Method and device for determining net positive suction head warning value and method and system for monitoring net positive suction state

Abstract

The invention discloses a method and a device for determining a net positive suction head warning value and a method and a system for monitoring a cavitation state, and relates to the technical field of polycrystalline silicon production. The method for determining the net positive suction head warning value comprises the steps that net positive suction head NPSHa and first area information of a circulating pump are obtained, and the net positive suction head NPSHa is determined according to second area information; the first area information comprises a safety margin S and a necessary net positive suction head NPSHr; the second area information comprises a container discharging temperature real-time value, a dichlorosilane component content real-time value, a trichlorosilane component content real-time value and a silicon tetrachloride content real-time value; and according to the net positive suction head NPSHa and the first area information, the net positive suction head warning value NPSH of the circulating pump is determined. According to the embodiment of the invention, the method can achieve the real-time monitoring of the cavitation state.

Description

Technical Field

[0001] This application belongs to the technical field of polysilicon production, and specifically relates to a method and device for determining the cavitation margin warning value, and a method and system for monitoring the cavitation state. Background Art

[0002] Pumps are key equipment in chemical enterprises, which are directly related to the safe and stable operation of on-site process conditions. Especially in the technical field of polysilicon production, in the rectification process, there is a situation of gas-liquid two-phase flow, and in this case, cavitation is likely to occur. Therefore, it is necessary to monitor the cavitation state of the circulating pump in real time.

[0003] In the related art, usually through a series of large models, the uncertainty of interference variables affecting cavitation is quantified and then cavitation is analyzed. However, due to offline simulation and the use of large models, this solution cannot achieve real-time monitoring of the cavitation margin of the circulating pump, and is only used for fault analysis. Therefore, there is an urgent need for a method that can monitor the cavitation margin of the circulating pump in real time. Summary of the Invention

[0004] The technical problem to be solved by this application is to provide a method and device for determining the cavitation margin warning value, and a method and system for monitoring the cavitation state in view of the above deficiencies existing in the prior art. Using the method for determining the cavitation margin warning value, real-time monitoring of the cavitation state can be achieved.

[0005] In a first aspect, an embodiment of this application provides a method for determining the cavitation margin warning value, which is applied to a circulating pump in a polysilicon production process. The method includes:

[0006] Obtain the cavitation margin NPSHa of the circulating pump and the first region information, and the cavitation margin NPSHa is determined according to the second region information; the first region information includes the safety margin S and the required cavitation margin NPSHr; the second region information includes the real-time value of the container discharge temperature, the real-time value of the dichlorosilane component content, the real-time value of the trichlorosilane component content, and the real-time value of the silicon tetrachloride content;

[0007] Determine the cavitation margin warning value NPSH of the circulating pump according to the cavitation margin NPSHa and the first region information.

[0008] In some embodiments of the first aspect, obtaining the cavitation margin NPSHa of the circulating pump specifically includes:

[0009] Obtain the target bubble point pressure of the circulating pump at different temperatures; the target bubble point pressure is the bubble point pressure of any two of dichlorosilane, trichlorosilane, and silicon tetrachloride;

[0010] Determine the saturated vapor pressure Pv according to the target bubble point pressure;

[0011] Determine the net positive suction head available (NPSHa) of the circulation pump according to the saturated vapor pressure Pv.

[0012] In some embodiments of the first aspect, obtaining the target bubble point pressure of the circulation pump at different temperatures specifically includes:

[0013] Obtain the target bubble point pressure of the circulation pump at different temperatures through simulation software.

[0014] In some embodiments of the first aspect, determining the net positive suction head available (NPSHa) of the circulation pump according to the saturated vapor pressure Pv specifically includes:

[0015] Obtain the local atmospheric pressure P0, gravitational acceleration g, the discharge pressure P of the circulation pump vs , the real-time value of the material density ρ, the resistance drop H of the inlet pipeline ls , the height H1 from the zero point of the container liquid level to the pump inlet and the real-time value of the container liquid level H2;

[0016] According to the local atmospheric pressure P0, gravitational acceleration g, discharge pressure P vs , the real-time value of the material density ρ, the resistance drop H of the inlet pipeline ls , the height H1 from the zero point of the container liquid level to the pump inlet, the real-time value of the container liquid level H2 and the saturated vapor pressure Pv, determine the net positive suction head available (NPSHa) of the circulation pump.

[0017] In some embodiments of the first aspect, the net positive suction head available (NPSHa) satisfies formula (1); formula (1) includes:

[0018] NPSHa = (P vs + P0 / 1000 - Pv) × 100000 / ρg + H1 + H2 - H ls (1).

[0019] In some embodiments of the first aspect, obtaining the resistance drop H of the inlet pipeline of the circulation pump ls , specifically includes:

[0020] Obtain the gravitational acceleration g, the real-time value of the friction pressure drop P of the circulation pump mo , the relative density of the material γ and all other pressure drops; all other pressure drops include all pressure drops except the initial value of the control valve pressure drop, heat exchanger pressure drop, reactor pressure drop, filter pressure drop, orifice plate pressure drop, other pressure drops and variable pipeline pressure drops;

[0021] Substitute the gravitational acceleration g, the real-time value of the friction pressure drop P mo , the relative density of the material γ and all other pressure drops into formula (2), and calculate to obtain the resistance drop H of the inlet pipeline ls ;

[0022] Formula (2) includes:

[0023] H ls = (P mo + all other pressure drops) / g / γ (2).

[0024] In some embodiments of the first aspect, obtaining the real-time value P of the frictional pressure drop of the circulation pump mo , specifically includes:

[0025] Obtaining the equivalent length Le of the circulation pump, the real-time value λ of the friction coefficient, the flow rate Q, the real-time value ρ of the material density, the third region information, and the fluid velocity Vs. The third region information includes the total number of different-diameter pipes and pipe orifices, and the pipeline length L;

[0026] Substituting the equivalent length Le, the real-time value λ of the friction coefficient, the flow rate Q, the real-time value ρ of the material density, the third region information, and the fluid velocity Vs into formula (3) to calculate the real-time value P of the frictional pressure drop of the circulation pump mo ;

[0027] Formula (3) includes:

[0028] P mo = (λ(Le + L) / D + the total number of different-diameter pipes and pipe orifices) * Vs 2 * ρ / 2 (3).

[0029] In some embodiments of the first aspect, obtaining the equivalent length Le of the circulation pump, specifically includes:

[0030] Obtaining the pipe diameter D of the circulation pump and the fourth region information. The fourth region information includes the pipe diameter, the number of 90-degree elbows, the number of 45-degree elbows, the number of straight-through tees, the number of side-out tees, the total number of valves, the number of globe valves, the number of check valves, the number of butterfly valves, the number of angle valves, and the number of different-diameter pipes; the total number of valves is the sum of the number of gate valves, the number of ball valves, and the number of plug valves;

[0031] Substituting the fourth region information into formula (4) to calculate the equivalent length Le of the circulation pump;

[0032] Formula (4) includes:

[0033] Le = D / 1000 × (35 × the number of 90-degree elbows + 16 × the number of 45-degree elbows + 20 × the number of straight-through tees + 60 × the number of side-out tees + 40 × the total number of valves + 300 × the number of globe valves + 200 × the number of check valves + 40 × the number of butterfly valves + 145 × the number of angle valves + 10 × the number of different-diameter pipes) (4).

[0034] In some embodiments of the first aspect, obtaining the real-time value ρ of the material density of the circulation pump, specifically includes:

[0035] Obtaining the real-time value of the container feed temperature of the circulation pump and the second region information;

[0036] Determine the real-time value ρ of the material density of the circulating pump according to the real-time value of the container feed temperature and the second region information.

[0037] In some embodiments of the first aspect, the net positive suction head warning value NPSH satisfies formula (5), and formula (5) includes:

[0038] NPSH = NPSHa - NPSHr - S (5).

[0039] Based on the same inventive concept, in a second aspect, an embodiment of the present application further provides a cavitation state monitoring method, which is applied to a circulating pump in a polysilicon production process. The method includes:

[0040] Determine the net positive suction head warning value NPSH of the circulating pump according to the net positive suction head warning value determination method of any item in the first aspect;

[0041] Visually display the net positive suction head warning value NPSH to realize the monitoring of the cavitation state.

[0042] Based on the same inventive concept, in a third aspect, an embodiment of the present application provides a net positive suction head warning value determination device, which is applied to a circulating pump in a polysilicon production process. The device includes:

[0043] A first acquisition module, configured to acquire the net positive suction head NPSHa of the circulating pump and the first region information, where the net positive suction head NPSHa is determined according to the second region information; the first region information includes a safety margin S and a required net positive suction head NPSHr; the second region information includes the real-time value of the container discharge temperature, the real-time value of the dichlorosilane component content, the real-time value of the trichlorosilane component content, and the real-time value of the silicon tetrachloride content;

[0044] A first determination module, connected to the first acquisition module, for determining the net positive suction head warning value NPSH of the circulating pump according to the net positive suction head NPSHa and the first region information.

[0045] In some embodiments of the third aspect, the first acquisition module is specifically configured to:

[0046] Acquire the target bubble point pressure of the circulating pump at different temperatures; the target bubble point pressure is the bubble point pressure of any two of dichlorosilane, trichlorosilane, and silicon tetrachloride;

[0047] Determine the saturated vapor pressure Pv according to the target bubble point pressure;

[0048] Determine the net positive suction head NPSHa of the circulating pump according to the saturated vapor pressure Pv.

[0049] In some embodiments of the third aspect, the first acquisition module is specifically configured to:

[0050] Obtain the target bubble point pressure of the circulating pump at different temperatures through simulation software.

[0051] In some embodiments of the third aspect, the first acquisition module is specifically configured to:

[0052] Obtain the local atmospheric pressure P0, gravitational acceleration g, the discharge pressure P of the circulating pump vs , the real-time value ρ of the material density, the inlet pipeline resistance drop H ls , the height H1 from the zero point of the container liquid level to the pump inlet and the real-time value H2 of the container liquid level;

[0053] According to the local atmospheric pressure P0, gravitational acceleration g, discharge pressure P vs , the real-time value ρ of the material density, the inlet pipeline resistance drop H ls , the height H1 from the zero point of the container liquid level to the pump inlet, the real-time value H2 of the container liquid level and the saturated vapor pressure Pv, determine the net positive suction head available NPSHa of the circulating pump.

[0054] Based on the same inventive concept, in the fourth aspect, an embodiment of the present application further provides a cavitation state monitoring system applied to the circulating pump in the polysilicon production process. The system includes:

[0055] The net positive suction head warning value determination device according to any one of the third aspect, which is used to determine the net positive suction head warning value NPSH of the circulating pump;

[0056] A display device, connected to the net positive suction head warning value determination device, which is used to visually display the net positive suction head warning value NPSH to realize the monitoring of the cavitation state.

[0057] According to the net positive suction head warning value determination method and device, cavitation state monitoring method and system provided by the embodiments of the present application, first obtain the net positive suction head available NPSHa of the circulating pump and the first area information, and then determine the net positive suction head warning value NPSH of the circulating pump according to the net positive suction head available NPSHa and the first area information; wherein, the net positive suction head available NPSHa is determined according to the second area information, and the first area information includes a safety margin S and a required net positive suction head NPSHr. That is to say, the embodiments of the present application obtain the real-time value of the container discharge temperature, the real-time value of the dichlorosilane component content, the real-time value of the trichlorosilane component content and the real-time value of the silicon tetrachloride content by real-time detecting the material component content and the container discharge temperature of the circulating pump, that is, by real-time obtaining the parameters related to the net positive suction head available of the circulating pump, and then determining the net positive suction head warning value NPSH of the circulating pump accordingly, which can realize the real-time monitoring of the circulating pump. Description of the Drawings

[0058] Figure 1 A flowchart showing a method for determining the net positive suction head warning value provided by an embodiment of the present application;

[0059] Figure 2 A schematic diagram showing a gas-phase STC scatter plot presented by the core database with an attached modeling backend according to an embodiment of the present application;

[0060] Figure 3 A schematic diagram showing the formula integration function presented by the core database with an attached modeling backend according to an embodiment of the present application;

[0061] Figure 3a Showing Figure 3 An enlarged schematic diagram of area A in

[0062] Figure 3b Showing Figure 3 An enlarged schematic diagram of area B in

[0063] Figure 4 A real-time monitoring UI screen for the cavitation state of pump 0501_P0330 with front-end integration attached to the core database according to an embodiment of the present application;

[0064] Figure 4a Showing Figure 4 An enlarged schematic diagram of area C in

[0065] Figure 4b Showing Figure 4 An enlarged schematic diagram of area D in

[0066] Figure 4c Showing Figure 4 An enlarged schematic diagram of area E in

[0067] Figure 5 A schematic diagram showing the structure of a device for determining the cavitation margin warning value according to an embodiment of the present application;

[0068] Figure 6 A schematic diagram showing the structure of a device for monitoring the cavitation state according to an embodiment of the present application;

[0069] Figure 7 A schematic diagram showing the structure of a system for monitoring the cavitation state according to an embodiment of the present application. Detailed implementation manners

[0070] To enable those skilled in the art to better understand the technical solutions of the present application, the present application will be further described in detail below with reference to the accompanying drawings and embodiments.

[0071] The features and exemplary embodiments of various aspects of the present application will be described in detail below. To make the objectives, technical solutions, and advantages of the present application clearer and more understandable, the present application will be further described in detail below in conjunction with the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described herein are only configured to explain the present application and are not configured to limit the present application. For those skilled in the art, the present application can be implemented without some of these specific details. The following description of the embodiments is only to provide a better understanding of the present application by showing examples of the present application.

[0072] It should be noted that, in this document, relational terms such as first and second are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the term "comprising", "including" or any other variant thereof is intended to cover a non-exclusive inclusion, such that a process, method, article or device comprising a series of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article or device. Without further limitation, an element defined by the statement "comprising..." does not exclude the presence of additional identical elements in the process, method, article or device comprising the element.

[0073] It should be understood that the term "and / or" used herein is only a relational term describing the associated objects, indicating that three relationships may exist. For example, A and / or B may represent: A exists alone, A and B exist simultaneously, and B exists alone. In addition, the character " / " in this document generally represents an "or" relationship between the associated objects before and after.

[0074] Embodiment 1

[0075] The method for determining the cavitation margin warning value provided by the embodiment of the present application is applicable to the polysilicon production process. The method for determining the cavitation margin warning value can be applied to the circulation pump of the polysilicon production process and can be executed by a cavitation margin warning value determination device, an electronic device, etc. Hereinafter, an example will be given in which the method for determining the cavitation margin warning value is executed by an electronic device.

[0076] As Figure 1 shown, the method for determining the cavitation margin warning value provided by the embodiment of the present application may include steps S1 to S2.

[0077] S1. Obtain the net positive suction head available (NPSHa) of the circulating pump and the first region information. The NPSHa is determined based on the second region information. The first region information includes the safety margin S and the required net positive suction head (NPSHr). The second region information includes the real-time value of the container discharge temperature, the real-time value of the dichlorosilane component content, the real-time value of the trichlorosilane component content, and the real-time value of the silicon tetrachloride content.

[0078] S2. Determine the cavitation margin warning value NPSH of the circulating pump according to the NPSHa and the first region information.

[0079] According to the cavitation margin warning value determination method provided by the embodiments of the present application, first obtain the NPSHa of the circulating pump and the first region information, and then determine the cavitation margin warning value NPSH of the circulating pump according to the NPSHa and the first region information. Among them, the NPSHa is determined according to the second region information, and the first region information includes the safety margin S and the NPSHr. That is to say, the embodiments of the present application obtain the real-time value of the container discharge temperature, the real-time value of the dichlorosilane component content, the real-time value of the trichlorosilane component content, and the real-time value of the silicon tetrachloride content by detecting the material component content and the container discharge temperature of the circulating pump in real time, that is, by obtaining the parameters related to the cavitation margin of the circulating pump in real time, and then determining the cavitation margin warning value NPSH of the circulating pump accordingly, so as to realize the real-time monitoring of the circulating pump.

[0080] The specific implementation manners of the above steps are introduced below.

[0081] In step S1, the circulating pump can be any circulating pump for which the cavitation margin warning value needs to be determined.

[0082] In some embodiments, obtaining the NPSHa of the circulating pump specifically includes:

[0083] Obtain the target bubble point pressure of the circulating pump at different temperatures. The target bubble point pressure is the bubble point pressure of any two of dichlorosilane (DCS), trichlorosilane (TCS), and silicon tetrachloride (STC);

[0084] Determine the saturated vapor pressure Pv according to the target bubble point pressure;

[0085] Determine the NPSHa of the circulating pump according to the saturated vapor pressure Pv.

[0086] In this embodiment, through the target bubble point pressure, the saturated vapor pressure Pv can be accurately determined. Furthermore, according to the saturated vapor pressure Pv, the NPSHa of the circulating pump can be accurately determined, which provides a basis for subsequently determining the cavitation margin warning value NPSH of the circulating pump according to the NPSHa.

[0087] Exemplarily, the bubble point pressure may be the pressure at which a liquid mixture starts to vaporize (produces the first bubble) at a certain temperature.

[0088] Exemplarily, the saturated vapor pressure Pv may be the vapor-liquid equilibrium pressure of a pure substance at a certain temperature. For a mixture, the sum of the partial pressures of each component is equal to the target bubble point pressure, where the partial pressure is a weighted value of the saturated vapor pressure, and the weight is determined by the liquid phase composition and the activity coefficient.

[0089] In some examples, obtaining the target bubble point pressure of the circulating pump at different temperatures specifically includes:

[0090] Obtaining the target bubble point pressure of the circulating pump at different temperatures through simulation software.

[0091] In this example, obtaining the target bubble point pressure of the circulating pump at different temperatures through simulation software can improve the accuracy of obtaining the target bubble point pressure.

[0092] That is to say, the bubble point pressure (i.e., the target bubble point pressure) of any binary component in different temperatures and in any ternary system of DCS, TCS, and STC can be exported through simulation software.

[0093] In some examples, determining the net positive suction head available (NPSH a) of the circulating pump according to the saturated vapor pressure Pv specifically includes:

[0094] Obtaining the local atmospheric pressure P0, the acceleration due to gravity g, the discharge pressure P of the circulating pump vs , the real-time value of the material density ρ, the inlet line resistance drop H ls , the height H1 from the zero point of the container liquid level to the pump inlet, and the real-time value of the container liquid level H2;

[0095] According to the local atmospheric pressure P0, the acceleration due to gravity g, the discharge pressure P vs , the real-time value of the material density ρ, the inlet line resistance drop H ls , the height H1 from the zero point of the container liquid level to the pump inlet, the real-time value of the container liquid level H2, and the saturated vapor pressure Pv, determine the net positive suction head available (NPSHa) of the circulating pump.

[0096] Exemplarily, both the local atmospheric pressure P0 and the acceleration due to gravity g can be preset in the electronic device for subsequent direct calling; the discharge pressure P of the circulating pump vs can be obtained through real-time measurement.

[0097] In some examples, obtaining the real-time value of the material density ρ of the circulating pump specifically includes:

[0098] Obtaining the real-time value of the container feed temperature of the circulating pump and the second area information;

[0099] Determine the real-time value ρ of the material density of the circulation pump according to the real-time value of the container feed temperature and the second region information.

[0100] In this embodiment, according to the real-time value of the container feed temperature and the second region information, the real-time value ρ of the material density of the circulation pump can be determined quickly and accurately.

[0101] Exemplarily, the real-time value of the container feed temperature of the circulation pump can be obtained by real-time measurement.

[0102] Exemplarily, obtaining the real-time values of the dichlorosilane component content, the trichlorosilane component content, and the silicon tetrachloride content specifically includes:

[0103] S201: Obtain the type of the container in the loop where the circulation pump is located, and this type includes the separation tower type or the tank type.

[0104] S202: For the container of the separation tower type, obtain the bubble point pressure scatter table under different temperatures and TCS components under the DCS-TCS binary interaction, and the bubble point pressure scatter table under different temperatures and TCS components under the TCS-STC binary interaction, and then convert the two tables into the relationship between temperature, pressure, and components. Specifically, the following steps need to be experienced:

[0105] S202-1: Obtain the bubble point pressure scatter table under different temperatures and TCS components under the DCS-TCS binary interaction;

[0106] S202-2: Obtain the bubble point pressure scatter table under different temperatures and TCS components under the TCS-STC binary interaction;

[0107] S202-3: For the scatter table obtained in S202-1, convert it into a binary linear scatter table of DCS and TCS bubble point components under different temperatures and pressures under the DCS-TCS binary interaction. Optionally, this process is converted using the v4 interpolation module of matlab software;

[0108] S202-4: For the scatter table obtained in S202-2, convert it into a binary linear scatter table of TCS and STC bubble point components under different temperatures and pressures under the TCS-STC binary interaction. Optionally, this process is orthogonally converted using the v4 interpolation module of matlab software;

[0109] S202-5: Obtain the real-time values of the temperature and pressure at the part where the tower and the circulation pump participate in the circulation, and through the binary linear scatter table obtained in S202-1, use binary linear interpolation to calculate the DCS and TCS components under the DCS-TCS binary interaction in real time;

[0110] S202-6: Obtain the real-time values of temperature and pressure at the part of the tower where the circulating pump participates in the circulation. Through the binary linear scatter table obtained in S202-2, use binary linear interpolation to calculate the components of TCS and STC under the binary interaction of TCS-STC in real time;

[0111] S202-7: According to the component information obtained in steps S202-5 and S202-6, perform normalization processing to obtain the final components of DCS, TCS, and STC (i.e., the real-time values of the content of dichlorosilane component, trichlorosilane component, and silicon tetrachloride content).

[0112] S203: For container types of tanks, on the basis of calculating the components in the tank by using the method of calculating the components in the tower in step S202, obtain the real-time components of the feed. Equate the components of the withdrawn material to the tank capacity, and use the amounts of the material in the tank, feed, and withdrawn material as weights to calculate the final contents of DCS, TCS, and STC components in the tank (i.e., the real-time values of the content of dichlorosilane component, trichlorosilane component, and silicon tetrachloride content). Optionally, for the determination of the real-time components of the feed, the component contents detected in the LIMS database can be obtained in real time, or it can be calculated by detailed analysis and modeling of the upstream system.

[0113] Exemplarily, according to the real-time value of the feed temperature of the container and the second region information, determine the real-time value ρ of the material density of the circulating pump, specifically including:

[0114] S301: Obtain the real-time value of the material temperature (i.e., the real-time value of the feed temperature of the container of the circulating pump) and the real-time values of the components of DCS, TCS, and STC in the material (i.e., the real-time values of the content of dichlorosilane component, trichlorosilane component, and silicon tetrachloride content in the circulating pump);

[0115] S302: Obtain the density scatter table of DCS at different temperatures, the density scatter table of TCS at different temperatures, and the density scatter table of STC at different temperatures. Optionally, it can be directly exported through the physical property library of the simulation software;

[0116] S303: Through the real-time value of the material temperature obtained in step S301 and the density scatter tables of DCS, TCS, and STC at different temperatures obtained in step S302, calculate the real-time values of the densities of DCS, TCS, and STC at this temperature by means of linear interpolation;

[0117] S304: Use the real-time values of the components of DCS, TCS, and STC in the material obtained in step S301 as weights, and perform weighted summation with the real-time values of the densities of DCS, TCS, and STC at this temperature in S303 respectively to calculate the final real-time value of the density of the material at this temperature (i.e., the real-time value ρ of the material density of the circulating pump).

[0118] In some examples, obtain the resistance drop H of the inlet pipeline of the circulating pump ls , specifically including:

[0119] Obtain the gravitational acceleration g, the real-time value P of the friction pressure drop of the circulating pump mo , the relative density γ of the material, and all other pressure drops; all other pressure drops include all pressure drops except the initial value of the control valve pressure drop, the heat exchanger pressure drop, the reactor pressure drop, the filter pressure drop, the orifice plate pressure drop, other pressure drops, and the variable pressure drop of the pipeline;

[0120] Substitute the gravitational acceleration g, the real-time value P of the friction pressure drop mo , the relative density γ of the material, and all other pressure drops into formula (2) to calculate the resistance drop H of the inlet pipeline ls ;

[0121] Formula (2) includes:

[0122] H ls =(P mo + all other pressure drops) / g / γ (2).

[0123] In this example, through the above formula (2), the resistance drop H of the inlet pipeline can be quickly and accurately determined ls .

[0124] Exemplarily, the relative density γ of the material = the real-time value ρ of the material density / 1000.

[0125] Exemplarily, all other pressure drops can be obtained through real-time measurement.

[0126] In some examples, obtain the real-time value P of the friction pressure drop of the circulating pump mo , specifically including:

[0127] Obtain the equivalent length Le of the circulating pump, the real-time value λ of the friction coefficient, the flow rate Q, the real-time value ρ of the material density, the third region information, and the fluid velocity Vs. The third region information includes the total number of different-diameter pipes and pipe orifices, and the pipeline length L;

[0128] Substitute the equivalent length Le, the real-time value λ of the friction coefficient, the flow rate Q, the real-time value ρ of the material density, the third region information, and the fluid velocity Vs into formula (3) to calculate the real-time value P of the friction pressure drop of the circulating pump mo ;

[0129] Formula (3) includes:

[0130] P mo =(λ(Le + L) / D + the total number of different-diameter pipes and pipe orifices)*Vs 2 *ρ / 2 (3).

[0131] In this example, through the above formula (3), the real-time value P of the frictional pressure drop of the circulating pump can be quickly and accurately determined. mo .

[0132] Exemplarily, the sum of the number of reducing pipes and pipe orifices can be pre-stored in the electronic device and directly called later. The pipeline length L can be obtained through real-time measurement.

[0133] In some examples, obtaining the equivalent length Le of the circulating pump specifically includes:

[0134] Obtaining the pipe diameter D of the circulating pump and the fourth area information, where the fourth area information includes the pipe diameter, the number of 90-degree elbows, the number of 45-degree elbows, the number of straight-through tees, the number of side-out tees, the total number of valves, the number of globe valves, the number of check valves, the number of butterfly valves, the number of angle valves, and the number of reducing pipes; the total number of valves is the sum of the number of gate valves, the number of ball valves, and the number of plug valves;

[0135] Substitute the fourth area information into formula (4) to calculate the equivalent length Le of the circulating pump;

[0136] Formula (4) includes:

[0137] Le = D / 1000 × (35 × number of 90-degree elbows + 16 × number of 45-degree elbows + 20 × number of straight-through tees + 60 × number of side-out tees + 40 × total number of valves + 300 × number of globe valves + 200 × number of check valves + 40 × number of butterfly valves + 145 × number of angle valves + 10 × number of reducing pipes) (4).

[0138] In this example, through the above formula (4), the equivalent length Le of the circulating pump can be quickly and accurately determined.

[0139] Exemplarily, the number of check valves can be the number of swing check valves.

[0140] Exemplarily, both the pipe diameter D of the circulating pump and the fourth area information can be obtained through real-time measurement.

[0141] Exemplarily, obtaining the real-time value λ of the friction coefficient of the circulating pump specifically includes:

[0142] Obtaining the real-time value ρ of the material density and the real-time value μ of the material viscosity of the container in the loop where the circulating pump is located, the flow rate Q of the circulating pump, and the pipe diameter D;

[0143] Substitute the real-time value ρ of the material density, the real-time value μ of the material viscosity, the flow rate Q, and the pipe diameter D into formula (6) to calculate the real-time value Re of the Reynolds number;

[0144] Convert the real-time value Re of the Reynolds number to the real-time value λ of the friction coefficient of the circulating pump;

[0145] Formula (6) includes:

[0146] Re = D * Vs * ρ / μ (4).

[0147] Exemplarily, obtaining the real-time value μ of the material viscosity of the container includes:

[0148] Obtaining the real-time value of the container feed temperature and the second region information of the circulation pump;

[0149] Determining the real-time value μ of the material viscosity of the container according to the real-time value of the container feed temperature and the second region information of the circulation pump.

[0150] Specifically, determining the real-time value μ of the material viscosity of the container according to the real-time value of the container feed temperature and the second region information of the circulation pump includes:

[0151] S401: Obtaining the real-time value of the material temperature (i.e., the real-time value of the container feed temperature)) and the real-time values of the DCS, TCS, and STC components of the material (i.e., the real-time values of the dichlorosilane component content, the trichlorosilane component content, and the silicon tetrachloride content);

[0152] S402: Obtaining the viscosity scatter table of DCS at different temperatures, the viscosity scatter table of TCS at different temperatures, and the viscosity scatter table of STC at different temperatures. Optionally, it can be directly exported through the physical property library of the simulation software;

[0153] S403: Through the real-time value of the material temperature obtained in step S401 and the viscosity scatter tables of DCS, TCS, and STC at different temperatures obtained in step S402, calculate the real-time values of the viscosities of DCS, TCS, and STC at this temperature by means of linear interpolation;

[0154] S404: Calculate the final real-time value of the material viscosity (i.e., the real-time value μ of the material viscosity of the container) through the real-time values of the viscosities of DCS, TCS, and STC obtained in S403, the real-time values of the DCS, TCS, and STC components of the material obtained in step S401, and formula (7).

[0155] Formula (7) includes:

[0156] μ = e DCS粘度×ln(DCS含量)+TCS粘度×ln(TCS含量)+STC粘度×ln(STC含量) (7).

[0157] Wherein, DCS 粘度 represents the real-time value of the DCS viscosity; DCS 含量 represents the real-time value of the DCS component; TCS 粘度 represents the real-time value of the TCS viscosity; TCS 含量 represents the real-time value of the TCS component; STC 粘度 represents the real-time value of the STC viscosity; STC 含量 represents the real-time value of the STC component.

[0158] Exemplarily, the flow rate Q of the circulation pump can be obtained through real-time measurement.

[0159] Exemplarily, the fluid velocity Vs can be calculated by formula (8). Formula (8) includes:

[0160] Vs = (Q / 3600) / [0.785 × (D / 1000) 2 (8).

[0161] Exemplarily, converting the real-time value Re of the Reynolds number into the real-time value λ of the friction coefficient of the circulation pump specifically includes:

[0162] S106-1: Obtain the relative roughness ε / D of the pipeline. Among them, ε is the absolute roughness of the pipeline, and the specific values are as follows:

[0163] General stainless steel: 0.0015 mm;

[0164] Carbon steel: 0.0500 mm;

[0165] Seamless steel pipe: 0.2 mm;

[0166] Welded steel pipe: 0.2 - 0.3 mm;

[0167] Foreign carbon steel: 0.0457 mm;

[0168] S106-2: Through simulation software, obtain the scatter plots of the relationship between Re and λ in the smooth zone and transition zone of the hydraulic pipeline respectively. Among them, the equation of the smooth zone of the hydraulic pipeline is The equation of the transition zone is

[0169] S106-3: According to the condition judgment, calculate the real-time value λ of the friction coefficient in real time:

[0170] When Re ≤ 2000,

[0171] When Re > 2000 and ε / D < 15 / Re, use the scatter plot of the relationship between Re and λ in the smooth zone of the hydraulic pipeline for one-dimensional linear interpolation to obtain λ;

[0172] When Re > 2000 and 15 / Re ≤ ε / D ≤ 560 / Re, use the scatter plot of the relationship between Re and λ in the transition zone for one-dimensional linear interpolation to obtain λ;

[0173] When Re > 2000 and ε / D > 560,

[0174] In some examples, the net positive suction head NPSHa satisfies formula (1);

[0175] Formula (1) includes:

[0176] NPSHa = (P vs + P0 / 1000 - Pv) × 100000 / ρg + H1 + H2 - H ls (1).

[0177] In this example, through the above formula, the net positive suction head available NPSHa can be determined quickly and accurately.

[0178] In step S2, after the electronic device obtains the net positive suction head available NPSHa of the circulating pump and the first area information, it can also determine the cavitation margin warning value NPSH of the circulating pump according to the net positive suction head available NPSHa and the first area information.

[0179] In addition, in the embodiments of the present application, by considering the safety margin S to determine the cavitation margin warning value NPSH of the circulating pump, the rationality of determining the cavitation margin warning value NPSH of the circulating pump can be improved.

[0180] Exemplarily, the cavitation margin warning value NPSH of the circulating pump can be used to characterize the degree of warning required for the cavitation margin.

[0181] In some embodiments, the cavitation margin warning value NPSH satisfies formula (5), and formula (5) includes:

[0182] NPSH = NPSHa - NPSHr - S (5).

[0183] In this embodiment, through the above formula (5), the cavitation margin warning value NPSH can be determined quickly and accurately.

[0184] To better understand the cavitation margin warning value determination method provided by the embodiments of the present application, the following will be described in conjunction with a specific embodiment.

[0185] A real-time calculation method for the cavitation state of a circulating pump based on the polysilicon production process (i.e., the cavitation margin warning value determination method) includes the following steps:

[0186] S101: Real-time obtain or calculate the container area information in the loop where the circulating pump is located, including container feed (i.e., the real-time value of the container feed temperature), the temperature of the discharge (to the circulating pump) (i.e., the real-time value of the container discharge temperature), the pressure (i.e., the discharge pressure P vs ), the DCS component content (i.e., the real-time value of the dichlorosilane component content), the TCS component content (i.e., the real-time value of the trichlorosilane component content), and the STC component content (i.e., the real-time value of the silicon tetrachloride content).

[0187] S102: Obtain the information of the container, circulation pump and the pipeline area therebetween in real time, including the height from the zero point of the container liquid level to the pump inlet, the real-time value of the container liquid level, the pipeline diameter D, the safety margin, the pipeline length, the required net positive suction head of the pump, the flow rate Q of the pump, the number of 90-degree elbows, the number of 45-degree elbows, the number of straight-through tees, the number of side-out tees, the number of gate valves, the number of ball valves, the number of plug valves, the number of globe valves, the number of swing check valves, the number of butterfly valves, the number of angle valves, the number of reducers, the number of pipe orifices, the elevation difference between the pump inlet and the base liquid level, the initial value of the pressure drop of the regulating valve, the pressure drop of the heat exchanger, the pressure drop of the reactor, the pressure drop of the filter, the pressure drop of the orifice plate, other pressure drops, and the variable pressure drop of the pipeline.

[0188] S103: According to the temperature of the container feed and discharge, the DCS component content, the TCS component content, and the STC component content obtained in step S101, calculate the material density ρ (i.e., the real-time value of the material density ρ) in the container in real time, and calculate the relative density γ of the material in the container accordingly.

[0189] S104: According to the temperature of the container feed and discharge, the DCS component content, the TCS component content, and the STC component content obtained in step S101, calculate the material viscosity μ in the container in real time.

[0190] S105: According to the pipeline diameter D obtained in step S102, the flow rate Q of the pump, and the material density ρ and material viscosity μ (i.e., the real-time value of the material viscosity μ) obtained in steps S103 and S104 respectively, calculate the real-time value of the Reynolds number Re of the fluid in the pump in real time.

[0191] The specific calculation formula is Re = D * Vs * ρ / μ;

[0192] where Vs = (Q / 3600) / [0.785 × (D / 1000) 2 .

[0193] S106: According to the real-time value of the Reynolds number Re obtained in step S105, complete the real-time conversion between Re and the friction coefficient λ value.

[0194] S107: According to the pipeline diameter, the number of 90-degree elbows, the number of 45-degree elbows, the number of straight-through tees, the number of side-out tees, the number of gate valves, ball valves, plug valves (i.e., the total number of valves), the number of globe valves, the number of swing check valves, the number of butterfly valves, the number of angle valves, and the number of reducers obtained in step S102, calculate the equivalent length Le in real time.

[0195] Le = D / 1000 × (35 × number of 90-degree elbows + 16 × number of 45-degree elbows + 20 × number of straight-through tees + 60 × number of side-out tees + 40 × number of gate valves, ball valves, plug valves + 300 × number of globe valves + 200 × number of swing check valves + 40 × number of butterfly valves + 145 × number of angle valves + 10 × number of reducers).

[0196] S108: Based on the equivalent length Le obtained in step S107, the real-time value of the friction coefficient λ obtained in step S106, the flow rate Q of the pump in step S102, the number of reducers and pipe orifices and the pipeline length L, and the material density ρ obtained in step S103, calculate the friction pressure drop P in real time mo real-time value (i.e., the real-time value of the friction pressure drop P mo ).

[0197] P mo = (λ(Le + L) / D + number of reducers and pipe orifices) * Vs2 * ρ / 2.

[0198] S109: Based on the friction pressure drop P obtained in step S108 mo , combined with all other pressure drops obtained in step S102, the gravitational acceleration g, and the relative density γ of the material obtained in step S103, calculate the inlet pipeline resistance drop H in real time ls (inlet pipeline resistance drop H ls ).

[0199] H ls = (P mo + all other pressure drops) / g / γ.

[0200] S110: Calculate the material outlet temperature and composition in step S101 in real time, calculate the corresponding saturated vapor pressure Pv. Optionally, this process can export the bubble point pressures of different temperatures and any binary components in the DCS, TCS, STC ternary system through simulation software;

[0201] S111: Based on the local atmospheric pressure P0, the saturated vapor pressure obtained in step S110, the real-time value H2 of the container liquid level obtained in step S102, the height H1 from the zero point of the container liquid level to the pump inlet, the discharge pressure P obtained in step S101 vs , the inlet pipeline resistance drop H obtained in real time in step S109 ls , calculate the net positive suction head available NPSHa of the pump.

[0202] NPSHa = (P vs + P0 / 1000 - Pv) × 100000 / ρg + H1 + H2 - H ls ;

[0203] S112: Based on the net positive suction head available (NPSHa) of the pump obtained from the implementation of S111, combined with the safety margin S and the required net positive suction head (NPSHr) obtained in step S102, obtain the real-time cavitation margin warning value NPSH, and use this warning value as a parameter for real-time monitoring of the pump cavitation state.

[0204] NPSH = NPSHa - NPSHr - S.

[0205] Based on a real-time monitoring method for the cavitation state of a circulating pump in a polysilicon production process, a real-time calculation method for the components in a container with chlorosilane as the medium in a polysilicon production process is given for steps S103 and S104, including the following steps:

[0206] S201: Obtain the type of the container and determine whether its type is a separation tower type or a tank type.

[0207] S202: For a container of the tower type (i.e., the separation tower type), obtain the bubble point pressure scatter table under different temperatures and TCS components under the DCS-TCS binary interaction, and the bubble point pressure scatter table under different temperatures and TCS components under the TCS-STC binary interaction, and then convert the two tables into the relationship between temperature, pressure, and components. Specifically, the following steps need to be experienced:

[0208] S202-1: Obtain the bubble point pressure scatter table under different temperatures and TCS components under the DCS-TCS binary interaction;

[0209] S202-2: Obtain the bubble point pressure scatter table under different temperatures and TCS components under the TCS-STC binary interaction;

[0210] S202-3: For the scatter table obtained in S202-1, convert it into a DCS-TCS binary interaction, DCS and TCS bubble point component binary linear scatter table under different temperatures and pressures. Preferably, this process is converted using the v4 interpolation module of matlab software;

[0211] S202-4: For the scatter table obtained in S202-2, convert it into a TCS-STC binary interaction, TCS and STC bubble point component binary linear scatter table under different temperatures and pressures. Preferably, this process is orthogonally converted using the v4 interpolation module of matlab software;

[0212] S202-5: Obtain the real-time values of temperature and pressure at the part of the tower where the pump participates in the cycle, and through the binary linear scatter table obtained in S202-1, use binary linear interpolation to calculate the DCS and TCS components under the DCS-TCS binary interaction in real time;

[0213] S202-6: Obtain the real-time values of temperature and pressure at the part where the pump participates in the circulation inside the tower. Using the binary linear scatter table obtained through S202-2, and by means of binary linear interpolation, calculate the TCS and STC components under the binary interaction of TCS-STC in real time;

[0214] S202-7: According to the component information obtained in steps S202-5 and S202-6, perform normalization processing to obtain the final DCS, TCS, and STC components.

[0215] S203: For container of tank type, on the basis of calculating the components inside the tank in the same way as calculating the components inside the tower using step S202, obtain the real-time feed components, equate the components of the withdrawn material to the content of the tank, and calculate the final content of DCS, TCS, and STC components inside the tank with the amounts of the material inside the tank, feed, and withdrawn material as weights. Optionally, for the determination of the real-time feed components, the component content detected in the LIMS database can be obtained in real time, or it can be calculated through detailed analysis and modeling of the upstream system.

[0216] Based on step S103, a method for real-time monitoring of the density of chlorosilane based on the polysilicon production process is provided, including the following steps:

[0217] S301: Obtain the real-time value of the material temperature and the real-time values of the DCS, TCS, and STC components of the material;

[0218] S302: Obtain the density scatter table of DCS at different temperatures, the density scatter table of TCS at different temperatures, and the density scatter table of STC at different temperatures. Preferably, it can be directly exported through the physical property library of the simulation software;

[0219] S303: Through the real-time value of the material temperature obtained in step S301 and the density scatter tables of DCS, TCS, and STC at different temperatures obtained in step S302, calculate the real-time density values of DCS, TCS, and STC at this temperature by means of unary linear interpolation;

[0220] S304: Using the real-time values of the DCS, TCS, and STC components of the material obtained in step S301 as weights, calculate the real-time value of the final density of the material at this temperature;

[0221] S305: Calculate the relative density value = the real-time density value obtained in S304 / 1000.

[0222] Based on step S104, a method for real-time monitoring of the viscosity of chlorosilane based on the polysilicon production process is provided, including the following steps:

[0223] S401: Obtain the real-time value of the material temperature and the real-time values of the DCS, TCS, and STC components of the material;

[0224] S402: Obtain the viscosity scatter tables of DCS at different temperatures, the viscosity scatter tables of TCS at different temperatures, and the viscosity scatter tables of STC at different temperatures. Preferably, they can be directly exported through the physical property library of the simulation software;

[0225] S403: Based on the real-time value of the material temperature obtained in step S401 and the viscosity scatter tables of DCS, TCS, and STC at different temperatures obtained in step S402, calculate the real-time viscosity values of DCS, TCS, and STC at this temperature by means of linear interpolation;

[0226] S404: Calculate the real-time viscosity value of the final material based on the real-time viscosity values of DCS, TCS, and STC obtained in S403 and the real-time component values of DCS, TCS, and STC in the material obtained in step S401:

[0227] Real-time material viscosity value = viscosity of eDCS × ln(DCS content) + viscosity of TCS × ln(TCS content) + viscosity of STC × ln(STC content).

[0228] The specific steps of step S106 are as follows:

[0229] S106-1: Obtain the relative roughness ε / D of the pipeline. Among them, ε is the absolute roughness of the pipeline, and the specific values are as follows:

[0230] General stainless steel: 0.0015 mm;

[0231] Carbon steel: 0.0500 mm;

[0232] Seamless steel pipe: 0.2 mm;

[0233] Welded steel pipe: 0.2 - 0.3 mm;

[0234] Foreign carbon steel: 0.0457 mm;

[0235] S106-2: Through the simulation software, obtain the scatter diagrams of the relationship between Re and λ in the smooth zone and transition zone of the hydraulic pipeline respectively. Among them, the equation for the smooth zone of the hydraulic pipeline is The equation for the transition zone is

[0236] S106-3: According to the condition judgment, calculate the real-time value of the friction coefficient λ in real time:

[0237] When Re ≤ 2000,

[0238] When Re > 2000 and ε / D < 15 / Re, use the scatter diagram of the relationship between Re and λ in the smooth zone of the hydraulic pipeline for linear interpolation to obtain λ;

[0239] When Re > 2000 and 15 / Re ≤ ε / D ≤ 560 / Re, λ is obtained by performing linear interpolation on the scatter plot of the relationship between Re and λ in the transition region.

[0240] When Re > 2000 and ε / D > 560,

[0241] Exemplarily, to better understand the method for determining the cavitation margin warning value provided in the embodiments of the present application, the following will be described in conjunction with a more specific calculation implementation.

[0242] A buffer tank with the tag number 0501-V0315 is known, and the stored medium is mainly TCS and STC. There are two inlet streams to the buffer tank, and the corresponding flow measurement point tags are 0501_803_03_FIC_1501.PV and 0501_803_03_FIC_1502.PV respectively, and the corresponding cumulative flow measurement points are 0501_803_03_FIQ_1501.AV and 0501_803_03_FIQ_1502.AV respectively. Upstream of them are both tower systems, namely Tower 8A and Tower 8B (the materials in the towers are TCS and STC), and both towers are in the bubble-point feed state. There is also a material reflux in the buffer tank, and there is a circulation pump (tag number 0501-P0330) to maintain the circulation operation. There are also two outlet streams from the buffer tank, and the corresponding cumulative flow measurement points are 0501_803_03_FIQ_1503.AV and 0501_803_03_FIQ_2201.AV respectively. It is necessary to realize the real-time monitoring of the cavitation state of the circulation pump 0501-P0330 under this buffer tank system.

[0243] Collect the required on-site instrument measurement points through the DCS system, and after OPC DA conversion, transfer them into the core database through the data interface in json format. The detailed information of the required points is shown in Table 1, and the information required to be obtained from the database of the equipment master data is shown in Table 2.

[0244] Table 1

[0245]

[0246]

[0247] Table 2

[0248]

[0249]

[0250] First, determine the current component content of the materials in the buffer tank system. Set the time difference between material feeding and discharging to 5 minutes. At the same time, determine the lengths of the two pipelines corresponding to the cumulative flow measurement points 0501_803_03_FI Q_1501.AV and 0501_803_03_FIQ_1502.AV from the tower to the buffer tank for calculating the flow delay:

[0251] Delay1501 = 50.77 / ('0501_803_03_FIC_1501.PV' / (Pi() * 0.125 * 0.125) / 3600);

[0252] Delay1502 = 39.20 / ('0501_803_03_FIC_1502.PV' / (Pi() * 0.125 * 0.125) / 3600);

[0253] Among them, 50.77 and 39.20 are the pipeline lengths of the corresponding pipelines from the tower to the buffer tank; Pi() is the constant of pi.

[0254] On this basis, obtain the time stamp of the delay at the current time:

[0255] DelayTS1501 = TimeStamp('0501_803_03_FIC_1501.PV') - 'Delay1501';

[0256] DelayTS1502 = TimeStamp('0501_803_03_FIC_1502.PV') - 'Delay1502';

[0257] Among them, the TimeStamp() function is a function provided by the modeling backend attached to the core database in this embodiment to obtain the time stamp of the nearest time series sample at a certain point, which can generally be regarded as the time stamp of the current time.

[0258] When the preset calculation time difference between the material inlet and outlet is 5 minutes, calculate the feed rate:

[0259] FIQ1501IN = 'FIQ1501REAL' - 'FIQ1501DELTA';

[0260] FIQ1502IN = 'FIQ1502REAL' - 'FIQ1502DELTA';

[0261] Among them, FIQ1501DELTA and FIQ1502DELTA are as follows respectively:

[0262] FIQ1501DELTA = TagVal('FIQ1501REAL', '* - 5m');

[0263] FIQ1502DELTA = TagVal('FIQ1502REAL', '* - 5m');

[0264] Among them, the TagVal(a, b) function is to calculate the value of point a at time b, and '* - 5m' represents the time stamp 5 minutes before the current time. FIQ1501REAL and FIQ1502REAL are as follows:

[0265] FIQ1501REAL = TagVal('0501_803_03_FIQ_1501.AV', 'DelayTS1501');

[0266] FIQ1502REAL = TagVal('0501_803_03_FIQ_1501.AV', 'DelayTS1501');

[0267] When the preset time difference for calculating the material inlet and outlet is 5 minutes, calculate the discharge rate:

[0268] FIQ1503OUT = '0501_803_03_FIQ_1503.AV' - TagVal('0501_803_03_FIQ_1503.AV', '* - 5m');

[0269] FIQ2201OUT = '0501_803_03_FIQ_2201.AV' - TagVal('0501_803_03_FIQ_2201.AV', '* - 5m');

[0270] Since this buffer tank is a horizontal storage tank with an oval head, calculate the volume of the material in the tank according to the real-time value of the liquid level of the tank:

[0271] VI_V_0315 = Pi() / 2 * (Pow(1.3, 3) * ('0501_803_03_LICA_1501.AV' / 1000 - 1.3) - Pow(('0501_803_03_LICA_1501.AV' / 1000 - 1.3), 3) * 3 + 2 / 3 * Pow(1.3, 3)) + (9.8 - 1.3 / 2) * Pow(1.3, 3) * (('0501_803_03_LICA_1501.AV' / 1000 - 1.3) / 1.3 * Sqr(1 - Pow(('0501_803_03_LICA_1501.AV' / 1000 - 1.3) / 1.3, 2)) - Acos(('0501_803_03_LICA_1501.AV' / 1000 - 1.3) / 1.3) + Pi());

[0272] where Pow(a, b) means a b , Sqr(x) means the value of the square root of x, and Acos(x) means cos(x).

[0273] Next, it is necessary to determine the components in the tank, the feed, and the discharge. Since the discharge comes from the tank, the components in the tank and the discharge are regarded as equivalent.

[0274] Since only STC and TCS are involved, when determining the material quantity in the tank and the feed and discharge quantities, the final STC component of the material received by the pump can be calculated in a weighted form as follows:

[0275] The STC content in the V0315 tank = ('STC content in the gas phase at input end A - binary' * 'FIQ1501IN' + 'STC content in the gas phase at input end B - binary' * 'FIQ1502IN' + 'STC content in the liquid phase at the output end' * 'VI_V_0315' - 'STC content in the liquid phase at the output end' * ('FIQ1503OUT' + 'FIQ2201OUT')) / ('FIQ1501IN' + 'FIQ1502IN' + 'VI_V_0315' - 'FIQ1503OUT' - 'FIQ2201OUT');

[0276] The TCS content in the V0315 tank = 1 - the STC content in the V0315 tank;

[0277] Among them, the STC content in the gas phase at input end A - binary, the STC content in the gas phase at input end B - binary, and the STC content in the liquid phase at the output end are all calculated by the physical property library interpolation method provided by the modeling backend attached to the core database in this embodiment. Taking the STC content in the gas phase at input end A - binary as an example, the specific SQL statement is as follows:

[0278] SELECT STC content FROM "Gas-phase STC" WHERE INTERPOLATE(temperature, @[0501_803_03_TI_13A04.AV]) AND INTERPOLATE(pressure, @[0501_803_03_PI_13A04.AV]);

[0279] This is a form of bilinear interpolation. Specifically, "Gas-phase STC" is as Figure 2 shown. @[0501_803_03_TI_13A04.AV] represents introducing the real-time value of the 0501_803_03_TI_13A04.AV point into it for INTERPOLATE() interpolation calculation.

[0280] Due to the re-integration inside the tank, the liquid saturated vapor pressure Pv_P0330 at the conveying temperature cannot be obtained based on the original tank pressure plus the local atmospheric pressure, but through the following method:

[0281] SELECT pressure FROM "Liquid-phase STC target pressure" WHERE INTERPOLATE(STC component, @V0315 STC content inside the tank) AND INTERPOLATE(temperature, @[0501_803_03_TI_1501.AV])

[0282] "Liquid-phase STC target pressure" is a saturated vapor pressure scatter plot based on the TCS-STC binary interaction, under different STC component contents and temperatures.

[0283] Specifically, for the verification of obtaining components in this way, that is, comparing the DCS content calculated by the bilinear interpolation function with the actual value, as shown in Table 3.

[0284] Table 3

[0285]

[0286] For the calculation of material density ρ, relative density γ, and material viscosity are as follows:

[0287] Liquid density inside V0315 tank = 'STC content inside V0315 tank' * 'STC density inside V0315 tank' + 'TCS density inside V0315 tank' * 'TCS content inside V0315 tank';

[0288] Liquid viscosity inside V0315 tank = Exp('STC content inside V0315 tank' * Log('STC viscosity inside V0315 tank') + 'TCS content inside V0315 tank' * Log('TCS viscosity inside V0315 tank'));

[0289] Among them, Log(x) is ln(x).

[0290] When the density and viscosity of the material are known, the fluid velocity Vs is calculated as follows:

[0291] The fluid velocity Vs_P0330 inside the pipe on the inlet side = ('P0330 pump flow rate' / 3600) / (0.785 * Pow('inlet pipe diameter D' / 1000, 2));

[0292] Subsequently, Re can be calculated as follows:

[0293] Re_P0330 = 'inlet pipe diameter D' * 'fluid velocity Vs_P0330 inside the pipe on the inlet side' * 'liquid density in tank V0315' / 'liquid viscosity in tank V0315';

[0294] For the calculation of the friction coefficient, the built-in IF..ELSE.. conditional judgment is used, as follows:

[0295] Lambda_P0330 = if 'Re_P0330' <= 2000 THEN 64 / 'Re_P0330' else (if 'Re_P0330' > 2000 and 'wall relative roughness ε / D' < 15 / 'Re_P0330' then 'lambda in the smooth zone of the hydraulic pipe' else if 'Re_P0330' > 2000 and 'wall relative roughness ε / D' >= 15 / 'Re_P0330' and 'wall relative roughness ε / D' <= 650 / 'Re_P0330' then 'lambda in the transition zone' else Pow(1 / (1.74 - 2 * Log10(2 * 'wall relative roughness ε / D')), 2));

[0296] Among them, the lambda in the smooth zone of the hydraulic pipe and the lambda in the transition zone are carried out by the method of one-dimensional linear interpolation. Taking the transition zone as an example:

[0297] SELECT Lambda FROM [Re-Lambda0.00029 in the transition zone] WHERE INTERPOLATE(Re, @[Re_P0330])

[0298] Among them, the table of Re-Lambda0.00029 in the transition zone is as Figures 3 to 3b shown.

[0299] The calculation of the remaining parameters is as follows:

[0300] Equivalent length_P0330 = 'Inlet pipe diameter D' / 1000 * (35 * '90-degree elbow' + 60 * 'Side outlet tee' + 40 * 'Gate valve. Ball valve. Plug valve' + 10 * 'Reducer');

[0301] Height from the inlet side liquid level to the pump center Hgs_P0330 = - 'Height from the liquid level zero point to the pump inlet H1' - '0501_803_03_LICA_1501.AV' / 1000;

[0302] Pipeline pressure drop_P0330 = ('lambda_P0330' * ('Pipeline length' + 'Equivalent length Le_P0330') / 'Inlet pipe diameter D' + (0.36 * 'Reducer' + 'Pipe orifice') / 1000) * 'Liquid density in V0315 tank' * 'Fluid velocity Vs_P0330 in the inlet side pipe' * 'Fluid velocity Vs_P0330 in the inlet side pipe' / 2;

[0303] Total pipeline pressure drop_P0330 = 'Pipeline pressure drop_P0330' + 'Filter pressure drop';

[0304] Inlet pipeline resistance drop HLs_P0330 = 'Total pipeline pressure drop_P0330' / ('Liquid density in V0315 tank' / 1000) / 'Acceleration due to gravity g';

[0305] Net positive suction head available NPSHa_P0330 = ('Local atmospheric pressure P0' / 1000 + '0501_803_03_PI_1501.AV' - 'Vapor pressure of liquid at the delivery temperature Pv_P0330') * 1000000 / 'Liquid density in V0315 tank' / 'Acceleration due to gravity g' - 'Height from the inlet side liquid level to the pump center Hgs_P0330' - 'Inlet pipeline resistance drop HLs_P0330'

[0306] Net positive suction head warning value_P0330 = 'Net positive suction head available NPSHa_P0330' - 'Safety margin S' - 'Required net positive suction head NPSHr';

[0307] In this way, the real-time value of the net positive suction head of pump 0501 - P0330 (net positive suction head warning value_P0330) is obtained.

[0308] All the above formulas and interpolations are integrated in the modeling backend attached to the core database described in S606, and each formula and interpolation strategy generates a new core database point.

[0309] In this embodiment, the formula function of the modeling backend attached to the core database is as Figures 3 to 3b shown, and for the specific content, please refer to Figures 3 to 3b , which will not be elaborated here.

[0310] In this embodiment, all the new points generated by the modeling backend are transmitted back to the core database in S605, and the core database in S607 retrieves data in real time through the core database and uses various UIs to create a real-time monitoring terminal interface for the cavitation state of pump 0501_P0330, specifically as Figures 4 to 4c shown. For specific content, please refer to Figures 4 to 4c , which will not be elaborated here.

[0311] In this embodiment, the set upper limit threshold for cavitation state alarm is 2m. For alarms exceeding this limit, the alarm information is integrated into the json format and transmitted into the cavitation alarm data interface in S608. Preferably, the development of the cavitation alarm data interface in S608 and the data retrieval strategy through the core database in S607 can be completed by setting the Controller layer through the Springboot framework.

[0312] It should be noted that the method for determining the cavitation margin warning value provided in the embodiment of this application has at least the following beneficial effects:

[0313] 1. The chlorosilane component model mainly composed of dichlorosilane DCS, trichlorosilane TCS, and silicon tetrachloride STC is used for the real-time calculation of the process variable - chlorosilane components in the cavitation judgment of the circulating pump, enabling the real-time monitoring of chlorosilane components;

[0314] 2. The density and viscosity of chlorosilane are calculated in real time, and based on this, real-time conversion can be carried out in the case of mixed use of on-site volumetric flow meters and mass flow meters;

[0315] 3. This process monitors the cavitation state of the circulating pump in the polysilicon production process in real time, avoiding the cumbersome process of manual calculation in the past;

[0316] It should be added that the embodiment of this application provides a method (i.e., a method for determining the cavitation margin warning value) and a device for real-time monitoring of the cavitation state of a circulating pump based on the polysilicon production process, which are used for visualizing the monitoring of the pump cavitation state, and at the same time, also real-time monitoring information such as the component content, material density, material dynamic viscosity, temperature, and pressure of the upstream and downstream materials of the pump, realizing the real-time monitoring of the pump cavitation state.

[0317] Embodiment 2

[0318] The cavitation state monitoring method provided in the embodiment of this application is applicable to the polysilicon production process. This cavitation state monitoring method can be applied to the circulating pump in the polysilicon production process and can be executed by a cavitation state monitoring device, an electronic device, etc. Hereinafter, an example will be given where this cavitation state monitoring method is executed by an electronic device.

[0319] The cavitation state monitoring method provided by the embodiment of the present application includes steps S210 to S220.

[0320] S210. Determine the cavitation margin warning value NPSH of the circulating pump according to the cavitation margin warning value determination method of Embodiment 1.

[0321] S220. Visually display the cavitation margin warning value NPSH to achieve the monitoring of the cavitation state.

[0322] In the embodiment of the present application, by visually displaying the cavitation margin warning value NPSH, the staff can know the cavitation margin warning value NPSH in time, that is, can monitor the cavitation margin in the circulating pump in real time, and then can process the cavitation state of the circulating pump in time.

[0323] Exemplarily, different colors can be displayed according to different cavitation margin warning values NPSH.

[0324] It should be noted that, compared with a series of pipeline improvements in the related art to achieve cavitation state monitoring, the embodiment of the present application does not need to improve the pipeline, which can reduce costs.

[0325] The cavitation state monitoring method provided by the embodiment of the present application includes the cavitation margin warning value determination method in Embodiment 1, that is, has the beneficial effects and implementation manners of the cavitation margin warning value determination method provided by Embodiment 1 of the present application. Specifically, reference can be made to the specific description of the cavitation margin warning value determination method in the above Embodiment 1, and this embodiment will not be elaborated here.

[0326] Embodiment 3

[0327] As Figure 5 shown, the cavitation margin warning value determination device provided by the embodiment of the present application includes a first acquisition module 310 and a first determination module 320.

[0328] Among them, the first acquisition module 310 is used to acquire the cavitation margin NPSHa of the circulating pump and the first area information, and the cavitation margin NPSHa is determined according to the second area information; the first area information includes the safety margin S and the required cavitation margin NPSHr; the second area information includes the real-time value of the container discharge temperature, the real-time value of the dichlorosilane component content, the real-time value of the trichlorosilane component content, and the real-time value of the silicon tetrachloride content.

[0329] The first determination module 320 is connected to the first acquisition module 310 and is used to determine the cavitation margin warning value NPSH of the circulating pump according to the cavitation margin NPSHa and the first area information.

[0330] In some implementation manners, the first acquisition module 310 is specifically used for:

[0331] Obtain the target bubble point pressure of the circulating pump at different temperatures; the target bubble point pressure is the bubble point pressure of any two of dichlorosilane, trichlorosilane, and silicon tetrachloride;

[0332] Determine the saturated vapor pressure Pv according to the target bubble point pressure;

[0333] Determine the net positive suction head available (NPSHa) of the circulating pump according to the saturated vapor pressure Pv.

[0334] In some embodiments, the first acquisition module 310 is specifically configured to:

[0335] Obtain the target bubble point pressure of the circulating pump at different temperatures through simulation software.

[0336] In some embodiments, the first acquisition module 310 is specifically configured to:

[0337] Obtain the local atmospheric pressure P0, gravitational acceleration g, discharge pressure P of the circulating pump vs , real-time value of material density ρ, inlet pipeline resistance drop H ls , height H1 from the zero point of the container liquid level to the pump inlet, and real-time value of the container liquid level H2;

[0338] According to the local atmospheric pressure P0, gravitational acceleration g, discharge pressure P vs , real-time value of material density ρ, inlet pipeline resistance drop H ls , height H1 from the zero point of the container liquid level to the pump inlet, real-time value of the container liquid level H2, and saturated vapor pressure Pv, determine the net positive suction head available (NPSHa) of the circulating pump.

[0339] In some embodiments, the net positive suction head available (NPSHa) satisfies formula (1); formula (1) includes:

[0340] NPSHa = (P vs + P0 / 1000 - Pv) × 100000 / ρg + H1 + H2 - H ls (1).

[0341] In some embodiments, the first acquisition module 310 is specifically configured to:

[0342] Obtain the gravitational acceleration g, real-time value of the friction pressure drop P of the circulating pump mo , relative density γ of the material, and all other pressure drops; all other pressure drops include all pressure drops except the initial value of the control valve pressure drop, heat exchanger pressure drop, reactor pressure drop, filter pressure drop, orifice plate pressure drop, other pressure drops, and pipeline variable pressure drops;

[0343] Substitute the gravitational acceleration g, real-time value of the friction pressure drop P mo , relative density γ of the material, and all other pressure drops into formula (2) to calculate the inlet pipeline resistance drop Hls ;

[0344] Equation (2) includes:

[0345] H ls = (P mo + all other pressure drops) / g / γ (2).

[0346] In some embodiments, the first acquisition module 310 is specifically configured to:

[0347] Acquire the equivalent length Le of the circulation pump, the real-time value λ of the friction coefficient, the flow rate Q, the real-time value ρ of the material density, the third region information, and the fluid flow velocity Vs. The third region information includes the sum of the number of different-diameter pipes and pipe orifices, and the pipeline length L;

[0348] Substitute the equivalent length Le, the real-time value λ of the friction coefficient, the flow rate Q, the real-time value ρ of the material density, the third region information, and the fluid flow velocity Vs into Equation (3) to calculate the real-time value P of the friction pressure drop of the circulation pump mo ;

[0349] Equation (3) includes:

[0350] P mo = (λ(Le + L) / D + the sum of the number of different-diameter pipes and pipe orifices) * Vs 2 * ρ / 2 (3).

[0351] In some embodiments, the first acquisition module 310 is specifically configured to:

[0352] Acquire the pipe diameter D of the circulation pump and the fourth region information. The fourth region information includes the pipe diameter, the number of 90-degree elbows, the number of 45-degree elbows, the number of straight-through tees, the number of side-out tees, the total number of valves, the number of globe valves, the number of check valves, the number of butterfly valves, the number of angle valves, and the number of different-diameter pipes; the total number of valves is the sum of the number of gate valves, the number of ball valves, and the number of plug valves;

[0353] Substitute the fourth region information into Equation (4) to calculate the equivalent length Le of the circulation pump;

[0354] Equation (4) includes:

[0355] Le = D / 1000 × (35 × the number of 90-degree elbows + 16 × the number of 45-degree elbows + 20 × the number of straight-through tees + 60 × the number of side-out tees + 40 × the total number of valves + 300 × the number of globe valves + 200 × the number of check valves + 40 × the number of butterfly valves + 145 × the number of angle valves + 10 × the number of different-diameter pipes) (4).

[0356] In some embodiments, the first acquisition module 310 is specifically configured to:

[0357] Obtain the real-time value of the container feed temperature of the circulation pump and the second area information;

[0358] Determine the real-time value ρ of the material density of the circulation pump according to the real-time value of the container feed temperature and the second area information.

[0359] In some embodiments, the net positive suction head warning value NPSH satisfies formula (5), and formula (5) includes:

[0360] NPSH = NPSHa - NPSHr - S (5).

[0361] Based on a real-time calculation method for the cavitation state of a circulation pump in a polysilicon production process, a real-time monitoring system for the cavitation state of a circulation pump in a polysilicon production process is given, as Figure 6 shown, including the following modules:

[0362] S501: DCS point collection module, which collects the on-site instrument points including the temperature, pressure of the container feed and discharge (to the circulation pump) and the pump flow rate Q, and obtains their real-time values;

[0363] S502: OPC DA conversion module, which performs OPC DA conversion on all DCS points stored in the DCS point collection module in S501 to generate corresponding OPC points.

[0364] S503: Device identification module, which can formulate device master data identification rules for discriminating device types, and at least includes tank types and separation tower types in this technical solution.

[0365] S504: Device master data database, which stores the device tag number and name, and all the information stored in step S102.

[0366] S505: Chlorosilane component model, which stores the scatter tables of the bubble point component contents of DCS and TCS under the binary interaction of DCS-TCS at different temperatures and pressures and the scatter tables of the bubble point component contents of TCS and STC under the binary interaction of TCS-STC at different temperatures and pressures. This model performs real-time calculation of the component contents of DCS, TCS, and STC according to a real-time calculation method for the components in a container with chlorosilane as the medium in a polysilicon production process.

[0367] S506: Chlorosilane relative density and viscosity model. This model stores the scatter tables of the densities and viscosities of DCS, TCS, and STC at different temperatures. Based on the DCS, TCS, and STC component contents transmitted from the chlorosilane component model described in S505, and according to a real-time monitoring method for the density of chlorosilanes based on the polysilicon production process and a real-time monitoring method for the viscosity of chlorosilanes based on the polysilicon production process, the relative densities and viscosities of DCS, TCS, and STC are calculated in real time.

[0368] S507: Flow rate real-time conversion model. This model receives the real-time values of the pipe diameter D and the OPC point of the flow rate from the main data database of the S504 device, calculates the flow rate in real time, and transmits it to the downstream.

[0369] S508: Reynolds number Re and friction coefficient λ real-time conversion model. This model stores the scatter tables of the friction coefficient λ in the smooth zone and transition zone of the hydraulic pipe under different Reynolds numbers Re and different relative roughnesses. Based on the relative densities and viscosities of DCS, TCS, and STC transmitted from the S506 chlorosilane relative density and viscosity model and the flow rate transmitted from the S507 flow rate real-time conversion model, according to the steps described in S105 and S106, the Reynolds number Re and the friction coefficient λ are calculated and transmitted in real time.

[0370] S509: Equivalent length real-time calculation model. This model receives the quantities of each pipe fitting from the main data database of the S504 device and calculates and transmits the equivalent length value in real time according to the content of S107.

[0371] S510: Inlet pipeline resistance drop H ls Real-time conversion model. This model receives the friction coefficient λ obtained from the S508 Reynolds number Re and friction coefficient λ real-time conversion model, the pipeline length from the main data database of the S504 device, all other pressure drops, and the equivalent length obtained from the S509 equivalent length real-time calculation model. According to S108 and S109, the frictional pressure drop P is calculated in real time mo and further calculates the inlet pipeline resistance drop H in real time ls .

[0372] S511: Net positive suction head value NPSHa real-time conversion model. This model receives the inlet pipeline resistance drop H obtained from the S510 inlet pipeline resistance drop H ls real-time conversion model ls , and the real-time value of the container liquid level provided by the main data database of the S504 device and the height from the zero point of the container liquid level to the pump inlet. According to S110 and S111, the net positive suction head value NPSHa is calculated in real time.

[0373] S512: Conversion model for the actual monitored value of the net positive suction head (NPSH). This model receives the NPSHa obtained from the real-time conversion model of the NPSHa in S511, as well as the required net positive suction head and safety margin of the pump provided by the main data database of the S504 device, and calculates the actual monitored value of the NPSH according to step S112.

[0374] S513: Real-time monitoring terminal for the cavitation state of the pump. This terminal displays all the information provided by the main data database of the S504 device, as well as the real-time values of all the original points in S502 and the real-time values of the process variables among S503 to S512, including the material density, viscosity, composition, and actual monitored value of the net positive suction head. It can also view the historical values of the above points. In addition, it also displays the cavitation alarm information brought by the S514 alarm module.

[0375] S514: Alarm interface module for the net positive suction head (NPSH) value. Based on the real-time value of the NPSH, this module allows users to independently design alarm rules such as the alarm upper limit of the NPSH value and provides a data alarm interface for front-end developers to use.

[0376] Based on a real-time calculation method for the cavitation state of a circulating pump based on the polysilicon production process, a real-time monitoring device for the cavitation state of a circulating pump based on the polysilicon production process (i.e., a device for determining the cavitation margin warning value) is given. As Figure 7 shown, it specifically includes:

[0377] S601: Field instrument layer, which involves the temperature, pressure of the container inlet and outlet (to the circulating pump), and the flow rate Q measurement point of the pump, all of which belong to the field instrument measurement points;

[0378] S602: DCS system layer, which acquires the instrument measurement points described in step S601 and generates DCS points. At the same time, it provides an interface for DCS to connect to OPC for the OPC DA layer.

[0379] S603: OPC DA system layer, which acquires the real-time values of the DCS points described in step S602 and generates OPC points. At the same time, it provides an interface for connecting to OPC for the core database to which S606 belongs.

[0380] Optionally, the conversion of DCS points to OPC DA points can use KEPServer or OPC Client.

[0381] It should be noted that Figure 7 the S603 shown only displays the OPC DA system of one unit, but the OPC DA system layer needs to be adjusted according to the actual situation. Usually, OPC Servers need to be configured at the industrial control system layer and the visualization layer outside the industrial control, so there is more than one. Therefore, Figure 7The OPC DA system shown above represents all of the above, without considering the impact of firewalls and domain allocation issues.

[0382] S604: Device master data database, storing all pump information described in step S102.

[0383] S605: Core database, used to store the real-time values of OPC DA points obtained from step S603 and convert them into PI points, mainly stored in the form of time-series data.

[0384] S606: The core database comes with a modeling backend function. This function mainly performs point conversion through a certain logic, and the most commonly used function is the formula function. In addition, the unary linear interpolation and binary linear interpolation functions make up for the defects in adapting to the content of external databases.

[0385] S607: The core database comes with a frontend function, used to display the real-time and historical values of the target points in the core database.

[0386] S608: Cavitation alarm data interface, which outputs an alarm according to the situation where the upper limit of the cavitation margin alarm designed by the user is exceeded, generates a data interface for the frontend development of developers and the alarm push for users.

[0387] The cavitation margin warning value determination device provided in the embodiment of the present application can be used to execute the cavitation margin warning value determination method in Embodiment 1, that is, it has the beneficial effects and implementation manners of the cavitation margin warning value determination method provided in Embodiment 1 of the present application. Specifically, reference can be made to the specific description of the cavitation margin warning value determination method in the above Embodiment 1, and this embodiment will not be elaborated here.

[0388] Embodiment 4

[0389] The embodiment of the present application provides a cavitation state monitoring system, which can be applied to the circulating pumps in the polysilicon production process. The system includes:

[0390] The cavitation margin warning value determination device of Embodiment 3, used to determine the cavitation margin warning value NPSH of the circulating pump;

[0391] A display device, connected to the cavitation margin warning value determination device, used to visually display the cavitation margin warning value NPSH to achieve the monitoring of the cavitation state.

[0392] The cavitation state monitoring system provided in the embodiment of the present application can be used to execute the cavitation state monitoring method in Embodiment 2, that is, it has the beneficial effects and implementation manners of the cavitation state monitoring method provided in Embodiment 2 of the present application. Specifically, reference can be made to the specific description of the cavitation state monitoring method in the above Embodiment 2, and this embodiment will not be elaborated here.

[0393] It is understandable that the above embodiments are merely exemplary embodiments adopted to illustrate the principle of the present application. However, the present application is not limited thereto. For those of ordinary skill in the art, various modifications and improvements can be made without departing from the spirit and essence of the present application, and these modifications and improvements are also regarded as the protection scope of the present application.

Claims

1. A method for determining the cavitation margin warning value, characterized in that, A circulating pump applied to the polysilicon production process, the method comprising: Obtaining the net positive suction head available (NPSHa) of the circulating pump and the first region information, the net positive suction head available (NPSHa) being determined according to the second region information; the first region information includes a safety margin (S) and the required net positive suction head (NPSHr); the second region information includes the real-time value of the container discharge temperature, the real-time value of the dichlorosilane component content, the real-time value of the trichlorosilane component content, and the real-time value of the silicon tetrachloride content; Determining the cavitation margin warning value (NPSH) of the circulating pump according to the net positive suction head available (NPSHa) and the first region information.

2. The method according to claim 1, characterized in that, Obtaining the net positive suction head available (NPSHa) of the circulating pump, specifically including: Obtaining the target bubble point pressure of the circulating pump at different temperatures; the target bubble point pressure is the bubble point pressure of any two of dichlorosilane, trichlorosilane, and silicon tetrachloride; Determining the saturated vapor pressure (Pv) according to the target bubble point pressure; Determining the net positive suction head available (NPSHa) of the circulating pump according to the saturated vapor pressure (Pv).

3. The method according to claim 2, wherein The obtaining of the target bubble point pressure of the circulating pump at different temperatures specifically includes: Obtaining the target bubble point pressure of the circulating pump at different temperatures through simulation software.

4. The method according to claim 2, wherein The determining of the net positive suction head available (NPSHa) of the circulating pump according to the saturated vapor pressure (Pv) specifically includes: Obtain the local atmospheric pressure P0, gravitational acceleration g, the discharge pressure P of the circulation pump vs , the real-time value ρ of the material density, and the inlet pipeline resistance drop H ls , the height H1 from the zero point of the container liquid level to the pump inlet and the real-time value H2 of the container liquid level; Based on the local atmospheric pressure P0, the acceleration due to gravity g, the discharge pressure P vs , the real-time value of the material density ρ, the resistance drop H of the inlet pipeline ls , the height H1 from the zero point of the container liquid level to the pump inlet, the real-time value H2 of the container liquid level, and the saturated vapor pressure Pv, determine the net positive suction head available NPSHa of the circulation pump.

5. The method according to claim 4, wherein The net positive suction head available (NPSHa) satisfies formula (1); Formula (1) includes: NPSHa = (P vs + P0 / 1000 - Pv) × 100000 / ρg + H1 + H2 - H ls (1).

6. The method according to claim 4, wherein Obtain the inlet pipeline resistance drop H of the circulating pump ls , specifically including: Obtain the real-time value P of the gravitational acceleration g and the frictional pressure drop of the circulation pump mo , the relative density γ of the material and all other pressure drops; all other pressure drops include all pressure drops except the initial value of the control valve pressure drop, the heat exchanger pressure drop, the reactor pressure drop, the filter pressure drop, the orifice plate pressure drop, other pressure drops and the variable pressure drop of the pipeline Substitute the gravitational acceleration g, the real-time value P of the frictional pressure drop mo , the relative density γ of the material, and all other pressure drops into Equation (2) to calculate the inlet pipeline resistance drop H ls ; Formula (2) includes: H ls = (P mo + all other pressure drops) / g / γ (2).

7. The method according to claim 6, wherein Obtain the real-time value P of the frictional pressure drop of the circulating pump mo , specifically including: Obtaining the equivalent length (Le) of the circulating pump, the real-time value of the friction coefficient (λ), the flow rate (Q), the real-time value of the material density (ρ), the third region information, and the fluid velocity (Vs), the third region information includes the total number of different-diameter pipes and pipe orifices, and the pipeline length (L); Substitute the equivalent length Le, the real-time value of the friction coefficient λ, the flow rate Q, the real-time value of the material density ρ, the third region information, and the fluid velocity Vs into formula (3) to calculate the real-time value P of the friction pressure drop of the circulating pump mo ; Formula (3) includes: P mo = (λ(Le + L) / D + sum of reducer and number of pipe orifices) * Vs 2 * ρ / 2 (3).

8. The method according to claim 7, wherein Obtaining the equivalent length (Le) of the circulating pump, specifically including: Obtaining the pipe diameter (D) of the circulating pump and the fourth region information, the fourth region information includes the pipe diameter, the number of 90-degree elbows, the number of 45-degree elbows, the number of straight-through tees, the number of side-out tees, the total number of valves, the number of globe valves, the number of check valves, the number of butterfly valves, the number of angle valves, and the number of different-diameter pipes; the total number of valves is the sum of the number of gate valves, the number of ball valves, and the number of plug valves; Substituting the fourth region information into formula (4) to calculate the equivalent length (Le) of the circulating pump; Formula (4) includes: Le = D / 1000×(35×number of 90-degree elbows + 16×number of 45-degree elbows + 20×number of straight-through tees + 60×number of side-out tees + 40×total number of valves + 300×number of globe valves + 200×number of check valves + 40×number of butterfly valves + 145×number of angle valves + 10×number of different-diameter pipes) (4).

9. The method according to claim 4, characterized in that, Obtaining the real-time value of the material density (ρ) of the circulating pump, specifically including: Obtaining the real-time value of the container feed temperature of the circulating pump and the second region information; Determining the real-time value of the material density (ρ) of the circulating pump according to the real-time value of the container feed temperature and the second region information.

10. The method according to claim 1, characterized in that, The cavitation margin warning value (NPSH) satisfies formula (5), formula (5) includes: NPSH = NPSHa - NPSHr - S (5).

11. A cavitation state monitoring method, characterized in that A circulating pump applied to the polysilicon production process, the method comprising: The method for determining the cavitation margin warning value according to any one of claims 1 to 10, determines the cavitation margin warning value NPSH of the circulating pump; Visually display the cavitation margin warning value NPSH to monitor the cavitation state.

12. A device for determining the cavitation margin warning value, characterized in that, Applied to the circulating pump in the polysilicon production process, the device includes: The first acquisition module is used to acquire the cavitation margin NPSHa of the circulating pump and the first area information, and the cavitation margin NPSHa is determined according to the second area information; the first area information includes the safety margin S and the required cavitation margin NPSHr; the second area information includes the real-time value of the container discharge temperature, the real-time value of the dichlorosilane component content, the real-time value of the trichlorosilane component content, and the real-time value of the silicon tetrachloride content; The first determination module is connected to the first acquisition module and is used to determine the cavitation margin warning value NPSH of the circulating pump according to the cavitation margin NPSHa and the first area information.

13. The device according to claim 12, wherein, The first acquisition module is specifically used for: Acquire the target bubble point pressure of the circulating pump at different temperatures; the target bubble point pressure is the bubble point pressure of any two of dichlorosilane, trichlorosilane, and silicon tetrachloride; Determine the saturated vapor pressure Pv according to the target bubble point pressure; Determine the cavitation margin NPSHa of the circulating pump according to the saturated vapor pressure Pv.

14. The device according to claim 13, characterized in that, The first acquisition module is specifically used for: Acquire the target bubble point pressure of the circulating pump at different temperatures through simulation software; And / or The first acquisition module is specifically used for: Obtain the local atmospheric pressure P0, gravitational acceleration g, the discharge pressure P of the circulation pump vs , the real-time value ρ of the material density, the resistance drop H of the inlet pipeline ls , the height H1 from the zero point of the container liquid level to the pump inlet and the real-time value H2 of the container liquid level; Based on the local atmospheric pressure P0, the acceleration due to gravity g, the discharge pressure P vs , the real-time value ρ of the material density, the resistance drop H ls of the inlet pipeline, the height H1 from the zero point of the container liquid level to the pump inlet, the real-time value H2 of the container liquid level, and the saturated vapor pressure Pv, determine the net positive suction head available NPSHa of the circulation pump.

15. A cavitation state monitoring system, characterized in that, Applied to the circulating pump in the polysilicon production process, the system includes: The cavitation margin warning value determination device according to any one of claims 12 to 14 is used to determine the cavitation margin warning value NPSH of the circulating pump; The display device is connected to the cavitation margin warning value determination device and is used to visually display the cavitation margin warning value NPSH to monitor the cavitation state.

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