CN107543733A - A kind of condenser duty on-line monitoring system and measuring method - Google Patents

Abstract

The invention relates to an online monitoring system and measurement method for condenser heat load. The system includes an online data collection module, a data preprocessing module, a performance test calibration module and a data calculation and analysis module. The flow-based ASME performance test calibrates the main steam volume flow corresponding to different valve positions. Based on this test data, calculate the main steam flow, main feedwater flow, and reheat steam flow of the thermal system with the help of other auxiliary measurement data such as pressure and temperature. and other parameters, and then obtain the total energy entering the steam turbine system; according to the law of conservation of system energy, the heat load of the condenser is obtained after deducting the generator power and various losses from the total energy entering the steam turbine system, so that the final heat load The data accuracy is high and the real-time performance is good.

Description

An on-line monitoring system and measurement method for condenser heat load

technical field

The invention relates to an on-line monitoring system and a measuring method for a heat load of a condenser, belonging to the technical field of thermal power generation.

Background technique

As the country attaches great importance to the energy saving and emission reduction work of thermal power units, real-time online monitoring of the heat load of steam turbine condenser is of great significance to the energy saving and emission reduction work of thermal power generation enterprises.

At present, there are generally two ways to obtain the heat load of the condenser: one is to calculate the steam flow rate and steam enthalpy value entering the condenser, the condensate flow rate and condensate enthalpy value, the drain flow rate and The heat load of the condenser can be solved directly by using the enthalpy value of the water trap; another method is to calculate the heat load of the condenser by measuring the flow rate of the circulating cooling water flowing through the condenser and the temperature of the circulating cooling water entering and leaving the condenser.

The above-mentioned first method needs to calculate the exhaust enthalpy of the low-pressure cylinder through the energy balance of the whole machine, which involves many test parameters and test instruments, so the accuracy is difficult to guarantee.

The above second method requires accurate measurement of the circulating cooling water flow rate and the temperature of the circulating water entering and leaving the condenser. However, the circulating cooling water pipes of 300MW and above units have a diameter of 2m-3m, which cannot be measured with high-precision flow nozzles or orifice plates, and the measurement accuracy of ultrasonic flowmeters is poor; secondly, the temperature rise of circulating cooling water is generally not high. If it exceeds 10°C, even a small temperature measurement error will bring a large error to the calculation of the heat load of the condenser.

The heat load calculation method of the condenser described in patent 201510007306.4 uses the relationship curve between the heat consumption rate and the load to reversely correct the operating parameters to obtain the heat consumption rate of the steam turbine, and then obtain the corresponding heat load of the condenser. The heat consumption rate and load relationship curve based on this method can only reflect the heat consumption of the steam turbine in the isolation state of the unit test, but the units are not in the isolation state in actual operation, and most units have external steam extraction, boiler soot blowing and sewage discharge, etc. , so the calculation accuracy of this method is greatly affected by the state of the system.

Contents of the invention

In order to solve the problems existing in the prior art, the present invention provides an accurate real-time online monitoring system and method for the heat load of the condenser.

In order to achieve the above object, the technical solution proposed by the present invention is: an online monitoring system for condenser thermal load, which is used to monitor the thermal load of the condenser in thermal power generating units on-line, the system includes an online data collection module, data preprocessing module, a performance test calibration module and a data calculation and analysis module, the online data collection module is connected to the data preprocessing module, the data preprocessing module is connected to the performance test calibration module, the performance test calibration module is connected to the data calculation and analysis module, and the The online data collection module includes several pressure and temperature sensors, the electric power meter at the generator outlet of the unit, and the flow sensor on the heating and extraction pipeline. Several pressure and temperature sensors are respectively installed in the main steam pipeline and the reheat steam pipeline. pipeline, heating extraction steam pipeline, heating extraction steam return water pipeline, final water supply pipeline, cold resteam pipeline, reheat desuperheating water pipeline, inlet and outlet of reheat desuperheater, and inlet and outlet of high pressure heater At the water outlet, water outlet, steam inlet and drain port; there are three high-pressure heaters in the thermal power generation unit, which are respectively the first high-pressure heater, the second high-pressure heater and the third high-pressure heater. The online data The collection module is used to collect online data, the data preprocessing module is used to preprocess online data, and the performance test calibration module is used to store benchmark data calibrated by high-precision ASME tests and receive preprocessed data , and obtain benchmark data such as the main steam volume flow rate according to the preprocessed data, and the data calculation and analysis module is used to calculate and analyze the online data and the benchmark data to obtain the heat load of the steam turbine condenser.

The improvement to the above technical solution is: the data calculation and analysis module includes a data conversion module and a data calculation module, and the data conversion module is used to convert the pressure and temperature data collected by the pressure and temperature sensors into Data such as density and enthalpy.

The improvement to the above technical solution is: further comprising a terminal display module connected to the data calculation and analysis module for receiving and displaying the heat load data of the condenser.

A method for online measurement of condenser heat load using the above-mentioned condenser heat load online monitoring system, comprising the following steps:

Step 1. Collect online data such as the pressure and temperature of steam and water in each pipeline in the thermal power generation unit through pressure and temperature sensors, and collect online data such as generator power and heating and extraction volume in the DCS system of the thermal power generation unit;

Step 2. Calculate the required benchmark data through ASME test calibration;

Step 3, using the water and steam property calculation software package to calculate the density and enthalpy data of steam and water according to the pressure and temperature data collected in step 1;

Step 4, calculate the mass flow rate of steam and water in each pipeline in the thermal power generating set;

Step 5, calculate the heat obtained by the steam turbine system in the thermal power generating set,

Q ₀ ＝F _m h _m +F _r h _r -F _w h _w -F _cr h _cr -F _rhs h _rhs -F _cq (h _cq -h _hs )+3600(W _f +W _n )η _T (9 )

In the formula: Q ₀ is the heat obtained by the steam turbine system, F _m is the main steam flow rate, h _m is the main steam enthalpy value, F _r is the reheat steam flow rate, h _r is the reheat steam enthalpy value, F _w is the final feed water flow rate , h _w is the final feed water enthalpy value, F _cr is the cold resteam flow rate, h _cr is the cold resteam enthalpy value, F _rhs is the reheat desuperheating water flow rate, h _rhs is the reheat desuperheating water enthalpy value, F _cq is the heating Extraction steam flow, h _cq is heating extraction steam enthalpy, h _hs is heating extraction steam return enthalpy, W _f is feed water pump motor power, kW; W _n is condensing pump motor power, η _T is work heat conversion efficiency;

Step 6, calculating the heat load of the condenser;

Calculate the heat load of the condenser according to the principle of system energy conservation;

Where: Q _n is the heat load of the condenser, W _c is the power of the generator, η _g is the efficiency of the generator, and η _m is the mechanical efficiency.

The improvement to above-mentioned technical scheme is: the content of ASME test in the described step 2 is:

①Through the high-precision thermal performance test to test the main steam volume flow rate corresponding to the comprehensive valve position of different steam turbines,

② Test the bridge leakage D _g at the junction of the high-pressure cylinder and the medium-pressure cylinder through the variable steam temperature test.

The improvement to the above technical solution is: the mass flow calculated in step 4 includes the main steam mass flow, the final feed water flow, the cold resteam flow, the reheated desuperheating water amount and the reheated steam flow.

The improvement to the above technical solution is: the calculation method of the main steam mass flow rate is:

①Collect the steam turbine integrated valve position value ψ _i , and obtain the main steam volume flow Q _i corresponding to the current integrated valve position value ψ _i according to the benchmark data in step 2;

②Collect the main steam pressure value P _m and the main steam temperature value t _m , and calculate the main steam density ρ _m through the water and steam property calculation software package;

③ Calculate the main steam mass flow rate F _m by using the main steam volume flow rate Q _i and the main steam density ρ _m ;

The calculation method of the final feed water flow is:

F _w =F _m +D ₀

In the above formula: D ₀ is the discharge volume of steam and water on the furnace side.

The improvement to the above technical solution is: the calculation method of the cold resteam flow is:

① Collect the inlet water pressure P _1j , inlet water temperature t _1j , outlet water pressure P _1c , outlet water temperature t _1c , inlet steam pressure P ₁ , inlet steam temperature t ₁ , drain pressure P _s1 , drain temperature t of the first high pressure heater _s1 and other parameters;

Calculate the inlet water enthalpy value h _1j , the outlet water enthalpy value h _1c , the inlet steam enthalpy value h ₁ , and the drain enthalpy value h _s1 of the high pressure heater through the water and steam property calculation software package, and calculate the extraction flow F ₁ ;

② Collect the second highest water inlet pressure P _2j , inlet water temperature t _2j , outlet water pressure P _2c , outlet water temperature t _2c , inlet steam pressure P ₂ , inlet steam temperature t ₂ , drain pressure P _s2 , drain temperature t _s2 , etc. parameter;

Calculate #2 high inlet water enthalpy value h _2j , outlet water enthalpy value h _2c , inlet steam enthalpy value h ₂ , and hydrophobic enthalpy value h _s2 through the water and steam property calculation software package, and calculate the 2-stage extraction flow F ₂ , where The outlet water pressure P _2c and outlet water temperature t _2c of the second high-pressure generator are the same as the inlet water pressure P _1j and inlet water temperature t _1j of the first high-pressure generator;

③Calculate the cold resteam flow rate F _cr ,

F _cr ＝F _m -F ₁ -F ₂ -D _m -D _g -D _z In the above formula: D _g is the air leakage of the bridge, D _m is the air leakage of the door rod, and D _z is the rear shaft seal of the high pressure cylinder Leakage.

The improvement to the above-mentioned technical solution is: the calculation method of the reheating and desuperheating water volume is:

① Collect the pressure P _zq and temperature t _zq before the reheat desuperheater, the pressure P _zh and temperature t _zh after the reheat desuperheater, and the pressure P _rhs and temperature t _rhs of the reheat desuperheater;

② Calculate the steam enthalpy value h _zq before the reheat desuperheater, the steam enthalpy value h _zh after the reheat desuperheater, and the enthalpy value h _rhs of the reheat desuperheater water through the water and steam property calculation software package, and calculate the reheat The amount of desuperheating water F _rhs ;

The improvement to the above technical solution is: the calculation formula of the reheating steam flow is:

F _r =F _cr +F _rhs .

The beneficial effects of the present invention are:

(1) The main steam flow rate and reheat steam flow rate are calculated indirectly by using online monitoring data and benchmark data, so they are not affected by system isolation and are suitable for online calculation; (2) The main steam volume flow rate is obtained by high-precision ASME tests , and as a reference value, so the accuracy is high; (3) required parameters in the present invention, such as comprehensive valve position, generator power, pressure, temperature, etc., these parameters are all direct measurement parameters, so the parameters are easy to obtain and reliable data (4) Since the steam turbine unit needs to carry out the thermal performance test before and after each overhaul, it is beneficial for the present invention to calibrate the main steam flow coefficient.

Description of drawings

FIG. 1 is a schematic structural diagram of a system according to an embodiment of the present invention.

FIG. 2 is a schematic diagram of the arrangement of data acquisition components according to an embodiment of the present invention.

detailed description

The present invention will be described in detail below in conjunction with the accompanying drawings and specific embodiments.

Example:

As shown in Figure 1, a kind of condenser thermal load online monitoring system of the present embodiment is used for online monitoring the heat consumption rate of the condenser in the thermal power generation unit, and the system includes an online data collection module, a data preprocessing module, The performance test calibration module, the data calculation and analysis module and the terminal display module, the online data collection module is connected with the data preprocessing module, the data preprocessing module is connected with the performance test calibration module, and the performance test calibration module is connected with the data calculation and analysis module.

The online data collection module includes several pressure and temperature sensors, the electric power meter at the generator outlet of the unit and the flow sensor on the heating and extraction pipeline. The online data collection module is used to collect online data such as pressure and temperature. The processing module is used to preprocess the online data, and the performance test calibration module is used to store the benchmark data calibrated by the high-precision ASME test, receive the preprocessed data, and obtain the main steam volume flow rate and Reheat steam mass flow and other benchmark data, the data calculation and analysis module includes a data conversion module and a data calculation module, the data conversion module is used to convert the pressure and temperature data collected by the pressure and temperature sensor into density and enthalpy through the water and steam property calculation software package Value and other data, the data calculation module is used to calculate and analyze the online data and benchmark data to obtain the heat rate of the steam turbine. The terminal display module is connected with the data calculation and analysis module for receiving and displaying the heat rate data.

As shown in Figure 2, the thermal power generation unit applying the monitoring system of this embodiment includes a boiler 1, a main steam pipeline, a reheat steam pipeline, a cold resteam pipeline, a high-pressure cylinder 2, a medium-pressure cylinder 3, and a low-pressure cylinder 4 , generator 5, condenser 6, condensate pump 7, low-pressure heater 8, deaerator 9, feed water pump 10, first high-pressure heater 11, second high-pressure heater 12, third high-pressure heater 13, and finally Water supply pipeline 14, superheat desuperheater 15, reheat desuperheater 16, rewater reduction pipeline 17, one-stage steam extraction pipeline 18, heat supply and steam extraction pipeline 19, heat supply and steam extraction return water pipeline 24, superheat desuperheater The superheater 15 and the reheat desuperheater 16 are arranged in the boiler 1, the outlet of the superheater desuperheater 15 is connected with the inlet of the high-pressure cylinder 2 through the main steam pipeline, and the outlet of the high-pressure cylinder 2 is connected with the reheat desuperheater through the cold resteam pipeline. The inlet of the thermostat 16 is connected, the outlet of the reheat desuperheater 16 is connected to the inlet of the medium pressure cylinder 3 through the reheat steam pipeline, the outlet of the medium pressure cylinder 3 is connected to the inlet of the low pressure cylinder 4, and the outlet of the low pressure cylinder 4 is connected to the condensing steam Condenser 6, condensate pump 7, low-pressure heater 8, deaerator 9 and feed water pump 10 are sequentially arranged between the condenser 6 and the high-pressure heater along the water flow direction. The inlet of the thermostat 15 is connected, the heat supply and extraction steam return pipeline 24 is connected between the low pressure heater 8 and the deaerator 9, the heat supply and extraction pipeline 19 is connected to the outlet of the medium pressure cylinder 3, and a section of steam extraction pipeline 18, one end is connected to the high-pressure cylinder 2, and the other end is connected to the steam inlet of the first high-pressure heater 13, and the water reduction pipeline 17 is located between the feedwater pump 10 and the reheat desuperheater 16, and is connected to the feedwater pump 10 and the reheater desuperheater 16. The desuperheater 16 is connected, and the steam inlet of the second high-pressure heater 12 is connected with the cold resteam pipeline. The final feed water pipeline, cold resteam pipeline, reheat desuperheating water pipeline, the inlet and outlet of the reheat desuperheater, and the water inlet, water outlet, steam inlet and drain of the high pressure heater are all equipped with pressure and temperature sensor.

The online measurement method of steam turbine heat rate using the above-mentioned detection system is proposed based on the thermal performance test data and the law of conservation of system energy, including the following steps:

(1) Calculate the required benchmark data in the monitoring system through high-precision thermal performance test calibration

①Through the high-precision thermal performance test, the main steam volume flow rate corresponding to several groups of different comprehensive valve positions is tested, as shown in the formula (1):

In the formula: ψ is the comprehensive valve position value, the unit is %; Q is the main steam volume flow rate, the unit is m ³ /h;

②Test the bridge leakage D _g at the combined cylinder of the high and medium pressure cylinders through the variable steam temperature test; for the high and medium pressure split cylinder unit, this item does not need to be tested, and the value of this item is 0 by default at this time;

(2) Collect the comprehensive valve position value of the steam turbine, and obtain the main steam volume flow Q _i corresponding to the current comprehensive valve position value ψ _i by performing linear interpolation on the two columns of data described in formula (1);

At the same time, the collected main steam pressure value P _m and main steam temperature value t _m are calculated through the water and steam property calculation software package to calculate the main steam density ρ _m , and convert the volume flow rate of the main steam into the main steam mass flow rate F _m ;

(3) Calculate the main feedwater flow rate by formula (3),

F _w =F _m -D ₀ formula (3)

In the formula: F _w is the main feed water flow, the unit is t/h; F _m is the main steam flow, the unit is t/h; D ₀ is the steam and water working medium discharge on the boiler side, which is a constant, and the unit is t/h;

(4) Collect the inlet water pressure P _1j , inlet water temperature t _1j , outlet water pressure P _1c , outlet water temperature t _1c , inlet steam pressure P ₁ , inlet steam temperature t ₁ , drain pressure P _s1 , drain temperature t _s1 and other parameters, and calculate #1 high inlet water enthalpy value h _1j , outlet water enthalpy value h _1c , inlet steam enthalpy value h ₁ , hydrophobic enthalpy value h _s1 through the water and steam property calculation software package, and substitute them into the formula ( 4) Calculate the steam extraction flow F 1 of stage ₁ ;

In the formula: F _w is the main feed water flow rate, the unit is t/h; h _1c is the first highest added water enthalpy value, the unit is kJ/kg; h _1j is the first highest added water enthalpy value, the unit is kJ/kg ; h ₁ is the enthalpy value of the first high addition steam, the unit is kJ/kg; h _s1 is the first high addition hydrophobic enthalpy value, the unit is kJ/kg;

(5) Collect the second highest water inlet pressure P _2j , inlet water temperature t _2j , outlet water pressure P _2c , outlet water temperature t _2c , inlet steam pressure P ₂ , inlet steam temperature t ₂ , drain pressure P _s2 , drain temperature t _s2 and other parameters, and calculate the second highest incoming water enthalpy value h _2j , outgoing water enthalpy value h _2c , incoming steam enthalpy value h ₂ , and hydrophobic enthalpy value h _s2 through the water and steam property calculation software package, and substitute them into the formula ( 5) Calculate the steam extraction flow F ₂ in the second stage, where the outlet water pressure P _2c and outlet water temperature t _2c of the second high-pressure generator are the same as the inlet water pressure P _1j and inlet water temperature t _1j of the first high-pressure generator;

In the formula: F _w is the main feed water flow rate, the unit is t/h; h _2j is the second highest added water enthalpy value, the unit is kJ/kg; h _2c is the second highest added water enthalpy value, the unit is kJ/kg ; h _s1 is the first high addition hydrophobic enthalpy, the unit is kJ/kg; h _s2 is the second high addition hydrophobic enthalpy, the unit is kJ/kg;

(6) Calculate the main steam flow rate F _m , the first-stage extraction steam flow rate F ₁ , the second-stage extraction steam flow rate F ₂ , and the door rod leakage D _m , the bridge leakage D _g , and the high-pressure cylinder Substitute parameters such as shaft seal steam leakage D _z into formula (6) to calculate cold reheat steam flow F _cr

F _cr ＝F _m -F ₁ -F ₂ -D _m -D _g -D _z formula (6)

Among them, the steam leakage amount D _m of the door rod and the steam leakage amount D _z of the rear shaft seal of the high-pressure cylinder are handled according to the design values;

(6) By collecting the pressure P _zq and temperature t _zq before the reheat desuperheater, the pressure P _zh and temperature t _zh after the reheat desuperheater, and the pressure P _rhs and temperature t _rhs of the reheat desuperheater water, respectively through The water and steam property calculation software package calculates the steam enthalpy value h _zq before the reheat desuperheater, the steam enthalpy value h _zh after the reheat desuperheater, and the enthalpy value h _rhs of the reheat desuperheater water, and substitutes them into the formula (7 ) to calculate the amount of reheating and desuperheating water F _rhs

In the formula: F _cr is the cold reheat steam flow rate, the unit is t/h; h _zh is the steam enthalpy value after the reheat desuperheater, the unit is kJ/kg; h _zq is the steam enthalpy before the reheat desuperheater value, the unit is kJ/kg; h _rhs is the enthalpy value of reheating and desuperheating water, the unit is kJ/kg;

Substitute the cold re-steam flow rate F _cr calculated by formula (6) and the reheated desuperheating water volume F _rhs calculated by formula (7) into formula (8) to calculate the reheat steam flow rate F _r

F _r =F _cr +F _rhs formula (8)

(7) Collect the main steam pressure P _m , main steam temperature t _m , reheat steam pressure P _r , reheat steam temperature t _r , final feedwater pressure P _w , final feedwater temperature t _w , cold resteam Pressure P _cr , cold re-steam temperature t _cr , reheat desuperheating water pressure P _rhs , reheat desuperheating water temperature t _rhs , heating extraction steam pressure P _cq , heating extraction steam temperature t _cq , heating extraction steam return water pressure P _hs , heat supply extraction steam return water temperature t _hs degree etc. are input into water and steam property calculation software package to calculate main steam enthalpy h _m , reheat steam enthalpy h _r , final feedwater enthalpy h _fw , cooling Reheat steam enthalpy h _cr , reheat desuperheating water enthalpy h _rhs , heating extraction steam enthalpy h _cq , heating extraction steam return water enthalpy h _hs ; then feed water pump motor power W _f , condensate pump motor power W _n , heating extraction steam flow rate F _cq , main steam flow rate F _m calculated by formula (3), main feed water flow rate F _w calculated by formula (3), reheat steam flow rate F _r calculated by formula (8), cold water flow rate calculated by formula (6) Resteam flow rate F _cr , reheating and desuperheating water flow rate F _rhs calculated by formula (7), and the corresponding enthalpy value are substituted into formula (9) to calculate the heat Q ₀ obtained by the steam turbine system under the current operating condition of the computer group

Q ₀ ＝F _m h _m +F _r h _r -F _w h _w -F _cr h _cr -F _rhs h _rhs -F _cq (h _cq -h _hs )+3600(W _f +W _n )η _T formula ( 9)

In the formula: Q ₀ is the heat obtained by the steam turbine system, the unit is kJ/h, W _f is the power of the feed pump motor, the unit is kW; W _n is the power of the condensate pump motor, the unit is kW; η _T is the power-to-heat conversion efficiency, Take a constant, the unit is %;

(9) Calculate the heat load of the condenser according to the principle of system energy conservation and formula (10)

In the formula: Q _n is the heat obtained by the steam turbine system, the unit is kJ/h; W _c is the generator power, the unit is t/h; η _g is the generator efficiency, the unit is %; η _m is the mechanical efficiency, which is experience The value is treated as a constant, and the unit is %.

The above calculation method calibrates the main steam volume flow rate corresponding to different valve positions through the ASME performance test based on the condensate flow rate. Based on this test data, the main steam flow rate and main steam flow rate of the thermal system are calculated with the help of other auxiliary measurement data such as pressure and temperature. Feed water flow, reheat steam flow and other parameters, and then obtain the total energy entering the steam turbine system; according to the law of conservation of system energy, the heat load of the condenser is obtained after deducting the generator power and various losses from the total energy entering the steam turbine system, As a result, the final thermal load data has high accuracy, good real-time performance, and is not affected by system isolation.

The online detection system and measurement method for the heat load of the condenser of the present invention are not limited to the above-mentioned embodiments, and all technical solutions obtained by adopting equivalent replacement methods fall within the protection scope of the present invention.

Claims (10)

1. A condenser thermal load on-line monitoring system, which is used for on-line monitoring of the thermal load of the condenser in the thermal power generation unit, is characterized in that: it includes an online data collection module, a data preprocessing module, a performance test calibration module and data calculation Analysis module, the online data collection module is connected with the data preprocessing module, the data preprocessing module is connected with the performance test calibration module, the performance test calibration module is connected with the data calculation and analysis module, and the online data collection module includes several pressure and temperature sensor, the power meter at the outlet of the generator that comes with the unit, and the flow sensor on the heating and extraction pipeline. Several pressure and temperature sensors are respectively installed in the main steam pipeline, reheat steam pipeline, heating and extraction pipeline, Heat extraction steam return pipeline, final water supply pipeline, cold resteam pipeline, reheat desuperheating water pipeline, inlet and outlet of reheat desuperheater, water inlet, water outlet, steam inlet and outlet of high pressure heater At the drain port; there are three high-pressure heaters in the thermal power generating set, which are respectively the first high-pressure heater, the second high-pressure heater and the third high-pressure heater, and the online data collection module is used to collect online data, so The data preprocessing module is used to preprocess the online data, the performance test calibration module is used to store the benchmark data calibrated by the high-precision ASME test, and receives the preprocessed data, and obtains according to the preprocessed data Benchmark data such as main steam volume flow, the data calculation and analysis module is used to calculate and analyze the online data and benchmark data to obtain the heat load of the steam turbine condenser. 2. The condenser thermal load online monitoring system according to claim 1, characterized in that: the data calculation and analysis module includes a data conversion module and a data calculation module, and the data conversion module is used to calculate software through water and steam properties Package converts pressure and temperature data collected by pressure temperature sensors into data such as density and enthalpy. 3. The online monitoring system for condenser heat load according to claim 2, characterized in that: it also includes a terminal display module, the terminal display module is connected with the data calculation and analysis module for receiving the condenser heat load data and performing show. 4. A condenser thermal load on-line measurement method adopting the condenser thermal load on-line monitoring system described in claim 3, is characterized in that comprising the steps: Step 1. Collect online data such as the pressure and temperature of steam and water in each pipeline in the thermal power generation unit through pressure and temperature sensors, and collect online data such as generator power and heating and extraction volume in the DCS system of the thermal power generation unit; Step 2. Calculate the required benchmark data through ASME test calibration; Step 3, using the water and steam property calculation software package to calculate the density and enthalpy data of steam and water according to the pressure and temperature data collected in step 1; Step 4, calculate the mass flow rate of steam and water in each pipeline in the thermal power generating set; Step 5, calculate the heat obtained by the steam turbine system in the thermal power generating set, Q ₀ ＝F _m h _m +F _r h _r -F _w h _w -F _cr h _cr -F _rhs h _rhs -F _cq (h _cq -h _hs )+3600(W _f +W _n )η _T In the formula: Q ₀ is the heat obtained by the steam turbine system, F _m is the main steam flow rate, h _m is the main steam enthalpy value, F _r is the reheat steam flow rate, h _r is the reheat steam enthalpy value, F _w is the final feed water flow rate , h _w is the final feed water enthalpy value, F _cr is the cold resteam flow rate, h _cr is the cold resteam enthalpy value, F _rhs is the reheat desuperheating water flow rate, h _rhs is the reheat desuperheating water enthalpy value, F _cq is the heating Extraction steam flow, h _cq is heat extraction steam enthalpy, h _hs is heat extraction steam return enthalpy, W _f is feed water pump motor power, kW; W _n is condensate pump motor power, η _T is work heat conversion efficiency; Step 6, calculating the heat load of the condenser; Calculate the heat load of the condenser according to the principle of system energy conservation; Where: Q _n is the heat load of the condenser, W _c is the power of the generator, η _g is the efficiency of the generator, and η _m is the mechanical efficiency. 5. according to the said condenser thermal load on-line measurement method of claim 4, it is characterized in that: the content of ASME test in the described step 2 is: ①Through the high-precision thermal performance test to test the main steam volume flow rate corresponding to the comprehensive valve position of different steam turbines, ② Test the bridge leakage D _g at the junction of the high-pressure cylinder and the medium-pressure cylinder through the variable steam temperature test. 6. The method for online measurement of condenser heat load according to claim 5, wherein the mass flow calculated in step 4 includes main steam mass flow, final feed water flow, cold resteam flow, reheating and desuperheating water volume and reheat steam flow. 7. according to claim 6 described condenser thermal load online measuring method, it is characterized in that: the calculation method of described main steam mass flow rate is: ①Collect the steam turbine integrated valve position value ψ _i , and obtain the main steam volume flow Q _i corresponding to the current integrated valve position value ψ _i according to the benchmark data in step 2; ②Collect the main steam pressure value P _m and the main steam temperature value t _m , and calculate the main steam density ρ _m through the water and steam property calculation software package; ③ Calculate the main steam mass flow rate F _m by using the main steam volume flow rate Q _i and the main steam density ρ _m ; The calculation method of the final feed water flow is: F _w =F _m +D ₀ In the above formula: D ₀ is the discharge volume of steam and water on the furnace side. 8. According to the online measurement method of the heat load of the condenser according to claim 7, it is characterized in that: the calculation method of the cold re-steam flow is: ① Collect the inlet water pressure P _1j , inlet water temperature t _1j , outlet water pressure P _1c , outlet water temperature t _1c , inlet steam pressure P ₁ , inlet steam temperature t ₁ , drain pressure P _s1 , drain temperature t of the first high pressure heater _s1 and other parameters; Calculate the inlet water enthalpy value h _1j , the outlet water enthalpy value h _1c , the inlet steam enthalpy value h ₁ , and the drain enthalpy value h _s1 of the high pressure heater through the water and steam property calculation software package, and calculate the extraction flow F ₁ ; ② Collect the second highest water inlet pressure P _2j , inlet water temperature t _2j , outlet water pressure P _2c , outlet water temperature t _2c , inlet steam pressure P ₂ , inlet steam temperature t ₂ , drain pressure P _s2 , drain temperature t _s2 , etc. parameter; Calculate #2 high inlet water enthalpy value h _2j , outlet water enthalpy value h _2c , inlet steam enthalpy value h ₂ , and hydrophobic enthalpy value h _s2 through the water and steam property calculation software package, and calculate the 2-stage extraction flow F ₂ , where The outlet water pressure P _2c and outlet water temperature t _2c of the second high-pressure pump are the same as the first high-pressure water inlet pressure P _1j and water inlet temperature t _1j . ③Calculate the cold resteam flow rate F _cr , F _cr ＝F _m -F ₁ -F ₂ -D _m -D _g -D _z In the above formula: D _g is the air leakage of the bridge, D _m is the air leakage of the door rod, and D _z is the rear shaft seal of the high pressure cylinder Leakage. 9. According to the online measurement method of the thermal load of the condenser according to claim 8, it is characterized in that: the calculation method of the reheating and desuperheating water volume is: ① Collect the pressure P _zq and temperature t _zq before the reheat desuperheater, the pressure P _zh and temperature t _zh after the reheat desuperheater, and the pressure P _rhs and temperature t _rhs of the reheat desuperheater; ② Calculate the steam enthalpy value h _zq before the reheat desuperheater, the steam enthalpy value h _zh after the reheat desuperheater, and the enthalpy value h _rhs of the reheat desuperheater water through the water and steam property calculation software package, and calculate the reheat The amount of desuperheating water F _rhs ; 10. The method for online measurement of the thermal load of the condenser according to claim 9, wherein the formula for calculating the flow rate of the reheated steam is: F _r =F _cr +F _rhs .