Some standard content:
LDC621.436.018-629.12
National Standard of the People's Republic of China
GB 7028--86
Test method of charge air coolers formarine diesel engines
Published on November 25, 1986
Approved by the State Bureau of Standards
Implementation on October 1, 1987
W.bzsoso.cOI device.
National Standard of the People's Republic of China
Test method of charge air coolers for marine diesel enginesUDC 621.436.018
GB 7028-86
This standard applies to air coolers for supercharged diesel engines (referred to as air coolers) and also applies to air coolers for supercharged diesel engines for other purposes. 1 General
1.1 The test method for air coolers includes performance test, pressure test and reliability test. 1.2 The purpose of the performance test is to determine the heat transfer coefficient h, air pressure loss ?k·4Pk, water/pressure loss APL of the air cooler. 1.3 The performance test of the cooling element of the new structure must be carried out on the test bench according to the provisions of this standard, and the error of the effective data balance of the test results shall not exceed! ± 5%.
1.4 The test piece of the performance test of the cooling element must comply with GB2497-81 "Heavy-duty air coolers for marine diesel engines", GB 2198-81 Technical requirements for light air coolers for marine diesel engines. The test specimen structure is manufactured according to the actual structural dimensions of the components, with a minimum dimension of 250m×250m and a depth (air flow) of no less than 100mm. 1.5 Each type of air cooler product should be subjected to a performance test. Small air coolers can be tested on the test bench, and the test method is in accordance with the provisions of 2.3.1. When large air coolers cannot be tested on the test bench, the cooling components are tested on the test bench and the machine is tested in accordance with the provisions of 2.3.2.
1.6 To check the strength of the air cooler components and the sealing of the overall structure , the fin tubes and end covers of each air cooler must be pressure tested in accordance with the provisions of Article 3.1. The products must be subjected to a vibration test in accordance with the provisions of Articles 3.2 and 3.3 before leaving the factory. 1.7 In order to assess the reliability of the air cooler water section and the connection, each connection method (including technical changes) must be subjected to a test piece vibration test in accordance with the provisions of Chapter 4 of this standard. 2 Performance test
2.1 Test
2.1.1 The air system consists of a low-wind source heat exchanger, a rectifier section (voltage stabilizing section), a test section (including trial and measurement sections), wind conditioning equipment, wind temperature conditioning equipment, etc. The contraction angle of the measuring section shall not exceed 30°, and the expansion angle shall not exceed 10°. +15°. The wind speed of the wind source must meet the requirements of 2.2.2. The velocity field coefficient of the windward surface of the specimen shall not be less than 0.9. There must be a good thermal insulation layer on the outside of the measurement section from the air heater to the specimen outlet. 2.1.2 The cooling water system consists of a water pump, a water storage tank, a water level measurement tank, a water volume regulating device, a water temperature regulating device, an exhaust device, etc. The water pump flow rate should meet the requirements of 2.2.3. 2.1.3 The measurement system consists of various instruments required to measure flow, temperature, and pressure. 2.1.4 Use a standard throttling device or a Pitot tube to measure the test gas flow rate, and use a U-tube manometer, a Y61-type first-stage precision inclined micromanometer-or a DJ M9 type compensated micromanometer. The throttling device must comply with GB2624-81 "Technical requirements for throttling devices for flow measurement".
2.1.5 Use a standard turbine flow transmitter and its matching secondary instrument to measure water flow, and the volumetric method can be used. When using the volumetric method, the installation position of the detector must make the water flow path the same during measurement and testing. The turbine flow transmitter must comply with the technical requirements of JB1627-75 "Turbine Flow Transmitter".
2.1.6 Use a mesh resistance thermometer or a thermocouple arranged on the grid to accurately measure the average temperature on the air inlet and outlet surfaces. Use a secondary instrument National Bureau of Standards 1986 -11- 25 Issued
1987-10-01 Implementation
W.GB7028-86
The temperature meter shall be selected with a precision of not less than 0.5 level Q, plastic temperature bridge, and a precision of not less than 0.1 level 1 electric differential meter. The temperature of the network resistance thermometer shall be strictly tested.
2.1.7 Use a standard glass thermometer with a graduation value of 0.1C or a historical precision to measure the humidity of the cooling water inlet and outlet. 2.1.8 Use the following method to determine the average flow force of air inlet and outlet: 1. The cross-sectional area of the cross-sectional area is measured in sections around the whole area (the diameter is 2mm). The measuring hole is vertical and convex, and it must be smooth without any ridges or thorns. 2.1.9 Use a type tube dynamometer with a scale of 1 mm to measure the reaction force at the inlet and outlet of the base respectively. 2.1.8 Use a type 4 dynamometer with a scale of mm to measure the pressure at the outlet of the cold water delivery section. || tt|| 2.0 The installation price of the mesh micro-lighting The distance between the test piece and the flange (inlet and outlet) should be equal to 20m. The water inlet and humidity test should be installed as close to the water inlet as possible. The active hole should be kept at a distance of 1000nm from the test piece (or water inlet). 2.1.11 Measure the atmospheric pressure with a thermometer that complies with BY213-84 "Technical Conditions for Dynamic Water Pressure Gauges". Use a 201 bulb thermometer to measure the ambient temperature.
2.2 Cooling test method
2.2.1 Take the water flow rate as the variable and the gas flow rate as the variable. The relationship line of the change of heat transfer coefficient and air velocity is obtained. The parameter is less than one in the range specified in 2.2.3. The variable H is less than six in the range specified in 2.2.2, and the relationship line of () is used. At the same time, the air inlet and outlet pressure and pressure of each test point are measured, and the air flow rate is obtained. The relationship line is:
2.2.2 The change of air flow rate is the standard flow rate specified in GB2497-81 and GB2498-81 50 yuan ~ 151% 2.2.3 In the flow rate 1.0 ~ 2.5 At least six test points shall be selected within the range of m/s, and the water inlet temperature shall be set at 80℃ for 11 minutes and the water inlet temperature shall be changed within the range of 80±2.5℃. The water inlet temperature of each test point shall not exceed +0.2℃.
2.2.5 According to the method in 2.2.1, the air flow rate shall be changed one by one, and the test shall be conducted after the parameters are stable. Test each test point 3 times and take the average value.
2.3 Product test method
2.3.1 2.3.1.1 The test equipment should meet the requirements of Article 2.1, and the test accuracy should meet the requirements of Article 1.3. 2.3.1.2 Take the design water volume as the fixed parameter, and change the actual weight of the porcelain speed (take at least six values, and the range of change must include the design downstream point): then measure the parameters. 2.3.1.3 The test data shall be processed in accordance with the provisions of Article 2.4 [assuming 1=() is nonlinear]. 2.3.2 Engine test 2.3.2.1 The test method is to carry out the test according to the method of negative dynamic characteristics of the oil engine, and the user shall sign the refrigeration unit manufacturer's number according to the rest situation. 2.4 Test performance test data processing 2. 4. 1 Calculate or calculate the heat transfer coefficient W/m*.K (keul/m?.++y.....
武: Q.…--heat released by air, w (kcal/h): Sk--test air heat release n:
" and the logarithm of water, C
2.4.2 Calculate the heat transfer coefficient h according to the following formula: 2
Wf
GB7028—86
W/mK (keal/m?,hc)
--volume of the test piece core, m3.
武中:-
2.4.3 The air-blocking side heat sink has a uniform humidity distribution along the height of the fin. The air side thermal resistance can be separated by the following formula: ak—air side heat release coefficient, W/m2·K (kcal/m2h·c) α—water side heat release coefficient, W/m2·K (kcal/m2h·C); chemical coefficient: thermal conductivity of water arm material, w/·K (ksal/m·hc): water side heat release coefficient, m. The calculation of water side heat release coefficient α can be carried out according to the actual method. 2.4.4 Calculate the required number Rek, Nusselt number Nuk and Euler number Fuk on the air side according to the following formulas: Rek_uklik
αk·Dk
Wk-g-AUk
air weight flow inversion at the minimum load surface of the air channel, Pa/s (kgt/m2·s); D—air channel standard size,
Mk\-viscosity coefficient, pas (kg/m2), g—square inversion, m/s2,
air thermal conductivity, W/m·K (keal/m·h·c), Ak
Yk=-air{ratio, Pa/u(kgf/m3)
APk--air positive force loss, Pa (kgl/m). The temperature of the flat tooth at the actual gas inlet and outlet is used as the qualitative temperature. 2.4.5 The standard equation for heat release and air pressure loss on the air side is used. Nuk-CiRek
fuk -. C,Re?
2.4.6 The test results shall be reported in the form of a test report, which shall include 2.4.6.1 Ten-digit numerical information (average of 3 records) and arithmetic tables (determined in the attached) 2.4.6.2 Performance test results (determined in accordance with the attached data). 3 Pressure test
【3）
3.1 Before the assembly of each air cooler, the base tube and end tube shall be subjected to pressure test to check their lightness and tightness. The test tube shall be subjected to 2 times the design pressure, and the test time shall be 155 and 30 minutes respectively, without deformation or leakage. 3.2 Before the air cooler leaves the factory, the water cavity shall be subjected to pressure test. The test pressure shall be 1.5 times the design pressure, and shall not be less than 39.2×101Pa (4kgf/cm2). During the test, the water cavity is slowly pressurized. After reaching the specified pressure, it is stabilized for 3 minutes. There should be no leakage at all joints. 3.3 The air cooler with an independent shell should also be subjected to an airtightness test of the air cavity. The test pressure is 4.9×10~9.8×101Pa (0.5~1.0kgf/cm2) for 30 minutes. There should be no leakage at all joints. 4 Reliability test of water pipe and tube sheet connectionwww.bzxz.net
4.! A test piece (with dimensions similar to those of the test piece for cooling element performance test) must be made before the application of a connection method (including process changes) between the water pipe and the tube sheet of the air cooler. The vibration test is carried out on the vibration test. The test content includes the exploratory test and the resistance test.
4.2 In order to determine whether the vibrated test piece has its own leakage in the entire test frequency, an exploratory test must be carried out. The test frequency and amplitude are: the amplitude is ±0.25mm from 4~33Hz, ±0.076mm from 34~50Hz, the frequency interval is 1Hz, and the dwell time is 15s
4.3 Vibration resistance test. If the deep test finds a resonant frequency, the vibration test shall be carried out at least 2h at the resonance frequency. If there is no resonance, the vibration resistance test shall be carried out at a frequency of 50Hz and an amplitude of +0.4mm, and the vibration time shall be at least 2h. 4.4 The test piece shall be permanently installed on the vibration test machine, and the windward side shall be rigidly connected to the vibration test machine with screws. 4.5 During the test, the water tank shall be filled with water with a water pressure of 49×101P (5kgf/cm2). 4.6 After the test, there should be a test report, which includes: the technical method of connecting the tube and the tube sheet, the test department (including the test personnel), the test period, the vibration frequency and amplitude of the test, the vibration time, the positive force of the water cavity, the test equipment, and the test results (whether the water cavity is leaking or the pressure is decreasing).
4.7 The first product can be equipped for reliability assessment during the diesel engine long-term test. W. Test piece model:
Air preheating area Sk:
Water-milk heat exchange area St:
Water wall thickness change
Test point
Air flow rate
(kgf/m2*s）
(kg:/h)
Air inlet temperature
Air temperature
Air heat release plate
(kcal/h)
Air channel maximum
Water channel area
Air channel setting
Water channel setting|| tt||Water pipe material t
Chemical facilitation coefficient
Heat transfer coefficient
(keai/an3.
Wh)
Minimum cross-sectional area of air channel K:
Water channel area
Air channel standard size
Water channel standard size
Water pipe material:
Chemical facilitation coefficient
Heat transfer coefficient
Win2-k
(keal:m\+h-
Transformed heat transfer coefficient
GB 7028—86
Appendix A
Main parameters of air cooler performance test
(Supplement)
Air heat coefficient
Wm\ +k
(hcal/ms.hc)/(keal/m2.hc)
Air pressure loss
Vu ·a Pk
(kgr°/mi)
Water flow
(kgf?h)
Water inlet overflow
Water flow rate
Test date:
Test personnel:
Water heat
(kral/:)
W. Flow rate:
Test period:
Test personnel:
Water ratio
Water heat absorption
(kral/h)
Water heat release coefficient
(krat,m*.-
Room:
Atmospheric humidity:
Relative humidity:
Water pressure
(E: m2)
then
gas side effort
Shelt
gas invasion micro
hot Ping Deshen coupons
Ww;-K
(hr ali insih -c)
(kal /3.hC)
，2/m
(kt) m)
CB 7028--86
Appendix B
Performance curves and similar equations
(Supplement)
(Cooling element model t
(kyfim
Depth gauge F:
tigf/mt,s)
Relationship between heat transfer coefficient, air condensation loss and air item velocity.
aPrPitkRf/rm
Yongtong reverse length
Relationship curve between water pressure loss and water flow reverse FukaGeR+ k
（Depth: ）
Phase combustion standard program
W.:
GB7028--86
Appendix C
Calculation method of water side heat release system a1
（Reference No. Part）
The similarity equation of heat release of water in the special-shaped trough for steady forced motion can be selected as follows: r0.021Rea8.P
ka·Prrr
Taking into account the definition of heat measurement
ReL2000
S ( w-te)
Ret0 00(C)
2000Re10 00
Si. (t I w+t:)
tf-specific humidity of water (arithmetic mean of water inlet and outlet temperatures), K()-core temperature of the water pipe (special requirement), K(℃); + Iw
Q---thermal field of k, W(keal/n):
Prt I, P'cr.w --
-overflow temperature of water, humidity inside the water pipe! The water quality parameters (Table) NuLRe, GrL--· are the water quality parameters, the required number, and the Gram number respectively: the material rate parameters are determined by the water quality parameters of each test point. The water pipe length in the table is (m), and D is the inner diameter of the water pipe (or the inner diameter of the water pipe) (m). Formula (2) 1li is calculated according to the adjustment number Re=1000. Table C1
2 xm:
Wt
is determined by the public Wu, public
point temperature tw, and water test efficiency coefficient.
Additional Notes:
GB702B--86
【Based on the formula (℃2), formula (℃3)】, the water requirement in the standard is calculated by approximation, and the total amount of water required is proposed by the Institute of Water Resources. This standard was drafted by the Institute of Water Resources. The main drafter is Zhang Shulin.
t
According to the public and public
point mouse degree tw, water test efficiency coefficient.
Additional explanation:
GB702B--86
【Based on formula (℃2), formula (℃3)】, approximate calculation is performed to obtain the total amount of water required for the standard, proposed by the Ministry of Industry and Information Technology. This standard was drafted by the Ministry of Industry and Information Technology. The main drafter is Zhang Shulin.
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