Method and system for automatically regulating and controlling water level of condenser hot well of thermal power generating unit

Abstract

The invention discloses a thermal power generating unit condenser hot well water level automatic regulation and control method and system, and the method comprises the steps: obtaining hot well water level regulation and control comprehensive data of a thermal power generating unit, the hot well water level regulation and control comprehensive data comprises condenser hot well water level data, deaerator water tank water level data, hot well demineralized water replenishing flow data, deaerator water tank pressure data and hot well pressure data; according to the hot well water level regulation and control comprehensive data of the thermal power generating unit, the corrected hot well water level is calculated; on the basis of five threshold intervals formed by four control thresholds set from low to high, the threshold interval where the water level of the hot well is located is judged and corrected, and an interval judgment result is obtained; based on the interval judgment result, a corresponding operation instruction is sent to an execution mechanism; automatic regulation and control of the hot well water level can be achieved, the hot well water level is kept within the optimal safety range, and safe and reliable operation of a unit is guaranteed.

Description

Technical Field

[0001] The present invention relates to the technical field of automatic control of thermal power units, and in particular to a method and system for automatically controlling the water level of a condenser hot well of a thermal power unit. Background Art

[0002] In the thermal power unit steam turbine thermal system, leakage of working fluids, such as industrial heating, deaerator exhaust, condensate and feedwater sampling, boiler drain leaks, and boiler sootblowing, can cause the water levels in the deaerator tank and hot well to drop. Currently, the deaerator tank water level is controlled using a three-impulse control strategy based on steam flow, condensate flow, and deaerator tank water level. This strategy, coupled with a variable-frequency condensate pump, achieves dynamic regulation, controlling the deaerator tank water level to fluctuate slightly around a set level.

[0003] However, thermal power unit hot well water level control systems have significant limitations. First, monitoring methods are crude, relying on manual meter reading and periodic water balance tests. These methods struggle to capture dynamic fluid changes such as boiler soot blowing, deaerator oxygen discharge, and boiler drain leakage in real time, resulting in delayed response under abnormal operating conditions. Second, control methods lack flexibility, relying entirely on operator experience to manually adjust the start and stop of feedwater pumps, making them unable to adapt to the nonlinear fluctuations in leakage rates under varying operating conditions. This is particularly true in the context of new power systems, where frequent peak load regulation exacerbates load fluctuations. When load suddenly increases, turbine steam intake and feedwater flow increase dramatically, forcing condensate pumps to rapidly draw water from the hot well to meet demand, causing a temporary drop in water level. A sudden drop in load, however, results in a temporary rise in water level. These frequent and large water level fluctuations render traditional manual control methods incapable of meeting the precise hot well water level control requirements of new power systems. Furthermore, the persistent impact of fluid leakage significantly increases the difficulty of water level regulation. Summary of the Invention

[0004] The object of the present invention is to provide a method and system for automatically controlling the hot well water level of a condenser of a thermal power unit. The method and system can calculate a corrected hot well water level through comprehensive hot well water level control data, and use the corrected hot well water level as a variable to determine the threshold range in which the corrected hot well water level is located, and issue corresponding operating instructions to an actuator, thereby realizing automatic control of the hot well water level, so that the hot well water level is maintained within an optimal safety range, thereby ensuring safe and reliable operation of the unit.

[0005] In order to achieve the above object, the present invention adopts the following technical solutions:

[0006] In a first aspect, the present invention provides a method for automatically controlling the water level in a condenser hot well of a thermal power unit, comprising:

[0007] Obtaining comprehensive data on the hot well water level control of the thermal power unit, the comprehensive data on the hot well water level control including: condenser hot well water level data, deaerator water tank water level data, hot well desalted water replenishment flow data, deaerator water tank pressure data, and hot well pressure data;

[0008] Calculate and correct the hot well water level based on the comprehensive data of hot well water level control of thermal power units;

[0009] Based on five threshold intervals formed by four control thresholds set from low to high, the threshold interval in which the water level of the corrected hot well is located is determined, and an interval determination result is obtained;

[0010] Based on the interval judgment results, corresponding operation instructions are issued to the actuator, thereby realizing automatic control of the hot well water level.

[0011] Optionally, the calculation of the corrected hot well water level according to the comprehensive data of hot well water level control of the thermal power unit includes:

[0012] Get the water volume setting value of the deaerator tank;

[0013] Based on the condenser hot well water level data, the hot well water level at the current moment is obtained;

[0014] Based on the deaerator water tank water level data, the current deaerator water tank water level is obtained;

[0015] Calculate the water volume of the deaerator water tank at the current moment according to the water level of the deaerator water tank at the current moment, the known length of the deaerator water tank, the intercept and radius of the head;

[0016] Calculate the density of hot well water and deaerator tank water by combining the IAPWS-IF97 water vapor property formula, hot well pressure data, and deaerator tank pressure data.

[0017] Based on the known length and width of the hot well cross section, the water density of the deaerator water tank, the hot well water density, the current hot well water level, the deaerator water tank water volume setting value, and the current deaerator water tank water volume, the corrected hot well water level is calculated using the following formula:

[0018] ;

[0019] Where, Indicates the corrected hot well water level; Indicates the hot well water level at the current moment; Indicates the water volume setting value of the deaerator water tank; Indicates the water density of the deaerator tank; Indicates the water volume of the deaerator tank at the current moment; represents the water density of the hot well; M and N represent the length and width of the hot well cross section, respectively.

[0020] Optionally, the five threshold intervals formed by the four control thresholds set from low to high are used to determine the threshold interval in which the water level of the corrected hot well is located, and obtain the interval determination result, including:

[0021] Get the four control thresholds that have been set. The four control thresholds from low to high are: H1, H2, H4 and H5;

[0022] Based on the four control thresholds, five threshold intervals are formed: , , , and ;

[0023] The threshold range of the corrected hot well water level is determined, thereby obtaining an interval determination result.

[0024] Optionally, issuing a corresponding operation instruction to an execution mechanism based on the interval judgment result includes:

[0025] When the corrected hot well water level is When the water level in the hot well is lowered to H4, a high-level alarm signal and a first operation instruction are issued; the first operation instruction includes: closing the water supply pump, closing the water supply regulating valve, opening the low-pressure heater drain valve, and actively lowering the hot well water level until the corrected hot well water level is lowered to H4;

[0026] When the corrected hot well water level is When the second operation instruction is issued, the second operation instruction includes: closing the water supply pump and the water supply regulating valve;

[0027] When the corrected hot well water level is When the water supply is full, a third operation instruction is issued; the third operation instruction includes: closing the water supply pump, and adjusting the opening of the water supply regulating valve to control the water supply flow rate, so that the water supply flow rate is equal to the leakage flow rate within the previous first preset time interval;

[0028] When the corrected hot well water level is When the water level in the hot well reaches the middle water level, the water level in the hot well reaches the middle water level. ... ; Among them, for the correction of hot well water level During the water replenishment process, when the corrected hot well water level reaches The third operation instruction is not sent during the interval.

[0029] When the corrected hot well water level is When the water level in the hot well reaches H3, a low level alarm signal and a fifth operation instruction are issued; the fifth operation instruction includes: starting the water supply pump and adjusting the opening of the water supply regulating valve to 100% to supply water until the water level in the hot well reaches H3; wherein, during the water supply process when the water level in the hot well is lower than H1, when the water level in the hot well reaches The third operation instruction and the fourth operation instruction are not sent during the interval.

[0030] Optionally, the calculation process of the leakage flow rate within the previous first preset time interval includes:

[0031] Based on the hot well desalted water replenishment flow rate data, the average replenishment flow rate at the start and end time points of the previous first preset time interval is obtained;

[0032] Calculating the hot well equivalent flow rate for a previous first preset time interval based on the condenser hot well water level data, the known length and width of the hot well cross section, the hot well pressure data, and the first preset time interval;

[0033] Calculate the deaerator tank equivalent flow rate for a current first preset time interval based on the deaerator tank water level data, the known deaerator tank length, the head intercept and radius, the deaerator tank pressure data, and the first preset time interval;

[0034] The average water replenishment flow, the hot well equivalent flow and the deaerator water tank equivalent flow in the previous first preset time interval are added together to obtain the leakage flow in the previous first preset time interval.

[0035] Optionally, the step of calculating the hot well equivalent flow rate for a previous first preset time interval based on the condenser hot well water level data, the known length and width of the hot well cross section, the hot well pressure data, and the first preset time interval includes:

[0036] Based on the condenser hot well water level data, the hot well water level at the start and end time points of the previous first preset time interval is obtained;

[0037] Calculate the volume of the hot well water at the start and end time points of the previous first preset time interval based on the hot well water levels at the start and end time points of the previous first preset time interval and the known length and width of the hot well cross section;

[0038] Using the IAPWS-IF97 water vapor property formula and hot well pressure data, calculate the hot well water density;

[0039] Calculate the hot well equivalent flow rate for the previous first preset time interval by combining the first preset time interval, the hot well water level and hot well water volume at the start and end time points of the previous first preset time interval, and the hot well water density;

[0040] The calculation formula of the hot well equivalent flow rate in the previous first preset time interval is expressed as:

[0041] ;

[0042] Where, Indicates the hot well equivalent flow rate during the previous first preset time interval; Respectively represent the hot well water volume at the start and end time points of the previous first preset time interval; represents a first preset time interval; Represents the density of hot well water.

[0043] Optionally, the calculating the deaerator water tank equivalent flow rate for a current first preset time interval based on the deaerator water tank water level data, the known deaerator water tank length, the head intercept and radius, the deaerator water tank pressure data, and the first preset time interval includes:

[0044] Based on the deaerator water tank water level data, the deaerator water tank water level at the start and end time points of the previous first preset time interval is obtained;

[0045] Calculate the water volume of the deaerator water tank at the start and end time points of the previous first preset time interval based on the water level of the deaerator water tank at the start and end time points of the previous first preset time interval, and the known length, head intercept, and radius of the deaerator water tank;

[0046] Calculate the water density in the deaerator tank using the IAPWS - IF97 water vapor property formula and the deaerator tank pressure data;

[0047] Calculate the equivalent flow rate of the deaerator water tank for the previous first preset time interval by combining the first preset time interval, the water volume of the deaerator water tank at the start and end time points of the previous first preset time interval, and the water density of the deaerator water tank;

[0048] The calculation formula of the deaerator water tank equivalent flow rate at the previous first preset time interval is expressed as:

[0049] ;

[0050] Where, Indicates the deaerator tank equivalent flow rate during the previous first preset time interval; Respectively represent the water volume of the deaerator tank at the start and end time points of the previous first preset time interval; Indicates a time interval; Indicates the water density of the deaerator tank.

[0051] Optionally, the calculation formula for the flow rate corresponding to the water level from the corrected hot well water level to the middle water level holding value within the second preset time interval is:

[0052] ;

[0053] Where, Indicates the flow rate corresponding to the water level of the corrected hot well reaching the medium water level holding value within the second preset time interval; Indicates the hot well water volume corresponding to the hot well water level when the hot well water level is the medium water level maintenance value H3; Indicates the hot well water volume corresponding to the corrected hot well water level; Indicates the second preset time interval.

[0054] In a second aspect, the present invention provides a thermal power unit condenser hot well water level automatic control system, comprising:

[0055] Data acquisition module, used to collect comprehensive data on thermal well water level control of thermal power units;

[0056] A data processing module, connected to the data acquisition module, for executing the method for automatically controlling the water level of the condenser hot well of a thermal power unit as described in the first aspect;

[0057] The execution mechanism is connected to the data processing module and is used to receive and execute corresponding operation instructions.

[0058] Optionally, the data acquisition module includes:

[0059] Multi-channel ultrasonic flowmeter is used to collect the desalted water replenishment flow rate of hot wells in real time and obtain the desalted water replenishment flow rate data;

[0060] Hot well water level gauge, used to collect hot well water level in real time and obtain condenser hot well water level data;

[0061] Deaerator water tank water level gauge, used to collect the deaerator water tank water level in real time and obtain the deaerator water tank water level data;

[0062] Hot well pressure transmitter, used to collect hot well pressure in real time and obtain hot well pressure data;

[0063] The deaerator pressure transmitter is used to collect the deaerator water tank pressure in real time and obtain the deaerator water tank pressure data.

[0064] Compared with the prior art, the present invention has the following beneficial effects:

[0065] The present invention provides a method and system for automatically controlling the hot well water level of a condenser of a thermal power unit. The method calculates a corrected hot well water level through comprehensive hot well water level control data of the thermal power unit, wherein the comprehensive hot well water level control data includes: condenser hot well water level data, deaerator water tank water level data, hot well desalted water replenishment flow data, deaerator water tank pressure data and hot well pressure data; and determines in which of five threshold value intervals the corrected hot well water level is formed by four control threshold values set from low to high, thereby issuing corresponding operation instructions to an actuator, thereby realizing automatic control of the hot well water level; wherein the operation objects of the corresponding operation instructions are a water replenishment pump and a water replenishment regulating valve, the opening of the water replenishment regulating valve is adjusted according to the water replenishment amount, and the water replenishment amount can be calculated according to the leakage flow and the target water level; in summary, the present invention can avoid the control shortcomings of traditional manual adjustment methods and meet the requirements of new power systems for precise control of hot well water levels. BRIEF DESCRIPTION OF THE DRAWINGS

[0066] Figure 1 FIG2 is a flow chart of a method for automatically controlling the water level of a condenser hot well of a thermal power unit according to an embodiment of the present invention;

[0067] Figure 2 FIG. 4 is a detailed flow chart of S4 in one embodiment of the present invention;

[0068] Figure 3 FIG2 is a schematic diagram of a calculation process of leakage flow within a first preset time interval in an embodiment of the present invention;

[0069] Figure 4 Shown is a schematic diagram of a longitudinal section of a deaerator water tank in one embodiment of the present invention;

[0070] Figure 5 Shown is a schematic diagram of a longitudinal section of a hot well in one embodiment of the present invention;

[0071] Figure 6 The figure shows a schematic diagram of thermal system leakage and condenser hot well water replenishment of a thermal power unit in one embodiment of the present invention;

[0072] In the figure: 1. hot well, 2. condensate pump, 3. low-pressure heater, 4. deaerator water tank, 5. high-pressure heater, 6. boiler, 7. steam turbine, 8. deaerator exhaust pipe, 9. boiler drain pipe, 10. steam turbine heating pipe, 11. desalted water tank, 12. make-up water pump, 13. make-up water regulating valve, 14. multi-channel ultrasonic flowmeter, 15. hot well water level gauge, 16. deaerator water tank water level gauge, 17. hot well pressure transmitter, 18. deaerator pressure transmitter, 19. low-pressure heater drain valve. DETAILED DESCRIPTION

[0073] The present invention will be further described below in conjunction with the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solutions of the present invention and are not intended to limit the scope of protection of the present invention.

[0074] Example 1

[0075] like Figure 1 As shown, the embodiment of the present invention introduces a method for automatically controlling the water level of a condenser hot well of a thermal power unit, comprising the following steps:

[0076] S1: Obtain comprehensive data on the hot well water level control of the thermal power unit, wherein the comprehensive data includes: condenser hot well water level data, deaerator water tank water level data, hot well desalted water replenishment flow data, deaerator water tank pressure data, and hot well pressure data;

[0077] S2: Calculate and correct the hot well water level based on the comprehensive data of hot well water level control of thermal power units;

[0078] S3: Based on the five threshold intervals formed by the four control thresholds set from low to high, determine the threshold interval in which the water level of the corrected hot well is located, and obtain an interval determination result;

[0079] S4: Based on the interval judgment result, the corresponding operation instruction is issued to the actuator, thereby realizing the automatic control of the hot well water level.

[0080] This embodiment provides a method for automatically controlling the hot well water level of a condenser in a thermal power unit. The method can calculate a corrected hot well water level based on comprehensive hot well water level control data, use the corrected hot well water level as a variable, determine the threshold range in which the corrected hot well water level is located, and issue corresponding operating instructions to an actuator, thereby realizing automatic control of the hot well water level, keeping the hot well water level within an optimal safety range, and ensuring safe and reliable operation of the unit.

[0081] In this embodiment, the condenser hot well water level data, the deaerator water tank water level data, the hot well desalted water replenishment flow data, the deaerator water tank pressure data and the hot well pressure data in step S1 are respectively collected by the hot well water level gauge, the deaerator water tank water level gauge, the multi-channel ultrasonic flow meter, the deaerator pressure transmitter and the hot well pressure transmitter.

[0082] In this embodiment, in step S2, the calculation of the corrected hot well water level according to the comprehensive data of the hot well water level control of the thermal power unit includes:

[0083] S21: Obtain the water volume setting value of the deaerator water tank;

[0084] S22: Based on the condenser hot well water level data, obtain the hot well water level at the current moment;

[0085] S23: Based on the deaerator water tank water level data, obtain the current deaerator water tank water level;

[0086] S24: Calculate the water volume of the deaerator water tank at the current moment according to the water level of the deaerator water tank at the current moment, the known length of the deaerator water tank, the head intercept and the radius;

[0087] Specifically, such as Figure 4 The figure shows the longitudinal section of the deaerator water tank. The length of the deaerator water tank is , the head intercept is s and the radius is r, the water volume of the deaerator tank at the current moment is calculated by the following formula :

[0088]

[0089] in, is the deaerator water level at the current moment;

[0090] S25: Calculate the hot well water density and the deaerator water tank water density by combining the IAPWS-IF97 water vapor property formula, the hot well pressure data, and the deaerator water tank pressure data. Calculating water density is common knowledge to those skilled in the art and will not be described in detail here.

[0091] S26: Calculate a corrected hot well water level based on the known length and width of the hot well cross section, the water density of the deaerator water tank, the hot well water density, the current hot well water level, the set value of the water volume of the deaerator water tank, and the current deaerator water tank water volume;

[0092] Specifically, the water level in the deaerator tank fluctuates slightly around the set water level value H. There is a fixed set water volume in the deaerator tank, and there is a set water quality in the deaerator tank under different operating conditions. The definition of the corrected hot well water level is: at the same moment, the difference between the actual operating water quality of the deaerator tank and the set water quality is physically mapped to the equivalent mass water level height in the hot well, and the superposition value of the current operating water level of the hot well. Specifically, the correction value is formed by quantifying the dynamic deviation of the deaerator tank water level around the set value, converting this deviation into the equivalent mass water level height under the hot well water level, and linearly superimposing it with the real-time water level of the hot well to form a comprehensive water level parameter;

[0093] The formula is as follows:

[0094] ;

[0095] Where, Indicates the corrected hot well water level; Indicates the hot well water level at the current moment; Indicates the water volume setting value of the deaerator water tank; Indicates the water density of the deaerator tank; Indicates the water volume of the deaerator tank at the current moment; represents the water density of the hot well; M and N represent the length and width of the hot well cross section, respectively.

[0096] In this embodiment, step S3 determines the threshold interval in which the water level of the corrected hot well is located based on five threshold intervals formed by four control thresholds set from low to high, and obtains interval determination results, including:

[0097] Get the four control thresholds that have been set. The four control thresholds are from low to high: hot well low water level alarm value H1, hot well low water level holding value H2, hot well high water level holding value H4 and hot well high water level alarm value H5;

[0098] Based on the four control thresholds, five threshold intervals are formed: , , , and ;

[0099] The threshold range of the corrected hot well water level is determined, thereby obtaining an interval determination result.

[0100] like Figure 2 As shown, in this embodiment, the step S4 of issuing corresponding operation instructions to the execution mechanism based on the interval judgment result includes:

[0101] When the corrected hot well water level is When the water level in the hot well is lowered to H4, a high-level alarm signal and a first operation instruction are issued; the first operation instruction includes: closing the water supply pump, closing the water supply regulating valve, opening the low-pressure heater drain valve, and actively lowering the hot well water level until the corrected hot well water level is lowered to H4;

[0102] When the corrected hot well water level is When the second operation instruction is issued, the second operation instruction includes: closing the water supply pump and the water supply regulating valve;

[0103] When the corrected hot well water level is When the water supply is full, a third operation instruction is issued; the third operation instruction includes: closing the water supply pump, and adjusting the opening of the water supply regulating valve to control the water supply flow rate, so that the water supply flow rate is equal to the leakage flow rate within the previous first preset time interval;

[0104] When the corrected hot well water level is When the water level in the hot well reaches the middle water level, the water level in the hot well reaches the middle water level. ... ; Among them, for the correction of hot well water level During the water replenishment process, when the corrected hot well water level reaches The third operation instruction is not sent during the interval.

[0105] When the corrected hot well water level is When the water level in the hot well reaches H3, a low level alarm signal and a fifth operation instruction are issued; the fifth operation instruction includes: starting the water supply pump and adjusting the opening of the water supply regulating valve to 100% to supply water until the water level in the hot well reaches H3; wherein, during the water supply process when the water level in the hot well is lower than H1, when the water level in the hot well reaches The third operation instruction and the fourth operation instruction are not sent during the interval.

[0106] In this embodiment, if Figure 3 The calculation process of the leakage flow rate within the previous first preset time interval includes:

[0107] S01: obtaining the average water replenishment flow rate at the start and end time points of the previous first preset time interval based on the hot well desalted water replenishment flow rate data;

[0108] S02: Calculating the hot well equivalent flow rate for the previous first preset time interval based on the condenser hot well water level data, the known length and width of the hot well cross section, the hot well pressure data, and the first preset time interval;

[0109] S03: Calculating the deaerator tank equivalent flow rate for a current first preset time interval based on the deaerator tank water level data, the known deaerator tank length, the head intercept and radius, the deaerator tank pressure data, and the first preset time interval;

[0110] S04: Add the average water replenishment flow rate, the hot well equivalent flow rate, and the deaerator water tank equivalent flow rate in the previous first preset time interval to obtain the leakage flow rate in the previous first preset time interval.

[0111] Specifically, in S02, based on the condenser hot well water level data, the known length and width of the hot well cross section, the hot well pressure data, and the first preset time interval, calculating the hot well equivalent flow rate for the previous first preset time interval includes:

[0112] Based on the condenser hot well water level data, the hot well water level at the start and end time points of the previous first preset time interval is obtained;

[0113] Calculate the volume of the hot well water at the start and end time points of the previous first preset time interval based on the hot well water levels at the start and end time points of the previous first preset time interval and the known length and width of the hot well cross section;

[0114] Specifically, such as Figure 5 The figure shows a longitudinal section of a hot well. The calculation formula for the hot well water volume is as follows:

[0115]

[0116] Where M and N are the length and width of the hot well cross section respectively; is the water level of the hot well at a certain moment, i.e., time point; is the volume of hot well water at a certain moment, i.e., time point;

[0117] Using the IAPWS-IF97 water vapor property formula and hot well pressure data, calculate the hot well water density;

[0118] Calculate the hot well equivalent flow rate for the previous first preset time interval by combining the first preset time interval, the hot well water level and hot well water volume at the start and end time points of the previous first preset time interval, and the hot well water density;

[0119] The calculation formula of the hot well equivalent flow rate in the previous first preset time interval is expressed as:

[0120] ;

[0121] Where, Indicates the hot well equivalent flow rate during the previous first preset time interval; Respectively represent the hot well water volume at the start and end time points of the previous first preset time interval; Indicates a time interval; Represents the density of hot well water.

[0122] Specifically, in S03, based on the deaerator water tank water level data, the known deaerator water tank length, the head intercept and radius, the deaerator water tank pressure data, and the first preset time interval, the deaerator water tank equivalent flow rate for the current first preset time interval is calculated, including:

[0123] Based on the deaerator water tank water level data, the deaerator water tank water level at the start and end time points of the previous first preset time interval is obtained;

[0124] Calculate the water volume of the deaerator water tank at the start and end time points of the previous first preset time interval based on the water level of the deaerator water tank at the start and end time points of the previous first preset time interval, and the known length, head intercept, and radius of the deaerator water tank;

[0125] Calculate the water density in the deaerator tank using the IAPWS - IF97 water vapor property formula and the deaerator tank pressure data;

[0126] Calculate the equivalent flow rate of the deaerator water tank for the previous first preset time interval by combining the first preset time interval, the water volume of the deaerator water tank at the start and end time points of the previous first preset time interval, and the water density of the deaerator water tank;

[0127] The calculation formula of the deaerator water tank equivalent flow rate at the previous first preset time interval is expressed as:

[0128] ;

[0129] Where, Indicates the deaerator water tank equivalent flow rate during the previous first preset time interval; Respectively represent the water volume of the deaerator tank at the start and end time points of the previous first preset time interval; Indicates a time interval; Indicates the water density of the deaerator tank.

[0130] In this embodiment, when the corrected hot well water level is When the water level reaches the middle water level, the fourth operation instruction is issued; the fourth operation instruction includes: starting the water supply pump and adjusting the opening of the water supply regulating valve to control the water supply flow, so that the water supply flow is the sum of the leakage flow in the previous first preset time interval and the flow corresponding to the water level maintenance value reached from the corrected hot well water level in the second preset time interval, wherein the calculation formula for the flow corresponding to the water level maintenance value reached from the corrected hot well water level in the second preset time interval is:

[0131] ;

[0132] Where, Indicates the flow rate corresponding to the water level of the corrected hot well reaching the medium water level holding value within the second preset time interval; Indicates the hot well water volume corresponding to the hot well water level when the hot well water level is the medium water level maintenance value H3; Indicates the hot well water volume corresponding to the corrected hot well water level.

[0133] Example 2

[0134] Based on this embodiment, a method for automatically controlling the water level of a condenser hot well of a thermal power unit is provided, with the following two control cases:

[0135] (1) Case 1:

[0136] A 600MW unit has four control thresholds: H1 is 600mm, H2 is 900mm, H4 is 1500mm, H5 is 1800mm; the water level holding value H3 is 1200mm, and the deaerator size is L C= 24m, r = 2.2m, s = 1m, and the hot well dimensions are M = 15m and N = 12m. Set the deaerator tank operating water level to 3600mm (the deaerator tank water volume setting can be further obtained by setting the deaerator tank operating water level). Set the first preset time interval to 10 minutes. Set the previous first preset time interval to 0:00-00:10. The current time is 00:10.

[0137] At 00:00, the water level of the hot well is 905mm, and the water level of the deaerator tank is 3650mm. At 00:10, the water level of the hot well is 890mm, and the water level of the deaerator is 3660mm. The average pressure of the condenser during the period of 0:00-00:10 is 6kPa, and the average pressure of the deaerator is 0.88MPa. The average flow rate of the hot well desalted water is Q 补 =5t / h.

[0138] First, calculate the hot well equivalent flow rate, deaerator water tank equivalent flow rate, and leakage flow rate during the first preset time interval of 00:00-0:10:

[0139] Based on the deaerator tank pressure of 0.88 MPa, the water density in the deaerator tank is calculated to be 892.9 kg / m³ using the IAPWS-IF97 water vapor properties formula. At 00:00, the water level was 3.65 m, and the deaerator tank water volume calculation formula was 342.34 m³. At 00:10, the water level was 3.66 m, and the deaerator tank water volume calculation formula was 343.17 m³. The deaerator water level rose, and the deaerator equivalent flow rate was -4.45 t / h.

[0140] Based on a hot well pressure of 0.006 MPa, the IAPWS-IF97 water vapor property formula was used to calculate the hot well water density to be 993.6 kg / m³. At 00:00, the water level was 0.905 m, and the hot well water volume was calculated to be 162.9 m³ using the hot well volume calculation formula. At 00:10, the water level was 0.890 m, and the hot well water volume was calculated to be 160.2 m³ using the hot well volume calculation formula. The hot well water level was declining, and the hot well equivalent flow rate was 16.10 t / h.

[0141] The leakage of the thermal system is -4.45+16.10+5=16.65 t / h.

[0142] Secondly, the deaerator water tank is set to a water level of 3.6m, the deaerator water tank is set to a water volume of 338.12m³, and the corrected hot well water level is

[0143] If the corrected hot well water level is higher than the H2 water level and lower than the H4 water level, an operating instruction is issued to shut down the water supply pump and control the water supply flow rate to 16.65t / h by adjusting the opening of the water supply regulating valve.

[0144] (2) Case 2:

[0145] A 600MW unit has four control thresholds: H1 is 600mm, H2 is 900mm, H4 is 1500mm, H5 is 1800mm; the water level holding value H3 is 1200mm, and the deaerator size is L C = 24m, r = 2.2m, s = 1m, and the hot well dimensions are M = 15m and N = 12m. Set the deaerator tank operating water level to 3600mm (the deaerator tank water volume setting can be further obtained by setting the deaerator tank operating water level). Set the first preset time interval to 10 minutes. Set the previous first preset time interval to 00:00-00:10. The current time is 00:10.

[0146] At 00:01, the water level of the hot well is 885mm, and the water level of the deaerator tank is 3650mm. At 00:10, the water level of the hot well is 870mm, and the water level of the deaerator is 3660mm. The average pressure of the condenser during the period of 0:00-00:10 is 6kPa, and the average pressure of the deaerator is 0.88MPa. The average flow rate of the hot well desalted water is Q 补 =5t / h.

[0147] First, calculate the hot well equivalent flow rate, deaerator water tank equivalent flow rate, and leakage flow rate during the 00:00-0:10 time period:

[0148] Based on the deaerator tank pressure of 0.88 MPa, the water density in the deaerator tank is calculated to be 892.9 kg / m³ using the IAPWS-IF97 water vapor properties formula. At 00:00, the water level was 3.65 m, and the deaerator tank water volume calculation formula was 342.34 m³. At 00:10, the water level was 3.66 m, and the deaerator tank water volume calculation formula was 343.17 m³. The deaerator water level rose, and the deaerator equivalent flow rate was -4.45 t / h.

[0149] Based on a hot well pressure of 0.006 MPa, the IAPWS-IF97 water vapor property formula was used to calculate the hot well water density to be 993.6 kg / m³. At 00:00, the water level was 0.885 m, and the hot well water volume was calculated to be 159.3 m³ using the hot well volume calculation formula. At 00:10, the water level was 0.870 m, and the hot well water volume was calculated to be 156.6 m³ using the hot well volume calculation formula. The hot well water level was declining, and the hot well equivalent flow rate was 16.10 t / h.

[0150] The leakage of the thermal system is -4.45+16.10+5=16.65 t / h.

[0151] Secondly, the deaerator water tank is set to 3.6m, the deaerator water tank is set to 338.12m³, and the corrected hot well water level is .

[0152] If the water level of the corrected hot well is higher than the H1 level and lower than the H2 level, the water supply pump will be shut down and the water supply regulating valve will be adjusted to control the water supply flow rate to t / h (tons / hour) operation instruction, where 1h (hour) is the second preset time interval.

[0153] Based on the above case and the method for automatically controlling the hot well water level of the condenser of a thermal power unit described in Example 1, the present invention should explain that: for the control of the hot well water level, the control frequency is set to once per minute, so that the calculation frequency of the leakage flow is also once per minute;

[0154] Specifically, the sliding window average algorithm can be used to calculate the leakage flow of the previous first preset time interval. For example, in Case 1, the current time is 00:10. Since the first time interval is set to 10 minutes, the average data of the window is calculated when calculating the average water replenishment flow, hot well equivalent flow and deaerator water tank equivalent flow of the previous first preset time interval to obtain the leakage flow of the previous first preset time interval; at 00:10, if the corrected hot well water level is When the water supply is 100%, the third operation instruction is issued; the third operation instruction includes: closing the water supply pump and adjusting the opening of the water supply regulating valve to control the water supply flow rate so that the water supply flow rate is equal to the leakage flow rate at 00:00-00:10;

[0155] Based on Case 1, Case 2 is about the automatic regulation of the hot well water level at 00:11 in one minute. The sliding window average algorithm is also used to calculate the average water replenishment flow, hot well equivalent flow and deaerator tank equivalent flow from 00:01 to 00:11. The average data of the window is calculated to obtain the leakage flow from 00:01 to 00:11.

[0156] Example 3

[0157] This embodiment provides a thermal power unit condenser hot well water level automatic control system, comprising:

[0158] Data acquisition module, used to collect comprehensive data on thermal well water level control of thermal power units;

[0159] a data processing module connected to the data acquisition module, and configured to execute the method for automatically controlling the water level of a condenser hot well of a thermal power unit as described in Example 1;

[0160] The execution mechanism is connected to the data processing module and is used to receive and execute corresponding operation instructions.

[0161] like Figure 6 The figure shows the thermal system leakage and condenser hot well water replenishment diagram of the thermal power unit, which includes the access of the data acquisition module, including:

[0162] The multi-channel ultrasonic flowmeter 14 is provided on the water supply channel behind the water supply pump 12 and is used to collect the desalted water supply flow rate of the hot well in real time and obtain the desalted water supply flow rate data;

[0163] Hot well water level gauge 15, used to collect the water level of hot well 1 in real time and obtain the condenser hot well water level data;

[0164] The deaerator water tank water level gauge 16 is used to collect the water level of the deaerator water tank 11 in real time and obtain the deaerator water tank water level data;

[0165] The hot well pressure transmitter 17 is used to collect the hot well pressure in real time and obtain the hot well pressure data;

[0166] The deaerator pressure transmitter 18 is used to collect the deaerator water tank pressure in real time and obtain the deaerator water tank pressure data.

[0167] Specifically, the multi-channel ultrasonic flowmeter has a measurement error of less than ±0.3% and a range ratio higher than 100:1, which can meet the needs of accurate measurement of the entire range within a large flow range.

[0168] Example 4

[0169] This embodiment provides a computer-readable storage medium storing a computer program. When the computer program is executed, the method for automatically controlling the water level of a condenser hot well of a thermal power unit described in Example 1 is implemented.

[0170] Those skilled in the art will appreciate that the embodiments of the present application may be provided as methods, systems, or computer program products. Therefore, the present application may take the form of an entirely hardware embodiment, an entirely software embodiment, or an embodiment combining software and hardware. Furthermore, the present application may take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to magnetic disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0171] The present application is described with reference to the flowcharts and / or block diagrams of the methods, devices (systems), and computer program products according to the embodiments of the present application. It should be understood that each process and / or box in the flowchart and / or block diagram, as well as the combination of processes and / or boxes in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to produce a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 a process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0172] These computer program instructions may also be stored in a computer readable memory that can direct a computer or other programmable data processing device to work in a specific manner, so that the instructions stored in the computer readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 a process or multiple processes and / or boxes Figure 1 The function specified in one or more boxes.

[0173] The embodiments of the present invention are described above in conjunction with the accompanying drawings, but the present invention is not limited to the above-mentioned specific implementation methods. The above-mentioned specific implementation methods are merely illustrative and not restrictive. Under the guidance of the present invention, ordinary technicians in this field can also make many forms without departing from the scope of protection of the purpose of the present invention and the claims, which are all protected by the present invention.

Claims

1. A method for automatically controlling the water level of a condenser hot well of a thermal power unit, characterized in that: include: Obtaining comprehensive data on the hot well water level control of the thermal power unit, the comprehensive data on the hot well water level control including: condenser hot well water level data, deaerator water tank water level data, hot well desalted water replenishment flow data, deaerator water tank pressure data, and hot well pressure data; Calculate and correct the hot well water level based on the comprehensive data of hot well water level control of thermal power units; Based on five threshold intervals formed by four control thresholds set from low to high, the threshold interval in which the water level of the corrected hot well is located is determined, and an interval determination result is obtained; Based on the interval judgment results, corresponding operation instructions are issued to the actuator, thereby realizing automatic control of the hot well water level.

2. The method for automatically controlling the water level of the condenser hot well of a thermal power unit according to claim 1, characterized in that: The method of calculating and correcting the hot well water level according to the comprehensive data of hot well water level control of the thermal power unit includes: Get the water volume setting value of the deaerator tank; Based on the condenser hot well water level data, the hot well water level at the current moment is obtained; Based on the deaerator water tank water level data, the current deaerator water tank water level is obtained; Calculate the water volume of the deaerator water tank at the current moment according to the water level of the deaerator water tank at the current moment, the known length of the deaerator water tank, the intercept and radius of the head; Calculate the density of hot well water and deaerator tank water by combining the IAPWS-IF97 water vapor property formula, hot well pressure data, and deaerator tank pressure data. Based on the known length and width of the hot well cross section, the water density of the deaerator water tank, the hot well water density, the current hot well water level, the deaerator water tank water volume setting value, and the current deaerator water tank water volume, the corrected hot well water level is calculated using the following formula: ； Where, Indicates the corrected hot well water level; Indicates the hot well water level at the current moment; Indicates the water volume setting value of the deaerator water tank; Indicates the water density of the deaerator tank; Indicates the water volume of the deaerator tank at the current moment; represents the water density of the hot well; M and N represent the length and width of the hot well cross section, respectively.

3. The method for automatically controlling the water level of the condenser hot well of a thermal power unit according to claim 1, characterized in that: The five threshold intervals formed by the four control thresholds set from low to high are used to determine the threshold interval in which the water level of the corrected hot well is located, and obtain the interval determination result, including: Get the four control thresholds that have been set. The four control thresholds from low to high are: H1, H2, H4 and H5; Based on the four control thresholds, five threshold intervals are formed: , , , and ; The threshold range of the corrected hot well water level is determined, thereby obtaining an interval determination result.

4. The method for automatically controlling the water level of the condenser hot well of a thermal power unit according to claim 1, characterized in that: The step of issuing a corresponding operation instruction to the execution mechanism based on the interval judgment result includes: When the corrected hot well water level is When the water level in the hot well is lowered to H4, a high-level alarm signal and a first operation instruction are issued; the first operation instruction includes: closing the water supply pump, closing the water supply regulating valve, opening the low-pressure heater drain valve, and actively lowering the hot well water level until the corrected hot well water level is lowered to H4; When the corrected hot well water level is When the second operation instruction is issued, the second operation instruction includes: closing the water supply pump and the water supply regulating valve; When the corrected hot well water level is When the water supply is full, a third operation instruction is issued; the third operation instruction includes: closing the water supply pump, and adjusting the opening of the water supply regulating valve to control the water supply flow rate, so that the water supply flow rate is equal to the leakage flow rate within the previous first preset time interval; When the corrected hot well water level is When the water level in the hot well reaches the middle water level, the water level in the hot well reaches the middle water level. ... ; Among them, for the correction of hot well water level During the water replenishment process, when the corrected hot well water level reaches The third operation instruction is not sent during the interval. When the corrected hot well water level is When the water level in the hot well reaches H3, a low level alarm signal and a fifth operation instruction are issued; the fifth operation instruction includes: starting the water supply pump and adjusting the opening of the water supply regulating valve to 100% to supply water until the water level in the hot well reaches H3; wherein, during the water supply process when the water level in the hot well is lower than H1, when the water level in the hot well reaches The third operation instruction and the fourth operation instruction are not sent during the interval.

5. The method for automatically controlling the water level of the condenser hot well of a thermal power unit according to claim 4, characterized in that: The calculation process of the leakage flow rate within the previous first preset time interval includes: Based on the hot well desalted water replenishment flow rate data, the average replenishment flow rate at the start and end time points of the previous first preset time interval is obtained; Calculating the hot well equivalent flow rate for a previous first preset time interval based on the condenser hot well water level data, the known length and width of the hot well cross section, the hot well pressure data, and the first preset time interval; Calculate the deaerator tank equivalent flow rate for a current first preset time interval based on the deaerator tank water level data, the known deaerator tank length, the head intercept and radius, the deaerator tank pressure data, and the first preset time interval; The average water replenishment flow, the hot well equivalent flow and the deaerator water tank equivalent flow in the previous first preset time interval are added together to obtain the leakage flow in the previous first preset time interval.

6. The method for automatically controlling the water level of the condenser hot well of a thermal power unit according to claim 5, characterized in that: The step of calculating the hot well equivalent flow rate during a previous first preset time interval based on the condenser hot well water level data, the known length and width of the hot well cross section, the hot well pressure data, and the first preset time interval includes: Based on the condenser hot well water level data, the hot well water level at the start and end time points of the previous first preset time interval is obtained; Calculate the volume of the hot well water at the start and end time points of the previous first preset time interval based on the hot well water levels at the start and end time points of the previous first preset time interval and the known length and width of the hot well cross section; Using the IAPWS-IF97 water vapor property formula and hot well pressure data, calculate the hot well water density; Calculate the hot well equivalent flow rate for the previous first preset time interval by combining the first preset time interval, the hot well water level and hot well water volume at the start and end time points of the previous first preset time interval, and the hot well water density; The calculation formula of the hot well equivalent flow rate in the previous first preset time interval is expressed as: ； Where, Indicates the hot well equivalent flow rate during the previous first preset time interval; Respectively represent the hot well water volume at the start and end time points of the previous first preset time interval; represents a first preset time interval; Represents the density of hot well water.

7. The method for automatically controlling the water level of the condenser hot well of a thermal power unit according to claim 5, characterized in that: The step of calculating the deaerator water tank equivalent flow rate for a current first preset time interval based on the deaerator water tank water level data, the known deaerator water tank length, the head intercept and radius, the deaerator water tank pressure data, and the first preset time interval includes: Based on the deaerator water tank water level data, the deaerator water tank water level at the start and end time points of the previous first preset time interval is obtained; Calculate the water volume of the deaerator water tank at the start and end time points of the previous first preset time interval based on the water level of the deaerator water tank at the start and end time points of the previous first preset time interval, and the known length, head intercept, and radius of the deaerator water tank; Calculate the water density in the deaerator tank using the IAPWS - IF97 water vapor property formula and the deaerator tank pressure data; Calculate the equivalent flow rate of the deaerator water tank for the previous first preset time interval by combining the first preset time interval, the water volume of the deaerator water tank at the start and end time points of the previous first preset time interval, and the water density of the deaerator water tank; The calculation formula of the deaerator water tank equivalent flow rate at the previous first preset time interval is expressed as: ； Where, Indicates the deaerator water tank equivalent flow rate during the previous first preset time interval; Respectively represent the water volume of the deaerator tank at the start and end time points of the previous first preset time interval; Indicates a time interval; Indicates the water density of the deaerator tank.

8. The method for automatically controlling the water level of the condenser hot well of a thermal power unit according to claim 5, characterized in that: The calculation formula for the flow rate corresponding to the water level from the corrected hot well water level to the medium water level holding value within the second preset time interval is: ； Where, Indicates the flow rate corresponding to the water level of the corrected hot well reaching the medium water level holding value within the second preset time interval; Indicates the hot well water volume corresponding to the hot well water level when the hot well water level is the medium water level maintenance value H3; Indicates the hot well water volume corresponding to the corrected hot well water level; Indicates the second preset time interval.

9. An automatic control system for the water level of the condenser hot well of a thermal power unit, characterized in that: include: Data acquisition module, used to collect comprehensive data on thermal well water level control of thermal power units; A data processing module connected to the data acquisition module, configured to execute the method for automatically controlling the water level of a condenser hot well of a thermal power unit according to any one of claims 1 to 8; The execution mechanism is connected to the data processing module and is used to receive and execute corresponding operation instructions.

10. The method for automatically controlling the water level of the condenser hot well of a thermal power unit according to claim 9, characterized in that: The data acquisition module includes: Multi-channel ultrasonic flowmeter is used to collect the desalted water replenishment flow rate of hot wells in real time and obtain the desalted water replenishment flow rate data; Hot well water level gauge, used to collect hot well water level in real time and obtain condenser hot well water level data; Deaerator water tank water level gauge, used to collect the deaerator water tank water level in real time and obtain the deaerator water tank water level data; Hot well pressure transmitter, used to collect hot well pressure in real time and obtain hot well pressure data; The deaerator pressure transmitter is used to collect the deaerator water tank pressure in real time and obtain the deaerator water tank pressure data.

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