JP7325222B2 - fuel cell device - Google Patents

Description

The present disclosure relates to fuel cell devices.

A fuel cell device involves water in many processes, and a large amount of water used in these processes is stored in a water tank. Therefore, when the fuel cell device is to be operated or stopped for a long period of time, the inside of the water tank and the inside of the piping through which the water circulates are drained.

Then, before resuming the operation of the fuel cell device, "filling with water" is performed to fill the above-described water tank and piping with water (see Patent Document 1).

A fuel cell device or a hot water storage tank installed in parallel thereto, which constitutes a cogeneration system, usually has an inlet for taking in external water such as tap water, and an outlet for supplying hot water to an external water heater or the like. Tap water introduced from the inlet flows through a large-diameter main pipe through which water mainly used for supplying hot water to the outside flows, and a small-diameter sub-pipe branched from the main pipe. It is distributed to water tanks located throughout the body (see Patent Document 2).

JP 2011-34075 A JP 2015-22864 A

By the way, as described above, the supply of water used for filling and refilling the water tanks arranged in the housing and the supply of hot water to the outside are supplied from a single water source (source pressure). This is done by branching and distributing water pipes.

Therefore, when filling or refilling the water tank and requesting hot water supply to the outside occur at the same time, the source pressure and supply amount (flow rate) of the tap water are preferentially distributed to the hot water supply side, so the water tank is not filled with water. Or, on the replenishing water side, there are cases where the supply of water is insufficient, and filling or refilling with water takes too much time, or filling or refilling with water cannot be completed.

An object of the present disclosure is to provide a fuel cell device capable of completing water supply operations to the water tank, such as filling and refilling water, even when the amount of water supplied to the water tank is low.

The fuel cell device of the present disclosure includes a fuel cell, an external water channel through which water supplied from the outside flows, and a water tank in which water is supplied from the external water channel and necessary for operating the fuel cell is stored. , a water level sensor for detecting the water level of the water tank, and a control device for controlling the operation of the fuel cell.
The control device can execute abnormality determination control for determining an abnormality when the water level sensor does not detect water within a predetermined time after starting water supply to the water tank.
The abnormality determination control includes a first abnormality determination control, a second abnormality determination control that is executed for the same water level as the first abnormality determination control, and a determination time that is set longer than that of the first abnormality determination control; including.

According to the fuel cell device of the present disclosure, it is possible to complete water supply operations to the water tank, such as filling and replenishing water, even in a situation where the amount of water supplied to the water tank is low.

1 is a schematic configuration diagram of a fuel cell device according to an embodiment; FIG. 1 is a perspective view showing the configuration of a fuel cell device inside an exterior case; FIG. 4 is a flowchart of abnormality determination control in the fuel cell device of the embodiment; 4 is a flowchart of another abnormality determination control in the fuel cell device of the embodiment;

Hereinafter, embodiments will be described with reference to the drawings.

FIG. 1 is a block diagram showing the outline of the configuration of the fuel cell device of the embodiment. It should be noted that some general-purpose devices and devices in the fuel cell system are not described in detail and are only given reference numerals in the drawings.

A fuel cell device 100 shown in FIG. The heat energy is recovered by heat exchange and stored as hot water in the heat storage tank 3, and the condensed water generated by condensing the moisture contained in the exhaust gas by heat exchange is used as water for steam reforming of the raw fuel (hereinafter referred to as and a reformed water tank 6 for storing reformed water.

The heat storage tank 3 and the reforming water tank 6 described above are both examples of water tanks for storing water necessary for operating the fuel cell according to the present disclosure. In this embodiment, supply of tap water (water supply) to the heat storage tank 3, which has a relatively large amount of water, will be mainly described.

The fuel cell device 100 includes a raw fuel supply device 11 including a raw fuel pump and a raw fuel channel, etc., and an oxygen-containing gas supply device 12 including an air blower, an oxygen-containing gas channel and the like. It also includes a reformed water supply device 13 including a condensed water flow path C, the reformed water tank 6 described above, a reformed water supply pump, and a reformed water flow path R for continuing water self-sustaining operation.

Furthermore, a heat medium circulation system (first heat cycle) comprising the heat exchanger 2, the heat storage tank 3, the radiator 4, the heat medium circulation pump, and the heat medium circulation flow path HC1 connecting them in an annular fashion is provided. Prepare.

The fuel cell device 100 also includes a second heat exchanger 5 for heating tap water (clean water) to be supplied to the outside, and a high-temperature heat medium taken out of the heat storage tank 3 and circulated. A hot water supply system (second heat cycle) including a heat supply pump, a heat medium circulation flow path HC2, and the like.

The fuel cell device 100 supplies external water such as tap water to the heat storage tank 3 and the reforming water tank 6, which are the water tanks described above, respectively. Have a device.

The water supply device includes water supply valves V ₂ , V ₃ , V ₄ and the like including electromagnetic on-off valves for starting and stopping water supply, and water supply flow paths (pipes) K0 for flowing tap water to each water tank. It consists of K1, K2, etc., and water flowmeters (flow meters) FM1, FM2, FM3, etc. for measuring the flow rate (supply rate) of water flowing through these water supply channels. The water supply channels (pipes) K0, K1, K2 are part of the external water channels of the present disclosure.

Further, as shown in FIG. 1, the fuel cell device 100 includes a hot water supply channel W for supplying hot water to an external water heater 200 or the like, which is indicated by a virtual line (two-dot chain line). This hot water supply channel W is also part of the external water channel of the present disclosure.

The hot water supply channel W passes tap water taken in from an inlet Win disposed on the outer surface of the housing to the second heat exchanger 5 (tap water heat exchanger) of the second heat cycle (heat medium circulation channel HC2). A main pipe (W) is provided for heating via a container) and leading out from an outlet Wout on the outer surface of the housing. Further, the hot water supply flow path W branches from the main pipe (W) to distribute the water used in the water tanks such as the heat storage tank 3 and the reforming water tank 6. K2).

The flow of water through the main pipe (W), that is, the supply of hot water to the water heater 200 is controlled by opening and closing the three-way valve _V1 .

The distribution pipe K0 branched from the main pipe (W) further includes a distribution pipe K1 for flowing water toward the heat storage tank 3 and a distribution pipe K2 for flowing water toward the reforming water tank 6, configured to branch. The flow of water (water supply) to the distribution pipe K0 is controlled by opening and closing the water supply valve _V2 , the flow of water (water supply) to the distribution pipe K1 is controlled by opening and closing the water supply valve _V4 , and the flow to the distribution pipe K2. Water is controlled by water valve _V3 .

Note that the distribution pipe K1 that allows water to flow through the heat storage tank 3 and the distribution pipe K2 that allows water to flow through the reforming water tank 6 are examples of the first flow path in the present disclosure. Further, the water flow meter FM1 and the water flow meter FM3 respectively attached to these distribution pipes K1 and K2 correspond to the first flow rate measuring unit of the present disclosure.

Similarly, the hot water supply channel W that does not branch toward each water tank and flows outward (passes through the housing) is an example of the second channel in the present disclosure. The water flow meter FM2 attached to measure the amount of water passing through corresponds to the second flow rate measuring section of the present disclosure.

The fuel cell device 100 is arranged in a case 30 composed of frames 31 and exterior panels 32 as shown in FIG. In the case 30, around the fuel cell module 1 and each auxiliary device, flow passages, piping, etc., the following control means, a plurality of measuring devices and sensors, other auxiliary devices, etc. are provided. It is

The fuel cell device 100 also includes a control device 20 that controls the operations of the fuel cell module 1 and each auxiliary device, and an indoor operating device for a user or the like to issue instructions to the control device 20. A panel (not shown) and the like are provided.

The control device 20 is connected to a storage device and a display device (both not shown), various components and various sensors that constitute the fuel cell device 100, and controls the entire fuel cell device 100 including these functional units. control and manage; The control device 20 obtains a program stored in an attached storage device (not shown) and executes the program to realize various functions of each part of the fuel cell device 100 .

The fuel cell device 100 also includes a temperature sensor for measuring the temperature of each part, a water level sensor and a water detection device for measuring the water level of each water tank arranged in the housing (case 30). , multiple.

For example, as shown in FIG. 1, a water level sensor WL ₁ is attached to a high water level (high water level or H level) in the heat storage tank 3 in order to measure the water level (water surface height) in the heat storage tank 3. A water level sensor _WL2 is provided at the low water level (low water level or L level).

Similarly, in the reforming water tank 6, a water level sensor WL ₃ is installed at a position corresponding to the high water level (H) inside, and a water level sensor WL ₄ is installed at a position corresponding to the low water level (L). is set. Each of these water level sensors L ₁ , L ₂ , L ₃ , and L ₄ emits a signal (detection signal) that detects water, so that the water level (water surface height) in the tank reaches that position. detect that

When transmitting control signals or various types of information from the control device 20 to other functional units or devices, the control device 20 and other functional units may be connected by wire or wirelessly. The characteristic control of this embodiment performed by the control device 20 will be described later.

Note that, in the embodiment, the control device 20 particularly controls the water supply of tap water (the aforementioned “filling” and “refilling” operations). Also, in each figure, illustration of connection lines connecting the control device 20 and each device and each sensor constituting the fuel cell is omitted.

In the fuel cell device 100 configured as described above, for example, for a long-term stoppage of operation or stoppage of operation, the inside of the water tank and the pipes through which the water circulates have already been drained. , the control in the case where tap water is supplied to the water tank, etc., is performed as follows.

In addition, the control of the fuel cell device described below includes the “filling” operation, in which tap water is supplied to an empty water tank, etc. until it is full, and the water level (water volume) ) to a predetermined high water level. Also, the type of water tank is not limited, and various water tanks that store water necessary for the operation of the fuel cell can be filled with water and replenished with water. In addition, similar control can also be applied to a water filling operation performed by a manager or the like before the first operation after installation of the fuel cell device, such as a test run.

FIG. 3 shows a control flow when the heat storage tank 3 or the reforming water tank 6 of the fuel cell device 100 is "filled with water". In each flow chart, "Yes" indicates "satisfied (affirmative)" and "No" indicates "non-satisfied (negative)" in the determination control.

The chart in FIG. 3 is for the case where the water level sensor attached to the high water level position of the water tank does not detect water for a predetermined time after starting water supply (filling) to the water tank of the fuel cell device. Second, it relates to the control flow of "abnormality determination control" in which the above-mentioned water filling operation ends as an error (ends with an error).

That is, this abnormality determination control is a start trigger that is issued when water supply control (water filling control or water replenishment control) for that water tank is started when the high water level sensor for the target water tank does not detect water. is used as a trigger, it is executed in parallel with water supply control or in addition (add-on) to water supply control.

In addition, in the chart of FIG. 3, descriptions of control "operations" directly related to machines and devices, such as opening and closing of each water supply valve, are omitted.

Also, as will be described later, the abnormality determination control is composed of two blocks of "first abnormality determination control" and "second abnormality determination control" shown in the lower part of the drawing. In the control device, defined values (variables) relating to time such as timers, alarms, watches, etc., and computer flags and the like indicating states are set corresponding to these two types of control respectively.

In the flow of FIG. 3, as described above, the abnormality determination control starts with the "water supply start" (trigger) in water supply control such as water fill control or refill water control [Step 0]. [Step 0] and [Step 1] in the figure are hereinafter simply referred to as [S0], [S1] and the like.

When the control starts, first, in [S1], the control device 30 sets "alarm X" and "alarm Y" as counters for counting "time" for performing the first abnormality determination. set and start the two counters specified.

First, as a situation determination, whether or not the water flow rate of the "first flow path" (one of the external water flow paths) for supplying water to the water tank has decreased. It is checked whether most of the tap water introduced from the outside is diverted to the other external water flow path, that is, the second flow path side, because hot water supply has started.

That is, in [S2], the first flow measuring unit (water flow meter FM1 or water It is determined whether or not the water flow rate F measured by the flow meter FM3) is equal to or less than the "first flow rate (F1)", which is a preset value for each flow path.

Here, in [S2], if the water flow rate F in the first flow rate measurement unit is equal to or lower than the first flow rate F1 [Yes], the control device 30 thereafter determines the "second A series of controls [S3] to [S7] constituting "abnormality determination control" are executed.

In addition, in [S2], if the water flow rate F in the first flow rate measuring unit exceeds the first flow rate F1 [No], the control device 30 will thereafter refer to the right column of the chart in FIG. A series of controls [S8] to [S12] constituting "determination control" are executed.

As will be described later in detail, the count upper limit value Y1 (determination time), which is the set value for issuing alarm Y in the second abnormality determination control, is the set value for issuing alarm X in the first abnormality determination control. It is set longer than the upper limit value X1 (determination time).

In the control flow of the embodiment, even when the amount of water supplied to the water tank or the pressure of water supplied to the water tank is reduced due to an external factor such as hot water supply, an abnormality determination condition with a longer determination time can be applied. As a result, it is possible to avoid and suppress the occurrence of abnormal termination such as interruption of water supply, error notification, and error stop in water supply control as much as possible. In other words, the fuel cell device of the embodiment can complete and complete water supply operations to the water tank, such as filling and replenishing water, even when the amount of water supplied to the water tank is low.

Each abnormality determination control will be described individually.
The second abnormality determination control selects an alarm (timer) at the beginning of control as a block and switches to an appropriate counter suited to the situation. That is, first, in [S3], the control device 20 suspends the time count of the alarm X for a relatively short period (for example, 20 minutes) of the upper limit set value X1, and in [S4], the upper limit set value Y1 is relatively short. Continue counting alarm Y for a long time (eg 120 minutes). In the example, count-up control with an upper limit value is employed, but an alarm or timer system that counts down from a set value (time) may be employed.

Next, in the loop control of [S5] to [S7], the following three points are confirmed or determined.

In [S5], whether or not the water sensor installed at the high water level position of the target water tank, in this example, the water level sensor WL ₁ of the heat storage tank 3, detects water. Check if it reaches the height of

In [S5], if the water level sensor detects water [Yes], it is determined that water supply such as filling or refilling water has been completed, and the control device 20 performs this abnormality determination control, water supply control, etc. Terminate [normal termination].

If the water level sensor does not detect water [No] in [S5], it is determined that water supply such as filling or replenishment of water is not yet completed, and the process proceeds to [S6].

In [S6], in the same procedure as at the start of the control, the flow rate F of the water supply flowing through the first flow path on the water tank side remains low due to the hot water supply, etc., or has recovered due to the suspension of the hot water supply, etc. Check whether or not

In [S6], if the flow rate F of water supply remains low [Yes], the control device 20 continues water supply and alarm Y counting.

In addition, if it is confirmed in [S6] that the flow rate F of the water supply has recovered (increased) [No], as in the above-described [S2], the water supply amount (flow rate F) is large and the water supply is completed in a short time. It shifts to the "first abnormality determination control" applied when completion is expected (to [S8]).

Next, in [S7], the number of hours (integrated value) of the currently activated alarm Y is compared with the above-mentioned upper limit setting value Y1 of the alarm Y, and the number of hours (integrated value) of the alarm Y is calculated. exceeds the upper limit set value Y1 [Yes], the control device 20 judges that this series of water supply operations has timed out, interrupts the water supply, and generates an error to transmit an abnormal end to the outside. After performing the notification, etc., the abnormality determination control, the water supply control, etc. are terminated [error termination].

In [S7], if the number of hours (integrated value) of the alarm Y is equal to or less than the upper limit set value Y1 [No], the control device 20 returns to the confirmation of the water level in [S5] described above. The loop of [S7] is repeated. The above is the second abnormality determination control that is performed when the water supply pressure is low.

Next, in the first abnormality determination control on the right side of the drawing, similarly, at the beginning of control as a block, an alarm (timer) is selected and switched to an appropriate counter according to the situation. That is, first, in [S8], the control device 20 continues to count the time of the alarm Y for a relatively long time (for example, 120 minutes) of the upper limit set value Y1, and in [S9], the time of the relatively short upper limit set value X1. Start timing alarm X (eg, 20 minutes), or resume if paused.

Next, in the loop control of [S10] to [S12], the following three points similar to the above-described second abnormality determination control are confirmed or determined.

In [S10], as in [S5], the water sensor (WL ₁ ) installed at the high water level position of the target water tank detects water, and whether or not the water level reaches the height of this water sensor. or confirm. [S5] Similarly, if the water level sensor detects water and the result is [Yes], the control device 20 terminates the abnormality determination control, the water supply control, etc. [Normal end]. Further, if the water level sensor does not detect water [No], water supply such as filling or replenishing water is not completed, and the process proceeds to [S11].

In [S11], it is checked whether or not the flow rate F of the water supply flowing through the first flow path is decreasing, as at the start of the control. In [S11], if it is confirmed that the flow rate F of the water supply has decreased [Yes], the control device 20 determines that hot water supply or the like has started, the amount of water supply (flow rate F) is small, and it takes time to complete the water supply. The process shifts to the "second abnormality determination control" applied when such a situation is expected (to [S3]). Further, if it is confirmed [No] that the flow rate F of the water supply is maintained at a high level, the control device 20 continues the water supply and the alarm X count.

Next, in [S12], the number of hours (integrated value) of the currently activated alarm X is compared with the above-mentioned upper limit set value X1 of the alarm X, and the number of hours (integrated value) of the alarm X is calculated. exceeds the upper limit set value X1 [Yes], the control device 20 judges that the series of water supply operations has timed out, interrupts the water supply, and issues an error notification or the like to transmit an abnormal end to the outside. After that, the abnormality determination control, the water supply control, etc. are terminated [error termination].

On the other hand, in [S12], if the number of hours (integrated value) of the alarm X is equal to or less than the upper limit set value X1 [No], the control device 20 returns to the confirmation of the water level in [S10] described above, and performs [S10]. ∼ [S12] loop is repeated. The above is the first abnormality determination control that is performed when the water supply pressure is normal or high.

As in the above control flow, the fuel cell device 100 can detect the second abnormality in which the determination time is set longer even when the amount of water supplied to the water tank or the pressure of the water supplied to the water tank is reduced due to an external factor such as hot water supply. By applying the determination condition, it is possible to suppress the occurrence of abnormal termination such as interruption of water supply, error notification, and error stop in water supply control. Therefore, the fuel cell device of the embodiment can complete water supply operations to the water tank, such as filling and refilling with water, even in a situation where the amount of water supplied to the water tank is low.

In the above embodiment, the water level of the water tank is confirmed in [S5] and [S10] of the flow chart by controlling the filling of the heat storage tank 3 with water. Although the water level sensor WL ₁ was used, for example, when the reformed water tank 6 is filled with water, the high water level sensor WL ₃ of the reformed water tank 6 is used to confirm the water level.

In addition, in the control flow of FIG. 3, to confirm the water flow rate on the water supply side and the execution of hot water supply, the first The first water flow rate F measured by the flow rate measurement unit (water flow meter FM1 or water flow meter FM3) was used. It is also possible to use the second water flow rate L by using a second flow rate measuring unit (water flow meter FM2) disposed in the middle of the path (hot water supply path W). However, since the second water flow rate L increases due to hot water supply or the like, the determination criterion is set to be equal to or greater than the predetermined second flow rate L1.

FIG. 4 shows an example of a control flow for selecting one of the two abnormality determination controls, the first abnormality determination control and the second abnormality determination control, based on the amount of water supply (hot water supply) on the water heater 200 side.

The flow chart of FIG. 4 differs from the flow chart of FIG. 3 in [S21] corresponding to [S2] in FIG. 3, [S22] corresponding to [S6], and [S23] corresponding to [S11]. be.

As described above, in these [S21], [S22], and [S23], the amount of water supplied to the heat storage tank 3, the reforming water tank 6, or the like is checked and judged, and , The water flow rate L measured by the second flow rate measuring unit (water flow meter FM2) disposed in the second flow path is equal to or greater than the predetermined set value "second flow rate (L1)". It is possible to determine whether or not hot water supply is to be performed by determining whether or not there is.

In the control flow of FIG. 4, as in the control flow of FIG. 3, it can be confirmed that the amount of water supplied to the water tank or the water supply pressure has decreased due to external factors such as hot water supply. As a result, it is possible to apply an abnormality determination condition in which a longer determination time is set, which is suitable for the situation.

Therefore, in the control flow of FIG. 4, similarly to the control flow of FIG. 3, the occurrence of abnormal termination such as interruption of water supply, error notification, and error stop in water supply control is avoided, and interruption or stop of water supply is suppressed. be able to.

REFERENCE SIGNS LIST 1 fuel cell module 2 heat exchanger 3 heat storage tank 5 second heat exchanger 6 reformed water tank 20 control device 100 fuel cell device W hot water supply channel K distribution pipe

Claims (6)

a fuel cell;
an external water channel through which water supplied from the outside flows;
a water tank supplied with water from the external water channel and storing water necessary for the operation of the fuel cell;
a water level sensor that detects the water level of the water tank;
and a control device for controlling operation of the fuel cell, wherein the control device detects an abnormality when the water level sensor does not detect water within a predetermined time after starting to supply water to the water tank. judgment, it is possible to execute abnormality judgment control,
The abnormality determination control is
first abnormality determination control;
a second abnormality determination control that is executed for the same water level as the first abnormality determination control and is set to a longer determination time than the first abnormality determination control;
A fuel cell device comprising: 2. The fuel cell device according to claim 1, wherein said control device stops said first abnormality determination control when a predetermined first condition regarding said external water flow path is satisfied. The external water channel has a first channel connected to the water tank and a second channel connected to something other than the water tank,
A first flow rate measurement unit that measures the flow rate of the first flow path,
3. The fuel cell device according to claim 2, wherein said first condition is that the measured value of said first flow rate measuring unit is equal to or less than a predetermined first flow rate. The external water channel has a first channel connected to the water tank and a second channel connected to something other than the water tank,
A second flow rate measurement unit that measures the flow rate of the second flow path,
3. The fuel cell device according to claim 2, wherein said first condition is that the measured value of said second flow rate measuring unit is equal to or greater than a predetermined second flow rate. The control device, while the first abnormality determination control is stopped,
5. The fuel cell device according to claim 2, wherein said first abnormality determination control is restarted when said first condition is no longer satisfied. The device includes a heat exchanger for exchanging heat between the exhaust gas of the fuel cell and the heat medium,
6. The water tank according to any one of claims 1 to 5, comprising at least one of a heat storage tank that stores the heat medium and a reformed water tank that stores condensed water generated in the heat exchanger. 1. A fuel cell device according to claim 1.