Online measurement method and device for unburned methanol and formaldehyde emission of methanol engine

Abstract

The invention relates to the technical field of methanol engines, in particular to an online measurement method and device for unburned methanol and formaldehyde emission of a methanol engine, and the method comprises the steps: obtaining the instantaneous volume concentration of unburned methanol and formaldehyde in the tail gas of the methanol engine when the methanol engine operates under a target test working condition; according to the instantaneous volume concentration and the instantaneous target u value of the unburned methanol and the formaldehyde of the methanol engine, the emission mass of the unburned methanol and the emission mass of the formaldehyde are calculated; and the actual circulation work of the methanol engine is determined through the instantaneous power of the methanol engine, and the specific emission amount of the unburned methanol and the formaldehyde is determined according to the emission quality of the unburned methanol and the formaldehyde and the actual circulation work. Therefore, the problems that the test period is greatly prolonged, the test efficiency is reduced, the detection cost is remarkably increased and the development requirements of industries and enterprises on the short period and low cost of the methanol engine cannot be met due to the fact that the emission amount of unconventional pollutants is detected through off-line measurement in related technologies are solved.

Description

Technical Field

[0001] The present application relates to the technical field of methanol engines, and in particular to an online measurement method and device for unburned methanol and formaldehyde emissions from a methanol engine. Background Art

[0002] Green methanol (CH3OH), as a low-carbon fuel, is one of the most important carbon-neutral fuels in the future technology route of the engine and vehicle industry. Compared with traditional gasoline and diesel, when the engine burns methanol fuel, unconventional gaseous pollutants such as unburned methanol and formaldehyde (HCHO) will be produced in the exhaust gas, and the current emission control is difficult. Unconventional emissions are one of the main technical bottlenecks facing the development of methanol engine products. Therefore, in the early stage of methanol engine research and development and verification, researchers need to understand the emissions of unburned methanol and formaldehyde in the exhaust gas in real time, so as to adjust the engine combustion parameters in time to achieve pollutant emission control.

[0003] In related technologies, both methanol and formaldehyde are measured offline. During the test, an air bag is used to collect the engine exhaust gas, and then offline measurements are performed on laboratory instruments. The unburned methanol is measured by solid phase adsorption / headspace-gas chromatography-mass spectrometry, and the formaldehyde is measured by high performance liquid chromatography.

[0004] However, in related technologies, the use of offline measurement to detect emissions of unconventional pollutants will lead to a significant extension of the test cycle, a reduction in test efficiency, and a significant increase in detection costs. This cannot meet the industry's requirements for short-cycle and low-cost development of methanol engines, and needs to be urgently resolved. Summary of the invention

[0005] The present application provides an online measurement method and device for unburned methanol and formaldehyde emissions of a methanol engine, in order to solve the problem that the related art uses offline measurement to detect the emission of unconventional pollutants, which leads to a significant extension of the test cycle, a reduction in test efficiency, and a significant increase in detection costs, and cannot meet the industry's requirements for short-cycle and low-cost development of methanol engines.

[0006] The first aspect of the present application provides an online measurement method for unburned methanol and formaldehyde emissions from a methanol engine, comprising the following steps: when the methanol engine is operating under target test conditions, obtaining the instantaneous volume concentration of unburned methanol and formaldehyde in the exhaust gas of the methanol engine; calculating the emission mass of the unburned methanol and formaldehyde based on the instantaneous volume concentration and the target instantaneous u value of the unburned methanol and formaldehyde of the methanol engine; determining the actual cycle work of the methanol engine using the instantaneous power of the methanol engine, so as to determine the specific emissions of the unburned methanol and formaldehyde based on the emission mass of the unburned methanol and formaldehyde and the actual cycle work.

[0007] Optionally, in one embodiment of the present application, before collecting the instantaneous volume concentration of unburned methanol and formaldehyde in the exhaust gas of the methanol engine, it also includes: detecting a target exhaust gas sampling method for unburned methanol and formaldehyde of the methanol engine; determining the target test condition of the methanol engine according to the target exhaust gas sampling method, and calculating the u value of the unburned methanol and formaldehyde of the methanol engine in the target test condition.

[0008] Optionally, in one embodiment of the present application, obtaining the instantaneous volume concentration of unburned methanol and formaldehyde in the exhaust gas of the methanol engine includes: using zero gas and span gas to perform response detection on a Fourier transform infrared spectrometer gas analyzer so that the Fourier transform infrared spectrometer gas analyzer meets preset calibration conditions; and using the Fourier transform infrared spectrometer gas analyzer that meets the preset calibration conditions to measure the instantaneous volume concentration of unburned methanol and formaldehyde in the exhaust gas of the methanol engine.

[0009] Optionally, in one embodiment of the present application, the calculation of the actual cycle work of the methanol engine using the instantaneous power of the methanol engine includes: determining the instantaneous power of the methanol engine using the instantaneous speed and instantaneous torque of the methanol engine; and calculating the actual cycle work of the methanol engine based on the instantaneous power.

[0010] Optionally, in one embodiment of the present application, the formula for calculating the specific emission of unburned methanol and formaldehyde is:

[0011]

[0012] Among them, e gas is the specific emission of unburned methanol and formaldehyde; m gas is the emission mass of unburned methanol and formaldehyde; W acy is the actual cycle work.

[0013] The second aspect of the present application provides an online measurement device for unburned methanol and formaldehyde emissions from a methanol engine, comprising: an acquisition module, used to acquire the instantaneous volume concentration of unburned methanol and formaldehyde in the exhaust gas of the methanol engine when the methanol engine is operating under target test conditions; a calculation module, used to calculate the emission mass of the unburned methanol and formaldehyde based on the instantaneous volume concentration and the target instantaneous u value of the unburned methanol and formaldehyde of the methanol engine; a measurement module, used to determine the actual cycle work of the methanol engine using the instantaneous power of the methanol engine, so as to determine the specific emissions of the unburned methanol and formaldehyde based on the emission mass of the unburned methanol and formaldehyde and the actual cycle work.

[0014] Optionally, in one embodiment of the present application, the device of the embodiment of the present application also includes: a detection module, used to detect a target exhaust gas sampling mode of unburned methanol and formaldehyde of the methanol engine before collecting the instantaneous volume concentration of unburned methanol and formaldehyde in the exhaust gas of the methanol engine; a determination module, used to determine the target test condition of the methanol engine according to the target exhaust gas sampling mode before collecting the instantaneous volume concentration of unburned methanol and formaldehyde in the exhaust gas of the methanol engine, and calculate the u value of unburned methanol and formaldehyde of the methanol engine in the target test condition.

[0015] Optionally, in one embodiment of the present application, the acquisition module includes: a detection unit, used to use zero gas and span gas to perform response detection on the Fourier transform infrared spectrometer gas analyzer, so that the Fourier transform infrared spectrometer gas analyzer meets preset calibration conditions; a measurement unit, used to measure the instantaneous volume concentration of unburned methanol and formaldehyde in the exhaust gas of the methanol engine using the Fourier transform infrared spectrometer gas analyzer that meets the preset calibration conditions.

[0016] Optionally, in one embodiment of the present application, the measurement module includes: a determination unit for determining the instantaneous power of the methanol engine using the instantaneous speed and instantaneous torque of the methanol engine; and a calculation unit for calculating the actual cycle work of the methanol engine based on the instantaneous power.

[0017] Optionally, in one embodiment of the present application, the formula for calculating the specific emission of unburned methanol and formaldehyde is:

[0018]

[0019] Among them, e gas is the specific emission of unburned methanol and formaldehyde; m gas is the emission mass of unburned methanol and formaldehyde; W act is the actual cycle work.

[0020] The third aspect of the present application provides an electronic device, comprising: a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the program to implement the online measurement method of unburned methanol and formaldehyde emissions of a methanol engine as described in the above embodiment.

[0021] The fourth aspect of the present application provides a computer-readable storage medium, which stores a computer program. When the program is executed by a processor, it implements the above-mentioned online measurement method of unburned methanol and formaldehyde emissions of a methanol engine.

[0022] The fifth aspect of the present application provides a computer program product, including a computer program, which, when executed, is used to implement the above-mentioned online measurement method of unburned methanol and formaldehyde emissions of a methanol engine.

[0023] The embodiment of the present application can calculate the emission mass of unburned methanol and formaldehyde according to the instantaneous volume concentration of unburned methanol and formaldehyde in the exhaust gas of the methanol engine and the instantaneous target u value of unburned methanol and formaldehyde when the methanol engine is running under the target test conditions, thereby determining the specific emission of unburned methanol and formaldehyde according to the emission mass of unburned methanol and formaldehyde and the actual cycle work, effectively reducing the detection cost and improving the real-time and accuracy of the detection. Thus, the problem that the use of offline measurement to detect the emission of unconventional pollutants in the related technology will lead to a significant extension of the test cycle, a reduction in test efficiency, and a significant increase in detection costs, which cannot meet the industry enterprises' requirements for the short cycle and low cost development of methanol engines is solved.

[0024] Additional aspects and advantages of the present application will be given in part in the description below, and in part will become apparent from the description below, or will be learned through the practice of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] The above and / or additional aspects and advantages of the present application will become apparent and easily understood from the following description of the embodiments in conjunction with the accompanying drawings, in which:

[0026] Figure 1 A schematic diagram of an online measurement system for unburned methanol and formaldehyde emissions of a methanol engine provided according to an embodiment of the present application;

[0027] Figure 2 A flow chart of an online measurement method for unburned methanol and formaldehyde emissions of a methanol engine provided according to an embodiment of the present application;

[0028] Figure 3 It is a structural schematic diagram of an online measurement device for unburned methanol and formaldehyde emissions of a methanol engine provided according to an embodiment of the present application;

[0029] Figure 4 It is a schematic diagram of the structure of an electronic device provided according to an embodiment of the present application. DETAILED DESCRIPTION

[0030] Embodiments of the present application are described in detail below, and examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the present application, and should not be construed as limiting the present application.

[0031] The following describes the online measurement method and device of the unburned methanol and formaldehyde emissions of the methanol engine of the embodiment of the present application with reference to the accompanying drawings. In view of the problem that the related art mentioned in the above background technology adopts offline measurement to detect the emission of unconventional pollutants, which will lead to a significant extension of the test cycle, a reduction in test efficiency, and a significant increase in detection costs, and cannot meet the industry enterprises' short-cycle and low-cost development requirements for methanol engines, the present application provides an online measurement method for the unburned methanol and formaldehyde emissions of a methanol engine, in which the emission mass of unburned methanol and formaldehyde can be calculated according to the instantaneous volume concentration of unburned methanol and formaldehyde in the exhaust gas of the methanol engine and the instantaneous target u value of unburned methanol and formaldehyde when the methanol engine is running under the target test condition, so as to determine the specific emission of unburned methanol and formaldehyde according to the emission mass of unburned methanol and formaldehyde and the actual cycle work, effectively reducing the detection cost and improving the real-time and accuracy of the detection. Thus, the problem that the related art adopts offline measurement to detect the emission of unconventional pollutants, which will lead to a significant extension of the test cycle, a reduction in test efficiency, and a significant increase in detection costs, cannot meet the industry enterprises' short-cycle and low-cost development requirements for methanol engines.

[0032] The present application embodiment provides an online measurement system for unburned methanol and formaldehyde emissions from a methanol engine, specifically, Figure 1 As shown, the system includes a dynamometer system 1, a methanol engine 2, an intake mass flow meter 3, an intake temperature and humidity sensor 4, a methanol fuel tank 5, a fuel consumption meter 6, a post-processing system 7, a Fourier transform infrared spectrometer gas analyzer 8 (if the exhaust gas sampling method selects full-flow dilution system sampling, the sampling pipeline is installed in the full-flow dilution system 9); full-flow dilution system 9 (used when the exhaust gas sampling method selects full-flow dilution system sampling).

[0033] Among them, Figure 1 As shown, the intake system (3, 4), methanol supply system (5, 6), and after-treatment system (7) are correctly connected to the methanol engine (2) to ensure that there is no obvious leakage at the connection of each pipeline. In addition, the installation position of the sensor of each key measurement parameter of the test bench is carried out in accordance with the current standards or enterprise requirements.

[0034] Specifically, Figure 2 A schematic flow chart of an online measurement method for unburned methanol and formaldehyde emissions from a methanol engine provided in an embodiment of the present application.

[0035] like Figure 2 As shown, the online measurement method for unburned methanol and formaldehyde emissions of a methanol engine comprises the following steps:

[0036] In step S201, when the methanol engine is running under the target test condition, the instantaneous volume concentrations of unburned methanol and formaldehyde in the exhaust gas of the methanol engine are obtained.

[0037] In an embodiment of the present application, the target test conditions can be determined based on the exhaust gas sampling method for emission measurement, wherein the exhaust gas sampling method for emission measurement is divided into original exhaust sampling measurement and full-flow dilution system sampling measurement. The embodiment of the present application can determine the corresponding exhaust gas sampling method based on field test conditions and test requirements before the test.

[0038] It can be understood that the embodiments of the present application can obtain the instantaneous volume concentration of unburned methanol and formaldehyde in the exhaust gas of a methanol engine when the methanol engine is operating under the target test conditions. For example, a Fourier transform infrared spectroscopy gas analyzer can be used to measure the volume concentration of unburned methanol and formaldehyde in the exhaust gas throughout the test, thereby effectively improving the feasibility of online measurement of unburned methanol and formaldehyde emissions.

[0039] Optionally, in one embodiment of the present application, before collecting the instantaneous volume concentration of unburned methanol and formaldehyde in the exhaust gas of the methanol engine, it also includes: detecting a target exhaust gas sampling method for unburned methanol and formaldehyde of the methanol engine; determining a target test condition of the methanol engine according to the target exhaust gas sampling method, and calculating the u value of the unburned methanol and formaldehyde of the methanol engine in the target test condition.

[0040] In the actual implementation process, the embodiment of the present application can detect the target exhaust gas sampling method of unburned methanol and formaldehyde of the methanol engine, wherein the target exhaust gas sampling method, that is, the emission measurement exhaust gas sampling method is divided into original exhaust sampling measurement and full-flow dilution system sampling measurement; then, the target test condition of the methanol engine can be determined according to the target exhaust gas sampling method. For example, in order to maximize the use of existing standard resources and facilitate the comparison of emission levels between different methanol engine products, the test method and system in the embodiment of the present application do not need to establish new test conditions, and the standard test cycle specified in the current standard will be used as the test condition for testing. For example, the test condition can adopt WHTC (World Harmonized Transient Cycle) or China Engine Transient Test Condition.

[0041] For example, Figure 1 As shown, assuming that the measurement of unburned methanol and formaldehyde in the exhaust gas of the methanol engine adopts the original exhaust sampling measurement, the Fourier transform infrared spectrometer gas analyzer 8 in the installation test system is installed in the exhaust pipe downstream of the aftertreatment, and the full-flow dilution system 9 is not used. The sensor installation positions of the key measurement parameters of the test bench are carried out in accordance with the current standards or enterprise requirements. In addition, the test condition adopts the WHTC transient cycle specified in the current standards.

[0042] It should be noted that the embodiment of the present application will use the emission measurement tail gas sampling method as the original exhaust sampling measurement, and the test condition will be described in detail using the WHTC transient cycle specified in the current standard.

[0043] Furthermore, for the original exhaust sampling measurement of methanol engines, when calculating the emission mass of unburned methanol and formaldehyde, the current standard does not give the u value of unburned methanol and formaldehyde. Referring to the current standard, for the original exhaust sampling measurement, the u value of unburned methanol and formaldehyde (i.e., the exhaust component density and exhaust density ratio) is calculated according to the following formula:

[0044]

[0045] Among them, M gas is the molar mass of unburned methanol and formaldehyde, in grams per mole, g / mol; M e,i is the instantaneous molar mass of the exhaust gas, in grams per mole, g / mol.

[0046] Among them, the instantaneous molar mass of exhaust gas M e,i According to the general fuel composition formula CH α O ε N δ S γ Calculate according to the following formula:

[0047]

[0048] Among them, q mf,i is the instantaneous mass flow rate of fuel, in kilograms per second, kg / s; q maw,i is the instantaneous mass flow rate of wet-based intake air, in kilograms per second, kg / s; H a is the absolute humidity of the inlet air, expressed in grams of water per kilogram of dry air, g / kg, which can be calculated using the general equation from the relative humidity measurement, dew point measurement, vapor pressure measurement or dry / wet bulb thermometer measurement; M a is the molar mass of the feed gas on a dry basis in grams per mole, g / mol, which is 28.965 g / mol here.

[0049] In addition, for full-flow dilution system sampling measurement, the u value of unburned methanol and formaldehyde (i.e., the ratio of exhaust component density to diluted exhaust density) is calculated according to the following formula:

[0050]

[0051] Among them, M d is the molar mass of the diluted exhaust gas in grams per mole, g / mol, which is 28.965 g / mol here.

[0052] Therefore, the embodiment of the present application can propose different u values ​​required for the calculation of the emission mass of unburned methanol and formaldehyde according to different emission measurement exhaust gas sampling methods, and can realize the online measurement of the unburned methanol and formaldehyde emission ratio of the methanol engine, which greatly shortens the detection time of unburned methanol and formaldehyde and improves the test efficiency.

[0053] Among them, in one embodiment of the present application, the instantaneous volume concentration of unburned methanol and formaldehyde in the exhaust gas of a methanol engine is obtained, including: using zero gas and span gas to perform response detection on a Fourier transform infrared spectroscopy gas analyzer so that the Fourier transform infrared spectroscopy gas analyzer meets preset calibration conditions; using the Fourier transform infrared spectroscopy gas analyzer that meets the preset calibration conditions to measure the instantaneous volume concentration of unburned methanol and formaldehyde in the exhaust gas of a methanol engine.

[0054] For example, assuming that the measurement of unburned methanol and formaldehyde in the exhaust gas of a methanol engine is measured using original exhaust sampling, and the test condition uses the WHTC transient cycle specified in the current standard, the embodiment of the present application can run the engine to the rated point condition after the engine is run-in according to the requirements of the enterprise, adjust the boundary conditions according to the current standards or enterprise requirements, and then perform a net power performance check to ensure that it meets the requirements of the current standards. After the performance check is completed, the engine is shut down and cooled naturally until the coolant temperature, lubricating oil temperature, and post-processing core temperature are lower than 30°C.

[0055] Secondly, before the test, the response check of the Fourier transform infrared spectrometer gas analyzer can be carried out with zero gas and methanol and formaldehyde span gases to calibrate the Fourier transform infrared spectrometer gas analyzer. After that, the engine can be started and the WHTC cold test cycle and WHTC hot test cycle can be run, during which the heat soak is 10 minutes and the data acquisition frequency is 10Hz. During the hot soak stage or within 30 minutes after the end of the test cycle, the response check of the zero gas and span gas of the Fourier transform infrared spectrometer gas analyzer can be carried out to ensure that the deviation before and after the test does not exceed 2% of the full scale specified in the current standard.

[0056] In step S202, the emission masses of unburned methanol and formaldehyde are calculated based on the instantaneous volume concentration and the target instantaneous u-values ​​of unburned methanol and formaldehyde of the methanol engine.

[0057] It can be understood that the embodiment of the present application can calculate the emission mass of unburned methanol and formaldehyde according to the instantaneous volume concentration and the target instantaneous u value of unburned methanol and formaldehyde of the methanol engine. For example, assuming that the measurement of unburned methanol and formaldehyde in the exhaust gas of the methanol engine adopts the original exhaust sampling measurement, and the test condition adopts the WHTC transient cycle specified in the current standard, the instantaneous u value of unburned methanol and formaldehyde is calculated according to the transient data of the WHTC test cycle, and the calculation is as follows:

[0058]

[0059] Among them, the instantaneous molar mass of exhaust gas M e,i According to the general fuel composition formula CH α O ε N δ S γ Calculate according to the following formula:

[0060]

[0061] Among them, q mf,i is the instantaneous mass flow rate of fuel, in kilograms per second, kg / s, measured by the fuel consumption meter 6 in the above-mentioned measurement system in the test; q maw,i is the instantaneous mass flow rate of wet-based intake air, in kilograms per second, kg / s, which is measured by the intake air mass flow meter 3 in the above-mentioned measurement system in the test; H a is the intake air humidity, expressed in grams of water per kilogram of dry air, g / kg; M a is the molar mass of the dry intake air, in grams per mole, g / mol, which is 28.965 g / mol here; the test fuel is M100 automotive methanol fuel, with a methanol mass fraction of more than 99.99%, so it is assumed that the general fuel composition formula is CH α O ε N δ S γ It is CHO, that is, α=4, ε=1, δ=γ=0.

[0062]

[0063] Among them, R a is the relative humidity of the intake air, in percentage, %, measured by the intake air temperature and humidity sensor 4 in the above-mentioned measurement system in the test; P a is the intake saturated vapor pressure, in kilopascals, kPa, which can be obtained by looking up the table from the measured intake temperature in the test; P B It is atmospheric pressure, measured in kilopascals (kPa). It is obtained by adding the ambient pressure measured by the bench pressure sensor and the intake pressure during the test.

[0064] It should be noted that the relative atomic masses of the elements used in the calculations in the examples of the present application are: C: 12.011; H: 1.00794; N: 14.0067; O: 15.9994; S: 32.065.

[0065] Furthermore, the emission mass of unburned methanol and formaldehyde in the whole WHTC test cycle is:

[0066]

[0067] Among them, m gasis the emission mass of unburned methanol and formaldehyde in the WHTC test cycle, in milligrams per cycle, mg / test; u gas,i is the instantaneous u value of unburned methanol and formaldehyde calculated above, dimensionless number; C gas,i is the instantaneous volume concentration of unburned methanol and formaldehyde in the original exhaust gas, in parts per million, 10 -6 , measured by the Fourier transform infrared spectroscopy gas analyzer in the experiment; q mew,i is the instantaneous exhaust mass flow rate in kilograms per second, kg / s, which is obtained by adding the intake mass flow rate and the fuel mass flow rate in the test; f is the data acquisition frequency in Hertz, Hz, which is set to 10 Hz here; n is the number of data records, the WHTC test cycle duration is 1800s, based on the data acquisition frequency of 10 Hz, here n = 18000.

[0068] The following table shows an example table of transient test data related to the calculation of unburned methanol and formaldehyde emissions in the WHTC test cycle. The specific table 1 is as follows:

[0069] Table 1

[0070]

[0071] After calculation, the emission masses of unburned methanol and formaldehyde in the WHTC cold test cycle and the WHTC hot test cycle are:

[0072]

[0073] m HCHO,cold =298mg

[0074] m HCHO,hot =12mg

[0075] in, The emission mass of unburned methanol in the WHTC cold test cycle, in milligrams, mg; is the emission mass of unburned methanol in the WHTC hot test cycle, in milligrams, mg; m HCHO,cold It is the emission mass of formaldehyde in the WHTC cold test cycle, in milligrams, mg; m HCHO,hot It is the formaldehyde emission mass in the WHTC hot test cycle, in milligrams, mg.

[0076] In the embodiment of the present application, full utilization of existing standard resources can be achieved. The test conditions adopt the conventional pollutant emission test cycle specified in the current standards. No additional tests are required, and the simultaneous testing of unburned methanol and formaldehyde emissions and conventional pollutant emissions can be achieved.

[0077] In step S203, the actual cycle work of the methanol engine is determined using the instantaneous power of the methanol engine, so as to determine the specific emission of unburned methanol and formaldehyde according to the emission masses of unburned methanol and formaldehyde and the actual cycle work.

[0078] It can be understood that the embodiments of the present application can use the instantaneous power of the methanol engine to determine the actual cycle work of the methanol engine. For example, the actual cycle work of the entire WHTC test cycle is obtained by integrating the instantaneous power, so as to determine the specific emissions of unburned methanol and formaldehyde based on the emission mass of unburned methanol and formaldehyde and the actual cycle work, thereby enabling online measurement of the specific emissions of unburned methanol and formaldehyde of the methanol engine, greatly shortening the detection time of unburned methanol and formaldehyde, improving test efficiency, and reducing detection costs.

[0079] Among them, in one embodiment of the present application, the instantaneous power of the methanol engine is used to calculate the actual cycle work of the methanol engine, including: determining the instantaneous power of the methanol engine using the instantaneous speed and instantaneous torque of the methanol engine; and calculating the actual cycle work of the methanol engine based on the instantaneous power.

[0080] For example, assuming that the measurement of unburned methanol and formaldehyde in the exhaust gas of a methanol engine is measured by original exhaust sampling, and the test condition adopts the WHTC transient cycle specified in the current standard, the instantaneous speed and instantaneous torque of the methanol engine can be used to determine the instantaneous power of the methanol engine, that is, the actual cycle work of the entire WHTC test cycle is obtained by integrating the instantaneous power, that is:

[0081]

[0082] Among them, W act is the actual cycle work of the WHTC test cycle, in kilowatt-hours, kW·h; P e is the instantaneous power of the engine, in kilowatts, kW; T e is the instantaneous torque of the engine, in Newton-meters (Nm). All negative torque values ​​in the test are set to 0; n e is the instantaneous engine speed, in revolutions per minute, r·min -1 .

[0083] After calculation, the actual cycle work of the WHTC cold test cycle and the WHTC hot test cycle are:

[0084] W act,cold =17.830kW·h

[0085] W act,hot =17.695kW·h

[0086] Among them, W act,coldis the actual cycle work of the WHTC cold test cycle, in kilowatt-hours, kW·h; W act,hot It is the actual cycle work of the WHTC hot test cycle, in kilowatt-hours, kW·h.

[0087] Next, the specific emissions of unburned methanol and formaldehyde in the entire WHTC test cycle are:

[0088]

[0089] Among them, e gas is the specific emission of unburned methanol and formaldehyde, in milligrams per kilowatt-hour, mg / kW·h; m gas is the emission mass of unburned methanol and formaldehyde in the WHTC test cycle, in milligrams per cycle, mg / test; W act It is the actual cycle work of the WHTC test cycle, in kilowatt-hours, kW·h.

[0090] Furthermore, the weighted ratio of unburned methanol and formaldehyde emissions in the hot and cold WHTC test cycle is:

[0091]

[0092] Where, e is the weighted ratio of unburned methanol and formaldehyde emissions in the hot and cold WHTC test cycle, in milligrams per kilowatt-hour, mg / kW·h; m cold is the emission mass of unburned methanol and formaldehyde in the cold start cycle, in milligrams per cycle, mg / test; m hot is the emission mass of unburned methanol and formaldehyde in the hot start cycle, in milligrams per cycle, mg / test; W act,cold is the actual cycle work of the cold start cycle, in kilowatt-hours, kW·h; W act,hot It is the actual cycle work of the hot start cycle, in kilowatt-hours, kW·h.

[0093] After calculation, the weighted ratio emissions of unburned methanol and formaldehyde in the hot and cold WHTC test cycles are:

[0094]

[0095] in, is the weighted specific emission of unburned methanol in the hot and cold WHTC test cycle, in milligrams per kilowatt-hour, mg / kW·h; e HCHO It is the weighted specific formaldehyde emission in the hot and cold WHTC test cycle, expressed in milligrams per kilowatt-hour, mg / kW·h.

[0096] Therefore, the test method and system of the present application can maximize the use of existing standard test cycles, realize the simultaneous testing of conventional pollutants and unconventional pollutants, realize the online continuous measurement of unburned methanol and formaldehyde emissions of methanol engines, and convert them into pollutant specific emissions (g / kW·h), thereby providing important support for researchers to timely understand and grasp the unburned methanol and formaldehyde emission levels, significantly improving the efficiency of methanol engine testing, shortening the product development cycle, and greatly reducing testing costs.

[0097] According to the online measurement method of unburned methanol and formaldehyde emissions of a methanol engine proposed in the embodiment of the present application, the emission mass of unburned methanol and formaldehyde can be calculated according to the instantaneous volume concentration of unburned methanol and formaldehyde in the exhaust gas of the methanol engine and the instantaneous target u value of unburned methanol and formaldehyde when the methanol engine is running under the target test conditions, thereby determining the specific emission of unburned methanol and formaldehyde according to the emission mass of unburned methanol and formaldehyde and the actual cycle work, effectively reducing the detection cost and improving the real-time and accuracy of the detection. Thus, the problem that the use of offline measurement to detect the emission of unconventional pollutants in the related art will lead to a significant extension of the test cycle, a reduction in test efficiency, and a significant increase in detection costs, which cannot meet the industry enterprises' requirements for the short cycle and low cost development of methanol engines is solved.

[0098] Next, an online measurement device for unburned methanol and formaldehyde emissions of a methanol engine proposed in an embodiment of the present application will be described with reference to the accompanying drawings.

[0099] Figure 3 It is a block diagram of an online measurement device for unburned methanol and formaldehyde emissions of a methanol engine according to an embodiment of the present application.

[0100] like Figure 3 As shown, the online measurement device 10 for unburned methanol and formaldehyde emissions of a methanol engine includes: an acquisition module 100 , a calculation module 200 and a measurement module 300 .

[0101] Specifically, the acquisition module 100 is used to acquire the instantaneous volume concentration of unburned methanol and formaldehyde in the exhaust gas of the methanol engine when the methanol engine is running under the target test condition.

[0102] The calculation module 200 is used to calculate the emission mass of unburned methanol and formaldehyde according to the instantaneous volume concentration and the target instantaneous u value of the unburned methanol and formaldehyde of the methanol engine.

[0103] The measurement module 300 is used to determine the actual cycle work of the methanol engine using the instantaneous power of the methanol engine, so as to determine the specific emission of unburned methanol and formaldehyde according to the emission mass of unburned methanol and formaldehyde and the actual cycle work.

[0104] Optionally, in one embodiment of the present application, the device 10 of the embodiment of the present application further includes: a detection module and a determination module.

[0105] Among them, the detection module is used to detect the target exhaust gas sampling method of unburned methanol and formaldehyde in the methanol engine before collecting the instantaneous volume concentration of unburned methanol and formaldehyde in the exhaust gas of the methanol engine.

[0106] The determination module is used to determine the target test condition of the methanol engine according to the target exhaust gas sampling method before collecting the instantaneous volume concentration of unburned methanol and formaldehyde in the exhaust gas of the methanol engine, and calculate the u value of unburned methanol and formaldehyde of the methanol engine in the target test condition.

[0107] Optionally, in one embodiment of the present application, the acquisition module 100 includes: a detection unit and a measurement unit.

[0108] Among them, the detection unit is used to use zero gas and span gas to perform response detection on the Fourier transform infrared spectroscopy gas analyzer, so that the Fourier transform infrared spectroscopy gas analyzer meets the preset calibration conditions.

[0109] The measuring unit is used to measure the instantaneous volume concentration of unburned methanol and formaldehyde in the exhaust gas of a methanol engine by using a Fourier transform infrared spectrometer gas analyzer that meets preset calibration conditions.

[0110] Optionally, in one embodiment of the present application, the measurement module 300 includes: a determination unit and a calculation unit.

[0111] The determination unit is used to determine the instantaneous power of the methanol engine by using the instantaneous speed and instantaneous torque of the methanol engine.

[0112] A calculation unit is used to calculate the actual cycle work of the methanol engine based on the instantaneous power.

[0113] Optionally, in one embodiment of the present application, the formula for calculating the specific emission of unburned methanol and formaldehyde is:

[0114]

[0115] Among them, e gas is the specific emission of unburned methanol and formaldehyde; m gas is the emission mass of unburned methanol and formaldehyde; W act is the actual cycle work.

[0116] It should be noted that the above explanation of the embodiment of the online measurement method for unburned methanol and formaldehyde emissions of a methanol engine is also applicable to the online measurement device for unburned methanol and formaldehyde emissions of a methanol engine of this embodiment, and will not be repeated here.

[0117] According to the online measurement device for unburned methanol and formaldehyde emissions from a methanol engine proposed in the embodiment of the present application, the emission mass of unburned methanol and formaldehyde can be calculated according to the instantaneous volume concentration of unburned methanol and formaldehyde in the exhaust gas of the methanol engine and the instantaneous target u value of unburned methanol and formaldehyde when the methanol engine is running under the target test conditions, thereby determining the specific emission of unburned methanol and formaldehyde according to the emission mass of unburned methanol and formaldehyde and the actual cycle work, effectively reducing the detection cost and improving the real-time and accuracy of the detection. Thus, the problem that the use of offline measurement to detect the emission of unconventional pollutants in the related art will lead to a significant extension of the test cycle, a reduction in test efficiency, and a significant increase in detection costs, which cannot meet the industry enterprises' requirements for the short cycle and low cost development of methanol engines is solved.

[0118] Figure 4 A schematic diagram of the structure of an electronic device provided in an embodiment of the present application. The electronic device may include:

[0119] Memory 401 , processor 402 , and a computer program stored in the memory 401 and executable on the processor 402 .

[0120] When the processor 402 executes the program, the online measurement method for unburned methanol and formaldehyde emissions of a methanol engine provided in the above embodiment is implemented.

[0121] Furthermore, the electronic device further comprises:

[0122] The communication interface 403 is used for communication between the memory 401 and the processor 402 .

[0123] The memory 401 is used to store computer programs that can be executed on the processor 402 .

[0124] The memory 401 may include a high-speed RAM memory, and may also include a non-volatile memory (non-volatile memory), such as at least one disk memory.

[0125] If the memory 401, the processor 402 and the communication interface 403 are implemented independently, the communication interface 403, the memory 401 and the processor 402 can be connected to each other through a bus and communicate with each other. The bus can be an Industry Standard Architecture (ISA) bus, a Peripheral Component Interconnect (PCI) bus or an Extended Industry Standard Architecture (EISA) bus. The bus can be divided into an address bus, a data bus, a control bus, etc. For ease of representation, Figure 4 Only one thick line is used in the diagram, but this does not mean that there is only one bus or only one type of bus.

[0126] Optionally, in a specific implementation, if the memory 401, the processor 402 and the communication interface 403 are integrated on a chip, the memory 401, the processor 402 and the communication interface 403 can communicate with each other through an internal interface.

[0127] The processor 402 may be a central processing unit (CPU), or an application specific integrated circuit (ASIC), or one or more integrated circuits configured to implement the embodiments of the present application.

[0128] This embodiment also provides a computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the above-mentioned online measurement method for unburned methanol and formaldehyde emissions of a methanol engine.

[0129] This embodiment also provides a computer program product, including a computer program, which, when executed, is used to implement the above-mentioned online measurement method for unburned methanol and formaldehyde emissions of a methanol engine.

[0130] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present application. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or N embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, without contradiction.

[0131] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include at least one of the features. In the description of this application, "N" means at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0132] Any process or method description in a flowchart or otherwise described herein may be understood to represent a module, fragment or portion of code comprising one or N executable instructions for implementing the steps of a custom logical function or process, and the scope of the preferred embodiments of the present application includes alternative implementations in which functions may not be performed in the order shown or discussed, including performing functions in a substantially simultaneous manner or in reverse order depending on the functions involved, which should be understood by technicians in the technical field to which the embodiments of the present application belong.

[0133] The logic and / or steps represented in the flowchart or otherwise described herein, for example, can be considered as an ordered list of executable instructions for implementing logical functions, and can be embodied in any computer-readable medium for use by an instruction execution system, device or apparatus (such as a computer-based system, a system including a processor, or other system that can fetch instructions from an instruction execution system, device or apparatus and execute instructions), or in combination with these instruction execution systems, devices or apparatuses. For the purpose of this specification, "computer-readable medium" can be any device that can contain, store, communicate, propagate or transmit a program for use by an instruction execution system, device or apparatus, or in combination with these instruction execution systems, devices or apparatuses. More specific examples of computer-readable media (a non-exhaustive list) include the following: an electrical connection with one or N wirings (electronic devices), a portable computer disk box (magnetic device), a random access memory (RAM), a read-only memory (ROM), an erasable and programmable read-only memory (EPROM or flash memory), a fiber optic device, and a portable compact disk read-only memory (CDROM). In addition, the computer-readable medium may even be paper or other suitable medium on which the program is printed, since the program may be obtained electronically by optically scanning the paper or other medium and then editing, interpreting or processing in other suitable ways as necessary and then storing it in a computer memory.

[0134] It should be understood that the various parts of the present application can be implemented by hardware, software, firmware or a combination thereof. In the above embodiment, the N steps or methods can be implemented by software or firmware stored in a memory and executed by a suitable instruction execution system. For example, if implemented by hardware, as in another embodiment, it can be implemented by any one or a combination of the following technologies known in the art: a discrete logic circuit having a logic gate circuit for implementing a logic function for a data signal, a dedicated integrated circuit having a suitable combination of logic gate circuits, a programmable gate array (PGA), a field programmable gate array (FPGA), etc.

[0135] A person skilled in the art may understand that all or part of the steps in the method for implementing the above-mentioned embodiment may be completed by instructing related hardware through a program, and the program may be stored in a computer-readable storage medium, which, when executed, includes one or a combination of the steps of the method embodiment.

[0136] In addition, each functional unit in each embodiment of the present application may be integrated into a processing module, or each unit may exist physically separately, or two or more units may be integrated into one module. The above-mentioned integrated module may be implemented in the form of hardware or in the form of a software functional module. If the integrated module is implemented in the form of a software functional module and sold or used as an independent product, it may also be stored in a computer-readable storage medium.

[0137] The storage medium mentioned above may be a read-only memory, a magnetic disk or an optical disk, etc. Although the embodiments of the present application have been shown and described above, it can be understood that the above embodiments are exemplary and cannot be understood as limiting the present application. A person of ordinary skill in the art may change, modify, replace and modify the above embodiments within the scope of the present application.

Claims

1. An online measurement method for unburned methanol and formaldehyde emissions from a methanol engine, characterized in that: The following steps are involved: When the methanol engine is running under the target test condition, obtaining the instantaneous volume concentration of unburned methanol and formaldehyde in the exhaust gas of the methanol engine; Calculating the emission mass of the unburned methanol and formaldehyde according to the instantaneous volume concentration and the target instantaneous u value of the unburned methanol and formaldehyde of the methanol engine; The instantaneous power of the methanol engine is used to determine the actual cycle work of the methanol engine, so as to determine the specific emission of the unburned methanol and formaldehyde according to the emission masses of the unburned methanol and formaldehyde and the actual cycle work.

2. The method according to claim 1, characterized in that Before collecting the instantaneous volume concentration of unburned methanol and formaldehyde in the exhaust gas of the methanol engine, the method further includes: Target exhaust sampling method for detecting unburned methanol and formaldehyde in methanol engines; The target test condition of the methanol engine is determined according to the target exhaust gas sampling method, and the u value of unburned methanol and formaldehyde of the methanol engine in the target test condition is calculated.

3. The method according to claim 1, characterized in that: The step of obtaining the instantaneous volume concentration of unburned methanol and formaldehyde in the exhaust gas of the methanol engine comprises: Using zero gas and span gas to perform response detection on the Fourier transform infrared spectroscopy gas analyzer, so that the Fourier transform infrared spectroscopy gas analyzer meets the preset calibration conditions; The instantaneous volume concentration of unburned methanol and formaldehyde in the exhaust gas of the methanol engine is measured using the Fourier transform infrared spectroscopic gas analyzer that meets the preset calibration conditions.

4. The method according to claim 1, characterized in that: The method of calculating the actual cycle work of the methanol engine by using the instantaneous power of the methanol engine comprises: Determining the instantaneous power of the methanol engine using the instantaneous speed and instantaneous torque of the methanol engine; The actual cycle work of the methanol engine is calculated based on the instantaneous power.

5. The method according to claim 1, characterized in that The formula for calculating the specific emission of unburned methanol and formaldehyde is: Among them, e gas is the specific emission of unburned methanol and formaldehyde; m gas is the emission mass of unburned methanol and formaldehyde; W act is the actual cycle work.

6. An online measurement device for unburned methanol and formaldehyde emissions from a methanol engine, characterized in that: include: An acquisition module, used for acquiring the instantaneous volume concentration of unburned methanol and formaldehyde in the exhaust gas of the methanol engine when the methanol engine is running under the target test condition; A calculation module, used for calculating the emission mass of the unburned methanol and formaldehyde according to the instantaneous volume concentration and the target instantaneous u value of the unburned methanol and formaldehyde of the methanol engine; A measuring module is used to determine the actual cycle work of the methanol engine using the instantaneous power of the methanol engine, so as to determine the specific emission of the unburned methanol and formaldehyde according to the emission mass of the unburned methanol and formaldehyde and the actual cycle work.

7. The device according to claim 6, characterized in that Also includes: A detection module, used for detecting a target exhaust gas sampling mode of unburned methanol and formaldehyde of a methanol engine before collecting the instantaneous volume concentration of unburned methanol and formaldehyde in the exhaust gas of the methanol engine; A determination module is used to determine the target test condition of the methanol engine according to the target exhaust gas sampling method before collecting the instantaneous volume concentration of unburned methanol and formaldehyde in the exhaust gas of the methanol engine, and calculate the u value of unburned methanol and formaldehyde of the methanol engine in the target test condition.

8. The device according to claim 6, characterized in that The acquisition module comprises: A detection unit, used for performing response detection on the Fourier transform infrared spectroscopic gas analyzer using zero gas and span gas, so that the Fourier transform infrared spectroscopic gas analyzer meets preset calibration conditions; The measuring unit is used to measure the instantaneous volume concentration of unburned methanol and formaldehyde in the exhaust gas of the methanol engine by using the Fourier transform infrared spectroscopic gas analyzer that meets the preset calibration conditions.

9. An electronic device, characterized in that: include: A memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the program to implement the online measurement method for unburned methanol and formaldehyde emissions of a methanol engine as described in any one of claims 1 to 5.

10. A computer-readable storage medium having a computer program stored thereon, characterized in that: The program is executed by a processor to implement the online measurement method for unburned methanol and formaldehyde emissions of a methanol engine as described in any one of claims 1-5.

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