Method for analyzing operation carbon consumption and carbon efficiency of water pump by using model

Abstract

The invention relates to a water pump energy-saving technology, and aims to provide a method for analyzing operation carbon consumption and carbon efficiency of a water pump by using a model. The method comprises the following steps: for a specified water pump, acquiring real-time monitoring data of the flow of the specified water pump in an operation process under a power frequency condition or a variable frequency condition; a shaft power carbon consumption model, a mechanical relative carbon effect model or a variable-frequency working condition mechanical relative carbon effect model are designed through power frequency, and corresponding carbon consumption or carbon effect numerical values are obtained through calculation; and the calculation result is compared with a set safety threshold value, if a deviation result exceeding the set number appears within the set time, it is regarded that the water pump is in a continuous low-efficiency operation state, and a warning prompt is given out. According to the invention, the limitation that calculation depending on operation power consumption and standard coal consumption needs to depend on a large amount of measured data in the prior art is overcome; comprehensive visual, instant change and historical trend analysis can be carried out on the running carbon efficiency of the water pump in different states, and a theoretical basis and an analysis method are provided for carbon efficiency management of the water pump.

Description

Technical Field

[0001] The present invention relates to the energy-saving technology of water pumps, and particularly to a method for analyzing the operating carbon consumption and carbon efficiency of water pumps by using models. This method proposes a method for real-time and visual analysis of the carbon consumption and carbon efficiency of industrial-frequency and variable-frequency water pumps under variable operating conditions. Background Art

[0002] At present, clean production and green energy systems have become essential conditions for the operation of modern enterprises. However, there is still a lack of intuitive analysis basis for the total distribution and application rules of carbon consumption in the actual production process. Since there is still a lack of unified methods, standards, and benchmarking bases for carbon analysis, it is still in the exploration stage as a whole. The circulating water system is a major energy consumer in the industrial process. On the one hand, it is an important guarantee link for the stable product quality of enterprises. On the other hand, it is also a major emitter of enterprise carbon emissions. This requires that the applications of industrial processes and public utilities, which are not directly carbon-emitting, must be able to visually monitor and analyze the carbon emission equivalent (carbon flow) and carbon equivalent efficiency (carbon efficiency) of the circulating water under variable operating conditions. Thus, it can achieve true visual monitoring and control of carbon emissions corresponding to energy consumption and meet the operating control requirements of users at all levels.

[0003] As a basic component of the public auxiliary project in the industrial system, the operating energy consumption of the circulating water system accounts for 15-30% of the energy consumption of users in various industries. The current energy management system can visually monitor the operating status of water pumps by detecting the conventional operating parameters of water pumps, such as flow rate, temperature, pressure, current, voltage, and operating power, and by matching the characteristic curve of the given water pump. On this basis, through the benchmark correction coefficient of standard coal power in each local area, the operating power consumption of the water pump can be converted into standard coal consumption on the basis of the corresponding operating power consumption. Thus, it can further form real-time detection of the operating carbon consumption of the water pump under the current carbon emission conditions. This provides a numerical basis for the visual control of the carbon flow and carbon footprint of water pumps in different enterprises. Or rather, the traditional energy management system can expand the corresponding carbon emission management function with the support of this calculation model. Based on this, the current energy management system can achieve a comprehensive upgrade for carbon emission management.

[0004] However, the above analysis is essentially a passive analysis, which requires subsequent calculations based on the change of actual operating power to obtain the corresponding carbon consumption data. Moreover, this detection can only stay at the level of carbon consumption monitoring, and it is impossible to visually determine and analyze the carbon efficiency of water pumps (especially the operating carbon efficiency under different operating conditions).

[0005] For a water pump, its characteristics are on the unique characteristic curve given under different specific speed hydraulic conditions based on the similarity theory and model amplification theory. Of course, during the actual operation, due to various reasons, the impeller and flow channel are eroded, the geometric structure changes, and the actual operating condition point of the water pump will inevitably deviate from the original characteristic curve. This deviation of unknown degree will necessarily bring difficulties to the analysis of the operating efficiency and corresponding carbon efficiency change of the water pump. Therefore, for a given water pump, the analysis of its operating state must also be divided into two levels. One is the given design characteristic state (or the factory characteristic state of the water pump under the given system error condition), and the other is the actual characteristic state under the operating condition. The actual operating characteristic state is basically the same as the design characteristic state at the beginning of operation, but gradually generates respective actual offsets as the operation progresses.

[0006] That is to say, for any given water pump, if a comprehensive analysis of its operating state is required, including various model-based efficiency analyses, it needs to be carried out in two corresponding levels. And in fact, in order to achieve a comprehensive control of the operating state, it is necessary to construct an all-round analysis method that interconnects the two.

[0007] Of course, for a water pump, a more complex state is that the water pump can be frequency-converted. There are three regulation methods for the water pump: inlet throttling, outlet throttling, and speed control. A large number of practices have proved that the speed regulation control of the water pump is the most effective regulation method. Moreover, this method can retain all the basic characteristics of the water pump itself, and has strong universality for the optimization of a given system. The combined regulation of the water pump speed and the outlet valve / return water valve at the end of the circulating water system has been proved to be the most effective way to optimize the energy efficiency of the pump group under variable operating conditions. However, starting from the characteristic curve and similarity theory of the water pump, for a given water pump, each speed corresponds to its own characteristic curve. This leads to the fact that in the actual system, for a given water pump, not only the design characteristic state and the actual characteristic state need to be considered, but also analysis needs to be carried out based on the similarity theory for each speed. Thus, the difficulty and complexity of the real-time analysis of the water pump state will inevitably increase significantly.

[0008] In view of the lack of energy efficiency visualization monitoring and carbon emission management for water pumps and pump groups under variable operating conditions in the existing technology, it is necessary to propose a corresponding visualization analysis scheme for carbon consumption and carbon efficiency to realize the transformation of the traditional energy management of water pumps and pump groups to carbon emission management. Summary of the Invention

[0009] The technical problem to be solved by the present invention is to overcome the deficiencies in the existing technology and provide a method for analyzing the operating carbon consumption and carbon efficiency of a water pump using a model.

[0010] To solve the technical problem, the solution of the present invention is:

[0011] A method for analyzing the carbon consumption of a water pump operating under power frequency conditions using a model is provided, including:

[0012] For a specified water pump, obtain real-time monitoring data of the flow rate during its operation under power frequency conditions;

[0013] Using a carbon consumption model for the design shaft power of the water pump under power frequency, which is corrected based on the shaft power-flow characteristic curve in the design state of the water pump, calculate the corresponding carbon consumption value; compare the calculation result with a set safety threshold. If there are more than a set number of deviation results within a specified time, it is considered that the water pump is in a continuously inefficient operation state, and a warning is issued to prompt an on-site inspection;

[0014] The carbon consumption model for the design shaft power of the water pump under power frequency is specifically as follows:

[0015] C D = K 当地对标 * N 轴

[0016] In the formula, C D is the carbon consumption of the design shaft power of the water pump under power frequency, K 当地对标 is the coal-electricity benchmarking coefficient for the corresponding region; N 轴 is the design shaft power of the water pump under power frequency.

[0017] As a preferred solution of the present invention, for the shaft power-flow characteristic curve of the water pump design state constructed by polynomial interpolation, multiply each coefficient in the polynomial by K 当地对标 respectively to obtain the corrected carbon consumption model for the design shaft power of the water pump under power frequency.

[0018] The present invention further provides a method for analyzing the carbon efficiency of a water pump operating under power frequency conditions using a model, including:

[0019] For a specified water pump, obtain real-time monitoring data of the flow rate Q and the head H during its operation under power frequency conditions;

[0020] Using the mechanical relative carbon efficiency model under power frequency design, calculate the corresponding carbon consumption value; compare the calculation result with a set safety threshold. If there are more than a set number of deviation results within a specified time, it is considered that the water pump is in a continuously inefficient operation state, and a warning is issued to prompt an on-site inspection;

[0021] The mechanical relative carbon efficiency model under power frequency design is specifically as follows:

[0022]

[0023] In the formula, η 相对碳效1 is the mechanical relative carbon efficiency under power frequency design; η 绝对碳效1is the carbon efficiency of the water pump operation under the power frequency condition; η 理论绝对碳效1 is the absolute carbon efficiency of the water pump corresponding to the design state corresponding to the actual operation flow rate, that is, the rated carbon efficiency when the water pump leaves the factory; K 当地对标 is the coal-electricity benchmarking coefficient for the corresponding region; ρ is the density of water; g is the acceleration due to gravity; Q is the water pump flow rate monitored in real time during the operation process; H is the water pump head monitored in real time during the operation process; N 电机 is the water pump motor power monitored in real time during the operation process; η 绝对能效1 is the comprehensive energy efficiency of the water pump; Q 设计 is the rated flow rate under the design condition; H 设计 is the design value of the head on the characteristic curve corresponding to the measured flow rate; N 电机设计 is the design value of the power on the characteristic curve corresponding to the measured flow rate and the corresponding motor.

[0024] The present invention also provides a method for analyzing the carbon efficiency of water pump operation under variable frequency conditions by using a model, including:

[0025] For a specified water pump, obtain the flow rate Q 运行 , head H 运行 and motor power N 电机运行 of the real-time monitoring data during the operation under variable frequency conditions;

[0026] Use the mechanical relative carbon efficiency model under variable frequency conditions to calculate the corresponding carbon consumption value; compare the calculation result with the set safety threshold. If there are more than the set number of deviation results within the specified time, it is considered that the water pump is in a continuous low-efficiency operation state, and a warning is issued to prompt on-site inspection;

[0027] The mechanical relative carbon efficiency model under variable frequency conditions is specifically as follows:

[0028]

[0029] In the formula, η 相对碳效2 is the mechanical relative carbon efficiency under variable frequency conditions; η 绝对碳效2 is the carbon efficiency of the water pump operation under variable frequency conditions; η 理论绝对碳效2 is the absolute carbon efficiency of the water pump corresponding to the design state corresponding to the actual operation flow rate, that is, the rated carbon efficiency when the water pump leaves the factory; K 当地对标 is the coal-electricity benchmarking coefficient for the corresponding region; ρ is the density of water; g is the acceleration due to gravity; Q 运行 is the water pump flow rate monitored in real time during the operation under variable frequency conditions; H 运行 is the water pump head monitored in real time during the operation under variable frequency conditions; N 电机运行 is the motor power monitored in real time during the operation under variable frequency conditions; η 绝对能效2 is the comprehensive energy efficiency of the water pump; Q 设计is the rated flow rate under the design condition; H 设计 is the design value of the head on the characteristic curve corresponding to the measured flow rate; N 电机设计 is the design value of the power on the characteristic curve corresponding to the measured flow rate and the corresponding motor.

[0030] As a preferred embodiment of the present invention, under the variable frequency operation condition, the corresponding Q of the water pump is measured 运行 and H 运行 After that, the following quadratic curve starting from the design characteristic curve of the water pump is obtained:

[0031] H 运行 = K 理论相似 Q 运行 2

[0032]

[0033] In the formula, K 理论相似 is the similarity coefficient corresponding to the specified water pump characteristic curve.

[0034] As a preferred embodiment of the present invention, the water pump refers to a single water pump or a water pump unit composed of a plurality of water pumps; the water pump is a centrifugal pump or an axial flow pump.

[0035] As a preferred embodiment of the present invention, each characteristic curve is a quartic polynomial obtained based on the interpolation method.

[0036] As a preferred embodiment of the present invention, the computer stores the calculated carbon consumption or carbon efficiency value and the monitoring data used for calculation in chronological order; while issuing a warning message on the display, the content of the warning message is recorded.

[0037] The present invention further provides a computer device, including: at least one processor, and a memory communicatively connected to the at least one processor, wherein the memory stores instructions executed by the at least one processor, and the instructions are executed by the at least one processor to enable the at least one processor to execute the method according to any one of claims 1 to 8.

[0038] The present invention also provides a computer-readable storage medium, and the computer-readable storage medium stores computer instructions for causing the computer to execute the method according to any one of claims 1 to 8.

[0039] Compared with the prior art, the beneficial effects of the present invention are:

[0040] 1. The present invention innovatively proposes to use a set model based on the characteristic curve of a water pump, which can calculate, analyze, and visually control the carbon consumption and carbon efficiency instantaneously with only individual water pump operation data. Therefore, it overcomes the limitation in the prior art that a large number of measured data such as flow rate, temperature, pressure, current, voltage, and operating power are required when calculating and analyzing based on operating power consumption and standard coal consumption.

[0041] 2. The concepts of absolute carbon efficiency and relative carbon efficiency proposed by the present invention cannot be achieved in the traditional carbon efficiency analysis system. It can comprehensively and visually analyze the carbon efficiency of water pumps in different operating states, including instant changes and historical trends, providing a theoretical basis and analysis method for the carbon efficiency management of water pumps. Detailed implementation mode

[0042] The following combines specific examples to elaborate on the implementation process of the present invention.

[0043] First of all, it should be noted that the following technical solutions of the present invention are applicable to both a specified single water pump and a water pump unit composed of a collection of multiple water pumps.

[0044] 1. Analyze the carbon consumption and carbon efficiency of water pump operation under power frequency conditions using a model

[0045] (1) Construct a carbon consumption model for the design state of a water pump applicable to power frequency operation conditions

[0046] For any specified water pump, under power frequency conditions, the hydraulic model based on the design corresponding specific speed conditions is deterministic. On this basis, through the similarity amplification theory, each corresponding water pump has its own set of corresponding design characteristic curves. Usually, this set of characteristic curves takes the flow rate corresponding to the water pump as the independent variable and includes four curves: head-flow rate (H-Q), shaft power-flow rate (N 轴 -Q), mechanical efficiency-flow rate (η 轴 -Q), and net positive suction head-flow rate (H 必须气蚀余量 -Q).

[0047] For a specified water pump, once the value of the flow rate is measured under power frequency conditions, starting from the above characteristic curves, the values of the operating head, operating shaft power, operating efficiency, and corresponding net positive suction head corresponding to the design state of the water pump under this operating condition can be intuitively determined within the corresponding accuracy range. On the one hand, it can be used as the basis for water pump state analysis, and on the other hand, it can be used as a verification system for measurement parameters.

[0048] Among them, the shaft power-flow rate curve is one of the main contents concerned by the present invention. For the current carbon consumption analysis, due to the very large differences in the composition of local power sources, there are coal-electricity benchmarking coefficients in each region of the country.

[0049] The present invention proposes the concept of the carbon consumption - flow characteristic curve of the pump's power - frequency design shaft work, and formulates an analysis model for pre - analyzing the carbon consumption in different working conditions for any pump, providing a theoretical basis for fundamentally changing the limitation of passive carbon consumption analysis.

[0050] First, define the carbon consumption model of the pump's power - frequency design shaft work as follows:

[0051] The carbon consumption of the pump's power - frequency design shaft work (C D ) = the coal - power benchmark coefficient (K 当地对标 ) of the corresponding region * the power - frequency design shaft power (N 轴 )

[0052] That is: C D = K 当地对标 * N 轴

[0053] The carbon consumption - flow characteristic curve of the pump's power - frequency design shaft work (C D - Q) is a direct extension of the power - flow curve (N 轴 - Q) of the given pump design state. That is, directly use the coal - power benchmark coefficient (K 当地对标 ) of the corresponding region to correct the power - flow curve (N 轴 - Q) of the design state. The independent variable is the corresponding flow rate Q. Multiply the dependent variable, the design - state shaft power corresponding to each flow rate, by the coal - power benchmark coefficient (K 当地对标 ) of the corresponding region and plot it in the graph. In this way, the carbon consumption - flow characteristic curve (C D - Q) of the pump's power - frequency design shaft work in the application area of the specified pump can be obtained. Of course, overall, if directly corresponding to standard coal, based on the above process, there will inevitably be a standard - coal carbon - consumption - flow curve that does not consider the power composition factors. This curve can be used as a special curve under the conditions of this model system. The significance of establishing this characteristic curve lies in that for a given pump, as long as there is a power - flow curve (N 轴 - Q) of the design state, the carbon consumption of the pump's power - frequency design shaft work under the specified flow conditions can be theoretically determined.

[0054] In the traditional analysis method, the numerical curve of the power - flow curve (N 轴 - Q) of the design state is constructed by using the method of polynomial interpolation. This polynomial is usually expressed in the following form. Taking a quartic curve as an example, there is:

[0055] N 轴 = a 轴 * Q 4 + b 轴 * Q 3 + c 轴 * Q 2 + d 轴*Q+e 轴

[0056] The parameters corresponding to pumps with different hydraulic models are different. Of course, during actual interpolation simulation, the polynomial degree and the selection of interpolation nodes will affect the parameters corresponding to this curve, but the error between this whole and the design curve is controllable. Or rather, for a specified pump, it is possible to simulate the program of the design state shaft power - flow curve (N 轴 -Q) curve, so that theoretically, the values of the corresponding design shaft power under different flow conditions can be continuously determined.

[0057] Still taking the quartic polynomial as an example, based on the above design state shaft power - flow curve (N 轴 -Q), the present invention proposes, based on the pump power - frequency design shaft work carbon consumption (C D ) model: the concept of the pump power - frequency design shaft work carbon consumption - flow characteristic curve (C D -Q). Corresponding to the pump power - frequency design shaft work carbon consumption (C D ) model and the quartic interpolation polynomial, it is proposed that:

[0058] C D =K 当地对标 *N 轴 =K 当地对标 *(a 轴 *Q 4 +b 轴 *Q 3 +c 轴 *Q 2 +d 轴 *Q+e 轴 )

[0059] The values of the coefficients a 轴 , b 轴 , c 轴 , d 轴 and e 轴 in the polynomial are related to the design curve given by the manufacturer. Rearranging the above formula gives:

[0060] C D =a 碳 *Q 4 +b 碳 *Q 3 +c 碳 *Q 2 +d 碳 *Q+e 碳

[0061] Thus, it is possible to construct an effective solution to quickly determine the design shaft work carbon consumption (C D)'s theoretical system. For interpolation polynomials of more than two times, within a given error range, this method can be directly applied. This is to specify the carbon consumption of the designed shaft work of the water pump (C D ) The concept and the basic content of its simulation analysis method are an effective extension of the traditional system. Based on the measured values corresponding to the flow rate, the operating carbon consumption of the water pump can be analyzed in real time, laying a theoretical foundation for its visual management and control.

[0062] In actual operation, for a specified water pump, obtain the real-time monitoring data of the flow rate during its operation under power frequency conditions; use the water pump power frequency designed shaft work carbon consumption model corrected based on the shaft power-flow characteristic curve of the water pump design state to calculate the corresponding carbon consumption value and display it on the monitor, and at the same time store this value and the monitoring data used for calculation in the computer synchronously according to the time sequence; compare the calculation result with the set safety threshold. If there are more than the set number of deviation results within the specified time, it is regarded that the water pump is in a continuous inefficient operation state, and a warning prompt is issued to require on-site inspection.

[0063] (2) Construct a carbon efficiency model for the design state of the water pump under power frequency operating conditions

[0064] The efficiency of the water pump has two levels: for the effective work, its efficiency curve is a description of the change law of the mechanical efficiency-flow rate (η 轴 -Q) in the water pump characteristic curve; for the shaft power, this efficiency represents the ability of the shaft power converted into the effective work of the water pump to achieve the outlet parameters of the water pump design state. For water pumps with different hydraulic models, the difference in this value is the basic basis for the reasonable selection of traditional water pumps. Correspondingly, the effective work of the water pump corresponds to a local carbon consumption, and the shaft power of the water pump corresponds to a local carbon consumption. The ratio of these two parameters can represent the effective conversion rate of the carbon consumption corresponding to the shaft work, that is, the mechanical carbon efficiency of the water pump.

[0065] The analysis of the mechanical carbon efficiency model of the water pump is as follows

[0066]

[0067] Through the above analysis, it can be concluded that the formulation of the mechanical carbon efficiency of the water pump is the same as the traditional shaft efficiency or mechanical efficiency value, but the meaning is completely different. The efficiency of the water pump itself is the mechanical efficiency, which refers to the part of the mechanical work of the water pump converted into the kinetic energy and static pressure head of the water. Therefore, the curve showing the change of power with the flow rate in the water pump characteristic curve refers to the mechanical power of the water pump, and only the mechanical carbon efficiency can be obtained from the water pump characteristic curve. If we want to discuss the overall efficiency of the water pump, we also need to introduce the motor and consider the motor efficiency of the motor converted into mechanical work.

[0068] When using the outlet and pipeline valve regulation to change the operating condition point of the water pump, based on the monitoring of the water pump process parameters and operating power parameters, the present invention further defines the absolute operating carbon efficiency value of the water pump as follows:

[0069]

[0070] Through the above formula derivation, the operating carbon efficiency η 绝对碳效1 of the water pump under the power frequency state and the comprehensive energy efficiency η 绝对能效1 of the water pump are numerically the same, but their meanings are completely different.

[0071] However, for the water pump, the simple absolute carbon efficiency is not sufficient to indicate the rationality of the carbon efficiency corresponding to the operating state of the water pump. The reason is that as the water pump operates, due to reasons such as blade wear, the operating condition of the water pump deviates from the design characteristic curve. For an operating water pump, the current is essentially another independent variable besides the flow rate. However, since the operating voltage is often not the design voltage and the motor characteristic curve is generally not provided by the manufacturer, the characteristics of the water pump can only be deduced by measuring the head under insufficient intuitive conditions. This physical loss of wear nature will cause the characteristic curve to drift. Therefore, it is necessary to propose a relative carbon efficiency model for the water pump under the power frequency condition. When the actually monitored flow rate and head parameters are within a sufficient accuracy range, how much the corresponding carbon consumption deviates from the design value is calculated according to the following relative energy efficiency model:

[0072]

[0073] The meaning of this formula is the degree to which the absolute carbon efficiency of the water pump under the actual operating conditions deviates from the theoretical absolute carbon efficiency of this operating condition. Among them, η 理论绝对碳效 is the absolute carbon efficiency corresponding to the water pump under the design state corresponding to the actual operating flow rate (i.e., the rated carbon efficiency when the water pump leaves the factory), and the overall calculation formula also adopts:

[0074]

[0075] In the above formulas: η 相对碳效1 is the relative mechanical carbon efficiency of the power frequency design; η 绝对碳效1 is the operating carbon efficiency of the water pump under the power frequency state; η 理论绝对碳效1 is the absolute carbon efficiency corresponding to the water pump under the design state corresponding to the actual operating flow rate, that is, the rated carbon efficiency when the water pump leaves the factory; K 当地对标 is the coal-electricity benchmarking coefficient for the corresponding region; ρ is the density of water; g is the acceleration due to gravity; Q is the flow rate of the water pump monitored in real time during operation; H is the head of the water pump monitored in real time during operation; N 电机 is the power of the water pump motor monitored in real time during operation; η 绝对能效1 is the comprehensive energy efficiency of the water pump; Q 设计 is the rated flow rate under the design condition; H设计 is the design value of the head on the characteristic curve corresponding to the measured flow rate; N 电机设计 is the design value of the power under the characteristic curve corresponding to the measured flow rate and the corresponding motor.

[0076] For a water pump, the flow rate is the first independent variable in the analysis of the entire system. As the operation of the water pump continues, various reasons may cause deviations in the characteristics of the water pump. This deviation is manifested as the difference between the measured head and the designed head under the given flow rate condition. The visualization monitoring and analysis method of this difference is prior art, and the specific content can be referred to the records in the published literature (such as Chinese Patent CN113536710B).

[0077] In summary, for the deviations caused by various reasons, the concept of relative carbon efficiency is proposed from the perspective of analysis:

[0078]

[0079] During the actual operation process, once the flow rate and head of the water pump under the corresponding working conditions are measured according to the traditional system, the absolute carbon efficiency and relative carbon efficiency of the water pump operation can be intuitively displayed according to the model in the above formula, which is the data lacking in the traditional method. The absolute carbon efficiency can directly display the conversion efficiency of unit electric energy into carbon emissions, while the relative carbon efficiency directly shows the degree of deviation of the carbon efficiency of the given water pump operation from the designed working conditions. This cannot be achieved by the traditional water pump monitoring system. Based on this model, the digitalization and experience visualization of the utility engineering in the process industry are supported by the visualized data.

[0080] In actual application, for a specified water pump, obtain the real-time monitoring data of the flow rate Q and head H during its operation under industrial frequency conditions; calculate the corresponding carbon consumption value using the mechanical relative carbon efficiency model under industrial frequency design and display it on the monitor, and at the same time store the value and the monitoring data used for calculation in the computer synchronously according to the time sequence; compare the calculation result with the set safety threshold. If there are more than the set number of deviation results within the specified time, it is regarded that the water pump is in a continuously inefficient operation state, and a warning prompt is issued to require on-site inspection.

[0081] 2. Analyze the carbon efficiency of water pump operation under variable frequency conditions using the model

[0082] First, construct a carbon consumption model for the water pump applicable to variable frequency operation conditions.

[0083] When the water pump is operating, the optimal adjustment method is the variable frequency method. For the same given water pump, the operating characteristics of the water pump are different under different rotational speed conditions. It is necessary to provide a programmed method for analyzing the similar working conditions under variable frequency, so as to realize the visual monitoring and analysis of the carbon efficiency of the water pump operation under variable frequency speed regulation conditions.

[0084] Under such conditions, it is first necessary to measure the operating flow rate Q 运行 .

[0085] According to the similarity theorem, when a given water pump operates with variable frequency speed regulation, there is a corresponding similar operating point for each design operating point under different rotational speed conditions. A large amount of experience shows that for a given pump set, under different rotational speed conditions, the flow rate is proportional to the rotational speed. Therefore, for the series of node design flow rates Q 设计 on the given characteristic curve, the corresponding similar flow rate values are:

[0086]

[0087] In the above formula:

[0088] n 设计 —— The rated rotational speed of the given water pump; n 运行 —— The actual rotational speed of the given water pump.

[0089] For any given water pump, the characteristic curve is drawn by measuring and obtaining the values of the flow rate and the corresponding head at a series of nodes. Starting from the similarity theory, for the rated operating point (Q 设计 , H 设计 ) of the given water pump, all the similar points at different rotational speeds are one-to-one corresponding similar points starting from this point. That is, for each given design operating point, there will be a similar curve that satisfies the value of the similarity coefficient:

[0090]

[0091] In the formula: K 理论相似 —— The similarity coefficient corresponding to the characteristic curve of the specified water pump.

[0092] Once the characteristic curve is given, each different node has its own similarity coefficient. Therefore, for the nodes on the rated characteristic curve, the theoretical or design characteristic curve under the corresponding rotational speed value conditions can be found. Based on the actually measured flow rate and the corresponding rotational speed, the theoretical similar head at the corresponding operating point can be found. For calculation, the power frequency characteristic curve can be expressed as a corresponding polynomial by using the interpolation fitting method under certain accuracy conditions. Different manufacturers have different characteristic curves, and this needs to be numerically simulated based on the interpolation method according to the characteristic curve of the water pump. For example, the expressions for the corresponding head and flow rate can be expressed by a fourth-degree polynomial, that is, for a certain given water pump:

[0093] H 设计 =a 扬程 Q 设计 4 +b 扬程 Q 设计 3 +c 扬程 Q设计 2 +d 扬程 Q 设计 +e 扬程

[0094] The coefficients a 扬程 , b 扬程 , c 扬程 , d 扬程 and e 扬程 in the polynomial are related to the characteristic curves given by different manufacturers. Once the water pump is measured and the flow rate Q 运行 at a certain rotational speed is obtained, then the designed flow rate corresponding to the power frequency is:

[0095]

[0096] The corresponding set head value can be calculated by an approximate polynomial, that is:

[0097] H 设计 = a 扬程 Q 设计 4 + b 扬程 Q 设计 3 + c 扬程 Q 设计 2 + d 扬程 Q 设计 + e 扬程

[0098] Theoretically, the similarity coefficients corresponding to the designed operating points (Q 设计 , H 设计 ) and (Q 运行 , H 运行 ) are:

[0099]

[0100] Under the actual on-site operating conditions, for newly manufactured water pumps, starting from the designed characteristic curve based on the above formula, once the (Q 运行 , H 运行 ) corresponding to the variable-frequency operating condition is measured, the quadratic curve starting from the origin on the characteristic curve is theoretically:

[0101] H 运行 = K 理论相似 Q 运行 2

[0102] The intersection point of this quadratic curve and the following curve is the theoretical similarity point (Q 运行 , H 运行 ) of the actual operating point (Q 设计 , H设计 ):

[0103] H 设计 = a 扬程 Q 设计 4 + b 扬程 Q 设计 3 + c 扬程 Q 设计 2 + d 扬程 Q 设计 + e 扬程

[0104] According to the similarity theory, for the (Q 运行 , H 运行 ) corresponding to the variable-frequency operation condition of a newly manufactured water pump:

[0105]

[0106] Actually, during the continuous operation of the water pump, due to reasons such as cavitation and mechanical wear, whether measuring Q 运行 alone or measuring H 运行 alone, the corresponding actual operating condition point must deviate from the theoretical value state of the newly manufactured one. Then, for the on-site state of simultaneously measuring Q 运行 , H 运行 and N 电机运行 , the following model is used to directly calculate the absolute carbon efficiency of the corresponding variable-frequency operating condition point:

[0107]

[0108] At this time, the relative change degree of the carbon efficiency caused by the corresponding deviation is visually analyzed by the following formula:

[0109]

[0110] In the above formulas, η 相对碳效2 is the mechanical relative carbon efficiency of the variable-frequency operating condition; η 绝对碳效2 is the carbon efficiency of the water pump operation under the variable-frequency operating condition; η 理论绝对碳效2 is the absolute carbon efficiency corresponding to the water pump under the designed state corresponding to the actual operating flow rate, that is, the rated carbon efficiency when the water pump leaves the factory; K 当地对标 is the coal-electricity benchmarking coefficient for the corresponding region; ρ is the density of water; g is the acceleration of gravity; Q 运行 is the water pump flow rate monitored in real time during the variable-frequency operation process; H 运行 is the water pump head monitored in real time during the variable-frequency operation process; N 电机运行 is the water pump motor power monitored in real time during the variable-frequency operation process; η 绝对能效2 is the comprehensive energy efficiency of the water pump; Q设计 is the rated flow rate under the design condition; H 设计 is the design value of the head on the characteristic curve corresponding to the measured flow rate; N 电机设计 is the design value of the power on the characteristic curve corresponding to the measured flow rate and the corresponding motor.

[0111] During actual operation, for a specified water pump, obtain the flow rate Q 运行 , head H 运行 and the real-time monitoring data of the motor operating power N 电机运行 ; use the mechanical relative carbon efficiency model under the variable frequency condition to calculate the corresponding carbon consumption value and display it on the monitor, and at the same time store the value and the monitoring data used for calculation in the computer synchronously according to the time sequence; compare the calculation result with the set safety threshold. If there are more than the set number of deviation results within the specified time, it is considered that the water pump is in a continuous low-efficiency operation state, and a warning is issued to prompt on-site inspection.

[0112] 3. The above content describes how the present invention specifically constructs the model and uses it to analyze the carbon consumption and carbon efficiency of the water pump operation under the power frequency and variable frequency conditions. Those skilled in the art can understand that the above method can run these models in a computer system based on software programming. For this reason, the present invention further provides a corresponding computer device and a computer-readable storage medium for storing and running the method of the present invention implemented in the form of a computer program.

[0113] Among them, the computer device includes: at least one processor, and a memory communicatively connected to at least one processor, wherein the memory stores instructions executed by at least one processor, and the instructions are executed by at least one processor to enable the at least one processor to execute the foregoing method. The computer-readable storage medium stores computer instructions, and the computer instructions are used to cause the computer to execute the method. The specific implementation method can be realized by those skilled in the art according to the skills they master, and the present invention will not be elaborated.

[0114] 4. Specific application examples

[0115] For the water cooling tower equipment area of a thermal power plant, all centrifugal pumps, axial flow pumps or pump sets in this area are selected as the monitoring objects. Under power frequency or variable frequency conditions, the deviation safety value of the relative carbon efficiency model of each pump and pump set is set to 90%, and the continuous deviation value is set to 30% (the deviation safety value refers to the amplitude of deviation from the safety threshold, and the continuous deviation value refers to the proportion of the results of deviation from the safety threshold in all calculation results within the specified time). Monitor the data of the pumps and pump sets under 20 different working conditions within the set continuous time period, and based on these data, calculate and analyze the relative carbon efficiency model to obtain the data of carbon consumption and carbon efficiency. When more than 6 relative carbon efficiency model data in the collected samples are lower than 90%, it indicates that the changes in carbon consumption and carbon efficiency are not simply caused by changes in operating conditions, but there are problems with the hardware of the pumps and pump sets themselves or the pipelines where they are located. At this time, the computer needs to send a warning to the technical personnel through the human-machine interface and record the content of the warning information; the on-site staff should promptly check the equipment status to avoid the continuous inefficient operation of the pumps and pump sets and further deterioration.

Claims

1. A method for analyzing the carbon consumption of a water pump under power frequency conditions using a model, characterized in that: include: For a specified water pump, obtain real-time monitoring data of its flow rate during operation under power frequency conditions; The corresponding carbon consumption value is calculated using the pump power frequency design shaft power carbon consumption model based on the pump design state shaft power-flow characteristic curve correction; the calculated result is compared with the set safety threshold. If the deviation results exceed the set number within the specified time, the pump is considered to be in a state of continuous inefficient operation, and a warning is issued to prompt an on-site inspection; The specific carbon consumption model of the shaft power of the water pump in power frequency design is as follows: C D =K 当地对标 *N 轴 In the formula, C D K is the carbon consumption of the shaft power designed for the pump at working frequency. 当地对标 N is the coal-fired power benchmarking coefficient of the corresponding region; 轴 Design shaft power for the pump at industrial frequency.

2. The method according to claim 1, characterized in that For the pump design state shaft power-flow characteristic curve constructed by polynomial interpolation, K 当地对标 Multiply each coefficient in the polynomial respectively to obtain the revised pump power frequency design shaft power carbon consumption model.

3. A method for analyzing the carbon efficiency of water pump operation under power frequency conditions using a model, characterized in that: include: For a specified water pump, obtain real-time monitoring data of flow rate Q and head H during its operation under power frequency conditions; The relative carbon efficiency model of the machine is designed using the power frequency to calculate the corresponding carbon consumption value, and the calculated result is compared with the set safety threshold. If the deviation exceeds the set number within the specified time, it is considered that the pump is in a state of continuous inefficient operation, and a warning is issued to prompt an on-site inspection; The relative carbon efficiency model of the power frequency design machinery is as follows: In the formula, Design mechanical relative carbon efficiency for industrial frequency; It is the carbon efficiency of the pump under the working frequency state; K is the absolute carbon efficiency of the pump under the design state corresponding to the actual operating flow, that is, the rated carbon efficiency of the pump when it leaves the factory; 当地对标 is the benchmark coefficient of coal-fired power in the corresponding region; ρ is the density of water; g is the acceleration of gravity; Q is the water pump flow rate monitored in real time during operation; H is the water pump head monitored in real time during operation; N 电机 It is the water pump motor power monitored in real time during operation; is the comprehensive energy efficiency of the water pump; Q 设计 is the rated flow rate under design conditions; H 设计 It is the design value of the head on the characteristic curve corresponding to the measured flow rate; N 电机设计 It is the design value of the characteristic curve corresponding to the measured flow rate and the corresponding motor power.

4. A method for analyzing the carbon efficiency of water pump operation under variable frequency conditions using a model, characterized in that: include: For a specified water pump, obtain its flow rate Q during operation under variable frequency conditions 运行 , Lift H 运行 And motor power N 电机运行 Real-time monitoring data; The relative carbon efficiency model of variable frequency mechanical operation is used to calculate the corresponding carbon consumption value, and the calculated result is compared with the set safety threshold. If the deviation exceeds the set number within the specified time, it is considered that the pump is in a state of continuous inefficient operation, and a warning is issued to prompt an on-site inspection; The relative carbon efficiency model of the variable frequency working condition machinery is as follows: In the formula, The relative carbon efficiency of the machine under variable frequency operation; It is the carbon efficiency of the water pump under variable frequency working condition; K is the absolute carbon efficiency of the pump under the design state corresponding to the actual operating flow, that is, the rated carbon efficiency of the pump when it leaves the factory; 当地对标 is the benchmark coefficient of coal-fired power in the corresponding region; ρ is the density of water; g is the acceleration of gravity; Q 运行 It is the water pump flow rate monitored in real time during the variable frequency operation; H 运行 It is the pump head monitored in real time during the variable frequency operation process; N 电机运行 It is the motor power monitored in real time during the variable frequency operation process; is the comprehensive energy efficiency of the water pump; Q 设计 is the rated flow rate under design conditions; H 设计 It is the design value of the head on the characteristic curve corresponding to the measured flow rate; N 电机设计 It is the design value of the characteristic curve corresponding to the measured flow rate and the corresponding motor power.

5. The method according to claim 4, characterized in that Determine the Q corresponding to the pump under variable frequency operation conditions 运行 and H 运行 After that, the quadratic curve based on the pump design characteristic curve is as follows: H 运行 =K 理论相似 Q 运行 2 In the formula, K 理论相似 The similarity coefficient corresponding to the specified pump characteristic curve.

6. The method according to any one of claims 1 to 5, characterized in that The water pump refers to a single water pump, or a water pump unit composed of a plurality of water pumps; the water pump is a centrifugal pump or an axial flow pump.

7. The method according to any one of claims 1 to 5, characterized in that Each characteristic curve is a fourth-order polynomial obtained based on an interpolation method.

8. The method according to any one of claims 1 to 5, characterized in that The computer stores the calculated carbon consumption or carbon efficiency values ​​and the monitoring data used for calculation in time sequence; while issuing a warning message on the display, the content of the warning message is recorded.

9. A computer device, characterized in that: include: At least one processor, and a memory communicatively connected to the at least one processor, wherein the memory stores instructions executed by the at least one processor, and the instructions are executed by the at least one processor so that the at least one processor executes the method according to any one of claims 1 to 8.

10. A computer-readable storage medium, characterized in that: The computer-readable storage medium stores computer instructions, and the computer instructions are used to enable the computer to execute the method according to any one of claims 1 to 8.

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