Energy-saving system of steam turbine warm-hot-state drainage system and control method of energy-saving system

Abstract

The invention discloses an energy-saving system of a steam turbine warm and hot state drainage system and a control method of the energy-saving system. The energy-saving system comprises 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. The main steam pipeline is communicated with an inlet of the high-pressure cylinder, the reheat steam pipeline is communicated with an inlet of the medium-pressure cylinder, the low-pressure steam pipeline is communicated with an inlet of the low-pressure cylinder, the main steam pipeline is connected with a steam drainage pipeline, and a drainage valve, a pressure gauge and a thermometer are arranged on the steam drainage pipeline. According to the system and the control method thereof, the drain valve can be automatically closed when the unit is started in the warm state, steam consumption of a steam turbine in the warm state starting process of the unit is reduced to the maximum extent, and the starting time of the unit is saved.

Description

Technical Field

[0001] The present invention belongs to the field of energy conservation in the operation and start-up of steam turbines, and relates to an energy-saving system for the warm-state drainage system of a steam turbine and its control method. Background Art

[0002] During the start-up process of a steam turbine, the steam turbine and its steam pipelines need to be fully drained. However, the drainage system of the steam turbine is uniformly closed according to the grid connection and load-bearing nodes of the machine, and cannot perform separate automatic closed-loop control on the steam turbine drainage system pipelines in combination with the actual state of the unit. It is necessary for manual operation of individual pipeline valves in combination with the drainage temperature of the drainage pipelines. When the unit starts in a warm state, due to the presence of the pipeline insulation layer, the steam pipelines do not need to be drained for a long time. Therefore, the drainage of the steam pipelines can be closed in advance, which can not only reduce the steam consumption during unit start-up, but also save the unit start-up time. Therefore, when the unit starts in a warm state, closing the drainage system valves in advance has great energy-saving potential. However, in the prior art, the opening and closing logic of the valves of the steam pipelines and the main body drainage pipelines of the steam turbine according to the steam turbine load cannot automatically close individual drainage valves during the warm-state start-up of the unit. Summary of the Invention

[0003] The purpose of the present invention is to overcome the above-mentioned shortcomings of the prior art, and provide an energy-saving system for the warm-state drainage system of a steam turbine and its control method. This system and its control method can automatically close the drainage valves during the warm-state start-up of the unit, and can reduce the steam consumption of the steam turbine during the warm-state start-up process of the unit to the greatest extent and save the unit start-up time.

[0004] To achieve the above purpose, the present invention discloses an energy-saving system for the warm-state drainage system of a steam turbine, including a main steam pipeline, a high-pressure cylinder, a reheater 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 reheater steam pipeline is connected to the inlet of the intermediate-pressure cylinder, the low-pressure steam pipeline is connected to the inlet of the low-pressure cylinder, the main steam pipeline is connected with a steam drainage pipeline, and a drainage valve, a pressure gauge and a thermometer are arranged on the steam drainage pipeline.

[0006] The further improvement of the energy-saving system for the warm-state drainage system of the steam turbine according to the present invention lies in:

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

[0008] Furthermore, it further includes a controller, and the controller is connected to the drainage valve, the pressure gauge and the thermometer.

[0009] Furthermore, a first drainage pipeline is arranged on the reheater steam pipeline.

[0010] Further, a first valve, a first pressure gauge and a first thermometer are provided on the first hydrophobic pipeline.

[0011] Further, a second hydrophobic pipeline is provided on the low-pressure steam pipeline.

[0012] Further, a second valve, a second pressure gauge and a second thermometer are provided on the second hydrophobic pipeline.

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

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

[0015] The present invention discloses a control method for an energy-saving system of a warm and hot state hydrophobic system of a steam turbine, including 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 corresponding steam at this pressure st , subtract the temperature T measured by the thermometer from T st , then input the difference into the first major selection block to compare with 50°C. When it is greater than 50°C, output a signal to the first AND block. At the same time, when the hydrophobic valve is in the open state, the hydrophobic valve outputs an open feedback state trigger signal to the first AND block. At this time, the first AND block triggers a signal, otherwise, the first AND block does not trigger a signal;

[0017] Measure the medium-pressure rotor center temperature T C through the measuring points of the steam turbine body and input it into the second major selection block to compare with the preset steam turbine warm state determination temperature T W , when T C is greater than T W, the unit is in a steady-state startup process, and the second largest selection block trigger signal is generated. Otherwise, the second largest selection block is not triggered. When the second largest selection block trigger signal is generated, it is sent to the second AND block. When the first AND block trigger signal and the second largest selection block trigger signal are present, the second AND block trigger signal is generated and sent to the third AND block;

[0018] When the independent drain control loop is put into operation and the second AND block trigger signal is present, an instruction to close the drain valve is output to close the drain valve.

[0019] A further improvement in the control method of the energy-saving system of the warm-state drain system of the steam turbine according to the present invention lies in:

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

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

[0022] For the warm-state drain system energy-saving system of the steam turbine and its control method according to the present invention, when the drain pipeline has been fully drained, the drain valve on the main steam pipeline is timely closed to avoid waste and loss of high-quality superheated steam, which is beneficial to improving the utilization rate of superheated steam during the startup process of the unit, enhancing the startup efficiency, and thus automatically closing the drain valve during the warm-state startup of the unit, minimizing the steam consumption of the steam turbine during the warm-state startup process of the unit and saving the startup time of the unit. It should be noted that the present invention abandons the traditional control method of determining the drain switch based on load, and can perform independent switching operations on the drain valves of the steam turbine drain pipelines through independent control loops. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] The specification drawings forming a part of the present invention are used to provide a further understanding of the present invention. The schematic embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the drawings:

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

[0025] Figure 2 is the schematic diagram of the controller in the present invention.

[0026] Among them, 1 is the main steam pipeline, 2 is the reheater steam pipeline, 3 is the low-pressure steam pipeline, 4 is the high-pressure cylinder, 5 is the intermediate-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 thermometer. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0027] The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are some, but not all, of the embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

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

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

[0030] It should be further understood that the term "and / or" used in the specification of the present invention and the appended claims refers to any combination and all possible combinations of one or more of the associated listed items, and includes these combinations. For example, A and / or B can represent three cases: A exists alone, A and B exist simultaneously, and B exists alone. In addition, the character " / " in the present invention generally represents an "or" relationship between the contextually related objects.

[0031] It should be understood that although the terms first, second, third, etc. may be used in the embodiments of the present invention to describe preset ranges, etc., these preset ranges should not be limited to these terms. These terms are only used to distinguish the preset ranges from each other. 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 herein can be interpreted as "when" or "while" or "in response to determining" or "in response to detecting". Similarly, depending on the context, the phrase "if determined" or "if detecting (stated condition or event)" can be interpreted as "when determined" or "in response to determining" or "when detecting (stated condition or event)" or "in response to detecting (stated condition or event)".

[0033] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are some, but not all, of the embodiments of the present invention. Usually, the components described and shown in the accompanying drawings here can 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 present invention, but merely represents selected embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts fall within the scope of protection of the present invention.

[0034] Schematic diagrams of various structures according to the disclosed embodiments of the present invention are shown in the accompanying drawings. These figures are not drawn to scale, where for the purpose of clear expression, some details are enlarged and some details may be omitted. The shapes of various regions and layers shown in the figures, as well as their relative sizes and positional relationships, are merely exemplary. In practice, there may be deviations due to manufacturing tolerances or technical limitations, and those skilled in the art can design regions / layers with different shapes, sizes, and relative positions according to actual needs.

[0035] Embodiment 1

[0036] Reference Figure 1 , the energy-saving system of the warm and hot state steam drainage system of the steam turbine described in the present invention includes a controller, a main steam pipeline 1, a reheater 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 drainage pipeline 7, a drainage valve 8, a pressure gauge 9, and a thermometer 10;

[0037] The main steam pipeline 1 is connected to the inlet of the high-pressure cylinder 4, the reheater steam pipeline 2 is connected to the inlet of the intermediate-pressure cylinder 5, the low-pressure steam pipeline 3 is connected to the inlet of the low-pressure cylinder 6, the generator, the high-pressure cylinder 4, the intermediate-pressure cylinder 5, and the low-pressure cylinder 6 are coaxially arranged. The main steam pipeline 1 is connected with a steam drainage pipeline 7, and a drainage valve 8, a pressure gauge 9, and a thermometer 10 are arranged on the steam drainage pipeline 7.

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

[0039] As an implementation manner of the present invention, a first drainage pipeline is arranged on the reheater steam pipeline 2.

[0040] As an implementation manner of the present invention, a first valve, a first pressure gauge, and a first thermometer are arranged on the first drainage pipeline.

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

[0042] As an embodiment of the present invention, a second valve, a second pressure gauge and a second thermometer are provided on the second drain pipe.

[0043] As an embodiment of the present invention, referring to 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 major selection block, a water valve open state input terminal, a first AND block, a medium-pressure rotor center temperature input terminal, a temperature limit input terminal, a second major 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 terminal of the thermometer 10 is connected to the input terminal of the subtraction block, the output terminal of the pressure gauge 9 is connected to the input terminal of the subtraction block through the temperature calculation function module, the output terminal of the adder is connected to the preset temperature input terminal and the input terminal of the first major selection block, the drain valve open state input terminal and the output terminal of the first major selection block are connected to the input terminal of the first AND block, the medium-pressure rotor center temperature input terminal and the temperature limit input terminal are connected to the input terminal of the second major selection block, the output terminal of the second major selection block and the output terminal of the first AND block are connected to the input terminal of the second AND block, the output terminal of the second AND block and the drain independent control loop input terminal are connected to the input terminal of the third AND block, and the output terminal of the third AND block is connected to the drain valve close command output terminal.

[0045] Embodiment 2

[0046] The present invention discloses a control method for an energy-saving system of a warm thermal state drain system of a steam turbine. The energy-saving system of the warm thermal state drain system of the steam turbine includes a controller, a main steam pipe 1, a reheater 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 drain pipe 7, a drain 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 major selection block, a water valve open state input terminal, a first AND block, a medium-pressure rotor center temperature input terminal, a temperature limit input terminal, a second major 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 specific connection relationship is as shown in Embodiment 1.

[0047] Specifically, the control method for the energy-saving system of the warm thermal state drain system of the steam turbine includes the following steps:

[0048] Input the pressure value P measured by the pressure gauge 9 into the temperature calculation function block to calculate the saturation temperature T of the corresponding steam at this pressure st , and compare the temperature T measured by the thermometer 10 with T stTake the difference, and then input the difference value into the first major selection block to compare with 50°C. When it is greater than 50°C, output a signal to the first AND 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 AND block. At this time, the first AND block triggers a signal; otherwise, the first AND block does not trigger a signal.

[0049] Measure the center temperature T of the intermediate pressure rotor through the measuring points on the steam turbine body C , and input it into the second major selection block to compare with the preset temperature determination temperature T of the warm state of the steam turbine W . When T C is greater than T W , the unit is in a steady-state startup process, and the second major selection block triggers a signal; otherwise, the second major selection block does not trigger. When the second major selection block triggers a signal, it is sent to the second AND block. When the first AND block triggers a signal and the second major selection block triggers a signal, the second AND block triggers a signal and sends it to the third AND block.

[0050] When the drain independent control loop is put into operation and the second AND block triggers a signal, output an instruction to close the drain valve to close the drain valve 8.

[0051] Embodiment 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 the control method of the energy-saving system of the warm and hot state drain system of the steam turbine. Among them, the memory may include internal memory, such as high-speed random access memory, and may also include non-volatile memory, such as at least one disk memory, etc.; the processor, network interface, and memory are interconnected through an internal bus, and this internal bus can be an Industry Standard Architecture bus, a Peripheral Component Interconnect standard bus, an Extended Industry Standard Architecture bus, etc. The bus can be divided into an address bus, a data bus, a control bus, etc. The memory is used to store programs. Specifically, the program may include program code, and the program code includes computer operation instructions. The memory may include internal memory and non-volatile memory and provide instructions and data to the processor.

[0053] Embodiment 4

[0054] A computer-readable storage medium stores a computer program. When the computer program is executed by a processor, it implements the steps of the control method of the energy-saving system of the warm and hot state drain system of the steam turbine. Specifically, the computer-readable storage medium includes, but is not limited to, for example, 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 disc, magnetic disk, etc.

[0055] Those skilled in the art should understand that the embodiments of the present application can be provided as a method, a system, or a computer program product. Therefore, the present application can take the form of a complete hardware embodiment, a complete software embodiment, or an embodiment combining software and hardware aspects. Moreover, the present 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] The present application is described with reference to the flowcharts and / or block diagrams of methods, apparatuses (systems), and computer program products according to the embodiments of the present application. It should be understood that each flow and / or block in the flowchart and / or block diagram can be implemented by computer program instructions, and the combination of the flows and / or blocks in the flowchart and / or block diagram can also be implemented by computer program instructions. These computer program instructions can be provided to the processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing devices to generate a machine, so that the instructions executed by the processor of the computer or other programmable data processing devices generate means for implementing the specified functions in one Figure 1 flow or multiple flows and / or blocks Figure 1 block or multiple blocks.

[0057] These computer program instructions can also be stored in a computer-readable memory that can direct a computer or other programmable data processing device to work in a specific manner, so that the instructions stored in the computer-readable memory generate a manufactured article including instruction means, and the instruction means implement the specified functions in one Figure 1 flow or multiple flows and / or blocks Figure 1 block or multiple blocks.

[0058] These computer program instructions can also be loaded onto a computer or other programmable data processing device, so that a series of operation steps are executed on the computer or other programmable device to generate a computer-implemented process. Thus, the instructions executed on the computer or other programmable device provide steps for implementing the specified functions in one Figure 1 flow or multiple flows and / or blocks Figure 1 block or multiple blocks.

[0059] After considering the specification and the disclosure of the invention, those skilled in the art will easily think of other embodiments of the present invention. The present application is intended to cover any variations, uses, or adaptations of the present invention, which follow the general principles of the present invention and include the common general knowledge or conventional technical means in the technical field not disclosed in the present invention. The specification and the embodiments are only regarded as exemplary, and the true scope and spirit of the present invention are pointed out by the following claims.

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

[0061] As described above, the above are only preferred embodiments of the present invention, and do not impose any limitations on the present invention. Any simple modifications, changes, and equivalent structural changes made to the above embodiments according to the technical essence of the present invention still fall within the scope of protection of the technical solution of the present invention.

Claims

1. A steam turbine warm-state drain system energy-saving system, characterized in that: It comprises a main steam pipeline (1), a high-pressure cylinder (4), a reheat steam pipeline (2), a medium-pressure cylinder (5), a low-pressure steam pipeline (3) and a low-pressure cylinder (6); The main steam pipeline (1) is connected to the inlet of the high-pressure cylinder (4), the reheat steam pipeline (2) is connected to the inlet of the medium-pressure cylinder (5), and the low-pressure steam pipeline (3) is connected to the inlet of the low-pressure cylinder (6). The main steam pipeline (1) is connected to a steam drain pipeline (7), and the steam drain pipeline (7) is provided with a drain valve (8), a pressure gauge (9) and a temperature gauge (10).

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

3. The steam turbine warm-state drain system energy-saving system according to claim 1, characterized in that: It also includes a controller, which is connected to the steam trap (8), the pressure gauge (9) and the temperature gauge (10).

4. The steam turbine warm-state drain system energy-saving system according to claim 1, characterized in that: The reheat steam pipe (2) is provided with a first drain pipe.

5. The steam turbine warm-state drain system energy-saving system according to claim 1, characterized in that: The first drain pipe is provided with a first valve, a first pressure gauge and a first thermometer.

6. The steam turbine warm-state drain system energy-saving system according to claim 1, characterized in that: The low-pressure steam pipeline (3) is provided with a second drain pipeline.

7. The steam turbine warm-state drain system energy-saving system according to claim 1, characterized in that: The second drain pipe is provided with a second valve, a second pressure gauge and a second thermometer.

8. The steam turbine warm-state drain system energy-saving system according to claim 3, characterized in that: The controller includes a subtraction block, a temperature calculation function module, a subtraction block, an adder, a preset temperature input terminal, a first large block, a water valve opening state input terminal, a first AND block, a medium-pressure rotor center temperature input terminal, a temperature limit input terminal, a second large block, a second AND block, a drain independent control loop input terminal, a third AND block and a drain valve closing instruction output terminal; The output end of the temperature meter (10) is connected to the input end of the subtraction block, the output end of the pressure meter (9) is connected to the input end of the subtraction block via the temperature calculation function module, the output end of the adder and the preset temperature input end are connected to the input end of the first large block, the drain valve open state input end and the output end of the first large block are connected to the input end of the first AND block, the medium pressure rotor center temperature input end and the temperature limit input end are connected to the input end of the second large block, the output end of the second large block and the output end of the first AND block are connected to the input end of the second AND block, the output end of the second AND block and the drain independent control loop input end are connected to the input end of the third AND block, and the output end of the third AND block is connected to the drain valve closing instruction output end.

9. A control method for the energy-saving system of the steam turbine warm-state drain system according to claim 8, characterized in that: The following steps are involved: The pressure value P measured by the pressure gauge (9) is input into the temperature calculation function block to calculate the saturation temperature T of the steam corresponding to the pressure. st , the temperature T measured by the thermometer (10) and T st The difference is input into the first large selection block and compared with 50°C. When it is greater than 50°C, a signal is output to the first AND block. At the same time, when the steam trap (8) is in the open state, the steam trap (8) outputs an open feedback state trigger signal to the first AND block. At this time, the first AND block triggers the signal. Otherwise, the first AND block does not trigger the signal. Measure the center temperature T of the medium-pressure rotor through the turbine body measuring point C , and input into the second large selection block, and compared with the preset turbine temperature determination temperature T W For comparison, when T C Greater than T W , the unit is in the steady-state startup process, then the second large block triggers the signal, otherwise, the second large block is not triggered; when the second large block triggers the signal, it is transmitted to the second AND block, when the first AND block triggers the signal and the second large block triggers the signal, the second AND block triggers the signal and is sent to the third AND block; When the drain independent control loop is put into operation and the second AND block triggers the signal, a drain valve closing instruction is output to close the drain valve (8).

10. The control method of the steam turbine warm-state drain system energy-saving system according to claim 9, characterized in that: It also includes a generator, wherein the generator, a high-pressure cylinder (4), a medium-pressure cylinder (5) and a low-pressure cylinder (6) are coaxially arranged.

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