Structure and method for detecting sealing performance of low-pressure cavity of Kapram rotating wheel

Abstract

The invention discloses a Kapram runner low-pressure cavity sealing performance detection structure and method. The Kapram runner low-pressure cavity sealing performance detection structure comprises a center shaft, a lateral rotating shaft, a high-pressure cavity, a low-pressure cavity, blades and blade seals. The high-pressure cavity is arranged around the center shaft, part of the low-pressure cavity is arranged around the lateral rotating shaft, the blades are arranged on the lateral rotating shaft, and blade seals are arranged around the circumferential positions of the blades. A process sealing structure is arranged on a connecting passage of the blade seal and the low-pressure cavity; a pressing hole connected with the outside is formed between the process sealing structure and the blade seal; according to the scheme, the pressure cavity overall sealing performance detection test is changed from an oil-tight test to an air-tight test, the cost is lower, and the leakage detection effect is better.

Description

Technical Field

[0001] The invention belongs to the field of rotor sealing performance detection, and in particular relates to a structure and method for detecting the sealing performance of a Kaplan rotor low-pressure cavity. Background Art

[0002] The assembly parts of the Kaplan unit runner must be assembled as a whole and undergo movement and sealing tests in the factory to check the rationality of the design and the accuracy of manufacturing. This is a necessary step in the unit manufacturing process.

[0003] According to the existing organization method, when the runner assembly is undergoing action and sealing tests, the cavity is filled with test oil. Figure 1 As shown in the figure, the test oil in the high-pressure chamber is used to test the flexibility of the transmission mechanism and the reliability of the seal, and is essential oil. The test oil in the low-pressure chamber is only used to test the sealing performance of the components in the chamber and is not essential oil. Using oil quality to test sealing performance is reliable and accurate, but it also has the following two problems:

[0004] 1. High cost

[0005] like Figure 1 As shown in the figure, during the Kaplan wheel test, both the high-pressure and low-pressure chambers are filled with test oil, with the high-pressure chamber requiring 1,100 liters and the low-pressure chamber requiring 6,700 liters. Due to oil quality requirements and safety concerns, this oil cannot be reused. Therefore, the cost of test oil for the low-pressure chamber of a single wheel assembly is as high as 96,000 yuan.

[0006] 2. Long cycle

[0007] Due to the large amount of oil used in the test, the oil filling and draining cycle of the low-pressure chamber of a single runner assembly is as long as 35 hours (3 days), which is a long cycle. Summary of the Invention

[0008] The purpose of the present invention is to provide a Kaplan runner low-pressure chamber sealing performance detection structure and method to address the above-mentioned shortcomings, thereby solving the problems of long experimental cycle and high cost in the prior art when performing sealing tests on Kaplan unit runners.

[0009] The present invention is achieved through the following solutions:

[0010] A Kaplan runner low-pressure chamber sealing performance detection structure includes a central axis, a lateral rotating shaft, a high-pressure chamber, a low-pressure chamber, blades and blade seals; the high-pressure chamber is arranged around the central axis, part of the low-pressure chamber is arranged around the lateral rotating shaft, the blades and blade flanges are a whole, and blade seals are arranged at circumferential positions around the blade flanges; a process sealing structure is provided on the connecting passage between the blade seal and the low-pressure chamber; a punching hole connected to the outside world is provided between the process sealing structure and the blade seal.

[0011] Based on the above-mentioned Kaplan runner low-pressure chamber sealing performance detection structure, the process sealing structure specifically includes a fixed connecting groove arranged on the blade seal and low-pressure chamber connecting passage and a seal arranged in the connecting groove; the blade seal and the low-pressure chamber are blocked by the seal and the sealing groove.

[0012] Based on the above-mentioned Kaplan wheel low-pressure chamber sealing performance detection structure, the punching hole is an L-shaped structure as a whole, the outlet end of the punching hole is arranged between the blade seal and the process sealing structure, and the inlet end of the punching hole is connected to the outside world.

[0013] Based on the above-mentioned Kaplan runner low-pressure chamber sealing performance detection structure, the punching holes are arranged in a plurality along the circumference of the runner, and each punching hole is arranged on the blade flange.

[0014] Based on the above-mentioned Kaplan runner low-pressure chamber sealing performance detection structure, a pressure ring is further provided between the blade seal and the runner side.

[0015] This solution also provides a method for testing the sealing performance of the low-pressure chamber of a Kaplan runner, comprising the following steps:

[0016] Step S1, low-pressure chamber airtightness test: using compressed gas to perform an airtightness test on the low-pressure chamber alone;

[0017] Step S2, blade seal oil leakage test: perform a blade seal oil leakage test on the blade seal separately through the L-shaped punching hole.

[0018] In step S1, the low-pressure chamber airtightness test may specifically include the following steps:

[0019] Step S11, pre-assembling the various components of the runner into a whole;

[0020] Step S12, brushing bubble water on each sealing surface of the low-pressure chamber;

[0021] Step S13, injecting pressurized air into the low-pressure chamber through the pressure hole of the rotor body;

[0022] Step S14, checking the air pump pressure maintenance and surface leakage of each component;

[0023] Step S15: If there is no leakage, the pressure is qualified; if there is a leakage, the leakage point is treated and the pressure is re-applied.

[0024] In step S2, the blade seal oil leakage test specifically includes the following steps:

[0025] Step S21: After the low-pressure chamber airtightness test is passed, the air pressure in the low-pressure chamber is released;

[0026] Step S22: Inject oil into each blade seal cavity through the L-shaped pressure hole, maintain pressure according to design requirements, and check the blade seal oil leakage and oil pump pressure maintenance;

[0027] Step S23: Rotate the blades according to the design requirements, and check the oil pump pressure maintenance and blade seal oil leakage;

[0028] Step S24: maintain pressure after rotation, and check the oil pump pressure maintenance and oil leakage;

[0029] Step S25: After passing the test, the punching hole is sealed.

[0030] Applicable to Kaplan impellers with vane seals.

[0031] In summary, due to the adoption of the above technical solution, the beneficial effects of the present invention are:

[0032] 1. Low cost: Taking a Kaplan runner within the plant as an example, the cost of oil used for testing a single runner was reduced from 116,000 yuan to 19,000 yuan, saving 97,000 yuan per unit. Based on an annual production of 10 Kaplan runners, this translates to a cost savings of 970,000 yuan in a single year.

[0033] 2. High efficiency: The overall oil tightness test of the low-pressure chamber is optimized to an air tightness test, and the oil filling and draining cycle is shortened from 3 days to 0.5 days, greatly improving efficiency.

[0034] 3. Good safety: less oil is used in the test, oil management is easier, and safety hazards are greatly reduced.

[0035] 4. High quality: Since gas molecules are smaller than oil molecules, the inspection requirements for air tightness tests are stricter and the quality of sealing performance inspection is higher. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 It is a schematic diagram of the overall structure of the prior art;

[0037] Figure 2 It is a cross-sectional view of the overall structure of the present invention;

[0038] Figure 3 yes Figure 2 A schematic diagram of the enlarged structure at point A (schematic diagram of the L-shaped punching hole and process sealing structure);

[0039] Figure 4 It is a schematic diagram of a partially enlarged structure in the prior art;

[0040] Figure numerals: 1. Central axis; 2. Lateral rotating shaft; 3. High-pressure chamber; 4. Low-pressure chamber; 5. Blade; 6. Blade seal; 7. Process sealing structure; 8. Pressing hole; 9. Pressure ring; 10. Blade flange. DETAILED DESCRIPTION

[0041] All features disclosed in this specification, or all steps in the disclosed methods or processes, except mutually exclusive features and / or steps, can be combined in any manner.

[0042] Any feature disclosed in this specification (including any appended claims and abstract), unless otherwise stated, may be replaced by other equivalent or similar features. That is, unless otherwise stated, each feature is only an example of a series of equivalent or similar features.

[0043] In the description of the present invention, it should be understood that the terms "up", "down", "left", "right", etc., indicating directions or positional relationships, are based on the directions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a predetermined direction, be constructed and operated in a predetermined direction, and therefore cannot be understood as a limitation on the present invention.

[0044] Furthermore, the terms "first," "second," etc., are used for descriptive purposes only and should not be understood to indicate or imply relative importance or to implicitly indicate the quantity of the technical features being referred to. Thus, a feature defined as "first," "second," etc. may explicitly or implicitly include one or more of such features.

[0045] Example 1

[0046] like Figures 2 and 3 As shown, the present invention provides a technical solution:

[0047] A Kaplan runner low-pressure chamber 4 sealing performance detection structure includes at least but not limited to a central axis 1, a lateral rotating shaft 2, a high-pressure chamber 3, a low-pressure chamber 4, blades 5 and blade seals 6; the high-pressure chamber 3 is arranged around the central axis 1, part of the cavity of the low-pressure chamber 4 is arranged around the lateral rotating shaft 2, the blades 5 are arranged on the lateral rotating shaft 2, and blade seals 6 are arranged at circumferential positions around the blades 5; a process sealing structure 7 is provided on the connecting passage between the blade seal 6 and the low-pressure chamber 4; a punching hole 8 connected to the outside world is provided between the process sealing structure 7 and the blade seal 6.

[0048] Based on the above structure, in the traditional structure, since the blade seal 6 is usually directly connected to the low-pressure chamber 4, when the low-pressure chamber 4 is subjected to a sealing test, the blade seal 6 will also be tested simultaneously. However, when the low-pressure chamber 4 is sealed, about 6700L of oil will be used, and the oil cannot be reused. Therefore, this structure is provided with a process sealing structure 7 on the connecting passage between the low-pressure chamber 4 and the blade seal 6 to block the low-pressure chamber 4 and the blade seal 6, and at the same time, a punching hole 8 is provided with the blade seal 6, which can independently perform experimental testing on the blade seal 6, and at the same time, gas is used to test the low-pressure chamber 4, which can greatly reduce the overall testing cost and testing time.

[0049] As an example, the process sealing structure 7 may specifically include a fixed connecting groove arranged on the connecting passage between the blade seal 6 and the low-pressure chamber 4 and a seal arranged in the connecting groove; the blade seal 6 and the low-pressure chamber 4 are blocked by the seal and the sealing groove, and a seal is arranged on the connecting passage, which can achieve isolation simply and efficiently, so that a sealed cavity is formed between the blade seal 6 and the low-pressure chamber 4 of the impeller body, providing a prerequisite for the blade seal 6 to be pressed separately.

[0050] As an example, the punching hole 8 is an L-shaped structure as a whole, the air outlet end of the punching hole 8 is arranged between the blade seal 6 and the process sealing structure 7, and the air inlet end of the punching hole 8 is connected to the outside world;

[0051] Based on the above structure, this solution can directly test the blade seal 6 when the blade seal 6 and the low-pressure chamber 4 are blocked by the specially arranged L-shaped pressure hole 8, and can perform the test at low cost and high efficiency.

[0052] As an example, a plurality of punching holes 8 are provided along the circumference of the runner, and each punching hole 8 is provided near the blade 5 .

[0053] As an example, a pressure ring 9 is also provided between the blade seal 6 and the side of the runner;

[0054] A blade flange 10 is provided between the blade seal 6 and the L-shaped punching hole 8;

[0055] Based on the above structure, multiple blades 5 can be tested simultaneously through multiple punching holes 8, which can further improve the testing efficiency.

[0056] Example 2

[0057] Based on the above embodiment 1, the present invention provides a technical solution:

[0058] A method for detecting the sealing performance of a low-pressure chamber 4 of a Kaplan runner comprises the following steps:

[0059] Step S1, airtightness test of the low-pressure chamber 4: using compressed gas to perform an airtightness test on the low-pressure chamber 4 alone;

[0060] Step S2 , performing an oil leakage test on the blade seal 6 ; performing an oil leakage test on the blade seal 6 through the L-shaped punching hole 8 .

[0061] In step S1, the airtightness test of the low-pressure chamber 4 may specifically include the following steps:

[0062] Step S11, pre-assembling the various components of the runner into a whole;

[0063] Step S12, brushing bubble water on each sealing surface of the low-pressure chamber 4;

[0064] Step S13, injecting pressurized air into the low-pressure chamber 4 through the pressure hole 8 of the rotor body;

[0065] Step S14, checking the air pump pressure maintenance and surface leakage of each component;

[0066] Step S15: If there is no leakage, the pressure is qualified; if there is leakage, the leak point is repaired and the pressure is re-tested;

[0067] Since the test oil in the traditional low-pressure chamber 4 is only used to detect the sealing performance of each component in the chamber and is non-essential oil, this solution replaces the anti-rust oil with compressed air. The sealing test is performed by injecting compressed gas. Each test can greatly reduce the cost and reduce at least 6700L of anti-rust oil. At the same time, the test time can also be greatly reduced each time. The injection and release time of anti-rust oil is usually 35 hours, while the injection of gas can be controlled within about 12 hours.

[0068] As an example, in step S2, the oil leakage test of the blade seal 6 specifically includes the following steps:

[0069] Step S21: After the low-pressure chamber 4 passes the airtightness test, the air pressure in the low-pressure chamber 4 is released;

[0070] Step S22: Inject oil into the cavity of each blade seal 6 through the L-shaped pressure hole 8, maintain pressure according to design requirements, and check the oil leakage of the blade seal 6 and the pressure maintenance of the oil pump;

[0071] Step S23, rotating the blade 5 according to the design requirements, and checking the oil pump pressure maintenance and the oil leakage of the blade seal 6;

[0072] Step S24: maintain pressure after rotation, and check the oil pump pressure maintenance and oil leakage;

[0073] Step S25: After passing the test, the punching hole 8 is sealed.

[0074] The airtightness test of the low-pressure chamber 4 can effectively detect the sealing performance of each component. However, due to the particularity of the blade seal 6, it is impossible to maintain pressure when the blade 5 rotates. In order to ensure the quality of product delivery, we conducted an oil leakage test on the blade seal 6 after the low-pressure chamber 4 airtightness test was passed. However, the test method is different from the traditional method, mainly reflected in the process structure and test process. Since the traditional structure cannot achieve independent pressure testing of the blade seal 6, we have made an innovative design for the structure of the blade seal 6.

[0075] This solution is applied to a Kaplan runner having a blade seal 6 structure.

[0076] This solution can bring the following benefits:

[0077] 1. The overall sealing performance test of low-pressure chamber 4 is changed from an oil-tight test to an air-tight test, which is more cost-effective and has a better leak detection effect.

[0078] 2. A process seal is arranged between the blade seal 6 and the low-pressure chamber 4 of the runner body to form a narrow sealed cavity.

[0079] 3. Carry out blade seal 6 oil leakage test under simulated working conditions, with short cycle and low oil consumption, while also ensuring product delivery quality.

[0080] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A Kaplan wheel low pressure chamber sealing performance detection structure, characterized in that: It includes a central axis, a lateral rotating shaft, a high-pressure chamber, a low-pressure chamber, blades and blade seals; the high-pressure chamber is arranged around the central axis, part of the low-pressure chamber is arranged around the lateral rotating shaft, the blades are arranged on the lateral rotating shaft, and blade seals are arranged around the circumferential position of the blades; a process sealing structure is provided on the connecting passage between the blade seal and the low-pressure chamber; a punching hole connected to the outside world is provided between the process sealing structure and the blade seal.

2. A Kaplan wheel low-pressure chamber sealing performance detection structure according to claim 1, characterized in that: The process sealing structure specifically includes a fixed connecting groove arranged on the connecting passage between the blade seal and the low-pressure chamber and a sealing member arranged in the connecting groove; the blade seal and the low-pressure chamber are blocked by the sealing member and the sealing groove.

3. The Kaplan wheel low-pressure chamber sealing performance detection structure according to claim 1, characterized in that: The punching hole is an L-shaped structure as a whole. The outlet end of the punching hole is arranged between the blade seal and the process seal structure, and the inlet end of the punching hole is connected to the outside.

4. The Kaplan wheel low-pressure chamber sealing performance detection structure according to claim 1, characterized in that: The punching holes are all arranged on the blade flange.

5. The Kaplan wheel low-pressure chamber sealing performance detection structure according to claim 1, characterized in that: A pressure ring is arranged on the outside of the blade seal, and its main function is to tighten the seal.

6. A method for detecting the sealing performance of the low-pressure chamber of a Kaplan wheel based on the detection structure for detecting the sealing performance of the Kaplan wheel according to any one of claims 1 to 5, characterized in that: The following steps are involved: Step S1, low-pressure chamber airtightness test: using compressed gas to perform an airtightness test on the low-pressure chamber alone; Step S2, blade seal oil leakage test: perform a blade seal oil leakage test on the blade seal separately through the L-shaped punching hole.

7. The method for detecting the sealing performance of the low-pressure chamber of a Kaplan wheel according to claim 1, characterized in that: In step S1, the low-pressure chamber airtightness test may specifically include the following steps: Step S11, pre-assembling the various components of the runner into a whole; Step S12, brushing bubble water on each sealing surface of the low-pressure chamber; Step S13, injecting pressurized air into the low-pressure chamber through the pressure hole of the rotor body; Step S14, checking the air pump pressure maintenance and surface leakage of each component; Step S15: If there is no leakage, the pressure is qualified; if there is a leakage, the leakage point is treated and the pressure is re-applied.

8. A method for detecting sealing performance of a Kaplan wheel low-pressure chamber according to claim 8, characterized in that: In step S2, the blade seal oil leakage test specifically includes the following steps: Step S21: After the low-pressure chamber airtightness test is passed, the air pressure in the low-pressure chamber is released; Step S22: Inject oil into each blade seal cavity through the L-shaped pressure hole, maintain pressure according to design requirements, and check the blade seal oil leakage and oil pump pressure maintenance; Step S23: Rotate the blades according to the design requirements, and check the oil pump pressure maintenance and blade seal oil leakage; Step S24: maintain pressure after rotation, and check the oil pump pressure maintenance and oil leakage; Step S25: After passing the test, the punching hole is sealed.

9. A method for detecting sealing performance of a Kaplan wheel low-pressure chamber according to claim 8, characterized in that: Applicable to Kaplan impellers with vane seals.

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