Disclosure of Invention
The invention provides a method for predicting carbon emission in a railway route selection design stage aiming at a route scheme generated in the railway route selection design process and according to the characteristics of a construction stage, an operation management stage and a maintenance stage of a railway full life cycle, and the specific technical scheme is as follows:
a method for predicting carbon emission in a railway route selection design stage specifically comprises the following steps:
s1: predicting the carbon emission generated in the railway full-line construction stage, specifically comprising the following steps:
s1-1: respectively predicting the carbon emission of the railway full-line bridge, the tunnel, the roadbed and the track according to the carbon emission generated by the production of building materials and the operation of construction equipment in the construction process;
s1-2: predicting the carbon emission of the whole railway land acquisition according to the land acquisition area of the railway subgrade and the land acquisition area of the railway bridge;
s2: predicting the carbon emission generated by a railway line traction power supply system in an operation management stage;
s3: predicting the carbon emission generated in the railway maintenance stage;
s4: and summing the carbon emission results predicted in the steps S1-S3 to obtain the total carbon emission amount in the railway route selection design stage, wherein the expression is as follows:
E total =E const +E opera +E maint ;
wherein E total Total carbon emission for the railway route selection design phase; e const The total carbon emission in the construction stage of railway line selection construction; e opera The total carbon emission in the railway line selection operation management stage is calculated; e maint The total carbon emission in the railway maintenance and repair stage.
Preferably, step S1 further includes, before: designing a bridge submodel, a tunnel submodel, a roadbed submodel and a track submodel according to railway route selection to form a carbon emission prediction model for a railway full-route construction stage; the step S1 is specifically: respectively carrying out carbon emission prediction generated in the railway full-line construction stage on the bridge submodel, the tunnel submodel, the roadbed submodel and the track submodel, wherein the expressions are as follows:
E const =E bri +E tun +E sub +E tra +E req ;
wherein E is req The carbon sink quantity of vegetation lost due to land occupation; e bri The carbon emission of the railway full bridge; e tun Carbon emission of the railway full-track tunnel; e sub The carbon emission of the railway full-line roadbed; e tra Is the carbon emission of the full-line orbit.
Preferably, step S1-2 in step S1 is specifically: according to the carbon emission prediction model, the carbon sink loss of the vegetation is predicted according to the area loss of different types of vegetation caused by land occupation, the carbon sink loss of the vegetation is equal to the carbon emission caused by railway land acquisition, and the expression is as follows:
wherein, c
m For the annual carbon sink per unit area of the m-th vegetation, m =1,2,3, and 1 represents a forest land, 2 represents a grassland, and 3 represents a cultivated land; t is the service life of the railway;
various vegetation loss areas caused by land acquisition of bridges; />
The area of various vegetations lost for the land acquisition of the railway subgrade.
Preferably, in the step S1, the carbon emission of the railway full-track bridge is predicted according to the bridge sub-model, and the expression is as follows:
wherein, g
conc Is a concrete carbon emission factor; g
rebar Is a carbon emission factor of the steel bar;
the concrete consumption of the ith bridge is used; />
The steel bar consumption of the ith bridge seat is used; n is a radical of
bridge The total number of the bridges; />
Carbon emission generated by the operation of construction equipment required for bridge construction.
Preferably, in the step S1, the carbon emission of the railway full-track tunnel is predicted according to the tunnel sub-model, and the expression is as follows:
wherein,
the concrete consumption required for lining the ith' seat tunnel; n is a radical of
tunnel The total number of the tunnels is; />
Carbon emissions from the operation of construction equipment required to construct tunnels.
Preferably, in the step S1, the carbon emission of the railway full-track roadbed is predicted according to the roadbed sub-model, and the expression is as follows:
wherein,
average carbon emissions for each linear meter of earthen material; />
Average carbon emission of equipment required for constructing roadbed of every linear meter; l is
sub The length of the railway full line roadbed.
Preferably, in the step S1, the carbon emission of the whole railway track is predicted according to the track sub-model, and the expression is as follows:
wherein, g
steel Is a steel carbon emission factor;
the concrete consumption of the track slab and the base; />
The steel consumption for laying the steel rail; />
Carbon emissions from the operation of the construction equipment required to construct the track.
Preferably, the step S2 is specifically: carrying out a railway traction operation simulation experiment according to the carbon emission prediction model, collecting simulation data, and predicting the carbon emission generated by a railway line traction power supply system in an operation management stage according to the simulation data, wherein the expression is as follows:
wherein n is the number of line division sections;
is the first->
Total energy consumption per sector; g
e Is a power emission factor; eta
e Electromechanical efficiency; n is the maximum passing capacity of the train; d is the annual operating days of the station; />
The service life of the railway is prolonged.
Preferably, the step S3 specifically includes: predicting the carbon emission generated by a roadbed and a track maintenance stage in the railway according to a carbon emission prediction model, wherein the expression of the carbon emission is as follows:
wherein,
carbon emission is maintained for the maintenance of the railway full-line foundation section; />
The carbon emission is maintained for the maintenance of the railway whole line base section.
The technical scheme of the invention has the following beneficial effects:
(1) The invention aims at a railway line scheme generated in a railway route selection design stage, establishes a quantitative prediction model of carbon emission in construction, operation, management and maintenance stages according to the characteristics of the carbon emission in the whole life cycle of a railway, provides a carbon emission prediction method in the railway route selection design stage, makes up the defect of quantitatively evaluating the carbon emission content in the whole life cycle of the railway in the railway route selection design stage, and promotes the development of a green low-carbon route selection technology of the railway.
(2) In the construction and construction stage, aiming at bridges, tunnels, roadbeds and tracks, a quantitative prediction model of carbon emission generated in the corresponding building material production and construction process is constructed according to engineering experience; a railway full-line vegetation carbon sink prediction model is established based on vegetation loss conditions of forest lands, grasslands and cultivated lands caused by subgrades and bridge land acquisition along a railway.
(3) In the invention, a carbon emission prediction model of the railway line electric traction system is provided in the operation management stage.
(4) In the maintenance and repair stage, the invention develops a method for predicting the carbon emission of the maintenance and repair of the full-line roadbed structure and the replacement of the track according to the life cycle of the structure and the engineering experience.
In addition to the above-described objects, features and advantages, the present invention has other objects, features and advantages. The present invention will be described in further detail below with reference to the drawings.
Detailed Description
Embodiments of the invention will be described in detail below with reference to the drawings, but the invention can be implemented in many different ways, which are defined and covered by the claims.
Example 1:
referring to fig. 1, a method for predicting carbon emission in a railway route selection design stage specifically includes:
designing a bridge submodel, a tunnel submodel, a roadbed submodel and a track submodel according to railway route selection, and forming a carbon emission prediction model for a railway full-route construction stage, referring to fig. 2;
s1: predicting the carbon emission generated in the railway full-line construction stage, specifically comprising the following steps:
respectively carrying out carbon emission prediction on the bridge submodel, the tunnel submodel, the roadbed submodel and the track submodel, wherein the expressions are as follows:
E const =E bri +E tun +E sub +E tra +E req 1);
wherein E is req The carbon sink quantity of vegetation lost due to land occupation; e bri For the railwayCarbon emission of the full-line bridge; e tun The carbon emission of the railway full-track tunnel is shown; e sub Carbon emission of the railway full-line roadbed; e tra Carbon emissions for full-line orbitals; e const The total carbon emission in the construction stage of railway line selection construction is obtained.
S1-1: respectively predicting the carbon emission of the railway full-line bridge, the tunnel, the roadbed and the track according to the carbon emission generated by the production of building materials and the operation of construction equipment in the construction process; the method comprises the following steps:
predicting the carbon emission of the railway full-line bridge according to the bridge submodel, wherein the expression is as follows:
wherein, g
conc Is a concrete carbon emission factor; g
rebar Is a carbon emission factor of the steel bar;
the concrete consumption of the ith bridge is used; />
The steel bar consumption of the ith bridge seat is used; n is a radical of
bridge The total number of the bridges; />
Carbon emission generated by the operation of construction equipment required for bridge construction.
Forecasting concrete consumption of ith bridge
The expression is as follows:
wherein,
the concrete consumption of the bridge span structure of the ith bridge is measured; />
The concrete consumption of the i-th bridge pier is determined.
Concrete consumption of i-th bridge span structure
The expression is as follows:
wherein S is
bs The cross-sectional area of the bridge span structure;
the length of the ith bridge; />
The concrete unit weight of the bridge span structure is shown. />
Concrete consumption of i-th bridge pier
The expression is as follows:
wherein,
the number of the piers of the ith bridge; />
The height of the nth' pier of the ith bridge; />
For the unit weight of the bridge pier concrete;S
bp The bottom area of the bridge pier is shown; l is the bridge span.
Predicting the steel bar consumption of the ith bridge
The expression is as follows:
wherein,
using the steel bars for the bridge span structure of the ith bridge; />
The steel bar consumption is the steel bar consumption of the i-th bridge pier.
Predicting the using amount of structural steel bars of the i-th bridge span
The expression is as follows:
wherein, C
bs The perimeter of the cross section of the bridge span structure; b
bs Is the cross-sectional width; s is the stirrup spacing;
the reinforcement ratio of the bridge span is obtained;
the bridge span coupling ratio; />
The volume weight of the bridge span longitudinal bar is; />
The volume weight of the bridge span stirrup is shown.
Predicting the reinforcing steel bar consumption of the i-th bridge pier
The expression is as follows:
wherein, C
bp Is the perimeter of the pier cross section, b
bp In the case of the cross-sectional width,
reinforcing steel bar ratio for the bridge pier; />
The hoop ratio of the bridge pier is determined; />
The volume weight of the longitudinal ribs of the bridge pier is measured; />
The volume weight of the stirrup of the pier is measured.
Prediction of carbon emissions from the operation of construction equipment required to build bridges
The expression is as follows:
wherein,
the average carbon emission of equipment is built for building each linear meter of bridge.
And further obtaining the carbon emission generated by constructing the railway full-line bridge, wherein the expression is as follows:
predicting the carbon emission of the railway full-track tunnel according to the tunnel sub-model, wherein the expression is as follows:
wherein,
the concrete consumption required for lining the ith' seat tunnel; n is a radical of
tunnel The total number of the tunnels is; />
Carbon emissions from the operation of construction equipment required to construct tunnels.
Forecasting concrete consumption needed by ith' seat tunnel lining
The expression is as follows:
wherein,
the length of the tunnel of the ith' seat; r is the radius of a tunnel excavation cave; d
1 The initial spray layer concrete thickness; d
2 The thickness of the secondary lining concrete; rho
c1 The volume weight of the initial sprayed layer concrete is adopted; rho
c2 The volume weight of secondary lining concrete is adopted; and pi is the circumferential ratio.
Predicting the carbon emission generated by the operation of construction equipment required for constructing the tunnel, wherein the expression is as follows:
wherein,
the average carbon emission of the equipment is built for building each linear meter of tunnel.
And further obtaining the carbon emission generated by constructing the railway full-track tunnel, wherein the expression is as follows:
and predicting the carbon emission of the railway full-track roadbed according to the roadbed sub-model, wherein the expression is as follows:
wherein,
average carbon emissions for each linear meter of earthen material; />
Average carbon emission of equipment required for constructing roadbed of every linear meter; l is
sub The length of the railway full-line roadbed.
Predicting the carbon emission of the whole railway track according to the track sub-model, wherein the expression is as follows:
wherein, g
steel Is a steel carbon emission factor;
the concrete consumption of the track slab and the base; />
The steel consumption for laying the steel rail; />
Carbon emissions from the operation of the construction equipment required to construct the track.
Predicting concrete usage of track slabs and foundations
The expression is as follows: />
Wherein S is tra Is a cross-sectional area; l is tra Is the track length; rho conc Is the volume weight of concrete.
Predicting steel consumption for laying rail
The expression is as follows:
where ρ is steel Is of the rail type.
The carbon emission generated by the operation of construction equipment required by the construction of the track is expressed as follows:
wherein,
average carbon emissions of construction equipment used to construct each linear meter of track.
And further obtaining the carbon emission generated by constructing the whole railway track, wherein the expression is as follows:
s1-2: predicting the carbon emission of the whole railway land acquisition according to the land acquisition area of the railway subgrade and the land acquisition area of the railway bridge; the method comprises the following steps:
according to the carbon emission prediction model, the carbon sink loss of the vegetation is predicted according to the loss areas of different types of vegetation caused by land occupation, the carbon sink loss of the vegetation is equal to the carbon emission caused by railway land acquisition, and the expression is as follows:
wherein, c
m The annual carbon sink per unit area of the mth type vegetation, m =1,2,3, and 1 represents a forest land, 2 represents a grassland, and 3 represents a cultivated land; t is the service life of the railway;
various vegetation loss areas caused by land acquisition of bridges; />
The area of various vegetations lost caused by land acquisition of the railway subgrade.
The land occupied by the carbon emission prediction model is divided into a railway subgrade land acquisition area and a railway bridge land acquisition area;
predicting various vegetation loss according to the land acquisition area of the railway subgrade, wherein the expression is as follows;
wherein N is m The number of the cross sections occupying the m-th green land; k k The kth section mileage; w k The width of the ground of the k section.
Predicting various vegetation loss according to the land acquisition area of the railway bridge, wherein the expression is as follows:
wherein,
spanning the length of the mth type of greenfield for the bridge; l is the bridge span; s
bp Is the bottom area of the pier.
S2: predicting the carbon emission generated by a railway line traction power supply system in an operation management stage, and referring to fig. 3; the method comprises the following steps:
carrying out a railway traction operation simulation experiment according to the carbon emission prediction model, collecting simulation data, and predicting the carbon emission generated by a railway line traction power supply system in an operation management stage according to the simulation data, wherein the expression is as follows:
wherein n is the number of line division sections;
is a first->
Total energy consumption per sector; g
e Is a power emission factor; eta
e Electromechanical efficiency; n is the maximum passing capacity of the train; d is the annual operation days of the station; />
The service life of the railway; e
opera And (4) the total carbon emission in the railway line selection operation management stage.
The carbon emission generated in the railway operation management stage is mainly generated by a train electric traction power supply system and can be obtained by calculating train operation energy consumption and corresponding electric carbon emission factors; the energy consumption of the train in unit distance operation is mainly related to the resistance of the train, including basic resistance W 0 And is attached withAdded resistance W j 。
W(v)=W 0 +W j 2-2);
The basic resistance is independent of the route scheme and is mainly influenced by the running speed of the train, and the unit basic resistance calculation formula is as follows:
w 0 =a+bv+cv 2 2-3);
wherein v is the train running speed, a, b and c are test constants, and a is mainly influenced by resistance related to the train weight and comprises the friction resistance between a journal and a bearing and the rolling friction resistance between a wheel and a steel rail; b is mainly influenced by the sliding friction resistance of the wheels on the steel rails, the irregularity of the rails, the impact and the vibration resistance caused by the abrasion of the wheel treads and the like; c is mainly affected by the space resistance.
The additional resistance is closely related to the line scheme and mainly comprises the additional resistance W of the ramp i Curve additional resistance W r And additional resistance W of tunnel air s The calculation formula of each corresponding unit additional resistance is as follows:
wherein,
the slope value is (‰), and the upward slope is positive; r is the radius of the curve; l is
s The total length of the tunnel.
Therefore, the calculation formula of the running resistance of the high-speed train is as follows:
wherein M is the mass of the train; g is gravity acceleration;
the application also applies an efficient train operation speed curve optimization method, can obtain an optimized operation speed curve which enables the train operation energy consumption and the time cost to be comprehensively minimum, and accurately calculates the train operation energy consumption and the time cost under the speed curve, and the specific steps are as follows:
the first step is as follows: carrying out railway traction operation simulation to obtain curve data of v-s (speed and distance) and t-s (time and distance) of the train;
the second step: calculating the line addition gradient and dividing the line into sections;
calculating the added gradient according to the additional resistance of the unit ramp, and regarding the line as a straight line without tunnel, i.e. regarding the curve additional resistance and the tunnel additional resistance as the gradient i r And i s The resistance generated being
Wherein i r Calculating the slope for the additional resistance; i.e. i s And adding resistance to the tunnel and converting the slope.
Plus gradient i j The sum of the slope on the longitudinal section of the line, the curve on the slope and the conversion slope of the additional resistance of the tunnel is shown as follows:
i j =i+i r +i s =i+2000/R+0.00013L s 2-7);
in order to ensure that the train stops at the line terminal position accurately, the position of a train stopping brake point needs to be calculated; suppose that the train adopts the maximum braking acceleration a in the braking stage max Braking, calculating the train parking brake point position by:
wherein v is bra The braking speed is the running speed of the train during braking, namely the running speed of the train is controlled to be the speed of the position of a constant torque and constant power conversion point in the traction characteristic curve of the train; l is bra Maximum braking acceleration a for train max By v bra The travel distance required to drop to 0; l is the line length; s bra Is the parking brake point position.
Then, dividing the line according to the added gradient and the position of the parking brake point, wherein each slope section with the same added gradient before the parking brake point is a sub-section, and the last slope section after the parking brake point (including the slope section where the parking brake point is located) is a sub-section, as shown in fig. 4;
solving the target speed of each subsection:
when the train runs at a constant speed on a constant addition gradient, the running energy consumption of the train is related to the running resistance, and the running resistance and the running distance of the train can be calculated, so that the running energy consumption E (v) of the train on a unit distance railway line (such as 1 km) has the following calculation formula:
furthermore, the train operation energy consumption cost can be determined by unit train energy consumption and unit energy consumption cost c energy And calculating according to the following formula:
C energy (v)=E(v)·c energy 2-10);
under the condition of uniform speed operation, the time T required by the train to operate for a unit distance can be calculated by the operation speed, and the formula is as follows:
T=1/v 2-11);
further, the passenger time fee may be composed of a unit operation time and a unit time fee c time The formula is as follows:
C time (v)=T·c time 2-12);
the relational expression of train operation energy consumption and time cost and operation speed of a unit distance railway line (such as 1 km) can be obtained, the higher the speed is, the higher the train operation energy consumption cost is, the lower the passenger time cost is, and the expression is as follows:
wherein v is the train running speed; a, b and c are experimental constants; c. C energy Is the cost of unit energy consumption; c. C time Is a unit time cost.
Calculating the derivative of v to obtain the running speed v for minimizing the energy consumption and time cost of train running opt Referring to fig. 5, the expression is as follows:
besides the optimal speed, the target speed of each subsection is also constrained by the line balance speed and the limiting speed; thus, the target speed v of each subsection tar For an optimum speed v opt Equalizing velocity v ava And a limit speed v lim The minimum value of the three is expressed as follows:
speed limit v lim The highest speed allowed by the operation safety of the train on the downhill section is ensured, and the speed v is balanced ava Mainly influenced by locomotive traction power and train running resistance; when the resultant force exerted on the train is 0 (i.e. the traction force is the same as the running resistance), the corresponding train running speed is the equilibrium speed.
Guiding the train to run in a traction manner according to the target speed of each subsection to obtain an optimized train running speed curve;
the train operation modes comprise acceleration operation, constant speed operation, inert force operation and braking operation, and the train enters each subsection according to the current operation speed of the train
And a target speed of each sub-section>
The operation mode is automatically switched, and the operation mode is specifically as follows:
i. when in use
When in use, the train firstly runs in an accelerating way,when the subsection target speed is reached>
Then, the operation is changed into the constant speed operation until the subsection is finished;
ii when
Then, the train runs at a constant speed until the subsection is finished;
iii when
When the train runs with inertia, the target speed of the subsection is reached>
Then, the operation is converted into constant speed operation until the sub-section is finished;
and iv, when the train reaches a parking braking point or the running speed reaches a limit speed and the running resistance of the train is the same as the running direction, adopting braking operation.
Calculating train operation energy consumption based on train v-s and t-s simulation data;
calculating the work done by the traction force of a section when the train runs;
in different operating modes, there is a significant difference in energy consumption and time required for a train to travel the same distance.
Under the acceleration mode, the magnitude of the traction acceleration of the train can be calculated through resultant force applied to the train, and in order to ensure the comfort level and the driving safety of passengers, the traction acceleration does not exceed 0.2g, and the calculation formula is as follows:
wherein, a ava (v) The acceleration when the running speed of the train is v is taken as the reference; f (v) is the traction force when the train running speed is v, and W (v) is the running resistance when the train running speed is v.
The train operation speed is eachIncrease energy consumption E required by 1m/s tra (v) The expression is as follows:
when the running speed reaches the target speed, the running mode is switched to the constant speed running mode, and the train running energy consumption E is realized in the mode cru (v) Depending on the train running resistance and the running distance, the expression is as follows:
E cru (v)=W(v)×L cru 2-18);
and when the running speed of the train is higher than the target speed, the train runs by adopting inertia force. In the inertia force operation mode, the train is only under the action of operation resistance, and the traction force is 0; therefore, the train operation energy consumption in the coasting operation mode is 0.
When the running speed of the train exceeds the limit speed and the running resistance direction of the train is the same as the running direction of the train, a braking running mode is required; the braking force is used for overcoming the train resistance and maintaining the train speed limit until the section is finished; when the braking operation mode is adopted, the train stores energy through the regeneration device, namely, no energy consumption is generated.
Based on the formula, the train operation energy consumption in different operation modes can be obtained. The energy consumption of the train running once along the line in the single direction can be obtained by carrying out the train running simulation under the given speed interval (adopting 1 m/s).
And finally, carbon emission generated by traction power supply of all trains on the line for one year is obtained, and further carbon emission generated by a railway line traction power supply system in the operation management stage is obtained.
S3: predicting the carbon emission generated in the railway maintenance and repair stage, and referring to fig. 6; the method comprises the following steps:
predicting the carbon emission generated by a roadbed and a track maintenance stage in the railway according to a carbon emission prediction model, wherein the expression of the carbon emission is as follows:
wherein,
maintaining and repairing carbon emission for the railway whole line base section; />
Replacing the carbon emission for the whole railway track; e
maint The total carbon emission in the railway maintenance and repair stage.
The maintenance and repair of the roadbed section mainly comprises the steps of reinforcing a slope protection structure once every 50 years, namely reinforcing and repairing twice within the service life of a railway; according to the Jinghu high-speed rail engineering data, the carbon emission amount for maintaining and maintaining roadbed per linear meter can be determined
And further calculating the carbon emission of maintenance and repair of the railway full-line base section, wherein the expression is as follows:
wherein,
carbon emissions generated by daily maintenance of the roadbed per linear meter; l is
sub Is the length of the roadbed.
Secondly, as the steel rail is broken, cracked and other damages which influence the steel rail and limit the service performance of the steel rail can occur in the using process, the rail needs to be replaced regularly within the service life of the railway in order to consider the driving safety;
calculating the number of times that the track needs to be replaced within the service life of the railway according to the life cycle of the track, wherein the expression is as follows:
N replace =T/T tra -1 3-3);
wherein, N replace The number of times of track replacement; t is a unit of tra Is the life cycle age of the track.
When the track is replaced, the wear rate of the steel rail in the transportation and construction processes is considered, the carbon discharge amount of the whole track of the railway is calculated, and the calculation formula is as follows:
wherein,
the amount of the laid steel rails is used; w is the wear rate of the steel rail; g
steel Is the carbon emission factor of steel.
And further obtaining the carbon emission generated in the maintenance and repair stage of the roadbed and the track in the railway, wherein the expression is as follows:
s4: summing the predicted carbon emission results of the steps S1-S3 to obtain the total carbon emission amount of the railway route selection design stage, wherein the expression is as follows:
E total =E const +E opera +E maint 4);
wherein, E total The total carbon emission in the design stage of railway line selection.
The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention, and various modifications and changes may be made by those skilled in the art. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.