阅读说明：本技术 一种螺杆膨胀机密封结构 (screw expander sealing structure ) 是由 张功旺 江涛 范顺香 杨华英 于 2019-09-02 设计创作，主要内容包括：本发明涉及一种热动力机械技术领域,具体涉及一种螺杆膨胀机密封结构,所述密封结构设置在螺杆转轴两端的台阶与壳体内壁组成的空间内,其特征在于,包括机械密封部分和非接触式密封部分；本发明提供的螺杆膨胀机密封结构,采用非接触式密封和机械密封两种形式组成的集装式密封形式,在保证密封性的同时,与现有轴封形式相比较,结构更加简单,且设置有能够充注阻塞液的充注孔和判断内部零件损坏的引流孔,使螺杆膨胀机在高转速工况下平稳运行,减少了油、水、气泄露的风险,延长了轴封使用寿命,降低螺杆膨胀机使用成本。(The invention relates to the technical field of thermal power machinery, in particular to a sealing structure of a screw expander, which is arranged in a space formed by steps at two ends of a screw rotating shaft and the inner wall of a shell and is characterized by comprising a mechanical sealing part and a non-contact sealing part; the screw expander sealing structure provided by the invention adopts a packaging type sealing form consisting of a non-contact type sealing form and a mechanical sealing form, ensures the sealing property, is simpler in structure compared with the existing shaft seal form, and is provided with the filling hole capable of filling the blocking liquid and the drainage hole capable of judging the damage of internal parts, so that the screw expander can stably run under the working condition of high rotating speed, the risk of oil, water and gas leakage is reduced, the service life of the shaft seal is prolonged, and the use cost of the screw expander is reduced.)

1. A screw expander sealing structure is arranged in a space formed by steps at two ends of a screw rotating shaft and an inner wall of a shell and is characterized by comprising a mechanical sealing part and a non-contact sealing part;

The mechanical sealing part comprises a movable ring seat, a movable ring, a first static ring seat, a first static ring, a second static ring seat and a second static ring;

the movable ring seat is sleeved and fixed at the step of the screw rotating shaft, and one end of the movable ring seat is sleeved and fixed with the movable ring;

The first static ring seat and the second static ring seat are respectively arranged at two ends of a shaft seal cavity formed by the shell and the screw rotating shaft, the first static ring is fixedly connected with the first static ring seat through a first elastic part, the second static ring is fixedly connected with the second static ring seat through a second elastic part, and the first static ring and the second static ring are respectively contacted with two sides of the movable ring and form mechanical seal;

The non-contact sealing part comprises a movable sealing element and a static sealing element, the movable sealing element is sleeved and fixed at one end, away from the movable ring, of the movable ring seat, the static sealing element is opposite to the movable sealing element and is arranged at one end, away from the first static ring, of the first static ring seat, a sealing channel is formed between the static sealing element and the movable sealing element, a non-contact sealing ring is arranged in the sealing channel, and two pressure relief grooves are formed in the static sealing element.

2. the screw expander sealing structure as claimed in claim 1, wherein the first elastic member comprises a first spring and a first washer, one end of the first spring is connected to the first stationary ring seat, the other end of the first spring is connected to the first washer, and one side of the first washer, which is far away from the first spring, is connected to the first stationary ring.

3. The screw expander sealing structure as claimed in claim 1, wherein the second elastic member comprises a second spring and a second washer, one end of the second spring is connected to the second stationary ring seat, the other end of the second spring is connected to the second washer, and the side of the second washer, which is far away from the second spring, is connected to the second stationary ring.

4. The screw expander seal structure of claim 1, wherein the parts of the first stationary ring and the second stationary ring contacting the moving ring are provided with narrow end face structures.

5. The screw expander sealing structure of claim 1, wherein sealing rings are disposed between the inner walls of the first stationary ring seat, between the first stationary ring seat and the stationary sealing member, between the first stationary ring seat and the first stationary ring, between the second stationary ring seat and the inner wall of the casing, between the second stationary ring seat and the first stationary ring seat, between the second stationary ring seat and the second stationary ring, between the movable ring seat and the screw shaft, between the movable ring seat and the movable sealing member, and between the movable ring seat and the movable ring.

6. the screw expander sealing structure as claimed in claim 1, wherein anti-rotation pins are disposed between the movable ring seat and the screw shaft, between the second stationary ring seat and the inner wall of the casing, and between the movable ring seat and the movable ring.

7. The screw expander sealing structure as claimed in claim 1, wherein one side of the movable ring abuts against the movable ring seat, and the other side of the movable ring is provided with a retaining ring, and the retaining ring is locked on the movable ring seat through a set screw.

8. the screw expander sealing structure as claimed in claim 1, wherein the bottom surface of the second stationary ring seat, the side surfaces of the first stationary ring and the second stationary ring, and the top surface of the movable ring together form a sealing chamber, the second stationary ring seat is provided with a filling hole, one end of the filling hole penetrates through the housing to be communicated with the external environment, and the other end of the filling hole is communicated with the sealing chamber.

9. The screw expander sealing structure of claim 1, wherein the first stationary ring seat is provided with a drainage hole, one end of the drainage hole passes through the shell to be communicated with the external environment, and the other end of the drainage hole is communicated with the cavity between the first stationary ring seat and the movable ring seat.

Technical Field

The invention relates to the technical field of thermal power machinery, in particular to a sealing structure of a screw expander.

Background

the screw expander is a heat engine which drives a screw rotor to rotate by means of gas volume expansion and converts heat energy into mechanical energy. The power machine is a new power machine which is developed in the 21 st century, can be widely applied to the fields of industrial waste heat recovery, geothermal power generation, biomass power generation and the like, can directly drive a generator, and can also directly drive mechanical equipment such as a pump, a fan and the like.

The screw expander is mainly composed of a pair of screw rotors and a casing which are meshed with each other, the rotors and the rotors, and the rotors and the casing are sealed by gaps to form a working cavity with continuously variable volume, and a gas with certain pressure and temperature is formed by utilizing heat sources such as steam, hot water or steam-liquid two-phase flow, and the like, and the gas with certain pressure and temperature expands in volume to drive the screw rotors to rotate, so that heat energy is converted into mechanical energy. Particularly, for a screw expander rotating at a high speed, high requirements are imposed on a sealing structure, and due to the cooling and lubricating requirements of the screw expander and the high sealing requirements on a working medium, oil, water and gas are strictly separated.

For example, the invention patent with the publication number of CN103867232B discloses a screw expander with good sealing performance, wherein the screw expander is provided with a quadruple seal consisting of four sealing forms, namely a spiral seal, a mechanical seal, a labyrinth seal and a centrifugal seal, so that the screw expander has good sealing performance, can well separate water from oil, can prevent the water from entering an oil system, and can ensure the normal operation of the screw expander. The invention adopts various sealing modes to seal the screw expander, and has the problems of complex structure and incapability of detecting fault positions in time although the sealing property is improved.

disclosure of Invention

The technical problem to be solved by the invention is as follows: the screw expander sealing structure is simple in structure and good in sealing performance.

In order to solve the technical problems, the invention adopts the technical scheme that: a screw expander sealing structure is arranged in a space formed by steps at two ends of a screw rotating shaft and an inner wall of a shell and comprises a mechanical sealing part and a non-contact sealing part;

The mechanical sealing part comprises a movable ring seat, a movable ring, a first static ring seat, a first static ring, a second static ring seat and a second static ring;

the movable ring seat is sleeved and fixed at the step of the screw rotating shaft, and one end of the movable ring seat is sleeved and fixed with the movable ring;

The first static ring seat and the second static ring seat are respectively arranged at two ends of a shaft seal cavity formed by the shell and the screw rotating shaft, the first static ring is fixedly connected with the first static ring seat through a first elastic part, the second static ring is fixedly connected with the second static ring seat through a second elastic part, and the first static ring and the second static ring are respectively contacted with two sides of the movable ring and form mechanical seal;

the non-contact sealing part comprises a movable sealing element and a static sealing element, the movable sealing element is sleeved and fixed at one end, away from the movable ring, of the movable ring seat, the static sealing element is opposite to the movable sealing element and is arranged at one end, away from the first static ring, of the first static ring seat, a sealing channel is formed between the static sealing element and the movable sealing element, a non-contact sealing ring is arranged in the sealing channel, and two pressure relief grooves are formed in the static sealing element.

the first elastic piece comprises a first spring and a first gasket, one end of the first spring is connected with the first stationary ring seat, the other end of the first spring is connected with the first gasket, and one side, far away from the first spring, of the first gasket is connected with the first stationary ring.

the second elastic piece comprises a second spring and a second gasket, one end of the second spring is connected with the second stationary ring seat, the other end of the second spring is connected with the second gasket, and one side, far away from the second spring, of the second gasket is connected with the second stationary ring.

And the parts of the first static ring and the second static ring, which are contacted with the dynamic ring, are provided with narrow end surface structures.

Sealing rings are arranged between the inner walls of the first static ring seat shell, between the first static ring seat and the static sealing element, between the first static ring seat and the first static ring, between the second static ring seat and the inner wall of the shell, between the second static ring seat and the first static ring seat, between the second static ring seat and the second static ring, between the movable ring seat and the screw rotating shaft, between the movable ring seat and the movable sealing element and between the movable ring seat and the movable ring.

And anti-rotation pins are arranged between the movable ring seat and the screw rotating shaft, between the second stationary ring seat and the inner wall of the shell and between the movable ring seat and the movable ring.

One side of the movable ring is abutted against the movable ring seat, the other side of the movable ring is provided with a check ring, and the check ring is locked on the movable ring seat through a set screw.

the bottom surface of the second stationary ring seat, the side surfaces of the first stationary ring and the second stationary ring and the top surface of the movable ring form a sealing cavity together, a filling hole is formed in the second stationary ring seat, one end of the filling hole penetrates through the shell to be communicated with the external environment, and the other end of the filling hole is communicated with the sealing cavity.

the first stationary ring seat is provided with a drainage hole, one end of the drainage hole penetrates through the shell to be communicated with the external environment, and the other end of the drainage hole is communicated with a cavity between the first stationary ring seat and the movable ring seat.

the invention has the beneficial effects that: the screw expander sealing structure provided by the invention adopts a packaging type sealing form consisting of a non-contact type sealing form and a mechanical sealing form, ensures the sealing property, is simpler in structure compared with the existing shaft seal form, and is provided with the filling hole capable of filling blocking liquid and the drainage hole capable of judging the damage of internal parts, so that the screw expander can stably run under the working condition of high rotating speed, the risk of oil, water and gas leakage is reduced, the service life of the shaft seal is prolonged, and the use cost of the screw expander is reduced.

Drawings

FIG. 1 is a schematic structural diagram of a sealing structure of a screw expander according to an embodiment of the present invention;

description of reference numerals:

1. a mechanical seal portion; 11. a movable ring seat; 12. a moving ring; 121. a retainer ring; 13. a first stationary ring seat; 131. a first spring; 132. a first gasket; 133. a drainage hole; 14. a first stationary ring; 15. a second stationary ring seat; 151. a second spring; 152. a second gasket; 153. a fill hole; 16. a second stationary ring; 17. a seal ring; 18. anti-rotation pins;

2. a non-contact seal portion; 21. a dynamic seal; 22. a static seal; 23. sealing the channel; 24. a non-contact seal ring;

3. A housing;

4. A screw rotating shaft.

Detailed Description

In order to explain technical contents, achieved objects, and effects of the present invention in detail, the following description is made with reference to the accompanying drawings in combination with the embodiments.

Referring to fig. 1, the sealing structure of the screw expander of the present invention is disposed in a space formed by steps at two ends of a screw rotating shaft 4 and an inner wall of a housing 3, and includes a mechanical sealing portion 1 and a non-contact sealing portion 2;

the mechanical sealing part 1 comprises a movable ring seat 11, a movable ring 12, a first static ring seat 13, a first static ring 14, a second static ring seat 15 and a second static ring 16;

the movable ring seat 11 is sleeved and fixed at the step of the screw rotating shaft 4, and the movable ring 12 is sleeved and fixed at one end of the movable ring seat 11;

The first stationary ring seat 13 and the second stationary ring seat 15 are respectively arranged at two ends of a shaft seal cavity formed by the shell 3 and the screw rotating shaft 4, the first stationary ring 14 is fixedly connected with the first stationary ring seat 13 through a first elastic piece, the second stationary ring 16 is fixedly connected with the second stationary ring seat 15 through a second elastic piece, and the first stationary ring 14 and the second stationary ring 16 are respectively contacted with two sides of the movable ring 12 and form mechanical seal;

The non-contact type sealing part 2 comprises a movable sealing element 21 and a static sealing element 22, the movable sealing element 21 is fixedly sleeved on one end, far away from the movable ring 12, of the movable ring seat 11, the static sealing element 22 is opposite to the movable sealing element 21 and is arranged at one end, far away from the first static ring 14, of the first static ring seat 13, a sealing channel 23 is formed between the static sealing element 22 and the movable sealing element 21, a non-contact sealing ring 24 is arranged in the sealing channel 23, and two pressure relief grooves are formed in the static sealing element 22.

The working principle of the sealing structure of the screw expander is as follows: when the non-contact type sealing part 2 works, the dynamic sealing element 21 rotates along with the screw rotating shaft 4, the dynamic sealing element 21 is matched with the static sealing element 22 but is in non-contact sealing (a non-contact type sealing ring is arranged between the dynamic sealing element 21 and the static sealing element 22, and a sealing channel 23 between the dynamic sealing element 21 and the static sealing element 22 forms a layer of oil film to well play a role in sealing), so that the abrasion of the dynamic sealing element 21 and the static sealing element 22 under the high-speed working state of the screw expander is avoided, two pressure relief grooves are arranged on the static sealing element 22, and the existence of the pressure relief grooves strengthens the sealing performance of the non-contact type sealing; the mechanical sealing part 1, the movable ring seat 11 and the movable ring 12 rotate together with the screw rotating shaft 4, the first stationary ring 14 is in matched contact sealing with the movable ring 12, a first elastic part is arranged between the first stationary ring 14 and the first stationary ring seat 13, and when the first stationary ring 14 and the movable ring 12 are abraded, the first stationary ring 14 and the movable ring 12 can still be in matched contact sealing due to the compensation effect of the first elastic mechanism; the second stationary ring 16 is in contact seal with the moving ring 12 in a matching mode, a second elastic part is arranged between the second stationary ring 16 and the second stationary ring seat 15, and when the second stationary ring 16 and the moving ring 12 are abraded, the second stationary ring 16 and the moving ring 12 can still be in contact seal in a matching mode due to the compensation effect of the second elastic mechanism.

as can be seen from the above description, the beneficial effects of the present invention are: the screw expander sealing structure provided by the invention adopts a packaging type sealing form consisting of a non-contact type sealing form and a mechanical sealing form, ensures the sealing property, is simpler in structure compared with the existing shaft seal form, and is provided with the filling hole capable of filling the blocking liquid and the drainage hole capable of judging the damage of internal parts, so that the screw expander can stably run under the working condition of high rotating speed, the risk of oil, water and gas leakage is reduced, the service life of the shaft seal is prolonged, and the use cost of the screw expander is reduced.

further, the first elastic member includes a first spring 131 and a first washer 132, one end of the first spring 131 is connected to the first stationary ring base 13, the other end of the first spring is connected to the first washer 132, and one side of the first washer 132, which is far away from the first spring 131, is connected to the first stationary ring 14.

Further, the second elastic member includes a second spring 151 and a second washer 152, one end of the second spring 151 is connected to the second stationary ring seat 15, the other end is connected to the second washer 152, and a side of the second washer 152 away from the second spring is connected to the second stationary ring 16.

further, the parts of the first stationary ring 14 and the second stationary ring 16, which are in contact with the moving ring 12, are provided with narrow end face structures.

As can be seen from the above description, by performing the narrow end surface design on the first stationary ring and the second stationary ring, the contact area between the first stationary ring and the moving ring and between the second stationary ring and the moving ring is reduced, thereby reducing the heat generation area.

Further, sealing rings 17 are arranged between the inner walls of the shell 3 of the first stationary ring seat 13, between the first stationary ring seat 13 and the stationary sealing element 22, between the first stationary ring seat 13 and the first stationary ring 14, between the second stationary ring seat 15 and the inner wall of the shell 3, between the second stationary ring seat 15 and the first stationary ring seat 13, between the second stationary ring seat 15 and the second stationary ring 16, between the movable ring seat 11 and the screw rotating shaft 4, between the movable ring seat 11 and the movable sealing element 21, and between the movable ring seat 11 and the movable ring 12.

As can be seen from the above description, the sealing performance of the mechanical sealing structure is further enhanced by the arrangement of the sealing ring.

Furthermore, anti-rotation pins 18 are arranged between the movable ring seat 11 and the screw spindle 4, between the second stationary ring seat 15 and the inner wall of the housing 3, and between the movable ring seat 11 and the movable ring 12.

As can be seen from the above description, by the provision of the rotation preventing pin, displacement between the parts fixedly connected to each other due to movement of the screw device is prevented, and the reliability of the sealing structure is further improved.

Furthermore, one side of the movable ring 12 is abutted against the movable ring seat 11, and the other side is provided with a retaining ring 121, and the retaining ring 121 is locked on the movable ring seat 11 through a set screw.

From the above description, through the arrangement of the retainer ring, the moving ring is prevented from laterally moving on the spiral rotating shaft, and the reliability of the sealing structure is enhanced.

Further, the bottom surface of the second stationary ring seat 15, the side surfaces of the first stationary ring 14 and the second stationary ring 16, and the top surface of the movable ring 12 form a sealed cavity together, a filling hole 153 is formed in the second stationary ring seat 15, one end of the filling hole 153 penetrates through the shell 3 to be communicated with the external environment, and the other end of the filling hole 153 is communicated with the sealed cavity.

as can be seen from the above description, through filling the setting of annotating the hole, can fill into the stopper liquid to the sealed intracavity, the existing sealed effect of stopper liquid that has certain pressure in the sealed intracavity has, and has the effect of lubrication, cooling.

Furthermore, be equipped with drainage hole 133 on the first stationary ring seat 13, drainage hole 133 one end is passed casing 3 and is linked together with the external environment, and the other end communicates the cavity between first stationary ring seat 13 and the rotating ring seat 11.

As can be seen from the above description, through the arrangement of the drainage holes, when the mechanical seal portion, the non-contact seal portion or other seal ring is damaged, which component needs to be replaced can be determined according to the medium (blocking liquid, oil or steam) discharged from the drainage holes.