KR102377053B1 - Automobile hydrogen supplysystem - Google Patents

Abstract

The present invention relates to a fuel cell hydrogen supply system, and more specifically, by opening a solenoid valve for starting and stopping, adjusting the hydrogen stored in the vehicle's fuel tank to a constant pressure by a high-pressure regulator and a low-pressure regulator, and supplying it to the inlet of the fuel cell stack, In order to reuse residual hydrogen generated at the outlet of the stack, it is related to a fuel cell hydrogen material circulation supply device equipped with a hydrogen material circulation line and a recirculation blower.
A regulator controls the pressure of hydrogen in the fuel tank, an ejector supplies the pressure-controlled hydrogen to the stack, and the hydrogen supplied to a hydrogen supply line installed between the fuel tank and the ejector to supply hydrogen and discharged from the stack A heat exchanger exchanges heat with the cooling water, and excess hydrogen of exhaust gas discharged from the stack through a recirculation line is circulated to the ejector.
A control unit is installed so as to surround the outer periphery of the hydrogen supply line, and includes a temperature sensing tube for accommodating a working fluid, and a pressure reducing valve operating as an actuator according to the pressure of the working fluid accommodated in the temperature sensing vessel, and is supplied to the heat exchanger. Adjust the amount of cooling water.
The communication pipe communicates between the temperature sensing tube and the pressure reducing valve, and is fixed in contact with the cooling water input line, and the communication pipe is perforated so as to be fixed by inserting the circumference of the body of the communication pipe above the cooling water input line in the longitudinal direction. The bracket 46a is vertically configured b2, and the outer peripheral body of the communication pipe is coupled thereto.
The end of the communication pipe is bent at a right angle (b3) so as to be aligned (b1) side by side along the length of the cooling water input line, the direction is changed from vertical (b2) to horizontal (b1), and the bending (b3) becomes An open balun inlet 80a of a balun is closely attached to the provided communication pipe end 63a.

Description

Fuel cell hydrogen supply system {Automobile hydrogen supply system}

The present invention relates to a fuel cell hydrogen supply system, and more particularly, by opening a solenoid valve for starting and stopping, adjusting the hydrogen stored in the fuel tank to a constant pressure by a high-pressure regulator and a low-pressure regulator, and supplying it to the inlet of the fuel cell stack; In order to reuse the residual hydrogen generated at the exit, it is related to the fuel cell hydrogen material circulation supply device of transportation means such as a vehicle equipped with a hydrogen material circulation line and a recirculation blower.

In relation to the fuel cell hydrogen supply system of the present invention, the fuel cell can continuously produce electricity while the reactants are continuously supplied from the outside and the reaction products are continuously discharged to the outside of the system at the same time. An automobile fuel cell is a means of directly converting chemical energy generated by the oxidation of fuel into electrical energy. In a hydrogen-oxygen fuel cell, hydrogen, a fuel, is supplied to the anode to cause electrical oxidation, and oxygen, an oxidizing agent, is supplied to the anode. causes electrical reduction. As electrons move through oxidation and reduction, electrical energy is generated. Since the electrical energy generated from the unit cell is insignificant, the fuel cell is provided in the form of a stack in which tens to hundreds of unit cells are stacked. As for the fuel cell capacity, if the number of stacks is increased, a fuel cell with a large capacity of several hundred MW is possible. Fuel cells are widely used for power generation, heating, and transportation.

In general, in a hydrogen supply system (device) of a fuel cell, hydrogen charged at high pressure in a fuel tank 112 is adjusted to a constant pressure through a high pressure regulator 114 , and is supplied to the stack 110 through a low pressure regulator 116 . It is regulated to a pressure that can be Here, a solenoid valve 118 is installed between the high pressure regulator 114 and the low pressure regulator 116 to control the flow of hydrogen. In addition, since the hydrogen supplied to the stack 110 is supplied in an amount greater than the amount required for the reaction in order to increase efficiency, the exhaust gas contains not only water vapor but also a significant amount of hydrogen, so to recycle it, the exhaust line 120 A branched hydrogen recirculation line 122 is formed. In addition, a blower 124 is installed in the hydrogen recirculation line 122 so that the recirculated hydrogen gas is easily circulated to the stack 110 . In addition, although the blower 124 requires power to rotate, an ejector that does not require power may be installed as needed. Here, when the ejector is installed, the gas supplied from the fuel tank 112 and the recirculated gas are mixed inside the ejector and supplied to the stack 110 .

When the relative humidity is high, the hydrogen supplied to the stack causes a flooding phenomenon that closes the flow path due to the formation of droplets. A slow dryout phenomenon occurs. Normally, the temperature of hydrogen gas discharged from the stack is relatively constant at about 70°C, but since the temperature of hydrogen supplied from the fuel tank varies depending on the temperature of the atmosphere, it is easy to supply hydrogen gas with an appropriate relative humidity to the stack. not. In the cold season when the temperature drops to -30℃, when the hydrogen gas discharged from the high-temperature and high-humidity stack and the hydrogen supplied from the fuel tank are directly mixed, the temperature of the mixed gas excessively drops and the relative humidity reaches 100%, resulting in a large amount of liquid. In order to prevent this, a heat exchanger for preheating the temperature of hydrogen gas supplied from the fuel tank with waste heat of the coolant discharged from the stack is provided.

However, in high temperature weather, since the temperature of the hydrogen gas supplied from the fuel tank is already above 30°C, when preheating with coolant discharged from the stack, the temperature of the hydrogen gas supplied to the ejector rises to 45°C or higher, so hydrogen discharged from the stack When mixed with gas, the temperature of the mixed gas becomes excessively high, and the relative humidity drops to half or less, causing a dry-out phenomenon. In relation to this, reference is made to Registered Patent No. 836371 (June 20, 2008) illustrated in FIG. 1 .

The present invention provides a fuel cell hydrogen supply system capable of improving the efficiency of a fuel cell by optimizing the relative humidity of the hydrogen electrode, and adjusting the amount of coolant for preheating the hydrogen gas supplied from the fuel tank to the hydrogen gas supplied from the fuel tank To provide a fuel cell hydrogen supply system capable of optimizing the relative humidity of a hydrogen electrode by adjusting according to the temperature of An object of the present invention is to provide a fuel cell hydrogen supply system that does not require a separate driving unit to control the amount of coolant as the amount of coolant is adjusted with a pressure reducing valve that operates according to the pressure of

In the fuel cell hydrogen supply system of the present invention, after the hydrogen charged in the fuel tank is adjusted to a constant pressure through the high pressure regulator, the pressure is adjusted to a pressure that can be supplied to the stack through the low pressure regulator, and the solenoid valve is connected to the high pressure regulator and the low pressure It is installed between the regulators to control the flow of hydrogen, an ejector supplies the pressure-controlled hydrogen to the stack, and a heat exchanger is disposed between the fuel tank and the ejector so that hydrogen supplied through a hydrogen supply line and in the stack heat exchange with the discharged cooling water,

A control unit adjusts the amount of cooling water supplied to the heat exchanger, but is installed to surround the outer periphery on the hydrogen supply line, a thermosensing passage for accommodating the working fluid (a1), and an actuator according to the pressure of the working fluid (a1) comprising an operating pressure reducing valve;

A communication pipe communicating between the temperature sensing tube and the pressure reducing valve is provided, and the communication pipe is fixed in direct contact with the cooling water input line, and the body of the communication pipe is inserted and fixed above the cooling water input line in the longitudinal direction. The communication pipe fitting bracket (46a) is vertically configured,

The communication pipe end (63a) side of the communication pipe is bent and aligned (b1) side by side in the longitudinal direction of the cooling water input line, and a balun is coupled to the communication pipe end (63a) in the longitudinal direction of the cooling water input line. Aligned side by side (b1), in conformity with the flow of the coolant (a3) to reduce the resistance,

When the pressure and volume of the working fluid (a1) accommodated in the thermostat increases, the working fluid (a1) directly fills the balloon so that the volume of the balloon expands;

A balloon filling fluid (a2) having a larger specific gravity than the working fluid (a1) is provided, and the interface (a12) due to the specific gravity difference between the working fluid (a1) and the balloon filling fluid (a2) in the communication pipe is generated so that they do not mix with each other, so that only the balloon filling fluid (a2) is diverted to fill the balloon,

The section of the interface a12 in the communication pipe is adopted as a transparent member, so that the movement of the interface a12 can be confirmed from the outside.

According to the present invention, there is provided a fuel cell hydrogen supply system capable of improving the efficiency of a fuel cell by optimizing the relative humidity of the hydrogen electrode. By adjusting the amount of coolant for preheating the hydrogen gas supplied from the fuel tank according to the temperature of the hydrogen gas supplied from the fuel tank, the relative humidity of the hydrogen gas supplied to the stack can be easily adjusted, so that the relative humidity of the hydrogen electrode To provide a fuel cell hydrogen supply system that can optimize Provided is a fuel cell hydrogen supply system that does not require a separate driving unit to control the amount of coolant by adjusting the amount of coolant with a pressure reducing valve that operates according to the pressure of a working fluid accommodated in a thermos.

1 is an exemplary view of the configuration of a fuel cell hydrogen supply system for a vehicle according to the related art.
2 is another exemplary diagram.
3 is a view showing a control unit of a fuel cell hydrogen supply system.
4 is a detailed cross-sectional view showing an essential part of a fuel cell hydrogen supply system.
5 is a state diagram showing that the pressure reducing valve of the fuel cell hydrogen supply system is opened.
6 below relates to the present invention. 6A is a cross-sectional view of a certain part, and FIG. 6B is an exemplary view for explaining the configuration.
7 is a state diagram illustrating an operation. Fig. 7A is one state, and Fig. 7B is another state.
8 is an exemplary diagram illustrating a check change according to an operation state.

A fuel cell hydrogen supply system device for a vehicle is reviewed through Patent Registration No. 1281011 (June 26, 2013), a fuel tank 10 in which hydrogen is stored, and a regulator for regulating the pressure of hydrogen supplied from the fuel tank 10 (20), an ejector (30) for supplying hydrogen whose pressure is controlled by the regulator (20) to the stack (S), and a hydrogen supply line (12) for supplying hydrogen from the fuel tank (10) to the ejector (30) A heat exchanger 40 for exchanging heat between the hydrogen supplied and the cooling water discharged from the stack S, a recirculation line 50 for recirculating the gas discharged from the stack S and supplying the ejector 30, and and a control unit 60 for controlling the amount of cooling water supplied to the heat exchanger 40 .

The fuel tank 10 is a tank for storing hydrogen, and is provided to withstand a pressure of several hundred bar or more, and at the same time to have durability not to be destroyed by an external collision. The regulator 20 is a device for regulating the pressure of hydrogen supplied from the fuel tank 10 and may be configured in two stages if necessary. The ejector 30 is a device for supplying hydrogen whose pressure is controlled by the regulator 20 to the stack S, and is connected to the recirculation line 50 to the 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 coolant discharged from the stack S and the hydrogen passing through the hydrogen supply line 12 are mutually Here, since the cooling water discharged from the stack (S) has a higher 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 to the stack ( S) is supplied. The recirculation line 50 is a line for circulating the exhaust gas discharged from the stack (S) to the ejector (30), and the amount of hydrogen that is greater than the amount of hydrogen gas input to the stack (S) can react. Since it is supplied, the exhaust gas discharged from the stack S contains a significant amount of surplus hydrogen gas.

The control unit 60 is provided to adjust the amount of cooling water supplied to the heat exchanger 40 , and as a result, the temperature of the hydrogen gas supplied to the ejector 30 can be adjusted by adjusting the amount of the cooling water. As shown in FIG. 3 , the control unit 60 is installed on the hydrogen supply line 12 , and according to the pressure of the working fluid accommodated in the thermostat 62 and the thermostat 62 accommodating the working fluid. It consists of a pressure reducing valve (64) that operates and a communication pipe (63) communicating between the temperature sensing tube and the pressure reducing valve. Here, it is preferable that the thermosensitive tube 62 is provided to surround the outer periphery of the hydrogen supply line 12 in order to increase the heat transfer area.

As shown in FIG. 4, the pressure reducing valve 64 has a valve seat 66b having a port 66a formed at the inner center of the cooling water supply line 42 for supplying cooling water to the heat exchanger 40 in the axial direction. The extended partition wall 66, the housing 67 formed on the circumference of the cooling water input line 46 corresponding to the partition wall 66, the interior of the housing 67 is divided up and down, and the divided upper part and the thermal tube ( The diaphragm 68 provided to communicate with the diaphragm 62, the opening and closing member 69 installed on the lower surface of the diaphragm 68 to open and close the port 66a by the operation of the diaphragm 68, and the opening and closing member 69 ) consists of a spring 70 installed to elastically support.

The partition wall 66 is installed to cross the inside of the cooling water supply line 42 , and a valve seat 66b having a port 66a formed in the center thereof is provided to extend in the axial direction. The amount of cooling water supplied to the heat exchanger 40 is determined according to 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 wall 66 , and an opening 67a communicating with the thermostat 62 is formed at an upper portion of the housing 67 . It is preferable that the housing 67 has an annular 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. Here, the divided upper part 67b of the housing 67 is formed to communicate with the thermostat 62, and the divided lower surface of the housing 67 opens and closes the port 66a of the valve seat 66b. A member 69 is installed. Accordingly, in the diaphragm 68, when the temperature of the working fluid accommodated in the thermosensing vessel 62 rises and evaporates, the working fluid in the thermosensing vessel 62 expands and pushes the diaphragm 68. As shown in FIG. In addition, in the diaphragm 68, when the temperature of the working fluid accommodated in the thermosensor 62 is reduced and condensed, the working fluid in the thermosensing vessel 62 contracts and a negative pressure is formed to restore the diaphragm 68 to the state before expansion. make it

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 a port formed under the stem 69a It consists of a contact member (69b) in close contact with the (66a). The spring 70 is provided so that the opening/closing member 69 is elastically supported, and the contact member 69b is pressed by the spring 70 to seal the port 66a of the valve seat 66b. Accordingly, when the working fluid contained in the thermosensitive tube 62 is condensed and a negative pressure is formed beyond the level enough to overcome the tension of the spring 70, the diaphragm 68 operates and the coolant input line 46 is opened.

In the method for controlling the temperature of hydrogen gas supplied to the ejector according to the fuel cell hydrogen supply system for automobiles, the temperature of the hydrogen supplied to the fuel tank 10 is also increased because the temperature of the atmosphere is high in summer. Accordingly, the working fluid accommodated in the thermosensor 62 evaporates to increase the pressure, and the working fluid with the increased pressure moves to the upper portion of the housing 67 in communication with the thermosensing vessel 62 to move the diaphragm 68 down. will pressurize At this time, the opening/closing member 69 closes the port 66a formed in the valve seat 66b while maintaining the lowered state by the pressing force of the diaphragm 68 as well as the tension of the spring 70 . Therefore, the hydrogen supplied from the fuel tank 10 flows to the ejector 30 as it is at the temperature discharged from the fuel tank 10 because the coolant does not flow to the heat exchanger 40 .

Next, when the temperature decreases, the temperature of the hydrogen supplied to the fuel tank also decreases. When the temperature of the hydrogen supplied from the fuel tank 10 decreases, the working fluid contained in the thermal chamber 62 is condensed to decrease the pressure, thereby forming a negative pressure in the thermal chamber 62 . When a negative pressure is formed inside the thermosensitive tube 62, the diaphragm 68 overcomes the tension of the spring 70 as shown in FIG. 5 and is convexly bent upward. 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 coolant flows into the heat exchanger 40 to exchange heat with hydrogen, thereby increasing the temperature of the hydrogen supplied to the ejector 30 . As described above, the pressure reducing valve 64 operates to adjust the amount of cooling water in response to the rise and fall of the temperature, so that it is possible to adjust the relative humidity of hydrogen entering the stack S without a separate driving source. Accordingly, the fuel cell hydrogen supply system for a vehicle supplies hydrogen at an appropriate humidity to prevent flooding or dry-out, thereby further improving the efficiency of the fuel cell.

With reference to the drawings below, it will be described in detail with respect to the pressure reducing valve 64 of the present invention. The pressure reducing valve 64 of the present invention minimizes its volume and simplifies the configuration to avoid complexity, thereby increasing durability, and preventing interference on the communication pipe 63 during inspection or repair, the actuator in FIGS. 2 to 5 The housing 67 exposed to the outside and used to play the role of an actuator, the diaphragm 68 complicatedly configured inside the housing 67, and an additional configuration used to operate the housing 67 are not used. Instead, as shown in FIG. 7 , a balloon 80 that can change the volume, such as an airbag or balloon, is used as an actuator.

In FIG. 6 , the communication pipe 63 is fixed in direct contact with the coolant input line 46 . To this end, in the longitudinal direction of the coolant input line 46, the communication pipe fitting bracket 46a, which is perforated (with a hole formed) so as to fit the circumference of the body of the communication pipe 63, is vertical (b2), and , the outer peripheral body of the communication pipe 63 is tightly fitted through welding, bonding, etc., and is coupled to prevent leakage of water completely.

As shown in FIG. 6B, the end side of the communication pipe 63 is aligned along the length of the cooling water input line 46 in accordance with the flow direction (along the flow direction) to minimize the flow obstruction of the cooling water a3. It is bent at a right angle (b3) so as to be (b1), and the direction is changed from vertical (b2) to horizontal (b1). Thereafter, as shown in FIG. 6A, the open inlet of the balloon 80, that is, the balloon inlet 80a), is closely and firmly attached to the bent (b3) communication pipe end 63a to completely prevent leakage. The balloon 80 coupled to the end of the communication pipe 63 in this way naturally conforms to the flow direction of the cooling water a3 so that the resistance is minimized and aligned side by side in the longitudinal direction of the cooling water input line 46 ( b1) becomes

If the pressure (volume) of the working fluid (a1) accommodated in the thermostat 62 increases, the working fluid (a1) directly fills the balloon 80, and thus the volume of the balloon 80 increases (expansion). ), the volume (pressure) may change again due to the cooling water a3 in the cooling water input line 46 , so that the operation of the thermostat 62 may not be properly reflected. Therefore, it is necessary to thoroughly block the heat so that the change in volume is minimized again. It is desirable to minimize

However, since the balun 80 continues to contact the cooling water a3 even though a heat insulating member and a thick material are adopted, it is eventually affected by the temperature of the cooling water a3, so that the working fluid a1 is transferred to the cooling water input line. Another advanced method is needed which can not be affected at all from the cooling water a3 in (46). For this, a fluid having a minimal volume change (volume change) in response to thermal change can be adopted by diverting only the fluid filling the balloon 80, which is called the balloon filling fluid a2, and the balloon filling The fluid (a2) is preferably a fluid having a specific gravity (density, weight) different from that of the working fluid (a1). In the example of the drawings, the balloon filling fluid (a2) is selected as a fluid having a large specific gravity so as not to be mixed with the working fluid (a1). As shown in FIG. 6A , an interface a12 is generated due to a specific gravity difference between the working fluid a1 and the balloon filling fluid a2 in the communication pipe 63 .

An operation method will be described with reference to FIGS. 7 and 8 . First, when the pressure (volume) of the working fluid a1 accommodated in the thermostat 62 increases, the working fluid a1 pushes the balloon filling fluid a2, so in FIG. 8 , the interface a12 is the first It moves downward (c2) from the high point (d1) to the low point (d2). Accordingly, the volume change of the difference in the communication pipe 63, that is, the volume change d12 in the pipe, the balloon filling fluid a2 flows into the balloon 80, and when the balloon 80 is filled, the volume of the balloon 80 increases. It expands like a ball and eventually closes a section of the cooling water input line 46 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 balloon filling fluid (a2), so the interface (a12) moves upward from the low point to the high point (c1). Since the balloon filling fluid a2 is drawn out from the balloon 80 by the change d12, the volume of the balloon 80 is reduced to allow the flow of the coolant a3 again. At this time, if the balloon 80 is made of an elastic material such as rubber having elastic recovery force against volume change, the pressure of the working fluid a1 due to the elastic recovery force can be operated while maintaining an appropriate tension, FIG. 2 to 5 to perform the role of the spring 70 of the opening and closing member 69 illustrated in FIG.

As a result, the volume change of the balloon 80, that is, the change in the volume of the balloon e12, coincides with the change in the internal volume d12, and only the balloon filling fluid a2 instead of the working fluid a1 is used. Since the cooling water input line 46 is filled with the balloon 80 disposed inside, the working fluid a1 is not affected by the temperature of the cooling water a3 at all and only precisely by the influence of the thermosensitive tube 62 . it will work

In addition, although not shown in the drawing, the communication pipe 63 is adopted as a transparent member such as glass or transparent plastic for all or only a portion of the section in which the boundary surface moves, so that the movement (movement) of the boundary surface a12 from the outside It can be configured to be verified. Through this, the manager (checker, driver) may check and confirm whether the operation of the pressure reducing valve 64 is normal and take appropriate measures.

At this time, a dye may be added so that the working fluid a1 and the balloon filling fluid a2 have different colors from each other so that the interface a12 can be easily checked. Alternatively, a float having an intermediate specific gravity of the working fluid a1 and the balloon filling fluid a2 is inserted and interposed in the interface a12 to facilitate identification and confirmation. . The float serves to block the two fluids from contacting each other between the working fluid (a1) and the balloon filling fluid (a2), so that the two fluids do not mix with each other between the interface (a12). it can be

ejector 30; hydrogen supply line 12; stack (S); heat exchanger 40; recirculation line 50; control unit 60; Balloon (80); Balloon entrance (80a); communication pipe 63; Cooling water input line (46); coolant (a3);

Claims (1)

After the hydrogen charged in the fuel tank is adjusted to a constant pressure through the high-pressure regulator, the pressure is adjusted to the pressure that can be supplied to the stack through the low-pressure regulator, and a solenoid valve is installed between the high-pressure regulator and the low-pressure regulator to control the flow of hydrogen and an ejector supplies the hydrogen with the adjusted pressure to the stack, and a heat exchanger is disposed between the fuel tank and the ejector to exchange heat with hydrogen supplied through a hydrogen supply line and cooling water discharged from the stack,
The control unit adjusts the amount of cooling water supplied to the heat exchanger, is installed to surround the outer periphery on the hydrogen supply line, and according to the pressure of the working fluid (a1), the temperature sensing passage for accommodating the working fluid (a1), the actuator including a pressure reducing valve operated by
A communication pipe communicating between the temperature sensing tube and the pressure reducing valve is provided, and the communication pipe is fixed in contact with the cooling water input line, and is perforated to fit the body of the communication pipe above the cooling water input line in the longitudinal direction. The communication pipe fitting bracket (46a) is configured vertically,
The communication pipe end (63a) side of the communication pipe is bent and aligned (b1) side by side in the longitudinal direction of the cooling water input line, and the balun is coupled to the communication pipe end (63a) in the longitudinal direction of the cooling water input line. Aligned side by side (b1), to reduce the resistance in accordance with the flow of the coolant (a3),
When the pressure and volume of the working fluid (a1) accommodated in the thermostat increases, the working fluid (a1) directly fills the balloon so that the volume of the balloon expands;
A balloon filling fluid (a2) having a larger specific gravity than the working fluid (a1) is provided, and the interface (a12) due to the specific gravity difference between the working fluid (a1) and the balloon filling fluid (a2) in the communication pipe is generated so that they do not mix with each other, so that only the balloon filling fluid (a2) is diverted to fill the balloon,
The section of the interface (a12) in the communication pipe is adopted as a transparent member, so that the movement of the interface (a12) from the outside can be confirmed.

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