WO2024080609A1

WO2024080609A1 - Fuel cell cooling method and system

Info

Publication number: WO2024080609A1
Application number: PCT/KR2023/014237
Authority: WO
Inventors: 최훈
Original assignee: 에스케이이엔에스 주식회사
Priority date: 2022-10-12
Filing date: 2023-09-20
Publication date: 2024-04-18
Also published as: KR20240050929A

Abstract

The present invention relates to a fuel cell cooling method and system, and to a fuel cell cooling method and a fuel cell cooling system to which same is applied, the method comprising: a coolant circulation step of usually repeating a process in which a heat exchanger provided at a main cooling line cools a high-temperature coolant to a low-temperature coolant when the high-temperature coolant is discharged from a fuel cell, thereby suppling same to the fuel cell; a thermal load monitoring step of monitoring thermal load changes in the fuel cell; and a cooling line switching step of switching a cooling line from the main cooling line to an auxiliary cooling line including an auxiliary coolant tank so that, if the thermal load of the fuel cell sharply increases to be greater than usual, a low-temperature coolant stored in the auxiliary coolant tank is supplied to the fuel cell before the low-temperature coolant supplied from the heat exchanger to the fuel cell.

Description

Fuel cell cooling method and system

The present invention relates to a fuel cell cooling method and system, and more specifically, to enable stable use of the fuel cell by efficiently managing the heat load generated from the fuel cell.

In particular, the present invention rapidly increases the heat load of the fuel cell by preferentially supplying the coolant stored in a separate auxiliary coolant tank faster than the time when the coolant cooled in the heat exchanger is supplied to the fuel cell when the heat load of the fuel cell suddenly increases. It relates to a fuel cell cooling method and system that can reduce and enable efficient heat load management.

A fuel cell is a device that converts energy from chemical changes into electrical energy. It mainly uses hydrogen and oxygen to generate electrical energy, and water is produced as a by-product, so it is eco-friendly and does not produce pollutants. It is a power generation device and is one of the technologies attracting attention in the eco-friendly and renewable energy fields.

In these fuel cells, heat is generated at the cathode (anode) side where oxygen is supplied during the reaction between hydrogen and oxygen. In order for the fuel cell to demonstrate optimal performance, this generated heat must be quickly discharged to the outside. And thermal management to maintain a stable temperature is more important than anything else.

As a method of cooling the heat generated from the fuel cell, coolant is mainly used, and the heat generated from the fuel cell is continuously cooled by circulating the coolant cooled in the heat exchanger (radiator) to the fuel cell. do.

Meanwhile, the heat exchanger for cooling the coolant supplied to the fuel cell mainly cools the coolant through heat exchange with atmospheric air. Due to the characteristics of this heat exchange method, the heat exchange efficiency of the heat exchanger varies depending on the season when the outside temperature changes. This causes a problem in that thermal management of the fuel cell cannot be performed stably.

One of the technologies to solve this problem is the prior art document, Republic of Korea Patent Publication No. 10-1592652, 'Thermal management system and method for fuel cell vehicles' (hereinafter referred to as 'prior art').

The prior art is to increase the flow rate and heat dissipation of coolant passing through a radiator (heat exchanger), thereby reducing the frequency of entering the high-temperature current limit mode due to overheating of the fuel cell and enabling stable thermal management of the fuel cell.

Looking more specifically, the prior art blocks the path of the coolant circulating through the ion filter that makes up the fuel cell system, increases the flow rate of the coolant circulating through the radiator, and increases the heat dissipation amount of the coolant, thereby quickly dissipating the heat generated from the fuel cell. It was designed to be discharged properly.

In other words, the prior art blocks the supply of coolant to the ion filter and allows a greater amount of coolant to be supplied to the radiator, thereby allowing a greater amount of heat energy to be discharged from the radiator to the outside.

However, in this prior art, the time for which coolant cooled from the radiator is supplied to the fuel cell is kept constant, so from the point when the heat load of the fuel cell suddenly increases, the amount of heat radiation increases according to the sudden increase in heat load, and the cooled coolant is supplied to the fuel cell. It can be seen that the delay time until it is supplied does not change.

As a result, the heat load of the fuel cell rapidly increases and the fuel cell has no choice but to be exposed to a thermal overload state during the delay time, and it can be seen that the prior art has not been able to solve the problem that performance deterioration, damage, and damage to the fuel cell may occur due to this. there is.

In order to solve the above problems, the purpose of the present invention is to provide a fuel cell cooling method and system that can enable stable use of the fuel cell by efficiently managing the heat load generated from the fuel cell.

In particular, the present invention rapidly increases the heat load of the fuel cell by preferentially supplying the coolant stored in a separate auxiliary coolant tank faster than the time when the coolant cooled in the heat exchanger is supplied to the fuel cell when the heat load of the fuel cell suddenly increases. The purpose is to provide a fuel cell cooling method and system that can reduce the heat load and enable efficient heat load management.

In addition, the present invention provides for supplying coolant cooled from the heat exchanger again when the priority supply time for preferentially supplying the coolant stored in the auxiliary coolant tank has elapsed or when the time for supplying the coolant cooled from the heat exchanger to the fuel cell has elapsed. The purpose is to provide a fuel cell cooling method and system that enables efficient supply of coolant by redirecting (returning) the cooling line.

In order to achieve the above object, the fuel cell cooling method according to the present invention is a process in which, when high-temperature coolant is normally discharged from the fuel cell, a heat exchanger configured in the main cooling line cools the high-temperature coolant into low-temperature coolant and supplies it to the fuel cell. Circulating coolant circulation step; A heat load monitoring step of monitoring changes in heat load of the fuel cell; And when the heat load of the fuel cell rapidly increases compared to usual, an auxiliary coolant tank is configured in the main cooling line to supply the low-temperature coolant stored in the auxiliary coolant tank to the fuel cell preferentially compared to the low-temperature coolant supplied from the heat exchanger to the fuel cell. It includes a cooling line conversion step of converting the cooling line to an auxiliary cooling line.

In addition, after the cooling line switching step, when the set priority supply time has elapsed, a cooling line return step of switching the cooling line from the auxiliary cooling line to the main cooling line may be further included.

In addition, in the cooling water circulation step, when the heat load of the fuel cell is relatively low within the allowable range, low-high temperature coolant, which has a relatively low temperature among high-temperature coolants, is discharged from the fuel cell, and the heat exchanger exchanges heat with the low-high temperature coolant. It is cooled with high-low-temperature coolant, which has a relatively high temperature among low-temperature coolants. When the heat load of the fuel cell is relatively high within the allowable range, high-temperature coolant, which has a relatively high temperature among high-temperature coolants, is discharged from the fuel cell, and the heat exchanger By heat exchanging high-temperature coolant, it can be cooled with low-temperature coolant, which has a relatively lower temperature among low-temperature coolants.

In addition, the auxiliary coolant tank stores low-temperature coolant having a relatively low temperature among the low-temperature coolants, and in the cooling line switching step, when the heat load of the fuel cell rapidly increases and exceeds the allowable range, heat exchange is performed in the heat exchanger. The low-temperature coolant stored in the auxiliary coolant tank can be preferentially supplied to the fuel cell rather than the low-temperature coolant that is used.

In addition, in the cooling line return step, the low-temperature coolant stored in the auxiliary coolant tank is preferentially supplied to the fuel cell in a set priority supply amount, or the low-temperature coolant heat-exchanged in the heat exchanger is supplied to the fuel cell after the priority supply time has elapsed. When this happens, the cooling line can be re-converted from the auxiliary cooling line to the main cooling line.

In addition, the fuel cell cooling system according to the present invention includes a fuel cell; a heat exchanger configured to supply cooling water to the fuel cell; an auxiliary coolant tank configured to supply coolant to the fuel cell faster than the coolant of the heat exchanger; and a control unit that controls to supply coolant heat-exchanged in the heat exchanger to the fuel cell under normal circumstances and to preferentially supply coolant stored in the auxiliary coolant tank to the fuel cell when the heat load of the fuel cell suddenly increases.

Additionally, a coolant recovery line configured to allow high-temperature coolant absorbing heat generated from the fuel cell to move to at least one of a heat exchanger and an auxiliary coolant tank; a main cooling line configured to move the low-temperature cooling water heat-exchanged in the heat exchanger to the fuel cell; and an auxiliary cooling line configured to allow low-temperature coolant stored in the auxiliary coolant tank to move to the fuel cell, wherein the control unit controls the coolant to circulate between the coolant recovery line and the main cooling line at normal times, and the heat load of the fuel cell suddenly increases. The cooling water recovery line and auxiliary cooling line can be controlled to circulate.

In addition, the auxiliary cooling line is configured to supply low-temperature coolant heat-exchanged in the heat exchanger to the auxiliary coolant tank, and the control unit preferentially supplies the coolant stored in the auxiliary coolant tank to the fuel cell when the heat load of the fuel cell rapidly increases. At the same time, the coolant heat exchanged in the heat exchanger can be supplied to the auxiliary coolant tank.

In addition, when the heat load of the fuel cell suddenly increases, the control unit controls the coolant recovery line and the auxiliary cooling line to circulate during the priority supply time during which at least a portion of the low-temperature coolant stored in the auxiliary coolant tank is preferentially supplied to the fuel cell, and the corresponding priority When the supply time elapses, the coolant recovery line and main cooling line can be controlled to circulate.

In addition, the control unit determines whether at least a portion of the low-temperature coolant stored in the auxiliary coolant tank is discharged, a certain amount of high-temperature coolant recovered from the fuel cell flows into the auxiliary coolant tank, or the temperature of the coolant inside the auxiliary coolant tank is adjusted to a certain temperature. Once reached, it can be determined that the priority supply time has elapsed.

Through the above solution, the present invention has the advantage of enabling stable use of the fuel cell by efficiently managing the heat load generated from the fuel cell.

Specifically, the present invention reduces the heat load of the fuel cell by preferentially supplying the coolant stored in a separate auxiliary coolant tank faster than the time when the coolant cooled in the heat exchanger is supplied to the fuel cell when the heat load of the fuel cell suddenly increases. It has the advantage of being able to quickly reduce heat load and enable efficient heat load management.

Accordingly, the present invention has the advantage of minimizing performance degradation and damage to the fuel cell by minimizing the duration of the thermal overload state in which the heat load of the fuel cell suddenly increases, as well as maintaining stable operation of the fuel cell continuously. there is.

In addition, the present invention provides for supplying coolant cooled from the heat exchanger again when the priority supply time for preferentially supplying the coolant stored in the auxiliary coolant tank has elapsed or when the time for supplying the coolant cooled from the heat exchanger to the fuel cell has elapsed. There is an advantage in that efficient management and supply of coolant is possible by redirecting (returning) the cooling line.

In addition, the present invention additionally configures only an auxiliary coolant tank configured to naturally cool the coolant by external air, and enables rapid cooling of the fuel cell when the heat load suddenly increases, thereby efficiently managing the heat of the fuel cell with a minimal configuration. There are advantages to this.

Accordingly, the present invention can be easily applied to fuel cell cooling systems with various functions and configurations, as well as to various products such as vehicles using fuel cells, and can also be applied to various products in various fields. Therefore, it has the advantage of greatly improving usability and applicability.

1 is a flowchart showing an embodiment of a fuel cell cooling method according to the present invention.

FIG. 2 is a schematic configuration diagram of a fuel cell cooling system for explaining FIG. 1.

FIG. 3 is a flowchart showing another embodiment of FIG. 1.

Figure 4 is a flowchart showing a specific embodiment of step 'S100' shown in Figure 3.

FIG. 5 is a schematic configuration diagram of a fuel cell cooling system for explaining FIG. 4.

Figure 6 is a flowchart showing a specific embodiment of step 'S300' shown in Figure 3.

Figure 7 is a configuration diagram showing an embodiment of a fuel cell cooling system according to the present invention.

Figures 8 and 9 are configuration diagrams showing other embodiments of Figure 7.

Examples of the fuel cell cooling method and system according to the present invention can be applied in various ways, and the most preferred embodiment will be described below with reference to the attached drawings.

FIG. 1 is a flowchart showing an embodiment of a fuel cell cooling method according to the present invention, and FIG. 2 is a schematic configuration diagram of a fuel cell cooling system for explaining FIG. 1.

Referring to FIG. 1, the fuel cell cooling method includes a coolant circulation step (S100), a heat load monitoring step (S200), and a cooling line switching step (S300).

First, looking at the schematic configuration of a cooling system to which the fuel cell cooling method of the present invention is applied with reference to FIG. 2, the fuel cell 100 and the heat exchanger 200 may be configured to circulate coolant through cooling lines. .

At this time, the line through which the high-temperature coolant heat-exchanged in the fuel cell 100 moves to the heat exchanger 200 is the coolant recovery line 410, and the low-temperature coolant heat-exchanged in the heat exchanger 200 moves to the fuel cell 100. The moving line is the main cooling line (420).

And, to the main cooling line 420, an auxiliary coolant tank 300 storing low-temperature coolant (C) may be connected in parallel by the auxiliary cooling line 430, and the part where the auxiliary cooling line 430 is connected may contain coolant. A valve (3-way valve) may be configured to control the movement of .

Therefore, in the coolant circulation step (S100), as shown in (a) of FIG. 2, when high-temperature coolant is normally discharged from the fuel cell 100, the heat exchanger ( The process of cooling the high-temperature coolant to low-temperature coolant and supplying it to the fuel cell 100 is cycled.

In the heat load monitoring step (S200), changes in the heat load of the fuel cell 100 are monitored while the coolant circulation step (S100) is in progress.

At this time, if the heat load of the fuel cell rapidly increases compared to usual, a cooling line switching step (S300) is performed.

In the cooling line switching step (S300), in the process of monitoring changes in the heat load of the fuel cell 100, if the heat load of the fuel cell 100 increases rapidly compared to usual, the main cooling is switched on as shown in (b) of FIG. 2. By switching the cooling line from the line 420 to the auxiliary cooling line 430, the low-temperature coolant (C) stored in the auxiliary coolant tank 300 is first supplied to the fuel cell 100.

In other words, in the cooling line switching step (S300), the low-temperature coolant (C) stored in the auxiliary coolant tank (300) is supplied faster than the time for supplying the low-temperature coolant cooled in the heat exchanger (200) to the fuel cell (100). It is supplied first to the fuel cell 100.

And, as shown in (b) of FIG. 2, the amount of coolant supplied from the auxiliary coolant tank 300 to the fuel cell 100 can be supplemented with coolant heat exchanged in the heat exchanger 200.

To this end, the auxiliary cooling line 430 may be configured to supply low-temperature coolant heat-exchanged in the heat exchanger 200 to the auxiliary coolant tank 300, and controls the operation of each component, especially the operation of the valve (3-way valve). When the heat load of the fuel cell 100 suddenly increases, the control unit supplies the coolant stored in the auxiliary coolant tank 300 to the fuel cell 100 first, and at the same time supplies the coolant heat-exchanged in the heat exchanger 200 to the auxiliary coolant tank 300. can be supplied to.

As a result, the cooling line conversion step (S300) changes the circulation line of the coolant circulating between the fuel cell 100 and the heat exchanger 200 to the fuel cell 100, the heat exchanger 200, and the auxiliary coolant tank 300. It can be switched to cycle.

However, the amount of coolant supplied to the fuel cell 100 does not necessarily have to be supplemented with the coolant heat exchanged in the heat exchanger 200, and the flow rate of the coolant passing through the fuel cell 100 can be maintained constant. If so, it is natural that various methods or configurations can be applied, and examples of some of them will be looked at below.

Additionally, the line through which the coolant moves is not limited to either the main cooling line 420 or the auxiliary cooling line 430, and both lines can move simultaneously.

For example, some of the coolant recovered through the coolant recovery line 410 may be circulated through the main cooling line 420, and other portions may be circulated through the auxiliary cooling line 430.

For this purpose, the operation of the valve (3-way valve) shown in Figure 2 can be fully opened and fully closed, as well as controlling the degree of opening in various ways to control the flow rate of the coolant, and the type and configuration of the valve for this, and the connection with each line. Connection relationships, etc. can be applied in a variety of ways.

In addition, the control unit described above preferentially supplies at least a portion of the low-temperature coolant stored in the auxiliary coolant tank 300 (for example, 90% of the stored low-temperature coolant) to the fuel cell 100 when the heat load of the fuel cell 100 rapidly increases. The coolant recovery line 410 and the auxiliary cooling line 430 can be controlled to circulate during the priority supply time, and when the priority supply time has elapsed, the coolant recovery line 410 and the main cooling line 420 can be controlled to circulate. there is. Here, the priority supply time can be applied in various ways according to the needs of those skilled in the art, and the time required for specific conditions (for example, the time until the coolant heat exchanged in the heat exchanger is supplied to the fuel cell) is met. It can be included.

FIG. 3 is a flowchart showing another embodiment of FIG. 1.

Referring to FIG. 3, the fuel cell cooling method may further include a cooling line return step (S400).

As described above, the cooling line return step (S400) is a process of switching the cooling line from the auxiliary cooling line 430 to the main cooling line 420 when the set priority supply time has elapsed, (b) in Figure 2. This refers to the process of returning from (a).

In other words, the cooling line return step (S400) may mean returning to the normal coolant circulation process once the thermal management problem resulting from a sudden increase in the heat load of the fuel cell 100 is resolved.

Below, we will look in more detail at the technical features of each step shown in FIGS. 1 and 3.

FIG. 4 is a flowchart showing a specific embodiment of step 'S100' shown in FIG. 3, and FIG. 5 is a schematic configuration diagram of a fuel cell cooling system for explaining FIG. 4.

Referring to FIG. 4, the coolant circulation step (S100) is normally performed by circulating the coolant between the fuel cell 100 and the heat exchanger 200 according to the temperature of the coolant discharged from the fuel cell 100. ) By controlling the operation of the fuel cell 100, thermal management of the fuel cell 100 can be performed.

This process is performed when the heat load of the fuel cell 100 is within an allowable range, and the allowable range can be set based on the size of the heat load or the rate of increase of the heat load at the time of measurement.

In addition, the process may be performed by the control unit 500 as shown in FIG. 7, but it is not limited to this, and of course, other configurations or new configurations may be added according to the needs of those skilled in the art.

Looking at FIG. 4 in detail, in the process of normal cooling water circulating through the fuel cell 100 and the heat exchanger 200 (S110), the coolant temperature sensor 210 configured in the coolant recovery line 410 as shown in FIG. 5 The temperature of the coolant discharged from the fuel cell 100 can be measured (S120).

At this time, assuming that the heat load of the fuel cell 100 changes within the allowable range under the precondition, when the size of the heat load of the fuel cell 100 or the temperature of the coolant discharged from the fuel cell is relatively low (S130), When the low-high temperature coolant, which has a relatively low temperature among the high-temperature coolants, is discharged from the fuel cell 100 and flows into the heat exchanger 200 (S141), the heat exchanger 200 heat exchanges the low-temperature coolant with a relatively high temperature among the low-temperature coolants. It can be cooled with high or low temperature coolant.

At this time, since the heat exchanger 200 has relatively little heat energy to be released among the heat energy contained in the coolant, the operation of the coolant pump 220 and the cooling fan 230 shown in FIG. 5 is controlled to control the heat energy to flow into the heat exchanger 200. By reducing the flow rate of the coolant (S142), the amount of heat dissipation in the heat exchanger 200 can be lowered.

The high-low temperature coolant heat-exchanged through this process can be supplied back to the fuel cell 100 (S143).

If the heat load of the fuel cell 100 is relatively high within the allowable range (S130), and high-temperature coolant, which is a relatively high temperature among high-temperature coolants, is discharged from the fuel cell 100, the coolant pump 220 and the cooling By controlling the operation of the fan 230, the flow rate of coolant flowing into the heat exchanger 200 is increased (S512), and as the heat dissipation amount increases, the heat exchanger 200 exchanges heat with the high-temperature coolant to make it relatively low-temperature coolant. It can be cooled with low temperature coolant.

In other words, when relatively high temperature coolant flows in, the heat exchanger 200 controls the operation of the coolant pump 220 and the cooling fan 230 to increase the flow rate, thereby increasing the heat dissipation amount, thereby increasing the relatively low temperature. Cooling water at any temperature can be supplied to the fuel cell 100 (S153).

At this time, the operation of the coolant pump 220 and the cooling fan 230 may be operated linearly according to the temperature of the coolant flowing into the heat exchanger 200, and the degree of increase in the flow rate of the coolant according to the temperature of the coolant is corresponding to Of course, it can be applied in various ways depending on the operating characteristics of the fuel cell and the needs of those skilled in the art.

Additionally, the auxiliary coolant tank 300 can store low-temperature coolant, which has a relatively low temperature among low-temperature coolants.

Accordingly, in the cooling line switching step (S300), when the heat load of the fuel cell 100 rapidly increases and exceeds the allowable range, the low temperature coolant stored in the auxiliary coolant tank 300 is lower than the low temperature coolant heat exchanged in the heat exchanger 200. Low-temperature coolant can be preferentially supplied to the fuel cell 100.

In Figure 5, the unexplained symbol '610' is an ion filter used to lower the electrical conductivity of the coolant, and '600' is a filter chamber in which the ion filter is installed. When the electrical conductivity of the coolant exceeds a certain level, the circulating Electrical conductivity is reduced by circulating cooling water into the filtration chamber 600.

Referring to FIG. 6, in the process of normally circulating coolant through the fuel cell 100 and the heat exchanger 200 (S100), the heat load of the fuel cell 200 is checked (S200) and if the heat load is within the normal range (S310). , the current cooling line can be maintained (S360).

If a sudden increase in heat load is confirmed (S310), the cooling line can be switched from the main cooling line 420 to the auxiliary cooling line 430 (S320).

Thereafter, the low-temperature coolant stored in the auxiliary coolant tank 300 is preferentially supplied to the fuel cell 100 by the set priority supply amount (S330), or when the priority supply time has elapsed, the low-temperature coolant heat-exchanged in the heat exchanger 200 is used as fuel. When supplied to the battery 100 (S340), the cooling line can be redirected from the auxiliary cooling line 430 to the main cooling line 420 (S350).

Referring to FIG. 7, the fuel cell cooling system includes a fuel cell 100, a heat exchanger 200, an auxiliary coolant tank 300, and a control unit 500.

The fuel cell 100 produces electrical energy using hydrogen as a fuel and oxygen in the air, and may include a PEMFC (Proton Exchange Membrane Fuel Cell).

The heat exchanger 200 is configured to supply coolant to the fuel cell 100, and can be connected to the fuel cell 100, the coolant recovery line 410, and the main cooling line 420, and has a wide contact surface with air. can be formed. For example, the heat exchanger 200 may have a shape and structure similar to a plate heat exchanger.

In addition, a coolant temperature sensor 210 that measures the temperature of the coolant flowing into the heat exchanger 200, a coolant pump 220 and a cooling fan 230 that adjust the flow rate and heat dissipation amount of the heat exchanger 200 according to the temperature of the coolant. ) can be configured.

It is natural that this heat exchanger 200 can be configured in various ways, such as the air-cooled type described above, as well as the water-cooled type.

The auxiliary coolant tank 300 is connected to the main cooling line 420 in a parallel structure, and can be connected to the main cooling line 420 through the auxiliary cooling line 430.

At this time, the auxiliary coolant tank 300 is arranged closer to the fuel cell 100 than the heat exchanger 200, based on the time the coolant moves, so that the fuel cell 100 flows faster than the coolant of the heat exchanger 200. It may be configured to supply cooling water to.

Meanwhile, the auxiliary coolant tank 300 may be configured so that the stored coolant is naturally cooled through heat exchange with outside air. For example, it may have a structure similar to a plate heat exchanger in which plates are stacked to increase the contact surface, and a flow path through which coolant flows may be formed inside the plurality of heat exchange plates. Additionally, a passage through which external air passes may be formed in the form of a slit between each heat exchange plate, and may be configured to maximize the heat exchange area between the external air passing through the slit and the coolant flowing through the flow path within the heat exchange plate.

Of course, the structure of the auxiliary coolant tank 300 may be the same or similar to that of the heat exchanger 200, and it is of course not limited to a structure using a heat exchange plate, and can be modified into various shapes and structures.

The control unit 500 receives and confirms the measured values detected by the heat load detection sensor 110 and the coolant temperature sensor 210 configured in the fuel cell 100, and operates a valve (unmarked) such as a three-way valve in response to the measured values. ) and the operation of the coolant pump 220 and cooling fan 230 can be controlled.

For example, the control unit 500 normally supplies coolant heat-exchanged in the heat exchanger 200 to the fuel cell 100, and when the heat load of the fuel cell 100 rapidly increases, the control unit 500 supplies the coolant stored in the auxiliary coolant tank 300 to the fuel cell 100. It can be controlled to supply priority to (100).

In other words, the control unit 500 can control valves, etc. so that coolant circulates through the coolant recovery line 410 and the main cooling line 420 in normal times, and when the heat load of the fuel cell 100 suddenly increases, the coolant recovery line 410 Valves, etc. can be controlled to circulate the auxiliary cooling line 430.

First, referring to (a) of FIG. 8, when the heat load of the fuel cell 100 suddenly increases, the coolant cooled in the heat exchanger 200 (coolant heat exchanged before detection of the heat load sudden increase and the auxiliary coolant tank 300) are cooled in the heat exchanger 200 according to the size of the heat load. ) can be mixed at a certain ratio and supplied to the fuel cell 100. At this time, the mixing ratio of the two coolants can be determined in response to the size of the detected heat load.

Referring to (b) of FIG. 8, between the coolant recovery line 410 and the main cooling line 420, there is a bypass for directly supplying the high-temperature coolant discharged from the fuel cell 100 to the auxiliary coolant tank 300. A pass line 440 may be further configured.

Accordingly, when the heat load of the fuel cell 100 increases rapidly, the coolant stored in the auxiliary coolant tank 300 can be supplied to the fuel cell 100, and the high-temperature coolant discharged from the fuel cell 100 is sent to the bypass line 400. ) can be stored in the auxiliary coolant tank 300.

Afterwards, when the normal circulation mode is switched and the coolant heat-exchanged in the heat exchanger 200 is supplied to the fuel cell 100, the high-temperature coolant stored in the auxiliary coolant tank 300 exchanges heat with the outside air through natural convection to provide low-temperature coolant. can be cooled.

Referring to FIG. 9, the auxiliary coolant tank 300 may be arranged in parallel with the heat exchanger 200 and connected to the coolant recovery line 410 and the main cooling line 420.

Looking more specifically, the coolant recovery line 410 may be configured to allow high-temperature coolant that has absorbed heat generated in the fuel cell 100 to move to at least one of the heat exchanger 200 and the auxiliary coolant tank 300.

In addition, the main cooling line 420 may be configured to move the low-temperature coolant heat-exchanged in the heat exchanger 200 to the fuel cell 100, and the auxiliary cooling line 430 may be configured to move the low-temperature coolant stored in the auxiliary coolant tank 300. may be configured to move to the fuel cell 100.

Accordingly, the control unit 500 can control the coolant to circulate through the coolant recovery line 410 and the main cooling line 420 as shown in (a) of FIG. 9 under normal circumstances, and when the heat load of the fuel cell 100 suddenly increases. As shown in (b) of FIG. 9, the coolant recovery line 410 and the auxiliary cooling line 430 can be controlled to circulate.

In addition, the control unit 500 operates when at least a portion of the low-temperature coolant stored in the auxiliary coolant tank 300 is discharged, or when a certain amount of high-temperature coolant recovered from the fuel cell 100 flows into the auxiliary coolant tank 300, or When the coolant temperature inside the auxiliary coolant tank 300 reaches a certain temperature due to the high-temperature coolant recovered from the fuel cell 100, it is determined that the priority supply time has elapsed, and as shown in (a) of FIG. 9 The cooling line can be redirected (returned).

Above, the fuel cell cooling method and system according to the present invention have been described. Those skilled in the art will understand that the technical configuration of the present invention can be implemented in other specific forms without changing the technical idea or essential features of the present invention.

Therefore, the embodiments described above should be understood as illustrative in all respects and not restrictive.

[Explanation of symbols]

100: fuel cell 110: heat load detection sensor

200: heat exchanger 210: coolant temperature sensor

220: Cooling water pump 230: Cooling fan

300: Auxiliary coolant tank

410: Cooling water recovery line 420: Main cooling line

430: Auxiliary cooling line 440: Bypass line

500: Control unit

600: Filter chamber 610: Ion filter

The present invention can be used in the fuel cell field, fuel cell thermal management field, fuel cell cooling field, fuel cell cooling system field, fuel cell coolant control field, as well as similar or related fields, and can be applied to products and systems in the field. Reliability and competitiveness can be improved.

Claims

A cooling water circulation step in which, when high-temperature coolant is normally discharged from the fuel cell, a heat exchanger configured in the main cooling line cools the high-temperature coolant into low-temperature coolant and supplies it to the fuel cell;

A heat load monitoring step of monitoring changes in heat load of the fuel cell; and

When the heat load of the fuel cell rapidly increases compared to normal times, an auxiliary coolant tank is configured in the main cooling line to supply the low-temperature coolant stored in the auxiliary coolant tank to the fuel cell preferentially compared to the low-temperature coolant supplied from the heat exchanger to the fuel cell. Including a cooling line conversion step of converting the cooling line to a cooling line.

Fuel cell cooling method.
According to clause 1,

After the cooling line switching step,

Characterized in that it further comprises a cooling line return step of switching the cooling line from the auxiliary cooling line to the main cooling line when the set priority supply time has elapsed.

Fuel cell cooling method.
According to clause 2,

The coolant circulation step is,

Normally, when the heat load of the fuel cell is relatively low within the allowable range, low-high temperature coolant, which has a relatively low temperature among the high-temperature coolants, is discharged from the fuel cell, and the heat exchanger exchanges heat with the low-temperature coolant to produce relatively high temperature among the low-temperature coolants. Cooled with high-low temperature coolant,

When the heat load of the fuel cell is relatively high within the allowable range, high-temperature coolant, which has a relatively high temperature among the high-temperature coolants, is discharged from the fuel cell, and the heat exchanger exchanges heat with the high-temperature coolant to lower the temperature, which is relatively low among the low-temperature coolants. Characterized by cooling with low-temperature coolant,

Fuel cell cooling method.
According to clause 3,

The auxiliary coolant tank is,

Among the low-temperature coolants, low-temperature coolant with a relatively low temperature is stored,

The cooling line switching step is,

When the heat load of the fuel cell rapidly increases and exceeds the allowable range, the low-temperature coolant stored in the auxiliary coolant tank is preferentially supplied to the fuel cell rather than the low-temperature coolant exchanged in the heat exchanger.

Fuel cell cooling method.
According to clause 4,

The cooling line return step is,

When the low-temperature coolant stored in the auxiliary coolant tank is preferentially supplied to the fuel cell according to the set priority supply amount, or when the priority supply time has elapsed and the low-temperature coolant heat-exchanged in the heat exchanger is supplied to the fuel cell, the cooling line is connected to the auxiliary cooling line. Characterized by re-conversion to the main cooling line,

Fuel cell cooling method.
fuel cell;

a heat exchanger configured to supply cooling water to the fuel cell;

an auxiliary coolant tank configured to supply coolant to the fuel cell faster than the coolant of the heat exchanger; and

A control unit that normally supplies coolant heat-exchanged in the heat exchanger to the fuel cell and controls the coolant stored in the auxiliary coolant tank to be supplied to the fuel cell first when the heat load of the fuel cell suddenly increases.

Fuel cell cooling system.
According to clause 6,

a coolant recovery line configured to allow high-temperature coolant absorbing heat generated from the fuel cell to move to at least one of a heat exchanger and an auxiliary coolant tank;

a main cooling line configured to move the low-temperature cooling water heat-exchanged in the heat exchanger to the fuel cell; and

It includes an auxiliary cooling line configured to move the low-temperature coolant stored in the auxiliary coolant tank to the fuel cell,

The control unit,

Characterized in that the coolant is controlled to circulate through the coolant recovery line and the main cooling line in normal times, and is controlled to circulate through the coolant recovery line and the auxiliary cooling line when the heat load of the fuel cell suddenly increases.

Fuel cell cooling system.
According to clause 7,

The auxiliary cooling line is,

The low-temperature coolant heat-exchanged in the heat exchanger is configured to be supplied to the auxiliary coolant tank,

The control unit,

When the heat load of the fuel cell suddenly increases, the coolant stored in the auxiliary coolant tank is first supplied to the fuel cell, and at the same time, the coolant heat exchanged in the heat exchanger is supplied to the auxiliary coolant tank,

Fuel cell cooling system.
According to clause 7,

The control unit,

When the heat load of the fuel cell suddenly increases, the coolant recovery line and the auxiliary cooling line are controlled to circulate during the priority supply time during which at least a portion of the low-temperature coolant stored in the auxiliary coolant tank is preferentially supplied to the fuel cell, and when the priority supply time elapses, the coolant is supplied. Characterized by controlling the recovery line and main cooling line to circulate,

Fuel cell cooling system.
According to clause 9,

The control unit,

At least a portion of the low-temperature coolant stored in the auxiliary coolant tank is discharged,

A certain amount of high-temperature coolant recovered from the fuel cell flows into the auxiliary coolant tank, or

When the coolant temperature inside the auxiliary coolant tank reaches a certain temperature,

Characterized in that it is determined that the priority supply time has elapsed,

Fuel cell cooling system.