Small-displacement flare gas smoke abatement device of large elevated torch

Abstract

The invention discloses a small-displacement flare gas smoke abatement device for a large elevated torch. The small-displacement flare gas smoke abatement device comprises a barrel assembly, a center fire supporting assembly, a silencing cover assembly, an injection smoke abatement assembly and a built-in igniter incandescent light assembly. The cylinder assembly is communicated with the flare gas outlet; the exhaust end of the center fire supporting assembly extends into the barrel assembly and sprays air to the center of the barrel assembly. The silencing cover assembly covers the outer side wall of the lower portion of the barrel assembly, and a mounting interval is reserved. The air inlet end of the injection smoke abatement assembly is contained in the installation interval. The air outlet end of the injection smoke abatement assembly extends into the barrel assembly and extends to the top of the barrel assembly. After the device is used, a flare system is slightly improved, effective combustion of flare gas under the working condition that the flow is lower than 1000Nm < 3 > / h can be realized, the use cost of steam is reduced, the cost can be reduced by more than 78%, and no black smoke is generated during combustion, so that the flare gas under the working condition is fully combusted.

Description

Technical Field

[0001] The present application relates to the technical field of safety and environmental protection, and in particular to a large-scale elevated flare with a small-displacement flare gas smoke elimination device. Background Art

[0002] The elevated flare is a necessary safety and environmental protection system for petrochemical enterprises. It takes into account the three functions of stable production, safety and environmental protection. It is used to treat the waste gas and toxic gas generated by chemical equipment during daily operation, start / stop conditions or flammable gas generated in accident conditions. Especially for treating flare gas volume greater than 5000Nm 3 / h large-scale elevated flare, this type of flare is equipped with a large amount of smoke suppression steam, and is mostly used to treat flare gas greater than 1000Nm 3 / h working condition, the treatment effect is better, such as Figure 7 shown.

[0003] The flare gas processed by large-scale elevated flares in petrochemical industry is mainly hydrocarbons. When a large amount of hydrocarbons burn at the flare head, due to the low oxygen content of the combustion-supporting agent, the gas at the flare head is not completely burned, which can easily produce a large amount of carbon black, forming black smoke outside the flare head and polluting the environment. When the elevated flare is operating normally, in order to ensure the normal and stable combustion of the exhaust gas, and produce exhaust gas that meets the emission standards to achieve qualified emissions, and avoid black smoke or fire rain from the flare head, steam injection or forced air blowing are often used to provide sufficient oxygen for the combustible gas in the flare exhaust gas. This process requires a large amount of steam or electricity, and the operating cost is relatively high.

[0004] In order to reduce the cost of waste gas treatment, the treatment capacity of large-scale elevated flares is designed according to the worst accident conditions (i.e. the maximum fire conditions) of the production unit, that is, the elevated flare is only designed and manufactured to suit a specific condition and cannot adapt to a wider load range. Therefore, when designing the flare, the flare is designed to have a large treatment capacity and a large corresponding smoke suppression steam design volume. The elevated flare can meet the requirements of the production unit for the treatment of severe conditions, but it is not suitable for the small-volume waste gas (flare gas flow rate is less than or equal to 1000Nm 3 / h), the elevated flare cannot guarantee normal combustion and complete decomposition throughout the entire process, resulting in the flare head being prone to "suspicious black smoke" emissions, such as Figure 5 b, which affects the exhaust gas compliance and easily leads to environmental complaints caused by "misunderstanding" by the public.

[0005] For the black smoke caused by small-flow exhaust gas, the existing technology, such as the small-flow acetylene gas burner disclosed in CN202322333068.9, can provide sufficient air for acetylene gas combustion by setting a two-stage smoke elimination structure, which can solve the problem of black smoke from acetylene gas combustion. However, it is necessary to increase equipment investment in the flare head through technical transformation. For large-scale elevated flares, the construction cost of dismantling and reinstalling the flare head alone exceeds 1 million yuan.

[0006] Another existing treatment method is to achieve smoke elimination by adding compressed air, but this method has high initial equipment investment and high later operation and maintenance costs. In addition, it is very easy to cause high oxygen content in the flare head in a short period of time, and there is also a safety risk of flashback implosion.

[0007] The information disclosed in the background technology section is only intended to enhance the understanding of the overall background of the invention and should not be regarded as an admission or any form of suggestion that the information constitutes the prior art already known to a person skilled in the art. Summary of the invention

[0008] The present application provides a large-scale elevated flare with a small-displacement flare gas smoke suppression device, which is used to solve the problems of high investment cost of elevated flare reduction, inability to adapt to a larger load range, high cost of steam smoke suppression under small flow conditions, "suspected black smoke" in small flow flare gas smoke suppression, and the safety risk of flashback implosion in the new compressed air smoke suppression process. With low investment, the technical problem of large-scale flares being able to operate at low cost, safely and in an environmentally friendly manner under the designed operating conditions and the operating conditions of small flow flare gas is achieved.

[0009] The present application provides a large-scale elevated flare with a small displacement flare gas smoke elimination device, comprising: a cylinder assembly, a central fire support assembly, a muffler assembly, an ejector smoke elimination assembly, and a built-in igniter permanent lamp assembly;

[0010] The cylinder assembly is connected to the flare gas outlet; the exhaust end of the central fire-supporting assembly extends into the cylinder assembly and sprays air toward the center of the cylinder assembly;

[0011] The silencer cover assembly is arranged on the outer side wall of the lower part of the cylinder assembly, and an installation interval is reserved; the installation interval accommodates the air inlet end of the ejector smoke elimination assembly; the air outlet end of the ejector smoke elimination assembly is extended into the cylinder assembly and extends to the top of the cylinder assembly;

[0012] The built-in igniter pilot light assembly includes: 3 built-in igniter pilot lights; arranged outside the barrel assembly, the pilot light flame nozzles are arranged at the outer periphery of the top opening of the barrel assembly and are arranged toward the center of the top of the barrel assembly, and the 3 pilot light flame nozzles are evenly distributed at 120° at the outer periphery of the top of the barrel assembly;

[0013] The ejector smoke elimination assembly comprises: a plurality of ejectors; the ejectors are arranged at intervals along the circumference of the cylinder assembly;

[0014] The ejector comprises: a nozzle, a throat, and a diffuser; the nozzle is provided with a swirling interval at the air inlet end of the throat, the throat is evenly arranged on the outer wall of the lower part of the cylinder assembly, and the air outlet end of the throat is detachably connected to the diffuser; the diffuser is evenly arranged inside the cylinder assembly, the air inlet of the diffuser passes through the wall of the cylinder assembly and is connected to the throat, and the air outlet end of the diffuser is arranged at the top inside the cylinder assembly;

[0015] The air inlet end of the nozzle is connected to the medium-pressure steam gas source and the low-pressure nitrogen gas source pipeline;

[0016] When the flare gas flow rate into the cylinder assembly is less than or equal to 1000Nm 3 / h, the air inlet end of the nozzle is connected to the low-pressure nitrogen gas source pipeline; the flow rate of the torch gas in the cylinder assembly and the flow rate of the nitrogen are in a ratio of 2 to 3:1;

[0017] The pressure of the medium-pressure steam gas source is 1.6MpaG, and the pressure of the low-pressure nitrogen gas source is 0.4~0.6MPaG.

[0018] Preferably, the air inlet end of the central fire-supporting assembly is connected to the medium-pressure steam gas source and the low-pressure nitrogen gas source pipeline.

[0019] Preferably, the diffuser comprises: a wide-mouth section and a conical transition section; the throat is connected to one end of the conical transition section of the diffuser; the wide-mouth section and the other end of the conical transition section are connected;

[0020] The diameter of the throat is smaller than the diameter of the wide mouth section;

[0021] The diffusion tube is arranged in the cylinder assembly;

[0022] The air entrainment intervals of the nozzle and the throat are accommodated and arranged in the installation interval.

[0023] Preferably, it comprises: a second low-pressure nitrogen branch pipe and an ejector pipe; the air inlet end of the nozzle is connected to the medium-pressure steam source through the ejector pipe; one end of the second low-pressure nitrogen branch pipe is connected to the low-pressure nitrogen source, and the other end is connected to the ejector pipe;

[0024] A second check valve is provided on the second low-pressure nitrogen branch pipe;

[0025] A smoke suppression steam regulating valve is provided on the induced air pipe.

[0026] Preferably, it comprises: a second control valve; a second check valve is arranged before the second control valve, and the second control valve is arranged on the second low-pressure nitrogen branch pipe;

[0027] The second control valve is a remote regulating valve.

[0028] Preferably, it comprises: a first low-pressure nitrogen branch pipe and a central air pipe; the air inlet end of the central fire-supporting assembly is connected to the medium-pressure steam source through the central air pipe; one end of the first low-pressure nitrogen branch pipe is connected to the low-pressure nitrogen source, and the other end is connected to the central air pipe;

[0029] A fire-supporting steam regulating valve is installed on the central gas pipe.

[0030] Preferably, it comprises: a first control valve and a first check valve; the first check valve and the first control valve are arranged on the first low-pressure nitrogen branch pipe, and the first check valve is arranged before the first control valve;

[0031] The first control valve is a remote regulating valve.

[0032] Preferably, it includes: a spare ignition assembly; the spare ignition assembly and the built-in igniter permanent lamp assembly are arranged in parallel close to the outside of the barrel assembly; the end of the spare ignition assembly is opposite to the flame nozzle of the built-in igniter permanent lamp assembly and is arranged on the open end of the barrel assembly.

[0033] Preferably, when the discharge flow rate of the flare gas is less than or equal to 1000 Nm 3 / h, perform the following operations according to the following flow rate:

[0034] 1) When the torch gas flow rate in the cylinder assembly is 300Nm 3 / h, the flow rate of smoke-eliminating nitrogen entering the nozzle is 100Nm 3 / h while shutting down the medium-pressure steam source;

[0035] 2) When the torch gas flow rate in the cylinder assembly is 400Nm 3 / h, the flow rate of smoke-eliminating nitrogen entering the nozzle is 120Nm 3 / h while shutting down the medium-pressure steam source;

[0036] 3) When the flare gas flow rate in the cylinder assembly 11 is 500Nm 3 / h, the flow rate of smoke-eliminating nitrogen entering the nozzle is 188Nm 3 / h while shutting down the medium-pressure steam source;

[0037] 4) When the flare gas flow rate in the cylinder assembly 11 is 1000Nm 3 / h, the flow rate of smoke-eliminating nitrogen entering the nozzle is 300Nm 3 / h and shut down the medium-pressure steam source at the same time.

[0038] Preferably, when the discharge flow rate of the flare gas is greater than 1000 Nm 3 / h, perform the following operations according to the airflow conditions:

[0039] 1) When the medium-pressure steam source is supplied normally, the opening degree of the fire-supporting steam regulating valve provided on the pipeline connecting the central fire-supporting assembly and the medium-pressure steam source is 30%, and the smoke-eliminating steam regulating valve connected to the nozzle is opened according to the change of smoke color, and the first control valve is closed;

[0040] 2) When the medium-pressure steam source is cut off and the low-pressure nitrogen source is normally supplied, the first control valve is opened to 50%;

[0041] 3) When the medium-pressure steam gas source is cut off and the low-pressure nitrogen gas source supply is reduced, adjust the opening of the first control valve until the device is safely shut down.

[0042] The beneficial effects of this application include:

[0043] 1) The large-scale elevated flare with small-displacement flare gas smoke elimination device provided in this application requires little equipment improvement after use, and can achieve a flow rate of less than 1000Nm 3 / h working condition flare gas is effectively burned, reducing steam usage costs by more than 78%, and no black smoke is produced during combustion, indicating that the flare gas under such working conditions has been fully burned.

[0044] 2) The small-displacement flare gas smoke suppression device for a large elevated flare provided in this application does not require replacement or substantial improvement of existing medium-pressure steam equipment, has small equipment changes, good combustion stability, and increases the applicable flare gas flow operating range of large elevated flares.

[0045] 3) The large-scale elevated flare and small-displacement flare gas smoke elimination device provided in the present application can provide the required lifting airflow when the medium-pressure steam is cut off by setting a low-pressure nitrogen branch to the central flame supporting component, thereby ensuring the normal combustion of the flare gas.

[0046] 4) The large-scale elevated flare with small-displacement flare gas smoke elimination device provided by this application can effectively eliminate the "suspicious black smoke" phenomenon of a large amount of steam condensation water mist that occurs when the small-flow flare gas steam smoke elimination is carried out by utilizing the colorless and transparent nature of nitrogen, thereby avoiding environmental protection complaints caused by "misunderstandings" by the public. The flare of this structure operates 97% of the time throughout the year with small-flow flare gas (800-1300Nm 3 / h) working condition, using low-cost nitrogen can achieve ultra-low-cost operation of the flare throughout the year.

[0047] 5) The large-scale elevated flare small-displacement flare gas smoke suppression device provided in the present application uses inert nitrogen to replace the fire-supporting steam. Compared with the use of compressed air to replace the fire-supporting steam, nitrogen has an asphyxiating inertness and can be mistakenly inhaled into the flare pipeline network, which can effectively eliminate the safety risk of flashback implosion. However, compressed air can be mistakenly inhaled into the flare pipeline network, which can easily form a mixed explosive gas in the flare fuel gas pipeline network, causing flashback implosion. BRIEF DESCRIPTION OF THE DRAWINGS

[0048] Figure 1 A schematic diagram of the connection state of the ejector gas pipe and the second low-pressure nitrogen gas branch pipe in Example 1 provided in the present application;

[0049] Figure 2 A schematic diagram of the connection state of the central air pipe and the first low-pressure nitrogen branch pipe in Example 1 provided in the present application;

[0050] Figure 3This is a schematic cross-sectional structural diagram of the flare tip in Example 1 provided in this application;

[0051] Figure 4 A schematic cross-sectional structural diagram of the ejector in Example 1 provided in the present application;

[0052] Figure 5 The combustion photos of the flare gas after treatment in Comparative Example 1 provided in this application; a) The flare gas flow rate is less than 1000Nm 3 / h, the flare gas breaks through the water seal; b) the flow rate is less than 1000Nm 3 / h, the flare gas failed to break through the water seal;

[0053] Figure 6 The combustion photos of the flare gas after treatment in Example 1 provided in this application; a) The flare gas flow rate is less than 1000Nm 3 / h, the flare gas breaks through the water seal; b) the flow rate is less than 1000Nm 3 / h, the flare gas failed to break through the water seal;

[0054] Figure 7 In the comparative example 1 provided in this application, the flare gas flow rate is higher than 1000Nm 3 / h, photo of flare gas combustion after treatment.

[0055] Legend:

[0056] Nozzle 1, throat 2, diffuser 3, cylinder assembly 11, central fire supporting assembly 12, silencer hood assembly 13, smoke suppression assembly 14, built-in igniter long-burning lamp assembly 15, spare ignition assembly 16, first control valve 21, second control valve 22, second check valve 23, first check valve 24, smoke suppression steam regulating valve 25, fire supporting steam regulating valve 26. DETAILED DESCRIPTION

[0057] The present invention is further described in detail below in conjunction with the accompanying drawings and embodiments, but the present invention is not limited in any way. Any changes or improvements made based on the teachings of the present invention fall within the protection scope of the present invention.

[0058] Example

[0059] Unless otherwise specified, the materials and instruments used in the following examples were obtained from commercial channels; the detection methods used were all existing methods unless otherwise specified.

[0060] Example 1

[0061] 1. Based on the analysis and research of combustion theory, nitrogen is used as the power source for flare smoke elimination. Nitrogen provides power, and multiple ejectors spaced apart from the lower periphery of the flare head are set to spray and draw in combustion-supporting air, thereby achieving full smokeless combustion of small-flow flare gas and eliminating black smoke generated by incomplete combustion; reducing equipment modification and achieving full combustion of small-flow exhaust gas.

[0062] 1)Torch combustion head:

[0063] The structure of the flare head used is as follows: Figure 3 As shown, it includes: a barrel assembly 11, a central fire support assembly 12, a silencer cover assembly 13, an ejector smoke elimination assembly 14, a built-in igniter permanent lamp assembly 15, and a spare ignition assembly 16; the barrel assembly 11 is connected to the flare gas outlet; the lower side wall of the barrel assembly 11 is provided with a central fire support assembly 12 extending into the barrel assembly 11; the silencer cover assembly 13 is covered on the lower outer wall of the barrel assembly 11; the ejector smoke elimination assembly 14 is accommodated in the spacing area between the silencer cover assembly 13 and the barrel assembly 11 domain; one end of the induced smoke suppression component 14 extends into the cylinder component 11 and extends to the top; the built-in igniter long-burning lamp component 15 is installed on the outside of the silencer cover component 13 and extends to the exhaust end of the top of the cylinder component 11, and the flamethrower of the built-in igniter long-burning lamp component 15 is arranged opposite to the exhaust end of the top of the cylinder component 11 to ignite and burn the mixed gas discharged from the induced smoke suppression component 14; the spare ignition component 16 and the built-in igniter long-burning lamp component 15 are arranged side by side close to the outside of the cylinder component 11.

[0064] The flare gas is ejected from the ejection space of the diffusion tube 3 of the ejection smoke suppression assembly 14 arranged in the cylinder assembly, and extends into the part of the cylinder assembly 11; and fully contacts and burns with the oxygen sucked into the mixed gas ejected from the diffusion tube 3.

[0065] join Figures 1-2 The medium-pressure steam source is connected to the air inlet pipelines of the central fire-supporting assembly 12 and the ejector smoke-eliminating assembly 14 respectively; the medium-pressure steam source is connected to the central fire-supporting assembly 12 through the central air pipe; the first low-pressure nitrogen branch pipe connects the low-pressure nitrogen source and the side wall of the central air pipe; the first control valve 21 is arranged on the first low-pressure nitrogen branch pipe. The pressure value of the low-pressure nitrogen used is 0.4-0.6MPaG. The fire-supporting steam regulating valve 26 is arranged on the central air pipe.

[0066] The medium-pressure steam source is connected to the central flame supporting assembly 12 and can be used as a backup gas source; when the medium-pressure steam supply is insufficient, the low-pressure nitrogen source ensures the airflow required for supporting and ensures that the flame at the flare mouth burns vertically, preventing the flare gas from collapsing and burning at the flare head and damaging the flare head.

[0067] The medium-pressure steam source is connected to the ejector smoke elimination component 14 through the ejector gas pipe; the second low-pressure nitrogen branch pipe connects the low-pressure nitrogen source and the side wall of the ejector gas pipe; the second low-pressure nitrogen branch pipe is provided with a second control valve 22. The pressure value of the medium-pressure steam source is 1.6MpaG.

[0068] Specifically, the first control valve 21 and the second control valve 22 used are remote regulating valves. By setting the remote regulating valve, the amount of smoke-eliminating nitrogen added can be controlled to ensure that the smoke-eliminating nitrogen supply matches the amount of flare gas discharged by the flare, ensuring effective smoke elimination, ensuring that the flame-supporting nitrogen can effectively separate the flame from the flare head, prevent the flare head from collapsing, and extend the life of the flare head. After the steam of the entire plant is interrupted, the production equipment will discharge a large amount of combustible gas to the elevated flare system; at this time, there is no steam, and the use of flame-supporting nitrogen can effectively protect the flare head.

[0069] Specifically, the first low-pressure nitrogen branch pipe and the second low-pressure nitrogen branch pipe are respectively provided with a first check valve 24 and a second check valve 23. The second check valve 23 and the first check valve 24 can prevent steam from entering the nitrogen system due to mistakes of process operators.

[0070] The instantaneous flow rate of the working fluid passing through the torch is ≤1000Nm 3 / h working condition, open the second control valve 22, and introduce nitrogen to perform smoke elimination.

[0071] Specifically, when the flare gas flow rate in the barrel assembly 11 is 300 Nm 3 / h, the flow rate of smoke elimination nitrogen is 100Nm 3 / h and close the steam pipeline at the same time.

[0072] When the flare gas flow rate in the cylinder assembly 11 is 400Nm 3 / h, the flow rate of smoke elimination nitrogen is 120Nm 3 / h and close the steam pipeline at the same time.

[0073] When the flare gas flow rate in the cylinder assembly 11 is 500Nm 3 / h, the flow rate of smoke elimination nitrogen is 188Nm 3 / h and close the steam pipeline at the same time.

[0074] When the flare gas flow rate in the cylinder assembly 11 is 1000Nm 3 / h, the flow rate of smoke elimination nitrogen is 300Nm 3 / h and close the steam pipeline at the same time. By controlling the amount of smoke-eliminating nitrogen introduced according to this parameter, effective and full combustion of the flare gas can be achieved to avoid the generation of black smoke.

[0075] The flow rate relationship between the flare gas and the smoke-eliminating nitrogen in the cylinder assembly 11 is 2-3:1, and accordingly, the smoke-eliminating nitrogen of the corresponding flow rate is obtained through the second control valve 22 .

[0076] When the flare gas flow rate increases, it is necessary to open the fire-supporting steam regulating valve 26 of the central gas pipe and the smoke suppression steam regulating valve 25 on the induced gas pipe, and then close the first control valve 21 and the second control valve 22 to prevent steam from entering the low-pressure nitrogen.

[0077] The ejector smoke suppression assembly 14 includes: a plurality of ejectors and a mounting seat; the ejection sections of the ejectors extend into the barrel assembly 11 and are spaced apart from each other; the flare gas diffuses and moves toward the flare mouth through the barrel assembly 11, and meets the air and nitrogen mixed gas ejected from the ejectors at the flare mouth and ignites and burns under the ignition of the built-in igniter long-burning lamp assembly 15.

[0078] join Figure 4 The ejection section diffusion pipes of the ejector are evenly spaced and installed in the barrel assembly 11. The air inlet end (throat) of the ejector obliquely extends out of the side wall of the barrel assembly 11 and is installed between the muffler cover assembly 13 and the barrel assembly 11.

[0079] Ejector Figure 4 As shown, it includes: a nozzle 1, a throat 2 and a diffuser 3. The mounting end of the nozzle 1 is mounted on the smoke ejector ring tube outside the barrel assembly 11 through a flange, and the other end of the nozzle 1 is extended toward the mounting end of the throat 2 with a contracted opening, and is spaced from the throat 2, and the spacing area is set outside the barrel assembly 11; the other end of the throat 2 is obliquely arranged on the side wall of the barrel assembly 11 and is detachably connected to the diffuser 3 accommodated in the barrel assembly 11; after the throat 2 and the diffuser 3 are assembled, the end of the throat 2 is a narrow mouth end, and the diffuser 3 is a wide mouth section; a cone transition section is set between the narrow mouth section and the wide mouth section. Thereby, the entrainment of combustion-supporting air is achieved. The inner diameter of the throat 2 is consistent with the narrow mouth section; the wide mouth section and the cone transition section are set on the diffuser 3. The mounting end of the nozzle 1 is connected to the ejector air pipe. A smoke suppression steam regulating valve 25 is set on the ejector air pipe.

[0080] When in use, low-pressure nitrogen or medium-pressure steam is used as the working fluid and passes through the nozzle 1. The flow rate is increased and then ejected. Part of the static pressure energy of the gas is converted into kinetic energy, forming a vacuum in the area of ​​the throat 2 facing the nozzle 1. Under the action of jet turbulence diffusion, the surrounding air in the area between the throat 2 and the nozzle 1 is sucked into the throat 2. After the two fluids of different pressures exchange energy in the throat 2, the flow rate of the working fluid decreases, and the flow rate of the air sucked into the throat 2 in the same period of time is relatively increased. After the working fluid and the air are mixed in the throat 2 to form a fluid, when passing through the diffuser 3, since the inner diameter of the diffuser 3 is larger than that of the throat 2, the fluid flow rate gradually decreases in the transition section of the cone, and the kinetic energy is converted into pressure energy, and the mixed fluid is ejected. Through this process, the air content in the working fluid increases.

[0081] The flow rate is reduced, and the working fluid with increased oxygen content forms a mixed gas fluid, which is discharged from one end of the diffusion tube 3 and contacts the flare gas. After being ignited by the built-in igniter long-light lamp assembly 15, the flare gas in the cylinder assembly 11 is ignited.

[0082] 2) Theoretical analysis of using nitrogen as the ejector gas source:

[0083] The relationship between the ejector's structural parameters, flow rate, and pressure reflects the impact of energy conversion in the ejector on its performance. Dimensionless parameters are generally used to define the ejector's operating characteristics.

[0084] Flow ratio calculation formula: Where: Q1 is the volume flow rate of the working fluid, Q2 is the volume flow rate of the sucked fluid.

[0085] Pressure ratio calculation formula: Where: H1 is the working fluid head, Hs is the head of the sucked fluid, Hd It is the ejector outlet head.

[0086] Area ratio calculation formula: Where: F1 is the nozzle outlet area, F2 is the cross-sectional area of ​​the throat.

[0087] The calculation formula of suction area ratio is: Where: Fs1 is the flow area of ​​the sucked fluid at the nozzle outlet section, Fs2 It is the flow area of ​​the sucked fluid at the throat inlet section.

[0088] Ejector efficiency calculation formula:

[0089] The smoke elimination method provided by the present application adopts the above-mentioned device structure, and the ejector structure used remains unchanged, so the ejector area ratio and the suction area ratio remain unchanged, and the sucked fluid is air. Hs The head remains unchanged. Under the same smoke elimination conditions, according to formula ⑤, in order to ensure the efficiency of the ejector, it is only necessary to ensure that the nitrogen used for smoke elimination can provide a working fluid volume flow that matches the steam it replaces. Q1 and H1 It can be the head of the working fluid.

[0090] From the above analysis, it can be seen that by using the device and the operating method provided by the present application, nitrogen can be used to replace steam to achieve the effect of reducing the pressure below 1000Nm 3 / h working condition, the flare gas with a flow rate of 1000 tons is efficiently burned, thus avoiding the black smoke problem generated under such working conditions, and the combustion efficiency is very high, without smoke combustion. For specific use effects, please visit Figure 6 .

[0091] Figure 6 a is the combustion effect of the flare gas after breaking through the water seal. The use of this device does not affect the normal combustion effect of the large flow flare gas, and achieves effective and full combustion of the flare gas. Figure 6 b shows the combustion effect without breaking the water seal, and no "suspected black smoke" combustion is observed, indicating that the method provided by this application can achieve the combustion of less than 1000Nm 3 / h working condition to ensure complete combustion of flare gas.

[0092] Comparative Example 1

[0093] Use existing installed steam supply system to handle less than 1000Nm 3 / h working condition of flare gas, the treatment effect is as follows Figure 5 shown. Figure 5 a is the combustion effect of the flare gas after breaking through the water seal, achieving effective and full combustion of the flare gas. Figure 5 b shows the combustion effect without breaking the water seal. Obvious excess tail steam appears during combustion, indicating that effective combustion cannot be achieved for the flare gas flow condition that cannot break the water seal.

[0094] By comparison Figures 5-6 It can be seen that when the above structure and method are not adopted, the steam design volume is too large, and the flare gas flow rate is less than 1000Nm 3 / h working condition, the flare gas cannot be effectively burned throughout the process, which will cause serious "suspected black smoke" problem ( Figure 5 b); By adopting the device and method provided by the present application, under the same working conditions, combustion is free of black smoke and the combustion cost is reduced.

[0095] Flare gas flow rate is less than 1000Nm 3 The actual test results of different working conditions are as follows:

[0096] 1. The device in Example 1 and the airflow control method in Comparative Example 1 are used to process 1000 Nm 3 / hThe smoke elimination working flow rate under flare gas working conditions is compared with the test results obtained by using steam for smoke elimination treatment as shown in the following table:

[0097] Table 1

[0098]

[0099] 2. The device in Example 1 and the airflow control method in Comparative Example 1 are used to process 800 Nm 3 / hThe smoke elimination working flow rate under flare gas working conditions is compared with the test results obtained by using steam for smoke elimination treatment as shown in the following table:

[0100] Table 2

[0101]

[0102] 3. The device in Example 1 and the airflow control method in Comparative Example 1 are used to process 500 Nm 3 / hThe smoke elimination working flow rate under flare gas working conditions is compared with the test results obtained by using steam for smoke elimination treatment as shown in the following table:

[0103] Table 3

[0104]

[0105] From Tables 1 to 3 above, it can be seen that the device provided by the present application can achieve the following 3 / h, the nitrogen consumption is significantly reduced, and the corresponding cost is reduced by more than 78%. The effect of reducing costs and increasing efficiency is remarkable.

[0106] Example 2 Actual test of working medium of elevated flare center support assembly

[0107] Using the device and method disclosed in Example 1, for flare gas flow rate higher than 1000Nm 3 / h working condition, it is necessary to ensure that the combustion flame is a thin waist regular triangle rigid flame, which requires the required fire-supporting steam or fire-supporting nitrogen working flow. The actual test results of using steam and nitrogen as the fire-supporting airflow are as shown in the following table. The fire-supporting airflow is the airflow passing through the central fire-supporting component 12:

[0108] Table 4

[0109]

[0110]

[0111] From Table 4 above, we can see that the consumption of supporting fire steam and supporting fire nitrogen is compared: when a large amount of discharge is used, the normal consumption of supporting fire steam is 2.5t / h. After testing, after switching to nitrogen, the normal consumption of supporting fire nitrogen is 232Nm 3 / h, effectively reducing the consumption of supporting working gas.

[0112] According to the structure of conventional elevated flare head assemblies, using inert nitrogen to replace the fire-supporting steam is compared with using compressed air to replace the fire-supporting steam. Because nitrogen has asphyxiating inertness, it can enter the barrel assembly 12 from the central fire-supporting assembly 12 and be accidentally sucked into the flare pipe network, causing the flare pipe network to become an inert gas state, which can effectively eliminate the safety risk of flashback implosion; while compressed air enters the barrel assembly 12 from the central fire-supporting assembly 12 and is accidentally sucked into the flare pipe network. The compressed air and the fuel gas pipe in the flare pipe network can easily form a mixed explosive gas in the flare pipe network, causing flashback implosion.

[0113] Example 3 Actual measurement of gas velocity of various flare gases

[0114] The following working conditions all adopt the device and operation method disclosed in Example 1:

[0115] 1. Torch large discharge condition (>1000Nm 3 / h):

[0116] In case 1 (normal steam supply), to ensure the safety of the elevated flare head, the second non-return valve 23 of the fire-supporting steam is directly opened to 30% to ensure that the flare flame is an elongated triangle to prevent the flare head from collapsing. The addition of induced steam is adjusted according to the flame situation to prevent black smoke.

[0117] In case 2 (steam interruption and sufficient nitrogen), directly open the first control valve 21 to 50% to ensure that the flare flame is an elongated triangle to prevent the flare head from collapsing;

[0118] In case three (steam interruption, nitrogen shortage), under the condition of ensuring safe shutdown of the device and nitrogen use, adjust and control the opening of the first control valve 21 to prevent the flare head from collapsing and burning.

[0119] From the above, it can be seen that the device provided in this application can be used to effectively support the fire of various types of flare gas flow rates.

[0120] Although the present invention has been described in detail with reference to the aforementioned embodiments, it is still possible for those skilled in the art to modify the technical solutions described in the aforementioned embodiments, or to make equivalent substitutions for some of the technical features therein. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A large-scale elevated flare with small-displacement flare gas smoke elimination device, characterized in that: include: A cylinder assembly (11), a central fire support assembly (12), a muffler assembly (13), an ejector smoke elimination assembly (14), and a built-in igniter permanent lamp assembly (15); The barrel assembly (11) is connected to the flare gas outlet; the exhaust end of the central flame supporting assembly (12) extends into the barrel assembly (11) and sprays gas toward the center of the barrel assembly (11); The silencer cover assembly (13) is arranged on the lower outer side wall of the cylinder assembly (11) and is provided with an installation space; the installation space accommodates the air inlet end of the ejector smoke elimination assembly (14); the air outlet end of the ejector smoke elimination assembly (14) is extended into the cylinder assembly (11) and extends to the top of the cylinder assembly (11); The built-in igniter ever-burning lamp assembly (15) comprises: three built-in igniter ever-burning lamps; arranged outside the barrel assembly (11); the ever-burning lamp flame nozzles are arranged at the outer periphery of the top opening of the barrel assembly (11) and are arranged toward the center of the top of the barrel assembly (11); the three ever-burning lamp flame nozzles are evenly distributed at 120 degrees at the outer periphery of the top of the barrel assembly (11); The ejector smoke elimination component (14) comprises: a plurality of ejectors; the ejectors are arranged at intervals along the circumference of the cylinder component (11); The ejector comprises: a nozzle (1), a throat (2), and a diffuser (3); the nozzle (1) has a closed end facing the throat (2) with an air entrainment interval reserved; the throat (2) is evenly spaced and arranged on the lower outer wall of a barrel assembly (11); the air outlet of the throat (2) is detachably connected to the diffuser (3); the diffuser (3) is evenly spaced and arranged inside the barrel assembly (11); the air inlet of the diffuser (3) passes through the wall of the barrel assembly (11) and is connected to the throat (2); the air outlet of the diffuser (3) is arranged at the top inside the barrel assembly (11); The air inlet end of the nozzle (1) is connected to medium-pressure steam gas source and low-pressure nitrogen gas source pipelines; When the flare gas flow rate introduced into the cylinder assembly (11) is less than or equal to 1000 Nm 3 / h, the air inlet end of the nozzle (1) is connected to the low-pressure nitrogen gas source pipeline; the flow rate of the torch gas in the barrel assembly (11) and the flow rate of the nitrogen are in a relationship of 2 to 3:1; The pressure of the medium-pressure steam gas source is 1.6MpaG, and the pressure of the low-pressure nitrogen gas source is 0.4~0.6MPaG.

2. The large-scale elevated flare with small-displacement flare gas smoke elimination device according to claim 1 is characterized in that: The air inlet end of the central fire-supporting assembly (12) is connected to medium-pressure steam gas source and low-pressure nitrogen gas source pipelines.

3. The large-scale elevated flare with small-displacement flare gas smoke elimination device according to claim 1 is characterized in that: The diffuser (3) comprises: a wide mouth section and a conical transition section; the throat (2) is connected to one end of the conical transition section of the diffuser (3); and the other ends of the wide mouth section and the conical transition section are connected; The diameter of the throat pipe (2) is smaller than the diameter of the wide mouth section; The diffusion tube (3) is arranged in the cylinder assembly (11); The air entrainment intervals of the nozzle (1) and the throat pipe (2) are accommodated and arranged in the installation interval.

4. The large-scale elevated flare with small-displacement flare gas smoke elimination device according to claim 1 is characterized in that: include: a second low-pressure nitrogen branch pipe and an ejector pipe; an air inlet end of the nozzle (1) is connected to a medium-pressure steam source via the ejector pipe; one end of the second low-pressure nitrogen branch pipe is connected to the low-pressure nitrogen source, and the other end is connected to the ejector pipe; A second check valve (23) is provided on the second low-pressure nitrogen branch pipe; A smoke elimination steam regulating valve (25) is arranged on the ejection air pipe.

5. The large-scale elevated flare with small-displacement flare gas smoke elimination device according to claim 4 is characterized in that: include: a second control valve (22); a second check valve (23) is arranged before the second control valve (22), and the second control valve (22) is arranged on the second low-pressure nitrogen branch pipe; The second control valve (22) is a remote regulating valve.

6. The large-scale elevated flare with small-displacement flare gas smoke elimination device according to claim 2 is characterized in that: include: A first low-pressure nitrogen branch pipe and a central air pipe; an air inlet end of the central fire-supporting assembly (12) is connected to a medium-pressure steam source through the central air pipe; one end of the first low-pressure nitrogen branch pipe is connected to the low-pressure nitrogen source, and the other end is connected to the central air pipe; A fire-supporting steam regulating valve (26) is arranged on the central gas pipe.

7. The large-scale elevated flare with small-displacement flare gas smoke elimination device according to claim 6 is characterized in that: include: A first control valve (21) and a first check valve (24); the first check valve (24) and the first control valve (21) are arranged on the first low-pressure nitrogen branch pipe, and the first check valve (24) is arranged before the first control valve (21); The first control valve (21) is a remote regulating valve.

8. The large-scale elevated flare with small-displacement flare gas smoke elimination device according to claim 1 is characterized in that: include: A spare ignition assembly (16); the spare ignition assembly (16) and the built-in igniter permanent lamp assembly (15) are arranged in parallel close to the outer side of the barrel assembly (11); the end of the spare ignition assembly (16) is opposite to the flame nozzle of the built-in igniter permanent lamp assembly (15) and is arranged on the open end of the barrel assembly (11).

9. The large-scale elevated flare with small-displacement flare gas smoke elimination device according to claim 1 is characterized in that: When the flare gas discharge flow rate is less than or equal to 1000Nm 3 / h, perform the following operations according to the following flow rate: 1) When the flare gas flow rate in the cylinder assembly (11) is 300 Nm 3 / h, the flow rate of smoke-eliminating nitrogen gas entering the nozzle (1) is 100Nm 3 / h while shutting down the medium-pressure steam source; 2) When the flare gas flow rate in the cylinder assembly (11) is 400 Nm 3 / h, the flow rate of smoke-eliminating nitrogen entering the nozzle (1) is 120Nm 3 / h while shutting down the medium-pressure steam source; 3) When the flare gas flow rate in the cylinder assembly 11 is 500Nm 3 / h, the flow rate of smoke-eliminating nitrogen gas entering the nozzle (1) is 188Nm 3 / h while shutting down the medium-pressure steam source; 4) When the flare gas flow rate in the cylinder assembly 11 is 1000Nm 3 / h, the flow rate of smoke-eliminating nitrogen gas entering the nozzle (1) is 300Nm 3 / h and shut down the medium-pressure steam source at the same time.

10. The large-scale elevated flare with small-displacement flare gas smoke elimination device according to claim 2, characterized in that: When the flare gas discharge flow rate> 1000Nm 3 / h, perform the following operations according to the airflow conditions: 1) When the medium-pressure steam source is supplied normally, the opening degree of the fire-supporting steam regulating valve (26) provided on the pipeline connecting the central fire-supporting assembly (12) and the medium-pressure steam source is 30%, and the smoke-eliminating steam regulating valve (25) connected to the nozzle (1) is opened according to the change of smoke color, and the first control valve (21) is closed; 2) When the medium-pressure steam source is cut off and the low-pressure nitrogen source is normally supplied, the first control valve (21) is opened to 50%; 3) When the medium-pressure steam gas source is cut off and the gas supply of the low-pressure nitrogen gas source is reduced, the opening of the first control valve (21) is adjusted and controlled until the device is safely shut down.

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