Tower equipment safety relief evaluation method and system, electronic device and storage medium

Abstract

This invention discloses a method and system for assessing the safety relief of tower equipment. The method includes the following steps: A. Collecting material property data of the inlet and outlet materials of the tower equipment, as well as equipment information. The material property data includes enthalpy. B. Setting the material and equipment parameters and relief parameters of the tower equipment according to the actual on-site process conditions; performing operating condition analysis on the tower equipment to determine the overpressure relief conditions. C. Dividing the calculation models for the relief volume under different relief conditions into three categories: external fire calculation model, inlet valve fully open calculation model, and thermal imbalance calculation model. Calculating the relief volume for each operating condition using these three models. D. Based on the relief volume calculation results, calculating the required safety valve area for each overpressure relief condition based on the safety valve input parameters, and verifying the existing safety valve relief dimensions. This invention can more accurately calculate the relief volume of tower equipment under various overpressure conditions, effectively preventing safety accidents caused by insufficient relief area of ​​the safety valve in tower equipment under overpressure conditions.

Description

Technical Field

[0001] This invention relates to the field of petrochemical safety engineering technology, and in particular to a method and system for assessing the safety release of tower equipment in petrochemical plants. Background Technology

[0002] Pressure relief and flare systems are the last line of defense for petrochemical enterprises, designed to address overpressure accidents under abnormal operating conditions. While the pressure relief and flare system is a small part of the entire chemical plant, it represents a significant potential source of risk. Insufficient pressure relief system capacity can lead to excessive back pressure in the unit that cannot be released in time, causing overpressure leaks and potentially triggering fires or explosions.

[0003] Petrochemical plants have been operating for many years, and due to changes in raw materials and operating conditions, as well as plant modifications, deviations have occurred between actual operating conditions and design conditions. Furthermore, crude calculations of discharge capacity may overlook conditions with large discharge volumes (such as reaction runaway or high-pressure-to-low-pressure situations), leading to inadequate safety valve design and insufficient overpressure protection, posing risks to equipment operation. Currently, safety discharge capacity assessments for petrochemical plants are mostly based on API 521 / API 520 standards for discharge capacity calculation and safety valve verification. However, the inventors have found that petrochemical processes are complex. For tower-type equipment, API 521 only outlines typical overpressure discharge conditions and corresponding discharge capacity calculation principles, neglecting or lacking specific calculation methods for some conditions. Material properties are also not comprehensively considered, resulting in inaccurate analysis results.

[0004] Chinese patent application CN108563809A discloses a method for calculating the release capacity of a liquefied petroleum gas (LPG) storage tank pressure relief system. While this method can effectively protect LPG tanks, it does not comprehensively consider characteristic parameters and operational condition analysis. Therefore, there is an urgent need for a safety release assessment method for tower-type equipment in petrochemical plants. This method would help companies identify release bottlenecks and propose targeted solutions and measures to effectively prevent safety accidents caused by insufficient release area of ​​safety valves in tower equipment under overpressure conditions.

[0005] The information disclosed in this background section is intended only to enhance the understanding of the overall background of the invention and should not be construed as an admission or in any way implying that the information constitutes prior art known to those skilled in the art. Summary of the Invention

[0006] The purpose of this invention is to provide a method and system for assessing the safety release of tower equipment in petrochemical plants, which can more accurately calculate the release amount and effectively prevent safety accidents caused by insufficient release area of ​​safety valves in tower equipment under overpressure conditions.

[0007] To achieve the above objectives, according to a first aspect of the present invention, the present invention provides a method for assessing the safety relief of tower equipment, comprising the following steps: A. Collecting material property data of materials entering and exiting the tower equipment, as well as equipment information, including enthalpy values; B. Setting material and equipment parameters and relief parameters of the tower equipment according to the actual on-site process conditions; performing operating condition analysis on the tower equipment to determine overpressure relief conditions; C. Dividing the relief volume calculation model under different relief conditions into three types: external fire, inlet valve fully open, and thermal imbalance models, and calculating the relief volume for all overpressure conditions of the tower equipment based on the calculation model; D. Based on the relief volume calculation results, calculating the safety valve area required for the relief volume corresponding to each overpressure relief condition based on the safety valve input parameters, and verifying the relief size of existing safety valves.

[0008] Furthermore, in the above technical solution, the physical property data in step A also include: material composition, mass flow rate, gas phase mole fraction, temperature, pressure, latent heat of vaporization, and heat load of the heat exchanger.

[0009] Furthermore, in the above technical solution, the material and equipment parameters of the tower equipment in step B include the feeding drive method, heat exchange method; discharge drive method; drive method of process material in heat exchanger, heat exchange medium, drive method of heat exchange medium, heat load ratio of heat exchanger, etc.

[0010] The venting parameters include the safety valve set pressure and the venting pressure.

[0011] Furthermore, in the above technical solution, the discharge conditions based on the thermal imbalance calculation model in step C include: gas phase outlet blockage, reflux interruption, partial power outage, refrigerant interruption, mid-section circulation shutdown, abnormal heat input, cold feed interruption, power steam interruption, plant-wide power outage, plant-wide water outage, and plant-wide instrument ventilation interruption.

[0012] Furthermore, in the above technical solution, the discharge volume calculation under thermal imbalance conditions can adopt the following model:

[0013]

[0014] Where f is the mass flow rate of feed / discharge, kg / h; h is the enthalpy of feed / discharge, kJ / kg; Q reboiler The heat introduced by the reboiler and intermediate heat exchanger, kJ / h; Q condenser λ represents the heat removed by the condenser and intermediate condenser, in kJ / h; λ represents the latent heat of vaporization of the released material, in kJ / kg; and W represents the amount of gas released, in kg / h.

[0015] Furthermore, in the above technical solution, the discharge volume calculation under external fire conditions can adopt the following model:

[0016] 1) When the storage medium is vaporizable and there is no thermal insulation layer, the specific calculation of the discharge amount is as follows:

[0017] W = 2.55 × 10 5 FA 0.82 / H L Formula (2);

[0018] Where W is the mass discharge flow rate, kg / h; A is the total wetted area, m². 2 H L The latent heat of vaporization under venting conditions is expressed in kJ / kg; F is the correction factor for the outer wall of the container, taken as F = 1.0;

[0019] 2) When the storage medium is vaporizable and has a complete thermal insulation layer, the specific calculation of the discharge amount is as follows:

[0020] W = 2.61 × (650 - t) × λ × A 0.82 / (H L ×do) formula (3);

[0021] Where W is the mass discharge flow rate, kg / h; A is the total wetted area, m². 2 H L λ is the latent heat of vaporization under venting conditions, kJ / kg; λ is the thermal conductivity of the insulation material, kJ / (m×h×℃); do is the thickness of the insulation material, m; t is the venting temperature, ℃.

[0022] 3) When the tower equipment involves a container with a non-wetting surface, the discharge capacity is specifically calculated as follows:

[0023] W = 8.764 × (MP1) 0.5 ×A1×(T w -T) 1.25 / T1 1.1506 Formula (4);

[0024] Where W is the mass discharge flow rate (kg / h); M is the molecular weight; P1 is the discharge pressure (MPaA); and A1 is the outer surface area of ​​the container below 7.62m above the ground (m²). 2 ;T W T1 is the metal wall temperature, K; T2 is the gas temperature, K, T1 = P1 / Pn × Tn; Pn is the normal operating pressure of the gas, MPaA; Tn is the normal operating temperature of the gas, K.

[0025] Furthermore, in the above technical solution, the discharge volume under the fully open inlet valve condition can be calculated using the following model:

[0026] 1) Emissions caused by gas regulating valve malfunction:

[0027] If P2 > P1 / 2, then V = 2763Cv [ΔP(P1+P2) / (G g ·T)] 0.5 Formula (5);

[0028] If P2 ≤ P1 / 2, then V = 2396P1C v / (Gg·T) 0.5 Formula (6);

[0029] 2) Emissions caused by a malfunction in the steam regulating valve:

[0030] If P2 > P1 / 2, then W = 139.7C v [ΔP(P1+P2)] 0.5 / (1+0.0013Δt) formula (7);

[0031] If P2 ≤ P1 / 2, then W = 121.3P1C v / (1+0.0013Δt) formula (8);

[0032] 3) Discharge volume caused by liquid regulating valve malfunction:

[0033] W = 2737Cv(ΔP·G1) 0.5 ; ΔP=P1-P2 Formula (9);

[0034] Where V is the valve's volumetric discharge capacity, in Nm³. 3 / h; W is the valve's mass discharge capacity, kg / h; Cv is the valve's Cv value; Gg is the specific gravity of the gas or steam; G1 is the specific gravity of the liquid; P1 is the pressure upstream of the valve, MPaA; P2 is the safety valve's relief pressure, MPaA; ΔP is the difference between the upstream and relief pressures, MPaA; Δt is the superheat of the steam, K.

[0035] Furthermore, in the above technical solution, the safety valve input parameters in step D may include the discharge volume, discharge temperature, and discharge pressure calculated in step C, and may also include: safety valve correction coefficient, safety valve set pressure, additional back pressure, cumulative back pressure, and safety valve type.

[0036] Furthermore, in the above technical solution, step D, which involves checking the discharge size of the existing safety valve, can be specifically described as follows: taking the maximum required safety valve area and comparing it with the existing safety valve area; if the maximum required safety valve area is greater than the existing safety valve area, then it is determined that the safety valve's discharge capacity is insufficient.

[0037] According to a second aspect of the present invention, the present invention provides a tower equipment safety relief assessment system, comprising: a data acquisition module for acquiring material property data of materials entering and exiting the tower equipment and equipment information, the material property data including enthalpy; a parameter setting module for setting material and equipment parameters and relief parameters of the tower equipment according to the actual process conditions on site; a working condition analysis module for performing working condition analysis on the tower equipment to determine overpressure relief working conditions; a relief volume calculation module for classifying the relief volume calculation model under different relief working conditions into three types of models: external fire, inlet valve fully open, and thermal imbalance, and calculating the relief volume for each overpressure working condition; and a safety valve verification module for calculating the safety valve area required for the relief volume corresponding to each overpressure relief working condition based on the relief volume calculation results and the safety valve input parameters, and verifying the relief size of existing safety valves.

[0038] According to a third aspect of the present invention, the present invention provides a tower equipment safety leakage assessment electronic device, comprising: at least one processor; and a memory communicatively connected to the at least one processor; wherein the memory stores instructions executable by the at least one processor, the instructions being executed by the at least one processor to cause the at least one processor to perform a method as described in any of the above technical solutions.

[0039] According to a fourth aspect of the present invention, the present invention provides a non-transitory computer-readable storage medium storing computer-executable instructions for causing a computer to perform a tower equipment safety release assessment method as described in any of the above technical solutions.

[0040] Compared with the prior art, the present invention has one or more of the following beneficial effects:

[0041] 1) Based on the special characteristics of tower-type equipment, this invention collects the enthalpy values ​​from the physical property data of the incoming and outgoing materials, and uses the enthalpy values ​​as basic physical property parameters to calculate the release amount under thermal imbalance conditions in the subsequent calculation model. It comprehensively considers the changes in material composition and flow rate under the release state, which can make the evaluation results of overpressure release more objective and accurate, while simplifying the calculation process.

[0042] 2) This invention divides the calculation model for overpressure relief of all tower equipment into three categories. The 11 other conditions, excluding external fire and fully open inlet valve, are grouped into one category. Using the thermal imbalance calculation model obtained by the inventor, as well as the external fire calculation model and the fully open inlet valve calculation model, the relief amount is calculated for the corresponding overpressure conditions using different calculation models. This simplifies the calculation while ensuring the accuracy of the relief amount calculation.

[0043] The above description is merely an overview of the technical solution of the present invention. In order to better understand the technical means of the present invention and to implement it according to the contents of the specification, and to make the above and other objects, technical features and advantages of the present invention easier to understand, one or more preferred embodiments are listed below and described in detail with reference to the accompanying drawings. Attached Figure Description

[0044] Figure 1 This is a flowchart illustrating the safety release assessment method for tower equipment according to Embodiment 1 of the present invention.

[0045] Figure 2 This is a schematic diagram of the process model of the butene stripping tower in Embodiment 1 of the present invention.

[0046] Figure 3 This is a schematic diagram of the structure of the tower equipment safety release assessment system in Embodiment 2 of the present invention.

[0047] Figure 4 This is a schematic diagram of the structure of the electronic device for assessing the safe release of tower equipment in Embodiment 5 of the present invention. Detailed Implementation

[0048] The specific embodiments of the present invention will now be described in detail with reference to the accompanying drawings, but it should be understood that the scope of protection of the present invention is not limited to the specific embodiments.

[0049] Unless otherwise expressly stated, throughout the specification and claims, the term "comprising" or its variations such as "including" or "comprises" shall be understood to include the stated elements or components without excluding other elements or other components.

[0050] In this document, for ease of description, spatial relative terms such as “below,” “under,” “down,” “above,” “above,” “up,” etc., are used to describe the relationship of one element or feature to another element or feature in the accompanying drawings. It should be understood that spatial relative terms are intended to encompass different orientations of an object in use or operation, in addition to those depicted in the figures. For example, if an object in the figure is flipped, an element described as “below” or “under” another element or feature would be oriented “above” that element or feature. Thus, the exemplary term “below” can encompass both the downward and upward orientations. An object may also have other orientations (rotated 90 degrees or other orientations), and the spatial relative terms used herein should be interpreted accordingly.

[0051] In this document, the terms "first," "second," etc., are used to distinguish two different elements or parts, and are not used to define specific positions or relative relationships. In other words, in some embodiments, the terms "first," "second," etc., can also be used interchangeably.

[0052] The methods, systems, electronic devices, and storage media of the present invention are described in more detail below by way of specific embodiments. It should be understood that the embodiments are merely exemplary and the present invention is not limited thereto.

[0053] Example 1

[0054] like Figure 1 As shown in the figure, this embodiment provides a method for safety release assessment of tower-type equipment in petrochemical plants. The method includes the following steps:

[0055] Step S101: Collect material property data and equipment information for the tower equipment's inlet and outlet. Specifically, the method involved in this embodiment interacts with process flow simulation software, importing the required material and equipment information data through a converged steady-state process model of the tower equipment. The material property data and equipment information may include material composition, mass flow rate, gas phase mole fraction, temperature, pressure, latent heat of vaporization, and heat load of the heat exchanger. The inventors have discovered that tower equipment follows material balance, heat balance, and gas-liquid phase balance, with these three balances influencing and restricting each other. Heat balance is the foundation for achieving material balance and gas-liquid phase balance. During normal operation, the tower's heat and material inlet / outlet must be balanced. When the safety valve releases, the release amount equals the gas phase release caused by accumulated heat. The overpressure release amount of the tower equipment should be determined based on the system's material and heat balance under the release conditions. However, under overpressure conditions, the system is in an unstable state, and various process parameters of the tower equipment will change, making detailed calculations difficult. Currently, existing technologies often use simplified methods to calculate the overpressure release amount of tower equipment under different operating conditions. For example, after the refrigerant in the tower is interrupted, the original phase equilibrium of the material inside the tower is disrupted, and the flow rate and composition of the gas phase at the top of the tower will change significantly. However, the existing specifications for this operating condition provide guidance on the discharge rate as the total amount of gas phase entering the condenser under discharge conditions. Calculations using this method are usually rather simple and crude, and it is difficult to characterize the changes in the material under non-equilibrium conditions. This invention, based on a thermal imbalance discharge rate calculation model, introduces the enthalpy value under discharge conditions, taking into account the changes in the material under discharge conditions, making the discharge rate calculation results more objective and accurate. The process simulation software used in this embodiment can be Aspen HYSYS.

[0056] The following example, using a butene stripping tower actually used in production, illustrates the process of collecting material property data and equipment information in this step.

[0057] This example demonstrates a butene stripping tower used in a high-density polyethylene (HDPE) plant. A steady-state process model of the HPDE plant was constructed and converged using process simulation software (such as Aspen HYSYS) based on the actual operating process of the plant. The plant includes pressure-bearing equipment, categorized by type, primarily including tower equipment, reactor equipment, tank equipment, coolers, and compressor / pump equipment. After the steady-state process model was imported into the system, equipment information related to each type of equipment and material property data were stored within the system. Specifically, the butene stripping tower within the HDPE plant (e.g., Figure 2 The model includes feed stream 10, first discharge stream 8 and second discharge stream 12, butene stripping tower body 1, butene condenser 2, butene reboiler 3, butene pump 4, etc. After the steady-state model is imported, the property data of the materials and equipment related to the butene stripping tower (feed and discharge physical property parameters including material composition, mass flow rate, molecular weight, temperature, pressure, enthalpy, heat load of heat exchanger, etc.) are stored synchronously, as shown in Tables 1 and 2 below.

[0058] Table 1 - Logistics information imported during Aspen model import

[0059]

[0060] Table 2 - Heat load parameters imported into the Aspen model

[0061] heat exchanger Heat load (kW) Butene condenser 2 <![CDATA[Q 冷凝 ]]> Butene Reboiler 3 <![CDATA[Q 再沸 ]]>

[0062] Step S102 involves setting the material and equipment parameters, as well as the venting parameters, of the tower equipment based on the actual on-site process conditions; and performing a working condition analysis on the tower equipment to determine the overpressure venting condition. This step is based on importing the steady-state convergence model constructed in the process simulation software (e.g., Aspen HYSYS) in step S101 into the system of this invention, and then setting parameters in the corresponding tower equipment unit. Parameter settings are divided into two parts: material and equipment parameter settings, and venting parameter settings. Material and equipment parameter settings include, for example, the feed drive method, heat exchange method; discharge drive method; tower heat exchange settings: the drive method of the process material in the heat exchanger, the heat exchange medium, the drive method of the heat exchange medium, the heat load ratio of the heat exchanger; reflux tank settings, etc. Venting parameter settings include safety valve pressure setting, venting pressure / pressure setting, safety valve type, etc.

[0063] This step still uses the butene stripping tower involved in step S101 as an example to explain the parameter settings in detail.

[0064] 1) Material and equipment parameter settings:

[0065] For the material and equipment parameter settings of the tower equipment, the drive type for boundary materials and heat exchange materials can be set under the tower equipment unit. The main purpose of setting the drive type is to provide the basis for the system to determine whether the material flow should stop during operation analysis. The drive types for feed / discharge material settings include electric driven compressor, steam turbine driven compressor, electric driven pump, steam turbine driven pump, differential pressure, etc. The drive methods for the feed and discharge materials of the butene stripping tower in this example are shown in Table 3. The heat exchange medium in the heat exchanger of the butene stripping tower is shown in Table 4.

[0066] Table 3 - Butene Stripping Tower Inlet / Outlet Material Driving Mode

[0067] materials Material-driven approach Feed 10 Differential pressure transmission First discharge 8 Differential pressure transmission Second discharge 12 Electric pump

[0068] Table 4 - Heat exchange medium for butene stripping tower

[0069] heat exchanger heat exchange medium Butene condenser 2 Water cooling Butene Reboiler 3 steam

[0070] The tower equipment parameters can include skirt height, diameter, height, reboiler size, reflux tank size, etc. These parameters can be used to calculate the wetting area under fire overpressure conditions in subsequent steps. Please refer to Table 5 for the dimensional parameters of the butene stripping tower.

[0071] Table 5 - Dimensional parameters of butene stripping tower

[0072] Equipment Name Equipment type Equipment elevation diameter Height / Length tower Vertical double end cap <![CDATA[H T ]]> <![CDATA[D T ]]> LT Condenser Horizontal double end cap <![CDATA[H C ]]> <![CDATA[D C ]]> LC reboiler Vertical double end cap <![CDATA[H R ]]> <![CDATA[D R ]]> LR

[0073] 2) Relief parameter settings: including but not limited to safety valve set pressure, relief pressure / set pressure, safety valve type, etc.

[0074] Furthermore, the tower equipment operating conditions in this step are preset within the safety relief assessment system of this invention. For tower equipment, there are a total of 13 relief operating conditions: external fire, inlet valve fully open, gas phase outlet blockage, reflux interruption, partial power outage, refrigerant interruption, mid-section circulation shutdown, abnormal heat input, cold feed interruption, power steam interruption, plant-wide power outage, plant-wide water outage, and plant-wide instrument ventilation interruption. Operating condition analysis refers to selecting and determining the overpressure relief operating condition, and calculating the relief amount using different calculation models in subsequent steps.

[0075] Step S103 involves categorizing the different venting conditions into three calculation models: external fire, fully open inlet valve, and thermal imbalance. The venting volume is then calculated for each condition. To improve the accuracy of venting volume calculations, the inventors have divided the 13 overpressure venting conditions of the tower equipment involved in step S102 into three categories, each calculated using a different model. Specifically, the 11 conditions other than external fire and fully open inlet valve are included in the thermal imbalance model for venting volume calculation. The venting flow rate, molecular weight, venting temperature, and venting pressure under the selected overpressure venting condition can be calculated by combining parameters, equipment, and material data for different conditions. The specific calculation model for each condition is as follows:

[0076] Category 1: Thermal Imbalance

[0077] There are 11 operating conditions: gas phase outlet blockage, reflux interruption, partial power outage, refrigerant interruption, mid-section circulation shutdown, abnormal heat input, cold feed interruption, power steam interruption, plant-wide power outage, plant-wide water outage, and plant-wide instrument ventilation interruption. These 11 operating conditions can be calculated using the following model (i.e., Formula 1). In the aforementioned example, the boundary material information (mass flow rate of feed and discharge, enthalpy, etc.) and equipment information (heat load of reboiler, condenser, etc.) of the butene stripping tower have been synchronously stored in the safety release assessment system of this invention along with the import of the steady-state process model. This invention can automatically determine whether the current material is affected based on the material's driving method and the currently selected release condition type. If the material is stopped, the material flow rate is multiplied by a coefficient of 0 for calculation; if it is unaffected and normal, the material flow rate is multiplied by a coefficient of 1 for calculation.

[0078] The following model is used to calculate the discharge capacity under thermal imbalance conditions:

[0079]

[0080] Where f is the mass flow rate of feed / discharge, kg / h; h is the enthalpy of feed / discharge, kJ / kg; Q reboiler The heat introduced by the reboiler and intermediate heat exchanger, kJ / h; Q condenser λ represents the heat removed by the condenser and intermediate condenser, in kJ / h; λ represents the latent heat of vaporization of the released material, in kJ / kg; and W represents the amount of gas released, in kg / h.

[0081] This invention calculates the discharge amount under thermal imbalance conditions by introducing the parameters of the inlet and outlet enthalpy values ​​and substituting them into the calculation model of formula (1), making the discharge amount calculation under this type of condition more objective and accurate, and more helpful for the subsequent verification of the safety valve size.

[0082] Category 2: External fires

[0083] This invention uses a ground or platform that can store liquid materials as a reference to calculate the heated surface area of ​​a pressure system with a height of less than 7.6m. The formula for calculating the heated surface area of ​​the container (i.e., the total wetted area A) can be found in the "Process Design Specification for Safety Relief Facilities of Petrochemical Plants".

[0084] The following model is used to calculate the discharge capacity under external fire conditions:

[0085] 1) When the storage medium is vaporizable and there is no thermal insulation layer, the discharge capacity can be calculated using the following formula (2):

[0086] W = 2.55 × 10 5 FA 0.82 / H L Formula (2);

[0087] Where W is the mass discharge flow rate, kg / h; A is the total wetted area, m². 2 H L The latent heat of vaporization under venting conditions is expressed in kJ / kg; F is the correction factor for the outer wall of the container, taken as F = 1.0;

[0088] 2) When the storage medium is vaporizable and has a complete thermal insulation layer, the discharge capacity can be calculated using the following formula (3):

[0089] W = 2.61 × (650 - t) × λ × A 0.82 / (H L ×do) formula (3);

[0090] Where W is the mass discharge flow rate, kg / h; A is the total wetted area, m². 2 H L λ is the latent heat of vaporization under venting conditions, kJ / kg; λ is the thermal conductivity of the insulation material, kJ / (m×h×℃); do is the thickness of the insulation material, m; t is the venting temperature, ℃.

[0091] 3) When the tower equipment involves containers with non-wetting surfaces, the discharge capacity can be calculated using the following formula (4):

[0092] W = 8.764 × (MP1) 0.5 ×A1×(T w -T) 1.25 / T1 1.1506 Formula (4);

[0093] Where W is the mass discharge flow rate (kg / h); M is the molecular weight; P1 is the discharge pressure (MPaA); and A1 is the outer surface area of ​​the container below 7.62m above the ground (m²). 2 ;T WT1 is the metal wall temperature, K; T2 is the gas temperature, K, T1 = P1 / Pn × Tn; Pn is the normal operating pressure of the gas, MPaA; Tn is the normal operating temperature of the gas, K.

[0094] Category 3: Inlet valve fully open

[0095] It should be noted that: if the inlet control valve malfunctions and is closed, there is no need to consider overpressure relief measures. However, if the inlet control valve is fully open or partially open when it malfunctions, overpressure relief measures must be considered. In this case, the safety valve discharge capacity should be the difference between the maximum inlet flow rate and the maximum flow rate of the outlet valve in the open state.

[0096] The following model is used to calculate the discharge capacity under the fully open inlet valve condition:

[0097] 1) Emissions caused by gas regulating valve malfunction:

[0098] If P2 > P1 / 2, then V = 2763C v [ΔP(P1+P2) / (G g ·T)] 0.5 Formula (5);

[0099] If P2 ≤ P1 / 2, then V = 2396P1C v / (Gg·T) 0.5 Formula (6);

[0100] 2) Emissions caused by a malfunction in the steam regulating valve:

[0101] If P2 > P1 / 2, then W = 139.7C v [ΔP(P1+P2)] 0.5 / (1+0.0013Δt) formula (7);

[0102] If P2 ≤ P1 / 2, then W = 121.3P1C v / (1+0.0013Δt) formula (8);

[0103] 3) Discharge volume caused by liquid regulating valve malfunction:

[0104] W = 2737Cv(ΔP·G1) 0.5 ; ΔP=P1-P2 Formula (9);

[0105] Where V is the volumetric discharge capacity of the safety valve, in Nm³. 3 / h; W is the mass discharge capacity of the safety valve, kg / h; Cv is the Cv value of the safety valve; Gg is the specific gravity of the gas or steam (compared to air); T is the discharge temperature of the safety valve, K; G1 is the specific gravity of the liquid (compared to water); P1 is the pressure upstream of the valve, MPaA; P2 is the discharge pressure of the safety valve, MPaA; ΔP is the difference between the upstream and discharge pressures, MPaA; Δt is the superheat of the steam, K.

[0106] Step S104: Based on the discharge volume calculation results from step S103, calculate the required safety valve area for each overpressure discharge condition based on the safety valve input parameters, and verify the discharge size of the existing safety valve. This step verifies the safety valve size after calculating the discharge volume for each overpressure condition of the tower equipment.

[0107] Specifically, this invention provides input parameters based on the safety valve throat diameter calculation formula provided in the API 520 standard. Besides parameters such as the discharge volume, discharge temperature, and discharge pressure obtained from the discharge volume calculation as input parameters for safety valve verification calculation, it also requires input of various safety valve correction coefficients, safety valve set pressure, additional back pressure, cumulative back pressure, and safety valve type. Based on the safety valve input parameters, this invention can calculate the safety valve area required for the discharge volume corresponding to each overpressure discharge condition. The maximum required safety valve area is compared with the existing safety valve area. If the maximum required safety valve area is greater than the existing safety valve area, it is determined that the safety valve's discharge capacity is insufficient. Simultaneously, this safety valve area calculation can provide guidance for selecting a replacement safety valve, including the safety valve throat diameter and inlet pipe size.

[0108] Example 2

[0109] Combination Figure 3 As shown, this embodiment provides a tower equipment safety relief assessment system, including a data acquisition module 201, a parameter setting module 202, an operating condition analysis module 203, a relief volume calculation module 204, and a safety valve verification module 205. The data acquisition module 201 is used to collect the physical property data of the materials entering and leaving the tower equipment, as well as equipment information. The physical property data includes enthalpy values. The parameter setting module 202 is used to set the material and equipment parameters and relief parameters of the tower equipment according to the actual process conditions on site. The operating condition analysis module 203 is used to perform operating condition analysis on the tower equipment to determine the overpressure relief conditions. The relief volume calculation module 204 is used to classify the relief volume calculation models under different relief conditions into three types: external fire, inlet valve fully open, and thermal imbalance models, and calculates the relief volume for each condition separately. The safety valve verification module 205, based on the relief volume calculation results and the safety valve input parameters, calculates the safety valve area required for each overpressure relief condition and verifies the relief size of existing safety valves.

[0110] This embodiment 2 is a system embodiment corresponding to the tower equipment safety release assessment method involved in embodiment 1, and can achieve the same technical effect as the method embodiment 1.

[0111] Example 3

[0112] This embodiment provides a non-transient (non-volatile) computer storage medium storing computer-executable instructions. These instructions can execute the tower equipment safety relief assessment method described in the above-mentioned method embodiment and achieve the same technical effect. The method includes the following steps: A. Collecting material property data of the tower equipment's inlet and outlet materials, as well as equipment information. The material property data includes enthalpy. B. Setting the material and equipment parameters and relief parameters of the tower equipment according to the actual on-site process conditions; performing operating condition analysis on the tower equipment to determine the overpressure relief conditions. C. Dividing the relief volume calculation model under different relief conditions into three categories: external fire, inlet valve fully open, and thermal imbalance. Calculating the relief volume for each overpressure condition based on the calculation model. D. Based on the relief volume calculation results, calculating the safety valve area required for each overpressure relief condition based on the safety valve input parameters, and verifying the existing safety valve's relief size.

[0113] Example 4

[0114] This embodiment provides a computer program product, which includes a computer program stored on a non-transitory computer-readable storage medium. The computer program includes program instructions, which, when executed by a computer, cause the computer to execute the tower equipment safety relief assessment method involved in Embodiment 1 above, and achieve the same technical effect. The method includes the following steps: A. Collecting material property data of the inlet and outlet of the tower equipment and equipment information, including enthalpy values; B. Setting the material and equipment parameters and relief parameters of the tower equipment according to the actual process conditions on site; performing operating condition analysis on the tower equipment to determine the overpressure relief conditions; C. Dividing the relief volume calculation model under different relief conditions into three types of calculation models: external fire, inlet valve fully open, and thermal imbalance, and calculating the relief volume for each overpressure condition based on the calculation model; D. Calculating the safety valve area required for the relief volume corresponding to each overpressure relief condition based on the safety valve input parameters according to the relief volume calculation results, and verifying the relief size of the existing safety valve.

[0115] Example 5

[0116] Figure 4This is a schematic diagram of the hardware structure of the tower equipment safety discharge assessment electronic device in Embodiment 5. The device includes one or more processors 610 and a memory 620. Taking one processor 610 as an example, the device may also include an input device 630 and an output device 640.

[0117] The processor 610, memory 620, input device 630 and output device 640 can be connected by a bus or other means.

[0118] The memory 620, as a non-transitory computer-readable storage medium, can be used to store non-transitory software programs, non-transitory computer-executable programs, and modules. The processor 610 executes various functional applications and data processing of the electronic device by running the non-transitory software programs, instructions, and modules stored in the memory 620, thereby implementing the processing method of the above-described method embodiments.

[0119] The memory 620 may include a program storage area and a data storage area, wherein the program storage area may store the operating system and applications required for at least one function; the data storage area may store data, etc. Furthermore, the memory 620 may include high-speed random access memory, and may also include non-transitory memory, such as at least one disk storage device, flash memory device, or other non-transitory solid-state storage device. In some embodiments, the memory 620 may optionally include memory remotely located relative to the processor 610, and these remote memories may be connected to the processing device via a network. Examples of such networks include, but are not limited to, the Internet, corporate intranets, local area networks, mobile communication networks, and combinations thereof.

[0120] Input device 630 can receive input digital or character information and generate signal input. Output device 640 may include display devices such as a display screen.

[0121] The one or more modules are stored in the memory 620. When executed by the one or more processors 610, the following steps are performed: A. Collect material property data of the tower equipment's inlet and outlet materials and equipment information, including enthalpy values; B. Set the material and equipment parameters and venting parameters of the tower equipment according to the actual on-site process conditions; perform operating condition analysis on the tower equipment to determine the overpressure venting conditions; C. Divide the calculation models for venting volume under different venting conditions into three types: external fire, inlet valve fully open, and thermal imbalance. Calculate the venting volume for each overpressure condition based on the calculation models; D. Based on the venting volume calculation results, calculate the safety valve area required for each overpressure venting condition based on the safety valve input parameters, and verify the safety valve's venting capacity.

[0122] The above-described product can execute the methods provided in the embodiments of the present invention, and has the corresponding functional modules and beneficial effects for executing the methods. Technical details not described in detail in this embodiment can be found in the methods provided in other embodiments of the present invention.

[0123] The device embodiments described above are merely illustrative. The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the modules can be selected to achieve the purpose of this embodiment according to actual needs.

[0124] Through the above description of the embodiments, those skilled in the art can clearly understand that each embodiment can be implemented using software plus a general-purpose hardware platform, or of course, using hardware. Based on this understanding, the above technical solutions, in essence or the parts that contribute to the related technology, can be embodied in the form of a software product. This computer software product can be stored in a computer-readable storage medium, such as ROM / RAM, magnetic disk, optical disk, etc., and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute the methods described in the various embodiments or some parts of the embodiments.

[0125] The foregoing description of specific exemplary embodiments of the present invention is for illustrative and explanatory purposes. These descriptions are not intended to limit the invention to the precise forms disclosed, and it will be apparent that many changes and variations can be made in accordance with the foregoing teachings. The exemplary embodiments were chosen and described in order to explain the specific principles of the invention and its practical application, thereby enabling those skilled in the art to implement and utilize various different exemplary embodiments of the invention, as well as various different choices and variations. Any simple modifications, equivalent changes, and alterations made to the foregoing exemplary embodiments should fall within the scope of protection of the present invention.

Claims

1. A method for assessing the safety release of tower equipment, characterized in that, Includes the following steps: A. Collect material property data of materials entering and exiting the tower equipment, as well as equipment information, including enthalpy values; B. Set the material and equipment parameters and discharge parameters of the tower equipment according to the actual process conditions on site; conduct operating condition analysis on the tower equipment to determine the overpressure discharge conditions; C. The calculation models for the discharge volume under different discharge conditions are divided into three categories: external fire, inlet valve fully open, and thermal imbalance. Discharge volume is calculated separately for each overpressure condition. The discharge conditions based on the thermal imbalance calculation model in step C include: gas phase outlet blockage, reflux interruption, partial power outage, refrigerant interruption, intermediate circulation shutdown, abnormal heat input, cold feed interruption, power steam interruption, plant-wide power outage, plant-wide water outage, and plant-wide instrument ventilation interruption. The discharge volume calculation model based on thermal imbalance is as follows: Official (1); where f is the mass flow of the feed / discharge, kg / h; h is the enthalpy of the feed / discharge, kJ / kg; Q reboiler Qin is the heat brought in by the reboiler, intermediate heat exchanger, kJ / h; Q condenser Qout is the heat taken away by the condenser, intermediate condenser, kJ / h; λ is the latent heat of vaporization of the bleed material, kJ / kg; W is the amount of gas bled, kg / h; D. Based on the discharge volume calculation results, calculate the required safety valve area for each overpressure discharge condition based on the safety valve input parameters, and verify the discharge size of the existing safety valve.

2. The tower equipment safety release assessment method according to claim 1, characterized in that, The physical property data in step A also include: material composition, mass flow rate, gas phase mole fraction, temperature, pressure, latent heat of vaporization, and heat load of the heat exchanger.

3. The tower equipment safety release assessment method according to claim 1, characterized in that, The material and equipment parameters of the tower equipment in step B include the feeding drive method, heat exchange method; discharge drive method; drive method of process material in heat exchanger, heat exchange medium, drive method of heat exchange medium, and heat load ratio of heat exchanger; the relief parameters include safety valve set pressure and relief pressure.

4. The tower equipment safety release assessment method according to claim 1, characterized in that, The following model is used to calculate the discharge volume under the external fire condition: 1) When the storage medium is vaporizable and there is no thermal insulation layer, the specific calculation of the discharge amount is as follows: W = 2.55 × 10 5 FA 0.82 / H L Official (2); Where W is the mass discharge flow rate, kg / h; A is the total wetted area, m². 2 H L The latent heat of vaporization under venting conditions is expressed in kJ / kg; F is the correction factor for the outer wall of the container, taken as F=1.0; 2) When the storage medium is vaporizable and has a complete thermal insulation layer, the specific calculation of the discharge amount is as follows: W = 2.61 × (650 - t) × λ × A 0.82 / (H L ×do) formula (3); Where W is the mass discharge flow rate, kg / h; A is the total wetted area, m². 2 ; H L λ is the latent heat of vaporization under venting conditions, kJ / kg; λ is the thermal conductivity of the insulation material, kJ / (m×h×℃); do is the thickness of the insulation material, m; t is the venting temperature, ℃. 3) When the tower equipment involves a container with a non-wetting surface, the discharge capacity is specifically calculated as follows: W = 8.764 × (MP1) 0.5 ×A1×(T w -T) 1.25 / T1 1.1506 Official (4); Where W is the mass discharge flow rate (kg / h); M is the molecular weight; P1 is the discharge pressure (MPaA); and A1 is the outer surface area of ​​the container below 7.62m above the ground (m²). 2 ; T W T1 is the metal wall temperature, K; T2 is the gas temperature, K, T1 = P1 / Pn × Tn; Pn is the normal operating pressure of the gas, MPaA; Tn is the normal operating temperature of the gas, K.

5. The tower equipment safety release assessment method according to claim 1, characterized in that, The following model is used to calculate the discharge capacity under the fully open inlet valve condition: 1) Emissions caused by gas regulating valve malfunction: If P2 > P1 / 2, then V = 2763C v [ΔP(P1+P2) / (G g ·T)] 0.5 Formula (5); If P2 ≤ P1 / 2, then V = 2396P1C v / (Gg·T) 0.5 Formula (6); 2) Emissions caused by a malfunction in the steam regulating valve: If P2 > P1 / 2, then W = 139.7C v [ΔP(P1+P2)] 0.5 / (1+0.0013Δt) formula (7); If P2 ≤ P1 / 2, W = 121.3 P1C v / (1+0.0013Δt) formula (8); 3) Discharge volume caused by liquid regulating valve malfunction: W=2737Cv(ΔP·G1) 0.5 ; ΔP=P1-P2 formula (9); Where V is the valve's volumetric discharge capacity, in Nm³. 3 / h; W is the valve's mass discharge rate, kg / h; Cv is the valve's Cv value; Gg is the specific gravity of the gas or steam; T is the safety valve's discharge temperature, K; G1 is the specific gravity of the liquid; P1 is the pressure upstream of the valve, MPaA; P2 is the safety valve's discharge pressure, MPaA; ΔP is the difference between the upstream and discharge pressures, MPaA; Δt is the superheat of the steam, K.

6. The tower equipment safety release assessment method according to claim 1, characterized in that, The safety valve input parameters in step D include the discharge volume, discharge temperature, and discharge pressure calculated in step C, and also include: safety valve correction coefficient, safety valve set pressure, additional back pressure, cumulative back pressure, and safety valve type.

7. The tower equipment safety release assessment method according to claim 6, characterized in that, The specific steps in step D of verifying the discharge size of the existing safety valve are as follows: Take the maximum required safety valve area and compare it with the existing safety valve area. If the maximum required safety valve area is greater than the existing safety valve area, then the safety valve is judged to have insufficient discharge capacity.

8. A safety release assessment system for tower equipment, characterized in that, The method described in any one of claims 1 to 7 includes: The data acquisition module is used to collect the physical property data of the materials entering and exiting the tower equipment, as well as equipment information. The physical property data includes enthalpy values. The parameter setting module is used to set the material and equipment parameters and discharge parameters of the tower equipment according to the actual process conditions on site. The operating condition analysis module is used to perform operating condition analysis on the tower equipment and determine the overpressure relief operating condition. The discharge capacity calculation module is used to classify the discharge capacity calculation models under different discharge conditions into three types: external fire, inlet valve fully open, and thermal imbalance, and to calculate the discharge capacity for each overpressure condition separately. The safety valve verification module calculates the required safety valve area for each overpressure relief condition based on the relief volume calculation results and the safety valve input parameters, and verifies the relief size of the existing safety valve.

9. An electronic device for assessing the safety release of tower equipment, characterized in that, include: At least one processor; as well as A memory communicatively connected to the at least one processor; wherein, The memory stores instructions that can be executed by the at least one processor to cause the at least one processor to perform the tower equipment safety release assessment method as described in any one of claims 1 to 7.

10. A non-transitory computer-readable storage medium, characterized in that, The non-transitory computer-readable storage medium stores computer-executable instructions for causing the computer to perform the tower equipment safety release assessment method as described in any one of claims 1 to 7.

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