Optimal scheduling method for integrated energy system considering biogas reforming to produce hydrogen and gas blending with hydrogen

Abstract

This invention proposes an optimized scheduling method for a comprehensive energy system considering biogas reforming for hydrogen production and hydrogen blending with natural gas. The method includes: S1, establishing a comprehensive energy system structure incorporating biogas reforming for hydrogen production and hydrogen blending with natural gas; S2, establishing a model for biogas reforming for hydrogen production, hydrogen-blended gas turbines, and a tiered carbon trading system; S3, establishing an optimized scheduling model for the comprehensive energy system incorporating biogas reforming for hydrogen production; S4, acquiring data on system wind and solar power output, load, and time-of-use electricity prices; and S5, solving the scheduling model in S3 to verify the economic efficiency and low-carbon performance of the biogas reforming for hydrogen production method and analyze the benefits of hydrogen blending combustion. This achieves diversified hydrogen production. A green route for converting biomass energy into hydrogen energy is proposed. Through comparative analysis of hydrogen production energy sources and hydrogen production schemes, the method reduces the purchase of external gas and lowers carbon emissions from biomass-to-thermal energy conversion. This achieves diversified utilization of hydrogen energy and promotes the consumption of wind and solar renewable energy. A tiered carbon trading mechanism is introduced.

Description

Technical Field

[0001] This invention relates to the field of energy management technology, specifically to an optimized scheduling method for a comprehensive energy system that considers hydrogen production from biogas reforming and hydrogen blending from natural gas. Background Technology

[0002] Currently, the mainstream hydrogen production method in my country is natural gas-based hydrogen production, which has the advantages of good economy and low carbon emissions. However, the shortage of natural gas supply limits the further development of this method. At the same time, a large amount of biomass waste resources such as straw have not been developed and utilized. Existing research mostly adopts the method of direct utilization of biomass fuels by biomass gas turbines. For example, the study "Two-stage Optimization Operation of Township Biomass Integrated Energy System Considering Heat Network Losses" analyzes the application benefits of biomass gas turbines in township integrated energy systems. However, the problems of high carbon emissions and low energy utilization efficiency of direct combustion of biomass fuel still need to be improved.

[0003] Regarding the diversified utilization of hydrogen energy, existing technologies focus on using hydrogen fuel cells as a single hydrogen consumer. For example, Chinese patent document CN113098036B describes a method for scheduling hydrogen fuel cells in integrated energy systems. However, hydrogen fuel cells suffer from waste heat during practical use, requiring additional consideration of costly waste heat recovery technologies to achieve higher efficiency. Therefore, researching optimized scheduling methods for integrated energy systems that combine biogas reforming for hydrogen production and gas blending with hydrogen is of great significance for improving the utilization rate of biomass energy and hydrogen energy, realizing the conversion of biomass energy to green hydrogen energy, and accelerating the achievement of dual-carbon goals. Summary of the Invention

[0004] This invention provides an optimized scheduling method for a comprehensive energy system that considers hydrogen production through biogas reforming and hydrogen blending with natural gas. It constructs a combined hydrogen production model using biogas reforming and a hydrogen production model using water electrolysis, ensuring a reliable natural gas supply while achieving combined gas and electricity hydrogen production. The generated hydrogen is blended into the gas turbine at a fixed ratio to achieve economical and low-carbon combustion. A tiered carbon trading mechanism is introduced to analyze the impact of changes in carbon trading parameters on the model's total cost and carbon emissions. A low-carbon economic scheduling model for the comprehensive energy system is established with the minimum daily operating cost as the objective function. The economic and low-carbon benefits of the proposed model are verified through simulation examples.

[0005] To solve the above-mentioned technical problems, the technical solution adopted by the present invention is as follows:

[0006] An optimized scheduling method for a comprehensive energy system considering biogas reforming for hydrogen production and gas blending with hydrogen includes the following steps:

[0007] S1. Based on the biogas reforming hydrogen production process, establish a comprehensive energy system structure that includes biogas reforming hydrogen production and gas blending with hydrogen.

[0008] S2. Establish a model for biogas reforming to produce hydrogen, hydrogen-blended gas turbines, and tiered carbon trading.

[0009] S3. Under the premise of satisfying power balance and equipment constraints, establish an optimized scheduling model for an integrated energy system including biogas reforming for hydrogen production;

[0010] S4. Obtain system wind and solar power output, load, and time-of-use electricity price data;

[0011] S5. Solve the scheduling model in S3 to verify the economic efficiency and low carbon emissions of the biogas reforming hydrogen production method, and analyze the benefits of hydrogen-blended combustion.

[0012] The aforementioned S1 is an integrated energy system structure that includes biogas reforming for hydrogen production and gas blending for hydrogen production. The system's energy sources include wind power, photovoltaic power, biomass biogas, purchased electricity, and purchased gas. The conversion equipment includes an electrolyzer, a gas turbine, a hydrogen fuel cell, and an electric boiler. The energy storage equipment includes electrical storage, thermal storage, and hydrogen storage. The biogas reforming for hydrogen production equipment includes a biogas pressure swing adsorption purification device and a steam methane reforming for hydrogen production device.

[0013] The process of establishing the biogas reforming hydrogen production model in S2 described above is as follows:

[0014] Biogas produced by pressure swing adsorption (PSA) is supplied in combination with purchased natural gas, and the separated and purified carbon dioxide is stored on-site. The biogas PSA purification model is as follows:

[0015]

[0016] In the formula: η represents the biogas production during time period t. MG For straw utilization rate, E MG As a gas-producing factor, The mass of biomass straw used during time period t; The biogas production at time t. This is the CH4 production coefficient. This refers to the percentage of CH4 content in biogas. This represents the amount of CO2 stored during time period t. This represents the CO2 emissions during time period t. This represents the ratio of CO2 to CH4 content in biogas. δ is the carbon dioxide loss coefficient, and δ is the CO2 volume conversion coefficient; The power consumption during time period t. The power consumption coefficient of the pressure swing adsorption (PSA) equipment; This represents the upper limit for biogas production. The upper and lower limits of the ramp rate for pressure swing adsorption equipment;

[0017] The natural gas required for steam methane reforming to produce hydrogen is met by biogas and purchased natural gas; the steam methane reforming hydrogen production model is as follows:

[0018]

[0019] In the formula: The hydrogen production during time period t. q represents the gas-to-hydrogen conversion efficiency of a steam methane reforming unit. G It is a low-calorific-value natural gas. Hydrogen has a low calorific value. This represents the gas consumption during time period t. The power consumption during time period t. The power consumption coefficient of the steam methane reforming unit; This represents the CO2 emissions during time period t. The carbon emission coefficient of the steam methane reforming equipment; This represents the upper limit of hydrogen production for steam methane reforming equipment.

[0020] The process of establishing the hydrogen-infused gas turbine model in S2 described above is as follows:

[0021] The hydrogen-blended gas turbine model is as follows:

[0022]

[0023] In the formula: The electrical and thermal power output of the gas turbine during time period t. Let be the volume of natural gas and hydrogen consumed by the gas turbine during time period t. To improve the electrical and thermal efficiency of the gas turbine output; This refers to the hydrogen blending ratio in the gas turbine. This is the upper limit of the electrical output power of the gas turbine; These represent the upper and lower limits of the gas turbine's ramp power.

[0024] The process of establishing the S2 tiered carbon trading model described above is as follows:

[0025] The tiered carbon trading system consists of two parts: carbon trading allowances and carbon emissions. The formulas for calculating carbon trading allowances and carbon emissions are as follows:

[0026]

[0027] In the formula: For carbon trading quotas and carbon emissions during period t, This represents the actual carbon emissions generated during carbon trading in time period t. Carbon emission allowances and carbon emissions per unit of electricity purchased. Carbon emission allowances and carbon emissions per unit of electricity generated by a hydrogen-blended gas turbine. Carbon emission allowance and carbon emissions per unit heat production power of hydrogen-blended gas turbine;

[0028] The calculation formula for the tiered carbon trading mechanism is as follows:

[0029]

[0030] In the formula: Let t be the tiered carbon trading cost for period t, χ be the benchmark value, l be the interval length, and θ be the price growth rate.

[0031] The process of establishing the integrated energy system optimization scheduling model for hydrogen production via biogas reforming in S3 mentioned above is as follows:

[0032] objective function

[0033] A comprehensive energy system model for hydrogen production through biogas reforming and hydrogen blending with natural gas achieves the lowest total cost while satisfying power balance and equipment constraints; the objective function is as follows:

[0034] minC=C WA +C BUY +C JG +C CT +C C +C O ;

[0035] In the formula: C represents the total daily operating cost of the integrated energy system including biogas reforming for hydrogen production; C WA To avoid the cost of abandoning wind and solar power; C BUY Energy purchase cost; C JG For straw costs; C CT For carbon trading costs; C C Cost of carbon sequestration for pressure swing adsorption (PSA) equipment; C O The operating and maintenance costs for each unit are represented by the following expressions:

[0036]

[0037] In the formula: For the curtailed wind and solar power during time period t, p WA p VA The unit price of abandoned wind and solar power; The power and gas purchased during time period t. Time-of-use electricity and gas pricing; p JG The price of straw is set at 350 yuan / ton; p C The unit price for carbon sequestration is 30 yuan / t; i∈{CHP,EB,SMR,ET,HFC,PSA,ES,TS,HS,W,V}. p is the output power of device i during time period t. i The unit price for the operation and maintenance of equipment i.

[0038] The constraints of the integrated energy system optimization scheduling model for hydrogen production via biogas reforming in S3 mentioned above are as follows:

[0039] Electricity, heat, hydrogen, and gas power balance:

[0040]

[0041] In the formula: The on-grid power of wind power and photovoltaic units during time period t; The system's electricity, heat, and natural gas loads during time period t; To determine the electrical and thermal power generated by the hydrogen fuel cell device during time period t, Let t be the volume of hydrogen consumed by the hydrogen fuel cell device during time period t; The power consumption and heat output of the electric boiler equipment during time period t; The power consumption of the water electrolysis equipment during time period t. The hydrogen production of the water electrolysis equipment during time period t; The charging and discharging power of energy storage and thermal storage equipment during time period t. The charging and discharging power of the thermal storage equipment during time period t. The hydrogen storage device represents the volume of hydrogen absorbed and released during time period t; energy storage model constraints:

[0042]

[0043] In the formula: The capacity of the energy storage device during time period t. These are the upper and lower limits of the capacity of energy storage devices; For energy storage and thermal storage equipment, these are the upper and lower limits of charging and discharging power; for hydrogen storage equipment, they are the upper and lower limits of the volume of hydrogen absorbed and released. The capacity of the energy storage device during the initial and final periods;

[0044] Power output constraints of wind and solar turbines:

[0045]

[0046] In the formula: This refers to the electrical output power of wind turbines and photovoltaic units during time period t.

[0047] This invention provides an optimized scheduling method for a comprehensive energy system considering biogas reforming for hydrogen production and gas-blended hydrogen production. First, a biogas reforming hydrogen production model is constructed to meet natural gas load requirements while simultaneously achieving hydrogen production from biogas. Second, the effects of biogas reforming for hydrogen production on system economy and low-carbon emissions are explored by combining water electrolysis and hydrogen produced from biogas reforming. Then, the generated hydrogen is supplied to hydrogen fuel cells and hydrogen-blended gas turbines, and a tiered carbon trading mechanism is introduced to limit system carbon emissions. Finally, simulation analysis is conducted under four different scenarios with the goal of minimizing total daily operating cost. The method offers the following advantages:

[0048] 1) Achieving diversified hydrogen production. A green route for converting biomass energy into hydrogen energy is proposed. Through comparative analysis of hydrogen production energy sources and hydrogen production schemes, the project reduces the need for external gas purchases and lowers carbon emissions from biomass-to-thermal energy conversion. The biogas reforming hydrogen production scheme, when applied to integrated energy systems, can further optimize system scheduling.

[0049] 2) Achieve diversified utilization of hydrogen energy. Hydrogen produced by combined water electrolysis can be supplied to hydrogen fuel cells and gas turbines, realizing the conversion of hydrogen energy into electricity and heat. Incorporating hydrogen into gas turbines in a certain proportion can further reduce natural gas consumption, while the utilization of hydrogen can promote the system's absorption of more wind and solar renewable energy.

[0050] 3) It promotes the consumption of wind and solar renewable energy. The increased proportion of hydrogen blending in gas turbines has boosted hydrogen usage, and the increased hydrogen production from water electrolysis has reduced wind and solar curtailment. Compared to single hydrogen sources, the application of biogas reforming for hydrogen production improves system scheduling flexibility.

[0051] 4) The introduction of a tiered carbon trading mechanism further limits carbon emissions generated during biomass utilization. Tiered carbon trading consists of two parts: carbon trading quotas and carbon emissions. The actual carbon emissions are calculated by considering the total carbon emissions generated throughout the entire biomass utilization process. Different carbon emission levels fall within different ranges, resulting in different carbon trading costs, thus limiting actual carbon emissions and achieving the green and low-carbon use of biomass. Attached Figure Description

[0052] The present invention will be further described below with reference to the accompanying drawings and embodiments:

[0053] Figure 1 This is a schematic diagram of the hydrogen production process involving biogas reforming according to the present invention;

[0054] Figure 2 This is a schematic diagram of the integrated energy system for hydrogen production via biogas reforming according to the present invention;

[0055] Figure 3 This is a schematic diagram of wind power and solar power output;

[0056] Figure 4 This is a schematic diagram of the power of electrical, heat, and gas loads;

[0057] Figure 5 This is a schematic diagram of power dispatching;

[0058] Figure 6 This is a schematic diagram of thermal power scheduling;

[0059] Figure 7 This is a schematic diagram of hydrogen distribution;

[0060] Figure 8 This is a diagram of natural gas dispatching;

[0061] Figure 9 This is a diagram showing the total cost and carbon emissions under different hydrogen doping ratios. Detailed Implementation

[0062] To make the objectives, technical solutions, and advantages of this invention clearer, the following will describe the specific technical solutions of this invention systematically and completely in conjunction with the accompanying drawings provided by this invention. Obviously, the described embodiments are only some embodiments of this invention, not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention.

[0063] Example 1:

[0064] An optimized scheduling method for a comprehensive energy system considering biogas reforming for hydrogen production and gas blending with hydrogen includes the following steps:

[0065] S1. Based on the biogas reforming hydrogen production process, establish a comprehensive energy system structure that includes biogas reforming hydrogen production and gas blending with hydrogen.

[0066] S2. Establish a model for biogas reforming to produce hydrogen, hydrogen-blended gas turbines, and tiered carbon trading.

[0067] S3. Under the premise of satisfying power balance and equipment constraints, establish an optimized scheduling model for an integrated energy system including biogas reforming for hydrogen production;

[0068] S4. Obtain system wind and solar power output, load, and time-of-use electricity price data;

[0069] S5. Solve the scheduling model in S3 to verify the economic efficiency and low carbon emissions of the biogas reforming hydrogen production method, and analyze the benefits of hydrogen-blended combustion.

[0070] Biogas reforming hydrogen production process

[0071] The biogas reforming hydrogen production process includes three steps: anaerobic fermentation to produce biogas, biogas pressure swing adsorption purification, and steam methane reforming to produce hydrogen. The process flow is as follows: Figure 1 As shown:

[0072] Anaerobic fermentation is a common method for biogas production, and the resulting syngas typically contains 55% methane and 45% carbon dioxide. Pressure swing adsorption (PSA) is an important method for biogas purification; compared to conventional PSA units, second-order PSA can increase the purity of both carbon dioxide and methane to over 99%. High-purity methane is then purified to hydrogen with a purity of up to 99% through steam methane reforming and PSA purification.

[0073] Integrated energy system structure including biogas reforming for hydrogen production

[0074] The integrated energy system structure includes biogas reforming for hydrogen production and gas blending for hydrogen production. The energy sources of the system include wind power, photovoltaic power, biomass biogas, purchased electricity, and purchased gas. The conversion equipment includes electrolyzers, gas turbines, hydrogen fuel cells, and electric boilers. The energy storage equipment includes electric storage, thermal storage, and hydrogen storage. The biogas reforming for hydrogen production equipment includes biogas pressure swing adsorption purification equipment and steam methane reforming for hydrogen production equipment.

[0075] Working principle

[0076] Biogas reforming hydrogen production model

[0077] Biogas produced by pressure swing adsorption (PSA) is supplied in combination with purchased natural gas, and the separated and purified carbon dioxide is stored on-site. The biogas PSA purification model is as follows:

[0078]

[0079] In the formula: η represents the biogas production during time period t. MG For straw utilization rate, E MG As a gas-producing factor, The mass of biomass straw used during time period t; The biogas production at time t. This is the CH4 production coefficient. This refers to the percentage of CH4 content in biogas. This represents the amount of CO2 stored during time period t. This represents the CO2 emissions during time period t. This represents the ratio of CO2 to CH4 content in biogas. δ is the carbon dioxide loss coefficient, and δ is the CO2 volume conversion coefficient; The power consumption during time period t. The power consumption coefficient of the pressure swing adsorption (PSA) equipment; This represents the upper limit for biogas production. The upper and lower limits of the ramp rate for pressure swing adsorption equipment;

[0080] The natural gas required for steam methane reforming to produce hydrogen is met by biogas and purchased natural gas; the steam methane reforming hydrogen production model is as follows:

[0081]

[0082] In the formula: The hydrogen production during time period t. q represents the gas-to-hydrogen conversion efficiency of a steam methane reforming unit. G It is a low-calorific-value natural gas. Hydrogen has a low calorific value. This represents the gas consumption during time period t. The power consumption during time period t. The power consumption coefficient of the steam methane reforming unit; This represents the CO2 emissions during time period t. The carbon emission coefficient of the steam methane reforming equipment; This represents the upper limit of hydrogen production for steam methane reforming equipment.

[0083] Gas turbine hydrogen incorporation model

[0084] To further reduce system carbon emissions, this paper employs a hydrogen-blended gas turbine to achieve low-carbon combustion of natural gas. Research shows that the gas turbine can operate safely and stably with a hydrogen blending ratio below 20%. The hydrogen-blended gas turbine model is as follows:

[0085]

[0086] In the formula: The electrical and thermal power output of the gas turbine during time period t. Let be the volume of natural gas and hydrogen consumed by the gas turbine during time period t. To improve the electrical and thermal efficiency of the gas turbine output; This refers to the hydrogen blending ratio in the gas turbine. This is the upper limit of the electrical output power of the gas turbine; These represent the upper and lower limits of the gas turbine's ramp power.

[0087] Tiered carbon trading model

[0088] The tiered carbon trading system consists of two parts: carbon trading allowances and carbon emissions. The formulas for calculating carbon trading allowances and carbon emissions are as follows:

[0089]

[0090] In the formula: For carbon trading quotas and carbon emissions during period t, Q t b This represents the actual carbon emissions generated during carbon trading in time period t. Carbon emission allowances and carbon emissions per unit of electricity purchased. Carbon emission allowances and carbon emissions per unit of electricity generated by a hydrogen-blended gas turbine. Carbon emission allowance and carbon emissions per unit heat production power of hydrogen-blended gas turbine;

[0091] The tiered carbon trading mechanism divides the difference between actual carbon emissions and carbon trading allowances into multiple price ranges, making it more effective in limiting carbon emissions compared to ordinary carbon trading. The calculation formula is as follows:

[0092]

[0093] In the formula: Let t be the tiered carbon trading cost for period t, χ be the benchmark value, l be the interval length, and θ be the price growth rate.

[0094] Optimal scheduling model for integrated energy systems including biogas reforming for hydrogen production

[0095] objective function

[0096] The proposed integrated energy system model for biogas reforming to produce hydrogen and gas blending with hydrogen achieves the lowest total cost while satisfying power balance and equipment constraints; the objective function is as follows:

[0097] minC=C WA +C BUY +C JG +C CT +C C +C O ;

[0098] In the formula: C represents the total daily operating cost of the integrated energy system including biogas reforming for hydrogen production; C WA To avoid the cost of abandoning wind and solar power; C BUY Energy purchase cost; C JG For straw costs; C CT For carbon trading costs; C C Cost of carbon sequestration for pressure swing adsorption (PSA) equipment; C O The operating and maintenance costs for each unit are represented by the following expressions:

[0099]

[0100] In the formula: For the curtailed wind and solar power during time period t, p WA p VA The unit price of abandoned wind and solar power; The power and gas purchased during time period t. Time-of-use electricity and gas pricing; p JG The price of straw is set at 350 yuan / ton; p C The unit price for carbon sequestration is 30 yuan / t; i∈{CHP,EB,SMR,ET,HFC,PSA,ES,TS,HS,W,V}. p is the output power of device i during time period t. i The unit price for the operation and maintenance of equipment i.

[0101] The constraints are:

[0102] Electricity, heat, hydrogen, and gas power balance:

[0103]

[0104] In the formula: The on-grid power of wind power and photovoltaic units during time period t; The system's electricity, heat, and natural gas loads during time period t; To determine the electrical and thermal power generated by the hydrogen fuel cell device during time period t, Let t be the volume of hydrogen consumed by the hydrogen fuel cell device during time period t; The power consumption and heat output of the electric boiler equipment during time period t; The power consumption of the water electrolysis equipment during time period t. The hydrogen production of the water electrolysis equipment during time period t; The charging and discharging power of energy storage and thermal storage equipment during time period t. The charging and discharging power of the thermal storage equipment during time period t. The hydrogen storage device represents the volume of hydrogen absorbed and released during time period t; energy storage model constraints:

[0105]

[0106] In the formula: The capacity of the energy storage device during time period t. These are the upper and lower limits of the capacity of energy storage devices; For energy storage and thermal storage equipment, these are the upper and lower limits of charging and discharging power; for hydrogen storage equipment, they are the upper and lower limits of the volume of hydrogen absorbed and released. The capacity of the energy storage device during the initial and final periods;

[0107] Power output constraints of wind and solar turbines:

[0108]

[0109] In the formula: This refers to the electrical output power of wind turbines and photovoltaic units during time period t.

[0110] Model Solving and Simulation Analysis

[0111] The low-carbon economic dispatch model for the integrated energy system combining biogas reforming for hydrogen production and gas blending with hydrogen is a mixed-integer linear programming problem, solved using the GUROBI solver on the MATLAB platform. Wind power and solar power output are detailed below. Figure 3 Electricity, heat, and gas loads are listed below. Figure 4 The time-of-use electricity and gas prices are shown in Table 1, and the parameters for the biogas PSA purification and SMR hydrogen production model are shown in Table 2. The unit price for wind and solar curtailment is 400 yuan / MWh; the benchmark value in the tiered carbon trading model is 200 yuan / t, the interval length is 10t, and the price growth rate is 0.3%; the SMR hydrogen production operation and maintenance cost is 0.623 yuan / m³. 3 .

[0112] Simulation Result Analysis

[0113] To verify the economic efficiency and low carbon emissions of the biogas reforming hydrogen production model, four operating scenarios were constructed.

[0114] Scenario 1: All natural gas is supplied by purchasing gas, and hydrogen is produced only through water electrolysis.

[0115] Scenario 2: All natural gas is supplied by gas purchase, and hydrogen is produced through a combination of water electrolysis and steam methane reforming.

[0116] Scenario 3: Natural gas is supplied by a combination of biomass gas supply and gas purchase, and hydrogen is produced only through water electrolysis.

[0117] Scenario 4: Natural gas is supplied by a combination of biomass gas supply and gas purchase, and hydrogen is produced through a combination of water electrolysis and steam methane reforming.

[0118] The scheduling results for the four scenarios are shown in Table 3. As can be seen from the table, Scenario 2 reduces the total cost by 2.53% and carbon emissions by 12.09% compared to Scenario 1, which uses water electrolysis to produce hydrogen alone. Steam methane reforming can broaden the system's hydrogen source channels, enabling combined gas and electricity hydrogen production, but it increases the required natural gas volume and raises gas purchase costs. The diversification of hydrogen production pathways reduces the amount of electricity purchased, lowers electricity purchase costs, reduces carbon emissions from electricity purchases, and lowers carbon trading costs.

[0119] Compared to Scenario 1, Scenario 3 reduces total cost by 3.21% but increases carbon emissions by 1.76%. Scenario 3 utilizes biogas produced through biogas purification as another source of natural gas. Compared to purchasing natural gas separately, this reduces gas purchase costs and promotes biomass energy utilization. However, the biogas purification process increases electricity consumption, leading to higher electricity purchase costs and increased output of the gas turbine unit, thus increasing carbon emissions.

[0120] Compared to Scenario 1, Scenario 4 reduces total cost by 5.33% and carbon emissions by 5.17%. While Scenario 4 reduces electricity and gas purchase costs through biogas reforming for hydrogen production, it increases operation and maintenance costs and biomass feedstock costs. Furthermore, the biogas reforming process generates carbon emissions, and since no carbon emission quota is currently defined, carbon trading costs in Scenario 4 are higher than in Scenario 1. In summary, compared to hydrogen production through water electrolysis alone, biogas reforming for hydrogen production improves energy purchase and dispatch flexibility, achieving reductions in total cost and carbon emissions.

[0121] Scheduling Result Analysis

[0122] Figure 5-8 This represents the electrical and thermal power, and the hydrogen and natural gas dispatch results for scenario four. (By...) Figure 5It can be seen that during peak wind and solar power output periods (1:00-5:00, 10:00-15:00, 22:00-24:00), hydrogen production from wind and solar energy is achieved through water electrolysis, biogas pressure swing adsorption purification, and steam methane reforming. Excess electricity is stored in energy storage devices and converted by electric boilers to meet system power balance. During off-peak wind and solar power output periods (6:00-9:00, 17:00-21:00), energy storage devices discharge electricity, and any shortfall is met by purchasing electricity directly. During periods with lower electricity prices (6:00), the cost of hydrogen production through water electrolysis is lower than that through steam methane reforming, so purchasing electricity for hydrogen production is chosen. During periods with higher electricity prices (19:00-21:00), the cost of producing biogas is lower, so biogas reforming is chosen for hydrogen production. The above analysis shows that the biogas reforming hydrogen production model has good economic efficiency in hydrogen production.

[0123] Depend on Figure 6 It can be seen that the heat load is supplied by the gas turbine, electric boiler equipment, and hydrogen fuel cell equipment, with any shortfall or surplus met by thermal storage equipment. The electric boiler equipment decouples the gas turbine from the thermoelectric system, and the use of hydrogen fuel cell equipment realizes the conversion of hydrogen energy into thermal energy.

[0124] Depend on Figure 7 It is known that during periods of higher electricity prices (7:00-9:00 and 16:00-21:00), when hydrogen production through water electrolysis cannot meet the demand, steam methane reforming is a more cost-effective option for hydrogen production. The supplied hydrogen is prioritized to meet the needs of gas turbines, with any surplus being utilized through hydrogen fuel cell equipment and hydrogen storage facilities.

[0125] Depend on Figure 8 It can be seen that during peak wind and solar power output periods, biogas production is chosen to consume the power generated by wind and solar power. When biogas output reaches its maximum capacity, natural gas is purchased to make up the shortfall. During the periods of 6:00, 9:00, 16:00, and 19:00, a certain amount of biogas is prepared to meet the power ramp-up constraints of pressure swing adsorption (PSA). During periods when natural gas prices are relatively high (20:00-21:00), biogas is used to achieve economical gas consumption, with natural gas purchases made to meet any shortfall. During periods when natural gas prices are relatively low (7:00-8:00 and 17:00-18:00), directly purchasing natural gas is more economical.

[0126] 6.4 Hydrogen-doped combustion analysis

[0127] Hydrogen blending in gas turbines can reduce natural gas consumption and enable diversified utilization of hydrogen, but excessive hydrogen demand can burden the system's hydrogen production. Therefore, a sensitivity analysis of the hydrogen blending ratio in gas turbines is necessary to obtain changes in total cost, carbon emissions, and hydrogen production from steam methane reforming, such as... Figure 9 As shown.

[0128] Depend on Figure 9It can be seen that as the proportion of hydrogen blending in gas turbines increases, the total cost and carbon emissions first decrease and then increase, while the amount of hydrogen produced from natural gas continuously increases. Compared to the case without hydrogen blending, moderate hydrogen blending in gas turbines can promote the increase of hydrogen production through water electrolysis and steam methane reforming, while reducing the amount of natural gas required by the gas turbine at various times, achieving economical and low-carbon operation. The increase in hydrogen production through water electrolysis can promote the consumption of wind and solar power, thereby reducing the cost of curtailing wind and solar power; the increase in hydrogen production through steam methane reforming can reduce carbon emissions and energy purchase costs caused by excessive electricity purchases; the reduction in natural gas demand leads to a decrease in the use of biogas, reducing carbon emissions and straw costs. When the hydrogen blending ratio exceeds 0.1%, the demand for hydrogen exceeds the maximum supply. At this point, the energy source required for hydrogen production is met through electricity and gas purchases, thus increasing both the total cost and carbon emissions. In summary, moderate hydrogen blending in gas turbines can promote the consumption of wind and solar power and reduce energy purchase costs; however, excessive hydrogen blending will additionally increase energy purchase costs and carbon emissions, which is not conducive to the economical and low-carbon operation of the system.

Claims

1. A method for optimizing the scheduling of a comprehensive energy system considering biogas reforming for hydrogen production and gas blending with hydrogen, characterized in that, Includes the following steps: S1. Based on the biogas reforming hydrogen production process, establish a comprehensive energy system structure that includes biogas reforming hydrogen production and gas blending with hydrogen. S2. Establish a model for biogas reforming to produce hydrogen, hydrogen-blended gas turbines, and tiered carbon trading. S3. Under the premise of satisfying power balance and equipment constraints, establish an optimized scheduling model for an integrated energy system including biogas reforming for hydrogen production; S4. Obtain system wind and solar power output, load, and time-of-use electricity price data; S5. Solve the scheduling model in S3 to verify the economic efficiency and low carbon emissions of the biogas reforming hydrogen production method, and analyze the benefits of hydrogen-blended combustion. The process of establishing the biogas reforming hydrogen production model in S2 is as follows: Biogas produced by pressure swing adsorption (PSA) is supplied in combination with purchased natural gas, and the separated and purified carbon dioxide is stored on-site. The biogas PSA purification model is as follows: ； Where: For biogas in Production per period To improve straw utilization rate, As a gas-producing factor, For biomass straw in The quality of use during the time period; For biogas in Production per period for Production coefficient For biogas Percentage content; for exist Storage volume for a given period of time for exist Emissions during a specific period For biogas and The ratio of content, The carbon dioxide loss coefficient, for Volume conversion factor; for Power consumption during different time periods The power consumption coefficient of the pressure swing adsorption (PSA) equipment; This represents the upper limit for biogas production. , The upper and lower limits of the ramp rate for pressure swing adsorption equipment; The natural gas required for steam methane reforming to produce hydrogen is met by biogas and purchased natural gas; the steam methane reforming hydrogen production model is as follows: ； Where: For hydrogen in Production per period The efficiency of gas-to-hydrogen conversion in a steam methane reforming unit. It is a low-calorific-value natural gas. Hydrogen has a low calorific value. for Gas consumption per period; for Power consumption during different time periods The power consumption coefficient of the steam methane reforming unit; for exist Periodic emissions; The carbon emission coefficient of the steam methane reforming equipment; This is the upper limit for hydrogen production in a steam methane reforming unit; The process of establishing the hydrogen-doped gas turbine model in S2 is as follows: The hydrogen-blended gas turbine model is as follows: ； Where: , For gas turbines in The electrical and thermal power output during the time period , For gas turbines in The volume of natural gas and hydrogen consumed during a given period. , To improve the electrical and thermal efficiency of the gas turbine output; This refers to the hydrogen blending ratio in the gas turbine. This represents the upper limit of the electrical output power of the gas turbine. , These are the upper and lower limits of the ramp power of the gas turbine; The process of establishing the S2 tiered carbon trading model is as follows: The tiered carbon trading system consists of two parts: carbon trading allowances and carbon emissions. The formulas for calculating carbon trading allowances and carbon emissions are as follows: ； Where: , for Carbon trading quotas and carbon emissions for specific time periods for The actual carbon emissions during the period in which carbon trading takes place. , Carbon emission allowances and carbon emissions per unit of electricity purchased. , Carbon emission allowances and carbon emissions per unit of electricity generated by a hydrogen-blended gas turbine. , Carbon emission allowance and carbon emissions per unit heat production power of hydrogen-blended gas turbine; The calculation formula for the tiered carbon trading mechanism is as follows: ； In the formula: for Time-based tiered carbon trading costs As the baseline value, The interval length is... Price growth rate; The process of establishing the integrated energy system optimization scheduling model for hydrogen production via biogas reforming in S3 is as follows: objective function A comprehensive energy system model for hydrogen production through biogas reforming and hydrogen blending with natural gas achieves the lowest total cost while satisfying power balance and equipment constraints; the objective function is as follows: ； Where: Total daily operating cost of an integrated energy system for hydrogen production from biogas reforming; To avoid the cost of abandoning the scenery; For energy purchase costs; For straw costs; For carbon trading costs; Cost of carbon sequestration in pressure swing adsorption (PSA) equipment; The operating and maintenance costs for each unit are represented by the following expressions: ； Where: , for During certain periods, wind and solar power are curtailed. , The unit price of abandoned wind and solar power; , for Electricity and gas purchase capacity during specific time periods , Time-of-use electricity and gas pricing; The price of straw is set at 350 yuan / ton; The unit price for carbon sequestration is set at 30 yuan / ton; , For equipment exist Output power during the time period For equipment Operation and maintenance unit price; The constraints of the integrated energy system optimization scheduling model for hydrogen production via biogas reforming in S3 are as follows: Electricity, heat, hydrogen, and gas power balance: ； Where: , for The on-grid power of wind and solar power units during different time periods; , , for Electricity, heat, and natural gas loads of the time-of-use system; , For hydrogen fuel cell equipment Electricity and heat production during different time periods For hydrogen fuel cell equipment The volume of hydrogen consumed during a given period; , For electric boiler equipment Power consumption and heat generation during different time periods; For water electrolysis equipment in Power consumption during different time periods For water electrolysis equipment in Hydrogen production during a given period; , For energy storage and thermal storage equipment The charging and discharging power during a given period , For thermal storage equipment in The charging and discharging power during a given period , Hydrogen storage equipment is The volume of hydrogen absorbed and released during a given period; Energy storage model constraints: ； In the formula: For energy storage devices Time slot capacity, , These are the upper and lower limits of the capacity of energy storage devices; , , , For energy storage and thermal storage equipment, these are the upper and lower limits of charging and discharging power; for hydrogen storage equipment, they are the upper and lower limits of the volume of hydrogen absorbed and released. , The capacity of the energy storage device during the initial and final periods; Power output constraints of wind and solar turbines: ； Where: , For wind turbines and photovoltaic units Electric output power during a given time period.

2. The integrated energy system optimization scheduling method considering biogas reforming for hydrogen production and gas blending for hydrogen production, as described in claim 1, is characterized in that, The S1 is an integrated energy system structure containing biogas reforming for hydrogen production and gas blending for hydrogen production. The energy sources of the system include wind power, photovoltaic power, biomass biogas, purchased electricity, and purchased gas. The conversion equipment includes an electrolyzer, a gas turbine, a hydrogen fuel cell, and an electric boiler. The energy storage equipment includes electric storage, thermal storage, and hydrogen storage. The biogas reforming for hydrogen production equipment includes a biogas pressure swing adsorption purification device and a steam methane reforming for hydrogen production device.

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