A high-efficiency axial flow fan for cooling tower

Abstract

The invention belongs to the technical field of cooling tower heat dissipation, and relates to a high-efficiency axial flow fan for a cooling tower. The chord length distribution curve of the axial flow fan blade is c(r)=0.03778r 2 ‑0.24456r+0.76228, where c(r) is the local chord length, r is the local radius, 0.52m≤r≤2.94m; torsion angle distribution curve β(r)=1.57687r 2 ‑10.4235r+4.61306, where β(r) is the local twist angle, r is the local radius, 0.52m≤r≤2.94m; the fan rotation radius is 2.94m, the blade length is 2.42m, and the blade chord length and twist angle are obtained by the formula; at the design speed of 165rpm, the total pressure of the axial flow fan for the cooling tower is 128Pa, the power is 34.5kW, and the flow rate is 750,000m 3 / h, efficiency greater than 77%.

Description

Technical Field

[0001] The invention belongs to the technical field of cooling tower heat dissipation, and relates to a high-efficiency axial flow fan for a cooling tower. Background Art

[0002] Cooling towers are widely used in real life, including injection molding, power generation, aluminum profile processing and steam turbines, but they are more commonly used in refrigeration, plastic chemicals and air conditioning cooling industries. Cooling towers make full use of the physical phenomenon of evaporative heat dissipation. During the evaporation process, excess heat generated in industrial production is dispersed to the external system.

[0003] The main components of the cooling tower include the shell, chassis, fan, demister, water distributor, etc. The working principle of the cooling tower is: the water pump relies on a certain pressure in the pipe, neck, throat and central throat, so that the circulating water can enter the water spreading device of the cooling tower under the action of pressure. Due to the action of the axial flow fan, low-temperature and low-humidity air is induced to flow into the cooling tower from the air inlet network. When the higher-temperature water passes over the filler, the water film generated can transfer heat with the air, and the air with higher humidity and temperature is discharged at the top of the cooling tower. In addition, the cooling water must be able to flow into the bottom basin. Therefore, the axial flow fan directly affects the cooling efficiency of the cooling tower. Summary of the invention

[0004] The purpose of the present invention is to design a high-efficiency axial flow fan for cooling towers, which can solve the current problem that the total pressure of axial flow fans for cooling towers is not less than 110Pa and the volume flow rate is not less than 750,000m 3 / h, the cooling efficiency of the cooling tower is improved to more than 75%.

[0005] To solve this technical problem, the technical solution of the present invention is:

[0006] A high-efficiency axial flow fan for a cooling tower, the axial flow fan comprising blades, a hub and a connecting rod; the blades are fixedly connected to the hub via the connecting rod, the number of the blades is 6, and the installation angle of the blades is 27.5° to 32.5°;

[0007] The chord length distribution curve of the axial flow fan blade c(r)=x1r 2 -x2r+x3, where c(r) is the local chord length, r is the local radius, 0.52m≤r≤2.94m, where:

[0008] 0.030≤x1≤0.040, 0.240≤x2≤0.250, 0.700≤x3≤0.760.

[0009] The axial fan blade torsion angle distribution curve β(r)=y1r 2-y2r+y3, where β(r) is the local torsion angle, r is the local radius, 0.52m≤r≤2.94m, where:

[0010] 1.500≤y1≤1.600, 10.000≤y2≤10.500, 4.200≤y3≤4.600.

[0011] The airfoil used for the blade is NACA4415 airfoil.

[0012] Furthermore, the blade installation angle is 29° to 31°; preferably, the blade installation angle is 30°.

[0013] The chord length distribution curve of the axial flow fan blade c(r)=0.03778r 2 -0.24456r+0.76228, where c(r) is the local chord length, r is the local radius, 0.52m≤r≤2.94m.

[0014] The axial fan blade torsion angle distribution curve β(r) = 1.57687r 2 -10.4235r+4.61306, where β(r) is the local torsion angle, r is the local radius, 0.52m≤r≤2.94m.

[0015] The fan has a rotation radius of 2.94m and a blade length of 2.42m. Under the conditions of a design speed of 165rpm and a power of 30kW to 35kW, the cooling tower axial fan has a total pressure of 128Pa and a flow rate of 750,000m 3 / h, efficiency not less than 77%.

[0016] The beneficial effect of the present invention is that: through numerical simulation calculation, it is found that when the volume flow rate is 750,000 m 3 / h, within the installation angle range of 27.5° to 32.5°, the total pressure variation range is 105.3Pa to 148.4Pa, and the efficiency is greater than 75%. It can be seen that the axial flow fan has a wider range of use. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the technical solutions implemented in the present invention, the following is a brief explanation of the drawings required to be used in the examples of the present invention. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative work.

[0018] Figure 1 A schematic diagram of a high-efficiency axial flow fan for a cooling tower of the present invention;

[0019] Figure 2It is a schematic cross-sectional view of a blade root of a high-efficiency axial flow fan for a cooling tower of the present invention;

[0020] In the figure, 1 is blade, 2 is connecting rod, and 3 is hub. DETAILED DESCRIPTION

[0021] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0022] The features of various aspects of the embodiments of the present invention will be described in detail below. In the detailed description below, many specific details are proposed to fully understand the present invention. However, it is obvious to those skilled in the art that the present invention can also be implemented without these specific details. The following description of the embodiments is only for a better understanding of the present invention by illustrating examples of the present invention. The present invention is not limited to any specific settings and methods provided below, but covers all product structures, any improvements, replacements, etc. of methods covered without departing from the spirit of the present invention.

[0023] In the various drawings and the following description, well-known structures and techniques are not shown to avoid unnecessarily obscuring the present invention.

[0024] like Figure 1 As shown in FIG. 1 , a high-efficiency axial flow fan for a cooling tower is composed of six blades 1, a connecting rod 2 and a hub 3. The installation angle of the fan blade 1 is α = 30°. Figure 2 As shown, the airfoil is a NACA4415 airfoil;

[0025] The chord length distribution curve of the axial flow fan blade 1 for the cooling tower is: c(r)=0.03778r 2 -0.24456r+0.76228, where c(r) is the local chord length, r is the local radius, 0.52m≤r≤2.94m, and the unit is m.

[0026] The torsion angle distribution curve of the axial flow fan blade 1 for the cooling tower is: β(r)=1.57687r 2 -10.4235r+4.61306, where β(r) is the local torsion angle, unit: °, and r is the local radius, 0.52m≤r≤2.94m.

[0027] The fan has a rotation radius of 2.94m, a blade 1 length of 2.42m, and a blade root at a radial position of 0.52m from the rotation center. The blade 1 is fixedly connected to the hub 3 via a connecting rod 2. At a design speed of 165rpm, the cooling tower axial fan has a total pressure of 128Pa and a flow rate of 750,000m 3 / h, efficiency is greater than 77%, and the required power is 34.5kW.

[0028] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the field can easily think of various equivalent modifications or substitutions within the technical scope disclosed by the present invention, and these modifications or substitutions should all be covered within the protection scope of the present invention.

Claims

1. A high-efficiency axial flow fan for a cooling tower, characterized in that: The axial flow fan comprises blades, a hub and a connecting rod; the blades are fixedly connected to the hub via the connecting rod, the number of blades is 6, and the installation angle of the blades is 27.5°~32.5°; Axial fan blade chord length distribution curve ,in, is the local chord length, is the local radius, ,in: 0.030≤x1≤0.040, 0.240≤x2≤0.250, 0.700≤x3≤0.760; The axial flow fan blade torsion angle distribution curve ,in, is the local twist angle, is the local radius, ,in: 1.500≤y1≤1.600, 10.000≤y2≤10.500, 4.200≤y3≤4.600; The airfoil used for the blade is NACA4415 airfoil.

2. The axial flow fan according to claim 1, characterized in that: The blade installation angle is 29°~31°.

3. The axial flow fan according to claim 1, characterized in that: The blade installation angle is 30°.

4. The axial flow fan according to claim 1, characterized in that: The rotation radius of the axial flow fan is 2.94m.

5. The axial flow fan according to claim 1, characterized in that: Blade length 2.42m.

Images