This standard applies to the measurement of exhaust smoke from marine diesel engines. GB 5741-1985 Measurement method for exhaust smoke from marine diesel engines GB5741-1985 Standard download decompression password: www.bzxz.net

UDC 621. 436. 06 : 629. 12
National Standard of the People's Republic of China
GB 5741—85
Measurement method for exhaust gas smoke of marine diesel engine
Issued on December 26, 1985
Implemented on October 1, 1986
Approved by the State Bureau of Standards
National Standard of the People's Republic of China
Measurement method for ezhaust gas smoke of marime diesel engine
This standard applies to the measurement of exhaust smoke of marine diesel engines. fDefinition
UDC621.436.06
GB 5741—86
1.1 Exhaust
Exhaust refers to the white, blue and black particles suspended in the exhaust gas of diesel engines due to incomplete combustion. These particles can absorb, reflect and refract light. White smoke is condensed from water vapor or liquid fuel vapor, blue smoke is usually particles obtained from incomplete combustion of fuel or lubricating oil, and black smoke is mainly composed of carbon particles, and the particle size is usually less than 1μm. 1.2 Smoke density
Smoke density is a parameter that characterizes the concentration of particulate matter in diesel engine exhaust. 2 Measuring instrument
Use a smoke-type smoke meter. The smoke-type smoke meter is also called a filter paper smoke meter, which is suitable for measuring the blackest smoke. The smoke meter used must be inspected and qualified by a national agency.
Smoke density is expressed by the degree of blackness of the filter paper, which is expressed in 0 to 10 Bo Xu units and is recorded as Re. The Bo Xu unit of white filter paper is specified as 0, and the Bo Xu unit of all black filter paper is 10. For example, R: 40 means a smoke density of 4.0 Bo Xu units. 3 Measurement conditions
3.1 The smoke density measurement of marine diesel engines should be carried out after the conditions are stable. 3.2 Smoke suppressants should not be added to diesel fuel specifically for measuring smoke density. If additives with smoke suppressant effects have been added to the diesel fuel used in the diesel engine, this should be noted in the test report.
4 Measurement method
4.1 Installation of sampling probe
4.1.1 The sampling probe should be installed on the axis of the straight pipe section of the diesel engine exhaust connecting pipe and should be installed against the gas flow direction, as shown in the figure. Issued by the National Bureau of Standards on December 26, 1985, and implemented on October 1, 1986. GB5741-85. Exhaust data of diesel engines. Installation method of sampling probe. 1.2 The distance between the front end of the sampling probe and the exhaust manifold flange of the diesel engine should be no less than 6D, and the length of the straight pipe section behind it should be no less than 6D, where D is the inner diameter of the exhaust connecting pipe. If the actual installation position of the probe cannot meet the above requirements, it must be ensured that the difference between each smoke measurement under the same working condition is no more than 0.3 Bo units, and the actual installation position of the probe should be indicated. 4.1.3 The internal pressure at the installation of the sampling probe should not be greater than 1.471kPa (150mmHO), and no negative pressure should occur. When the internal pressure of the pipe is greater than the above specified value, the pressure value in the pipe should be indicated. The inner diameter of the sampling hose connected to the sampling probe shall not be less than 4 μm. The volume (dead volume) from the sampling probe to the effective working surface of the filter paper should be controlled within 10% of the air volume of the piston pump at each time. If the dead volume increases due to the extension of the sampling hose length, it is still necessary to ensure that the non-sampling flue gas in the dead volume does not exceed 10% of the maximum air volume of the first extraction. The leakage of the US. grapefruit pump
In a sampling process1, the ambient air allowed to enter the sampling system (from the probe inlet to the filter paper surface) should not exceed 2% of the maximum volume of the pump.
US, car filter paperbzxz.net
The whiteness of the filter paper is 85±2.5%, and the pore size is 4.5μm. Under the conditions of an ambient temperature of 20°C, relative humidity of 55%~65%, and a filter paper temperature of 2.0~4.0 kPa, the filter paper permeability is 3000 mL/cm2·min. The thickness of the filter paper should not be greater than 0.18 mm. ±.5 Measurement requirements
4.5.1 The smoke meter must be calibrated before use. a. Use white filter paper for zero point calibration. b. Use a standard burning sample for reading calibration.
4.5.2 The smoke meter should be measured three times continuously for each smoke measurement point, and the time interval between two adjacent measurements should not exceed 1 minute. The arithmetic mean of the three measurement values ​​is taken as the smoke measurement result. If the difference between the three measurement values ​​exceeds 0.3 μm, the measurement should be repeated. 4.$.3 During the smoke measurement process, it is necessary to prevent condensed water from flowing into the air pump, and to prevent carbon smoke and condensed water from adhering to the sampling head and the wall of the sampling hose. If necessary, it can be blown clean with compressed air. ...
Additional remarks:
This standard was proposed by China National Marine Engineering Corporation. GB 5761—85
This standard was drafted by Harbin Marine Engineering College and Shanghai Shaoxing Diesel Engine Research Institute. The drafter of this standard is Wei.
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