Steam turbine unit sliding pressure optimization method, device, equipment, and storage medium

Abstract

The present invention proposes a method, device, equipment, and storage medium for optimizing the sliding pressure of a steam turbine unit. The method collects comprehensive thermal performance test data of the steam turbine unit to perform a first parameter correction calculation, obtains the first corrected steam turbine output and heat rate, and calculates the first corrected heat absorption, thereby determining the back pressure value, circulating water flow rate, and circulating water outlet temperature of the steam turbine unit. Based on the power of the circulating water pump motor of the steam turbine unit, the net heat rate of the steam turbine unit corresponding to different main steam pressure conditions is compared. The main steam pressure corresponding to the main steam pressure condition with the lowest net heat rate is the optimal main steam pressure of the steam turbine unit sliding pressure. Through the present invention, the influence of the main steam pressure of the steam turbine on the economic efficiency of the unit can be accurately evaluated, thereby providing reliable technical data for the operation of the unit, further reducing the net heat rate of the thermal power unit, and improving the efficiency of the power plant.

Description

Technical Field

[0001] The present invention relates to the technical field of thermal power steam turbine units, and in particular to a method, device, equipment and storage medium for optimizing the sliding pressure of a steam turbine unit. Background Art

[0002] During the daily operation of thermal power generating units, the main steam pressure of the units has a very important influence on the economy of the turbine. However, for turbine generating units with different parameters and different types, the same change in the main steam pressure of the units leads to different changes in the heat rate. Therefore, it is necessary to accurately obtain the influencing factors of the main steam pressure of the units on the heat rate of the turbine through the turbine sliding pressure optimization test.

[0003] The turbine sliding pressure optimization test requires that the turbine output be kept constant while other boundary parameters remain unchanged, and thermal performance tests are carried out under different main steam pressure conditions to determine the unit heat rate. However, in the actual test process, due to the influence of circulating water temperature, fluctuations in internal equipment parameters of the unit, etc., it is difficult to keep the turbine output constant while other parameters remain unchanged during the test. Therefore, during the test, it is necessary to try to correct the unit output under different main steam pressure conditions to the same value, and finally calculate the change in the net heat rate of the unit under different main steam pressure conditions. Summary of the invention

[0004] The present invention provides a method, device, equipment and storage medium for optimizing the sliding pressure of a steam turbine unit, which is intended to accurately evaluate the impact of the main steam pressure of the steam turbine on the economic efficiency of the unit, thereby providing reliable technical data for the operation of the unit, further reducing the net heat consumption rate of the thermal power unit and improving the efficiency of the power plant.

[0005] To this end, a first object of the present invention is to provide a method for optimizing the sliding pressure of a steam turbine unit, comprising:

[0006] Extracting the thermal performance test data of the steam turbine unit, performing a first correction on the main steam temperature and the reheat steam temperature of the steam turbine unit at the same load point and different main steam pressure conditions, and determining the output, heat rate and heat absorption of the steam turbine unit after the first correction based on the main steam temperature and the reheat steam temperature obtained after the first correction;

[0007] The main steam pressure condition is designated as a reference, a second correction is performed on the steam turbine unit output under the main steam pressure condition outside the reference, and when the steam turbine unit output obtained by the second correction is equal to the steam turbine unit output obtained by the first correction, a value of the steam turbine unit back pressure under the main steam pressure condition outside the reference is determined;

[0008] The circulating water temperature of the steam turbine unit under the main steam pressure condition outside the benchmark is set to be equal to the circulating water temperature of the steam turbine unit under the benchmark main steam pressure condition, and based on the back pressure value of the steam turbine unit under the main steam pressure condition outside the benchmark, the circulating water flow rate and circulating water outlet temperature under each main steam pressure condition outside the benchmark are determined, and the circulating water pump motor power of the steam turbine unit under the main steam pressure condition outside the benchmark is determined;

[0009] The net heat rate of the steam turbine unit is determined based on the heat absorption of the steam turbine unit obtained after the first correction, and the net heat rates of the steam turbine unit corresponding to different main steam pressure conditions are compared. The main steam pressure corresponding to the main steam pressure condition with the lowest net heat rate is the optimal sliding pressure main steam pressure of the steam turbine unit.

[0010] Among them, the thermal performance test data of the steam turbine unit at least include the condensate flow rate, main steam and reheat steam parameters, extraction parameters, heater inlet parameters, condensate and feed water parameters, turbine back pressure and generator power of the steam turbine unit; the inlet and outlet temperatures of the condenser circulating water, the circulating water flow rate, and the hot well water temperature; the inlet and outlet pressures of the circulating water pump, the outlet flow rate of the circulating water pump, and the motor power of the circulating water pump; the exhaust flow rate and exhaust enthalpy of the steam turbine; the cleanliness coefficient and overall heat transfer coefficient of the condenser; and the thermal characteristic curve of the circulating water pump.

[0011] The step of performing a first correction on the main steam temperature and the reheat steam temperature of the steam turbine unit at the same load point and different main steam pressure conditions, and determining the first corrected output, heat rate and heat absorption of the steam turbine unit based on the main steam temperature and the reheat steam temperature obtained after the first correction, comprises:

[0012] Performing a first correction on the main steam temperature and the reheat steam temperature at the same load point and different main steam pressure conditions to correct them to the design values;

[0013] The output and heat rate of the steam turbine unit after the first correction are calculated, and the heat absorption amount of the steam turbine unit after the first correction is calculated.

[0014] Wherein, the first corrected steam turbine unit output = steam turbine unit output test value / (1+main steam temperature to power change rate) / (1+reheat steam temperature to power change rate);

[0015] The first corrected steam turbine unit heat rate = steam turbine unit heat rate test value / (1 + main steam temperature to heat rate change rate) / (1 + reheat steam temperature to heat rate change rate);

[0016] The first corrected steam turbine unit heat absorption=the first corrected steam turbine unit output×the first corrected steam turbine unit heat rate.

[0017] Among them, when determining the back pressure value of the steam turbine unit under the main steam pressure condition outside the benchmark, it includes:

[0018] Based on the steam turbine unit output obtained after the second correction, the adjacent power change rate is calculated;

[0019] Power change rate = (WN-1-WN) / WN

[0020] Among them, after the second correction, the steam turbine output under different main steam pressure conditions is W1, W2, W3...WN; according to the characteristic curve of steam turbine back pressure to unit output, the power change rate corresponding to the back pressure PN* is obtained;

[0021] PN*=(PN+PN-1)-back pressure design value

[0022] Among them, under different operating conditions at the same load point, the main steam pressure of the unit is MP1, MP2, MP3...MPN, and the corresponding back pressure is P1, P2, P3...PN.

[0023] The step of determining the circulating water flow rate and circulating water outlet temperature under each main steam pressure condition outside the corresponding benchmark includes:

[0024] Under different main steam pressure conditions, the corresponding circulating water inlet temperature is T i 1. T i 2. T i 3……T i N; corresponding circulating water outlet temperature is T o 1. T o 2. T o 3……T o N; the circulating water flow rates are M1, M2, M3...MN respectively, and the power of the circulating water pump is W CP 1. W CP 2. W CP 3……W CP N; Except MP1 operating point, set the circulating water temperature of other operating points to T i 1;

[0025] Calculate the condenser heat load based on the condenser cleanliness factor and overall heat transfer coefficient;

[0026] Q=MN·C P ·(T o NT i N)

[0027] Where, Q represents the condenser heat load, C P It indicates the specific heat of the test circulating water at the average water temperature;

[0028] The overall heat transfer coefficient formula is expressed as:

[0029]

[0030] Where K represents the overall heat transfer coefficient; A represents the effective overall heat transfer area of ​​the condenser; Δt m represents the logarithmic mean temperature difference; t s Indicates the saturation temperature at the corresponding condenser pressure;

[0031] The overall heat transfer coefficient formula of HEI is expressed as:

[0032] K HEI =K0·β t β m

[0033] Among them, K HEI represents the overall heat transfer coefficient of HEI; K0 represents the basic heat transfer coefficient; β t Indicates the cooling water temperature correction coefficient; β m Indicates the correction factor of cooling pipe material and wall thickness;

[0034] The test cleaning coefficient formula is expressed as:

[0035] K=K HEI β c

[0036]

[0037] Among them, β C Indicates the tube bundle cleanliness factor;

[0038] The formula for circulating water flow MN* under each main steam pressure condition is:

[0039] T o N=Q / MN* / C P +T i N-1.

[0040] The net heat rate of the steam turbine unit is defined as: the net heat rate of the steam turbine unit = the heat absorption of the steam turbine unit after the first correction / (the output of the steam turbine unit after the first correction - the power increment of the circulating water pump motor);

[0041] According to the relationship curve between the flow rate and power of the circulating water pump, find out the circulating water flow rate M2*, M3*...MN* corresponding to the circulating water pump motor power W CP 2*, W CP 3*……WCPN*, then the circulating water pump power increment = (WCP2*, WCP3*……WCPN*)-W CP 1.

[0042] The second object of the present invention is to provide a steam turbine unit sliding pressure optimization device, comprising:

[0043] A first correction module is used to extract the thermal performance test data of the steam turbine unit, perform a first correction on the main steam temperature and the reheat steam temperature of the steam turbine unit at the same load point and different main steam pressure conditions, and determine the output, heat rate and heat absorption of the steam turbine unit after the first correction based on the main steam temperature and the reheat steam temperature obtained after the first correction;

[0044] A second correction module is used to designate a main steam pressure condition as a reference, perform a second correction on the steam turbine unit output under the main steam pressure condition outside the reference, and determine a steam turbine unit back pressure value under the main steam pressure condition outside the reference when the steam turbine unit output obtained by the second correction is equal to the steam turbine unit output obtained by the first correction;

[0045] a calculation module, for setting the circulating water temperature of the steam turbine unit under the main steam pressure condition outside the benchmark to be equal to the circulating water temperature of the steam turbine unit under the benchmark main steam pressure condition, determining the circulating water flow rate and circulating water outlet temperature under each main steam pressure condition outside the benchmark based on the back pressure value of the steam turbine unit under the main steam pressure condition outside the benchmark, and determining the circulating water pump motor power of the steam turbine unit under the main steam pressure condition outside the benchmark;

[0046] The optimization module is used to determine the net heat rate of the steam turbine unit based on the heat absorption of the steam turbine unit obtained after the first correction, and compare the net heat rates of the steam turbine unit corresponding to different main steam pressure conditions. The main steam pressure corresponding to the main steam pressure condition with the lowest net heat rate is the optimal sliding pressure main steam pressure of the steam turbine unit.

[0047] The third object of the present invention is to provide an electronic device, comprising: at least one processor; and a memory communicatively connected to the at least one processor; wherein the memory stores instructions executable by the at least one processor, and the instructions are executed by the at least one processor so that the at least one processor can execute each step of the method described in the aforementioned technical solution.

[0048] A fourth object of the present invention is to provide a non-transitory computer-readable storage medium storing computer instructions, wherein the computer instructions are used to enable the computer to execute each step in the method described in the aforementioned technical solution.

[0049] Different from the prior art, the steam turbine unit sliding pressure optimization method provided by the present invention collects the comprehensive thermal performance test data of the steam turbine unit to perform the first parameter correction calculation, obtains the first corrected steam turbine output and heat rate, and calculates the first corrected heat absorption, and then determines the back pressure value, circulating water flow rate and circulating water outlet temperature of the steam turbine unit, and compares the net heat rate of the steam turbine unit corresponding to different main steam pressure conditions based on the circulating water pump motor power of the steam turbine unit. The main steam pressure corresponding to the main steam pressure condition with the lowest net heat rate is the optimal steam turbine unit sliding pressure main steam pressure. Through the present invention, the impact of the main steam pressure of the steam turbine on the economic efficiency of the unit can be accurately evaluated, thereby providing reliable technical data for the operation of the unit, further reducing the net heat rate of the thermal power unit, and improving the efficiency of the power plant. BRIEF DESCRIPTION OF THE DRAWINGS

[0050] The present invention and / or additional aspects and advantages will become apparent and easily understood from the following description of the embodiments in conjunction with the accompanying drawings, in which:

[0051] Figure 1 It is a flow chart of a method for optimizing the sliding pressure of a steam turbine unit provided by the present invention.

[0052] Figure 2 It is a schematic diagram of a correction curve of main steam temperature to output and heat rate in a method for optimizing sliding pressure of a steam turbine unit provided by the present invention.

[0053] Figure 3 It is a schematic diagram of a correction curve of reheat steam temperature to output and heat rate in a steam turbine unit sliding pressure optimization method provided by the present invention.

[0054] Figure 4 It is a schematic diagram of a characteristic curve of steam turbine back pressure versus unit output in a steam turbine unit sliding pressure optimization method provided by the present invention.

[0055] Figure 5 It is a structural schematic diagram of a steam turbine unit sliding pressure optimization device provided by the present invention.

[0056] Figure 6 It is a structural schematic diagram of a non-temporary computer-readable storage medium provided by the present invention. DETAILED DESCRIPTION

[0057] Embodiments of the present invention are described in detail below, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the present invention, and should not be construed as limiting the present invention.

[0058] Figure 1A method for optimizing the sliding pressure of a steam turbine unit provided in an embodiment of the present invention comprises:

[0059] S101: extracting the thermal performance test data of the steam turbine unit, performing a first correction on the main steam temperature and the reheat steam temperature of the steam turbine unit at the same load point and different main steam pressure conditions, and determining the output, heat rate and heat absorption of the steam turbine unit after the first correction based on the main steam temperature and the reheat steam temperature obtained after the first correction.

[0060] Among them, the thermal performance test data of the steam turbine unit at least include the condensate flow rate, main steam and reheat steam parameters, extraction parameters, heater inlet parameters, condensate and feed water parameters, turbine back pressure and generator power of the steam turbine unit; the inlet and outlet temperatures of the condenser circulating water, the circulating water flow rate, and the hot well water temperature; the inlet and outlet pressures of the circulating water pump, the outlet flow rate of the circulating water pump, and the motor power of the circulating water pump; the exhaust flow rate and exhaust enthalpy of the steam turbine; the cleanliness coefficient and overall heat transfer coefficient of the condenser; and the thermal characteristic curve of the circulating water pump.

[0061] Specifically, according to the comprehensive thermal performance test method of the steam turbine, the performance test points are installed to extract the condensate flow, main steam and reheat steam parameters, extraction parameters, heater inlet steam parameters, condensate and feed water parameters, turbine back pressure and generator power;

[0062] According to the thermal performance test method of the condenser, the performance test points are installed to extract the inlet and outlet temperatures of the circulating water, the circulating water flow rate, and the hot well water temperature;

[0063] According to the thermal performance test method of the circulating water pump, the performance test points are installed to extract the pressure of the circulating water pump inlet and outlet, the circulating water pump outlet flow, and the circulating water pump motor power;

[0064] Refer to GB / T 8117.2-2014 steam turbine unit thermal performance test procedures to calculate the steam extraction flow rate of each extraction section, and obtain the exhaust flow rate and exhaust enthalpy of the steam turbine unit based on the mass and energy balance of the steam turbine;

[0065] Refer to HEI 2629:2006 Surface Steam Condenser Code to calculate the cleanliness factor and overall heat transfer coefficient of the condenser;

[0066] With reference to the hydraulic performance acceptance test level 1 and level 2 of GB / T 3216-2005 rotary dynamic pump, the thermal characteristic curve of the circulating water pump is calculated.

[0067] The step of performing a first correction on the main steam temperature and the reheat steam temperature of the steam turbine unit at the same load point and different main steam pressure conditions, and determining the first corrected output, heat rate and heat absorption of the steam turbine unit based on the main steam temperature and the reheat steam temperature obtained after the first correction, comprises:

[0068] The main steam temperature and reheat steam temperature are first corrected to the design value under the same load point and different main steam pressure conditions; the correction curve of main steam temperature to output and heat rate is as follows: Figure 2 shown.

[0069] The output and heat rate of the steam turbine unit after the first correction are calculated, and the heat absorption of the steam turbine unit after the first correction is calculated. The correction curve of the reheat steam temperature to the output and heat rate is as follows: Figure 3 shown.

[0070] The first corrected steam turbine unit output = steam turbine unit output test value / (1 + main steam temperature to power change rate) / (1 + reheat steam temperature to power change rate);

[0071] The first corrected steam turbine unit heat rate = steam turbine unit heat rate test value / (1 + main steam temperature to heat rate change rate) / (1 + reheat steam temperature to heat rate change rate);

[0072] The first corrected steam turbine unit heat absorption=the first corrected steam turbine unit output×the first corrected steam turbine unit heat rate.

[0073] S102: Designate the main steam pressure condition as a reference, perform a second correction on the steam turbine unit output under the main steam pressure condition outside the reference, and when the steam turbine unit output obtained by the second correction is equal to the steam turbine unit output obtained by the first correction, determine the steam turbine unit back pressure value under the main steam pressure condition outside the reference.

[0074] Under different working conditions at the same load point, the main steam pressure of the unit is MP1, MP2, MP3...MPN, and the corresponding back pressure is P1, P2, P3...PN. The steam turbine output after the first correction is W1, W2, W3...WN, and the corrected steam turbine heat rate is HR1, HR2, HR3...HRN. The MP1 working point is selected as the benchmark, and the other main steam pressure working conditions use the steam turbine unit's back pressure to correct the unit output characteristic curve or slightly increase the output to correct the steam turbine unit output. When the steam turbine unit output is equal to W1 after the second correction, the steam turbine back pressure value P2*, P3*...PN* is calculated. The schematic diagram of the steam turbine unit back pressure to unit output characteristic curve is as follows Figure 4 shown.

[0075] When determining the back pressure value of the steam turbine unit under the main steam pressure condition other than the reference, it includes:

[0076] Based on the steam turbine unit output obtained after the second correction, the adjacent power change rate is calculated;

[0077] Power change rate = (WN-1-WN) / WN

[0078] Among them, after the second correction, the steam turbine output corresponding to different main steam pressure conditions is W1, W2, W3...WN;

[0079] According to the turbine back pressure to unit output characteristic curve, obtain the power change rate corresponding to the back pressure PN*;

[0080] PN*=(PN+PN-1)-back pressure design value

[0081] Among them, under different operating conditions at the same load point, the main steam pressure of the unit is MP1, MP2, MP3...MPN, and the corresponding back pressure is P1, P2, P3...PN.

[0082] Step S103: Set the circulating water temperature of the steam turbine unit under the main steam pressure condition outside the benchmark to be equal to the circulating water temperature of the steam turbine unit under the benchmark main steam pressure condition, determine the circulating water flow rate and circulating water outlet temperature under each main steam pressure condition outside the benchmark based on the back pressure value of the steam turbine unit under the main steam pressure condition outside the benchmark, and determine the circulating water pump motor power of the steam turbine unit under the main steam pressure condition outside the benchmark.

[0083] At different main steam pressures, the corresponding circulating water inlet temperatures are T i 1. T i 2. T i 3……T i N, corresponding to the circulating water outlet temperature T o 1. T o 2. T o 3……T o N, the circulating water flow rates are M1, M2, M3...MN, and the power of the circulating water pump is W CP 1. W CP 2. W CP 3……W CP N, except MP1 operating point, set the circulating water temperature of other operating points to T i 1. According to the calculated cleanliness coefficient and overall heat transfer coefficient of the condenser, and the back pressure values ​​P2*, P3*...PN* of the steam turbine unit, the circulating water flow rate M2*, M3*...MN* and the circulating water outlet temperature T are calculated. o 2*, T o 3*……T o N*, taking the circulating water flow M2* as an example, the detailed calculation process is as follows:

[0084] 1) Calculation of condenser heat load:

[0085] Q=MN·C P ·(T o NT i N)

[0086] Where: Q——condenser heat load;

[0087] C P ——Specific heat of test circulating water at average water temperature.

[0088] 2) Overall heat transfer coefficient

[0089]

[0090] Where: K——overall heat transfer coefficient;

[0091] A——effective overall heat transfer area of ​​condenser;

[0092] △t m ——logarithmic mean temperature difference;

[0093] t s ——Saturation temperature corresponding to condenser pressure.

[0094] 3) HEI overall heat transfer coefficient

[0095] K HEI =K0·β t β m

[0096] Where: K HEI ——HEI overall heat transfer coefficient;

[0097] K0——basic heat transfer coefficient;

[0098] β t ——Cooling water temperature correction factor;

[0099] β m ——Cooling pipe material and wall thickness correction factor.

[0100] 4) Test cleaning factor

[0101] K=K HEI β c

[0102]

[0103] Where: β C ——Tube bundle cleanliness coefficient.

[0104] 5) Calculate M2*

[0105] Given the initial value of M2*

[0106] T o N=Q / MN* / C p +T i N-1

[0107] According to steps 1) to 4), the parameter x is calculated as:

[0108]

[0109]

[0110] Calculate the corresponding condenser pressure based on the saturation temperature. If the condenser pressure is different from P2*, reassign M2* and iterate the calculation again until they are the same.

[0111] According to the thermodynamic characteristic curve of the circulating water pump and the flow rate of the circulating water, calculate the power of the circulating water pump motor. According to the relationship curve between the circulating water pump flow rate and power, find out the circulating water pump motor power W corresponding to the circulating water flow rate M2*, M3*...MN*. CP 2*,W CP 3*……WCPN*.

[0112] S104: Determine the net heat rate of the steam turbine unit based on the heat absorption of the steam turbine unit obtained after the first correction, and compare the net heat rates of the steam turbine unit corresponding to different main steam pressure conditions. The main steam pressure corresponding to the main steam pressure condition with the lowest net heat rate is the optimal sliding pressure main steam pressure of the steam turbine unit.

[0113] The net heat rate of the steam turbine unit is defined as: the net heat rate of the steam turbine unit = the heat absorption of the steam turbine unit after the first correction / (the output of the steam turbine unit after the first correction - the power increment of the circulating water pump motor); the net heat rate of the unit is compared under each main steam pressure condition. When the net heat rate of the unit is the smallest, it is the optimal main steam pressure under the current load condition.

[0114] In addition, the present invention provides a steam turbine unit sliding pressure optimization device, comprising:

[0115] The first correction module 310 is used to extract the thermal performance test data of the steam turbine unit, perform a first correction on the main steam temperature and the reheat steam temperature of the steam turbine unit at the same load point and different main steam pressure conditions, and determine the output, heat rate and heat absorption of the steam turbine unit after the first correction based on the main steam temperature and the reheat steam temperature obtained after the first correction;

[0116] A second correction module 320 is used to specify a main steam pressure condition as a reference, perform a second correction on the steam turbine unit output under the main steam pressure condition outside the reference, and determine a steam turbine unit back pressure value under the main steam pressure condition outside the reference when the steam turbine unit output obtained by the second correction is equal to the steam turbine unit output obtained by the first correction;

[0117] The calculation module 330 is used to set the circulating water temperature of the steam turbine unit under the main steam pressure condition outside the benchmark to be equal to the circulating water temperature of the steam turbine unit under the benchmark main steam pressure condition, determine the circulating water flow rate and circulating water outlet temperature under each main steam pressure condition outside the benchmark based on the back pressure value of the steam turbine unit under the main steam pressure condition outside the benchmark, and determine the circulating water pump motor power of the steam turbine unit under the main steam pressure condition outside the benchmark;

[0118] The optimization module 340 is used to determine the net heat rate of the turbine unit based on the heat absorption of the turbine unit obtained after the first correction, and compare the net heat rates of the turbine unit corresponding to different main steam pressure conditions. The main steam pressure corresponding to the main steam pressure condition with the lowest net heat rate is the optimal sliding pressure main steam pressure of the turbine unit.

[0119] In order to implement the embodiment, the present invention also proposes an electronic device, comprising: at least one processor; and a memory communicatively connected to the at least one processor; wherein the memory stores instructions executable by the at least one processor, and the instructions are executed by the at least one processor so that the at least one processor can execute each step in the turbine unit sliding pressure optimization method described in the aforementioned technical solution.

[0120] like Figure 5 As shown, the non-transitory computer-readable storage medium includes a memory 810 of instructions, an interface 830, and the instructions can be executed by a processor 820 according to the steam turbine unit sliding pressure optimization to complete the method. Optionally, the storage medium can be a non-transitory computer-readable storage medium, for example, the non-transitory computer-readable storage medium can be a ROM, a random access memory (RAM), a CD-ROM, a magnetic tape, a floppy disk, an optical data storage device, etc.

[0121] In order to implement the embodiment, the present invention further proposes a non-temporary computer-readable storage medium on which a computer program is stored. When the computer program is executed by a processor, the sliding pressure optimization of the steam turbine unit as in the embodiment of the present invention is implemented.

[0122] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, without contradiction.

[0123] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In the description of the present invention, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0124] Any process or method description in a flowchart or otherwise described herein may be understood to represent a module, segment or portion of code comprising one or more executable instructions for implementing the steps of a custom logical function or process, and the scope of the preferred embodiments of the present invention includes alternative implementations in which functions may not be performed in the order shown or discussed, including performing functions in a substantially simultaneous manner or in reverse order depending on the functions involved, which should be understood by technicians in the technical field to which the embodiments of the present invention belong.

[0125] The logic and / or steps represented in the flowchart or otherwise described herein, for example, can be considered as an ordered list of executable instructions for implementing logical functions, and can be embodied in any computer-readable medium for use by an instruction execution system, device or apparatus (such as a computer-based system, a system including a processor, or other system that can fetch instructions from an instruction execution system, device or apparatus and execute the instructions), or in combination with these instruction execution systems, devices or apparatuses. For the purpose of this specification, "computer-readable medium" can be any device that can contain, store, communicate, propagate or transmit a program for use by an instruction execution system, device or apparatus, or in combination with these instruction execution systems, devices or apparatuses. More specific examples of computer-readable media (a non-exhaustive list) include the following: an electrical connection with one or more wires (electronic device), a portable computer disk box (magnetic device), a random access memory (RAM), a read-only memory (ROM), an erasable and programmable read-only memory (EPROM or flash memory), a fiber optic device, and a portable compact disk read-only memory (CDROM). In addition, the computer-readable medium may even be paper or other suitable medium on which the program is printed, since the program may be obtained electronically, for example, by optically scanning the paper or other medium and then editing, interpreting or processing in other suitable ways if necessary, and then stored in a computer memory.

[0126] It should be understood that the various parts of the present invention can be implemented by hardware, software, firmware or a combination thereof. In the described embodiment, a plurality of steps or methods can be implemented by software or firmware stored in a memory and executed by a suitable instruction execution system. For example, if implemented by hardware, as in another embodiment, it can be implemented by any one of the following technologies known in the art or their combination: a discrete logic circuit having a logic gate circuit for implementing a logic function for a data signal, a dedicated integrated circuit having a suitable combination of logic gate circuits, a programmable gate array (PGA), a field programmable gate array (FPGA), etc.

[0127] A person skilled in the art may understand that all or part of the steps of implementing the method of the embodiment may be completed by instructing related hardware through a program, and the program may be stored in a computer-readable storage medium, which, when executed, includes one or a combination of the steps of the method embodiment.

[0128] In addition, each functional unit in each embodiment of the present invention may be integrated into a processing module, or each unit may exist physically separately, or two or more units may be integrated into one module. The integrated module may be implemented in the form of hardware or in the form of a software functional module. If the integrated module is implemented in the form of a software functional module and sold or used as an independent product, it may also be stored in a computer-readable storage medium.

[0129] The storage medium mentioned above may be a read-only memory, a magnetic disk or an optical disk, etc. Although the embodiments of the present invention have been shown and described above, it can be understood that the embodiments are exemplary and cannot be construed as limiting the present invention. A person of ordinary skill in the art may change, modify, replace and modify the embodiments within the scope of the present invention.

Claims

1. A method for optimizing sliding pressure of a steam turbine unit, characterized in that: include: Extracting the thermal performance test data of the steam turbine unit, performing a first correction on the main steam temperature and the reheat steam temperature of the steam turbine unit at the same load point and different main steam pressure conditions, and determining the output, heat rate and heat absorption of the steam turbine unit after the first correction based on the main steam temperature and the reheat steam temperature obtained after the first correction; The main steam pressure condition is designated as a reference, a second correction is performed on the steam turbine unit output under the main steam pressure condition outside the reference, and when the steam turbine unit output obtained by the second correction is equal to the steam turbine unit output obtained by the first correction, a value of the steam turbine unit back pressure under the main steam pressure condition outside the reference is determined; The circulating water temperature of the steam turbine unit under the main steam pressure condition outside the benchmark is set to be equal to the circulating water temperature of the steam turbine unit under the benchmark main steam pressure condition, and based on the back pressure value of the steam turbine unit under the main steam pressure condition outside the benchmark, the circulating water flow rate and circulating water outlet temperature under each main steam pressure condition outside the benchmark are determined, and the circulating water pump motor power of the steam turbine unit under the main steam pressure condition outside the benchmark is determined; The net heat rate of the steam turbine unit is determined based on the heat absorption of the steam turbine unit obtained after the first correction, and the net heat rates of the steam turbine unit corresponding to different main steam pressure conditions are compared. The main steam pressure corresponding to the main steam pressure condition with the lowest net heat rate is the optimal sliding pressure main steam pressure of the steam turbine unit.

2. The method for optimizing the sliding pressure of a steam turbine unit according to claim 1, characterized in that: The thermal performance test data of the steam turbine unit at least include the condensate flow rate, main steam and reheat steam parameters, extraction parameters, heater inlet parameters, condensate and feed water parameters, turbine back pressure and generator power of the steam turbine unit; the inlet and outlet temperatures of the condenser circulating water, the circulating water flow rate, and the hot well water temperature; the inlet and outlet pressures of the circulating water pump, the outlet flow rate of the circulating water pump, and the motor power of the circulating water pump; the exhaust flow rate and exhaust enthalpy of the steam turbine; the cleanliness coefficient and overall heat transfer coefficient of the condenser; and the thermal characteristic curve of the circulating water pump.

3. The method for optimizing the sliding pressure of a steam turbine unit according to claim 1, characterized in that: The step of performing a first correction on the main steam temperature and the reheat steam temperature of the steam turbine unit at the same load point and different main steam pressure conditions, and determining the first corrected output, heat rate and heat absorption of the steam turbine unit based on the main steam temperature and the reheat steam temperature obtained after the first correction, comprises: Performing a first correction on the main steam temperature and the reheat steam temperature at the same load point and different main steam pressure conditions to correct them to the design values; The output and heat rate of the steam turbine unit after the first correction are calculated, and the heat absorption amount of the steam turbine unit after the first correction is calculated.

4. The method for optimizing the sliding pressure of a steam turbine unit according to claim 3, characterized in that: The first corrected steam turbine unit output = steam turbine unit output test value / (1 + main steam temperature to power change rate) / (1 + reheat steam temperature to power change rate); The first corrected steam turbine unit heat rate = steam turbine unit heat rate test value / (1 + main steam temperature to heat rate change rate) / (1 + reheat steam temperature to heat rate change rate); The first corrected steam turbine unit heat absorption=the first corrected steam turbine unit output×the first corrected steam turbine unit heat rate.

5. The method for optimizing the sliding pressure of a steam turbine unit according to claim 1, characterized in that: When determining the back pressure value of the steam turbine unit under the main steam pressure condition other than the reference, it includes: Based on the steam turbine unit output obtained after the second correction, the adjacent power change rate is calculated; Power change rate = (WN-1-WN) / WN Among them, after the second correction, the steam turbine output corresponding to different main steam pressure conditions is W1, W2, W3...WN; According to the turbine back pressure to unit output characteristic curve, obtain the power change rate corresponding to the back pressure PN*; PN*=(PN+PN-1)-back pressure design value Among them, under different operating conditions at the same load point, the main steam pressure of the unit is MP1, MP2, MP3...MPN, and the corresponding back pressure is P1, P2, P3...PN.

6. The method for optimizing the sliding pressure of a steam turbine unit according to claim 2, characterized in that: The step of determining the circulating water flow rate and circulating water outlet temperature under each main steam pressure condition other than the corresponding reference comprises: Under different main steam pressure conditions, the corresponding circulating water inlet temperature is T i 1. T i 2. T i 3……T i N; corresponding circulating water outlet temperature is T o 1. T o 2. T o 3……T o N; the circulating water flow rates are M1, M2, M3...MN respectively, and the power of the circulating water pump is W CP 1. W CP 2. W CP 3……W CP N; Except MP1 operating point, set the circulating water temperature of other operating points to T i 1; Calculate the condenser heat load based on the condenser cleanliness factor and overall heat transfer coefficient; Q=MN·C P ·(T o N-T i N) Where, Q represents the condenser heat load, C P It indicates the specific heat of the test circulating water at the average water temperature; The overall heat transfer coefficient formula is expressed as: Where K represents the overall heat transfer coefficient; A represents the effective overall heat transfer area of ​​the condenser; Δt m represents the logarithmic mean temperature difference; t s Indicates the saturation temperature at the corresponding condenser pressure; The overall heat transfer coefficient formula of HEI is expressed as: K HEI =K0·β t ·b m Among them, K HEI represents the overall heat transfer coefficient of HEI; K0 represents the basic heat transfer coefficient; β t Indicates the cooling water temperature correction coefficient; β m Indicates the correction factor of cooling pipe material and wall thickness; The test cleaning coefficient formula is expressed as: K=K HEI ·b c Among them, β C Indicates the tube bundle cleanliness factor; The formula for circulating water flow MN* under each main steam pressure condition is: T o N=Q / MN* / C P +T i N-1。 7. The method for optimizing the sliding pressure of a steam turbine unit according to claim 1, characterized in that: The net heat rate of the steam turbine unit is defined as: the net heat rate of the steam turbine unit = the heat absorption of the steam turbine unit after the first correction / (the output of the steam turbine unit after the first correction - the power increment of the circulating water pump motor); According to the relationship curve between the flow rate and power of the circulating water pump, find out the circulating water flow rate M2*, M3*...MN* corresponding to the circulating water pump motor power W CP 2*, W CP 3*......WCPN*, then the circulating water pump power increment = (WCP2*, WCP3*......WCPN*)-W CP 1.

8. A steam turbine unit sliding pressure optimization device, characterized in that: include: A first correction module is used to extract the thermal performance test data of the steam turbine unit, perform a first correction on the main steam temperature and the reheat steam temperature of the steam turbine unit at the same load point and different main steam pressure conditions, and determine the output, heat rate and heat absorption of the steam turbine unit after the first correction based on the main steam temperature and the reheat steam temperature obtained after the first correction; A second correction module is used to designate a main steam pressure condition as a reference, perform a second correction on the steam turbine unit output under the main steam pressure condition outside the reference, and determine a steam turbine unit back pressure value under the main steam pressure condition outside the reference when the steam turbine unit output obtained by the second correction is equal to the steam turbine unit output obtained by the first correction; a calculation module, for setting the circulating water temperature of the steam turbine unit under the main steam pressure condition outside the benchmark to be equal to the circulating water temperature of the steam turbine unit under the benchmark main steam pressure condition, determining the circulating water flow rate and circulating water outlet temperature under each main steam pressure condition outside the benchmark based on the back pressure value of the steam turbine unit under the main steam pressure condition outside the benchmark, and determining the circulating water pump motor power of the steam turbine unit under the main steam pressure condition outside the benchmark; The optimization module is used to determine the net heat rate of the steam turbine unit based on the heat absorption of the steam turbine unit obtained after the first correction, and compare the net heat rates of the steam turbine unit corresponding to different main steam pressure conditions. The main steam pressure corresponding to the main steam pressure condition with the lowest net heat rate is the optimal sliding pressure main steam pressure of the steam turbine unit.

9. An electronic device, comprising: at least one processor; and a memory communicatively connected to the at least one processor; wherein the memory stores instructions executable by the at least one processor, and the instructions are executed by the at least one processor so that the at least one processor can perform each step in the method described in any one of claims 1-7.

10. A non-transitory computer-readable storage medium storing computer instructions, wherein: The computer instructions are used to cause the computer to execute each step of the method according to any one of claims 1 to 7.

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