A method for creating a dynamic threshold value of production system status risk

Abstract

The present invention belongs to the field of dynamic hazard early warning and safety prevention and control of production systems, and is specifically a method for creating a dynamic threshold value of the state hazard of a production system. The method comprises the following steps: S100: checking the layout structure of the production system, judging the time domain response type of the production system change, wherein the time domain response type includes a hysteresis response with a time delay effect, a viscosity response with a space delay effect, and a hysteresis + viscosity combination response with both time and space delay effects; S200: calculating and determining the time lag parameter of the production system state change; S300: calculating the dynamic threshold value of the production system state according to the time lag parameter; S400: calculating the distance between the dynamic threshold value of the state of the production system and the critical value of the hazard of the state of the production system, and standardizing the distance; S500: calculating the dynamic threshold value of the state hazard of the production system according to the distance after standardization.

Description

Technical Field

[0001] The present invention belongs to the field of dynamic risk early warning and safety prevention and control of production systems, and specifically is a method for creating a dynamic threshold value of the risk level of a production system state. Background Art

[0002] The hazard threshold is an important parameter for dynamic hazard assessment and early warning of production systems. When the hazard assessment result of the production system status is greater than the hazard threshold, an early warning should be issued immediately and safety control measures should be implemented. Therefore, conducting research on the hazard threshold of the production system status can select scientific and reasonable control opportunities for production accident prevention and control, which is of great significance to ensuring production safety.

[0003] In the current research and application of production system safety management, the setting of hazard thresholds is mostly determined based on experience or experimental test results, which guides production safety to a certain extent. However, the current setting of the state danger threshold still has three shortcomings: First, the critical value of the state danger or the product of the critical value and a certain safety factor (less than 1) is basically set as the danger threshold. This setting method ignores the influence of the time lag effect of time or space delay on safety regulation, which often leads to a delay in the selection of the regulation timing. Even if the regulation measures are implemented, the danger still exceeds the critical value and causes production system failure or production accident; second, most of the danger thresholds are set to the same value. However, different production system structures and different types of regulation activities have different time lag parameters such as time or space delay and change rate. The same danger threshold is difficult to cope with different time lag parameter changes and cannot solve the time lag effect problem; third, the danger threshold is often set to a constant that is only related to the distance. However, the danger of the state is not only affected by the single factor of distance, but also by the change rate and direction of the state. At different times, the distance between the state and the critical value is different. The change rate of the state is different for regulation activities of different intensities. The danger threshold set as a constant "remains unchanged in response to changes" and is difficult to reflect the coupling influence of parameters such as distance, change rate, direction, etc. of different time states on the size of the danger. Therefore, the existing state hazard threshold setting method is difficult to meet the needs of reasonable regulation timing selection. It is urgent to develop a dynamic hazard threshold that matches the changing parameters and time lag parameters of the production system state to provide theoretical and technical support for dynamic hazard warning and safety prevention and control of the production system. Summary of the invention

[0004] In order to solve the problems that the existing hazard threshold cannot cope with the time lag effect, the one-sidedness of the hazard threshold calculation result due to only using the distance indicator, and the hazard threshold set as a constant cannot reflect the impact of regulatory activities at different times and with different intensities on the hazard, the present invention provides a method for creating a dynamic threshold of the hazard level of a production system status.

[0005] The present invention adopts the following technical scheme: a method for creating a dynamic threshold value of the dangerousness of the state of a production system, comprising the following steps, S100: checking the layout structure of the production system, and determining the time domain response type of the change of the production system, wherein the time domain response type includes a hysteresis response with a time delay effect, a viscous response with a space delay effect, and a hysteresis + viscous combination response with both time and space delay effects; S200: calculating and determining the time lag parameter of the change of the state of the production system; S300: calculating the dynamic threshold value of the state of the production system according to the time lag parameter; S400: calculating the distance between the dynamic threshold value of the state of the production system and the critical value of the dangerousness of the state of the production system, and standardizing the distance; S500: calculating the dynamic threshold value of the dangerousness of the state of the production system according to the standardized distance.

[0006] In step S100,

[0007] S101: Calculate the distance between the workstation for controlling the state of production activities in the production system and the workstation where the state monitoring sensor of the production system is located. When the distance is greater than 50m, the state change of the production system has a time delay effect, and the time domain response type of the state change of the production system is determined to be a hysteresis response.

[0008] S102: Analyze the relationship between the state change of the production system and the spatial structure of the production system. When the state change of the production system is affected by the spatial effect of the production system and has a diffusion form, the state change of the production system has a spatial delay effect, and the time domain response type of the state change of the production system is determined to be a viscous response.

[0009] S103: When the time domain response type of the production system state change has both a hysteresis response and a viscosity response, determine that the time domain response type of the production system state change is a hysteresis+viscosity combined response.

[0010] In step S200, when the production system is a hysteresis response, the time lag parameters include the hysteresis time and the hysteresis rate; when the production system is a viscous response, the time lag parameters include the viscous increase time and the viscous increase rate; when the production system is a hysteresis + viscous combination response, the time lag parameters include the hysteresis time, the hysteresis rate, the viscous increase time and the viscous increase rate.

[0011] The specific calculation process is:

[0012] S201: Continuously record the status values ​​of the production system monitored by sensors without changing the production activities , i =0, 1, 2, …, when the monitoring data satisfies formula (1), the time point at this time is recorded as ;

[0013] (1)

[0014] S202: t At time 0, the control increment of the production activity status is given, and the production system status value monitored by the sensor is continuously recorded. , j = i , i +1, i +2, …, when the monitoring data satisfies formula (2), the time point at this time is recorded as t j = t c ;

[0015] (2)

[0016] S203: Continue to continuously record the production system status monitored by the sensor. When the monitoring data satisfies formula (3), the time point at this time is recorded as t j = t n+ , stop monitoring and recording;

[0017] (3)

[0018] S204: Using monitoring data t 0 and t c Calculate the delay time of production system state changes T c ;

[0019] (4)

[0020] Using monitoring data x ( t 0) and x ( t c ) and hysteresis time T c Calculate the hysteresis rate of state change of production system ;

[0021] (5)

[0022] Using monitoring data t n+ and t c Calculate the sticky time of production system state changes T n+ ;

[0023] (6)

[0024] Using viscosity to increase time T n+ and hysteresis rate Calculate the sticky growth rate of the production system state change ;

[0025] (7)

[0026] In step S300, the state dynamic threshold Divided into state dynamic thresholds of production systems with hysteresis effects , Dynamic threshold of the state of production system with sticky effect and the state dynamic threshold of the production system with hysteresis + viscosity combined effect .

[0027] The specific calculation process of step S300 is:

[0028] S301: Dynamic threshold of the state of the production system with hysteresis effect The calculation formula is:

[0029] (8)

[0030] S302: Dynamic threshold of the state of the production system with sticky effect The calculation formula is:

[0031] (9)

[0032] S303: Dynamic threshold of the state of a production system with a combination of hysteresis and viscosity effects The calculation formula is:

[0033] (10)

[0034] in, is the safety factor, ; a is the critical value of the danger of the production system status. When the production system status reaches a When the system fails or an accident occurs.

[0035] The specific calculation method of the distance normalization process in step S400 is:

[0036] S401: Dynamic threshold of production system status The critical value of the production system status a The distance between , obtained from statistics during the long-term operation of the production system hThe distance between the state of the production system in the group data and its critical value is , h =0, 1, 2, …, r ,right Perform translation and standard deviation transformation:

[0037] (11)

[0038] (12)

[0039] S402: Perform translation and range transformation;

[0040] (13)

[0041] make , the distance between the dynamic threshold of the production system state after standardization and its critical value of danger is , .

[0042] In step S500, the dynamic threshold of the danger level of the production system status is for:

[0043] (14)

[0044] In the formula, is the real-time rate of change of the production system status; The real-time change direction of the production system status.

[0045] Compared with the prior art, the present invention has the following beneficial effects:

[0046] According to the changing rules of the production system state after the production system structure layout and production activity state regulation, the present invention defines three different time domain response types of production system state changes, and provides a determination method for each response type.

[0047] The dynamic threshold of the production system state danger degree takes into account the influence of time-lag parameters such as hysteresis time, hysteresis rate, viscosity increase time and viscosity increase rate of the production system state change after the implementation of the control measures on the threshold setting, which can effectively deal with the problem of delayed control measures caused by the time lag effect caused by the production system structure and state characteristics;

[0048] Based on the consideration of the impact of the real-time distance between the state danger level and its critical value on the threshold setting, this method adds the real-time rate and direction of state change as parameters for creating a danger threshold function. This not only solves the problem of one-sidedness in the danger threshold calculation results caused by using only a single indicator, but also the time-varying threshold can change with changes in regulatory activities at different times and intensities, solving the problem that the danger threshold set as a constant cannot "respond to all changes."

[0049] This method organically couples the state time-varying parameters such as the real-time distance between the state dynamic threshold and its critical value that affect the degree of hazard, the real-time change rate, the real-time direction, and the state time-delay parameters such as the hysteresis time, hysteresis rate, viscosity increase time and viscosity increase rate, thereby establishing a dynamic threshold function for the state hazard of the production system, laying a theoretical and technical foundation for the production system to scientifically and rationally select the timing of state regulation. BRIEF DESCRIPTION OF THE DRAWINGS

[0050] Figure 1 The flowchart of the method for creating a dynamic threshold value of the dangerousness of the status of a production system in a specific implementation manner of the present invention. DETAILED DESCRIPTION

[0051] The present invention is further explained in detail below in conjunction with the drawings in the specification so that the advantages and features of the present invention can be more easily understood by those skilled in the art, thereby making a clearer and more definite definition of the protection scope of the present invention.

[0052] See also Figure 1 As shown in the figure, a method for creating a dynamic threshold value of the state danger of a production system is firstly used to determine the time domain response type of the state change of the production system according to the layout structure of the production system, and then the time lag parameters such as the hysteresis time, hysteresis rate, viscosity increase time and viscosity increase rate of the state change of the production system are calculated by monitoring and recording the change data of the state of the production system after the state of the production activity is changed. On this basis, the dynamic threshold value of the state of the production system under the influence of the time lag effect and the distance between it and the critical value of the danger of the state are calculated, and the distance is standardized, and finally a dynamic threshold function of the state danger of the production system is created, which is composed of the state control time lag parameter and the real-time distance between the state dynamic threshold value and its critical value, the real-time change rate, the real-time direction and the coupling relationship between each parameter.

[0053] The specific process is:

[0054] S100: Check the layout structure of the production system and determine the time domain response type of the production system change. The response type can be determined by calculating the distance between the workstation where the production activity state is regulated in the production system and the workstation where the production system state monitoring sensor is located, and analyzing the relationship between the production system state change and the production system space attribute. The time domain response type includes a hysteresis response with a time delay effect, a viscous response with a space delay effect, and a hysteresis + viscous combination response with both time and space delay effects.

[0055] In this embodiment, the specific method for determining the time domain response type of the production system state change is:

[0056] Calculate the distance between the workstation where the production activity status is controlled in the production system and the workstation where the production system status monitoring sensor is located. When the distance is greater than 50m, the state change of the production system has a time delay effect, and the time domain response type of the state change of the production system is determined to be a hysteresis response; for example, when the distance between the position of the water volume regulating valve of the drainage pipe and the position of the flow meter is greater than 50m, the water flow state change has a time delay effect.

[0057] Analyze the relationship between the state change of the production system and the spatial structure of the production system. When the state change of the production system is affected by the spatial effect of the production system and has a diffusion form, the state change of the production system has a spatial delay effect, and the time domain response type of the state change of the production system is determined to be a viscous response; for example, monitor the concentration of methane in space. Since methane is a gas, the concentration of methane is the result of its diffusion in space. Therefore, the state change of methane concentration has a spatial delay effect.

[0058] When the time domain response type of the state change of the production system has both hysteresis response and viscosity response, the time domain response type of the state change of the production system is determined to be a hysteresis + viscosity combination response. For example, there is a pipeline with a length greater than 50m, with a methane release switch at one end of the pipeline for methane injection flow control, and a methane concentration sensor at the other end of the pipeline for methane concentration monitoring. Since the control input end is greater than 50m away from the concentration monitoring end, the distance effect causes the change of methane concentration in the pipeline to have a time delay effect. At the same time, as a gas, the concentration of methane is the result of its diffusion in the pipeline, and the change of methane concentration state has a spatial delay effect. Therefore, the change of methane concentration in the pipeline system has both hysteresis response and viscosity response.

[0059] S200: Calculate and determine the time lag parameters of the production system state change. The time lag parameters include the hysteresis time and hysteresis rate of the hysteresis response and the viscosity increase time and viscosity increase rate of the viscosity response. By monitoring and recording the change data of the production system state after changing the state of the production activity, the time data and real-time state data required for calculating each time lag parameter can be obtained.

[0060] The specific calculation method of each time lag parameter in this embodiment is:

[0061] Continuously record the status values ​​of the production system monitored by sensors without changing the status of production activities , i =0,1, 2, …, when the monitoring data satisfies formula (1), the time point at this time is recorded as ;

[0062] (1)

[0063] exist t At time 0, the control increment of the production activity status is given, and the production system status value monitored by the sensor is continuously recorded. x ( t j ), j = i , i +1, i +2, …, when the monitoring data satisfies formula (2), the time point at this time is recorded as t j = t c ;

[0064] (2)

[0065] Continue to continuously record the status of the production system monitored by the sensor. When the monitoring data satisfies formula (3), the time point at this time is recorded as t j = t n+ , stop monitoring and recording;

[0066] (3)

[0067] Using monitoring data t 0 and t c Calculate the delay time of production system state changes T c As shown in formula (4):

[0068] (4)

[0069] Using monitoring data x ( t 0) and x ( t c ) and hysteresis time T c Calculate the hysteresis rate of state change of production system As shown in formula (5):

[0070] (5)

[0071] Using monitoring data t n+ and t c Calculate the sticky time of production system state changes T n+ As shown in formula (6):

[0072] (6)

[0073] Using viscosity to increase time T n+ and hysteresis rate Calculate the sticky growth rate of the production system state change As shown in formula (7):

[0074] (7).

[0075] S300: Calculate the dynamic threshold of the state of the production system according to the time lag parameter; including the state dynamic threshold of the production system with hysteresis effect, the state dynamic threshold of the production system with viscosity effect, and the state dynamic threshold of the production system with hysteresis + viscosity combined effect. Among them, the state dynamic threshold with hysteresis effect can be calculated using the hysteresis time and the hysteresis rate, the state dynamic threshold with viscosity effect can be calculated using the viscosity increase time and the viscosity increase rate, and the state dynamic threshold with hysteresis + viscosity combined effect can be calculated using the hysteresis time, the hysteresis rate, the viscosity increase time and the viscosity increase rate.

[0076] See also Figure 1 As shown, the specific calculation method of the dynamic threshold value of the various time lag effect production system states in this embodiment is:

[0077] When the time domain response type of the production system state change is a hysteresis response, the state dynamic threshold of the production system with hysteresis effect The calculation formula is shown in formula (8):

[0078] (8)

[0079] in, is the safety factor, ; a is the critical value of the danger of the production system status. When the production system status reaches a When the system fails or an accident occurs.

[0080] When the time domain response type of the production system state change is a sticky response, a state dynamic threshold of the production system with a sticky effect is established. The calculation formula is shown in formula (9):

[0081] (9)

[0082] When the time domain response type of the production system state change is a hysteresis + viscosity combination response, the state dynamic threshold of the production system with hysteresis + viscosity combination effect is established. The calculation formula is shown in formula (10):

[0083] (10)

[0084] S400: Calculate the distance between the state dynamic threshold of the production system and the critical value of the danger of the production system state, and standardize the distance. The standardization of the distance is to first perform a translation and standard deviation transformation on the distance, and then perform a translation and range transformation.

[0085] See also Figure 1 As shown, the specific calculation method for distance normalization processing in this embodiment is:

[0086] make Dynamic thresholds for the status of production systems The critical value of the production system status a The distance between is the first statistical result obtained during the long-term operation of the production system. h The distance between the state of the production system in the group data and its critical value, h =0, 1, 2, …, r ,right The translation and standard deviation transformation is shown in formulas (11) and (12):

[0087] (11)

[0088] (12)

[0089] right The translation range transformation is performed as shown in formula (13):

[0090] (13)

[0091] make , then the distance between the dynamic threshold of the production system state after standardization and its critical value of danger .

[0092] S500: Calculate the dynamic threshold of the danger level of the production system state according to the standardized distance.

[0093] See also Figure 1 As shown, the dynamic threshold of the dangerousness of the production system state in this embodiment is As shown in formula (14).

[0094] (14)

[0095] In the formula, is the real-time rate of change of the production system status; The real-time change direction of the production system status.

[0096] The dynamic threshold of the dangerousness of the production system state is composed of the state control time lag parameter and the real-time distance, real-time change rate, real-time direction between the state dynamic threshold and its critical value, as well as the coupling relationship between various parameters. It is a time-varying value related to the state control time lag parameter and the state time-varying parameter. Therefore, it can not only effectively deal with the problem of delayed control measures caused by the lag effect caused by the structure and state characteristics of the production system, but also change with the changes of control activities at different times and with different intensities, solving the problem that the dangerousness threshold set as a constant cannot "respond to all changes", and can lay a theoretical and technical foundation for the scientific and reasonable selection of the timing of state control in the production system.

Claims

1. A method for creating a dynamic threshold value of a production system state risk, characterized by: The following steps are included: S100: Checking the layout structure of the production system and determining the time domain response type of the production system change, wherein the time domain response type includes a hysteresis response with a time delay effect, a viscosity response with a space delay effect, and a hysteresis + viscosity combination response with both time and space delay effects; In step S100, S101: Calculate the distance between the workstation for controlling the state of production activities in the production system and the workstation where the state monitoring sensor of the production system is located. When the distance is greater than 50m, the state change of the production system has a time delay effect, and determine that the time domain response type of the state change of the production system is a hysteresis response; S102: Analyze the relationship between the state change of the production system and the spatial structure of the production system. When the state change of the production system is affected by the spatial effect of the production system and has a diffusion form, the state change of the production system has a spatial delay effect, and the time domain response type of the state change of the production system is determined to be a viscous response. S103: when the time domain response type of the production system state change has both a hysteresis response and a viscosity response, determining that the time domain response type of the production system state change is a hysteresis+viscosity combined response; S200: Calculate and determine the time lag parameter of the production system state change; In step S200, When the production system has a hysteresis response: the hysteresis parameters include hysteresis time and hysteresis rate; When the production system has a viscous response: the time-lag parameters include the viscous increase time and the viscous increase rate; When the production system is a combination of hysteresis and viscosity response: the hysteresis parameters include hysteresis time, hysteresis rate, viscosity increase time and viscosity increase rate; The specific calculation process of step S200 is: S201: Continuously record the status values ​​of the production system monitored by sensors without changing the status of production activities , i =0, 1, 2, …, when the monitoring data satisfies formula 1, the time point at this time is recorded as ; （1） S202: t At time 0, the control increment of the production activity status is given, and the production system status value monitored by the sensor is continuously recorded. , j = i , i +1, i +2, …, when the monitoring data satisfies Formula 2, the time point at this time is recorded as tj = tc ; （2） S203: Continue to continuously record the production system status monitored by the sensor. When the monitoring data satisfies Formula 3, the time point at this time is recorded as t j = t n+ , stop monitoring and recording; （3） S204: Using monitoring data t 0 and t c Calculate the delay time of production system state changes T c ; （4） Using monitoring data x ( t 0) and x ( tc ) and hysteresis time Tc Calculate the hysteresis rate of state change of production system ; （5） Using monitoring data t n+ and t c Calculate the sticky time of production system state changes T n+ ; （6） Using viscosity to increase time Tn+ and hysteresis rate Calculate the sticky growth rate of the production system state change ; （7） S300: Calculating a dynamic threshold of a production system state according to a time lag parameter; In step S300, the dynamic threshold Divided into state dynamic thresholds of production systems with hysteresis effects , Dynamic threshold of the state of production system with sticky effect and the state dynamic threshold of the production system with hysteresis + viscosity combined effect ; The specific calculation process of step S300 is: S301: Dynamic threshold of the state of the production system with hysteresis effect The calculation formula is: （8） S302: Dynamic threshold of the state of the production system with sticky effect The calculation formula is: （9） S303: Dynamic threshold of the state of a production system with a combination of hysteresis and viscosity effects The calculation formula is: （10） in, is the safety factor, ; a is the critical value of the danger of the production system status. When the production system status reaches a When the system fails or an accident occurs; S400: Calculate the distance between the state dynamic threshold of the production system and the critical value of the danger of the state of the production system, and perform standardization on the distance; The specific calculation method of the distance normalization process in step S400 is: S401: Dynamic threshold of production system status The critical value of the production system status a The distance between , obtained from statistics during the long-term operation of the production system h The distance between the state of the production system in the group data and its critical value is , h =0, 1, 2, …, r ,right Perform translation and standard deviation transformation: （11） （12） S402: Perform translation and range transformation; （13） make , the distance between the dynamic threshold of the production system state after standardization and its critical value of danger is , ; S500: Calculate the dynamic threshold of the danger level of the production system state according to the standardized distance; In step S500, the dynamic threshold of the danger level of the production system status is for: （14） In the formula, is the real-time rate of change of the production system status; The real-time change direction of the production system status.

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