Multi-year average temperature calculation method applied to different water depths of various reservoirs

Abstract

The invention relates to the technical field of reservoir water temperature measurement, in particular to a multi-year average temperature calculation method applied to different water depths of various reservoirs, which comprises the following steps of: 1, collecting basic data of the reservoirs, including reservoir depth classification, reservoir regulation types, a multi-year average value of annual average temperature of a reservoir location and latitude of the reservoir location; 2, based on the basic data collected in the step 1, a water temperature gradient parameter and a temperature cardinal number parameter are obtained through calculation; 3, according to the reservoir depth needing to be determined and the water temperature gradient parameters and the temperature cardinal number parameters obtained in the step 2, the average temperature of many years under the water depth is calculated and determined. According to the method, a linear calculation formula is adopted, the multi-year average reservoir temperature of different types of reservoirs under different water depth conditions can be rapidly and accurately determined, and an important calculation basis is provided for water taking cooling of the reservoirs and temperature distribution of reservoir dam structures.

Description

Technical Field

[0001] The invention relates to the technical field of reservoir water temperature measurement, and in particular to a multi-year average temperature calculation method applied to various reservoirs at different water depths. Background Art

[0002] With the development of the national digital economy, large data centers have higher and higher energy consumption requirements, and cooling systems need to be installed to remove the waste heat of data centers. The large reservoirs and hydropower stations under construction and already built in my country can be used as a good cooling source due to their low water temperature, meeting the cooling requirements of various systems to ensure the normal operation of equipment. Their significant energy-saving effects have become increasingly important as the country attaches importance to green and low-carbon energy.

[0003] The water temperature of reservoirs at different depths varies greatly. The temperature distribution has a great impact on the later dam deformation control and the technical water supply of the unit. At the same time, deep low-temperature reservoir water is an economical, simple and abundant natural cold source. However, how to set the reservoir water temperature before building the reservoir and reasonably arrange the elevation and plane position of the cooling water inlet is still a problem to be studied and solved. Summary of the invention

[0004] In view of the shortcomings in the prior art, the purpose of the present invention is to provide a calculation method that can analyze the water temperature of reservoirs at different depths in detail after inputting external parameters based on the basic information of the reservoir. It is based on the collection and organization of a large amount of data, statistically organizes the data, and linearly fits the data to obtain a method that can be used to calculate the water temperature of reservoirs at different depths of different types of reservoirs. It overcomes the high cost of using physical models and numerical modeling and the large error of empirical estimation, and improves the accuracy and speed of reservoir water temperature calculation.

[0005] To achieve the above object, the present invention is implemented by the following technical solutions:

[0006] A method for calculating multi-year average temperature at different water depths in various reservoirs includes the following steps:

[0007] Step 1: Collect basic data of reservoirs, including reservoir depth classification, reservoir regulation type, multi-year average annual temperature of the reservoir location, and latitude of the reservoir location;

[0008] Step 2: Based on the basic data collected in step 1, calculate the water temperature gradient parameter and the temperature base parameter;

[0009] Step 3: Calculate and determine the multi-year average temperature at the water depth according to the required reservoir depth and the water temperature gradient parameter and temperature base parameter obtained in step 2.

[0010] As a further optimization scheme of the present invention, in step 2, the value of the water temperature gradient parameter k is shown in the following formula (1):

[0011] k i =A×T cp + B (1)

[0012] Where, T cp —The multi-year average annual temperature of the reservoir location, in degrees Celsius, determined based on the data of the meteorological stations near the reservoir location; i—serial number, Specifically characterize the type of reservoir regulation;

[0013] The values ​​and meanings of i, the slope parameter A and the intercept parameter B are as follows:

[0014] When i=1, the reservoir regulation type is a deep reservoir with multi-year regulation, A=-0.0044, B=-0.0094N+0.2236;

[0015] When i = 2, the reservoir regulation type is a deep reservoir with annual regulation and incomplete multi-year regulation, A = -0.0051, B = -0.0096N + 0.2398;

[0016] When i=3, the reservoir regulation type is a deep reservoir with seasonal regulation and incomplete annual regulation, A=-0.0066, B=-0.0141N+0.3354;

[0017] When i=4, the reservoir regulation type is a shallow reservoir with seasonal regulation, A=-0.0088, B=-0.0189N+0.4472;

[0018] When i=5, the reservoir regulation type is a shallow reservoir with seasonal regulation, A=-0.0153, B=-0.033N+0.7826;

[0019] Where N is the latitude of the reservoir.

[0020] As a further optimization scheme of the present invention, when i=1, 2 or 3, the water depth of the deep reservoir is greater than 40m; when i=4, the water depth of the shallow reservoir is 40±2m; when i=5, the water depth of the shallow reservoir is within 30m.

[0021] As a further optimization scheme of the present invention, in step 2, the value of the temperature base parameter b is shown in the following formula (2):

[0022] b m =c×T cp + d (2)

[0023] In the formula, Specifically characterize the differences in reservoir regulation performance; T cp—The multi-year average annual temperature of the reservoir location, in degrees Celsius, determined based on data from meteorological stations near the reservoir location;

[0024] The values ​​and meanings of m, slope parameter c and intercept d are as follows:

[0025] When m=1, the reservoir regulation type is a multi-year regulation reservoir, c=0.4535, d=0.6384N-11.0380;

[0026] When m=2, the reservoir regulation type is an annual regulation reservoir, c=0.4535, d=0.6384N-5.8375;

[0027] When m=3, the reservoir regulation type is seasonal regulation reservoir, c=0.4535, d=0.6354N+1.2070;

[0028] Where N is the latitude of the reservoir.

[0029] As a further optimization scheme of the present invention, when m=2, the annual regulation reservoir includes an incomplete multi-year regulation reservoir; when m=3, the seasonal regulation reservoir includes an incomplete annual regulation reservoir.

[0030] As a further optimization scheme of the present invention, in step 3, the value of the multi-year average temperature t is shown in the following formula (3):

[0031] t=k×H+b (3)

[0032] In the formula: k is the water temperature gradient parameter, which means the water temperature rise value for every 1 meter increase in water depth, in units of ℃ / meter; b is the temperature base parameter, which is equivalent to the hypothetical surface water temperature of the reservoir when the water temperature is distributed according to a linear law, in units of ℃; H is the reservoir depth, in meters; t is the multi-year average temperature, in units of ℃.

[0033] Compared with the prior art, the present invention has the following beneficial effects:

[0034] (1) This method is based on a large amount of measured data for statistical analysis and obtains a calculation formula through linear fitting, which can more accurately reflect the variation of multi-year average temperature of different types of reservoirs under different water depth conditions. Compared with physical models and numerical modeling, this method is less expensive and avoids the large errors that may be caused by empirical estimates.

[0035] (2) This method uses a linear calculation formula, which can quickly and accurately determine the multi-year average reservoir temperature under different water depth conditions of different types of reservoirs, greatly improving the calculation efficiency and providing an important calculation basis for the temperature distribution of reservoir water intake cooling and reservoir dam structures.

[0036] (3) This method is applicable to reservoirs of different types and with different regulation performance, including deep reservoirs and shallow reservoirs, and multiple regulation types such as multi-year regulation, annual regulation, and seasonal regulation, and has wide applicability. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Figure 1 It is a specific flow chart of the method of the present invention.

[0038] Figure 2 It is a relative error diagram between the average measured water temperature at different water depths in the embodiment and the fitted water temperature obtained by the calculation formula. DETAILED DESCRIPTION

[0039] In order to enable those skilled in the art to better understand the technical solution of the present invention, the preferred implementation scheme of the present invention is described below in conjunction with specific embodiments, but it should not be understood as limiting the present invention and is only used as an example.

[0040] Reasonable and effective use of reservoir water temperature is the basis for reservoir-related design and water temperature utilization after completion. In order to solve the problem of reservoir water temperature calculation formula, Figure 1 As shown, the present invention provides a calculation method for analyzing the water temperature of reservoirs at different depths in detail after inputting external parameters based on basic reservoir information, which is described in detail as follows:

[0041] 1) The multi-year average temperature of different types of reservoirs at different water depths is calculated using the following formula:

[0042] t=k×H+b (3)

[0043] In the formula: k is the water temperature gradient, which means the water temperature rise for every 1 meter increase in water depth, in units of ℃ / meter; b is the temperature base, which is equivalent to the hypothetical surface water temperature of the reservoir when the water temperature is distributed according to a linear law, in units of ℃; H is the reservoir depth, in meters; t is the multi-year average temperature, in units of ℃.

[0044] 2) The value of the water temperature gradient parameter k is related to the depth of the reservoir, the reservoir regulation capacity, and the multi-year average annual temperature T of the reservoir location. cp , and the latitude N of the reservoir location are related, and the calculation formula is as follows:

[0045] k i =A×T cp + B (1)

[0046] Where, T cp —The multi-year average annual temperature of the reservoir location (℃), which can be determined based on the data of the meteorological station near the reservoir location; i—serial number, Specifically characterizing the reservoir type, the values ​​and meanings of i are shown in the first and second columns of Table 1 below.

[0047] The slope parameter A and intercept parameter B are determined as shown in the following table:

[0048] Table 1 Value table of slope parameter A and intercept B in the calculation formula of water temperature gradient parameter K

[0049]

[0050] The definitions of the terms in Table 1 are as follows:

[0051] Multi-year regulation: This type of reservoir can regulate water volume over multiple hydrological years, that is, it can store excess water in wet years and use it for water supply in dry years to balance the water volume changes over the years. This type of reservoir generally has a large capacity and can regulate water volume across multiple hydrological years to cope with extreme drought conditions.

[0052] Annual regulation: Annual regulation reservoirs can regulate water volume within a year, that is, they can store excess water during the flood season (usually summer or spring) for water supply during the dry season (usually winter or autumn). This type of reservoir is mainly used to regulate seasonal water volume changes to meet water demand throughout the year.

[0053] Seasonal regulation: Seasonal regulation reservoirs are mainly used to regulate seasonal water volume changes, usually within a shorter time scale (such as one quarter). This type of reservoir is suitable for areas where seasonal precipitation differences are obvious and water volume needs to be regulated in a short period of time.

[0054] Incomplete multi-year regulation: Incomplete multi-year regulation reservoirs have some multi-year regulation capacity, but not as strong as multi-year regulation reservoirs. Such reservoirs can regulate water flow to a certain extent across multiple hydrological years, but may not be sufficient to cope with consecutive years of drought.

[0055] Incomplete annual regulation: Incomplete annual regulation reservoirs are reservoirs that can regulate water volume to a certain extent throughout the year, but their regulation capacity is limited. This type of reservoir may not be able to fully balance water demand throughout the year, especially in drought years where water supply may be insufficient.

[0056] 3) The value of the temperature base parameter b is related to the reservoir regulation type and the multi-year average annual temperature T of the reservoir location. cp , and the latitude N of the reservoir location, the formula is as follows:

[0057] b m =c×T cp + d (2)

[0058] In the formula, Specifically representing the differences in reservoir regulation performance, the values ​​and meanings of m are shown in the first and second columns of Table 2 below.

[0059] The slope parameter c and the intercept parameter d are determined as shown in Table 2 below:

[0060] Table 2 Table of slope parameter c and intercept d values ​​in the temperature base b calculation formula

[0061]

[0062] The definitions of the terms in Table 2 refer to Table 1.

[0063] Example

[0064] Taking Reservoir A as an example, the specific implementation mode of the present invention is described in detail below.

[0065] Step 1: Collect basic data on reservoirs, including reservoir depth classification, reservoir regulation type, multi-year average annual temperature at the reservoir location, and latitude of the reservoir location.

[0066] Reservoir A is located in Hubei Province, China. The latitude of the reservoir dam site is 32.71 degrees north latitude (i.e. N = 32.71 degrees). The reservoir is an incomplete multi-year regulation deep water reservoir. The maximum water depth in front of the reservoir dam is about 155 meters. According to the depth of the reservoir, it is classified as a deep water reservoir. The average atmospheric temperature at the reservoir site is T cp =15.3℃.

[0067] Step 2, according to the multi-year average temperature calculation method applied to various reservoirs at different water depths, the value results of the water temperature gradient parameter k and the temperature base b are shown in Tables 1 and 2.

[0068] Reservoir A is a deepwater reservoir with incomplete multi-year regulation. The sequence number i in formula (1) is 2, the slope parameter A is -0.0051, and the intercept B is -0.0096N+0.2398=-0.0742. Therefore, the water temperature gradient parameter k is A×T cp +B = -0.1523.

[0069] Similarly, reservoir A is an incomplete multi-year regulation reservoir, and the sequence number m in formula (2) is 2. The values ​​of the slope parameter c and intercept d are: c = 0.4535, d = 0.6354N-5.8375 = 15.0454. Therefore, the value of the temperature base parameter b is b m =c×T cp +d=21.9840.

[0070] Step 3: Calculate the multi-year average temperature at the water depth according to the required reservoir depth and the water temperature gradient parameter and temperature base parameter obtained in step 2. The calculation formula is as follows:

[0071] t=k×H+b=-0.1523H+21.9840

[0072] Where H represents the water depth.

[0073] Continuous water temperature monitoring has been carried out for many years at different water depths of Reservoir A. The relative error between the measured average water temperature at different water depths and the water temperature obtained by the calculation formula is as follows: Figure 2 shown.

[0074] according to Figure 2 It shows that the relative error between the average measured water temperature of Reservoir A under different water depths and the fitted average water temperature obtained according to this method is generally within |±10%|, indicating that the calculation formula for deriving the water temperature at different water depths of each reservoir proposed by this method is generally reasonable.

[0075] In summary, the present invention provides an efficient, accurate, simple and cost-effective method for calculating reservoir water temperature, which has important reference value for reservoir-related design and operation.

[0076] The above are only preferred embodiments of the present invention. It should be noted that the above preferred embodiments should not be regarded as limiting the present invention, and the protection scope of the present invention should be based on the scope defined by the claims. For ordinary technicians in this technical field, several improvements and modifications can be made without departing from the spirit and scope of the present invention, and these improvements and modifications should also be regarded as the protection scope of the present invention.

Claims

1. A method for calculating the multi-year average temperature at different water depths in various reservoirs, characterized in that: The following steps are involved: Step 1: Collect basic data of reservoirs, including reservoir depth classification, reservoir regulation type, multi-year average annual temperature of the reservoir location, and latitude of the reservoir location; Step 2: Based on the basic data collected in step 1, calculate the water temperature gradient parameter and the temperature base parameter; Step 3: Calculate and determine the multi-year average temperature at the water depth according to the required reservoir depth and the water temperature gradient parameter and temperature base parameter obtained in step 2.

2. The method for calculating the multi-year average temperature at different water depths in various reservoirs according to claim 1 is characterized in that: In step 2, the value of the water temperature gradient parameter k is shown in the following formula (1): k i =A×T cp +B (1) In formula (1), T cp —The multi-year average annual temperature of the reservoir location, in degrees Celsius, determined based on the data of the meteorological stations near the reservoir location; i—serial number, Specifically characterize the type of reservoir regulation; The values ​​and meanings of i, the slope parameter A and the intercept parameter B are as follows: When i=1, the reservoir regulation type is a deep reservoir with multi-year regulation, A=-0.0044, B=-0.0094N+0.2236; When i = 2, the reservoir regulation type is a deep reservoir with annual regulation and incomplete multi-year regulation, A = -0.0051, B = -0.0096N + 0.2398; When i=3, the reservoir regulation type is a deep reservoir with seasonal regulation and incomplete annual regulation, A=-0.0066, B=-0.0141N+0.3354; When i=4, the reservoir regulation type is a shallow reservoir with seasonal regulation, A=-0.0088, B=-0.0189N+0.4472; When i=5, the reservoir regulation type is a shallow reservoir with seasonal regulation, A=-0.0153, B=-0.033N+0.7826; Where N is the latitude of the reservoir.

3. The method for calculating the multi-year average temperature at different water depths in various reservoirs according to claim 2 is characterized in that: When i=1, 2 or 3, the water depth of the deep reservoir is greater than 40m; when i=4, the water depth of the shallow reservoir is 40±2m; when i=5, the water depth of the shallow reservoir is within 30m.

4. The method for calculating multi-year average temperature at different water depths in various reservoirs according to claim 1 is characterized in that: In step 2, the value of the temperature base parameter b is shown in the following formula (2): b m =c×T cp + d (2) In formula (2), Specifically characterize the differences in reservoir regulation performance; T cp —The multi-year average annual temperature of the reservoir location, in degrees Celsius, determined based on data from meteorological stations near the reservoir location; The values ​​and meanings of m, slope parameter c and intercept d are as follows: When m=1, the reservoir regulation type is a multi-year regulation reservoir, c=0.4535, d=0.6384N-11.0380; When m=2, the reservoir regulation type is an annual regulation reservoir, c=0.4535, d=0.6384N-5.8375; When m=3, the reservoir regulation type is seasonal regulation reservoir, c=0.4535, d=0.6354N+1.2070; Where N is the latitude of the reservoir.

5. The method for calculating the multi-year average temperature at different water depths in various reservoirs according to claim 4 is characterized in that: When m=2, the annual regulation reservoir includes the incomplete multi-year regulation reservoir; when m=3, the seasonal regulation reservoir includes the incomplete annual regulation reservoir.

6. The method for calculating the multi-year average temperature at different water depths in various reservoirs according to claim 1 is characterized in that: In step 3, the value of the multi-year average temperature t is shown in the following formula (3): t=k×H+b (3) In formula (3), k is the water temperature gradient parameter, which indicates the increase of water temperature for every 1 meter increase of water depth, in units of °C / meter; b is the temperature base parameter, which is equivalent to the hypothetical surface water temperature of the reservoir when the water temperature is distributed according to a linear law, in units of °C; H is the reservoir depth, in units of meters; t is the multi-year average temperature, in units of °C.

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