The work of the hydrogen ejector relies on the pressure difference to achieve the injection of hydrogen. Under different pressure conditions, the internal fluid mechanics process will change significantly. When the hydrogen supply pressure is higher, the hydrogen gas has greater potential energy and can pass through the injector nozzle at a higher speed.
For example, when a high-pressure hydrogen storage tank is used as the gas source, hydrogen is rapidly expanded and ejected at an accelerated rate driven by greater pressure. Under low-pressure conditions, the flow rate of hydrogen is relatively low and the injection power is relatively weak. This pressure change directly affects key parameters such as the flow rate, speed and injection shape of hydrogen injection, which in turn has a fundamental impact on injection stability.
2. Injection stability performance under high pressure conditions
Under high-pressure conditions, hydrogen ejector faces some special challenges and characteristics. On the one hand, high pressure can ensure a large hydrogen flow output and meet some application scenarios with large demand for hydrogen, such as hydrogen supply for large hydrogen fuel cell power stations. However, high pressure can also easily cause pressure fluctuations during injection. Due to the compressibility of hydrogen, when high-pressure hydrogen flows rapidly in the injector, local pressure changes may cause flow rate instability.
For example, under the action of a momentary high-pressure pulse, the flow rate of hydrogen injection may experience a brief surge or fluctuation, affecting the uniformity and stability of the injection. In addition, the high-pressure environment has higher requirements on the material and sealing performance of the injector. If the material strength is insufficient or there is a slight leak in the seal, it will also lead to pressure instability, thereby affecting the injection stability.
3. Injection stability characteristics under low pressure conditions
Under low-pressure conditions, the injection stability of hydrogen ejector has different performances. Although the flow rate is relatively small, precise control is needed to ensure a stable hydrogen supply. At low pressure, the flow rate of hydrogen is low and is easily disturbed by external factors.
For example, small resistance changes and temperature fluctuations in the pipeline may have a significant impact on the injection of hydrogen. Due to the lower pressure, the atomization effect of hydrogen at the nozzle may not be as good as high-pressure conditions, and larger droplets or uneven spray patterns may appear, which will also affect the stability of the spray. Moreover, in some applications that require frequent starting and stopping or adjusting hydrogen flow in a low-pressure range, such as the hydrogen injection system of small hydrogen fuel cell vehicles, how to respond quickly and maintain stable injection under low-pressure conditions has become a key issue, which requires The injector has high-precision flow adjustment and feedback control mechanisms.
4. Measures to improve injection stability under different pressure conditions
In order to improve the injection stability of hydrogen ejector under different pressure conditions, various measures can be taken. In terms of design, the structure of the nozzle is optimized to maintain good atomization and flow control performance under different pressures.
For example, adjustable nozzle diameter or special flow channel design can be used to adapt to pressure changes. For high-pressure working conditions, the pressure-resistant structural design of the injector should be strengthened, high-strength materials should be used, and the pressure buffer and adjustment device should be improved to reduce the impact of pressure fluctuations on injection. Under low-pressure conditions, improve the accuracy of flow sensors and controllers and enhance resistance to external interference, such as using heat insulation, shock absorption and other measures to reduce the effects of temperature and vibration on hydrogen injection. At the same time, a complete monitoring and feedback system has been established to monitor the working status of the injector in real time and adjust injection parameters in a timely manner according to pressure changes to ensure stable and reliable hydrogen injection under various pressure conditions to meet the growing needs of hydrogen applications. growing demand.
