Mine area comprehensive energy system low-carbon economic dispatching method considering liquid storage type carbon capture power plant

Abstract

The invention discloses a mining area comprehensive energy system low-carbon economic dispatching method considering a liquid storage type carbon capture power plant, and relates to the field of comprehensive energy system optimization dispatching, and the method specifically comprises the following steps: S1) building a liquid storage type carbon capture power plant model according to the operation characteristics of the liquid storage type carbon capture power plant; s2) establishing a two-section type electricity-to-gas conversion model; s3) establishing an associated energy utilization model; and S4) introducing a stepped carbon transaction mechanism, establishing a low-carbon optimization model of the comprehensive energy system in the mining area by taking the minimum total cost of the system as an optimization scheduling target, and determining a scheduling strategy. The low-carbon property and the economical efficiency can be considered, and the problems that in the production process of the mining area comprehensive energy system, a large amount of associated energy is wasted, environment pollution is serious, and wind power integration absorption is difficult are solved.

Description

Technical Field

[0001] The invention discloses a low-carbon economic dispatching method for a mining area integrated energy system considering a liquid storage carbon capture power plant, belonging to the field of integrated energy system optimization dispatching Background Art

[0002] The integrated energy system has the advantages of multi-energy complementarity and energy cascade utilization. A number of integrated energy demonstration projects have been successfully established in Tianjin, Jiangsu, Shanghai and other places, proving that the integrated energy system is an effective solution for energy low-carbon transformation.

[0003] At present, my country will still be in an energy structure dominated by coal for a long time, and the process of coal mining will produce a large amount of associated energy such as ventilation, coal mine gas, and water. According to statistics, the greenhouse effect caused by gas and ventilation emissions in my country is equivalent to about 200 million tons of CO2 each year; the mine water generated in the coal mining process is about 4.5 billion tons, which has caused serious pollution to the environment. Since gas and ventilation contain low concentrations of methane components, which contain rich energy, the temperature of mine water is relatively stable and is an ideal source of heat. Therefore, according to the generation process and enabling characteristics of each associated energy, it can be reasonably utilized to achieve a low-carbon green transformation of the comprehensive energy system in the mining area.

[0004] Existing technologies mostly consider integrated energy systems in industrial park scenarios, but fail to fully integrate the actual production conditions in mining areas. They also mostly consider split-flow carbon capture power plants, whose carbon capture capacity is limited to a certain extent, and cannot fully tap their low-carbon potential in conjunction with wind power. In addition, the single-stage power-to-gas has a relatively single hydrogen energy utilization link and many energy conversion links, which is not conducive to improving energy efficiency. In summary, it is necessary to conduct research on integrated energy systems in mining areas in terms of associated energy utilization, carbon capture power plants, and power-to-gas links. Summary of the invention

[0005] In view of the deficiencies in the prior art, the purpose of the present invention is to provide a low-carbon economic scheduling method for a mining area integrated energy system taking into account a liquid storage carbon capture power plant, so as to solve the problems of a large amount of associated energy waste, serious environmental pollution, and difficulty in connecting wind power to the grid in the production process of the mining area integrated energy system.

[0006] To achieve the above object, the technical solution adopted by the present invention is: a low-carbon economic dispatching method for a mining area integrated energy system considering a liquid storage carbon capture power plant, comprising the following steps:

[0007] S1) Analyze the operating characteristics of the liquid storage carbon capture power plant and establish a liquid storage carbon capture power plant model;

[0008] S2) establishing a two-stage power-to-gas model;

[0009] S3) Establishing an associated energy utilization model;

[0010] S4) Introduce a tiered carbon trading mechanism, take the minimum total system cost as the optimization scheduling goal, establish a low-carbon optimization model for the comprehensive energy system of the mining area, and determine the scheduling strategy.

[0011] The liquid storage carbon capture power plant established in step S1) consists of two parts: a carbon capture power plant and a liquid storage tank, and its contents include:

[0012] The carbon capture power plant operation model is:

[0013]

[0014] Where: P net (t) is the net output power of the carbon capture power plant during period t; P t (t) is the power generation capacity of the coal-fired unit during period t; P base , P ccs (t) are the basic operating energy consumption of carbon capture equipment and the carbon capture energy consumption during period t; E ing (t) is the amount of CO2 being processed in the regeneration tower during period t; ζ is the carbon capture energy consumption coefficient for processing unit CO2; E R,out (t) is the amount of CO2 discharged from the rich liquid tank at time t; λ(t) is the flue gas split ratio at time t; η1 and η2 are the efficiency of CO2 absorption in the absorption tower and regeneration in the regeneration tower, respectively; E t (t) is the amount of CO2 produced by the coal-fired unit at that moment; ε t is the unit carbon emission coefficient of coal-fired units; E capture (t) is the amount of CO2 actually captured by the regeneration tower during period t; γ is the maximum operating coefficient of the regeneration tower;

[0015] The liquid storage tank model is:

[0016]

[0017] Where: E R,out (t) is the amount of CO2 released from the rich liquid tank during period t; V R,out (t) is the volume of rich liquid discharged from the rich liquid tank during period t; M CO2 is the molar mass of CO2; M MEA is the molar mass of the alcohol amine solution; θ is the amount that the regeneration tower can resolve; μ R is the solution concentration; σ R is the density of the solution; V L,in (t), V L,out (t) are the volumes of lean liquid flowing into and out of the lean liquid tank during period t; V R,in (t), V R,out (t) are the volumes of rich liquid flowing into and out of the rich liquid tank during period t; V L (t), VR (t) are the storage volume of the lean liquid tank and the rich liquid tank during time period t; V Lmin 、V Lmax are the minimum and maximum storage volume of the lean liquid tank during period t; V Rmin 、V Rmax They are the minimum and maximum liquid storage volume in the rich liquid tank during period t respectively.

[0018] The associated energy utilization model established in step S3) includes equipment such as a gas turbine, a thermal storage oxidation device, an absorption refrigerator, a waste heat boiler, and a water source heat pump, and its contents include:

[0019] The gas turbine model is:

[0020]

[0021] Where: P GT (t), P GT,e (t), P GT,h (t) is the input equivalent thermal power, output electrical power, and thermal power of the gas turbine during period t; η GT,e , η GT,h is the power generation and thermal efficiency of the gas turbine; H gas is the calorific value of natural gas; L CMM (t) is the gas flow rate during period t; θ gas (t) is the gas concentration in period t; P GT,min , P GT,max are the minimum and maximum output power of the gas turbine respectively; It is the upper and lower limits of the gas turbine climbing;

[0022] The thermal storage oxidation device model is:

[0023]

[0024] Where: P RTO (t), P RTO,e (t), P RTO,h (t) is the input equivalent thermal power, output electrical power and thermal power of the thermal storage oxidation device during period t; η RTO,e , η RTO,h is the power generation and thermal efficiency of the thermal storage oxidation device; L vam (t) is the ventilation flow rate during period t; P RTO,min , P RTO,max are the minimum and maximum output powers of the thermal storage oxidizer, respectively; The upper and lower limits of the thermal storage oxidation device climbing;

[0025] The absorption refrigerator model is:

[0026]

[0027] Where: P AC,in (t), P AC (t) is the input power and output power of the absorption refrigerator during period t; η AC is the cooling efficiency of the absorption chiller; P AC,max is the maximum output power of the absorption chiller; It is the lower and upper limit of the climbing slope of the absorption chiller;

[0028] The waste heat boiler model is:

[0029]

[0030] Where: P WHB (t) is the thermal power output of the waste heat boiler during period t; is the input power of the waste heat boiler during period t; η WHB is the efficiency of the waste heat boiler; P WHB,min , P WHB,max is the minimum and maximum output power of the waste heat boiler; The lower and upper limits of the ramp of the waste heat boiler;

[0031] The water source heat pump model is:

[0032]

[0033] Where: P WSHP (t) is the thermal power output of the water source heat pump during period t; V WSHP (t) is the water inflow during period t; C1 and C2 are the heating fitting coefficients of the water source heat pump; P WSHP,min , P WSHP,max It is the minimum and maximum output power of the water source heat pump; It is the lower and upper limit of the climbing slope of the water source heat pump.

[0034] The total system cost in step S4) is composed of energy purchase cost, energy abandonment penalty cost, equipment operation cost, carbon trading cost, and carbon sequestration cost; the actual carbon emissions of the system are composed of the carbon quota of each unit and carbon emissions, and the carbon trading cost is calculated based on the tiered carbon trading mechanism, which includes:

[0035] The carbon quota model is:

[0036] E CMIES_0 =E ele_0 +E t_0 +E CHP_0 +E GT_0

[0037]

[0038] Where: ECMIES_0 、E ele_0 、E t_0 、E CHP_0 、E GT_0 They are the carbon quotas of the integrated energy system of the mining area, electricity purchased from the upper power grid, coal-fired units, cogeneration units, and gas turbines; E i_0 represents the carbon quota of type i equipment, including power purchase from the upper power grid and coal-fired units; E g_0 represents the carbon quota of g-type equipment, including cogeneration units and gas turbines; P i (t) is the output power of the i-th type of equipment; P g,e (t), P g,h (t) the output electrical power and thermal power of equipment of category g respectively; The carbon quota per unit of electricity supply for the i-th type of equipment; They are the unit power supply and heat supply carbon quotas of the g-type equipment respectively;

[0039] The carbon emission model is:

[0040] E CMIES =E ele +E t +E CHP +E GT +E GB +E RTO -E MR -E seq

[0041]

[0042] Where: E CMIES 、E ele 、E CHP 、E GT 、E GB 、E RTO E is the carbon emissions from the integrated energy system of the mining area, electricity purchased from the upper power grid, cogeneration units, gas turbine units, gas boiler units, and thermal storage oxidation devices; MR 、E seq are the consumption of methane reactor and the amount of CO2 stored in carbon capture unit; E i represents the carbon emissions of type i equipment, including power purchases from the upper power grid and coal-fired units; E g Represents the carbon emissions of g-type equipment, including cogeneration, gas turbines, gas boilers, and thermal storage oxidation devices; P g (t) represents the natural gas power consumed by the g-type equipment; P MR,g (t) is the natural gas power output of the methane reactor in period t; τ is the unit carbon emission coefficient of type i equipment; is the carbon content per unit calorific value of natural gas; is the carbon oxidation rate of natural gas; δ h-e is the thermoelectric conversion coefficient; 44 / 12 is the relative molecular mass ratio of CO2 to carbon; is the gas density of CO2;

[0043] The actual carbon emission model of the system is:

[0044]

[0045] in: is the actual carbon emissions of the integrated energy system in the mining area;

[0046] The total cost of the system is:

[0047]

[0048] Where: C Σ is the total system cost; C buy C is the energy purchase cost; cur C is the penalty cost for energy abandonment; ope The operating cost of each device; For carbon trading costs; for the cost of carbon sequestration;

[0049] The energy purchase cost is:

[0050] C buy =C coal +C ele +C gas

[0051]

[0052] Where: C coal is the coal cost; C ele is the electricity purchase cost; C gas is the gas purchase cost; P ele (t), P gas,buy (t) is the power of electricity and gas purchased in period t; coal is the unit power generation cost of the coal-fired unit; ele ,λ gas is the electricity and gas purchase price corresponding to time period t;

[0053] The energy abandonment penalty cost is:

[0054]

[0055] Among them: c1, c2, c3, c4 correspond to the penalty coefficients of unit abandoned wind power, gas, wind shortage, and water inrush respectively; P c CMM , are the powers of abandoned wind power, gas, wind shortage and water inrush in period t respectively;

[0056] The equipment operation and maintenance costs are:

[0057]

[0058] in: N ccs are the total investment cost and depreciation period of carbon capture equipment respectively; r is the project subsidy rate, which is 5%; V CY 、N CY are the investment cost per unit volume of liquid storage tank, the volume of liquid storage tank, and the depreciation period; α m , P m (t) corresponds to the unit power operation and maintenance cost of equipment m and the output power of equipment m in time period t, m = 1~n, n is the number of operating equipment;

[0059] The carbon trading cost is:

[0060]

[0061] Where: B is the carbon trading benchmark price; T is the carbon trading interval step; θ is the compensation coefficient; υ is the price growth rate;

[0062] The carbon sequestration cost is:

[0063]

[0064] in: is the unit price of carbon sequestration.

[0065] Compared with the existing technology, the advantages of the present invention are: based on the operating characteristics of the liquid storage carbon capture power plant in the carbon capture link, a liquid storage carbon capture power plant model is established; a two-stage power-to-gas model is established to study its potential for coordinated operation with the liquid storage carbon capture power plant in energy conservation and emission reduction, and promoting wind power consumption; at the same time, considering the utilization of associated energy such as gas, lack of wind, and gushing wind, a comprehensive energy system model for the mining area is built, a step-by-step carbon trading mechanism is introduced to constrain the system's carbon emissions, and a low-carbon optimization model for the mining area's comprehensive energy system is established with the minimum total system cost as the optimization scheduling target, which can effectively solve the problems of a large amount of associated energy waste, serious environmental pollution, and difficulty in wind power grid connection and consumption in the production process of the mining area's comprehensive energy system. BRIEF DESCRIPTION OF THE DRAWINGS

[0066] Figure 1 A schematic flow chart of a low-carbon economic dispatching method for a mining area integrated energy system according to an embodiment of the present invention;

[0067] Figure 2A schematic diagram of the structure of a comprehensive energy system for a mining area according to an embodiment of the present invention;

[0068] Figure 3 This is a schematic structural diagram of a liquid storage carbon capture power plant according to an embodiment of the present invention;

[0069] Figure 4 (a) Figure 4 (b) Figure 4 (c) Figure 4 (d) is a schematic diagram of the optimization scheduling results of electricity, heat, cooling and hydrogen power according to an embodiment of the present invention;

[0070] Figure 5 The CO2 distribution in each carbon capture link of the embodiment of the present invention;

[0071] Figure 6 A schematic diagram of wind power output and electricity, heat and cooling load requirements of a mining area comprehensive energy system according to an embodiment of the present invention;

[0072] Figure 7 (a) Figure 7 (b) Figure 7 (c) is a schematic diagram of gas and its methane concentration, ventilation air and its methane concentration, and water inflow on a typical day in the integrated energy system of a mining area according to an embodiment of the present invention. DETAILED DESCRIPTION

[0073] In order to more clearly explain the objectives, technical solutions and advantages of the embodiments of the present invention, the following content will combine specific examples to make a detailed and complete description of the technical solutions of the present invention. It should be noted that the examples described here only represent some application scenarios of the present invention and do not cover all possible situations. According to the examples provided by the present invention, all other application examples that can be derived by ordinary technicians in this field without performing innovative work should be regarded as content within the protection scope of the present invention.

[0074] The present invention provides a low-carbon economic dispatching method for a mining area integrated energy system considering a liquid storage carbon capture power plant, comprising the following steps:

[0075] S1) Analyze the operating characteristics of the liquid storage carbon capture power plant and establish a liquid storage carbon capture power plant model;

[0076] S2) establishing a two-stage power-to-gas model;

[0077] S3) Establishing an associated energy utilization model;

[0078] S4) Introduce a tiered carbon trading mechanism, take the minimum total system cost as the optimization scheduling goal, establish a low-carbon optimization model for the comprehensive energy system of the mining area, and determine the scheduling strategy.

[0079] The step S1) analyzes the operating characteristics of the liquid storage carbon capture power plant and establishes a liquid storage carbon capture power plant model. The content includes: the traditional split-flow carbon capture system does not include two liquid storage tanks, and its working process is: the flue gas bypass device can adjust the flue gas diversion ratio entering the carbon capture system, and the part that does not enter is directly discharged into the atmosphere. After CO2 enters the absorption tower, it dissolves in the alcohol amine solution therein to form a rich liquid, and then flows into the regeneration tower. The regeneration tower absorbs the hot steam generated on the power generation side and continuously heats it, so that CO2 and the alcohol amine solution are separated again (the carbon capture capacity of the carbon capture is subject to the maximum operating state of the regeneration tower), and then compressed and stored for use. The separated alcohol amine solution is a lean liquid, which flows back into the absorption tower, and this cycle repeats;

[0080] The liquid storage carbon capture system installs two liquid storage tanks between the absorption tower and the regeneration tower. The solution flow rate of the liquid storage tank can be changed to adjust the amount of CO2 treated by the regeneration tower, thereby achieving decoupling of the carbon capture link. When the load is at a peak, the liquid storage carbon capture power plant can reduce the flow in and out of the rich liquid tank and store the CO2 diverted by the flue gas diversion device, thereby reducing the carbon capture energy consumption of the carbon capture system and increasing the net output of the unit; when the load is at a low point, the CO2 stored in the rich liquid tank is released to increase the carbon capture energy consumption of the system, reduce the net output of the unit, and increase the grid-connected space for wind power;

[0081] The carbon capture power plant operation model is:

[0082]

[0083] Where: P net (t) is the net output power of the carbon capture power plant during period t; P t (t) is the power generation capacity of the coal-fired unit during period t; P base , P ccs (t) are the basic operating energy consumption of carbon capture equipment and the carbon capture energy consumption during period t; E ing (t) is the amount of CO2 being processed in the regeneration tower during period t; ζ is the carbon capture energy consumption coefficient for processing unit CO2; E R,out (t) is the amount of CO2 discharged from the rich liquid tank at time t; λ(t) is the flue gas split ratio at time t; η1 and η2 are the efficiency of CO2 absorption in the absorption tower and regeneration in the regeneration tower, respectively; E t (t) is the amount of CO2 produced by the coal-fired unit at that moment; ε t is the unit carbon emission coefficient of coal-fired units; E capture (t) is the amount of CO2 actually captured by the regeneration tower during period t; γ is the maximum operating coefficient of the regeneration tower;

[0084] The liquid storage tank model is:

[0085]

[0086] Where: E R,out (t) is the amount of CO2 released from the rich liquid tank during period t; V R,out (t) is the volume of rich liquid discharged from the rich liquid tank during period t; M CO2 is the molar mass of CO2; M MEA is the molar mass of the alcohol amine solution; θ is the amount that the regeneration tower can resolve; μ R is the solution concentration; σ R is the density of the solution; V L,in (t), V L,out (t) are the volumes of lean liquid flowing into and out of the lean liquid tank during period t; V R,in (t), V R,out (t) are the volumes of rich liquid flowing into and out of the rich liquid tank during period t; V L (t), V R (t) are the storage volume of the lean liquid tank and the rich liquid tank during time period t; V Lmin 、V Lmax are the minimum and maximum storage volume of the lean liquid tank during period t; V Rmin 、V Rmax They are the minimum and maximum liquid storage volume in the rich liquid tank during period t respectively.

[0087] The content of establishing the two-stage power-to-gas model in step S2) includes: the two-stage power-to-gas process, that is, when the wind power generation is high, the electrolyzer can consume excess wind power, and part of the hydrogen generated is used as the hydrogen source of the methane reactor, and the obtained methane is supplied to the gas-consuming unit, and the other part is stored in the hydrogen storage tank, and when the load demand is high, it is supplied to the hydrogen fuel cell;

[0088] The electrolytic cell model is:

[0089]

[0090] in: is the hydrogen power generated by the electrolyzer during period t; η EL is the hydrogen production efficiency of the electrolyzer; P EL,e (t) is the electric power input to the electrolytic cell during period t; is the minimum and maximum output power of the electrolyzer; The upper and lower limits of the electrolytic cell’s climbing slope;

[0091] The methane reactor model is:

[0092]

[0093] Where: P MR,g (t) is the natural gas power output of the methane reactor during period t; is the hydrogen power input to the methane reactor during period t; η MR is the conversion efficiency of the methane reactor; are the minimum and maximum input power of the methane reactor; is the lower and upper limits of the climbing slope of the methane reactor;

[0094] The hydrogen storage tank model is:

[0095]

[0096] in: is the hydrogen storage capacity of the hydrogen storage tank during period t; It is the efficiency of hydrogen storage and release; is the hydrogen storage and release power in period t; is the minimum and maximum hydrogen storage capacity of the hydrogen storage tank; is a binary variable for hydrogen storage and release; The maximum power of single hydrogen storage and release;

[0097] The hydrogen fuel cell model is:

[0098]

[0099] in: P is the hydrogen power input to the hydrogen fuel cell during period t; HFC,e (t), P HFC,h (t) is the electrical and thermal power output of the hydrogen fuel cell during period t; is the electricity and heat generation efficiency of the hydrogen fuel cell; P HFC,min , P HFC,max is the minimum and maximum input power of the hydrogen fuel cell; It is the lower upper limit of the hill climbing capability of hydrogen fuel cells; are the upper and lower limits of the adjustable thermoelectric ratio respectively.

[0100] The content of establishing the associated energy utilization model in step S3) includes: supplying the methane gas obtained by the gas extraction pump to the gas turbine for power generation and heat generation; supplying the exhaust air to the thermal storage oxidation device, releasing heat by the thermal countercurrent oxidation principle, and applying it to the combined heat and power supply, and supplying the heat energy to the absorption refrigerator to supply the cooling load; utilizing the high-temperature waste heat generated by the gas turbine through the waste heat boiler; the mine water has a relatively stable temperature and is an ideal heat source for the water source heat pump, supplying the heat load;

[0101] The gas turbine model is:

[0102]

[0103] Where: P GT (t), P GT,e (t), P GT,h (t) is the input equivalent thermal power, output electrical power, and thermal power of the gas turbine during period t; η GT,e, η GT,h is the power generation and thermal efficiency of the gas turbine; H gas is the calorific value of natural gas; L CMM (t) is the gas flow rate during period t; θ gas (t) is the gas concentration in period t; P GT,min , P GT,max are the minimum and maximum output power of the gas turbine respectively; It is the upper and lower limits of the gas turbine climbing;

[0104] The thermal storage oxidation device model is:

[0105]

[0106] Where: P RTO (t), P RTO,e (t), P RTO,h (t) is the input equivalent thermal power, output electrical power and thermal power of the thermal storage oxidation device during period t; η RTO,e , η RTO,h is the power generation and thermal efficiency of the thermal storage oxidation device; L vam (t) is the ventilation flow rate during period t; P RTO,min , P RTO,max are the minimum and maximum output powers of the thermal storage oxidizer, respectively; The upper and lower limits of the thermal storage oxidation device climbing;

[0107] The absorption refrigerator model is:

[0108]

[0109] Where: P AC,in (t), P AC (t) is the input power and output power of the absorption refrigerator during period t; η AC is the cooling efficiency of the absorption chiller; P AC,max is the maximum output power of the absorption chiller; It is the lower and upper limit of the climbing slope of the absorption chiller;

[0110] The waste heat boiler model is:

[0111]

[0112] Where: P WHB (t) is the thermal power output of the waste heat boiler during period t; is the input power of the waste heat boiler during period t; η WHB is the efficiency of the waste heat boiler; P WHB,min , P WHB,max is the minimum and maximum output power of the waste heat boiler; The lower and upper limits of the ramp of the waste heat boiler;

[0113] The water source heat pump model is:

[0114]

[0115] Where: P WSHP (t) is the thermal power output of the water source heat pump during period t; V WSHP (t) is the water inflow during period t; C1 and C2 are the heating fitting coefficients of the water source heat pump; P WSHP,min , P WSHP,max It is the minimum and maximum output power of the water source heat pump; It is the lower and upper limit of the water source heat pump’s climbing slope;

[0116] The equipment model of the integrated energy system in the mining area also includes a wind power operation model, a gas boiler model, a cogeneration unit model, an electric refrigerator model, and a heat storage tank model, and its contents include:

[0117] The wind power operation model is:

[0118] 0≤P wind (t)P wind,pre (t)

[0119] Where: P wind (t) is the actual utilization value of wind power in period t; P wind,pre (t) is the wind power forecast value in period t;

[0120] The gas boiler model is:

[0121]

[0122] Where: P GB (t) is the thermal power output of the gas boiler during period t; is the gas input power of the gas boiler during period t; η GB is the efficiency of the gas boiler; P GB,max is the maximum output power of the gas boiler; It is the lower and upper limit of the climbing slope of the gas boiler;

[0123] The cogeneration unit model is:

[0124]

[0125] Where: P CHP,g (t) is the gas input power of the cogeneration unit during period t; P CHP,e (t), P CHP,h (t) is the output power and thermal power of the cogeneration unit during period t; η CHP is the energy conversion efficiency of the cogeneration unit; PCHP,max is the maximum input power of the cogeneration unit; It is the lower and upper limit of the ramp rate of the cogeneration unit; The lower and upper limits of the adjustable heat-to-electricity ratio of the cogeneration unit;

[0126] The electric refrigerator model is:

[0127]

[0128] Where: P EC,e (t), P EC (t) is the input power and output power of the electric refrigerator during period t; η EC is the cooling efficiency of the electric refrigerator; P EC,max is the maximum output power of the electric refrigerator; It is the lower and upper limit of the climbing slope of the electric refrigerator;

[0129] The thermal storage tank model is:

[0130]

[0131] Where: V HS (t) is the heat storage capacity of the heat storage tank during period t; It is the efficiency of heat storage and release; is the heat storage and release power in period t; is the minimum and maximum heat storage capacity of the heat storage tank; is a binary variable for heat storage and heat release; It is the maximum power of single heat storage and release.

[0132] The step S4) introduces a stepped carbon trading mechanism, takes the minimum total system cost as the optimization scheduling target, establishes a low-carbon optimization model for the comprehensive energy system of the mining area, and determines the scheduling strategy, which includes: the total system cost is composed of energy purchase cost, energy abandonment penalty cost, equipment operation cost, carbon trading cost, and carbon sequestration cost; the actual carbon emissions of the system are composed of the carbon quota and carbon emissions of each unit, and the carbon trading cost is calculated based on the stepped carbon trading mechanism;

[0133] The carbon quota model is:

[0134] Free carbon quotas are adopted, and it is assumed that the electricity purchased from the power grid comes from thermal power units. The sources of free carbon quotas for the integrated energy system in the mining area mainly include power purchases from the upper power grid, coal-fired units, cogeneration, and gas turbines.

[0135] E CMIES_0 =E ele_0 +E t_0 +E CHP_0 +E GT_0

[0136]

[0137] Where: E CMIES_0 、E ele_0 、E t_0 、E CHP_0 、E GT_0 They are the carbon quotas of the integrated energy system of the mining area, electricity purchased from the upper power grid, coal-fired units, cogeneration units, and gas turbines; E i_0 represents the carbon quota of type i equipment, including power purchase from the upper power grid and coal-fired units; E g_0 represents the carbon quota of g-type equipment, including cogeneration units and gas turbines; P i (t) is the output power of the i-th type of equipment; P g,e (t), P g,h (t) the output electrical power and thermal power of equipment of category g respectively; The carbon quota per unit of electricity supply for the i-th type of equipment; They are the unit power supply and heat supply carbon quotas of the g-type equipment respectively;

[0138] The carbon emission model is:

[0139] E CMIES =E ele +E t +E CHP +E GT +E GB +E RTO -E MR -E seq

[0140]

[0141] Where: E CMIES 、E ele 、E CHP 、E GT 、E GB 、E RTO E is the carbon emissions from the integrated energy system of the mining area, electricity purchased from the upper power grid, cogeneration units, gas turbine units, gas boiler units, and thermal storage oxidation devices; MR 、E seq are the consumption of methane reactor and the amount of CO2 stored in carbon capture unit; E i represents the carbon emissions of type i equipment, including power purchases from the upper power grid and coal-fired units; E g Represents the carbon emissions of g-type equipment, including cogeneration, gas turbines, gas boilers, and thermal storage oxidation devices; P g (t) represents the natural gas power consumed by the g-type equipment; P MR,g(t) is the natural gas power output of the methane reactor in period t; τ is the unit carbon emission coefficient of type i equipment; is the carbon content per unit calorific value of natural gas; is the carbon oxidation rate of natural gas; δ h-e is the thermoelectric conversion coefficient; 44 / 12 is the relative molecular mass ratio of CO2 to carbon; is the gas density of CO2;

[0142] The actual carbon emission model of the system is:

[0143]

[0144] in: is the actual carbon emissions of the integrated energy system in the mining area;

[0145] The total cost of the system is:

[0146]

[0147] Where: C Σ is the total system cost; C buy C is the energy purchase cost; cur C is the penalty cost for energy abandonment; ope The operating cost of each device; For carbon trading costs; for the cost of carbon sequestration;

[0148] The energy purchase cost is:

[0149] C buy =C coal +C ele +C gas

[0150]

[0151] Where: C coal is the coal cost; C ele is the electricity purchase cost; C gas is the gas purchase cost; P ele (t), P gas,buy (t) is the power of electricity and gas purchased in period t; coal is the unit power generation cost of the coal-fired unit; ele ,λ gas is the electricity and gas purchase price corresponding to time period t;

[0152] The energy abandonment penalty cost is:

[0153]

[0154] Among them: c1, c2, c3, c4 correspond to the penalty coefficients of unit abandoned wind power, gas, wind shortage, and water inrush respectively; P c CMM ,P c VAM (t), are the powers of abandoned wind power, gas, wind shortage and water inrush in period t respectively;

[0155] The equipment operation and maintenance costs are:

[0156]

[0157] in: N ccs are the total investment cost and depreciation period of carbon capture equipment respectively; r is the project subsidy rate, which is 5%; V CY 、N CY are the investment cost per unit volume of liquid storage tank, the volume of liquid storage tank, and the depreciation period; α m , P m (t) corresponds to the unit power operation and maintenance cost of equipment m and the output power of equipment m in time period t, m = 1~n, n is the number of operating equipment;

[0158] The carbon trading cost is:

[0159]

[0160] Where: B is the carbon trading benchmark price, T is the carbon trading interval step, θ is the compensation coefficient, and υ is the price growth rate;

[0161] The carbon sequestration cost is:

[0162]

[0163] in: is the unit price of carbon sequestration.

[0164] In addition, in addition to equipment operation constraints, the system still needs to meet relevant power balance constraints;

[0165] The power constraint balance model is:

[0166] Electrical balance:

[0167] P ele (t)+P net (t)+P Wind (t)+P CHP,e (t)+P GT,e (t)+P HFC,e (t) = P EL (t)+PEC,e (t)+P e,Load (t)

[0168] Where: P e,Load (t) is the electrical load during period t;

[0169] Thermal balance:

[0170]

[0171] Where: P h,Load (t) is the heat load during period t;

[0172] Cold balance:

[0173] P EC (t)+P AC (t) = P c,load (t)

[0174] Where: P c,load (t) is the cooling load during period t;

[0175] Gas balance

[0176] P gas,buy (t)+P MR,g (t) = P CHP,g (t)+P GB,g (t)

[0177] Hydrogen balance

[0178]

[0179] Example

[0180] The Yalmip toolbox is used to build a 24-hour day-ahead optimization scheduling model, and the CPLEX commercial solver is called to solve it. Taking a mining area in the west as an example, different scenarios are set to verify the effectiveness of the proposed low-carbon economic scheduling model of the mining area integrated energy system considering the liquid storage carbon capture system. The specific scenarios are as follows:

[0181] Scenario 1: No associated energy utilization, no carbon capture system, and single-stage power-to-gas conversion;

[0182] Scenario 2: No consideration of associated energy utilization, including split-flow carbon capture and single-stage power-to-gas;

[0183] Scenario 3: No consideration of associated energy utilization, including liquid storage carbon capture and single-stage power-to-gas; Scenario 4: Considering associated energy utilization, including liquid storage carbon capture and single-stage power-to-gas;

[0184] Scenario 5: Consider the utilization of associated energy, including liquid storage carbon capture and two-stage power-to-gas.

[0185] Table 1 shows the system equipment related parameters:

[0186] Table 1

[0187]

[0188] Table 2 shows the relevant parameters of carbon trading:

[0189] Table 2

[0190]

[0191] Table 3 shows the time-of-use electricity price:

[0192] Table 3

[0193] Time Electricity price (yuan / MW) 1:00-7:00、23:00-24:00 380 8:00-11:00、15:00-18:00 680 12:00-14:00、19:00-21:00 1200

[0194] Table 4 shows the optimization scheduling results for each scenario:

[0195] Table 4

[0196]

[0197]

[0198] From Table 4, we can see that:

[0199] Compared with Scenario 1, Scenario 2 has a total system cost reduction of 27,300 yuan, a carbon trading cost reduction of 20,400 yuan, a carbon emission reduction of 19.45 tons, and a wind power consumption rate increase of 97.47%. The reason is that Scenario 2 introduces a split-flow carbon capture power plant and a single-stage power-to-gas conversion on its basis. The power-to-gas equipment can consume surplus wind power, generate hydrogen through an electrolyzer, and combine it with the CO2 captured by the carbon capture power plant through a methane reactor, thereby reducing the system's carbon emissions and increasing wind power access to the grid. However, due to the coupling in the carbon capture link, the system's emission reduction capacity is limited.

[0200] Compared with Scenario 2, Scenario 3 reduces the total system cost by RMB 14,100, earns RMB 8,200 through the carbon trading market, reduces carbon emissions by 168.06 tons, and achieves full absorption of wind power. The reason is that Scenario 3 adds a liquid storage tank on the basis of Scenario 2, which can achieve time shift of carbon capture, further reduce carbon emissions, increase carbon capture energy consumption, and improve wind power absorption.

[0201] Compared with Scenario 3, Scenario 4 reduces the total system cost by RMB 141,400, realizes carbon trading income of RMB 31,400, and reduces carbon emissions by 145.74 tons. The reason is that Scenario 4 considers the use of associated energy on the basis of Scenario 3, which greatly reduces the system's energy purchase cost. The carbon capture power plant can further reduce the net output and increase the carbon capture energy consumption.

[0202] Compared with Scenario 4, Scenario 5 reduces the total system cost by 7,500 yuan, increases carbon income by 3,100 yuan, and reduces carbon emissions by 13.77 tons. The reason is that Scenario 5 establishes a two-stage power-to-gas model based on Scenario 4. During the period of high wind power generation, hydrogen is produced by electrolyzers and stored in hydrogen storage tanks, realizing the arbitrage effect of high generation and low storage. In addition, compared with the methane reactor, hydrogen fuel cells consume hydrogen to produce natural gas to supply cogeneration units and gas boilers, which eliminates the intermediate links to reduce energy loss and does not emit CO2. In summary, compared with Scenario 1, Scenario 5 proposed in this article reduces the total system cost by 33.00%, reduces carbon emissions by 65.74%, and has significant low-carbon economic benefits.

[0203] Analysis of the unit output in scenario 5:

[0204] The results of optimized dispatch of electric power and hydrogen power in scenario 5 are as follows: Figure 4 As shown in (a) and (d), during the period of 1:00-5:00 and 22:00-24:00, which is the peak period of wind power generation, some wind power is not connected to the grid while ensuring the power load demand. The electrolyzer consumes the excess wind power to produce hydrogen, and some of the hydrogen energy is supplied to the hydrogen fuel cell for thermal power production, and some is stored in the hydrogen storage tank to achieve the transfer of wind power, giving full play to its economic benefits of "peak shaving and valley filling". In addition, compared with the direct supply of hydrogen to the hydrogen fuel cell, there are fewer energy conversion links and higher utilization efficiency than the production of natural gas through the methane device and then supplying it to the cogeneration unit. Therefore, H2 is more inclined to be supplied to the hydrogen fuel cell first. The results of thermal power optimization scheduling are shown in Figure 2. Figure 4 As shown in (b), in order to ensure the economic benefits of the system, the system fully utilizes the associated energy to supply heat load, cooperates with the heat storage tank to store heat during the low heat load periods such as 11:00-12:00 and 14:00-15:00, etc., to reduce the waste of heat energy, and releases heat during the heat load peak periods such as 1:00-3:00 and 23:00, etc., to reduce the system's gas purchase cost. The cooling power optimization scheduling results are shown in Figure 4 As shown in (c), the absorption chiller makes full use of the associated energy of exhausted air cooling, and the remaining cooling power is supplied to the system through the power consumption of the electric chiller.

[0205] Analysis of the benefits of liquid storage carbon capture power plants:

[0206] Depend on Figure 5It can be seen that the liquid storage carbon capture power plant can achieve the decoupling of the carbon capture process. The CO2 regenerated by the regeneration tower and the CO2 absorbed by the absorption tower are not equal in value at any time period. In the period of 7:00-21:00, due to the anti-peak regulation characteristics of wind power, the electricity load demand is relatively high at this time. The liquid storage carbon capture power plant will flow the CO2 captured by the absorption tower into the rich liquid tank for storage, thereby reducing the energy consumption of carbon capture and increasing the net output; in the high-generation wind power periods of 1:00-6:00 and 22:00-24:00, the rich liquid tank will release the temporarily stored CO2, and it will flow into the regeneration tower together with the CO2 absorbed by the absorption tower. At this time, the carbon capture energy consumption is greatly improved, and the lower limit of the net output is further reduced compared to the diversion carbon capture. While reducing the system's carbon emissions, it can also provide space for wind power to access the grid.

[0207] Finally, it should be pointed out that the above embodiments are intended to illustrate the technical solutions of the present invention and do not constitute any limitation. Even if the present invention has been described in detail according to the above embodiments, a person skilled in the art should also recognize that the technical solutions described in these embodiments can still be adjusted or replaced with equivalent technical features in part or in whole. Such adjustment or replacement will not cause the essence of the relevant technical solutions to exceed the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A low-carbon economic dispatch method for a mining area integrated energy system considering a liquid storage carbon capture power plant, characterized in that The following steps are involved: S1) Analyze the operating characteristics of the liquid storage carbon capture power plant and establish a liquid storage carbon capture power plant model; S2) establishing a two-stage power-to-gas model; S3) Establishing an associated energy utilization model; S4) Introduce a tiered carbon trading mechanism, take the minimum total system cost as the optimization scheduling goal, establish a low-carbon optimization model for the comprehensive energy system of the mining area, and determine the scheduling strategy.

2. The low-carbon economic dispatching method for the integrated energy system of a mining area considering a liquid storage carbon capture power plant according to claim 1, characterized in that: The liquid storage carbon capture power plant established in step S1) consists of two parts: a carbon capture power plant and a liquid storage tank, and its contents include: The carbon capture power plant operation model is: Where: P net (t) is the net output power of the carbon capture power plant during period t; P t (t) is the power generation capacity of the coal-fired unit during period t; P base , P ccs (t) are the basic operating energy consumption of carbon capture equipment and the carbon capture energy consumption during period t; E ing (t) is the amount of CO2 being processed in the regeneration tower during period t; ζ is the carbon capture energy consumption coefficient for processing unit CO2; E R,out (t) is the amount of CO2 discharged from the rich liquid tank at time t; λ(t) is the flue gas split ratio at time t; η1 and η2 are the efficiency of CO2 absorption in the absorption tower and regeneration in the regeneration tower, respectively; E t (t) is the amount of CO2 produced by the coal-fired unit at that moment; ε t is the unit carbon emission coefficient of coal-fired units; E capture (t) is the amount of CO2 actually captured by the regeneration tower during period t; γ is the maximum operating coefficient of the regeneration tower; The liquid storage tank model is: Where: E R,out (t) is the amount of CO2 released from the rich liquid tank during period t; V R,out (t) is the volume of rich liquid discharged from the rich liquid tank during period t; is the molar mass of CO2; M MEA is the molar mass of the alcohol amine solution; θ is the amount that the regeneration tower can resolve; μ R is the solution concentration; σ R is the density of the solution; V L,in (t), V L,out (t) are the volumes of lean liquid flowing into and out of the lean liquid tank during period t; V R,in (t), V R,out (t) are the volumes of rich liquid flowing into and out of the rich liquid tank during period t; V L (t), V R (t) are the storage volume of the lean liquid tank and the rich liquid tank during time period t; V Lmin 、V Lmax are the minimum and maximum storage volume of the lean liquid tank during period t; V Rmin 、V Rmax They are the minimum and maximum liquid storage volume in the rich liquid tank during period t respectively.

3. A low-carbon economic dispatching method for a mining area integrated energy system considering a liquid storage carbon capture power plant according to claim 1, characterized in that: The associated energy utilization model established in step S3) includes equipment such as a gas turbine, a thermal storage oxidation device, an absorption refrigerator, a waste heat boiler, and a water source heat pump, and its contents include: The gas turbine model is: Where: P GT (t), P GT,e (t), P GT,h (t) is the input equivalent thermal power, output electrical power and thermal power of the gas turbine during period t; η GT,e , η GT,h is the power generation and thermal efficiency of the gas turbine; H gas is the calorific value of natural gas; L CMM (t) is the gas flow rate during period t; θ gas (t) is the gas concentration in period t; P GT,min , P GT,max are the minimum and maximum output power of the gas turbine respectively; It is the upper and lower limits of the gas turbine climbing; The thermal storage oxidation device model is: Where: P RTO (t), P RTO,e (t), P RTO,h (t) is the input equivalent thermal power, output electrical power and thermal power of the thermal storage oxidation device during period t; η RTO,e , η RTO,h is the power generation and thermal efficiency of the thermal storage oxidation device; L vam (t) is the ventilation flow rate during period t; P RTO,min , P RTO,max are the minimum and maximum output powers of the thermal storage oxidizer, respectively; The upper and lower limits of the thermal storage oxidation device climbing; The absorption refrigerator model is: Where: P AC,in (t), P AC (t) is the input power and output power of the absorption refrigerator during period t; η AC is the cooling efficiency of the absorption chiller; P AC,max is the maximum output power of the absorption chiller; It is the lower and upper limit of the climbing slope of the absorption chiller; The waste heat boiler model is: Where: P WHB (t) is the thermal power output of the waste heat boiler during period t; is the input power of the waste heat boiler during period t; η WHB is the efficiency of the waste heat boiler; P WHB,min , P WHB,max is the minimum and maximum output power of the waste heat boiler; The lower and upper limits of the ramp of the waste heat boiler; The water source heat pump model is: Where: P WSHP (t) is the thermal power output of the water source heat pump during period t; V WSHP (t) is the water inflow during period t; C1 and C2 are the heating fitting coefficients of the water source heat pump; P WSHP,min , P WSHP,max is the minimum and maximum output power of the water source heat pump; It is the lower and upper limit of the climbing slope of the water source heat pump.

4. A low-carbon economic dispatching method for a mining area integrated energy system considering a liquid storage carbon capture power plant according to claim 1, characterized in that: The total system cost in step S4) is composed of energy purchase cost, energy abandonment penalty cost, equipment operation cost, carbon trading cost, and carbon sequestration cost; the actual carbon emissions of the system are composed of the carbon quota of each unit and carbon emissions, and the carbon trading cost is calculated based on the tiered carbon trading mechanism, which includes: The carbon quota model is: AND CMIES_0 =And ele_0 +E t_0 +E CHP_0 +E GT_0 Where: E CMIES_0 、E ele_0 、E t_0 、E CHP_0 、E GT_0 They are the carbon quotas of the integrated energy system of the mining area, electricity purchased from the upper power grid, coal-fired units, cogeneration units, and gas turbines; E i_0 represents the carbon quota of type i equipment, including power purchase from the upper power grid and coal-fired units; E g_0 represents the carbon quota of g-type equipment, including cogeneration units and gas turbines; P i (t) is the output power of the i-th type of equipment; P g,e (t), P g,h (t) the output electrical power and thermal power of equipment of category g respectively; The carbon quota per unit of power supply for the i-th type of equipment; They are the unit power supply and heat supply carbon quotas of the g-type equipment respectively; The carbon emission model is: AND CMIES =And ele +E t +E CHP +E GT +E GB +E RTO -AND MR -AND seq Where: E CMIES 、E ele 、E CHP 、E GT 、E GB 、E RTO E is the carbon emissions from the integrated energy system of the mining area, electricity purchased from the upper power grid, cogeneration units, gas turbine units, gas boiler units, and thermal storage oxidation devices; MR 、E seq are the consumption of methane reactor and the amount of CO2 stored in carbon capture unit; E i represents the carbon emissions of type i equipment, including power purchases from the upper power grid and coal-fired units; E g Represents the carbon emissions of g-type equipment, including cogeneration, gas turbines, gas boilers, and thermal storage oxidation devices; P g (t) represents the natural gas power consumed by the g-type equipment; P MR,g (t) is the natural gas power output of the methane reactor in period t; τ is the unit carbon emission coefficient of type i equipment; is the carbon content per unit calorific value of natural gas; is the carbon oxidation rate of natural gas; δ h-e is the thermoelectric conversion coefficient; 44 / 12 is the relative molecular mass ratio of CO2 to carbon; is the gas density of CO2; The actual carbon emission model of the system is: in: is the actual carbon emissions of the integrated energy system in the mining area; The total cost of the system is: Where: C Σ is the total system cost, C buy is the energy purchase cost, C cur is the penalty cost for energy abandonment, C ope is the operating cost of each device, is the carbon trading cost, for the cost of carbon sequestration; The energy purchase cost is: C buy =C coal +C ele +C gas Where: C coal is the coal cost, C ele is the electricity purchase cost, C gas is the gas purchase cost, P ele (t), P gas,buy (t) is the power of electricity and gas purchased in period t; coal is the unit power generation cost of the coal-fired unit, λ ele ,λ gas is the electricity and gas purchase price corresponding to time period t; The penalty cost for energy abandonment is: Among them: c1, c2, c3, c4 correspond to the penalty coefficients of unit abandoned wind power, gas, wind shortage, and water inrush respectively; are the powers of abandoned wind power, gas, wind shortage and water inrush in period t respectively; The equipment operation and maintenance costs are: in: N ccs are the total investment cost and depreciation period of carbon capture equipment respectively; r is the project subsidy rate, which is 5%; V CY 、N CY are the investment cost per unit volume of liquid storage tank, the volume of liquid storage tank, and the depreciation period; α m , P m (t) corresponds to the unit power operation and maintenance cost of equipment m and the output power of equipment m in time period t, m = 1~n, n is the number of operating equipment; The carbon trading cost is: in: is the carbon trading cost, B is the carbon trading benchmark price, T is the carbon trading interval step, θ is the compensation coefficient, and υ is the price growth rate; The carbon sequestration cost is: in: is the unit price of carbon sequestration.

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