An optimization method for improving the thermal utilization of p2g and thermal coupling of carbon capture equipment

Abstract

The application discloses an optimization method for improving P2G heat utilization rate and heat coupling of carbon capture equipment, and comprises the following steps: deducing reaction heat of an electric-to-gas process according to a chemical reaction equation, and optimizing and improving a traditional P2G model; delivering the reaction heat of the P2G deduced in step 1 to a carbon capture equipment, and using the heat to supply the carbon capture, so as to strengthen heat coupling of the P2G and the carbon capture equipment; applying the IP2G model and the carbon capture device to a comprehensive energy system; taking annual operation cost saving rate, primary energy saving amount and carbon dioxide emission reduction as objective functions, taking device configuration of the comprehensive energy system as variables, setting constraint conditions, and adopting a meerkat algorithm as a solving algorithm to perform optimization configuration solving. The application deduces the heat by studying a chemical equation in a reaction process of the P2G, and the application is applied to the comprehensive energy system, so that the energy storage cost performance of the P2G equipment can be improved, the primary energy consumption amount can be reduced, and the annual operation cost can be effectively reduced.

Description

Technical Field

[0001] This invention belongs to the field of energy systems, and specifically relates to an optimized method for improving the thermal efficiency of P2G and the thermal coupling of carbon capture equipment. Background Technology

[0002] Multi-stage energy coupling refers to improving energy efficiency through multi-stage energy utilization within an energy system. Adopting an integrated power-hot water-steam energy system can effectively improve overall energy efficiency. Integrated Energy Systems (IES) improve energy utilization efficiency, but research on IES still has certain limitations. Using power-to-gas (P2G) technology can alleviate the waste of wind and solar energy in IES systems. By adding P2G to IES systems, the power-gas coupling of combined heat and power (CHP) P2G systems can be improved, enhancing system stability and economic efficiency. However, traditional P2G models have limitations, such as low storage efficiency, which limits the energy storage performance of P2G in integrated systems. This leads power generation companies to prefer other energy storage methods. However, P2G can absorb CO2 while storing energy, offering some environmental benefits. If the energy utilization rate of P2G can be improved while considering CO2 absorption, not only reducing CO2 levels but also achieving energy storage functionality, the overall energy storage performance of P2G will be further enhanced.

[0003] Traditional carbon capture (CC) devices typically utilize heat generated by thermal power plants for carbon capture. Studies have shown that the CC process reduces the thermal efficiency of these plants. Considering multi-energy demand response and the electrothermal integration of CC technology can improve the carbon reduction capacity of CC plants. The energy source of a CC plant affects its CC capture cost. Integrated energy systems combining CC plants with power generation-to-grid (P2G) systems have a positive impact on promoting wind power consumption and reducing carbon emissions. Enhancing the energy coupling between P2G and CC plants can reduce the CC capture cost. Previous research has often focused on enhancing the electrical coupling between P2G and CC plants by consuming the electrical energy stored in the P2G. If the previously neglected heat in the P2G can be allocated to the CC plant, achieving thermal coupling between the two, this neglected heat can be utilized more effectively, thus reducing CC capture costs. Summary of the Invention

[0004] To address the above issues, this invention proposes an optimization method that considers the thermal effect of P2G and the thermal coupling between P2G and carbon capture devices. This method derives the heat by studying the chemical equations during the P2G reaction process. When applied to integrated energy systems, this invention can improve the energy storage cost-effectiveness of P2G devices, reduce primary energy consumption, and effectively lower annual operating costs.

[0005] This invention proposes an optimization method that considers the thermal effect of P2G and the thermal coupling between P2G and the carbon capture device. The specific design scheme is as follows:

[0006] Step 1: The heat of reaction for the electro-gas conversion process is derived from the chemical reaction equation, and the traditional P2G model is optimized.

[0007] Step 2: The reaction heat derived from P2G in Step 1 is transferred to the carbon capture device. This heat is used to supply carbon capture and strengthen the thermal coupling between P2G and the carbon capture device.

[0008] Step 3: Apply the improved P2G model and carbon capture device to the integrated energy system;

[0009] Step 4: Using the annual operating cost saving rate, primary energy saving, and carbon dioxide emission reduction as objective functions, and the equipment configuration of the integrated energy system as variables, set constraints and use the honey badger algorithm as the solution algorithm to optimize the configuration.

[0010] In the traditional P2G model, the amount of electrical energy converted into natural gas during P2G energy storage can be calculated as follows:

[0011] F P2G =E P2G ×η P2G,F

[0012] Among them, E P2G It is the electrical energy absorbed by P2G, η P2G,F The natural gas conversion rate of the P2G equipment is F. In this paper, F P2G This refers to the energy generated from natural gas through P2G (Power-to-Gas) equipment, measured in kilowatt-hours (kWh). P2G can convert electrical energy into natural gas, but the heat generated in this process is typically negligible. Therefore, improved P2G (IP2G) increases the utilization efficiency of P2G equipment, reducing this heat Q. P2G This can be derived from the electro-gas conversion reaction equation, which is:

[0013] 4H2+CO2→CH4+2H2O,ΔH=-165.01kJ / mol

[0014] Where ΔH represents the heat absorbed or released in the reaction. A positive ΔH indicates heat absorption, and a negative ΔH indicates heat release. The above formula shows that 165.01 kJ of heat is released for every 1 mol of CH4 produced. The conversion relationship between the yield of P2G per unit time and the exothermic reaction (assuming no branching products are produced during methanation) is as follows:

[0015]

[0016]

[0017] in, These represent the reaction rates of methanation and electro-hydrogen production, respectively. P represents the heat of reaction of P2G methanation. P2G This refers to the operating power of the IP2G device. It is the calorific value of CH4. and These are the densities of methane and hydrogen, respectively. and This indicates the relative molecular mass of methane and hydrogen. This is the proportion of the heat of reaction injected into the heating network; the calculated heat of reaction of IP2G when it absorbs 1MWh of electrical energy is as follows:

[0018]

[0019] Q P2G =E P2G ×η P2G,Q

[0020] In the formula: η P2G,Q The heat conversion rate of the IP2G equipment. Carbon dioxide, as one of the raw materials for the IP2G equipment, needs to be captured and transported to the IP2G via the CCU equipment. The amount of carbon dioxide consumed in this process... The calculation is as follows:

[0021]

[0022] In the formula: The carbon dioxide consumption rate of IP2G is given in this paper. The derivation and η P2G,Q Similarly, the chemical equation for water electrolysis and the law of conservation of energy can be used to calculate... It equals 11.2%.

[0023] Since the unit's cycle thermal efficiency decreases by about 9% when the carbon capture rate is around 90%, IP2G applies the waste heat generated during electrical energy storage to the CCU, thus avoiding the problem of traditional P2G equipment needing to reduce the unit's cycle thermal efficiency for carbon capture during operation. Furthermore, besides capturing the carbon dioxide required for P2G, the excess heat can also be used to capture carbon dioxide generated by other equipment in the system.

[0024] The heat generated by IP2G Q P2G It can be directly used in carbon capture equipment; the heat is used in the carbon capture equipment to capture carbon dioxide. The following can be derived:

[0025]

[0026] and The difference between them is the net carbon capture amount after IP2G is combined with CCU, λ B Given the heat conversion coefficient of P2G, the net carbon capture coefficient per unit of IP2G heating can be derived from the formula above as follows:

[0027]

[0028] In the formula: λ P2G,ccu The unit is kW / kg, and the net carbon capture capacity per unit of IP2G can be calculated as follows:

[0029]

[0030] When IP2G and carbon capture equipment are combined in an integrated energy system, and the system operates on an electricity-driven, heat-driven model, in order to meet electricity demand... E The power generation equipment is divided into three layers. First, the first layer is environmentally friendly but unstable new energy power generation, in this paper referring to solar and wind power. Second, the second layer provides power to the PGU (Power Generation Unit). Finally, the third layer is the power grid. Power is supplied sequentially from the first to the third layer, and energy waste originates from the first layer; IP2G will absorb this wasted energy. To meet D... Q The heat generation equipment is divided into two levels. First, the first level consists of uncontrollable, predetermined heat energy, which in this paper refers to the Q generated by the solar collector, PGU, and TST. solar Q r and Q s，out The second layer is for supplementary heat energy, which in this paper refers to the Q generated by the auxiliary boiler. b In a FEL, heating is supplied sequentially from the first floor to the second floor, and the waste of heat energy originates from the first floor. The TST and CCU can absorb the wasted heat energy.

[0031] When the system adopts a heat-driven power-based operation mode, the system will prioritize meeting heat demand in order to meet D. Q The heat generation equipment is divided into three layers. The first layer is environmentally friendly but unstable solar heat generation, which is referred to as Q in this article. solar Secondly, the second layer is the PGU (Power Generation Unit) for heat production, and the third layer is the auxiliary boiler. When the energy supply from the second layer is insufficient, the shortfall is made up by the heat Q provided by the auxiliary boiler. b This is satisfactory. Heating is provided sequentially from the first to the third floor, but heat waste originates from the first floor. The TST and CCU can absorb this wasted heat. To meet D... E The power generation equipment is divided into two levels. First, the first level consists of uncontrollable, predetermined electrical energy, which in this paper refers to renewable energy generation and the E generated by the PGU (Power Generation Unit). PV E wt and Epgu The second layer is the power grid. When the power supply from the first layer cannot meet the electricity demand, the insufficient power will be supplemented from the power grid. Power is supplied sequentially from the first layer to the second layer. The first layer may waste power, and IP2G will absorb the wasted power.

[0032] The performance of an integrated energy system is primarily measured by four indicators: Primary Energy Saving Rate (PESR), Carbon Dioxide Emission Reduction Rate (CDESR), Annual Operating Cost Reduction Rate (ATCSR), and Energy Waste Rate (η). ex .

[0033] Define Goal as the overall performance objective function of the integrated energy system, which can be expressed as:

[0034] Goal=ω1·PESR+ω2·CDESR+ω3·ATCSR-ω4·η ex

[0035] In the formula: ω1, ω2, ω3 and ω4 are PESR, CDESR, ATCSR and η, respectively. ex The weights are calculated using the entropy method in this invention, and the calculation formula is as follows:

[0036]

[0037] In the formula: e i Let be the entropy value of index i. PESR represents the primary energy reduction rate of the integrated energy system compared to the supply system, which can be calculated by the following formula:

[0038]

[0039] Where: PEC SP and PEC IES These represent the annual primary energy consumption of the SP system and the integrated energy system, respectively.

[0040] CDESR represents the CO2 emission reduction rate of the integrated energy system compared to the SP system, and it can be calculated by the following formula:

[0041]

[0042] In the formula: CDE SP and CDE IES These represent the annual carbon dioxide emissions of the SP system and the integrated energy system, respectively.

[0043] ATCSR represents the annual operating cost reduction rate of the integrated energy system compared to the SP system, which can be calculated by the following formula:

[0044]

[0045] Where: ATC SP and ATC IES These represent the annual operating costs of the SP system and the integrated energy system, respectively.

[0046]

[0047] η ex This represents the energy waste rate of IES equipment, E ex and Q ex E represents wasted electrical and thermal energy, respectively. offer and Q offer This indicates that it is provided to E ex and Q ex Electrical and thermal energy.

[0048] The main constraints of an integrated energy system are electrical balance, thermal balance, carbon dioxide balance, and equipment capacity balance. The constraints of the first three are shown below:

[0049] E wt (t)+E PV (t)+E grid (t)+E pgu (t)=E P2G (t)+E ec (t)+E ex (t)+E(t)

[0050] Q solar (t)+Q r (t)+Q b (t)+Q s,out (t)=Q ac,in (t)+Q he,in (t)+Q s,in (t)+Q ex (t)

[0051]

[0052] t∈[0,8760)

[0053] In the formula: E ec (t), E(t), E wt (t), E PV (t), E hrid (t), E pgu (t), E P2G (t), E ex (t) represents the power of the electric chiller, user electricity demand, wind power generation, photovoltaic power generation, grid-purchased electricity, PGU power generation, P2G power consumption, and wasted power at time t, respectively. r (t), Qs,out (t), Q s,in (t), Q solar (t), Q b (t), Q ac,in (t), Q he,in (t), Q ex (t) represent the heat recovery of PGU, the heat released and absorbed by the heat storage tank, the power of the solar collector, the power of the auxiliary boiler, the input power of the absorption chiller, the input power of the heat exchange device, and the wasted heat power at time t, respectively. These represent the carbon dioxide produced by the PGU at time t, the carbon dioxide produced by the power grid, the carbon dioxide produced by the auxiliary boiler, the carbon dioxide ultimately released into the atmosphere, the carbon dioxide required for P2G, and the carbon dioxide captured by the carbon capture device.

[0054] The constraints on equipment capacity are as follows:

[0055]

[0056]

[0057] 0≤A PV +A ST ≤3000

[0058] In the formula: P i (t) represents the power of device i at time t. Indicates the rated power of device i; A PV and A ST These represent the areas of the PV and the solar collector, respectively. This indicates the maximum carbon absorption capacity of the carbon capture unit. This represents the amount of carbon captured by the carbon capture device at time t.

[0059] The present invention, by adopting the above technical solution, achieves the following beneficial effects:

[0060] The improved P2G equipment has better performance compared to the traditional P2G. The IP2G in this paper has the following advantages: (1) IP2G takes into account the heat overflow during the electro-gas conversion process and combines this heat with the CCU, which not only increases the environmental benefits of P2G, but also reduces the energy loss of IP2G in this process. (2) It alleviates the serious problem of traditional IES abandoning wind and solar energy. (3) It reduces carbon dioxide emissions and primary energy consumption. Attached Figure Description

[0061] Figure 1 This is a schematic diagram of the improved P2G principle in this invention;

[0062] Figure 2 This is a structural diagram of the integrated energy system in this invention;

[0063] Figure 3 This is an annual performance chart of IP2G in terms of annual operating costs, carbon dioxide emissions, and primary energy consumption in this invention;

[0064] Figure 4 This is a graph showing the annual performance of IP2G in terms of energy waste rate in this invention. Detailed Implementation

[0065] The invention is further illustrated below with specific embodiments. To better illustrate the invention, the proposed mathematical model is verified using Matlab numerical simulation, and the results are shown in the appendix to the specification. Figures 3 to 4 As shown. The specific steps are as follows:

[0066] Step 1: The heat of reaction for the electro-gas conversion process is derived from the chemical reaction equation, and the traditional P2G model is optimized.

[0067] Step 2: The reaction heat derived from P2G in Step 1 is transferred to the carbon capture device. This heat is used to supply carbon capture and strengthen the thermal coupling between P2G and the carbon capture device.

[0068] Step 3: Apply the improved P2G model and carbon capture device to the integrated energy system;

[0069] Step 4: Using the annual operating cost saving rate, primary energy saving, and carbon dioxide emission reduction as objective functions, and the equipment configuration of the integrated energy system as variables, set constraints and use the honey badger algorithm as the solution algorithm to optimize the configuration.

[0070] Step 1: In the traditional P2G model, the amount of electrical energy converted into natural gas during P2G energy storage can be calculated as follows:

[0071] F P2G =E P2G ×η P2G,F

[0072] Among them, E P2G It is the electrical energy absorbed by P2G, η P2G,F The natural gas conversion rate of the P2G equipment is F. In this paper, F P2G This refers to the energy generated from natural gas through P2G (Power-to-Gas) equipment, measured in kilowatt-hours (kWh). P2G can convert electrical energy into natural gas, but the heat generated in this process is typically negligible. Therefore, improved P2G (IP2G) increases the utilization efficiency of P2G equipment, reducing this heat Q. P2G This can be derived from the electro-gas conversion reaction equation, which is:

[0073] 4H2+CO2→CH4+2H2O,ΔH=-165.01kJ / mol

[0074] Where ΔH represents the heat absorbed or released in the reaction. A positive ΔH indicates heat absorption, and a negative ΔH indicates heat release. The above formula shows that 165.01 kJ of heat is released for every 1 mol of CH4 produced. The conversion relationship between the yield of P2G per unit time and the exothermic reaction (assuming no branching products are produced during methanation) is as follows:

[0075]

[0076]

[0077] in, These represent the reaction rates of methanation and electro-hydrogen production, respectively. P represents the heat of reaction of P2G methanation. P2G This refers to the operating power of the IP2G device. It is the calorific value of CH4. and These are the densities of methane and hydrogen, respectively. and This indicates the relative molecular mass of methane and hydrogen. This is the proportion of the heat of reaction injected into the heating network; the calculated heat of reaction of IP2G when it absorbs 1MWh of electrical energy is as follows:

[0078]

[0079] Q P2G =E P2G ×η P2G,Q

[0080] In the formula: η P2G,Q The heat conversion rate of the IP2G equipment. Carbon dioxide, as one of the raw materials for the IP2G equipment, needs to be captured and transported to the IP2G via the CCU equipment. The amount of carbon dioxide consumed in this process... The calculation is as follows:

[0081]

[0082] In the formula: The carbon dioxide consumption rate of IP2G is given in this paper. The derivation and η P2G,Q Similarly, the chemical equation for water electrolysis and the law of conservation of energy can be used to calculate... It equals 11.2%.

[0083] Since the unit's cycle thermal efficiency decreases by about 9% when the carbon capture rate is around 90%, IP2G applies the waste heat generated during electrical energy storage to the CCU, thus avoiding the problem of traditional P2G equipment needing to reduce the unit's cycle thermal efficiency for carbon capture during operation. Furthermore, besides capturing the carbon dioxide required for P2G, the excess heat can also be used to capture carbon dioxide generated by other equipment in the system.

[0084] Step 2: Heat Q generated by IP2G P2G It can be directly used in carbon capture equipment; its specific schematic diagram is attached to the instruction manual. Figure 1 The heat shown is used by the carbon capture device to capture carbon dioxide. The following can be derived:

[0085]

[0086] and The difference between them is the net carbon capture amount after IP2G is combined with CCU, λ B Given the heat conversion coefficient of P2G, the net carbon capture coefficient per unit of IP2G heating can be derived from the formula above as follows:

[0087]

[0088] In the formula: λ P2G,ccu The unit is kW / kg, and the net carbon capture capacity per unit of IP2G can be calculated as follows:

[0089]

[0090] Step 3: Integrate IP2G and carbon capture equipment into a comprehensive energy system. The specific schematic diagram is shown in the attached instruction manual. Figure 2 As shown.

[0091] When the system adopts an electric-to-heat operation mode, in order to meet the electricity demand D E The power generation equipment is divided into three layers. First, the first layer is environmentally friendly but unstable new energy power generation, in this paper referring to solar and wind power. Second, the second layer provides power to the PGU (Power Generation Unit). Finally, the third layer is the power grid. Power is supplied sequentially from the first to the third layer, and energy waste originates from the first layer; IP2G will absorb this wasted energy. To meet D... Q The heat generation equipment is divided into two levels. First, the first level consists of uncontrollable, predetermined heat energy, which in this paper refers to the Q generated by the solar collector, PGU, and TST. solar Q r and Q s，out The second layer is for supplementary heat energy, which in this paper refers to the Q generated by the auxiliary boiler. bIn a FEL, heating is supplied sequentially from the first floor to the second floor, and the waste of heat energy originates from the first floor. The TST and CCU can absorb the wasted heat energy.

[0092] When the system adopts a heat-driven power-based operation mode, the system will prioritize meeting heat demand in order to meet D. Q The heat generation equipment is divided into three layers. The first layer is environmentally friendly but unstable solar heat generation, which is referred to as Q in this article. solar Secondly, the second layer is the PGU (Power Generation Unit) for heat production, and the third layer is the auxiliary boiler. When the energy supply from the second layer is insufficient, the shortfall is made up by the heat Q provided by the auxiliary boiler. b This is satisfactory. Heating is provided sequentially from the first to the third floor, but heat waste originates from the first floor. The TST and CCU can absorb this wasted heat. To meet D... E The power generation equipment is divided into two levels. First, the first level consists of uncontrollable, predetermined electrical energy, which in this paper refers to renewable energy generation and the E generated by the PGU (Power Generation Unit). PV E wt and E pgu The second layer is the power grid. When the power supply from the first layer cannot meet the electricity demand, the insufficient power will be supplemented from the power grid. Power is supplied sequentially from the first layer to the second layer. The first layer may waste power, and IP2G will absorb the wasted power.

[0093] Step 4: The performance of the integrated energy system is mainly measured by four indicators: Primary Energy Saving Rate (PESR), Carbon Dioxide Emission Reduction Rate (CDESR), Annual Operating Cost Reduction Rate (ATCSR), and Energy Waste Rate (η). ex .

[0094] Define Goal as the overall performance objective function of the integrated energy system, which can be expressed as:

[0095] Goal=ω1·PESR+ω2·CDESR+ω3·ATCSR-ω4·η ex

[0096] In the formula: ω1, ω2, ω3 and ω4 are PESR, CDESR, ATCSR and η, respectively. ex The weights are calculated using the entropy method in this invention, and the calculation formula is as follows:

[0097]

[0098] In the formula: e i Let be the entropy value of index i. PESR represents the primary energy reduction rate of the integrated energy system compared to the supply system, which can be calculated by the following formula:

[0099]

[0100] Where: PEC SP and PEC IES These represent the annual primary energy consumption of the SP system and the integrated energy system, respectively.

[0101] CDESR represents the CO2 emission reduction rate of the integrated energy system compared to the SP system, and it can be calculated by the following formula:

[0102]

[0103] In the formula: CDE SP and CDE IES These represent the annual carbon dioxide emissions of the SP system and the integrated energy system, respectively.

[0104] ATCSR represents the annual operating cost reduction rate of the integrated energy system compared to the SP system, which can be calculated by the following formula:

[0105]

[0106] Where: ATC SP and ATC IES These represent the annual operating costs of the SP system and the integrated energy system, respectively.

[0107]

[0108] η ex This represents the energy waste rate of IES equipment, E ex and Q ex E represents wasted electrical and thermal energy, respectively. offer and Q offer This indicates that it is provided to E ex and Q ex Electrical and thermal energy.

[0109] The main constraints of an integrated energy system are electrical balance, thermal balance, carbon dioxide balance, and equipment capacity balance. The constraints of the first three are shown below:

[0110] E wt (t)+E PV (t)+E grid (t)+E pgu (t)=E P2G (t)+E ec (t)+E ex (t)+E(t)

[0111] Q solar (t)+Q r (t)+Q b (t)+Q s,out (t)=Q ac,in (t)+Qhe,in (t)+Q s,in (t)+Q ex (t)

[0112]

[0113] t∈[0,8760)

[0114] In the formula: E ec (t), E(t), E wt (t), E PV (t), E grid (t), E pgu (t), E P2G (t), E ex (t) represents the power of the electric chiller, user electricity demand, wind power generation, photovoltaic power generation, grid-purchased electricity, PGU power generation, P2G power consumption, and wasted power at time t, respectively. r (t), Q s,out (t), Q s,in (t), Q solar (t), Q b (t), Q ac,in (t), Q he,in (t), Q ex (t) represent the heat recovery of PGU, the heat released and absorbed by the heat storage tank, the power of the solar collector, the power of the auxiliary boiler, the input power of the absorption chiller, the input power of the heat exchange device, and the wasted heat power at time t, respectively. These represent the carbon dioxide produced by the PGU at time t, the carbon dioxide produced by the power grid, the carbon dioxide produced by the auxiliary boiler, the carbon dioxide ultimately released into the atmosphere, the carbon dioxide required for P2G, and the carbon dioxide captured by the carbon capture device.

[0115] The constraints on equipment capacity are as follows:

[0116]

[0117]

[0118] 0≤A PV +A ST ≤3000

[0119] In the formula: P i (t) represents the power of device i at time t. Indicates the rated power of device i; A PV and A ST These represent the areas of the PV and the solar collector, respectively. This indicates the maximum carbon absorption capacity of the carbon capture unit. This represents the amount of carbon captured by the carbon capture device at time t.

[0120] (1) The simulation parameters are as follows

[0121] The operating parameters of the improved integrated energy system equipment are as follows:

[0122]

[0123] The prices of integrated energy system equipment are as follows:

[0124]

[0125]

[0126] The range of algorithm variables is as follows:

[0127]

[0128] To demonstrate the effectiveness of IP2G, an integrated energy system incorporating IP2G was compared with a traditional P2G system.

[0129] The various configuration features are as follows:

[0130]

[0131] Results explanation:

[0132] The solution results under the electric constant heat operation mode are as follows:

[0133]

[0134] The solution results under the thermal constant-electricity operation mode are as follows:

[0135]

[0136] Both traditional P2G and IP2G systems outperform distributed power supply systems in terms of overall annual performance. Comparing two configurations for each of the two operating modes, Case 2 shows the best overall performance, with an objective function of 26.43%. It also demonstrates superior performance in primary energy savings, CO2 emission reduction, annual operating cost savings, and η. ex The performance rates were 42.02%, 72.13%, 0.08% (considering initial investment costs), and 12.49%, respectively.

[0137] The annual performance is shown in the table below:

[0138]

[0139] Typical daily analysis of integrated energy systems includes typical daily performance of carbon dioxide balance and tiered carbon penalty response.

[0140] To demonstrate the advantages of IP2G over traditional P2G, the table below shows that IP2G significantly improves annual operating costs, primary energy consumption, carbon dioxide emissions, and objective function compared to traditional P2G. Since the heat spillover of traditional P2G is not considered, the CCU needs to consume additional system heat for carbon capture, increasing the system's primary energy consumption and carbon dioxide capture costs. As a result, traditional P2G's carbon dioxide emission reduction performance is not as good as IP2G.

[0141]

[0142] Its integrated energy system, equipped with IP2G, has monthly performance data as shown in the attached instruction manual. Figure 3 Included with instruction manual Figure 4 As shown. The appendix to the Ming Dynasty document is included. Figure 3 The instruction manual includes figures for Monthly Operating Costs (MTCSR), Carbon Dioxide Emissions (CDESR), and Primary Energy Consumption (PESR). Figure 4 Indicates energy efficiency (η) E ) and thermal efficiency (η) Q ).

[0143] From the instruction manual Figure 3 It can be observed that IES's MTCSR, CDESR, and PESR perform best in spring and autumn, followed by summer, and worst in winter. The reasons are as follows: First, in spring and autumn, Q... h and Q c The sum is relatively small, while the output of solar and wind power accounts for a larger proportion at this time. IES's IP2G can reduce the curtailment rate of wind and solar power, thus the primary energy consumption is relatively small, and the monthly operating cost (excluding initial investment) and carbon dioxide emissions also decrease accordingly. The best month for annual performance of MTCSR, CDESR, and PESR is April, with values ​​of 54.81%, 90.19%, and 60.33%, respectively. Secondly, in summer, Q c With E increasing, Q h The decrease in energy consumption is due to the use of FEL operation; an increase in E would increase primary energy consumption. However, with high average temperatures, solar output is at a relatively high level throughout the year, which also leads to increased heating capacity (Q) for the first layer. solar and Q rThe efficiency is greatly improved. In traditional IES, this energy is wasted due to the lack of a CCU, but in IP2G, the overflowing heat can be utilized by carbon capture, reducing carbon emissions during high-emission seasons. Therefore, although the annual performance of MTCSR, CDESR, and PESR declines in summer, they can still be maintained above 41.13%, 73.54%, and 43.78%, respectively. Finally, in winter, although Q... c Decline, but Q h The energy output increases, and as the average temperature rises, the solar energy output capacity decreases. Furthermore, under the condition of electricity versus heat, the energy output (E) in winter does not increase compared to other seasons, and the first layer of heat energy supply (Q)... solar and Q r The energy consumption of auxiliary boilers is insufficient to meet actual heat demand, requiring them to consume more primary energy to satisfy this demand. Therefore, during winter, the integrated energy system exhibits the worst annual performance in terms of MTCSR, CDESR, and PESR, with worst performance rates of 35.50%, 57.72%, and 37.38%, respectively.

[0144] From the instruction manual Figure 4 It can be observed that, overall, η E Even in its worst-case scenario, the system achieves a performance rate of 93.23% throughout the year, demonstrating high energy efficiency and a high η (efficiency) for the integrated energy system. E It performs best in summer, relatively well in winter, and poorly in spring and autumn. η of the integrated energy system Q The system performs best in winter, relatively well in summer, and poorly in spring and autumn. The reasons are as follows: First, in winter, the photovoltaic and solar thermal collection capacity is relatively lower than in other seasons, thus reducing the first-level power supply and heating. Under FEL, the energy waste only originates from the first level, and the wasted energy is less than the rated power of P2G, so most of it is absorbed and converted into natural gas. As mentioned above, in winter, the first-level heating is insufficient to meet the heat demand, while the second-level heating, used to supplement the heat demand, does not generate wasted heat energy. Second, in summer, because the increase in E is much greater than the increase in first-level power supply due to climate, the integrated energy system needs to meet the electricity demand through second-level power supply, and this process does not result in energy waste. Furthermore, although FEL generates a large amount of heat energy in summer that far exceeds the heat demand, the high carbon dioxide emissions and the implementation of tiered carbon penalties in summer significantly increase the cost of carbon penalties. The SCPR dynamic response CCU utilizes this heat energy to capture carbon dioxide to reduce the carbon penalty, thereby increasing η. Q It also performs well in summer. Finally, in spring and autumn, since these are not peak CO2 emission seasons, the cost of carbon capture outweighs the cost of carbon emissions, resulting in lower CCU operating power compared to summer and winter. Therefore, η Q The performance was poor.

[0145] In summary, the optimized configuration method designed in this invention improves the utilization efficiency of P2G and further enhances its energy storage cost-effectiveness.

[0146] The above specific implementation examples are only for the purpose of helping those skilled in the art to understand the present invention. However, the present invention is not limited to the situations in the examples. For those skilled in the art, as long as the various changes are within the spirit and scope of the present invention as defined and determined by the appended claims, these changes are obvious. All inventions utilizing the concept of the present invention are protected.

Claims

1. An optimized method for improving the thermal efficiency of P2G and the thermal coupling of carbon capture equipment, characterized in that, The optimization method includes the following steps: Step 1: The heat of reaction for the electro-gas conversion process is derived from the chemical reaction equation. The traditional P2G model is then optimized and improved to obtain the IP2G model. Step 2: The heat of reaction derived from P2G in Step 1 is transferred to the carbon capture device. This heat is used to supply carbon capture and strengthen the thermal coupling between IP2G and the carbon capture device. Step 3: Apply the IP2G model and carbon capture device to the integrated energy system; Step 4: Using the annual operating cost saving rate, primary energy saving amount, and carbon dioxide emission reduction as objective functions, and the equipment configuration of the integrated energy system as variables, set constraints, and use the honey badger algorithm as the solution algorithm to optimize the configuration. Step 1 is described in detail as follows: In the traditional P2G model, the amount of electrical energy converted into natural gas during P2G energy storage can be calculated as follows: ， in, It is the electrical energy absorbed by P2G. It refers to the natural gas conversion rate of P2G equipment; It refers to the energy generated from natural gas through P2G equipment, measured in kilowatt-hours. P2G can convert electricity into natural gas, and the IP2G model can derive the heat generated during this conversion process from the electro-gas reaction equation. The electro-gas conversion equation is as follows: ， in, It is the heat absorbed or released by the reaction, when When it is positive, it indicates that heat has been absorbed. A negative value indicates the release of heat; The conversion relationship between the yield of P2G per unit time and the exothermic reaction is as follows: ， ， in, , These represent the reaction rates of methanation and electro-hydrogen production, respectively. This represents the heat of reaction of P2G methanation. This refers to the operating power of the IP2G device. It is the calorific value of CH4. and These are the densities of methane and hydrogen, respectively. and This indicates the relative molecular mass of methane and hydrogen. This is the proportion of the heat of reaction injected into the heating network; the calculated heat of reaction of IP2G when it absorbs 1MWh of electrical energy is as follows: ， ， In the formula: For the heat conversion rate of IP2G equipment, For P2G equipment to generate power, carbon dioxide, as one of the raw materials for IP2G equipment, needs to be captured and transported to IP2G via CCU equipment. The amount of carbon dioxide consumed in this process... The calculation is as follows: ， In the formula: This represents the carbon dioxide consumption rate of IP2G. It equals 11.2%.

2. The optimized method for improving P2G thermal utilization and thermal coupling of carbon capture equipment according to claim 1, characterized in that, The specific steps of step 2 are as follows: Heat generated by IP2G It can be directly used in carbon capture equipment to capture carbon dioxide. The following can be derived: ， and The difference between them represents the net carbon capture amount after IP2G is combined with CCU. Given the heat conversion coefficient of P2G, the net carbon capture coefficient per unit of IP2G heating can be derived from the formula above as follows: ， In the formula: The unit is kW / kg, and the net carbon capture capacity per unit of IP2G can be calculated as follows: 。 3. The optimized method for improving P2G thermal utilization and thermal coupling of carbon capture equipment according to claim 1, characterized in that, The specific steps of step 3 are as follows: When the integrated energy system adopts an electricity-driven, heat-driven operation mode, in order to meet electricity demand... The power generation equipment is divided into three layers: the first layer is environmentally friendly but unstable new energy power generation, including solar and wind power generation; the second layer provides power to PGU; the third layer is the power grid; power is supplied sequentially from the first layer to the third layer, and the waste of power comes from the first layer. IP2G will absorb the wasted power. In order to satisfy The heat generation equipment is divided into two levels; the first level is uncontrollable, predetermined heat energy, including Q generated by the solar collector, PGU, and TST. solar Q r and Q s，out The second layer provides supplementary heat energy, including Q generated for the auxiliary boiler. b In FEL, heating is supplied sequentially from the first floor to the second floor, and the waste of heat energy originates from the first floor. The TST and CCU can absorb the wasted heat energy. When the integrated energy system adopts a heat-driven power generation mode, the system will prioritize meeting heat demand in order to meet... The heat generation equipment is divided into three layers: the first layer is environmentally friendly but unstable solar heat generation, which is Q. solar The second layer is the PGU (Power Generation Unit) for heat production, and the third layer is the auxiliary boiler. When the second layer's energy supply is insufficient, the shortfall is made up by the heat Q provided by the auxiliary boiler. b The heating is supplied sequentially from the first to the third floor, while the waste of heat energy originates from the first floor. The TST and CCU can absorb the wasted heat energy. In order to satisfy The power generation equipment is divided into two levels; the first level is uncontrollable, predetermined electrical energy, including E generated for new energy power generation and PGU. PV E wt and E pgu The second layer is the power grid. When the power supply of the first layer cannot meet the power demand, the insufficient power will be supplemented from the power grid. Power is supplied sequentially from the first layer to the second layer. The first layer will waste power, and IP2G will absorb the wasted power.

4. The optimized method for improving P2G thermal utilization and thermal coupling of carbon capture equipment according to claim 1, characterized in that, The specific steps of step 4 are as follows: The performance of an integrated energy system is primarily measured by four indicators: Primary Energy Saving Rate (PESR), Carbon Dioxide Emission Reduction Rate (CDESR), Annual Operating Cost Reduction Rate (ATCSR), and Energy Waste Rate. ; definition The overall performance objective function of the integrated energy system is expressed as: ， In the formula: , , and They are respectively , and The weights are calculated using the entropy method, and the formula is as follows: ， In the formula: Let be the entropy value of index i; PESR represents the primary energy reduction rate of the integrated energy system compared to the supply system, which can be calculated by the following formula: ， In the formula: and These represent the annual primary energy consumption of the SP system and the integrated energy system, respectively. CDESR represents the CO2 emission reduction rate of the integrated energy system compared to the SP system, and it can be calculated by the following formula: ， In the formula: and These represent the annual carbon dioxide emissions of the SP system and the integrated energy system, respectively. ATCSR represents the annual operating cost reduction rate of the integrated energy system compared to the SP system, which can be calculated by the following formula: ， In the formula: and These represent the annual operating costs of the SP system and the integrated energy system, respectively. ， This represents the energy waste rate of IES equipment. and These represent wasted electrical and thermal energy, respectively. and Indicates to provide and Electrical and thermal energy; The constraints of an integrated energy system are electrical balance, thermal balance, carbon dioxide balance, and equipment capacity balance. The constraints of the first three are as follows: ， ， ， ， In the formula: , , , , , , The figures at time t are: electric chiller power, user electricity demand, wind power generation, photovoltaic power generation, grid-purchased electricity, PGU power generation, P2G power consumption, and wasted power. , , , , , , , These represent the heat recovery of the PGU, the heat released and absorbed by the heat storage tank, the power of the solar collector, the power of the auxiliary boiler, the input power of the absorption chiller, the input power of the heat exchange device, and the wasted heat power at time t, respectively. , , , , , These represent the carbon dioxide produced by the PGU at time t, the carbon dioxide produced by the power grid, the carbon dioxide produced by the auxiliary boiler, the carbon dioxide ultimately released into the atmosphere, the carbon dioxide required for P2G, and the carbon dioxide captured by the carbon capture device, respectively. The constraints on equipment capacity are as follows: ， ， ， In the formula: This represents the power of device i at time t. This indicates the rated power of device i; and These represent the areas of the PV and the solar collector, respectively. This indicates the maximum carbon absorption capacity of the carbon capture unit. This represents the amount of carbon captured by the carbon capture device at time t.

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