Steam turbine with steam supplementing valve for wide-load adjustment and adjustment method of steam turbine
By adopting the design with steam filling valve and multi-stage small enthalpy drop reaction flow technology in the turbine, the problem of variable power performance in a wide load area is solved, and the efficient operation and large overload capacity of the turbine are achieved.
Patent Information
- Application Number
- CN202310780036.5
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2023-06-29
- Publication Date
- 2024-12-31
AI Technical Summary
The prior art is difficult to effectively adjust variable power performance in the wide load area of the turbine, and cannot meet the needs of long-term ultra-low loads and large overload loads.
The steam turbine design is adopted with a steam filling valve. The combination of the main steam valve, the first regulating valve, the second regulating valve and the steam filling valve is combined with the reflux arrangement of the medium and low pressure cylinders to achieve the multi-stage small enthalpy of steam. Reduce the reaction flow, use the steam filling valve to participate in load regulation from an extremely low load, adjust the opening of the first regulating valve, the second regulating valve and the steam filling valve, and expand the efficient operating range of the turbine.
It realizes efficient operation of the turbine in a wide load area, has long-term ultra-low load and large overload load capabilities, meets the requirements of variable power performance, and improves the economic and response speed of the unit.
Smart Images
Figure CN119222008A_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to the technical field of steam turbines, and in particular to a steam turbine with a supplementary steam valve for wide load regulation and a regulation method for the steam turbine with a supplementary steam valve for wide load regulation. Background Art
[0002] At present, steam turbine power generation or power units have the demand for wide load operation. Steam turbines need to meet the requirements of long-term ultra-low load operation while having a large overload capacity, and they must be highly economical under these working conditions. In order to meet this goal, certain technologies need to be adopted in the adjustment method and machine design to achieve it.
[0003] The invention patent application with publication number CN114961887A discloses a primary frequency regulation method for a steam turbine with a supplementary steam valve, which opens the supplementary steam valve in the high-load section of the steam turbine. Specifically, when the steam turbine unit is operating in the medium and low load stages, the supplementary steam valve remains closed during the normal operation of the unit and the primary frequency regulation process; when the steam turbine unit is operating in the high load stage, the supplementary steam valve remains closed during the normal operation of the unit, and during the primary frequency regulation process, the supplementary steam valve is opened while increasing the opening of the high-pressure regulating valve, so that the supplementary steam valve participates in the primary frequency regulation. By having the supplementary steam valve participate in the regulation at the same time, the response speed of the primary frequency regulation is improved, the problem of small flow and slow response of the high-pressure regulating valve in the latter part of the valve opening is avoided, and the demand for fast response of the primary frequency regulation is met.
[0004] The invention patent application with publication number CN115163214A discloses a marine steam turbine regulating valve, which is composed of two groups of valves, and the marine steam turbine is regulated by the two groups of regulating valves. Specifically, according to the working characteristics of the steam turbine, the regulating valve can realize single valve control or double valve control through the actuator. When the steam turbine is running at a low working condition, single valve control can be performed, which is beneficial to noise control. When the steam turbine is running at a high working condition, double valve control can be performed, which is beneficial to reducing flow loss.
[0005] The invention patent application with publication number CN113339089A discloses a high-efficiency peak-shaving steam turbine system and its working method, which adjusts the steam turbine load by adjusting the high-pressure bypass and the heat recovery extraction steam. Specifically, the high-efficiency peak-shaving steam turbine system operates within the basic load and below, has high economy, and adopts the method of partially or completely shutting down the high-pressure heater or putting it into the high-pressure bypass of the steam turbine, which meets the large load or unit nameplate output required by the power grid.
[0006] The above-mentioned adjustment methods cannot adapt well to the performance requirements of variable power in a wide load range of the steam turbine. Summary of the invention
[0007] In view of the above-mentioned defects of the prior art, the technical problem to be solved by the present invention is to provide a steam turbine with wide load regulation of a supplementary steam valve and a regulation method of the steam turbine with wide load regulation of a supplementary steam valve, which can expand the range of efficient operation of the steam turbine and better adapt to the performance requirements of variable power in a wide load range.
[0008] In order to solve the above technical problems, the present invention adopts the following technical solutions:
[0009] The present invention provides a steam turbine with wide load regulation of a supplementary steam valve, comprising an intermediate pressure cylinder, a low pressure cylinder, a main steam valve, a first regulating valve, a second regulating valve and a supplementary steam valve. The steam source passes through the main steam valve and then enters the flow portion of the intermediate pressure cylinder through the first regulating valve and / or the second regulating valve to perform work. The exhaust steam of the intermediate pressure cylinder enters the flow portion of the low pressure cylinder through the low pressure steam inlet valve to perform work. The steam source enters the flow portion of the low pressure cylinder through the supplementary steam valve to perform work.
[0010] Preferably, the steam source passes through the main steam valve and then enters the flow part of the low-pressure cylinder through the supplementary steam valve to perform work.
[0011] Preferably, the flow-through portion of the medium-pressure cylinder and the flow-through portion of the low-pressure cylinder are arranged in a counter-flow manner.
[0012] Preferably, the main steam valve, the first regulating valve, the second regulating valve and the supplementary steam valve are all arranged at the top of the intermediate pressure cylinder, the first regulating valve and the second regulating valve are arranged on both sides of the intermediate pressure cylinder, and the supplementary steam valve is arranged between the first regulating valve and the second regulating valve.
[0013] Preferably, the main steam valve, the first regulating valve, the second regulating valve and the supplementary steam valve all adopt individually controllable oil motors.
[0014] The present invention also provides a steam turbine regulation method with wide load regulation of the supplementary steam valve as described above, wherein when the steam turbine unit starts to operate, the main steam valve, the first regulating valve and the low-pressure steam inlet valve are opened, and the second regulating valve and the supplementary steam valve are closed; as the unit load increases, the opening of the first regulating valve gradually increases; when the unit load reaches the first load, the supplementary steam valve is opened, and the opening of the supplementary steam valve gradually increases with the increase of the unit load; when the unit load reaches the second load, the supplementary steam valve maintains the current opening; when the unit load reaches the third load, the second regulating valve is opened, And the opening of the second regulating valve gradually increases with the increase of the random unit load, and the opening of the steam supply valve gradually decreases with the increase of the random unit load; when the unit load reaches the fourth load, the steam supply valve is closed; when the unit load reaches the rated load, the first regulating valve and the second regulating valve are fully opened, the steam supply valve is opened, and the opening of the steam supply valve gradually increases with the increase of the random unit load; when the unit load reaches the maximum load, the steam supply valve is fully opened; the first load, the second load, the third load and the fourth load increase in sequence and are all less than the rated load, and the maximum load is greater than the rated load.
[0015] Preferably, the first load is 9%-11% of the rated load, the second load is 12%-15% of the rated load, the third load is 59%-61% of the rated load, and the fourth load is 63%-65% of the rated load.
[0016] Preferably, the maximum load is 110% to 130% of the rated load.
[0017] The present invention further provides a regulation method for a steam turbine with wide load regulation of a supplementary steam valve as described above. When the steam turbine unit starts to operate, the main steam valve, the first regulating valve and the low-pressure steam inlet valve are opened, and the steam passes through the main steam valve and then through the first regulating valve into the flow portion of the intermediate pressure cylinder to provide a minimum cooling flow for the intermediate pressure cylinder; the supplementary steam valve is opened, and the steam passes through the supplementary steam valve into the flow portion of the low-pressure cylinder to perform work, and the opening of the supplementary steam valve gradually increases with the increase of the unit load.
[0018] The present invention further provides a regulation method for a steam turbine with wide load regulation of a supplementary steam valve as described above. When the steam turbine unit starts to operate, the main steam valve and the first regulating valve are opened, and the low-pressure steam inlet valve is closed. Steam passes through the main steam valve and then enters the flow part of the intermediate pressure cylinder through the first regulating valve to perform work, and the exhaust steam of the intermediate pressure cylinder is supplied to external users. The opening of the first regulating valve gradually increases with the increase of the unit load; the supplementary steam valve is opened, and the steam passes through the supplementary steam valve and enters the flow part of the low-pressure cylinder to provide a minimum cooling flow for the low-pressure cylinder.
[0019] Compared with the prior art, the present invention has significant improvements:
[0020] In the present invention, the supplementary steam valve participates in load regulation starting from an extremely low unit load, which can expand the range of efficient operation of the steam turbine unit. By adjusting the opening size of the first regulating valve, the second regulating valve and the supplementary steam valve, full-load efficient operation of the steam turbine unit can be achieved, that is, long-term ultra-low load operation is achieved with a large overload capacity, thereby better adapting to the performance requirements of variable power in a wide load range. BRIEF DESCRIPTION OF THE DRAWINGS
[0021] Figure 1 It is a structural schematic diagram of an implementation mode of a steam turbine with a supplementary steam valve for wide load regulation according to the first embodiment of the present invention.
[0022] Figure 2 It is a structural schematic diagram of another implementation mode of a steam turbine with wide load regulation of a supplementary steam valve according to the first embodiment of the present invention.
[0023] Figure 3 It is a schematic diagram of a method for regulating a steam turbine with wide load regulation of a supplementary steam valve according to a second embodiment of the present invention.
[0024] The reference numerals are described as follows:
[0025] 1 Medium pressure cylinder
[0026] 2 Low pressure cylinder
[0027] 3 Main steam valve
[0028] 4. First regulating valve
[0029] 5 Second regulating valve
[0030] 6 Steam supply valve
[0031] 7 Low pressure steam inlet valve DETAILED DESCRIPTION
[0032] The specific embodiments of the present invention are further described in detail below in conjunction with the accompanying drawings. These embodiments are only used to illustrate the present invention, but not to limit the present invention.
[0033] In the description of the present invention, it should be noted that the terms "center", "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operate in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first" and "second" are used for descriptive purposes only and cannot be understood as indicating or implying relative importance.
[0034] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.
[0035] Furthermore, in the description of the present invention, unless otherwise specified, “plurality” means two or more.
[0036] Embodiment 1
[0037] like Figure 1 and Figure 2 As shown, an embodiment of the steam turbine with a supplementary steam valve wide load regulation according to the present invention.
[0038] The steam turbine with wide load regulation of the supplementary steam valve of the first embodiment includes an intermediate pressure cylinder 1, a low pressure cylinder 2, a main steam valve 3, a first regulating valve 4, a second regulating valve 5 and a supplementary steam valve 6. Preferably, the caliber of the first regulating valve 4 is smaller than the caliber of the second regulating valve 5. The steam source passes through the main steam valve 3 and enters the flow portion of the intermediate pressure cylinder 1 through the first regulating valve 4 and / or the second regulating valve 5 to perform work. After the steam expands and performs work in the flow portion of the intermediate pressure cylinder 1, it enters the low pressure cylinder 2 through the low pressure steam inlet valve 7, that is, the exhaust steam of the intermediate pressure cylinder 1 enters the flow portion of the low pressure cylinder 2 through the low pressure steam inlet valve 7 to perform work. The steam source can also enter the flow portion of the low pressure cylinder 2 through the supplementary steam valve 6 to perform work. In the steam turbine with wide load regulation of the supplementary steam valve of the first embodiment, the supplementary steam valve 6 participates in load regulation starting from an extremely low unit load, which can expand the range of efficient operation of the steam turbine unit. By adjusting the opening size of the first regulating valve 4, the second regulating valve 5 and the supplementary steam valve 6, the full load and efficient operation of the steam turbine unit is achieved, thereby better adapting to the performance requirements of variable power in a wide load range.
[0039] See also Figure 1 In one embodiment, the supplementary steam valve 6 and the main steam valve 3 may be arranged in parallel. In this case, the steam source entering the supplementary steam valve 6 does not come from the main steam valve 3 .
[0040] join Figure 2 In another embodiment, the supplementary steam valve 6 and the main steam valve 3 may also be arranged in series. In this case, the steam source entering the supplementary steam valve 6 comes from the main steam valve 3, that is, the steam source passes through the main steam valve 3 and then enters the flow part of the low-pressure cylinder 2 through the supplementary steam valve 6 to perform work.
[0041] In the first embodiment, preferably, the flow section of the medium-pressure cylinder 1 and the flow section of the low-pressure cylinder 2 are arranged in a counter-flow form. Specifically, the flow section of the medium-pressure cylinder 1 is arranged in a reverse direction, and the steam entering the flow section of the medium-pressure cylinder 1 flows from back to front to do work, and the steam that has done work in the flow section of the medium-pressure cylinder 1 flows back from front to back from the interlayer steam flow channel between the outer cylinder of the medium-pressure cylinder 1 and the inner cylinder of the medium-pressure cylinder 1 into the flow section of the low-pressure cylinder 2; the flow section of the low-pressure cylinder 2 is arranged in a forward direction, and the steam that enters the flow section of the low-pressure cylinder 2 flows from front to back to do work; the steam that has done work in the flow section of the low-pressure cylinder 2 is discharged from the exhaust cylinder.
[0042] In the first embodiment, preferably, the main steam valve 3, the first regulating valve 4, the second regulating valve 5 and the supplementary steam valve 6 are all arranged at the top of the intermediate pressure cylinder 1, and steam is introduced from the direction of the sky. The first regulating valve 4 and the second regulating valve 5 are arranged on both sides of the intermediate pressure cylinder 1, and the steam is introduced in a full-circle manner. The supplementary steam valve 6 is arranged between the first regulating valve 4 and the second regulating valve 5. The first regulating valve 4 and the second regulating valve 5 both lead to the flow portion of the intermediate pressure cylinder 1. After the steam source passes through the main steam valve 3, it passes through at least one of the first regulating valve 4 and the second regulating valve 5 to enter the flow portion of the intermediate pressure cylinder 1 to perform work. The supplementary steam valve 6 leads to the interlayer steam flow channel between the outer cylinder of the intermediate pressure cylinder 1 and the inner cylinder of the intermediate pressure cylinder 1. The steam introduced by the supplementary steam valve 6 enters the interlayer steam flow channel between the outer cylinder of the intermediate pressure cylinder 1 and the inner cylinder of the intermediate pressure cylinder 1 through the supplementary steam valve 6, and then enters the flow portion of the low pressure cylinder 2 to perform work.
[0043] In order to meet the space limitation requirements of the steam turbine, preferably, the main steam valve 3, the first regulating valve 4, the second regulating valve 5 and the supplementary steam valve 6 all adopt individually controllable oil motors.
[0044] The arrangement of the steam turbine with wide load regulation of the supplementary steam valve in the first embodiment can make the temperature field of the cylinder more uniform and the deformation more coordinated. In addition, the coordinated use of the small regulating valve (the first regulating valve 4 and the second regulating valve 5) and the supplementary steam valve 6 makes the control of the steam turbine unit more precise and the anti-water erosion performance of the unit better.
[0045] The steam turbine with wide load regulation of the supplementary steam valve of the first embodiment, combined with a reasonable regulation scheme and efficient full-cycle steam inlet multi-stage small enthalpy drop reaction flow technology, can realize efficient operation of the steam turbine unit at full load (the unit can operate continuously and stably for a long time at a rated power level of 15%, and has an overload capacity of 110% rated power for continuous operation for 30 minutes), that is, it can achieve long-term ultra-low load operation and have a large overload capacity.
[0046] Embodiment 2
[0047] like Figure 3 As shown, based on the steam turbine with supplementary steam valve width load regulation of the above-mentioned embodiment 1, embodiment 2 of the present invention provides a regulation method for the steam turbine with supplementary steam valve width load regulation as described in embodiment 1.
[0048] The regulation method of the steam turbine with steam supplementary valve wide load regulation in the second embodiment is:
[0049] When the steam turbine unit starts to operate, the main steam valve 3, the first regulating valve 4 and the low-pressure steam inlet valve 7 are opened, and the second regulating valve 5 and the supplementary steam valve 6 are closed. At this time, high-temperature and high-pressure steam enters from the main steam valve 3, enters the inner cylinder of the intermediate pressure cylinder 1 through the first regulating valve 4 in a full-circle steam inlet manner, and flows through the flow-through part of the intermediate pressure cylinder 1 to expand and do work. As the unit load increases, the opening of the first regulating valve 4 gradually increases. The unit load gradually increases in the order of the first load a, the second load b, the third load c and the fourth load d, the rated load e, and the maximum load f.
[0050] When the unit load reaches the first load a, the supplementary steam valve 6 is opened, and the opening of the supplementary steam valve 6 gradually increases with the increase of the unit load. That is, at the first load a point, the supplementary steam valve 6 begins to be put into use. Preferably, the first load a is 9%-11% of the rated load, and optimally, the first load a is 10% of the rated load.
[0051] When the unit load reaches the second load b, the supplementary steam valve 6 maintains the current opening. That is, at the second load b, the supplementary steam valve 6 maintains the valve position. Preferably, the second load b is 12%-15% of the rated load, and optimally, the second load b is 15% of the rated load.
[0052] When the unit load reaches the third load c, the second regulating valve 5 is opened, and the opening of the second regulating valve 5 gradually increases with the increase of the unit load, and the opening of the supplementary steam valve 6 gradually decreases with the increase of the unit load. That is, at the third load c, the second regulating valve 5 is ready to open and start to be put into use, and the supplementary steam valve 6 is ready to close and start to exit. Preferably, the third load c is 59%-61% of the rated load, and optimally, the third load c is 60% of the rated load.
[0053] When the unit load reaches the fourth load d, the supplementary steam valve 6 is closed. That is, at the fourth load d, the supplementary steam valve 6 exits. Preferably, the fourth load d is 63%-65% of the rated load, and optimally, the fourth load d is 64% of the rated load.
[0054] When the unit load reaches the rated load e, the first regulating valve 4 and the second regulating valve 5 are fully opened, the supplementary steam valve 6 is opened, and the opening of the supplementary steam valve 6 gradually increases with the increase of the unit load. That is, at the rated load point e, the opening of the first regulating valve 4 and the second regulating valve 5 is increased to the maximum, the regulating valve is fully opened, and the supplementary steam valve 6 is ready to be opened and put into use again.
[0055] When the unit load reaches the maximum load f, the supplementary steam valve 6 is fully opened. That is, at the maximum load f point, the opening of the supplementary steam valve 6 increases to the maximum. At this time, the first regulating valve 4, the second regulating valve 5 and the supplementary steam valve 6 are all fully opened, reaching the maximum load f of the unit. The maximum load f is greater than the rated load. Preferably, the maximum load f is 110%-130% of the rated load.
[0056] In the regulation method of the steam turbine with wide load regulation of the supplementary steam valve of the second embodiment, when the supplementary steam valve 6 is in the closed state, high-temperature and high-pressure steam enters from the main steam valve 3, enters the inner cylinder of the intermediate pressure cylinder 1 through the first regulating valve 4 and the second regulating valve 5 (when the second regulating valve 5 is opened) in a full-circle steam intake mode, and flows through the flow portion of the intermediate pressure cylinder 1 to expand and perform work. The steam that has performed work in the flow portion of the intermediate pressure cylinder 1 flows back from the front to the back through the interlayer steam flow channel between the outer cylinder of the intermediate pressure cylinder 1 and the inner cylinder of the intermediate pressure cylinder 1 to enter the flow portion of the low pressure cylinder 2 to perform work; when the supplementary steam valve 6 is opened, the high-temperature and high-pressure steam also enters the interlayer steam flow channel between the outer cylinder of the intermediate pressure cylinder 1 and the inner cylinder of the intermediate pressure cylinder 1 through the supplementary steam valve 6, and then enters the flow portion of the low pressure cylinder 2 to perform work.
[0057] In the regulation method of the steam turbine with wide load regulation of the supplementary steam valve of the second embodiment, the supplementary steam valve 6 participates in the load regulation starting from the extremely low unit load, which can expand the range of efficient operation of the steam turbine unit. By adjusting the opening size of the first regulating valve 4, the second regulating valve 5 and the supplementary steam valve 6, the full load efficient operation of the steam turbine unit is realized (the unit can operate continuously and stably for a long time at a rated power level of 15%, and has an overload capacity of 110% rated power for continuous operation for 30 minutes), that is, long-term ultra-low load operation is realized and a large overload capacity is provided, so as to better adapt to the performance requirements of variable power in a wide load range.
[0058] Embodiment 3
[0059] Based on the steam turbine with supplementary steam valve width load regulation of the above-mentioned embodiment 1, embodiment 3 of the present invention provides a regulation method for the steam turbine with supplementary steam valve width load regulation as described in embodiment 1.
[0060] The regulation method of the steam turbine with wide load regulation of the supplementary steam valve in the third embodiment is a regulation method for single-sided operation of the steam turbine under extremely low unit load, specifically single-sided operation of the low-pressure cylinder 2 .
[0061] The regulation method of the steam turbine with wide load regulation of the supplementary steam valve of the third embodiment is as follows: when the steam turbine unit starts to operate, the main steam valve 3, the first regulating valve 4 and the low-pressure steam inlet valve 7 are opened, and the high-temperature and high-pressure steam passes through the main steam valve 3 and then enters the flow part of the intermediate pressure cylinder 1 through the first regulating valve 4, providing the minimum cooling flow for the intermediate pressure cylinder 1, and the opening of the first regulating valve 4 is kept at a small opening that only provides the minimum cooling flow for the intermediate pressure cylinder 1; the supplementary steam valve 6 is opened, and the high-temperature and high-pressure steam passes through the supplementary steam valve 6 and enters the flow part of the low-pressure cylinder 2 to do work, and the steam source entering the supplementary steam valve 6 can be from the main steam valve 3, or it can be not from the main steam valve 3, and the opening of the supplementary steam valve 6 gradually increases with the increase of the unit load. At this time, the intermediate pressure cylinder 1 is in the cylinder cutting state, the intermediate pressure cylinder 1 does not work, only the low pressure cylinder 2 works, and the steam turbine is in the extremely low load low pressure cylinder 2 single-side operation, and the supplementary steam valve 6 participates in the load regulation, which can realize the long-term continuous and stable operation of the unit under extremely low load.
[0062] Embodiment 4
[0063] Based on the steam turbine with supplementary steam valve wide load regulation of the above-mentioned embodiment 1, embodiment 4 of the present invention provides a regulation method for the steam turbine with supplementary steam valve wide load regulation as described in embodiment 1.
[0064] The regulation method of the steam turbine with wide load regulation of the supplementary steam valve in the fourth embodiment is a regulation method for single-sided operation of the steam turbine under extremely low unit load, specifically single-sided operation of the intermediate pressure cylinder 1.
[0065] The regulation method of the steam turbine with wide load regulation of the supplementary steam valve of the fourth embodiment is as follows: when the steam turbine unit starts to operate, the main steam valve 3 and the first regulating valve 4 are opened, and the low-pressure steam inlet valve 7 is closed. The high-temperature and high-pressure steam passes through the main steam valve 3 and then enters the flow part of the intermediate-pressure cylinder 1 through the first regulating valve 4 to perform work. Moreover, the exhaust steam of the intermediate-pressure cylinder 1 is supplied to external users instead of entering the flow part of the low-pressure cylinder 2. The opening of the first regulating valve 4 gradually increases with the increase of the unit load. The supplementary steam valve 6 is opened, and the high-temperature and high-pressure steam passes through the supplementary steam valve 6 and enters the flow part of the low-pressure cylinder 2 to provide the minimum cooling flow for the low-pressure cylinder 2. The opening of the supplementary steam valve 6 is maintained at a relatively small opening that only provides the minimum cooling flow for the low-pressure cylinder 2. The steam source entering the supplementary steam valve 6 may be from the main steam valve 3 or may not be from the main steam valve 3. At this time, the low-pressure cylinder 2 is in the cut-off state, the low-pressure cylinder 2 is not producing power, only the intermediate-pressure cylinder 1 is producing power, and the turbine is operating on one side of the intermediate-pressure cylinder 1 at an extremely low load. The supplementary steam valve 6 participates in providing the minimum cooling flow for the low-pressure cylinder 2, so that the unit can realize long-term continuous and stable operation at an extremely low load.
[0066] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and substitutions can be made without departing from the technical principles of the present invention. These improvements and substitutions should also be regarded as the scope of protection of the present invention.
Claims
1. A steam turbine with wide load regulation of a supplementary steam valve, characterized in that: The invention comprises an intermediate pressure cylinder (1), a low pressure cylinder (2), a main steam valve (3), a first regulating valve (4), a second regulating valve (5) and a supplementary steam valve (6); a steam source passes through the main steam valve (3) and then enters the flow section of the intermediate pressure cylinder (1) through the first regulating valve (4) and / or the second regulating valve (5) to perform work; exhaust steam of the intermediate pressure cylinder (1) enters the flow section of the low pressure cylinder (2) through a low pressure steam inlet valve (7) to perform work; and a steam source passes through the supplementary steam valve (6) and enters the flow section of the low pressure cylinder (2) to perform work.
2. The steam turbine with steam supplementary valve wide load regulation according to claim 1, characterized in that: The steam source passes through the main steam valve (3) and then through the supplementary steam valve (6) into the flow-through part of the low-pressure cylinder (2) to perform work.
3. The steam turbine with steam supplementary valve wide load regulation according to claim 1 or 2, characterized in that: The flow-through portion of the medium-pressure cylinder (1) and the flow-through portion of the low-pressure cylinder (2) are arranged in a counter-flow manner.
4. The steam turbine with steam supplementary valve wide load regulation according to claim 3, characterized in that: The main steam valve (3), the first regulating valve (4), the second regulating valve (5) and the supplementary steam valve (6) are all arranged at the top of the intermediate pressure cylinder (1); the first regulating valve (4) and the second regulating valve (5) are arranged on both sides of the intermediate pressure cylinder (1); and the supplementary steam valve (6) is arranged between the first regulating valve (4) and the second regulating valve (5).
5. The steam turbine with steam supplementary valve wide load regulation according to claim 4, characterized in that: The main steam valve (3), the first regulating valve (4), the second regulating valve (5) and the supplementary steam valve (6) all adopt individually controllable oil motors.
6. A method for regulating a steam turbine with a steam supplementary valve width load regulation according to any one of claims 1 to 5, characterized in that: When the steam turbine unit starts to operate, the main steam valve (3), the first regulating valve (4) and the low-pressure steam inlet valve (7) are opened, and the second regulating valve (5) and the supplementary steam valve (6) are closed; As the load of the unit increases, the opening of the first regulating valve (4) gradually increases; When the unit load reaches a first load, the supplementary steam valve (6) is opened, and the opening degree of the supplementary steam valve (6) gradually increases with the increase of the unit load; When the unit load reaches the second load, the supplementary steam valve (6) maintains the current opening; When the unit load reaches a third load, the second regulating valve (5) is opened, and the opening degree of the second regulating valve (5) gradually increases with the increase of the unit load, and the opening degree of the supplementary steam valve (6) gradually decreases with the increase of the unit load; When the unit load reaches a fourth load, the supplementary steam valve (6) is closed; When the unit load reaches the rated load, the first regulating valve (4) and the second regulating valve (5) are both fully opened, the supplementary steam valve (6) is opened, and the opening degree of the supplementary steam valve (6) gradually increases with the increase of the unit load; When the unit load reaches the maximum load, the steam supplement valve (6) is fully opened; The first load, the second load, the third load and the fourth load increase in sequence and are all less than the rated load, and the maximum load is greater than the rated load.
7. The method for regulating a steam turbine with a steam supplementary valve width load regulation according to claim 6, characterized in that: The first load is 9%-11% of the rated load, the second load is 12%-15% of the rated load, the third load is 59%-61% of the rated load, and the fourth load is 63%-65% of the rated load.
8. The method for regulating a steam turbine with a steam supplementary valve width load regulation according to claim 6, characterized in that: The maximum load is 110% to 130% of the rated load.
9. A method for regulating a steam turbine with a steam supplementary valve wide load regulation according to any one of claims 1 to 5, characterized in that: When the steam turbine unit starts to operate, the main steam valve (3), the first regulating valve (4) and the low-pressure steam inlet valve (7) are opened, and the steam passes through the main steam valve (3) and then through the first regulating valve (4) into the flow portion of the intermediate pressure cylinder (1), providing the minimum cooling flow for the intermediate pressure cylinder (1); the supplementary steam valve (6) is opened, and the steam passes through the supplementary steam valve (6) into the flow portion of the low-pressure cylinder (2) to perform work, and the opening degree of the supplementary steam valve (6) gradually increases with the increase of the unit load.
10. A method for regulating a steam turbine with a steam supplementary valve wide load regulation according to any one of claims 1 to 5, characterized in that: When the steam turbine unit starts to operate, the main steam valve (3) and the first regulating valve (4) are opened, the low-pressure steam inlet valve (7) is closed, and the steam passes through the main steam valve (3) and then through the first regulating valve (4) into the flow section of the intermediate pressure cylinder (1) to perform work, and the exhaust steam of the intermediate pressure cylinder (1) is supplied to external users. The opening of the first regulating valve (4) gradually increases with the increase of the unit load; the supplementary steam valve (6) is opened, and the steam passes through the supplementary steam valve (6) into the flow section of the low-pressure cylinder (2) to provide the minimum cooling flow for the low-pressure cylinder (2).