Method for detecting auxiliary water supply system of nuclear power station unit

Abstract

The invention discloses a method for detecting an auxiliary water supply system of a nuclear power station unit, and the method comprises the steps: building a temporary pipeline between an output pipeline and a circulation pipeline, and enabling liquid flowing out of a water tank to pass through the output pipeline, the temporary pipeline and the circulation pipeline when the auxiliary water supply system is subjected to an emergency water supply pump test and an emergency diesel generator set performance test; and finally, the water returns to the water tank and is not actually injected into the secondary side of the steam generator. According to the scheme, real water injection to the steam generator can be avoided only by laying one temporary pipeline, the method has the advantages of being simple in construction, short in temporary distance, simple in debugging and temporary management, controllable in water leakage risk and the like, meanwhile, the key path construction period can be effectively saved, a large amount of manpower and construction period investment can be saved, chemical adding operation can be avoided, and the cost is reduced. The detection risk is effectively controlled; whether the auxiliary water supply system meets the design requirement or not can be verified in advance under the condition that the secondary side of the steam generator does not have the water injection condition, problems are found and handled in time, and the hot test is prevented from being affected.

Description

Technical Field

[0001] This application relates to the field of nuclear power plant units, and particularly to a method for detecting the auxiliary feed water system of a nuclear power plant unit. Background Art

[0002] The auxiliary feed water system (ASG) is one of the necessary feed water systems on the secondary side of the steam generator (SG) in a nuclear power plant unit. When the normal main feed water system fails, the auxiliary feed water system supplies water to the secondary side of the steam generator, discharges the residual heat of the reactor core, and cools the reactor until the residual heat removal system (RRA) is put into operation; in addition, during normal operation of the unit, the auxiliary feed water system serves as a backup water source for the steam generator.

[0003] During the construction of a nuclear power plant unit, it is necessary to detect the auxiliary feed water system under two emergency conditions: the emergency feed water pump test (TP-ASG-11) and the emergency diesel generator set performance test (TP-BAS-55), to ensure that the auxiliary feed water system can operate normally under the above emergency conditions after being put into use. However, since the auxiliary feed water system is connected to the secondary side of the steam generator, directly conducting the emergency feed water pump test or the emergency diesel generator set performance test will inject real water into the secondary side of the steam generator. If the original plan is implemented, the secondary side of the steam generator needs to be switched from dry maintenance to wet maintenance. During the emergency feed water pump test or the emergency diesel generator set performance test, a series of complex operations such as adding medicine, sampling, and discharging the added medicine water are also involved. After the test is completed, the secondary side of the steam generator needs to be switched back from wet maintenance to dry maintenance again. The process is cumbersome and takes more than one month; at the same time, the emergency feed water pump test and the emergency diesel generator set performance test are generally carried out before the start of the hot test, and the secondary side of the steam generator needs to isolate the connected water inlet source for many tests before the hot test. This requirement conflicts with the requirements of the emergency feed water pump test and the emergency diesel generator set performance test; that is, implementing the emergency feed water pump test and the emergency diesel generator set performance test according to the original plan will affect the construction and commissioning of the secondary side system of the steam generator and greatly increase the construction time of the secondary side of the steam generator.

[0004] Therefore, it is necessary to develop a solution that does not require real water injection into the secondary side of the steam generator and can still cooperate with the emergency feed water pump test and the emergency diesel generator set performance test. Summary of the Invention

[0005] To solve one of the technical problems existing in the prior art, this application provides a method for detecting the auxiliary feed water system of a nuclear power plant unit, which does not require real water injection into the secondary side of the steam generator, avoids affecting the construction of the secondary side of the steam generator, and shortens the construction period.

[0006] A method for detecting the auxiliary feed water system of a nuclear power plant unit according to some embodiments of the present application. The auxiliary feed water system includes at least one water supply loop. The water supply loop includes a water tank. An output pipeline and a circulation pipeline are provided on the water tank. The output pipeline is connected to the secondary side of the steam generator, and a valve is provided between the output pipeline and the steam generator. A feed water pump is provided on the output pipeline. The circulation pipeline allows the liquid in the water tank to circulate. A circulation pump is provided on the circulation pipeline. Wherein, the detection method includes the following steps: Build a temporary pipeline between the output pipeline and the circulation pipeline, close at least one valve between the output pipeline and the steam generator. When detecting, the liquid flowing out of the water tank sequentially passes through the output pipeline, the temporary pipeline and the circulation pipeline, and finally returns to the water tank.

[0007] In some embodiments, a main output pipeline and a small flow pipeline are provided between the water tank and the output pipeline. The main output pipeline and the small flow pipeline converge to the output pipeline. A first valve and a first flow meter are provided on the main output pipeline. A second valve and a second flow meter are provided on the small flow pipeline. The detection method includes an emergency feed water pump test. The emergency feed water pump test includes the following steps: S1. Start the feed water pump and open the second valve, confirm that the small flow pipeline is operating normally, and record the flow rate of the small flow pipeline through the second flow meter; S2. Slowly open the first valve so that the liquid flowing out of the water tank flows through the main output pipeline, observe the first flow meter and the second flow meter, and confirm that when the flow rate of the main output pipeline reaches the first preset flow rate, the flow rate of the small flow pipeline is 0m 3 / h; S3. Continue to open the first valve and observe the first flow meter. When the flow rate of the main output pipeline reaches the second preset flow rate, stop operating the first valve and record the operating parameters of the feed water pump; S4. Slowly close the first valve, observe the first flow meter and the second flow meter, and confirm that when the flow rate of the main output pipeline drops to 0m 3 / h, the flow rate of the small flow pipeline reaches within the range of the third preset flow rate; S5. Close the second valve and the feed water pump.

[0008] In some embodiments, the first preset flow rate is less than 40m 3 / h to meet the requirements of small flow water supply.

[0009] In some embodiments, the first preset flow rate is 38m 3 / h.

[0010] In some embodiments, the second preset flow rate is greater than 1000m 3 / h to meet the requirements of small flow water supply.

[0011] In some embodiments, the second preset flow rate is 102.6 m 3 / h.

[0012] In some embodiments, the third preset flow rate is 23 m 3 / h to 38 m 3 / h.

[0013] In some embodiments, the auxiliary feed water system includes three of the water supply circuits, the water supply circuits including a first water supply circuit, a second water supply circuit, and a third water supply circuit, corresponding to three columns A / B / C respectively, and three sets of 10 kV emergency power supply systems for the nuclear island.

[0014] In some embodiments, the auxiliary feed water system includes inter-column connecting pipelines, the inter-column connecting pipelines connecting the output pipelines of the first water supply circuit, the second water supply circuit, and the third water supply circuit, such that the feed water pumps of any one of the water supply circuits can satisfy the function of supplying water to the steam generator via the three-column water supply circuits.

[0015] In some embodiments, power regulating valves and level regulating valves are respectively provided on the output pipelines of the first water supply circuit, the second water supply circuit, and the third water supply circuit, and the inter-column connecting pipelines are provided between the power regulating valves and the level regulating valves. The water supply power of the feed water pump can be regulated by the power regulating valve, and the final output flow rate of the output pipeline can be regulated by the level regulating valve.

[0016] In some embodiments, it is sufficient to provide the temporary pipeline on any one of the first water supply circuit, the second water supply circuit, and the third water supply circuit.

[0017] In some embodiments, one end of the temporary pipeline is connected to the inter-column connecting pipeline, and the other end of the temporary pipeline is connected to the circulation pipeline. Since the inter-column connecting pipeline connects the three water supply circuits in series, it is only necessary to remove a connecting valve assembly on the inter-column connecting pipeline and connect the temporary pipeline, thereby connecting the channel to the return water tank, so as to achieve the purpose of completing the test without injecting water into the steam generator.

[0018] In some embodiments, steps S1 to S5 are respectively executed on the first water supply circuit, the second water supply circuit, and the third water supply circuit.

[0019] In some embodiments, the detection method includes a performance test of the emergency diesel generator set. The performance test of the emergency diesel generator set is required to be completed before the end of the hot functional test of the steam generator. The performance test of the emergency diesel generator set includes the following steps: T1. Each time, a group of the water supply circuits is tested. The second valve in the water supply circuit is opened and the feed water pump is started, so that the liquid flowing out of the water tank sequentially passes through the output pipeline, the inter-column connection pipeline, the temporary pipeline and the circulation pipeline, and finally returns to the water tank in one of the water supply circuits. During this process, it is confirmed that the liquid flow rate through the output pipeline remains at a level greater than 75 m 3 / h; T2. After maintaining for a time t, the second valve and the feed water pump are closed; T3. Steps T1 to T2 are respectively executed for the other two groups of the water supply circuits to complete the performance test of the emergency diesel generator set.

[0020] In some embodiments, the time t is greater than 12 hours.

[0021] The beneficial effects of the present application include:

[0022] First, the method for detecting the auxiliary feed water system of the nuclear power plant unit in the present application first proposes a scheme of using a temporary pipeline to replace the water injection into the steam generator when performing the emergency feed water pump test and the performance test of the emergency diesel generator set for the auxiliary feed water system. This scheme only needs to lay one temporary pipeline, which can meet the operation requirements of multiple columns of water supply circuits from small flow rate to full flow rate, and has the advantages of simple construction, short temporary distance, simple temporary management during commissioning, and controllable risk of water leakage.

[0023] Second, after using the scheme of the present application, the real water injection into the steam generator can be avoided, which can effectively save the critical path construction period, save a large amount of manpower and construction period investment, and create conditions for the secondary side water pressure test of the steam generator and the construction of the relevant systems on the secondary side of the steam generator.

[0024] Third, the water quality requirements of the secondary side of the steam generator and the water quality of the water tank of the auxiliary feed water system are inconsistent. Before injecting real water into the steam generator, hydrazine and ammonia water need to be added to adjust the water quality, which belongs to a high-risk operation; using a temporary pipeline to perform the test can avoid the dosing operation and effectively control the test risk.

[0025] Fourth, using this scheme can verify in advance whether the parameters such as the pump flow rate and head in the auxiliary feed water system meet the design requirements under the condition that the secondary side of the steam generator does not have the water injection condition, discover problems in time and avoid affecting the hot test.

[0026] Other features and advantages of the present application will be described in the following specification, and in part will be obvious from the specification, or can be learned by implementing the present application. The objectives and other advantages of the present application can be realized and obtained by the structures specifically pointed out in the specification, claims, and drawings. Description of the Drawings

[0027] In order to more clearly illustrate the technical solutions of the present application, the present application will be further described below in conjunction with the drawings and embodiments. It should be understood that the following drawings only show some embodiments of the present application, and therefore should not be regarded as a limitation of the scope. For those of ordinary skill in the art, without creative efforts, other related drawings can also be obtained based on these drawings. In the drawings:

[0028] Figure 1 is a schematic structural diagram of the auxiliary feed water system of a nuclear power plant unit provided by the present application;

[0029] Figure 2 is a schematic diagram of the emergency feed water pump test provided by the present application;

[0030] Figure 3 is a schematic diagram of the performance test of the emergency diesel generator set provided by the present application.

[0031] Reference numeral description:

[0032] Auxiliary feed water system 10, steam generator 20;

[0033] First water supply circuit 100, water tank 110, main output pipeline 120, first valve 121, small flow pipeline 130, second valve 131, output pipeline 140, circulation pipeline 150, power regulating valve 160, liquid level regulating valve 170, second water supply circuit 200, third water supply circuit 300, temporary pipeline 400, inter-column connection pipeline 500, connection valve 510. Detailed Embodiments

[0034] The present application will be further described in detail below in conjunction with the drawings through specific embodiments. Similar elements in different embodiments are labeled with related similar element numbers. In the following embodiments, many detailed descriptions are provided to enable a better understanding of the present application. However, those skilled in the art can easily recognize that some of these features can be omitted in different situations, or can be replaced by other elements, materials, or methods. In some cases, some operations related to the present application are not shown or described in the specification to avoid the core part of the present application being overwhelmed by excessive descriptions. For those skilled in the art, it is not necessary to describe these related operations in detail, and they can fully understand the related operations based on the description in the specification and general technical knowledge in the art.

[0035] In addition, the features, operations, or characteristics described in the specification can be combined in any suitable manner to form various embodiments. At the same time, the steps or actions in the method description can also be reordered or adjusted in a manner obvious to those skilled in the art. Therefore, the various sequences in the specification and drawings are only for clearly describing a certain embodiment and do not mean a necessary sequence, unless it is stated otherwise that a certain sequence must be followed.

[0036] The serial numbers assigned to the components herein, such as "first", "second", etc., are only used to distinguish the described objects and do not have any sequential or technical meaning. And the "connection" and "coupling" mentioned in this application, unless otherwise specified, both include direct and indirect connection (coupling).

[0037] During the assembly and commissioning process of the nuclear power plant unit, one of the key paths for the preparation of the hot test of the nuclear power plant unit is the construction and commissioning of the secondary side of the steam generator. After the cold test, the secondary side of the steam generator is in a dry maintenance state, and the preparation for the secondary side hydrostatic test and the installation of the secondary side system are started.

[0038] The original test plan for the emergency feedwater pump test requires injecting liquid into the secondary side of the steam generator. If the original plan is implemented, the secondary side of the steam generator needs to be switched from dry maintenance to wet maintenance, involving a series of complex operations such as chemical dosing, sampling, and discharge of the dosing water. After completion, it also needs to be switched back to dry maintenance, which also affects the construction of the secondary side system.

[0039] The performance test of the emergency diesel generator set requires the auxiliary feedwater system to be online to the large-flow pipeline and inject truly into the secondary side of the steam generator. The performance test of the emergency diesel generator set includes the performance tests of three emergency diesel generators (LHP / LHQ / LHR), corresponding to three trains A / B / C respectively. Each train requires two days of construction period. If everything goes smoothly, the performance test of the emergency diesel generator set will occupy at least 6 days of the secondary side of the steam generator. The performance test of the emergency diesel generator set is generally carried out before the start of the hot test. At this time, the flushing of the ASP system, the flushing of the ARE system, the flushing of the sediment in the secondary side, and the defect elimination after flushing all require isolating the water inlet source of the secondary side of the steam generator, which conflicts with the requirements of the performance test of the emergency diesel generator set.

[0040] Therefore, it is best to modify the test plans for the emergency feedwater pump test and the performance test of the emergency diesel generator set so that it is not necessary to inject water into the secondary side of the steam generator to avoid affecting the construction of the secondary side of the steam generator.

[0041] The following combines Figures 1 to 3 the provided embodiments to further elaborate on the method for detecting the auxiliary feedwater system of the nuclear power plant unit proposed in this application.

[0042] As Figure 1As shown in the figure, an embodiment of the present application provides an auxiliary feedwater system 10, which is applied to a nuclear power plant unit and is used to assist in supplying water to the secondary side of a steam generator 20. The auxiliary feedwater system 10 includes at least one water supply loop. In some embodiments, the auxiliary feedwater system 10 may include three water supply loops, specifically including a first water supply loop 100, a second water supply loop 200, and a third water supply loop 300, corresponding to three columns A / B / C respectively, and three sets of 10 kV emergency power supply systems for the nuclear island. It should be understood that in other embodiments, the number of water supply loops of the auxiliary feedwater system 10 can also be set according to actual needs. Each water supply loop includes a water tank 110. A main output pipeline 120, a small flow pipeline 130, and a circulation pipeline 150 are arranged on the water tank 110. The main output pipeline 120 and the small flow pipeline 130 converge to an output pipeline 140. The output pipeline 140 is connected to the secondary side of the steam generator 20. A feedwater pump is arranged on the output pipeline 140. A first valve 121 and a first flowmeter are arranged on the main output pipeline 120. A second valve 131 and a second flowmeter are arranged on the small flow pipeline 130. The circulation pipeline 150 can supply the liquid in the water tank 110 to circulate. A circulation pump is arranged on the circulation pipeline 150. In addition, a temporary pipeline 400 is built between the output pipeline 140 and the circulation pipeline 150, so that the liquid flowing out of the water tank 110 can sequentially pass through the output pipeline 140, the temporary pipeline 400, and the circulation pipeline 150, and finally return to the water tank 110. The method for detecting the auxiliary feedwater system of a nuclear power plant unit in the present application first proposes that when performing an emergency feedwater pump test and an emergency diesel generator set performance test on the auxiliary feedwater system 10, a temporary pipeline 400 is used instead of the scheme of injecting water into the steam generator 20. This scheme only needs to lay one temporary pipeline 400, which can meet the operation requirements of multiple columns of water supply loops from small flow to full flow, and has the advantages of simple construction, short temporary distance, simple temporary management during commissioning, and controllable water leakage risk. After using the scheme of the present application, injecting water into the steam generator 20 is avoided, which can effectively save the critical path construction period, save a large amount of manpower and construction period investment, and create conditions for the construction of the secondary side water pressure of the steam generator 20 and the related systems on the secondary side of the steam generator 20. The water quality requirements of the secondary side of the steam generator 20 and the water quality of the water tank 110 of the auxiliary feedwater system 10 are inconsistent. Before injecting water into the steam generator 20, hydrazine and ammonia water need to be added to adjust the water quality, which belongs to a high-risk operation. Using the temporary pipeline 400 of this scheme to perform the test can avoid the dosing operation and effectively control the test risk. Using this scheme can verify in advance whether the parameters such as the pump flow and head in the auxiliary feedwater system 10 meet the design requirements under the condition that the secondary side of the steam generator 20 does not have the condition for water injection, discover problems in time, and avoid affecting the hot test.

[0043] As Figure 2 shown, the detection method of the present application includes an emergency feedwater pump test, and the emergency feedwater pump test includes the following steps:

[0044] S1. Start the feed water pump and open the second valve 131. Confirm that the small flow pipeline 130 is operating normally, and record the flow rate of the small flow pipeline 130 through the second flowmeter.

[0045] S2. Slowly open the first valve 121 to allow the liquid flowing out of the water tank 110 to flow through the main output pipeline 120. Observe the first flowmeter and the second flowmeter, and confirm that when the flow rate of the main output pipeline 120 reaches the first preset flow rate, the flow rate of the small flow pipeline 130 is 0 m 3 / h.

[0046] S3. Continue to open the first valve 121 and observe the first flowmeter. After the flow rate of the main output pipeline 120 reaches the second preset flow rate, stop operating the first valve 121 and record the operating parameters of the feed water pump.

[0047] S4. Slowly close the first valve 121, observe the first flowmeter and the second flowmeter, and confirm that when the flow rate of the main output pipeline 120 drops to 0 m 3 / h, the flow rate of the small flow pipeline 130 reaches the third preset flow rate.

[0048] S5. Close the second valve 131 and the feed water pump.

[0049] It should be noted that since a temporary pipeline 400 has been built between the output pipeline 140 and the circulation pipeline 150 before the emergency feed water pump test of this application, during the emergency feed water pump test, the liquid flowing out of the water tank 110 passes through the output pipeline 140, the temporary pipeline 400 and the circulation pipeline 150 in sequence, and finally returns to the water tank 110 without actually entering the secondary side of the steam generator 20.

[0050] In some embodiments, further, steps S1 to S5 are respectively executed on the first water supply loop 100, the second water supply loop 200 and the third water supply loop 300 to ensure that each water supply loop can pass the emergency feed water pump test.

[0051] In some embodiments, further, in the above step S2, the first preset flow rate is less than 40 m 3 / h, meeting the requirements of small flow water supply. Further, the first preset flow rate is preferably 38 m 3 / h.

[0052] In some embodiments, further, in the above step S3, the second preset flow rate is greater than 100 m 3 / h, meeting the requirements of large flow water supply. Further, the second preset flow rate is preferably 102.6 m 3 / h.

[0053] In some embodiments, further, in the above step S4, the third preset flow rate is 23 m 3 / h to 38 m 3 / h.

[0054] In addition, as Figure 1 shown, in some embodiments, the auxiliary water supply system 10 includes an inter-column connection pipeline 500, and the inter-column connection pipeline 500 connects the output pipelines 140 of the first water supply loop 100, the second water supply loop 200, and the third water supply loop 300. Thus, the feed water pump of any one water supply loop can meet the function of supplying water to the steam generator 20 through three columns of water supply loops. Further, a connection valve 510 can be provided at each connection point between the inter-column connection pipeline 500 and each water supply loop. Through the connection valve 510, it can be controlled whether the water supply loop enters the inter-column connection pipeline 500 to achieve the control of series connection. When a certain water supply loop needs to be repaired and maintained, the connection between this water supply loop and the inter-column connection pipeline 500 can be shut off through the connection valve 510 to avoid the impact of its maintenance on other water supply loops.

[0055] As Figure 1 shown, in some embodiments, power regulating valves 160 and liquid level regulating valves 170 are respectively provided on the output pipelines 140 of the first water supply loop 100, the second water supply loop 200, and the third water supply loop 300, and the inter-column connection pipeline 500 is arranged between the power regulating valve 160 and the liquid level regulating valve 170. The water supply power of the feed water pump can be adjusted through the power regulating valve 160, and the final output flow rate of the output pipeline 140 can be adjusted through the liquid level regulating valve 170.

[0056] As Figure 1 shown, in some embodiments, in step S1, a temporary pipeline 400 can be provided on any one of the first water supply loop 100, the second water supply loop 200, and the third water supply loop 300. Further, one end of the temporary pipeline 400 is connected to the inter-column connection pipeline 500, and the other end of the temporary pipeline 400 is connected to the circulation pipeline 150. Since the inter-column connection pipeline 500 connects the three water supply loops in series, only one component of the connection valve 510 needs to be removed from the inter-column connection pipeline 500 and the temporary pipeline 400 is connected, then the channel to the return water tank 110 can be connected, so as to achieve the purpose of completing the test without injecting water into the steam generator 20.

[0057] As Figure 3As shown, the detection method further includes the performance test of the emergency diesel generator set. The performance test of the emergency diesel generator set is a prerequisite for the power supply switching test during the hot test. Therefore, the performance test of the emergency diesel generator set is required to be completed before the end of the hot functional test of the steam generator 20 to verify the diesel engine loading performance and the ability to shed the maximum single load to verify the response ability of the diesel generator set. At the same time, the flushing of the ASP system, the flushing of the ARE system, the flushing of the secondary side sediment, and the defect elimination after flushing all require isolating the water inlet source of the secondary side of the evaporator. Therefore, the performance test of the emergency diesel generator set needs to avoid real water injection into the secondary side of the steam generator 20. In some embodiments of the present application, the performance test of the emergency diesel generator set includes the following steps:

[0058] T1. Each time a group of water supply circuits is tested, open the second valve 131 in the water supply circuit and start the feed water pump, so that the liquid flowing out of the water tank 110 passes through the output pipeline 140, the inter-column connection pipeline 500, the temporary pipeline 400, and the circulation pipeline 150 in sequence, and finally returns to the water tank 110 in one of the water supply circuits. During this process, confirm that the liquid flow rate through the output pipeline 140 remains at a level greater than 75m 3 / h;

[0059] T2. After maintaining for a time t, close the second valve 131 and the feed water pump;

[0060] T3. Perform steps T1 to T2 on the other two groups of water supply circuits respectively to complete the performance test of the emergency diesel generator set.

[0061] It should be noted that since a temporary pipeline 400 has been built between the output pipeline 140 and the circulation pipeline 150 before the performance test of the emergency diesel generator set in the present application, and the performance test of the emergency diesel generator set has no requirement on where to inject water for the equipment except that real water injection into the secondary side of the steam generator 20 is not allowed, the on-site can select the water injection flow direction and its corresponding valves and circulation pipelines according to the actual state of the load. Therefore, during the performance test of the emergency diesel generator set, the liquid flowing out of the water tank 110 passes through the output pipeline 140, the inter-column connection pipeline 500, the temporary pipeline 400, and the circulation pipeline 150 in sequence, and finally returns to the water tank 110 in any one of the water supply circuits, avoiding the secondary side water injection of the steam generator 20 and affecting the construction of the secondary side of the steam generator 20.

[0062] In some embodiments, further, the time t is greater than 12 hours to ensure that the diesel generator set can run for a long time in case of emergency. Further, the time t is preferably 24 hours. Through the performance test of the emergency diesel generator set of the present application, 7 days of the actual test duration can be saved.

[0063] In addition, the method for detecting the auxiliary feed water system of a nuclear power plant unit in this application has been applied during the construction of some nuclear power plant units, bringing the following advantages:

[0064] First, the method for detecting the auxiliary feed water system of a nuclear power plant unit in this application first proposes that when performing the emergency feed pump test and the performance test of the emergency diesel generator set on the auxiliary feed water system 10, a temporary pipeline 400 is used instead of the scheme of injecting water into the steam generator 20. This scheme only needs to lay one temporary pipeline 400, which can meet the operation requirements of multiple water supply circuits from small flow to full flow, and has the advantages of simple construction, short temporary distance, simple temporary management during commissioning, and controllable water leakage risk.

[0065] Second, after using the scheme of this application, the actual water injection into the steam generator 20 can be avoided, which can effectively save the critical path construction period and save a large amount of manpower and construction period investment, creating conditions for the construction of the secondary side water pressure of the steam generator 20 and the related systems on the secondary side of the steam generator 20.

[0066] Third, the water quality requirements of the secondary side of the steam generator 20 and the water quality of the water tank 110 of the auxiliary feed water system 10 are inconsistent. Before injecting water into the steam generator 20 actually, hydrazine and ammonia water need to be added to adjust the water quality, which belongs to high-risk operation; using the temporary pipeline 400 of this scheme to perform the test can avoid the dosing operation and effectively control the test risk.

[0067] Fourth, using this scheme can verify in advance whether the parameters such as the pump flow rate and head in the auxiliary feed water system 10 meet the design requirements under the condition that the secondary side of the steam generator 20 does not have the water injection condition, find problems in time and avoid affecting the hot test.

[0068] It can be understood that the above embodiments only represent the preferred implementation modes of this application, and the description is relatively specific and detailed, but it cannot be understood as a limitation to the patent scope of this application; it should be pointed out that for those of ordinary skill in the art, without departing from the concept of this application, the above technical features can be freely combined, and several deformations and improvements can also be made, which all belong to the protection scope of this application; therefore, all equivalent transformations and modifications made to the scope of the claims of this application should fall within the scope covered by the claims of this application.

Claims

1. A method for detecting the auxiliary feed water system of a nuclear power plant unit, characterized in that, The auxiliary feed water system includes at least one water supply loop, the water supply loop includes a water tank, an output pipeline and a circulation pipeline are arranged on the water tank, the output pipeline is connected to the secondary side of the steam generator and a valve is arranged between the output pipeline and the steam generator, a feed water pump is arranged on the output pipeline, the circulation pipeline allows the liquid in the water tank to circulate, and a circulation pump is arranged on the circulation pipeline; Wherein, the detection method includes the following steps: Build a temporary pipeline between the output pipeline and the circulation pipeline, close at least one valve between the output pipeline and the steam generator. When performing detection, the liquid flowing out of the water tank sequentially passes through the output pipeline, the temporary pipeline and the circulation pipeline, and finally returns to the water tank.

2. The method for detecting the auxiliary feed water system of a nuclear power plant unit according to claim 1, wherein, A main output pipeline and a small flow pipeline are arranged between the water tank and the output pipeline, the main output pipeline and the small flow pipeline converge into the output pipeline, a first valve and a first flowmeter are arranged on the main output pipeline, and a second valve and a second flowmeter are arranged on the small flow pipeline; The detection method includes an emergency feed water pump test, and the emergency feed water pump test includes the following steps: S1. Start the feed water pump and open the second valve, confirm that the small flow pipeline is operating normally, and record the flow rate of the small flow pipeline through the second flowmeter; S2. Slowly open the first valve to allow the liquid flowing out of the water tank to flow through the main output pipeline. Observe the first flowmeter and the second flowmeter, and confirm that when the flow rate of the main output pipeline reaches the first preset flow rate, the flow rate of the small flow pipeline is 0 m 3 / h; S3. Continue to open the first valve and observe the first flowmeter. When the flow rate of the main output pipeline reaches the second preset flow rate, stop operating the first valve and record the operating parameters of the feed water pump; S4. Slowly close the first valve, observe the first flowmeter and the second flowmeter, and confirm that when the flow rate in the main output pipeline drops to 0 m 3 / h, the flow rate in the small flow pipeline reaches within the range of the third preset flow rate; S5. Close the second valve and the feed water pump.

3. The method for detecting the auxiliary feed water system of a nuclear power plant unit according to claim 2, characterized in that, The first preset flow rate is less than 40 m 3 / h.

4. The method for detecting the auxiliary feed water system of a nuclear power plant unit according to claim 3, characterized in that The first preset flow rate is 38 m 3 / h.

5. The method for detecting the auxiliary feed water system of a nuclear power plant unit according to claim 2, characterized in that, The second preset flow rate is greater than 100 m 3 / h.

6. The method for detecting the auxiliary feed water system of a nuclear power plant unit according to claim 5, wherein The second preset flow rate is 102.6 m 3 / h.

7. The method for detecting the auxiliary feed water system of a nuclear power plant unit according to claim 2, wherein, The third preset flow rate is 23 m 3 / h to 38 m 3 / h.

8. The method for detecting the auxiliary feed water system of a nuclear power plant unit according to any one of claims 2 to 7, characterized in that, The auxiliary feed water system includes three of the water supply loops, and the water supply loop includes a first water supply loop, a second water supply loop and a third water supply loop.

9. The method for detecting the auxiliary feed water system of a nuclear power plant unit according to claim 8, wherein, The auxiliary feed water system includes an inter-column connection pipeline, and the inter-column connection pipeline connects the output pipelines of the first water supply loop, the second water supply loop and the third water supply loop.

10. The method for detecting the auxiliary feed water system of a nuclear power plant unit according to claim 9, wherein, Power regulating valves and liquid level regulating valves are respectively arranged on the output pipelines of the first water supply loop, the second water supply loop and the third water supply loop, and the inter-column connection pipeline is arranged between the power regulating valve and the liquid level regulating valve.

11. The method for detecting the auxiliary feed water system of a nuclear power plant unit according to claim 9, characterized in that, It is sufficient to set the temporary pipeline on any one of the first water supply loop, the second water supply loop and the third water supply loop.

12. The method for detecting the auxiliary feed water system of a nuclear power plant unit according to claim 11, wherein, One end of the temporary pipeline is connected to the inter-column connection pipeline, and the other end of the temporary pipeline is connected to the circulation pipeline.

13. The method for detecting the auxiliary feed water system of a nuclear power plant unit according to claim 9, wherein Steps S1 to S5 are respectively executed for the first water supply loop, the second water supply loop and the third water supply loop.

14. The method for detecting the auxiliary feed water system of a nuclear power plant unit according to claim 9, characterized in that, The detection method includes an emergency diesel generator set performance test, and the emergency diesel generator set performance test is required to be completed before the end of the hot state function test of the steam generator. The emergency diesel generator set performance test includes the following steps: T1. Each time a group of the water supply circuits is tested, open the second valve in the water supply circuit and start the feed water pump, so that the liquid flowing out of the water tank sequentially passes through the output pipeline, the inter-column connection pipeline, the temporary pipeline and the circulation pipeline, and finally returns to the water tank in one of the water supply circuits. During this process, confirm that the liquid flow rate through the output pipeline remains at a level greater than 75 m 3 / h; T2. After maintaining for time t, close the second valve and the feed water pump; T3. Steps T1 to T2 are respectively executed for the other two groups of the water supply loops to complete the emergency diesel generator set performance test.

15. The method for detecting the auxiliary feed water system of a nuclear power plant unit according to claim 14, wherein The time t is greater than 12 hours.

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