CN214152950U - Heat exchange device and fuel cell system - Google Patents

Abstract

The utility model discloses a heat transfer device and fuel cell system belongs to the fuel cell field. The utility model discloses a fuel cell system includes the pile, positive pole gas mixture cavity and coolant liquid cavity, heat transfer device includes first heat transfer unit and second heat transfer unit, first heat transfer unit is located positive pole gas mixture cavity indoor, second heat transfer unit is located the coolant liquid cavity indoor, the second heat transfer unit can carry out the heat transfer with the high temperature coolant liquid that comes out in the pile, and pass to first heat transfer unit with the heat, and then first heat transfer unit can heat the hydrogen gas mixture before getting into the pile. The temperature of the hydrogen mixed gas before the anode of the fuel cell enters the galvanic pile is close to the proper temperature of the system, and the risk that excessive condensed liquid water of the anode hydrogen mixed gas enters the galvanic pile is avoided. And the scheme has high energy utilization rate, does not need an external heat source, optimizes the water heating management mode of the electric pile, integrates the whole heat exchange device with the electric pile end plate, and has compact structure and high space utilization rate.

Description

Heat exchange device and fuel cell system

Technical Field

The utility model relates to a fuel cell field especially relates to a heat transfer device and fuel cell system.

Background

In order to improve the performance of a fuel cell system, improve the utilization rate of hydrogen and improve the water balance of the system, an anode reflux system is adopted in the fuel cell system, namely, the reaction gas of the anode hydrogen of the fuel cell is excessively supplied to an electric pile, part of hydrogen is consumed by the electrochemical reaction of the electric pile, the rest hydrogen and reaction products are mixed and discharged out of the electric pile, the discharged mixture is driven to reflux by a driving device (a hydrogen circulating pump or an ejector), and is mixed with the newly supplied hydrogen before the inlet of the anode of the electric pile to enter the electric pile again.

First, to improve the performance of the fuel cell system, the anode-in-stack mixture needs to be controlled within a suitable temperature range. However, in fuel cell anode return systems, the stack mixture temperature is typically 60-90 degrees, significantly higher than ambient temperature. The anode stack-out mixture can dissipate heat to the environment through the wall in the flowing process of the return circuit, and the temperature is gradually reduced. The fresh hydrogen is supplied from a hydrogen bottle, and the supply temperature is close to the ambient temperature. The temperature will further decrease when the reflux mixture is mixed with fresh supply hydrogen. Particularly, under the condition of cold-state environmental operation in winter, the environmental temperature is low, and the heat dissipation capacity of the wall surface to the environment is large; the temperature of the fresh hydrogen in the hydrogen bottle is low, and the temperature is further reduced after the fresh hydrogen is mixed with the backflow hydrogen.

Second, excessive condensation of liquid water is avoided in the fuel cell anode stack mixture. The fuel cell stack is formed by stacking hundreds of single-chip units, each single-chip unit comprises a plurality of airflow micro-channels, the density difference between gas phases and liquid phases of water is large, the content of liquid water directly influences the flowing state of gas in a fuel cell system channel, and the gas transmission channel can be blocked under the condition of serious liquid water accumulation to influence the normal operation of the system. Liquid water in fuel cell anode stack mixtures can be generated for a number of reasons, for example: liquid water drops in the piled mixture are well separated in a gas-liquid separation structure or a device at the anode outlet of the galvanic pile, but the situation that downstream gaseous water vapor is pre-cooled in a return pipeline and condensed into liquid water again is difficult to avoid; the pressure of the hydrogen side of the fuel cell system is instantaneously adjusted according to the operation condition, the pressure of different positions of the hydrogen side is different, and liquid water can be generated; when the temperature of the reflux mixture is reduced after mixing with the fresh supply of hydrogen, liquid condensate will also separate out. Particularly, in the low-temperature environment and the starting and warming process of the fuel cell system, the phenomenon of water vapor condensation is more prominent, and the normal operation of the system is influenced under severe conditions.

In the prior art, the technical scheme aiming at the problem of piling of the anode condensed liquid water is mainly two: the first scheme is that a water dividing structure is arranged before the hydrogen reflux system enters the reactor, and the water dividing structure is arranged before the hydrogen reflux system enters the reactor to separate condensed water generated at the upstream and prevent the condensed water from entering the reactor. The disadvantage of this kind of scheme is that the drainage structures need to be set up to the structure that divides water, and drainage structures has the risk of freezing, freezing especially under low temperature environment. The second scheme is that a water diversion structure is arranged in a water diversion reactor, and in order to relieve the influence of liquid water after entering the galvanic pile, a bypass unit is additionally arranged in the galvanic pile in patents US7163760B2 and US2018/0342744A1, and the liquid water is diverted. The hydrogen bypass unit is additionally arranged on the inner side of the galvanic pile close to the end plate, and a circulation channel for communicating a hydrogen inlet cavity with a hydrogen outlet cavity is arranged in the bypass unit. After the hydrogen side reactor entering mixture enters the reactor, the mixture firstly flows through the bypass unit, and part of liquid water entering the reactor flows to the hydrogen outlet cavity through the bypass channel to be discharged out of the reactor, so that the risk of liquid water entering a normal reaction unit at the downstream of the bypass unit is reduced. However, the addition of the bypass unit in the scheme can increase the length of the stack, affect the internal sealing reliability and the contact pressure distribution of the stack, and even relate to the overall performance of the stack. The scheme has more implementation influence variables and large adaptation and adjustment difficulty.

However, in the prior art, the related art for the temperature control of the anode mixture involves little.

Therefore, it is desirable to provide a heat exchange device and a fuel cell system to solve the above-mentioned problem of liquid water entering into a stack due to a large amount of condensed liquid water generated due to poor temperature control.

SUMMERY OF THE UTILITY MODEL

An object of the utility model is to provide a heat transfer device and fuel cell system can realize that the temperature of the hydrogen gas mixture before fuel cell system positive pole piling is close the suitable temperature of end plate integrated form battery system, avoids the excessive condensation of the hydrogen gas mixture of positive pole to produce liquid water simultaneously and then gets into the risk of galvanic pile.

In order to realize the purpose, the following technical scheme is provided:

the utility model provides a heat transfer device for fuel cell system, fuel cell system includes galvanic pile, positive pole gas mixture cavity and coolant liquid cavity, heat transfer device includes first heat transfer unit and second heat transfer unit, first heat transfer unit is located in the positive pole gas mixture cavity, second heat transfer unit is located in the coolant liquid cavity, second heat transfer unit can with the high temperature coolant liquid that comes out in the galvanic pile carries out the heat transfer to reach the heat first heat transfer unit, and then first heat transfer unit can heat the hydrogen gas mixture that gets into before the galvanic pile.

Further, the first heat exchange unit and the second heat exchange unit are both composed of a plurality of fins.

Further, the heat exchange device comprises at least one of the following modes:

the first mode is as follows: the multiple fins of the first heat exchange unit are arranged in a row from the air inlet to the air outlet of the anode mixed gas chamber;

the second mode is as follows: and the fins of the second heat exchange unit are arranged in a row from the liquid inlet to the liquid outlet of the cooling liquid cavity.

Further, in the first aspect, the plurality of fins of the first heat exchange unit are arranged in parallel with each other;

and/or, in the second mode, the plurality of fins of the second heat exchange unit are arranged in parallel with each other.

Further, fin surfaces of a plurality of fins of the first heat exchange unit are vertical to the direction of the airflow;

and/or the fin surfaces of the plurality of fins of the second heat exchange unit are perpendicular to the liquid flow direction.

Furthermore, the plurality of fins of the first heat exchange unit are arranged in an obliquely upward manner from the air inlet side to the air outlet side of the anode mixed gas chamber.

Furthermore, the heat exchange device also comprises a heat exchange plate, and the first heat exchange unit and the second heat exchange unit are both in contact with the heat exchange plate.

The utility model also provides a fuel cell system, including above arbitrary technical scheme heat transfer device.

Further, the air inlet of the anode mixed gas chamber is arranged above one side, and the air outlet is arranged below the opposite side of the air inlet;

and/or the liquid inlet of the cooling liquid cavity is arranged above one side, and the liquid outlet is arranged below the opposite side of the liquid inlet.

Further, be provided with first export, second export, first import and second import on the pile end plate, fuel cell system still includes vapour and liquid separator, hydrogen storage device, ejector and tail valve of arranging, first exit linkage vapour and liquid separator's import, the A import of ejector through first pipeline with vapour and liquid separator's exit linkage, the B import of ejector with hydrogen storage device's exit linkage, the export of ejector with the air inlet of positive pole gas mixture cavity is connected, the import of tail valve of arranging with first tube coupling, the gas outlet of positive pole gas mixture cavity with first access linkage, the second export with the inlet of coolant liquid cavity is connected, the liquid outlet of coolant liquid cavity with the second access linkage.

Compared with the prior art, the utility model provides a heat transfer device and fuel cell system, the high temperature coolant liquid that comes out in second heat transfer unit and the pile carries out the heat transfer to first heat transfer unit with the heat, and then first unit can heat the hydrogen gas mixture before getting into the pile, so realized with the heat transfer of the high temperature coolant liquid that comes out in the pile to the heat conversion of the hydrogen gas mixture before getting into the pile. The temperature of the high-temperature cooling liquid from the electric pile belongs to the control target temperature of the fuel cell heat management system, and the temperature of the hydrogen mixture before the anode of the fuel cell enters the electric pile can be close to the proper temperature of the system by exchanging heat with the high-temperature cooling liquid from the electric pile, and meanwhile, the risk that the liquid water enters the electric pile due to excessive condensation of the anode hydrogen mixture is avoided. Meanwhile, the scheme has high energy utilization rate, does not need an external heat source, optimizes the water heating management mode of the galvanic pile, integrates the whole heat exchange device with a galvanic pile end plate, and has compact structure and high space utilization rate.

Drawings

Fig. 1 is a schematic structural view of a fuel cell system of the present embodiment;

FIG. 2 is a schematic structural diagram of a heat exchange device according to this embodiment;

FIG. 3 is a schematic structural diagram of an anode mixed gas chamber according to the present embodiment;

FIG. 4 is a schematic structural view of a cooling liquid chamber according to the present embodiment;

FIG. 5 is an assembly view of the anode mixture chamber, the heat exchange device and the cooling liquid chamber according to the present embodiment;

FIG. 6 is a cross-sectional view taken along line D-D of FIG. 5;

FIG. 7 is an assembly diagram of the anode mixture chamber, the heat exchange device, the coolant chamber and the end plate of the stack according to the embodiment;

FIG. 8 is a schematic view of another embodiment of an anode mixture chamber and heat exchange device assembled;

FIG. 9 is a schematic view of an assembly of an anode mixture chamber, a heat exchange device and a coolant chamber according to another embodiment;

fig. 10 is a sectional view taken along a-a in fig. 9.

Reference numerals:

1-a hydrogen storage device; 2-a pressure reducing valve; 3-a control valve; 4-an ejector; 5-anode mixed gas chamber; 5 a-an air inlet; 5 b-gas outlet; 5 c-first seal groove; 6-a coolant chamber; 6 a-a liquid inlet; 6 b-a liquid outlet; 6 c-second seal groove; 7-a heat exchange device; 7 a-a first heat exchange unit; 7 b-a second heat exchange unit; 7 c-a heat exchange plate; 8-stack end plate; 8 a-a first inlet; 8 b-a first outlet; 8 c-a second inlet; 8 d-a second outlet; 9-electric pile; 10-a gas-liquid separator; 11-tail discharge valve.

Detailed Description

In order to make the technical problems, technical solutions adopted and technical effects achieved by the present invention clearer, the embodiments of the present invention will be described in further detail with reference to the accompanying drawings, and obviously, the described embodiments are only some embodiments, not all embodiments of the present invention. Based on the embodiments in the present invention, all other embodiments obtained by the skilled in the art without creative work belong to the protection scope of the present invention.

As shown in fig. 1, the present embodiment provides a fuel cell system, particularly an end plate integrated fuel cell, which includes a stack 9, an anode mixture chamber 5, a coolant chamber 6, and a heat exchanging device 7, wherein the heat exchanging device 7 is disposed between the anode mixture chamber 5 and the coolant chamber 6. Specifically, be provided with first export 8B on the pile end plate 8, second export 8d, first import 8a and second import 8c, the fuel cell system still includes vapour and liquid separator 10, hydrogen storage device 1, ejector 4 and tail valve 11, the import of vapour and liquid separator 10 is connected to first export 8B, the A import of ejector 4 is through the exit linkage of first pipeline with vapour and liquid separator 10, the B import of ejector 4 and hydrogen storage device 1's exit linkage, the export of ejector 4 is connected with the air inlet 5a of positive pole gas mixture cavity 5, the import and the first tube coupling of tail valve 11, the gas outlet 5B and the first import 8a of positive pole gas mixture cavity 5 are connected, second export 8d is connected with inlet 6a of coolant liquid cavity 6, the liquid outlet 6B and the second import 8c of coolant liquid cavity 6 are connected. Alternatively, the ejector 4 of the present embodiment may be replaced with a circulation pump as long as it can pump out the gaseous mixture and the hydrogen gas as a power source.

Optionally, referring to fig. 1, the fuel cell system of this embodiment further includes a pressure reducing valve 2 and a control valve 3, where the pressure reducing valve 2 and the control valve 3 are sequentially connected to a pipeline from an outlet of the hydrogen storage device 1 to an inlet B of the ejector 4, and function to reduce pressure of the pumped fresh hydrogen.

Referring to fig. 1 to 4, the heat exchange device 7 includes a first heat exchange unit 7a and a second heat exchange unit 7b, the first heat exchange unit 7a is located in the anode mixed gas chamber 5, the second heat exchange unit 7b is located in the coolant chamber 6, the second heat exchange unit 7b can exchange heat with the high-temperature coolant coming out of the galvanic pile 9, and transfer heat to the first heat exchange unit 7a, and then the first heat exchange unit 7a can heat the hydrogen mixed gas before entering the galvanic pile 9.

The second heat exchange unit 7b of the heat exchange device 7 of this embodiment exchanges heat with the high temperature coolant liquid that comes out in the galvanic pile 9 to pass to first heat exchange unit 7a with the heat, and then first unit can heat the hydrogen gas mixture before getting into galvanic pile 9, so realized transferring the heat of the high temperature coolant liquid that comes out in the galvanic pile 9 to the heat conversion of the hydrogen gas mixture before the galvanic pile 9. The temperature of the high-temperature cooling liquid from the electric pile 9 belongs to the control target temperature of the fuel cell thermal management system, and the temperature of the hydrogen mixed gas before the anode of the fuel cell enters the electric pile 9 can be close to the proper temperature of the system by exchanging heat with the high-temperature cooling liquid from the electric pile 9, and meanwhile, the risk that the liquid water generated by excessive condensation of the anode hydrogen mixed gas enters the electric pile 9 is avoided. Meanwhile, the scheme has high energy utilization rate, does not need an external heat source, optimizes the water heating management mode of the electric pile, integrates the whole heat exchange device 7 with the electric pile end plate 8, and has compact structure and high space utilization rate.

Preferably, as shown in fig. 2, the first heat exchange unit 7a and the second heat exchange unit 7b are both composed of a plurality of fins, and this structure increases the convection heat exchange area and improves the heat exchange efficiency. Furthermore, in order to improve the thermal conductivity of the heat exchanger 7, the material of the fins is a metal material having good thermal conductivity, and in order to prevent the hydrogen side of the stack from being contaminated by ion deposition, the fins are preferably made of an aluminum material.

Alternatively, referring to fig. 2 and 5, the fins in this embodiment are all configured in a planar shape, the multiple fins of the first heat exchange unit 7a are arranged in a row from the air inlet 5a to the air outlet 5b of the anode mixed gas chamber 5, the multiple fins are arranged in parallel, and the fin surfaces of the multiple fins are perpendicular to the air flow direction; the plurality of fins of the second heat exchange unit 7b are arranged in a row from the liquid inlet 6a to the liquid outlet 6b of the cooling liquid chamber 6, the plurality of fins are arranged in parallel, and the fin surfaces of the plurality of fins are perpendicular to the liquid flow direction. This kind of design of this embodiment makes heat transfer device 7 compact structure, is convenient for integrate between positive pole gas mixture cavity 5 and coolant liquid cavity 6, and space utilization is high. Of course, in other embodiments, the fins may be formed in a bent shape, the first heat exchange unit 7a and/or the second heat exchange unit 7b may be formed in multiple rows, or may be arranged at an angle instead of being parallel, and the fin surfaces may be formed at an angle instead of being perpendicular to the direction of the gas flow and/or the liquid flow.

Further, as shown in fig. 5, the plurality of fins of the first heat exchange unit 7a are arranged in an inclined upward manner from the air inlet 5a side to the air outlet 5b side of the anode mixed gas chamber 5, and due to the wedge-shaped structural design, the gas flow can be uniformly distributed when the hydrogen mixed gas enters, so that the flow loss is reduced.

Optionally, heat exchanging device 7 further comprises a heat exchanging plate 7c, and both first heat exchanging unit 7a and second heat exchanging unit 7b are in contact with heat exchanging plate 7 c. Specifically, in this embodiment, the heat exchange plate 7c is also made of a metal material, preferably an aluminum material, the first heat exchange unit 7a and the second heat exchange unit 7b are respectively and integrally disposed at two sides of the heat exchange plate 7c, the opening of the anode mixed gas chamber 5 is provided with a first seal groove 5c, the opening of the coolant chamber 6 is provided with a second seal groove 6c, and the first seal groove 5c and the second seal groove 6c are both assembled with the heat exchange plate 7c in a sealing manner. The heat exchange device 7 of the embodiment is integrated with the end plate 8 of the electric pile (refer to fig. 7), and has compact structure and high space utilization rate.

In other embodiments, referring to fig. 8-10, the heat exchanging device 7 may be integrally disposed with the anode mixed gas chamber 5, the material of the anode mixed gas chamber 5 is plastic, the anode mixed gas chamber 5 and the heat exchanging plate 7c of the heat exchanging device 7 form an integrated module through a plastic-clad aluminum process, and then the integrated module is further hermetically assembled with the cooling liquid chamber 6 through a sealing ring.

Further, as shown in fig. 3 to 7, the air inlet 5a of the anode mixture chamber 5 is disposed above one side, the air outlet 5b is disposed below the opposite side of the air inlet 5a, the liquid inlet 6a of the cooling liquid chamber 6 is disposed above one side, and the liquid outlet 6b is disposed below the opposite side of the liquid inlet 6 a. Because of the density of hydrogen gas mixture and the density of coolant liquid all are greater than the density of air, consequently, hydrogen gas mixture and coolant liquid can flow from top to bottom, and air inlet 5a and inlet 6a set up at last, and gas outlet 5b and liquid outlet 6b set up down, follow the flow direction of air current and liquid stream, can improve heat exchange efficiency.

The present embodiment provides a temperature control method of a fuel cell system as follows:

high-temperature cooling liquid coming out of the galvanic pile 9 enters the second heat exchange unit 7b through the second outlet 8d, and flows out of the liquid outlet 6b of the cooling liquid chamber 6 and flows back to the galvanic pile 9 from the second inlet 8c after the second heat exchange unit 7b exchanges heat with the hydrogen mixed gas in the first heat exchange unit 7a to reduce the temperature. The mixture from the electric pile 9 enters a gas-liquid separator 10 through a first outlet 8b, after gas-liquid separation, the gaseous mixture is pumped out by the ejector 4, and forms hydrogen mixed gas together with fresh hydrogen pumped out by the ejector 4 from the hydrogen storage device 1, the hydrogen mixed gas enters a first heat exchange unit 7a from an air inlet 5a of the anode mixed gas chamber 5, and the hydrogen mixed gas enters the electric pile 9 from a first inlet 8a after heat exchange and temperature rise of cooling liquid in the first heat exchange unit 7a and a second heat exchange unit 7 b. And liquid such as liquid water separated by the gas-liquid separator 10 is discharged from the tail discharge valve 11.

The temperature control method can realize that the temperature of the hydrogen mixed gas before the anode of the fuel cell enters the galvanic pile 9 is close to the proper temperature of the system, and simultaneously avoid the risk that the anode hydrogen mixed gas is excessively condensed to generate liquid water to enter the galvanic pile 9. Meanwhile, the scheme has high energy utilization rate, does not need an external heat source, and optimizes the water heating management mode of the electric pile.

It should be noted that the foregoing is only a preferred embodiment of the present invention and the technical principles applied. It will be understood by those skilled in the art that the present invention is not limited to the particular embodiments described herein, but is capable of various obvious changes, rearrangements and substitutions as will now become apparent to those skilled in the art without departing from the scope of the invention. Therefore, although the present invention has been described in greater detail with reference to the above embodiments, the present invention is not limited to the above embodiments, and may include other equivalent embodiments without departing from the scope of the present invention.

Claims (10)

1. The utility model provides a heat transfer device for fuel cell system, fuel cell system includes galvanic pile (9), positive pole gas mixture cavity (5) and coolant liquid cavity (6), its characterized in that, heat transfer device (7) include first heat transfer unit (7 a) and second heat transfer unit (7 b), first heat transfer unit (7 a) are located in positive pole gas mixture cavity (5), second heat transfer unit (7 b) are located in coolant liquid cavity (6), second heat transfer unit (7 b) can with the high temperature coolant liquid that comes out in galvanic pile (9) carries out the heat transfer to reach first heat transfer unit (7 a), and then first heat transfer unit (7 a) can heat the hydrogen gas mixture that gets into before galvanic pile (9).

2. A heat exchange device according to claim 1, characterized in that the first heat exchange unit (7 a) and the second heat exchange unit (7 b) are each composed of a plurality of fins.

3. A heat exchange device according to claim 2, characterized in that the heat exchange device (7) comprises at least one of the following:

the first mode is as follows: the fins of the first heat exchange unit (7 a) are arranged in a row from the air inlet (5 a) to the air outlet (5 b) of the anode mixed gas chamber (5);

the second mode is as follows: the fins of the second heat exchange unit (7 b) are arranged in a row from the liquid inlet (6 a) to the liquid outlet (6 b) of the cooling liquid cavity (6).

4. A heat exchange device according to claim 3, characterized in that in the first mode, a plurality of fins of the first heat exchange unit (7 a) are arranged parallel to each other;

and/or, in the second mode, the plurality of fins of the second heat exchange unit (7 b) are arranged in parallel with each other.

5. The heat exchange device according to claim 4, wherein the fin faces of the plurality of fins of the first heat exchange unit (7 a) are perpendicular to the direction of the gas flow;

and/or the fin surfaces of the plurality of fins of the second heat exchange unit (7 b) are perpendicular to the liquid flow direction.

6. A heat exchange device according to claim 2, wherein the plurality of fins of the first heat exchange unit (7 a) are arranged diagonally upward from the gas inlet (5 a) side to the gas outlet (5 b) side of the anode mixture chamber (5).

7. A heat exchange device according to claim 2, wherein the heat exchange device (7) further comprises heat exchange plates (7 c), and the first heat exchange unit (7 a) and the second heat exchange unit (7 b) are both in contact with the heat exchange plates (7 c).

8. A fuel cell system comprising the heat exchange device according to any one of claims 1 to 7.

9. A fuel cell system according to claim 8, wherein the inlet port (5 a) of the anode mixture chamber (5) is disposed above one side and the outlet port (5 b) is disposed below the opposite side of the inlet port (5 a);

and/or the liquid inlet (6 a) of the cooling liquid cavity (6) is arranged above one side, and the liquid outlet (6 b) is arranged below the opposite side of the liquid inlet (6 a).

10. The fuel cell system according to claim 8, wherein a first outlet (8B), a second outlet (8 d), a first inlet (8 a) and a second inlet (8 c) are arranged on the stack end plate (8), the fuel cell system further comprises a gas-liquid separator (10), a hydrogen storage device (1), an ejector (4) and a tail discharge valve (11), the first outlet (8B) is connected with an inlet of the gas-liquid separator (10), an inlet A of the ejector (4) is connected with an outlet of the gas-liquid separator (10) through a first pipeline, an inlet B of the ejector (4) is connected with an outlet of the hydrogen storage device (1), an outlet of the ejector (4) is connected with an air inlet (5 a) of the anode mixed gas chamber (5), and an inlet of the tail discharge valve (11) is connected with the first pipeline, the gas outlet (5 b) of the anode mixed gas cavity (5) is connected with the first inlet (8 a), the second outlet (8 d) is connected with the liquid inlet (6 a) of the cooling liquid cavity (6), and the liquid outlet (6 b) of the cooling liquid cavity (6) is connected with the second inlet (8 c).

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