Water cut-off protection test system

Abstract

The utility model provides a water break protection test system, comprising a water tank used for storing cooling water; the input end of the pumping branch is communicated with the water tank, the output end of the pumping branch is communicated with the excitation end of the generator, and the pumping branch is used for pumping cooling water in the water tank and pumping the cooling water to the excitation end of the generator; the input end of the first water return branch is connected with the steam end of the generator, and the output end of the first water return branch is communicated with the water tank and used for guiding water output from the steam end of the generator into the water tank; and the second water return branch is provided with a throttling valve, the input end of the second water return branch is communicated with the output end of the pumping branch, and the output end of the second water return branch is communicated with the water tank. According to the utility model, through the arrangement of the second water return branch, the problem that the existing cooling water system cannot carry out a water break protection test is solved in the simplest and most convenient manner, the existing cooling water system can be directly transformed, and the transformation cost is low.

Description

Technical Field

[0001] This utility model relates to the field of generator water failure protection testing technology, and specifically to a water failure protection testing system. Background Technology

[0002] The statements herein provide only background information related to this invention and do not necessarily constitute prior art.

[0003] Currently, the conductors of dual water-cooled generators generate heat during operation and require cooling. The stator and rotor coils of the dual water-cooled generator are cooled with non-conductive demineralized water, while the stator core is cooled with ordinary air. Both the stator and rotor coils are live conductors, and the voltage across the stator and rotor coils varies depending on the generator capacity. In a 300MW dual water-cooled generator, the stator coils withstand 20kV during normal operation, while the rotor withstands 418V, generating a significant amount of heat on the rotor.

[0004] Currently, dual-water-cooled generators are equipped with a cooling water system. The cooling water is introduced to one end of the generator through the water inlet sealing box located at the excitation end of the generator rotor. Then, through two radial holes located at that end, the cooling water is thrown into the rotor coil water tank (the centrifugal force generated by the rotor rotation throws the cooling water into the tank). It is then distributed to the 18 rotor cooling hollow wires to absorb the heat generated by the generator rotor coil. Finally, the cooling water flows out from the steam end of the generator rotor and flows back to the water tank after being collected through the return water seat. This cycle repeats continuously.

[0005] Meanwhile, in the dual water-cooled generator, the cooling water system is equipped with a water shortage protection. To prevent the rotor coil from burning out due to lack of water, when the cooling water inlet flow rate is lower than 21t / h and the inlet water pressure is lower than 0.147MPa, the rotor cooling water protection is activated, and the output signal is delayed for 30 seconds to trip the generator. However, during the generator rotor cooling water cut-off protection test, if the unit is in the shutdown turning gear state (i.e., the generator is not working), and the rotor cooling water inlet pressure is controlled at 0.2-0.30MPa, the rotor cooling water flow rate is 8-10t / h. The rotor cooling water inlet pressure has an adjustment margin, but the rotor cooling water flow rate is too low at this time and cannot meet the protection transmission requirements (the generator itself generates suction when starting, and will generate resistance to the water when shutting down). If the unit is in the start-up process (i.e., when the generator starts), the turbine is at a constant speed of 3000rpm, and the rotor cooling water inlet pressure is controlled at 0.2-0.30MPa, the rotor cooling water flow rate is 42-45t / h. During the generator rotor cooling water cut-off protection test, when the generator rotor inlet water pressure has dropped to 0MPa, the rotor cooling water flow rate is still 30t / h, which is less than the protection action value of <21t / h, and the actual protection transmission conditions are not met.

[0006] Therefore, this application provides a water shortage protection test system capable of conducting water shortage protection tests on generator rotor cooling water. Utility Model Content

[0007] The main objective of this invention is to provide a water shortage protection test system capable of conducting water shortage protection tests on generator rotor cooling water.

[0008] To achieve the above objectives, the technical solution of this utility model is as follows: a water outage protection testing system, comprising:

[0009] Water tank, used to store cooling water;

[0010] The pumping branch has its input end connected to the water tank and its output end connected to the excitation end of the generator. It is used to draw cooling water from the water tank and pump it to the excitation end of the generator.

[0011] The first return water branch has its input end connected to the steam end of the generator and its output end connected to the water tank. It is used to guide the water output from the steam end of the generator into the water tank.

[0012] The second return water branch is equipped with a throttle valve. The input end of the second return water branch is connected to the output end of the pumping branch, and the output end of the second return water branch is connected to the water tank.

[0013] Furthermore, a flow meter is installed on the pumping branch, which is located in front of the connection node between the pumping branch and the second return water branch, and is used to measure the flow rate output by the pumping branch.

[0014] Furthermore, a primary filter assembly and a secondary filter assembly are connected in series on the pumping branch. The connection point between the second return water branch and the pumping branch is located between the primary filter assembly and the secondary filter assembly. The filtration accuracy of the primary filter assembly is lower than that of the secondary filter assembly. The primary filter assembly and the secondary filter assembly are used for graded filtration of cooling water.

[0015] Furthermore, the primary filter assembly and the secondary filter assembly each include two parallel filter branches, each filter branch is provided with a filter screen of corresponding precision, and each filter branch is also provided with a first switching valve, which is used to control the on / off state of the corresponding filter branch.

[0016] Furthermore, the first switching valve is installed at both ends of the corresponding filter screen in each filter branch.

[0017] Furthermore, a cooling assembly is also provided on the pumping branch, which is used to cool the cooling water output from the pumping branch.

[0018] Furthermore, the cooling assembly includes two parallel cooling branches, each of which is equipped with a cooler and a second switching valve for controlling the on / off state of the corresponding cooling branch.

[0019] Furthermore, a pumping assembly is provided at one end of the corresponding water tank of the pumping branch. The pumping assembly includes two pumps connected in parallel, and a third switch valve is provided on the pipeline where each pump is located to control the on / off state of the corresponding pipeline.

[0020] Furthermore, it also includes a third return water branch, the input end of which is connected to the output end of the water pump, the output end of which is connected to the water tank, and a fourth switch valve is provided on the third return water branch to control the on / off state of the third return water branch.

[0021] Furthermore, a steam-water separator is installed on the first return water branch.

[0022] The beneficial effects of this utility model are reflected in:

[0023] This invention solves the problem of existing cooling water systems being unable to conduct water shortage protection tests in the simplest and most convenient way by setting up a second return water branch. It can be directly modified on existing cooling water systems at a low cost. Attached Figure Description

[0024] In the attached diagram:

[0025] Figure 1 This is a schematic diagram illustrating the working principle of the water shortage protection test system described in this utility model.

[0026] Explanation of reference numerals in the attached figures:

[0027] 1. Water tank; 2. Pumping branch; 21. Flow meter; 22. Primary filter assembly; 23. Secondary filter assembly; 24. Filter screen; 25. First switching valve; 26. Cooling assembly; 27. Cooler; 28. Second switching valve; 29. ​​Pumping assembly; 291. Water pump; 292. Third switching valve; 3. First return water branch; 4. Second return water branch; 41. Throttling valve; 5. Generator; 6. Third return water branch; 61. Fourth switching valve; 7. Steam-water separator. Detailed Implementation

[0028] The present invention will now be described in further detail with reference to the accompanying drawings and embodiments. Obviously, the described embodiments are only a part of the embodiments of the utility model, and not all of them. Unless otherwise specified, the embodiments and features described in this application can be combined with each other. All other embodiments obtained by those skilled in the art based on the embodiments of the utility model without creative effort are within the scope of protection of the utility model.

[0029] See Figure 1 .

[0030] This utility model discloses a water shortage protection testing system, including:

[0031] Water tank 1 is used to store cooling water;

[0032] Pumping branch 2, whose input end is connected to water tank 1 and whose output end is connected to excitation end of generator 5, is used to draw cooling water from water tank 1 and pump it to excitation end of generator 5 (i.e., the inlet end of cooling water of generator 5).

[0033] The first return water branch 3 has its input end connected to the steam end of the generator 5 (i.e., the outlet end of the cooling water of the generator 5) and its output end connected to the water tank 1, which is used to guide the water output from the steam end of the generator 5 into the water tank 1.

[0034] The second return water branch 4 is equipped with a throttle valve 41 for adjusting the flow rate through the branch. The input end of the second return water branch 4 is connected to the output end of the pumping branch 2, and the output end of the second return water branch 4 is connected to the water tank 1.

[0035] In practice, when the cooling water system is working normally, the throttle valve 41 is closed, the second return water branch 4 is in a non-conducting state, the pumping branch 2 sends the cooling water pump 291 to the excitation end of the generator 5, and then outputs it from the steam end of the generator 5, returning to the water tank 1 through the first return water branch 3; when performing the water shortage protection test, there are two states depending on whether the generator 5 is started. If the generator 5 is started, the detection point is at the excitation end of the generator 5, and the throttle valve 41 is slowly opened. At this time, some water will flow from the second return water branch 4 The water flows back to water tank 1 to reduce the flow rate of the generator 5 rotor cooling water until it reaches the protection action value (i.e., <21t / h). If the generator 5 is shut down, the detection point is adjusted to the output end of the pumping branch 2. Then, the throttle valve 41 is opened (fully open) to reduce the system resistance, so that the flow rate output by the pumping branch 2 exceeds the protection action value. Then, the throttle valve 41 is slowly closed, so that the system resistance gradually increases and the flow rate output by the pumping branch 2 gradually decreases until it reaches the protection action value (i.e., <21t / h).

[0036] This utility model, through the setting of the second return water branch 4, solves the problem that the existing cooling water system cannot carry out water shortage protection test in the simplest and most convenient way. It can be directly modified on the existing cooling water system with low modification cost.

[0037] In one embodiment, a flow meter 21 is provided on the pumping branch 2. The flow meter 21 is located in front of the connection node between the pumping branch 2 and the second return water branch 4, and is used to measure the flow rate at the output end of the pumping branch 2.

[0038] In practice, when the generator 5 is running, a flow monitoring device can be installed on the second return water branch 4. The difference between the values ​​of the flow meter 21 and the flow monitoring device can be used to determine the flow rate of the generator 5 rotor cooling water. When the generator 5 is off, the throttle valve 41 can be adjusted to change the system resistance. By observing the value of the flow meter 21, the flow rate output by the pumping branch 2 can be determined.

[0039] In one embodiment, a primary filter assembly 22 and a secondary filter assembly 23 are connected in series on the pumping branch 2. The connection point between the second return water branch 4 and the pumping branch 2 is located between the primary filter assembly 22 and the secondary filter assembly 23. The filtration accuracy of the primary filter assembly 22 is less than that of the secondary filter assembly 23. The primary filter assembly 22 and the secondary filter assembly 23 are used for graded filtration of cooling water.

[0040] In practice, the primary filter assembly 22 is used to remove coarse mechanical impurities. After passing through the flow measurement orifice plate, fine impurities are filtered by the secondary filter assembly 23. This multi-stage filtration method results in fast filtration speed and relatively low system resistance. Since the water in the second return water branch 4 does not pass through the generator 5, it only needs to filter coarse impurities, resulting in even lower resistance and avoiding the backflow of coarse impurities. Therefore, this distribution method can simultaneously meet both requirements and is a reasonable design.

[0041] In one embodiment, the primary filter assembly 22 and the secondary filter assembly 23 each include two parallel filter branches, each filter branch is provided with a filter screen 24 of corresponding precision, and each filter branch is also provided with a first switching valve 25, which is used to control the on / off state of the corresponding filter branch.

[0042] In practice, during operation, only one filter branch is activated in each filter component. When the corresponding filter branch fails or requires maintenance, the filter branch is shut down and another filter branch is activated, thereby ensuring uninterrupted system operation and reducing downtime.

[0043] In one embodiment, the first switching valve 25 is disposed at both ends of the corresponding filter screen 24 in each filter branch. This design ensures that no water flows back to the filter screen 24, preventing the new filter screen 24 from contacting the cooling water and avoiding long-term immersion of the filter screen 24.

[0044] In one embodiment, a cooling assembly 26 is also provided on the pumping branch 2, which is used to cool the cooling water output from the pumping branch 2.

[0045] In practice, since the first return water branch 3 re-introduces the high-temperature water output from the steam end of the generator 5 into the water tank 1, the water temperature in the water tank 1 is relatively high. By adding the cooling component 26, it can be ensured that the water temperature entering the generator 5 again will not exceed the standard, and it is not necessary to increase the volume of the water tank 1 to cool it down.

[0046] In one embodiment, the cooling assembly 26 includes two parallel cooling branches, each cooling branch being equipped with a cooler 27 and a second switching valve 28 for controlling the on / off state of the corresponding cooling branch. The second switching valve 28 is located at both ends of the corresponding cooler 27 in each cooling branch.

[0047] In practice, during operation, only one cooling branch in the cooling assembly 26 is activated. When the corresponding cooling branch fails or requires maintenance, it is shut down and another cooling branch is activated, thus ensuring uninterrupted system operation and reducing downtime. Furthermore, second switching valves 28 are installed at both ends of the cooler 27 to ensure that water does not flow back into the cooler 27, preventing the new cooler 27 from contacting the cooling water and avoiding long-term immersion and corrosion.

[0048] In one embodiment, a pumping assembly 29 is provided at one end of the corresponding water tank 1 of the pumping branch 2. The pumping assembly 29 includes two pumps 291 connected in parallel. A third switch valve 292 is provided on the pipeline where each pump 291 is located to control the on / off state of the corresponding pipeline. The third switch valve 292 is located at both ends of the corresponding pump 291 in each corresponding pipeline.

[0049] In practice, only one water pump 291 is activated during operation. When the corresponding water pump 291 malfunctions or requires maintenance, it is shut down and another water pump 291 is activated, thus ensuring uninterrupted system operation and reducing downtime. Furthermore, a third switching valve 292 is installed at both ends of each water pump 291 to ensure that water does not flow back into the pump 291, preventing the new water pump 291 from contacting the cooling water and avoiding long-term immersion and corrosion.

[0050] In one embodiment, a third return water branch 6 is also included. The input end of the third return water branch 6 is connected to the output end of the water pump 291, and the output end of the third return water branch 6 is connected to the water tank 1. A fourth switch valve 61 is provided on the third return water branch 6 to control the on / off state of the third return water branch 6. With this design, when switching between different water pumps 291, the second water pump 291 can be turned on simultaneously. If the system pressure and flow rate are too high at this time, the corresponding water volume can be released by turning on the third return water branch 6. After the two water pumps 291 are turned on, the water pump 291 that was originally working when needed is turned off, and then the third return water branch 6 is turned off. In this way, the water pump 291 can be replaced while ensuring the system flow rate.

[0051] In one embodiment, a steam-water separator 7 is provided on the first return water branch 3. This design allows some of the cooling water to be vaporized after exiting the rotor, and the steam-water separator 7 can discharge the vaporized high-temperature gas, allowing the water to flow back to the water tank 1.

[0052] The above description is only a preferred embodiment of the present utility model and is not intended to limit the present utility model. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present utility model should be included within the protection scope of the present utility model.

[0053] It should be noted that if the utility model embodiment involves directional indicators (such as up and down), the directional indicators are only used to explain the relative positional relationship and movement of the components in a certain specific posture (as shown in the figure). If the specific posture changes, the directional indicators will also change accordingly.

[0054] Furthermore, the meaning of "and / or" throughout the text includes three parallel solutions. Taking "A and / or B" as an example, it includes solution A, solution B, or a solution that simultaneously satisfies A and B. Additionally, if the utility model embodiments involve descriptions of "first," "second," etc., these descriptions are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of indicated technical features. Therefore, features defined with "first" or "second" can explicitly or implicitly include at least one of those features. Furthermore, "multiple" refers to two or more. Additionally, the technical solutions of the various embodiments can be combined with each other, but this must be based on the ability of those skilled in the art to implement them. When the combination of technical solutions is contradictory or impossible to implement, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection claimed by the utility model.

Claims

1. A water shortage protection testing system, characterized in that, include: Water tank (1), used to store cooling water; The pumping branch (2) has its input end connected to the water tank (1) and its output end connected to the excitation end of the generator (5). It is used to draw cooling water from the water tank (1) and pump it to the excitation end of the generator (5). The first return water branch (3) has its input end connected to the steam end of the generator (5) and its output end connected to the water tank (1), which is used to guide the water output from the steam end of the generator (5) into the water tank (1). The second return water branch (4) is equipped with a throttle valve (41). The input end of the second return water branch (4) is connected to the output end of the pumping branch (2), and the output end of the second return water branch (4) is connected to the water tank (1).

2. The water shortage protection test system according to claim 1, characterized in that, A flow meter (21) is installed on the pumping branch (2). The flow meter (21) is located in front of the connection node between the pumping branch (2) and the second return water branch (4) and is used to measure the flow rate output by the pumping branch (2).

3. The water shortage protection test system according to claim 1 or 2, characterized in that, A primary filter assembly (22) and a secondary filter assembly (23) are connected in series on the pumping branch (2). The connection point between the second return water branch (4) and the pumping branch (2) is located between the primary filter assembly (22) and the secondary filter assembly (23). The filtration accuracy of the primary filter assembly (22) is less than that of the secondary filter assembly (23). The primary filter assembly (22) and the secondary filter assembly (23) are used for graded filtration of cooling water.

4. The water shortage protection test system according to claim 3, characterized in that, The primary filter assembly (22) and the secondary filter assembly (23) each include two parallel filter branches, each filter branch is provided with a filter screen (24) of corresponding precision, and each filter branch is also provided with a first switching valve (25), which is used to control the on / off state of the corresponding filter branch.

5. The water shortage protection test system according to claim 4, characterized in that, The first switching valve (25) is set at both ends of the corresponding filter screen (24) of each filter branch.

6. The water shortage protection test system according to claim 1 or 2, characterized in that, The pumping branch (2) is also equipped with a cooling assembly (26), which is used to cool the cooling water output from the pumping branch (2).

7. The water shortage protection test system according to claim 6, characterized in that, The cooling assembly (26) includes two parallel cooling branches, each of which is equipped with a cooler (27) and a second switching valve (28) for controlling the on / off state of the corresponding cooling branch.

8. The water shortage protection test system according to claim 1 or 2, characterized in that, A pumping assembly (29) is provided at one end of the corresponding water tank (1) of the pumping branch (2). The pumping assembly (29) includes two parallel water pumps (291). A third switch valve (292) is provided on the pipeline where each water pump (291) is located, for controlling the opening and closing of the corresponding pipeline.

9. The water shortage protection test system according to claim 8, characterized in that, It also includes a third return water branch (6), the input end of which is connected to the output end of the water pump (291), the output end of which is connected to the water tank (1), and a fourth switch valve (61) is provided on the third return water branch (6) to control the opening and closing of the third return water branch (6).

10. The water shortage protection test system according to claim 1 or 2, characterized in that, A steam-water separator (7) is installed on the first return water branch (3).

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