Steam system of acrylic acid device

Abstract

The utility model belongs to the technical field of steam utilization systems, and particularly relates to a steam system of an acrylic acid device. The steam system of the acrylic acid device comprises a thermoelectric device and the acrylic acid device, the thermoelectric device comprises a 10 # desuperheating pressure reducer, an 8 # desuperheating pressure reducer, a 9 # desuperheating pressure reducer and a 1 # desuperheating pressure reducer, and the acrylic acid device comprises a 7 # desuperheating pressure reducer. The 10 # temperature and pressure reducer is connected with the 9 # temperature and pressure reducer through a 9 # steam pipeline, two pipelines are led out of the 9 # temperature and pressure reducer, one pipeline is connected with a pipeline in the acrylic acid device through a standby pipeline, and the other pipeline is connected with a pipeline led out of the 8 # temperature and pressure reducer. According to the steam system of the acrylic acid device, the thermoelectric device is connected with the acrylic acid device through the two main pipelines, the steam temperature is increased, the temperature and superheat degree of turbine steam are facilitated, and energy conservation and consumption reduction are achieved.

Description

Technical Field

[0001] The utility model belongs to the technical field of steam utilization systems, and in particular relates to a steam system of an acrylic acid device. Background Art

[0002] Acrylic acid is a colorless liquid with a pungent odor. Its chemical formula is C3H4O2. It is the simplest unsaturated carboxylic acid, consisting of a vinyl group and a carboxyl group. Acrylic acid is miscible with water, alcohol, ether and chloroform. It has active chemical properties and is easily polymerized in the air. Acrylic acid is prepared from propylene and is mainly used to prepare acrylic resin. Acrylic acid and its derivatives can be homopolymerized or copolymerized, and the resulting polymers are widely used in synthetic resins, synthetic fibers, highly absorbent resins, building materials, coatings and other industrial sectors.

[0003] The process flow of acrylic acid unit mainly includes: hydrogen and vinyl chloride are input into the reaction unit, and raw materials are input into the reactor in the reactor to carry out polymerization reaction. The reactor adopts a continuous flow mode and realizes the reaction by controlling temperature and pressure. The reaction products are separated in the separation unit to obtain the target product acrylic acid. The separation unit adopts distillation and extraction technologies and adjusts the operating parameters to achieve the separation and purification of acrylic acid. The separated acrylic acid is further refined through distillation, homogenization and drying process operations, packaging and storage.

[0004] At present, acrylic acid units use steam grades of 2.0MPa, 1.5MPa, 0.2MPa, etc. according to different units and equipment. Among them, 2.0MPa steam is mainly used for system heating and supplementary steam for turbines to ensure the stability of the superheat and pressure of the steam entering the turbine. 1.5MPa steam is mainly used for reactor temperature adjustment, steam jet pumps, etc. 1.5MPa steam is mainly used for reactor temperature adjustment, steam jet pumps, etc. There is little difference between the pressure grades and supply temperatures of 2.0MPa and 1.5MPa steam. The existing four main pipelines enter the acrylic acid unit from the hot spot unit, passing through the 7# desuperheater, 8# desuperheater, 9# desuperheater, and 1# desuperheater respectively. However, there are many pipelines, a large amount of water drainage, a low steam temperature, and serious waste, which is not conducive to the stable operation of the unit and it is difficult to achieve the superheat used by the acrylic acid unit.

[0005] CN201172642Y discloses an air control system in an acrylic acid production device, in which a thermocouple is arranged on the pipeline before the compressed air enters the pre-mixer, and a temperature transmitter is provided. The temperature transmitter outputs a signal to the DCS system of the device, and the DCS output signal controls the electric heater group of the air preheater, and controls the temperature of the air before entering the pre-mixer to be between 160°C and 170°C, so that the fresh air feed temperature can be controlled within the operating temperature range allowed by the catalyst performance, ensuring the temperature of the mixed gas to be stable and saving the steam consumption of the device. Although this device improves the problem of large temperature difference in four seasons, the problem of steam superheat of the pipeline is not improved, and it cannot be applied to steam systems of different pressure levels of acrylic acid. Utility Model Content

[0006] The technical problem to be solved by the utility model is to overcome the above-mentioned defects in the prior art, provide a steam system for an acrylic acid device, connect the thermoelectric device with the acrylic acid device through two main pipes, increase the steam temperature, which is beneficial to the temperature superheat of turbine steam and save energy and reduce consumption.

[0007] The steam system of the acrylic acid device described in the utility model includes a thermoelectric device and an acrylic acid device. The thermoelectric device includes a 10# desuperheater and pressure reducer, an 8# desuperheater and pressure reducer, and a 1# desuperheater and pressure reducer. The acrylic acid device includes a 7# desuperheater and pressure reducer.

[0008] The 10# desuperheater and pressure reducer are connected to the 8# desuperheater and pressure reducer via a steam pipeline, the 8# desuperheater and pressure reducer are connected to the steam pipeline in the acrylic acid device via a steam pipeline, and a spare pressure reducing valve is arranged on the main steam pipeline in the acrylic acid device, and a 7# desuperheater and pressure reducer is arranged on the bypass pipeline.

[0009] The steam level of 8# steam pipeline and 9# steam pipeline is 2.0MPa. The function of the standby pressure reducing valve is to reduce the pressure of 2.0MPa steam, and the 2.0MPa and 1.5MPa steam use the same temperature.

[0010] Preferably, the 10# desuperheater and pressure reducer is connected to the 1# desuperheater and pressure reducer through the 1# steam pipeline, and the 1# desuperheater and pressure reducer is connected to the pipeline in the acrylic acid device. The steam grade transported by the 1# steam pipeline is 2.0 MPa.

[0011] Further preferably, the 1# steam pipeline is connected to a 1# cooling water pipeline.

[0012] Preferably, a 9# steam pipeline is connected in parallel with the 8# desuperheater and a 9# desuperheater is arranged on the 9# steam pipeline. The 9# desuperheater and desuperheater serves as a backup solution when the main steam pipeline or the desuperheater and desuperheater system of the acrylic acid unit fails.

[0013] Preferably, the 8# steam pipeline is connected to a 8# cooling water pipeline.

[0014] Preferably, the 9# steam pipeline is connected to a 9# cooling water pipeline.

[0015] Preferably, the diameters of the 8# steam pipeline and the 9# steam pipeline are 50 mm.

[0016] Further preferably, the diameter of the 1# steam pipeline is 100 mm.

[0017] The steam system of the acrylic acid device of the utility model is obtained by removing the original 7# temperature reducing and pressure reducing device in the thermoelectric device, and the outlet pipeline of the 8# temperature reducing and pressure reducing device adopts the heating parameters of the original 7# temperature reducing and pressure reducing device outlet pipeline for external supply, which is supplied to the acrylic acid device. A spare pressure reducing valve is added to the steam pipeline in the acrylic acid device and a 7# temperature reducing and pressure reducing device is added to the bypass, which cooperate to convert 2.0MPa steam, and the 2.0MPa steam and 1.5MPa steam use the same temperature.

[0018] Compared with the prior art, the utility model has the following beneficial effects:

[0019] The steam system of the acrylic acid device of the utility model optimizes the two-way steam of 2.0MPa and 1.5MPa, and changes the two steams from the thermoelectric to the acrylic acid device into one, which is controlled at 2.0MPa and 245°C, and the temperature is regulated by the thermoelectric device. The acrylic acid device is newly equipped with a spare pressure reducing valve and a temperature and pressure reducing device, and the 1.5MPa steam is obtained by reducing the pressure of the 2.0MPa steam. The 2.0MPa and 1.5MPa steam use the same temperature, and on the basis of not affecting the original various steam combinations, the drainage of the pipeline is reduced (1t / h), the temperature of the steam is increased, and it is beneficial to maintain a stable temperature superheat (30°C) of the turbine steam. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a schematic diagram of the steam system of the acrylic acid device of the present invention.

[0021] Figure 2 This is a schematic diagram of the steam system of the existing acrylic acid plant of Comparative Example 1.

[0022] In the figure: 1. Thermal power plant; 2. Acrylic acid plant; 3. 10# desuperheater and pressure reducer; 4. 8# steam pipeline; 5. 9# steam pipeline; 6. 1# steam pipeline; 7. 8# desuperheater and pressure reducer; 8. 9# desuperheater and pressure reducer; 9. 1# desuperheater and pressure reducer; 10. Spare pipeline; 11. Spare pressure reducing valve; 12. 7# desuperheater and pressure reducer; 13. 1# desuperheating water pipeline; 14. 9# desuperheating water pipeline; 15. 8# desuperheating water pipeline; 16. 7# steam pipeline. DETAILED DESCRIPTION

[0023] The present invention is further described below in conjunction with specific embodiments. The internal structures of the thermoelectric device 1 and the acrylic acid device 2 described in the present invention are both existing conventional devices, and do not belong to the improvement of the present invention, so they will not be described in detail. As for the sources and origins of the thermoelectric device 1 and the acrylic acid device 2, they all come from the thermoelectric device 1 and go to the inside of the acrylic acid device 2. As for the specific connection structure, it will not be described in detail, and it can be effectively utilized by those skilled in the art according to the reaction characteristics of acrylic acid. Therefore, it will not be discussed in detail, as long as the stable provision of the superheat of the steam pipeline is achieved.

[0024] Example 1

[0025] like Figure 1 As shown, the steam system of the acrylic acid device includes a thermoelectric device 1 and an acrylic acid device 2. The thermoelectric device 1 includes a 10# temperature reducing and pressure reducing device 3, an 8# temperature reducing and pressure reducing device 7, a 9# temperature reducing and pressure reducing device 8, and a 1# temperature reducing and pressure reducing device 9. The acrylic acid device 2 includes a 7# temperature reducing and pressure reducing device 12.

[0026] The 10# desuperheater 3 is connected to the 9# desuperheater 8 through the 9# steam pipeline 5. The outlet pipeline of the 9# desuperheater 8 has two routes, one of which is connected to the pipeline in the acrylic acid device 2 through the spare pipeline 10, and the other is connected to the pipeline leading out of the 8# desuperheater 7. The pipeline where the 9# desuperheater 8 is located serves as a backup solution when the main steam pipeline or the desuperheater system of the acrylic acid device fails.

[0027] The 10# desuperheater and pressure reducer 3 is connected to the 8# desuperheater and pressure reducer 7 through the 8# steam pipeline 4. After the 8# desuperheater and pressure reducer 7 is connected to the pipeline in the acrylic acid device 2, it is divided into three paths. The first path is connected to the pipeline in the acrylic acid device 2 and a spare pressure reducing valve 11 is arranged on the pipeline. The second path is connected to the pipeline in the acrylic acid device 2 connected to the spare pipeline 10. The third path is connected back to the first pipeline through a bypass pipeline and a 7# desuperheater and pressure reducer 12 is arranged on the bypass pipeline. The steam level conveyed by the 8# steam pipeline 4 and the 9# steam pipeline 5 is 2.0MPa. The function of the spare pressure reducing valve 11 is to reduce the pressure of 2.0MPa steam. The 2.0MPa and 1.5MPa steam use the same temperature.

[0028] The 10# desuperheater 3 is connected to the 1# desuperheater 9 through the 1# steam pipeline 6, and the 1# desuperheater 9 is connected to the pipeline in the acrylic acid device 2. The steam grade transported by the 1# steam pipeline 6 is 0.2MPa.

[0029] The 1# steam pipeline 6 is connected to a 1# cooling water pipeline 13 .

[0030] The 8# steam pipeline 4 is connected to the 8# cooling water pipeline 15 .

[0031] The 9# steam pipeline 5 is connected to a 9# cooling water pipeline 14 .

[0032] The diameters of the 8# steam pipeline 4 and the 9# steam pipeline 5 are 50 mm.

[0033] The diameter of the 1# steam pipeline 6 is 100 mm.

[0034] The steam system of the acrylic acid device of the utility model is to remove the original 7# desuperheater and pressure reducer 12 in the thermoelectric device 1, and use the original heating parameters of the 7# desuperheater and pressure reducer 12 lead-out pipeline on the 8# desuperheater and pressure reducer 7 to supply the heat to the acrylic acid device 2, and add a spare pressure reducing valve 11 on the steam pipeline in the acrylic acid device 2 and a 7# desuperheater and pressure reducer 12 on the bypass, which work together to convert the 2.0MPa steam, and the 2.0MPa steam and the 1.5MPa steam use the same temperature. The steam main pipelines connecting the three thermoelectric devices and the acrylic acid device are improved to two.

[0035] Comparative Example 1

[0036] like Figure 2 As shown, the steam system of the existing acrylic acid device includes a thermoelectric device 1 and an acrylic acid device 2. The thermoelectric device 1 includes a 10# desuperheater 3, an 8# desuperheater 7, a 9# desuperheater 8, a 1# desuperheater 9, and a 7# desuperheater 12, while the acrylic acid device 2 does not have a standby pressure reducing valve 11 and a desuperheater on the bypass. The 10# desuperheater 3 is connected to the 7# desuperheater 12 via a 7# steam pipeline 16, and the rest is the same as in Example 1.

[0037] Through the above comparison, after implementation, the 10# desuperheater and pressure reducer 3 is respectively connected with the 7# steam pipeline 16, the 9# steam pipeline 5, the 8# steam pipeline 4, and the 1# steam pipeline 6, and the 1# steam pipeline 6 outputs steam with a steam grade of 1.5MPa.

[0038] In the steam system of the acrylic acid device of the utility model, the 2.0MPa steam is mainly used for system heating and supplementing steam for turbines to ensure the superheat and pressure stability of the steam entering the turbine. The steam system of the acrylic acid device of the utility model is removed by removing the original 7# desuperheater and pressure reducer 12 in the thermoelectric device 1, and the outlet pipeline of the 8# desuperheater and pressure reducer 7 adopts the heating parameters of the original 7# desuperheater and pressure reducer 12 outlet pipeline for external supply, and the external supply is supplied to the acrylic acid device 2, and a spare pressure reducing valve 11 is added to the steam pipeline in the acrylic acid device 2 and a 7# desuperheater and pressure reducer 12 is added to the bypass, which cooperates to convert the 2.0MPa steam, and the 2.0MPa steam and the 1.5MPa steam use the same temperature.

Claims

1. A steam system for an acrylic acid device, characterized in that: It comprises a thermoelectric device (1) and an acrylic acid device (2), wherein the thermoelectric device (1) comprises a 10# temperature reducing and pressure reducing device (3), an 8# temperature reducing and pressure reducing device (7), and a 1# temperature reducing and pressure reducing device (9), and the acrylic acid device (2) comprises a 7# temperature reducing and pressure reducing device (12); The 10# desuperheater (3) is connected to the 8# desuperheater (7) via a steam pipeline, the 8# desuperheater (7) is connected to the steam pipeline in the acrylic acid device (2) via a steam pipeline, and a spare pressure reducing valve (11) is arranged on the main steam pipeline in the acrylic acid device (2), and a 7# desuperheater (12) is arranged on the bypass pipeline.

2. The steam system of the acrylic acid device according to claim 1, characterized in that: The 10# desuperheater (3) is connected to the 1# desuperheater (9) via the 1# steam pipeline (6), and the 1# desuperheater (9) is connected to the pipeline in the acrylic acid device (2).

3. The steam system of the acrylic acid device according to claim 2, characterized in that: The 1# steam pipeline (6) is connected to the 1# cooling water pipeline (13).

4. The steam system of the acrylic acid device according to claim 1, characterized in that: A 9# steam pipeline (5) is arranged in parallel with the 8# temperature reducing and pressure reducing device (7), a 9# temperature reducing and pressure reducing device (8) is arranged on the 9# steam pipeline (5), and the 8# temperature reducing and pressure reducing device (7) is arranged on the 8# steam pipeline (4).

5. The steam system of the acrylic acid device according to claim 4, characterized in that: The 8# steam pipeline (4) is connected to the 8# cooling water pipeline (15).

6. The steam system of the acrylic acid device according to claim 4, characterized in that: The 9# steam pipeline (5) is connected to a 9# cooling water pipeline (14).

7. The steam system of the acrylic acid device according to claim 4, characterized in that: The diameters of the 8# steam pipeline (4) and the 9# steam pipeline (5) are 50 mm.

8. The steam system of the acrylic acid device according to claim 2, characterized in that: The diameter of the 1# steam pipeline (6) is 100 mm.

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