JP2000315513A - Radiator system for fuel cell/automobile - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent reduction in output due to reduction of an inside temperature when a fuel cell is in a low output operation state by closing a second cooling system and switching a cooling water passage for cooling a fuel cell and components other than the fuel cell by means of a first cooling system when the fuel cell is in a supercooled state. SOLUTION: This radiator system having a first radiator 4 and a second radiator 5 is provided with a first cooling system 2 cooling a fuel cell 6 and a second cooling system 3 cooling other components to be cooled other than the fuel cell 6, for example, cooling a controller 7, a driving motor 8, and an intercooler 9 for a compressor. In a low output operation state, respective three- way valves 17, 18 are set in the position for opening bypass passages 15, 16, and cooling water flowing outward from the first radiator 4 passes through the bypass passage 15 so as to subsequently cools down the other components to be cooled, passes through the bypass passage 16 so as to cool down the fuel cell 6, and then, flows into the first radiator 4 again. That is, cooling down is carried out by means of the first cooling system 2 while the second cooling system 3 is closed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a radiator system for a fuel cell vehicle.

[0002]

2. Description of the Related Art As a conventional radiator system for a fuel cell vehicle, for example, a fuel cell system (FIG. 8) described in Japanese Patent Application Laid-Open No. H10-3407334 has been reported.

In this fuel cell system 130, cooling water circulating in a cooling water passage 131 is supplied to a fuel cell 132.
After the temperature is increased by heat exchange within the radiator 133, the temperature is decreased in the radiator 133, and the temperature is again supplied to the fuel cell 132. The driving force for circulating the cooling water in the cooling water channel 131 is provided by a cooling water pump 134. At this time, the fuel cell 132
The inlet cooling water temperature T1 and the outlet cooling water temperature T2 are measured, and the difference ΔT between T1 and T2 is determined.
In the above case, the internal temperature of the fuel cell 132 is determined to be in a predetermined non-uniform state, and the driving voltage of the cooling water pump 134 is increased to bring the internal temperature of the fuel cell 132 closer to the optimum temperature. And try to average them out.
In FIG. 8, 135 is a cooling fan, and 136 is a control unit.

[0004]

However, in such a conventional radiator system for a fuel cell vehicle, it is necessary to pay attention to the following points in order to operate the system.

[0005] First, the fuel cell 132 radiates heat to the cooling water according to its output. However, since the heat-resistant temperature of the polymer film and the like constituting the fuel cell stack is limited, it is difficult to raise the temperature of the cooling water outlet. No, it must be controlled at a lower temperature than the reciprocating engine cooling water.

For this reason, the temperature difference between the cooling water and the atmosphere becomes small, and the radiator 133 that absorbs heat from the cooling water and discharges it to the atmosphere has a large heat transfer area.

Although not shown, the fuel cell vehicle has components that require cooling, such as a drive motor, a control device, and an intercooler for a compressor. In particular, the control device has a low heat-resistant temperature. Compared to
It must be kept at a low temperature.

For these reasons, the fuel cell 13 is installed in the vehicle.
(2) In order to mount a radiator capable of covering the heat radiation of other components, it is necessary to mount a plurality of radiators.

On the other hand, the internal temperature of the fuel cell 132 is controlled by the temperature of the outlet cooling water, the temperature of the outlet air supplied to the cathode, and the like. , 80 ° C to 90 ° C).

However, although the fuel cell 132 operates at a relatively low output, the output of the fuel cell 132 is low when the amount of air introduced into the radiator 133 is large (for example, during high-speed constant speed driving). However, when there is a high demand for cooling the drive motor or the like (for example, after traveling with repeated acceleration / deceleration),
The temperature of the cooling water in the cooling system of the fuel cell 132 including the radiator 133 decreases, and the internal temperature of the fuel cell 132 decreases. For this reason, for example, a large output cannot be taken out immediately or the radiator 133 is connected to the fuel cell 13.
Even when the cooling water is temporarily separated from the cooling system 2, there is a problem that the output is reduced when the cooling water in the radiator 133 is introduced into the fuel cell 132.

[0011] The present invention has been made in view of the above,
Its purpose is to prevent a decrease in output due to a decrease in internal temperature when the fuel cell is in a low output operation state,
Another object of the present invention is to provide a radiator system for a fuel cell vehicle that can generate high output in a short time from the low output operation state.

[0012]

According to the first aspect of the present invention,
In order to solve the above problems, a first cooling system that cools the fuel cell by cooling water circulating in a cooling water flow path that connects the fuel cell and the first radiator, and a component that requires cooling other than the fuel cell A second cooling system for cooling the component parts by cooling water circulating in a cooling water passage connecting the second radiator; and a second cooling system for closing the second cooling system when the fuel cell is in a supercooled state. The gist of the invention is to include a flow path switching unit that switches a cooling water flow path of the component so that the fuel cell and the component are cooled by one cooling system.

According to a second aspect of the present invention, in order to solve the above-mentioned problem, the first radiator of the first cooling system is disposed downstream of the cooling air from the second radiator of the second cooling system. The point is that

According to a third aspect of the present invention, in order to solve the above-mentioned problem, the constituent parts are connected between a cooling water outlet of the first radiator and a cooling water inlet of the fuel cell by switching a cooling water flow path. The point is that they are connected in series.

According to a fourth aspect of the present invention, in order to solve the above-mentioned problem, the flow path switching means is provided such that an inlet cooling water temperature of the fuel cell is equal to or lower than a predetermined cooling water upper limit temperature determined by a heat resistant temperature of the component. In this case, the gist is that the cooling water flow path of the component is switched.

According to a fifth aspect of the present invention, in order to solve the above problem, the flow path switching means is provided in a cooling water flow path which joins the first cooling system by switching a cooling water flow path of the component. When the cooling water passes through the fuel cell, the outlet cooling water temperature of the component located at the most downstream of the components is determined from a predetermined fuel cell outlet cooling water upper limit temperature determined by the heat-resistant temperature of the fuel cell. When the temperature is equal to or lower than the temperature obtained by subtracting the expected temperature difference between the inlet and outlet of the fuel cell, the gist of the invention is to switch the cooling water flow path of the component.

According to a sixth aspect of the present invention, in order to solve the above problem, the constituent parts are connected to the first cooling system in parallel with the fuel cell by switching a cooling water flow path. And

According to a seventh aspect of the present invention, in order to solve the above-mentioned problem, the flow path switching means includes a unit time of at least one of an inlet cooling water temperature and an outlet cooling water temperature of the fuel cell or an average value thereof. The gist of the present invention is to switch the cooling water flow path of the component when the reduction amount per hit is equal to or more than a predetermined set value.

According to an eighth aspect of the present invention, there is provided a control map changing method for changing a map for controlling an output of a pump of the first cooling system when a cooling water flow path of the component is switched. The point is to have means.

According to a ninth aspect of the present invention, in order to solve the above-mentioned problems, the flow path switching means includes an output of the fuel cell,
The gist of the invention is that the cooling water flow path of the component is switched when the value is equal to or less than a reference value determined by the performance of the fuel cell and the heat radiation performance of the first radiator.

[0021]

According to the present invention, a plurality of radiators are provided, and in a normal operation state, the fuel cell and other components requiring cooling are cooled by separate cooling systems. When the fuel cell is in a supercooled state, for example, when the fuel cell has a relatively low output, that is, the amount of heat radiation is relatively low, the cooling system of the component parts is closed and the fuel cell is By switching the cooling water flow paths of the components so as to cool both the components and the components, it is possible to suppress a decrease in the temperature of the cooling water of the fuel cell and a decrease in the internal temperature of the fuel cell. Can be prevented from lowering.

According to the second aspect of the present invention, the radiator of the cooling system of the fuel cell is disposed downstream of the cooling air from the radiator of the cooling system of the component parts. When the cooling water flow paths of the components are switched so as to cool both the components, the temperature of the cooling air is higher in the downstream radiator than in the upstream radiator. Temperature drop can be suppressed. In addition, when there is a component whose temperature needs to be controlled lower than that of a fuel cell, such as an electronic circuit, for example, using an upstream radiator for cooling the component reduces the cooling system. Can be capacity.

According to the third aspect of the present invention, by switching the cooling water flow path, the components are connected in series between the cooling water outlet of the radiator of the cooling system of the fuel cell and the cooling water inlet of the fuel cell. As a result, the cooling water that has flowed out of the radiator rises in temperature due to the heat radiation of the component parts and then flows into the fuel cell, thereby suppressing a decrease in the internal temperature of the fuel cell and changing from a low output to a high output. Time can be shortened.

According to the fourth aspect of the present invention, the switching of the cooling water flow path of the component is performed so that the inlet cooling water temperature of the fuel cell becomes equal to or lower than the predetermined maximum cooling water temperature determined by the heat resistant temperature of the component. By adopting the condition, if there is a component that needs to be controlled at a lower temperature than the fuel cell such as an electronic circuit in the component, for example, the cooling water flow path is shared between the fuel cell and the component. When the cooling water flow path of the component is switched, the flow of the cooling water that exceeds the heat resistant temperature to the component can be prevented, and the failure of the component can be prevented.

According to the fifth aspect of the present invention, the component located at the most downstream position in the cooling water flow path which joins the cooling system of the fuel cell by switching the cooling water flow path of the component. Subtract the predetermined fuel cell inlet / outlet temperature difference, which is expected to rise when the cooling water passes through the fuel cell, from the predetermined fuel cell outlet cooling water upper limit temperature determined by the heat-resistant temperature of the fuel cell. The operation of switching the cooling water flow path of the component so that the cooling water flow path is common to the fuel cell and the component by setting the condition that the temperature is equal to or lower than the temperature obtained by This can be performed most frequently while maintaining the heat-resistant temperature of the fuel cell, and thereby, the cooling water of the fuel cell can be maintained at an operable high temperature.

According to the sixth aspect of the present invention, by switching the cooling water flow path, the component is connected to the cooling system of the fuel cell field in parallel with the fuel cell.
As compared with the case of the series connection described above, the configuration of the cooling water flow path can be simplified, so that mounting on a vehicle is facilitated.

According to the present invention, at least one of the cooling water temperature at the inlet and the cooling water at the outlet of the fuel cell, or the average value thereof, decreases per unit time by:
By setting the cooling water flow path of the component parts to be equal to or greater than a predetermined set value, the radiation performance of the radiator that changes depending on the environment such as the amount and temperature of the introduced cooling air and the fuel cell The determination is made based on the amount of decrease in the temperature per unit time, which reflects the balance between the amount of heat released from the fuel cell and the amount of heat radiation that varies with the output of the fuel cell. Of the cooling water can be reduced.

According to the present invention, when the cooling water flow path of the component is switched, the map for controlling the output of the pump of the cooling system of the fuel cell is changed, whereby the cooling water flow of the component is changed. By switching the paths, the pressure loss of the cooling water flow path increases in the case of the cooling system connected in series according to claim 3, and the pressure loss decreases in the case of the cooling system connected in parallel according to claim 6. In the case of the above, the pressure loss also changes, but by adjusting the output of the cooling water pump, it is possible to flow the cooling water necessary for cooling the fuel cell and the components.

According to the ninth aspect of the present invention, the output of the fuel cell is equal to or less than a reference value determined by the performance of the fuel cell and the heat radiation performance of the radiator of the first cooling system for the fuel cell. The temperature sensor and its control required in the invention of claim 4, 5 or 7 can be omitted, or the measurement accuracy and the temperature assurance accuracy of the temperature sensor can be reduced. It can be dropped and can be a simple system.

[0030]

Embodiments of the present invention will be described below with reference to the drawings.

(First Embodiment) FIGS. 1 and 2 show the configuration of a radiator system for a fuel cell vehicle according to a first embodiment of the present invention. In particular, FIG. FIG. 2 is a system configuration diagram in an operation state, and FIG. 2 is a system configuration diagram in a low output operation state.

The radiator system 1 for a fuel cell vehicle includes two radiators 4 and 5, a first cooling system 2 for cooling the fuel cell 6, and components requiring cooling other than the fuel cell 6 (hereinafter “cooling required”). Other parts)), for example,
It has a control device 7, a drive motor 8, and another second cooling system 3 for cooling the compressor intercooler 9 and the like.

The first cooling system 2 is for cooling the fuel cell 6 with cooling water circulating in a cooling water passage 10 connecting the fuel cell 6 and the radiator 4. Radiation from the fuel cell 6 is released into the atmosphere by the radiator 4 via cooling water circulating in the cooling system 2. At this time, the cooling water circulating in the cooling system 2 is caused to flow by a cooling water pump 12 in the flow path 10 in an amount required for heat radiation of the fuel cell 6.

The second cooling system 3 includes cooling components other than the fuel cell 6 (in the illustrated example, a control device 7, a drive motor 8,
The other parts that need to be cooled are cooled by cooling water circulating in a cooling water passage 11 connecting the compressor intercooler 9) and the radiator 5. That is, the control device 7,
Other components requiring cooling, such as the drive motor 8 and the compressor intercooler 9, have a cooling system 3 separate from the fuel cell 6, and radiate heat to the atmosphere by the radiator 5. At this time,
The cooling water circulating in the cooling system 3 is flowed by the cooling water pump 13 in the flow path 11 in an amount of water necessary for heat radiation of other components requiring cooling.

The radiator 4 of the first cooling system 2 is arranged downstream of the radiator 5 of the second cooling system 3 with respect to the flow of the cooling air. The cooling fan 14 is provided immediately after the radiator 4 on the downstream side.

A bypass passage 15 is provided between the cooling water outlet of the radiator 4 and the cooling water inlet of the control device 7, and an externally controllable three-way valve 1 is provided at an upstream junction thereof.
7 are provided. Further, another bypass passage 16 is provided between the cooling water outlet of the compressor intercooler 9 and the cooling water inlet of the fuel cell 6, and a three-way valve 18 which can be externally controlled is also provided at its upstream junction. Is provided. By controlling these two three-way valves 17, 18, the cooling water flow paths of the other components requiring cooling are switched, and the first cooling system 2, that is, the cooling water flow path 1 of the fuel cell 6 is switched.
0 can be merged.

More specifically, in a normal operating state (determined by the conditions set forth below), as shown in FIG. 1, the three-way valves 17 and 18 are set at positions where the bypass passages 15 and 16 are closed, respectively, The cooling water of the battery 6 flows through the radiator 4 of the first cooling system 2, and the cooling water of other components requiring cooling flows through the radiator 5 of the second cooling system 3.

On the other hand, in a low output operation state (an operation state other than a normal operation condition), as shown in FIG. 2, each of the three-way valves 17 and 18 is set to a position where the bypass passages 15 and 16 are opened. The cooling water flowing out of the radiator 4 passes through the bypass passage 15, and sequentially cools the control device 7, the drive motor 8, the compressor intercooler 9, and the like as other components requiring cooling. The fuel is guided to the battery 6, exits the fuel cell 6, and flows into the radiator 4 again. That is, in this low output operation state, the second cooling system 3 is closed, and the first cooling system 2 cools both the fuel cell 6 and the other components requiring cooling.

Here, the condition for switching from the normal operation state to the low output operation state is as follows in the normal operation state in FIG.
The inlet cooling water temperature Tsin of the fuel cell 6 is lower than a predetermined cooling water upper limit temperature Tc0 determined by the heat-resistant temperature of the controller 7 having the lowest heat-resistant temperature among other cooling-necessary components, Tsin <Tc0, The outlet cooling water temperature Thout of the compressor intercooler 9 located at the most downstream of the parts is equal to a predetermined fuel cell outlet cooling water upper limit temperature (the fuel cell operation management reference cooling water outlet temperature) determined by the heat resistant temperature of the fuel cell 6. )
From Ts0, the temperature is lower than a temperature obtained by subtracting a predetermined fuel cell inlet / outlet temperature difference ΔTsL expected to rise when the cooling water passes through the fuel cell 6, and Thout <Ts0−ΔTsL. The above-mentioned temperature difference ΔTsL can be calculated based on the amount of heat radiation according to the output of the fuel cell 6 and the flow rate of the cooling water after switching the flow path.

The fuel cell inlet cooling water temperature T
The sin, the compressor intercooler outlet cooling water temperature Thout, and the fuel cell outlet cooling water temperature Tsout are respectively measured by temperature sensors (not shown), and respective measurement signals are supplied to a control unit (not shown) for controlling the system 1. Is output to The three-way valves 17 and 18 and the cooling water pumps 12 and 13 are also connected to the control unit.

The control unit has a ROM storing a control program and a control map for controlling the output (rotation speed) of the cooling water pump, a RAM serving as a work area for control, and the like. The three-way valves 17, 18 and the cooling water pumps 12, 13 are controlled based on the measurement signals from the respective temperature sensors.

Next, the control operation of the radiator system 1 for a fuel cell vehicle will be described with reference to the control flowchart shown in FIG. The control flowchart and the control map shown in FIG.
The control program and the data table are stored in the OM.

During start-up or when a low output operation command is issued,
First, in step S10, the measured fuel cell inlet cooling water temperature Tsin in the normal operation state shown in FIG. Water upper limit temperature T
It is determined whether or not Tsin <Tc0, which is lower than c0, and if the fuel cell inlet cooling water temperature Tsin is higher, the process returns to step S10 and the process is repeated. On the other hand, if the fuel cell inlet cooling water temperature Tsin is lower, the process proceeds to step S20.

In step S20, the cooling water passes through the fuel cell 6 from a predetermined fuel cell outlet cooling water upper limit temperature Ts0 determined by the measured compressor intercooler outlet cooling water temperature Thout determined by the heat-resistant temperature of the fuel cell 6. It is determined whether or not Thout <Ts0−ΔTsL, which is lower than the temperature obtained by subtracting the predetermined fuel cell inlet / outlet temperature difference ΔTsL, which is expected to rise, and the measured compressor intercooler outlet cooling water temperature Thout Is higher than step S
Returning to step 10, the process is repeated.

On the other hand, if the measured cooling water temperature Thout at the intercooler outlet for the compressor is lower, the process proceeds to step S30.

In step S30, each of the three-way valves 17, 18
Are respectively switched from the open / closed state shown in FIG. 1 to the open / closed state shown in FIG. 2, and the system 1 is switched from the normal operation state to the low output operation state.

After switching from the normal operation state to the low output operation state, in step S40, the cooling water pump 13 of the second cooling system 3 is used to reduce the power consumption at the time of low output.
And the cooling water pump 1 of the first cooling system 2
The output adjustment map for controlling the number of revolutions of the second is changed.

Further, in step S50, the measured fuel cell outlet cooling water temperature Tsout is determined by a predetermined fuel cell outlet cooling water upper limit temperature Ts0 determined by the heat resistant temperature of the fuel cell 6.
And the fuel cell outlet cooling water upper limit temperature T
It is determined whether or not Ts0−ΔTsc <Tsout <Ts0, which is higher than the temperature obtained by subtracting a predetermined control allowable temperature difference ΔTsc from s0.
The process proceeds to step S70, and if it is within this range, the process proceeds to step S60.

In step S60, the same judgment as in step S20 is performed. If the fuel cell outlet cooling water temperature Tsout is lower, the process returns to step S50 to wait, and if the fuel cell outlet cooling water temperature Tsout is higher, Proceed to step S70.

In step S70, the three-way valves 17, 18
Are respectively switched from the open / closed state shown in FIG. 2 to the open / closed state shown in FIG. 1, and the system 1 is switched from the low output operation state to the normal operation state.

As a result, according to the first embodiment, by disposing the radiator 4 of the first cooling system 2 downstream of the cooling air from the radiator 5 of the second cooling system 3, the discharge of the fuel cell 6 is achieved. Even if the amount of heat is small, if the amount of heat radiation from other control device 7, drive motor 8, compressor intercooler 9, etc. is large, the air temperature downstream of radiator 5 increases,
Since the cooling capacity of the radiator 4 decreases, the radiator 4
Of the cooling water of the fuel cell 6, and a decrease (supercooling) of the internal temperature of the fuel cell 6 can be suppressed.

In the low output state (see FIG. 2), the fuel cell 6 and other cooling components (control device 7, drive motor 8,
By cooling the same intercooler 9 for the compressor) with one radiator 4 using the same cooling system 2, the cooling capacity is reduced, and the decrease in the temperature of the cooling water can be suppressed.

Therefore, a decrease in the internal temperature of the fuel cell 6 (supercooling) can be suppressed, a decrease in the output of the fuel cell 6 can be prevented, and a high output can be generated from a low output in a short time.

Further, by using the radiator 4 on the downstream side as the radiator used in the low output operation state, the temperature of the cooling water of the radiator 4 can be maintained higher than in the case of using the radiator 5 on the upstream side. Even when the operation mode is switched to the normal operation state, the temperature of the cooling water supplied to the fuel cell 6 does not decrease. That is, the inlet cooling water temperature of the fuel cell 6 can be kept high.

Further, the condition for switching from the normal operation state to the low output operation state (cooling water flow path switching condition) is determined based on a predetermined cooling water upper limit temperature Tc0 at which the fuel cell inlet cooling water temperature Tsin is determined by the heat-resistant temperature of the controller 7. By setting Tsin <Tc0, the switching device does not exceed the cooling water upper limit temperature of the control device 7 having a low heat-resistant temperature when switching the cooling water flow path of other components requiring cooling, thereby preventing the failure of the control device 7. be able to.

In addition, a condition for switching from the normal operation state to the low output operation state (cooling water flow path switching condition)
Is the cooling water temperature Tho at the outlet of the intercooler for the compressor.
ut is subtracted from a predetermined fuel cell inlet / outlet temperature difference ΔTsL, which is expected to rise when the cooling water passes through the fuel cell 6, from a predetermined fuel cell outlet cooling water upper limit temperature Ts0 determined by the heat-resistant temperature of the fuel cell 6. By setting Thout <Ts0−ΔTsL, the temperature of the outlet cooling water of the fuel cell 6 is temporarily reduced by the cooling water flowing into the fuel cell 6 at the time of switching the cooling water flow path of the other parts requiring cooling. Can be prevented from rising as a result.

Further, after switching from the normal operation state to the low output operation state, the cooling water pump 13 of the second cooling system 3 is stopped, so that the power consumption at the time of low output can be reduced.

After switching from the normal operation state to the low output operation state, the cooling water pump 1 of the first cooling system 2
By changing the map for controlling the number of rotations of 2, the switching of the cooling water flow path prevents a decrease in the flow rate of the cooling water due to an increase in the pressure loss in the cooling water flow path, and the components (the fuel cell 6, the control device, 7), the flow rate of the cooling water necessary for the above can be secured.

(Second Embodiment) FIG. 4 is a flowchart showing a control operation of a radiator system for a fuel cell vehicle according to a second embodiment of the present invention. Note that the second embodiment has exactly the same configuration as the radiator system for a fuel cell vehicle corresponding to the first embodiment shown in FIGS. 1 and 2, and the second embodiment shown in FIG. Since the same basic control operation as in the control flowchart corresponding to the first embodiment is performed, only the portions different from the first embodiment will be described here, and the description of the same portions will be omitted.

The feature of the second embodiment is that, as shown in FIG. 4, the condition for switching from the normal operation state to the low output operation state (cooling water flow path switching condition) is determined by changing the measured fuel cell inlet cooling water temperature. Tsin is lower than a predetermined cooling water upper limit temperature Tc0 determined by the heat-resistant temperature of the control device 7, and in step S10, Tsin <Tc0, and the amount of decrease in the measured fuel cell outlet cooling water temperature Tsout per unit time is reduced. Tsout / ΔT is determined in step S2
2, Tsout / ΔT> ΔTs, which is larger than a preset value ΔTs.

As a result, according to the second embodiment, in addition to the above-described first embodiment, the switching from the normal operation state to the low output operation state is performed by the fuel cell 6.
Since the cooling water temperature of the cooling system 2 of the fuel cell 6 has a tendency to decrease, the decrease of the cooling water temperature of the fuel cell 6 can be determined at an early stage.
A decrease in the temperature of the cooling water for the fuel cell 6 can be suppressed.
That is, the temperature of the cooling water of the cooling system 2 of the fuel cell 6 can be more stably maintained.

(Third Embodiment) FIGS. 5 and 6 are diagrams showing a configuration of a radiator system for a fuel cell vehicle according to a third embodiment of the present invention. In particular, FIG. FIG. 6 shows the case of the operation state, and FIG. 6 shows the case of the low output operation state. Note that this third embodiment is
It has the same basic configuration as the radiator system for a fuel cell vehicle corresponding to the first embodiment shown in FIGS. 1 and 2, and the same components are denoted by the same reference numerals and the description thereof will be omitted. It is omitted.

The features of the third embodiment are shown in FIGS.
As shown in FIG. 2, in the normal operation state, the fuel cell 6 and other cooling components (the control device 7, the drive motor 8, the compressor intercooler 9) are controlled by the two radiators 4 and 5.
And the like are cooled by separate cooling systems 2 and 3 (see FIG. 5). However, in the low-power operation state, the radiator 4 is shared, and the fuel cell 6 and other necessary cooling components are cooled in parallel. That is, the system 1a is configured to have a water flow path (see FIG. 6).

That is, in the low output operation state, other components requiring cooling (control device 7, drive motor 8, compressor intercooler 9, etc.) are connected to the radiator 4 in parallel with the fuel cell 6. For this reason, two bypass passages 19,
20 are provided, and three-way valves 21 and 22 that can be controlled externally are provided at the respective junctions.

The control operation of the system 1a can be described according to the control flowchart shown in FIG. 3 or FIG. 4, but is the same as the content described in the first or second embodiment. Therefore, the description is omitted.

Further, according to the third embodiment, in addition to the above-described embodiment, other components requiring cooling during the low output operation state (control device 7, drive motor 8, compressor intercooler). 9) is connected to the radiator 4 in parallel with the fuel cell 6, whereby the cooling water flow path can be simply configured as compared with the case of the serial connection in the first embodiment. For this reason, mounting on a vehicle can be facilitated.

(Fourth Embodiment) FIG. 7 is a flowchart showing a control operation of a radiator system for a fuel cell vehicle according to a fourth embodiment of the present invention. The second embodiment is exactly the same as the radiator system for a fuel cell vehicle corresponding to the first embodiment shown in FIGS. 1 and 2 or the third embodiment shown in FIGS. It has the same configuration and performs the same basic control operation as the control flowchart corresponding to the first embodiment shown in FIG. 3 or the second embodiment shown in FIG. Only the portions different from the above-described embodiment will be described, and the description of the same portions will be omitted.

The feature of the fourth embodiment is that, as shown in FIG. 7, the condition for switching from the normal operation state to the low-output operation state (cooling water flow path switching condition) is determined by changing the measured fuel cell inlet cooling water temperature. Tsin is lower than a predetermined cooling water upper limit temperature Tc0 determined by the heat-resistant temperature of the control device 7, and in step S10, Tsin <Tc0, and the measured output Ls of the fuel cell 6 is changed to the fuel cell 6 in step S24. And the heat radiation performance of the radiator 4 are lower than a preset value Ls0, and Ls <Ls0.

In this case, in order to confirm the heat radiation performance of the radiator 4, the temperature of the cooling air is referred to as necessary,
Ls0, which is a reference value for comparison, may be a function of the cooling air temperature.

According to the fourth embodiment, in addition to the above-described embodiment, the switching from the normal operation state to the low output operation state is performed when the output of the fuel cell 6 becomes lower than the reference value. Therefore, when the change in the heat radiation environment of the fuel cell system is apt to change, the switching control can be reliably performed. At the same time, it is possible to omit the cooling water temperature detection sensor and its control required in the above-described embodiment, or to reduce the measurement accuracy and the temperature assurance accuracy of the temperature sensor, thereby configuring a simple system. Can be.

[Brief description of the drawings]

FIG. 1 is a diagram showing a configuration (normal operation state) of a radiator system for a fuel cell vehicle according to a first embodiment of the present invention.

FIG. 2 is a diagram showing a configuration (low-output operation state) of the radiator system for a fuel cell vehicle according to the first embodiment of the present invention.

FIG. 3 is a control flowchart for explaining a control operation of the radiator system for a fuel cell vehicle according to the first embodiment.

FIG. 4 is a control flowchart for illustrating a control operation of a radiator system for a fuel cell vehicle according to a second embodiment of the present invention.

FIG. 5 is a diagram showing a configuration (normal operation state) of a radiator system for a fuel cell vehicle according to a third embodiment of the present invention.

FIG. 6 is a diagram showing a configuration (low-power operation state) of a radiator system for a fuel cell vehicle according to a third embodiment of the present invention.

FIG. 7 is a control flowchart for illustrating a control operation of a radiator system for a fuel cell vehicle according to a fourth embodiment of the present invention.

FIG. 8 is a view showing a conventional radiator system for a fuel cell vehicle.

[Description of Signs] 2 First cooling system 3 Second cooling system 4 First radiator 5 Second radiator 6 Fuel cell 7 Control device 8 Drive motor 9 Compressor intercooler 10, 11 Cooling water channel 12, 13 Cooling water pump 14 Cooling fan 15, 16, 19, 20 Bypass passage 17, 18, 21, 22 Three-way valve

Claims (9)

[Claims] A first cooling system for cooling the fuel cell by cooling water circulating in a cooling water flow path connecting the fuel cell and the first radiator; a component other than the fuel cell requiring cooling; and a second cooling system. A second cooling system for cooling the component parts by cooling water circulating in a cooling water passage connecting the radiator to the radiator; and, when the fuel cell is in a supercooled state, closing the second cooling system to perform the first cooling. A radiator system for a fuel cell vehicle, comprising: flow path switching means for switching a cooling water flow path of the component so as to cool the fuel cell and the component by a system. 2. The fuel cell according to claim 1, wherein the first radiator of the first cooling system is disposed downstream of the cooling air from the second radiator of the second cooling system. Radiator system for automobiles. 3. The cooling device according to claim 1, wherein the components are connected in series between a cooling water outlet of the first radiator and a cooling water inlet of the fuel cell by switching a cooling water flow path. A radiator system for a fuel cell vehicle according to the above. 4. The cooling water flow path of the component when the inlet cooling water temperature of the fuel cell is equal to or lower than a predetermined cooling water upper limit temperature determined by the heat resistant temperature of the component. The radiator system for a fuel cell vehicle according to claim 3, wherein: 5. The component which is located at the most downstream position in the cooling water flow path which joins the first cooling system by switching the cooling water flow path of the component part. The outlet cooling water temperature is determined from a predetermined fuel cell outlet cooling water upper limit temperature determined by the heat resistant temperature of the fuel cell, and a predetermined fuel cell inlet / outlet temperature difference expected to increase when the cooling water passes through the fuel cell. The cooling water flow path of the component is switched when the temperature is equal to or lower than a temperature obtained by subtraction.
A radiator system for a fuel cell vehicle according to the above. 6. The radiator system for a fuel cell vehicle according to claim 1, wherein the component is connected to the first cooling system in parallel with the fuel cell by switching a cooling water flow path. . 7. The flow path switching means, wherein at least one of an inlet cooling water temperature and an outlet cooling water temperature of the fuel cell or a decrease amount per unit time of an average value thereof is equal to or more than a predetermined set value. 2. The radiator system for a fuel cell vehicle according to claim 1, wherein the cooling water flow path of the component part is switched. 8. The apparatus according to claim 1, further comprising control map changing means for changing a map for controlling an output of the pump of the first cooling system when a cooling water flow path of the component is switched. Radiator system for fuel cell vehicles. 9. The cooling water flow path of the component when an output of the fuel cell is equal to or less than a reference value determined by a performance of the fuel cell and a heat radiation performance of the first radiator. The radiator system for a fuel cell vehicle according to claim 1, wherein the switching is performed.