Steam turbine unit adjustable steam supply system

Abstract

This invention provides an adjustable steam supply system for a steam turbine unit, belonging to the field of industrial steam supply. The system includes: a steam turbine unit comprising a boiler, a high-pressure cylinder, and a steam supply pipeline; the input end of the steam supply pipeline is connected to the reheat exhaust end of the boiler, and its output end is connected to the intermediate-pressure cylinder; the reheat exhaust end of the boiler is connected to the steam inlet end of the high-pressure cylinder; a steam-consuming end is connected to the output end of the steam supply pipeline; a control component for monitoring the operating status data of the high-pressure cylinder and generating control commands for the current operating condition based on the high-pressure cylinder's operating status data; and a valve component installed on the steam supply pipeline for adjusting the steam flow rate discharged from the boiler upon receiving the control command for the current operating condition, thereby meeting the steam flow rate requirements of the intermediate-pressure cylinder and the steam-consuming end under the current operating condition. This invention can meet the steam flow rate requirements of the intermediate-pressure cylinder and the steam-consuming end under different operating conditions, with low modification costs and reliable operational flexibility.

Description

Technical Field

[0001] This invention relates to the field of industrial steam supply, and more specifically to an adjustable steam supply system for a steam turbine unit. Background Technology

[0002] With the acceleration of urbanization, thermal power units need to adapt to the development requirements of the new power system. Therefore, it is inevitable to promote the implementation of heating transformation of thermal power units and participate in deep peak-shaving operation. The largest component of my country's existing cogeneration units is condensing units. Therefore, the high-efficiency cogeneration transformation of condensing units is the top priority of my country's cogeneration industry development.

[0003] As can be seen from the unit's operating characteristics, under low to medium load conditions, the extraction steam pressure parameters of each section of the unit will drop sharply, resulting in the supply steam pressure parameters failing to meet the user's steam demand. In addition, due to the increase in user demand, the original extraction steam supply capacity of some units has reached its limit, and it is necessary to further increase the steam supply capacity.

[0004] Currently, the main methods to improve steam supply are as follows: (1) Cold re-extraction steam scheme. The cold re-extraction steam scheme is constrained by the matching of boiler and turbine heat load. To further increase the quantity, it is necessary to carry out irreversible modification of the boiler heating surface; (2) Hot re-extraction steam scheme. Although it has no significant negative impact on boiler operation, has a large steam extraction potential, and is technically controllable, as the unit participates in deep peak shaving more and more frequently, the steam supply is also increasing. When the unit is below 40% load, problems such as low steam supply pressure parameters and insufficient flow adjustment margin will occur, which will restrict the stability and reliability of steam supply. To improve the stability and reliability of steam supply, it is necessary to modify the intermediate pressure cylinder valve parameters. However, modifying the intermediate pressure cylinder valve parameters will lead to problems such as high cost, irreversibility, and insufficient flexibility.

[0005] In general, existing steam supply improvement schemes suffer from irreversible modifications, high costs, and insufficient flexibility. Summary of the Invention

[0006] The purpose of this invention is to provide an adjustable steam supply system for steam turbine units to solve the problems of irreversible modification, high cost, and insufficient flexibility in existing steam supply improvement schemes.

[0007] To achieve the above objectives, embodiments of the present invention provide an adjustable steam supply system for a steam turbine unit, comprising:

[0008] A steam turbine unit includes a boiler, a high-pressure cylinder, an intermediate-pressure cylinder, and a steam supply pipeline. The reheat exhaust end of the boiler is connected to the input end of the steam supply pipeline, the output end of the steam supply pipeline is connected to the intermediate-pressure cylinder, and the reheat exhaust end of the boiler is connected to the inlet end of the high-pressure cylinder.

[0009] The steam-using end is connected to the output end of the steam supply pipeline;

[0010] Monitoring components are used to monitor the operating status data of the high-pressure cylinder;

[0011] The control component is used to generate control commands for the current operating conditions based on the operating status data of the high-pressure cylinder.

[0012] The valve assembly, located on the steam supply pipeline, is used to regulate the steam flow from the boiler to the intermediate pressure cylinder and the steam consumption end when a control command is received, so as to meet the steam flow requirements of the intermediate pressure cylinder and the steam consumption end under the current operating conditions.

[0013] Optionally, the turbine unit also includes: a main steam pipeline and a cold-end steam reheat pipeline; a steam supply pipeline including: an intermediate-pressure cylinder extraction steam pipeline and an industrial steam supply pipeline; a valve assembly including: a first valve assembly and a second valve assembly; a monitoring assembly including: a regulating stage pressure monitoring unit and a high-pressure cylinder exhaust pressure monitoring unit; a control assembly including: a pressure ratio calculation module, an operating condition determination module, an operating strategy generation module, and a first command generation module; and high-pressure cylinder operating status data including: high-pressure cylinder regulating stage pressure and high-pressure cylinder exhaust pressure.

[0014] The two ends of the main steam pipeline are connected to the reheat exhaust end of the boiler and the steam inlet end of the high-pressure cylinder, respectively. The two ends of the cold end steam reheat pipeline are connected to the hot reheat steam end of the boiler and the exhaust end of the high-pressure cylinder, respectively. The two ends of the intermediate pressure cylinder extraction steam pipeline are connected to the hot reheat steam end of the boiler and the extraction end of the intermediate pressure cylinder, respectively. The two ends of the industrial steam supply pipeline are connected to the intermediate pressure cylinder extraction steam pipeline and the input end of the steam consumption end, respectively. The first valve assembly is set on the intermediate pressure cylinder extraction steam pipeline, and the second valve assembly is set on the industrial steam supply pipeline. The regulating stage pressure monitoring unit and the high-pressure cylinder exhaust steam pressure monitoring unit are both set inside the high-pressure cylinder, respectively used to monitor the regulating stage pressure of the high-pressure cylinder and the exhaust steam pressure of the high-pressure cylinder.

[0015] The pressure ratio calculation module is used to calculate the pressure of the high-pressure cylinder regulating stage and the high-pressure cylinder exhaust pressure using formula (1) to obtain the pressure ratio of the high-pressure cylinder.

[0016] Where K = P g / P pex K represents the high-pressure cylinder pressure ratio; P g Indicates the pressure of the high-pressure cylinder regulating stage; P pex Indicates the exhaust pressure of the high-pressure cylinder;

[0017] The operating condition determination module is used to determine the current operating condition based on the high-pressure cylinder pressure ratio and a preset pressure ratio range.

[0018] The operation strategy generation module is used to match the current operating conditions with the preset valve operating condition mapping table to determine the operating conditions of the valve components; wherein, the preset valve operating condition mapping table includes different operating conditions and their corresponding valve operating conditions;

[0019] The first instruction generation module is used to generate control instructions for the current operating condition based on the operating conditions of the valve assembly.

[0020] The first valve assembly is used to regulate the steam flow from the boiler to the intermediate pressure cylinder and the industrial steam supply pipeline when a control command is received under the current operating conditions, so as to meet the steam flow requirements of the intermediate pressure cylinder under the current operating conditions.

[0021] The second valve assembly is used to regulate the steam flow rate from the industrial steam supply line to the steam consumption end to meet the steam flow rate requirements of the steam consumption end under the current operating conditions.

[0022] Optionally, the monitoring component further includes: a high-pressure cylinder exhaust temperature monitoring unit; the control component further includes: a high-pressure cylinder exhaust data processing module and a second instruction generation module; the operating status data of the high-pressure cylinder further includes: the high-pressure cylinder exhaust temperature; the high-pressure cylinder exhaust temperature monitoring unit is installed on the cold end reheat pipeline and is used to monitor the high-pressure cylinder exhaust temperature;

[0023] The high-pressure cylinder exhaust data processing module is used to determine the switching rate of valve components corresponding to the current operating conditions based on the high-pressure cylinder exhaust temperature and the preset high-pressure cylinder exhaust temperature.

[0024] The second instruction generation module is used to generate rate adjustment instructions based on the switching rate of the valve assembly;

[0025] The first valve assembly is also used to control the flow rate of the steam discharged from the boiler to the intermediate pressure cylinder and the industrial steam supply line when a rate regulation command is received, so as to meet the steam flow requirements of the intermediate pressure cylinder under the current operating conditions.

[0026] Optionally, the first valve assembly includes: a main electric regulating valve and an auxiliary electric regulating valve arranged in parallel on the main reheat steam supply line; the second valve assembly includes: a manual shut-off regulating valve;

[0027] The main electric regulating valve and the auxiliary electric regulating valve are used to adjust the steam flow from the boiler to the intermediate pressure cylinder and the industrial steam supply pipeline when a control command is received, so as to meet the steam flow requirements of the intermediate pressure cylinder under the current operating conditions.

[0028] Manual shut-off valves are used to regulate the steam flow rate from the industrial steam supply line to the steam consumption end to meet the steam flow rate requirements of the steam consumption end under the current operating conditions.

[0029] Optionally, the intermediate pressure cylinder extraction steam pipeline is also equipped with a first boiler exhaust steam pressure monitoring unit, a first boiler exhaust steam temperature monitoring unit, a second boiler exhaust steam pressure monitoring unit, and a second boiler exhaust steam temperature monitoring unit. The first boiler exhaust steam pressure monitoring unit and the first boiler exhaust steam temperature monitoring unit are both located at the front end of the first valve assembly, and the second boiler exhaust steam pressure monitoring unit and the second boiler exhaust steam temperature monitoring unit are both located at the rear end of the first valve assembly.

[0030] The first boiler exhaust pressure monitoring unit is used to monitor the steam pressure of the steam discharged from the boiler;

[0031] The first boiler exhaust temperature monitoring unit is used to monitor the steam temperature of the steam discharged from the boiler.

[0032] The second boiler exhaust pressure monitoring unit is used to monitor the steam pressure of the steam discharged from the boiler and regulated by the first valve assembly;

[0033] The second boiler exhaust temperature monitoring unit is used to monitor the steam temperature of the steam discharged from the boiler and regulated by the first valve assembly.

[0034] Optionally, the second valve assembly further includes: a throttling orifice disposed on the industrial steam supply line; the throttling orifice is located at the front end of the manually shut-off regulating valve.

[0035] Optionally, the second valve assembly further includes: a pneumatic check valve, an electric regulating valve, a pressure reducing valve, and a pneumatic quick-closing valve installed on the industrial steam supply pipeline; the pneumatic check valve, the electric regulating valve, the pressure reducing valve, and the pneumatic quick-closing valve are sequentially installed at the rear end of the manual shut-off regulating valve along the direction of steam discharge from the boiler to the steam consumption end.

[0036] Optionally, steam in the steam supply pipeline is regulated by a pneumatic quick-closing valve before being introduced into the desuperheating water system.

[0037] Optionally, the second valve assembly also includes: a safety valve located on the industrial steam supply line; the safety valve is located at the rear end of the desuperheating water system.

[0038] Optionally, the industrial steam supply pipeline is also equipped with an industrial steam supply pressure monitoring unit, an industrial steam supply temperature monitoring unit, and an industrial steam supply flow monitoring unit; the industrial steam supply pressure monitoring unit, industrial steam supply temperature monitoring unit, and industrial steam supply flow monitoring unit are all located at the rear end of the safety valve;

[0039] The industrial steam supply pressure monitoring unit is used to monitor the steam pressure of steam discharged from the industrial steam supply pipeline;

[0040] The industrial steam supply temperature monitoring unit is used to monitor the steam temperature of the steam discharged from the industrial steam supply pipeline;

[0041] The industrial steam supply flow monitoring unit is used to monitor the steam flow rate of steam discharged from the industrial steam supply pipeline.

[0042] In this embodiment, the high-pressure cylinder regulating stage pressure and high-pressure cylinder exhaust pressure are monitored by the regulating stage pressure monitoring unit and the high-pressure cylinder exhaust pressure monitoring unit. Then, the pressure ratio calculation module calculates the high-pressure cylinder regulating stage pressure and high-pressure cylinder exhaust pressure using formula (1) to obtain the high-pressure cylinder pressure ratio. Then, the operating condition determination module determines the current operating condition based on the high-pressure cylinder pressure ratio and the preset pressure ratio range. Then, the operating strategy generation module matches the current operating condition with the preset valve operating condition mapping table to determine the operating conditions of the valve component corresponding to the current operating condition. Then, the first instruction generation module generates the control instruction under the current operating condition based on the operating conditions of the valve component corresponding to the current operating condition. Finally, the control instruction under the current operating condition is sent to the valve component, so that the valve component adjusts the steam flow from the boiler to the intermediate pressure cylinder and the steam consumption end. This not only meets the steam flow requirements of the intermediate pressure cylinder and the steam consumption end under the current operating condition, but also has low modification cost and reliable operation flexibility.

[0043] Other features and advantages of the embodiments of the present invention will be described in detail in the following detailed description section. Attached Figure Description

[0044] The accompanying drawings are provided to further illustrate embodiments of the present invention and form part of the specification. They are used together with the following detailed description to explain the embodiments of the present invention, but do not constitute a limitation thereof. In the drawings:

[0045] Figure 1 This is a schematic diagram of the adjustable steam supply system for a steam turbine unit provided in an embodiment of the present invention.

[0046] Explanation of reference numerals in the attached figures

[0047] 11. Boiler; 12. High-pressure cylinder; 13. Medium-pressure cylinder; 14. Cold-end steam reheat pipeline;

[0048] 15. Main steam pipeline; 16. Intermediate pressure cylinder extraction steam pipeline; 21. Intermediate pressure cylinder extraction steam bypass;

[0049] 22. Main electric regulating valve; 23. Auxiliary electric regulating valve; 31. Industrial steam supply pipeline;

[0050] 32. Throttling orifice; 33. Manual shut-off regulating valve; 34. Pneumatic check valve;

[0051] 35. Electric regulating valve; 36. Pressure reducing valve; 37. Pneumatic quick-closing valve; 38. Safety valve;

[0052] 39. Desuperheating water system; 40. Steam consumption end; T20. First boiler exhaust steam temperature monitoring unit;

[0053] P20, First boiler exhaust pressure monitoring unit; T21, Second boiler exhaust temperature monitoring unit;

[0054] P21, First Boiler Exhaust Pressure Monitoring Unit; P22, Industrial Steam Supply Pressure Monitoring Unit;

[0055] T22, Industrial steam supply temperature monitoring unit; Q22, Industrial steam supply flow monitoring unit;

[0056] Pg, regulating stage pressure monitoring unit; P3, high-pressure cylinder extraction steam pressure monitoring unit;

[0057] Pex, high-pressure cylinder exhaust pressure monitoring unit; Tex, high-pressure cylinder exhaust temperature monitoring unit. Detailed Implementation

[0058] The specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are for illustration and explanation only and are not intended to limit the scope of the present invention.

[0059] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs; the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit this application.

[0060] In the description of the embodiments of this application, technical terms such as "first" and "second" are used only to distinguish different objects and should not be construed as indicating or implying relative importance or implicitly specifying the number, specific order, or primary and secondary relationship of the indicated technical features. In the description of the embodiments of this application, "multiple" means two or more, unless otherwise explicitly defined.

[0061] Please refer to Figure 1 , Figure 1This is a schematic diagram of the adjustable steam supply system for a steam turbine unit provided in an embodiment of the present invention. The system includes: a steam turbine unit, including a boiler 11, a high-pressure cylinder 12, an intermediate-pressure cylinder 13, and a steam supply pipeline. The reheat exhaust end of the boiler 11 is connected to the input end of the steam supply pipeline, the output end of the steam supply pipeline is connected to the intermediate-pressure cylinder 13, and the reheat steam end of the boiler 11 is connected to the exhaust end of the high-pressure cylinder 12; a steam consumption end 40 is connected to the output end of the steam supply pipeline; a monitoring component for monitoring the operating status data of the high-pressure cylinder; a control component for generating control commands under the current operating conditions based on the operating status data of the high-pressure cylinder; and a valve component, installed on the steam supply pipeline, for adjusting the steam flow rate from the boiler 11 to the intermediate-pressure cylinder 13 and the steam consumption end 40 when the control command is received, so as to meet the steam flow rate requirements of the intermediate-pressure cylinder 13 and the steam flow rate requirements of the steam consumption end 40 under the current operating conditions.

[0062] In one embodiment, the turbine unit further includes: a main steam pipeline 15 and a cold-end steam reheat pipeline 14; a steam supply pipeline including: an extraction steam pipeline for the intermediate-pressure cylinder 13 and an industrial steam supply pipeline 31; a valve assembly including: a first valve assembly and a second valve assembly; a monitoring assembly including: a regulating stage pressure monitoring unit Pg and a high-pressure cylinder exhaust pressure monitoring unit Pex; a control assembly including: a pressure ratio calculation module, an operating condition determination module, an operating strategy generation module, and a first instruction generation module; the operating status data of the high-pressure cylinder includes: the high-pressure cylinder regulating stage pressure and the high-pressure cylinder exhaust pressure; the two ends of the main steam pipeline 15 are respectively connected to the boiler 11. The reheat exhaust end of the boiler 11 and the steam inlet end of the high-pressure cylinder 12 are connected to the reheat steam end of the boiler 11 and the exhaust end of the high-pressure cylinder 12, respectively. The two ends of the extraction steam pipeline of the intermediate-pressure cylinder 13 are connected to the reheat steam end of the boiler 11 and the extraction steam end of the intermediate-pressure cylinder 13, respectively. The two ends of the industrial steam supply pipeline 31 are connected to the extraction steam pipeline of the intermediate-pressure cylinder 13 and the input end of the steam consumption end 40, respectively. The first valve assembly is set on the extraction steam pipeline of the intermediate-pressure cylinder 13, and the second valve assembly is set on the industrial steam supply pipeline 31. The regulating stage pressure monitoring unit Pg and the high-pressure cylinder exhaust pressure monitoring unit Pex are both set inside the high-pressure cylinder 12. The pressure ratio calculation module is used to calculate the pressure ratio of the high-pressure cylinder regulating stage and the high-pressure cylinder exhaust pressure using formula (1); where K = Pg / Pex, K represents the high-pressure cylinder pressure ratio; Pg represents the high-pressure cylinder regulating stage pressure; Pex represents the high-pressure cylinder exhaust pressure; the operating condition determination module is used to determine the current operating condition based on the high-pressure cylinder pressure ratio and the preset pressure ratio range; the operating strategy generation module is used to match the current operating condition with the preset valve operating condition mapping table to determine the operating conditions of the valve components; The preset valve operating condition mapping table includes different operating conditions and their corresponding valve operating conditions; the first instruction generation module is used to generate control instructions for the current operating condition based on the operating conditions of the valve components; the first valve component is used to adjust the steam flow from the boiler 11 to the intermediate pressure cylinder 13 and the industrial steam supply pipeline 31 when it receives the control instructions for the current operating condition, so as to meet the steam flow requirements of the intermediate pressure cylinder 13 under the current operating condition; the second valve component is used to adjust the steam flow from the industrial steam supply pipeline 31 to the steam consumption end 40, so as to meet the steam flow requirements of the steam consumption end 40 under the current operating condition.

[0063] In one embodiment, the first valve assembly includes a main electric regulating valve 22 and an auxiliary electric regulating valve 23 connected in parallel on the main reheat steam supply line; the second valve assembly includes a manual shut-off regulating valve 33; the main electric regulating valve 22 and the auxiliary electric regulating valve 23 are used to coordinate and regulate the steam flow from the boiler 11 to the intermediate pressure cylinder 13 and the industrial steam supply line 31 when a control command is received, so as to meet the steam flow demand of the intermediate pressure cylinder 13 under the current operating conditions; the manual shut-off valve is used to regulate the steam flow from the industrial steam supply line 31 to the steam consumption end 40, so as to meet the steam flow demand of the steam consumption end 40 under the current operating conditions.

[0064] The main electric regulating valve 22 and the auxiliary electric regulating valve 23 can be arranged such that the input end and output end of the intermediate pressure cylinder extraction bypass 21 are respectively set at the front end and the rear end of the main electric regulating valve 22, while the auxiliary electric regulating valve 23 is set on the intermediate pressure cylinder extraction bypass 21 to form a parallel relationship.

[0065] Understandably, the main electric regulating valve 22 and the auxiliary electric regulating valve 23 in the first valve assembly are electric valves, meaning they need to be controlled to open or close by issuing commands through the control assembly, while the second valve assembly is a manual valve, meaning it needs to be manually opened or closed.

[0066] It should be noted that the main electric regulating valve 22 is designed as a leakage valve, and the main electric regulating valve 22 has a greater capacity to regulate flow than the auxiliary electric regulating valve 23. When the main electric regulating valve 22 is closed, the steam flow that can pass through the annular gap of the main electric regulating valve 22 can meet the minimum steam flow requirement of the intermediate pressure cylinder 13 of the unit to ensure the safe operation of the unit. At this time, the energy after being regulated by the auxiliary electric regulating valve 23 can meet the minimum steam flow requirement of the steam-consuming end.

[0067] The preset pressure ratio range is used to characterize the range of the high-pressure cylinder pressure ratio under different operating conditions, including but not limited to: the pressure ratio range under pure condensing conditions, the pressure ratio range under conditions where the thermoelectric coupling contradiction of the unit is prominent, and the pressure ratio range under conditions where the thermoelectric coupling contradiction of the unit is not prominent. In other words, it is the range of the high-pressure cylinder pressure ratio under which operating condition the high-pressure cylinder pressure ratio is located, that is, which operating condition it belongs to.

[0068] In one embodiment, the relationship between the high-pressure cylinder pressure ratio and the operating conditions can be referred to Table 1 below:

[0069]

[0070]

[0071] Table 1

[0072] For example, when the pressure ratio of the high-pressure cylinder is 6, it falls within the range of 5-8 for pure condensing conditions, indicating that the turbine unit is currently in pure condensing conditions.

[0073] In one embodiment, the preset valve operating condition mapping table can be referred to as Table 2 below:

[0074] Pure condensation condition Open Open Unit operating conditions with prominent thermoelectric coupling contradictions closure Open Operating conditions where the thermoelectric coupling contradiction of the unit is not prominent Open Open

[0075] Table 2

[0076] The principle behind Table 2 above is explained below:

[0077] When the turbine unit is in pure condensing operation, it means that the turbine unit does not supply steam to the outside at this time. That is, it only meets the steam flow requirements of the high-pressure cylinder and the low-pressure cylinder, and is isolated from the steam consumption end 40. Therefore, at this time, the main electric regulating valve 22 and the auxiliary electric regulating valve 23 need to be fully opened.

[0078] When the turbine unit is in a condition where the thermoelectric coupling contradiction is prominent, it means that the electrical load rate of the turbine unit is low at this time, and normal operation is difficult to meet the steam flow demand of the steam consumption end 40. In order to meet the flow demand of the steam consumption end 40, the steam flow demand of the intermediate pressure cylinder is minimized. Therefore, at this time, the main electric regulating valve 22 needs to be closed, the auxiliary electric regulating valve 23 needs to be opened, and the manual shut-off regulating valve 33 needs to be opened.

[0079] When the turbine unit is in a condition where the thermoelectric coupling contradiction is not prominent, it means that the turbine unit has a high load rate at this time, which can easily meet the steam demand of the steam consumption end 40, that is, fully meet the steam flow demand of the intermediate pressure cylinder 13 and the flow demand of the steam consumption end 40. Therefore, the main electric regulating valve 22, the auxiliary electric regulating valve 23 and the manual shut-off regulating valve 33 are all opened.

[0080] For ease of understanding, the following are examples of steam flow regulation processes for steam turbine units under three operating conditions:

[0081] I. Pure Condensation Condition

[0082] Assuming the high-pressure cylinder regulating stage pressure is 10 MPa and the high-pressure cylinder exhaust pressure is 2 MPa, formula (1) is used to calculate the high-pressure cylinder regulating stage pressure and the high-pressure cylinder exhaust pressure, resulting in a high-pressure cylinder pressure ratio of 5. This high-pressure cylinder pressure ratio is then matched with the pressure ratio ranges under pure condensing conditions, the pressure ratio ranges under conditions with prominent thermoelectric coupling contradictions, and the pressure ratio ranges under conditions with non-prominent thermoelectric coupling contradictions. Finally, it is determined that the high-pressure cylinder pressure ratio falls within the pure condensing condition pressure ratio range, indicating that the turbine unit is in pure condensing condition. Then, the pure condensing condition is matched with the preset valve operating condition mapping table. Table 2 shows that... Under pure condensing conditions, the valve assembly operates under the condition that both the main electric regulating valve 22 and the auxiliary electric regulating valve 23 are open. Then, based on the fact that both the main electric regulating valve 22 and the auxiliary electric regulating valve 23 are open, a control command is generated. Finally, when the first valve assembly receives the control command, both the main electric regulating valve 22 and the auxiliary electric regulating valve 23 are opened. Then, the regulating valve 33 is shut off by manual means, so that the steam discharged from the boiler 11 flows only to the high-pressure cylinder 12 and the intermediate-pressure cylinder 13 through the main steam pipeline 15 and the intermediate-pressure cylinder extraction steam pipeline 16. That is, the turbine unit does not supply steam to the outside, completely isolating the steam-consuming end 40, thereby ensuring the safe and stable operation of the turbine unit.

[0083] II. During steam supply operation, when the thermoelectric coupling contradiction of the unit is prominent.

[0084] Assuming the high-pressure cylinder regulating stage pressure is 8 MPa and the high-pressure cylinder exhaust pressure is 2 MPa, formula (1) is used to calculate the high-pressure cylinder regulating stage pressure and the high-pressure cylinder exhaust pressure, resulting in a high-pressure cylinder pressure ratio of 4. This high-pressure cylinder pressure ratio is then matched with the pressure ratio ranges under pure condensing conditions, the pressure ratio ranges under conditions of prominent thermoelectric coupling contradictions in the unit, and the pressure ratio ranges under conditions of non-prominent thermoelectric coupling contradictions in the unit. Finally, it is determined that the high-pressure cylinder pressure ratio falls within the pressure ratio range under conditions of prominent thermoelectric coupling contradictions in the unit, indicating that the turbine unit is under conditions of prominent thermoelectric coupling contradictions. Then, the conditions of prominent thermoelectric coupling contradictions in the unit are matched with the preset valve operating condition mapping table. Table 2 shows that the conditions of prominent thermoelectric coupling contradictions in the unit... Under the following conditions, the valve assembly operates with both the main electric regulating valve 22 and the auxiliary electric regulating valve 23 open. Then, based on the main electric regulating valve 22 being closed and the auxiliary electric regulating valve 23 being open, a control command is generated. Finally, when the first valve assembly receives the control command, the main electric regulating valve 22 closes and the auxiliary electric regulating valve 23 opens. Then, the regulating valve 33 is manually closed, so that the steam discharged from the boiler 11 can meet the minimum steam flow requirement of the intermediate pressure cylinder 13 after passing through the annular gap of the main electric regulating valve 22, and the steam discharged from the boiler 11 can meet the minimum steam flow requirement of the steam user end after passing through the auxiliary electric regulating valve 23. That is, the minimum steam flow requirement of the steam user end 40 can be met while ensuring the safe operation of the turbine unit.

[0085] III. During steam supply operation, when the thermoelectric coupling problem of the unit is not prominent.

[0086] Assuming the high-pressure cylinder regulating stage pressure is 10 MPa and the high-pressure cylinder exhaust pressure is 1 MPa, formula (1) is used to calculate the high-pressure cylinder regulating stage pressure and the high-pressure cylinder exhaust pressure, resulting in a high-pressure cylinder pressure ratio of 10. This high-pressure cylinder pressure ratio is then matched with the pressure ratio ranges under pure condensing conditions, the pressure ratio ranges under conditions of prominent thermoelectric coupling contradictions in the unit, and the pressure ratio ranges under conditions of non-prominent thermoelectric coupling contradictions in the unit. Finally, it is determined that the high-pressure cylinder pressure ratio falls within the pressure ratio range under conditions of non-prominent thermoelectric coupling contradictions in the unit, indicating that the turbine unit is under conditions of non-prominent thermoelectric coupling contradictions. Then, the conditions of non-prominent thermoelectric coupling contradictions in the unit are matched with the preset valve operating condition mapping table. Table 2 shows that the unit's thermoelectric coupling contradictions... The operating conditions of the valve assembly under the prominent working condition are that both the main electric regulating valve 22 and the auxiliary electric regulating valve 23 are open, and the manually shut-off regulating valve 33 is in the open state. Then, based on the main electric regulating valve 22 being closed and the auxiliary electric regulating valve 23 being open, a control command is generated. Finally, when the first valve assembly receives the control command, the main electric regulating valve 22 is closed and the auxiliary electric regulating valve 23 is opened. Then, the regulating valve 33 is shut off by manual means, so that the steam discharged from the boiler 11 flows only through the main steam pipeline 15 and the intermediate pressure cylinder extraction steam pipeline 16 to the high pressure cylinder 12 and the intermediate pressure cylinder 13, and through the industrial steam supply pipeline 31 to the steam consumption end. That is, it can meet the large parameter steam flow requirements of the steam consumption end 40 while ensuring the safe operation of the steam turbine unit.

[0087] In this embodiment, the high-pressure cylinder regulating stage pressure and high-pressure cylinder exhaust pressure are monitored by the regulating stage pressure monitoring unit Pg and the high-pressure cylinder exhaust pressure monitoring unit Pex. Then, the pressure ratio calculation module calculates the high-pressure cylinder regulating stage pressure and high-pressure cylinder exhaust pressure using formula (1) to obtain the high-pressure cylinder pressure ratio. Then, the operating condition determination module determines the current operating condition based on the high-pressure cylinder pressure ratio and the preset pressure ratio range. Then, the operating strategy generation module matches the current operating condition with the preset valve operating condition mapping table to determine the operating conditions of the valve component corresponding to the current operating condition. Then, the first instruction generation module generates the control instruction under the current operating condition based on the operating conditions of the valve component corresponding to the current operating condition. Finally, the control instruction under the current operating condition is sent to the valve component, so that the valve component adjusts the steam flow from the boiler to the intermediate pressure cylinder and the steam consumption end. This not only meets the steam flow requirements of the intermediate pressure cylinder and the steam consumption end under the current operating condition, but also has low modification cost and reliable operation flexibility.

[0088] Optionally, the monitoring component further includes: a high-pressure cylinder exhaust temperature monitoring unit Tex; the control component further includes: a high-pressure cylinder exhaust data processing module and a second instruction generation module; the operating status data of the high-pressure cylinder also includes: the high-pressure cylinder exhaust temperature; the high-pressure cylinder exhaust temperature monitoring unit Tex is installed on the cold end reheat pipeline and is used to monitor the high-pressure cylinder exhaust temperature; the high-pressure cylinder exhaust data processing module is used to determine the switching rate of the valve assembly corresponding to the current operating condition based on the high-pressure cylinder exhaust temperature and the preset high-pressure cylinder exhaust temperature; the second instruction generation module is used to generate a rate adjustment instruction based on the switching rate of the valve assembly; the first valve assembly is also used to control the flow rate of the flow discharged from the boiler 11 to the intermediate-pressure cylinder 13 and the industrial steam supply pipeline 31 when it receives the rate adjustment instruction, so as to meet the steam flow demand of the intermediate-pressure cylinder 13 under the current operating condition.

[0089] The preset high-pressure cylinder exhaust temperature varies for different turbine units. For example, in this embodiment, the preset high-pressure cylinder exhaust temperature may be 370°C, while it may be 280°C for other turbine units. Therefore, this embodiment of the invention does not impose a specific limitation on this, and it can be determined based on the manufacturing design value combined with on-site tests.

[0090] Specifically, when the high-pressure cylinder exhaust temperature is close to the preset high-pressure cylinder exhaust temperature, it indicates that the high-pressure cylinder 12 will exceed the rated value of the reheater temperature, which will cause the water spray to increase, thereby increasing the output of the intermediate-pressure cylinder 13. Therefore, the opening rate of the first valve assembly increases at this time. Conversely, when the high-pressure cylinder exhaust temperature is far from the preset high-pressure cylinder exhaust temperature, the opening rate of the first valve assembly decreases.

[0091] In one embodiment, the cold-end steam reheat pipeline 14 is further provided with a high-pressure cylinder extraction steam pressure monitoring unit P3, which is used to monitor the high-pressure cylinder extraction steam pressure as a basis for the safety assessment of the turbine unit.

[0092] In one embodiment, when determining the switching rate of the valve assembly corresponding to the current operating condition based on the high-pressure cylinder exhaust temperature and the preset high-pressure cylinder exhaust temperature, the switching rate of the valve assembly can be further determined by combining the current operating condition.

[0093] For example, when the current operating condition is pure condensation, the output of the intermediate pressure cylinder 13 increases, and the intermediate pressure cylinder 13 needs more flow to meet the operating requirements, so the first valve assembly needs to be opened quickly; when the current operating condition is that the thermoelectric coupling contradiction of the unit is not prominent, the steam flow discharged from the boiler 11 is relatively sufficient. In order to avoid wasting steam flow, the first valve assembly needs to be opened slowly.

[0094] In this embodiment, the high-pressure cylinder exhaust temperature is monitored by the high-pressure cylinder exhaust temperature monitoring unit Tex. Then, the high-pressure cylinder exhaust data processing module determines the opening and closing rate of the valve assembly based on the high-pressure cylinder exhaust temperature and the preset high-pressure cylinder exhaust temperature. Then, the second instruction generation module generates a rate adjustment instruction based on the opening and closing rate of the valve assembly and sends the rate adjustment instruction to the first valve assembly. Finally, when the first valve assembly receives the rate adjustment instruction, it controls the flow rate of the steam discharged from the boiler 11 to the intermediate-pressure cylinder 13 and the industrial steam supply pipeline 31, thereby improving the response speed of steam flow regulation.

[0095] Optionally, the extraction steam pipeline of the intermediate pressure cylinder 13 is further equipped with a first boiler exhaust pressure monitoring unit P20, a first boiler exhaust temperature monitoring unit T20, a second boiler exhaust pressure monitoring unit P21, and a second boiler exhaust temperature monitoring unit T21. The first boiler exhaust pressure monitoring unit P20 and the first boiler exhaust temperature monitoring unit T20 are both located at the front end of the first valve assembly, and the second boiler exhaust pressure monitoring unit P21 and the second boiler exhaust temperature monitoring unit T21 are both located at the rear end of the first valve assembly. The first boiler exhaust pressure monitoring unit P20 is used to monitor the steam pressure of the steam discharged from the boiler 11; the first boiler exhaust temperature monitoring unit T20 is used to monitor the steam temperature of the steam discharged from the boiler 11; the second boiler exhaust pressure monitoring unit P21 is used to monitor the steam pressure of the steam discharged from the boiler 11 and regulated by the first valve assembly; and the second boiler exhaust temperature monitoring unit T21 is used to monitor the steam temperature of the steam discharged from the boiler 11 and regulated by the first valve assembly.

[0096] In this embodiment, by setting a first boiler exhaust pressure monitoring unit P20, a first boiler exhaust temperature monitoring unit T20, a second boiler exhaust pressure monitoring unit P21, and a second boiler exhaust temperature monitoring unit T21 before and after the first valve assembly, the pressure and temperature changes of the steam discharged from the boiler 11 before and after passing through the first valve assembly can be monitored. When there is no change, it indicates that the first valve assembly is damaged. When there is a change, it indicates that the first valve assembly is in normal condition, thereby ensuring the reliability of meeting the steam flow requirements of the intermediate pressure cylinder and the steam flow requirements of the steam-consuming end under the current operating conditions.

[0097] Optionally, the second valve assembly further includes a throttling orifice 32 disposed on the industrial steam supply line 31; the throttling orifice 32 is located at the front end of the manual shut-off regulating valve 33.

[0098] In this embodiment, since the throttle orifice 32 can reduce the steam flow rate discharged from the industrial steam supply line 31 to the steam consumption end 40, the manual shut-off regulating valve 33 can flexibly adjust the steam flow rate discharged from the industrial steam supply line 31 to the steam consumption end 40, thereby avoiding excessive steam flow rate being discharged to the steam consumption end 40.

[0099] Optionally, the second valve assembly further includes: a pneumatic check valve 34, an electric regulating valve 35, a pressure reducing valve 36, and a pneumatic quick-closing valve 37 disposed on the industrial steam supply line 31; the pneumatic check valve 34, the electric regulating valve 35, the pressure reducing valve 36, and the pneumatic quick-closing valve 37 are sequentially disposed at the rear end of the manual shut-off regulating valve 33 along the direction of steam discharged from the boiler 11 to the steam consumption end 40.

[0100] In this embodiment, the different steam flow requirements of the steam-consuming end 40 can be met by adjusting the pneumatic check valve 34, the electric regulating valve 35, the pressure reducing valve 36 and the pneumatic quick-closing valve 37.

[0101] Optionally, the steam in the steam supply pipeline is regulated by the pneumatic quick-closing valve 37 and then input into the desuperheating water system 39.

[0102] Specifically, a bypass can be added to the industrial steam supply line 31 between the pneumatic quick-closing valve 37 and the safety valve 38. The output end of the bypass is connected to the desuperheating water system 39, and a valve is installed on the bypass. The valve is used to prevent or allow steam discharged from the boiler 11 to the steam consumption end 40 to be input to the steam consumption end 40, while the desuperheating water system 39 is used to cool the steam discharged from the boiler 11 to the steam consumption end 40.

[0103] In this embodiment, the steam is cooled by the desuperheating water system 39, which enables the steam to become saturated steam, thereby better meeting the heating demand of the steam user 40.

[0104] Optionally, the second valve assembly also includes a safety valve 38 disposed on the industrial steam supply line 31; the safety valve 38 is located at the rear end of the desuperheating water system 39.

[0105] In this embodiment, when the steam pressure in the industrial steam supply pipeline 31 reaches a threshold, the pressure can be released through the safety valve 38, thereby ensuring that the industrial steam supply pipeline 31 operates in a safe state.

[0106] Optionally, the industrial steam supply pipeline 31 is also equipped with an industrial steam supply pressure monitoring unit P22, an industrial steam supply temperature monitoring unit T22, and an industrial steam supply flow monitoring unit Q22; the industrial steam supply pressure monitoring unit P22, the industrial steam supply temperature monitoring unit T22, and the industrial steam supply flow monitoring unit Q22 are all located at the rear end of the safety valve 38; the industrial steam supply pressure monitoring unit P22 is used to monitor the steam pressure of the steam discharged from the industrial steam supply pipeline 31; the industrial steam supply temperature monitoring unit T22 is used to monitor the steam temperature of the steam discharged from the industrial steam supply pipeline 31; and the industrial steam supply flow monitoring unit Q22 is used to monitor the steam flow rate of the steam discharged from the industrial steam supply pipeline 31.

[0107] In this embodiment, by setting an industrial steam supply pressure monitoring unit P22, an industrial steam supply temperature monitoring unit T22, and an industrial steam supply flow monitoring unit Q22 before the steam consumption end 40, the state of the steam flow entering the steam consumption end 40 can be monitored, which serves as the basis for judging whether the safe operation of the steam consumption end 40 is met, thereby ensuring the safe and stable operation of the steam consumption end 40.

[0108] It should also be noted that the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus. Unless otherwise specified, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes that element.

[0109] The above are merely embodiments of this application and are not intended to limit the scope of this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the scope of the claims of this application.

Claims

1. An adjustable steam supply system for a steam turbine unit, characterized in that, include: The steam turbine unit includes a boiler, a high-pressure cylinder, an intermediate-pressure cylinder, a main steam pipeline, a cold-end steam reheat pipeline, and a steam supply pipeline. The steam supply pipeline includes an intermediate-pressure cylinder extraction steam pipeline and an industrial steam supply pipeline. The two ends of the main steam pipeline are connected to the reheat exhaust end of the boiler and the steam inlet end of the high-pressure cylinder, respectively. The two ends of the cold-end steam reheat pipeline are connected to the hot reheat steam end of the boiler and the exhaust end of the high-pressure cylinder, respectively. The two ends of the intermediate-pressure cylinder extraction steam pipeline are connected to the reheat exhaust end of the boiler and the extraction end of the intermediate-pressure cylinder, respectively. The two ends of the industrial steam supply pipeline are connected to the intermediate-pressure cylinder extraction steam pipeline and the input end of the steam consumption end, respectively. The steam-using end is connected to the output end of the industrial steam supply pipeline; The monitoring components include a regulating stage pressure monitoring unit and a high-pressure cylinder exhaust pressure monitoring unit. Both the regulating stage pressure monitoring unit and the high-pressure cylinder exhaust pressure monitoring unit are located inside the high-pressure cylinder and are used to monitor the operating status data of the high-pressure cylinder. The operating status data of the high-pressure cylinder includes: the regulating stage pressure of the high-pressure cylinder and the exhaust pressure of the high-pressure cylinder. The control component includes a pressure ratio calculation module, a working condition determination module, an operating strategy generation module, and a first instruction generation module. The pressure ratio calculation module is used to calculate the pressure ratio of the high-pressure cylinder regulating stage and the high-pressure cylinder exhaust pressure using formula (1); where K=P g / P ex (1), K represents the pressure ratio of the high-pressure cylinder; P g Indicates the pressure of the high-pressure cylinder regulating stage; P ex This indicates the exhaust pressure of the high-pressure cylinder; the operating condition determination module is used to determine the current operating condition based on the high-pressure cylinder pressure ratio and a preset pressure ratio range; the operating strategy generation module is used to match the current operating condition with a preset valve operating condition mapping table to determine the operating conditions of the valve assembly; wherein, the preset valve operating condition mapping table includes different operating conditions and their corresponding valve operating conditions; the first instruction generation module is used to generate control instructions under the current operating condition based on the operating conditions of the valve assembly. The valve assembly includes a first valve assembly and a second valve assembly. The first valve assembly is installed on the intermediate pressure cylinder extraction steam pipeline, and the second valve assembly is installed on the industrial steam supply pipeline. The first valve assembly is used to adjust the steam flow rate from the boiler to the intermediate pressure cylinder and the industrial steam supply pipeline when it receives a control command under the current operating conditions, so as to meet the steam flow rate requirements of the intermediate pressure cylinder under the current operating conditions. The second valve assembly is used to regulate the steam flow rate from the industrial steam supply line to the steam consumption end to meet the steam flow rate requirements of the steam consumption end under the current operating conditions.

2. The adjustable steam supply system for a steam turbine unit according to claim 1, characterized in that, The monitoring components also include: a high-pressure cylinder exhaust temperature monitoring unit; the control components also include: a high-pressure cylinder exhaust data processing module and a second instruction generation module; the operating status data of the high-pressure cylinder also includes: the high-pressure cylinder exhaust temperature; the high-pressure cylinder exhaust temperature monitoring unit is installed on the cold end reheat pipeline and is used to monitor the high-pressure cylinder exhaust temperature. The high-pressure cylinder exhaust data processing module is used to determine the switching rate of valve components corresponding to the current operating conditions based on the high-pressure cylinder exhaust temperature and the preset high-pressure cylinder exhaust temperature. The second instruction generation module is used to generate rate adjustment instructions based on the switching rate of the valve assembly; The first valve assembly is also used to control the flow rate of the steam discharged from the boiler to the intermediate pressure cylinder and the industrial steam supply line when a rate regulation command is received, so as to meet the steam flow requirements of the intermediate pressure cylinder under the current operating conditions.

3. The adjustable steam supply system for a steam turbine unit according to claim 2, characterized in that, The first valve assembly includes: a main electric regulating valve and an auxiliary electric regulating valve connected in parallel on the main reheat steam supply line; the second valve assembly includes: a manual shut-off regulating valve. The main electric regulating valve and the auxiliary electric regulating valve are used to adjust the steam flow from the boiler to the intermediate pressure cylinder and the industrial steam supply pipeline when a control command is received, so as to meet the steam flow requirements of the intermediate pressure cylinder under the current operating conditions. Manual shut-off valves are used to regulate the steam flow rate from the industrial steam supply line to the steam consumption end to meet the steam flow rate requirements of the steam consumption end under the current operating conditions.

4. The adjustable steam supply system for a steam turbine unit according to claim 1, characterized in that, The intermediate pressure cylinder extraction steam pipeline is also equipped with a first boiler exhaust steam pressure monitoring unit, a first boiler exhaust steam temperature monitoring unit, a second boiler exhaust steam pressure monitoring unit, and a second boiler exhaust steam temperature monitoring unit. The first boiler exhaust steam pressure monitoring unit and the first boiler exhaust steam temperature monitoring unit are both located at the front end of the first valve assembly, and the second boiler exhaust steam pressure monitoring unit and the second boiler exhaust steam temperature monitoring unit are both located at the rear end of the first valve assembly. The first boiler exhaust pressure monitoring unit is used to monitor the steam pressure of the steam discharged from the boiler; The first boiler exhaust temperature monitoring unit is used to monitor the steam temperature of the steam discharged from the boiler. The second boiler exhaust pressure monitoring unit is used to monitor the steam pressure of the steam discharged from the boiler and regulated by the first valve assembly; The second boiler exhaust temperature monitoring unit is used to monitor the steam temperature of the steam discharged from the boiler and regulated by the first valve assembly.

5. The adjustable steam supply system for a steam turbine unit according to claim 1, characterized in that, The second valve assembly also includes: a throttling orifice located on the industrial steam supply line; the throttling orifice is located at the front end of the manually shut-off regulating valve.

6. The adjustable steam supply system for a steam turbine unit according to claim 5, characterized in that, The second valve assembly also includes: a pneumatic check valve, an electric regulating valve, a pressure reducing valve, and a pneumatic quick-closing valve installed on the industrial steam supply pipeline; the pneumatic check valve, the electric regulating valve, the pressure reducing valve, and the pneumatic quick-closing valve are sequentially installed at the rear end of the manual shut-off regulating valve along the direction of steam discharge from the boiler to the steam consumption end.

7. The adjustable steam supply system for a steam turbine unit according to claim 6, characterized in that, Steam in the steam supply pipeline is regulated by a pneumatic quick-closing valve before being fed into the desuperheating water system.

8. The adjustable steam supply system for a steam turbine unit according to claim 7, characterized in that, The second valve assembly also includes: a safety valve installed on the industrial steam supply line; the safety valve is located at the rear end of the desuperheating water system.

9. The adjustable steam supply system for a steam turbine unit according to claim 8, characterized in that, The industrial steam supply pipeline is also equipped with an industrial steam supply pressure monitoring unit, an industrial steam supply temperature monitoring unit, and an industrial steam supply flow monitoring unit; all three units are located at the rear end of the safety valve. The industrial steam supply pressure monitoring unit is used to monitor the steam pressure of steam discharged from the industrial steam supply pipeline; The industrial steam supply temperature monitoring unit is used to monitor the steam temperature of the steam discharged from the industrial steam supply pipeline; The industrial steam supply flow monitoring unit is used to monitor the steam flow rate of steam discharged from the industrial steam supply pipeline.

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