module 20 therein, in the parallel-off state with the commercial power supply system 500.SELECTED DRAWING: Figure 3

Description

Technical Field

[0001] The present invention relates to a power generation unit using a fuel cell or the like.

Background Art

[0002] By switching a part of the commercial power purchased by a consumer from a power utility to self-generated power, it is expected to lead to a reduction in carbon dioxide emissions. For example, the primary energy efficiency of thermal power generation using coal or LNG as fuel is about 40%, while the primary energy efficiency of a solid oxide fuel cell (SOFC) that generates power by reforming city gas mainly composed of methane can be expected to be 50% - 65%. Therefore, increasing the proportion of self-generated power can contribute to reducing the environmental load.

[0003] In addition, by realizing a system that can independently maintain power supply when a power outage occurs due to a natural disaster, it is expected that the adverse effects on social life and economic activities can be reduced. For example, a solid oxide fuel cell (SOFC) can generate power independently and supply power to the outside as long as the supply of city gas is not interrupted. In the case of an earthquake, the gas infrastructure may be damaged depending on the scale, but in the case of a typhoon, it can be said that there is almost no impact on the gas infrastructure, so power supply can be continued.

[0004] Patent Documents 1 to 3 disclose a power generation unit (fuel cell unit) that is operated in parallel with a commercial power supply system and supplies power to power demand facilities. It is not allowed to reverse the power flow to the commercial power supply system during the operation of the power generation unit. Therefore, in the power generation units described in Patent Documents 1 and 2, the surplus generated power is consumed by an electric heater or the like.

[0005] In addition, the power generation unit described in Patent Document 3 is disconnected from the commercial power supply system to avoid reverse power flow and switched to independent operation when the commercial power supply system experiences a power outage. When the power generation unit is disconnected, it cannot supply power to the power demand facilities. Therefore, the self-generated power is sent to a self-powered outlet where electrical equipment can be connected to meet the power needs of the consumers.

Prior Art Documents

Patent Documents

[0006]

Patent Document 1

Patent Document 2

Patent Document 3

Summary of the Invention

Problems to be Solved by the Invention

[0007] A general self-powered outlet has multiple plug sockets so that several electrical devices can be used simultaneously. However, the power consumption varies depending on the number of connected electrical devices. Therefore, the independent operation power (output power) of the power generation unit is kept constant, and the excess generated power is consumed by a load module incorporating an electric heater or the like.

[0008] When equipping the power generation unit with a load module, it is desirable to ensure sufficient independent operation power to meet the diverse power needs of consumers. However, increasing the independent operation power inevitably leads to an increase in the size of the load module, resulting in an increase in the installation area of the power generation unit, which is inconvenient.

[0009] The present invention has been made in view of the above problems, and an object thereof is to provide a power generation unit that can suppress an increase in the installation area even when equipped with a load module.

Means for Solving the Problems

[0010] The power generation unit according to the present invention is a power generation unit that operates in a parallel state or a disconnected state with respect to a commercial power supply system, and includes a power generation module operated by an auxiliary machine, a unit base on which the power generation module and the auxiliary machine are mounted, a housing installed on the unit base so as to surround the power generation module and the auxiliary machine, a power conditioner disposed inside the housing for converting the generated power of the power generation module into output power corresponding to the AC power of the commercial power supply system, a controller disposed inside the housing for controlling the power generation module and the auxiliary machine, a self - contained outlet disposed inside or outside the housing for supplying a part of the generated power of the power generation module to the outside when in a disconnected state from the commercial power supply system, and a load module disposed inside the housing for consuming a part of the generated power of the power generation module internally when in a disconnected state from the commercial power supply system.

Advantages of the Invention

[0011] According to the present invention, it is possible to provide a power generation unit capable of suppressing an increase in the installation area even when equipped with a load module.

Brief Description of the Drawings

[0012]

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Embodiments for Carrying Out the Invention

[0013] Hereinafter, each embodiment of the present invention will be described with reference to each drawing.

[0014] 〔First Embodiment〕 <Configuration Outline of Power Generation Unit> First, the configuration outline of the power generation unit according to the first embodiment will be described. FIG. 1 is a schematic diagram showing the configuration of the power generation unit according to the first embodiment. As shown in FIG. 1, the power generation unit 100 is a monogeneration type using a fuel cell, and includes a plurality of cell stacks 1, a reformer 2, a burner 3, an evaporator 4, an air preheater 5, an anode off-gas cooler 6, an anode off-gas condenser 7, a CO oxidizer (carbon monoxide oxidizer) 8, a condensate recovery tank 9, a first raw fuel blower 10, a first air blower 11, a water pump 12, a second raw fuel blower 13, a second air blower 14, a third air blower 15, a power conditioner 16, and a unit controller 17.

[0015] In the example of this embodiment, a total of eight cell stacks 1 are provided, including those not shown in FIG. 1.

[0016] Further, the power generation unit 100 includes lines (pipelines) of a raw fuel line La, a mixed gas line Lb, an anode fuel line Lc, an anode off-gas line Ld, a cathode air line Le, a cathode off-gas line Lf, a combustion gas line Lg, a burner cooling air line Lh, a reformed water line Li, a startup air line Lj, a cooling air line Lk, and a condensate recovery line Lw.

[0017] The anode fuel line Lc includes a first distribution manifold Ma that serves as a main pipe for introducing anode fuel, and the cathode air line Le includes a second distribution manifold Mb that serves as a main pipe for introducing cathode air. These distribution manifolds Ma and Mb have an inlet and a plurality of outlets corresponding to each cell stack 1, and cause the fluid flowing into the inlet to flow out from each outlet.

[0018] The anode off-gas line Ld includes a first collection manifold Mc that serves as a main pipe for discharging anode off-gas, and the cathode off-gas line Lf includes a second collection manifold Md that serves as a main pipe for discharging cathode off-gas. These collection manifolds Mc and Md have a plurality of inlets and outlets corresponding to each cell stack 1, and cause the fluid flowing into each inlet to flow out from the outlet.

[0019] The combustion gas line Lg includes a heat radiation cylinder Za and a combustion gas pipe Zb. The cooling air line Lk includes a cooling pipe Zc and a collection pipe Lk1.

[0020] The raw fuel line La is a pipeline connecting the fuel intake port E1 and the burner 3, and a second raw fuel blower 13 is arranged in this pipeline. The second raw fuel blower 13 is a device that boosts the raw fuel gas Gf (for example, methane-containing gas such as city gas 13A) taken in from the fuel intake port E1 and sends it to the downstream side of the raw fuel line La, and is typically driven during the startup operation of the power generation unit 100.

[0021] The mixed gas line Lb is a pipeline connecting the fuel inlet E2 and the reformer 2. In this pipeline, in order from the upstream side, a first raw fuel blower 10, an evaporator 4, and a first bellows type expansion joint B1 are arranged. The first raw fuel blower 10 is a device that boosts the raw fuel gas Ga taken in from the fuel inlet E2 and sends it to the downstream side of the mixed gas line Lb, and is typically driven during the power generation operation of the power generation unit 100.

[0022] The anode fuel line Lc is a pipeline connecting the reformer 2 and the anode of each cell stack 1. More specifically, the anode fuel line Lc includes, in order from the upstream side, a pipeline connecting the reformer 2 and the inlet of the first distribution manifold Ma, the first distribution manifold Ma, and eight pipelines (the branch pipes of the first distribution manifold Ma) connecting each outlet of the first distribution manifold Ma and the anode of each cell stack 1.

[0023] The anode off-gas line Ld is a pipeline connecting the anode of each cell stack 1 and the burner 3. More specifically, the anode off-gas line Ld includes, in order from the upstream side, eight pipelines (the branch pipes of the first collection manifold Mc) connecting the anode of each cell stack 1 and each inlet of the first collection manifold Mc, the first collection manifold Mc, and a pipeline (hereinafter referred to as "pipeline Ld1") connecting the outlet of the first collection manifold Mc and the burner 3. In the middle of the pipeline Ld1, in order from the upstream side, a second bellows type expansion joint B2, an anode off-gas cooler 6, an anode off-gas condenser 7, and a gas-liquid separation section Sa are arranged.

[0024] The cathode air line Le is a pipeline connecting the air inlet E3 and the cathode of each cell stack 1. More specifically, the cathode air line Le includes, in order from the upstream side, a pipeline (hereinafter referred to as "pipeline Le1") connecting the air inlet E3 and the inlet of the second distribution manifold Mb, the second distribution manifold Mb, and eight pipelines (the branch pipes of the second distribution manifold Mb) connecting each outlet of the second distribution manifold Mb and the cathode of each cell stack 1.

[0025] In the middle of pipeline Le1, in order from the upstream side, a first air blower 11, an anode off-gas cooler 6, an air preheater 5, and a third bellows type expansion joint B3 are arranged. The first air blower 11 is a device that boosts the air Aa taken in from the air intake E3 and sends it to the downstream side of the cathode air line Le, and is typically driven during the power generation operation of the power generation unit 100. Further, in the pipeline Le1, a bypass path Le2 that bypasses the anode off-gas cooler 6 and the air preheater 5 is provided so as to connect the midpoint between the air intake E3 and the anode off-gas cooler 6 and the midpoint between the air preheater 5 and the third bellows type expansion joint B3.

[0026] The cathode off-gas line Lf is a pipeline that connects the cathode of each cell stack 1 and the burner 3. More specifically, the cathode off-gas line Lf has, in order from the upstream side, eight pipelines (branch pipes of the second collection manifold Md) that connect the cathode of each cell stack 1 and the inlets of the second collection manifold Md, the second collection manifold Md, and a pipeline (hereinafter referred to as "pipeline Lf1") that connects the outlet of the second collection manifold Md and the burner 3.

[0027] The combustion gas line Lg is a pipeline that connects the burner 3 and the gas discharge port E6. More specifically, the combustion gas line Lg has, in order from the upstream side, a heat radiation cylinder Za, a pipeline that connects the heat radiation cylinder Za and the combustion gas pipe Zb, the combustion gas pipe Zb, and a pipeline (hereinafter referred to as "pipeline Lg1") that connects the combustion gas pipe Zb and the gas discharge port E6. In the middle of the pipeline Lg1, in order from the upstream side, a fourth bellows type expansion joint B4, an air preheater 5, a CO oxidizer 8, and an evaporator 4 are arranged.

[0028] The burner cooling air line Lh is a pipe connecting the pipe line Le1 and the starting air line Lj, and a flow rate adjusting means (such as an orifice) (not shown) is provided in this pipe line. More specifically described, the burner cooling air line Lh branches at an intermediate point of the pipe line Le1 connecting the first air blower 11 and the anode off-gas cooler 6, and merges into the starting air line Lj on the downstream side of the second air blower 14. It is configured such that a minute flow rate of air Ab flows toward the burner 3 when the first air blower 11 is driven.

[0029] The cooling air line Lk is a pipe connecting the air intake E5 and a predetermined position of the pipe line Lg1 (a position between the evaporator 4 and the gas discharge port E6), and in this pipe line, a third air blower 15 and a cooling pipe Zc are arranged in order from the upstream side. The third air blower 15 is a device that boosts the cooling air Ad taken in from the air intake E5 and sends it to the downstream side of the cooling air line Lk.

[0030] The reformed water line Li is a pipe connecting the condensed water recovery tank 9 and the evaporator 4, and a water pump 12 is arranged in this pipe line. The water pump 12 is a device that sends the condensed water Wb stored in the condensed water recovery tank 9 as reformed water Wa to the downstream side of the reformed water line Li.

[0031] The starting air line Lj is a pipe connecting the air intake E4 and the pipe line Lf1, and a second air blower 14 is arranged in this pipe line. The second air blower 14 is a device that boosts the air Ac taken in from the air intake E4 and sends it to the downstream side of the starting air line Lj, and is typically driven during the startup operation of the power generation unit 100.

[0032] The condensate recovery line Lw is a pipeline that connects the gas-liquid separation section Sa disposed in the middle of the pipeline Ld1 and the condensate recovery tank 9. The gas-liquid separation section Sa is a member that separates the condensate Wb generated in the anode off-gas condenser 7 from the anode off-gas Gd, and the separated condensate Wb flows down in the condensate recovery line Lw. The tip of the condensate recovery line Lw is opened to the gas phase part without being immersed in the aqueous phase part of the condensate recovery tank 9 so that the condensation amount does not increase or decrease under the influence of the water temperature of the stored condensate Wb. Note that the tip of the condensate recovery line Lw is not immersed in the aqueous phase part in order not to change the flow rate of the anode off-gas Gd sent to the burner 3. In particular, this configuration is effective when the anode off-gas Gd after separating the condensate Wb is recycled to the primary side of the cell stack or used for power generation in the subsequent cell stack. For the gas-liquid separation section Sa, for example, a T-shaped pipe in which a straight pipe section is arranged horizontally and a branch pipe section is arranged downward is used. Also, a small-capacity cylindrical container erected vertically can be used as the gas-liquid separation section Sa.

[0033] The cell stack 1 is a power generation body composed of a solid oxide fuel cell (SOFC). The solid oxide fuel cell is a high-temperature operating fuel cell in which the solid electrolyte, anode, and cathode constituting the power generation cell are all ceramics, and a power generation unit in which a predetermined number of power generation cells are integrated via a metal interconnect material (also referred to as a separator material) is called a cell stack. The battery output of the cell stack 1 is supplied after being adjusted by the power conditioner 16.

[0034] The reformer 2 reforms the raw fuel gas Ga using steam, generates a reformed gas Gc, and sends it to the subsequent stage side. The reformer 2 has a catalyst for steam reforming, reacts methane contained in the raw fuel gas Ga with steam, and generates a reformed gas Gc containing carbon monoxide and hydrogen. Although steam reforming is an endothermic reaction, the reformer 2 can stably generate the reformed gas Gc by heat supply from the burner 3.

[0035] The burner 3 burns the inflowing gas to generate heat, and discharges the combustion gas Gg generated by the combustion into the combustion gas line Lg. The evaporator 4 is a device that indirectly heat-exchanges the reformed water Wa and the combustion gas Gg (heat source fluid). By heat-exchanging with the combustion gas Gg, it evaporates the reformed water Wa and at the same time plays a role in heating the raw fuel gas Ga.

[0036] The air preheater 5 and the anode off-gas cooler 6 are both heat exchangers that indirectly heat-exchange a low-temperature fluid and a high-temperature fluid. The air preheater 5 plays a role in preheating the air Aa in the cathode air line Le by heat-exchanging with the combustion gas Gg, and the anode off-gas cooler 6 plays a role in cooling the anode off-gas Gd by heat-exchanging with the air Aa in the cathode air line Le.

[0037] The anode off-gas condenser 7 uses the fan 7a to cool the anode off-gas Gd and condenses the water vapor contained in the anode off-gas Gd. Note that the anode off-gas condenser 7 of this embodiment is an air-cooled heat exchanger, but instead, a water-cooled heat exchanger may be adopted, and thus it may be a cogeneration type power generation unit in which heat recovery is performed.

[0038] The CO oxidizer 8 is a device that brings the harmful carbon monoxide contained in the combustion gas Gg into contact with a catalyst and converts it into harmless carbon dioxide. The CO oxidizer 8 does not operate when the oxidation reaction in the burner 3 is complete, and operates only when the oxidation reaction in the burner 3 is incomplete.

[0039] The condensate recovery tank 9 recovers the condensate Wb discharged from the gas-liquid separation section Sa and makes it reusable as reformed water Wa. In the condensate recovery tank 9, a water level detector Sb and a drain valve Sc are provided to adjust the water level of the stored reformed water Wa within a predetermined range. When the water level detector Sb detects the upper limit water level, the drain valve Sc is opened, while when the water level detector Sb detects the lower limit water level, the drain valve Sc is closed. In this way, the required amount of reformed water Wa is ensured in the condensate recovery tank 9. In addition, in order to prevent the anode off-gas Gd from leaking to the outside during the drainage operation of the reformed water Wa, the drainage position by the drain valve Sc is set near the bottom of the condensate recovery tank 9.

[0040] Also, as shown by the dashed frame in FIG. 1, each cell stack 1, reformer 2, burner 3, each manifold Ma to Md, heat radiation cylinder Za, combustion gas pipe Zb, and cooling pipe Zc are arranged in the first region R1. The first region R1 is maintained at a temperature exceeding 600°C during the power generation operation of the power generation unit 100 and independently maintains the heat balance of heat absorption and heat generation. On the other hand, the evaporator 4, air preheater 5, anode off-gas cooler 6, and CO oxidizer 8 are arranged in the second region R2. The second region R2 is maintained at a temperature lower than that of the first region R1 and higher than room temperature during the power generation operation of the power generation unit 100. The first region R1 and the second region R2 are each surrounded by a heat insulation box, and the power generation module 20 is formed by integrating the two heat insulation boxes. The anode off-gas condenser 7, condenser fan 7a, condensate recovery tank 9, each blower 10, 11, 13, 14, 15, water pump 12, power conditioner 16, and unit controller 17 are arranged outside the power generation module 20 (room temperature region). In addition, the above-described bellows type expansion pipe joints B1 to B4 are used to absorb the expansion and contraction of the pipes caused by the temperature change between the cold state and the operation state.

[0041] Figure 2 is a schematic diagram showing the configuration of the power conditioner 16 according to the present embodiment, and shows the internal configuration of the power conditioner 16 and the connection state to peripheral devices. The power generation module 20 is configured to include elements such as the cell stack 1 as described above. Further, the auxiliary machine 30 for operating the power generation module 20 includes components such as the raw fuel blowers 10 and 13, the air blowers 11, 14, and 15, the water pump 12, and the fan 7a of the anode off-gas condenser 7.

[0042] The power conditioner 16 converts the generated power of the power generation module 20 into output power corresponding to the AC power of the commercial power supply system 500. The power conditioner 16 includes DC / DC converters 16a and 16b, a smoothing capacitor 16c, a grid-connected inverter 16d, switches 16e and 16f, and control circuits 16g and 16h.

[0043] The DC / DC converter 16a boosts and converts the DC power from the power generation module 20 (boosting circuit). The smoothing capacitor 16c smoothes the output power of the DC / DC converter 16a. The grid-connected inverter 16d converts the output power of the DC / DC converter 16a into AC power equivalent to the commercial power supply system.

[0044] The output side of the grid-connected inverter 16d is electrically connected to, for example, a switchboard 610 for receiving commercial power installed in a building. The grid-connected inverter 16d and the switchboard 610 can be switched between a parallel state and a disconnected state via the switch 16e. The switchboard 610 is electrically connected to the commercial power supply system 500 and the power demand facility 600. The power demand facility 600 includes a plurality of sub-switchboards, and each sub-switchboard is electrically connected to load devices such as lighting fixtures, power units, or outlets used in the building.

[0045] In addition, the grid-connected inverter 16d is electrically connected to the independent power strip 300. The grid-connected inverter 16d and the independent power strip 300 can be switched between a connected state and a disconnected state via the switch 16f. The independent power strip 300 is composed of a plurality of outlets into which the power plugs of various power-consuming devices can be inserted.

[0046] The DC / DC converter 16b and the control circuit 16g function as a driving power supply unit that supplies driving power to the auxiliary machine 30. The DC / DC converter 16b adjusts the DC voltage boosted by the DC / DC converter 16a to a DC voltage suitable for driving the auxiliary machine 30. The control circuit 16g supplies the DC voltage adjusted by the DC / DC converter 16b to the auxiliary machines 30 to appropriately drive the auxiliary machine 30. Note that the above-mentioned auxiliary machine 30 is driven using commercial power during the startup operation and shutdown operation of the power generation unit 100, and is driven using the generated power during the power generation operation of the power generation unit 100.

[0047] The DC / DC converter 16a and the control circuit 16h function as an operating power supply unit that supplies operating power to the first load module 40 and the second load module 50. The first load module 40 is configured to include an electric heater 41 and a radiator fan 42. Similarly, the second load module 50 is configured to include an electric heater 51 and a radiator fan 52. Each load module 40, 50, in the independent operation mode of the power generation unit 100, causes the electric heaters 41, 52 to generate heat to consume the surplus generated power of the cell stack 1, and the radiator fans 42, 52 send air flows to the electric heaters 41, 51 respectively to promote heat dissipation.

[0048] The unit controller 17 controls the operation of the power generation unit 100 according to a control program created and stored in advance. The unit controller 17 is constituted by a programmable logic controller (PLC). The PLC has an arithmetic unit, a storage unit, an input unit, an output unit, and a power supply unit, and executes required arithmetic operations and sequence control using a processing program created and stored in advance. A communication unit 17a for communicating with the outside of the power generation unit 100 is provided in the unit controller 17.

[0049] <Overview of the operation of the power generation unit> Next, an overview of the operation of the power generation unit 100 will be described with reference to FIG. 1. The raw fuel gas Ga supplied into the mixed gas line Lb from the fuel inlet E2 is sent to the subsequent stage by the action of the first raw fuel blower 10. In parallel with the supply of the raw fuel gas Ga, the reformed water Wa supplied into the reformed water line Li from the condensed water recovery tank 9 has its water volume adjusted by the water pump 12 and flows into the mixed gas line Lb.

[0050] The reformed water Wa flows into the evaporator 4 together with the raw fuel gas Ga in the mixed gas line Lb, and is heated by heat exchange in the evaporator 4 to become water vapor (superheated steam). The water vapor is mixed with the heated raw fuel gas Ga and flows into the reformer 2 as the mixed gas Gb.

[0051] The reformer 2 reforms the raw fuel gas Ga using the water vapor in the mixed gas Gb, generates a reformed gas Gc, and sends it to the subsequent stage. The reformed gas Gc sent out from the reformer 2 is distributed to the anodes of the respective cell stacks 1 through the anode fuel line Lc.

[0052] On the other hand, in parallel with the supply of the above-described raw fuel gas Ga, air Aa is supplied from the air inlet E3 into the cathode air line Le. The air Aa in the cathode air line Le is sent to the downstream side by the action of the first air blower 11. This air Aa is heated by heat exchange in the anode off-gas cooler 6 and further heated by heat exchange in the air preheater 5, and then distributed to the cathodes of the respective cell stacks 1. Note that, for temperature adjustment of the air Aa, etc., it is also possible to allow a part of the air Aa, i.e., air Aa1, to flow into the cathodes of the respective cell stacks 1 via the bypass path Le2.

[0053] Furthermore, in synchronization with the supply of the air Aa to the cathode, air Ab is supplied into the burner cooling air line Lh. The air Ab in the burner cooling air line Lh is sent to the burner 3 by the action of the first air blower 11. This air Ab acts as a coolant for reducing the combustion temperature of the burner 3.

[0054] Each cell stack 1 generates electricity using the reformed gas Gc flowing into the anode and the air Aa flowing into the cathode. When current sweeping is performed by the power conditioner 16 in a state where the reformed gas Gc and the air Aa are supplied to the cell stack 1, power generation (electrochemical reaction between the reformed gas and oxygen) of the cell stack 1 is started. During the power generation operation of the cell stack 1, the anode off-gas Gd is discharged from the anode to the anode off-gas line Ld, and the cathode off-gas Ge is discharged from the cathode to the cathode off-gas line Lf. The anode off-gas Gd contains the reformed gas that was unreacted at the anode, and the cathode off-gas Ge contains the oxygen that was unreacted at the cathode.

[0055] The anode off-gas Gd discharged from each cell stack 1 to the anode off-gas line Ld is collected in the first collection manifold Mc, then cooled by heat exchange in the anode off-gas cooler 6, and flows into the anode off-gas condenser 7. In the anode off-gas condenser 7, the anode off-gas Gd is cooled to below the dew point temperature, and the water vapor contained in the anode off-gas Gd condenses.

[0056] The anode off-gas Gd that has passed through the anode off-gas condenser 7 is sent to the gas-liquid separation section Sa for gas-liquid separation, and the condensed water Wb is recovered in the condensed water recovery tank 9. The condensed water Wb recovered in the condensed water recovery tank 9 is reused as the reformed water Wa as described above. Recovering the water generated by the electrochemical reaction between the reformed gas Gc and oxygen and repeatedly using it in the steam reforming reaction is called water self-sufficiency. Note that the non-condensed portion in the anode off-gas Gd (the anode off-gas Gd after gas-liquid separation) is sent to the burner 3.

[0057] The cathode off-gas Ge discharged from each cell stack 1 to the cathode off-gas line Lf is collected in the second collection manifold Md, and then mixed with the air Ab that has flowed in through the burner cooling air line Lh in the pipeline Lf1 and sent to the burner 3. Also, to the burner 3, according to the operating state of the power generation unit 100, the raw fuel gas Gf supplied from the fuel inlet E1 is sent through the raw fuel line La, and the air Ac supplied from the air inlet E4 is sent through the starting air line Lj.

[0058] The burner 3 has the first burner gas Gx which is the raw fuel gas Gf and / or the anode off-gas Gd, and the second burner gas Gy which is the air Ac and / or the cathode off-gas Ge flowing in, and burns these to generate heat. That is, the first burner gas Gx is a mixed gas of the raw fuel gas Gf and the anode off-gas Gd, or in a state of either the raw fuel gas Gf or the anode off-gas Gd, and which state it is in can change depending on the operating state of the power generation unit 100 and the like. Also, the second burner gas Gy is a mixed gas of the air Ac and the cathode off-gas Ge, or in a state of either the air Ac or the cathode off-gas Ge, and which state it is in can change depending on the operating state of the power generation unit and the like. That is, according to the startup operation, power generation operation (full load operation or partial load operation), shutdown operation, etc. of the power generation unit 100, the supply gas to the burner 3 changes its state appropriately.

[0059] Note that the raw fuel gas Gf is a type of hydrocarbon-containing gas. On the other hand, the air Ac is a type of oxidant-containing gas. During the combustion operation of the burner 3, air Ab is continuously supplied from the burner cooling air line Lh, and the combustion temperature is adjusted.

[0060] The combustion gas Gg generated by the combustion in the burner 3 is sent to the combustion gas line Lg, passes through the heat radiation cylinder Za, the combustion gas pipe Zb, the air preheater 5, the CO oxidizer 8, and the evaporator 4 in sequence, and is discharged from the gas outlet E6 to the outside of the power generation module 20. The heat radiation cylinder Za and the combustion gas pipe Zb are arranged so that the reformer 2 can be effectively heated using the combustion gas Gg. Also, the combustion gas Gg in the combustion gas line Lg is utilized for heat exchange when passing through the air preheater 5 and the evaporator 4, and when carbon monoxide is contained, the carbon monoxide is converted to carbon dioxide when passing through the CO oxidizer 8.

[0061] Also, the cooling air Ad supplied from the air inlet E5 to the cooling air line Lk plays a role in cooling the inside of the power generation module 20 when passing through the cooling pipe Zc. As will be described later, the cooling pipe Zc is installed in the vicinity of the cell stack 1, and the cell stack 1 can be effectively cooled by the cooling air Ad. Then, the cooling air Ad finally passes through the collecting pipe Lk1 and is discharged from the gas outlet E6 to the outside of the power generation module 20 together with the combustion gas Gg.

[0062] Also, in the power generation unit 100, the amount of heat (temperature) inside the power generation module 20 is controlled by adjusting the flow rate of the cooling air Ad introduced into the cooling pipe Zc. As an example, when the discharge temperature of the cathode off-gas Ge flowing out from the cell stack 1 exceeds the upper limit temperature, the unit controller 17 drives the third air blower 15, and controls the rotation speed of the third air blower 15 so that the discharge temperature of the cathode off-gas Ge becomes the target temperature (a temperature lower than the upper limit temperature by a predetermined temperature). The greater the rotation speed of the third air blower 15 increases, the greater the flow rate of the cooling air Ad introduced into the cooling pipe Zc increases. Also, when the rotation speed below the lower limit value continues for a predetermined time, the unit controller 17 stops the third air blower 15.

[0063] In addition, the cooling pipe Zc installed near the cell stack 1 can also be used to heat up the cell stack 1 during the startup operation of the power generation unit 100. Specifically, in the startup operation of the power generation unit 100, first, the second raw fuel blower 13 and the second air blower 14 are driven to burn the burner 3. The combustion gas Gg generated by this combustion flows through the heat radiation cylinder Za and the combustion gas pipe Zb, and heats up the cold reformer 2 from the outside by radiative heat transfer to increase its temperature. Further, the combustion gas Gg becomes the heat source of the evaporator 4 and generates water vapor from the reforming water Wa. This water vapor flows through the cold reformer 2 and the cell stack 1 in sequence, and heats up these devices from the inside by heat conduction to increase their temperature. If there is residual heat in the combustion gas Gg discharged from the evaporator 4, the combustion gas Gg is made to flow from the pipeline Lg1 to the collection pipe Lk1. As a result, the combustion gas Gg flows through the cooling pipe Zc, so that the cold cell stack 1 can be heated from the outside by radiative heat transfer to increase its temperature.

[0064] In the power generation operation of the power generation unit 100, the heat balance of the heat generation due to the electrochemical reaction between the reformed gas Gc and oxygen in the cell stack 1, the heat generation due to the combustion reaction between the anode off-gas Gd and the cathode off-gas Ge in the burner 3, and the endothermic heat of the steam reforming reaction between the raw fuel gas Ga and water vapor (reforming water Wa) in the reformer 2 is called "thermal self-sufficiency". Also, the water (reforming water Wa) generated by the electrochemical reaction between the reformed gas Gc and oxygen is recovered and repeatedly used for the steam reforming reaction, which is called "water self-sufficiency".

[0065] In the power generation operation of the power generation unit 100, the output power of the grid-connected inverter 16d is equal to the value obtained by subtracting the total power losses due to the operation of the auxiliary machine 30, the power losses due to the operation of the power conditioner 16, and the power losses due to the operation of the load module 40. The load module 40 operates in the self-powered operation mode described later.

[0066] When the power generation unit 100 is operated at full load with the rated output power, the unit controller 17 sets the sweep current value for the cell stack 1 to the rated current value and supplies the corresponding amount of the raw fuel gas Ga. When the power generation unit 100 is operated at a partial load below the rated output power and equal to or higher than the minimum output power, the unit controller 17 sets the sweep current value for the cell stack 1 to a range lower than the rated current value and equal to or higher than the lower limit current value, and supplies the corresponding amount of the raw fuel gas Ga. When the power generation unit 100 is put on standby with zero output power, the unit controller 17 sets the sweep current value for the cell stack 1 to the value corresponding to the operating power of the auxiliary machine 30, and supplies the minimum amount of the raw fuel gas Ga while keeping the power generation module 20 warm. Note that the state in which the power generation unit 100 is put on standby with zero output power is referred to as "hot standby".

[0067] The power generation operation of the power generation unit 100 includes a grid-connected operation mode and an islanded operation mode. In the grid-connected operation mode, as shown in FIG. 2, the switch 16e is controlled to be in the on state and the switch 16f is controlled to be in the off state. Thereby, the power generation unit 100 is operated in parallel with the commercial power supply system 500. In the islanded operation mode, conversely to FIG. 2, the switch 16e is controlled to be in the off state and the switch 16f is controlled to be in the on state. Thereby, the power generation unit 100 is operated in a disconnected state from the commercial power supply system 500.

[0068] The unit controller 17 constantly monitors the presence or absence of a power outage in the commercial power supply system 500, and when a power outage is detected, shifts the power generation unit 100 from the grid-connected operation mode to the islanded operation mode. In the islanded operation mode, when an electrical device is connected to the outlet 300, it is possible to supply the output power of the grid-connected inverter 16d as the islanded operation power to the electrical device. That is, in the disconnected state, a part of the generated power of the power generation module 20 is supplied to the electrical device via the outlet 300. When the commercial power supply system 500 resumes power supply from a power outage, the unit controller 17 shifts the power generation unit 100 from the islanded operation mode to the grid-connected operation mode.

[0069] When the supply amount of the self-driving power exceeds the consumption amount in the self-driving mode, the power generation unit 100 causes the first load module 40 or the second load module 50 to consume the surplus of the self-driving power (that is, a part of the generated power of the power generation module 20). The adjustment of the power consumption amount of the load module 40 can be realized by adjusting the calorific value of the electric heater 41 (for example, adjusting the number of electric heaters to be energized, or adjusting the on / off duty ratio of the energization), and the same applies to the second load module 50.

[0070] <Operation as an output adjuster> As described above, the power generation unit 100 can operate at the rated output power under full load, operate at a partial load below the rated output power and above the minimum output power, or operate in hot standby with the output power being zero. That is, the power generation unit 100 can be operated as an output adjuster that operates in the range below the rated output power and above the minimum output power. In addition, since the power generation module 20 in the present embodiment includes an SOFC cell stack, the minimum output power in the partial load operation is set based on the minimum fuel supply amount that can maintain the thermal self-sufficiency of the power generation module 20 and the minimum fuel utilization rate that can maintain the water self-sufficiency of the power generation module 20.

[0071] The maximum output power of the power generation unit 100 in the linked operation mode is equivalent to the rated output power (6 kW). Also, the minimum output power of the power generation unit 100 in the linked operation mode is set as the lower limit value at which, in addition to achieving both thermal self-sufficiency and water self-sufficiency, the decrease in the power generation efficiency during partial load operation does not occur compared to the power generation efficiency during full load operation. The minimum output power in this case is, for example, equivalent to 50% (3 kW) of the rated output power (6 kW). If output adjustment below the minimum output power is required, it will shift to hot standby.

[0072] The maximum output power of the power generation unit 100 in the self-operating mode is determined in consideration of the aging deterioration of the cell stack 1. The maximum output power in this case is equivalent to, for example, 83% (5 kW) of the rated output power (6 kW). Also, the minimum output power of the power generation unit 100 in the self-operating mode is set as the lower limit value that allows for a decrease in the power generation efficiency during partial load operation compared to that during full load operation, in addition to achieving both heat self-sufficiency and water self-sufficiency. The minimum output power in this case is equivalent to, for example, 25% (1.5 kW) of the rated output power (6 kW). Note that when the power generation capacity of the cell stack 1 decreases due to aging deterioration, the rated output power cannot be ensured in the grid-connected operation mode. However, since the decrease in output power can be compensated by increasing the purchased power, there is no problem in the system operation.

[0073] The output adjuster adjusts the output power from the power conditioner 16 by performing an operation of increasing or decreasing the output current from the grid-connected inverter 16d. The unit controller 17 increases the sweep current value for the cell stack 1 in parallel with the increase in the output current and increases the supply amount of the raw fuel gas Ga. Also, the unit controller 17 decreases the sweep current value for the cell stack 1 in parallel with the decrease in the output current and decreases the supply amount of the raw fuel gas Ga. Thereby, the power generation power of the power generation module 20 increases or decreases as the output current increases or decreases.

[0074] <Basic Configuration of the Load Module> Figures 3 and 4 are perspective views showing the appearance of the power generation unit 100. As shown in Figures 3 and 4, as a configuration on the product, the power generation unit 100 includes a unit base 60 on which the above-described power generation module 20 and auxiliary equipment 30 are placed, and a box-shaped housing 62 installed on the unit base 60 so as to surround these power generation module 20 and auxiliary equipment 30.

[0075] Although not shown in the figure, inside the front side of the housing 62, a power conditioner 16 is arranged at the lower stage and a unit controller 17 is arranged at the upper stage. Inside the rear side of the housing 62, a first load module 40 is arranged at the position indicated by the dashed line. On the upper surface panel (top plate) 65 of the housing 62, a second load module 50 is placed. Further, on the front panel of the housing 62, a socket unit 400 having a plurality of self-standing sockets 300 (to be described later) is provided.

[0076] After shifting to the self-operation mode, the power generation unit 100 can adjust the output within the range of the minimum output power (25% output) to the maximum output power (83% output), and from the socket unit 400, it is possible to take out the self-generated power selected from within this range as the maximum value.

[0077] The first load module 40 is standard equipment for the power generation unit 100. The first load module 40 includes an electric heater 41 having at least the power consumption corresponding to the minimum output power (25% output) of the power generation unit 100 in the self-operation mode.

[0078] The second load module 50 can be selectively added according to the power needs of the customer. The second load module 50 includes an electric heater 51 having at least the power consumption corresponding to the value obtained by subtracting the minimum output power from the maximum output power of the power generation unit 100 (58% output) in the self-operation mode.

[0079] In a specific design example, assuming the rated output power of the power generation unit 100 is 6 kW, the number of heaters etc. of the electric heater 41 of the first load module 40 is designed so that the maximum power consumption becomes 1.5 kW or more, and the power consumption is adjustable within the range of 0 to 1.5 kW. The number of heaters etc. of the electric heater 51 of the second load module 50 is designed so that the maximum power consumption becomes 3.5 kW or more, and the power consumption is adjustable within the range of 0 to 3.5 kW. That is, when using the two load modules 40 and 50, it is possible to design the power consumption to be adjustable within the range of 0 to 5 kW.

[0080] <Detailed Configuration of the First Load Module> Figures 5 and 6 are perspective views showing the internal structure of the first load module 40. Figure 5 shows the state of the first load module 40 as viewed from the left side at the rear of the unit, and Figure 6 shows the state of the first load module 40 as viewed from the right side at the front of the unit.

[0081] The first load module 40 includes a plurality of electric heaters 41 (hereinafter referred to as the "electric heater group 41"), a radiator fan 42, and a heater case 43. The heater case 43 is a hollow rectangular parallelepiped without a top plate and is arranged such that its longitudinal direction is the left - right direction. The electric heater group 41 is housed in the internal space through the upper opening of the heater case 43 and is attached using a support so that the axial direction of each heater is the left - right direction. Each heater is arranged in a state of being spaced apart from each other and from the inner wall of the heater case 43. The heater case 43 has a ventilation port 44 formed in the left side plate and an exhaust port 45 formed on the right side of the bottom plate.

[0082] The radiator fan 42 is attached to the ventilation port 44 of the heater case 43 using a mounting plate. The radiator fan 42 generates an air flow that contacts the electric heater group 41 from the ventilation port 44 toward the exhaust port 45. The air flow sent from the radiator fan 42 flows along the axial direction of each heater over the heater surface, thereby promoting heat dissipation from the heater surface.

[0083] Also, the heater case 43 is arranged inside a mixing box 70 with a larger size. Specifically, the mixing box 70 is sized to be more than twice the size of the heater case 43, and the heater case 43 is attached so as to close the upper opening of the heater case 43 on the lower surface of the top plate of the mixing box 70. A gap 71 is provided between the inner wall of the rear side plate of the mixing box 70 and the outer wall of the rear side plate of the heater case 43.

[0084] Below the lower side of the rear plate of the mixing box 70, a box exhaust port 72 communicating with the exhaust port 45 of the heater case 43 is formed. This box exhaust port 72 communicates with a unit exhaust port 64 (see FIG. 4) formed in the rear panel of the housing 62.

[0085] The heat dissipation fan 42 also serves as a ventilation fan inside the housing 62 that is driven during the power generation operation of the power generation unit 100. When the heat dissipation fan 42 is driven, an air flow passing through the internal space of the housing 62 is generated from the unit ventilation port 63 (see FIG. 3) formed in the front panel of the housing 62 toward the unit exhaust port 64.

[0086] Inside the mixing box 70, a partition wall 73 is provided at the central portion in the front-rear direction, arranged parallel to the front plate and the rear plate. The lower end portion of the partition wall 73 is in contact with the bottom plate of the mixing box 70, and the upper end portion of the partition wall 73 is in contact with the bottom plate of the heater case 43. Also, the left end portion of the partition wall 73 is in contact with the left side plate of the heater case 43, and the right end portion of the partition wall 73 is located in front of the exhaust port 45.

[0087] On the bottom plate of the mixing box 70, a gas inflow port 74 is provided on the front side of the partition wall 73. The gas inflow port 74 corresponds to the gas discharge port E6 in FIG. 1, and is configured to allow the exhaust gas in which the combustion gas Gg generated by the burner 3 and the cooling air Ad that has passed through the cooling pipe Zc (cooling body) are merged to flow into the mixing box 70. Since this exhaust gas is pressurized by a blower before generation and is higher than the atmospheric pressure, it passes between the right end portion of the partition wall 73 and the right side plate of the mixing box 70, and flows out toward the unit exhaust port 64 via the box exhaust port 72. Note that the burner 3 and the cooling pipe Zc (the third air blower 15) are devices belonging to the auxiliary equipment for operating the power generation module 20.

[0088] During the operation of the heat dissipation fan 42 which also serves as a ventilation fan, the air flow passes through the unit ventilation port 63, the ventilation port 44, the surface of the electric heater group 41, and the exhaust port 45 in this order. The air flow flowing out from the exhaust port 45 is mixed with the exhaust gas flow flowing into the mixing box 70 from the gas inflow port 74, and is discharged into the atmosphere from the unit exhaust port 64. The combustion gas Gg generated by the burner 3 is diluted by the cooling air Ad when the third air blower 15 is operating, but is also diluted by the air flow after the housing ventilation even when the third air blower 15 is not operating. Therefore, even if the combustion gas Gg contains combustible hydrogen or toxic carbon monoxide due to incomplete combustion of the burner 3 or a decrease in the catalytic activity of the CO oxidizer 8, it can be discharged into the atmosphere after being made safe for the environment and the human body.

[0089] Also, when the electric heater group 41 is energized during the operation of the heat dissipation fan 42, heat dissipation is promoted while the surface of the heater is cooled by the air flow after the housing ventilation. Since the heat dissipation fan 42 is always driven during the power generation operation of the power generation unit 100, its power consumption can be included in the second power loss Q2 of the auxiliary machine 30 described later, and its value can also be regarded as constant.

[0090] <Detailed Configuration of the Second Load Module> FIG. 7 is a perspective view showing the appearance of the second load module 50, and FIG. 8 is a perspective view showing the internal structure of the second load module 50. Both FIG. 7 and FIG. 8 show the second load module 50 as seen from the front left side of the unit.

[0091] The second load module 50 includes a plurality of electric heaters 51 (hereinafter referred to as the "electric heater group 51"), a radiator fan 52, and a heater case 53. The heater case 53 is a hollow rectangular parallelepiped without a front side plate and a rear side plate, and is arranged such that the longitudinal direction is the front-rear direction. The electric heater group 51 is housed in the internal space from the front and rear openings of the heater case 53, and is attached using a support tool such that the axial direction of each heater is the front-rear direction. Each heater is arranged in a state of being separated from each other and separated from the inner wall of the heater case 53. The heater case 53 has a front opening serving as a ventilation port 54 and a rear opening serving as an exhaust port 55.

[0092] The radiator fan 52 is attached to the ventilation port 54 of the heater case 53 using a mounting plate. The radiator fan 52 generates an air flow that contacts the electric heater group 51 from the ventilation port 54 toward the exhaust port 55. The air flow sent from the radiator fan 52 flows along the axial direction of each heater over the heater surface, thereby promoting heat dissipation from the heater surface.

[0093] Also, the heater case 53 is arranged inside an outer box 56 that is larger in size. Specifically, the outer box 56 is one size larger than the heater case 53, and the length in the longitudinal direction is about 1.5 times. The heater case 53 is arranged at the central portion in the longitudinal direction of the outer box 56. The outer box 56 has a ventilation port 57 in the front portion and an exhaust port 58 in the rear portion, and a grille is attached to each of them. Further, an exhaust cover 59 is provided facing the exhaust port 58, and the air flow discharged from the exhaust port 58 is dispersed vertically.

[0094] The second load module 50 is placed on the upper surface panel (top plate) 65 of the housing 62 using six mounting tools so as to float the outer box 56 (see FIG. 3). Since the outer box 56 and the upper surface panel 65 are separated, even when the number of the heater group 51 is increased, the heat dissipation effect from the surface of the outer box 56 to the atmosphere can be expected.

[0095] During the operation of the heat dissipation fan 52, the air flow passes through the ventilation port 57, the ventilation port 54, the surface of the electric heater group 51, the exhaust port 55, and the exhaust port 58 in this order. Also, when the electric heater group 51 is energized during the operation of the heat dissipation fan 52, heat dissipation is promoted while the surface of the heater is cooled by the continuous air flow.

[0096] <Configuration of the self - contained socket> Figure 9 is an enlarged view of the socket unit 400. As shown in Figure 9, the socket unit 400 includes a panel 401, a power lamp 402, an information display section 403, and three self - contained sockets 300a to 300c. The surface of the panel 401 that is exposed forward is formed in a flat shape, and this surface is provided so as to be parallel to the outer surface of the front panel of the housing 62. On the surface of the panel 401, three self - contained sockets 300 are arranged closer to the right side, and near the left side thereof, the power lamp 402 and the information display section 403 are arranged.

[0097] The self - contained socket 300 has an insertion port exposed forward, and it is possible to insert the power plugs of various power - using devices from the front. When a power plug is inserted into this insertion port, the power - using device is connected to the self - contained socket 300. In the example shown in Figure 4, three self - contained sockets 300a, 300b, and 300c are provided, but the number of self - contained sockets 300 is not limited to this.

[0098] The power lamp 402 lights up when it is possible to supply self - operating power when a power - using device is connected to the self - contained socket 300 (when the switch 16f is in the on state), and it is possible to visually recognize whether it is in the lit state or the off state from the front. Thereby, the consumer can instantaneously determine whether the self - contained socket 300 is available at the present time.

[0099] The information display unit 403 displays information corresponding to the power consumption of the self-operating power of the electrical equipment connected to the self-powered outlet 300. The information display unit 403 in the example shown in FIG. 5 is configured as a 7-segment display capable of displaying multiple-digit numbers, and the displayed numbers are visible from the front. Since the display of the information display unit 403 is arranged close to the insertion port of the self-powered outlet 300, a consumer in front of the insertion port (especially a consumer who intends to use the self-powered outlet 300) can easily view the display of the display.

[0100] The available power of the self-powered outlet 300 can be set within a range equal to or greater than the minimum output power in the self-operating mode and equal to or less than the rated output power in the grid-connected operation mode based on the equipment information of the first load module 40 and the second load module 50.

[0101] As described above, the first load module 40 includes an electric heater 41 with a power consumption (1.5 kW) corresponding to the minimum output power (25% output) in the self-operating mode. In the case where the second load module 50 is not selected, all of the minimum output power can be consumed by the first load module 40 when no electrical equipment is connected to the self-powered outlet 300. That is, in a state where the first load module 40 is not operated, all of the minimum output power (1.5 kW) can be taken out from the self-powered outlet 300. That is, when only the first load module 40 is standardly equipped, the available power of the self-powered outlet 300 can be set to correspond to the minimum output power (1.5 kW).

[0102] Further, the second load module 50 is provided with an electric heater 51 having a power consumption (3.5 kW) corresponding to 58% of the maximum output power in the self-operating mode. In the case of selecting the equipment of the second load module 50, when no power-consuming device is connected to the self-contained outlet 300, all of the maximum output power can be consumed by the first load module 40 and the second load module 50. That is, when the two load modules 40 and 50 are not operated, all of the maximum output power (5 kW) can be taken out from the self-contained outlet 300. That is, when the second load module 50 is additionally equipped, the power supplyable by the self-contained outlet 300 can be set to correspond to the maximum output power (5 kW).

[0103] 〔Second Embodiment〕 In the first embodiment, the second load module 50 is placed on the upper surface panel 65 of the housing 62, but in the second embodiment, the second load module 50 is housed inside the upper surface panel 65 of the housing 62. FIG. 10 is an exploded perspective view of the top plate portion of the power generation unit 100. FIG. 11 is a schematic diagram showing the flow of air in the second load module 50. FIG. 10 shows the state of the second load module 50 viewed from the front right side of the unit.

[0104] In the present embodiment, the second load module 50 is disposed inside the upper surface panel 65 constituting the housing 62. More specifically, the second load module 50 is disposed at the upper part inside the housing 62, and the upper surface panel 65 is covered so as to cover the second load module 50. The upper surface panel 65 has side plates protruding vertically downward from the four sides, and by positioning these side plates outside the side surface panels of the housing 62, intrusion of rainwater and the like into the housing 62 is prevented.

[0105] The load module 50 includes an electric heater group 51, a radiation fan 52, and a support plate 53a. The support plate 53a is formed in a three-dimensional shape by vertically bending the long side portion of a rectangular plate placed in the horizontal direction, and a locking portion 53b that projects horizontally is provided at the upper end of the bent portion. The electric heater group 51 is housed inside the support plate 53a and is attached using a support so that the axial direction of each heater is in the left-right direction. Each heater is arranged in a state of being separated from each other and separated from the inner wall of the support plate 53a. The support plate 53a has a ventilation port 54 formed on the plate surface at the front end and an exhaust port 55 at the opening at the rear end. The support plate 53a supporting the electric heater group 51 is arranged at the upper part inside the housing 62 by hooking the locking portion 53b on the upper ends of the left and right side panels constituting the housing 62.

[0106] The radiation fan 52 is attached to the ventilation port 54 formed in the support plate 53a. The radiation fan 52 generates an air flow that contacts the electric heater group 51 from the ventilation port 54 toward the exhaust port 55. The air flow sent from the radiation fan 52 flows along the axial direction of each heater over the heater surface, thereby promoting heat dissipation from the heater surface.

[0107] By the way, inside the power generation unit 100, a protection case 80 for housing the unit controller 17 is arranged at the upper front position indicated by the dashed line in FIG. 10. The protection case 80 is a hollow rectangular parallelepiped without a top plate and a bottom plate, and is arranged so that the longitudinal direction is in the vertical direction. Equipment such as the unit controller 17 and the terminal block is attached to the inner wall of the rear side plate of the protection case 80. The lower end opening of the protection case 80 serves as a ventilation port 81 for taking in an air flow for cooling the controller, and the upper end opening serves as an exhaust port 82 for the air flow after cooling.

[0108] The heat dissipation fan 52 also serves as a cooling fan for the power generation module 20 and the auxiliary machine 30. When the heat dissipation fan 52 is driven, an air flow that contacts the power generation module 20 and the auxiliary machine 30 is generated from the unit vent 63 (see FIG. 3) toward the unit exhaust port 64 (see FIG. 4).

[0109] Also, during the driving of the heat dissipation fan 52, as shown in FIG. 11, the air flow flows in the order of the vent 81, the exhaust port 82, the vent 54, the surface of the electric heater group 51, and the exhaust port 55. The air flow flowing out from the exhaust port 55 flows through the gap 71 between the mixing box 70 and the heater case 43, and then is discharged from the box exhaust port 72 while being mixed with the exhaust gas flow flowing into the mixing box 70 from the gas inflow port 74. Further, when the electric heater group 51 is energized during the driving of the heat dissipation fan 52, heat dissipation is promoted while the surface of the heater is cooled by the continuous air flow.

[0110] 〔Third Embodiment〕 In the first embodiment, the second load module 50 is configured to be placed on the upper surface panel 65 of the housing 62, but in the third embodiment, the second load module 50 is configured to be attached to the outer surface of the housing 62. FIG. 12 is a perspective view showing the appearance of the second load module 50 attached to the power generation unit 100. FIG. 13 is a perspective view showing the internal structure of the second load module 50. FIGS. 12 and 13 are both views of the second load module 50 as seen from the left side at the rear of the unit.

[0111] <I In the present embodiment, the second load module 50 is attached to the rear surface of the housing 62 of the power generation unit 100. Specifically, as shown in FIG. 12, it is equipped on the left side of the rear panel at a position below the unit exhaust port 64.

[0112] The second load module 50 includes an electric heater group 51, a radiator fan 52, and a heater case 53. The heater case 53 is a hollow rectangular parallelepiped without a top plate and a bottom plate, and is arranged such that its longitudinal direction is in the vertical direction. The electric heater group 51 is accommodated in the internal space through the upper and lower openings of the heater case 53, and is attached using a support so that the axial direction of each heater is in the vertical direction. Each heater is arranged in a state of being separated from each other and from the inner wall of the heater case 53, and has a two-stage configuration in the vertical direction. The lower opening of the heater case 53 serves as a ventilation port 54, and the upper opening serves as an exhaust port 55. A waterproof cover 53c for preventing rainwater from entering the heater case 53 is provided above the upper end of the heater case 53. That is, a gap 53d is formed in the vertical direction between the exhaust port 55 and the waterproof cover 53c.

[0113] The radiator fan 52 is attached using a mounting plate slightly above the ventilation port 54 of the heater case 53. The radiator fan 52 generates an air flow that contacts the electric heater group 51 from the ventilation port 54 toward the exhaust port 55. The air flow sent from the radiator fan 52 flows along the axial direction of each heater over the heater surface, thereby promoting heat dissipation from the heater surface.

[0114] During the drive of the radiator fan 52, the air flow flows in the order of the ventilation port 54, the surface of the lower electric heater group 51, the surface of the upper electric heater group 51, the exhaust port 55, and the gap 53d. Also, when the electric heater group 51 is energized during the drive of the radiator fan 52, heat dissipation is promoted while the heater surface is cooled by the continuous air flow.

[0115] 〔Fourth Embodiment〕 In the first embodiment, the second load module 50 is placed on the upper surface panel 65 of the housing 62. However, in the third embodiment, the second load module is configured separately from the power generation unit 100. FIG. 14 is a perspective view showing the appearance of the second load module 50 installed alongside the power generation unit assembly 1000. FIG. 15 is a perspective view showing the internal structure of the second load module 50. FIG. 16 is an exploded perspective view for explaining the attachment procedure of the heater cartridge 51a.

[0116] The power generation unit assembly 1000 constitutes a power supply system for supplying power to high-demand power-consuming facilities. In this embodiment, as shown in FIG. 14, the power generation unit assembly 1000 has a configuration in which a plurality of (for example, three) power generation units 100 are installed on the foundation bed 90. Each power generation unit 100 is not equipped with the second load module 50, and the second load module 50 incorporating an electric heater group 51 and the like corresponding to the number of power generation units 100 is installed separately alongside.

[0117] The second load module 50 includes a plurality of sets of electric heater groups 51, a heat dissipation fan 52, and a heater case 53. The electric heater group 51 required for each power generation unit 100 is configured as a heater cartridge 51a. That is, the heater cartridge 51a is an aggregate of electric heaters with a predetermined number of electric heaters as one set. As shown in FIG. 16, the heater cartridge 51a is attached to the plate surface of the support plate 51b using a support tool so that the axial direction of each heater is in the vertical direction. Each heater is arranged in a state of being separated from each other and separated from the plate surface, and has a two-stage configuration in the vertical direction. Further, an opening 51c for allowing an air flow to pass through is formed in the lower region of the heater attachment area on the support plate 51b.

[0118] The heater case 53 is a hollow rectangular parallelepiped without a top plate, a front side plate, and a right side plate, and is arranged such that the longitudinal direction is in the vertical direction. The first heater cartridge 51a is attached as a right side plate to the right side opening of the heater case 53 (see Fig. 16). A closing cover 51e is attached to the opening 51c of this heater cartridge 51a from the outside. Further, a closing panel 53e that is detachable when adding a heater cartridge 51a is attached to the front side opening of the heater case 53 (see Fig. 14).

[0119] A ventilation port 54 is formed below the left side plate of the heater case 53. The radiation fan 52 is attached to this ventilation port 54 using a mounting plate. The upper opening of the heater case 53 is set as an exhaust port 55. Note that a waterproof cover 53c for preventing rainwater from entering the heater case 53 is provided above the upper end of the heater case 53 at a distance. That is, a gap 53d is formed in the vertical direction between the exhaust port 55 and the waterproof cover 53c.

[0120] In this embodiment, three heater cartridges 51a are used for the three power generation units 100. The second and third heater cartridges 51a are accommodated in the space between the first heater cartridge 51a and the left side plate of the heater case 53 as shown in Fig. 15. Note that when adding a heater cartridge 51a, after removing the closing panel 53e, it is inserted and set from the front of the heater case 53.

[0121] The radiation fan 52 generates an air flow that contacts the plurality of electric heater groups 51 from the ventilation port 54 toward the exhaust port 55. The air flow sent from the radiation fan 52 flows along the axial direction of each heater over the heater surface, thereby promoting heat radiation from the heater surface.

[0122] During the operation of the heat dissipation fan 52, the air flow sequentially passes through the ventilation port 54 and the openings 51c of the second and third heater cartridges 51a. This air flow is split for the three heater cartridges 51a and flows over the surfaces of the respective electric heater groups 51. Then, the air flow that has passed through the electric heater groups 51 is discharged to the outside through the exhaust port 55 and the gap 53d. Also, when the electric heater groups 51 are energized during the operation of the heat dissipation fan 52, heat dissipation is promoted while the heater surfaces are cooled by the continuous air flow.

[0123] 4. Other Modification Examples The cell stack 1 constituting the power generation module 20 may be a molten carbonate fuel cell (MCFC) instead of a solid oxide fuel cell (SOFC). The MCFC is a high-temperature operating fuel cell similar to the SOFC and has high power generation efficiency.

[0124] The power generation module 20 using a fuel cell is not limited to the type that generates power with a single-stage cell stack 1, and may be of the type that generates power with a two-stage or more cell stack 1. Specifically, water vapor is removed from the anode off-gas discharged from the previous-stage cell stack to generate a reformed gas, and this reformed gas is supplied to the anode of the next-stage cell stack. In addition, when generating the reformed gas, carbon dioxide contained in the anode off-gas may be removed using a separation membrane, an absorbent, or the like. By configuring to generate power with a two-stage or more cell stack, the fuel utilization rate can be significantly increased.

[0125] The power generation module 20 using a fuel cell is not limited to the configuration of supplying reformed gas to the cell stack, and may be configured to supply pure hydrogen gas. Specifically, hydrogen gas supplied from an external hydrogen production site through a transportation infrastructure is introduced into the anode of the cell stack. When using hydrogen gas as the primary fuel, components (reformer 2, evaporator 4, anode off-gas condenser 7, gas-liquid separator Sa, condensate recovery tank 9, water pump 12, etc.) required for steam reforming and water self-sufficiency can be omitted.

[0126] The power generation unit 100 is not limited to the type using a fuel cell and can be changed to other types. The power generation unit may be of the type using a solar cell, or may be of the type that rotates a generator using an organic Rankine cycle, a steam turbine, a gas turbine, or a gas engine.

[0127] According to the power generation unit 100 of the present embodiment described above, the following effects can be obtained.

[0128] (1) The power generation unit 100 operated in a parallel state or a disconnected state with respect to the commercial power supply system 500 includes a power generation module 20 operated by an auxiliary machine 30, a unit base 60 on which the power generation module 20 and the auxiliary machine 30 are mounted, a housing 62 installed on the unit base 60 so as to surround the power generation module 20 and the auxiliary machine 30, a power conditioner 16 disposed inside the housing 62 for converting the generated power of the power generation module 20 into output power corresponding to the AC power of the commercial power supply system 500, a unit controller 17 disposed inside the housing 62 for controlling the power generation module 20 and the auxiliary machine 30, a self - contained outlet 300 disposed inside or outside the housing 62 for supplying a part of the generated power of the power generation module 20 to the outside when in a disconnected state from the commercial power supply system 500, and load modules 40, 50 disposed inside the housing 62 for consuming a part of the generated power of the power generation module 20 internally when in a disconnected state from the commercial power supply system 500.

[0129] The load module 40 used when in a disconnected state from the commercial power supply system 500 is disposed inside the housing 62 of the power generation unit 100. That is, the load module 40 is incorporated into the power generation unit 100 by using the empty space in the housing 62. Thereby, even if the power generation unit 100 is equipped with the load module 40, an increase in the installation area can be suppressed.

[0130] (2) In the power generation unit 100 of (1), the load module 40 includes a heater case 43 having a ventilation port 44 and an exhaust port 45, an electric heater group 41 housed in the heater case 43, and a heat dissipation fan 42 that generates an air flow contacting the electric heater group 41 from the ventilation port 44 toward the exhaust port 45.

[0131] When the load module 40 operates, the electric heater group 41 is energized and the heat dissipation fan 42 is driven. Since the air flow generated by driving the heat dissipation fan 42 circulates through the narrow space in the heater case 43 from the ventilation port 44 toward the exhaust port 45, heat dissipation from the heater surface is promoted. Thereby, excellent heat dissipation performance that does not cause overheating of the electric heater group 41 can be realized.

[0132] (3) In the power generation unit 100 of (2), the heat dissipation fan 42 in the load module 40 also serves as a ventilation fan in the housing 62.

[0133] By incorporating the load module 40 into the housing 62, it is possible to utilize the ventilation fan in the housing 62 as the heat dissipation fan 42. Since the number of component parts with moving parts can be reduced, the failure risk of the product is reduced. Also, since the power loss of the auxiliary machine 30 does not increase during the operation of the load module 40, high power generation efficiency can be maintained even during self - operation.

[0134] (4) In the power generation unit 100 of (2) or (3), it further includes a mixing box 70 disposed inside the housing 62 and housing a heater case 63. The power generation module 20 includes a cell stack 1 integrating solid oxide fuel cells. The auxiliary machine 30 includes a burner 3 that burns off - gas discharged from the cell stack and a cooling body Zc that cools the cell stack 1 by the flow of cooling air. The mixing box 70 has a gas inlet port 74 for inflowing combustion gas generated by the burner 3 and cooling air that has passed through the cooling body Zc. The air flow generated by driving the heat dissipation fan 42 is discharged while being mixed with the inflowing gas from the gas inlet port 74 in the mixing box 70 after contacting the electric heater group 41.

[0135] The combustion gas Gg generated by the burner 3 is discharged into the atmosphere after being diluted at least by the air flow after the casing ventilation. When the third air blower 15 is driven, the combustion gas Gg is further diluted by the cooling air Ad. Therefore, even if the combustion gas Gg contains flammable hydrogen or toxic carbon monoxide, it can be discharged into the atmosphere after being made safe exhaust for the environment and the human body.

[0136] (5) In the power generation unit 100 of (1), the load module 50 includes a support plate 53a having a ventilation port 54 and an exhaust port 55, an electric heater group 51 supported on the plate surface of the support plate 53a, and a heat dissipation fan 52 that generates an air flow contacting the electric heater group 51 from the ventilation port 54 toward the exhaust port 55. The load module 50 is disposed inside the upper surface panel 65 that constitutes the casing 62.

[0137] When the load module 50 is disposed inside the upper surface panel 65, it is possible to arrange a large number of electric heater groups 51 by utilizing the empty space at the upper part of the casing 62. Therefore, even when increasing the self-generated power, an increase in the installation area of the power generation unit 100 can be suppressed.

[0138] As described above, the embodiments of the present invention have been described. However, the configuration of the present invention is not limited to the above embodiments, and various modifications can be made without departing from the gist of the invention. That is, the above embodiments should be considered as illustrative in all respects and not restrictive. The technical scope of the present invention is shown not by the description of the above embodiments but by the claims, and it should be understood that all modifications belonging to the meaning and scope equivalent to the claims are included.

[0139] 〔Contribution to the Sustainable Development Goals (SDGs) Led by the United Nations〕 The power generation unit and power supply system according to the present disclosure reduce carbon dioxide emissions by improving the primary energy efficiency, and can contribute to the achievement of Goal 13, "Take urgent action to combat climate change and its impacts," of the SDGs (Sustainable Development Goals). In addition, the power generation unit and power supply system according to the present disclosure can maintain power supply independently when a power outage occurs due to a natural disaster, and can contribute to the achievement of Goal 11, "Sustainable cities and communities," of the SDGs.

Description of Reference Numerals

[0140] 1 Cell stack 2 Reformer 3 Burner 4 Evaporator 5 Air preheater 6 Anode off-gas cooler 7 Anode off-gas condenser 7a Fan 8 CO oxidizer (carbon monoxide oxidizer) 9 Condensate recovery tank 10 First primary fuel blower 11 First air blower 12 Water pump 13 Second primary fuel blower 14 Second air blower 15 Third air blower 16 Power conditioner 16a, 16b DC / DC converter 16c Smoothing capacitor 16d Grid-connected inverter 16e, 16f Switch 16g, 16h Control circuit 17 Unit controller 17a Communication unit 20 Power generation module 30 Auxiliary equipment 40 Load module 40 First load module 41 Electric heater (electric heater group) 42 Radiator fan 43 Heater case 44 Vent 45 Exhaust port 50 Second load module 51 Electric heater (electric heater group) 51a Heater cartridge 51b Support plate 51c Opening 51d Opening 51e Closing cover 52 Radiator fan 53 Heater case 53a Support plate 53b Locking part 53c Waterproof cover 53d Gap 53e Closing panel 54 Vent 55 Exhaust port 56 Exterior box 57 Vent 58 Exhaust port 59 Exhaust cover 60 Unit base 62 Housing 63 Unit vent 64 Unit exhaust port 65 Top panel 70 Mixing box 71 Gap 72 Box exhaust port 73 Partition wall 74 Gas inlet port 80 Protection case 81 Vent 82 Exhaust port 90 Foundation bed 100 Power generation unit 300 Stand-alone socket 300a, 300b, 300c Stand-alone socket 400 Socket unit 401 Panel 402 Power lamp 403 Information display section 500 Commercial power system 600 Demand equipment 610 Switchboard 1000-unit assembly (power supply system) Aa, Ab, Ac Air Ad Cooling air B1 First bellows type expansion pipe joint B2 Second bellows type expansion pipe joint B3 Third bellows type expansion pipe joint B4 Fourth bellows type expansion pipe joint E1, E2 Fuel inlets E3, E4, E5 Air inlets E6 Gas outlet Ga, Gf Raw fuel gas Gb Mixed gas Gc Reformed gas Gd Anode off-gas Ge Cathode off-gas Gg Combustion gas La Raw fuel line Lb Mixed gas line Lc Anode fuel line Ld Anode off-gas line Le Cathode air line Lf Cathode off-gas line Lg Combustion gas line Lh Burner cooling air line Li Reformed water line Lj Starting air line Lk Cooling air line Lk1 Collection pipe Lm Cooling water line Ln Feed water line Lw Condensate recovery line Ma First distribution manifold Mb Second distribution manifold Mc First collection manifold Md Second collection manifold R1 First region R2 Second region Sa Gas-liquid separator Sb Water level detector Sc Drain valve Wa Reformed water Wb Condensate Za Heat radiation cylinder Zb Combustion gas pipe Zc Cooling pipe

Claims

1. A power generation unit that operates in a parallel state or a disconnected state with respect to a commercial power supply system, a power generation module operated by auxiliary equipment, a unit base on which the power generation module and the auxiliary equipment are placed, a housing installed on the unit base so as to surround the power generation module and the auxiliary equipment, a power conditioner disposed inside the housing for converting the generated power of the power generation module into output power corresponding to the AC power of the commercial power supply system, a controller disposed inside the housing for controlling the power generation module and the auxiliary equipment, a self - contained outlet disposed inside or outside the housing for supplying a part of the generated power of the power generation module to the outside when in a disconnected state from the commercial power supply system, and a load module disposed inside the housing for consuming a part of the generated power of the power generation module internally when in a disconnected state from the commercial power supply system. The power generation unit.

2. The load module includes a heater case having a ventilation port and an exhaust port, a group of electric heaters housed in the heater case, and a heat dissipation fan for generating an air flow that contacts the group of electric heaters from the ventilation port toward the exhaust port. The power generation unit according to claim 1.

3. In the load module, the heat dissipation fan also serves as a ventilation fan inside the housing. The power generation unit according to claim 2.

4. further includes a mixing box disposed inside the housing and housing the heater case, the power generation module includes a cell stack integrating solid oxide fuel cells, the auxiliary equipment includes a burner for burning off - gas discharged from the cell stack and a cooling body for cooling the cell stack by the flow of cooling air, the mixing box has a gas inlet port for introducing combustion gas generated by the burner and cooling air that has passed through the cooling body, and the air flow generated by driving the heat dissipation fan is discharged while being mixed with the inflowing gas from the gas inlet port inside the mixing box after contacting the group of electric heaters. The power generation unit according to claim 3.

5. The load module includes a support plate having a ventilation port and an exhaust port, a group of electric heaters supported on the plate surface of the support plate, and a heat dissipation fan for generating an air flow that contacts the group of electric heaters from the ventilation port toward the exhaust port. The load module is disposed inside the upper panel constituting the housing The power generation unit according to claim 1.

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