Backward high-pressure centrifugal fan based on CFD simulation design
By optimizing the blade structure of the backward impeller through CFD simulation design, the problems of large eddy current separation loss and low efficiency in high-pressure centrifugal fans were solved, and more efficient and lower-cost impeller manufacturing was achieved.
Patent Information
- Application Number
- CN202423145779.4
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-12-19
- Publication Date
- 2025-11-07
- Estimated Expiration
- 2034-12-19
AI Technical Summary
Existing high-pressure centrifugal fan impeller designs suffer from problems such as large eddy current separation losses, low efficiency, high cost, and long cycle time. Furthermore, there is a lack of mature experience in backward impeller design, and CFD simulation design is inefficient.
A backward-curved impeller based on CFD simulation design is adopted, with blade oblique angles of 35~75°, inlet angles of 25~45°, and outlet angles of 40~65°. The impeller structure profile is optimized through joint optimization design using Solidworks and CFD software.
Reduce eddy separation losses, improve fan pressure and efficiency, and reduce impeller processing costs and cycle time.
Smart Images
Figure CN223524002U_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The utility model relates to high pressure centrifugal fan field especially relates to a backward high pressure centrifugal fan based on CFD simulation design. BACKGROUND
[0002] Centrifugal fan as a kind of common high efficiency, stable performance gas transport device, is widely used in industry, environmental protection, chemical industry and each field, it is also one of main energy-consuming equipment.National energy conservation and environmental protection policy requires centrifugal fan to the high efficiency low consumption direction development, therefore, research optimization centrifugal fan, improve fan efficiency, it is the important development direction of energy saving and emission reduction, sustainable development strategy.
[0003] Centrifugal fan is mainly composed of air inlet, impeller, volute three parts, the structure line of three plays a key role to the flow field of fan, and impeller as the core component of fan, directly influence fan performance parameter.At present, the impeller blade of high pressure centrifugal fan is mainly forward impeller, forward impeller airflow impacts blade, and the vortex separation loss in flow passage is larger, fan pressure is high but efficiency is low, and the outer end of forward blade is curved arc, curvature radius is small, high cost, great difficulty, long cycle from manufacturing process.And for the application of backward impeller in high pressure centrifugal fan lacks mature experience, need to use numerical simulation method to understand the internal flow field of fan, and carry out structural optimization design, generally need to first establish fan structure three-dimensional model according to experience value and then carry out CFD analysis to obtain performance parameter, when the result does not meet the requirement, need to repeat modeling simulation several times, can only find the highest pressure and efficiency fan structure line, workload is large and time-consuming, and there is omission, therefore, currently, there is few backward high pressure centrifugal fan based on CFD simulation design. UTILITARY MODEL CONTENT
[0004] The utility model aims at providing a backward high pressure centrifugal fan based on CFD simulation design, adopt backward impeller, impeller flow passage airflow is more smooth, reduces vortex separation loss, improves fan pressure and efficiency.
[0005] The utility model discloses a technical scheme adopted for solving the above technical problem is: a backward high pressure centrifugal fan based on CFD simulation design, including volute, the impeller in volute inside and the main shaft for driving impeller rotation, the impeller is backward impeller, and the impeller includes front disc and a plurality of blades, and the side of front disc is towards air inlet, and air inlet is installed in the side wall of volute, and the front side of a plurality of blades is connected with front disc respectively, and the front side of blade is oblique cut from front disc along the direction of being away from front disc and being away from main shaft, and the oblique cutting angle of oblique surface is 35~75 DEG with respect to the main shaft axis, a plurality of blades are arranged along the circumferential direction of impeller and are uniformly spaced, and define the end of blade close to main shaft as inlet end and the end away from main shaft as outlet end, define the included angle between the tangent of blade surface of front side inlet end and the tangent of concentric circle on front disc passing through front side inlet end as front side type line inlet angle, and the front side type line inlet angle is 25~45 DEG, define the included angle between the tangent of blade surface of front side outlet end and the tangent of concentric circle on front disc passing through front side outlet end as front side type line outlet angle, and the front side type line outlet angle is 40~65 DEG.
[0006] Preferably, the number of blades is n, and 12≤n≤16.
[0007] According to the above technical scheme, the utility model has the beneficial effects that:
[0008] The utility model adopts backward impeller, and the flow passage airflow of impeller is more smooth, reduces vortex separation loss, improves fan pressure and efficiency, and the oblique cutting angle, inlet angle and outlet angle of blade are all based on CFD simulation design, adopt reasonable fan structure type line, reduce impeller processing cost and manufacturing period. BRIEF DESCRIPTION OF DRAWINGS
[0009] Figure 1 It is fan schematic drawing of the utility model;
[0010] Figure 2 It is blade angle schematic drawing.
[0011] Mark in drawing: 1, volute, 2, impeller, 3, air inlet, 4, blade. DETAILED DESCRIPTION
[0012] Referring to the drawings, the specific implementation is as follows:
[0013] For example, Figure 1As shown, a backward high-pressure centrifugal fan based on CFD simulation design includes a volute 1, an impeller 2 located inside the volute 1 and a main shaft for driving the impeller 2 to rotate, the impeller 2 is a backward impeller, the impeller 2 includes a front disc and a plurality of blades 4, the number of blades 4 is 12 to 16, one side of the front disc faces the air inlet 3, the air inlet 3 is inserted and installed on the side wall of the volute 1, the front side of the plurality of blades 4 is connected with the front disc respectively, the front side of the blade 4 is chamfered from the front disc along the direction away from the front disc and away from the main shaft, the chamfering angle of the chamfering surface relative to the main shaft axis is 35~75°.
[0014] As shown, Figure 2 The plurality of blades 4 are uniformly spaced along the circumference of the impeller 2, the end of the blade 4 close to the main shaft is defined as the inlet end and the end away from the main shaft is defined as the outlet end, the included angle between the tangent of the blade surface at the inlet end of the front side and the tangent of the concentric circle on the front disc passing through the inlet end of the front side is defined as the front side profile inlet angle, the front side profile inlet angle is 25~45°, the included angle between the tangent of the blade surface at the outlet end of the front side and the tangent of the concentric circle on the front disc passing through the outlet end of the front side is defined as the front side profile outlet angle, the front side profile outlet angle is 40~65°.
[0015] The geometric structure profile of the blade 4 in this embodiment is obtained by using Solidworks and CFD simulation software jointly automatic optimization, the design process includes the following steps:
[0016] Step 1: Use CFD software to simulate and analyze the original forward high-pressure small-flow fan to obtain its pressure and efficiency.
[0017] Step 2: Model pre-processing: establish a three-dimensional model of the backward high-pressure small-flow fan in Solidworks, set the structure variables (geometric dimensions of the front disc, blade, air inlet, etc.).
[0018] Step 3: Associate Solidworks and CFD software, use the variables in step 2 as decision parameters in CFD software, set the upper and lower limits of the decision parameters.
[0019] Step 4: Perform normal simulation in CFD, add output parameters (pressure, efficiency) in the experimental design module, and automatically generate a parameter set (combination of dozens of different variables) from the decision parameters and output parameters. First, simulate and calculate 10-15 steps to verify the correctness of the three-dimensional model and system (no error in each variable in the parameter set).
[0020] Step 5: Based on the correct premise of step 4, return to CFD to continue simulation and calculation until the model converges.
[0021] Step 6: Looking at the results of the experimental design module of the CFD software, the pressure and efficiency values under different combinations can be seen, as well as the corresponding three-dimensional model geometry (front disc, blade and inlet), which is compared with the original model parameters in step 1 to find the optimal profile combination.
[0022] In the above automatic optimization process, the fan three-dimensional model changes with the combination of the CFD parameter set, and finally a reasonable fan structure profile is obtained, which reduces the cost and production cycle of the impeller machining, the flow channel of the backward impeller is smoother, the vortex separation loss is reduced, and the fan pressure and efficiency are improved.
Claims
1. A backward high pressure centrifugal fan based on CFD simulation design, comprising a volute (1), an impeller (2) located inside the volute (1) and a main shaft for driving the impeller (2) to rotate, characterized in that: The impeller (2) is a backward impeller, the impeller (2) comprises a front disc and a plurality of blades (4), one side of the front disc faces the air inlet (3), the air inlet (3) is inserted and installed on the side wall of the volute (1), the front side of each blade (4) is connected with the front disc, the front side of the blade (4) is obliquely cut from the front disc in a direction away from the front disc and the main shaft, and the oblique cutting angle of the oblique cutting surface relative to the main shaft axis is 35-75°; the plurality of blades (4) are uniformly and spacedly arranged along the circumference of the impeller (2), the end of the blade (4) close to the main shaft is defined as an inlet end, and the end away from the main shaft is defined as an outlet end, the included angle between the tangent of the blade curve surface of the inlet end of the front side and the tangent of the concentric circle on the front disc passing through the inlet end of the front side is defined as the inlet angle of the front side profile line, the inlet angle of the front side profile line is 25-45°, and the included angle between the tangent of the blade curve surface of the outlet end of the front side and the tangent of the concentric circle on the front disc passing through the outlet end of the front side is defined as the outlet angle of the front side profile line, the outlet angle of the front side profile line is 40-65°.
2. A backward high pressure centrifugal fan based on CFD simulation design according to claim 1, characterized in that: The number of the blades (4) is n, and 12≤n≤16.