A method, system and device for testing transient mass flow rate of high pressure direct injection gas

Abstract

The application discloses a high-pressure direct-injection gas transient mass flow rate testing method, system and device, relates to the field of transient mass flow rate testing, and comprises the following steps: acquiring fuel injection amount measured by a gas mass flowmeter; the gas mass flowmeter is arranged on the upstream of a fuel injector gas inlet; acquiring pressure data at the fuel injector nozzle outlet measured by a force sensor; the force sensor is arranged at the fuel injector nozzle outlet; and applying a momentum method based on the pressure data and combining the fuel injection amount to obtain a gas transient mass flow rate. The principle of the combined testing based on the gas mass flowmeter and the momentum method achieves the purpose of testing the high-pressure direct-injection gas transient mass flow rate under high back pressure.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of transient mass flow rate testing, in particular to a high-pressure direct injection gas transient mass flow rate testing method, system and device suitable for high back pressure. BACKGROUND

[0002] With the increasingly stringent emission regulations, various mainstream dual-fuel engine technologies cannot simultaneously meet the requirements of power and emission, and the rapid development of engine electronic control technology has become one of the leading technologies in the internal combustion engine industry, which provides an extremely superior policy basis, broad market demand and great development potential for high-pressure direct injection dual-fuel engines, leading natural gas in-cylinder high-pressure direct injection technology to become the only way for the development of natural gas engine industry technology.

[0003] At the same time, in recent years, with the gradual aggravation of energy depletion and environmental pollution, countries and organizations around the world have introduced more stringent emission regulations, bringing new challenges to traditional engines. At present, high-pressure direct injection natural gas engines are developing towards high thermal efficiency and high injection pressure. In high back environment, the research and control of the transient characteristics of the engine become a hot spot, and the realization of fuel injection consistency and cylinder consistency puts forward new challenges to fuel injection control technology.

[0004] The dual-fuel injector, as the final actuator of the fuel system of the high-pressure direct injection natural gas engine, its working characteristics directly determine the fuel supply in the engine cylinder and the subsequent combustion. However, due to the unique concentric double-shaft needle structure of the dual-fuel injector, the external gas needle valve is directly exposed to the high-pressure environment of the cylinder, which inevitably leads to the difference between the movement form of the external gas needle valve of the dual-fuel injector and that of the common rail fuel injector, resulting in the difference in fuel injection process, making it difficult to refer to the existing database.

[0005] Researchers have conducted related research, and there are a series of working principles that can be applied to the measurement of high-pressure direct injection gas transient mass flow rate, such as zeuch volume method, momentum method using force sensor to depict gas injection law, and laser Doppler anemometer for fuel injector fuel flow evaluation, etc. The above measurement methods require a large amount of experimental data, rely on basic fluid dynamics and related technology, which includes huge calculation and experimental equipment, consumes a lot of manpower and equipment, and destroys the original mechanical structure of the diesel engine, resulting in inconsistency with the actual running state of the diesel engine fuel injection amount, and cannot realize the rapid online measurement of high-pressure direct injection gas transient mass flow rate.

[0006] There are two difficulties in the test of high-pressure direct injection gas transient mass flow rate with high back pressure, one is real-time, the real-time of jet quantity identification is the premise of gas injection control strategy, and the gas control strategy further realizes the control of in-cylinder combustion, and only mass flow meter cannot realize the test and analysis of gas transient characteristics. The second is that based on the momentum method, only the shape of the gas mass flow rate can be obtained, but due to the gas expansion phenomenon, the quantitative analysis of the gas mass flow rate cannot be realized.

[0007] At present, the test methods for fuel injector transient mass flow are mostly concentrated on the measurement of liquid fuel, and only a few scholars study the test method of gas fuel transient mass flow. Faghani E. obtains the momentum flow of HPDI gas jet by testing the impact force of high-pressure gas pulse jet, and realizes the test of gas jet outlet momentum. Abmus K. found that the mass flow rate curve can be described by the momentum flow curve of gas, but the gas injection quantity of single injection cycle needs to be known. SUMMARY

[0008] The purpose of the present application is to provide a high-pressure direct injection gas transient mass flow rate test method, system and device, which realizes the purpose of testing high-pressure direct injection gas transient mass flow rate under high back pressure by the principle of combined test based on gas mass flow meter and momentum method, solves the problem of high-pressure direct injection gas transient mass flow rate test, and provides a technical means for studying gas injection characteristics in high back pressure environment.

[0009] To achieve the above purpose, the present application provides the following scheme:

[0010] A high-pressure direct injection gas transient mass flow rate test method, the method comprises:

[0011] obtaining the fuel injection quantity measured by a gas mass flow meter; the gas mass flow meter is arranged upstream of the gas inlet of the fuel injector;

[0012] obtaining the pressure data at the outlet of the fuel injector nozzle measured by a force sensor; the force sensor is arranged at the outlet of the fuel injector nozzle;

[0013] obtaining the fuel injection quantity measured by a gas mass flow meter; the gas mass flow meter is arranged upstream of the gas inlet of the fuel injector;

[0014] Optionally, the gas transient mass flow rate is obtained based on the pressure data by applying the momentum method and combining the fuel injection quantity, specifically comprising:

[0015] obtaining the shape of the jet rule curve according to the pressure data combined with the momentum theorem;

[0016] calibrating the fuel injection quantity and the shape of the jet rule curve to obtain the gas transient mass flow rate.

[0017] Optionally, the curve shape of the fuel mass flow rate corresponds to an expression of:

[0018]

[0019] Wherein, F(t) represents the pressure data; represents the fuel mass flow rate.

[0020] The present application provides a high-pressure direct injection gas transient mass flow rate test system, the system comprising:

[0021] A jet amount acquisition module for acquiring the fuel jet amount measured by a gas mass flow meter; the gas mass flow meter is arranged upstream of the fuel inlet of the fuel injector;

[0022] A jet pressure acquisition module for acquiring the pressure data measured by a force sensor at the outlet of the fuel injector nozzle; the force sensor is arranged at the outlet of the fuel injector nozzle;

[0023] A mass flow rate test module for deriving the transient mass flow rate of the fuel gas based on the pressure data by applying the momentum method combined with the fuel jet amount.

[0024] The present application provides a high-pressure direct injection gas transient mass flow rate test device, characterized in that the device comprises a gas mass flow meter, a gas force sensor, a fuel injector and a test module;

[0025] The gas mass flow meter is arranged at the upstream position of the fuel inlet of the fuel injector;

[0026] The gas force sensor is arranged at the nozzle outlet of the fuel injector;

[0027] The test module is respectively connected with the gas mass flow meter and the gas force sensor, and is used for executing the high-pressure direct injection gas transient mass flow rate test method.

[0028] Optionally, the device further comprises a fuel gas storage tank, an oil storage tank and a constant volume container;

[0029] The fuel gas sprayed from the nozzle of the fuel injector is injected into the constant volume container;

[0030] The fuel gas storage tank is connected with the fuel inlet of the fuel injector in sequence through a gas compressor, a gas pressure control device and a gas rail; the gas mass flow meter is arranged on the pipeline connecting the gas rail and the fuel inlet of the fuel injector;

[0031] The oil storage tank is connected with the fuel inlet of the fuel injector in sequence through an oil pump and an oil rail.

[0032] According to the specific embodiments provided by the application, the following technical effects are disclosed:

[0033] The application provides a high-pressure direct injection gas transient mass flow rate testing method, system and device. Based on the testing principle of the combination of the gas mass flow meter and the momentum method, the jet amount data measured by the gas mass flow meter is used to calibrate the shape of the gas mass flow rate based on the momentum method, so that the high-pressure direct injection gas transient mass flow rate is directly and effectively obtained, and a technical means is provided for studying the gas injection characteristics in the high back pressure environment. The jet amount is used as the measurement target, and the jet amount is obtained in a simple way. On the basis of the original equipment, only the gas flow meter needs to be installed upstream of the gas inlet of the dual fuel injector, without damaging the original structure arrangement. The application can be applied to the structure system of the actual diesel engine. BRIEF DESCRIPTION OF DRAWINGS

[0034] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the drawings needed in the embodiments will be briefly introduced as follows. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative labor.

[0035] Figure 1 A high-pressure direct injection gas transient mass flow rate testing method flow chart is provided for the embodiment 1 of the present application.

[0036] Figure 2 A high-pressure direct injection gas transient mass flow rate testing device hardware structure diagram is provided for the embodiment 3 of the present application. DETAILED DESCRIPTION

[0037] The technical solutions in the embodiments of the present application will be described clearly and completely in combination with the drawings in the embodiments of the present application. Obviously, the described embodiments are only some embodiments of the present application, not all embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor are within the scope of protection of the present application.

[0038] The purpose of the present application is to provide a high-pressure direct injection gas transient mass flow rate testing method, system and device, which achieves the purpose of testing the high-pressure direct injection gas transient mass flow rate under high back pressure by the testing principle of the combination of the gas mass flow meter and the momentum method, solves the problem of testing the high-pressure direct injection gas transient mass flow rate, and provides a technical means for studying the gas injection characteristics in the high back pressure environment.

[0039] In order to make the above-mentioned purposes, characteristics and advantages of the present application more obvious and easy to understand, the present application will be further described in detail in combination with the drawings and specific embodiments.

[0040] Embodiment 1

[0041] As Figure 1 shown, the embodiment provides a high-pressure direct-injection gas transient mass flow rate test method, which comprises:

[0042] (1) obtaining the fuel injection amount measured by a gas mass flow meter; the gas mass flow meter is arranged upstream of the gas inlet of the fuel injector.

[0043] Gas transient mass flow rate: the mass of the injected gas per unit time at a certain time.

[0044] Gas injection amount: the mass of the gas injected by the injector in one injection cycle.

[0045] Injection amount acquisition: install a gas flow meter upstream of the gas inlet of the dual-fuel injector. Since the gas inlet of the dual-fuel injector is stored in the gas storage chamber, the only path for the gas to pass through the mass flow meter is to be injected from the injector nozzle, and the mass flow meter can accurately measure the single injection amount.

[0046] (2) obtaining the pressure data at the outlet of the fuel injector nozzle measured by a force sensor; the force sensor is arranged at the outlet of the fuel injector nozzle.

[0047] Injection law shape acquisition: the force sensor is arranged at the outlet of the gas nozzle, and the shape of the gas mass flow rate can be obtained based on the momentum method.

[0048] From the momentum theorem:

[0049] F t ·t=mv t (1)

[0050] Since the high-pressure gas jet will obviously expand at the nozzle, and the inertia of the gas jet is small. Therefore, the gas jet will obviously lose momentum before impacting the sensor surface. Using the momentum method requires the following modification to equation (1):

[0051] F t ·t=kmvt (2)

[0052] Where k is an uncertain constant between 0 and 1, used to describe the momentum loss of the gas jet. Since k is greatly affected by the ambient temperature and pressure, it is extremely difficult to solve it through an empirical formula. Therefore, for a gas jet, only the following expression can be obtained:

[0053]

[0054] Where F(t) represents the pressure data, i.e. the force signal value obtained by the sensor test. represents the fuel mass flow rate, for example, the methane transient mass flow rate.

[0055] The force signal can depict the shape of the fuel injection law curve with high signal-to-noise ratio, but cannot quantitatively depict the fuel injection rate. If accurate fuel injection law data are to be obtained, the fuel injection amount of the cycle needs to be obtained to calibrate the fuel injection law curve.

[0056] (3) obtaining the fuel transient mass flow rate based on the pressure data by applying the momentum method in combination with the fuel injection amount. Specifically comprising:

[0057] obtaining the shape of the fuel injection law curve according to the pressure data in combination with the momentum theorem;

[0058] calibrating the fuel injection amount and the shape of the fuel injection law curve to obtain the fuel transient mass flow rate.

[0059] Finally, the mass flow meter and the momentum method principle are combined, the fuel injection amount data measured by the mass flow meter is used to calibrate the shape of the fuel mass flow rate based on the momentum method, and the high-pressure direct injection fuel transient mass flow rate test in a high back pressure environment is realized.

[0060] The embodiment has the following advantages:

[0061] (1) The present application proposes a high-pressure direct injection fuel transient mass flow rate test method suitable for high back pressure. Based on the test principle of the combination of the mass flow meter and the momentum method, the fuel injection amount data measured by the mass flow meter is used to calibrate the shape of the fuel mass flow rate based on the momentum method, and the high-pressure direct injection fuel transient mass flow rate is directly and effectively obtained, which provides a technical means for studying the fuel injection characteristics in a high back pressure environment.

[0062] (2) The present application uses the fuel injection amount as the measurement target, and the fuel injection amount is obtained in a relatively simple manner. On the basis of the original equipment, only the gas flow meter needs to be installed upstream of the fuel injector gas inlet, without damaging the original structure arrangement, and the application can be applied to the structure system of the actual diesel engine.

[0063] (3) The present application directly and effectively tests the high-pressure direct injection fuel transient mass flow rate in a high back pressure environment, and proves that the present application can obtain a relatively ideal fuel injection law curve.

[0064] (4) The present application only needs to add a mass flow meter and a force sensor on the basis of the original injector, obtains the shape of the fuel mass flow rate based on the momentum method, and only needs to consider the service life of the mass flow meter and the sensor in the identification process, which is economical and easy to realize.

[0065] (5) The high-pressure direct-injection gas transient mass flow rate test method suitable for high back pressure is provided, high-pressure direct-injection gas transient mass flow rate test under high back pressure environment is realized, and the method can be used for online injection monitoring of an actual diesel engine, and the method has real-time performance.

[0066] Therefore, the scheme of the embodiment solves the test of high-pressure direct-injection gas transient mass flow rate which cannot be realized in the prior art, realizes the test of gas transient mass flow rate under high back pressure in actual operation of a high-pressure direct-injection natural gas engine, realizes real-time observation of high-pressure direct-injection gas transient mass flow rate, and directly and effectively realizes acquisition of high-pressure direct-injection gas transient mass flow rate based on the test principle of combination of a mass flow meter and a momentum method, the injection amount data measured by the mass flow meter calibrates the shape of gas mass flow rate based on the momentum method, the high-pressure environment in a cylinder can be simulated to the maximum extent, and the scheme serves high-pressure gas injection characteristic research and injection amount MAP calibration of an engine control system.

[0067] Embodiment 2

[0068] The embodiment provides a high-pressure direct-injection gas transient mass flow rate test system, and the system comprises:

[0069] An injection amount acquisition module is configured to acquire fuel injection amount measured by a gas mass flow meter, and the gas mass flow meter is arranged upstream of a fuel inlet of a fuel injector.

[0070] An injection pressure acquisition module is configured to acquire pressure data at an outlet of a nozzle of the fuel injector measured by a force sensor, and the force sensor is arranged at the outlet of the nozzle of the fuel injector.

[0071] A mass flow rate test module is configured to derive gas transient mass flow rate based on the pressure data by applying a momentum method and combining the fuel injection amount.

[0072] Embodiment 3

[0073] As shown in Figure 2 The embodiment provides a high-pressure direct-injection gas transient mass flow rate test device, and the device comprises a gas mass flow meter, a gas force sensor, a fuel injector, and a test module (for example, an upper computer).

[0074] The gas mass flow meter is arranged at a position upstream of a fuel inlet of the fuel injector.

[0075] The gas force sensor is arranged at an outlet of a nozzle of the fuel injector.

[0076] The test module is respectively connected with the gas mass flow meter and the gas force sensor, and is configured to execute the high-pressure direct-injection gas transient mass flow rate test method provided in the embodiment 1.

[0077] The device further comprises a gas storage tank, an oil storage tank and a constant volume container.

[0078] The gas sprayed from the nozzle of the fuel injector is injected into the constant volume container.

[0079] The gas storage tank is connected to the fuel inlet of the fuel injector in sequence through a gas compressor, a gas pressure control device and a gas rail.

[0080] The oil storage tank is connected to the fuel inlet of the fuel injector in sequence through an oil pump and an oil rail.

[0081] Embodiment 4

[0082] The embodiment also provides an electronic device comprising a memory and a processor, the memory being configured to store a computer program, and the processor being configured to execute the computer program to enable the electronic device to perform the high-pressure direct-injection gas transient mass flow rate test method of embodiment 1.

[0083] Optionally, the electronic device can be a server.

[0084] In addition, the embodiment of the present application also provides a computer readable storage medium storing a computer program, which, when executed by a processor, implements the high-pressure direct-injection gas transient mass flow rate test method of embodiment 1.

[0085] Embodiments of the present application can be provided as a method, a system, or a computer program product. Therefore, the present application can take the form of an entirely hardware embodiment, an entirely software embodiment, or an embodiment combining software and hardware aspects. Moreover, the present application can take the form of a computer program product implemented on one or more computer-usable storage media (including, but not limited to, disk storage, CD-ROMs, optical storage media, etc.) containing computer-usable program code.

[0086] The present application is described with reference to flowcharts and / or block diagrams of the method, device (system) and computer program product according to embodiments of the present application. It should be understood that each flow and / or block in the flowcharts and / or block diagrams, as well as combinations of flows and / or blocks in the flowcharts and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing apparatus to produce a machine, so that the instructions executed by the processor of the computer or other programmable data processing apparatus produce a device that implements the functions specified in the flowcharts and / or block diagrams. Figure 1 The function specified in one flow or multiple flows and / or blocks Figure 1 The device that implements the function specified in one block or multiple blocks.

[0087] These computer program instructions can also be stored in a computer readable memory that can direct a computer or other programmable data processing apparatus to function in a particular manner, such that the instructions stored in the computer readable memory produce an article of manufacture including instructions which implement the flow Figure 1 The functions of a flow or multiple flows and / or a block or multiple blocks in conjunction with the disclosed methods can be implemented on practitioners' computers in computer software, firmware, hardware, or combinations of them. Figure 1

[0088] These computer program instructions can also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer implemented process such that the instructions which execute on the computer or other programmable apparatus provide steps for implementing the functions specified in the flow Figure 1 The functions of a flow or multiple flows and / or a block or multiple blocks in conjunction with the disclosed methods can be implemented on practitioners' computers in computer software, firmware, hardware, or combinations of them. Figure 1

[0089] The principles and implementations of the present application have been described above with the specific examples. The above description of the embodiments is only for the purpose of understanding the method of the present application and its core idea; meanwhile, for those skilled in the art, according to the idea of the present application, the specific implementation and application range can be changed. In summary, the content of the present description should not be understood as a limitation of the present application.​​

Claims

1. A method for testing the transient mass flow rate of high-pressure direct-injection gas, characterized in that, The method includes: The fuel injection rate is obtained by measuring the fuel mass flow meter, which is located upstream of the fuel injector's gas inlet. The pressure data at the fuel injector nozzle outlet measured by the force sensor is acquired; the force sensor is located at the fuel injector nozzle outlet. Based on the pressure data, the momentum method is applied and combined with the fuel injection rate to derive the transient mass flow rate of the combustion gas. The transient mass flow rate of the combustion gas is derived by applying the momentum method based on the pressure data and combining it with the fuel injection rate. Specifically, this includes: The shape of the jet propulsion curve is derived from the pressure data and the momentum theorem. The fuel injection quantity and the shape of the injection pattern curve are calibrated to obtain the transient mass flow rate of the gas.

2. The method according to claim 1, characterized in that, The expression corresponding to the curve shape of the gas mass flow rate is: Where F(t) represents the pressure data; This indicates the gas mass flow rate.

3. A high-pressure direct injection gas transient mass flow rate testing system, used to perform the high-pressure direct injection gas transient mass flow rate testing method according to any one of claims 1 to 2, characterized in that, The system includes: A fuel injection quantity acquisition module is used to acquire the fuel injection quantity measured by a gas mass flow meter; the gas mass flow meter is located upstream of the fuel injector's gas inlet. A jet pressure acquisition module is used to acquire pressure data at the outlet of the fuel injector nozzle measured by a force sensor; the force sensor is located at the outlet of the fuel injector nozzle. The mass flow rate testing module is used to derive the transient mass flow rate of the gas combustion gas by applying the momentum method based on the pressure data and combining it with the fuel injection quantity.

4. A device for testing the transient mass flow rate of high-pressure direct-injection gas, characterized in that, The device includes: a gas mass flow meter, a pneumatic sensor, a fuel injector, and a test module; The gas mass flow meter is located upstream of the fuel inlet of the fuel injector; The pneumatic sensor is located at the nozzle outlet of the fuel injector; The test module is connected to the gas mass flow meter and the pneumatic sensor respectively, and is used to perform the high-pressure direct injection gas transient mass flow rate test method according to any one of claims 1 to 2.

5. The high-pressure direct injection gas transient mass flow rate testing device according to claim 4, characterized in that, The device also includes: a gas storage tank, an oil storage tank, and a constant volume container; The fuel injector nozzle ejects the fuel gas into the constant volume container; The gas storage tank is connected to the fuel inlet of the fuel injector via a compressor, a pressure control device, and a gas rail in sequence; the gas mass flow meter is installed on the pipeline connecting the gas rail and the fuel inlet of the fuel injector. The oil storage tank is connected to the fuel inlet of the fuel injector via an oil pump and an oil rail.

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