High-efficiency steam turbine thermodynamic system

Abstract

The utility model relates to an efficient steam turbine thermodynamic system. The efficient steam turbine thermodynamic system comprises a first medium-low pressure cylinder set and a second medium-low pressure cylinder set which are connected in parallel. The first cylinder group steam admission amount of the first medium-low pressure cylinder group and the second cylinder group steam admission amount of the second medium-low pressure cylinder group are set according to a preset proportion, and the sum of the first cylinder group steam admission amount and the second cylinder group steam admission amount meets the rated working condition use requirement of the efficient steam turbine thermodynamic system; a first cylinder set steam inlet of the first medium-low pressure cylinder set is connected with a reheat steam conveying pipeline of the efficient turbine thermodynamic system through a first reheat steam conveying branch. A second cylinder group steam inlet of the second medium-low pressure cylinder group is connected with the reheat steam conveying pipeline through a second reheat steam conveying branch; a first valve is arranged on the first reheat steam conveying branch and used for adjusting a first steam inlet parameter of the first medium-low pressure cylinder set. The high-efficiency steam turbine thermodynamic system has high efficiency in wide-load operation.

Description

TECHNICAL FIELD

[0001] The utility model relates to the technical field of generator set, in particular to high -efficient steam turbine thermal system. BACKGROUND

[0002] Coal power unit power generation is a complex energy conversion process, involving the mutual transformation of multiple energy forms. Among them, the steam turbine in the high -efficient steam turbine thermal system is an important link for coal power unit to realize energy conversion, and its operation efficiency and performance directly affect the overall efficiency and performance of coal power unit. The cylinder of steam turbine can be divided into high pressure cylinder, medium pressure cylinder and low pressure cylinder according to different inlet steam parameters. In actual use, the high pressure cylinder is heated by the main steam after work, and the exhaust enters the boiler reheater and then enters the medium pressure cylinder to work, and the exhaust of the medium pressure cylinder enters the low pressure cylinder to work.

[0003] When the traditional unit is built, the target is usually multiple power generation, so the medium and low pressure cylinders of the steam turbine are usually designed with rated working condition as the design benchmark. However, with the development of new energy and the construction of new power system, coal power gradually changes to regulatory and security power supply, and large inlet steam volume ultra-supercritical unit is generally in medium and low load operation, which cannot fully exert the advantage of high efficiency at rated load. Therefore, how to improve the operation efficiency of the medium and low pressure cylinders of the steam turbine under various load conditions to improve the wide load efficiency of the whole unit is a problem to be solved for the current power generator set. UTILITY MODEL CONTENTS

[0004] Therefore, it is necessary to provide a high -efficient steam turbine thermal system for the problem that the medium and low pressure cylinders of the steam turbine cannot operate efficiently under medium and low load.

[0005] A kind of high -efficient steam turbine thermal system, the high -efficient steam turbine thermal system includes: the first medium and low pressure cylinder group and the second medium and low pressure cylinder group in parallel;

[0006] The first cylinder group steam inlet quantity of the first medium and low pressure cylinder group and the second cylinder group steam inlet quantity of the second medium and low pressure cylinder group are set according to a predetermined proportion, and the steam inlet quantity of the first cylinder group steam inlet quantity and the second cylinder group steam inlet quantity meets the rated working condition use demand of the high -efficient steam turbine thermal system;

[0007] The first cylinder group steam inlet of the first medium and low pressure cylinder group is connected with the reheated steam delivery pipeline of the high -efficient steam turbine thermal system through the first reheated steam delivery branch; the second cylinder group steam inlet of the second medium and low pressure cylinder group is connected with the reheated steam delivery pipeline through the second reheated steam delivery branch;

[0008] A first valve is arranged on the first reheated steam delivery branch for adjusting the first steam inlet parameter of the first medium and low pressure cylinder group.

[0009] In one of the embodiments, the first middle-low pressure cylinder group comprises a first middle pressure cylinder and a first low pressure cylinder group, and the second middle-low pressure cylinder group comprises a second middle pressure cylinder and a second low pressure cylinder group;

[0010] The first middle pressure exhaust port of the first middle pressure cylinder is connected with the first low pressure steam inlet of the first low pressure cylinder group through a first middle pressure exhaust pipe;

[0011] The second middle pressure exhaust port of the second middle pressure cylinder is connected with the second low pressure steam inlet of the second low pressure cylinder group through a second middle pressure exhaust pipe;

[0012] The first middle pressure steam inlet of the first middle pressure cylinder is connected with the reheat steam delivery pipe of the high efficiency steam turbine thermal system through a first reheat steam delivery branch, and the second middle pressure steam inlet of the second middle pressure cylinder is connected with the reheat steam delivery pipe through a second reheat steam delivery branch.

[0013] In one of the embodiments, the first middle pressure cylinder, the second middle pressure cylinder, the first low pressure cylinder group and the second low pressure cylinder group are arranged on the same axis.

[0014] In one of the embodiments, the high efficiency steam turbine thermal system further comprises a regenerative component for heating the low pressure exhaust steam of the first low pressure cylinder group and the second low pressure cylinder group;

[0015] The first low pressure exhaust port of the first low pressure cylinder group is connected with the regenerative component through a first low pressure exhaust pipe, and the second low pressure exhaust port of the second low pressure cylinder group is connected with the regenerative component through a second low pressure exhaust pipe.

[0016] In one of the embodiments, a second valve is arranged on the first low pressure exhaust pipe for controlling the opening and closing of the first low pressure exhaust pipe.

[0017] In one of the embodiments, the steam inlet amount of the second cylinder group is greater than the steam inlet amount of the first cylinder group.

[0018] A third valve is arranged on the second reheat steam delivery branch for adjusting the second steam inlet parameter of the second middle-low pressure cylinder group.

[0019] A fourth valve is arranged on the second low pressure exhaust pipe for controlling the opening and closing of the second low pressure exhaust pipe.

[0020] In one of the embodiments, the regenerative component comprises a first low pressure heater, a second low pressure heater, a third low pressure heater and a fourth low pressure heater.

[0021] The first low-pressure heater, the second low-pressure heater, the third low-pressure heater and the fourth low-pressure heater are connected in sequence through the feedwater channel, and the steam extraction temperature of the first low-pressure heater, the second low-pressure heater, the third low-pressure heater and the fourth low-pressure heater decreases in sequence.

[0022] In one of the embodiments, the first low-pressure exhaust port is connected with the first low-pressure heater and the second low-pressure heater through the first low-pressure exhaust pipe; the second low-pressure exhaust port is connected with the third low-pressure heater and the fourth low-pressure heater through the second low-pressure exhaust pipe.

[0023] Or,

[0024] The first low-pressure exhaust port is connected with the third low-pressure heater and the fourth low-pressure heater through the first low-pressure exhaust pipe; the second low-pressure exhaust port is connected with the first low-pressure heater and the second low-pressure heater through the second low-pressure exhaust pipe.

[0025] In one of the embodiments, the first low-pressure exhaust port is connected with the first low-pressure heater and the third low-pressure heater through the first low-pressure exhaust pipe; the second low-pressure exhaust port is connected with the second low-pressure heater and the fourth low-pressure heater through the second low-pressure exhaust pipe.

[0026] Or,

[0027] The first low-pressure exhaust port is connected with the second low-pressure heater and the fourth low-pressure heater through the first low-pressure exhaust pipe; the second low-pressure exhaust port is connected with the first low-pressure heater and the third low-pressure heater through the second low-pressure exhaust pipe.

[0028] In one of the embodiments, the second low-pressure exhaust port is connected with the first low-pressure heater and any one low-pressure heater other than the first low-pressure heater through the second low-pressure exhaust pipe.

[0029] The high-efficiency steam turbine thermal system comprises a first intermediate-low pressure cylinder group and a second intermediate-low pressure cylinder group connected in parallel, the first intermediate-low pressure cylinder group is connected with a reheated steam delivery pipeline through a first reheated steam delivery branch, and the second intermediate-low pressure cylinder group is connected with the reheated steam delivery pipeline through a second reheated steam delivery branch, wherein a first valve is arranged on the first reheated steam delivery branch, and the first admission parameter of the first intermediate-low pressure cylinder group can be adjusted by adjusting the valve opening of the first valve. Since the admission amount of the first cylinder group and the admission amount of the second cylinder group meet the rated working condition use requirements of the high-efficiency steam turbine thermal system, the valve opening of the first valve can be adjusted to a full opening degree when the high-efficiency steam turbine thermal system operates in the rated working condition, so that the first intermediate-low pressure cylinder group and the second intermediate-low pressure cylinder group can both achieve the best energy conversion efficiency. When the operating condition of the high-efficiency steam turbine thermal system starts to decline, the valve opening of the first valve can be adjusted to maintain the high energy conversion efficiency of the second intermediate-low pressure cylinder group by reducing the admission amount of the first intermediate-low pressure cylinder group, so as to improve the energy conversion efficiency of the overall intermediate-low pressure cylinder group, and further realize the wide load operation efficiency of the high-efficiency steam turbine thermal system. BRIEF DESCRIPTION OF DRAWINGS

[0030] Figure 1 It is a structural schematic diagram of the high-efficiency steam turbine thermal system in an embodiment;

[0031] Figure 2 It is a structural schematic diagram of the high-efficiency steam turbine thermal system in another embodiment;

[0032] Figure 3 It is a structural schematic diagram of the high-efficiency steam turbine thermal system in another embodiment;

[0033] Figure 4 It is a structural schematic diagram of the high-efficiency steam turbine thermal system in another embodiment;

[0034] Figure 5 It is a structural schematic diagram of the high-efficiency steam turbine thermal system in another embodiment;

[0035] Figure 6 It is a structural schematic diagram of the high-efficiency steam turbine thermal system in another embodiment.

[0036] BRIEF DESCRIPTION OF DRAWINGS

[0037] First medium-low pressure cylinder group - 101; Second medium-low pressure cylinder group - 102; Reheat steam conveying pipeline - 103; Regenerator assembly - 104; First cylinder group steam inlet - 1011; First reheat steam conveying branch - 1012; First valve - 1013; First medium pressure cylinder - 1014; First low pressure cylinder group - 1015; First medium pressure exhaust port - 1016; First low pressure steam inlet - 1017; First medium pressure exhaust pipeline - 1018; First medium pressure steam inlet - 1019; First low pressure exhaust port - 10110; First low pressure exhaust pipeline - 10111; Second valve - 10112; Second cylinder Group steam inlet - 1021; Second reheat steam conveying branch - 1022; Second intermediate pressure cylinder - 1023; Second low pressure cylinder group - 1024; Second intermediate pressure exhaust port - 1025; Second low pressure steam inlet - 1026; Second intermediate pressure exhaust pipe - 1027; Second intermediate pressure steam inlet - 1028; Second low pressure exhaust port - 1029; Second low pressure exhaust pipe - 10210; Third valve - 10211; Fourth valve - 10212; First low pressure heater - 1041; Second low pressure heater - 1042; Third low pressure heater - 1043; Fourth low pressure heater - 1044. Detailed Implementation

[0038] To make the above-mentioned objects, features, and advantages of this utility model more apparent and understandable, the specific embodiments of this utility model will be described in detail below with reference to the accompanying drawings. Many specific details are set forth in the following description to provide a full understanding of this utility model. However, this utility model can be implemented in many other ways different from those described herein, and those skilled in the art can make similar modifications without departing from the spirit of this utility model. Therefore, this utility model is not limited to the specific embodiments disclosed below.

[0039] In the description of this utility model, it should be understood that the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc., indicating the orientation or positional relationship are based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this utility model and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this utility model.

[0040] In addition, the terms "first", "second", "third", etc. are used only for descriptive purposes and do not connote or imply relative importance or an ordering between or among the indicated technical features. Thus, a feature defined with "first", "second", etc. can include at least one of the features, explicitly or implicitly. In the description of the present application, the meaning of "a plurality of" is at least two, such as two, three, etc., unless otherwise explicitly and specifically limited.

[0041] In the present application, unless otherwise explicitly specified and limited, the terms "mounting", "connecting", "connecting", "fixing" and the like should be understood in a broad sense, for example, it can be fixedly connected, or it can be detachably connected, or it can be integrated; it can be mechanically connected, or it can be electrically connected; it can be directly connected, or it can be indirectly connected through an intermediate medium; it can be the internal communication of two elements or the interaction relationship between two elements, unless otherwise explicitly limited. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0042] In the present application, unless otherwise explicitly specified and limited, the first feature is "on" or "under" the second feature. The first and second features can be in direct contact, or the first and second features can be in indirect contact through an intermediate medium. Moreover, the first feature "above", "above" and "above" the second feature can be directly above or obliquely above the first feature, or only indicate that the horizontal height of the first feature is higher than that of the second feature. The first feature "below", "below" and "below" the second feature can be directly below or obliquely below the first feature, or only indicate that the horizontal height of the first feature is less than that of the second feature.

[0043] It should be noted that when an element is referred to as "fixed to" or "provided on" another element, it can be directly on another element or there can be a middle element. When an element is considered to be "connected" to another element, it can be directly connected to another element or there can be a middle element. The terms "vertical", "horizontal", "up", "down", "left", "right" and similar expressions used herein are only for illustrative purposes and do not represent the only embodiment.

[0044] In the conventional high-efficiency steam turbine thermal system, a medium-pressure cylinder is usually arranged to connect a low-pressure cylinder to operate, and the exhaust steam of the medium-pressure cylinder is input into the low-pressure cylinder to continue to work, and all the reheated steam generated by the high-efficiency steam turbine thermal system will enter the only medium-pressure cylinder, expand and work in the medium-pressure cylinder, drive the steam turbine rotor to operate, and convert energy.

[0045] Since the conventional high-efficiency steam turbine thermal system is usually designed for multiple power generation during construction, the intermediate and low-pressure cylinders in the steam turbine are usually designed based on the rated operating condition as the design reference, that is, the intermediate and low-pressure cylinders in the conventional steam turbine can only maintain high energy conversion efficiency under the rated operating condition. Under the medium and low load operating condition, since the reheat steam parameters generated by the high-efficiency steam turbine thermal system do not match the design values corresponding to the rated operating condition, for example, the steam flow rate decreases and the steam inlet pressure decreases, which will lead to a decrease in the energy conversion efficiency of the intermediate and low-pressure cylinders, which is one of the reasons for the increase in coal consumption of the coal-fired power unit under the medium and low load operating condition.

[0046] In order to improve the operating efficiency of the intermediate and low-pressure cylinders of the steam turbine under various load operating conditions, and further improve the wide load efficiency of the entire unit, as shown in Figure 1 The high-efficiency steam turbine thermal system provided by the present application comprises: a first intermediate and low-pressure cylinder group 101 and a second intermediate and low-pressure cylinder group 102 connected in parallel.

[0047] The first cylinder group steam inlet amount of the first intermediate and low-pressure cylinder group 101 and the second cylinder group steam inlet amount of the second intermediate and low-pressure cylinder group 102 are set according to a preset ratio, and the steam inlet amounts of the first cylinder group steam inlet amount and the second cylinder group steam inlet amount satisfy the rated operating condition use requirements of the high-efficiency steam turbine thermal system.

[0048] The first cylinder group steam inlet port 1011 of the first intermediate and low-pressure cylinder group 101 is connected with the reheat steam delivery pipeline 103 of the high-efficiency steam turbine thermal system through a first reheat steam delivery branch 1012, and the second cylinder group steam inlet port 1021 of the second intermediate and low-pressure cylinder group 102 is connected with the reheat steam delivery pipeline 103 through a second reheat steam delivery branch 1022. A first valve 1013 is arranged on the first reheat steam delivery branch 1012, which is used to adjust the first steam inlet parameter of the first intermediate and low-pressure cylinder group 101.

[0049] The intermediate and low-pressure cylinder group is an energy conversion device that uses the reheat steam formed by the high-efficiency steam turbine thermal system to do work and realize energy conversion. The first intermediate and low-pressure cylinder group 101 is formed by a first intermediate pressure cylinder and a first low pressure cylinder connected in series, and the second intermediate and low-pressure cylinder group 102 is formed by a second intermediate pressure cylinder and a second low pressure cylinder connected in series.

[0050] The first cylinder group steam inlet amount of the first intermediate and low-pressure cylinder group 101 refers to the design steam inlet amount of the first intermediate and low-pressure cylinder group 101, that is, the reheat steam steam inlet amount corresponding to the first intermediate and low-pressure cylinder group 101 required when the first intermediate and low-pressure cylinder group 101 reaches the best energy conversion efficiency. The second cylinder group steam inlet amount of the second intermediate and low-pressure cylinder group 102 refers to the design steam inlet amount of the second intermediate and low-pressure cylinder group 102, that is, the reheat steam steam inlet amount corresponding to the second intermediate and low-pressure cylinder group 102 required when the second intermediate and low-pressure cylinder group 102 reaches the best energy conversion efficiency.

[0051] The sum of the steam admission amounts of the first cylinder group and the second cylinder group meets the rated operating condition use requirement of the high-efficiency steam turbine thermal system, which means that the first middle-low pressure cylinder group 101 and the second middle-low pressure cylinder group 102 can receive all the reheat steam generated by the high-efficiency steam turbine thermal system when the high-efficiency steam turbine thermal system is operating at the rated operating condition. When designing the thermal system, by making the sum of the steam admission amounts of the first cylinder group and the second cylinder group meet the rated operating condition use requirement of the high-efficiency steam turbine thermal system, the energy conversion efficiency of the high-efficiency steam turbine thermal system at the rated operating condition can be guaranteed. It can be understood that the specific design scheme of the first cylinder group and the second cylinder group can be determined according to the actual use of the high-efficiency steam turbine thermal system.

[0052] In one embodiment, the size relationship between the first cylinder group and the second cylinder group is represented by a ratio. The admission ratio of the first middle-low pressure cylinder group 101 and the second middle-low pressure cylinder group 102 can be designed according to the length of time that the coal-fired unit is operated at middle and low loads at the unit site. For example, if the unit is actually operated at a 40% load condition for a long time, the admission ratio of the first middle-low pressure cylinder group 101 and the second middle-low pressure cylinder group 102 can be set to 4:6, i.e., the first cylinder group admission amount is 40% of the total amount of reheat steam generated by the unit at the rated operating condition, and the second cylinder group admission amount is 60% of the total amount of reheat steam generated by the unit at the rated operating condition. For another example, if the unit is actually operated at a 30% load condition for a long time, the admission ratio of the first middle-low pressure cylinder group 101 and the second middle-low pressure cylinder group 102 can be set to 3:7, i.e., the first cylinder group admission amount is 30% of the total amount of reheat steam generated by the unit at the rated operating condition, and the second cylinder group admission amount is 70% of the total amount of reheat steam generated by the unit at the rated operating condition. Similarly, the admission ratio of the first cylinder group and the second cylinder group can be 1:9, 2:8, 3:7, 4:6, 5:5, etc.

[0053] The reheat steam delivery pipeline 103 is a gas delivery main pipeline for transmitting reheat steam. The steam inlet end of the reheat steam delivery pipeline 103 can be connected with a reheat steam generation source in the high-efficiency steam turbine thermal system, such as a reheater of a boiler, to receive the reheat steam generated by the reheater. The first reheat steam delivery branch 1012 is a steam delivery pipeline for transmitting reheat steam to the first intermediate-low-pressure cylinder set 101. The first cylinder set steam inlet 1011 of the first intermediate-low-pressure cylinder set 101 can be connected with the reheat steam delivery pipeline 103 through the first reheat steam delivery branch 1012, so that the reheat steam can be transmitted to the first intermediate-low-pressure cylinder set 101 for energy conversion. The second reheat steam delivery branch 1022 is a steam delivery pipeline for transmitting reheat steam to the second intermediate-low-pressure cylinder set 102. The rear second cylinder set steam inlet 1021 of the second intermediate-low-pressure cylinder set 102 can be connected with the reheat steam delivery pipeline 103 through the second reheat steam delivery branch 1022, so that the reheat steam can be transmitted to the second intermediate-low-pressure cylinder set 102 for energy conversion.

[0054] The first reheat steam delivery branch 1012 is provided with a first valve 1013 for adjusting the first steam inlet parameter of the first intermediate-low-pressure cylinder set 101. The first steam inlet parameter is parameter information for characterizing the reheat steam transmission condition of the first intermediate-low-pressure cylinder set 101, which can include the steam inlet amount and / or steam inlet pressure of the reheat steam. By providing the first valve 1013 on the first reheat steam delivery branch 1012, when the operating load of the high-efficiency steam turbine thermal system changes, the reheat steam inlet parameter of the first intermediate-low-pressure cylinder set 101 can be adjusted according to the load change condition,

[0055] Specifically, when the operating load of the high-efficiency steam turbine thermal system is the rated load, the opening of the first valve can be adjusted to be fully open, and the reheat steam enters the first intermediate-low-pressure cylinder set 101 and the second intermediate-low-pressure cylinder set 102 respectively, so that both cylinder sets can achieve the best energy conversion efficiency.

[0056] When the operating load of the high-efficiency steam turbine thermal system starts to decrease from the rated load, the opening of the first valve 1013 can be reduced according to the load decrease condition, so as to reduce the steam inlet amount of the first intermediate-low-pressure cylinder set 101 and ensure the steam inlet amount of the second intermediate-low-pressure cylinder set 102. Compared with the traditional single intermediate-low-pressure cylinder set, the energy conversion efficiency of the overall intermediate-low-pressure cylinder set can be effectively improved, and the wide-load operation efficiency of the high-efficiency steam turbine thermal system can be realized.

[0057] Taking the steam inlet amount ratio of the first cylinder set steam inlet amount to the second cylinder set steam inlet amount as 4:6 as an example, the operating conditions of the first intermediate-low-pressure cylinder set 101 and the second intermediate-low-pressure cylinder set 102 under different load conditions are described.

[0058] When the high-efficiency steam turbine thermal system is operating under rated conditions, the opening of the first valve is adjusted to be fully open, and the reheat steam enters the first medium-low pressure cylinder group 101 and the second medium-low pressure cylinder group 102 respectively. At this time, the steam intake of the first cylinder group of the first medium-low pressure cylinder 101 is 40%, and the steam intake of the second cylinder group of the second medium-low pressure cylinder group 102 is 60%. Both cylinder groups can achieve the best energy conversion efficiency.

[0059] When the operating conditions of the high-efficiency steam turbine thermal system decrease from the rated operating conditions, the opening of the first valve 1013 can be reduced according to the decrease in operating load, thereby reducing the steam intake of the first medium and low pressure cylinder group 101 and ensuring the steam intake of the second medium and low pressure cylinder group 102. When the coal-fired power unit is operating in the 100%-60% load range, the second medium and low pressure cylinder group 102 can always maintain the rated steam intake and operate with the best energy conversion efficiency. When the coal-fired power unit is operating below 60% load, the energy conversion efficiency of the second medium and low pressure cylinder group 102 will also be higher than that of the traditional medium and low pressure cylinder group.

[0060] The aforementioned high-efficiency steam turbine thermal system includes a first and a second medium-low pressure cylinder group connected in parallel. The first medium-low pressure cylinder group is connected to a reheat steam pipeline via a first reheat steam delivery branch, and the second medium-low pressure cylinder group is connected to a reheat steam pipeline via a second reheat steam delivery branch. A first valve is installed on the first reheat steam delivery branch. Adjusting the opening of the first valve regulates the first steam inlet parameters of the first medium-low pressure cylinder group. Since the steam inlet volumes of both the first and second cylinder groups meet the rated operating requirements of the high-efficiency steam turbine thermal system, when the system is operating under rated conditions, the opening of the first valve can be adjusted to full open, allowing both the first and second medium-low pressure cylinder groups to achieve optimal energy conversion efficiency. When the operating conditions of the high-efficiency steam turbine thermal system begin to decline, the valve opening of the first valve can be adjusted to reduce the steam intake of the first medium and low pressure cylinder group to maintain the high energy conversion efficiency of the second medium and low pressure cylinder group, thereby improving the overall energy conversion efficiency of the medium and low pressure cylinder group and achieving high efficiency of the high-efficiency steam turbine thermal system under wide loads.

[0061] In one embodiment, such as Figure 2 As shown, the first medium-low pressure cylinder group includes a first medium pressure cylinder 1014 and a first low pressure cylinder group 1015, and the second medium-low pressure cylinder group includes a second medium pressure cylinder 1023 and a second low pressure cylinder group 1024.

[0062] The first medium-pressure cylinder 1014 is connected with the first low-pressure cylinder group 1015 through the first medium-pressure exhaust pipe 1018. The second medium-pressure cylinder 1023 is connected with the second low-pressure cylinder group 1024 through the second medium-pressure exhaust pipe 1027.

[0063] The first medium-pressure cylinder 1014 is connected with the high-efficiency steam turbine thermal system through the first reheated steam delivery branch 1012. The second medium-pressure cylinder 1023 is connected with the high-efficiency steam turbine thermal system through the second reheated steam delivery branch 1022.

[0064] Specifically, by connecting the first medium-pressure cylinder with the first low-pressure cylinder group and connecting the second medium-pressure cylinder with the second low-pressure cylinder group, the first medium-pressure cylinder and the first low-pressure cylinder group form a first medium-low-pressure cylinder group, which is independent of the second medium-low-pressure cylinder group in terms of exhaust. The exhaust of the first medium-pressure cylinder only enters the first low-pressure cylinder group, and the exhaust of the second medium-pressure cylinder only enters the second low-pressure cylinder group. The steam between the two cylinder groups is not mixed, and the steam inlet ratio can be adjusted, thereby realizing the high efficiency of the wide load operation of the high-efficiency steam turbine thermal system.

[0065] In an embodiment, the first medium-pressure cylinder, the second medium-pressure cylinder, the first low-pressure cylinder group, and the second low-pressure cylinder group in the high-efficiency steam turbine thermal system are arranged on the same axis.

[0066] Specifically, by arranging the first medium-pressure cylinder, the second medium-pressure cylinder, the first low-pressure cylinder group, and the second low-pressure cylinder group on the same axis, the entire high-efficiency steam turbine thermal system can realize unit operation by using only a single generator, effectively reducing the complexity of unit arrangement.

[0067] In an embodiment, as shown in FIG. 1, the high-efficiency steam turbine thermal system further comprises a reheating assembly 104 for extracting low-pressure exhaust steam from the first low-pressure cylinder group 1015 and the second low-pressure cylinder group 1024 to heat the boiler feed water. Figure 3

[0068] The first low-pressure cylinder group 1015 is connected with the reheating assembly 104 through the first low-pressure exhaust pipe 10111. The second low-pressure cylinder group 1024 is connected with the reheating assembly 104 through the second low-pressure exhaust pipe 10210.

[0069] ​The regenerative component 104 can extract some of the steam that has done work from the first low-pressure cylinder group 1015 and the second low-pressure cylinder group 1024 to heat the condensate. This process is called feedwater regenerative heating, and the corresponding steam cycle is called feedwater regenerative cycle.

[0070] Specifically, in the operation of the high-efficiency steam turbine thermal system, the regenerator assembly 104 can extract some of the steam that has already done work from the first low-pressure cylinder group 1015 through the first low-pressure exhaust pipe 10111, and at the same time extract some of the steam that has already done work from the second low-pressure cylinder group 1024 through the second low-pressure exhaust pipe 10210. The extracted steam is used to heat the feedwater in the regenerator assembly 104 to increase the temperature of the feedwater entering the boiler.

[0071] In the above embodiments, by connecting the regenerative components to the first and second low-pressure cylinder groups respectively, thermal energy can be utilized more fully, cold source losses can be reduced, and the efficiency of the entire thermodynamic cycle can be improved. Furthermore, by extracting a portion of the steam from the first and second low-pressure cylinder groups for regeneration, the amount of steam entering the condenser of the high-efficiency steam turbine thermodynamic system can be reduced, lowering the condenser's heat load. This reduces steam erosion and damage to the condenser equipment, extending the service life of related equipment in the high-efficiency steam turbine thermodynamic system.

[0072] Furthermore, such as Figure 4 As shown, in one embodiment, a second valve 10112 is provided on the first low-pressure exhaust pipe 10111 to control the opening and closing of the first low-pressure exhaust pipe 10111.

[0073] Specifically, in actual use, if the operating conditions of the high-efficiency steam turbine thermal system have decreased to the point where the first medium and low-pressure cylinder group needs to be cut off to maintain the steam intake of the second medium and low-pressure cylinder group, the first medium and low-pressure cylinder group can be cut off. In order to reduce the probability of damage to the regenerator components, a second valve 10112 needs to be installed on the first low-pressure exhaust pipe 10111. When the first medium and low-pressure cylinder group needs to be cut off, the valve opening of the first valve 1013 only needs to be adjusted to the valve opening corresponding to the zero output or micro-output state, and the second valve 10112 can be closed to achieve the cylinder cutting off process and continue to maintain the energy conversion efficiency of the second medium and low-pressure cylinder group.

[0074] Taking the steam admission ratio of the first cylinder group to the second cylinder group as 4:6 as an example, in the case that the operating condition of the high-efficiency steam turbine thermal system is 60% load condition, in order to enable the second intermediate-low pressure cylinder group to maintain the optimal energy conversion efficiency, the valve opening of the first valve 1013 needs to be adjusted to the valve opening corresponding to the zero output or micro output state, and the second valve 10112 is closed, so as to realize the cylinder cutting processing of the first intermediate-low pressure cylinder group, and enable the reheated steam to all enter the second intermediate-low pressure cylinder group to do work.

[0075] In the above embodiment, by arranging the second valve on the first low pressure exhaust pipe, the opening and closing of the first low pressure exhaust pipe can be accurately controlled, the cylinder cutting processing of the first intermediate-low pressure cylinder group is realized under necessary conditions, the energy conversion efficiency of the second intermediate-low pressure cylinder group is stably maintained, and the wide load operation efficiency of the high-efficiency steam turbine thermal system is realized.

[0076] In one embodiment, as shown in Figure 5 The second cylinder group has a larger steam admission than the first cylinder group. The second reheated steam delivery branch 1022 is provided with a third valve 10211 for adjusting the second steam admission parameter of the second intermediate-low pressure cylinder group 102. The second low pressure exhaust pipe 10210 is provided with a fourth valve 10212 for controlling the opening and closing of the second low pressure exhaust pipe 10210.

[0077] Specifically, in the case that the second cylinder group has a larger steam admission than the first cylinder group, in order to further improve the overall energy conversion efficiency of the unit, the third valve 10211 can be arranged on the second reheated steam delivery branch 1022 to adjust the second steam admission parameter of the second intermediate-low pressure cylinder group 102, and the fourth valve 10212 is arranged on the second low pressure exhaust pipe 10210 to control the opening and closing of the second low pressure exhaust pipe 10210.

[0078] In actual operation, in the case that the operating condition of the high-efficiency steam turbine thermal system is reduced to the total reheated steam amount only enabling the first intermediate-low pressure cylinder group 101 to operate at the optimal energy conversion efficiency, or not enabling the first intermediate-low pressure cylinder group 101 to operate at the optimal energy conversion efficiency, the second intermediate-low pressure cylinder group 102 can be subjected to cylinder cutting processing, and all the reheated steam is delivered to the first intermediate-low pressure cylinder group 101 to do work, so as to improve the overall operation efficiency of the high-efficiency steam turbine thermal system by maintaining the energy conversion efficiency of the first intermediate-low pressure cylinder group 101 to the maximum extent.

[0079] Taking the steam admission ratio of the first cylinder group to the second cylinder group as 4:6 as an example, when the operating condition of the high-efficiency steam turbine thermal system is 60% load condition, the valve opening of the first valve 1013 can be adjusted to the valve opening corresponding to the zero output or micro output state, and the second valve 10112 is closed, so that the first intermediate-low pressure cylinder group 101 is cut off, and all the reheated steam enters the second intermediate-low pressure cylinder group 102 to do work.

[0080] During the process that the operating condition of the high-efficiency steam turbine thermal system decreases from 60% load condition to 40% load condition, it can be considered that even if all the reheated steam is input into the second intermediate-low pressure cylinder group 102 to do work, the second intermediate-low pressure cylinder group 102 cannot be operated at the best energy conversion efficiency, but the first intermediate-low pressure cylinder group cannot also accommodate all the steam. Therefore, there are two steam admission modes in this process. In the first mode, the second valve 10112 is closed, the valve opening of the first valve 1013 is adjusted to the valve opening corresponding to the zero output or micro output state, the third valve 10211 is adjusted to full opening, and the fourth valve 10212 is opened, so that the first intermediate-low pressure cylinder group 101 is cut off, all the reheated steam enters the second intermediate-low pressure cylinder group 102 to do work, and the influence of the decrease of the steam amount on the energy conversion efficiency of the second intermediate-low pressure cylinder group 102 is reduced. In the second mode, the first valve 1013 is adjusted to full opening, the second valve 10112 is opened, the third valve 10211 is adjusted according to the valve opening of the third valve 10211 determined according to the remaining steam amount, and the fourth valve 10212 is opened, so that the reheated steam enters the first intermediate pressure cylinder preferentially, the remaining steam enters the second intermediate pressure cylinder, and the rated steam admission of the first intermediate pressure cylinder is maintained.

[0081] When the operating condition of the high-efficiency steam turbine thermal system is 40% load condition and below, the valve openings of the first valve 1013 and the second valve 10112 are kept unchanged, the valve opening of the third valve 10211 is adjusted to the valve opening corresponding to the zero output or micro output state, and the fourth valve is closed, so that the second intermediate-low pressure cylinder group is cut off.

[0082] In the above embodiment, by arranging the third valve on the second reheated steam delivery branch and the fourth valve on the second low pressure exhaust pipe, the second intermediate-low pressure cylinder group can be cut off when necessary, the energy conversion efficiency of the first intermediate-low pressure cylinder group is stably maintained, and the wide load operation efficiency of the high-efficiency steam turbine thermal system is realized.

[0083] In one embodiment, the regenerative component comprises a first low-pressure heater, a second low-pressure heater, a third low-pressure heater, and a fourth low-pressure heater. The first low-pressure heater, the second low-pressure heater, the third low-pressure heater, and the fourth low-pressure heater are connected in sequence through a feedwater channel, and the steam extraction temperature of the first low-pressure heater, the second low-pressure heater, the third low-pressure heater, and the fourth low-pressure heater decreases in sequence.

[0084] Specifically, the first low-pressure heater, the second low-pressure heater, the third low-pressure heater, and the fourth low-pressure heater are connected in sequence through a feedwater channel, and the steam extraction temperature of the first low-pressure heater, the second low-pressure heater, the third low-pressure heater, and the fourth low-pressure heater decreases in sequence. Therefore, after the fourth low-pressure heater heats the condensed water, the heated feedwater can be delivered to the third low-pressure heater through the feedwater channel. The third low-pressure heater further heats the feedwater through extracted steam, and the re-heated feedwater is delivered to the second low-pressure heater through the feedwater channel. The second low-pressure heater also heats the feedwater through extracted steam, and the re-heated feedwater is delivered to the first low-pressure heater through the feedwater channel. After the first low-pressure heater heats the feedwater through extracted steam, the heated feedwater can be delivered to the deaerator of the high-efficiency steam turbine thermal system for processing.

[0085] In the above embodiment, by arranging low-pressure heaters with different extraction steam temperatures to form a multi-stage regenerative system, the cascade utilization of heat energy can be achieved, energy loss can be reduced, and the overall circulating thermal efficiency of the unit can be improved.

[0086] There are various connection modes of the low-pressure heaters and the first and second intermediate-low-pressure cylinder groups. Some possible connection modes are illustrated below through some embodiments:

[0087] In one embodiment, the first low-pressure heater, the second low-pressure heater, the third low-pressure heater, and the fourth low-pressure heater can be connected to the first and second intermediate-low-pressure cylinder groups at the same time, and in actual use, steam with corresponding temperature can be extracted from the first and second intermediate-low-pressure cylinder groups for energy utilization.

[0088] In one embodiment, the first low-pressure exhaust port is connected to the first and second low-pressure heaters through a first low-pressure exhaust pipeline. The second low-pressure exhaust port is connected to the third and fourth low-pressure heaters through a second low-pressure exhaust pipeline.

[0089] Alternatively, the first low-pressure exhaust port is connected to the third and fourth low-pressure heaters through a first low-pressure exhaust pipeline. The second low-pressure exhaust port is connected to the first and second low-pressure heaters through a second low-pressure exhaust pipeline.

[0090] Specifically, the first intermediate-low pressure cylinder group can be connected with the first and third low-pressure heaters through the first low-pressure exhaust pipe, and the second intermediate-low pressure cylinder group can be connected with the second and fourth low-pressure heaters through the second low-pressure exhaust pipe.

[0091] Alternatively, the second intermediate-low pressure cylinder group can be connected with the first and third low-pressure heaters through the first low-pressure exhaust pipe, and the first intermediate-low pressure cylinder group can be connected with the second and fourth low-pressure heaters through the second low-pressure exhaust pipe.

[0092] Both of the above two connection modes are to connect a cylinder group with two low-pressure heaters in sequence, which can ensure the continuity of the steam temperature extracted from the low-pressure cylinder group.

[0093] In an embodiment, the first low-pressure exhaust port is connected with the first and third low-pressure heaters through the first low-pressure exhaust pipe, and the second low-pressure exhaust port is connected with the second and fourth low-pressure heaters through the second low-pressure exhaust pipe.

[0094] Alternatively, the first low-pressure exhaust port is connected with the second and fourth low-pressure heaters through the first low-pressure exhaust pipe, and the second low-pressure exhaust port is connected with the first and third low-pressure heaters through the second low-pressure exhaust pipe.

[0095] Specifically, the first intermediate-low pressure cylinder group can be connected with the first and third low-pressure heaters through the first low-pressure exhaust pipe, and the second intermediate-low pressure cylinder group can be connected with the second and fourth low-pressure heaters through the second low-pressure exhaust pipe. Alternatively, the second intermediate-low pressure cylinder group can be connected with the first and third low-pressure heaters through the first low-pressure exhaust pipe, and the first intermediate-low pressure cylinder group can be connected with the second and fourth low-pressure heaters through the second low-pressure exhaust pipe.

[0096] Both of the above two connection modes are to connect a cylinder group with two low-pressure heaters in sequence, which can ensure the continuity of the steam temperature extracted from the low-pressure cylinder group.

[0097] In an embodiment, the second low-pressure exhaust port is connected with the first low-pressure heater, and any one low-pressure heater other than the first low-pressure heater through the second low-pressure exhaust pipe.

[0098] Specifically, in actual operation, the probability of cylinder cutoff in the first medium-low pressure cylinder group is greater than that in the second medium-low pressure cylinder group. When the first medium-low pressure cylinder group is cut off, the first low-pressure exhaust pipe will also be cut off. Therefore, in order to improve the utilization rate of steam exhaust, the second medium-low pressure cylinder group, which has a lower probability of being cut off, is connected to the first low-pressure heater through the second low-pressure exhaust pipe. This can improve the utilization rate of the first low-pressure heater in actual operation, extract higher temperature steam to heat the feedwater, effectively improve energy utilization, and thus improve the overall operating efficiency of the high-efficiency steam turbine thermal system.

[0099] In one embodiment, such as Figure 6 As shown, a high-efficiency steam turbine thermal system 600 is provided, including a first intermediate-pressure cylinder 1014, a first low-pressure cylinder group 1015, a second intermediate-pressure cylinder 1023, a second low-pressure cylinder group 1024, a reheat steam conveying pipeline 103, a first low-pressure heater 1041, a second low-pressure heater 1042, a third low-pressure heater 1043, and a fourth low-pressure heater 1044.

[0100] The ratio of the steam intake of the first cylinder group to the steam intake of the second cylinder group is 4:6. The steam intake of the first cylinder group and the steam intake of the second cylinder group meet the rated operating conditions of the high-efficiency steam turbine thermal system.

[0101] Specifically, the first intermediate-pressure exhaust port 1016 of the first intermediate-pressure cylinder 1014 and the first low-pressure inlet port 1017 of the first low-pressure cylinder group 1015 are connected via a first intermediate-pressure exhaust pipe 1018. The second intermediate-pressure exhaust port 1025 of the second intermediate-pressure cylinder 1023 and the second low-pressure inlet port 1026 of the second low-pressure cylinder group 1024 are connected via a second intermediate-pressure exhaust pipe 1027. The first intermediate-pressure inlet port 1019 of the first intermediate-pressure cylinder 1014 is connected via a first reheat steam transmission branch 1012 to a reheat steam transmission pipe 103 of the high-efficiency steam turbine thermal system; the second intermediate-pressure inlet port 1028 of the second intermediate-pressure cylinder 1023 is connected via a second reheat steam transmission branch 1022 to a reheat steam transmission pipe 103.

[0102] A first valve 1013 is installed on the first reheat steam transmission branch 1012 to adjust the first steam inlet parameters of the first medium-low pressure cylinder group. A third valve 10211 is installed on the second reheat steam transmission branch 1022 to adjust the second steam inlet parameters of the second medium-low pressure cylinder group.

[0103] The first low-pressure cylinder group 1015 is connected with the second low-pressure heater 1042 and the fourth low-pressure heater 1044 through the first low-pressure exhaust pipe 10111, and the second low-pressure cylinder group 1024 is connected with the first low-pressure heater 1041 and the third low-pressure heater 1043 through the second low-pressure exhaust pipe 10210. The second valve 10112 is arranged on the first low-pressure exhaust pipe 10111, and is used for controlling the opening and closing of the first low-pressure exhaust pipe 10111. The fourth valve 10212 is arranged on the second low-pressure exhaust pipe 10210, and is used for controlling the opening and closing of the second low-pressure exhaust pipe 10210.

[0104] Specifically, when the high-efficiency steam turbine thermal system is operated in the rated working condition, the first valve 1013 and the third valve 10211 are adjusted to the fully open state, and at this time, the first intermediate-pressure cylinder 1014 and the second intermediate-pressure cylinder 1023 are all supplied with steam, and the optimal energy conversion efficiency is met.

[0105] When the working condition of the high-efficiency steam turbine thermal system starts to decrease from the rated working condition, the valve opening degree of the first valve 1013 is reduced, the reheat steam flow and pressure entering the first intermediate-pressure cylinder 1014 are reduced, and at the same time, the steam amount and pressure entering the second intermediate-pressure cylinder 1023 are maintained in the state consistent with the rated working condition, until the working condition decreases from 100% load to 60% load.

[0106] In the case of decreasing to 60% load, the valve opening degree of the first valve 1013 is adjusted to the valve opening degree corresponding to the zero output or micro output state, i.e., the safety valve opening degree, and at the same time, the second valve 10112 is closed, so that the first intermediate-pressure cylinder 1014 is maintained in the zero output or micro output state, and the reheat steam enters the second intermediate-pressure cylinder 1023, until the unit load decreases from 60% load to 40% load.

[0107] When the working condition of the high-efficiency steam turbine thermal system decreases to 40% load, the valve opening degree of the first valve 1013 is adjusted to the fully open degree, and at the same time, the second valve 10112 is opened. The valve opening degree of the third valve 10211 is adjusted to the valve opening degree corresponding to the zero output or micro output state, i.e., the safety valve opening degree, and at the same time, the fourth valve 10212 is closed, so that the second intermediate-pressure cylinder 1023 is maintained in the zero output or micro output state, and the reheat steam enters the first intermediate-pressure cylinder 1014.

[0108] When the working condition of the high-efficiency steam turbine thermal system starts to decrease from 40% load, the second intermediate-pressure cylinder 1023 can be maintained in the zero output or micro output state, and at the same time, the valve opening degree of the first valve 1013 is reduced, so as to reduce the steam amount and pressure entering the first intermediate-pressure cylinder 1014.

[0109] In the above embodiment, the high-efficiency steam turbine thermal system can improve the energy conversion efficiency of the medium-low pressure cylinder group under medium-low load conditions, reduce the coal consumption of the unit, and realize the wide-load high efficiency of the coal-fired unit by setting the grouped medium-low pressure steam turbine system.

[0110] The technical features of the above embodiments can be combined arbitrarily, and to make the description simple, all possible combinations of the technical features in the above embodiments are not described, however, as long as the combinations of the technical features do not exist contradictory, it should be considered that it is within the scope of the description.

[0111] The above embodiments only express several implementation manners of the utility model, the description is more specific and detailed, but it cannot be understood as the limitation of the utility model patent scope. It should be pointed out that for ordinary skilled in the art, without departing from the concept of the utility model, a number of modifications and improvements can be made, which all belong to the protection scope of the utility model. Therefore, the protection scope of the utility model patent should be subject to the appended claims.

Claims

1. A high efficiency steam turbine thermodynamic system characterized by, The high-efficiency steam turbine thermal system comprises: a first middle-low pressure cylinder group and a second middle-low pressure cylinder group connected in parallel; A first cylinder group steam admission amount of the first middle-low pressure cylinder group and a second cylinder group steam admission amount of the second middle-low pressure cylinder group are set according to a preset ratio, and the first cylinder group steam admission amount and the second cylinder group steam admission amount satisfy the rated working condition use requirement of the high-efficiency steam turbine thermal system; A first cylinder group steam inlet of the first middle-low pressure cylinder group is connected with a reheated steam delivery pipeline of the high-efficiency steam turbine thermal system through a first reheated steam delivery branch; and a second cylinder group steam inlet of the second middle-low pressure cylinder group is connected with the reheated steam delivery pipeline through a second reheated steam delivery branch; A first valve is arranged on the first reheated steam delivery branch, and is used for adjusting a first steam admission parameter of the first middle-low pressure cylinder group.

2. The high-efficiency steam turbine thermodynamic system of claim 1, wherein, The first middle-low pressure cylinder group comprises a first middle pressure cylinder and a first low pressure cylinder group, and the second middle-low pressure cylinder group comprises a second middle pressure cylinder and a second low pressure cylinder group; A first middle pressure steam outlet of the first middle pressure cylinder is connected with a first low pressure steam inlet of the first low pressure cylinder group through a first middle pressure steam delivery pipeline; A second middle pressure steam outlet of the second middle pressure cylinder is connected with a second low pressure steam inlet of the second low pressure cylinder group through a second middle pressure steam delivery pipeline; A first middle pressure steam inlet of the first middle pressure cylinder is connected with the reheated steam delivery pipeline of the high-efficiency steam turbine thermal system through the first reheated steam delivery branch; and a second middle pressure steam inlet of the second middle pressure cylinder is connected with the reheated steam delivery pipeline through the second reheated steam delivery branch.

3. The high-efficiency steam turbine thermodynamic system of claim 2, wherein, The first middle pressure cylinder, the second middle pressure cylinder, the first low pressure cylinder group and the second low pressure cylinder group are arranged on the same axis.

4. The high-efficiency steam turbine thermodynamic system of claim 2, wherein, The high-efficiency steam turbine thermal system further comprises: a regenerative component, which is used for extracting low pressure exhaust steam from the first low pressure cylinder group and the second low pressure cylinder group to heat boiler feed water; A first low pressure steam outlet of the first low pressure cylinder group is connected with the regenerative component through a first low pressure steam delivery pipeline; and a second low pressure steam outlet of the second low pressure cylinder group is connected with the regenerative component through a second low pressure steam delivery pipeline.

5. The high-efficiency steam turbine thermodynamic system of claim 4, wherein, A second valve is arranged on the first low pressure steam delivery pipeline, and is used for controlling on-off of the first low pressure steam delivery pipeline.

6. The high-efficiency steam turbine thermodynamic system of claim 5, wherein, The second cylinder group steam admission amount is greater than the first cylinder group steam admission amount; A third valve is arranged on the second reheated steam delivery branch, and is used for adjusting a second steam admission parameter of the second middle-low pressure cylinder group; A fourth valve is arranged on the second low pressure steam delivery pipeline, and is used for controlling on-off of the second low pressure steam delivery pipeline.

7. The high-efficiency steam turbine thermodynamic system of claim 5 or 6, wherein, The regenerative component comprises a first low pressure heater, a second low pressure heater, a third low pressure heater and a fourth low pressure heater; The first low pressure heater, the second low pressure heater, the third low pressure heater and the fourth low pressure heater are connected in sequence through a feed water channel, and steam extraction temperatures of the first low pressure heater, the second low pressure heater, the third low pressure heater and the fourth low pressure heater decrease in sequence.

8. The high-efficiency steam turbine thermodynamic system of claim 7, wherein, The first low-pressure exhaust port is connected with the first low-pressure heater and the second low-pressure heater through the first low-pressure exhaust pipeline; the second low-pressure exhaust port is connected with the third low-pressure heater and the fourth low-pressure heater through the second low-pressure exhaust pipeline; Or, The first low-pressure exhaust port is connected with the third low-pressure heater and the fourth low-pressure heater through the first low-pressure exhaust pipeline; the second low-pressure exhaust port is connected with the first low-pressure heater and the second low-pressure heater through the second low-pressure exhaust pipeline.

9. The high-efficiency steam turbine thermodynamic system of claim 7, wherein, The first low-pressure exhaust port is connected with the first low-pressure heater and the third low-pressure heater through the first low-pressure exhaust pipeline; the second low-pressure exhaust port is connected with the second low-pressure heater and the fourth low-pressure heater through the second low-pressure exhaust pipeline; Or, The first low-pressure exhaust port is connected with the second low-pressure heater and the fourth low-pressure heater through the first low-pressure exhaust pipeline; the second low-pressure exhaust port is connected with the first low-pressure heater and the third low-pressure heater through the second low-pressure exhaust pipeline.

10. The high-efficiency steam turbine thermodynamic system of claim 7, wherein, The second low-pressure exhaust port is connected with the first low-pressure heater and any one low-pressure heater except the first low-pressure heater through the second low-pressure exhaust pipeline.

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