Expansion machine for balancing axial thrust

Abstract

The utility model belongs to the technical field of expansion machines, and particularly relates to an expansion machine for balancing axial thrust, which comprises a main shaft, an expansion end and a pressurization end, the expansion end is arranged at one end of the main shaft, the pressurization end is arranged at the other end of the main shaft, an expansion wheel is arranged in the expansion end, a press wheel is arranged in the pressurization end, and the pressurization end is connected with an inlet pipe; the pressurizing end is connected with the back side of the press wheel, a balancing pipeline is arranged in the pressurizing end, the back side of the press wheel is connected with the inlet pipe through the balancing pipeline, and high-pressure gas on the back side of the press wheel is led into the inlet pipe. The balance pipeline introduces high-pressure gas in the back side into the inlet pipe, and the pressure difference change of the two sides of the press wheel enables the press wheel to reset.

Description

Technical Field

[0001] The utility model relates to the technical field of expanders, in particular to an expander with balanced axial thrust. Background Art

[0002] The different sizes of the impellers at both ends of the expander rotor and the different process gas pressures lead to axial thrust. The axial force acts on the thrust surface of the bearing through the main shaft. If the axial force is too large and exceeds the bearing's load-bearing capacity, it will cause high bearing temperature, bearing wear, increased rotor vibration, and the unit cannot operate normally.

[0003] In the prior art, the thrust size is determined by setting up bearing oil film pressure monitoring, and high-pressure gas is introduced into the back side of the compressor wheel to balance the air pressure and adjust the thrust direction. In actual use, reverse thrust often occurs due to seal wear, and the high-pressure gas at the outlet of the boost end flows into the back of the wheel. When the outlet of the boost end and the back side of the compressor wheel are connected, the thrust increases, causing damage to the thrust bearing and the unit cannot operate normally.

[0004] There is an urgent need to design a structure that can more efficiently balance the reverse thrust and increase the service life of the unit. Utility Model Content

[0005] In view of the technical problems existing in the background technology, the purpose of the utility model is to provide an expander with balanced axial thrust, which can connect the back side of the compressor wheel with the inlet pipe, and the high pressure on the back side enters the inlet pipe through the balancing air pipe to release the high pressure on the back side.

[0006] In order to achieve the above purpose, the technical solution provided by the utility model is:

[0007] An expander with balanced axial thrust comprises a main shaft, an expansion end and a boosting end, wherein the expansion end is arranged at one end of the main shaft, the boosting end is arranged at the other end of the main shaft, an expansion wheel is arranged in the expansion end, a compressor wheel is arranged in the boosting end, and the boosting end is connected to an inlet pipe; a balancing pipe is arranged in the boosting end, the balancing pipe connects the back side of the compressor wheel and the inlet pipe, and guides the high-pressure gas on the back side of the compressor wheel into the inlet pipe.

[0008] Preferably, the inlet pipe is connected to the press wheel, the press wheel is connected to the main shaft, and a bearing I is provided between the main shaft and the press wheel.

[0009] Preferably, the expansion wheel is connected to the main shaft, and a bearing II is provided between the main shaft and the expansion wheel.

[0010] Preferably, the main shaft is arranged inside the casing, and a sealing ring is arranged on the back side of the press wheel, and the sealing ring connects the press wheel and the casing.

[0011] Preferably, an oil film pressure gauge I is provided on bearing I, an oil film pressure gauge II is provided on bearing II, a valve is connected to the balance pipeline, and the valve and oil film pressure gauge I and oil film pressure gauge II are connected through a control system.

[0012] The utility model has the following advantages and beneficial effects:

[0013] 1. In the utility model, the balance pipe connects the inlet pipe and the back side of the compressor wheel. When the high-pressure gas generates thrust on the compressor wheel, the balance pipe introduces the high-pressure gas on the back side into the inlet pipe, and the air pressure on the back side is reduced, so that the compressor wheel is reset.

[0014] 2. In the utility model, the control system is connected between the valve and the oil film pressure gauge I and the oil film pressure gauge II. The oil film pressure gauge I and the oil film pressure gauge II are used to monitor the size and direction of the thrust, and timely judge and control the opening and closing of the valve.

[0015] 3. In the utility model, the device is simple to manufacture and install, has low use and maintenance costs, and a long service life. The method of changing the pressure on the back side of the press wheel and adjusting the axial force ensures the safe and stable operation of the unit. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 A complete cross-sectional view of an expander with balanced axial thrust provided by the utility model;

[0017] Figure 2 A cross-sectional view of the booster end of the expander for balancing the axial thrust provided by the utility model;

[0018] Figure 3 A schematic diagram of high-pressure gas flow in an expander with balanced axial thrust provided by the utility model;

[0019] Icons: 1-main shaft, 2-press wheel, 21-bearing Ⅰ, 22-oil film pressure gauge Ⅰ, 23-inlet pipe, 25-back side, 3-sealing ring, 5-expansion wheel, 51-bearing Ⅱ, 52-oil film pressure gauge Ⅱ, 6-casing, 7-balance pipe, 8-valve. DETAILED DESCRIPTION

[0020] In order to make the purpose, technical solutions and advantages of the embodiments of the utility model clearer, the technical solutions in the embodiments of the utility model will be clearly and completely described below in conjunction with the drawings in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments.

[0021] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the present invention to be protected, but merely represents selected embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0022] Example

[0023] An expander with balanced axial thrust comprises a main shaft 1, an expansion end and a boosting end, characterized in that the expansion end is arranged at one end of the main shaft 1, the boosting end is arranged at the other end of the main shaft 1, an expansion wheel 5 is arranged in the expansion end, a compressor wheel 2 is arranged in the boosting end, and the boosting end is connected to an inlet pipe 23; a balancing pipe 7 is arranged in the boosting end, the balancing pipe 7 connects the back side 25 of the compressor wheel 2 and the inlet pipe 23, and guides the high-pressure gas on the back side of the compressor wheel 2 into the inlet pipe 23.

[0024] As a preferred embodiment of the present invention, specifically:

[0025] like Figure 1 , 2 As shown in Figure 3, a housing 6 is arranged on the outside of the main shaft 1, the boost end is on the right side of the main shaft 1, and bearing I21, sealing ring 3, press wheel 2 and inlet pipe 23 are installed in sequence, bearing I21 is close to the right side of the main shaft 1, and is close to the same side of the main shaft 1 as the sealing ring 3, the back side of the press wheel 2 is close to the sealing ring 3, the press wheel 2 and the main shaft 1 are connected, the main shaft 1, bearing I21, sealing ring 3, press wheel 2 and inlet pipe 23 are close to the housing 6, and the expansion end is at On the left side of the main shaft 1, bearing II 51, sealing ring 3 and expansion wheel 5 are installed in sequence, bearing II 51 is close to the left side of the main shaft 1, the back side of the expansion wheel 5 is close to the sealing ring 3, the expansion wheel 5 and the main shaft 1 are connected by threads, the main shaft 1, bearing II 51, sealing ring 3, expansion wheel 5 and casing 6 are close, the axial force of the press wheel 2 is designed to be positive thrust to the left (direction A in the figure), the positive thrust acts on the bearing II 51, and is within the thrust bearing range of the bearing II 51.

[0026] like Figure 1 , 2As shown in Figures 3 and 4, one end of the balancing pipe 7 is connected to the back side 25 of the compressor wheel 2, and the other end is connected to the inlet pipe 23. An oil film pressure gauge I22 is provided on the bearing I21, and an oil film pressure gauge II52 is provided on the bearing II51. A valve 8 is connected to the balancing pipe 7, and a control system is connected between the valve 8 and the oil film pressure gauges I22 and II52. When the oil film pressure gauge I22 has a large change, it means that the high-pressure gas has applied a reverse thrust to the bearing I21 (direction B as shown in the figure). At this time, the valve 8 is opened, and the high-pressure gas on the back side 25 flows into the inlet pipe 23 through the balancing pipe 7. At this time, the high-pressure air in the back side 25 is depressurized, and the pressure difference on both sides of the compressor wheel 2 causes the compressor wheel 2 to return to its original position.

[0027] Working principle: When running for a long time, gas leaks to the back side 25 of the compressor wheel 2, increasing the pressure, increasing the effective area of ​​the high-pressure gas, and the thrust begins to change to the right. At this time, the thrust begins to act on the bearing Ⅰ21. If the pressure continues to increase, the excessive thrust will cause the bearing oil film pressure to be excessive. After the pressure reaches a certain value, the oil film pressure gauge Ⅰ22 control system receives the signal and controls the valve 8 to open. The high-pressure gas on the back side of the compressor wheel is discharged to the inlet pipe 23 (direction C in the figure), thereby reducing the force of the compressor wheel 2 and reducing the axial force.

[0028] The above are only preferred embodiments of the present invention and are not intended to limit the present invention. For those skilled in the art, the present invention may be subject to various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. An expander with balanced axial thrust, comprising a main shaft, an expansion end and a boost end, characterized in that: The expansion end is arranged at one end of the main shaft, the boost end is arranged at the other end of the main shaft, an expansion wheel is arranged in the expansion end, a compressor wheel is arranged in the boost end, and the boost end is connected to an inlet pipe; A balancing pipe is arranged in the boosting end, and the balancing pipe connects the back side of the compressor wheel and the inlet pipe, and guides the high-pressure gas on the back side of the compressor wheel into the inlet pipe.

2. The expander with balanced axial thrust according to claim 1, characterized in that: The inlet pipe is connected to the press wheel, the press wheel is connected to the main shaft, and a bearing I is arranged between the main shaft and the press wheel.

3. The expander with balanced axial thrust according to claim 2, characterized in that: The expansion wheel is connected to the main shaft, and a bearing II is arranged between the main shaft and the expansion wheel.

4. The expander with balanced axial thrust according to claim 3, characterized in that: The main shaft is arranged inside the casing, and a sealing ring is arranged on the back side of the press wheel, and the sealing ring connects the press wheel and the casing.

5. The expander with balanced axial thrust according to claim 4, characterized in that: The bearing I is provided with an oil film pressure gauge I, the bearing II is provided with an oil film pressure gauge II, the balance pipeline is connected with a valve, and the valve and the oil film pressure gauge I and the oil film pressure gauge II are connected through a control system.

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