Carbon emission measuring and calculating method for urban bridge construction

Abstract

The invention discloses a carbon emission measuring and calculating method for urban bridge construction. The method comprises the following steps: determining a data collection range; calculating boundaries including time boundaries, land utilization and traffic delay are clearly defined; the urban bridge construction activity carbon emission E is classified; determining a carbon emission factor; calculating the carbon emission ECL of the material; calculating the transportation carbon emission EYS; and carrying out construction carbon emission ESG calculation, and determining the overall carbon emission in the urban bridge construction process. The method mainly solves the problem of incomplete coverage of carbon emission calculation in the field of urban bridge construction, helps a construction unit to comprehensively understand the contribution degree of urban bridge construction activities to carbon emission, and provides reference for evaluating the environmental influence of the urban bridge construction activities, making environmental protection policies and optimizing maintenance strategies.

Description

Technical Field

[0001] The present invention relates to the technical field of energy conservation and emission reduction in bridge engineering, and in particular to a carbon emission calculation method for urban bridge construction. Background Art

[0002] Urban bridges are usually located in the core areas of cities, with complex construction environments and diverse structural forms. However, there is a lack of carbon emission measurement methods in the process of urban bridge construction. Traditional urban bridge carbon emission measurement focuses on direct emissions during the construction phase (such as mechanical fuel consumption), lacking systematic tracking of upstream links such as material production and transportation, and indirect impacts such as land use and traffic delays, resulting in blurred boundaries of carbon accounting and one-sided data. Existing methods often rely on international general emission factor databases, fail to adapt to differences in localized construction processes and energy structures, and ignore segmented carbon sources such as the reuse of turnover materials and human activities. It is difficult to accurately reflect the true carbon footprint of China's urban construction scenes, limiting the comprehensive understanding of its environmental impact. Summary of the invention

[0003] The purpose of the present invention is to provide a carbon emission measurement method for urban bridge construction, clarify boundaries, sort out emission sources, and model in stages to accurately evaluate carbon emissions, focusing on solving the incomplete coverage of carbon emission measurement in the field of urban bridge construction, providing a scientific basis for emission reduction strategies, and promoting the bridge construction industry to develop in an environmentally friendly and sustainable direction.

[0004] The technical solution to achieve the above purpose is:

[0005] A method for calculating carbon emissions from urban bridge construction, comprising:

[0006] Step S1, determine the data collection scope, CO2 is the main emission gas;

[0007] Step S2, clearly define the measurement boundaries, including time boundaries, land use and traffic delays;

[0008] Step S3: classify the carbon emissions E from urban bridge construction activities into the carbon emissions E from the construction material production stage. CL , Carbon emissions in the transportation stage E YS and construction phase carbon emissions E SG ;

[0009] Step S4, determining the carbon emission factor;

[0010] Step S5, material carbon emissions E CL calculate;

[0011] Step S6, transportation carbon emissions E YS calculate;

[0012] Step S7, construction carbon emissions ESG Calculate and determine the overall carbon emissions during the construction of urban bridges.

[0013] Preferably, in step S2, the time boundary is direct carbon emissions, which is defined as material production, transportation and construction stages, and land use and traffic delays are indirect carbon emissions.

[0014] Preferably, the land use and the traffic delay are both caused by construction, and therefore are included in the carbon emissions during the construction phase.

[0015] Preferably, the carbon emissions E of the urban bridge construction activities exclude factors whose emissions account for less than 1% of the emission stage.

[0016] Preferably, the material carbon emissions in step S4 refer to the greenhouse gas emissions generated in the entire upstream production stage from the collection, processing and manufacturing of various building materials in bridge construction to the formation of the final product, and are calculated using the following formula:

[0017]

[0018] Where: Q i is the consumption of the i-th material, f i is the carbon emission factor of the ith material.

[0019] Preferably, the transportation carbon emissions mainly include the carbon emissions generated by the fuel or electricity consumed by the engineering machinery during the transportation stage, and are calculated using the following formula:

[0020] and f j =R j r a

[0021] Where: j = 1, 2, ···, n represents different types of transport vehicles;

[0022] N j —Number of shifts of the jth type of vehicle (shifts);

[0023] f j —Carbon emission factor of the jth vehicle (kg CO 2e / shift);

[0024] R j —Energy consumption per unit time of the jth type of vehicle (kWh or t);

[0025] a—Energy type, with values ​​of “1” for gasoline, “2” for diesel, and “3” for electricity;

[0026] r a —Carbon emission factor of the first energy source (kg CO 2e / kWh or kg CO 2e / t).

[0027] Preferably, the construction carbon emissions are calculated using the following formula:

[0028] E SG =E SGJX +E SGW +E SGP +E′ CL +E ZZ -E TD +E YW

[0029] Where: E SGJX —Carbon emissions from construction machinery (kg CO 2e );

[0030] E SGW —Carbon emissions from construction water (kg CO 2e );

[0031] E SGP —Carbon emissions generated by construction (kg CO 2e );

[0032] E' CL —Carbon emissions from construction materials (kg CO 2e );

[0033] E ZZ —Carbon emissions from turnover materials (kg CO 2e );

[0034] E TD —Carbon emissions from land use (kg CO 2e );

[0035] E YW —Carbon emissions from traffic delays (kg CO 2e ).

[0036] Preferably, the calculation formula for the construction carbon emissions includes:

[0037] 1) The calculation formula for carbon emissions generated by the construction machinery is as follows:

[0038]

[0039] f k =R k r a

[0040] Where: k = 1, 2, 3, ..., n represents different types of construction machinery, N k—The number of shifts of the kth machine (shifts), f k —Carbon emission factor of the kth machine (kg CO 2e / shift), R k —Energy consumption per unit time of the kth machine operation (kWh or t);

[0041] 2) Carbon emissions from construction water use E SGW The calculation formula is as follows:

[0042] E SGW =Q w f w

[0043] Where: Q w —Construction water consumption (t), f w —Carbon emission factor for water (kg CO 2e / t), generally 0.168;

[0044] 3) Carbon emissions generated by humans during construction E SGP The calculation formula is as follows:

[0045] E SGP =Q P f P

[0046] Where: Q P —Number of workers (persons); f P —Artificial carbon emission factor (kg CO 2e / sky).

[0047] 4) Carbon emissions from construction materials E' CL The calculation formula is as follows:

[0048]

[0049] 5) Carbon emissions from turnover materials E ZZ The calculation formula is as follows:

[0050]

[0051] Where: s=1, 2, 3, ···, n represents different types of turnover materials, Q s —Total consumption of the sth type of turnover material (pieces, tons, m 3 etc.),f s —Carbon emission factor of the sth turnover material (kg CO 2e / unit),λ s —The carbon emission conversion coefficient of the sth type of turnover material is the ratio of the usage time of the turnover material during the construction period to the usage time specified in the turnover material quota;

[0052] 6) Carbon emissions from land use E TD The calculation formula is as follows:

[0053]

[0054] Where: m is land type, with values ​​of "1" for greening, "2" for artificial lake, "3" for park, "4" for farmland, and "5" for forest. m —Area of ​​the mth land type (m 2 ),f m —Carbon emission factor for the mth land type (kg CO 2e / m 2 ·days), U—construction days (days).

[0055] 7) Carbon emissions from traffic delays E YW The calculation formula is as follows:

[0056] E YW =Q yw f a

[0057] Q yw =24UqD total v m

[0058] Where: Q yw —Total additional fuel consumption in the construction area (kg), q—Hourly traffic volume in the construction section (vehicles / h), D total —The overall average value of vehicle delays caused by construction work (h / vehicle), v—The average speed of vehicles in the construction section (km / h), F m —Fuel consumption per kilometer (kg / km).

[0059] Preferably, the turnover materials are also called "turnover materials", which refer to tool materials that can be used multiple times and basically maintain their original physical form and do not constitute engineering entities. They are usually reused, and the manufacturing carbon emissions allocated to each construction project need to be converted.

[0060] The beneficial effects of the present invention are:

[0061] The present invention analyzes in detail the main sources and influencing factors of carbon emissions in the process of urban bridge construction, identifies the key links of carbon emissions, and analyzes the influence of various factors and interactions in the sources of carbon emissions. It solves the problem that carbon emission measurement is not fully covered in the field of urban bridge construction, helps construction units to fully understand the contribution of urban bridge construction activities to carbon emissions, and provides data support for the formulation of carbon reduction strategies. In addition, by evaluating the carbon emission level of bridge construction activities, targeted carbon reduction strategies are formulated to achieve the goals of environmental protection and sustainable development, provide a basis for the selection of bridge construction plans, and provide a reference for evaluating the environmental impact of urban bridge construction activities, formulating environmental protection policies and optimizing maintenance strategies. BRIEF DESCRIPTION OF THE DRAWINGS

[0062] Figure 1 It is a flow chart of the carbon emission calculation method for urban bridge construction of the present invention;

[0063] Figure 2 It is a flow chart for classifying, determining and calculating carbon emissions E from urban bridge construction activities of the present invention. DETAILED DESCRIPTION

[0064] The present invention will be further described below in conjunction with the accompanying drawings.

[0065] See also Figure 1 The carbon emission calculation method for urban bridge construction of the present invention comprises the following steps:

[0066] Step S1, determine the data collection scope. Greenhouse gases (GHG) mainly include six gases: carbon dioxide (CO2), methane (CH4), nitrous oxide (N2O), hydrofluorocarbons (HFCs), perfluorocarbons (PFCs) and sulfur hexafluoride (SF6). CO2 gas contributes more than 90% of the total emissions in the construction process and is the main emission gas. Therefore, the "carbon emissions" mentioned in the present invention refer to CO2 emissions.

[0067] Step S2, clearly define the measurement boundary, which mainly includes three parts: time boundary, land use and traffic delay. The time boundary is direct carbon emission, and land use and traffic delay belong to indirect carbon emission.

[0068] The carbon emission calculation method based on LCA takes into account the carbon emissions during the life cycle of bridge construction activities, and defines the time boundary as the material production, transportation and construction stages. In the process of urban bridge construction, it is often accompanied by changes in land use in the original area, which may cause a reduction in the carbon sink area. The carbon emissions indirectly caused by the reduction in carbon sink capacity in this area are land use carbon emissions. During the construction of the road, the closure of the lanes will cause vehicles to accelerate, decelerate, queue, and congestion. The additional carbon emissions caused by this phenomenon are traffic delay carbon emissions. Because traffic delays and land use are both caused by construction, they are included in the carbon emissions of the construction phase together with construction machinery, construction materials, turnover materials, construction water and labor.

[0069] Step S3, see Figure 2 , the carbon emissions from urban bridge construction activities are classified into the carbon emissions from the construction material production stage E CL , Carbon emissions in the transportation stage E YS and construction phase carbon emissions E SG Three parts. To improve the efficiency of analysis, exclude factors whose emissions account for less than 1% of the emission stage, optimize resource allocation, avoid unnecessary calculations, and improve analysis efficiency. For example, when the carbon emissions from traffic delays account for less than 1% of the carbon emissions in the on-site construction stage, exclude the impact of this factor on the carbon emissions of urban bridge construction, and no further analysis will be performed. Otherwise, output its carbon emissions.

[0070] Step S4, carbon emission factor determination, determine the carbon emission factors of materials, energy, vehicles and machinery, and land use in the construction process of urban bridges. Carbon emission factors can be queried through the Boustead database, Ecoinvent database, ELCD database, and the localized life cycle basic database (Chinese Life Cycle Database, CLCD) constructed by Sichuan University to increase the accuracy and applicability of the data.

[0071] Step S5, material carbon emissions E CL Calculation, material production refers to the production of various building materials used in bridge construction activities, such as steel, cement, concrete, etc., and the assembly of prefabricated components in the factory. Material production carbon emissions refer to the greenhouse gas emissions generated by the entire upstream production stage from raw material collection, processing and manufacturing to the formation of the final product. These emissions mainly come from the production process of materials, such as energy consumption, chemical reactions, material transportation and other links. The specific calculation formula is as follows:

[0072]

[0073] Where: i = 1, 2, ..., n, representing different material types respectively;

[0074] Qi is the consumption of the i-th material (pieces, t, m 3 wait);

[0075] f i is the carbon emission factor of the i-th material (kg CO 2e / unit).

[0076] Step S6, transportation carbon emissions E YS Calculation: Vehicle transportation includes construction equipment and material transportation. Carbon emissions mainly include carbon emissions generated by fuel or electricity consumption of construction machinery during the transportation phase. The main source of carbon emissions is the energy consumption of vehicles used by transportation equipment. The calculation formula is as follows:

[0077] and f j =R j r a

[0078] Where: j = 1, 2, ···, n represents different types of transport vehicles;

[0079] N j —Number of shifts of the jth type of vehicle (shifts);

[0080] f j —Carbon emission factor of the jth vehicle (kg CO 2e / shift);

[0081] R j —Energy consumption per unit time of the jth type of vehicle (kWh or t);

[0082] a—Energy type, with values ​​of “1” for gasoline, “2” for diesel, and “3” for electricity;

[0083] r a —Carbon emission factor of the first energy source (kg CO 2e / kWh or kg CO 2e / t).

[0084] Step S7, construction carbon emissions E SG Calculation, on-site construction includes all kinds of construction processes carried out inside the construction site. Carbon emissions mainly come from carbon emissions generated by energy consumption of machinery on site, carbon emissions generated by construction water, carbon emissions generated by on-site construction personnel, carbon emissions from construction materials, carbon emissions from turnover materials, carbon emissions from land use, and carbon emissions from traffic delays. The calculation formula is as follows:

[0085] E SG =E SGJX +E SGW +E SGP +E′ CL +EZZ -E TD +E YW

[0086] Where: E SGJX —Carbon emissions from construction machinery (kg CO 2e );

[0087] E SGW —Carbon emissions from construction water (kg CO 2e );

[0088] E SGP —Carbon emissions generated by construction (kg CO 2e );

[0089] E' CL —Carbon emissions from construction materials (kg CO 2e );

[0090] E ZZ —Carbon emissions from turnover materials (kg CO 2e );

[0091] E TD —Carbon emissions from land use (kg CO 2e );

[0092] E YW —Carbon emissions from traffic delays (kg CO 2e ).

[0093] Wherein: 1) The calculation formula of carbon emissions generated by the construction machinery is as follows:

[0094]

[0095] f k =R k r a

[0096] Where: k = 1, 2, 3, ···, n represents different types of construction machinery;

[0097] N k —The number of shifts of the kth machine (shifts);

[0098] f k —Carbon emission factor of the kth machine (kg CO 2e / shift);

[0099] R k —Energy consumption per unit time of the kth machine operation (kWh or t);

[0100] 2) Carbon emissions from construction water use E SGW The calculation formula is as follows:

[0101] E SGW =Q w f w

[0102] Where: Q w —Construction water consumption (t);

[0103] f w —Carbon emission factor for water (kg CO 2e / t), generally 0.168;

[0104] 3) Carbon emissions generated by humans during construction E SGP The calculation formula is as follows:

[0105] E SGP =Q P f P

[0106] Where: Q P —Number of workers (persons);

[0107] f P —Artificial carbon emission factor (kg CO 2e / sky).

[0108] 4) Construction materials are consumable materials used in the construction process, such as welding materials, iron parts, etc. Carbon emissions generated by construction materials E' CL The calculation formula is as follows:

[0109]

[0110] 5) Turnover materials are also called "turnover materials". During the construction process of building installation projects, tool materials that can be used multiple times and basically maintain their original physical form and do not constitute engineering entities, such as steel-wood composite model boards, steel pipe scaffolding, etc. Turnover materials are usually reused in different projects, so the manufacturing carbon emissions allocated to each construction project need to be converted. Carbon emissions generated by turnover materials E ZZ The calculation formula is as follows:

[0111]

[0112] Wherein: s=1, 2, 3, ···, n represents different types of turnover materials;

[0113] Q s —Total consumption of the sth type of turnover material (pieces, tons, m 3 wait);

[0114] fs —Carbon emission factor of the sth turnover material (kg CO 2e / unit);

[0115] λ s —The carbon emission conversion coefficient of the sth type of turnover material is the ratio of the usage time of the turnover material during the construction period to the usage time specified in the turnover material quota.

[0116] 6) Carbon emissions from land use E TD The calculation formula is as follows:

[0117]

[0118] Where: m is land type, with values ​​of "1" for greening, "2" for artificial lake, "3" for park, "4" for farmland, and "5" for forest;

[0119] A m —Area of ​​the mth land type (m 2 );

[0120] f m —Carbon emission factor for the mth land type (kg CO 2e / m 2 ·sky);

[0121] U—Construction days (days).

[0122] 7) Carbon emissions from traffic delays E YW The calculation formula is as follows:

[0123] E YW =Q yw f a

[0124] Q yw =24UqD total v m

[0125] Where: Q yw —Total amount of additional fuel consumption in the construction area (kg);

[0126] q—hourly traffic volume in the construction section (vehicles / h);

[0127] D total —The overall average value of vehicle delays caused by construction work (h / vehicle);

[0128] v—average vehicle speed in the construction section (km / h);

[0129] F m —Fuel consumption per kilometer (kg / km).

[0130] In summary, the present invention constructs a full life cycle (LCA) analysis framework for the three stages of covering material production, transportation and construction, and innovatively incorporates indirect carbon sources such as land use carbon sink loss and traffic delay emissions to form a systematic measurement system; a hierarchical screening mechanism is used to filter out secondary factors, design dynamic calculation formulas and localized database adaptation, while ensuring scientific accuracy while improving the operability of the project, and through engineering parameters such as the number of shifts and energy consumption time, it achieves seamless connection with construction management, which can not only accurately quantify high-carbon links such as steel production, but also support low-carbon decisions such as green building materials selection and construction organization optimization, providing a technical path with both theoretical innovation and practical value for the refined control of carbon footprint in the infrastructure field.

[0131] The above embodiments are only used to illustrate the present invention, rather than to limit the present invention. Those skilled in the relevant technical field may make various changes or modifications without departing from the spirit and scope of the present invention. Therefore, all equivalent technical solutions should also belong to the scope of the present invention and should be defined by the claims.

Claims

1. A method for calculating carbon emissions from urban bridge construction, characterized in that: include: Step S1, determine the data collection scope, CO2 is the main emission gas; Step S2, clearly define the measurement boundaries, including time boundaries, land use and traffic delays; Step S3: Classification of carbon emissions E from urban bridge construction, divided into carbon emissions E from the construction material production stage. CL , Carbon emissions in the transportation stage E YS and construction phase carbon emissions E SG ; Step S4, determining the carbon emission factor; Step S5, material carbon emissions E CL calculate; Step S6, transportation carbon emissions E YS calculate; Step S7, construction carbon emissions E SG Calculate and determine the overall carbon emissions during the construction of urban bridges.

2. The carbon emission calculation method for urban bridge construction according to claim 1 is characterized in that: In step S2, the time boundary is direct carbon emissions, which is defined as the material production, transportation and construction stages, and the land use and traffic delays are indirect carbon emissions.

3. The carbon emission calculation method for urban bridge construction according to claim 2 is characterized in that: The land use and traffic delays are both caused by construction and are therefore included in the carbon emissions during the construction phase.

4. The carbon emission calculation method for urban bridge construction according to claim 1 is characterized in that: The carbon emissions E from urban bridge construction need to exclude factors whose emissions account for less than 1% of the emission stage.

5. The carbon emission calculation method for urban bridge construction according to claim 1 is characterized in that: The material carbon emissions in step S4 refer to the greenhouse gas emissions generated in the entire upstream production stage from the collection, processing and manufacturing of various building materials in bridge construction to the formation of the final product, and are calculated using the following formula: Where: Q i is the consumption of the i-th material, f i is the carbon emission factor of the ith material.

6. The carbon emission calculation method for urban bridge construction according to claim 1 is characterized in that: The transportation carbon emissions mainly include the carbon emissions generated by the fuel or electricity consumed by the construction machinery during the transportation phase, and are calculated using the following formula: and f j =R j r a Where: j = 1, 2, ···, n represents different types of transport vehicles; N j —Number of shifts of the jth type of vehicle; f j —Carbon emission factor of the jth vehicle; R j —Energy consumption per unit time of the jth type of vehicle; a—Energy type, with values ​​of "1" for gasoline, "2" for diesel, and "3" for electricity; r a —Carbon emission factor of the first energy source.

7. The carbon emission calculation method for urban bridge construction according to claim 1 is characterized in that: The construction carbon emissions are calculated using the following formula: AND SG =And SGJX +E SGW +E SGP +E′ CL +E ZZ -AND TD +E YW Where: E SGJX —Carbon emissions from construction machinery; E SGW —Carbon emissions from construction water use; E SGP —Carbon emissions generated artificially during construction; E' CL —Carbon emissions from construction materials; E ZZ —Carbon emissions from turnover materials; E TD —Carbon emissions from land use; E YW —Carbon emissions from traffic delays.

8. The carbon emission calculation method for urban bridge construction according to claim 7 is characterized in that: The calculation formula for construction carbon emissions includes: 1) The calculation formula for carbon emissions generated by the construction machinery is as follows: f k =R k r a Where: k = 1, 2, 3, ..., n represents different types of construction machinery, N k —The number of shifts of the kth machine, f k —Carbon emission factor of the kth machine, R k —Energy consumption per unit time of the kth type of machinery; 2) Carbon emissions from construction water use E SGW The calculation formula is as follows: E SGW =Q w f w Where: Q w —Construction water consumption (t), f w —Carbon emission factor for water, take 0.168; 3) Carbon emissions generated by humans during construction E SGP The calculation formula is as follows: E SGP =Q P f P Where: Q P —artificial number, f P —Artificial carbon emission factors; 4) Carbon emissions from construction materials E' CL The calculation formula is as follows: 5) Carbon emissions from turnover materials E ZZ The calculation formula is as follows: Where: s=1, 2, 3, ···, n represents different types of turnover materials, Q s —Total consumption of the sth type of turnover material, f s —Carbon emission factor of the sth turnover material, λ s —The carbon emission conversion coefficient of the sth type of turnover material is the ratio of the usage time of the turnover material during the construction period to the usage time specified in the turnover material quota; 6) Carbon emissions from land use E TD The calculation formula is as follows: Where: m is land type, with values ​​of "1" for greening, "2" for artificial lake, "3" for park, "4" for farmland, "5" for forest, m —the area of ​​the mth land type, f m —Carbon emission factor for the mth land type, U—construction days; 7) Carbon emissions from traffic delays E YW The calculation formula is as follows: E YW =Q yw f a Q yw =24UqD total vF m Where: Q yw —Total additional fuel consumption in the construction area, q —Hourly traffic volume in the construction area, Dt o ta l —The overall average of vehicle delays caused by construction work, v—The average speed of vehicles in the construction section, F m —Fuel consumption per kilometer.

9. The carbon emission calculation method for urban bridge construction according to claim 8 is characterized in that: The turnover materials, also known as "turnover materials", refer to tool materials that can be used multiple times and basically maintain their original physical form and do not constitute engineering entities. They will be reused, and the manufacturing carbon emissions allocated to each construction project need to be converted.

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