Axial flow high pressure centrifugal fan

Abstract

The present invention provides an axial-flow high-pressure centrifugal fan, comprising a variable-frequency motor with a rotor and a stator, and also comprising a casing guide plate and a centrifugal impeller fixed on the rotor. The casing guide plate, the centrifugal impeller and the variable-frequency motor are sequentially installed in a pressure-resistant casing according to air inlet and air outlet directions. An inlet connecting flange is also provided at the air inlet, and an outlet connecting flange is also provided at the air outlet. The casing guide plate is designed as a cylindrical ring with an inner side edge concave in an arc shape to form a guide edge. The casing guide plate is provided to help change the flow direction of the fluid after the air enters, so that the wind blows to the stator and the motor housing of the variable-frequency motor. The motor can be cooled without using a cooling system alone, so that the working environment is stable and the failure rate is reduced. The centrifugal impeller is used to replace the traditional fan blade impeller to provide stable fluid flow in a high-pressure environment, and the beveled guide line provided on the edge side guides the wind direction to flow in the direction of the stator and the motor housing.

Description

Technical Field

[0001] The invention relates to the field of gas fluid measurement and verification, and in particular to an axial flow high-pressure centrifugal fan. Background Art

[0002] In order to realize flow meter calibration under different temperature, pressure and medium conditions, a special high-pressure gas flow calibration device is required. Taking natural gas as an example, it is usually achieved by cutting off the natural gas long-distance pipeline and then adjusting the pressure, temperature and flow to achieve the calibration conditions. After the calibration, the gas is returned to the natural gas long-distance pipeline. However, in actual operation, due to the influence of high-pressure natural gas station safety, environment, production scheduling, etc., the cost of implementation is very high. The investment in conventional natural gas real-flow calibration stations exceeds 100 million yuan, and the operation is also difficult during the detection process. The use of high-pressure loop calibration device can effectively reduce costs while improving the efficiency of flow meter calibration.

[0003] In extreme pressure environments such as the high-pressure loop detection link, a circulating fan or compressor is required as a gas flow driving device in the pipeline. The traditional high-pressure centrifugal fan is a fan blade, and its working pressure is normal pressure or slightly positive pressure. It cannot operate under high internal gas pressure to provide stable fluid flow; and in the working process, because the stator is in a high-pressure environment and rotates at high pressure and high speed, the stator in the engine often has operating failures due to excessive temperature, affecting work efficiency; if a high-pressure gas compressor is used, which is mainly used for pressurization of long-distance pipelines or gas processing plants, the disadvantages are large size, high power, high cost, and independent cooling pipes are required to cool the ambient temperature of the fan. Summary of the invention

[0004] The purpose of the present invention is to solve the shortcomings of the prior art and to propose an axial flow high pressure centrifugal fan.

[0005] To achieve the above object, the present invention adopts the following technical solutions:

[0006] An axial-flow high-pressure centrifugal fan comprises a variable-frequency motor with a rotor and a stator, a casing guide plate, and a centrifugal impeller fixed on the rotor. The casing guide plate, the centrifugal impeller, and the variable-frequency motor are sequentially installed in a pressure-resistant casing according to the air inlet and air outlet directions. An inlet connecting flange is also provided at the air inlet of the pressure-resistant casing, and an outlet connecting flange is also provided at the air outlet of the pressure-resistant casing. The casing guide plate is designed as a cylindrical circular ring with an inner side concave arc to form a guide edge.

[0007] The shell guide plate is provided to change the flow direction of the fluid after the air enters, so that the wind blows to the stator and the motor housing of the variable frequency motor. The motor can be cooled without using a separate cooling system, thereby stabilizing the working environment and reducing the failure rate.

[0008] Furthermore, the centrifugal impeller includes a circular front cover with an air inlet circular hole, a circular rear cover with an outer diameter smaller than the outer diameter of the front cover, and blades arranged between the front cover and the rear cover. The blades surround the air inlet circular hole on the center side to form a circle, and are perpendicular to the front cover and the rear cover. The blades are evenly divergently arranged around the edge side and are flush with the edges of the front cover and the rear cover respectively. When the air flows in from the outer side of the centrifugal impeller edge, they bend in the opposite direction of the rotation direction of the centrifugal impeller to form an oblique guide line opening in the air outlet direction. Using a centrifugal impeller to replace a traditional fan impeller can significantly increase the wind pressure, and the oblique guide line arranged on the edge side guides the wind to flow toward the stator and the motor housing.

[0009] Furthermore, the bevel guide line and the guide edge are located in a vertical plane area, so that the bevel guide line and the guide edge can work together to increase the efficiency of fluid guidance.

[0010] Furthermore, it also includes a high-voltage penetration piece arranged above the pressure-resistant shell, wherein a wire is arranged inside the high-voltage penetration piece and introduced into the pressure-resistant shell to be connected with the variable frequency motor.

[0011] A junction box is arranged above the high voltage penetration piece.

[0012] Avoid connecting the junction box directly to the pressure-resistant casing, which may cause damage or failure due to the junction box's inability to adapt to the high-pressure environment inside the pressure-resistant casing.

[0013] Furthermore, the variable frequency motor has a motor housing placed in a pressure-resistant casing, and a plurality of fixing facilities are provided between the motor housing and the inner side of the pressure-resistant casing, so that the variable frequency fan can work stably in the pressure-resistant casing and reduce vibration.

[0014] Furthermore, a fan bracket is provided below the outer side of the pressure-resistant casing, and there are at least two fan brackets for fixing the entire device.

[0015] The inlet connecting flange is connected to the air inlet duct, and the outlet connecting flange is connected to the air outlet duct. The connecting flange has a relatively large connection stability strength.

[0016] Compared with the prior art, the beneficial effects of the present invention are as follows: a shell guide plate is provided to change the flow direction of the fluid after the air enters, so that the wind blows to the stator and the motor casing of the variable frequency motor, and the motor can be cooled without using a cooling system alone, thereby stabilizing the working environment and reducing the failure rate; a centrifugal impeller is used instead of a fan impeller and a beveled guide line is provided, which can provide stable fluid flow in a high-pressure environment and further guide the wind direction to blow to the stator and the motor casing of the variable frequency motor, thereby improving motor cooling efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is an exploded view of Example 1 of the present invention;

[0018] Figure 2 It is a three-dimensional solid diagram of embodiment 1 of the present invention;

[0019] Figure 3 This is a schematic diagram of a casing guide plate according to Embodiment 1 of the present invention;

[0020] Figure 4 Schematic diagram of the centrifugal blade of Example 1 of the present invention Figure 1 ;

[0021] Figure 5 Schematic diagram of the centrifugal blade of Example 1 of the present invention Figure 2 ;

[0022] Figure 6 The fluid flow circuit diagram of Example 1 of the present invention;

[0023] Figure 7 The junction box of embodiment 1 of the present invention is a partial diagram;

[0024] Explanation of reference numbers: 1. Frequency conversion motor, 11. Motor housing, 12. Fixing facilities, 13. Rotor, 14. Stator, 2. Centrifugal impeller, 21. Front cover, 22. Rear cover, 23. Blade, 24. Bevel guide line, 25. Air inlet hole, 3. Casing guide plate, 31. Guide edge, 4. Pressure-resistant casing, 41. Fan bracket, 51. Inlet connecting flange, 52. Outlet connecting flange, 6. High-pressure penetration, 7. Junction box, 8. Fluid flow line. DETAILED DESCRIPTION

[0025] In order to provide a further understanding of the purpose, structure, features, and functions of the present invention, the following detailed description is given in conjunction with the embodiments.

[0026] like Figure 1-Figure 3As shown, an axial-flow high-pressure centrifugal fan includes a variable-frequency motor 1 provided with a rotor 13 and a stator 14, and also includes a casing guide plate 3, a centrifugal impeller 2 fixed on the rotor 13, the casing guide plate 3, the centrifugal impeller 2, and the variable-frequency motor 1 are sequentially installed in a pressure-resistant casing 4 according to the air inlet and outlet directions, the pressure-resistant design of the pressure-resistant casing 4 can withstand high-pressure fluid working conditions, and the strength is greater than that of conventional materials; the air inlet of the pressure-resistant casing 4 is also provided with an inlet connecting flange 51, and the air outlet of the pressure-resistant casing 4 is also provided with an outlet connecting flange 52, the casing guide plate 3 is designed as a cylindrical circular ring with a concave arc on the inner side, forming a guide edge 31.

[0027] like Figure 4-Figure 5 As shown, the centrifugal impeller 2 includes a circular front cover 21 with an air inlet circular hole 25, a circular rear cover 22 with an outer diameter smaller than the outer diameter of the front cover 21, and blades 23 arranged between the front cover 21 and the rear cover 22. The blades 23 surround the air inlet circular hole 25 on the center side to form a circle, are evenly arranged around the edge side, and are flush with the edges of the front cover 21 and the rear cover 22 respectively, and are bent in the opposite direction of the rotation direction of the centrifugal impeller 2 when approaching the outer side of the edge of the centrifugal impeller 2 to inlet air, forming a beveled guide line 24 opening in the air outlet direction.

[0028] Generally, the outer diameter of the front cover 21 is 600 mm, and the diameter of the rear cover 22 is 500 mm.

[0029] The blades 23 are arranged with thin and narrow edges compared to the fan-shaped blades 23 and are perpendicular to the front cover 21 and the rear cover 22 .

[0030] The bevel guide line 24 and the guide edge 31 are located in a vertical plane area.

[0031] like Figure 6 As shown, when the variable frequency fan is powered on and starts working, the centrifugal impeller 2 rotates with the rotation of the rotor 13, and the stator 14 begins to gradually heat up as the working time becomes longer. The air flow enters from the air inlet circular hole 25, and as the blades 23 rotate, the fluid flow line 8 is changed by the bevel guide line 24 to flow toward the stator 14 and the motor housing 11. The fluid that hits the guide edge 31 is also guided to change the fluid flow line 8 and flow toward the stator 14 and the motor housing 11. The temperature of the stator 14 and the motor housing 11 decreases as the fluid passes through, and the fluid finally flows out from the outlet connecting flange 52.

[0032] like Figure 7 As shown, a high-voltage penetration piece 6 is also provided above the pressure-resistant shell 4 , and a wire is provided inside the high-voltage penetration piece 6 and is introduced into the pressure-resistant shell 4 to be connected with the variable-frequency motor 1 .

[0033] A junction box 7 is arranged above the high-voltage penetration piece 6, and the junction box 7 is connected to an external power supply.

[0034] The variable frequency motor 1 has a motor housing 11 placed in a pressure-resistant shell 4 , and a plurality of fixing facilities 12 , generally three fixing facilities 12 , are arranged between the motor housing 11 and the inner side of the pressure-resistant shell 4 . The fixing facilities 12 are generally rod-shaped fixing facilities 12 .

[0035] A fan bracket 41 is arranged at the lower outer side of the pressure-resistant shell 4. There are at least two, usually two, fan brackets 41. The fan bracket 41 is designed to withstand pressure and plays a role in supporting the gravity of the entire device.

[0036] The inlet connection flange 51 is connected to the air inlet duct, and the outlet connection flange 52 is connected to the air outlet duct. The inlet connection flange 51 and the outlet connection flange 52 are respectively intermediate connection structures connecting the air inlet duct and the air outlet duct.

[0037] The present invention has been described by the above-mentioned relevant embodiments, however, the above-mentioned embodiments are only examples for implementing the present invention. It must be pointed out that the disclosed embodiments do not limit the scope of the present invention. On the contrary, changes and modifications made without departing from the spirit and scope of the present invention are all within the scope of patent protection of the present invention.

Claims

1. An axial flow high pressure centrifugal fan, comprising a variable frequency motor with a rotor and a stator, characterized in that: The invention also includes a casing guide plate and a centrifugal impeller fixed on the rotor; the casing guide plate, the centrifugal impeller and the variable frequency motor are sequentially installed in the pressure-resistant casing according to the air inlet and outlet directions; the pressure-resistant casing air inlet is also provided with an inlet connecting flange, and the pressure-resistant casing air outlet is also provided with an outlet connecting flange; the casing guide plate is designed as a cylindrical circular ring with an inner side concave arc to form a guide edge; the centrifugal impeller includes a circular front cover with an air inlet hole, a circular rear cover with an outer diameter smaller than the outer diameter of the front cover, and blades arranged between the front cover and the rear cover; the blades form a circle around the air inlet hole on the center side, and are perpendicular to the front cover and the rear cover, and are evenly divergently arranged around the edge side, and are flush with the edges of the front cover and the rear cover respectively, and are bent in the opposite direction of the rotation direction of the centrifugal impeller when approaching the outer side of the centrifugal impeller edge to the air inlet, forming a beveled guide line opening in the air outlet direction, and the beveled guide line and the guide edge are in a vertical plane area.

2. The axial flow high pressure centrifugal fan according to claim 1, characterized in that: It also includes a high-voltage penetration piece arranged above the pressure-resistant shell, wherein a wire is arranged inside the high-voltage penetration piece and introduced into the pressure-resistant shell to be connected with the variable-frequency motor.

3. The axial flow high pressure centrifugal fan according to claim 2, characterized in that: A junction box is arranged outside the high voltage penetration piece.

4. The axial flow high pressure centrifugal fan according to claim 1, characterized in that: The variable frequency motor has a motor housing disposed in a pressure-resistant housing, and a plurality of fixing facilities are arranged between the motor housing and the inner side of the pressure-resistant housing.

5. The axial flow high pressure centrifugal fan according to claim 1, characterized in that: A fan bracket is arranged below the outer side of the pressure-resistant shell, and there are at least two fan brackets.

6. The axial flow high pressure centrifugal fan according to claim 1, characterized in that: The inlet connection flange is connected to the air inlet duct, and the outlet connection flange is connected to the air outlet duct.

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