Temperature control index optimization method in concrete dam pouring process

Abstract

The invention provides a method for optimizing a temperature control index in a concrete dam pouring process. The method comprises the following steps: firstly, determining an allowable concrete temperature rise value in the concrete pouring process; determining optimized concrete temperature control measure variables and upper and lower limit values of the variables in the concrete dam pouring process; then, a concrete temperature rise value calculation model in the pouring process is established; establishing a concrete pouring process temperature control cost function; and finally, according to the determined allowable temperature rise value in the concrete pouring process, the determined temperature control measure optimization variable upper and lower limit values, the established concrete temperature rise value calculation model in the pouring process and the established concrete temperature control cost function in the pouring process, temperature control measure variables in the concrete pouring process are optimized. According to the method, temperature control measures in the concrete pouring process are scientifically optimized, limitation of a traditional method is broken through, the temperature control effect, economic benefits and construction efficiency are comprehensively improved, and powerful technical support is provided for engineering construction.

Description

Technical Field

[0001] The invention relates to a method for optimizing temperature control measures, and in particular to a method for optimizing temperature control indicators in a concrete dam pouring process. Background Art

[0002] During the pouring of concrete dams, the temperature of concrete directly affects the quality, strength and overall effect of the dam structure. During the pouring process, the temperature of concrete needs to be controlled within a certain temperature range to avoid the coagulation and solidification of concrete due to excessively high or low concrete temperature. In the traditional pouring of concrete dams, the temperature regulation in the warehouse mainly relies on natural ventilation or simple spray cooling, which cannot be dynamically adjusted according to temperature changes. It often cannot meet the precise temperature control requirements required for the pouring of concrete dams, and is prone to overcooling or overheating. In addition, during the pouring process, the thermal conductivity and thickness of the insulation material also directly affect the temperature change of the concrete. However, traditional methods mostly rely on experience to select materials and lack scientific parameter optimization, which makes it difficult to balance the insulation effect and economic cost. The cost of temperature control measures is high, especially for large-scale projects. The increase in temperature control costs significantly affects the overall economic benefits of the project. Summary of the invention

[0003] In view of the above reasons, the purpose of the present invention is to provide a method for optimizing temperature control indicators during the pouring process of a concrete dam. The method optimizes three variables including the temperature in the warehouse, the thermal conductivity of the insulation material, and the thickness of the insulation material by constructing an accurate calculation model for the temperature rise value of concrete and a temperature control cost model, thereby achieving the best balance between the temperature control effect and the temperature control cost.

[0004] To achieve the above object, the present invention adopts the following technical solution: a method for optimizing temperature control index during concrete dam pouring, the method comprising:

[0005] S1. Determine the allowable concrete temperature rise value [ΔT2] during pouring;

[0006] S2. Determine the variables of concrete temperature control measures and upper and lower limits of the variables during the optimized pouring process;

[0007] The optimized variables of concrete temperature control measures are the air temperature in the warehouse, the thermal conductivity of the insulation material and the thickness of the insulation material;

[0008] S3, establishing a calculation model for the temperature rise value of concrete during pouring;

[0009] Combined with the influence of spraying measures and temporary insulation measures on the temperature rise during concrete pouring, a calculation model for the temperature rise value of concrete during concrete pouring is established:

[0010]

[0011] Where ΔT2 is the temperature rise of concrete during pouring; T ax is the temperature in the warehouse after spraying; T1 is the temperature of concrete entering the warehouse; T a is the temperature in the warehouse under natural conditions; R is solar radiation heat; β is the heat release coefficient of the concrete surface; φ1 is the temperature coefficient before unloading, φ1 = kτ, τ is the time from the concrete entering the warehouse to unloading; k is the empirical coefficient, with a value of 0.003; t is the time from unloading to the upper concrete covering; λ j h is the thermal conductivity of the insulation material during temporary insulation process; j is the thickness of the insulation material during the temporary insulation process; A1, A2, and A3 are the casting temperature recovery coefficients under the insulation measures, which are obtained by fitting according to the thermal conductivity of the insulation material at the project site, the thickness of the insulation material, and the insulation time. In the absence of a fitting formula, empirical values ​​can be used. A1 is 0.0014, A2 is 125.74, and A3 is 280.84;

[0012] Among them, the calculation formula for the temperature in the warehouse after spraying is as follows:

[0013]

[0014] Where, T a is the air temperature; ΔT iw is the temperature difference between the ambient temperature and the spray water temperature; ΔT r is the temperature increment of the object surface caused by solar radiation; is the temperature difference ratio; ΔT z It is the ambient temperature drop caused by water vapor evaporation;

[0015] Among them, according to the sprayer parameters adopted in the project, the temperature difference ratio The specific calculation formula is as follows:

[0016]

[0017] Where A, B, C, and D are the calculation parameters of the sprayer temperature difference ratio, which are obtained by fitting according to the wind speed and temperature at the project site. In the absence of a fitting formula, empirical values ​​can be used, where A is 0.57, B is 0.04, C is -2.40, and D is 1.25; Q w is the spray volume of the sprayer; V w is the wind speed at the outlet of the sprayer; D r is the diameter of the sprayer air outlet;

[0018] Among them, the ambient temperature decrease ΔT caused by water vapor evaporation z The calculation formula is as follows:

[0019]

[0020] Where m is the amount of water evaporated; α is the latent heat of vaporization of water. When water is around 25°C, the latent heat of vaporization is 2.45×10 -6 J / kg; ρ a is the density of air; V a is the volume of air covered by the spray, c a is the specific heat capacity of air;

[0021] S4. Establishing the concrete temperature control cost function during the pouring process;

[0022] According to the costs of concrete spraying measures and temporary insulation measures, the temperature control cost function P2 of the concrete pouring process is established:

[0023]

[0024] In the formula, p p The unit price of sprayer operation to reduce the ambient temperature of the warehouse surface by 1℃ includes labor cost and machine operation time cost; T a is the temperature outside the warehouse; T ax is the temperature in the silo; d1 is the total amount of concrete in a pouring silo during spray cooling; p j The construction cost of thermal insulation materials per square meter, including labor and machinery costs; b j is the unit price of thermal insulation material per square meter; a j h is the temporary insulation area of ​​the warehouse surface; j is the thickness of the insulation material; D j Total amount of concrete used for temporary insulation of thermal insulation materials;

[0025] S5. According to the concrete temperature recovery value allowed during the pouring process, a calculation model for the concrete temperature recovery value during the pouring process and a temperature control cost model are established to optimize the variables of the concrete temperature control measures during the pouring process;

[0026] S5.1 Divide the temperature control measure variable for concrete to be optimized determined in step S2 into n equal parts to obtain the temperature in the warehouse T used for calculation axi , divide the thickness of the insulation material n into equal parts to obtain the thickness of the insulation material h used for calculation yi ; Divide the thermal conductivity according to the thermal conductivity values ​​of different insulation materials to obtain the thermal conductivity λ of the insulation material used for calculation yi ;

[0027] S5.2 The temperature T in the warehouse used for calculation obtained in step S5.1 axi , thickness of insulation material h ji and thermal conductivity of insulation materials λ ji Perform permutations and combinations, substitute all permutation and combination data into the calculation model of concrete temperature recovery value during the pouring process established in step S3, and calculate the concrete temperature recovery value during the pouring process under each permutation and combination;

[0028] S5.3 When the concrete temperature rise value ΔT2 calculated in step S5.2 is less than or equal to the concrete temperature rise [ΔT2] allowed during the pouring process determined in step S1, the values ​​of the warehouse air temperature, insulation material thickness and insulation material thermal conductivity of the group combination are retained; otherwise, the group combination of variables is discarded;

[0029] S5.4 Since the unit price of insulation materials with different thermal conductivity is different, according to the purchase unit price of insulation materials on the project site, give each thermal conductivity value λ ji Insulation material determines a material unit price b ji ;

[0030] S5.5 calculates the temperature control costs of all variable combinations that meet the allowable concrete temperature rise value during the pouring process in step S5.3 based on the concrete temperature control cost function during the pouring process established in step S4, and selects the variable combination with the smallest temperature control cost as the optimized variable for the temperature control measures during the optimized concrete dam pouring process.

[0031] The allowable concrete temperature rise value [ΔT2] during the concrete dam pouring process is:

[0032] [ΔT2] = T2 - T1

[0033] Where, [ΔT2] is the allowable concrete temperature rise during the pouring process; T2 is the concrete pouring temperature specified in the temperature control technical requirements; T1 is the maximum value of the measured concrete entering the warehouse.

[0034] Wherein, the method for determining the upper limit and lower limit of the temperature in the warehouse;

[0035] T a·min ≤T ax ≤T a

[0036] Where, T ax is the target temperature in the warehouse; T a is the maximum temperature in the warehouse; T a·min is the lowest temperature in the warehouse;

[0037] Among them, the lowest temperature in the warehouse is T a·min The calculation formula is as follows:

[0038]

[0039] Where, T a is the maximum temperature in the warehouse; ΔT iw·max The temperature difference between the ambient temperature and the lowest water temperature used for spraying; ΔT r is the temperature increment of the object surface caused by solar radiation; is the temperature difference ratio; ΔTz is the temperature drop caused by water vapor evaporation;

[0040] Among them, according to the sprayer parameters adopted in the project, the temperature difference ratio The specific calculation formula is as follows:

[0041]

[0042] Where A, B, C, and D are the calculation parameters of the sprayer temperature difference ratio, which are obtained by fitting according to the wind speed and temperature at the project site. In the absence of a fitting formula, empirical values ​​can be used, where A is 0.57, B is 0.04, C is -2.40, and D is 1.25; Q w·max is the maximum spray volume of the sprayer; V w·max is the maximum wind speed at the sprayer outlet; D r is the diameter of the sprayer air outlet;

[0043] Among them, the ambient temperature decrease ΔT caused by water vapor evaporation z The calculation formula is as follows:

[0044]

[0045] Where m is the amount of water evaporated; α is the latent heat of vaporization of water. When water is around 25°C, the latent heat of vaporization can be taken as 2.45×10 -6 J / kg; ρ a is the density of air; V a is the volume of air covered by the spray, c a is the specific heat capacity of air;

[0046] The minimum temperature in the warehouse is 25℃;

[0047] The temperature collected naturally in the warehouse without any temperature control measures is taken as the upper limit value of the temperature in the warehouse T a .

[0048] Wherein, the method for determining the upper limit and lower limit of the thermal conductivity of the thermal insulation material is as follows:

[0049] The maximum thermal conductivity of the insulation material that can be selected is taken as the upper limit of the thermal conductivity of the insulation material, and the thermal conductivity of 0 when no temporary insulation measures are taken is taken as the lower limit of the thermal conductivity of the insulation material, that is:

[0050] 0≤λ jx ≤λ j·max

[0051] In the formula, λ jx is the target thermal conductivity of the temporary insulation process; λ j·max It is the maximum thermal conductivity of the insulation material during the temporary insulation process.

[0052] Wherein, the method for determining the upper limit and lower limit of the thickness of the thermal insulation material is:

[0053] The maximum thickness of the insulation material that can be selected is taken as the upper limit of the insulation material thickness. When no temporary insulation measures are taken, the insulation material thickness is 0, and the lower limit of the insulation material thickness is 0, that is:

[0054] 0≤h jx ≤h j·max

[0055] Among them, h jx The target thickness of the insulation material during the temporary insulation process; h j·max The maximum thickness of the insulation material for temporary insulation process. BRIEF DESCRIPTION OF THE DRAWINGS

[0056] Figure 1 This is a flow chart of the method for optimizing temperature control indicators during concrete dam pouring according to the present invention. DETAILED DESCRIPTION

[0057] The structure and features of the present invention are described in detail below in conjunction with the accompanying drawings and embodiments. It should be noted that various modifications can be made to the embodiments disclosed herein, and therefore, the embodiments disclosed in the specification should not be regarded as limiting the present invention, but are merely examples of embodiments, the purpose of which is to make the features of the present invention obvious.

[0058] like Figure 1 As shown, the temperature control index optimization method of the concrete dam pouring process of the present invention is:

[0059] S1. Determine the allowable concrete temperature rise value [ΔT2] during the pouring process.

[0060] In order to ensure the construction quality of concrete dam, the allowable concrete temperature rise value [ΔT2] during the pouring process is calculated according to the requirements of the temperature control technical requirements for concrete pouring temperature and the measured maximum concrete entering the warehouse. The specific calculation method is:

[0061] [ΔT2] = T2 - T1

[0062] Where, [ΔT2] is the allowable concrete temperature rise during the pouring process; T2 is the concrete pouring temperature specified in the temperature control technical requirements; T1 is the maximum value of the measured concrete entering the warehouse.

[0063] S2. Determine the variables and upper and lower limits of the concrete temperature control measures during the optimized pouring process.

[0064] During the pouring process, there are three main variables for optimizing concrete temperature control measures: the air temperature in the warehouse, the thermal conductivity of the insulation material, and the thickness of the insulation material.

[0065] S2.1. Determine the upper and lower limits of the temperature in the warehouse.

[0066] The lowest temperature in the casting bin after the spraying measures are taken is regarded as the lower limit of the temperature in the bin; without taking any temperature control measures, the temperature naturally collected in the bin is regarded as the upper limit of the temperature in the bin, that is:

[0067] T a·min ≤T ax ≤T a

[0068] Where, T ax is the target temperature in the warehouse; T a is the maximum temperature in the warehouse; T a·min The lowest temperature in the warehouse

[0069] Among them, the lowest temperature in the warehouse is T a·min The calculation formula is as follows:

[0070]

[0071] Where, T a is the maximum temperature in the warehouse; ΔT iw·max The temperature difference between the ambient temperature and the lowest water temperature used for spraying; ΔT r is the temperature increment of the object surface caused by solar radiation; is the temperature difference ratio; ΔT z The decrease in ambient temperature caused by the evaporation of water vapor.

[0072] Among them, according to the sprayer parameters adopted in the project, the temperature difference ratio The specific calculation formula is as follows:

[0073]

[0074] Where A, B, C, and D are the calculation parameters of the sprayer temperature difference ratio, which are obtained by fitting according to the wind speed and temperature at the project site. In the absence of a fitting formula, empirical values ​​can be used, where A is 0.57, B is 0.04, C is -2.40, and D is 1.25; Q w·max is the maximum spray volume of the sprayer; V w·max is the maximum wind speed at the sprayer outlet; D r is the diameter of the sprayer air outlet.

[0075] Among them, the ambient temperature decrease ΔT caused by water vapor evaporation z The calculation formula is as follows:

[0076]

[0077] Where m is the amount of water evaporated; α is the latent heat of vaporization of water. When water is around 25°C, the latent heat of vaporization can be taken as 2.45×10 -6 J / kg; ρ a is the density of air; V a is the volume of air covered by the spray, c a is the specific heat capacity of air.

[0078] In particular, according to relevant engineering specifications, spray measures should be adopted when the temperature in the casting bin is higher than 25°C. Therefore, if there are no special requirements in the project, the minimum temperature in the bin can be taken as 25°C.

[0079] S2.2 Determine the upper and lower limits of thermal conductivity of the insulation material.

[0080] The maximum thermal conductivity of the thermal insulation material that can be selected is taken as the upper limit of the thermal conductivity of the thermal insulation material, and the thermal conductivity is 0 when no temporary insulation measures are taken as the lower limit of the thermal conductivity of the thermal insulation material, that is:

[0081] 0≤λ jx ≤λ j·max

[0082] In the formula, λ jx is the target thermal conductivity of the temporary insulation process; λ j·max It is the maximum thermal conductivity of the insulation material during the temporary insulation process.

[0083] S2.3 Determine the upper and lower limits for the thickness of the insulation material.

[0084] The maximum thickness of the insulation material that can be selected is taken as the upper limit of the insulation material thickness, and the thickness of the insulation material is 0 when no temporary insulation measures are taken as the lower limit of the insulation material thickness, that is:

[0085] 0≤h jx ≤h j·max

[0086] Among them, h jx The target thickness of the insulation material during the temporary insulation process; h j·max The maximum thickness of the insulation material for temporary insulation process.

[0087] S3. Establish a calculation model for the temperature rise of concrete during the pouring process.

[0088] Combining the effects of spraying measures and temporary insulation measures on the temperature rise during concrete pouring, a calculation model for the temperature rise during concrete pouring is established:

[0089]

[0090] Where ΔT2 is the temperature rise of concrete during pouring; Tax is the temperature in the warehouse after spraying; T1 is the temperature of concrete entering the warehouse; T a is the temperature in the warehouse under natural conditions; R is solar radiation heat; β is the heat release coefficient of the concrete surface; φ1 is the temperature coefficient before closing the warehouse (φ1=kτ, τ is the time from concrete entering the warehouse to closing the warehouse; k is the empirical coefficient); h is the thickness of the insulation layer; λ is the thermal conductivity of the insulation material; t is the time from closing the warehouse to the upper concrete covering; λ j is the thermal conductivity of the temporary insulation process; h j is the thickness of the insulation material in the temporary insulation process; A1, A2, and A3 are the casting temperature recovery coefficients under insulation measures, which are obtained by fitting according to the thermal conductivity of the insulation material at the project site, the thickness of the insulation material and the insulation time. In the absence of a fitting formula, empirical values ​​can be used. A1 is 0.0014, A2 is 125.74, and A3 is 280.84.

[0091] Among them, the calculation formula for the temperature in the warehouse after spraying is as follows:

[0092]

[0093] Where, T a is the air temperature; ΔT iw is the temperature difference between the ambient temperature and the spray water temperature; ΔT r is the temperature increment of the object surface caused by solar radiation; is the temperature difference ratio; ΔT z The temperature drop caused by the evaporation of water vapor.

[0094] Among them, according to the sprayer parameters adopted in the project, the temperature difference ratio The specific calculation formula is as follows:

[0095]

[0096] Where A, B, C, and D are the calculation parameters of the sprayer temperature difference ratio, which are obtained by fitting according to the wind speed and temperature at the project site. In the absence of a fitting formula, empirical values ​​can be used, where A is 0.57, B is 0.04, C is -2.40, and D is 1.25; Q w is the spray volume of the sprayer; V w is the wind speed at the outlet of the sprayer; D r is the diameter of the sprayer air outlet.

[0097] Among them, the ambient temperature decrease ΔT caused by water vapor evaporation z The calculation formula is as follows:

[0098]

[0099] Where m is the amount of water evaporated; α is the latent heat of vaporization of water. When water is around 25°C, the latent heat of vaporization can be taken as 2.45×10 -6 J / kg; ρ a is the density of air; V a is the volume of air covered by the spray, c a is the specific heat capacity of air.

[0100] S4. Establish the temperature control cost function of the concrete pouring process.

[0101] According to the costs of concrete spraying measures and temporary insulation measures, the temperature control cost function P2 of the concrete pouring process is established:

[0102]

[0103] In the formula, p p The unit price of sprayer operation to reduce the ambient temperature of the warehouse surface by 1℃ includes labor cost and machine operation time cost; T a is the temperature outside the warehouse; T ax is the temperature in the silo; d1 is the total amount of concrete in a pouring silo during spray cooling; p j The construction cost of thermal insulation materials per square meter, including labor and machinery costs; b j is the unit price of thermal insulation material per square meter; a j h is the temporary insulation area of ​​the warehouse surface; j is the thickness of the insulation material; D j The total amount of concrete used for temporary insulation of thermal insulation materials.

[0104] S5. According to the allowable concrete temperature rise value during the pouring process, a calculation model for the concrete temperature rise value during the pouring process and a temperature control cost model are established to optimize the variables of the concrete temperature control measures during the pouring process.

[0105] Combined with the allowable temperature rise value during the concrete pouring process determined in step S1, the upper and lower limits of the temperature control measure optimization variables determined in step S2, the concrete temperature rise value calculation model during the pouring process established in step S3, and the concrete temperature control cost function during the pouring process established in step S4, the temperature control measure variables during the concrete pouring process are optimized. The specific steps are as follows:

[0106] S5.1 Divide the optimized variable of concrete temperature control measure determined in step S2 into n equal parts to obtain the temperature in the warehouse T used for calculation axi ; Divide the thickness of the insulation material n into equal parts to obtain the thickness of the insulation material h used for calculation yi ; Divide the thermal conductivity according to the thermal conductivity values ​​of different insulation materials to obtain the thermal conductivity λ of the insulation material used for calculation yi .

[0107] S5.2 The temperature T in the warehouse used for calculation obtained in step S5.1 axi , thickness of insulation material h ji and thermal conductivity of insulation materials λ ji Perform permutations and combinations, substitute all permutation and combination data into the temperature recovery value calculation model of the concrete pouring process established in step S3, and calculate the temperature recovery value of the concrete pouring process under each optimized combination.

[0108] S5.3 When the concrete pouring temperature recovery value ΔT2 calculated in step S5.2 is less than or equal to the allowable concrete temperature recovery [ΔT2] during the pouring process determined in step S1, the values ​​of the warehouse air temperature, insulation material thickness and thermal conductivity coefficient of the insulation material of this group of combinations are retained; conversely, when the calculated concrete pouring process temperature recovery value ΔT2 is greater than the allowable concrete temperature recovery value [ΔT2] during the pouring process determined in step S1, this group of variable combinations is discarded.

[0109] S5.4 Since the unit price of insulation materials with different thermal conductivity is different, according to the unit price of insulation materials purchased at the project site, give each thermal conductivity value λ ji Insulation material determines a material unit price b ji ;

[0110] S5.5 calculates the temperature control costs of all variable combinations that meet the allowable concrete temperature rise value during the pouring process in step S5.3 based on the concrete temperature control cost function during the pouring process established in step S4, and selects the variable combination with the smallest temperature control cost as the optimized variable for the temperature control measures during the optimized concrete dam pouring process.

[0111] Compared with the traditional temperature control measures during the concrete dam pouring process, the present invention has the following advantages:

[0112] 1. The present invention determines the upper and lower limits of the temperature in the warehouse by introducing a calculation model for the temperature in the warehouse, and can dynamically adjust the temperature in the warehouse according to environmental conditions and engineering requirements, avoiding the problem of overcooling or overheating that may occur in traditional methods; and comprehensively considers factors such as solar radiation, spray parameters, and water vapor evaporation, providing a scientific and reasonable basis for temperature control. 2. According to the actual situation of the project, the upper and lower limits of the thermal conductivity and thickness of the insulation material are set, and the insulation material is accurately selected through the optimization algorithm, so that it can meet the insulation requirements while minimizing the material cost and optimizing the insulation effect. The precise control of the thermal conductivity and thickness of the insulation material ensures the temperature stability of the concrete during the pouring process, avoiding the arbitrariness and uncertainty in the traditional method. 3. Combining the effects of spraying and insulation measures on temperature recovery, the present invention constructs a comprehensive temperature recovery calculation model. The model can accurately predict the temperature changes of concrete during the pouring process, including the temperature stabilization period and temperature recovery period after entering the warehouse, providing an accurate temperature control strategy to ensure the quality and strength of the concrete. 4. The present invention creates a temperature control cost function for the pouring process, calculates in detail the costs of spray cooling and temporary insulation measures, and finds the most economical temperature control measures through optimization calculation. While meeting the temperature control requirements, the temperature control cost is reduced to the maximum extent, the economy is improved, and the best balance between temperature control effect and economic benefit is achieved.

[0113] In summary, the present invention breaks through the limitations of traditional methods by scientifically optimizing temperature control measures during concrete pouring, achieves comprehensive improvement in temperature control effect, economic benefits and construction efficiency, and provides strong technical support for engineering construction.

[0114] Finally, it should be noted that the above-described embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit the present invention. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that the technical solutions described in the aforementioned embodiments may still be modified, or some or all of the technical features thereof may be replaced by equivalents. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for optimizing temperature control indexes during concrete dam pouring, characterized in that: The method is: S1. Determine the allowable concrete temperature rise value [ΔT2] during pouring; S2. Determine the variables of concrete temperature control measures and upper and lower limits of the variables during the optimized pouring process; The optimized variables of concrete temperature control measures are the air temperature in the warehouse, the thermal conductivity of the insulation material and the thickness of the insulation material; S3, establishing a calculation model for the temperature rise value of concrete during pouring; Combined with the influence of spraying measures and temporary insulation measures on the temperature rise during concrete pouring, a calculation model for the temperature rise value of concrete during concrete pouring is established: Where ΔT2 is the temperature rise of concrete during pouring; T ax is the temperature in the warehouse after spraying; T1 is the temperature of concrete entering the warehouse; T a is the temperature in the warehouse under natural conditions; R is solar radiation heat; β is the heat release coefficient of the concrete surface; φ1 is the temperature coefficient before unwinding, φ1 = kτ, τ is the time from the concrete entering the warehouse to unwinding; k is the empirical coefficient, with a value of 0.003; t is the time from unwinding to the upper concrete covering; λ j h is the thermal conductivity of the insulation material during temporary insulation process; j is the thickness of the insulation material during the temporary insulation process; A1, A2, and A3 are the casting temperature recovery coefficients under the insulation measures, and the empirical values ​​are A1, 0.0014, A2, 125.74, and A3, 280.84; Among them, the calculation formula for the temperature in the warehouse after spraying is as follows: Where, T a is the air temperature; ΔT iw is the temperature difference between the ambient temperature and the spray water temperature; ΔT r is the temperature increment of the object surface caused by solar radiation; is the temperature difference ratio; ΔT z It is the ambient temperature drop caused by water vapor evaporation; Among them, according to the sprayer parameters adopted in the project, the temperature difference ratio The specific calculation formula is as follows: Where A, B, C, and D are the calculation parameters of the sprayer temperature difference ratio. The empirical values ​​are A is 0.57, B is 0.04, C is -2.40, and D is 1.25; Q w is the spray volume of the sprayer; V w is the wind speed at the outlet of the sprayer; D r is the diameter of the sprayer air outlet; Among them, the ambient temperature decrease ΔT caused by water vapor evaporation z The calculation formula is as follows: Where m is the amount of water evaporated; α is the latent heat of vaporization of water. When water is around 25°C, the latent heat of vaporization is 2.45×10 -6 J / kg; ρ a is the density of air; V a is the volume of air covered by the spray, c a is the specific heat capacity of air; S4. Establishing the concrete temperature control cost function during the pouring process; According to the costs of concrete spraying measures and temporary insulation measures, the temperature control cost function P2 of the concrete pouring process is established: In the formula, p p The unit price of sprayer operation to reduce the ambient temperature of the warehouse surface by 1℃ includes labor cost and machine operation time cost; T a is the temperature outside the warehouse; T ax is the temperature in the silo; d1 is the total amount of concrete in a pouring silo during spray cooling; p j The construction cost of thermal insulation materials per square meter, including labor and machinery costs; b j is the unit price of thermal insulation material per square meter; a j h is the temporary insulation area of ​​the warehouse surface; j is the thickness of the insulation material; D j Total amount of concrete used for temporary insulation of thermal insulation materials; S5. According to the concrete temperature recovery value allowed during the pouring process, a calculation model for the concrete temperature recovery value during the pouring process and a temperature control cost model are established to optimize the variables of the concrete temperature control measures during the pouring process; S5.1 Divide the temperature control measure variable for concrete to be optimized determined in step S2 into n equal parts to obtain the temperature in the warehouse T used for calculation axi , divide the thickness of the insulation material n into equal parts to obtain the thickness of the insulation material h used for calculation yi ; Divide the thermal conductivity according to the thermal conductivity values ​​of different insulation materials to obtain the thermal conductivity λ of the insulation material used for calculation yi ; S5.2 The temperature T in the warehouse used for calculation obtained in step S5.1 axi , thickness of insulation material h ji and thermal conductivity of insulation material λ ji Perform permutations and combinations, substitute all permutation and combination data into the calculation model of concrete temperature recovery value during the pouring process established in step S3, and calculate the concrete temperature recovery value during the pouring process under each permutation and combination; S5.3 When the concrete temperature rise value ΔT2 calculated in step S5.2 is less than or equal to the concrete temperature rise [ΔT2] allowed during the pouring process determined in step S1, the values ​​of the warehouse air temperature, insulation material thickness and insulation material thermal conductivity of the group combination are retained; otherwise, the group combination of variables is discarded; S5.4 Since the unit price of insulation materials with different thermal conductivity is different, according to the purchase unit price of insulation materials on the project site, give each thermal conductivity value λ ji Insulation material determines a material unit price b ji ; S5.5 calculates the temperature control costs of all variable combinations that meet the allowable concrete temperature rise value during the pouring process in step S5.3 based on the concrete temperature control cost function during the pouring process established in step S4, and selects the variable combination with the smallest temperature control cost as the optimized variable for the temperature control measures during the optimized concrete dam pouring process.

2. The method for optimizing temperature control index during concrete dam pouring according to claim 1, characterized in that: The allowable concrete temperature rise value [ΔT2] during the concrete dam pouring process is: [ΔT2] = T2 - T1 Where, [ΔT2] is the allowable concrete temperature rise during the pouring process; T2 is the concrete pouring temperature specified in the temperature control technical requirements; T1 is the maximum value of the measured concrete entering the warehouse.

3. The method for optimizing temperature control index during concrete dam pouring according to claim 1, characterized in that: A method for determining the upper and lower limits of the temperature in the warehouse; T a·min ≤T ax ≤T a Where, T ax is the target temperature in the warehouse; T a is the highest temperature in the warehouse; T a·min is the lowest temperature in the warehouse; Among them, the lowest temperature in the warehouse is T a·min The calculation formula is as follows: Where, T a is the maximum temperature in the warehouse; ΔT iw·max The temperature difference between the ambient temperature and the lowest water temperature used for spraying; ΔT r is the temperature increment of the object surface caused by solar radiation; is the temperature difference ratio; ΔT z is the temperature drop caused by water vapor evaporation; Among them, according to the sprayer parameters adopted in the project, the temperature difference ratio The specific calculation formula is as follows: Where A, B, C, and D are the calculation parameters of the sprayer temperature difference ratio, which are obtained by fitting according to the wind speed and temperature at the project site. In the absence of a fitting formula, empirical values ​​can be used, where A is 0.57, B is 0.04, C is -2.40, and D is 1.25; Q w·max is the maximum spray volume of the sprayer; V w·max is the maximum wind speed at the sprayer outlet; D r is the diameter of the sprayer air outlet; Among them, the ambient temperature decrease ΔT caused by water vapor evaporation z The calculation formula is as follows: Where m is the amount of water evaporated; α is the latent heat of vaporization of water. When water is around 25°C, the latent heat of vaporization can be taken as 2.45×10 -6 J / kg; ρ a is the density of air; V a is the volume of air covered by the spray, c a is the specific heat capacity of air; The minimum temperature in the warehouse is 25℃; The temperature collected naturally in the warehouse without any temperature control measures is taken as the upper limit value of the temperature in the warehouse T a .

4. The method for optimizing temperature control index during concrete dam pouring according to claim 1, characterized in that: The method for determining the upper limit and lower limit of the thermal conductivity of the thermal insulation material is as follows: The maximum thermal conductivity of the insulation material that can be selected is taken as the upper limit of the thermal conductivity of the insulation material. When no temporary insulation measures are taken, the thermal conductivity of the insulation material is 0, and 0 is taken as the lower limit of the thermal conductivity of the insulation material, that is: 0≤λ jx ≤λ j·max In the formula, λ jx is the target thermal conductivity of the temporary insulation process; λ j·max It is the maximum thermal conductivity of the insulation material during the temporary insulation process.

5. The method for optimizing temperature control index during concrete dam pouring according to claim 1, characterized in that: The method for determining the upper limit and lower limit of the thickness of the thermal insulation material is as follows: The maximum thickness of the insulation material that can be selected is taken as the upper limit of the insulation material thickness. When no temporary insulation measures are taken, the insulation material thickness is 0, and 0 is taken as the lower limit of the insulation material thickness, that is: 0≤h jx ≤h j·max Among them, h jx The target thickness of the insulation material during the temporary insulation process; h j·max The maximum thickness of the insulation material for temporary insulation process.

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