Supply and delivery system for oil discharge in quenching zone of ethylene steam cracking device

Abstract

The utility model provides a supply and transportation system for oil discharge in a quenching area of a steam cracking ethylene device. The supply and transportation system comprises an underground storage tank supply and transportation system, the underground storage tank supply and transportation system comprises a discharge pipeline, a filter (F) and an underground storage tank. The system is characterized by further comprising a supply and transportation system on the ground, wherein a line in front of the first feed valve (1) of the underground storage tank is connected with a discharge and cooking output line on the ground; a new conveying system on the ground is added in combination with an existing system for shunting, and the defects in the prior art are overcome.

Description

TECHNICAL FIELD

[0001] The utility model relates to the existing oil product process discharge system process, and the petrochemical enterprise petrochemical oil product system has a large number of emptying discharge and cooking treatment and is suitable for application. BACKGROUND

[0002] The existing oil product process discharge system process is that the discharge line setting is generally laid in the underground pipe ditch, and all discharge lines are concentrated into the underground tank in the underground groove. Figure 1 As shown in the figure, it is the general supply and delivery process of the existing steam cracking ethylene device quenching area oil discharge system:

[0003] Figure 1 The discharge pipeline in the pipe ditch, filter F in the middle are arranged on the ground floor in the production area, the underground tank is in the underground groove, and the accumulated water in the underground groove is generally pumped out by a steam-driven jet pump, and the accumulated liquid in the underground tank is generally pumped out by a motor-driven submersible pump M-P.

[0004] Problems:

[0005] 1. High failure rate of submersible pump

[0006] (1) There is a filter F at the inlet of the underground tank, and it is still difficult to avoid smaller coke powder from accumulating in the underground storage. The impeller part of the submersible pump is installed in the lowest circular groove at the bottom of the underground tank, and the coke powder accumulated in the lowest point of the circular groove is the most likely. When the coke powder accumulates to the end, it affects the normal operation of the submersible pump.

[0007] (2) The submersible pump with a unique centrifugal double-balanced impeller can transport media containing solid particles. When the state is good, the vibration noise is low and the operation is stable, but it is still impossible to avoid the influence of particles. When the fault occurs, the current is high, the vibration noise is particularly large, and even if there is a flushing liquid protection, the failure rate is still high.

[0008] (3) The structural characteristics of the submersible pump are affected by the properties of the transported high-viscosity medium liquid, including the physical properties, chemical properties and other properties of the liquid medium. However, the process discharge of the quenching area oil system of the steam cracking ethylene device is complex, including heavy fuel oil, light fuel oil, heavy diesel oil, crude gasoline and even polymers. The temperature c, density d, viscosity u, diameter of solid particles in the medium and content of gas all affect the pump head, effective cavitation allowance and type of pump.

[0009] 2. Submersible pump cannot meet the large discharge capacity of the delivery

[0010] (1) The heat exchanger and filter discharge flow is also relatively large during the daily equipment emptying and maintenance of the device, and the submersible pump operation cannot meet the delivery.

[0011] (2) The oil system discharge amount of the quenching area in the device maintenance shutdown treatment process is large, and the submersible pump cannot meet the large discharge amount, which affects the shutdown progress.

[0012] 3. Loss and influence of underground storage tank gas discharge torch

[0013] (1) The cooking of the oil system discharge process is indispensable, and if the cooking steam is discharged through the discharge system, the steam waste to the flare is caused.

[0014] (2) The oil system discharge is complex, and during the cooking, the polymer is accumulated in the wet flare tank, the wet flare accumulated liquid is transported by the suction pump, and the polymer accumulation filter is blocked, which affects the operation of the pump. Practical new type content

[0015] The utility model provides a kind of steam cracking ethylene device quenching area oil discharge's supply and transport system, its purpose is to solve the problems existing in the supply and transport process of the quenching area oil discharge system of current steam cracking ethylene device, meet the transport of large discharge amount, and avoid the influence of equipment emptying long time cooking discharge on flare system.

[0016] The utility model provides a kind of steam cracking ethylene device quenching area oil discharge's supply and transport system, mainly is reformed and increased an output line, and the increased M-P1 is motor-driven centrifugal pump, and M-P1 and inlet filter are installed on ground floor.

[0017] The technical scheme of the utility model is as follows:

[0018] A kind of steam cracking ethylene device quenching area oil discharge's supply and transport system, including underground storage tank supply and transport system;The underground storage tank supply and transport system includes: discharge pipeline 100, filter F, underground storage tank 200;Multiple discharge pipelines are laid in underground trench, the front end of each discharge pipeline is respectively connected with each discharge medium port of filter discharge, pump discharge, heat exchanger discharge, pipeline discharge or tower / container discharge of oil system, each discharge pipeline is connected to total discharge pipeline after being connected in total, then is connected after being filtered by two parallelly connected filters F, connects the feed valve one 1 of underground storage tank, connects the underground storage tank 200 in underground tank by the feed valve one 1;The discharge pipeline, filter are set in ground floor in production area, and the underground storage tank 200 is set in underground tank;Its characterized in that, it further includes ground surface supply and transport system 300:

[0019] The ground supply system 300 is a ground output line connected to the line before the feed valve 1 of the underground tank; the ground supply system 300 includes two parallel branches, one of which is connected with valve 2, and the other is connected with centrifugal pump M-P1; the end of the ground supply system 300 is connected to the discharge and fractionation line 400 of the underground tank, and the rear end of the discharge and fractionation line is divided into two, one of which is connected to the gasoline fractionation column through the connection valve 3, and the other is connected to the dirty oil tank through the connection valve 4.

[0020] The oil discharge supply system of the quenching zone of the steam cracking ethylene device, wherein the valve 1 is closed, and the valve 2 is opened to enter and return to the gasoline fractionation column through the valve 3 for recovery.

[0021] The oil discharge supply system of the quenching zone of the steam cracking ethylene device, wherein the valve 1 is closed, and the valve 2 is opened to enter and return to the gasoline fractionation column through the valve 3 for recovery.

[0022] The oil discharge supply system of the quenching zone of the steam cracking ethylene device, wherein the valve 1 and the valve 2 are closed, and the centrifugal pump M-P1 is started to transport the medium to the fractionation column or the dirty oil tank.

[0023] The oil discharge supply system of the quenching zone of the steam cracking ethylene device, wherein the motor drives the centrifugal pump M-P1 to pressurize and transport the medium above the pump inlet horizontal line to meet the effective cavitation allowance of the centrifugal pump M-P1; the medium below the centrifugal pump M-P1 inlet horizontal line is discharged into the underground tank by opening the feed valve 1.

[0024] The oil discharge supply system of the quenching zone of the steam cracking ethylene device, wherein the valve 1 and the valve 2 are closed, and the centrifugal pump M-P1 is started to transport the medium to the fractionation column or the dirty oil tank.

[0025] The oil discharge supply system of the quenching zone of the steam cracking ethylene device, wherein the valve 1 and the valve 2 are closed, and the centrifugal pump M-P1 is started to transport the medium to the fractionation column or the dirty oil tank.

[0026] The oil discharge supply system of the quenching zone of the steam cracking ethylene device, wherein the valve 2 is closed, the feed valve 1 is opened to discharge the medium into the underground tank, and the gas is discharged from the underground tank to the wet flare; the liquid is discharged through the discharge and fractionation line, and the rear end of which is divided into two, one of which is connected to the gasoline fractionation column through the connection valve 3, and the other is connected to the dirty oil tank through the connection valve 4.

[0027] The oil discharge supply system of the quenching zone of the steam cracking ethylene device, wherein the underground tank is transported to the fractionation column or the dirty oil tank by the submersible pump M-P.

[0028] The utility model discloses the beneficial effect of:

[0029] The utility model discloses in combination with the prior art increase new ground conveying system and carry out shunting, overcome the drawbacks of prior art.

[0030] The utility model discloses a kind of steam cracking ethylene device quenching area oil discharging's supply and transport system, in quenching area oil system discharge and steam cooking, close underground storage tank feed valve one 1, can be transported from the process of reformation increase.It can be driven by motor to increase pressure transport centrifugal pump M-P1 by the process of reformation increase, it can also rely on the pressure of discharge medium to drive valve two 2 to transport.

[0031] The process of reformation increase can only be driven by motor to increase pressure transport centrifugal pump M-P1 by the process of reformation increase, medium above the level line of pump inlet, above the level line of pump inlet, medium below centrifugal pump M-P1 entrance level line finally opens valve one 1 and is discharged into underground storage tank.

[0032] In the emptying discharge of ethylene device quenching area oil system, fuel oil and quenching oil with higher medium viscosity are all washed by flushing oil replacement, flushing oil itself has higher pressure and can be completely driven by itself, without starting booster pump to transport.Close underground storage tank feed valve one 1, through valve two 2, return gasoline fractionating tower through valve three 3 or transport to dirt oil tank through valve four 4.The viscosity of the medium of emptying discharge of oil system needs to be washed, and the operation of emptying discharge of medium with low viscosity is the same, and all need to be steamed to be qualified, and the process of steaming itself has higher pressure and can be completely driven by itself, and the steaming steam is returned to gasoline fractionating tower through valve two 2 and valve three 3, to avoid the influence of steaming steam into underground storage tank feed from valve five 5 on flare system.

[0033] In the emptying discharge of ethylene device quenching area oil system, fuel oil and quenching oil with higher medium viscosity are all washed by flushing oil replacement, flushing oil itself has higher pressure and can be completely driven by itself, without starting booster pump to transport.Close underground storage tank feed valve one 1, through valve two 2, return gasoline fractionating tower through valve three 3 or transport to dirt oil tank through valve four 4.The viscosity of the medium of emptying discharge of oil system needs to be washed, and the operation of emptying discharge of medium with low viscosity is the same, and all need to be steamed to be qualified, and the process of steaming itself has higher pressure and can be completely driven by itself, and the steaming steam is returned to gasoline fractionating tower through valve two 2 and valve three 3, to avoid the influence of steaming steam into underground storage tank feed from valve five 5 on flare system. BRIEF DESCRIPTION OF DRAWINGS

[0034] Figure 1 It is the supply and transport flow chart of prior steam cracking ethylene device quenching area oil discharge system,

[0035] Figure 2 It is the supply and transport system schematic diagram of the utility model of a kind of steam cracking ethylene device quenching area oil discharge, and the drawing number is explained as follows:

[0036] Filter discharge P1, pump discharge P2, tower / container discharge P3, pipeline discharge P4, heater discharge P5, wet flare J1, seal flush oil J2, gasoline fractionating column J3, slop oil tank J4, nitrogen J5, steam J6, condensate J7; valve 1, valve 2, valve 3, valve 4, valve 5; motor-driven submersible pump M-P, motor-driven centrifugal pump M-P1, trap T, filter F. DETAILED DESCRIPTION

[0037] The specific implementation and the solved technical problems and effects of the utility model are described in detail below in combination with the drawings.

[0038] Referring to Figure 1 , 2 As shown in the utility model discloses a steam cracking ethylene device quenching area oil discharge's supply and delivery system, including underground storage tank supply and delivery system;The underground storage tank supply and delivery system includes: discharge pipeline 100, filter F, underground storage tank 200;The discharge pipeline 100 is in the underground pipe trench and is laid multiple discharge pipelines, and each discharge pipeline front end is connected respectively the filter discharge, pump discharge, heat exchanger discharge, pipeline discharge or tower / container discharge of oil system's each discharge medium port, and each discharge pipeline is connected to the total discharge pipeline after gathering, and is filtered through connecting two parallel filters F, and is connected the feed valve one 1 of underground storage tank, and enters the underground storage tank in the underground tank through the feed valve one 1;The discharge pipeline 100, filter is arranged in the ground under the production area, and the underground storage tank 200 is arranged in the underground tank, and the accumulated water in the underground tank is extracted by the steam-driven jet pump arranged, and the accumulated liquid in the underground storage tank is pumped out by the motor-driven submersible pump M-P;Its characterized in that, still includes ground supply and delivery system 300;

[0039] Although, the submersible pump M-P in the prior art adopts the unique centrifugal double-balance impeller submersible pump and can supply and deliver the medium containing solid particles, and the vibration noise is low and the operation is stable when the state is good.But still cannot avoid the influence of particulate matter, and the current is high and the vibration noise is particularly large when failure, and even if there is flushing liquid protection, the failure rate is still high.

[0040] In addition, the structural characteristics of the submersible pump M-P are influenced by the properties of the high-viscosity medium liquid, including the physical properties, chemical properties and other properties of the liquid medium, but the process discharge of the quenching area oil system of the steam cracking ethylene device is complex, and the discharge pipeline connects any filter, pump, heat exchanger, pipeline and tower / container medium of the oil system, including heavy fuel oil, light fuel oil, heavy diesel oil, crude gasoline and even polymer.The temperature c, density d, viscosity u, solid particle diameter and gas content in the medium, etc.are different, which all affect the pump head, effective cavitation allowance and pump type.

[0041] In addition, the submersible pump cannot meet the delivery of large discharge capacity. The device is daily emptied and overhauled, and the discharge capacity of the heat exchanger and the filter is relatively large, especially the oil system discharge capacity of the quenching area during the shutdown process is larger, and the submersible pump cannot meet the delivery of large discharge capacity, which will affect the shutdown progress.

[0042] In addition, the gas in the underground storage tank is a wet flare, and the cooking of the oil system discharge process is essential. If the underground storage tank supply system of the traditional design is used for cooking steam discharge, the steam waste to the flare will be caused. At the same time, the oil system discharge is complex, and the polymer is accumulated in the wet flare tank during cooking, and the wet flare liquid is transported by the suction pump, and the polymer accumulation filter is blocked, which affects the operation of the pump. In view of the above problems existing in the system, the utility model is improved.

[0043] The utility model discloses a ground supply system 300, see Figure 2 The ground supply system 300 includes two parallel branches, one of which is connected with valve two 2, which is driven by the self-pressure of the discharge medium, and the other branch is connected with centrifugal pump (M-P1), which is driven by the centrifugal pump M-P1 to increase the pressure of the discharge medium and deliver it to the gasoline fractionating tower or the waste oil tank.

[0044] Further explanation: the ground supply system 300 includes two parallel branches, one of which is connected with valve two 2, and the other branch is connected with centrifugal pump M-P1, the end of the ground supply system 300 is connected to the discharge fractionation line 400 of the underground storage tank, the rear end of the discharge fractionation line 400 is divided into two, one is connected to the gasoline fractionating tower through the connecting valve three 3, and the other is connected to the waste oil tank through the connecting valve four 4. That is, the ground supply system 300 and the discharge fractionation line of the underground storage tank are shared at the end, that is, divided into two, one is connected to the gasoline fractionating tower through the connecting valve three 3, and the other is connected to the waste oil tank through the connecting valve four 4, so as to realize the delivery of the discharge medium to the gasoline fractionating tower or the waste oil tank. Such structure is simple and reduces cost.

[0045] When the discharge pipeline connects any filter, pump, heat exchanger, pipeline and tower / container of the oil system, the feed valve one 1 to the underground storage tank can be closed, and two routes are branched from the ground supply system 300 before the underground storage tank feed valve one 1, one of which is driven by the self-pressure of the discharged medium to open valve two 2 to be transported to the fractionating tower or the slop oil tank (i.e. two branches, one connected to the gasoline fractionating tower through connection valve three 3, and the other connected to the slop oil tank through connection valve four 4. The details are not described hereinafter), and the other is pressurized by the motor-driven centrifugal pump M-P1 and transported to the gasoline fractionating tower or the slop oil tank. Thus, the problem of the underground storage tank supply system of the conventional design that the submersible pump M-P cannot meet the large discharge capacity and has a high failure rate is solved.

[0046] When the discharge pipeline connects any filter, pump, heat exchanger, pipeline and tower / container of the oil system, the fractionating tower can be driven by the self-pressure of the cooking discharged medium to open valve two 2 to be transported, so as to avoid the loss of underground storage tank gas flare and the influence.

[0047] When the discharge pipeline connects any filter, pump, heat exchanger, pipeline and tower / container of the oil system, the medium with high viscosity needs to be replaced by flushing oil. The flushing oil itself has high pressure, and can be set to be driven by the self-pressure to return to the gasoline fractionating tower through valve two 2 and valve three 3 or be transported to the slop oil tank through valve four 4.

[0048] In the early stage of the oil system discharge in the process of device maintenance shutdown, the discharge pipeline connects any filter, heat exchanger, pipeline, and the medium itself has high pressure under the operating outlet pressure of the circulating pump or the delivery pump, which can be set to be driven by the self-pressure to return to the gasoline fractionating tower through valve two 2 and valve three 3 or be transported to the slop oil tank through valve four 4.

[0049] One of the ground supply systems can be driven by the self-pressure of the discharged medium to open valve two 2 to be transported to the fractionating tower or the slop oil tank, and the other can be pressurized by the motor-driven centrifugal pump M-P1 and transported to the gasoline fractionating tower or the slop oil tank. When the self-pressure of the discharged medium cannot be driven, the other route is used for pressurized transportation, valve two 2 is closed, the centrifugal pump M-P1 is started to transport, and the gasoline fractionating tower is transported through valve three 3 or the slop oil tank through valve four 4.

[0050] The medium pressurized by the motor-driven centrifugal pump M-P1 can only be the medium above the pump inlet level line to meet the effective cavitation allowance of the centrifugal pump M-P1. The medium below the centrifugal pump M-P1 inlet level line can only be discharged into the underground storage tank. When the effective cavitation allowance of the centrifugal pump M-P1 cannot be met, the centrifugal pump M-P1 will be immediately closed and stopped, the pump outlet valve is opened, and the feed valve one 1 is discharged into the underground storage tank.

[0051] All filters, pumps, heat exchangers, lines and tanks / vessels, etc. are drained and then steamed. When the steam is turned on and the drains are open, the feed valve one 1 to the underground storage tank is closed and the drains are allowed to drive open valve two 2 to send the steaming gases to the fractionation column for recovery.

[0052] After the draining, steaming and purging of the draining lines to the oil system, any filter drains, all pump drains, all heat exchanger drains, all line drains and all tank / vessel drains, etc. are empty and clean, nitrogen is then introduced to displace the air. Valve two 2 is closed and feed valve one 1 is opened to send the nitrogen to the underground storage tank and the air is vented from the underground storage tank to the flare.

Claims

1. A feed system for steam cracking ethylene plant quench zone oil discharges, comprising an underground storage tank feed system; the underground storage tank feed system comprising: The discharge pipeline (100), filter (F), underground storage tank (200); a plurality of discharge pipelines are laid in the underground trench, the front end of each discharge pipeline is connected with each discharge medium port of filter discharge, pump discharge, heat exchanger discharge, pipeline discharge or tower / container discharge of the oil system respectively, each discharge pipeline is connected to the total discharge pipeline, then connected to two parallel connected filters (F) for filtering, and then connected to the feed valve one (1) of the underground storage tank (200); the discharge pipeline and the filter are arranged under the ground in the production area, and the underground storage tank (200) is arranged in the underground tank; characterized in that, the ground supply system (300) is further arranged. The ground supply system (300) is connected to the line before the feed valve one (1) of the underground storage tank; the ground supply system (300) includes two parallel branches, one of which is connected with the valve two (2), and the other of which is connected with the centrifugal pump (M-P1); the end of the ground supply system (300) is connected to the discharge and fractionation line (400) of the underground storage tank, and the rear end of the discharge and fractionation line is divided into two, one of which is connected to the gasoline fractionation tower through the connected valve three (3), and the other of which is connected to the dirty oil tank through the connected valve four (4).

2. A steam cracking ethylene plant quench zone oil discharge feed system as claimed in claim 1 wherein, The feed valve one (1) is closed, the valve two (2) is opened, and the medium is recovered into the gasoline fractionation tower through the valve three (3).

3. A steam cracking ethylene plant quench zone oil discharge feed system as claimed in claim 1 wherein, The feed valve one (1) is closed, the valve two (2) is opened, and the medium is transported to the dirty oil tank through the valve four (4).

4. A steam cracking ethylene plant quench zone oil discharge feed system as claimed in claim 1 wherein, The feed valve one (1) and the valve two (2) are closed, and the centrifugal pump (M-P1) is started to transport the medium to the fractionation tower or the dirty oil tank.

5. A feed system for the discharge of oil from the quench zone of a steam cracking ethylene plant as claimed in claim 4, characterised in that, The motor drives the centrifugal pump (M-P1) to pressurize and transport the medium above the pump inlet horizontal line to meet the effective cavitation allowance of the centrifugal pump (M-P1); the medium below the centrifugal pump (M-P1) inlet horizontal line is discharged into the underground storage tank by opening the feed valve one (1).

6. A feed system for the discharge of oil from the quench zone of an ethylene plant steam cracker as claimed in claim 4 wherein, The feed valve one (1) and the valve two (2) are closed, and the centrifugal pump (M-P1) is started to return to the gasoline fractionation tower through the valve three (3).

7. A system for the removal of oil from the quench zone of an ethylene plant as claimed in claim 4 wherein, The feed valve one (1) and the valve two (2) are closed, and the centrifugal pump (M-P1) is started to return to the gasoline fractionation tower through the valve three (3).

8. A system for the removal of oil from the quench zone of an ethylene plant as claimed in claim 1 wherein, The valve two (2) is closed, the feed valve one (1) is opened, the medium is discharged into the underground storage tank, and the gas is discharged from the underground storage tank to the wet flare; the liquid is discharged through the discharge and fractionation line, the rear end of which is divided into two, one of which is connected to the gasoline fractionation tower through the connected valve three (3), and the other of which is connected to the dirty oil tank through the connected valve four (4).

9. A feed system for the discharge of oil from the quench zone of a steam cracking ethylene plant as claimed in claim 8, characterised in that, The underground storage tank is transported to the fractionation tower or the dirty oil tank by the submersible pump (M-P).

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