CN211146096U

CN211146096U - Automatic control device for preventing condensation and heat tracing steam in oil refinery oil pipeline accidents

Info

Publication number: CN211146096U
Application number: CN201921690176.9U
Authority: CN
Inventors: 雷泽永
Original assignee: Individual
Current assignee: Individual
Priority date: 2019-10-10
Filing date: 2019-10-10
Publication date: 2020-07-31
Anticipated expiration: 2029-10-10

Abstract

An oil refinery oil pipeline accident anti-condensation heat tracing steam automatic control device comprises a production workshop heat tracing control device, a single oil pump heat tracing control device and an instrument pressure guide pipe heat tracing anti-condensation device, wherein an original heat tracing steam pipeline is modified, a plurality of heat tracing branch lines are divided from a main steam pipeline, each branch line is in a port-to-port connection with one oil pump, a control valve is arranged on each branch line, and a pipeline behind the valve is divided into steam branch lines which are respectively communicated with an inlet pipe and an outlet pipe of the pump to implement oil pipeline heat tracing; an interlocking automatic controller is arranged, automatic on-off control is realized by interlocking the flow of the flowmeter, the operation is accurate, manual operation is not needed, and the waste of steam is reduced; in order to prevent the condensation of the pressure pipe, a special water jacket is designed, and the anti-freezing and anti-condensation functions of the pressure pipe are realized for heat tracing and heat preservation of the pressure pipe. The utility model discloses think about ingenious, the investment transformation is with low costs, easy implementation, can realize automatic control companion's heat operation, effectively saves companion's heat steam, reduce cost, and the operation is accurate errorless, ensures to produce normal safety and goes on.

Description

Automatic control device for preventing condensation and heat tracing steam in oil refinery oil pipeline accidents

Technical Field

The utility model belongs to the technical field of oil refining chemical production, a automatic control device is related to, especially relate to an oil refinery oil pipe way accident prevents congealing automatic control device who accompanies hot steam.

Background

The control of oil pipelines and instruments is a key device for realizing automatic continuous production in the petroleum processing process of refineries. For transporting various oil products, each refinery has an large oil transportation pipe network with several tens of meters to several kilometers and a total length of several kilometers among various oil refining equipment within several kilometers. The instrument control is to transmit the operation parameters (pressure, flow, liquid level and temperature) of various devices and pipelines to a computer through signal transmission, so as to realize self-functionalized operation and finish the petroleum processing process. Wherein, the pressure, the flow and the liquid level in the operation parameters are all realized by feeding the liquid into the brain in a pressure transmission mode. In the pressure transmission process, a pressure signal of a relevant facility is transmitted to a pressure transmitter through a liquid medium in a special pipeline (a pressure guide pipe specially called in the industry), and then the pressure signal is converted and transmitted to a computer. The pressure guiding pipes are divided into two types: if the medium in the equipment is steam, the medium in the guide pipe is water (hereinafter referred to as water guide pipe), and similarly, if the medium in the equipment is oil, the medium in the pressure guide pipe is oil (hereinafter referred to as oil guide pipe). During normal production, the largest potential for oil lines and impulse lines is left behind and over congealed: the oil in the steam guide pipe can be frozen when the temperature of the oil is close to the freezing point of the oil, and the water in the steam guide pipe of the steam equipment can also be frozen when the temperature of the water is lower than zero.

The continuous production period of a refinery is usually 3-5 years, and any oil pipeline and pressure guiding pipe are absolutely not allowed to freeze during the continuous production period, otherwise, the safe production of a vehicle or a whole plant is influenced, and the economic loss is caused. There are two factors causing the congealing of oil pipe and pressure pipe:

the first is the air temperature at the refinery site. In northern areas, the temperature is lower than that in southern areas, the freezing point of oil products is higher than that of water, and the oil products are easier to freeze. When the temperature is close to the oil product solidifying point, the oil product is frozen. Similarly, when the air temperature approaches zero, water is easy to freeze.

The second is a production accident. When the oil in the pipeline does not flow due to the production accident of a refinery, firstly, a heavy oil pipeline (comprising an oil conduit, the same applies below) starts to be frozen and congealed due to heat dissipation loss, and then, the medium and partial light oil products are also frozen and congealed, and consequently, various oil pipelines are frozen and congealed in succession. According to the different oil mediums, the freezing point of 7 kinds of light and heavy oil products is above zero. These 7 classes of light and heavy oils are: 1. asphalts; 2. slag oils; 3. lubricating oils; 4. wax oils; 5. crude oil, 6, benzenes 7, diesel and the like. Wherein, asphalt and residual oil can freeze and congeal in any season.

After decades of safe production operation, an effective anti-condensation technology, namely a heat tracing anti-condensation and anti-freezing technology for steam of an oil pipeline and an instrument pressure pipe, is accumulated in a refinery in China. The heat tracing technology adopted by refineries is that a main pipe (a pipeline with a medium possibly frozen) is accompanied by a small steam tracing pipe, the two pipes are combined together for heat preservation, the heat energy emitted by steam is utilized to compensate the heat dissipation loss of the two pipelines, the medium of the main pipe is ensured to be higher than the freezing point of the main pipe, and the purposes of preventing freezing and ensuring safe production are achieved. At present, the heat tracing of the production device of a refinery adopts a regional (referring to a production device region, a system pipe network region and an oil tank region) heat tracing mode, namely, a plurality of steam branches are led out from one main steam pipeline by regions to implement heat tracing on a plurality of pipelines (oil pipes and pressure guide pipes) in the relevant region, namely, the types and the production flows of the oil pipelines and the pressure guide pipes are not distinguished, and the steam pipelines are connected nearby for heat tracing, so that the heat tracing steam pipeline is shortest. The result is that multiple steam lines are heat traced to different types of lines and impulse lines in the same area. In addition, the heat tracing steam is not a special line, and other steam users which cannot be interrupted throughout the year can be provided besides pipeline heat tracing. In order to ensure safe production and guarantee that an oil delivery pipe is not frozen, a refinery adopts a manual operation mode to perform intermittent and uninterrupted continuous steam tracing on an oil pipe and a pressure guide pipe according to seasonal differences within 3-5 years from the start of a production device to the stop of the production device. The heat tracing consumes a large amount of steam, the heat tracing steam consumption of refineries is about 30-50t/h due to different scales, the energy consumption cost of large refineries is about 0.5-1 hundred million yuan because the large refineries exceed 50 t/h. And the current pipeline heat tracing technology is lagged behind, which causes more than 80% of steam waste.

SUMMERY OF THE UTILITY MODEL

The utility model aims to solve the technical problem that an automatic control device of oil plant oil pipe way accident anti-condensation tracing steam is provided, tracing accessible instrument automatic control system operates, effectively saves tracing steam, reduce cost.

The utility model provides a technical scheme that above-mentioned technical problem adopted does: the utility model provides an oil refinery oil pipe way accident prevents congealing automatic control device of heat tracing steam, wherein the oil pipe way includes the entry oil pipe and the pump export pipeline of oil pump, and entry oil pipe is connected with the oil outlet of refining equipment, and pump export pipeline divides two the tunnel: go the same way through second flowmeter, first oil pipe return-back equipment, another way, through first flowmeter, product play device pipeline, carry oil product to produce workshop, via system pipe network district, reentrant oil tank district pipeline, divide two ways to go different oil tank internal storage, its characterized in that: the automatic control device comprises a production workshop heat tracing control device, a single oil pump heat tracing control device and an instrument pressure guide pipe heat tracing condensation preventing device, wherein the production workshop heat tracing control device comprises a special heat tracing steam main pipeline and a first locking automatic controller between the flow of a raw material pump and the opening and closing of a plurality of heat tracing steam valves, a plurality of steam heat tracing branch pipes are led out from the steam main pipeline, each steam heat tracing branch pipe is provided with a control valve, the first locking automatic controller is connected with each control valve through a signal line and controls the opening and closing of the control valves through the flow change of an outlet flow meter of the raw material pump, when the production workshop has large accident stop, the raw material pump stops running, the outlet flow meter display value of the raw material pump drops to zero, the first locking controller automatically sends an instruction to the control valves on the heat tracing branch pipes, the control valves are opened, and the steam heat tracing branch pipes corresponding to the raw material pump open the oil inlet pipe and the raw material outlet pipe of the raw material pump for heat tracing, meanwhile, other steam heat tracing branch pipes are opened to perform heat tracing on pipelines at the inlet and the outlet of other oil pumps, when workshop production is recovered to be normal and the display value of an outlet flowmeter is normal, the first linkage automatic controller sends out an instruction, and the control valve closes the heat tracing;

the single oil pump heat tracing control comprises a steam branch line led out from a steam main pipe, and the steam branch line is divided into three paths after flowing out through a second interlocking automatic control valve: the first path gives the oil pipe of the product discharging device to accompany heat to the pipeline of the oil tank area through a first steam pipeline, and the heat-tracing condensation hot water is discharged through a first steam trap; the second path of heat tracing firstly carries out heat tracing on the pump outlet pipeline through a second steam pipeline, then carries out heat tracing on the first oil pipe, and enters a second steam trap downwards at the oil refining equipment; the third path of heat tracing steam enters the inlet oil pipe for tracing heat through a first heat tracing steam pipe and a steam valve through a third steam pipeline, enters the third steam trap at the inlet of the oil pump, and is closed by the interlocking automatic control valve and closed by the three paths of heat tracing when the production is normal; when the oil pump stops running due to an accident and the flow of an oil pump flow meter is lower than a set value, the second interlocking automatic control valve is opened, and the three paths of heat tracing are opened for heat tracing; the instrument pressure pipe heat tracing condensation preventing device comprises a water jacket and a circulating water pipe connected with the water jacket, wherein the water jacket and the circulating water pipe are filled with water, the water jacket is tightly attached to the main pipeline and is positioned on one side of an instrument, the circulating water pipe is bound with the pressure pipe used for transmitting an instrument pressure signal, and heat in the main pipeline is transferred to the circulating water in the circulating water pipe through the water jacket to perform heat tracing on the pressure pipe.

As an improvement, the number of the steam heat tracing branch pipes led out from the steam main pipeline is the same as that of the oil pumps, and each steam heat tracing branch pipe corresponds to one oil pump.

Preferably, the set value of the outlet flow meter of the raw material pump is 0-50% of the normal flow, and the set value of the flow meter of the oil pump is 0-50% of the normal flow.

As an improvement, a first flow meter and a second flow meter are respectively installed on a product discharging and loading oil pipe and a first oil pipe in the single oil pump heat tracing control, branch pipes for supplying oil to the oil pump flow meter, the first flow meter and the second flow meter for pressure pipe heat tracing are respectively arranged on a first steam pipeline and a second steam pipeline, and when a second interlocking automatic control valve is opened, the three branch pipes for heat tracing are simultaneously opened for heat tracing.

And further, the three heat tracing branch pipes flow through the pressure guide pipe and then enter the fourth steam trap downwards.

The water jacket is an annular water jacket with a half-moon-shaped section, the inner diameter of the water jacket is the same as the outer diameter of the main pipeline, the water jacket is sleeved on the main pipeline, the inner wall of the water jacket is tightly attached to the outer surface of the main pipeline, and a tightly attached heat transfer contact surface is formed between the inner wall of the water jacket and the outer wall of the main pipeline.

Furthermore, a heat-insulating layer is additionally arranged outside the water jacket, and two ends of the circulating water pipe are respectively connected with two sides of the water jacket to form an O-shaped circulating water pipe.

And finally, the meter is a flowmeter or a pressure gauge, the main pipeline is an oil conveying pipe or a steam pipe, and the meter is connected with the pressure transmitter through a pressure guide pipe.

Compared with the prior art, the utility model has the advantages of: the original heat tracing steam pipeline is reformed, a plurality of heat tracing branch lines (the number of the branch lines is equal to that of the oil pumps) are separated from a main steam pipeline, each branch line is connected with one oil pump, a control valve is arranged on each branch line, and a steam branch line separated from a pipeline behind the valve is respectively communicated with an inlet pipe and an outlet pipe of the pump to implement oil pipeline heat tracing; in addition, when the branch heat tracing pipe passes through the oil pipe meter, a small branch pipe is led out additionally to provide pressure guide pipe heat tracing of the meter; the flow interlocking automatic controller is arranged, the automatic control of the switch of the control valve is realized through interlocking, the operation is accurate, manual operation is not needed, and the waste of steam is reduced; in order to prevent the condensation of the pressure pipe, a special water jacket is designed, and the anti-freezing and anti-condensation functions of the pressure pipe are realized for heat tracing and heat preservation of the pressure pipe. The utility model discloses think about ingenious, the investment transformation is with low costs, easy implementation, has effectively solved the oil pipe way companion heat steam of refinery apparatus district and system pipe network district within range and has opened, stop the problem of operation, can realize automatic control and carry out companion heat operation, effectively saves companion heat steam, and reduce cost improves the productivity effect, and the concurrent operation is accurate errorless, ensures the normal safety of production and goes on.

Drawings

FIG. 1 is a flow chart of heat tracing instrument control in a production workshop provided by the utility model;

FIG. 2 is a schematic diagram of the oil pump line heat tracing;

FIG. 3 is a schematic structural diagram of condensation heat tracing prevention of a pressure guide pipe of the instrument;

FIG. 4 is a schematic structural view of the water jacket of FIG. 3;

FIG. 5 is a schematic diagram of a modified front oil pump pipeline heat tracing structure;

FIG. 6 is a schematic structural diagram of the improved front instrument pressure guide pipe for preventing condensation heat tracing.

Detailed Description

The present invention will be described in further detail with reference to the following embodiments.

As shown in figures 1-4, an automatic control device for preventing condensation and heat tracing steam in oil refinery oil pipeline accidents comprises three parts, namely a production workshop heat tracing control device, a single oil pump heat tracing control device and an instrument pressure pipe heat tracing and condensation preventing device.

Wherein the production workshop heat tracing control, as shown in figure 1, comprises a main steam pipeline 1 and a first interlocking automatic controller 28, a plurality of steam heat tracing branch pipes are led out from the main steam pipeline 1, each steam heat tracing branch pipe corresponds to an oil pump, each steam heat tracing branch pipe is provided with a control valve 3, 4, 5, 6, the first interlocking automatic controller 28 is connected with each control valve 3, 4, 5, 6 through a total signal line 10 and signal lines 10-6, 10-7, 10-8, 10-9, and carries out open and close control on the control valves 3, 4, 5, 6 through the flow change of an outlet flowmeter 27 of a raw material pump 26, when a large accident stop occurs in the production workshop, the raw material pump 26 stops running, and the display value of the outlet flowmeter of the raw material pump 26 drops to be lower than 50%, the interlocking automatic controller 28 sends an instruction to the control valves 3 on the steam heat tracing branch pipes, the control valve 3 is opened, the steam heat tracing branch pipe corresponding to the raw material pump 26 is opened and divided into two paths, wherein one path of branch pipe 24 is used for tracing heat to the inlet oil pipe 22 of the raw material pump 26, the steam enters the steam trap 25 from the inlet of the inlet oil pipe 22 of the raw material pump 26, the other path of branch pipe 23 is used for tracing heat to the outlet oil pipe 21 of the raw material pump 26, the steam enters the other steam trap 15 from the end point of the outlet oil pipe 21 of the raw material pump 26, and simultaneously, other control valves 4, 5 and 6 are also opened, other steam tracing branch pipes are opened to carry out tracing heating on inlet and outlet pipelines of other oil pumps and pressure guide pipes in the pipelines, when the workshop production is recovered to be normal and the display value of the outlet flowmeter 27 is normal, the first interlocking controller 28 sends an instruction, the control valves 3, 4, 5 and 6 are closed, the heat tracing steam in the whole production workshop is stopped, the purpose of saving steam is achieved, the number of workshop oil pumps is the same as that of the control valves, and one control valve corresponds to the heat tracing starting and stopping operation of one oil pump.

The oil pipeline of a single oil pump is shown in fig. 2, and comprises an inlet oil pipe 2.1 of the oil pump 2 and a pump outlet pipeline 2.2, wherein the inlet oil pipe 2.1 is connected with an oil outlet of the oil refining equipment 27, the pump outlet is divided into two paths through a flow meter 2d, and the pipeline 2.2 is divided into two paths: one path returns to the oil refining equipment 27 through the second flowmeter 30 and the first oil pipe 2.3, the other path passes through the first flowmeter 40, a product outlet device pipeline 80 conveys oil products to a production workshop, passes through a system pipe network area, and then enters an oil tank area pipeline 90, the oil products are stored in different oil tanks in two paths, the single oil pump heat tracing control comprises a steam branch line 20 led out from a steam main pipe, and the steam branch line is divided into three paths after flowing out through the second interlocking automatic control valve 14: the first path gives the oil pipe 80 of the product discharging device through the first steam pipeline 12 and carries out heat tracing to the pipeline 90 of the oil tank area, and the heat tracing condensed hot water is discharged through the first steam trap 2 a; the second path of heat tracing firstly carries out heat tracing on the pump outlet pipeline 2.2 through the second steam pipeline 11, then carries out heat tracing on the first oil pipe 2.3, and enters the second steam trap 2b downwards at the oil refining equipment 27; the third path of heat tracing steam passes through a steam branch line 20, passes through a steam valve 16, enters a heat tracing steam pipe 10 to supply heat to an inlet oil pipe 2.1, enters a third steam trap 2c from an inlet of an oil pump 2, and when the production is normal, a second interlocking self-control valve 14 is closed, and the three paths of heat tracing are closed; when the oil pump 2 stops running due to an accident and the flow of an oil pump flow meter 2d is lower than 50%, the second interlocking automatic control valve 14 is opened, and the three paths of heat tracing are opened for heat tracing; in addition, the first steam pipeline 12 and the second steam pipeline 11 are respectively provided with branch pipes for heat tracing of the pressure guide pipes of the first flowmeter 40, the pump outlet flowmeter 2d and the second flowmeter 30, and when the first interlocking self-control valve 14 is opened, the three branch pipes for heat tracing are simultaneously opened for heat tracing of the pressure guide pipes of the flowmeters.

The instrument pressure pipe heat tracing and condensation preventing device is shown in fig. 3 and 4, a metering instrument 16 is arranged on a main pipeline 2, a pressure signal of the metering instrument is transmitted to a pressure transmitter 18 through a pressure pipe 3, and the pressure pipe 3 is filled with oil products of the main pipeline 2, does not flow and is easy to freeze. In order to prevent the pressure pipe from freezing when oil in the main pipe 2 does not flow in an accident state, a heat tracing steam pipe 14 is led out beside the metering instrument 16 to heat the pressure pipe 3, and condensed water enters the fourth steam trap 1.5 to be discharged. The pressure guide pipe condensation preventing device during normal production comprises a water jacket 1a and a circulating water pipe 1b connected with the water jacket 1a, wherein the water jacket 1a and the circulating water pipe 1b are filled with water, the water jacket 1a is an annular water jacket with a half-moon-shaped section, the inner diameter of the water jacket 1a is the same as the outer diameter of the main pipeline 2, the water jacket 1a is tightly attached to one side of a metering instrument 16 of the main pipeline 2, a heat insulation layer is additionally arranged outside the water jacket 1a, and a tightly attached heat transfer contact surface 15 is formed between the inner wall of the water jacket 1a and the outer wall of the main pipeline 2; the two ends of the circulating water pipe 1b are respectively connected with the two sides of the water jacket 1a to form an O-shaped circulating water pipe, the circulating water pipe 1b is bound with a pressure guide pipe 3 used for transmitting instrument pressure signals, heat in the pipeline 2 is transmitted into the water jacket 1a through a contact surface 15 to uninterruptedly heat circulating water in the water jacket to generate power, the circulating water in the circulating water pipe 1b is enabled to ceaselessly flow, and heat tracing is carried out on the pressure guide pipe 3; wherein the meter 16 is a flow meter or a pressure gauge, and the main pipeline 2 is an oil pipeline or a steam pipe.

Comparative example 1

The structure of the oil pump pipeline heat tracing before modification is shown in fig. 5, oil products of the oil refining equipment 27 enter the oil pump 18 from a pump inlet pipeline 3a, enter a flow meter 60 after being pressurized by a pump, a pump outlet pipeline 3b is divided into two loops, one loop enters a tower through a tower return pipe 3c, the other loop is an outlet device pipeline 3d (oil products are sent into a tank area for storage), and are divided into two paths after entering the oil tank area through a system pipeline network area, and the pipeline 3e and the pipeline 3f enter different oil tanks respectively.

In the device area, heat tracing steam is discharged from a steam pipe A and enters a heat tracing steam pipe 41 through a manual steam valve (a steam valve is called below) a to perform heat tracing on a pump inlet pipeline 3 a. The condensation water of the heat tracing steam enters the steam trap 51 to be discharged (the flow of the steam entering the steam trap is the same, and the description is not repeated), the other outlet oil pipe is used for tracing, the heat tracing steam is discharged from the steam pipe B, enters the heat tracing pipe 42 through the steam valve B to heat the pump outlet pipeline 3B and the return pipe 3c of the return tower, and the condensation water of the heat tracing steam enters the steam trap 52 to be discharged.

In the system pipe network area, heat tracing steam is discharged from the steam pipe C and enters the heat tracing pipe 44 through the steam pipe 43 and the steam valve C to give heat tracing to the oil pipe 3d of the device; in the oil tank area, the heat tracing steam is discharged from the steam pipe D, enters the heat tracing pipe 45 through the steam valve D to trace heat for the oil pipeline 3e in the tank area, and the other heat tracing steam is fed for the pipeline 3f through the steam inlet pipe 46 of the steam valve.

In comparison, the heat tracing steam of comparative example 1 needs to be manually turned on and off, cannot be automatically controlled, and cannot be turned off according to the production conditions, so that the waste of steam is large.

Comparative example 2

Before transformation, instrument heat pipe heat tracing is carried out, as shown in fig. 6, a metering instrument is arranged at a position of a main oil pipe 2, a pressure signal of the metering instrument is transmitted to a pressure transmitter 18 through a pressure guide pipe 3, a heat tracing steam pipe E is led out beside the metering instrument, steam of the metering instrument enters a heat tracing steam pipe 100 through a manual steam valve 5A to carry out heat tracing on the pressure guide pipe, and condensed water of the steam enters a steam trap 55 to be discharged.

The heat tracing consumes a large amount of steam, the consumption of the heat tracing steam is about 30-50t/h due to different sizes of refineries, the consumption cost of large refineries exceeds 50t/h, and the energy consumption cost is about 0.5-1 million yuan.

The heat tracing steam pipe is usually a Dg10-25 steel pipe, and the starting end of the heat tracing steam pipe is provided with a manually operated valve for starting and stopping heat tracing of the pipeline. The heat tracing steam is mostly low pressure steam of 1.0Mpa, and the other few is medium pressure steam of 3.5 Mpa.

The current pipeline heat tracing technology falls behind, which causes more than 80% of steam waste.

The following is a detailed description of the concept, principle and innovation points of the present invention:

firstly, principle:

the utility model discloses a heat tracing anti-condensation technology of oil pipes (oil conveying pipelines and instrument pressure pipes) related to an oil pump in an oil refinery production device area under an accident condition, which aims to save heat tracing steam in the production period, wherein during normal production, the temperature of oil products in the oil pipes is 120 plus 400 ℃, and the pipelines cannot be frozen under the uninterrupted flow state, so that the heat tracing can be stopped, and the purpose of saving steam is achieved. The water or oil in the pressure guide pipe is in a non-flowing state, the utility model discloses a novel prevent condensing pressure guide pipe that itself has the automatic function of getting heat, also can stop the heat tracing steam during normal production, reach the purpose of economizing on steam equally. The two types of heat tracing are stopped, 80 percent of heat tracing steam can be saved for the refinery, the pollution and the improvement of combustion products are reduced, and considerable economic benefit is brought.

The above idea is only applicable to normal production conditions, and is not applicable to production accident conditions. When the device has production accident, for example, the oil pump stops the operation, causes the intraductal oil to stop flowing, because heat dissipation loss, the pipeline (including the connecting pipe) temperature is lower and lower, finally causes the congealing accident. Therefore, the utility model discloses a technique of preventing congealing is prevented to the companion's heat under the oil production accident situation specially, ensures to stop during normal production the technique of companion's heat steam and can implement.

Second, transformation thought and concrete transformation

In normal production, oil pipeline heat tracing is unnecessary, and obviously, steam is wasted. Therefore, the device adopts an instrument control technology to stop the heat tracing steam, so as to achieve the purpose of saving the steam. When an accident occurs at one part of the production workshop or the production workshop, the heat tracing steam valve is opened to heat the pipeline and the pressure guide pipe under the accident working condition, so that the freezing of the pipeline and the pressure guide pipe is avoided. When the normal production is recovered after the accident is processed, the related pipeline is closed to accompany the hot steam, so that the steam is saved.

The production workshops of an oil refinery are provided with hundreds to thousands of oil pumps, tens of millions of oil pipes and pressure guiding pipes, the production flow is complicated, the production accidents are few, but the positions and the time of the accidents are unpredictable. Therefore, it is not feasible to manually turn on and off the heat tracing operation of the pipeline. Therefore, the utility model discloses a pipeline heat tracing flow who is operated by instrument automatic control system, and technically more standard.

Oil pipes of refineries can be divided into three categories according to the difference between the production flow and the flow state:

the first type: an oil pipeline for continuously conveying oil products. The oil pipeline is an oil product conveying pipeline which takes a production device as a center and comprises a system pipe network area. The oil pipe is a related pipeline for oil conveying of an oil pump: consists of an inlet pipeline and an outlet pipeline of an oil pump. During normal production, the oil pump is constantly delivering oil, so the oil in such oil pipes is in constant flow.

The second type: and an oil product conveying pipeline is interrupted. The oil pipelines comprise pipelines used in an oil storage tank area of a refinery and production device start-stop pipelines.

In the third category: and a pressure guide pipe. The length of the pipeline is only 3-5 m, and the medium in the pipeline is in a non-flowing state. The flow and pressure measuring instrument of the first kind of oil pipe of the pressure guide pipe is connected with the pressure guide pipe, and the pressure guide pipe is used as a pressure signal pipe for transmitting pressure signals to the instrument. The medium in the pressure guide pipe is steam condensate or oil product.

Of these three types of piping, the first three left-hand, most often run in the amount of about 80% of the total refinery. The second group is less.

The utility model discloses a special accident of defeated oil pipe way accompanies heat steam and prevents congealing automatic control device, the content as follows: for dealing with and handling the refinery accident, prevent the pipeline congealing, this patent uses apparatus for producing as basic unit, and the structure standardization is reformed transform to each apparatus for producing of refinery's companion's heat steam implementation:

first and second heat tracing flow

1. Each device is provided with a special heat tracing steam pipe network:

the heat tracing steam pipe of the first type pipeline and the third type pipeline is reformed together. And the heat tracing pipe network is strictly separated from the second type of pipeline heat tracing pipe network, and the second type of pipeline heat tracing still keeps the original condition before the patent is implemented.

2. The first and third oil delivery pipes are modified by heat tracing steam:

the production device is taken as a basic unit, and each set of production device is provided with a special heat tracing main steam line for heat tracing of the first and third pipeline pipes. A plurality of heat tracing branch lines (the number of the branch lines is equal to that of the oil pumps) are separated from the heat tracing main steam pipe line, each branch line is in port alignment with one oil pump, and a control valve is arranged on each branch line. 2-4 steam small branch lines are separated from the pipeline behind the valve and are respectively led to an inlet pipe and an outlet pipe of the pump (2-3 small branch lines are arranged at the outlet pipe of the double-loop oil pump) to implement oil pipeline heat tracing. In addition, when the small branch heat tracing pipe passes through the oil pipe meter, another small branch pipe is led out to provide heat tracing for the pressure guiding pipe of the meter. Therefore, the on and off of the heat tracing steam of an oil pipeline and a pressure guide pipe which an oil pump belongs to is controlled by the branch line control valve. And (4) transforming the heat tracing steam pipe network for all production devices of the refinery according to the same mode.

3. And (3) transforming a heat tracing pipe network of a second type oil pipeline:

and another special heat tracing main steam line is installed on one production device and is used for heat tracing of the second type of oil pipeline. The heat tracing flow and the process are the same as those before the patent is implemented. Because the second type of oil pipeline (accounting for about 10 percent of the total amount of the oil pipeline) is in an intermittent use state for a long time and is used only during the abnormal production period of the device, the heat tracing steam is continuously opened throughout the year.

4. External heat taking transformation of pressure guide pipe

Compared with the length of an oil pipe, the length of the pressure guide pipe is only 3-6 meters. It is a small pipeline which is connected with oil pipeline, steam pipe or oil refining equipment in the equipment and is responsible for transmitting pressure signal of equipment. If the medium in the connected equipment is oil, the medium in the pressure guide pipe is oil, and similarly, if the medium in the connected equipment is steam, the medium in the pressure guide pipe is water. Because the medium in the pipe does not flow, the heat loss factor of the pipeline, if the heat tracing is not adopted, the oil pressure guide pipe can be frozen when the temperature is lower. The temperature further drops, and when the temperature is lower than zero, the steam pressure pipe can be frozen. In order to prevent congealing, the utility model discloses a pressure pipe puts congeals technique. The heat dissipation loss of the pressure guide pipe after heat preservation is about 40Kcal/mh after about Dg10-15 passes through the pressure guide pipe. And the surface temperature of the steam or oil pipeline (hereinafter referred to as main pipe) connected with the steam or oil pipeline is about 150 ℃ and 400 ℃. The utility model discloses a device for heat extraction from a main pipe and for condensation prevention of a pressure guide pipe, wherein a half-moon-shaped water jacket is arranged on the outer wall of the main pipe, and an O-shaped circulating hot water pipe is connected with the half-moon-shaped water jacket. The circulating pipe and the pressure guide pipe are tightly bundled together and externally insulated. Thus, the water stored in the heat-radiating water jacket on the surface of the main pipe increases the temperature, and the specific gravity of the hot water on the water jacket side decreases. The other side has a larger specific gravity due to lower water temperature (heat energy is transmitted to the pressure guide pipe to compensate heat preservation and radiation loss), and water in the pipe 0 continuously flows due to the specific gravity difference of the two sides, so that the heat energy on the surface of the main pipe is transmitted to the water jacket, the heat energy of the water jacket is transmitted to the O-shaped circulating pipe, the O-shaped pipe transmits the heat energy to the pressure guide pipe, the heat tracing and heat preservation are realized, and the anti-freezing and anti-condensation functions of the pressure guide pipe are realized. In addition, for the oil pipe gauge, an oil pipe accident heat tracing steam branch line is also arranged on a pressure guide pipe of the oil pipe gauge, and the oil pipe does not have heat energy to be externally supplied to the pressure guide pipe in case of an accident. The steam system does not have the accident of shutdown, so the water pressure guide pipe does not need the accident heat tracing steam.

Secondly, setting a special instrument control system of the heat tracing steam:

before the patent is implemented, the switch of the heat tracing steam pipe valve is operated manually. After the patent is implemented, in order to save heat tracing steam, the valves of the first and third oil delivery pipes are stopped to save steam during normal production, and the valves of the heat tracing pipes are opened to prevent freezing and condensation during abnormal production, and the valves of the oil delivery pipes are stopped again after normal production is recovered. In the face of such complex pipe network and frequent switching operation of the refinery, it is obviously impossible to adopt manual operation. Therefore, a meter control and computer management system must be employed. Therefore, the utility model discloses a companion's heat steam instrument interlocking control system: the opening and closing operations of the first and third oil delivery pipes are interlocked with the flow meter of the oil pump to realize the automatic control of the opening and closing. One control valve is interlocked with the flow meter of one oil pump. During normal production, the heat tracing steam control valve is completely closed, and is opened only in case of accident. The linkage setting content is that when the pump flow indicated value shows "normal", the control valve of the contra-orifice is in a closed state, when the pump flow indicated value shows "0-50%", the control valve of the contra-orifice is opened, and the heat tracing steam pipe is put into operation to the oil pipeline and the pressure guide pipe for tracing heat. In addition, the control system is also incorporated into the original computer automatic control system in the production device.

Thirdly, production operation:

in the instrument interlocking automatic control system for delivering the heat tracing steam before the production device is started, all the heat tracing steam branch control valves are automatically opened, and the oil pipe and the pressure guide pipe (excluding the steam pressure guide pipe) are delivered with the heat tracing steam. Once the production device is switched to normal production, and the indicated value of the flow of the oil pump shows 'normal', the computer instrument interlocking automatic control system can automatically turn off the heat tracing steam valve, thereby achieving the purpose of saving heat steam. As long as the oil pump normally operates, the oil in the oil pipe is in a flowing state, the oil pipe cannot be frozen, and the production safety can be ensured. When the production device breaks down: if a certain part of the device has production faults, if one product pump is stopped and the flow of the pump is displayed to be zero, the interlocking of the instrument control system can act, the heat tracing steam branch control valve of the pump is automatically opened, the heat tracing steam is put into operation to respectively perform heat tracing on an inlet oil pipe, an outlet oil pipe, an oil conduit and the like of the pump, and the oil in the pipes is prevented from freezing. If the device has a large production fault, when the whole workshop is about to stop production, the device can cut off feeding, the raw material pump stops running, the raw material flow rate is displayed and returns to zero, the interlocking of the instrument control system of the raw material pump can act, the control valve on each heat tracing steam branch line of each oil pump in the whole workshop is automatically opened, the heat tracing steam is completely put into operation, and the heat tracing is respectively carried out on the related pipeline and the oil guide pipe of each pump. When the fault processing of the production device is finished, the production is recovered to be normal, and the related raw material pump and the related product pump are recovered to be normal in operation, the flow rates of the raw materials and the products can be recovered to be normal, the chain can act, all control valves on the heat tracing steam branch line are automatically closed, the heat tracing steam is switched on and off, and the purpose of saving the heat tracing steam is achieved. Because the on-off of the heat tracing steam in operation is automatically operated by a computer, the operation is accurate, the safe production is ensured, and the labor is saved.

Benefit of implementation and investment recovery period

Benefits of

With the continuous improvement of the technological level of refineries, the probability of production failure is extremely low, and most refineries have no production accidents within the operation period of 3-5 years. Even if accidents happen occasionally in individual refineries, the accidents happen in local places of individual production workshops, and the time is short. The amount of the heat tracing steam for the accident administration is negligible compared with the saved steam amount. Therefore, the economic benefit generated by the patent can be calculated according to the heat tracing steam quantity of all production devices and system pipe networks of the refinery during normal production. Compared with the heat tracing steam consumption of an oil pipeline and a pressure guide pipe before modification, the steam consumption can be saved by 30-50t/h by estimating each refinery. The value of the low-pressure steam of 1.0MPa is about 150-200 yuan/ton. According to the minimum price of 150 yuan/ton, the implementation of the technology can bring 4000-6500 ten thousand yuan/year benefits to each refinery. There are 200 refineries in about 200 size nationwide, and the benefit of this patented technology is estimated to be about 100 billion dollars per year by 200 refineries.

Second, investment recovery period

By implementing the technology, only the steam pipeline, the heat tracing steam line of the oil pipe and the oil pressure guide pipe in the production device and the system pipe network area, the heat preservation of the pipeline and the related instrument control system are modified, the investment of each production device is about 100 ten thousand yuan, and the total investment of a medium refinery is about 2000-3000 ten thousand yuan. The cost is only 30-50% of the cost of the heat tracing steam before the patent is implemented, so the investment recovery period is very short and is only half a year.

The foregoing is only a preferred embodiment of the present invention, and it should be noted that, for those skilled in the art, a plurality of improvements and decorations can be made without departing from the technical principle of the present invention, and these improvements and decorations should also be regarded as the protection scope of the present invention.

Claims

1. The utility model provides an oil refinery oil pipe way accident prevents congealing automatic control device of heat tracing steam, wherein the oil pipe way includes the entry oil pipe and the pump export pipeline of oil pump, and entry oil pipe is connected with the oil outlet of refining equipment, and pump export pipeline divides two the tunnel: go the same way through second flowmeter, first oil pipe return-back equipment, another way, through first flowmeter, product play device pipeline, carry oil product to produce workshop, via system pipe network district, reentrant oil tank district pipeline, divide two ways to go different oil tank internal storage, its characterized in that: the automatic control device comprises a production workshop heat tracing control device, a single oil pump heat tracing control device and an instrument pressure guide pipe heat tracing condensation preventing device, wherein the production workshop heat tracing control device comprises a special heat tracing steam main pipeline and a first locking automatic controller between the flow of a raw material pump and the opening and closing of a plurality of heat tracing steam valves, a plurality of steam heat tracing branch pipes are led out from the steam main pipeline, each steam heat tracing branch pipe is provided with a control valve, the first locking automatic controller is connected with each control valve through a signal line and controls the opening and closing of the control valves through the flow change of an outlet flow meter of the raw material pump, when the production workshop has large accident stop, the raw material pump stops running, the outlet flow meter display value of the raw material pump drops to zero, the first locking controller automatically sends an instruction to the control valves on the heat tracing branch pipes, the control valves are opened, and the steam heat tracing branch pipes corresponding to the raw material pump open the oil inlet pipe and the raw material outlet pipe of the raw material pump for heat tracing, meanwhile, other steam heat tracing branch pipes are opened to perform heat tracing on pipelines at the inlet and the outlet of other oil pumps, when workshop production is recovered to be normal and the display value of an outlet flowmeter is normal, the first linkage automatic controller sends out an instruction, and the control valve closes the heat tracing;

the single oil pump heat tracing control comprises a steam branch line led out from a steam main pipe, and the steam branch line is divided into three paths after flowing out through a second interlocking automatic control valve: the first path gives the oil pipe of the product discharging device to accompany heat to the pipeline of the oil tank area through a first steam pipeline, and the heat-tracing condensation hot water is discharged through a first steam trap; the second path of heat tracing firstly carries out heat tracing on the pump outlet pipeline through a second steam pipeline, then carries out heat tracing on the first oil pipe, and enters a second steam trap downwards at the oil refining equipment; the third path of heat tracing steam enters the inlet oil pipe for tracing heat through a first heat tracing steam pipe and a steam valve through a third steam pipeline, enters the third steam trap at the inlet of the oil pump, and is closed by the interlocking automatic control valve and closed by the three paths of heat tracing when the production is normal; when the oil pump stops running due to an accident and the flow of an oil pump flow meter is lower than a set value, the second interlocking automatic control valve is opened, and the three paths of heat tracing are opened for heat tracing;

the instrument pressure pipe heat tracing condensation preventing device comprises a water jacket and a circulating water pipe connected with the water jacket, wherein the water jacket and the circulating water pipe are filled with water, the water jacket is tightly attached to the main pipeline and is positioned on one side of an instrument, the circulating water pipe is bound with the pressure pipe used for transmitting an instrument pressure signal, and heat in the main pipeline is transferred to the circulating water in the circulating water pipe through the water jacket to perform heat tracing on the pressure pipe.

2. The automatic control device according to claim 1, characterized in that: the number of the steam heat tracing branch pipes led out from the steam main pipeline is the same as that of the oil pumps, and each steam heat tracing branch pipe corresponds to one oil pump.

3. The automatic control device according to claim 1, characterized in that: the set value of the outlet flow meter of the raw material pump is 0-50% of the normal flow, and the set value of the flow meter of the oil pump is 0-50% of the normal flow.

4. The automatic control device according to claim 1, characterized in that: the product in the single oil pump heat tracing control is discharged from an oil loading pipe and a first oil pipe, a first flow meter, an oil pump outlet flow meter and a second flow meter are respectively installed on the first oil pipe, a first steam pipeline and a second steam pipeline are respectively provided with a branch pipe of the heat tracing of a pressure guide pipe of the first flow meter, an oil supply pump flow meter and the second flow meter, and when the first interlocking automatic controller is opened, the three branch pipes with heat tracing are simultaneously opened with heat tracing.

5. The automatic control device according to claim 4, characterized in that: and the three heat tracing branch pipes flow through the pressure guide pipe and then enter the fourth steam trap downwards.

6. The automatic control device according to claim 1, characterized in that: the water jacket is an annular water jacket with a half-moon-shaped section, the inner diameter of the water jacket is the same as the outer diameter of the main pipeline, the water jacket is sleeved on the main pipeline, the inner wall of the water jacket is tightly attached to the outer surface of the main pipeline, and a tightly attached heat transfer contact surface is formed between the inner wall of the water jacket and the outer wall of the main pipeline.

7. The automatic control device according to claim 6, characterized in that: and a heat-insulating layer is additionally arranged outside the water jacket, two ends of the circulating water pipe are respectively connected with two sides of the water jacket to form an O-shaped circulating water pipe, and the heat-insulating layer is arranged outside the water pipe.

8. The automatic control device according to claim 1, characterized in that: the instrument is a flowmeter or a pressure gauge, the pipeline is an oil pipeline or a steam pipe, and the instrument is connected with the pressure transmitter through a pressure guide pipe.