Steam turbine system

Abstract

The invention relates to a steam turbine system which comprises a first high-pressure cylinder and a second high-pressure cylinder, each high-pressure cylinder communicates with a boiler, and the steam bearing load capacity of the first high-pressure cylinder is larger than that of the second high-pressure cylinder; the at least one medium-pressure cylinder is communicated with the boiler; at least one pair of low-pressure cylinders, wherein each pair of low-pressure cylinders is communicated with one medium-pressure cylinder; under the condition that the main steam flow of the steam turbine system is larger than a first preset main steam flow threshold value, main steam generated by the boiler flows to the first high-pressure cylinder till the first high-pressure cylinder is filled with the main steam, the remaining main steam flows to the second high-pressure cylinder, and reheat steam flows to at least one intermediate-pressure cylinder till the second high-pressure cylinder is filled with the reheat steam; and secondary reheat steam generated in each medium-pressure cylinder flows to the pair of low-pressure cylinders communicated with the medium-pressure cylinder. By means of the method, the steam turbine can efficiently conduct steam treatment.

Description

Technical Field

[0001] This application relates to the field of automatic control technology, and particularly to a steam turbine system. Background Art

[0002] Unit power generation is a complex energy conversion process, involving the mutual conversion of various energy forms. Taking a coal-fired power unit as an example, a coal-fired power unit mainly consists of a boiler, a steam turbine, a generator and auxiliary systems. Among them, in the boiler, coal is fed into the combustion chamber for combustion, releasing a large amount of heat energy. The feed water in the boiler is heated and evaporated through the heating surface to form high-temperature and high-pressure steam. After the steam enters the steam turbine, it expands on the blades of each stage and drives the blades to rotate, thereby converting heat energy into mechanical energy. The mechanical energy output by the steam turbine is converted into electrical energy through the generator and output to the outside through the transmission line. That is to say, the steam turbine is used to perform energy conversion processing on the obtained steam to realize the normal power generation of the coal-fired power unit.

[0003] In traditional technology, still taking a coal-fired power unit as an example, a coal-fired power unit usually aims at generating more electricity. Therefore, a steam turbine usually has a high-pressure cylinder, an intermediate-pressure cylinder and two low-pressure cylinders, and these cylinders are designed according to the rated working conditions to ensure the maximum efficiency of the steam turbine under the rated working conditions and guarantee the power generation of the coal-fired power unit. Among them, the high-pressure cylinder is located at the front of the steam turbine and is the initial stage for the main steam to enter the cylinder. The exhaust steam of the high-pressure cylinder enters the boiler reheater for heating to generate reheated steam, and the reheated steam enters the intermediate-pressure cylinder to do work. The exhaust steam of the intermediate-pressure cylinder enters the low-pressure cylinder.

[0004] However, the current steam turbine has the problem of inefficient steam treatment. Summary of the Invention

[0005] Based on this, it is necessary to provide a steam turbine system that can efficiently perform steam treatment for the above technical problems.

[0006] In a first aspect, this application provides a steam turbine system, which includes:

[0007] A first high-pressure cylinder and a second high-pressure cylinder, each high-pressure cylinder is respectively connected to the boiler, wherein the steam load-bearing capacity of the first high-pressure cylinder is greater than that of the second high-pressure cylinder;

[0008] At least one intermediate-pressure cylinder, which is connected to the boiler;

[0009] At least one pair of low-pressure cylinders, each pair of low-pressure cylinders is connected to an intermediate-pressure cylinder;

[0010] When the main steam flow rate of the steam turbine system is greater than the first preset main steam flow rate threshold, the main steam generated by the boiler flows to the first high-pressure cylinder to drive the generator blades corresponding to the first high-pressure cylinder to rotate until the first high-pressure cylinder is filled, and the remaining main steam flows to the second high-pressure cylinder to drive the generator blades corresponding to the second high-pressure cylinder to rotate. The secondary main steam flowing out of the first high-pressure cylinder and the second high-pressure cylinder flows back to the boiler, and the boiler heats the secondary main steam to generate reheated steam. The reheated steam flows to at least one intermediate-pressure cylinder to drive the generator blades corresponding to at least one intermediate-pressure cylinder to rotate. The secondary reheated steam generated in each intermediate-pressure cylinder flows to a pair of low-pressure cylinders communicated with the intermediate-pressure cylinder respectively to drive the generator blades corresponding to the communicated pair of low-pressure cylinders to rotate.

[0011] The above steam turbine system includes: a first high-pressure cylinder and a second high-pressure cylinder, each high-pressure cylinder is respectively communicated with the boiler, wherein the steam load-bearing capacity of the first high-pressure cylinder is greater than that of the second high-pressure cylinder; at least one intermediate-pressure cylinder, the intermediate-pressure cylinder is communicated with the boiler; at least one pair of low-pressure cylinders, each pair of low-pressure cylinders is communicated with an intermediate-pressure cylinder; when the main steam flow rate of the steam turbine system is greater than the first preset main steam flow rate threshold, the main steam generated by the boiler is preferentially flowed to the first high-pressure cylinder with a greater steam load-bearing capacity to drive the generator blades corresponding to the first high-pressure cylinder to rotate until the first high-pressure cylinder is filled, and then the remaining main steam is flowed to the second high-pressure cylinder to drive the generator blades corresponding to the second high-pressure cylinder to rotate. The secondary main steam flowing out of the first high-pressure cylinder and the second high-pressure cylinder flows back to the boiler, and the boiler heats the secondary main steam to generate reheated steam. The reheated steam flows to at least one intermediate-pressure cylinder to drive the generator blades corresponding to at least one intermediate-pressure cylinder to rotate. The secondary reheated steam generated in each intermediate-pressure cylinder flows to a pair of low-pressure cylinders communicated with the intermediate-pressure cylinder respectively to drive the generator blades corresponding to the communicated pair of low-pressure cylinders to rotate. In the whole process, by designing two high-pressure cylinders, at least one intermediate-pressure cylinder and at least one pair of low-pressure cylinders to replace one high-pressure cylinder, one intermediate-pressure cylinder and one low-pressure cylinder in the prior art, when the main steam flow rate of the steam turbine system is greater than the first preset main steam flow rate threshold, it is not necessary to make all the steam cylinders work or work simultaneously, reducing the power consumption of the steam turbine system, and thus enabling the steam turbine to maintain a high steam treatment efficiency under non-rated conditions. Brief Description of the Drawings

[0012] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, the drawings in the following description are some embodiments of the present application. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0013] Figure 1Schematic structural diagram of a steam turbine system in an embodiment;

[0014] Figure 2 Schematic diagram of the connection of power bearings of steam pressure cylinders at all levels in a steam turbine system in an embodiment;

[0015] Figure 3 Schematic overall structural diagram of a steam turbine system in a first connection mode in an embodiment;

[0016] Figure 4 Schematic structural diagram of a steam turbine system in a second connection mode in an embodiment;

[0017] Figure 5 Schematic structural diagram of a steam turbine system in a third connection mode in an embodiment. Detailed implementation manners

[0018] For ease of understanding of this application, the following will provide a more comprehensive description of this application with reference to the relevant drawings. Embodiments of this application are shown in the drawings. However, this application can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, these embodiments are provided to make the disclosure of this application more thorough and comprehensive.

[0019] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the technical field to which this application belongs. The terms used in the description of this application herein are only for the purpose of describing specific embodiments and are not intended to limit this application.

[0020] It can be understood that the terms "first", "second", etc. used in this application can be used herein to describe various elements, but these elements are not limited by these terms. These terms are only used to distinguish one element from another. For example, without departing from the scope of this application, the first resistor can be called the second resistor, and similarly, the second resistor can be called the first resistor. Both the first resistor and the second resistor are resistors, but they are not the same resistor.

[0021] It can be understood that in the following embodiments, "connection", if there is an electrical signal or data transfer between the connected circuits, modules, units, etc., should be understood as "electrical connection", "communication connection", etc.

[0022] It can be understood that "at least one" means one or more, and "a plurality" means two or more. "At least part of an element" means part or all of the element.

[0023] As used herein, the singular forms "a", "an" and "the" may also include the plural forms unless the context clearly dictates otherwise. It should also be understood that the terms "comprising", "including" or "having", etc. specify the presence of the stated features, wholes, steps, operations, components, parts or combinations thereof, but do not preclude the possibility of the presence or addition of one or more other features, wholes, steps, operations, components, parts or combinations thereof. At the same time, the term "and / or" used in this specification includes any and all combinations of the related listed items.

[0024] Taking a coal-fired power unit as an example, the power generation of a coal-fired power unit is a complex energy conversion process, involving the mutual conversion of various energy forms. A coal-fired power unit mainly consists of a boiler, a steam turbine, a generator and auxiliary systems. In the boiler, coal is fed into the combustion chamber for combustion, releasing a large amount of heat energy. The feed water in the boiler is heated and evaporated through the heating surface, forming high-temperature and high-pressure steam. After the steam enters the steam turbine, it expands on the blades at all levels and drives the blades to rotate, thereby converting heat energy into mechanical energy. The mechanical energy output by the steam turbine is converted into electrical energy by the generator and output to the outside through the transmission line.

[0025] In the past, when the unit was built, the goal was usually to generate more electricity. Therefore, the steam turbine usually had one high-pressure cylinder, one intermediate-pressure cylinder and two low-pressure cylinders, and these cylinders were designed according to the rated operating conditions to ensure the maximum efficiency of the steam turbine under the rated operating conditions and guarantee the power generation of the unit. Among them, the high-pressure cylinder is located at the front of the steam turbine and is the initial stage for the main steam to enter the cylinder. The exhaust steam from the high-pressure cylinder enters the boiler reheater for heating and then enters the intermediate-pressure cylinder to do work. The exhaust steam from the intermediate-pressure cylinder enters the low-pressure cylinder, and the exhausted steam that does work in the low-pressure cylinder enters the condenser to be condensed into water and then enters the regenerative equipment.

[0026] However, with the development of new energy and the construction of a new power system, coal power is gradually transforming into a regulating and guaranteeing power source. Large-capacity supercritical units are generally operating under non-rated main steam flow rates and cannot fully utilize the advantages of high efficiency at rated load. It is expected that in the future, it will become normal for thermal power units in China to operate at partial loads for a long time, which will affect the actual operating coal consumption of the units. For example, when the steam turbine is under non-rated main steam flow rate, the steam inlet volume of the steam turbine will decrease accordingly, resulting in the mismatch between parameters such as the flow rate, pressure and temperature of the steam and the design values.

[0027] Specifically, the flow rate decreases: When the steam turbine is operating at a non - rated main steam flow rate, due to the reduced external load demand, the steam inlet volume of the steam turbine will also decrease accordingly. However, the steam turbine is designed based on the rated steam inlet volume, and it has a higher efficiency and lower coal consumption under the rated operating conditions. When the steam turbine is operating at a non - rated main steam flow rate, the reduced steam inlet volume leads to a relatively large flow - through area of the steam turbine designed for the rated load. During the sliding - pressure operation at a non - rated main steam flow rate, the inlet steam pressure decreases, resulting in a decrease in the main steam pressure and reheat steam pressure of the steam turbine, and a reduction in the cycle efficiency.

[0028] Pressure and temperature changes: As the steam flow rate decreases, the main steam pressure and temperature may also change. These changes may lead to a decrease in the thermal energy conversion efficiency of the steam, thereby further affecting the performance of the steam turbine.

[0029] In summary, the flow - through area of the steam turbine designed for the rated load is relatively large, suitable for operation at the rated load, with high efficiency and good economy. In recent years, due to the development of new - energy power generation, coal - fired power has been operating at a non - rated main steam flow rate for a long time, and the steam turbine operates at a sliding pressure to a lower pressure, including the main steam pressure, reheat steam pressure, and low - pressure cylinder inlet steam pressure, resulting in a reduction in the thermal cycle efficiency of the steam turbine. Designing the steam turbine based on the rated load can no longer adapt to the current operating load, and this application aims to solve this technical problem.

[0030] Therefore, the traditional design of steam turbines in the past should be reconstructed to adapt to the development and needs of the new power system. The future design of steam turbines should follow the design principle of meeting the high efficiency of the unit during wide - load operation, being able to maintain the power generation efficiency under rated conditions and also maintain a relatively high power generation efficiency under non - rated main steam flow rates, meeting the current situation of the unit operating under wide - load conditions. Among them, wide - load operation means that the unit can operate efficiently and stably within a relatively wide load range (such as 50% - 100% load, or even lower).

[0031] To achieve the high efficiency of the unit under wide load operation, the present application proposes a steam turbine system, including: a first high-pressure cylinder and a second high-pressure cylinder, each high-pressure cylinder is respectively connected to a boiler, wherein the steam load-bearing capacity of the first high-pressure cylinder is greater than that of the second high-pressure cylinder; at least one intermediate-pressure cylinder, the intermediate-pressure cylinder is connected to the boiler; at least a pair of low-pressure cylinders, each pair of low-pressure cylinders is connected to an intermediate-pressure cylinder; when the main steam flow rate of the steam turbine system is greater than the first preset main steam flow rate threshold, the main steam generated by the boiler is preferentially directed to the first high-pressure cylinder with a greater steam load-bearing capacity to drive the generator blades corresponding to the first high-pressure cylinder to rotate. After the first high-pressure cylinder is filled, the remaining main steam is directed to the second high-pressure cylinder to drive the generator blades corresponding to the second high-pressure cylinder to rotate. The secondary main steam flowing out of the first high-pressure cylinder and the second high-pressure cylinder flows back to the boiler, and the boiler heats the secondary main steam to generate reheated steam. The reheated steam flows to at least one intermediate-pressure cylinder to drive the generator blades corresponding to at least one intermediate-pressure cylinder to rotate. The secondary reheated steam generated in each intermediate-pressure cylinder respectively flows to a pair of low-pressure cylinders connected to the intermediate-pressure cylinder to drive the generator blades corresponding to the connected pair of low-pressure cylinders to rotate. In the whole process, by designing two high-pressure cylinders, at least one intermediate-pressure cylinder and at least a pair of low-pressure cylinders to replace one high-pressure cylinder, one intermediate-pressure cylinder and one low-pressure cylinder in the prior art, when the main steam flow rate of the steam turbine system is greater than the first preset main steam flow rate threshold, it is not necessary to make all the steam cylinders work or work simultaneously, reducing the power consumption of the steam turbine system, and thus enabling the steam turbine to maintain a high steam treatment efficiency under non-rated conditions.

[0032] As Figure 1 shown, the steam turbine system 1000 provided by the embodiment of the present application includes:

[0033] A first high-pressure cylinder 110 and a second high-pressure cylinder 120, each high-pressure cylinder is respectively connected to a boiler 200, wherein the steam load-bearing capacity of the first high-pressure cylinder 110 is greater than that of the second high-pressure cylinder 120;

[0034] At least one intermediate-pressure cylinder 300, the intermediate-pressure cylinder 300 is connected to the boiler 200;

[0035] At least a pair of low-pressure cylinders 400, each pair of low-pressure cylinders 400 is connected to an intermediate-pressure cylinder 300;

[0036] When the main steam flow rate of the steam turbine system 1000 is greater than the first preset main steam flow rate threshold, the main steam generated by the boiler 200 flows to the first high-pressure cylinder 110 to drive the corresponding power generation blades of the first high-pressure cylinder 110 to rotate until the first high-pressure cylinder 110 is filled, and the remaining main steam flows to the second high-pressure cylinder 120 to drive the corresponding power generation blades of the second high-pressure cylinder 120 to rotate. The secondary main steam flowing out of the first high-pressure cylinder 110 and the second high-pressure cylinder 120 flows back to the boiler 200, and the boiler 200 heats the secondary main steam to generate reheated steam. The reheated steam flows to at least one intermediate-pressure cylinder 300 to drive the corresponding power generation blades of at least one intermediate-pressure cylinder 300 to rotate. The secondary reheated steam generated in each intermediate-pressure cylinder 300 respectively flows to a pair of low-pressure cylinders 400 communicated with the intermediate-pressure cylinder 300 to drive the corresponding power generation blades of the communicated pair of low-pressure cylinders 400 to rotate.

[0037] Among them, the steam turbine system 1000 is an important part of the power generation unit. After the steam from the boiler 200 enters the steam turbine, the steam expands on the blades at all levels and drives the blades to rotate, thereby converting thermal energy into mechanical energy.

[0038] The high-pressure cylinder is a component of the steam turbine. In the initial stage when the main steam enters the cylinder, the steam at this time is the main steam, with high main steam pressure and temperature. The blades of the high-pressure cylinder are usually shorter and the impeller diameter is larger to adapt to the characteristics of high-pressure and high-temperature steam. The function of the high-pressure cylinder is to convert the high-temperature and high-pressure main steam into mechanical energy to drive the steam turbine to rotate. The intermediate-pressure cylinders 300 and the low-pressure cylinders 400 are the cylinder parts behind the high-pressure cylinder in the steam turbine. After the steam expands and does work initially in the high-pressure cylinder, it enters the boiler 200 again for heating to generate reheated steam. The reheated steam enters the intermediate-pressure cylinders 300 and the low-pressure cylinders 400 to continue expanding and doing work until the thermal energy of the steam is completely converted into mechanical energy.

[0039] The steam load-bearing capacity refers to the maximum steam inlet volume that each steam pressure cylinder can bear. For example, when the steam load-bearing capacity of a certain high-pressure cylinder is 60%, at most 60% of the main steam enters this high-pressure cylinder. The ratio between the steam load-bearing capacity of the first high-pressure cylinder 110 and the steam load-bearing capacity of the second high-pressure cylinder 120 can be 4:6, 5:5, 4.5:5.5, etc. The first high-pressure cylinder 110 and the second high-pressure cylinder 120 cooperate with each other to meet the steam inlet volume of the steam turbine under the rated condition. Similarly, all the intermediate-pressure cylinders 300 or all the low-pressure cylinders 400 cooperate with each other to also meet the steam inlet volume of the steam turbine under the rated condition. The first preset main steam flow rate threshold should be less than the main steam flow rate of the steam turbine under the rated condition.

[0040] Specifically, the original steam turbine system 1000 is provided with a high-pressure cylinder, an intermediate-pressure cylinder 300, and two low-pressure cylinders 400, and these cylinders are designed according to the rated operating conditions. That is to say, the steam turbine can operate efficiently under the rated operating conditions. However, under non-rated operating conditions, the steam inlet of the steam turbine does not match the design value. Therefore, the efficiency of the steam turbine in handling steam under non-rated operating conditions is affected. Therefore, in this application, the structure of the steam turbine in the related art is improved, so that the steam turbine is provided with two parallel high-pressure cylinders, at least one intermediate-pressure cylinder 300, and at least one pair of low-pressure cylinders 400. The two high-pressure cylinders are the first high-pressure cylinder 110 and the second high-pressure cylinder 120, and the steam load-bearing capacity of the first high-pressure cylinder 110 and the steam load-bearing capacity of the second high-pressure cylinder 120 can be adjusted according to the actual situation of the power plant. In this application, it is set that the steam load-bearing capacity of the first high-pressure cylinder 110 is greater than that of the second high-pressure cylinder 120.

[0041] Furthermore, each high-pressure cylinder is respectively connected to the boiler 200 for receiving the main steam generated by the boiler 200. In the boiler 200, coal is fed into the combustion chamber for combustion, releasing a large amount of heat energy. The feed water in the boiler 200 is heated and evaporated through the heating surface to form high-temperature and high-pressure main steam. And the boiler 200 can not only generate main steam but also generate reheated steam.

[0042] Specifically, when the main steam flow rate of the steam turbine system 1000 is greater than the first preset main steam flow rate threshold, the main steam generated by the boiler 200 flows to the first high-pressure cylinder 110 to drive the corresponding power generation blades of the first high-pressure cylinder 110 to rotate until the first high-pressure cylinder 110 is filled, and the remaining main steam flows to the second high-pressure cylinder 120 to drive the corresponding power generation blades of the second high-pressure cylinder 120 to rotate, and it is necessary to meet the minimum steam inlet volume requirement of the second high-pressure cylinder 120. The secondary main steam flowing out of the first high-pressure cylinder 110 and the second high-pressure cylinder 120 flows back to the boiler 200, and the boiler 200 heats the secondary main steam to generate reheated steam. It can be seen that the main steam generated by the boiler 200 preferentially flows to the first high-pressure cylinder 110 with a larger steam load-bearing capacity. After waiting for the main steam to fill the first high-pressure cylinder 110, it flows to the second high-pressure cylinder 120 with a smaller steam load-bearing capacity. If the main steam does not fill the first high-pressure cylinder 110, there is no need to flow to the second high-pressure cylinder 120 with a smaller steam load-bearing capacity, reducing the power consumption of the steam turbine system 1000, and thus enabling the steam turbine to maintain a high steam treatment efficiency under non-rated operating conditions. In practical applications, the role of driving the corresponding power generation blades of the steam cylinder to rotate is to convert heat energy into mechanical energy to achieve the power generation of the steam turbine.

[0043] Moreover, each intermediate-pressure cylinder 300 is connected to the boiler 200. The reheated steam generated by the boiler 200 will flow to at least one intermediate-pressure cylinder 300 to drive the rotation of the generator blades corresponding to at least one intermediate-pressure cylinder 300. At this time, secondary reheated steam will be generated in each intermediate-pressure cylinder 300. It can be seen that the reheated steam generated by the boiler 200 may flow to all the intermediate-pressure cylinders 300 or may flow to some of the intermediate-pressure cylinders 300. Therefore, it is not necessary for all the intermediate-pressure cylinders 300 to operate, reducing the energy consumption of the steam turbine system 1000. Furthermore, the steam turbine can maintain a high steam processing efficiency under off-design conditions.

[0044] Each pair of low-pressure cylinders 400 is connected to an intermediate-pressure cylinder 300. That is to say, each pair of low-pressure cylinders 400 exists in pairs with an intermediate-pressure cylinder 300. When there are two intermediate-pressure cylinders 300, there are two pairs of low-pressure cylinders 400. When there is one intermediate-pressure cylinder 300, there is one pair of low-pressure cylinders 400. After the secondary reheated steam is generated in each intermediate-pressure cylinder 300, the secondary reheated steam generated in each intermediate-pressure cylinder 300 flows to the corresponding connected low-pressure cylinders 400 respectively to drive the rotation of the generator blades corresponding to the low-pressure cylinders 400. When the secondary reheated steam is generated in each intermediate-pressure cylinder 300, the secondary reheated steam cannot flow to the low-pressure cylinders 400 that are not connected to this intermediate-pressure cylinder 300, avoiding the mixing of steam between different cylinders.

[0045] In an exemplary embodiment, the process of setting the steam load-bearing capacity of the first high-pressure cylinder 110 and the steam load-bearing capacity of the second high-pressure cylinder 120 includes: obtaining the actual operating duration of the steam turbine under the rated main steam flow rates of various preset ratios; screening out the rated main steam flow rate of the target ratio with the longest actual operating duration from the rated main steam flow rates of various preset ratios; setting the steam load-bearing capacity of the first high-pressure cylinder 110 that matches the rated main steam flow rate of the target ratio according to the rated main steam flow rate of the target ratio; and setting the steam load-bearing capacity of the second high-pressure cylinder 120 according to the steam load-bearing capacity of the first high-pressure cylinder 110.

[0046] For example, if the actual operation time of the steam turbine at 40% of the rated main steam flow rate is one day, the actual operation time at 50% of the rated main steam flow rate is two days, and the actual operation time at 60% of the rated main steam flow rate is three days, then the rated main steam flow rate of the target ratio with the longest actual operation duration is selected as 60%. At this time, the steam load-bearing capacity of the first high-pressure cylinder 110 is set to match the rated main steam flow rate of the target ratio. That is to say, the steam load-bearing capacity of the first high-pressure cylinder 110 is set to 60%. Since the combination of the steam load-bearing capacity of the first high-pressure cylinder 110 and the steam load-bearing capacity of the second high-pressure cylinder 120 needs to meet the steam inlet volume of the steam turbine under the rated condition, when the steam load-bearing capacity of the first high-pressure cylinder 110 is set to 60%, the steam load-bearing capacity of the second high-pressure cylinder 120 is set to 40%. In other cases, the steam load-bearing capacity of the first high-pressure cylinder 110 can also be set to 50%, and the steam load-bearing capacity of the second high-pressure cylinder 120 can be set to 50%, etc. By determining the rated main steam flow rate of the target ratio with the longest actual operation duration and designing the steam load-bearing capacity of the first high-pressure cylinder 110 and the second high-pressure cylinder 120 with reference to the actual operation duration of the rated main steam flow rate of the unit where the steam turbine is located, the accuracy of setting the steam load-bearing capacity of the first high-pressure cylinder 110 and the second high-pressure cylinder 120 is improved.

[0047] Similarly, in the case where at least one intermediate-pressure cylinder 300 includes two intermediate-pressure cylinders 300 and at least one pair of low-pressure cylinders 400 includes two pairs of low-pressure cylinders 400, the setting process of the steam load-bearing capacity between the two intermediate-pressure cylinders 300 is similar to the setting process of the steam load-bearing capacity of the first high-pressure cylinder 110 and the second high-pressure cylinder 120, and the setting process of the steam load-bearing capacity between the two pairs of low-pressure cylinders 400 is similar to the setting process of the steam load-bearing capacity of the first high-pressure cylinder 110 and the second high-pressure cylinder 120, which will not be elaborated here.

[0048] In the above steam turbine system, there are a first high-pressure cylinder 110 and a second high-pressure cylinder 120. Each high-pressure cylinder is respectively connected to a boiler 200. Among them, the steam load-bearing capacity of the first high-pressure cylinder 110 is greater than that of the second high-pressure cylinder 120; there is at least one intermediate-pressure cylinder 300, and the intermediate-pressure cylinder 300 is connected to the boiler 200; there is at least a pair of low-pressure cylinders 400, and each pair of low-pressure cylinders 400 is connected to an intermediate-pressure cylinder 300; when the main steam flow rate of the steam turbine system 1000 is greater than the first preset main steam flow rate threshold, the main steam generated by the boiler 200 preferentially flows to the first high-pressure cylinder 110 with a greater steam load-bearing capacity to drive the rotation of the generator blades corresponding to the first high-pressure cylinder 110. After the first high-pressure cylinder 110 is filled, the remaining main steam flows to the second high-pressure cylinder 120 to drive the rotation of the generator blades corresponding to the second high-pressure cylinder 120. The secondary main steam flowing out of the first high-pressure cylinder 110 and the second high-pressure cylinder 120 flows back to the boiler 200, and the boiler 200 heats the secondary main steam to generate reheated steam. The reheated steam flows to at least one intermediate-pressure cylinder 300 to drive the rotation of the generator blades corresponding to at least one intermediate-pressure cylinder 300. The secondary reheated steam generated in each intermediate-pressure cylinder 300 respectively flows to a pair of low-pressure cylinders 400 connected to the intermediate-pressure cylinder 300 to drive the rotation of the generator blades corresponding to the connected pair of low-pressure cylinders 400. Throughout the process, by designing two high-pressure cylinders, at least one intermediate-pressure cylinder 300 and at least a pair of low-pressure cylinders 400 to replace one high-pressure cylinder, one intermediate-pressure cylinder 300 and one low-pressure cylinder 400 in the prior art, when the main steam flow rate of the steam turbine system 1000 is greater than the first preset main steam flow rate threshold, it is not necessary to make all the steam cylinders work or work simultaneously, reducing the power consumption of the steam turbine system 1000, and thus enabling the steam turbine to maintain a high steam treatment efficiency under non-rated conditions.

[0049] In an exemplary embodiment, the system further includes:

[0050] When the main steam flow rate of the steam turbine system 1000 is less than the first preset main steam flow rate threshold and greater than the second preset main steam flow rate threshold, the main steam generated by the boiler 200 flows to the first high-pressure cylinder 110 to drive the rotation of the generator blades corresponding to the first high-pressure cylinder 110. The secondary main steam flowing out of the first high-pressure cylinder 110 flows back to the boiler 200, and the boiler 200 heats the secondary main steam to generate reheated steam. The reheated steam flows to at least one intermediate-pressure cylinder 300 to drive the rotation of the generator blades corresponding to at least one intermediate-pressure cylinder 300. The secondary reheated steam generated in each intermediate-pressure cylinder 300 respectively flows to a pair of low-pressure cylinders 400 connected to the intermediate-pressure cylinder 300 to drive the rotation of the generator blades corresponding to the connected pair of low-pressure cylinders 400;

[0051] When the main steam flow rate of the steam turbine system 1000 is less than the second preset main steam flow rate threshold, the main steam generated by the boiler 200 flows to the second high-pressure cylinder 120 to drive the rotation of the generator blades corresponding to the second high-pressure cylinder 120. The secondary main steam flowing out of the second high-pressure cylinder 120 flows back to the boiler 200, and the boiler 200 heats the secondary main steam to generate reheated steam. The reheated steam flows to at least one intermediate-pressure cylinder 300 to drive the rotation of the generator blades corresponding to at least one intermediate-pressure cylinder 300. The secondary reheated steam generated in each intermediate-pressure cylinder 300 flows to a pair of low-pressure cylinders 400 communicated with the intermediate-pressure cylinder 300 respectively to drive the rotation of the generator blades corresponding to the communicated pair of low-pressure cylinders 400.

[0052] Among them, the first preset main steam flow rate threshold and the second preset main steam flow rate threshold are determined according to the steam load-bearing capacity of the first high-pressure cylinder 110 and the steam load-bearing capacity of the second high-pressure cylinder 120. For example, when the steam load-bearing capacity of the first high-pressure cylinder 110 is 60% and the steam load-bearing capacity of the second high-pressure cylinder 120 is 40%, the first preset main steam flow rate threshold can be 60% of the rated main steam flow rate, and the second preset main steam flow rate threshold can be 40% of the rated main steam flow rate; another example is when the steam load-bearing capacity of the first high-pressure cylinder 110 is 70% and the steam load-bearing capacity of the second high-pressure cylinder 120 is 30%, the first preset main steam flow rate threshold can be 70% of the rated main steam flow rate, and the second preset main steam flow rate threshold can be 30% of the rated main steam flow rate.

[0053] Specifically, according to the magnitude relationship among the main steam flow rate, the first preset main steam flow rate threshold, and the second preset main steam flow rate threshold, the steam turbine can be divided into different operating conditions:

[0054] First, when the main steam flow rate of the steam turbine system 1000 is equal to the rated main steam flow rate, the first high-pressure cylinder 110 and the second high-pressure cylinder 120 need to operate simultaneously to meet the steam inlet requirements of the steam turbine system 1000. At this time, the first high-pressure cylinder 110, the second high-pressure cylinder 120, at least one intermediate-pressure cylinder 300, and at least one pair of low-pressure cylinders 400 are all opened. The main steam generated by the boiler 200 flows to the first high-pressure cylinder 110 and the second high-pressure cylinder 120 to drive the generator blades corresponding to the first high-pressure cylinder 110 and the second high-pressure cylinder 120 to rotate. The secondary main steam flowing out of the first high-pressure cylinder 110 and the second high-pressure cylinder 120 flows back to the boiler 200, and the boiler 200 heats the secondary main steam to generate reheated steam. The reheated steam flows to all the intermediate-pressure cylinders 300 to drive the generator blades corresponding to all the intermediate-pressure cylinders 300 to rotate. The secondary reheated steam generated in each intermediate-pressure cylinder 300 respectively flows to a pair of low-pressure cylinders 400 communicated with the intermediate-pressure cylinder 300 to drive the generator blades corresponding to the communicated low-pressure cylinders 400 to rotate. It can be seen that at this time, the steam inlet priorities between the two high-pressure cylinders are equal, and the steam inlet priorities among at least one intermediate-pressure cylinder 300 are equal.

[0055] In some special embodiments, when the main steam flow rate of the steam turbine system 1000 is equal to the rated main steam flow rate, the first high-pressure cylinder 110 can be preferentially opened to direct the main steam generated by the boiler 200 to the first high-pressure cylinder 110 with a larger steam load-bearing capacity to drive the generator blades corresponding to the first high-pressure cylinder 110 to rotate until the first high-pressure cylinder 110 is filled. Then, the second high-pressure cylinder 120 is opened to direct the remaining main steam to the second high-pressure cylinder 120 to drive the generator blades corresponding to the second high-pressure cylinder 120 to rotate until the second high-pressure cylinder 120 is filled. The secondary main steam flowing out of the first high-pressure cylinder 110 and the second high-pressure cylinder 120 flows back to the boiler 200, and the boiler 200 heats the secondary main steam to generate reheated steam. The reheated steam flows to at least one intermediate-pressure cylinder 300 to drive the generator blades corresponding to at least one intermediate-pressure cylinder 300 to rotate. The secondary reheated steam generated in each intermediate-pressure cylinder 300 respectively flows to a pair of low-pressure cylinders 400 communicated with the intermediate-pressure cylinder 300 to drive the generator blades corresponding to the communicated pair of low-pressure cylinders 400 to rotate. At this time, the steam inlet priority of the high-pressure cylinder with a larger steam load-bearing capacity is higher than that of the high-pressure cylinder with a lower steam load-bearing capacity.

[0056] Second, when the main steam flow rate of the steam turbine system 1000 is less than the rated condition and greater than the first preset main steam flow rate threshold, the main steam generated by the boiler 200 flows to the first high-pressure cylinder 110 to drive the corresponding power generation blades of the first high-pressure cylinder 110 to rotate until the first high-pressure cylinder 110 is filled, and the remaining main steam flows to the second high-pressure cylinder 120 to drive the corresponding power generation blades of the second high-pressure cylinder 120 to rotate, and the minimum steam inlet quantity requirement of the second high-pressure cylinder 120 needs to be satisfied. The secondary main steam flowing out of the first high-pressure cylinder 110 and the second high-pressure cylinder 120 flows back to the boiler 200, and the boiler 200 heats the secondary main steam to generate reheated steam. The reheated steam flows to at least one intermediate-pressure cylinder 300 to drive the corresponding power generation blades of at least one intermediate-pressure cylinder 300 to rotate. The secondary reheated steam generated in each intermediate-pressure cylinder 300 respectively flows to a pair of low-pressure cylinders 400 communicated with the intermediate-pressure cylinder 300 to drive the corresponding power generation blades of the communicated pair of low-pressure cylinders 400 to rotate.

[0057] Third, when the main steam flow rate of the steam turbine system 1000 is less than the first preset main steam flow rate threshold and greater than the second preset main steam flow rate threshold, the steam load-bearing capacity of the second high-pressure cylinder 120 cannot meet the steam inlet quantity of all the main steam flow rate. However, the steam load-bearing capacity of the first high-pressure cylinder 110 can meet the steam inlet quantity of the main steam flow rate. Therefore, in order to reduce the power consumption of the steam turbine system 1000, the main steam generated by the boiler 200 can be made to flow to the first high-pressure cylinder 110 to drive the corresponding power generation blades of the first high-pressure cylinder 110 to rotate. At this time, no remaining main steam can flow into the second high-pressure cylinder 120, and the second high-pressure cylinder 120 does not need to operate. The secondary main steam flowing out of the first high-pressure cylinder 110 flows back to the boiler 200, and the boiler 200 heats the secondary main steam to generate reheated steam. The reheated steam flows to at least one intermediate-pressure cylinder 300 to drive the corresponding power generation blades of at least one intermediate-pressure cylinder 300 to rotate. The secondary reheated steam generated in each intermediate-pressure cylinder 300 respectively flows to a pair of low-pressure cylinders 400 communicated with the intermediate-pressure cylinder 300 to drive the corresponding power generation blades of the communicated pair of low-pressure cylinders 400 to rotate, thereby realizing the multi-stage conversion between thermal energy and mechanical energy.

[0058] Fourthly, when the main steam flow rate of the steam turbine system 1000 is less than the second preset main steam flow rate threshold, the steam load-bearing capacities of the first high-pressure cylinder 110 and the second high-pressure cylinder 120 can both meet the steam inlet volume of the main steam flow rate. Therefore, in order to reduce the power consumption of the steam turbine system 1000, when the second high-pressure cylinder 120 with a lower steam load-bearing capacity can meet the steam inlet volume of the main steam flow rate, there is no need for the first high-pressure cylinder 110 with a larger steam load-bearing capacity to perform steam treatment work. Therefore, the main steam generated by the boiler 200 can be directed to the second high-pressure cylinder 120 to drive the rotation of the generator blades corresponding to the second high-pressure cylinder 120. At this time, no main steam flows into the first high-pressure cylinder 110, and the first high-pressure cylinder 110 does not need to operate. The secondary main steam flowing out of the second high-pressure cylinder 120 flows back to the boiler 200, and the boiler 200 heats the secondary main steam to generate reheated steam. The reheated steam flows to at least one intermediate-pressure cylinder 300 to drive the rotation of the generator blades corresponding to at least one intermediate-pressure cylinder 300. The secondary reheated steam generated in each intermediate-pressure cylinder 300 flows to a pair of low-pressure cylinders 400 connected to the intermediate-pressure cylinder 300 respectively to drive the rotation of the generator blades corresponding to the connected pair of low-pressure cylinders 400, thereby realizing multi-stage conversion between thermal energy and mechanical energy.

[0059] For example, taking the steam load-bearing capacity of the first high-pressure cylinder 110 as 60%, the steam load-bearing capacity of the second high-pressure cylinder 120 as 40%, the first preset main steam flow rate threshold as 60% of the rated main steam flow rate, and the second preset main steam flow rate threshold as 40% of the rated main steam flow rate as an example, specifically:

[0060] When the main steam flow rate of the steam turbine is the rated main steam flow rate, all cylinders are fully open to meet the steam inlet of the steam turbine under the rated working conditions.

[0061] When the main steam flow rate of the steam turbine is between 60% and 100% of the rated main steam flow rate, the main steam preferentially enters the first high-pressure cylinder 110 with a steam load-bearing capacity of 60%, and the remaining main steam enters the second high-pressure cylinder 120 with a steam load-bearing capacity of 40%, and the minimum steam inlet volume of the second high-pressure cylinder 120 needs to be satisfied. In addition, the reheated steam will flow to at least one intermediate-pressure cylinder 300 and the low-pressure cylinder 400 connected to the flowing intermediate-pressure cylinder 300.

[0062] When the main steam flow rate of the steam turbine is between 40% and 60% of the rated main steam flow rate, the second high-pressure cylinder 120 with a steam load-bearing capacity of 40% is closed, the main steam enters the first high-pressure cylinder 110 with a steam load-bearing capacity of 60%, and the reheated steam will flow to at least one intermediate-pressure cylinder 300 and the low-pressure cylinder 400 connected to the flowing intermediate-pressure cylinder 300.

[0063] When the main steam flow rate of the steam turbine is below 40% of the rated main steam flow rate, the first high-pressure cylinder 110 with a steam load-bearing capacity of 60% is closed, the main steam enters the second high-pressure cylinder 120 with a steam load-bearing capacity of 40%, and the reheated steam will flow to at least one intermediate-pressure cylinder 300 and the low-pressure cylinder 400 connected to the flowing intermediate-pressure cylinder 300.

[0064] In the above embodiment, according to the rated main steam flow rate of the steam turbine, a first preset main steam flow rate threshold and a second preset main steam flow rate threshold are set to divide the steam treatment process of the high-pressure cylinder of the steam turbine into four cases, and accurate steam treatment can be achieved by combining the steam load-bearing capacities of each steam pressure cylinder in each case.

[0065] In an exemplary embodiment, at least one intermediate-pressure cylinder 300 includes a first intermediate-pressure cylinder and a second intermediate-pressure cylinder; at least one pair of low-pressure cylinders 400 includes a first pair of low-pressure cylinders and a second pair of low-pressure cylinders; the steam turbine system 1000 further includes:

[0066] A first high-pressure regenerative device and a second high-pressure regenerative device, the first high-pressure regenerative device is respectively connected to both the first high-pressure cylinder 110 and the second high-pressure cylinder 120, and the second high-pressure regenerative device is respectively connected to both the first high-pressure cylinder 110 and the second high-pressure cylinder 120;

[0067] A first intermediate-pressure regenerative device and a second intermediate-pressure regenerative device, the first intermediate-pressure regenerative device is respectively connected to at least one of the first intermediate-pressure cylinder and the second intermediate-pressure cylinder in the intermediate-pressure cylinder 300, and the second intermediate-pressure regenerative device is respectively connected to at least one of the first intermediate-pressure cylinder and the second intermediate-pressure cylinder in the intermediate-pressure cylinder 300;

[0068] A first low-pressure regenerative device, a second low-pressure regenerative device, a third low-pressure regenerative device and a fourth low-pressure regenerative device, the first low-pressure regenerative device, the second low-pressure regenerative device, the third low-pressure regenerative device and the fourth low-pressure regenerative device are respectively connected to at least one of the first pair of low-pressure cylinders and the second pair of low-pressure cylinders in the low-pressure cylinder 400.

[0069] Among them, the regenerative device is an important device to improve the thermal efficiency of the thermal power plant. It uses the steam extraction of the steam turbine to heat the feed water of the boiler 200, thereby increasing the feed water temperature, reducing the heat loss of the boiler 200, and improving the overall thermal efficiency of the power plant. The number of regenerative devices is equal to the number of corresponding steam pressure cylinders. For example, in the structure of the steam turbine, two high-pressure cylinders correspond to two high-pressure regenerative devices, two intermediate-pressure cylinders 300 correspond to two intermediate-pressure regenerative devices, and four low-pressure cylinders 400 should have four low-pressure regenerative devices, but their connection relationship is not one steam pressure cylinder corresponding to one regenerative device.

[0070] Specifically, when at least one intermediate-pressure cylinder 300 includes two parallel intermediate-pressure cylinders 300 and at least one pair of low-pressure cylinders 400 includes two pairs of parallel low-pressure cylinders 400, the two intermediate-pressure cylinders 300 include a first intermediate-pressure cylinder and a second intermediate-pressure cylinder, and the two pairs of low-pressure cylinders 400 include a first pair of low-pressure cylinders and a second pair of low-pressure cylinders. In practical applications, the inlet and exhaust steam designs of the two parallel intermediate-pressure cylinders 300 are independent. Their number of stages, inlet steam and exhaust steam pressures can be adjusted according to the corresponding low-pressure cylinders 400 as needed. Their structures are all intermediate steam inlet and two-end steam exhaust, arranged coaxially, with the function of self-balancing thrust. The intermediate-pressure cylinder 300 and the low-pressure cylinder 400 generally adopt a single-shaft arrangement method, and a single generator is designed. From the classification of the power generation unit, the intermediate-pressure cylinder 300 and the low-pressure cylinder 400 are one set of units. The steam load-bearing capacity of the two parallel intermediate-pressure cylinders 300 can be adjusted according to the local load rate, for example: 4:6, 5.5:4.5, etc. The steam load-bearing capacity ratios between the two high-pressure cylinders, between the two intermediate-pressure cylinders 300, and between the two pairs of low-pressure cylinders 400 are all the same.

[0071] Each steam pressure cylinder can be connected to the regenerative equipment or not. In this application, in order to improve the regenerative effect, a first high-pressure regenerative equipment and a second high-pressure regenerative equipment are provided for the two high-pressure cylinders. The first high-pressure cylinder 110 is respectively connected to the first high-pressure regenerative equipment and the second high-pressure regenerative equipment, and the second high-pressure cylinder 120 is respectively connected to the first high-pressure regenerative equipment and the second high-pressure regenerative equipment; a first intermediate-pressure regenerative equipment and a second intermediate-pressure regenerative equipment are provided for the two intermediate-pressure cylinders 300. The first intermediate-pressure regenerative equipment is respectively connected to at least one of the first intermediate-pressure cylinder and the second intermediate-pressure cylinder 300, and the second intermediate-pressure regenerative equipment is respectively connected to at least one of the first intermediate-pressure cylinder and the second intermediate-pressure cylinder 300; a first intermediate-pressure regenerative equipment and a second intermediate-pressure regenerative equipment are provided for the two pairs of low-pressure cylinders 400. The first low-pressure regenerative equipment, the second low-pressure regenerative equipment, the third low-pressure regenerative equipment, and the fourth low-pressure regenerative equipment are respectively connected to at least one of the first pair of low-pressure cylinders and the second pair of low-pressure cylinders 400.

[0072] That is to say, the intermediate-pressure regenerative equipment does not necessarily communicate with all the intermediate-pressure cylinders 300, and the low-pressure regenerative equipment does not necessarily communicate with all the low-pressure cylinders 400, so that in subsequent processing, different steam treatment measures can be adaptively taken to reduce the power consumption of the intermediate-pressure cylinder 300 and the low-pressure cylinder 400, so as to maintain the efficiency of the intermediate-pressure cylinder 300 and the low-pressure cylinder 400 in steam treatment.

[0073] In the above embodiments, by providing the first high-pressure regenerative device, the second high-pressure regenerative device, the first intermediate-pressure regenerative device, the second intermediate-pressure regenerative device, the first low-pressure regenerative device, the second low-pressure regenerative device, the third low-pressure regenerative device and the fourth low-pressure regenerative device, the efficiency of the steam turbine in performing regenerative treatment on steam can be improved, and thus the power generation efficiency of the steam turbine can be enhanced.

[0074] In an exemplary embodiment, the first intermediate-pressure regenerative device is respectively connected to both the first intermediate-pressure cylinder and the second intermediate-pressure cylinder, and the second intermediate-pressure regenerative device is respectively connected to both the first intermediate-pressure cylinder and the second intermediate-pressure cylinder;

[0075] The first pair of low-pressure cylinders are respectively connected to both the first low-pressure regenerative device and the third low-pressure regenerative device, and the second pair of low-pressure cylinders are respectively connected to both the second low-pressure regenerative device and the fourth low-pressure regenerative device and the second pair of low-pressure cylinders.

[0076] Specifically, the first intermediate-pressure cylinder is respectively connected to both the first intermediate-pressure regenerative device and the second intermediate-pressure regenerative device, and the second intermediate-pressure cylinder is respectively connected to both the first intermediate-pressure regenerative device and the second intermediate-pressure regenerative device.

[0077] The first pair of low-pressure cylinders are respectively connected to the first low-pressure regenerative device, the second low-pressure regenerative device, the third low-pressure regenerative device and the fourth low-pressure regenerative device, and the second pair of low-pressure cylinders are respectively connected to the first low-pressure regenerative device, the second low-pressure regenerative device, the third low-pressure regenerative device and the fourth low-pressure regenerative device.

[0078] That is to say, each intermediate-pressure cylinder 300 is respectively connected to all the intermediate-pressure regenerative devices, and each low-pressure cylinder 400 is respectively connected to all the low-pressure regenerative devices, so as to improve the utilization rate of steam by the regenerative devices.

[0079] In the above embodiments, by connecting each steam pressure cylinder to all the corresponding regenerative devices respectively, and each low-pressure cylinder 400 to all the low-pressure regenerative devices respectively, the utilization rate of steam by the regenerative devices can be improved.

[0080] In an exemplary embodiment, the first intermediate-pressure regenerative device is respectively connected to both the first intermediate-pressure cylinder and the second intermediate-pressure cylinder, and the second intermediate-pressure regenerative device is respectively connected to both the first intermediate-pressure cylinder and the second intermediate-pressure cylinder;

[0081] The first pair of low-pressure cylinders are respectively connected to both the first low-pressure regenerative device and the third low-pressure regenerative device, and the second pair of low-pressure cylinders are respectively connected to both the second low-pressure regenerative device and the fourth low-pressure regenerative device.

[0082] Specifically, in order to reduce the operation amount of the staff, the present application also improves the connection relationship between the steam cylinder and the regenerative equipment. Specifically, the connection relationship between the high-pressure cylinder and the high-pressure regenerative equipment remains unchanged. The first high-pressure regenerative equipment is connected to both the first high-pressure cylinder 110 and the second high-pressure cylinder 120, and the second high-pressure regenerative equipment is connected to both the first high-pressure cylinder 110 and the second high-pressure cylinder 120. The connection relationship between the intermediate-pressure cylinder 300 and the intermediate-pressure regenerative equipment also remains unchanged. The first intermediate-pressure regenerative equipment is connected to both the first intermediate-pressure cylinder and the second intermediate-pressure cylinder, and the second intermediate-pressure regenerative equipment is connected to both the first intermediate-pressure cylinder and the second intermediate-pressure cylinder. Instead, the connection relationship between the low-pressure cylinder 400 and the low-pressure regenerative equipment is improved.

[0083] In the previous connection relationship between the low-pressure cylinder 400 and the low-pressure regenerative equipment, each intermediate-pressure cylinder 300 is respectively connected to all the intermediate-pressure regenerative equipment, and each low-pressure cylinder 400 is respectively connected to all the low-pressure regenerative equipment. In the improved connection relationship, the connection relationship between the low-pressure cylinder 400 and the low-pressure regenerative equipment is simplified. That is, the first pair of low-pressure cylinders is respectively connected to both the first low-pressure regenerative equipment and the third low-pressure regenerative equipment, and the second pair of low-pressure cylinders is respectively connected to both the second low-pressure regenerative equipment and the fourth low-pressure regenerative equipment and the second pair of low-pressure cylinders.

[0084] At this time, each pair of low-pressure cylinders 400 does not need to be connected to all the low-pressure regenerative equipment, but is connected to some of the low-pressure regenerative equipment. The first low-pressure regenerative equipment and the third low-pressure regenerative equipment can extract steam from the first pair of low-pressure cylinders, and the second low-pressure regenerative equipment and the fourth low-pressure regenerative equipment can extract steam from the second pair of low-pressure cylinders, so as to use the extracted steam for regeneration treatment, and the operation amount of the power plant staff can be reduced.

[0085] For example, the multiple low-pressure regenerative equipment includes the 5th low-pressure heater 550, the 6th low-pressure heater 560, the 7th low-pressure heater 570 and the 8th low-pressure heater 580. At this time, the first pair of low-pressure cylinders can be connected to the 5th low-pressure heater 550 and the 7th low-pressure heater 570, and the second pair of low-pressure cylinders can be connected to the 6th low-pressure heater 560 and the 8th low-pressure heater 580.

[0086] In the above embodiment, by setting that the first pair of low-pressure cylinders is respectively connected to both the first low-pressure regenerative equipment and the third low-pressure regenerative equipment, and the second pair of low-pressure cylinders is respectively connected to both the second low-pressure regenerative equipment and the fourth low-pressure regenerative equipment, the connection relationship between the low-pressure cylinder 400 and the low-pressure regenerative equipment is simplified, and the operation amount of the power plant staff is reduced.

[0087] In an exemplary embodiment, the first intermediate-pressure cylinder communicates with the first intermediate-pressure cylinder, and the second intermediate-pressure cylinder communicates with the second intermediate-pressure cylinder. Among them, the steam load-bearing capacity of the first intermediate-pressure cylinder is greater than that of the second intermediate-pressure cylinder, and the steam load-bearing capacity of the first pair of low-pressure cylinders is greater than that of the second pair of low-pressure cylinders;

[0088] When the main steam flow rate of the steam turbine system 1000 is greater than the first preset main steam flow rate threshold, the reheated steam flows to the first intermediate-pressure cylinder to drive the corresponding power generation blades of the first intermediate-pressure cylinder to rotate. The secondary reheated steam generated in the first intermediate-pressure cylinder flows to the first pair of low-pressure cylinders to drive the corresponding power generation blades of the first pair of low-pressure cylinders to rotate. When the reheated steam fills the first intermediate-pressure cylinder, the remaining reheated steam flows to the second intermediate-pressure cylinder to drive the corresponding power generation blades of the second intermediate-pressure cylinder to rotate. The secondary reheated steam generated in the second intermediate-pressure cylinder flows to the second pair of low-pressure cylinders to drive the corresponding power generation blades of the second pair of low-pressure cylinders to rotate;

[0089] When the main steam flow rate of the steam turbine system 1000 is less than the first preset main steam flow rate threshold and greater than the second preset main steam flow rate threshold, the reheated steam flows to the first intermediate-pressure cylinder to drive the corresponding power generation blades of the first intermediate-pressure cylinder to rotate. The secondary reheated steam generated in the first intermediate-pressure cylinder flows to the first pair of low-pressure cylinders to drive the corresponding power generation blades of the first pair of low-pressure cylinders to rotate;

[0090] When the main steam flow rate of the steam turbine system 1000 is less than the second preset main steam flow rate threshold, the reheated steam flows to the second intermediate-pressure cylinder to drive the corresponding power generation blades of the second intermediate-pressure cylinder to rotate. The secondary reheated steam generated in the second intermediate-pressure cylinder flows to the second pair of low-pressure cylinders to drive the corresponding power generation blades of the second pair of low-pressure cylinders to rotate.

[0091] Specifically, it is set that the steam load-bearing capacity of the first intermediate-pressure cylinder is greater than that of the second intermediate-pressure cylinder, and the steam load-bearing capacity of the first pair of low-pressure cylinders is greater than that of the second pair of low-pressure cylinders. The setting process of the steam load-bearing capacity between the two intermediate-pressure cylinders 300 is similar to the setting process of the steam load-bearing capacity of the first high-pressure cylinder 110 and the second high-pressure cylinder 120. The setting process of the steam load-bearing capacity between the two pairs of low-pressure cylinders 400 is similar to the setting process of the steam load-bearing capacity of the first high-pressure cylinder 110 and the second high-pressure cylinder 120, which will not be elaborated here.

[0092] Moreover, the interaction between the reheated steam and the intermediate-pressure cylinder 300 and the low-pressure cylinder 400 is also related to the main steam flow rate of the steam turbine system 1000, specifically including the following situations:

[0093] First, when the main steam flow rate of the steam turbine system 1000 is greater than the first preset main steam flow rate threshold, the reheated steam preferentially flows to the first intermediate pressure cylinder with a larger steam load capacity to drive the generator blades corresponding to the first intermediate pressure cylinder to rotate and generate secondary reheated steam. The first intermediate pressure cylinder is connected to the first pair of low-pressure cylinders. Therefore, the secondary reheated steam flows to the first pair of low-pressure cylinders to drive the generator blades corresponding to the first pair of low-pressure cylinders to rotate. At the same time, after the first intermediate pressure cylinder is filled with reheated steam, the remaining reheated steam cannot enter the first intermediate pressure cylinder but enters the second intermediate pressure cylinder with a smaller steam load capacity to drive the generator blades corresponding to the second intermediate pressure cylinder to rotate. The second intermediate pressure cylinder is connected to the second pair of low-pressure cylinders, and the secondary reheated steam generated in the second intermediate pressure cylinder flows to the second pair of low-pressure cylinders to drive the generator blades corresponding to the second pair of low-pressure cylinders to rotate.

[0094] Second, when the main steam flow rate of the steam turbine system 1000 is less than the first preset main steam flow rate threshold and greater than the second preset main steam flow rate threshold, the steam load capacity of the single first intermediate pressure cylinder can meet the steam inlet demand of the reheated steam, while the steam load capacity of the single second intermediate pressure cylinder cannot meet the steam inlet demand of the reheated steam. Therefore, the first intermediate pressure cylinder is in the open state, the second intermediate pressure cylinder is in the closed state, the reheated steam flows to the first intermediate pressure cylinder to drive the generator blades corresponding to the first intermediate pressure cylinder to rotate, and the secondary reheated steam generated in the first intermediate pressure cylinder flows to the first pair of low-pressure cylinders corresponding to the first intermediate pressure cylinder to drive the generator blades corresponding to the first pair of low-pressure cylinders to rotate.

[0095] Third, when the main steam flow rate of the steam turbine system 1000 is less than the second preset main steam flow rate threshold, the steam load capacities of both the single first intermediate pressure cylinder and the single second intermediate pressure cylinder can meet the steam inlet demand of the reheated steam. To reduce the power consumption of the steam turbine system 1000, the first intermediate pressure cylinder can be in the closed state and the second intermediate pressure cylinder can be in the open state. The reheated steam flows to the second intermediate pressure cylinder to drive the generator blades corresponding to the second intermediate pressure cylinder to rotate, and the secondary reheated steam generated in the second intermediate pressure cylinder flows to the second pair of low-pressure cylinders corresponding to the second intermediate pressure cylinder to drive the generator blades corresponding to the second pair of low-pressure cylinders to rotate.

[0096] Taking the steam load capacity of the first intermediate pressure cylinder as 60%, the steam load capacity of the second intermediate pressure cylinder as 40%, the steam load capacity of the first pair of low-pressure cylinders as 60%, the steam load capacity of the second pair of low-pressure cylinders as 40%, the first preset main steam flow rate threshold as 60% of the rated main steam flow rate, and the second preset main steam flow rate threshold as 40% of the rated main steam flow rate as an example:

[0097] Specifically, when the main steam flow rate of the steam turbine is the rated main steam flow rate, all cylinders are fully open to meet the steam inlet of the steam turbine under the rated condition.

[0098] When the main steam flow rate of the steam turbine is between 60% and 100% of the rated main steam flow rate, the reheated steam preferentially enters the first intermediate pressure cylinder with a steam load capacity of 60%, and the remaining reheated steam enters the second intermediate pressure cylinder with a steam load capacity of 40%, and the minimum steam inlet volume of the second intermediate pressure cylinder needs to be satisfied. The secondary reheated steam generated by the first intermediate pressure cylinder will flow to the first pair of low-pressure cylinders, and the secondary reheated steam generated by the second intermediate pressure cylinder will flow to the second pair of low-pressure cylinders.

[0099] When the main steam flow rate of the steam turbine is between 40% and 60% of the rated main steam flow rate, the second intermediate pressure cylinder with a steam load capacity of 40% is closed, and the reheated steam enters the first intermediate pressure cylinder with a steam load capacity of 60%. The secondary reheated steam generated by the first intermediate pressure cylinder will flow to the first pair of low-pressure cylinders.

[0100] When the main steam flow rate of the steam turbine is below 40% of the rated main steam flow rate, the first intermediate pressure cylinder with a steam load capacity of 60% is closed, and the reheated steam enters the second intermediate pressure cylinder with a steam load capacity of 40%. The secondary reheated steam generated by the second intermediate pressure cylinder will flow to the second pair of low-pressure cylinders.

[0101] In the above embodiments, according to the rated main steam flow rate of the steam turbine, a first preset main steam flow rate threshold and a second preset main steam flow rate threshold are set to divide the steam treatment processes of the intermediate pressure cylinder 300 and the low-pressure cylinder 400 of the steam turbine into four cases. In each case, accurate steam treatment can be achieved by combining the steam load capacities of each steam pressure cylinder.

[0102] In an exemplary embodiment, the target intermediate pressure cylinder in the first intermediate pressure cylinder and the second intermediate pressure cylinder is respectively connected to both the first intermediate pressure feedwater heating device and the second intermediate pressure feedwater heating device, and the target pair of low-pressure cylinders connected to the target intermediate pressure cylinder are respectively connected to the first low-pressure feedwater heating device, the second low-pressure feedwater heating device, the third low-pressure feedwater heating device, and the fourth low-pressure feedwater heating device;

[0103] The reheated steam flows to the target intermediate pressure cylinder to drive the rotation of the generator blades corresponding to the target intermediate pressure cylinder. The secondary reheated steam generated in the target intermediate pressure cylinder flows to the target pair of low-pressure cylinders to drive the rotation of the generator blades corresponding to the first pair of low-pressure cylinders;

[0104] When the reheated steam fills the target intermediate pressure cylinder, the remaining reheated steam flows to the non-target intermediate pressure cylinder to drive the rotation of the generator blades corresponding to the non-target intermediate pressure cylinder. The secondary reheated steam generated in the non-target intermediate pressure cylinder flows to the non-target pair of low-pressure cylinders connected to the non-target intermediate pressure cylinder to drive the rotation of the generator blades corresponding to the non-target pair of low-pressure cylinders. Among them, the non-target intermediate pressure cylinder is the intermediate pressure cylinder 300 other than the target intermediate pressure cylinder, and the non-target pair of low-pressure cylinders is a pair of low-pressure cylinders other than the target pair of low-pressure cylinders 400.

[0105] Specifically, in addition to the connection relationship between the intermediate pressure cylinder 300 and the intermediate pressure regeneration device, and the low pressure cylinder 400 and the low pressure regeneration device in the above two embodiments, the connection relationship between the intermediate pressure cylinder 300 and the intermediate pressure regeneration device, and the low pressure cylinder 400 and the low pressure regeneration device can also be set as follows:

[0106] The first medium-pressure heat recovery device and the second medium-pressure heat recovery device are respectively connected to one of the two medium-pressure cylinders 300, and the first low-pressure heat recovery device, the second low-pressure heat recovery device, the third low-pressure heat recovery device and the fourth low-pressure heat recovery device are respectively connected to one of the two pairs of low-pressure cylinders 400.

[0107] Furthermore, taking the intermediate pressure cylinder 300 connected to all the intermediate pressure heat recovery equipment as an example: obtain the actual operating time of the turbine at each preset ratio of the rated main steam flow; determine the target ratio of the rated main steam flow with the longest actual operating time from the rated main steam flow of each preset ratio; determine the high pressure cylinder that matches the target ratio of the rated main steam flow from the steam load bearing capacity of the first high pressure cylinder 110 and the second high pressure cylinder 120.

[0108] For example, if the actual operating time of the steam turbine at 40% of the rated main steam flow is longer, the steam load capacity of the second intermediate pressure cylinder can be set to 40%, and the steam load capacity of the first intermediate pressure cylinder can be set to 60%. At this time, the second intermediate pressure cylinder with a steam load capacity set to 40% is used as the target intermediate pressure cylinder connected to all intermediate pressure heat recovery equipment, and the second intermediate pressure cylinder is set to be able to extract steam into the corresponding heat recovery equipment; for another example, if the actual operating time of the steam turbine at 60% of the rated main steam flow is longer, the steam load capacity of the first intermediate pressure cylinder can be set to 60%, and the steam load capacity of the second intermediate pressure cylinder can be set to 40%. At this time, the first intermediate pressure cylinder with a steam load capacity set to 60% is used as the target intermediate pressure cylinder connected to all intermediate pressure heat recovery equipment, and the first intermediate pressure cylinder is set to be able to extract steam into the corresponding heat recovery equipment.

[0109] Similarly, one of the pairs of low-pressure cylinders 400 connected to all the low-pressure heat recovery devices can also be determined according to the above method, which will not be repeated here. To be simpler, since each pair of low-pressure cylinders 400 is matched with a medium-pressure cylinder 300, the pair of low-pressure cylinders 400 corresponding to the medium-pressure cylinders 300 connected to all the medium-pressure heat recovery devices can be used as a pair of low-pressure cylinders 400 connected to all the low-pressure heat recovery devices.

[0110] In this connected state, the processing process of the reheated steam by the intermediate pressure cylinder 300 and the low pressure cylinder 400 will also change.

[0111] Specifically, the reheated steam flows to the target intermediate-pressure cylinder to drive the rotation of the generator blades corresponding to the target intermediate-pressure cylinder, without flowing to the non-target intermediate-pressure cylinder. The secondary reheated steam generated in the target intermediate-pressure cylinder flows to the target low-pressure cylinder to drive the rotation of the generator blades corresponding to the first pair of low-pressure cylinders.

[0112] When the reheated steam does not fill the target intermediate-pressure cylinder, the non-target intermediate-pressure cylinder does not need to output power, and both the non-target intermediate-pressure cylinder and the non-target pair of low-pressure cylinders connected to the non-target intermediate-pressure cylinder can be cut off. At this time, since neither the non-target intermediate-pressure cylinder nor the non-target pair of low-pressure cylinders is connected to the regenerative equipment, the cutting-off process is simpler.

[0113] When the reheated steam fills the target intermediate-pressure cylinder, the remaining reheated steam flows to the non-target intermediate-pressure cylinder. The non-target intermediate-pressure cylinder can output a small amount of power at this time to drive the rotation of the generator blades corresponding to the non-target intermediate-pressure cylinder. The secondary reheated steam generated in the non-target intermediate-pressure cylinder flows to the non-target pair of low-pressure cylinders connected to the non-target intermediate-pressure cylinder to drive the rotation of the generator blades corresponding to the non-target pair of low-pressure cylinders.

[0114] In the above embodiments, by setting the connection relationship between the intermediate-pressure cylinder 300 and the intermediate-pressure regenerative equipment such that one intermediate-pressure cylinder is connected to all the intermediate-pressure regenerative equipment and the other intermediate-pressure cylinder is not connected to any intermediate-pressure regenerative equipment, and setting the connection relationship between the low-pressure cylinder 400 and the low-pressure regenerative equipment such that one pair of low-pressure cylinders is connected to all the low-pressure regenerative equipment and the other pair of low-pressure cylinders is not connected to any low-pressure regenerative equipment, the efficiency of steam treatment can be improved.

[0115] In an exemplary embodiment, a first main steam regulating valve is provided between the first high-pressure cylinder 110 and the boiler 200, and a second main steam regulating valve is provided between the second high-pressure cylinder 120 and the boiler 200; when the first main steam regulating valve is opened, the main steam generated by the boiler 200 flows to the first high-pressure cylinder 110, and when the second main steam regulating valve is opened, the main steam generated by the boiler 200 flows to the second high-pressure cylinder 120;

[0116] A first reheated steam regulating valve is provided between the first intermediate-pressure cylinder and the boiler 200, and a second reheated steam regulating valve is provided between the second intermediate-pressure cylinder and the boiler 200; when the first reheated steam regulating valve is opened, the reheated steam generated by the boiler 200 flows to the first intermediate-pressure cylinder, and when the second reheated steam regulating valve is opened, the reheated steam generated by the boiler 200 flows to the second intermediate-pressure cylinder;

[0117] A first secondary reheated steam regulating valve is arranged between the first pair of low-pressure cylinders and the first intermediate-pressure cylinder, and a second secondary reheated steam regulating valve is arranged between the second pair of low-pressure cylinders and the second intermediate-pressure cylinder; when the first secondary reheated steam regulating valve is opened, the secondary reheated steam generated by the first intermediate-pressure cylinder flows to the first pair of low-pressure cylinders, and when the second secondary reheated steam regulating valve is opened, the secondary reheated steam generated by the second intermediate-pressure cylinder flows to the second pair of low-pressure cylinders.

[0118] Specifically, the steam regulating valve can be in a closed state or an open state. When the steam regulating valve is in the open state, steam can enter the corresponding steam pressure cylinder, and when the steam regulating valve is in the open state, steam cannot enter the corresponding steam pressure cylinder.

[0119] Therefore, in order to facilitate the efficient treatment of steam by each stage of steam pressure cylinders, a first main steam regulating valve can be arranged between the first high-pressure cylinder 110 and the boiler 200, a second main steam regulating valve can be arranged between the second high-pressure cylinder 120 and the boiler 200, a first reheated steam regulating valve can be arranged between the first intermediate-pressure cylinder and the boiler 200, a second reheated steam regulating valve can be arranged between the second intermediate-pressure cylinder and the boiler 200, a first secondary reheated steam regulating valve is arranged between the first pair of low-pressure cylinders and the first intermediate-pressure cylinder, and a second secondary reheated steam regulating valve is arranged between the second pair of low-pressure cylinders and the second intermediate-pressure cylinder.

[0120] First, open the first main steam regulating valve, and the main steam generated by the boiler 200 preferentially flows to the first high-pressure cylinder 110. When the first high-pressure cylinder 110 is filled with main steam, the second main steam regulating valve is opened, and the remaining main steam flows to the second high-pressure cylinder 120.

[0121] Secondly, since the connection methods between different intermediate-pressure cylinders 300 and the intermediate-pressure regenerative equipment are different, and the opening conditions of the intermediate-pressure cylinders 300 are also different, therefore, they will not be elaborated one by one here. Their common point is that when the reheated steam generated by the boiler 200 needs to flow to the first intermediate-pressure cylinder, the first reheated steam regulating valve needs to be opened, and when the reheated steam needs to flow to the second intermediate-pressure cylinder, the second reheated steam regulating valve needs to be opened; similarly, when the secondary reheated steam generated by the first intermediate-pressure cylinder needs to flow to the first pair of low-pressure cylinders, the first secondary reheated steam regulating valve needs to be opened, and when the secondary reheated steam generated by the second intermediate-pressure cylinder needs to flow to the second pair of low-pressure cylinders 400, the second secondary reheated steam regulating valve needs to be opened.

[0122] Furthermore, the opening and closing of each steam regulating valve are realized by the control signal of the corresponding valve output by the upper computer.

[0123] In the above embodiments, by arranging steam regulating valves at multiple communication ports, it is easier to manage and regulate the entry and exit of steam, and the reliability of the steam turbine in steam treatment is improved.

[0124] In an exemplary embodiment, both the first high-pressure regenerative device and the second high-pressure regenerative device are high-pressure heaters, the first intermediate-pressure regenerative device is a high-pressure heater, the second intermediate-pressure regenerative device is a deaerator, and the first low-pressure regenerative device, the second low-pressure regenerative device, the first low-pressure regenerative device and the second low-pressure regenerative device are all low-pressure heaters.

[0125] Specifically, the steam turbine system 1000 of the present application realizes the setting of the regenerative devices through three high-pressure heaters, four low-pressure heaters and a deaerator.

[0126] Among them, in the steam turbine system 1000, the high-pressure heater can be a high-pressure heater, and the high-pressure heater is a device that uses part of the steam extraction of the steam turbine to heat the feed water.

[0127] The low-pressure heater can be a low-pressure heater. The low-pressure heater is an important auxiliary device in the steam turbine regenerative system that extracts a certain amount of steam that has done part of the work from the steam turbine to heat the main condensate. The low-pressure heater uses the steam that has done part of the work in the steam turbine to heat the condensate, increases the temperature of the condensate, reduces the amount of steam discharged from the steam turbine to the condenser, thereby reducing energy losses and increasing the cycle efficiency of the thermal system.

[0128] The deaerator can be a deaerator, and the deaerator is a mixing heater in the regenerative system of the steam turbine generator set. It uses the intermediate steam extraction of the steam turbine to heat the feed water of the boiler 200 to the saturation temperature under the working pressure of the deaerator, thereby removing the dissolved oxygen and other non-condensable gases in the feed water, preventing or slowing down the corrosion of the boiler 200, the steam turbine and their pipelines, extending their service life, and ensuring the safe and economic operation of the power plant. The deaerator usually has a relatively high working pressure and temperature to ensure that the dissolved oxygen in the feed water can be fully removed.

[0129] Therefore, the steam turbine system 1000 collaborates with the high-pressure heater, the deaerator and the low-pressure heater to recycle and process the steam, improving the thermal efficiency and economic benefits of the unit.

[0130] In the above embodiment, by setting both the first high-pressure regenerative device and the second high-pressure regenerative device as high-pressure heaters, the first intermediate-pressure regenerative device as a high-pressure heater, the second intermediate-pressure regenerative device as a deaerator, and the first low-pressure regenerative device, the second low-pressure regenerative device, the first low-pressure regenerative device and the second low-pressure regenerative device as low-pressure heaters, reliable recycling and processing of the secondary steam generated by each stage of the steam cylinder are realized, improving the thermal efficiency and economic benefits of the unit and ensuring the safe and stable operation of the power plant.

[0131] In an exemplary embodiment, as Figure 2As shown, the first pair of low-pressure cylinders 410 includes a first low-pressure cylinder 412 and a second low-pressure cylinder 414, and the second pair of low-pressure cylinders 420 includes a third low-pressure cylinder 412 and a fourth low-pressure cylinder 414; a rotor is provided in each of the first low-pressure cylinder 412, the second low-pressure cylinder 414, the third low-pressure cylinder 412, and the fourth low-pressure cylinder 414.

[0132] The rotors of the first high-pressure cylinder 110 and the second high-pressure cylinder 120 are connected by bearings, the rotors of the second high-pressure cylinder 120 and the first intermediate-pressure cylinder 310 are connected by bearings, the rotors of the first intermediate-pressure cylinder 310 and the second intermediate-pressure cylinder 320 are connected by bearings, the rotors of the second intermediate-pressure cylinder 320 and the first low-pressure cylinder 412 are connected by bearings, the rotors of the first low-pressure cylinder 412 and the second low-pressure cylinder 414 are connected by bearings, the rotors of the second low-pressure cylinder 414 and the third low-pressure cylinder 422 are connected by bearings, and the rotors of the third low-pressure cylinder 422 and the fourth low-pressure cylinder 424 are connected by bearings.

[0133] Specifically, a steam turbine rotor is a rotating component in a steam turbine that converts the thermal energy of steam into mechanical energy. It consists of a main shaft, impellers (or drums), moving blades, couplings, and other rotating components of the steam turbine. Through the action of steam on the rotor blades, a driving force is generated to rotate the rotor, thereby outputting mechanical work.

[0134] A rotor is provided in each steam cylinder for converting the thermal energy of steam into mechanical energy, and the rotors between the steam cylinders at all levels are connected by bearings to achieve power transmission. Specifically, still as Figure 2 shown, the rotors of the first high-pressure cylinder 110 and the second high-pressure cylinder 120 are connected by bearings, the rotors of the second high-pressure cylinder 120 and the first intermediate-pressure cylinder 310 are connected by bearings, the rotors of the first intermediate-pressure cylinder 310 and the second intermediate-pressure cylinder 320 are connected by bearings, the rotors of the second intermediate-pressure cylinder 320 and the first low-pressure cylinder 412 are connected by bearings, the rotors of the first low-pressure cylinder 412 and the second low-pressure cylinder 414 are connected by bearings, the rotors of the second low-pressure cylinder 414 and the third low-pressure cylinder 422 are connected by bearings, and the rotors of the third low-pressure cylinder 422 and the fourth low-pressure cylinder 424 are connected by bearings. The bearings are Figure 2 the line segments without arrows in

[0135] the above-mentioned embodiments. By setting the rotors for energy conversion in the steam turbine and using the bearings of the rotors to achieve power transmission in the steam cylinders at all levels, the reliability of the steam turbine system 1000 for doing work is improved.

[0136] In an exemplary embodiment, the steam turbine system 1000 will be described in detail below. The steam turbine system 1000 is used to process the steam generated by the boiler 200. The steam turbine includes a first high-pressure cylinder 110, a second high-pressure cylinder 120, a first intermediate-pressure cylinder 310, a second intermediate-pressure cylinder 320, a first pair of low-pressure cylinders 410 and a second pair of low-pressure cylinders 420. Among them, the first pair of low-pressure cylinders 410 includes a first low-pressure cylinder 412 and a second low-pressure cylinder 414, and the second pair of low-pressure cylinders 420 includes a third low-pressure cylinder 422 and a fourth low-pressure cylinder 424. In addition, the steam turbine system 1000 further includes a plurality of regenerative devices, and the plurality of regenerative devices include a No. 1 high-pressure heater 510, a No. 2 high-pressure heater 520, a No. 3 high-pressure heater 530, a No. 4 deaerator 540, a No. 5 low-pressure heater 550, a No. 6 low-pressure heater 560, a No. 7 low-pressure heater 570 and a No. 8 low-pressure heater 580.

[0137] Each high-pressure cylinder is respectively connected to the boiler 200, each intermediate-pressure cylinder 300 is respectively connected to the boiler 200, the first intermediate-pressure cylinder 310 is connected to the first pair of low-pressure cylinders 410, and the second intermediate-pressure cylinder 320 is connected to the second pair of low-pressure cylinders 420.

[0138] Among them, the actual operating duration of the steam turbine under the condition of 60% of the rated main steam flow rate is the longest. Therefore, the steam load-bearing capacity of the first high-pressure cylinder 110 is set to 60%, and the steam load-bearing capacity of the second high-pressure cylinder 120 is set to 40%. Similarly, the steam load-bearing capacity of the first intermediate-pressure cylinder 310 is set to 60%, the steam load-bearing capacity of the second intermediate-pressure cylinder 320 is set to 40%, the steam load-bearing capacity of the first pair of low-pressure cylinders 410 is set to 60%, and the steam load-bearing capacity of the second pair of low-pressure cylinders 420 is set to 40%.

[0139] The first high-pressure cylinder 110 is respectively connected to both the No. 1 high-pressure heater 510 and the No. 2 high-pressure heater 520, and the second high-pressure cylinder 120 is respectively connected to both the No. 3 high-pressure heater 530 and the No. 4 high-pressure heater.

[0140] The connection relationships between the intermediate-pressure cylinder 300 and the No. 3 high-pressure heater 530, the No. 4 deaerator 540, and the low-pressure cylinder 400 and the No. 5 low-pressure heater 550, the No. 6 low-pressure heater 560, the No. 7 low-pressure heater 570 and the No. 8 low-pressure heater 580 can include the following three types:

[0141] The first type, such as Figure 3As shown, the first intermediate pressure cylinder 310 is respectively connected to the No. 3 high-pressure heater 530 and the No. 4 deaerator 540, the second intermediate pressure cylinder 320 is respectively connected to the No. 3 high-pressure heater 530 and the No. 4 deaerator 540, the first pair of low-pressure cylinders 410 are respectively connected to the No. 5 low-pressure heater 550, the No. 6 low-pressure heater 560, the No. 7 low-pressure heater 570 and the No. 8 low-pressure heater 580, and the second pair of low-pressure cylinders 420 are respectively connected to the No. 5 low-pressure heater 550, the No. 6 low-pressure heater 560, the No. 7 low-pressure heater 570 and the No. 8 low-pressure heater 580.

[0142] The second type is as Figure 4 As shown, the first intermediate pressure cylinder 310 is respectively connected to the No. 3 high-pressure heater 530 and the No. 4 deaerator 540, the second intermediate pressure cylinder 320 is respectively connected to the No. 3 high-pressure heater 530 and the No. 4 deaerator 540, the first pair of low-pressure cylinders 410 are respectively connected to the No. 5 low-pressure heater 550 and the No. 7 low-pressure heater 570, and the second pair of low-pressure cylinders 420 are respectively connected to the No. 6 low-pressure heater 560 and the No. 8 low-pressure heater 580.

[0143] The third type is as Figure 5 As shown, the first intermediate pressure cylinder 310 is respectively connected to the No. 3 high-pressure heater 530 and the No. 4 deaerator 540, the first pair of low-pressure cylinders 410 are respectively connected to the No. 5 low-pressure heater 550, the No. 6 low-pressure heater 560, the No. 7 low-pressure heater 570 and the No. 8 low-pressure heater 580, the second intermediate pressure cylinder 320 is not connected to the No. 3 high-pressure heater 530 and the No. 4 deaerator 540, and the second pair is not connected to the No. 5 low-pressure heater 550, the No. 6 low-pressure heater 560, the No. 7 low-pressure heater 570 and the No. 8 low-pressure heater 580.

[0144] For the above three connection relationships, the steam treatment processes of the corresponding steam turbine system 1000 are also different, and can be specifically divided into the following situations:

[0145] For the above first and second connection relationships, since the connection relationships between the regenerative equipment and the steam cylinders at all levels are simplified, the steam cylinders at all levels are still connected to the regenerative equipment, and the steam in each steam cylinder can still be extracted to the corresponding connected regenerative equipment. Therefore, the steam treatment process of the steam turbine system 1000 includes:

[0146] When the main steam flow rate of the steam turbine system 1000 is equal to the rated main steam flow rate, the valves corresponding to all cylinders are fully opened to meet the steam inlet of the steam turbine under the rated main steam flow rate.

[0147] When the main steam flow rate of the steam turbine system 1000 is between 60% and 100% of the rated main steam flow rate, the main steam preferentially enters the first high-pressure cylinder 110 to drive the rotation of the generator blades corresponding to the first high-pressure cylinder 110. The remaining steam enters the second high-pressure cylinder 120 to drive the rotation of the generator blades corresponding to the second high-pressure cylinder 120, while meeting the minimum steam inlet volume of the second high-pressure cylinder 120. The secondary main steam flowing out of the first high-pressure cylinder 110 and the second high-pressure cylinder 120 flows back to the boiler 200, and the boiler 200 heats the secondary main steam to generate reheated steam. The reheated steam preferentially enters the first intermediate-pressure cylinder 310 to drive the rotation of the generator blades corresponding to the first intermediate-pressure cylinder 310. The remaining steam enters the second intermediate-pressure cylinder 320 to drive the rotation of the generator blades corresponding to the second intermediate-pressure cylinder 320, while meeting the minimum steam inlet volume of the second intermediate-pressure cylinder 320. Moreover, the secondary reheated steam generated by the first intermediate-pressure cylinder 310 can also flow to the first pair of low-pressure cylinders 410 to drive the rotation of the generator blades corresponding to the first pair of low-pressure cylinders 410, and the secondary reheated steam generated by the second intermediate-pressure cylinder 320 can also flow to the second pair of low-pressure cylinders 420 to drive the rotation of the generator blades corresponding to the second pair of low-pressure cylinders 420.

[0148] When the main steam flow rate of the steam turbine system 1000 is between 40% and 60% of the rated main steam flow rate, the second high-pressure cylinder 120, the second intermediate-pressure cylinder 320, and the second pair of low-pressure cylinders 420 are closed. The main steam enters the first high-pressure cylinder 110 to drive the rotation of the generator blades corresponding to the first high-pressure cylinder 110. The secondary main steam flowing out of the first high-pressure cylinder 110 flows back to the boiler 200, and the boiler 200 heats the secondary main steam to generate reheated steam. The reheated steam enters the first intermediate-pressure cylinder 310 to drive the rotation of the generator blades corresponding to the first intermediate-pressure cylinder 310. Moreover, the secondary reheated steam generated by the first intermediate-pressure cylinder 310 can also flow to the first pair of low-pressure cylinders 410 to drive the rotation of the generator blades corresponding to the first pair of low-pressure cylinders 410.

[0149] When the main steam flow rate of the steam turbine system 1000 is below 40% of the rated main steam flow rate, the first high-pressure cylinder 110, the first intermediate-pressure cylinder 310, and the first pair of low-pressure cylinders 410 are closed. The main steam enters the second high-pressure cylinder 120 to drive the rotation of the generator blades corresponding to the second high-pressure cylinder 120. The secondary main steam flowing out of the second high-pressure cylinder 120 flows back to the boiler 200, and the boiler 200 heats the secondary main steam to generate reheated steam. The reheated steam enters the second intermediate-pressure cylinder 320 to drive the rotation of the generator blades corresponding to the second intermediate-pressure cylinder 320. Moreover, the secondary reheated steam generated by the second intermediate-pressure cylinder 320 can also flow to the second pair of low-pressure cylinders 420 to drive the rotation of the generator blades corresponding to the second pair of low-pressure cylinders 420.

[0150] For the above-mentioned third type of connection relationship, there are some steam cylinders that are not connected to the regenerative equipment. Therefore, during the steam treatment process of the steam turbine system 1000, the steam will flow to the steam cylinders with regenerative equipment, that is, to the first intermediate pressure cylinder 310 and the first pair of low-pressure cylinders 410. At this time, the first intermediate pressure cylinder 310 and the first pair of low-pressure cylinders 410 remain in operation, and the steam cylinders without regenerative equipment, such as the second intermediate pressure cylinder 320 and the second pair of low-pressure cylinders 420, will be cut off or operate with a very low output. The secondary steam generated in the steam cylinders will extract steam into the corresponding regenerative equipment.

[0151] The above method has the following specific advantages:

[0152] 1. This application improves the energy utilization rate. This application designs a wide-load high-efficiency steam turbine system 1000, which can match the steam inlet volume, improve the steam turbine efficiency, and thus improve the energy utilization rate of the steam.

[0153] 2. This application has the advantage of energy conservation. This application can improve the steam turbine efficiency, thereby reducing the coal consumption of the unit and having an energy-saving effect.

[0154] 3. This application has the advantage of carbon reduction. This application reduces the carbon consumption and carbon dioxide emissions by improving the energy utilization rate and reducing the coal consumption of the unit.

[0155] 4. This application provides technical support for the construction of a new generation of coal-fired power and a new power system.

[0156] It should be understood that although the steps in the flowcharts involved in the above embodiments are displayed in sequence according to the arrows, these steps are not necessarily executed in the order indicated by the arrows. Unless there is a clear description in this article, the execution of these steps does not have a strict order limit, and these steps can be executed in other orders. Moreover, at least a part of the steps in the flowcharts involved in the above embodiments may include multiple steps or multiple stages. These steps or stages are not necessarily executed at the same moment, but can be executed at different moments. The execution order of these steps or stages is not necessarily sequential, but can be executed alternately or in turn with at least a part of other steps or steps or stages in other steps.

[0157] In the description of this specification, the description referring to terms such as "some embodiments", "other embodiments", etc. means that the specific features, structures, materials or features described in connection with the embodiment or example are included in at least one embodiment or example of this application. In this specification, the schematic description of the above terms does not necessarily refer to the same embodiment or example.

[0158] The technical features of the above embodiments can be combined arbitrarily. For the sake of brevity of description, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, it should be considered as the scope recorded in this specification.

[0159] The above embodiments only express several implementation manners of the present application, and the description is relatively specific and detailed, but it should not be understood as a limitation to the scope of the present application. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present application, several modifications and improvements can still be made, and these all belong to the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the appended claims.

Claims

1. A steam turbine system, characterized in that, The steam turbine system includes: A first high-pressure cylinder and a second high-pressure cylinder, each high-pressure cylinder is respectively connected to a boiler, wherein the steam load-bearing capacity of the first high-pressure cylinder is greater than that of the second high-pressure cylinder; At least one intermediate-pressure cylinder, the intermediate-pressure cylinder is connected to the boiler; At least one pair of low-pressure cylinders, each pair of the low-pressure cylinders is connected to one of the intermediate-pressure cylinders; When the main steam flow rate of the steam turbine system is greater than the first preset main steam flow rate threshold, the main steam generated by the boiler flows to the first high-pressure cylinder to drive the corresponding power generation blades of the first high-pressure cylinder to rotate until the first high-pressure cylinder is filled, and the remaining main steam flows to the second high-pressure cylinder to drive the corresponding power generation blades of the second high-pressure cylinder to rotate. The secondary main steam flowing out of the first high-pressure cylinder and the second high-pressure cylinder flows back to the boiler, and the boiler heats the secondary main steam to generate reheated steam. The reheated steam flows to the at least one intermediate-pressure cylinder to drive the corresponding power generation blades of the at least one intermediate-pressure cylinder to rotate. The secondary reheated steam generated in each intermediate-pressure cylinder respectively flows to a pair of low-pressure cylinders connected to the intermediate-pressure cylinder to drive the corresponding power generation blades of the connected pair of low-pressure cylinders to rotate.

2. The system according to claim 1, wherein The system further includes: When the main steam flow rate of the steam turbine system is less than the first preset main steam flow rate threshold and greater than the second preset main steam flow rate threshold, the main steam generated by the boiler flows to the first high-pressure cylinder to drive the corresponding power generation blades of the first high-pressure cylinder to rotate. The secondary main steam flowing out of the first high-pressure cylinder flows back to the boiler, and the boiler heats the secondary main steam to generate reheated steam. The reheated steam flows to the at least one intermediate-pressure cylinder to drive the corresponding power generation blades of the at least one intermediate-pressure cylinder to rotate. The secondary reheated steam generated in each intermediate-pressure cylinder respectively flows to a pair of low-pressure cylinders connected to the intermediate-pressure cylinder to drive the corresponding power generation blades of the connected pair of low-pressure cylinders to rotate; When the main steam flow rate of the steam turbine system is less than the second preset main steam flow rate threshold, the main steam generated by the boiler flows to the second high-pressure cylinder to drive the corresponding power generation blades of the second high-pressure cylinder to rotate. The secondary main steam flowing out of the second high-pressure cylinder flows back to the boiler, and the boiler heats the secondary main steam to generate reheated steam. The reheated steam flows to the at least one intermediate-pressure cylinder to drive the corresponding power generation blades of the at least one intermediate-pressure cylinder to rotate. The secondary reheated steam generated in each intermediate-pressure cylinder respectively flows to a pair of low-pressure cylinders connected to the intermediate-pressure cylinder to drive the corresponding power generation blades of the connected pair of low-pressure cylinders to rotate.

3. The system according to claim 1, wherein The at least one intermediate-pressure cylinder includes a first intermediate-pressure cylinder and a second intermediate-pressure cylinder; the at least one pair of low-pressure cylinders includes a first pair of low-pressure cylinders and a second pair of low-pressure cylinders; the steam turbine system further includes: A first high-pressure regenerative device and a second high-pressure regenerative device, the first high-pressure regenerative device is respectively connected to both the first high-pressure cylinder and the second high-pressure cylinder, and the second high-pressure regenerative device is respectively connected to both the first high-pressure cylinder and the second high-pressure cylinder; The first intermediate-pressure regenerative device and the second intermediate-pressure regenerative device, where the first intermediate-pressure regenerative device is respectively connected to at least one of the first intermediate-pressure cylinder and the second intermediate-pressure cylinder, and the second intermediate-pressure regenerative device is respectively connected to at least one of the first intermediate-pressure cylinder and the second intermediate-pressure cylinder; The first low-pressure regenerative device, the second low-pressure regenerative device, the third low-pressure regenerative device, and the fourth low-pressure regenerative device, where the first low-pressure regenerative device, the second low-pressure regenerative device, the third low-pressure regenerative device, and the fourth low-pressure regenerative device are respectively connected to at least one of the first pair of low-pressure cylinders and the second pair of low-pressure cylinders; 4. The system according to claim 3, wherein The first intermediate-pressure regenerative device is respectively connected to both the first intermediate-pressure cylinder and the second intermediate-pressure cylinder, and the second intermediate-pressure regenerative device is respectively connected to both the first intermediate-pressure cylinder and the second intermediate-pressure cylinder; The first low-pressure regenerative device, the second low-pressure regenerative device, the third low-pressure regenerative device, and the fourth low-pressure regenerative device are respectively connected to both the first pair of low-pressure cylinders and the second pair of low-pressure cylinders; 5. The system according to claim 3, characterized in that, The first intermediate-pressure regenerative device is respectively connected to both the first intermediate-pressure cylinder and the second intermediate-pressure cylinder, and the second intermediate-pressure regenerative device is respectively connected to both the first intermediate-pressure cylinder and the second intermediate-pressure cylinder; Both the first pair of low-pressure cylinders are respectively connected to the first low-pressure regenerative device and the third low-pressure regenerative device, and both the second pair of low-pressure cylinders are respectively connected to the second low-pressure regenerative device and the fourth low-pressure regenerative device; 6. The system according to any one of claims 4-5, characterized in that The first intermediate-pressure cylinder is connected to the first intermediate-pressure cylinder, and the second intermediate-pressure cylinder is connected to the second intermediate-pressure cylinder. Among them, the steam load-bearing capacity of the first intermediate-pressure cylinder is greater than that of the second intermediate-pressure cylinder, and the steam load-bearing capacity of the first pair of low-pressure cylinders is greater than that of the second pair of low-pressure cylinders; When the main steam flow rate of the steam turbine system is greater than the first preset main steam flow rate threshold, the reheated steam flows to the first intermediate-pressure cylinder to drive the corresponding power generation blades of the first intermediate-pressure cylinder to rotate. The secondary reheated steam generated in the first intermediate-pressure cylinder flows to the first pair of low-pressure cylinders to drive the corresponding power generation blades of the first pair of low-pressure cylinders to rotate. When the reheated steam fills the first intermediate-pressure cylinder, the remaining reheated steam flows to the second intermediate-pressure cylinder to drive the corresponding power generation blades of the second intermediate-pressure cylinder to rotate. The secondary reheated steam generated in the second intermediate-pressure cylinder flows to the second pair of low-pressure cylinders to drive the corresponding power generation blades of the second pair of low-pressure cylinders to rotate; When the main steam flow rate of the steam turbine system is less than the first preset main steam flow rate threshold and greater than the second preset main steam flow rate threshold, the reheated steam flows to the first intermediate-pressure cylinder to drive the corresponding power generation blades of the first intermediate-pressure cylinder to rotate. The secondary reheated steam generated in the first intermediate-pressure cylinder flows to the first pair of low-pressure cylinders to drive the corresponding power generation blades of the first pair of low-pressure cylinders to rotate; When the main steam flow rate of the steam turbine system is less than the second preset main steam flow rate threshold, the reheated steam flows to the second intermediate pressure cylinder to drive the corresponding power generation blades of the second intermediate pressure cylinder to rotate, and the secondary reheated steam generated in the second intermediate pressure cylinder flows to the second pair of low pressure cylinders to drive the corresponding power generation blades of the second pair of low pressure cylinders to rotate.

7. The system according to claim 3, wherein The target intermediate pressure cylinder in the first intermediate pressure cylinder and the second intermediate pressure cylinder is respectively connected to the first intermediate pressure feedwater heater and the second intermediate pressure feedwater heater, and the target pair of low pressure cylinders connected to the target intermediate pressure cylinder are respectively connected to the first low pressure feedwater heater, the second low pressure feedwater heater, the third low pressure feedwater heater and the fourth low pressure feedwater heater; The reheated steam flows to the target intermediate pressure cylinder to drive the corresponding power generation blades of the target intermediate pressure cylinder to rotate, and the secondary reheated steam generated in the target intermediate pressure cylinder flows to the target pair of low pressure cylinders to drive the corresponding power generation blades of the first pair of low pressure cylinders to rotate; When the target intermediate pressure cylinder is filled with the reheated steam, the remaining reheated steam flows to the non-target intermediate pressure cylinder to drive the corresponding power generation blades of the non-target intermediate pressure cylinder to rotate, and the secondary reheated steam generated in the non-target intermediate pressure cylinder flows to the non-target pair of low pressure cylinders connected to the non-target intermediate pressure cylinder to drive the corresponding power generation blades of the non-target pair of low pressure cylinders to rotate, where the non-target intermediate pressure cylinder is the intermediate pressure cylinder except the target intermediate pressure cylinder, and the non-target pair of low pressure cylinders is a pair of low pressure cylinders except the target pair of low pressure cylinders.

8. The system according to claim 3, wherein A first main steam regulating valve is provided between the first high pressure cylinder and the boiler, and a second main steam regulating valve is provided between the second high pressure cylinder and the boiler; when the first main steam regulating valve is opened, the main steam generated by the boiler flows to the first high pressure cylinder, and when the second main steam regulating valve is opened, the main steam generated by the boiler flows to the second high pressure cylinder; A first reheated steam regulating valve is provided between the first intermediate pressure cylinder and the boiler, and a second reheated steam regulating valve is provided between the second intermediate pressure cylinder and the boiler; when the first reheated steam regulating valve is opened, the reheated steam generated by the boiler flows to the first intermediate pressure cylinder, and when the second reheated steam regulating valve is opened, the reheated steam generated by the boiler flows to the second intermediate pressure cylinder; A first secondary reheated steam regulating valve is provided between the first pair of low pressure cylinders and the first intermediate pressure cylinder, and a second secondary reheated steam regulating valve is provided between the second pair of low pressure cylinders and the second intermediate pressure cylinder; when the first secondary reheated steam regulating valve is opened, the secondary reheated steam generated in the first intermediate pressure cylinder flows to the first pair of low pressure cylinders, and when the second secondary reheated steam regulating valve is opened, the secondary reheated steam generated in the second intermediate pressure cylinder flows to the second pair of low pressure cylinders.

9. The system according to claim 3, characterized in that, The first high-pressure regenerative device and the second high-pressure regenerative device are both high-pressure heating devices, the first intermediate-pressure regenerative device is a high-pressure heating device, the second intermediate-pressure regenerative device is a deaerator, and the first low-pressure regenerative device, the second low-pressure regenerative device, the first low-pressure regenerative device and the second low-pressure regenerative device are all low-pressure heating devices.

10. The system according to claim 3, characterized in that, The first pair of low-pressure cylinders includes a first low-pressure cylinder and a second low-pressure cylinder, and the second pair of low-pressure cylinders includes a third low-pressure cylinder and a fourth low-pressure cylinder; the first low-pressure cylinder, the second low-pressure cylinder, the third low-pressure cylinder and the fourth low-pressure cylinder are all provided with rotors. The rotors of the first high-pressure cylinder and the second high-pressure cylinder are connected by bearings, the rotors of the second high-pressure cylinder and the first intermediate-pressure cylinder are connected by bearings, the rotors of the first intermediate-pressure cylinder and the second intermediate-pressure cylinder are connected by bearings, the rotors of the second intermediate-pressure cylinder and the first low-pressure cylinder are connected by bearings, the rotors of the first low-pressure cylinder and the second low-pressure cylinder are connected by bearings, the rotors of the second low-pressure cylinder and the third low-pressure cylinder are connected by bearings, and the rotors of the third low-pressure cylinder and the fourth low-pressure cylinder are connected by bearings.

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