CN114037292A

CN114037292A - Low-carbon optimized scheduling method of electricity-gas integrated energy system considering carbon capture

Info

Publication number: CN114037292A
Application number: CN202111335666.9A
Authority: CN
Inventors: 余莎; 何光层; 李新洪; 彭文英; 聂剑锋; 叶志祥; 李树东; 杨竣皓
Original assignee: Baoshan Power Supply Bureau of Yunnan Power Grid Co Ltd
Current assignee: Baoshan Power Supply Bureau of Yunnan Power Grid Co Ltd
Priority date: 2021-11-11
Filing date: 2021-11-11
Publication date: 2022-02-11

Abstract

The invention relates to a low-carbon optimal scheduling method for an electricity-gas integrated energy system considering carbon capture, and belongs to the technical field of optimal scheduling of integrated energy systems. Firstly, constructing a carbon-containing trapped electricity-gas comprehensive energy system; then constructing a low-carbon economic dispatching model of the carbon-containing trapped electricity-gas integrated energy system based on the system; the carbon-containing trapped electricity-gas integrated energy system low-carbon economic dispatching model is based on system operation cost and CO₂The minimum comprehensive cost of the sum of the related cost and the wind abandon punishment cost is an objective function, and the constraint conditions are electric power network constraint, natural gas network constraint, electric-to-gas equipment constraint, carbon capture system constraint, carbon storage and hydrogen storage equipment constraint. The invention not only can realize the bidirectional electrical coupling of the power network and the natural gas networkThe wind power is consumed to the maximum extent, carbon circulation can be formed through the carbon collecting device, the carbon emission reduction capability of the system is improved, and the system is easy to popularize and apply.

Description

Low-carbon optimized scheduling method of electricity-gas integrated energy system considering carbon capture

Technical Field

The invention belongs to the technical field of optimization scheduling of an integrated energy system, and particularly relates to a carbon capture considered low-carbon optimization scheduling method for an electricity-gas integrated energy system.

Background

Under the background that the global warming problem is becoming more serious, a series of green economic concepts such as 'carbon neutralization', 'carbon peak-reaching action' and the like are complied with and proposed. The electricity-gas comprehensive energy system plays an important role in green transformation of a future energy system due to the characteristics of supply and demand interaction, high comprehensive energy utilization rate and high operation efficiency. However, the traditional electric comprehensive energy system only couples the power network and the natural gas network through the electric-to-gas equipment singly, and still has the problem of high carbon emission, so that the research on how to operate the comprehensive energy system in a low-carbon and economic manner is of great significance to green transformation of the power industry.

The power generation of a thermal power generating unit at the side of a power grid in the comprehensive energy system is the largest carbon emission source, and the comprehensive energy system can adopt an effective method to increase the grid access rate of green energy such as wind power, photoelectricity and the like, change the production mode and develop a carbon capture technology. For the two methods, the following disadvantages exist: firstly, the wind power output is influenced by natural factors such as seasons, climate and the like, uncertainty exists, and as the scale of wind power grid connection is continuously increased, electricity is generatedThe stability and the safety of the operation of the power system are also influenced, and the popularization and the utilization of wind power in the comprehensive energy system are restricted by the problems of wind power access and consumption. And secondly, a carbon capture system is introduced into the traditional electricity-gas comprehensive energy system, so that the problem of large carbon emission is solved to a certain extent, but at present, the flexible operation between the carbon capture system and the electricity-gas conversion equipment and the mechanism for jointly consuming wind power by the carbon capture system and the electricity-gas conversion equipment are rarely researched after the carbon capture system is introduced. The coupling of a pure carbon capture system with an electric gas conversion device has certain disadvantages. Firstly, the methanation reaction of the electric-to-gas equipment in the electric comprehensive energy system consumes CO by using the residual electric energy only in the period of wind abandonment₂Synthesis of methane, but carbon capture system captures CO₂Possibly throughout the scheduling period, CO₂The imbalance of gas flow supply and demand causes unnecessary cost and waste of gas resources. Secondly, the application of the hydrogen is wide, and compared with the direct participation in methanation reaction, the hydrogen is used for the electric automobile market, a fuel cell and a hydrogen gas turbine to generate electricity or possibly bring better economic benefit.

Therefore, how to overcome the defects of the prior art is a problem to be solved urgently in the technical field of the optimization scheduling of the comprehensive energy system at present.

Disclosure of Invention

The invention aims to overcome the defects in the prior art and provides a low-carbon optimal scheduling method of an electricity-gas integrated energy system considering carbon capture.

In order to achieve the purpose, the technical scheme adopted by the invention is as follows:

a low-carbon optimized dispatching method for an electricity-gas integrated energy system considering carbon capture adopts the electricity-gas integrated energy system with carbon capture;

the carbon-containing trapped electrical comprehensive energy system comprises a conventional thermal power generating unit, a carbon trapping unit, carbon storage equipment, methanation equipment, hydrogen storage equipment, a gas turbine and electrolysis equipment; the carbon capture unit is a conventional thermal power unit additionally provided with a carbon capture system;

the conventional thermal power generating unit is connected with a carbon capture system of the carbon capture unit;

the carbon capture unit is respectively connected with the carbon storage equipment and the methanation equipment;

the methanation equipment is also respectively connected with the carbon storage equipment and the hydrogen storage equipment;

the hydrogen storage equipment is also respectively connected with the gas turbine and the electrolysis equipment;

the scheduling method comprises the following steps:

constructing a low-carbon economic dispatching model of the carbon-containing trapped electrical comprehensive energy system; the carbon-containing captured electrical comprehensive energy system low-carbon economic dispatching model is based on system operation cost and CO₂The minimum comprehensive cost of the sum of the related cost and the wind abandon punishment cost is a target function, and the constraint conditions are electric power network constraint, natural gas network constraint, electric-to-gas equipment constraint, carbon capture system constraint, carbon storage and hydrogen storage equipment constraint; said CO₂Associated costs include CO emissions from fossil fuel units₂Carbon tax cost F_CT、CO₂Transmission storage cost F_TsCarbon trapping unit for trapping CO from air₂Cost F of_CC(ii) a Then, solving is carried out, and scheduling is carried out according to the solving result.

Further, it is preferable that the objective function is:

min F＝F_O+F_C+F_W (1)

in the formula, F_o$ for system operating cost, $; f_cIs CO₂Associated cost, $; f_wPunishing cost for wind abandonment;

(1) the system operation cost comprises the operation cost F of the conventional thermal power generating unit_GGas production cost F of natural gas source_NωAnd natural gas storage

Gas cost F for gas facility_NS，$；

In the formula, N_G、N_ω、N_GsThe number of the conventional coal burners, the number of natural gas sources and the number of natural gas storage devices are respectively; n is a radical of_TIs a scheduling period; beta is a_i、β_ω、β_sThe unit is the fuel price of a conventional coal-fired unit i, the unit gas production cost of a natural gas source omega and the unit gas consumption cost of a natural gas storage device s, and the units are $/MBtu, $/kcf and $/kcf; a is_Gi、b_Gi、c_GiThe cost coefficient of the ith conventional thermal power generating unit; p_Gi，tThe output power, MW, of the conventional thermal power generating unit i at the moment t; q_ω，tThe gas production amount of the natural gas source omega at the time t is kcf:

dividing the natural gas storage device s into the natural gas injection and extraction amount at the time t, kcf;

(2)CO₂associated costs include CO emissions from fossil fuel units₂Carbon tax cost F_CT，$、CO₂Transmission storage cost F_TSAnd the carbon capture system captures CO from the air₂Cost F of_CC，$；

In the formula, N_FU、N_CC、N_CSRespectively representing the number of fossil fuel units, the number of carbon gathering units and the number of carbon storage equipment; beta is a_CT、β_TS、β_CCRespectively carbon tax price and unit CO₂Transportation and storage price of, capture of unit CO from air₂The required price cost in $/kcf; u. of_iCO for conventional coal-fired unit i₂The discharge intensity; p_i，tThe output power, MW, of the fossil fuel unit i at the moment t;

for CO trapped by carbon trapping machine set at time t₂Amount captured, kfc;

for supplying carbon from airs carbon dioxide flow, kfc/h;

the carbon dioxide flow rate for supplying the carbon capture unit with the carbon storage device s is kfc/h; the fossil fuel unit comprises a conventional thermal power unit and a gas unit;

(3) wind abandon penalty cost:

in the formula, N_WThe number of wind power plants; cw is a wind abandon punishment cost coefficient, $ MWh; p_w，tThe actual output value, MW, of the wind power plant in the time period t; and P' w and t are output predicted values, MW, of the wind power plant in the t period.

Further, preferably, the power network constraints include a power balance constraint, a rotation standby constraint, a unit operation constraint and a power grid operation safety and reliability constraint; the method specifically comprises the following steps:

1) power balance constraint

In the formula, A_b(.)Representing an association matrix of a fossil fuel unit, a wind power plant, an electric-to-gas device and a power transmission line associated with a power grid node b; n is a radical of_FU、N_W、N_PtG、N_TLThe total number of fossil fuel units, wind power plants, power-to-gas equipment and power transmission lines is respectively;

power, MW, to the input electrical to gas device; p_ED，b，tRepresents the electrical load at node b at time t, MW; PL_l，tThe transmission power of the transmission line l at the time t, MW;

2) rotational back-up restraint

In the formula, τ_i，tThe variable is 0-1 and represents the start-stop state of the fossil fuel unit i at the moment t, the value is 1 when the unit i starts to operate, and the value is 0 when the unit i stops operating; p_i，min、P_i，maxRespectively representing the lower limit, the upper limit and the MW of the output of the fossil fuel unit i;

respectively representing the up-regulation reserve capacity demand value and the down-regulation reserve capacity demand value MW which are at least required to be met by the power system at the moment t;

3) the unit operation constraints comprise wind power output constraints, fossil fuel unit output constraints, climbing rate constraint minimum startup and shutdown time constraints and startup and shutdown energy consumption constraints, and specifically comprise the following steps:

wind power output constraint:

0≤P_w，t≤P′_w，t (7)

output constraint of fossil fuel units:

τ_i，tP_i，min≤P_i，t≤τ_i，tP_i，max (8)

third, climbing speed constraint:

in the formula, S_up，i、S_dn，iRespectively representing the upward and downward climbing rates, MW, of the fossil fuel unit i; p_i，t+1The output power, MW, of the fossil fuel unit i at the moment t + 1; tau is_i，t+1The variable is 0-1 and represents the start-stop state of the fossil fuel unit i at the moment of t + 1;

and fourthly, constraint of minimum start-up and shut-down time:

in the formula (I), the compound is shown in the specification,

respectively representing the minimum time interval number h of starting and stopping the fossil fuel unit i;

respectively indicating the number h of the periods when the fossil fuel unit i is continuously started and stopped in the period t-1; tau is_i，t-1The variable is 0-1 and represents the start-stop state of the fossil fuel unit i at the time t-1;

energy consumption constraint of starting and stopping

In the formula, su_i、sd_iRespectively representing the starting and stopping energy consumption, MBtu, of the fossil fuel unit i; SU_i，t、SD_i，tRespectively representing the starting-up and stopping energy consumption, MBtu, of the fossil fuel unit i at the time t;

4) power grid operation safety and reliability constraint

PL_l，t＝(π_l1，t-π_l2，t)/x_l (12)

In the formula, pi_l1，t、π_l2，tThe voltage phase angle values, rad, of the head end and the tail end of the power transmission line l at the time t are respectively; x is the number of_lIs the reactance value of line l, p.u.;

the line transmission power constraint and the node voltage angle constraint are as follows:

in the formula, PL_l，min、PL_l，maxRespectively the minimum and maximum active power, MW, transmitted by the line l; pi_ref、π_b，min、π_b，max、π_b，tRespectively representing the voltage phase angle value of the reference node and the minimum and maximum voltage phase angle values of the node b, the actual voltage phase at the time tAngle value, rad.

Further, preferably, the natural gas network constraints include gas source gas production constraints, natural gas pipeline flow constraints, natural gas storage equipment constraints, node pressure constraints and node supply and demand balance constraints;

1) gas source gas production constraint

Q_ω，min≤Q_ω，t≤Q_ω，max (14)

In the formula, Q_ω，min、Q_ω，maxThe unit of the lower limit value and the upper limit value of the omega gas production of the natural gas source is kcf;

2) natural gas pipeline flow restriction

For a natural gas pipeline mn, gas flows from m node to n node, and the pipeline gas flow is expressed as:

in the formula, Q_mn，tThe gas flow rate of the natural gas pipeline mn flowing at the time t is kcf/h; sgn (p)_m，t，p_n，t) The direction of gas flow is shown, when the direction is 1, the gas flows from the m node to the n node, and when the direction is-1, the gas flows from the n node to the m node; p_m，t、p_n，tPressure values at nodes m and n at the time t, Psig; c_mnIs the pipeline constant;

for a natural gas pipeline mn with a compressor j, the compression ratio between the output node and the input node is constrained by:

in the formula, R_j，max、R_j，minMaximum and minimum values of the allowable compressor compression ratio;

3) natural gas storage equipment restraint

The gas storage amount of the gas storage equipment at any time t in the operation process

Expressed as:

in the formula (I), the compound is shown in the specification,

indicating the gas storage amount of the gas storage device s at the time t and t-1, respectively, kcf;

dividing the natural gas storage device s into the natural gas injection and extraction amount at t moment, kcf/h; Δ t is the time step;

respectively representing the minimum and maximum gas storage capacities of the gas storage device s, kcf;

respectively representing the maximum gas injection and extraction flow rates of natural gas storage equipment s, kcf/h;

respectively representing the gas capacity of the gas storage device s at the initial and ending moments of a scheduling period, kcf;

4) nodal pressure constraint

For the natural gas node m, the pressure magnitude should satisfy the following constraint:

p_m，min≤p_m，t≤p_m，max (18)

in the formula, p_m，min、p_m，maxRespectively representing the lower limit and the upper limit of the pressure value of the node m;

5) node supply and demand balance constraints

For natural gas node m, the equilibrium equation is as follows:

in the formula, N_ω、N_Gs、N_PtG、N_NU、N_GPRespectively indicating the quantity of the gas source, the gas storage facility, the electric gas conversion equipment, the gas unit and the gas transmission pipeline; b is_m(.)Representing a correlation matrix associated with a natural gas node m;

the amount of the methane gas synthesized by PtG equipment is kcf/h; q_Ni，tThe natural gas consumption of the gas unit i at the time t is kcf/h; q_GL，m，tThe air load at the time t at the node m is kcf/h; q_mn，tThe natural gas flow rate flowing through the pipeline mn in the period t is kcf/h.

Further, preferably, the electric transfer device is constrained by:

the hydrogen quantity generated by the electrolytic hydrogen production reaction of the electric gas conversion equipment

Expressed as:

in the formula (I), the compound is shown in the specification,

the unit of the hydrogen quantity generated by the electrolytic hydrogen production reaction of the electrolysis equipment is kcf/h;

power, MW, for input to the electrical to gas equipment;

hydrogen production efficiency in the electrolysis reaction; xi_e，gMBtu/MWh, which is the equivalent thermal energy coefficient;

high heating value of hydrogen, MBtu/kcf；

The upper and lower limits of the power input into the electric gas conversion equipment in the electrolytic reaction are respectively 20% and 5% of the designed capacity, so that the input power of the electric gas conversion equipment can meet the following constraint:

in the formula, τ_ptgThe variable is 0-1, which represents the running state of the electric gas conversion device, and the value is 1 when the electric gas conversion device runs and 0 when the electric gas conversion device stops running;

the lower limit value, the upper limit value and the MW of the allowable input power of the electric gas conversion device are respectively set;

CO consumed by methanation₂The amounts and the amount of methane gas produced are expressed as:

in the formula (I), the compound is shown in the specification,

CO consumed for methanation reactions₂Amount, kcf/h;

the amount of methane gas synthesized by methanation reaction is kcf/h;

the hydrogen flow taken off for the hydrogen storage device s for the synthesis of methane, kcf/h;

the reaction coefficients between hydrogen and carbon dioxide, hydrogen and methane;

meanwhile, the heat energy generated by methanation reaction is as follows:

in the formula (I), the compound is shown in the specification,

the recovered thermal power, MW, for the electric gas-converting equipment; Ψ_heatMWh/kcf for heat recovery coefficient;

further, it is preferred that the carbon capture system is constrained by:

the carbon capture unit operation model is represented as follows:

in the formula, P_cEquivalent output power, MW; p_c ^netNet output power, MW; p_c ^conFor capturing CO₂Required energy consumption, MW; maintenance energy consumption P_c ^mIs a fixed value, MW; p_c ^oEnergy consumption for operation, MW;

CO that can be processed for carbon capture systems₂Amount, kcf/h; gamma ray_cFor the carbon capture unit c to capture unit CO₂The energy consumption generated is kfc/MWh;

the carbon capture unit generates equivalent output power and simultaneously generates carbon dioxide Q according to a certain proportion_c：

In the formula, mu_cCO for carbon capture train c₂Emission intensity, kfc/MWh;

CO for carbon capture train c₂Trapping capacity, kcf/h; beta is a_cCO for carbon capture train c₂The capture rate;

in summary, the net output power of the carbon capture unit is expressed as:

P_c ^net＝P_c-P_c ^m-P_c ^o (26)

and the net output power meets the output limit constraint:

in the formula (I), the compound is shown in the specification,

respectively the minimum and maximum net power values allowed to be output by the carbon capture unit;

further, preferably, the constraints of the carbon storage and hydrogen storage device are as follows:

1) hydrogen storage apparatus

In the formula (I), the compound is shown in the specification,

the hydrogen flow rate injected for the hydrogen storage device s, kcf/h;

the hydrogen storage amounts of the hydrogen storage equipment s at the times t and t-1, respectively, kcf;

dividing into kcf/h hydrogen injection and extraction quantity of hydrogen storage equipment s at t moment;

respectively representing the minimum and maximum hydrogen storage capacities of the hydrogen storage device s, kcf;

respectively representing the maximum hydrogen injection and extraction flow rates of the hydrogen storage device s, kcf/h; n is a radical of_TIs the end time of a scheduling period, h;

respectively representing the hydrogen capacities of the hydrogen storage equipment at the initial and end moments of a scheduling period, wherein the hydrogen capacities of the hydrogen storage equipment and the hydrogen capacity are equal, kcf;

the hydrogen required by the methanation equipment and the gas turbine is from the hydrogen storage equipment, so the hydrogen flow rate should satisfy the following constraints:

in the formula

Representing the hydrogen flow rate of the hydrogen storage device to the gas turbine, kcf/h;

2) carbon storage equipment

Carbon storage amount of carbon storage equipment at any moment in operation process

Expressed as:

in the formula (I), the compound is shown in the specification,

respectively representing CO of the carbon storage equipment at t and t-1₂Capacity, kfc;

respectively representing CO of carbon storage equipment s at time t₂The injection and extraction flow rates are kcf/h;

corresponding carbon storage facility capacity constraint, CO₂The injection quantity and the extraction quantity of the flow are restricted in one scheduling periodInitial, end CO₂The capacity constraints are as follows:

in the formula (I), the compound is shown in the specification,

respectively representing minimum and maximum CO of carbon storage facility s₂Storage capacity, kfc;

CO of carbon storage equipment s at t moment₂The injection and extraction amount is kcf/h;

respectively representing CO of carbon storage units s₂The maximum injection and extraction flow rate is kcf/h;

respectively representing CO of carbon storage equipment at the initial and end time of a scheduling period₂Capacity, kcf:

CO trapped by carbon trapping system in carbon removal trapping unit₂CO of carbon storage equipment₂The injected amount also comes from CO captured in the air₂Expressed as:

in the formula (I), the compound is shown in the specification,

the flow rate of carbon dioxide supplied from the carbon capture unit to the carbon storage facility s at time t is shown at kcf.

The invention also provides the carbon-containing trapping electricity-gas comprehensive energy system.

The invention also provides an electronic device comprising a memory, a processor and a computer program stored on the memory and executable on the processor, wherein the processor executes the program to implement the steps of the low-carbon optimal scheduling method for the electricity-gas integrated energy system considering carbon capture as described above.

The invention also provides a non-transitory computer-readable storage medium having a computer program stored thereon, wherein the computer program, when executed by a processor, implements the steps of the method for low-carbon optimal scheduling of an electric-gas integrated energy system in consideration of carbon capture as described above.

In the present invention, a_Gi、b_Gi、c_GiThe cost coefficient of the ith conventional thermal power generating unit can be found from an electric power regulation manual, a network or a factory nameplate of an actual generator manufacturer.

In the present invention, the fossil fuel power plant includes a conventional thermal power plant N_GAnd gas turbine unit N_NUPower calculation system-P involving both_iAnd (4) showing.

In the present invention, C_mnIs a pipe constant, the size depending on diameter, length, coefficient of friction, gas composition, etc., kcf/Psig; the specific calculation is only needed by the calculation of the prior art content and the related formula. And delta t is a time step, and is preferably 1 h. N is a radical of_TThe value is 24h for one scheduling period.

The preferred value is 0.73 for the hydrogen production efficiency in the electrolysis reaction; zeta_e，gThe value is 3.41, MBtu/MWh;

the high heat value of the hydrogen is preferably 0.342;

the reaction coefficients of hydrogen and carbon dioxide and hydrogen and methane are all 0.25; Ψ_heatThe MWh/kcf value is 0.0126 for the heat recovery coefficient. Maintenance energy consumption P_c ^mIs a fixed value, is the lowest energy consumption for maintaining the operation of the carbon capture unit, andthe running state of the carbon capture unit is irrelevant, and the value of the actual running condition can be generally 10-20% of the rated power of the carbon capture unit. P_c ^oThe value of MW, which is the operation energy consumption, changes along with the change of the operation state of the carbon capture unit and is positively correlated with the carbon dioxide capture capacity of the carbon capture unit. Beta is a_cCO for carbon capture train c₂The trapping rate, which is 0.9:

the invention discloses a low-carbon optimal scheduling method of an electricity-gas integrated energy system considering carbon capture, aiming at the problem of wind abandon caused by new energy access in the electricity-gas integrated energy system and the problem of carbon emission of a thermal power generating unit. Firstly, on the basis of a traditional electricity-gas integrated energy system, a carbon capture system is additionally arranged on a conventional thermal power generating unit to form a carbon capture unit, and CO is captured₂And the carbon emission of the unit is reduced by trapping.

And carbon dioxide (CO) capture based on carbon capture system₂) While methanation reactions in the electric gas-conversion plant (P2G) consume CO₂The system forms carbon cycle in the scheduling period by taking the joint operation mode of the carbon storage and hydrogen storage equipment into consideration. Reduction of P2G facility for purchasing CO from methanation reactions₂And increases the net output power of the carbon capture plant. Secondly, in this combined mode of operation, the cost of operation of the system, CO₂The minimum comprehensive cost of the sum of the related cost and the wind abandon punishment cost is an objective function, an environment economic dispatching model of the carbon-containing capture electric comprehensive energy system is constructed, and the constraints of an electric power network, a natural gas network, an electric gas conversion device, a carbon capture system and carbon and hydrogen storage devices are considered. Finally, the model is compared and verified under different simulation scenes, and the result shows that: compared with the traditional comprehensive energy system architecture, the system of the invention not only can realize the bidirectional electrical coupling of the power network and the natural gas network by introducing the carbon capture unit, the carbon storage equipment and the hydrogen storage equipment 3, and furthest consume the wind power, but also can form carbon circulation through the carbon capture device, improve the carbon emission reduction capability of the system, ensure that the system has both economy and environmental protection, and has important theoretical performance under the background of carbon neutralizationValue and practical significance.

Preferably, the model is solved by using MATLAB to call GUROBI.

According to the invention, the carbon storage equipment is additionally arranged between the carbon capture system and the methanation equipment, so that CO required by the methanation reaction₂The gas quantity is provided by the carbon storage equipment, the transmission of the gas flow in the carbon circulation process is balanced, the resource waste is reduced, and the flexible operation capacity of the carbon capture power plant is improved.

According to the invention, the hydrogen storage equipment is arranged between the electrolysis equipment and the methanation equipment, so that the two processes of electricity-to-natural gas and electricity-to-hydrogen are decoupled. The electrolytic hydrogen production by wind power can be absorbed to the maximum extent through the electrolytic reaction, and the hydrogen extraction amount is supplied for methanation reaction, and the hydrogen can also be used for power generation of a gas turbine, so that better economic benefit is created.

Under the combined operation mode, the wind power can be basically fully consumed in the scheduling period, and the optimal economic scheduling in the whole day is realized. Meanwhile, the comprehensive operation cost and the carbon emission of the system are optimal, and the economical efficiency and the environmental protection performance of the system are greatly improved.

Compared with the prior art, the invention has the beneficial effects that:

1. the invention is improved on the basis of the traditional electricity-gas integrated energy system, introduces the carbon capture system, provides a combined operation mode of carbon storage and hydrogen storage equipment between the carbon capture and electricity-gas conversion equipment, realizes the carbon circulation of the electricity-gas integrated energy system in a scheduling period, and reduces the purchase of CO by the electricity-gas conversion equipment due to methanation reaction₂The cost of the method increases the net output power of the power plant of the carbon-containing capture system by nearly 10-15%.

2. In a combined operation mode, the flexible operation capacity of the carbon capture power plant and the electricity-to-gas equipment is remarkably improved, the full consumption of wind power can be basically realized in a scheduling period, the penalty cost of wind abandoning is basically 0, and the optimal economic scheduling in the whole day is realized.

3. In combined operation mode, the carbon capture unit captures CO₂The carbon emission of the electricity-gas integrated energy system is reduced, and compared with the carbon capture system which is not additionally arranged, the carbon emission reduction of the power plant in a combined operation modeThe height is about 31.2%; compared with the method that the carbon capture system is additionally arranged but the combined operation mode is not considered, the carbon emission reduction of the power plant is improved by nearly 7.5 percent, and the environmental cost of the system is greatly reduced.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to these drawings without creative efforts.

FIG. 1 is a block diagram of a 6-node power system and a 7-node natural gas system;

FIG. 2 is a graph of predicted values of power load, natural gas load, and wind power;

FIG. 3 is a wind power consumption comparison diagram under three scenes;

FIG. 4 is a comparison graph of the output of the carbon capture unit 5 under three scenes;

FIG. 5 is a diagram of the carbon capture and recovery heat energy of the unit 5 in scenario 3;

FIG. 6 shows CO under three scenarios₂Emission and CO₂A collection amount graph;

FIG. 7 is a schematic diagram of the configuration of an electric-gas integrated energy system for carbon capture according to the present invention;

FIG. 8 is a schematic view of the operation of the integrated electric-gas energy system for carbon capture according to the present invention;

fig. 9 is a schematic structural diagram of an electronic device according to the present invention.

Detailed Description

The present invention will be described in further detail with reference to examples.

It will be appreciated by those skilled in the art that the following examples are illustrative of the invention only and should not be taken as limiting the scope of the invention. The examples are given without reference to the specific techniques or conditions, according to the techniques or conditions described in the literature in the field or according to the product description. The materials or equipment used are not indicated by manufacturers, and all are conventional products available by purchase.

A low-carbon optimal scheduling method of an electricity-gas integrated energy system considering carbon capture comprises the following steps:

one, construct the electricity that contains the carbon entrapment-gas comprehensive energy system

The system comprises an electric power network, a natural gas network, a carbon capture system and an electric gas conversion device. Specifically, as shown in fig. 7 and 8, the carbon-containing capture electricity-gas integrated energy system comprises a conventional thermal power generating unit, a carbon capture unit, a carbon storage device, a methanation device, a hydrogen storage device, a gas turbine and an electrolysis device; the carbon capture unit is a conventional thermal power unit additionally provided with a carbon capture system;

secondly, a combined operation mode of the carbon storage and hydrogen storage equipment is provided

A carbon storage device is additionally arranged between the carbon capture system and the methanation device, so that CO required by the methanation reaction₂The gas quantity is provided by the carbon storage equipment, the transmission of the gas flow in the carbon circulation process is balanced, the resource waste is reduced, and the flexible operation capacity of the carbon capture power plant is improved. The hydrogen storage equipment is arranged between the electrolysis equipment and the methanation equipment, so that the decoupling of the two processes of electricity-to-natural gas and electricity-to-hydrogen is realized. The electrolytic hydrogen production by wind power can be absorbed to the maximum extent through the electrolytic reaction, and the hydrogen extraction quantity is supplied to methanation reaction, and the hydrogen can also be used for power generation of a gas turbine, so that better economic benefit is created.

Thirdly, constructing a low-carbon economic dispatching model of the carbon-trapping electricity-gas integrated energy system

The model uses the system running cost, CO₂The minimum comprehensive cost of the sum of the related cost and the wind curtailment cost is an objective function, and the electric power network constraint, the natural gas network constraint and the coupling are consideredSynthesizing unit constraints and considering carbon storage and carbon capture system constraints of the hydrogen storage device. The method comprises the following specific steps:

1. objective function

The carbon capture-containing electrical integrated energy system eco-economic dispatch is optimized with minimum integrated cost in a combined mode of operation.

min F＝F_O+F_C+F_W (1)

In the formula, F_O$ for system operating cost, $; f_CIs CO₂Associated cost, $; f_WPunishment cost for wind abandon, $.

(1) The system operation cost comprises the operation cost F of the conventional thermal power generating unit_GAnd the sound and gas cost F of the natural gas source_NωGas cost F of natural gas storage facility_NS，$：

In the formula, N_G、N_ω、N_GsThe number of the conventional coal burners, the number of natural gas sources and the number of natural gas storage devices are respectively; n is a radical of_TTaking the value of 24h for one scheduling period; beta is a_i、β_ω、β_sThe unit is the fuel price of a conventional coal-fired unit i, the unit gas production cost of a natural gas source omega and the unit gas consumption cost of a natural gas storage device s, and the units are $/MBtu, $/kcf and $/kcf; a is_Gi、b_Gi、c_GiThe cost coefficient of the ith conventional thermal power generating unit; p_Gi，tThe output power, MW, of the conventional thermal power generating unit i at the moment t; q_ω，tBeta gas quantity at time t for natural gas source omega, kcf;

(2)CO₂associated costs include CO emissions from fossil fuel units₂Carbon tax cost F_CT，$、CO₂Is transmitted and storedCost F_TSAnd the carbon capture system captures CO from the air₂Cost F of_CC，$；

In the formula, N_FU、N_CC、N_CSRespectively representing the number of fossil fuel units, the number of carbon gathering units and the number of carbon storage equipment; beta is a_CT、β_TS、β_CCRespectively carbon tax price and unit CO₂Transportation and storage price of, capture of unit CO from air₂The required price cost, in $/kcf: u. of_iCO for conventional coal-fired unit i₂The discharge intensity; p_i，tThe output power, MW, of the fossil fuel unit i at the moment t;

for CO trapped by carbon trapping machine set at time t₂Amount captured, kfc;

the flow rate of carbon dioxide supplied from the air to the carbon storage facility s, kfc/h;

(3) wind abandon penalty cost:

in the formula, N_WThe number of wind power plants; cw is a wind abandon punishment cost coefficient, $ MWh; p_w，tThe actual output value, MW, of the wind power plant in the time period t; p' w, t is the output predicted value, MW of the wind power plant in the period t;

2. constraint conditions

Including power network constraints, natural gas network constraints, coupling unit constraints, and carbon capture system constraints that take into account carbon storage, hydrogen storage facilities. The method comprises the following specific steps:

(1) power network constraints

The power network constraint comprises a power balance constraint, a rotation standby constraint, a unit operation constraint and a power grid operation safety and reliability constraint; the concrete is as follows:

1) power balance constraint

2) rotational back-up restraint

wind power output constraint:

0≤P_w，t≤P′_w，t (7)

output constraint of fossil fuel units:

τ_i，tP_i，min≤P_i，t≤τ_t，tP_t，max (8)

third, climbing speed constraint:

and fourthly, constraint of minimum start-up and shut-down time:

in the formula (I), the compound is shown in the specification,

respectively indicating the number h of the periods when the fossil fuel unit i is continuously started and stopped in the period t-1; tau is_i，t-1And the variable is a 0-1 variable and represents the start-stop state of the fossil fuel unit i at the time t-1.

Energy consumption constraint of starting and stopping

4) power grid operation safety and reliability constraint

PL_l，t＝(π_l1，t-π_l2，t)/x_l (12)

in the formula, PL_l，min、PL_l，maxRespectively the minimum and maximum active power, MW, transmitted by the line l; pi_ref、π_b，min、π_b，max、π_b，tRespectively, the voltage phase angle value of the reference node and the minimum and maximum voltage phase angle values of node b, the actual voltage phase angle value at time t, rad.

(2) Natural gas network constraints

The natural gas network constraints comprise gas source gas production constraints, natural gas pipeline flow constraints, natural gas storage equipment constraints, node pressure constraints and node supply and demand balance constraints;

1) beta gas confinement of gas source

Q_ω，min≤Q_ω，t≤Q_ω，max (14)

In the formula, Q_ω，min、Q_ω，maxThe unit of the lower limit value and the upper limit value of the gas production rate of the natural gas source omega is kcf:

2) natural gas pipeline flow restriction

in the formula, Q_mn，tThe gas flow rate of the natural gas pipeline mn flowing at the time t is kcf/h; sgn (p)_m，t，p_n，t) The direction of gas flow is shown, when the direction is 1, the gas flows from the m node to the n node, and when the direction is-1, the gas flows from the n node to the m node; p is a radical of_m，t、p_n，tPressure values at nodes m and n at the time t, Psig; c_mnThe size is a pipe constant and depends on diameter, length, coefficient of friction, gas composition, etc., kcf/Psig.

3) natural gas storage equipment restraint

The gas storage capacity of the gas storage equipment at any time t in the operation process

Expressed as:

in the formula (I), the compound is shown in the specification,

4) nodal pressure constraint

p_m，min≤p_m，t≤p_m，max (18)

5) node supply and demand balance constraints

For natural gas node m, the equilibrium equation is as follows:

the amount of the methane gas synthesized by PtG equipment is kcf/h; q_Ni，tThe natural gas consumption of the gas unit i at the time t is kcf/h; q_GL，m，tThe air load at the time t at the node m is kcf/h; q_mn，tThe natural gas flow rate flowing through the pipeline mn in the period t is kef/h.

(3) Electric gas conversion equipment restraint

Expressed as:

in the formula (I), the compound is shown in the specification,

the unit of the hydrogen generated by the electrolysis hydrogen production reaction beta of the electrolysis equipment is kcf/h;

to input power to the electrical conversion device, MW:

hydrogen production efficiency in the electrolysis reaction; zeta_e，gMBtu/MWh, which is the equivalent thermal energy coefficient;

high heating value for hydrogen, MBtu/kcf;

the upper and lower limits of the power input into the electric gas conversion device in the electrolytic reaction are respectively 20% and 5% of the designed capacity, so the input power of the PtG device should satisfy the following constraint:

in the formula (I), the compound is shown in the specification,

CO consumed for methanation reactions₂Amount, kcf/h;

the amount of methane gas synthesized by methanation reaction is kcf/h;

the reaction coefficients between hydrogen and carbon dioxide, hydrogen and methane are shown;

meanwhile, the heat energy generated by methanation reaction is as follows:

in the formula (I), the compound is shown in the specification,

(4) carbon capture system constraints

The carbon capture unit operation model is represented as follows:

in the formula, P_cEquivalent output power, MW; p_c ^netNet output power, MW; p_c ^conEnergy consumption, MW, required to capture CO 2; maintenance energy consumption P_c ^mIs a fixed value, MW; p_c ^oEnergy consumption for operation, MW;

in summary, the net output power of the carbon capture unit is expressed as:

P_c ^net＝P_c-P_c ^m-P_c ^o (26)

and the net output power meets the output limit constraint:

in the formula (I), the compound is shown in the specification,

(5) carbon and hydrogen storage equipment restraint

1) Hydrogen storage apparatus

In the formula (I), the compound is shown in the specification,

the hydrogen flow rate injected for the hydrogen storage device s, kcf/h;

in the formula

2) carbon storage equipment

Expressed as:

in the formula (I), the compound is shown in the specification,

corresponding carbon storage facility capacity constraint, CO₂The injection quantity and the extraction quantity of the flow are restricted, and the CO at the initial and the end in a scheduling period₂The capacity constraints are as follows:

in the formula (I), the compound is shown in the specification,

respectively representing CO of carbon storage equipment at the initial and end time of a scheduling period₂Capacity, kcf;

in the formula (I), the compound is shown in the specification,

Fig. 9 is a schematic structural diagram of an electronic device according to an embodiment of the present invention, and referring to fig. 9, the electronic device may include: a processor (processor)201, a communication Interface (communication Interface)202, a memory (memory)203 and a communication bus 204, wherein the processor 201, the communication Interface 202 and the memory 203 complete communication with each other through the communication bus 204. The processor 201 may call logic instructions in the memory 203 to perform the following method: constructing a low-carbon economic dispatching model of the carbon-containing trapped electrical comprehensive energy system; the low-carbon economic dispatching model of the carbon-containing captured electrical comprehensive energy system is based on system operation cost and CO₂The minimum comprehensive cost of the sum of the related cost and the wind abandoning penalty cost is a target function, and the power network constraint, the natural gas network constraint and the electricity-to-gas conversion are usedThe equipment constraint, the carbon capture system constraint and the carbon storage and hydrogen storage equipment constraint are constraint conditions; said CO₂Associated costs include CO emissions from fossil fuel units₂Carbon tax cost F_CT、CO₂Transmission storage cost F_TSCarbon trapping unit for trapping CO from air₂Cost F of_CC(ii) a Then, solving is carried out, and scheduling is carried out according to the solving result.

In addition, the logic instructions in the memory 203 may be implemented in the form of software functional units and stored in a computer readable storage medium when the logic instructions are sold or used as independent products. Based on such understanding, the technical solution of the present invention may be embodied in the form of a software product, which is stored in a storage medium and includes instructions for causing a computer device (which may be a personal computer, a server, or a network device) to execute all or part of the steps of the method according to the embodiments of the present invention. And the aforementioned storage medium includes: a U-disk, a removable hard disk, a Read-Only Memory (ROM), a Random Access Memory (RAM), a magnetic disk or an optical disk, and other various media capable of storing program codes.

In another aspect, an embodiment of the present invention further provides a non-transitory computer-readable storage medium, on which a computer program is stored, which when executed by a processor, is implemented to perform a method for low-carbon optimal scheduling of an electricity-gas integrated energy system considering carbon capture according to the embodiments, for example, the method includes: constructing a low-carbon economic dispatching model of the carbon-containing trapped electrical comprehensive energy system; the low-carbon economic dispatching model of the carbon-containing captured electrical comprehensive energy system is based on system operation cost and CO₂The minimum comprehensive cost of the sum of the related cost and the wind abandon punishment cost is an objective function, and the constraint conditions are power network constraint, natural gas network constraint, electric-to-gas equipment constraint, carbon capture system constraint, carbon storage and hydrogen storage equipment constraint; said CO₂Associated costs include fossil fuel unit emissionsCO₂Carbon tax cost F_CT、CO₂Transmission storage cost F_TSCarbon trapping unit for trapping CO from air₂Cost F of_CC(ii) a Then, solving is carried out, and scheduling is carried out according to the solving result.

The above-described embodiments of the apparatus are merely illustrative, and the units described as separate parts may or may not be physically separate, and parts displayed as units may or may not be physical units, may be located in one place, or may be distributed on a plurality of network units. Some or all of the modules may be selected according to actual needs to achieve the purpose of the solution of the present embodiment. One of ordinary skill in the art can understand and implement it without inventive effort.

Through the above description of the embodiments, those skilled in the art will clearly understand that each embodiment can be implemented by software plus a necessary general hardware platform, and certainly can also be implemented by hardware. With this understanding in mind, the above-described technical solutions may be embodied in the form of a software product, which can be stored in a computer-readable storage medium, such as ROM/RAM, magnetic disk, optical disk, etc., and includes instructions for causing a computer device (which may be a personal computer, a server, or a network device) to execute the method according to the embodiments or some parts of the embodiments.

Examples of the applications

In the description, based on a 6-node power system and a 7-node natural gas system network model in fig. 1, three simulation scenes are set for comparative simulation analysis, and the feasibility and the effectiveness of the method are verified.

Scene 1: environmental economic dispatch of typical integrated energy system

Scene 2: integrated energy system environmental economic dispatch of carbonaceous capture system

Scene 3: comprehensive energy system environment economic dispatch in combined operation mode of carbon storage and hydrogen storage equipment

And setting the parameters of the system as follows: the prediction curves of the power load, the natural gas load and the wind power output are shown in fig. 2. In addition, the rotating standby requirement value in the system scheduling period in the power network is 30% of the total load; the lower limit value of the allowable input power of the electric gas conversion equipment is 10MW, and the upper limit value of the allowable input power of the electric gas conversion equipment is 100 MW; maintaining energy consumption of the carbon capture system to be a fixed value, and taking 0.5% of the installed capacity of the unit; carbon tax value of 20$/t, transmission storage unit CO₂The price of the carbon dioxide is 5$/t, and the unit CO is captured from the air₂The required price cost takes the value of 200 $/t. And (4) carrying out optimization analysis on the electricity-gas comprehensive energy system within 24h in one day by taking 1h as a time interval.

The method comprises the steps of calling Gurobi optimization software through MATLAB to carry out simulation solution on environment economic optimization scheduling of an electricity-gas comprehensive energy network in three scenes within 24h a day, and obtaining wind power consumption, net output power of a carbon capture unit, system carbon emission and target optimization results in the three scenes. The results show that:

1) wind power consumption condition and analysis: as can be seen from the wind power consumption comparison graphs in the three scenes in fig. 3, a large amount of abandoned wind occurs in the scene 1, so that the penalty cost of the system is increased, a small amount of abandoned wind still exists in the scene 2, and the carbon storage and hydrogen storage units are added in the scene 3, so that the flexible operation capacity of the carbon capture power plant and the electricity-to-gas conversion equipment can be improved, and the full consumption of the wind power can be basically realized in the scheduling period.

2) Analyzing the output condition of the carbon capture unit: fig. 4 shows the net output power curve of the unit 5 in three scenarios, in scenario 2, the unit itself provides the capture energy required for the operation of the capture system, so the net output of the unit 5 in scenario 2 is lower than that in scenario 1. In the combined operation mode of scene 3, the carbon capture system recycles the heat released by the methanation reaction (as shown in fig. 5), and reduces the operation energy consumption of the carbon capture system, so that the net output power of the unit 5 is higher than that of scene 2. In addition, the recovered heat energy cannot fully compensate for the energy consumption of the carbon capture operation, and the unit itself still needs to provide a part of the energy consumption, so the net output of the unit 5 in the scene 3 is still lower than that in the scene 1 as a whole.

3) Carbon emission analysis under three scenarios: CO under three scenes in FIG. 6₂Emission and CO₂The capture amount graph shows that the carbon capture unit 5 can capture CO in scene 3₂The most amount, the lowest carbon emission.

4) Target optimization results and analysis: CO under different scenes₂The associated cost pairs are shown in table 1. CO Capture from air in scenario 3₂Greatly reduced cost, CO₂The associated cost is optimal under 3 scenes. The system cost and the comprehensive cost under the three scenes are shown in a table 2, and the table shows that the system comprehensive cost, the system operation cost, the CO2 related cost and the wind abandon penalty cost in the scene 3 are the optimal values under the three scenes.

TABLE 1 CO under different scenarios₂Correlation cost comparison table

Scene	CO₂Associated cost/$	Carbon tax cost/$	CO capture from air₂Cost/$	Cost of transfer storage/$
					Scene 1	196336.64	190950.00	5386.64	0
Scene 2	134472.14	131405.42	1532.45	1534.27
					Scene 3	132969.90	131364.98	0	1601.92

TABLE 2 comparison table of comprehensive cost of system under different scenes

Scene	Integrated cost/$	System operating cost/$	CO₂Associated cost/$	Wind curtailment penalty cost/$
					Scene 1	498563.89	267576.90	196336.64	34650.35
Scene 2	422075.47	282461.58	134472.14	5141.75
					Scene 3	387701.92	254732.02	132969.90	0

Compared with the traditional electricity-gas comprehensive energy system, the invention provides a combined operation mode of considering carbon storage and hydrogen storage equipment between the carbon capture equipment and the electricity-gas conversion equipment by introducing the carbon capture system, thereby realizing the carbon circulation of the comprehensive energy system in a scheduling period, reducing the carbon emission and lowering the environmental cost of the system; the wind power is fully consumed in the dispatching period, the net output power of the carbon capture power plant is improved, and the optimal economic dispatching in all days is realized.

The foregoing shows and describes the general principles, essential features, and advantages of the invention. It will be understood by those skilled in the art that the present invention is not limited to the embodiments described above, which are given by way of illustration of the principles of the present invention, and that various changes and modifications may be made without departing from the spirit and scope of the invention as defined by the appended claims. The scope of the invention is defined by the appended claims and equivalents thereof.

Claims

1. A low-carbon optimized dispatching method of an electricity-gas integrated energy system considering carbon capture is characterized in that the electricity-gas integrated energy system with carbon capture is adopted;

the carbon-containing trapped electricity-gas comprehensive energy system comprises a conventional thermal power generating unit, a carbon trapping unit, carbon storage equipment, methanation equipment, hydrogen storage equipment, a gas turbine and electrolysis equipment; the carbon capture unit is a conventional thermal power unit additionally provided with a carbon capture system;

the scheduling method comprises the following steps:

constructing a low-carbon economic dispatching model of the carbon-containing trapped electricity-gas integrated energy system; the carbon-containing trapped electricity-gas integrated energy system low-carbon economic dispatching model is based on system operation cost and CO₂The minimum comprehensive cost of the sum of the related cost and the wind abandon punishment cost is an objective function, and the constraint conditions are power network constraint, natural gas network constraint, electric-to-gas equipment constraint, carbon capture system constraint, carbon storage and hydrogen storage equipment constraint; said CO₂Associated costs include CO emissions from fossil fuel units₂Carbon tax cost F_CT、CO₂Transmission storage cost F_TSCarbon trapping unit for trapping CO from air₂Cost F of_CC(ii) a Then, solving is carried out, and scheduling is carried out according to the solving result.

2. The carbon capture-considered low-carbon optimal scheduling method for the electricity-gas integrated energy system according to claim 1, wherein the objective function is as follows:

minF＝F_O+F_C+F_W(1)

(1) the system operation cost comprises the operation cost F of the conventional thermal power generating unit_GGas production cost F of natural gas source_NωGas cost F of natural gas storage facility_NS，$；

In the formula, N_G、N_ω、N_GsThe number of the conventional coal burners, the number of natural gas sources and the number of natural gas storage devices are respectively; n is a radical of_TIs a scheduling period; beta is a_i、β_ω、β_sThe unit is the fuel price of a conventional coal-fired unit i, the unit gas production cost of a natural gas source omega and the unit gas consumption cost of a natural gas storage device s, and the units are $/MBtu, $/kcf and $/kcf; a is_Gi、b_Gi、c_GiThe cost coefficient of the ith conventional thermal power generating unit; p_Gi，tThe output power, MW, of the conventional thermal power generating unit i at the moment t; q_ω，tThe gas production rate of the natural gas source omega at the time t, kcf;

for CO trapped by carbon trapping unit at time t₂Amount captured, kfc;

(3) wind abandon penalty cost:

in the formula, N_WThe number of wind power plants; cw is a wind abandon punishment cost coefficient, $ MWh; p_w，tThe actual output value, MW, of the wind power plant in the time period t is obtained; and P' w and t are output predicted values, MW, of the wind power plant in the t period.

3. The carbon capture-considered low-carbon optimal scheduling method for the electricity-gas integrated energy system according to claim 1, wherein the power network constraints comprise power balance constraints, rotating standby constraints, unit operation constraints and grid operation safety and reliability constraints; the method specifically comprises the following steps:

1) power balance constraint

In the formula, A_b(.)Representing an incidence matrix of a fossil fuel unit, a wind power plant, an electric-to-gas device and a power transmission line which are associated with a power grid node b; n is a radical of_FU、N_W、N_PtG、N_TLThe total number of fossil fuel units, wind power plants, power-to-gas equipment and power transmission lines is respectively;

power, MW, input to the electric gas-to-gas device; p_ED，b，tRepresents the electrical load at node b at time t, MW; PL_l，tThe transmission power of the transmission line l at the moment t, MW;

2) rotational back-up restraint

wind power output constraint:

0≤P_w，t≤P′_w，t(7)

output constraint of fossil fuel units:

τ_i，tP_i，min≤P_i，t≤τ_i，tP_i，max(8)

third, climbing speed constraint:

in the formula, S_up，i、S_dn，iRespectively representing the upward and downward climbing rates, MW, of the fossil fuel unit i;P_i，t+1the output power, MW, of the fossil fuel unit i at the moment t + 1; tau is_i，t+1The variable is 0-1 and represents the start-stop state of the fossil fuel unit i at the moment of t + 1;

and fourthly, constraint of minimum start-up and shut-down time:

in the formula (I), the compound is shown in the specification,

respectively representing the number h of the continuous startup and shutdown time periods of the fossil fuel unit i in the t-1 period; tau is_i，t-1The variable is 0-1 and represents the start-stop state of the fossil fuel unit i at the time t-1;

energy consumption constraint of starting and stopping

4) power grid operation safety and reliability constraint

PL_l，t＝(π_l1，t-π_l2，t)/x_l(12)

In the formula, pi_l1，t、π_l2，tThe voltage phase angle values, rad, of the head end and the tail end of the power transmission line l at the time t are respectively; x is the number of_lIs the reactance of the line lValue, p.u.;

4. The carbon capture-considered low-carbon optimal scheduling method for the electricity-gas integrated energy system is characterized in that the natural gas network constraints comprise gas source gas production constraints, natural gas pipeline flow constraints, natural gas storage equipment constraints, node pressure constraints and node supply and demand balance constraints;

1) gas source gas production constraint

Q_ω，min≤Q_ω，t≤Q_ω，max(14)

2) natural gas pipeline flow restriction

in the formula, Q_mn，tThe gas flow rate of the natural gas pipeline mn flowing at the time t is kcf/h; sgn (p)_m，t，p_n，t) The direction of gas flow is shown, when the direction is 1, the gas flows from the m node to the n node, and when the direction is-1, the gas flows from the n node to the m node; p is a radical of_m，t、p_n，tPressure values at nodes m and n at the time t, Psig; c_mnIs the pipeline constant;

3) natural gas storage equipment restraint

Expressed as:

in the formula (I), the compound is shown in the specification,

4) nodal pressure constraint

p_m，min≤p_m，t≤p_m，max(18)

5) node supply and demand balance constraints

For natural gas node m, the equilibrium equation is as follows:

5. The carbon capture-considered low-carbon optimal scheduling method for the electricity-gas integrated energy system according to claim 1, wherein the constraints of the electricity-to-gas equipment are as follows:

Expressed as:

in the formula (I), the compound is shown in the specification,

power, MW, for input to the electrical to gas equipment;

high heating value for hydrogen, MBtu/kcf;

in the formula (I), the compound is shown in the specification,

CO consumed for methanation reactions₂Amount, kcf/h;

the amount of methane gas synthesized by methanation reaction is kcf/h;

meanwhile, the heat energy generated by methanation reaction is as follows:

in the formula (I), the compound is shown in the specification,

the recovered thermal power, MW, for the electric gas-converting equipment; Ψ_heatMWh/kcf is the heat recovery factor.

6. The carbon capture-considered low-carbon optimal scheduling method for the electric-gas integrated energy system according to claim 1, wherein the carbon capture system constraints are as follows:

the carbon capture unit operation model is represented as follows:

in the formula, P_cEquivalent output power, MW;

net output power, MW;

for capturing CO₂Required energy consumption, MW; maintenance of energy consumption

Is a fixed value, MW;

energy consumption for operation, MW;

in summary, the net output power of the carbon capture unit is expressed as:

and the net output power meets the output limit constraint:

in the formula (I), the compound is shown in the specification,

respectively, the minimum and maximum net power values allowed to be output by the carbon capture unit.

7. The carbon capture-considered low-carbon optimal scheduling method for the electricity-gas integrated energy system is characterized in that the carbon storage and hydrogen storage equipment constraints are as follows:

1) hydrogen storage apparatus

In the formula (I), the compound is shown in the specification,

the hydrogen flow rate injected for the hydrogen storage device s, kcf/h;

respectively representing the minimum and maximum of the hydrogen storage apparatus sHydrogen storage capacity, kcf;

respectively representing the maximum hydrogen injection and extraction flow rates of the hydrogen storage equipment s, kcf/h; NT is the ending time of a scheduling period, h;

in the formula

2) carbon storage equipment

Expressed as:

in the formula (I), the compound is shown in the specification,

in the formula (I), the compound is shown in the specification,

in the formula (I), the compound is shown in the specification,

8. The carbon capture-containing electro-gas integrated energy system of claim 1.

9. An electronic device comprising a memory, a processor and a computer program stored on the memory and executable on the processor, wherein the processor when executing the program performs the steps of the method for carbon capture-aware low carbon optimal scheduling of an electric-gas integrated energy system according to any one of claims 1 to 7.

10. A non-transitory computer readable storage medium having stored thereon a computer program, wherein the computer program when executed by a processor implements the steps of the carbon capture aware low carbon optimal scheduling method for an electricity-gas integrated energy system according to any of claims 1 to 7.