A state reconstruction-based steam turbine thermal system, a design method and an operation method

Abstract

The application provides a steam turbine thermal system based on state reconstruction, a design method and an operation method. The thermal system comprises at least one first working cylinder and at least one second working cylinder. One first working cylinder and one corresponding second working cylinder form a reconstruction cylinder group. The reconstruction cylinder group is configured to control one working cylinder to be coupled into a thermal working shaft system and the other working cylinder to be decoupled from the thermal working shaft system based on a load condition factor. Through monitoring and controlling the load condition factor, the working cylinder more suitable for the current load condition is coupled into the thermal working shaft system to achieve better thermal effect, and the working cylinder unsuitable for the current load condition is decoupled from the thermal working shaft system to realize more flexible load management and optimize thermal efficiency.

Description

Technical Field

[0001] This invention belongs to the field of steam turbine power generation technology, and particularly relates to a steam turbine thermodynamic system based on state reconfiguration, its design method, and its operation method. Background Technology

[0002] Traditional steam turbine thermal systems are widely used in power generation and industrial production worldwide, with their main advantages being their ability to perform large-scale energy conversion and long-term stable operation. However, with changing energy market demands and the continuous integration of renewable energy, steam turbine systems face increasing challenges, particularly in terms of load regulation performance, safety performance, and energy efficiency.

[0003] In traditional systems, steam turbines are often designed to operate most efficiently under near-full-load conditions. When the system operates at low load, the unit's operating parameters deviate significantly from the design conditions, leading to a substantial decrease in the cycle efficiency of the thermal system and a significant drop in the internal efficiency of the steam turbine. This results in a significant decline in the safety and reliability of key components. Simultaneously, other critical equipment involved in the thermal system, such as boilers, also face a significant decrease in safety, reliability, and pollutant emission control performance.

[0004] Furthermore, traditional steam turbines face a series of problems when responding to load changes under low-load conditions. These include a significant decrease in safety and reliability, hindering deep regulation, and significant deviations from rated operating conditions in the thermal and steam distribution systems, making effective regulation difficult. These issues pose challenges to the stability and reliability of the power grid. Existing peak-shaving and frequency regulation technologies mostly rely on mechanical regulation and control system adjustments, which have inherent physical limitations and cannot efficiently respond to the urgent needs of rapid grid regulation. Summary of the Invention

[0005] In order to overcome the shortcomings of the prior art, the purpose of this invention is to provide a steam turbine thermodynamic system, design method and operation method based on state reconstruction, which is mainly used to solve the problems of low thermal efficiency, poor safety and reliability, slow response efficiency and large adjustment limitations that traditional thermodynamic systems in the prior art exhibit when facing low load or variable load conditions.

[0006] To solve the above problems, the technical solution adopted by the present invention is as follows:

[0007] In a first aspect, the present invention provides a state-reconfigurable turbine thermodynamic system, including at least one first working cylinder and at least one second working cylinder, wherein one first working cylinder and a corresponding second working cylinder form a reconfigurable cylinder group, the reconfigurable cylinder group being configured to control one of the working cylinders to couple into the thermodynamic working shaft system based on a load condition factor, while the other working cylinder is decoupled from the thermodynamic working shaft system.

[0008] In some embodiments, the number of reconfigurable cylinder groups is greater than 1, and the load condition factor control judgment benchmark values ​​corresponding to different reconfigurable cylinder groups are different.

[0009] In some embodiments, the number of reconfigurable cylinder groups is greater than 1, and the load condition factor control judgment benchmark values ​​corresponding to different reconfigurable cylinder groups are the same.

[0010] In some embodiments, the first power cylinder and the second power cylinder in the same reconfigurable cylinder group are arranged coaxially or off-axis.

[0011] In some embodiments, the first working cylinder and / or the second working cylinder in the same reconfigurable cylinder bank are connected to the end of their corresponding thermodynamic working shaft via a clutch.

[0012] In some embodiments, the first working cylinder and the second working cylinder in the same reconfigurable cylinder group have different pressure levels, and the flow characteristics of one working cylinder are equivalent to the flow characteristics of the corresponding pressure level in the front or rear region of the other working cylinder.

[0013] In some embodiments, the system further includes an intermediate-pressure cylinder, wherein the first working cylinder is a first low-pressure cylinder, the second working cylinder is a second low-pressure cylinder, the steam inlet of the first low-pressure cylinder is connected to the steam outlet of the intermediate-pressure cylinder through a first valve, and the steam inlet of the second low-pressure cylinder is connected to the steam outlet of the intermediate-pressure cylinder through a second valve, wherein the first valve and the second valve can be selectively switched on and off.

[0014] In some embodiments, the second low-pressure cylinder has fewer pressure stages than the first low-pressure cylinder, and the flow characteristics of the second low-pressure cylinder are comparable to the flow characteristics of the corresponding pressure stage in the front region of the first low-pressure cylinder.

[0015] In some embodiments, the first low-pressure cylinder and the second low-pressure cylinder are arranged coaxially or diaxially.

[0016] In some embodiments, the first low-pressure cylinder and / or the second low-pressure cylinder are connected to the end of their respective thermodynamic power-operating shaft system via a low-pressure stage clutch.

[0017] In some embodiments, the intermediate-pressure cylinder and the first low-pressure cylinder are coaxially arranged, the first low-pressure cylinder is connected to the end of the first thermodynamic power-operating shaft system through a low-pressure stage clutch, and the second low-pressure cylinder is arranged in the second thermodynamic power-operating shaft system.

[0018] In some embodiments, the intermediate-pressure cylinder and the second low-pressure cylinder are coaxially arranged, the second low-pressure cylinder is connected to the end of the first thermodynamic power-operating shaft system through a low-pressure stage clutch, and the first low-pressure cylinder is arranged in the second thermodynamic power-operating shaft system.

[0019] In some embodiments, a reheater is further included. The first working cylinder is a first high-pressure cylinder, and the second working cylinder is a second high-pressure cylinder. The steam inlet of the first high-pressure cylinder is connected to the main steam through a third valve, and the steam exhaust of the first high-pressure cylinder is connected to the reheater through a fourth valve. The steam inlet of the second high-pressure cylinder is connected to the main steam through a fifth valve, and the steam exhaust of the second high-pressure cylinder is connected to the reheater through a sixth valve. The third, fourth, fifth, and sixth valves can be selectively switched on and off.

[0020] In some embodiments, the second high-pressure cylinder has more pressure stages than the first high-pressure cylinder, and the flow characteristics of the first high-pressure cylinder are comparable to the flow characteristics of the corresponding pressure stage in the rear region of the second high-pressure cylinder.

[0021] In some embodiments, the first high-pressure cylinder and the second high-pressure cylinder are arranged coaxially or diaxially.

[0022] In some embodiments, the first high-pressure cylinder and / or the second high-pressure cylinder are connected to the end of their corresponding thermodynamic power-operating shaft system via a high-pressure stage clutch.

[0023] Secondly, the present invention provides a design method for a steam turbine thermal system applied in at least some of the above embodiments, wherein the design pressure of the condenser is set to P under 100% rated load conditions. n The rated inlet pressure of the first low-pressure cylinder is P. L1 The rated steam flow rate of the first low-pressure cylinder is m³ / s. L1 The load condition factor control judgment benchmark value for determining state reconfiguration is the load rate L. x1 ;

[0024] With load factor L x1 The operating condition is the rated load condition of the second low-pressure cylinder. The rated inlet steam mass flow rate (m) of the second low-pressure cylinder is verified and determined. L2 and rated inlet steam pressure P L2 ;

[0025] Based on the inlet steam mass flow rate m L2 Rated inlet steam pressure P L2 and condenser pressure P n The flow passage structure of the second low-pressure cylinder was verified.

[0026] Thirdly, the present invention provides a design method for a steam turbine thermal system applied in at least some of the above embodiments, wherein, under 100% rated load conditions, the rated main steam flow rate of the first high-pressure cylinder is m1, the rated main steam pressure of the first high-pressure cylinder is P1, and the rated exhaust pressure of the first high-pressure cylinder is P. b The load condition factor control judgment benchmark value for determining state reconfiguration is the load rate L. x2 ;

[0027] With load factor L x2 The operating condition is the rated load condition of the second high-pressure cylinder. The rated main steam flow rate (m2) of the second high-pressure cylinder is verified and determined, and the rated exhaust pressure (P) of the second high-pressure cylinder is also verified and determined. b2 ;

[0028] Based on the rated main steam flow rate m2, rated inlet steam pressure P1, and rated outlet steam pressure P... b2 The flow passage structure of the second high-pressure cylinder was checked and designed.

[0029] Fourthly, the present invention provides an operation method for a steam turbine thermal system applied in at least some of the above embodiments.

[0030] Select a set of reconfigurable cylinder groups, set the load condition factor control judgment benchmark value corresponding to the reconfigurable cylinder group to L0, and the load fluctuation range of the transition zone to ΔL0. Set the high load condition to (L0+ΔL0, A0%), the low load condition to [B0%, L0-ΔL0], the upper transition zone load condition to (L0, L0+ΔL0], and the lower transition zone load condition to (L0-ΔL0, L0].

[0031] Determine the current load condition range of the load condition factor;

[0032] If under high load conditions, the first working cylinder in the reconfigured cylinder group is coupled into the thermodynamic working shaft system, and the second working cylinder is decoupled from the thermodynamic working shaft system;

[0033] If under low load conditions, the second working cylinder in the reconfigured cylinder group is coupled into the thermodynamic working shaft system, and the first working cylinder is decoupled from the thermodynamic working shaft system.

[0034] Under the upper transition zone load condition, if the unit is in a variable load process, the unit structure remains unchanged; if it is in a steady state condition, the high load condition shall be followed.

[0035] Under the lower transition zone load condition, if the unit is in a variable load process, the unit structure remains unchanged; if it is in a steady state condition, the low load condition shall be followed.

[0036] Fifthly, the present invention provides an operation method for a steam turbine thermal system applied in at least some of the above embodiments.

[0037] For the low-pressure reconfiguration cylinder group, the corresponding load condition factor control judgment benchmark value is set to L1, and the load fluctuation range ΔL1 in the transition zone is set.

[0038] The high load condition is set as (L1+ΔL1, A1%), the low load condition as [B1%, L1-ΔL1], the upper transition zone load condition as (L1, L1+ΔL1], and the lower transition zone load condition as (L1-ΔL1, L1].

[0039] Determine the current load condition range of the load condition factor;

[0040] If under high load conditions, open the first valve and close the second valve to allow steam to pass through the intermediate pressure cylinder and the first low pressure cylinder in sequence;

[0041] If under low load conditions, open the second valve and close the first valve to allow steam to pass through the intermediate pressure cylinder and then enter the second low pressure cylinder;

[0042] Under the upper transition zone load condition, if the unit is in a variable load process, the unit structure remains unchanged; if it is in a steady state condition, the high load condition shall be followed.

[0043] Under the lower transition zone load condition, if the unit is in a variable load process, the unit structure remains unchanged; if it is in a steady state condition, the low load condition shall be followed.

[0044] Sixthly, the present invention provides an operation method for a steam turbine thermal system applied in at least some of the above embodiments.

[0045] For the high-pressure reconfiguration cylinder group, the corresponding load condition factor control judgment benchmark value is set to L2, and the load fluctuation range ΔL2 in the transition zone is set.

[0046] The high load condition is set as (L2+ΔL2, A2%), the low load condition as [B2%, L2-ΔL2], the upper transition zone load condition as (L2, L2+ΔL2], and the lower transition zone load condition as (L2-ΔL2, L2].

[0047] Determine the current load condition range of the load condition factor;

[0048] If under high load conditions, open the third and fourth valves and close the fifth and sixth valves to allow the main steam to directly enter the first high-pressure cylinder and then be discharged into the reheater;

[0049] If under low load conditions, open the fifth and sixth valves and close the third and fourth valves to allow the main steam to directly enter the second high-pressure cylinder and then be discharged into the reheater;

[0050] Under the upper transition zone load condition, if the unit is in a variable load process, the unit structure remains unchanged; if it is in a steady state condition, the high load condition shall be followed.

[0051] Under the lower transition zone load condition, if the unit is in a variable load process, the unit structure remains unchanged; if it is in a steady state condition, the low load condition shall be followed.

[0052] Compared with the prior art, the present invention has at least the following beneficial effects:

[0053] 1. By introducing the concept of state reconfiguration, the turbine thermal system can dynamically adjust its structure according to changes in load conditions, thereby comprehensively optimizing the operating parameters of the thermal system and significantly improving the safety, reliability, thermal efficiency, load response characteristics, and economic efficiency of the thermal system under different load conditions. Compared with traditional turbine thermal systems, this invention can ensure the safe and reliable operation of the unit within a wider load range, maintain high thermal efficiency, reduce energy loss, and lower fuel consumption, resulting in significant energy-saving effects.

[0054] 2. The design of the reconfigurable cylinder group allows for flexible control of the coupling and decoupling of the working cylinder, enabling rapid reconfiguration of the thermodynamic system state and greatly improving the system's adaptability and response speed to load changes. Compared with conventional turbine regulation methods, this invention can adjust the system structure to enable the unit to operate within a new optimal operating range under lower load conditions, thereby significantly improving the unit's overall regulation performance.

[0055] 3. Design methods for different types of reconfigurable cylinder groups are proposed, providing comprehensive design guidance for realizing state-reconfigurable steam turbine thermodynamic systems. By reasonably matching the structural and operating parameters of the reconfigurable cylinder groups, the operating conditions of the thermodynamic system can be reconfigured under different load conditions, maximizing the efficiency advantages of each working cylinder and improving the overall system performance. The design method provided by this invention is universal and targeted, and can be widely applied to the optimization design of various steam turbine thermodynamic systems.

[0056] 4. The invention provides a corresponding operating method that can adjust the working state of the reconfigurable cylinder group in real time according to changes in load conditions, ensuring that the system always operates under optimal conditions. Compared with traditional operation control strategies, this invention can accurately determine load characteristics, automatically select the best system configuration and operating parameters, avoid human error, and improve the intelligence and reliability of operation. At the same time, this invention can also be combined with existing monitoring and fault diagnosis systems to achieve real-time supervision and safety protection of the state reconfiguration process.

[0057] 5. This invention possesses excellent versatility and scalability, applicable not only to the design of new steam turbine units but also to the retrofitting and upgrading of existing steam turbine units. By reconfiguring the existing steam turbine thermal system, its operational flexibility and economy can be significantly improved, extending the unit's lifespan and reducing lifecycle costs. This invention provides new technical means and implementation paths for energy-saving retrofitting and green development in the power industry, and is applicable to both new units and existing units with sufficient site space.

[0058] The present invention will now be described in further detail with reference to the accompanying drawings and specific embodiments. Attached Figure Description

[0059] The present invention will be further described with reference to the accompanying drawings, but the embodiments in the drawings do not constitute any limitation on the present invention. For those skilled in the art, other drawings can be obtained based on the following drawings without creative effort.

[0060] Figure 1 This is a schematic diagram of the structure of a steam turbine thermodynamic system based on state reconstruction in one embodiment. Detailed Implementation

[0061] The technical solution of the present invention will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0062] In the description of this invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the invention and for 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 invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0063] In the description of this invention, when a specific device is described as being located between a first device and a second device, an intermediary device may or may not be present between the specific device and the first or second device. When a specific device is described as being connected to other devices, the specific device may be directly connected to the other devices without an intermediary device, or it may not be directly connected to the other devices but may have an intermediary device.

[0064] Techniques, methods, and equipment known to those skilled in the art may not be discussed in detail, but where appropriate, such techniques, methods, and equipment should be considered part of the specification.

[0065] Example 1:

[0066] Combination Figure 1 This embodiment 1 provides a steam turbine thermodynamic system based on state reconfiguration, including at least one first working cylinder and at least one second working cylinder. One first working cylinder and a corresponding second working cylinder form a reconfiguration cylinder group. The reconfiguration cylinder group is configured to control one of the working cylinders to be coupled into the thermodynamic working shaft system based on the load condition factor, while the other working cylinder is decoupled from the thermodynamic working shaft system.

[0067] Specifically, when the load condition factor is higher than a certain benchmark value, the first working cylinder is coupled into the thermodynamic working shaft system, while the second working cylinder is decoupled; when the load condition factor is lower than the benchmark value, the second working cylinder is coupled into the thermodynamic working shaft system, while the first working cylinder is decoupled. In this way, the structure and operating parameters of the thermal system can be dynamically adjusted according to changes in load demand, maintaining high operating efficiency at all times.

[0068] In one implementation, the number of reconfigurable cylinder groups is greater than 1. The reconfigurable cylinder groups are divided according to the pressure operating range, into high-pressure reconfigurable cylinder groups and low-pressure reconfigurable cylinder groups. The load condition factor control judgment benchmark values ​​corresponding to different reconfigurable cylinder groups are different. Preferably, the load condition factor control judgment benchmark value is the pressure value or the load rate.

[0069] As another implementation, the number of reconfigurable cylinder groups is greater than 1. The reconfigurable cylinder groups are divided according to the pressure operating range, into high-pressure reconfigurable cylinder groups and low-pressure reconfigurable cylinder groups. The load condition factor control judgment benchmark values ​​corresponding to different reconfigurable cylinder groups are the same. Preferably, the load condition factor control judgment benchmark value is the pressure value or the load rate.

[0070] In one implementation, the first and second working cylinders in the same reconfigurable cylinder group are arranged coaxially, that is, the same reconfigurable cylinder group uses a thermodynamic working shaft system. When a working cylinder is engaged, it is connected to the end of this thermodynamic working shaft system through the corresponding clutch, while the working cylinders that do not need to be engaged are decoupled from the end of this thermodynamic working shaft system by controlling the corresponding clutch.

[0071] The advantages of coaxial arrangement are:

[0072] 1. Space and cost efficiency: Coaxial arrangement reduces the required space because the two power cylinders share a single power shaft system, reducing the need for additional shafts. This arrangement helps simplify the construction, thereby also helping to reduce manufacturing and maintenance costs.

[0073] 2. Simplified structure: Compared with a multi-shaft design, sharing a single thermal power shaft system can simplify mechanical design and construction, reduce system complexity, and help improve system reliability and reduce failure rate.

[0074] 3. Ease of maintenance: Due to the coaxial arrangement of the power cylinder and shaft system, maintenance work (such as inspection and replacement of parts) will be more centralized and convenient, reducing the difficulty and cost of maintenance during long-term operation.

[0075] As another implementation, the first and second working cylinders in the same reconfigurable cylinder group are arranged in opposite directions, that is, the two working cylinders in the same reconfigurable cylinder group are respectively connected to two thermodynamic working shaft systems, and the coupling and decoupling relationship between the working cylinder and the corresponding thermodynamic working shaft system is controlled based on the load condition factor.

[0076] The advantages of off-axis arrangement are:

[0077] 1. Vibration and thermal stress management: Separate shaft systems allow for better control of vibration and transmitted thermal stress, thereby reducing mechanical fatigue and extending equipment life.

[0078] 2. Scalability and Modularity: The off-axis arrangement offers greater flexibility when the system needs to be upgraded or expanded in the future. New power cylinders and shafts can be added independently to meet new energy demands without requiring significant modifications to the existing system.

[0079] 3. Flexibility in operation and maintenance: The off-axis arrangement allows each power cylinder to be maintained and repaired independently without affecting the operation of the other shaft system. This greatly reduces potential downtime during maintenance and improves production efficiency.

[0080] In both of the above embodiments, the first and / or second working cylinders in the same reconfigurable cylinder bank are connected to the ends of their corresponding thermodynamic working shafts via clutches. The clutches allow the working cylinders to be quickly coupled or decoupled from the thermodynamic working shafts, providing extremely high flexibility and responsiveness. Clutch connection also makes switching between working cylinders faster and more flexible. When load demands change, the appropriate working cylinder can be quickly selected via the clutch without complex operations, thereby improving the system's response speed and adaptability. This design allows the system to rapidly adjust its operating state according to changes in load conditions, improving its response speed to load changes. The clutches effectively control mechanical stress during engagement and disengagement, reducing wear and impact that may be caused by direct mechanical connections, extending equipment lifespan, and reducing maintenance costs. It also enhances modularity and scalability, allowing the addition of new working cylinders or system upgrades without affecting existing operations.

[0081] In this embodiment, under rated operating conditions, similar pressure level enthalpy drop design schemes are adopted. The first and second working cylinders in the same reconfigurable cylinder group have different pressure levels. The flow characteristics of one working cylinder are equivalent to the flow characteristics of the corresponding pressure level in the front or rear region of the other working cylinder.

[0082] Different pressure levels of the working cylinder can flexibly cope with different operating pressure and temperature conditions, enabling the system to work effectively over a wide range of operating conditions. For example, when the grid load is low, the low-pressure level working cylinder can be used to reduce steam loss and improve thermal efficiency; while under high load demand, it can be switched to the high-pressure level working cylinder to provide higher power output.

[0083] Matching the flow characteristics of one working cylinder to the pressure stage of another helps to more effectively distribute and utilize steam between the two cylinders. The flow characteristics of the working cylinders affect the steam flow rate and pressure drop. If the flow characteristics of the two working cylinders are matched, it ensures that pressure and temperature losses are minimized during steam transfer. This precise matching means that more of the steam's thermal energy can be converted into mechanical energy during its expansion, thereby improving the efficiency of the entire system. By precisely controlling the utilization of steam, the system can achieve higher thermal efficiency and reduce energy waste.

[0084] When electricity demand changes, the system needs to be able to respond quickly to these changes to maintain operating efficiency. By ensuring the flow characteristics are matched between the working cylinders, the operating status of each cylinder can be adjusted more flexibly to adapt to load changes. This design enables the system to transition quickly and stably when switching loads, improving the system's adaptability to load fluctuations and its dynamic performance.

[0085] It should be noted that in some possible embodiments, without adopting similar pressure stage enthalpy drop design schemes, the pressure stages of the first and second working cylinders in the same reconfigurable cylinder group can be designed arbitrarily, including both the same and different cases.

[0086] Working principle explanation:

[0087] Under high-load conditions, the load factor is higher than the baseline value. At this time, the first working cylinder is coupled to the thermodynamic working shaft system, while the second working cylinder is decoupled. Steam mainly expands and performs work in the first working cylinder, and the system operates at a larger flow rate to meet the high-load demand.

[0088] Under low-load conditions, the load factor is below the baseline value. At this time, the second working cylinder is coupled to the thermodynamic working shaft system, while the first working cylinder is decoupled. Steam mainly expands and performs work in the second working cylinder, and the system operates at a smaller flow rate to meet low-load demands.

[0089] During load condition transitions, the clutch action enables rapid switching between the first and second power cylinders, ensuring smooth system operation.

[0090] Example 2:

[0091] Combination Figure 1 This embodiment 2 provides a steam turbine thermodynamic system based on state reconstruction. Based on embodiment 1, it further includes an intermediate-pressure cylinder 1, a first working cylinder body is a first low-pressure cylinder 2, and a second working cylinder body is a second low-pressure cylinder 4. The first low-pressure cylinder 2 and the second low-pressure cylinder 4 form a low-pressure reconstruction cylinder group. The steam inlet end of the first low-pressure cylinder 2 is connected to the steam outlet end of the intermediate-pressure cylinder 1 through a first valve 3, and the steam inlet end of the second low-pressure cylinder 4 is connected to the steam outlet end of the intermediate-pressure cylinder 1 through a second valve 5. The first valve 3 and the second valve 5 can be selectively opened and closed to control the steam flow to the first low-pressure cylinder 2 or the second low-pressure cylinder 4.

[0092] In this embodiment, a similar pressure stage enthalpy drop design scheme is adopted under rated operating conditions. The number of pressure stages in the second low-pressure cylinder 4 is less than that in the first low-pressure cylinder 2, and the flow characteristics of the second low-pressure cylinder 4 are comparable to those of the corresponding pressure stage in the front region of the first low-pressure cylinder 2. This allows for full utilization of the work capacity of the entire area of ​​the second low-pressure cylinder 4 under low-load conditions, thereby improving steam utilization.

[0093] In terms of arrangement, the first low-pressure cylinder 2 and the second low-pressure cylinder 4 are arranged coaxially or off-axis. At the same time, the first low-pressure cylinder 2 and / or the second low-pressure cylinder 4 are connected to the end of their corresponding thermodynamic working shaft system through a low-pressure stage clutch 7.

[0094] In one embodiment, the intermediate pressure cylinder 1 and the first low pressure cylinder 2 are arranged coaxially. The first low pressure cylinder 2 is connected to the end of the first thermodynamic power-operating shaft system through the low pressure stage clutch 7. The second low pressure cylinder 4 is arranged on the second thermodynamic power-operating shaft system and is arranged off-axis.

[0095] In one embodiment, the intermediate-pressure cylinder 1 and the second low-pressure cylinder 4 are arranged coaxially. The second low-pressure cylinder 4 is connected to the end of the first thermodynamic power-operating shaft system through a low-pressure stage clutch 7. The first low-pressure cylinder 2 is arranged on the second thermodynamic power-operating shaft system and is arranged on opposite shafts.

[0096] Working principle:

[0097] Under high load conditions, the first valve 3 is opened and the second valve 5 is closed. After steam is discharged from the intermediate pressure cylinder 1, it mainly enters the first low pressure cylinder 2 to do work, and the system operates at a large flow rate.

[0098] Under low load conditions, the second valve 5 is opened and the first valve 3 is closed. After steam is discharged from the intermediate pressure cylinder 1, it mainly enters the second low pressure cylinder 4 to do work, and the system operates at a relatively small flow rate.

[0099] By switching valves and operating the clutch, the state of the low-pressure cylinder can be reconfigured to adapt to different load requirements.

[0100] Example 3:

[0101] Combination Figure 1 This embodiment 3 provides a steam turbine thermodynamic system based on state reconstruction. Based on embodiment 1, it further includes a boiler 8 and a reheater 13. The boiler 8 is used to generate main steam, and the reheater 13 is located in the boiler 8 to reheat the steam. Specifically, the first working cylinder is a first high-pressure cylinder 9, and the second working cylinder is a second high-pressure cylinder 10. The first high-pressure cylinder 9 and the second high-pressure cylinder 10 form a high-pressure reconstruction cylinder group. The steam inlet of the first high-pressure cylinder 9 is connected to the main steam through a third valve 11, and the steam exhaust of the first high-pressure cylinder 9 is connected to the reheater 13 through a fourth valve 12. The steam inlet of the second high-pressure cylinder 10 is connected to the main steam through a fifth valve 14, and the steam exhaust of the second high-pressure cylinder 10 is connected to the reheater 13 through a sixth valve 15. The third valve 11, the fourth valve 12, the fifth valve 14, and the sixth valve 15 can be selectively opened and closed to control the main steam flow to the first high-pressure cylinder 9 or the second high-pressure cylinder 10, and the steam exhaust of the high-pressure cylinder to the reheater 13.

[0102] In this embodiment, a similar pressure stage enthalpy drop design scheme is adopted under rated operating conditions. The second high-pressure cylinder 10 has more pressure stages than the first high-pressure cylinder 9, and the flow characteristics of the first high-pressure cylinder 9 are comparable to the flow characteristics of the corresponding pressure stage in the rear region of the second high-pressure cylinder 10. This allows for full utilization of the overall work capacity of the second high-pressure cylinder 10 under high-load conditions, thereby improving the main steam utilization rate.

[0103] In terms of arrangement, the first high-pressure cylinder 9 and the second high-pressure cylinder 10 are arranged coaxially or off-axis. At the same time, the first high-pressure cylinder 9 and / or the second high-pressure cylinder 10 are connected to the end of their corresponding thermodynamic power-operating shaft system through a high-pressure stage clutch 16.

[0104] Working principle:

[0105] Under high load conditions, open the third valve 11 and the fourth valve 12, close the fifth valve 14 and the sixth valve 15, and the main steam mainly enters the first high-pressure cylinder 9 to do work, and the exhaust steam enters the reheater 13 for reheating.

[0106] Under low load conditions, open the fifth valve 14 and the sixth valve 15, close the third valve 11 and the fourth valve 12, and the main steam mainly enters the second high-pressure cylinder 10 to do work, and the exhaust steam enters the reheater 13 for reheating.

[0107] By switching valves and operating the clutch, the state of the high-pressure cylinder can be reconfigured to adapt to different load requirements while ensuring the stability of reheat steam parameters.

[0108] Example 4:

[0109] This embodiment 4 provides a design method for the steam turbine thermal system applied in embodiment 2. Under rated operating conditions, a similar pressure-stage enthalpy drop design scheme is adopted. The design pressure of the condenser 6 is set to P under 100% rated load conditions. n The rated inlet pressure of the first low-pressure cylinder 2 is P. L1 The rated steam inlet flow rate of the first low-pressure cylinder 2 is m³ / s. L1 The load condition factor control judgment benchmark value for determining state reconfiguration is the load rate L. x1 ;

[0110] With load factor L x1 The operating condition is the rated load condition of the second low-pressure cylinder 4. The rated inlet steam mass flow rate m of the second low-pressure cylinder 4 is verified and determined. L2 and rated inlet steam pressure P L2 ;

[0111] Based on the inlet steam mass flow rate m L2 Rated inlet steam pressure P L2 Condenser 6 pressure P n The flow passage structure of the second low-pressure cylinder 4 was verified.

[0112] By setting a rated load condition for the second low-pressure cylinder 4 based on the actual operating data of the first low-pressure cylinder 2, the performance requirements of the steam turbine at different operating points can be matched more accurately. This method allows the second low-pressure cylinder 4 to operate within its optimal operating range, maximizing thermal efficiency and output power while reducing energy waste. Specifically, by adjusting the inlet steam mass flow rate and pressure, the second low-pressure cylinder 4 can maintain optimal steam expansion efficiency under different loads.

[0113] Used load factor L x1 As a design and verification benchmark, the design of the second low-pressure cylinder 4 is adapted to varying load conditions. This adaptability is achieved by ensuring optimized performance under different operating loads, enhancing the turbine's responsiveness to changes in grid demand.

[0114] By ensuring that the second low-pressure cylinder 4 operates efficiently at a load point customized according to actual operating conditions, mechanical damage caused by excessive wear or improper operation can be reduced. The design, adaptable to different loads, reduces the need for frequent mechanical adjustments and maintenance, thereby extending equipment life and lowering maintenance costs.

[0115] Example 5:

[0116] This embodiment 5 provides a design method for the steam turbine thermal system applied in embodiment 3. Under rated operating conditions, a similar pressure stage enthalpy drop design scheme is adopted. Under 100% rated load conditions, the rated main steam flow rate of the first high-pressure cylinder 9 is m1, the rated main steam pressure of the first high-pressure cylinder 9 is P1, and the rated exhaust pressure of the first high-pressure cylinder 9 is P. b The load condition factor control judgment benchmark value for determining state reconfiguration is the load rate L. x2 ;

[0117] With load factor L x2 The operating condition is the rated load condition of the second high-pressure cylinder 10. The rated main steam flow rate m2 of the second high-pressure cylinder 10 is verified and determined, and the rated exhaust pressure P of the second high-pressure cylinder 10 is verified and determined. b2 ;

[0118] Based on the rated main steam flow rate m2, rated inlet steam pressure P1, and rated outlet steam pressure P... b2 The flow passage structure of the second high-pressure cylinder 10 was verified and designed.

[0119] By setting a specific load rate L for the second high-pressure cylinder 10 with reference to the first high-pressure cylinder 9. x2 This design approach allows the second high-pressure cylinder 10 to be optimized for different operational needs. This flexibility enables the turbine to operate effectively under various conditions, especially in power systems with large load variations, allowing it to quickly adapt to changes in demand and maintain efficient operation.

[0120] The main steam flow rate m2 and exhaust pressure P of the second high-pressure cylinder 10 were precisely calibrated. b2 This ensures that the operating parameters of the cylinder are best suited to its design load.

[0121] This design strategy, by reassessing and setting the inlet and outlet pressures of the second high-pressure cylinder 10 based on actual operating data, contributes to a more rational steam flow and pressure distribution. This not only improves steam utilization efficiency but also reduces heat loss and mechanical stress, thereby extending the service life of the equipment.

[0122] Example 6:

[0123] This embodiment 6 provides an operation method for the steam turbine thermal system in the above embodiment 1:

[0124] Select a set of reconfigurable cylinder groups, set the load condition factor control judgment benchmark value corresponding to the reconfigurable cylinder group to L0, and the load fluctuation range of the transition zone to ΔL0. Set the high load condition to (L0+ΔL0, A0%), the low load condition to [B0%, L0-ΔL0], the upper transition zone load condition to (L0, L0+ΔL0], and the lower transition zone load condition to (L0-ΔL0, L0].

[0125] Determine the current load condition range of the load condition factor;

[0126] If under high load conditions, the first working cylinder in the reconfigured cylinder group is coupled into the thermodynamic working shaft system, and the second working cylinder is decoupled from the thermodynamic working shaft system;

[0127] If under low load conditions, the second working cylinder in the reconfigured cylinder group is coupled into the thermodynamic working shaft system, and the first working cylinder is decoupled from the thermodynamic working shaft system.

[0128] Under the upper transition zone load condition, if the unit is in a variable load process, the unit structure remains unchanged; if it is in a steady state condition, the high load condition shall be followed.

[0129] Under the lower transition zone load condition, if the unit is in a variable load process, the unit structure remains unchanged; if it is in a steady state condition, the low load condition shall be followed.

[0130] It should be noted that the load condition factor control judgment benchmark value L0 for different reconfigurable cylinder groups can be the same or different, and this embodiment does not impose any restrictions.

[0131] Example 7:

[0132] This embodiment 7 provides an operation method for the steam turbine thermal system in embodiment 2 above:

[0133] For the low-pressure reconfiguration cylinder group, the corresponding load condition factor control judgment benchmark value is set to L1, and the load fluctuation range ΔL1 in the transition zone is set.

[0134] The high load condition is set as (L1+ΔL1, A1%), the low load condition as [B1%, L1-ΔL1], the upper transition zone load condition as (L1, L1+ΔL1], and the lower transition zone load condition as (L1-ΔL1, L1].

[0135] Determine the current load condition range of the load condition factor;

[0136] If under high load conditions, open the first valve 3 and close the second valve 5, so that steam passes through the intermediate pressure cylinder 1 and the first low pressure cylinder 2 in sequence.

[0137] If under low load conditions, open the second valve 5 and close the first valve 3, so that steam passes through the intermediate pressure cylinder 1 and enters the second low pressure cylinder 4;

[0138] Under the upper transition zone load condition, if the unit is in a variable load process, the unit structure remains unchanged; if it is in a steady state condition, the high load condition shall be followed.

[0139] Under the lower transition zone load condition, if the unit is in a variable load process, the unit structure remains unchanged; if it is in a steady state condition, the low load condition shall be followed.

[0140] Example 8:

[0141] This embodiment 8 provides an operation method for the steam turbine thermal system in the above embodiment 3:

[0142] For the high-pressure reconfiguration cylinder group, the corresponding load condition factor control judgment benchmark value is set to L2, and the load fluctuation range ΔL2 in the transition zone is set.

[0143] The high load condition is set as (L2+ΔL2, A2%), the low load condition as [B2%, L2-ΔL2], the upper transition zone load condition as (L2, L2+ΔL2], and the lower transition zone load condition as (L2-ΔL2, L2].

[0144] Determine the current load condition range of the load condition factor;

[0145] If under high load conditions, open the third valve 11 and the fourth valve 12, and close the fifth valve 14 and the sixth valve 15 to allow the main steam to directly enter the first high-pressure cylinder 9 and then be discharged into the reheater 13;

[0146] If under low load conditions, open the fifth valve 14 and the sixth valve 15, and close the third valve 11 and the fourth valve 12 to allow the main steam to directly enter the second high-pressure cylinder 10 and then be discharged into the reheater 13.

[0147] Under the upper transition zone load condition, if the unit is in a variable load process, the unit structure remains unchanged; if it is in a steady state condition, the high load condition shall be followed.

[0148] Under the lower transition zone load condition, if the unit is in a variable load process, the unit structure remains unchanged; if it is in a steady state condition, the low load condition shall be followed.

[0149] In Examples 6, 7, and 8, by setting the load fluctuation range ΔL in the transition zone and the corresponding upper and lower transition zones, the turbine thermodynamic system can be adjusted more precisely to adapt to changing load conditions.

[0150] As one implementation method, in actual operation, the turbine load state changes with demand. The system monitors the current load condition factor in real time and determines its load condition range (high load, low load, upper transition zone, lower transition zone, etc.). These ranges are set based on previously defined benchmark values ​​(L0, L1, L2) and their corresponding transition zone load fluctuation ranges (ΔL0, ΔL1, ΔL2). Therefore, based on embodiments 6, 7, and 8, this implementation method, in order to further improve the safety, stability, and efficiency of the regulation process, sets certain control algorithms and control schemes when the load approaches the load condition factor control judgment benchmark values ​​(such as L0, L1, L2). For example, it sets the overlap of reconfiguration cylinder switching and sets the boundary zone load fluctuation range. Specifically:

[0151] Overlap setting for reconfigurable cylinder group switching: In order to reduce the impact on system stability during load switching, the overlap of switching between different reconfigurable cylinder groups is set. This means that while switching one cylinder group, another cylinder group will partially intervene to smooth the transition and avoid system vibration or instability caused by sudden load changes.

[0152] Setting the load fluctuation range in the boundary zone: When determining the current load status, the system will adjust its operation according to the set upper and lower transition zone load fluctuation ranges, which helps to maintain the system's flexibility and response speed during load changes.

[0153] The above embodiments are merely preferred embodiments of the present invention and should not be construed as limiting the scope of protection of the present invention. Any non-substantial changes and substitutions made by those skilled in the art based on the present invention shall fall within the scope of protection claimed by the present invention.

Claims

1. A steam turbine thermodynamic system based on state reconfiguration, characterized in that, It includes at least one first working cylinder and at least one second working cylinder, wherein one first working cylinder and a corresponding second working cylinder form a reconfigurable cylinder group, the reconfigurable cylinder group being configured to control one of the working cylinders to couple into the thermodynamic working shaft system based on a load condition factor, while the other working cylinder is decoupled from the thermodynamic working shaft system; When the load condition factor is higher than a certain reference value, the first working cylinder in the reconfigured cylinder group is coupled into the thermodynamic working shaft system, and the second working cylinder is decoupled from the thermodynamic working shaft system. When the load condition factor is lower than the benchmark value, the second working cylinder in the reconfigured cylinder group is coupled into the thermodynamic working shaft system, and the first working cylinder is decoupled from the thermodynamic working shaft system.

2. The steam turbine thermodynamic system based on state reconstruction as described in claim 1, characterized in that, The number of reconfigurable cylinder groups is greater than 1, and the load condition factor control judgment benchmark values ​​corresponding to different reconfigurable cylinder groups are different.

3. The steam turbine thermodynamic system based on state reconstruction as described in claim 1, characterized in that, The number of reconfigurable cylinder groups is greater than 1, and the load condition factor control judgment benchmark values ​​corresponding to different reconfigurable cylinder groups are the same.

4. The steam turbine thermodynamic system based on state reconstruction as described in claim 1, characterized in that, The first power cylinder and the second power cylinder in the same reconfigurable cylinder group are arranged coaxially or off-axis.

5. A steam turbine thermodynamic system based on state reconfiguration as described in any one of claims 1 to 4, characterized in that, The first working cylinder and / or the second working cylinder in the same reconfigurable cylinder group are connected to the end of their corresponding thermodynamic working shaft system via a clutch.

6. A steam turbine thermodynamic system based on state reconfiguration as described in any one of claims 1 to 4, characterized in that, The first and second working cylinders in the same reconfigurable cylinder group have different pressure levels, and the flow characteristics of one working cylinder are equivalent to the flow characteristics of the corresponding pressure level in the front or rear region of the other working cylinder.

7. A steam turbine thermodynamic system based on state reconstruction as described in claim 1, characterized in that, It also includes an intermediate-pressure cylinder, the first working cylinder body is a first low-pressure cylinder, the second working cylinder body is a second low-pressure cylinder, the steam inlet of the first low-pressure cylinder is connected to the steam outlet of the intermediate-pressure cylinder through a first valve, and the steam inlet of the second low-pressure cylinder is connected to the steam outlet of the intermediate-pressure cylinder through a second valve. The first valve and the second valve can be selectively opened and closed.

8. A steam turbine thermodynamic system based on state reconstruction as described in claim 7, characterized in that, The second low-pressure cylinder has fewer pressure stages than the first low-pressure cylinder, and the flow characteristics of the second low-pressure cylinder are comparable to the flow characteristics of the corresponding pressure stage in the front region of the first low-pressure cylinder.

9. A steam turbine thermodynamic system based on state reconstruction as described in claim 8, characterized in that, The first low-pressure cylinder and the second low-pressure cylinder are arranged coaxially or off-axis.

10. A steam turbine thermodynamic system based on state reconstruction as described in claim 9, characterized in that, The first low-pressure cylinder and / or the second low-pressure cylinder are connected to the end of their corresponding thermodynamic power-operating shaft system via a low-pressure stage clutch.

11. A steam turbine thermodynamic system based on state reconfiguration as described in claim 7 or 8, characterized in that, The intermediate-pressure cylinder and the first low-pressure cylinder are arranged coaxially. The first low-pressure cylinder is connected to the end of the first thermodynamic power-operating shaft system through a low-pressure stage clutch, and the second low-pressure cylinder is arranged in the second thermodynamic power-operating shaft system.

12. A steam turbine thermodynamic system based on state reconstruction as described in claim 7 or 8, characterized in that, The intermediate-pressure cylinder and the second low-pressure cylinder are arranged coaxially. The second low-pressure cylinder is connected to the end of the first thermodynamic power-operating shaft system through a low-pressure stage clutch. The first low-pressure cylinder is arranged on the second thermodynamic power-operating shaft system.

13. A steam turbine thermodynamic system based on state reconstruction as described in claim 1, characterized in that, It also includes a reheater. The first working cylinder is a first high-pressure cylinder, and the second working cylinder is a second high-pressure cylinder. The steam inlet of the first high-pressure cylinder is connected to the main steam through a third valve, and the steam exhaust of the first high-pressure cylinder is connected to the reheater through a fourth valve. The steam inlet of the second high-pressure cylinder is connected to the main steam through a fifth valve, and the steam exhaust of the second high-pressure cylinder is connected to the reheater through a sixth valve. The third, fourth, fifth, and sixth valves can be selectively opened and closed.

14. A steam turbine thermodynamic system based on state reconstruction as described in claim 13, characterized in that, The second high-pressure cylinder has more pressure stages than the first high-pressure cylinder, and the flow characteristics of the first high-pressure cylinder are comparable to the flow characteristics of the corresponding pressure stages in the rear region of the second high-pressure cylinder.

15. A steam turbine thermodynamic system based on state reconstruction as described in claim 14, characterized in that, The first high-pressure cylinder and the second high-pressure cylinder are arranged coaxially or off-axis.

16. A steam turbine thermodynamic system based on state reconstruction as described in claim 15, characterized in that, The first high-pressure cylinder and / or the second high-pressure cylinder are connected to the end of their corresponding thermodynamic power-operating shaft system via a high-pressure stage clutch.

17. A design method for a steam turbine thermodynamic system as described in any one of claims 7 to 12, characterized in that, The design pressure of the condenser is set at 100% rated load. P n The rated inlet pressure of the first low-pressure cylinder is P L1 The rated steam flow rate of the first low-pressure cylinder is m L1 The load condition factor control judgment benchmark value for determining state reconfiguration is the load rate. L x1 ; By load factor L x1 The operating condition is the rated load condition of the second low-pressure cylinder. The rated inlet steam mass flow rate of the second low-pressure cylinder is verified and determined. m L2 and rated inlet steam pressure P L2 ; Based on the inlet steam mass flow rate m L2 Rated inlet steam pressure P L2 and condenser pressure P n The flow passage structure of the second low-pressure cylinder was verified.

18. A design method for a steam turbine thermodynamic system as described in any one of claims 13 to 16, characterized in that, Under 100% rated load conditions, the rated main steam flow rate of the first high-pressure cylinder is: m 1. The rated main steam pressure of the first high-pressure cylinder is: P 1. The rated exhaust pressure of the first high-pressure cylinder is: P b The load condition factor control judgment benchmark value for determining state reconfiguration is the load rate. L x2 ; By load factor L x2 The operating condition is the rated load condition of the second high-pressure cylinder. The rated main steam flow rate of the second high-pressure cylinder is verified and determined. m 2. Verify and determine the rated exhaust pressure of the second high-pressure cylinder. P b2 ; Based on the rated main steam flow m 2. Rated inlet steam pressure P 1 and rated exhaust pressure P b2 The flow passage structure of the second high-pressure cylinder was checked and designed.

19. An operating method for a steam turbine thermal system as described in any one of claims 1 to 6, characterized in that, Select a set of reconfigurable cylinder groups, and set the load condition factor control judgment benchmark value corresponding to the reconfigurable cylinder group as the load rate. L 0, and the load fluctuation range Δ in the transition zone L 0, set the high load condition as ( L 0+Δ L [0, A0%], low load condition is [B0%, L 0-Δ L 0], the upper transition zone load condition is ( L 0, L 0+Δ L 0], the load condition in the lower transition zone is ( L 0-Δ L 0, L 0]; Determine the current load condition range of the load condition factor; If under high load conditions, the first working cylinder in the reconfigured cylinder group is coupled into the thermodynamic working shaft system, and the second working cylinder is decoupled from the thermodynamic working shaft system; If under low load conditions, the second working cylinder in the reconfigured cylinder group is coupled into the thermodynamic working shaft system, and the first working cylinder is decoupled from the thermodynamic working shaft system. Under the upper transition zone load condition, if the unit is in a variable load process, the unit structure remains unchanged; if it is in a steady state condition, the high load condition shall be followed. Under the lower transition zone load condition, if the unit is in a variable load process, the unit structure remains unchanged; if it is in a steady state condition, the low load condition shall be followed.

20. A method for operating a steam turbine thermal system as described in any one of claims 7 to 12, characterized in that, For the low-pressure reconfiguration cylinder group, the corresponding load condition factor control judgment benchmark value is set as the load rate. L 1 ， and the load fluctuation range Δ in the transition zone L 1; Set the high-load operating condition as ( L 1+Δ L 1, A1%], low load condition is [B1%, L 1-Δ L 1], the load condition in the upper transition zone is ( L 1, L 1+Δ L 1], the load condition in the lower transition zone is ( L 1-Δ L 1, L 1]; Determine the current load condition range of the load condition factor; If under high load conditions, open the first valve and close the second valve to allow steam to pass through the intermediate pressure cylinder and the first low pressure cylinder in sequence; If under low load conditions, open the second valve and close the first valve to allow steam to pass through the intermediate pressure cylinder and then enter the second low pressure cylinder; Under the upper transition zone load condition, if the unit is in a variable load process, the unit structure remains unchanged; if it is in a steady state condition, the high load condition shall be followed. Under the lower transition zone load condition, if the unit is in a variable load process, the unit structure remains unchanged; if it is in a steady state condition, the low load condition shall be followed.

21. A method for operating a steam turbine thermal system as described in any one of claims 13 to 16, characterized in that, For the high-pressure reconfiguration cylinder group, the corresponding load condition factor control judgment benchmark value is set as the load rate. L 2, and the load fluctuation range Δ in the transition zone L 2; Set the high-load operating condition as ( L 2+Δ L 2, A2%], low load condition is [B2%, L 2-Δ L 2]; The load condition in the upper transition zone is ( L 2, L 2+Δ L 2], the load condition in the lower transition zone is ( L 2-Δ L 2, L 2]; Determine the current load condition range of the load condition factor; If under high load conditions, open the third and fourth valves and close the fifth and sixth valves to allow the main steam to directly enter the first high-pressure cylinder and then be discharged into the reheater; If under low load conditions, open the fifth and sixth valves and close the third and fourth valves to allow the main steam to directly enter the second high-pressure cylinder and then be discharged into the reheater; Under the upper transition zone load condition, if the unit is in a variable load process, the unit structure remains unchanged; if it is in a steady state condition, the high load condition shall be followed. Under the lower transition zone load condition, if the unit is in a variable load process, the unit structure remains unchanged; if it is in a steady state condition, the low load condition shall be followed.

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