A design method for a pump casing, a pump, and an extended high-efficiency range of the pump.

Abstract

This invention relates to a pump casing, a pump, and a design method for extending the pump's high-efficiency zone. The pump includes a pump casing and an impeller. The pump casing includes an inlet, a pressure chamber, and a tongue. The pressure chamber communicates with the inlet and includes a diffuser section and a spiral section. A throat is formed at the connection point of the diffuser section and the spiral section. The tongue is positioned between the diffuser section and the spiral section, with an installation angle α of 41.5°–54.6°. The tongue is located on one side of a reference plane to increase the throat height h. The reference plane is configured to pass through the impeller's rotation axis and is perpendicular to the end face of the inlet. By adjusting the installation angle α of the tongue, it is positioned on one side of the reference plane, ensuring that the liquid flow velocity through the throat is slowed down, reducing the impact force on the tongue, suppressing eddy current losses, and also widening the high-efficiency zone. The design method for extending the pump's high-efficiency zone determines the range of the tongue's installation angle α and coefficient k through simulation. Within this range, the pump exhibits better operating performance and a wider high-efficiency zone.

Description

Technical Field

[0001] This invention relates to the field of pump technology, and in particular to a design method for a pump casing, a pump, and a method for extending the pump's high-efficiency range. Background Technology

[0002] The width of a pump's high-efficiency operating range mainly depends on the hydraulic matching relationship between the impeller and the volute. The matching ratio between the throat area of ​​the volute and the critical flow area of ​​the impeller is the core key parameter that determines the flow field stability, hydraulic loss, and coverage of the high-efficiency zone under full flow conditions.

[0003] In existing technologies, during the hydraulic design and modification optimization of pumps, the industry generally uses the ratio of the throat area of ​​the volute to the flow area of ​​the impeller outlet as the core control basis for hydraulic matching design. By limiting this ratio, the pump achieves a partial adaptation between the impeller outlet velocity and the volute inflow velocity at the rated design flow point, ensuring that the pump has basic hydraulic performance under rated operating conditions. This matching method only performs local flow adaptation at the rated design flow point. Once the pump's operating conditions deviate from the rated conditions, the flow capacity of the impeller outlet and the volute throat quickly becomes mismatched. Under deviated operating conditions, hydraulic impact losses and eddy current secondary flow losses increase sharply, resulting in a naturally narrow high-efficiency operating range for the pump, making it impossible to effectively extend to low-flow and high-flow ranges.

[0004] Therefore, there is an urgent need for a design method for pump casing, pump, and pump with an extended high-efficiency range, in order to solve the above-mentioned technical problems. Summary of the Invention

[0005] The first objective of this invention is to provide a pump housing that at least solves one of the aforementioned problems.

[0006] To achieve the above objectives, the present invention provides a pump housing, comprising: Liquid inlet; A pressure chamber is connected to the liquid inlet. The pressure chamber includes a diffuser section and a spiral section. A throat is formed at the connection between the diffuser section and the spiral section. A tongue is provided between the diffuser section and the spiral section. The installation angle α of the tongue is 41.5°-54.6°, and the tongue is located on one side of the reference plane to increase the height h of the throat. The reference plane is configured to pass through the rotation axis of the impeller and be perpendicular to the end face of the inlet.

[0007] Furthermore, the width b of the throat satisfies the following relationship: ; In the formula, b is the width of the throat, b3 is the width of the pressure chamber, and k is a coefficient, with a value ranging from 1 to 1.2.

[0008] Furthermore, the coefficient k is 1.

[0009] Furthermore, the ratio X of the area of ​​the throat to the area of ​​the impeller inlet ranges from 0.6 to 0.8.

[0010] Furthermore, the installation angle α of the tongue is 43.7°.

[0011] A second objective of the present invention is to provide a pump that at least solves one of the aforementioned problems.

[0012] To achieve the above objectives, the present invention provides a pump, comprising: Pump casing as described in any of the above embodiments; An impeller is located in the pressure chamber.

[0013] A third objective of this invention is to provide a design method for extending the high-efficiency range of a pump, so as to at least solve one of the above-mentioned problems.

[0014] To achieve the above objectives, the present invention provides a design method for widening the high-efficiency range of a pump, comprising the following steps: Step S1: Based on the pump's design flow rate Q d The width b3 of the pressure chamber is obtained by calculating the design head H and the design speed n. Step S2: Simulate using the installation angle α and coefficient k of the tongue separator as variables to obtain the width of the high-efficiency zone for the corresponding working condition. The high-efficiency zone is the area where the efficiency is not less than m% of the highest efficiency. Step S3: Filter out the working condition group based on the target value that the width of the high-efficiency zone is greater than or equal to the target value, and analyze the working condition group to obtain the range of the installation angle α and coefficient k of the tongue separator.

[0015] Furthermore, m=92.

[0016] Furthermore, the target value is 1.5 to 1.57 times the width of the high-efficiency zone of a conventional pump.

[0017] The beneficial effects of this invention are as follows: The pump provided by the present invention includes a pump casing and an impeller. The pump casing includes an inlet, a pressure chamber, and a tongue. The pressure chamber is connected to the inlet and includes a diffuser section and a spiral section. A throat is formed at the connection between the diffuser section and the spiral section. The tongue is disposed between the diffuser section and the spiral section. The installation angle α of the tongue is 41.5°-54.6° and the tongue is located on one side of a reference plane to increase the height h of the throat. The reference plane is configured to pass through the rotation axis of the impeller and be perpendicular to the end face of the inlet. By adjusting the installation angle α of the tongue separator, the tongue separator is positioned on one side of the reference plane, ensuring that the liquid flow velocity through the throat is slowed down, reducing the impact force on the tongue separator, and suppressing eddy current losses. By adjusting the range of the installation angle α of the tongue separator, the height h of the throat is increased, thereby increasing the area of ​​the throat. This allows the pump to maintain high operating efficiency even when deviating from its rated operating conditions, widening the high-efficiency operating range, i.e., the width of the high-efficiency zone. The pump can effectively extend to both low and high flow ranges, making the pump more adaptable, reducing energy losses during variable operating conditions, and meeting the needs of energy conservation and consumption reduction.

[0018] The design method for extending the high-efficiency range of a pump provided by this invention, and the pump itself, include the following steps: Step S1: Based on the pump's design flow rate Q d The width b3 of the pressure chamber is obtained by calculating the design head H and the design speed n. Step S2: Simulate using the installation angle α and coefficient k of the tongue separator as variables to obtain the width of the high-efficiency zone for the corresponding working condition. The high-efficiency zone is the area where the efficiency is not less than m% of the highest efficiency. Step S3: Filter out the operating condition group based on the target value that the width of the high-efficiency zone is greater than or equal to the target value; Step S4: Analyze the working condition group to obtain the range of the installation angle α and coefficient k of the tongue separator.

[0019] Furthermore, m=92.

[0020] Furthermore, the target value is 1.5 to 1.57 times the width of the high-efficiency zone of a conventional pump.

[0021] Simulations revealed the range of the installation angle α and coefficient k of the tongue separator. Within this range, the pump exhibited good operating performance, and the width of the high-efficiency zone was effectively broadened. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of the pump provided in an embodiment of the present invention; Figure 2 This is a top view of the pump provided in an embodiment of the present invention; Figure 3 The pump edge provided in the embodiment of the present invention Figure 2 A sectional view cut by section AA; Figure 4 The pump edge provided in the embodiment of the present invention Figure 2 A sectional view cut by section BB; Figure 5 This is a front view of the pump provided in an embodiment of the present invention; Figure 6 The pump edge provided in the embodiment of the present invention Figure 5 A cross-sectional view cut by CC. Figure 7 These are the flow-efficiency curves obtained from simulations of the embodiments and comparative examples 1-3 of this invention; Figure 8 These are the flow-efficiency curves obtained from simulations of the embodiments and comparative examples 4-6 of this invention; Figure 9 These are the flow-efficiency curves obtained from simulations of embodiments and comparative examples 7-11 of this invention.

[0023] In the picture: 100, Pump; 200, Reference plane; 300, End face; 400, Rotation axis; VIII, Eighth section; 1. Pump casing; 11. Inlet; 12. Pressure chamber; 121. Spiral section; 122. Diffuser section; 123. Outlet; 13. Throat; 14. Tongue; 2. Impeller. Detailed Implementation

[0024] The technical solution of the present invention will be further described below with reference to the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and not intended to limit it. Furthermore, it should be noted that, for ease of description, only the parts relevant to the present invention are shown in the accompanying drawings, not all of them.

[0025] This invention defines certain directional terms. Unless otherwise stated, the directional terms used, such as "up," "down," "left," "right," "inner," and "outer," are used for ease of understanding and therefore do not constitute a limitation on the scope of protection of this invention.

[0026] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0027] In the description of this invention, unless otherwise explicitly specified and limited, the terms "connected," "linked," and "fixed" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0028] like Figures 1-6 As shown, this embodiment provides a pump 100, which includes a pump casing 1 and an impeller 2. The pump casing 1 includes an inlet 11, a pressure chamber 12, and a tongue 14. The pressure chamber 12 is connected to the inlet 11 and includes a diffuser section 122 and a spiral section 121. A throat 13 is formed at the connection between the diffuser section 122 and the spiral section 121. The tongue 14 is disposed between the diffuser section 122 and the spiral section 121. The installation angle α of the tongue 14 is 41.5°-54.6°, and the tongue 14 is located on one side of the reference plane 200 to increase the height h of the throat 13. The reference plane 200 is configured to pass through the rotation axis 400 of the impeller 2 and be perpendicular to the end face 300 of the inlet 11. By adjusting the installation angle α of the tongue 14, the tongue 14 is positioned on one side of the reference plane 200, ensuring that the speed of the liquid flowing through the throat 13 is slowed down, reducing the impact force on the tongue 14, and suppressing eddy current losses. By adjusting the range of the installation angle α of the tongue 14, the height h of the throat 13 is increased, thereby increasing the area of ​​the throat 13. This allows the pump 100 to maintain high operating efficiency even when deviating from its rated operating conditions, widening the high-efficiency operating range, i.e., the width of the high-efficiency zone. The pump 100 can effectively extend to both small and large flow ranges, making the pump 100 more adaptable, reducing energy losses during variable operating conditions, and meeting the needs of energy conservation and consumption reduction.

[0029] Preferably, the installation angle α of the tongue 14 is 43.7°.

[0030] Furthermore, the pressure chamber 12 is provided with an outlet 123, which is located at the end of the diffuser section 122 away from the spiral section 121, and the liquid flows out of the pump casing 1 from the outlet 123.

[0031] In this embodiment, the axis of outlet 123 coincides with the axis of inlet 11, and both extend radially along the spiral section 121. This arrangement makes the pump 100 more compact, with a smaller horizontal footprint, allowing direct connection to a piping system without the need for elbows or reducers, thus reducing resistance and energy consumption. The coaxial design reduces unnecessary fluid turning impacts, making the fluid flow more smoothly within the pump 100 and avoiding eddies and energy losses caused by sudden changes in the flow path.

[0032] Furthermore, the width b of the throat 13 satisfies the following relationship: ; In the formula, b is the width of the throat 13, b3 is the width of the pressure chamber 12, and k is a coefficient, with a value range of 1-1.2.

[0033] The value range of coefficient k directly affects the width b of throat 13, and has a significant impact on increasing the area of ​​throat 13. When the value range of coefficient k is 1-1.2, it can ensure the smooth continuity of the flow channels of diffuser section 122 and spiral section 121, making them more in line with the flow law of fluid, and also meet the diffusion requirements. This allows the fluid to be appropriately pressurized when flowing through throat 13, reducing the fluid velocity and flow loss. This allows pump 100 to maintain high operating efficiency even when deviating from rated operating conditions, thus widening the high-efficiency zone.

[0034] Preferably, the coefficient k is 1.

[0035] Furthermore, the ratio X of the area of ​​the throat 13 to the area of ​​the impeller 2 inlet ranges from 0.6 to 0.8.

[0036] Let the area of ​​throat 13 be F3, and the area of ​​impeller 2 inlet be F1, then we have: ; ; In the formula, D j This is the diameter of the inlet of impeller 2.

[0037] The ratio X of the area of ​​throat 13 to the inlet area of ​​impeller 2 is: ; In conventional pumps, the ratio X of the throat area to the impeller inlet area is 0.35-0.5. In the pump 100 provided in this embodiment, the ratio X of the throat area 13 to the impeller inlet area is 0.6-0.8, which is mainly achieved by increasing the throat area F3.

[0038] This embodiment also provides a design method for widening the high-efficiency range of pump 100, including the following steps: Step S1: Based on the design flow rate Q of pump 100 d The width b3 of the pressure chamber 12 is obtained by calculating the design head H and the design speed n. Step S2: Simulate using the installation angle α and coefficient k of tongue 14 as variables to obtain the width of the high-efficiency zone for the corresponding working condition. The high-efficiency zone is the area where the efficiency is not less than m% of the highest efficiency. Step S3: Filter out the working condition group based on the target value that the width of the high-efficiency zone is greater than or equal to the target value, and analyze the working condition group to obtain the range of the installation angle α and coefficient k of the tongue 14.

[0039] Furthermore, m=92.

[0040] Furthermore, the target value is 1.5 to 1.57 times the width of the high-efficiency zone of a conventional pump.

[0041] In step S1, the design flow rate Q is used. d =5m 3 Taking a design head of H=12m and a design speed of n=5000rpm as an example, hydraulic calculations show that the width of the pressure chamber, b3, is 16mm. Simultaneously, the inlet diameter D of impeller 2 can be obtained. j =30mm, the outlet diameter of impeller 2 is D2=60mm.

[0042] In step S2, the parameter data of the throat in each simulation are shown in Table 1: Table 1. Data on throat parameters in each simulation.

[0043] The flow rate Q-efficiency η curves obtained from various simulations are as follows: Figures 7-9 As shown. The width of the high-efficiency zone can be obtained by calculating the distance between the boundary of the high-efficiency zone and the intersection point of the flow rate Q-efficiency η curve for each operating condition.

[0044] In step S3: In conventional design, the installation angle α of the tongue separator is the angular parameter of the initial circumferential position of the tongue separator, and its magnitude is mainly determined based on the pump's specific speed. When the design flow rate Q... d =5m 3 When the design head H=12m and the design speed n=5000rpm, the installation angle α of the tongue is calculated to be 15°-25° based on the pump's specific speed. In this embodiment, the installation angle α of the tongue 14 is much larger than the value obtained by conventional calculation. The size of the installation angle α of the tongue 14 is related to the height h of the throat 13, and is also related to the internal flow field and energy loss of the pump 100. If the installation angle α of the tongue 14 is too small, it will lead to enhanced dynamic and static interference between the circulating flow and the tongue 14, and also increase the hydraulic loss and energy loss of the pump 100. If the installation angle α of the tongue 14 is too large, it will make the velocity of the fluid flowing through the tongue 14 too slow, affecting the smoothness of the flow, and causing large-scale vortices and backflows to be generated in the diffuser section 122. These vortices and backflows will affect the flow state of the throat 13 in the opposite direction.

[0045] like Figure 7 and Figure 8As shown, the coefficient k=1, and the installation angle α of the tongue 14 is the only variable.

[0046] exist Figure 7 In this embodiment and Comparative Examples 1-3, the installation angle α of the tongue 14 gradually decreases. When the installation angle α of the tongue 14 is 41.5°, the tongue 14 is exactly tangent to the reference plane 200, that is, the tongue 14 is located at the critical point on one side and both sides of the reference plane 200. Figure 7 It can be seen that the larger the installation angle α of the tongue 14, the larger the height h of the throat 13 (combined with...). Figure 6 The highest efficiency of this embodiment is basically the same as that of Comparative Examples 1-3. The width of the high-efficiency zone in Comparative Example 1 is not much different from the width of the high-efficiency zone in this application. The width of the high-efficiency zone in Comparative Examples 2 and 3 decreases in turn, indicating that the installation angle α of the tongue 14 increases and the width of the high-efficiency zone increases.

[0047] exist Figure 8 In this embodiment and in comparative examples 4-6, the installation angle α of the tongue 14 gradually increases. The tongue 14 is located on one side of the reference plane 200. The larger the installation angle α of the tongue 14, the larger the height h of the throat 13 (in conjunction with...). Figure 6 The highest efficiency of this embodiment and Comparative Examples 4-5 is not much different, but the highest efficiency of Comparative Example 6 drops sharply, and even tends to be lower than the lowest efficiency of the high efficiency zone. The width of the high efficiency zone of this embodiment and Comparative Examples 4-6 decreases in turn, indicating that after the installation angle α of the tongue 14 increases to a certain extent, further increasing it will actually reduce the width of the high efficiency zone.

[0048] Figure 7 and Figure 8 The comparison shows that the width of the high-efficiency zone in Comparative Example 3 is smaller than that in Comparative Example 6. Considering the positional relationship between the tongue 14 and the reference plane 200, it can be seen that when the tongue 14 is located on one side of the reference plane 200, the pump 100 performs better in widening the high-efficiency zone. Therefore, the trend and pattern of the installation angle α of the tongue 14 in widening the high-efficiency zone is as follows: as the installation angle α of the tongue 14 gradually increases, the width of the high-efficiency zone first increases and then decreases, with the inflection point at the installation angle α = 43.7°. That is, appropriately increasing the installation angle α of the tongue 14 can widen the width of the high-efficiency zone. However, after the installation angle α of the tongue 14 increases beyond the inflection point, the width of the high-efficiency zone of the pump 100 actually narrows. Moreover, when the tongue 14 is located on one side of the reference plane 200, the pump 100 performs better overall in widening the width of the high-efficiency zone. This is because increasing the installation angle α of the tongue 14 will increase the height h of the throat 13, slowing down the velocity of the liquid flowing through the throat 13, reducing the impact force on the tongue 14, suppressing eddy current losses, and causing the maximum efficiency point to shift towards the high flow rate condition. However, excessively increasing the installation angle α of the tongue 14 will offset this positive effect.

[0049] Based on the simulation results and the selection criteria, the installation angle α of the tongue 14 is found to be in the range of 41.5°-54.6°, and the preferred installation angle α of the tongue 14 is 43.7°.

[0050] like Figure 9 As shown, the installation angle of the tongue separator is α = 43.7°, and the coefficient k is the only variable. In Comparative Examples 8, 7, this embodiment, and 9-11, the value of k increases sequentially, and the width of the high-efficiency zone first increases and then decreases, with the inflection point being k = 1. In this embodiment, Comparative Example 9, and 10, the width of the high-efficiency zone is not significantly different, and the highest efficiency also first increases and then decreases, with the inflection point also being k = 1. In Comparative Example 11, the highest efficiency drops sharply, and the highest efficiency in Comparative Example 11 even has a portion that is lower than the lowest efficiency of the high-efficiency zone.

[0051] Therefore, the trend and pattern of k in widening the high-efficiency zone is as follows: as the value of k increases, the width of the high-efficiency zone first increases and then decreases, with the inflection point being k=1. This is because increasing k increases the width b of the throat 13, slowing down the velocity of the liquid flowing through the throat 13, reducing the impact force on the tongue 14, suppressing eddy current losses, and causing the maximum efficiency point to shift towards the high-flow-rate condition. However, excessively increasing k will offset this positive effect.

[0052] Based on the simulation results and the selection criteria, the value range of k is 1-1.2, and the optimal value of k is 1.

[0053] The width of the high-efficiency zone of a conventional pump, ΔQ, is related to the design flow rate, Q. d The ratio is 0.69. When the installation angle α of the tongue 14 is within the range of 41.5°-54.6°, the width ΔQ of the high-efficiency zone of the pump 100 is related to the design flow rate Q. d The ratio is 0.85-1; when k is in the range of 1-1.2, the width ΔQ of the high-efficiency zone of pump 100 is related to the design flow rate Q. d The ratio is 0.8-0.97. Therefore, it can be seen that when widening the high-efficiency zone, the installation angle α of the tongue 14 has a slightly greater impact than the coefficient k.

[0054] The target value is selected as 1.5 to 1.57 times the width of the high-efficiency zone of a conventional pump because the high-efficiency zone of pump 100 can not only have high efficiency performance in the selected operating conditions within this range, but also maintain a high width of the high-efficiency zone, so that pump 100 can be more adaptable to variable flow conditions and reduce energy consumption.

[0055] Simulations revealed the range of the installation angle α and coefficient k of the tongue 14. Within this range, the pump exhibits good operating performance, and the width of the high-efficiency zone is effectively broadened.

[0056] Although the present invention has been described in detail above with general descriptions, specific embodiments, and experiments, modifications or improvements can be made to it, which will be obvious to those skilled in the art. Therefore, all such modifications or improvements made without departing from the spirit of the present invention fall within the scope of protection claimed by the present invention.

Claims

1. A pump casing, characterized in that, include: Liquid inlet (11); The pressure chamber (12) is connected to the liquid inlet (11). The pressure chamber (12) includes a diffuser section (122) and a spiral section (121). A throat (13) is formed at the connection between the diffuser section (122) and the spiral section (121). A tongue (14) is provided between the diffuser section (122) and the spiral section (121). The installation angle α of the tongue (14) is 41.5°-54.6°, and the tongue (14) is located on one side of the reference plane (200) to increase the height h of the throat (13). The reference plane (200) is configured to pass through the rotation axis (400) of the impeller (2) and be perpendicular to the end face (300) of the inlet (11).

2. The pump casing according to claim 1, characterized in that, The width b of the throat (13) satisfies the following relationship: ； In the formula, b is the width of the throat (13), b3 is the width of the pressure chamber (12), and k is a coefficient, with a value range of 1-1.

2.

3. The pump casing according to claim 2, characterized in that, The coefficient k is 1.

4. The pump casing according to claim 2, characterized in that, The ratio X of the area of ​​the throat (13) to the area of ​​the inlet of the impeller (2) ranges from 0.6 to 0.

8.

5. The pump casing according to claim 1, characterized in that, The installation angle α of the tongue (14) is 43.7°.

6. A pump, characterized in that, include: Pump casing (1) as described in any one of claims 1-5; Impeller (2), which is located in the pressure chamber (12).

7. A design method for extending the high-efficiency range of a pump, characterized in that, Includes the following steps: Step S1: Based on the design flow rate Q of pump (100) d The width b3 of the pressure chamber (12) is obtained by calculating the design head H and the design speed n; Step S2: Simulate using the installation angle α and coefficient k of the tongue (14) as variables to obtain the width of the high-efficiency zone for the corresponding working condition. The high-efficiency zone is the area where the efficiency is not less than m% of the highest efficiency. Step S3: Select the working condition group with the width of the high efficiency zone being greater than or equal to the target value, and analyze the working condition group to obtain the range of the installation angle α and coefficient k of the tongue (14).

8. The design method for widening the high-efficiency range of the pump according to claim 7, characterized in that, m=92。 9. The design method for widening the high-efficiency range of the pump according to claim 7, characterized in that, The target value is 1.5 to 1.57 times the width of the high-efficiency zone of a conventional pump.

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