Circulating system of high-pressure steam generator of styrene device

Abstract

The utility model relates to the technical field of steam generators, in particular to a high-pressure steam generator circulating system of a styrene device, which comprises a high-pressure steam generator and a steam pocket. A steam pocket outlet is connected to a high-pressure steam generator inlet through a steam generator inlet pipe group; the steam generator outlet pipe group comprises an outlet header pipe and a plurality of outlet branch pipes, one ends of the outlet branch pipes are connected with the outlet of the high-pressure steam generator, and the other ends are connected with the outlet header pipe; the steam generator inlet pipe set comprises an inlet header pipe and a plurality of inlet branch pipes, one ends of the inlet branch pipes are connected with the high-pressure steam generator outlet, and the other ends of the inlet branch pipes are connected with the inlet header pipe which is connected with an outlet in the bottom of the steam pocket. The inlet header pipe is connected with multiple forced circulation pumps in parallel. Inlet and outlet pipelines of the high-pressure steam generator are adjusted, flow of a circulating pipeline is controlled, erosion corrosion conditions are reduced, and long-period stable operation of the device is guaranteed.

Description

Technical Field

[0001] The utility model belongs to the technical field of steam generators, and in particular relates to a high-pressure steam generator circulation system of a styrene device. Background Art

[0002] The tube side of the high-pressure steam generator of the styrene unit is a mixture of ethylbenzene dehydrogenation reaction materials and steam, and the shell side is high-pressure boiler water. The high-pressure boiler water undergoes thermal siphon circulation in the steam generator. During operation, there is erosion and corrosion, which causes some heat exchange tubes to become thinner and leak. In order to ensure the long-term stable operation of the unit, technical transformation of the new high-pressure steam generator process is required. Summary of the Invention

[0003] In view of the problems existing in the above-mentioned prior art, the purpose of the present invention is to provide a high-pressure steam generator circulation system for a styrene device, which adjusts the circulation flow of the steam generator and reduces the erosion and corrosion of the high-pressure steam generator tube bundle caused by bubbles in the boiler feed water.

[0004] To achieve the above-mentioned purpose, the technical solution adopted by the present invention is as follows: a high-pressure steam generator circulation system for a styrene device, comprising a high-pressure steam generator and a steam drum, wherein the outlet of the high-pressure steam generator is connected to the top inlet of the steam drum through a steam generator outlet pipe group, and the bottom outlet of the steam drum is connected to the inlet of the high-pressure steam generator through a steam generator inlet pipe group; the steam generator outlet pipe group comprises an outlet main pipe and a plurality of outlet branch pipes, one end of each of the outlet branch pipes is respectively connected to the outlet of the high-pressure steam generator, the other end of each of the outlet branch pipes is connected to the outlet main pipe, and the other end of the outlet main pipe is connected to the top inlet of the steam drum; the steam generator inlet pipe group comprises an inlet main pipe and a plurality of inlet branch pipes, one end of each of the inlet branch pipes is respectively connected to the outlet of the high-pressure steam generator, the other end of each of the inlet branch pipes is connected to the inlet main pipe, and the other end of the inlet main pipe is connected to the outlet at the bottom of the steam drum; the inlet main pipe is connected in parallel with a plurality of forced circulation pumps.

[0005] Furthermore, there are six outlet branch pipes, which are respectively connected to six outlet interfaces of the high-pressure steam generator.

[0006] Furthermore, the outlet main pipe includes a first outlet main pipe and a second outlet main pipe, the first outlet main pipe and the second outlet main pipe are respectively connected to the two inlet interfaces of the steam drum, the first outlet main pipe is connected to four outlet branches, and the second outlet main pipe is connected to two outlet branches.

[0007] Furthermore, the first outlet main pipe is a DN600 pipeline, the second outlet main pipe is a DN400 pipeline, and the six outlet branch pipes are all DN350 pipelines.

[0008] Furthermore, the flow rate of the first outlet main pipe is 399 t / h, and the flow velocity is 19.6 m / s; the flow rate of the second outlet main pipe is 186 t / h, and the flow velocity is 20.6 m / s.

[0009] Furthermore, there are two inlet branch pipes, which are respectively connected to two inlet interfaces of the high-pressure steam generator, and the two inlet branch pipes are connected to the inlet main pipe.

[0010] Furthermore, the inlet main pipe is a DN500 pipeline, and the two inlet branches are both DN300 pipelines; the flow rate of the inlet main pipe is 585t / h, and the flow velocity is 1.0m / s.

[0011] Furthermore, three forced circulation pumps are arranged in parallel on the inlet main pipe, and two of the three forced circulation pumps are in operation and one is in standby, or all of them are in operation.

[0012] Furthermore, a crossing pipeline crossing the forced circulation pump is provided on the inlet main pipe, both ends of the crossing pipeline are connected to the inlet main pipe, and a control valve and a check valve are provided on the crossing pipeline.

[0013] Furthermore, each of the forced circulation pumps is connected to the inlet main pipe through a pump inlet pipe and a pump outlet pipe, both of which are DN300 pipelines. A pump inlet valve is provided on the pump inlet pipe, and a check valve and a pump outlet valve are provided on the pump outlet pipe.

[0014] Furthermore, a flow meter is provided on the inlet main pipe.

[0015] The beneficial effects of the utility model are: by adjusting the number and diameter of the inlet and outlet pipes of the high-pressure steam generator, the circulation flow of the circulation pipe is controlled, the erosion and corrosion of the high-pressure steam generator during operation is reduced, and the long-term stable operation of the device is ensured. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 This is a flow chart of the high-pressure steam generator circulation system of the styrene device of the present utility model;

[0017] In the figure: 1. High-pressure steam generator, 2. Steam drum;

[0018] 3. Steam generator outlet pipe group, 301, first outlet main pipe, 302, second outlet main pipe, 303 outlet branch pipe;

[0019] 4. Steam generator inlet pipe group, 401, inlet main pipe, 402, inlet branch pipe;

[0020] 5. Forced circulation pump, 6. Pump inlet pipe, 7. Pump outlet pipe, 8. Pump inlet valve, 9. Check valve, 10. Pump outlet valve, 11. Flow meter, 12. Crossover pipeline, 13. Control valve. DETAILED DESCRIPTION

[0021] To make the above-mentioned objects, features, and advantages of the present invention more clearly understood, the following detailed description of specific embodiments of the present invention is provided in conjunction with the accompanying drawings. The following description sets forth many specific details to facilitate a full understanding of the present invention. However, the present invention can be implemented in many other ways than those described herein, and those skilled in the art may make similar modifications without departing from the scope of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below.

[0022] See attached Figure 1 A high-pressure steam generator circulation system for a styrene device comprises a high-pressure steam generator 1 and a steam drum 2, wherein the outlet of the high-pressure steam generator 1 is connected to the inlet at the top of the steam drum 2 through a steam generator outlet pipe group 3, and the outlet at the bottom of the steam drum 2 is connected to the inlet of the high-pressure steam generator 1 through a steam generator inlet pipe group 4; the steam generator outlet pipe group 3 comprises a first outlet main pipe 301, a second outlet main pipe 302 and six outlet branch pipes 303, one end of the six outlet branch pipes 303 is respectively connected to the six outlet interfaces of the high-pressure steam generator 1, wherein the other ends of four outlet branch pipes are connected to the first outlet The main pipe 301 is connected, and the other ends of the remaining two outlet branches are connected to the second outlet main pipe 302. The first outlet main pipe 301 and the second outlet main pipe 302 are respectively connected to the two inlet interfaces on the top of the steam drum 2; the steam generator inlet pipe group 4 includes an inlet main pipe 401 and two inlet branches 402, one end of the two inlet branches 402 is respectively connected to the inlet interface of the high-pressure steam generator 1, and the other ends of the two inlet branches 402 are connected to the inlet main pipe 401, and the other end of the inlet main pipe 401 is connected to the outlet interface at the bottom of the steam drum 2; the inlet main pipe 401 is connected in parallel with three groups of forced circulation pumps 5.

[0023] Furthermore, under normal conditions, two of the three forced circulation pumps 5 are in operation and one is in standby mode. The rated flow rate of each forced circulation pump is 308 t / h, and the head of the forced circulation pump is H=25 m.

[0024] Furthermore, a crossover line 12 is provided on the inlet manifold 401, spanning the forced circulation pump 5. Both ends of the crossover line 12 are connected to the inlet manifold 401. A control valve 13 and a check valve 9 are provided on the crossover line 12. If the pump suddenly stops operating, the crossover line 12 can partially restore the original thermosiphon operation, preventing the steam drum 2 from drying out.

[0025] Furthermore, the first outlet main pipe 301 is a DN600 pipeline, the second outlet main pipe 302 is a DN400 pipeline, and the six outlet branch pipes 303 are all DN350 pipelines.

[0026] Furthermore, the flow rate of the first outlet main pipe 301 is 399 t / h, and the flow velocity is 19.6 m / s; the flow rate of the second outlet main pipe 302 is 186 t / h, and the flow velocity is 20.6 m / s.

[0027] Furthermore, the inlet main pipe 401 is a DN500 pipeline, and the two inlet branches 402 are both DN300 pipelines; the flow rate of the inlet main pipe 401 is 585t / h, and the flow velocity is 1.0m / s.

[0028] Furthermore, each of the forced circulation pumps 5 is connected to the inlet manifold 401 through a pump inlet pipe 6 and a pump outlet pipe 7, both of which are DN300 pipelines. A pump inlet valve 8 is provided on the pump inlet pipe 6, and a check valve 9 and a pump outlet valve 10 are provided on the pump outlet pipe 7.

[0029] Furthermore, a flow meter 11 is provided on the inlet manifold 401 for flow detection.

[0030] The high-pressure steam generator (HSG) tube side of the styrene unit contains a mixture of ethylbenzene dehydrogenation reaction materials and condensate, while the shell side contains 3.8MPa high-pressure boiler water. The original process flow had one water inlet and two water outlets. Water was thermosyphoned between the drum and the HSG, with a circulation rate of 195 t / h. To avoid tube bundle corrosion, this embodiment converts the number of outlets from the HSG to the drum from two to six, the inlet from one to two, and adds three forced circulation pumps to the HSG inlet pipeline. The goal is to increase the HSG circulation ratio from the original 5:1 to 15:1, and the circulation rate from 195 t / h to 585 t / h. Through technical improvements, the erosion and corrosion of the HSG tube bundle by bubbles in the boiler feedwater is reduced, ensuring long-term stable operation of the unit.

[0031] To ensure the circulation flow, the six outlet branches are connected to the two outlet mains respectively. While the original two outlets remain unchanged, a new inlet interface is added to the top of the steam drum to connect to the first outlet main, and the first outlet main is connected to the newly added four outlet branches.

[0032] It should be noted that the parts not described in detail in the present invention are prior art.

[0033] The terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of the technical features being referred to. Therefore, a feature specified as "first" or "second" may explicitly or implicitly include at least one such feature. In the description of this utility model, "plurality" means at least two, for example, two, three, etc., unless otherwise specifically defined.

[0034] It should be noted that when an element is referred to as being "fixed to" or "disposed on" another element, it may be directly on the other element or there may be an intermediate element. When an element is considered to be "connected to" another element, it may be directly connected to the other element or there may be an intermediate element. The terms "vertical," "horizontal," "upper," "lower," "left," "right," and similar expressions used herein are for illustrative purposes only and do not represent the only implementation methods.

[0035] The above examples are merely preferred embodiments of the present invention. Obviously, the present invention is not limited to the above examples and is subject to numerous variations. Any variations that can be directly derived or conceived by a person skilled in the art from the disclosure of the present invention should be considered within the scope of protection of the present invention.

Claims

1. A high-pressure steam generator circulation system for a styrene device, characterized by: It includes a high-pressure steam generator and a steam drum, the outlet of the high-pressure steam generator is connected to the inlet at the top of the steam drum through a steam generator outlet pipe group, and the outlet at the bottom of the steam drum is connected to the inlet of the high-pressure steam generator through a steam generator inlet pipe group; the steam generator outlet pipe group includes an outlet main pipe and several outlet branch pipes, one end of several outlet branch pipes are respectively connected to the outlet of the high-pressure steam generator, the other ends of several outlet branch pipes are connected to the outlet main pipe, and the other end of the outlet main pipe is connected to the inlet at the top of the steam drum; the steam generator inlet pipe group includes an inlet main pipe and several inlet branch pipes, one end of several inlet branch pipes are respectively connected to the inlet of the high-pressure steam generator, the other ends of several inlet branch pipes are connected to the inlet main pipe, and the other end of the inlet main pipe is connected to the outlet at the bottom of the steam drum; the inlet main pipe is connected in parallel with several forced circulation pumps.

2. A styrene device high-pressure steam generator circulation system according to claim 1, characterized in that: There are six outlet branch pipes, which are respectively connected to six outlet interfaces of the high-pressure steam generator.

3. A styrene plant high-pressure steam generator circulation system according to claim 2, characterized in that: The outlet main pipe includes a first outlet main pipe and a second outlet main pipe, which are respectively connected to two inlet interfaces of the drum. The first outlet main pipe is connected to four outlet branches, and the second outlet main pipe is connected to two outlet branches.

4. A styrene plant high-pressure steam generator circulation system according to claim 3, characterized in that: The first outlet main pipe is a DN600 pipeline, the second outlet main pipe is a DN400 pipeline, and the six outlet branches are all DN350 pipelines; the flow rate of the first outlet main pipe is 399t / h, and the flow velocity is 19.6m / s; the flow rate of the second outlet main pipe is 186t / h, and the flow velocity is 20.6m / s.

5. A high-pressure steam generator circulation system for a styrene plant according to any one of claims 1 to 4, characterized in that: There are two inlet branch pipes, which are respectively connected to two inlet interfaces of the high-pressure steam generator, and the two inlet branch pipes are connected to the inlet main pipe.

6. A styrene plant high-pressure steam generator circulation system according to claim 5, characterized in that: The inlet main pipe is a DN500 pipeline, and the two inlet branches are both DN300 pipelines; the flow rate of the inlet main pipe is 585t / h and the flow velocity is 1.0m / s.

7. The high-pressure steam generator circulation system of a styrene device according to claim 1, characterized in that: Three forced circulation pumps are arranged in parallel on the inlet main pipe, and two of the three forced circulation pumps are in operation and one is in standby or all of them are in operation.

8. A styrene plant high-pressure steam generator circulation system according to claim 1 or 7, characterized in that: The inlet main pipe is provided with a crossing pipeline crossing the forced circulation pump, both ends of the crossing pipeline are connected to the inlet main pipe, and the crossing pipeline is provided with a control valve and a check valve.

9. A styrene plant high-pressure steam generator circulation system according to claim 1 or 7, characterized in that: Each of the forced circulation pumps is connected to the inlet main pipe through a pump inlet pipe and a pump outlet pipe, both of which are DN300 pipelines. A pump inlet valve is provided on the pump inlet pipe, and a check valve and a pump outlet valve are provided on the pump outlet pipe.

10. The high-pressure steam generator circulation system of a styrene device according to claim 1, characterized in that: A flow meter is provided on the inlet main pipe.

Images