Water vapor compressor
By using a single-ended dry air-sealing unit and a front-mounted carbon ring unit in the water vapor compressor, combining micron-scale fluid dynamic pressure tank and split-flap carbon ring, the leakage and high cost problems in the existing sealing technology are solved, and the problem of high costs is achieved. Low leakage and efficient sealing effect, simplifying the structure and reducing operating costs.
Patent Information
- Application Number
- CN202323604368.2
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2023-12-28
- Publication Date
- 2024-12-10
- Estimated Expiration
- 2033-12-28
AI Technical Summary
The sealing technology of existing water vapor compressors has leakage problems, especially under negative pressure conditions, when external air inflow affects the vacuum degree and water vapor purity of the compressor, and the existing sealing solution is costly and complex in operation.
A single-ended dry air-sealing unit is adopted, combined with a front carbon ring unit, and sealing is achieved through micron-scale fluid dynamic pressure grooves and split-flap carbon rings, simplifying the structure, reducing costs, and improving sealing performance.
It realizes low leakage and efficient sealing, reduces the operating cost of water vapor compressors, ensures stable operation of sealing for a long period of time, and effectively isolates water vapor from the atmospheric environment.
Smart Images
Figure CN222141590U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the technical field of mechanical seals, in particular to a water vapor compressor. Background Art
[0002] In general, the pressure at the inlet and outlet of water vapor compressors, such as screw compressors and centrifugal compressors, is very different. The inlet pressure is generally negative (i.e., less than atmospheric pressure), and the outlet pressure is positive high pressure. At present, carbon ring seals, double-end mechanical seals or double-end dry gas seals are often used for the shaft end seals of water vapor compressors.
[0003] When carbon ring seals are used as axial seals, since carbon ring seals are radial non-contact gap seals, when the sealing pressure is positive, the water vapor in the sealing cavity leaks through the carbon ring; when the sealing pressure is negative, especially at the inlet end of the compressor, the air from the external environment will enter the machine through the radial gap of the carbon ring, affecting the inlet vacuum of the compressor and the purity of the water vapor. When double-end mechanical seals are used, auxiliary systems need to be configured to provide continuous lubrication and cooling media for the inner and outer mechanical seal friction pair end faces; moreover, double-end mechanical seals together with the configured sealing auxiliary system are often expensive, and the on-site operation is relatively cumbersome. The use of double-face dry gas seals requires an auxiliary system to provide continuous gas lubrication for the inner and outer dry gas seal friction pairs. Moreover, inert gas nitrogen is generally used as the sealing gas source. A small amount of nitrogen will enter the compressor through the inner sealing end face, thereby contaminating the water vapor. In addition, double-face dry gas seals together with the configured dry gas seal auxiliary system are often expensive and the on-site operation is cumbersome. Utility Model Content
[0004] The purpose of this utility model is to overcome the defects of the prior art.
[0005] In order to achieve the purpose of the utility model, the present application provides the following technical solutions.
[0006] In a first aspect, the present application provides a water vapor compressor, wherein both the inlet and outlet ends of the water vapor compressor are provided with shaft end sealing devices, wherein the shaft end sealing devices at the inlet and outlet ends each include a single-end dry gas sealing unit, and the shaft end sealing device at the inlet end includes a front carbon ring unit, and the front carbon ring unit is arranged at one end on the medium side of the single-end dry gas sealing unit.
[0007] In one embodiment of the first aspect, the dry gas sealing unit includes a sleeve, an end cover, a dynamic ring and a static ring, wherein the sleeve is fixed on the main shaft of the steam compressor, the end cover is fixed on the casing of the steam compressor, the dynamic ring is fixed on the sleeve through a clamping sleeve, the static ring is fixed on the end cover, and the static ring and the dynamic ring abut against each other to form a sealing surface.
[0008] In an implementation manner of the first aspect, a transmission sleeve is provided on the outer side of one end of the shaft sleeve, and the transmission sleeve and the shaft sleeve are fixed to the main shaft by means of a jackscrew.
[0009] In one implementation of the first aspect, the end cover is fixed to the casing of the water vapor compressor by screws, and a throttling bushing is provided between the inner wall of the end cover and the shaft sleeve.
[0010] In an implementation of the first aspect, a first radial step is provided on an outer wall of the middle portion of the sleeve, a compression sleeve is fixed to the front end of the sleeve by screws, and the dynamic ring is clamped between the first step and the compression sleeve.
[0011] In an implementation manner of the first aspect, an axial anti-rotation pin is provided between the stationary ring and the end cover, and a spring is provided between the stationary ring and the end cover.
[0012] In one implementation of the first aspect, a micrometer-sized fluid dynamic pressure groove is provided on the contact surface of the dynamic ring abutting against the static ring.
[0013] In one embodiment of the first aspect, the front carbon ring unit includes a carbon ring seat, a carbon ring and a pressure cover, wherein the pressure cover is sleeved on the outside of the main shaft and fixed to the end cover by screws, the inner wall of the end cover is provided with a second step, the front and rear ends of the carbon ring seat are respectively abutted by the pressure cover and the second step, the carbon ring sleeve is arranged on the outside of the clamping sleeve, and the carbon ring is fixed to the carbon ring seat.
[0014] In one embodiment of the first aspect, the carbon ring is a split-petal carbon ring, comprising a plurality of carbon ring sheets, all of which are in contact with each other and arranged on the outside of the compression sleeve, each carbon ring sheet is fixed to the carbon ring seat by an anti-rotation pin, and all the carbon ring sheets are tightened by an outer tension spring and fit against the outer wall of the compression sleeve.
[0015] Compared with the prior art, the beneficial effects of the present invention are:
[0016] (1) Since the medium of the water vapor compressor is water, which is generally relatively clean, the present application directly adopts a single-end dry gas seal to achieve sealing. The entire sealing device is very simple and the cost is lower than several existing sealing solutions;
[0017] (2) It can ensure the long-term stable operation of the seal, and at the same time effectively isolate the water vapor inside the machine from the atmosphere, so that the amount of water vapor leaking into the atmosphere through the seal end face is extremely low;
[0018] (3) In view of the situation where a negative pressure medium is present at the inlet end of the water vapor compressor, the present application sets a front carbon ring in front of the dry gas seal at the inlet end, and draws air from the outlet of the unit into the space between the front carbon ring seal and the dry gas seal to increase the sealing chamber pressure at the inlet end and ensure the sealing performance. BRIEF DESCRIPTION OF THE DRAWINGS
[0019] Figure 1 It is a schematic diagram of the mechanical seal structure at the outlet of the water vapor compressor;
[0020] Figure 2 Schematic diagram of the mechanical seal structure at the inlet end of the steam compressor.
[0021] In the accompanying drawings, 1 is a shaft sleeve, 2 is a moving ring, 3 is an end cover, 4 is an O-ring, 5 is a compression sleeve, 6 is an O-ring, 7 is a top screw, 8 is a connecting screw, 9 is a stationary ring, 10 is a push ring, 11 is a retaining ring, 12 is an anti-rotation pin, 13 is a spring, 14 is an O-ring, 15 is a positioning plate, 16 is a connecting screw, 17 is a throttling bushing, 18 is an O-ring, 19 is a screw, 20 is a transmission sleeve, 21 is a carbon ring seat, 22 is a pressure cover, 23 is a carbon ring, 24 is a screw, 25 is an anti-rotation pin, 26 is an O-ring, 27 is a tension spring, 28 is a screw, 29 is an O-ring, 30 is a first step, and 31 is a second step. DETAILED DESCRIPTION
[0022] Unless otherwise defined, the technical terms or scientific terms used in this specification and claims shall have the ordinary meanings understood by persons with ordinary skills in the technical field to which the utility model belongs. All the values from the lowest value to the highest value listed in this article refer to all the values obtained by incrementing one unit between the lowest value and the highest value when the difference between the lowest value and the highest value is more than two units.
[0023] The following will describe the specific implementation of the utility model. It should be noted that in the specific description of these implementations, in order to provide a concise description, this specification cannot provide a detailed description of all the features of the actual implementation. Without departing from the spirit and scope of the utility model, those skilled in the art may modify and replace the implementation of the utility model, and the resulting implementation is also within the scope of protection of the utility model.
[0024] This patent proposes a water vapor compressor, the main core of which is the sealing device at the compressor medium inlet and medium outlet. It has a simple structure and does not require a special dry gas sealing auxiliary system. The sealing device consists of a rotating component and a stationary component. The rotating component consists of a moving ring, a sleeve, a compression sleeve, a transmission sleeve, a top screw, a connecting screw, a sealing ring, etc.; a fluid dynamic pressure groove is provided on the sealing end face of the moving ring, and the fluid dynamic pressure groove is arranged at the outer diameter of the sealing end face. The stationary component consists of a stationary ring, a spring, a push ring, an auxiliary sealing ring, an end cover, an anti-rotation pin, etc. When pre-installed or not under pressure, the axial compression force of the spring is relied on to make the sealing end faces of the stationary ring and the moving ring axially fit; when the unit is in a shutdown state after air intake, the dry gas seal is compressed, and under the joint action of the spring and the medium pressure, the end face of the stationary ring is kept in close contact with the moving ring to achieve static sealing of the sealing end face. After the unit is started, the moving ring relies on the axial compression of the compression sleeve and the sleeve metal parts to transmit torque, so that the moving ring rotates at high speed with the shaft. After the moving ring rotates at high speed, the pumping effect of the micron-scale fluid dynamic pressure groove etched on the outer diameter of the moving ring end face is used to suck the water vapor at the outer diameter into the sealing end face between the moving ring and the static ring. The fluid dynamic pressure effect is used to form a micron-scale air film between the sealing end faces, which plays a role in lubrication and isolation of the sealing end faces, and realizes the non-contact operation of the seal. Due to the high speed of the compressor, the rigidity of this extremely thin air film on the sealing end face is very large, which can ensure the long-term stable operation of the seal; at the same time, it can effectively isolate the water vapor in the machine from the atmospheric environment, so that the amount of water vapor leaking into the atmospheric environment through the sealing end face is extremely low. In addition, since the working medium of general water vapor compressors - water vapor is relatively clean, as long as the quality of water vapor meets the corresponding power plant steam quality standards, there is usually no need for a special dry gas seal auxiliary system to provide filtering, pressure control and flow regulation functions for the sealing gas. Therefore, the entire sealing device is very simple and the cost is lower than other sealing solutions. In order to prevent the water vapor from precipitating into liquid water on the dry gas seal end face, it is necessary to keep the temperature of the water vapor at the compressor outlet higher than its dew point temperature by 15-28°C, depending on the water vapor pressure.
[0025] In addition, since the inlet of the water vapor compressor is at negative pressure, in order to prevent the occurrence of back pressure in the dry gas seal at the inlet end, the present application sets a pre-carbon ring in front of the dry gas seal at the inlet end, and draws air from the unit outlet into the space between the pre-carbon ring seal and the dry gas seal to increase the sealing chamber pressure at the inlet end.
[0026] Example
[0027] The following is a detailed description of an embodiment of the present invention. This embodiment is implemented based on the technical solution of the present invention, and a detailed implementation method and a specific operation process are given, but the protection scope of the present invention is not limited to the following embodiment.
[0028] Example 1
[0029] A water vapor compressor is provided with a medium inlet and a medium outlet at both ends of the water vapor compressor, and a sealing device is provided at the medium inlet and the medium outlet, wherein the sealing device at the medium outlet end is as follows Figure 1 As shown, the sealing device at the medium inlet end is as follows Figure 2 shown.
[0030] Both the media inlet and outlet contain a single-end dry gas seal unit with similar structure. Figure 1 or Figure 2 As shown in the right part of the figure, the difference between the two is that the shape of the end cover 3 is slightly different, because in the sealing device at the medium inlet end, the end cover 3 also needs to be installed with a front carbon ring 23 unit. Therefore, the axial length of the end cover 3 at the medium inlet end is larger, and there is an additional O-ring 26 between the end cover 3 and the compressor casing. The rest of the structure is the same. The details are as follows:
[0031] The dry gas sealing unit comprises a sleeve 1, an end cover 3, a dynamic ring 2 and a static ring 9, wherein the sleeve 1 is sleeved on the main shaft of the water vapor compressor, and an O-ring 6 is arranged between the two. A transmission sleeve 20 is arranged on the outer side of one end of the sleeve 1, and the transmission sleeve 20 and the sleeve 1 are fixed to the main shaft through a top screw 7. The end cover 3 is fixed to the casing of the water vapor compressor through a connecting screw 16, and an O-ring 18 is arranged between the two. A throttling bushing 17 is arranged between the inner wall of the end cover 3 and the sleeve 1. A radial first step 30 is arranged on the outer wall of the middle part of the sleeve 1, and a compression sleeve 5 is fixed to the front end of the sleeve 1 (the left side in the figure) through a screw 19 or a screw 28 (the screw 19 is suitable for the medium outlet end, and the screw 28 is suitable for the medium inlet end), the dynamic ring 2 is clamped between the first step 30 and the compression sleeve 5, and an O-ring 4 is arranged between the dynamic ring 2 and the sleeve 1. The stationary ring 9 is fixed on the end cover 3 by the anti-rotation pin 12. A spring 13 and a push ring 10 are arranged between the end cover 3 and the stationary ring 9, wherein the front end of the push ring 10 abuts against the rear end of the stationary ring 9, and the rear end of the push ring 10 abuts against the spring 13. An O-ring 14 is also arranged between the stationary ring 9 and the push ring 10, and the O-ring 14 is sleeved on the end cover 3. A micron-level fluid dynamic pressure groove is arranged on the tail end face of the dynamic pressure groove, and the depth of the dynamic pressure groove is generally 1 to 100 μm, and the tail end face of the dynamic ring is in contact with the front end face of the stationary ring 9 to form a sealing surface. In addition, a positioning plate 15 is fixed at the tail end of the end cover 3 by the connecting screw 8 to assemble the rotating part and the stationary part of the dry gas seal into a whole, so as to ensure that the spring is at the correct working height after the seal is installed. A clamping ring is also provided on the end cover 3 to limit the static ring 9 and prevent the static ring 9 from excessively moving to the front end due to the elastic force of the spring 13 when the static ring 9 is installed, thereby affecting the installation of the dynamic ring 2.
[0032] In the sealing device at the medium inlet end, in addition to the above-mentioned single-end dry gas sealing unit, a front carbon ring 23 unit is also included, which includes a carbon ring seat 21, a carbon ring 23 and a gland 22, wherein the gland 22 is sleeved on the outside of the main shaft and fixed to the end cover 3 by screws 24, and an O-ring 26 is provided between the gland 22 and the end cover 3, and a second step 31 is provided on the inner wall of the end cover 3, and the front and rear ends of the carbon ring seat 21 are respectively abutted by the gland 22 and the second step 31, and the carbon ring 23 is sleeved on the outside of the compression sleeve 5, and the carbon ring 23 is fixed to the carbon ring seat 21 by an anti-rotation pin 25. The carbon ring 23 is a split-petal carbon ring 23, including multiple carbon ring pieces, all of which abut against each other and are arranged on the outside of the compression sleeve 5, each of which is fixed to the carbon ring seat 21 by an anti-rotation pin, and all of which are clamped and fit to the outer wall of the compression sleeve 5 by an outer tension spring 27.
[0033] The above description of the embodiments is to facilitate those of ordinary skill in the art to understand and apply the present application. It is obvious that those familiar with the art can easily make various modifications to these embodiments and apply the general principles described herein to other embodiments without having to pay creative labor. Therefore, the present application is not limited to the embodiments herein, and improvements and modifications made by those skilled in the art based on the contents disclosed in the present application without departing from the scope and spirit of the present application are within the scope of the present application.
Claims
1. A water vapor compressor, wherein both the inlet and outlet ends of the water vapor compressor are provided with shaft end sealing devices, characterized in that: The shaft end sealing devices at the inlet end and the outlet end each include a single-end dry gas sealing unit, and the dry gas sealing unit includes a shaft sleeve, an end cover, a dynamic ring and a static ring, wherein a transmission sleeve is provided on the outer side of one end of the shaft sleeve, the transmission sleeve and the shaft sleeve are fixed to the main shaft by a top screw, the end cover is fixed to the casing of the water vapor compressor by screws, a throttling bushing is provided between the inner wall of the end cover and the shaft sleeve, the dynamic ring is fixed to the shaft sleeve by a clamping sleeve, the static ring is fixed to the end cover, the static ring and the dynamic ring abut against each other and form a sealing surface, and the shaft end sealing device at the inlet end includes a front carbon ring unit, and the front carbon ring unit is arranged at one end on the medium side of the single-end dry gas sealing unit.
2. The water vapor compressor according to claim 1, characterized in that: The outer wall of the middle part of the sleeve is provided with a radial first step, the front end of the sleeve is fixed with a compression sleeve by screws, and the dynamic ring is clamped between the first step and the compression sleeve.
3. The water vapor compressor according to claim 1, characterized in that: An axial anti-rotation pin is arranged between the stationary ring and the end cover, and a spring is arranged between the stationary ring and the end cover.
4. The water vapor compressor according to claim 1, characterized in that: A micron-sized fluid dynamic pressure groove is provided on the contact surface of the dynamic ring that abuts against the static ring.
5. The water vapor compressor according to claim 1, characterized in that: The front carbon ring unit includes a carbon ring seat, a carbon ring and a pressure cover, wherein the pressure cover is sleeved on the outside of the main shaft and fixed to the end cover by screws, the inner wall of the end cover is provided with a second step, the front and rear ends of the carbon ring seat are respectively abutted by the pressure cover and the second step, the carbon ring sleeve is arranged on the outside of the compression sleeve, and the carbon ring is fixed to the carbon ring seat.
6. The water vapor compressor according to claim 5, characterized in that: The carbon ring is a split-petal carbon ring, comprising a plurality of carbon ring pieces, all of which are in contact with each other and arranged on the outside of the compression sleeve, each carbon ring piece is fixed to the carbon ring seat by an anti-rotation pin, and all the carbon ring pieces are tightened by an outer tension spring and fit against the outer wall of the compression sleeve.