Course work
Thermal calculation of the turbine K-500-240
Introduction
Initial data
1. Short description turbine designs
Thermal calculation of the turbine plant
1 Construction of steam expansion process in h-s diagram
2.2 Calculation of the regenerative feedwater heating system
Selection of the number of stages of a given cylinder, breakdown of steam enthalpy drops by stages
1 Distribution of heat drops over the cylinder stages of a steam turbine
4. Estimation of turbine power for a given steam flow
Detailed thermal and gas-dynamic calculation of a given stage
6. Rationale for the choice of HA and RK profiles according to the atlas
6.1 Calculation of the nozzle array
2 Calculation of converging nozzles
3 Calculation of the working lattice
4 Relative blade efficiency of the stage
7. Strength substantiation of elements
7.1 Calculation of the working blade of the last stage of the compartment for bending and tension
2 Construction of the vibration diagram of the working blade of the last stage
3 Determining the critical frequency of the rotor
Conclusion
Bibliography
Application
Introduction
For P-type turbines, the design steam flow is taken to be the steam flow to the turbine at rated power.
The thermal calculation of the turbine is carried out in order to determine the main dimensions and characteristics of the flow path: the number and diameters of the stages, the heights of their nozzle and working gratings and types of profiles, efficiency. stages, individual cylinders and the turbine as a whole.
The thermal calculation of the turbine is performed for a given power, given initial and final steam parameters, and the number of revolutions; when designing a turbine with controlled steam extractions, in addition, for given pressures and the amount of extractions.
The purpose of the course project is to acquire practical skills for performing design and verification calculations of turbines operating both on steam and on gases of any composition.
cylinder blade steam turbine
Initial data
Initial data:
Turbine prototype K-500-240;
Rated electrical load N uh =530 MW; Initial parameters: P 0=23.5 MPa, t 0=520°С, η 0i =0,87;
Final pressure: P TO =5.5 kPa; Feed water temperature after the last heater t pv =260°С; Turbine rotor speed n=3000 rpm. 1. Brief description of the turbine design
Steam turbine K-500-240 is a four-cylinder condensing turbine with reheating of steam, four exhausts to the condenser and a developed system of regenerative feed water heating. Unregulated steam extractions for the station's own needs are possible. Table 1 Turbine parameters Turbine parametersK-500-240Nominal/maximum power, MW525/535Initial parameters parapressure, MPa23.5temperature, °С520Steam parameters after superheatingpressure, MPa4temperature, °С520Rated fresh steam consumption, t/h1 650Maximum productivity of heat extraction, GJ/h210Length of the working part of the blade of the last stage, mm960Rated cooling temperature flowing water , °С12Cooling water consumption through the condenser, m 3/h51 480 2. Thermal calculation of the turbine plant
2.1 Construction of steam expansion process in h-s diagram
Point 0: determined by the given steam parameters = 23.5 MPa and = 0.995. According to the h-s diagram, the remaining parameters of point 0 are determined. Point 0: segment 0-0 corresponds to the throttling process on stop valves. In this case, the pressure loss is assumed to be 2%. The enthalpy does not change during throttling, i.e. h0=h0=3258.9 kJ/kg. Based on pressure and enthalpy, point 0 is constructed and its parameters are determined. Point A: segment 0-A corresponds to the process of isentropic expansion of steam in the HPC to a pressure of =3.72 MPa. hA = 2809.24 kJ/kg. Point 3: segment 0-3 corresponds to the actual process of steam expansion in the HPC, taking into account internal energy losses in the flow path. When assessing, we accept the value of the internal relative efficiency of the HPC in the amount of 87%. h3 = h0 - h0iCVD (h0 - hA) = 3258.9-0.87(3258.9- 2809.24) = 2875.55 kJ/kg 3.89 MPa. Point C: corresponds to the state of the steam after the separator. The degree of dryness after the separator is taken as XC = 0.99. Point D: corresponds to the state of steam after SSH and is determined by the given parameters of steam after reheating tD = 520 250 0C. The loss of pressure in the SPP and in the receiver from the SPP to the TsSND is assumed to be 8%. 0.92 = 0.92 3.89 = 3.58 MPa. Point N: segment D-N corresponds to the process of isentropic expansion of steam in the HPC and LPC to the final pressure = 0.0055 0.05 MPa, = 2199.56 kJ/kg. Point K: segment D-K corresponds to the actual process of steam expansion in the HPC and LPC of the turbine, taking into account internal losses. When assessing, we accept the value of the internal relative efficiency in the IPC and LPC in the amount of 87%. H0iDND (-) \u003d 3493.85 - 0.87. (3493.85 - 2199.56) \u003d 2367.82 kJ / kg 0.0055 MPa. After constructing the expansion process, points are plotted corresponding to the state of steam in unregulated turbine extractions. The points are located at the intersection of the line of the expansion process and isobars corresponding to the pressures in the selections. The pressures in the HP extractions are taken according to the principle of uniform division of the expansion process into the number of stages: 14.1 MPa; = 8.64 MPa; = 4.94 MPa. The pressures in the selections of the HP and LPC are taken according to the principle of uneven separation of the expansion process from smaller drops per stage to larger ones with an increase in the stage number (dimensions for 7 stages are given below): P4=4.72 MPa; P5=0.74 MPa; P6=0.26 MPa; P7=0.123 MPa Table 2 Summary table of steam parameters during expansion Process pointPressure, p, MPaTemperature, t, 0C Degree of dryness, xSpecific volume, v, m 3/kgEnthalpy, h, kJ/kg0 0 1 2 3 A С D N K 4 5 6 723.5 23.03 14.1 8.64 3.89 3.89 6.76 3.8 0.0055 0.0055 4.72 0.84 0.26 0, 123520 518.12 442.6 398.7 269.76 253.11 349.3 510 73.2 73.2 421.7 223.9 167.3 119.70.995 0.994 0.929 0.902 0.874 0.873 0, 990 - 0.823 0.874 - 0.977 0.939 0.9120.0127 0.013 0.0195 0.0936 0.0556 0.054 0.1751 0.0937 18.387 19.522 0.3586 1.1410 2.5650 6.69273258.9 3258.9 3150.8 173.9 2818.3 2818.3 3021.37 3493.85 2637.18 2637.18 3553.91 2891.83 2800.69 2714.72 Rice. 1. Steam expansion process in h-s diagram 2.2 Calculation of the regenerative feedwater heating system
Feed water temperature: t pv =260°С Final pressure: P TO = 5.5 kPa and the temperature is .
Initial parameters: P 0=23.5 MPa, t 0=530°С, η 0i =0,87.
Heating of feed water in one HPH: I take heat in the deaerator and feed water temperature at the deaerator inlet: Water heating in one HDPE: Temperature in the condenser: We select the condensate pump according to the factory data. Its head is 3.96 MPa. Find the pressure at the outlet of the condensate pump. We find the heating of water in the condensate pump: In additional heaters we accept Assuming losses in low-pressure heaters, we determine the pressure behind the HDPE: We find the temperature of the main condensate at the inlet to the deaerator, having previously taken .
Provided that the heating in HDPE is uniform, we find the temperature behind each HDPE. K-500-240/3000 uses feed pump PT-3750-75 with parameters: head MPa; Efficiency 80% according to GOST 24464-80. We find the pressure at the outlet and outlet PN. Let's find the heating in the feed pump. Find the temperature of the feed water at the point .
Let us determine the temperatures after each HPT. Assuming the loss in the HPH is 0.7 MPa, we find the pressure behind each HPH: We accept subheating to saturation temperature for HDPE - 4 0C, for LDPE - 6 0C and find the temperature of the drains, and find the pressure of the heating steam in the heaters: 3. Choice of the number of stages of a given cylinder, breakdown of steam enthalpy drops into stages
3.1 Distribution of heat drops over the cylinder stages of a steam turbine
Thermal calculation of the control stage:
Calculation of the first section: We determine the available heat drop of the HPC: kJ/kg where is the dependence and,. m/kg; m/s. where is the dependence of pressure at the end of the section, kJ / kg We determine the actual heat drop of HPC: kJ/kg Calculation of the second section: We determine the available heat drop of the CSD: We determine the internal relative efficiency: where - dependence on and, % Determine the volume flow of steam: The ratio of the pressure at the inlet to the section to the pressure at the outlet of the section: where is the pressure dependence at the end of the section, . Relative loss with output speed: Pressure dependence at the end of the section. We determine the actual heat drop of the CSD: kJ/kg Calculation of the third section: We determine the available heat drop of the LPC: We determine the internal relative efficiency: Dependence, %. Determine the volume flow of steam: The ratio of the pressure at the entrance to the section to the pressure at the exit from the section: Dependence of pressure at the end of the section, . Relative loss with output speed: where is the pressure dependence at the end of the section, kJ/kg. Dependence of the reduced theoretical moisture content, % Determine the reduced theoretical final moisture content: We determine the final humidity in the theoretical process: We determine the available drop below the line of dry saturated steam (X=1) in the area of wet steam: kJ/kg Determine the average pressure: (+)/2=(0.2+0.0055)/2=0.1 MPa We determine the actual heat drop of the LPC: We determine the useful-used heat difference of the turbine: kJ/kg We determine the corrected steam flow rate for the turbine: Thermal calculation of unregulated HPC stages: Determine the average step diameter: where - the degree of reaction of the stage is taken within,% Effective exit angle of the flow from the nozzle array: for a single-row stage, . Lattice velocity coefficient, . Reactive isentropic steam velocity calculated from the available stage difference: Circumferential speed of rotation of the disc on the average diameter of the step: Dependence. Average step diameter: 4. Estimation of turbine power for a given steam flow
Based on the terms of reference: N uh =530 MW - rated electrical load; R 0=23.5 MPa - steam pressure at the turbine inlet; t 0=530 С 0- steam temperature at the turbine inlet; η 0=0,87;
P To =5.5 kPa - steam pressure at the outlet of the turbine. Feed water temperature after the last heater t pv =260°С; Turbine rotor speed n=3000 rpm. Steam pressure in front of the nozzles of the first control stage: Steam pressure behind the last stage of the turbine: Pressure downstream HPC at steam outlet to reheat: Steam pressure at the outlet to the CSD in the reheat field: Available heat drop HPC: Steam consumption for the turbine according to a predetermined efficiency factor: We set the available heat drop of the HPC control stage: kJ/kg Internal relative efficiency of control stage: Useful thermal difference in the control stage: KJ/kg m / kg (according to the H-S diagram). Pressure behind control stage: 5. Detailed thermal and gas-dynamic calculation of a given stage
Calculation of the first compartment: The diameter of the first unregulated step is determined: where - for a two-crown stage, mm. Speed ratio: where - the degree of reaction of the working grid of the first stage is taken within, p.30 Nozzle array velocity coefficient, . The available thermal difference of the first unregulated stage according to the braking parameters before the stage: kJ/kg Thermal difference in the nozzle grate: kJ/kg Nozzle height: where is the specific volume of steam at the end of the isentropic expansion in the nozzles, m/kg (according to the H-S diagram). Theoretical steam flow rate from the nozzle array: where is the flow rate of the nozzle array,; The degree of partiality of the step, . The effective exit angle of the flow from the nozzle array is taken within, . Height of the working grid of the first stage: where is the internal overlap, mm. External overlap, mm. Step root diameter: This diameter is taken constant for the compartment: where is the isentropic thermal difference of the first compartment; kJ/kg (according to H-S diagram). kJ/kg The available thermal difference in terms of the static parameters of the steam ahead of the stage, taken for all stages of the compartment, except for the first one (for the first, the available difference in terms of braking parameters and static parameters are equal) is calculated by the formula: kJ/kg Heat recovery ratio: For a process in the area of superheated steam: Discrepancy: kJ/kg Correction for thermal difference: first stage: kJ/kg other steps: kJ/kg Adjusted heat drop for static steam parameters: first stage: kJ/kg other steps: kJ/kg Product of height and diameter. The height of the blade of the working grate of any stage of each compartment: Step diameter: Nozzle height. Table 3 High pressure part summary table Name of quantitiesDesignationDimensionFormula, method of determination Step number1234Corr. step heat drop by static parameters kJ/kg44.1 41.64 Specific volume of steam behind the working grate m /kgFrom H-S diagrams 0.02350.0270.030.034Product of blade height and step diameter m 0.03640.04360.0480.055 Height of working grid m 0.0420.0480.0520.0582Height of nozzle array m 0.0390.0450.0490.0542Step diameter m 0,930,9360,940,9462
Calculation of the second compartment: Thermal difference according to the braking parameters of the stage of the second compartment: 2. Thermal difference of any stage except the first: kJ/kg 3. Thermal difference to the nozzle array of the first stage: kJ/kg 4. Fictitious speed: 5. Circumferential speed on the average diameter of the working blades of the 1st stage: 6. Average step diameter of the second compartment: 7. Height of the 7th stage nozzle grate: where is the specific volume of steam at the end of isentropic expansion in the nozzles, m/kg (according to the H-S diagram) Nozzle grate flow rate, . where is the degree of partiality of the step, . The effective exit angle of the flow from the nozzle array is taken within, . 8. Height of the working grid of the first stage: where-internal overlap: mm. External overlap, mm. Step root diameter: This diameter is taken constant for the compartment: Number of compartment steps: where is the isentropic thermal difference of the compartment, kJ/kg (according to the H-S diagram). kJ/kg Approximate number of compartment (cylinder) stages: Product of height and diameter: The value of specific volumes and according to the H-S diagram after the distribution of the difference per compartment, in steps. The height of the blade of the working grate of any stage of each compartment: 13. Step diameter: 14. The height of the nozzle array. Table 4 High pressure part summary table Name of quantitiesDesignationDimensionFormula, method of determination Step number 12345Corr. step heat drop according to static parameters kJ/kg34.8 6. Rationale for the choice of HA and RK profiles according to the atlas
6.1 Calculation of the nozzle array
Determining the type of nozzle array: Available thermal difference of the nozzle array: kJ/kg Theoretical steam velocity at the outlet of the nozzle array with isentropic expansion: Mach number for theoretical process in nozzles: The speed of sound at the outlet of the nozzle array pi isentropic outflow: where - pressure behind the nozzles (according to the H-S diagram), MPa; Theoretical specific volume behind the nozzles (according to the H-S diagram), m/kg; The indicator, for superheated steam,. When using grating profiles with tapering channels. 6.2 Calculation of converging nozzles
Calculation of converging nozzles at subcritical outflow: We determine the outlet section of the narrowing nozzles: where is the flow rate of the nozzle array,. The amount of steam flowing through the front end seal of the turbine: The product of the degree of partiality of the stage and the height of the nozzle array: Optimal degree of partiality (for a single-crown stage): Nozzle height: Energy loss in nozzles: kJ/kg where is the velocity coefficient of the nozzle array, . Lattice type: S-90-12A. According to the characteristic of the selected grating, we take the relative step: Grating pitch: mm where - depending on the chosen lattice, . The outlet width of the channel of the nozzle array: Number of channels: 6.3 Calculation of the working grid
The thermal difference used in the nozzles is plotted from a point in the H-S diagram. Thermal difference used on the blades: kJ/kg Input speed to the working grid of the first crown: Construction of the input velocity triangle: where is the relative velocity into the working grating of the first row Theoretical relative velocity at the outlet of the working grating: Mach number: where for superheated steam; Pressure behind the working grate (according to the H-S diagram), MPa. Specific volume behind the working grate (according to the H-S diagram), m/s. The output area of the working grating according to the continuity equation: msm2 mm2 where is the flow rate of the working grate, . Blade height (constant height): where is the size of the overlap, mm; Overlap size, mm; profile type of the working grating R-23-14A, see. Relative step, . Lattice step: Number of channels: Angle of steam exit from the working grate: The actual relative speed of steam exit from the working grate: where is the speed coefficient. Absolute speed of steam at the outlet, m/s. The exit angle of the flow in absolute motion (determined from the exit velocity triangle). 6.4 Relative blade efficiency of the stage
According to energy losses in the flow path: Energy loss in working grids: kJ/kg Energy loss with output speed: kJ/kg According to speed projections: Relative loss from partial steam supply: Where - relative value ventilation losses; Relative value of losses at the end of arcs of nozzle segments; Degree of partiality:; Percentage of the circumference occupied by the casing. The relative value of friction losses: Rice. 2. Velocity triangles of the 1st stage of HPC Rice. 3. Velocity triangles of the 11th stage of HPC Guide apparatus of the first stage: Based on the calculation of the velocity triangles, the choice of blade profiles for the guide and working apparatus is made. For the guide vane on the exit angle α1=14° the subsonic profile S-9015A is selected. Rice. 4. Blade profile for guide and working apparatus 1=0.150 m. To provide α1=14 ° profile installation angle α y =54°. Profile chord: Working grid of the first stage: For a working grate along the exit angle β2= 23° profile R-3525A is selected. Rice. 5. Profile R-3525A The width of the working grid is selected according to the prototype: 2\u003d 0.0676 m. To provide β2= 23° installation angle of the profile is equal to β y =71°. Relative lattice step t=0.62 Profile chord: Guide apparatus 11 steps: For the guide vane on the exit angle α1=14 ° the subsonic airfoil S-9015A is selected. Rice. 6. Blade profile for guide and working apparatus The width of the guide apparatus is selected according to the prototype: B 1\u003d 0.142 m. To provide α1=14° profile installation angle α y =54°. Relative lattice step t=0.62 Profile chord: 7. Strength substantiation of elements
7.1 Calculation of the working blade of the last stage of the compartment for bending and tension
When calculating the strength of the rotor blade feather, the following forces should be taken into account: Tensile and bending stresses are calculated in the most stressed - the root section of the blade. The tensile stress in the root section of a constant profile blade is defined as: where is the density of the blade material; Angular speed of rotation; 0.13 m - blade length; Average blade radius: where is the peripheral radius Unloading factor Let us determine the safety factor for the yield strength. For the manufacture of blades, steel 20X13 was chosen, for which the yield strength at a temperature equal to =480 MPa. Thus, the margin of safety is: Bending moment in the root section: where is the aerodynamic load in the circumferential and axial directions: where are the projections of the absolute steam velocities on the corresponding axes Pressure before and after the working grate of the last stage Specific volume at the outlet of the last stage (CVD) 0.149 m3/kg; Step of the working grid; Maximum bending stresses (tensions) in the root section of the edge: where is the minimum moment of inertia of the profile section: where is the profile chord; Maximum profile thickness; Maximum deflection of the middle line of the profile 7.2 Construction of the vibration diagram of the working blade of the last stage
Frequency of natural oscillations of a cantilever blade of constant cross section: where is the first natural frequency; Second natural frequency; Blade length, 0.13; r is the density of the material,; Characteristic coefficient of the first natural frequency; Characteristic coefficient of the second natural frequency; Modulus of elasticity of the material; The minimum moment of inertia of the profile section,; Cross-sectional area, . The dynamic speed is determined by the formula: where is the natural frequency of the blade, taking into account rotation; Static natural frequency (when the rotor is stationary); Rotor rotation frequency, ; B - coefficient depending on the geometry of the blade (from the fan). Rice. 7. Vibration diagram of the working blade of the last stage 7.3 Determining the critical frequency of the rotor
Calculation of the critical rotor speed:
where D = 916 mm; L = 4.12 m; V = 2.71 m 3;
r = 7,82× 103 kg/m 3.
G=V ×r× g = 2.71 × 7,82× 103 × 9.81 = 208169 N. Conclusion
The turbine is a unique engine, so its applications are diverse: from powerful power plants thermal and nuclear power plants to low-power turbines of mini-CHPs, power transport units and turbocharged units of diesel internal combustion engines. A steam turbine is an engine in which the potential energy of superheated steam is converted into kinetic energy and then into mechanical energy rotor rotation. In this course project, a thermal calculation of the K-500-240 turbine was made. The purpose of the course project is to acquire practical skills for performing design and verification calculations of turbines operating both on steam and on gases of any composition. Bibliography
1. Rivkin S.L., Aleksandrov A.A. Thermophysical properties of water and water vapor - M.: Energia, 1980. - 424 p. Equations for calculating the thermophysical properties of water and steam on a computer: Operational circular No. Ts-06-84 (t) / Ed. Rivkina S.L. - M.: Glavtekhupravlenie for the operation of energy systems, 1984. - 8 s. Rivkin S.L. Thermodynamic properties of air and fuel combustion products. - 2nd ed., revised. - M.: Energoatomizdat, 1984. - 104 p. Zubarev V.N., Kozlov A.D., Kuznetsov V.M. Thermophysical properties of technically important gases at high temperatures and pressures: Handbook. - M.: Energoatomizdat, 1989. - 232 p. GOST 7.32-91. Research report. GOST 7.1-84. Bibliographic description of the document. Thermal and nuclear power plants: a Handbook / Under the general. ed. V.A. Grigorieva, V.M. Zorin. - 2nd ed., revised. - M.:, 1989. - 608 p. Steam and gas turbines: Textbook for universities / Ed. A.G. Kostyuk, V.V. Frolova. - M.: Energoatomizdat, 1985. - 352 p. Troyanovsky B.M. Variants of the flow part of steam turbines // Electric Stations. - 2003. - No. 2. - S. 18-22. Steam turbine K-160-130 HTGZ / Ed. S.P. Sobolev. - M.: Energy, 1980. - 192 p. Moshkarin A.V., Polezhaev E.V., Polezhaev A.V. Optimal thermal schemes of blocks for supercritical steam pressures: Abstracts of reports of the international scientific and technical. conference. Status and prospects for the development of electrical technology (X Bernard Readings). - Ivanovo: ISPU. - 2001. - T. II. - S. 86. Vikhrev Yu.V. About scientific technical progress in the global thermal power industry. - Power engineer. - 2002. - No. 2. - S. 28-32. Application
Thermal diagram of the turbine K-500-240:
Longitudinal section of the K-500-240 turbine:
STEAM TURBINE UNIT K-500-240-2
POWER 500 MW
Condensing single-shaft steam turbine K-500-240-2 (Fig. 1) without controlled steam extractions, with reheat, rated power of 500 MW, with a rotor speed of 3,000 rpm, is designed to directly drive the TGV-500 alternator. The turbine operates in a block with a boiler, equipped with a regenerative device for heating feed water.
The turbine is designed to operate at the following nominal parameters (Table 1)
The turbine has nine unregulated steam extractions for regenerative heating of feed water to a temperature of 265°C.
Steam extractions from the turbine for regeneration and turbo drives are shown in Table 2.
The exhaust steam flow to the condenser is 965 t/h.
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Consumer |
Parameters in the sampling chamber |
Amount of extracted steam, t/h |
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Pressure, MPa (kgf / cm 2) abs. |
Temperature, °С |
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Deaerator |
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Live steam in front of HPC automatic shut-off valves: |
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pressure, kgf/cm 2 , abs. |
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temperature, °C |
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Steam at the outlet of the HPC at nominal mode: |
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pressure, kgf / cm 2 abs. |
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temperature, С |
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Steam after intermediate overheating in front of the stop valves of the HPC: |
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pressure, kgf / cm 2 abs. |
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temperature, °C |
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The main parameters of the capacitor group: |
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cooling water consumption, m 3 / h |
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cooling water temperature, С |
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design pressure, kgf / cm 2 abs. |
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The main joint venture is fed with steam from the VII selection with a pressure of 0.156 MPa (1.6 kgf / cm 2) in the amount of 22 t / h (maximum 32 t / h) abs.
Two main feed pumps have steam turbine drives, steam for which is taken from the CPC with a pressure in the nominal mode of 1.18 MPa (11.2 kgf / cm 2) abs. and a temperature of 374°C in the amount of 98 t/h.
Long-term operation of the turbine is allowed with deviations from the nominal parameters within the following limits: simultaneous pressure deviation of 23-24 MPa (235-245 kgf / cm 2) abs. and temperatures 530-545°C; steam temperature after intermediate overheating 530-545°С (before the stop valves of the HPC); when the temperature of the cooling water at the inlet to the condensers rises to 33 ° C.
At a fresh steam temperature in front of automatic shut-off valves in the range of 545-550 ° C, as well as a steam temperature after reheating in front of the stop valves of the HPC in the range of 545-550 ° С, the operation of the turbine is allowed for no more than 30 minutes, and the total duration of operation at these temperatures steam should not exceed 200 hours per year.
It is not allowed to operate the turbine for exhaust into the atmosphere and work according to a temporary unfinished scheme.
It is allowed to operate the turbine for a long time at the sliding pressure of live steam in the operating load range from 30 to 100% of the nominal load with fully or partially open control valves of the HPC.
It is not allowed to operate the turbine for a long time at a load below 150,000 kW at the nominal parameters of live steam with deviations not exceeding the limits indicated above.
The turbine unit is equipped with a shaft-turning device that rotates the shaft line at a frequency of 4 rpm, and hydraulic lifting of the rotors.
The turbine is flushed when starting from a cold state with saturated steam supplied to the HPC and HPC, as well as at reduced load without stopping the unit in a certain mode agreed with the plant.
The turbine blade apparatus is designed and configured to operate at a network frequency of 49 to 50.5 Hz. In emergency situations, short-term operation of the turbine is allowed with an increase in frequency to 51 Hz and a decrease to 46 Hz during the time specified in the technical specifications.
It is allowed to start and subsequently load the turbine after a shutdown of any duration. An automated start-up of the turbine is provided for on sliding steam parameters from a cold and warm state.
Turbine condensers are equipped with water and steam receivers. The water intakes are designed to receive 5000 t/h of water at a pressure of 1.9 MPa (20 kgf/cm 2) abs. at a temperature of up to 200°C from the boiler and kindling expanders when starting the turbine. The steam receivers are designed to receive from the BROU with load drops up to 900 t / h of steam at a pressure of up to 0.97 MPa (10 kgf / cm 2) abs. and a temperature of 200 ° C. Reception of steam and water in the condensers stops at a pressure in the condensers above 0.03 MPA (0.3 kgf / cm 2) abs.
The duration of the turbine start-ups from various thermal states (from a push to a nominal load) is approximately equal to: from a cold state - 6-7 hours; after 48-55 hours of inactivity - 3 hours 30 minutes - 4 hours; after 24-32 hours of inactivity - 2 hours; after 6-8 hours of inactivity - 1 hour; after 2-4 hours of inactivity - 30 min.
To reduce the heating time of the turbine and improve start-up conditions, steam heating of the flanges and studs of the HPC and HPC horizontal connector is provided.
Turbine design. The turbine (see Fig. 1) is a single-shaft four-cylinder unit, consisting of a HPC; TsSD and two low-pressure cylinders.
Fresh steam from the boiler is supplied through two pipelines to two check valve boxes installed symmetrically with respect to the longitudinal axis of the turbine.
Each stop valve box is interlocked with two control valve boxes, from which steam is supplied to the HPC through four pipes.
The HPC has an inner casing with nozzle boxes welded into its nozzles. Through the nozzle apparatus, steam enters the HPC, the control stage, and then into nine pressure stages. TsSD single-flow, has 11 steps of pressure. From the exhaust pipes of the TsSD, steam is supplied through four pipes to three low-pressure cylinders.
LPCs are two-stream, five stages in each stream.
The length of the working blade of the last stage is 1050 mm, the average diameter of the impeller of this stage is 2550 mm. The working blades of the last stage have a peripheral shroud. Each LPC is connected to its own capacitor.
The rotors of the HP and CHSD are solid forged, the rotors of the low pressure cylinder are welded and forged. All rotors have rigid couplings and two supports. Each CND has its own fixpoint.
The calculated values of the critical rotational speeds of the turbine shafting with the TGV-500 generator are given below.
The turbine is equipped with steam labyrinth seals. From the extreme compartments of the seals, the vapor-air mixture is sucked off by an ejector through a vacuum cooler.The HPC end seal power circuit allows hot steam to be supplied from an external source when the turbine is started from an uncooled state.
Automatic control system. The turbine is equipped with an automatic control system with hydraulic connections and spoolless protection devices. The uneven regulation of the frequency of rotation of the turbine rotor is 4.5±0.5% of the nominal speed.
On fig. 2 shows the control scheme of the K-500-240-2 turbine.
In the turbine control system, an EGP is provided, which ensures a reduction in overspeed when the generator is disconnected from the network.
The speed controller controls the position of the control valves of the HPC and HPC, it is equipped with a power limiter and a control mechanism.
The control mechanism and power limiter can be operated both manually and remotely using reversible DC motors. The power limiter is equipped with a remote position indicator.
As a working fluid in the control system, condensate is used, which comes from the pressure line of the condensate pumps.
To protect against overclocking, the turbine is equipped with a dual safety regulator, which is activated when the speed reaches 11-12% above the nominal one.
The safety switch actuator causes all stop and control valves to close.
Lubrication system is designed to provide lubrication (synthetic fire-resistant oil OMTI or mineral oil) for bearings of a turbine, a generator and a group of feed pumps.
In the tank with a capacity of 52 m 3 (up to the upper level) are installed: mesh filters for cleaning oil from mechanical impurities; air coolers to improve oil deaeration (the air content behind the air cooler should not exceed 1.5%).
To supply oil to the system, two (one standby) AC electric pumps are provided. Two emergency electric pumps are installed: one is direct current, the other is alternating current.
The oil is cooled in four MB-190-250 type oil coolers (one standby), fed with water from the circulation system. The flow rate of cooling water for each operating oil cooler is 500 m 3 h. The turbine is equipped with two lubrication pressure switches, which provide automatic shutdown of the turbine and barring device in case of pressure drop in the lubrication oil pressure line, as well as switching on the reserve pumps of the lubrication system.
Control and management system turbine provides: control of operation parameters; registration most important parameters; technological, warning and emergency signaling; automatic control of functional groups of technologically connected mechanisms and locking and regulating bodies, duplicated by remote control from the block board; automatic stabilization of a number of parameters, the maintenance of the set values of which requires prompt intervention during normal operation;
automatic protection of the turbine and auxiliary equipment. The unit is controlled centrally and is carried out from the block control room.
The monitoring and control system is carried out on the basis of electrical appliances and equipment.
condensation device consists of two condensers, an air extractor, 1st and 2nd lift condensate pumps, circulation pumps and water filters.
The condenser group includes two condensers with central air suction. Capacitors - single-flow, two-way.
The air-removing device has: two main steam-jet ejectors, a starting steam-jet ejector of the circulation system and a water-jet starting ejector.
The turbine unit is served by two groups of condensate pumps: two condensate pumps of the 1st stage, supplying condensate from the condensers to the desalination plant, and two condensate pumps of the 2nd stage, supplying condensate through regenerative heaters to the deaerator and to the transient control system.
One pump of each group is constantly in operation, the second pump is a reserve one.
Cooling water is supplied to the condenser by circulation pumps.
To break the vacuum, a gate valve DN 150 mm with an electric drive is provided. The gate valve is controlled remotely from the control panel and "by" blocking three operation of the turbine's general unit protections.
Regenerative plant designed for heating feed water with steam taken from the intermediate stages of the turbine, and consists of five HPH, a deaerator and three HPH. The principal thermal diagram of the installation is shown in Fig.3.
The scheme provides for the installation of two feed pumps with condensing turbo drives.
HDPE No. 1, 2, 3, 4 and 5 surface type, vertical, welded construction. HDPE No. 3 and 4 have built-in desuperheaters. The heating steam condensate drain is cascaded, the condensate from LPH No. 5 is drained into LPH No. 4, from there it is supplied by a drain pump to the main condensate line between LPH No. 5 and 4. The condensate from LPH No. 3 is drained into LPH No. condensate between HDPE No. 3 and 2.
LPH No. 4 has one pump, LPH No. 2 has two drain pumps, one of which is a backup.
From LPH No. 1, condensate is discharged through a siphon into the condenser.
For heating after the feed water deaerator, two groups of HPH are installed. Three HPH carry out sequential heating of feed water after the deaerator.
Each HPH is equipped with a cooler of the heating steam of the steam superheater, a control valve for condensate removal from the heater and a level vessel for connecting a level controller sensor with an alarm device.
The HPH group protective device consists of an inlet valve, a check valve, start-up and shutdown pipelines.
Condensate drain from heaters is cascaded.
When the HPH is turned off, long-term operation of the turbine with a capacity of up to 500 MW is allowed.
INTRODUCTION
The development of human society on present stage is inextricably linked with the process of production and use of energy. The most common, clean and cheap is electrical energy. Significant proportion electrical energy produced at thermal and nuclear power stations which provide for the needs of mankind on this stage. Modern energy is based on centralized power generation. The vast majority of generators installed in power plants are driven by steam turbines. Thus, the steam turbine is the main type of engine in a modern thermal power plant, including a nuclear one. Possessing high speed, the steam turbine is small in size and weight and can be built for a large unit power. At the same time, this type of turbine achieves high operating efficiency. This is the main reason for the widespread use of steam turbines in modern power engineering. Its disadvantages include low maneuverability, long start-up and power gain, which is an obstacle to the efficient and economical use of steam turbines to cover the peak part of the electricity consumption schedule.
In this course project, the HPC of the K-500-240-4 LMZ turbine is calculated.
TECHNICAL DESCRIPTION OF THE TURBINE
General information. The K-500-240-4 LMZ condensing steam turbine with a rated power of 525 MW is designed for direct drive of an alternating current generator TVV-500-2EUZ with a power of 500 MW and for operation in a block with a once-through boiler. The nominal parameters of the turbine are presented in table 1.1
Turbine K-500-240-4 LMZ complies with the requirements of GOST 3618-85, GOST 24278-85 and GOST 26948-86.
Table 1.1 - Nominal values of the main parameters of the turbine
|
Index |
|
|
1. Power, MW |
|
|
2. Initial steam parameters: |
|
|
pressure, MPa |
|
|
temperature. °С |
|
|
3. Steam parameters after reheating: |
|
|
pressure, MPa |
|
|
temperature. °С |
|
|
4. Maximum consumption of live steam, t/h |
|
|
5. Water temperature. °С |
|
|
nutritional |
|
|
cooling |
|
|
6. Consumption of cooling water, t/h |
|
|
7. Steam pressure in the condenser. kPa |
Characteristics of turbine selections are given in Table 1.2.
Table 1.2 - Characteristics of turbine extractions
|
Steam consumer |
Steam parameters in the selection chamber |
Amount of extracted steam, t/h |
|
|
Pressure, MPa |
Temperature. °С |
||
|
turbo drive |
|||
|
Deaerator |
|||
* Steam from end seals.
The turbine can operate for a long time with a minimum power of 150 MW at nominal steam parameters. In this case, the time of a gradual transition from the rated power to 30% is at least 60 minutes. In the power range from 100 to 70%, the temperature of live steam and reheat steam should be nominal. With a decrease in power from 70 to 30%, a gradual decrease in temperature from the nominal temperature to 505 °C is possible in at least 60 minutes. The turbine can be operated at sliding live steam pressure. The stable operation of the turbine with a power of less than 30% of the rated power is allowed up to the load for auxiliary needs, as well as operation for auxiliary needs and at idle after load shedding. At the same time, the duration of idling and loading for own needs is not more than 40 minutes. It is allowed to operate the turbine in a steamless mode for up to 3 minutes. Turbine condensers are equipped with water and steam receivers. Water intakes are designed to receive 500 t/h of water at a pressure of 1.96 MPa at a temperature of up to 200 °C from the boiler and kindling expanders when starting the turbine. t/h and temperatures up to 200 °C. The intake of steam and water into the condensers stops when the pressure in the condensers is above 0.029 MPa.
Turbine design. The turbine is a single-shaft four-cylinder unit, consisting of HPC + HPC + 2LPC. Steam from the boiler is supplied through two steam lines to two stop valves. Each of them is interlocked with two control valves, from which steam is supplied through four pipes to the HPC. Four nozzle boxes of nozzles are welded into the inner casing of the HPC. The steam supply fittings have welded joints with the outer casing of the cylinder and movable ones with the necks of the nozzle boxes. After passing the nozzle apparatus, the steam enters the left flow, consisting of a control stage and five pressure stages, turns by 180° and is transferred to the right flow, consisting of six pressure stages, and then is diverted to intermediate superheating through two steam pipelines. After the intermediate overheating, the steam is supplied through two pipes to two stop valves of the TsSD installed on both sides of the cylinder, and from them to four boxes of control valves located directly on the cylinder.
A dual-stream DPC has 11 stages in each stream, with the first stages of each stream placed in a common inner casing. From the exhaust pipes of the LPC, steam is supplied through two pipes to two LPCs.
LPC - two-flow, have five steps in each thread. Steam is admitted into the middle part of the cylinder, consisting of the outer and inner parts. The exhaust pipes of the LPC are welded to the longitudinal condenser.
The HP and SD rotors are solid forged, the LP rotors are with mounted discs, with the height of the last stage blades of 960 mm. The average diameter of this step is 2480 mm. The rotors have rigid couplings and lie on two supports. The shafting fix point (thrust bearing) is located between the HPC and the HPC. The turbine is equipped with steam labyrinth seals. Steam with a pressure of 0.101-0.103 MPa is supplied to the penultimate compartments of the LPC end seals from the collector, the pressure in which is maintained by the regulator equal to 0.107-0.117 MPa. The end seals of HPC and TsSD operate on the principle of self-sealing. The suctions from the penultimate compartments are brought into a common manifold, in which the pressure of 0.118-0.127 MPa is maintained by the regulator “to itself”. From the end fireplace seal chambers of all cylinders, the vapor-air mixture is sucked off by an ejector through a vacuum cooler. The power circuit of HPC and HPC end seals makes it possible to supply hot steam from an external source when starting the turbine from an uncooled state.
The turbine blade apparatus is designed and configured to operate at a mains frequency of 50 Hz, which corresponds to a turbine unit rotor speed of 50 s-1. Long-term operation of the turbine is allowed with frequency deviations in the network of 49.0-50.5 Hz.
It is possible to automatically start the turbine and then load it after a downtime of any duration. It is envisaged to start the turbine on sliding steam parameters from cold and varying degrees of uncooled states. The total number of starts for the entire period of operation from the hot and uncooled states is 750 each.
To reduce the heating time of the turbine and improve start-up conditions, steam heating of the flanges and studs of the HPC and HPC horizontal connector, as well as HPC valve blocks, is provided.
Accessory equipment. The composition of the component equipment of the turbine plant includes:
Steam turbine with automatic control, barring devices, foundation frames, a block of high-pressure stop control valves, a TsSD protective valve box with a valve, turbine casing;
Intra-turbine pipelines;
Tanks of oil and fire-resistant liquid of the control system, oil coolers;
Steam cooler seals; water jet ejectors;
Electrical part of the control system;
Regenerative unit, including HPH No. 1, 2, 3, 4 and 5 surface type, HPH No. 1, 2, 3 surface type with control and safety valves;
PSV installation;
Pumps and electrical equipment of the turbine plant;
Condensing group containing two longitudinal condensers and valves at the outlet of the cooling water.
Table 1.3 - Accessory heat exchange equipment
|
Name |
Designation |
|
|
in the thermal scheme |
size |
|
|
Capacitor |
||
|
Low pressure heaters |
PN-700-29-7-Sh PN-1000-29-7-P PN-1000-29-7-Sh |
|
|
Deaerator |
||
|
High pressure heaters |
PV-2100-380-17 |
|
|
PV-1900-380-44 |
||
|
PV-2100-380-61 |
||
|
Network water heaters |
||
|
Stuffing box heater |
||
|
Ejection heater |
||
|
Oil coolers |
||
|
First lift condensate pump |
||
|
Second lift condensate pump |
||
|
Drainage (drainage) pumps |
||
|
Feed pumps |
Turbine K-500-240-4 LMZ condensing, single-shaft, with 8 unregulated steam extractions, with reheat, rated power 525 MW, rotation speed 3000 rpm. designed for direct drive of alternating current generator TVV-500-2 UZ "Elektrosila" with terminal voltage of 24 kV.
The turbine is designed to operate on the following main parameters:
live steam pressure in front of the stop valves of the HPC - 240 kgf / cm²;
hot steam temperature in front of stop valves - CVP-560°C;
HPC exhaust pressure at rated power 34.9 kgf/cm², maximum pressure - 41.7 kgf/cm²;
steam temperature at HPC exhaust at rated power - 289 o C;
steam pressure in front of stop valves TsSD-32.4 kgf/cm², maximum pressure - 36.6 kgf/cm²;
steam temperature in front of the stop valves of the TsSD after reheating - 560°C;
the design pressure in the turbine condenser is 0.035 kgf/cm² at a cooling water temperature at the condenser inlet of 12 ° C and a flow rate of 73,000 m 3 / h.
principled thermal scheme turbine K - 500 - 240 is shown in Figure 2.1.
The regenerative system of the turbine is designed to heat the main condensate and feed water with steam from the turbine bleeds. The regeneration system consists of four low pressure heaters (two of them are of mixing type), a deaerator and three high pressure heaters. Drainage drain from high pressure heaters (HPH) - cascade (without the use of drainage pumps) to the deaerator; from low pressure heaters (LPH) - in cascade in LPH - 2.
Steam from the intermediate seals enters the stuffing box cooler (SH), and from the end seals into the stuffing box heater (PS), which contributes to additional heating of the main condensate. To compensate for condensate losses, the condensate collector is fed with chemically treated water from the CWT.
In this scheme, a feed turbopump (FPU) is installed, which is driven by a turbine. The steam for the turbo drive comes from the third turbine extraction.
Turbine K-500-240 is five-cylinder (one high-pressure, one medium and three low-pressure cylinders).
2. Calculation of the basic thermal scheme of a steam turbine plant
2.1 Initial data for calculating the basic thermal diagram of the k-800-240 turbine plant
Electric power ;
Fresh steam pressure, P 0 =23.5 MPa;
Live steam temperature, t 0 = 560°С;
HPC exhaust pressure, R HPC = 3.49 MPa;
Steam pressure in front of the stop valves of the TsSD after intermediate overheating R PP = 3.24 MPa;
The temperature of the steam in front of the stop valves of the TsSD after intermediate overheating, t PP =560°C;
The pressure in the turbine condenser R k =0.0034 MPa at a cooling water temperature at the condenser inlet of 12°C and a flow rate of 73,000 m 3 /h.
Table 1. Efficiency values of thermal circuit elements
|
Name |
Meaning |
|
Efficiency of regenerative high-pressure heaters (HRH) |
|
|
Efficiency of regenerative low pressure heaters (LPH) |
|
|
Feed pump efficiency |
|
|
Feed water deaerator efficiency |
|
|
Generator efficiency - electromechanical |
|
|
pipeline efficiency |
|
|
Internal relative efficiency of the turbine by compartments |
|
;
;
.Figure 1. Principal thermal diagram of the K-800-240 turbine plant
APPROVED by Chief technical management for the operation of power systems 02.07.85
Deputy Head D.Ya. SHAMARAKOV
|
Name |
Sample chart |
By steam consumption |
By heat consumption |
|||||
|
Unit |
Meaning |
Unit |
Meaning |
|||||
|
1.1. Idle hourly consumption |
||||||||
|
1.2. Additional specific consumption (increase) |
t/(MW h) |
Gcal/(MWh) |
||||||
|
1.3. Feature conditions: |
||||||||
|
a) pressure of live steam and steam in steps |
Rice. 6, 7a, 7b |
MPa (kgf / s m 2) |
MPa (kgf / cm 2) |
|||||
|
b) the degree of dryness of fresh steam |
||||||||
|
kPa (kgf / cm 2) |
kPa (kgf / cm 2) |
|||||||
|
g) feed water consumption |
G a.c. = D0- 40 t/h |
G a.c. = D0- 40 t/h |
||||||
|
2. Characteristic at constant flow rate and temperature of cooling water (for K-10120 KhTGZ condenser): W = 4? 20720 = 82880 t/h; tV 1 nom= 12 °C and the parameters of item 1.3 |
||||||||
|
2.1. Idle hourly consumption |
||||||||
|
2.2. Additional specific consumption (increase) |
t/(MW h) |
Gcal/(MWh) |
||||||
|
table 2 |
SUMMARY OF NORMS OF TECHNICAL AND ECONOMIC INDICATORS |
K-500-240-2 HTGZ |
||||||
|
Name |
Sample chart |
By steam consumption |
By heat consumption |
|||||||||
|
Unit |
Before the break |
After the break |
Unit |
Before the break |
After the break |
|||||||
|
1. Characteristic at constant pressure (vacuum) in the condenser |
||||||||||||
|
1.1. Additional specific consumption (increase) |
kg/(kWh) |
Gcal/(MWh) |
||||||||||
|
1.2. Kink characteristic |
||||||||||||
|
1.3. Feature conditions: |
||||||||||||
|
a) live steam pressure and stages |
MPa (kgf / cm 2) |
MPa (kgf / cm 2) |
||||||||||
|
b) fresh steam temperature |
||||||||||||
|
c) steam temperature after reheating |
||||||||||||
|
d) pressure loss in the reheat path |
% R 1 TsSD |
% R 1 TsSD |
||||||||||
|
e) exhaust steam pressure |
kPa (kgf / cm 2) |
kPa (kgf / cm 2) |
||||||||||
|
f) temperature of feed water and main condensate |
||||||||||||
|
g) feed water consumption |
G a.c. = D0 |
G a.c. = D0 |
||||||||||
|
2. Characteristic at a constant flow rate and temperature of the cooling water (for the K-11520-2KhTGZ condenser W = 51480 t/h; tV1nom= 12 °С and the parameters of item 1.3 (a, b, c, d, f, g) |
||||||||||||
|
2.1. Additional specific consumption (increase) |
kg/(kWh) |
Gcal/(MWh) |
||||||||||
|
2.2. Kink characteristic |
||||||||||||
|
3. Corrections to specific heat consumption for deviation of parameters from nominal values, %: |
||||||||||||
|
by ± 1 MPa (10 kgf / cm 2) fresh steam |
||||||||||||
|
at ±10 °C fresh steam |
||||||||||||
|
at ±10 °C reheat steam temperature |
||||||||||||
|
to the change in pressure loss in the reheat path |
||||||||||||
|
to the pressure change in the condenser |
||||||||||||
|
Table 3 |
TYPICAL NET ENERGY CHARACTERISTICS OF A TURBO UNIT |
K-500-240-2 HTGZ |
|||||
|
TERMS OF CHARACTERISTICS: 1. Parameters and thermal scheme - fig. 1 2. Pressure of circulation pumps - 120 kPa (12 m water column) |
|||||||
|
Power at generator outputs, MW |
|||||||
|
Internal power of the feed pump turbo drive, MW |
|||||||
|
Power spent for auxiliary needs of the turbine unit, MW |
|||||||
|
including circulation pumps |
|||||||
|
Gross heat consumption of a turbine unit, Gcal/h |
|||||||
|
Turbine net power, MW |
|||||||
|
Heat consumption for own needs, Gcal/h |
|||||||
|
Heat consumption for electricity generation, including heat consumption for own needs, Gcal/h |
|||||||
|
Heat consumption equation for net power, |
|||||||
|
Corrections (%) to the total and specific net heat consumption for changes in the pressure of circulation pumps |
|||||||
|
Pump pressure, kPa (m water column) |
Net power, MW |
||||
|
Table 4 |
TYPICAL ENERGY CHARACTERISTICS OF A TURBO UNIT |
Type K-500-240-2 HTGZ |
|||||||||||||||
|
Basic factory data of the turbine unit |
|||||||||||||||||
|
D pp t/h |
P 0 kPa (kgf / cm 2) |
Surface of two capacitors, m 2 |
|||||||||||||||
|
Comparison of test results with warranty data (at rated P 0 , t 0 , , , W, F) |
|||||||||||||||||
|
Index |
|||||||||||||||||
|
Fresh steam consumption |
under warranty |
||||||||||||||||
|
on tests |
|||||||||||||||||
|
Feed water temperature |
under warranty |
||||||||||||||||
|
on tests |
|||||||||||||||||
|
Pressure loss in the reheat path |
under warranty |
||||||||||||||||
|
on tests |
|||||||||||||||||
|
Internal relative efficiency of the turbo drive of the feed pump |
under warranty |
||||||||||||||||
|
on tests |
|||||||||||||||||
|
Specific heat consumption |
kcal/(kW h) |
under warranty |
|||||||||||||||
|
on tests |
|||||||||||||||||
|
Specific heat consumption, reduced to warranty conditions |
kcal/(kW h) |
||||||||||||||||
|
Deviation of the specific heat consumption from the guarantee |
kcal/(kW h) |
||||||||||||||||
|
TYPICAL ENERGY CHARACTERISTICS OF A TURBO UNIT PRINCIPAL THERMAL DIAGRAM |
K-500-240-2 HTGZ |
|
TYPICAL ENERGY CHARACTERISTICS OF A TURBO UNIT STEAM AND HEAT CONSUMPTION |
K-500-240-2 htgz |
||||||||||||||||||
|
Specification conditions |
|||||||||||||||||||
|
P 0 MPa (kgf / cm 2) |
D Ppp |
P 2 kPa (kgf / cm 2) |
D NSWEAT MW |
Ga.s. = D 0 |
Gvpr = 0 |
ta.s. |
tOK |
Generator |
thermal scheme |
||||||||||
|
MPa (kgf / cm 2) |
|||||||||||||||||||
|
TYPICAL ENERGY CHARACTERISTICS OF A TURBO UNIT STEAM AND HEAT CONSUMPTION |
K-500-240-2 HTGZ |
|||||||||||||||
|
Specification conditions |
||||||||||||||||
|
P 0 MPa (kgf / cm 2) |
D Ppp |
P 2 MPa (kgf / cm 2) |
D NSWEAT MW |
G a.c. = D 0 |
G vpr = 0 |
Generator |
thermal scheme |
|||||||||
|
MPa (kgf / cm 2) |
||||||||||||||||
|
TYPICAL ENERGY CHARACTERISTICS OF A TURBO UNIT CHP STEAM DISTRIBUTION DIAGRAM |
K-500-240-2 htgz |
|
TYPICAL ENERGY CHARACTERISTICS OF A TURBO UNIT PRESSURE IN THE SELECTIONS, AFTER THE HPC, BEFORE THE STOP VALVES OF THE HPC |
K-500-240-2 HTGZ |
|
TYPICAL ENERGY CHARACTERISTICS OF A TURBO UNIT SELECTION PRESSURE |
K-500-240-2 HTGZ |
|
TYPICAL ENERGY CHARACTERISTICS OF A TURBO UNIT SELECTION PRESSURE |
K-500-240-2 HTGZ |
|
TYPICAL ENERGY CHARACTERISTICS OF A TURBO UNIT TEMPERATURE AND ENTHALPY OF FEED WATER |
K-500-240-2 HTGZ |
|
TYPICAL ENERGY CHARACTERISTICS OF A TURBO UNIT MAIN CONDENSATE TEMPERATURE |
K-500-240-2 HTGZ |
|
TYPICAL ENERGY CHARACTERISTICS OF A TURBO UNIT INTERNAL RELATIVE EFFICIENCY OF HPC AND CPC |
K-500-240-2 htgz |
|
TYPICAL ENERGY CHARACTERISTICS OF A TURBO UNIT INTERNAL POWER OF THE TURBODRIVE AND STEAM CONSUMPTION ON THE STD |
K-500-240-2 HTGZ |
|
TYPICAL ENERGY CHARACTERISTICS OF A TURBO UNIT INTERNAL RELATIVE EFFECTIVENESS, TURBO CONDENSER STEAM PRESSURE AND FEED PUMP DISCHARGE PRESSURE |
K-500-240-2 HTGZ |
|
TYPICAL ENERGY CHARACTERISTICS OF A TURBO UNIT GROWTH OF ENTHALPY OF FEED WATER IN THE FEED PUMP |
K-500-240-2 HTGZ |
|
TYPICAL ENERGY CHARACTERISTICS OF A TURBO UNIT PRESSURE LOSS IN THE REHEAT PATH |
K-500-240-2 htgz |
|
TYPICAL ENERGY CHARACTERISTICS OF A TURBO UNIT ENTHALPIES OF FRESH STEAM, STEAM BEFORE STOP VALVES OF HPC AND AFTER HPC |
K-500-240-2 HTGZ |
|
TYPICAL ENERGY CHARACTERISTICS OF A TURBO UNIT STEAM CONSUMPTION TO INTERSUPERHEAT, TO THE CONDENSER |
K-500-240-2 htgz |
|
TYPICAL ENERGY CHARACTERISTICS OF A TURBO UNIT STEAM CONSUMPTION FOR HPH |
K-500-240-2 HTGZ |
|
TYPICAL ENERGY CHARACTERISTICS OF A TURBO UNIT STEAM CONSUMPTION PER DEAERATOR |
K-500-240-2 HTGZ |
|
TYPICAL ENERGY CHARACTERISTICS OF A TURBO UNIT STEAM CONSUMPTION FOR HDPE |
K-500-240-2 HTGZ |
|
TYPICAL ENERGY CHARACTERISTICS OF A TURBO UNIT TEMPERATURE DRIVES OF LDPE |
K-500-240-2 HTGZ |
|
TYPICAL ENERGY CHARACTERISTICS OF A TURBO UNIT TEMPERATURE DRIVES HDPE No. 3, 4, 5 |
K-500-240-2 HTGZ |
|
TYPICAL ENERGY CHARACTERISTICS OF A TURBO UNIT TEMPERATURE DRIVES HDPE No. 1, 2 |
K-500-240-2 htgz |
|
TYPICAL ENERGY CHARACTERISTICS OF A TURBO UNIT ELECTROMECHANICAL EFFICIENCY OF THE TURBO UNIT, MECHANICAL LOSS AND GENERATOR |
K-500-240-2 HTGZ |
|
TYPICAL ENERGY CHARACTERISTICS OF A TURBO UNIT |
K-500-240-2 HTGZ |
|
TYPICAL ENERGY CHARACTERISTICS OF A TURBO UNIT CHARACTERISTICS OF THE CAPACITOR K-11520-2 HTGZ |
K-500-240-2 HTGZ |
|
TYPICAL ENERGY CHARACTERISTICS OF A TURBO UNIT CHARACTERISTICS OF THE CAPACITOR K-11520-2 HTGZ |
K-500-240-2 HTGZ |
|
TYPICAL ENERGY CHARACTERISTICS OF A TURBO UNIT CORRECTION TO THE OUTPUT STEAM PRESSURE |
K-500-240-2 HTGZ |
|
TYPICAL ENERGY CHARACTERISTICS OF A TURBO UNIT CORRECTION TO THE POWER OF ONE PTN FOR CHANGE OF PRESSURE IN THE CONDENSER OF THE OK-18PU DRIVE TURBINE |
K-500-240-2 HTGZ |
|
Rice. 27, f, h |
TYPICAL ENERGY CHARACTERISTICS OF A TURBO UNIT |
K-500-240-2 HTGZ |
h) to turn off the HPH group
|
Rice. 27, and, to |
TYPICAL ENERGY CHARACTERISTICS OF A TURBO UNIT CORRECTIONS FOR FRESH STEAM FLOW |
K-500-240-2 HTGZ |
|
Rice. 27, n, o, p |
TYPICAL ENERGY CHARACTERISTICS OF A TURBO UNIT CORRECTIONS FOR FRESH STEAM FLOW |
K-500-240-2 HTGZ |
p) to turn off drainage pump DN #2
|
Rice. 27, p, s |
TYPICAL ENERGY CHARACTERISTICS OF A TURBO UNIT CORRECTIONS FOR FRESH STEAM FLOW |
K-500-240-2 htgz |
1 - bypass all HDPE; 2 - bypassing LPH No. 1, LPH No. 2 and LPH No. 3; 3 - bypass LPH No. 4, LPH No. 5
|
Rice. 27, t, y |
TYPICAL ENERGY CHARACTERISTICS OF A TURBO UNIT CORRECTIONS FOR FRESH STEAM FLOW |
K-500-240-2 HTGZ |
|
Rice. 27, f, x, c |
TYPICAL ENERGY CHARACTERISTICS OF A TURBO UNIT CORRECTION FOR FRESH STEAM FLOW |
K-500-240-2 HTGZ |
t) to turn on the network water heaters (the condensate of the extracted steam is returned to the line of the main condensate behind LPH No. 1)
|
Rice. 27, h, sh |
TYPICAL ENERGY CHARACTERISTICS OF A TURBO UNIT CORRECTIONS FOR FRESH STEAM FLOW |
K-500-240-2 htgz |
h) to change the relative pressure loss in the heating steam pipelines to the HPH
|
TYPICAL ENERGY CHARACTERISTICS OF A TURBO UNIT CORRECTIONS FOR FRESH STEAM FLOW |
K-500-240-2 HTGZ |
|
Rice. 28, a, b |
TYPICAL ENERGY CHARACTERISTICS OF A TURBO UNIT |
K-500-240-2 HTGZ |
a) on the deviation of the pressure of live steam from the nominal
b) on the deviation of the temperature of live steam from the nominal
|
Rice. 28, c, d |
TYPICAL ENERGY CHARACTERISTICS OF A TURBO UNIT AMENDMENTS TO TOTAL AND SPECIFIC HEAT CONSUMPTION |
K-500-240-2 htgz |
c) the deviation of the reheat steam temperature from the nominal
d) to change in pressure loss in the reheating path
|
Rice. 28, e, f |
TYPICAL ENERGY CHARACTERISTICS OF A TURBO UNIT AMENDMENTS TO TOTAL AND SPECIFIC HEAT CONSUMPTION |
K-500-240-2 HTGZ |
e) to change the water heating in the feed turbopump
f) deviation of feed water heating in HPH
|
Rice. 28, f, h |
TYPICAL ENERGY CHARACTERISTICS OF A TURBO UNIT AMENDMENTS TO TOTAL AND SPECIFIC HEAT CONSUMPTION |
K-500-240-2 HTGZ |
g) to the deviation of the heating of the main condensate in the HDPE
h) to turn off the HPH group
|
Rice. 28, and, to |
TYPICAL ENERGY CHARACTERISTICS OF A TURBO UNIT AMENDMENTS TO TOTAL AND SPECIFIC HEAT CONSUMPTION |
K-500-240-2 HTGZ |
i) to transfer the deaerator supply from IV to III selection
j) to increase the consumption of steam IV extraction on the PTN
k) deviation of the temperature of the cooling water at the inlet to the turbine condenser from the nominal
m) for the deviation of the pressure of the exhaust steam in the turbine condenser from the nominal
|
Rice. 28, n, o, p |
TYPICAL ENERGY CHARACTERISTICS OF A TURBO UNIT AMENDMENTS TO TOTAL AND SPECIFIC HEAT CONSUMPTION |
K-500-240-2 htgz |
m) to change the relative flow rate for injection into the intermediate superheater of the boiler
o) to turn off LPH No. 4 and LPH No. 5
p) to turn off the drainage pump DN No. 1
|
Rice. 28, p, s |
TYPICAL ENERGY CHARACTERISTICS OF A TURBO UNIT AMENDMENTS TO TOTAL AND SPECIFIC HEAT CONSUMPTION |
K-500-240-2 HTGZ |
p) for bypassing with the main condensate of HDPE
1 - bypass all HDPE; 2 - bypassing LPH No. 1, LPH No. 2 and LPH No. 3; 3 - bypass LPH No. 4, LPH No. 5
c) to turn off the drainage pumps DN No. 1, DN No. 2
|
Rice. 28, t, y |
TYPICAL ENERGY CHARACTERISTICS OF A TURBO UNIT AMENDMENTS TO TOTAL AND SPECIFIC HEAT CONSUMPTION |
K-500-240-2 htgz |
r) for the release of steam from the extractions in excess of the needs of regeneration (return of the condensate of the extracted steam to the condenser)
s) to turn off the drainage pump DN No. 2
|
Rice. 28, f, x, c |
TYPICAL ENERGY CHARACTERISTICS OF A TURBO UNIT AMENDMENTS TO TOTAL AND SPECIFIC HEAT CONSUMPTION |
K-500-240-2 HTGZ |
f) to turn on the network water heaters (the condensate of the extracted steam is returned to the main condensate line)
x) when operating at sliding pressure of live steam (regulating valves I - VIII are open)
v) when operating at sliding pressure of live steam (I - V control valves are open)
|
Rice. 28, h, sh |
TYPICAL ENERGY CHARACTERISTICS OF A TURBO UNIT AMENDMENTS TO TOTAL AND SPECIFIC HEAT CONSUMPTION |
K-500-240-2 htgz |
h) to change in relative pressure losses (? R/R) in pipelines of heating steam to HPH
w) to change the relative pressure loss in the heating steam pipelines to the HDPE
|
TYPICAL ENERGY CHARACTERISTICS OF A TURBO UNIT AMENDMENTS TO TOTAL AND SPECIFIC HEAT CONSUMPTION |
K-500-240-2 HTGZ |
w) to change the efficiency of HPC, CSD, LPC
Application
1. CONDITIONS FOR COMPILING THE ENERGY CHARACTERISTICS
The typical energy characteristic of the K-500-240-2 KhTGZ turbine unit was compiled on the basis of thermal tests of two turbines carried out by Uraltekhenergo at Troitskaya and Reftinskaya GRES. The characteristic reflects the technically achievable efficiency of the turbine unit operating according to the factory design thermal scheme (Fig. 1) and under the following conditions taken as nominal:
Fresh steam pressure in front of HPC stop valves - 24 MPa (240 kgf/cm);
Fresh steam temperature in front of HPC stop valves - 540 °C;
Steam temperature after reheating before stop valves of TsSD - 540 °C;
The pressure loss in the reheating path in the section from the HPC exhaust to the stop valves of the HPC in relation to the pressure in front of the stop valves of the HPC is 9.9% (Fig. 14);
Exhaust steam pressure: for characteristics at a constant steam pressure in the condenser - 3.5 kPa (0.035 kgf / cm 2); for characteristics at constant flow rate and temperature of the cooling water - in accordance with the thermal characteristic of the K-11520-2 condenser at W = 51480 t/h and t 1 V= 12 °C (Fig. 24, a);
The total internal power of the PTH turbo drive and the pressure of the feed water on the discharge side - in accordance with fig. 11, 12;
The increase in the enthalpy of feed water in the feed pump - according to fig. 13;
There is no injection into the reheater;
Steam for turbine seals and ejectors is supplied from the deaerator in the amount of 11.0 t/h;
The high and low pressure regeneration system is fully turned on, the 0.7 MPa deaerator (7 kgf / cm 2) is supplied with steam II, IV turbine extractions (depending on the load);
The feed water flow rate is equal to the live steam flow rate;
The temperature of the feed water and the main condensate corresponds to the dependences shown in Fig. 8, 9;
The steam of unregulated turbine extractions is used only for the needs of regeneration, feeding the feed turbopumps; general station heat consumers are switched off;
The electromechanical losses of the turbine unit are taken according to the calculations of the plant (Fig. 23);
Nominal cosj= 0,85.
The test data underlying this characteristic were processed using the tables “Thermophysical properties of water and steam” (M .: Publishing House of Standards, 1969).
2. CHARACTERISTICS OF THE EQUIPMENT INCLUDED IN THE TURBO PLANT
In addition to the turbine, the turbine plant includes the following equipment:
TGV-500 generator of the Electrotyazhmash plant;
Three high pressure heaters - PVD No. 7 - 9, respectively, types PV-2300-380-17, PV-2300-380-44, PV-2300-380-61, the desuperheaters of which are connected according to the Ricard-Nekolny scheme;
Deaerator 0.7 MPa (7 kgf / cm 2);
Five low pressure heaters:
PND No. 4.5 type PN-900-27-7;
PND No. 1, 2, 3 type PN-800-29-7;
Two surface double-flow condensers K-11520-2;
Two main steam jet ejectors EP-3-50/150;
One EU-16-1 seal ejector;
Two feed turbopump units (PTN), each of which consists of a feed pump PTN-950-350 LMZ, a drive turbine OK-18 PU of the Kaluga Turbine Plant; upstream (booster) pumps are located on the same shaft as the feed pump (both PV pumps are constantly in operation);
Two condensate pumps of the 1st stage KSV-1600-90 driven by an AV-500-1000 electric motor (one pump is constantly in operation, one is in reserve);
Two condensate pumps of the second stage TsN-1600-220 driven by an electric motor AV-1250-6000 (one pump is constantly in operation, one is in reserve);
Two drain pumps PND No. 2 KSV-200-210 driven by an AB-113-4 electric motor;
One drain pump PND No. 4 6N-7? 2a driven by an MAZb-41/2 electric motor.
3. CHARACTERISTICS OF THE GROSS TURBO UNIT
The total gross heat consumption and live steam consumption depending on the power at the generator outputs are analytically expressed by the following equations:
at constant vapor pressure in the condenser:
R 2 \u003d 3.5 kPa (0.035 kgf / cm 2) (see Fig. 3)
Q 0 = 86,11 + 1,7309N T+ 0.1514 ( N T- 457.1) Gcal/h;
D 0 = -6,37 + 2,9866N T+ 0.6105 ( N T- 457.1) t/h;
at constant flow ( W= 51480 t/h) and temperature ( t 1 V= 12 °C) cooling water (Fig. 2):
Q 0 = 67,46 + 1,7695NT+ 0.1638 ( NT- 457.5) Gcal/h;
D 0 = -37,05 + 3,0493N T+ 0.6469 ( N T- 457.5) t/h.
The characteristic is valid when working with the generator's own exciter. When working with a standby exciter, the gross power of the turbine set is determined as the difference between the power at the generator outputs and the power consumed by the standby exciter.
4. AMENDMENTS FOR OPERATING DEVIATIONS
The consumption of steam and heat for the power specified in the operating conditions is determined by the corresponding dependences of the characteristic with the subsequent introduction of the necessary corrections (Fig. 27, 28). These corrections take into account the difference between operating conditions and characteristic conditions. The corrections are given at constant power at the generator outputs. The sign of the corrections corresponds to the transition from the characteristics to operational conditions. If there are two or more deviations from the nominal values in the operating conditions of the turbine unit, the corrections are algebraically summed up.
The use of correction curves is illustrated by the following example.
NT= 500 MW;
P 0 \u003d 24.3 MPa (243 kgf / cm 2);
W=51480 t/h;
the drainage of LPH No. 4 is cascaded into LPH No. 3.
The rest of the parameters are nominal.
Determine the consumption of fresh steam, total and specific heat consumption under given conditions. The calculation results are summarized in the table below.
|
Index |
Designation |
Unit |
Definition method |
Received value |
|
Heat consumption for the turbine set under nominal conditions |
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|
Live steam consumption at nominal conditions |
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Specific heat consumption under nominal conditions Parameters and thermal diagram of the installation - according to fig. 1; The pressure developed by the circulation pumps is 120 kPa (12 m of water column); Consumption of circulating water through the turbine condenser - 51480 t/h; Efficiency of the circulation pump - 85.2%; Heat consumption for auxiliary needs of the turbine unit is 0.96 Gcal/h (0.1% of heat consumption by the turbine unit at rated power); Electricity consumption for own needs of the turbine unit takes into account the operation of pumps (circulation, condensate, drain LPH, turbine control system); Electricity consumption for other mechanisms is assumed to be 0.3% of the rated power of the turbine unit. When determining the net power from the power at the generator outputs ( N T) the power spent for the auxiliary needs of the turbine unit is subtracted:
If the pressure developed by the circulation pumps deviates from the nominal one (120 kPa = 12 m of water column), a correction is introduced to the net heat consumption, determined by the equation for a given net power. The use of the net characteristic and corrections to the net heat consumption for the change in pressure developed by the circulation pumps is illustrated by the following example.
N c.n\u003d 100 kPa (10 m water column). Determine the net heat consumption. 1. According to the net characteristic equation, the net heat consumption is determined at N c.n= 120 kPa (12 m w.c.)
2. An amendment to the net heat consumption is determined
3. The desired net heat consumption at N c.n= 100 kPa (10 m w.c.) and
The normative graphic dependences are valid in the ranges shown on the corresponding graphs of this Typical energy characteristic. Note. To transfer from the MKGSS system to the SI system, it is necessary to use the conversion factors: 1 kgf / cm 2 = 98066.5 Pa; 1 mm w.c. Art. = 9.81 Pa; 1 cal = 4.1868 J; 1 kcal/kg = 4.1868 kJ/kg; 1 kWh = 3.6 MJ. |
is defined as follows:
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