Optimized operation method for irrigation water replenishing pump station in large-scale irrigation area

Abstract

The invention discloses an optimized operation method for an irrigation and water supplement pump station in a large-scale irrigation area. The method comprises the following steps: S1, collecting planting types of the irrigation area, planting areas of crops, average gross irrigation amount per mu, time-of-use electricity prices and duration of different time-of-use electricity prices; collecting the water quantity which can be provided by the canal head of the irrigation area, and determining the required water lifting and supplementing water quantity; s2, dispersing the blade placement angle of each water pump, and determining the starting flow and efficiency of each water pump at different blade placement angles in combination with the water lift under the condition that the blade placement angle is determined; s3, according to the water replenishing quantity requirement, the minimum water replenishing cost in the one-time water replenishing process serves as an objective function, the total water replenishing quantity and the water pump power serve as constraint conditions, and a water replenishing pump station starting-up mode optimization model is established; and S4, setting the placement angle of each water pump blade to be unchanged all the time, and determining the placement angle of each water pump blade in the starting process. According to the method, the peak-valley electricity price is combined to correspondingly adjust different blade setting angles of the water replenishing pump station, and the water lifting cost of the water replenishing pump station can be effectively reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of irrigation district optimization planning, and in particular to a method for optimizing the operation of an irrigation water replenishment pump station in a large irrigation district. Background Art

[0002] Irrigation district water replenishment pump stations are essentially similar to conventional irrigation district headwater pumping stations. The blade placement angles of these pump stations generally remain unchanged during one operation, and they can be regarded as non-adjustable operating conditions units. When large-scale irrigation district headwaters divert water at different times, due to changes in water source conditions and water rights restrictions, the headwater diversion flow and water volume may be different each time. If the headwater diversion volume cannot meet the needs of the irrigation district, the irrigation district water replenishment pump station will need to extract spare water resources for replenishment. The difference between the operation of large-scale irrigation water replenishment pump stations and traditional irrigation head water lifting pump stations is that once the traditional irrigation head water lifting pump stations are installed, the blade placement angle remains unchanged. When the water diversion volume of the irrigation head changes, the head water pump station can only operate at a fixed blade placement angle. When the water diversion volume within the specified time is determined, the water pumping cost is too high; after the large-scale irrigation water replenishment pump station is completed once, the time interval between operations is relatively long. According to the different head of each water replenishment pump station, the blade placement angle of the water replenishment pump station is adjusted accordingly, which can effectively reduce the operation cost of the pump station; especially the implementation of peak and valley electricity prices is more conducive to further reducing the water replenishment cost of irrigation water replenishment pump stations, but no research has been carried out on this. Summary of the Invention

[0003] Purpose of the invention: The purpose of the present invention is to provide a method for optimizing the operation of irrigation water replenishment pump stations in large irrigation areas, so as to adjust the different blade placement angles of the water replenishment pump stations according to the different water replenishment water volume requirements each time, and seek the minimum startup cost in combination with peak and valley electricity prices.

[0004] Technical solution: A method for optimizing the operation of irrigation water replenishment pump stations in large irrigation areas, comprising the following steps:

[0005] S1, collect the planting types of irrigation areas, planting area of ​​each crop A, average gross irrigation volume per mu m 毛 , time-of-use electricity price ΔP, duration of different time-of-use electricity prices ΔT; determine the total water demand W for one irrigation area 总 ; Collect the amount of water W that can be provided by the irrigation area canal head 渠首 , determine the required water supply volume W 补 ;

[0006] S2: Number each pump in the water supply pump station and discretize the blade placement angle of each pump. Once the blade placement angle is determined, the startup flow rate and efficiency of each pump at different blade placement angles are determined in combination with the water lift.

[0007] S3, based on the water replenishment volume requirements, with the minimum water replenishment cost in one replenishment process as the objective function, and with the total water replenishment volume and pump power as constraints, establish an optimization model for the startup mode of the water replenishment pump station;

[0008] S4, assuming that the placement angles of the blades of each water pump remain unchanged during a startup process, optimize the startup method of the pump station and determine the placement angles of the blades of each water pump during this startup process based on the minimum startup cost under the condition of meeting the water replenishment volume requirements.

[0009] Further, in step S1, the required water supply volume W is determined. 补 The implementation steps are as follows:

[0010] S11, investigate the types of crops planted in the irrigation area. The planting areas of different species are A1, A2, ┄, A i ; The gross irrigation quotas for different crops are m 1毛 、m 2毛 、┄、m i毛 , i is the crop type; then the total irrigation water demand of the irrigation area is W 总 for:

[0011] W 总 =A1m 1毛 +A2m 2毛 +…+A i m i毛

[0012] S12, based on the water volume W provided by the irrigation canal head 渠首 , determine the required water volume W of the water supply pump station 补 :

[0013] W 补 =W 总 -W 渠首

[0014] S13, investigating the time-of-use electricity prices ΔP in different regions and the duration ΔT of different time-of-use electricity prices.

[0015] Furthermore, in step S2, the steps for determining the startup flow rate and efficiency of each water pump at different blade placement angles are as follows:

[0016] S21, number each water pump according to the actual water replenishment pump station, r = 1, 2, ┄, x, r represents the rth water pump, x is the total number of water pumps;

[0017] S22, discretize the blade placement angle of each water pump, and let the j-th blade placement angle of the r-th water pump be θ rj ;

[0018] S23, at the blade placement angle θ rj Under certain conditions, there are:

[0019] H(θ rj )=a1Q rj 2 (θ rj )+b1Q rj (θ rj )+c1

[0020] η(θ rj )=a2Q rj 3 (θ rj )+b2Q rj 2 (θ rj )+c2Q rj (θ rj )+d

[0021] Where Q rj (θ rj ) refers to the rth pump, and the blade placement angle is θ rj The corresponding flow rate;

[0022] H(θ rj ) refers to the rth pump, and the blade placement angle is θ rj The corresponding lift when

[0023] η(θ rj ) is the rth water pump, and the blade placement angle is θ rj The corresponding efficiency;

[0024] a1, b1, c1, a2, b2, c2, d are constants;

[0025] S24, when the lift is determined, according to H(θ rj ),η(θ rj ) Calculate different blade placement angles θ rj The corresponding flow rate Q rj (θ rj ) and efficiency η(θ rj ); each water pump is represented as follows:

[0026] Water pump No. 1: 0, (Q 11 , η 11 ), (Q 12 , η 12 ), ---, (Q 1k , η 1k );

[0027] Water pump No. 2: 0, (Q 21 , η 21 ), (Q 22 , η 22 ), ---, (Q2k , η 2k );

[0028] ---------

[0029] Pump No. x: 0, (Q x1 , η x1 ), (Q x2 , η x2 ), ---, (Q xk , η xk );

[0030] Among them, 0 means that the flow rate of the pump is 0; k represents the discrete number of blade placement angles of each unit.

[0031] Furthermore, in step S3, the objective function is expressed as follows:

[0032]

[0033] The constraints are as follows:

[0034]

[0035] Q rj (ΔT1)=Q rj (ΔT2)=---=Q rj (ΔT s )

[0036] η rj (ΔT1)=η rj (ΔT2)=---=η rj (ΔT s )

[0037] ΔT1+ΔT2+…+ΔT s =ΔT

[0038] Where U represents the water replenishment cost; γ 水 Indicates the specific gravity of water; Q rj represents the flow rate of the rth pump at the jth blade placement angle; η rj represents the pump efficiency of the rth pump at the jth blade placement angle; H r represents the head of the rth pump when it is working; [N0] represents the allowable power of the pump when it is running; s represents the number of time periods divided according to the time-of-use electricity price, ΔT s Indicates the length of the sth period, ΔT indicates the total length of this startup time; ΔP s represents the time-of-use electricity price in period s; Q rj (ΔT s ) represents the sThe flow rate when the rth pump runs at the jth blade placement angle during the time period; η rj (ΔT s ) represents the time at ΔT s The efficiency of the rth water pump when it operates at the jth blade placement angle during the time period.

[0039] Furthermore, in step S4, the steps for solving the pump station startup mode are as follows:

[0040] S41, select the first water pump, number N = 1

[0041] L1=0,0.1W 补 ,0.2W 补 ,…,W 补

[0042] Where N is the pump number; L1 represents the discrete value of water volume; 0.1W 补 , 0.2W 补 ,…,W 补 The water volume in each stage is discrete, and the discrete interval of water volume is 0.1W 补 , W 补 =W 总 -W 渠首 ;

[0043] u1(L1)=γ 水 ·Q1·H·(ΔT1·ΔP1+ΔT2·ΔP2+…+ΔT s ΔP s ) / η1

[0044] Q1ΔT≥L1

[0045] Where, u1(L1) represents the water intake cost of the first water pump; Q1 represents the flow rate of the first water pump;

[0046] S42, select N=m water pumps in order, where m=2 to (x-1);

[0047] L m =0,0.1W 补 ,0.2W 补 ,...,W 补

[0048] u m (L m )=min{ρ 水 ·g·Q m ·H·(ΔT1·ΔP1+ΔT2·ΔP2+…+ΔT s ΔP s ) / η m +u m-1 (L m-1 )}

[0049] And: L m =L m-1 +Q m ΔT

[0050]

[0051] Where u m (L m ) represents the total water extraction cost from the first water pump to the mth water pump; u m-1 (L m-1 ) represents the total water extraction cost from the first water pump to the m-1th water pump; Q r represents the flow rate of the rth water pump, r = 1~m; Q m represents the flow rate of the mth water pump; η m represents the efficiency of the mth water pump; L m Indicates the discrete value of water volume when the mth water pump is selected; L m-1 Indicates the discrete value of water volume when the m-1th water pump is selected;

[0052] S43, select the last water pump, at this time N = x;

[0053] u x (L x )=min{ρ·g·Q x ·H·(ΔT1·ΔP1+ΔT2·ΔP2+…+ΔT s ΔP s ) / η x +u x-1 (L x-1 )}

[0054] L x =W 补 ,1.05W 补 ,1.1W 补 ,1.15W 补 , 1.2W 补

[0055] And: L x =L x-1 +Q x ΔT x

[0056] Obtain U x =u x (L x ), query the corresponding water replenishment volume W 最优 (U x ), and the corresponding optimal startup mode of each water pump (Q1′,η1′), (Q2′,η2′), ---, (Q x ′,ηx ′);

[0057] Where u x (L x ) represents the total water extraction cost from the first water pump to the xth water pump, u x-1 (L x-1 ) represents the total water extraction cost from the first water pump to the x-1th water pump; L x Indicates the discrete value of water volume when the x-th water pump is selected, L x-1 represents the discrete value of water volume when the x-1th water pump is selected; Q x represents the flow rate of the x-th water pump; η x Indicates the efficiency of the x-th water pump; U x W is the minimum water extraction cost from the first water pump to the xth water pump; 最优 (U x ) corresponds to U x The total water intake of the water supply pump station; (Q1′,η1′), (Q2′,η2′), ---, (Q x ′,η x ′) refers to the x The optimal startup mode for each water pump in each time period;

[0058] S44, W 最优 (U x ) and the required water replenishment volume W 补 For comparison, the comparison value g is calculated as follows:

[0059]

[0060] If g<5%, the optimization result meets the requirements;

[0061] If g≥5%, further reduce the discrete interval of water volume and repeat steps S41 to S43 until the optimization result meets the requirements.

[0062] Compared with the prior art, the present invention has the following significant effects:

[0063] The present invention adjusts the different blade placement angles of the water replenishment pump station according to the different water replenishment water volume requirements for each irrigation in large irrigation areas, combined with peak and valley electricity prices, which can effectively reduce the water lifting costs of the water replenishment pump station, and provide the possibility for optimized operation of the water replenishment pump station with different water replenishment water volume requirements in different periods, and can provide a reference for daily operation and management of irrigation areas. BRIEF DESCRIPTION OF THE DRAWINGS

[0064] Figure 1 Flowchart of the present invention. DETAILED DESCRIPTION

[0065] The present invention will be described in further detail below with reference to the accompanying drawings and specific implementations.

[0066] like Figure 1 FIG. 1 is a flow chart of a method for optimizing operation of a large irrigation area irrigation water replenishment pump station according to the present invention, comprising the following steps:

[0067] Step 1: Collect the planting types, planting area of ​​each crop A, and average gross irrigation volume m per mu in the irrigation area. 毛 , time-of-use electricity price ΔP, duration of different time-of-use electricity prices ΔT; determine the total water demand W for one irrigation area 总 ; Collect the amount of water W that can be provided by the irrigation area canal head 渠首 , determine the required water supply volume W 补 ; The steps include:

[0068] Step 11: Investigate the types of crops planted in the irrigation area. The planting areas of different species are A1, A2, ┄, A i ; The gross irrigation quotas for different crops are m 1毛 、m 2毛 、┄、m i毛 , i is the crop type; the total irrigation water demand of the irrigation area is:

[0069] W 总 =A1m 1毛 +A2m 2毛 +…+A i m i毛 (1)

[0070] Step 12: Based on the water volume W provided by the irrigation area canal head 渠首 , determine the required water volume W of the water supply pump station 补 :

[0071] W 补 = W 总 -W 渠首 (2)

[0072] Step 13: Investigate the time-of-use electricity prices ΔP in different regions and the duration ΔT of different time-of-use electricity prices.

[0073] Step 2: Number each water pump in the water supply pump station and discretize the blade placement angle of each water pump. When the blade placement angle is determined, combined with the water lifting head, determine the startup flow rate and efficiency of each water pump at different blade placement angles.

[0074] Step 21: number each water pump according to the actual water replenishment pump station, r = 1, 2, ┄, x, r represents the rth water pump, and x is the total number of water pumps.

[0075] Step 22: Discretize the blade placement angle of each pump and set it as θrj ,θ rj That is the j-th blade placement angle of the r-th water pump.

[0076] Step 23, at the blade placement angle θ rj Under certain conditions, there are:

[0077] H(θ rj )=a1Q rj 2 (θ rj )+b1Q rj (θ rj )+c1 (3)

[0078] η(θ rj )=a2Q rj 3 (θ rj )+b2Q rj 2 (θ rj )+c2Q rj (θ rj )+d (4)

[0079] Where Q rj (θ rj ) refers to the rth pump, and the blade placement angle is θ rj The corresponding flow rate;

[0080] H(θ rj ) refers to the rth pump, and the blade placement angle is θ rj The corresponding lift when

[0081] η(θ rj ) is the rth water pump, and the blade placement angle is θ rj The corresponding efficiency;

[0082] a1, b1, c1, a2, b2, c2, and d are constants.

[0083] Step 24: When the lift is determined, the blade placement angles θ can be calculated according to equations (3) and (4). rj The corresponding flow rate Q rj (θ rj ) and efficiency η(θ rj ); Each water pump is represented as follows:

[0084] Water pump No. 1: 0, (Q 11 , η 11 ), (Q 12 , η 12 ), ---, (Q 1k , η 1k );

[0085] Water pump No. 2: 0, (Q 21 , η 21 ), (Q 22 , η 22 ), ---, (Q 2k , η 2k );

[0086] ---------

[0087] Pump No. x: 0, (Q x1 , η x1 ), (Q x2 , η x2 ), ---, (Q xk , η xk );

[0088] Among them, "0" means that the water pump flow is 0, that is, the water pump is not turned on; k represents the discrete number of blade placement angles of each unit.

[0089] Step 3: Based on the replenishment water volume requirement, with the minimum replenishment cost in one replenishment process as the objective function, and with the total replenishment volume and pump power as constraints, establish a replenishment pump station startup optimization model;

[0090] The objective function is as follows:

[0091]

[0092] The constraints are as follows:

[0093]

[0094] Q rj (ΔT1)=Q rj (ΔT2)=---=Q rj (ΔT s ) (8)

[0095] η rj (ΔT1)=η rj (ΔT2)=---=η rj (ΔT s ) (9)

[0096] ΔT1+ΔT2+…+ΔT s =ΔT (10)

[0097] Where U represents the water replenishment cost; γ 水 Indicates the specific gravity of water; Q rj represents the flow rate of the rth pump at the jth blade placement angle; η rj represents the pump efficiency of the rth pump at the jth blade placement angle; H rrepresents the head of the rth pump when it is working; [N0] represents the allowable power of the pump when it is running; s represents the number of time periods divided according to the time-of-use electricity price, ΔT s Indicates the length of the sth period, ΔT indicates the total length of this startup time; ΔP s represents the time-of-use electricity price in period s; Q rj (ΔT s ) represents the s The flow rate when the rth pump runs at the jth blade placement angle during the time period; η rj (ΔT s ) represents the time at ΔT s The efficiency of the rth water pump when it operates at the jth blade placement angle during the time period.

[0098] Step 4: Assuming that the blade placement angles of each water pump remain unchanged during a startup process, optimize the startup method of the pump station and determine the blade placement angles of each water pump during this startup process based on the minimum startup cost under the condition of meeting the water replenishment volume requirements.

[0099] The head H of the water supply pump station during operation is known. Combined with the operating characteristics of large water supply pump stations, the pump station startup mode can be solved using the following method:

[0100] Step 41, select the first water pump, number N = 1

[0101] L1=0,0.1W 补 ,0.2W 补 ,...,W 补 (11)

[0102] Where L1 represents the discrete value of water volume; 0.1W 补 , 0.2W 补 The water volume in each discrete stage is equal to 0.1W. 补 , W 补 =W 总 -W 渠首 .

[0103] u1(L1)=γ 水 ·Q1·H·(ΔT1·ΔP1+ΔT2·ΔP2+…+ΔT s ΔP s ) / η1 (12)

[0104] Q1ΔT≥L1 (13)

[0105] Where u1(L1) represents the water intake cost of the first water pump; Q1 represents the flow rate of the first water pump, and N is the water pump number.

[0106] Step 42, select N=m water pumps in order, where m=2 to (x-1);

[0107] L m =0,0.1W 补 ,0.2W 补 ,...,W 补 (14)

[0108] and:

[0109] u m (L m )=min{γ 水 Q m ·H·(ΔT1·ΔP1+ΔT2·ΔP2+…+ΔT s ΔP s ) / η m +u m-1 (L m-1 )} (16)

[0110] And: L m =L m-1 +Q m ·ΔT. (17)

[0111] Where u m (L m ) represents the total water extraction cost from the first water pump to the mth water pump; u m-1 (L m-1 ) represents the total water extraction cost from the first water pump to the m-1th water pump; Q r represents the flow rate of the rth water pump, r = 1~m; Q m represents the flow rate of the mth water pump; η m represents the efficiency of the mth water pump; L m Indicates the discrete value of water volume when the mth water pump is selected; L m-1 Indicates the discrete value of water volume when the m-1th water pump is selected.

[0112] Step 43, select the last water pump, that is, N = x

[0113] u x (L x )=min{γ 水 Q x ·H·(ΔT1·ΔP1+ΔT2·ΔP2+…+ΔT s ΔP s ) / η x +u x-1 (L x-1 )} (18)

[0114] L x =W 补 ,1.05W补 ,1.1W 补 ,1.15W 补 , 1.2W 补 (19)

[0115] And: L x =L x-1 +Q x ΔT x (20)

[0116] Then: U x =u x (L x )(twenty one)

[0117] Obtain U x =u x (L x ), query the corresponding water replenishment volume W 最优 (U x ), and the corresponding optimal startup mode of each water pump (Q1′,η1′), (Q2′,η2′), ---, (Q x ′,η x ′).

[0118] Where u x (L x ) represents the total water extraction cost from the first water pump to the xth water pump, u x-1 (L x-1 ) represents the total water extraction cost from the first water pump to the x-1th water pump; L x Indicates the discrete value of water volume when the x-th water pump is selected, L x-1 represents the discrete value of water volume when the x-1th water pump is selected; Q x represents the flow rate of the x-th water pump; η x Indicates the efficiency of the x-th water pump; U x W is the minimum water extraction cost from the first water pump to the xth water pump; 最优 (U x ) corresponds to U x The total water intake of the water supply pump station; (Q1′,η1′), (Q2′,η2′), ---, (Q x ′,η x ′) refers to the x The optimal startup method for each water pump in each time period.

[0119] Step 44, according to the obtained W 最优 (U x ), and the required water replenishment volume W 补 For comparison, the comparison value g is calculated as follows:

[0120]

[0121] If g<5%, the optimization result meets the requirements;

[0122] If g≥5%, the water volume discrete interval can be further reduced by using equations (11) and (14), and the water volume discrete interval can be reduced from 0.1W 补 becomes 0.05W 补 , repeat steps 41 to 43 until the optimization result meets the requirements.

[0123] In this example, a large gravity irrigation area along the Grand Canal in Jiangsu Province was selected. This area practices rice-wheat rotation. In normal years, water is diverted by gravity from the Grand Canal. One of the main canals controls an area of ​​25,000 mu. In a year of exceptional drought (P = 95%), the rice planting area is 20,000 mu and the spring corn planting area is 5,000 mu. The implementation steps are as follows:

[0124] Step 1: The average irrigation volume per mu of rice in May 2023 is 50m 3 / mu, the average gross irrigation volume per mu for spring corn is 25m 3 / mu.

[0125] Step D1, calculate the total water demand of the irrigation area:

[0126] W 总 =A1m 1毛 +A2m 2毛

[0127] =2.0×50+0.5×25=1.125 million m 3

[0128] Step D2: Since the head of the canal is located in the Grand Canal, the flow is restricted by water rights and the head of the canal can only provide 975,000 m 3 The amount of water that needs to be replenished through the water replenishment pump station:

[0129] W 补 =W 总 -W 渠首

[0130] =112.5-97.5=150,000 m 3

[0131] That is, 150,000 m3 of water is needed to implement this irrigation. 3 The amount of water.

[0132] Step D3: Divide the whole day into three periods according to Jiangsu's time-of-use electricity price:

[0133] Period 1, 7:00-19:00, total duration ΔT1 = 12h, time-of-use electricity price ΔP1 = 1.07 yuan / kW;

[0134] Period 2, 19:00-24:00, total duration ΔT2 = 5h, time-of-use electricity price ΔP2 = 0.64 yuan / kW;

[0135] Time period 3, 0:00~7:00, total duration ΔT3=7h, time-of-use electricity price ΔP3=0.29 yuan / kW.

[0136] Step 2: Number each pump in the water supply pump station and discretize the blade placement angle of each pump. Once the blade placement angle is determined, the startup flow rate and efficiency of each pump at different blade placement angles are determined in combination with the water lift. The implementation steps are as follows:

[0137] Step F1: Two water replenishment pumping stations are built on the main canal. The basic information of the pumping stations is as follows:

[0138] The first pumping station is Xincheng Station, which has two sets of 20ZLB-100 water pumps (D=450mm, n=730r / min), named No. 1 water pump and No. 2 water pump respectively. The two water pumps have the same performance.

[0139] The second pumping station is Longben Station, which has two sets of 700ZLB-160 water pumps (D=630mm, n=730r / min), named No. 3 water pump and No. 4 water pump respectively. The two water pumps have the same performance.

[0140] Step F2: discretize the blade angles of water pumps No. 1, No. 2, No. 3, and No. 4.

[0141] For pump No. 1, the blade angles are discretely set to -2°, 0°, and +2° according to local usage habits;

[0142] For pump No. 2, the blade angles are discretely set to -2°, 0°, and +2° according to local usage habits;

[0143] For pump No. 3, the blade angles are discretely set to -2°, 0°, and +2° according to local usage habits;

[0144] For pump No. 4, the blade angles are discretely set to -2°, 0°, and +2° according to local usage habits;

[0145] Step F3, check the water pump performance curve;

[0146] The performance curves of pumps No. 1 and No. 2 when the blade angles are +2°, 0°, and -2° are as follows:

[0147] H(1, +2°) = 32.56Q 2 -56.12Q+24.495

[0148] η(1, +2°) = -123.41Q 3 +216.03Q2 -125.99Q+25.275

[0149] H(1,0°)=50.879Q 2 -73.97Q+27.936

[0150] η(1, 0°)=-129.17Q 3 +211.12Q 2 -114.91Q+21.619

[0151] H(1, -2°)=71.688Q 2 -92.306Q+30.852

[0152] η(1, -2°)=28.571Q 3 -53.429Q 2 +31.886Q-5.365

[0153] The performance curves of No. 3 and No. 4 water pumps at blade angles of +2°, 0°, and -2° are as follows:

[0154] H(3, +2°) = 1.9802Q 2 -10.631Q+12.153

[0155] η(3, +2°) = -3.9099Q 3 +12.237Q 2 -12.558Q+5.0346

[0156] H(3,0°)=19.015Q 2 -48.249Q+32.053

[0157] η(3, 0°)=20.938Q 3 -69.975Q 2 +77.497Q-27.63

[0158] H(3, -2°)=5.0372Q 2 -17.676Q+14.9

[0159] η(3, -2°)=5.4701Q 3 -21.024Q 2 +25.543Q-9.1391

[0160] In the above formula: H is the head, η is the efficiency; Q represents the flow rate.

[0161] H(1, +2°) represents the head when the blade angle of the first pump is +2°;

[0162] η(1, +2°) represents the efficiency of the first pump when the blade angle is +2°;

[0163] In the brackets, "1" indicates the first water pump; "+2°" indicates that the blade angle of the water pump is +2°.

[0164] The performance curve of water pump No. 2 is exactly the same as that of water pump No. 1;

[0165] The performance curve of water pump No. 4 is exactly the same as that of water pump No. 3.

[0166] Step 3: Based on the above water replenishment volume requirements, with the minimum water replenishment cost in one replenishment process as the objective function, and with the total water replenishment volume and pump power as constraints, an optimization model for the startup mode of the water replenishment pump station is established; the implementation steps are as follows:

[0167] Step G1, establish the objective function as follows:

[0168]

[0169] Constraints:

[0170]

[0171] Q rj (ΔT1)=Q rj (ΔT2)=Q rj (ΔT3), η rj (ΔT1)=η rj (ΔT2) = η rj (ΔT3), that is, during one operation, the blade placement angle remains unchanged, and the corresponding flow rate and efficiency remain unchanged.

[0172] ΔT1+ΔT2+ΔT3=24

[0173] Where Q rj represents the flow rate of the rth pump at the jth blade angle; η rj represents the pump efficiency of pump No. r at blade angle No. j; H represents the pump head during this water replenishment, which is 2.0m; [N0] represents the allowable power during pump operation, which is 20kW for pumps No. 1 and 2, and 50kW for pumps No. 3 and 4; ΔT = 24 (hours).

[0174] Step G2, when the lift H = 2.0m, the flow rate and efficiency of pumps No. 1, No. 2, No. 3, and No. 4 at the corresponding blade angles are as follows:

[0175] Water pump No. 1: (0.63, 0.78), (0.59, 0.79), (0.53, 0.785);

[0176] Water pump No. 2: (0.63, 0.78), (0.59, 0.79), (0.53, 0.785);

[0177] Water pump No. 3: (1.77, 0.79), (1.58, 0.80), (1.4, 0.78);

[0178] Water pump No. 4: (1.77, 0.79), (1.58, 0.80), (1.4, 0.78).

[0179] The first, second, and third sets of values ​​for each water pump in the above formula correspond to the flow rate Q and efficiency η corresponding to the blade placement angles of +2°, 0°, and -2°, respectively.

[0180] Step 4: Set the blade placement angle of each pump to remain unchanged during the startup process, optimize the startup method of each pump, and determine the minimum startup cost under the condition of meeting the water replenishment volume requirements. Based on this, the blade placement angle of each pump during this startup process is determined. The solution process is as follows:

[0181] Step K1, select water pump No. 1, number N=1:

[0182] L1=0,1,2,3,...,14,15

[0183] u1(L1)=γ 水 ·Q1·H·(ΔT1·ΔP1+ΔT2·ΔP2+ΔT3·ΔP3) / η1

[0184] Q1ΔT≥L1

[0185] Where, Q1 and η1 are the flow rate and efficiency of water pump No. 1 respectively.

[0186] Step K2, select the water pump numbered m (m=2-3) in order,

[0187] L m =0,1,2,3,...,14,15

[0188] u m (L m )=min{γ 水 Q m ·H m ·(ΔT1·ΔP1+ΔT2·ΔP2+ΔT3·ΔP3) / η m +u m-1 (L m-1 )}

[0189] And: L m =L m-1 +Q m ΔT

[0190] Where m = 2, Q2, η2 are the flow rate and efficiency of pump No. 2 respectively;

[0191] m=3, Q3, η3 are the flow rate and efficiency of water pump No. 3 respectively.

[0192] Step K3, select the 4th water pump,

[0193] u4(L4)=min{γ 水 ·Q4·H·(ΔT1·ΔP1+ΔT2·ΔP2+ΔT3·ΔP) / η4+u3(L3)}

[0194] L4=15,15.75,16.5,17.25,18.

[0195] Where Q4 and η4 represent the values ​​of water pump No. 4 respectively.

[0196] And: L4=L3+Q4·ΔT

[0197] Then: U=u4(L4)

[0198] According to the above calculation process, the optimization results are shown in Table 1.

[0199] Table 1 Head 2.0m, water supply volume 150,000m 3 Optimization results of water pump startup mode and blade placement angle

[0200]

[0201] The difference between the water replenishment volume obtained from the optimization result and the required water replenishment volume is:

[0202]

[0203] The optimization results meet the requirements. The startup methods of each water pump in Table 1 are the startup methods that meet the minimum water replenishment cost.

Claims

1. A method for optimizing the operation of a large irrigation area irrigation water supply pump station, characterized in that: The steps are as follows: S1, collect the planting types of irrigation areas, planting area of ​​each crop A, average gross irrigation volume per mu m 毛 , time-of-use electricity price ΔP, duration of different time-of-use electricity prices ΔT; determine the total water demand W for one irrigation area 总 ; The amount of water W that can be provided by the canal head in the collection irrigation area 渠首 , determine the required water supply volume W 补 ; S2: Number each pump in the water supply pump station and discretize the blade placement angle of each pump. Once the blade placement angle is determined, the startup flow rate and efficiency of each pump at different blade placement angles are determined in combination with the water lift. S3, based on the water replenishment volume requirements, with the minimum water replenishment cost in one replenishment process as the objective function, and with the total water replenishment volume and pump power as constraints, establish an optimization model for the startup mode of the water replenishment pump station; S4, assuming that the placement angles of the blades of each water pump remain unchanged during a startup process, optimize the startup method of the pump station and determine the placement angles of the blades of each water pump during this startup process based on the minimum startup cost under the condition of meeting the water replenishment volume requirements.

2. The method for optimizing operation of a large irrigation area irrigation water supply pump station according to claim 1, characterized in that: In step S1, the required water supply volume W is determined 补 The implementation steps are as follows: S11, investigate the types of crops planted in the irrigation area. The planting areas of different species are A1, A2, ┄, A i ; The gross irrigation quotas for different crops are m 1毛 、m 2毛 、┄、m i毛 , i is the crop type; then the total irrigation water demand of the irrigation area is W 总 for: W 总 =A1m 1毛 +A2m 2毛 +…+A i m i毛 S12, based on the water volume W provided by the irrigation canal head 渠首 , determine the required water volume W of the water supply pump station 补 : IN 补 =In 总 -IN 渠首 S13, investigating the time-of-use electricity prices ΔP in different regions and the duration ΔT of different time-of-use electricity prices.

3. The method for optimizing operation of a large irrigation area irrigation water supply pump station according to claim 1, characterized in that: In step S2, the steps for determining the startup flow rate and efficiency of each water pump at different blade placement angles are as follows: S21, number each pump according to the actual water replenishment pump station, r = 1, 2, ┄, x, r represents the rth pump, x is the total number of pumps; S22, discretize the blade placement angle of each water pump, and let the j-th blade placement angle of the r-th water pump be θ rj ; S23, at the blade placement angle θ rj Under certain conditions, there are: H(θ rj )=a1Q rj 2 (i rj )+b1Q rj (i rj )+c1 n(θ rj )=a2Q rj 3 (i rj )+b2Q rj 2 (i rj )+c2Q rj (i rj )+d Where Q rj (θ rj ) refers to the rth pump, and the blade placement angle is θ rj The corresponding flow rate; H(θ rj ) refers to the rth pump, and the blade placement angle is θ rj The corresponding lift when η(θ rj ) is the rth water pump, and the blade placement angle is θ rj The corresponding efficiency; a1, b1, c1, a2, b2, c2, d are constants; S24, when the lift is determined, according to H(θ rj ),η(θ rj ) Calculate different blade placement angles θ rj The corresponding flow rate Q rj (θ rj ) and efficiency η(θ rj ); each water pump is represented as follows: Water pump No. 1: 0, (Q 11 , η 11 ), (Q 12 , η 12 ), ---, (Q 1k , η 1k ); Water pump No. 2: 0, (Q 21 , η 21 ), (Q 22 , η 22 ), ---, (Q 2k , η 2k ); --------- Pump No. x: 0, (Q x1 , η x1 ), (Q x2 , η x2 ), ---, (Q xk , η xk ); Among them, 0 means that the flow rate of the pump is 0; k represents the discrete number of blade placement angles of each unit.

4. The method for optimizing operation of a large irrigation area irrigation water supply pump station according to claim 3, characterized in that: In step S3, the objective function is expressed as follows: The constraints are as follows: Q rj (ΔT1)=Q rj (ΔT2)=---=Q rj (ΔT s ) or rj (ΔT1)=η rj (ΔT2)=---=η rj (ΔT s ) ΔT1+ΔT2+…+ΔT s =ΔT Where U represents the water replenishment cost; γ 水 Indicates the specific gravity of water; Q rj represents the flow rate of the rth pump at the jth blade placement angle; η rj represents the pump efficiency of the rth pump at the jth blade placement angle; H r represents the head of the rth pump when it is working; [N0] represents the allowable power of the pump when it is running; s represents the number of time periods divided according to the time-of-use electricity price, ΔT s Indicates the length of the sth period, ΔT indicates the total length of this startup time; ΔP s represents the time-of-use electricity price in period s; Q rj (ΔT s ) represents the s The flow rate when the rth pump runs at the jth blade placement angle during the time period; η rj (ΔT s ) represents the time difference between ΔT and s The efficiency of the rth water pump when it operates at the jth blade placement angle during the time period.

5. The method for optimizing operation of a large irrigation area irrigation water supply pump station according to claim 4, characterized in that: In step S4, the steps for solving the pump station startup mode are as follows: S41, select the first water pump, number N = 1 <h2 style=";text-align:left;direction:ltr">L1 = 0,0.1W<h2 style=";text-align:left;direction:ltr"> 补 <h2 style=";text-align:left;direction:ltr"> 0.2W<h2 style=";text-align:left;direction:ltr"> 补 <h2 style=";text-align:left;direction:ltr"> ,…,W<h2 style=";text-align:left;direction:ltr"> 补 Where N is the pump number; L1 represents the discrete value of water volume; 0.1W 补 , 0.2W 补 ,…,W 补 The water volume in each stage is discrete, and the discrete interval of water volume is 0.1W 补 , W 补 =W 总 -W 渠首 ; u1(L1)=γ 水 ·Q1·H·(ΔT1·ΔP1+ΔT2·ΔP2+…+ΔT s ·ΔP s ) / η1 Q1ΔT≥L1 Where, u1(L1) represents the water intake cost of the first water pump; Q1 represents the flow rate of the first water pump; S42, select N=m water pumps in order, where m=2 to (x-1); <h2 style=";text-align:left;direction:ltr">L<h2 style=";text-align:left;direction:ltr"> m <h2 style=";text-align:left;direction:ltr"> <0.0.1W<h2 style=";text-align:left;direction:ltr"> 补 <h2 style=";text-align:left;direction:ltr"> 0.2W<h2 style=";text-align:left;direction:ltr"> 补 <h2 style=";text-align:left;direction:ltr"> ,...,W<h2 style=";text-align:left;direction:ltr"> 补 you m (L m )=min{ρ 水 ·g·Q m ·H·(ΔT1·ΔP1+ΔT2·ΔP2+…+ΔT s ·ΔP s ) / or m +u m-1 (L m-1 )} And: L m =L m-1 +Q m ΔT Where u m (L m ) represents the total water extraction cost from the first water pump to the mth water pump; u m-1 (L m-1 ) represents the total water extraction cost from the first water pump to the m-1th water pump; Q r represents the flow rate of the rth water pump, r = 1~m; Q m represents the flow rate of the mth water pump; η m represents the efficiency of the mth water pump; L m Indicates the discrete value of water volume when the mth water pump is selected; L m-1 Indicates the discrete value of water volume when the m-1th water pump is selected; S43, select the last water pump, at this time N = x; you x (L x )=min{ρ·g·Q x ·H·(ΔT1·ΔP1+ΔT2·ΔP2+…+ΔT s ·ΔP s ) / or x +u x-1 (L x-1 )} L x =W 补 ,1.05W 补 ,1.1W 补 ,1.15W 补 ,1.2W 补 And: L x =L x-1 +Q x ΔT x Obtain U x =u x (L x ), query the corresponding water replenishment volume W 最优 (U x ), and the corresponding optimal startup mode of each water pump (Q1′,η1′), (Q2′,η2′), ---, (Q x ′,η x ′); Where u x (L x ) represents the total water extraction cost from the first water pump to the xth water pump, u x-1 (L x-1 ) represents the total water extraction cost from the first water pump to the x-1th water pump; L x Indicates the discrete value of water volume when the x-th water pump is selected, L x-1 represents the discrete value of water volume when the x-1th water pump is selected; Q x represents the flow rate of the x-th water pump; η x Indicates the efficiency of the x-th water pump; U x W is the minimum water extraction cost from the first water pump to the xth water pump; 最优 (U x ) corresponds to U x The total water intake of the water supply pump station; (Q1′,η1′), (Q2′,η2′), ---, (Q x ′,η x ′) refers to the x The optimal startup mode for each water pump in each time period; S44, W 最优 (U x ) and the required water replenishment volume W 补 For comparison, the comparison value g is calculated as follows: If g<5%, the optimization result meets the requirements; If g≥5%, further reduce the discrete interval of water volume and repeat steps S41 to S43 until the optimization result meets the requirements.

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