CN117405567A - Brake particulate matter emission testing system and method - Google Patents
Brake particulate matter emission testing system and method Download PDFInfo
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- CN117405567A CN117405567A CN202311347849.1A CN202311347849A CN117405567A CN 117405567 A CN117405567 A CN 117405567A CN 202311347849 A CN202311347849 A CN 202311347849A CN 117405567 A CN117405567 A CN 117405567A
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N15/00—Investigating characteristics of particles; Investigating permeability, pore-volume or surface-area of porous materials
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N15/00—Investigating characteristics of particles; Investigating permeability, pore-volume or surface-area of porous materials
- G01N15/02—Investigating particle size or size distribution
- G01N15/0205—Investigating particle size or size distribution by optical means
- G01N15/0227—Investigating particle size or size distribution by optical means using imaging; using holography
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N15/00—Investigating characteristics of particles; Investigating permeability, pore-volume or surface-area of porous materials
- G01N15/06—Investigating concentration of particle suspensions
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N15/00—Investigating characteristics of particles; Investigating permeability, pore-volume or surface-area of porous materials
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Abstract
The invention discloses a brake particulate matter emission test system and a method, wherein the brake particulate matter emission test system comprises: the power system is used for providing power for the brake disc; the brake system is used for braking the brake disc; an air supply system for providing a temperature, humidity and wind speed environment for operation of the brake disc; the particle collection system is used for collecting particles; the particle analysis system is used for analyzing the collected particles; and the control system is used for controlling the working states of the power system, the brake system and the air supply system based on the standardized cyclic test conditions so as to obtain test data with repeatability and reproducibility. The invention can simulate the braking condition of the vehicle on the actual road, can provide a real test condition for the test of the braking abrasion particles, and can simulate the braking abrasion particle emission test of the vehicle at different environment temperatures to evaluate the particle stability of different braking systems.
Description
Technical Field
The invention belongs to the technical field of particulate matter testing, and particularly relates to a brake particulate matter emission testing system and method.
Background
Particulate Matter (PM) in air has long been recognized as an environmental and health hazard. Road transport is a major contributor to the environment PM, especially in urban areas. Particulate matter emitted by a motor vehicle may be classified into exhaust emission particulates and non-exhaust emission particulates according to the source from which it is generated. Exhaust emission particles are particles generated by incomplete combustion of fuel in the combustion process of an engine, while non-exhaust emission particles are generated by frictional wear of a motor vehicle in operation, such as frictional wear between a brake pad and a brake disc, clutch wear, frictional wear between a tire and the ground, and particles generated by wear are suspended in air again by external force after being deposited on a road surface.
With the increasing amount of automobile maintenance, brake particulate matter has become one of the important sources of particulate pollution in urban air. Brake wear can produce particles of various sizes, and studies have shown that fine particles therein are more harmful to human health. The components of the brake particles are complex and are related to the design of a brake system, the composition of brake materials, working conditions and the like. Currently, brake particulate emissions have not been incorporated into automotive emissions regulation limits management, but have attracted great attention from regulatory authorities in various countries.
Establishing a uniform brake particulate testing method has been challenging. The brake systems are various in types and different in test equipment. The braking condition is difficult to repeat, and the discharge amount of particles has large uncertainty. At present, two methods of a simulation power test and a real vehicle road test are mainly adopted for detecting brake particles. The simulated power test can control conditions on a test bed, but is difficult to fully simulate actual working conditions. The real vehicle road test is more representative, but is greatly affected by the test conditions. Therefore, there is an urgent need to develop a standardized set of brake particulate emissions testing systems.
Disclosure of Invention
The invention aims to provide a brake particulate matter emission testing system and method which are used for solving the problems in the prior art.
In order to achieve the above object, on the one hand, the present invention adopts the following technical scheme: a brake particulate emissions testing system, comprising:
the power system is used for providing power for the brake disc;
the brake system is used for braking the brake disc through the brake lining;
an air supply system for providing a temperature, humidity and wind speed environment for operation of the brake disc;
the particle collection system is used for collecting particles generated in the braking process of the brake disc;
the particle analysis system is used for analyzing the collected particles;
and the control system is used for controlling the working states of the power system, the brake system and the air supply system based on the standardized cyclic test conditions so as to obtain test data with repeatability and reproducibility.
As an alternative embodiment of the foregoing technical solution, the characteristic parameters of the standardized cyclic test condition include a representative rotation speed range of the brake disc, a braking strength and a braking frequency of the brake lining on the brake disc, and a temperature, a humidity and a wind speed environment of the brake disc.
As an optional implementation manner of the technical scheme, the brake disc further comprises a temperature acquisition system, wherein the temperature acquisition system is connected with the control system and is used for acquiring temperature data of different parts of the brake disc.
As an optional implementation manner of the above technical solution, the temperature acquisition system includes a plurality of temperature acquisition devices distributed at equal intervals along a radial direction of the brake disc, the temperature acquisition devices are connected with the control system, average temperature data acquired by the plurality of temperature acquisition devices is used as an input signal of the control system, and the control system maintains the average temperature of the brake disc within a representative temperature range by controlling the working state of the air supply system.
As an optional implementation manner of the technical scheme, the air supply system comprises an air inlet pipe and an air outlet pipe, a test bin for placing a brake disc is arranged between the air inlet pipe and the air outlet pipe, a variable frequency blower and an air filter are arranged on the air inlet pipe, and the variable frequency blower is connected with the control system.
As an optional implementation manner of the technical scheme, the air inlet pipe and the air outlet pipe are L-shaped, and the inner walls of the air inlet pipe and the air outlet pipe are provided with an antistatic coating and an anti-corrosion coating.
As an optional implementation manner of the above technical solution, the power system includes a driving device, a power output end of the driving device is connected with the brake disc, the driving device is connected with a control system, and the control system is used for controlling the engine to output different torques and rotational speeds so as to control the rotational speeds of different brake discs.
As an optional implementation manner of the above technical solution, the brake system includes a brake caliper and a hydraulic device, the control system is connected with the hydraulic device, the hydraulic device is connected with the brake caliper, and a brake lining is disposed on an inner side of the brake caliper.
As an optional implementation manner of the above technical scheme, the particulate matter collection system comprises a sampling probe, a sampling pipeline, a sampling flow stabilizing device and a sample receiving device which are sequentially arranged, wherein the sampling probe stretches into an output pipeline of the air supply system, and a conical inlet is formed in the front end of the sampling probe.
As an optional implementation manner of the above technical solution, the particulate matter analysis system includes a particulate matter mass analysis device, a particulate matter concentration analysis device, and a particulate matter particle size component analysis device, where the particulate matter mass analysis device is used for analyzing the collected particulate matter mass, the particulate matter concentration analysis device is used for analyzing the collected particulate matter concentration, and the particulate matter particle size component analysis device is used for analyzing the collected particulate matter particle size and component.
As an optional implementation manner of the above technical solution, the particulate matter particle size component analysis device includes a digital image scanning module, a particulate matter statistical analysis module, and an evaluation module, where the digital image scanning module is used to obtain a digital image of the particulate matter, the particulate matter statistical analysis module is used to count the particle size, the number and the components of the particulate matter, and the evaluation module is used to obtain the particle diameter distribution and the number variation rules under different standardized cyclic test conditions based on the particle size, the number and the components of the particulate matter, so as to evaluate the stability of the particulate matters of different braking systems and formulate the running-in optimization scheme of the braking system.
As an optional implementation manner of the above technical solution, the system further includes a calibration and data quality control system, the calibration and data quality control system is used for performing multi-point calibration on the particulate matter quality analysis device through a standard weight, performing multi-concentration calibration on the particulate matter concentration analysis device through a nano metal particle standard, performing size calibration on the particulate matter particle size component analysis device through a product specification grade (PSL) or a metal particle standard, and performing calibration on the control system through generating particulate matters by a smoke generator.
As an optional implementation manner of the above technical solution, the method further includes a data validity analysis system, where the data validity analysis system is configured to use a test result of the standard reference as a reference for measuring deviation, and evaluate validity of the test data.
On the other hand, the invention adopts the following technical scheme: a brake particulate matter emission test method comprises the following steps:
step A, controlling the working temperature, humidity and wind speed environment of a brake disc based on standardized cycle test conditions, and simulating the actual working condition of the brake disc;
step B, braking the brake disc through a brake lining;
step C, collecting particles generated in the braking process of a brake disc;
and D, analyzing the collected particles to obtain a test result with repeatability and reproducibility.
The beneficial effects of the invention are as follows:
the invention can simulate the braking condition of the vehicle on the actual road, can provide a real test condition for the test of the braking abrasion particles, and can simulate the braking abrasion particle emission test of the vehicle at different environment temperatures to evaluate the particle stability of different braking systems.
Drawings
Fig. 1 is a schematic structural view of an embodiment of the present invention.
In the figure: 1-a power system; 2-a brake system; 3-an air supply system; 4-a temperature acquisition system; 5-a particulate collection system; 6-a particulate matter analysis system.
Detailed Description
Examples
As shown in fig. 1, this embodiment provides a brake particulate matter emission test system, including:
a power system 1 for powering the brake disc;
a brake system 2 for braking the brake disc via a brake lining;
an air supply system 3 for providing a temperature, humidity and wind speed environment for the operation of the brake disc;
the particle collection system 5 is used for collecting particles generated in the braking process of the brake disc;
a particulate matter analysis system 6 for analyzing the collected particulate matter;
and the control system is used for controlling the working states of the power system, the brake system and the air supply system based on the standardized cyclic test conditions so as to obtain test data with repeatability and reproducibility. The standardized cyclic test conditions include a representative range of rotor speeds, brake strength and frequency of the brake pads to the rotor, and temperature, humidity and wind speed conditions of rotor operation.
The invention can simulate the braking condition of the vehicle on the actual road, can provide a real test condition for the test of the braking abrasion particles, and can simulate the braking abrasion particle emission test of the vehicle at different environment temperatures to evaluate the particle stability of different braking systems. When the vehicle is subjected to the abrasion particulate matter emission test of the brake system, the air supply system is arranged to provide the environment for the vehicle under the simulation of the change conditions of the external environment temperature, humidity and air speed, so that the accuracy of the particulate matter emission test is improved.
In this embodiment, the brake particulate matter emission test system further includes a temperature acquisition system 4, where the temperature acquisition system is connected to the control system, and the temperature acquisition system is used to acquire temperature data of different parts of the brake disc. The temperature acquisition system comprises a plurality of temperature acquisition devices which are distributed along the radial direction of the brake disc at equal intervals, and the temperature acquisition devices are connected with the control system. The temperature acquisition device adopts a thermocouple, average temperature data acquired by the temperature acquisition devices are used as input signals of the control system, and the control system maintains the average temperature of the brake disc in a representative temperature range by controlling the working state of the air supply system.
In some embodiments, the air supply system comprises an air inlet pipe and an air outlet pipe, a test bin for placing a brake disc is arranged between the air inlet pipe and the air outlet pipe, a variable frequency blower and an air filter are arranged on the air inlet pipe, and the variable frequency blower is connected with the control system. Wherein, the air inlet pipe and the air outlet pipe are L-shaped, and the inner walls of the air inlet pipe and the air outlet pipe are provided with an antistatic coating and an anti-corrosion coating.
The power system comprises a driving device, a power output end of the driving device is connected with the brake disc, the driving device is connected with a control system, and the control system is used for controlling the driving device to output different torques and rotating speeds of the engine so as to control the rotating speeds of different brake discs.
Specifically, the brake system comprises a brake caliper and a hydraulic device, the control system is connected with the hydraulic device, the hydraulic device is connected with the brake caliper, and a brake lining is arranged on the inner side of the brake caliper. The hydraulic device drives the brake caliper to move, so that the brake lining is contacted with the brake disc, and the brake of the brake disc is realized.
In some embodiments, the particulate matter collection system comprises a sampling probe, a sampling pipeline, a sampling flow stabilizing device and a sample receiving device which are sequentially arranged, wherein the sampling probe stretches into an output pipeline of the air supply system, and a conical inlet is formed in the front end of the sampling probe.
The particle analysis system comprises a particle mass analysis device, a particle concentration analysis device and a particle size component analysis device, wherein the particle mass analysis device is used for analyzing the collected particle mass, the particle concentration analysis device is used for analyzing the collected particle concentration, and the particle size component analysis device is used for analyzing the collected particle size and components.
The particle size component analysis device of the particles comprises a digital image scanning module, a particle statistics analysis module and an evaluation module, wherein the digital image scanning module is used for obtaining digital images of the particles, the particle statistics analysis module is used for counting the particle size, the particle number and the particle components of the particles, and the evaluation module is used for obtaining particle diameter distribution and a number variation rule under different standardized circulation test conditions based on the particle size, the particle number and the particle components of the particles, so that the particle stability of different braking systems is evaluated and a running-in optimization scheme of the braking systems is formulated.
In some embodiments, the brake particulate emissions testing system further comprises a calibration and data quality control system for multi-point calibration of the particulate mass analysis device by standard weights, multi-concentration calibration of the particulate concentration analysis device by nano-metal particle standards, size calibration of the particulate particle size component analysis device by PSL or metal particle standards, and calibration of the control system by generating particulate by the smoke generator.
In some embodiments, the brake particulate emissions testing system further comprises a data validity analysis system for evaluating validity of the test data using the test results of the standard reference as a reference for measurement bias.
The embodiment also provides a brake particulate matter emission testing method which is applied to the brake particulate matter emission testing system, and the method comprises the following steps:
step A, controlling the working temperature, humidity and wind speed environment of a brake disc based on standardized cycle test conditions, and simulating the actual working condition of the brake disc;
step B, braking the brake disc through a brake lining;
step C, collecting particles generated in the braking process of a brake disc;
and D, analyzing the collected particles to obtain a test result with repeatability and reproducibility.
According to the invention, the brake system is arranged on the brake sliding test bed, the brake system is tested by using standardized cyclic test conditions representing real driving conditions, and characteristic parameters of the standardized cyclic test conditions comprise a representative brake disc rotating speed range, the brake strength and the brake frequency of a brake lining on a brake disc, and the working temperature, humidity and wind speed environment of the brake disc. A thermal management scheme is formulated to regulate convective cooling of the brake system to ensure that the temperature conditions of the brake rotor represent a true driving state. The particulate sampling system extracts samples from the dilution wind, and the particulate sampling system allows for representative collection of the ultra-fine particles. The particle analysis system uses the calibrated detecting instrument to analyze the quantity and the number concentration of particles in the sample, the detecting range of the detecting instrument covers the critical particle size, the particle stability of different braking systems can be evaluated, and the running-in procedure of the braking systems is optimized to reduce unstable particle emission at the initial stage of braking. The heat treatment method is used for distinguishing the volatile and stable components in the brake particles, and definite repeatability and reproducibility standards are formulated so as to ensure the comparability of test results.
The individual components of the invention are further described below.
1. Braking system
The brake system is arranged on an inertia brake test bed, a representative single-group clamp type front axle brake is adopted as a test brake system, and the specific parameters are as follows:
brake disc diameter: 340mm; number of brake disc grooves: a single disc; brake caliper type: single piston pliers; brake lining: the ceramic composite material has a thickness of 10mm. The brake disc is required to be pre-processed with 4 mounting holes with the diameter of 1mm and the depth of 2mm for mounting the embedded thermocouple, the implantation depth of the thermocouple is controlled to be 1mm, and the mounting positions cover different radial positions of the contact area of the brake disc and the brake lining.
2. Brake cycle conditions
WLTP brake cycle was selected as the brake cycle condition, the total cycle length was 20 minutes, including City, rural, motorway road conditions. The main parameters are as follows: time: 1200s; distance travelled: about 15 km; average vehicle speed: about 45km/h; maximum vehicle speed: 140km/h; number of braking times: about 180 times; average braking deceleration: about 0.5g.
And before the test is started, the brake disc is preheated to 100 ℃ by low-speed driving, and the actual working state is simulated.
3. Temperature acquisition system
A K-type thermocouple with the diameter of 1mm is inserted into a mounting hole on the surface of a brake disc, the diameter of the mounting hole is 1.5mm, the depth of the mounting hole is 2mm,4 thermocouples are distributed at equal intervals and are respectively positioned at the inner edge, the middle part of the contact area of the brake disc, the middle part of the contact area is eccentric, the outer part of the contact area is eccentric, and the outer part of the contact area is positioned at the outer edge.
The control system reads the real-time temperature of the thermocouple as an input signal, optimizes the rotating speed of the blower through a PID control algorithm, realizes closed-loop heat management, and ensures that the temperature of the brake disc is in a preset range (100-150 ℃).
The temperature difference between the brake disc and the brake caliper is monitored simultaneously as an additional feedback input for thermal management. The convective cooling efficiency is varied by adjusting the dilution air volume to maintain the brake rotor in a representative temperature range. Typical average temperature of the brake disc is controlled between 100 ℃ and 150 ℃ and short-time peak temperature<200 ℃ and the wind speed range is 400-1500m 3 /h。
4. Air supply system
Adopts the blower to intake air, and the maximum air quantity is 1500m 3 The adjustable range of wind pressure is 500-2000Pa, the frequency converter controls the rotating speed of the fan, the control precision is +/-50 rpm, the air inlet is provided with a high-efficiency air filter, the filtering efficiency is up to 99.995% @0.3um, the filter is not smaller than the size of the fan interface, and the filtering area is not smaller than 0.5m 2 A wind shield is added between the filter and the blower, so that the filter is prevented from being influenced by back blowing of the blower; the air outlet is connected with an air pipe for a brake system, and the section size is 150x200mm; and the local dilution air tunnel is realized by matching with a diffusion type or conical air inlet of the sampling probe, and the dilution ratio is 10:1-20:1, a step of; the inner walls of the air inlet pipe and the air outlet pipe are respectively provided with an antistatic coating and an anti-corrosion coating.
5. Particulate matter collection system
A dilution air tunnel is established around the braking system, prefilter clean air is used as an air source, and the flow range is 400-1500m 3 And/h. The air inlet pipe and the air outlet pipe are both provided with a horizontal section and a 90-degree elbow, so that the full mixing can be realized.
The sampling probe is located the straight pipe section of low reaches of tuber pipe, guarantees the sample representativeness, and sampling system contains two sets of circuits: PM mass sampling and particle count sampling. Sample flow of PM mass samples: 10L/min, containing 10um and 2.5um centrifugal cracker and filter membrane (47 mm quartz microfiber filter membrane). Sample flow of particle count samples: 10L/min, comprising a thermal dilution system (350 ℃) and a particle counter (measuring range: 10-1000 nm).
The sampling pipeline is vertically arranged to avoid refraction, and is made of conductive electrostatic protection materials.
PM mass sampling adopts a balance to measure the weight increment number concentration of a filter membrane, particle number sampling adopts an auxiliary dilution system to be matched with a thermal dilution system and a particle counter which meet PN regulation requirements, particle size distribution adopts SMPS and/or EEPS to scan the particle size range of 5nm-10um, and component analysis adopts Raman spectrum and other technologies to analyze main components.
All the devices are calibrated regularly to ensure accuracy, and a perfect quality control and data quality evaluation system is established.
1) Sampling probe
Probe material: stainless steel or titanium alloy probes; diameter:10mm; probe length: 300mm; the front end of the probe is provided with a conical inlet, the rear end of the probe for avoiding particle sedimentation and inertial sedimentation is connected with a sampling pipeline, and a pipeline Di is arranged on the probe: 8mm.
2) Sampling pipeline
The pipeline material is as follows: stainless steel 304; pipeline internal diameter: 8mm; total length of pipeline: <2 meters. The right-angle pipe joint is adopted, so that the refraction pipeline is prevented from being grounded and the static electricity preventing effect is avoided.
3) Sampling flow stabilizing device
Flow regulator and flow controller: needle valve flow controller: mass flow controller control accuracy: <1%.
4) Sample receiving device
10um and 2.5um centrifugal pyrolyzers; diameter of filter paper: 47mm; filter paper material: quartz microfiber filter paper.
6. Particulate matter analysis system
1) Mass analysis
Sampling system: PM10 and PM2.5 sampling heads conforming to EN12341 standard respectively have flow rates of 16.7L/min and 10L/min, and the filtering membrane is 47mm quartz microfiber filter paper.
Dilution system: a two stage dilution box, model XXXX, was used in conjunction with HEPA filtered clean air. The dilution ratio is adjustable, typically set to 15:1. and monitoring the temperature and the humidity of the sample in real time after dilution.
And (3) a balance: an Mettler Toledo XP microbalance was used with an accuracy of 0.001mg. The balance is placed in a temperature-controllable weighing chamber.
Stabilization and correction: after the filter paper is loaded, the filter paper is balanced for 24 hours in a constant temperature and humidity box, and the temperature and the humidity are adjusted to be the same as those of the weighing chamber. The basis weight of the blank filter paper weight was corrected.
Mass concentration calculation: each test condition was repeated 3 times, and the mass concentration was calculated from the sampling time and the sampling flow rate and converted into an emission factor (mg/km).
2) Digital concentration analysis
Sampling system: the same sampling head is used for quality sampling, so that extra loss is avoided. The sampling flow rate is 10L/min.
Dilution system: adopt and accord with the two-stage dilution system of automobile exhaust particulate matter regulation requirement, adopt qualified HEPA filtration air, dilution ratio is adjustable, typically 40:1.
and a heating module: an electrically heated evaporating tube with a mixer is used, the heating temperature being adjustable, typically 300 ℃.
CPC particle counter: model TSI 3790, butanol as working solution, and size lower limit of 23nm.
Calibration and inspection: the concentration response of CPC was periodically checked and calibrated using a nano-metal particle standard. And recording the PCRF.
Calculation and report: the measurement results are reported as the number of concentrations after dilution, and the average is taken by repeating 3 times the test.
3) Particle size and fraction analysis
Sampling system: meets the above requirements and ensures the representativeness.
Analytical instrument: a scanning type electrodisplacive SMPS, a dilution-free EEPS and/or an ATOFMS, etc.
Parameter reporting: numerical particle size distribution, median diameter in counts, surface composition, elemental composition, and the like.
7. Calibration and data quality control system
1) Device calibration
Mass balance: multipoint calibration was performed monthly using E2 standard weights.
CPC particle counter: multiple concentration calibrations were performed monthly using the nano-metal particle standard.
SMPS and EEPS: size calibration was performed monthly using PSL or metal particle standards.
And (3) a control system: the monthly use of the smoke generator to generate particulate matter calibrates the control system.
2) Calibration method
The blank value is measured before and after each batch of samples and is used as the background correction of the equipment. The sample time was consistent with the sample using HEPA filtered clean air.
8. Data validity analysis system
1-2 batches of samples are selected in a month to be inserted into SRM for testing; SRM is a certified brake dust standard reference, test allowable error ± 10%; the SRM test results serve as an important reference for measuring deviations.
And evaluating test results before and after blank correction of the sample as an evaluation index. And counting repeated test data of each test condition, and determining the precision. And comparing with the SRM test result to determine accuracy deviation.
Test condition control: all tests were performed using the same set of brake systems that were ground in; the test environment is controlled at 20+/-2 ℃ and 50+/-5% RH; all tests used the same standardized test cycle program; the instrument parameter configuration is consistent.
Repeating the test: each test condition was repeated 5 times for independent tests; the brake system is completely cooled between each test, and the temperature of a brake disc is less than 50 ℃; repeated tests were performed sequentially on the same workday.
And (3) data processing: calculating the arithmetic mean value of the parameters of each sample; calculating standard deviation and Relative Standard Deviation (RSD) of each parameter; judging the repeatability of each parameter by using a single-factor analysis of variance tool; statistical rules are formulated to determine acceptable repeatability, such as confidence intervals, F-test p-values, etc.
Compared with the prior art, the invention has the following advantages:
1. the brake particulate matter emission test system capable of simulating real driving conditions on the brake sliding test bed is developed, vehicle braking conditions of a vehicle on an actual road can be simulated, and real test working conditions can be provided for testing brake abrasion particulate matters.
2. And (3) establishing a standardized thermal management scheme, such as specifying the minimum wind speed requirement, so as to adjust the convection cooling of the brake system and ensure that the temperature condition of the brake system represents the real driving state.
3. Using standardized sampling and detection methods, the sampling system should take into account representative acquisitions of the ultra-micron particles and the detection instrument should cover the critical particle size range and be calibrated.
4. And (3) evaluating the particle stability of different braking systems, and optimizing the running-in procedure of the braking systems so as to reduce unstable particle emission in the initial stage of braking.
5. The heat treatment method is developed to distinguish between volatile and stable components in the brake particles, which is of great importance for understanding the mechanism of formation of the different components.
6. Detection and reporting of particle number concentrations are contemplated, particularly for stable nanoparticles. This requires standardized dilution systems, calibration and transmission efficiency compensation methods.
7. And (3) formulating clear repeatability and reproducibility standards to ensure the comparability of test results.
In conclusion, the brake particulate matter emission test system and method provided by the invention are reasonable in design scheme, can evaluate the particulate matter stability of different brake systems, have important significance in reducing the emission of brake particulate matters and protecting the environment, and are worthy of popularization and application.
In the description of the present invention, the terms "mounted," "connected," "secured," and the like are to be construed broadly and may be fixedly connected, detachably connected, or integrally formed; may be a mechanical or electrical connection; may be directly connected or indirectly connected through an intermediate medium, and may be in communication with the inside of two elements or in interaction with the two elements, the specific meaning of the terms being understood by those skilled in the art. Furthermore, the particular features, structures, etc. described in the examples are included in at least one embodiment and those of skill in the art may combine features of different embodiments without contradiction. The scope of the present invention is not limited to the above-described specific embodiments, and embodiments which can be suggested to those skilled in the art without inventive effort according to the basic technical concept of the present invention are all within the scope of the present invention.
Claims (10)
1. A brake particulate emissions testing system, comprising:
a power system (1) for powering the brake disc;
a brake system (2) for braking the brake disc via a brake lining;
an air supply system (3) for providing a temperature, humidity and wind speed environment for operation of the brake disc;
the particle collection system (5) is used for collecting particles generated in the braking process of the brake disc;
a particulate matter analysis system (6) for analyzing the collected particulate matter;
and the control system is used for controlling the working states of the power system (1), the brake system (2) and the air supply system (3) based on the standardized cyclic test conditions so as to obtain test data with repeatability and reproducibility.
2. The brake particulate matter emissions test system of claim 1, wherein the characteristic parameters of the standardized cyclic test conditions include a representative brake disc speed range, brake pad to brake disc brake strength and frequency, and brake disc operating temperature, humidity, and wind speed environment.
3. The brake particulate matter emission test system according to claim 1, further comprising a temperature acquisition system (4), wherein the temperature acquisition system (4) is connected with the control system, and the temperature acquisition system (4) is used for acquiring temperature data of different parts of the brake disc; the temperature acquisition system (4) comprises a plurality of temperature acquisition devices which are distributed along the radial direction of the brake disc at equal intervals, the temperature acquisition devices are connected with the control system, average temperature data acquired by the plurality of temperature acquisition devices are used as input signals of the control system, and the control system enables the average temperature of the brake disc to be maintained in a representative temperature range by controlling the working state of the air supply system (3).
4. The brake particulate matter emission test system according to claim 1, wherein the air supply system (3) comprises an air inlet pipe and an air outlet pipe, a test bin for placing a brake disc is arranged between the air inlet pipe and the air outlet pipe, a variable frequency blower and an air filter are arranged on the air inlet pipe, and the variable frequency blower is connected with the control system; the air inlet pipe and the air outlet pipe are L-shaped, and the inner walls of the air inlet pipe and the air outlet pipe are provided with an antistatic coating and an anti-corrosion coating.
5. The brake particulate matter emission test system according to claim 1, wherein the power system (1) comprises a driving device, a power output end of the driving device is connected with the brake disc, the driving device is connected with a control system, and the control system is used for controlling the driving device to output different torques and rotational speeds of the engine so as to control the rotational speeds of different brake discs; the brake system (2) comprises a brake caliper and a hydraulic device, the control system is connected with the hydraulic device, the hydraulic device is connected with the brake caliper, and a brake lining is arranged on the inner side of the brake caliper; the particulate matter collection system (5) comprises a sampling probe, a sampling pipeline, a sampling flow stabilizing device and a sample receiving device which are sequentially arranged, wherein the sampling probe stretches into an output pipeline of the air supply system (3), and a conical inlet is formed in the front end of the sampling probe.
6. The brake particulate matter emission testing system according to claim 1, wherein the particulate matter analysis system (6) includes a particulate matter mass analysis device for analyzing the collected particulate matter mass, a particulate matter concentration analysis device for analyzing the collected particulate matter concentration, and a particulate matter particle diameter component analysis device for analyzing the collected particulate matter particle diameter and component.
7. The brake particulate matter emission testing system of claim 6, wherein the particulate matter particle size component analysis device comprises a digital image scanning module for obtaining a digital image of the particulate matter, a particulate matter statistical analysis module for counting the particle size, the number and the component of the particulate matter, and an evaluation module for obtaining a distribution of particle diameters and a variation law of the number under different standardized cyclic test conditions based on the particle size, the number and the component of the particulate matter, so as to evaluate the stability of the particulate matter of different brake systems (2) and formulate a running-in optimization scheme of the brake systems (2).
8. The brake particulate matter emission testing system of claim 7, further comprising a calibration and data quality control system for multi-point calibration of the particulate matter mass analysis device with standard weights, multi-concentration calibration of the particulate matter concentration analysis device with nano-metal particle standards, size calibration of the particulate matter particle size component analysis device with product specification grade or metal particle standards, and calibration of the control system with the aerosol generator generating particulate matter.
9. The brake particulate matter emission testing system of claim 1, further comprising a data validity analysis system for evaluating validity of the test data using a test result of the standard reference as a reference for measurement deviation.
10. A method for testing emission of brake particulate matter, applied to the system for testing emission of brake particulate matter according to any one of claims 1 to 9, characterized in that the method for testing emission of brake particulate matter comprises the following steps:
step A, controlling the working temperature, humidity and wind speed environment of a brake disc based on standardized cycle test conditions, and simulating the actual working condition of the brake disc;
step B, braking the brake disc through a brake lining;
step C, collecting particles generated in the braking process of a brake disc;
and D, analyzing the collected particles to obtain a test result with repeatability and reproducibility.
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| CN202311347849.1A CN117405567A (en) | 2023-10-17 | 2023-10-17 | Brake particulate matter emission testing system and method |
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Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN117825223A (en) * | 2024-03-05 | 2024-04-05 | 中汽研汽车检验中心（天津）有限公司 | Brake abrasion particulate matter testing system and method based on chassis dynamometer |
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Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
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| CN117825223A (en) * | 2024-03-05 | 2024-04-05 | 中汽研汽车检验中心（天津）有限公司 | Brake abrasion particulate matter testing system and method based on chassis dynamometer |
| CN117825223B (en) * | 2024-03-05 | 2024-05-31 | 中汽研汽车检验中心（天津）有限公司 | Brake abrasion particulate matter testing system and method based on chassis dynamometer |
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