阅读说明：本技术 一种同型号调速泵泵站节能运行的优化方法 (Energy-saving operation optimization method for speed regulating pump stations of same type ) 是由 白妙顺 于 2020-12-31 设计创作，主要内容包括：本发明提供了一种同型号调速泵泵站节能运行的优化方法,步骤为：拟合水泵流量-扬程关系式和流量-效率关系式；确定泵站出水优化目标；基于目标流量、压力计算最小开泵数；确定最优开泵台数及调速泵转速。本发明可快速、高效地确定泵站内水泵的最优开泵方案,从而使运行费用最低,有效指导泵站运行调度。(The invention provides an optimization method for energy-saving operation of speed regulating pump stations of the same type, which comprises the following steps: fitting a relation of water pump flow-lift and a relation of flow-efficiency; determining a pump station water outlet optimization target; calculating the minimum pump opening number based on the target flow and the pressure; and determining the optimal number of the pumps and the rotating speed of the speed regulating pump. The method can quickly and efficiently determine the optimal pump starting scheme of the water pump in the pump station, thereby minimizing the operation cost and effectively guiding the operation and scheduling of the pump station.)

1. An optimization method for energy-saving operation of speed regulating pump stations of the same type comprises the following steps:

step 1) fitting a relation of water pump flow-lift and a relation of flow-efficiency;

step 2), determining a pump station water outlet optimization target;

step 3) calculating the minimum pump opening number based on the target flow and the pressure;

and 4) determining the optimal number of the pumps and the rotating speed of the speed regulating pump.

2. The optimization method for the energy-saving operation of the speed regulating pump station with the same model according to claim 1, wherein the step 1) is as follows: fitting a water pump flow-lift relation and a flow-efficiency relation to obtain sample curve data, or fitting a binomial equation based on historical operating data to obtain a flow-lift unitary quadratic equation H ═ a_hQ²+b_hQ+c_hAnd the one-dimensional quadratic equation eta of flow-efficiency is a_ηQ²+b_ηQ+c_η。

3. The optimization method for the energy-saving operation of the speed regulating pump station with the same model according to claim 1, wherein the step 2) is as follows: determining the optimal target of pump station water outlet and obtaining the real-time data pump station water inlet pressure P_inWater flow Q_outPressure of water discharge P_out；

a. When the water outlet flow Q is set_objWhen the water is fed into the water tank, the target water inlet pressure P is set_inPressure of water discharge P_outAnd set water outlet flow Q_out＝Q_objAs an optimization objective;

b. when the water outlet pressure P is set_objIn time, the real-time water inlet pressure P_inWater flow Q_outAnd setting the water outlet pressure P_out＝P_objAs an optimization objective;

c. when setting the control point pressure P_cIn time, the real-time water inlet pressure P_inWater flow Q_outCalculating the water pressure P against the control point_out＝P_c+a_sQ²+b_sQ+c_sAs an optimization target, wherein P_cTo control the point pressure, a_s、b_s、c_sIs the pipeline system characteristic coefficient.

4. The optimization method for the energy-saving operation of the speed regulating pump station with the same model according to claim 1, wherein the step 3) is as follows: based on target flowCalculating the minimum pump opening number through pressure, and calculating the water pump lift H (P) through the inlet and outlet target pressure difference_out-P_inCalculating the rated speed and flow of the single pump under the current head based on the flow-head equation

a. When no constant speed pump exists, the minimum number of the water pumps is as follows:the ratio of the water outlet flow to the rated flow of the single pump is rounded upwards; or

b. When the constant speed pump exists, deducting the number N of the opened constant speed pumps_StatorAnd corresponding flow N_StatorQ_eThe minimum number of pumps isThe flow rate of the single pump of the speed regulating pump is

5. The optimization method for the energy-saving operation of the speed regulating pump station with the same model according to claim 1, wherein the step 4) is as follows: determining the optimal number of the pumps and the rotating speed of a speed regulating pump; namely: from the minimum number of pumps on, the flow rate Q of a single pump_iLift H_iBased on the equivalent similarity theorem of variable frequency speed regulation of the water pump and the flow-lift equation, the rotation speed ratio s is calculated_iSingle pump flow rate and maximum efficiency point flow rateAnd (4) comparing, judging whether the pump is optimal or not, if so, outputting the optimal pump starting number and the corresponding rotating speed, otherwise, increasing the pump starting number by 1, and repeating the step 4 until the maximum pump starting number.

6. The method for optimizing the energy-saving operation of the speed regulating pump station with the same model according to claim 5, wherein the step 4) is specifically as follows:

a. given a maximum number of pumps N_maxMinimum rotation speed ratio s_minThe number of the current pumps N is equal to N_minInitializing the optimal scheme, and the optimal number of pumps N_opt＝N_minOptimum speed ratio s_opt1, optimum efficiency η_opt＝0；

b. Single pump flow Q_i＝Q_outN, single pump head H_i＝H；

c. Based on the equivalent similarity theorem of water pump speed regulation, the rotating speed is n_iTo a rated speed n_eLower lift H_iFlow rate Q_iRatio of rotation to speed s_iThe relationship is as follows:

substituting into the flow-lift equation to obtain

H_i＝a_hQ_i ²+b_hs_iQ_i+c_hs_i ²，

To obtain

d. Judgment s_i＜s_minIf yes, performing the step h, otherwise, performing the next step;

e. calculating current efficiency

f. Judgment of eta_i＞η_optIf yes, the optimal pump opening number N_optN, optimum speed ratio s_opt＝s_iOptimum efficiency η_opt＝η_i(ii) a Otherwise, carrying out the next step;

g. single pump flow rate Q_iAnd point of maximum efficiencyContrast and judgeOr N ═ N_maxIf yes, performing step h, otherwise, performing step b if N is equal to N + 1;

h. outputting the optimal scheme and the optimal number of pumps N_optOptimum speed ratio s_optOptimum efficiency η_opt。

Technical Field

The invention relates to operation scheduling of water pumps. In particular to a rapid optimization scheduling method for energy-saving operation of a pump station.

Background

In industrial and agricultural production and various occasions of resident life, a large number of water pumps are adopted for lifting or pressurizing fluid, wherein a plurality of water pumps with the same type are connected in parallel in a pump station, and a frequency converter is additionally arranged for regulating the speed of the water pumps, so that the aim of saving energy can be fulfilled.

Under different operating conditions, there are often different combinations of water pumps to meet the operating conditions, and there is an optimal energy-saving water pump operating combination scheme for the operating conditions of the water pumps at different speeds in each different combination of the schemes.

At present, some achievements have been made on the research of pump station combination optimization, and there are conventional methods for enumerating all combination schemes that can meet the operation conditions and selecting the optimal scheme from them, and there are also pump station optimization schedules for obtaining the optimal solution based on intelligent algorithms such as genetic algorithm, ant colony algorithm, particle swarm algorithm, and the like. The method has wide application range, but has the defects of large calculation amount and low working efficiency because enumeration combination and iterative calculation are required.

Disclosure of Invention

The invention aims to provide a quick optimization scheduling method for energy-saving operation of speed-regulating pump stations of the same type, which can quickly determine an optimal pump starting scheme of a water pump in a pump station according to parameters such as flow, lift and efficiency of the water pump and the constraint conditions such as the maximum working water pump quantity, the variable frequency water pump quantity, the minimum rotating speed and the maximum rotating speed of the water pump operation range, so that the operation cost is lowest. By utilizing the characteristics of the water pump flow-lift relation and the unitary quadratic equation extremum of the flow-efficiency relation, the speed regulating pump equivalent principle and the hydraulic characteristics of the pump station, the optimal pump starting scheme can be efficiently and quickly obtained.

In order to achieve the purpose, the technical scheme of the optimization method for the energy-saving operation of the speed regulating pump station with the same model is as follows:

an optimization method for energy-saving operation of speed regulating pump stations of the same type comprises the following steps:

step 1) fitting a relation between water pump flow and lift and a relation between flow and efficiency;

step 2), determining a pump station water outlet optimization target;

step 3) calculating the minimum pump opening number based on the target flow and the pressure;

and 4) determining the optimal number of the pumps and the rotating speed of the speed regulating pump.

Further, the method of step 1) is as follows:

fitting a relation between the flow and the lift of the water pump and a relation between the flow and the efficiency to obtain sample curve data, or fitting a binomial equation based on historical operating data to obtain a unitary quadratic equation H (a) between the flow and the lift_hQ²+b_hQ+c_hAnd the one-dimensional quadratic equation eta of flow-efficiency is a_ηQ²+b_ηQ+c_η。

Further, the method of step 2) is:

determining the optimal target of pump station water outlet and obtaining the real-time data pump station water inlet pressure P_inWater flow Q_outPressure of water discharge P_out；

a. When the water outlet flow Q is set_objWhen the water is fed into the water tank, the target water inlet pressure P is set_inPressure of water discharge P_outAnd set water outlet flow Q_out＝Q_objAs an optimization objective;

b. when the water outlet pressure P is set_objIn time, the real-time water inlet pressure P_inWater flow Q_outAnd setting the water outlet pressure P_out＝P_objAs an optimization objective;

c. when setting the control point pressure P_cIn time, the real-time water inlet pressure P_inWater flow Q_outCalculating the water pressure P against the control point_out＝P_c+a_sQ²+b_sQ+c_sAs an optimization target, wherein P_cTo control the point pressure, a_s、b_s、c_sIs the pipeline system characteristic coefficient.

Further, the method in step 3) is as follows:

calculating the minimum pump opening number based on the target flow and pressure, wherein the pump head H (P) is calculated by the inlet and outlet target pressure difference_out-P_inCalculating the rated speed and flow of the single pump under the current lift based on the flow-lift equation

a. When there is no constant speed pump, the minimum number of pumps of water pumpThe ratio of the water outlet flow to the rated flow of the single pump is rounded upwards; or

b. When the constant speed pump exists, deducting the number N of the opened constant speed pumps_StatorAnd corresponding flow N_StatorQ_eThe minimum number of pumps is

The flow rate of the single pump of the speed regulating pump is

Further, the method of step 4) is:

determining the optimal number of the pumps and the rotating speed of the speed regulating pump, namely: from the minimum number of pumps on, the flow rate Q of a single pump_iLift H_iBased on the equivalent similarity theorem of variable frequency speed regulation of the water pump and the flow-lift equation, the rotation speed ratio s is calculated_iSingle pump flow rate and maximum efficiency point flow rateAnd (4) comparing, judging whether the pump is optimal or not, if so, outputting the optimal pump starting number and the corresponding rotating speed, otherwise, increasing the pump starting number by 1, and repeating the step 4 until the maximum pump starting number.

Further, the step 4) is specifically as follows:

a. given a maximum number of pumps N_maxMinimum rotation speed ratio s_minThe number of the current pumps N is equal to N_minInitializing the optimal scheme, and the optimal number of pumps N_opt＝N_minOptimum speed ratio s_opt1, optimum efficiency η_opt＝0；

b. Single pump flow Q_i＝Q_outN, single pump head H_i＝H；

c. Based on the equivalent similarity theorem of water pump speed regulation, the rotating speed is n_iTo a rated speed n_eLower lift H_iFlow rate Q_iRatio of rotation to speed s_iThe relationship isSubstituting into flow-lift equation to obtain H_i＝a_hQ_i ²+b_hs_iQ_i+c_hs_i ²Obtaining

d. Judgment s_i＜s_minIf yes, performing the step h, otherwise, performing the next step;

e. calculating current efficiency

f. Judgment of eta_i＞η_optIf yes, the optimal pump opening number N_optN, optimum speed ratio s_opt＝s_iOptimum efficiency η_opt＝η_i(ii) a Otherwise, carrying out the next step;

g. single pump flow rate Q_iAnd point of maximum efficiencyContrast and judgeOr N ═ N_maxIf yes, performing step h, otherwise, performing step b if N is equal to N + 1;

h. outputting the optimal scheme and the optimal number of pumps N_optOptimum speed ratio s_optOptimum efficiency η_opt。

The invention provides an optimization method for energy-saving operation of speed regulating pump stations of the same type, which has the following beneficial effects:

(1) the method is suitable for the lifting pump station with definite water outlet flow or pressure target and definite control target; all feasible water pump operation combination schemes are quickly screened out according to the actual operation working conditions, the energy consumption of the feasible water pump operation combination schemes is analyzed, the optimized water pump energy-saving operation combination scheme is further obtained, and therefore the most economical water pump operation combination scheme under the actual operation working conditions is selected.

(2) The method of the invention can quickly obtain the optimal solution without enumeration combination and iterative computation: ratio of rotational speeds s_iThe calculation of (2) is directly solved according to the characteristics of a unitary and quadratic mode without iterative calculation; the optimal pump starting combination is judged according to the most efficient point of the efficiency curve, and all pump starting combinations do not need to be enumerated for sequencing, so that the calculation efficiency is greatly improved.

(3) The method is a high-real-time, efficient and economic water pump operation optimization method, can directly obtain the optimal pump starting scheme for determining the operation of the pump station under the target, can also be embedded into iterative calculation of complex system optimization problems such as multi-water source and multi-stage pressurization, and can be widely applied to the industries such as municipal administration, water conservancy, petrochemical industry and the like.

Drawings

FIG. 1 is a schematic flow chart of an optimization method for energy-saving operation of speed regulating pump stations of the same type;

fig. 2 is a graph of water pump characteristics.

Detailed Description

The following will further describe in detail the optimization method for energy-saving operation of the speed-regulating pump station of the same model.

In order to make the objects and features of the present invention more comprehensible, embodiments of the present invention are described in detail below with reference to the accompanying drawings and examples.

Example 1

The invention provides an optimization method for energy-saving operation of speed regulating pump stations of the same type, which comprises the following specific steps as shown in figure 1:

step 1, fitting a relation between flow and lift of a water pump and a relation between flow and efficiency to obtain sample curve data, or fitting a binomial equation based on historical operation data to obtain a unitary quadratic equation H ═ a between flow and lift_hQ²+b_hQ+c_hAnd the one-dimensional quadratic equation eta of flow-efficiency is a_ηQ²+b_ηQ+c_ηLet each coefficient be a_h＝-10，b_h＝5，c_h＝30，a_η＝-100，b_η＝180，c_η＝20

Step 2, determining a pump station water outlet optimization target, and acquiring real-time data pump station water inlet pressure P_in5m, water outlet flow Q_out＝3m³S, water outlet pressure P_out24m, operating in a mode of setting the water outlet pressure;

when the water outlet pressure P is set_objWhen the water is 25m, the real-time water inlet pressure P is measured_in5m, water outlet flow Q_out＝3m³S and set water outlet pressure P_out＝P_obj25m as optimization target;

and 3, calculating the minimum pump opening number based on the target flow and the pressure, and calculating the water pump lift H (P) through the inlet and outlet target pressure difference_out-P_inAnd (5) calculating the rated rotating speed and flow of the single pump under the current head based on the flow-head equation (25-5-20 m)

When there is no constant speed pump, the minimum number of pumps of water pumpThe ratio of the water outlet flow to the rated flow of the single pump is rounded upwards;

when the constant-speed pump does not exist, the flow of the single pump of the speed-regulating pump is set as

Step 4, determining the optimal number of the pumps and the rotating speed of the speed regulating pump;

given a maximum number of pumps N_max6, minimum speed ratio s_min0.5, the current number of pumps on N is N_minInitializing the optimal scheme and the optimal pump number N as 3_opt＝N_minOptimum speed ratio s of 3_opt1, optimum efficiency η_opt＝0；

Flow rate of single pumpSingle pump head H_i＝H＝20m；

Based on the equivalent similarity theorem of water pump speed regulation, the rotating speed is n_iTo a rated speed n_eLower lift H_iFlow rate Q_iRatio of rotation to speed s_iThe relationship isSubstituting into flow-lift equation to obtain H_i＝a_hQ_i ²+b_hs_iQ_i+c_hs_i ²Obtaining

Judgment s_i＝0.92＜s_minIf not, the next step is carried out;

calculating current efficiency

Judgment of eta_i＝87.5％＞η_optWhen 0, the optimum number of pumps N is satisfied_optN-3, optimum speed ratio s_opt＝s_i0.92, optimum efficiency η_opt＝η_i＝87.5％；

Single pump flow rate Q_i1 and point of maximum efficiencyContrast and judgeOr N-3-N_maxIf not, N +1 + 3+1 + 4;

flow rate of single pumpSingle pump head H_i＝h＝20M；

Based on the equivalent similarity theorem of water pump speed regulation, the rotating speed is n_iTo a rated speed n_eLower lift H_iFlow rate Q_iRatio of rotation to speed s_iThe relationship isSubstituting into flow-lift equation to obtain H_i＝a_hQ_i ²+b_hs_iQ_i+c_hs_i ²Obtaining

Judgment s_i＝0.864＜s_minIf not, the next step is carried out;

calculating current efficiency

Judgment of eta_i＝90.9％＞η_opt87.5%, the optimum number of pumps N is satisfied_optN4, optimum speed ratio s_opt＝s_i0.864, optimum efficiency η_opt＝η_i＝90.9％；

Single pump flow rate Q_i0.75 and maximum efficiency pointContrast and judgeOr N4N_max6, true;

outputting the optimal scheme and the optimal number of pumps N_opt4, optimum speed ratio s_opt0.864, optimum efficiency η_opt＝90.9％；

Fig. 2 is a water pump characteristic graph including: (a) a flow-head curve, and (b) a flow-efficiency curve.

The above-mentioned embodiments are merely illustrative of the preferred embodiments of the present invention, and do not limit the scope of the present invention, and various modifications and improvements of the technical solution of the present invention by those skilled in the art should fall within the protection scope defined by the claims of the present invention without departing from the spirit of the present invention.