JP2002305013A - Fuel cell warm-up device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable for the whole fuel cell to be warmed up in early stage by warming up also an anode side together with a cathode side when the fuel cell is warmed up. SOLUTION: This device is provided with an air-supplying means 2 to supply a supply air A to the cathode of the fuel cell 1, and a hydrogen-supplying means 3 to supply a supply hydrogen H to the anode of the fuel cell 1. The air-supply means 2 has an air compressor 21 to pressurize the supply air A and also an air passage to connect the air compressor 21 and the cathode of the fuel cell 1. The hydrogen-supply means 3 has a hydrogen passage to connect an anode- supply device 31 to supply the supply hydrogen H with the anode of the fuel cell 1. A heat exchanger 5 to transmit the heat of the supply air A to the supply hydrogen H is interposed between the air passage and the hydrogen passage.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a fuel cell warm-up device for warming up a fuel cell.

[0002]

2. Description of the Related Art In recent years, as a power source of an electric vehicle,
Attention has been focused on clean and energy-efficient fuel cells. In this fuel cell, oxygen is supplied to the cathode side and hydrogen is supplied to the anode side, and electricity is generated by a reaction between hydrogen and oxygen. In order to supply oxygen to the cathode side, air containing oxygen is supplied to the fuel cell by, for example, a compressor. At this time, the air is heated by the pressure of the compressor. The fuel cell has a predetermined temperature (80 to 90 in the case of the fixed polymer type).
C), but the air pressurized by the compressor rises to, for example, about 120 ° C. If air at this temperature is supplied to the fuel cell as it is, efficient power generation cannot be realized, so air before being supplied to the fuel cell is passed through a radiator, cooled to a predetermined temperature, and then supplied to the fuel cell. I have.

[0003] By the way, when starting the fuel cell,
The fuel cell is also cold, lower than the temperature at which efficient power generation is achieved. Therefore, it is necessary to quickly heat (warm up) the fuel cell to a predetermined temperature when starting the fuel cell. In particular, when the fuel cell is mounted on an electric vehicle, it is necessary to warm up the vehicle more quickly.

[0004]

Meanwhile, when warming up the fuel cell, it is conceivable that high-temperature air warmed by the compressor is directly sent to the fuel cell. By supplying hot air to the fuel cell, the fuel cell is quickly warmed up.

[0005] However, even if high-temperature air is sent to the fuel cell, it is sent only to the cathode side of the fuel cell. Therefore, the anode side of the fuel cell is warmed by transferring the heat of the cathode side via the membrane of the fuel cell. Therefore, the warming-up of the anode side is slower than that of the cathode side, and as a result, there is a problem that the warming-up of the entire fuel cell cannot be performed early.

Accordingly, an object of the present invention is to warm up the fuel cell as well as the anode side as well as the cathode side so that the entire fuel cell can be warmed up at an early stage.

[0007]

According to a first aspect of the present invention, there is provided an air supply unit for supplying air to a cathode of a fuel cell, and an anode for the fuel cell. A hydrogen supply unit that supplies hydrogen to the air supply unit, the air supply unit includes a compressor that pumps the air, and an air passage that connects the compressor and a cathode of the fuel cell. A heat exchanger that has a hydrogen passage connecting a hydrogen supply source that supplies the hydrogen and an anode electrode of the fuel cell, and that transfers heat of the air to the hydrogen between the air passage and the hydrogen passage. A fuel cell warm-up device, wherein a fuel cell warm-up device is interposed. It is.

According to the first aspect of the present invention, the heat of the air is transferred between the air passage for supplying air to the cathode side of the fuel cell and the hydrogen passage for supplying hydrogen to the anode side. A heat exchanger that transmits the heat is interposed. The temperature of the air flowing through the air passage is increased by adiabatic compression of the compressor. Therefore, the heat of the air can be transferred to the hydrogen via the heat exchanger to raise the temperature of the hydrogen. By raising the temperature of hydrogen, the anode side of the fuel cell can also be quickly warmed up, and the warming-up of the entire fuel cell can be completed quickly.

According to a second aspect of the present invention, the air passage includes:
The fuel cell includes a main passage and a bypass passage, and a radiator for cooling the air is provided in the main passage, and a passage through which the air passes is switched between the main passage and the bypass passage. The fuel cell warm-up device according to claim 1, further comprising a calorie adjusting means for adjusting a calorific value of air supplied to the fuel cell.

In the invention according to claim 2, the air passage has:
It has a main passage provided with a radiator and a bypass passage provided around the radiator. The passage through which the air passes is switched between the main passage and the bypass passage, and the calorific value of the air supplied to the fuel cell is adjusted by the calorie adjusting means. Therefore, air and hydrogen at a temperature suitable for the fuel cell can be supplied to the fuel cell.

According to a third aspect of the present invention, there is provided a fuel cell warm-up apparatus according to the second aspect, further comprising a control device for controlling the heat amount adjusting means in accordance with a warm-up state of the fuel cell. Machine device.

In the invention according to claim 3, the passage through which the air flows is switched between the main passage and the bypass passage by the calorific value adjusting means in accordance with the warm-up state of the fuel cell.
The amount of heat of the air supplied to the fuel cell is adjusted. Therefore, air and hydrogen at appropriate temperatures can be supplied to the fuel cell according to the warm-up state of the fuel cell. The warm-up state of the fuel cell can be specified by, for example, the temperature of the exhaust air discharged from the fuel cell.

According to a fourth aspect of the present invention, there is provided a control device for controlling the heat amount adjusting means based on an outside air temperature around the fuel cell.
3. The fuel cell warm-up device according to item 1.

In raising the temperature of the air supplied to the fuel cell to a suitable temperature, it is necessary to increase the amount of heat when the outside air temperature is low. Conversely, when the outside air temperature is high, the amount of heat need be small. Therefore, in the invention according to claim 4, the calorie adjusting means is controlled based on the outside air temperature. Specifically, when the outside air temperature is low, the flow rate of the air flowing through the bypass passage is increased, and when the outside air temperature is high, the flow rate of the air flowing through the main passage is increased. Thus, it is possible to supply air at a suitable temperature to the fuel cell.

According to a fifth aspect of the present invention, there is provided a fuel cell warm-up device according to the second aspect, further comprising a control device for controlling the heat amount adjusting means in accordance with the amount of power generated by the fuel cell. It is.

If the amount of power generated by the fuel cell is large, the amount of hydrogen consumed also increases. Therefore, it is preferable to increase or decrease the calorific value of air in accordance with an increase or decrease in the amount of hydrogen consumption. Therefore, in the claims, the calorific value adjusting means is controlled according to the amount of power generated by the fuel cell. Specifically, when the amount of power generated by the fuel cell is large, the amount of hydrogen consumption is also large. Therefore, in order to apply heat to the large amount of hydrogen, the amount of heat of air is increased by increasing the flow rate of air flowing through the bypass passage. Conversely, when the amount of power generated by the fuel cell is small, the amount of hydrogen consumed is small, so that the amount of hydrogen that gives heat is also small. Therefore, the amount of heat applied to the air can be reduced, so that the amount of air flowing through the main passage is increased. Thus, air and hydrogen at a suitable temperature can be supplied to the fuel cell.

According to a sixth aspect of the present invention, in the first aspect of the present invention, a throttle whose opening is adjustable is provided in the bypass passage.
It is a fuel cell warm-up device described in the paragraph.

In the invention according to claim 6, a throttle valve whose opening degree can be adjusted is provided in the bypass passage.
For this reason, the width (diameter) of the pipe of the bypass passage can be reduced or increased. Since the pressure on the outlet side of the compressor can be increased by increasing the width of the pipe of the bypass passage, the temperature of the air can be controlled by the width of the pipe of the bypass passage. Thus, by adjusting the width (diameter) of the pipe of the bypass passage, the air and hydrogen supplied to the fuel cell can be controlled to appropriate temperatures.

[0019]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a fuel cell warm-up device according to an embodiment of the present invention will be described in detail with reference to the drawings.

[First Embodiment] First, a fuel cell warm-up device according to a first embodiment will be described. In the drawings referred to in the first embodiment, FIG. 1 is an overall configuration diagram of a fuel cell system including a fuel cell warm-up device of the first embodiment, and FIG. 2 is an explanatory diagram schematically illustrating the configuration of a fuel cell. is there.

The fuel cell system FCS shown in FIG. 1 comprises a fuel cell 1, an air supply device 2, a hydrogen supply device 3, a control device 4, an anode-cathode heat exchanger (hereinafter referred to as "heat exchanger") 5, and the like. This is a power generation system having a fuel cell 1 as a core. The fuel cell warm-up device GS (GS
1) includes an air supply device 2 and a control device 4. It is assumed that the fuel cell system FCS according to the present embodiment is mounted on an automobile (fuel cell electric vehicle).

As shown in FIG. 2, the fuel cell 1 is divided into a cathode side (oxygen side) and an anode side (hydrogen side) with an electrolyte membrane 1c interposed therebetween. An electrode containing a catalyst is provided to form a cathode electrode 1b and an anode electrode 1d. As the electrolyte membrane 1c, a solid polymer membrane, for example, a perfluorocarbon sulfonic acid membrane which is a proton exchange membrane is used. This electrolyte membrane 1c
Has a large number of proton exchange groups in a solid polymer, shows a low specific resistance of 20 Ω-proton or less at room temperature by being saturated with water, and functions as a proton conductive electrolyte.

Outside the cathode electrode 1b, there is provided a cathode electrode side gas passage 1a through which supply air A as an oxidizing gas flows through the cathode electrode 1b.
Outside the electrode d, an anode electrode-side gas passage 1e through which the supply hydrogen H as a fuel gas flows to the anode electrode 1d is provided. The inlet and outlet of the cathode-side gas passage 1a are connected to the air supply device 2, and the anode-side gas passage 1e
Are connected to a hydrogen supply device 3.
The configuration of the fuel cell 1 in FIG. 2 is schematically illustrated as one single cell, but the actual fuel cell 1 is configured as a stacked body in which about 200 single cells are stacked. . Further, the fuel cell 1 has a cooling device (not shown) for cooling the fuel cell 1 because the fuel cell 1 generates heat due to an electrochemical reaction during power generation.

In the fuel cell 1, supply air A flows through the cathode-side gas passage 1a, and the anode-side gas passage 1a
When the supply hydrogen H is supplied to e, the hydrogen is ionized by the catalytic action at the anode electrode 1d to generate protons, and the generated protons move through the electrolyte membrane 1c and reach the cathode electrode 1b. Then, the protons reaching the cathode electrode 1b react with oxygen ions of the oxygen of the supply air A to generate water. The supply air A containing the generated water and unused oxygen is discharged from the outlet on the cathode side of the fuel cell 1 as the discharge air Ae (the discharge air Ae contains a large amount of water). At the anode electrode 1d, electrons e- are generated when hydrogen is ionized, and the generated electrons e-
Is a cathode electrode 1 via an external load M such as a motor.
reaches b.

Next, as shown in FIG.
Has an air compressor 21, a bypass valve 22, a radiator 23, a throttle valve 24, a cathode humidifier 25, and a cathode back pressure valve 26, which are the compressors of the present invention. The radiator 23 includes the bypass valve 22 and the cathode humidifier 2.
5 is provided in the main passage W1 between the radiators 2
3 is provided with a radiator 23A for cooling the cooling water circulated to cool the supply air A. The throttle valve 24 is provided in a bypass passage W <b> 2 formed around the radiator 23, and the heat exchanger 5 is interposed between the radiator 23 and the cathode humidifier 25. Therefore, the supply gas passing through the bypass passage W2 is
3 does not pass. Here, the cross-sectional area of the bypass passage W2 is smaller than the cross-sectional area of the main passage W1. Therefore, the supply air A is supplied to the bypass passage W2.
, The pressure on the outlet side of the air compressor 21 is higher than when flowing through the main passage W1. As a result, the supply air A is heated to a higher temperature. Here, specifically,
The cross-sectional area of the bypass passage W2 is desirably set to half or less of the cross-sectional area of the main passage W1. In addition, the air supply device 2 has temperature sensors T1 to T4 for detecting the temperature of the supply air A and the cooling water supplied to the radiator 23.

The air compressor 21 is a compressor including a supercharger (not shown) and a motor for driving the supercharger. The air compressor 21 removes dust and the like through an air cleaner (not shown), and adiabatically compresses the supply air A used as the oxidant gas in the fuel cell 1 and sends it to the fuel cell. During the adiabatic compression, the supply air A is heated. The supply air A heated in this way contributes to the warm-up of the fuel cell 1.

The bypass valve 22 is composed of a flow path switching valve, and switches a passage through which the supply air A flows between the main passage W1 and the bypass passage W2 based on a switching signal output from the control device 4. Is determined whether the supply air A is to be flowed.

The radiator 23 is provided with a cooling water flow path through which cooling water flows. By exchanging heat with the cooling water, the air compressor 21 is operated during normal operation of the fuel cell 1.
Is cooled. A radiator 23A is connected to the radiator 23. The radiator 23A cools the supply water A by the radiator 23 and cools the cooling water heated by the heat with a cooling fan, for example. The temperature of supply air A supplied from air compressor 21 during normal operation of fuel cell 1 is normally 12
Although it is about 0 ° C., the fuel cell 1 is operated at a temperature of about 80 to 90 ° C. Therefore, the supply air A is 60 to 75
It is cooled to about ° C and introduced into the fuel cell 1.

The throttle valve 24 is an opening adjustment valve whose opening is adjustable. By adjusting the opening, the diameter of a part of the bypass passage W2 through which the supply air A passes can be reduced. It has become.

The cathode humidifier 25 is of a fuel cell exhaust gas supply type, for example, a large number, specifically 500
A hollow fiber membrane bundle in which zero hollow fiber membranes are bundled is housed in a housing, and supply air A passes through the hollow fiber membrane, and discharge air A passes inside the housing and outside the hollow fiber membrane.
e passes. In the fuel cell 1, water is generated along with power generation, and the discharged air Ae contains a large amount of water.
The water is exchanged with the supply air A to humidify the supply air A. The cathode humidifier 25 includes a fuel cell exhaust gas supply type, a venturi (not shown), a water storage tank, a siphon pipe connecting the venturi and the water storage tank (a type of carburetor), and the like. A known device such as a device for sucking up and spraying the humidifying water stored in the water storage tank by the Venturi effect and humidifying the supply air A may be used.

The cathode back pressure valve 26 is composed of a butterfly valve (not shown) and a stepping motor for driving the same. Control by decreasing / increasing. Incidentally, when the opening degree of the cathode back pressure valve 26 is reduced, the discharge pressure of the fuel cell 1 increases, and the temperature rise of the discharge air Ae increases accordingly. Further, when the opening degree of the cathode back pressure valve 26 is increased, the discharge pressure of the fuel cell 1 decreases, and the temperature rise of the discharge air Ae decreases correspondingly.

Each of the temperature sensors T1 to T4 is composed of a thermistor or the like. Among them, the temperature sensor T1
Detects the temperature of the supply air A at the cathode-side entrance of the fuel cell 1. The temperature sensor T2 detects the temperature of the exhaust air Ae at the cathode outlet of the fuel cell. Further, the temperature sensor T3 is connected to the radiator 23A.
The temperature of the cooling water supplied to the radiator 23 from is detected. Then, the temperature sensor T4 detects the temperature of the supply air A supplied to the heat exchanger 5. These temperature sensors T1 to T4 output the detected signals respectively to the control device 4.
Send to The warm-up state of the fuel cell 1 is determined based on the temperature T2 of the exhaust air Ae detected by the temperature sensor T2. Further, the outside air temperature is determined based on the temperature T3 of the cooling water in the radiator 23 detected by the temperature sensor T3.

Further, as shown in FIG.
Comprises an anode supply device 31, an anode circulation device 32, an anode humidifier 33, and the like.

The anode supply device 31 includes, for example, a hydrogen gas cylinder and a regulator. The hydrogen gas cylinder is composed of a high-pressure hydrogen container (not shown),
The supply hydrogen H introduced to the anode electrode side is stored. The supply hydrogen H to be stored is pure hydrogen, and the pressure is 15-20M.
PaG (150-200 kg / cm2G). The hydrogen gas cylinder contains a hydrogen storage alloy and has a pressure of 1 MPaG (10 MPa).
It may be a hydrogen storage alloy type that stores hydrogen at a pressure of about kg / cm2G). The regulator is a pressure control valve composed of a diaphragm, a pressure adjusting spring, and the like (not shown), and reduces the supply hydrogen H stored at a high pressure to a predetermined pressure so that the supply hydrogen H can be used at a constant pressure.

The anode circulation device 32 comprises, for example, a hydrogen circulation pump. This hydrogen circulation pump is constituted by an ejector or the like (not shown), and utilizes the flow of the supply hydrogen H toward the anode electrode side of the fuel cell 1 to supply hydrogen H used as fuel gas in the fuel cell 1, that is, Discharged hydrogen He discharged from the anode side of the fuel cell 1 is sucked and circulated. The reason why the discharged hydrogen He is circulated is that the supply hydrogen H is pure hydrogen stored in the hydrogen gas cylinder in the anode supply device 31.

Next, the control device 4 includes a CPU (not shown)
It comprises a memory, an input / output interface, an A / D converter, a bus, etc., and controls the fuel cell system FCS as a whole and controls the temperature of the supply air A supplied to the fuel cell 1. The control device 4 receives the detection signals output from the temperature sensors T1 to T4 as described above. Further, the control device 4 includes an air compressor 21, a bypass valve 22,
Control signals for the throttle valve 24 and the cathode back pressure valve 26 are transmitted. In the present embodiment, the control device 4 switches the bypass valve 22 and adjusts the throttle opening of the throttle valve 24. Thus, the passage through which the supply air A supplied from the air compressor 21 flows is divided into the main passage W1 and the bypass passage W2.
Switch between. When flowing through the bypass passage W2, the opening degree of the throttle valve 24 is adjusted to adjust the temperature of the supply air A. Therefore, the bypass valve 22 and the throttle valve 24 constitute the heat amount adjusting means of the present invention.

The heat exchanger 5 includes an air passage connecting the air compressor 21 and the cathode of the fuel cell 1 and an anode supply device 3.
1 and a hydrogen passage connecting the anode electrode of the fuel cell 1. This heat exchanger 5 is provided with supply air A
And a hydrogen flow path through which the supply hydrogen H flows, so that the heat of the supply air A flowing through the air flow path is transmitted to the supply hydrogen H flowing through the hydrogen flow path. I have.

Next, an example of the operation of the fuel cell warm-up device GS1 when starting the fuel cell 1 according to the first embodiment will be described.
This will be described with reference to FIG. 3 (see FIG. 1 as appropriate).

FIG. 3 is a flowchart showing a control flow of the fuel cell warm-up device. Note that the target temperature of the supply air A supplied to the fuel cell 1 is 65 ° C to 80 ° C.

When the ignition switch is turned on when starting the fuel cell (S1), the air compressor 21 is driven. When the air compressor 21 is driven, the temperature sensors T1,
The temperature of the supply air A at the inlet of the fuel cell 1 and the temperature of the exhaust air Ae at the outlet of the fuel cell 1 are detected by T2 (S2). Subsequently, it is determined whether the temperature T2 of the exhaust air Ae detected by the temperature sensor T2 exceeds 15 ° C., and the supply air A detected by the temperature sensor T1 is determined.
It is determined whether the temperature T2 of the discharged air is higher than the temperature T1 of (S3). If the temperature of the exhaust air Ae exceeds 15 ° C., it indicates that the fuel cell 1 has been warmed, and it can be determined that warming up of the fuel cell 1 is not particularly necessary. On the other hand, when the temperature of the exhaust air Ae is higher than the temperature of the supply air A, the fuel cell 1 is also considered to be warmed up, so that it can be determined that warming up of the fuel cell 1 is unnecessary. Therefore, when the temperature of the exhaust air Ae exceeds 15 ° C. or the temperature T2 of the exhaust air Ae is higher than the temperature T1 of the supply air A, the fuel cell 1 does not need to be warmed up. Judge. Then, the idling operation of the fuel cell 1 is started while the driving of the air compressor 21 is continued (S
5). The process up to this point is when the ignition switch
This is performed immediately after setting N.

If it is determined in step S4 that the temperature T2 of the exhaust air Ae is equal to or lower than 15 ° C. and the temperature of the exhaust air Ae is equal to or lower than the temperature T1 of the supply air A,
The temperature of the cooling water in the radiator 23 is detected by the temperature sensor T3 (S6). Now, the temperature of the cooling water is considered to be substantially equal to the outside air temperature. However, if the temperature of the cooling water exceeds 15 ° C., it is considered that the fuel cell 1 does not need to be warmed up. Therefore,
It is determined whether the temperature T3 of the cooling water exceeds 15 ° C. (S7). As a result, when the temperature T3 of the cooling water is higher than 15 ° C., it can be determined that the fuel cell 1 does not need to be warmed up. The operation is started (S5). If it is determined in step S7 that the temperature T3 of the cooling water is equal to or lower than 15 ° C., the bypass valve 22 is turned on (S8), and a low-temperature start mode is entered (S9). The supplied air A flows through the bypass passage W2. When the bypass valve 22 is turned on, the supply air A passes through the bypass passage W2, and when the bypass valve 22 is turned off, the passage is switched such that the supply air A flows through the main passage W1. When the supply air A flows through the bypass passage W2, the supply air A bypasses the radiator 23 and is supplied to the fuel cell 1. Since the supply air A supplied around the radiator 23 is not cooled by the radiator 23, the air heated by the air compressor 21 can be supplied to the fuel cell 1 as it is.

Here, the supply air A supplied to the fuel cell
Pass through the heat exchanger 5. In this heat exchanger 5,
The supply hydrogen H supplied to the anode side of the fuel cell 1 is also flowing. Now, this supply hydrogen H is almost the same temperature as the supply air A before being heated by the air compressor 21,
The temperature is lower than the warmed supply air A. Also, usually
The flow rate of the supply hydrogen H is much smaller than the flow rate of the supply air A. When both the supply air A and the supply hydrogen H pass through the heat exchanger 5, the heat of the supply air A is transmitted to the supply hydrogen H, and the supply hydrogen H is warmed to have substantially the same temperature as the supply air A. . For this reason, the supply air A is required to have a heat quantity for warming the supply hydrogen H, and the supply air A is heated to a temperature higher than 65 to 80 ° C. which is the temperature supplied to the fuel cell 1. Can be

In this way, the supply air A is supplied to the cathode side of the fuel cell 1 while the supply air A is heated by the air compressor 21 and the supply hydrogen A is heated by the heat of the supply air A. By supplying the fuel to the anode, the fuel cell 1 can be uniformly warmed up as a whole. Therefore, the time for warming up the fuel cell 1 until the fuel cell 1 can exhibit a predetermined power generation capacity can be shortened. Thus, the fuel cell 1 is quickly warmed up. In the low-temperature start mode, the air compressor 21 is operated with electric power (for example, 5 kW) larger than normal idling electric power (for example, 500 W).
The amount of heating by the adiabatic compression of is increased. Further, the opening degree of the throttle valve 24 is appropriately determined, for example, based on the temperature of the supply air A immediately before being supplied to the fuel cell 1 detected by the temperature sensor T1.

During the low temperature start mode, the temperature T1 of the supply air A immediately before being supplied to the fuel cell 1 is detected by the temperature sensor T1, and the temperature of the exhaust air Ae discharged from the fuel cell 1 is detected by the temperature sensor T2. It is detected (S10). Then, a supply air rise temperature ΔT1 compared with the previous temperature of the supply air A supplied to the fuel cell 1 and a discharge air rise temperature ΔT2 compared with the previous temperature of the exhaust air Ae discharged from the fuel cell 1 are calculated. . Then, it is determined whether each of the supply air rise temperature ΔT1 and the discharge air rise temperature ΔT2 exceeds 0 ° C. (S11). As a result, when either the supply air rise temperature ΔT1 or the discharge air rise temperature ΔT2 is equal to or lower than 0 ° C., the process returns to step S9 and the low temperature start mode is continued.

When the supply air rise temperature ΔT1 and the discharge air rise temperature ΔT2 both exceed 0 ° C., the temperature T3 of the cooling water of the radiator 23 is detected by the temperature sensor T3 (S12). Then, it is determined whether the temperature T3 of the cooling water is lower than 15 ° C. (S13). As a result, when the water temperature T3 of the cooling water is lower than 15 ° C., the radiator 23 has not been warmed up yet. Therefore, when the supply air A flows through the radiator 23, the supply air A cools. For this reason, after the low temperature start mode is released (S14), the throttle of the throttle valve 24 is fully opened to bypass the radiator 23 (S15), and the supply air A is entirely flown into the bypass passage W2. Then, the idling operation of the fuel cell 1 is started while the driving of the air compressor 21 is continued (S16). Air compressor 2 at this time
1 is operated with an electric power of 500 W, for example.

Then, the temperature T3 of the cooling water of the radiator 23 is detected (S17), and it is determined whether the temperature T3 of the cooling water is lower than 15 ° C. (S18). As a result, when the temperature T3 of the cooling water is lower than 15 ° C., the process returns to step S16, and the idle operation of the fuel cell 1 is continued. Thus,
Feedback control is performed until the temperature of the cooling water becomes 15 ° C. or more, and the same operation is repeated until the temperature of the cooling water T3 becomes 15 ° C. or more. When the temperature T3 of the cooling water is equal to or higher than 15 ° C., it can be determined that the radiator 23 is no longer in a cooled state, and the process proceeds to step S19 shown in FIG.

On the other hand, in step S13, the radiator 2
When it is determined that the temperature T3 of the cooling water of No. 3 is equal to or higher than 15 ° C., since the radiator 23 is not in a cooled state, the process directly proceeds to step S19.

In step 19, it is determined whether or not the fuel cell 1 is in the low temperature start mode. As a result of the low temperature judgment,
If not in the start mode, the process skips step S20 and proceeds to step S21. On the other hand, if it is determined in step S19 that the vehicle is in the low-temperature start mode, the start mode is released (S20). When the low-temperature start mode is released, the bypass valve 22 is turned off, and the air supplied from the air compressor 21 flows through the main passage W1. The supply air A flowing through the main passage W1 is supplied to the fuel cell 1 after the temperature is adjusted to a predetermined temperature by the radiator 23. Then, the driving of the air compressor 21 is continued, and the idle operation of the fuel cell 1 is performed (S22). Then, the warm-up of the fuel cell 1 ends (S23).

As described above, in the present embodiment, the supply air A supplied to the cathode side of the fuel cell 1 and the supply hydrogen H supplied to the anode side of the fuel cell 1 are heated by the air compressor 21, respectively. Pass through 5. In the heat exchanger 5, the heat of the supply air A is transmitted to the supply hydrogen, and the supply hydrogen H is heated. Therefore, the anode side of the fuel cell 1 can be directly warmed up without passing through the cathode side of the fuel cell 1. Therefore, it is possible to quickly warm up the fuel cell 1 as a whole.

When judging the completion of the warm-up of the fuel cell 1, the temperature of the exhaust air Ae discharged from the fuel cell 1 and a temperature sensor (not shown) provided on the inlet side of the air compressor 21, for example, are used. It is also possible to measure the outside air temperature and control the bypass valve 22 based on the outside air temperature. When the outside air temperature is low, it is necessary to increase the amount of heat applied to the air in order to raise the temperature of the air until the temperature becomes suitable for the fuel cell 1. Therefore, when the outside air temperature is low, control is performed so as to increase the flow rate of the supply air A flowing through the bypass passage W2. Conversely, when the outside air temperature is high, the flow rate of the supply air A flowing through the main passage W1 is increased. Thus, the temperature of the supply air A can be appropriately adjusted.

The warm-up process during normal running in this embodiment will be described. Since the warm-up process during the normal running is performed in the fuel cell warm-up device GS1 shown in FIG. 1, reference is made to FIG. FIG. 6 (a)
5 is a flowchart for explaining a warm-up process in a normal state. As shown in FIG. 6A, when the fuel cell 1 is in the normal mode (S30), the temperature sensor T4
Detects the temperature T4 of the supply air A supplied to the heat exchanger 5, and determines whether the temperature of the supply air A is lower than 60 ° C. (S31). When the fuel cell 1 is in the normal mode, the bypass valve 22 is turned off in order to cool the supply air A by the radiator 23, and the supply air A is supplied to the main passage W1.
Is flowing. Here, when the temperature of the supply air A supplied to the heat exchanger 5 is lower than 60 ° C., the appropriate temperature range of the supply air for supplying the fuel cell 1 is 65 to 8.
The supply air A at a temperature within the range of 0 ° C. cannot be supplied to the fuel cell 1. On the other hand, in step S31, when the temperature T4 of the supply air A is equal to or higher than 60 ° C., the supply air A in the temperature range appropriate for the fuel cell 1 can be supplied to the fuel cell 1. Therefore, the bypass valve 22 is kept OFF (S32), and the supply air A
Is kept flowing through the main passage W1, and the process is terminated.

When the temperature T4 of the supply air A detected by the temperature sensor T4 is lower than 60 ° C., it is necessary to supply the warm supply air A to the fuel cell 1, so that the bypass valve 22 is turned on. (S33), the supply air A flows through the bypass passage W2. The supply air A flowing through the bypass passage W2 is supplied to the fuel cell 1 while bypassing the radiator 23, so that the supply air A is supplied to the fuel cell 1 while being warm. Also,
When the supply air A flows through the bypass passage W2, the pressure at the outlet side of the air compressor 21 is adjusted by a throttle valve 24 provided in the bypass passage W2. At this time, the opening degree of the throttle valve 24 is determined by a function f (T4) using the temperature T4 of the supply air A immediately before the inlet of the heat exchanger 5 as a parameter (S34). The function used at this time is shown in FIG.
Shown in As shown in FIG. 6B, in a region where the temperature T4 of the supply air A immediately before the heat exchanger 5 is lower than 60 ° C., the lower the temperature T4 of the supply air A, the more the throttle opening of the throttle valve 24 decreases. Squeeze (reduce). By reducing the throttle opening of the throttle valve 24, the pressure of the supply air A on the outlet side of the air compressor 21 can be increased, and the supply air A can be heated to a higher temperature. Therefore, the temperature of the supply air A supplied to the fuel cell 1 can be increased.

Then, as the temperature T3 of the supply air A approaches 60 ° C., the throttle opening of the throttle valve 24 is opened (increased). By opening the throttle opening of the throttle valve 24,
The pressure of the supply air A on the outlet side of the air compressor 21 decreases, and the amount of increase in the temperature of the supply air A decreases.
Therefore, the supply air A supplied to the fuel cell 1 can be controlled so as to have an appropriate temperature.

By performing such control, the warm-up process of the fuel cell in the normal state is terminated (S35). Thus, the fuel cell 1 can be warmed up even during the normal operation of the fuel cell 1.

[Second Embodiment] Next, a second embodiment of the present invention will be described. Elements and members that are the same as those in the first embodiment are given the same reference numerals, and descriptions thereof are omitted. FIG. 7 is an overall configuration diagram of a fuel cell system including the fuel cell warm-up device according to the second embodiment.

As shown in FIG. 7, the fuel cell warm-up device GS2 of the second embodiment is different from the heat exchanger 5 of the first embodiment shown in FIG. 4
2 is provided, which is different from the first embodiment.
In the second embodiment, these common pipes 41 and 42 serve as heat exchangers that transfer the heat of the supply air to the supply hydrogen. In the second embodiment, the throttle valve 24 is not provided.

In the second embodiment, the supply air A supplied from the air compressor 21 is introduced into the first common pipe 41 via the radiator 23. The supply air A that has exited the first common pipe 41 passes through the cathode humidifier 25 and is introduced into the second common pipe 42. The supply air A flowing out of the second common pipe 42 is supplied to the cathode side of the fuel cell 1. The exhaust air Ae discharged from the cathode side of the fuel cell 1 is
It is discharged via the same route as in the first embodiment.

On the other hand, the supply hydrogen H supplied from the anode supply device 31 is introduced into the first common pipe 41 via the anode circulation device 32. Here, a cross-sectional view of the first common pipe 41 is shown in FIG. As shown in FIG. 8, the first common pipe 41 has a double pipe structure, and the inside of the inner pipe 41A is a hydrogen flow path HF through which the supplied hydrogen passes. Further, the outside of the inner tube 41A and the inside of the outer tube 41B constitute an air flow path AF through which supply air passes. With such a simple double pipe structure, the supply air A and the supply hydrogen flow in the same direction in the air flow path AF and the hydrogen flow path HF, respectively, so that the heat of the supply air A is supplied. It is transmitted to hydrogen H. In the present embodiment, the supply air A and the supply hydrogen flow in parallel, but of course, they may flow in opposition.

The supply hydrogen H flowing out of the first common pipe 41 passes through the anode humidifier 33 and is introduced into the second common pipe 42. Like the first common pipe, the second common pipe 42 includes an inner pipe 42A and an outer pipe 42B as shown in FIG. 8, and a hydrogen flow path HF through which the supply hydrogen H flows is formed inside the inner pipe 42A. An air passage AF through which supply air flows is formed outside the inner tube 42A and inside the outer tube 42B. Thus, heat is transmitted from the supply air to the supply hydrogen between the supply air and the supply hydrogen flowing through the respective flow paths.

The supply air flowing out of the second common pipe 42 is supplied to the anode side of the fuel cell 1. The He discharged from the anode side of the fuel cell 1 is introduced into the anode circulation device 32 and is recycled.

The fuel cell warm-up device GS2 according to the present embodiment
In the same manner as in the first embodiment, the bypass valve 22 and the cathode back pressure valve 26 are controlled based on each temperature signal output from the temperature sensors T1 to T4. Therefore, by supplying the supply air A and the supply hydrogen H at appropriate temperatures to the fuel cell 1, the fuel cell 1 can be quickly warmed up.

In this embodiment, the common pipe 4
Since the heat of the supply air A is transmitted to the supply hydrogen H using the heat exchangers 1 and 42 to warm the supply hydrogen H, the entire apparatus is compared with the case where the heat exchanger 5 is used as in the first embodiment. Can be reduced in size.

The present invention can be widely modified without being limited to the above-described embodiments. For example, in each of the above embodiments, the control of the bypass valve and the throttle valve is performed based on the temperature of the supply air supplied to the fuel cell 1 and the temperature of the cooling water of the cooler in the radiator. On the other hand, for example, based on the amount of power generated from the fuel cell, the state of the fuel cell can be grasped, and the temperature of supply air and supply hydrogen supplied to the fuel cell can be controlled. Specifically, for example, when the amount of power generation of the fuel cell increases, the amount of hydrogen consumption also increases accordingly.
Therefore, the amount of hydrogen supplied to the fuel cell also increases, and in order to apply heat to this much hydrogen, the flow rate of air flowing through the bypass passage is increased to increase the amount of heat of air. Conversely, when the amount of power generated by the fuel cell is small, the amount of hydrogen consumed is small, so that the amount of hydrogen that gives heat is also small. Therefore, the amount of heat applied to the air can be reduced, so that the amount of air flowing through the main passage is increased. Thus, air and hydrogen at a suitable temperature can be supplied to the fuel cell. The amount of power generated by the fuel cell can be detected by, for example, an ECU (not shown).

In the above embodiment, a bypass valve for switching between the main passage and the bypass passage is used as the heat amount adjusting means. However, for example, a flow regulating valve for adjusting the amount of air flowing through the main passage and the bypass passage may be used. it can.

Although the hydrogen supply device is configured to supply hydrogen from the hydrogen tank to the fuel cell, a liquid fuel such as methanol is reformed by a reformer to produce a hydrogen-rich fuel gas. May be supplied to the fuel cell.

[0066]

According to the first aspect of the present invention described above, the heat of the air can be transferred to the hydrogen via the heat exchanger to raise the temperature of the hydrogen. By raising the temperature of hydrogen, the anode side of the fuel cell can also be quickly warmed up, and the warming-up of the entire fuel cell can be completed quickly.

According to the third aspect of the invention, air and hydrogen at appropriate temperatures can be supplied to the fuel cell according to the warm-up state of the fuel cell.

According to the fourth aspect of the present invention, since the amount of heat of the air is adjusted based on the outside air temperature, even if the outside air temperature changes, air and hydrogen at a suitable temperature are supplied to the fuel cell. be able to.

According to the fifth aspect of the present invention, the amount of heat of air is adjusted based on the amount of power generated by the fuel cell. Appropriate temperatures of hydrogen and air can be supplied to the fuel cell.

According to the sixth aspect of the invention, by adjusting the width (diameter) of the pipe of the bypass passage, it is possible to control the temperature of the air and hydrogen supplied to the fuel cell to an appropriate temperature.

[Brief description of the drawings]

FIG. 1 is an overall configuration diagram of a fuel cell system including a fuel cell warm-up device according to a first embodiment.

FIG. 2 is an explanatory diagram schematically illustrating a configuration of the fuel cell of FIG. 1;

FIG. 3 is a flowchart showing a part of a control flow of the fuel cell warm-up device of the first embodiment.

FIG. 4 is a flowchart illustrating another part of the control flow of the fuel cell warm-up device of the first embodiment.

FIG. 5 is a flowchart showing yet another part of the control flow of the fuel cell warm-up device of the first embodiment.

FIG. 6A is a flowchart showing a warm-up process in a normal mode, and FIG. 6B is a graph showing a relationship between a temperature of air supplied to a cathode humidifier and a throttle opening of a throttle valve.

FIG. 7 is an overall configuration diagram of a fuel cell system including a fuel cell warm-up device of a second embodiment.

FIG. 8 is a sectional view of a common pipe.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 fuel cell 2 air supply device 3 hydrogen supply device 4 control device 5 heat exchanger 21 air compressor (compressor) 22 bypass valve (heat amount adjustment means) 24 throttle valve (heat amount adjustment means) 41, 42 common pipe (heat exchanger) ) W1 Main passage W2 Bypass passage A Supply air H Supply hydrogen FCS Fuel cell system GS (GS1, GS2) Fuel cell warm-up device

Continued on the front page F term (reference) 5H026 AA06 5H027 AA06 KK21 KK28 MM01 MM04

Claims (6)

[Claims] 1. An air supply unit for supplying air to a cathode of a fuel cell, and a hydrogen supply unit for supplying hydrogen to an anode of the fuel cell, wherein the air supply unit supplies the air with A compressor having a compressor for pumping and having an air passage connecting the compressor and a cathode of the fuel cell, wherein the hydrogen supply means includes a hydrogen supply source for supplying the hydrogen and a hydrogen passage connecting an anode of the fuel cell. And a heat exchanger for transmitting heat of the air to the hydrogen is interposed between the air passage and the hydrogen passage. 2. The air passage includes a main passage and a bypass passage, and a radiator that cools the air is provided in the main passage. The passage through which the air passes includes the main passage and the bypass. The fuel cell warm-up device according to claim 1, further comprising a heat amount adjusting unit that switches between passages to adjust the heat amount of the air supplied to the fuel cell. 3. The fuel cell warm-up device according to claim 2, further comprising a control device that controls the heat amount adjusting means according to a warm-up state of the fuel cell. 4. The fuel cell warm-up device according to claim 2, further comprising a control device for controlling the heat amount adjusting means based on an outside air temperature. 5. The fuel cell warm-up device according to claim 2, further comprising a control device that controls the heat amount adjusting means according to the amount of power generated by the fuel cell. 6. The throttle according to claim 1, wherein a throttle whose opening is adjustable is provided in the bypass passage.
The fuel cell warm-up device according to any one of claims 1 to 5.