CN110416570B - A fuel cell hydrogen heating device - Google Patents

Abstract

A fuel cell hydrogen heating device relates to the field of fuel cells; it comprises a casing, 2 rows of heat exchange fins, 2n hydrogen gas split baffles and separators; the top of the casing is respectively provided with a heat exchanger inlet and a heat exchanger outlet The side wall of the shell is provided with a hydrogen inlet and a compressed air inlet; the side wall of the bottom end of the shell is provided with a hydrogen outlet and a compressed air outlet; the partition divides the inner cavity of the shell into a hydrogen cavity and a compressed air cavity; Two rows of heat exchange fins are vertically arranged in the center of the hydrogen cavity and the compressed air cavity; one row of heat exchange fins is communicated with the heat exchanger inlet; the other row of heat exchange fins is communicated with the heat exchanger outlet The hydrogen distribution baffle is symmetrically arranged inside the hydrogen cavity and the compressed air cavity; the invention uses the waste heat generated by the fuel cell stack and the system to heat the hydrogen entering from the cold source, and the temperature rise is uniform and controllable, avoiding the danger of electric heating and the like The heating method can provide high-temperature hydrogen for fuel cell power generation.

Description

A fuel cell hydrogen heating device

technical field

The invention relates to the field of fuel cells, in particular to a hydrogen heating device for fuel cells.

Background technique

Proton Exchange Membrane Fuel Cell (PEMFC) is different from the traditional internal combustion engine reaction mechanism. It directly converts chemical energy into electrical energy, which is not limited by the Carnot cycle, and the energy conversion efficiency is as high as 40% to 60%. As a new type of clean energy, it has the advantages of low noise, zero pollution, fast startup, high efficiency, large output current, and low operating temperature, and has been widely used in portable power supplies, stationary power supplies and vehicle power supplies.

Proton exchange membrane fuel cell fuel is greatly affected by test conditions, which mainly include factors such as pressure, temperature and air side humidity of air, hydrogen and coolant. At this stage, most fuel cell system controls mainly control factors such as air, hydrogen and coolant pressure, air humidity and temperature, and hydrogen circulation. However, the temperature and humidity of hydrogen are usually not controlled and managed in order to reduce the complexity of the system. Existing studies have shown that the temperature and humidity of hydrogen have little effect on fuel cell performance.

SUMMARY OF THE INVENTION

The purpose of the present invention is to overcome the above-mentioned deficiencies of the prior art, and provide a fuel cell hydrogen heating device, which utilizes the waste heat generated by the fuel cell stack and the system to heat the hydrogen entering from the cold source, and the temperature rise is uniform and controllable, avoiding electric heating, etc. A more dangerous heating method, which can provide high-temperature hydrogen for fuel cells to generate electricity.

Above-mentioned purpose of the present invention is achieved through the following technical solutions:

A fuel cell hydrogen heating device comprises a casing, 2 rows of heat exchange fins, 2n hydrogen splitting baffles and baffles; wherein the casing is a vertically placed hollow columnar structure; the tops of the casing are respectively provided with horizontal The heat exchanger inlet and the heat exchanger outlet; the side wall at the top end of the casing is provided with a hydrogen inlet and a compressed air inlet horizontally; the hydrogen inlet and the compressed air inlet are arranged oppositely; the side wall at the bottom end of the casing is horizontally provided with a hydrogen outlet and the compressed air outlet; wherein, the vertical direction of the hydrogen outlet corresponds to the hydrogen inlet; the vertical direction of the compressed air outlet corresponds to the compressed air inlet; Air cavity; 2 rows of heat exchange fins are vertically arranged in the center of the hydrogen cavity and the compressed air cavity; the top of one row of heat exchange fins is communicated with the heat exchanger inlet; the other row of heat exchange fins The top of the sheet is communicated with the heat exchanger outlet; the bottoms of the two rows of heat exchange fins are communicated; 2n hydrogen split baffles are symmetrically arranged inside the hydrogen cavity and the compressed air cavity;

In the above-mentioned fuel cell hydrogen heating device, the external heat exchanger enters the compressed air cavity from the heat exchanger inlet; fills the heat exchange fins in the compressed air cavity vertically downward; passes through the bottom of the casing , enter the heat exchange fins of the hydrogen cavity, and flow out from the heat exchanger outlet.

In the above-mentioned fuel cell hydrogen heating device, the hydrogen cavity and the compressed air cavity respectively correspond to n hydrogen split baffles; the n hydrogen split baffle cavities are staggered vertically and evenly and fixedly installed on the inner wall of the cavity; Among them, n hydrogen split baffles divide the hydrogen cavity into S-shaped flow channels; the other n hydrogen split baffles divide the compressed air cavity into S-shaped flow channels.

In the above-mentioned fuel cell hydrogen heating device, the external hydrogen to be heated enters the hydrogen cavity from the hydrogen inlet; flows vertically downward along the S-shaped flow channel to the bottom of the hydrogen cavity, and passes through the external heat exchange fins. The heat exchanger flows out from the hydrogen outlet after being heated.

In the above-mentioned fuel cell hydrogen heating device, the external compressed air enters the compressed air cavity from the compressed air inlet; flows vertically downward along the S-shaped flow channel to the bottom of the compressed air cavity; The external heat exchanger is heated and flows out from the compressed air outlet.

In the above-mentioned fuel cell hydrogen heating device, the width of the heat exchange fins is set as D; the width of the cavity is D; the distance between adjacent partition plates is l; the distance between the heat exchange fins and the inner wall of the cavity is h; the cross-sectional area of the hydrogen inlet is S; the thickness of the heat exchange fin is H; then:

1.5S≤D×l≤12S

1.5S≤h×l≤12S

0.3H≤h≤5H.

In the above fuel cell hydrogen heating device, the initial temperature of the external heat exchanger is 75°C to 85°C; the temperature of the external hydrogen to be heated is -40°C to 40°C; the initial temperature of the external compressed air is 20°C to 100°C.

The above-mentioned fuel cell hydrogen heating device is characterized in that: the compressed air cavity and the hydrogen cavity are made of aluminum alloy or copper material; and the heat exchange fins are made of aluminum alloy or copper material.

Compared with the prior art, the present invention has the following advantages:

(1) The present invention effectively uses the waste heat generated by the fuel cell system and the stack to heat the liquid water and gas source hydrogen in the circulating hydrogen, avoids the use of more dangerous heating methods such as electric heating, and can provide temperature for fuel cell power generation. higher hydrogen;

(2) In the present invention, the hydrogen tail gas enters the device before being circulated back to the fuel cell stack, and a small amount of liquid water generated after the tail gas or cooler hydrogen is mixed with the tail gas can be evaporated. road blockage, which affects the uniformity and stability of the stack; on the other hand, it can increase the humidity of the hydrogen inlet, reduce the internal resistance of the fuel cell, and improve the performance of the fuel cell;

(3) In the present invention, the air compression cavity, the hydrogen heat exchange cavity and the coolant cavity are cast from any one of aluminum alloy, copper, and materials with good heat exchange effect, and the heat exchange fins are made of aluminum alloy, copper, etc. Material with good heat transfer effect. After the hydrogen heat exchange, the temperature can be raised to about 60 °C, which can improve the performance of the fuel cell by 5% to 10%. stack, causing adverse effects on the stack.

Description of drawings

Fig. 1 is the sectional view of the hydrogen heating device of the present invention;

FIG. 2 is a schematic diagram of a heat exchange fin of the present invention.

Detailed ways

Below in conjunction with accompanying drawing and specific embodiment, the present invention is described in further detail:

The invention provides a device for hydrogen heating of fuel cells, which can be applied to fuel cell stacks and fuel cell systems of various powers, and effectively utilizes the waste heat generated by the fuel cell systems and the stacks to heat the liquid water in the circulating hydrogen gas. Heating with gas source hydrogen, avoiding the use of more dangerous heating methods such as electric heating, can provide high-temperature hydrogen for fuel cell power generation; at the same time, the hydrogen tail gas enters the device before being circulated back to the fuel cell stack, which can convert the tail gas or cooler hydrogen The evaporation of a small amount of liquid water generated after mixing with the exhaust gas prevents liquid water from entering the stack, causing blockage of some single-cell gas paths, affecting the uniformity and stability of the stack; on the other hand, it can increase the humidity of the hydrogen inlet and reduce the fuel consumption. The internal resistance of the battery improves the performance of the fuel cell.

Figure 1 is a cross-sectional view of a hydrogen heating device. It can be seen from the figure that a fuel cell hydrogen heating device includes a casing 16, 2 rows of heat exchange fins 6, 2n hydrogen split baffles 7 and separators 8; wherein, The casing 16 is a vertically placed hollow columnar structure; the top of the casing 16 is provided with a heat exchanger inlet 1 and a heat exchanger outlet 2 horizontally; at the side wall of the top of the casing 16, a hydrogen inlet 3 and a compression The air inlet 9; the hydrogen inlet 3 and the compressed air inlet 9 are arranged oppositely; the side wall of the bottom end of the casing 16 is provided with a hydrogen outlet 4 and a compressed air outlet 10 horizontally; wherein, the vertical direction of the hydrogen outlet 4 corresponds to the hydrogen inlet 3; The vertical direction of the compressed air outlet 10 corresponds to the compressed air inlet 9; the partition plate 8 is vertically arranged in the middle of the shell 16, and the inner cavity of the shell 16 is divided into a hydrogen cavity 5 and a compressed air cavity 11; 2 rows of heat exchange fins The fins 6 are arranged vertically in the center of the hydrogen cavity 5 and the compressed air cavity 11; the top of one row of heat exchange fins 6 is communicated with the heat exchanger inlet 1; the top of the other row of heat exchange fins 6 The bottoms of the two rows of heat exchange fins 6 are connected to each other;

The external heat exchanger enters the compressed air cavity 11 from the heat exchanger inlet 1; the heat exchange fins 6 in the compressed air cavity 11 are filled vertically downward; the heat exchange enters the hydrogen cavity 5 through the bottom of the shell 16 fins 6 and flow out from the heat exchanger outlet 2. The external heat exchange agent enters the heat exchange device through the heat exchange agent inlet 1, flows through the hydrogen cavity 5 where the heat exchange fins 6 are located, and flows out of the heat exchange device through the heat exchange agent outlet 2. The heat is conducted through the heat exchange fins 6 to the hydrogen with a lower temperature entering the hydrogen cavity 5 from the hydrogen inlet 3. After reaching the heat exchange temperature, the hydrogen flows out of the heat exchange device from the hydrogen outlet 4 and enters the stack to participate in the stack. reaction.

The hydrogen cavity 5 and the compressed air cavity 11 correspond to n hydrogen splitting baffles 7 respectively; the n hydrogen splitting baffles 7 are staggered and evenly fixed on the inner wall of the cavity in the vertical direction; wherein n hydrogen splitting baffles 7. Divide the hydrogen cavity 5 into S-shaped flow channels; in addition, n hydrogen dividing baffles 7 divide the compressed air cavity 11 into S-shaped flow channels. Due to the high heat capacity of hydrogen, a large heat exchange area is required. In order to reduce the volume of the hydrogen heating device and improve the heating efficiency of the hydrogen heating device, an increase in the interior of the hydrogen heat exchange cavity is made; n hydrogen split baffles 7, forcing Change the hydrogen flow direction and increase the heat exchange area.

The external hydrogen to be heated enters the hydrogen cavity 5 from the hydrogen inlet 3; flows vertically downward along the S-shaped flow channel to the bottom of the hydrogen cavity 5, and is heated by the external heat exchanger in the heat exchange fins 6 from the hydrogen outlet 4 outflow.

On the basis of the hydrogen-only heating device, a compressed air cavity 11 for air is added. The temperature of the air compressed by the air compressor is high. Before entering the stack, the compressed air enters the heat exchange device from the compressed air inlet 9, and after exchanging heat with the heat exchanger, it flows out from the compressed air outlet 10 and enters the stack. After the coolant exchanges heat with the high-temperature air, the hydrogen is heated after the temperature rises. The external compressed air enters the compressed air cavity 11 from the compressed air inlet 9; flows vertically downward along the S-shaped flow channel to the bottom of the compressed air cavity 11; Outlet 10 flows out.

Figure 2 shows the schematic diagram of the heat exchange fins. It can be seen from the figure that the width of the heat exchange fins is D; the width of the cavity is D; the distance between adjacent partition plates is l; the heat exchange fins and the inner wall of the cavity are The distance between them is h; the cross-sectional area of the hydrogen inlet 3 is S; the thickness of the heat exchange fins is H; then:

1.5S≤D×l≤12S

1.5S≤h×l≤12S

0.3H≤h≤5H.

The initial temperature of the external heat exchanger is 75°C to 85°C; the temperature of the external hydrogen to be heated is -40°C to 40°C; the initial temperature of the external compressed air is 20°C to 100°C.

The compressed air cavity 11 and the hydrogen cavity 5 are made of aluminum alloy, copper, or any material with good heat exchange effect. The heat exchange fins 6 are made of aluminum alloy, copper and other materials with good heat exchange effect. After the hydrogen heat exchange, the temperature can be raised to about 60 °C, which can improve the performance of the fuel cell by 5% to 10%. stack, causing adverse effects on the stack.

The content not described in detail in the specification of the present invention belongs to the well-known technology of those skilled in the art.

Claims (7)

1. A fuel cell hydrogen heating device, characterized in that: it comprises a casing (16), 2 rows of heat exchange fins (6), 2n hydrogen splitter baffles (7) and a separator (8); wherein, the shell The body (16) is a vertically placed hollow columnar structure; the top end of the casing (16) is provided with a heat exchanger inlet (1) and a heat exchanger outlet (2) horizontally; , a hydrogen inlet (3) and a compressed air inlet (9) are arranged horizontally; the hydrogen inlet (3) and the compressed air inlet (9) are arranged oppositely; at the side wall of the bottom end of the casing (16), a hydrogen outlet (4) is arranged horizontally ) and a compressed air outlet (10); wherein, the hydrogen outlet (4) corresponds to the hydrogen inlet (3) in the vertical direction; the compressed air outlet (10) corresponds to the compressed air inlet (9) in the vertical direction; The plate (8) is vertically arranged in the middle of the shell (16), and divides the inner cavity of the shell (16) into a hydrogen cavity (5) and a compressed air cavity (11); two rows of heat exchange fins (6) are distributed Vertically arranged at the center of the interior of the hydrogen cavity (5) and the compressed air cavity (11); the top of one row of heat exchange fins (6) is communicated with the heat exchanger inlet (1); the other row of heat exchange fins (6) The tops of the fins (6) are communicated with the heat exchanger outlet (2); the bottoms of the two rows of heat exchange fins (6) are communicated; 2n hydrogen split baffles (7) are symmetrically arranged on the hydrogen cavity (5) and the compression Inside the air cavity (11); n is an integer greater than or equal to 2. 2. A fuel cell hydrogen heating device according to claim 1, characterized in that: the external heat exchanger enters the compressed air cavity (11) from the heat exchanger inlet (1); the compressed air is filled vertically downward. The heat exchange fins (6) in the cavity (11) enter the heat exchange fins (6) of the hydrogen cavity (5) through the bottom of the casing (16), and flow out from the heat exchanger outlet (2). 3. A fuel cell hydrogen heating device according to claim 2, characterized in that: the hydrogen cavity (5) and the compressed air cavity (11) respectively correspond to n hydrogen splitter baffles (7); n hydrogen The shunt baffles (7) are staggered and evenly fixed on the inner wall of the cavity in the vertical direction; n hydrogen shunt baffles (7) divide the hydrogen cavity (5) into S-shaped flow channels; the other n hydrogen shunts The baffle (7) divides the compressed air cavity (11) into S-shaped flow channels. 4. A fuel cell hydrogen heating device according to claim 3, characterized in that: the external hydrogen to be heated enters the hydrogen cavity (5) from the hydrogen inlet (3); flows vertically downward along the S-shaped flow channel to The bottom of the hydrogen cavity (5) flows out from the hydrogen outlet (4) after being heated by the external heat exchanger in the heat exchange fins (6). 5. A fuel cell hydrogen heating device according to claim 4, characterized in that: external compressed air enters the compressed air cavity (11) from the compressed air inlet (9); flows vertically downward along the S-shaped flow channel to the bottom of the compressed air cavity (11); after being heated by the external heat exchange agent in the heat exchange fins (6), it flows out from the compressed air outlet (10). 6. A fuel cell hydrogen heating device according to claim 5, characterized in that: the width of the heat exchange fins is set to be D; the width of the cavity is D; the distance between adjacent hydrogen splitter baffles (7) is I; the distance between the heat exchange fin and the inner wall of the cavity is h; the cross-sectional area of the hydrogen inlet (3) is S; the thickness of the heat exchange fin is H; then: 1.5S≤D×I≤12S 1.5S≤h×I≤12S 0.3H≤h≤5H. 7. A fuel cell hydrogen heating device according to claim 6, characterized in that: the compressed air cavity (11) and the hydrogen cavity (5) are made of aluminum alloy or copper material; heat exchange fins (6) ) using aluminum alloy or copper material.

Images