1 Scope
This standard specifies the terms and definitions, symbols and interpretations, overall structure, technical requirements, measurement modules, test control and data acquisition modules, test data processing, validation and evaluation of wind tunnel for heat transfer, and marking, packaging, transport and storage of heat transfer wind tunnel test equipment for heat exchangers of internal combustion engines used in automobiles, tractors, construction machinery and small vessels.
This standard is applicable to test equipment for wind tunnel for heat transfer (hereinafter referred to as wind tunnel for heat transfer) for heat exchangers of internal combustion engines (including liquid-gas and gas-gas heat exchange) used in automobiles, tractors, construction machinery, and small vessels to conduct heat transfer performance tests. It may be used as reference for the wind tunnel test equipment for heat exchangers of other purposes.
2 Normative references
The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies.
GB/T 2624.3 Measurement of fluid flow by means of pressure differential devices inserted in circular cross-section conduits running full - Part 3: Nozzles and Venturi nozzles
GB 11122-2006 Diesel engine oils
JJF 1059.1-2012 Evaluation and expression of uncertainty in measurement
JJG 667-2010 Liquid positive displacement flowmeter
JJG 1038-2008 Goriolis mass flow meters
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
3.1
wind tunnel for heat transfer
equipment for measuring the heat transfer performance and resistance performance of liquid-gas and gas-gas heat exchange devices
3.2
frontal area
the area of the windward side of the core of a heat exchanger with air as the cooling medium
3.3
effectiveness
the ratio of the actual heat exchange capacity of the heat exchanger to the maximum possible heat exchange capacity under the same conditions
3.4
hot side
the channel through which water flows in the water radiator, the channel through which oil flows in the oil radiator, and the channel through which charge air flows in the air-to-air intercooler
3.5
cool side
the channel through which normal pressure air flows in water radiator, oil radiator, and air-to-air intercooler
3.6
conversion trans-heat
the trans-heat at set temperature difference (the difference between the designated inlet temperature of high-temperature medium and low-temperature medium) converted from the actual trans-heat under the test condition, and it is also called the standard trans-heat
3.7
pressure drop
the static pressure difference formed by the test medium before and after flowing through the heat exchanger under the test condition, and it is also called resistance or working resistance
3.8
standard air
the air under the condition with the temperature of 20℃ and the pressure of 101.3 kPa
3.9
accuracy
the ability of an instrument to indicate or record a measured truth value, expressed by the difference between the indicated value and the truth value
3.10
precision
under the same conditions and repeated measurements of the same physical quantity using the same method, the degree that the obtained indication values are close to the same
3.11
absolute pressure
the pressure measured with absolute vacuum as the measurement reference
3.12
mass flowrate
the mass of medium flowing through the specified section per unit time
3.13
volume flowrate
the volume of medium flowing through a specified section per unit time
3.14
velocity
under the test condition, the air velocity at a certain point on the frontal surface of the heat exchanger
3.15
average velocity
under the test condition, the weighted average air velocity on the frontal surface of the heat exchanger
3.16
correlation coefficient
a measure of the degree of linear correlation between two variables
3.17
specific gas constant
proportional constant in the gas equation of state
Foreword i
1 Scope
2 Normative references
3 Terms and definitions
4 Symbols and interpretations
5 Overall structure
5.1 General
5.2 Negative pressure type wind tunnel for heat transfer
5.3 The test section is in the inlet side air chamber
5.4 The test section is in the outlet side air chamber.
5.5 Closed circulating wind tunnel for heat transfer
6 Technical requirements
6.1 Main module of negative pressure type wind tunnel for heat transfer
6.2 Main module of air chamber type wind tunnel for heat transfer
6.3 Closed circulating type wind tunnel for heat transfer
6.4 Hot water module
6.5 Hot oil module
6.6 High temperature and high pressure air module
7 Measurement module
7.1 Test section temperature measurement
7.2 Resistance measurement of test pieces from test section
7.3 Flowrate measurement
8 Test control and data acquisition module
8.1 Measurement control precision
8.2 Test medium
8.3 Test procedure
8.4 Test items
9 Processing of test data
9.1 Calculation of heat exchange capacity
9.2 Calculation of the heat transfer coefficient
9.3 Calculation of the conversion trans-heat
9.4 Calculation of heat balance
10 Validation and evaluation of wind tunnel for heat transfer
10.1 General
10.2 Standard samples
10.3 Verification and evaluation rules
11 Marking, packaging, transport and storage
11.1 Marking
11.2 Packaging
11.3 Transport
11.4 Storage of standard samples
11.5 Others
