Steam turbine heat supply system

Abstract

The utility model discloses a steam turbine heat supply system, and relates to the technical field of heat supply of thermal power generator sets. The steam turbine heat supply system comprises an intermediate-pressure cylinder, a low-pressure cylinder, a first low-pressure heater, a first steam extraction pipeline, a second low-pressure heater, a second steam extraction pipeline and a connection pipeline, the intermediate-pressure cylinder is provided with a first steam extraction opening, the low-pressure cylinder is provided with a second steam extraction opening, and the first steam extraction pipeline communicates with the first steam extraction opening and the first low-pressure heater; the second steam extraction pipeline communicates with the second steam extraction opening and the second low-pressure heater, and the connection pipeline communicates with the first steam extraction pipeline and the second steam extraction pipeline. The connecting pipeline is additionally arranged between the first steam extraction pipeline and the second steam extraction pipeline, so that the capacity of a heat supply network is increased, the steam flow and pressure of the first low-pressure heater and the first steam extraction pipeline are shared at the same time, and overload operation of the first low-pressure heater and the first steam extraction pipeline during cylinder switching operation is avoided; the beneficial effects that the economical efficiency of the steam turbine unit is improved, and safe operation of the unit is guaranteed are achieved.

Description

Technical Field

[0001] The utility model relates to the technical field of heat supply of thermal power generating units, and particularly relates to a steam turbine heat supply system. Background Technique

[0002] With the increasing demand for urban heat supply, nowadays, thermal power generating units basically adopt the hybrid function form of combined heat and power generation. In order to improve the operation flexibility of the units, increase the peak shaving capacity of the units, and realize the cascade utilization of energy, many thermal power plants have carried out the transformation of cutting off the low-pressure cylinder. Among them, the cutting-off cylinder transformation means that during the peak shaving period, all the steam inlets of the low-pressure cylinder are cut off for heat supply, and only a small amount of steam is introduced into the low-pressure cylinder for cooling, so as to realize the zero output operation of the low-pressure cylinder and increase the peak shaving capacity of the unit.

[0003] Under the steam turbine cutting-off cylinder heat supply condition, since some low-pressure heaters of the low-pressure cylinder are cut off, the extraction steam volume of the last-stage low-pressure heater of the intermediate-pressure cylinder increases. Especially when the heat network capacity is small and the heating flow rate of the heating network is low at the beginning and end of the heating period, after cutting off the cylinder, the extraction steam pressure and temperature of the last-stage extraction of the intermediate-pressure cylinder are high, which is easy to cause the overloaded operation of the last-stage low-pressure heater of the intermediate-pressure cylinder and the extraction steam pipeline, posing risks to the unit. Content of the Utility Model

[0004] The main purpose of the utility model is to propose a steam turbine heat supply system, aiming to solve the problem that there is a risk of overloaded operation of the last-stage low-pressure heater of the intermediate-pressure cylinder and the extraction steam pipeline after cutting off the cylinder when the heat network capacity is small and the heating flow rate of the heating network is low at the beginning and end of the heating period.

[0005] To achieve the above purpose, the utility model proposes a steam turbine heat supply system. The steam turbine heat supply system includes an intermediate-pressure cylinder, a low-pressure cylinder, a first low-pressure heater, a first extraction steam pipeline, a second low-pressure heater, a second extraction steam pipeline, and a connecting pipeline. The intermediate-pressure cylinder has a first extraction steam port, and the low-pressure cylinder has a second extraction steam port;

[0006] The low-pressure cylinder is located downstream of the intermediate-pressure cylinder. The first extraction steam pipeline connects the first extraction steam port and the first low-pressure heater. The second extraction steam pipeline connects the second extraction steam port and the second low-pressure heater. The connecting pipeline connects the first extraction steam pipeline and the second extraction steam pipeline.

[0007] In an embodiment, a connecting electric valve and a connecting check valve are sequentially arranged on the connecting pipeline along the direction from the first extraction steam pipeline to the second extraction steam pipeline.

[0008] In an embodiment, the steam turbine heat supply system further includes a first extraction steam bypass, and the first extraction steam bypass connects the first extraction steam port and the middle part of the first extraction steam pipeline.

[0009] In one embodiment, a first electric valve is provided on the first extraction bypass.

[0010] In one embodiment, the steam turbine heating system further includes a heating pipeline. The upstream of the heating pipeline is connected to the first extraction port, and the downstream of the heating pipeline is connected to low-pressure industrial users and extraction steam users for heating.

[0011] In one embodiment, a check valve for extraction steam for heating, a regulating valve for extraction steam for heating, and an electric valve for extraction steam for heating are sequentially provided on the heating pipeline along the direction from the intermediate-pressure cylinder to the extraction steam users for heating.

[0012] In one embodiment, the steam turbine heating system further includes a low-pressure cylinder exhaust pipeline and a condenser. The low-pressure cylinder further has an exhaust port, and the low-pressure cylinder exhaust pipeline connects the exhaust port and the condenser.

[0013] In one embodiment, the steam turbine heating system further includes a third extraction pipeline, a third low-pressure heater, a fourth extraction pipeline, and a fourth low-pressure heater. The low-pressure cylinder further has a third extraction port and a fourth extraction port;

[0014] The third extraction pipeline connects the third extraction port and the third low-pressure heater, and the fourth extraction pipeline connects the fourth extraction port and the fourth low-pressure heater.

[0015] In one embodiment, the third low-pressure heater and the fourth low-pressure heater are installed in the condenser. The steam turbine heating system further includes a liquid pipeline, which sequentially connects the condenser, the fourth low-pressure heater, the third low-pressure heater, the second low-pressure heater, the first low-pressure heater, and extends out of the first low-pressure heater.

[0016] In one embodiment, a second electric valve and a first check valve are sequentially arranged on the first extraction pipeline along the direction from the intermediate-pressure cylinder to the first low-pressure heater;

[0017] And / or, a second check valve and a third electric valve are sequentially arranged on the second extraction pipeline along the direction from the low-pressure cylinder to the second low-pressure heater.

[0018] The technical solution of the present utility model increases the heat network capacity by arranging a connection pipeline between the last extraction pipeline of the medium-pressure cylinder and the first extraction pipeline of the low-pressure cylinder, that is, adding a connection pipeline between the first extraction pipeline and the second extraction pipeline. When the cylinder cutting operation is realized, the second low-pressure heater connected to the low-pressure cylinder is put into operation. The extraction steam in the first extraction pipeline can heat the condensate water of the second low-pressure heater through the connection pipeline, comprehensively utilizing the extraction steam flow of the first extraction pipeline. At the same time, it shares the steam flow and pressure of the first low-pressure heater and the first extraction pipeline, avoiding overloading operation of the first low-pressure heater and the first extraction pipeline, achieving the beneficial effects of improving the economy of the steam turbine unit and ensuring the safe operation of the unit. Brief Description of the Drawings

[0019] In order to more clearly illustrate the technical solutions in the embodiments of the present utility model or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the drawings in the following description are only some embodiments of the present utility model. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on the structures shown in these drawings.

[0020] Figure 1 It is a schematic structural diagram of an embodiment of the steam turbine heating system provided by the present utility model.

[0021] Explanation of the reference numerals in the drawings:

[0022] 100, steam turbine heating system; 1, medium-pressure cylinder; 2, low-pressure cylinder; 3, first extraction pipeline; 3a, second electric valve; 3b, first check valve; 4, first low-pressure heater; 5, second extraction pipeline; 5a, third electric valve; 5b, second check valve; 6, second low-pressure heater; 7, connection pipeline; 7a, connection electric valve; 7b, connection check valve; 8, first extraction bypass; 8a, first electric valve; 9, heating supply pipeline; 9a, heating extraction check valve; 9b, heating extraction regulating valve; 9c, heating extraction electric valve; 10, low-pressure cylinder exhaust pipeline; 11, condenser; 12, third extraction pipeline; 13, third low-pressure heater; 14, fourth extraction pipeline; 15, fourth low-pressure heater; 16, heating extraction user; 17, low-pressure industrial user.

[0023] The realization of the object, functional characteristics and advantages of the present utility model will be further described in conjunction with the embodiments and with reference to the drawings. Detailed Embodiment

[0024] Next, the technical solutions in the embodiments of the present utility model will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present utility model. Obviously, the described embodiments are only a part of the embodiments of the present utility model, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present utility model without creative efforts belong to the scope of protection of the present utility model.

[0025] It should be noted that if there are directional indications (such as up, down, left, right, front, back...) involved in the embodiments of the present utility model, the directional indications are only used to explain the relative positional relationship and movement conditions between components in a specific posture. If the specific posture changes, the directional indications will also change accordingly.

[0026] In addition, if there are descriptions involving "first", "second", etc. in the embodiments of the present utility model, the descriptions of "first", "second", etc. are only for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include at least one such feature. In addition, if "and / or" or "and / or" appears throughout the text, its meaning includes three parallel solutions. Taking "A and / or B" as an example, it includes solution A, solution B, or the solution where A and B are satisfied simultaneously. In addition, the technical solutions between the various embodiments can be combined with each other, but it must be based on the ability of those of ordinary skill in the art to implement. When the combination of technical solutions results in contradictions or cannot be implemented, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection required by the present utility model.

[0027] Under the steam turbine cylinder-cutting heat supply condition, when the heat network capacity is small and the heating flow rate is low at the beginning and end of the heating period, after the cylinder is cut, the extraction steam pressure and temperature of the last stage of the intermediate pressure cylinder are high, which is likely to cause overloading of the last stage low-pressure heater of the intermediate pressure cylinder and the extraction steam pipeline, posing risks to the unit.

[0028] The present utility model proposes a steam turbine heat supply system 100.

[0029] Please refer to Figure 1, in an embodiment of the present utility model, the steam turbine heating system 100 includes an intermediate pressure cylinder 1, a low pressure cylinder 2, a first low pressure heater 4, a first extraction steam pipeline 3, a second low pressure heater 6, a second extraction steam pipeline 5, and a connection pipeline 7. The intermediate pressure cylinder 1 has a first extraction steam port, the low pressure cylinder 2 has a second extraction steam port, the low pressure cylinder 2 is located downstream of the intermediate pressure cylinder 1, the first extraction steam pipeline 3 connects the first extraction steam port and the first low pressure heater 4, the second extraction steam pipeline 5 connects the second extraction steam port and the second low pressure heater 6, and the connection pipeline 7 connects the first extraction steam pipeline 3 and the second extraction steam pipeline 5.

[0030] In the technical solution of the present utility model, the low pressure cylinder 2 is located downstream of the intermediate pressure cylinder 1. There is a connection pipeline between the steam outlet of the intermediate pressure cylinder 1 and the steam inlet of the low pressure cylinder 2, and a flow regulating valve is provided on the connection pipeline to regulate the flow rate of the steam entering the low pressure cylinder 2 from the connection pipeline. A first extraction steam pipeline 3 is provided between the intermediate pressure cylinder 1 and the first low pressure heater 4, and the first extraction steam pipeline 3 is used to guide the last stage heat network extraction steam of the intermediate pressure cylinder 1 to the first low pressure heater 4. A second extraction steam pipeline 5 is provided between the low pressure cylinder 2 and the second low pressure heater 6, and the second extraction steam pipeline 5 is used to guide the first stage heat network extraction steam of the low pressure cylinder 2 to the second low pressure heater 6. A connection pipeline 7 is additionally provided between the first extraction steam pipeline 3 and the second extraction steam pipeline 5, so that the last stage extraction steam of the intermediate pressure cylinder 1 in the first extraction steam pipeline 3 can be diverted to the second extraction pipeline and enter the second low pressure heater 6. A drain pipeline is also connected between the second low pressure heater 6 and the first low pressure heater 4. After the condensate water of the second low pressure heater 6 enters the first low pressure heater 4 through the drain pipeline, it continues to flow downstream to equipment such as high pressure heaters and deaerators and then returns to the boiler to complete a cycle.

[0031] Specifically, under the steam turbine cylinder-cutting heating condition, by controlling the flow regulating valve on the connection pipeline, all the steam entering the low pressure cylinder 2 is cut off for heating, and only a small amount of steam is introduced into the low pressure cylinder 2 for cooling, realizing the zero output operation of the low pressure cylinder 2. The second extraction steam pipeline 5 no longer conveys heat network extraction steam to the second low pressure heater 6, and the extraction steam volume of the last stage of the intermediate pressure cylinder 1 increases. In addition to being conveyed to the first low pressure heater 4 through the first extraction steam pipeline 3, the last stage extraction steam of the intermediate pressure cylinder 1 is also conveyed to the second low pressure heater 6 through the connection pipeline 7 and a part of the second extraction steam pipeline 5 to heat the condensate water in the second low pressure heater 6. The condensate water of the second low pressure heater 6 flows to the first low pressure heater 4 through the drain pipeline, and the first low pressure heater 4 is used to further increase the temperature of the condensate water, so that the condensate water is heated multiple times before returning to the boiler, reducing the energy consumption of the boiler.

[0032] The technical solution of this embodiment increases the heat network capacity by arranging a connecting pipeline 7 between the last extraction pipeline of the medium-pressure cylinder 1 and the first extraction pipeline of the low-pressure cylinder 2, that is, adding a connecting pipeline 7 between the first extraction pipeline 3 and the second extraction pipeline 5. When the cylinder cutting operation is realized, the second low-pressure heater 6 connected to the low-pressure cylinder 2 is put into operation. The extraction steam in the first extraction pipeline 3 can heat the condensate water of the second low-pressure heater 6 through the connecting pipeline 7, comprehensively utilizing the extraction steam flow of the first extraction pipeline 3. At the same time, it shares the steam flow and pressure of the first low-pressure heater 4 and the first extraction pipeline 3, avoiding overloading of the first low-pressure heater 4 and the first extraction pipeline, achieving the beneficial effects of improving the economy of the steam turbine unit and ensuring the safe operation of the unit.

[0033] To enhance the controllability and safety of the connecting pipeline 7, please refer to Figure 1 , in an embodiment of the present invention, a connecting electric valve 7a and a connecting check valve 7b are sequentially arranged on the connecting pipeline 7 along the direction from the first extraction pipeline 3 to the second extraction pipeline 5. During the non-cylinder-cutting operation period, the low-pressure cylinder 2 is put into use, and the heat network extraction steam flows in both the first extraction pipeline 3 and the second extraction pipeline 5. The flow and pressure of the first extraction pipeline 3 are small, and the connecting electric valve 7a can be remotely closed to deactivate the connecting pipeline 7, which is convenient and fast.

[0034] Furthermore, please refer to Figure 1 , in an embodiment of the present invention, the steam turbine heating system 100 further includes a first extraction bypass 8, and the first extraction bypass 8 communicates the first extraction port with the middle part of the first extraction pipeline 3. During the non-cylinder-cutting operation period, in order to increase the steam inlet volume and flow rate of the first extraction pipeline 3 and the first low-pressure heater 4, by adding the first extraction bypass 8 in the form of two pipelines converging in the middle section of the first extraction pipeline 3, the steam inlet volume of the first low-pressure heater 4 is thus increased.

[0035] Even further, please refer to Figure 1 , in an embodiment of the present invention, a first electric valve 8a is provided on the first extraction bypass 8. During the cylinder-cutting operation period, when the steam inlet volume in the first extraction pipeline is large, the first electric valve 8a is closed, and only one pipeline is reserved for steam inlet, reducing the steam inlet volume of the first extraction pipeline to prevent overloading of the first extraction pipeline 3 and the first low-pressure heater 4.

[0036] To maximize the utilization of the heat energy generated by the steam turbine and improve the thermal efficiency and economy of the entire steam turbine heating system 100, please refer to Figure 1, in an embodiment of the present utility model, the steam turbine heating system 100 further includes a heating supply pipeline 9. The upstream of the heating supply pipeline 9 is connected to the first extraction port, and the downstream of the heating supply pipeline 9 is connected to a low-pressure industrial user 17 and a heating extraction user 16. In this way, the main steam of the intermediate-pressure cylinder 1 is directly sent to the low-pressure industrial user 17 and the heating extraction user 16 for heating, greatly increasing the heating capacity of the unit, meeting the heating demand of the city, and sharing the extraction flow for the first extraction pipeline 3, reducing the risk of overloading operation of the first extraction pipeline 3 and the first low-pressure heater 4.

[0037] Specifically, please refer to Figure 1 , in an embodiment of the present utility model, on the heating supply pipeline 9 along the direction from the intermediate-pressure cylinder 1 to the heating extraction user 16, there are successively arranged a heating extraction check valve 9a, a heating extraction regulating valve 9b, and a heating extraction electric valve 9c. The heating extraction check valve 9a can prevent the steam from flowing back in the pipeline, ensuring that the steam can only flow from the steam turbine extraction port to the heating users, avoiding overheating or damage of the steam turbine caused by steam backflow, and ensuring the safety of the system. By setting the heating extraction regulating valve 9b to adjust the steam flow entering the heating users to adapt to different heat load demands, the flexibility of the heating system can be improved, the heating capacity can be adjusted according to actual needs, and the thermal energy utilization efficiency can be increased. The heating extraction electric valve 9c can be remotely opened and closed through electric control to achieve automatic control, improve the convenience of operation and the automation level of the system, reduce manual operation, and reduce the operation risk. Through the coordinated use of the above valves, precise adjustment and control of the heating system can be achieved, ensuring that the heating system can operate stably under various working conditions, meeting the heat demand of users, and at the same time improving the energy utilization efficiency.

[0038] Furthermore, please refer to Figure 1 , in an embodiment of the present utility model, the steam turbine heating system 100 further includes a low-pressure cylinder 2 exhaust pipeline and a condenser 11. The low-pressure cylinder 2 also has an exhaust port, and the low-pressure cylinder 2 exhaust pipeline connects the exhaust port and the condenser 11. During the non-cylinder-cutting operation period, except for the extraction of the heat network, most of the high-temperature and high-pressure steam of the low-pressure cylinder 2 enters the condenser 11 through the exhaust pipeline. The steam exchanges heat with the circulating cooling water inside the condenser 11, and the waste heat can be fully utilized. The condensed water is collected at the bottom of the condenser 11 to form condensate. The condensate usually contains dissolved gases and impurities and needs to be further treated before being sent back to the boiler, realizing the recycling of water resources.

[0039] Furthermore, please refer to Figure 1, in an embodiment of the present utility model, the steam turbine heating system 100 further includes a third extraction steam pipeline 12, a third low-pressure heater 13, a fourth extraction steam pipeline 14, and a fourth low-pressure heater 15. The low-pressure cylinder 2 further has a third extraction steam port and a fourth extraction steam port. The third extraction steam pipeline 12 connects the third extraction steam port and the third low-pressure heater 13, and the fourth extraction steam pipeline 14 connects the fourth extraction steam port and the fourth low-pressure heater 15. In the part of the low-pressure cylinder 2, after the first-stage extraction steam of the low-pressure cylinder 2, a second-stage extraction steam and a third-stage extraction steam, as well as corresponding low-pressure heaters, are provided. The purpose of the multi-stage extraction steam and the multi-stage low-pressure heaters is to improve the thermal efficiency and economy of the cogeneration system, and at the same time increase the flexibility and adaptability of the system. The multi-stage extraction steam allows steam to be extracted from the impellers of different pressure levels of the steam turbine to achieve cascaded utilization of energy. These steam parameters are suitable for the needs of different heat users. The multi-stage low-pressure heaters are used to heat water at different temperatures to meet the requirements of different heat loads. Through this cascaded utilization, the heat generated by the steam turbine can be utilized more effectively, and the thermal efficiency of the entire system can be improved.

[0040] Furthermore, please refer to Figure 1 , in an embodiment of the present utility model, the third low-pressure heater 13 and the fourth low-pressure heater 15 are installed in the condenser 11. The steam turbine heating system 100 further includes a liquid-phase pipeline, which successively connects the condenser 11, the fourth low-pressure heater 15, the third low-pressure heater 13, the second low-pressure heater 6, the first low-pressure heater 4, and extends out of the first low-pressure heater 4. The third low-pressure heater 13 and the fourth low-pressure heater 15 are installed on the condenser 11 and pass through the condenser 11. However, the steam and water two-phase pipelines of the above low-pressure heaters are not directly connected, and the third low-pressure heater 13 and the fourth low-pressure heater 15 are not integrated. They are connected in series through the liquid-phase pipeline. In this way, installing the low-pressure heaters near the condenser 11 can reduce the pipeline length and heat loss, and improve the heat exchange efficiency. By connecting the condenser 11 and each stage of low-pressure heaters in series through the liquid-phase pipeline, the condensate water can be heated step by step, improving the thermal utilization rate of the system. The condensate water is preheated in advance before returning to the boiler, reducing the boiler energy consumption and enabling the recycling of water resources.

[0041] In order to improve the controllability and safety of the steam turbine heating system 100, please refer to Figure 1, in an embodiment of the present utility model, a second electric valve 3a and a first check valve 3b are sequentially arranged on the first extraction steam pipeline 3 along the direction from the intermediate pressure cylinder 1 to the first low-pressure heater 4, and / or, a second check valve 5b and a third electric valve 5a are sequentially arranged on the second extraction steam pipeline 5 along the direction from the low-pressure cylinder 2 to the second low-pressure heater 6. The second electric valve 3a and the third electric valve 5a can be remotely controlled, allowing operators to quickly adjust the extraction steam flow according to actual heating requirements, thereby improving the controllability of the system. The first check valve 3b and the second check valve 5b can prevent steam from flowing back in the pipeline, avoiding possible overheating or damage of the steam turbine, thereby improving the safety of the system. By precisely controlling the extraction steam flow, it can ensure that the condensate water in the low-pressure heater is fully heated, improving the utilization efficiency of thermal energy.

[0042] The above description is only an exemplary embodiment of the present utility model, and does not limit the patent scope of the present utility model. Any equivalent structural transformation made under the technical concept of the present utility model by using the content of the specification and drawings of the present utility model, or direct / indirect application in other related technical fields, is included in the patent protection scope of the present utility model.

Claims

1. A steam turbine heating system (100), characterized in that: The steam turbine heating system (100) comprises an intermediate pressure cylinder (1), a low pressure cylinder (2), a first low pressure heater (4), a first steam extraction pipeline (3), a second low pressure heater (6), a second steam extraction pipeline (5) and a connecting pipeline (7), wherein the intermediate pressure cylinder (1) has a first steam extraction port, and the low pressure cylinder (2) has a second steam extraction port; The low-pressure cylinder (2) is located downstream of the medium-pressure cylinder (1); the first steam extraction pipeline (3) connects the first steam extraction port with the first low-pressure heater (4); the second steam extraction pipeline (5) connects the second steam extraction port with the second low-pressure heater (6); and the connecting pipeline (7) connects the first steam extraction pipeline (3) with the second steam extraction pipeline (5).

2. The steam turbine heating system (100) according to claim 1, characterized in that: A communication electric valve (7a) and a communication check valve (7b) are sequentially provided on the communication pipeline (7) along the direction from the first steam extraction pipeline (3) to the second steam extraction pipeline (5).

3. The steam turbine heating system (100) according to claim 1, characterized in that: The steam turbine heating system (100) further comprises a first steam extraction bypass (8), wherein the first steam extraction bypass (8) is connected to the first steam extraction port and the middle part of the first steam extraction pipeline (3).

4. The steam turbine heating system (100) according to claim 3, characterized in that: The first steam extraction bypass (8) is provided with a first electric valve (8a).

5. The steam turbine heating system (100) according to claim 1, characterized in that: The steam turbine heating system (100) further comprises a heating and heat supply pipeline (9), wherein the heating and heat supply pipeline (9) is connected to a first steam extraction port at its upstream, and connected to a low-pressure industrial user (17) and a heating steam extraction user (16) at its downstream.

6. The steam turbine heating system (100) according to claim 5, characterized in that: The heating supply pipeline (9) is provided with a heating steam extraction check valve (9a), a heating steam extraction regulating valve (9b), and a heating steam extraction electric valve (9c) in sequence along the direction from the medium pressure cylinder (1) to the heating steam extraction user (16).

7. The steam turbine heating system (100) according to claim 1, characterized in that: The steam turbine heating system (100) further comprises a low-pressure cylinder (2) exhaust pipeline and a condenser (11); the low-pressure cylinder (2) also has an exhaust port; the low-pressure cylinder (2) exhaust pipeline connects the exhaust port and the condenser (11).

8. The steam turbine heating system (100) according to claim 7, characterized in that: The steam turbine heating system (100) further comprises a third steam extraction pipeline (12), a third low-pressure heater (13), a fourth steam extraction pipeline (14) and a fourth low-pressure heater (15); the low-pressure cylinder (2) further comprises a third steam extraction port and a fourth steam extraction port; The third steam extraction pipeline (12) is connected to the third steam extraction port and the third low-pressure heater (13), and the fourth steam extraction pipeline (14) is connected to the fourth steam extraction port and the fourth low-pressure heater (15).

9. The steam turbine heating system (100) according to claim 8, characterized in that: The third low-pressure heater (13) and the fourth low-pressure heater (15) are installed on the condenser (11), and the turbine heating system (100) also includes a liquid phase pipeline, which is connected to the condenser (11), the fourth low-pressure heater (15), the third low-pressure heater (13), the second low-pressure heater (6), and the first low-pressure heater (4) in sequence, and extends out of the first low-pressure heater (4).

10. The steam turbine heating system (100) according to claim 1, characterized in that: A second electric valve (3a) and a first check valve (3b) are sequentially arranged on the first steam extraction pipeline (3) along a direction from the intermediate pressure cylinder (1) to the first low pressure heater (4); And / or, a second check valve (5b) and a third electric valve (5a) are sequentially arranged on the second steam extraction pipeline (5) along the direction from the low-pressure cylinder (2) to the second low-pressure heater (6).

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