Feed pump turbine steam admission pressure matching system for deep peak regulation and thermal generator set with feed pump turbine steam admission pressure matching system

Abstract

The utility model provides a feed pump turbine steam inlet pressure matching system for deep peak regulation, and belongs to the technical field of turbines. The feed pump turbine steam inlet pressure matching system for deep peak regulation comprises a steam injection pressure matcher, a high-pressure steam pipeline, a low-pressure steam pipeline and a mixed steam pipeline. The high-pressure steam pipeline is connected with the high-pressure steam input end of the steam injection pressure matcher and used for providing high-pressure exhaust steam of the main steam turbine for the steam injection pressure matcher. The low-pressure steam pipeline is connected with the low-pressure steam input end of the steam injection pressure matcher and used for providing medium-pressure exhaust steam of the main steam turbine for the steam injection pressure matcher. The steam injection pressure matcher is used for mixing the received high-pressure exhaust steam and medium-pressure exhaust steam to generate mixed steam; one end of the mixed steam pipeline is connected with the output end of the steam injection pressure matcher, and the other end of the mixed steam pipeline is connected with the steam input end of the water feed pump turbine and used for providing mixed steam for the water feed pump turbine.

Description

Technical Field

[0001] The utility model relates to the technical field of steam turbines, and particularly relates to a steam inlet pressure matching system for a feed water pump steam turbine for deep peak shaving and a thermal power generating unit. Background Art

[0002] A steam turbine is a prime mover that converts thermal energy into mechanical energy. The steam inlet of the feed water pump steam turbine is provided by extracting steam from the main steam turbine. The steam enters the feed water pump steam turbine through the main steam valve and regulating valve of the feed water pump steam turbine, expands and does work in the feed water pump steam turbine to drive the rotation of the shaft of the feed water pump in the thermal power plant, pressurize the feed water of the boiler, and thus realize the cycle of water steam in the thermal power generation system. The working environment of the feed water pump steam turbine is relatively harsh, and its speed changes with the power generation load of the main steam turbine, usually between 2500 - 6000 r / min. Therefore, when the main steam turbine operates under the deep peak shaving condition with sliding pressure, the steam extraction pressure of the main steam turbine decreases accordingly, resulting in a reduction in the steam volume entering the feed water pump steam turbine and thus a phenomenon of insufficient output, which affects the safe and stable operation of the main steam turbine under the deep peak shaving condition with sliding pressure.

[0003] For a general feed water pump steam turbine, it is provided with a low-pressure steam source and a high-pressure exhaust steam source. Under the normal operation and power generation condition of the main steam turbine, the low-pressure steam source can meet the output requirements of the feed water pump steam turbine; when the main steam turbine operates under the deep peak shaving condition with sliding pressure, the feed water pump steam turbine needs to switch to the high-pressure exhaust steam source condition for operation. During the process of switching from the low-pressure steam source to the high-pressure steam source, the speed of the feed water pump steam turbine often fluctuates greatly, affecting the stable operation of the main steam turbine and the operation safety of the feed water pump steam turbine. Summary of the Utility Model

[0004] To solve the above technical defects, the utility model provides a steam inlet pressure matching system for a feed water pump steam turbine for deep peak shaving. The steam inlet pressure matching system for a feed water pump steam turbine for deep peak shaving obtains the high-pressure exhaust steam and medium-pressure exhaust steam of the main steam turbine through a steam jet pressure matcher, fully mixes the obtained high-pressure exhaust steam and medium-pressure exhaust steam to obtain mixed steam, and inputs the mixed steam obtained by the steam jet pressure matcher into the feed water pump steam turbine under the deep peak shaving condition with sliding pressure of the main steam turbine, reduces the consumption of high-pressure steam, and avoids excessive speed fluctuation of the feed water pump steam turbine, which affects the stable operation of the main steam turbine and the feed water pump steam turbine.

[0005] The first aspect of the utility model provides a steam inlet pressure matching system for a feed water pump steam turbine for deep peak shaving, which is applied to a thermal power generating unit. The thermal power generating unit includes: a feed water pump steam turbine and a main steam turbine. The steam inlet pressure matching system for a feed water pump steam turbine for deep peak shaving includes: a steam jet pressure matcher, a high-pressure steam pipeline, a low-pressure steam pipeline, and a mixed steam pipeline;

[0006] The input end of the high-pressure steam pipeline is connected to the output end of the main steam turbine, and the output end of the high-pressure steam pipeline is connected to the high-pressure steam input end of the steam jet pressure matcher, for delivering the high-pressure exhaust steam of the main steam turbine to the steam jet pressure matcher;

[0007] The input end of the low-pressure steam pipeline is connected to the output end of the main steam turbine, and the output end of the low-pressure steam pipeline is connected to the low-pressure steam input end of the steam jet pressure matcher, for delivering the medium-pressure exhaust steam of the main steam turbine to the steam jet pressure matcher;

[0008] The steam jet pressure matcher is used to mix the received high-pressure exhaust steam and medium-pressure exhaust steam to generate mixed steam;

[0009] One end of the mixed steam pipeline is connected to the output end of the steam jet pressure matcher, and the other end of the mixed steam pipeline is connected to the steam input end of the boiler feed pump steam turbine, for delivering the mixed steam generated by the steam jet pressure matcher to the boiler feed pump steam turbine.

[0010] In the embodiment of the present invention, a pressure sensor is provided in the mixed steam pipeline, and the pressure sensor is used to monitor the pressure value of the mixed steam in the mixed steam pipeline.

[0011] In the embodiment of the present invention, a temperature sensor is provided in the mixed steam pipeline, and the temperature sensor is used to monitor the temperature value of the mixed steam in the mixed steam pipeline.

[0012] In the embodiment of the present invention, the steam inlet pressure matching system of the boiler feed pump steam turbine for deep peak shaving further includes: a drain pipeline;

[0013] The input end of the drain pipeline is connected to the output end of the steam jet pressure matcher, and the output end of the drain pipeline is connected to a drain flash tank. The drain pipeline is used to transport the drain generated in the mixed steam pipeline to the drain flash tank.

[0014] In the embodiment of the present invention, the drain pipeline includes: a first drain branch and a second drain branch;

[0015] The input end of the first drain branch is connected to the output end of the steam jet pressure matcher, and the output end of the first drain branch is connected to the drain flash tank. A drain valve is provided on the first drain branch;

[0016] The input end of the second drain branch is connected to the output end of the steam jet pressure matcher, and the output end of the first drain branch is connected to the drain flash tank. A drain stop valve and an automatic drainer are provided on the second drain branch, and the drain stop valves are respectively arranged at both ends of the automatic drainer.

[0017] In an embodiment of the present utility model, the low-pressure steam pipeline includes a low-pressure steam main path, a first low-pressure steam branch, and a second low-pressure steam branch;

[0018] The input end of the low-pressure steam main path is connected to the exhaust steam output end of the intermediate pressure cylinder of the main steam turbine, and the output end of the low-pressure steam main path is respectively connected to the input ends of the first low-pressure steam branch and the second low-pressure steam branch;

[0019] The output end of the first low-pressure steam branch is connected to the low-pressure steam input end of the steam jet pressure matcher, and the first low-pressure steam branch is used to convey the intermediate pressure exhaust steam of the main steam turbine to the steam jet pressure matcher;

[0020] The output end of the second low-pressure steam branch is connected to the steam input end of the boiler feed pump steam turbine, and the second low-pressure steam branch is used to convey the intermediate pressure exhaust steam of the main steam turbine to the boiler feed pump steam turbine.

[0021] In an embodiment of the present utility model, a high-pressure steam shut-off valve is provided in the high-pressure steam pipeline, a medium-pressure steam shut-off valve is provided in the first low-pressure steam branch, and a mixed steam shut-off valve is provided in the mixed steam pipeline.

[0022] In an embodiment of the present utility model, a medium-pressure check valve is provided in the second low-pressure steam branch.

[0023] In an embodiment of the present utility model, the boiler feed pump steam turbine includes a first boiler feed pump steam turbine and a second boiler feed pump steam turbine, and the steam jet pressure matcher includes a first steam jet pressure matcher and a second steam jet pressure matcher;

[0024] The low-pressure steam pipeline further includes a third low-pressure steam branch;

[0025] The input end of the first low-pressure steam branch is connected to the output end of the low-pressure steam main path, and the output end of the first low-pressure steam branch is connected to the low-pressure steam input end of the first steam jet pressure matcher;

[0026] The input end of the third low-pressure steam branch is connected to the output end of the low-pressure steam main path, and the output end of the third low-pressure steam branch is connected to the low-pressure steam input end of the second steam jet pressure matcher.

[0027] The second aspect of the present utility model provides a thermal power generating unit, including a main steam turbine, a boiler feed pump steam turbine, and a boiler feed pump. The thermal power generating unit further includes the above-mentioned steam inlet pressure matching system for the boiler feed pump steam turbine for deep peak shaving.

[0028] The steam inlet pressure matching system of the feed water pump steam turbine for deep peak shaving obtains the high-pressure exhaust steam and medium-pressure exhaust steam of the main steam turbine through a steam injection pressure matcher, fully mixes the obtained high-pressure exhaust steam and medium-pressure exhaust steam to obtain mixed steam, and in the sliding pressure deep peak shaving condition of the main steam turbine, inputs the mixed steam obtained by the steam injection pressure matcher into the feed water pump steam turbine, reduces the consumption of high-pressure steam, and avoids excessive speed fluctuations of the feed water pump steam turbine, which may affect the stable operation of the main steam turbine and the feed water pump steam turbine.

[0029] Other features and advantages of the technical solution of the present utility model will be described in detail in the following specific implementation section. Brief Description of the Drawings

[0030] The drawings described herein are used to provide a further understanding of the present utility model, form a part of the present utility model, and the schematic embodiments and descriptions thereof are used to explain the present utility model and do not constitute an improper limitation to the present utility model. In the drawings:

[0031] Figure 1 is a schematic structural diagram of the steam inlet pressure matching system of the feed water pump steam turbine for deep peak shaving provided in Embodiment 1 of the present utility model;

[0032] Figure 2 is a schematic structural diagram of the thermal power generating unit provided in Embodiment 2 of the utility model.

[0033] Description of the Reference Numerals

[0034] 10 - High-pressure steam pipeline, 11 - High-pressure steam shut-off valve, 12 - Steam injection pressure matcher, 121 - First steam injection pressure matcher, 122 - Second steam injection pressure matcher, 20 - Low-pressure steam pipeline, 201 - Low-pressure steam main path, 202 - First low-pressure steam branch, 203 - Second low-pressure steam branch, 204 - Third low-pressure steam branch, 21 - Four-way joint, 22 - Medium-pressure steam shut-off valve, 23 - Medium-pressure check valve, 30 - Mixed steam pipeline, 31 - Mixed steam shut-off valve, 32 - Pressure sensor, 33 - Temperature sensor, 40 - Drain pipeline, 41 - Drain valve, 42 - Drain stop valve, 43 - Automatic drainer, 50 - Exhaust steam pipeline, 60 - Feed water pump steam turbine, 61 - First feed water pump steam turbine, 62 - Second feed water pump steam turbine, 70 - Control module, 80 - High-pressure cylinder, 90 - Medium-pressure cylinder. Detailed Description of the Preferred Embodiments

[0035] In order to make the technical solutions and advantages in the embodiments of the present utility model clearer and more understandable, the exemplary embodiments of the present utility model are further described in detail below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present utility model, rather than an exhaustive list of all embodiments. It should be noted that, without conflict, the embodiments in the present utility model and the features in the embodiments can be combined with each other.

[0036] In the description of the present utility model, it should be understood that the orientation or positional relationship indicated by the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the present utility model and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the present utility model.

[0037] In addition, the terms "first" and "second" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include one or more of such features. In the description of the present utility model, the meaning of "a plurality" is at least two, such as two, three, etc., unless otherwise specifically and clearly defined.

[0038] In the present utility model, unless otherwise clearly specified and limited, terms such as "installation", "connection", "connection", "fixation", etc. should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or integrated; it can be a mechanical connection, an electrical connection, or communication with each other; it can be directly connected, or indirectly connected through an intermediate medium, and can be the connection inside two elements or the interaction relationship between two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present utility model can be understood according to specific circumstances.

[0039] A steam turbine is a prime mover that converts thermal energy into mechanical energy. The steam inlet of the boiler feed pump steam turbine is provided by extracting steam from the main steam turbine. The steam enters the boiler feed pump steam turbine through the main steam valve and regulating valve of the boiler feed pump steam turbine, causing it to expand and do work in the boiler feed pump steam turbine to drive the rotation of the shaft of the boiler feed pump in a thermal power plant, pressurize the feed water of the boiler, and thus realize the cycle of water steam in the thermal power generation system. The working environment of the boiler feed pump steam turbine is relatively harsh, and its rotational speed changes with the power generation load of the main steam turbine, usually between 2500 - 6000 r / min. Therefore, when the main steam turbine operates under the sliding pressure deep peak shaving condition, the extraction steam pressure of the main steam turbine decreases accordingly, resulting in a reduction in the steam volume entering the boiler feed pump steam turbine and thus causing a phenomenon of insufficient output, which affects the safe and stable operation of the main steam turbine under the sliding pressure deep peak shaving condition.

[0040] In the process of implementing the present utility model, the inventor found that for a general boiler feed pump steam turbine, it is provided with a low-pressure steam source and a high-pressure exhaust steam source. Under the normal power generation operating condition of the main steam turbine, the low-pressure steam source can meet the output requirement of the boiler feed pump steam turbine; when the main steam turbine operates under the sliding pressure deep peak shaving condition, the boiler feed pump steam turbine needs to switch to the high-pressure exhaust steam source operating condition. During the process of switching from the low-pressure steam source to the high-pressure steam source, it often causes a large fluctuation in the rotational speed of the boiler feed pump steam turbine, affecting the stable operation of the main steam turbine and the operating safety of the boiler feed pump steam turbine; because for the boiler feed pump steam turbine using high-quality high-pressure steam, the required high-pressure steam flow is much smaller than the low-pressure steam flow when the output is the same. At this time, the last-stage blades of the boiler feed pump steam turbine are in a blowing state, resulting in too high an exhaust temperature of the boiler feed pump steam turbine. It is necessary to spray water to cool the exhaust of the boiler feed pump steam turbine, which not only causes waste of high-quality steam but also has an impact of water erosion on the last-stage moving blades of the boiler feed pump steam turbine, thereby affecting the safe operation of the boiler feed pump steam turbine.

[0041] In view of the above problems, an inlet steam pressure matching system for a feedwater pump steam turbine for deep peak shaving is provided in an embodiment of the present utility model, which is applied to a thermal power generating unit. The thermal power generating unit includes: a feedwater pump steam turbine 60 and a main steam turbine. The inlet steam pressure matching system of the feedwater pump steam turbine 60 includes: a steam injection pressure matcher 12, a high-pressure steam pipeline 10, a low-pressure steam pipeline 20, a mixed steam pipeline 30, and a control module 70. The high-pressure steam pipeline 10 is connected to the high-pressure steam input end of the steam injection pressure matcher 12 and is used to provide the high-pressure exhaust steam of the main steam turbine for the steam injection pressure matcher 12. The low-pressure steam pipeline 20 is connected to the low-pressure steam input end of the steam injection pressure matcher 12 and is used to provide the intermediate-pressure exhaust steam of the main steam turbine for the steam injection pressure matcher 12. The control module 70 is connected to the steam injection pressure matcher 12 and is used to send a control instruction to the steam injection pressure matcher 12. The steam injection pressure matcher 12 mixes the received high-pressure exhaust steam and intermediate-pressure exhaust steam according to the control instruction to generate mixed steam. One end of the mixed steam pipeline 30 is connected to the output end of the steam injection pressure matcher 12, and the other end of the mixed steam pipeline 30 is connected to the steam input end of the feedwater pump steam turbine 60 and is used to provide mixed steam for the feedwater pump steam turbine 60. The inlet steam pressure matching system for the feedwater pump steam turbine for deep peak shaving obtains the high-pressure exhaust steam and intermediate-pressure exhaust steam of the main steam turbine through the steam injection pressure matcher 12, fully mixes the obtained high-pressure exhaust steam and intermediate-pressure exhaust steam to obtain mixed steam, and inputs the mixed steam obtained by the steam injection pressure matcher 12 into the feedwater pump steam turbine 60 under the deep peak shaving condition of the main steam turbine with sliding pressure, reduces the consumption of high-pressure steam, and avoids excessive speed fluctuations of the feedwater pump steam turbine 60, which may affect the stable operation of the main steam turbine and the feedwater pump steam turbine 60.

[0042] Figure 1 FIG. 4 is a schematic structural diagram of an inlet steam pressure matching system for a feedwater pump steam turbine for deep peak shaving provided in Embodiment 1 of the present utility model. As Figure 1 shown, an inlet steam pressure matching system for a feedwater pump steam turbine for deep peak shaving provided in this embodiment includes: a feedwater pump steam turbine 60 and a main steam turbine. The inlet steam pressure matching system of the feedwater pump steam turbine 60 includes: a steam injection pressure matcher 12, a high-pressure steam pipeline 10, a low-pressure steam pipeline 20, a mixed steam pipeline 30, and a control module 70;

[0043] The input end of the high-pressure steam pipeline 10 is connected to the output end of the main steam turbine, and the output end of the high-pressure steam pipeline 10 is connected to the high-pressure steam input end of the steam injection pressure matcher 12 and is used to transport the high-pressure exhaust steam of the main steam turbine to the steam injection pressure matcher 12;

[0044] The input end of the low-pressure steam pipeline 20 is connected to the output end of the main steam turbine, and the output end of the low-pressure steam pipeline 20 is connected to the low-pressure steam input end of the steam jet pressure matcher 12, for delivering the medium-pressure exhaust steam of the main steam turbine to the steam jet pressure matcher 12;

[0045] The control module 70 is connected to the steam jet pressure matcher 12, for sending control instructions to the steam jet pressure matcher 12;

[0046] The steam jet pressure matcher 12 is used for mixing the received high-pressure exhaust steam and medium-pressure exhaust steam according to the control instructions to generate mixed steam;

[0047] One end of the mixed steam pipeline 30 is connected to the output end of the steam jet pressure matcher 12, and the other end of the mixed steam pipeline 30 is connected to the steam input end of the boiler feed pump steam turbine 60, for delivering the mixed steam generated by the steam jet pressure matcher 12 to the boiler feed pump steam turbine 60.

[0048] Specifically, the input end of the high-pressure steam pipeline 10 is connected to the exhaust steam output end of the high-pressure cylinder 80 of the main steam turbine, for receiving the high-pressure exhaust steam of the main steam turbine, and the output end of the high-pressure steam pipeline 10 is connected to the high-pressure steam input end of the steam jet pressure matcher 12, and the high-pressure steam pipeline 10 is used for delivering the high-pressure exhaust steam of the main steam turbine to the steam jet pressure matcher 12.

[0049] The input end of the low-pressure steam pipeline 20 is connected to the medium-pressure cylinder 90 of the main steam turbine, for receiving the medium-pressure exhaust steam of the main steam turbine, and the output end of the low-pressure steam pipeline 20 is connected to the low-pressure steam input end of the steam jet pressure matcher 12, and the low-pressure steam pipeline 20 is used for delivering the medium-pressure exhaust steam of the main steam turbine to the steam jet pressure matcher 12.

[0050] The steam jet pressure matcher 12 is an electric steam jet pressure matcher 12. The electric steam jet pressure matcher 12 uses the received high-pressure exhaust steam as the jet steam source, draws the medium-pressure exhaust steam of the main steam turbine into the low-pressure steam pipeline 20, and the high-pressure exhaust steam and the medium-pressure exhaust steam are mixed under the action of the steam jet pressure matcher 12 to generate mixed steam for output to the boiler feed pump steam turbine 60.

[0051] The control module 70 is electrically connected to the electric steam jet pressure matcher 12, for sending control instructions to the electric steam jet pressure matcher 12. The electric steam jet pressure matcher 12 drives the motor of the steam jet pressure matcher 12 to rotate according to the control instructions, thereby controlling the flow rate and flow of the high-pressure exhaust steam flowing into the steam jet pressure matcher 12, and further ensuring the pressure and temperature of the required mixed steam.

[0052] Further, the control module 70 generates a control instruction based on the pressure and temperature of the mixed steam actually required.

[0053] The feed water pump steam turbine 60 also has an exhaust steam pipeline 50.

[0054] In this embodiment, a pressure sensor 32 and a temperature sensor 33 are further provided in the mixed steam pipeline 30;

[0055] The pressure sensor 32 is used to monitor the pressure value of the mixed steam in the mixed steam pipeline 30;

[0056] The temperature sensor 33 is used to monitor the temperature value of the mixed steam in the mixed steam pipeline 30.

[0057] In this embodiment, the pressure sensor 32 and the temperature sensor 33 are respectively connected to the control module 70;

[0058] The pressure sensor 32 is used to send the monitored pressure value of the mixed steam to the control module 70;

[0059] The temperature sensor 33 is used to send the monitored temperature value of the mixed steam to the control module 70;

[0060] The control module 70 generates the control instruction according to the received pressure value and temperature value of the mixed steam.

[0061] The control module 70 adjusts the control instruction according to the deviation between the monitored pressure value of the mixed steam and the actually required pressure value of the mixed steam and the deviation between the monitored temperature value of the mixed steam and the actually required temperature value of the mixed steam, obtains a new control instruction, and the steam injection pressure matcher 12 works according to the new control instruction.

[0062] In this embodiment, the feed water pump steam turbine inlet steam pressure matching system for deep peak shaving further includes: a drain pipeline 40;

[0063] The input end of the drain pipeline 40 is connected to the output end of the steam injection pressure matcher 12, the output end of the drain pipeline 40 is connected to the drain flash tank, and the drain pipeline 40 is used to transport the drain water generated in the mixed steam pipeline 30 to the drain flash tank.

[0064] In this embodiment, the drain pipeline 40 includes: a first drain branch and a second drain branch;

[0065] A drain valve 41 is provided on the first drain branch;

[0066] A steam trap shut-off valve 42 and a steam trap 43 are provided on the second steam drain branch. The steam trap 43 is arranged at both ends thereof respectively.

[0067] Specifically, the input end of the first steam drain branch is connected to the output end of the steam jet pressure matcher 12, the output end of the first steam drain branch is connected to a steam drain flash tank, and a steam trap valve 41 is provided on the first steam drain branch.

[0068] The input end of the second steam drain branch is connected to the output end of the steam jet pressure matcher 12, the output end of the first steam drain branch is connected to a steam drain flash tank. A steam trap shut-off valve 42 and a steam trap 43 are provided on the second steam drain branch. The steam trap shut-off valve 42 is arranged at both ends of the steam trap 43 respectively.

[0069] In this embodiment, the low-pressure steam pipeline 20 includes: a low-pressure steam main line 201, a first low-pressure steam branch line 202, and a second low-pressure steam branch line 203.

[0070] The input end of the low-pressure steam main line 201 is connected to the exhaust steam output end of the intermediate pressure cylinder 90 of the main steam turbine, and the output end of the low-pressure steam main line 201 is respectively connected to the input end of the first low-pressure steam branch line 202 and the input end of the second low-pressure steam branch line 203.

[0071] The output end of the first low-pressure steam branch line 202 is connected to the low-pressure steam input end of the steam jet pressure matcher 12, and the first low-pressure steam branch line 202 is used to convey the intermediate pressure exhaust steam of the main steam turbine to the steam jet pressure matcher 12.

[0072] The output end of the second low-pressure steam branch line 203 is connected to the steam input end of the boiler feed pump steam turbine 60, and the second low-pressure steam branch line 203 is used to convey the intermediate pressure exhaust steam of the main steam turbine to the boiler feed pump steam turbine 60.

[0073] In this embodiment, the low-pressure steam main line 201 is used to input the intermediate pressure exhaust steam of the intermediate pressure cylinder 90 of the main steam turbine.

[0074] The first low-pressure steam branch line 202 receives the intermediate pressure exhaust steam output from the low-pressure steam main line 201. The intermediate pressure exhaust steam is drawn into the steam jet pressure matcher 12 in the first low-pressure steam branch line 202 and mixed with the high-pressure exhaust steam to obtain mixed steam.

[0075] The second low-pressure steam branch line 203 receives the intermediate pressure exhaust steam output from the low-pressure steam main line 201. The intermediate pressure exhaust steam is input into the boiler feed pump steam turbine 60 through the second low-pressure steam branch line 203 to drive the boiler feed pump steam turbine 60 to do work.

[0076] In this embodiment, a high-pressure steam shut-off valve 11 is provided in the high-pressure steam pipeline 10, a medium-pressure steam shut-off valve 22 is provided in the first low-pressure steam branch 202, a medium-pressure check valve 23 is provided in the second low-pressure steam branch 203, and a mixed steam shut-off valve 31 is provided in the mixed steam pipeline 30.

[0077] Specifically, the high-pressure steam shut-off valve 11 is used to control the flow rate of the high-pressure exhaust steam in the high-pressure steam pipeline 10, the medium-pressure steam shut-off valve 22 is used to control the flow rate of the mixed steam flowing in the first low-pressure steam branch 202, and the mixed steam shut-off valve 31 is used to control the flow rate of the mixed steam flowing in the mixed steam pipeline 30.

[0078] The medium-pressure check valve 23 is used to prevent the medium-pressure exhaust steam from flowing back and returning to the medium-pressure cylinder 90 of the main steam turbine.

[0079] A feed water pump steam turbine inlet steam pressure matching method provided in this embodiment includes:

[0080] When the power generation load of the main steam turbine is less than the preset load value, the steam injection pressure matcher 12 generates mixed steam using the high-pressure exhaust steam and medium-pressure exhaust steam of the main steam turbine, and inputs the mixed steam generated by the steam injection pressure matcher 12 into the feed water pump steam turbine 60, and the feed water pump steam turbine 60 uses the input mixed steam to do work;

[0081] When the power generation load of the main steam turbine is greater than or equal to the preset load value, the feed water pump steam turbine 60 inputs the medium-pressure exhaust steam from the main steam turbine and uses the input medium-pressure exhaust steam to do work.

[0082] Specifically, the feed water pump steam turbine inlet steam pressure matching method is implemented based on the feed water pump steam turbine inlet steam matching system for deep peak shaving as described above, and the method is specifically as follows:

[0083] The preset load value is 40% THA. When the power generation load of the main steam turbine is greater than or equal to 40% THA and less than 100% THA, the steam flow required by the main steam turbine is 400 - 1000 t / h, and the feed water pump turbine 60 can drive the feed water pump to work normally. At this time, only the low-pressure steam pipeline 20 provides medium-pressure exhaust steam with a pressure of 0.35 - 1.0 MPa and a temperature of 300 - 350 °C as the steam source for the feed water pump turbine 60 to drive the feed water pump to do external work. When the power generation load of the main steam turbine is above 40% - 100% THA, the steam provided by the low-pressure steam pipeline 20 for the feed water pump turbine 60 can drive the feed water pump to meet the operating requirements of the main steam turbine. In this condition, the high-pressure steam shut-off valve 11 on the high-pressure steam pipeline 10 and the medium-pressure steam shut-off valve 22 on the low-pressure steam pipeline 20 are closed, and the mixed steam shut-off valve 31 of the mixed steam pipeline 30 and the electric steam injection pressure matcher 12 are opened. The mixed steam pipeline 30 and the electric steam injection pressure matcher 12 are in a hot standby state, and the drain of the mixed steam pipeline 30 is sent to the drain expansion tank for recovery through the drain pipeline 40.

[0084] When the power generation load of the main steam turbine is less than 40% THA, the steam flow required by the main steam turbine decreases to 400 t / h, and the steam pressure extracted from the main steam turbine by the low-pressure steam pipeline 20 is below 0.35 MPa, which cannot meet the system output requirements of the feed water pump turbine 60; when the power generation load of the main steam turbine is deeply adjusted below 40% THA, at this time, the mixed steam provided by the mixed steam pipeline 30 is switched to be used as the steam source for the feed water pump turbine 60 to drive the feed water pump to do external work; the mixed steam is composed of high-pressure exhaust steam with a pressure of 1.4 - 1.8 MPa and a temperature of 290 - 330 °C in the high-pressure steam pipeline 10 and medium-pressure exhaust steam with a pressure of 0.3 - 0.38 MPa and a temperature of 300 - 340 °C in the low-pressure steam pipeline 20. The electric steam injection pressure matcher 12 controls the steam pressures of the power steam source (the high-pressure steam pipeline 10) and the entrained steam source (the low-pressure steam pipeline 20) through the control module 70 to form a mixed steam pressure controlled between 0.5 - 0.7 MPa, which can meet the working requirements of a single feed water pump turbine 60.

[0085] Embodiment 2

[0086] This embodiment is basically the same as Embodiment 1, and the difference is that Figure 2 is a schematic structural diagram of a thermal power generation unit provided by Embodiment 2 of the utility model; as Figure 2 shown. The thermal power generation unit includes two feed water pump turbines 60 and two feed water pumps, namely the first feed water pump turbine 61, the first feed water pump, the second feed water pump turbine 62, and the second feed water pump.

[0087] The steam supply sources for the steam admission pressure matching system of the boiler feed pump turbine for deep peak shaving are respectively provided for two boiler feed pump turbines 60.

[0088] The low-pressure steam pipeline 20 of the steam admission pressure matching system of the boiler feed pump turbine for deep peak shaving includes: a low-pressure steam main path 201, a first low-pressure steam branch 202, a second low-pressure steam branch 203, and a third low-pressure steam branch 204, wherein the second low-pressure steam branch 203 includes a first output end and a second output end; the input end of the low-pressure steam main path 201 is connected to the exhaust output end of the intermediate-pressure cylinder 90 of the main steam turbine, and the output end of the low-pressure steam main path 201 is respectively connected to the input ends of the first low-pressure steam branch 202, the second low-pressure steam branch 203, and the third low-pressure steam branch 204 through a four-way joint 21.

[0089] The high-pressure steam pipeline 10 of the steam admission pressure matching system of the boiler feed pump turbine for deep peak shaving includes: a high-pressure steam main path, a first high-pressure steam branch, and a second high-pressure steam branch; the input end of the high-pressure steam main path is connected to the exhaust output end of the high-pressure cylinder 80 of the main steam turbine, and the output end of the high-pressure steam main path is respectively connected to the input ends of the first high-pressure steam branch and the second high-pressure steam branch.

[0090] The mixed steam pipeline 30 of the steam admission pressure matching system of the boiler feed pump turbine for deep peak shaving includes: a first mixed steam pipeline 30 and a second mixed steam pipeline 30;

[0091] The steam admission pressure matching system of the boiler feed pump turbine for deep peak shaving includes: a first steam injection pressure matcher 121 and a second steam injection pressure matcher 122;

[0092] The connection relationship between the steam admission pressure matching system of the boiler feed pump turbine 60 and the two boiler feed pump turbines 60 is specifically as follows:

[0093] The high-pressure input end of the first steam injection pressure matcher 121 is connected to the output end of the first high-pressure steam branch, the low-pressure input end of the first steam injection pressure matcher 121 is connected to the output end of the first low-pressure steam branch 202, the output end of the first steam injection pressure matcher 121 is connected to the input end of the first mixed steam pipeline 30, and the output end of the first mixed steam pipeline 30 is connected to the steam input end of the first boiler feed pump turbine 61.

[0094] The high-pressure input end of the second steam jet pressure matcher 122 is connected to the output end of the second high-pressure steam branch, the low-pressure input end of the second steam jet pressure matcher 122 is connected to the output end of the third low-pressure steam branch 204, the output end of the second steam jet pressure matcher 122 is connected to the input end of the second mixed steam pipeline 30, and the output end of the second mixed steam pipeline 30 is connected to the steam input end of the second boiler feed pump turbine 62.

[0095] The first output end of the second low-pressure steam branch 203 is further connected to the steam input end of the first boiler feed pump turbine 61, and the second output end of the second low-pressure steam branch 203 is further connected to the steam input end of the second boiler feed pump turbine 62.

[0096] The first steam jet pressure matcher 121 is used to provide a steam source for the first boiler feed pump turbine 61, and the second steam jet pressure matcher 122 is used to provide a steam source for the second boiler feed pump turbine 62.

[0097] This embodiment further provides a method for matching the inlet steam pressure of a boiler feed pump turbine, including:

[0098] When the power generation load of the main steam turbine is less than a preset load value, the steam jet pressure matcher 12 uses the high-pressure exhaust steam and the intermediate-pressure exhaust steam of the main steam turbine to generate mixed steam, and inputs the mixed steam generated by the steam jet pressure matcher 12 into the boiler feed pump turbine 60, and the boiler feed pump turbine 60 uses the input mixed steam to do work;

[0099] When the power generation load of the main steam turbine is greater than or equal to the preset load value, the boiler feed pump turbine 60 inputs the intermediate-pressure exhaust steam from the main steam turbine and uses the input intermediate-pressure exhaust steam to do work.

[0100] Specifically, the method for matching the inlet steam pressure of the boiler feed pump turbine 60 is implemented based on the above-mentioned inlet steam matching system of the boiler feed pump turbine 60, and the method is specifically as follows:

[0101] The preset load value is 40% THA. When the power generation load of the main steam turbine is greater than or equal to 40% THA and less than 100% THA, the required steam flow of the main steam turbine is 400 - 1000 t / h. The first feed water pump turbine 61 drives the first feed water pump to work, and at the same time, the second feed water pump turbine 62 drives the second feed water pump to work. At this time, only the low-pressure steam pipeline 20 provides medium-pressure exhaust steam with a pressure of 0.35 - 1.0 MPa and a temperature of 300 - 350 °C as the steam source for the feed water pump turbine 60 to drive the feed water pump to do external work. When the power generation load of the main steam turbine is above 40% - 100% THA, the steam provided by the low-pressure steam pipeline 20 for the feed water pump turbine 60 can drive the feed water pump to meet the operation requirements of the main steam turbine. In this condition, the high-pressure steam shut-off valve 11 on the high-pressure steam pipeline 10 and the medium-pressure steam shut-off valve 22 on the low-pressure steam pipeline 20 are closed, and the mixed steam shut-off valve 31 of the mixed steam pipeline 30 and the electric steam injection pressure matcher 12 are opened. The mixed steam pipeline 30 and the electric steam injection pressure matcher 12 are in a hot standby state, and the drain of the mixed steam pipeline 30 is sent to the drain expansion vessel for recovery through the drain pipeline 40.

[0102] When the power generation load of the main steam turbine is less than 40% THA, since the required steam flow of the main steam turbine decreases to 400 t / h, to prevent the phenomenon of cavitation in the feed water pump, only one feed water pump turbine 60 needs to work at this time, and the first feed water pump turbine 61 and the second feed water pump turbine 62 system can be switched through the four-way valve 21. Taking the case where only the first feed water pump turbine 61 operates when the power generation load of the main steam turbine is deeply adjusted below 40% THA: The steam pressure extracted from the main steam turbine by the low-pressure steam pipeline 20 is below 0.35 MPa, which cannot meet the output requirement of the feed water pump turbine 60 system; when the power generation load of the main steam turbine is deeply adjusted below 40% THA, at this time, the mixed steam provided by the mixed steam pipeline 30 is switched to be used as the steam source for the feed water pump turbine 60 to drive the feed water pump to do external work; the mixed steam is composed of high-pressure exhaust steam with a pressure of 1.4 - 1.8 MPa and a temperature of 290 - 330 °C in the high-pressure steam pipeline 10 and medium-pressure exhaust steam with a pressure of 0.3 - 0.38 MPa and a temperature of 300 - 340 °C in the low-pressure steam pipeline 20. The electric steam injection pressure matcher 12 controls the steam pressures of the power steam source (matching the high-pressure steam pipeline 10) and the induced steam source (the low-pressure steam pipeline 20) through the control module 70 to form a mixed steam pressure controlled between 0.5 - 0.7 MPa, which can meet the working requirements of a single feed water pump turbine 60.

[0103] Although the preferred embodiments of the present utility model have been described, those skilled in the art can make additional changes and modifications to these embodiments once they know the basic creative concept. Therefore, the appended claims are intended to be construed as including the preferred embodiments and all changes and modifications that fall within the scope of the present utility model.

[0104] Obviously, those skilled in the art can make various changes and modifications to the present utility model without departing from the spirit and scope of the present utility model. Thus, if these modifications and variations of the present utility model fall within the scope of the claims of the present utility model and their equivalent technologies, the present utility model also intends to include these modifications and variations.

[0105] Although the preferred embodiments of the present utility model have been described, those skilled in the art can make additional changes and modifications to these embodiments once they know the basic creative concept. Therefore, the appended claims are intended to be construed as including the preferred embodiments and all changes and modifications that fall within the scope of the present utility model.

[0106] Obviously, those skilled in the art can make various changes and modifications to the present utility model without departing from the spirit and scope of the present utility model. Thus, if these modifications and variations of the present utility model fall within the scope of the claims of the present utility model and their equivalent technologies, the present utility model also intends to include these modifications and variations.

[0107] The optional embodiments of the present utility model have been described in detail above in conjunction with the accompanying drawings. However, the embodiments of the present utility model are not limited to the specific details in the above embodiments. Within the technical concept scope of the embodiments of the present utility model, various simple variations can be made to the technical solutions of the embodiments of the present utility model, and these simple variations all fall within the protection scope of the embodiments of the present utility model. Additionally, it should be noted that in the above specific embodiments, the various specific technical features described can be combined in any appropriate manner without contradiction, as long as the combination does not violate the idea of the embodiments of the present utility model, and it should equally be regarded as the content disclosed by the embodiments of the present utility model.

Claims

1. A steam inlet pressure matching system for a feedwater pump steam turbine used for deep peak shaving, which is applied to a thermal power generating unit. The thermal power generating unit includes: The feedwater turbine and the main steam turbine are characterized in that the steam inlet pressure matching system for the feedwater turbine used for deep peak shaving includes: a steam jet pressure matcher, a high-pressure steam pipeline, a low-pressure steam pipeline, and a mixed steam pipeline; The input end of the high-pressure steam pipeline is connected to the output end of the main steam turbine, and the output end of the high-pressure steam pipeline is connected to the high-pressure steam input end of the steam jet pressure matcher, for transporting the high-pressure exhaust steam of the main steam turbine to the steam jet pressure matcher; The input end of the low-pressure steam pipeline is connected to the output end of the main steam turbine, and the output end of the low-pressure steam pipeline is connected to the low-pressure steam input end of the steam jet pressure matcher, for transporting the medium-pressure exhaust steam of the main steam turbine to the steam jet pressure matcher; The steam jet pressure matcher is used to mix the received high-pressure exhaust steam and medium-pressure exhaust steam to generate mixed steam; One end of the mixed steam pipeline is connected to the output end of the steam jet pressure matcher, and the other end of the mixed steam pipeline is connected to the steam input end of the feedwater turbine, for transporting the mixed steam generated by the steam jet pressure matcher to the feedwater turbine.

2. The steam inlet pressure matching system for the feed water pump steam turbine used for deep peak shaving according to claim 1, wherein A pressure sensor is provided in the mixed steam pipeline, and the pressure sensor is used to monitor the pressure value of the mixed steam in the mixed steam pipeline.

3. The steam inlet pressure matching system for a feedwater pump steam turbine used for deep peak shaving according to claim 1, wherein A temperature sensor is provided in the mixed steam pipeline, and the temperature sensor is used to monitor the temperature value of the mixed steam in the mixed steam pipeline.

4. The steam inlet pressure matching system for a feedwater pump steam turbine used for deep peak shaving according to claim 1, wherein, The steam inlet pressure matching system for the feedwater turbine used for deep peak shaving further includes: a drain pipeline; The input end of the drain pipeline is connected to the output end of the steam jet pressure matcher, and the output end of the drain pipeline is connected to a drain flash tank. The drain pipeline is used to transport the drain generated in the mixed steam pipeline to the drain flash tank.

5. The steam inlet pressure matching system for a feedwater pump steam turbine used for deep peak shaving according to claim 4, wherein, The drain pipeline includes: a first drain branch and a second drain branch; The input end of the first drain branch is connected to the output end of the steam jet pressure matcher, and the output end of the first drain branch is connected to the drain flash tank. A drain valve is provided on the first drain branch; The input end of the second drain branch is connected to the output end of the steam jet pressure matcher, and the output end of the first drain branch is connected to the drain flash tank. A drain stop valve and an automatic drainer are provided on the second drain branch, and the drain stop valves are respectively arranged at both ends of the automatic drainer.

6. The steam inlet pressure matching system for a feedwater pump steam turbine used for deep peak shaving according to claim 1, wherein The low-pressure steam pipeline includes: a low-pressure steam main path, a first low-pressure steam branch, and a second low-pressure steam branch; The input end of the low-pressure steam main path is connected to the medium-pressure cylinder exhaust output end of the main steam turbine, and the output end of the low-pressure steam main path is respectively connected to the input end of the first low-pressure steam branch and the input end of the second low-pressure steam branch; The output end of the first low-pressure steam branch is connected to the low-pressure steam input end of the steam jet pressure matcher, and the first low-pressure steam branch is used to transport the medium-pressure exhaust steam of the main steam turbine to the steam jet pressure matcher; The output end of the second low-pressure steam branch is connected to the steam input end of the feedwater turbine, and the second low-pressure steam branch is used to transport the medium-pressure exhaust steam of the main steam turbine to the feedwater turbine.

7. The steam inlet pressure matching system for a feedwater pump steam turbine used for deep peak shaving according to claim 6, characterized in that, A high-pressure steam shut-off valve is provided in the high-pressure steam pipeline, a medium-pressure steam shut-off valve is provided in the first low-pressure steam branch, and a mixed-steam shut-off valve is provided in the mixed-steam pipeline.

8. The steam inlet pressure matching system for a feedwater pump steam turbine used for deep peak shaving according to claim 6, characterized in that, A medium-pressure check valve is provided in the second low-pressure steam branch.

9. The steam inlet pressure matching system for a feedwater pump steam turbine used for deep peak shaving according to claim 6, wherein, The feedwater turbine includes: a first feedwater turbine and a second feedwater turbine, and the steam jet pressure matcher includes: a first steam jet pressure matcher and a second steam jet pressure matcher; The low-pressure steam pipeline further includes: a third low-pressure steam branch; The input end of the first low-pressure steam branch is connected to the output end of the low-pressure steam main pipeline, and the output end of the first low-pressure steam branch is connected to the low-pressure steam input end of the first steam jet pressure matcher; The input end of the third low-pressure steam branch is connected to the output end of the low-pressure steam main pipeline, and the output end of the third low-pressure steam branch is connected to the low-pressure steam input end of the second steam jet pressure matcher.

10. A thermal power generating unit, comprising: A main steam turbine, a feedwater turbine and a feedwater pump, characterized in that the thermal power generating set further includes a feedwater turbine inlet steam pressure matching system for deep peak shaving as described in any one of claims 1-9.

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