A method and system for obtaining exhaust steam parameters of a direct air-cooling unit

Abstract

The application discloses a kind of direct air cooling unit exhaust parameter acquisition method and system, obtain the exhaust enthalpy of direct air cooling unit;Based on the obtained exhaust enthalpy, the reference exhaust density is obtained by exhaust pressure;According to the obtained reference exhaust density, the exhaust pressure of the end of low-pressure cylinder last stage exhaust port to exhaust pipe horizontal section is measured, and the low-pressure cylinder exhaust flow and reference differential pressure are calibrated;According to the obtained low-pressure cylinder exhaust flow and reference differential pressure, the exhaust flow of any working condition is obtained, and the existing parameters are combined with indirect measurement means to obtain the exhaust parameters of direct air cooling unit, including exhaust flow, exhaust enthalpy;To improve the operation economy, reliability provides basis for unit.

Description

Technical Field

[0001] This invention belongs to the field of energy conservation and consumption reduction technology for coal-fired power units, specifically relating to a method and system for obtaining exhaust steam parameters of a direct air-cooled power unit. Background Technology

[0002] Direct air-cooled units utilize forced convection cooling of turbine exhaust steam by air-cooled fans to create a vacuum, and have been widely used in the coal-rich and water-scarce regions of northern my country. Due to the large number of fans and the large heat dissipation area of ​​the air-cooled condenser, the air-cooled fan flow rate and finned tube outlet temperature are almost impossible to obtain precisely. Therefore, the exhaust heat dissipation cannot be obtained from the air-cooled island, but only from the turbine exhaust end.

[0003] On the other hand, the exhaust steam flow rate of the steam turbine is generally obtained through measurement in accordance with ASME standards. However, in the actual operation of the unit, due to the large difference from the ASME standard test process, the exhaust steam parameters of the direct air-cooled unit cannot be directly obtained, which is extremely detrimental to the optimized operation of the cold end and the air-cooled antifreeze. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to provide a method and system for obtaining exhaust steam parameters of direct air-cooled units, which addresses the shortcomings of the prior art and solves the current technical problem of not being able to quickly obtain exhaust steam parameters of direct air-cooled units.

[0005] The present invention adopts the following technical solution:

[0006] A method for obtaining exhaust steam parameters of a direct air-cooled unit includes the following steps:

[0007] Obtain the exhaust enthalpy of the direct air-cooled unit;

[0008] Based on the obtained exhaust enthalpy, the baseline exhaust density is obtained through the exhaust pressure.

[0009] Based on the obtained baseline exhaust density, measure the exhaust pressure from the last stage exhaust port of the low-pressure cylinder to the end of the horizontal section of the exhaust pipe, and calibrate the low-pressure cylinder exhaust flow rate and the baseline pressure difference.

[0010] The exhaust flow rate under any operating condition can be obtained by comparing the low-pressure cylinder exhaust flow rate with the reference pressure difference.

[0011] Preferably, the exhaust enthalpy from the steam inlet to the exhaust from the low-pressure cylinder of the steam turbine is divided into:

[0012] Steam enters the low-pressure cylinder and flows to the extraction port. A portion of this steam is superheated. By measuring the steam inlet parameters and extraction parameters of the low-pressure cylinder, the corresponding flow efficiency η is determined. LH-6 ;

[0013] From the low-pressure cylinder extraction port to the exhaust port, the corresponding portion of the steam is wet steam. The difference between the flow efficiency from the low-pressure cylinder extraction port to the exhaust port and the flow efficiency from the low-pressure cylinder inlet to the extraction port is the moisture loss η. wet .

[0014] More preferably, the flow efficiency η LH-6 The calculation is as follows:

[0015]

[0016] Among them, h LH h6 is the enthalpy of the low-pressure cylinder inlet steam, h6 is the enthalpy of the No. 6 extraction steam, h * 6 represents the isentropic enthalpy of steam extracted from steam source number 6.

[0017] Moisture loss is denoted as η wet The calculation is as follows:

[0018] η wet =η LH-6 -η 6-ex

[0019] Where, η LH-6 η is the flow efficiency of steam entering the low-pressure cylinder through the No. 6 extraction port. 6-ex The flow efficiency from the No. 6 extraction port of the low-pressure cylinder to the exhaust port.

[0020] More preferably, the flow efficiency η of the steam inlet from the low-pressure cylinder to the No. 6 extraction port is... LH-6 The flow efficiency η from the extraction port of the low-pressure cylinder No. 6 to the exhaust port 6-ex The calculation is as follows:

[0021] η 6-ex =η LH-6 -7%

[0022]

[0023] Among them, h * ex For the isentropic enthalpy of exhaust steam, h ex For exhaust enthalpy.

[0024] Preferably, the reference exhaust density is uniquely determined by the exhaust enthalpy and exhaust pressure.

[0025] Preferably, the reference exhaust pressure loss Δp b The calculation is as follows:

[0026] Δp b =k(Q b / Aρ b ) 2

[0027] Where A is the cross-sectional area of ​​the exhaust pipe, k is a constant coefficient, and ρ b As the baseline exhaust density, Qb This refers to the exhaust steam flow rate under rated load.

[0028] Preferably, the exhaust steam flow rate Q is:

[0029]

[0030] Where A is the cross-sectional area of ​​the exhaust pipe, ρ is the exhaust steam density, Δp is the pressure loss of the steam pipe, and k is a coefficient.

[0031] Secondly, embodiments of the present invention provide a system for acquiring exhaust steam parameters of a direct air-cooled unit, comprising:

[0032] The data module obtains the exhaust enthalpy of the direct air-cooled unit;

[0033] The baseline module obtains the baseline exhaust density based on the exhaust enthalpy obtained from the data module and the exhaust pressure.

[0034] The measurement module measures the exhaust pressure from the last stage exhaust port of the low-pressure cylinder to the end of the horizontal section of the exhaust pipe, based on the reference exhaust density obtained from the reference module, and calibrates the exhaust flow rate of the low-pressure cylinder and the reference pressure difference.

[0035] The output module obtains the exhaust flow rate under any operating condition based on the low-pressure cylinder exhaust flow rate obtained from the measurement module and the reference pressure difference.

[0036] Thirdly, a chip includes a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the computer program to implement the steps of the above-described method for obtaining exhaust steam parameters of a direct air-cooled unit.

[0037] Fourthly, embodiments of the present invention provide an electronic device, including a computer program, which, when executed by the electronic device, implements the steps of the above-described method for obtaining exhaust steam parameters of a direct air-cooled unit.

[0038] Compared with the prior art, the present invention has at least the following beneficial effects:

[0039] A method for obtaining exhaust steam parameters of a direct air-cooled unit. The exhaust steam flow rate of a steam turbine unit generally cannot be directly measured. However, since there is pressure loss from the exhaust port to the exhaust pipe of the air-cooled steam turbine, and the pressure loss is proportional to the square of the exhaust steam velocity, the exhaust steam flow rate can be obtained in real time by using this relationship and in conjunction with the exhaust steam density calculation.

[0040] Furthermore, the steam entering the low-pressure cylinder and exiting the sixth stage is generally superheated steam, and its flow efficiency can be obtained in real time from the steam entering parameters (temperature, pressure) and the sixth stage extraction parameters (temperature, pressure). The steam exiting the sixth stage and exiting the low-pressure cylinder is in the wet steam zone. Since the humidity of the exhaust steam cannot be measured, its flow efficiency cannot be directly calculated. It needs to be obtained indirectly by subtracting the wet steam loss from the aforementioned flow efficiency. By obtaining this part of the flow efficiency, the exhaust steam enthalpy and exhaust steam density can be calculated.

[0041] Furthermore, the exhaust pressure loss is proportional to the square of the exhaust velocity; therefore, it is necessary to calculate the exhaust density to obtain the corresponding relationship between exhaust pressure loss and exhaust flow rate. The exhaust density is uniquely derived from the exhaust enthalpy and exhaust pressure. The exhaust enthalpy is obtained through calculation, while the exhaust pressure is obtained directly through measurement.

[0042] Furthermore, by using the reference pressure loss and reference exhaust velocity, the conversion coefficient k between pressure loss and velocity can be obtained, and this coefficient is applicable to any operating condition.

[0043] Furthermore, the exhaust steam flow rate of the steam turbine unit is one of the key parameters, playing a decisive role in the economic efficiency and reliability of the cold-end system. However, the exhaust steam flow rate is difficult to obtain through actual measurement. Using this method, the exhaust steam flow rate can be calculated in real time based on the relationship between the exhaust steam flow rate and the exhaust steam pressure loss, while meeting engineering accuracy requirements.

[0044] It is understood that the beneficial effects of the second to fourth aspects mentioned above can be found in the relevant descriptions in the first aspect mentioned above, and will not be repeated here.

[0045] In summary, this invention indirectly obtains the exhaust steam flow rate by using the positive correlation between exhaust steam pressure loss and the square of exhaust steam velocity, and by calculating the exhaust steam enthalpy and exhaust steam density based on engineering-acceptable wet steam loss.

[0046] The technical solution of the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. Attached Figure Description

[0047] Figure 1 This is a schematic diagram of the process of the present invention;

[0048] Figure 2 A schematic diagram of a computer device provided in an embodiment of the present invention;

[0049] Figure 3 This is a block diagram of a chip provided according to an embodiment of the present invention. Detailed Implementation

[0050] 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.

[0051] 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.

[0052] 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.

[0053] 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.

[0054] 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.

[0055] 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)."

[0056] 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.

[0057] This invention provides a method for obtaining exhaust steam parameters of a direct air-cooled unit. Since the exhaust steam flow rate and exhaust steam enthalpy parameters of a steam turbine unit cannot be obtained directly, it is detrimental to unit operation monitoring and improving the unit's operating economy and reliability. This invention obtains the exhaust steam parameters of a direct air-cooled unit, including exhaust steam flow rate and exhaust steam enthalpy, through existing parameters combined with indirect measurement methods, providing a basis for improving the unit's operating economy and reliability.

[0058] Please see Figure 1 The present invention provides a method for obtaining exhaust steam parameters of a direct air-cooled unit, comprising the following steps:

[0059] S1, Obtain exhaust enthalpy;

[0060] The low-pressure cylinder of the direct air-cooled unit is equipped with three stages of non-adjustable regenerative steam extraction, which supplies low-pressure heaters No. 5, No. 6, and No. 7 according to the pressure from high to low.

[0061] Among them, the steam extracted from low-pressure heaters No. 5 and No. 6 is superheated steam, and its steam enthalpy is uniquely determined by both temperature and pressure values, which can be obtained directly by measuring temperature and pressure.

[0062] The extracted steam from the No. 7 low-pressure heater has entered the wet steam zone, and its steam enthalpy is determined by the pressure and steam humidity, but the steam humidity cannot be measured; similarly, the exhaust steam enthalpy of the low-pressure cylinder is also wet steam, and the exhaust steam enthalpy cannot be directly measured.

[0063] Steam enters the low-pressure cylinder through the medium-low pressure connecting pipe. The inlet steam pressure and temperature are denoted as p, respectively. LH ,T LH ,

[0064] The pressure and temperature of extraction steam at No. 5 are denoted as p5 and T5, respectively.

[0065] The extraction steam pressure and temperature of No. 6 are denoted as p6 and T6, respectively.

[0066] Pressure No. 7 and exhaust pressure are denoted as p7, p ex All the data listed above are actual data that can be directly measured.

[0067] The steam flow from the low-pressure cylinder of the steam turbine to the exhaust steam is divided into the following two parts:

[0068] Part 1: Steam from the low-pressure cylinder to extraction port 6. This part of the steam is all superheated steam. The flow efficiency of this part is calculated by measuring the steam inlet parameters of the low-pressure cylinder and the extraction port 6. The specific calculation is as follows:

[0069]

[0070] Among them, h LH For the enthalpy of the low-pressure cylinder inlet steam, by p LH ,T LH Calculations show that h6 is the enthalpy of extraction steam at position 6, obtained from p6 and T6. * 6 represents the isentropic enthalpy of steam extracted at position 6, derived from p. LH ,T LH The result was obtained from p6.

[0071] The calculation method is a conventional method.

[0072] Part Two: Steam from the No. 6 extraction port of the low-pressure cylinder to the exhaust port. This part of the steam is wet steam, which cannot be obtained by measuring steam parameters; however, it can be obtained indirectly, and the accuracy meets engineering requirements. The flow efficiency in the wet steam zone is significantly lower than that in the superheated steam zone. Based on extensive data measurement, the difference between the flow efficiency from the No. 6 extraction port to the exhaust port of the low-pressure cylinder and the flow efficiency from the steam inlet to the No. 6 extraction port of the low-pressure cylinder is the moisture loss, denoted as η. wet The specific calculations are as follows:

[0073] η wet =η LH-6 -η 6-ex

[0074] Where, η LH-6 η represents the flow efficiency from the low-pressure cylinder inlet to the No. 6 extraction port. 6-ex The flow efficiency from the No. 6 extraction port to the exhaust port of the low-pressure cylinder, under the current engineering-allowed accuracy conditions for large-capacity direct air-cooled units, is taken as η. wet =7%, then:

[0075] η 6-ex =η LH-6 -7% (2)

[0076]

[0077] Among them, h * ex For the isentropic enthalpy of exhaust steam, given p6, T6, p ex The calculation yields h ex The exhaust enthalpy is unknown and can be obtained by combining equations (1), (2) and (3).

[0078] h exTo obtain the final exhaust enthalpy, it is obviously possible to obtain it by simultaneously solving equations (1), (2), and (3):

[0079] h ex =h6-(η) LH-6 -7%)(h ex -h * ex S2, Obtain other exhaust parameters;

[0080] Obtain exhaust enthalpy h ex Then, through the exhaust pressure p ex That is, the exhaust steam density ρ is obtained, and the exhaust steam density ρ is uniquely determined by the exhaust steam enthalpy and exhaust steam pressure.

[0081] Calibrling the exhaust flow rate mainly involves calibrating the exhaust velocity, which depends on calculating the exhaust density of the low-pressure cylinder. This depends on step S1, which obtains the exhaust enthalpy and exhaust pressure. The exhaust pressure loss is obtained independently of steps S1 and S2.

[0082] S3. Calibrate the low-pressure cylinder exhaust flow rate and reference pressure difference;

[0083] The low-pressure cylinder exhaust flow rate is obtained through experimental measurement, and is generally taken as the exhaust flow rate Q under rated load. b The baseline exhaust gas density ρ is obtained based on steps S1 and S2. b The pressure difference between the exhaust port of the last stage of the low-pressure cylinder and the end of the horizontal section of the exhaust pipe is the reference exhaust pressure loss Δp. b The specific calculations are as follows:

[0084] Δp b =k(Q b / Aρ b ) 2 (4)

[0085] Where A is the cross-sectional area of ​​the exhaust pipe, and k is a constant coefficient, obtained by calibration from Equation 4.

[0086] To obtain the exhaust steam flow rate under any operating condition, a constant coefficient k is required. Under any operating condition, the constant coefficient k remains unchanged. Therefore, the exhaust steam velocity under any operating condition can be calculated by using the coefficient k obtained through calibration. Combined with the exhaust steam density under any operating condition, the exhaust steam flow rate can be obtained.

[0087] S4. Obtain the exhaust steam flow rate under any operating condition.

[0088] The exhaust steam from the low-pressure cylinder enters the air-cooled island through the exhaust pipe. The pressure difference between the exhaust steam pressure at the last stage exhaust port of the low-pressure cylinder and the end of the horizontal section of the exhaust pipe is the exhaust steam pressure loss. The steam pipe pressure loss Δp is proportional to the square of the flow velocity.

[0089]

[0090] The constant coefficient k is obtained from equation 4.

[0091] The exhaust steam flow rate Q is:

[0092] Q=Avρ

[0093] Among them, the exhaust steam density ρ is obtained from steps S1 and S2, and A is the cross-sectional area of ​​the exhaust steam pipe (design value).

[0094] The exhaust steam flow rate Q is:

[0095]

[0096] Therefore, the exhaust steam flow rate can be obtained based on the measured value.

[0097] In another embodiment of the present invention, a system for acquiring exhaust steam parameters of a direct air-cooled unit is provided. This system can be used to implement the above-mentioned method for acquiring exhaust steam parameters of a direct air-cooled unit. Specifically, the system for acquiring exhaust steam parameters of a direct air-cooled unit includes a data module, a reference module, a measurement module, and an output module.

[0098] The data module acquires the exhaust enthalpy of the direct air-cooled unit.

[0099] The baseline module obtains the baseline exhaust density based on the exhaust enthalpy obtained from the data module and the exhaust pressure.

[0100] The measurement module measures the exhaust pressure from the last stage exhaust port of the low-pressure cylinder to the end of the horizontal section of the exhaust pipe, based on the reference exhaust density obtained from the reference module, and calibrates the exhaust flow rate of the low-pressure cylinder and the reference pressure difference.

[0101] The output module obtains the exhaust flow rate under any operating condition based on the low-pressure cylinder exhaust flow rate obtained from the measurement module and the reference pressure difference.

[0102] In another embodiment of the present invention, a terminal device is provided, comprising a processor and a memory. The memory stores a computer program, which includes program instructions. The processor executes the program instructions stored in the computer storage medium. The processor may be a Central Processing Unit (CPU), or other general-purpose processors, digital signal processors (DSPs), application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. It is the computing and control core of the terminal, suitable for implementing one or more instructions, specifically suitable for loading and executing one or more instructions to achieve a corresponding method flow or corresponding function. The processor described in this embodiment of the present invention can be used in the operation of a method for obtaining exhaust steam parameters of a direct air-cooled unit, including:

[0103] Obtain the exhaust enthalpy of the direct air-cooled unit; based on the obtained exhaust enthalpy, obtain the reference exhaust density through the exhaust pressure; according to the obtained reference exhaust density, measure the exhaust pressure from the last stage exhaust port of the low-pressure cylinder to the end of the horizontal section of the exhaust pipe, and calibrate the low-pressure cylinder exhaust flow rate and the reference pressure difference; according to the obtained low-pressure cylinder exhaust flow rate and the reference pressure difference, obtain the exhaust flow rate under any operating condition.

[0104] Please see Figure 2 The terminal device is a computer device. In this embodiment, the computer device 60 includes a processor 61, a memory 62, and a computer program 63 stored in the memory 62 and executable on the processor 61. When executed by the processor 61, the computer program 63 implements the fluid composition calculation method in the reservoir stimulation wellbore of this embodiment. To avoid repetition, details are omitted here. Alternatively, when executed by the processor 61, the computer program 63 implements the functions of each model / unit in the direct air-cooled unit exhaust parameter acquisition system of this embodiment. To avoid repetition, details are omitted here.

[0105] Computer device 60 can be a desktop computer, laptop, handheld computer, cloud server, or other computing device. Computer device 60 may include, but is not limited to, a processor 61 and a memory 62. Those skilled in the art will understand that... Figure 2 This is merely an example of computer device 60 and does not constitute a limitation on computer device 60. It may include more or fewer components than shown, or combine certain components, or different components. For example, computer device may also include input / output devices, network access devices, buses, etc.

[0106] The processor 61 may be a Central Processing Unit (CPU), or other general-purpose processors, digital signal processors (DSPs), application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. A general-purpose processor may be a microprocessor or any conventional processor.

[0107] The memory 62 can be an internal storage unit of the computer device 60, such as a hard disk or RAM of the computer device 60. The memory 62 can also be an external storage device of the computer device 60, such as a plug-in hard disk, smart media card (SMC), secure digital (SD) card, flash card, etc. equipped on the computer device 60.

[0108] Furthermore, the memory 62 may include both internal storage units of the computer device 60 and external storage devices. The memory 62 is used to store computer programs and other programs and data required by the computer device. The memory 62 can also be used to temporarily store data that has been output or will be output.

[0109] Please see Figure 3 The terminal device is a chip. In this embodiment, the chip 600 includes a processor 622, which may be one or more, and a memory 632 for storing computer programs executable by the processor 622. The computer program stored in the memory 632 may include one or more modules, each corresponding to a set of instructions. Furthermore, the processor 622 may be configured to execute the computer program to perform the above-described method for obtaining exhaust steam parameters of a direct air-cooled unit.

[0110] Additionally, chip 600 may also include a power supply component 626 and a communication component 650. The power supply component 626 can be configured to perform power management of chip 600, and the communication component 650 can be configured to enable communication of chip 600, such as wired or wireless communication. Furthermore, chip 600 may also include an input / output interface 658. Chip 600 can operate on an operating system stored in memory 632.

[0111] In another embodiment of the present invention, a storage medium is provided, specifically a computer-readable storage medium, which is a memory device in a terminal device for storing programs and data. It is understood that the computer-readable storage medium here can include both the built-in storage medium in the terminal device and extended storage media supported by the terminal device. The computer-readable storage medium provides storage space that stores the terminal's operating system. Furthermore, the storage space also stores one or more instructions suitable for loading and execution by a processor; these instructions can be one or more computer programs. It should be noted that the computer-readable storage medium here can be high-speed RAM or non-volatile memory, such as at least one disk storage device.

[0112] One or more instructions stored in a computer-readable storage medium can be loaded and executed by a processor to implement the corresponding steps of the method for obtaining exhaust steam parameters of a direct air-cooled unit in the above embodiments; one or more instructions in the computer-readable storage medium are loaded and executed by the processor to perform the following steps:

[0113] Obtain the exhaust enthalpy of the direct air-cooled unit; based on the obtained exhaust enthalpy, obtain the reference exhaust density through the exhaust pressure; according to the obtained reference exhaust density, measure the exhaust pressure from the last stage exhaust port of the low-pressure cylinder to the end of the horizontal section of the exhaust pipe, and calibrate the low-pressure cylinder exhaust flow rate and the reference pressure difference; according to the obtained low-pressure cylinder exhaust flow rate and the reference pressure difference, obtain the exhaust flow rate under any operating condition.

[0114] 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.

[0115] Example

[0116] Calibration results at 600MW load:

[0117]

[0118]

[0119] The calculation results under the calibration conditions are as follows: The final pressure-flow conversion coefficient k is obtained.

[0120]

[0121] For a certain 600MW direct air-cooled unit, the measurement data under any operating condition is as follows:

[0122]

[0123]

[0124] The methods for calculating exhaust enthalpy and exhaust density are the same as those for calibration conditions, and will not be repeated here.

[0125] The exhaust steam flow rate is obtained from the flow rate-pressure loss coefficient k obtained under the calibration conditions.

[0126] In summary, this invention provides a method and system for obtaining exhaust steam parameters of a direct air-cooled unit. By utilizing existing parameters and combining them with indirect measurement methods, it obtains the exhaust steam parameters of the direct air-cooled unit, including exhaust steam flow rate, exhaust steam enthalpy, etc. This provides a basis for improving the unit's operational economy and reliability. The accuracy fully meets engineering requirements.

[0127] Those skilled in the art will clearly understand that, for the sake of convenience and brevity, the above-described division of functional units and modules is merely an example. In practical applications, the above functions can be assigned to different functional units and modules as needed, that is, the internal structure of the device can be divided into different functional units or modules to complete all or part of the functions described above. The functional units and modules in the embodiments can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit. The integrated unit can be implemented in hardware or as a software functional unit. Furthermore, the specific names of the functional units and modules are only for easy differentiation and are not intended to limit the scope of protection of this application. The specific working process of the units and modules in the above system can be referred to the corresponding process in the foregoing method embodiments, and will not be repeated here.

[0128] In the above embodiments, the descriptions of each embodiment have different focuses. For parts that are not described in detail or recorded in a certain embodiment, please refer to the relevant descriptions of other embodiments.

[0129] Those skilled in the art will recognize that the units and algorithm steps of the various examples described in conjunction with the embodiments disclosed in this invention can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are implemented in hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementations should not be considered beyond the scope of this invention.

[0130] In the embodiments provided by this invention, it should be understood that the disclosed devices / terminals and methods can be implemented in other ways. For example, the device / terminal embodiments described above are merely illustrative. For instance, the division of modules or units is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the coupling or direct coupling or communication connection shown or discussed may be through some interfaces; the indirect coupling or communication connection between devices or units may be electrical, mechanical, or other forms.

[0131] The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the units can be selected to achieve the purpose of this embodiment according to actual needs.

[0132] Furthermore, the functional units in the various embodiments of the present invention can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit. The integrated unit can be implemented in hardware or as a software functional unit.

[0133] If the integrated module / unit is implemented as a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, all or part of the processes in the methods of the above embodiments can also be implemented by a computer program instructing related hardware. The computer program can be stored in a computer-readable storage medium, and when executed by a processor, it can implement the steps of the various method embodiments described above. The computer program includes computer program code, which can be in the form of source code, object code, executable files, or certain intermediate forms. The computer-readable medium can include: any entity or device capable of carrying the computer program code, recording media, USB flash drives, portable hard drives, magnetic disks, optical disks, computer memory, read-only memory (ROM), random-access memory (RAM), electrical carrier signals, telecommunication signals, and software distribution media, etc. It should be noted that the content included in the computer-readable medium can be appropriately added or removed according to the requirements of legislation and patent practice in the jurisdiction. For example, in some jurisdictions, according to legislation and patent practice, computer-readable media do not include electrical carrier signals and telecommunication signals.

[0134] This application is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus, 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.

[0135] 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.

[0136] 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.

[0137] The above content is only for illustrating the technical concept of the present invention and should not be construed as limiting the scope of protection of the present invention. Any modifications made to the technical solution based on the technical concept proposed in this invention shall fall within the scope of protection of the claims of this invention.

Claims

1. A method for obtaining exhaust steam parameters of a direct air-cooled unit, characterized in that, Includes the following steps: Obtain the exhaust enthalpy of the direct air-cooled unit. The exhaust enthalpy is divided into: Steam enters the low-pressure cylinder and flows to the extraction port. A portion of this steam is superheated. The corresponding flow efficiency is determined by measuring the steam inlet and extraction parameters of the low-pressure cylinder. Flow efficiency The calculation is as follows: in, h LH The enthalpy of the steam entering the low-pressure cylinder. h 6 represents the enthalpy of extraction steam at position 6. h 6 represents the isentropic enthalpy of steam extracted from No.

6. From the low-pressure cylinder extraction port to the exhaust port, the corresponding portion of the steam is wet steam. The difference between the flow efficiency from the low-pressure cylinder extraction port to the exhaust port and the flow efficiency from the low-pressure cylinder inlet to the extraction port is the moisture loss. η wet Moisture loss is recorded as η wet The calculation is as follows: η wet = η LH-6 -η 6-ex in, η LH-6 The flow efficiency of steam entering the low-pressure cylinder through the No. 6 extraction port is determined. η 6-ex The flow efficiency from the No. 6 extraction port of the low-pressure cylinder to the exhaust port; Low-pressure cylinder steam inlet to No. 6 extraction port flow efficiency η LH-6 And the flow efficiency from the No. 6 extraction port of the low-pressure cylinder to the exhaust port η 6-ex The calculation is as follows: η 6-ex =η LH-6 -7% in, h ex The isentropic enthalpy of exhaust steam. h ex For exhaust enthalpy; Based on the obtained exhaust enthalpy, the reference exhaust density is obtained through the exhaust pressure. Using the obtained reference exhaust density, the exhaust pressure from the last stage exhaust port of the low-pressure cylinder to the end of the horizontal section of the exhaust pipe is measured, and the low-pressure cylinder exhaust flow rate and the reference exhaust pressure loss are calibrated. The reference exhaust pressure loss... Δp b The calculation is as follows: Δp b =k(Q b / Aρ b ） 2 in, A This is the cross-sectional area of ​​the exhaust pipe. k The constant coefficients, ρ b Based on the exhaust density, Q b This refers to the exhaust steam flow rate under rated load. This allows us to obtain the exhaust steam flow rate under any operating condition. Q for: in, This is the cross-sectional area of ​​the exhaust pipe. The exhaust gas density is equal to the reference exhaust gas density. For steam pipeline pressure loss, is a coefficient.

2. The method for obtaining exhaust steam parameters of a direct air-cooled unit according to claim 1, characterized in that, The baseline exhaust density is uniquely determined by the exhaust enthalpy and exhaust pressure.

3. A system for acquiring exhaust steam parameters of a direct air-cooled unit, characterized in that, include: The data module acquires the exhaust enthalpy of the direct air-cooled unit. The exhaust enthalpy is divided into: Steam enters the low-pressure cylinder and flows to the extraction port. A portion of this steam is superheated. The corresponding flow efficiency is determined by measuring the steam inlet and extraction parameters of the low-pressure cylinder. Flow efficiency The calculation is as follows: in, h LH The enthalpy of the steam entering the low-pressure cylinder. h 6 represents the enthalpy of extraction steam at position 6. h 6 represents the isentropic enthalpy of steam extracted from No.

6. From the low-pressure cylinder extraction port to the exhaust port, the corresponding portion of the steam is wet steam. The difference between the flow efficiency from the low-pressure cylinder extraction port to the exhaust port and the flow efficiency from the low-pressure cylinder inlet to the extraction port is the moisture loss. η wet Moisture loss is recorded as η wet The calculation is as follows: η wet = η LH-6 -η 6-ex in, η LH-6 The flow efficiency of steam entering the low-pressure cylinder through the No. 6 extraction port is determined. η 6-ex The flow efficiency from the No. 6 extraction port of the low-pressure cylinder to the exhaust port; Low-pressure cylinder steam inlet to No. 6 extraction port flow efficiency η LH-6 And the flow efficiency from the No. 6 extraction port of the low-pressure cylinder to the exhaust port η 6-ex The calculation is as follows: η 6-ex =η LH-6 -7% in, h ex The isentropic enthalpy of exhaust steam. h ex For exhaust enthalpy; The reference module, based on the exhaust enthalpy obtained from the data module, obtains the reference exhaust density through the exhaust pressure. The measurement module, based on the obtained reference exhaust density, measures the exhaust pressure from the last-stage exhaust port of the low-pressure cylinder to the end of the horizontal section of the exhaust pipe, calibrating the low-pressure cylinder exhaust flow rate and the reference exhaust pressure loss. The reference exhaust pressure loss... Δp b The calculation is as follows: Δp b =k(Q b / Aρ b ） 2 in, A This is the cross-sectional area of ​​the exhaust pipe. k The constant coefficients, ρ b Based on the exhaust density, Q b This refers to the exhaust steam flow rate under rated load. The output module obtains the exhaust steam flow rate under any operating condition. Q for: in, This is the cross-sectional area of ​​the exhaust pipe. The exhaust gas density is equal to the reference exhaust gas density. For steam pipeline pressure loss, is a coefficient.

4. A chip, characterized in that, A memory on which computer programs are stored; A processor for executing the computer program in the memory to implement the steps of the method of claim 1 or 2.

5. An electronic device, characterized in that, Includes the chip as described in claim 4.

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