Nozzle, ejector based on nozzle and having adjustable flow characteristic, and application of ejector

Abstract

The invention discloses a nozzle, an ejector based on the nozzle and having an adjustable flow characteristic, and application of the ejector. The nozzle comprises a nozzle body, a small nozzle, a large nozzle and an elastic part; a thin and long hollow pipe with a valve is adopted as the small nozzle, and the elastic part is arranged between the set of large nozzle and the set of small nozzle; one end of the elastic part jacks the valve part of the small nozzle, and the other end of the elastic part jacks the large nozzle; and the elastic part can change the position of the valve of the smallnozzle under the effect of to-be-ejected gas, and then a flowing path of the to-be-ejected gas is controlled. The supply quantities of hydrogen and recycled hydrogen are automatically controlled by the nozzle according to system loads; when the low load exists, the small nozzle acts, the pressure of a nozzle outlet is small, the recovery rate of the recycled hydrogen is high, and the hydrogen utilization rate is increased; when the medium-high loads exist, the two sets of nozzles act simultaneously, and the large nozzle is used for enlarging the circulating area to provide the larger fuel flow; and the small nozzle is used for increasing the ejecting speed to improve properties of the ejector.

Description

technical field [0001] The present disclosure relates to the technical field of fuel injection, in particular to a nozzle, an injector adjustable based on the flow characteristics of the nozzle and applications thereof. Background technique [0002] With the continuous development of the global economy, people's demand for energy is also increasing. The consumption of traditional energy also produces a large amount of pollutants, so the development of clean new energy that can replace traditional energy is becoming more and more important. A fuel cell is a device that converts chemical energy into electrical energy. It has the characteristics of high energy conversion efficiency, zero pollution, and zero noise, so the application of fuel cells has broad development prospects. [0003] The fuel cell system is mainly composed of a fuel cell stack (for chemical reactions), a fuel supply system (for fuel such as hydrogen), an air supply system (for oxygen in the air), and a coo...

AI Technical Summary

Problems solved by technology

[0004] The inventor found in the research that in the fuel supply system, the hydrogen entering the fuel cell stack cannot be completely consumed, and some of it has been discharged from the cell stack without reaction, which leads to the fact that the actual efficiency of the cell stack is lower than the theoretical efficiency

Especially when running at low load, the fuel utilization rate drops, and a large amount of unconsumed hydrogen is produced

This not only reduces the efficiency of the fuel cell, but also greatly wastes resources; but when the load is running, the current rises step by step, and the utilization rate of hydrogen in the battery stack rises sharply, and there may even be insufficient hydrogen, and the actual efficiency of the battery stack is high. Anomalies in theoretical efficiency

Insufficient hydrogen will cause the local temperature of the battery to rise, the proton exchange membrane will be burned through, and the activity of the reaction catalyst at the electrode will also decrease, reducing the service life of the battery stack

The main reason for the lack of hydrogen is that the action of the solenoid valve lags behind the flow of hydrogen relative to the load change.

[0005] In order to solve this problem, the supply of hydrogen is often increased to reduce the response time of the solenoid valve, but this will generate a large amount of unconsumed hydrogen, and the efficiency of fuel use will be greatly reduced

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