Wide-load constant-pressure machine furnace system

Abstract

The utility model discloses a wide-load constant-pressure machine furnace system, and belongs to the field of novel coal electricity of a thermal power plant. The system comprises a boiler economizer, a boiler water cooling wall, a boiler superheater, a first high-pressure cylinder, a second high-pressure cylinder, a first high-pressure heater, a second high-pressure heater, a boiler reheater, an intermediate-pressure cylinder, a first low-pressure cylinder, a second low-pressure cylinder, a first main steam valve, a second main steam valve, a first cold section adjusting valve and a second cold section adjusting valve. According to the utility model, the flexible adjustment of the steam flow and the maintenance of the high pressure level are realized, the energy efficiency and flexibility of the system are obviously improved, the adaptability of the boiler to variable load is greatly enhanced, the temperature stability of a working medium is improved, and the service life of the boiler is prolonged.

Description

Technical Field

[0001] This utility model belongs to the field of new coal-fired power technology in thermal power plants, and specifically relates to a wide-load constant pressure boiler system. Background Technology

[0002] The new power system requires coal-fired power plants to possess flexible and efficient characteristics to cope with the volatility and uncertainty of new energy power generation. Flexibility includes multiple aspects such as deep adjustment, peak load, and high load change rate, with high load change rate referring to the ability of coal-fired power plants to rapidly adjust their output power in a short period. Currently, the boiler parameter design of conventional thermal power plants is entirely based on turbine parameters to ensure coordination and matching between the two. However, due to the significant difference in turbine inlet steam pressure between high and low loads, this leads to substantial changes in furnace temperature distribution. In particular, the main pressure drop of the turbine occurs in the high-pressure cylinder, a characteristic that further exacerbates the impact of load changes on the operating status of the turbine and boiler.

[0003] While existing power systems can achieve flexible operation to a certain extent, they still face a series of challenges under high load rate requirements. First, high load rates cause turbines and boilers to experience higher temperature and mechanical stresses, accelerating equipment wear and aging and adversely affecting equipment lifespan. Second, due to the close correlation between boiler and turbine parameters, the significant difference in turbine inlet pressure between high and low loads makes it difficult to maintain a stable temperature distribution, further increasing the difficulty of operation control. Therefore, it is necessary to design a boiler-turbine system that can solve the problems faced by current technologies. Utility Model Content

[0004] The purpose of this invention is to provide a wide-load constant-pressure turbine boiler system. The turbine in this system is a multi-high-pressure turbine system, which solves the problem that the temperature distribution is difficult to maintain due to the significant difference in the steam inlet pressure at high and low loads. This invention, by setting up a multi-high-pressure turbine system and a cold section regulating valve, synchronously reconstructs a heater regeneration scheme adapted to the multi-high-pressure turbine system, and through certain operational adjustment methods, keeps the steam at the turbine inlet at a high-pressure and stable level as much as possible.

[0005] To achieve the above objectives, this utility model provides the following technical solution:

[0006] This utility model provides a wide-load constant pressure boiler system, including a boiler superheater, a first high-pressure cylinder, a second high-pressure cylinder, a first high-pressure heater, a second high-pressure heater, a boiler reheater, an intermediate-pressure cylinder, a first low-pressure cylinder, a second low-pressure cylinder, a boiler economizer, and a boiler water-cooled wall.

[0007] The boiler superheater is connected to both the No. 1 and No. 2 main steam valves via the boiler superheater to main steam valve pipeline. The No. 1 main steam valve is connected to the No. 1 high-pressure cylinder via the No. 1 main steam valve to No. 1 high-pressure cylinder pipeline. The No. 2 main steam valve is connected to the No. 2 high-pressure cylinder via the No. 2 main steam valve to No. 2 high-pressure cylinder pipeline. The No. 1 high-pressure cylinder is connected to the boiler reheater via the No. 1 high-pressure cylinder to boiler reheater pipeline. A No. 1 cold section regulating valve is installed on the No. 1 high-pressure cylinder to boiler reheater pipeline near the No. 1 high-pressure cylinder. The No. 2 high-pressure cylinder is connected to the boiler reheater via the No. 2 high-pressure cylinder to boiler reheater pipeline. A No. 2 cold section regulating valve is installed on the No. 2 high-pressure cylinder to boiler reheater pipeline near the No. 2 high-pressure cylinder.

[0008] High-pressure cylinder No. 1 and high-pressure cylinder No. 2 are connected to high-pressure heater No. 2 via pipelines from high-pressure cylinder No. 1 and high-pressure cylinder No. 2; high-pressure cylinder No. 1 is connected to high-pressure heater No. 1 via pipeline from high-pressure cylinder No. 1 to high-pressure heater No. 1, and high-pressure cylinder No. 2 is connected to high-pressure heater No. 1 via pipeline from high-pressure cylinder No. 2 to high-pressure heater No. 1; boiler reheater is connected to intermediate-pressure cylinder via pipeline from boiler reheater to intermediate-pressure cylinder; intermediate-pressure cylinder is connected to low-pressure cylinder No. 1 and low-pressure cylinder No. 2 via pipelines from intermediate-pressure cylinder to low-pressure cylinder No. 1 and low-pressure cylinder No. 2.

[0009] High-pressure heater No. 2 is connected to high-pressure heater No. 1 through a high-pressure water supply pipeline. High-pressure heater No. 1 is connected to the boiler economizer through a high-pressure water supply pipeline. The boiler economizer is connected to the boiler water-cooled wall. The boiler water-cooled wall is connected to the boiler superheater.

[0010] The pipeline from the boiler superheater to the main steam valve consists of two pipelines. One end of the first pipeline is connected to one end of the boiler superheater, and the other end of the first pipeline is connected to both the No. 1 and No. 2 main steam valves. One end of the second pipeline is connected to the other end of the boiler superheater, and the other end of the second pipeline is connected to both the No. 1 and No. 2 main steam valves.

[0011] The pipeline from the boiler reheater to the intermediate pressure cylinder consists of two pipelines. One end of the first pipeline is connected to one end of the boiler reheater, and the other end of the first pipeline is connected to the air inlet of the intermediate pressure cylinder. One end of the second pipeline is connected to the other end of the boiler reheater, and the other end of the second pipeline is connected to the air inlet of the intermediate pressure cylinder.

[0012] Reheat steam valves are installed on both pipelines from the boiler reheater to the intermediate pressure cylinder.

[0013] The pipeline from high-pressure cylinder No. 1 to high-pressure heater No. 1 is connected in the middle of high-pressure cylinder No. 1, and the pipeline from high-pressure cylinder No. 2 to high-pressure heater No. 1 is connected in the middle of high-pressure cylinder No. 2.

[0014] The pipes from the intermediate pressure cylinder to the first and second low-pressure cylinders are connected to both ends of the intermediate pressure cylinder.

[0015] The No. 1 high-pressure cylinder, the No. 2 high-pressure cylinder, the intermediate-pressure cylinder, the No. 1 low-pressure cylinder, and the No. 2 low-pressure cylinder are arranged coaxially.

[0016] The wide-load constant pressure furnace system has no less than two high-pressure cylinders; the high-pressure cylinders are connected to the high-pressure heaters via pipelines; the high-pressure cylinders are connected to the heat exchangers via pipelines.

[0017] Compared with the prior art, the beneficial effects of this utility model are as follows:

[0018] The wide-load constant-pressure boiler system provided by this utility model, by setting up multiple high-pressure cylinders, allows for more flexible adjustment of steam flow and pressure to adapt to different load demands. This configuration helps maintain a high-pressure steam level during load changes, thereby improving the overall system efficiency. The main steam valve and cold-section regulating valve installed on the main steam pipeline enable precise control of steam flow. This synergistic effect allows the system to maintain the flow rate of the high-pressure cylinders by adjusting valve openings at different load stages, thus optimizing energy efficiency. The wide-load constant-pressure boiler system maintains a high-pressure steam level, indirectly increasing the feedwater temperature and helping to improve the economizer inlet working fluid temperature level under variable load conditions, making boiler operation more stable. The wide-load constant-pressure boiler system can flexibly respond to load changes, maintaining stable boiler operation by adjusting the steam flow of a single high-pressure cylinder. This reduces the impact of load changes on boiler lifespan and extends its service life. The configuration of multiple high-pressure cylinders and the flexible steam flow adjustment scheme enable the system to maintain stable operation when facing load changes, thereby improving system reliability. By optimizing steam flow and pressure, this system can reduce stress fatigue caused by variable loads, providing a safe and reliable solution for power production. Attached Figure Description

[0019] To more clearly illustrate the technical solutions of the embodiments of this utility model, the drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of this utility model and should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0020] Figure 1 This is a schematic diagram of the wide-load constant pressure furnace system of this utility model;

[0021] Figure 2 This is a side view of the multi-high-pressure cylinder steam turbine in the wide-load constant-pressure boiler system of this utility model;

[0022] The components include: 1. Boiler superheater; 2. Main steam valve No. 1; 3. Main steam valve No. 2; 4. High-pressure cylinder No. 1; 5. High-pressure cylinder No. 2; 6. Cold section regulating valve No. 1; 7. Cold section regulating valve No. 2; 8. High-pressure heater No. 1; 9. High-pressure heater No. 2; 10. Boiler reheater; 11. Reheat steam valve; 12. Intermediate-pressure cylinder; 13. Low-pressure cylinder No. 1; 14. Low-pressure cylinder No. 2; 15. Generator; 16. Boiler economizer; 17. Boiler water-cooled wall.

[0023] L1, Boiler superheater to main steam valve pipeline; L2, No. 1 main steam valve to No. 1 high-pressure cylinder pipeline; L3, No. 2 main steam valve to No. 2 high-pressure cylinder pipeline; L4, No. 1 high-pressure cylinder to boiler reheater pipeline; L5, No. 2 high-pressure cylinder to boiler reheater pipeline; L6, No. 1 and No. 2 high-pressure cylinders to No. 2 high-pressure heater pipeline; L7, No. 1 high-pressure cylinder to No. 1 high-pressure heater pipeline; L8, No. 2 high-pressure cylinder to No. 1 high-pressure heater pipeline; L9, Boiler reheater to intermediate pressure cylinder pipeline; L10, intermediate pressure cylinder to No. 1 and No. 2 low-pressure cylinders pipeline; L11, No. 2 high-pressure heater to No. 1 high-pressure heater pipeline; L12, No. 1 high-pressure heater to boiler economizer pipeline. Detailed Implementation

[0024] To make the objectives, technical solutions, and advantages of the embodiments of this utility model clearer, the technical solutions of the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this utility model, not all embodiments. The components of the embodiments of this utility model described and shown in the accompanying drawings can typically be arranged and designed in various different configurations.

[0025] 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 claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

[0026] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0027] In the description of the embodiments of this utility model, it should be noted that the terms "upper," "lower," "left," "right," "front," "rear," "top," "bottom," "inner," "outer," "middle," "vertical," "horizontal," "lateral," and "longitudinal," indicating orientation or positional relationships, are based on the orientation or positional relationships shown in the accompanying drawings, or the orientation or positional relationships commonly used when the utility model product is in use. These are merely for the convenience of describing the utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the utility model. Furthermore, the terms "first," "second," etc., are only used to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0028] Furthermore, the use of the term "horizontal" does not imply that the component must be absolutely horizontal, but rather that it can be slightly tilted. For example, "horizontal" simply means that its direction is more horizontal than "vertical," and does not mean that the structure must be completely horizontal, but can be slightly tilted.

[0029] In the description of the embodiments of this utility model, it should also be noted that, unless otherwise explicitly specified and limited, the terms "set," "install," "connect," and "link" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.

[0030] The present invention will now be described in further detail with reference to the accompanying drawings:

[0031] like Figure 1 and Figure 2 As shown, the present invention provides a wide-load constant pressure boiler system, including a boiler economizer 16, a boiler water-cooled wall 17, a boiler superheater 1, a first high-pressure cylinder 4, a second high-pressure cylinder 5, a first high-pressure heater 8, a second high-pressure heater 9, a boiler reheater 10, a medium-pressure cylinder 12, a first low-pressure cylinder 13, and a second low-pressure cylinder 14.

[0032] Boiler superheater 1 is connected to both main steam valve 2 and main steam valve 3 via pipeline L1. Main steam valve 2 is connected to high-pressure cylinder 4 via pipeline L2. Main steam valve 3 is connected to high-pressure cylinder 5 via pipeline L3. High-pressure cylinder 4 is connected to boiler reheater 10 via pipeline L4. A cold section regulating valve 6 is installed on pipeline L4 from high-pressure cylinder 4 to boiler reheater 10. High-pressure cylinder 5 is connected to boiler reheater 10 via pipeline L4 from high-pressure cylinder 4. A second cold section regulating valve 7 is installed on the pipeline L5 from the first high-pressure cylinder to the boiler reheater; the first high-pressure cylinder 4 and the second high-pressure cylinder 5 are connected to the second high-pressure heater 9 through the pipeline L6 from the first high-pressure cylinder and the second high-pressure cylinder to the second high-pressure heater; the first high-pressure cylinder 4 is connected to the first high-pressure heater 8 through the pipeline L7 from the first high-pressure cylinder to the first high-pressure heater, and the second high-pressure cylinder 5 is connected to the first high-pressure heater 8 through the pipeline L8 from the second high-pressure cylinder to the first high-pressure heater; the boiler reheater 10 is connected to the intermediate-pressure cylinder 12 through the pipeline L9 from the boiler reheater to the intermediate-pressure cylinder; the intermediate-pressure cylinder 12 is connected to the first low-pressure cylinder 13 and the second low-pressure cylinder 14 through the pipeline L10 from the intermediate-pressure cylinder to the first low-pressure cylinder and the second low-pressure cylinder.

[0033] High-pressure heater 9 is connected to high-pressure heater 8 via high-pressure water supply pipe L11. High-pressure heater 8 is connected to boiler economizer 16 via high-pressure water supply pipe L12. Boiler economizer 16 is connected to boiler water-cooled wall 17. Boiler water-cooled wall 17 is connected to boiler superheater 1.

[0034] The pipeline L1 from the boiler superheater to the main steam valve consists of two pipelines. One end of the first pipeline is connected to one end of the boiler superheater 1, and the other end of the first pipeline is connected to both the No. 1 main steam valve 2 and the No. 2 main steam valve 3. One end of the second pipeline is connected to the other end of the boiler superheater 1, and the other end of the second pipeline is connected to both the No. 1 main steam valve 2 and the No. 2 main steam valve 3.

[0035] The boiler reheater to intermediate pressure cylinder pipeline L9 consists of two pipelines. One end of the first pipeline is connected to one end of the boiler reheater 10, and the other end of the first pipeline is connected to the air inlet of the intermediate pressure cylinder 12. One end of the second pipeline is connected to the other end of the boiler reheater 10, and the other end of the second pipeline is connected to the air inlet of the intermediate pressure cylinder 12.

[0036] Reheat steam valves 11 are installed on both pipelines from the boiler reheater to the intermediate pressure cylinder pipeline L9.

[0037] The pipeline L10 from the intermediate pressure cylinder to the first and second low-pressure cylinders is connected to both ends of the intermediate pressure cylinder 12.

[0038] The pipeline L7 from the No. 1 high-pressure cylinder to the No. 1 high-pressure heater is connected in the middle of the No. 1 high-pressure cylinder 4, and the pipeline L8 from the No. 2 high-pressure cylinder to the No. 1 high-pressure heater is connected in the middle of the No. 2 high-pressure cylinder 5.

[0039] High-pressure cylinder 4 (No. 1), high-pressure cylinder 5 (No. 2), medium-pressure cylinder 12, low-pressure cylinder 13 (No. 1), and low-pressure cylinder 14 (No. 2) are coaxially arranged.

[0040] In a wide-load constant pressure furnace system, there are no fewer than two high-pressure cylinders; the high-pressure cylinders are connected to the high-pressure heaters via pipes; the high-pressure cylinders can also be connected to the heat exchangers via pipes.

[0041] The working method of a wide-load constant pressure furnace system provided by this utility model includes:

[0042] During the 90%-100% load phase, main steam valve 2 (No. 1) and main steam valve 3 (No. 2) are adjusted synchronously to maintain the same air intake for high-pressure cylinders 4 (No. 1) and 5 (No. 2), while cold section regulating valves 6 (No. 1) and 7 (No. 2) are fully open. During the 50%-90% load phase, main steam valves 2 (No. 1) and 3 (No. 2) remain unchanged, while cold section regulating valve 6 (No. 1) or 7 (No. 2) is adjusted to reduce the flow rate through one of the high-pressure cylinders. During the 40%-50% load phase, high-pressure cylinder 4 (No. 1) or high-pressure cylinder 5 (No. 2) is adjusted only... To maintain minimum cooling flow, reduce the main steam valve and cold section regulating valve connected to the high-pressure cylinder; on the other side, the high-pressure cylinder operates at high load, with the cold section regulating valve of the high-load high-pressure cylinder fully open, and the flow rate regulated by the main steam valve; in the stage below 40% load, either high-pressure cylinder 4 (number one) or high-pressure cylinder 5 (number two) maintains only minimum cooling flow, and the main steam valve and cold section regulating valve connected to the high-pressure cylinder are reduced; on the other side, the cold section regulating valve of the high-load high-pressure cylinder is closed, and the flow rate is regulated by the main steam valve, with the cold section regulating valve and the main steam valve working together to maintain the pressure at the inlet of the main steam valve.

[0043] This invention uses certain operational adjustment methods to maintain the steam at the turbine inlet at a high pressure level as much as possible, thereby indirectly increasing the feedwater temperature and improving the working fluid temperature level of the boiler under variable load conditions; it also improves the boiler's adaptability to variable loads and reduces the impact of variable loads on the boiler's lifespan.

[0044] The above embodiments are only used to illustrate the technical solution of this utility model and are not intended to limit it. Although the utility model has been described in detail with reference to the above embodiments, those skilled in the art can still make modifications or equivalent substitutions to the specific implementation of this utility model. Any modifications or equivalent substitutions that do not depart from the spirit and scope of this utility model are within the protection scope of the claims of this utility model pending approval.

Claims

1. A wide-load constant-pressure furnace system, characterized in that, It includes a boiler superheater (1), a No. 1 high-pressure cylinder (4), a No. 2 high-pressure cylinder (5), a No. 1 high-pressure heater (8), a No. 2 high-pressure heater (9), a boiler reheater (10), a medium-pressure cylinder (12), a No. 1 low-pressure cylinder (13), a No. 2 low-pressure cylinder (14), a boiler economizer (16), and a boiler water-cooled wall (17). The boiler superheater (1) is connected to both the No. 1 main steam valve (2) and the No. 2 main steam valve (3) through the boiler superheater to main steam valve pipeline (L1). The No. 1 main steam valve (2) is connected to the No. 1 high-pressure cylinder (4) through the No. 1 main steam valve to No. 1 high-pressure cylinder pipeline (L2). The No. 2 main steam valve (3) is connected to the No. 2 high-pressure cylinder (5) through the No. 2 main steam valve to No. 2 high-pressure cylinder pipeline (L3). The No. 1 high-pressure cylinder (4) is connected to the boiler reheater (10) through the No. 1 high-pressure cylinder to boiler reheater pipeline (L4). A No. 1 cold section regulating valve (6) is installed on the No. 1 high-pressure cylinder to boiler reheater pipeline (L4) near the No. 1 high-pressure cylinder (4). The No. 2 high-pressure cylinder (5) is connected to the boiler reheater (10) through the No. 2 high-pressure cylinder to boiler reheater pipeline (L5). A No. 2 cold section regulating valve (7) is installed on the No. 2 high-pressure cylinder to boiler reheater pipeline (L5) near the No. 2 high-pressure cylinder (5). High-pressure cylinder 1 (4) and high-pressure cylinder 2 (5) are connected to high-pressure heater 2 (9) via high-pressure cylinder 1 and high-pressure cylinder 2 to high-pressure heater 2 pipeline (L6); high-pressure cylinder 1 (4) is connected to high-pressure heater 1 (8) via high-pressure cylinder 1 to high-pressure heater 1 pipeline (L7); high-pressure cylinder 2 (5) is connected to high-pressure heater 1 (8) via high-pressure cylinder 2 to high-pressure heater 1 pipeline (L8); boiler reheater (10) is connected to intermediate-pressure cylinder (12) via boiler reheater to intermediate-pressure cylinder pipeline (L9); intermediate-pressure cylinder (12) is connected to low-pressure cylinder 1 (13) and low-pressure cylinder 2 (14) via intermediate-pressure cylinder to low-pressure cylinder 1 and low-pressure cylinder 2 pipeline (L10); The No. 2 high-pressure heater (9) is connected to the No. 1 high-pressure heater (8) through the high-pressure water supply pipe (L11). The No. 1 high-pressure heater (8) is connected to the boiler economizer (16) through the high-pressure water supply pipe (L12). The boiler economizer (16) is connected to the boiler water-cooled wall (17). The boiler water-cooled wall (17) is connected to the boiler superheater (1).

2. The wide-load constant-pressure boiler system according to claim 1, characterized in that, The pipeline (L1) from the boiler superheater to the main steam valve consists of two pipelines. One end of the first pipeline is connected to one end of the boiler superheater (1), and the other end of the first pipeline is connected to both the No. 1 main steam valve (2) and the No. 2 main steam valve (3). One end of the second pipeline is connected to the other end of the boiler superheater (1), and the other end of the second pipeline is connected to both the No. 1 main steam valve (2) and the No. 2 main steam valve (3).

3. The wide-load constant-pressure furnace system according to claim 1, characterized in that, The boiler reheater to intermediate pressure cylinder pipeline (L9) consists of two pipelines. One end of the first pipeline is connected to one end of the boiler reheater (10), and the other end of the first pipeline is connected to the air inlet of the intermediate pressure cylinder (12). One end of the second pipeline is connected to the other end of the boiler reheater (10), and the other end of the second pipeline is connected to the air inlet of the intermediate pressure cylinder (12).

4. A wide-load constant-pressure furnace system according to claim 3, characterized in that, Reheat steam valves (11) are installed on both pipelines from the boiler reheater to the intermediate pressure cylinder pipeline (L9).

5. A wide-load constant-pressure furnace system according to claim 1, characterized in that, The pipeline (L7) from the No. 1 high-pressure cylinder to the No. 1 high-pressure heater is connected in the middle of the No. 1 high-pressure cylinder (4), and the pipeline (L8) from the No. 2 high-pressure cylinder to the No. 1 high-pressure heater is connected in the middle of the No. 2 high-pressure cylinder (5).

6. A wide-load constant-pressure furnace system according to claim 1, characterized in that, The pipeline (L10) from the intermediate pressure cylinder to the first and second low-pressure cylinders is connected to both ends of the intermediate pressure cylinder (12).

7. A wide-load constant-pressure boiler system according to claim 1, characterized in that, The No. 1 high-pressure cylinder (4), the No. 2 high-pressure cylinder (5), the medium-pressure cylinder (12), the No. 1 low-pressure cylinder (13), and the No. 2 low-pressure cylinder (14) are coaxially arranged.

8. A wide-load constant-pressure furnace system according to claim 1, characterized in that, The wide-load constant pressure furnace system has no less than two high-pressure cylinders; the high-pressure cylinders are connected to the high-pressure heaters via pipelines; the high-pressure cylinders are connected to the heat exchangers via pipelines.

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