KR102697537B1 - Cooling system for hydrogen fuel cell vehicles - Google Patents

Abstract

The present invention provides a cooling system for a hydrogen fuel cell vehicle, which includes a fuel cell stack, a motor that operates using electric energy generated from the fuel cell stack, and a radiator, wherein an exhaust water trap for storing water (W) discharged from the fuel cell stack is provided on one side of the fuel cell stack, and a condensation pipe for capturing moisture condensed on the surface of an air conditioner evaporator in the summer is connected to a lower portion of the exhaust water trap.

Description

Cooling system for hydrogen fuel cell vehicles

The present invention relates to a cooling system for a hydrogen fuel cell vehicle, and more specifically, to a cooling system for a hydrogen fuel cell vehicle with improved cooling performance.

In general, unlike conventional internal combustion engine vehicles that generate power by converting chemical energy into mechanical energy through an explosive reaction between fossil fuel and oxygen in the air inside the engine, hydrogen fuel cell vehicles use the electrical energy generated by electrical and chemical reactions between hydrogen supplied through a high-pressure hydrogen tank or reformer and oxygen in the air supplied through an air compressor inside a fuel cell stack to power the vehicle.

That is, a fuel cell stack is a device that directly converts the energy of fuel into electrical energy. It is a system that places a pair of electrodes, an anode and a cathode, between a normal electrolyte and obtains both electricity and heat through the electrochemical reaction of ionized fuel gas.

Polymer electrolyte fuel cells have the advantages of high current density, low operating temperature, and low corrosion and electrolyte loss, and so they began to be developed as a power source for military and space vehicles. However, research is currently being actively conducted to apply them as a power source for vehicles such as buses, taking advantage of their high output density, simple device design, and modularization capabilities.

Meanwhile, hydrogen fuel cell buses using batteries and electric motors are being developed to address the problem of global warming caused by exhaust gas emissions from buses running in the city.

In the case of electric vehicles powered by hydrogen fuel cells, heat is generated from the fuel cell stack and power electric components such as motors and inverters. Therefore, as shown in Fig. 1, a radiator through which coolant circulates is used to absorb the heat generated from the fuel cell stack and power electric components, thereby cooling the system.

In addition, hydrogen fuel cell buses and trucks must generate high output even under harsh driving conditions, such as carrying a large number of passengers or loading heavy cargo, which dramatically increases the heat generated from the hydrogen fuel cell system.

In particular, for hydrogen fuel cell vehicles, the heat rising from the ground and radiation from the sun in the summer must also be taken into consideration. If the heat generated in a hydrogen electric vehicle in the summer cannot be properly cooled, the vehicle itself may become impossible to operate, so sufficient cooling performance is required.

1. Republic of Korea Patent Publication No. 10-2022-0088969 (Published on June 28, 2022)

The present invention relates to a cooling system for a hydrogen fuel cell vehicle, and more specifically, to provide a cooling system for a hydrogen fuel cell vehicle with improved cooling performance.

The present invention provides a cooling system for a hydrogen fuel cell vehicle, which includes a fuel cell stack, a motor that operates using electric energy generated from the fuel cell stack, and a radiator, wherein an exhaust water trap for storing water (W) discharged from the fuel cell stack is provided on one side of the fuel cell stack, and a condensation pipe for capturing moisture condensed on the surface of an air conditioner evaporator in the summer is connected to a lower portion of the exhaust water trap.

According to one embodiment, an injection device is provided at the front or rear of the radiator, an injection pump is provided at the rear end of the exhaust water trap, and the injection pump pressurizes water (W) and supplies it to the injection device.

According to one embodiment, a compressed air pipe is connected to one central side of the spray device, and a plurality of droplet discharge ports are arranged at regular intervals along the horizontal and vertical directions on the other side.

According to one embodiment, the droplet discharge port includes an inlet portion, a neck portion extending from the inlet portion and having a smaller area than the inlet portion, and an outlet portion extending from the neck portion and having a larger area than the neck portion.

According to one embodiment, a cylindrical injection device is provided around the motor, and an injection pump is provided behind the exhaust water trap, and the injection pump pressurizes water (W) and supplies it to the injection device.

The present invention effectively cools a fuel cell stack or a motor, particularly in the summer, by utilizing the latent heat of vaporization of water (W) discharged from a fuel cell stack and moisture condensed on the surface of an evaporator by spraying the water (W) discharged from a fuel cell stack and moisture condensed on the surface of an evaporator in an atomized state onto a radiator or a motor surface.

Figure 1 is a conceptual diagram of a cooling system for a hydrogen fuel cell vehicle according to conventional technology.
Figure 2 is a conceptual diagram of a cooling system of a hydrogen fuel cell vehicle without an injection device according to the present invention.
Figure 3 is a conceptual diagram of a cooling system of a hydrogen fuel cell vehicle equipped with an injection device according to the present invention.
Figures 4(a) and (b) are a perspective view and a cross-sectional view, respectively, of an injection device according to the present invention.
Figure 5 is a perspective view of a spray pipe according to the present invention.
Figure 6 is a conceptual diagram of a motor cooling system according to the present invention.
Figure 7 is a perspective view of a motor cooling system according to the present invention.
Figure 8 is a perspective view of a spray pipe applied to a motor cooling system according to the present invention.

The embodiments of the present disclosure are provided for the purpose of explaining the technical idea of the present disclosure. The scope of rights according to the present disclosure is not limited to the embodiments presented below or the specific description of these embodiments.

All technical and scientific terms used in this disclosure, unless otherwise defined, have the meaning commonly understood by one of ordinary skill in the art to which this disclosure belongs. All terms used in this disclosure have been selected for the purpose of more clearly describing this disclosure and are not selected to limit the scope of rights under this disclosure.

The expressions “including,” “comprising,” “having,” and the like, used in this disclosure, should be understood as open-ended terms implying the possibility of including other embodiments, unless otherwise stated in the phrase or sentence in which the expression is included.

The singular forms described in this disclosure may include plural meanings unless otherwise stated, and the same applies to the singular forms described in the claims.

Example 1

Referring to FIG. 2, a hydrogen fuel cell vehicle according to one embodiment of the present invention may include a fuel cell stack (10), a motor (20) that operates using electric energy generated from the fuel cell stack (10), and a radiator (30).

A fuel supply device (11) that supplies hydrogen and an oxygen supply device (12) that supplies oxygen can be connected to the above fuel cell stack (10) through pipes (111, 112).

The above fuel cell stack (10) can generate driving force (E) as electrical energy from the chemical reaction energy of oxygen and hydrogen, and the driving force (E) can drive a motor (20) inside a hydrogen fuel cell vehicle.

Inside the fuel cell stack (10), heat energy is generated by the chemical reaction of hydrogen and oxygen, and the generated heat can be effectively removed using a radiator (30).

Again, referring to FIG. 2, a coolant pump (32) may be placed on one side of the fuel cell stack (10), and a radiator (30) may be placed on the front, rear, or side of the vehicle.

The above fuel cell stack (10), cooling water pump (32), and radiator (30) can be connected to each other by pipes (31, 33, 35) located between each part.

Therefore, the heat generated during the chemical reaction between hydrogen and oxygen in the fuel cell stack (10) can be transferred to the coolant and dissipated to the outside through the radiator (30).

Meanwhile, although not shown in the drawing, the cooling system of the hydrogen fuel cell vehicle of the present invention may further be provided with an electrical component cooling path for cooling the electrical components.

The above-mentioned electrical components may be at least one of a LDC (Low DC-DC Converter), an HDC (High DC-DC Converter), an FDC (Fuel-Cell DC-DC Converter, a hydrogen battery charging converter), a high voltage junction box (High Voltage Junction Box for Automotive Vehicles) or an MCU (Motor Control Unit), and an EHP (Electric Heat Pump).

Coolant for the electrical components can be circulated by being delivered to the electrical components radiator (not shown) through the electrical components cooling path (not shown).

Here, when the hydrogen electric bus first starts or runs at low speeds, only the electrical components are operated so that the vehicle is driven solely by electricity, and only the radiator for the electrical components can be operated to cool the electrical components.

Referring to Fig. 3, a water trap (51) may be further provided on one side of the fuel cell stack (10).

The above water trap (51) is intended to store water (W) discharged from the fuel cell stack (10) and may be a sealed container having a volume proportional to the capacity of the fuel cell stack (10).

A humidifier (52) may be provided at the rear end of the above water trap (51).

An exhaust water trap (53) may be provided at the rear end of the above humidifier (52).

The above exhaust water trap (53) can separately separate the gas discharged together with water (W) from the fuel cell stack (10) and exhaust it to the outside.

A condensation pipe (514) may be connected to the lower portion of the above exhaust water trap (53) to capture moisture condensed on the surface of the air conditioner evaporator (40) in the summer.

Accordingly, the temperature of the water (W) stored in the exhaust water trap (53) can be sufficiently lowered to cool the radiator (30) by the condensate flowing in from the evaporator surface.

An injection pump (54) may be provided at the rear end of the above exhaust water trap (53). The injection pump (54) can pressurize water (W) and supply it to an injection device (56) described later.

Meanwhile, the exhaust water trap (53) may be equipped with a water level detection sensor (not shown) that detects the water level of the stored water (W). The control unit (not shown) may control the discharge of water (W) only when the water level of water (W) is above a certain value.

The above water trap (51), humidifier (52), exhaust water trap (53), injection pump (54), and injection device (56) can be connected to each other by pipes (511, 512, 513, 515, 517).

The above exhaust water trap (53) may further be equipped with a temperature sensor (not shown) that detects the temperature of the stored water (W).

Additionally, a control valve (not shown) may be additionally provided at the front or rear of the injection pump (54).

Accordingly, the control unit can control to spray water (W) only when the temperature of the water (W) is within a set range, or can control the spray amount of water (W) by controlling the spray pump (54) and the control valve.

Referring to Fig. 4(a), an injection device (56) may be provided at the front or rear of the radiator (30).

The above-mentioned injection device (56) may have a body (561) in the shape of a rectangular solid.

A compressed air pipe (516) may be connected to one side of the center of the above-mentioned injection device (56), and a plurality of droplet discharge ports (563) may be arranged at regular intervals along the horizontal and vertical directions on the other side.

An air compression device (55) may be provided at the front end of the above compressed air pipe (516).

Referring to Fig. 4(b), the compressed air pipe (516) and the plurality of droplet discharge ports (563) can be connected to each other through a communication portion (562) formed inside the injection device (56).

The above droplet discharge port (563) may include an inlet portion (5631), a neck portion (5632) extending from the inlet portion (5632) and having a smaller area than the inlet portion (5631), and an outlet portion (5633) extending from the neck portion (5632) and having a larger area than the neck portion (5632).

And, water (W) supplied under pressure from the injection pump (54) can be supplied to the injection device (56) through the injection pipe (517).

Referring to FIG. 5, the injection pipe (517) may include a main pipe (5171) formed vertically and a plurality of branch pipes (5172) arranged at regular intervals along the height direction from the main pipe (5171).

The end of the above main pipe (5171) is closed.

In the above branch pipe (5172), a discharge port (d) can be formed at a position corresponding to the neck (5632) of the droplet discharge port (563), and the terminal portion of the above branch pipe (5172) is closed.

Accordingly, water (W) introduced through the injection pipe (517) can be entrained toward the droplet discharge port (563) by the air flow that accelerates at the neck (5632) through the main pipe (5171) and the branch pipe (5172).

Additionally, the water (W) can be sprayed toward the radiator (30) in the form of fine droplets by compressed air and a nozzle (5632).

Since the water (W) sprayed from the above droplet discharge port (563) is in an atomized state, not only does the area in contact with the radiator (30) increase compared to when the same amount of water is sprayed, but also the heat of the cooling water circulating inside the radiator (30) can be effectively removed through latent heat while evaporating from the surface of the radiator (30).

Meanwhile, the spacing between the plurality of droplet discharge ports (563) can be widened as they get farther away from the center of the radiator (30). Accordingly, the amount of water (W) sprayed due to stagnant pressure at the end of the branch pipe (5172) can be prevented from increasing and can be sprayed evenly on the surface of the radiator (30).

As described above, the present invention can effectively cool the fuel cell stack (10) by using the latent heat of vaporization by spraying water (W) discharged from the fuel cell stack (10) and moisture condensed on the surface of the evaporator in a fine particle state onto the surface of the radiator.

Second Example

In the second embodiment, descriptions of the same configuration as in the first embodiment will be omitted and only the differences will be described.

The second embodiment differs from the first embodiment in the configuration for directly cooling the motor (20).

Referring to FIG. 6, in the second embodiment of the present invention, water (W) discharged from the injection pump (54) can be directed toward the motor (20).

The above motor (20) may be a waterproof motor that prevents the inflow of liquid.

Referring to Fig. 7, a cylindrical injection device (56) may be provided around the motor (20).

The inner surface of the above-mentioned injection device (56) can be arranged radially spaced apart from the outer surface of the motor (20).

A compressed air pipe (516) may be connected to one side of the center of the above cylindrical injection device (56), and a plurality of droplet discharge ports (563) may be arranged at regular intervals along the circumferential and axial directions on the other side.

And, water (W) supplied under pressure from the injection pump (54) can be supplied to the injection device through the injection pipe (517).

Referring to FIG. 8, the injection pipe (517) can be supplied into the injection device (56) through a main pipe (5171) formed vertically and a plurality of branch pipes (5172) arranged at regular intervals along the axial direction from the main pipe (5171).

The above branch pipe (5172) may have an arc shape with both ends closed, and a discharge port (d) may be formed at a position corresponding to the neck (5632) of the droplet discharge port (563).

As described above, the present invention sprays water (W) discharged from a fuel cell stack (10) and moisture condensed on the surface of an evaporator in a fine particle state onto the surface of a radiator, thereby increasing the area of contact with the motor (20), and effectively cools the motor (20) by utilizing latent heat of vaporization on the surface of the motor (20).

Although the above-described embodiments have described the most preferred examples of the present invention, it is not limited to the above-described embodiments, and it is obvious to a person skilled in the art that various modifications are possible within a scope that does not depart from the technical spirit of the present invention.

10: Fuel cell stack
11: Fuel supply device
12: Oxygen supply device
30 : Radiator
32: Coolant pump
40 : Evaporator
51 : Water Trap
52 : Humidifier
53: Exhaust water trap
54 : Injection pump
55 : Compressed air device
56: Injector
563 : Droplet outlet

Claims (5)

A cooling system for a hydrogen fuel cell vehicle including a fuel cell stack, a motor that operates using electric energy generated from the fuel cell stack, and a radiator,
An exhaust water trap is provided on one side of the above fuel cell stack to store water (W) discharged from the fuel cell stack.
A condensation pipe is connected to the bottom of the above exhaust water trap to collect moisture condensed on the surface of the air conditioner evaporator in the summer.
An injection device is provided at the front or rear of the above radiator, and an injection pump is provided at the rear end of the above exhaust water trap, and the injection pump pressurizes water (W) and supplies it to the injection device.
A compressed air pipe is connected to one side of the center of the above-mentioned injection device, and a plurality of droplet discharge ports are arranged at regular intervals along the horizontal and vertical directions on the other side.
A cooling system for a hydrogen fuel cell vehicle, wherein the liquid droplet discharge port includes an inlet, a neck extending from the inlet and having a smaller area than the inlet, and an outlet extending from the neck and having a larger area than the neck. delete delete delete In the first paragraph,
A cooling system for a hydrogen fuel cell vehicle, wherein a cylindrical injector is provided around the motor, an injection pump is provided behind the exhaust water trap, and the injection pump pressurizes water (W) and supplies it to the injection device.