Electromagnetic braking turbo expander

Abstract

The invention discloses an electromagnetic braking turbo expander. The turbo expander comprises an expander body, a sealing mechanism and a braking device. The expansion machine comprises a first shell and an impeller, the first shell is provided with an air inlet hole and an air outlet hole and defines a containing space, the impeller defines a plurality of driving gaps, and the driving gaps are communicated between the containing space and the air outlet hole; the sealing mechanism comprises a first sealing piece and a second sealing piece, the first sealing piece and the second sealing piece are arranged in the first shell in a spaced mode, the driving gap is located between the first sealing piece and the second sealing piece, the first sealing piece is provided with a plurality of spaced first sealing parts, and a first sealing gap is defined between every two first sealing parts; the first sealing part and the impeller are arranged in a spaced mode, and gas in the containing space enters the first sealing gap, so that the first sealing part and the impeller are arranged in a sealed mode, and the second sealing part and the impeller are arranged in a sealed mode. A sealing gas film is formed by guiding gas to replace contact type sealing, and abrasion of sealing parts is avoided.

Description

Technical Field

[0001] This application relates to the field of turboexpanders, and particularly to a turboexpander with electromagnetic braking. Background Art

[0002] In the related art, during the operation of a turboexpander, gas enters the expander and is accelerated by a nozzle and acts on the impeller to drive the impeller to rotate. To prevent the gas from leaking from the edge of the impeller to the non-working area without complete expansion and work, a sealing structure needs to be provided at both ends of the impeller. However, most traditional sealing structures use single-stage static seals or contact dynamic seals. When the impeller rotates at high speed, the sealing structure is prone to wear, and gas leakage is likely to occur during long-term operation, reducing the sealing performance of the expander and causing energy loss of the expander. Summary of the Invention

[0003] In order to prevent wear of the sealing structure, improve the sealing performance of the expander, and reduce the energy loss of the expander, this application provides a turboexpander with electromagnetic braking.

[0004] A turboexpander with electromagnetic braking provided by this application adopts the following technical solutions: A turboexpander with electromagnetic braking includes: an expander, the expander includes a first housing and an impeller, the first housing is provided with an air inlet hole, an air outlet hole and defines a receiving space, the impeller is pivotally installed in the first housing, the impeller defines a plurality of driving gaps, and the plurality of driving gaps are spaced apart along the circumferential direction of the impeller. The receiving space is communicated with the air inlet hole, and the driving gaps are communicated between the receiving space and the air outlet hole. The impeller is adapted to be driven to rotate by gas.

[0005] A sealing mechanism, the sealing mechanism includes a first seal and a second seal. Both the first seal and the second seal are arranged in the first housing. Along the axial direction of the impeller, the first seal and the second seal are spaced apart and both are located outside the impeller. The driving gaps are located between the first seal and the second seal. The first seal is located on the side of the impeller close to the air outlet hole. The end wall of the first seal close to the impeller is provided with a plurality of first sealing portions, and the plurality of first sealing portions are spaced apart along the axial direction of the impeller. A first sealing gap is defined between any two adjacent first sealing portions. The first sealing portion is spaced apart from the impeller. The gas in the receiving space is adapted to enter the first sealing gap so that the first seal and the impeller are sealed, and the second seal and the impeller are sealed.

[0006] A braking device, which is connected and cooperated with the impeller, and is used to brake and adjust the rotational speed of the impeller.

[0007] By adopting the above technical solution, by providing a plurality of first sealing portions on the first seal, and defining a first sealing gap between any two adjacent first sealing portions, when the gas in the accommodation space flows into the first sealing gap, the gas in the first sealing gap forms an annular gas film between the first seal and the impeller, and the sealed gas film blocks the gas in the accommodation space from passing through the gap between the first seal and the impeller, thereby realizing non-contact sealing between the first seal and the impeller. Compared with the prior art, by guiding the gas to form a stable sealed gas film instead of the traditional contact sealing method, while ensuring the sealing performance, the wear of the sealing components during the high-speed rotation of the impeller is avoided, thereby improving the sealing reliability of the turboexpander.

[0008] Preferably, along the direction from the outside to the inside of the first seal, the end wall of the first sealing portion close to the air outlet hole is inclined towards the impeller.

[0009] By adopting the above technical solution, when the gas flows to the position of the end wall of the first sealing portion close to the air outlet hole, the gas is deflected by the end wall of the first sealing portion close to the air outlet hole and moves close to the gap between the first sealing portion and the impeller. When the gas in the first sealing gap moves to the gap between the first sealing portion and the impeller, the gas in the first sealing gap blocks the gas in the accommodation space from passing through the gap between the first seal and the impeller, thereby establishing a stable non-contact sealing structure between the first sealing portion and the impeller, and further improving the sealing reliability of the turboexpander.

[0010] Preferably, the end wall of the second seal close to the impeller is provided with a plurality of second sealing portions, the plurality of second sealing portions are spaced apart along the axial direction of the impeller, the second sealing portion is spaced apart from the impeller, and a second sealing gap is defined between any two adjacent second sealing portions, and the gas in the accommodation space is adapted to enter the second sealing gap to seal the second seal and the impeller.

[0011] By adopting the above technical solution, after the gas enters the second sealing gap, the gas makes a circular motion in the second sealing gap to form an annular gas film acting between the second seal and the impeller, and the annular gas film is used to continuously block the gas in the accommodation space from passing through the gap between the second seal and the impeller, thereby preventing the gas in the accommodation space from leaking to the non-working area before completing the expansion work, and further improving the sealing performance of the turboexpander.

[0012] Preferably, the braking device includes a second housing, a braking shaft, and a braking member. The second housing is connected and cooperated with the first housing. The second housing defines an installation space communicating with the accommodation space. Both the braking shaft and the braking member are disposed within the second housing. The braking shaft is pivotally connected to the second housing, and the braking shaft extends into the first housing and is connected and cooperated with the impeller. The braking shaft is provided with a magnetic member, the braking member forms a magnetic field, the braking shaft is located within the magnetic field, and the electromagnetic force received by the braking shaft serves as the braking force. The braking member is used to brake the braking shaft.

[0013] By adopting the above technical solution, an electromagnetic interaction is formed between the magnetic member on the braking shaft and the braking member, and the braking member applies an electromagnetic force to the braking shaft to brake the impeller, thereby avoiding the problem that the impeller may suffer from structural fatigue or damage due to excessive rotational speed during high-speed operation, and further improving the operation safety and stability of the turboexpander under high-pressure and high-speed conditions.

[0014] Preferably, the sealing mechanism further includes a third sealing member and a fourth sealing member. Both the third sealing member and the fourth sealing member are disposed within the first housing. The third sealing member and the fourth sealing member are spaced apart along the axial direction of the braking shaft. The fourth sealing member is located on the side of the third sealing member away from the impeller. Both the third sealing member and the fourth sealing member are sleeved on the outer side of the braking shaft, and both the third sealing member and the fourth sealing member are relatively and sealingly disposed with respect to the braking shaft.

[0015] By adopting the above technical solution, the third sealing member performs primary sealing on the braking shaft, and the fourth sealing member performs secondary sealing on the braking shaft. The gas is blocked by both the third sealing member and the fourth sealing member, thereby minimizing the possibility of gas passing through the gaps between the third sealing member and the braking shaft and between the fourth sealing member and the braking shaft, and further preventing the gas within the accommodation space from flowing out to the external environment through the second housing.

[0016] Preferably, the third sealing member is spaced apart from the braking shaft. A first sealing groove is annularly provided on the end wall of the third sealing member close to the braking shaft. Gas is adapted to enter the first sealing groove to enable a sealed arrangement between the third sealing member and the braking shaft. The air pressure of the gas within the first sealing groove is higher than the air pressure of the gas within the accommodation space.

[0017] By adopting the above technical solution, under the action of the gas pressure difference, the gas within the first sealing groove flows towards the gap between the third sealing member and the braking shaft and forms a stable sealing gas film, thereby blocking the gas within the accommodation space from leaking to the outside through the gap between the third sealing member and the braking shaft, and further improving the sealing performance and sealing reliability of the expander.

[0018] Preferably, the fourth seal is spaced apart from the brake shaft, and a second sealing groove is provided on the end wall ring of the fourth seal close to the brake shaft, and gas is suitable for entering the second sealing groove to seal the fourth seal and the brake shaft, and the gas pressure in the second sealing groove is higher than the gas pressure in the first sealing groove.

[0019] By adopting the above technical solution, under the action of the gas pressure difference, the gas in the second sealing groove flows to the gap between the fourth seal and the brake shaft and forms a stable sealing gas film, thereby preventing the gas between the third seal and the fourth seal from leaking to the outside through the gap between the fourth seal and the brake shaft, thereby improving the sealing performance and sealing reliability of the expander.

[0020] Preferably, a counterweight plate is provided at the end of the brake shaft away from the impeller, and the counterweight plate is provided with a plurality of counterweight holes, and the plurality of counterweight holes are spaced apart along the circumferential direction of the counterweight plate, and the counterweight holes are used to accommodate one or more counterweight blocks, and the counterweight plate is used to adjust the dynamic balance of the brake shaft.

[0021] By adopting the above technical solution, a counterweight block is installed in one or more counterweight holes of the counterweight plate according to the eccentricity or vibration condition of the brake shaft in the rotating state. The counterweight block forms a reverse torque to offset the centrifugal unbalance force, thereby reducing the vibration deviation generated by the brake shaft during high-speed rotation, and further improving the stability of the brake shaft rotation and the dynamic balance accuracy.

[0022] Preferably, the second shell is provided with a liquid inlet, a liquid outlet and a heat dissipation pipe, the heat dissipation pipe is wound around the outer peripheral wall of the brake part and the outer peripheral wall of the brake shaft, one end of the heat dissipation pipe is connected to the liquid inlet, and the other end is connected to the liquid outlet, and a cooling medium flows in the heat dissipation pipe.

[0023] By adopting the above technical solution, the cooling medium exchanges heat with both the brake part and the brake shaft. The cooling medium absorbs the heat generated by the brake part and the heat generated by the brake shaft to maintain the temperature of the brake part and the temperature of the brake shaft within a preset temperature range. The cooling medium in the heat dissipation pipeline flows out of the cooling pipeline through the liquid outlet.

[0024] Preferably, the impeller has a plurality of blades, and the plurality of blades are spaced apart along the circumferential direction of the impeller, and the driving gap is defined between any two adjacent blades, and the gas is suitable for driving the blades to drive the impeller to rotate.

[0025] By adopting the above technical solution, the gas collides with the side wall of the blade, and the gas pushes the blade to drive the impeller to rotate. Under the combined action of the forces on multiple blades, the impeller is driven to rotate by the gas, and the rotation of the impeller realizes the expansion work process of the gas.

[0026] In summary, the present application includes at least one of the following beneficial technical effects: 1. By providing a plurality of first sealing portions on the first seal, and defining a first sealing gap between any two adjacent first sealing portions, when the gas in the accommodation space flows into the first sealing gap, the gas in the first sealing gap forms an annular gas film between the first seal and the impeller. The sealed gas film blocks the gas in the accommodation space from passing through the gap between the first seal and the impeller, thereby achieving non-contact sealing between the first seal and the impeller. Compared with the prior art, by guiding the gas to form a stable sealed gas film instead of the traditional contact sealing method, while ensuring the sealing performance, the wear of the sealing components during the high-speed rotation of the impeller is avoided, thereby improving the sealing reliability of the turboexpander; 2. Under the action of the gas pressure difference, the gas in the first sealing groove flows towards the gap between the third seal and the braking shaft and forms a stable sealed gas film, thereby blocking the gas in the accommodation space from leaking to the outside through the gap between the third seal and the braking shaft, and further improving the sealing performance and sealing reliability of the expander; 3. By installing counterweight blocks in one or more counterweight holes of the counterweight disk according to the eccentricity or vibration condition of the braking shaft during rotation, the counterweight blocks form a reverse torque for offsetting the centrifugal unbalance force, thereby reducing the vibration deviation generated by the braking shaft during high-speed rotation, and further improving the rotation stability and dynamic balance accuracy of the braking shaft. Description of the Drawings

[0027] Figure 1 is a schematic diagram of a turboexpander with electromagnetic braking according to an embodiment of the present application; Figure 2 is a cross-sectional view of a turboexpander with electromagnetic braking according to an embodiment of the present application; Figure 3 is Figure 2 an enlarged schematic view of part A in Figure 4 is Figure 2 an enlarged schematic view of part B in Figure 5 is Figure 2 an enlarged schematic view of part C in Figure 6 is a cross-sectional view of the impeller according to an embodiment of the present application.

[0028] Description of the Reference Numerals: 100, Turbine expander with electromagnetic braking; 1. Expander; 11. First housing; 111. Air inlet hole; 112. Air outlet hole; 113. Accommodating space; 12. Impeller; 121. Driving gap; 122. Blade; 2. Sealing mechanism; 21. First seal; 211. First sealing part; 212. First sealing gap; 22. Second seal; 221. Second sealing part; 222. Second sealing gap; 23. Third seal; 231. First sealing groove; 24. Fourth seal; 241. Second sealing groove; 3. Braking device; 31. Second housing; 311. Installation space; 312. Liquid inlet hole; 313. Liquid outlet hole; 32. Braking shaft; 321. Magnetic part; 322. Counterweight disk; 3221. Counterweight hole; 33. Braking part. Detailed implementation mode

[0029] The following will further describe this application in detail with reference to the attached Figures 1-6 drawings.

[0030] An embodiment of this application discloses a turbine expander 100 with electromagnetic braking.

[0031] Referring to Figures 1-3 , the turbine expander 100 with electromagnetic braking according to the embodiment of this application includes: an expander 1, a sealing mechanism 2, and a braking device 3.

[0032] The expander 1 includes a first housing 11 and an impeller 12. The first housing 11 is provided with an air inlet hole 111, an air outlet hole 112, and defines an accommodating space 113. The impeller 12 is pivotally installed in the first housing 11. The impeller 12 defines a plurality of driving gaps 121. The plurality of driving gaps 121 are spaced apart along the circumferential direction of the impeller 12. The accommodating space 113 communicates with the air inlet hole 111. The driving gap 121 communicates between the accommodating space 113 and the air outlet hole 112. The impeller 12 is adapted to be driven to rotate by gas.

[0033] Specifically, gas enters the accommodating space 113 through the air inlet hole 111. The gas in the accommodating space 113 flows into the driving gap 121. And during the process that the gas in the accommodating space 113 flows into the driving gap 121, the gas drives the impeller 12 to rotate, and the gas in the driving gap 121 flows into the air outlet hole 112.

[0034] The sealing mechanism 2 includes a first seal 21 and a second seal 22. Both the first seal 21 and the second seal 22 are arranged inside the first housing 11. Along the axial direction of the impeller 12, the first seal 21 and the second seal 22 are arranged at intervals and are both located outside the impeller 12. Specifically, both the first seal 21 and the second seal 22 are annularly arranged outside the impeller 12. The driving gap 121 is located between the first seal 21 and the second seal 22. The first seal 21 is located on the side of the impeller 12 close to the air outlet 112, and the second seal 22 is located on the side of the impeller 12 away from the air outlet 112.

[0035] Moreover, a plurality of first sealing portions 211 are provided on the end wall of the first seal 21 close to the impeller 12. The plurality of first sealing portions 211 are all arranged opposite to the outer peripheral wall of the impeller 12. The plurality of first sealing portions 211 are arranged at intervals along the axial direction of the impeller 12. An adjacent two of the plurality of first sealing portions 211 define a first sealing gap 212 therebetween. The first sealing portion 211 is arranged at an interval from the impeller 12. The gas in the accommodation space 113 is adapted to enter into the first sealing gap 212, so that the first seal 21 and the impeller 12 are hermetically arranged, and the second seal 22 and the impeller 12 are hermetically arranged.

[0036] Specifically, along the axial direction of the impeller 12, the gas in the accommodation space 113 sequentially flows into the plurality of first sealing gaps 212. The gas in the first sealing gap 212 close to the air outlet 112 among the plurality of first sealing gaps 212 flows into the air outlet 112. After the gas enters the first sealing gap 212, the gas in the first sealing gap 212 forms an annular gas film acting between the first seal 21 and the impeller 12. The annular gas film is used to block the gas in the accommodation space 113 from passing through the gap between the first seal 21 and the impeller 12, so that the first seal 21 and the impeller 12 are hermetically arranged.

[0037] It should be noted that when the gas enters the first sealing gap 212, the gas collides with the first sealing portion 211 close to the air outlet 112 in the first sealing gap 212, and under the continuous pushing action of the gas in the accommodation space 113, along the height direction of the expander 1, the height direction of the expander 1 can refer to Figure 2In the up and down direction, the gas in the first sealing gap 212 moves upward, then the gas in the first sealing gap 212 collides with the bottom wall of the first sealing gap 212, and the gas in the first sealing gap 212 moves in a direction away from the air outlet 112. The gas in the first sealing gap 212 collides with the first sealing portion 211 in the first sealing gap 212 that is far from the air outlet 112, and the gas in the first sealing gap 212 moves downward. When the gas in the first sealing gap 212 moves to be opposite to the gap between the first sealing portion 211 and the impeller 12, the gas in the accommodation space 113 pushes the gas in the first sealing gap 212 to move close to the air outlet 112, so that the gas in the first sealing gap 212 makes a circular motion in the first sealing gap 212, and an annular gas film is formed by the gas in the first sealing gap 212.

[0038] The gas deflects along the circumferential direction of the first sealing gap 212 and continuously makes a circular motion around the impeller 12 in the first sealing gap 212 defined between multiple first sealing portions 211. As the gas is continuously pushed in and circulates in the gap, an annular gas film covering the entire gap path is gradually formed between the first seal 21 and the impeller 12.

[0039] The braking device 3 is connected and cooperates with the impeller 12. The braking device 3 is used to brake and adjust the rotation speed of the impeller 12. Specifically, when the rotation speed of the impeller 12 is higher than the preset rotation speed, the braking device 3 brakes the impeller 12 to reduce the rotation speed of the impeller 12, so as to prevent damage to the structure of the impeller 12 caused by too fast rotation speed of the impeller 12.

[0040] Thus, by providing multiple first sealing portions 211 on the first seal 21, and a first sealing gap 212 is defined between any two adjacent first sealing portions 211. When the gas in the accommodation space 113 flows into the first sealing gap 212, an annular gas film is formed between the first seal 21 and the impeller 12 by the gas in the first sealing gap 212. The sealed gas film blocks the gas in the accommodation space 113 from passing through the gap between the first seal 21 and the impeller 12, thereby realizing non-contact sealing between the first seal 21 and the impeller 12. Compared with the prior art, by guiding the gas to form a stable sealed gas film instead of the traditional contact sealing method, while ensuring the sealing performance, the wear of the sealing components during the high-speed rotation of the impeller 12 is avoided, thereby improving the sealing reliability of the turboexpander 1.

[0041] Refer to Figure 3, in some embodiments of the present application, along the direction from outside to inside of the first seal 21, the end wall of the first seal portion 211 close to the air outlet hole 112 is inclined towards the impeller 12. Specifically, along the height direction of the expander 1, the lower end portion of the end wall of the first seal portion 211 close to the air outlet hole 112 is inclined towards the impeller 12.

[0042] After the gas in the accommodation space 113 enters the first seal gap 212, the gas in the first seal gap 212 continuously rotates to form an annular gas film. When the gas in the first seal gap 212 flows to the position of the end wall of the first seal portion 211 close to the air outlet hole 112, the gas in the first seal gap 212 is deflected by the end wall of the first seal portion 211 close to the air outlet hole 112, and the gas in the first seal gap 212 moves along the end wall of the first seal portion 211 close to the air outlet hole 112 towards the gap between the first seal portion 211 and the impeller 12. When the gas in the first seal gap 212 moves to the gap between the first seal portion 211 and the impeller 12, the gas in the first seal gap 212 blocks the gas in the accommodation space 113 from passing through the gap between the first seal 21 and the impeller 12.

[0043] When the gas flows to the position of the end wall of the first seal portion 211 close to the air outlet hole 112, the gas is deflected by the end wall of the first seal portion 211 close to the air outlet hole 112 and moves towards the gap between the first seal portion 211 and the impeller 12. When the gas in the first seal gap 212 moves to the gap between the first seal portion 211 and the impeller 12, the gas in the first seal gap 212 blocks the gas in the accommodation space 113 from passing through the gap between the first seal 21 and the impeller 12, so that a stable non-contact seal structure can be established between the first seal portion 211 and the impeller 12, and further the seal reliability of the turbine expander 1 can be improved.

[0044] Refer to Figure 2 and Figure 3 , in some embodiments of the present application, the second seal 22 is located on the side of the impeller 12 away from the air outlet hole 112. The end wall of the second seal 22 close to the impeller 12 is provided with a plurality of second seal portions 221. The plurality of second seal portions 221 are all opposite to the outer peripheral wall of the impeller 12. The plurality of second seal portions 221 are arranged at intervals along the axial direction of the impeller 12. The second seal portion 221 is arranged at an interval from the impeller 12. Any two adjacent second seal portions 221 define a second seal gap 222. The gas in the accommodation space 113 is adapted to enter the second seal gap 222 so that the second seal 22 and the impeller 12 are hermetically arranged.

[0045] In the axial direction of the impeller 12, the gas in the accommodation space 113 sequentially flows into a plurality of second sealing gaps 222. After the gas enters the second sealing gaps 222, the gas makes a circular motion in the second sealing gaps 222 to form an annular gas film acting between the second seal 22 and the impeller 12. The annular gas film is used to block the gas in the accommodation space 113 from passing through the gap between the second seal 22 and the impeller 12, so that the second seal 22 and the impeller 12 are sealed.

[0046] It should be noted that after the gas enters the second sealing gap 222, the gas collides with the second sealing portion 221 away from the impeller 12 in the second sealing gap 222, and under the continuous pushing action of the gas in the accommodation space 113, in the height direction of the expander 1, the gas in the second sealing gap 222 moves upward, and then the gas in the second sealing gap 222 collides with the bottom wall of the second sealing gap 222. The gas in the second sealing gap 222 moves in the direction close to the impeller 12, the gas in the second sealing gap 222 collides with the second sealing portion 221 close to the impeller 12 in the second sealing gap 222, and the gas in the second sealing gap 222 moves downward. When the gas in the second sealing gap 222 moves to be opposite to the gap between the second sealing portion 221 and the impeller 12, the gas in the accommodation space 113 pushes the gas in the second sealing gap 222 to move away from the impeller 12, so that the gas in the second sealing gap 222 makes a circular motion in the second sealing gap 222, and an annular gas film is formed by the gas in the second sealing gap 222.

[0047] After the gas enters the second sealing gap 222, the gas makes a circular motion in the second sealing gap 222 to form an annular gas film acting between the second seal 22 and the impeller 12. The annular gas film is used to continuously block the gas in the accommodation space 113 from passing through the gap between the second seal 22 and the impeller 12, so as to prevent the gas in the accommodation space 113 from leaking to the non-working area before completing the expansion work, and thus the sealing performance of the turbine expander 1 can be improved.

[0048] Refer to Figure 1 and Figure 2, in some embodiments of the present application, the braking device 3 includes a second housing 31, a braking shaft 32, and a braking member 33. The second housing 31 is connected and cooperated with the first housing 11. The second housing 31 is located on the side of the impeller 12 away from the air outlet 112. The second housing 31 defines an installation space 311 communicating with the accommodation space 113. Both the braking shaft 32 and the braking member 33 are arranged inside the second housing 31. The braking member 33 is sleeved outside the braking shaft 32. The braking shaft 32 is pivotally connected to the second housing 31, and the braking shaft 32 extends into the first housing 11 and is connected and cooperated with the impeller 12. The braking shaft 32 is located on the side of the impeller 12 away from the air outlet 112. The braking shaft 32 is provided with a magnetic member 321. The braking member 33 forms a magnetic field, and the braking shaft 32 is located in the magnetic field. The electromagnetic force received by the braking shaft 32 serves as the braking force, and the braking member 33 is used to brake the braking shaft 32.

[0049] In some specific embodiments, the braking member 33 may be an electromagnetic induction coil, but the present application is not limited thereto. The braking member 33 may also be a linear armature.

[0050] The gas in the accommodation space 113 drives the impeller 12 to rotate. The impeller 12 drives the braking shaft 32 to rotate. When the braking shaft 32 rotates, an electromagnetic interaction is formed between the magnetic member 321 on the braking shaft 32 and the braking member 33. The braking member 33 exerts an electromagnetic force on the braking shaft 32 through the electromagnetic interaction to brake the braking shaft 32, thereby preventing the rotation speed of the impeller 12 from being greater than the preset rotation speed.

[0051] Through the electromagnetic interaction formed between the magnetic member 321 on the braking shaft 32 and the braking member 33, the braking member 33 exerts an electromagnetic force on the braking shaft 32 to brake the impeller 12, thereby avoiding the problems of structural fatigue or damage caused by excessive rotation speed during the high-speed operation of the impeller 12, and further improving the operation safety and stability of the turboexpander 1 under high-pressure and high-speed conditions.

[0052] Further, the braking member 33 or the braking shaft 32 may be electrically connected to the power storage member. When the braking shaft 32 rotates, the magnetic member 321 on the braking shaft 32 cuts the magnetic field formed by the braking member 33, and an induced electromotive force is formed between the braking shaft 32 and the braking member. The current on the braking member 33 or the braking shaft 32 flows into the power storage member, and the power storage member stores electrical energy.

[0053] In some specific embodiments, the power storage member may be a battery or the like.

[0054] Refer to Figure 2 and Figure 4, in some embodiments of the present application, the sealing mechanism 2 further includes a third seal 23 and a fourth seal 24. Both the third seal 23 and the fourth seal 24 are disposed within the first housing 11. The third seal 23 and the fourth seal 24 are spaced apart along the axial direction of the brake shaft 32. The fourth seal 24 is located on the side of the third seal 23 away from the impeller 12. Both the third seal 23 and the fourth seal 24 are sleeved outside the brake shaft 32, and both the third seal 23 and the fourth seal 24 are opposite to and sealed with the brake shaft 32.

[0055] When the gas in the accommodation space 113 flows towards the installation space 311 and reaches the third seal 23 and the fourth seal 24, the third seal 23 performs a primary seal on the brake shaft 32, and the fourth seal 24 performs a secondary seal on the brake shaft 32. The gas is jointly blocked by the third seal 23 and the fourth seal 24, thereby minimizing the possibility of gas passing through the gaps between the third seal 23 and the brake shaft 32 and between the fourth seal 24 and the brake shaft 32. Further, it can prevent the gas in the accommodation space 113 from flowing out to the external environment through the second housing 31.

[0056] Refer to Figure 2 and Figure 4 , in some embodiments of the present application, the third seal 23 is spaced apart from the brake shaft 32. A first seal groove 231 is annularly provided on the end wall of the third seal 23 close to the brake shaft 32. Gas is adapted to enter the first seal groove 231 to enable a sealed arrangement between the third seal 23 and the brake shaft 32. The air pressure of the gas in the first seal groove 231 is higher than the air pressure of the gas in the accommodation space 113.

[0057] In some specific embodiments, the first seal groove 231 can be connected to an air pump, and the air pump is used to convey gas into the first seal groove 231.

[0058] Gas enters the first seal groove 231 to fill the first seal groove 231. The air pressure of the gas in the first seal groove 231 is higher than the air pressure of the gas in the accommodation space 113. Under the action of the gas pressure difference, the gas in the first seal groove 231 flows towards the gap between the third seal 23 and the brake shaft 32. The gas in the first seal groove 231 fills the gap between the third seal 23 and the brake shaft 32 and forms a stable sealing gas film, and the sealing gas film blocks the gas in the accommodation space 113 from passing through the gap between the third seal 23 and the brake shaft 32.

[0059] Under the action of the gas pressure difference, the gas in the first sealing groove 231 flows into the gap between the third seal 23 and the brake shaft 32 and forms a stable sealing gas film, so as to prevent the gas in the accommodation space 113 from leaking to the outside through the gap between the third seal 23 and the brake shaft 32, thereby improving the sealing performance and reliability of the expander 1.

[0060] Referring to Figure 2 and Figure 4 , in some embodiments of the present application, the fourth seal 24 is spaced apart from the brake shaft 32, and a second sealing groove 241 is provided around the end wall of the fourth seal 24 close to the brake shaft 32. The gas is adapted to enter the second sealing groove 241 so that the fourth seal 24 and the brake shaft 32 are sealed, and the air pressure of the gas in the second sealing groove 241 is higher than the air pressure of the gas in the first sealing groove 231.

[0061] In some specific embodiments, the second sealing groove 241 may be communicated with an air pump, and the air pump is used to convey gas into the second sealing groove 241.

[0062] The gas enters the second sealing groove 241 to fill the second sealing groove 241. The air pressure of the gas in the second sealing groove 241 is higher than the air pressure of the gas in the first sealing groove 231. Under the action of the gas pressure difference, the gas in the second sealing groove 241 flows into the gap between the fourth seal 24 and the brake shaft 32. The gas in the second sealing groove 241 fills the gap between the fourth seal 24 and the brake shaft 32 and forms a stable sealing gas film, and the sealing gas film blocks the gas between the third seal 23 and the fourth seal 24 from passing through the gap between the fourth seal 24 and the brake shaft 32.

[0063] Under the action of the gas pressure difference, the gas in the second sealing groove 241 flows into the gap between the fourth seal 24 and the brake shaft 32 and forms a stable sealing gas film, so as to prevent the gas between the third seal 23 and the fourth seal 24 from leaking to the outside through the gap between the fourth seal 24 and the brake shaft 32, thereby improving the sealing performance and reliability of the expander 1.

[0064] Referring to Figure 2 and Figure 5 , in some embodiments of the present application, a counterweight disc 322 is provided at the end of the brake shaft 32 away from the impeller 12. The counterweight disc 322 is provided with a plurality of counterweight holes 3221, and the plurality of counterweight holes 3221 are spaced apart along the circumferential direction of the counterweight disc 322. The counterweight holes 3221 are used to accommodate one or more counterweight blocks, and the counterweight disc 322 is used to adjust the dynamic balance of the brake shaft 32.

[0065] During the rotation of the brake shaft 32 driven by the impeller 12, by measuring the eccentricity or vibration condition of the brake shaft 32 in the rotating state, the mass unbalance region of the brake shaft 32 in a certain angular direction is determined, and according to the position of the unbalance region and the mass to be compensated, a counterweight is installed in the corresponding counterweight hole 3221. The counterweight disk 322 forms a reverse moment on the brake shaft 32 through the position distribution and mass adjustment of the counterweight, so as to compensate for the centrifugal unbalance force generated during the rotation of the brake shaft 32 and achieve the dynamic balance adjustment of the rotation of the brake shaft 32.

[0066] By installing a counterweight in one or more counterweight holes 3221 of the counterweight disk 322 according to the eccentricity or vibration condition of the brake shaft 32 in the rotating state, the counterweight forms a reverse moment for offsetting the centrifugal unbalance force, thereby reducing the vibration deviation generated during the high-speed rotation of the brake shaft 32, and further improving the rotation stability and dynamic balance accuracy of the brake shaft 32.

[0067] Refer to Figure 2 , in some embodiments of the present application, the second housing 31 is provided with a liquid inlet hole 312, a liquid outlet hole 313 and a heat dissipation pipeline. The heat dissipation pipeline is wound around the outer peripheral wall of the brake member 33 and the outer peripheral wall of the brake shaft 32. One end of the heat dissipation pipeline is connected and matched with the liquid inlet hole 312, and the other end of the heat dissipation pipeline is connected and matched with the liquid outlet hole 313. A cooling medium flows in the heat dissipation pipeline.

[0068] In some specific embodiments, the liquid inlet hole 312 can be communicated with a liquid delivery pump for delivering a cooling medium to the heat dissipation pipeline, and the liquid outlet hole 313 can be communicated with a storage tank for storing the cooling medium.

[0069] In some specific embodiments, the cooling medium can be liquid nitrogen.

[0070] The cooling medium enters the heat dissipation pipeline through the liquid inlet hole 312 and flows along the heat dissipation pipeline under the action of an external pumping pressure. The cooling medium flows through the outer peripheral wall of the brake member 33 and the outer peripheral wall of the brake shaft 32 in the heat dissipation pipeline. The cooling medium exchanges heat with both the brake member 33 and the brake shaft 32. The cooling medium absorbs the heat generated by the brake member 33 and the heat generated by the brake shaft 32 to maintain the temperatures of the brake member 33 and the brake shaft 32 within a preset temperature range. The cooling medium in the heat dissipation pipeline flows out of the cooling pipeline through the liquid outlet hole 313.

[0071] Refer to Figure 2 , Figure 3 and Figure 6, in some embodiments of the present application, the impeller 12 has a plurality of blades 122. The plurality of blades 122 are arranged at intervals in the circumferential direction of the impeller 12. A driving gap 121 is defined between any two adjacent blades 122. The gas is adapted to drive the blades 122 to drive the impeller 12 to rotate.

[0072] The gas enters the accommodation space 113 through the air inlet hole 111. The gas in the accommodation space 113 flows into the driving gap 121. During the process of the gas flowing in the driving gap 121, the gas collides with the side wall of the blade 122. The gas pushes the blade 122 to drive the impeller 12 to rotate. Under the combined action of the forces on the plurality of blades 122, the impeller 12 is driven to rotate by the gas. The rotation of the impeller 12 realizes the expansion work process of the gas. After the gas completes the work, it is discharged to the outside of the first housing 11 through the air outlet hole 112.

[0073] The above are all the preferred embodiments of the present application. The protection scope of the present application is not limited thereby. Therefore, all equivalent changes made according to the structure, shape, and principle of the present application shall be covered within the protection scope of the present application.

Claims

1. An electromagnetic braking turbine expander, characterized in that, Comprising: An expander (1), the expander (1) includes a first housing (11) and an impeller (12), the first housing (11) is provided with an air inlet hole (111), an air outlet hole (112) and defines a receiving space (113), the impeller (12) is pivotally installed within the first housing (11), the impeller (12) defines a plurality of driving gaps (121), the plurality of driving gaps (121) are spaced apart along the circumferential direction of the impeller (12), the receiving space (113) communicates with the air inlet hole (111), and the driving gap (121) communicates between the receiving space (113) and the air outlet hole (112), and the impeller (12) is adapted to be driven to rotate by gas; A sealing mechanism (2), the sealing mechanism (2) includes a first seal (21) and a second seal (22), both the first seal (21) and the second seal (22) are provided within the first housing (11), along the axial direction of the impeller (12), the first seal (21) and the second seal (22) are spaced apart and are both located outside the impeller (12), the driving gap (121) is located between the first seal (21) and the second seal (22), the first seal (21) is located on the side of the impeller (12) close to the air outlet hole (112), and the end wall of the first seal (21) close to the impeller (12) is provided with a plurality of first sealing portions (211), the plurality of first sealing portions (211) are spaced apart along the axial direction of the impeller (12), and a first sealing gap (212) is defined between any two adjacent first sealing portions (211), the first sealing portion (211) is spaced apart from the impeller (12), and the gas within the receiving space (113) is adapted to enter the first sealing gap (212) to seal the first seal (21) and the impeller (12), and the second seal (22) is sealed with the impeller (12); A braking device (3), the braking device (3) is connected and cooperated with the impeller (12), and the braking device (3) is used to brake and adjust the rotational speed of the impeller (12).

2. The turboexpander with electromagnetic braking according to claim 1, characterized in that, Along the direction from the outside to the inside of the first seal (21), the end wall of the first sealing portion (211) close to the air outlet hole (112) is inclined towards the impeller (12).

3. An electromagnetic braking turboexpander according to claim 1, characterized in that, The second seal (22) is provided with a plurality of second seal portions (221) near the end wall of the impeller (12). The plurality of second seal portions (221) are spaced apart along the axial direction of the impeller (12). The second seal portions (221) are spaced apart from the impeller (12). An adjacent pair of the second seal portions (221) defines a second seal gap (222). The gas in the accommodation space (113) is adapted to enter the second seal gap (222) so that the second seal (22) and the impeller (12) are hermetically arranged.

4. An electromagnetic braking turboexpander according to claim 1, characterized in that, The braking device (3) includes a second housing (31), a braking shaft (32) and a braking member (33). The second housing (31) is connected and cooperated with the first housing (11). The second housing (31) defines an installation space (311) communicating with the accommodation space (113). The braking shaft (32) and the braking member (33) are both arranged in the second housing (31). The braking shaft (32) is pivotally connected to the second housing (31), and the braking shaft (32) extends into the first housing (11) and is connected and cooperated with the impeller (12). The braking shaft (32) is provided with a magnetic member (321). The braking member (33) forms a magnetic field. The braking shaft (32) is located in the magnetic field. The electromagnetic force received by the braking shaft (32) serves as a braking force. The braking member (33) is used to brake the braking shaft (32).

5. An electromagnetic braking type turboexpander according to claim 4, wherein, The sealing mechanism (2) further includes a third seal (23) and a fourth seal (24). The third seal (23) and the fourth seal (24) are both arranged in the first housing (11). The third seal (23) and the fourth seal (24) are spaced apart along the axial direction of the braking shaft (32). The fourth seal (24) is located on the side of the third seal (23) away from the impeller (12). The third seal (23) and the fourth seal (24) are both sleeved on the outer side of the braking shaft (32). The third seal (23) and the fourth seal (24) are both opposite to and hermetically arranged with the braking shaft (32).

6. An electromagnetic braking turboexpander according to claim 5, characterized in that, The third seal (23) is spaced apart from the braking shaft (32). A first seal groove (231) is annularly arranged on the end wall of the third seal (23) close to the braking shaft (32). Gas is adapted to enter the first seal groove (231) so that the third seal (23) and the braking shaft (32) are hermetically arranged. The air pressure of the gas in the first seal groove (231) is higher than the air pressure of the gas in the accommodation space (113).

7. An expansion turbine with electromagnetic braking according to claim 6, characterized in that, The fourth seal (24) is arranged at a distance from the brake shaft (32). A second seal groove (241) is provided in an annular shape on the end wall of the fourth seal (24) close to the brake shaft (32). Gas is adapted to enter into the second seal groove (241) so that a sealed arrangement is formed between the fourth seal (24) and the brake shaft (32). The air pressure of the gas in the second seal groove (241) is higher than the air pressure of the gas in the first seal groove (231).

8. An expansion turbine with electromagnetic braking according to claim 4, characterized in that, A counterweight disk (322) is provided at the end of the brake shaft (32) away from the impeller (12). The counterweight disk (322) is provided with a plurality of counterweight holes (3221). The plurality of counterweight holes (3221) are arranged at intervals in the circumferential direction of the counterweight disk (322). The counterweight holes (3221) are used for accommodating one or more counterweight blocks. The counterweight disk (322) is used for adjusting the dynamic balance of the brake shaft (32).

9. An expansion turbine with electromagnetic braking according to claim 4, characterized in that, The second housing (31) is provided with a liquid inlet hole (312), a liquid outlet hole (313) and a heat dissipation pipeline. The heat dissipation pipeline is wound around the outer peripheral wall of the brake member (33) and the outer peripheral wall of the brake shaft (32). One end of the heat dissipation pipeline is connected and matched with the liquid inlet hole (312), and the other end is connected and matched with the liquid outlet hole (313). A cooling medium flows in the heat dissipation pipeline.

10. An electromagnetic braking turbine expander according to claim 1, characterized in that, The impeller (12) has a plurality of blades (122). The plurality of blades (122) are arranged at intervals in the circumferential direction of the impeller (12). A driving gap (121) is defined between any two adjacent blades (122). Gas is adapted to drive the blades (122) to drive the impeller (12) to rotate.

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