A cooling device for a frequency converter in a nuclear power plant

Abstract

The present invention discloses a cooling device for a nuclear power plant frequency converter, comprising a cooling water tank, a working module, and a delivery module. The cooling water tank is provided with an isolation device on its exterior; the working module is disposed within a frequency converter cabinet and is used to cool the equipment within the cabinet; the delivery module is disposed within the cooling cabinet, which is located on one side below the cooling water tank. The delivery module is connected to the cooling water tank and the working module and is used to deliver coolant from the cooling water tank to the working module. This system can water-cool the equipment while avoiding short circuits caused by leakage in the cooling water tank or pipelines, preventing damage to electrical equipment and ensuring the normal operation of the main helium blower.

Description

Technical Field

[0001] The present invention relates to the technical field of nuclear power equipment, and in particular to a cooling device for a frequency converter in a nuclear power plant. Background Art

[0002] The main helium blower in the high-temperature reactor of a nuclear power plant is powered and regulated by a frequency converter. Specifically, the 6kV auxiliary power system provides power to the frequency converter via a circuit breaker cabinet, which then powers the drive motor that drives the main helium blower. Heat generated by the frequency converter cabinet is removed through a coolant circulation system. This system pressurizes the coolant through a transfer pump and delivers it to a pipe near the frequency converter to dissipate the heat. After the heated coolant dissipates the heat, it returns through a pipe to the transfer pump inlet, completing a circuit. The cooling water tank serves as a high-level buffer pool, ensuring stable operation of the cooling system. When the coolant temperature rises, a thermostatic valve switches the cooling system to outdoor circulation, where it is cooled by an outdoor heat exchanger.

[0003] The problems with the above-mentioned cooling device include: 1. The cooling water tank is located in a narrow frequency converter cabinet and is made of non-transparent material, making it difficult to monitor the liquid level; 2. The cooling water tank is arranged at a high position and the motor is arranged at a low position. Other electrical equipment is also arranged between the bottom of the cooling water tank and the motor. Once the cooling water tank leaks, it will cause the electrical equipment to short-circuit, causing tripping or even fire. At the same time, the cooling device will stop working, causing the main helium fan to trip, the reactor to shut down unplanned, and cause damage to electrical equipment and even personal injury. Summary of the Invention

[0004] In view of this, the present invention provides a cooling device for a nuclear power plant frequency converter, which can avoid short circuits caused by leakage of cooling water tanks or pipelines while water-cooling the equipment, prevent damage to electrical equipment, and ensure the normal operation of the main helium blower.

[0005] An embodiment of the present invention provides a cooling device for a nuclear power plant frequency converter, comprising a cooling water tank, a working module and a conveying module, wherein an isolation device is provided on the outside of the cooling water tank; the working module is provided inside a frequency converter cabinet and is used to cool the equipment inside the frequency converter cabinet; the conveying module is provided inside the cooling cabinet, the cooling cabinet is located on one side below the cooling water tank, the conveying module is connected to the cooling water tank and the working module, and is used to convey the coolant in the cooling water tank to the working module.

[0006] Furthermore, the cooling device of the nuclear power plant converter also includes a first liquid inlet pipe and a first liquid outlet pipe. A first liquid outlet is provided at the bottom of the cooling water tank, and the first liquid inlet pipe connects the first liquid outlet and the inlet of the conveying module; the first liquid outlet pipe connects the outlet of the conveying module and the inlet of the working module, and the outlet of the working module is connected to the first liquid inlet pipe to realize the circulation of the coolant.

[0007] Furthermore, the cooling device of the nuclear power plant converter also includes a first shut-off valve and a second shut-off valve. The first shut-off valve is arranged on the first liquid inlet pipe and is located between the first liquid outlet and the conveying module; the second shut-off valve is arranged on the first liquid outlet pipe and is located between the conveying module and the working module.

[0008] Furthermore, the isolation device includes a protective plate and a guide plate. The protective plate is located on the side of the cooling water tank and is used to isolate the leakage; the guide plate is located below the cooling water tank, and a second liquid outlet is provided at the lowest point of the guide plate, and the second liquid outlet is used to discharge the leakage.

[0009] Furthermore, the working module includes a frequency converter heat exchanger.

[0010] Furthermore, the delivery module includes a delivery pump and a motor. The delivery pump is used to pressurize the coolant, and there is at least one delivery pump. The motor is connected to the delivery pump, and the motor is used to drive the delivery pump.

[0011] Furthermore, when the number of delivery pumps is two or more, the delivery pumps are arranged in parallel.

[0012] Furthermore, the cooling device of the frequency converter of the nuclear power plant further includes a liquid level gauge, which is connected to the cooling water tank and is used to measure the liquid level in the cooling water tank.

[0013] Furthermore, a third shut-off valve is provided at the top of the liquid level gauge; and a fourth shut-off valve is provided at the bottom of the liquid level gauge.

[0014] The beneficial effects of the technical solution provided by the embodiment of the present invention include at least the following: a cooling device for a nuclear power plant frequency converter, comprising a cooling water tank, a working module, and a conveying module, wherein an isolation device is provided on the outside of the cooling water tank; the working module is provided inside the frequency converter cabinet and is used to cool the equipment inside the frequency converter cabinet; the conveying module is provided inside the cooling cabinet, the cooling cabinet is located on one side below the cooling water tank, the conveying module is connected to the cooling water tank and the working module, and is used to convey the coolant in the cooling water tank to the working module. Thus, the physical isolation of the cooling water tank, the working module, and the conveying module is achieved, and while water-cooling the equipment inside the frequency converter cabinet, short circuits caused by leakage in the cooling water tank or pipelines can be avoided, damage to electrical equipment can be prevented, and the normal operation of the main helium blower can be ensured.

[0015] Among them, a liquid level gauge is set on the outside of the cooling water tank, which can observe the liquid level changes in the cooling water tank in real time and judge the reliability of the cooling device operation.

[0016] The above description is only an overview of the technical solution of the present application. In order to more clearly understand the technical means of the present application, it can be implemented in accordance with the contents of the specification. In order to make the above and other purposes, features and advantages of the present application more obvious and easy to understand, the specific implementation methods of the present application are listed below. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Various other advantages and benefits will become apparent to those skilled in the art upon reading the detailed description of the preferred embodiment below. The accompanying drawings are for illustration purposes only and are not to be considered as limiting the present invention. The same reference numerals are used throughout the accompanying drawings to denote the same components.

[0018] Figure 1 The schematic diagram of the structure of the existing cooling device for the frequency converter of a nuclear power plant is shown;

[0019] Figure 2 A schematic structural diagram of a cooling device for a nuclear power plant frequency converter provided by an embodiment of the present invention is shown.

[0020] in, Figures 1 to 2 The corresponding relationship between the reference numerals and component names is as follows:

[0021] 101 first valve, 102 second valve, 103 third valve, 104 fourth valve, 105 fifth valve, 111 first filter, 112 second filter, 121 first delivery pump, 122 second delivery pump, 123 third delivery pump, 131 water inlet;

[0022] 1 Cooling water tank, 11 First liquid outlet, 12 Isolation device, 13 Protective plate, 14 Guide plate, 15 Second liquid outlet, 2 Working module, 21 Frequency converter cabinet, 22 Frequency converter heat exchanger, 3 Delivery module, 31 Cooling cabinet, 32 Delivery pump, 33 Motor, 4 First liquid inlet pipe, 41 First shut-off valve, 5 First liquid outlet pipe, 51 Second shut-off valve, 6 Liquid level gauge, 61 Third shut-off valve, 62 Fourth shut-off valve. DETAILED DESCRIPTION

[0023] In order to more clearly understand the above-mentioned objects, features and advantages of the present invention, the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments. It should be noted that the embodiments of the present invention and the features therein can be combined with each other without conflict.

[0024] In the following description, many specific details are set forth to facilitate a full understanding of the present invention. However, the present invention may also be implemented in other ways different from those described herein. Therefore, the scope of protection of the present invention is not limited to the specific embodiments disclosed below.

[0025] Refer to the following Figures 1 to 2 A cooling device for a nuclear power plant converter provided according to some embodiments of the present invention is described.

[0026] The nuclear power plant's high-temperature reactor's main helium blower is powered and speed-regulated by a variable frequency drive (VFD). Because the blower's drive requires speed regulation from 20% to 105%, rapid braking within 20 seconds, and load following, a Rockwell Automation PowerFlex 7000 medium-voltage AC drive - liquid-cooled ("C" frame liquid-cooled VFD) is used as the VFD for the main helium blower. This drive uses a closed-loop cooling system for the converter's main power components and integrated DC link inductor. A cooling water tank serves as a high-level buffer reservoir. 200 liters of coolant are stored within the VFD cabinet, with approximately 170 liters circulating in the cooling system's pipes to ensure stable operation.

[0027] like Figure 1 As shown, the inverter, cooling water tank, filter, pipes, valves and other equipment are all installed inside the inverter cabinet. The above structure leads to the following problems in the cooling device: 1. The cooling water tank is located in a narrow inverter cabinet and is made of non-transparent material, making it difficult to monitor the liquid level; 2. The cooling water tank is arranged at a high position, while the motor and delivery pump are arranged at a low position. Other electrical equipment is also arranged between the bottom of the cooling water tank and the motor and delivery pump. Once the cooling water tank leaks, it will cause a short circuit in the electrical equipment, causing damage to the electrical equipment or even personal injury.

[0028] like Figure 2 As shown, a cooling device for a nuclear power plant frequency converter provided according to an embodiment of the present invention includes a cooling water tank 1, a working module 2, and a delivery module 3. An isolation device 12 is provided on the exterior of the cooling water tank 1; the working module 2 is disposed within a frequency converter cabinet 21 and is used to cool the equipment within the frequency converter cabinet 21; and the delivery module 3 is disposed within a cooling cabinet 31, which is located on one side below the cooling water tank 1. The delivery module 3 is connected to the cooling water tank 1 and the working module 2 and is used to deliver coolant from the cooling water tank 1 to the working module 2. Thus, by physically isolating the cooling water tank 1, the working module 2, and the delivery module 3, water cooling of the frequency converter cabinet 21 is achieved while avoiding short circuits caused by leakage from the cooling water tank 1 or pipelines, preventing damage to electrical equipment, and ensuring the normal operation of the main helium blower.

[0029] Specifically, the cooling water tank 1 is removed from the original frequency conversion cabinet 21 and set on a side away from the frequency conversion cabinet 21 and the cooling cabinet 31. An isolation device 12 is set on the outside of the cooling water tank 1. Once the cooling water tank 1 leaks, the isolation device 12 can prevent the coolant from flowing into the electrical equipment and causing a short circuit. Preferably, the cooling water tank 1 is set 50 cm behind the cooling cabinet 31, which can prevent the leaked coolant from flowing into the electrical equipment, while ensuring that the length of the pipeline is appropriate so that the coolant can fully circulate under the action of the conveying module 3. The working module 2 is retained inside the frequency conversion cabinet 21 and is used to cool the equipment inside the frequency conversion cabinet 21; the conveying module 3 is removed from the original frequency conversion cabinet 21, and a cooling cabinet 31 is set to accommodate the conveying module 3. This can prevent the electrical equipment inside the frequency conversion cabinet 21 from being damaged when the pipeline connecting the conveying module 3 leaks, thereby ensuring the normal operation of the main helium blower.

[0030] like Figure 2 As shown, the cooling device of the nuclear power plant converter also includes a first liquid inlet pipe 4 and a first liquid outlet pipe 5. A first liquid outlet 11 is provided at the bottom of the cooling water tank 1. The first liquid inlet pipe 4 connects the first liquid outlet 11 and the inlet of the conveying module 3; the first liquid outlet pipe 5 connects the outlet of the conveying module 3 and the inlet of the working module 2. The outlet of the working module 2 is connected to the first liquid inlet pipe 4 to realize the circulation of the coolant.

[0031] Specifically, under the action of gravity, the coolant in the cooling water tank 1 flows out of the first liquid outlet 11 and enters the delivery module 3 through the first liquid inlet pipe 4. The delivery module 3 pressurizes the coolant and pumps it into the working module 2, removing the heat generated by the electrical equipment inside the frequency converter cabinet 21. After the heat is dissipated, the heated coolant returns to the delivery module 3 and is pumped into the working module 2 again, thus achieving the recycling of the coolant. Among them, the cooling water tank 1 serves as a high-level buffer water pool to ensure the stable operation of the cooling device.

[0032] like Figure 2 As shown, the cooling device of the nuclear power plant inverter also includes a first shut-off valve 41 and a second shut-off valve 51. The first shut-off valve 41 is disposed on the first liquid inlet pipe 4, located between the first liquid outlet 11 and the delivery module 3. The first shut-off valve 41 is used to cut off the coolant entering the delivery module 3. The second shut-off valve 51 is disposed on the first liquid outlet pipe 5, located between the delivery module 3 and the working module 2. The second shut-off valve 51 is used to cut off the coolant pumped out of the delivery module 3, thereby controlling the operating state of the inverter heat exchanger 22. It will be understood that when the delivery module 3 is being inspected and repaired, the first shut-off valve 41 and the second shut-off valve 51 can be closed simultaneously to prevent coolant leakage from the pipeline.

[0033] like Figure 2As shown, the isolation device 12 includes a protective plate 13 and a deflector 14. The protective plate 13 is located on the side of the cooling water tank 1 and is used to isolate liquid leakage, preventing leakage from flowing into the electrical equipment below and causing a short circuit in the event of a cooling water tank malfunction. It should be understood that there is no specific number of protective plates 13; they only need to prevent leakage from the cooling water tank 1. Preferably, the protective plate 13 is placed on the side of the cooling water tank 1 near the cooling cabinet 31 to facilitate observation of the cooling device during maintenance without obstructing the view.

[0034] like Figure 2 As shown, the guide plate 14 is located below the cooling water tank 1, and a second liquid outlet 15 is provided at the lowest point of the guide plate 14. The second liquid outlet 15 is used to discharge leaked liquid. Specifically, the guide plate 14 is a funnel-shaped structure, the cooling water tank 1 is located on the higher side of the guide plate 14, and the second liquid outlet 15 is located at the lowest point of the guide plate 14. It is understandable that when the cooling water tank 1 is in normal working condition, the second liquid outlet 15 is not needed. Only when the cooling water tank 1 leaks due to a malfunction, the leaked liquid can be collected at the second liquid outlet 15 through the guide plate 14. A second liquid outlet pipe is connected at the second liquid outlet 15 to discharge the leaked liquid in time and avoid short circuit of the electrical equipment.

[0035] The protective plate 13 and the guide plate 14 are made of stainless steel plates or plastic plates. Preferably, in some possible embodiments, the guide plate 14 is made of multiple stainless steel plates to achieve a funnel-shaped structure.

[0036] like Figure 2 As shown, the working module 2 includes a frequency converter heat exchanger 22 for water cooling the equipment inside the frequency converter cabinet 21 .

[0037] like Figure 2 As shown, the delivery module 3 includes a delivery pump 32 and a motor 33. The delivery pump 32 is used to pressurize the coolant. There is at least one delivery pump 32. The motor 33 is connected to the delivery pump 32 and is used to drive the delivery pump 32. Specifically, the coolant in the cooling water tank 1 flows into the delivery pump 32 under the action of gravity. The motor 33 drives the delivery pump 32 to pressurize the coolant, so that the coolant can be pumped into the working module 2 through the first liquid outlet pipe 5. After completing the cooling function, the coolant is merged into the first liquid inlet pipe 4 and returned to the delivery pump 32, realizing the recycling of the coolant.

[0038] It is understood that the specific number of the delivery pumps 32 is not limited here, and can be one, two, three, etc., as long as it is sufficient to provide sufficient power for the cooling device. Preferably, two sets of delivery pumps 32 and motors 33 are provided.

[0039] like Figure 2As shown, when there are two or more delivery pumps 32, they are arranged in parallel. This allows the power provided by the delivery pumps 32 to be fully utilized to pressurize the coolant, saving power consumed by the motor 33 and avoiding waste. Furthermore, when inspecting the delivery module 3, the first shut-off valve 41 and the second shut-off valve 51 connected to the same delivery pump 32 can be closed each time, and different delivery pumps 32 can be inspected in sequence. This prevents the cooling device from stopping during the inspection and ensures the normal operation of the main helium blower.

[0040] like Figure 2 As shown, the cooling device of the nuclear power plant inverter also includes a liquid level gauge 6. The liquid level gauge 6 adopts the principle of a communicating vessel and is arranged on one side of the cooling water tank 1. The liquid level gauge 6 is connected to the cooling water tank 1 through a pipeline, so that the liquid level height of the liquid level gauge 6 and the liquid level in the cooling water tank 1 are the same, so as to facilitate the measurement of the liquid level of the coolant in the cooling water tank 1 and timely adjust the storage amount of the coolant to ensure the stable operation of the cooling device.

[0041] like Figure 2 As shown, a third shut-off valve 61 is provided at the top of the liquid level gauge 6, and a fourth shut-off valve 62 is provided at the bottom of the liquid level gauge 6; when the liquid level gauge 6 is in normal condition, the third shut-off valve 61 is in an open state, the fourth shut-off valve 62 is in a closed state, and the liquid level gauge 6 forms a communicating vessel with the cooling water tank 1.

[0042] It can be understood that when the cooling water tank 1 is replenished with coolant, the third shut-off valve 61 is in an open state and can be used to discharge the gas in the cooling water tank 1; when the cooling device is inspected and repaired, the third shut-off valve 61 and the fourth shut-off valve 62 can also be opened at the same time to flush the liquid level gauge 6.

[0043] In the description of the present invention, the term "plurality" refers to two or more than two. Unless otherwise expressly defined, the orientations or positional relationships indicated by the terms "upper" and "lower" are orientations or positional relationships based on the drawings and are intended only to facilitate the description of the present invention and simplify the description. They do not indicate or imply that the devices or components referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limitations on the present invention. The terms "connect," "install," and "fix" should all be understood in a broad sense. For example, "connection" can be a fixed connection, a detachable connection, or an integral connection; it can be a direct connection or an indirect connection through an intermediate medium. For those skilled in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0044] In the description of the present invention, the terms "one embodiment," "some embodiments," "specific embodiments," etc., mean that the specific features, structures, materials, or characteristics described in conjunction with that embodiment or example are included in at least one embodiment or example of the present invention. In the present invention, schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

[0045] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Those skilled in the art will readily appreciate that various modifications and variations of the present invention are possible. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present invention shall be included within the scope of protection of the present invention.

Claims

1. A cooling device for a frequency converter in a nuclear power plant, characterized in that: include: A cooling water tank (1), wherein an isolation device (12) is provided outside the cooling water tank (1), and the isolation device (12) comprises: A protective plate (13) is located on the side of the cooling water tank (1) and is used to isolate liquid leakage; A guide plate (14), the guide plate (14) being a funnel-shaped structure, is located below the cooling water tank (1), and a second liquid outlet (15) is provided at the lowest point of the guide plate (14), the second liquid outlet (15) being used to discharge leaked liquid; A working module (2) is arranged inside a frequency converter cabinet (21) of the frequency converter and is used to cool a frequency converter heat exchanger (22) of the frequency converter; A conveying module (3) is arranged inside a cooling cabinet (31), wherein the cooling cabinet (31) is located on one side below the cooling water tank (1), and the conveying module (3) is connected to the cooling water tank (1) and the working module (2). The conveying module (3) is used to convey the coolant in the cooling water tank (1) to the working module (2).

2. The cooling device for a nuclear power plant frequency converter according to claim 1, characterized in that: Also includes: A first liquid inlet pipe (4), a first liquid outlet (11) is provided at the bottom of the cooling water tank (1), and the first liquid inlet pipe (4) connects the first liquid outlet (11) and the inlet of the conveying module (3); A first liquid outlet pipe (5) is connected to the outlet of the delivery module (3) and the inlet of the working module (2); the outlet of the working module (2) is connected to the first liquid inlet pipe (4) for realizing the circulation of the cooling liquid.

3. The cooling device for a frequency converter of a nuclear power plant according to claim 2, characterized in that: Also includes: a first shut-off valve (41), the first shut-off valve (41) being provided on the first liquid inlet pipe (4) and located between the first liquid outlet (11) and the delivery module (3); A second shut-off valve (51), the second shut-off valve (51) is provided on the first liquid outlet pipe (5) and is located between the conveying module (3) and the working module (2).

4. The cooling device for a nuclear power plant frequency converter according to claim 1, characterized in that: The working module (2) includes a frequency converter heat exchanger (22).

5. The cooling device for a frequency converter of a nuclear power plant according to claim 1, characterized in that: The conveying module (3) comprises: a delivery pump (32) for pressurizing the coolant, wherein the number of the delivery pump (32) is at least one; A motor (33) is connected to the delivery pump (32), and the motor (33) is used to drive the delivery pump (32).

6. The cooling device for a frequency converter in a nuclear power plant according to claim 5, characterized in that: When the number of the delivery pumps (32) is two or more, the delivery pumps (32) are arranged in parallel.

7. The cooling device for a frequency converter of a nuclear power plant according to claim 1, characterized in that: Also includes: A liquid level meter (6) is connected to the cooling water tank (1), and the liquid level meter (6) is used to measure the liquid level in the cooling water tank (1).

8. The cooling device for a frequency converter in a nuclear power plant according to claim 7, characterized in that: A third shut-off valve (61) is provided on the top of the liquid level gauge (6); A fourth shut-off valve (62) is provided at the bottom of the liquid level gauge (6).

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