Manufacturing method of double-baffle-tongue volute for centrifugal pump and double-baffle-tongue volute

Abstract

The invention discloses a manufacturing method of a double-baffle-tongue volute for a centrifugal pump and the double-baffle-tongue volute, and aims to provide the double-baffle-tongue volute for the centrifugal pump, which is used for improving the poor flow phenomenon of the centrifugal pump, improving the efficiency and the stability, optimizing the flow state of an internal flow field, reducing the energy consumption, reducing the pulsation characteristic and improving the performance of the centrifugal pump. According to the technical scheme, the manufacturing method is characterized by comprising the steps of integrated blank preparation, preliminary quality detection and finish machining, separation tongue gap detection, cooling, qualified product surface strengthening treatment, residual stress detection, bullet breakage rate detection and performance detection. And unqualified products can be found in time, the products which can be trimmed can be trimmed, the quality of the products is ensured, and the reliability and the stability of the products are improved. The invention is suitable for the technical field of centrifugal pumps.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of centrifugal pumps, more particularly, it relates to a manufacturing method of a double-tongue volute for a centrifugal pump and the double-tongue volute. BACKGROUND

[0002] In the working process of a centrifugal pump, the impeller rotates at high speed to drive fluid movement, and the fluid flow in the pump casing is relatively complex, which is prone to adverse flow phenomena such as vortex, secondary flow and boundary separation. These phenomena will cause a large amount of energy loss of the fluid, reduce the efficiency of the centrifugal pump, and also cause vibration and noise of the pump body, affecting its stable operation. Therefore, developing a double-tongue volute for a centrifugal pump that can effectively suppress adverse flow phenomena, improve efficiency and stability, optimize the flow state of the internal flow field, reduce energy consumption, reduce pulsation characteristics, and enhance reliability and comfort has become the focus of current research. SUMMARY

[0003] In view of the deficiencies of the prior art, the purpose of the present application is to provide a manufacturing method of a double-tongue volute for a centrifugal pump and the double-tongue volute, which can suppress adverse flow phenomena, improve efficiency and stability, optimize the flow state of the internal flow field, reduce energy consumption, reduce pulsation characteristics, and enhance reliability and comfort.

[0004] To achieve the above-mentioned purpose, the present application provides the following technical scheme: a manufacturing method of a double-tongue volute for a centrifugal pump, comprising the following steps:

[0005] S1, preparation of an integrated blank: using precision investment casting technology, a volute integrated blank containing a first tongue and a second tongue preliminary structure is prepared, so that the radial gap C1 of the first tongue and the impeller is less than the radial gap C2 of the second tongue and the impeller;

[0006] S2, preliminary quality detection and finishing: scanning the volute blank by industrial CT, calculating the porosity in the CT scan image, measuring the wall thickness of the key positions of the flow channel, and finishing and polishing the integrated blank that passes the detection:

[0007] When the porosity is lower than the first threshold value A, and the wall thickness is within the design tolerance range, it is determined that the blank is qualified, and it flows into the finishing process;

[0008] When the porosity is between the threshold value A and a higher threshold value B, it is determined that it is a repairable product, the defect area is repaired by micro-arc welding process, CT scanning is performed again, and the same determination logic is executed to ensure that the defect has been eliminated to the qualified level;

[0009] When the porosity is higher than the threshold value B or the wall thickness is seriously out of tolerance, it is determined that it is a waste product;

[0010] S3, the gap detection between the lips: after the milling of the integrally formed blank profile, the head key point coordinates of the first and second lips are measured in real time using the in-machine laser measuring head, the actual radial gaps C1 and C2 are calculated based on the measuring point coordinates, and the ratio C1 / C2 is calculated according to the three-dimensional digital model:

[0011] When C1 is less than C2, and the value of C1 / C2 is between 2 / 5 and 5 / 6, it is determined to be qualified;

[0012] When C1 is greater than C2 or the value of C1 / C2 is not within the range of 2 / 5 to 5 / 6, it is determined to be repaired, and if three unqualified products appear continuously within T time, the recorded parameters are read, and the device parameters need to be adjusted:

[0013] When C1 and C2 increase or decrease synchronously, the wear of the tool is checked, and the tool length and radius compensation parameters are adjusted to be smaller;

[0014] When the ratio of C1 / C2 continuously deviates and the direction is consistent, the screw reverse gap and servo motor parameters are checked;

[0015] S4, surface strengthening treatment of qualified products: surface shot blasting treatment is performed on the head area of the first and second lips and the adjacent runner surface, and a residual compressive stress layer is formed on the surface of the area;

[0016] S5, performance detection of qualified products: the qualified double-lip volute is installed on a centrifugal pump to perform hydraulic performance test, pressure fluctuation test and vibration noise test, and the products meeting the performance indicators are determined as performance verification qualified products and are allowed to be shipped, otherwise, they are determined as unqualified products.

[0017] The application further provides that: the S3 step further comprises a cooling device, the cooling device comprises an adjustable spray gun and a temperature detector arranged on one side of the main shaft, when the temperature of the main shaft rises, it will also cause the reference to deviate, affecting the deviation of C1 and C2, and the specific operation method comprises the following steps:

[0018] In S3, when C1 and C2 increase or decrease synchronously, first check whether the temperature of the main shaft is too high, set the real-time collected temperature as T, the set value temperature as t, and the temperature deviation value as ΔT=T-t;

[0019] When |ΔT|≤ΔT1 (small threshold value), the controller maintains the basic flow of the current cooling liquid, the spray gun uniformly cools the main shaft, and the tool wear is detected;

[0020] When |DeltaT|>DeltaT1, it indicates that the main shaft temperature rising trend is obvious, the controller starts the temperature control compensation program, the total flow of the cooling liquid is increased according to the preset algorithm, the specific angle of the spray gun is instructed to enhance the directional injection to the identified high temperature point, and the products after processing are detected for three times in succession, if the products are qualified, the machine continues to run, otherwise, if the products are unqualified, the machine is suspended for cooling inspection.

[0021] The application is further provided with: the shot blasting device for shot blasting in the S4 step is provided with a shot breaking rate detection device, the shot breaking rate detection device comprises an automatic sampler arranged on one side of a shot entering channel, a visual detection unit for observing the outer surface of the shot, and an actuator, the automatic sampler can collect a small amount of shot samples in use at a set frequency or time interval, the shot blasting device is provided with a shot blasting gun for real-time detection of residual stress, and the specific operation method comprises the following steps:

[0022] A residual stress range sigma1-sigma2 is set, and the real-time detected residual stress is F;

[0023] When sigma1<F<sigma2, the equipment is in normal operation;

[0024] When sigma2<=F or F>k*sigma2 (wherein k is a pre-warning coefficient less than 1), a control instruction is immediately generated to drive the shot blasting gun to increase the distance from the workpiece surface and reduce the shot blasting flow;

[0025] When F<sigma1, the shot blasting gun is controlled to reduce the distance from the workpiece surface and increase the shot blasting flow, and when the F value does not obviously rise after a t time period, the shot is collected for breaking rate detection:

[0026] A breaking rate value R is set, and the particle size part of the current shot is counted;

[0027] When R<B1, and the particle size distribution is within the qualified range, it is determined that the shot state is healthy, and the shot blasting gun parameters are continuously adjusted;

[0028] When B1<R<B2, it is determined that the shot state is degraded, the system sends a pre-warning to the operator that the shot performance is degraded and the shot needs to be replaced;

[0029] When R>B2, it is determined that the shot state is unqualified, and the equipment is immediately stopped for operation, and the shot is replaced.

[0030] A double splitter tongue volute manufactured by the method of claim 1-3 for centrifugal pump, comprising a volute body with a spiral flow channel inside, two first and second splitter tongues radially extending near the outlet diffuser section of the volute body, the first and second splitter tongues arranged in front and back along the spiral direction of the flow channel and separating the inlet of the outlet diffuser section into at least two flow channel areas, the double splitter tongue structure formed by the first and second splitter tongues configured to suppress the wake and jet effects at the impeller outlet, reduce the generation of vortex and secondary flow in the volute, and thus optimize the flow state of the internal flow field.

[0031] The application is further provided that: the first splitter tongue is located near the impeller side, and the radial gap between the first splitter tongue and the outer edge of the impeller is C1, the second splitter tongue is located downstream of the first splitter tongue, and the radial gap between the second splitter tongue and the outer edge of the impeller is C2, wherein C1 < C2.

[0032] The application is further provided that: the ratio of the radial gaps C1 and C2 ranges from 2 / 5 to 5 / 6.

[0033] The application is further provided that: the tongue angles of the first and second splitter tongues are not the same, and the tongue angle is the included angle between the working surface of the splitter tongue and the direction of the absolute velocity of the fluid at the outlet of the impeller.

[0034] The application is further provided that: the head of the first and second splitter tongues is in a round or elliptical structure.

[0035] The application is further provided that: the outlet diffuser section is a tapered pipe or a rectangular pipe with gradually increasing cross-sectional area in the fluid direction.

[0036] The application has the following beneficial effects:

[0037] 1. Through the cooperation of multiple links such as integrated blank preparation, precision quality detection and finishing, splitter tongue gap real-time monitoring and adjustment, surface strengthening treatment, and overall performance testing, the quality consistency and reliability of the product are significantly improved. The integrated forming of investment casting, combined with industrial CT scanning and micro-arc welding repair, effectively controls the porosity and wall thickness, reduces internal defects, and ensures the structural integrity and dimensional stability of the volute. The splitter tongue gap is monitored in real time by the in-machine laser probe, and the equipment parameters are automatically adjusted based on data feedback to avoid batch deviations, improve production efficiency and product qualification rate. The key areas of the splitter tongue are subjected to shot peening treatment to form a residual compressive stress layer, significantly improving the fatigue resistance and cavitation erosion resistance, and prolonging the service life of the volute. The final hydraulic performance, pressure pulsation and vibration noise test ensures that the product meets the strict operating condition requirements, reduces the energy consumption and noise of the pump during operation, and improves the overall system efficiency.

[0038] 2. In step S3, the spindle temperature is monitored and compensated in real time as a key variable affecting the gap between the shrouds. By actively suppressing the reference offset caused by the thermal elongation of the spindle through the intelligent cooling device, the error source is intervened, making the control of the C1 and C2 gaps more stable and accurate, and significantly reducing the risk of batch quality fluctuations caused by environmental temperature rise. In step S4, the real-time detection results of residual stress are dynamically linked with the shot blasting process parameters (distance, flow), realizing quantitative spraying of strengthening effect. At the same time, the innovative projectile fragmentation rate detection mechanism can accurately diagnose the performance degradation of the projectile, and timely alarm or stop to replace the projectile, which fundamentally avoids the problem of uneven or insufficient strengthening layer quality caused by medium failure, and ensures the uniformity and consistency of the surface residual compressive stress layer of each product.

[0039] 3. The double-shroud structure arranged in front and back and having a specific gap ratio (C1 / C2) can guide the fluid discharged from the impeller in stages and smoothly. It effectively suppresses the strong wake-jet interference effect under the single-shroud structure, significantly reduces the flow loss and impact loss in the volute, thereby widening the high-efficiency area of the pump and improving the overall operating efficiency. The double-shroud structure decomposes the dynamic-static interference between the impeller and the shroud into two positions, destroying the single and strong pressure pulsation source, making the pressure field inside the volute more uniform and stable. This feature can greatly reduce the pressure pulsation amplitude during the operation of the centrifugal pump, thereby reducing vibration and fluid noise, and improving the running stability and quietness of the pump set.

[0040] 4. By setting two shrouds with C1 BRIEF DESCRIPTION OF DRAWINGS

[0041] Fig. 1 is a flow chart of an embodiment of a manufacturing method for a double-shroud volute for a centrifugal pump of the present application.

[0042] Fig. 2 Flow chart of the cooling device of the present application;

[0043] Fig. 3 Flow chart of residual stress detection and projectile breakage rate detection;

[0044] Fig. 4 Schematic diagram of the three-dimensional structure of the double-tongue volute;

[0045] Fig. 5 Partial enlarged view of the double-tongue volute;

[0046] Figs. 1-5 Reference signs: 1, volute body; 2, first tongue; 3, second tongue; 4, outlet diffuser section. DETAILED DESCRIPTION

[0047] Reference Figs. 1-5 Further description of the embodiments of the present application.

[0048] For ease of description, spatial relative terms such as "upper", "lower", "left", "right" and the like are used in the embodiments to describe the relationship of one element or feature to another element or feature shown in the drawings. It should be understood that, in addition to the orientation shown in the drawings, the spatial terms are intended to include different orientations of the device in use or operation. For example, if the device in the drawings is inverted, the element described as being "below" other elements or features will be positioned "above" the other elements or features. Therefore, the exemplary term "below" can include both upward and downward orientations. The device can be positioned in other ways (rotated 90 degrees or positioned in other orientations), and the spatial relative descriptions used herein can be interpreted accordingly.

[0049] Moreover, relational terms such as "first" and "second" and the like are used only to distinguish one component from another component having the same name, and do not necessarily require or imply any such actual relationship or order between the components.

[0050] Figs. 1 to 5 A manufacturing method of a double-tongue volute for a centrifugal pump is shown, comprising the following steps:

[0051] S1, preparation of an integrated blank: using investment casting technology, an integrated blank of the volute containing the preliminary structure of the first tongue 2 and the second tongue 3 is prepared, so that the radial gap C1 of the first tongue 2 to the impeller is less than the radial gap C2 of the second tongue 3 to the impeller;

[0052] S2, preliminary quality detection and finishing: the volute blank is scanned using industrial CT, the porosity in the CT scan image is calculated, and the wall thickness at key positions of the flow channel is measured, and the integrated blank that passes the detection is subjected to finishing and polishing treatment:

[0053] When the porosity is lower than the first threshold A and the wall thickness is within the design tolerance range, it is determined that the blank is qualified, and flows into the finishing process;

[0054] When the porosity is between the threshold A and a higher threshold B, it is determined that the product is repairable, and the defect area is repaired by micro-arc welding process, and CT scanning is performed again, and the same determination logic is executed to ensure that the defect has been eliminated to the qualified level;

[0055] When the porosity is higher than the threshold B or the wall thickness is seriously out of tolerance, it is determined that the product is a waste product;

[0056] S3, the gap between the spacers is detected: after the one-piece blank is milled, the head key point coordinates of the first spacer 2 and the second spacer 3 are measured in real time using the in-machine laser probe. Based on the measured point coordinates, the actual radial gaps C1 and C2 are calculated according to the three-dimensional digital model, and the ratio C1 / C2 is calculated:

[0057] When C1 is less than C2, and the value of C1 / C2 is between 2 / 5-5 / 6, it is determined to be qualified;

[0058] When C1 is greater than C2 or the value of C1 / C2 is not within the range of 2 / 5-5 / 6, it is determined to be repaired, and if three unqualified products appear continuously within T time, the recorded parameters are read, and the equipment parameters need to be adjusted:

[0059] When C1 and C2 increase or decrease synchronously, check the wear of the tool, and adjust the tool length and radius compensation parameter to reduce;

[0060] When the ratio of C1 / C2 continuously deviates and the direction is consistent, check the screw reverse gap and servo motor parameters;

[0061] S4, surface strengthening treatment of qualified products: surface shot blasting treatment is performed on the head area of the first spacer 2 and the second spacer 3 and the adjacent runner surface, and a residual compressive stress layer is formed on the surface of the area;

[0062] S5, performance detection of qualified products: install the qualified double-spacer volute into the centrifugal pump, and perform hydraulic performance test, pressure fluctuation test and vibration noise test. If all the above tests meet the performance indicators, the volute is determined to be a performance verified qualified product, which is allowed to be shipped, otherwise, it is determined to be an unqualified product.

[0063] Through the integration of blank preparation, precision quality detection and finishing, real-time monitoring and adjustment of the tongue gap, surface strengthening treatment, and comprehensive performance testing, the product quality consistency and reliability are significantly improved. The integrated forming of precision investment casting, combined with industrial CT scanning and micro-arc welding repair, effectively controls porosity and wall thickness, reduces internal defects, and ensures the integrity and dimensional stability of the volute structure. The tongue gap is monitored in real time by the in-machine laser measuring head, and the equipment parameters are automatically adjusted based on data feedback to avoid batch deviations, improve production efficiency and product qualification rate. The key areas of the tongue are shot peened to form a residual compressive stress layer, significantly improving fatigue resistance and cavitation erosion resistance, and extending the service life of the volute. The final hydraulic performance, pressure pulsation and vibration noise tests ensure that the product meets the strict operating condition requirements, reduces the energy consumption and noise of the pump during operation, and improves the overall system efficiency.

[0064] The S3 step also has a cooling device, which includes an adjustable spray gun and a temperature detector arranged on one side of the main shaft. When the temperature of the main shaft rises, it will also cause the reference to deviate, affecting the deviation of C1 and C2. The specific operation method includes the following steps:

[0065] In S3, C1 and C2 are increased or decreased synchronously. First, check whether the temperature of the main shaft is too high. Set the real-time collected temperature as T, the set value temperature as t, and the temperature deviation value ΔT = T-t.

[0066] When |ΔT|≤ΔT1 (small threshold), the controller maintains the current basic flow of the cooling liquid, and the spray gun uniformly cools the main shaft. Then, detect the tool wear condition.

[0067] When |ΔT|>ΔT1, it indicates that the main shaft temperature is rising significantly. The controller starts the temperature control compensation program, increases the total flow of the cooling liquid according to the preset algorithm, and can instruct the spray gun at a specific angle to enhance the directional injection of the identified high temperature point. Adjust the processed products for detection for three consecutive times. If the products are qualified, the machine continues to run. Otherwise, if the products are unqualified, the machine is paused for cooling inspection.

[0068] In the S3 step, the temperature of the main shaft is monitored and compensated as a key variable affecting the tongue gap. Through the intelligent cooling device, the reference deviation caused by the thermal elongation of the main shaft is actively suppressed, and the error source is intervened, making the control of the gap between C1 and C2 more stable and accurate, and significantly reducing the risk of batch quality fluctuations caused by environmental temperature rise.

[0069] The shot blasting device for shot blasting in the S4 step is provided with a shot breaking rate detection device, the shot breaking rate detection device comprises an automatic sampler arranged on one side of a shot entering channel, a visual detection unit for observing the outer surface of the shot, and an actuator, the automatic sampler can collect a small amount of shot sample being used at a set frequency or time interval, the shot blasting device is provided with a shot blasting gun for real-time detection of residual stress, and the specific operation method comprises the following steps:

[0070] A residual stress range σ1-σ2 is set, and the real-time detected residual stress is F;

[0071] When σ1<F<σ2, the equipment is in normal operation;

[0072] When σ2≤F or F>k*σ2 (where k is a pre-warning coefficient less than 1), a control instruction is immediately generated to drive the shot blasting gun to increase the distance from the workpiece surface and reduce the shot blasting flow;

[0073] When F<σ1, the shot blasting gun is controlled to reduce the distance from the workpiece surface and increase the shot blasting flow, and after a period of t, if the F value does not rise obviously, the shot is collected for breaking rate detection:

[0074] A breaking rate value R is set, and the particle size part of the current shot is counted;

[0075] When R<B1, and the particle size distribution is within the qualified range, it is determined that the shot state is healthy, and the shot blasting gun parameters are continued to be adjusted;

[0076] When B1<R<B2, it is determined that the shot state is degraded, and the system sends a pre-warning to the operator that the shot performance is degraded and suggests to prepare for replacement;

[0077] When R>B2, it is determined that the shot state is unqualified, and the equipment operation is immediately stopped, and the shot is replaced.

[0078] In the S4 step, the real-time detection result of the residual stress is dynamically linked with the shot blasting process parameters (distance, flow), and quantitative spraying of the strengthening effect is realized. Meanwhile, the innovative shot breaking rate detection mechanism can accurately diagnose the shot performance degradation condition, timely pre-warning or shutdown and replacement of the shot, and fundamentally avoids the problem of uneven or insufficient strengthening layer quality caused by medium failure, and ensures the uniformity and consistency of the residual compressive stress layer on the surface of each product.

[0079] A double splitter volute manufactured according to the method for manufacturing a double splitter volute for a centrifugal pump, comprising a volute body 1 with a spiral flow channel inside, two first and second splitter vanes 2 and 3 radially extending near the outlet diffuser section 4 of the volute body 1, the first and second splitter vanes 2 and 3 being arranged in front of and behind the spiral direction of the flow channel and separating the inlet of the outlet diffuser section 4 into at least two flow channel areas, the double splitter structure formed by the first and second splitter vanes 2 and 3 is configured to suppress the wake and jet effects at the outlet of the impeller, reduce the generation of vortex and secondary flow in the volute, and thus optimize the flow state of the internal flow field. The double splitter structure arranged in front of and behind and having a specific gap ratio (C1 / C2) can guide the fluid discharged from the impeller in stages and smoothly. It effectively suppresses the strong wake-jet interference effect under the single splitter structure, significantly reduces the flow loss and impact loss in the volute, thereby widening the high efficiency area of the pump and improving the overall operation efficiency. The double splitter structure decomposes the dynamic-static interference between the impeller and the splitter into two positions, destroys the single and strong pressure pulsation source, and makes the pressure field inside the volute more uniform and stable. This feature can greatly reduce the pressure pulsation amplitude during the operation of the centrifugal pump, thereby reducing vibration and fluid noise and improving the operation stability and quietness of the pump set.

[0080] The first splitter vane 2 is located near the impeller side, and the radial gap between it and the outer edge of the impeller is C1, and the second splitter vane 3 is located downstream of the first splitter vane 2, and the radial gap between it and the outer edge of the impeller is C2, wherein C1

[0081] When the ratio of the radial clearances C1 and C2 is less than 2 / 5, the fluid at the impeller outlet is excessively blocked when encountering the first partition tongue 2, resulting in a larger local resistance, and when the fluid passes near the first partition tongue 2, strong turbulence and vortexes are formed, increasing energy loss; when the ratio of the radial clearances C1 and C2 is greater than 5 / 6, the wake and jet phenomena cannot be effectively controlled, which can cause the flow field in the volute to be turbulent, and the high-speed jet can directly impact on the second partition tongue 3, forming strong vortexes and secondary flow near the second partition tongue 3, which destroys the ordered regulation of the double partition tongue structure to the fluid, so that the internal flow field cannot reach an optimized state; therefore, the ratio of the radial clearances C1 and C2 is preferably in the range of 2 / 5 to 5 / 6, which can more effectively suppress the wake-jet effect at the impeller outlet, greatly weaken the vortexes and secondary flow in the volute, thereby reducing the hydraulic loss and improving the operating efficiency of the centrifugal pump.

[0082] The tongue angles of the first partition tongue 2 and the second partition tongue 3 are different, and the tongue angle is the included angle between the partition tongue working surface and the absolute velocity direction of the fluid at the impeller outlet, which can make the working surface of each partition tongue more accurately match the absolute velocity direction of the fluid at the position, and minimize the impact of the fluid on the head of the partition tongue, not only further reducing the impact loss and noise, but also relieving the load of the partition tongue, which is helpful to improve the reliability of long-term work.

[0083] The head of the first partition tongue 2 and the second partition tongue 3 is in a rounded or elliptical structure, which can effectively avoid the stress concentration phenomenon caused by sharp corners, greatly improving the fatigue resistance and anti-cavitation damage of the partition tongue head, thereby prolonging the service life of the volute under harsh working conditions.

[0084] The outlet diffuser section 4 is a tapered pipe or a rectangular pipe with gradually increasing cross-sectional area along the fluid direction, which can efficiently convert the kinetic energy of the fluid into pressure energy, improve the lift of the pump, and combine the optimization of the flow field by the double partition tongue, so that the volute can maintain good performance stability under various flow conditions, and the efficient operation range of the centrifugal pump is widened.

[0085] The above only describes the preferred embodiments of the present application, and is not intended to limit the present application, and those skilled in the art can make usual changes and replacements within the technical scheme of the present application, which should be included in the protection scope of the present application.

Claims

1. A method for manufacturing a double-tongue volute for a centrifugal pump, characterized in that, Includes the following steps: S1. Preparation of integrated blank: Using investment casting technology, an integrated blank of the volute containing the preliminary structure of the first tongue (2) and the second tongue (3) is prepared, so that the radial clearance C1 between the first tongue (2) and the impeller is less than the radial clearance C2 between the second tongue (3) and the impeller. S2. Preliminary quality inspection and finishing: The volute blank is scanned using an industrial CT scanner. The porosity in the CT scan image is calculated, and the wall thickness at key locations in the flow channel is measured. The integrated blank that passes the inspection is then finished and polished. When the porosity is lower than the first threshold A and the wall thickness is within the design tolerance range, it is judged as a qualified blank and flows into the finishing process; When the porosity is between threshold A and a higher threshold B, it is determined to be a repairable product. The defective area is repaired using micro-arc welding technology, and a CT scan is performed again, and the same judgment logic is executed to ensure that the defect has been eliminated to the qualified level. If the porosity is higher than the threshold B or the wall thickness is seriously out of tolerance, it is judged as a defective product. S3. Tongue Gap Detection: After milling the surface of the integrally formed blank, the coordinates of the key points at the head of the first tongue (2) and the second tongue (3) are measured in real time using an in-machine laser probe. Based on the coordinates of the measuring points, the actual radial gaps C1 and C2 are calculated according to the three-dimensional digital model, and their ratio C1 / C2 is calculated: If C1 < C2, and the value of C1 / C2 is between 2 / 5 and 5 / 6, then it is considered qualified. If C1 > C2 or the value of C1 / C2 is not within the range of 2 / 5-5 / 6, it is determined that rework is required. If three consecutive defective products appear within time T, the recorded parameters should be read and the equipment parameters should be readjusted. When C1 and C2 increase or decrease simultaneously, check the tool wear and adjust the tool length and radius compensation parameters to a smaller value. If the ratio of C1 / C2 continues to deviate but in the same direction, check the lead screw backlash and servo motor parameters. S4. Surface strengthening treatment of qualified products: The head area of ​​the first tongue (2) and the second tongue (3) and the adjacent flow channel surface are subjected to surface shot peening treatment to form a residual compressive stress layer on the surface of the area. S5. Performance testing of qualified products: Install the qualified double-tongue volute onto the centrifugal pump and conduct hydraulic performance tests, pressure pulsation tests, and vibration and noise tests. If the product meets the performance indicators in all the above tests, the volute is judged to be a qualified product and is allowed to leave the factory; otherwise, it is judged to be an unqualified product.

2. The method for manufacturing a double-tongue volute for a centrifugal pump according to claim 1, characterized in that, The S3 step also includes a cooling device, which comprises an adjustable spray gun and a temperature detector located on one side of the spindle. When the spindle temperature rises, it will also cause a reference offset, affecting the deviation of C1 and C2. The specific operation method includes the following steps: In S3, C1 and C2 increase or decrease synchronously. First, check if the spindle temperature is too high. Set the real-time temperature to T, the set value temperature to t, and the temperature deviation value ΔT = Tt. When |ΔT|≤ΔT1 (small threshold), the controller maintains the current basic flow rate of coolant, the spray gun provides uniform cooling to the spindle, and the tool wear is detected. When |ΔT|>ΔT1, it indicates that the spindle is heating up significantly. The controller starts the temperature control compensation program, increases the total flow of coolant according to the preset algorithm, and can instruct the spray gun at a specific angle to enhance the directional spraying of the identified high-temperature points. The controller then adjusts the process to perform three consecutive tests on the processed products. If the products are qualified, the machine continues to run; otherwise, if the products are unqualified, the machine is paused for cooling checks.

3. A method for manufacturing a double-tongue volute for a centrifugal pump according to claim 1, characterized in that, In step S4, the shot peening device is equipped with a shot breakage rate detection device at its loading port. This device includes an automatic sampler located on one side of the shot entry channel, a visual inspection unit for observing the outer surface of the shot, and an actuator. The automatic sampler can collect a small number of currently used shot samples at a set frequency or time interval. The shot peening device is equipped with a shot peening gun for real-time residual stress detection. The specific operation method includes the following steps: Set the residual stress range σ1-σ2, and detect the residual stress as F in real time; When σ1 < F < σ2, the equipment operates normally; When σ2≤F or F>k*σ2 (where k is a warning coefficient less than 1), a control command is immediately generated to drive the shot peening gun to increase the distance between itself and the workpiece surface and to reduce the shot peening flow rate. When F < σ1, the distance between the shot peening gun and the workpiece surface is reduced and the shot peening flow rate is increased. After time interval t, if the value of F does not increase significantly, the shot is collected for breakage rate detection. Set the breakage rate value to R, and calculate the particle size distribution of the current projectile; When R < preset threshold B1 and the particle size distribution is within the acceptable range, the shot is determined to be in good condition, and the shot peening gun parameters are adjusted further. When the preset threshold B1 < R < preset threshold B2, the projectile is determined to be in a state of degradation, and the system issues a warning to the operator that the projectile performance has deteriorated and suggests preparing for replacement. When R > preset threshold B2, the projectile is determined to be in an unqualified state, the equipment is immediately stopped, and the projectile is replaced.

4. The double-tongue volute for centrifugal pumps manufactured by the method described in claims 1-3, comprising a volute body (1) having an internal helical flow channel, characterized in that, Near the outlet diffuser section (4) of the volute body (1), there are two radially extending first and second baffles (3). The first baffle (2) and the second baffle (3) are arranged back and forth along the spiral direction of the flow channel and divide the inlet of the outlet diffuser section (4) into at least two flow channel regions. The double baffle structure formed by the first baffle and the second baffle (3) is configured to suppress the wake and jet effect of the impeller outlet, reduce the generation of vortices and secondary flows in the volute, and thus optimize the internal flow field state.

5. A double-tongue volute for a centrifugal pump according to claim 4, characterized in that, The first tongue (2) is located near the impeller, and the radial gap between it and the outer edge of the impeller is C1. The second tongue (3) is located downstream of the first tongue (2), and the radial gap between it and the outer edge of the impeller is C2, wherein C1 < C2.

6. A double-tongue volute for a centrifugal pump according to claim 4, characterized in that, The ratio of the radial clearance C1 to C2 ranges from 2 / 5 to 5 / 6.

7. A double-tongue volute for a centrifugal pump according to claim 4, characterized in that, The tongue angles of the first tongue (2) and the second tongue (3) are different. The tongue angle is the angle between the working surface of the tongue and the direction of the absolute velocity of the fluid at the impeller outlet.

8. A double-tongue volute for a centrifugal pump according to claim 4, characterized in that, The head shape of the first tongue (2) and the second tongue (3) is rounded or elliptical.

9. A double-tongue volute for a centrifugal pump according to claim 4, characterized in that, The outlet diffusion section (4) is a tapered or rectangular tube with a cross-sectional area that gradually increases along the fluid direction.

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