KR20180088971A - Hydrogen supply system for fuelcell in automobile - Google Patents

Abstract

The present invention relates to a hydrogen supply device for automotive fuel cells. More specifically, the present invention relates to a hydrogen supply device for automotive fuel cells. To this end, in the hydrogen supply device for fuel cells, hydrogen charged in a fuel tank at high pressure is regulated under constant pressure by means of a high-pressure regulator while being regulated under pressure to be supplied to a stack by a low-pressure regulator, and a unit for controlling the flow of hydrogen is provided between the high-pressure regulator and the low-pressure regulator.

Description

Technical Field [0001] The present invention relates to a hydrogen supply system for a fuel cell,

The present invention relates to a hydrogen fuel cell, which is a core of an environmentally friendly energy source. More particularly, the present invention relates to an apparatus for a hydrogen supply system used in an automobile. The hydrogen tank is controlled by a high- To a pressure that can be supplied to the stack through a regulator, and means for regulating the flow of hydrogen between the high-pressure regulator and the low-pressure regulator.

A fuel cell used in automobiles is a kind of battery that converts the chemical energy generated by the oxidation of fuel directly into electric energy. In particular, unlike a secondary cell, a fuel cell continuously supplies reactants from the outside and simultaneously discharges the reaction products to the outside of the system. Therefore, if the fuel is continuously supplied, the electricity can be continuously produced.

The most widely known of these fuel cells is the hydrogen-oxygen fuel cell. In the hydrogen-oxygen fuel cell, hydrogen, which is fuel, is supplied to the anode to cause electrical oxidation, and oxygen, which is an oxidant, is supplied to the anode to cause electrical reduction. At this time, as electrons move by oxidation and reduction, electric energy is generated.

However, since the electric energy generated in the unit cell is insignificant, the fuel cell is provided in the form of a stack of tens to hundreds of unit cells stacked.

Therefore, fuel cells can be developed even with large capacity fuel cells of several hundred MW by increasing the number of stacked stacks. Such fuel cells are used for various purposes, and are mainly used for power generation, heating, and transportation for commercial operation.

More particularly, the present invention relates to a fuel cell hydrogen supply apparatus for a vehicle, which improves the efficiency of the fuel cell by regulating the temperature of the hydrogen gas flowing from the hydrogen tank.

1, hydrogen supplied from a fuel tank 112 to a high-pressure fuel is regulated to a predetermined pressure through a high-pressure regulator 114 and is supplied to a stack 110 through a low-pressure regulator 116, As shown in FIG. A solenoid valve 118 is provided between the high-pressure regulator 114 and the low-pressure regulator 116 to regulate the flow of hydrogen. In addition, since the hydrogen supplied to the stack 110 supplies more than the amount required for the reaction in order to increase the efficiency, the exhaust gas contains not only water vapor but also a considerable amount of hydrogen. Therefore, A hydrogen recycle line 122 branched from the hydrogen recycle line 122 is formed. Also, the hydrogen recirculation line 122 is provided with a blower 124 so that the recirculated hydrogen gas is easily circulated to the stack 110. Further, it is needless to say that the blower 124 requires power for rotation, but an ejector that does not require power may be provided as needed. When the ejector is installed, the gas supplied from the fuel tank 112 and the gas recirculated in the ejector are mixed and supplied to the stack 110.

On the other hand, when the relative humidity of the hydrogen supplied to the stack is high, a droplet is generated to cause a flooding phenomenon to shut off the flow path. When the relative humidity is low, the humidity of the electrode decreases and the electrolyte membrane dries, A dryout phenomenon that is rapidly reduced occurs.

Therefore, the relative humidity of the hydrogen gas supplied to the stack should be maintained at 80% or more in consideration of efficiency, but should be controlled at less than 100%.

However, since the temperature of the hydrogen gas discharged from the stack is relatively constant at about 70 ° C., the temperature of the hydrogen supplied from the fuel tank varies depending on the temperature of the atmosphere. Therefore, Uneasy.

Therefore, when the temperature falls to -30 ° C, the hydrogen gas discharged from the hot and humid stack and the hydrogen supplied from the fuel tank are mixed with each other. In addition, the temperature of the mixed gas is excessively lowered and the relative humidity reaches 100% In order to prevent this, a heat exchanger is installed to preheat the temperature of the hydrogen gas supplied from the fuel tank to the waste heat of the cooling water discharged from the stack.

However, since the temperature of the hydrogen gas supplied from the fuel tank is already higher than 30 ° C. in the hot period, the temperature of the hydrogen gas supplied to the ejector is increased to 45 ° C. or more when the cooling water is discharged from the stack. The temperature of the mixed gas is excessively increased and the relative humidity is reduced to 50% or less, thereby causing a dry-out phenomenon.

The amount of the cooling water for preheating the hydrogen gas supplied from the fuel tank can be adjusted according to the temperature of the hydrogen gas supplied from the fuel tank so that the relative humidity of the hydrogen gas supplied to the stack can be easily controlled, Fuel cell hydrogen supply device,

As described above, the present invention provides a fuel cell hydrogen supply device capable of improving the efficiency of a fuel cell by optimizing the relative humidity of the hydrogen electrode,

The present invention provides a fuel cell hydrogen supply apparatus that does not require a separate driving unit for controlling the amount of cooling water by regulating the amount of cooling water by a pressure reducing valve that operates according to the pressure of the working fluid accommodated in the sensing cylinder.

And a sensing unit for surrounding the outer periphery of the hydrogen supply line, thereby providing a fuel cell hydrogen supply device capable of sensitively sensing a temperature change of the hydrogen supply line.

A vehicular fuel cell hydrogen supply apparatus includes: a fuel tank in which hydrogen is stored; A regulator for regulating the pressure of hydrogen supplied from the fuel tank; An ejector for supplying pressure-regulated hydrogen to the stack in the regulator; A heat exchanger installed between the fuel tank and the ejector for exchanging heat between hydrogen supplied through a hydrogen supply line for supplying hydrogen and cooling water discharged from the stack; A recirculation line for recirculating the gas discharged from the stack to supply the gas to the ejector; And an adjusting unit adjusting the amount of cooling water supplied to the heat exchanger,

The control unit includes a sensing tube installed on the hydrogen supply line and accommodating a working fluid; And a pressure reducing valve operating according to the pressure of the working fluid accommodated in the sensing tube,

Wherein the sensing cylinder is provided to surround the outer periphery of the hydrogen supply line,

Wherein the pressure reducing valve comprises: a partition wall in which a valve seat having a port formed at an inner center of a cooling water supply line for supplying cooling water to the heat exchanger is axially extended; A housing formed on a circumference of a cooling water input line corresponding to the partition; A diaphragm that divides the inside of the housing into upper and lower portions and communicates the divided upper portion and the sensing tube; An opening / closing member installed on a bottom surface of the diaphragm to open and close the port by operation of the diaphragm; And a spring installed to elastically support the opening and closing member.

It is possible to adjust the amount of the cooling water for preheating the hydrogen gas supplied from the fuel tank according to the temperature of the hydrogen gas supplied from the fuel tank so as to easily adjust the relative humidity of the hydrogen gas supplied to the stack, Humidity can be optimized,

The efficiency of the fuel cell can be improved by optimizing the relative humidity of the hydrogen electrode as described above,

The amount of the cooling water is controlled by the pressure reducing valve operating according to the pressure of the working fluid accommodated in the sensing cylinder, so that a separate driving unit for controlling the amount of the cooling water is not required,

And a sensing chamber surrounding the outer periphery of the hydrogen supply line, so that the heat transfer area is wide, so that a temperature change of the hydrogen supply line can be sensitively sensed.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a view showing a hydrogen supply device of Patent No. 836371 (June 20, 2008).
FIG. 2 is a view showing a hydrogen supply device of Patent No. 1281011 (Jun. 26, 2016).
3 is a view showing an adjusting unit of the hydrogen supply apparatus.
4 is a detailed sectional view showing a main part of the hydrogen supply device.
5 is a state view showing the decompression valve of the hydrogen supply device is opened.
Hereinafter, an embodiment of the fuel cell hydrogen supply apparatus for a vehicle according to the present invention will be described,
In Fig. 6, Fig. 6A is a cross-sectional view of any part; FIG. 6B is an auxiliary diagram for explaining the configuration of any part; FIG.
FIG. 7 shows an operation. FIG. 7A is a state diagram showing a state; FIG. 7B is a state diagram showing another state.
FIG. 8 is an exemplary diagram for checking and showing a change according to an operation state.
9 is a cross-sectional side view of another embodiment of the present invention.

The configuration of the fuel cell hydrogen supply system for a vehicle according to the present invention will be described first with reference to FIGS. 2 to 5.

A regulator 20 for regulating the pressure of hydrogen supplied from the fuel tank 10; a regulator 20 for regulating the pressure of the hydrogen supplied from the fuel tank 10; An ejector 30 for supplying hydrogen to the ejector 30 from the fuel tank 10 and a hydrogen supply line 12 for supplying hydrogen to the ejector 30 from the fuel tank 10, A regeneration line 50 for recycling the gas discharged from the stack S to the ejector 30 and a regulator for regulating the amount of cooling water supplied to the heat exchanger 40, (60).

The fuel tank 10 is a tank for storing hydrogen and is provided so as to withstand a pressure of several hundred bar or more and is durable so as not to be destroyed by external impact.

The regulator 20 is a device for regulating the pressure of hydrogen supplied from the fuel tank 10, and may be configured as two stages as necessary.

The ejector 30 is a device for supplying pressure-regulated hydrogen to the stack S in the regulator 20 and is connected to a recirculation line 50 at a side of the ejector 30 to introduce hydrogen.

The heat exchanger 40 is installed in the hydrogen supply line 12 between the fuel tank 10 and the ejector 30 and the cooling water discharged from the stack S and the hydrogen passing through the hydrogen supply line 12 are connected to each other Heat exchanged. Since the cooling water discharged from the stack S is higher in temperature than the hydrogen passing through the hydrogen supply line 12, the hydrogen passing through the hydrogen supply line 12 is preheated by the waste heat of the cooling water, .

The recycle line 50 is a line that circulates the exhaust gas discharged from the stack S to the ejector 30 and contains a larger amount of hydrogen than the amount of hydrogen gas input to the stack S can react The exhaust gas discharged from the stack S contains a considerable amount of surplus hydrogen gas.

The regulator 60 regulates the amount of the cooling water supplied to the heat exchanger 40 and regulates the amount of the cooling water so that the temperature of the hydrogen gas supplied to the ejector 30 can be controlled.

As shown in FIG. 3, the controller 60 includes a sensing tube 62 installed on the hydrogen supply line 12 and receiving a working fluid, And a communication pipe (63) communicating between the pressure reducing valve and the pressure reducing valve. Here, it is preferable that the sensing tube 62 surrounds the outer periphery of the hydrogen supply line 12 to increase the heat transfer area.

4, a valve seat 66b formed with a port 66a at the center of the inside of a cooling water supply line 42 for supplying cooling water to the heat exchanger 40 is disposed in the axial direction A housing 67 formed on the circumference of the cooling water input line 46 corresponding to the partition 66 and a partition wall 66 extending upwardly from the upper portion of the housing 67, An opening and closing member 69 provided on the lower surface of the diaphragm 68 for opening and closing the port 66a by the operation of the diaphragm 68 and an opening and closing member 69 And a spring 70 installed to elastically support the spring 70.

The partition 66 is provided so as to cross the inside of the cooling water supply line 42 and has a valve seat 66b formed with a port 66a at its center to extend in the axial direction. The amount of the cooling water supplied to the heat exchanger 40 is determined depending on whether the port 66a formed in the valve seat 66b is opened or closed.

The housing 67 is installed on the circumference of the cooling water input line 46 corresponding to the partition 66 and has an opening 67a communicating with the sensing chamber 62 above the partition 67. Preferably, the housing 67 has a flat cross section so that the diaphragm 68 can be installed.

The diaphragm 68 is installed inside the housing 67 to divide the inside of the housing 67 up and down. The divided upper portion 67b of the housing 67 is formed to communicate with the pressure sensing cylinder 62 and the divided bottom surface of the housing 67 is provided with an opening and closing valve 66a for opening and closing the port 66a of the valve seat 66b, Member 69 is provided. Therefore, when the temperature of the working fluid accommodated in the sensing tube 62 rises and evaporates, the diaphragm 68 pushes the working fluid inside the sensing tube 62 while expanding. When the temperature of the working fluid accommodated in the sensing tube 62 is lowered and condensed, the working fluid in the sensing tube 62 contracts and a negative pressure is formed to restore the diaphragm 68 to the state before the expansion .

The opening and closing member 69 is provided to open and close the port 66a by the operation of the diaphragm 68 and includes a stem 69a fixed to the diaphragm 68, And an abutting member 69b which comes into close contact with the abutting member 66a.

The spring 70 is provided to elastically support the opening and closing member 69 and the spring 70 urges the contact member 69b to seal the port 66a of the valve seat 66b. Accordingly, when the working fluid accommodated in the sensing tube 62 is condensed and a negative pressure is formed to overcome the tension of the spring 70, the diaphragm 68 is operated and the cooling water input line 46 is opened.

Hereinafter, a method of controlling the temperature of the hydrogen gas supplied to the ejector according to the fuel cell hydrogen supply apparatus for a vehicle will be described.

In the summer, since the atmospheric temperature is high, the temperature of the hydrogen supplied to the fuel tank 10 also rises. Accordingly, the working fluid contained in the pressure sensing cylinder 62 evaporates to increase the pressure, and the working fluid having the increased pressure moves to the upper portion of the housing 67 communicating with the pressure sensing cylinder 62, And pressurized. At this time, the opening / closing member 69 closes the port 66a formed in the valve seat 66b while maintaining the lowered state by not only the tension of the spring 70 but also the urging force of the diaphragm 68. [ Therefore, the hydrogen supplied from the fuel tank 10 flows into the ejector 30 as it is discharged from the fuel tank 10 because the cooling water can not flow into the heat exchanger 40.

Next, when the temperature falls, the temperature of the hydrogen supplied to the fuel tank also falls. When the temperature of the hydrogen supplied from the fuel tank 10 is lowered, the working fluid stored in the pressure sensing cylinder 62 is condensed and the pressure is lowered, thereby forming a negative pressure inside the pressure sensing cylinder 62. When a negative pressure is formed inside the pressure sensing cylinder 62, the diaphragm 68 is bent upward to overcome the tension of the spring 70 as shown in FIG. Accordingly, the opening / closing member 69 fixed to the center of the diaphragm 68 rises to open the port 66a formed in the valve seat. As described above, when the port 66a formed in the valve seat 66b is opened, the cooling water flows into the heat exchanger 40 and heat-exchanges with the hydrogen, so that the temperature of the hydrogen supplied to the ejector 30 rises.

As described above, since the pressure reducing valve 64 operates to regulate the amount of the cooling water with respect to the rising and falling of the air temperature, the relative humidity of the hydrogen entering the stack S can be controlled without a separate driving source.

Therefore, the fuel cell hydrogen supply apparatus for a vehicle supplies hydrogen of an appropriate humidity to prevent a phenomenon such as flooding or dry-out, thereby further improving the efficiency of the fuel cell.

Next, based on the above description, the configuration related to the more advanced pressure reducing valve 64 used in the automotive hydrogen supply system of the present invention will be described in detail with reference to Fig. 6 below.

The pressure reducing valve (64) of the present invention minimizes the volume and simplifies the configuration, thereby avoiding complication, thereby increasing the durability. In order to avoid jamming on the communication pipe (63) a housing 67 used externally to serve as an actuator and a complicated diaphragm 68 inside the housing 67 and the additional configuration used to operate it are not used. Instead, a balloon 80 (baloon), such as an airbag or a balloon, whose volume can be changed as shown in Fig. 7, is used as an actuator.

In Fig. 6, the communication pipe 63 is held in contact with the cooling water input line 46 directly. To this end, a communication pipe fitting bracket 46a having a perforation (formed with a hole) for fixing the body circumference of the communication pipe 63 is formed vertically above the cooling water input line 46 in the longitudinal direction, And the outer circumferential body of the communication pipe 63 is tightly sealed by welding or bonding, so as to be prevented from being completely leaked.

The end portion of the communication pipe 63 as shown in Fig. 6B is arranged in line with the flow direction (along the flow direction) along the length of the cooling water input line 46 so as to minimize the flow interruption of the cooling water a3 (b1) so as to bend (b3) so as to change the direction from vertical (b2) to horizontal (b1). Thereafter, the open end of the balloon 80, that is, the balloon inlet 80a) is completely and tightly adhered to the communication pipe end 63a of the bending b3 as shown in FIG. 6A. The balun 80 coupled to the end of the communication pipe 63 naturally aligns in the longitudinal direction of the cooling water input line 46 so as to minimize the resistance in accordance with the flow direction of the cooling water a3 b1).

If the working fluid a1 contained in the pressure sensing cylinder 62 increases in pressure, the working fluid will fill the direct baloon 80 and thus the volume of the baloon 80 will increase The operation of the pressure sensing cylinder 62 may not be properly reflected due to a change in the volume again due to the cooling water a3 in the cooling water input line 46. [ Therefore, it is necessary to thoroughly block the heat so that the change in volume is minimized. To this end, the member of the balun 80 may be provided as a high-performance insulating member, or the thickness of the balun 80 skin may be very thick, It is desirable to minimize it.

However, since the balun 80 continues to be in contact with the cooling water a3 even when the insulating material or the thick material is used, the balun 80 is influenced by the temperature of the cooling water a3, Lt; RTI ID = 0.0 > (a3) < / RTI > In this case, a fluid having a minimal volume change (volume change) due to thermal change can be adopted only as a fluid filling the balun 80. This fluid is called a balun filling fluid a2, The fluid a2 preferably has a different specific gravity (density, weight) from the working fluid a1. An example of the drawing is illustrated such that the balun filling fluid a2 is selected as a fluid having a large specific gravity and is not mixed with the working fluid a1. As shown in FIG. 6A, an interface a12 due to the specific gravity difference is generated between the working fluid a1 and the balun filling fluid a2 in the communication pipe 63. As shown in FIG.

Next, a working method will be described with reference to FIGS. 7 and 8. FIG.

First, when the pressure (volume) of the working fluid a1 received in the pressure sensing cylinder 62 increases, the working fluid a1 pushes the balloon filling fluid a2. Therefore, in FIG. 8, And moves down from the highest point d1 to the lowest point d2 (c2). Accordingly, when the balun filling fluid a2 flows into the balun 80 by the change in the volume of the difference in the volume of the communication pipe 63, that is, the volume change d12 in the tube, the volume of the balun 80 The cooling water is expanded like a ball so that a section of the cooling water input line 46 is closed to block the flow of the cooling water a3.

Conversely, when the pressure of the working fluid a1 decreases, the working fluid a1 attracts the balun filling fluid a2, so that the interface a12 moves upward from the low point to the highest point c1, The volume of the balun 80 is reduced to the original value because the balun filling fluid a2 escapes from the balun 80 by the amount of change d12 and the flow of the cooling water a3 is allowed again. In this case, if the balun 80 is made of an elastic material such as rubber having an elastic restoring force against a change in volume, the pressure of the working fluid a1 can be operated while maintaining appropriate tension owing to the elastic recovery force. 2 to 5 and the spring 70 of the opening and closing member 69 illustrated in Fig.

As a result, the volume change of the balun 80, that is, the balun volume change e12, coincides with the in-pipe volume change d12, and only the balun filling fluid a2 replaces the working fluid a1 Is filled in the balun 80 disposed inside the cooling water input line 46 so that the working fluid a1 is not affected by the temperature of the cooling water a3 at all but only by the influence of the sensing tube 62 .

9, the communication pipe 63 or all of the sections where the interface moves may be provided with a confirmation window 63c provided by a transparent member such as glass or transparent plastic, (Movement) of the user (user) can be confirmed. Through this, the manager (inspector, driver) can check and confirm whether or not the operation of the pressure reducing valve 64 is normal, and take appropriate measures.

At this time, the pigment may be added so that the color of the working fluid a1 and the color of the balun filling fluid a2 are different from each other so that the boundary surface a12 can be easily identified. Alternatively, a float 63d (float) having a median specific gravity of the working fluid a1 and the balun filling fluid a2 may be interposed between and interposed between the boundary surface a12 to facilitate identification and confirmation can do. The float 63d functions to prevent the working fluid a1 and the balun filling fluid a2 from coming into contact with each other so as to completely separate the two fluids from each other so that they do not mix with each other at the interface a12 It can also serve as a role.

Decompression (passage 62); A pressure reducing valve 64; A ball (rune 80);
Confirmation window 63c; A float 63d;

Claims (2)

A hydrogen supply device for a fuel cell,
The hydrogen charged at high pressure in the fuel tank is regulated to a certain pressure through the high pressure regulator and to a pressure that can be supplied to the stack through the low pressure regulator, and means for regulating the flow of hydrogen between the high pressure regulator and the low pressure regulator is included Wherein the fuel cell is a fuel cell. The method according to claim 1,
Wherein a pressure reducing valve or a solenoid valve is provided as a means for regulating the flow of the hydrogen.

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