JP2010287518A - Fuel cell power generator - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a fuel cell power generator for reliably preventing freezing, by avoiding damage of a water circuit and a part by freezing, when becoming a further lower temperature environment than the limit temperature (the lower limit temperature) capable of freezing-preventive operation. <P>SOLUTION: The fuel cell power generator can avoid the damage of a water passage and the part by the freezing, by forcibly draining water in at least one passage of a cooling water circulating passage 113, a water collecting passage 109 and a mutual circulating passage 117, before the freezing starts by elapsed time of becoming the limit temperature or smaller and a lowering speed of the detecting temperature, when becoming the further lower temperature environment than the limit temperature (the lower limit temperature) capable of the freezing-preventive operation, by having a control means for performing draining operation of the water in at least any one passage of the cooling water-circulating passage 113, the water collecting passage 109 and the mutual circulating passage 117 as the freezing preventive operation, when a temperature-detecting means 10 detects the temperature of a second threshold value or smaller being a first threshold value or smaller for a predetermined time. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a fuel cell power generator, and more particularly to prevention of freezing of a water path.

  Conventionally, various proposals have been made regarding prevention of freezing of the water path in this type of fuel cell power generator (see, for example, Patent Document 1).

  FIG. 5 shows a configuration diagram of a conventional fuel cell power generator described in Patent Document 1. In FIG. As shown in FIG. 5, the fuel cell 104, the cooling water circulation path 113 for cooling the fuel cell 104, the water recovery path 109 for recovering the water in the reaction product water and the exhaust gas, the water recovery path 109, and the cooling water circulation A mutual circulation path 117 that circulates between the path 113, a heating means 114 provided in the mutual circulation path 117, and a temperature detection means 120 for performing anti-freezing operation, and the temperature detection means 120 is below a threshold value When the temperature is reached, as the freeze prevention operation, the water in the cooling water circulation path 113 and the water in the mutual circulation path 117 are circulated and the heating means 114 is operated.

  101 is a reformer that converts the raw material supplied from the raw material supply means 102 into a hydrogen-rich gas by a reforming reaction by the heat of the burner 103. Reference numeral 104 denotes a fuel cell that generates electricity by reacting the hydrogen-rich gas generated in the reformer 101 and supplied through the hydrogen supply path 105 with air as an oxidant gas. The fuel cell 104 generates a hydrogen electrode 104a and an air electrode 104b. Have. Reference numeral 106 denotes an exhaust hydrogen path that connects the hydrogen electrode 104 a of the fuel cell 104 and the burner 103. An air supply means 107, a condenser 108 and a water recovery path 109 are connected to the air electrode 104 b of the fuel cell 104. An exhaust air path 110 is connected to the water recovery path 109 and is connected to the reformer 101 via a reforming water supply path 112 including a reforming water supply device 111. Reference numeral 113 denotes a cooling water circulation path for cooling the heat generated in the fuel cell 104. The cooling water circulation path 113 includes heating means 114, and the cooling water is circulated by the cooling water pump 116 between the fuel cell 104 and the heat exchange device 115. Yes. 117 is a mutual circulation path that communicates between the water recovery path 109 and the cooling water circulation path 113, and circulates water in both paths by the pump 118, and includes a water purifier 119. Reference numeral 120 denotes a temperature detection means, and 121 denotes a control device.

  Next, the operation of the anti-freezing operation of this conventional fuel cell power generator will be described.

  When there is no power generation request of the fuel cell 104, when the temperature detection unit 120 detects a temperature below a threshold (the threshold is a temperature at which freezing can be avoided by the freeze prevention operation), for example, 0 ° C. or less, the fuel cell 104 is set as the freeze prevention operation. Without generating electricity, the cooling water pump 116 of the cooling water circulation path 113 and the pump 118 of the mutual circulation path 117 are circulated, and the heat generated by the heating means 114 is operated to the cooling water circulation path 113 and the mutual circulation path 117. Then, it is transmitted to the water recovery path 109 and controlled by the control device 121 so as to prevent the water in each path from being frozen.

Japanese Patent No. 4013609

  However, in the conventional configuration, in order to prevent freezing, the water in the cooling water circulation path and the water in the mutual circulation path are respectively circulated and the heating means is operated. Generally, the water circulation and the heating means in the path are operated. There is also an operating limit temperature (lower limit temperature) in the anti-freezing operation combined with the heating action by, and if a low temperature state exceeding this lower limit temperature continues, water circulation cannot be maintained, freezing starts from the coldest part and finally In reality, each water path freezes and in the worst case, the equipment is damaged. As a result, there was a problem that due to the damage of the equipment due to freezing, power generation becomes impossible at the start of the next power generation (at the time of start-up), or electric leakage due to water leakage from the damaged part occurs, resulting in an unsafe state.

  The present invention solves the above-described conventional problems, and prevents damage to water circuits and parts due to freezing even when the temperature becomes lower than the limit temperature (lower limit temperature) at which anti-freezing operation is possible. It is an object of the present invention to provide a fuel cell power generator that performs reliably.

  In order to solve the above problems, a fuel cell power generator according to the present invention includes a fuel cell, a cooling water circulation path for cooling the fuel cell, a water recovery path for recovering water in the reaction product water and the exhaust gas, and A mutual circulation path that circulates between the water recovery path and the cooling water circulation path, heating means provided in any one of the cooling water circulation path, the water recovery path, and the mutual circulation path, and a predetermined inside of the system Or a temperature detecting means provided at a position for detecting the outside air temperature, and when the temperature detecting means detects a temperature equal to or lower than a first threshold in the power generation stop state of the fuel cell, The water in the cooling water circulation path and the water in the mutual circulation path are circulated, the heating means is operated, and the temperature detection means has a temperature not higher than a second threshold value that is not higher than a first threshold value. When detecting for a predetermined time, as a freeze prevention operation, it has a control means for draining the water in at least one of the cooling water circulation path, the water recovery path, and the mutual circulation path, It is a thing.

  According to such a configuration, when the temperature becomes lower than the limit temperature (lower limit temperature) at which anti-freezing operation is possible, the cooling is performed before freezing starts due to the elapsed time when the temperature has become lower than the limit temperature and the decrease rate of the detected temperature. By forcibly draining water in at least one of the water circulation path, the water recovery path, and the mutual circulation path, damage to the water path and parts due to freezing of the fuel cell power generation device can be avoided.

  Further, the present invention is characterized by having warning means for giving a warning notification that drainage is started.

  According to such a configuration, it is possible to alert the user in advance that drainage starts automatically by giving a warning that drainage is started, and inadvertently perform power generation operation immediately before drainage starts. It is possible to provide a fuel cell power generator that is safe and convenient.

  Further, the warning means is provided in a remote controller or an information equipment terminal that controls the operation of the fuel cell.

  According to such a configuration, a fuel cell that is user-friendly and easy-to-use can be reliably communicated by informing and guiding the freeze-free operation by draining with a remote control or portable information device terminal that is easy to operate and recognize. A power generation device can be provided.

  Further, the warning means is characterized by notifying that the water is being drained during draining.

According to such a configuration, it is possible to alert the user that water is being drained automatically by giving a warning that the water is being drained, and the power generation operation may be erroneously performed while draining water. Therefore, a safe and convenient fuel cell power generator can be provided.

  The temperature detecting means is attached to a position where the water temperature in each path is the lowest.

  According to such a configuration, the temperature is detected at the position where the temperature for preventing freezing is lowest, so that the freeze preventing operation is performed reliably and a highly reliable fuel cell power generator can be provided.

  The fuel cell power generation device of the present invention also includes at least one of the cooling water circulation path, the water recovery path, and the mutual circulation path before starting freezing even when the temperature becomes lower than the limit temperature (lower limit temperature) at which freeze prevention operation is possible. By forcibly draining water in one path, damage to the water path and parts due to freezing can be avoided, and a highly reliable fuel cell power generator can be provided.

1 is a system configuration diagram of a fuel cell power generator according to Embodiment 1 of the present invention. The characteristic view which shows the relationship between detected temperature (Ta) and elapsed time (Tx) in Embodiment 1 of this invention The characteristic view which shows the relationship between detected temperature (Ta) and elapsed time (Tx) in Embodiment 1 of this invention System configuration diagram of a fuel cell power generator according to Embodiment 2 of the present invention System configuration diagram of conventional fuel cell system

  The first invention includes a fuel cell, a cooling water circulation path for cooling the fuel cell, a water recovery path for recovering water in the reaction product water and the exhaust gas, the water recovery path, and the cooling water circulation path. An internal circulation path that circulates between them, heating means provided in any one of the cooling water circulation path, the water recovery path, and the mutual circulation path, and a predetermined position inside the system or a position that detects an outside air temperature. Temperature detection means, and when the temperature detection means detects a temperature equal to or lower than a first threshold in the power generation stop state of the fuel cell, water in the cooling water circulation path and the mutual circulation path are used as a freeze prevention operation. When the temperature detection means detects a temperature below a second threshold value that is less than or equal to a first threshold value for a predetermined time, It has a control means for draining water in at least one of the cooling water circulation path, the water recovery path, and the mutual circulation path, and is based on the limit temperature (lower limit temperature) at which anti-freezing operation is possible. Even in a low-temperature environment, before freezing starts due to the passage of time when the temperature is lower than the limit temperature and the detection temperature decrease rate, the cooling water circulation path, the water recovery path, and the mutual circulation path must be connected. It is possible to provide a fuel cell power generator that forcibly drains water and avoids damage to water paths and parts due to freezing.

  In particular, the second invention is characterized in that, in the first invention, there is provided warning means for giving a warning notice that drainage is started. By alerting the user that the water will start, the user can be alerted in advance that water draining will start automatically. And a convenient fuel cell power generator.

A third invention is characterized in that, in particular, in the second invention, the warning means is provided in a remote control or information equipment terminal that controls the operation of the fuel cell, and the remote control or portable device that is easy to operate and recognize by a user. By informing and guiding the antifreezing operation by draining with the information equipment terminal, it is possible to reliably transmit information and provide a fuel cell power generator that is easy to use.

  According to a fourth aspect of the invention, in particular, in the second or third aspect of the invention, the warning means informs that the water is being drained during drainage, and warns and guides that the drainage is in progress. Thus, it is possible to alert the user that water has been drained automatically, and it is possible to provide a safe and convenient fuel cell power generator without performing a power generation operation accidentally during draining.

  The fifth invention is characterized in that, in particular, in any one of the first to fourth inventions, the temperature detecting means is mounted at a position where the water temperature in each path is the lowest, and the temperature for preventing freezing is Since the temperature is detected at the lowest position, the freeze prevention operation is reliably performed, and a highly reliable fuel cell power generator can be provided.

  Embodiments of the present invention will be described below with reference to the drawings. Note that the present invention is not limited to the embodiments.

(Embodiment 1)
FIG. 1 is a system configuration diagram of a fuel cell power generator according to Embodiment 1 of the present invention. 1, those having the same functions as those of the conventional fuel cell power generator shown in FIG. 5 are given the same reference numerals, and the details of those functions are the same as those in FIG. To do.

  As shown in FIG. 1, reference numeral 10 denotes a temperature detection unit of the fuel cell power generator according to Embodiment 1 of the present invention, and is attached to a position where the water temperature below the water recovery path 9 can be detected. As long as the temperature detection means 10 is effective as a place for detecting the temperature in order to prevent the water in the path from freezing, the temperature detection means 10 may be any place, whether inside or outside the fuel cell power generator. In order to detect the start reliably, it is preferable to provide at the position where the residual water temperature in each path becomes the lowest. 11 is a drain valve for discharging the water of the water recovery path 109, 12 is a drain valve for discharging the water of the mutual circulation path 117, and the water of the cooling water circulation path 113 is also mutual. Since it communicates with the circulation path 117, it is connected so that water can be drained at the same time. 13 inputs the detected temperature from the temperature detecting means 10 and opens the water drain valve 11 and the water drain valve 12 to remove the water in the cooling water circulation path 113, the water recovery path 109 and the mutual circulation path 117. It is a control means for draining operation.

  Next, the operation of the freeze prevention operation in the first embodiment will be described. When there is no power generation request of the fuel cell 104, the temperature detecting means 10 is not more than a first threshold value (the first threshold value circulates water in the cooling water circulation path 113 and water in the mutual circulation path 117, and heating means) 114 is operated and the anti-freezing operation is started), for example, a temperature of 0 ° C. or less is detected, the cooling water pump 116 and the mutual circulation of the cooling water circulation path 113 are not generated as the anti-freezing operation without generating the power of the fuel cell 104. Each of the pumps 118 in the path 117 is operated to circulate water, and the heating means 114 is operated to transmit the generated heat to the cooling water circulation path 113, the mutual circulation path 117, and the water recovery path 109 to prevent water in each path from freezing. Thus, the control means 13 controls the circulation and heating.

  The water in the reforming water supply path 112 is prevented from freezing by dropping into the water recovery path 109 by a drop when the reforming water supply apparatus 111 is not operated.

Next, when the freeze prevention operation is performed, the temperature detection means 10 operates at a second threshold value equal to or lower than the first threshold value (water freeze in the cooling water circulation path 113 and water circulation in the mutual circulation path 117 and the freeze prevention that operates the heating means 114. At a lower limit temperature T2 (hereinafter referred to as T2) that can avoid freezing during operation, for example, −1
When detecting a temperature equal to or lower than 0 ° C., the control means 13 monitors the detected temperature (Ta) and the elapsed time (TX) from the temperature detecting means 10 after the temperature falls below the second threshold value T2.

  FIG. 2 shows an example of the relationship between the detected temperature (Ta) of the temperature detecting means 10 and the elapsed time (Tx).

  In FIG. 2, the integration of the elapsed time (TX) of the temperature difference (Td) between the detected temperature (Ta) from the temperature detecting means 10 and the second threshold (T2) from when the value falls below the second threshold (Tx1). When the value (A = Σ (Ta−T2)) reaches a predetermined level (AL: hatched portion between Tx1 and Tx2 in FIG. 2), that is, when Tx2 is reached, the control means 13 11. Open the water drain valve 12 and start draining from the cooling water circulation path 113, the water recovery path 109, and the mutual circulation path 117. This Tx2 is to open the drainage valve 11 and the drainage valve 12 from the predicted time point when the detected temperature (Ta) from the temperature detecting means 10 changes at the rate of decrease as it is, and freezes at Tx3. This is a point in time when there is enough time to complete draining of water in the cooling water circulation path 113, the water recovery path 109, and the mutual circulation path 117. That is, it is predicted that the integrated value (A = Σ (Ta−T2)) freezes when it reaches AL + BL (the sum of the hatched portions between Tx1 to Tx2 to Tx3 in FIG. 2). Then, after the temperature falls below the lower limit temperature (T2) at which freezing can be avoided in the antifreezing operation that operates the water circulation and the heating means 114, freezing starts from the most cooled part of the water path or the parts having the water path due to the temperature drop. Prior to (Tx3), draining can be completed at time Tx3 by draining water at time Tx2.

  FIG. 3 shows another example of the relationship between the detected temperature (Ta) of the temperature detecting means 10 and the elapsed time (Tx).

  In FIG. 3, the detected temperature (Ta) from the temperature detecting means 10 after falling below the second threshold value (T2) falls below the second threshold value when the temperature drop becomes gentle due to the subsequent temperature change. The integrated value (A = Σ (Ta−T2)) of the elapsed time (TX) of the temperature difference (Td) between the detected temperature (Ta) from the temperature detecting means 10 and the second threshold value (T2) after Approach the level (AL) slowly. Further, when the subsequent temperature change starts to increase in temperature, the integrated value (A = Σ (Ta−T2)) becomes the total value (AL + B) of the hatched portion between Tx1 to Tx2 to Tx3 in FIG. In order to reduce the amount of water, the cooling means circulation path 113, the water recovery path 109, and the mutual circulation path 117 are not drained by opening the drain valve 11 and the drain valve 12 by the control means 13. Can be prevented.

  Thus, in the freeze prevention operation of the first embodiment, the temperature detected by the temperature detection means 10 is lower than the lower limit temperature (T2) at which freezing can be avoided in the freeze prevention operation that operates the water circulation and the heating means 114. When the temperature drops gradually or changes to a temperature rise in response to the temperature change from the cooling water circulation path 113 and water recovery by opening the drain valve 11 and drain valve 12, etc. Freezing can be prevented without draining the route 109 and the mutual circulation route 117, the temperature continues to drop, and then there is no increase in temperature. When it becomes a situation where it is predicted that the water drainage cannot be performed, the cooling water circulation path 1 by opening the water drain valve 11 and the water drain valve 12 at a time when the time required for water draining can be secured. By performing 3 and drain paths of the water collecting path 109 and mutual circulating passage 117 to force it it is possible to avoid damage to the water circuit and water pathway components by freezing.

In the present embodiment, when Tx2 is reached, the control means 13 opens the water drain valve 11 and the water drain valve 12, and the cooling water circulation path 113, the water recovery path 109, and the mutual circulation path 117 are opened. Although all the water is drained from the path, water circuit and water path parts are damaged due to freezing by draining water in any one of the cooling water circulation path 113, the water recovery path 109, and the mutual circulation path 117. Needless to say, if it is possible to avoid this, it is sufficient to drain the water only in one route.

(Embodiment 2)
FIG. 4 is a system configuration diagram of the fuel cell power generator according to Embodiment 2 of the present invention. The same reference numerals are given to the same components as those in the first embodiment, and the description thereof is omitted.

  In the present embodiment, reference numeral 14 denotes a remote controller that controls the operation of the fuel cell, which includes a display unit 15 and a notification unit 16 as warning means, and also includes an operation unit 17 for driving operation.

  The second embodiment shows a system when a user uses a remote control as means for controlling the operation of the fuel cell. That is, the power generation operation / stop of the fuel cell 104 is operated by the operation unit 17 of the remote controller 14, the power generation state of the fuel cell 104 is recognized by the display unit 15, and the notification sound (power generation start is started) according to the driving state by the notification unit 16. And alarms when the power generation is stopped).

  Next, the operation of the freeze prevention operation in the second embodiment will be described.

  When there is no power generation request of the fuel cell 104, the temperature detecting means 10 is not more than a first threshold value (the first threshold value circulates water in the cooling water circulation path 113 and water in the mutual circulation path 117, and heating means) 114 is operated and the anti-freezing operation is started), for example, a temperature of 0 ° C. or less is detected, the cooling water pump 116 and the mutual circulation of the cooling water circulation path 113 are not generated as the anti-freezing operation without generating the power of the fuel cell 104. Each of the pumps 118 in the path 117 is operated to circulate water, and the heating means 114 is operated to transmit the generated heat to the cooling water circulation path 113, the mutual circulation path 117, and the water recovery path 109 to prevent water in each path from freezing. Thus, the control means 13 controls the circulation and heating.

  At this time, an operation state display indicating that the freeze prevention operation is being performed is displayed on the display unit 15 of the remote controller 14 to alert the user.

  Next, when the freeze prevention operation is performed, the temperature detection means 10 operates at a second threshold value equal to or lower than the first threshold value (water freeze in the cooling water circulation path 113 and water circulation in the mutual circulation path 117 and the freeze prevention that operates the heating means 114. When detecting a temperature lower than the lower limit temperature T2) at which freezing can be avoided by driving, the control means 13 detects the detected temperature (Ta) and the elapsed time (TX) from the temperature detection means 10 after the temperature falls below the second threshold T2. To monitor. In FIG. 2, the integration of the elapsed time (TX) of the temperature difference (Td) between the detected temperature (Ta) from the temperature detecting means 10 and the second threshold (T2) from when the value falls below the second threshold (Tx1). When the value (A = Σ (Ta−T2)) reaches Tx2 before reaching the predetermined level (AL: hatched portion between Tx1 and Tx2 in FIG. 2), the drain valve 11. Opening the water drain valve 12 and starting draining from the cooling water circulation path 113, the water recovery path 109, and the mutual circulation path 117 from the display of “Freezing prevention operation” on the display unit 15 of the remote controller 14. The user is alerted by changing the display to “Start draining soon”. Furthermore, after draining starts, the user is alerted by changing the display to “Draining”. Then, after the temperature falls below the lower limit temperature (T2) at which freezing can be avoided in the antifreezing operation that operates the water circulation and the heating means 114, freezing starts from the most cooled part of the water path or the parts having the water path due to the temperature drop. Prior to (Tx3), a warning is given in advance that water is drained before the time of Tx2, and the user is automatically drained by warning that water is being drained during draining. Therefore, it is possible to provide a fuel cell power generator that is safe and convenient without causing a power generation operation by mistake during drainage.

  In the present embodiment, the remote control is used as a means for controlling the operation of the fuel cell. However, it goes without saying that the portable information device terminal can be used, and it is possible for the user to reliably prevent freezing and drain the water. The operation can be warned, and the reliability of the fuel cell power generator can be further improved.

  The fuel cell power generation device according to the present invention also includes at least one of the cooling water circulation path, the water recovery path, and the mutual circulation path before starting freezing even when the temperature becomes lower than the limit temperature (lower limit temperature) at which freeze prevention operation is possible. It is effective for a highly reliable fuel cell power generator that can avoid damage to water paths and parts due to freezing by forcibly draining water in one path.

DESCRIPTION OF SYMBOLS 10 Temperature detection means 11 Drain valve 12 Drain valve 13 Control means 104 Fuel cell 109 Water recovery path 113 Cooling water circulation path 114 Heating means 117 Mutual circulation path

Claims (5)

A fuel cell, a cooling water circulation path for cooling the fuel cell, a water recovery path for recovering water in the reaction product water and the exhaust gas, and a mutual circulation for circulating between the water recovery path and the cooling water circulation path A heating path provided in any one of the path, the cooling water circulation path, the water recovery path, and the mutual circulation path, and a temperature detection means provided at a predetermined position inside the system or a position for detecting an outside air temperature. And when the temperature detecting means detects a temperature below the first threshold in the power generation stop state of the fuel cell, the water in the cooling water circulation path and the water in the mutual circulation path are circulated as a freeze prevention operation, respectively. And when the heating means is operated and the temperature detection means detects a temperature below a second threshold value that is less than or equal to a first threshold value for a predetermined time, the cooling water circulation is performed as a freeze prevention operation. Road and fuel cell power generation system having a control means for operating drainage of water of at least any one of said path of said water recovery path and the cross-circulation path. 2. The fuel cell power generator according to claim 1, further comprising warning means for giving a warning notice that drainage is started. 3. The fuel cell power generator according to claim 2, wherein the warning means is provided in a remote controller or an information equipment terminal that controls the operation of the fuel cell. The fuel cell power generator according to claim 2 or 3, wherein the warning means notifies that water is being drained during draining. The fuel cell power generator according to any one of claims 1 to 4, wherein the temperature detecting means is attached at a position where the water temperature in each path is the lowest.