Calculation method of economic tunnel diameter of diversion tunnel of diversion type hydropower station

Abstract

The application discloses a calculation method of an economic tunnel diameter of a diversion tunnel of a diversion type hydropower station, simplifies the calculation method of the economic tunnel diameter of the diversion tunnel of the diversion type hydropower station, and enables engineering designers to not need repeated trial calculation, greatly reduces design calculation workload, simplifies a design procedure, and is more accurate compared with blind trial calculation results of the engineering designers by using mathematical model calculation results, and is favorable for engineering design and investment decision of the diversion type hydropower station.

Description

Technical Field

[0001] This invention relates to the field of design of diversion-type hydropower stations, and in particular to a method for calculating the economic diameter of the diversion tunnel in a diversion-type hydropower station. Background Technology

[0002] In the design of diversion-type hydropower stations, the investment in the diversion tunnel typically accounts for a large proportion of the total project investment and has a significant impact on investment decisions. Both the investment in the diversion tunnel and the power generation revenue of the hydropower station are closely related to the diameter of the diversion tunnel. Increasing the tunnel diameter leads to increased investment, but correspondingly reduces head loss and increases power generation revenue; conversely, decreasing the tunnel diameter reduces investment, but correspondingly increases head loss and decreases power generation revenue. Therefore, rationally selecting the diameter of the diversion tunnel is crucial to maximizing investment returns.

[0003] In engineering design, to obtain a relatively economically optimal water diversion tunnel diameter, the current common method is to select the economical flow velocity of the water diversion tunnel based on engineering experience and calculate the corresponding tunnel diameter. Then, based on this diameter, the tunnel diameter is appropriately increased or decreased, and the investment and power generation revenue of the water diversion tunnel are calculated separately for different diameters. Finally, an economic evaluation analysis is conducted, and the tunnel diameter with the best economic indicators among different diameters is selected as the economical tunnel diameter. The current method requires engineering design, quantity calculation, power generation revenue calculation, and economic evaluation analysis for different tunnel diameters, resulting in a large workload and complex content.

[0004] Therefore, if a simple and practical method for calculating the economic diameter of the diversion tunnel in a diversion-type hydropower station can be provided, it will have significant positive implications for the engineering design and investment decisions of diversion-type hydropower stations. Summary of the Invention

[0005] The purpose of this invention is to provide a method for calculating the economical diameter of the water diversion tunnel in a water diversion hydropower station.

[0006] To achieve the above objectives, the present invention adopts the following technical solution:

[0007] The present invention provides a method for calculating the economical diameter of a water diversion tunnel in a water diversion hydropower station, comprising the following steps:

[0008] S1, the calculation period for the economic diameter of the water diversion tunnel is selected;

[0009] S2, the river runoff series selected for the economic diameter calculation of the water diversion tunnel;

[0010] S3, the initial diameter selected for calculating the economic diameter of the water diversion tunnel. D 0;

[0011] S4, based on steps S1 and S2, calculate the initial tunnel diameter as follows: D 0. When the head loss of the water diversion tunnel is zero, the electricity sales revenue of the diversion-type hydropower station... A 0;

[0012] S5, based on steps S1 and S2, calculate the initial tunnel diameter as follows: D 0. When the head loss in the water diversion tunnel is not zero, the electricity sales revenue of the diversion-type hydropower station... B 0;

[0013] S6, calculate the initial tunnel diameter as D At 0:00, the sum of the rock excavation cost and the steel reinforcement cost for the secondary lining of the water diversion tunnel. E 0;

[0014] S7, calculate the initial tunnel diameter as D At 0:00, the sum of all costs for the water diversion tunnel, excluding the cost of rock excavation and the cost of steel reinforcement for secondary lining. F 0;

[0015] S8, Calculate the economic loss value of the diversion-type hydropower station according to the formula. Y The minimum value corresponds to the tunnel diameter D This refers to the economic loophole.

[0016] Furthermore, the calculation period in step S1 includes the construction period and the operation period.

[0017] Furthermore, the river runoff series in step S2 is selected from historically measured river runoff series.

[0018] Furthermore, the initial tunnel diameter in step S3 D The method for selecting 0 is as follows:

[0019] S3.1, Calculate the tunnel diameter corresponding to the economic flow velocity. ;

[0020] S3.2, Select the adjusted value that conforms to the engineering module. Initial tunnel diameter D 0;

[0021] The tunnel The calculation formula is:

[0022] , The rated flow rate for water diversion for hydropower generation; The economic flow velocity for the water diversion tunnel is 3~5 m / s.

[0023] Furthermore, in step S4, the revenue from electricity sales at diversion-type hydroelectric power stations... A The formula for calculating 0 is:

[0024] ,in, n This represents the total number of time periods corresponding to the flow processes in the river runoff series. i For the first period of calculation i Each time period; For the first i The efficiency of the hydro-generator during a given time period; The specific weight of the water body; For the first i The total head of the power generation water diversion system during each time period; For the first i The sum of head losses in the power generation water diversion system excluding the water diversion tunnel during each time period; For the first i The water diversion flow for power generation during each time period; For the first i The length of each time period; For the first i Electricity prices for specific time periods; For the first i The discount factor for funds over a given period.

[0025] Furthermore, in step S5, the revenue from electricity sales at diversion-type hydroelectric power stations... B The formula for calculating 0 is:

[0026] , For the first i The head loss of the water diversion tunnel during a certain period.

[0027] Furthermore, in step S6, E The formula for calculating 0 is: , This refers to the amount of rock excavation work for the water diversion tunnel; The comprehensive unit price for rock excavation for water diversion tunnels; The amount of steel reinforcement for the secondary lining of the water diversion tunnel; The comprehensive unit price of steel reinforcement for the secondary lining of the water diversion tunnel.

[0028] Furthermore, F The formula for calculating 0 is: , m This represents the total number of other expense items; j For the first j item; For the first j The quantity of work for each item; j For the first j The comprehensive unit price of the item.

[0029] Furthermore, the formula described in step S8 is: The tunnel diameter corresponding to the minimum economic benefit loss value Y. D This refers to the economic loophole.

[0030] The advantages of this invention are that it simplifies the calculation method of the economic diameter of the water diversion tunnel in a water diversion hydropower station, so that engineering designers do not need to repeatedly perform trial calculations, which greatly reduces the workload of design calculations and simplifies the design process. At the same time, the calculation results using mathematical models are more accurate than the results of blind trial calculations by designers, which is beneficial to the engineering design and investment decision-making of water diversion hydropower stations. Attached Figure Description

[0031] Figure 1 This is a flowchart of the method described in this invention.

[0032] Figure 2 This is a graph showing the relationship between different tunnel diameters and economic loss values ​​in Embodiment 2 of the method described in this invention. Detailed Implementation

[0033] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0034] Example 1: Detailed Explanation of the Calculation Method for the Economic Diameter of the Diversion Tunnel in a Diversion-Type Hydropower Station According to the Present Invention

[0035] like Figure 1 As shown, the method for calculating the economic diameter of a water diversion tunnel in a water diversion hydropower station according to the present invention includes the following steps:

[0036] S1 is the calculation period for the economic diameter of the water diversion tunnel; the calculation period includes the construction period and the operation period.

[0037] S2, select the river runoff series calculated from the economic diameter of the water diversion tunnel; the river runoff series is selected from the historical measured river runoff series.

[0038] S3, the initial diameter selected for calculating the economic diameter of the water diversion tunnel. D 0; Initial tunnel diameter D The method for selecting 0 is as follows:

[0039] S3.1, Calculate the tunnel diameter corresponding to the economic flow velocity. ; tunnel The calculation formula is:

[0040] , The rated flow rate for water diversion for hydropower generation; The economic flow velocity for the water diversion tunnel is 3~5 m / s.

[0041] S3.2, Select the adjusted value that conforms to the engineering module. Initial tunnel diameter D 0;

[0042] S4, based on steps S1 and S2, calculate the initial tunnel diameter as follows: D 0. When the head loss of the water diversion tunnel is zero, the electricity sales revenue of the diversion-type hydropower station... A 0; A The formula for calculating 0 is:

[0043]

[0044] in, n This represents the total number of time periods corresponding to the flow processes in the river runoff series. i For the first period of calculation i Each time period; For the first i The efficiency of the hydro-generator during a given time period; The specific weight of the water body; For the first i The total head of the power generation water diversion system during each time period; For the first i The sum of head losses in the power generation water diversion system excluding the water diversion tunnel during each time period; For the first i The water diversion flow for power generation during each time period; For the first i The length of each time period; For the first i Electricity prices for specific time periods; For the first i The discount factor for funds over a given period.

[0045] S5, based on steps S1 and S2, calculate the initial tunnel diameter as follows: D 0. When the head loss in the water diversion tunnel is not zero, the electricity sales revenue of the diversion-type hydropower station... B 0; B The formula for calculating 0 is:

[0046]

[0047] For the first i The head loss of the water diversion tunnel during a certain period.

[0048] S6, calculate the initial tunnel diameter as D At 0:00, the sum of the rock excavation cost and the steel reinforcement cost for the secondary lining of the water diversion tunnel. E 0; E The formula for calculating 0 is:

[0049]

[0050] This refers to the amount of rock excavation work for the water diversion tunnel; The comprehensive unit price for rock excavation for water diversion tunnels; The amount of steel reinforcement for the secondary lining of the water diversion tunnel; The comprehensive unit price of steel reinforcement for the secondary lining of the water diversion tunnel.

[0051] S7, calculate the initial tunnel diameter as D At 0:00, the sum of all costs for the water diversion tunnel, excluding the cost of rock excavation and the cost of steel reinforcement for secondary lining. F 0; F The formula for calculating 0 is:

[0052]

[0053] m This represents the total number of other expense items; j For the first j item; For the first j The quantity of work for each item; j For the first j The comprehensive unit price of the item.

[0054] S8, Calculate the economic loss value of the diversion-type hydropower station according to the formula. Y The minimum value corresponds to the tunnel diameter D This is the economic tunnel. The formula is:

[0055]

[0056] The tunnel diameter corresponding to the minimum economic benefit loss value Y D This refers to the economic loophole.

[0057] The calculation method for the economic diameter of the water diversion tunnel of the water diversion hydropower station described in this invention is based on the following principles:

[0058] The economic diameter of a water diversion tunnel refers to the tunnel diameter that maximizes the revenue of a water-diversion hydropower station within the calculation period. For a water-diversion hydropower station, with the tunnel diameter as the independent variable and maximizing the station's revenue within the calculation period as the objective, analysis of the relationship between electricity sales revenue, water diversion tunnel construction investment, and revenue reveals that maximizing the station's revenue within the calculation period is equivalent to minimizing the sum of electricity sales losses due to water head loss in the water diversion tunnel and the water diversion tunnel construction investment. Therefore, the economic diameter of the water diversion tunnel is the tunnel diameter that minimizes the following formula.

[0059] Formula (Q1)

[0060] In formula (Q1):

[0061] Economic loss value;

[0062] The diameter of the water diversion tunnel is the independent variable.

[0063] Electricity sales losses due to head loss in the water diversion tunnel;

[0064] Investment in the construction of water diversion tunnel projects.

[0065] Analysis shows that there are losses in electricity sales. Y 1. Circumference of the water diversion tunnel D The relationship between them can be represented as:

[0066] Equation (Q2)

[0067] The diameter of the water diversion tunnel is Sometimes,

[0068] Formula (Q3)

[0069] In formula (Q3):

[0070] The calculation period assumes zero head loss in the water diversion tunnel and calculates electricity sales revenue.

[0071] The diameter of the water diversion tunnel is Electricity sales revenue included in the calculation period of head loss in the water diversion tunnel.

[0072] Calculate according to formula (Q3) Substituting this into formula (Q2) yields the following result.

[0073] Equation (Q4)

[0074] The construction investment for the water diversion tunnel project can be written as:

[0075] Formula (Q5)

[0076] In formula (Q5):

[0077] The sum of the costs for excavation and reinforcement of the rock tunnel lining of the water diversion tunnel;

[0078] The sum of all costs for the water diversion tunnel, excluding the cost of excavating the rock excavation and the cost of reinforcing the lining.

[0079] Analysis shows that, With the diameter of the water diversion tunnel DIt is proportional to the square of, that is:

[0080] Equation (Q6)

[0081] The diameter of the water diversion tunnel is At that time, there were:

[0082] Formula (Q7)

[0083] In formula (Q7):

[0084] The diameter of the water diversion tunnel is The sum of the costs of excavation of the water diversion tunnel rock excavation and the reinforcement of the lining steel.

[0085] Calculate according to formula (Q7) Substituting this into equation (Q6) yields...

[0086] Formula (Q8)

[0087] Analysis shows that, With the diameter of the water diversion tunnel D Proportional, that is:

[0088] Formula (Q9)

[0089] The diameter of the water diversion tunnel is At that time, there were:

[0090] Formula (Q10)

[0091] In formula (Q10):

[0092] The diameter of the water diversion tunnel is At that time, the sum of all other project costs for the water diversion tunnel, excluding the cost of excavating the rock excavation and the cost of reinforcing steel for the lining.

[0093] Calculate according to formula (Q10) Substituting this into formula (Q9) yields...

[0094] Formula (Q11)

[0095] Substituting formulas (Q8) and (Q11) into formula (Q5) yields the following result.

[0096] Formula (Q12)

[0097] Substituting formulas (Q4) and (Q12) into formula (Q1) yields the following result.

[0098] Formula (Q13)

[0099] In formula (Q13):

[0100] Y - Economic benefit loss value;

[0101] The preliminary selected diameter of the water diversion tunnel;

[0102] The calculation period assumes zero head loss in the water diversion tunnel and calculates electricity sales revenue.

[0103] The diameter of the water diversion tunnel is Electricity sales revenue included in the calculation period of head loss in the water diversion tunnel;

[0104] The diameter of the water diversion tunnel is The sum of the costs of excavation and reinforcement of the rock tunnel lining for the water diversion tunnel;

[0105] The diameter of the water diversion tunnel is At that time, the sum of all other expenses for the water diversion tunnel, excluding the cost of excavating the rock excavation and the cost of reinforcing the lining;

[0106] D - The diameter and independent variable of the water diversion tunnel.

[0107] According to formula (Q13), the economic benefit loss value is... Y The diameter of the water diversion tunnel corresponding to the minimum value. D This refers to the economic loophole.

[0108] Example 2: Specific application of the method of the present invention in the calculation of the economic diameter of the water diversion tunnel of a certain water diversion hydropower station.

[0109] A certain diversion-type hydroelectric power station has a water diversion tunnel length of 13,833m and a rated water diversion flow rate of 120m³ for power generation. 3 The flow rate is calculated as follows: / s, with a historical 33-year monthly average flow series; the grid-connected electricity price is US$0.05 / kWh; investment and returns are considered statically. The economic diameter of the water diversion tunnel is calculated as follows:

[0110] Step 1) Select 33 years as the calculation period for the economic diameter of the water diversion tunnel.

[0111] Step 2) The river runoff series is selected from the historical measured monthly average flow series of the river over 33 years.

[0112] Step 3) According to

[0113] Formula for calculating the tunnel diameter corresponding to the economic flow rate ;in The rated flow rate for water diversion for power generation at the hydropower station is taken as 120m. 3 / s; The economical flow velocity for the water diversion tunnel is taken as 3 m / s. Calculations show that... 7.136m.

[0114] Then, combining the engineering module, for Fine-tuning was performed, and finally the initial diameter of the water diversion tunnel was selected. D 0 = 7.20m.

[0115] Step 4) The diameter of the water diversion tunnel is D Given a depth of 0 = 7.20m, assuming zero head loss in the water diversion tunnel, the electricity sales revenue for the evaluation period can be calculated using the formula based on the river runoff series. A 0 = $851.1 million.

[0116] Step 5) The diameter of the water diversion tunnel is D With a depth of 0 = 7.20m, taking into account the head loss from the water diversion tunnel, the electricity sales revenue for the evaluation period can be calculated using the formula based on the river runoff series. B 0 = $835.6 million.

[0117] Step 6) The diameter of the water diversion tunnel is D When 0 = 7.20m, the sum of the cost of excavating the rock tunnel and the cost of reinforcing steel for the secondary lining can be calculated using the formula as follows: E 0 = $0.629 billion.

[0118] Step 7) The diameter of the water diversion tunnel is D With a depth of 0 = 7.20m, the sum of all costs for the water diversion tunnel, excluding the cost of rock excavation and the cost of steel reinforcement for the secondary lining, can be calculated using the formula. F 0 = $0.648 billion.

[0119] Step 8) Calculate the results D 0 = 7.20m A 0 = $851.1 million B 0 = $835.6 million E 0 = $0.629 billion and F Substituting 0 = $0.648 billion into the formula

[0120]

[0121] The economic loss value can be obtained through calculation. Y The diameter of the water diversion tunnel corresponding to the minimum value. D=6.388m, meaning the economical diameter of the water diversion tunnel for this diversion-type hydropower station is 6.388m. The relationship between different tunnel diameters and economic benefit losses is shown in [reference needed]. Figure 2 .

Claims

1. A method for calculating the economical diameter of a water diversion tunnel in a water diversion hydropower station, characterized in that: Includes the following steps: S1, the calculation period for the economic diameter of the water diversion tunnel is selected; S2, the river runoff series selected for the economic diameter calculation of the water diversion tunnel; S3, the initial diameter selected for calculating the economic diameter of the water diversion tunnel. D 0; Initial tunnel diameter D The method for selecting 0 is as follows: S3.1, Calculate the tunnel diameter corresponding to the economic flow velocity. ; S3.2, Select the adjusted value that conforms to the engineering module. Initial tunnel diameter D 0; The tunnel The calculation formula is: , The rated flow rate for water diversion for hydropower generation; The economical flow velocity for the water diversion tunnel is taken in the range of 3~5 m / s; S4, based on steps S1 and S2, calculate the initial tunnel diameter as follows: D 0. When the head loss of the water diversion tunnel is zero, the electricity sales revenue of the diversion-type hydropower station... A 0; S5, based on steps S1 and S2, calculate the initial tunnel diameter as follows: D 0. When the head loss in the water diversion tunnel is not zero, the electricity sales revenue of the diversion-type hydropower station... B 0; S6, calculate the initial tunnel diameter as D At 0:00, the sum of the rock excavation cost and the steel reinforcement cost for the secondary lining of the water diversion tunnel. E 0; S7, calculate the initial tunnel diameter as D At 0:00, the sum of all costs for the water diversion tunnel, excluding the cost of rock excavation and the cost of steel reinforcement for secondary lining. F 0; S8, Calculate the economic loss value of the diversion-type hydropower station according to the formula. Y The minimum value corresponds to the tunnel diameter D This is the economic tunnel; the formula is: The tunnel diameter corresponding to the minimum economic benefit loss value Y. D This refers to the economic loophole.

2. The method for calculating the economic diameter of a water diversion tunnel in a water diversion hydropower station according to claim 1, characterized in that: The calculation period in step S1 includes the construction period and the operation period.

3. The method for calculating the economical diameter of a water diversion tunnel in a water diversion hydropower station according to claim 1, characterized in that: The river runoff series in step S2 is selected from historically measured river runoff series.

4. The method for calculating the economical diameter of a water diversion tunnel in a water diversion hydropower station according to claim 1, characterized in that: In step S4, the electricity sales revenue of the diversion-type hydropower station... A The formula for calculating 0 is: ;in, n This represents the total number of time periods corresponding to the flow processes in the river runoff series. i For the first period of calculation i Each time period; For the first i The efficiency of the hydro-generator during a given time period; The specific weight of the water body; For the first i The total head of the power generation water diversion system during each time period; For the first i The sum of head losses in the power generation water diversion system excluding the water diversion tunnel during each time period; For the first i The water diversion flow for power generation during each time period; For the first i The length of each time period; For the first i Electricity prices for specific time periods; For the first i The discount factor for funds over a given period.

5. The method for calculating the economic diameter of a water diversion tunnel in a water diversion hydropower station according to claim 4, characterized in that: In step S5, the electricity sales revenue of the diversion-type hydropower station... B The formula for calculating 0 is: ; For the first i The head loss of the water diversion tunnel during a certain period.

6. The method for calculating the economical diameter of a water diversion tunnel in a water diversion hydropower station according to claim 1, characterized in that: In step S6, E The formula for calculating 0 is: , This refers to the amount of rock excavation work for the water diversion tunnel; The comprehensive unit price for rock excavation for water diversion tunnels; The amount of steel reinforcement for the secondary lining of the water diversion tunnel; The comprehensive unit price of steel reinforcement for the secondary lining of the water diversion tunnel.

7. The method for calculating the economic diameter of a water diversion tunnel in a water diversion hydropower station according to claim 1, characterized in that: F The formula for calculating 0 is: , m This represents the total number of other expense items; j For the first j item; For the first j The quantity of work for each item; For the first j The comprehensive unit price of the item.

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