CN115480476A - Automatic tank cutting method for intermediate tank area based on coal-to-olefin production process - Google Patents

Abstract

The coal-to-olefins production process of the present invention particularly relates to a method for automatically cutting tanks in the tundish tank area based on the coal-to-olefins production process, in which several spherical tanks in the tundish tank area are partitioned according to the difference in receiving or paying materials, and each The spherical tanks in each area are numbered; the receiving valve in front of the emergency shut-off valve at the receiving end of each spherical tank in each area and the feeding valve behind the emergency shut-off valve at the feeding end are electrically connected to the automatic tank cutting system; In each zone, there are main tanks and spare tanks, and the operations of receiving and feeding tanks and feeding tanks are automatically performed according to the liquid level judgment of the servo liquid level gauge; And the detection of the feedback status of the feeding valve and the emergency shut-off valve. If the system detects a fault and cannot meet the feeding and receiving function, it will trigger a human intervention warning for can cutting. The present invention can timely avoid the production fluctuation or even stoppage of upstream and downstream devices caused by human misoperation or valve failure caused by valve closure.

Description

Automatic tank cutting method in tundish tank area based on coal-to-olefins production process

technical field

The invention relates to a coal-to-olefin production process, in particular to an automatic tank cutting method in a tundish tank area based on the coal-to-olefin production process.

Background technique

In the coal-to-olefins production process, the olefin tundish tank area is an important production unit of the olefin department. The tundish tank area includes ethylene spherical tanks, propylene spherical tanks and mixed _C4 spherical tanks, which are respectively responsible for receiving ethylene and propylene produced by the upstream olefin separation device. And the task of mixing C ₄ material, which is transported to downstream polyolefin and OCC/MTBE units after short-term storage in these spherical tanks. Therefore, the intermediate tank area has a special status, arduous tasks, frequent tank cutting, and low fault tolerance rate are its main characteristics.

At present, as shown in Figure 1 of the manual, the existing safety instrument control system of each spherical tank in the intermediate tank area is to set up two emergency shut-off valves at the top and bottom of each group of spherical tanks. The valve position is the position closest to the spherical tank. Once triggered Safety interlock, can achieve complete isolation. The top receiving safety interlock trigger condition comes from three sets of liquid level gauges, which are radar level gauge, servo motor level gauge and high liquid level switch. Once the liquid level of the spherical tank (any two of the three groups) reaches the set The high and high interlock alarm liquid level will interlock and close the top emergency shut-off valve to protect the spherical tank from overfilling and overpressure; the trigger condition of the bottom feeding safety interlock comes from two sets of liquid level gauges, respectively Radar liquid level gauge and servo motor liquid level gauge, once the two sets of liquid level gauges of the spherical tank reach the set low and low interlocking alarm level, the bottom emergency cut-off valve will be interlocked to protect the spherical tank The action of evacuating or stopping a leak. At the same time, all the emergency shut-off valves of the spherical tank are equipped with emergency shut-off switches and buttons on the scene and on the DCS screen. After the interlock condition is confirmed to be eliminated, the valve can only be reset and opened through the SIS system (safety interlock system). Therefore, the normal tank cutting method between each tank group is mainly realized by the receiving valve located in front of the emergency shut-off valve on the top of the spherical tank and the feeding valve located behind the emergency shut-off valve at the bottom of the spherical tank. The existing control method Cans are cut manually through the DCS system.

The intermediate tank area is used as a receiving, storage and transfer unit, especially as a first-level major hazard source. Although the above-mentioned interlocking can play a role in control and protection, as an intermediate material transfer unit, especially the direct supply of 5 sets of polyolefin and A set of OCC/MTBE equipment, lack of consideration in stable control, mainly appears in the similarity of the spherical tank cutting screen, and frequent human-made tank cutting, there are huge errors in tank cutting, which lead to production fluctuations in the receiving device or shutdown accidents due to material outages probability.

Contents of the invention

The present invention aims to solve the technical problems existing in the prior art. For this reason, the present invention provides an automatic tank cutting system and an automatic tank cutting method in the intermediate tank area based on the coal-to-olefins production process.

The technical solution adopted by the present invention to solve its technical problems is:

An automatic tank cutting method for a tundish tank farm based on a coal-to-olefins production process is provided, comprising the following steps:

Step S1, divide the spherical tanks in the tundish tank area according to the difference in receiving or paying materials, and number the spherical tanks in each area in the sequence of 1#, 2#, 3#...n#, n is an even number ;

Step S2, the receiving valve in front of the emergency shut-off valve at the receiving end of each spherical tank in each zone and the feeding valve behind the emergency shut-off valve at the feeding end are electrically connected to the automatic tank cutting system;

Step S3, in each zone, select 1~n/2 spherical tanks as storage tanks, and the rest of the spherical tanks are spare storage tanks, and the storage tanks and spare storage tanks are collected according to step S31 cut cans;

In each zone, 1-n/2 spherical tanks are selected as charging tanks, and the rest of the spherical tanks are spare charging tanks, and the feeding and cutting tanks are carried out according to step S32 between the charging tanks and the spare charging tanks;

Step S31, receiving and cutting tanks: when it is detected that the servo liquid level gauges on m receiving tanks reach the high and high alarm level, control the receiving valves of m spare receiving tanks to open, where m is ≤ n/2 natural number, and close the receiving valve on the corresponding receiving tank at the same time;

Step S32, feeding and cutting tanks: when it is detected that the servo liquid level gauges on the m feeding tanks reach the low and low alarm level, control the feeding valves of the m spare feeding tanks to open, where m is ≤ n/2 natural number, and close the feeding valve on the corresponding feeding tank at the same time;

The automatic can cutting system detects the response status of the receiving valve, the feeding valve and the emergency shut-off valve in real time during the switching period. If the system detects a fault and cannot meet the function of receiving and paying materials, it will trigger a human intervention warning for can cutting .

In a preferred embodiment of the automatic can cutting method in the intermediate tank area based on the coal-to-olefins production process provided by the present invention, the human-computer interaction interface in the automatic can cutting system is provided with a receiving machine for each area. The receiving valve control interface of each spherical tank of the tank and the standby receiving tank and the control interface of the feeding valve of each spherical tank of the receiving tank and the standby receiving tank, the receiving valve control interface and the charging valve control interface The interface is equipped with a reset button and an automatic button.

In a preferred embodiment of the automatic tank cutting method in the intermediate tank area based on the coal-to-olefins production process provided by the present invention, the divisional treatment in the step S1 includes spherical tanks in the ethylene area, spherical tanks in the propylene area, and mixed _C4 Area spherical tank.

In a preferred embodiment of the automatic tank cutting method in the intermediate tank area based on the coal-to-olefins production process provided by the present invention, the spherical tank in the ethylene area and the spherical tank in the propylene area are provided with at least two storage tanks for unqualified materials, Used to receive non-conforming material during shutdown or abnormal conditions.

In a preferred embodiment of the automatic tank cutting method in the tundish tank area based on the coal-to-olefins production process provided by the present invention, the spherical tanks in the ethylene area and the spherical tanks in the propylene area are equipped with 6 to 8 spherical tanks of 2000 m ³ , The hybrid C ₄ zone spherical tank is provided with two 3000m ³ spherical tanks.

Compared with the prior art, the beneficial effect of the automatic can cutting method in the intermediate tank area based on the coal-to-olefins production process provided by the present invention is: the present invention uses the automatic can cutting system to realize automatic can cutting, and can also continuously detect the Using the valve status of the tank, it is possible to avoid in time the production fluctuation or even shutdown of upstream and downstream devices caused by human misoperation or valve failure caused by valve closure.

Description of drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings that need to be used in the description of the embodiments will be briefly introduced below. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, other drawings can also be obtained based on these drawings without creative work, wherein:

Fig. 1 is the arrangement diagram of each spherical tank of the tundish tank area provided by the present invention;

Fig. 2 is the display interface of the human-computer interaction interface in the automatic can cutting system provided by the present invention.

detailed description

The following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only some, not all, embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by persons of ordinary skill in the art without making creative efforts belong to the protection scope of the present invention.

Embodiment one

In the coal-to-olefins production process, the intermediate tank area is responsible for receiving ethylene, propylene and mixed _C4 materials produced by the upstream olefin separation unit, and the materials are transported to the downstream polyolefin and OCC/MTBE unit after being stored in these spherical tanks for a short time. As shown in Figure 1, the intermediate tank area includes ethylene zone spherical tanks, propylene zone spherical tanks and mixed _C4 zone spherical tanks, which are respectively used to undertake the ethylene, propylene and mixed _C4 materials produced by the upstream olefin separation device. The receiving end and the feeding end of the spherical tank in the ethylene area, the spherical tank in the propylene area and the spherical tank in the mixed C ₄ area all realize the emergency switch of the emergency spherical tank through the emergency cut-off valve, so as to protect the spherical tank from being evacuated or prevent leakage. For details, please consider the Background Art of this application.

In order to solve the problem of man-made tank cutting in the production of existing ethylene zone spherical tanks, propylene zone spherical tanks and mixed _C4 zone spherical tanks, as shown in accompanying drawings 1 and 2, this embodiment provides a coal-based An automatic tank cutting method for an intermediate tank area of an olefin production process, comprising the following steps:

Step S1, according to the different receiving or paying materials, several spherical tanks in the tundish tank area are partitioned, specifically divided into ethylene area spherical tanks, propylene area spherical tanks and mixed _C4 area spherical tanks, and the spherical tanks in each area Tanks are numbered in sequence 1#, 2#, 3#...n#, n is an even number;

Step S2, the receiving valve in front of the emergency shut-off valve at the receiving end of each spherical tank in each zone and the feeding valve behind the emergency shut-off valve at the feeding end are electrically connected to the automatic tank cutting system;

Step S3, in each zone, select 1~n/2 spherical tanks as storage tanks, and the rest of the spherical tanks are spare storage tanks, and the storage tanks and spare storage tanks are collected according to step S31 cut cans;

In each zone, 1-n/2 spherical tanks are selected as charging tanks, and the rest of the spherical tanks are spare charging tanks, and the feeding and cutting tanks are carried out according to step S32 between the charging tanks and the spare charging tanks;

Step S31, receiving and cutting tanks: when it is detected that the servo liquid level gauges on m receiving tanks reach the high and high alarm level, control the receiving valves of m spare receiving tanks to open, where m is ≤ n/2 natural number, and close the receiving valve on the corresponding receiving tank at the same time;

Step S32, feeding and cutting tanks: when it is detected that the servo liquid level gauges on the m feeding tanks reach the low and low alarm level, control the feeding valves of the m spare feeding tanks to open, where m is ≤ n/2 natural number, and close the feeding valve on the corresponding feeding tank at the same time;

The automatic can cutting system detects the response status of the receiving valve, the feeding valve and the emergency shut-off valve in real time during the switching period. If the system detects a fault and cannot meet the function of receiving and paying materials, it will trigger a human intervention warning for can cutting , It can timely avoid the production fluctuation or even stoppage of upstream and downstream devices caused by valve closure caused by human misoperation or valve failure.

The human-computer interaction interface in the automatic can cutting system is provided with the receiving valve control interface of each spherical tank of the receiving tank and the standby receiving tank and each of the receiving tank and the standby receiving tank on the human-computer interaction interface. A feeding valve control interface of a spherical tank, the receiving valve control interface and the feeding valve control interface are equipped with a reset button and an automatic button, the reset button is used to switch to manual can cutting, and the automatic button is used to switch to automatic cutting Can.

During the specific embodiment, in this embodiment, the spherical tank in the ethylene zone and the spherical tank in the propylene zone are all set to 8 spherical tanks of 2000m ³ , and the spherical tank in the mixed C ₄ zone is set to 2 spherical tanks of 3000m ³ , wherein the ethylene zone The spherical tank and the propylene area spherical tank are equipped with 2 unqualified material storage tanks, which are used to receive the unqualified material under shutdown or abnormal conditions. Therefore, in the automatic tank cutting system, there are only 6 spherical tanks in the ethylene area and the propylene area. For each spherical tank, the 6 spherical tanks are numbered in the sequence of 1#, 2#, 3#, 4#, 5#, and 6#; the mixed C ₄ zone spherical tank is numbered as 1#, 2#, and the following is ethylene The zone spherical tank is taken as an example to illustrate, the propylene zone spherical tank and the mixed C ₄ zone spherical tank are the same.

During normal production, the intermediate tank area performs automatic can cutting under the control of the automatic can cutting system. The principle of can cutting is as follows:

Automatic tank cutting for material receiving: If the 1# spherical tank is selected as the material receiving tank, any one of the 2#～6# spherical tanks is the spare material receiving tank. According to the operation situation, the liquid level gauge with the highest precision and the highest stability of the current device) judges. When the servo liquid level gauge reaches the high and high alarm level, it will automatically open the backup feeding valve, and wait for the backup receiving valve to fully open. , Automatically close the 1# receiving valve. To cancel automatic tank cutting, click "Reset" on the control interface of the receiving valve to switch to manual valve cutting.

Feeding automatic tank cutting: If the 1# spherical tank is selected as the feeding tank, any one of the 2#～6# spherical tanks is a spare feeding tank, and the system automatically cuts the tank, and the system passes the servo level gauge (from From the perspective of operation, at present, the liquid level gauge with the highest precision and the highest stability of the device) judges. When the servo liquid level gauge reaches the low and low alarm level, it will automatically open the backup feeding valve, and wait for the backup receiving valve to fully open. , Automatically close the 1# feeding valve. To cancel automatic tank cutting, click "Reset" on the control interface of the feeding valve to switch to manual valve cutting.

The automatic can cutting system needs to detect the feedback status of the valve switch during the switching period of automatic material receipt and payment, so as to ensure that the valve has no faults, so as to ensure normal switching. When the receiving and paying function is satisfied, the automatic can cutting cannot be completed if the feedback is not in place or the requirements are not met, and the valve of the main tank (receiving tank or feeding tank) is not closed, and a prompt is triggered to cut the cans for human intervention, thus effectively to avoid hidden dangers. At the same time, the system will also detect and compare the feedback of the receiving valve and feeding valve of the main tank and the emergency cut-off (misoperation of the receiving valve and feeding valve or the shutdown of the emergency shut-off valve due to misoperation, power failure, and line failure), When one of the two feedbacks is not satisfied, the can cutting condition is reached.

The above descriptions are only examples of the present invention, and are not intended to limit the patent scope of the present invention. Any equivalent structure or equivalent process transformation made by using the content of the description of the present invention, or directly or indirectly used in other related technical fields, shall be The same reasoning is included within the scope of patent protection of the present invention.

Claims (5)

1. A method for automatically cutting tanks in a tundish tank area based on a coal-to-olefins production process, characterized in that: comprising the following steps: Step S1, divide the spherical tanks in the tundish tank area according to the difference in receiving or paying materials, and number the spherical tanks in each area in the sequence of 1#, 2#, 3#...n#, n is an even number ; Step S2, the receiving valve in front of the emergency shut-off valve at the receiving end of each spherical tank in each zone and the feeding valve behind the emergency shut-off valve at the feeding end are electrically connected to the automatic tank cutting system; Step S3, in each zone, select 1~n/2 spherical tanks as storage tanks, and the rest of the spherical tanks are spare storage tanks, and the storage tanks and spare storage tanks are collected according to step S31 cut cans; In each zone, 1-n/2 spherical tanks are selected as charging tanks, and the rest of the spherical tanks are spare charging tanks, and the feeding and cutting tanks are carried out according to step S32 between the charging tanks and the spare charging tanks; Step S31, receiving and cutting tanks: when it is detected that the servo liquid level gauges on m receiving tanks reach the high and high alarm level, control the receiving valves of m spare receiving tanks to open, where m is ≤ n/2 natural number, and close the receiving valve on the corresponding receiving tank at the same time; Step S32, feeding and cutting tanks: when it is detected that the servo liquid level gauges on the m feeding tanks reach the low and low alarm level, control the feeding valves of the m spare feeding tanks to open, where m is ≤ n/2 natural number, and close the feeding valve on the corresponding feeding tank at the same time; The automatic can cutting system detects the response status of the receiving valve, the feeding valve and the emergency shut-off valve in real time during the switching period. If the system detects a fault and cannot meet the function of receiving and paying materials, it will trigger a human intervention warning for can cutting . 2. The method for automatically cutting cans in the intermediate tank area based on the coal-to-olefins production process according to claim 1, characterized in that: the human-computer interaction interface in the automatic can cutting system is provided with a receiving material for each area The receiving valve control interface of each spherical tank of the tank and the standby receiving tank and the control interface of the feeding valve of each spherical tank of the receiving tank and the standby receiving tank, the receiving valve control interface and the charging valve control interface The interface is equipped with a reset button and an automatic button. 3. The method for automatically cutting tanks in the intermediate tank area based on the coal-to-olefins production process according to claim 1, characterized in that: the divisional treatment in the step S1 includes spherical tanks in the ethylene area, spherical tanks in the propylene area, and mixed _C4 Area spherical tank. 4. The method for automatically cutting tanks in the tundish tank area based on the coal-to-olefins production process according to claim 3, characterized in that: the spherical tanks in the ethylene area and the spherical tanks in the propylene area are provided with at least two unqualified material storage tanks, Used to receive non-conforming material during shutdown or abnormal conditions. 5. The method for automatically cutting tanks in the tundish tank area based on the coal-to-olefins production process according to claim 3, characterized in that: the spherical tanks in the ethylene area and the spherical tanks in the propylene area are provided with 6 to 8 spherical tanks of 2000 m ³ , The hybrid C ₄ zone spherical tank is provided with two 3000m ³ spherical tanks.

Images