CN113915127A

CN113915127A - Low-temperature screw steam compressor

Info

Publication number: CN113915127A
Application number: CN202111390359.0A
Authority: CN
Inventors: 徐禧磊; 火盈飞; 谭长永; 苏佳楠
Original assignee: Ximo Energy Technology Suzhou Co ltd
Current assignee: Ximo Energy Technology Suzhou Co ltd
Priority date: 2021-11-23
Filing date: 2021-11-23
Publication date: 2022-01-11

Abstract

A low-temperature screw vapor compressor belongs to the technical field of compressors. Including casing, positive rotor, cloudy rotor, cover establish positive rotor gear on the positive rotor, establish the cloudy rotor gear on the cloudy rotor at the cover, positive rotor gear and cloudy rotor gear engagement transmission to drive positive rotor and cloudy rotor and mutually support compressed gas, positive rotor and cloudy rotor mutually support compressed gas's work area be the rotor chamber, one side that the compressor is close to the air inlet is the low pressure side, and one side that is close to the gas vent is the high pressure side, and the characteristics are: both the male and female rotors have bearings and seals disposed on both ends of the low and high pressure sides. The advantages are that: the bearing at the two ends of the rotor is effectively lubricated, the air inlet and the air exhaust are effectively sealed, the system configuration is simplified, and the purchasing and manufacturing cost is reduced.

Description

Low-temperature screw steam compressor

Technical Field

The invention belongs to the technical field of compressors, and particularly relates to a low-temperature screw steam compressor.

Background

Compared with a roots vapor compressor, the screw vapor compressor has the advantages of obvious efficiency advantage in the field of high temperature rise due to the internal compression, and the screw vapor compressor is more and more applied in the field of MVR devices with high temperature rise due to the fact that the internal pressure ratio and the external pressure ratio are close and the noise is small at high speed. The air inlet temperature of a screw vapor compressor for a conventional MVR device is between 80 and 90 ℃, and the air inlet pressure is negative pressure; the exhaust temperature is between 100 ℃ and 110 ℃, the exhaust pressure is micro-positive pressure, and under the working condition, because the bearing bears certain gas force and the steam is transferred to the bearing for certain heat, the heat of the bearing must be taken away by adopting forced lubrication, and oil circuit equipment such as an oil tank, an oil pump, an oil filter, an oil cooler, a pipeline, a valve and the like and necessary instrument control components are configured.

With the stricter environmental protection policy of China, in addition to the high requirements on the wastewater treatment in the industries of large-scale petrochemical industry, textile industry, smelting industry and the like, the cutting fluid in the small machining industry is also subject to strict discharge limitation. Because the cutting fluid is usually not discharged continuously and the processing scale is small, a low-temperature evaporation technology is usually adopted to reduce heat loss and reduce material purchasing requirements. The vapor compressor applied to the low-temperature evaporation technology has the air inlet temperature of 40-50 ℃, the exhaust temperature of 60-70 ℃, and the inlet and the outlet of the vapor compressor are all negative pressure.

Aiming at the lubrication problem of the conventional screw steam compressor, Chinese patent publication No. CN110671326A discloses a screw water vapor compressor unit and a working method, wherein the water vapor compressor unit adopts an oil circuit circulation mode to effectively cool lubricating oil in the compressor and simultaneously avoid the problem of reduction of the lubricating efficiency caused by overhigh temperature of the lubricating oil; reduce the metal debris that lubricating oil carried after using through the coarse oil filter, reduce the damage to the oil pump, filter once more through the essential oil filter simultaneously, reduce the damage to screw compressor. The structure has the following disadvantages in practical use: the system tends to be complex, and the screw steam compressor unit occupies a large area and is high in manufacturing cost when being used for low-temperature steam compression.

Aiming at the problems of sealing and water spray cooling of a conventional screw steam compressor, Chinese patent publication No. CN105927548A discloses a water spray screw steam compressor, wherein three seals are arranged between a working cavity and a bearing cavity of the compressor, high-pressure liquid water is sprayed between a first seal and a second seal to realize steam sealing, and besides the sealing is realized by water spray, the water spray of a steam suction cavity can be used for reducing the superheat degree of steam suction and improving the mass flow of compressed steam; or water is sprayed to the compression cavity at the end of steam suction, so that the temperature of compressed steam and the superheat degree of exhausted steam are effectively reduced. The structure has the following disadvantages in practical use: the low-temperature vapor compression system has the defects of high purchase cost and complex system due to the sealing body and the system.

In view of the above-mentioned prior art, there is a need for a reasonable improvement of the structure of the existing screw vapor compressor. The applicant has therefore made an advantageous design, in the context of which the solution to be described below is made.

Disclosure of Invention

The invention aims to provide a low-temperature screw steam compressor, which not only effectively lubricates bearings at two ends of a rotor, but also effectively seals air inlet and exhaust, simplifies system configuration, reduces purchase and manufacturing cost, and solves the problems of complex main machine structure and overhigh system configuration when the conventional screw steam compressor is used for low-temperature steam compression.

The invention aims to solve the problem that the low-temperature screw steam compressor comprises a shell, a male rotor, a female rotor, a male rotor gear and a female rotor gear, wherein the male rotor gear is sleeved on the male rotor, the female rotor gear is sleeved on the female rotor, the male rotor gear and the female rotor gear are in meshing transmission, so that the male rotor and the female rotor are driven to be matched with each other to compress gas, a working area of the male rotor and the female rotor, which are matched with each other to compress gas, is a rotor cavity, one side of the compressor, which is close to an air inlet, is a low-pressure side, one side of the compressor, which is close to an air outlet, is a high-pressure side, and bearings and sealing structures are uniformly arranged at two ends of the low-pressure side and the high-pressure side of the male rotor and the female rotor.

In a specific embodiment of the present invention, the male rotor includes a male rotor tooth portion having a thread tooth portion and two rotor shafts extending from both ends of the male rotor tooth portion, the female rotor includes a female rotor tooth portion having a thread tooth portion and two rotor shafts extending from both ends of the female rotor tooth portion, the bearings mounted on the rotor shafts of the male rotor and the female rotor on the low pressure side are needle roller bearings, the needle roller bearings are provided with sealing structures, the sealing structures are low pressure side sealing rings, and the low pressure side sealing rings are distributed at both ends of the needle roller bearings.

In another specific embodiment of the present invention, the needle bearings are lubricated with grease, which is stored inside the needle bearings.

In a further specific embodiment of the present invention, an air intake end bearing seat is provided at an end of the inside of the casing close to the air intake port, the air intake end bearing seat is provided with a low pressure side bearing hole, needle bearings mounted on the rotor shafts of both the male rotor and the female rotor are mounted in the low pressure side bearing hole, and the low pressure side bearing hole is a hole opened toward the rotor portion.

In another embodiment of the present invention, the male rotor and the female rotor are made of stainless steel, and the housing is made of stainless steel.

In yet another specific embodiment of the invention, the bearings mounted on the rotor shaft on the high pressure side of both the male and female rotors are cylindrical roller bearings and four-point contact ball bearings.

In a further specific embodiment of the present invention, a high-pressure side seal ring and a slinger are installed between the male rotor teeth of the male rotor and the bearing and between the female rotor teeth of the female rotor and the bearing.

In a more specific embodiment of the invention, both the male rotor gear and the female rotor gear are arranged on the other end of the bearing far away from the rotor cavity, and the meshing transmission is arranged in a gear box body, the bottom of the gear box body is filled with lubricating oil, and the tooth surface of part of the gear is immersed below the level of the lubricating oil.

In yet another specific embodiment of the present invention, an oil buffer cavity is left between the high-pressure side seal ring and the oil slinger, and an oil return channel communicated with the gear box body is configured at the bottom of the oil buffer cavity.

In a still more specific embodiment of the invention, the rotor shaft of the female rotor on the high pressure side is provided with a shaft seal on the shaft section extending into the gearbox.

Due to the adoption of the structure, the invention has the beneficial effects that:

firstly, the invention adopts needle roller bearings with sealing rings and sealing ring structures on rotor shafts at two sides of a female rotor and a male rotor to realize the sealing of low-temperature steam, because the inlet and the outlet of a low-temperature screw rod steam compressor are all negative pressure, the bearings only bear little gas force, meanwhile, because the steam temperature is low, the heating effect on lubricating oil is small, the bearings close to the air inlet side adopt grease lubrication to realize self-lubrication, the bearings close to the air outlet side adopt gear splash oil lubrication, a complex lubricating oil system is not required to be configured for forced oil lubrication, the purchase cost and the floor area of a compressor unit are reduced, the operation is simpler, the lubrication of gears, bearings and shaft seals of a main machine can be realized by means of self-lubrication, the system configuration is simplified, and the purchase and manufacturing cost is reduced.

Secondly, because the inlet and outlet of the low-temperature screw rod vapor compressor are both negative pressure, the low-temperature steam can be effectively sealed by adopting the needle roller bearing with the sealing ring structure, and the low-temperature steam exhaust can be sealed by adopting the sealing ring structure at the other end, so that complicated carbon ring sealing or mechanical sealing and corresponding sealing systems do not need to be configured independently, and the purchase cost of a host and the system is reduced.

And thirdly, the sealing ring on the exhaust side isolates the oil buffer cavity and the rotor cavity, so that lubricating oil in the buffer cavity cannot enter the rotor cavity, and meanwhile, lubricating oil in the oil buffer cavity provides lubrication for the sealing ring.

Drawings

FIG. 1 is a schematic cross-sectional view of a cryogenic screw vapor compressor according to the present invention.

FIG. 2 is another schematic cross-sectional view of the cryogenic screw vapor compressor of the present invention.

In the figure: 1. an air inlet; 2. an exhaust port; 3. the engine comprises a shell, a 31, an air inlet end bearing block, 311, a first bearing hole, 312 and a second bearing hole; 4. a male rotor, 41. male rotor teeth, 42. low pressure side male rotor shaft, 43. high pressure side male rotor shaft; 5. a female rotor 51, female rotor teeth 52, a low pressure side female rotor shaft 53, a high pressure side female rotor shaft; 6. a male rotor gear; 7. a female rotor gear; 8. a gear housing; 9. a needle bearing I; 9' needle roller bearing II; 91. a low pressure side seal ring; 10. a cylindrical roller bearing I; 10' a cylindrical roller bearing II; 11. a first four-point contact ball bearing; 11', four-point contact ball bearing II; 12. a first sealing ring; 12', a second sealing ring; 13. a first oil deflector ring; 13' oil slinger II; 14. an oil return passage; 15. shaft sealing; 16. an oil buffer cavity; 17. a front end cover; 18. and a bearing seat.

Detailed Description

The following detailed description of the embodiments of the present invention will be described with reference to the accompanying drawings, but the description of the embodiments is not intended to limit the technical solutions, and any changes in form and not essential to the inventive concept should be regarded as the protection scope of the present invention.

In the following description, all the concepts related to the directions or orientations of up, down, left, right, front and rear are based on the position shown in fig. 2, and thus should not be construed as particularly limiting the technical solution provided by the present invention.

Referring to fig. 1 and 2, the present invention relates to a low temperature screw vapor compressor, which includes a casing 3, a male rotor 4, a female rotor 5, a male rotor gear 6 sleeved on the male rotor 4, and a female rotor gear 7 sleeved on the female rotor 5. The male rotor 4 and the female rotor 5 are mutually matched and arranged in the inner cavity of the machine shell 3, namely a rotor cavity for installing the rotors. The male rotor gear 6 and the female rotor gear 7 are in meshed transmission. The front end of the casing 3 of the low-temperature screw steam compressor is provided with a front end cover 17, the rear end of the casing is provided with a bearing seat 18, the other end of the bearing seat 18 is provided with a gear box body 8, and the male rotor gear 6 and the female rotor gear 7 are arranged in the gear box body 8.

Gas media are injected into the inner cavity of the machine shell 3, under the drive of the male rotor gear 6 and the female rotor gear 7, the male rotor 4 and the female rotor 5 are matched with each other to compress the gas media, air is sucked at the air inlet 1, and the gas entering the inner cavity, namely the rotor cavity is compressed and then exhausted at the air outlet 2. The low-temperature screw vapor compressor has the air inlet temperature of 40-50 ℃ and the air outlet temperature of 60-70 ℃, and the air inlet pressure and the air outlet pressure are negative pressure. Therefore, the side close to the inlet port 1 is the inlet side and the low pressure side of the compressor, the side close to the outlet port 2 is the outlet side and the high pressure side of the compressor, and the rotor chamber is the vapor compression working region.

An air inlet end bearing seat 31 is arranged at one end, close to the air inlet 1, in the machine shell 3, and a first bearing hole 311 and a second bearing hole 312 are arranged on the air inlet end bearing seat 31. The first bearing hole 311 and the second bearing hole 312 are collectively referred to as a low-pressure side bearing hole, and the low-pressure side bearing hole is a hole which is opened only towards the rotor part.

The male rotor 4 comprises a male rotor tooth 41 with a thread tooth and two sections of rotor shafts extending from two axial ends of the male rotor tooth 41, in this embodiment, the two sections of rotor shafts of the male rotor 4 are a low-pressure side male rotor shaft 42 located on a low-pressure side and a high-pressure side male rotor shaft 43 located on a high-pressure side; the female rotor 5 includes a female rotor tooth 51 having a thread tooth and two rotor shafts respectively extending from two ends of the female rotor tooth 51, in this embodiment, the two rotor shafts of the female rotor 5 are a low-pressure side female rotor shaft 52 located at a low-pressure side and a high-pressure side female rotor shaft 53 located at a high-pressure side.

The high-pressure side female rotor shaft 53 extends out of the gear box body 8 and then is connected with an external power part, the external power part drives the female rotor 5 to rotate, the female rotor 5 drives the female rotor gear 7 to rotate, the female rotor gear 7 rotates to drive the male rotor gear 6 to rotate, then the male rotor 4 is driven to rotate, the female rotor 5 and the male rotor 4 are not in contact with each other, and a gas medium is compressed in the shell 3.

In this embodiment, the male rotor 4 and the female rotor 5 are both made of stainless steel, and the casing 3 is also made of stainless steel, so as to prevent corrosion of the structural members by liquid water in steam.

The low-pressure side male rotor shaft 42 of the male rotor 4 is provided with a first needle bearing 9, and the first needle bearing 9 is arranged in a first bearing hole 311 on the air inlet end bearing seat 31. And a second needle bearing 9 'is arranged on the low-pressure side female rotor shaft 52 of the female rotor 5, and the second needle bearing 9' is arranged in a second bearing hole 312 on the air inlet end bearing block 31. In this embodiment, the first needle bearing 9 and the second needle bearing 9' are collectively referred to as needle bearings, the needle bearings are lubricated by grease, and the grease is stored in the bearings. The needle bearing is provided with a sealing structure, and specifically, the sealing structure is a low-pressure side sealing ring 91. The low-pressure side sealing rings 91 are distributed at two ends of the needle bearing and used for isolating the needle bearing from the rotor cavity, so that no grease or oil gas enters the rotor cavity in the running process of the compressor.

A first seal ring 12, a first oil retainer ring 13, a first cylindrical roller bearing 10, a first four-point contact ball bearing 11 and a male rotor gear 6 are sequentially sleeved on a high-pressure side male rotor shaft 43 of the male rotor 4 from the end face of the male rotor tooth part 41. The first sealing ring 12, the first oil retainer 13, the first cylindrical roller bearing 10 and the first four-point contact ball bearing 11 are arranged in an inner cavity of the bearing seat 18. And a sealing ring II 12 ', an oil retainer ring II 13', a cylindrical roller bearing II 10 ', a four-point contact ball bearing II 11' and a female rotor gear 7 are sequentially sleeved on the high-pressure side female rotor shaft 53 of the female rotor 5 from the end surface of the female rotor tooth part 51. The second sealing ring 12 ', the second oil retainer ring 13', the second cylindrical roller bearing 10 'and the second four-point contact ball bearing 11' are arranged in the other inner cavity of the bearing seat 18. The first seal ring 12 and the second seal ring 12 'are collectively referred to as a high-pressure side seal ring, the first slinger 13 and the second slinger 13' are collectively referred to as a slinger, the first cylindrical roller bearing 10 and the second cylindrical roller bearing 10 'are collectively referred to as a cylindrical roller bearing, the first four-point contact ball bearing 11 and the second four-point contact ball bearing 11' are collectively referred to as a four-point contact ball bearing, and the cylindrical roller bearing and the four-point contact ball bearing may be collectively referred to as a bearing. And the four-point contact ball bearing arranged on the exhaust side bears the axial gas force on the high-pressure side.

The rotor structure is characterized in that the male rotor gear 6 and the female rotor gear 7 are both arranged on the other end part of the bearing, which is far away from the rotor cavity, the male rotor gear 6 and the female rotor gear 7 are arranged in the gear box body 8, the bottom of the gear box body 8 is provided with a lubricating oil storage space, a proper amount of lubricating oil is injected into the lubricating oil storage space, and part of the tooth surface of the gear is immersed below the liquid level of the lubricating oil.

The bearing and the high-pressure side sealing ring are lubricated in a gear splash lubricating oil mode, and lubricating oil is thrown and splashed to the bearing and a gear meshing part through the meshing of the male rotor gear 6 and the female rotor gear 7 and is used for providing lubrication and taking away heat.

The lubricating oil is thrown out by the male rotor gear 6 and the female rotor gear 7 in a meshed and rotating mode, the oil slinger arranged between the high-pressure side sealing ring and the bearing prevents most of the lubricating oil from entering the oil buffer cavity 16 between the oil slinger and the high-pressure side sealing ring, the bottom of the oil buffer cavity 16 is provided with an oil return channel 14 communicated with the gear box body 8, and a small amount of the lubricating oil entering the oil buffer cavity 16 through the oil slinger flows back into the gear box body 8 through the oil return channel 14.

The small amount of lubricating oil entering the oil buffer cavity 16 provides lubrication for the high-pressure side sealing ring and is isolated by the high-pressure side sealing ring to enter the rotor cavity.

A shaft seal 15 is arranged on a shaft section of the high-pressure side female rotor shaft 53 of the female rotor 5 extending into the gear box 8, and the shaft seal 15 is used for preventing oil-gas mixture in the gear box 8 from leaking to the environment.

Claims

1. The utility model provides a low temperature screw rod vapor compressor, includes casing (3), male rotor (4), cloudy rotor (5), overlaps and establish male rotor gear (6) on male rotor (4), overlap and establish cloudy rotor gear (7) on cloudy rotor (5), male rotor gear (6) and cloudy rotor gear (7) meshing transmission to drive male rotor (4) and cloudy rotor (5) compressed gas of mutually supporting, male rotor (4) and cloudy rotor (5) are mutually supported compressed gas's working area and are the rotor chamber, and one side that the compressor is close to air inlet (1) is the low pressure side, and one side that is close to gas vent (2) is the high pressure side, its characterized in that: both the male rotor (4) and the female rotor (5) are provided with bearings and sealing structures on both ends of the low pressure side and the high pressure side.

2. A cryogenic screw vapor compressor according to claim 1, wherein the male rotor (4) comprises male rotor teeth (41) having thread teeth and two rotor shafts extending from both axial ends of the male rotor teeth (41), the female rotor (5) comprises female rotor teeth (51) having thread teeth and two rotor shafts extending from both axial ends of the female rotor teeth (51), the bearings mounted on the rotor shafts on the low pressure side of both the male rotor (4) and the female rotor (5) are needle bearings, the needle bearings are self-sealing structures, the sealing structures are low pressure side sealing rings (91), and the low pressure side sealing rings (91) are distributed at both ends of the needle bearings.

3. A cryogenic screw vapor compressor as claimed in claim 2 wherein the needle bearings are lubricated with grease, the grease being stored within the needle bearings.

4. A cryogenic screw steam compressor according to claim 3, characterized in that an inlet end bearing block (31) is provided at an end of the interior of the casing (3) near the inlet port (1), the inlet end bearing block (31) is provided with a low pressure side bearing hole, needle bearings mounted on the rotor shafts of both the male rotor (4) and the female rotor (5) are mounted in the low pressure side bearing hole, and the low pressure side bearing hole is a hole opened partially toward the rotor.

5. A cryogenic screw vapor compressor according to claim 1, wherein the male rotor (4) and the female rotor (5) are both made of stainless steel and the casing (3) is made of stainless steel.

6. A cryogenic screw vapor compressor according to claim 1, characterized in that the bearings mounted on the rotor shaft on the high pressure side of both the male (4) and female (5) rotors are cylindrical roller bearings and four-point contact ball bearings.

7. A cryogenic screw vapor compressor according to claim 6, characterized in that a high pressure side seal ring and a slinger are mounted between the male rotor teeth (41) of the male rotor (4) to the bearing and between the female rotor teeth (51) of the female rotor (5) to the bearing.

8. A cryogenic screw vapor compressor according to claim 1, wherein both the male rotor gear (6) and the female rotor gear (7) are disposed on the other end of the bearing away from the rotor chamber and are mounted in a gear housing (8) in a meshing transmission manner, the bottom of the gear housing (8) is filled with lubricating oil, and part of the tooth surface of the gear is submerged below the level of the lubricating oil.

9. A cryogenic screw vapor compressor according to claim 7, characterized in that an oil buffer cavity (16) is left between the high pressure side seal ring and the oil slinger, and the bottom of the oil buffer cavity (16) is provided with an oil return channel (14) which is communicated with the gearbox housing (8).

10. A cryogenic screw vapor compressor according to claim 1, characterized in that the rotor shaft on the high pressure side of the female rotor (5) is provided with a shaft seal (15) on the shaft section extending into the gear box (8).