An automatic pressure relief device and method based on acoustic and mechanical feedback mechanisms

Abstract

An automatic pressure relief device and method based on acoustic and mechanical feedback mechanism belong to the technical field of automatic pressure relief of pressure vessels. The present application solves the problem that the existing technology cannot maintain the stable condensation jet state of the sprayer. An isolation gate valve and an electric regulating valve are arranged in sequence on the pressure relief pipeline along the high-pressure steam conveying direction, a noise dosimeter is fixed on the upper side wall of the cooling pool, a pressure transmitter is installed in the cooling pool and each sprayer, and the noise dosimeter, the pressure transmitter and the electric regulating valve are electrically connected with the valve opening control module respectively; a plurality of spray holes are formed in the lower part of the sprayer along the circumferential direction, and each spray hole is a long hole formed along the height direction of the sprayer. The valve control logic based on acoustic and mechanical feedback mechanism and the sprayer spray hole design effectively weaken the dynamic load and intense noise of the sprayer, reduce the design size of the cooling pool, and improve the stability and safety of the automatic pressure relief device.

Description

Technical Field

[0001] This invention relates to an automatic pressure relief device and method based on acoustic and mechanical feedback mechanisms, belonging to the field of automatic pressure relief technology for pressure vessels. Background Technology

[0002] Automatic pressure relief devices are widely used in the energy and nuclear industries, petrochemical industries, and military industries. Under accident conditions, these devices guide high-temperature, high-pressure steam from pressure vessels to the final heat sink, completing the pressure relief process and ensuring equipment or system safety. During the discharge of steam into the subcooled water in the heat sink (water pool), steam jet condensation inevitably occurs. Various condensation flow patterns may appear during steam jet condensation, which can be broadly categorized into surge region, condensation oscillation region, and stable condensation region. In the surge zone, due to the low steam mass flow rate and high subcooling of the pool water, all the steam is condensed inside the nozzle, resulting in strong oscillations at the vapor-liquid interface and accompanied by loud noise. In the condensation oscillation zone, the vapor-liquid interface oscillates violently outside the nozzle, and periodic pressure oscillation signals can be measured, accompanied by loud noise. The stable condensation zone usually appears when the steam jet reaches its critical point, forming a stable jet plume at the nozzle. Compared to the other two flow patterns, the oscillation intensity of the stable jet is very weak, significantly smaller than the other two flow patterns. When the pool water temperature is high, the pool water condensation effect weakens, and the jet steam cannot be completely condensed, with some steam overflowing from the water surface. As the pool water temperature further rises to saturation, the steam will eventually be unable to condense, and the steam jet in the pool will transform into a "non-condensable" gas-immersed jet. If the jet velocity is high at this time, jet backlash will occur, causing strong pressure oscillations in the pool and also bringing a large impact load to the nozzle. After the automatic pressure relief device is started, as the pressure in the pressure vessel decreases and the temperature in the discharge pool increases, the pressure relief device will successively exhibit four phenomena: stable condensation jet, condensation oscillation, surge, and jet backlash. Except for stable condensation, the other jet flow patterns will generate strong pressure oscillations and severe noise, and may even cause resonance damage to the equipment or nearby system structures.

[0003] Currently, numerous types of automatic pressure relief systems have been designed in the market and research process. Most of these designs are based on system design, adjusting the pressure relief pipelines and system layout to create automatic pressure relief systems or dedicated safety facilities. However, these existing technologies still cannot maintain a stable condensation jet flow pattern in the sprayer, nor do they consider the structural design of the terminal sprayer and the potential threats that its jet flow pattern may pose to the equipment and system. Furthermore, existing nozzle designs cannot effectively cope with the impact of changes in upstream pressure and jet flow pattern. For example, complex jet states such as surge and condensation oscillation may occur during pressure relief, along with strong dynamic loads and severe noise generated under complex jet states.

[0004] Therefore, there is an urgent need for an automatic pressure relief device and method that can achieve a long-term stable condensation jet state of the sprayer and reduce the strong pressure oscillations generated by the jet. Summary of the Invention

[0005] The present invention aims to solve the above-mentioned technical problems and provides an automatic pressure relief device and method based on acoustic and mechanical feedback mechanisms.

[0006] The technical solution adopted by the present invention to solve the above-mentioned technical problems is as follows:

[0007] An automatic pressure relief device based on acoustic and mechanical feedback mechanisms includes a pressure vessel, a distribution manifold, a cooling water tank, a noise dosimeter, a pressure transmitter, a valve opening control module, and several sprayers. The outlet of the pressure vessel is connected to the inlet of the distribution manifold via a pressure relief pipeline. An isolation gate valve and an electric regulating valve are sequentially installed on the pressure relief pipeline along the high-pressure steam conveying direction. The sprayers are all installed in the cooling water tank and are connected to the outlets of the distribution manifold via pipelines. The noise dosimeter is fixed to the upper side wall of the cooling water tank. A pressure transmitter is installed in the cooling water tank and in each sprayer. The noise dosimeter, pressure transmitter, and electric regulating valve are electrically connected to the valve opening control module. Several spray holes are opened along the circumference of the lower part of the sprayer, and each spray hole is an elongated hole opened along the height direction of the sprayer.

[0008] Furthermore, several spray holes are distributed in multiple groups along the height direction of the sprayer, and each pair of adjacent groups of spray holes are arranged directly opposite each other in the height direction.

[0009] Furthermore, a slit auxiliary hole is provided between every two adjacent spray holes along the circumference of the sprayer.

[0010] Furthermore, each pair of adjacent slit auxiliary holes is arranged facing each other in the vertical direction.

[0011] Furthermore, each set of slit auxiliary holes is evenly distributed along the circumference of the sprayer.

[0012] Furthermore, the number of sprayers is three.

[0013] Furthermore, three sets of spray holes are arranged along the height direction of the sprayer.

[0014] Furthermore, the distribution manifold has a spherical structure.

[0015] Furthermore, each sprayer is equipped with at least one pressure transmitter, and the pressure transmitters in the cooling water tank are positioned close to the spray nozzles.

[0016] A depressurization method for the aforementioned automatic depressurization device includes the following steps: When depressurization is required, an isolation gate valve and an electric regulating valve are opened sequentially to discharge high-pressure steam from the pressure vessel into a cooling water pool through several sprayers. A valve opening control module detects the mechanical parameters of the spraying process collected by the pressure transmitter and the acoustic parameters collected by the noise dosimeter to determine whether the sprayer is in a stable condensing jet state. If so, the opening of the electric regulating valve is maintained; if not, the opening of the electric regulating valve is increased, and the valve opening control module continues to detect the mechanical parameters of the pressure transmitter and the acoustic parameters of the noise dosimeter to continue determining whether the sprayer is in a stable condensing jet state. This cycle continues until the sprayer is maintained in a stable condensing jet state.

[0017] Compared with the prior art, the present invention has the following advantages:

[0018] In this invention, by electrically connecting the noise dosimeter, pressure transmitter, and electric regulating valve to the valve opening control module, an automatic pressure relief device operation logic based on acoustic and mechanical feedback mechanism is established. The valve opening control module automatically adjusts the opening of the electric regulating valve by detecting the mechanical parameters of the pressure transmitter and the acoustic parameters of the noise dosimeter, so as to keep the sprayer in a long-term stable critical jet state.

[0019] In this invention, a distribution manifold is designed upstream of the sprayer, and the pressure is further distributed at the distribution manifold to make the flow distribution in each sprayer more uniform.

[0020] In this invention, the spray nozzle is designed as an elongated orifice and opened vertically. This nozzle shape can entrain ambient fluid in the free shear layer by the spanwise vortex caused by the Kelvin-Helmholtz instability, which enhances the mixing effect between the jet body and the ambient fluid during the steam immersion jet process and greatly weakens the intensity of condensation oscillation.

[0021] This invention, through its unique manifold structure design, makes the flow distribution within each sprayer more uniform. At the same time, the valve control logic based on acoustic and mechanical feedback mechanisms and the sprayer nozzle design effectively reduce the dynamic load and severe noise of the sprayers, reduce the design size of the cooling water tank, and improve the stability and safety of the automatic pressure relief device. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of the automatic pressure relief device based on acoustic and mechanical feedback mechanism of the present invention;

[0023] Figure 2 This is a front view schematic diagram of the sprayer;

[0024] Figure 3 for Figure 2Enlarged schematic diagram of point A (not proportional).

[0025] In the picture:

[0026] 1. Pressure vessel; 2. Distribution manifold; 3. Cooling water tank; 4. Noise dosimeter; 5. Pressure transmitter; 6. Valve opening control module; 7. Sprayer; 71. Spray hole; 72. Slit auxiliary hole; 8. Pressure relief pipeline; 9. Isolation gate valve; 10. Electric regulating valve. Detailed Implementation

[0027] Specific implementation method one: Combining Figures 1-3 This description aims to clearly and completely illustrate the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0028] It should be noted that the descriptions of "left," "right," "left side," "right side," "upper part," "lower part," "top," and "bottom" in this invention are defined based on the orientation or positional relationships shown in the accompanying drawings. They are merely for the convenience of describing the invention and for simplifying the description, and do not indicate or imply that the described structure must be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention. In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly specified.

[0029] In the description of this invention, unless otherwise expressly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal communication between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0030] An automatic pressure relief device based on acoustic and mechanical feedback mechanisms includes a pressure vessel 1, a distribution manifold 2, a cooling water tank 3, a noise dosimeter 4, a pressure transmitter 5, a valve opening control module 6, and several sprayers 7. The outlet of the pressure vessel 1 is connected to the inlet of the distribution manifold 2 via a pressure relief pipe 8. An isolation gate valve 9 and an electric regulating valve 10 are sequentially installed on the pressure relief pipe 8 along the high-pressure steam conveying direction. The several sprayers 7 are all installed in the cooling water tank 3 and are connected to several outlets of the distribution manifold 2 via pipelines. The noise dosimeter 4 is fixedly installed on the upper side wall of the cooling water tank 3. A pressure transmitter 5 is installed in the cooling water tank 3 and in each sprayer 7. The noise dosimeter 4, the pressure transmitter 5, and the electric regulating valve 10 are electrically connected to the valve opening control module 6. Several spray holes 71 are opened along the circumference of the lower part of the sprayer 7, and each spray hole 71 is an elongated hole opened along the height direction of the sprayer 7.

[0031] At least one pressure transmitter 5 is installed in each sprayer 7, and each pressure transmitter 5 in the cooling water tank 3 is positioned close to the spray hole 71. The pressure oscillation characteristics inside the sprayer 7 and the cooling water tank are measured using the pressure transmitters 5 installed in the sprayer 7 and the cooling water tank, respectively. Since strong pressure oscillations in the jet are often accompanied by severe noise, the signals from the noise dosimeter and the pressure transmitter complement each other to determine whether the jet is in a stable condensation jet stage.

[0032] When pressure relief is required, the isolation gate valve 9 and the electric regulating valve 10 are opened in sequence to discharge the high-pressure steam in the pressure vessel 1 into the cooling water pool 3 through several sprayers 7.

[0033] In this invention, by electrically connecting the noise dosimeter 4, pressure transmitter 5, and electric regulating valve 10 to the valve opening control module 6, an automatic pressure relief device operation logic based on acoustic and mechanical feedback mechanism is established. That is, the valve opening control module 6 automatically adjusts the opening of the electric regulating valve 10 by detecting the mechanical parameters of the pressure transmitter 5 and the acoustic parameters of the noise dosimeter 4, so as to keep the sprayer 7 in a long-term stable critical jet state.

[0034] In this invention, a distribution manifold 2 is designed upstream of the sprayer 7, and the flow distribution in each sprayer 7 is more uniform by performing secondary pressure distribution at the distribution manifold 2.

[0035] In this invention, the spray nozzle 71 of the sprayer 7 is designed as an elongated orifice and opened vertically. This nozzle 71 form can entrain ambient fluid in the free shear layer by the spanwise vortex caused by the Kelvin-Helmholtz instability, which enhances the mixing effect between the jet body and the ambient fluid during the steam immersion jet process, and greatly reduces the intensity of condensation oscillation and the possibility of jet backlash.

[0036] This invention, through a unique manifold structure design, achieves more uniform flow distribution within each sprayer 7. Simultaneously, the valve control logic based on acoustic and mechanical feedback mechanisms and the design of the sprayer orifices 71 effectively reduce the dynamic load and intense noise of the sprayer 7, decrease the design size of the cooling water tank 3, and improve the stability and safety of the automatic pressure relief device. Specifically, the mechanical parameters collected by each pressure transmitter 5 within the sprayer and cooling water tank are primarily used to determine whether the jet state of the sprayer 7 is in surge, condensation oscillation, or stable condensation jet. Once the back pressure of the sprayer orifice 71 is determined, the pressure required for the sprayer 7 to reach its critical state is also determined. When the pressure transmitter 5 detects low pressure, it sends an opening signal to the electric regulating valve 10, thereby increasing the pressure within the sprayer 7. When the noise dosimeter 4 and each pressure transmitter 5 detect strong noise and oscillations such as condensation oscillation, they also send an opening signal to the electric regulating valve 10. These two signals complement and back each other up, thereby controlling the valve opening degree and opening speed (mechanical and acoustic information databases can be established for various flow patterns to assist in flow pattern identification), and thus realizing the control logic of this valve.

[0037] Several nozzles 71 are distributed in multiple groups along the height direction of the sprayer 7, and each pair of adjacent vertical groups of nozzles 71 are arranged directly opposite each other in the height direction. This design, which arranges several long holes in a longitudinal manner and makes each long hole a vertical long hole, makes full use of the static pressure difference and Reyleigh-Taylor instability caused by different heights of the cooling water, breaks the gas-liquid interface between the jet steam body and the ambient fluid, enhances the mixing effect between the jet body and the ambient fluid, and further weakens the intensity of condensation oscillation.

[0038] A slit auxiliary hole 72 is provided between every two adjacent spray holes 71 along the circumference of the sprayer 7. This design, by incorporating the slit auxiliary holes 72 on both sides of the spray holes 71, utilizes the disturbance of the jet flow from the slit auxiliary holes 72 on the jet flow from the spray holes 71, which can, to some extent, reduce the jet backlash phenomenon that may occur when the cooling water pool 3 is saturated and the steam discharge is large. Furthermore, this effect is enhanced as the airflow through the slit auxiliary holes 72 increases, thus preventing the surface structure of the sprayer 7 from being subjected to strong impact loads induced by jet backlash.

[0039] Each pair of adjacent slit auxiliary holes 72 is arranged directly opposite each other in the vertical direction. This design further enhances the effect of weakening the backlash. When there is a requirement that the aspect ratio of the nozzle 71 should not be too large (too large a drag coefficient would limit the discharge flow), the slit auxiliary holes 72 will become the main means of weakening the backlash.

[0040] Each set of slit auxiliary holes 72 is evenly distributed around the circumference of the sprayer 7. This design can address the possibility of jet backlash occurring from each elongated hole.

[0041] There are three sprayers 7.

[0042] Three sets of spray holes 71 are arranged along the height direction of the sprayer 7.

[0043] The distribution manifold 2 has a spherical structure. This design allows for flow distribution of the fluid before it enters each branch pipe from the main pipe, improving the uniformity of flow within each branch pipe. Simultaneously, the spherical structure of the distribution manifold 2 also minimizes velocity spikes and ensures more even stress distribution at the corners where it connects to the branch pipes.

[0044] A depressurization method for the aforementioned automatic depressurization device includes the following steps: When depressurization is required, the isolation gate valve 9 and the electric regulating valve 10 are opened sequentially to discharge the high-pressure steam in the pressure vessel 1 into the cooling water pool 3 through several sprayers 7. The valve opening control module 6 detects the mechanical parameters of the spraying process of the sprayers 7 collected by the pressure transmitter 5 and the acoustic parameters collected by the noise dosimeter 4 to determine whether the sprayers 7 are in a stable condensing jet state (the noise dosimeter is mainly used for auxiliary judgment; if no stable jet occurs, and the pressure transmitter 5 in the sprayer detects strong pressure oscillations, it indicates that a surge phenomenon has occurred; if the pressure transmitter in the cooling water pool 3 detects strong pressure oscillations, it indicates that a condensing oscillation phenomenon has occurred; strong pressure oscillations are often accompanied by severe noise). The noise dosimeter can detect this noise signal, and ultimately, the pressure transmitter signal and noise signal in the cooling water tank are used to control and increase the opening of the electric regulating valve, thereby bringing the sprayer to a critical jet state. Further, surge may occur near the sprayer. The pressure transmitter 5 in the sprayer detects this mechanical signal and also increases the opening of the electric regulating valve, thus bringing the sprayer to a stable jet state. If this occurs, the opening of the electric regulating valve 10 is maintained; otherwise, the opening of the electric regulating valve 10 is increased, and the valve opening control module 6 continues to detect the mechanical parameters of the pressure transmitter 5 and the acoustic parameters of the noise dosimeter 4 to determine whether the sprayer 7 is in a stable condensing jet state. This cycle continues until a stable condensing jet state is maintained. After multiple cycles, the electric regulating valve is opened to its maximum, and the pressure sensor in the sprayer still detects strong pressure oscillations within the sprayer, indicating that the system is currently in a low-flow surge zone. The pressure in the pressure vessel has decreased to a controllable range, and further depressurization is not required. The isolation gate valve begins to close.

[0045] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. An automatic pressure relief device based on acoustic and mechanical feedback mechanisms, characterized in that: The system includes a pressure vessel (1), a distribution manifold (2), a cooling water tank (3), a noise dosimeter (4), a pressure transmitter (5), a valve opening control module (6), and several sprayers (7). The outlet of the pressure vessel (1) is connected to the inlet of the distribution manifold (2) via a pressure relief pipe (8). An isolation gate valve (9) and an electric regulating valve (10) are sequentially installed on the pressure relief pipe (8) along the high-pressure steam conveying direction. Several sprayers (7) are installed in the cooling water tank (3) and are connected to several outlets of the distribution manifold (2) via pipelines. The noise dosimeter (4) is fixed to the upper side wall of the cooling water tank (3). 3) A pressure transmitter (5) is installed inside the sprayer (7). The noise dosimeter (4), pressure transmitter (5) and electric regulating valve (10) are electrically connected to the valve opening control module (6). Several spray holes (71) are opened along the circumference of the lower part of the sprayer (7). Each spray hole (71) is an elongated hole opened along the height direction of the sprayer (7). Several spray holes (71) are distributed in multiple groups along the height direction of the sprayer (7). Each two adjacent groups of spray holes (71) are arranged opposite each other in the height direction. A slit auxiliary hole (72) is opened between each two adjacent spray holes (71) along the circumference of the sprayer (7).

2. The automatic pressure relief device based on acoustic and mechanical feedback mechanism according to claim 1, characterized in that: Each pair of adjacent slit auxiliary holes (72) are arranged facing each other in the height direction.

3. An automatic pressure relief device based on acoustic and mechanical feedback mechanism according to claim 1 or 2, characterized in that: Each set of slit auxiliary holes (72) is evenly distributed around the sprayer (7).

4. An automatic pressure relief device based on acoustic and mechanical feedback mechanism according to claim 1 or 2, characterized in that: The number of sprayers (7) is three.

5. The automatic pressure relief device based on acoustic and mechanical feedback mechanism according to claim 1, characterized in that: Three sets of spray holes (71) are arranged along the height direction of the sprayer (7).

6. The automatic pressure relief device based on acoustic and mechanical feedback mechanism according to claim 1, characterized in that: The distribution manifold (2) has a spherical structure.

7. The automatic pressure relief device based on acoustic and mechanical feedback mechanism according to claim 1, characterized in that: Each sprayer is equipped with at least one pressure transmitter, and the pressure transmitters in the cooling water tank are positioned close to the spray nozzle.

8. A method for depressurizing the automatic depressurization device according to any one of claims 1 to 7, characterized in that: The process includes the following steps: When depressurization is required, the isolation gate valve (9) and the electric regulating valve (10) are opened in sequence to discharge the high-pressure steam in the pressure vessel (1) into the cooling water pool (3) through several sprayers (7). The valve opening control module (6) detects the mechanical parameters of the spraying process of the sprayer (7) collected by the pressure transmitter (5) and the acoustic parameters collected by the noise dosimeter (4) to determine whether the sprayer (7) is in a stable condensing jet state. If so, the opening of the electric regulating valve (10) is maintained. If not, the opening of the electric regulating valve (10) is increased, and the valve opening control module (6) continues to detect the mechanical parameters of the pressure transmitter (5) and the acoustic parameters of the noise dosimeter (4) to determine whether the sprayer (7) is in a stable condensing jet state. This cycle continues until the sprayer (7) is kept in a stable condensing jet state.

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