JP5057295B2 - Fuel cell device - Google Patents

Description

  The present invention relates to a fuel cell device that generates power.

  In recent years, as one of the new power generation systems, there has been a fuel cell device using an electrolyte membrane and a catalyst that has an advantage of low-noise power generation that does not generate harmful substances such as NOX and SOX and has low noise. It is considered.

  Such a fuel cell device includes, for example, a reformer that generates hydrogen gas from natural gas, which is a fuel gas, and oxygen (air) as an oxidant, as disclosed in, for example, Patent Document 1. A fuel cell that generates electricity by the electrochemical reaction of the above, an air supply device (air blower) that supplies oxygen (air) to the fuel cell, and power conversion that converts electrical energy generated in the fuel cell into commercial voltage and frequency A device (inverter), a heat recovery device equipped with a heat exchanger, recovers heat generated by the fuel cell or reformer, and supplies heat to other external equipment using exhaust heat, and ventilates the main body (package) The air blower (ventilation fan) to be used and the heat radiating device (cooling module) used for cooling when exhaust heat is not used are basically configured.

In the above basic configuration, in order to smoothly operate each component, water (steam) is supplied to a blower for boosting natural gas, a desulfurizer for removing sulfur from the natural gas, or a reformer. In order to humidify the electrolyte membrane of the fuel cell and the fuel cell, a pump that sends water to the fuel cell, a purification device that removes impurities in the water, an ion exchange device that removes the water electrolyte, fuel gas, air , Various auxiliary devices such as a controller as a control unit for controlling the flow rate of water with a solenoid valve are arranged and physically and electrically connected by piping and wiring.
JP 2002-216828 A

  In addition, in order to operate the fuel cell device normally, it is necessary to fill water in the water flow path in advance, so the solenoid valve and the control valve are opened and closed according to the corresponding flow path, The pump must be driven, and the operation is complicated and requires skill.

  The present invention is intended to solve the above-described problems, and an object of the present invention is to provide a fuel cell device that can easily perform water filling operation of a flow path related to water circulation.

According to the fuel cell device of the first aspect of the present invention, the means provided in the control unit automatically executes the water filling operation of the target flow path so as to keep the water level in the water storage unit constant . Therefore, it is possible to easily perform the water filling operation of the flow path related to the water circulation.

  According to the fuel cell device of the second aspect of the present invention, the valve portion and the pump portion provided in the target flow path can be automatically controlled at an appropriate timing. Can be eliminated.

  According to the fuel cell device of the first aspect of the present invention, it is possible to easily perform the water filling operation of the flow path related to the water circulation.

  According to the fuel cell device of the second aspect of the present invention, the complexity of the water filling operation in the device can be eliminated.

  Hereinafter, an embodiment of a fuel cell device according to the present invention will be described with reference to the accompanying drawings. In FIG. 1 showing the overall configuration of the apparatus, reference numeral 1 denotes a fuel inlet for taking in city gas as fuel gas. This fuel inlet 1 passes through a desulfurizer 3 comprising a fuel cutoff valve 2, activated carbon and the like. , Connected to the inlet side of the fuel booster blower 4. The fuel booster 4 is for boosting the fuel gas, and one of its outlets is connected to the inlet of the reformed fuel shut-off valve 5, and the outlet of the reformed fuel shut-off valve 5 also functions to preheat the fuel gas. It is connected to the reforming section inlet 7 a of the reformer 7 via the heat receiving side of the CO converting / removing device 6. The reformer outlet 7 b of the reformer 7 is connected to the inlet of the CO converter / remover 6 made of a catalyst via the heat release side of the fuel preheater 6. Then, the outlet of the CO conversion / removal device 6 is connected to the inlet of the anode 16 of the fuel cell 15 via the first steam thermal combustor 13.

  On the other hand, the outlet of the fuel booster blower 4 is separately connected to the burner section 7c of the reformer 7 via a start burner fuel cutoff valve 19 which is a first burner cutoff valve. The outlet of the anode 16 of the fuel cell 15 also passes through the off-gas heat exchanger 21 and is connected to the burner portion 7c of the reformer 7 via the main burner fuel cutoff valve 22 which is the second burner cutoff valve. Is done.

  A burner exhaust gas outlet of the reformer 7 is connected to an exhaust heat exchanger 25 via a second steam heat exchanger 24. Further, the exhaust heat heat exchanger 24 is connected to the exhaust heat exchanger 25 so that the outlet of the cathode 17 of the fuel cell 15 joins in the middle of the connection from the second steam heat exchanger 24 to the exhaust heat exchanger 25. In the middle of the pipeline leading to 25, the pipeline from the cathode 17 outlet of the fuel cell 15 is connected. As a result, the combustion exhaust gas that has passed through the second steam heat exchanger 24 from the burner portion 7 c of the reformer 7 is sent to the exhaust heat exchanger 25 together with the cathode exhaust gas from the cathode 17 of the fuel cell 15. It is like that.

  The fuel cell 15 sandwiches an electrolyte membrane 18 made of a solid polymer between an anode 16 and a cathode 17 as an electrode carrying a catalyst, and sends fuel gas and air to the anode 16 and the cathode 17 respectively. For example, a separator (not shown) in which a flow path is formed is provided. A cathode air blower 28 as a first air supply device is connected to the cathode 17 of the fuel cell 15 through the cathode air control valve 29. Reference numeral 31 denotes a selective oxidation air blower as a second air supply device, which is connected to the inlet of the CO selective oxidizer 12 through the oxidation air control valve 32. Further, 33 is a burner air blower as a third air supply device, which is connected to the burner portion 7 c of the reformer 7 through the burner air control valve 34.

Reference numeral 37 denotes a city water inlet, and the city water inlet 37 is connected to an inlet of a city water pressure regulating valve 38 that restricts the inflow amount of city water. The outlet of the city water pressure regulating valve 38 is connected to the cold water side of the hot water storage tank 39, one of which is a heat-utilizing external device, and the other is connected to the water storage section 25a of the exhaust heat exchanger 25 via the city water shutoff valve 40. Connected to. Condensed water stored in the water storage section 25a of the exhaust heat exchanger 25 passes through a water shutoff valve 44 and a water purification device 45 including a filter, and branches to the outlet side of the water purification device 45 for connection. It is supplied to the cooling water pump 46 and the reforming water pump 47, respectively. The discharge port of the cooling water pump 46 is connected to the anode 16 of the fuel cell 15, while the discharge port of the reforming water pump 47 is the first steam heat exchanger 13 and the second steam heat exchanger. The steam control valve 49 is connected to the inlet of the steam control valve 49 via a heat receiving side flow path formed by sequentially connecting the 24, and the outlet of the steam control valve 49 is connected to the outlet of the reformed fuel cutoff valve 5.

  Reference numeral 51 denotes a circulation pump, which feeds cold water drawn from the hot water storage tank 39 as hot water to the hot water storage tank 39 again from the off-gas exchanger 21 via the heat receiving side passage 25b of the exhaust heat exchanger 25. Thus, hot water is stored in the upper part of the hot water tank 39.

  55 is a control device for controlling the operation of each part of the device described above, which includes the pumps 46, 47, 51, the blowers 4, 28, 31, 33, and the shut-off valves 2, 5, 19, 22 , 40, 44, control valves 29, 32, 34, 49, input / output devices such as sensors (not shown), and a control program as a software function. Although not shown in the figure, in addition to various sensors for monitoring the flow and temperature of air and water, a controller for setting conditions, a switch (electromagnetic valve), and the like are also provided in the control device 55. It is built into the device in an electrically connected state. Furthermore, 56 is an inverter for converting the generated DC power into AC power having a commercial voltage and frequency. The above-described components other than the city water pressure regulating valve 38, the hot water tank 39, and the hot water outlet shut-off valve 52 are accommodated in an apparatus body 57 that is a package.

  From the waste heat exchanger 25 to the ion exchange device 43, the water shutoff valve 44, the water purification device 45, the reforming water pump 47, the first steam heat exchanger 13, the CO conversion / removal device 6, and the steam control valve 49. FIG. 4 shows a configuration for filling the reforming water line 74 that reaches the reformed fuel cutoff valve 5 with water.

  The control device 55 includes water filling processing means 75 for processing and executing water filling of the reforming water line 74 as a program function on software. This water filling treatment means 75 connects a water level gauge 76 provided in the exhaust heat exchanger 25 to the input side port, and also includes a reformed fuel shut-off valve 5, a reformed water pump 47, a water shut-off valve 44, a steam control. The valve 49, the city water pressure regulating valve 38, and the city water shutoff valve 40 are connected to the output side port.

  Next, the effect | action is demonstrated about the said structure. When an operation as a fuel cell device is started by turning on a start switch (not shown), fuel gas is sent out to the desulfurizer 3 via the fuel cutoff valve 2 opened from the fuel intake 1. Here, sulfur contained in the fuel gas is removed by the adsorption action of the desulfurizing agent. The purpose of removing the sulfur content by the desulfurizer 3 is to prevent the subsequent catalyst such as the reformer 7 from being deteriorated by the fuel sulfur content.

  The fuel gas that has passed through the desulfurizer 3 is boosted by the booster blower 4, and then sent to the burner section 7 c of the reformer 7 through the opened start burner fuel cutoff valve 19. Further, the air fed from the burner air blower 33 is mixed and burned with the fuel gas in the burner portion 7c of the reformer 7 through the burner air control valve 34, and the reformer 7 is brought to a temperature required for reforming. Raise the temperature. On the other hand, the burner exhaust gas (combustion exhaust gas) discharged from the burner portion 7 c of the reformer 7 passes through the fourth steam heat exchanger 24 and exits from the cathode 17 of the fuel cell 15 (cathode exhaust). The gas is sent to the exhaust heat exchanger 25 together with the gas) to release the thermal energy it has.

  When the reformer 7 rises to the set temperature, the control device 55 opens the reformed fuel cutoff valve 5. In this case, the combustion gas that has passed through the reformed fuel cutoff valve 5 from the fuel booster blower 4 is mixed with the water vapor generated in the CO conversion / removal device 6, and this mixed combustion gas passes through the CO conversion / removal device 6. It passes through the reforming unit 7a of the reformer 7. The reforming section 7a is heated to about 750 ° C. by the burner section 7c, and the fuel gas is changed into hydrogen gas and carbon dioxide (carbon dioxide) by the action of the catalyst. However, although the gas produced here contains a little amount of carbon monoxide, the performance of the polymer electrolyte fuel cell 15 described later is remarkably deteriorated by carbon monoxide. Must be below a certain value.

  The fuel gas that has passed through the reformer 7 enters the CO conversion / removal device 6, where carbon monoxide reacts with water vapor to change into hydrogen gas and carbon dioxide by the action of the catalyst, and the concentration of carbon monoxide is changed. It can be reduced to a fairly low level. The fuel gas passing through the CO conversion / removal device 6 is mixed with the air (oxygen) sent by the selective oxidizing air blower 31, and the carbon monoxide contained therein is changed to carbon dioxide by the action of the catalyst. At this time, the concentration of carbon monoxide contained in the fuel gas can be lowered to a concentration that does not adversely affect the fuel cell 15 for the first time.

  The fuel gas that has passed through the CO conversion / removal device 6 is sent to the anode 16 that is one electrode of the fuel cell 15. Air (oxygen) is fed into the cathode 17 as the other electrode from the cathode air blower 28 through the cathode air control valve 29. The hydrogen of the anode 16 is ionized by the action of the catalyst, passes through the electrolyte membrane 18 and is combined with oxygen on the cathode 17 side. Thereby, when water is generated, reaction heat is generated. Further, due to this electrochemical reaction, a negative electrode potential is generated at the anode 16 and a positive electrode potential is generated at the cathode 17, and electric power can be taken out from the fuel cell 15.

  The fuel gas that has passed through the anode 16 consumes most of the hydrogen gas, but still contains a considerable concentration of hydrogen gas and some water vapor, and this is part of the water vapor by the off-gas heat exchanger 21. Is removed from the main burner fuel shut-off valve 22 to the burner section 7c of the reformer 7 and mixed with the air fed from the burner air blower 33 through the burner air regulating valve 34. Burn in part 7c. In this state, the start burner fuel cutoff valve 22 is closed by the control device 55, and the burner portion 7 c of the reformer 7 continues combustion using the remaining hydrogen gas (off-gas) that has passed through the anode 16.

  The air that has passed through the cathode 17 has water (water vapor) generated in the fuel cell 15 and heat, and this air returns to the condensed water by being cooled by passing through the exhaust heat exchanger 25. Further, the water sucked from the lower part of the hot water tank 39 by the circulation pump 51 passes through the heat receiving side of the exhaust heat exchanger 25 through the off-gas heat exchanger 21, is warmed, and gradually accumulates in the upper part of the hot water tank 39. Going to be.

  Condensed water stored in the water storage section 25a of the exhaust heat exchanger 25 enters the water purification device 45 from the opened water shut-off valve 44 to remove impurities. The water purified by the water purification device 45 is sent to the anode 16 of the fuel cell 15 by the cooling water pump 46 and used for humidifying the solid polymer membrane (electrolyte membrane 18) and cooling the fuel cell 15. Similarly, the water sent to the third steam heat exchanger 13 by the reforming water pump 47 passes the fourth steam heat exchanger 24, the CO conversion / removal unit 6 from the third steam heat exchanger 13. The fuel gas is mixed with the fuel gas from the steam control valve 49 that is passed through and heated to become steam. Further, the DC power is converted into commercial power / frequency AC power by inverters 56 respectively connected to the anode 16 and the cathode 17 of the fuel cell 15. With the above operation, the fuel cell device can generate power.

  Next, the operation of the heat utilizing external device including the hot water tank 17 will be described. First, before operating the fuel cell device, the city water pressure regulating valve 38 and the city water shut-off valve 40 are opened, and the city water taken from the city water inlet 37 is filled in the hot water storage tank 39. Thereafter, when the operation of the fuel cell device is started, the circulation pump 51 is operated, and the cold water in the hot water storage tank 39 is sent to the off-gas heat exchanger 21 and the exhaust heat exchanger 25 by the circulation pump 51, and the cathode 17 of the fuel cell 15. Or the heat energy of the exhaust gas from the burner part 7c of the reformer 7 is scooped into hot water. This hot water is sent from the exhaust heat exchanger 25 to the hot water inlet of the hot water tank 39 and returns to the hot water tank 39 again. The inside of the hot water storage tank 39 is in a two-layer state due to the difference in water temperature. The hot water is located in the upper layer of the hot water storage tank 39 and the cold water is located in the lower layer of the hot water storage tank 39. Here, it becomes possible to use the hot water in the upper layer of the hot water tank 39.

  The operation procedure in the case of performing water filling of the reforming water line 74 will be described. In this case, using the input means, the system of the control device 55 is set to the water filling inspection mode, and the water filling inspection processing means 75 performs the reforming water line. While the water shutoff valve 44 and the steam control valve 49 in the middle of 74 are opened, the reformed fuel shutoff valve 5 at the end of the reforming water line 74 is closed. Next, the water filling processing means 75 operates the reforming water pump 47 to pass the water stored in the water storage unit 25a of the exhaust heat exchanger 25 through the water purifier 45, and from the exhaust heat exchanger 25 to the steam control valve 49. Fill the flow path up to with water. The water level in the water storage section 25a is detected by a water level gauge 76 provided in the exhaust heat exchanger 25, and the water filling processing means 75 is based on the detection output of the water level gauge 76 and The water level in the water reservoir 25a is kept constant by controlling the opening and closing, and consequently the inflow of city water into the exhaust heat exchanger 25.

  Further, in order to determine whether or not the water in the reforming water line 74 up to the steam control valve 49 is filled, it is sufficient that the water is filled beyond the fourth steam heat exchanger 24. For example, the determination may be made based on the drive time of the reforming water pump 47, or else a determination may be made based on the detection output from the water level detection means provided in the middle of the reforming water line 74.

  As described above, in this embodiment, in the fuel cell device that generates power by the electrochemical reaction between the fuel gas and the oxidant gas, the water filling treatment means as a means for executing the water filling of the reforming water line 74 that is a flow path. 75 is provided in the control device 55 of the apparatus.

  If it does in this way, the water filling processing means 75 with which the control apparatus 55 was equipped will automatically perform the water filling operation | work of the water line 74 for a target modification | reformation. Therefore, it is possible to easily perform the water filling operation of the reforming water line 74 related to the water circulation.

  In particular, the water filling treatment means 75 of the present embodiment opens and closes or opens valves (reformed fuel shutoff valve 5, water shutoff valve 44, steam control valve 49, etc.) provided in the reforming water line 74 which is a flow path. The operation of the pump unit (reforming water pump 47 and the like) is controlled.

  In this way, since the valves and pumps provided in the target reforming water line 74 can be automatically controlled at an appropriate timing, the complexity of the water filling operation in the apparatus can be eliminated. .

  Here, the flow path includes not only the reforming water line 74 but also a battery cooling water line and a heat recovery water line.

  In another reference example, in a fuel cell device that generates power by an electrochemical reaction between a fuel gas, which is a gas, and an oxidant gas (oxygen in the air), a flow path (for example, a fuel reformer) provided in the device A leak inspection processing means 71 as a means for executing the inspection of the line 61), that is, the leak inspection is provided in the control device 55 which is a control unit for controlling the operation of each part of the apparatus.

  If it carries out like this, the leak test process means 71 with which the control apparatus 55 was equipped will automatically perform the leak test of the flow path used as test object. Therefore, it is possible to easily perform the leak inspection work of the apparatus.

  In this reference example, in particular, the gas pressure adjusting means 64, the inspection gas shutoff valve 65 corresponding to the opening / closing operation means for the opening of the inspection line, the pressure measuring means 66, and the inspection gas are provided in the flow path to be inspected. An inspection device 68 for injection is provided, and signal connection portions 55 a and 55 b with the inspection device 68 are provided in the control device 55.

  In this way, if the signal connection portions 55a and 55b of the control device 55 are connected to the inspection device 68, the leak inspection processing means 71 automatically controls the operation of the inspection device 68 at an appropriate timing. The complexity of the leak inspection work in the inspection device 68 can be eliminated.

  Furthermore, in this reference example, the opening / closing or opening of the valve portions (each shutoff valve 2, 5, 19, 22, 40, 44 and each control valve 29, 32, 34, 49) provided in the flow path to be inspected. Is controlled by the leak inspection processing means 71.

  In this way, the valve portion provided in the flow path to be inspected can be controlled automatically at an appropriate timing instead of manually, thus eliminating the complexity of leak inspection work in the apparatus. be able to.

  Further, in this reference example, the inspection pressure from the pressure measuring means 66 is read, and the pressure adjusting means 64 is controlled so that the inspection pressure becomes stable. When the inspection pressure is stabilized, it is provided in the piping portion 67 which is a gas supply line. The inspection gas shut-off valve 65 is closed, the pressure drop value of the flow path (for example, the fuel reforming line 61) after the set time is compared with the inspection standard value, and the comparison result is output to the output means 72 with sound and light. , Display and so on.

  If it does in this way, it can be checked by sound, light, a display, etc. whether the fuel reforming line 61 used as inspection object is leaking.

  Here, the flow path is not only the fuel reforming line 61 but also the starting fuel line, the combustion air / exhaust gas line, the cathode air line, the reforming / battery cooling water line, and the heat recovery line. Including lines.

  The present invention is not limited to the above examples and reference examples, and various modifications can be made within the scope of the gist of the present invention. For example, although the polymer electrolyte fuel cell device has been described in the examples and reference examples, other power generation methods such as a molten carbon type and a solid oxide type may be used. In addition, the configuration of the fuel cell device is not limited to that of the present embodiment and the reference example. In the embodiment, the water filling processing means is incorporated, and in the reference example, the leak inspection is incorporated as a software function of the control device 55. Although an example is shown, a processing unit relating to another inspection may be provided in the control device 55, and when the inspection device 68 is connected to the flow path, the processing unit may automatically execute the inspection in the same manner.

It is a schematic explanatory drawing which shows the system configuration | structure of the fuel cell apparatus in one Example of this invention. It is a schematic explanatory drawing which shows the system configuration | structure of the fuel cell apparatus at the time of the leak test of one reference example of this invention. It is a block block diagram of a fuel cell apparatus related to the leak inspection of the fuel reforming line. It is a block block diagram of the fuel cell apparatus regarding the water filling in one Example of this invention. It is a flowchart which shows the procedure of the leak test | inspection of the fuel reforming line in one reference example of this invention.

2, 5, 19, 22, 40, 44 Shut-off valve (valve part)
25 Waste heat exchanger
25a Water storage part 29, 32, 34, 49 Control valve (valve part)
46, 47, 51 Pump (pump part)
55 Control device (control unit)
55a, 55b Signal connection part 74 Water line for reforming (flow path)
75 Water filling treatment means (means)
76 Water level gauge

Claims (2)

In a fuel cell device that generates electricity by chemical reaction of gas,
Exhaust heat provided means for processing run the water filling of the flow path including the exchanger to the control unit of the device Rutotomoni, the exhaust heat exchanger water gauge the exhaust heat exchanger for detecting the water level in the water storage portion Provided in
The means controls the inflow amount of water by water filling into the exhaust heat exchanger based on the detection output of the water level meter, and keeps the water level in the water reservoir constant. Fuel cell device.   2. The fuel cell device according to claim 1, wherein the means controls a valve part and a pump part provided in the flow path.

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