KR102091570B1 - Design method of flare system using dynamic modeling - Google Patents

Abstract

The present invention relates to a design method of a flare system including a pressure relief device, a flare main header, a tail pipe, a knockout drum, and a flare stack. The flare system design method using dynamic modeling comprises the steps of: obtaining a variable value when a Mach number is maximum by performing dynamic modeling by setting a time dependent variable in steady state modeling using an emergency scenario of a flare system; and setting the size of a pipe using the variable value and the Mach number as a design criterion.

Description

Design method of flare system using dynamic modeling}

A flare system design method using dynamic modeling.

Most of the chemical plants are large-scale and consist of various equipment such as compressors, distillation columns, reactors, and vessels. All of this equipment operates under proper operating conditions and has design pressure. However, in a variety of emergencies, such as fires, utility breakdowns, and outlet shutdowns, overpressure may occur and may not work properly. If these equipment are not stabilized immediately, more serious fires and explosions can occur, which can seriously damage human life, property, and the environment. To prevent such accidents or replace existing equipment, most chemical plants are equipped with a Pressure Relief System. It protects various equipment in the process and eliminates overpressure that occurs during normal or abnormal operation of the process. 1 shows a simplified structure of a pressure release system. It includes Pressure Relief Devices, a header and tail pipe that delivers flare loads, a knockout drum that separates liquid before combustion, and a flare stack that safely burns flare gas.

The pressure relief device includes a pressure safety valve (PSV), a blow down valve (BDV) and a rupture disk, which releases fluid inside the equipment to relieve overpressure. The pressure relief valve (PSV) is a device that automatically decompresses an abnormal condition that the operator does not recognize and opens with a spring action when the pressure reaches a specified set pressure. The blow-down valve (BDV) is also a device that performs decompression, but is typically used for manual operation to expel fluid quickly from the vessel for process termination or equipment replacement, and is operated by pneumatic operation. The rupture discs are installed in equipment or devices such as pressure containers, pipes and reactors and are broken to a set pressure during operation to protect the equipment. It is used for one-time use when an abnormal substance accumulates in the pressure relief valve (PSV) or the valve function is impaired or the valve fails to react quickly. The most commonly used device in emergency situations is a pressure relief valve.

It is important to properly install the type, size and number of pressure relief valves for safe decompression depending on the type of pressure relief valve (PSV) and the size of the orifice, flare rod profile and back pressure. The flare gas emitted from the pressure relief device connected to each equipment passes through a tail pipe or sub-header and collects in the main headeer. These main headers pass through a knock out drum (K.O drum) to send fluid to the flare stack. During normal operation, the amount of fluid flowing through the header is small, but in the case of abnormal operation, a large amount of flare rod flows at high pressure and speed. Each tail pipe, sub-header and header has design conditions, and PSV back pressure limit, fluid Mach number and momentum are set by the licensing company. When sizing the pipeline, the most dominant of the emergency scenarios is applied to the model, and the calculation results should not exceed design limits.

In the current oil and gas industry, flare systems are designed in a conventional way and have significant design margins. This can lead to unnecessary waste in terms of capital cost, and an excessively large machine size can increase the space and weight of the entire process. Therefore, in the case of offshore processes that allow limited space and weight, a more rigorous design method is required and no existing design method is required.

In Non-Patent Document 1, a steady state modeling of a pool fire scenario was performed using a completed project, and then PSV back pressure and velocity were analyzed. The results of this study indicate that the diameter of the tail pipe is too small to provide high back pressure to damage PSV in fire scenarios. In addition, it has been disclosed that the high flare rod speeds the tail pipe so high that the diameter of the tail pipe must be increased or split into two pipelines to disperse the flare rod.

In Non-Patent Document 2, the flare network pipeline for cooling water destruction and external fire scenarios was optimized by calculating equations without using modeling. Header back pressure and Mach number restrictions have been proposed, and Mach number and back pressure have been calculated according to the API521 standard using the information provided. After determining the shape of the flare rod and piping line of each source, the diameter of the piping line was recalculated to satisfy the above limit.

However, all of the above studies are the result of steady state.

Most flare systems in existing chemical processes are designed with the prior art with a high design margin based on steady state. In general, these methods analyze the sum of the flare loads collected in the header pipe as shown in Fig. 2 (a) and calculate the size of the header to accommodate all discharge rates from different sources. However, the flare load emitted from the PSV tends to reach the peak momentarily and momentarily and decrease again, as shown in FIG. In addition, the actual cumulative flare load passing through the main header is less than the sum of each flare rod, since there is a time difference emitted from the PSV to which the flare rod is connected at a certain distance. Therefore, it is necessary to design the flare system properly.

 Muktikanta Sahoo, High Back Pressure on Pressure Safety Valves (PSVs) in a Flare System, University of Bergen, Master Thesis, 2013  Siddhartha Mukherjee, Pressure-Relief System Design, CHEMICAL ENGINEERING, Vol. 113, pp40-45, 2008

In order to solve the above-mentioned problems, the present inventors intend to present a flare system design method using dynamic modeling as a marine plant flare system design method for an offshore plant, and reduce the design margin by using the proposed flare system design method. It is possible to derive the pipe size, which is excellent in economic efficiency, and not only to reduce the size, but also to provide technology that can secure the safety of the process by accurately predicting the actual behavior of the process in an emergency.

The purpose of another aspect of the present invention is to analyze the difference between steady state modeling and dynamic modeling and propose to introduce a new method when designing a flare system in the future using the analysis.

In order to achieve the above object, in one aspect of the present invention

With the design method of flare system including pressure relief device, flare main header, tail pipe, knockout drum and flare stack,

Steps to obtain a variable value when the Mach number is maximum by performing dynamic modeling by setting a time dependent variable in steady state modeling using an emergency scenario of the flare system ; And

A method of designing a flare system using dynamic modeling is provided, comprising: setting the size of a pipe using the variable value and the Mach number as a design criterion.

The flare system design method using dynamic modeling provided in one aspect of the present invention can secure economic efficiency and safety by optimizing the size of pipes applied to the flare system.

1 is a schematic view showing an example of a pressure release system;
2 is a graph (a) analyzing the sum of flare rods collected in the header pipe and a graph (b) showing the amount of flare rods emitted over time;
3 and 4 are schematic views showing an example of a flare system;
5 is a graph showing changes occurring over time in a high pressure equilibrium separator by performing dynamic modeling;
6 is a graph showing the amount and back pressure of flare rods generated over time of pressure relief valves PSV-A, PSV-B, and PSV-C by performing dynamic modeling;
FIG. 7 is a graph showing changes in Mach number over time of pipes 5 and 5 in FIG. 3 and changes in mass flow rate and pressure;
8 is a graph showing a comparison of Mach numbers calculated by steady state modeling and dynamic state modeling;
FIG. 9 is a schematic diagram incorporating the results of FIG. 8 into the system;
10 is a graph comparing pipe diameters calculated by steady state modeling and dynamic state modeling;
FIG. 11 is a schematic diagram in which the results of FIG. 10 are combined into a system.

In one aspect of the invention

With the design method of flare system including pressure relief device, flare main header, tail pipe, knockout drum and flare stack,

Steps to obtain a variable value when the Mach number is maximum by performing dynamic modeling by setting a time dependent variable in steady state modeling using an emergency scenario of the flare system ; And

A method of designing a flare system using dynamic modeling is provided, comprising: setting the size of a pipe using the variable value and the Mach number as a design criterion.

Hereinafter, a method for designing a flare system using dynamic modeling provided in one aspect of the present invention will be described in detail.

First, the flare system design method using dynamic modeling provided in one aspect of the present invention is dynamic modeling by setting a time dependent variable in steady state modeling using an emergency scenario of the flare system. modeling) to obtain a variable value when the Mach number is the maximum.

The flare system is a general flare system, and may include a pressure release device, a flare main header, a tail pipe, a knockout drum, and a flare stack. The pressure relief device includes a forced shut-off valve (SDV), a pressure safety valve (PSV), a blow down valve (BDV), a rupture plate, etc., and each pipeline to which the valves are connected. can do.

The release of flare loads is the result of overpressure of the device due to various causes. In particular, thermal expansion, evaporation, etc. occur due to the injection of heat, and the main cause is an increase in pressure or an increase in direct pressure due to injection of a high pressure source. Since the causes of this overpressure are very diverse, the scenarios are separated into several types in advance, and each scenario is applied to the design to check whether safe operation is possible. Categorizing these scenarios into two broad categories is not due to continuous scenarios (e.g., control valve leakage, purge, process venting) and continuous operation, but rather short periods of time. There are emergency scenarios in which the flare rod is released to depressurize. It is desirable to use the emergency scenario because the continuous scenario does not determine the size of the pipe because there is no temporary large flare rod emission. These formal emergency scenarios are provided in API 521.

The emergency scenario applied in the flare system design method using the dynamic modeling provided in one aspect of the present invention is preferably a separator outlet blocked discharge scenario.

The separator outlet blocked discharge scenario is a high pressure separator, which includes a raw material inlet 11 through which raw materials are injected and a raw material outlet 12 through which raw materials are discharged, as shown in FIG. 3. 10); Forced shut-off valve (20, shut down valve; SDV) formed in the pipe connected to the raw material inlet; A pressure safety valve (PSV) 40 formed in a tail pipe 30 connected to the high pressure equilibrium separator; A main header (50, main header) connected to the tail pipe; A knockout drum (60, Knock Out Drum; K.O Drum) separating the liquid from the inflowing components connected to the main header; And a flare stack connected to the knockout drum (70).

At this time, the tail pipe 30 connected to the high-pressure equilibrium separator is at least two, preferably three or more, more preferably four or more. At least two or more tail pipes are positioned in parallel, and each tail pipe may be connected to a main header, and a pressure relief valve may be formed in each tail pipe.

The separator outlet blocked discharge scenario is specifically as follows. The hydrocarbon mixture as a raw material enters the high pressure equilibrium separator 10 of the system 100 of FIG. 3 at a constant pressure and flow rate and is discharged through an outlet 12, and the outlet is closed so that the raw materials inside the high pressure equilibrium separator escape. The internal pressure rises as it fails to accumulate, and accordingly, when a pressure alarm high-high (PAHH) pressure warning is reached, the forced shutoff valve 20 connected to the raw material inlet 11 is activated and completely shut off after about 20 seconds. Even when the forced shut-off valve is closed, when the pressure rises to reach the pressure safety valve set pressure, the pressure safety valve 40 is opened to release a flare load, the tail pipe 30 connected to the pressure safety valve The flare rod is collected through the tail pipe to the main header 50. While moving along the main header and passing through the knockout drum 60, the liquid can be separated and finally burned in the flare stack 70 and released into the air. At this time, the orifice sizes of the pressure safety valves are all the same, but the set pressures may all be different.

The steady-state modeling may be to set factors including initial raw material injection conditions, the size of the separator, the size of the outlet, the size of the forced shutoff valve, the speed at which the forced shutoff valve closes, and the set pressure of the pressure relief valve.

The time-dependent variable set in the dynamic modeling may be a normal operating time of the initial separator and a discharge port of the high-pressure equilibrium separator closed, and a time when the forced shut-off valve closes after reaching a pressure warning of PAHH.

The dynamic modeling may be performed using a gESMS program from PES.

Next, a flare system design method using dynamic modeling provided in one aspect of the present invention includes setting the size of the pipe using the variable value and the Mach number as a design criterion.

As a specific example, the step of setting the size of the pipe using the variable value and the Mach number as a design criterion may be calculated through Equation 1 below.

<Equation 1>

(In the above formula 1,

Ma is the Mach number; q _m is the gas mass flow rate (kg / h); p is the pipe outlet pressure (kPa); d is the pipe inner diameter (m); Z is the compressibility; T is the absolute temperature (K); Mw is gas average molecular weight (g / mol).

The variable value obtained using the dynamic modeling may be a variable value at a time when the Mach number is maximum. As a specific example, the dynamic modeling may be a variable value including flow rate, pressure, temperature, compression coefficient, and average molecular weight of the gas at the time when the Mach number is the maximum. By applying the variable value at the time when the Mach number is the maximum and the Mach number as a design criterion to Equation 1, the size of the pipe can be minimized while satisfying the Mach number limit even under the worst conditions.

In this case, the pipe may be a pipe that connects a pressure release device, a main header, or the like, and may be, for example, a tail pipe formed with a pressure safety valve, a pipe formed on the main header, or the like.

Hereinafter, it will be described in more detail through experimental examples of the present invention.

However, the following experimental examples are only illustrative of the present invention, and the contents of the present invention are not limited by the following examples and experimental examples.

< Example > Flare system dynamic modelling

When designing flare systems in most petrochemical and oil industries, steady-state modeling is used, and programs such as the Aspen flare system analyzer and Aspen hysys are used. In particular, using the AFSA specialized in flare system design, the Mach number, momentum, and noise in the pipe can be calculated and viewed, and it is possible to check whether the set design value is satisfied. However, the process part cannot be modeled at the same time, and if the amount of flare load, set pressure, orifice size, discharge pressure, etc. is directly input to the flare source, the value is changed. Calculate the Mach number, etc. in the connected pipe. However, in the actual production process, the main process part and the flare part are connected, and due to situations such as normal operation, ignition, outlet block, automatic control failure of the main process part, etc. Due to the abnormal high pressure of the process equipment, the flare rod is discharged to the connected flare system. Instead of modeling at the same time, it determines the flare emission scenario due to the phenomenon of the main process part, calculates the amount of flare rod or discharge pressure separately, and does not take into account changes over time. This adds a significant margin to the calculation because it is not possible to design accurately.

Dynamic modeling was performed for the steady state modeled scenario using the gPROMS process builder. Unlike AFSA, the main process parts are modeled together. The above scenario is the most important point of how the pressure of the separator 10 in the main process part changes, and how the pressure relief valves 40 and PSV are opened by the pressure, which can be accurately implemented only through dynamic modeling. Factors affecting the pressure of the separator are initial feed conditions, such as flow rate, temperature, pressure, and composition. In addition, the size of the separator and the forced shut-off valves (20, SDV), closing of the outlet stream, and forced There is a speed at which the shutoff valve closes. First, create a steady state model using initial feed conditions, process configuration, equipment size, PSV set pressure, etc., and then convert to a dynamic model by reflecting time dependent variables using a scheduler. Order. In the scheduler of the dynamic model, an outlet block was implemented by closing the outlet valve after normal operation for about 50 seconds. Accordingly, the pressure of the separator began to increase at the initial value of 14.7 barg, and when the PAHH (20.69 barg) was reached, the forced shutoff valve was set to close for 20 seconds.

Five pressure relief valves are connected to the separator, and the pressure relief valve to reach the set pressure is opened and the fluid compressed inside the separator into the pipeline is discharged as a flare rod. Because this is also dynamic modeling, the flow of the flare rod discharged during the period from the first opening to the closing of the pressure relief valve is not constant. In addition, the tail pipes connected to each pressure safety valve constitute a network and are connected to each other, and the valves open between pressure safety valves having different opening times due to the effect of packing effect, back pressure, etc. Impact.

The Mach number can be determined by the ratio of the velocity of the fluid to the speed of sound in the fluid. In the Aspen flare system analyzer, Mach number is calculated using Equation 2 below, and the sound velocity in the fluid is obtained using the delta pressure and density difference in the pipe.

<Equation 2>

On the other hand, the gPROMS process builder does not automatically calculate the Mach number, so it must be applied to the new equation. In the present invention, the Mach number of the dynamic model was calculated using Equation 1. In dynamic modeling, Equation 2 can be used like AFSA, but using Equation 1 is very accurate because a large number of variables are used.

< Experimental example > Dynamic modelling  analysis

1. Analysis of high pressure equilibrium separator (HP separator) results

A high pressure equilibrium separator (HP separator) is a device for separating two phases of feed fluid from the seabed into oil and gas in one step. After normal operation at a constant pressure and liquid level for 50 seconds, the gas outlet and the liquid outlet are closed at 50 seconds, which can be confirmed in FIG. 5. Since the feed continuously flows into the separator inlet, the pressure and the liquid level inside the separator continuously increase (separator pressure and separator liquid level in FIG. 5). At this time, since the internal pressure is increased, it can be seen that the inlet mass flow rate is slightly reduced (inlet mass flowrate in FIG. 5). At 63 seconds when the pressure reaches the separator's PAHH warning pressure of 22.72 bar, the forced shut-off valve (SDV) begins to close for 20 seconds and the inlet mass flow rate decreases more rapidly. Even when the forced shut-off valve is closed, the pressure increases and reaches the set pressure of the first pressure relief valve (PSV) (70 seconds), which opens the pressure relief valve and releases the fluid inside the separator to the pressure relief valve. The separator is protected against increasing pressure. From this point on, the increasing slope of the separator pressure decreases, and it remains constant at a pressure below the separator maximum design pressure from 83 seconds after the forced shut-off valve is completely closed. Since the liquid level fraction is also maintained to increase to 0.546, the pressure relief valve releases only one phase of gas, not two phases. However, when modeling using AFSA, the difference in the Mach number is calculated because the composition of the separator inlet feed is input as it is to the pressure safety valve source without taking into account this difference.

2. Pressure Safety valve  Results analysis

The results of the dynamic modeling of the pressure relief valve (PSV) are shown in FIG. 6. Of the five pressure relief valves, only three pressure relief valves have been opened. PSV-A has the lowest set pressure and the set pressure is highest in order of PSV-A, PSV-B, PSV-C, and PSV-D. As a result, PSV-A, B, and C are sequentially opened. Looking at the time, PSV-A opens at 69.95 seconds, PSV-B at 70.73 seconds, and PSV-C at 71.96 seconds. In addition, as the pressure inside the separator decreases, the pressure relief valves close as well, followed by PSV-C, B, and A. Comparing the maximum amount of flare load discharged from the pressure relief valve, the first PSV-A to open is the largest, and the PSV-B to C are the lowest (all orifice sizes of all PSVs are the same and only the set pressure is different) . This is because there is an effect due to the time difference, but the back pressure is applied to the rear end of the pressure safety valve by the pressure safety valve that is opened first, so that the valve is less lifted. By comparing the graphs comparing PSVs between the back pressures (the graph on the right in FIG. 6), it can be confirmed that the back pressures act simultaneously on PSV-B and C at the moment PSV-A opens. Because of this difference, the flare rods discharged from the pressure relief valve are all different, the Mach number in the pipes connected to the rear end is one of the reasons that makes the biggest difference from the results of the Aspen Flare System Analyzer.

3. Mach number  Calculation result and steady state Department of Modeling  comparison analysis

In the dynamic modeling of the present invention, Mach number is calculated by Equation 1, and a Mach number profile in one pipe is shown in FIG. 7. When the pressure relief valve (PSV) opens, it rapidly increases and takes a peak, and the value is selected and compared with the Mach number of the steady-state model AFSA. When the pressure relief valve opens and the flare load is released, the point in time when the Mach number is maximum is not the same as the point in time when the flare load is simply released. Looking at the graph on the right in FIG. 7, the mass flow rate of the pipe increases and the pressure increases one tempo late. According to Equation 1, the Mach number is proportional to the mass flow rate, and inversely proportional to the pressure, so the Mach number has a maximum value before the mass flow rate becomes maximum. Dynamic analysis using only the amount of flare rods released is not accurate, and the optimal design can be made through the analysis of changes in Mach number over time. In general, when determining the Mach number, the Mach number at the inlet and outlet of the pipe is determined separately. However, when the fluid flows in the pipe, the mass flow rate depending on the pipe position is constant, whereas the pressure is lower at the pipe outlet due to the pressure drop, and as a result of Equation 1, the larger Mach number at the outlet Have Therefore, in the present invention, Mach water is mainly used at the pipe discharge portion.

8, 9 and Table 1 below show the Mach number calculated by steady state modeling using Aspen Flare System Analyzer and the Mach number calculated by dynamic modeling using gPROMS. At this time, the display of each pipe (Pipe 1-16) is the same as the pipe of 1-16 in FIG.

Pipe
12 Pipe
13 Pipe
14 Pipe
15 Pipe
16 Pipe
2 Pipe
7 Pipe
3 Pipe
8 Pipe
4 Pipe 9 Pipe
5 Pipe
10 AFSA 0.09 0.19 0.30 0.44 0.28 0.58 0.38 0.57 0.37 0.58 0.38 0.61 0.4 gPROMS 0.00 0.04 0.16 0.43 0.29 0.00 0.00 0.22 0.16 0.64 0.49 0.89 0.89

For most but few pipes, the Mach number obtained through dynamic modeling was calculated low. Except for the pressure relief valves formed on Pipes 1 and 6, only 3 of the 4 pressure relief valves were opened, and the pressure relief valves formed on Pipes 2 and 7 with somewhat higher set pressure did not open, so there was no flow in some pipes. Mach number was calculated as 0. In particular, pipes 4, 5, 9, and 10, which are tail pipes, have a larger Mach number in dynamic modeling, and especially pipes 5 and 10 may exceed the design standard Mach number of 0.7, which may cause safety problems such as vibration during actual operation. . This is due to the sequential occurrence caused by different set pressures having the same orifice size. The largest flare rod is released from the pressure relief valve connected to Pipe 5 with the lowest set pressure, so the largest Mach number in the tail pipe connected to it is calculated. In addition, the higher the set pressure, the slower the Mach number gradually increases toward the pressure relief valves formed on the pipes 4 and 3 that open later. On the other hand, in the case of Aspen Flare System Analyzer (AFSA), unlike gPROMS, only the flare network part is calculated, rather than modeling the process part and flare network part at the same time. Therefore, assuming that all pressure relief valves release the same amount of flare rods, enter the value of the flow rate of the separator inlet divided by the number of pressure relief valves, and proceed in the same way in a typical general project. For these reasons, the biggest difference between steady-state modeling and dynamic modeling appears.

4. Header / pipe size optimization results

The header size was optimized according to the API 521 standard and line sizing criteria using the dynamic modeling results, and the results are shown in FIGS. 10, 11, and Table 2 below.

Pipe
12 Pipe
13 Pipe
14 Pipe
15 Pipe
16 Pipe
2 Pipe
7 Pipe
3 Pipe
8 Pipe
4 Pipe 9 Pipe
5 Pipe
10 AFSA 24 24 24 24 30 10 12 10 12 10 12 10 12 gPROMS - 8 14 24 24 - - - - 10 12 12 14

In general, headers and tail pipes or sub-headers are sized to have a Mach number of 0.7 or less than 0.5. In the present invention, the header is 0.5 or less, and the tail pipe is optimized to have a Mach number of 0.7 or less, and the maximum allowable black pressure (MABP) does not exceed 50% of the set pressure of the pressure relief valve (PSV). Was confirmed. First, the standard Mach number (0.5 or 0.7) is substituted into Equation 1, and the dynamic modeling results show the variables at the time when the Mach number is the maximum (a variable excluding diameter). Flow, pressure, temperature, and compression coefficient ) And the average molecular weight of the gas). As a result, it was possible to find the diameter of the pipe with the minimum size while satisfying the Mach number limit even under the worst conditions.

How much the size of the pipe can be reduced when calculating through dynamic modeling according to the present invention compared to a given value in the project. The results showed that most pipe diameters could be reduced or maintained, but the tail pipes connected to the PSV-A, Pipe 5 and Pipe 10, showed that it was safer to increase the diameter. This is due to the difference in Mach number due to flare rod tilt due to the sequential release of the pressure safety valve as described above.

In general, it is known that flare network design through steady state modeling, which is currently widely used, is oversized due to a large margin. Through the design method of the present invention, it is possible to reduce the cost by reducing the pipe size and to reduce the weight of the offshore plant offshore process. In addition, it is possible to prevent an accident from occurring by changing the diameters of pipes 5 and 10, which are currently designed with a small diameter.

100: flare system
10: high pressure equilibration separator
11: Injection part
12: outlet
20: forced shut-off valve
30: tail pipe
40: pressure safety valve
50: main header
60: knockout drum
70: flare stack

Claims (7)

A design method carried out by a computer in a flare system that includes a pressure relief device, a flare main header, a tail pipe, a knockout drum and a flare stack,
Steps to obtain a variable value when the Mach number is maximum by performing dynamic modeling by setting a time dependent variable in steady state modeling using an emergency scenario of the flare system ; And
Including the step of setting the size of the pipe using the variable value and the Mach number as a design reference;
The emergency scenario is a separator outlet blocked discharge scenario,
The separator outlet blocked discharge scenario,
A high pressure separator including a raw material inlet through which raw materials are injected and a raw material outlet through which raw materials are discharged;
A forced down valve (SDV) formed in the pipe connected to the raw material inlet;
A pressure safety valve (PSV) formed on a tail pipe connected to the high pressure equilibrium separator;
A main header connected to the tail pipe;
Knock Out Drum (Knock Out Drum) for separating the liquid from the incoming component is connected to the main header; And
Flare stack (flare stack) connected to the knockout drum; flare system design method using dynamic modeling, characterized in that the scenario performed in the device comprising a.
delete delete According to claim 1,
The tail pipe is at least two, and each tail pipe is provided with a pressure relief valve. A flare system design method using dynamic modeling.
According to claim 1,
The steady state modeling is a dynamic modeling characterized by setting factors including initial raw material injection conditions, separator size, outlet size, forced shutoff valve size, forced shutoff valve closing speed, and pressure relief valve set pressure. Flare system design method using.
According to claim 1,
The time-dependent variable set in the dynamic modeling,
A method of designing a flare system using dynamic modeling, characterized in that the normal operating time of the initial separator and the outlet of the high pressure equilibrium separator are closed, and the forced shutoff valve is closed after reaching the pressure warning of PAHH.
According to claim 1,
The step of setting the size of the pipe using the variable value and the Mach number as a design criterion is a flare system design method using dynamic modeling calculated through Equation 1 below:
<Equation 1>

(In the above formula 1,
Ma is the Mach number; q _m is the gas mass flow rate (kg / h); p is the pipe outlet pressure (kPa); d is the pipe inner diameter (m); Z is the compressibility; T is the absolute temperature (K); Mw is gas average molecular weight (g / mol).

Images