Electromagnetic braking turboexpander

Abstract

The application discloses a turbine expander with electromagnetic braking, which comprises an expander, a sealing mechanism and a braking device. The expander comprises a first shell and an impeller, the first shell is provided with an air inlet hole, an air outlet hole and a containing space, and the impeller defines a plurality of driving gaps, which 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 spaced apart and arranged in the first shell, the driving gaps are located between the first sealing piece and the second sealing piece, the first sealing piece is provided with a plurality of spaced-apart first sealing portions, a first sealing gap is defined between two first sealing portions, the first sealing portions are arranged in a spaced-apart manner from the impeller, and the gas in the containing space enters the first sealing gap, so that the first sealing piece and the impeller are arranged in a sealed manner, and the second sealing piece is arranged in a sealed manner with the impeller. By guiding the gas to form a sealing gas film instead of a contact type sealing, the wear of the sealing components is avoided.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of turbo expanders, in particular to a turbo expander with electromagnetic braking. BACKGROUND

[0002] In the related art, during the operation of a turbo expander, gas is accelerated by a nozzle after entering the expander and acts on an impeller to drive the impeller to rotate. In order to prevent the gas from leaking from the edge of the impeller to the non-working area without undergoing complete expansion and work, a sealing structure needs to be provided at both ends of the impeller. However, most conventional sealing structures use single-stage static sealing or contact-type dynamic sealing. 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, which reduces the sealing performance of the expander and causes energy loss of the expander. SUMMARY

[0003] In order to prevent the sealing structure from wearing, improve the sealing performance of the expander, and reduce the energy loss of the expander, the present application provides a turbo expander with electromagnetic braking.

[0004] The turbo expander with electromagnetic braking provided by the present application adopts the following technical scheme:

[0005] A turbo expander with electromagnetic braking comprises an expander, the expander comprising a first housing and an impeller, the first housing being provided with an air inlet hole, an air outlet hole, and defining a containing space, the impeller being pivotally installed in the first housing, the impeller defining a plurality of driving gaps, the plurality of driving gaps being arranged at intervals along the circumferential direction of the impeller, the containing space being in communication with the air inlet hole, the driving gaps being in communication between the containing space and the air outlet hole, and the impeller being adapted to be driven to rotate by gas.

[0006] A sealing mechanism, the sealing mechanism comprising a first sealing member and a second sealing member, the first sealing member and the second sealing member being both arranged in the first housing, being arranged at intervals along the axial direction of the impeller, and both being located outside the impeller, the driving gaps being located between the first sealing member and the second sealing member, the first sealing member being located on the side of the impeller close to the air outlet hole, the first sealing member being provided with a plurality of first sealing portions close to the end wall of the impeller, the plurality of first sealing portions being arranged at intervals along the axial direction of the impeller, a first sealing gap being defined between any two adjacent first sealing portions, the first sealing portions being arranged at intervals from the impeller, gas in the containing space being adapted to enter the first sealing gap to seal the first sealing member from the impeller, and the second sealing member being sealed from the impeller.

[0007] A brake device is connected with the impeller, and is used for braking and adjusting the rotating speed of the impeller.

[0008] By adopting the technical scheme, the first sealing part is provided with a plurality of first sealing portions, and a first sealing gap is defined between any two adjacent first sealing portions. When the gas in the containing space flows into the first sealing gap, the gas in the first sealing gap forms an annular gas film between the first sealing part and the impeller. The sealing gas film blocks the gas in the containing space from passing through the gap between the first sealing part and the impeller, thereby realizing the non-contact sealing between the first sealing part and the impeller. Compared with the prior art, the stable sealing gas film is formed by guiding the gas instead of the traditional contact sealing mode, so that the sealing performance is ensured and the wear of the sealing component during the high-speed rotation of the impeller is avoided, thereby improving the sealing reliability of the turbo expander.

[0009] Preferably, along the direction from the outside to the inside of the first sealing part, the end wall of the first sealing part close to the gas outlet hole is arranged to be inclined towards the impeller.

[0010] By adopting the technical scheme, when the gas flows to the end wall of the first sealing part close to the gas outlet hole, the gas is guided by the end wall of the first sealing part close to the gas outlet hole and moves close to the gap between the first sealing part and the impeller. When the gas in the first sealing gap moves to the gap between the first sealing part and the impeller, the gas in the first sealing gap blocks the gas in the containing space from passing through the gap between the first sealing part and the impeller, thereby establishing a stable non-contact sealing structure between the first sealing part and the impeller, and improving the sealing reliability of the turbo expander.

[0011] Preferably, the end wall of the second sealing part close to the impeller is provided with a plurality of second sealing portions. The second sealing portions are arranged to be spaced apart along the axial direction of the impeller. The second sealing portions are arranged to be spaced apart from the impeller. A second sealing gap is defined between any two adjacent second sealing portions. The gas in the containing space is adapted to enter the second sealing gap, so as to seal the second sealing part and the impeller.

[0012] By adopting the technical scheme, 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 sealing part and the impeller. The annular gas film continuously blocks the gas in the containing space from passing through the gap between the second sealing part and the impeller, thereby preventing the gas in the containing space from leaking to the non-working area before completing the expansion work, and improving the sealing performance of the turbo expander.

[0013] Preferably, the brake device comprises a second housing, a brake shaft and a brake piece, the second housing is connected with the first housing, the second housing defines a mounting space communicated with the accommodating space, the brake shaft and the brake piece are arranged in the second housing, the brake shaft is pivotally connected with the second housing, the brake shaft extends into the first housing and is connected with the impeller, the brake shaft is provided with a magnetic piece, the brake piece forms a magnetic field, the brake shaft is located in the magnetic field, and the brake piece is used for braking the brake shaft.

[0014] By adopting the above technical scheme, the electromagnetic action is formed between the magnetic piece on the brake shaft and the brake piece, the brake piece applies electromagnetic force to the brake shaft to brake the impeller, thereby the problem that the impeller is damaged or fatigued due to high speed in the high-speed operation process can be avoided, and the operation safety and stability of the turbo expander in the high-pressure and high-speed working condition can be improved.

[0015] Preferably, the sealing mechanism further comprises a third sealing piece and a fourth sealing piece, the third sealing piece and the fourth sealing piece are arranged in the first housing, the third sealing piece and the fourth sealing piece are arranged in the axial direction of the brake shaft, the fourth sealing piece is located on the side of the third sealing piece away from the impeller, the third sealing piece and the fourth sealing piece are sleeved on the outer side of the brake shaft, and the third sealing piece and the fourth sealing piece are arranged opposite to and in sealing with the brake shaft.

[0016] By adopting the above technical scheme, the third sealing piece seals the brake shaft once, and the fourth sealing piece seals the brake shaft twice, and the gas is blocked by the third sealing piece and the fourth sealing piece, thereby the gas can be prevented from passing through the gap between the third sealing piece and the brake shaft and the gap between the fourth sealing piece and the brake shaft as much as possible, and the gas in the accommodating space can be prevented from flowing out to the external environment through the second housing.

[0017] Preferably, the third sealing piece is arranged in the axial direction of the brake shaft, a first sealing groove is arranged around the end wall of the third sealing piece close to the brake shaft, the gas is adapted to enter the first sealing groove, so that the third sealing piece and the brake shaft are arranged in sealing, and the gas pressure in the first sealing groove is higher than the gas pressure in the accommodating space.

[0018] By adopting the above technical scheme, under the action of the gas pressure difference, the gas in the first sealing groove flows to the gap between the third sealing piece and the brake shaft and forms a stable sealing gas film, thereby the gas in the accommodating space can be prevented from leaking to the outside through the gap between the third sealing piece and the brake shaft, and the sealing performance and the sealing reliability of the expander can be improved.

[0019] Preferably, the fourth sealing member is arranged in a spaced-apart manner relative to the brake shaft, a second sealing groove is arranged around an end wall of the brake shaft close to the fourth sealing member, and gas is adapted to enter the second sealing groove to seal the fourth sealing member and the brake shaft, and the gas pressure in the second sealing groove is higher than the gas pressure in the first sealing groove.

[0020] By using 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 sealing member and the brake shaft and forms a stable sealing gas film, thereby preventing the gas between the third sealing member and the fourth sealing member from leaking to the outside through the gap between the fourth sealing member and the brake shaft, and further improving the sealing performance and reliability of the expander.

[0021] Preferably, the end of the brake shaft away from the impeller is provided with a counterweight disc, the counterweight disc is provided with a plurality of counterweight holes, the plurality of counterweight holes are arranged in a spaced-apart manner along the circumferential direction of the counterweight disc, and the counterweight holes are used to accommodate one or more counterweight blocks, and the counterweight disc is used to adjust the dynamic balance of the brake shaft.

[0022] By using the above technical solution, by installing the counterweight block in the one or more counterweight holes of the counterweight disc according to the eccentricity or vibration under the rotation state of the brake shaft, the counterweight block forms a reverse torque for offsetting the centrifugal unbalanced force, thereby reducing the vibration deviation generated by the brake shaft during high-speed rotation, and further improving the stability and dynamic balance accuracy of the rotation of the brake shaft.

[0023] Preferably, the second housing is provided with a liquid inlet hole, a liquid outlet hole, and a heat dissipation pipeline, the heat dissipation pipeline is arranged around the outer peripheral wall of the brake member and the outer peripheral wall of the brake shaft, one end of the heat dissipation pipeline is connected and matched with the liquid inlet hole, and the other end is connected and matched with the liquid outlet hole, and cooling medium flows in the heat dissipation pipeline.

[0024] By using the above technical solution, the cooling medium exchanges heat with the brake member and the brake shaft, absorbs the heat generated by the brake member and the heat generated by the brake shaft, so as to maintain the temperature of the brake member and the temperature of the brake shaft within a preset temperature range, and the cooling medium in the heat dissipation pipeline flows out of the cooling pipeline through the liquid outlet hole.

[0025] Preferably, the impeller has a plurality of blades, the plurality of blades are arranged in a spaced-apart manner along the circumferential direction of the impeller, and the driving gap is defined between any two adjacent blades.

[0026] By adopting the technical scheme, the gas collides with the side wall of the blade, the gas pushes the blade to drive the impeller to rotate, under the joint action of the forces of the plurality of blades, the impeller is driven to rotate by the gas, and the rotation of the impeller realizes the expansion work process of the gas.

[0027] In summary, the present application includes at least one of the following beneficial technical effects:

[0028] 1. By arranging a plurality of first sealing portions on the first sealing member, and defining a first sealing gap between any two adjacent first sealing portions, when the gas in the containing space flows into the first sealing gap, the gas in the first sealing gap forms an annular gas film between the first sealing member and the impeller, and the sealing gas film blocks the gas in the containing space from passing through the gap between the first sealing member and the impeller, thereby realizing non-contact sealing between the first sealing member and the impeller. Compared with the prior art, by guiding the gas to form a stable sealing gas film instead of the traditional contact sealing mode, the sealing performance is ensured while avoiding wear of the sealing components during high-speed rotation of the impeller, thereby improving the sealing reliability of the turboexpander;

[0029] 2. Under the action of the gas pressure difference, the gas in the first sealing groove flows to the gap between the third sealing member and the brake shaft and forms a stable sealing gas film, thereby blocking the gas in the containing space from leaking to the outside through the gap between the third sealing member and the brake shaft, and further improving the sealing performance and sealing reliability of the expander;

[0030] 3. By installing the counterweight block in one or more counterweight holes of the counterweight disc according to the eccentricity or vibration under the rotation state of the brake shaft, the counterweight block forms a reverse torque for offsetting the centrifugal unbalanced force, thereby reducing the vibration deviation generated by the brake shaft during high-speed rotation, and further improving the stability and dynamic balance precision of the rotation of the brake shaft. BRIEF DESCRIPTION OF DRAWINGS

[0031] Figure 1 is a schematic view of a turboexpander with electromagnetic braking according to an embodiment of the present application;

[0032] Figure 2 is a sectional view of a turboexpander with electromagnetic braking according to an embodiment of the present application;

[0033] Figure 3 is Figure 2 is an enlarged schematic view of position A in FIG.

[0034] Figure 4 is Figure 2 is an enlarged schematic view of position B in FIG.

[0035] Figure 5 is Figure 2 is an enlarged schematic view of position C in FIG.

[0036] Figure 6 is a sectional view of an impeller according to an embodiment of the present application.

[0037] Reference Signs List:

[0038] 100, turbo expander with electromagnetic brake;

[0039] 1, expander; 11, first housing; 111, gas inlet hole; 112, gas outlet hole; 113, containing space; 12, impeller; 121, driving gap; 122, blade;

[0040] 2, sealing mechanism; 21, first sealing member; 211, first sealing part; 212, first sealing gap; 22, second sealing member; 221, second sealing part; 222, second sealing gap; 23, third sealing member; 231, first sealing groove; 24, fourth sealing member; 241, second sealing groove;

[0041] 3, braking device; 31, second housing; 311, mounting space; 312, liquid inlet hole; 313, liquid outlet hole; 32, brake shaft; 321, magnetic member; 322, counterweight disc; 3221, counterweight hole; 33, brake member. DETAILED DESCRIPTION

[0042] The following description will be made in conjunction with the accompanying drawings. Figures 1-6 The present application is described in further detail.

[0043] The present application discloses a turbo expander with electromagnetic brake 100.

[0044] Reference will be made to Figures 1-3 The turbo expander with electromagnetic brake 100 according to the embodiment of the present application comprises an expander 1, a sealing mechanism 2 and a braking device 3.

[0045] The expander 1 comprises a first housing 11 and an impeller 12, the first housing 11 is provided with a gas inlet hole 111, a gas outlet hole 112 and defines a containing 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 arranged at intervals along the circumferential direction of the impeller 12, the containing space 113 is in communication with the gas inlet hole 111, the driving gap 121 is in communication between the containing space 113 and the gas outlet hole 112, and the impeller 12 is adapted to be driven to rotate by the gas.

[0046] Specifically, the gas enters the containing space 113 through the gas inlet hole 111, the gas in the containing space 113 flows into the driving gap 121, and in the process of the gas in the containing space 113 flowing into the driving gap 121, the gas drives the impeller 12 to rotate, and the gas in the driving gap 121 flows into the gas outlet hole 112.

[0047] The sealing mechanism 2 comprises a first seal 21 and a second seal 22, both of which are arranged in the first housing 11 and are spaced apart along the axial direction of the impeller 12 and are both located on the outer side of the impeller 12. Specifically, the first seal 21 and the second seal 22 are both annularly arranged on the outer side of the impeller 12, and 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 gas outlet hole 112, and the second seal 22 is located on the side of the impeller 12 away from the gas outlet hole 112.

[0048] Further, the first seal 21 is provided with a plurality of first sealing portions 211 close to the end wall of the impeller 12, and the plurality of first sealing portions 211 are both arranged opposite to the outer peripheral wall of the impeller 12 and are spaced apart along the axial direction of the impeller 12. The first sealing gap 212 is defined between any two adjacent first sealing portions 211, and the first sealing portion 211 is spaced apart from the impeller 12. The gas in the accommodation space 113 is adapted to enter the first sealing gap 212 to seal the first seal 21 and the impeller 12. The second seal 22 is sealed with the impeller 12.

[0049] Specifically, along the axial direction of the impeller 12, the gas in the accommodation space 113 flows into the plurality of first sealing gaps 212 in sequence, and the gas in the first sealing gap 212 close to the gas outlet hole 112 flows into the gas outlet hole 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 sealed.

[0050] 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 gas outlet hole 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 the direction from the bottom of the first seal 21 to the top of the second seal 22. Figure 2In the up-down direction, the gas in the first sealing gap 212 moves upward, collides with the bottom wall of the first sealing gap 212, moves away from the outlet hole 112, collides with the first sealing part 211 of the first sealing gap 212 away from the outlet hole 112, and moves downward. When the gas in the first sealing gap 212 moves to the gap between the first sealing part 211 and the impeller 12, the gas in the containing space 113 pushes the gas in the first sealing gap 212 to move close to the outlet hole 112, so that the gas in the first sealing gap 212 moves in a circle in the first sealing gap 212, and the gas forms an annular gas film in the first sealing gap 212.

[0051] The gas is deflected along the circumferential direction of the first sealing gap 212 and continuously moves in a circle in the first sealing gap 212 around the impeller 12. As the gas is continuously pushed into the gap and moves in a circle in the gap, the gas gradually forms an annular gas film covering the entire gap path between the first sealing part 21 and the impeller 12.

[0052] The brake device 3 is connected and matched with the impeller 12, and is used to brake and adjust the rotating speed of the impeller 12. Specifically, when the rotating speed of the impeller 12 is higher than a preset rotating speed, the brake device 3 brakes the impeller 12 to reduce the rotating speed of the impeller 12, so as to prevent the structure of the impeller 12 from being damaged due to the too high rotating speed of the impeller 12.

[0053] Therefore, by arranging a plurality of first sealing parts 211 on the first sealing part 21, and defining a first sealing gap 212 between any two adjacent first sealing parts 211, when the gas in the containing space 113 flows into the first sealing gap 212, the gas in the first sealing gap 212 forms an annular gas film between the first sealing part 21 and the impeller 12, and the sealing gas film blocks the gas in the containing space 113 from passing through the gap between the first sealing part 21 and the impeller 12, thereby realizing the non-contact sealing between the first sealing part 21 and the impeller 12. Compared with the prior art, by guiding the gas to form a stable sealing gas film instead of the traditional contact sealing mode, the sealing performance is guaranteed while the wear of the sealing part during the high-speed rotation of the impeller 12 is avoided, so as to improve the sealing reliability of the turbine expander 1.

[0054] Reference Figure 3In some embodiments of the present application, the first sealing part 211 is arranged to be inclined towards the impeller 12 along a direction from outside to inside of the first sealing member 21, in particular, the lower end of the first sealing part 211 close to the end wall of the outlet hole 112 is inclined towards the impeller 12 along the height direction of the expander 1.

[0055] After the gas in the accommodation space 113 enters the first sealing gap 212, the gas in the first sealing gap 212 continues to rotate to form an annular gas film. When the gas in the first sealing gap 212 flows to the position of the first sealing part 211 close to the end wall of the outlet hole 112, the gas in the first sealing gap 212 is guided by the first sealing part 211 close to the end wall of the outlet hole 112, and moves towards the gap between the first sealing part 211 and the impeller 12 along the first sealing part 211 close to the end wall of the outlet hole 112. When the gas in the first sealing gap 212 moves to the gap between the first sealing part 211 and the impeller 12, the gas in the first sealing gap 212 blocks the gas in the accommodation space 113 from passing through the gap between the first sealing member 21 and the impeller 12.

[0056] When the gas flows to the position of the first sealing part 211 close to the end wall of the outlet hole 112, the gas is guided by the first sealing part 211 close to the end wall of the outlet hole 112 and moves towards the gap between the first sealing part 211 and the impeller 12. When the gas in the first sealing gap 212 moves to the gap between the first sealing part 211 and the impeller 12, the gas in the first sealing gap 212 blocks the gas in the accommodation space 113 from passing through the gap between the first sealing member 21 and the impeller 12, so that a stable non-contact sealing structure can be established between the first sealing part 211 and the impeller 12, thereby improving the sealing reliability of the turbo expander 1.

[0057] Referring to Figure 2 and Figure 3 In some embodiments of the present application, the second sealing member 22 is located on the side of the impeller 12 away from the outlet hole 112, and the second sealing member 22 is provided with a plurality of second sealing parts 221 close to the end wall of the impeller 12. The plurality of second sealing parts 221 are opposite to the outer peripheral wall of the impeller 12 and are arranged to be spaced apart along the axial direction of the impeller 12. The second sealing part 221 is spaced apart from the impeller 12, and the second sealing gap 222 is defined between any two adjacent second sealing parts 221. The gas in the accommodation space 113 is adapted to enter the second sealing gap 222 to seal between the second sealing member 22 and the impeller 12.

[0058] In the axial direction of the impeller 12, the gas in the accommodation space 113 flows into the plurality of second sealing gaps 222 in sequence, and 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 sealing member 22 and the impeller 12, and the annular gas film is used to block the gas in the accommodation space 113 from passing through the gap between the second sealing member 22 and the impeller 12, so that the second sealing member 22 and the impeller 12 are sealingly arranged.

[0059] It should be noted that when the gas enters the second sealing gap 222, the gas collides with the second sealing portion 221 in the second sealing gap 222 away from the impeller 12, and under the continuous pushing action of the gas in the accommodation space 113, the gas in the second sealing gap 222 moves upward in the height direction of the expander 1, and then the gas in the second sealing gap 222 collides with the bottom wall of the second sealing gap 222, and the gas in the second sealing gap 222 moves towards the direction close to the impeller 12, and the gas in the second sealing gap 222 collides with the second sealing portion 221 in the second sealing gap 222 close to the impeller 12, and the gas in the second sealing gap 222 moves downward, and when the gas in the second sealing gap 222 moves 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 away from the impeller 12 to make the gas in the second sealing gap 222 make a circular motion in the second sealing gap 222, and the gas forms an annular gas film in the second sealing gap 222.

[0060] 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 sealing member 22 and the impeller 12, and the annular gas film is used to continuously block the gas in the accommodation space 113 from passing through the gap between the second sealing member 22 and the impeller 12, so that the gas in the accommodation space 113 can be prevented from leaking to the non-working area before completing the expansion work, thereby improving the sealing performance of the turbine expander 1.

[0061] Referring to Figure 1 and Figure 2In some embodiments of the present application, the braking device 3 comprises a second housing 31, a braking shaft 32 and a braking piece 33. The second housing 31 is connected to the first housing 11 and is located on the side of the impeller 12 away from the air outlet hole 112. The second housing 31 defines an installation space 311 that is in communication with the containing space 113. The braking shaft 32 and the braking piece 33 are both arranged in the second housing 31. The braking piece 33 is sleeved on the outside of the braking shaft 32. The braking shaft 32 is pivotally connected to the second housing 31 and extends into the first housing 11 and is connected to the impeller 12. The braking shaft 32 is located on the side of the impeller 12 away from the air outlet hole 112. The braking shaft 32 is provided with a magnetic piece 321. The braking piece 33 forms a magnetic field. The braking shaft 32 is located in the magnetic field. The electromagnetic force acting on the braking shaft 32 serves as a braking force. The braking piece 33 is used to brake the braking shaft 32.

[0062] In some specific embodiments, the braking piece 33 can be an electromagnetic induction coil, but the present application is not limited thereto. The braking piece 33 can also be a wire armature.

[0063] The gas in the containing space 113 drives the impeller 12 to rotate. The impeller 12 drives the braking shaft 32 to rotate. When the braking shaft 32 rotates, the magnetic piece 321 on the braking shaft 32 and the braking piece 33 form an electromagnetic action. The braking piece 33 exerts an electromagnetic force on the braking shaft 32 to brake the braking shaft 32, so as to prevent the rotation speed of the impeller 12 from being greater than the preset rotation speed.

[0064] By forming an electromagnetic action between the magnetic piece 321 on the braking shaft 32 and the braking piece 33, the braking piece 33 exerts an electromagnetic force on the braking shaft 32 to brake the impeller 12, so as to avoid the problem that the structure of the impeller 12 is fatigued or damaged due to excessively high rotation speed during high-speed operation. Therefore, the running safety and stability of the turbo expander 1 under high-pressure and high-speed working conditions can be improved.

[0065] Further, the braking piece 33 or the braking shaft 32 can be electrically connected to an electricity storage piece. When the braking shaft 32 rotates, the magnetic piece 321 on the braking shaft 32 cuts the magnetic field formed by the braking piece 33. An induced electromotive force is formed between the braking shaft 32 and the braking piece 33. The current on the braking piece 33 or the braking shaft 32 flows into the electricity storage piece. The electricity storage piece stores electrical energy.

[0066] In some specific embodiments, the electricity storage piece can be a battery or the like.

[0067] Reference Figure 2 and Figure 4In some embodiments of the present application, the sealing mechanism 2 further comprises a third seal 23 and a fourth seal 24, both of which are arranged in the first housing 11 and are spaced apart along the axial direction of the brake shaft 32, the fourth seal 24 being located on the side of the third seal 23 away from the impeller 12, both of the third seal 23 and the fourth seal 24 being sleeved on the outer side of the brake shaft 32 and being arranged opposite to and sealingly arranged with the brake shaft 32.

[0068] When the gas in the accommodation space 113 flows towards the mounting space 311 and flows to the third seal 23 and the fourth seal 24, the third seal 23 seals the brake shaft 32 once and the fourth seal 24 seals the brake shaft 32 twice, and the gas is blocked by the third seal 23 and the fourth seal 24 together, so as to prevent the gas from passing through the gap between the third seal 23 and the brake shaft 32 and the gap between the fourth seal 24 and the brake shaft 32 as much as possible, thereby preventing the gas in the accommodation space 113 from flowing out to the external environment through the second housing 31.

[0069] Referring 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, and a first sealing groove 231 is arranged around the end wall of the third seal 23 close to the brake shaft 32, the gas being adapted to enter the first sealing groove 231 so as to be sealingly arranged between the third seal 23 and the brake shaft 32, the gas pressure in the first sealing groove 231 being higher than that in the accommodation space 113.

[0070] In some specific embodiments, the first sealing groove 231 can be in communication with a gas pump for conveying gas into the first sealing groove 231.

[0071] The gas enters the first sealing groove 231 to fill the first sealing groove 231, and the gas pressure in the first sealing groove 231 is higher than that in the accommodation space 113, so that under the action of the gas pressure difference, the gas in the first sealing groove 231 flows to the gap between the third seal 23 and the brake shaft 32, the gas in the first sealing 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.

[0072] Under the action of the gas pressure difference, the gas in the first sealing groove 231 flows to the gap between the third sealing member 23 and the brake shaft 32 and forms a stable sealing gas film, so that the gas in the containing space 113 can be blocked from leaking to the outside through the gap between the third sealing member 23 and the brake shaft 32, thereby improving the sealing performance and sealing reliability of the expander 1.

[0073] With reference to Figure 2 and Figure 4 In some embodiments of the present application, the fourth sealing member 24 is spaced apart from the brake shaft 32, and the second sealing groove 241 is arranged around the end wall of the brake shaft 32 close to the fourth sealing member 24. The gas is adapted to enter the second sealing groove 241 to seal between the fourth sealing member 24 and the brake shaft 32. The gas pressure in the second sealing groove 241 is higher than that in the first sealing groove 231.

[0074] In some specific embodiments, the second sealing groove 241 can be in communication with a gas pump for delivering gas into the second sealing groove 241.

[0075] The gas enters the second sealing groove 241 to fill the second sealing groove 241. The gas pressure in the second sealing groove 241 is higher than that in the first sealing groove 231. Under the action of the gas pressure difference, the gas in the second sealing groove 241 flows to the gap between the fourth sealing member 24 and the brake shaft 32. The gas in the second sealing groove 241 fills the gap between the fourth sealing member 24 and the brake shaft 32 and forms a stable sealing gas film. The sealing gas film blocks the gas between the third sealing member 23 and the fourth sealing member 24 from passing through the gap between the fourth sealing member 24 and the brake shaft 32.

[0076] Under the action of the gas pressure difference, the gas in the second sealing groove 241 flows to the gap between the fourth sealing member 24 and the brake shaft 32 and forms a stable sealing gas film, so that the gas between the third sealing member 23 and the fourth sealing member 24 can be blocked from leaking to the outside through the gap between the fourth sealing member 24 and the brake shaft 32, thereby improving the sealing performance and sealing reliability of the expander 1.

[0077] With reference to Figure 2 and Figure 5 In some embodiments of the present application, the end of the brake shaft 32 away from the impeller 12 is provided with a counterweight disc 322. The counterweight disc 322 is provided with a plurality of counterweight holes 3221 spaced apart along the circumferential direction of the counterweight disc 322. The counterweight holes 3221 are used to accommodate one or more counterweight blocks. The counterweight disc 322 is used to adjust the dynamic balance of the brake shaft 32.

[0078] In the process of rotating the brake shaft 32 driven by the impeller 12, the eccentricity or vibration of the brake shaft 32 in the rotating state is measured to determine the mass imbalance area of the brake shaft 32 in a certain angular direction, and the counterweight block is installed in the corresponding counterweight hole 3221 according to the position of the imbalance area and the mass to be compensated. The counterweight disc 322 forms a reverse torque to the brake shaft 32 through the position distribution and mass adjustment of the counterweight block, so as to compensate the centrifugal imbalance force generated in the rotating process of the brake shaft 32, and realize the dynamic balance adjustment of the rotation of the brake shaft 32.

[0079] By installing the counterweight block in one or more counterweight holes 3221 of the counterweight disc 322 according to the eccentricity or vibration of the brake shaft 32 in the rotating state, the counterweight block forms a reverse torque for offsetting the centrifugal imbalance force, so as to reduce the vibration deviation generated in the high-speed rotating process of the brake shaft 32, and further improve the stability and dynamic balance precision of the rotation of the brake shaft 32.

[0080] Referring to Figure 2 In some embodiments of the present application, the second shell 31 is provided with a liquid inlet hole 312, a liquid outlet hole 313 and a heat dissipation pipeline, the heat dissipation pipeline is arranged 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, the other end of the heat dissipation pipeline is connected and matched with the liquid outlet hole 313, and the heat dissipation pipeline flows with cooling medium.

[0081] In some specific embodiments, the liquid inlet hole 312 can be communicated with a liquid delivery pump, the liquid delivery pump is used to deliver the cooling medium to the heat dissipation pipeline, and the liquid outlet hole 313 can be communicated with a storage pool, the storage pool is used to store the cooling medium.

[0082] In some specific embodiments, the cooling medium can be liquid nitrogen.

[0083] The cooling medium enters into the heat dissipation pipeline through the liquid inlet hole 312, flows along the heat dissipation pipeline under the action of external pumping pressure, 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, exchanges heat with the brake member 33 and the brake shaft 32, absorbs the heat generated by the brake member 33 and the heat generated by the brake shaft 32, so as to maintain the temperature of the brake member 33 and the temperature of the brake shaft 32 within a preset temperature range, and the cooling medium in the heat dissipation pipeline flows out of the cooling pipeline through the liquid outlet hole 313.

[0084] Referring to Figure 2 , Figure 3 and Figure 6In some embodiments of the present application, the impeller 12 has a plurality of blades 122, the plurality of blades 122 are arranged at intervals along the circumferential direction of the impeller 12, and a driving gap 121 is defined between any two adjacent blades 122, and the gas is suitable for driving the blades 122 to rotate the impeller 12.

[0085] The gas enters the containing space 113 through the gas inlet hole 111, the gas in the containing space 113 flows into the driving gap 121, and in the process of flowing in the driving gap 121, the gas collides with the side wall of the blade 122, the gas pushes the blade 122 to rotate the impeller 12, under the joint action of the force of 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, and after the gas completes the work, it is discharged to the outside of the first shell 11 through the gas outlet hole 112.

[0086] The above are preferred embodiments of the present application, not limited by the protection scope of the present application, therefore: any equivalent changes made according to the structure, shape, principle of the present application should be covered within the protection scope of the present application.

Claims

1. An electromagnetic-braked turboexpander characterized in that, The expansion machine comprises a first shell and an impeller, the first shell is provided with an air inlet hole, an air outlet hole and a containing space, the impeller is pivotally installed in the first shell, the impeller defines a plurality of driving gaps, the plurality of driving gaps are arranged at intervals along the circumferential direction of the impeller, the containing space is communicated with the air inlet hole, the driving gaps are communicated between the containing space and the air outlet hole, and the impeller is adapted to be driven to rotate by the gas. 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, and the first sealing piece and the second sealing piece are arranged at intervals along the axial direction of the impeller and are located on the outer side of the impeller, the driving gap is located between the first sealing piece and the second sealing piece, the first sealing piece is located on the side of the impeller close to the air outlet hole, the end wall close to the impeller of the first sealing piece is provided with a plurality of first sealing portions, the plurality of first sealing portions are arranged at intervals 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 arranged at intervals from the impeller, and the gas in the containing space is adapted to enter the first sealing gap to seal the first sealing piece and the impeller. The brake device is connected with the impeller, and is used for braking and adjusting the rotating speed of the impeller; the brake device comprises a second shell, a brake shaft and a brake piece, the second shell is connected with the first shell, the brake shaft and the brake piece are arranged in the second shell, the brake shaft is pivotally connected with the second shell, and the brake shaft extends into the first shell and is connected with the impeller. In the direction from the outside to the inside of the first sealing piece, the end wall of the first sealing portion close to the air outlet hole is inclinedly arranged towards the impeller. The sealing mechanism further comprises a third sealing piece and a fourth sealing piece, the third sealing piece and the fourth sealing piece are arranged in the first shell, the third sealing piece and the fourth sealing piece are arranged at intervals along the axial direction of the brake shaft, the fourth sealing piece is located on the side of the third sealing piece away from the impeller, the third sealing piece and the fourth sealing piece are sleeved on the outer side of the brake shaft, and the third sealing piece and the fourth sealing piece are opposite to the brake shaft and are sealingly arranged. The third sealing piece is arranged at intervals from the brake shaft, a first sealing groove is annularly arranged on the end wall close to the brake shaft of the third sealing piece, the gas is adapted to enter the first sealing groove to seal the third sealing piece and the brake shaft, and the gas pressure in the first sealing groove is higher than that in the containing space. The fourth sealing piece is arranged at intervals from the brake shaft, a second sealing groove is annularly arranged on the end wall close to the brake shaft of the fourth sealing piece, the gas is adapted to enter the second sealing groove to seal the fourth sealing piece and the brake shaft, and the gas pressure in the second sealing groove is higher than that in the first sealing groove. The end wall close to the impeller of the second sealing piece is provided with a plurality of second sealing portions, the plurality of second sealing portions are arranged at intervals along the axial direction of the impeller, the second sealing portion is arranged at intervals from the impeller, a second sealing gap is defined between any two adjacent second sealing portions, and the gas in the containing space is adapted to enter the second sealing gap to seal the second sealing piece and the impeller.

2. An electromagnetic-braked turboexpander according to claim 1, characterized in that, ​ 3. An electromagnetic-braked turboexpander according to claim 2, characterized in that, The second shell defines a mounting space in communication with the accommodating space, the brake shaft is provided with a magnetic element, the brake element forms a magnetic field, the brake shaft is located in the magnetic field, and an electromagnetic force acting on the brake shaft serves as a brake force, and the brake element is used to brake the brake shaft.

4. An electromagnetic-braked turboexpander according to claim 3, characterized in that The end of the brake shaft away from the impeller is provided with a counterweight disc, the counterweight disc is provided with a plurality of counterweight holes, the plurality of counterweight holes are arranged at intervals along the circumferential direction of the counterweight disc, the counterweight holes are used to accommodate one or more counterweight blocks, and the counterweight disc is used to adjust the dynamic balance of the brake shaft.

5. An electromagnetic-braked turboexpander according to claim 3, characterized in that, The second shell is provided with a liquid inlet hole, a liquid outlet hole and a heat dissipation pipeline, the heat dissipation pipeline is arranged around the outer circumferential wall of the brake element and the outer circumferential wall of the brake shaft, one end of the heat dissipation pipeline is connected and matched with the liquid inlet hole, and the other end is connected and matched with the liquid outlet hole, and a cooling medium flows in the heat dissipation pipeline.

6. An electromagnetic-braked turboexpander according to claim 1, characterized in that, The impeller has a plurality of blades, the plurality of blades are arranged at intervals along the circumferential direction of the impeller, a driving gap is defined between any two adjacent blades, and the gas is suitable for driving the blades to drive the impeller to rotate.

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