Improved high-performance fire pump

Abstract

The improved high-performance fire pump comprises a centrifugal impeller, a volute, a rotating shaft and a motor, the centrifugal impeller comprises a rear disc, a front disc and blades, and the inner side of the rear disc is provided with a first plane; the impeller is characterized in that the blade comprises a main blade part and a small blade part which are integrally formed, the main blade part is provided with a main blade front edge, the rear edge of the small blade part is repeated with the main blade front edge, and an included angle a is formed between the top edge of the small blade part and the first plane; the included angles a between at least more than 50% of the top edges in the plurality of small blade parts and the first plane are not equal, and the included angles a are equal to 1-15 degrees. Through the design of the small blade part, turbulent flow or backflow and secondary flow at the blade inlet in the impeller cavity can be reduced, the anti-cavitation performance of the fire pump can be improved, and therefore the hydraulic performance and efficiency of the fire pump can be improved.

Description

Technical Field

[0001] The invention relates to the technical field of fire pumps and water pumps, and in particular to an improved high-performance fire pump. Background Art

[0002] The existing fire pump includes a centrifugal impeller, a volute, a rotating shaft, and a motor. The centrifugal impeller is installed in the volute and is connected to the motor through the rotating shaft. The centrifugal impeller includes a rear disc, a front disc, blades, and a hub. A plurality of blades are evenly distributed along the circumference and connected between the rear disc and the front disc. The inlet end of the front disc has an inlet ring, and the inner circumference of the rear disc has a hub. However, the existing fire pump still has the problem that the turbulence or backflow at the inlet of the blades in the impeller cavity and the secondary flow have a great influence, the anti-cavitation performance of the fire pump is poor, and the hydraulic performance and efficiency need to be further improved. Summary of the invention

[0003] The purpose of the present invention is to overcome the deficiencies in the prior art and to provide an improved high-performance fire pump, which, through the design of a small blade portion, can reduce turbulence or backflow and secondary flow at the blade inlet in the impeller chamber, thereby improving the anti-cavitation performance of the fire pump and thus improving the hydraulic performance and efficiency of the fire pump.

[0004] In order to achieve the above object, the technical solution adopted by the present invention is: An improved high-performance fire pump comprises a centrifugal impeller, a volute, a rotating shaft and a motor. The centrifugal impeller is installed in the volute and is connected to the motor through the rotating shaft. The centrifugal impeller comprises a rear disc, a front disc, blades and a hub. A plurality of blades are evenly distributed in the circumferential direction and connected between the rear disc and the front disc. The inlet end of the front disc has an inlet ring, the inner circumference of the rear disc has a hub, and the inner side of the rear disc has a first plane. The invention is characterized in that the blade comprises a main blade portion and a small blade portion, the small blade portion and the main blade portion are integrally formed, the main blade portion has a main blade leading edge, the trailing edge of the small blade portion overlaps with the main blade leading edge, that is, the trailing edge of the small blade portion constitutes a part of the main blade leading edge, the top edge of the small blade portion has an angle a with the first plane, and the angle a between the top edges of at least 50% of the plurality of small blade portions and the first plane is unequal.

[0005] Furthermore, the included angles a between the top edges of at least 90% of the plurality of small blade portions and the first plane are different.

[0006] Furthermore, the angle a=1-15°.

[0007] Furthermore, the small blade portion has a first curved surface and a second curved surface that are relatively arranged, and the bending directions of the first curved surface and the second curved surface are consistent with or the same as the bending direction of the main blade portion; from the radial inside to the radial outside, the curvature of the first curved surface gradually decreases, and smoothly transitions with the leading edge of the main blade at the trailing edge of the small blade portion.

[0008] Furthermore, the curvature of the second arc-shaped surface gradually decreases from the radial inner side to the radial outer side, and smoothly transitions with the leading edge of the main blade at the trailing edge of the small blade portion.

[0009] Furthermore, the leading edge of the main blade has a radius R, the leading edge of the small blade of the small blade portion has a radius r, and the inner hole of the inlet ring also has a radius r, where r=(0.7-0.9)R.

[0010] Furthermore, the leading edge of the main blade has an axial width B, and the small blade portion has a maximum axial width b, where b=(0.01-0.3)B.

[0011] Furthermore, the axial width B=(0.25-0.55)R.

[0012] Furthermore, a first arc-shaped flow guide portion is arranged at the leading edge of the small blade of the small blade portion, and a second arc-shaped flow guide portion is arranged between the top edge of the small blade portion and the leading edge of the main blade.

[0013] The improved high-performance fire pump of the present invention can reduce turbulence or backflow and secondary flow at the blade inlet in the impeller cavity through the design of the small blade part, and can improve the anti-cavitation performance of the fire pump, thereby improving the hydraulic performance and efficiency of the fire pump. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 This is a schematic diagram of the main structure of the impeller of the improved high-performance fire pump of the present invention; Figure 2 It is a schematic diagram of the side view structure of the impeller of the improved high-performance fire pump of the present invention; Figure 3 It is a schematic diagram of a partially enlarged structure of an impeller of an improved high-performance fire pump of the present invention; Figure 4 It is a schematic diagram of the structure of the small blade part of the present invention.

[0015] In the figure: rear disc 1, front disc 2, blades 3, hub 4, arc-shaped transition portion 11, inlet ring 21, main blade portion 31, small blade portion 32, main blade leading edge 33, first arc-shaped surface 34, second arc-shaped surface 35. DETAILED DESCRIPTION

[0016] In order to make the technical solution and advantages of the present invention clearer, the technical solution of the present invention will be further described in detail in detail with reference to the accompanying drawings. It can be understood that the specific embodiments described here are only partial embodiments of the present invention, which are only used to explain the present invention, not to limit the present invention. It should be noted that, for the convenience of description, only the parts / structures related to the present invention are shown in the accompanying drawings, and other related parts can refer to the general design. In the absence of conflict, the embodiments of the present invention and the technical features in the embodiments can be combined with each other to obtain new embodiments.

[0017] Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention. In addition, unless otherwise defined, the technical terms or scientific terms used in the description of the present invention should be the common meanings understood by ordinary technicians in the field to which the present invention belongs.

[0018] The present invention will be further described in detail below in conjunction with the accompanying drawings.

[0019] like Figure 1-4 As shown, an improved high-performance fire pump includes a centrifugal impeller, a volute, a rotating shaft, and a motor. The centrifugal impeller is installed in the volute and is connected to the motor through the rotating shaft. The centrifugal impeller includes a rear disc 1, a front disc 2, blades 3, a hub 4, and an inlet ring 21. A plurality of blades 3 are evenly distributed along the circumferential direction and connected between the rear disc 1 and the front disc 2. The inlet end of the front disc 2 has an inlet ring 21, the inner circumferential side of the rear disc 1 has a hub 4, and the inner side of the rear disc 1 has a first plane ( Figure 3 is a vertical plane or a plumb plane); it is characterized in that: the blade 3 includes a main blade portion 31 and a small blade portion 32, the small blade portion 32 and the main blade portion 31 are integrally formed, the main blade portion 31 has a main blade leading edge 33, the trailing edge of the small blade portion 32 repeats or overlaps with the main blade leading edge 33, that is, the trailing edge of the small blade portion 32 constitutes a part of the main blade leading edge 33, and an angle a is formed between the top edge of the small blade portion 32 and the first plane, and the angle a between the top edges of at least 50% (≥0.5N) of the plurality of small blade portions 32 (N) and the first plane is not equal (a1≠a2≠a3≠a4...); preferably, the angle a between the top edges of at least 90% (≥0.9N) of the plurality of small blade portions 32 (N) and the first plane is not equal (a1≠a2≠a3≠a4...).

[0020] Further, the angle a=2-10°, preferably 4-8°.

[0021] An improved high-performance fire pump of the present invention can reduce turbulence or backflow and secondary flow at the blade inlet in the impeller chamber through the design of the small blade portion 32, specifically, the angle a between the top edge of at least 50-90% (≥0.5-0.9N) of the multiple small blade portions 32 (N) is different from the first plane, which can improve the anti-cavitation performance of the fire pump, thereby improving the hydraulic performance and efficiency of the fire pump.

[0022] The small blade portion 32 has a first curved surface 34 and a second curved surface 35 which are relatively arranged. The bending directions of the first curved surface 34 and the second curved surface 35 are consistent with or the same as the bending direction of the main blade portion 31. From the radial inside to the radial outside, the curvature of the first curved surface 34 gradually decreases, and smoothly transitions with the leading edge 33 of the main blade at the trailing edge of the small blade portion 32.

[0023] The curvature of the second arc surface 35 gradually decreases from the radial inner side to the radial outer side, and smoothly transitions with the main blade leading edge 33 at the trailing edge of the small blade portion 32 .

[0024] An improved high-performance fire pump of the present invention, through the design of the small blade portion 32, specifically, the curvature of the first arc surface 34 gradually decreases from the radial inside to the radial outside, and smoothly transitions with the main blade leading edge 33 at the trailing edge of the small blade portion 32; the curvature of the second arc surface 35 gradually decreases from the radial inside to the radial outside, and smoothly transitions with the main blade leading edge 33 at the trailing edge of the small blade portion 32, which can better reduce the turbulence or backflow and secondary flow at the blade inlet in the impeller chamber, and can further improve the anti-cavitation performance of the fire pump, thereby improving the hydraulic performance and efficiency of the fire pump.

[0025] like Figure 3 As shown, further, the main blade leading edge 33 has a radius R, the small blade leading edge of the small blade portion 32 has a radius r, and the inner hole of the inlet ring 21 also has a radius r, r=(0.7-0.9)R, preferably 0.8.

[0026] The main blade leading edge 33 has an axial width B, and the small blade portion 32 has a maximum axial width b, where b=(0.02-0.3)B, preferably, 0.13-0.18.

[0027] Axial width B=(0.3-0.5)R, preferably 0.4.

[0028] A first arc-shaped flow guide portion is provided at the leading edge of the small blade portion 32, and a second arc-shaped flow guide portion is provided between the top edge of the small blade portion 32 and the leading edge 33 of the main blade. Figure 3 shown.

[0029] The present invention optimizes the design of specific parameters or dimensions of the small blade portion 32, specifically r=(0.7-0.9)R, b=(0.02-0.3)B, B=(0.3-0.5)R, which can better reduce turbulence or backflow and secondary flow at the blade inlet in the impeller chamber, and can further improve the anti-cavitation performance of the fire pump, thereby improving the hydraulic performance and efficiency of the fire pump.

[0030] The improved high-performance fire pump of the present invention can reduce turbulence or backflow and secondary flow at the blade inlet in the impeller cavity through the design of the small blade part, and can improve the anti-cavitation performance of the fire pump, thereby improving the hydraulic performance and efficiency of the fire pump.

[0031] The above-mentioned implementation modes are for explanation of the present invention rather than limitation of the present invention. It can be understood that various changes, modifications, substitutions and variations can be made to these embodiments without departing from the principle and spirit of the present invention. The scope of protection of the present invention is defined by the attached claims and their equivalents.

Claims

1. An improved high-performance fire pump, comprising a centrifugal impeller, a volute, a rotating shaft, and a motor, wherein the centrifugal impeller is installed in the volute and is connected to the motor through the rotating shaft, the centrifugal impeller comprises a rear disc (1), a front disc (2), blades (3), and a hub (4), a plurality of blades are evenly distributed along the circumferential direction and connected between the rear disc and the front disc, the inlet end of the front disc has an inlet ring (21), the inner circumference side of the rear disc has a hub, and the inner side of the rear disc has a first plane; characterized in that: The blade (3) comprises a main blade portion (31) and a small blade portion (32), wherein the small blade portion and the main blade portion are integrally formed, the main blade portion has a main blade leading edge (33), the trailing edge of the small blade portion overlaps with the main blade leading edge, that is, the trailing edge of the small blade portion constitutes a part of the main blade leading edge, the top edge of the small blade portion has an included angle a with the first plane, and the included angle a between the top edges of at least 50% of the plurality of small blade portions and the first plane is unequal.

2. An improved high performance fire pump as claimed in claim 1, characterized in that: The included angles a between the top edges of at least 90% of the plurality of small blade portions and the first plane are different.

3. An improved high performance fire pump as claimed in claim 2, characterized in that: The angle a=1-15°.

4. An improved high performance fire pump as claimed in claim 1, characterized in that: The small blade portion (32) has a first curved surface (34) and a second curved surface (35) which are arranged opposite to each other, and the curvature direction of the first curved surface and the second curved surface is consistent with the curvature direction of the main blade portion (31); the curvature of the first curved surface gradually decreases from the radial inner side to the radial outer side, and smoothly transitions to the main blade leading edge (33) at the trailing edge of the small blade portion.

5. An improved high performance fire pump as claimed in claim 4, characterized in that: The curvature of the second arc surface (35) gradually decreases from the radial inner side to the radial outer side, and smoothly transitions to the leading edge of the main blade at the trailing edge of the small blade portion.

6. An improved high performance fire pump as claimed in claim 5, characterized in that: The main blade leading edge (33) has a radius R, the small blade leading edge of the small blade portion (32) has a radius r, and the inner hole of the inlet ring (21) also has a radius r, where r=(0.7-0.9)R.

7. An improved high performance fire pump as claimed in claim 6, characterized in that: The main blade leading edge (33) has an axial width B, and the small blade portion (32) has a maximum axial width b, where b=(0.01-0.3)B.

8. An improved high performance fire pump as claimed in claim 7, characterized in that: The axial width B=(0.25-0.55)R.

9. An improved high performance fire pump as claimed in claim 6, characterized in that: A first arc-shaped flow guide portion is provided at the leading edge of the small blade portion (32), and a second arc-shaped flow guide portion is provided between the top edge of the small blade portion and the leading edge (33) of the main blade.

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