Novel medium-pressure combined steam valve
By setting up a filter and a second pressure reduction structure in the medium-pressure combined steam valve, the two pressure reduction of steam is achieved, which solves the problem of insufficient regulation capacity of the existing medium-pressure combined steam valve, and improves the deep peak regulating and steam supply guarantee capabilities of thermal power units.
Patent Information
- Application Number
- CN202510131188.1
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-02-06
- Publication Date
- 2025-05-13
AI Technical Summary
During the low-load pressure holding process of thermal power unit, the pressure difference between front and rear valves has small changes and limited adjustment capacity, making it difficult to effectively solve the contradiction between deep peak shaving of thermal power unit and steam supply guarantee.
A new medium-pressure combined steam valve is designed. By setting a filter and a second pressure reduction structure in the valve shell, the steam entering from the inlet passes through the filter and the second pressure reduction structure to achieve two pressure reductions, increasing the pressure difference between front and rear of the valve and improving the adjustment capacity.
By increasing the front and rear pressure difference between the valve, the adjustment capacity of the medium-pressure combined steam valve can be greatly improved, and the continuous adjustment of the inlet pressure and flow rate in different working conditions can be met, the stability of the steam supply pressure and flow rate can be ensured, and the contradiction between deep peak shaving of the thermal power unit and the steam supply guarantee can be solved.
Smart Images
Figure CN119982976A_ABST
Abstract
Description
Technical Field
[0001] The invention relates to the technical field of steam turbine combined steam valves, in particular to a novel medium-pressure combined steam valve. Background Art
[0002] With the explosive growth of renewable energy installed capacity, in order to further improve the level of new energy consumption, the peak-shaving demand of the power system is increasing, which makes thermal power units gradually change from the main position to the regulating power source in the power system. In order to ensure the safe and stable operation of the power system, thermal power units need to undertake frequent peak-shaving tasks of the power system. When thermal power units participate in deep peak-shaving, units with industrial steam demand need to continuously and stably provide steam according to the requirements of relevant steam-using enterprises; when the units are running at medium and low loads, medium-pressure joint steam valves are required to participate in regulating the appropriate pressure to ensure the parameters of industrial steam.
[0003] At present, during the pressure holding process of the medium-pressure combined steam valve at medium and low loads of the unit, the pressure difference before and after the valve changes little due to the valve's own structure and the critical pressure ratio of superheated steam. The adjustment capacity of the medium-pressure combined steam valve is very limited, making it difficult to effectively resolve the contradiction between deep peak regulation and steam supply guarantee of thermal power units. Summary of the invention
[0004] The purpose of the present invention is to provide a new medium-pressure combined steam valve that increases the pressure difference before and after the valve, greatly increases the adjustment capacity of the medium-pressure combined steam valve, and solves the contradiction between deep peak regulation and steam supply guarantee of thermal power units in view of the shortcomings of the existing technology.
[0005] The technical purpose of the present invention is achieved by the following technical solutions: A novel medium-pressure combined steam valve comprises a valve housing and a valve cover mounted on the upper end of the valve housing, wherein the valve housing is provided with a steam inlet and a steam outlet; a valve disc sleeve is provided at the lower end of the valve cover corresponding to the valve seat in the valve housing, a filter screen is provided in the valve housing and sleeved on the outside of the valve disc sleeve, and the lower side of the filter screen corresponds to the steam inlet; a secondary pressure reduction structure is provided at the lower end of the valve disc sleeve and the upper end of the valve seat; the steam entering from the steam inlet is pressure-reduced twice through the filter screen and the secondary pressure reduction structure.
[0006] Preferably, the second pressure reduction structure is a cylinder with through holes evenly distributed around the circumference; the diameter of the cylinder is equivalent to the diameter of the valve disc sleeve, and the upper and lower ends of the cylinder are respectively connected to or abut the lower end of the valve disc sleeve and the upper end of the valve seat.
[0007] Preferably, the second pressure reduction structure is arranged corresponding to the steam inlet.
[0008] Preferably, the height of the second pressure reduction structure is less than or equal to the height of the steam inlet.
[0009] Preferably, the lower end of the valve disc sleeve is fixedly connected to the upper end of the cylinder; the lower end of the cylinder abuts against the upper end of the valve seat.
[0010] Preferably, the second pressure reduction capacity of the second pressure reduction structure = specification of the through hole of the cylinder × fluid property × pressure drop correction coefficient; Among them, the specifications of the through holes of the cylinder are directly related to the through hole diameter, number, and hole length; Fluid properties: directly related to fluid density, flow rate, viscosity, and flow velocity; Pressure drop correction factor: refers to the coefficient used to correct the difference between the pressure drop under actual working conditions and the pressure drop under ideal conditions.
[0011] Preferably, a valve seat mounting groove is provided in the valve housing; the lower end of the filter screen is connected to the valve seat mounting groove, and the upper end thereof is close to the lower end of the valve cover and is detachably connected to the valve disc sleeve.
[0012] Compared with the prior art, the present invention has the following beneficial effects: The valve housing of the present invention is provided with a filter screen which is sleeved on the outside of the valve disc sleeve, and the lower side of the filter screen corresponds to the steam inlet; a second pressure reduction structure is provided between the lower end of the valve disc sleeve and the upper end of the valve seat; the steam entering from the steam inlet is reduced in pressure twice through the filter screen and the second pressure reduction structure. The present invention has the advantages of increasing the pressure difference before and after the valve, greatly increasing the regulating capacity of the medium-pressure combined steam valve, being able to continuously adjust the steam inlet pressure and flow rate to meet different working conditions, and ensuring the stability of the external steam supply pressure and flow rate, thereby resolving the contradiction between deep peak regulation and steam supply guarantee of thermal power units. BRIEF DESCRIPTION OF THE DRAWINGS
[0013] Figure 1 is an assembly diagram of the present invention; Reference numerals: 1—valve housing; 11—steam inlet; 12—valve seat mounting groove; 13—valve seat; 2—valve cover; 3—valve disc sleeve; 4—Filter; 5—cylinder; 51—through hole; 6—Medium-pressure main steam valve stem; 7—Medium-pressure regulating valve stem. DETAILED DESCRIPTION
[0014] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Generally, the components of the embodiments of the present invention described and shown in the drawings here can be arranged and designed in various different configurations.
[0015] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the invention claimed for protection, but merely represents selected embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.
[0016] It should be noted that similar reference numerals and letters represent similar items in the following drawings, so once an item is defined in one drawing, it does not need to be further defined and explained in the subsequent drawings. In addition, the terms "first", "second", etc. are only used to distinguish the description and cannot be understood as indicating or implying relative importance.
[0017] like Figure 1 As shown, a new type of medium-pressure combined steam valve comprises a valve housing 1, a valve cover 2 mounted on the upper end of the valve housing 1, and the valve housing 1 is provided with a steam inlet 11 and a steam outlet; the lower end of the valve cover 2 is provided with a valve disc sleeve 3 corresponding to the valve seat 13 in the valve housing 1; a filter screen 4 is sleeved on the outside of the valve disc sleeve 3 in the valve housing 1, and the lower side of the filter screen 4 corresponds to the steam inlet 11; a second pressure reduction structure is provided between the lower end of the valve disc sleeve 3 and the upper end of the valve seat 13; the steam entering from the steam inlet 11 is reduced in pressure twice through the filter screen 4 and the second pressure reduction structure. In actual use, the steam flowing in from the steam inlet 11 is reduced in pressure for the first time through the filter screen 4, and the steam after the first pressure reduction is reduced in pressure for the second time through the second pressure reduction structure. The adoption of this technical measure has the advantages of increasing the pressure difference before and after the valve, greatly increasing the adjustment capacity of the medium-pressure combined steam valve; it can continuously adjust the steam inlet pressure and flow to meet different working conditions, ensure the stability of the external steam supply pressure and flow, and thus solve the contradiction between the deep peak regulation and steam supply guarantee of the thermal power unit.
[0018] like Figure 1 As shown, the valve housing 1 has an air flow channel, and the valve housing 1 is provided with a steam inlet 11 and a steam outlet; the steam inlet 11 is arranged at the middle of the left side of the valve housing 1, and the steam outlet is arranged at the lower right side of the valve housing 1. Since the steam outlet and the exhaust port are not in the same plane, Figure 1 The steam outlet is not directly shown. Figure 1 The position of the center line of the middle exhaust port is the setting position of the exhaust port.
[0019] The valve cover 2 is assembled on the upper end of the valve housing 1, and the medium-pressure main steam valve stem 6 is vertically slidably mounted on the valve cover 2 and extends into the valve housing 1 to connect with the main steam valve core component (not shown in the figure) in the valve housing 1. Corresponding to the valve cover 2, the medium-pressure regulating valve stem 7 is mounted on the lower end of the valve housing 1 and extends into the valve housing 1 to connect with the regulating valve core component (not shown in the figure) in the valve housing 1. The medium-pressure regulating valve stem 7 and the regulating valve core component are on the same vertical axis as the medium-pressure main steam valve stem 6 and the valve core component. The diameter of the main steam valve core component and the regulating valve core component are smaller than the valve disc sleeve 3, and the diameter of the regulating valve core component is larger than the opening width of the valve seat 13. The main steam valve core component and the regulating valve core component move vertically in the valve disc sleeve 3 through the medium-pressure main steam valve stem 6 and the medium-pressure regulating valve stem 7, respectively.
[0020] A valve seat mounting groove 12 is provided in the valve housing 1; the lower end of the filter screen 4 is connected to the valve seat mounting groove 12, and the upper end thereof is close to the lower end of the valve cover 2 and is detachably connected to the valve disc sleeve 3. In a specific implementation, the height of the chamber near the valve seat 13 in the valve housing 1 is greater than the height of the steam inlet 11; the height of the filter screen 4 is less than or equal to the height from the upper side of the valve seat mounting groove 12 to the lower end of the valve cover 2. The diameter of the filter screen 4 is larger than the valve disc sleeve 3, and it is sleeved on the outside of the valve disc sleeve 3. A connecting portion extending toward the filter screen 4 is provided on the upper end of the valve disc sleeve 3 facing the filter screen 4, and the upper end of the valve disc sleeve 3 is pin-connected to the filter screen 4 through the connecting portion; the upper end of the valve disc sleeve 3 is fixedly connected to the valve cover 2 on the side away from the filter screen 4.
[0021] The second pressure reduction structure is a cylinder 5 with through holes 51 evenly distributed around the circumference; the diameter of the cylinder 5 is equivalent to the diameter of the valve disc sleeve 3, and the upper and lower ends of the cylinder 5 are respectively connected or abutted against the lower end of the valve disc sleeve 3 and the upper end of the valve seat 13. This technical measure has the advantages of simple structure and low manufacturing cost.
[0022] The second pressure reduction structure is arranged corresponding to the steam inlet 11. In implementation, the height of the second pressure reduction structure is less than or equal to the height of the steam inlet 11. If the second pressure reduction structure is arranged on the upper side of the steam inlet 11, steam flow excitation may occur, which may cause problems such as valve vibration. The second pressure reduction structure is arranged corresponding to the steam inlet 11 to avoid steam flow excitation, which may cause problems such as valve vibration. In specific implementation, the cylinder 5 is arranged corresponding to the steam inlet 11, and the height of the cylinder 5 is less than or equal to the height of the steam inlet 11.
[0023] The lower end of the valve disc sleeve 3 is fixedly connected to the upper end of the cylinder 5; the lower end of the cylinder 5 abuts the upper end of the valve seat 13. In the specific implementation, the cylinder 5 is arranged between the valve disc sleeve 3 and the valve seat 13. When the valve disc sleeve 3 and the cylinder 5 are arranged separately, the strength and position of the cylinder 5 are not guaranteed. The lower end of the cylinder 5 is installed on the valve seat 13, and the upper end of the cylinder 5 abuts the lower end of the valve disc sleeve 3. The cylinder 5 and the filter screen 4 are arranged at intervals, and there is space for steam flow between the two. During installation and use, it is necessary to align the upper end of the second pressure reduction structure with the lower end of the valve disc sleeve 3, and it is also necessary to ensure the distance between the second pressure reduction structure and the filter screen 4, resulting in the strength and position of the second pressure reduction structure. The lower end of the valve disc sleeve 3 is fixedly connected to the upper end of the cylinder 5, so that the two form an integrated structure to obtain better strength. At the same time, the position of the valve disc sleeve 3 is fixed on the valve cover 2, and its position is stable. The spacing distance between the cylinder 5 and the filter screen 4 can be guaranteed. The adoption of this technical measure can ensure the strength and position of the second pressure reduction structure, and ensure the distance between the second pressure reduction structure and the filter 4.
[0024] In specific implementation, the second pressure reduction capacity of the second pressure reduction structure will be affected by many factors, including the specifications of the through holes 51 of the cylinder 5, the fluid properties and the pressure drop correction factor. The specifications of the through holes 51 of the cylinder 5 are directly related to the diameter, number and length of the through holes 51; Fluid properties: directly related to fluid density, flow rate, viscosity, and flow velocity; Pressure drop correction factor: refers to the coefficient used to correct the difference between the pressure drop under actual working conditions and the pressure drop under ideal conditions.
[0025] The second pressure reduction capacity of the second pressure reduction structure is obtained by the following formula: The second pressure reduction capacity of the second pressure reduction structure = the specification of the through hole 51 of the cylinder 5 × the fluid property × the pressure drop correction coefficient.
[0026] The technical solutions provided by the embodiments of the present invention are introduced in detail above. Specific examples are used herein to illustrate the principles and implementation methods of the embodiments of the present invention. The description of the above embodiments is only applicable to help understand the principles of the embodiments of the present invention. At the same time, for those skilled in the art, according to the embodiments of the present invention, there will be changes in the specific implementation methods and application scopes. In summary, the content of this specification should not be understood as limiting the present invention.
Claims
1. A novel medium-pressure combined steam valve, comprising a valve housing and a valve cover mounted on the upper end of the valve housing, wherein the valve housing is provided with a steam inlet and a steam outlet; a valve disc sleeve is provided at the lower end of the valve cover corresponding to the valve seat in the valve housing, characterized in that: The valve housing is provided with a filter screen sleeved on the outside of the valve disc sleeve, and the lower side of the filter screen corresponds to the steam inlet; the lower end of the valve disc sleeve and the upper end of the valve seat are provided with a secondary pressure reduction structure; the steam entering from the steam inlet is reduced in pressure twice through the filter screen and the secondary pressure reduction structure.
2. The novel medium-pressure combined steam valve according to claim 1 is characterized in that: The second pressure reduction structure is a cylinder with through holes evenly distributed around the circumference; the diameter of the cylinder is equivalent to the diameter of the valve disc sleeve, and the upper and lower ends of the cylinder are respectively connected to or abut the lower end of the valve disc sleeve and the upper end of the valve seat.
3. The novel medium-pressure combined steam valve according to claim 1 or 2 is characterized in that: The second pressure reduction structure is arranged corresponding to the steam inlet.
4. The novel medium-pressure combined steam valve according to claim 3 is characterized in that: The height of the second pressure reduction structure is less than or equal to the height of the steam inlet.
5. The novel medium-pressure combined steam valve according to claim 2 is characterized in that: The lower end of the valve disc sleeve is fixedly connected to the upper end of the cylinder; the lower end of the cylinder abuts against the upper end of the valve seat.
6. The novel medium-pressure combined steam valve according to claim 1 is characterized in that: The second pressure reduction capacity of the second pressure reduction structure = specification of the through hole of the cylinder × fluid property × pressure drop correction coefficient; Among them, the specifications of the through holes of the cylinder are directly related to the through hole diameter, number, and hole length; Fluid properties: directly related to fluid density, flow rate, viscosity, and flow velocity; Pressure drop correction factor: refers to the coefficient used to correct the difference between the pressure drop under actual working conditions and the pressure drop under ideal conditions.
7. The novel medium-pressure combined steam valve according to claim 1 is characterized in that: A valve seat installation groove is arranged in the valve housing; the lower end of the filter screen is connected to the valve seat installation groove, and the upper end thereof is close to the lower end of the valve cover and is detachably connected to the valve disc sleeve.