A device to determine pressure leakage in a hydrogen injection pressure regulator and method thereof

Abstract

The device (120) to determine pressure leakage in a Hydrogen Injection Pressure Regulator (HIPR) (104) is disclosed. The HIPR (104) comprises the SIV (116) at inlet and the PV (118) at outlet. The device (120) comprises a controller, characterized in that, the controller configured to close the SIV (116) and the PV (118), measure a first pressure inside the HIPR (104) using the mounted pressure sensor (122) at a first time instant of closure of the SIV (116) and the PV (118). The controller further measures a second pressure inside the HIPR (104) at a second time instant before opening of at least one of the SIV (116) and the PV (118), after a time delay. The controller compares a delta pressure between the first pressure and the second pressure with a threshold pressure, and determine leakage in the HIPR (104) based on the result of the comparison.

Description

Title of the invention: A DEVICE TO DETERMINE PRESSURE LEAKAGE IN A HYDROGEN INJECTION PRESSURE REGULATOR AND METHOD THEREOFField of the invention:

[0001] The present invention relates to a device to determine pressure leakage in a hydrogen injection pressure regulator and method thereof.Background of the invention:

[0002] According to a prior art CN216520969, a leakage rate testing system of hydrogen-doped natural gas pressure regulator is disclosed. The prior art discloses the leakage rate test system of a hydrogen-doped natural gas pressure regulator. A hydrogen cylinder, a second branch gas circuit used for connecting a methane gas cylinder, a first branch gas circuit used for connecting a nitrogen gas cylinder, a gas mixing tank, a tested pressure regulator, a hydrogen concentration detector and a methane concentration detector are sequentially connected to a main gas circuit. Compared with the prior art, the hydrogen-doped natural gas pressure regulator leakage rate testing device has the following remarkable technical effects: 1, the hydrogen-doped natural gas pressure regulator leakage rate testing device can test respective leakage rates of hydrogen and methane gas in a gas pressure regulator, is accurate in testing, and can ensure the use safety of a hydrogen-doped natural gas pressure regulator; 2, the device is convenient to use, and different hydrogen doping requirements can be met by adjusting the hydrogen doping proportion; and 3, the device is simple in structural composition, low in cost, high in practicability and suitable for being widely popularized and used.Brief description of the accompanying drawings:

[0003] An embodiment of the disclosure is described with reference to the following accompanying drawings,

[0004] Fig. 1 illustrates a block diagram of a device to determine leakage of a Hydrogen Injection Pressure Regulator (HIPR) in a hydrogen fuel injection system of a vehicle, according to an embodiment of the present invention, and

[0005] Fig. 2 illustrates a method for determining leakage of the HIPR in the hydrogen fuel injection system of the vehicle, according to the present invention.Detailed description of the embodiments:

[0006] Fig. 1 illustrates a block diagram of a device to determine leakage of a Hydrogen Injection Pressure Regulator (HIPR) in a hydrogen fuel injection system of a vehicle, according to an embodiment of the present invention. The fuel injection system 100 comprises a fuel flow path connecting a storage tank 102 to a fuel injector 108. The fuel injector 108 injects fuel which is combusted inside a combustion chamber of an engine. In a hydrogen based internal combustion engine (H2ICE), the hydrogen fuel is stored in high pressure (in form of gas) in storage tank 102 and supplied to the combustion chamber of the engine by regulating the pressure using HIPR 104 and accumulating the gas in fuel rail 106 with reduced pressure (lesser than pressure in the storage tank 102) and injected into the combustion chamber through Hydrogen Gas Injector (HGI) or fuel injector 108, for accurate injection which helps for proper combustion. The dotted line connecting the storage tank 102 to the HIPR 104 indicates that there are many other components in between which are omitted here for the sake of simplicity such as pressure sensors, filters and the like, but the same must not be understood in limiting manner. The fuel rail 106 is installed with temperature sensor and a pressure sensor. The HIPR 104 is also installed with the pressure sensor 122.

[0007] The HIPR 104 is a unit comprising a System Isolation Valve (SIV) 116, the medium pressure sensor 122 and a Proportional Valve (PV) 118. The SIV 116 is the inlet towards the storage tank 102, and the PV 118 is the outlet of HIPR 104 connecting to the fuel rail 106. The PV 118 is responsible for controlling the mass flow to maintain the required rail pressure in the fuel rail 106. The HIPR 104 comprises separate components combined as a unit, and hence there are severaljoints. The hydrogen atoms are smaller in nature, and there are high chances of hydrogen gas escaping through joints into engine cabin. Because of such leakage, the performance of the engine is affected and there are possibilities of explosion through external trigger.

[0008] According to the present invention, the device 120 to determine pressure leakage in a Hydrogen Injection Pressure Regulator (HIPR) 104 is disclosed. The HIPR 104 comprises the System Isolation Valve (SIV) 116 at inlet and the proportional Valve (PV) 118 at outlet. The device 120 comprises a controller, characterized in that, the controller configured to close the SIV 116 and the PV 118, measure a first pressure inside the HIPR 104 using the mounted pressure sensor 122 at a first time instant of closure of the SIV 116 and the PV 118. The controller further measures a second pressure inside the HIPR 104 at a second time instant before opening of at least one of the SIV 116 and the PV 118, after a time delay. In other words, the second pressure is the pressure measured just before opening the SIV 116 and the PV 118. The controller compares a delta pressure between the first pressure and the second pressure with a threshold pressure, and determine leakage in the HIPR 104 based on the result of the comparison. The delta pressure is the difference between the first pressure and the second pressure.

[0009] According to an embodiment of the present invention, the threshold pressure comprises a first threshold and a second threshold. The leakage is determined to be absent if the delta pressure is less than the first threshold. Similarly, the leakage is determined to be present if the delta pressure is greater than the second pressure. Alternatively, a single threshold value is used to decide the leakage status of the HIPR 104.

[0010] In accordance to an embodiment, the controller determines the leakage during an engine overrun condition. The time delay is any one of duration of the engine overrun condition or a time interval within the engine overrun condition. The time interval defines the necessary time within which the pressure reduction inthe HIPR 104 is expected. The time interval is calibratable as per requirement. During engine over-run (when vehicle is running and accelerator is released and for some time vehicle has its own momentum to move with gear engaged), the engine is driven by the wheels with no fuel injected. When there are no injections, there is no fuel flow to the rail needed. So the SIV 116 and the PV 118 are closed as long as the engine overrun condition exists. With both valves closed, the HIPR 104 is a closed space where ideally no gas can escape, and the controller is configured to initiate the process of determination of the leakage in this condition.

[0011] According to an embodiment of the present invention, the device 120 is at least one of an internal device and an external device. The internal device is an existing control unit of the vehicle, and the external device is at least one of a portable device 126 (or communication device) and a cloud based device 128 (or cloud or server). The internal device is at least one Electronic Control Unit (ECU) 110 selected from a group comprising is at least one of an Engine Management System (EMS) controller, a Telematics Control Unit (TCU) controller, or other existing control units within the vehicle and a combination thereof. The external device is at least one of the portable device 126 and the cloud based device 128. The external device is connected through a Telematic Control Unit (TCU) of the vehicle through at least one a wired and wireless means known in the art, such as Universal Serial Bus (USB), micro USB, Bluetooth™, etc. The portable device 126 corresponds to electronic computing devices which enable a rider or driver or a user to communicate with others such as smartphone, wearable electronics such as smart watch, smart ring, etc. The cloud based device 128 corresponds to cloud computing architecture having network of servers, databases connected with each other and vehicle for processing of inputs and providing outputs.

[0012] According to an embodiment of the present invention, the device 120 is implementable in different manners or scenarios. In a first scenario, the device 120 is just the ECU 110 of the vehicle. Thus, the determination of the leakage in HIPR 104 is directly done by the ECU 110 of the vehicle. In a second scenario, the device120 is the external device, i.e. at least one of the portable device 126 and the cloud based device 128. The input signals, comprising the measured fist pressure and the second pressure, are transmitted to the portable device 126 and the cloud based device 128 through the TCU through wired or wireless means as known in the art. In a third scenario, the device 120 is combination of the internal device and external device, i.e. the device 120 is combination of the ECU 110 and the portable device 126, or combination of the ECU 110 and the cloud based device 128 or combination of the portable device 126 and the cloud based device 128 or the combination of the ECU 110, the portable device 126 and the cloud based device 128. The second scenario and the third scenario are explained later.

[0013] The device 120 which is at least one of the ECU 110 or controller, the portable device 126, and the cloud based device 128 and refers to computing devices / units comprising components such as memory element 112 such as Random Access Memory (RAM) and / or Read Only Memory (ROM), Analog-to- Digital Converter (ADC), Digital-to-Analog Convertor (DAC), clocks, timers and a processor (such as Central Processing Unit (CPU)) (capable of implementing machine learning) connected with the each other and to other components through communication bus channels. The components mentioned are just for understanding and may have more or less components as per requirement. The memory element 112 of the device 120 is prestored with map, table, pressure evaluation model 114, modules, logics, instructions, programs, applications, or threshold values (first threshold, second threshold), which is accessed by the at least one processor as per the defined routines. The internal components of the controller are not explained for being state of the art, and the same must not be understood in a limiting manner. The device 120 is capable to communicate through wired and wireless means such as but not limited to Global System for Mobile Communications (GSM), 3G, 4G, 5G, Wi-Fi, Bluetooth, Ethernet, serial networks, Universal Serial Bus (USB) cable, micro-USB, and the like.

[0014] Further, the processor may be implemented as any or a combination of one or more microchips or integrated circuits interconnected using a parent board, hardwired logic, software stored in the memory element 112 and executed by a microprocessor, firmware, an application specific integrated circuit (ASIC), and / or a field programmable gate array (FPGA). The processor is configured to exchange and manage the processing of various Artificial Intelligence (Al) modules.

[0015] In accordance to an embodiment of the present invention and as per the second scenario, the device 120 is the external device, i.e. any one of the portable device 126 (or communication device) and the cloud based device 128. For ease of understanding, the device 120 is now explained as the cloud based device 128, but the same explanation is applicable when the external device is the portable device 126. When the device 120 is the cloud based device 128, the cloud based device 128 receives the input comprising the measured first pressure and the second pressure, directly from the ECU 110. The ECU 110 does not process the input signals and directly transmits the input signal to the cloud based device 128 through the TCU or through the portable device 126. The cloud based device 128 is configured to receive the input signals from the ECU 110 and determines the leakage using a pressure evaluation model 114. The cloud based device 128 then triggers an alert to concerned user and indicates the leakage status of the HIPR 104. Alternatively, the cloud based device 128 sends the determined leakage status to the ECU 110 of the vehicle which is displayed on a dashboard (instrument cluster) of the vehicle.

[0016] Similarly, when the device 120 is the portable device 126, the portable device 126 is connected to the ECU 110 through suitable communication or networking means as described before, such as but not limited to Bluetooth™, WiFi, Universal Serial Bus (USB) cables, etc. The application installed in the portable device 126 processes the input signals received from the ECU 110 and sends back the leakage status. The application stores the result internally for later reference.

[0017] In accordance to an embodiment of the present invention and as per the third scenario, the device 120 is combination of internal device (the ECU 110) and the external device. The processing of the input signals is shared among the internal device(s) and the external device(s), and the output is finally performed in the vehicle. For example, consider the device 120 as combination of the ECU 110 and the cloud based device 128. The ECU 110 pre-processes the input parameters (calculating the delta pressure) and sends the delta pressure to the cloud based device 128 for determination of leakage. Thus, the cloud based device 128 performs fewer steps and sends back the leakage status to the vehicle or user.

[0018] Further, the vehicle is any one selected from a group comprising a twowheeler such as scooter, motorcycle, and a three-wheeler such as autorickshaw, four wheeler such as cars, multi-wheeler vehicles such as busses, trucks Off- Highway vehicles. Specifically, the vehicle is either internal combustion engine based or hybrid vehicle.

[0019] According to the present invention, a principle and working of the device 120 is explained. To determine whether there is leakage in the HIPR 104 or not, the pressure holding / withstanding capability of the HIPR 104 needs to be checked. To measure the pressure withstanding capacity, a certain known pressure must be built up inside the HIPR 104 and the inlet (SIV) 116 and the outlet (PV) 118 of HIPR 104 must be closed. The HIPR 104 must remain like this for a certain time (t), and it is checked whether the HIPR 104 holds the same pressure at the end of the time t. A normal HIPR 104 holds the pressure with zero or a negligible pressure drop, whereas the abnormal HIPR 104 fails to withstand the pressure and results in higher pressure drop.

[0020] While the engine is OFF, there is no gas present inside the HIPR 104 since the gaseous fuel is burned out during previous engine shut-off. While the engine is running, the pressure inside the HIPR 104 varies and the SIV 116 is full open, and PV 118 is opened and closed frequently based on the engine load. But to confirmthe leakage in the HIPR 104, the SIV 116 and the PV 118 should be closed for a specific period of time (t) with some amount of gas pressure inside HIPR 104. Such a scenario is made possible during the engine overrun condition. So when the engine overrun condition occurs, with a known pressure inside the HIPR 104 at an initial time to, the first pressure (Pi) is measured and recorded by the controller. The same pressure or some amount negligible pressure reduction (P2) is expected after some interval of time ti, for the ideal HIPR 104 and is measured and recorded by the controller. In case of the faulty or abnormal HIPR 104, the gas escapes and the pressure drops significantly. By taking pressure difference (AP) between the first pressure (initial pressure) and the second pressure (subsequent pressure), the controller is able to differentiate the normal HIPR 104 from the abnormal HIPR 104.

[0021] During engine overrun (when vehicle is running and accelerator is released and for some time vehicle has its own momentum to move with gear engaged), the engine is driven by the wheels with no fuel injected. When there are no injections, there is no fuel flow to the rail needed. So the SIV 116 and the PV 118 are closed as long as the engine over-run exists. With both valves closed, the HIPR 104 is a closed space where ideally no gas can escape. Hence, first the controller detects and determines the presence of the engine overrun condition using the accelerator input and the vehicle speed. Now the controller captures / measures the first pressure (Pi) in the HIPR 104, using the pressure sensor 122, as soon as the SIV 116 and the PV 118 are closed. As long as the engine overrun exists, the values of the second pressure (P2) are captured in regular intervals by the controller. When engine overrun phase ends, as detected by the controller, and the SIV 116 or the PV 118 are open for normal engine running, the controller configured to measure the recent pressure (second pressure) value (P2) before valves opening moment by the same pressure sensor 122 and stores in the memory element 112.

[0022] After the certain duration t, i.e. (ti - to), the controller calculates the AP between Pi and P2, which gives amount of pressure reduction in the HIPR 104. TheAP is compared against certain thresholds Pmax(t) to decide the leakage of the HIPR 104 as normal or leaky and take further actions such as service or replacement or alert.

[0023] An example calculation of pressure evaluation is described below for clarity and the same must not be understood in limiting sense.Consider the first pressure in the HIPR 104 right after the SIV 116 and the PV 118 are closed at to is Pi.Similarly, consider the second pressure in the HIPR 104, just before the SIV 116 or the PV 118 are opened at ti is P2.Thus, delta pressure is AP = Pl - P2AP< Pmin(t), means pressure almost stable and the HIPR 104 is normal and can be continued with usage.AP > Pmax(t), means pressure drop happened and the HIPR 104 is leaky and must be replaced.Since leaking of hydrogen above some extent (theoretical volumetric ratio of 4% to 75% of atmospheric air) leads to ignition, the Pmax(t) is set less than the extent. The Pmin(t) and Pmax(t) are the two threshold values used by the controller.

[0024] According to the present invention, the working of the device 120 is also explained using a graph 130. The graph 130 shows multiple plots for ease of understanding with x-axis 132 representing time in suitable units and y-axis representing multiple variables with respective units as defined below. A first plot 136 shows the accelerator position, a second plot 138 shows a state of the SIV 116, a third plot 140 shows the status of the PV 118 and a fourth plot 142 shows the reading from the pressure sensor 122. The controller operates in the background checking for the engine overrun condition to occur / happen. Once the engine overrun starts, at to, the controller ensures the SIV 116 and the PV 118 in closed position. At time instant to, the accelerator is shown in released position, and the SIV 116 and the PV 118 are in closed state. The controller then measures the second pressure at ti, which is either the end of engine overrun condition or a predeterminedtime as configured before the end of the engine overrun condition. Then the controller monitors the pressure at HIPR 104 and differentiates the pressure signal pattern for the normal HIPR 104 (Solid line in fourth plot 142) and the leaky HIPR 104 (Dotted line in fourth plot 142) based on the AP and outputs the result 124. The controller makes use of pressure evaluation model 114 to determine and compare the leakage.

[0025] According to the present invention, the device 120 to determine pressure leakage in a Hydrogen Injection Pressure Regulator (HIPR) 104 is disclosed. The HIPR 104 comprises the System Isolation Valve (SIV) 116 at inlet and the proportional Valve (PV) 118 at outlet. The device 120 comprises the controller, characterized in that, the controller configured to detect engine overrun condition, and close the SIV 116 and the PV 118 once the engine overrun condition is detected. The controller measures the first pressure inside the HIPR 104 using the mounted pressure sensor 122 at the first time instant of closure of the SIV 116 and the PV 118. The controller further measures the second pressure inside the HIPR 104 at the second time instant before opening of the SIV 116 and the PV 118 after the time delay. In other words, the second pressure is the pressure measured just before opening the SIV 116 and the PV 118. The controller compares the delta pressure between the first pressure and the second pressure with the threshold pressure, and determines leakage in the HIPR 104 based on the result of the comparison. The delta pressure is the difference between the first pressure and the second pressure.

[0026] Fig. 2 illustrates a method for determining leakage of the HIPR in the hydrogen fuel injection system of the vehicle, according to the present invention. The HIPR 104 comprises the System Isolation Valve (SIV) 116 at inlet and the proportional Valve (PV) 118 at outlet. The method is characterized by plurality of steps of which a step 202 comprises closing the SIV 116 and the PV 118. A step 204 comprises measuring the first pressure inside the HIPR 104 using the mounted pressure sensor 122 at the first time instant of closing the SIV 116 and the PV 118. A step 206 comprises measuring the second pressure inside the HIPR 104 at thesecond time instant before opening the SIV 116 or the PV 118 after the time delay. A step 208 comprises comparing the delta pressure between the first pressure and the second pressure with the threshold pressure. A step 210 comprises determining leakage in the HIPR 104 based on the result of the comparison.

[0027] According to the method, the threshold pressure comprises the first pressure and the second pressure. The leakage is determined to be absent if the delta pressure is less than the first pressure, and the leakage is determined to be present if the delta pressure is greater than the second pressure. The method comprises determining the leakage during the engine overrun condition. The time delay is any one of duration of the engine overrun condition or the time interval within the engine overrun condition. The time interval defines the necessary time within which the pressure reduction in the HIPR 104 is expected. The time interval is calibratable as per requirement.

[0028] According to the present invention, the method is performed by at least one of the internal device and the external device. The internal device is the existing control unit of the vehicle, and the external device is at least one of the portable device 126 and the cloud based device 128.

[0029] According to the present invention, a method for determining pressure leakage in the Hydrogen Injection Pressure Regulator (HIPR) 104 is disclosed. The HIPR 104 comprises the System Isolation Valve (SIV) 116 at inlet and the proportional Valve (PV) 118 at outlet. The method is characterized by plurality of steps of which a step 212 comprises detecting engine overrun condition. A step 214 comprises closing the SIV 116 and the PV 118 once the engine overrun condition is detected. A step 216 comprises measuring the first pressure inside the HIPR 104 using the mounted pressure sensor 122 at the first time instant of closure of the SIV 116 and the PV 118. A step 218 comprises measuring the second pressure inside the HIPR 104 at the second time instant before opening of the SIV 116 or the PV 118 after the time delay. A step 220 comprises comparing the delta pressurebetween the first pressure and the second pressure with the threshold pressure. A step 222 comprises determining leakage in the HIPR 104 based on the result of the comparison. The delta pressure is the difference between the first pressure and the second pressure.

[0030] According to the present invention, the device 120 and method to check the leakage in Hydrogen Injection Pressure Regulator (HIPR) 104 is disclosed. The present invention detects the leakage at the HIPR 104 and avoid hazardous situations such as explosion due to external triggers. The present invention provides prognostic solution for the HIPR 104.

[0031] It should be understood that the 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 device (120) to determine pressure leakage in a Hydrogen Injection Pressure Regulator (HIPR) (104), said HIPR (104) comprises a System Isolation Valve (SIV) (116) at inlet and a Proportional Valve (PV) (118) at outlet, said device (120) comprises a controller, characterized in that, said controller configured to, close said SIV (116) and said PV (118); measure a first pressure inside the HIPR (104) using a mounted pressure sensor (122) at a first time instant of closure of said SIV (116) and said PV (118); measure a second pressure inside said HIPR (104) at a second time instant before opening at least one of said SIV (116) and said PV (118) after a time delay; compare a delta pressure between said first pressure and said second pressure with a threshold pressure, and determine leakage in said HIPR (104) based on the result of said comparison.

2. The device (120) as claimed in claim 1, wherein said threshold pressure comprises a first threshold and a second threshold, wherein said leakage is determined to be absent if said delta pressure is less than said first threshold, and said leakage is determined to be present if said delta pressure is greater than said second threshold.

3. The device (120) as claimed in claim 1, wherein said controller determines said leakage during an engine overrun condition.

4. The device (120) as claimed in claim 1, wherein said time delay is any one of duration of an engine overrun condition or a time interval within said engine overrun condition.

5. The device (120) as claimed in claim 1 is at least one of an internal device and an external device, wherein said internal device is an existing control unit of said vehicle and said external device is at least one of a portable device (126) and a cloud based device (128).

6. A method for determining pressure leakage in a Hydrogen Injection Pressure Regulator (HIPR) (104), said HIPR (104) comprises a System Isolation Valve (SIV) (116) at inlet and a Proportional Valve (PV) (118) at outlet, characterized by, said method comprising the steps of, closing said SIV (116) and said PV (118); measuring a first pressure inside said HIPR (104) using a mounted pressure sensor (122) at a first time instant of closing said SIV (116) and said PV (118); measuring a second pressure inside said HIPR (104) at a second time instant before opening at least one of said SIV (116) and said PV (118) after a time delay; comparing a delta pressure between said first pressure and said second pressure with a threshold pressure, and determining leakage in said HIPR (104) based on the result of said comparison.

7. The method as claimed in claim 6, wherein said threshold pressure comprises a first pressure and a second pressure, wherein said leakage is determined to be absent if said delta pressure is less than first pressure, and said leakage is determined to be present if said delta pressure is greater than said second pressure.

8. The method as claimed in claim 6, wherein said leakage is determined during an engine overrun condition.

9. The method as claimed in claim 6, wherein said time delay is any one of duration of an engine overrun condition or a time interval within said engine overrun condition.

10. The method as claimed in claim 6 is performed by at least one of an internal device and an external device, wherein said internal device is an existing control unit of said vehicle and said external device is at least one of a portable device (126) and a cloud based device (128).

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