Circulating water pump control method and system based on real-time power optimization

Abstract

A circulating water pump control method and system based on real-time power optimization. The control method comprises: collecting the real-time powers of electric boilers; on the basis of a set power of a coal-fired boiler and the collected real-time powers, determining control flow rates of water-supply circulating water pumps; according to the control flow rates, controlling the water-supply circulating water pumps to operate; after the real-time powers change, establishing an objective function with the objective of minimizing the sum of flow rate variations of the water-supply circulating water pumps; solving the objective function, so as to obtain regulated flow rates; and according to the regulated flow rates, controlling the water-supply circulating water pumps to operate. In the method, the circulating water pumps can quickly adapt to power changes, such that the boilers keep operating in an optimal state, thereby maximizing the energy utilization.

Description

A circulating water pump control method and system based on real-time power optimization TECHNICAL FIELD

[0001] The present application relates to the technical field of liquid pumps, in particular to a circulating water pump control method and system based on real-time power optimization. BACKGROUND

[0002] Central heating is a common heating method in winter, and the heating company inputs high-temperature medium, such as water or steam, into the primary network, exchanges heat at the heat exchange station, and then transmits the heat to the secondary network, and finally to the user's indoor. The heat source used by the heating company mainly has two kinds, one is the waste heat of the power plant, and the other is the heating of the boiler. The latter is the main heat source at present, and the boiler can heat the water in the primary network to about 130 degrees Celsius, and after heat exchange by the heat exchanger, the return water of the primary network is about 70 degrees Celsius. These return water is transported to the boiler again by the circulating water pump and heated again to realize the recycling of water.

[0003] Although the coal-fired boiler still accounts for a large proportion in all boilers at present, cleaner and more economical energy sources are also gradually applied to heating. These emerging energy sources have the advantages of renewable, low pollution and low cost, and the application of these energy sources is expected to reduce the cost of heating companies. However, after the addition of new energy sources, the use strategy of the existing coal-fired boiler needs to be adjusted, especially the state control of the circulating water pump. If the control strategy of the circulating water pump is selected incorrectly, the maximum value of the emerging energy source may not be realized, resulting in waste of energy.

[0004] SUMMARY

[0005] In view of the above existing problems, the present application is proposed.

[0006] Therefore, the present application provides a circulating water pump control method based on real-time power optimization, which can solve the problem of energy waste caused by incorrect selection of circulating water pump control strategy in the prior art.

[0007] To solve the above technical problems, the present application provides the following technical scheme, a circulating water pump control method based on real-time power optimization, comprising: collecting real-time power of a first electric boiler and a second electric boiler; determining a control flow according to a set power and the collected real-time power, and controlling the corresponding water supply circulating water pump to work in layers; when the real-time power changes, a target function is established with the minimum sum of the flow changes of the water supply circulating water pump as the target, and a constraint condition is set; a genetic algorithm is used to solve the target function to obtain the adjustment flow of the water supply circulating water pump; and the water supply circulating water pump is adjusted synchronously according to the obtained adjustment flow.

[0008] As a preferred scheme of the circulating water pump control method based on real-time power optimization, the real-time power of the first electric boiler and the second electric boiler is collected, including: a current transformer is connected in series in a power supply line of the electric boiler to measure the current in a non-intrusive manner, a voltage sensor is connected in parallel in the power supply line of the electric boiler to measure the voltage, and a data collector is arranged to transmit data in a wireless manner; the data collector reads the current and voltage values at a sampling frequency of once every 30 seconds.

[0009] The real-time power is calculated as: real-time power = real-time voltage x real-time current x power factor, wherein the coal-fired boiler and the first electric boiler and the second electric boiler supply heat at the same time, the hot water output by the coal-fired boiler, the first electric boiler and the second electric boiler is supplied to the heat exchanger, and the coal-fired boiler always works at a set power.

[0010] As a preferred scheme of the circulating water pump control method based on real-time power optimization, the control flow is determined according to the set power P set , the first real-time power P r1 and the second real-time power P r2 , to determine the control flow of the first water supply circulating water pump, the second water supply circulating water pump and the third water supply circulating water pump, and to obtain the first control flow, the second control flow and the third control flow, respectively.

[0011] According to the real-time power of the first electric boiler and the second electric boiler and the set power of the coal-fired boiler, the power proportion of each boiler is calculated.

[0012] Wherein, P1, P2 and P3 represent the power proportion of the coal-fired boiler, the first electric boiler and the second electric boiler, respectively.

[0013] The relationship between power and flow is established, and the power of each boiler is proportional to the flow, and the power proportion is used as the flow proportion: F1=P1; F2=P2; F3=P3.

[0014] The control flow is finally obtained as:

[0015] Wherein, F1, F2 and F3 represent the proportional coefficient of the hot water flow of each boiler, Q 11 , Q 22 and Q 33 represent the control flow of the coal-fired boiler, the first electric boiler and the second electric boiler, respectively, and Q 总 represents the total flow.

[0016] As a preferred scheme of the circulating water pump control method based on real-time power optimization, the layered operation includes initializing the rotating speeds of the first water supply circulating water pump, the second water supply circulating water pump and the third water supply circulating water pump, and making the output flow equal to the calculated control flow.

[0017] The power of the first electric boiler, the second electric boiler and the coal-fired boiler is monitored in real time, and the actual flow of the first water supply circulating water pump, the second water supply circulating water pump and the third water supply circulating water pump is monitored in real time, the actual flow is compared with the calculated control flow, the deviation is calculated, and the rotating speed of the water pump is adjusted according to the deviation;

[0018] When the power fluctuation of the first electric boiler or the second electric boiler exceeds a set threshold, the power proportion of the first electric boiler or the second electric boiler is adjusted according to the fluctuation direction, and the control flow of the water supply circulating water pump is adjusted;

[0019] When the power fluctuation of the coal-fired boiler exceeds a set threshold, the power proportion of the coal-fired boiler is adjusted, and the control flow of the water supply circulating water pump is adjusted;

[0020] When the system operates in the energy-saving mode, the power proportion of the first electric boiler and the second electric boiler is adjusted according to the energy-saving strategy, and the control flow of the water supply circulating water pump is adjusted.

[0021] As a preferred scheme of the circulating water pump control method based on real-time power optimization, the target function is established by taking the sum of the flow changes of the first water supply circulating water pump, the second water supply circulating water pump and the third water supply circulating water pump as the target after the first real-time power and the second real-time power change,

[0022] Wherein, i is the number of the coal-fired boiler, the first electric boiler and the second electric boiler, i=1, 2, 3 respectively represent the coal-fired boiler, the first electric boiler and the second electric boiler, Q i1 represents the control flow of the water supply circulating water pump connected to the corresponding boiler, i2 represents the adjustment flow of the water supply circulating water pump connected to the corresponding boiler;

[0023] The constraint condition is: Q i1 ≤Q imax ; Q i2 ≤Q imax ; cW i1 ·Δt i =P i1 ,W i1 =ρQ i1 ; cW i2 ·Δt i =P i2 ,Wi2 = pQ i2 ;

[0024] wherein Q 总 represents the total flow rate, Q imax represents the maximum flow rate of the water supply circulating water pump corresponding to the boiler connection, c represents the specific heat capacity of water, W i1 represents the mass flow rate before adjustment of the water supply circulating water pump corresponding to the boiler connection, W i2 represents the mass flow rate after adjustment of the water supply circulating water pump corresponding to the boiler connection, Δt i represents the temperature difference of the water input and output corresponding to the boiler, P i1 and P i2 respectively represent the power before and after the change of the boiler, and p is the density of water.

[0025] As a preferred scheme of the circulating water pump control method based on real-time power optimization, the method comprises the following steps: randomly generating N individuals, each individual containing n=9 genes representing the adjustment flow rate combination of the water supply circulating water pumps of the three boilers; calculating the multi-objective fitness for each individual; using non-dominated sorting to evaluate the Pareto level of the individual, and selecting according to the Pareto level and the crowding distance of the individual to maintain the diversity of the population; adjusting the crossover rate through the average fitness and the best fitness of the current population, performing the crossover operation on the selected individual to generate a new individual; adjusting the mutation step size according to the iteration number and the maximum iteration number, and performing the mutation operation on the new individual after the crossover; and outputting the new individual with the best fitness.

[0026] For each individual, the multi-objective fitness is calculated:

[0027] wherein F(Q) represents the multi-objective fitness, and E(Q) represents the energy consumption function.

[0028] The non-dominated sorting is used to evaluate the Pareto level of the individual, and the selection is performed according to the Pareto level and the crowding distance of the individual to maintain the diversity of the population:

[0029] wherein P represents the current population, < represents the Pareto dominance relationship, and F(Q') represents the fitness of the other individual Q'.

[0030] The crossover rate is adjusted through the average fitness and the best fitness of the current population, the crossover operation is performed on the selected individual to generate a new individual:

[0031] wherein r c represents the crossover rate of the current iteration, r c0 represents the initial crossover rate, F avg represents the initial crossover rate, F best represents the best fitness in the current population.

[0032] The mutation step size is adjusted according to the iteration number and the maximum iteration number, and the mutation operation is performed on the new individual after the crossover:

[0033] wherein ΔQg denotes the mutation step size of the gth iteration, AQ0 denotes the initial step size, G denotes the maximum number of iterations, and k denotes a parameter controlling the step size reduction rate;

[0034] The mutation rate is adjusted according to the average fitness and the best fitness of the population:

[0035] wherein r m denotes the current iteration mutation rate, r m0 denotes the initial mutation rate;

[0036] The newly generated individuals are merged with the original population, and the merged population is selected using non-dominated sorting and crowding distance to form a new population. In each generation, a certain number of elite individuals, i.e., individuals with the smallest objective function values in the previous population, are directly entered into the next generation for updating the optimal population. When the objective function value of an individual in the new population is smaller than the objective function value of the worst individual in the current optimal population, the new individual replaces the worst individual in the optimal population. When the objective function value of the optimal individual in the new population is smaller than the objective function value of the optimal individual in the current optimal population, the optimal population is updated.

[0037] Let J be the size of the elite population, P be the current population, and P' be the new population. Then: P elite = Sort (P∪P′)[:J];

[0038] wherein P elite denotes the elite population, Sort denotes sorting of a set, and [:J] denotes taking the first J individuals after sorting;

[0039] The objective function value of the new population is calculated. When the objective function value of the optimal individual in the new population is smaller than the objective function value of the optimal individual in the optimal population P best , the optimal population is updated: P best = P best ∪{Q′ best}-{Q worst};

[0040] wherein Q′ best denotes the optimal individual in the new population, and Q worst denotes the individual with the largest objective function value;

[0041] When an individual in the new population is better than the worst individual in the optimal population, the individual is replaced. The algorithm stops when one of the following conditions is met:

[0042] The maximum number of iterations is reached, the objective function value reaches a preset threshold, and the optimal objective function value of several consecutive generations does not improve significantly. After the algorithm stops, the optimal population P best is output.

[0043] As a preferred scheme of the circulating water pump control method based on real-time power optimization, wherein: the synchronous regulation of the water supply circulating water pump comprises defining DFBI as the sum of the ratio of the flow variation of each pump to the total flow variation:

[0044] Wherein, DFBI represents the dynamic flow balance index, ΔQ1, ΔQ2, ΔQ3 represent the flow variation of three different pumps respectively, ΔQ 总 represents the sum of the flow variation of all pumps, when DFBI < θ DFBI = 0.05, trigger the flow redistribution mechanism;

[0045] Define EEWC as the sum of the ratio of the power variation of each pump before and after regulation to the total power variation:

[0046] Wherein, EEWC represents the energy efficiency fluctuation coefficient, ΔP1, ΔP2, ΔP3 represent the power variation of three different pumps before and after regulation respectively, ΔP 总 represents the sum of the power variation of all pumps;

[0047] When EEWC > θ EEWC = 0.1, execute the following regulation strategy:

[0048] Calculate the power change rate of each pump P i0 represents the initial power of pump i, and the pump with the maximum ΔP′ i is preferentially regulated; calculate the energy efficiency change rate of each pump Adjust the corresponding pump in the order of energy efficiency change rate value from large to small, and dynamically adjust θ EEWC according to historical operation data and current working conditions;

[0049] Calculate the temperature difference change rate:

[0050] Wherein, Δt 初期 represents the average input and output water temperature difference under the initial state, Δt i represents the input and output water temperature difference of the i-th boiler, when TDCR > θ TDCR = 1.2, start the temperature difference compensation regulation strategy;

[0051] When DFBI < θ DFBI and EEWC ≤ θ EEWC , only adjust the pump flow, and other system parameters remain unchanged; when EEWC > θ EEWC and TDCR ≤ θ TDCRWhen TDCR>θ, the water pump with the optimal energy efficiency is adjusted preferentially, and the adjustment of other water pumps is considered. TDCR When TDCR>θ, the temperature difference compensation adjustment strategy is started, the working state of all water pumps is adjusted, and stable operation of the system is ensured.

[0052] Another object of the present application is to provide a circulating water pump control system based on real-time power optimization, which can efficiently and accurately control the heat distribution generated by different energy sources and the working state of the circulating water pump, so as to realize the optimal utilization of heat energy and the minimization of energy consumption.

[0053] As a preferred scheme of the circulating water pump control system based on real-time power optimization, the system comprises a data acquisition module, a real-time power calculation module, a control flow determination module, a hierarchical working control module, and a target function solving module.

[0054] The data acquisition module acquires current and voltage data in the power supply line of the electric boiler in real time, and provides basic data for subsequent power calculation.

[0055] The real-time power calculation module calculates the real-time power of the electric boiler according to the acquired current and voltage data.

[0056] The control flow determination module determines the control flow of each water supply circulating water pump according to the real-time power and the set power, so as to ensure that the heating proportion of each boiler matches the power proportion.

[0057] The hierarchical working control module adjusts the speed of the water pump to realize hierarchical working control of the water supply circulating water pump, and ensures stable operation of the system.

[0058] The target function solving module solves the target function by using a genetic algorithm to find the optimal adjustment flow combination, and realizes accurate control of the water supply circulating water pump.

[0059] A computer device comprises a memory and a processor, and the memory stores a computer program.

[0060] A computer readable storage medium stores a computer program, and the computer program is executed by a processor to realize the steps of the circulating water pump control method based on real-time power optimization.

[0061] The beneficial effects of the present application: the method determines the flow of each circulating water pump according to the proportion of power in the initial stage, and after the power changes, the optimal flow is determined by minimizing the sum of the flow change of all circulating water pumps, so that the circulating water pump can quickly adapt to the change of power, and then each boiler can work in the best state, and the energy is maximized. BRIEF DESCRIPTION OF DRAWINGS

[0062] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings needed in the embodiment description will be briefly introduced as follows. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative labor. Among them:

[0063] Fig. 1 is a flowchart of a circulating water pump control method based on real-time power optimization according to an embodiment of the present application.

[0064] Fig. 2 is a working module diagram of a circulating water pump control system based on real-time power optimization according to an embodiment of the present application. DETAILED DESCRIPTION

[0065] In order to make the above-mentioned purposes, features and advantages of the present application more apparent and easy to understand, the specific embodiments of the present application will be described in detail below with reference to the drawings. Obviously, the described embodiments are part of the embodiments of the present application, not all embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor should be within the scope of protection of the present application.

[0066] In the following description, many specific details are set forth in order to provide a thorough understanding of the present application, but the present application can also be implemented in other ways different from the description, and those skilled in the art can make similar generalizations without departing from the scope of the present application. Therefore, the present application is not limited to the specific embodiments disclosed below.

[0067] Secondly, the "one embodiment" or "embodiment" referred to herein means that the specific features, structures or characteristics can be included in at least one implementation of the present application. In this specification, "in one embodiment" does not mean the same embodiment, nor does it mean an embodiment that is separate or selectively excluded from other embodiments.

[0068] The application is described in detail in combination with the schematic diagram. In the detailed description of the embodiments of the application, the sectional view of the device structure is partially enlarged without the general proportion for the convenience of illustration, and the schematic diagram is only an example which should not limit the scope of protection of the application herein. In addition, the three-dimensional spatial dimensions of length, width and depth should be included in the actual manufacture.

[0069] Meanwhile, in the description of the application, it should be noted that the orientation or positional relationship indicated by the terms "upper, lower, inner and outer" is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the application and simplifying the description, and does not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the application. In addition, the terms "first, second or third" are only for descriptive purposes and cannot be understood as indicating or implying relative importance.

[0070] In the application, unless otherwise explicitly specified and limited, the terms "mounting, connection, connection" should be understood broadly, for example: it can be fixed connection, detachable connection or integral connection; it can also be mechanical connection, electrical connection or direct connection, it can also be indirectly connected through an intermediate medium, or it can be the communication inside two elements. For those skilled in the art, the specific meaning of the above terms in the application can be understood according to the specific circumstances.

[0071] Embodiment 1, referring to FIG. 1, is the first embodiment of the application, which provides a circulating water pump control method based on real-time power optimization, comprising:

[0072] S1: Collecting real-time power of the first electric boiler and the second electric boiler.

[0073] Further, the collecting real-time power of the first electric boiler and the second electric boiler comprises: connecting a current transformer in series in the power supply line of the electric boiler to measure the current in a non-intrusive manner, connecting a voltage sensor in parallel in the power supply line of the electric boiler to measure the voltage, and setting a data collector to transmit data wirelessly; the data collector reads the current and voltage values at a sampling frequency of once every 30 seconds;

[0074] Calculating real-time power: real-time power = real-time voltage x real-time current x power factor, wherein the coal-fired boiler and the first electric boiler and the second electric boiler supply heat at the same time, the hot water output by the coal-fired boiler, the first electric boiler and the second electric boiler is supplied to the heat exchanger, and the coal-fired boiler always works at the set power.

[0075] S2: Determining the control flow according to the set power and the collected real-time power, and controlling the corresponding water supply circulating water pump to work in layers.

[0076] Further, the determining the control flow comprises: determining the control flow according to the set power Pset , the first real-time power P r1 and the second real-time power P r2 Determine the control flow of the first water supply circulating water pump, the second water supply circulating water pump and the third water supply circulating water pump, respectively, to obtain the first control flow, the second control flow and the third control flow;

[0077] According to the real-time power of the first electric boiler and the second electric boiler and the set power of the coal-fired boiler, the power proportion of each boiler is calculated:

[0078] Wherein, P1, P2, P3 represent the power proportion of the coal-fired boiler, the first electric boiler and the second electric boiler respectively;

[0079] The relationship between power and flow is established, and the power of each boiler is proportional to the flow, and the power proportion is used as the flow proportion: F1=P1; F2=P2; F3=P3;

[0080] The final control flow is:

[0081] Wherein, F1, F2, F3 represent the proportional coefficient of the heating water flow of each boiler, Q 11 , Q 22 , Q 33 Respectively represent the control flow of the coal-fired boiler, the first electric boiler and the second electric boiler, Q 总 Indicates the total flow.

[0082] It should be noted that the hierarchical operation includes initializing the rotating speed of the first water supply circulating water pump, the second water supply circulating water pump and the third water supply circulating water pump, so that the output flow is equal to the calculated control flow;

[0083] Real-time monitoring of the power of the first electric boiler, the second electric boiler and the coal-fired boiler, and the actual flow of the first water supply circulating water pump, the second water supply circulating water pump and the third water supply circulating water pump, comparing the actual flow with the calculated control flow, calculating the deviation, and adjusting the rotating speed of the water pump according to the deviation;

[0084] When the power fluctuation of the first electric boiler or the second electric boiler exceeds the set threshold, adjust the power proportion according to the fluctuation direction, and adjust the control flow of the water supply circulating water pump;

[0085] When the power fluctuation of the coal-fired boiler exceeds the set threshold, adjust the power proportion, and adjust the control flow of the water supply circulating water pump;

[0086] When the system runs in the energy-saving mode, the power ratio of the first electric boiler and the second electric boiler is adjusted according to the energy-saving strategy, and the control flow of the water supply circulating water pump is adjusted.

[0087] S3: When the real-time power changes, a target function is established with the sum of the flow changes of the water supply circulating water pumps as the target, and a constraint condition is set.

[0088] Further, the target function includes, after the first real-time power and the second real-time power change, establishing a target function with the sum of the flow changes of the first water supply circulating water pump, the second water supply circulating water pump and the third water supply circulating water pump as the target,

[0089] Wherein, i is the number of the coal-fired boiler, the first electric boiler and the second electric boiler, i = 1, 2, 3 respectively represent the coal-fired boiler, the first electric boiler and the second electric boiler, Q i1 represents the control flow of the water supply circulating water pump connected to the corresponding boiler, Q i2 represents the adjusted flow of the water supply circulating water pump connected to the corresponding boiler;

[0090] The constraint condition is: Q i1 ≤Q imax ; Q i2 ≤Q imax ; cW i1 ·Δt i =P i1 ,W i1 =ρQ i1 ; cW i2 ·Δt i =P i2 ,W i2 =ρQ i2 ;

[0091] Wherein, Q 总 represents the total flow, Q imax represents the maximum flow of the water supply circulating water pump connected to the corresponding boiler, c represents the specific heat capacity of water, W i1 represents the mass flow of the water supply circulating water pump connected to the corresponding boiler before adjustment, W i2 represents the mass flow of the water supply circulating water pump connected to the corresponding boiler after adjustment, Δt i represents the temperature difference between the input water and the output water of the corresponding boiler, P i1 and P i2 respectively represent the power before and after the change of the corresponding boiler, and ρ is the density of water.

[0092] S4: Genetic algorithm is used to solve the target function to obtain the adjusted flow of the water supply circulating water pump.

[0093] Further, the solving the objective function by using the genetic algorithm includes randomly generating N individuals, each of which contains n=9 genes representing the combination of the regulating flow of the water supply circulating pumps of the three boilers;

[0094] For each individual, a multi-objective fitness is calculated:

[0095] Wherein, F(Q) represents the multi-objective fitness, and E(Q) represents the energy consumption function;

[0096] The non-dominated sorting is used to evaluate the Pareto level of the individual, and the selection is performed according to the Pareto level and the crowding distance of the individual, so as to maintain the diversity of the population:

[0097] Wherein, P represents the current population, < represents the Pareto dominance relationship, and F(Q') represents the fitness of other individual Q';

[0098] The crossover rate is adjusted by the average fitness and the best fitness of the current population, the selected individual is subjected to the crossover operation, and a new individual is generated:

[0099] Wherein, r c represents the crossover rate of the current iteration, r c0 represents the initial crossover rate, F avg represents the initial crossover rate, F best represents the best fitness in the current population;

[0100] The mutation step length is adjusted according to the iteration number and the maximum iteration number, and the new individual after the crossover is subjected to the mutation operation:

[0101] Wherein, ΔQ g represents the mutation step length of the gth iteration, ΔQ0 represents the initial step length, G represents the maximum iteration number, and k represents a parameter for controlling the step length descending rate;

[0102] The mutation rate is adjusted according to the average fitness and the best fitness of the population:

[0103] Wherein, r m represents the current iteration mutation rate, r m0 represents the initial mutation rate;

[0104] The newly generated individuals are combined with the original population, the combined population is selected using non-dominated sorting and crowding distance to form a new population, in each generation, a certain number of elite individuals, i.e. the individuals with the minimum objective function value in the previous population, are directly entered into the next generation, and the optimal population updating operation is performed, when the objective function value of an individual in the new population is less than the objective function value of the worst individual in the current optimal population, the worst individual in the optimal population is replaced by the new individual, and when the objective function value of the optimal individual in the new population is less than the objective function value of the optimal individual in the current optimal population, the optimal population is updated;

[0105] J is the size of the elite population, P is the current population, and P' is the new population, then: P elite = Sort (P∪P′)[:J];

[0106] P elite represents the elite population, Sort represents sorting the set, and [:J] represents taking the first J individuals after sorting;

[0107] The objective function value of the new population is calculated, and when the objective function value of the optimal individual in the new population is less than the objective function value of the optimal individual in the optimal population P best , the optimal population is updated: P best = P best ∪{Q′ best}-{Q worst};

[0108] Q′ best represents the optimal individual in the new population, and Q worst represents the individual with the maximum objective function value;

[0109] When the individual in the new population is better than the worst individual in the optimal population, the replacement is performed; the algorithm stops when one of the following conditions is met:

[0110] The maximum number of iterations is reached, the objective function value reaches a preset threshold, and the optimal objective function value of several generations does not improve significantly; after the algorithm stops, the optimal population P best is output.

[0111] S5: According to the obtained regulating flow, the water supply circulating water pump is synchronously regulated.

[0112] Further, the synchronous regulation of the water supply circulating water pump includes defining DFBI as the sum of the ratios of the flow change amounts of each pump to the total flow change amount monitored in real time:

[0113] Wherein, DFBI represents the dynamic flow balance index, ΔQ1, ΔQ2 and ΔQ3 represent the flow change amounts of three different pumps, respectively, and ΔQ总 DFBI represents the sum of all water pump flow rate change amounts, when DFBI < θ DFBI = 0.05, the flow rate redistribution mechanism is triggered;

[0114] EEWC is defined as the sum of the ratio of the power change amount of each water pump before and after adjustment to the total power change amount:

[0115] EEWC represents the energy efficiency fluctuation coefficient, ΔP1, ΔP2 and ΔP3 represent the power change amounts of three different water pumps before and after adjustment, respectively, and ΔP 总 represents the sum of all water pump power change amounts;

[0116] When EEWC > θ EEWC = 0.1, the following adjustment strategy is executed:

[0117] The power change rate of each water pump is calculated P i0 represents the initial power of the water pump i, and the water pump with the maximum ΔP' i is preferentially adjusted; the energy efficiency change rate of each water pump is calculated The corresponding water pump is adjusted in the order of the energy efficiency change rate from large to small, and θ EEWC is dynamically adjusted according to historical operation data and the current working condition;

[0118] The temperature difference change rate is calculated:

[0119] Δt 初期 represents the average input and output water temperature difference under the initial state, Δt i represents the input and output water temperature difference of the i-th boiler, when TDCR > θ TDCR = 1.2, the temperature difference compensation adjustment strategy is started;

[0120] When DFBI < θ DFBI and EEWC ≤ θ EEWC , only the water pump flow rate is adjusted, and other system parameters remain unchanged; when EEWC > θ EEWC and TDCR ≤ θ TDCR , the water pump with the optimal energy efficiency is preferentially adjusted, and the adjustment of other water pumps is considered; when TDCR > θ TDCR , the temperature difference compensation adjustment strategy is started, the working state of all water pumps is adjusted, and stable operation of the system is ensured, and when multiple adjustment requirements conflict, the priority order is EEWC > DFBI > TDCR.

[0121] Embodiment 2, which is an embodiment of the present application, provides a circulating water pump control method based on real-time power optimization, in order to verify the beneficial effects of the present application, scientific demonstration is carried out through experiments.

[0122] S100, collecting real-time power of the first electric boiler and the second electric boiler, and obtaining a first real-time power and a second real-time power respectively; wherein the coal-fired boiler, the first electric boiler and the second electric boiler supply heat at the same time, the hot water output by the coal-fired boiler, the first electric boiler and the second electric boiler is supplied to the heat exchanger, and the coal-fired boiler always works at a set power.

[0123] The heat exchanger is arranged in a heat exchange station, and the hot water output by each boiler at a temperature of about 130 degrees Celsius is input into the heat exchanger through a water supply circulating pump, and then the heat is transferred to the secondary network, and the temperature is reduced to about 70 degrees Celsius, and the backwater is formed to return to the input end of the boiler, thereby realizing the recycling of water.

[0124] In the process of supplying power, the voltage detection unit and the current detection unit detect the voltage and the current of the boiler respectively, determine the real-time power according to the voltage and the current, compare the real-time power with the rated power, and if the real-time power exceeds the rated power, limit the current to make the real-time power drop to or below the rated power. In the case of ensuring that the real-time power of the electric boiler does not exceed the rated power, the product of the current and the voltage of the electric boiler is taken as the corresponding real-time power. The coal-fired boiler itself has a certain heating power, and the coal-fired boiler will also work at a set power in the subsequent work. The purpose of the present application is to adjust the flow of each water supply circulating pump without actively changing the power of each boiler.

[0125] S110, determining the control flow of the first water supply circulating pump 100, the second water supply circulating pump 200 and the third water supply circulating pump 300 according to the set power, the first real-time power and the second real-time power, and obtaining a first control flow, a second control flow and a third control flow respectively; wherein the first water supply circulating pump 100, the second water supply circulating pump 200 and the third water supply circulating pump 300 are connected to the output ends of the coal-fired boiler, the first electric boiler and the second electric boiler respectively.

[0126] Exemplarily, when the present application determines the first control flow, the second control flow and the third control flow, the ratio of the set power, the first real-time power and the second real-time power is determined first, and then the total flow is divided into the first control flow, the second control flow and the third control flow according to the ratio; wherein the total flow is the sum of the flows of the first water supply circulating pump 100, the second water supply circulating pump 200 and the third water supply circulating pump 300.

[0127] The total flow can remain unchanged in any case, at this time, in order to ensure that the heat output through the heat exchanger is unchanged, the return water temperature of each boiler will remain unchanged, and the temperature difference between the supply water and the return water is maintained at about 60 degrees Celsius. Of course, the total flow can also change to a certain extent, but it is necessary to ensure that the heat output through the heat exchanger is unchanged, at this time, it is necessary to appropriately reduce the temperature difference between the supply water and the return water when the total flow increases, and the temperature difference can be reduced by increasing the control flow of each supply water circulating water pump, when the flow of the supply water circulating water pump increases, the total flow will increase, but the temperature difference between the output water and the input water of the boiler will decrease when the power of the boiler is unchanged, that is, the supply water temperature will decrease by a large margin when the return water temperature is unchanged or slightly decreases, and the purpose of reducing the temperature difference between the supply water and the return water is achieved.

[0128] Whether the total flow changes or not, the total flow will be the sum of the flows of each supply water circulating water pump.

[0129] Further, the input ends of the coal-fired boiler, the first electric boiler and the second electric boiler are respectively connected with the first return water circulating water pump 110, the second return water circulating water pump 210 and the third return water circulating water pump 310, and the flows of the first return water circulating water pump 110, the second return water circulating water pump 210 and the third return water circulating water pump 310 are respectively kept the same as the first supply water circulating water pump 100, the second supply water circulating water pump 200 and the third supply water circulating water pump 300. When the flows of the supply water circulating water pump and the return water circulating water pump corresponding to the boiler are kept consistent, it can be ensured that the water level in each boiler remains unchanged.

[0130] S120, respectively controlling the first supply water circulating water pump 100, the second supply water circulating water pump 200 and the third supply water circulating water pump 300 to work according to the first control flow, the second control flow and the third control flow.

[0131] Exemplarily, the first supply water circulating water pump 100, the first return water circulating water pump 110, the second supply water circulating water pump 200, the second return water circulating water pump 210, the third supply water circulating water pump 300 and the third return water circulating water pump 310 can all adopt frequency conversion pumps, and each circulating water pump realizes control of the rotating speed of the water pump through a respective frequency conversion controller, thereby realizing adjustment of the flow.

[0132] S130, after the first real-time power and the second real-time power change, establishing a target function with the sum of the flow change amounts of the first supply water circulating water pump 100, the second supply water circulating water pump 200 and the third supply water circulating water pump 300 being the minimum as the target.

[0133] The heat that the boiler output water increases relative to the input water in unit time is equal to the heating power of the boiler. In the case where the supply water temperature and the return water temperature are unchanged, the temperature difference Δt iare 60 degrees Celsius, and in the case that the specific heat capacity and density of water are known (the specific heat capacity of water is taken as 4.18 x 10^3 J / (kg·℃), and the density of water is taken as 1 x 10^3 kg / m3), the constraints can be expressed as: 2.508 x 10 8 J / m 3 · Q i1 = P i1 2.508 x 10 8 J / m 3 · Q i2 = P i2

[0134] S140, the target function is solved to obtain the first adjusting flow rate, the second adjusting flow rate, and the third adjusting flow rate of the first water supply circulating water pump 100, the second water supply circulating water pump 200, and the third water supply circulating water pump 300, respectively.

[0135] Exemplarily, a genetic algorithm can be used to solve the target function. When the genetic algorithm is used to solve, a plurality of populations are first generated according to a set step size, each population is a combination of the adjusting flow rates of all water supply circulating water pumps, and then selection, crossover, and mutation processing are sequentially performed on the populations, and the populations that meet the target function after processing are taken as the optimal population.

[0136] Specifically, the adjusting flow rates in each population will meet the respective constraints, and the difference between any two adjusting flow rates of the same circulating water pump is a positive integer multiple of the step size. When the selection processing in the genetic algorithm is used, the fitness value of each population is first calculated, the fitness value is calculated based on the target function, and then a few populations with the highest fitness values are selected to enter the next crossover processing. In the crossover processing, individuals in two populations are randomly exchanged to form a new population, and in the mutation processing, individuals in the population are modified to a certain extent. After sequentially completing the selection, crossover, and mutation processing, one iteration is completed, and when the number of iterations reaches a set value, the population with the highest fitness value is output as the optimal population.

[0137] After the genetic algorithm is used, the diversity of the population can be improved as much as possible, the sample space for selecting the optimal population is increased, and the accuracy of the optimal sample is improved.

[0138] S150, the first water supply circulating water pump 100, the second water supply circulating water pump 200, and the third water supply circulating water pump 300 are controlled to work according to the first adjusting flow rate, the second adjusting flow rate, and the third adjusting flow rate, respectively.

[0139] Exemplarily, the same as controlling the flow rate, the frequency converter of each water supply circulating water pump can be adjusted to achieve the purpose of adjusting the flow rate of the water supply circulating water pump.

[0140] It should be noted that the above examples are only used to illustrate the technical solutions of the present application but not limit the present application. Although the present application is described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present application can be modified or equivalently replaced without departing from the spirit and scope of the present application, and all these modifications and replacements should be included in the scope of the claims of the present application.

[0141] Embodiment 3, the third embodiment of the present application, is different from the first two embodiments in that:

[0142] If the functions are realized in the form of software function units and sold or used as independent products, they can be stored in a computer readable storage medium. Based on this understanding, the technical solutions of the present application or the parts of the present application that essentially contribute to the prior art or the parts of the technical solutions can be embodied in the form of software products. The computer software product is stored in a storage medium and includes a plurality of instructions for causing a computer device (which can be a personal computer, a server, or a network device, etc.) to execute all or part of the steps of the method described in the embodiments of the present application. The aforementioned storage medium includes a U disk, a mobile hard disk, a read-only memory (ROM, Read-Only Memory), a random access memory (RAM, Random Access Memory), a magnetic disk or an optical disk, and various media that can store program codes.

[0143] The logic and / or steps represented in the flowchart or otherwise described herein, for example, can be considered a list of executable instructions for implementing logic functions, and can be specifically embodied in any computer-readable medium for use by an instruction execution system, apparatus or device, such as a computer-based system, a system including a processor or other system that can fetch and execute instructions from the instruction execution system, apparatus or device, or in conjunction with these instructions. For the purpose of this specification, "computer-readable medium" can be any device that can contain, store, communicate, propagate or transport programs for use by an instruction execution system, apparatus or device, or in conjunction with these instruction execution systems, apparatus or devices.

[0144] More specific examples (a non-exhaustive list) of the computer-readable medium include the following: an electrical connection (electronic) having one or more wires, a portable computer diskette (magnetic), a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or Flash memory), an optical fiber, and a portable compact disc read-only memory (CDROM). Additionally, the computer readable medium can be paper or another suitable medium upon which the program is printed, as the program can be electronically captured, for example via optical scanning of the paper or other medium, then compiled, interpreted, or otherwise processed in a suitable manner, if necessary, and stored in a computer memory.

[0145] It should be understood that aspects of the application can be implemented in hardware, software, firmware or combinations thereof. In the above embodiments, various steps or methods can be implemented in software or firmware that is stored in memory and executed by a suitable instruction execution system. For example, if implemented in hardware, as in another embodiment, any of the following technique, known in the art, or their combinations can be used: discrete logic circuit with logic gate circuit for implementing logic functions on data signals, application specific integrated circuit with suitable combination logic gate circuit, programmable gate array (PGA), field programmable gate array (FPGA), etc.

[0146] Embodiment 4, referring to Figure 2, provides a real-time power optimization based circulating water pump control system, characterized in that: comprising a data acquisition module, a real-time power calculation module, a control flow determination module, a hierarchical working control module, and a target function solving module.

[0147] The data acquisition module acquires current and voltage data in the power supply line of the electric boiler in real time, providing basic data for subsequent power calculation.

[0148] The real-time power calculation module calculates the real-time power of the electric boiler according to the acquired current and voltage data.

[0149] The control flow determination module determines the control flow of each water supply circulating water pump according to the real-time power and the set power, to ensure that the heating proportion of each boiler matches the power proportion.

[0150] The hierarchical working control module realizes hierarchical working control of the water supply circulating water pump by adjusting the speed of the water pump, to ensure stable operation of the system.

[0151] The target function solving module solves the target function by genetic algorithm to find the optimal adjustment flow combination, to realize accurate control of the water supply circulating water pump.

[0152] It should be noted that the above examples are only used to illustrate the technical solutions of the present application but not to limit the present application. Although the present application is described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present application can be modified or equivalently replaced, without departing from the spirit and scope of the technical solutions of the present application, and all of them should be covered in the scope of the claims of the present application.

Claims

1. A real-time power optimization based circulating water pump control method, characterized in that: Comprising, Collecting real-time power of the first and second electric boilers; Determining control flow according to set power and collected real-time power, and controlling layered operation of corresponding water supply circulating pumps; When real-time power changes, establishing a target function with the minimum sum of water supply circulating pump flow changes as the target, and setting a constraint condition; Solving the target function by using a genetic algorithm to obtain the corresponding adjustment flow of the water supply circulating pumps; Synchronously adjusting the operation of the water supply circulating pumps according to the obtained adjustment flow.

2. A real-time power optimization based circulating water pump control method as claimed in claim 1, wherein: The collecting of the real-time power of the first and second electric boilers comprises: connecting a current transformer in series in a power supply line of the electric boiler to measure the current in a non-intrusive manner, connecting a voltage sensor in parallel in the power supply line of the electric boiler to measure the voltage, and setting a data collector to transmit data in a wireless manner; the data collector reads the current and voltage values at a sampling frequency of once every 30 seconds; Calculating real-time power: real-time power = real-time voltage x real-time current x power factor, wherein the coal-fired boiler and the first and second electric boilers supply heat at the same time, the hot water output by the coal-fired boiler, the first electric boiler and the second electric boiler is supplied to a heat exchanger, and the coal-fired boiler always operates at a set power.

3. A real-time power optimization based circulating water pump control method as claimed in claim 2, wherein: The determining the control flow rate comprises determining control flow rates of the first water supply circulating water pump, the second water supply circulating water pump and the third water supply circulating water pump according to the set power P set , the first real-time power P r1 and the second real-time power P r2 , respectively obtaining a first control flow rate, a second control flow rate and a third control flow rate. According to the real-time power of the first and second electric boilers and the set power of the coal-fired boiler, the power proportion of each boiler is calculated: Wherein, P1, P2 and P3 represent the power proportion of the coal-fired boiler, the first electric boiler and the second electric boiler respectively; Establishing a relationship between power and flow, the power of each boiler is proportional to the flow, and the power proportion is used as the flow proportion: F1 = P1 F2 = P2 F3 = P3 The layered operation comprises initializing the rotating speed of the first, second and third water supply circulating pumps to make the output flow equal to the calculated control flow; The final control flow is: Wherein, F1, F2, F3 represent the proportional coefficient of each boiler heating water flow, Q 11 , Q 22 , Q 33 respectively represent the control flow of the coal-fired boiler, the first electric boiler and the second electric boiler, Q 总 represents the total flow.

4. A real-time power optimization based circulating water pump control method as claimed in claim 3, wherein: Real-time monitoring of the power of the first electric boiler, the second electric boiler and the coal-fired boiler, and the actual flow of the first, second and third water supply circulating pumps, comparing the actual flow with the calculated control flow, calculating the deviation, and adjusting the rotating speed of the water pump according to the deviation; When the power fluctuation of the first electric boiler or the second electric boiler exceeds a set threshold, adjusting the power proportion and the control flow of the water supply circulating pump according to the fluctuation direction; When the power fluctuation of the coal-fired boiler exceeds a set threshold, adjusting the power proportion and the control flow of the water supply circulating pump; When the system operates in an energy-saving mode, adjusting the power proportion of the first and second electric boilers and the control flow of the water supply circulating pump according to an energy-saving strategy. Indicates the adjustment flow of the water supply circulating pump connected to the corresponding boiler.

5. A real-time power optimization based circulating water pump control method as claimed in claim 4, wherein: The establishing the objective function includes, after the first real-time power and the second real-time power change, establishing an objective function with a sum of flow change amounts of the first water supply circulating water pump, the second water supply circulating water pump, and the third water supply circulating water pump as a target, wherein i is the number of the coal-fired boiler, the first electric boiler and the second electric boiler, i = 1, 2, 3 respectively represent the coal-fired boiler, the first electric boiler and the second electric boiler, denotes the control flow for the feed water circulating pump corresponding to the boiler connection, The density of water. The constraint condition is: Q i1 ≤Q imax Q i2 ≤Q imax cW i1 • Δt i = P i1 ,W i1 = ρQ i1 cW i2 • Δt i = P i2 ,W i2 = ρQ i2 where Q 总 represents the total flow rate, Q imax represents the maximum flow rate of the water supply circulating water pump connected to the boiler, c represents the specific heat capacity of water, W i1 represents the mass flow rate before adjustment of the water supply circulating water pump connected to the boiler, W i2 represents the mass flow rate after adjustment of the water supply circulating water pump connected to the boiler, Δt i represents the temperature difference of the water input and output to the boiler, P i1 and P i2 respectively represent the power before and after the change of the boiler, The solving of the target function by using a genetic algorithm comprises randomly generating N individuals, each individual containing n = 9 genes representing the adjustment flow combination of the water supply circulating pumps of the three boilers; 6. A real-time power optimization based circulating water pump control method as claimed in claim 5, wherein: Wherein, F(Q) represents a multi-objective fitness, and E(Q) represents an energy consumption function; For each individual, the multi-objective fitness is calculated: Wherein, P represents the current population, < represents a Pareto dominance relationship, and F(Q') represents the fitness of other individuals Q'. The Pareto ranking of individuals is evaluated using non-dominated sorting, selection is made according to the Pareto ranking and crowding distance of individuals, and the diversity of the population is maintained: ​ The crossover rate is adjusted by the average fitness and the best fitness of the current population, and the selected individuals are crossed to generate new individuals: where r c represents the crossover rate of the current iteration, r c0 represents the initial crossover rate, F avg represents the initial crossover rate, F best represents the best fitness in the current population; Adjusting the mutation step size according to the iteration number and the maximum iteration number, and performing a mutation operation on the new individual after the crossover: where ΔQ g where ΔQg represents the variation step size at the gth iteration, ΔQ0represents the initial step size, G represents the maximum number of iterations, and k represents a parameter that controls the rate of step size decrease. Adjusting the mutation rate according to the average fitness and the best fitness of the population: where r m represents the initial mutation rate; and m0 represents the initial mutation rate; and The newly generated individuals are combined with the original population, the combined population is selected using non-dominated sorting and crowding distance to form a new generation population, a certain number of elite individuals, i.e. the individuals with the minimum objective function value in the previous population, are directly entered into the next generation to update the optimal population operation, when the objective function value of the individual in the new population is less than the objective function value of the worst individual in the current optimal population, the new individual replaces the worst individual in the optimal population, when the objective function value of the optimal individual in the new population The optimal population is updated when the objective function value of the optimal individual in the new population is less than the objective function value of the optimal individual in the current optimal population; Let J be the size of the elite population, P be the current population, and P' be the new population, then: P elite = Sort(P∪P′)[:J] where P elite denotes the elite population, Sort denotes sorting the set, and [:J] denotes taking the first J individuals after sorting. The objective function value of the new population is calculated, and when the objective function value of the optimal individual in the new population is less than the objective function value of the optimal individual in the optimal population P best , the optimal population is updated: P best = P best ∪ {Q' best} - {Q worst} where Q' = Q - Q best represents the best individual in the new population, Q worst represents the individual with the largest objective function value; When the individual in the new population is better than the worst individual in the elite population, the replacement is performed; the algorithm stops when one of the following conditions is met: The algorithm stops when the preset maximum iteration number is reached, the objective function value reaches the preset threshold, or the optimal objective function value of several generations does not improve significantly. After the algorithm stops, the optimal population P is output best .

7. A real-time power optimization based circulating water pump control method as claimed in claim 6, wherein: The synchronous regulation of the water supply circulating water pump includes defining DFBI as the sum of the ratio of each water pump flow variation to the total flow variation monitored in real time: Wherein, DFBI represents a dynamic flow balance index, AQ1, AQ2, AQ3 respectively represent flow change amounts of three different water pumps, AQ represents a sum of flow change amounts of all water pumps. 总 When DFBI < θ DFBI = 0.05, a flow redistribution mechanism is triggered. The EEWC is defined as the sum of the ratio of the power variation of each water pump before and after the adjustment to the total power variation: Wherein, EEWC represents energy efficiency fluctuation coefficient, ΔP1, ΔP2, ΔP3 respectively represent power change amount of three different water pumps before and after adjustment, ΔP 总 represents the sum of all water pump power change amount; When EEWC > θ EEWC = 0.1, the following adjustment strategy is performed: calculating a rate of change of power for each water pump P i0 represents the initial power of the water pump i, the water pump with the largest ΔP' is preferentially regulated; the energy efficiency change rate of each water pump is calculated i ​ Adjust the corresponding water pump in order from large to small according to the energy efficiency change rate value, dynamically adjust θ according to historical operation data and current working conditions EEWC ; Computing the temperature difference change rate: where Δt 初期 represents the average input-output water temperature difference in the initial state, Δt i represents the input-output water temperature difference of the i-th boiler, and when TDCR>θ TDCR = 1.2, the temperature difference compensation adjustment strategy is started. when DFBI < θ DFBI and EEWC ≤ θ EEWC , only adjust the water pump flow, and other system parameters remain unchanged; when EEWC > θ EEWC and TDCR ≤ θ TDCR , preferentially adjust the water pump with the optimal energy efficiency, and consider the adjustment of other water pumps; when TDCR > θ TDCR , start the temperature difference compensation adjustment strategy, adjust the working state of all water pumps, and ensure stable operation of the system; when multiple adjustment requirements conflict, the priority order is EEWC > DFBI > TDCR.

8. A system employing a real-time power-optimized circulating water pump control method according to any one of claims 1 to 7, characterized in that: The data acquisition module, real-time power calculation module, control flow determination module, hierarchical working control module and target function solving module are included. The data acquisition module acquires current and voltage data in the power supply line of the electric boiler in real time, providing basic data for subsequent power calculation; The real-time power calculation module calculates the real-time power of the electric boiler according to the acquired current and voltage data; The control flow determination module determines the control flow of each water supply circulating water pump according to the real-time power and the set power, to ensure that the heating proportion of each boiler matches the power proportion; The hierarchical working control module realizes hierarchical working control of the water supply circulating water pump by adjusting the speed of the water pump, to ensure stable operation of the system; The target function solving module solves the target function by using a genetic algorithm to find the optimal adjustment flow combination, to realize accurate control of the water supply circulating water pump. 9.A computer device, comprising a memory and a processor, wherein the memory stores a computer program, and the computer device is configured to perform the method according to any one of claims 1-8 when the computer program is executed by the processor. The processor executes the computer program to realize the steps of the method of any one of claims 1 to 7.

10. A computer-readable storage medium having stored thereon a computer program, characterized in that, The computer program is executed by the processor to realize the steps of the method of any one of claims 1 to 7.

Images