Airflow testing system (specifically designed for range hoods)

1、 Main technical performance indicators:

1. Purpose: Mainly used for air volume testing of range hoods.

2. Design basis: GB_17713-2011 "Range hood" Appendix C related requirements;

3. Testing principle: Simulate the actual working state of the test specimen in the testing wind tunnel, change the diameter of the orifice plate at the air outlet, and then measure the static pressure value at each air outlet. Then, use standard formulas to calculate the corresponding flow coefficient and air volume parameters at this time.

4. Test model: Top out air range hood;

5. Prototype power supply: single-phase AC100-300V, 50Hz, capacity 1kW

6. Testing station: single station.

7. Wind measurement range: 5m ³ -30m ³/min;

8. Measurement range of static pressure inside the cylinder: 0~1300Pa ± 0.5% fsPa;

9. Measurement error of air volume ± 3%;

10. Air temperature and humidity: 0-60 ℃± 3% fs, (5-99)% R · H ± 5% fs

11. Dimensions (approximately): 3700W × 800D × 1200H. (Specific dimensions are subject to the actual product).

2、 Control and measure parameters

1. Test the air duct:

The test air duct includes connectors, cross rectifiers, diffusion tubes, pressure reducing tubes (regulators), movable brackets, etc. Among them, the cross rectifiers, diffusion tubes, and pressure reducing tubes (regulators) are strictly made in accordance with the national standard GB/T17713 "Range Hood" Appendix C Figure C1.

2. Test orifice plate:

The test orifice plates are strictly in accordance with Appendix C Table C1, with a total of 15 throttling orifice plates and one blind plate. (Customizable according to customer requirements)

3. Environmental and pressure sampling system:

The equipment is equipped with a complete set of environment and pressure sampling system, among which the pressure sampling system is equipped with a Yokogawa pressure sensor to ensure accurate and reliable sampling.

4. Electric lifting system:

The electric lifting system provides good operability for the installation and commissioning of range hoods, reducing the workload of testing and commissioning.

5. Upper computer processing system:

Automated testing, calculation, and data output are achieved through computers and their peripheral devices, with graphical display and printing of test results. The human-machine dialogue operation is simple, with high accuracy, saving time and effort.

Test items: P-Q characteristics (relationship between flow rate and static pressure), Q - η characteristics (relationship between flow rate and efficiency), current, power.

This testing system can measure the corresponding curves of static pressure and air volume, air volume and speed, current, power, efficiency, etc. According to the method in Appendix A, the instrument shall be tested at rated voltage and rated frequency, and operated in speed mode. The indicated values shall comply with the provisions of Table 1:

Table 1 Air Performance Limit Values

3、 Testing principle and layout

This scheme adopts a blowing test mode, which automatically opens the nozzle combination according to the set air volume, and controls the air volume by infinitely adjusting the frequency of the auxiliary fan through a frequency converter; The middle of the wind chamber is composed of a uniform flow orifice plate, a nozzle, a starting actuator, and a nozzle plate; The interface size of the fan chamber is 600mm × 600mm. This system automatically calculates the fan airflow by measuring the pressure difference before and after the nozzle. When this equipment is running, the performance test device for the fresh air fan is turned on. The air volume of the auxiliary fan is controlled by controlling the opening and closing combination of the air chamber nozzle and the current frequency of the variable frequency device. The static pressure at the corresponding air volume is measured by a high-precision micro pressure gauge to obtain the corresponding data of the air volume and air pressure of the tested fan.