CN213144795U

CN213144795U - Centrifugal compressor for high-pressure hydrocracking unit

Info

Publication number: CN213144795U
Application number: CN202020859725.7U
Authority: CN
Inventors: 孙忠良
Original assignee: Shenyang Site Machinery Manufacturing Co ltd
Current assignee: Shenyang Site Machinery Manufacturing Co ltd
Priority date: 2020-05-21
Filing date: 2020-05-21
Publication date: 2021-05-07
Anticipated expiration: 2030-05-21

Abstract

A centrifugal compressor for a high-pressure hydrocracking unit is characterized in that: the device comprises a rotor set, a stator set, a support bearing, a thrust bearing and a dry gas seal, wherein (1) impellers of the rotor set are in a sequential structure, the number of the impellers is 8, and a high-efficiency ternary backward-bending closed structure is adopted; (2) the shell of the stator group is connected with the left end cover and the right end cover by adopting a snap ring structure; (3) the support bearing adopts a tilting pad bearing; (4) the thrust bearing adopts a Kingsburley structure. It can provide a gas power source with stable pressure and temperature for the production process according to the parameter requirements of the high-pressure hydrocracking process, is particularly suitable for the application of related petrochemical enterprises, and has great economic and social benefits.

Description

Centrifugal compressor for high-pressure hydrocracking unit

Technical Field

The utility model relates to a technical field of high pressure hydrocracking unit in petrochemical can produce the high-quality reforming raw materials that the latent content of aromatic hydrocarbon is high to the centrifugal compressor for the hydrocracking process units of BTX light aromatic hydrocarbon or high-octane number component is further prepared to the maximum.

Background

Hydrocracking is one of the main processes for deep processing of heavy distillate oil, which is not only an important means for producing light oil products in the oil refining industry, but also becomes a key technology of petrochemical enterprises, and plays an irreplaceable role in other processes. Hydrocracking is an important means for mass production of high-quality middle distillate (jet fuel, diesel oil, etc.) and adjustment of oil structure. Moreover, it is the only important means for directly preparing low-sulfur and low-aromatic clean fuel while lightening. Hydrocracking does not need raw material pretreatment, and VGO with high sulfur content can be directly processed. The hydrocracking tail oil can be used as a high-quality feed for preparing ethylene and can also be used as a low-sulfur catalytic cracking raw material. When different catalysts are matched and combined, the method is a key technology for producing high-grade lubricant base stock meeting the API. The clean diesel oil product can be prepared by hydrogenation modification technologies such as aromatic hydrocarbon ring opening and deep desulfurization and dearomatization for secondary conversion oil products such as catalytic cracking diesel oil and coking diesel oil.

Hydrocracking is an improvement of catalytic cracking technology. The catalytic cracking is carried out under the hydrogen condition, so that the dehydrogenation condensation reaction generated during the catalytic cracking can be inhibited, and the generation of coke is avoided. The operating conditions are 6.5-13.5 MPa of pressure and 340-420 ℃, high-grade products without olefin can be obtained, and the liquid yield can reach more than 100% (because hydrogen is added into oil molecules). It is a process in petrochemical industry, i.e. at higher pressure and temperature in the petroleum refining process, the hydrogen gas makes the heavy oil produce hydrogenation, cracking and isomerization reactions under the action of catalyst, and then the heavy oil is converted into light oil (gasoline, kerosene, diesel oil or raw material for preparing olefin by catalytic cracking and cracking). It is different from catalytic cracking in that the catalytic cracking reaction is accompanied by a hydrogenation reaction of hydrocarbons. Hydrocracking is essentially the organic combination of hydrogenation and catalytic cracking processes, and can enable heavy oil products to generate light oil products such as gasoline, kerosene and diesel oil through catalytic cracking reaction.

The hydrocracking device is a main means for processing heavy oil, under the action of catalyst and hydrogen gas the large molecule is cracked into small molecule, the atmospheric residuum can be mostly converted into gasoline, diesel oil fraction and liquefied gas, at the same time the impurities of sulfur and nitrogen can be removed, and it is characterized by that the quality of gasoline and diesel oil product is higher than that of catalytic cracking, and it contains no olefin and the property of the produced oil product is stable.

SUMMERY OF THE UTILITY MODEL

An object of the utility model is to provide a centrifugal compressor suitable for high pressure hydrocracking unit, it can provide the gas power supply of steady pressure and temperature for the production process according to the parameter requirement of high pressure hydrocracking technology.

The utility model provides a centrifugal compressor for hydrocracking unit, its characterized in that: including rotor group, stator group, support bearing, thrust bearing, dry gas seal, wherein:

(1) the rotor set of the compressor comprises a main shaft, an impeller, a spacer bush, a balance disc, a lock nut and a thrust disc. The impeller adopts the structure of arranging in proper order, and the balance disk is installed at the rearmost part of impeller, and impeller and balance disk are installed and are fixed through two lock nuts on the main shaft, constitute the rotor of this compressor jointly with some other little parts. The number of the impellers of the compressor rotor is 8, the impellers adopt efficient ternary backward-bending type closed impellers, the front four impellers on the rotor are identical in structure, and the rear four impellers are identical in structure. The diameter of the impeller is 400-600 mm.

(2) The stator of the compressor includes a casing, end caps, partitions, seals and related components. The shell of the compressor is connected with the left end cover and the right end cover by adopting a snap ring structure, and the structure can meet the strength requirement of high-pressure hydrocracking compressors of various types unlike the traditional vertically split compressor. The partition plate in the stator group of the compressor is an important part forming a gas passage of the compressor, the diffuser of the compressor adopts a vane diffuser, and the vane diffuser can enable gas to smoothly pass through the diffuser, so that the phenomenon that the gas generates turbulence in the diffuser and the efficiency of the compressor is influenced is prevented.

(3) The thrust bearing of the compressor adopts a Kimberley type, and the supporting bearing adopts a tilting-pad bearing.

(4) The shaft end of the compressor is sealed by dry gas at the inlet, so that zero leakage of process gas is ensured when the compressor operates, and safe and stable operation of the compressor is ensured. The multistage impellers with the same diameter are adopted, so that the design and production cost of the compressor is reduced and the production period of equipment is shortened on the premise of realizing the pressure required by the circulating power required by the high-pressure hydrocracking process. The method organically combines theoretical research, practical production and user requirements, and explores a new direction for industrial popularization of research and development results. The front four impellers of the compressor rotor have the same form, the rear four impellers have the same form, the air outlet angles of the blades of the vane diffuser in the stator group are different according to the different angles of the impellers, and the different air outlet angles of the vane diffuser can effectively improve the pneumatic efficiency of the compressor.

The compressor of the utility model is particularly suitable for the technical requirements of the high-pressure hydrocracking process of petrochemical enterprises. All technical parameters of the product are related according to the technological parameters of users, and the product is popular with the users.

Drawings

Fig. 1 is a main sectional view of the compressor in the centrifugal compressor of the present invention, in the figure: stator group 1, rotor group 2, support bearing 3, thrust bearing 4, drive end dry gas seal 5, non-drive end dry gas seal 6.

Fig. 2 is a rotor diagram of the compressor in the centrifugal compressor of the present invention, in which: the main shaft 21, the impeller 22, the impeller 23, the spacer 24, the balance disc 25, the lock nut 26, the thrust disc 27 and the thrust disc lock nut 28.

Fig. 3 is a diagram of the partition plate assembly of the compressor in the centrifugal compressor of the present invention, in which: a diaphragm 11 and diffuser vanes 12.

Fig. 4 is a schematic diagram of a snap ring structure of a compressor in the centrifugal compressor of the present invention, in which: barrel 13, end cover 14, snap ring 15, locking ring 16.

Detailed Description

The following describes in detail a specific embodiment of a centrifugal compressor for a high-pressure hydrocracking apparatus according to the present invention with reference to the drawings.

According to the design parameter requirements, a main shaft 21 of the compressor is machined firstly, and then an impeller 22, an impeller 23, a spacer bush 24, a balance disc 25, a lock nut 26, a thrust disc 27 and a thrust disc lock nut 28 are machined respectively. As shown in fig. 2, four impellers 22 and four impellers 23 are sequentially mounted on the main shaft, a balance disc 25 is mounted behind the last impeller, the impellers and the balance disc are fixed in position by a lock nut 26, and a thrust disc 27 and a thrust disc lock nut 28 are mounted in the position shown in fig. 2, so that a rotor set of the compressor is formed.

The partition 11 and the diffuser vane 12 are machined separately, and as shown in fig. 3, the partition and the diffuser are assembled, and the deflection angle of the vane is different according to different impellers of the diffuser vane 12. The pneumatic efficiency is guaranteed to be increased.

Other parts of the compressor, such as the cylinder 13, the end cap 14, the snap ring 15, and the locking ring 16, are separately machined. In assembling the clamp ring as shown in fig. 4, the compressor head cover 14 is connected to the casing 13 using the clamp ring 15 and the locking ring 16 to achieve fastening. The structure can meet the strength requirements of the end cover and the cylinder body of the high-pressure hydrogenation compressor, and compared with the conventional bolt handle, the safety of the bolt handle is greatly improved.

After each part of the compressor is processed and assembled, the stator group 1, the rotor group 2, the support bearing 3, the thrust bearing 4, the driving end dry gas seal 5 and the non-driving end dry gas seal 6 are assembled together in sequence according to the opposite parts of the main cross section shown in fig. 1, and finally the body of the centrifugal compressor is formed.

The specifications and parameters of the matched compressor are different for high-pressure hydrocracking units with different scales. A few specific examples are to be taken as follows:

example 1

Flow rate of the compressor: 1200000Nm 3/h; inlet pressure: 15.4MPa (A); inlet temperature: 50 ℃; outlet pressure: 18.1MPa (A); rotating speed: n is 5880 rpm; impeller diameter: d is 600 mm.

Example 2

Flow rate of the compressor: 186000Nm 3/h; inlet pressure: 16.698MPa (A); inlet temperature: 56 ℃; outlet pressure: 20.787MPa (A); rotating speed: n is 12138 rpm; impeller diameter: d is 400 mm.

Example 3

Flow rate of the compressor: 400000Nm 3/h; inlet pressure: 11.35MPa (A); inlet temperature: 60 ℃; outlet pressure: 13.9MPa (A); rotating speed: n 11342 rpm; impeller diameter: d-430 mm.

The above three embodiments are only design schemes provided according to different requirements of the whole set of the high-pressure hydrocracking unit process, and the above schemes are embodiments of centrifugal compressors for high-pressure hydrocracking units operated on site for different users, and the present invention is not limited to the above four embodiments. For those skilled in the art, the present invention can be modified and adapted accordingly, and all changes, equivalents, and improvements made without departing from the spirit and principles of the present invention are intended to be embraced therein.

Claims

1. A centrifugal compressor for a high-pressure hydrocracking unit is characterized in that: comprises a rotor set, a stator set, a supporting bearing, a thrust bearing and a dry gas seal, wherein,

(1) the impellers of the rotor set are in a sequential structure, the number of the impellers is 8, and a high-efficiency ternary backward bending type closed structure is adopted;

(2) the shell of the stator group is connected with the left end cover and the right end cover by adopting a snap ring structure;

(3) the support bearing adopts a tilting pad bearing;

(4) the thrust bearing adopts a Kingsburley structure.

2. The centrifugal compressor for a high pressure hydrocracking apparatus as set forth in claim 1, wherein the front four impellers of said rotor are identical in structure, the rear four impellers are identical in structure, and the diameter of the impeller is 400 to 600 mm.