Description:Complete Specification

The following specification describes and ascertains the nature of this invention and the manner in which it is to be performed.
Field of the invention
[0001] This invention relates to a method to identify hydrogen gas leakage through a pressure relief valve of a hydrogen gas injection system.

Background of the invention
[0002] CN 108232242 A describes a hydrogen management system special for a fuel cell car. The hydrogen management system includes a number of hydrogen bottles, bottle valves mounted on hydrogen bottles, a main hydrogen valve, a whole vehicle controller and a hydrogen management system controller; a temperature sensor and a pressure sensor are arranged on each bottle valve, and the bottle valves with the main hydrogen valve as well as the fuel cell system are connected through pipelines. A pipeline pressure sensor is arranged on the pipeline between the bottle valves and the main hydrogen valve. A pressure relief valve is arranged on the pipeline between the bottle valves and the pipeline pressure sensor. The hydrogen management system also includes hydrogen leakage sensors. The hydrogen leakage sensors are used for detecting whether positions where hydrogen is easy to leak. The invention also discloses a control method of the hydrogen management system special for the fuel cell car. By monitoring the hydrogen temperature, pressure and concentration, hydrogen use is controlled according to the requirements of the whole vehicle. At the same time, the state of a hydrogen supply system is judged, and the fault categories are divided, such as over temperature, over pressure, hydrogen leakage and other faults, aiming at different fault levels, the opening and breaking of a hydrogen supply valve are controlled to ensure the hydrogen use safety and the safety of passengers.

Brief description of the accompanying drawing
[0003] Figure 1 illustrates an algorithm to identify hydrogen gas leakage through a pressure relief valve of a hydrogen gas injection system in one embodiment of the invention.

Detailed description of the embodiments
[0004] Figure 1 illustrates an algorithm 100 to identify hydrogen gas leakage through a pressure relief valve of a hydrogen gas injection system. The algorithm 100 comprises channeling 110 hydrogen gas from a hydrogen tank to a mechanical pressure regulator and subsequently to a solenoid-based pressure regulator, and channeling 120 hydrogen gas from the solenoid-based pressure regulator to a pressure relief valve. The algorithm 100 further comprises venting 130 hydrogen gas from the pressure relief valve to atmospheric air when a pressure of hydrogen gas flowing to the pressure relief valve is above a threshold limit, and determining 140 a drop in pressure of hydrogen gas upstream of the pressure relief valve that is vented from the pressure relief valve to the atmosphere by means of a pressure sensor that is positioned between the hydrogen tank and the mechanical pressure regulator.

[0005] Figure 1 illustrates the algorithm 100 to identify hydrogen gas leakage through the pressure relief valve of the hydrogen gas injection system. The algorithm 100 comprises channeling 110 hydrogen gas from a hydrogen tank to a mechanical pressure regulator. More specifically, the mechanical pressure regulator controls a flow of hydrogen gas from the hydrogen tank to the solenoid-based pressure regulator due to leakage in the mechanical pressure regulator. Therein, the leaked hydrogen gas from the solenoid-based pressure regulator is channeled 120 to the pressure relief valve and accumulates upstream from the pressure relief valve. Once the pressure upstream from the pressure relief valve exceeds an opening pressure of the pressure relief valve which is above a threshold limit that is pre-determined by a user, the hydrogen gas from the pressure relief valve is vented 130 to the atmospheric air. In an exemplary embodiment, a pressure sensor is mounted between the hydrogen tank and the mechanical pressure regulator. More specifically, the pressure sensor that is mounted between the hydrogen tank and the mechanical pressure regulator determines 140 a drop in pressure of hydrogen gas upstream of the pressure relief valve that is vented from the pressure relief valve to the atmosphere. When there is a drop in pressure from the upstream end of the pressure relief valve to the atmosphere, a commensurate pressure drop occurs upstream of the mechanical pressure regulator. Therefore, the drop in pressure sensed by the pressure sensor that is mounted upstream of the mechanical pressure regulator translates to an equivalent drop in pressure of hydrogen gas upstream of the pressure relief valve.

[0006] In an exemplary embodiment, the algorithm 100 comprises determining 150 a frequency in the drop in pressure of hydrogen gas that is vented from the pressure relief valve to the atmosphere. By determining the frequency in the drop in pressure of hydrogen gas that is vented from the pressure relief valve to the atmosphere, it is possible to determine a number of occasions in which the pressure relief valve has leaked and therefore dissipated hydrogen gas to the atmosphere. If the frequency in the drop in pressure of hydrogen gas that is vented from the pressure relief valve to the atmosphere is greater than a threshold frequency that is pre-determined by a user, it may be determined by the user that the pressure relief valve has failed and is therefore required to be replaced.

[0007] In addition, the algorithm 100 comprises determining 160 that one of the mechanical pressure regulator and the variable solenoid based pressure regulator are faulty if the drop in pressure of hydrogen gas upstream of the pressure relief valve that is vented from the pressure relief valve to the atmosphere has been detected by the pressure sensor.
[0008] It must be understood that the embodiments explained above are only illustrative and do not limit the scope of the disclosure. Many modifications in the embodiments with regard to dimensions of various components are envisaged and form a part of this invention. The scope of the invention is only limited by the scope of the claims.

, Claims:We Claim

1. An algorithm (100) to identify hydrogen gas leakage through a pressure relief valve of a hydrogen gas injection system, the algorithm (100) comprising:
channeling (110) hydrogen gas from a hydrogen tank to a mechanical pressure regulator and subsequently to a solenoid-based pressure regulator;
channeling (120) hydrogen gas from the solenoid-based pressure regulator to a pressure relief valve;
venting (130) hydrogen gas from the pressure relief valve to atmospheric air when a pressure of hydrogen gas flowing to the pressure relief valve is above a user defined threshold limit; and
determining (140) a drop in pressure of hydrogen gas upstream of the pressure relief valve that is vented from the pressure relief valve to the atmosphere by means of a pressure sensor that is positioned between the hydrogen tank and the mechanical pressure regulator.

2. An algorithm (100) to identify hydrogen gas leakage through a pressure relief valve of a hydrogen gas injection system in accordance with Claim 1, further comprising determining (150) a frequency of the drop in pressure of hydrogen gas that is vented from the pressure relief valve to the atmosphere.

3. An algorithm (100) to identify hydrogen gas leakage through a pressure relief valve of a hydrogen gas injection system in accordance with Claim 2, further comprising determining (160) that the mechanical pressure regulator and the variable solenoid based pressure regulator are faulty if the drop in pressure of hydrogen gas upstream of the pressure relief valve that is vented from the pressure relief valve to the atmosphere has been detected by the pressure sensor due to the drop in pressure of hydrogen gas upstream of the mechanical pressure regulator, is beyond a set limit, or if a frequency of gas release has increased beyond a set limit.