Furnace tube decoking system of heating furnace

Abstract

The utility model discloses a heating furnace tube decoking system which comprises a furnace body, the furnace body comprises a furnace tube and a lining which are arranged in the furnace body, and two ends of the furnace tube are respectively connected with a process medium inlet pipeline and a process medium outlet pipeline. The process medium inlet pipeline and the process medium outlet pipeline are respectively provided with a process medium inlet valve and a process medium outlet valve, and further comprises an external leading furnace tube, a process medium bypass, a decoking inlet pipeline, a decoking outlet pipeline, a decoking inlet bypass and a decoking outlet bypass; according to the decoking system for the furnace tube of the heating furnace, only part of the furnace tube sections which are seriously coked in one tube pass are cut out, and the tube sections which are not seriously coked can still work, so that the heating capacity of the heating furnace is reserved to the maximum extent, and normal work of the heating furnace is not influenced.

Description

Technical Field

[0001] The utility model relates to the technical field of heating furnace coke cleaning, in particular to a heating furnace tube coke cleaning system. Background Art

[0002] In my country's petroleum refining industry, most crude oil is heavy. The heavy oil in the heating furnace tube is prone to coking, overheating, and even creep or permanent deformation, or even breakage during the heating process, causing serious production accidents. In order to avoid accidents, it is often necessary to clean the coking layer in time.

[0003] The heating furnace tube generally contains multiple tube passes. In the traditional online decoking technology, a complete tube pass in the heating furnace is first decoked. After the oil feed of this tube pass is cut off, the complete tube pass is decoked, and then it is put back into use. Then, the other tube passes are cleaned in turn in the same way, and finally the coke layer in the tubes of all tube passes is cleaned. The disadvantage of this decoking method is that a complete tube pass is cut out during the decoking process, that is, the entire tube pass cut out no longer participates in the heat exchange work. However, in practice, the coking of the low-temperature section furnace tube in the entire tube pass is not serious, and it can be left uncut and continue to participate in the heat exchange work. Cutting out the entire tube pass will cause the heating capacity of the heating furnace to drop too much. Summary of the invention

[0004] The technical problem to be solved by the utility model is to overcome the existing defects and provide a heating furnace tube decoking system, which only cuts out a part of the furnace tube section with serious coking in one tube path, and the tube section with less serious coking can continue to work, so as to retain the heating capacity of the heating furnace to the greatest extent, and can effectively solve the problems in the background technology.

[0005] To achieve the above-mentioned purpose, the utility model provides the following technical solutions: a heating furnace tube coke cleaning system, comprising a furnace body, the furnace body comprising a lining and a furnace tube inside thereof, the two ends of the furnace tube being respectively connected to a process medium inlet pipeline and a process medium outlet pipeline, the process medium inlet pipeline and the process medium outlet pipeline being respectively provided with a process medium inlet valve and a process medium outlet valve, characterized in that: it also comprises an external furnace tube, a process medium bypass, a coke cleaning inlet pipeline, a coke cleaning outlet pipeline, a coke cleaning inlet bypass and a coke cleaning outlet bypass;

[0006] The external furnace pipe is located outside the furnace body, and both ends of the external furnace pipe are connected to the furnace pipe located inside the furnace body. A process medium external valve is provided on the external furnace pipe;

[0007] One end of the process medium bypass is connected to the external introduction furnace pipe upstream of the process medium external introduction valve, and the other end of the process medium bypass is connected to the process medium outlet pipeline downstream of the process medium outlet valve;

[0008] The decoking inlet pipeline is provided with a decoking inlet main valve, and the downstream of the decoking inlet pipeline is divided into two branches, one of which is connected to the process medium inlet pipeline downstream of the process medium inlet valve, and the other branch is connected to the external introduction furnace pipe downstream of the process medium external introduction valve;

[0009] One end of the decoking outlet pipeline is connected to the process medium outlet pipeline upstream of the process medium outlet valve, and the decoking outlet pipeline is provided with a first decoking outlet valve and a second decoking outlet valve in sequence;

[0010] One end of the decoking inlet bypass is connected to the decoking inlet pipeline upstream of the decoking inlet main valve, and the other end of the decoking inlet bypass is connected to the decoking outlet pipeline, and the connection point is located between the first decoking outlet valve and the second decoking outlet valve;

[0011] One end of the decoking outlet bypass is connected to the branch pipeline of the decoking inlet pipeline between the decoking inlet pipeline and the external furnace pipe, and the other end of the decoking outlet bypass is connected to the decoking outlet pipeline downstream of the second decoking outlet valve.

[0012] As a preferred technical solution of the present utility model, a process medium bypass valve is provided on the process medium bypass.

[0013] As a preferred technical solution of the utility model, the upstream of the decoking inlet pipeline is connected to two branches respectively provided with a first decoking inlet valve and a second decoking inlet valve.

[0014] As a preferred technical solution of the utility model, a first coke clearing branch valve and a second coke clearing branch valve are respectively arranged on the two downstream branches of the coke clearing inlet pipeline, and the position where the coke clearing outlet bypass connects to the coke clearing inlet pipeline branch is between the first coke clearing branch valve and the second coke clearing branch valve.

[0015] As a preferred technical solution of the utility model, a decoking inlet bypass valve is arranged on the decoking inlet bypass, and a decoking outlet bypass valve is arranged on the decoking outlet bypass.

[0016] As a preferred technical solution of the utility model, the decoking medium introduced into the decoking inlet pipeline can be air, water vapor or a mixture of the two.

[0017] Compared with the prior art, the beneficial effects of the utility model are as follows: the decoking system for the furnace tubes of the heating furnace is connected to the decoking pipeline outside the furnace with the external furnace tube by setting an external furnace tube, so as to realize the purpose of injecting decoking medium into the furnace tubes of the heating furnace; at the same time, during the operation of the heating furnace, as the coke layer of the furnace tube gradually thickens and reaches the decoking standard, the online decoking program is started to decoke the pipe section that is prone to coking. At this time, the pipe section that is not seriously coked and is not included in the online decoking program can still continue to work and heat the oil, thereby retaining the heating capacity of the heating furnace to the greatest extent. For the pipe section that is not seriously coked, because the coking is not serious, decoking can be carried out during the factory maintenance shutdown period. In this way, the heating furnace can be guaranteed to operate without stopping during the entire production cycle and the working efficiency of the heating furnace will not be affected. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 This is a schematic diagram of pipeline connection of the utility model.

[0019] In the figure: 1 furnace body, 2 lining, 3 furnace tube, 4 process medium inlet pipeline, 5 process medium outlet pipeline, 6 process medium inlet valve, 7 process medium outlet valve, 8 external furnace tube, 9 process medium external valve, 10 process medium bypass, 11 process medium bypass valve, 12 coke cleaning inlet pipeline, 13 coke cleaning outlet pipeline, 14 coke cleaning inlet bypass, 15 coke cleaning outlet bypass, 16 first coke cleaning inlet valve, 17 second coke cleaning inlet valve, 18 first coke cleaning outlet valve, 19 second coke cleaning outlet valve, 20 coke cleaning inlet main valve, 21 first coke cleaning branch valve, 22 second coke cleaning branch valve, 23 coke cleaning inlet bypass valve, 24 coke cleaning outlet bypass valve. DETAILED DESCRIPTION

[0020] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments of the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0021] See also Figure 1 , Figure 1The upstream and downstream relationships are determined according to the solid arrows, and the dotted hollow arrows indicate another flow direction of the medium in the pipeline. The utility model provides a technical solution: a heating furnace tube coke cleaning system, comprising a furnace body 1, the furnace body 1 comprising a furnace tube 3 and a lining 2 therein, the two ends of the furnace tube 3 are respectively connected to a process medium inlet pipeline 4 and a process medium outlet pipeline 5, the process medium inlet pipeline 4 and the process medium outlet pipeline 5 are respectively provided with a process medium inlet valve 6 and a process medium outlet valve 7, and also comprising an external furnace tube 8, a process medium bypass 10, a coke cleaning inlet pipeline 12, a coke cleaning outlet pipeline 13, a coke cleaning inlet bypass 14 and a coke cleaning outlet bypass 15;

[0022] Part of the furnace tube 3 in the middle of the furnace body 1 is led to the outside of the furnace body 1 where it is not subjected to flame radiation heat transfer, forming an external introduction furnace tube 8, on which a process medium external introduction valve 9 is provided;

[0023] One end of the process medium bypass 10 is connected to the external introduction furnace pipe 8 upstream of the process medium external introduction valve 9, and the other end of the process medium bypass 10 is connected to the process medium outlet pipeline 5 downstream of the process medium outlet valve 7. The process medium bypass 10 is provided with a process medium bypass valve 11;

[0024] A main coke clearing inlet valve 20 is provided on the coke clearing inlet pipeline 12, and the downstream of the coke clearing inlet pipeline 12 is divided into two branches, one of which is connected to the process medium inlet pipeline 4 downstream of the process medium inlet valve 6, and the other is connected to the external introduction furnace pipe 8 downstream of the process medium external introduction valve 9, and the two branches are respectively provided with a first coke clearing shunt valve 21 and a second coke clearing shunt valve 22, and the position where the coke clearing outlet bypass 15 connects to the branch of the coke clearing inlet pipeline 12 is between the first coke clearing shunt valve 21 and the second coke clearing shunt valve 22, and the upstream of the coke clearing inlet pipeline 12 is connected to two branches with a first coke clearing inlet valve 16 and a second coke clearing inlet valve 17, respectively. In addition, the flow rate of the coke clearing medium can be controlled by adjusting the first coke clearing inlet valve 16 and the second coke clearing inlet valve 17 to adjust the tube wall temperature of the coke clearing furnace tube to prevent the coke clearing furnace tube from overheating;

[0025] One end of the decoking outlet pipeline 13 is connected to the process medium outlet pipeline 5 upstream of the process medium outlet valve 7, and the decoking outlet pipeline 13 is provided with a first decoking outlet valve 18 and a second decoking outlet valve 19 in sequence;

[0026] One end of the coke cleaning inlet bypass 14 is connected to the coke cleaning inlet pipeline 12 upstream of the coke cleaning inlet main valve 20, and the other end of the coke cleaning inlet bypass 14 is connected to the coke cleaning outlet pipeline 13, and the connection point is located between the first coke cleaning outlet valve 18 and the second coke cleaning outlet valve 19, and a coke cleaning inlet bypass valve 23 is provided on the coke cleaning inlet bypass 14;

[0027] One end of the decoking outlet bypass 15 is connected to the branch pipeline of the decoking inlet pipeline 12 between the decoking inlet pipeline 12 and the external furnace pipe 8, and the other end of the decoking outlet bypass 15 is connected to the decoking outlet pipeline 13 downstream of the second decoking outlet valve 19. A decoking outlet bypass valve 24 is provided on the decoking outlet bypass 15.

[0028] By providing the coke cleaning inlet bypass 14 and the coke cleaning outlet bypass 15, the medium in the coke cleaning furnace pipe can flow in both forward and reverse directions, thereby further improving the coke cleaning effect.

[0029] This decoking system is applicable to cylindrical furnaces, vertical furnaces, and box furnaces with single-pass or multi-pass tube passes. The applicable pipelines include vertical pipes, horizontal pipes, or spiral coils.

[0030] (1) The heating furnace is operating normally without coke cleaning:

[0031] At this time, the heating furnace operates normally and there is no coke cleaning work;

[0032] Open the process medium inlet valve 6, the process medium external introduction valve 9, and the process medium outlet valve 7, and close the first coke cleaning inlet valve 16, the second coke cleaning inlet valve 17, the coke cleaning inlet main valve 20, the first coke cleaning branch valve 21, the second coke cleaning branch valve 22, the process medium bypass valve 11, the first coke cleaning outlet valve 18, the second coke cleaning outlet valve 19, the coke cleaning inlet bypass valve 23, and the coke cleaning outlet bypass valve 24;

[0033] At this time, the process medium in the heating furnace is heated by the heating furnace and flows to the downstream through the process medium outlet pipeline 5.

[0034] (2) The heating furnace is operating normally and some furnace tubes are online and decoking in the forward direction:

[0035] At this time, some furnace tubes of the heating furnace are de-coked online in the forward direction, and the furnace tubes that have not been de-coked are still working normally;

[0036] Open the process medium inlet valve 6, the process medium bypass valve 11, the first coke cleaning inlet valve 16, the second coke cleaning inlet valve 17, the coke cleaning inlet main valve 20, the first coke cleaning branch valve 21, the first coke cleaning outlet valve 18, and the second coke cleaning outlet valve 19; close the second coke cleaning branch valve 22, the coke cleaning inlet bypass valve 23, the coke cleaning outlet bypass valve 24, the process medium external introduction valve 9, and the process medium outlet valve 7;

[0037] At this time, the process medium in the heating furnace is heated through the furnace tube 3 with less severe coking, and then passes through the process medium outlet pipeline to the downstream, and the pipeline with severe coking can be introduced into the decoking medium for decoking. The decoking medium can be selected as water vapor or air, and the flow rate of the two can be adjusted by the first decoking inlet valve 16 and the second decoking inlet valve 17 to achieve the most ideal decoking ratio. In addition, the flow rate of the decoking medium can be controlled by adjusting the first decoking inlet valve 16 and the second decoking inlet valve 17 to adjust the tube wall temperature of the decoking furnace tube to prevent the decoking furnace tube from overheating.

[0038] (3) The heating furnace is operating normally, and some furnace tubes are online in reverse decoking condition:

[0039] At this time, some furnace tubes of the heating furnace are reversely decoked online, and the undecoked furnace tubes are still working normally;

[0040] Open the process medium inlet valve 6, the process medium bypass valve 11, the first coke cleaning inlet valve 16, the second coke cleaning inlet valve 17, the coke cleaning inlet bypass valve 23, the coke cleaning outlet bypass valve 24, the first coke cleaning branch valve 21 and the first coke cleaning outlet valve 18, and close the coke cleaning inlet main valve 20, the second coke cleaning outlet valve 19, the process medium outlet valve 7, the process medium external introduction valve 9 and the second coke cleaning branch valve 22;

[0041] At this time, the process medium in the heating furnace is heated through the furnace tube 3 where coking is not serious, and then passes through the process medium outlet pipeline 5 to the downstream. The decoking medium can be introduced into the cut pipeline with serious coking for decoking.

[0042] (4) Heating furnace shutdown and coke cleaning conditions, all furnace tubes forward coke cleaning conditions:

[0043] During the shutdown and maintenance period of the heating furnace, the process medium heating operation is no longer carried out in the heating furnace. At this time, only the decoking operation is carried out, and the decoking medium performs the forward decoking operation on the entire furnace tube system.

[0044] Open the first coke cleaning inlet valve 16, the second coke cleaning inlet valve 17, the coke cleaning inlet main valve 20, the second coke cleaning branch valve 22, the process medium external valve 9, the first coke cleaning outlet valve 18, and the second coke cleaning outlet valve 19; and close the first coke cleaning branch valve 21, the process medium inlet valve 6, the process medium bypass valve 11, the process medium outlet valve 7, the coke cleaning inlet bypass valve 23, and the coke cleaning outlet bypass valve 24.

[0045] (5) Heating furnace shutdown and coke cleaning conditions, all furnace tubes reverse coke cleaning conditions;

[0046] During the shutdown and maintenance period of the heating furnace, the process medium heating operation is no longer carried out in the heating furnace. At this time, only the decoking operation is carried out, and the decoking medium performs reverse decoking operation on the entire furnace tube system.

[0047] Open the first coke cleaning inlet valve 16, the second coke cleaning inlet valve 17, the coke cleaning inlet bypass valve 23, the first coke cleaning outlet valve 18, the process medium external valve 9, the second coke cleaning branch valve 22, and the coke cleaning outlet bypass valve 24; and close the coke cleaning inlet main valve 20, the second coke cleaning outlet valve 19, the process medium outlet valve 7, the first coke cleaning branch valve 21, the process medium bypass valve 11, and the process medium inlet valve 6.

[0048] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A heating furnace tube decoking system, comprising a furnace body (1), wherein the furnace body (1) comprises a lining (2) and a furnace tube (3) therein, wherein two ends of the furnace tube (3) are respectively connected to a process medium inlet pipeline (4) and a process medium outlet pipeline (5), wherein the process medium inlet pipeline (4) and the process medium outlet pipeline (5) are respectively provided with a process medium inlet valve (6) and a process medium outlet valve (7), wherein: It also includes an external furnace pipe (8), a process medium bypass (10), a coke cleaning inlet pipeline (12), a coke cleaning outlet pipeline (13), a coke cleaning inlet bypass (14) and a coke cleaning outlet bypass (15); The external furnace pipe (8) is located outside the furnace body (1), and both ends of the external furnace pipe (8) are connected to the furnace pipe (3) located inside the furnace body (1), and a process medium external valve (9) is provided on the external furnace pipe (8); One end of the process medium bypass (10) is connected to the external introduction furnace pipe (8) upstream of the process medium external introduction valve (9), and the other end of the process medium bypass (10) is connected to the process medium outlet pipeline (5) downstream of the process medium outlet valve (7); The decoking inlet pipeline (12) is provided with a decoking inlet main valve (20), and the downstream of the decoking inlet pipeline (12) is divided into two branches, one of which is connected to the process medium inlet pipeline (4) downstream of the process medium inlet valve (6), and the other branch is connected to the external introduction furnace pipe (8) downstream of the process medium external introduction valve (9); One end of the decoking outlet pipeline (13) is connected to the process medium outlet pipeline (5) upstream of the process medium outlet valve (7), and the decoking outlet pipeline (13) is provided with a first decoking outlet valve (18) and a second decoking outlet valve (19) in sequence; One end of the decoking inlet bypass (14) is connected to the decoking inlet pipeline (12) upstream of the decoking inlet main valve (20), and the other end of the decoking inlet bypass (14) is connected to the decoking outlet pipeline (13), and the connection point is located between the first decoking outlet valve (18) and the second decoking outlet valve (19); One end of the decoking outlet bypass (15) is connected to a branch pipeline of the decoking inlet pipeline (12) between the decoking inlet pipeline (12) and the external furnace pipe (8), and the other end of the decoking outlet bypass (15) is connected to the decoking outlet pipeline (13) downstream of the second decoking outlet valve (19).

2. A heating furnace tube decoking system according to claim 1, characterized in that: The process medium bypass (10) is provided with a process medium bypass valve (11).

3. The heating furnace tube decoking system according to claim 1, characterized in that: The upstream of the decoking inlet pipeline (12) is connected to two branches respectively provided with a first decoking inlet valve (16) and a second decoking inlet valve (17).

4. A heating furnace tube decoking system according to claim 1, characterized in that: A first coke clearing shunt valve (21) and a second coke clearing shunt valve (22) are respectively provided on two downstream branches of the coke clearing inlet pipeline (12), and the position where the coke clearing outlet bypass (15) is connected to the branch of the coke clearing inlet pipeline (12) is between the first coke clearing shunt valve (21) and the second coke clearing shunt valve (22).

5. The heating furnace tube decoking system according to claim 1, characterized in that: The decoking inlet bypass (14) is provided with a decoking inlet bypass valve (23), and the decoking outlet bypass (15) is provided with a decoking outlet bypass valve (24).

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