CN114856726B - Real-time determination method for exhaust steam volume flow and humidity of saturated steam turbine - Google Patents

Real-time determination method for exhaust steam volume flow and humidity of saturated steam turbine Download PDF

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CN114856726B
CN114856726B CN202210554966.4A CN202210554966A CN114856726B CN 114856726 B CN114856726 B CN 114856726B CN 202210554966 A CN202210554966 A CN 202210554966A CN 114856726 B CN114856726 B CN 114856726B
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steam
saturated
humidity
specific enthalpy
mass flow
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CN114856726A (en
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孙鑫宇
袁景淇
凌君
付周
邹恒斐
惠久武
胡诗曲
董贺
邓冠华
栾振华
宋飞
刘鹏
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Shanghai Jiaotong University
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    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
    • F01D—NON-POSITIVE DISPLACEMENT MACHINES OR ENGINES, e.g. STEAM TURBINES
    • F01D21/00—Shutting-down of machines or engines, e.g. in emergency; Regulating, controlling, or safety means not otherwise provided for
    • F01D21/003—Arrangements for testing or measuring
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
    • F01D—NON-POSITIVE DISPLACEMENT MACHINES OR ENGINES, e.g. STEAM TURBINES
    • F01D21/00—Shutting-down of machines or engines, e.g. in emergency; Regulating, controlling, or safety means not otherwise provided for
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
    • F01D—NON-POSITIVE DISPLACEMENT MACHINES OR ENGINES, e.g. STEAM TURBINES
    • F01D21/00—Shutting-down of machines or engines, e.g. in emergency; Regulating, controlling, or safety means not otherwise provided for
    • F01D21/14—Shutting-down of machines or engines, e.g. in emergency; Regulating, controlling, or safety means not otherwise provided for responsive to other specific conditions
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
    • F01D—NON-POSITIVE DISPLACEMENT MACHINES OR ENGINES, e.g. STEAM TURBINES
    • F01D25/00—Component parts, details, or accessories, not provided for in, or of interest apart from, other groups
    • F01D25/30—Exhaust heads, chambers, or the like
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
    • Y02E30/00—Energy generation of nuclear origin

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Abstract

The invention provides a method for determining the dead steam volume flow and humidity of a saturated steam turbine in real time, which comprises the following steps: s1, acquiring equipment structural parameters of a low-pressure cylinder and a low-pressure feed water heater of a steam turbine, and operating data of the low-pressure cylinder and the low-pressure feed water heater of the steam turbine at a given moment; s2, calculating the dry basis internal efficiency and the steam-water separation efficiency of each level of groups; s3, calculating the specific enthalpy of the saturated steam after expansion in the stage group; s4, calculating the mass flow and specific enthalpy of saturated steam after steam-water separation; s5, calculating the mass flow of saturated steam after steam extraction; s6, taking the specific enthalpy and the mass flow of the steam at the outlet of the previous stage group as the specific enthalpy and the mass flow of the steam at the inlet of the next stage group, and sequentially calculating the specific enthalpy and the mass flow of the saturated steam at the outlet of each stage group to obtain the exhaust steam humidity; s7, calculating the dead steam volume flow of the saturated steam turbine. The method can be used for calculating the volume flow and the humidity of the exhaust steam of the saturated steam turbine on line, and solves the problem that the variable cannot be measured in real time.

Description

Real-time determination method for exhaust steam volume flow and humidity of saturated steam turbine
Technical Field
The invention relates to the technical field of nuclear power station operation optimization control, in particular to a method for determining exhaust steam volume flow and humidity of a saturated steam turbine in real time.
Background
The saturated steam turbine is a turbine taking saturated steam as working medium, and the saturated steam is a mixture of dry saturated steam and saturated water. In a nuclear power unit, all stages of the high pressure cylinder and the last stages of the low pressure cylinder operate in a saturated steam region except for the first few stages of the low pressure cylinder.
The exhaust steam volume flow and the humidity of the saturated steam turbine can be used for monitoring the running state of the turbine, and the purpose is to improve the running safety and economy of the nuclear power unit. If the volume flow of the dead steam is too large, the vibration of the last stage blade of the low-pressure cylinder can be caused, and the operation safety of the unit is affected; and the residual speed loss of the steam turbine is increased, so that the economy of the unit is reduced. When the humidity of the exhaust steam is too high, erosion of the blade can be caused, and the service life of the equipment is shortened; and at the same time, the moisture loss of the steam turbine is aggravated, so that the internal efficiency of the steam turbine is reduced.
Because of the huge volume flow of the exhaust steam of the saturated steam turbine (the volume flow of the exhaust steam of the 1000MW unit is about 3000 m) 3 S) and is in a gas-liquid two-phase flow state, so that the mass flow or the volume flow of the dead steam is difficult to directly measure through a flowmeter. Meanwhile, the online measurement of the exhaust steam humidity has great difficulty: isotope tracking methods are affected by half-life and cannot be used for a long time; the optical method is greatly influenced by the particle size of the liquid drops, and has lower precision; thermodynamic methods cannot achieve on-line continuous measurements. As for the soft measurement method, as all levels of extraction steam of the saturated steam turbine are wet saturated steam, and all the mass flow and humidity (or specific enthalpy) of all levels of extraction steam are unknown variables, the existing soft measurement method for the superheated steam turbine of the thermal power unit is not suitable for the saturated steam turbine.
After searching the prior art, the invention is found that China patent with the application number of CN202110229455.0 and the application date of 2021, 03 and 02 is related to the invention, namely a final stage blade volume flow estimation method, a flutter early warning system and a flutter early warning device. But the method involves numerous linearization assumptions, such as main steam pressure, extraction steam pressure, steam expansion ratio, etc., which are not verified and are truly nonlinear, the accuracy of the calculations made from this assumption is questionable. More importantly, the method provided by the patent is only applicable to superheated steam, and the extraction steam of each stage of the saturated steam turbine is saturated steam.
In fact, the prior published and reported documents and patents do not relate to a real-time determination method for the dead steam volume flow and humidity of a saturated steam turbine, and the blank is to be filled.
Disclosure of Invention
Aiming at the defects of the prior art, the invention provides a method for determining the dead steam volume flow and the humidity of a saturated steam turbine in real time.
The invention provides a method for determining the dead steam volume flow and the humidity of a saturated steam turbine in real time, which comprises the following steps:
s1: acquiring equipment structural parameters of a low-pressure cylinder and a low-pressure feed water heater of a steam turbine, design parameters of the steam turbine and operation data of the low-pressure cylinder and the low-pressure feed water heater of the steam turbine at given time;
s2: calculating the dry basis internal efficiency and the steam-water separation efficiency of each stage of groups according to the turbine design parameters of the S1;
s3: calculating the specific enthalpy of the saturated steam after expansion in the stage group according to the specific enthalpy and the pressure of the low-pressure cylinder inlet working medium obtained in the step S1 and the pressure of the steam extraction port working medium and the dry basis internal efficiency of the step S2;
s4: according to the steam-water separation efficiency of the stage group obtained in the step S2 and the specific enthalpy of the saturated steam obtained in the step S3 after expansion in the stage group, calculating the mass flow, specific enthalpy and humidity of the saturated steam after steam-water separation, and taking the specific enthalpy of the saturated steam after steam-water separation as the specific enthalpy of the saturated steam at the outlet of the stage group;
s5: according to the inlet and outlet water supply mass flow and specific enthalpy of the low-pressure feed water heater in the S1 operation data and the calculated specific enthalpy of the saturated steam at the outlet of the stage group, calculating the mass flow of the saturated steam after steam extraction, and taking the mass flow of the saturated steam after steam extraction as the mass flow of the saturated steam at the outlet of the stage group;
s6: taking the specific enthalpy and the mass flow of the steam at the outlet of the previous stage group as the specific enthalpy and the mass flow of the steam at the inlet of the next stage group, repeating S3-S5, and sequentially calculating the specific enthalpy and the mass flow of the saturated steam at the outlet of each stage group until all the stage groups are calculated; and obtaining the specific enthalpy, humidity and mass flow of exhaust steam of the saturated steam turbine.
S7: and (3) calculating the dead steam volume flow of the saturated steam turbine according to the dead steam specific enthalpy and the mass flow in the step S6.
In a second aspect of the present invention, a readable medium is provided, where instructions are stored on the readable medium, where the instructions, when executed on an electronic device, cause the electronic device to perform the method for determining the dead steam volume flow and the humidity of the saturated steam turbine in real time.
In a third aspect of the present invention, an electronic device is provided, including a memory, a processor, and a computer program stored in the memory and capable of running on the processor, where the processor is configured to execute the method for determining the exhaust steam volume flow and the humidity of the saturated steam turbine in real time when the processor executes the program.
Compared with the prior art, the embodiment of the invention has at least one of the following beneficial effects:
the real-time determination method for the exhaust steam volume flow and the humidity of the saturated steam turbine can be used for determining the volume flow and the humidity of the exhaust steam of the saturated steam turbine on line, and solves the problem that the volume flow and the humidity of the exhaust steam cannot be measured in real time; the obtained volume flow and humidity can be used for monitoring the running state of the low-pressure cylinder of the steam turbine, and has application potential for improving the safety and economy of the saturated steam turbine of the nuclear power plant.
The method for determining the dead steam volume flow and the humidity of the saturated steam turbine in real time is suitable for the saturated steam turbine of a nuclear power station and the saturated steam turbine in other application fields. The fundamental difference between the method and the related technology applied to the thermal power turbine at present is that the extraction steam of the thermal power turbine is in an overheated state, and the specific enthalpy can be calculated according to the temperature and the pressure; and the specific enthalpy (humidity) and the mass flow of the extracted steam of the saturated steam turbine are unknown variables.
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Other features, objects and advantages of the present invention will become more apparent upon reading of the detailed description of non-limiting embodiments, made with reference to the following drawings.
FIG. 1 is a schematic diagram of a low pressure cylinder, low pressure feedwater heating system and condenser according to an embodiment of the present invention;
FIG. 2 is a flow chart of a method for determining the dead steam volume flow and the humidity of a saturated steam turbine in real time according to an embodiment of the invention;
FIG. 3 is a graph showing a change in output power of a nuclear power unit according to an embodiment of the present invention;
FIG. 4 is a graph showing the calculation of dead steam volumetric flow rate of a saturated steam turbine according to an embodiment of the present invention;
FIG. 5 is a graph showing the calculation of the exhaust steam humidity of a saturated steam turbine according to an embodiment of the present invention;
FIG. 6 is a graph showing the heat released by exhaust steam versus the heat absorbed by circulating water in an embodiment of the invention.
Detailed Description
The present invention will be described in detail with reference to specific examples. The following examples will assist those skilled in the art in further understanding the present invention, but are not intended to limit the invention in any way. It should be noted that variations and modifications could be made by those skilled in the art without departing from the inventive concept. These are all within the scope of the present invention.
The method comprises the steps of dividing a steam turbine into a plurality of serially connected stage groups, and calculating to obtain the mass flow, specific enthalpy and humidity of saturated steam at the outlet of the stage groups according to the mass flow, specific enthalpy and humidity of saturated steam at the inlet of the stage groups; and sequentially calculating each stage group from the inlet of the saturated steam turbine to obtain the mass flow and specific enthalpy of the exhaust steam of the steam turbine, and finally obtaining the exhaust steam volume flow and humidity of the saturated steam turbine.
FIG. 1 is a schematic diagram of a low pressure cylinder, low pressure feedwater heating system, and condenser in accordance with an embodiment of the present invention, the embodiment being applied to a 1000MW pressurized water reactor nuclear power unit; the reheat steam enters the low pressure cylinder to do work and becomes 4-stage steam extraction and exhaust steam, a plurality of stages in the middle of each two stages of steam extraction of the steam turbine are regarded as a stage group, the steam at the outlet of the previous stage group is taken as the inlet steam of the next stage group except the steam entering the steam extraction pipeline.
Referring to FIG. 2, a flow chart of a method for determining the dead steam volume flow and the humidity of a saturated steam turbine in real time according to an embodiment of the invention is shown. Specifically, the method for determining the exhaust steam volume flow and the humidity of the saturated steam turbine in real time in the embodiment comprises the following steps:
s1: acquiring equipment structural parameters of a low-pressure cylinder and a low-pressure feed water heater of a steam turbine, design parameters of the steam turbine and operation data of the low-pressure cylinder and the low-pressure feed water heater of the steam turbine at given time;
s2: calculating the dry basis internal efficiency and the steam-water separation efficiency of each stage of groups according to the turbine design parameters of the S1;
s3: calculating the specific enthalpy of the saturated steam after expansion in the stage group according to the specific enthalpy and the pressure of the low-pressure cylinder inlet working medium in the S1 and the pressure of the working medium in the steam extraction port and the dry basis internal efficiency in the S2;
s4: according to the steam-water separation efficiency of the stage group obtained in the step S2 and the specific enthalpy of the saturated steam obtained in the step S3 after expansion in the stage group, calculating the mass flow, specific enthalpy and humidity of the saturated steam after steam-water separation, and taking the specific enthalpy of the saturated steam after steam-water separation as the specific enthalpy of the saturated steam at the outlet of the stage group;
s5: according to the water supply mass flow and specific enthalpy of the inlet and outlet of the low-pressure feed water heater in the S1 operation data and the specific enthalpy of the saturated steam of the outlet of the stage group obtained in the S4, calculating the mass flow of the saturated steam after steam extraction, and taking the mass flow of the saturated steam of the steam extraction as the mass flow of the saturated steam of the outlet of the stage group;
s6: taking the specific enthalpy and the mass flow of the steam at the outlet of the previous stage group as the specific enthalpy and the mass flow of the steam at the inlet of the next stage group, repeating S3-S5, and sequentially calculating the specific enthalpy and the mass flow of the saturated steam at the outlet of each stage group until all the stage groups are calculated; specific enthalpy h of the outlet saturated steam of the last stage group out Humidity y out And mass flow rate D out Specific enthalpy h respectively used as exhaust steam of saturated steam turbine exh Humidity y exh And mass flow rate D exh ；
S7: and (3) calculating the dead steam volume flow of the saturated steam turbine according to the dead steam specific enthalpy and the mass flow in the step S6.
In a preferred embodiment, in S1, the operation data may be obtained by a DCS in the field, including: the inlet working medium mass flow, specific enthalpy and humidity of the steam turbine, the extraction pressure of the inlet and outlet of each stage, the inlet and outlet water supply mass flow and specific enthalpy of the low-pressure water supply heater.
The device structure parameters include: the number of stages and the position of the steam extraction opening of the steam turbine, the overall dimension of each feedwater heater, the length and the pipe diameter of the heat exchange pipe can be obtained according to the regulations of the steam turbine and the feedwater heaters;
the design parameters of the steam turbine include: the design values of the temperature, pressure, specific enthalpy and humidity of the working medium of each stage of the steam turbine are obtained according to the rule of the steam turbine.
The above-mentioned equipment structural parameters and design parameters of the steam turbine are referred to according to the product manual or provided by manufacturer.
In S2, the dry basis internal efficiency and the steam-water separation efficiency of each stage group are calculated according to the turbine design parameters:
Figure GDA0004202693470000051
wherein:
Figure GDA0004202693470000052
Figure GDA0004202693470000053
wherein eta is dry Is the dry basis internal efficiency of the class group, and has no dimension; η (eta) ref Is a class group in the design working conditionThe internal efficiency of the turbine, namely the maximum internal efficiency of the turbine, is dimensionless; alpha is the Bowman factor of the class group, dimensionless; y is in ref And y out ref The humidity of the inlet steam and the outlet steam of the stage group under the design working condition is dimensionless; h is a in ref And h out ref The specific enthalpy of inlet and outlet steam of the stage group under the design working condition is kJ/kg respectively; p is p in ref And p out ref The pressure of steam at the inlet and outlet of the stage group under the design working condition is MPa; ρ in ref And ρ out ref The density of the steam at the inlet and the outlet of the stage group under the design working condition is kg/m 3 The method comprises the steps of carrying out a first treatment on the surface of the Kappa is the logarithmic average adiabatic index of the order group, dimensionless.
In the preferred embodiment, the dry basis internal efficiency is calculated by adopting the formula, and compared with the prior method, the method has the advantages of convenient implementation and accurate calculation result.
As a preferred embodiment, the steam-water separation efficiency of the stage group is calculated by the following formula:
Figure GDA0004202693470000054
wherein eta is sp The steam-water separation efficiency of the stage group is dimensionless; d (D) dw ref The mass flow rate of the steam turbine interstage drainage under the design working condition is kg/s; d (D) in ref Is the mass flow of the inlet working medium of the lower-level group under the design working condition, kg/s.
In the preferred embodiment, the steam-water separation efficiency formula is adopted, and the steam-water separation process of the steam-water separation device in the stage group solves the problem that the process has no measuring point.
As a preferred embodiment, in S3, the calculating of the specific enthalpy of the saturated steam after expansion in the stage group includes the following steps:
(a) Calculating the humidity y of the inlet working medium of the grade group in Sum of specific entropy s in ：
Figure GDA0004202693470000055
s in ＝(1-y in )s V (p in )+y in s L (p in )
Wherein y is in The humidity of the working medium at the inlet of the class group is dimensionless; h is a in Is the specific enthalpy of the inlet working medium of the class group, kJ/kg; p is p in Is the pressure of the working medium at the inlet of the class group and MPa; s is(s) in Is the specific entropy of the inlet working medium of the class group, kJ/(kg. Times.K); h is a L (p in ) And h V (p in ) The specific enthalpy of saturated water and saturated dry steam corresponding to the pressure of the working medium at the inlet of the grade group are kJ/kg respectively; s is(s) L (p in ) Sum s V (p in ) The specific entropy of saturated water and saturated dry steam corresponding to the pressure of the working medium at the inlet of the stage group is kJ/(kg.times.K).
(b) According to the calculated specific entropy s of the class group inlet working medium in the step (a) in Calculating the humidity y of the steam at the outlet of the stage group during isentropic expansion out,s And specific enthalpy h out,s ：
Figure GDA0004202693470000061
h exp,s ＝(1-y exp,s )h V (p out )+y exp,s h L (p out )
Wherein y is exp,s The humidity of the working medium at the outlet of the class group during isentropic expansion is dimensionless; h is a exp,s The specific enthalpy of the working medium at the outlet of the class group during isentropic expansion is kJ/kg; p is p out Is the pressure of working medium at the outlet of the class group and MPa; s is(s) L (p out ) Sum s V (p out ) The specific entropy of saturated water and saturated dry steam corresponding to the pressure of the working medium at the outlet of the stage group is kJ/(kg x K); h is a L (p out ) And h V (p out ) The specific enthalpy of saturated water and saturated dry steam corresponding to the pressure of the working medium at the outlet of the stage group are kJ/kg respectively.
(c) Internal efficiency of the compute class group:
η exp ＝η dry (1-αy in )
wherein eta is exp The efficiency in the class group under the variable working condition is dimensionless; η (eta) dry Is the dry basis internal efficiency of the class group, and has no dimension; y is in Is the steam humidity of the inlet of the stage group and has no dimension.
(d) The specific enthalpy h of the isentropic expansion stage group outlet steam obtained according to (b) exp,s And (c) intra-stage group efficiency η exp And calculating the specific enthalpy and humidity of the steam after expansion in the stage group:
h exp ＝h in -η exp (h in -h exp,s )
Figure GDA0004202693470000062
in the formula, h exp Is the specific enthalpy of the steam after expansion in the stage group, kJ/kg; y is exp The humidity of the steam after expansion in the stage group is dimensionless; h is a L (p out ) And h V (p out ) The specific enthalpy of saturated water and saturated dry steam corresponding to the pressure of the working medium at the outlet of the stage group are kJ/kg respectively.
(e) According to the stage group outlet humidity y obtained in (d) exp Correction of intra-stage group efficiency eta exp ：
Figure GDA0004202693470000063
(f) Repeating the step (d) to obtain the specific enthalpy h of the steam after expansion in the stage group exp Humidity y exp 。
The above step (c) wherein eta exp And (d) h in exp Will affect each other and therefore require recalculation of η using the result of (d) exp I.e. (e) step, re-calculating the obtained eta exp To recalculate h exp . The result obtained in this way is more accurate and corresponds to the actual situation of the steam turbine.
In the preferred embodiment, in the process of calculating the specific enthalpy of the saturated steam after expansion in the stage group by adopting the steps (a) - (f), the influence of the steam humidity on the efficiency in the stage group is considered, and compared with the prior art, the accuracy of the result is higher.
As a preferred embodiment, in S4, the specific enthalpy of saturated steam after steam-water separation is calculated by the following formula:
Figure GDA0004202693470000071
in the formula, h sep The specific enthalpy of saturated steam after steam-water separation is kJ/kg; d (D) in Is the mass flow of the working medium at the inlet of the class group, kg/s; h is a exp Is the specific enthalpy of the steam after expansion in the stage group, kJ/kg; η (eta) sp The steam-water separation efficiency of the stage group is dimensionless; y is exp The humidity of the steam after expansion in the stage group is dimensionless; p is p out Is the pressure of working medium at the outlet of the class group and MPa; h is a L (p out ) Is the specific enthalpy of saturated water corresponding to the pressure of the working medium at the outlet of the grade group, kJ/kg.
In the preferred embodiment, the saturated steam specific enthalpy calculation formula after steam-water separation is adopted, the influence of the internal dehumidifying device of the turbine stage unit on the steam specific enthalpy is considered, and the gap in the prior art is made up.
As a preferred embodiment, the saturated steam humidity after steam-water separation is calculated by the following formula:
Figure GDA0004202693470000072
wherein y is sep The saturated steam humidity after steam-water separation is dimensionless; h is a V (p out ) The specific enthalpy of saturated dry steam corresponding to the pressure of the working medium at the outlet of the stage group is kJ/kg.
In the preferred embodiment, the saturated steam humidity calculation formula after steam-water separation is adopted, the influence of the internal dehumidifying device of the turbine stage unit on the saturated steam humidity is considered, and the gap in the prior art is made up.
As a preferred embodiment, the mass flow of saturated steam after steam-water separation is calculated by the following formula:
D sep ＝(1-η sp y exp )D in
wherein D is sep The mass flow of saturated steam after steam-water separation is kg/s; d (D) in Is the mass flow rate of saturated steam at the inlet of the stage group and kg/s.
In the preferred embodiment, the saturated steam mass flow calculation formula after steam-water separation is adopted, so that the problem that the mass flow of the steam turbine cannot be measured is solved.
As a preferred embodiment, the saturated steam specific enthalpy h after steam-water separation sep Specific enthalpy h of saturated steam as stage group outlet out The method comprises the steps of carrying out a first treatment on the surface of the The saturated steam humidity y after steam-water separation sep Humidity y of saturated steam as stage group outlet out 。
In a preferred embodiment, in S5, the mass flow of saturated steam after steam extraction is calculated by the following formula:
D ext ＝D sep -D es
wherein D is ext Is the mass flow of saturated steam after steam extraction, kg/s; d (D) sep The mass flow of saturated steam after steam-water separation is kg/s; d (D) es Is the extraction mass flow rate, kg/s.
In the preferred embodiment, the mass flow calculation formula of the saturated steam after steam extraction is adopted, so that the problem that the mass flow of the saturated steam after steam extraction of the steam turbine cannot be measured is solved.
As a preferred embodiment, the extraction mass flow rate D es Obtained by solving the following equation set:
Figure GDA0004202693470000081
Figure GDA0004202693470000082
Figure GDA0004202693470000083
Figure GDA0004202693470000084
Figure GDA0004202693470000085
wherein V is V Is the steam volume in the feed water heater, m 3 ；ρ V Is saturated dry steam density, kg/m 3 ；h L And h V Saturated water and saturated dry steam specific enthalpy, kJ/kg respectively; d (D) es Is the extraction mass flow, kg/s; d (D) dw,in Is the hydrophobic mass flow rate of the upper-level feed water heater, kg/s; h is a dw,in Is the hydrophobic specific enthalpy of the upper-level feed water heater, kJ/kg; d (D) con Is the mass flow of the condensed water, kg/s; q (Q) V Is the heat flow of the steam condensing section and the hydrophobic cooling section, kW; s is S V Is the heat exchange area, m of the steam condensation section of the feedwater heater 2 ；T es And T fw The steam extraction temperature and the water supply temperature are respectively, K; k (K) fw And K es Surface heat transfer coefficients, kW/(m), of feedwater and steam respectively 2 *K)；w fw Is the flow rate of the feed water, m/s; ρ fw Is the density of the water supply, kg/m 3 ，λ fw And lambda (lambda) L,es The heat conductivity of saturated water corresponding to the heat conductivity of water supply and the steam extraction pressure are kW/(m.times.K); c p,fw Is the constant pressure specific heat capacity of the feed water, kW/(kg. Times.K); mu (mu) fw Sum mu L,es The dynamic viscosity of the water supply and the saturated hydrodynamic viscosity corresponding to the extraction pressure are Pa.s respectively; d, d i Is the inner diameter of a heat exchange tube, m; g is the gravity acceleration, 9.8m/s 2 ；ρ L,es Is the saturated water density corresponding to the extraction pressure, kg/m 3 ；d o Is the outer diameter m of a heat exchange tube of the feed water heater.
Saturated steam mass flow D after steam extraction ext Mass flow D of saturated steam as stage bank outlet out 。
As a preferred embodiment, in S7, the dead steam volume flow of the saturated steam turbine is calculated by adopting the following formula:
Figure GDA0004202693470000091
wherein V is exh Is the dead steam volume flow of the saturated steam turbine, m 3 /s；D exh S6, obtaining the dead steam mass flow of the saturated steam turbine, and kg/S; y is exh S6, obtaining the exhaust steam humidity of the saturated steam turbine, wherein the exhaust steam humidity is dimensionless; p is p exh Is the dead steam pressure of a saturated steam turbine and MPa; ρ L (p exh ) And ρ V (p exh ) The pressure of exhaust steam of the steam turbine corresponds to the saturated water density and the saturated dry steam density, kg/m 3 。
As a preferred embodiment, the exhaust steam humidity of the saturated steam turbine is y in S6 exh 。
In the embodiment of the method for determining the exhaust steam volume flow and the humidity in real time based on the saturated steam turbine, DCS actual measurement data of a nuclear power unit are firstly acquired. Wherein, the unit output power is shown in figure 3.
FIG. 4 is a calculation result of dead steam volume flow of a saturated steam turbine according to an embodiment of the present invention, where the dead steam volume flow is determined based on existing measurement point data of the saturated steam turbine, so as to solve the problem that the dead steam volume flow has no measurement point.
FIG. 5 is a calculation result of the exhaust steam humidity of the saturated steam turbine according to an embodiment of the present invention, which can solve the problem that the exhaust steam humidity of the saturated steam turbine cannot be measured on line.
FIG. 6 is a graph showing the exhaust steam heat release versus the heat absorption of the circulating water calculated from the circulating water pump current and the circulating water inlet and outlet temperatures according to an embodiment of the present invention. The average relative error of the two is 1.70%, and the consistency of the two can indirectly verify the correctness of the online determination of the exhaust steam humidity and the volume flow.
Based on the same technical concept, in another embodiment of the present invention, a readable medium is further provided, and instructions are stored on the readable medium, where the instructions when executed on an electronic device cause the electronic device to execute the method for determining the exhaust steam volume flow and the humidity of the steam turbine in real time according to any one of the above embodiments.
Based on the same technical concept, in another embodiment of the present invention, an electronic device is further provided, which includes a memory, a processor, and a computer program stored on the memory and capable of running on the processor, where the processor is configured to execute the method for determining the exhaust steam volume flow and the humidity of the saturated steam turbine according to any one of the foregoing embodiments in real time when executing the program.
In order to better illustrate the implementation process of the present invention, taking the 3 rd stage group (the stage group includes all stages between the 2 nd stage steam extraction port and the 1 st stage steam extraction port) of the most representative low pressure cylinder front runner in the steam turbine shown in fig. 1 as an example, a real-time determination method for the exhaust steam volume flow and humidity of the saturated steam turbine at a certain moment is shown:
s1, acquiring operation data through a DCS on site, wherein the method comprises the following steps: the mass flow rate of the working medium at the inlet of the steam turbine is 1180kg/s, and the specific enthalpy is 2856kJ/kg; the extraction pressure of the stage assembly inlet and outlet is 0.07426MPa and 0.01588MPa respectively; the corresponding low-pressure feed water heater inlet feed water mass flow is 915.1kg/s, and the specific enthalpy is 175.9kJ/kg.
Additionally, in S6 of the present invention, the specific enthalpy and mass flow rate of the outlet steam of the previous stage group are taken as the specific enthalpy and mass flow rate of the inlet of the next stage group, so there is: the specific enthalpy of the inlet working medium of the class group is 2465kJ/kg; the mass flow of the working medium at the inlet of the class group is 1027kg/s; the specific enthalpy and mass flow rate of the outlet steam of the previous stage group can be obtained by implementing the S1-S5 of the invention on the previous stage group;
consulting a turbine operating protocol to obtain design parameters, including: the temperature design values of the working media of the stage assembly inlet and outlet are 366.9K and 329.1K respectively, the pressure design values are 0.08086MPa and 0.01750MPa respectively, the specific enthalpy design values are 2548kJ/kg and 2390kJ/kg respectively, and the humidity design values are 5.20% and 9.05% respectively;
s2, calculating the dry basis internal efficiency and the steam-water separation efficiency of each stage of groups according to the design parameters of the steam turbine:
Figure GDA0004202693470000101
wherein:
Figure GDA0004202693470000102
Figure GDA0004202693470000103
wherein eta is ref The internal efficiency of the class group in the design working condition is 85.05% as a calculation result; kappa is the logarithmic mean adiabatic index for the class group, calculated as 1.099; alpha is the Bowman factor of the class group, and the value is 1.2; y is in ref And y out ref The humidity of the inlet steam and the outlet steam of the stage group under the design working condition are 5.20% and 9.05% respectively; h is a in ref And h out ref The specific enthalpy of the inlet steam and the outlet steam of the stage group under the design working condition are 2548kJ/kg and 2355kJ/kg respectively; p is p in ref And p out ref The pressure of the steam at the inlet and the outlet of the stage group under the design working condition is 0.08086MPa and 0.01750MPa respectively; ρ in ref And ρ out ref The density of the steam inlet and outlet of the stage group under the design working condition is 0.5105kg/m respectively 3 And 0.1268kg/m 3 ；
Obtaining the dry basis internal efficiency eta of the grade group dry 0.9310%.
The steam-water separation efficiency of the stage group is calculated by adopting the following formula:
Figure GDA0004202693470000104
wherein D is dw ref Is the mass flow of the steam turbine inter-stage drainage under the design working condition, which is60.48kg/s；D in ref The mass flow of the inlet working medium of the lower-level group under the design working condition is 890.9kg/s.
Obtaining steam-water separation efficiency eta of the stage group sp 16.11%.
S3, calculating the specific enthalpy of the saturated steam after expansion in the stage group, wherein the calculation comprises the following steps:
(a) Calculating the humidity y of the inlet working medium of the grade group in Sum of specific entropy s in ：
Figure GDA0004202693470000111
s in ＝(1-y in )s V (p in )+y in s L (p in )
In the formula, h in The specific enthalpy of the working medium at the inlet of the grade group is 2465kJ/kg; p is p in The pressure of the working medium at the inlet of the class group is 0.01588MPa; h is a L (p in ) And h V (p in ) The specific enthalpies of saturated water and saturated dry steam corresponding to the pressure of the working medium at the inlet of the class group are 383.2kJ/kg and 2662kJ/kg respectively; s is(s) L (p in ) Sum s V (p in ) The specific entropy of saturated water and saturated dry steam corresponding to the pressure of the inlet working medium of the stage group is 1.210 kJ/(kg x K) and 7.459 kJ/(kg x K) respectively.
Obtaining the humidity y of the inlet working medium of the grade group in 8.647%; specific entropy s of working medium at inlet of class group in 6.919 kJ/(kg. Times.K).
(b) According to the calculated specific entropy s of the class group inlet working medium in the step (a) in Calculating the humidity y of the steam at the outlet of the stage group during isentropic expansion out,s And specific enthalpy h out,s ：
Figure GDA0004202693470000112
h exp,s ＝(1-y exp,s )h V (p out )+y exp,s h L (p out )
Wherein p is out The pressure of the working medium at the outlet of the class group is 0.01588MPa; s is(s) L (p out ) Sum s V (p out ) The specific entropy of saturated water and saturated dry steam corresponding to the pressure of the working medium at the outlet of the stage group is 0.7700 kJ/(kg x K) and 7.987 kJ/(kg x K) respectively; h is a L (p out ) And h V (p out ) The specific enthalpies of saturated water and saturated dry steam corresponding to the pressure of the working medium at the outlet of the grade group are 230.9kJ/kg and 2600kJ/kg respectively.
Obtaining the humidity y of the isentropic expansion time-class group outlet working medium exp,s 14.81%; specific enthalpy h of isentropic expansion time-class group outlet working medium exp,s 2250kJ/kg.
(c) Internal efficiency of the compute class group:
η exp ＝η dry (1-αy in )
in the method, in the process of the invention, dry the dry basis internal efficiency of the grade group is 93.10% obtained in S2; y is in Is the inlet steam humidity of the stage group, which is 8.650 percent.
Obtaining the intra-grade group efficiency eta under variable working conditions exp 83.44%.
(d) The specific enthalpy h of the isentropic expansion stage group outlet steam obtained according to (b) exp,s And (c) intra-stage group efficiency η exp And calculating the specific enthalpy and humidity of the steam after expansion in the stage group:
h exp ＝h in -η exp (h in -h exp,s )
Figure GDA0004202693470000113
obtaining the specific enthalpy h of the steam after expansion in the stage group exp 2285kJ/kg; humidity y of steam after expansion in the stage group exp 13.30%.
(e) According to the stage group outlet humidity y obtained in (d) exp Recalculating intra-stage group efficiency η exp ：
Figure GDA0004202693470000121
Obtaining intra-stage group efficiency eta exp 80.84%.
(f) Repeating (d) by using the efficiency in the stage group in (e) to obtain the specific enthalpy h of the steam after expansion in the stage group exp Humidity y exp 。
Obtaining the specific enthalpy h of the steam after expansion in the stage group exp 2291kJ/kg; humidity y of steam after expansion in the stage group exp 13.09%.
S4, calculating the specific enthalpy of saturated steam after steam-water separation by adopting the following formula:
Figure GDA0004202693470000122
wherein D is in Is the mass flow of the working medium at the inlet of the class group, 1027kg/s; η (eta) sp The steam-water separation efficiency of the grade group is 16.11% obtained in S2;
obtaining saturated steam specific enthalpy h after steam-water separation sep 2335kJ/kg.
The saturated steam humidity after steam-water separation is calculated by the following formula:
Figure GDA0004202693470000123
obtaining the saturated steam humidity y after steam-water separation sep 11.21%.
The saturated steam mass flow after steam-water separation is calculated by adopting the following formula:
D sep ＝(1-η sp y exp )D in
obtaining saturated steam mass flow D after steam-water separation sep 1005kg/s.
Specific enthalpy h of saturated steam after steam-water separation sep Specific enthalpy h of saturated steam as stage group outlet out The method comprises the steps of carrying out a first treatment on the surface of the The saturated steam humidity y after steam-water separation sep Humidity y of saturated steam as stage group outlet out 。
S5, calculating the mass flow of saturated steam after steam extraction by adopting the following formula:
D ext ＝D sep -D es
obtaining the mass flow D of saturated steam after steam extraction ext 980.8kg/s;
wherein D is es The extraction mass flow is 24.40kg/s, and is obtained by solving the following equation:
Figure GDA0004202693470000124
Figure GDA0004202693470000131
Figure GDA0004202693470000132
Figure GDA0004202693470000133
Figure GDA0004202693470000134
wherein V is V Is the volume of steam in the feed water heater, which is 60.28m 3 ；ρ V Is saturated dry steam with density of 0.2864kg/m 3 ；h L And h V Saturated water and saturated dry steam specific enthalpies of 230.7kJ/kg and 2601kJ/kg respectively; d (D) dw,in The mass flow rate of the upper-level water heater is 0kg/s because the upper-level water heater has no water drain; d (D) con Is the mass flow of condensation water, 46.04kg/s; q (Q) V The heat flows of the steam condensing section and the hydrophobic cooling section are calculated to be 1.761 multiplied by 10 5 kW；S V The heat exchange area of the steam condensation section of the feedwater heater is 1600m 2 ；T es The extraction temperature is 328.3K; t (T) fw Is the temperature distribution of the water supply from 314.8K to 317.7K; k (K) fw And K es The surface heat transfer coefficients of the feed water and steam, respectively, were 10.73 kW/(m), respectively 2 * K) Up to 11.78 kW/(m) 2 * K) And 10.72 kW/(m) 2 * K) Up to 80.47 kW/(m) 2 * K) Is a distribution of (3); w (w) fw Is the distribution of the flow rate of the feed water, from 2.243m/s to 2.255 m/s; ρ fw Is the density of the water supply, is 991.5kg/m 3 To 986.2kg/m 3 Is a distribution of (3); lambda (lambda) fw Is the distribution of the thermal conductivity of the feedwater, 0.6346 kW/(m K) to 0.6480 kW/(m K); lambda (lambda) L,es The heat conductivity of saturated water corresponding to the extraction pressure is 0.6480 kW/(m.times.K); c p,fw Is the constant pressure specific heat capacity of the feed water, and is the distribution of 4.169 kW/(kg x K) to 4.172 kW/(kg x K); mu (mu) fw Sum mu L,es The dynamic viscosity of the water supply and the saturated hydrodynamic viscosity corresponding to the extraction pressure are 6.158 multiplied by 10 respectively -4 Pa.s to 5.033 ×10 -4 Distribution of Pa.s; mu (mu) L,es Is saturated hydrodynamic viscosity corresponding to the extraction pressure of 5.032 multiplied by 10 -4 Pa·s；ρ L,es Is the saturated water density corresponding to the extraction pressure, 987.3kg/m 3 The method comprises the steps of carrying out a first treatment on the surface of the g is the gravity acceleration, 9.8m/s 2 ；d i The inner diameter of the heat exchange tube is 0.0130m; d, d o The external diameter of a heat exchange tube of the feed water heater is 0.0160m;
saturated steam mass flow D after steam extraction ext Mass flow D of saturated steam as stage bank outlet out 。
S6, taking the specific enthalpy and the mass flow of the steam at the outlet of the previous stage group as the specific enthalpy and the mass flow of the steam at the inlet of the next stage group, repeating S3-S5, and sequentially calculating the specific enthalpy and the mass flow of the saturated steam at the outlet of each stage group until all the stage groups are calculated; specific enthalpy h of the outlet saturated steam of the last stage group out Humidity y out And mass flow rate D out Specific enthalpy h respectively used as exhaust steam of saturated steam turbine exh Humidity y exh And mass flow rate D exh The method comprises the steps of carrying out a first treatment on the surface of the Obtaining the specific enthalpy h of exhaust steam of the saturated steam turbine exh 2289kJ/kg; humidity y exh 11.57%; mass flow rate D exh 980.8kg/s；
S7, calculating the dead steam volume flow of the saturated steam turbine by adopting the following formula:
Figure GDA0004202693470000141
wherein p is exh Is the dead steam pressure of a saturated steam turbine, 0.006210MPa; ρ L (p exh ) And ρ V (p exh ) Corresponding to the exhaust steam pressure of the steam turbine and the saturated water density and the saturated dry steam density are 993.3kg/m respectively 3 And 0.04352kg/m 3 。
In the embodiment, the exhaust steam volume flow V of the saturated steam turbine is obtained exh 2608m 3 S; the exhaust steam humidity of the saturated steam turbine is y in S6 exh 11.57%.
According to the real-time determination method for the dead steam volume flow and the humidity of the saturated steam turbine, through parameter design in each step, the accuracy of parameters is improved, the method can be used for calculating the volume flow and the humidity of the dead steam of the saturated steam turbine on line, the problem that the variable cannot be measured in real time is solved, and the method has important significance in monitoring the operation state of the saturated steam turbine.
The results obtained by the embodiment of the invention can be directly used for real-time online monitoring of the nuclear power saturated steam turbine, specifically, after the exhaust steam volume flow of the saturated steam turbine and the exhaust steam humidity of the saturated steam turbine are obtained, the results can be compared according to the set monitoring threshold value, and early warning is carried out when the results exceed the set monitoring threshold value, so that real-time online monitoring is realized, and an important auxiliary effect is realized for the operation monitoring of the nuclear power saturated steam turbine.
The foregoing describes specific embodiments of the present invention. It is to be understood that the invention is not limited to the particular embodiments described above, and that various changes and modifications may be made by one skilled in the art within the scope of the claims without affecting the spirit of the invention.

Claims (9)

1. A real-time determination method for exhaust steam volume flow and humidity of a saturated steam turbine is characterized by comprising the following steps:
s1: acquiring equipment structural parameters of a low-pressure cylinder and a low-pressure feed water heater of a steam turbine, design parameters of the steam turbine and operation data of the low-pressure cylinder and the low-pressure feed water heater of the steam turbine at given time; the operation data includes: the low-pressure cylinder is characterized by comprising the mass flow, specific enthalpy, humidity and pressure of an inlet working medium, the extraction pressure of an outlet of each stage, the mass flow and specific enthalpy of inlet and outlet water supply of a low-pressure feed water heater;
s2: calculating the dry basis internal efficiency and the steam-water separation efficiency of each stage of groups according to the design parameters of the steam turbine of the S1;
s3: calculating the specific enthalpy of the saturated steam after expansion in the stage group according to the specific enthalpy and pressure of the working medium at the inlet of the low-pressure cylinder in S1, the extraction pressure of the inlet and outlet of each stage and the dry basis internal efficiency of S2;
s4: according to the steam-water separation efficiency of the stage group obtained in the step S2 and the specific enthalpy of the saturated steam obtained in the step S3 after expansion in the stage group, calculating the mass flow, specific enthalpy and humidity of the saturated steam after steam-water separation, and taking the specific enthalpy of the saturated steam after steam-water separation as the specific enthalpy of the saturated steam at the outlet of the stage group;
s5: according to the water supply mass flow and specific enthalpy of the inlet and outlet of the low-pressure feed water heater in the S1 operation data and the specific enthalpy of the saturated steam of the outlet of the stage group obtained in the S4, calculating the mass flow of the saturated steam after steam extraction, and taking the mass flow of the saturated steam after steam extraction as the mass flow of the saturated steam of the outlet of the stage group;
s6: taking the specific enthalpy and the mass flow of the steam at the outlet of the previous stage group as the specific enthalpy and the mass flow of the steam at the inlet of the next stage group, repeating S3-S5, and sequentially calculating the specific enthalpy and the mass flow of the saturated steam at the outlet of each stage group until all the stage groups are calculated; specific enthalpy h of the outlet saturated steam of the last stage group out Humidity y out And mass flow rate D out Specific enthalpy h respectively used as exhaust steam of saturated steam turbine exh Humidity y exh And mass flow rate D exh ；
S7: and (3) calculating the dead steam volume flow of the saturated steam turbine according to the specific enthalpy and the mass flow of the dead steam in the step S6.
2. The method for determining the dead steam volume flow and the humidity of the saturated steam turbine in real time according to claim 1, wherein in the step S2, the dry basis internal efficiency and the steam-water separation efficiency of each stage group are calculated according to the design parameters of the turbine, and the following formula is adopted:
Figure FDA0004202693460000011
wherein:
Figure FDA0004202693460000012
Figure FDA0004202693460000021
wherein eta is dry Is the dry basis internal efficiency of the class group, and has no dimension; η (eta) ref The internal efficiency of the class group in the design working condition is zero; alpha is the Bowman factor of the class group, dimensionless; y is in ref And y out ref The humidity of the working medium at the inlet and outlet of the class group under the design working condition is dimensionless; h is a in ref And h out ref The specific enthalpy of the inlet working medium and the outlet working medium of the class group under the design working condition are kJ/kg respectively; p is p in ref And p out ref The pressure of the working medium at the inlet and outlet of the class group under the design working condition is MPa; ρ in ref And ρ out ref The density of the working medium at the inlet and outlet of the stage group under the design working condition is kg/m 3 The method comprises the steps of carrying out a first treatment on the surface of the Kappa is the logarithmic average adiabatic index of the class group, dimensionless;
the steam-water separation efficiency of the stage group is calculated by adopting the following formula:
Figure FDA0004202693460000022
wherein eta is sp The steam-water separation efficiency of the stage group is dimensionless; d (D) dw ref The mass flow rate of the steam turbine interstage drainage under the design working condition is kg/s; d (D) in ref Is the mass flow of the inlet working medium of the lower-level group under the design working condition, kg/s.
3. The method for determining the dead steam volume flow and the humidity of the saturated steam turbine in real time according to claim 1, wherein in S3, the calculating the specific enthalpy of the saturated steam after expansion in the stage group includes:
(a) Calculating the humidity y of the inlet working medium of the grade group in Sum of specific entropy s in ：
Figure FDA0004202693460000023
s in ＝(1-y in )s V (p in )+y in s L (p in )
Wherein y is in The humidity of the working medium at the inlet of the class group is dimensionless; h is a in Is the specific enthalpy of the inlet working medium of the class group, kJ/kg; p is p in Is the pressure of the working medium at the inlet of the class group and MPa; s is(s) in Is the specific entropy of the inlet working medium of the class group, kJ/(kg. Times.K); h is a L (p in ) And h V (p in ) The specific enthalpy of saturated water and saturated dry steam corresponding to the pressure of the working medium at the inlet of the grade group are kJ/kg respectively; s is(s) L (p in ) Sum s V (p in ) The specific entropy of saturated water and saturated dry steam corresponding to the pressure of the working medium at the inlet of the stage group is kJ/(kg x K);
(b) According to the calculated specific entropy s of the class group inlet working medium in the step (a) in Calculating the humidity y of the outlet working medium during isentropic expansion exp,s And specific enthalpy h exp,s ：
Figure FDA0004202693460000024
h exp,s ＝(1-y exp,s )h V (p out )+y exp,s h L (p out )
Wherein y is exp,s The humidity of the working medium at the outlet of the class group during isentropic expansion is dimensionless; h is a exp,s The specific enthalpy of the working medium at the outlet of the class group during isentropic expansion is kJ/kg; p is p out Is the pressure of working medium at the outlet of the class group and MPa; s is(s) L (p out ) Sum s V (p out ) The specific entropy of saturated water and saturated dry steam corresponding to the pressure of the working medium at the outlet of the stage group is kJ/(kg x K); h is a L (p out ) And h V (p out ) The specific enthalpy of saturated water and saturated dry steam corresponding to the pressure of the working medium at the outlet of the class group are kJ/kg respectively;
(c) Internal efficiency of the compute class group:
η exp ＝η dry (1-αy in )
wherein eta is exp The efficiency in the class group under the variable working condition is dimensionless; η (eta) dry Is the dry basis internal efficiency of the class group, and has no dimension; y is in The humidity of the working medium at the inlet of the class group is dimensionless;
(d) The specific enthalpy h of the isentropic expansion time-class group outlet working medium obtained according to (b) exp,s And (c) intra-stage group efficiency η exp And calculating the specific enthalpy and humidity of the steam after expansion in the stage group:
h exp ＝h in -η exp (h in -h exp,s )
Figure FDA0004202693460000031
in the formula, h exp Is the specific enthalpy of the steam after expansion in the stage group, kJ/kg; y is exp The humidity of the steam after expansion in the stage group is dimensionless; h is a L (p out ) And h V (p out ) The specific enthalpy of saturated water and saturated dry steam corresponding to the pressure of the working medium at the outlet of the class group are kJ/kg respectively;
(e) According to (d)Stage group outlet humidity y exp Recalculating intra-stage group efficiency η exp ：
Figure FDA0004202693460000032
(f) Intra-stage group efficiency η obtained in (e) exp Substituting back (d), repeating (d) to obtain specific enthalpy h of steam after expansion in the stage group exp Humidity y exp 。
4. The method for determining the dead steam volume flow and the humidity of the saturated steam turbine in real time according to claim 1, wherein in S4, the specific enthalpy of the saturated steam after steam-water separation is calculated by adopting the following formula:
Figure FDA0004202693460000033
in the formula, h sep The specific enthalpy of saturated steam after steam-water separation is kJ/kg; d (D) in Is the mass flow of the working medium at the inlet of the class group, kg/s; h is a exp Is the specific enthalpy of saturated steam after expansion in the stage group, kJ/kg; η (eta) sp The steam-water separation efficiency of the stage group is dimensionless; y is exp The humidity of the steam after expansion in the stage group is dimensionless; p is p out Is the pressure of working medium at the outlet of the class group and MPa; h is a L (p out ) Is the specific enthalpy of saturated water corresponding to the pressure of the working medium at the outlet of the grade group, kJ/kg;
the saturated steam humidity after steam-water separation is calculated by the following formula:
Figure FDA0004202693460000034
wherein y is sep The saturated steam humidity after steam-water separation is dimensionless; h is a V (p out ) Is the specific enthalpy of saturated dry steam corresponding to the pressure of the working medium at the outlet of the stage group, kJ/kg; h is a L (p out ) Is a class groupSpecific enthalpy of saturated water corresponding to the pressure of the outlet working medium;
the saturated steam mass flow after steam-water separation is calculated by adopting the following formula:
D sep ＝(1-η sp y exp )D in
wherein D is sep The mass flow of saturated steam after steam-water separation is kg/s; d (D) in Is the mass flow rate of saturated steam at the inlet of the stage group, kg/s;
specific enthalpy h of saturated steam after steam-water separation sep Specific enthalpy h of saturated steam as stage group outlet out The method comprises the steps of carrying out a first treatment on the surface of the The saturated steam humidity y after steam-water separation sep Humidity y of saturated steam as stage group outlet out 。
5. The method for determining the dead steam volume flow and the humidity of the saturated steam turbine in real time according to claim 1, wherein in the step S5, the mass flow of the saturated steam after steam extraction is calculated by adopting the following formula:
D ext ＝D sep -D es
wherein D is ext Is the mass flow of saturated steam after steam extraction, kg/s; d (D) sep The mass flow of saturated steam after steam-water separation is kg/s; d (D) es Is the extraction mass flow, kg/s;
the mass flow rate D of saturated steam after steam extraction ext Mass flow D of saturated steam as stage bank outlet out 。
6. The method for determining the dead steam volume flow and the humidity of the saturated steam turbine in real time according to claim 5, wherein the extraction mass flow D es Obtained by solving the following equation set:
Figure FDA0004202693460000041
Figure FDA0004202693460000042
Figure FDA0004202693460000043
Figure FDA0004202693460000044
Figure FDA0004202693460000045
wherein V is V Is the steam volume in the feed water heater, m 3 ；ρ V Is saturated dry steam density, kg/m 3 ；h L And h V Saturated water and saturated dry steam specific enthalpy, kJ/kg respectively; d (D) es Is the extraction mass flow, kg/s; d (D) dw,in Is the hydrophobic mass flow rate of the upper-level feed water heater, kg/s; h is a dw,in Is the hydrophobic specific enthalpy of the upper-level feed water heater, kJ/kg; d (D) con Is the mass flow of the condensed water, kg/s; q (Q) V Is the heat flow of the steam condensing section and the hydrophobic cooling section, kW; s is S V Is the heat exchange area, m of the steam condensation section of the feedwater heater 2 ；T es And T fw The steam extraction temperature and the water supply temperature are respectively, K; k (K) fw And K es Surface heat transfer coefficients, kW/(m), of feedwater and steam respectively 2 *K)；w fw Is the flow rate of the feed water, m/s; ρ fw Is the density of the water supply, kg/m 3 ，λ fw And lambda (lambda) L,es The heat conductivity of saturated water corresponding to the heat conductivity of water supply and the steam extraction pressure are kW/(m.times.K); c p,fw Is the constant pressure specific heat capacity of the feed water, kW/(kg. Times.K); mu (mu) fw Sum mu L,es The dynamic viscosity of the water supply and the saturated hydrodynamic viscosity corresponding to the extraction pressure are Pa.s respectively; d, d i Is the inner diameter of a heat exchange tube, m; g is the gravity acceleration, 9.8m/s 2 ；ρ L,es Is saturated water corresponding to the extraction pressureDensity of kg/m 3 ；d o Is the outer diameter m of a heat exchange tube of the feed water heater.
7. The method for determining the dead steam volume flow and the humidity of the saturated steam turbine in real time according to claim 1, wherein in S7, the dead steam volume flow of the saturated steam turbine is calculated by adopting the following formula:
Figure FDA0004202693460000051
wherein V is exh Is the dead steam volume flow of the saturated steam turbine, m 3 /s；D exh S6, obtaining the dead steam mass flow of the saturated steam turbine, and kg/S; y is exh S6, obtaining the exhaust steam humidity of the saturated steam turbine, wherein the exhaust steam humidity is dimensionless; p is p exh Is the dead steam pressure of a saturated steam turbine and MPa; ρ L (p exh ) And ρ V (p exh ) The pressure of exhaust steam of the steam turbine corresponds to the saturated water density and the saturated dry steam density, kg/m 3 ；
The exhaust steam humidity of the saturated steam turbine is y in S6 exh 。
8. A readable medium having instructions stored thereon which, when executed on an electronic device, cause the electronic device to perform the method for real-time determination of exhaust steam volumetric flow and humidity of a saturated steam turbine according to any one of claims 1 to 7.
9. An electronic device comprising a memory, a processor and a computer program stored on the memory and executable on the processor, wherein the processor is configured to perform the method of real-time determination of exhaust steam volumetric flow and humidity of a saturated steam turbine as defined in any one of claims 1 to 7 when the program is executed by the processor.
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JP4155495B2 (en) * 2002-04-10 2008-09-24 株式会社東芝 Cooling equipment for reactor isolation
CN103117101B (en) * 2013-01-19 2015-09-30 哈尔滨工程大学 For the start and stop servicing unit of integral reactor and the cold start-up method of integral reactor
CN110160113A (en) * 2019-04-29 2019-08-23 中广核工程有限公司 A kind of nuclear power plant's heating system and its heating method
CN112127958A (en) * 2020-08-28 2020-12-25 中核核电运行管理有限公司 Device and method for determining steam extraction parameters of nuclear turbine

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