Multi-stage hydrogen ejector structure

Abstract

The utility model discloses a multi-stage hydrogen ejector structure. The multi-stage hydrogen ejector structure comprises an ejector body, the high-load ejection loop assembly is arranged on the ejector body, and the high-load ejection loop assembly and the ejector body jointly form a high-load ejection loop; the high-load injection nozzle is arranged at an injection port of the high-load injection loop; the low-load ejection loop assembly is arranged on the ejector body and forms a low-load ejection loop together with the ejector body; and the low-load injection nozzle is arranged at an injection port of the low-load injection loop. According to the utility model, the two injection loops work cooperatively under different loads, so that the hydrogen requirements of the electric pile under different working conditions are met, 0-100% coverage of the electric pile power is realized, the electric pile power generation efficiency is improved, and the problem that the efficiency is low when the existing hydrogen fuel cell is in low load is solved.

Description

Technical Field

[0001] The utility model belongs to the field of hydrogen fuel cells, and particularly relates to a multi-stage hydrogen ejector structure. Background Art

[0002] At present, in the field of hydrogen fuel cells, the most common ejector is a single-stage hydrogen ejector.

[0003] The working principle of the single-stage hydrogen ejector is as follows: Hydrogen enters the ejector through a high-pressure connector. The on-off of the intake passage is controlled by a switch valve, and the hydrogen pressure and flow rate are controlled by a pressure regulating valve. Finally, the high-pressure hydrogen enters the ejector nozzle and is introduced into the fuel cell stack. The low-pressure hydrogen that enters the fuel cell stack but does not react returns to the ejector nozzle through a low-pressure connector and re-enters the fuel cell stack after being pressurized by the high-pressure hydrogen.

[0004] Since a hydrogen fuel cell requires a large ejection ratio at low loads and a small ejection ratio at high loads, this single-stage hydrogen ejector with only one ejector nozzle cannot cover the full power range of the fuel cell, and has low ejection efficiency and high hydrogen consumption at 0-10% load. Summary of the Utility Model

[0005] In order to solve the technical problem of low efficiency of hydrogen fuel cells at low loads in the prior art, a multi-stage hydrogen ejector structure is provided.

[0006] The utility model provides a multi-stage hydrogen ejector structure, including:

[0007] An ejector body;

[0008] A high-load ejection loop assembly, which is arranged on the ejector body and jointly forms a high-load ejection loop with the ejector body;

[0009] A high-load ejection nozzle, which is arranged at the ejection port of the high-load ejection loop;

[0010] A low-load ejection loop assembly, which is arranged on the ejector body and jointly forms a low-load ejection loop with the ejector body;

[0011] A low-load ejection nozzle, which is arranged at the ejection port of the low-load ejection loop.

[0012] In some embodiments, the high-load ejection loop and the low-load ejection loop have a common ejection return section.

[0013] In some embodiments, the high-load ejection nozzle and the low-load ejection nozzle are respectively communicated with the fuel cell stack.

[0014] In some embodiments, when the fuel cell is at high load, the high-load ejector loop is in an open state while the low-load ejector loop is in a closed state, and the high-load ejector nozzle has hydrogen from the high-load ejector loop and leading to the stack.

[0015] In some embodiments, when the fuel cell is at low load, the low-load ejector loop is in an open state while the high-load ejector loop is in a closed state, and the low-load ejector nozzle has hydrogen from the low-load ejector loop and leading to the stack.

[0016] In some embodiments, it further includes: a first reflux unit connecting the stack and the high-load ejector loop;

[0017] When the fuel cell is at high load, the high-load ejector loop has unreacted hydrogen from the stack and flowing in through the first reflux unit.

[0018] In some embodiments, it further includes: a second reflux unit connecting the stack and the low-load ejector loop;

[0019] In some embodiments, the low-load ejector loop has unreacted hydrogen from the stack and flowing in through the second reflux unit.

[0020] In some embodiments, the high-load ejector loop assembly includes: a high-pressure joint for introducing hydrogen into the common ejector loop section, a switch valve, a high-pressure sensor, and a first pressure regulating valve provided on the ejector loop section, and a first safety valve, a first low-pressure sensor, and a first temperature sensor provided on the independent ejector loop section of the high-load ejector loop;

[0021] Wherein, the independent ejector loop section and the common ejector loop section of the high-load ejector loop are arranged on the high-load ejector loop in the order of hydrogen flow.

[0022] In some embodiments, in addition to the high-pressure joint, the high-pressure sensor, the switch valve, and the first pressure regulating valve, the low-load ejector loop assembly further includes; a second pressure regulating valve, a second safety valve, a second low-pressure sensor, and a second temperature sensor provided on the independent ejector loop section of the low-load ejector loop;

[0023] Wherein, the independent ejector loop section and the common ejector loop section of the low-load ejector loop are arranged on the low-load ejector loop in the order of hydrogen flow.

[0024] In some embodiments, the low-load ejector nozzle adopts an ejector nozzle with a large entrainment ratio, while the high-load ejector nozzle adopts an ejector nozzle with a small entrainment ratio. Here, the entrainment ratio is the ratio of the mass flow rate of entrained hydrogen to the mass flow rate of working hydrogen (hydrogen consumed by the fuel cell stack). The large entrainment ratio is between 2.5 and 3.5, and the small entrainment ratio is between 0.5 and 1.5.

[0025] Compared with the prior art, the technical effects achieved by the present utility model are as follows:

[0026] On the basis of the prior art, the present utility model adds an entrainment passage (low-load entrainment loop) and arranges an ejector nozzle with a large entrainment ratio (low-load ejector nozzle) at the new entrainment port. When the fuel cell is at low load, hydrogen enters the fuel cell stack through the low-load ejector nozzle; when the fuel cell is at high load, hydrogen enters the fuel cell stack through the high-load ejector nozzle. The present utility model can meet the hydrogen demand of the fuel cell stack under different working conditions, achieve 0% - 100% coverage of the fuel cell stack power, improve the power generation efficiency of the fuel cell stack, and reduce hydrogen consumption. Description of the Drawings

[0027] Figure 1 is an axonometric view of the ejector assembly provided by the present utility model in an embodiment;

[0028] Figure 2 is a front view of the ejector assembly provided by the present utility model in an embodiment;

[0029] Figure 3 is a bottom view of the ejector assembly provided by the present utility model in an embodiment;

[0030] Figure 4 is a left view of the ejector assembly provided by the present utility model in an embodiment;

[0031] Figure 5 is Figure 2 a sectional view taken along line A-A in

[0032] Figure 6 is Figure 2 a sectional view taken along line B-B in

[0033] Figure 7 is Figure 3 a sectional view taken along line C-C in

[0034] Figure 8 is Figure 3 a sectional view taken along line D-D in Detailed Embodiments

[0035] The technical solution of the present utility model will be described below in conjunction with the accompanying drawings through specific embodiments. It should be understood that one or more steps mentioned in the present utility model do not exclude the existence of other methods and steps before and after the combined steps, or other methods and steps can be inserted between these explicitly mentioned steps. It should also be understood that these examples are only used to illustrate the present utility model and not to limit the scope of the present utility model. Unless otherwise specified, the numbers of each method step are only for the purpose of identifying each method step, rather than restricting the arrangement order of each method or limiting the implementation scope of the present utility model. The change or adjustment of their relative relationship can also be regarded as the implementable scope of the present utility model under the condition of no substantial change in technical content.

[0036] There is no specific restriction on the sources of the raw materials and instruments used in the embodiments, and they can be purchased in the market or prepared according to the conventional methods well-known to those skilled in the art.

[0037] The present utility model provides a multi-stage hydrogen ejector structure, which solves the problem that since a hydrogen fuel cell requires a large entrainment ratio at low loads and a small entrainment ratio at high loads, a single-stage hydrogen ejector with only one entrainment nozzle cannot cover the full power range of the fuel cell, and has low entrainment efficiency and large hydrogen consumption at 0-10% load.

[0038] As Figure 1 shown, in one embodiment, a multi-stage hydrogen ejector structure is provided, including: an ejector body 3, a high-load entrainment loop assembly, a high-load entrainment nozzle 10, a low-load entrainment nozzle, and a low-load entrainment loop assembly. The low-load entrainment nozzle uses an entrainment nozzle with a large entrainment ratio, while the high-load entrainment nozzle uses an entrainment nozzle with a small entrainment ratio. Among them, the entrainment ratio is the ratio of the mass flow rate of entrained hydrogen to the mass flow rate of working hydrogen. The large entrainment ratio is between 2.5 and 3.5, and the small entrainment ratio is between 0.5 and 1.5.

[0039] As Figures 2 - 6 shown, the ejector body 3 is generally in an irregular box shape, and its interior has a cavity for configuring a high-load entrainment loop and a low-load entrainment loop. The ejector body 3 is provided with plugs for sealing high-pressure hydrogen. For example, a first plug 17, a second plug 18, a third plug 19, and a fourth plug 20. Among them, the first plug 17 is embedded in the front wall of the ejector body 3; the second plug 18 is installed on the common entrainment return section of the high-load entrainment loop and is located between the high-pressure sensor 2 and the switching valve 4; the third plug 19 is embedded in the left side wall of the ejector body 3; the fourth plug 20 is embedded in the left side wall of the ejector body 3 near the high-pressure joint 1.

[0040] As Figure 2As shown in the figure, the high-load ejector loop assembly is arranged on the ejector body 3 and together with the ejector body 3 constitutes a high-load ejector loop. In one embodiment, the high-load ejector loop assembly includes a high-pressure joint 1 installed on the left side wall of the ejector body 3; a high-pressure sensor 2 is installed on the upper surface of the ejector body 3 and is internally connected to the common ejector return section of the high-load ejector loop, and is used to monitor the pressure of high-pressure hydrogen in the common ejector return section of the high-load ejector loop; a switch valve 4 is installed on the upper surface of the ejector body 3 and is internally connected to the common ejector return section of the high-load ejector loop, and is used to control the on-off of the passage of the common ejector return section of the high-load ejector loop; a pressure regulating valve 5 is installed on the upper surface of the ejector body 3 and is internally connected to the common ejector return section of the high-load ejector loop, and is used to control the pressure and flow rate of hydrogen in the common ejector return section of the high-load ejector loop; a safety valve 6 is installed on the upper surface of the ejector body 3 and is internally connected to the independent ejector return section of the high-load ejector loop, and is used to limit the maximum pressure and relieve pressure of the independent ejector return section of the high-load ejector loop; a low-pressure sensor 7 is installed on the upper surface of the ejector body 3 and is internally connected to the independent ejector return section of the high-load independent ejector loop, and is used to monitor the hydrogen pressure after pressure reduction in the independent ejector return section of the high-load ejector loop; a temperature sensor 8 is installed on the upper surface of the ejector body 3 and is internally connected to the independent ejector return section of the high-load ejector loop, and is used to monitor the hydrogen temperature in the independent ejector return section of the high-load ejector loop.

[0041] As Figures 2 - 6 shown, the low-load ejector loop assembly is arranged on the ejector body 3 and together with the ejector body 3 constitutes a low-load ejector loop; in one embodiment, in addition to including the components that are connected to the common ejector return section of the high-load ejector loop and communicate with the common ejector return section of the high-load ejector loop, the low-load ejector loop assembly further includes a pressure regulating valve 16, the pressure regulating valve 16 is installed on the upper surface of the ejector body 3 and is internally connected to the low-load ejector return section, and is used to control the hydrogen pressure and flow rate in the low-load ejector return section during low load; a safety valve 15 is installed on the upper surface of the ejector body 3 and is internally connected to the low-load ejector return section, and is used to limit the maximum pressure and relieve pressure of the low-load ejector return section; a low-pressure sensor 14 is installed on the upper surface of the ejector body 3 and is internally connected to the low-load ejector return section, and is used to monitor the hydrogen pressure after pressure reduction in the low-load ejector return section; a temperature sensor 13 is installed on the upper surface of the ejector body 3 and is internally connected to the low-load ejector return section, and is used to monitor the hydrogen temperature in the low-load ejector return section.

[0042] As Figure 2 and Figure 5As shown, the high-load ejector nozzle 10 is arranged at the ejector port of the high-load ejector loop; in one embodiment, when the fuel cell is in a high-load state, there is unreacted hydrogen in the high-load ejector loop that comes from the stack and flows in through the low-pressure joint 9. The high-load ejector nozzle 10 is installed on the right side wall of the ejector body 3 and is connected to the reaction stack; the first return unit is installed on the front side wall of the ejector body 3 and is used to connect the stack to the high-load ejector loop. In one embodiment, the first return unit uses the low-pressure joint 9.

[0043] As Figure 6 shown, the low-load ejector nozzle 11 is arranged at the ejector port of the low-load ejector loop. In one embodiment, the low-load ejector nozzle 11 is installed on the right side wall of the ejector body 3 and is connected to the reaction stack, and the second return unit is installed on the rear side wall of the ejector body 3 and is used to connect the stack to the low-load ejector loop. In one embodiment, the second return unit uses the low-pressure joint 12.

[0044] As Figure 7 and 8 shown, in one embodiment, the high-load ejector loop and the low-load ejector loop have a common ejector return section. When the stack is operating, the common ejector return section is in an open state.

[0045] As Figure 1 and 2 shown, the specific installation method of this multi-stage hydrogen ejector structure is as follows:

[0046] First, install the second plug 18 to seal the high-pressure hydrogen in the common ejector return section of the high-load ejector loop, and then install the high-pressure joint 1 to connect the high-pressure hydrogen in the vehicle-mounted high-pressure gas storage tank. Install the high-pressure sensor 2 to monitor the pressure of the high-pressure hydrogen, install the switch valve 4 to control the opening and closing of the passage. Install the pressure regulating valve 15 to control the pressure and flow rate of hydrogen during high load, install the safety valve 6 to limit the maximum pressure of the high-load passage and relieve pressure. Then install the low-pressure sensor 7 to monitor the pressure of the hydrogen after pressure reduction, then install the temperature sensor 8 to monitor the temperature of the hydrogen in the high-load passage, install the high-load ejector nozzle 10 to boost the pressure and intake hydrogen during high load, and then install the low-pressure joint 9 to recover the unreacted low-pressure hydrogen.

[0047] Secondly, install the pressure regulating valve 16 to control the pressure and flow rate of hydrogen during low load, and then install the safety valve 15 to limit the maximum pressure of the high-load passage and relieve pressure. Then install the low-pressure sensor 14 to monitor the pressure of the hydrogen after pressure reduction, then install the temperature sensor 13 to monitor the temperature of the hydrogen in the high-load passage. Then install the low-load ejector nozzle 11 to boost the pressure and intake hydrogen during low load, and then install the low-pressure joint 12 to recover the unreacted low-pressure hydrogen.

[0048] The last components to be installed are the screw plugs 17, 19, and 20, which are used to seal the high-pressure hydrogen in the pipeline.

[0049] The assembled ejector assembly is installed at the hydrogen inlet of the fuel cell stack. The high-load ejector nozzle 10 and the low-load ejector nozzle 11 are connected to the hydrogen inlet of the stack and are responsible for delivering hydrogen into the stack. The low-pressure connectors 9 and 12 are connected to the hydrogen outlet of the stack and are responsible for recovering the unreacted hydrogen. The high-pressure connector 1 is connected to the vehicle-mounted hydrogen storage system and is responsible for receiving the high-pressure hydrogen in the hydrogen storage tank.

[0050] When the fuel cell is at high load (10% - 100%), the hydrogen in the hydrogen storage tank enters the ejector assembly through the high-pressure connector 1. When the fuel cell is at high load, the hydrogen enters the ejector body 3 through the high-pressure connector 1. The pressure of the high-pressure hydrogen is monitored by the high-pressure sensor 2, and the hydrogen inlet and outlet are controlled by the switch valve 4. After the hydrogen passes through the switch valve 4, the pressure regulating valve 16 is closed at this time, and the hydrogen enters the pressure regulating valve 15 for pressure reduction. Then it passes through the safety valve 6, the low-pressure sensor 7, and the temperature sensor 8 in sequence, and finally enters the high-load ejector nozzle 10. A strong negative pressure is formed at the intersection of the high-load ejector nozzle 10 and the low-pressure connector 9, sucking the atmospheric-pressure hydrogen flowing back at the low-pressure connector 9 into the high-load ejector nozzle 10. After mixing with the high-pressure hydrogen, it enters the stack.

[0051] When the fuel cell is at low load (0 - 10%), the hydrogen in the hydrogen storage tank enters the ejector assembly through the high-pressure connector 1. The pressure of the high-pressure hydrogen is monitored by the high-pressure sensor 2, and the hydrogen inlet and outlet are controlled by the switch valve 4. After the hydrogen passes through the switch valve 4, it enters the channel opened by the screw plug 17 to the low-load ejector independent channel. At this time, the pressure regulating valve 5 is in the closed state, and the hydrogen enters the pressure regulating valve 16 for pressure reduction treatment. Then it passes through the safety valve 15, the low-pressure sensor 14, and the temperature sensor 13 in sequence, and finally enters the low-load ejector nozzle 11. A strong negative pressure is formed at the intersection of the low-load ejector nozzle 11 and the low-pressure connector 12, sucking the atmospheric-pressure hydrogen flowing back at the low-pressure connector 12 into the low-load ejector nozzle 11. After mixing with the high-pressure hydrogen, it enters the stack.

[0052] This multi-stage hydrogen ejector structure can achieve full-power coverage of the overall ejector ratio through the cooperation of two ejector circuits, improving the hydrogen utilization efficiency.

[0053] The foregoing description of the specific exemplary embodiments of the present utility model is for purposes of illustration and exemplification. These descriptions are not intended to limit the present utility model to the precise forms disclosed, and it is apparent that many changes and variations are possible in light of the above teachings. The purpose of selecting and describing the exemplary embodiments is to explain the specific principles of the present utility model and its practical applications, so that those skilled in the art can implement and utilize the various different exemplary embodiments of the present utility model, as well as various different selections and changes. The scope of the present utility model is intended to be defined by the claims and their equivalents.

Claims

1. A multi-stage hydrogen ejector structure, characterized in that: include: ejector body; A high-load ejector circuit assembly is disposed on the ejector body and together with the ejector body forms a high-load ejector circuit; A high-load injection nozzle is arranged at the injection port of the high-load injection circuit; A low-load ejector circuit assembly is disposed on the ejector body and together with the ejector body forms a low-load ejector circuit; The low-load injection nozzle is arranged at the injection port of the low-load injection circuit.

2. The multi-stage hydrogen ejector structure according to claim 1, characterized in that: The high-load ejector circuit and the low-load ejector circuit have a common ejector circuit section.

3. The multi-stage hydrogen ejector structure according to claim 2, characterized in that: The high-load ejector nozzle and the low-load ejector nozzle are respectively connected to the fuel cell stack.

4. The multi-stage hydrogen ejector structure according to claim 3, characterized in that: When the fuel cell is under high load, the high load ejector circuit is in an open state and the low load ejector circuit is in a closed state, and the high load ejector nozzle contains hydrogen from the high load ejector circuit and flows to the fuel cell stack.

5. The multi-stage hydrogen ejector structure according to claim 3, characterized in that: When the fuel cell is under low load, the low load ejection circuit is in an open state and the high load ejection circuit is in a closed state, and the low load ejection nozzle contains hydrogen from the low load ejection circuit and flows to the fuel cell stack.

6. The multi-stage hydrogen ejector structure according to claim 3, characterized in that: Also includes: A first reflux unit connecting the battery stack to the high-load ejection loop; When the fuel cell is under high load, the high-load ejector circuit contains unreacted hydrogen gas that flows from the fuel cell stack through the first reflow unit.

7. The multi-stage hydrogen ejector structure according to claim 3, characterized in that: Also includes: A second reflux unit connecting the battery stack to the low-load ejection loop; When the fuel cell is under low load, the low load ejector circuit contains unreacted hydrogen gas that comes from the fuel cell stack and flows in through the second reflow unit.

8. The multi-stage hydrogen ejector structure according to claim 2, characterized in that: The high-load ejector circuit assembly includes: a high-pressure joint of the common ejector circuit section for introducing hydrogen, a switch valve, a high-pressure sensor and a first pressure regulating valve arranged on the ejector circuit section, and a first safety valve, a first low-pressure sensor and a first temperature sensor arranged on the independent ejector circuit section of the high-load ejector circuit; The independent ejection circuit section and the common ejection circuit section of the high-load ejection circuit are arranged on the high-load ejection circuit in the order in which the hydrogen flows.

9. The multi-stage hydrogen ejector structure according to claim 8, characterized in that: In addition to the high-pressure connector, the high-pressure sensor, the switch valve and the first pressure regulating valve, the low-load ejection circuit assembly further includes: a second pressure regulating valve, a second safety valve, a second low-pressure sensor and a second temperature sensor provided on an independent ejection circuit section of the low-load ejection circuit; The independent ejection circuit section and the common ejection circuit section of the low-load ejection circuit are arranged on the low-load ejection circuit in the order in which the hydrogen gas flows.

10. The multi-stage hydrogen ejector structure according to claim 1, characterized in that: The low-load ejector nozzle adopts an ejector nozzle with a large ejection ratio, while the high-load ejector nozzle adopts an ejector nozzle with a small ejection ratio, wherein the ejection ratio is the ratio of the mass flow rate of the ejected hydrogen to the mass flow rate of the working hydrogen, the large ejection ratio is 2.5-3.5, and the small ejection ratio is 0.5-1.5.

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