A method and system for controlling drainage of a thermal power generating unit

Abstract

The application relates to a method and system for controlling drainage of a thermal power generating unit, wherein the method comprises: measuring the steam pressure and steam temperature at the drainage valve and the upstream position of each drainage pipeline of the thermal power generating unit in real time through a temperature-pressure sensor; calculating the saturated steam temperature under the steam pressure in real time, calculating the corresponding superheat degree according to the saturated steam temperature and the steam temperature; and automatically controlling the opening and closing of the drainage valve based on the superheat degree and a preset threshold. The application solves the problem of how to realize automatic, accurate and timely control of the drainage of the thermal power generating unit, realizes automatic control of the drainage control system, reduces the human judgment and operation of the operating personnel, eliminates the subjectivity and blindness of the drainage operation, improves the safety and automation level of the unit, and realizes the opening and closing of the drainage valve at the optimal time of each pipeline, reduces steam loss, and improves the operation efficiency of the unit.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of thermal power generation, in particular to a drainage control method and system for a thermal power generating unit. BACKGROUND

[0002] The drainage system in a thermal power plant is a complex and huge system. Whether it is a coal-fired power plant or a gas-fired power plant, the design principle is to recover the working medium and heat to ensure the safety and economic operation of the equipment. The control effect of the drainage system directly affects the safety and economy of the unit.

[0003] Generally, the running personnel determines the opening and closing of the boiler side steam pipe drainage valve according to the running experience by using the steam pressure, and determines the opening and closing of the steam turbine body and the steam pipe drainage valve on the steam turbine side by using the unit load and the start and stop state of the steam turbine. In this control mode, all drainage valves are considered as a whole and are opened and closed at the same time. Although the operation is simple, in the actual process, the positions of the drainage points are not the same, and the steam states of the pipelines are also slightly different. Blind drainage is inevitable when all drainage valves are opened and closed at the same time, and the drainage valves cannot be precisely controlled. At the same time, in the case of sudden change of working condition during the operation of the unit or human judgment error, the valve opening and closing will not be timely, which will cause steam loss and waste, and affect the efficiency of the unit. On the other hand, insufficient drainage will cause the pipeline to be not clean and store condensed water. If this condensed water cannot be discharged in time, it will be pushed by the high-speed flowing steam, which will cause pipeline impact and damage to the steam turbine blades, and even cause personal accidents.

[0004] At present, there is no effective solution to the problem of how to realize automatic, precise and timely control of drainage in the thermal power generating unit in the related art. SUMMARY

[0005] The embodiments of the present application provide a drainage control method and system for a thermal power generating unit to at least solve the problem of how to realize automatic, precise and timely control of drainage in the thermal power generating unit in the related art.

[0006] In a first aspect, the embodiments of the present application provide a drainage control method for a thermal power generating unit, which comprises:

[0007] A temperature and pressure sensor is arranged at each drainage valve on the drainage pipe of the thermal power generating unit and at an upstream position of the drainage valve.

[0008] The steam pressure and steam temperature of the drainage valve and the upstream position are measured in real time by the temperature and pressure sensor.

[0009] calculating a corresponding superheat degree according to the saturated steam temperature and the steam temperature;

[0010] controlling opening and closing of the trap valve automatically based on the superheat degree and a preset threshold.

[0011] In some embodiments, the temperature and pressure sensors are respectively arranged at the trap valve and an upstream position of the trap valve on each steam drain pipeline of the thermal power generating unit.

[0012] The temperature and pressure sensors are respectively arranged at the trap valve and an upstream position of the trap valve on a boiler side steam pipeline of the thermal power generating unit.

[0013] The temperature and pressure sensors are respectively arranged at the trap valve and an upstream position of the trap valve on a steam turbine body of the thermal power generating unit.

[0014] The temperature and pressure sensors are respectively arranged at the trap valve and an upstream position of the trap valve on a steam turbine side steam pipeline of the thermal power generating unit.

[0015] In some embodiments, the trap valve comprises a trap primary valve and a trap secondary valve.

[0016] In the case of performing trap valve opening operation, the trap secondary valve is opened first, and the trap primary valve is opened after the trap secondary valve has been opened and feedback triggering occurs.

[0017] In the case of performing trap valve closing operation, the trap primary valve is closed first, and the trap secondary valve is closed after the trap primary valve has been closed and feedback triggering occurs.

[0018] In some embodiments, the real-time calculation of the saturated steam temperature under the steam pressure comprises:

[0019] According to the Antoine equation, a relationship equation between the steam pressure and the saturated steam temperature is constructed, and the saturated steam temperature is calculated in real time based on the relationship equation and the real-time measured steam pressure.

[0020] In some embodiments, the real-time calculation of the saturated steam temperature under the steam pressure comprises:

[0021] The Antoine equation under water medium is known wherein, A, B and C are constants, P is the steam pressure, K is the absolute temperature of the saturated steam under the corresponding pressure, and T is the saturated steam temperature under the corresponding pressure.

[0022] The Antoine equation is converted into that is, wherein a, b and c are to-be-solved coefficients;

[0023] The to-be-solved coefficients a, b and c are solved by using a least square fitting formula Y = X*θ + E, wherein X is an n*k matrix, Y is an n*1 column vector, θ is an n*1 column vector of the to-be-solved coefficients, and E is an n*1 residual column vector;

[0024] The saturated steam temperature is calculated in real time based on the to-be-solved coefficients a, b and c, the real-time measured steam pressure, and the Antoine equation The saturated steam temperature is calculated in real time based on the to-be-solved coefficients a, b and c, the real-time measured steam pressure, and the Antoine equation

[0025] In some embodiments, the automatic control of the opening and closing of the drain valve based on the superheat degree and a preset threshold value comprises:

[0026] The automatic control of the opening and closing of the drain valve based on the superheat degree and a preset threshold value comprises:

[0027] In some embodiments, the automatic control of the opening and closing of the drain valve based on the superheat degree and a preset threshold value comprises:

[0028] The drain valve of the boiler side steam pipeline is controlled to be opened based on a boiler side automatic opening logic, wherein the boiler side automatic opening logic is that the superheat degree at the drain valve of the boiler side steam pipeline is less than or equal to a preset threshold value K2, and an opening operation is performed.

[0029] The drain valve of the boiler side steam pipeline is controlled to be closed based on a boiler side automatic closing logic, wherein the boiler side automatic closing logic is that the superheat degree at the drain valve of the boiler side steam pipeline is greater than or equal to a preset threshold value K1, or the superheat degree at a position upstream of the drain valve has a rate of increase greater than or equal to a preset threshold value V1, and the superheat degree at the drain valve is greater than or equal to a preset threshold value K1-△t, and a closing operation is performed.

[0030] In some embodiments, the automatic control of the opening and closing of the drain valve based on the superheat degree and a preset threshold value comprises:

[0031] The drain valve of the boiler side steam pipeline is controlled to be opened based on a boiler side automatic opening logic, wherein the boiler side automatic opening logic is that the superheat degree at the drain valve of the boiler side steam pipeline is less than or equal to a preset threshold value K2, and an opening operation is performed.

[0032] The drain valve of the boiler side steam pipeline is controlled to be closed based on a boiler side automatic closing logic, wherein the boiler side automatic closing logic is that the superheat degree at the drain valve of the boiler side steam pipeline is greater than or equal to a preset threshold value K1, or the superheat degree at a position upstream of the drain valve has a rate of increase greater than or equal to a preset threshold value V1, and the superheat degree at the drain valve is greater than or equal to a preset threshold value K1-△t, and a closing operation is performed.

[0033] In some embodiments, based on the superheat and a preset threshold, automatically controlling the opening and closing of the steam trap of the turbine side steam pipe includes:

[0034] Based on the turbine side automatic opening logic, controlling the opening of the steam trap of the turbine side steam pipe, wherein the turbine side automatic opening logic is that the superheat at the steam trap of the turbine side steam pipe is less than or equal to a preset threshold K7, the condenser vacuum is greater than or equal to a preset threshold K8, and the steam pressure is greater than or equal to a preset threshold K9, and the opening operation is performed.

[0035] Based on the turbine side automatic closing logic, controlling the closing of the steam trap of the turbine side steam pipe, wherein the turbine side automatic closing logic is that the superheat at the steam trap of the turbine side steam pipe is greater than or equal to a preset threshold K6, the closing operation is performed; or the condenser vacuum is greater than or equal to a preset threshold K5, the closing operation is performed; or the superheat increasing rate at the upstream position of the steam trap is greater than a preset threshold V2, and the superheat at the steam trap is greater than a preset threshold K6-△t, the closing operation is performed.

[0036] In a second aspect, the embodiments of the present application provide a steam drainage control system of a thermal power generating unit, the system comprising a data measurement module, a real-time calculation module and an execution control module.

[0037] The data measurement module is configured to measure the steam pressure and the steam temperature of the steam trap and the upstream position of the steam trap in each steam drainage pipe of the thermal power generating unit in real time through a temperature and pressure sensor.

[0038] The real-time calculation module is configured to calculate the saturated steam temperature under the steam pressure in real time, and calculate the corresponding superheat according to the saturated steam temperature and the steam temperature.

[0039] The execution control module is configured to automatically control the opening and closing of the steam trap according to the superheat and a preset threshold.

[0040] Compared to related technologies, the present application provides a method and system for controlling the condensate drain of a thermal power generating unit. This method involves installing temperature and pressure sensors at the condensate drain valves on each condensate drain pipe of the thermal power generating unit, as well as upstream of the condensate drain valves. The temperature and pressure sensors measure the steam pressure and steam temperature at the condensate drain valves and upstream locations in real time. The saturated steam temperature under the steam pressure is calculated in real time, and the corresponding superheat is calculated based on the saturated steam temperature and the steam temperature. Based on the superheat and a preset threshold, the opening and closing of the condensate drain valves is automatically controlled. This solves the problem of how to achieve fully automatic, accurate, and timely control of condensate draining in thermal power generating units. It realizes fully automatic control of the condensate draining control system, reduces human judgment and operation, eliminates the subjectivity and blindness of condensate draining operations, improves unit safety and automation level, and ensures that the condensate drain valves on each pipe open and close at the optimal time, reducing steam loss and improving unit operating efficiency. Attached Figure Description

[0041] The accompanying drawings, which are included to provide a further understanding of this application and form part of this application, illustrate exemplary embodiments and are used to explain this application, but do not constitute an undue limitation of this application. In the drawings:

[0042] Figure 1 This is a flowchart of the steps of the condensate control method for a thermal power generating unit according to an embodiment of this application;

[0043] Figure 2 This is a schematic diagram of the process for controlling the steam trap in the boiler-side steam pipe according to an embodiment of this application;

[0044] Figure 3 This is a schematic diagram of the control process of the steam turbine body drain valve according to an embodiment of this application;

[0045] Figure 4 This is a schematic diagram of the process for controlling the steam trap on the turbine side according to an embodiment of this application;

[0046] Figure 5 This is a schematic diagram of the control process of the primary valve and the secondary valve of the steam trap according to an embodiment of this application;

[0047] Figure 6 This is a structural block diagram of the condensate control system of a thermal power generating unit according to an embodiment of this application;

[0048] Figure 7 This is a schematic diagram of the internal structure of an electronic device according to an embodiment of this application.

[0049] Figure descriptions: 61. Data measurement module; 62. Real-time calculation module; 63. Execution control module. Detailed Implementation

[0050] In order to make the purposes, technical solutions and advantages of the present application clearer, the present application is described and explained below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and should not be used to limit the present application. Based on the embodiments provided by the present application, all other embodiments obtained by those of ordinary skill in the art without creative effort belong to the scope of the present application.

[0051] Obviously, the accompanying drawings in the following description are only some examples or embodiments of the present application, and for those of ordinary skill in the art, the present application can be applied to other similar scenarios without creative effort based on the accompanying drawings. In addition, it can be understood that although the efforts made in this development process can be complex and lengthy, for those of ordinary skill in the art related to the content disclosed in the present application, some design, manufacture or production changes based on the technical content disclosed in the present application are only routine technical means and should not be understood as insufficient disclosure of the present application.

[0052] In the present application, the phrase "embodiment" means that the specific features, structures or properties described in conjunction with the embodiment can be included in at least one embodiment of the present application. The appearance of this phrase at various places in the specification does not necessarily mean the same embodiment, nor is it an independent or alternative embodiment to other embodiments. It is explicitly and implicitly understood by those of ordinary skill in the art that the embodiments described in the present application can be combined with other embodiments without conflict.

[0053] Unless otherwise defined, technical terms and scientific terms used in the present application shall have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains. The terms "a", "an", "one", "this", and similar referents in the context of describing the application are to be construed to be inclusive, not exclusive. For example, the use of the term "comprises" or "comprising" or "includes" or "including" or "has" or "having" or "contains" or "containing" or "consists" or "consisting" or "consists of" or "consisting of" to describe certain steps or modules (units) of the processes, methods, systems, products, or devices described herein, is intended to mean that the processes, methods, systems, products, or devices can consist of, but are not limited to, the listed steps or modules (units), and can also include other steps or modules (units) not listed, or can also include other steps or modules (units) inherent to the processes, methods, systems, products, or devices. The terms "connected", "coupled", or "linked" or similar terms in the context of the present application are not limited to physical or mechanical connections, but can also include electrical connections, whether direct or indirect. The term "plurality" refers to two or more. The term "and / or" describes the associated relationship of the associated objects, which means that there can be three relationships, for example, "A and / or B" can mean that A exists alone, A and B exist together, and B exists alone. The character " / " generally represents an "or" relationship between the associated objects. The terms "first", "second", "third", and the like in the present application are only to distinguish similar objects, and do not represent a specific order of the objects.

[0054] The embodiment of the present application provides a drain control method of a thermal power generating unit, Figure 1 The step flow chart of the drain control method of the thermal power generating unit according to the embodiment of the present application is shown in Figure 1 The method comprises the following steps:

[0055] In step S102, a temperature and pressure sensor is arranged at each drain valve on each drain pipeline of the thermal power generating unit, and at an upstream position of the drain valve.

[0056] Specifically, a temperature and pressure sensor is arranged at each drain valve on each steam pipeline of the boiler side of the thermal power generating unit, and at an upstream position of the drain valve.

[0057] A temperature and pressure sensor is arranged at each drain valve on the steam turbine body of the thermal power generating unit, and at an upstream position of the drain valve.

[0058] A temperature and pressure sensor is arranged at each drain valve on each steam pipeline of the steam turbine side of the thermal power generating unit, and at an upstream position of the drain valve.

[0059] In step S104, the temperature and pressure sensor is used to measure the steam pressure and steam temperature of the drain valve and the upstream position in real time.

[0060] Preferably, the temperature and pressure sensors are arranged at each drain valve and at a suitable position upstream of the drain valve on the drain pipeline, and the upstream position is preferably 300-500 meters away from the drain valve, to measure the pressure and temperature of the steam in the pipeline at the two positions in real time.

[0061] In step S106, the saturated steam temperature under the steam pressure is calculated in real time, and the corresponding superheat degree is calculated according to the saturated steam temperature and the steam temperature.

[0062] Specifically, the relationship equation between the steam pressure and the saturated steam temperature is constructed according to the Antoine equation, and the saturated steam temperature is calculated in real time based on the relationship equation and the real-time measured steam pressure.

[0063] Preferably, the Antoine equation under the water medium is known , wherein, A, B and C are constants, P is the steam pressure, K is the absolute temperature of the saturated steam under the corresponding pressure, and T is the saturated steam temperature under the corresponding pressure.

[0064] The Antoine equation is converted into , that is, , wherein a, b and c are to-be-solved coefficients.

[0065] The least square fitting formula Y=X*θ+E is used, and further, the objective function Q=E T *E, then the least square estimation of θ is , to obtain the to-be-solved coefficients a, b and c, wherein X is an n*k matrix, Y is an n*1 column vector, θ is an n*1 column vector of to-be-solved coefficients, E is an n*1 residual column vector, n is the number of variable parameters, and k is the number of to-be-solved coefficients.

[0066] Based on the obtained to-be-solved coefficients a, b and c, the real-time measured steam pressure, and the Antoine equation , the saturated steam temperature is calculated in real time.

[0067] It should be noted that the calculation method of the superheat degree of the medium is generally to obtain the corresponding saturated temperature under a certain pressure through the table lookup method (water vapor saturation temperature and pressure table), and then to obtain the superheat degree of the medium under the corresponding pressure by the difference between the actual measured medium temperature and the queried saturated temperature. This method is accurate but cannot be used for real-time calculation and participation in regulation. The embodiment proposes a new mathematical model for real-time calculation of the superheat degree of the medium based on the Antoine equation (the Antoine equation introduces the relationship between the steam pressure of different substances at different temperatures) , wherein the to-be-solved coefficients a=9.3876, b=3826.36 and c=227.68 are obtained, that is, the mathematical model is The maximum error of the model can be controlled within 0.01% by verifying the model.

[0068] Further, from the properties of water and water vapor, the superheat degree refers to the degree that the steam temperature is higher than the saturation temperature under the corresponding pressure, and the superheat degree is equal to the difference between the steam temperature and the saturation temperature under the corresponding pressure, that is, the superheat degree mathematical model under different steam pressures and temperatures can be described as: Wherein, F(x, y) is the steam superheat degree (unit: ℃), t is the steam temperature (unit: ℃), and P is the steam pressure (unit: MPa).

[0069] Step S108, based on the superheat degree and the preset threshold, automatically control the opening and closing of the drain valve.

[0070] Specifically, based on the superheat degree and the preset threshold, the opening and closing of the drain valve of the boiler side steam pipeline, the drain valve of the turbine body, and the drain valve of the turbine side steam pipeline are automatically controlled.

[0071] Preferably, Figure 2 The control flow of the boiler side steam pipeline drain valve according to the embodiment of the present application is shown in FIG. 2, which includes: Figure 2

[0072] Based on the boiler side automatic opening logic (or logic), the drain valve of the boiler side steam pipeline is controlled to be opened, wherein the boiler side automatic opening logic is that the superheat degree at the drain valve of the boiler side steam pipeline is less than or equal to the preset threshold K2, and the opening operation is performed. If the steam turbine unit is a gas turbine unit, the gas turbine unit has a fuel purging system in addition to the coal-fired unit. During the combustion mode switching process of the gas turbine, the fuel purging system will use the exhaust gas of the compressor to purge the fuel main pipe. During the purging process, the temperature of the fuel main pipe will decrease. In order to avoid the condensation of steam after the temperature of the main pipe decreases after purging, the drain valve on the steam side of the steam pipeline should also be fully opened during the purging of the gas turbine, that is, the opening operation is also performed during the purging of the unit.

[0073] Based on the boiler side automatic closing logic (and logic & or logic), the drain valve of the boiler side steam pipeline is controlled to be closed, wherein the boiler side automatic closing logic is that the superheat degree at the drain valve of the boiler side steam pipeline is greater than or equal to the preset threshold K1, and the closing operation is performed; or the superheat degree increasing rate at the upstream position of the drain valve is greater than or equal to the preset threshold V1, and the superheat degree at the drain valve is greater than or equal to the preset threshold K1-△t, and the closing operation is performed.

[0074] ​​It should be noted that the preset threshold K1 is specifically the overheat degree value for closing the drain valve, preferably 50-60 DEG C, the preset threshold K2 is specifically the overheat degree value for opening the drain valve, preferably 25-35 DEG C, the preset threshold V1 is specifically the overheat degree increase rate value upstream of the drain valve, and the delta t in the preset threshold K1-delta t is specifically the steam overheat degree margin at the drain valve, the size of the delta t is related to the distance x from the upstream position of the drain valve to the drain valve, that is, delta t = Med [5, 0.02x, 10], wherein Med [] is a median function.

[0075] The beneficial effects are that the corresponding overheat degree is calculated in real time according to the drain pipe pressure and temperature, the segmented drain method is adopted, whether each section of the pipe needs to be drained is judged by the steam overheat degree at the drain valve and the overheat degree change rate upstream of the drain valve, the drain timing of each section of the pipe is ensured to be optimal, the opening and closing of the drain valve is accurately controlled, and full automatic control of all drain valves is realized.

[0076] Preferably, Figure 3 is a flowchart of the steam turbine body drain valve control according to the embodiments of the present application, as shown in the figure, the control flow includes: Figure 3

[0077] Based on the steam turbine body automatic opening logic, the drain valve of the steam turbine body is controlled to be opened, wherein the steam turbine body automatic opening logic is that the overheat degree at the drain valve of the steam turbine body is less than or equal to the preset threshold K4, and the opening operation is performed.

[0078] Based on the steam turbine body automatic closing logic, the drain valve of the steam turbine body is controlled to be closed, wherein the steam turbine body automatic closing logic is that the overheat degree at the drain valve of the steam turbine body is greater than or equal to the preset threshold K3, and the closing operation is performed.

[0079] It should be noted that the preset threshold K3 is specifically the overheat degree value for closing the drain valve, preferably 20-25 DEG C, and the preset threshold K4 is specifically the overheat degree value for opening the drain valve, preferably 25-30 DEG C

[0080] The beneficial effects are that the corresponding overheat degree is calculated in real time according to the steam turbine body cylinder pressure and the temperature before the drain valve, the segmented drain method is adopted, whether each section of the pipe needs to be drained is judged by the overheat degree, the drain timing of each section of the pipe is ensured to be optimal, the opening and closing of the drain valve is accurately controlled, and full automatic control of all drain valves is realized.

[0081] Preferably, Figure 4 is a flowchart of the steam turbine side steam pipe drain valve control according to the embodiments of the present application, as shown in the figure, the control flow includes: Figure 4

[0082] ​​The steam turbine side automatic opening logic (and logic) is used to control the opening of the steam turbine side steam pipeline drain valve, wherein the steam turbine side automatic opening logic is that the superheat degree at the steam turbine side steam pipeline drain valve is less than or equal to a preset threshold K7, the condenser vacuum is greater than or equal to a preset threshold K8, and the steam pressure is greater than or equal to a preset threshold K9, and the opening operation is performed;

[0083] The steam turbine side automatic closing logic (and logic & or logic) is used to control the closing of the steam turbine side steam pipeline drain valve, wherein the steam turbine side automatic closing logic is that the superheat degree at the steam turbine side steam pipeline drain valve is greater than or equal to a preset threshold K6, the condenser vacuum is greater than or equal to a preset threshold K5, or the superheat degree increasing rate at the upstream position of the drain valve is greater than a preset threshold V2, and the superheat degree at the drain valve is greater than a preset threshold K6-△t, and the closing operation is performed.

[0084] It should be noted that the preset threshold K5 is a condenser vacuum value for closing the drain valve, which is preferably 25 kPa to 30 kPa, the preset threshold K6 is a superheat degree value for closing the drain valve, which is preferably 20℃ to 25℃, the preset threshold K7 is a superheat degree value for opening the drain valve, which is preferably 20℃ to 30℃, the preset threshold K8 is a condenser vacuum value for opening the drain valve, which is preferably 15 kPa to 20 kPa, the preset threshold K9 is a minimum steam pressure value of the pipeline for opening the drain valve, which is preferably 0.2 MPa to 0.5 MPa, the preset threshold V2 is a superheat degree increasing rate value at the upstream position of the drain valve, which is preferably 2℃ / min to 3℃ / min, and the △t in the preset threshold K6-△t is a steam superheat degree margin at the drain valve, which is related to the distance x from the upstream position of the drain valve to the drain valve, i.e. △t=Med[5, 0.02x, 10], wherein Med[] is a median function.

[0085] The beneficial effects are that the corresponding superheat degree is calculated in real time according to the drain pipeline pressure and temperature, the influence of opening the drain valve on the condenser vacuum is considered, the segmented drain method is adopted, whether the drain is needed for each pipeline is determined by the steam superheat degree at the drain point, the superheat degree changing rate at the upstream position of the drain valve, and the condenser vacuum, the drain timing of each pipeline is ensured to be optimal, the opening and closing of the drain valve is accurately controlled, and the automatic control of all the drain valves is realized.

[0086] Further, Figure 5 is a flowchart of the control of the drain valve primary valve and the drain secondary valve according to the embodiments of the present application, as shown in the figure, the control flow includes: Figure 5 as shown in the figure, the control flow includes:

[0087] The boiler side, the steam turbine body, and the steam turbine side drain valve include a drain primary valve and a drain secondary valve.

[0088] In the case of performing the drain valve opening operation, the drain secondary valve is opened first, and when the drain secondary valve has been opened and the feedback trigger is triggered, the drain primary valve is opened.

[0089] In the case of performing the drain valve closing operation, the drain primary valve is closed first, and when the drain primary valve has been closed and the feedback trigger is triggered, the drain secondary valve is closed.

[0090] It should be noted that the boiler side, the turbine body and the turbine side have a drain primary valve and a drain secondary valve for pipeline drain valve control (the valve close to the main system pipeline side is a primary valve, and the valve close to the drain expansion vessel side is a secondary valve). The opening and closing of the two valves is controlled in a trapezoidal control mode to reduce the intensity of the primary valve being washed by the drain and to realize full automatic control of all drain valves.

[0091] Through steps S102 to S108 in the embodiment of the present application, the problem of how to realize full automatic, accurate and timely control of the drain in the thermal power generating unit is solved, full automatic control of the drain control system is realized, human judgment and operation of the operator is reduced, subjectivity and blindness of the drain operation are eliminated, the safety and automation level of the unit are improved, the drain valves on each pipeline are opened and closed at the best time, steam loss is reduced, and the operation efficiency of the unit is improved.

[0092] It should be noted that the steps shown in the above flow or the flowchart of the accompanying drawings can be executed in a computer system such as a set of computer executable instructions, and although a logical order is shown in the flowchart, in some cases, the steps shown or described can be executed in an order different from that shown here.

[0093] The embodiment of the present application provides a drain control system of a thermal power generating unit, Figure 6 is a structural block diagram of the drain control system of the thermal power generating unit according to the embodiment of the present application, as Figure 6 shown, the system comprises a data measurement module 61, a real-time operation module 62 and an execution control module 63;

[0094] The data measurement module 61 is used for measuring the steam pressure and steam temperature of the upstream position of the drain valve in each drain pipeline of the thermal power generating unit in real time through a temperature and pressure sensor.

[0095] The real-time operation module 62 is used for calculating the saturated steam temperature under the steam pressure in real time, and calculating the corresponding superheat degree according to the saturated steam temperature and the steam temperature.

[0096] The execution control module 63 is used for automatically controlling the opening and closing of the drain valve according to the superheat degree and a preset threshold value.

[0097] By the data measurement module 61, the real-time operation module 62 and the execution control module 63 in the embodiments of the present application, the problem of how to realize automatic, accurate and timely control of the whole drainage process in the thermal power generating unit is solved, the automatic control of the whole drainage control system is realized, the human judgment and operation of the operating personnel are reduced, the subjectivity and blindness of the drainage operation are eliminated, the safety and the automation level of the unit are improved, at the same time, the steam loss is reduced and the operation efficiency of the unit is improved.

[0098] It should be noted that each of the above modules can be a functional module or a program module, which can be implemented by software or hardware. For the modules implemented by hardware, each of the above modules can be located in the same processor, or each of the above modules can also be located in different processors in any combination.

[0099] The embodiment also provides an electronic device including a memory and a processor, the memory storing a computer program, and the processor being configured to execute the computer program to perform the steps in any of the method embodiments.

[0100] Optionally, the electronic device can further include a transmission device and an input / output device, wherein the transmission device is connected with the processor, and the input / output device is connected with the processor.

[0101] It should be noted that the specific examples in the embodiment can refer to the examples described in the above embodiments and optional implementation manners, and the embodiment will not be described here.

[0102] In addition, in combination with the drainage control method of the thermal power generating unit in the above embodiments, the embodiments of the present application can provide a storage medium for implementation. The storage medium stores a computer program; when the computer program is executed by a processor, any of the drainage control methods of the thermal power generating unit in the above embodiments is implemented.

[0103] In one embodiment, a computer device is provided, which can be a terminal. The computer device comprises a processor, a memory, a network interface, a display screen and an input device connected through a system bus. The processor of the computer device is configured to provide computing and control capabilities. The memory of the computer device comprises a non-volatile storage medium and an internal memory. The non-volatile storage medium stores an operating system and a computer program. The internal memory provides an environment for running the operating system and the computer program in the non-volatile storage medium. The network interface of the computer device is configured to communicate with an external terminal through a network connection. The computer program, when executed by the processor, implements a method for controlling steam drainage of a thermal power generating unit. The display screen of the computer device can be a liquid crystal display screen or an electronic ink display screen. The input device of the computer device can be a touch layer overlaid on the display screen, or a key, a trackball or a touchpad arranged on the housing of the computer device, or an external keyboard, touchpad or mouse.

[0104] In one embodiment, Figure 7 is a schematic diagram of an internal structure of an electronic device according to an embodiment of the present application, as Figure 7 shown, an electronic device is provided, which can be a server, and an internal structure diagram of the electronic device can be as Figure 7 shown. The electronic device comprises a processor, a network interface, an internal memory and a non-volatile memory connected through an internal bus, wherein the non-volatile memory stores an operating system, a computer program and a database. The processor is configured to provide computing and control capabilities, the network interface is configured to communicate with an external terminal through a network connection, the internal memory is configured to provide an environment for running the operating system and the computer program, the computer program, when executed by the processor, implements a method for controlling steam drainage of a thermal power generating unit, and the database is configured to store data.

[0105] Those skilled in the art can understand that Figure 7 the structure shown in the above embodiment is only a block diagram of part of the structure related to the scheme of the present application, and does not constitute a limitation on the electronic device to which the scheme of the present application is applied. Specifically, the electronic device can comprise more or fewer components than those shown in the diagram, or some components can be combined, or have a different arrangement of components.

[0106] Those skilled in the art can understand that all or part of the processes in the above-mentioned embodiment methods can be completed by instructing the relevant hardware through a computer program, and the computer program can be stored in a non-volatile computer readable storage medium. When the computer program is executed, it can include the processes of the above-mentioned embodiments of each method. Any reference to memory, storage, database or other medium used in each embodiment provided by the present application can include non-volatile and / or volatile memory. Non-volatile memory can include read-only memory (ROM), programmable ROM (PROM), electrically programmable ROM (EPROM), electrically erasable programmable ROM (EEPROM) or flash memory. Volatile memory can include random access memory (RAM) or external cache memory. As an illustration but not limitation, RAM is available in various forms, such as static RAM (SRAM), dynamic RAM (DRAM), synchronous DRAM (SDRAM), double data rate SDRAM (DDR SDRAM), enhanced SDRAM (ESDRAM), synchronous link (Synchlink) DRAM (SLDRAM), memory bus (Rambus) direct RAM (RDRAM), direct memory bus dynamic RAM (DRDRAM), and memory bus dynamic RAM (RDRAM), etc.

[0107] Those skilled in the art should understand that each technical feature of the above-mentioned embodiments can be combined arbitrarily, and in order to make the description simple, each technical feature in the above-mentioned embodiments is not described all possible combinations, however, as long as the combination of these technical features does not exist contradictory, it should be considered as the scope of the present application.

[0108] The above-mentioned embodiments only express several implementation manners of the present application, and the description is more specific and detailed, but it should not be understood as a limitation on the scope of the patent. It should be pointed out that for ordinary skilled in the art, without departing from the concept of the present application, a number of modifications and improvements can be made, which are all within the scope of the present application. Therefore, the scope of protection of the patent of the present application should be subject to the appended claims.

Claims

1. A method for controlling the drainage of a thermal power generating unit, characterized in that, The method includes: Temperature and pressure sensors are installed at the steam trap on the boiler side of the thermal power generating unit and at the upstream position of the steam trap. Temperature and pressure sensors are installed at the drain valve of the steam turbine body in the thermal power generator set, and at the upstream position of the drain valve. Temperature and pressure sensors are installed at the steam trap on the turbine side of the thermal power generator set and at the upstream position of the steam trap. The temperature and pressure sensors are used to measure the steam pressure and steam temperature at each steam trap and each upstream location in real time. The saturated steam temperature at the stated steam pressure is calculated in real time, and the corresponding superheat is calculated based on the saturated steam temperature and the steam temperature. Based on the superheat and preset threshold, the steam traps on / off of the boiler-side steam pipe, the steam turbine body, and the steam traps on / off of the turbine-side steam pipe are automatically controlled. The automatic control of the steam trap switching on the turbine side steam pipeline, based on the superheat and a preset threshold, includes: Based on the automatic opening logic of the steam turbine side, the steam trap of the steam pipeline on the steam turbine side is controlled to open. The automatic opening logic of the steam turbine side is to execute the opening operation when the superheat at the steam trap of the steam pipeline on the steam turbine side is less than or equal to a preset threshold K7, the condenser vacuum is greater than or equal to a preset threshold K8, and the steam pressure is greater than or equal to a preset threshold K9. Based on the turbine-side automatic shutdown logic, the steam traps of the turbine-side steam pipeline are controlled to close. The turbine-side automatic shutdown logic is as follows: if the superheat at the steam trap of the turbine-side steam pipeline is greater than or equal to a preset threshold K6, a shutdown operation is performed; or if the condenser vacuum is greater than or equal to a preset threshold K5, a shutdown operation is performed; or if the rate of increase of superheat at the upstream position of the steam trap is greater than a preset threshold V2, and the superheat at the steam trap is greater than a preset threshold K6-Δt, a shutdown operation is performed, where Δt is the steam superheat margin at the steam trap.

2. The method according to claim 1, characterized in that, Each drain valve includes a primary drain valve and a secondary drain valve; When performing the opening operation of each drain valve, the corresponding secondary drain valve is opened first. After the secondary drain valve is opened and feedback is triggered, the corresponding primary drain valve is opened. When performing the closing operation of each drain valve, the corresponding primary drain valve is closed first. After the primary drain valve is closed and feedback is triggered, the corresponding secondary drain valve is then closed.

3. The method according to claim 1, characterized in that, Real-time calculation of the saturated steam temperature at the stated steam pressure includes: Based on the Antoni equation, an equation relating steam pressure and saturated steam temperature is constructed. Based on this equation and the real-time measured steam pressure, the saturated steam temperature is calculated in real time.

4. The method according to claim 1 or 3, characterized in that, Real-time calculation of the saturated steam temperature at the stated steam pressure includes: Antoine's equations in water are known. ,in, A, B, and C are all constants, P is the steam pressure, K is the absolute temperature of the saturated steam at the corresponding pressure, and T is the saturated steam temperature at the corresponding pressure. Transform the Antoni equation into ,Right now , where a, b and c are coefficients to be determined; The least squares fitting formula Y=X*θ+E is used to obtain the coefficients a, b and c to be determined, where X is an n*k matrix, Y is an n*1 column vector, θ is an n*1 column vector of the coefficients to be determined, and E is an n*1 residual column vector. Based on the obtained coefficients a, b, and c, the real-time measured steam pressure, and the Antoine equation... The saturated steam temperature is calculated in real time.

5. The method according to claim 1, characterized in that, Based on the superheat and a preset threshold, the automatic control of the steam trap switching on the boiler side includes: Based on the boiler-side automatic opening logic, the steam trap of the boiler-side steam pipe is controlled to open. The boiler-side automatic opening logic is that when the superheat at the steam trap of the boiler-side steam pipe is less than or equal to a preset threshold K2, the opening operation is performed. Based on the boiler-side automatic shutdown logic, the steam trap of the boiler-side steam pipeline is controlled to close. The boiler-side automatic shutdown logic is as follows: if the superheat at the steam trap of the boiler-side steam pipeline is greater than or equal to a preset threshold K1, a shutdown operation is performed; or if the rate of increase of superheat at the upstream position of the steam trap is greater than or equal to a preset threshold V1, and the superheat at the steam trap is greater than or equal to a preset threshold K1-Δt, a shutdown operation is performed, where Δt is the steam superheat margin at the steam trap.

6. The method according to claim 1, characterized in that, Based on the superheat and a preset threshold, the automatic control of the steam turbine's drain valve switching includes: Based on the automatic opening logic of the steam turbine body, the steam trap of the steam turbine body is controlled to open. The automatic opening logic of the steam turbine body is that when the superheat at the steam trap of the steam turbine body is less than or equal to a preset threshold K4, the opening operation is performed. Based on the automatic shut-off logic of the turbine body, the drain valve of the turbine body is controlled to close. The automatic shut-off logic of the turbine body is executed when the superheat at the drain valve of the turbine body is greater than or equal to a preset threshold K3.

7. A drainage control system for a thermal power generating unit, characterized in that, The system includes a data measurement module, a real-time computing module, and an execution control module; Temperature and pressure sensors are installed at the steam trap on the boiler side of the thermal power generating unit and at the upstream position of the steam trap; temperature and pressure sensors are installed at the steam trap on the turbine body of the thermal power generating unit and at the upstream position of the steam trap; temperature and pressure sensors are installed at the steam trap on the turbine side of the thermal power generating unit and at the upstream position of the steam trap. The data measurement module is used to measure the steam pressure and steam temperature of each drain valve and its upstream position in real time in each drain pipe of the thermal power generator unit through temperature and pressure sensors. The real-time calculation module is used to calculate the saturated steam temperature under the steam pressure in real time, and calculate the corresponding superheat based on the saturated steam temperature and the steam temperature. The execution control module is used to automatically control the switching of the steam trap on the boiler side, the steam trap on the turbine body, and the steam trap on the turbine side based on the superheat and a preset threshold. The automatic control of the steam trap switching on the turbine side steam pipeline, based on the superheat and a preset threshold, includes: Based on the automatic opening logic of the steam turbine side, the steam trap of the steam pipeline on the steam turbine side is controlled to open. The automatic opening logic of the steam turbine side is to execute the opening operation when the superheat at the steam trap of the steam pipeline on the steam turbine side is less than or equal to a preset threshold K7, the condenser vacuum is greater than or equal to a preset threshold K8, and the steam pressure is greater than or equal to a preset threshold K9. Based on the turbine-side automatic shutdown logic, the steam traps of the turbine-side steam pipeline are controlled to close. The turbine-side automatic shutdown logic is as follows: if the superheat at the steam trap of the turbine-side steam pipeline is greater than or equal to a preset threshold K6, a shutdown operation is performed; or if the condenser vacuum is greater than or equal to a preset threshold K5, a shutdown operation is performed; or if the rate of increase of superheat at the upstream position of the steam trap is greater than a preset threshold V2, and the superheat at the steam trap is greater than a preset threshold K6-Δt, a shutdown operation is performed, where Δt is the steam superheat margin at the steam trap.

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