Single-stage tooth type centrifugal compressor

Abstract

The utility model discloses a single-stage tooth type centrifugal compressor which comprises a volute, an impeller cover, an impeller, a diffuser, a gear box, a balance disc and a balance disc housing. The impeller is arranged close to the impeller cover, and the balance disc is arranged close to the balance disc housing; the gear box is connected with the impeller and can drive the impeller to rotate; the gear box comprises an input rotor, a gear shaft, a bearing, a first flange plate and a second flange plate; the impeller is arranged at one end of the gear shaft, and the balance disc is arranged at the other end of the gear shaft; the gear shaft is supported in the gear box through a bearing; the input rotor is connected with a gear shaft and drives the gear shaft to rotate through meshing of a gear pair. A high-pressure side cavity and a low-pressure side cavity are formed in the two sides of the balance disc respectively. According to the single-stage tooth type centrifugal compressor provided by the utility model, the unit structure can be simplified, and the production cost can be reduced; and as an intercooler is not needed, the investment of cooling water can be reduced in a water-deficient area, and resources are saved.

Description

Technical Field

[0001] The utility model belongs to the technical field of compressors and relates to a centrifugal compressor, in particular to a single-stage tooth type centrifugal compressor. Background Art

[0002] When the centrifugal compressor is working, the gas pressure increases due to the work done by the impeller, making the pressure at the impeller outlet and the wheel back higher than the impeller inlet pressure, thereby generating an aerodynamic axial force pointing from the impeller outlet to the impeller inlet. The sum of the aerodynamic axial forces of each impeller must ultimately be borne by the thrust bearing.

[0003] For single-stage compression gear centrifugal units, when the impeller inlet pressure is low and the impeller pressure ratio is small, the aerodynamic axial force is relatively small, and the thrust bearing is sufficient to withstand the aerodynamic axial force. However, when the impeller inlet pressure is high and the impeller pressure ratio is large, the sum of the aerodynamic axial forces may often exceed the bearing capacity of the thrust bearing. In this case, the usual practice is to change the single-stage compression to a two-stage compression, and the second-stage impeller and the first-stage impeller are arranged back-to-back, so that the aerodynamic axial forces of the two-stage impellers are in opposite directions and offset each other, thereby reducing the sum of the aerodynamic axial forces to within the bearing capacity of the thrust bearing. However, the newly added first-stage compression requires additional investment in impellers, diffusers, impeller covers, volutes, interstage pipes, etc., and in order to improve the aerodynamic efficiency of the second stage, an intercooler is often required, which increases the complexity and production cost of the unit.

[0004] In view of this, there is an urgent need to design a new centrifugal compressor so as to overcome at least some of the above-mentioned defects of the existing centrifugal compressors. Utility Model Content

[0005] The utility model provides a single-stage tooth type centrifugal compressor, which can simplify the unit structure and reduce production costs; because no intermediate cooler is required, the cooling water input can be reduced in water-scarce areas, saving resources.

[0006] In order to solve the above technical problems, according to one aspect of the present invention, the following technical solutions are adopted:

[0007] A single-stage gear-type centrifugal compressor, comprising: a volute, an impeller cover, an impeller, a diffuser, a gear box, a balancing disc, and a balancing disc cover;

[0008] The volute and the balancing disc cover are respectively arranged at both ends of the gear box to form the external structure of the centrifugal compressor; the impeller cover, impeller, diffuser, gear box and balancing disc are arranged in the external structure;

[0009] The impeller is arranged near the impeller cover, and the balancing disc is arranged near the balancing disc housing; the gear box is connected to the impeller and can drive the impeller to rotate;

[0010] The gearbox includes an input rotor, a gear shaft, a bearing, a first flange and a second flange; the first flange is arranged between the volute and the impeller cover, and the second flange is arranged between the gearbox and the balancing disc housing;

[0011] The impeller is provided at one end of the gear shaft, and the balance disk is provided at the other end; the gear shaft is supported in the gear box through a bearing; the input rotor is connected to the gear shaft and drives the gear shaft to rotate through meshing of the gear pair;

[0012] A high-pressure side cavity and a low-pressure side cavity are respectively provided on both sides of the balancing disk. The high-pressure side cavity is connected to the compressor exhaust port and / or the process gas interface, and the low-pressure side cavity is connected to the compressor inlet, which can transport the airflow to the compressor inlet.

[0013] As an embodiment of the present invention, a sealing mechanism is provided between the balancing disc and the balancing disc cover to maintain the pressure difference on both sides of the balancing disc and prevent a large amount of gas on the high-pressure side from flowing into the low-pressure side.

[0014] As an embodiment of the present invention, an impeller side air seal is provided between the impeller and the gear shaft.

[0015] As an embodiment of the present invention, the gear shaft is supported in the gear box body through a first bearing and a second bearing respectively; a first oil seal is provided between the impeller side air seal and the first bearing.

[0016] As an embodiment of the present invention, a balancing disc side air seal is provided between the second flange and the gear shaft.

[0017] As an embodiment of the present invention, the gear shaft is supported in the gear box body by a first bearing and a second bearing respectively; a second oil seal is provided between the balancing disc side air seal and the second bearing.

[0018] As an embodiment of the present invention, the input rotor includes a rotor mechanism, and teeth are provided around the periphery of the rotor mechanism; teeth that can mesh with the teeth of the rotor mechanism are provided around the set area of ​​the gear shaft, so that the input rotor and the gear shaft form a gear pair.

[0019] The beneficial effects of the present invention are as follows: the single-stage toothed centrifugal compressor proposed by the present invention can simplify the unit structure and reduce production costs; since no intercooler is required, cooling water input can be reduced in water-scarce areas, saving resources.

[0020] In one usage scenario of the present invention, by accurately calculating the axial force of the balancing disk, the sum of the aerodynamic axial forces can be controlled within a smaller range close to 0. This not only greatly reduces the thrust bearing load and enables safe and stable operation, but also reduces the thrust bearing power consumption and improves the overall efficiency of the unit. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 This is a structural diagram of a single-stage tooth-type centrifugal compressor in one embodiment of the present invention.

[0022] Figure 2 This is a schematic diagram of the structure of the input rotor and the gear shaft in one embodiment of the present utility model. DETAILED DESCRIPTION

[0023] The preferred embodiments of the present utility model are described in detail below with reference to the accompanying drawings.

[0024] In order to further understand the present invention, preferred embodiments of the present invention are described below in conjunction with examples. However, it should be understood that these descriptions are only for further illustrating the features and advantages of the present invention, rather than limiting the claims of the present invention.

[0025] The description in this section is only for several typical embodiments, and the present invention is not limited to the scope of the embodiments. The same or similar existing technical means and some technical features of the embodiments are interchangeable and fall within the scope of the description and protection of the present invention.

[0026] The term “connection” in the specification includes both direct connection and indirect connection.

[0027] The utility model discloses a single-stage tooth type centrifugal compressor. Figure 1 This is a schematic diagram of the structure of a single-stage toothed centrifugal compressor in one embodiment of the present invention; Figure 1 The single-stage tooth centrifugal compressor includes: a volute 1, an impeller cover, an impeller 2, a diffuser 3, a gear box 4, a balancing disk 5 and a balancing disk cover 6.

[0028] The volute 1 and balancing disc housing 6 are respectively mounted at both ends of the gearbox 4, forming the external structure of the centrifugal compressor. The impeller cover, impeller 2, diffuser 3, gearbox 4, and balancing disc 5 are mounted within this external structure. The impeller 2 is positioned near the impeller cover, and the balancing disc 5 is positioned near the balancing disc housing 6. The gearbox 4 is connected to the impeller 2 and can drive its rotation. The diffuser's function is to decelerate the high-velocity airflow exiting the impeller, effectively converting kinetic energy into pressure energy.

[0029] The gearbox 4 includes an input rotor 41 , a gear shaft 42 , a bearing 43 , a first flange 44 and a second flange 45 ; the first flange 44 is disposed between the volute 1 and the gearbox 4 , and the second flange 45 is disposed between the gearbox 4 and the balancing disc housing 6 .

[0030] The impeller 2 is provided at one end of the gear shaft 42, and the balancing disk 5 is provided at the other end; the gear shaft 42 is supported in the gear box 4 through a bearing 43; the input rotor 41 is connected to the gear shaft 42, and drives the gear shaft 42 to rotate through the engagement of the gear pair.

[0031] A high-pressure side cavity and a low-pressure side cavity are respectively provided on both sides of the balancing disk 5. The high-pressure side cavity is connected to the compressor exhaust port and / or the process gas interface, and the low-pressure side cavity is connected to the compressor inlet, which can transport the airflow to the compressor inlet.

[0032] In one embodiment of the present invention, a sealing mechanism 7 is provided between the balancing disc 5 and the balancing disc cover 6 to maintain a pressure difference between the two sides of the balancing disc 5 and prevent a large amount of gas on the high-pressure side from flowing into the low-pressure side.

[0033] An impeller side air seal 8 is provided between the impeller 2 and the gear shaft 42. The gear shaft 42 is supported in the gear box 42 via a first bearing 431 and a second bearing 432. A first oil seal 10 is provided between the impeller side air seal 8 and the first bearing 431.

[0034] A balancing disc side air seal 9 is provided between the second flange 45 and the gear shaft 42. The gear shaft 42 is supported within the gear box 42 via a first bearing 431 and a second bearing 432. A second oil seal 11 is provided between the balancing disc side air seal 9 and the second bearing 432.

[0035] Figure 2 This is a schematic diagram of the structure of the input rotor and the gear shaft in one embodiment of the present invention; please refer to Figure 2 In one embodiment of the present invention, the input rotor 41 includes a rotor mechanism, and teeth are provided on the periphery of the rotor mechanism; teeth that can mesh with the teeth of the rotor mechanism are provided on the periphery of a set area of ​​the gear shaft 42, and the gear shaft is driven to rotate when the input rotor rotates through the meshing action of the gear pair between the input rotor and the gear shaft.

[0036] In one use scenario of the present invention, the gearbox is the core component of the entire unit, which has an input rotor, a high-speed gear shaft, bearings, oil seals, flanges, etc. The high-speed gear shaft can be Figure 1The structure shown is equipped with a composite bearing, which bears the resultant of the pneumatic axial force. It can also be a thrust chuck structure with a radial bearing. The resultant of the pneumatic axial force is transmitted to the input rotor through the thrust chuck and is finally borne by the input rotor thrust bearing.

[0037] The volute, impeller cover, diffuser, impeller and impeller side gas seal are conventional matching parts. An O-ring seal is installed at the mating plane between the volute and the flange to prevent medium leakage. The gas seal is used to prevent a large amount of medium from leaking into the atmosphere. The gas seal form can be selected from labyrinth gas seal, carbon ring gas seal or dry gas seal according to different media and pressure.

[0038] The balancing disc is generally made of high-strength alloy steel or stainless steel and can be installed on the high-speed shaft by shrink fitting or screws. The balancing disc seal is generally a comb seal or a carbon ring seal and can be installed on the balancing disc cover by screws. The balancing disc cover needs to withstand the entire high-pressure side and low-pressure side air pressure without damage or leakage. It can be installed on the gearbox by high-strength bolts or studs, and an O-ring seal is set on the mating plane with the gearbox. If necessary, a condensate drain valve can be set at the bottom of the high-pressure side and the low-pressure side to drain condensate.

[0039] When the unit is operating normally, the impeller will generate an aerodynamic axial force pointing from the outlet to the inlet, and the balance disk will generate an axial force pointing from the high-pressure side to the low-pressure side. The two forces are in opposite directions and offset each other, thereby achieving the purpose of reducing the load on the thrust bearing or thrust chuck. For units with variable operating conditions, it is also necessary to comprehensively evaluate the aerodynamic axial force and the axial force generated by the balance disk under different operating conditions, and reasonably set the size of the balance disk so that the final axial force under each operating condition is within the range that the thrust bearing or thrust chuck can withstand.

[0040] In summary, the single-stage toothed centrifugal compressor proposed in the present invention can simplify the unit structure and reduce production costs; since no intercooler is required, cooling water input can be reduced in water-scarce areas, saving resources.

[0041] In one usage scenario of the present invention, by accurately calculating the axial force of the balancing disk, the sum of the aerodynamic axial forces can be controlled within a smaller range close to 0. This not only greatly reduces the thrust bearing load and enables safe and stable operation, but also reduces the thrust bearing power consumption and improves the overall efficiency of the unit.

[0042] The technical features of the above-mentioned embodiments can be combined arbitrarily. In order to make the description concise, not all possible combinations of the technical features in the above-mentioned embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0043] The description and application of the present invention here are illustrative and are not intended to limit the scope of the present invention to the above-mentioned embodiments. The effects or advantages involved in the embodiments may not be reflected in the embodiments due to interference from various factors, and the description of the effects or advantages is not used to limit the embodiments. Variations and changes to the embodiments disclosed here are possible, and replacements and various equivalent components of the embodiments are well known to those of ordinary skill in the art. It should be clear to those skilled in the art that, without departing from the spirit or essential characteristics of the present invention, the present invention can be implemented in other forms, structures, arrangements, proportions, and with other components, materials and parts. Other variations and changes can be made to the embodiments disclosed here without departing from the scope and spirit of the present invention.

Claims

1. A single-stage tooth centrifugal compressor, characterized in that: The single-stage gear centrifugal compressor includes: a volute, an impeller cover, an impeller, a diffuser, a gear box, a balancing disc and a balancing disc cover; The volute and the balancing disc cover are respectively arranged at both ends of the gear box to form the external structure of the centrifugal compressor; the impeller cover, impeller, diffuser, gear box and balancing disc are arranged in the external structure; The impeller is arranged near the impeller cover, and the balancing disc is arranged near the balancing disc housing; the gear box is connected to the impeller and can drive the impeller to rotate; The gearbox includes an input rotor, a gear shaft, a bearing, a first flange and a second flange; the first flange is arranged between the volute and the gearbox, and the second flange is arranged between the gearbox and the balancing disc housing; The impeller is provided at one end of the gear shaft, and the balance disk is provided at the other end; the gear shaft is supported in the gear box through a bearing; the input rotor is connected to the gear shaft and drives the gear shaft to rotate through meshing of the gear pair; A high-pressure side cavity and a low-pressure side cavity are respectively provided on both sides of the balancing disk. The high-pressure side cavity is connected to the compressor exhaust port and / or the process gas interface; the low-pressure side cavity is connected to the compressor inlet and can transport the airflow to the compressor inlet.

2. The single-stage tooth centrifugal compressor according to claim 1, characterized in that: A sealing mechanism is provided between the balancing disc and the balancing disc cover to maintain the pressure difference on both sides of the balancing disc and prevent a large amount of gas on the high-pressure side from flowing into the low-pressure side.

3. The single-stage tooth centrifugal compressor according to claim 1, characterized in that: An impeller side air seal is provided between the impeller and the gear shaft.

4. The single-stage tooth centrifugal compressor according to claim 3, characterized in that: The gear shaft is supported in the gear box body through a first bearing and a second bearing respectively; a first oil seal is provided between the impeller side air seal and the first bearing.

5. The single-stage tooth centrifugal compressor according to claim 1, characterized in that: A balancing disc side air seal is provided between the second flange and the gear shaft.

6. The single-stage tooth centrifugal compressor according to claim 5, characterized in that: The gear shaft is supported in the gear box body through a first bearing and a second bearing respectively; a second oil seal is provided between the balancing disc side air seal and the second bearing.

7. The single-stage tooth centrifugal compressor according to claim 1, characterized in that: The input rotor includes a rotor mechanism, and teeth are provided on the periphery of the rotor mechanism; teeth that can mesh with the teeth of the rotor mechanism are provided on the periphery of a set area of ​​the gear shaft, so that the input rotor and the gear shaft form a gear pair.

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