KR20230147349A - Fuel cell system and thermal management control method thereof - Google Patents

Abstract

A fuel cell system according to an embodiment of the present invention includes a plurality of electrical components, a radiator disposed on a cooling line through which coolant circulating through the plurality of electrical components is set to cool the coolant, and a radiator on the cooling line. It includes a pump disposed in and flows the coolant to the electrical components, wherein the plurality of electrical components are arranged in parallel in one section of the cooling line between the outlet of the pump and the inlet of the radiator.

Description

Fuel cell system and its thermal management control method {FUEL CELL SYSTEM AND THERMAL MANAGEMENT CONTROL METHOD THEREOF}

The present invention relates to a fuel cell system and its thermal management control method.

A fuel cell system can generate electrical energy using a fuel cell stack. For example, if hydrogen is used as a fuel for a fuel cell stack, it can be an alternative to solving global environmental problems, so continuous research and development is being conducted on fuel cell systems.

The fuel cell system consists of a fuel cell stack that generates electrical energy, a fuel supply device that supplies fuel (hydrogen) to the fuel cell stack, an air supply device that supplies oxygen from the air, an oxidizing agent necessary for electrochemical reactions, to the fuel cell stack, and fuel. It may include a thermal management system (TMS) that removes reaction heat from the cell stack to the outside of the system, controls the operating temperature of the fuel cell stack, and performs a water management function.

The thermal management system is a type of cooling device that maintains an appropriate temperature (e.g., 60 to 70°C) by circulating antifreeze, which acts as coolant, into the fuel cell stack. It includes a TMS line through which the coolant circulates, and a reservoir where the coolant is stored. , a pump that circulates the coolant, an ion filter that removes ions contained in the coolant, and a radiator that emits heat from the coolant to the outside. Additionally, the thermal management system may include a heater that heats coolant, and an air conditioning unit (e.g., a heating heater) that uses coolant to cool or heat the interior of a device (e.g., vehicle) containing a fuel cell system. . The thermal management system can maintain the appropriate temperature of not only the fuel cell stack but also the vehicle's electrical components.

There are a variety of electrical components such as BHDC (bi-directional high voltage DC-DC converter). Since these electrical components are generally cooled by water cooling, it is important to select the appropriate flow rate and coolant entry temperature for each electrical component. However, due to the miniaturization and limited capacity of the cooling water pump (Coolant Pump, CPP) installed in the electrical equipment cooling line, it is difficult to secure the cooling flow rate of the electrical equipment at the target flow rate.

One purpose of the present invention is to provide a fuel cell system and a thermal management method thereof that can secure the coolant flow rate flowing into electrical components at the target flow rate when the thermal management system is operating.

In addition, another object of the present invention is to provide a fuel cell system and a heat management method thereof that can resolve the flow imbalance between each flow path due to the difference in pressure drop of each electrical component in the process of configuring electrical component cooling lines in parallel. there is.

In addition, another object of the present invention is to improve the cooling efficiency of electrical equipment by installing a differential pressure regulator in some flow paths, thereby increasing the flow rate of the corresponding flow path by adjusting the differential pressure control valve when the components of specific electrical equipment overheat. To provide a battery system and its heat management method.

The technical problems of the present invention are not limited to the technical problems mentioned above, and other technical problems not mentioned will be clearly understood by those skilled in the art from the description below.

A fuel cell system according to an embodiment of the present invention includes a plurality of electrical components, a radiator disposed on a cooling line through which coolant circulating through the plurality of electrical components is set to cool the coolant, and a radiator on the cooling line. It includes a pump disposed in and flows the coolant to the electrical components, wherein the plurality of electrical components are arranged in parallel in one section of the cooling line between the outlet of the pump and the inlet of the radiator.

In one embodiment, the cooling line branches into a first flow path and a second flow path at a first point on the cooling line connected to the outlet of the pump, and the first flow path branches at a second point on the cooling line connected to the inlet of the radiator. It is characterized in that the flow path and the second flow path are combined.

In one embodiment, the first flow path and the second flow path include at least one electrical component arranged in series.

In one embodiment, the fuel cell system according to the present invention further includes a differential pressure regulator disposed in one of the first flow path and the second flow path to adjust the flow rate of coolant flowing along the corresponding flow path. Do it as

In one embodiment, the differential pressure regulator is characterized in that it controls the flow rate of coolant flowing into the corresponding flow path by adjusting the differential pressure control valve according to a reference pressure set in response to the flow path in which the differential pressure regulator is disposed.

In one embodiment, the fuel cell system according to the present invention further includes a control unit that controls the differential pressure regulator according to the temperature of the inlet coolant of each electrical component disposed on the first flow path and the second flow path. do.

In one embodiment, the controller opens the differential pressure control valve to increase the coolant flow rate of the first flow path when the inlet coolant temperature of at least one of the electrical components disposed on the first flow path exceeds the target coolant temperature. A first control signal for upwardly adjusting the volume is transmitted to the differential pressure regulator.

In one embodiment, the control unit opens the differential pressure control valve to reduce the coolant flow rate of the first flow path when the inlet coolant temperature of at least one of the electrical components disposed on the second flow path exceeds the target coolant temperature. A second control signal for downwardly adjusting the volume is transmitted to the differential pressure regulator.

In one embodiment, the fuel cell system according to the present invention further includes a temperature sensor disposed at the inlet of the electrical component on the first flow path and the second flow path, respectively, to measure the coolant temperature at the inlet of the corresponding electric component. Do it as

In one embodiment, the differential pressure regulator is disposed on a flow path between the first point and the electrical component, and is disposed close to the first point.

In one embodiment, the cooling line is branched into at least three flow paths between the first point and the second point.

In addition, the thermal management control method of a fuel cell system according to an embodiment of the present invention includes a first flow path and a second flow path branched from a section of a cooling line through which coolant circulating through a plurality of electrical components is disposed. It includes flowing coolant to each electrical component and adjusting the flow rate of coolant flowing into the first flow path and the second flow path according to the inlet coolant temperature of each electrical component.

In one embodiment, the method according to the present invention further includes the step of checking the inlet coolant temperature of each electrical component disposed on the first flow path and the second flow path.

In one embodiment, the step of controlling the coolant flow rate includes controlling a differential pressure regulator disposed on the first flow path according to the inlet coolant temperature of each electrical component.

In one embodiment, the step of controlling the differential pressure regulator includes: when the inlet coolant temperature of at least one of the electrical components disposed on the first flow path exceeds the target coolant temperature, the coolant flow rate of the first flow path increases. It is characterized in that it includes the step of upwardly adjusting the opening amount of the differential pressure control valve.

In one embodiment, the step of controlling the differential pressure regulator includes: when the inlet coolant temperature of at least one of the electrical components disposed on the second flow path exceeds the target coolant temperature, the coolant flow rate of the first flow path is reduced. It is characterized in that it includes the step of downwardly adjusting the opening amount of the differential pressure control valve.

According to embodiments of the present invention, there is an effect of securing the coolant flow rate flowing into the electrical equipment as the target flow rate by configuring the electrical equipment cooling lines in parallel when the thermal management system is operating.

In addition, according to embodiments of the present invention, in the process of configuring electrical equipment cooling lines in parallel, there is an effect of resolving the flow imbalance between each flow path due to the difference in pressure drop of each electrical equipment.

In addition, according to embodiments of the present invention, by installing a differential pressure regulator in some of the flow paths, the cooling efficiency of the electric equipment can be improved by increasing the flow rate of the corresponding flow path by adjusting the differential pressure control valve when the component of a specific electric equipment overheats. there is.

1 is a diagram illustrating a fuel cell system according to an embodiment of the present invention.
Figure 2 is a diagram showing a fuel cell system according to another embodiment of the present invention.
Figure 3 is a diagram illustrating a fuel cell system according to various further embodiments of the present invention.
Figure 4 is a diagram showing the connection relationship of cooling lines for electrical equipment according to an embodiment of the present invention.
FIG. 5 is a diagram illustrating an embodiment of the flow distribution operation of the electrical equipment cooling line according to FIG. 4.
Figure 6 is a diagram showing the connection relationship of cooling lines for electrical equipment according to another embodiment of the present invention.
Figure 7 is a diagram illustrating a control block diagram of a fuel cell system according to an embodiment of the present invention.
FIG. 8 is a diagram illustrating the operation flow of a thermal management control method of a fuel cell system according to an embodiment of the present invention.

Hereinafter, some embodiments of the present invention will be described in detail through illustrative drawings. When adding reference numerals to components in each drawing, it should be noted that identical components are given the same reference numerals as much as possible even if they are shown in different drawings. Additionally, when describing embodiments of the present invention, if detailed descriptions of related known configurations or functions are judged to impede understanding of the embodiments of the present invention, the detailed descriptions will be omitted.

In describing the components of the embodiment of the present invention, terms such as first, second, A, B, (a), and (b) may be used. These terms are only used to distinguish the component from other components, and the nature, sequence, or order of the component is not limited by the term. Additionally, unless otherwise defined, all terms used herein, including technical or scientific terms, have the same meaning as generally understood by a person of ordinary skill in the technical field to which the present invention pertains. Terms defined in commonly used dictionaries should be interpreted as having a meaning consistent with the meaning in the context of the related technology, and should not be interpreted in an ideal or excessively formal sense unless explicitly defined in the present application. No.

1 to 3 show fuel cell systems according to various embodiments. FIG. 1 is a diagram showing a fuel cell system according to an embodiment of the present invention, and FIGS. 2 and 3 show other embodiments. This is a diagram showing a fuel cell system.

Referring to FIG. 1, the fuel cell system for a vehicle is configured such that the first coolant circulates through the fuel cell stack 10 of the vehicle and passes through the first cooling line 110 and power electronic parts 200 of the vehicle. It may include a second cooling line 120 through which a second coolant is circulated. In an embodiment, the fuel cell system may further include a heat exchanger 300 that exchanges heat between the first coolant and the second coolant, but may be omitted.

The fuel cell system forms a heating loop (heating circulation path, or heating loop) with the first cooling line 110, or a first connection line 130 to form a cooling line with the first cooling line 110, It may include a second connection line 150 and a third connection line 140. The first coolant may be cooled or heated while circulating through the first connection line 130, the second connection line 150, or the third connection line 140.

On the first cooling line 110 through which the first coolant circulates, a fuel cell stack 10, a first valve 20, a first pump 30, a second valve 40, and a first radiator 60 are installed. can be placed.

The fuel cell stack 10 (or may be referred to as a 'fuel cell') is a structure capable of producing electricity through a redox reaction of fuel (eg, hydrogen) and an oxidizing agent (eg, air). can be formed. For example, in the fuel cell stack 10, hydrogen as a fuel and air (oxygen) as an oxidizing agent meet to cause a reaction to produce water. At this time, the movement of hydrogen ions causes a flow of electrons through the external conductor, Current can be generated through this flow of electrons.

The first valve 20 may change the flow path of the first coolant on the first cooling line 110 to the first connection line 130 or the fuel cell stack 10 where the heater 50 is disposed. The first valve 20 may include various valve means that can selectively change the flow path of the first coolant. For example, the first valve 20 may be a three-way valve. In this case, the first valve 20 includes a first port 21 connected to the first cooling line 110 so that the first coolant pumped by the first pump 30 flows in, and a first valve 20. A second port 22 connected to the first cooling line 110 so that the first coolant passing through flows into the fuel cell stack 10, and a third port connected to one end of the first connection line 130 ( 23) may be included. By opening and closing the second port 22 and the third port 23 of the first valve 20, the flow path of the first coolant is connected to the heater 50 or the fuel cell stack 10 of the first connection line 130. can be converted to

The first connection line 130 may form a heating loop (heating circulation path) with the first cooling line 110 to heat the first coolant. For example, the first coolant flowing along the first connection line 130 may be heated while passing through the heater 50 installed in the first connection line 130.

The first pump 30 may be set to forcibly flow the first coolant. The first pump 30 may include various means for pumping the first coolant, and the type and number of the first pump 30 are not limited in this document.

The second valve 40 may change the flow path of the first coolant on the first cooling line 110 to the first radiator 60 or the fuel cell stack 10. For example, the second valve 40 is provided on the first cooling line 110 to be located between the first pump 30 and the first radiator 60, and is connected to one end of the third connection line 140. And it may be connected to the outlet of the first radiator 60. The second valve 40 may include various valve means that can selectively switch the flow path of the first coolant to the first radiator 60 or the fuel cell stack 10. For example, the second valve 40 may be a four-way valve or a three-way valve. In the case of a three-way valve, the second valve 40 is connected to the first port 41 connected to the third connection line 140, and the first cooling line 110 so that the first coolant passing through the first radiator 60 flows in. ) and a third port 44 connected to the first cooling line 110 so that the first coolant flows into the first pump 30, and a second port 44 that is a four-way valve. The valve 40 may further include a third port 43 connected to one end of the second connection line 150. By opening and closing the first port 41 or the second port 42 of the second valve 40, the flow path of the first coolant can be switched to the first radiator 60 or the fuel cell stack 10. Depending on the opening amount of the second valve 40, part of the first coolant may pass through the first radiator 60 and the remaining part may flow along the third connection line 140.

The second connection line 150 may be provided with an ion filter 95 that filters ions of the first coolant that has passed through the air conditioning unit 90. If the electrical conductivity of the first coolant increases due to corrosion or exudation of the system, electricity flows into the first coolant, causing a problem in which the fuel cell stack 10 is short-circuited or current flows toward the first coolant. , the first coolant must be able to maintain low electrical conductivity. The ion filter 95 may be set to remove ions contained in the first coolant so that the electrical conductivity of the first coolant can be maintained below a certain level.

The third connection line 140 may form a cooling loop with the first cooling line 110 to cool the first coolant. As an example, one end of the third connection line 140 is connected to the first cooling line 110 between the first pump 30 and the first radiator 60, and the other end of the third connection line 140 may be connected to the first cooling line 110 between the coolant outlet of the fuel cell stack 10 and the first radiator 60.

The first radiator 60 may be set to cool the first coolant. The first radiator 60 may be formed in various structures capable of cooling the first coolant, and the present invention is not limited or limited by the type and structure of the first radiator 60. The first radiator 60 may be connected to the first reservoir 62 where the first coolant is stored.

The fuel cell system includes a first temperature sensor 112 that measures the temperature of the first coolant between the fuel cell stack 10 and the first point (the first valve 20), and another sensor of the first connection line 130. It includes a second temperature sensor 114 that measures the temperature of the first coolant between one end and the first pump 30, and a third temperature sensor 116 that measures the temperature of the first coolant in the heater 50. can do. The fuel cell system determines the inflow rate of the first coolant flowing into the fuel cell stack 10 based on the temperature measured by the first temperature sensor 112, the second temperature sensor 114, and the third temperature sensor 116. can be controlled. For example, if the measured temperature of the first coolant circulating along the first cooling line 110 is lower than a preset target temperature, the inflow rate of the first coolant may be controlled to be lower than the preset set flow rate.

The second cooling line 120 is configured to pass through the vehicle's electrical components 200, and the second coolant can circulate along the second cooling line 120. Here, the electrical components 200 of the vehicle can be understood as components that use the vehicle's power source as an energy source, and the present invention is not limited or limited by the type and number of the electrical components 200.

As an example, the electrical components 200 include an air compressor (ACP) that compresses the air supplied to the fuel cell stack 10, and an air compressor (ACP) provided between the fuel cell stack 10 and the vehicle's high-voltage battery (not shown). BHDC (bi-directional high voltage DC-DC converter), BPCU (blower pump control unit) that controls a blower (not shown) that supplies external air for driving the fuel cell stack 10, air cooler, It may include at least one of a low-voltage DC-DC converter (LDC) and a DC-DC buck/boost converter that converts high-voltage direct current supplied from a high-voltage battery into low-voltage direct current, and various other components. may be included.

A second pump 205 may be disposed on the second cooling line 120 to forcibly flow the second coolant. The second pump 205 may include a pumping means capable of pumping the second coolant, and the type and characteristics of the second pump 205 are not limited or limited.

A second radiator 70 may be disposed on the second cooling line 120 to cool the second coolant. The second radiator 70 may be formed in various structures capable of cooling the second coolant, and the type and structure of the second radiator 70 are not limited or limited. The second radiator 70 may be connected to the second reservoir 72 where the second coolant is stored.

In an embodiment, the first radiator 60 and the second radiator 70 may be configured to be cooled simultaneously by one cooling fan 80 as shown in FIG. 1. For example, the first radiator 60 and the second radiator 70 are arranged side by side, and the cooling fan 80 may be set to blow outside air to the first radiator 60 and the second radiator 70. . By allowing the first radiator 60 and the second radiator 70 to be cooled simultaneously by one cooling fan 80, the structure of the fuel cell system can be simplified and design freedom and space utilization can be improved. , power consumption for cooling the first radiator 60 and the second radiator 70 can be minimized.

In another embodiment, as shown in FIG. 2, the first cooling fan 80 for cooling the first radiator 60 and the second cooling fan 85 for cooling the second radiator 70 are arranged separately. It can be. In this case, the fuel cell system may exclude parameters related to the thermal load of the electrical component 200 when controlling the rotation speed of the first cooling fan 80. The embodiments described below are based on the fuel cell system structure of FIG. 1, but the same principles can be applied to the fuel cell system structure of FIG. 2.

Referring again to FIG. 1, the heat exchanger 300 may be set to exchange heat between the first coolant and the second coolant. When the heat exchanger 300 is included, the first cooling line 110 and the second cooling line 120 form a TMS (thermal management system) line through which the first coolant and the second coolant can flow while performing heat exchange. It can be configured, and in this case, the first coolant or the second coolant can be used as a coolant (cooling medium) or heat medium on the TMS line. For example, since the temperature of the second coolant that cools the electrical components is relatively lower than the temperature of the first coolant that cools the fuel cell stack 10, the fuel cell system exchanges heat between the first coolant and the second coolant. By doing so, the temperature of the first coolant can be lowered without increasing the capacity of the first radiator 60 and the cooling fan 80, the cooling efficiency of the fuel cell stack 10 can be improved, and safety and reliability can be improved. Beneficial effects can be achieved by improving

In an embodiment, the heat exchanger 300 is connected to the first cooling line 110 between the outlet of the first radiator 60 and the fuel cell stack 10, and the second cooling line 120 is connected to the heat exchanger ( The outlet of the second radiator 70 and the electrical components can be connected via 300). For example, the first coolant may flow along the heat exchanger 300 connected to the first cooling line 110, and the second cooling line 120 is exposed to the first coolant (e.g., the first coolant It may pass through the interior of the heat exchanger 300 to flow along the circumference of the second cooling line 120. In this way, the fuel cell system can lower the temperature of the first coolant flowing into the fuel cell stack 10 by mutual heat exchange between the first coolant and the second coolant. The first temperature of the first coolant passing through the first radiator 60 is higher than the second temperature of the second coolant passing through the second radiator 70, and the first temperature of the first coolant passing through the heat exchanger 300 is higher than the second temperature of the second coolant passing through the heat exchanger 300. The third temperature may be formed lower than the first temperature. For example, the first temperature of the first coolant may be approximately 10°C higher than the second temperature of the second coolant, and the third temperature of the first coolant passing through the heat exchanger 300 (heat exchanged with the second coolant) may be formed to be 1°C lower than the first temperature.

The heat exchanger 300 according to FIGS. 1 and 2 is disposed separately from the first radiator 60, but in another embodiment, the heat exchanger 300 may be directly connected to the first radiator 60 as shown in FIG. 3. there is. For example, the heat exchanger 300 may be connected to a designated location (upper left portion) of the first radiator 60, but is not limited thereto.

Figure 4 is a diagram showing the arrangement structure of electrical components of the second cooling line according to an embodiment of the present invention, and Figure 5 is a diagram showing an embodiment of the flow distribution operation of the second cooling line according to Figure 4. In addition, Figure 6 is a diagram showing the arrangement structure of electrical components in the second cooling line according to another embodiment of the present invention.

Referring to FIG. 4, when the second radiator 70 on the second cooling line cools the second coolant, the second pump 205 forces the second coolant cooled by the second radiator 70 to flow. Let it flow into the electrical components (200). Here, the inlet of the second pump 205 may be defined as the inlet through which the second coolant flows into the second pump 205. In addition, the outlet of the second pump 205 is the inlet through which the second coolant flows into the second pump 205. It can be defined as an outlet through which the second coolant is discharged.

The electrical component 200 may be connected to the second cooling line 120 between the outlet of the second pump 205 and the inlet of the second radiator 70. As an example, the electrical component 200 may include at least one of an air compressor (ACP) 220, a BHDC (230), an air cooler (ACL) 240, and a converter (DC-DC converter) 250. .

The second cooling line 120 branches into a plurality of flow paths, for example, a first flow path 410 and a second flow path 420, at a first point after the outlet of the second pump 205, and includes a plurality of flow paths. Can be coupled at a second point before the inlet of the second radiator 70.

Accordingly, the plurality of electrical components 200 may be disposed in either the first flow path 410 or the second flow path 420. At this time, the plurality of electrical components 200 may be evenly distributed in the first flow path 410 and the second flow path 420 and arranged in parallel, respectively. As an example, an air compressor (ACP) 220 and a BHDC 230 will be placed on the first flow path 410, and an air cooler (ACL) 240 and a converter 250 will be placed on the second flow path 420. You can. Although the embodiment of FIG. 4 shows an embodiment in which four electrical components 200 are arranged, the number and type are not limited to any one.

A differential pressure regulator 210 may be additionally provided in either the first flow path 410 or the second flow path 420. As an example, the differential pressure regulator 210 may be provided on the first flow path 410. At this time, the differential pressure regulator 210 may be disposed between the point where the second cooling line 120 branches off to the first flow path 410 and the electrical component 200. Here, the differential pressure regulator 210 is located at a point where the second cooling line 120 branches off into the first flow path 410 to facilitate flow distribution between the first flow path 410 and the second flow path 420. It can be placed in a nearby location.

The differential pressure regulator 210 may open the differential pressure control valve 100% during initial operation, but the differential pressure control valve may be opened according to a preset reference pressure for equal distribution of coolant between the first flow path 410 and the second flow path 420. can be adjusted.

As an example, since the differential pressure regulator 210 is installed on the first flow path 410, when the differential pressure control valve is adjusted according to the predefined reference pressure for the first flow path 410, the second cooling line ( Among the coolant flowing in through 120), the amount of coolant adjusted by the differential pressure regulator 210 may flow into the first flow path 410, and the remaining coolant may flow into the second flow path 420.

As shown in FIG. 5, assuming that the flow rate of the coolant flowing through the second pump 205 along the second cooling line 120 is K [LPM], the reference pressure of the first flow path 410 ( P _A ) is A [bar], and the reference pressure (P _B ) of the second flow path 420 may be defined as B [bar].

Accordingly, when coolant flows in through the first flow path 410, the differential pressure regulator 210 adjusts the differential pressure control valve so that the pressure of the coolant flowing into the first flow path 410 is A [bar]. Accordingly, the amount of coolant flowing into the first flow path 410 is 'K It can flow into ACP) (220) and BHDC (230).

Meanwhile, as the pressure of the first flow path 410 is adjusted by the differential pressure regulator 210, coolant as much as 'K x A / (A + B)' flows into the second flow path 420, and the second flow path ( The coolant flowing into 420) may flow into the air cooler (ACL) 240 and the converter 250 along the second flow path 420.

The fuel cell system can check the inlet coolant temperature of each electrical component 200 when the thermal management system is operating. As an example, the inlet coolant temperature of each electrical component 200 may be received from a temperature sensor installed at the inlet through which the coolant flows into each electrical component 200.

The fuel cell system can determine whether flow rate adjustment of some or all flow paths is necessary based on the inlet coolant temperature of each electrical component 200. As an example, when the inlet coolant temperature confirmed from at least one of the electrical components 200 disposed on the first flow path 410 exceeds the target coolant temperature, the fuel cell system operates under a differential pressure installed on the first flow path 410. The opening amount of the differential pressure control valve of the regulator 210 is increased by a predetermined amount. By increasing the opening amount of the differential pressure control valve by a predetermined amount, the coolant flow rate flowing in along the first flow path 410 increases, making it possible to lower the inlet coolant temperature of the electrical components on the first flow path 410 to below the target coolant temperature. I do it.

Meanwhile, when the inlet coolant temperature confirmed from at least one of the electrical components 200 disposed on the second flow path 420 exceeds the target coolant temperature, the fuel cell system uses a differential pressure regulator installed on the first flow path 410. Reduce the opening amount of the differential pressure control valve (210) by a predetermined amount. When the opening amount of the differential pressure control valve is reduced by a predetermined amount, the flow rate of coolant flowing in along the first flow path 410 decreases, and as a result, the flow rate of coolant flowing in along the second flow path 420 increases and the flow rate of coolant flowing in along the second flow path 420 increases. 420) It is possible to lower the inlet coolant temperature of the upper electrical component 200 to below the target coolant temperature.

Here, when the electrical components 200 are arranged in series on one flow path, a pressure loss relative to the coolant flow rate occurs every time the coolant moving along the corresponding flow path passes through the electrical components 200.

On the other hand, when the electrical components 200 are distributed and arranged in parallel across a plurality of passages, the pressure loss due to the coolant flow rate can be minimized by reducing the number of electrical components 200 arranged in series in one passage. The pressure drop of the total coolant flow rate moving along the second cooling line 120 can be reduced. In this way, when the pressure drop of the entire coolant flow rate is lowered, the hydraulic water flow resistance of the entire system is reduced, and a higher pressure flow rate can be achieved by using the second pump 205 of the same performance, so the second cooling line 120 ) Not only does the pump efficiency increase, but it also has the effect of increasing the maximum flow rate. As a result, the cooling performance of the electrical component 200 can be stably guaranteed.

In the embodiment of FIG. 4, the second cooling line 120 is branched into two flow paths, that is, the first flow path 410 and the second flow path 420, but in another embodiment, the second cooling line 120 is divided into two flow paths. As shown in Figure 6, it may be branched into three flow paths, that is, a first flow path 410, a second flow path 420, and a third flow path 430. However, it is not limited to this, and may branch into more flow paths depending on the embodiment. In this case, the electrical components 200 further include an air compressor (ACP) 220, a BHDC (230), an air cooler (ACL) 240, and a converter 250, as well as a BPCU (260) and an LDC (270). can do.

As shown in FIG. 6, when the second cooling line 120 is branched into three flow paths, differential pressure regulators 210 and 215 may be installed in each of the two flow paths. For example, a first differential pressure regulator 210 may be installed in the first flow path 410, and a second differential pressure regulator 215 may be installed in the third flow path 430 (or the second flow path 420).

In this case, the first and second differential pressure regulators (210, 215) branch from the second cooling line 120 to the first flow path 410 and the third flow path 430, similar to the embodiment of FIG. It can be placed between the point and the electrical component 200.

Here, the first and second differential pressure regulators 210 and 215 are connected to the first flow path ( 410) and may be placed close to the point where it branches off into the third flow path 430. The first and second differential pressure regulators 210, 215 can open the differential pressure control valve 100% during initial operation, but in order to equalize the distribution of coolant between the first flow path 410 and the third flow path 430, The differential pressure control valve can be adjusted according to the equal distribution standard.

As an example, the first differential pressure regulator 210 adjusts the differential pressure control valve according to a predefined reference pressure for the first flow path 410. Additionally, the second differential pressure regulator 215 adjusts the differential pressure control valve according to a predefined reference pressure for the third flow path 430. At this time, among the coolant flowing through the second cooling line 120, the amount of coolant adjusted by the first and second differential pressure regulators 210 and 215 flows into the first flow path 410 and the third flow path 430. And, the remaining coolant may flow into the second flow path 420.

Figure 7 is a diagram illustrating a control block diagram of a fuel cell system according to an embodiment of the present invention. Referring to FIG. 7, the fuel cell system according to the present invention may include a plurality of temperature sensors 711 to 719 and a control unit 720.

Here, the plurality of temperature sensors 711 to 719 may be disposed at the inlet of each electrical component 200 and may be sensors that measure the temperature of the coolant at the inlet of the electrical component 200 at the corresponding location. When the temperature of the inlet coolant of the electrical component 200 is measured, each of the temperature sensors 711 to 719 may transmit the measured temperature information to the control unit 720.

The control unit 720 may be a hardware device such as a processor or central processing unit (CPU), or a program implemented by the processor. The control unit 720 is connected to each component of the fuel cell system and can perform overall functions related to the operation of the thermal management system of the fuel cell system.

The control unit 720 may determine an operation for thermal management control of the fuel cell system according to the inlet coolant temperature of the electrical component 200 received from each of the plurality of temperature sensors 711 to 719.

As an example, the control unit 720 controls each electrical component when the coolant moving along the second cooling line 120 branches into a plurality of flow paths, for example, the first flow path 410 and the second flow path 420. Based on the inlet coolant temperature of (200), it can be determined whether the flow rate of some or all flow paths needs to be adjusted.

When the inlet coolant temperature confirmed from at least one of the electrical components 200 disposed on the first flow path 410 exceeds the target coolant temperature, the control unit 720 operates a differential pressure regulator installed on the first flow path 410 ( 210) can be controlled to increase the opening amount of the differential pressure control valve by a predetermined amount. At this time, the control unit 720 may transmit a first control signal that upwardly adjusts the opening amount of the differential pressure control valve to the differential pressure regulator 210. Accordingly, the differential pressure regulator 210 may adjust the opening amount of the differential pressure control valve upward by a predetermined amount based on the first control signal from the control unit 720. Here, when the opening amount of the differential pressure control valve is adjusted upward by a predetermined amount, the coolant flow rate flowing in along the first flow path 410 increases and the inlet coolant temperature of the electrical components on the first flow path 410 is lowered to below the target coolant temperature. It becomes possible to do so.

Meanwhile, when the inlet coolant temperature confirmed from at least one of the electrical components 200 disposed on the second flow path 420 exceeds the target coolant temperature, the control unit 720 controls the differential pressure installed on the first flow path 410. A second control signal that downwardly adjusts the opening amount of the differential pressure control valve of the regulator 210 may be transmitted to the differential pressure regulator 210 . Accordingly, the differential pressure regulator 210 may adjust the opening amount of the differential pressure control valve downward by a predetermined amount based on the second control signal from the control unit 720. Here, when the opening amount of the differential pressure control valve is adjusted downward by a predetermined amount, the flow rate of coolant flowing in along the first flow path 410 decreases, and as a result, the flow rate of coolant flowing in along the second flow path 420 increases and the flow rate of coolant flowing in along the second flow path 420 increases. 2 It is possible to lower the inlet coolant temperature of the electrical components on the flow path 420 to below the target coolant temperature.

Of course, as in the embodiment of FIG. 6, when the second cooling line 120 is branched into three or more flow paths, the control unit 720 generates a control signal appropriate for each flow path situation to control each differential pressure regulator 210. ) can also be sent.

The thermal management operation flow of the fuel cell system according to the present invention configured as described above will be described in more detail as follows.

FIG. 8 is a diagram illustrating the operation flow of a thermal management control method of a fuel cell system according to an embodiment of the present invention.

Referring to FIG. 8, when the thermal management system is turned on (S110), the fuel cell system operates the differential pressure control valve at 100 to cool the electrical components 200 on the second cooling line 120 during initial operation. % opens (S120).

Thereafter, the fuel cell system distributes the flow rate through a differential pressure control valve according to a preset reference pressure in order to equally distribute the coolant flowing into the first flow path 410 and the second flow path 420 by the second pump 205. Adjust (S130). As an example, the fuel cell system adjusts the reference pressure of the first flow path 410 to A [bar] and the standard pressure of the second flow path 420 to B [bar]. It is possible to control the differential pressure control valve of the differential pressure regulator 210 installed on the top.

The fuel cell system checks the inlet coolant temperature of each electrical component on the first flow path 410 and the second flow path 420 while the coolant flows in along the first flow path 410 and the second flow path 420 (S140) ). In the 'S140' process, the fuel cell system can check the inlet coolant temperature of each electrical component 200 based on the temperature information received from the temperature sensors 711 to 719 installed at the inlet of the electrical component 200 of each flow path. there is.

The fuel cell system can determine whether the inlet coolant temperature of each electrical component 200 confirmed in the 'S140' process exceeds the target coolant temperature.

First, when the fuel cell system determines that the inlet coolant temperature of at least one electrical component 200 within the first flow path 410 exceeds the target coolant temperature (S150), the coolant flow rate on the first flow path 410 increases. The opening amount of the differential pressure control valve on the first flow path 410 is increased (S160). Meanwhile, when the fuel cell system determines that the inlet coolant temperature of at least one electrical component 200 within the second flow path 420 exceeds the target coolant temperature (S170), the coolant flow rate on the second flow path 420 increases. The opening amount of the differential pressure control valve on the first flow path 410 is reduced (S180).

Here, the first flow path 410 and the second flow path 420 are branches of the second cooling line 120 as in the embodiment of FIG. 4, and the first flow path 410 and the second flow path 420 have Each electrical component 200 may be arranged in parallel.

As such, when the fuel cell system according to the present invention cools the electrical components 200 using coolant moving through the second cooling line 120, the electrical components 200 are arranged in parallel by branching the flow path. The cooling efficiency of the electrical components 200 can be increased by minimizing the pressure reduction of the coolant flow rate and equally distributing the flow rate to each flow path using the differential pressure regulator 210, or by overdistributing the coolant flow rate to the flow path requiring additional cooling. You can.

The above description is merely an illustrative explanation of the technical idea of the present invention, and various modifications and variations will be possible to those skilled in the art without departing from the essential characteristics of the present invention.

Accordingly, the embodiments disclosed in the present invention are not intended to limit the technical idea of the present invention, but are for illustrative purposes, and the scope of the technical idea of the present invention is not limited by these embodiments. The scope of protection of the present invention should be interpreted in accordance with the claims below, and all technical ideas within the equivalent scope should be construed as being included in the scope of rights of the present invention.

10: Fuel cell stack 60: First radiator
70: second radiator 120: second cooling line
205: second pump 200, 220~270: electrical components
210, 215: differential pressure regulator 410: first flow path
420: 2nd Euro 430: 3rd Euro
711~719: Temperature sensor 720: Control unit

Claims (16)

A plurality of electrical components;
a radiator disposed on a cooling line through which coolant circulates through the plurality of electrical components and configured to cool the coolant; and
It includes a pump disposed on the cooling line to flow the coolant to the electrical components,
The plurality of electrical components are,
A fuel cell system arranged in parallel in one section of the cooling line between the outlet of the pump and the inlet of the radiator. In claim 1,
The cooling line is,
Branched into a first flow path and a second flow path at a first point on the cooling line connected to the outlet of the pump, and combining the first flow path and the second flow path at a second point on the cooling line connected to the inlet of the radiator. Characterized by a fuel cell system. In claim 2,
The first flow path and the second flow path are,
A fuel cell system characterized by at least one electrical component arranged in series. In claim 2,
The fuel cell system further includes a differential pressure regulator disposed in one of the first flow path and the second flow path to adjust the flow rate of coolant flowing along the corresponding flow path. In claim 4,
The differential pressure regulator,
A fuel cell system, characterized in that the flow rate of coolant flowing into the corresponding passage is controlled by adjusting the differential pressure control valve according to the reference pressure set in response to the passage in which the differential pressure regulator is disposed. In claim 5,
A fuel cell system further comprising a control unit that controls the differential pressure regulator according to the inlet coolant temperature of each electrical component disposed on the first flow path and the second flow path. In claim 6,
The control unit,
When the inlet coolant temperature of at least one of the electrical components disposed on the first flow path exceeds the target coolant temperature, a first control signal for upwardly adjusting the opening amount of the differential pressure control valve to increase the coolant flow rate of the first flow path A fuel cell system characterized in that it transmits to the differential pressure regulator. In claim 6,
The control unit,
When the inlet coolant temperature of at least one of the electrical components disposed on the second flow path exceeds the target coolant temperature, a second control signal for downwardly adjusting the opening amount of the differential pressure control valve so that the coolant flow rate of the first flow path decreases. A fuel cell system characterized in that it transmits to the differential pressure regulator. In claim 6,
The fuel cell system further includes a temperature sensor disposed at the inlet of the electrical component on the first flow path and the second flow path, respectively, to measure the temperature of the coolant at the inlet of the corresponding electric component. In claim 4,
The differential pressure regulator,
A fuel cell system disposed on a flow path between the first point and the electrical component, and disposed in a position close to the first point. In claim 2,
The cooling line is,
A fuel cell system characterized in that it branches into at least three flow paths between the first point and the second point. Flowing coolant to each electrical component disposed on a first flow path and a second flow path branched from a section of a cooling line in which coolant passing through a plurality of electric parts is circulated; and
adjusting the flow rate of coolant flowing into the first flow path and the second flow path according to the inlet coolant temperature of each electrical component;
A thermal management control method for a fuel cell system including. In claim 12,
A thermal management control method for a fuel cell system, further comprising checking the inlet coolant temperature of each electrical component disposed on the first flow path and the second flow path. In claim 12,
The step of adjusting the coolant flow rate is,
A thermal management control method for a fuel cell system, comprising the step of controlling a differential pressure regulator disposed on the first flow path according to the inlet coolant temperature of each electrical component. In claim 14,
The step of controlling the differential pressure regulator is,
When the inlet coolant temperature of at least one of the electrical components disposed on the first flow path exceeds the target coolant temperature, adjusting the opening amount of the differential pressure control valve upward to increase the coolant flow rate of the first flow path. A thermal management control method for a fuel cell system characterized by: In claim 14,
The step of controlling the differential pressure regulator is,
When the inlet coolant temperature of at least one of the electrical components disposed on the second flow path exceeds the target coolant temperature, downwardly adjusting the opening amount of the differential pressure control valve so that the coolant flow rate of the first flow path decreases. A thermal management control method for a fuel cell system characterized by:

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