CN209484275U - A kind of gaseous ethane pipeline shutdown restarts system - Google Patents

Abstract

The utility model discloses a kind of gaseous ethane pipeline shutdowns to restart system, including main line starting point valve group and temperature, pressure flow quantity detecting system, and trunk end valve group and temperature, pressure flow quantity detecting system and trunk end bypass valve group, heat tracing pipe-line system.The utility model can meet: 1) ethane pipeline improves operating pressure, allows pipeline when stopping transportation to form liquid ethane, reduces caliber；2) during restarting, when upstream enters gaseous ethane, ethane is discharged by bypass, to control ethane gas discharge capacity, realizes and newly enters ethane and accumulate ethane heat exchange, and by reducing pipeline pressure in a small amount, slowly liquid ethane is accumulated in vaporization；3) it during restarting, by bypass stainless steel valve group and tracing system, avoids ethane after throttling from generating low temperature effect to pipe-line system, is also improving its temperature to a certain degree, ethane after throttling is avoided to generate low temperature effect to down-stream system；4) during restarting, the ethane of start-up course being continuously discharged can enter down-stream system.

Description

A kind of gaseous ethane pipeline shutdown restarts system

Technical field

The utility model relates to a kind of gaseous ethane pipeline shutdowns to restart system.

Background technique

In recent years, Market for Ethylene demand is gradually vigorous, and traditional raw material naphtha can not meet in time, and ethane be also compared with Good ethylene raw, therefore refinery is larger to ethane demand.As U.S.'s shale gas revolution arrives, a large amount of ethane can go out after extracting Mouth simultaneously supplies refinery；Meanwhile domestic process for recovering light hydrocarbon is increasingly mature, self-produced ethane can also supplement refinery's raw material notch.Therefore, Ethane conveyance conduit demand of the auxiliary construction from ethane source to refinery is huge.Ethane product in natural gas auxiliary product as rubbing One kind of your lighter weight, saturated vapour pressure is higher, and critical-temperature is about 32 DEG C, and critical pressure is about 4.5MPa, therefore has item Part is conveyed with gas phase or liquid phase state, and phase change conditions are closer to usual operating conditions, under certain operating conditions, if considering It is incomplete, it is easy to happen unexpected phase transformation.Since gaseous ethane pipe operations pressure is lower than liquid ethane pipeline, using gas-phase transport Mode has opposite reliability in security sensitive area.If gaseous ethane operating pressure is excessively high, pipeline is after stopping transportation, pipeline Middle medium easily liquefies because environmental condition acts on, and is formed liquid ethane (part).When restarting, since liquid ethane was vaporizing It will largely absorb heat in journey, and gaseous ethane temperature drop after control valve throttling is larger, thus may cause more serious low temperature Problem；In addition, the boosting during routinely restarting will likely be further exacerbated by liquefaction, make after bulk temperature reduces after stopping transportation It can not normally be established at system pressure, implementation is restarted in influence.Therefore, suitable mode need to be considered, in balanced economy and performance Afterwards, guarantee the safety of gaseous ethane pipeline shutdown.

Currently, to avoid the low temperature condition of gaseous ethane stopped flow injection analysis, consider that the mode taken includes: 1, using low pressure Transport model controls the pipeline pressure under any operation temperature lower than the dew-point pressure under minimum environment temperature, guarantees that medium begins It is in gas phase eventually, fundamentally avoids the occurrence of liquid phase；2, it using high-pressure delivery mode, is reduced by the way of pressure release in stopping transportation Pipeline pressure guarantees that pipeline pressure is in gas phase lower than the dew-point pressure medium under minimum environment temperature always.Both modes Although can be to avoid liquid ethane is formed in pipeline during stopping transportation, there are certain deficiencies: in the 1st kind of mode, use is low The pipeline for pressing mode of movement, under identical throughput rate, to guarantee that velocity interval is reasonable, necessarily amplification has that caliber is larger, Increase pipeline investment；In 2nd kind of mode, pressure release not only wastes certain ethane product when stopping transportation, during restarting After being filled with medium, pipeline pressure is increased, and is also easy to generate liquid ethane, so as to cause Low Temperature Problems.Therefore, it is necessary to further examine Consider the phase control method during restarting, takes into account economy and science.

Summary of the invention

The shortcomings that in order to overcome the prior art, the utility model, which provides a kind of gaseous ethane pipeline shutdown, to be restarted and is System, it is intended to further improve gaseous ethane pipe transportation technology, partial liquefaction restarts technology after supplement gaseous ethane stopping transportation. The utility model vaporizes law of heat release based on liquid ethane in pipeline after stopping transportation, restarts conventional side in conjunction with gaseous medium pipeline Case considers from pipeline pressure control, internal fluid heat exchange and cryogen heating etc., temperature prediction in pipeline is taken to supervise The schemes such as control, the control of pipe end pressure, the control of pipeline starting point replacement amount, during realizing that ethane pipeline shutdown is restarted, product The liquid ethane deposited edges down the throttle temperature control of pressure-heating vaporization and pipe outlet cryogenic gaseous ethane, and using introducing Gaseous ethane gradually builds up temperature field and pressure field, guarantees main pipeline and downstream yard pipeline, equipment safety, and further prop up Support gaseous ethane pipe transportation technology.

The technical scheme adopted by the utility model is a kind of gaseous ethane pipeline shutdown restarts system, including main line Starting point valve group and temperature, pressure flow quantity detecting system, trunk end valve group and temperature, pressure flow quantity detecting system and trunk end Bypass valve group, heat tracing pipe-line system；Wherein:

The main line starting point valve group and temperature pressure detection system include the upstream main line ball valve set gradually on main line, Upstream main line bypass regulator valve, flow transmitter 102, temperature transmitter 103, pressure transmitter 104, and be installed on and stand along the line The temperature transmitter and pressure transmitter of field, the flow transmitter 102, temperature transmitter 103 and pressure transmitter 104 are distinguished It is connect by data line with logic control system；

The trunk end valve group and temperature, pressure flow quantity detecting system include the temperature set gradually on main pipeline Flow transmitter, downstream pressure pick-up after transmitter 2, pressure transmitter 3, downstream main line ball valve 4, downstream main line regulating valve, valve Temperature transmitter, downstream main line ball valve 23 after device, valve, and the bypass second level being arranged in parallel with downstream main line ball valve 23 are adjusted Valve；

The trunk end bypass valve group, heat tracing pipe-line system include the bypass ball valve being arranged in bypass, bypass level-one Regulating valve and four road electric tracing branch pipes being arranged in parallel and the temperature transmitter being arranged on every road branch pipe.

Compared with prior art, the good effect of the utility model is:

The utility model is according to gaseous ethane pipeline shutdown and restarts process characteristic, restarts valve group by setting, can Meet: 1) ethane pipeline improves operating pressure, allows pipeline when stopping transportation to form liquid ethane, reduces caliber, investment reduction；2) again In start-up course, when upstream enters gaseous ethane, ethane is discharged by bypass, to control ethane gas discharge capacity, realization newly enters Ethane and accumulation ethane heat exchange, and by reducing pipeline pressure in a small amount, slow vaporization accumulation liquid ethane；3) restart process In, by bypass stainless steel valve group and tracing system, avoid ethane after throttling from generating low temperature effect to pipe-line system, also certain Degree improves its temperature, and ethane after throttling is avoided to generate low temperature effect to down-stream system；4) during restarting, start-up course The ethane being continuously discharged can enter down-stream system and for driving or producing avoid that ethane being released to fire in stopping transportation initial time Torch reduces waste.

The specific manifestation of the characteristics of the utility model are as follows:

(1) setting science

The utility model proposes a kind of gaseous ethane pipeline shutdowns to restart system and method, based on liquid in pipeline after stopping transportation State ethane chlorination law of heat release restarts conventional scheme in conjunction with gaseous medium pipeline, from pipeline pressure control, internal fluid heat exchange Consider with cryogen heating etc., takes in pipeline temperature prediction monitoring, the control of pipe end pressure, the displacement of pipeline starting point The schemes such as amount control, during realizing that ethane pipeline shutdown restarts, the liquid ethane of accumulation edges down pressure-heating vaporization and pipeline The throttle temperature of low exit temperature gaseous ethane controls, and gradually builds up temperature field and pressure field using the gaseous ethane of introducing, protects Main pipeline and downstream yard pipeline, equipment safety are demonstrate,proved, and further supports gaseous ethane pipe transportation technology.

(2) economy is good

The utility model structure is simple, on the basis of conventional trunk valve group, increase small-bore stainless steel bypass valve group and Electric tracer heating system is bypassed, realizes the reasonable selection of material during restarting.Meanwhile the utility model can promote operation pressure On the basis of power, caliber needed for gaseous ethane pipeline operates normally is further decreased, ethane pipeline investment is greatly reduced.

(3) technology development is pushed

Ethane pipe transportation technology is in view of harmfulness after the physical property and leakage of ethane itself, with conventional gas pipeline Different from, and technique requirement is higher.The pressure vaporization that edges down of the utility model restarts process to reasonable set pipe operations pressure Power, analysis stopping transportation process medium physical change etc. have certain reference role, can push ethane pipeline to a certain extent Conveying technology development.

Detailed description of the invention

The utility model will illustrate by example and with reference to the appended drawing, in which:

Fig. 1 is the schematic diagram that a kind of gaseous ethane pipeline shutdown restarts system.

Specific embodiment

A kind of gaseous ethane pipeline shutdown restarts system, as shown in Figure 1, comprising: upstream main line ball valve 100, upstream are dry Line bypass regulator valve 101, flow transmitter 102, temperature transmitter 103, pressure transmitter 104, main pipeline 1, temperature pick-up Flow transmitter 6, downstream pressure transmitter after device 2, pressure transmitter 3, downstream main line ball valve 4, downstream main line regulating valve 5, valve 19, temperature transmitter 20, bypass ball valve 7, bypass level-one regulating valve 8, bypass branch 9/18, bypass electric tracing branch pipe 10/ after valve 11/12/13, temperature transmitter 14/15/16/17, pre-reservation pressure stabilizer interface 21, downstream main line ball valve 23, bypass two are bypassed Grade regulating valve 22.

Wherein, upstream main line ball valve 100, upstream main line bypass regulator valve 101, flow transmitter 102, temperature transmitter 103, the composition main line starting point valve group such as pressure transmitter 104, main line 1 and temperature pressure detection system, are responsible in main line upstream pair Pipeline shutdown is actuated for controlling, and the parameters such as the pressure to ducts upstream, flow and temperature are monitored.

Specifically, ball valve 100 is full-bore electrical ball valve, is connect with main line, is kept in stopping transportation with during restarting It closes, (normal operation) is opened after the completion of restarting；Regulating valve 101 is small diameter electric regulating valve, is installed on the side of ball valve 100 On the road, main function is introducing upstream ethane gas during restarting, and controls gas flow；Flow transmitter 102, temperature Degree transmitter 103, pressure transmitter 104 are directly installed on main line, to stopping transportation, ducts upstream when restarting and operating normally Flow, temperature and pressure parameter are monitored, and data reach logic control system.

Wherein, main pipeline 1, temperature transmitter 2, pressure transmitter 3, downstream main line ball valve 4, downstream main line regulating valve 5, Temperature transmitter 20, downstream main line ball valve 23, bypass second level are adjusted after flow transmitter 6, downstream pressure transmitter 19, valve after valve Valve 22 forms trunk end valve group and temperature, pressure flow quantity detecting system.It is responsible for that main line channel is truncated in stopped flow injection analysis, and Ball valve pressure at both sides, temperature and the flow of trunk end during monitoring is restarted respectively, are also responsible for the offer when operating normally Medium main channel, factory's medium pressure regulation of advancing of going forward side by side.

Specifically, main pipeline 1 is airbreak laying, connects ethane conveyance conduit；Temperature transmitter 2 and pressure transmitter 3 It is installed on main line, pipe parameter when detecting stopping transportation, restarting and operate normally；Downstream main line ball valve 4 is that full-bore is electronic Ball valve is horizontally mounted, and is welded to connect, and when normal operation opens；Downstream main line regulating valve 5 is Electronic control, is horizontally mounted, and is welded Connection is played the role of adjusting into factory's pressure medium when operating normally；Flow transmitter 6 after valve, downstream pressure transmitter 19, Temperature transmitter 20 is installed on the main line in 5 downstream of downstream main line regulating valve after valve, in stopping transportation, is restarted and is operated normally Shi Chixu is monitored the medium parameter at this in pipeline；Downstream main line ball valve 23 is full-bore electrical ball valve, is horizontally mounted, It is welded to connect, when normal operation opens；Bypass second level regulating valve 22 is installed on the bypass of the downstream main line ball valve 23, using electricity Dynamic control, is only opened during restarting, and is acted synergistically with upstream main line bypass regulator valve 101, after controlling ethane chlorination Discharge rate can also further assist the accurately control pressure for vaporization of bypass valve 8.

Wherein, ball valve 7, bypass level-one regulating valve 8, bypass branch 9/18, bypass electric tracing branch pipe 10/11/12/ are bypassed 13, temperature transmitter 14/15/16/17 is bypassed, pre-reservation pressure stabilizer interface 21 forms trunk end and bypasses valve group, heat tracing pipe Road system.It is responsible for setting after the ethane chlorination accumulated in main pipeline and heating for downstream during restarting by pressure difference It is standby to drive to use, it is also convenient for upstream main pipeline and receives room temperature ethane, gradually build up the pressure that gaseous ethane pipeline normally conveys Field and temperature field.

Specifically, bypass ball valve 7 is electrical ball valve, and normal status is opened during restarting, and is welded to connect；Bypass Level-one regulating valve 8 is installed on ball valve downstream, for controlling upstream mains pressure, promotes liquefied ethane vaporization in pipeline, convenient for upper Trip room temperature ethane can progress into pipeline, medium temperature in riser tubing；Electric tracing branch pipe 10/11/12/13 is bypassed after valve is 4 road branch pipes of mean allocation, material is stainless steel, is wrapped up using electric tracing temperature control and insulating layer, setting bypass temperature on pipeline Transmitter 14/15/16/17, for detect decompression after low temperature ethane gas heating effect, lateral merge after shunt valve Pre-reservation pressure stable can interface on road, for connecting pressure stable can in the lesser situation of tube capacity, the pressure stable can is Built-in membrane formula gas reservoir, by nitrogen punching press in diaphragm, the outer ethane pressure of balancing diaphragm.

Wherein, temperature transmitter, the pressure transmitter real time monitoring of each yard, composition temperature, pressure monitoring on the way are along the line System acts synergistically with the mains pressure transmitter, temperature transmitter.

Meanwhile this system further includes the logic control system of transducer signal transmission, processing and valve control.

The working principle and the course of work of the utility model are as follows:

(1) to keep pure gas-phase transport, gaseous ethane pipeline keeps enough temperature when operating normally, to avoid medium Temperature is lower than dew-point pressure；After gaseous ethane pipeline shutdown, (winter) is influenced by ground temperature, medium temperature constantly reduces, and presses Power reduction amplitude is unobvious, and medium enters the intermediate region of dew point line and bubble point line, forms the heterogeneous fluid of Partial Liquid Phase.If will Pipeline pressure further decreases, and medium can be avoided to liquefy in stopping transportation, and the cost paid is to expand caliber, and huge investment is caused to increase Add.Therefore the content of the utility model is proposed.

(2) during restarting, if needing to carry out integral pressure there are liquefied ethane in pipeline and edging down, to allow Medium enters gas phase state in pipeline；Pipeline internal medium pressure is reduced in such a way that downstream adjusts back pressure, and to pressure drop amplitude It is controlled, otherwise the excessively high pressure range of decrease will cause inner wall of the pipe temperature to be greatly reduced due to vaporization, this is to pipeline material It will cause influence.

(3) ethane vaporized passes through downstream bypass regulating valve discharge line, and to reduce pipeline pressure, medium is whole in pipeline Vaporization；The ethane of discharge has small size temperature drop after regulating valve, therefore is provided with branch's stainless steel tube on pipeline after regulating valve Road, and electric tracing and insulating layer are configured, utmostly to reduce influence of the cryogenic media to pipeline and downstream unit；On meanwhile Trip can continuously be filled with room temperature ethane, to keep in pipeline gaseous ethane to flow, and further in riser tubing ethane temperature, add Restart speed fastly.

(4) each point temperature and pressure during being restarted by temperature transmitter on the way and pressure transmitter monitoring, when Relatively stable temperature field and pressure field are completely established, and determines pipeline technology condition substantially by simulating calculation After liquefaction condition, system back pressure can be adjusted to accidental conditions, and further monitor pipe temperature field；

(5) when pipe temperature field reaches nominal situation requirement, bypass is closed, opens main line, system enters normal operation Mode restarts completion.

The utility model relates to gaseous ethane pipeline shutdown Restart Method, including following main contents:

Step 1: it after main line stopping transportation, by temperature transmitter everywhere, pressure transmitter monitoring parameter, grasps pipeline and stops All fronts pressure under defeated, state of temperature；It according to the monitoring pressure and temperature before restarting, is analyzed, is simulated in pipeline by software Ethane liquefaction amount and determining suitable step-down value, the pressure value after decompression preferably control below the corresponding bubble point pressure of ground temperature 0.1MPa；

Step 2: before restarting, the electrical ball valve (main line ball valve 100 and main line ball valve 4) at main line both ends is kept to close；Root Driving process according to downstream unit and the safety pressure value (avoiding low temperature) according to step 1 calculating, set main line downstream damper System back pressure after 5；

Step 3: before restarting, downstream bypass ball valve 7 and bypass level-one regulating valve 8 is opened, the second in stopping transportation main line is reduced Alkane pressure；Meanwhile second level regulating valve 22 is bypassed by downstream main line, by ethane pressure reduction to the corresponding pressure of driving process； Continued vaporization after ethane decompression in main line, and main line upstream is filled with room temperature ethane, the second after the throttling of main line downstream bypass regulating valve 8 Alkane temperature decreases, and electric tracing branch pipe 10/11/12/13 is bypassed after opening valve, utilizes bypass temperature transmitter 14/15/16/ 17 carry out monitoring temperature, carry out temperature control to low temperature ethane.

Step 4: it when small flow is restarted, bypasses second level by upstream main line bypass valve 101, downstream main line and adjusts Valve 22 controls ethane replacement amount, and by the way that completely pressure transmitter monitors pressure parameter everywhere, guarantees that pressure meets step everywhere Goal pressure described in one grasps in replacement process ethane medium in main line by temperature transmitter monitoring temperature parameter everywhere Temperature rises rule；Further, it can be used for small-bore pipeline (small tube capacity) by by manostat access system interface 21 Pressure stability contorting under operating condition；

Step 5: when main line everywhere temperature transmitter parameter show have built up all fronts steady temperature field after, be gradually increased Ethane throughput rate makes all fronts temperature field further to normal operating operating condition；

Step 6: lifting system back pressure, all fronts pressure field and temperature field are further to normal operating operating condition；

Step 7: when main line everywhere temperature transmitter parameter show have built up completely normal delivery temperature field after, open Upstream main line ball valve 100, downstream main line ball valve 4, main line regulating valve 5, and each bypass valve group and pipeline are progressively closed off, close heat tracing System, by lifting system back pressure, all fronts pressure field restores normal, and restarting process steadily terminates.

The utility model is based on liquid ethane vaporization law of heat release and restarts operating process, out of pressure control, fluid Portion's heat exchange and cryogen heating etc. consider, realize and accumulate edging down for liquid ethane in pipeline during stopped flow injection analysis The throttle temperature control function of pressure-heating vaporization and pipe outlet cryogenic gaseous ethane guarantees main pipeline and downstream yard pipe Road, equipment safety.

Claims (6)

1. a kind of gaseous ethane pipeline shutdown restarts system, it is characterised in that: including main line starting point valve group and temperature, pressure stream Amount detection systems, trunk end valve group and temperature, pressure flow quantity detecting system and trunk end bypass valve group, heat tracing pipeline system System；Wherein:

The main line starting point valve group and temperature pressure detection system include the upstream main line ball valve set gradually on main line, upstream Main line bypass regulator valve, flow transmitter (102), the first temperature transmitter (103), first pressure transmitter (104), Yi Jian Temperature transmitter and pressure transmitter loaded on yard along the line, the flow transmitter (102), the first temperature transmitter (103) It is connect respectively by data line with logic control system with first pressure transmitter (104)；

The trunk end valve group and temperature, pressure flow quantity detecting system include the second temperature set gradually on main pipeline Flow pick-up after transmitter (2), second pressure transmitter (3), the first downstream main line ball valve (4), downstream main line regulating valve, valve Temperature transmitter, the second downstream main line ball valve (23) after device, downstream pressure transmitter, valve, and with the second downstream main line ball valve (23) the bypass second level regulating valve being arranged in parallel；

The trunk end bypass valve group, heat tracing pipe-line system include the bypass ball valve being arranged in bypass, bypass level-one adjusting Valve and four road electric tracing branch pipes being arranged in parallel and the temperature transmitter being arranged on every road branch pipe.

2. a kind of gaseous ethane pipeline shutdown according to claim 1 restarts system, it is characterised in that: the four roads electricity Pressure stable can interface is set on bypass duct after the merging of heat tracing branch pipe, for connecting pressure stable can.

3. a kind of gaseous ethane pipeline shutdown according to claim 2 restarts system, it is characterised in that: the pressure is steady Determining tank is built-in membrane formula gas reservoir.

4. a kind of gaseous ethane pipeline shutdown according to claim 1 restarts system, it is characterised in that: the electric tracing Branch pipe material is stainless steel, is wrapped up using electric tracing temperature control and insulating layer.

5. a kind of gaseous ethane pipeline shutdown according to claim 1 restarts system, it is characterised in that: the upstream is dry Thread ball valve is full-bore electrical ball valve, and the upstream main line bypass regulator valve is small diameter electric regulating valve.

6. a kind of gaseous ethane pipeline shutdown according to claim 1 restarts system, it is characterised in that: the main line pipe Road is airbreak laying, connects ethane conveyance conduit；The first downstream main line ball valve (4) is full-bore electrical ball valve, level peace Dress is welded to connect；The downstream main line regulating valve is Electronic control, is horizontally mounted, and is welded to connect；The second downstream main line ball Valve (23) is full-bore electrical ball valve, is horizontally mounted, and is welded to connect.