High-speed centrifugal air compressor

Abstract

The invention relates to a high-speed centrifugal air compressor, and relates to the technical field of motor cooling, the high-speed centrifugal air compressor comprises a casing, a power system, two damping bearing systems and two compression systems, the power system is installed in the casing through the two damping bearing systems, the power system is provided with two output ends, and the two output ends are connected with the two compression systems. The compression system comprises two impellers and two volutes, each volute is sequentially provided with an air inlet, a pressurizing cavity and a spiral output pipe, the spiral output pipe of one volute is communicated with the air inlet of the other volute after passing through the air cooler, and the impellers are mounted at the corresponding output ends of the power system. The impellers are rotatably mounted in the pressurizing cavity, a plurality of water injection openings are formed in the inner sides of the air inlets of the volutes, the air compression efficiency is high, and the burden of the motor is small.

Description

Technical Field

[0001] The present invention relates to the technical field of motor cooling, and particularly to a high-speed centrifugal air compressor. Background Art

[0002] ‌A centrifugal air compressor‌ is a device that uses the impeller rotating at high speed by a motor to do work on the gas, and improves the gas pressure through the action of centrifugal force. Its working principle is that the impeller drives the gas to rotate at high speed in the volute, causing the gas to generate centrifugal force, so that the flow rate and pressure after the impeller are increased, and compressed air is continuously produced‌. The cooling of its motor and other components has always been a difficult problem.

[0003] A centrifugal air compressor mainly consists of two parts: a rotor and a stator. The rotor includes an impeller and a shaft, and there are blades on the impeller. The main body of the stator is a casing (cylinder), and there are also arranged a diffuser, a bend, a return pipe, an intake pipe, an exhaust pipe and some shaft seals, etc. When the impeller rotates at high speed, the gas rotates with it and is thrown into the diffuser behind under the action of centrifugal force, forming a vacuum zone, and fresh gas from the outside enters the impeller. The impeller rotates continuously, and the gas is continuously inhaled and thrown out, maintaining the continuous flow of the gas‌.

[0004] Moreover, when the impeller rotates, due to the gap between the impeller and the volute, there will be air pressure loss, resulting in the need to further increase the motor speed, which is more unfavorable for heat dissipation. Summary of the Invention

[0005] To overcome the technical defects existing in the prior art, the present invention provides a high-speed centrifugal air compressor with high air compression efficiency and small motor load.

[0006] The technical solution adopted by the present invention is: A high-speed centrifugal air compressor includes a casing, a power system, two shock-absorbing bearing systems and two compression systems. The power system is installed in the casing through the two shock-absorbing bearing systems. The power system has two output ends. The compression system includes two impellers and two volutes. Each of the two volutes is sequentially provided with an air inlet, a pressurizing chamber and a spiral output pipe. The spiral output pipe of one of the volutes is connected to the air inlet of the other volute after passing through an air cooler. Each of the impellers is installed at the corresponding output end of the power system, and each of the impellers is rotatably installed in the pressurizing chamber. A plurality of water injection ports are arranged inside the air inlet of each of the volutes.

[0007] Preferably, the power system includes a stator, an intermediate section and two rotor shafts. The two rotor shafts are respectively rotatably installed on the casing through the corresponding shock-absorbing bearing systems. The stator is installed on the casing. The two rotor shafts are installed through the intermediate section, and the two rotor shafts respectively form output ends.

[0008] Preferably, each of the shock-absorbing bearing systems includes a mounting end cover, an oil injection device, a sealing device, and a bearing device. The mounting end cover is installed on the side of the casing. The output end passes through the bearing device. The sealing device is installed on the mounting end cover and is in sealing contact with the output ends on both sides of the bearing device. The mounting end cover has an oil injection nozzle near the bearing device. The mounting end cover presses on the shock-absorbing bearing system and supports the shock-absorbing bearing system. The oil injection device is communicated with the oil injection nozzle. An oil injection channel communicating with the oil injection nozzle is opened on the mounting end cover. The oil injection device points to the bearing device.

[0009] Preferably, the oil injection device is a threaded needle pointing to the bearing device, and the threaded needle is communicated with the oil injection channel.

[0010] Preferably, the bearing device includes a bearing frame and a load-bearing bearing. The inner ring of the load-bearing bearing is installed on the output end, and the outer ring of the load-bearing bearing is installed in the mounting end cover through the bearing frame. The oil injection channel is communicated between the bearing frame and the mounting end cover.

[0011] Preferably, the sealing device includes an inner end cover of the end cover, an inner oil seal, an outer oil seal cover, and an outer end cover of the end cover. The outer oil seal cover and the inner oil seal are both sleeved on the output end. The outer oil seal cover and the inner oil seal are respectively located on the output ends on both sides of the bearing device. The outer end cover of the end cover and the inner end cover of the end cover are respectively installed on both sides of the mounting end cover. The inner end cover of the end cover and the inner oil seal are in sliding seal, and the outer oil seal cover and the outer end cover of the end cover are in sliding seal.

[0012] Preferably, each of the volutes is installed on the side of the shock-absorbing bearing system through a volute end cover.

[0013] Preferably, a stepped sealing sleeve and a stepped sealing cover are further installed on the output end. The stepped sealing sleeve is sleeved on the output end and is located between the impeller and the shock-absorbing bearing system. The outer oil seal cover is installed on the volute end cover, and the stepped sealing sleeve and the stepped sealing cover are in sliding seal.

[0014] The beneficial effects of the present invention are: The power system is installed in the housing through two shock-absorbing bearing systems to generate power. The power system has two output ends. The compression system includes two impellers and two volutes. Each of the two volutes is sequentially provided with an air inlet, a pressurization chamber, and a spiral output pipe. The spiral output pipe of one volute is connected to the air inlet of the other volute after passing through an air cooler. The air cooler cools the hot air in one spiral output pipe and then sends it into the other air inlet for re-pressurization. Each impeller is installed at the corresponding output end of the power system, thereby driving the impeller to rotate. Each impeller is rotatably installed in the pressurization chamber. Inside the air inlet of each volute, there are several water injection ports to form a water film between the pressurization chamber and the impeller, strengthening the seal between the pressurization chamber and the impeller and improving the compression efficiency. On the other hand, this water film is located between the pressurization chamber and the impeller. When the impeller rotates at high speed, the water film not only takes away the heat of the impeller, but also, because the water film plays a supporting role between the pressurization chamber and the impeller, it is beneficial to eliminate the rotational imbalance of the impeller. Moreover, due to the large specific heat capacity of water, when the impeller pressurizes the air, the water reduces the air temperature, making the air temperature decrease, playing a role in pre-cooling the air in advance and increasing the air compression ratio. Since the above two compression systems are connected in series, in order to dehydrate the compressed air, the water injection ports only inject water at the position of the previous compression system. After passing through the above-described air cooler, the water contained in the air and the water input from the water injection ports are condensed and discharged. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 It is a schematic structural diagram of the present invention.

[0016] Figure 2 It is a schematic cross-sectional structural diagram of the present invention.

[0017] Figure 3 is Figure 2 an enlarged schematic diagram of part A in

[0018] Figure 4 is Figure 2 an enlarged schematic diagram of part B in

[0019] Description of the reference numerals: 1. Housing; 2. Power system; 21. Stator; 22. Intermediate section; 23. Rotor shaft; 3. Shock-absorbing bearing system; 31. Oil injection device; 311. Threaded needle head; 32. Sealing device; 321. Inner end cover; 322. Inner oil seal; 323. Outer oil seal cover; 324. Outer end cover; 325. Oil injection channel; 33. Bearing device; 332. Mounting end cover; 333. Load-bearing bearing; 334. Bearing bracket; 4. Compression system; 41. Impeller; 42. Volute; 421. Air inlet; 4211. Water injection port; 422. Pressurization chamber; 423. Spiral output pipe; 425. Volute end cover; 5. Fuel injector; 61. Step seal sleeve; 62. Step seal cover. Detailed implementation mode

[0020] The present invention will be further described below with reference to the accompanying drawings: As Figure 1 — Figure 4 shown, this embodiment provides a high-speed centrifugal air compressor, which includes a housing 1, a power system 2, two shock-absorbing bearing systems 3 and two compression systems 4. The power system 2 is installed in the housing 1 through the two shock-absorbing bearing systems 3 to generate power. The power system 2 has two output ends. The compression system 4 includes two impellers 41 and two volutes 42. The two volutes 42 are each sequentially provided with an air inlet 421, a pressurizing chamber 422 and a spiral output pipe 423. The spiral output pipe 423 of one volute 42 is connected to the air inlet 421 of the other volute 42 after passing through an air cooler. The air cooler cools the hot air in one spiral output pipe 423 and then sends it into the other air inlet 421 for re-pressurization. Each impeller 41 is installed at the corresponding output end of the power system 2, thereby driving the impeller 41 to rotate. Each impeller 41 is rotatably installed in the pressurizing chamber 422. A number of water injection ports 4211 are provided inside the air inlet 421 of each volute to form a water film between the pressurizing chamber 422 and the impeller 41, strengthening the seal between the pressurizing chamber 422 and the impeller 41, improving the compression efficiency and reducing the burden on the motor. On the other hand, this water film is located between the pressurizing chamber 422 and the impeller 41. When the impeller 41 rotates at a high speed, the water film not only takes away the heat of the impeller 41, but also, since this water film plays a supporting role between the pressurizing chamber 422 and the impeller 41, it is beneficial to eliminate the rotational imbalance of the impeller 41. And because the specific heat capacity of water is large, when the impeller 41 pressurizes the air, the water reduces the air temperature, making the air temperature decrease, playing a role in pre-cooling the air in advance and increasing the compression ratio of the air. Since the two compression systems 4 described above are connected in series, in order to dehydrate the compressed air, the water injection port 4211 only injects water at the position of the compression system 4 in the front stage. After passing through the air cooler described above, the water contained in the air and the water input from the water injection port 4211 are condensed and discharged.

[0021] Specifically, the power system 2 includes a stator 21, an intermediate section 22 and two rotor shafts 23. The two rotor shafts 23 are respectively rotatably installed on the housing 1 through the corresponding shock-absorbing bearing systems 3. The stator 21 is installed on the housing 1. The two rotor shafts 23 are installed through the intermediate section 22, thereby realizing the synchronous rotation of the two rotor shafts 23. The two rotor shafts 23 respectively constitute the output ends.

[0022] Specifically, each shock-absorbing bearing system 3 includes a mounting end cover 332, an oil injection device 31, a sealing device 32, and a bearing device 33. The mounting end cover 332 is installed on the side of the casing 1, and the output end passes through the bearing device 33. The sealing device 32 is installed on the mounting end cover 332 and is in sealed contact with the output ends on both sides of the bearing device 33. The mounting end cover 332 has an oil injection nozzle 5 near the bearing device 33. The mounting end cover 332 presses on the shock-absorbing bearing system 3 and supports the shock-absorbing bearing system 3. The oil injection device 31 is communicated with the oil injection nozzle 5. An oil injection channel 325 communicating with the oil injection nozzle 5 is provided on the mounting end cover 332. The oil injection device 31 points to the bearing device 33, and lubricating oil is injected from the oil injection channel 325. After the lubricating oil is injected from the oil injection channel 325, it is divided into two paths. One path is injected into the gap between the mounting end cover 332 and the bearing device 33 from the oil injection nozzle 5. The lubricating oil in the gap between the mounting end cover 332 and the bearing device 33 provides a buffer space for the rotational vibration of the bearing device 33. The other path is sprayed onto the bearing device 33 through the oil injection device 31 for lubrication.

[0023] Specifically, the oil injection device 31 is a threaded needle 311 pointing to the bearing device 33. The threaded needle 311 is communicated with the oil injection channel 325, which is convenient for lubricating and dissipating heat of the bearing device 33.

[0024] Specifically, the bearing device 33 includes a bearing housing 334 and a load-bearing bearing 333. The inner ring of the load-bearing bearing 333 is installed on the output end, and the outer ring of the load-bearing bearing 333 is installed in the mounting end cover 332 through the bearing housing 334. The oil injection channel 325 is communicated with the space between the bearing housing 334 and the mounting end cover 332 through the oil injection nozzle 5. Lubricating oil is injected from the oil injection channel 325 and flows into the oil injection nozzle 5 to spray high-pressure lubricating oil to the bearing housing 334, so that the bearing housing 334 floats in the center of the mounting end cover 332. The mounting end cover 332 is installed on the side of the casing 1, thereby realizing the rotational installation of the output end. Since there is lubricating oil with pressure filled between the bearing housing 334 and the mounting end cover 332, the impact brought by the rotation of the intermediate section 22, the two rotor shafts 23, and the impeller 41 is eliminated, deformation is prevented, large vibrations are avoided, and slight vibrations are eliminated in real time.

[0025] Specifically, the sealing device 32 includes an inner end cover 321, an inner oil seal 322, an outer oil seal cover 323, and an outer end cover 324. Both the outer oil seal cover 323 and the inner oil seal 322 are sleeved on the output end, and the outer oil seal cover 323 and the inner oil seal 322 are respectively located on the output ends on both sides of the bearing device 33. The outer end cover 324 and the inner end cover 321 are respectively installed on both sides of the mounting end cover 332. The inner end cover 321 and the inner oil seal 322 are in sliding seal, and the outer oil seal cover 323 and the outer end cover 324 are in sliding seal. This avoids the leakage of lubricating oil.

[0026] Specifically, each volute 42 is respectively installed on the side of the mounting end cover 332 of the shock-absorbing bearing system 3 through the volute end cover 425.

[0027] Specifically, a stepped sealing sleeve 61 and a stepped sealing cover 62 are further installed on the output end. The stepped sealing sleeve 61 is sleeved on the output end. The stepped sealing sleeve 61 is located between the impeller 41 and the shock-absorbing bearing system 3. The stepped sealing cover 62 is installed on the volute end cover 425. The stepped sealing sleeve 61 and the stepped sealing cover 62 are in sliding seal to further prevent the leakage of lubricating oil.

[0028] The above shows and describes the basic principles, main features and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited by the above embodiments. What is described in the above embodiments and the specification only illustrates the principle of the present invention. Without departing from the spirit and scope of the present invention, the present invention will have various changes and improvements, and these changes and improvements all fall within the scope of the present invention claimed. The scope of the present invention claimed is defined by the appended claims and their equivalents.

Claims

1. A high-speed centrifugal air compressor, characterized in that: It includes a casing, a power system, two shock-absorbing bearing systems and two compression systems. The power system is installed in the casing through the two shock-absorbing bearing systems. The power system has two output ends. The compression system includes two impellers and two volutes. The two volutes are respectively provided with an air inlet, a pressurizing chamber and a spiral output pipe. The spiral output pipe of one volute is connected to the air inlet of the other volute after passing through an air cooler. Each impeller is installed at the corresponding output end of the power system. Each impeller is rotatably installed in the pressurizing chamber. A plurality of water injection ports are provided on the inner side of the air inlet of each volute.

2. A high-speed centrifugal air compressor according to claim 1, characterized in that: The power system includes a stator, an intermediate section and two rotor shafts. The two rotor shafts are rotatably mounted on the casing through corresponding shock-absorbing bearing systems. The stator is mounted on the casing, and the two rotor shafts are mounted through the intermediate section. The two rotor shafts constitute output ends respectively.

3. A high-speed centrifugal air compressor according to claim 1, characterized in that: Each of the shock-absorbing bearing systems includes a mounting end cover, an oil injection device, a sealing device and a bearing device. The mounting end cover is mounted on the side of the casing, and the output end passes through the bearing device. The sealing device is mounted on the mounting end cover. The sealing device is in sealing contact with the output ends on both sides of the bearing device. The mounting end cover has an oil spray nozzle near the bearing device. The mounting end cover is pressed on the shock-absorbing bearing system. The mounting end cover supports the shock-absorbing bearing system. The oil injection device is connected to the oil spray nozzle. An oil injection channel connected to the oil spray nozzle is opened on the mounting end cover. The oil injection device points to the bearing device.

4. A high-speed centrifugal air compressor according to claim 3, characterized in that: The oil injection device is a threaded needle pointing to the bearing device, and the threaded needle is connected to the oil injection channel.

5. A high-speed centrifugal air compressor according to claim 3, characterized in that: The bearing device includes a bearing frame and a load-bearing bearing, the inner ring of the load-bearing bearing is installed on the output end, the outer ring of the load-bearing bearing is installed in the mounting end cover through the bearing frame, and the oil injection channel is connected to between the bearing frame and the mounting end cover through an oil spray nozzle.

6. A high-speed centrifugal air compressor according to claim 3, characterized in that: The sealing device comprises an end cover inner cover, an inner oil seal, an oil seal outer cover and an end cover outer cover, the oil seal outer cover and the inner oil seal are both sleeved on the output end, the oil seal outer cover and the inner oil seal are respectively located on the output ends on both sides of the bearing device, the end cover outer cover and the end cover inner cover are respectively installed on both sides of the mounting end cover, the end cover inner cover and the inner oil seal are slidingly sealed, and the oil seal outer cover and the end cover outer cover are slidingly sealed.

7. A high-speed centrifugal air compressor according to claim 6, characterized in that: Each of the volutes is installed on the side of the shock-absorbing bearing system through a volute end cover.

8. A high-speed centrifugal air compressor according to claim 7, characterized in that: A stepped sealing sleeve and a stepped sealing cover are also installed on the output end. The stepped sealing sleeve is arranged on the output end, the stepped sealing sleeve is located between the impeller and the shock-absorbing bearing system, the oil seal outer cover is installed on the volute end cover, and the stepped sealing sleeve and the stepped sealing cover are slidingly sealed.

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