Hydrogen engine tail gas measuring device and system and calibration method

Abstract

The invention belongs to the technical field of engine manufacturing, and discloses a hydrogen engine tail gas measuring device and system and a calibration method.The hydrogen engine tail gas measuring device comprises a tail gas measuring channel, electromagnetic valve assemblies and measuring equipment, the tail gas measuring channel is of an approximately-U-shaped tubular structure, and the electromagnetic valve assemblies are fixedly connected to pipe openings in the two ends of the tail gas measuring channel in an openable and closable mode; the measuring equipment is fixedly connected to the middle of the tail gas measuring channel. According to the calibration method, the gas concentration component in the tail gas is accurately measured, the ECU rapidly adjusts the air-fuel ratio to reach the preset value according to the measurement result, the calibration speed is high, and the calibration principle is simple; the used measuring device is simple in structure and low in cost; the measured tail gas is discharged into a supercharger, and the engine power is ensured; the measuring device is connected with a plurality of measuring devices, other measurements can be completed while calibration is carried out, and the measuring cost is saved.

Description

Technical Field

[0001] The present invention belongs to the technical field of engine manufacturing, and in particular relates to a hydrogen engine exhaust gas measuring device, system and calibration method. Background Art

[0002] Hydrogen engines, internal combustion engines fueled by hydrogen, offer unique characteristics and advantages, but also present challenges. During hydrogen engine development, detonation or misfire in a particular cylinder can be a problem. This requires testing the exhaust composition of individual cylinders to precisely control each cylinder and achieve efficient engine operation. Hydrogen engine exhaust gas measurement devices and calibration methods play a crucial role in hydrogen engine R&D, optimization, and quality control. Due to the risk of misfire during hydrogen engine development, using closed-loop air-fuel ratio control with conventional natural gas engine oxygen sensors is extremely dangerous. High-temperature oxygen sensor probes can easily ignite unburned hydrogen, causing explosions. Therefore, open-loop air-fuel ratio control is currently used for hydrogen engines. This can lead to air-fuel ratio deviations, resulting in a series of problems such as engine misfire, detonation, and excessive exhaust temperatures. The only way to achieve the desired air-fuel ratio is to manually adjust the gas injection rate in each cylinder using the cylinder pressure curve. This adjustment process is cumbersome, often requiring more than ten adjustments. This makes it difficult to quickly adjust the air-fuel ratio, which is time-consuming and labor-intensive, and significantly slows testing progress. In addition, during the test, the exhaust gas is directly released. Without the exhaust gas to drive the supercharger turbine to work, the boost pressure will be lost, resulting in a loss of engine power. Summary of the Invention

[0003] The present invention provides a hydrogen engine exhaust measurement device, system, and calibration method. The present invention utilizes a hydrogen engine exhaust calibration system. The system transmits the solenoid valve opening time and duration to a control unit via an in-cylinder pressure acquisition system and an ECU, respectively, to control the opening and closing of the solenoid valve of the hydrogen engine exhaust measurement device. The system accurately measures the concentration of exhaust gas components. The ECU adjusts the engine air-fuel ratio to a predetermined value in real time. The measurement is repeated multiple times until the engine air-fuel ratio consistently reaches the predetermined value, and the calibration is completed. The calibration principle is simple, the results are accurate, and the operation is convenient. The air-fuel ratio can be quickly adjusted, typically requiring only 2-3 adjustments to achieve the desired air-fuel ratio, saving time and effort and accelerating the test process. The measurement device used is simple in structure, occupies little space, and is low in cost. After measurement and analysis, the exhaust gas re-enters the supercharger through an outlet pipe connected between the engine exhaust manifold and the supercharger, ensuring engine power. Multiple measurement device interfaces are provided on the measurement chamber to connect different measurement devices, enabling simultaneous calibration of gas component concentrations and other exhaust gas measurements, saving measurement costs.

[0004] The specific plan is as follows:

[0005] A hydrogen engine exhaust gas measurement device includes an exhaust gas measurement channel, a solenoid valve assembly and a measuring device. The exhaust gas measurement channel is a tubular structure that is approximately U-shaped. The solenoid valve assembly can be opened and closed and fixedly connected to the pipe openings at both ends of the exhaust gas measurement channel. The measuring device is fixedly connected to the middle of the exhaust gas measurement channel.

[0006] During hydrogen engine development, cylinder knock or misfire can occur. This requires testing the exhaust gas composition of individual cylinders to precisely control the air-fuel ratio in each cylinder and achieve efficient engine operation. The present invention employs a calibration method for a hydrogen engine exhaust calibration system. This method precisely measures the concentration of the measured component in the exhaust gas at any given moment. Based on the test results, the engine ECU (Electronic Control Unit) adjusts the air-fuel ratio to maintain a predetermined value. This calibration method determines the combustion quality within the engine cylinder by measuring exhaust gas components, such as the concentration of oxygen or hydrogen. A high oxygen content in the exhaust gas indicates lean combustion within the cylinder and a low hydrogen injection rate, resulting in high pollutant emissions and requiring higher post-processing capabilities. Conversely, a high hydrogen content indicates rich combustion within the cylinder and an excessive hydrogen injection rate, which can lead to elevated exhaust temperatures and challenge the reliability of the engine's exhaust manifold and cylinder head. Measuring the exhaust gas component concentrations allows the ECU to adjust the engine's air-fuel ratio in real time. If the exhaust gas contains a high level of oxygen, the hydrogen injection rate is increased to bring the air-fuel ratio to a predetermined value. If the exhaust gas contains a high level of hydrogen, the hydrogen injection rate is reduced to bring the air-fuel ratio to a predetermined value. Operating the engine within a reasonable air-fuel ratio range ensures both emissions and durability. After multiple measurements and calibrations, the calibration is complete when the air-fuel ratio stabilizes.

[0007] The calibration method of the present invention is applied to the hydrogen engine exhaust calibration system of the present invention, which includes the hydrogen engine exhaust measurement device of the present invention. The engine ECU of the present invention obtains the crankshaft angle value R of the engine to be tested, calculates the duration T for controlling exhaust gas entry, i.e., the duration of solenoid valve opening, using the formula T = R / engine speed ÷ 60 × 360, and sends it to the control unit. The in-cylinder pressure acquisition system observes the cylinder pressure establishment process of the engine in real time based on the in-cylinder pressure. The initial rise in cylinder pressure is the compression stroke, and the rapid rise after a gentle rise represents ignition and the engine working stroke. The subsequent cylinder pressure begins to decrease, indicating the end of working and the beginning of the exhaust stroke. The inlet solenoid valve can be opened when the cylinder pressure begins to decrease. The in-cylinder acquisition system confirms the solenoid valve opening time based on the cylinder pressure establishment process and sends a signal to the control unit. The control unit sends a control signal to the inlet solenoid valve and the outlet solenoid valve. The air inlet solenoid valve opens after receiving the signal of the solenoid valve opening time, and the air outlet solenoid valve is closed at the same time, and the exhaust gas enters the hydrogen engine exhaust gas measuring device. When the solenoid valve opening duration expires, the air inlet solenoid valve closes, and the air outlet solenoid valve opens at the same time. The measured exhaust gas enters the supercharger through the air outlet solenoid valve, pushing the supercharger worm gear to rotate and ensure the engine power. The engine ECU corrects the air-fuel ratio according to the measurement results of the gas concentration measuring device so that the air-fuel ratio reaches a predetermined value. Repeat the above steps many times until the air-fuel ratio continuously reaches the predetermined value, and the calibration is completed. The use of the hydrogen engine exhaust gas measuring device of the present invention to accurately measure the concentration of the gas components of a single cylinder exhaust can avoid measurement errors caused by mixing the exhaust gas of other cylinders in the exhaust manifold.

[0008] The exhaust gas measurement channel of the hydrogen engine exhaust gas measurement device is designed to be an approximately U-shaped tubular structure with a simple and compact structure and small space occupation. The exhaust gas measurement channel includes a measurement cavity, a measurement device interface, an air inlet pipe and an air outlet pipe; the air inlet pipe and the air outlet pipe are symmetrically fixedly installed on the left and right side walls of the measurement cavity respectively to form an approximately U-shaped tubular structure, and the solenoid valve assembly includes an air inlet solenoid valve and an air outlet solenoid valve, which can be opened and closed and fixedly installed on the end pipe openings of the air inlet pipe and the air outlet pipe respectively. The measurement device interface is fixedly connected to the measurement cavity, and an axial through hole is provided at the center of the measurement device interface for the measurement device to take air. The number of measurement device interfaces can be one or more. The present invention prefers multiple, so that multiple types of exhaust gas measurements can be performed simultaneously without affecting the calibration results. Although the technical solution of selecting one measurement device interface and two measurement device interfaces is used as an example in the present invention, it does not mean that the technical solution of protecting the provision of more measurement device interfaces is abandoned. The measurement device is fixedly connected to the measurement cavity through the corresponding measurement device interface. This measurement device, equipped with multiple measurement device interfaces, not only calibrates the concentration of single-cylinder exhaust gas components by measuring them, but can also connect to various other measurement devices to perform other types of gas measurements simultaneously with calibration. For example, connecting a particle measurement device can indirectly analyze the sealing condition of piston rings and valve oil seals in the cylinder. Since hydrogen engines burn hydrogen, which lacks carbon, particulate matter can only be caused by oil entering the cylinder and burning, thus enabling the determination of cylinder sealing conditions. This hydrogen engine exhaust measurement device can save measurement and labor costs.

[0009] Due to the limited space in the engine compartment, hydrogen engine exhaust gas calibration is not performed directly on the vehicle, but rather on an engine performance test bench. The hydrogen engine exhaust gas calibration system of the present invention includes the hydrogen engine exhaust gas measurement device and the engine performance test bench. The engine to be tested is mounted on the engine performance test bench. One end of the exhaust manifold of the cylinder to be tested is fixedly connected to the engine to be tested. The other end of the exhaust manifold of the cylinder to be tested is fixedly connected to the engine exhaust manifold, which is fixedly connected to the supercharger. The other end of the inlet solenoid valve is fixedly connected to the exhaust manifold of the cylinder to be tested via a flange, and the other end of the outlet solenoid valve is fixedly connected between the engine exhaust manifold and the supercharger via a flange. The control unit of the engine electronic control system component is electrically connected to the engine ECU, the in-cylinder pressure acquisition system, the inlet solenoid valve, and the outlet solenoid valve.

[0010] Furthermore, the exhaust gas measurement channel includes a measuring cavity, a measuring equipment interface, an air inlet pipe and an air outlet pipe. The upper portion of the measuring cavity is fixedly connected to a measuring equipment interface, and the measuring equipment interface and the measuring equipment are fixedly connected. The air inlet pipe and the air outlet pipe are both approximately L-shaped pipes, and the pipe openings at the ends of the short pipes of the air inlet pipe and the air outlet pipe are symmetrically fixedly connected to the left and right side walls of the measuring cavity to form an approximately U-shaped tubular structure. The solenoid valve assembly includes an air inlet solenoid valve and an air outlet solenoid valve. One end of the air inlet solenoid valve can be opened and closed and fixedly connected to the pipe opening at the end of the long pipe of the air inlet pipe, and one end of the air outlet solenoid valve can be opened and closed and fixedly connected to the pipe opening at the end of the long pipe of the air outlet pipe.

[0011] The shapes of the air inlet pipe and the air outlet pipe of the present invention match the shapes of other components in the engine, ensuring that they do not interfere with each other.

[0012] Furthermore, the measuring device includes a gas concentration measuring device, and the gas concentration measuring device is fixedly connected to the measuring device interface.

[0013] The present invention performs calibration by measuring the gas component concentration of the single-cylinder exhaust. The used measuring device is a gas concentration measuring device, which is fixedly connected to the measuring device interface.

[0014] Furthermore, the exhaust gas measurement channel also includes another measurement device interface, which is fixedly connected to the measurement cavity. The measurement device also includes a particulate matter measurement device, which is fixedly connected to the other measurement device interface. During actual measurement, other measurement devices can also be replaced as needed.

[0015] The exhaust gas measurement channel of the present invention can be equipped with multiple measurement device interfaces. The present invention uses two measurement device interfaces as an example. The measurement device also includes a particulate matter measurement device, and the gas concentration measurement device and the particulate matter measurement device are fixedly connected to the two measurement device interfaces. The particulate matter measurement device measures the value of particulate matter in the exhaust gas. The simultaneous measurement of particulate matter values does not affect the calibration of the air-fuel ratio after measuring the exhaust gas concentration using the gas concentration device, saving measurement and labor costs.

[0016] A hydrogen engine exhaust gas calibration system comprises the hydrogen engine exhaust gas measuring device and an engine performance test bench, wherein the engine performance test bench comprises an exhaust manifold of a cylinder to be tested, an engine exhaust manifold, a supercharger, and an engine electronic control system component. The exhaust manifold of the cylinder to be tested is fixedly connected to the engine exhaust manifold, which is in turn fixedly connected to the supercharger. The other end of an air inlet solenoid valve is openably and closably fixedly connected to the exhaust manifold of the cylinder to be tested via a flange. The other end of an air outlet solenoid valve is openably and closably fixedly connected between the engine exhaust manifold and the supercharger via a flange. Partial components of the engine electronic control system component are electrically connected to the air inlet solenoid valve and the air outlet solenoid valve.

[0017] The other end of the inlet solenoid valve is fixedly connected to the exhaust manifold of the cylinder to be tested via a flange, and the other end of the outlet solenoid valve is fixedly connected between the engine exhaust manifold and the supercharger via a flange. After the gas concentration measurement equipment completes measurement and analysis, the exhaust gas enters the supercharger through the outlet solenoid valve, driving the supercharger turbine to operate, ensuring that the engine power is not lost. Because the calibration process is repeated multiple times and only ends when the air-fuel ratio reaches a predetermined value and stabilizes, if the exhaust gas is released, there will be no exhaust gas to drive the supercharger worm gear, which will cause engine power loss. This is because the engine requires high intake pressure to ensure power output. The supercharger is the means to provide high intake pressure. The supercharger needs engine exhaust gas to drive the turbine, which drives the supercharger's compression end to compress fresh air and increase intake pressure. If the exhaust gas is released and does not drive the turbine, the boost pressure will be partially lost, resulting in engine power loss. The design of the present invention avoids this problem.

[0018] Furthermore, the engine electronic control system components include a control unit, an engine ECU and an in-cylinder pressure acquisition system. The control unit is electrically connected to the engine ECU, the in-cylinder pressure acquisition system, the intake solenoid valve and the outlet solenoid valve respectively. The engine ECU includes a crankshaft position sensor.

[0019] The control unit is electrically connected to the engine ECU, the in-cylinder pressure acquisition system, the intake solenoid valve, and the exhaust solenoid valve. The engine ECU includes a built-in crankshaft position sensor. When calibration begins, the engine ECU uses the crankshaft angle information collected from the crankshaft position sensor to calculate the solenoid valve opening duration based on the formula T = R / engine speed ÷ 60 × 360, and sends this information to the control unit. The in-cylinder pressure acquisition system determines the solenoid valve opening time based on the cylinder pressure buildup under real-time operating conditions. Specifically, the intake solenoid valve opens when the cylinder pressure begins to drop and the engine completes its exhaust stroke. This information is then sent to the control unit, which in turn transmits the solenoid valve opening time and duration to the solenoid valve assembly. This allows for precise measurement of the concentration of the component to be measured in the exhaust gas at any given moment. Based on the test results, the engine ECU adjusts the air-fuel ratio to maintain the desired value.

[0020] A calibration method for a hydrogen engine exhaust calibration system is applied to the aforementioned hydrogen engine exhaust calibration system, and the steps are as follows:

[0021] S1. Connect the engine to be tested to the engine performance test bench;

[0022] S2. Obtain the crankshaft angle value R of the engine to be tested and calculate the duration T of controlling the entry of exhaust gas.

[0023] T = R / engine speed ÷ 60 × 360;

[0024] Obtaining a real-time pressure value p in the cylinder of the engine to be tested, and determining the exhaust gas entry start time t based on a preset correspondence between the engine cylinder pressure value and the exhaust gas entry start time;

[0025] S3. Control the amount of exhaust gas entering based on t and T, measure the concentration of the component to be measured in the entering exhaust gas, discharge the exhaust gas into the supercharger after the measurement, and correct the air-fuel ratio based on the measurement result to control the air-fuel ratio to reach a predetermined value;

[0026] S4. Repeat the above steps multiple times to correct the air-fuel ratio multiple times. When the air-fuel ratio continuously reaches the predetermined value within the set time, the calibration is completed.

[0027] Furthermore, steps S2 and S3 specifically include:

[0028] The engine ECU obtains crankshaft angle information from the crankshaft position sensor and calculates the solenoid valve opening duration based on the formula T = R / engine speed ÷ 60 × 360. The in-cylinder pressure acquisition system determines the solenoid valve opening time based on the corresponding relationship between the in-cylinder pressure value and the start time of exhaust gas inlet.

[0029] The control unit obtains the solenoid opening duration and the solenoid valve opening time, and controls the air inlet solenoid valve to open and the air outlet solenoid valve to close to control the amount of exhaust gas entering. The gas concentration measuring device measures the exhaust gas. Based on the measurement results, the engine ECU corrects the air-fuel ratio to control the air-fuel ratio to reach a predetermined value.

[0030] Furthermore, the engine ECU corrects the air-fuel ratio. The specific steps are as follows: if the exhaust gas contains more oxygen, the hydrogen injection amount is increased to control the air-fuel ratio to a predetermined value; if the exhaust gas contains more hydrogen, the hydrogen injection amount is reduced to control the air-fuel ratio to a predetermined value.

[0031] Furthermore, a particle matter measuring device is fixedly connected to the test chamber. During the calibration process, the particle matter measuring device measures the amount of particulate matter in the exhaust gas to determine the sealing condition of the piston ring and valve oil seal in the cylinder: if particulate matter is detected, the sealing of the cylinder is poor; if no particulate matter is detected, the sealing of the cylinder is good.

[0032] Compared with the prior art, the present invention has the following beneficial effects:

[0033] 1. The present invention provides a hydrogen engine exhaust calibration method, which is applied to a hydrogen engine exhaust calibration system. The solenoid valve opening time is determined by an in-cylinder pressure acquisition system, and the engine ECU calculates the solenoid valve opening duration based on the crankshaft angle. The solenoid valve opening time and duration are sent to a control unit to control the opening and closing of the solenoid valve of the hydrogen engine exhaust device, accurately measuring the concentration of gas components in the exhaust gas. The engine air-fuel ratio is adjusted to a predetermined value by the ECU. The calibration principle is simple, the operation is convenient, the operation is labor-saving, and the test progress is fast.

[0034] 2. The hydrogen engine exhaust gas measurement device of the present invention has a simple structure, occupies little space and is low in cost;

[0035] 3. After the measurement of the present invention is completed, the exhaust gas is discharged into the supercharger by opening the outlet solenoid valve connected to the outlet pipe between the engine exhaust manifold and the supercharger to ensure the engine power;

[0036] 4. The measurement chamber is equipped with multiple measurement equipment interfaces that can be connected to different measurement equipment. It can perform other exhaust gas measurements while calibrating the gas component concentration, saving measurement costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Figure 1 Schematic diagram of the structure of the hydrogen engine exhaust gas measuring device of the present invention;

[0038] Figure 2 Schematic diagram of the structure of the exhaust gas measurement channel of the present invention;

[0039] Figure 3 Schematic diagram of the working principle of the calibration method of the hydrogen engine exhaust calibration system of the present invention;

[0040] Figure 4 This is an analysis diagram of the in-cylinder pressure acquisition system of the present invention;

[0041] Figure 5 This is a comparison chart of the adjustment speeds of the calibration method of the present invention and the method of manually adjusting the air-fuel ratio using the cylinder pressure curve.

[0042] In the picture:

[0043] 1. Exhaust gas measurement channel; 1.1. Measurement chamber; 1.2. Measurement equipment interface; 1.3. Inlet pipe; 1.4. Outlet pipe; 2. Solenoid valve assembly; 2.1. Inlet solenoid valve; 2.2. Outlet solenoid valve; 3. Measuring equipment. DETAILED DESCRIPTION

[0044] To make the objectives, technical solutions, and advantages of the present invention more apparent, the present invention will be further described in detail below with reference to the accompanying drawings. It is apparent that the embodiments described are only some embodiments of the present invention, rather than all embodiments. All other embodiments obtained by persons of ordinary skill in the art based on the embodiments of the present invention without creative effort are intended to fall within the scope of protection of the present invention.

[0045] The terms used in the present invention are for the purpose of describing specific embodiments only and are not intended to limit the present invention. The singular forms "a", "an", "the" and "the" used in the present invention and the appended claims are also intended to include plural forms, unless the context clearly indicates otherwise, and "a plurality" generally includes at least two.

[0046] It should be noted that the directions or positional relationships indicated by the terms "front", "rear", "inside", "outside", "left", "right", etc. in the present invention are based on the directions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific direction, be constructed and operated in a specific direction. Therefore, it should not be understood as a limitation on the present invention.

[0047] It should be noted in particular that any symbols and / or numbers in the specification that are not marked in the accompanying drawings are not drawing marks.

[0048] The embodiment of the present invention, namely a hydrogen engine exhaust gas measurement device, system and calibration method, is described below in conjunction with Figure 1 、 Figure 2 、 Figure 3 、 Figure 4 and Figure 5 Provide detailed explanation.

[0049] Example 1:

[0050] See Figure 1 As shown, a hydrogen engine exhaust gas measuring device includes an exhaust gas measuring channel 1, a solenoid valve assembly 2 and a measuring device 3. The exhaust gas measuring channel 1 is an approximately U-shaped tubular structure. The solenoid valve assembly 2 can be opened and closed and fixedly connected to the pipe openings at both ends of the exhaust gas measuring channel 1. The measuring device 3 is fixedly connected to the middle of the exhaust gas measuring channel 1.

[0051] See Figure 2 As shown, the exhaust gas measurement channel 1 includes a measuring cavity 1.1, a measuring device interface 1.2, an air inlet pipe 1.3 and an air outlet pipe 1.4. The upper portion of the measuring cavity 1.1 is fixedly connected to the measuring device interface 1.2, and the measuring device interface 1.2 is fixedly connected to the measuring device 3. The air inlet pipe 1.3 and the air outlet pipe 1.4 are both approximately L-shaped pipes. One end of the short pipes of the air inlet pipe 1.3 and the air outlet pipe 1.4 are symmetrically fixedly connected to the left and right side walls of the measuring cavity 1.1 to form an approximately U-shaped tubular structure. The solenoid valve assembly 2 includes an air inlet solenoid valve 2.1 and an air outlet solenoid valve 2.2. One end of the air inlet solenoid valve 2.1 can be opened and closed and fixedly connected to the pipe mouth at the other end of the air inlet pipe 1.3. One end of the air outlet solenoid valve 2.2 can be opened and closed and fixedly connected to the pipe mouth at the other end of the air outlet pipe 1.4.

[0052] The measuring device 3 comprises a gas concentration measuring device, which is fixedly connected to the measuring device interface 1 . 2 .

[0053] Example 2:

[0054] A hydrogen engine exhaust gas measurement device includes an exhaust gas measurement channel 1, a solenoid valve assembly 2 and a measuring device 3. The exhaust gas measurement channel 1 is a tubular structure that is approximately U-shaped. The solenoid valve assembly 2 can be opened and closed and fixedly connected to the pipe openings at both ends of the exhaust gas measurement channel 1. The measuring device 3 is fixedly connected to the middle of the exhaust gas measurement channel 1.

[0055] The exhaust gas measurement channel 1 includes a measuring cavity 1.1, a measuring device interface 1.2, an intake pipe 1.3 and an outlet pipe 1.4. The upper portion of the measuring cavity 1.1 is fixedly connected to the measuring device interface 1.2, and the measuring device interface 1.2 is fixedly connected to the measuring device 3. The intake pipe 1.3 and the outlet pipe 1.4 are both approximately L-shaped pipes. One end of the short pipes of the intake pipe 1.3 and the outlet pipe 1.4 are symmetrically fixedly connected to the left and right side walls of the measuring cavity 1.1 to form an approximately U-shaped tubular structure. The solenoid valve assembly 2 includes an intake solenoid valve 2.1 and an outlet solenoid valve 2.2. One end of the intake solenoid valve 2.1 can be opened and closed and fixedly connected to the pipe mouth at the other end of the intake pipe 1.3. One end of the outlet solenoid valve 2.2 can be opened and closed and fixedly connected to the pipe mouth at the other end of the outlet pipe 1.4.

[0056] The measuring device 3 comprises a gas concentration measuring device, which is fixedly connected to the measuring device interface 1 . 2 .

[0057] The exhaust gas measurement channel 1 further includes another measurement device interface 1.2, which is fixedly connected to the measurement cavity 1.1. The measurement device 3 further includes a particle measurement device, which is fixedly connected to the other measurement device interface 1.2.

[0058] Example 3:

[0059] The present invention also provides a hydrogen engine exhaust calibration system, including the hydrogen engine exhaust measurement device described above, wherein the hydrogen engine exhaust measurement device is only provided with a measurement device interface 1.2, and the gas concentration measurement device is fixedly connected to the measurement device interface 1.2; the hydrogen engine exhaust calibration system also includes the exhaust manifold of the cylinder to be measured, the engine exhaust manifold, the supercharger and the engine electronic control system component, the exhaust manifold of the cylinder to be measured, the engine exhaust manifold and the supercharger are all fixedly connected in the automobile, the exhaust manifold of the cylinder to be measured is fixedly connected to the engine exhaust manifold, and the engine exhaust manifold is fixedly connected to the supercharger via a flange, the other end of the air inlet solenoid valve 2.1 can be opened and closed and fixedly connected to the exhaust manifold of the cylinder to be measured, the other end of the air outlet solenoid valve 2.2 can be opened and closed and fixedly connected to the flange connecting the engine exhaust manifold and the supercharger, and some components of the engine electronic control system component are electrically connected to the air inlet solenoid valve 2.1 and the air outlet solenoid valve 2.2.

[0060] The engine electronic control system components include a control unit, an engine ECU, and an in-cylinder pressure acquisition system. The control unit is electrically connected to the engine ECU, the in-cylinder pressure acquisition system, the intake solenoid valve 2.1, and the outlet solenoid valve 2.2 respectively. The engine ECU includes a crankshaft position sensor.

[0061] Example 4:

[0062] The present invention also provides a hydrogen engine exhaust calibration system, comprising the hydrogen engine exhaust measurement device described above, wherein the hydrogen engine exhaust measurement device is provided with two measurement device interfaces 1.2, and a gas concentration measurement device and a particulate matter measurement device are respectively fixedly connected to the two measurement device interfaces 1.2; the hydrogen engine exhaust calibration system also comprises an exhaust manifold of a cylinder to be measured, an engine exhaust manifold, a supercharger and an engine electronic control system component, wherein the exhaust manifold of the cylinder to be measured, the engine exhaust manifold and the supercharger are all fixedly connected in a vehicle, the exhaust manifold of the cylinder to be measured is fixedly connected to the engine exhaust manifold, and the engine exhaust manifold is fixedly connected to the supercharger via a flange, the other end of an air inlet solenoid valve 2.1 is openably and closably fixedly connected to the exhaust manifold of the cylinder to be measured, the other end of an air outlet solenoid valve 2.2 is openably and closably fixedly connected to a flange connecting the engine exhaust manifold and the supercharger, and some components of the engine electronic control system component are electrically connected to the air inlet solenoid valve 2.1 and the air outlet solenoid valve 2.2.

[0063] The engine electronic control system components include a control unit, an engine ECU, and an in-cylinder pressure acquisition system. The control unit is electrically connected to the engine ECU, the in-cylinder pressure acquisition system, the intake solenoid valve 2.1, and the outlet solenoid valve 2.2 respectively. The engine ECU includes a crankshaft position sensor.

[0064] Example 5:

[0065] The present invention also provides a calibration method for a hydrogen engine exhaust gas calibration system, which is applied to the hydrogen engine exhaust gas calibration system, and the steps are as follows:

[0066] S1. Connect the engine to be tested to the engine performance test bench;

[0067] S2. Obtain the crankshaft angle value R of the engine to be tested and calculate the duration T of controlling the entry of exhaust gas.

[0068] T = R / engine speed ÷ 60 × 360;

[0069] See Figure 4 As shown, the real-time pressure value p in the cylinder of the engine to be tested is obtained, and the exhaust gas entry start time t is determined based on the corresponding relationship between the preset engine cylinder pressure value and the exhaust gas entry start time;

[0070] S3. Control the amount of exhaust gas entering based on t and T, measure the concentration of the component to be measured in the entering exhaust gas, discharge the exhaust gas into the supercharger after the measurement, and correct the air-fuel ratio based on the measurement result to control the air-fuel ratio to reach a predetermined value;

[0071] S4. Repeat the above steps multiple times to correct the air-fuel ratio multiple times. When the air-fuel ratio continuously reaches the predetermined value within the set time, the calibration is completed.

[0072] Steps S2 and S3 specifically include:

[0073] The engine ECU obtains the crankshaft angle information from the crankshaft position sensor and obtains the solenoid valve opening duration based on the formula T = R / engine speed ÷ 60 × 360; see Figure 4 As shown, the cylinder pressure acquisition system determines the solenoid valve opening time based on the corresponding relationship between the cylinder pressure value and the exhaust gas inlet start time;

[0074] The control unit obtains the solenoid opening duration and the solenoid valve opening time, and controls the air inlet solenoid valve to open and the air outlet solenoid valve to close to control the amount of exhaust gas entering. The gas concentration measuring device measures the exhaust gas. Based on the measurement results, the engine ECU corrects the air-fuel ratio to control the air-fuel ratio to reach a predetermined value.

[0075] The engine ECU corrects the air-fuel ratio. The specific steps are as follows: if the exhaust gas contains more oxygen, the hydrogen injection amount is increased to control the air-fuel ratio to a predetermined value; if the exhaust gas contains more hydrogen, the hydrogen injection amount is reduced to control the air-fuel ratio to a predetermined value.

[0076] Figure 4 This is the analysis diagram of the cylinder pressure acquisition system. The vertical axis is the cylinder pressure and the horizontal axis is the crankshaft angle. Figure 4 The process of cylinder pressure buildup during engine operation can be observed. The rising portion of the curve in the figure represents the compression stroke, followed by a gradual, rapid rise representing ignition and the engine's power stroke. The subsequent drop in cylinder pressure marks the end of power and the beginning of the exhaust stroke. The inlet solenoid valve can be opened when the cylinder pressure begins to drop. The in-cylinder data acquisition system determines the solenoid valve opening timing based on the cylinder pressure buildup process and sends a signal to the control unit, which then sends a control signal to the solenoid valve assembly.

[0077] The calibration method used in this embodiment and the existing cylinder pressure curve artificial adjustment method of the air-fuel ratio both adjust the air-fuel ratio by adjusting the injection amount of hydrogen. The two are compared to obtain a graph

[0078] Before using this method After using this method Adjustment times 15 4 Time required (minutes) 30 8 Injector adjustment amount (base 1.0) 0.01 0.5 Final injection amount 1.12 1.12 and Figure 5 It can be determined that the calibration method of the present invention is far superior to the existing adjustment method, saving time and effort.

[0079] Example 6:

[0080] The present invention also provides a calibration method for a hydrogen engine exhaust gas calibration system, which is applied to the hydrogen engine exhaust gas calibration system, and the steps are as follows:

[0081] S1. Connect the engine to be tested to the engine performance test bench;

[0082] S2. Obtain the crankshaft angle value R of the engine to be tested and calculate the duration T of controlling the entry of exhaust gas.

[0083] T = R / engine speed ÷ 60 × 360;

[0084] Obtaining a real-time pressure value p in the cylinder of the engine to be tested, and determining the exhaust gas entry start time t based on a preset correspondence between the engine cylinder pressure value and the exhaust gas entry start time;

[0085] S3. Control the amount of exhaust gas entering based on t and T, measure the concentration of the component to be measured in the entering exhaust gas, discharge the exhaust gas into the supercharger after the measurement, and correct the air-fuel ratio based on the measurement result to control the air-fuel ratio to reach a predetermined value;

[0086] S4. Repeat the above steps several times to correct the air-fuel ratio several times. Figure 4 As shown, when the air-fuel ratio continues to reach the predetermined value within the set time, the calibration is completed.

[0087] Steps S2 and S3 specifically include:

[0088] The engine ECU obtains the crankshaft angle information from the crankshaft position sensor and obtains the solenoid valve opening duration based on the formula T = R / engine speed ÷ 60 × 360; see Figure 4 As shown, the cylinder pressure acquisition system determines the solenoid valve opening time based on the corresponding relationship between the cylinder pressure value and the exhaust gas inlet start time;

[0089] The control unit obtains the solenoid opening duration and the solenoid valve opening time, and controls the air inlet solenoid valve to open and the air outlet solenoid valve to close to control the amount of exhaust gas entering. The gas concentration measuring device measures the exhaust gas. Based on the measurement results, the engine ECU corrects the air-fuel ratio to control the air-fuel ratio to reach a predetermined value.

[0090] The engine ECU corrects the air-fuel ratio. The specific steps are as follows: if the exhaust gas contains more oxygen, the hydrogen injection amount is increased to control the air-fuel ratio to a predetermined value; if the exhaust gas contains more hydrogen, the hydrogen injection amount is reduced to control the air-fuel ratio to a predetermined value.

[0091] A particle measurement device is also fixedly connected to the test chamber. During the calibration process, the particle measurement device measures the amount of particulate matter in the exhaust gas to determine the sealing condition of the piston ring and valve oil seal in the cylinder: if particulate matter is detected, the sealing of the cylinder is poor; if no particulate matter is detected, the sealing of the cylinder is good.

[0092] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the various embodiments of the present invention.

Claims

1. A hydrogen engine exhaust gas measuring device, characterized in that: The invention comprises an exhaust gas measurement channel (1), an electromagnetic valve assembly (2) and a measuring device (3); the exhaust gas measurement channel (1) is a tubular structure approximately in a U shape; the electromagnetic valve assembly (2) is respectively openably and closably fixedly connected to the pipe openings at both ends of the exhaust gas measurement channel (1); and the measuring device (3) is fixedly connected to the middle of the exhaust gas measurement channel (1).

2. The hydrogen engine exhaust gas measuring device according to claim 1, characterized in that: The exhaust gas measurement channel (1) comprises a measurement cavity (1.1), a measurement device interface (1.2), an air inlet pipe (1.3) and an air outlet pipe (1.4); the upper portion of the measurement cavity (1.1) is fixedly connected to the measurement device interface (1.2); the measurement device interface (1.2) and the measurement device (3) are fixedly connected; the air inlet pipe (1.3) and the air outlet pipe (1.4) are both approximately L-shaped pipes; the pipe opening at the end of the short pipe of the air inlet pipe (1.3) and the air outlet pipe (1.4) are connected to each other. The ends of the short tube of the measuring chamber (1.4) are fixedly connected to the left and right side walls of the measuring chamber (1.1) to form an approximately U-shaped tubular structure. The solenoid valve assembly (2) includes an air inlet solenoid valve (2.1) and an air outlet solenoid valve (2.2). One end of the air inlet solenoid valve (2.1) can be opened and closed and fixedly connected to the end of the long tube of the air inlet pipe (1.3). One end of the air outlet solenoid valve (2.2) can be opened and closed and fixedly connected to the end of the long tube of the air outlet pipe (1.4).

3. The hydrogen engine exhaust gas measuring device according to claim 2, characterized in that: The measuring device (3) comprises a gas concentration measuring device, which is fixedly connected to the measuring device interface (1.2).

4. The hydrogen engine exhaust gas measuring device according to claim 3, characterized in that: The exhaust gas measurement channel (1) further comprises another measurement device interface (1.2), the another measurement device interface (1.2) being fixedly connected to the measurement cavity (1.1), and the measurement device (3) further comprises a particulate matter measurement device, the particulate matter measurement device being fixedly connected to the another measurement device interface (1.2).

5. A hydrogen engine exhaust gas calibration system, characterized in that: The invention comprises a hydrogen engine exhaust gas measuring device according to any one of claims 1 to 4, and also comprises an engine performance test bench, wherein the engine performance test bench comprises an exhaust manifold of a cylinder to be tested, an engine exhaust manifold, a supercharger and an electronic control system component, wherein the exhaust manifold of the cylinder to be tested is fixedly connected to the engine exhaust manifold, the outlet pipe of the engine exhaust manifold is fixedly connected to the supercharger, the other end of the inlet solenoid valve (2.1) is fixedly connected to the exhaust manifold of the cylinder to be tested via a flange in an openable and closable manner, the other end of the outlet solenoid valve (2.2) is fixedly connected between the engine exhaust manifold and the supercharger via a flange in an openable and closable manner, and some components of the engine electronic control system component are electrically connected to the inlet solenoid valve (2.1) and the outlet solenoid valve (2.2).

6. The hydrogen engine exhaust gas calibration system according to claim 5, characterized in that: The engine electronic control system component comprises a control unit, an engine ECU and an in-cylinder pressure acquisition system, wherein the control unit is electrically connected to the engine ECU, the in-cylinder pressure acquisition system, an air inlet solenoid valve (2.1) and an air outlet solenoid valve (2.2), respectively, and the engine ECU comprises a crankshaft position sensor.

7. A calibration method for a hydrogen engine exhaust calibration system, applied to the hydrogen engine exhaust calibration system according to claim 5 or 6, characterized in that: Here are the steps: S1. Connect the engine to be tested to the engine performance test bench; S2. Obtain the crankshaft angle value R of the engine to be tested and calculate the duration T of controlling the entry of exhaust gas. T = R / engine speed ÷ 60 × 360; Obtaining a real-time pressure value p in the cylinder of the engine to be tested, and determining the exhaust gas entry start time t based on a preset correspondence between the engine cylinder pressure value and the exhaust gas entry start time; S3. Control the amount of exhaust gas entering based on t and T, measure the concentration of the component to be measured in the entering exhaust gas, discharge the exhaust gas into the supercharger after the measurement, and correct the air-fuel ratio based on the measurement result to control the air-fuel ratio to reach a predetermined value; S4. Repeat the above steps multiple times to correct the air-fuel ratio multiple times. When the air-fuel ratio continuously reaches the predetermined value within the set time, the calibration is completed.

8. The calibration method of the hydrogen engine exhaust calibration system according to claim 7, characterized in that: The steps S2 and S3 specifically include: The engine ECU obtains crankshaft angle information from the crankshaft position sensor and calculates the solenoid valve opening duration based on the formula T = R / engine speed ÷ 60 × 360. The in-cylinder pressure acquisition system determines the solenoid valve opening time based on the corresponding relationship between the in-cylinder pressure value and the start time of exhaust gas inlet. The control unit obtains the electromagnetic opening duration and the solenoid valve opening time. The control unit controls the air inlet solenoid valve to open and the air outlet solenoid valve to close at the same time to control the amount of exhaust gas entering. The gas concentration measuring equipment measures the exhaust gas. Based on the measurement results, the engine ECU corrects the air-fuel ratio and controls the air-fuel ratio to reach a predetermined value.

9. The calibration method of the hydrogen engine exhaust calibration system according to claim 8, characterized in that: The engine ECU corrects the air-fuel ratio. The specific steps are as follows: if the exhaust gas contains more oxygen, the hydrogen injection amount is increased to control the air-fuel ratio to a predetermined value; if the exhaust gas contains more hydrogen, the hydrogen injection amount is reduced to control the air-fuel ratio to a predetermined value.

10. The calibration method of the hydrogen engine exhaust calibration system according to claim 9, characterized in that: A particle measurement device is also fixedly connected to the test chamber. During the calibration process, the particle measurement device measures the amount of particulate matter in the exhaust gas to determine the sealing condition of the piston ring and valve oil seal in the cylinder: if particulate matter is detected, the sealing of the cylinder is poor; if no particulate matter is detected, the sealing of the cylinder is good.

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