A rubber ball cleaning control method and system based on real-time monitoring of condenser performance

Abstract

The present invention discloses a rubber ball cleaning control method and system based on real-time monitoring of condenser performance, including real-time collection of measuring point data through measuring points of a power plant DCS system, wherein the measuring point data includes flow data, pressure data and temperature data; according to the measuring point data, the condenser operation cleanliness coefficient and condenser terminal difference are obtained, and according to the unit load rate and the pressure data, the condenser vacuum tightness index is obtained; the working condition of the condenser is judged, and if the working condition is a pure condensation condition, the flushing frequency of the rubber ball is controlled according to the condenser operation cleanliness coefficient, the condenser terminal difference and the condenser vacuum tightness index; if the working condition is a heating condition, the flushing frequency of the rubber ball is controlled according to the condenser operation cleanliness coefficient. The present invention can improve the economy of condenser operation, save plant electricity consumption, improve the utilization efficiency and flushing effect of the rubber ball system, and realize the cleanliness, high efficiency and energy saving of the condenser.

Description

Technical Field

[0001] The present invention relates to the technical field of rubber ball cleaning, and in particular to a rubber ball cleaning optimization control method and system for a cogeneration unit based on real-time monitoring of condenser performance. Background Art

[0002] The main function of the condenser of a thermal power unit is to cool the exhaust steam of the steam turbine into condensate, maintain the vacuum of the unit, and ensure the normal operation of the thermal cycle. The performance of the condenser will directly affect the exhaust pressure of the steam turbine, and have an important impact on the cycle thermal efficiency of the unit, power supply coal consumption, etc. In order to keep the inside of the condenser heat exchange tube bundle in a clean state, improve the vacuum of the unit, and thus improve the economic efficiency of the unit operation, it is necessary to flush the heat exchange tube bundle of the condenser through a rubber ball system. At present, the rubber ball system is commonly found in closed water cooling systems with cooling towers and open water cooling systems near rivers, lakes and seas.

[0003] However, in most power plants at present, the commissioning of the rubber ball system is somewhat blind, and most of them are commissioned regularly according to the main engine operation procedures. Some power plants use the end difference of the condenser as a reference, and perform rubber ball flushing when the end difference is high. Since the condenser end difference is an indirect indicator of the condenser performance and has a certain relationship with the ambient temperature, flow rate, etc., the rubber ball system has the problem of insufficient flushing and excessive flushing, causing the condenser to be dirty or waste electricity.

[0004] For cogeneration units, the heat supply in winter is very large, so the heat load entering the condenser is greatly reduced, and the required circulating water volume is reduced. At this time, the circulating water flow rate should be reduced as much as possible to operate. The flow rate is reduced, which increases the risk of condenser scaling and contamination. In addition, since the power plant has no real-time calculation indicators that directly reflect the contamination of the condenser, the circulating water flow rate is too large, resulting in an increase in the power consumption rate of the circulating pump, wasting a lot of electricity. Summary of the invention

[0005] In order to solve the above technical problems, the present invention provides a rubber ball cleaning optimization control method and system for a cogeneration unit based on real-time monitoring of condenser performance, which can solve the problems of poor condenser cleaning effect and increased power plant operating costs caused by blind commissioning of the rubber ball system, and can realize the intelligent commissioning of the condenser rubber ball system to achieve the purpose of cleaning, high efficiency and energy saving of the condenser.

[0006] In a first aspect, the present invention provides a condenser performance real-time monitoring based condenser cleaning control method, the method comprising:

[0007] Collecting measurement point data in real time through the measurement points of the power plant DCS system, the measurement point data including flow data, pressure data and temperature data;

[0008] According to the measuring point data, the condenser operation cleanliness coefficient and the condenser terminal difference are obtained, and according to the unit load rate and the pressure data, the condenser vacuum tightness index is obtained;

[0009] Determine the working condition of the condenser. If the working condition is a pure condensing condition, control the flushing frequency of the rubber ball according to the condenser operation cleanliness coefficient, the condenser end difference and the condenser vacuum tightness index;

[0010] If the working condition is a heating working condition, the flushing frequency of the rubber ball is controlled according to the condenser operation cleaning coefficient.

[0011] Furthermore, the step of obtaining the condenser operation cleanliness coefficient and the condenser terminal difference according to the measuring point data includes:

[0012] Based on the collected flow data and temperature data, the condenser heat load and heat transfer coefficient are calculated;

[0013] According to the heat transfer standard, the overall heat transfer coefficient is calculated;

[0014] Obtaining a condenser operation cleanliness coefficient according to the condenser heat load, the heat transfer coefficient and the overall heat transfer coefficient;

[0015] Based on the collected temperature data, the condenser terminal difference is calculated.

[0016] Furthermore, the condenser heat load is calculated using the following formula:

[0017] Q=G w ×C w ×(t w2 -t w1 )

[0018] In the formula, G w is the circulating water flow rate, C w is the specific heat capacity of circulating water, t w2 is the outlet temperature of the condenser circulating water, t w1 is the condenser circulating water inlet temperature;

[0019] The heat transfer coefficient is calculated using the following formula:

[0020]

[0021] Where A is the total heat transfer area of ​​the condenser tube bundle, ΔT m is the logarithmic mean temperature difference;

[0022] The overall heat transfer coefficient is calculated using the following formula:

[0023] U=U1×F W ×F M×C D

[0024] Where U1 is the basic heat transfer coefficient, F W is the circulating water temperature correction coefficient, F M is the correction factor for the condenser cooling tube material and wall thickness, C D Design cleanliness factor for condenser;

[0025] The condenser operation cleanliness factor is calculated using the following formula:

[0026]

[0027] The condenser end difference is calculated using the following formula:

[0028] δt=t s -t w2

[0029] In the formula, t s is the saturation temperature corresponding to the condenser exhaust pressure.

[0030] Furthermore, the step of obtaining the condenser vacuum tightness index according to the unit load rate and the pressure data includes:

[0031] Calculate the unit load rate of the condenser, and determine whether the unit load rate is less than the rated load threshold, if so, calculate the vacuum drop rate according to the first rate expression, if not, calculate the vacuum drop rate according to the second rate expression;

[0032] According to the preset conditions, after the vacuum drop rate is cyclically calculated, the vacuum drop rate is averaged to obtain an average vacuum drop rate;

[0033] The average vacuum drop rate is used as an indicator of the vacuum tightness of the condenser.

[0034] Furthermore, the first rate expression is calculated using the following formula:

[0035] k=(p2-p1) / T·(P / XPe)

[0036] In the formula, k is the vacuum drop rate, p1 is the vacuum value of the unit when recording starts, p2 is the vacuum value of the unit when recording ends, T is the sampling time, P is the average load of the unit during the sampling period, Pe is the rated load of the unit, and XPe is the rated load threshold;

[0037] The second rate expression is calculated using the following formula:

[0038] k=(p2-p1) / T

[0039] The condenser vacuum tightness index is calculated using the following formula:

[0040]

[0041] Where K is the vacuum tightness index of the condenser, k i is the vacuum drop rate obtained by the i-th calculation, and n is the number of calculations of the vacuum drop rate.

[0042] Furthermore, the preset condition is an operating condition that meets the load requirement within a predetermined time, and the load requirement is that the load change rate of the unit does not exceed a change threshold.

[0043] Furthermore, the step of judging the working condition of the condenser, if the working condition is a pure condensing condition, controlling the flushing frequency of the rubber ball according to the condenser operation cleanliness coefficient, the condenser end difference and the condenser vacuum tightness index includes:

[0044] Taking the difference between the condenser vacuum tightness index and the vacuum tightness threshold as the first difference, and taking the difference between the condenser terminal difference and the terminal difference threshold as the second difference;

[0045] If the first difference and the second difference are both less than or equal to zero, the condenser operation cleanliness coefficient is compared with a coefficient threshold, wherein the coefficient threshold includes a first coefficient threshold, a second coefficient threshold and a third coefficient threshold;

[0046] If the condenser operation cleanliness coefficient is less than or equal to the first coefficient threshold, the rubber ball is flushed according to the first flushing frequency; if the condenser operation cleanliness coefficient is greater than the first coefficient threshold and less than the second coefficient threshold, the rubber ball is flushed according to the third flushing frequency; if the condenser operation cleanliness coefficient is greater than or equal to the second coefficient threshold, the rubber ball is no longer flushed;

[0047] If the first difference is greater than zero and the second difference is less than or equal to zero, the condenser operation cleanliness coefficient is compared with the third coefficient threshold value; if the condenser operation cleanliness coefficient is less than the third coefficient threshold value, the rubber ball is flushed according to the first flushing frequency; if the condenser operation cleanliness coefficient is greater than or equal to the third coefficient threshold value, the rubber ball is no longer flushed;

[0048] If the first difference is less than or equal to zero and the second difference is greater than zero, the condenser operation cleanliness coefficient is compared with the second coefficient threshold value; if the condenser operation cleanliness coefficient is less than the second coefficient threshold value, the rubber ball is flushed according to the second flushing frequency; if it is greater than or equal to the second coefficient threshold value, the rubber ball is no longer flushed;

[0049] If the first difference and the second difference are both greater than zero, the condenser operating cleanliness coefficient is compared with the first coefficient threshold; if the condenser operating cleanliness coefficient is less than the first coefficient threshold, the rubber ball is flushed according to the second flushing frequency; if the condenser operating cleanliness coefficient is greater than or equal to the first coefficient threshold, the rubber ball is no longer flushed.

[0050] Furthermore, if the working condition is a heating working condition, the step of controlling the flushing frequency of the rubber ball according to the condenser operation cleaning coefficient includes:

[0051] The condenser operation cleanliness coefficient is compared with the third coefficient threshold. If the condenser operation cleanliness coefficient is less than the third coefficient threshold, the rubber ball is flushed according to the second flushing frequency. If the condenser operation cleanliness coefficient is greater than or equal to the third coefficient threshold, the rubber ball is no longer flushed.

[0052] In a second aspect, the present invention provides a condenser performance real-time monitoring based condenser ball cleaning control system, the system comprising:

[0053] A data acquisition module is used to collect measurement point data in real time through the measurement points of the power plant DCS system, wherein the measurement point data includes flow data, pressure data and temperature data;

[0054] A data processing module, used to obtain the condenser operation cleanliness coefficient and the condenser terminal difference according to the measuring point data, and to obtain the condenser vacuum tightness index according to the unit load rate and the pressure data;

[0055] The rubber ball flushing control module is used to determine the operating condition of the condenser. If the operating condition is a pure condensing condition, the flushing frequency of the rubber ball is controlled according to the condenser operating cleanliness coefficient, the condenser end difference and the condenser vacuum tightness index; if the operating condition is a heating condition, the flushing frequency of the rubber ball is controlled according to the condenser operating cleanliness coefficient.

[0056] The present invention provides a condenser performance real-time monitoring based condenser cleaning control method and system. The method replaces the traditional condenser system periodic operation mode, and the present invention can realize the intelligent operation of the condenser system, thereby maintaining the clean and efficient operation of the condenser, reducing the coal consumption of the unit power supply, and achieving energy saving and carbon reduction. BRIEF DESCRIPTION OF THE DRAWINGS

[0057] Figure 1 It is a schematic flow chart of a rubber ball cleaning control method provided by an embodiment of the present invention;

[0058] Figure 2It is a structural schematic diagram of a rubber ball cleaning control system provided by an embodiment of the present invention;

[0059] Figure 3 It is a system schematic diagram of a rubber ball cleaning control system provided in an embodiment of the present invention. DETAILED DESCRIPTION

[0060] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0061] See also Figure 1 The first embodiment of the present invention proposes a condenser performance real-time monitoring based condenser ball cleaning control method, comprising steps S10 to S40:

[0062] Step S10: collecting measurement point data in real time through the measurement points of the power plant DCS system, wherein the measurement point data includes flow data, pressure data and temperature data.

[0063] Step S20, obtaining the condenser operation cleanliness coefficient and the condenser terminal difference according to the measuring point data, and obtaining the condenser vacuum tightness index according to the unit load rate and the pressure data.

[0064] Due to the problems existing in the existing operation scheme of the rubber ball system of thermal power units, such as blind commissioning of the rubber balls, poor cleaning effect and increased operation costs, the present invention realizes the intelligent commissioning of the rubber balls by real-time monitoring of the performance parameters of the condenser. At the same time, in order to reduce the operation cost, the present invention uses the existing measuring points of the DCS system of the power plant to measure the relevant data, and on this basis, only a fixed ultrasonic flowmeter is added to the circulating water inlet or outlet pipeline to measure the circulating water flow entering the condenser in real time, and the relevant indicators are calculated based on the collected data.

[0065] The measuring point data in this embodiment mainly include flow data collected by the ultrasonic flow meter, and pressure data and temperature data collected by the original pressure measuring points and temperature measuring points. At the same time, a high-precision vacuum pressure gauge is added to measure the vacuum value of the unit.

[0066] The control method of this embodiment mainly performs logical judgment based on three indicators to control the commissioning and flushing of the rubber ball. The three indicators include the condenser operation cleanliness coefficient, the condenser terminal difference and the condenser vacuum tightness. The reason for selecting these three indicators for judgment is that the condenser operation cleanliness coefficient can intuitively indicate the cleanliness of the condenser, and the condenser vacuum tightness is closely related to the cleanliness coefficient. When the vacuum tightness changes, the cleanliness coefficient will also change accordingly. In addition, the condenser terminal difference can also indicate the cleanliness of the condenser cooling pipe. If the condenser terminal difference is much higher than the terminal difference should be, it means that the condenser cooling pipe may be dirty. Therefore, the present invention incorporates all three indicators into the judgment process at the same time, so that the judgment result is more scientific and accurate.

[0067] In order to obtain the above three indicators in real time, the present invention establishes a relevant calculation model to obtain the corresponding indicators, wherein the calculation steps of the condenser operation cleanliness coefficient and the condenser end difference are as follows:

[0068] Step S201, calculating the heat load and heat transfer coefficient of the condenser according to the collected flow data and temperature data;

[0069] Step S202, calculating the overall heat transfer coefficient according to the heat transfer standard;

[0070] Step S203, obtaining a condenser operation cleanliness coefficient according to the condenser heat load, the heat transfer coefficient and the overall heat transfer coefficient;

[0071] Step S204: Calculate the condenser terminal difference based on the collected temperature data.

[0072] In this embodiment, a condenser online performance calculation model is established to obtain the condenser operation cleanliness coefficient and condenser terminal difference in real time. The calculation process of the performance calculation model is:

[0073] The condenser heat load is calculated using the following formula:

[0074] Q=G w ×C w ×(t w2 -t w1 )

[0075] In the formula, G w is the circulating water flow rate, C w is the specific heat capacity of circulating water, t w2 is the outlet temperature of the condenser circulating water, t w1 is the condenser circulating water inlet temperature;

[0076] The heat transfer coefficient is calculated using the following formula:

[0077]

[0078] Where A is the total heat transfer area of ​​the condenser tube bundle, ΔT m is the logarithmic mean temperature difference;

[0079] The overall heat transfer coefficient is calculated using the following formula:

[0080] U=U1×F W ×F M ×C D

[0081] Where U1 is the basic heat transfer coefficient, F W is the circulating water temperature correction coefficient, F M is the correction factor for the condenser cooling tube material and wall thickness, C D Design cleanliness factor for condenser;

[0082] The condenser operation cleanliness factor is calculated using the following formula:

[0083]

[0084] The condenser end difference is calculated using the following formula:

[0085] δt=t s -t w2

[0086] In the formula, t s is the saturation temperature corresponding to the condenser exhaust pressure.

[0087] For the condenser vacuum tightness index, in this embodiment, the index is obtained by establishing an online simplified calculation model for the condenser vacuum tightness. In this model, the unit AGC load rate, the vacuum pump start-stop control signal, and the vacuum value measured by the high-precision vacuum meter are used as PLC input parameters. And the relevant algorithm is set in the background to judge the data, that is, when the unit load is greater than 50% load and has been running stably for more than half an hour, through logical judgment, the vacuum pump shutdown signal is sent, and recording starts after three minutes. The data is continuously recorded for 5 minutes, and the rate of decrease of the unit vacuum within 5 minutes is calculated, and then the vacuum pump is restarted. It should be noted that the specific numerical values ​​in this embodiment are only used to illustrate the implementation process of this method. The numerical values ​​can be flexibly set according to actual conditions. There are no too many specific restrictions here, and they will not be repeated later.

[0088] The specific calculation steps of vacuum tightness are as follows:

[0089] Step S205, calculating the unit load rate of the condenser, and determining whether the unit load rate is less than the rated load threshold, if so, calculating the vacuum drop rate according to the first rate expression, if not, calculating the vacuum drop rate according to the second rate expression;

[0090] Step S206, after cyclically calculating the vacuum drop rate according to preset conditions, average value of the vacuum drop rate is calculated to obtain an average vacuum drop rate;

[0091] Step S207: taking the average vacuum drop rate as a condenser vacuum tightness index.

[0092] In this embodiment, a rated load threshold is set, and preferably, the threshold can be set to 80% of the rated load, that is, if the rated load of the unit is 1000MW, the rated load threshold is 800MW. The reason for setting this threshold is that the strict vacuum tightness test in the industry currently requires the unit load to be above 80%. Considering that the overall unit load rate is currently low, in order to ensure that the vacuum tightness data can be obtained every day, this embodiment adds a calculation step of the tightness algorithm when the load is less than 80% in the simplified algorithm.

[0093] Therefore, the calculation of vacuum tightness in this embodiment is divided into two parts according to the unit load rate. When the unit load rate is less than the rated load threshold, the calculation formula of the vacuum drop rate is:

[0094] k=(p2-p1) / T·(P / XPe)

[0095] In the formula, k is the vacuum drop rate, p1 is the vacuum value of the unit when recording starts, p2 is the vacuum value of the unit when recording ends, T is the sampling time, P is the average load of the unit during the sampling period, Pe is the rated load of the unit, and XPe is the rated load threshold;

[0096] When the unit load rate is greater than or equal to the rated load threshold, the calculation formula for the vacuum drop rate is:

[0097] k=(p2-p1) / T

[0098] Since the unit load rate cannot be guaranteed not to change dramatically within five minutes of recording, for example, the load change rate may exceed 10% of the rated load rate, in order to further ensure the accuracy of the data, this embodiment adopts a multiple-repetition method to calculate the vacuum drop rate, that is, the interval time of each calculation is not less than 30 minutes, and it is repeated at most four times every 24 hours, and the calculated data is then eliminated according to the fluctuation of the change rate, and finally the vacuum drop rate under the working conditions that meet the load requirements is averaged, and the average vacuum drop rate is recorded as the simplified online unit vacuum tightness within 24 hours.

[0099] Through the above method, the control parameters of the rubber ball system commissioning measurement are obtained, and then the commissioning of the rubber ball system is controlled according to these three important indicators.

[0100] Step S30, judging the working condition of the condenser, if the working condition is a pure condensing condition, controlling the flushing frequency of the rubber ball according to the condenser operation cleanliness coefficient, the condenser end difference and the condenser vacuum tightness index.

[0101] The operating conditions of the condenser under different circumstances can be divided into pure condensing conditions and heating conditions. In order to make the flushing of the rubber ball more in line with the actual situation, the control logic of the rubber ball system under different conditions must be different. Under the pure condensing condition, the control logic of the rubber ball is as follows:

[0102] Step S301, taking the difference between the condenser vacuum tightness index and the vacuum tightness threshold as the first difference, and taking the difference between the condenser terminal difference and the terminal difference threshold as the second difference;

[0103] Step S302, if the first difference and the second difference are both less than or equal to zero, comparing the condenser operation cleanliness coefficient with a coefficient threshold, wherein the coefficient threshold includes a first coefficient threshold, a second coefficient threshold and a third coefficient threshold;

[0104] Step S303: if the condenser operation cleanliness coefficient is less than the first coefficient threshold, the rubber ball is flushed according to the first flushing frequency; if the condenser operation cleanliness coefficient is greater than or equal to the first coefficient threshold and less than the second coefficient threshold, the rubber ball is flushed according to the third flushing frequency; if the condenser operation cleanliness coefficient is greater than or equal to the second coefficient threshold, the rubber ball is no longer flushed;

[0105] Step S304: if the first difference is greater than zero and the second difference is less than or equal to zero, the condenser operation cleanliness coefficient is compared with the third coefficient threshold value; if the condenser operation cleanliness coefficient is less than the third coefficient threshold value, the rubber ball is flushed according to the first flushing frequency; if the condenser operation cleanliness coefficient is greater than or equal to the third coefficient threshold value, the rubber ball is no longer flushed;

[0106] Step S305, if the first difference is less than or equal to zero and the second difference is greater than zero, the condenser operation cleanliness coefficient is compared with the second coefficient threshold value, if the condenser operation cleanliness coefficient is less than the second coefficient threshold value, the rubber ball is flushed according to the second flushing frequency, if it is greater than or equal to the second coefficient threshold value, the rubber ball is no longer flushed;

[0107] Step S306: If both the first difference and the second difference are greater than zero, compare the operating cleaning coefficient of the condenser with the first coefficient threshold. If the operating cleaning coefficient of the condenser is less than the first coefficient threshold, flush the rubber balls according to the second flushing frequency. If the operating cleaning coefficient of the condenser is greater than or equal to the first coefficient threshold, stop flushing the rubber balls.

[0108] To better illustrate the logical judgment under the pure condensing condition, the threshold parameters used are first explained. In this embodiment, corresponding threshold parameters are set for three indicators, including the vacuum tightness threshold k1, the terminal temperature difference threshold t1, and the coefficient threshold m. The coefficient threshold m includes the first coefficient threshold m1, the second coefficient threshold m2, and the third coefficient threshold m3. Different flushing frequencies are preset for the operation of the rubber balls, including the first flushing frequency f1, the second flushing frequency f2, and the third flushing frequency f3. And m3 < m1 < m2, and f3 < f1 < f2. To better illustrate the control logic of the present invention, in this embodiment, it is assumed that k1 = 100, t1 = 5, m3 = 0.75, m1 = 0.8, and m2 = 0.85.

[0109] According to different threshold conditions, the following four situations can be obtained:

[0110] ① Vacuum tightness ≤ k1 Pa / min, condenser terminal temperature difference ≤ t1 °C

[0111] If the cleaning coefficient ≤ m1, immediately put the rubber ball cleaning system into operation and flush the condenser system. At this time, the flushing frequency of the rubber balls is set to f1;

[0112] If m1 < cleaning coefficient < m2, the overall operating state of the condenser is basically good. Reduce the operating frequency of the rubber ball system and perform regular flushing with the operating frequency f3;

[0113] If m2 < cleaning coefficient, it indicates that the overall operating state of the condenser is good. Therefore, the operation of the rubber balls for flushing will no longer be triggered to avoid waste of electric energy.

[0114] ② Vacuum tightness > k1 Pa / min, condenser terminal temperature difference ≤ t1 °C

[0115] If the cleaning coefficient < m3, immediately put the rubber ball cleaning system into operation and flush the condenser system. At this time, the flushing frequency of the rubber balls is set to f1;

[0116] If the cleaning coefficient ≥ m3, the operation of the rubber balls for flushing will no longer be triggered.

[0117] ③ Vacuum tightness ≤ k1 Pa / min, condenser terminal temperature difference > t1 °C

[0118] If the cleaning coefficient is less than m2, the rubber ball cleaning system is immediately put into operation to flush the condenser system. At this time, the flushing frequency of the rubber ball is set to f2;

[0119] If the cleaning coefficient is ≥m2, the rubber ball will no longer be triggered for cleaning.

[0120] ④ Vacuum tightness>k1Pa / min, condenser end difference>t1℃

[0121] If the cleaning coefficient is less than m1, the rubber ball cleaning system is immediately put into operation to flush the condenser system. At this time, the flushing frequency of the rubber ball is set to f2;

[0122] If the cleaning coefficient is ≥m1, the rubber ball will no longer be triggered for cleaning.

[0123] Step S40: If the working condition is a heating working condition, the flushing frequency of the rubber ball is controlled according to the condenser operation cleaning coefficient.

[0124] Under heating conditions, the required circulating water flow is greatly reduced and the flow rate is reduced, which increases the possibility of condenser fouling. The low inlet water temperature in winter leads to an increase in the condenser end. Therefore, regardless of the vacuum tightness and condenser end difference data, under heating conditions, only the condenser cleanliness factor is used as the only indicator to control the commissioning of the rubber ball system, that is:

[0125] If the cleaning coefficient is less than m3, the rubber ball cleaning system is immediately put into operation to flush the condenser system. At this time, the flushing frequency of the rubber ball is set to f2;

[0126] If the cleaning coefficient is ≥m3, the rubber ball will no longer be triggered for cleaning.

[0127] The above judgment logic is written into the PLC memory, and the on-site input signal and the controlled actuator are connected to the input end of the input module and the output end of the output module respectively. Then the PLC working mode is selected as the running working mode, and the subsequent work is completed by the PLC according to the user program, that is, the automatic intelligent flushing of the rubber ball under different working conditions is realized, thereby improving the cleaning efficiency of the condenser and reducing the power consumption.

[0128] The present embodiment provides a rubber ball cleaning control method based on real-time monitoring of condenser performance. Compared with the problem of poor cold end operation due to blind commissioning of the rubber ball system of the condenser of the thermal power generator set in the traditional method, the present invention avoids the problem of not timely discovering the dirt of the condenser and not timely commissioning the rubber ball system for flushing, and avoids excessive cleaning of the condenser, reduces the risk of tube bundle wear, improves operating economy and saves power consumption of the power plant, and at the same time realizes intuitive monitoring of the operating status of the condenser, thereby guiding the safe and economical operation of the condenser. In addition, the present invention formulates a more scientific and reasonable rubber ball commissioning strategy, adopts PLC control mode, has strong compatibility, and further improves the utilization efficiency and flushing effect of the rubber ball system.

[0129] See also Figure 2 Based on the same inventive concept, the second embodiment of the present invention proposes a rubber ball cleaning control system based on real-time monitoring of condenser performance, comprising:

[0130] The data acquisition module 10 is used to collect the measurement point data in real time through the measurement points of the power plant DCS system, and the measurement point data includes flow data, pressure data and temperature data;

[0131] The data processing module 20 is used to obtain the condenser operation cleanliness coefficient and the condenser terminal difference according to the measuring point data, and to obtain the condenser vacuum tightness index according to the unit load rate and the pressure data;

[0132] The rubber ball flushing control module 30 is used to determine the operating condition of the condenser. If the operating condition is a pure condensing condition, the flushing frequency of the rubber ball is controlled according to the condenser operating cleanliness coefficient, the condenser end difference and the condenser vacuum tightness index; if the operating condition is a heating condition, the flushing frequency of the rubber ball is controlled according to the condenser operating cleanliness coefficient.

[0133] In order to more intuitively explain the structural relationship and operation process of the control system in this embodiment, please refer to Figure 3 The control system of this embodiment is to set an ultrasonic flow meter 11 on the circulating water inlet or outlet pipeline of the condenser 1, and collect relevant data at the existing pressure measuring point 12 and temperature measuring point 13. At the same time, the rubber ball system 2 in this system is controlled by PLC3 for operation.

[0134] This system uses an online ultrasonic flowmeter to measure the condenser circulating water flow in real time as one of the important input data for condenser performance calculation and heat load calculation. It solves the problem that the circulating water flow cannot be accurately measured and the calculation results are inaccurate due to the heat load calculated by steam flow and exhaust enthalpy. Other data use existing DCS measurement points to establish an online real-time performance calculation model for the condenser. The online data is used to propose a model for simplified online calculation of vacuum tightness, and the key indicator for judging condenser performance, namely the online vacuum tightness indicator, is obtained, providing key support for optimized control.

[0135] On the basis of the above model, a multi-dimensional, multi-condition segmented control strategy is formulated based on the real-time calculated condenser cleanliness coefficient, condenser end difference and vacuum tightness. A scientific, rigorous and comprehensive control judgment logic for the commissioning of the rubber ball system is formulated under different operating modes of pure condensation and heating. Automatic control is achieved through the PLC system, thereby realizing the intelligent commissioning of the rubber ball system. While maintaining the clean and efficient operation of the condenser, the present invention reduces the coal consumption of the unit for power supply, thereby achieving energy conservation and carbon reduction.

[0136] The technical features and technical effects of the colloid ball cleaning control system based on real-time monitoring of condenser performance proposed in the embodiment of the present invention are the same as those of the method proposed in the embodiment of the present invention, and will not be described in detail here. Each module in the above-mentioned colloid ball cleaning control system based on real-time monitoring of condenser performance can be implemented in whole or in part through software, hardware and a combination thereof. The above-mentioned modules can be embedded in or independent of the processor in the computer device in the form of hardware, or can be stored in the memory in the computer device in the form of software, so that the processor can call and execute the operations corresponding to the above modules.

[0137] In summary, an embodiment of the present invention proposes a rubber ball cleaning control method and system based on real-time monitoring of condenser performance. The method collects measurement point data in real time through the measurement points of the power plant DCS system, and the measurement point data includes flow data, pressure data and temperature data; according to the measurement point data, the condenser operation cleanliness coefficient and the condenser end difference are obtained, and according to the unit load rate and the pressure data, the condenser vacuum tightness index is obtained; the operating condition of the condenser is judged, and if the operating condition is a pure condensing condition, the flushing frequency of the rubber ball is controlled according to the condenser operation cleanliness coefficient, the condenser end difference and the condenser vacuum tightness index; if the operating condition is a heating condition, the flushing frequency of the rubber ball is controlled according to the condenser operation cleanliness coefficient. The present invention establishes a comprehensive cleaning evaluation index through the condenser cleaning coefficient, condenser terminal difference and vacuum tightness index, formulates a specific judgment logic for rubber ball operation, and realizes the intelligent operation of the condenser rubber ball system through PLC, thereby avoiding the problems of untimely and excessive cleaning of the condenser, improving the economy of condenser operation, and saving power consumption of power plants. In addition, the present invention can intuitively monitor the operating status of the condenser, cooperate with a scientific and reasonable rubber ball operation strategy, further improve the utilization efficiency and flushing effect of the rubber ball system, and realize the cleanliness, high efficiency and energy saving of the condenser.

[0138] Each embodiment in this specification is described in a progressive manner, and the same or similar parts of each embodiment can be directly referred to each other, and each embodiment focuses on the differences from other embodiments. In particular, for the system embodiment, since it is basically similar to the method embodiment, the description is relatively simple, and the relevant parts can be referred to the partial description of the method embodiment. It should be noted that the technical features of the above-mentioned embodiments can be combined arbitrarily. In order to make the description concise, all possible combinations of the technical features in the above-mentioned embodiments are not described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0139] The above-mentioned embodiments only express several preferred implementation modes of the present application, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the invention patent. It should be pointed out that, for ordinary technicians in the technical field, several improvements and substitutions can be made without departing from the technical principles of the present invention, and these improvements and substitutions should also be regarded as the protection scope of the present application. Therefore, the protection scope of the patent of the present application shall be based on the protection scope of the claims.

Claims

1. A condenser performance real-time monitoring based condenser ball cleaning control method, characterized in that: include: Collecting measurement point data in real time through the measurement points of the power plant DCS system, the measurement point data including flow data, pressure data and temperature data; According to the measuring point data, the condenser operation cleanliness coefficient and the condenser terminal difference are obtained, and according to the unit load rate and the pressure data, the condenser vacuum tightness index is obtained; Determine the working condition of the condenser. If the working condition is a pure condensing condition, control the flushing frequency of the rubber ball according to the condenser operation cleanliness coefficient, the condenser end difference and the condenser vacuum tightness index; If the working condition is a heating condition, the flushing frequency of the rubber ball is controlled according to the condenser operation cleanliness coefficient; Wherein, the flushing frequency includes a first flushing frequency, a second flushing frequency and a third flushing frequency, the first flushing frequency is greater than the third flushing frequency, and the first flushing frequency is less than the second flushing frequency; The step of judging the working condition of the condenser, if the working condition is a pure condensing condition, controlling the flushing frequency of the rubber ball according to the condenser operation cleanliness coefficient, the condenser end difference and the condenser vacuum tightness index comprises: Taking the difference between the condenser vacuum tightness index and the vacuum tightness threshold as the first difference, and taking the difference between the condenser terminal difference and the terminal difference threshold as the second difference; If the first difference and the second difference are both less than or equal to zero, the condenser operation cleanliness coefficient is compared with a coefficient threshold, wherein the coefficient threshold includes a first coefficient threshold, a second coefficient threshold and a third coefficient threshold; the first coefficient threshold is greater than the third coefficient threshold, and the first coefficient threshold is less than the second coefficient threshold; If the condenser operation cleanliness coefficient is less than or equal to the first coefficient threshold, the rubber ball is flushed according to the first flushing frequency; if the condenser operation cleanliness coefficient is greater than the first coefficient threshold and less than the second coefficient threshold, the rubber ball is flushed according to the third flushing frequency; if the condenser operation cleanliness coefficient is greater than or equal to the second coefficient threshold, the rubber ball is no longer flushed; If the first difference is greater than zero and the second difference is less than or equal to zero, the condenser operation cleanliness coefficient is compared with the third coefficient threshold value; if the condenser operation cleanliness coefficient is less than the third coefficient threshold value, the rubber ball is flushed according to the first flushing frequency; if the condenser operation cleanliness coefficient is greater than or equal to the third coefficient threshold value, the rubber ball is no longer flushed; If the first difference is less than or equal to zero and the second difference is greater than zero, the condenser operation cleanliness coefficient is compared with the second coefficient threshold value, if the condenser operation cleanliness coefficient is less than the second coefficient threshold value, the rubber ball is flushed according to the second flushing frequency, if it is greater than or equal to the second coefficient threshold value, the rubber ball is no longer flushed; If the first difference and the second difference are both greater than zero, the condenser operating cleanliness coefficient is compared with the first coefficient threshold; if the condenser operating cleanliness coefficient is less than the first coefficient threshold, the rubber ball is flushed according to the second flushing frequency; if the condenser operating cleanliness coefficient is greater than or equal to the first coefficient threshold, the rubber ball is no longer flushed.

2. The condenser performance real-time monitoring based condenser ball cleaning control method according to claim 1 is characterized in that: The step of obtaining the condenser operation cleanliness coefficient and the condenser terminal difference according to the measuring point data comprises: Based on the collected flow data and temperature data, the condenser heat load and heat transfer coefficient are calculated; According to the heat transfer standard, the overall heat transfer coefficient is calculated; Obtaining a condenser operation cleanliness coefficient according to the condenser heat load, the heat transfer coefficient and the overall heat transfer coefficient; Based on the collected temperature data, the condenser terminal difference is calculated.

3. The condenser performance real-time monitoring based condenser ball cleaning control method according to claim 2 is characterized in that: The condenser heat load is calculated using the following formula: Q=G w ×C w ×(t w2 -t w1 ) In the formula, G w is the circulating water flow rate, C w is the specific heat capacity of circulating water, t w2 is the outlet temperature of the condenser circulating water, t w1 is the condenser circulating water inlet temperature; The heat transfer coefficient is calculated using the following formula: Where A is the total heat transfer area of ​​the condenser tube bundle, ΔT m is the logarithmic mean temperature difference; The overall heat transfer coefficient is calculated using the following formula: U=U1×F W ×F M ×C D Where U1 is the basic heat transfer coefficient, F W is the circulating water temperature correction coefficient, F M is the correction factor for the condenser cooling tube material and wall thickness, C D Design cleanliness factor for condenser; The condenser operation cleanliness factor is calculated using the following formula: The condenser end difference is calculated using the following formula: δt=t s -t w2 Where, t s is the saturation temperature corresponding to the condenser exhaust pressure.

4. The condenser performance real-time monitoring and control method for cleaning condenser balls according to claim 1 is characterized in that: The step of obtaining the condenser vacuum tightness index according to the unit load rate and the pressure data comprises: Calculate the unit load rate of the condenser, and determine whether the unit load rate is less than the rated load threshold, if so, calculate the vacuum drop rate according to the first rate expression, if not, calculate the vacuum drop rate according to the second rate expression; According to the preset conditions, after the vacuum drop rate is cyclically calculated, the vacuum drop rate is averaged to obtain an average vacuum drop rate; The average vacuum drop rate is used as an indicator of the vacuum tightness of the condenser.

5. The condenser performance real-time monitoring based condenser ball cleaning control method according to claim 4 is characterized in that: The first rate expression is calculated using the following formula: k=(p2-p1) / T·(P / XPe) In the formula, k is the vacuum drop rate, p1 is the vacuum value of the unit when recording starts, p2 is the vacuum value of the unit when recording ends, T is the sampling time, P is the average load of the unit during the sampling period, Pe is the rated load of the unit, and XPe is the rated load threshold; The second rate expression is calculated using the following formula: k=(p2-p1) / T The condenser vacuum tightness index is calculated using the following formula: Where K is the vacuum tightness index of the condenser, k i is the vacuum drop rate obtained by the i-th calculation, and n is the number of calculations of the vacuum drop rate.

6. According to the condenser performance real-time monitoring based condenser ball cleaning control method of claim 4, the preset condition is the working condition that meets the load requirement within a predetermined time, and the load requirement is that the unit load change rate does not exceed the change threshold.

7. According to the condenser performance real-time monitoring based condenser cleaning control method of claim 1, if the working condition is a heating condition, the step of controlling the flushing frequency of the condenser according to the condenser operation cleaning coefficient comprises: The condenser operation cleanliness coefficient is compared with the third coefficient threshold. If the condenser operation cleanliness coefficient is less than the third coefficient threshold, the rubber ball is flushed according to the second flushing frequency. If the condenser operation cleanliness coefficient is greater than or equal to the third coefficient threshold, the rubber ball is no longer flushed.

8. A rubber ball cleaning control system based on real-time monitoring of condenser performance, characterized in that: include: A data acquisition module is used to collect measurement point data in real time through the measurement points of the power plant DCS system, wherein the measurement point data includes flow data, pressure data and temperature data; A data processing module, used to obtain the condenser operation cleanliness coefficient and the condenser terminal difference according to the measuring point data, and to obtain the condenser vacuum tightness index according to the unit load rate and the pressure data; A rubber ball flushing control module is used to judge the working condition of the condenser. If the working condition is a pure condensing condition, the flushing frequency of the rubber ball is controlled according to the condenser operation cleanliness coefficient, the condenser end difference and the condenser vacuum tightness index; if the working condition is a heating condition, the flushing frequency of the rubber ball is controlled according to the condenser operation cleanliness coefficient; Wherein, the flushing frequency includes a first flushing frequency, a second flushing frequency and a third flushing frequency, the first flushing frequency is greater than the third flushing frequency, and the first flushing frequency is less than the second flushing frequency; The step of judging the working condition of the condenser, if the working condition is a pure condensing condition, controlling the flushing frequency of the rubber ball according to the condenser operation cleanliness coefficient, the condenser end difference and the condenser vacuum tightness index comprises: Taking the difference between the condenser vacuum tightness index and the vacuum tightness threshold as the first difference, and taking the difference between the condenser terminal difference and the terminal difference threshold as the second difference; If the first difference and the second difference are both less than or equal to zero, the condenser operation cleanliness coefficient is compared with a coefficient threshold, wherein the coefficient threshold includes a first coefficient threshold, a second coefficient threshold and a third coefficient threshold; the first coefficient threshold is greater than the third coefficient threshold, and the first coefficient threshold is less than the second coefficient threshold; If the condenser operation cleanliness coefficient is less than or equal to the first coefficient threshold, the rubber ball is flushed according to the first flushing frequency; if the condenser operation cleanliness coefficient is greater than the first coefficient threshold and less than the second coefficient threshold, the rubber ball is flushed according to the third flushing frequency; if the condenser operation cleanliness coefficient is greater than or equal to the second coefficient threshold, the rubber ball is no longer flushed; If the first difference is greater than zero and the second difference is less than or equal to zero, the condenser operation cleanliness coefficient is compared with the third coefficient threshold value; if the condenser operation cleanliness coefficient is less than the third coefficient threshold value, the rubber ball is flushed according to the first flushing frequency; if the condenser operation cleanliness coefficient is greater than or equal to the third coefficient threshold value, the rubber ball is no longer flushed; If the first difference is less than or equal to zero and the second difference is greater than zero, the condenser operation cleanliness coefficient is compared with the second coefficient threshold value, if the condenser operation cleanliness coefficient is less than the second coefficient threshold value, the rubber ball is flushed according to the second flushing frequency, if it is greater than or equal to the second coefficient threshold value, the rubber ball is no longer flushed; If the first difference and the second difference are both greater than zero, the condenser operating cleanliness coefficient is compared with the first coefficient threshold; if the condenser operating cleanliness coefficient is less than the first coefficient threshold, the rubber ball is flushed according to the second flushing frequency; if the condenser operating cleanliness coefficient is greater than or equal to the first coefficient threshold, the rubber ball is no longer flushed.

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