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 is related to a control unit for performing a diagonstic check on a hydrogen tank valve in a vehicle and a method of working of the control unit.

Background of the invention
[0002] The vehicle-mounted hydrogen supply system is an important component of a fuel cell vehicle, and the system is an energy storage system for providing hydrogen fuel with stable pressure for the fuel cell system and is equivalent to a fuel tank in a traditional vehicle. At present, the simplest and most common vehicle-mounted hydrogen supply systems adopt a method of storing compressed hydrogen, namely, the compressed hydrogen is stored in a hydrogen storage bottle, the compressed hydrogen is sent to a fuel cell engine after being subjected to multistage pressure reduction, and chemical reaction is carried out in the fuel cell engine to release electric energy so as to drive an automobile to run. in the scheme of the vehicle-mounted hydrogen fuel hydrogen supply system on the market at present, various valve distributed structures are adopted and are installed on site.

[0003] A CN patent application 212062589 discloses a utility model provides an integrated hydrogen supply control panel system for fuel cells, which comprises a panel, wherein a hydrogen adding port, a pressure gauge, a stop valve and a high-low pressure emptying valve are fixed on the panel, a pressure regulating valve is fixed on the back surface of the panel, the air inlet end of the pressure regulating valve is connected with a filter, and the filter is connected with the stop valve; the air outlet end of the pressure regulating valve is provided with a pipeline connected with a normally closed electromagnetic valve; the hydrogenation port is connected with the pressure gauge through a three-way joint, and the three-way joint is communicated with a four-way joint between the filter and the stop valve; one port of the high-low pressure emptying valve is connected to a four-way joint between the filter and the stop valve, and the other port of the high-low pressure emptying valve is connected to a pipeline between the pressure regulating valve and the electromagnetic valve.

Brief description of the accompanying drawings
[0004] Figure 1 illustrates a control unit for performing a diagnostic check on a hydrogen tank valve in a vehicle, in accordance with an embodiment of the invention; and
[0005] Figure 2 illustrates a flow chart of a method for working of the control unit, in accordance with the present invention.

Detailed description of the embodiments
[0006] Figure 1 illustrates a control unit for determining a dosing module tip temperature in a vehicle, in accordance with an embodiment of the invention. The vehicle 11 comprises at least one hydrogen tank 14 and a corresponding check valve 15 and a corresponding shutoff valve 12 connected to the hydrogen tank 14. The control unit 10 detects an operating condition of the vehicle 11 and switch on the shutoff valve 12 of each of the hydrogen tank 14. The control unit 10 then detects a pressure via a pressure sensor 16 when the shutoff valve 12 is switched on for a predefined amount of time. Further the control unit 10 determines a pressure gradient value and a pressure value received from the pressure sensor 16 for sensing a malfunction in the shutoff valve 12 and performs the diagnostic check on the shutoff valve 12 of each of the hydrogen tank 14 based on the determined pressure gradient value and the pressure value.

[0007] The control unit 10 is chosen from a group of control units comprising a microprocessor, a microcontroller, a digital circuit, an integrated chip, and the like. The control unit is positioned inside the vehicle or in a service center 20 where the diagnostic check is performed. Each of the shutoff valve 12 of the corresponding hydrogen tank 14 is connected to the control unit 10 . The control unit 10 further connected to the pressure sensor 16 for receiving the detected pressure value during the switching on of the shutoff valve 12 and the during the engine 18 off condition for determining the base pressure value.

[0008] The vehicle 11 comprises one or more hydrogen tank 14 connected to each other. Each of the hydrogen tank 14 comprises two valves, one being the check valve 15 and the other being the shutoff valve 12. The check valve 15 is opened by the control unit 10 whenever there is a detection of the refueling event is occurred. Through the refueling receptacle, the hydrogen fuel is filled into the each of the hydrogen tank 14. During the operating condition of the vehicle 11, the control unit 10 switches off the check valve 15 and the switches on/opens the shut off valve 12 of each of the hydrogen tank 14 , such that, the hydrogen from the hydrogen tank 14 is pumped into an engine 18 of the vehicle 11 via the high-pressure line. The high-pressure line comprises a pressure sensor 16 and a pressure regulator 22, such that, the hydrogen going into the engine 18 is pressurized and the pressure is modified in the pressure regulator 22 as per the requirement. The pressure sensor 16 senses the pressure at each of the hydrogen tank valve (shut off valve 12). From the determined pressure , the control unit 10 calculates the pressure value and the pressure gradient value.

[0009] The diagnostic check on the hydrogen tank valve 12 can be performed during multiple operating conditions of the vehicle 11. Few such conditions are, when the vehicle 11 is in a running condition or immediately after a refuel or when an engine18 of the vehicle 11 is switched off/switched on or during vehicle service in a service center 20. The control unit 10 performs the diagnostic check on each of the shutoff valve 12 of each of the hydrogen tank 14 of the vehicle 11 by switching on the shutoff valve 12, one at a time. The control unit for determining the amount of hydrogen in the cylinder (state of charge) we use rate of change in pressure & gas temperature information.The temperature sensors are mounted in each tank. Alternatively a temperature sensor in the line(near pr. Sensor) can be used.

[0010] Figure 2 illustrates a flow chart of a method for working of the control unit 10 for performing the diagnostic check on a hydrogen tank valve 12, in accordance with the present invention. The vehicle 11 comprising at least one hydrogen tank 14 and a corresponding check valve 15 and a corresponding shutoff valve 12 connected to the hydrogen tank 14. In step S1,an operating condition of the vehicle 11 is detected and the shutoff valve 12 of each of the hydrogen tank 14 is switched on. In step S2, a pressure is detected via a pressure sensor 16 when the shutoff valve 12 is switched on for a predefined amount of time. In step S3,a pressure gradient value and a pressure value is determined that is received from the pressure sensor 16 for sensing a malfunction in the shutoff valve 12. In step S4, the diagnostic check on the shutoff valve 12 of each of the hydrogen tank 14 is performed based on the determined pressure gradient value and the pressure value.

[0011] The method is explained in detail, by taking one of the vehicle operating conditions into consideration. i.e., when the vehicle 11 is switched off. Upon detecting the switch off of the engine 18 of the vehicle 11 , the control unit 10 maintains the operating condition of the engine 18 at t15 stage. The control unit 10 then switches on the shutoff valve 12 of each of the hydrogen tanks 14. For instance, if there are three hydrogen tanks 14 in the vehicle 11, the control unit 10 switches the first shut off valve 12 of the first hydrogen tank 14 for the predefined time. The high-pressure sensor 16 in the high-pressure line connecting the hydrogen tank 14 and the engine 18 of the vehicle 11, senses the base pressure before the actuation of the shutoff valve 12. When one shutoff valve 12 is actuated for the predefined amount of time, the pressure in the high-pressure area increases. The gradient of the pressure rise is determined and is used for calculating the quantity of hydrogen in that particular hydrogen tank 14.

[0012] The control unit 10 then determines the pressure gradient value being above the minimum value and the pressure value being above the base pressure level for detecting the working state of the shutoff. For example, if there is a minimum increase in pressure is not reached, or/and the minimum pressure gradient is reached, then the shut off valve 12 is suspected to be defective by the control unit 10. This method of detecting is repeated for rest of the two hydrogen tanks 14 and results are compared. This diagnosis method is made in conjunction with an electrical continuity check for the valves 12 of the each of the hydrogen tank 14. Based on the detected working state of the shutoff valve 12, the control unit 10 generates an alert via the communication means to the user of the vehicle 11.

[0013] With the above control unit 10 and the method, the working state of the shutoff valve 12 can be determined effectively. In addition to this, the above disclosed method, further provides the information on the quantity of the hydrogen fuel level in each of the hydrogen tank 14 based on the determined pressure gradient value ( the pressure gradient value should be above the minimum value). The methodology provides a low-cost effective solution.

[0014] Embodiments explained in the description above are only illustrative and do not limit the scope of this invention. Many such embodiments and other modifications and changes in the embodiment explained in the description are envisaged. The scope of the invention is only limited by the scope of the claims.
, Claims:We Claim:
1. A control unit (10) for performing a diagnostic check on a hydrogen tank valve (12) in a vehicle (11), said vehicle (11) comprising at least one hydrogen tank (14) and a corresponding check valve (15) and a corresponding shutoff valve (12) connected to the hydrogen tank (14),
said control unit (10) adapted to :
- detect an operating condition of the vehicle(11) and switch on the shutoff valve (12) of each of the hydrogen tank (14);
- detect a pressure via a pressure sensor (16) when said shutoff valve (12) is switched on for a predefined amount of time ;
- determine a pressure gradient value and a pressure value received from said pressure sensor (16) for sensing a malfunction in said shutoff valve (12);
- perform the diagnostic check on the shutoff valve (12) of each of the hydrogen tank (14) based on the determined pressure gradient value and the pressure value.

2. The control unit (10) as claimed in claim 1, wherein the diagnostic check is performed when the vehicle (11) is in any one of the operating conditions comprising a running condition, immediately after a refuel, when an engine (18) of the vehicle (11) is switched off/switched on, during vehicle service.

3. The control unit (10) as claimed in claim 1, wherein the shutoff valve (12) of each of the hydrogen tank (14) of the vehicle (11) is switched on , one at a time for performing the diagnostic check.

4. The control unit (10) as claimed in claim 1, wherein the control unit (10) performs the diagnostic check for determining the working state of the shutoff valve (12) and the quantity of hydrogen present in the corresponding hydrogen tank (14) based on the determined pressure value.

5. The control unit (10) as claimed in claim 1, wherein the control unit (10) detects the malfunction of the shutoff valve (12), when the determined pressure value above a base pressure value and the quantity of the hydrogen when the pressure gradient value is above a minimum value.

6. The control unit (10) as claimed in claim 1, wherein the control unit (10) adapted to generate an alert is generated based on the above determination via a communication means.

7. The method of performing a diagnostic check on a hydrogen tank valve (12) in a vehicle (11) by a control unit (10). The vehicle (11) comprising at least one hydrogen tank (14) and a corresponding check valve (15), and a corresponding shutoff valve (12) connected to the hydrogen tank (14),
Said method comprising :
- detecting an operating condition of the vehicle (11) and switching on the shutoff valve (12) of each of the hydrogen tank (14);
- detecting a pressure via a pressure sensor (16) when said shutoff valve (12) is switched on for a predefined amount of time ;
- determining a pressure gradient value and a pressure value received from said pressure sensor (16) for sensing a malfunction in said shutoff valve (12);
- performing the diagnostic check on the shutoff valve (12) of each of the hydrogen tank (14) based on the determined pressure gradient value and the pressure value.