阅读说明：本技术 适用于氢燃料电池系统的多喷嘴引射器及氢燃料电池系统 (Multi-nozzle ejector suitable for hydrogen fuel cell system and hydrogen fuel cell system ) 是由 王雷 宋亚杰 杜志强 于 2021-03-08 设计创作，主要内容包括：本发明属于引射器和燃料电池领域,提供了一种适用于氢燃料电池系统的多喷嘴引射器及氢燃料电池系统。该多喷嘴引射器包括一次流管、多喷嘴结构、吸入室、二次流入口、混合室和扩散室；一次流管、多喷嘴结构、混合室和扩散室沿轴线依次连通；所述吸入室和二次流入口分别设置在多喷嘴结构两侧,且均与混合室连通；一次流管的数量与多喷嘴结构中的喷嘴数量相等且一一对应连通；一次流管用于接收减压后的高压氢气,在多喷嘴结构出口形成低压区域,以吸入二次流入口连通的燃料电池阳极出口处的气体,再经混合室混合之后送入燃料电池；其中,多喷嘴结构中各个喷嘴的工作状态由燃料电池的输出功率大小决定。(The invention belongs to the field of ejectors and fuel cells, and provides a multi-nozzle ejector suitable for a hydrogen fuel cell system and the hydrogen fuel cell system. The multi-nozzle ejector comprises a primary flow pipe, a multi-nozzle structure, a suction chamber, a secondary flow inlet, a mixing chamber and a diffusion chamber; the primary flow pipe, the multi-nozzle structure, the mixing chamber and the diffusion chamber are sequentially communicated along the axis; the suction chamber and the secondary inflow port are respectively arranged at two sides of the multi-nozzle structure and are communicated with the mixing chamber; the number of the primary flow pipes is equal to that of the nozzles in the multi-nozzle structure and the primary flow pipes are communicated in a one-to-one correspondence manner; the primary flow pipe is used for receiving the decompressed high-pressure hydrogen, forming a low-pressure area at the outlet of the multi-nozzle structure, sucking the gas at the anode outlet of the fuel cell communicated with the secondary flow inlet, mixing the gas in the mixing chamber and then sending the mixed gas into the fuel cell; wherein, the working state of each nozzle in the multi-nozzle structure is determined by the output power of the fuel cell.)

1. A multi-nozzle ejector suitable for a hydrogen fuel cell system is characterized by comprising a primary flow pipe, a multi-nozzle structure, an intake chamber, a secondary flow inlet, a mixing chamber and a diffusion chamber;

the primary flow pipe, the multi-nozzle structure, the mixing chamber and the diffusion chamber are sequentially communicated along the axis; the suction chamber and the secondary inflow port are respectively arranged at two sides of the multi-nozzle structure and are communicated with the mixing chamber; the number of the primary flow pipes is equal to that of the nozzles in the multi-nozzle structure and the primary flow pipes are communicated with the nozzles in a one-to-one correspondence manner;

the primary flow pipe is used for receiving the decompressed high-pressure hydrogen, forming a low-pressure area at the outlet of the multi-nozzle structure, sucking the gas at the anode outlet of the fuel cell communicated with the secondary inlet, mixing the gas in the mixing chamber and then sending the mixed gas into the fuel cell; wherein, the working state of each nozzle in the multi-nozzle structure is determined by the output power of the fuel cell.

2. The multi-nozzle eductor for a hydrogen fuel cell system of claim 1 wherein the multi-nozzle structure comprises a cylindrical section and a tapered section, the portion of the tapered section being conical; the part of the cylindrical section is cylindrical.

3. The multi-nozzle eductor for a hydrogen fuel cell system of claim 1 wherein said multi-nozzle structure is a coaxial dual nozzle, a focused three nozzle or a focused four nozzle.

4. The multi-nozzle eductor for a hydrogen fuel cell system of claim 3 wherein the coaxial dual nozzles comprise a first nozzle and a second nozzle, the flow passages of the first nozzle and the second nozzle opening along the axis of the eductor, wherein the throat area of the first nozzle is less than the throat area of the second nozzle.

5. The multi-nozzle eductor for a hydrogen fuel cell system according to claim 4 wherein the outlet of the first nozzle is circular and the outlet of the second nozzle is annular.

6. The multi-nozzle eductor for a hydrogen fuel cell system of claim 3 wherein the throat diameter of the first nozzle is 1.12mm and the inlet diameter is 3mm, the throat diameter of the second nozzle is 2.2mm and the outer diameter is 2.8mm, the inner diameter of the inlet is 5mm and the outer diameter is 8mm, and the diameter of the equal area mixing section of the eductor mixing chamber is 5.6 mm.

7. The multi-nozzle eductor for a hydrogen fuel cell system according to claim 1 wherein each nozzle in the multi-nozzle configuration is connected to a corresponding hydrogen supply conduit by a respective primary flow tube.

8. The multi-nozzle eductor for a hydrogen fuel cell system as defined in claim 7 wherein a solenoid valve is connected to each hydrogen supply conduit, said solenoid valve being controlled by the controller to be turned on and off in response to the output power level of the fuel cell.

9. The multi-nozzle eductor for a hydrogen fuel cell system of claim 1 wherein the mixing chamber comprises two mixing sections, an isobaric mixing section and an equal area mixing section.

10. A hydrogen fuel cell system comprising a multi-nozzle ejector suitable for use in a hydrogen fuel cell system according to any one of claims 1 to 9.

Technical Field

The invention belongs to the field of ejectors and fuel cells, and particularly relates to a multi-nozzle ejector suitable for a hydrogen fuel cell system and the hydrogen fuel cell system.

Background

The statements in this section merely provide background information related to the present disclosure and may not necessarily constitute prior art.

The proton exchange membrane fuel cell is an energy conversion device for converting chemical energy of hydrogen into electric energy, and becomes a green substitute for replacing an internal combustion engine as a power source of an automobile due to the advantages of high efficiency, quick start, high power density, small running sound and the like. The hydrogen supply subsystem is one of the important subsystems in the fuel cell, and usually uses a mechanical pump to recycle hydrogen gas, so as to improve the hydrogen utilization rate of the fuel cell. The ejector has the advantages of low cost, good sealing performance, low noise, no parasitic power consumption in the use process and the like, and has the development trend of replacing a mechanical pump.

The ejector is a widely-used fluid machine, and energy conversion is realized by using jet flow of working fluid. In the practical application of the fuel cell, the performance of the conventional ejector is mainly determined by the output power of the fuel cell. The injection performance evaluation index of the injector is the recirculation rate, namely the ratio of the mass flow of the secondary flow to the mass flow of the primary flow. In fuel cell systems, hydrogen excess ratios greater than 1.5 are typically required, corresponding to ejector recirculation rates greater than 0.5 being designed. Generally, a fuel cell automobile is subjected to running conditions such as high speed, low speed, stagnation and the like, so that the ejector is required to work efficiently in a wider power range; after the traditional ejector deviates from the designed working point, the performance of the traditional ejector can be greatly attenuated, which is a main reason for preventing the ejector from being widely applied to a hydrogen fuel cell system. At present, a variable nozzle ejector is provided, the working condition range of the ejector is changed by adjusting the size of a nozzle through a controllable spray needle, and the problem that the working range of the traditional ejector is narrow can be solved. However, the inventor found that the position of the needle needs to be controlled with high precision and needs a stable working environment, which makes the driving device of the ejector extremely complex and is not suitable for the dynamic operation of the vehicle fuel cell system.

Disclosure of Invention

In order to solve the technical problems in the background art, a first aspect of the present invention provides a multi-nozzle ejector suitable for a hydrogen fuel cell system, which can automatically switch and adapt to different nozzles according to the output power of a fuel cell, and can enable the ejector to work under a large range of output power of the fuel cell and have good performance.

In order to achieve the purpose, the invention adopts the following technical scheme:

a multi-nozzle ejector suitable for a hydrogen fuel cell system comprises a primary flow pipe, a multi-nozzle structure, an intake chamber, a secondary flow inlet, a mixing chamber and a diffusion chamber;

the primary flow pipe, the multi-nozzle structure, the mixing chamber and the diffusion chamber are sequentially communicated along the axis; the suction chamber and the secondary inflow port are respectively arranged at two sides of the multi-nozzle structure and are communicated with the mixing chamber; the number of the primary flow pipes is equal to that of the nozzles in the multi-nozzle structure and the primary flow pipes are communicated with the nozzles in a one-to-one correspondence manner;

the primary flow pipe is used for receiving the decompressed high-pressure hydrogen, forming a low-pressure area at the outlet of the multi-nozzle structure, sucking the gas at the anode outlet of the fuel cell communicated with the secondary inlet, mixing the gas in the mixing chamber and then sending the mixed gas into the fuel cell; wherein, the working state of each nozzle in the multi-nozzle structure is determined by the output power of the fuel cell.

As an embodiment, the multi-nozzle structure comprises a cylindrical section and a tapered section, and the part of the tapered section is conical; the part of the cylindrical section is cylindrical.

As an embodiment, the multi-nozzle structure is a coaxial dual nozzle, a focusing three nozzle, or a focusing four nozzle.

In one embodiment, the coaxial dual nozzle includes a first nozzle and a second nozzle, the flow passages of the first nozzle and the second nozzle open along the axis of the eductor, wherein the throat area of the first nozzle is less than the throat area of the second nozzle.

In one embodiment, the outlet of the first nozzle is circular and the outlet of the second nozzle is annular.

As an embodiment, the throat diameter of the first nozzle is 1.12mm, the inlet diameter is 3mm, the throat diameter of the second nozzle is 2.2mm, the outer diameter is 2.8mm, the inner diameter of the inlet is 5mm, the outer diameter is 8mm, and the vertical diameter of the mixing section of the mixing chamber area of the ejector is 5.6 mm.

The area of the equal-area mixing section of the ejector mixing chamber is matched with the sum of the areas of the plurality of nozzles.

As an embodiment, each nozzle in the multi-nozzle structure is connected to a corresponding hydrogen supply pipe through a corresponding primary flow pipe.

In one embodiment, each hydrogen supply pipeline is connected with an electromagnetic valve, and the electromagnetic valve is controlled to be switched on and off by a controller according to the output power of the fuel cell.

In one embodiment, the mixing chamber includes two mixing sections, an isobaric mixing section and an equal area mixing section.

A second aspect of the invention provides a hydrogen fuel cell system comprising a multi-nozzle eductor as described above suitable for use in a hydrogen fuel cell system.

The invention has the beneficial effects that:

(1) the invention improves the nozzle of the existing ejector, divides the original nozzle into a plurality of nozzles, takes a multi-nozzle structure as a coaxial double nozzle as an example, when the output power of a fuel cell is small, high-pressure gas only passes through a first nozzle and does not pass through a second nozzle, so that the ejector can still obtain higher gas potential energy, the defect of poor performance of the ejector caused by insufficient main flow energy under low primary flow mass flow is solved, the high-pressure gas can enter the second nozzle and does not pass through the first nozzle under the medium and high output power, the high-pressure gas can pass through the two nozzles and the two nozzles work together under the maximum output power, so that the multi-nozzle ejector can work under the large-range output power of the fuel cell, the working range of the traditional ejector in a fuel cell system is widened, and the defect that the traditional ejector cannot meet the variable operating condition of the fuel cell in the driving process is improved, in addition, compared with an automatic adjusting nozzle ejector, the driving mechanism and the algorithm of a control motor are reduced, and the hydrogen supply system composed of the multi-nozzle ejector is simpler in structure.

(2) The multi-nozzle ejector is safe and reliable, simple in structure and low in cost, can be automatically switched to be suitable for different nozzles according to the output power of the fuel cell, can work under the large-range output power of the fuel cell, and has good performance.

Advantages of additional aspects of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention.

Drawings

The accompanying drawings, which are incorporated in and constitute a part of this specification, are included to provide a further understanding of the invention, and are incorporated in and constitute a part of this specification, illustrate exemplary embodiments of the invention and together with the description serve to explain the invention and not to limit the invention.

FIG. 1 is a schematic diagram of a conventional ejector;

FIG. 2 is a schematic structural view of a coaxial dual nozzle eductor in accordance with an embodiment of the present invention;

FIG. 3(a) is a focusing dual nozzle structure according to an embodiment of the present invention;

FIG. 3(b) is a focusing three-nozzle structure provided by an embodiment of the present invention;

FIG. 3(c) is a focusing four-nozzle structure provided by an embodiment of the present invention;

fig. 4 is a block diagram of an application of the multi-nozzle ejector of the embodiment of the present invention to a fuel cell system.

The device comprises a primary flow pipe 1, a suction chamber 2, a traditional single nozzle 3, a secondary inflow port 4, an isobaric mixing section 5, an equal-area mixing section 6, a diffusion chamber 7 and a multi-nozzle structure 8.

Detailed Description

The invention is further described with reference to the following figures and examples.

It is to be understood that the following detailed description is exemplary and is intended to provide further explanation of the invention as claimed. Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs.

It is noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of exemplary embodiments according to the invention. As used herein, the singular forms "a", "an" and "the" are intended to include the plural forms as well, and it should be understood that when the terms "comprises" and/or "comprising" are used in this specification, they specify the presence of stated features, steps, operations, devices, components, and/or combinations thereof, unless the context clearly indicates otherwise.

In the present invention, terms such as "upper", "lower", "left", "right", "front", "rear", "vertical", "horizontal", "side", "bottom", and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings, and are only terms of relationships determined for convenience of describing structural relationships of the parts or elements of the present invention, and are not intended to refer to any parts or elements of the present invention, and are not to be construed as limiting the present invention.

In the present invention, terms such as "fixedly connected", "connected", and the like are to be understood in a broad sense, and mean either a fixed connection or an integrally connected or detachable connection; may be directly connected or indirectly connected through an intermediate. The specific meanings of the above terms in the present invention can be determined according to specific situations by persons skilled in the relevant scientific or technical field, and are not to be construed as limiting the present invention.

As shown in fig. 1, the currently available commercial ejector includes a primary flow pipe 1, a nozzle 3, a suction chamber 2, a secondary flow pipe 4, a mixing chamber and a diffusion chamber 7; wherein the mixing chamber comprises two mixing sections, namely an isobaric mixing section 5 and an equal-area mixing section 6. A nozzle 3 is connected to the outlet of the primary flow tube 1, said nozzle 3 traversing the suction chamber 2 into the mixing chamber; the diffusion chamber 7 is connected to the outlet of the mixing chamber; the secondary flow pipe 4 is arranged below the mixing chamber and is communicated into the mixing chamber.

The ejector in the hydrogen supply circulation system of the fuel cell works according to the following principle: the high-pressure hydrogen gas passes through a pressure reducing valve to obtain proper hydrogen supply pressure, a low-pressure area is formed at the outlet of a nozzle through a primary flow nozzle, the low-pressure area can suck the hydrogen gas, water vapor and nitrogen gas at the outlet of the anode of the fuel cell, then the two gases exchange energy in a remixing chamber, and finally the mixed gas is sent to the fuel cell.

As shown in fig. 2, the multi-nozzle ejector suitable for the hydrogen fuel cell system of the present embodiment includes a primary flow pipe 1, a multi-nozzle structure 8, an intake chamber 2, a secondary flow inlet 4, a mixing chamber, and a diffusion chamber 7.

Wherein the mixing chamber comprises two mixing sections, respectively an isobaric mixing section 5 and an equal-area mixing section 6.

The primary flow pipe 1, the multi-nozzle structure 8, the mixing chamber and the diffusion chamber 7 are sequentially communicated along the axis; the suction chamber 2 and the secondary inflow port 4 are respectively arranged at two sides of the multi-nozzle structure 8 and are communicated with the mixing chamber; the number of the primary flow pipes 1 is equal to that of the nozzles in the multi-nozzle structure 8, and the primary flow pipes are communicated with the nozzles in a one-to-one correspondence manner;

the primary flow pipe 1 is used for receiving the decompressed high-pressure hydrogen, forming a low-pressure area at the outlet of the multi-nozzle structure 8 so as to suck the gas at the anode outlet of the fuel cell communicated with the secondary flow inlet 4, mixing the gas in the mixing chamber and then sending the gas into the fuel cell; the operating state of each nozzle in the multi-nozzle structure 8 is determined by the output power of the fuel cell.

In a specific implementation, the multi-nozzle structure 8 comprises a cylindrical section and a tapered section, the portion at the tapered section being conical; the part of the cylindrical section is cylindrical.

The multi-nozzle structure 8 of the embodiment is determined according to the requirement of the vehicle fuel cell, and under the condition that the working range required by the vehicle fuel cell is widened, the number of the nozzles can be increased, so that the applicable power of the ejector is widened in a wider range. See fig. 3(a) -3 (c): focusing double nozzles, focusing three nozzles, and focusing four nozzles.

Taking the multi-nozzle structure as a coaxial double-nozzle as an example:

the coaxial double-nozzle comprises a first nozzle and a second nozzle, wherein the flow pore passages of the first nozzle and the second nozzle are formed along the axis of the ejector, and the throat area of the first nozzle is smaller than that of the second nozzle.

Wherein, the outlet of the first nozzle is circular, and the outlet of the second nozzle is annular.

The diameter of the throat part of the first nozzle is 1.12mm, the diameter of the inlet is 3mm, the inner diameter of the throat part of the second nozzle is 2.2mm, the outer diameter of the throat part of the second nozzle is 2.8mm, the inner diameter of the inlet is 5mm, the outer diameter of the inlet is 8mm, and the diameter of the equal-area mixing section of the mixing chamber of the ejector is 5.6 mm. The area of the equal-area mixing section of the ejector mixing chamber is matched with the sum of the areas of the plurality of nozzles.

In this embodiment, each nozzle in the multi-nozzle structure is connected to a corresponding hydrogen supply conduit via a respective primary flow tube.

And each hydrogen supply pipeline is connected with an electromagnetic valve, and the electromagnetic valve is controlled to be switched on and switched off by a controller according to the output power of the fuel cell.

For example: the applicable power range of the multi-nozzle ejector is 18kW-120 kW. In a system of a 120kW fuel cell hydrogen circulation system, the hydrogen supply pressure of an ejector is set within a proper range of 3bar-10bar, the temperature is 20 ℃, the pressure of secondary flow hydrogen is 1.9bar, and the temperature is 70 ℃; the pressure at the exit of the eductor was 2.2bar and the temperature was 65 ℃.

According to the requirement of the output power of the vehicle fuel cell, the ejector can be in different working modes by controlling the electromagnetic valve, when the output power of the fuel cell is less than 35kW, the electromagnetic valve is controlled to use the first nozzle, when the power of the fuel cell is 35kW-80KW, the second nozzle is used, and when the power of the fuel cell is more than 80kW, the two nozzles are used together.

As shown in fig. 4, the specific application structure of the multi-nozzle ejector in the fuel cell system includes a high-pressure hydrogen supply tank, a pressure reducing valve, a steam-water separator, a plurality of electromagnetic valves, an exhaust valve, and a multi-nozzle ejector, wherein a hydrogen supply pipeline of a nozzle of the multi-nozzle ejector is connected to the electromagnetic valve.

The operation of the multi-nozzle ejector suitable for the hydrogen fuel cell system of the embodiment is as follows:

referring to fig. 2 and 4, when the fuel cell vehicle is in a low speed state (i.e. when the output power of the fuel cell is less than the preset power) during the driving process, the first nozzle of the coaxial dual-nozzle ejector is used, the hydrogen supply pipeline of the second nozzle is in a closed state, the high-pressure hydrogen passes through the first nozzle, and expands to form a low-pressure area at the nozzle outlet, the low-pressure area is less than the pressure of the secondary flow hydrogen, the secondary flow hydrogen can be sucked into the suction chamber, the two air flows are mixed in the mixing section, then the speed is reduced when entering the pressure expansion section, the pressure is increased, the hydrogen supply pressure required by the fuel cell stack is reached, and finally the hydrogen supply pressure enters the stack from the ejector outlet. When the speed of the fuel cell automobile is high (namely the power is high) in the running process, the second nozzle of the coaxial double-nozzle ejector can be used, the first nozzle does not work, and the working principle of the first nozzle is the same as that of the first nozzle; the first nozzle and the second nozzle operate together when full fuel cell power operation is required.

When the multi-nozzle structure is a focusing double nozzle, a focusing three nozzle or a focusing four nozzle, the working process of the multi-nozzle ejector suitable for the hydrogen fuel cell system is as follows:

the fuel cell system has the same working principle as the fuel cell system with the coaxial double-nozzle ejector, the output power of the fuel cell determines the working state of each nozzle of the multi-nozzle ejector, and the higher the power is, the more the nozzles are used, the lower the power is, and the fewer the nozzles are used. For example, when the multi-nozzle structure is a focusing four-nozzle structure (four nozzles are the same size), when the running speed of the automobile is low (namely the output power of the fuel cell is less than the preset power), only one nozzle is in the working state, when the automobile runs at the middle-high power, two nozzles or three nozzles work together, and when the automobile needs to run at the full power, four nozzles work together. However, as the number of nozzles in the multi-nozzle structure increases, the power range of a single nozzle is more and more limited due to structural limitation, the difficulty of the manufacturing process increases, and the number of nozzles in the optimal multi-nozzle structure is 2-4.

In other embodiments, there is also provided a hydrogen fuel cell system comprising a multi-nozzle eductor as described above suitable for use in a hydrogen fuel cell system.

The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention, and various modifications and changes may be made by those skilled in the art. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.