Energy-saving system for warm state drain system of steam turbine and control method thereof

Abstract

The application discloses a steam turbine warm state drain system energy-saving system and a control method thereof, which comprises a main steam pipeline, a high-pressure cylinder, a reheated steam pipeline, a medium-pressure cylinder, a low-pressure steam pipeline and a low-pressure cylinder; the main steam pipeline is connected with the inlet of the high-pressure cylinder, the reheated steam pipeline is connected with the inlet of the medium-pressure cylinder, and the low-pressure steam pipeline is connected with the inlet of the low-pressure cylinder; the main steam pipeline is connected with a steam drain pipeline; and a drain valve, a pressure gauge and a temperature gauge are arranged on the steam drain pipeline. The system and the control method thereof can automatically close the drain valve under the warm state start of the unit, reduce the steam consumption of the steam turbine in the warm state start process of the unit to the maximum extent, and save the start time of the unit.

Description

Technical Field

[0001] This invention belongs to the field of energy saving during steam turbine operation and startup, and relates to an energy-saving system and control method for a steam turbine hot-state condensate drainage system. Background Technology

[0002] During turbine startup, the turbine and its steam pipelines require thorough drainage. However, the turbine drainage system is closed uniformly based on grid connection and load points, and cannot be individually automatically closed in a closed-loop manner according to the actual unit status. Manual operation of individual pipeline valves is required based on the drainage temperature. When the unit starts in a warm state, the steam pipelines do not require prolonged drainage due to the insulation layer. Therefore, the steam pipeline drainage can be closed in advance, reducing startup steam consumption and saving startup time. Thus, closing the drainage system valves in advance during a warm-state startup offers significant energy savings. However, current technology, which uses the turbine load-based opening and closing logic for steam pipeline and main drainage pipeline valves, cannot automatically close individual drainage valves during a warm-state startup. Summary of the Invention

[0003] The purpose of this invention is to overcome the shortcomings of the prior art and provide an energy-saving system and control method for a steam turbine hot-state condensate drain system. This system and control method can automatically close the condensate drain valves during the unit's hot-state startup, thereby minimizing the steam consumption of the steam turbine during the hot-state startup process and saving the unit's startup time.

[0004] To achieve the above objectives, this invention discloses an energy-saving system for a steam turbine hot-state condensate drainage system, comprising a main steam pipeline, a high-pressure cylinder, a reheat steam pipeline, an intermediate-pressure cylinder, a low-pressure steam pipeline, and a low-pressure cylinder;

[0005] The main steam pipeline is connected to the inlet of the high-pressure cylinder, the reheat steam pipeline is connected to the inlet of the intermediate-pressure cylinder, and the low-pressure steam pipeline is connected to the inlet of the low-pressure cylinder. The main steam pipeline is connected to a steam condensate drain pipe, which is equipped with a condensate drain valve, a pressure gauge, and a temperature gauge.

[0006] A further improvement of the energy-saving system of the steam turbine hot-state condensate drainage system described in this invention is as follows:

[0007] Furthermore, it also includes a generator, with the generator, high-pressure cylinder, intermediate-pressure cylinder, and low-pressure cylinder arranged coaxially.

[0008] Furthermore, it also includes a controller, which is connected to a drain valve, a pressure gauge, and a temperature gauge.

[0009] Furthermore, a first condensate drain pipe is provided on the reheat steam pipe.

[0010] Furthermore, the first drainage pipe is equipped with a first valve, a first pressure gauge, and a first thermometer.

[0011] Furthermore, a second condensate drain pipe is provided on the low-pressure steam pipe.

[0012] Furthermore, the second drainage pipe is equipped with a second valve, a second pressure gauge, and a second thermometer.

[0013] Furthermore, the controller includes a subtraction block, a temperature calculation function module, a subtraction block, an adder, a preset temperature input terminal, a first selection block, a water valve open status input terminal, a first AND block, a medium-pressure rotor center temperature input terminal, a temperature limit input terminal, a second selection block, a second AND block, a drain independent control loop input terminal, a third AND block, and a drain valve close command output terminal.

[0014] The output of the thermometer is connected to the input of the subtraction block. The output of the pressure gauge is connected to the input of the subtraction block via the temperature calculation function module. The output of the adder is connected to the input of the preset temperature input and the first selection block. The input of the drain valve open state and the output of the first selection block are connected to the input of the first AND block. The input of the medium-pressure rotor center temperature and the temperature limit input are connected to the input of the second selection block. The output of the second selection block and the output of the first AND block are connected to the input of the second AND block. The output of the second AND block and the input of the drain independent control loop are connected to the input of the third AND block. The output of the third AND block is connected to the drain valve close command output.

[0015] This invention discloses a control method for an energy-saving system of a steam turbine hot-state condensate drainage system, comprising the following steps:

[0016] Input the pressure value P measured by the pressure gauge into the temperature calculation function block to calculate the saturation temperature T of the steam at that pressure. st Compare the temperature T measured by the thermometer with T st The difference is calculated and then input into the first selection block for comparison with 50℃. If it is greater than 50℃, an output signal is sent to the first selection block. At the same time, when the drain valve is in the open state, the drain valve outputs an open feedback state trigger signal to the first selection block, and the first selection block triggers the signal. Otherwise, the first selection block does not trigger the signal.

[0017] The center temperature T of the intermediate-pressure rotor was measured at a measuring point on the turbine body. C And input it into the second major block, along with the preset turbine temperature determination temperature T. W Comparison, when T C Greater than T WIf the unit is in a steady-state startup process, the second major block will be triggered; otherwise, the second major block will not be triggered. When the second major block is triggered, it will be sent to the second major block. When both the first and second major blocks are triggered, the second major block will be triggered and sent to the third major block.

[0018] When the independent control loop for the condensate drain is engaged, and the second block trigger signal is triggered, a command to close the condensate drain valve is output, causing the condensate drain valve to close.

[0019] A further improvement of the control method for the energy-saving system of the steam turbine hot-state condensate drainage system described in this invention lies in:

[0020] Furthermore, it also includes a generator, with the generator, high-pressure cylinder, intermediate-pressure cylinder, and low-pressure cylinder arranged coaxially.

[0021] The present invention has the following beneficial effects:

[0022] The energy-saving system and control method for the steam turbine hot-state condensate drain system described in this invention, when the condensate drain pipe has been fully drained, promptly closes the condensate drain valve on the main steam pipeline to avoid waste and loss of high-quality superheated steam. This helps improve the utilization rate of superheated steam during unit startup and increases startup efficiency. Thus, the condensate drain valve is automatically closed during the unit's hot-state startup, minimizing turbine steam consumption and saving startup time. It should be noted that this invention abandons the traditional load-based condensate drain switch control method; instead, it allows for independent on / off operation of the condensate drain valve in the steam turbine condensate drain pipe through an independent control loop. Attached Figure Description

[0023] The accompanying drawings, which form part of this specification, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an undue limitation of the invention. In the drawings:

[0024] Figure 1 This is a structural diagram of the present invention;

[0025] Figure 2 This is a schematic diagram of the controller in this invention.

[0026] Among them, 1 is the main steam pipeline, 2 is the reheat steam pipeline, 3 is the low-pressure steam pipeline, 4 is the high-pressure cylinder, 5 is the medium-pressure cylinder, 6 is the low-pressure cylinder, 7 is the steam drain pipeline, 8 is the drain valve, 9 is the pressure gauge, and 10 is the temperature gauge. Detailed Implementation

[0027] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0028] In the description of this invention, it should be understood that the terms "comprising" and "including" indicate the presence of the described features, integrals, steps, operations, elements and / or components, but do not exclude the presence or addition of one or more other features, integrals, steps, operations, elements, components and / or collections thereof.

[0029] It should also be understood that the terminology used in this specification is for the purpose of describing particular embodiments only and is not intended to limit the invention. As used in this specification and the appended claims, the singular forms “a,” “an,” and “the” are intended to include the plural forms unless the context clearly indicates otherwise.

[0030] It should also be further understood that the term "and / or" as used in this specification and the appended claims refers to any combination and all possible combinations of one or more of the associated listed items, and includes such combinations. For example, A and / or B can represent three cases: A alone, A and B simultaneously, and B alone. Additionally, the character " / " in this invention generally indicates that the preceding and following objects have an "or" relationship.

[0031] It should be understood that although terms such as first, second, third, etc., may be used in the embodiments of the present invention to describe the preset range, these preset ranges should not be limited to these terms. These terms are only used to distinguish the preset ranges from one another. For example, without departing from the scope of the embodiments of the present invention, the first preset range may also be referred to as the second preset range, and similarly, the second preset range may also be referred to as the first preset range.

[0032] Depending on the context, the word "if" as used here can be interpreted as "when," "when," "in response to determination," or "in response to detection." Similarly, depending on the context, the phrase "if determination" or "if detection (of the stated condition or event)" can be interpreted as "when determination," "in response to determination," "when detection (of the stated condition or event)," or "in response to detection (of the stated condition or event)."

[0033] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. The components of the embodiments of the present invention described and shown in the accompanying drawings can generally be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

[0034] The accompanying drawings illustrate various structural schematic diagrams according to embodiments disclosed in this invention. These drawings are not to scale, and some details have been enlarged for clarity, and some details may have been omitted. The shapes of the various regions and layers shown in the drawings, as well as their relative sizes and positional relationships, are merely exemplary and may deviate from reality due to manufacturing tolerances or technical limitations. Furthermore, those skilled in the art can design regions / layers with different shapes, sizes, and relative positions as needed.

[0035] Example 1

[0036] refer to Figure 1 The steam turbine hot-state condensate drain system energy-saving system of the present invention includes a controller, a main steam pipe 1, a reheat steam pipe 2, a low-pressure steam pipe 3, a high-pressure cylinder 4, a medium-pressure cylinder 5, a low-pressure cylinder 6, a steam condensate drain pipe 7, a condensate drain valve 8, a pressure gauge 9, and a temperature gauge 10.

[0037] The main steam pipe 1 is connected to the inlet of the high-pressure cylinder 4, the reheat steam pipe 2 is connected to the inlet of the intermediate-pressure cylinder 5, and the low-pressure steam pipe 3 is connected to the inlet of the low-pressure cylinder 6. The generator, high-pressure cylinder 4, intermediate-pressure cylinder 5 and low-pressure cylinder 6 are arranged coaxially. The main steam pipe 1 is connected to a steam drain pipe 7, and the steam drain pipe 7 is equipped with a drain valve 8, a pressure gauge 9 and a temperature gauge 10.

[0038] The controller is connected to the drain valve 8, pressure gauge 9 and temperature gauge 10.

[0039] In one embodiment of the present invention, a first condensate drain pipe is provided on the reheat steam pipe 2.

[0040] In one embodiment of the present invention, the first drainage pipe is provided with a first valve, a first pressure gauge and a first thermometer.

[0041] In one embodiment of the present invention, a second condensate drain pipe is provided on the low-pressure steam pipe 3.

[0042] In one embodiment of the present invention, the second drainage pipe is provided with a second valve, a second pressure gauge and a second thermometer.

[0043] As one embodiment of the present invention, reference Figure 2 The controller includes a subtraction block, a temperature calculation function module, a subtraction block, an adder, a preset temperature input terminal, a first selection block, a water valve open status input terminal, a first AND block, a medium-pressure rotor center temperature input terminal, a temperature limit input terminal, a second selection block, a second AND block, a drain independent control loop input terminal, a third AND block, and a drain valve close command output terminal.

[0044] The output of thermometer 10 is connected to the input of the subtraction block. The output of pressure gauge 9 is connected to the input of the subtraction block via the temperature calculation function module. The output of the adder, the preset temperature input, and the input of the first selection block are connected. The open state input of the drain valve and the output of the first selection block are connected to the input of the first AND block. The center temperature input of the medium-pressure rotor and the temperature limit input are connected to the input of the second selection block. The output of the second selection block and the output of the first AND block are connected to the input of the second AND block. The output of the second AND block and the input of the independent drain control loop are connected to the input of the third AND block. The output of the third AND block is connected to the drain valve close command output.

[0045] Example 2

[0046] This invention discloses a control method for an energy-saving system of a steam turbine hot-state condensate system. The energy-saving system includes a controller, a main steam pipeline 1, a reheat steam pipeline 2, a low-pressure steam pipeline 3, a high-pressure cylinder 4, an intermediate-pressure cylinder 5, a low-pressure cylinder 6, a steam condensate pipeline 7, a condensate valve 8, a pressure gauge 9, and a thermometer 10. The controller includes a subtraction block, a temperature calculation function module, a subtraction block, an adder, a preset temperature input terminal, a first selection block, a water valve open state input terminal, a first AND block, an intermediate-pressure rotor center temperature input terminal, a temperature limit input terminal, a second selection block, a second AND block, a condensate independent control loop input terminal, a third AND block, and a condensate valve close command output terminal. The specific connection relationship is shown in Embodiment 1.

[0047] Specifically, the control method for the energy-saving system of the steam turbine hot-state condensate drainage system includes the following steps:

[0048] Input the pressure value P measured by pressure gauge 9 into the temperature calculation function block to calculate the saturation temperature T of the steam at that pressure. st The temperature T measured by thermometer 10 is compared with T... stThe difference is calculated and then input into the first selection block for comparison with 50°C. If the difference is greater than 50°C, an output signal is sent to the first selection block. At the same time, when the drain valve 8 is in the open state, the drain valve 8 outputs an open feedback state trigger signal to the first selection block, at which time the first selection block triggers the signal; otherwise, the first selection block does not trigger the signal.

[0049] The center temperature T of the intermediate-pressure rotor was measured at a measuring point on the turbine body. C And input it into the second major block, along with the preset turbine temperature determination temperature T. W Comparison, when T C Greater than T W If the unit is in a steady-state startup process, the second major block will be triggered; otherwise, the second major block will not be triggered. When the second major block is triggered, it will be sent to the second AND block. When both the first AND block and the second major block are triggered, the second AND block will be triggered and sent to the third AND block.

[0050] When the independent control loop for condensate drainage is activated, and the second block trigger signal is received, a command to close the condensate drainage valve is output, causing the condensate drainage valve 8 to close.

[0051] Example 3

[0052] A computer device includes a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, it implements the steps of a control method for an energy-saving system of a steam turbine hot-state drainage system. The memory may include main memory, such as high-speed random access memory (RAM), and may also include non-volatile memory, such as at least one disk storage device. The processor, network interface, and memory are interconnected via an internal bus, which may be an industry-standard architecture bus, a peripheral component interconnection standard bus, or an extended industry-standard architecture bus. The bus can be categorized as an address bus, data bus, and control bus. The memory stores the program; specifically, the program may include program code, which includes computer operation instructions. The memory may include main memory and non-volatile memory, and provides instructions and data to the processor.

[0053] Example 4

[0054] A computer-readable storage medium stores a computer program that, when executed by a processor, implements the steps of a control method for an energy-saving system of a steam turbine hot-state condensate drainage system. Specifically, the computer-readable storage medium includes, but is not limited to, volatile memory and / or non-volatile memory. The volatile memory may include random access memory and / or cache memory, etc. The non-volatile memory may include read-only memory, hard disk, flash memory, optical disk, magnetic disk, etc.

[0055] Those skilled in the art will understand that embodiments of this application can be provided as methods, systems, or computer program products. Therefore, this application can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, this application can take the form of a computer program product implemented on one or more computer-usable storage media containing computer-usable program code.

[0056] This application is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of this application. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, generate instructions for implementing the flowchart... Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0057] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means, which are implemented in a process Figure 1 One or more processes and / or boxes Figure 1 The function specified in one or more boxes.

[0058] These computer program instructions may also be loaded onto a computer or other programmable data processing equipment to cause a series of operational steps to be performed on the computer or other programmable equipment to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable equipment for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The steps of the function specified in one or more boxes.

[0059] Other embodiments of the invention will readily occur to those skilled in the art upon consideration of the specification and disclosure of the invention. This application is intended to cover any variations, uses, or adaptations of the invention that follow the general principles of the invention and include common knowledge or customary techniques in the art not disclosed herein. The specification and examples are to be considered exemplary only, and the true scope and spirit of the invention are indicated by the following claims.

[0060] It should be understood that the present invention is not limited to the precise structure described above and shown in the accompanying drawings, and various modifications and changes can be made without departing from its scope. The scope of the invention is limited only by the appended claims.

[0061] The above description is merely a preferred embodiment of the present invention and does not constitute any limitation on the present invention. Any simple modifications, alterations, or equivalent structural changes made to the above embodiments based on the technical essence of the present invention shall still fall within the protection scope of the present invention.

Claims

1. An energy-saving system for a steam turbine hot-state drainage system, characterized in that, It includes a main steam pipe (1), a high-pressure cylinder (4), a reheat steam pipe (2), a medium-pressure cylinder (5), a low-pressure steam pipe (3), and a low-pressure cylinder (6); The main steam pipe (1) is connected to the inlet of the high-pressure cylinder (4), the reheat steam pipe (2) is connected to the inlet of the medium-pressure cylinder (5), the low-pressure steam pipe (3) is connected to the inlet of the low-pressure cylinder (6), the main steam pipe (1) is connected to a steam drain pipe (7), and the steam drain pipe (7) is equipped with a drain valve (8), a pressure gauge (9) and a thermometer (10). It also includes a controller, which is connected to a drain valve (8), a pressure gauge (9) and a temperature gauge (10); The controller includes a subtraction block, a temperature calculation function module, a subtraction block, an adder, a preset temperature input terminal, a first selection block, a water valve open status input terminal, a first AND block, a medium-pressure rotor center temperature input terminal, a temperature limit input terminal, a second selection block, a second AND block, a drain independent control loop input terminal, a third AND block, and a drain valve close command output terminal. The output of the thermometer (10) is connected to the input of the subtraction block. The output of the pressure gauge (9) is connected to the input of the subtraction block via the temperature calculation function module. The output of the adder is connected to the preset temperature input and the input of the first selection block. The input of the drain valve open state and the output of the first selection block are connected to the input of the first AND block. The input of the medium-pressure rotor center temperature and the temperature limit input are connected to the input of the second selection block. The output of the second selection block and the output of the first AND block are connected to the input of the second AND block. The output of the second AND block and the input of the drain independent control loop are connected to the input of the third AND block. The output of the third AND block is connected to the output of the drain valve closed command.

2. The energy-saving system for the steam turbine hot-state drainage system according to claim 1, characterized in that, It also includes a generator, and the generator, high-pressure cylinder (4), medium-pressure cylinder (5) and low-pressure cylinder (6) are arranged coaxially.

3. The energy-saving system for the steam turbine hot-state drainage system according to claim 1, characterized in that, The reheat steam pipe (2) is provided with a first drainage pipe.

4. The energy-saving system for the steam turbine hot-state drainage system according to claim 3, characterized in that, The first drainage pipe is equipped with a first valve, a first pressure gauge and a first thermometer.

5. The energy-saving system for the steam turbine hot-state drainage system according to claim 1, characterized in that, A second drainage pipe is provided on the low-pressure steam pipe (3).

6. The energy-saving system for the steam turbine hot-state drainage system according to claim 5, characterized in that, The second drainage pipe is equipped with a second valve, a second pressure gauge, and a second thermometer.

7. A control method for the energy-saving system of the steam turbine hot-state condensate drainage system as described in claim 1, characterized in that, Includes the following steps: Input the pressure value P measured by pressure gauge (9) into the temperature calculation function block to calculate the saturation temperature T of the steam at that pressure. st The temperature T measured by the thermometer (10) is compared with T st The difference is calculated and then input into the first selection block for comparison with 50°C. If the difference is greater than 50°C, the output signal is sent to the first selection block. At the same time, when the drain valve (8) is in the open state, the drain valve (8) outputs the open feedback state trigger signal to the first selection block. At this time, the first selection block triggers the signal. Otherwise, the first selection block does not trigger the signal. The center temperature T of the intermediate-pressure rotor was measured at a measuring point on the turbine body. C And input it into the second major block, along with the preset turbine temperature determination temperature T. W Comparison, when T C Greater than T W If the unit is in a steady-state startup process, the second major block will be triggered; otherwise, the second major block will not be triggered. When the second major block is triggered, it will be sent to the second major block. When both the first and second major blocks are triggered, the second major block will be triggered and sent to the third major block. When the independent control loop for condensate drainage is engaged, and the second block trigger signal is triggered, a command to close the condensate drainage valve is output, causing the condensate drainage valve (8) to close.

8. The control method for the energy-saving system of the steam turbine hot-state condensate drainage system according to claim 7, characterized in that, It also includes a generator, and the generator, high-pressure cylinder (4), medium-pressure cylinder (5) and low-pressure cylinder (6) are arranged coaxially.

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