Reduced scale test bench for testing wind friction consumption and temperature of flywheel vacuum-pumping system

Abstract

The invention relates to the technical field of generator energy storage, and discloses a reduced scale test bench for testing wind friction consumption and temperature of a flywheel vacuum-pumping system, which comprises a five-axis machine tool, a flywheel reduced scale system, a vacuum-pumping device, a temperature measuring device and a force measuring device, the force measuring device is connected with the machine tool spindle and the machine tool rotary table, the flywheel reduced scale system is connected with the force measuring device, and the vacuumizing device and the temperature measuring device are both arranged on the flywheel reduced scale system. Power input and system support are provided through the machine tool spindle, and the rotating speed of the flywheel is convenient to adjust; the input torque and the bearing stress can be directly read through the rotary dynamometer at the input end and the three-way dynamometer on the base, and the wind friction test experiment principle is simple; the temperature of the cavity of the flywheel is measured through the thermocouple, the infrared thermal imager and the short-wave infrared thermometer measure the temperature of the surface of the flywheel in the rotating process through the glass window on the surface of the flywheel stator, and the temperature measurement mode is comprehensive.

Description

Technical Field

[0001] The present invention relates to the technical field of generator energy storage, and particularly relates to a reduced-scale test bench for testing the wind friction loss and temperature of a flywheel vacuum pumping system. Background Art

[0002] A flywheel rotating at high speed will generate heat due to friction with air. If normal heat dissipation cannot be achieved, it will affect the normal operation of the energy storage system. Therefore, the cooling and heat dissipation solution for the flywheel is crucial. The flywheel system is evacuated by a vacuum pump to create a high vacuum or even a completely vacuum state inside the flywheel system, reducing the frictional loss between the flywheel rotor and air at the source, thereby lowering the system temperature. This method can significantly reduce the mechanical wear of the system, avoid oxidation corrosion caused by contact with air, improve the energy conversion efficiency, and reduce the maintenance cost of the flywheel system.

[0003] Therefore, it is of great significance to clarify the air friction loss on the flywheel surface and the flywheel surface temperature under different vacuum degrees for reasonably selecting the flywheel gap vacuum degree. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to clarify the air friction loss on the flywheel surface and the flywheel surface temperature under different vacuum degrees.

[0005] To solve the above technical problem, the technical solution of the present invention is to provide a reduced-scale test bench for testing the wind friction loss and temperature of a flywheel vacuum pumping system, including a five-axis machine tool, a flywheel reduced-scale system, a vacuum pumping device, a temperature measuring device, and a force measuring device. A machine tool spindle and a machine tool turntable are provided on the five-axis machine tool. The force measuring device is connected to the machine tool spindle and the machine tool turntable. The flywheel reduced-scale system is connected to the force measuring device. The vacuum pumping device and the temperature measuring device are both provided on the flywheel reduced-scale system.

[0006] Optionally, the force measuring device includes a rotational force measuring instrument and a three-axis force measuring instrument. The upper end of the rotational force measuring instrument is connected to the machine tool spindle, and a transfer shaft is connected to the lower end. A plum blossom type elastic coupling is provided at the lower end of the transfer shaft. An input shaft is connected to the plum blossom type elastic coupling. The upper end of the flywheel reduced-scale system is connected to the input shaft. The three-axis force measuring instrument is provided on the machine tool turntable and is connected to the lower end of the flywheel reduced-scale system.

[0007] Optionally, the flywheel reduced-scale system includes a stator housing and a flywheel. The flywheel is provided inside the stator housing. The stator housing includes a stator housing body, an upper housing plate, and a lower housing plate. The upper housing plate is connected to the upper end of the stator housing body, and the lower housing plate is connected to the lower end of the stator housing body. An upper cover is provided at the center of the upper housing plate. The input shaft extends into the stator housing from the upper cover and is connected to the flywheel. The flywheel is connected to the lower housing plate through an output shaft.

[0008] Optionally, an upper end plate O-ring seal is provided between the upper end plate of the housing and the stator housing body, a lower end plate O-ring seal is provided between the lower end plate of the housing and the stator housing body, a lip seal and a seal flange are provided between the upper end cover and the input shaft, an upper end cover O-ring seal is provided between the upper end cover and the upper end plate of the housing, and the seal flange is arranged above the lip seal.

[0009] Optionally, a first deep groove ball bearing is provided at one end of the input shaft located inside the stator housing, an upper bearing seat is provided outside the first deep groove ball bearing, and the upper bearing seat is connected to the upper end plate of the housing.

[0010] Optionally, the flywheel includes a flywheel upper surface, a flywheel body, and a flywheel lower surface. The flywheel upper surface is connected to the upper end of the flywheel body, the flywheel lower surface is connected to the upper end of the flywheel body, the input shaft is connected to the flywheel upper surface, the output shaft is connected to the flywheel lower surface, a second deep groove ball bearing is provided on the output shaft, and a lower bearing seat is provided outside the second deep groove ball bearing. The lower bearing seat is connected to the lower end plate of the housing.

[0011] Optionally, the lower end plate of the housing is connected to the three-axis force gauge, and a transfer plate is provided between the lower end plate of the housing and the three-axis force gauge. A transfer plate O-ring seal is provided between the lower end plate of the housing and the transfer plate.

[0012] Optionally, the temperature measuring device includes a thermocouple. A plurality of thermocouples are provided and are inserted into the cavity between the stator housing and the flywheel from the stator housing body. A glass window is provided on the side of the stator housing body.

[0013] Optionally, the vacuum pumping device includes a tower joint and a vacuum gauge. Both the tower joint and the vacuum gauge are provided on the stator housing body and are arranged at a 90° angle. The tower joint is connected to an external vacuum pump.

[0014] Optionally, it further includes a friction torque test bench. The friction torque test bench includes a test input shaft, a test seal flange cover, and a test base. The lower end of the test input shaft is connected to the test base, the upper end of the test input shaft can be connected to the main shaft of the motor through a rotational force gauge, the test seal flange cover is arranged above the test base, and the test seal flange cover and the test base can place a seal ring for testing.

[0015] In summary, the present invention has at least one of the following beneficial effects:

[0016] 1. The present invention provides a test bench that can be used to test the surface wind friction loss of a generator energy storage flywheel and evaluate different flywheel surface temperature measurement methods. The overall structure is vertical, and power input and system support are provided by the machine tool spindle, which is convenient for adjusting the flywheel speed.

[0017] 2. The present invention directly reads the input torque and the bearing force through the input end rotating dynamometer and the three-way dynamometer of the base. The wind wear test experiment has a simple principle and is easy to operate.

[0018] 3. The present invention measures the temperature of the flywheel cavity by installing a thermocouple on the side of the flywheel stator, and measures the temperature of the flywheel surface during rotation through a glass window on the surface of the flywheel stator by an infrared thermal imager and a short-wave infrared thermometer, thereby providing a comprehensive temperature measurement method. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 This is a schematic diagram of the overall structure of a scaled test bench for a flywheel vacuum pumping system of the present invention;

[0020] Figure 2 It is a cross-sectional view of the overall structure of the scaled test bench of the flywheel vacuum pumping system of the present invention;

[0021] Figure 3 It is a top view of the overall structure of the scaled test bench of the flywheel vacuum pumping system of the present invention;

[0022] Figure 4 This is a schematic diagram of the overall structure of the sealing ring friction torque test bench of the present invention;

[0023] In the figure: 1. Machine tool spindle; 2. Rotary dynamometer; 3. Adapter shaft; 4. Plum blossom elastic coupling; 5. Input shaft; 6. Sealing ring flange; 7. Upper end cover; 8. Upper end plate of housing; 9. Stator housing body; 10. Vacuum gauge; 11. Glass window; 12. Lower end plate of housing; 13. Thermocouple; 14. Adapter plate; 15. Three-way dynamometer; 16. O-ring of upper end plate; 17. Lip seal; 18 , upper end cover O-ring; 19, upper bearing seat; 20, first deep groove ball bearing; 21, upper surface of flywheel; 22, flywheel body; 23, lower surface of flywheel; 24, output shaft; 25, lower end plate O-ring; 26, second deep groove ball bearing; 27, lower bearing seat; 28, adapter plate O-ring; 29, pagoda joint; 30, test input shaft; 31, test seal flange cover; 32, test base. DETAILED DESCRIPTION

[0024] The following combination Figures 1-4 The present invention is described in further detail.

[0025] The invention discloses a flywheel vacuum system scale test bench, which is a vertical structure as a whole and can be used to test the air friction loss and flywheel surface temperature of the flywheel under different vacuum degrees. Figure 1, including a five-axis machine tool, a flywheel scaling system, a vacuum pumping device, a temperature measuring device and a force measuring device. The five-axis machine tool is provided with a machine tool spindle 1 and a machine tool turntable. The force measuring device is connected to the machine tool spindle 1 and the machine tool turntable. The flywheel scaling system is connected to the force measuring device. The vacuum pumping device and the temperature measuring device are both arranged on the flywheel scaling system. The flywheel scaling system is a flywheel system obtained by reducing the size of a real flywheel without changing its internal structure and the characteristics of the gap flow field.

[0026] In a further embodiment, referring to Figure 2 , the force measuring device includes a rotary force measuring instrument 2 and a three-direction force measuring instrument 15. The upper end of the rotary force measuring instrument 2 is connected to the machine tool spindle 1 through a BT40 tool holder, and the lower end is connected with a transfer shaft 3. A plum blossom type elastic coupling 4 is arranged at the lower end of the transfer shaft 3 for buffering and vibration absorption. An input shaft 5 is connected to the plum blossom type elastic coupling 4 to realize the power input of the flywheel. The upper end of the flywheel scaling system is connected to the input shaft 5. The three-direction force measuring instrument 15 is arranged on the machine tool turntable and connected to the lower end of the flywheel scaling system;

[0027] Specifically, the rotary force measuring instrument 2 can measure the overall input torque of the system and the three-direction forces received by the upper bearing 20, while the three-direction force measuring instrument 15 can measure the three-direction forces borne by the lower bearing 26. The measurement results are used for subsequent calculation of air friction loss.

[0028] In a further embodiment, the flywheel scaling system includes a stator housing and a flywheel. The flywheel is arranged inside the stator housing. The stator housing includes a stator housing body 9, an upper housing end plate 8 and a lower housing end plate 12. The upper housing end plate 8 is connected to the upper end of the stator housing body 9, and the lower housing end plate 12 is connected to the lower end of the stator housing body 9. An upper end cover 7 is arranged at the center of the upper housing end plate 8. The input shaft 5 extends into the stator housing from the upper end cover 7 and is connected to the flywheel by screws. The flywheel is connected to the lower housing end plate 12 through an output shaft 24;

[0029] An upper end plate O-ring seal 16 is arranged between the upper housing end plate 8 and the stator housing body 9. A lower end plate O-ring seal 25 is arranged between the lower housing end plate 12 and the stator housing body 9. A lip seal 17 and a seal flange 6 are arranged between the upper end cover 7 and the input shaft 5. An upper end cover O-ring seal 18 is arranged between the upper end cover 7 and the upper housing end plate 8. The seal flange 6 is arranged above the lip seal 17;

[0030] Since there is a certain lateral swing during the vertical rotation of the flywheel, a first deep groove ball bearing 20 is arranged at one end of the input shaft 5 located inside the stator housing to bear the lateral swing force. An upper bearing seat 19 is arranged outside the first deep groove ball bearing 20, and the upper bearing seat 19 is connected to the upper housing end plate 8.

[0031] In a further embodiment, to reduce the weight of the test bench, a hollow flywheel is selected for the flywheel simulation test bench. The flywheel includes a flywheel upper surface 21, a flywheel body 22, and a flywheel lower surface 23. The flywheel upper surface 21 is connected to the upper end of the flywheel body 22 by bolts, and the flywheel lower surface 23 is connected to the upper end of the flywheel body 22 by bolts. The input shaft 5 is connected to the flywheel upper surface 21, and the output shaft 24 is connected to the flywheel lower surface 23 by bolts. A second deep groove ball bearing 26 is provided on the output shaft 24 to bear the lateral swinging force and the axial force in the vertical direction. An upper bearing housing 27 is provided outside the second deep groove ball bearing 26, and the upper bearing housing 27 is connected to the lower end plate 12 of the housing;

[0032] The lower end plate 12 of the housing is connected to the three-axis force sensor 15, and a transfer plate 14 is provided between the lower end plate 12 of the housing and the three-axis force sensor 15. A transfer plate O-ring seal 28 is provided between the lower end plate 12 of the housing and the transfer plate 14.

[0033] In a further embodiment, referring to Figure 3 , the temperature measuring device includes a thermocouple 13. There are multiple (at least 3) thermocouples 13, and they are longitudinally distributed. They are all inserted from the stator housing body 9 into the cavity between the stator housing and the flywheel to measure the temperature in the cavity. A glass window 11 is provided on the side of the stator housing body 9. The infrared thermal imager and the short-wave infrared thermometer measure the surface temperature of the flywheel rotor through the glass window 11;

[0034] The vacuum pumping device includes a flare fitting 29 and a vacuum gauge 10. Both the flare fitting 29 and the vacuum gauge 10 are provided at the middle height of the stator housing body 9, and the two are arranged at 90°. The flare fitting 29 is connected to an external vacuum pump through a hose. The working absolute pressure range of the vacuum pump is 0.05 - 101 kPa, which is used to establish and maintain the required low-pressure environment. During the experiment, the vacuum degree of the system can be changed by controlling the size of the vacuum pump valve, and the flywheel speed can be changed by controlling the speed of the machine tool spindle 1. The absolute air pressure test range of the vacuum gauge 10 is 0 - 101 kPa, which is used to measure the pressure inside the experimental device to ensure accurate monitoring and adjustment of the pressure during the experiment.

[0035] In a further embodiment, referring to Figure 4 , it further includes a friction torque test bench. The friction torque test bench includes a test input shaft 30, a test seal flange cover 31, and a test base 32. The lower end of the test input shaft 30 is connected to the test base 32, and the upper end of the test input shaft 30 can be connected to the motor spindle 1 through a rotational force sensor 2. The test seal flange cover 31 is provided above the test base 32, and a seal ring for testing can be placed between the test seal flange cover 31 and the test base 32.

[0036] The overall power consumption of the test bench of the present invention includes: the frictional power consumption of the first deep groove ball bearing 20 and the second deep groove ball bearing 26 (P 上轴承 , P 下轴承 ), the frictional power consumption of the lip seal 17 and the input shaft 5 (P 密封圈 ), and the windage loss of the flywheel (P 飞轮 ). The total power consumption of the test bench can be obtained by testing with a rotational dynamometer 2, and the power consumption of the test bench has the following relationship:

[0037] P 输入 = P 下轴承 + P 飞轮 + P 密封圈 + P 上轴承

[0038] The input torque of the entire test bench can be directly read through the rotational dynamometer 2. Subtracting the sum of the frictional torques of the lower bearing 26, the lip seal 17, and the upper bearing 20 from the input torque gives the frictional torque of the flywheel. The windage loss of the flywheel can be calculated by multiplying the frictional torque by the rotational speed;

[0039] The air frictional loss on the surface of the flywheel under different vacuum degrees and different rotational speeds can be obtained through the readings of the rotational dynamometer 2 and the three - direction dynamometer 15. The temperature changes on the surface of the flywheel and in the gap flow field can be monitored in real time according to the temperature measuring device.

[0040] Specifically, the method for testing the windage loss of the scaled - down test bench of the present invention includes:

[0041] S1. Design a seal test bench to test the frictional torque of the seal;

[0042] Among them, the test input shaft 30 is connected to the machine tool spindle 1 through the rotational dynamometer 2. Controlling the rotational speed of the machine tool spindle 1 can change the rotational speed of the test input shaft 30. The lip seal 17 is placed in the test base 32 and fixed by the test seal flange cover 31. The frictional torque of the seal corresponding to different rotational speeds can be obtained through the reading of the rotational dynamometer 2;

[0043] S2. After performing a dynamic balance test on the flywheel, design and install the scaled - down test bench as required; open the vacuum pump valve and control the vacuum degree of the test bench according to the reading of the vacuum gauge 10; control the rotational speed of the flywheel by adjusting the rotational speed of the machine tool spindle 1. After running for 4 h to reach a steady state, record the data of the rotational dynamometer 2 and the three - direction dynamometer 15 respectively;

[0044] S3. Multiply the input torque measured by the rotational dynamometer 2 under different working conditions by the rotational speed to obtain the total power consumption of the test bench under the corresponding working conditions;

[0045] S4. The frictional torques of the first deep groove ball bearing 20 and the second deep groove ball bearing 26 can be obtained through the following calculation formula:

[0046] M = μFd / 2

[0047] Where: M - bearing frictional torque; μ - bearing friction factor, which can be obtained by referring to relevant design manuals and is 0.002; F - bearing load, the load of the first deep groove ball bearing 20 is obtained from the reading of the rotating dynamometer 2, and the load of the second deep groove ball bearing 26 can be obtained from the three - component dynamometer 15. d - bearing inner diameter;

[0048] S5. According to the wind friction loss calculation formula P 输入 = P 下轴承 + P 飞轮 + P 密封圈 + P 上轴承 , calculate the corresponding wind friction loss under different working conditions.

[0049] This test bench provides three ways to measure the temperature of the flywheel, namely, measuring the temperature of the thermocouple 13 on the stator housing body 9, measuring the temperature of the cavity between the flywheel stator housing body 9 and the flywheel body 22; using an infrared thermal imager and a short - wave infrared thermometer to measure the surface temperature of the rotating flywheel.

[0050] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit them. Although the present invention has been described in detail with reference to the preferred embodiments, those of ordinary skill in the art should understand that the technical solutions of the present invention can be modified or equivalently replaced without departing from the spirit and scope of the technical solutions of the present invention, and they should all be covered by the scope of the claims of the present invention.

Claims

1. A flywheel vacuum system scale test bench, characterized in that: The invention comprises a five-axis machine tool, a flywheel scaling system, a vacuum pumping device, a temperature measuring device and a force measuring device, wherein the five-axis machine tool is provided with a machine tool spindle (1) and a machine tool turntable, the force measuring device is connected to the machine tool spindle (1) and the machine tool turntable, the flywheel scaling system is connected to the force measuring device, and the vacuum pumping device and the temperature measuring device are both arranged on the flywheel scaling system.

2. The flywheel vacuum system scale test bench according to claim 1, characterized in that: The force measuring device comprises a rotary dynamometer (2) and a three-axis dynamometer (15); the upper end of the rotary dynamometer (2) is connected to the main shaft (1) of a machine tool, and the lower end is connected to a transfer shaft (3); the lower end of the transfer shaft (3) is provided with a plum blossom-shaped elastic coupling (4); the plum blossom-shaped elastic coupling (4) is connected to an input shaft (5); the upper end of the flywheel reduction system is connected to the input shaft (5); and the three-axis dynamometer (15) is arranged on a machine tool turntable and connected to the lower end of the flywheel reduction system.

3. The flywheel vacuum system scale test bench according to claim 2, characterized in that: The flywheel scaling system comprises a stator housing and a flywheel. The flywheel is arranged in the stator housing. The stator housing comprises a stator housing body (9), a housing upper end plate (8) and a housing lower end plate (12). The housing upper end plate (8) is connected to the upper end of the stator housing body (9), and the housing lower end plate (12) is connected to the lower end of the stator housing body (9). An upper end cover (7) is arranged at the center of the housing upper end plate (8). The input shaft (5) extends from the upper end cover (7) into the stator housing and is connected to the flywheel. The flywheel is connected to the housing lower end plate (12) via an output shaft (24).

4. The flywheel vacuum system scale test bench according to claim 3, characterized in that: An upper end plate O-type sealing ring (16) is provided between the upper end plate (8) of the housing and the stator housing body (9), a lower end plate O-type sealing ring (25) is provided between the lower end plate (12) of the housing and the stator housing body (9), a lip sealing ring (17) and a sealing ring flange (6) are provided between the upper end cover (7) and the input shaft (5), an upper end cover O-type sealing ring (18) is provided between the upper end cover (7) and the upper end plate (8) of the housing, and the sealing ring flange (6) is provided above the lip sealing ring (17).

5. The flywheel vacuum system scale test bench according to claim 3, characterized in that: A first deep groove ball bearing (20) is provided on one end of the input shaft (5) located inside the stator housing. An upper bearing seat (19) is provided outside the first deep groove ball bearing (20). The upper bearing seat (19) is connected to an upper end plate (8) of the housing.

6. The flywheel vacuum system scale test bench according to claim 3, characterized in that: The flywheel comprises a flywheel upper surface (21), a flywheel body (22) and a flywheel lower surface (23); the flywheel upper surface (21) is connected to the upper end of the flywheel body (22); the flywheel lower surface (23) is connected to the upper end of the flywheel body (22); the input shaft (5) is connected to the flywheel upper surface (21); the output shaft (24) is connected to the flywheel lower surface (23); a second deep groove ball bearing (26) is provided on the output shaft (24); a lower bearing seat (27) is provided outside the second deep groove ball bearing (26); and the lower bearing seat (27) is connected to the lower end plate (12) of the housing.

7. The flywheel vacuum system scale test bench according to claim 6, characterized in that: The lower end plate (12) of the housing is connected to the three-dimensional dynamometer (15), and an adapter plate (14) is provided between the lower end plate (12) of the housing and the three-dimensional dynamometer (15), and an adapter plate O-type sealing ring (28) is provided between the lower end plate (12) of the housing and the adapter plate (14).

8. The flywheel vacuum system scale test bench according to claim 3, characterized in that: The temperature measuring device comprises a thermocouple (13). A plurality of the thermocouples (13) are provided and are all inserted into the cavity between the stator housing and the flywheel through the stator housing body (9). A glass window (11) is provided on the side of the stator housing body (9).

9. The flywheel vacuum system scale test bench according to claim 3, characterized in that: The vacuum extraction device comprises a pagoda connector (29) and a vacuum gauge (10). The pagoda connector (29) and the vacuum gauge (10) are both arranged on the stator housing body (9) and are arranged at 90 degrees. The pagoda connector (29) is connected to an external vacuum pump.

10. The flywheel vacuum system scale test bench according to claim 1, characterized in that: The invention also comprises a friction torque test bench, wherein the friction torque test bench comprises a test input shaft (30), a test sealing ring flange cover (31) and a test base (32), wherein the lower end of the test input shaft (30) is connected to the test base (32), and the upper end of the test input shaft (30) can be connected to the motor main shaft (1) via a rotary dynamometer (2), and the test sealing ring flange cover (31) is arranged above the test base (32), and the test sealing ring flange cover (31) and the test base (32) can be used to place a sealing ring for testing.

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