Pulse water flow adjusting device without rotating component, and nuclear power plant reactor cooling structure

Abstract

Provided in the present invention are a pulse water flow adjusting device without a rotating component, and a nuclear power plant reactor cooling structure. The pulse water flow adjusting device without the rotating component is configured to cool down a wall surface to be cooled, and during cooling, a pulse water flow is sprayed onto the wall surface to be cooled. The water flow adjusting device comprises a water container, a water output flow channel and a device inlet, wherein outside cooling water enters the water container through the device inlet; the water output flow channel has an inverted-U-shaped structure, and is provided with a water outlet and a flow channel inlet; the flow channel inlet is located in the water container; the water outlet penetrates the bottom of the water container, and guides the water flow onto the wall surface to be cooled; and the cross-sectional area of the water container is greater than that of the water output flow channel. Provided in the present invention is a method for reducing temperature by means of pulse water cooling. By using the method, the proportion of the evaporative heat exchange of a water film can be increased, and under the same heat exchange requirement, the required total water film flow is effectively reduced, thereby reducing the volume of a cooling water storage tank.

Description

Pulse water flow regulating device without rotating parts and nuclear power plant reactor cooling structure Technical Field

[0001] The present invention relates to the technical field of water flow cooling and temperature reduction, and in particular, to a pulsed water flow regulating device without rotating parts for water flow cooling and temperature reduction and a nuclear power plant reactor cooling structure. In particular, the present invention relates to a pulsed water flow regulating device without rotating parts and a nuclear power plant reactor cooling structure. Background Art

[0002] In the event of a coolant loss accident or main steam line rupture in a pressurized water reactor (PWR) nuclear power plant, the water vapor content in the inner containment vessel rapidly increases, leading to a significant increase in internal pressure and temperature. Once the pressure and temperature reach the set points at which the isolation valve at the bottom of the cooling water storage tank opens, cooling water flows by gravity from the cooling water storage tank at the top of the containment vessel, passes through a water film distribution device, and forms a uniformly distributed falling film on the containment vessel's outer wall. The water film's flow rate is controlled by the liquid level in the cooling water storage tank. As the water film flows along the containment vessel's outer wall, it undergoes significant surface evaporation heat transfer through convection with the air flow on its surface. Simultaneously, the water film's temperature continues to rise along the direction of flow, resulting in single-phase convection heat transfer. These two dominant heat transfer modes remove the accumulated heat within the containment vessel, maintaining the temperature and pressure within the containment vessel at safe levels.

[0003] Since the evaporation heat transfer efficiency of the water film is stronger than its single-phase countercurrent heat transfer efficiency, under the same heat transfer requirements, increasing the proportion of water film evaporation heat transfer in the total heat transfer will effectively reduce the required total water film flow rate and reduce the volume of the cooling water storage tank. Therefore, it is urgent to design a water flow regulating device that can increase the proportion of water film evaporation heat transfer.

[0004] Summary of the Invention

[0005] In view of the defects in the prior art, the purpose of the embodiments of the present invention is to provide a pulse water flow regulating device without rotating parts and a nuclear power plant reactor cooling structure.

[0006] According to an embodiment of the present invention, a pulse water flow regulating device without rotating parts is provided.

[0007] The water flow regulating device is used to cool the wall surface to be cooled, and during cooling, a pulsed water flow is poured onto the wall surface to be cooled;

[0008] The water flow regulating device includes a water container, a water outlet channel and a device inlet;

[0009] External cooling water enters the water container through the device inlet;

[0010] The water outlet channel has a water outlet and a channel inlet; the channel inlet is located in the water container, and the water outlet passes through the bottom of the water container to guide the water flow to the wall surface to be cooled;

[0011] The cross-sectional area of ​​the water container is larger than the cross-sectional area of ​​the water outlet channel.

[0012] Furthermore, the water outlet channel is an inverted U-shaped structure, and the water outlet and the channel inlet are respectively located at two ends of the inverted U-shaped structure.

[0013] Furthermore, the top of the water container, the arc-shaped top of the inverted U-shaped structure, the flow channel inlet and the water outlet are arranged from high to low in sequence.

[0014] Furthermore, the water flow rate at the device inlet is smaller than the water flow rate at the water outlet channel.

[0015] Furthermore, the number of the water outlet channel is one, and the cross-sectional area of ​​the device inlet is smaller than the cross-sectional area of ​​the water outlet channel.

[0016] Furthermore, there are multiple water outlet channels, and the cross-sectional area of ​​the device inlet is smaller than the sum of the cross-sectional areas of the multiple water outlet channels.

[0017] Furthermore, it also includes a cooling water storage tank, which is used to hold cooling water, and the cooling water enters the water container through the device inlet.

[0018] The present invention also provides a nuclear power plant reactor cooling structure including the pulse water flow regulating device without rotating parts. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Other features, objects and advantages of the present invention will become more apparent upon reading the detailed description of non-limiting embodiments with reference to the following drawings:

[0020] FIG1 is a schematic structural diagram of the present invention;

[0021] FIG2 is a schematic diagram showing the principle of the present invention;

[0022] The figure shows: DETAILED DESCRIPTION

[0023] The present invention will be described in detail below with reference to specific embodiments. The following examples will help those skilled in the art to further understand the present invention, but are not intended to limit the present invention in any form. It should be noted that, for those skilled in the art, several changes and improvements can be made without departing from the scope of the present invention. These all fall within the scope of protection of the present invention.

[0024] The present invention provides a pulse water flow regulating device without rotating parts, as shown in FIG1 , wherein the water flow regulating device is used to cool a high-temperature wall surface to be cooled. During the cooling process, a pulse water flow is poured onto the wall surface to be cooled.

[0025] The water flow regulating device includes a water container 1, a water outlet channel 3, and a device inlet 5. The water outlet channel 3 has a water outlet 2 and a channel inlet 4. The channel inlet 4 is located within the water container 1. The water outlet 2 passes through the bottom of the water container 1 and directs the water flow to the wall surface to be cooled. The cross-sectional area of ​​the water container 1 is larger than that of the water outlet channel 3. In a preferred embodiment, the device inlet 5 can be a pipe structure with or without a valve, located above the water container 1, or connected to the water container 1 through an opening in the side wall of the water container 1.

[0026] The water outlet channel 3 is an inverted U-shaped structure, with the water outlet 2 and channel inlet 4 located at either end of the inverted U-shaped structure. The top of the water container 1, the curved top 6 of the inverted U-shaped structure, the channel inlet 4, and the water outlet 2 are arranged in descending order.

[0027] The water flow rate at the device inlet 5 is smaller than the water flow rate at the water outlet channel 3. In a preferred embodiment, there is one water outlet channel 3, and the cross-sectional area of ​​the device inlet 5 is smaller than the cross-sectional area of ​​the water outlet channel 3. In another preferred embodiment, there are multiple water outlet channels 3, and the cross-sectional area of ​​the device inlet 5 is smaller than the sum of the cross-sectional areas of the multiple water outlet channels 3.

[0028] In a preferred example, the water flow regulating device further comprises a cooling water storage tank, which is used to contain cooling water, and the cooling water enters the water container 1 through the device inlet 5.

[0029] The working principle of the present invention is as follows:

[0030] When water is continuously injected into the water container 1 from upstream, the water level in the container starts to rise from the bottom. When the water level reaches the flow channel inlet 4, water will gradually flow into the side of the inverted U-shaped flow channel near the flow channel inlet 4, and its water level is consistent with the water level in the water container 1. However, since the liquid surface pressure in the inverted U-shaped flow channel and the liquid surface pressure in the external water container are both the ambient air pressure, the pressure is balanced and no water will flow out from the water outlet 2.

[0031] As shown in Figure 2, when the water level continues to rise and exceeds the arc-shaped top 6 of the inverted U-shaped flow channel (the upper limit water level, when it is higher than the upper limit water level, the water outlet 2 starts to discharge water), the water level in the water container 1 is higher than the water level in the inverted U-shaped water outlet channel 3. The pressure difference formed by this water level difference will drive the water in the water outlet channel 3 to flow out from the water outlet 2. Moreover, since the cross-section of the water container is larger than the cross-section of the inverted U-shaped flow channel, the liquid level in the water container 1 always drops slower than the liquid level in the inverted U-shaped flow channel (i.e., the water outlet channel 3). Therefore, the water level difference, i.e., the pressure difference, can always be maintained to ensure continuous water flow from the water outlet 2. At the same time, since the continuous water injection flow rate upstream is less than the flow rate of the water outlet 2 (i.e., the liquid water flow rate at the inlet 5 of the device is less than the water flow rate of the water outlet channel 3), it can also ensure that the water level in the water container 1 continues to drop when water injection from upstream is continuous.

[0032] Until the water level in the water container drops to the inlet 4 of the inverted U-shaped water outlet flow channel (the lower limit water level, below which the water outlet is cut off), the water flow at the water outlet 2 stops because no water can enter the inverted U-shaped flow channel.

[0033] At the same time, since the water flow from the upstream inlet (device inlet 5) continues, when the water outlet 2 stops flowing, the water level in the water container 1 starts to rise again, thus repeating the above process.

[0034] In summary, the present invention utilizes the pressure differential caused by water level fluctuations to achieve pulsed water flow. Without any rotating parts, the design is simpler and more reliable. The resulting pulsed water flow irrigates high-temperature surfaces, increasing the proportion of heat exchange through water film evaporation. Under the same heat exchange requirements, this effectively reduces the total required water film flow rate and the volume of the cooling water storage tank.

[0035] In the description of this application, it should be understood that the terms "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating the orientation or position relationship, are based on the orientation or position relationship shown in the accompanying drawings, and are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on this application.

[0036] Compared with the prior art, the present invention has the following beneficial effects:

[0037] 1. The present invention provides a pulse water cooling method, which can increase the proportion of water film evaporation heat exchange. Under the same heat exchange demand, it will effectively reduce the required total water film flow rate and reduce the volume of the cooling water storage tank.

[0038] 2. The present invention adopts the siphon principle and utilizes the change of water level in the water container to change the continuous water flow into a pulsed water flow. When the water film flow rate is 0, the surface temperature of the cooling wall will rise briefly, and then the water will flow down to take away the heat, and then the water flow will stop, and the cycle will repeat. In this mode, the higher wall temperature will increase the temperature of the water film, thereby leading to a higher water film evaporation rate, thereby achieving the purpose of increasing the proportion of water film evaporation heat exchange. Under the same heat exchange demand, the total water film flow rate required will be effectively reduced, and the volume of the cooling water storage tank will be reduced. The structure is reliable and easy to implement.

[0039] 3. The present invention can realize pulse water flow without external power drive and rotating structure, and has a simple structure, is reliable, energy-saving and environmentally friendly.

[0040] The above describes specific embodiments of the present invention. It should be understood that the present invention is not limited to the specific embodiments described above, and that those skilled in the art may make various changes or modifications within the scope of the claims without affecting the essence of the present invention. The embodiments of this application and the features of the embodiments may be combined in any manner unless there is a conflict.

Claims

1. A pulse water flow regulating device without rotating parts, characterized in that: The water flow regulating device is used to cool the wall surface to be cooled, and during cooling, a pulsed water flow is poured onto the wall surface to be cooled; The water flow regulating device comprises a water container (1), a water outlet channel (3) and a device inlet (5); External cooling water enters the water container (1) through the device inlet (5); The water outlet channel (3) comprises a water outlet (2) and a channel inlet (4); the channel inlet (4) is located in the water container (1), and the water outlet (2) passes through the bottom of the water container (1) to guide the water flow to the wall surface to be cooled; The cross-sectional area of ​​the water container (1) is greater than the cross-sectional area of ​​the water outlet channel (3).

2. The pulse water flow regulating device without rotating parts according to claim 1, characterized in that: The water outlet channel (3) is an inverted U-shaped structure, and the water outlet (2) and the channel inlet (4) are respectively located at two ends of the inverted U-shaped structure.

3. The pulse water flow regulating device without rotating parts according to claim 2, characterized in that: The top of the water container (1), the arc-shaped top (6) of the inverted U-shaped structure, the flow channel inlet (4) and the water outlet (2) are arranged in sequence from high to low.

4. The pulse water flow regulating device without rotating parts according to claim 1, characterized in that: The water flow rate at the device inlet (5) is smaller than the water flow rate at the water outlet channel (3).

5. The pulse water flow regulating device without rotating parts according to claim 1, characterized in that: The number of the water outlet channel (3) is one, and the cross-sectional area of ​​the device inlet (5) is smaller than the cross-sectional area of ​​the water outlet channel (3).

6. The pulse water flow regulating device without rotating parts according to claim 1, characterized in that: The number of the water outlet channels (3) is multiple, and the cross-sectional area of ​​the device inlet (5) is smaller than the sum of the cross-sectional areas of the multiple water outlet channels (3).

7. The pulse water flow regulating device without rotating parts according to claim 1, characterized in that: It also includes a cooling water storage tank, which is used to hold cooling water. The cooling water enters the water container (1) through the device inlet (5).

8. A nuclear power plant reactor cooling structure, characterized in that: A pulse water flow regulating device without rotating parts comprising any one of claims 1-7.

Images