Device for measuring air volume of self-ventilated motor and method thereof

Abstract

The present application relates to the technical field of self-ventilation motor design test, in particular to self-ventilation motor air volume test, specifically to a device for measuring self-ventilation motor air volume and a method thereof. In order to solve the problem that the existing self-ventilation motor air volume test method hinders the ventilation of the self-ventilation motor, a new device for measuring self-ventilation motor air volume and a method thereof are provided, which comprises a blower, an inlet pipe of a flowmeter, a thermal flowmeter, an outlet pipe of the flowmeter, an air butterfly valve, an air inlet of a ventilation air chamber, the ventilation air chamber, an air outlet of the ventilation air chamber and a U-shaped liquid level meter outside the ventilation air chamber, arranged in sequence in sealed communication. One port of the U-shaped liquid level meter is in communication with the outside atmosphere of the ventilation air chamber, and the other port is in communication with the inside of the ventilation chamber. The measuring device and method of the present application can stabilize the air volume of the self-ventilation motor and compensate for the resistance of the air inlet at the same time, so as to achieve the purpose of accurate measurement.

Description

Technical Field

[0001] This invention relates to the field of self-ventilated motor design and testing technology, and particularly to the air volume testing of self-ventilated motors, specifically a device and method for measuring the air volume of a self-ventilated motor. Background Technology

[0002] Motors generate various losses during operation, which are the source of heat. Typically, self-ventilated motors have a coaxially connected fan inside; the motor's rotation drives the fan to produce ventilation. If the ventilation volume is too low, the self-ventilated motor will overheat, damaging its insulation and posing a safety hazard. Therefore, airflow testing is a crucial aspect of self-ventilated motor testing.

[0003] Currently, the air volume of self-ventilating motors is measured using a speedometer, but there is a problem of large fluctuations in air volume during measurement. To address this issue, the existing method for measuring air volume is to place the motor in a ventilation chamber for testing. However, this method obstructs the ventilation of the self-ventilating motor, leading to inaccurate measurement results. Summary of the Invention

[0004] In order to solve the problem that existing methods for testing the air volume of self-ventilated motors hinder ventilation, this invention provides a new device and method for measuring the air volume of self-ventilated motors.

[0005] The present invention is achieved by the following technical solution: a device for measuring the air volume of a self-ventilating motor, comprising a blower, a flow meter inlet pipe, a thermal flow meter, a flow meter outlet pipe, an air butterfly valve, a ventilation chamber inlet, a ventilation chamber, and a ventilation chamber outlet arranged in a sealed manner (as is known to those skilled in the art: here, the sealed connection refers to the blower, the flow meter inlet pipe, the thermal flow meter, the flow meter outlet pipe, the air butterfly valve, the ventilation chamber inlet, the ventilation chamber, and the ventilation chamber outlet being connected in sequence and sealed at the connection point) and a U-shaped level gauge externally placed in the ventilation chamber, one port of the U-shaped level gauge being connected to the outside atmosphere of the ventilation chamber and the other port being connected to the ventilation fan room.

[0006] Furthermore, when air enters the ventilation chamber from the flow meter outlet pipe through the air butterfly valve, the airflow will cause disturbance and impact on the air in the ventilation chamber. To avoid this disturbance and impact, a baffle plate with a height lower than the height of the ventilation chamber and dividing the ventilation chamber into a pressure stabilizing zone and a measuring zone in the length direction is provided. The other port of the U-shaped level gauge is connected to the measuring zone of the ventilation chamber.

[0007] Furthermore, to ensure that the vibration of the blower and the ventilation chamber is not transmitted to the thermal flow meter and affects the measurement accuracy, a first metal bellows is sealed between the outlet of the blower and the inlet pipe of the flow meter to reduce vibration, and a second metal bellows is sealed between the air butterfly valve and the inlet of the ventilation chamber to reduce vibration, thereby further improving the measurement accuracy of the measuring device.

[0008] The measurement method using this device includes the following steps: 1) Place the self-ventilating motor in the ventilation chamber with its air inlet inside and its air outlet outside, ensuring an absolute seal between the self-ventilating motor and the ventilation chamber outlet (to ensure an absolute seal throughout the ventilation duct); 2) Open the air butterfly valve, turn on the blower, and turn the self-ventilating motor to the set speed; 3) Gradually adjust the opening of the air butterfly valve, observe the liquid levels at both ends of the U-shaped level gauge until they are level, and read the reading of the thermal flow meter, which is the ventilation volume of the self-ventilating motor at the set speed; 4) Repeat step 3) by changing the set speed of the self-ventilating motor multiple times to obtain the ventilation volume of the self-ventilating motor at different speeds; 5) Organize the data measured in steps 3) and 4) to obtain the numerical relationship between the self-ventilating motor speed and the ventilation volume, thus completing the air volume measurement of the self-ventilating motor.

[0009] The beneficial effects of this invention are as follows: 1) This invention cleverly uses the coordinated control of an air butterfly valve and a U-shaped level gauge to ensure that the static pressure in the measurement area of ​​the ventilation chamber is consistent with the external atmosphere of the ventilation chamber, thereby ensuring that the air inlet of the self-ventilating motor is unobstructed; 2) The use of the U-shaped level gauge facilitates intuitive observation of the measurement results during adjustment and testing; 3) By installing a self-ventilating motor at one end of the ventilation chamber and a blower at the other end, and cooperating with the air butterfly valve, the ventilation chamber can be adjusted from negative pressure to positive pressure. This structure can be applied to other measurements; 4) The measuring device and method of this invention can stabilize the airflow fluctuation of the self-ventilating motor while compensating for the air inlet resistance, so as to achieve accurate measurement; 5) This invention has a simple structure, ingenious design, and strong practicality. Attached Figure Description

[0010] Figure 1 This is a schematic diagram of the overall structure of the present invention.

[0011] In the diagram: 1—blower, 2—first metal bellows, 3—flow meter inlet pipe, 4—thermal flow meter, 5—flow meter outlet pipe, 6—air butterfly valve, 7—second metal bellows, 8—ventilation chamber, 9—wind baffle, 10—inspection port, 11—self-ventilating motor, 12—inlet pipe support, 13—U-shaped level gauge. Detailed Implementation

[0012] like Figure 1 As shown, a device for measuring the air volume of a self-ventilating motor includes a blower 1, a flow meter inlet pipe 3, a thermal flow meter 4, a flow meter outlet pipe 5, an air butterfly valve 6, an air inlet of a ventilation chamber 8, a ventilation chamber 8, and an air outlet of a ventilation chamber 8 arranged in a sealed manner (as is known to those skilled in the art: here, sealed connection means that the blower 1, the flow meter inlet pipe 3, the thermal flow meter 4, the flow meter outlet pipe 5, the air butterfly valve 6, the air inlet of the ventilation chamber 8, the ventilation chamber 8, and the air outlet of the ventilation chamber 8 are arranged in a sealed manner). A U-shaped level gauge 13 is externally placed in the ventilation chamber 8. One port of the U-shaped level gauge 13 is connected to the outside atmosphere of the ventilation chamber 8, and the other port is connected to the ventilation fan room.

[0013] In practice, when air enters the ventilation chamber 8 from the flow meter outlet pipe through the air butterfly valve 6, the airflow will cause disturbance and impact on the air inside the ventilation chamber 8. To avoid this disturbance and impact, a baffle plate 9 is sealed and fixed on one side of the ventilation chamber 8 near the air inlet (as is known to those skilled in the art: sealing and fixing means welding and sealing the front and rear end faces and bottom face of the baffle plate 9 to the front and rear walls and bottom wall inside the ventilation chamber 8, ensuring that the air entering from the air inlet of the ventilation chamber 8 can only flow into the measuring area of ​​the ventilation chamber 8 from above the baffle plate 9). The baffle plate 9 is lower than the height of the ventilation chamber 8 and divides the ventilation chamber 8 into a pressure stabilizing area and a measuring area in the length direction. The other port of the U-shaped level gauge 13 is connected to the measuring area of ​​the ventilation chamber 8. The ventilation chamber 8 is a hollow cuboid with a length of 2.5m, a width of 2m, and a height of 2m. The baffle plate 9 is located at 1 / 3 of the length of the ventilation chamber 8 and has a height of 1.2m.

[0014] In practice, to ensure that the vibrations of the blower 1 and the ventilation chamber 8 are not transmitted to the thermal flow meter 4 and affect the measurement accuracy, a first metal bellows 2 is sealed between the outlet of the blower 1 and the inlet pipe 3 of the flow meter to reduce vibration, and a second metal bellows 7 is sealed between the air butterfly valve 6 and the inlet of the ventilation chamber 8 to reduce vibration, thereby further improving the measurement accuracy of the measuring device.

[0015] In practice, the ventilation chamber 8 is equipped with a 0.5*0.5m inspection port 10 and a matching inspection door to facilitate subsequent maintenance.

[0016] Both the flow meter inlet pipe 3 and the flow meter outlet pipe 5 are supported by the inlet pipe bracket 12. The inlet pipe bracket 12 is a height-adjustable bracket. In practice, for ease of installation and maintenance, the design height of the inlet pipe bracket is 0.5m. A thermocouple is installed at the outlet of the blower 1 to facilitate the measurement of the inlet air temperature and subsequent evaluation of the air volume data. The thermal flow meter 4 is an insertion type thermal flow meter for easy disassembly and installation.

[0017] The measurement method using this device includes the following steps: 1) Place the self-ventilating motor 11 inside the ventilation chamber 8, with the air inlet of the self-ventilating motor 11 inside the ventilation chamber 8 and the air outlet of the self-ventilating motor 11 outside the ventilation chamber 8, while ensuring an absolute seal between the self-ventilating motor 11 and the air outlet of the ventilation chamber (the purpose is to ensure an absolute seal of the entire ventilation duct); 2) Open the air butterfly valve 6, turn on the blower 1, and turn on the self-ventilating motor 11 to the set speed; 3) Gradually adjust the opening of the air butterfly valve 6, observe the liquid level at both ends of the U-shaped liquid level gauge 13 until the liquid levels at both ends of the U-shaped liquid level gauge 13 are level, and read the reading of the thermal flow meter 4, which is the ventilation volume of the self-ventilating motor 11 at the set speed; 4) Change the set speed of the self-ventilating motor 11 multiple times and repeat step 3) to obtain the ventilation volume of the self-ventilating motor 11 at different speeds; 5) Organize the data measured in steps 3) and 4) to finally obtain the numerical relationship between the speed of the self-ventilating motor 11 and the ventilation volume, thereby completing the air volume measurement of the self-ventilating motor 11.

Claims

1. A method for measuring the air volume of a self-ventilating motor, characterized in that, This method is implemented using a device for measuring the air volume of a self-ventilating motor. The device for measuring the air volume of the self-ventilating motor includes a blower (1), a flow meter inlet pipe (3), a thermal flow meter (4), a flow meter outlet pipe (5), an air butterfly valve (6), a ventilation chamber inlet, a ventilation chamber (8), a ventilation chamber outlet, and a U-shaped level gauge (13) placed outside the ventilation chamber (8). One port of the U-shaped level gauge (13) is connected to the atmosphere outside the ventilation chamber (8), and the other port is connected to the ventilation fan room. The method includes the following steps: 1) placing the self-ventilating motor (11) inside the ventilation chamber (8) with the inlet of the self-ventilating motor (11) inside the ventilation chamber (8) and the outlet of the self-ventilating motor (11) outside the ventilation chamber (8), while ensuring self-ventilation. 1) Ensure absolute sealing between the motor (11) and the air outlet of the ventilation chamber (8); 2) Open the air butterfly valve (6), turn on the blower (1), and turn on the self-ventilating motor (11) to the set speed; 3) Gradually adjust the opening of the air butterfly valve (6), observe the liquid level at both ends of the U-shaped liquid level gauge (13) until the liquid levels at both ends of the U-shaped liquid level gauge (13) are level, and read the reading of the thermal flow meter (4), which is the ventilation volume of the self-ventilating motor (11) at the set speed; 4) Change the set speed of the self-ventilating motor (11) multiple times and repeat step 3) to obtain the ventilation volume of the self-ventilating motor (11) at different speeds; 5) Organize the data measured in step 3) and step 4) to finally obtain the numerical relationship between the speed of the self-ventilating motor (11) and the ventilation volume, thereby completing the air volume measurement of the self-ventilating motor (11).

2. The method for measuring the air volume of a self-ventilating motor according to claim 1, characterized in that, Inside the ventilation chamber (8), a baffle plate (9) is sealed and fixed on one side near the air inlet of the ventilation chamber. Its height is lower than that of the ventilation chamber (8) and it divides the ventilation chamber (8) into a pressure stabilizing area and a measuring area in the length direction. The other port of the U-shaped level gauge (13) is connected to the measuring area of ​​the ventilation chamber (8).

3. The method for measuring the air volume of a self-ventilating motor according to claim 2, characterized in that, The ventilation chamber (8) is a hollow cuboid with a length of 2.5m, a width of 2m, and a height of 2m. The wind baffle (9) is located at 1 / 3 of the length of the ventilation chamber (8) and has a height of 1.2m.

4. The method for measuring the air volume of a self-ventilating motor according to claim 3, characterized in that, A first metal bellows pipe (2) is sealed between the air outlet of the blower (1) and the inlet pipe (3) of the flow meter, and a second metal bellows pipe (7) is sealed between the air butterfly valve (6) and the air inlet of the ventilation chamber (8).

5. The method for measuring the air volume of a self-ventilating motor according to claim 3, characterized in that, The ventilation chamber (8) is equipped with a 0.5×0.5m inspection port (10) and a matching inspection door.

6. The method for measuring the air volume of a self-ventilating motor according to claim 5, characterized in that, The flow meter inlet pipe (3) and the flow meter outlet pipe (5) are both supported by the air inlet pipe bracket (12).

7. A method for measuring the air volume of a self-ventilating motor according to claim 5, characterized in that, The air inlet duct support (12) is a height-adjustable support.

8. A method for measuring the air volume of a self-ventilating motor according to claim 5, characterized in that, A thermocouple is installed at the outlet of the blower (1).

9. A method for measuring the air volume of a self-ventilating motor according to claim 5, characterized in that, The thermal flow meter (4) is an insertion thermal flow meter (4).

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