Method and apparatus for determining the amount of fuel in a pressure vessel

Abstract

The technology disclosed herein relates to a device (101) for determining quantity information regarding the amount of fuel in a pressure vessel (110) of a pressure vessel system (100), in which the pressure vessel system (100) is configured to guide fuel from the pressure vessel (110) to an energy converter (102) via a pressure transducer (120). The pressure vessel system (100) has low-pressure sensors (122, 203) on the low-pressure side of the pressure transducer (120). The device (101) is configured to determine a measurement of the pressure on the low-pressure side based on the low-pressure sensors (122, 203), and to determine quantity information regarding the amount of fuel in the pressure vessel (110) based on the measurement of the low-pressure sensors (122, 203).

Description

Technical Field

[0001] The technology disclosed in this specification relates to a method and a corresponding device that are adapted to determine the fuel quantity in a pressure vessel, and in particular to predict the remaining driving range of a vehicle based on this fuel quantity.

[0002] A road vehicle can have a fuel cell stack that generates electrical energy for vehicle operation, particularly for driving, based on a fuel such as hydrogen. The fuel can be stored in one or more pressure vessels of the vehicle's pressure vessel system and can be supplied to the fuel cell stack via pipelines as needed.

[0003] The pressure vessel system typically includes a pressure sensor configured to capture measurement values related to the fuel pressure within the pressure vessel system. Based on these measurement values, the fuel quantity in one or more pressure vessels of the pressure vessel system can be determined, and based on the determined fuel quantity, the remaining driving range of the vehicle can be predicted.

[0004] One or more pressure vessels and pressure sensors of the pressure vessel system may each be configured for a rated pressure of 350 barue or more, or 700 barue or more. The measurement error of the pressure sensor typically scales with the rated pressure for which the pressure sensor is designed (e.g., 1 - 2% of the rated pressure or full-scale pressure). Thus, the measurement value of the pressure sensor can have a measurement error of 10 - 20 bar. This can lead to the possibility that in situations where the fuel pressure is relatively low and the fuel quantity is relatively small, it is only possible to determine the remaining fuel quantity in the pressure vessel with relatively low accuracy, and as a result, the remaining driving range of the vehicle can only be determined with relatively low accuracy.

[0005] One preferred problem of the technologies disclosed herein is to reduce or eliminate at least one drawback of a previously known solution, or to propose an alternative solution. Another preferred problem of the technologies disclosed herein is to enable efficient and accurate determination of the amount of fuel in the pressure vessel of a pressure vessel system.

[0006] The above problems are solved by the subject matter of the independent claim. A preferred configuration is shown in the dependent claim.

[0007] In one embodiment, a device for determining quantity information relating to the amount of fuel in a pressure vessel of a pressure vessel system is described. Alternatively or supplementarily, the device may be designed to determine the fuel pressure in the pressure vessel, in which case this fuel pressure can be used to determine quantity information (for example, based on a predetermined model). This quantity information can be used to determine or estimate the driving range of a vehicle powered by fuel from the pressure vessel.

[0008] A pressure vessel system may include one or more pressure vessels for storing fuel (particularly hydrogen, e.g., H2, or compressed natural gas (CNG)). The pressure vessel system may be part of a higher-level system (e.g., a vehicle). This higher-level system may include an energy converter tuned to generate electrical energy for its operation based on the fuel from the pressure vessel system. In a preferred example, the higher-level system is an automobile (e.g., a passenger car, a truck, a motorcycle, a bus, etc.).

[0009] Pressure vessel systems can be used, in particular, for storing gaseous fuels under environmental conditions. For example, pressure vessel systems can be used in vehicles that operate on compressed natural gas (also known as CNG), liquefied natural gas (also known as LNG), or hydrogen (especially H2) as fuel. A pressure vessel system is typically in fluid communication with at least one energy converter tuned to convert the chemical energy of the fuel into one or more other energy forms. The energy converter may include a fuel cell or a fuel cell stack.

[0010] A pressure vessel system typically includes at least one pressure vessel, particularly a composite overwrapped pressure vessel. The pressure vessel may be, for example, a cryogenic pressure vessel or a high-pressure gas vessel.

[0011] High-pressure gas containers are configured to permanently store fuel at ambient temperature at a nominal working pressure (also known as NWP) of at least 350 bar (overpressure relative to atmospheric pressure) or at least 700 bar. Cryogenic pressure containers are suitable for storing fuel at temperatures significantly lower than the operating temperature of an automobile (e.g., above 50 Kelvin or above 100 Kelvin) at the aforementioned working pressures.

[0012] The pressure vessel system includes, for example, a pipeline configured to guide fuel from the pressure vessel to an energy converter via a pressure transducer (particularly via a pressure controller). The energy converter is tuned to convert the chemical energy of the fuel into one or more other energy forms, such as electrical energy and / or kinetic energy. The energy converter may be, for example, an internal combustion engine or a fuel cell system or a fuel cell stack comprising at least one fuel cell.

[0013] The pressure transducer may be configured to reduce the fuel pressure. The input side of the pressure transducer may have a high-pressure side (between the pressure vessel and the pressure transducer) designed for the relatively high fuel pressure of the pressure vessel.

[0014] A pressure transducer may have one or more transducer stages to reduce fuel pressure. In this case, a low-pressure side may be located on the output side of one or more transducer stages, and this low-pressure side is designed for fuel pressures lower than the possible pressure (i.e., rated pressure) on the high-pressure side. Thus, the low-pressure side may be located on the output side of a first transducer stage or on the output side of a second transducer stage. In particular, the low-pressure side may be located on the side of the transducer stage of the pressure transducer that is opposite to the high-pressure side.

[0015] A pressure transducer, particularly the transducer stage of the pressure transducer, may be configured to set the fuel pressure to a predetermined target pressure on the low-pressure side of the output side of the pressure transducer (particularly the output side of the transducer stage), particularly by opening and closing a valve and / or by changing the valve opening. For example, the valve opening of the pressure transducer can be changed in a continuous manner between 0% and 100%. This opening can be increased when the actual pressure (i.e., the actual value of the pressure) on the output side of the pressure transducer is less than the target pressure. On the other hand, the opening can be decreased when the actual pressure on the output side of the pressure transducer is less than the target pressure. In this case, the target pressure may be less than the rated pressure of the pressure vessel (designed for the high-pressure side), and may be at least twice as low.

[0016] This pressure vessel system has a low-pressure sensor on the low-pressure side of the pressure transducer (i.e., on the side of the pressure transducer opposite to the high-pressure side and / or the pressure vessel). This low-pressure sensor may be designed for the target pressure on the low-pressure side.

[0017] Furthermore, the pressure vessel system may have a high-pressure sensor on the high-pressure side (between the pressure vessel and the input side of the pressure transducer). This high-pressure sensor may be configured for the rated pressure of the pressure vessel.

[0018] This device is configured to obtain a measurement of the pressure on the low-pressure side based on a low-pressure sensor. This measurement can be captured at a specific time point, at which time one or more measurement conditions may be met.

[0019] This device is further configured to determine quantity information regarding the amount of fuel in the pressure vessel based on measurements from a low-pressure sensor.

[0020] Therefore, low-pressure sensors (which have relatively low absolute measurement errors) can be used to determine the pressure inside a pressure vessel.

[0021] The amount of fuel in a pressure vessel can be determined based on the pressure inside the vessel. Therefore, the amount of fuel can be determined efficiently and accurately.

[0022] This device may be adjusted to detect a measurement point in time when the pressure on the high-pressure side (between the pressure vessel and the pressure transducer) corresponds to the pressure on the low-pressure side. For this purpose, the duration of time since the valve of the pressure transducer (which connects the high-pressure side to the low-pressure side or disconnects it from the low-pressure side) was permanently (completely) open can be determined.

[0023] Alternatively or supplementarily, the low-pressure sensor readings can be repeatedly determined. Furthermore, each individual reading can be checked to see whether it is above or below the target pressure for the low-pressure side. Then, the duration for which the low-pressure sensor reading remains below the target pressure (and thus can be considered as the starting point for the pressure transducer valve being fully open) can be determined.

[0024] Subsequently, based on the determined duration, it can be specified that the pressure on the high-pressure side corresponds to the pressure on the low-pressure side (and thus the measurement time point exists). Alternatively or additionally, in order to identify that the pressure on the high-pressure side corresponds to the pressure on the low-pressure side, the time course of the measured value of the low-pressure sensor when the valve of the pressure transducer is opened can be analyzed.

[0025] Subsequently, the measured value of the low-pressure sensor can be obtained or captured at the detected measurement time point and used to obtain quantity information. In this way, the quantity information can be obtained in a particularly accurate form.

[0026] For one equilibration period, the device - causes the valve of the pressure vessel to be closed, thereby preventing fuel from reaching the high-pressure side (of the pipeline) from the pressure vessel, - may be adjusted by the energy converter to cause fuel from the low-pressure side (of the pipeline) to be consumed.

[0027] This operation can be caused until a measurement time point is detected at which the pressure on the high-pressure side corresponds to the pressure on the low-pressure side.

[0028] Therefore, during the operation period of the pressure vessel system, equilibration between the pressure on the high-pressure side and the pressure on the low-pressure side can be caused (exclusively). Thereby, the measurement conditions for capturing the measured value of the low-pressure sensor can be satisfied in a particularly flexible form.

[0029] The device may be adjusted to obtain an offset value for correcting the measurement error of the high-pressure sensor based on the measured value obtained at the measurement time point of the low-pressure sensor (in this case, the high-pressure sensor is arranged between the pressure vessel and the pressure transducer on the high-pressure side). The device may particularly be adjusted to obtain the measured value of the high-pressure sensor at the measurement time point. Therefore, the offset value can be obtained in a particularly accurate form by comparing the measured values of the low-pressure sensor and the high-pressure sensor at the measurement time point.

[0030] The device may further be adjusted to determine the measured value of the high-pressure sensor at one operating point during the operation of the pressure vessel system. In this case, the operating point may be different from the measurement point. Then, the quantity information regarding the fuel quantity in the pressure vessel at the operating point can be determined based on the measured value of the high-pressure sensor and the offset value in a particularly accurate format.

[0031] Therefore, the measured value of the low-pressure sensor (at the measurement point) can be used to obtain an offset value that can reduce the absolute measurement error of the high-pressure sensor. Thereby, the quantity information can be determined in a particularly accurate format.

[0032] The device may be adjusted to determine operating data regarding the operating conditions at the operating point and the measurement point, particularly operating data regarding the temperature of the pressure vessel system, particularly the temperature of the fuel in the pressure vessel system. The operating conditions can include the temperature at the high-pressure sensor and / or the low-pressure sensor. For example, the offset value may be obtained under a first operating condition (e.g., at a first temperature). At the operating point, there may also be a second operating condition (e.g., a second temperature) (which may be different from the first operating condition in some cases).

[0033] Based on the operating data, it can be determined whether the offset value obtained at the measurement point for the (first) operating condition can be used to determine the quantity information at the operating point (e.g., when the first and second operating conditions deviate from each other by less than a predetermined threshold). Alternatively or additionally, based on the operating data, it can be determined whether a new offset value can be obtained to determine the quantity information (e.g., when the first and second operating conditions deviate from each other by more than a predetermined threshold). Thereby, a particularly accurate calculation of the quantity information can be caused.

[0034] In some cases, one offset value can be determined for each of several different operating conditions. This allows for the acquisition and storage of characteristic data indicating the appropriate offset value for each of these different operating conditions. Then, at the time of operation, the appropriate offset value for the currently existing operating conditions can be selected from this characteristic data. This enables particularly accurate calculation of quantitative information.

[0035] The device may be configured to repeatedly identify or detect measurement points in time from which an offset value can be determined. The offset value can then be repeatedly updated (for each of the existing operating conditions, if applicable). The updated offset values ​​can then be used (for each of the existing operating conditions) to determine quantity information at each operating point. This allows for particularly accurate calculation of the quantity information.

[0036] The pressure transducer may have a first transducer stage adjusted to set the pressure at the output side of the first transducer stage to a first target pressure, in which case the first target pressure is less than, in particular, twice or more than, the rated pressure of the pressure vessel. Furthermore, the first target pressure may be higher than, in particular, twice or more than, the minimum required pressure of the pressure vessel (this first target pressure should not fall below the operating period of the pressure vessel system).

[0037] The pressure transducer may further include a second transducer stage that is adjusted to set the pressure at the output side of the second transducer stage to a second target pressure. In this case, the second target pressure may be smaller than the first target pressure.

[0038] The low-pressure sensor may be positioned between the first and second transducer stages. This allows quantitative information to be obtained in a particularly robust and flexible format. In particular, this way the measurement conditions for capturing the low-pressure sensor's readings can be met with high reliability.

[0039] The device may be adjusted to determine the time course of the low-pressure sensor measurement during the operation of the pressure vessel system (for example, at a measurement rate of 0.1 Hz or higher, or 1 Hz or higher). This time course may include the low-pressure sensor measurement for at least one open phase, during which the valve of the pressure transducer is open to connect the high-pressure side (of the pipeline) to the low-pressure side. The open phase may be, for example, a phase in which the valve of the pressure transducer has an opening greater than an opening threshold. The opening threshold may be, for example, 50% or more.

[0040] Next, quantitative information regarding the amount of fuel in the pressure vessel can be obtained, in a particularly accurate format, based on the time course of the low-pressure sensor's measurements, and especially based on the measurements relative to the open phase.

[0041] In a further embodiment, a pressure vessel system for automobiles is described in particular. This pressure vessel system includes the apparatus described herein.

[0042] In a further embodiment, this description refers to (road-driving) vehicles (in particular passenger cars or trucks or buses or motorcycles) that include the pressure vessel systems and / or apparatus described herein.

[0043] In a further embodiment, a method for determining quantity information regarding the amount of fuel in a pressure vessel of a pressure vessel system is described, in which the pressure vessel system is configured to guide fuel (e.g., via a pipeline) from the pressure vessel (located on the high-pressure side) to an energy converter (e.g., a fuel cell) via a pressure transducer. The pressure vessel system has a low-pressure sensor on the low-pressure side of the pressure transducer (e.g., located on the output side of the transducer stage of the pressure transducer).

[0044] This method includes the step of determining a measurement of the (fuel) pressure on the low-pressure side based on a low-pressure sensor. Furthermore, this method includes the step of determining quantity information regarding the amount of fuel in the pressure vessel based on the measurement from the low-pressure sensor.

[0045] In a further embodiment, a software (SW) program is described. This SW program is configurable to run on a processor and thereby perform the methods described herein.

[0046] In a further embodiment, a storage medium is described. This storage medium may contain a software program configured to run on a processor and thereby perform the methods described herein.

[0047] It should be noted that the methods, apparatus, and systems described herein can be used individually or in combination with other methods, apparatus, and systems described herein. Furthermore, all embodiments of the methods, apparatus, and systems described herein can be combined with each other in a wide variety of ways. In particular, the features of the claims can be combined with each other in a wide variety of ways. Moreover, features described in parentheses should be understood as optional features.

[0048] The present invention will be described in more detail below based on examples. [Brief explanation of the drawing]

[0049] [Figure 1] This is a diagram illustrating an exemplary pressure vessel system. [Figure 2] This diagram shows an example of a multi-stage pressure controller. [Figure 3] This diagram shows a flowchart illustrating an exemplary method for determining quantity information regarding the amount of fuel in a pressure vessel.

[0050] As explained at the beginning, this specification relates to efficiently and accurately determining the amount of fuel in the pressure vessel of a pressure vessel system. In this regard, Figure 1 shows an exemplary pressure vessel system 100 having a pressure vessel 110 that can be used to provide fuel (in particular hydrogen, e.g., H2) for an energy converter (e.g., a fuel cell or fuel cell stack) 102. The pressure vessel 110 is connected to the energy converter 102 via a conduit 112. The pressure vessel 110 may have a valve 111 that can selectively guide fuel from the pressure vessel 110 to the conduit 112.

[0051] The fuel pressure in the pressure vessel 110 may be relatively high, and in particular may be 500 barue or higher, in order to accommodate as much fuel as possible within the pressure vessel 110. On the other hand, the energy converter 102 can operate with fuel at a relatively low pressure (e.g., 20 barue or less). Therefore, the fuel pipeline 112 between the pressure vessel 110 and the energy converter 102 may have a high-pressure side and a low-pressure side that communicate with each other via the pressure converter 120.

[0052] The fuel pressure on the high-pressure side (between the pressure vessel 110 and the pressure transducer 120) can be captured by the high-pressure sensor 121, and the fuel pressure on the low-pressure side (between the pressure transducer 120 and the energy transducer 102) can be captured by the low-pressure sensor 122. The high-pressure sensor 121 is configured for at least the rated pressure of the pressure vessel 110, for example, 500 barue or more or 800 barue or more. The low-pressure sensor 122 is configured for the rated pressure of the energy transducer 102, for example, 30 barue or less. As explained at the beginning, the pressure sensors 121 and 122 typically have a measurement error proportional to the rated pressure of the pressure sensors 121 and 122. As a result, the low-pressure sensor 122 typically has a much smaller (absolute) measurement error (e.g., 10 times smaller (absolute) measurement error) than the high-pressure sensor 121.

[0053] The pressure vessel system 100 may have a (control) device 101 configured to drive and control the valve 111 of the pressure vessel 110 and / or to capture or obtain measurements from pressure sensors 121, 122. Furthermore, the device 101 may be configured to obtain quantity information regarding the amount of fuel in the pressure vessel 110 based on measurements from one or more pressure sensors 121, 122. For this purpose, the device 101 may use predetermined characteristic data and / or predetermined characteristic formulas (and possibly analytical formulas) that enable the determination of the amount of fuel in the pressure vessel 110 based on the fuel pressure in the pressure vessel 110 (and optionally based on one or more further measured quantities, such as fuel temperature).

[0054] The device 101 may be configured to take into account one or more measurements from the low-pressure sensor 122 when determining the amount of fuel in the pressure vessel 110, particularly when the pressure vessel 110 is at a relatively low pressure. This improves the accuracy of the determined quantity information, especially when the pressure vessel 110 still has only a relatively small amount of fuel.

[0055] The pressure transducer 120 may be configured to control the pressure on the low-pressure side to a predetermined target value or target pressure. For this purpose, the valve of the pressure transducer 120 is openable and closable (in particular, fully openable or fully closed). In some cases, the opening degree of the valve of the pressure transducer 120 is (continuously) adjustable. Opening the valve allows fuel to flow from the high-pressure side to the low-pressure side, thereby increasing the pressure on the low-pressure side. In this case, the volumetric flow rate or mass flow rate of fuel through the valve of the pressure transducer 120 typically depends on the pressure on the high-pressure side and / or the pressure difference between the high-pressure side and the low-pressure side.

[0056] When the pressure on the low-pressure side falls below a predetermined lower pressure threshold (typically lower than the target pressure value or target pressure for the low-pressure side), the valve of the pressure transducer 120 is opened and / or the opening of the valve of the pressure transducer 120 can be increased, thereby allowing (more) fuel to flow from the high-pressure side through the pressure transducer 120 to the low-pressure side, which leads to a pressure increase on the low-pressure side and (typically) a pressure decrease on the high-pressure side. When the pressure on the low-pressure side rises above a predetermined upper pressure threshold (typically higher than the target pressure value or target pressure for the low-pressure side), the valve of the pressure transducer 120 is closed and / or the opening of the valve of the pressure transducer 120 is reduced, which leads to a reduction in the amount of fuel flowing from the high-pressure side through the pressure transducer 120 to the low-pressure side.

[0057] In an appropriate manner, the pressure on the low-pressure side can be set to a target pressure or target pressure by changing the opening of the valve of the pressure transducer 120. In this case, the pressure on the high-pressure side typically decreases and gradually approaches the pressure on the low-pressure side. From a certain point in time, the pressures on the high-pressure and low-pressure sides become equal, which typically leads to the valve of the pressure transducer 120 being permanently (fully) open (100% opening).

[0058] If the valve of the pressure transducer 120 is permanently (completely) open, and / or if the pressure on the high-pressure side is equal to the pressure on the low-pressure side, the measurement from the low-pressure sensor 122 can be used to determine the remaining fuel in the pressure vessel 110 with increased accuracy (compared to the measurement from the high-pressure sensor 121).

[0059] In particular, in such situations, the measurements of the low-pressure sensor 122 and the high-pressure sensor 121 can be compared to each other in order to determine an offset value for correcting the measurement of the high-pressure sensor 121. This offset value can indicate the (typically systematic) measurement error of the high-pressure sensor 121. If x1 is the measurement of the low-pressure sensor 122 and the maximum possible (absolute) measurement error of the low-pressure sensor 122 is Δ1, then it can be inferred that the actual pressure is in the value interval [x1-Δ1, x1-Δ1]. If x2 is the measurement of the high-pressure sensor 121 and the maximum possible (absolute) measurement error of the high-pressure sensor 121 is Δ2, then the actual pressure is in the value interval [x2-Δ2, x2-Δ2].

[0060] The offset value for correcting the measurement values ​​of the high-voltage sensor 121 can be determined based on a comparison between the value interval [x2-Δ2, x2-Δ2] and the value interval [x1-Δ1, x1-Δ1]. For this purpose, a (pre-determined) calculation rule can be used.

[0061] To enable the determination of an offset value even when the pressure inside the pressure vessel 110 is (in some cases significantly) higher than the target pressure value for the low-voltage side, the valve 111 of the pressure vessel 110 can be closed during the operation period of the pressure vessel system 100. This allows the pressure on the high-pressure side to be equalized to the pressure on the low-pressure side by opening the valve of the pressure transducer 120. As soon as these pressures are equalized, an offset value for the measurement of the high-pressure sensor 121 can be determined based on the measurement of the low-pressure sensor 122. This offset value can be stored in the memory unit of the pressure vessel system 100 and used to correct the measurement of the high-pressure sensor 121, thereby enabling the determination of quantity information regarding the amount of fuel inside the pressure vessel 110 with greater accuracy.

[0062] The pressure vessel 110 should, for example, be configured such that the pressure inside the pressure vessel 110 does not fall below a predetermined minimum pressure in order to avoid damage to the pressure vessel 110. The minimum pressure of the pressure vessel 110 can be within the range of the pressure target value relative to the low-pressure side, which means that during the operation period of the pressure vessel system 100, there will be no situation in which the pressure in the pressure vessel 110 corresponds to the pressure on the low-pressure side.

[0063] Figure 2 shows a multistage pressure transducer 120 equipped with a first transducer stage 201 (having a first valve), the first transducer stage configured to induce pressure adaptation from the high-pressure side to a first (or intermediate) low-pressure side. Furthermore, a second transducer stage 202 (having a second valve) of the pressure transducer 120 can induce pressure adaptation from the first low-pressure side to a further reduced second low-pressure side. The first low-pressure side may have a target pressure that is, for example, two or three times (e.g., 2 to 5 times) higher than the target pressure of the second low-pressure side.

[0064] The pressure transducer 120 may have an (additional) low-pressure sensor 203 on the first low-pressure side. Since the target pressure on the first low-pressure side is typically well above the minimum pressure of the pressure vessel 110, the readings from this (additional) low-pressure sensor 203 can be used to obtain quantitative information about the amount of fuel in the pressure vessel 110 in a reliable form (as further described above).

[0065] Alternatively or supplementally, the device 101 may be configured to use the time course of the measurement from the low-pressure sensor 122 to determine quantity information regarding the amount of fuel in the pressure vessel 110. This allows for the determination of the pressure value on the high-pressure side, and consequently the amount of fuel, in a particularly accurate form.

[0066] As explained at the beginning, in a fuel cell electric vehicle (FCEV), highly compressed gaseous hydrogen is stored in a pressure vessel 110. To increase the energy density, the gaseous hydrogen is compressed to a pressure of up to 875 bar and stored in the pressure vessel 110 as CGH2 (Compressed Gaseous Hydrogen). The amount stored and the resulting vehicle range can be determined based on pressure and temperature measurements of the stored gas. For pressure measurement, a pressure sensor 121 with a measurement range up to 900 bar (i.e., rated pressure) can be used. Due to the relatively wide medium temperature range and tolerances of the electronic components and / or mechanical manufacturing tolerances, this type of pressure sensor 121 typically has a measurement error of up to 1-2% of the rated pressure (i.e., full scale), which corresponds to an absolute measurement error of approximately ±20 bar. This measurement error should be taken into account in the vehicle operation strategy, particularly in range calculations and / or when considering withdrawal stops based on the "pressure vessel is empty" condition.

[0067] A Type IV pressure vessel 110 used as a CGH2 reservoir may consist of a plastic liner with full CFK (carbon fiber reinforced plastic) reinforcement. This type of pressure vessel 110 may require a minimum pressure throughout its lifespan that should not be lowered during operation. Here, the maximum possible measurement error of the high-pressure sensor 121 should be considered in the vehicle operation strategy to reliably avoid the pressure of the pressure vessel 110 falling below its minimum pressure.

[0068] To protect the pressure vessel 110 from falling below the minimum pressure, a previously known measurement error can be added to the measurement value of the high-pressure sensor 121 as a safety guarantee. This procedure can be linked to the early shutdown of the pressure vessel system 100 and to a relatively large amount of unusable fuel (especially mass) in the pressure vessel 110. As a result, the amount of usable fuel in the pressure vessel system 100, and consequently the vehicle's driving range, can be made dependent on the measurement error of the high-pressure sensor 121 of the pressure vessel system 100.

[0069] To improve the amount of fuel available in the pressure vessel system 100 and, consequently, the vehicle's driving range, the pressure in the pressure vessel 110 can be captured at relatively low pressures via pressure sensors 122, 203 connected downstream of the control stage (i.e., pressure transducer 120) (and possibly without the high-pressure sensor 121). The output pressure (i.e., control pressure) downstream of the control stage 120 is typically several times lower than the input pressure. Therefore, downstream of the control stage 120, the absolute value of the measurement error and the unavoidable saturation that adversely affects the calculated vehicle's driving range are substantially negligible.

[0070] A mechanical piston spring pressure controller can be used as the pressure transducer 120 or control stages 201, 202. This type of pressure transducer 120 may be configured to automatically compensate for pressure between the input pressure and the output pressure when the input pressure is lower than the control pressure (i.e., the target pressure). This allows for accuracy balancing between the measurement positions of the pressure sensors 121, 122 before and after the control stage 120 when the input pressure is below the control pressure. The control pressure here should be set to exceed the minimum pressure of the pressure vessel 110, taking into account the measurement error of the pressure sensor 122 downstream of the control stage 120.

[0071] This allows us to utilize the relatively small measurement error multiplier of the pressure sensor 122 (i.e., the intermediate or low-pressure sensor) on the output side of the pressure controller 120. In this case, the measured value of the intermediate-pressure sensor 122 can be used as the take-off stop criterion. The measured value of the high-pressure sensor 121 can be used for calculating the remaining range.

[0072] In the case of the two-stage pressure control unit 120 (see Figure 2), the basic characteristics of a two-stage controller are available. The first stage 201 controls the high pressure to, for example, a pressure of approximately 60-70 bar, and the second stage 202 controls it to the required control pressure (output pressure). By incorporating a pressure sensor 203 between the two control stages 201 and 202 (interstage), a measurement position for pressure measurement with reduced measurement error (compared to that of the high-pressure sensor 121) becomes available. For example, when comparing with a rated pressure of 1000 bar, a pressure sensor 203 with a rated pressure of 100 bar can be used, thus reducing the absolute measurement error by 10 times.

[0073] When the pressure inside the pressure vessel 110 is relatively low, the cruising range calculation can be performed based on the measurements of the additional pressure sensor 203, without falling below the minimum pressure of the pressure vessel 110. Furthermore, based on the achievement of the state where "the measured pressure of the additional pressure sensor 203 = the minimum tank pressure (including the error multiplier for the measurement error of the interstage pressure sensor 203)", the withdrawal stop can be predicted as intended.

[0074] Alternatively or supplementally, a balancing function from the high-pressure sensor 121 to the intermediate-pressure sensor 122 can be provided when the tank valve of the pressure vessel 110 is closed. In this case, this type of balancing function can be performed for the driving or stopping of the vehicle. The pressure upstream of the control stage 120 can be reduced to below the control pressure (output pressure) when the tank valve is closed. This control pressure may be the pressure when the valve of the pressure transducer 120 or transducer stages 201, 202 is opened. The pressure reduction can be caused by the desired extraction via the energy transducer 102. In this state, the control stage 120 is fully open (with a 100% opening), and the input pressure becomes equal to the output pressure.

[0075] In this state, the measurement value of the intermediate pressure sensor 122, including the maximum measurement error of the intermediate pressure sensor 122, can be used as the physical pressure for the high-pressure sensor 121. Since the measurement error of the high-pressure sensor 121 is a relatively constant offset error, this balancing allows the measurement accuracy in the 0-30 bar pressure range and the prevailing temperature conditions at this point to be increased to the pressure level of the high-pressure sensor 121.

[0076] To minimize pressure loss during the sensor equilibration period, the dynamic characteristics of the take-out mass flow rate can be restricted. After this equilibration procedure, the tank valve of the pressure vessel 110 can be opened again, and the dynamic characteristic restriction can be removed. The value of the equilibrated high-pressure sensor 121 can be used as a criterion for calculating the remaining range and stopping the take-out. Additionally, the value of the intermediate-pressure or low-pressure sensor 122 can also be used for validation. If the ambient temperature and / or medium temperature conditions change significantly during the equilibration procedure, the equilibration procedure can be repeated.

[0077] Figure 3 shows a flowchart of a method 300 (possibly computer-implemented) for obtaining quantity information regarding the amount of fuel in the pressure vessel 110 of the pressure vessel system 100. The pressure vessel system 100 includes a pipeline 112 configured to guide fuel from the pressure vessel 110 to the energy converter 102 (particularly the fuel cell stack) via a pressure transducer 120 (particularly the pressure controller). Furthermore, the pressure vessel system 100 includes low-pressure sensors 122,203 on the low-pressure side between the pressure transducer 120 (particularly the transducer stage 201 of the pressure transducer 120) and the energy converter 102. In addition, the pressure vessel system 100 may have a high-pressure sensor 121 on the high-pressure side between the pressure vessel 110 and the pressure transducer 120. The low-pressure sensors 122,203 have a rated pressure corresponding to, for example, the target pressure of the pressure transducer 120. The high-pressure sensor 121 may have a rated pressure corresponding to the rated pressure of the pressure vessel 110 (e.g., the maximum possible pressure).

[0078] The method 300 includes step 301 of determining a measurement of the pressure on the low-pressure side based on the low-pressure sensors 122,203. This measurement can be determined at a measurement time when one or more measurement conditions are met. An example measurement condition is that at the measurement time, the pressure on the high-pressure side corresponds to the pressure on the low-pressure side of the pressure transducer 120.

[0079] Method 300 further includes step 302 of determining quantity information regarding the amount of fuel in the pressure vessel 110 based on measurements from low-pressure sensors 122,203. Here, a predetermined model can be used that is configured to determine the amount of fuel in the pressure vessel 110 based on the pressure value in the pressure vessel 110. This quantity information can be used to trigger a cessation of fuel extraction from the pressure vessel 110.

[0080] By using one or more measurements from low-pressure sensors 122,203 to determine the pressure inside the pressure vessel 110, the pressure inside the pressure vessel 110 can be determined with relatively low measurement error, thereby enabling a relatively accurate determination of the fuel quantity. Based on this quantity information, for example, the remaining driving range of a vehicle operating on fuel from the pressure vessel 110 can be determined.

[0081] The present invention is not limited to the embodiments presented. In particular, it should be noted that these descriptions and drawings are merely illustrative and represent only the principles to be embodied in the proposed methods, apparatus, and systems. [Explanation of Symbols]

[0082] 100 Pressure Vessel Systems 101 (Control) device 102 Energy Converter 110 Pressure vessel 111 Pressure vessel valve 120 Pressure transducer 121,122 Pressure Sensor 201,202 Converter stage (pressure converter) 203 Pressure Sensor Methods for obtaining 300 quantitative information 301-302 Method Steps

Claims

1. A device (101) for obtaining quantity information regarding the amount of fuel in the pressure vessel (110) of a pressure vessel system (100), The pressure vessel system (100) is configured to guide fuel from the pressure vessel (110) to the energy converter (102) via the pressure transducer (120). The pressure vessel system (100) has low-pressure sensors (122, 203) on the low-pressure side of the pressure transducer (120), The aforementioned device (101) is Based on the low-pressure sensors (122, 203), a measurement value for the pressure on the low-pressure side is obtained. A device (101) is configured to obtain quantity information regarding the amount of fuel in the pressure vessel (110) based on the measured values ​​of the low-pressure sensors (122, 203).

2. The aforementioned device (101) is The measurement point in time is detected when the pressure on the high-pressure side between the pressure vessel (110) and the pressure transducer (120) corresponds to the pressure on the low-pressure side. The apparatus (101) according to claim 1, which is adjusted to obtain the measured values ​​of the low-pressure sensors (122, 203) at the aforementioned measurement time and to use them to obtain the aforementioned quantity information.

3. The aforementioned device (101) is Between the high-pressure side and the low-pressure side, determine the duration of time since the valve of the pressure transducer (120) was permanently opened, and especially since it was permanently and completely open. The apparatus (101) according to claim 2, which is adjusted to determine, depending on the duration determined, that the pressure on the high-pressure side corresponds to the pressure on the low-pressure side.

4. The apparatus (101) maintains the measurement time until, for one equilibration period, the pressure on the high-pressure side corresponds to the pressure on the low-pressure side. The valve (111) of the pressure vessel (110) is closed, thereby preventing fuel from reaching the high-pressure side from the pressure vessel (110). The apparatus (101) according to claim 2 or 3, wherein the energy converter (102) is adjusted to cause the fuel from the low-pressure side to be consumed.

5. The aforementioned device (101) is Based on the measured values ​​of the low-pressure sensors (122, 203) obtained at the time of measurement, an offset value is determined to correct the measurement error of the high-pressure sensor (121) located on the high-pressure side between the pressure vessel (110) and the pressure transducer (120). During the operation period of the pressure vessel system (100), particularly at an operating time different from the measurement time, the measurement value of the high-pressure sensor (121) is obtained, and The apparatus (101) according to any one of claims 1 to 4, wherein the quantity information relating to the amount of fuel in the pressure vessel (110) at the time of operation is adjusted to be determined based on the measured value of the high-pressure sensor (121) and the offset value.

6. The aforementioned device (101) is The measurement value of the high-voltage sensor (121) at the aforementioned measurement time is determined. The apparatus (101) according to claim 5, which is adjusted to determine the offset value by comparing the measured values ​​of the low-pressure sensor (122, 203) and the high-pressure sensor (121) at the aforementioned measurement time.

7. The aforementioned device (101) Obtain operational data regarding operating conditions, particularly the temperature of the pressure vessel system (100), and especially operational data regarding the temperature of the fuel inside the pressure vessel system (100) at the time of operation and the time of measurement. Based on the aforementioned operational data, Whether the offset value obtained at the time of measurement for the aforementioned operating conditions can be used to determine the quantity information at the time of operation, and / or Is it possible to determine a new offset value in order to obtain the aforementioned quantitative information? The apparatus (101) according to claim 5 or 6, which is adjusted to identify.

8. The pressure transducer (120) is configured to set the pressure of the low-pressure fuel on the output side of the pressure transducer (120) to a target pressure, particularly by changing the valve opening. The apparatus (101) according to any one of claims 1 to 7, wherein the target pressure is less than the rated pressure of the pressure vessel (110), and in particular less than twice as much.

9. The pressure transducer (120) is A first transducer stage (201) is adjusted to set the pressure on the output side of the first transducer stage (201) to a first target pressure, wherein the first target pressure is less than, in particular more than twice, the rated pressure of the pressure vessel (110), and in particular more than twice, the minimum required pressure of the pressure vessel (110). Apparatus (101) according to claim 8, comprising: a second transducer stage (202) adjusted to set the pressure on the output side of the second transducer stage (202) to a second target pressure, wherein the second target pressure is less than the first target pressure, and the low-pressure sensors (122, 203) are located between the first transducer stage (201) and the second transducer stage (202).

10. A method (300) for determining quantity information regarding the amount of fuel in the pressure vessel (110) of a pressure vessel system (100), The pressure vessel system (100) is configured to guide fuel from the pressure vessel (110) to the energy converter (102) via the pressure transducer (120), The pressure vessel system (100) has low-pressure sensors (122, 203) on the low-pressure side of the pressure transducer (120), The above method (300) is, The steps include (301) determining the measured value of the pressure on the low-pressure side based on the low-pressure sensors (122, 203), A method (300) comprising the step (302) of determining the amount information relating to the amount of fuel in the pressure vessel (110) based on the measured values ​​of the low-pressure sensors (122, 203).

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