JP4608271B2 - Fuel cell system - Google Patents

Description

  The present invention relates to a fuel cell system.

  In recent years, fuel cells (including fuel cell stacks) have been actively developed as power sources for fuel cell vehicles. When the temperature of the fuel cell itself is low, the fuel cell cannot generate electricity sufficiently because the electrochemical reaction does not proceed efficiently. In addition, since the fuel cell has high energy conversion efficiency (that is, power generation efficiency) for converting chemical energy into electrical energy, it has a characteristic that its ability to warm itself (fuel cell) by power generation is small.

  Therefore, a system for warming up the fuel cell by circulating the air compressed and heated by the air pump into the fuel cell has been proposed (see Patent Document 1). In addition, a system for warming up the fuel cell by providing a combustion heater (combustor) for burning hydrogen has been proposed (see Patent Document 2).

JP 2000-195533 A (paragraph numbers 0015 to 0026, FIG. 1) JP 2000-164233 (paragraph numbers 0075 to 0087, FIG. 2)

However, in the system described in Patent Document 1, since the heated air is circulated inside the fuel cell, the temperature difference between the fuel cell and the air around the fuel cell is large, and the heat of the fuel cell is easily obtained. Since the heat is dissipated and the amount of heat that can be supplied to the fuel cell is small, the fuel cell may be difficult to warm up.
Moreover, in the system described in Patent Document 2, hydrogen (fuel) is combusted, and thus there is a problem that the fuel consumption of the fuel cell vehicle is deteriorated.

  Therefore, an object of the present invention is to provide a fuel cell system that can efficiently warm up a fuel cell by using existing equipment without consuming fuel wastefully.

As means for solving the above problems, the present invention provides a fuel cell mounted on a fuel cell vehicle, in which a plurality of single cells each having a solid polymer electrolyte membrane sandwiched between a fuel electrode and an air electrode are stacked. via a stack, a fuel cell box housing the fuel cell stack, a compressor the air is supplied to the air electrode in order to power the fuel cell stack, generates heat by the operation, the compressor in the order of the fuel cell stack An air blower that generates a flow of air, a fuel cell ambient temperature detector that detects an ambient temperature of the fuel cell stack , a heat generator ambient temperature detector that detects an ambient temperature of the compressor , and the fuel cell ambient temperature A blower device control device for controlling the operation of the blower device based on the detection results of the detection means and the heat generating device ambient temperature detector; and Comprising a fuel cell system air flowing by the operation of the air blowing device is characterized and Turkey to flow outside of the fuel cell stack a in the fuel cell box.

According to such a fuel cell system, an air flow is generated by the blower device, and this air flows through the heat generating device (compressor) and the outside of the fuel cell stack in this order. That is, the air is heated to the heating device (compressor) when passing through the heating device (compressor), the heated air flows through the outside of the fuel cell stack.
Therefore, the fuel cell stack can be warmed from the outside by the heated air and warmed up. Also, since heated air flows outside the fuel cell stack , it is possible to prevent heat from being dissipated from the warmed-up fuel cell stack . Furthermore, since the heated air flows outside the fuel cell stack, a relatively large flow path for the heated air can be secured, and a large amount of heat can be supplied to the fuel cell stack .

The heat generating device is at least one of (1) a device that generates power from the fuel cell and (2) a device that uses power generated by power generation. In other words, the heat generating device is an existing device that accompanies “(1) generating a fuel cell” or “(2) using electric power”. Further, the heat generating device is a device that generates heat upon operation. Therefore, a fuel cell system can be easily configured using such existing heat generating devices.
Furthermore, since such an existing heat generating device is used, the fuel is not wasted as compared with the case where heat is obtained by burning the fuel.
Such a fuel cell system is also effective for cooling a heat generating device.

  Here, “the ambient temperature of the fuel cell” in this specification includes the temperature of the fuel cell itself. Similarly, it is assumed that the “ambient temperature of the heat generating device” includes the temperature of the heat generating device itself.
  Therefore, according to such a fuel cell system, the blower device control device determines the ambient temperature of the fuel cell and the ambient temperature of the heat generating device based on the detection results of the fuel cell ambient temperature detection unit and the heat generation device ambient temperature detection unit. And the operation of the blower device can be controlled.

  Further, in the fuel cell system, in a state where the compressor is operated at the time of starting the system, the ambient temperature of the compressor detected by the heat generating device ambient temperature detection means is the fuel cell stack detected by the fuel cell ambient temperature detection means. When the temperature is higher than the ambient temperature, it is preferable that the blower control device operates the blower.

The fuel cell system further includes a heat generation device upstream air temperature detection unit that detects a temperature of air upstream of the compressor and is connected to the blower control device, and the blower control device includes: It is preferable to control the operation of the blower device based on the detection result of the air temperature detecting means on the upstream side of the heat generating device .
According to such a fuel cell system, the air blower control device is configured such that the ambient temperature of the fuel cell stack, the ambient temperature of the heat generating device (compressor), and the heat generating device based on the detection result of the air temperature detecting means upstream of the heat generating device. The operation of the blower device can be controlled after comparing at least two of the temperatures of the air upstream of the (compressor).

  In the fuel cell system, it is preferable that air from an air scoop formed in a hood of the fuel cell vehicle passes in the order of the compressor and the fuel cell stack.

  ADVANTAGE OF THE INVENTION According to this invention, the fuel cell system which can warm up a fuel cell efficiently can be provided, using an existing apparatus, without consuming fuel wastefully.

  Next, an embodiment of the present invention will be described in detail with reference to FIG. FIG. 1 is a plan view schematically showing the configuration of the fuel cell system according to this embodiment. The fuel cell, the heat generating device, and the like housed in the fuel cell box with the canopy of the fuel cell box removed. It is a figure which shows the arrangement | positioning condition of, and the flow of the air in a fuel cell box.

≪Configuration of fuel cell system≫
As shown in FIG. 1, a fuel cell system 1A according to this embodiment is mounted on a fuel cell vehicle. The fuel cell system 1A mainly includes a fuel cell 3, a fuel cell box 4, a heat generating device 5, a ventilation fan 6 (blower device), and temperature sensors S1, S2, S3 (fuel cell ambient temperature detecting means, heat generating device). Peripheral temperature detection means, heat generation equipment upstream air temperature detection means), and a control device 8 (blower device control device).
Hereinafter, the fuel cell box 4, the fuel cell 3, the heat generating device 5, the ventilation fan 6, the temperature sensors S1 to S3, and the control device 8 will be described in this order.

<Fuel cell box>
The fuel cell box 4 is a thin box, and is a box for housing the fuel cell 3 and the heat generating device 5 and protecting them. Such a fuel cell box 4 is composed of a box body and a canopy as described in, for example, Japanese Patent Application Laid-Open Nos. 2003-146087 and 2003-151605. The fuel cell box 4 is fixed to a main frame extending in the front and rear of the vehicle under the floor panel of the fuel cell vehicle. Here, for convenience of explanation, “front side” and “rear side” are set as shown in FIG.

<Fuel cell>
The fuel cell 3 is a power source for a fuel cell vehicle, and is configured by laminating a predetermined number of single cells each having both sides of a solid polymer electrolyte membrane sandwiched between a fuel electrode and an air electrode. It is called. Such a fuel cell 3 is arranged slightly on the rear side in the fuel cell box 4.

<Heat generation equipment>
The heat generating device 5 is at least one of “(1) a device that generates power from the fuel cell 3” and “(2) a device that uses electric power generated by power generation”, and is an existing device that accompanies the operation of the fuel cell 3. is there. That is, the fuel cell system 1 </ b> A according to the present embodiment can be easily configured using such an existing heat generating device 5.

  The heat generating device 5 is a device that generates heat when activated. Here, the heat generating device 5 does not generate heat by itself consuming fuel such as hydrogen for the purpose of generating heat, but the heat generating device 5 is for realizing other purposes (power generation of the fuel cell, use of power). It is a device that generates heat as a result of operation. Therefore, even if the heat generating device 5 is activated to generate heat, fuel such as hydrogen is not newly wasted due to heat generation, and the fuel consumption of the fuel cell vehicle is not reduced.

  Such a heat generating device 5 is arranged in front of the fuel cell 3 in the fuel cell box 4. Moreover, it is preferable that the heat generating apparatus 5 has a heat exchange part (for example, fin) for exchanging heat with air with high efficiency on its outer surface.

Specifically, “(1) equipment for generating power from the fuel cell 3” includes, for example, a compressor that sends air to the cathode side of the fuel cell 3, an ECU that controls the compressor, and electric heat for heating the fuel cell 3. Examples thereof include a heater / hydrogen combustion heater, an MH heater using heat generated by hydrogen absorption of a hydrogen storage alloy, and a heater for heating a hydrogen storage alloy in which hydrogen is stored.
Examples of “(2) devices that use power generated by power generation” include a contactor, a PCU (power plant control unit) that controls a traveling motor, and the like.

<Ventilation fan>
The ventilation fan 6 is attached to the wall on the front side of the fuel cell box 4. When the ventilation fan 6 is activated, the air on the front side of the fuel cell box 4 is taken in, and the taken-in air flows toward the rear side in the fuel cell box 4, and then on the rear side of the fuel cell box 4. It is discharged from an exhaust hole 4a formed in the wall. That is, the ventilation fan 6 is a blower device that generates a flow of air that passes through the heating device 5 and the fuel cell 3 in this order. That is, in this embodiment, the front side is the upstream side of the air flow, and the rear side is the downstream side.
Further, the air flows along the outer surface of the fuel cell 3 when passing through the fuel cell 3. In order to circulate air along the outside of the fuel cell 3, for example, a rib may be appropriately provided on the bottom of the fuel cell box 4, or the inside of the fuel cell box 4 may have a predetermined layout.

<Temperature sensor>
The temperature sensors S1 to S3 can be appropriately selected from known temperature sensors. The temperature sensor S1 (fuel cell ambient temperature detection means) is disposed around the fuel cell 3 in the fuel cell box 4, and the temperature T1 of the air around the fuel cell 3 (hereinafter referred to as fuel cell ambient temperature T1). Can be detected. The temperature sensor S2 (heat generating device ambient temperature detecting means) is disposed around the heat generating device 5 in the fuel cell box 4, and the temperature T2 of the air around the heat generating device 5 (hereinafter referred to as the heat generating device ambient temperature T2). Can be detected. The temperature sensor S3 (heating device upstream air temperature detection means) is a sensor that detects the temperature T3 of the air sent to the heating device 5, that is, the temperature of the air upstream of the heating device 5. In the present embodiment, the temperature sensor S3 is disposed immediately upstream of the ventilation fan 6, and can detect the temperature T3 of air taken into the ventilation fan 6 (hereinafter referred to as intake air temperature T3). .

<Control device>
The control device 8 includes a CPU, a ROM, an I / O, and the like, and is electrically connected to the ventilation fan 6 and the temperature sensors S1 to S3. Based on the detection results of the temperature sensors S1 to S3, the control device 8 specifically, the fuel cell ambient temperature T1 detected by the temperature sensor S1, the heating device ambient temperature T2 detected by the temperature sensor S2, and The intake air temperature T3 detected by the temperature sensor S3 can be compared to control the operation of the ventilation fan 6 such as ON / OFF and rotation speed. Specific control by the control device 8 will be described later.

≪Operation of fuel cell system≫
Next, the operation of the fuel cell system 1A will be described.

[Fuel cell warm-up]
For example, when the fuel cell vehicle is started, the heating device 5 such as an ECU or a compressor is operated to generate heat in conjunction with turning on an IGSW (ignition switch) (not shown), and the control device 8 sets the temperature sensors S1 and S2. Then, when “heating device ambient temperature T2> fuel cell ambient temperature T1” is detected, the ventilation fan 6 is activated. By the operation of the ventilation fan 6, air is taken into the fuel cell box 4, and the taken air flows through the heating device 5 and the fuel cell 3 in this order.

  The air flowing in this way is heated by the heat generating device 5 that generates heat when passing around the heat generating device 5. And the heated air distribute | circulates the outer side of the fuel cell 3 along the outer surface. As a result, the heated air warms the fuel cell 3 from the outside. At this time, the temperature difference between the fuel cell 3 and the surrounding air of the fuel cell 3 is reduced, and the heat of the warmed-up fuel cell 3 is not dissipated as in the prior art. Thus, according to the fuel cell system 1A, the fuel cell 3 can be warmed up early.

  On the other hand, for example, immediately after the IGSW is turned on and the heat generating device 5 is not generating heat, that is, while detecting “heat generating device ambient temperature T2 <fuel cell ambient temperature T1”, the control device 8 is connected to the ventilation fan 6. Do not operate. Thereby, useless consumption of electric power can be prevented.

[Cooling of heat-generating equipment]
In addition, according to the fuel cell system 1A according to the present embodiment, the heat-generating device 5 that has generated excessive heat can be cooled.
Specifically, when the control device 8 detects “taken air temperature T3 <heating device ambient temperature T2”, it activates the ventilation fan 6 to send air into the heating device 5. Thereby, the heat generating apparatus 5 can be cooled.
On the other hand, the control device 8 does not operate the ventilation fan 6 while detecting “take-in air temperature T3> heating device ambient temperature T2”. Thereby, it can prevent that the heat-emitting apparatus 5 is further heated by intake air.

  Table 1 summarizes the control of the ventilation fan 6 by such a control device 8.

  As described above, according to the fuel cell system 1A according to the present embodiment, compared to the case where the fuel is burned to obtain heat, the fuel cell is used without using the fuel wastefully and using existing equipment. Can be warmed up efficiently.

  As mentioned above, although an example was described about suitable embodiment of this invention, this invention is not limited to the said embodiment, For example, the following changes can be made in the range which does not deviate from the meaning of this invention.

In the above-described embodiment, the ventilation fan 6 is provided on the wall on the front side (air intake side) of the fuel cell box 4. However, it is possible to generate an air flow that passes through the heating device 5 and the fuel cell 3 in this order. If so, the position of the ventilation fan 6 may be any.
For example, as shown in FIG. 2, the ventilation fan 6 may be provided on the rear side (air discharge side) wall of the fuel cell box 4, or as shown in FIG. Alternatively, it may be disposed between the heat generating device 5 and the fuel cell 3.
When the ventilation fan 6 is provided on the rear side of the fuel cell box 4 as in the fuel cell system 1B shown in FIG. 2, air is taken in from the front-side intake hole 4b. Further, the position of the temperature sensor S3 is not changed, and the temperature of the air upstream of the heat generating device 5 (that is, the air sent to the heat generating device 5) can be detected.

In the above-described embodiment, the heat generating device 5 is arranged in the fuel cell box 4. However, the position of the heat generating device 5 may be on the upstream side of the fuel cell 3 in the air flow toward the fuel cell 3. For example, you may arrange | position outside the fuel cell box 4 like the fuel cell system 1C shown in FIG.
In the above-described embodiment, the air passing through the heat generating device 5 circulates around the heat generating device 5, that is, along the outer surface of the heat generating device 5 (see FIG. 1), but as shown in FIG. The heat generating device 5 may be routed through.

Here, the fuel cell system 1 </ b> C shown in FIG. 3 will be described. The heat generating device 5 and the ventilation fan 6 are disposed outside the fuel cell box 4. The ventilation fan 6 is connected to the heat generating device 5 via a pipe 11A, and the heat generating device 5 is connected to the fuel cell box 4 via a pipe 11B. When the ventilation fan 6 is operated, the air on the front side of the ventilation fan 6 is taken in, and the taken-in air passes through the inside of the pipe 11A, the inside of the heat generating device 5, and the inside of the pipe 11B in order. It is introduced from the take-in hole 4 b of the battery box 4.
Further, the air is heated when it flows through the inside of the heat generating device 5. Further, a temperature sensor S3 for detecting the intake air temperature T3 is disposed on the front side of the ventilation fan 6. Furthermore, the temperature sensor S <b> 2 that detects the ambient temperature of the heat generating device 5 is disposed in the air flow path in the heat generating device 5.
As a specific example in which air circulates inside the heat generating device 5 in this way, for example, the heat generating device 5 is a compressor that sends air to the cathode side of the fuel cell 3, and exhaust gas discharged by the operation of the compressor is The case where it supplies to the fuel cell box 4 as it is is mentioned.

  Further, a pipe is connected to the upstream side of the ventilation fan 6 (fuel cell box 4) of the above-described embodiment, and “at least a part of the upstream side of the pipe” is a position where the air in the part can be heated by solar heat. It is good to arrange in.

Specifically, for example, as shown in FIG. 4, the upstream end of the pipe 11C on the upstream side of the ventilation fan 6 is disposed in an air scoop 13a (semi-closed space) formed in the hood 13 of the fuel cell vehicle, The air in the air scoop 13a heated by sunlight may be supplied to the fuel cell box 4. In this case, the pipe 11C and the air scoop 13a are regarded as “a pipe connected to the upstream side of the ventilation fan 6 (fuel cell box 4)”, and the air scoop 13a is “at least on the upstream side of the pipe”. Corresponds to “part”.
However, the position of “a part of the pipe connected to the upstream side of the ventilation fan 6 (fuel cell box 4)” is not limited to the upstream position as in the air scoop 13a, but may be other midstream positions. Moreover, in order to absorb solar heat suitably, you may meander "a part of piping connected to the said upstream".

  In this case, it is preferable to arrange the temperature sensor S3 in the air scoop 13a (a part of the pipe) (see FIG. 4). Even if the control device 8 detects that “the heat generating device ambient temperature T2≈the fuel cell ambient temperature T1” immediately after the IGSW is turned on and the heat generating device 5 is not generating heat, When the air is warm and “taken air temperature T3> heating device ambient temperature T2≈fuel cell ambient temperature T1” is detected, the ventilation fan 6 is operated to take in the warm air into the fuel cell box 4 and The battery 3 can be warmed up early.

It is a top view which shows typically the structure of the fuel cell system which concerns on this embodiment. It is a top view which shows typically the structure of the fuel cell system which concerns on a modification. It is a top view which shows typically the structure of the fuel cell system which concerns on a modification. It is a sectional side view which shows the air intake part of the fuel cell system which concerns on a modification.

Explanation of symbols

1A, 1B, 1C Fuel cell system 3 Fuel cell 4 Fuel cell box 5 Heating device 6 Ventilation fan (blower device)
8 Control device (Blower equipment control device)
11A, 11B, 11C Piping 13 Bonnet 13a Air scoop S1 Temperature sensor (Fuel cell ambient temperature detection means)
S2 Temperature sensor (heating device ambient temperature detection means)
S3 Temperature sensor (heating device upstream air temperature detection means)

Claims (4)

A fuel cell stack configured by laminating a plurality of single cells each having a solid polymer electrolyte membrane sandwiched between a fuel electrode and an air electrode, and mounted on a fuel cell vehicle ;
A fuel cell box housing the fuel cell stack,
A compressor that supplies air to the air electrode to generate power in the fuel cell stack, and generates heat by operation;
An air blower that generates an air flow that passes through the compressor and the fuel cell stack ;
Fuel cell ambient temperature detecting means for detecting the ambient temperature of the fuel cell stack ;
A heating device ambient temperature detection means for detecting the ambient temperature of the compressor ;
A blower device control device for controlling the operation of the blower device based on the detection results of the fuel cell ambient temperature detector and the heat generating device ambient temperature detector;
With
You flowing outside of the fuel cell stack air flow by the operation of the air blowing device is within the fuel cell box
The fuel cell system which is characterized a call.   In a state where the compressor is operating at the time of starting the system, when the ambient temperature of the compressor detected by the heat generating device ambient temperature detection means is higher than the ambient temperature of the fuel cell stack detected by the fuel cell ambient temperature detection means, The blower control device operates the blower
  The fuel cell system according to claim 1. Detecting the temperature of the air upstream of the compressor , further comprising a heating device upstream air temperature detection means connected to the blower control device,
The blower device control device controls the operation of the blower device based on the detection result of the air temperature detecting means upstream of the heat generating device.
The fuel cell system according to claim 1 or claim 2, wherein the this.   Air from an air scoop formed in the hood of the fuel cell vehicle passes through the compressor and the fuel cell stack in this order.
  The fuel cell system according to any one of claims 1 to 3, wherein

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