A full-life carbon reduction optimization method and system for a prefabricated composite exterior wall of recycled building materials

Abstract

The present invention provides a method and system for optimizing carbon reduction throughout the life cycle of a prefabricated composite exterior wall made of recycled building materials. For the composite wall combination schemes of prefabricated composite exterior walls made of various recycled building materials, by establishing a carbon emission optimization method that comprehensively covers the entire life cycle from production, transportation, construction, use to demolition, the carbon emissions throughout the life cycle of the recycled building materials of the prefabricated composite exterior wall can be calculated more accurately and comprehensively. The precise calculation method of the carbon emissions of building materials throughout the life cycle is improved and optimized. Combining the number of uses of the recycled building materials, the total carbon emissions in the production, construction and demolition stages throughout the life cycle are accurately calculated to ensure the comprehensiveness of the environmental impact analysis. This method can continuously optimize the selection and combination of the recycled building materials of the exterior wall according to the different materials and environmental conditions of each layer on the exterior wall, ensuring the lowest carbon emissions while meeting the building function requirements, and improving the application efficiency of the recycled building materials in the building.

Description

Technical Field

[0001] The present invention belongs to the technical field of carbon reduction optimization design for green buildings, and particularly relates to a method and system for carbon reduction optimization of the whole life cycle of a prefabricated composite exterior wall made of recycled building materials. Background Art

[0002] With the intensification of global climate change problems, the construction industry, as one of the main sources of carbon emissions, recycled building materials not only reduce the dependence on natural resources by recycling construction waste or industrial by-products, but also reduce carbon emissions during the material production process. At the same time, prefabricated buildings have gradually become the direction of green buildings due to their advantages such as fast construction speed, stable quality, and less construction pollution. Combining the use and repeated utilization of green and environmentally friendly recycled building materials with prefabricated composite exterior wall systems can effectively reduce the carbon footprint of buildings throughout their life cycle. Through the whole life cycle analysis of prefabricated composite exterior walls made of recycled building materials, optimizing various links such as material selection, construction, and demolition methods can minimize carbon emissions to the greatest extent.

[0003] Chinese Patent CN115796657A discloses a method, system, and electronic device for calculating the carbon reduction amount of green building materials. This method can quickly and accurately calculate the carbon reduction amount of the functional unit of green building materials by constructing a carbon emission reduction quantification model based on the carbon footprint report of green building materials, improving the integrity and accuracy of the carbon footprint calculation of green building materials.

[0004] In the paper "Analysis of Carbon Emissions and Carbon Reduction Effects of 3D-Printed Buildings Based on the LCA Method [J]. Journal of Safety and Environment, Vol. 23, No. 7" by Meng Qingcheng et al., for the evaluation of carbon emissions and carbon reduction effects of 3D-printed buildings, a full life cycle assessment method is used to define the carbon emission calculation model of 3D-printed buildings, and a comparative analysis is conducted on the carbon emissions during the materialization stage of 3D-printed construction, traditional construction, and conventional green construction methods.

[0005] In the paper "Research on the Carbon Emission Intensity and Carbon Reduction Potential of the Resource Utilization of Subway Shield Muck [J]. Environmental Engineering, 2023, 41(7): 53-60" by Li Wei et al., a carbon emission evaluation method for the utilization and disposal of subway shield muck is constructed based on the LCA method. Taking a tunnel section of Shenzhen Metro Line 13 as an example, the resource utilization process and system of shield muck are sorted out, the management path of on-site resource utilization of muck is clarified, and the carbon emission intensity and carbon reduction potential of muck utilization and disposal are quantified.

[0006] However, the above-mentioned existing technologies generally have the following problems:

[0007] 1) The existing technology 1 gives the accounting method for the production stage of green building materials, but does not consider the actual carbon emissions in the whole life cycle and based on the material combination scenarios of each layer on the prefabricated composite exterior wall.

[0008] 2) The prior art 2 compared the production, transportation, and construction stages of 3D printing and traditional construction methods, but did not consider the differences in the operation stage and the reuse of recycled materials.

[0009] 3) The prior art 3 conducted a quantitative study on subway shield muck, and carried out quantitative analysis by comparing different disposal methods, but did not consider the performance of non-fired bricks.

[0010] It can be seen from this that the current carbon emission quantification model for green building materials mainly focuses on the carbon footprint in the production stage, but fails to cover the carbon emissions throughout the life cycle of recycled building materials during the reuse process. Moreover, the carbon emission calculation method is generally not accurate enough, ignoring the differences in carbon emission contributions of recycled building materials and ordinary building materials during the construction, demolition, and reuse stages. This makes the assessment of the entire life cycle not comprehensive and accurate enough, and is not conducive to the adjustment of emission reduction strategies. And because the enclosure structure performance of different building facades is different, their deterioration and loss will also be different, resulting in different carbon emissions in the building operation stage. Therefore, for various combination schemes of "recycled building materials + prefabricated composite facades", it is necessary to accurately evaluate the carbon emissions in the production, construction, use, and demolition stages of recyclable recycled building materials, and comprehensively evaluate the 50-year life cycle carbon emission intensity and carbon reduction potential of different recycled building material combination schemes. Summary of the Invention

[0011] (1) Technical problems to be solved

[0012] Aiming at the fact that the prior art mainly focuses on the carbon emission accounting in the building material production stage and fails to comprehensively cover the entire life cycle from production, transportation, construction, use to demolition. In addition, the prior methods do not consider the number of reuse times of recycled building materials throughout the life cycle, making the calculation of carbon emissions inaccurate. Moreover, during the use of building materials, due to the difference in the heat insulation performance of different facade combination schemes, the carbon emission differences in the building operation stage are not fully considered. For this reason, the present invention proposes an optimization method for the carbon emissions throughout the life cycle of recycled building materials for prefabricated composite facades, which accurately calculates the carbon emissions in each stage, and combines a dynamic optimization algorithm of the material use times and deterioration rate to continuously optimize the combination scheme of recycled building materials, achieving the lowest carbon emissions throughout the life cycle, ultimately effectively reducing the carbon footprint of buildings, and promoting green buildings and sustainable development.

[0013] (2) Technical solutions

[0014] The present invention discloses an optimization method for carbon emission reduction throughout the life cycle of recycled building materials for prefabricated composite facades, including the following steps:

[0015] Step 1: Establish a recycled building material resource library to construct prefabricated composite facades of recycled building materials with different combination methods. The recycled building material resource library includes parameter information of various facing materials, various thermal insulation materials, and various structural load-bearing materials;

[0016] Step 2: Calculate the carbon emissions \(E\) during the production stage of the prefabricated composite exterior wall made of recycled building materials p ;

[0017] Step 3: Calculate the carbon emissions \(E\) during the transportation stage of the prefabricated composite exterior wall made of recycled building materials t ;

[0018] Step 4: Calculate the carbon emissions \(E\) during the construction stage of the prefabricated composite exterior wall made of recycled building materials C ;

[0019] Step 5: Calculate the carbon emissions \(E\) during the demolition stage of the prefabricated composite exterior wall made of recycled building materials D ;

[0020] Step 6: Calculate the number of times \(T\) of the whole life cycle usage of different prefabricated composite exterior walls made of recycled building materials, and calculate the total carbon emissions \(E\) of production, construction, and demolition during the whole life cycle ptc ;

[0021] \(E\) ptc \(=\)(\(E\) P +\(E\) t +\(E\) c +\(E\) D )\(\times T\)

[0022] Step 7: Calculate the carbon emissions \(E\) during the whole life cycle usage stage of the prefabricated composite exterior wall made of recycled building materials use ;

[0023] Step 8: Calculate the total carbon emissions \(E\) of the prefabricated composite exterior wall made of recycled building materials during the whole life cycle, and optimize the objective function \(E\) total , and obtain the scheme to minimize the prefabricated composite exterior wall made of recycled building materials total Preferably, in Step 2, it specifically includes: During the process of carbon emission reduction optimization in the whole life cycle of the building, the carbon emissions during the production stage of different recycled building material exterior walls are crucial. \(E\)

[0024] P mainly includes the carbon emissions \(E\) of recycled building material production P1 and the carbon emissions \(E\) of prefabricated composite exterior wall production P2 , and its calculation expression is:

[0025]

[0026] \(E\) P \(=\) \(E\) P1 +\(E\) P2 Among them, \(E\) P1 represents the carbon emissions of recycled building material production, and \(E\) P2 represents the carbon emissions of prefabricated composite exterior wall production;

[0027] Step 2.2: The carbon emissions of each recycled building material during the production process, and its calculation expression \(E\) P1is:

[0028] E P1 = M i × C i + M j × C j + M k × C k

[0029] Wherein, M i 、M j 、M k represent the weights of the i-th type of finishing material, the j-th type of thermal insulation material, and the k-th type of structural load-bearing material of the recycled building materials, and C i 、C j 、C k respectively represent the production carbon emission coefficients of the finishing material, the thermal insulation material, and the structural load-bearing material of the prefabricated composite exterior wall of the recycled building materials;

[0030] Step 2.3: The calculation expression of the production carbon emission of the prefabricated composite exterior wall E P2 is:

[0031] E P2 = RM i,j,k × C i,j,k

[0032] Wherein, RM i,j,k represents the building material consumption of the prefabricated composite exterior wall combination scheme of the i, j, k types of recycled building materials, and C i,j,k represents the production carbon emission coefficient of the combination scheme of the prefabricated composite exterior wall of the i, j, k types of recycled building materials of the i-th type of finishing material.

[0033] Preferably, step 3 specifically includes:

[0034] Step 3.1: The carbon emission E t of the prefabricated composite exterior wall made of recycled building materials should include the carbon emission E t1 during the transportation of the recycled building materials and the carbon emission E t2 during the transportation of the prefabricated composite exterior wall. The calculation expression is:

[0035] E t = E t1 + E t2

[0036] Wherein, E t1 is the carbon emission during the transportation of the recycled building materials, and E t2 is the carbon emission during the transportation of the prefabricated composite exterior wall;

[0037] Step 3.2: The calculation expression of the carbon emission during the transportation stage of the recycled building materials is:

[0038] E t1 = Mi ×D R_i ×ET + M j ×D R_j ×ET + M k ×D R_k ×ET

[0039] Among them, D R_i , D R_j , D R_k respectively represent the average transportation distance of recycled building materials of the i-th finishing material, the j-th thermal insulation material, and the k-th structural load-bearing material. ET represents the carbon emission factor per unit weight transportation distance;

[0040] Step 3.3: The calculation expression for the transportation carbon emission of the prefabricated composite exterior wall is:

[0041] E t2 = M i,j,k ×D C_i,j,k ×ET

[0042] Among them, M i,j,k represents the weight of the prefabricated composite exterior wall of i, j, k types of recycled building materials, and D C_i,j,k represents the average transportation distance of the prefabricated composite exterior wall combination plan of i, j, k types of recycled building materials.

[0043] Preferably, step 4 specifically includes:

[0044] Step 4.1: The carbon emission E C during the construction stage of the prefabricated composite exterior wall of recycled building materials includes the carbon emission E C1 from the energy consumption of construction machinery, the carbon emission E C2 from construction water use and drainage, and the carbon emission E C3 from construction waste during the construction stage. Its calculation expression is:

[0045] E C = E C1 + E C2 + E C3

[0046] Step 4.2: The calculation expression for the carbon emission from the energy consumption of construction machinery is:

[0047]

[0048] Among them, n is the total number of all construction machinery and equipment, E C1 represents the total carbon emission of construction machinery energy consumption, f(M i,j,k ) represents the influence of the exterior wall weight M i,j,k on the mechanical working efficiency, that is, as the exterior wall weight changes, the working time required by the construction machinery will change accordingly. F iDenote the energy consumption per unit time of the $i$-th mechanical equipment as $EF$. i Denote the energy carbon emission factor of the $i$-th mechanical equipment.

[0049] Step 4.3: The carbon emission calculation expression for construction water use and drainage is:

[0050]

[0051] Wherein, Denote the water volume used in the construction process of the $ijk$-th type of exterior wall, and $EF$ w Denote the carbon emission factor of construction water use in the construction stage. Denote the water volume of drainage in the construction process of the $ijk$-th type of exterior wall, and $EF$ sw Denote the carbon emission factor of construction drainage in the construction stage.

[0052] Step 4.4: The carbon emission calculation expression for construction waste is:

[0053]

[0054] Wherein, $m$ is the number of all types of construction waste. Denote the waste generation amount of the $i$-th building material generated by the $ijk$-th type of exterior wall. Denote the average transportation distance of the $i$-th building material waste generated by the $ijk$-th type of exterior wall. $ET$ denotes the carbon emission factor per unit weight of transportation distance, and $EF$ proc Denote the carbon emission factor for construction waste treatment.

[0055] Preferably, step 5 specifically includes:

[0056] Step 5.1: The carbon emission $E$ in the demolition stage D Includes the energy consumption carbon emission $E$ of demolition machinery D1 And the carbon emission $E$ of building waste transportation D2 , and its calculation expression is:

[0057] $E$ D =$E$ D1 +$E$ D2

[0058] Step 5.2: The energy consumption carbon emission of demolition machinery depends on the energy consumed by the machinery during demolition. This energy consumption is related to the weight $M$ of the exterior wall i,j,k The $E$ D1 Its calculation expression is:

[0059]

[0060] Wherein, $q$ is the total number of all demolition machinery and equipment. represents the total working time required for the i-th demolition mechanical equipment to demolish the ijk-th type of exterior wall, which is related to the weight M of the exterior wall i,j,k and F zi is related, F zi represents the energy consumption per unit time of the i-th demolition mechanical equipment, and EF zi represents the energy carbon emission factor of the i-th demolition mechanical equipment;

[0061] Step 5.3: The carbon emission of transporting construction demolition waste is related to the weight M of the exterior wall i,j,k is related, and its E D2 The calculation formula is:

[0062]

[0063] Among them, represents the average transportation distance of the garbage generated by the ijk-th type of exterior wall, and ET represents the carbon emission factor per unit weight transportation distance.

[0064] Preferably, the calculation method of the full-life usage times T in step 6 includes the following steps (a) to (h):

[0065] (a) Prepare multiple groups of prefabricated combined exterior wall samples of recycled building materials, set different environmental conditions, and conduct experiments under these conditions. Use an environmental test chamber to control temperature and humidity, regularly measure the heat preservation performance of the samples, and record the data at each time point;

[0066] (b) Calculate the change of the heat preservation performance at each time point relative to the initial value. Assume that the initial heat preservation performance value is P o , and the heat preservation performance value at the i-th time point is P i , and the time is t i , and its calculation formula is as follows:

[0067]

[0068] Among them, ΔP i represents the relative change of the heat preservation performance at the i-th time point, P i represents the heat preservation performance value at the i-th time point, and P o represents the initial heat preservation performance value;

[0069] (c) Fit the deterioration rate. Assume that the deterioration of the heat preservation performance follows an exponential model, that is, the change of the heat preservation performance with time conforms to exponential decay, and its calculation formula is as follows:

[0070] P(t) = P0e -kt

[0071] Substitute the relative change into the exponential decay model and take logarithmic linearization, and its calculation formula is as follows:

[0072]

[0073] Among them, k represents the deterioration rate constant, and t i represents the time at the i-th time point;

[0074] (d) Data fitting. By linear regression fitting, determine the deterioration rate constant k under different environmental conditions. Its calculation formula is as follows:

[0075]

[0076] x = t i

[0077] y = -kx

[0078] (e) Determine the Arrhenius equation parameters. Using the deterioration rate constant k at different temperatures, obtain the activation energy E through Arrhenius equation fitting a and the frequency factor A. Its calculation formula is as follows:

[0079]

[0080] Take the logarithm for linearization. Its calculation formula is as follows:

[0081]

[0082] Take ln(k) at different temperatures and as data points, and perform linear regression fitting to obtain the slope m and the intercept b. Its calculation formula is as follows:

[0083]

[0084] b = ln(A)

[0085] Among them, k represents the deterioration rate constant, A represents the frequency factor, E a represents the activation energy, R represents the gas constant, taking 8.314 J / (mol·K), T represents the absolute temperature, m represents the slope of the linear regression fitting, and b represents the intercept of the linear regression fitting;

[0086] (f) Use the actual environmental temperature T use to calculate the deterioration rate constant k in the actual environment use ;

[0087]

[0088] Among them, k use represents the deterioration rate constant in the actual environment, and T use represents the actual environmental temperature;

[0089] (g) Calculate the service life t of the material in the actual environment according to the degradation rate constant k use The calculation formula is as follows: use

[0090]

[0091] where t use represents the service life of the material in the actual environment, unit: year;

[0092] (h) Calculate the number of usage times within the full 50-year cycle according to the service life t of the material use

[0093]

[0094] where is the rounding function, that is, taking the largest integer not exceeding the real number x, T represents the total service life usage times of the material within the full 50-year cycle, and t use represents the service life of the material in the actual environment.

[0095] Preferably, step 7 specifically includes:

[0096] Step 7.1: Calculate the annual heat conduction energy consumption in winter. Refer to the outdoor and indoor design temperature values in winter in various regions provided in the "Code for Design of Heating, Ventilation and Air Conditioning of Civil Buildings" GB 50736-2012 in China, and determine it through the heat transfer amount of the exterior wall. The calculation formula is as follows:

[0097] Q cold_cond = U×A×(20℃ - (-5℃))×24×90÷1000

[0098] where Q cold_cond represents the annual heat conduction energy consumption of the prefabricated composite exterior wall of recycled building materials in winter, U represents the heat transfer coefficient of the prefabricated composite exterior wall of recycled building materials, and A represents the area of the exterior wall;

[0099] Step 7.2: Calculate the annual heat conduction energy consumption in summer. Refer to the outdoor and indoor design temperature values in summer in various regions provided in the "Code for Design of Heating, Ventilation and Air Conditioning of Civil Buildings" GB 50736-2012 in China, and determine it through the heat transfer amount of the exterior wall. The calculation formula is as follows:

[0100] Q hot_cond = U×A×(35℃ - 26℃)×24×90÷1000

[0101] where Q hot_cond represents the annual heat conduction energy consumption of the prefabricated composite exterior wall of recycled building materials in summer;

[0102] ​​Step 7.3: Calculate the carbon emissions during the whole life cycle usage stage of the prefabricated composite exterior wall made of recycled building materials, where E use The calculation formula is as follows:

[0103] E use =(Q cold_cond +Q hot_cond )×50×T Q

[0104] Among them, E use represents the carbon emissions during the whole life cycle usage stage of the prefabricated composite exterior wall made of recycled building materials, and T Q represents the carbon emission coefficient.

[0105] Preferably, step 8 specifically includes:

[0106] Define the objective function. The total carbon emissions during the whole life cycle can be expressed as the following objective function:

[0107] E total =E ptc +E use

[0108] Select an initial combination plan for the recycled building material exterior protection structure Calculate its total carbon emissions:

[0109]

[0110] Through an iterative method, gradually adjust the material selection with the aim of reducing E total . The objective function value after each iteration can be expressed as:

[0111]

[0112] Among them, δ is the learning rate or step size factor, which controls the adjustment amplitude during each iteration, and are the partial derivatives of the carbon emissions of each part;

[0113] The iterative process continues until the convergence condition is met:

[0114]

[0115] Among them, ∈ is a very small preset value. When the change in the total carbon emissions is less than this value, it is considered that the optimal solution has been found;

[0116] Through the above steps, find the plan for the prefabricated composite exterior wall made of recycled building materials that minimizes E total The formula is as follows:

[0117] ​

[0118] Then this solution realizes the minimization of carbon emissions throughout the life cycle.

[0119] On the other hand, the present invention also discloses a carbon emission reduction optimization system for the whole life cycle of a prefabricated composite exterior wall of recycled building materials, including: at least one processor; and at least one memory communicatively connected to the processor, wherein: the memory stores program instructions executable by the processor, and the processor can execute the carbon emission reduction optimization method for the whole life cycle of the prefabricated composite exterior wall of recycled building materials described in any one of the above by invoking the program instructions.

[0120] (III) Beneficial effects

[0121] Compared with the prior art, the carbon emission reduction optimization method and system for the whole life cycle of the prefabricated composite exterior wall of recycled building materials provided by the present invention have the following beneficial effects:

[0122] (1) For the prefabricated composite exterior wall combination schemes of various recycled building materials, the present invention establishes an optimization method for carbon emissions throughout the life cycle covering production, transportation, construction, use to demolition, and based on the life cycle analysis (LCA) method, more accurately and comprehensively calculates the carbon emissions throughout the life cycle of recycled building materials during the reuse process, can effectively reduce the carbon emissions of buildings throughout the life cycle, realize the minimization of carbon emissions, and significantly reduce the impact on the environment.

[0123] (2) The present invention proposes a method for dynamically optimizing the exterior wall combination scheme based on an iterative algorithm, which can continuously optimize the exterior wall design according to different materials and environmental conditions to ensure the lowest carbon emissions while meeting the building function requirements.

[0124] (3) The present invention optimizes the accurate calculation method for the carbon emissions of building materials throughout the life cycle, combines the number of uses of recycled building materials, and calculates the total carbon emissions in the production, construction, and demolition stages throughout the life cycle to ensure the comprehensiveness of the environmental impact analysis.

[0125] (4) By optimizing the selection and combination of recycled building materials, the present invention improves the application efficiency of recycled building materials in buildings and promotes the wide application and popularization of recycled building materials. Description of the drawings

[0126] In order to more clearly illustrate the technical solutions in the present invention or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the drawings in the following description are some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0127] Figure 1It is the main flowchart of the whole-life carbon reduction optimization method for the prefabricated composite exterior wall of recycled building materials provided by the present invention. Detailed implementation manners

[0128] To make the objectives, technical solutions and advantages of the present invention clearer, the technical solutions in the present invention will be clearly and completely described below with reference to the accompanying drawings in the present invention. Apparently, the described embodiments are some but not all of the embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art without making creative efforts based on the embodiments in the present invention belong to the scope of protection of the present invention.

[0129] The present invention designs a whole-life carbon reduction optimization method and system for the prefabricated composite exterior wall of recycled building materials.

[0130] See Figure 1 As shown, the whole-life carbon reduction optimization method for the prefabricated composite exterior wall of recycled building materials of the present invention specifically includes the following steps:

[0131] Step 1: Establish a recycled building material resource library to construct prefabricated composite exterior walls of recycled building materials with different combinations. The recycled building material resource library includes parameter information of various facing materials, various thermal insulation materials, and various structural load-bearing materials.

[0132] In another embodiment, the recycled building material resource library in Step 1 specifically includes:

[0133] Facing material (i): The types include recycled bricks, recycled ceramics, recycled wood, recycled metal plates, etc. The parameters of the i-th facing material include the carbon emission coefficient C i (unit: kgCO2e / unit building material quantity), and the thermal conductivity f ki (unit: W / m·K).

[0134] Thermal insulation material (j): The types include recycled polystyrene (EPS), recycled polyurethane (PUR), recycled glass wool, recycled rock wool, etc. The parameters of the j-th thermal insulation material include the carbon emission coefficient C j (unit: kgCO2e / unit building material quantity), and the thermal conductivity f kj (unit: W / m·K).

[0135] Structural load-bearing material (k): The types include recycled concrete, recycled steel bars, recycled wood, recycled composite materials, etc. The parameters of the k-th structural load-bearing material include the carbon emission coefficient C k (unit: kgCO2e / unit building material quantity), and the thermal conductivity f kk (unit: W / m·K).

[0136] Based on the recycled building material resource library, a prefabricated composite exterior wall of recycled building materials with different combinations is constructed. When the selected finishing material is the i-th type, the thermal insulation material is the j-th type, and the structural load-bearing material is the k-th type, the plan for the prefabricated composite exterior wall of recycled building materials is W i,j,k 。

[0137] Step 2: Calculate the carbon emissions E during the production stage of the prefabricated composite exterior wall of recycled building materials p 。

[0138] In another embodiment, step 2 specifically includes:

[0139] Step 2.1: In the process of carbon emission reduction optimization throughout the building's life cycle, the carbon emissions during the production stage of different recycled building material exterior walls are crucial, and its E P mainly includes the carbon emissions E P1 during the production of recycled building materials and the carbon emissions E P2 during the production of the prefabricated composite exterior wall. The calculation expression is:

[0140] E P = E P1 + E P2

[0141] where E P represents the carbon emissions during the production stage of the prefabricated composite exterior wall of recycled building materials (unit: kgCO2), E P1 represents the carbon emissions during the production of recycled building materials (unit: kgCO2), and E P2 represents the carbon emissions during the production of the prefabricated composite exterior wall (unit: kgCO2).

[0142] Step 2.2: The carbon emissions during the production process of each type of recycled building material, and its calculation expression E P1 is:

[0143] E P1 = M i × C i + M j × C j + M k × C k

[0144] where M i , M j , M k represent the weights of the i-th type of finishing material, the j-th type of thermal insulation material, and the k-th type of structural load-bearing material of the recycled building materials (unit: tons, t), and C i , C j , C k respectively represent the production carbon emission coefficients of the finishing material, thermal insulation material, and structural load-bearing material of the prefabricated composite exterior wall of recycled building materials (unit: kgCO2e / t).

[0145] Step 2.3: Calculation expression E of carbon emissions in the production of prefabricated composite exterior walls P2 is as follows:

[0146] E P2 = RM i,j,k × C i,j,k

[0147] wherein, RM i,j,k represents the building material consumption (unit: t) of the prefabricated composite exterior wall combination plan of i, j, k types of recycled building materials, and C i,j,k represents the production carbon emission coefficient (unit: kgCO2e / t) of the prefabricated composite exterior wall combination plan of i, j, k types of recycled building materials with the i-th facing material.

[0148] Step 3: Calculate the carbon emissions E during the transportation stage of the prefabricated composite exterior wall made of recycled building materials t .

[0149] In another embodiment, step 3 specifically includes:

[0150] Step 3.1: The carbon emissions E of the prefabricated composite exterior wall made of recycled building materials t should include the carbon emissions E during the transportation stage of the recycled building materials t1 and the carbon emissions E during the transportation of the prefabricated composite exterior wall t2 , and its calculation expression is:

[0151] E t = E t1 + E t2

[0152] wherein, E t is the total carbon emissions during the transportation of the prefabricated composite exterior wall made of recycled building materials (unit: kgCO2), E t1 is the carbon emissions during the transportation of the recycled building materials (unit: kgCO2), and E t2 is the carbon emissions during the transportation of the prefabricated composite exterior wall (unit: kgCO2)

[0153] Step 3.2: The calculation expression of the carbon emissions during the transportation stage of the recycled building materials is:

[0154] E t1 = M i × D R_i × ET + M j × D R_j × ET + M k × D R_k × ET

[0155] wherein, D R_i , D R_j , D R_kIt represents the average transportation distance (unit: km) of the recycled building materials of the i-th finishing material, the j-th insulation material and the k-th structural load-bearing material respectively. The above-mentioned longer transportation distance refers to the distance from the building materials manufacturer to the assembly factory. The transportation distance is probably within a province or a city. ET represents the carbon emission factor per unit weight of transportation distance (unit: kgCO2 / (t·km)).

[0156] Step 3.3: The calculation expression for carbon emissions from transportation of assembled composite exterior walls is:

[0157] E t2 =M i,j,k ×D C_i,j,k ×ET

[0158] Among them, M i,j,k Indicates the weight of the assembled exterior wall of recycled building materials of type i, j, k (unit: t), D C_i,j,k It represents the average transportation distance (unit: km) of the assembled exterior wall combination schemes of type i, j, and k recycled building materials. This shorter transportation distance refers to the distance from the assembly factory to the construction site, which is generally within a city.

[0159] Step 4: Calculate the carbon emissions E during the construction phase of the assembled exterior wall made of recycled building materials C .

[0160] In another embodiment, step 4 specifically includes:

[0161] Step 4.1: Carbon emissions from the construction phase of the recycled building material assembled composite exterior wall C Including carbon emissions from energy consumption of construction machinery E C1 , Carbon emissions from construction water and drainage E C2 , Carbon emissions from construction waste during the construction phase E C3 , its calculation expression is:

[0162] E C =E C1 +E C2 +E C3

[0163] Step 4.2: The carbon emission calculation expression of construction machinery energy consumption is:

[0164]

[0165] Where n is the total number of all construction machinery and equipment, E C1 Represents the total carbon emissions of construction machinery energy consumption (unit: kgCO2e), f(M i,j,k ) represents the weight of the exterior wall M i,j,kThe impact on the mechanical working efficiency, i.e., as the weight of the exterior wall changes, the working time required by the mechanical equipment will change accordingly, F i represents the energy consumption per unit time of the i-th type of mechanical equipment (unit: KWh / hour), EF i represents the energy carbon emission factor of the i-th type of mechanical equipment (unit: kgCO2e / KWh).

[0166] Step 4.3: The carbon emission calculation expression for construction water use and drainage is:

[0167]

[0168] Among them, represents the water consumption during the construction of the ijk-th type of exterior wall (unit: ton or cubic meter), EF w represents the carbon emission factor of construction water use during the construction stage (unit: kgCO2e / t), represents the drainage volume during the construction of the ijk-th type of exterior wall (unit: ton or cubic meter), EF sw represents the carbon emission factor of construction drainage during the construction stage (unit: kgCO2e / t).

[0169] Step 4.4: The carbon emission calculation expression for construction waste is:

[0170]

[0171] Among them, m is the number of all types of construction waste, represents the waste generation amount of the i-th building material generated by the ijk-th type of exterior wall (unit: t), represents the average transportation distance of the i-th building material waste generated by the ijk-th type of exterior wall (unit: kilometer (km)), ET represents the carbon emission factor per unit weight transportation distance (unit: kgCO2e / (t·km)), EF proc represents the carbon emission factor of construction waste treatment (unit: kg CO2e / ton).

[0172] Step 5: Calculate the carbon emission E of the prefabricated composite exterior wall made of recycled building materials during the demolition stage D .

[0173] In another embodiment, step 5 specifically includes:

[0174] Step 5.1: The carbon emission E during the demolition stage D includes the energy consumption carbon emission E of the demolition machinery D1 and the carbon emission E of the construction waste transportation D2 , and its calculation expression is:

[0175] E D = ED1 +E D2

[0176] Step 5.2: The energy consumption carbon emissions of the demolition machinery depend on the energy consumed by the machinery and equipment during the demolition process, and this energy consumption is related to the weight M of the exterior wall i,j,k related, and its E D1 The calculation formula is:

[0177]

[0178] where q is the total number of all demolition machinery and equipment, represents the total working time required for the i-th demolition machinery and equipment to demolish the exterior wall of the ijk type, which is related to the weight M of the exterior wall i,j,k and F zi related, and this function represents the relationship between weight and working time, F zi represents the energy consumption per unit time of the i-th demolition machinery and equipment (unit: KWh / hour), and EF zi represents the energy carbon emission factor of the i-th demolition machinery and equipment (unit: kgCO2e / KWh).

[0179] Step 5.3: The carbon emissions of transporting construction demolition waste are related to the weight M of the exterior wall i,j,k related, and its E D2 The calculation formula is:

[0180]

[0181] where, represents the average transportation distance of the waste generated by the exterior wall of the ijk type (unit: kilometer (km)), and ET represents the carbon emission factor per unit weight transportation distance (unit: kgCO2e / (t·km)).

[0182] Step 6: Calculate the number of times T of the whole life cycle use of different prefabricated composite exterior walls made of recycled building materials, and calculate the total carbon emissions E of the whole life cycle production, construction, and demolition ptc .

[0183] In another embodiment, step 6 specifically includes:

[0184] According to the number of times T of the whole life cycle use estimated through sample experiments, calculate the total carbon emissions of the whole life cycle production, construction, and construction of different recycled building material composite exterior walls

[0185] E ptc =(E P +E t +E c +E D )×T

[0186] where, Eptc is the total carbon emissions during the whole life cycle of production, construction, and construction of different prefabricated combined exterior walls of recycled building materials (unit: kgCO2).

[0187] The calculation method of the total life cycle usage times T includes the following steps (a) to (h):

[0188] (a) Prepare multiple groups of prefabricated combined exterior wall samples of recycled building materials, set different environmental conditions (such as different temperatures, humidities, ultraviolet intensities, etc.), and conduct experiments under these conditions. An environmental test chamber can be used to control the temperature and humidity, regularly measure the heat insulation performance of the samples (such as thermal conductivity or heat insulation effect), and record the data at each time point. For example:

[0189] Measure the heat insulation performance every 100 hours at 70°C and 50% humidity.

[0190] Measure the heat insulation performance every 200 hours at 50°C and 70% humidity.

[0191] Measure the heat insulation performance every 500 hours at 25°C and 100% humidity.

[0192] (b) Calculate the change in the heat insulation performance at each time point relative to the initial value. Assume the initial heat insulation performance value is P o , and the heat insulation performance value at the i-th time point is P i , and the time is t i , and its calculation formula is as follows:

[0193]

[0194] where, ΔP i represents the relative change in the heat insulation performance at the i-th time point, P i represents the heat insulation performance value at the i-th time point (unit: W / m 2 ·K), and P o represents the initial heat insulation performance value (unit: W / m 2 ·K).

[0195] (c) Fit the deterioration rate. Assume that the deterioration of the heat insulation performance follows an exponential model, that is, the change in the heat insulation performance over time conforms to exponential decay, and its calculation formula is as follows:

[0196] P(t) = P0e -kt

[0197] Substitute the relative change into the exponential decay model and take logarithmic linearization, and its calculation formula is as follows:

[0198]

[0199] where, k represents the deterioration rate constant, ti Represents the time at the i-th time point.

[0200] (d) Data fitting. By linear regression fitting, determine the degradation rate constant k under different environmental conditions. Its calculation formula is as follows:

[0201]

[0202] x = t i

[0203] y = -kx

[0204] (e) Determine the Arrhenius equation parameters. Using the degradation rate constant k at different temperatures, obtain the activation energy E through Arrhenius equation fitting a and the frequency factor A. Its calculation formula is as follows:

[0205]

[0206] Take the logarithm for linearization. Its calculation formula is as follows:

[0207]

[0208] Take ln(k) at different temperatures and as data points, perform linear regression fitting to obtain the slope m and the intercept b. Its calculation formula is as follows:

[0209]

[0210] b = ln(A)

[0211] where k represents the degradation rate constant, A represents the frequency factor, E a represents the activation energy, R represents the gas constant, which can be taken as 8.314 J / (mol·K), T represents the absolute temperature (K), m represents the slope of the linear regression fitting, and b represents the intercept of the linear regression fitting.

[0212] (f) Use the actual environmental temperature T use to calculate the degradation rate constant k in the actual environment use .

[0213]

[0214] where k use represents the degradation rate constant in the actual environment, and T use represents the actual environmental temperature (K).

[0215] (g) According to the degradation rate constant k use calculate the life t of the material in the actual environment use, the calculation formula is as follows:

[0216]

[0217] Among them, t use represents the service life of the material in the actual environment (unit: year).

[0218] (h) Calculate the number of uses within the full 50-year cycle according to the service life t of the material use of the material.

[0219]

[0220] Among them, is the rounding function, that is, taking the largest integer not exceeding the real number x, T represents the total service life usage times of the material within the full 50-year cycle, and t use represents the service life of the material in the actual environment.

[0221] Step 7: Calculate the carbon emission E of the prefabricated composite exterior wall of recycled building materials during the full service life usage stage use .

[0222] In another embodiment, step 7 specifically includes:

[0223] Step 7.1: Calculate the annual heat conduction energy consumption in winter. Refer to the outdoor and indoor design temperature values in winter in various regions provided in the "Code for Design of Heating, Ventilation and Air Conditioning of Civil Buildings" GB 50736-2012 in China, and determine it through the heat transfer amount of the exterior wall. The calculation formula is as follows:

[0224] Q cold_cond = U × A × (20°C - (-5°C)) × 24 × 90 ÷ 1000

[0225] Among them, Q cold_cond represents the heat conduction energy consumption of the prefabricated composite exterior wall of recycled building materials in winter (unit: kW), U represents the heat transfer coefficient of the prefabricated composite exterior wall of recycled building materials (unit: W / (m2·K)), U is related to the thermal conductivities f ki of the three-layer exterior wall materials, f kj of the three-layer exterior wall materials, f kk of the three-layer exterior wall materials, A represents the area of the exterior wall (unit: m 2 2).

[0226] Step 7.2: Calculate the annual heat conduction energy consumption in summer. Refer to the outdoor and indoor design temperature values in summer in various regions provided in the "Code for Design of Heating, Ventilation and Air Conditioning of Civil Buildings" GB 50736-2012 in China, and determine it through the heat transfer amount of the exterior wall. The calculation formula is as follows:

[0227] Q hot_cond= U × A × (35°C - 26°C) × 24 × 90 ÷ 1000

[0228] Among them, Q hot_cond represents the heat conduction energy consumption of the prefabricated combined exterior wall of recycled building materials in summer (unit: kW).

[0229] Step 7.3: Calculate the carbon emission of the prefabricated combined exterior wall of recycled building materials during the whole life cycle usage stage, and its E use The calculation formula is as follows:

[0230] E use = (Q cold_cond + Q hot_cond ) × 50 × T Q

[0231] Among them, E use represents the carbon emission of the prefabricated combined exterior wall of recycled building materials during the whole life cycle usage stage, and T Q represents the carbon emission coefficient (unit: kgCO2e / kw).

[0232] Step 8: Calculate the total carbon emission E total of the prefabricated combined exterior wall of recycled building materials during the whole life cycle, and optimize the objective function E total to obtain the scheme for minimizing the prefabricated combined exterior wall of recycled building materials.

[0233] In another embodiment, step 8 specifically includes:

[0234] Define the objective function. The total carbon emission during the whole life cycle can be expressed as the following objective function:

[0235] E total = E ptc + E use

[0236] Select an initial combined scheme of the recycled building material exterior protection structure Calculate its total carbon emission:

[0237]

[0238] Through an iterative method, gradually adjust the material selection or other variables, aiming to reduce E total . The objective function value after each iteration can be expressed as:

[0239]

[0240] Among them, δ is the learning rate or step size factor, which controls the adjustment amplitude during each iteration, and are the partial derivatives of the carbon emissions of each part.

[0241] The iterative process continues until the convergence condition is met:

[0242]

[0243] where ∈ is a very small preset value. When the change in the total carbon emissions is less than this value, it is considered that the optimal solution has been found.

[0244] Through the above steps, a solution that minimizes E total for the prefabricated composite exterior wall of recycled building materials is found The formula is as follows:

[0245]

[0246] Then this solution achieves the minimization of the carbon emissions over the entire life cycle.

[0247] It can be seen from this that through the above steps 1 - 8, for the prefabricated composite exterior wall combination schemes of various recycled building materials, the present invention establishes an optimization method for carbon emissions over the entire life cycle that comprehensively covers from production, transportation, construction, use to demolition. It calculates more accurately and comprehensively the carbon emissions over the entire life cycle of the recycled building materials of the prefabricated composite exterior wall during the reuse process, improves and optimizes the accurate calculation method for the carbon emissions over the entire life cycle of building materials, combines the number of times of use of the recycled building materials over the entire life cycle, calculates the total carbon emissions during the production, construction and demolition stages over the entire life cycle, ensures the comprehensiveness of the environmental impact analysis. This method can continuously optimize the selection and combination of the recycled building materials for the exterior wall according to the different materials and environmental conditions of each layer on the exterior wall, ensure the lowest carbon emissions while meeting the building function requirements, and improve the application efficiency of the recycled building materials in the building.

[0248] In summary, the key innovative contents of the method for optimizing carbon emissions reduction over the entire life cycle of the prefabricated composite exterior wall of recycled building materials of the present invention include the following:

[0249] (1) The present invention provides an optimization method for carbon emissions over the entire life cycle. For the prefabricated composite exterior wall of recycled building materials, through the accurate calculation and optimization of the carbon emissions covering the entire life cycle of the recycled building materials from production, transportation, construction, use to demolition, the minimization of the carbon emissions over the entire life cycle of the building is finally achieved. This method ensures that a combination scheme of the exterior wall with the minimum carbon emissions over the entire life cycle can be found, thus minimizing the carbon footprint of the building to the greatest extent.

[0250] (2) The present invention introduces the number of times in the whole life cycle to calculate the carbon emissions in the whole life cycle of production, construction and demolition. Through experiments and model fitting, it predicts the service life of recycled building materials under different environments and calculates the number of times of use within the set cycle. Combining the carbon emission calculations in stages such as production, construction and demolition, it comprehensively evaluates the total carbon emissions in the whole life cycle. This method ensures a comprehensive consideration of the long-term performance and environmental impact of building materials and directly affects the final carbon reduction effect.

[0251] (3) The present invention proposes an iterative optimization method. By gradually adjusting the selection and use of materials, it optimizes the exterior wall combination plan to ensure the minimization of the total carbon emissions in the whole life cycle. This dynamic adjustment and optimization strategy helps to achieve precise whole life cycle carbon emission management.

[0252] In several embodiments provided by the optimization method of the present invention, the functional units in each step can be integrated in a controller processing unit, or each unit can exist physically alone, or two or more units can be integrated in one unit. The above integrated units can be implemented in the form of hardware or in the form of a combination of hardware and software functional units. The integrated units implemented in the form of software functional units can be stored in a computer-readable storage medium. The above software functional units stored in a storage medium include several instructions for causing a computer device (which can be a personal computer, a server, or a network device, etc.) or a processor to execute some steps of the methods described in the various embodiments of the present invention. The aforementioned storage medium includes: various media such as USB flash drives, mobile hard disks, read-only memory (ROM), random access memory (RAM), magnetic disks or optical discs that can store program codes.

[0253] The present invention also discloses a whole life cycle carbon reduction optimization system for an assembled composite exterior wall of recycled building materials, including: at least one processor; and at least one memory communicatively connected to the processor, wherein: the memory stores program instructions executable by the processor, and the processor can execute the whole life cycle carbon reduction optimization method for the assembled composite exterior wall of recycled building materials as described above by invoking the program instructions.

[0254] Finally, it should be noted that: the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that: they can still modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements for some of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the various embodiments of the present invention.

Claims

1. A method for optimizing carbon reduction throughout the life cycle of a prefabricated composite exterior wall made of recycled building materials, characterized in that, It includes the following steps: Step 1: Establish a recycled building material resource library to construct prefabricated composite exterior walls of recycled building materials with different combinations. The recycled building material resource library includes parameter information of various facing materials, various thermal insulation materials, and various structural load-bearing materials. Specifically, the recycled building material resource library includes: Finishing materials: types include recycled bricks, recycled ceramics, recycled wood and recycled metal panels. The parameters of the i-th finishing material include the carbon emission coefficient C i , thermal conductivity f ki ; Thermal insulation materials: The types include recycled polystyrene, recycled polyurethane, recycled glass wool, and recycled rock wool. The parameters of the j-th thermal insulation material include the carbon emission coefficient C j , and the thermal conductivity f kj ; Structural load-bearing materials: The types include recycled concrete, recycled steel bars, recycled wood, and recycled composite materials. The parameters of the k-th structural load-bearing material include the carbon emission coefficient C k , thermal conductivity f kk ; Based on the recycled building material resource library, a prefabricated composite exterior wall of recycled building materials with different combinations is constructed. When the selected finishing material is the i-th type, the thermal insulation material is the j-th type, and the structural load-bearing material is the k-th type, the scheme of its prefabricated composite exterior wall of recycled building materials is W i,j,k ; Step 2: Calculate the carbon emissions E during the production stage of the prefabricated composite exterior wall made of recycled building materials p ; Step 3: Calculate the carbon emissions E during the transportation stage of the prefabricated composite exterior wall of recycled building materials t ; Step 4: Calculate the carbon emissions E during the construction stage of the prefabricated composite exterior wall of recycled building materials C ; Step 5: Calculate the carbon emissions E during the demolition stage of the prefabricated composite exterior wall of recycled building materials D ; Step 6: Calculate the full-life usage times T of different prefabricated composite exterior walls made of recycled building materials, and calculate the total carbon emissions E during the entire life cycle of production, construction, and demolition ptc ; E ptc = (E P + E t + E c + E D ) × T The calculation method of the total service life usage times T includes the following steps (a) to (h): (a) Prepare multiple groups of prefabricated composite exterior wall samples of recycled building materials, set different environmental conditions, and conduct experiments under these conditions. Use an environmental test chamber to control temperature and humidity, regularly measure the thermal insulation performance of the samples, and record the data at each time point; (b) Calculate the change in the heat preservation performance at each time point relative to the initial value, assuming the initial heat preservation performance value is P o , and the heat preservation performance value at the i-th time point is P i , the time is t i , and its calculation formula is as follows: Among them, ΔP i represents the relative change in heat preservation performance at the i-th time point, and P i represents the heat preservation performance value at the i-th time point, and P o represents the initial heat preservation performance value; (c) Fit the deterioration rate. Assume that the deterioration of the thermal insulation performance follows an exponential model, that is, the change of the thermal insulation performance with time conforms to exponential decay, and its calculation formula is as follows: P(t) = P0e -kt Substitute the relative change into the exponential decay model and take logarithmic linearization. Its calculation formula is as follows: where k represents the deterioration rate constant, and t i represents the time at the i-th time point; (d) Data fitting. Through linear regression fitting, determine the deterioration rate constant k under different environmental conditions. Its calculation formula is as follows: x = t i y = -kx (e) Determine the Arrhenius equation parameters. Using the degradation rate constants k at different temperatures, the activation energy E is obtained by fitting through the Arrhenius equation a and the frequency factor A, and their calculation formulas are as follows: Take logarithmic linearization. Its calculation formula is as follows: ln(k) at different temperatures and are used as data points for linear regression fitting to obtain the slope m and intercept b, and their calculation formulas are as follows: where k represents the deterioration rate constant, A represents the frequency factor, E a represents the activation energy, R represents the gas constant, taking 8.314 J / (mol·K), T represents the absolute temperature, m represents the slope of the linear regression fit, and b represents the intercept of the linear regression fit; (f) Using the actual ambient temperature T use Calculate the deterioration rate constant k in the actual environment use ; where k use represents the deterioration rate constant in the actual environment, and T use represents the actual environmental temperature; (g) According to the deterioration rate constant k in the actual environment use Calculate the service life t of the material in the actual environment use , and the calculation formula is as follows: where t use represents the lifespan of the material in the actual environment, unit: year; (h) According to the service life t of the material use Calculate the number of uses within the entire 50-year cycle; Among them, is the rounding function, that is, the largest integer not exceeding the real number x. T represents the total number of times the material is used during its entire life cycle of 50 years, and t use represents the lifespan of the material in the actual environment. Step 7: Calculate the carbon emission E of the prefabricated composite exterior wall made of recycled building materials during the entire life cycle use stage use ; Specifically included in Step 7 are: Step 7.1: Calculate the annual heat conduction energy consumption in winter. Refer to the outdoor and indoor design temperature values in winter provided in the "Code for Design of Heating, Ventilation and Air Conditioning of Civil Buildings" GB 50736-2012 in China, and determine it through the heat transfer amount of the exterior wall. Its calculation formula is as follows: Q cold_cond = U × A × (20 °C - (-5 °C)) × 24 × 90 ÷ 1000 Among them, Q cold_cond represents the heat conduction energy consumption of the prefabricated composite exterior wall of winter recycled building materials, U represents the heat transfer coefficient of the prefabricated composite exterior wall of recycled building materials, and A represents the area of the exterior wall; Step 7.2: Calculate the annual heat conduction energy consumption in summer. Refer to the outdoor and indoor design temperature values in summer provided in the GB 50736-2012 of the "Code for Design of Heating, Ventilation and Air Conditioning of Civil Buildings" in China, and determine it through the heat transfer amount of the exterior wall. Its calculation formula is as follows: Q hot_cond = U × A × (35 °C - 26 °C) × 24 × 90 ÷ 1000 Among them, Q hot_cond represents the heat conduction energy consumption of the prefabricated combined exterior wall of summer recycled building materials; Step 7.3: Calculate the carbon emissions during the whole life cycle usage stage of the prefabricated composite exterior wall made of recycled building materials, and its E use The calculation formula is as follows: E use = (Q cold_cond + Q hot_cond ) × 50 × T Q Among them, E use represents the carbon emissions during the whole life cycle usage stage of the prefabricated composite exterior wall of recycled building materials, and T Q represents the carbon emission coefficient; Step 8: Calculate the total carbon emissions E of the prefabricated composite exterior wall made of recycled building materials over its entire life cycle total , and optimize the objective function E total to obtain the solution for minimizing the prefabricated composite exterior wall made of recycled building materials; Specifically included in Step 8: Define the objective function. The total carbon emissions during the entire service life are expressed as the following objective function: E total = E ptc + E use Select a combined scheme for the external envelope structure of a prefabricated composite exterior wall made of recycled building materials for initialization Calculate its total carbon emissions: By an iterative method, the material selection is gradually adjusted with the aim of reducing E total , and the objective function value after each iteration is expressed as: where δ is the learning rate or step factor that controls the adjustment amplitude at each iteration, and are the partial derivatives of the carbon emissions of each part; The iterative process continues until the convergence condition is met: Where ∈ is a very small preset value. When the change in total carbon emissions is less than this value, it is considered that the optimal solution has been found; Through the above steps, find the solution that minimizes E total for the prefabricated composite exterior wall of recycled building materials The formula is as follows: Then this solution realizes the minimization of carbon emissions during the entire service life.

2. The carbon reduction optimization method for the whole life cycle of the prefabricated combined exterior wall of recycled building materials according to claim 1, characterized in that Specifically included in Step 2: Step 2.1: In the process of carbon emission reduction optimization in the whole life cycle of buildings, the carbon emissions in the production stages of different recycled building material exterior walls are crucial. E P includes the carbon emissions E P1 from the production of recycled building materials and the carbon emissions E P2 from the production of prefabricated composite exterior walls. The calculation formula is as follows: E P = E P1 + E P2 Among them, E P1 represents the carbon emissions of recycled building materials production, and E P2 represents the carbon emissions of assembled composite exterior wall production; Step 2.2: The carbon emissions of each recycled building material during the production process, and its calculation expression E P1 is as follows: E P1 = M i × C i + M j × C j + M k × C k Among them, M i , M j , M k represent the weights of the i-th type of finishing material, the j-th type of thermal insulation material, and the k-th type of structural load-bearing material of the recycled building materials. C i , C j , C k respectively represent the production carbon emission coefficients of the finishing material, thermal insulation material, and structural load-bearing material of the prefabricated composite exterior wall of the recycled building materials; Step 2.3: Carbon emission calculation expression E for prefabricated composite exterior wall P2 is as follows: E P2 = RM i,j,k × C i,j,k Among them, RM i,j,k represents the building material consumption of the prefabricated combined exterior wall of recycled building materials of type i, j, k, and C i,j,k represents the production carbon emission coefficient of the prefabricated combined exterior wall of recycled building materials of type i, j, k for the i-th finishing material.

3. The carbon reduction optimization method for the whole life cycle of the prefabricated combined exterior wall of recycled building materials according to claim 2, wherein, Specifically included in Step 3: Step 3.1: Carbon emission \(E\) during the transportation stage of the prefabricated composite exterior wall made of recycled building materials t It includes the carbon emission \(E_1\) during the transportation stage of recycled building materials t1 and the carbon emission \(E_2\) during the transportation of the prefabricated composite exterior wall t2 , and its calculation formula is: E t = E t1 + E t2 Among them, E t1 is the carbon emission during the transportation stage of recycled building materials, and E t2 is the carbon emission during the transportation of the prefabricated composite exterior wall; Step 3.2: The carbon emission calculation expression for the transportation stage of recycled building materials is: E t1 = M i × D R_i × ET + M j × D R_j × ET + M k × D R_k × ET Among them, D R_i , D R_j , D R_k respectively represent the average transportation distance of the i-th type of decorative material, the j-th type of thermal insulation material, and the k-th type of structural load-bearing material for recycled building materials. ET represents the carbon emission factor per unit weight of transportation distance; Step 3.3: The carbon emission calculation expression for the transportation of prefabricated composite exterior walls is: E t2 = M i,j,k × D C_i,j,k × ET Among them, M i,j,k represents the weight of the prefabricated combined exterior wall of i, j, k types of recycled building materials, and D C_i,j,k represents the average transportation distance of the combination scheme of the prefabricated combined exterior wall of i, j, k types of recycled building materials.

4. The carbon reduction optimization method for the whole life cycle of the prefabricated composite exterior wall of recycled building materials according to claim 3, characterized in that, Specifically included in Step 4: Step 4.1: Carbon emissions E during the construction stage of the prefabricated composite exterior wall of recycled building materials C Carbon emissions E including the energy consumption of construction machinery C1 , carbon emissions E from construction water use and drainage C2 , carbon emissions E of construction waste during the construction stage C3 , and its calculation formula is: E C = E C1 + E C2 + E C3 Step 4.2: The carbon emission calculation expression for the energy consumption of construction machinery is: where n is the total number of all construction machinery and equipment, and E C1 represents the carbon emissions from the energy consumption of construction machinery, and f(M i,j,k ) represents the impact of the exterior wall weight M i,j,k on the working efficiency of the machinery, that is, as the exterior wall weight changes, the working time required by the machinery and equipment will change accordingly. F i represents the energy consumption per unit time of the i-th type of machinery and equipment, and EF i represents the energy carbon emission factor of the i-th type of machinery and equipment; Step 4.3: The carbon emission calculation expression for construction water use and drainage is: Among them, represents the water volume used in the construction process of the i, j, k types of exterior walls, EF w represents the carbon emission factor of construction water use in the construction stage, represents the water volume of drainage in the construction process of the i, j, k types of exterior walls, EF sw represents the carbon emission factor of construction drainage in the construction stage; Step 4.4: The carbon emission calculation expression for construction waste is: Among them, m is the number of types of all construction waste, represents the waste generation amount of the i-th building material generated by the i, j, k types of exterior walls, represents the average transportation distance of the i-th building material generated by the i, j, k types of exterior walls. ET represents the carbon emission factor per unit weight of transportation distance, EF proc represents the carbon emission factor for construction waste treatment.

5. The carbon reduction optimization method for the whole life cycle of the prefabricated composite exterior wall of recycled building materials according to claim 4, wherein, Specifically included in Step 5: Step 5.1: Carbon emissions E during the demolition phase D including carbon emissions E from the energy consumption of demolition machinery D1 and carbon emissions E from the transportation of construction demolition waste D2 , and its calculation formula is: E D = E D1 + E D2 Step 5.2: The energy consumption carbon emissions of the demolition machinery depend on the energy consumed by the machinery and equipment during the demolition process, and this energy consumption is related to the weight M of the exterior wall. i,j,k It is related to D1 and its calculation formula is: where q is the total number of all demolition mechanical equipment, represents the total working time required for the i-th demolition mechanical equipment to demolish the i, j, k types of exterior walls, which is related to the weight M of the exterior wall i,j,k and F zi is related, F zi represents the unit time energy consumption of the i-th demolition mechanical equipment, and EF zi represents the energy carbon emission factor of the i-th demolition mechanical equipment; Step 5.3: The carbon emissions of transporting construction demolition waste are related to the weight M of the exterior wall, and its E i,j,k is calculated by the following expression: D2 Calculation expression is: Among them, represents the average transportation distance of the garbage generated by the i, j, and k types of exterior walls, and ET represents the carbon emission factor per unit weight of transportation distance.

6. A carbon reduction optimization system for the whole life cycle of a prefabricated composite exterior wall of recycled building materials, characterized in that, It includes: At least one processor; And at least one memory communicatively connected to the processor, where: the memory stores program instructions executable by the processor, and the processor can execute the method for optimizing carbon emission reduction during the entire service life of the prefabricated composite exterior wall of recycled building materials described in any one of claims 1-5 by calling the program instructions.

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