CN216812314U - Ejector with multi-mode spray head and fuel cell system - Google Patents

Abstract

The utility model provides an ejector with a multi-mode nozzle and a fuel cell system, wherein the ejector is provided with an ejector fluid inlet, a return fluid inlet, a mixed fluid outlet and the multi-mode nozzle arranged on the ejector fluid inlet, the multi-mode nozzle is provided with a main injection channel and at least one auxiliary injection channel, and a one-way valve is arranged in the auxiliary injection channel and is opened when the pressure is greater than a preset threshold value. By the fuel cell ejector with the multi-mode nozzle, a fuel cell system can better match the required reflux ratio under different working conditions.

Description

Ejector with multi-mode spray head and fuel cell system

Technical Field

The utility model belongs to the technical field of fuel cells, and particularly relates to an ejector with a multi-mode nozzle and a fuel cell system.

Background

During operation of a fuel cell stack, a portion of the anode gas (fuel gas) entering the stack undergoes an electrochemical reaction, while the remaining anode gas is exhausted from the stack along with the reaction products. In order to improve the utilization rate of the anode gas, the fuel cell system is provided with a circulating pipeline, and the discharged anode gas is mixed with newly supplied anode gas and enters the electric pile again to participate in reaction.

The ejector is a device for ejecting another low-speed fluid by using high-speed fluid, and can use newly-supplied anode gas as high-speed fluid to introduce the anode gas discharged by the fuel cell stack into the ejector to be mixed with the newly-supplied anode gas and then enter the fuel cell stack again. The ejector has no moving parts, does not need to consume external energy, and has simple structure, small volume and low cost, so the ejector is generally applied to a fuel cell system.

However, conventional ejectors often have difficulty providing the desired reflux ratio: the fuel cell stack usually needs a larger anode gas reflux ratio under low current, but the flow of fresh anode gas entering the ejector under low current is smaller, so that a larger reflux amount is difficult to generate; on the other hand, the fuel cell stack consumes a large amount of anode gas under high current, the required reflux ratio is reduced, but the flow of fresh anode gas entering the ejector is large at the moment, and a larger reflux amount is easily generated. In addition, because the nozzle sectional area of the ejector is very small, in order to provide enough anode gas under the high-current working condition, the pressure at the front end of the ejector needs to be very high, which causes that the pressure-bearing performance of upstream parts of the ejector is more severe.

In order to realize adjustable reflux quantity, a feasible idea is to enable the sectional area of a nozzle of the ejector to be adjustable. Under the thought, CN112145485A tries to provide an ejector with an adjustable nozzle sectional area, and the specific scheme is that a series of elements such as a gear ring and an adjusting flap are arranged at the nozzle outlet of the ejector, and the nozzle sectional area is changed by controlling the opening of the adjusting flap. However, the design scheme has a complex structure, and the size of the ejector nozzle is small, so that the design scheme has high cost and poor stability, and is difficult to apply in engineering practice.

SUMMERY OF THE UTILITY MODEL

The utility model provides an ejector with a multi-mode nozzle and a fuel cell system, aiming at the problems in the prior art.

In a first aspect of the utility model, there is provided an eductor with a multi-mode spray head, the eductor having an eductor fluid inlet, a return fluid inlet and a mixed fluid outlet; the multi-mode spray head is arranged on the injection fluid inlet and is provided with a main injection passage and at least one auxiliary injection passage; a check valve is disposed in the secondary injection passage and configured to open when the pressure is greater than a preset threshold. The injector can be in a state that the main injection passage and the auxiliary injection passage are simultaneously opened after the pressure reaches the preset threshold value by arranging the at least one auxiliary injection passage provided with the one-way valve on the nozzle, so that the injection sectional area is substantially increased, and the adjustable backflow amount is realized.

Specifically, the check valve is a mechanical check valve or an electromagnetic check valve.

Specifically, the main injection passage and the at least one auxiliary injection passage are arranged in an inner hole and an outer ring manner or in a parallel manner.

Specifically, the main injection passage and the at least one sub-injection passage have low-mach-number injection ports or high-mach-number injection ports.

In a second aspect of the present invention, there is provided a fuel cell system having a fuel cell stack, an anode gas supply line, and an anode gas circulation line; a main path electromagnetic valve and an ejector are arranged on the anode gas supply pipeline; the ejector is the ejector with the multi-mode spray head; the main path electromagnetic valve is communicated with the multi-mode spray head; and a gas-water separator is arranged on the anode gas circulation pipeline, and a gas outlet of the gas-water separator is connected with a reflux fluid inlet of the ejector with the multi-mode spray head.

Specifically, the anode gas supply pipeline is further provided with an anode gas supply bypass connected with the main path electromagnetic valve and the ejector in parallel, and the anode gas supply bypass is provided with a bypass electromagnetic valve.

Specifically, the main path solenoid valve, the ejector, the bypass solenoid valve and the anode gas supply bypass are arranged to be of a modular integrated structure.

The control process of the fuel cell system comprises the step of monitoring the output current and the anode gas reflux ratio of the fuel cell system, and when the anode gas reflux ratio is larger than the theoretical reflux ratio corresponding to the output current, the bypass electromagnetic valve is opened. Specifically, the control method may control the opening degree of the bypass solenoid valve according to a difference between the anode gas reflux amount and a theoretical reflux ratio corresponding to the output current.

The ejector with the multi-mode nozzle and the fuel cell system provided by the utility model can provide the required reflux ratio according to the actual working condition of the fuel cell, so that the fuel cell is closer to an ideal running state, and the efficiency of the fuel cell is favorably improved. When the fuel cell is in a high-current operation state, on one hand, the injection sectional area is increased by starting the auxiliary injection channel, and on the other hand, the pressure performance requirement on the front-end part of the ejector is also reduced. Meanwhile, by arranging the anode gas supply bypass, a part of anode gas can directly enter the galvanic pile without passing through the ejector when the demand of the anode gas is large, and the reflux ratio of the system is reduced.

Drawings

The foregoing and other objects, features and advantages of the disclosure will be apparent from the following more particular descriptions of exemplary embodiments of the disclosure as illustrated in the accompanying drawings wherein like reference numbers generally represent like parts throughout the exemplary embodiments of the disclosure.

FIG. 1 illustrates a multi-mode showerhead in an embodiment;

FIG. 2 is a partial schematic view of another multi-mode showerhead in an embodiment;

FIG. 3 shows a schematic view of a one-way valve in an embodiment;

FIG. 4 shows a pressure-flow curve of the check valve of FIG. 3;

FIG. 5 shows another one-way valve schematic in an embodiment;

FIG. 6 shows a pressure-flow curve for the check valve of FIG. 5;

fig. 7 shows a fuel cell system in an embodiment;

fig. 8 shows a partial schematic view of a fuel cell system in an embodiment.

Reference numerals: 1-a multi-mode spray head; 11-main injection channel; 12-a secondary jet channel; 13-a one-way valve; 131-a valve core; 132-a valve housing; 2-fuel cell stack; 3-anode gas supply line; 31-anode gas supply bypass; 32-a bypass solenoid valve; 4-anode gas circulation line; 5-main path electromagnetic valve; 6-an ejector; 7-a gas-water separator; 8-safety valve; 9-tail discharge valve.

Detailed Description

Embodiments of the present disclosure will be described in more detail below with reference to the accompanying drawings. While embodiments of the present disclosure are shown in the drawings, it should be understood that the present disclosure may be embodied in various forms and should not be limited by the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the disclosure to those skilled in the art.

The term "including" and variations thereof as used herein is intended to be open-ended, i.e., "including but not limited to". Unless specifically stated otherwise, the term "or" means "and/or". The term "based on" means "based at least in part on". The terms "connected" and "communicating" mean connected or communicating either directly or indirectly through other components. The terms "first," "second," and the like may refer to different or the same items, but do not directly indicate a difference in order of precedence or degree of importance. Other explicit and implicit definitions are also possible below.

As shown in fig. 1, the present invention provides a multi-mode spray head 1, and as described above, the ejector is a device for ejecting another low-speed fluid by using a high-speed fluid, and it is required to form the high-speed fluid by using the spray head and generate a low pressure, and to introduce and mix the low-speed fluid with the high-speed fluid by using the low pressure, and finally to eject the mixed fluid from the mixed fluid outlet of the ejector. The multi-mode spray head 1 has a main injection passage 11 and at least one secondary injection passage 12, the secondary injection passage 12 having a check valve 13 disposed therein, the check valve 13 being configured to open when a pressure is greater than a preset threshold. That is, only the main injection passage 11 is operated when the pressure is lower than the preset threshold, and the main injection passage 11 and the sub-injection passage 12 are simultaneously activated when the pressure is higher than the preset threshold.

The specific arrangement of the main injection passage 11 and the auxiliary injection passage 12 is not particularly limited, and for example, an inner-hole outer-ring type may be used in which the main injection passage 11 is provided at the center of the multi-mode nozzle 1, and the auxiliary injection passage 12 is provided in a ring shape around the periphery of the main injection passage 11; or a side-by-side arrangement as shown in figure 2 may be used. As for the specific type of the injection passage, the low mach number type injection ports may be provided, and the high mach number injection ports may be provided as shown in fig. 2.

The check valve 13 may be a mechanical check valve, or may be an electromagnetic check valve capable of actively controlling the lift. Further, by designing the valve core 131 and the valve sleeve 132 of the check valve 13, different pressure-flow curves can be obtained. As shown by a comparison of fig. 3-6, by using a streamlined valve spool, a lower flow rate can be achieved at the same pressure level at the check valve 13, and a lower rate of flow increase at the beginning of the opening of the check valve 13.

Fig. 7 shows a fuel cell system having a fuel cell stack 2, an anode gas supply line 3, and an anode gas circulation line 4 in an embodiment of the utility model; the anode gas supply pipeline 3 is provided with a main path electromagnetic valve 5 and an ejector 6; the multi-mode spray head 1 is installed on an injection fluid inlet of the injector 6; the main path electromagnetic valve 5 is communicated with the multi-mode spray head 1; and a gas-water separator 7 is arranged on the anode gas circulation pipeline 4, and a gas outlet of the gas-water separator 7 is connected with a reflux fluid inlet of the ejector 6. As shown in fig. 3, the fuel cell system further includes a safety valve 8, a tail valve 9, and other components. Other components not shown in the drawings may be provided as is generally understood in the art, and the present invention is not particularly described herein.

Specifically, the anode gas supply line 3 further has an anode gas supply bypass 31 connected in parallel to the main path solenoid valve 5 and the ejector 6, and the anode gas supply bypass 31 is provided with a bypass solenoid valve 32. By arranging the anode gas supply bypass 31 in parallel, when the demand of the anode gas is large, a part of the anode gas can directly enter the fuel cell stack 2 without passing through the ejector 6, so that the anode gas entering the ejector 6 through the multi-mode nozzle 1 is further reduced, the reflux amount is correspondingly reduced, and the requirement of the fuel cell system on the reflux ratio under the high-current working condition is met.

In an embodiment of the present invention, as shown in fig. 8, the main solenoid valve 5, the ejector 6, the bypass solenoid valve 32, and the anode gas supply bypass 31 are arranged in a modular integrated structure to form an integrated anode gas supply unit. By modularizing the relevant components on the anode gas supply line 3, the fuel cell system can be made more convenient to manufacture and to maintain afterwards.

The above fuel cell system includes, in the control process, a step of monitoring the output current of the fuel cell system and the anode gas reflux ratio during the operation of the fuel cell system, and when the anode gas reflux ratio is larger than the theoretical reflux ratio corresponding to the output current, that is, when the anode gas reflux amount is excessively large, the bypass solenoid valve 32 is opened, so that a part of the anode gas directly enters the fuel cell stack 2 through the anode gas supply bypass 31. Specifically, the opening degree of the bypass solenoid valve 32 may be determined according to a difference between a theoretical reflux ratio of the anode gas reflux amount and the output current.

Having described embodiments of the present disclosure, the foregoing description is intended to be exemplary, not exhaustive, and not limited to the disclosed embodiments. Many modifications and variations will be apparent to those of ordinary skill in the art without departing from the scope and spirit of the described embodiments. The terminology used herein is chosen to best explain the principles of the embodiments, the practical application, or improvements made to the prior art, or to enable others of ordinary skill in the art to understand the embodiments disclosed herein.

Claims (6)

1. An ejector with a multi-mode nozzle is characterized in that the ejector is provided with an ejector fluid inlet, a return fluid inlet and a mixed fluid outlet; the multi-mode spray head is arranged on the injection fluid inlet and is provided with a main injection passage and at least one auxiliary injection passage; a check valve is disposed in the secondary injection passage and configured to open when the pressure is greater than a preset threshold.

2. The injector as claimed in claim 1, wherein the check valve is a mechanical check valve or an electromagnetic check valve.

3. The injector as claimed in claim 1, wherein the main injection passage and the at least one secondary injection passage are arranged in an inside-outside loop manner or in a side-by-side manner.

4. The ejector having a multi-mode nozzle as claimed in claim 1, wherein the main injection passage and the at least one sub-injection passage have low mach number injection ports or high mach number injection ports.

5. A fuel cell system characterized by having a fuel cell stack, an anode gas supply line, and an anode gas circulation line;

a main path electromagnetic valve and an ejector are arranged on the anode gas supply pipeline; the ejector is selected from the group consisting of ejectors having multi-mode jets of any of claims 1-4; the main path electromagnetic valve is communicated with the multi-mode spray head;

a gas-water separator is arranged on the anode gas circulation pipeline, and a gas outlet of the gas-water separator is connected with a backflow fluid inlet of the ejector with the multi-mode spray head;

the anode gas supply pipeline is also provided with an anode gas supply bypass which is connected with the main path electromagnetic valve and the ejector in parallel, and the anode gas supply bypass is provided with a bypass electromagnetic valve.

6. The fuel cell system according to claim 5, wherein the main path solenoid valve, the ejector, the bypass solenoid valve, and the anode gas supply bypass are provided in a modular integrated structure.

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