Pressure building monitoring safety pressure relief gate valve

Abstract

The invention discloses a pressure building monitoring safety pressure relief gate valve, belongs to the technical field of gate valve monitoring, and solves the problems that the service life is limited when the pressure building phenomenon in a middle cavity of a double-gate-plate gate valve is solved in a mechanical structure mode, and the pressure in the middle cavity is too large or the pressure building phenomenon in the middle cavity continues to be too long. The problem that the automatic pressure relief device cannot be used due to the fact that the automatic pressure relief device exceeds the stress limit or the working fatigue limit of the automatic pressure relief device is solved. The pressurizing pipeline and the pressure relief pipeline are communicated with the middle cavity and the outlet end. When the system works, the double-gate-plate blocking gate valve and the middle cavity are closed, the electric control module controls the electromagnetic valve to enable the Y-shaped stop valve to be communicated with the pressurizing pipeline and pressurizes fluid in the middle cavity, the system judges the fluid type through pressure change, a model matching database is combined, the fluid type is confirmed and the pressure building time is pre-judged, and the electric control module controls the electromagnetic valve according to the pressure building time. The Y-shaped stop valve is communicated with the pressure relief pipeline in advance, pressure is relieved immediately when fluid expands, the service life of the valve rod and the gate frame is prolonged, and overload work is avoided.

Description

Technical Field

[0001] The present invention relates to the technical field of gate valve monitoring, and in particular to a pressure-holding monitoring safety pressure relief gate valve. Background Art

[0002] A gate valve is a valve widely used in industrial and civil piping systems. Its primary function is to shut off or connect fluids in a pipeline. Its structure is relatively simple, consisting of a valve body, bonnet, stem, seat, gate disc, and packing. Its operating principle is to rotate the stem, causing the gate disc to rise or fall, thereby enabling or disabling the flow. Gate valves offer advantages such as low fluid resistance, low opening and closing torque, excellent sealing performance, and unrestricted flow. However, gate valves are not suitable for applications requiring frequent opening and closing or flow regulation. In industry, gate valves are commonly used in the petroleum, chemical, and power industries to control the flow of liquids, gases, or steam.

[0003] Among gate valves, double-disc gate valves offer superior sealing performance. Double-disc gate valves are important fluid control devices widely used in industries such as petroleum, chemical, power, and pharmaceuticals. Their operating principle is that the valve stem drives two parallel gates up and down, opening and closing the valve. When closed, the double-disc gates, preloaded by springs, tightly fit against the valve seat, creating a double seal and effectively preventing leakage. This valve offers excellent sealing performance, strong flow capacity, and low opening and closing torque. Its compact structure makes it suitable for installation in limited spaces, and the large contact area between the gate and seat allows it to withstand higher pressures. Furthermore, double-disc gate valves offer strong corrosion resistance, safe and reliable operation, and a long service life.

[0004] However, due to the excellent sealing performance of double-disc gate valves, in actual use, if the temperatures of the front and rear fluid media are inconsistent, pressure buildup may occur in the central cavity of the double-disc gate valve. When the gate valve is closed, the high-temperature, high-pressure fluid (liquid or gas) is trapped in the central cavity. If the temperature of the upstream fluid rises, the fluid in the central cavity will also rise due to heat transfer, causing volume expansion and a sharp increase in pressure. Especially when the liquid vaporizes in the central cavity, the pressure can increase exponentially. This abnormal pressure increase places extreme stress on the pressure-bearing components and opening and closing parts of the gate valve, potentially leading to serious consequences such as valve stem breakage, gate disc frame fracture, and even motor burnout. To address this problem, a pressure relief hole is usually opened in the upstream or downstream sealing disc of the valve to maintain equilibrium between the central cavity pressure and the external pressure.

[0005] For example, the parallel double-disc gate valve automatic pressure relief structure and the parallel double-disc gate valve one-way automatic pressure relief structure with application number CN201320120175.7 have the following technical features: they include a valve body, two valve seats, and two gate plates. The valve seats are embedded in the valve body, and the valve body is equipped with gate plates that can be tightly attached to or separated from the valve seats under the driving force of the actuator. The two gate plates are placed parallel to each other, and are characterized in that: both gate plates are provided with front-to-back through-holes, and an automatic pressure relief device is installed in the discharge hole to automatically discharge excess pressure inside the valve cavity.

[0006] This technical solution utilizes bleed holes on the left and right (or front and back) gate discs, along with an automatic pressure relief device within the holes. When the valve is closed, the temperature-dependent pressure buildup within the valve cavity is automatically released through the holes. This maintains the internal pressure at a constant level, effectively preventing the valve from opening or even damaging due to elevated internal pressure, and extending its service life.

[0007] The advantage of this traditional method of solving the pressure relief problem in the middle cavity through mechanical structure settings is that it does not require the use of electrical components, has no selection requirements for the application scenarios of the gate valve, can be used directly, and is relatively quick and convenient. However, this type of mechanical structure method to solve the pressure holding phenomenon in the middle cavity of the double-disc gate valve has a certain life limit. That is, when the pressure in the middle cavity is too high, or the pressure holding phenomenon in the middle cavity lasts too long, it will cause the automatic pressure relief device to exceed its force limit or its working fatigue limit, causing the automatic pressure relief device to lose its due effectiveness, resulting in problems with the pressure relief of the double-disc gate valve, which in turn affects the service life of the entire gate valve.

[0008] Therefore, a pressure-holding monitoring safety pressure relief gate valve is proposed to solve or alleviate the above problems. Summary of the Invention

[0009] The purpose of the present invention is to solve the shortcomings of the prior art and to propose a pressure-holding monitoring safety pressure relief gate valve.

[0010] In order to achieve the above object, the present invention adopts the following technical solutions: A pressure-holding monitoring safety relief gate valve comprises a pressurizing pipeline and a pressure-relief pipeline connecting a central cavity and an outlet end, a Y-shaped stop valve connectable to the pressurizing pipeline and the pressure-relief pipeline, a central cavity acquisition module, an upstream temperature acquisition module, a data storage module, a pressure-holding estimation module, and an electronic control module; The middle cavity acquisition module acquires fluid parameters in the middle cavity and feeds them back to the pressure holding prediction module. The upstream temperature acquisition module acquires fluid temperature data in the pipe upstream of the gate valve and feeds it back to the pressure holding prediction module. The data storage module is used to store a comparison database and provide it to the pressure holding prediction module. The pressure holding prediction module is used to determine the type of fluid in the middle cavity based on the feedback data, simulate the dynamic pressure holding in the middle cavity, and output the time axis of pressure holding occurrence. The electronic control module is used to control the action of the Y-type stop valve, and whether the pressurization pipeline and the pressure relief pipeline are connected to the control Y-type stop valve; When the Y-type stop valve is connected to the pressurized pipeline, the Y-type stop valve is reversely connected, and the Y-type stop valve performs an on-off action or an air-inflating and pressurizing action according to the control of the electronic control module. When the Y-type stop valve is connected to the pressure relief pipeline, the Y-type stop valve is forwardly connected.

[0011] Preferably, it also includes a first three-way electrically controlled valve and a second three-way electrically controlled valve coupled to the electronic control module, the three ports of the first three-way electrically controlled valve being connected to the first air relief pipe, the first connecting pipe, and the first air intake pipe, respectively, the three ports of the second three-way electrically controlled valve being connected to the second air relief pipe, the second connecting pipe, and the second air intake pipe, respectively, the first air relief pipe being used to connect to the middle cavity, the first connecting pipe being connected to the inlet of the Y-type stop valve, the first air relief pipe being connected to a first one-way valve, the second connecting pipe being connected to the outlet of the Y-type stop valve, the second air intake pipe being connected to the middle cavity, the second air intake pipe being connected to a second one-way valve, the first air relief pipe, the first connecting pipe, the second connecting pipe, and the second air relief pipe forming a pressure relief pipeline, and the first air intake pipe, the first connecting pipe, the second connecting pipe, and the second air intake pipe forming a pressurization pipeline.

[0012] Preferably, the middle cavity acquisition module includes an optical fiber sensor, the probe of the optical fiber sensor is used to be arranged in the middle cavity, and the optical fiber sensor collects fluid parameters in the middle cavity and feeds back to the pressure holding estimation module.

[0013] Preferably, the upstream temperature acquisition module includes a thermocouple sensor, the probe of the thermocouple sensor is used to be set in the upstream pipeline of the gate valve, and the upstream temperature acquisition module collects the fluid temperature data in the upstream pipeline of the gate valve and feeds it back to the pressure holding estimation module.

[0014] Preferably, the pressure holding prediction module includes a processor, which is used to determine the type of fluid in the middle cavity according to feedback data, simulate the dynamic pressure holding in the middle cavity, and output the time axis of pressure holding occurrence.

[0015] Preferably, the pressure holding prediction module is used to determine the type of fluid in the middle cavity according to the feedback data, simulate the dynamic pressure holding in the middle cavity and output the time axis of pressure holding, including the following steps: obtaining the fluid pressure in the middle cavity; The electronic control module controls the pressurized pipeline to be connected to the Y-type stop valve, and the electronic control module controls the actuator of the Y-type stop valve to drive the valve core to move back and forth for 30 seconds, and the frequency of the valve core's reciprocating movement is 2-5 times / second, so that the Y-type stop valve pressurizes the fluid in the middle cavity through the pressurized pipeline; Obtaining the fluid pressure in the middle cavity again, and subtracting the newly obtained fluid pressure in the middle cavity from the previous fluid pressure in the middle cavity to obtain a pressure change difference; A pressure change threshold is set, and the pressure change difference is compared with the pressure change threshold. If the pressure change difference is greater than the pressure change threshold, the output result is that the fluid type in the middle cavity is gas; otherwise, the output result is that the fluid type in the middle cavity is liquid.

[0016] Preferably, the pressure holding prediction module is used to determine the type of fluid in the middle cavity according to the feedback data, simulate the dynamic pressure holding in the middle cavity and output the time axis of pressure holding, and further includes the following steps: Determine that the type of fluid in the middle cavity is gas; Get the fluid temperature T in the middle cavity gas , the fluid pressure in the middle cavity p gas , the refractive index n of the fluid in the cavity gas The above parameters are imported into the gas simulation matching model, and the gas simulation matching model is used to match the data in the gas database according to the fluid temperature T in the middle cavity. gas , the fluid pressure in the middle cavity p gas Simulate the conditions and output a set of simulated refractive index n i , the gas database includes several gas type groups, each of the gas type groups includes gas density, gas molar mass, and gas refractive index at normal temperature and pressure; Set the refractive index n after simulation i ≈ the refractive index n of the fluid in the cavity gas As a condition, traverse a set of simulated refractive index n i And make a judgment, output the corresponding gas type group, and determine the specific type of fluid in the middle cavity; Determine that the fluid type in the middle cavity is liquid; Get the fluid temperature T in the middle cavity liquid , the fluid pressure in the middle cavity p liqui , the refractive index n of the fluid in the cavity liqui The above parameters are imported into the liquid simulation matching model, and the liquid simulation matching model is used to match the data in the liquid database according to the fluid temperature T in the middle cavity. liquid , the fluid pressure in the middle cavity p liqui Simulate the conditions and output a set of simulated refractive index N i, the liquid database includes several liquid type groups, each of the liquid type groups includes liquid density, liquid molar mass, liquid refractive index at room temperature and pressure, thermal expansion coefficient, and compressibility coefficient; Set the refractive index N after simulation i ≈ the refractive index n of the fluid in the cavity liqui As a condition, traverse a set of simulated refractive index N i And make a judgment, output the corresponding liquid type group, and determine the specific type of the fluid in the middle cavity.

[0017] Preferably, the liquid simulation matching model includes ,in, is the refractive index of the liquid at room temperature and pressure, K is the Gladstone-Dyer constant, is the liquid density, β is the thermal expansion coefficient, is room temperature, α is the compression coefficient, is normal pressure, C is the temperature correction coefficient, usually 0.00045 per degree Celsius, and the gas simulation matching model includes ,in, is the refractive index of gas at room temperature and pressure.

[0018] Preferably, the pressure holding prediction module is used to determine the type of fluid in the middle cavity according to the feedback data, simulate the dynamic pressure holding in the middle cavity and output the time axis of pressure holding, and further includes the following steps: Determine that the type of fluid in the middle cavity is gas; Obtain fluid temperature data in the upstream pipeline , obtain the fluid temperature T in the middle cavity gas , the fluid pressure in the middle cavity p gas , set the double gate temperature , fluid temperature in the middle cavity T gas The above parameters are imported into the gas pressure holding model to estimate the change and end time of the fluid pressure in the middle cavity; Under the condition that the fluid pressure in the middle cavity is greater than 1.33 times the nominal pressure of the valve, the time axis of pressure holding is intercepted and output; Determine that the fluid type in the middle cavity is liquid; Obtain fluid temperature data in the upstream pipeline , obtain the fluid temperature T in the middle cavity liquid , the fluid pressure in the middle cavity p liqui , set the double gate temperature , fluid temperature in the middle cavity T gas , the inner wall temperature of the middle cavity The above parameters are imported into the liquid pressure holding model to estimate the change and end time of the fluid volume in the middle cavity; Under the condition that the pressure corresponding to the volume of the fluid in the middle cavity is greater than 1.33 times the nominal pressure of the valve, the time axis of pressure holding is intercepted and output.

[0019] Preferably, the gas pressure holding model includes ,in, is the specific heat capacity of the fluid in the middle cavity, is the number of moles of fluid in the cavity, V is the volume of the cavity, is the convection heat transfer coefficient between the fluid in the upstream pipe and the double gate, y is the contact area between the fluid in the upstream pipe and the double gate, w is the contact area between the double gate and the fluid in the middle cavity, is the thermal conductivity of the double gate, is the time constant of pressure change; The liquid pressure holding model includes ,in, is the vaporization end time, is the vaporization start time, is the vaporization time; Vaporization start time , Vaporization time ,in, is the specific heat capacity of the fluid in the middle cavity, is the boiling point of the fluid in the middle cavity, m is the mass of the fluid in the middle cavity, is the convection heat transfer coefficient between the fluid in the upstream pipe and the double gate, y is the contact area between the fluid in the upstream pipe and the double gate, w is the contact area between the double gate and the fluid in the middle cavity, is the latent heat of vaporization of the fluid in the cavity.

[0020] The present invention has the following beneficial effects: When the present invention is working, the double gates block the gate valve and the middle cavity is closed; after the electronic control module receives the closing instruction, it controls the solenoid valve to connect the Y-type stop valve with the pressurized pipeline, and the actuator drives the valve core to move to complete the pressurization of the fluid in the middle cavity; the system determines the type of fluid through pressure changes, and imports the model matching database in combination with temperature, pressure, and refractive index to confirm the type of fluid and predict the pressure holding time; the electronic control module controls the solenoid valve accordingly, connects the Y-type stop valve with the pressure relief pipeline in advance, ensures that the middle cavity is connected with the outlet end, and immediately relieves pressure when the fluid expands, thereby extending the service life of the valve stem and gate frame and avoiding overload. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for use in the embodiments. It should be understood that the following drawings only illustrate certain embodiments of the present invention and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other relevant drawings can be obtained based on these drawings without paying any creative work.

[0022] Figure 1 It is a structural schematic diagram of the present invention; Figure 2 for Figure 1 Enlarged view of point A in the middle; Figure 3 This is a structural block diagram of the middle cavity acquisition module, upstream temperature acquisition module, pressure holding estimation module, data storage module, and electronic control module in the present invention.

[0023] 1. Middle cavity acquisition module; 2. Upstream temperature acquisition module; 3. Pressure holding prediction module; 4. Electronic control module; 5. Data storage module; 6. Y-type stop valve; 7. First three-way solenoid valve; 701. First air bleed pipe; 702. First one-way valve; 703. First connecting pipe; 704. First air inlet pipe; 8. Second three-way solenoid valve; 801. Second air bleed pipe; 802. Second one-way valve; 803. Second connecting pipe; 804. Second air inlet pipe. DETAILED DESCRIPTION

[0024] To make the objectives, technical solutions, and advantages of the embodiments of the present invention more clear, the technical solutions of the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Generally, the components of the embodiments of the present invention described and shown in the drawings herein can be arranged and designed in various different configurations.

[0025] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the invention as claimed, but rather merely represents selected embodiments of the present invention. All other embodiments derived by persons of ordinary skill in the art based on the embodiments of the present invention without creative effort shall fall within the scope of protection of the present invention.

[0026] It should be noted that similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, it does not need to be further defined or explained in subsequent drawings.

[0027] In the description of the present invention, it should be understood that the terms "center", "up", "down", "left", "right", "vertical", "horizontal", "inside", "outside", etc., indicating the orientation or position relationship, are based on the orientation or position relationship shown in the accompanying drawings, or are the orientation or position relationship in which the product of the invention is usually placed when in use, or are the orientation or position relationship commonly understood by those skilled in the art. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or component referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0028] Furthermore, the terms “first,” “second,” “third,” etc., are merely used for distinguishing descriptions and are not to be understood as indicating or implying relative importance.

[0029] In the description of the present invention, it should also be noted that, unless otherwise expressly specified or limited, the terms "disposed," "installed," "connected," and "connected" should be understood in a broad sense. For example, they may refer to fixed connections, detachable connections, or integral connections; they may refer to mechanical connections or electrical connections; they may refer to direct connections or indirect connections through an intermediate medium; and they may refer to internal communication between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on the specific circumstances.

[0030] A pressure monitoring safety relief gate valve, such as Figure 1 As shown, it includes a pressurizing pipeline and a pressure relief pipeline connecting the middle cavity and the outlet end, a Y-type stop valve 6 that can be connected to the pressurizing pipeline and the pressure relief pipeline, a middle cavity acquisition module 1, an upstream temperature acquisition module 2, a data storage module 5, a pressure holding estimation module 3, and an electronic control module 4; like Figure 3 As shown, the middle cavity acquisition module 1 acquires the fluid parameters in the middle cavity and feeds them back to the pressure holding prediction module 3, the upstream temperature acquisition module 2 acquires the fluid temperature data in the upstream pipeline of the gate valve and feeds it back to the pressure holding prediction module 3, the data storage module 5 is used to store the comparison database and provide it to the pressure holding prediction module 3, the pressure holding prediction module 3 is used to determine the type of fluid in the middle cavity based on the feedback data, simulate the dynamic pressure holding in the middle cavity and output the time axis of the pressure holding occurrence, the electronic control module 4 is used to control the action of the Y-type stop valve 6, and whether the pressurization pipeline and the pressure relief pipeline are connected to the control Y-type stop valve 6; More specifically, The middle cavity acquisition module 1 includes an optical fiber sensor, the probe of the optical fiber sensor is used to be set in the middle cavity, the optical fiber sensor collects the fluid parameters in the middle cavity and feeds back to the pressure holding estimation module 3, the upstream temperature acquisition module 2 includes a thermocouple sensor, the probe of the thermocouple sensor is used to be set in the upstream pipeline of the gate valve, the upstream temperature acquisition module 2 collects the fluid temperature data in the upstream pipeline of the gate valve and feeds back to the pressure holding estimation module 3, the data storage module 5 includes a memory, the memory is used to store the comparison database and provide it to the pressure holding estimation module 3, the pressure holding estimation module 3 includes a processor, the processor is used to determine the type of fluid in the middle cavity according to the feedback data, simulate the dynamic pressure holding in the middle cavity and output the time axis of the pressure holding occurrence, and the electronic control module 4 includes a controller.

[0031] When the Y-type stop valve 6 is connected to the pressurized pipeline, the Y-type stop valve 6 is set to be reversely connected, and the Y-type stop valve 6 performs an on-off action or an air-inflating and pressurizing action according to the control of the electronic control module 4. When the Y-type stop valve 6 is connected to the pressure relief pipeline, the Y-type stop valve 6 is set to be forwardly connected.

[0032] Specifically, like Figure 1 and Figure 2 As shown, it also includes a first three-way electrically controlled valve and a second three-way electrically controlled valve coupled to the electronic control module 4. The three ports of the first three-way electrically controlled valve are respectively connected to the first air release pipe 701, the first connecting pipe 703, and the first air inlet pipe 704. The three ports of the second three-way electrically controlled valve are respectively connected to the second air release pipe 801, the second connecting pipe 803, and the second air inlet pipe 804. The first air release pipe 701 is used to communicate with the middle cavity, the first connecting pipe 703 is connected to the inlet of the Y-type stop valve 6, and the first air release pipe 801 is used to communicate with the middle cavity. The first connecting pipe 703 is connected to the inlet of the Y-type stop valve 6. The air pipe 701 is connected to a first one-way valve 702, the second connecting pipe 803 is connected to the outlet of the Y-type stop valve 6, the second air inlet pipe 804 is connected to the middle cavity, the second air inlet pipe 804 is connected to a second one-way valve 802, the first air relief pipe 701, the first connecting pipe 703, the second connecting pipe 803, and the second air relief pipe 801 form a pressure relief pipeline, and the first air inlet pipe 704, the first connecting pipe 703, the second connecting pipe 803, and the second air inlet pipe 804 form a pressurized pipeline.

[0033] Preferably, the pressure holding prediction module 3 is used to determine the type of fluid in the middle cavity according to the feedback data, simulate the dynamic pressure holding in the middle cavity and output the time axis of pressure holding, including the following steps: obtaining the fluid pressure in the middle cavity; The pressurized pipeline is controlled by the electronic control module 4 to be connected to the Y-type stop valve 6, and the actuator of the Y-type stop valve 6 is controlled by the electronic control module 4 to drive the valve core to move back and forth for 30 seconds, and the frequency of the valve core's reciprocating movement is 2-5 times / second, so that the Y-type stop valve 6 pressurizes the fluid in the middle cavity through the pressurized pipeline; Obtaining the fluid pressure in the middle cavity again, and subtracting the newly obtained fluid pressure in the middle cavity from the previous fluid pressure in the middle cavity to obtain a pressure change difference; A pressure change threshold is set, and the pressure change difference is compared with the pressure change threshold. If the pressure change difference is greater than the pressure change threshold, the output result is that the fluid type in the middle cavity is gas; otherwise, the output result is that the fluid type in the middle cavity is liquid.

[0034] Determine that the type of fluid in the middle cavity is gas; Get the fluid temperature T in the middle cavity gas , the fluid pressure in the middle cavity p gas , the refractive index n of the fluid in the cavity gas The above parameters are imported into the gas simulation matching model, and the gas simulation matching model is used to match the data in the gas database according to the fluid temperature T in the middle cavity. gas , the fluid pressure in the middle cavity p gas Simulate the conditions and output a set of simulated refractive index n i ,The gas database includes several gas type groups, each gas type group includes gas density, gas molar mass, and gas refractive index at normal temperature and pressure; Set the refractive index n after simulation i ≈ the refractive index n of the fluid in the cavity gas As a condition, traverse a set of simulated refractive index n i And make a judgment, output the corresponding gas type group, and determine the specific type of fluid in the middle cavity; Determine that the fluid type in the middle cavity is liquid; Get the fluid temperature T in the middle cavity liquid , the fluid pressure in the middle cavity p liqui , the refractive index n of the fluid in the cavity liqui The above parameters are imported into the liquid simulation matching model, and the liquid simulation matching model is used to match the data in the liquid database according to the fluid temperature T in the middle cavity. liquid , the fluid pressure in the middle cavity p liqui Simulate the conditions and output a set of simulated refractive index N i ,The liquid database includes several liquid type groups, each liquid type group includes liquid density, liquid molar mass, liquid refractive index at room temperature and pressure, thermal expansion coefficient, and compressibility; Set the refractive index N after simulation i ≈ the refractive index n of the fluid in the cavity liqui As a condition, traverse a set of simulated refractive index N i And make a judgment, output the corresponding liquid type group, and determine the specific type of the fluid in the middle cavity.

[0035] Liquid simulation matching models include ,in, is the refractive index of the liquid at room temperature and pressure, K is the Gladstone-Dyer constant, is the liquid density, β is the thermal expansion coefficient, is room temperature, α is the compression coefficient, is the atmospheric pressure, C is the temperature correction coefficient, usually 0.00045 per degree Celsius, and the gas simulation matching model includes ,in, is the refractive index of gas at room temperature and pressure.

[0036] Determine that the type of fluid in the middle cavity is gas; Obtain fluid temperature data in the upstream pipeline , obtain the fluid temperature T in the middle cavity gas , the fluid pressure in the middle cavity p gas , set the double gate temperature , fluid temperature in the middle cavity T gas The above parameters are imported into the gas pressure holding model to estimate the change and end time of the fluid pressure in the middle cavity; Under the condition that the fluid pressure in the middle cavity is greater than 1.33 times the nominal pressure of the valve, the time axis of pressure holding is intercepted and output; Determine that the fluid type in the middle cavity is liquid; Obtain fluid temperature data in the upstream pipeline , obtain the fluid temperature T in the middle cavity liquid , the fluid pressure in the middle cavity p liqui , set the double gate temperature , fluid temperature in the middle cavity T gas , the inner wall temperature of the middle cavity The above parameters are imported into the liquid pressure holding model to estimate the change and end time of the fluid volume in the middle cavity; Under the condition that the pressure corresponding to the volume of the fluid in the middle cavity is greater than 1.33 times the nominal pressure of the valve, the time axis of pressure holding is intercepted and output.

[0037] Among them, the gas pressure holding model includes ,in, is the specific heat capacity of the fluid in the middle cavity, is the number of moles of fluid in the cavity, V is the volume of the cavity, is the convection heat transfer coefficient between the fluid in the upstream pipe and the double gate, y is the contact area between the fluid in the upstream pipe and the double gate, w is the contact area between the double gate and the fluid in the middle cavity, is the thermal conductivity of the double gate, is the time constant of pressure change; Among them, the liquid pressure holding model includes ,in, is the vaporization end time, is the vaporization start time, is the vaporization time; Vaporization start time , Vaporization time ,in, is the specific heat capacity of the fluid in the middle cavity, is the boiling point of the fluid in the middle cavity, m is the mass of the fluid in the middle cavity, is the convection heat transfer coefficient between the fluid in the upstream pipe and the double gate, y is the contact area between the fluid in the upstream pipe and the double gate, w is the contact area between the double gate and the fluid in the middle cavity, is the latent heat of vaporization of the fluid in the cavity.

[0038] When the present invention is working, the double gate blocks the gate valve, and the middle cavity is closed at this time. After the electronic control module 4 receives the gate valve closing instruction, the electronic control module 4 controls the first three-way solenoid valve 7 and the second three-way solenoid valve 8, so that the Y-type stop valve 6 is connected to the pressurized pipeline at this time, and then the electronic control module 4 controls the actuator of the Y-type stop valve 6. The actuator of the Y-type stop valve 6 drives the valve core to move back and forth for 30 seconds, and the Y-type stop valve 6 completes the pressurization of the fluid in the middle cavity through the pressurized pipeline. At this time, it can be judged whether the fluid retained in the middle cavity is liquid or gas according to the pressure change in the middle cavity, and no matter when the gate valve is transporting any fluid, there is no need to input the type of fluid being transported. It can be judged by the system itself, and then the temperature, pressure and refractive index of the fluid in the middle cavity are introduced into the model. The database is matched with the data, and on the basis of determining the fluid type, the fluid type is further confirmed, and on this basis, the time process of the pressure holding phenomenon of the fluid is predicted to occur, namely, gas and liquid. After the time process is transmitted to the electronic control module 4, the electronic control module 4 can control the first three-way solenoid valve 7 and the second three-way solenoid valve 8, so that the Y-type stop valve 6 is connected to the pressure relief pipeline in advance, and the Y-type stop valve 6 is opened at the same time to ensure that the middle cavity is already connected to the outlet end of the valve body at this time. When the fluid in the middle cavity expands, the pressure relief action can be performed, and the valve stem and the gate frame will not be in the pressure holding environment of the middle cavity, which greatly extends their service life. In addition, the pressure relief action is performed at the first time of fluid expansion, and the pressure will not be released under high pressure, which avoids long-term overload of a series of pressure relief structures and shortening of service life.

[0039] The foregoing description is merely a preferred embodiment of the present invention and is 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 are intended to be within the scope of protection of the present invention.

Claims

1. A pressure-holding monitoring safety relief gate valve, characterized in that: It includes a pressurizing pipeline and a pressure relief pipeline connecting the middle cavity and the outlet end, a Y-type stop valve (6) that can be connected to the pressurizing pipeline and the pressure relief pipeline, a middle cavity acquisition module (1), an upstream temperature acquisition module (2), a data storage module (5), a pressure holding estimation module (3), and an electronic control module (4); The middle cavity acquisition module (1) acquires fluid parameters in the middle cavity and feeds them back to the pressure holding prediction module (3); the upstream temperature acquisition module (2) acquires fluid temperature data in the upstream pipeline of the gate valve and feeds them back to the pressure holding prediction module (3); the data storage module (5) is used to store a comparison database and provide it to the pressure holding prediction module (3); the pressure holding prediction module (3) is used to determine the type of fluid in the middle cavity based on the feedback data, simulate the dynamic pressure holding in the middle cavity and output the time axis of pressure holding occurrence; the electric control module (4) is used to control the action of the Y-type stop valve (6), and whether the pressurization pipeline and the pressure relief pipeline are connected to the control Y-type stop valve (6); When the Y-type stop valve (6) is connected to the pressurized pipeline, the Y-type stop valve (6) is reversely connected, and the Y-type stop valve (6) performs an on-off action or an air-inflating and pressurizing action according to the control of the electronic control module (4). When the Y-type stop valve (6) is connected to the pressure relief pipeline, the Y-type stop valve (6) is forwardly connected.

2. A pressure-holding monitoring safety relief gate valve according to claim 1, characterized in that: The invention also includes a first three-way electrically controlled valve and a second three-way electrically controlled valve coupled to the electric control module (4), wherein the three ports of the first three-way electrically controlled valve are respectively connected to the first air release pipe (701), the first connecting pipe (703), and the first air inlet pipe (704), and the three ports of the second three-way electrically controlled valve are respectively connected to the second air release pipe (801), the second connecting pipe (803), and the second air inlet pipe (804), wherein the first air release pipe (701) is used to connect to the middle cavity, the first connecting pipe (703) is connected to the inlet of the Y-type stop valve (6), and ... and the first air release pipe (701) is used to connect to the middle cavity. ) is connected to a first one-way valve (702), the second connecting pipe (803) is connected to the outlet of the Y-type stop valve (6), the second air inlet pipe (804) is connected to the middle cavity, the second air inlet pipe (804) is connected to a second one-way valve (802), the first air relief pipe (701), the first connecting pipe (703), the second connecting pipe (803), and the second air relief pipe (801) form a pressure relief pipeline, and the first air inlet pipe (704), the first connecting pipe (703), the second connecting pipe (803), and the second air inlet pipe (804) form a pressurization pipeline.

3. The pressure-holding monitoring safety relief gate valve according to claim 1 is characterized in that: The middle cavity acquisition module (1) comprises an optical fiber sensor, the probe of which is arranged in the middle cavity, and the optical fiber sensor acquires fluid parameters in the middle cavity and feeds back the parameters to the pressure holding estimation module (3).

4. The pressure-holding monitoring safety relief gate valve according to claim 1 is characterized in that: The upstream temperature acquisition module (2) comprises a thermocouple sensor, the probe of which is arranged in the upstream pipeline of the gate valve. The upstream temperature acquisition module (2) collects fluid temperature data in the upstream pipeline of the gate valve and feeds it back to the pressure holding estimation module (3).

5. The pressure-holding monitoring safety relief gate valve according to claim 1 is characterized in that: The pressure holding prediction module (3) comprises a processor, which is used to determine the type of fluid in the middle cavity according to feedback data, simulate the dynamic pressure holding in the middle cavity, and output the time axis of pressure holding occurrence.

6. The pressure-holding monitoring safety relief gate valve according to claim 1 is characterized in that: The pressure holding prediction module (3) is used to determine the type of fluid in the middle cavity based on the feedback data, simulate the dynamic pressure holding in the middle cavity and output the time axis of pressure holding, including the following steps: obtaining the fluid pressure in the middle cavity; The pressurized pipeline is controlled by the electronic control module (4) to be connected to the Y-type stop valve (6), and the actuator of the Y-type stop valve (6) is controlled by the electronic control module (4) to drive the valve core to move back and forth for 30 seconds, and the frequency of the back and forth movement of the valve core is 2-5 times / second, so that the Y-type stop valve (6) pressurizes the fluid in the middle cavity through the pressurized pipeline; Obtaining the fluid pressure in the middle cavity again, and subtracting the newly obtained fluid pressure in the middle cavity from the previous fluid pressure in the middle cavity to obtain a pressure change difference; A pressure change threshold is set, and the pressure change difference is compared with the pressure change threshold. If the pressure change difference is greater than the pressure change threshold, the output result is that the fluid type in the middle cavity is gas; otherwise, the output result is that the fluid type in the middle cavity is liquid.

7. The pressure-holding monitoring safety relief gate valve according to claim 6, characterized in that: The pressure holding prediction module (3) is used to determine the type of fluid in the middle cavity based on the feedback data, simulate the dynamic pressure holding in the middle cavity and output the time axis of pressure holding, and also includes the following steps: Determine that the type of fluid in the middle cavity is gas; Get the fluid temperature T in the middle cavity gas , the fluid pressure in the middle cavity p gas , the refractive index n of the fluid in the cavity gas The above parameters are imported into the gas simulation matching model, and the gas simulation matching model is used to match the data in the gas database according to the fluid temperature T in the middle cavity. gas , the fluid pressure in the middle cavity p gas Simulate the conditions and output a set of simulated refractive index n i , the gas database includes several gas type groups, each of the gas type groups includes gas density, gas molar mass, and gas refractive index at normal temperature and pressure; Set the refractive index n after simulation i ≈ the refractive index n of the fluid in the cavity gas As a condition, traverse a set of simulated refractive index n i And make a judgment, output the corresponding gas type group, and determine the specific type of fluid in the middle cavity; Determine that the fluid type in the middle cavity is liquid; Get the fluid temperature T in the middle cavity liquid , the fluid pressure in the middle cavity p liqui , the refractive index n of the fluid in the cavity liqui The above parameters are imported into the liquid simulation matching model, and the liquid simulation matching model is used to match the data in the liquid database according to the fluid temperature T in the middle cavity. liquid , the fluid pressure in the middle cavity p liqui Simulate the conditions and output a set of simulated refractive index N i , the liquid database includes several liquid type groups, each of the liquid type groups includes liquid density, liquid molar mass, liquid refractive index at room temperature and pressure, thermal expansion coefficient, and compressibility coefficient; Set the refractive index N after simulation i ≈ the refractive index n of the fluid in the cavity liqui As a condition, traverse a set of simulated refractive index N i And make a judgment, output the corresponding liquid type group, and determine the specific type of the fluid in the middle cavity.

8. The pressure-holding monitoring safety relief gate valve according to claim 7, characterized in that: The liquid simulation matching model includes ,in, is the refractive index of the liquid at room temperature and pressure, K is the Gladstone-Dyer constant, is the liquid density, β is the thermal expansion coefficient, is room temperature, α is the compression coefficient, is normal pressure, C is the temperature correction coefficient, usually 0.00045 per degree Celsius, and the gas simulation matching model includes ,in, is the refractive index of gas at room temperature and pressure.

9. The pressure-holding monitoring safety relief gate valve according to claim 8, characterized in that: The pressure holding prediction module (3) is used to determine the type of fluid in the middle cavity based on the feedback data, simulate the dynamic pressure holding in the middle cavity and output the time axis of pressure holding, and also includes the following steps: Determine that the type of fluid in the middle cavity is gas; Obtain fluid temperature data in the upstream pipeline , obtain the fluid temperature T in the middle cavity gas , the fluid pressure in the middle cavity p gas , set the double gate temperature , fluid temperature in the middle cavity T gas The above parameters are imported into the gas pressure holding model to estimate the change and end time of the fluid pressure in the middle cavity; Under the condition that the fluid pressure in the middle cavity is greater than 1.33 times the nominal pressure of the valve, the time axis of pressure holding is intercepted and output; Determine that the fluid type in the middle cavity is liquid; Obtain fluid temperature data in the upstream pipeline , obtain the fluid temperature T in the middle cavity liquid , the fluid pressure in the middle cavity p liqui , set the double gate temperature , fluid temperature in the middle cavity T gas , the inner wall temperature of the middle cavity The above parameters are imported into the liquid pressure holding model to estimate the change and end time of the fluid volume in the middle cavity; Under the condition that the pressure corresponding to the volume of the fluid in the middle cavity is greater than 1.33 times the nominal pressure of the valve, the time axis of pressure holding is intercepted and output.

10. The pressure-holding monitoring safety relief gate valve according to claim 9, characterized in that: The gas pressure holding model includes ,in, is the specific heat capacity of the fluid in the middle cavity, is the number of moles of fluid in the cavity, V is the volume of the cavity, is the convection heat transfer coefficient between the fluid in the upstream pipe and the double gate, y is the contact area between the fluid in the upstream pipe and the double gate, w is the contact area between the double gate and the fluid in the middle cavity, is the thermal conductivity of the double gate, is the time constant of pressure change; The liquid pressure holding model includes ,in, is the vaporization end time, is the vaporization start time, is the vaporization time; Vaporization start time , Vaporization time ,in, is the specific heat capacity of the fluid in the middle cavity, is the boiling point of the fluid in the middle cavity, m is the mass of the fluid in the middle cavity, is the convection heat transfer coefficient between the fluid in the upstream pipe and the double gate, y is the contact area between the fluid in the upstream pipe and the double gate, w is the contact area between the double gate and the fluid in the middle cavity, is the latent heat of vaporization of the fluid in the cavity.

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