Agricultural park comprehensive energy system cooling, heating and power optimization scheduling method based on biomass-solar energy coupling

Abstract

The invention discloses an agricultural park comprehensive energy system cooling, heating and power optimization scheduling method based on biomass-solar energy coupling. The method comprises the following steps: constructing an agricultural park comprehensive energy system based on biomass-solar energy coupling; based on the load characteristics of the agricultural park, constructing an agricultural park flexible load model; an agricultural park integrated energy system cooling, heating and power optimization scheduling model based on biomass-solar energy coupling is constructed, and a stepped carbon transaction mechanism model is introduced to limit carbon emission. The invention provides an agricultural park comprehensive energy system cooling, heating and power optimization scheduling method based on biomass-solar energy coupling. The problems of insufficient energy supply, high carbon emission and high cost of partial agricultural park comprehensive energy systems can be solved.

Description

Technical Field

[0001] The invention relates to the field of optimization and scheduling of integrated energy systems, and in particular to a method for optimizing the scheduling of cooling, heating and electricity of an integrated energy system in an agricultural park based on biomass-solar energy coupling. Background Art

[0002] Social and economic development has led to an increasing demand for energy and a reduction in fossil energy reserves. The consumption of fossil energy has brought about environmental problems, and large amounts of carbon emissions have exacerbated the greenhouse effect, causing global warming. Increasing the use of non-fossil energy and reducing carbon emissions are key issues that need to be addressed urgently.

[0003] IES internally couples multiple energy sources for joint supply to meet the terminal multi-energy load demand, which is an important support for promoting the utilization of non-fossil energy and reducing carbon emissions. At present, most of the literature focuses on the low-carbon economic operation of IES, such as Literature 1: "Thermoelectric optimization of integrated energy system considering step-by-step carbon trading mechanism and electric hydrogen production [J]. Electric Power Automation Equipment, 2021, 41(09): 48-55.", Literature 2: "Multi-time scale optimization scheduling of integrated energy system with power-to-gas and carbon capture coupling [J]. China Electric Power, 1-13.". Although the low-carbon economic scheduling model established in the above literature can effectively reduce carbon emissions and improve economic benefits, the specific application scenarios of IES are somewhat vague. Therefore, Literature 3: "Research on low-carbon economic scheduling method of integrated energy system in agricultural park [D]. Hebei Agricultural University, 2023.", Literature 4: "Research on optimization scheduling method of integrated energy system in facility agriculture industrial park [D]. Lanzhou University of Technology, 2021." The above literature focuses on the low-carbon economic operation of IES in agricultural park and utilizes biomass energy. However, the established AIES model structure is relatively simple, ignoring the consumption of wind and solar energy and the mutual conversion between various energy sources, resulting in the failure to further improve the performance of AIES.

[0004] Demand response is a way for users to participate in system dispatch. By guiding users to adjust their energy demand through energy market prices and incentive response mechanisms, it can effectively reduce load fluctuations and achieve economic operation of the system. Reference 5: "Optimal dispatch of integrated energy system considering step-by-step carbon trading mechanism [J]. China Electric Power, 1-12.", Reference 6: "Low-carbon optimized operation of park integrated energy system considering CCPP-P2G-CHP synergy [J / OL]. Journal of North China Electric Power University (Natural Science Edition), 1-12.", although the above references have established a relatively complete demand response model, it is still necessary to analyze the load type specifically for different IES loads and select the appropriate demand response mechanism according to the load type.

[0005] Biomass is a renewable organic matter produced by green plants through photosynthesis, which can be divided into multiple fields such as agriculture, forestry, aquatic products and waste. Biomass energy has a shorter carbon emission cycle than fossil energy, which allows the emitted CO2 to complete the carbon cycle in nature, that is, the net emission of CO2 is close to zero, so biomass is called a carbon neutral fuel. Biomass resources are universal, with short regeneration cycles, low pollution and high energy potential. By using advanced energy processing methods to utilize them, it will help solve the IES energy supply problem in agricultural parks or remote rural areas, improve agricultural production and lifestyle, and promote the construction of modern agricultural parks.

[0006] Agricultural parks can produce a large amount of biomass. How to use it efficiently is of great significance to the development of agricultural parks. Reference 7: "Research on the Integration of CCHP Systems for Coupled Buildings with Biomass, Solar Energy and Geothermal Energy [D]. Hunan University, 2018. ", Reference 8: "Optimization of Biomass Integrated Energy System Considering Step-by-Step Carbon-Green Certificate Joint Trading and Demand Response [J]. Electric Power Science and Engineering, 2024, 40(07): 10-25. ", The above references studied the utilization scenarios of biomass energy in IES, but did not consider the source of biomass. Reference 9: "Agricultural Industrial Park Integrated Energy System Planning Method Considering Biomass Energy and Agricultural Flexible Load [J]. Power System Technology, 2024, 48(05): 1836-1845. "Biomass gas and biochar are produced by pyrolysis gasification furnace, and biogas is produced by highly anaerobic fermentation of manure, and AIES considering biomass energy and agricultural flexible load is established, but the system structure is relatively simple and the absorption capacity is poor. Summary of the invention

[0007] The technical problem to be solved by the present invention is to provide a method for optimizing the scheduling of heat, cooling and electricity in an agricultural park integrated energy system based on biomass-solar energy coupling, which can solve the problems of insufficient energy supply, high carbon emissions and high costs in some agricultural park integrated energy systems.

[0008] In order to solve the above technical problems, the technical solution adopted by the present invention is:

[0009] A cooling, heating and electricity optimization scheduling method for an agricultural park integrated energy system based on biomass-solar energy coupling comprises the following steps:

[0010] Step 1: Construct an integrated energy system for agricultural parks based on biomass-solar energy coupling;

[0011] Step 2: Based on the load characteristics of the agricultural park, a flexible load model of the agricultural park is constructed;

[0012] Step 3: Construct an optimal scheduling model for cooling, heating and electricity of the agricultural park integrated energy system based on biomass-solar energy coupling, and introduce a step-by-step carbon trading mechanism model to limit carbon emissions.

[0013] In step 1, a comprehensive energy system for agricultural parks based on biomass-solar energy coupling is constructed, which specifically includes:

[0014] (1) Construct a biomass-solar coupling device model;

[0015] (2) Construct a power-to-gas (P2G) and carbon capture (CCS) coupling equipment model;

[0016] (3) Construct an energy conversion device model;

[0017] (4) Construct an energy storage device model.

[0018] (1) The biomass-solar coupling device model is constructed, which specifically includes:

[0019] 1) Constructing biomass gasification model

[0020] After being heated by the preheater, the biomass enters the gasification tank. Its gas production rate is related to the temperature. The biomass gas production rate and biomass output model are as follows:

[0021]

[0022] Where: η b,t and T t are the gas production rate and temperature of the biomass gas pool at time t; T0 is the most suitable temperature of the biomass gas pool, which is generally 35°C; P BSC,b,t and m bio,t are the biomass input power and biomass mass flow rate at time t respectively; LHV is the lower heating value of biomass;

[0023] 2) Constructing a biomass gasification pool model

[0024] The energy to maintain the appropriate temperature of the biomass gasification pool is provided by the solar collector and the heat exchanger. The heat balance formula and heat dissipation model in the biomass gasification pool are as follows:

[0025]

[0026] Where: ρ and C p is the density and specific heat capacity of biomass materials; V d is the volume of the gasification pool; HRT is the time the material is in the gas pool; T amb,t is the ambient temperature at time t; U h and S d is the total heat transfer coefficient and total heat dissipation area of ​​the gasification pool; P GT,h,t and P GT,loss,t are the energy and heat dissipation required by the gasification pool at time t respectively;

[0027] 3) Construct a solar collector model

[0028] The solar collector gives priority to supplying heat to the biomass gasification pool, and the excess heat can be directly shared with the heat load; the solar collector model is as follows:

[0029] P TC,t =n TC η TC,t G TC,t Q TC (3);

[0030] Where: P TC,t , η TC,t and G TC,t is the output power, conversion efficiency and light radiation intensity of the solar collector at time t; n TC is the number of collectors; Q TC is the area of ​​a single collector;

[0031] 4) Constructing a biomass-solar coupled BSC system model

[0032] Part of the biomass gas is burned in an internal combustion engine to generate electricity, and part of it is used to generate heat through a heat exchanger. Part of the generated heat energy meets the heat load, part is supplied to the biomass gasification pool, and the other part is supplied to the absorption refrigeration machine for cooling; the biomass-solar coupled BSC system model is as follows:

[0033]

[0034] Where: P BSC,e,t , P BSC,h,t and P BSC,c,t are the electrical power, thermal power and cooling power output by BSC at time t respectively; P BSC,b,t is the total power input to BSC at time t; P HRB,h,t P is the heat energy supplied to the refrigerator at time t; HRB,tc,t P is the heat energy supplied to the gasification pool; TC,h,t The thermal energy that supplies the heat load to the solar collector at time t; η BSC,e , η BSC,h and η BSC,c are the electrical, thermal and cooling efficiencies of BSC output respectively; P GT,h,t is the energy required by the biomass gasification pool at time t;

[0035] Among them, the operation constraints and ramp constraints of the BSC system are as follows:

[0036]

[0037] Where: and They are the upper and lower limits of the BSC system input power respectively; and The upper and lower limits of the BSC system climbing power; and The upper and lower limits of the input absorption chiller power; and Input the upper and lower limits of the absorption chiller's ramp power; and They are the upper and lower limits of the heat energy delivered to the gasification pool; and They are respectively the upper and lower limits of the climbing power of the transport gasification pool.

[0038] (2) The power-to-gas (P2G) and carbon capture (CCS) coupling equipment model is constructed, including:

[0039] The power-to-gas (P2G) and carbon capture (CCS) coupling equipment can absorb excess wind and solar energy and reduce CO2 emissions. The power-to-gas (P2G) and carbon capture (CCS) coupling model is as follows:

[0040] 1) Electrolyzer EL

[0041]

[0042] Where: P EL,e,t is the electrical energy input to EL at time t; is the hydrogen energy of EL input at time t; η EL is the energy conversion efficiency of EL; are the upper and lower limits of the input EL power, respectively; They are the upper and lower limits of EL climbing power respectively;

[0043] 2) Methane Reactor MR

[0044]

[0045] Where: is the hydrogen energy input into MR at time t; P MR,g,t is the gas power output by MR at time t; η MR is the energy conversion efficiency of MR; are the upper and lower limits of hydrogen power input to MR, respectively; are the upper and lower limits of MR climbing power respectively;

[0046] 3) Hydrogen fuel cell HFC

[0047]

[0048] Where: is the hydrogen power input to HFC at time t; P HFC,e,t is the HFC output power at time t; η HFC The efficiency of HFC energy conversion; are the upper and lower limits of the input HFC hydrogen power, respectively; They are the upper and lower limits of HFC climbing power respectively;

[0049] 4) Carbon capture CCS

[0050] Considering the problem of coupling failure between P2G and CCS due to insufficient wind and solar energy output, a CO2 storage tank is introduced into the carbon capture CCS to strengthen the coupling between power-to-gas P2G and carbon capture CCS; CO2 mainly comes from gas boilers and BSC systems; the carbon capture CCS model is as follows:

[0051]

[0052] Where: P CCS,t , P CCS,f,t and P CCS,o,t are the total energy consumption, fixed energy consumption and operating energy consumption of CCS at time t respectively; is the mass of CO2 captured by CCS at time t; ε CCS is the energy consumption coefficient of CCS; and are the CO2 masses produced by GB and BSC at time t; ω CCS Efficiency of capturing CO2 for CCS; and The amount of CO2 provided and the amount of CO2 stored by CCS required by MR at time t, respectively;

[0053] Among them: The operating power constraint and climbing power constraint of CCS are as follows:

[0054]

[0055] Where: They are the upper and lower limits of CCS energy consumption respectively; They are the upper and lower limits of CCS climbing energy consumption respectively.

[0056] (3) Construct an energy conversion device model, including:

[0057] The energy conversion equipment includes electric boiler EB, electric refrigerator ERU and gas boiler GB; electric boiler EB is used to convert electrical energy into heat energy, electric refrigerator ERU converts electrical energy into cold energy, and gas boiler GB burns natural gas to generate heat energy; the models are as follows:

[0058] 1) Electric boiler EB

[0059]

[0060] Where: P EB,e,t is the electric power consumed by EB at time t; P EB,h,tis the thermal power generated by EB at time t; η EB is the heating efficiency of EB; They are the upper and lower limits of EB power consumption respectively; The upper and lower limits of EB's climbing power;

[0061] 2) Electric Refrigerator ERU

[0062]

[0063] Where: P ERU,e,t is the electric energy consumed by ERU at time t; P ERU,c,t is the cooling energy generated by ERU at time t; η ERU is the ERU cooling efficiency; The upper and lower limits of the input ERU electric power; They are the upper and lower limits of ERU climbing power respectively;

[0064] 3) Gas boiler GB

[0065]

[0066] Where: P GB,g,t , P GB,h,t They represent the input gas power and output thermal power of GB at time t respectively; η GB is GB energy conversion efficiency; The upper and lower limits of GB input power; These are the upper and lower limits of GB’s climbing power.

[0067] (4) Construct the energy storage device model, including:

[0068] Multi-energy storage includes electric energy storage, thermal energy storage, cold energy storage and hydrogen energy storage. The general model is as follows:

[0069] 1) Charging and discharging power and state constraints:

[0070]

[0071] Where: x is the type of energy storage device, e, h, c and H2 represent electric, heat, cold and hydrogen energy storage respectively; P x,cha,t , P x,dis,t They represent the charging and discharging power of energy storage device x at time t; I x,cha,t ,I x,dis,t They represent the charging and discharging states of the energy storage device x at time t respectively; and Respectively represent the upper and lower limits of the charging power of the energy storage device x; and They represent the upper and lower limits of the energy storage device x’s discharge power respectively;

[0072] 2) Energy storage state continuity constraint:

[0073]

[0074] Where: S x,t is the storage capacity of energy storage device x at time t; x is the self-loss coefficient of energy storage device x; η x,cha , η x,dis are the charging and discharging efficiencies of energy storage device x respectively; is the upper and lower limits of energy storage capacity; S x,1 is the storage capacity of energy storage device x at time 1; S x,24 is the storage capacity of energy storage device x at 24 hours.

[0075] In step 2, the flexible load model of the agricultural park is constructed, which specifically includes:

[0076] (1) Construct a flexible load model for agricultural parks;

[0077] 1) The greenhouse electrical load includes electric irrigation machines, ventilators, roller shutter machines, plant lighting and crop dryers. The greenhouse electrical load model is as follows:

[0078]

[0079] Where: P gh,e,t is the power consumption of the greenhouse at time t; P pump,t , P fan,t , P driver,t , P light,t and P ldryer,t are the rated power of a single electric irrigation machine, ventilator, roller shutter machine, plant supplementary light and crop dryer respectively; d pump,t d fan,t d driver,t d light,t and d dryer,t is a 0-1 variable, corresponding to the working status of the electric irrigation machine, ventilator, roller shutter, plant light and crop dryer; N1 is the number of electric irrigation machines; N2 is the number of ventilators; N3 is the number of roller shutters; N4 is the number of plant light; N5 is the number of crop dryers;

[0080] 2) The heat load model of the greenhouse is as follows:

[0081]

[0082] Where: T gh,t is the greenhouse temperature at time t; T gh,t+1 is the greenhouse temperature at time t+1; P gh,su,t , P gh,in,t and Pgh,loss,t are the heat supply, heat production and heat dissipation of the greenhouse at time t; ρ air 、c air and ν gh are respectively the air density, specific heat capacity and greenhouse volume of the greenhouse. gh,loss,t Includes heat losses from walls, floors and air flow;

[0083] 3) The power load of the breeding farm includes ventilation system, feed feeding system and waste treatment system. The heating model of the breeding farm is as follows:

[0084]

[0085] Where: P farm,e,t is the power consumption of the breeding farm at time t; P t air , P t feed and P t waste are the power consumption of ventilation system, feeding system and waste treatment system at time t; β t air , β t feed and β t waste are 0-1 variables, indicating whether the ventilation system, feed feeding system and waste treatment system are in working state at time t; M1 is the number of ventilation systems; M2 is the number of feed feeding systems; M3 is the number of waste treatment systems;

[0086] Among them, the feed feeding system integrates feed crusher, feed mixer and automatic feeder. The electrical load model of the feed feeding system is as follows:

[0087]

[0088] Where: P t feed is the output of the feeding system at time t; and They are the rated power of feed crusher, feed mixer and automatic feeder respectively; α cut , α mix and α rel It is a 0-1 variable, indicating the working status of each device; η i mix and The working efficiency of each equipment in the feed feeding system;

[0089] The waste treatment system includes sewage treatment equipment and garbage crushing equipment. The electrical load model of the waste treatment system is as follows:

[0090] P t waste =P t sewage +P t duc (20);

[0091] Where: g and eP t duc are the power of treating sewage and park garbage at time t respectively; The power consumption of the waste treatment system;

[0092] (2) Conduct flexible load characteristics analysis in agricultural parks;

[0093] 1) Translable load

[0094] The shiftable load has continuous power consumption time, and the shiftable load model is as follows:

[0095]

[0096] Where: and L shift are the loads before and after translation respectively; S shift is the set of starting periods; They are respectively S ,t S+1 ,t D Load at the moment; P τ shift , They are respectively after translation at τ, τ+1, τ+t D -1 time load; [t sh- ,t sh+ ] is the shiftable interval; t s is the starting period; t D is a duration period;

[0097] The cost of the park to be compensated after the translation F shift for:

[0098]

[0099] Where: Price compensation for unit load shifting; For L shift The sum of translation loads; t sh- is the starting time of load translation; t sh+ -t D +1 is the starting time after the load translation;

[0100] 2) The transferable load model is as follows:

[0101]

[0102] Where: are the upper and lower limits of the transferable load respectively; β t is a 0-1 variable, indicating whether to transfer at time t; , P t tran are the loads at time t before and after the transfer; [t tr- ,t tr+ ] is the transfer interval;

[0103] The cost of the park to be compensated after the transfer F tran for:

[0104]

[0105] Where: compensation price for load shifting;

[0106] 3) The load reduction model is as follows:

[0107]

[0108] Where: P t cut* , P t cut are the loads before and after the reduction at time t; γ t is a 0-1 variable, indicating whether it is cut at time t; is the maximum continuous reduction time; N max is the maximum number of reductions;

[0109] Costs to be compensated to the park after reduction F cut for:

[0110]

[0111] Where: The compensation price for load reduction.

[0112] In step 3, a cooling, heating and electricity optimization scheduling model for the agricultural park integrated energy system based on biomass-solar energy coupling is established, which specifically includes:

[0113] Step 3.1: Construct the objective function

[0114] Energy purchase cost C based on agricultural park integrated energy system AIES buy , wind and solar cost C cut , Carbon trading costs Operation and maintenance cost Com and the park compensation cost C fill , construct with a total cost C total The minimum low-carbon economy targets are as follows:

[0115]

[0116] 1) Energy purchase cost

[0117]

[0118] Where: α e and α g are the unit prices of electricity and gas respectively; P e,buy,t , P g,buy,t They are the power of electricity and gas purchased at time t respectively; T is the time period;

[0119] 2) Cost of curtailing wind and solar power

[0120]

[0121] Where: wt , δ pv are the penalty factors for wind and solar abandonment, respectively; P wt,cut,t , P pv,cut,t They are wind power abandonment and solar power abandonment at time t respectively;

[0122] 3) Carbon trading costs

[0123] Construct a ladder-type carbon trading mechanism model, the model is as follows:

[0124]

[0125] Where: E IES 、E e,buy 、E BSC and E GB They are the total quota of AIES, external power purchase quota, BSC system quota and GB quota; e , χ g and χ b are the carbon emission quota coefficients per unit of electricity, natural gas and biomass gas consumption; E IES,a 、E e,buy,a , P BSC,b,a and P GB,h,a are the actual carbon emissions of IES, power purchase from higher authorities, BSC system and GB; E MR,a is the amount of CO2 actually absorbed by MR; E IES,t is the carbon emission trading amount; H is the coefficient corresponding to different carbon emission ranges;

[0126] 4) Operation and maintenance costs

[0127]

[0128] Where: β j is the unit operation and maintenance cost of the jth type of equipment; P j,t is the output power of the jth device at time t; j is the type of device;

[0129] 5) Park compensation costs

[0130] C fill =F shift +F tran +F cut (32);

[0131] Step 3.2: Constraints

[0132] The constraints include wind and solar power output constraints, energy purchase constraints, power balance constraints, equipment energy constraints and energy storage constraints; the details are as follows:

[0133] 1) Wind and solar power output constraints

[0134]

[0135] Where: and They are the upper limits of the output of photovoltaic units and wind turbine units respectively;

[0136] P pv,t is the photovoltaic power at time t; P wt,t is the fan power at time t;

[0137] 2) Restrictions on purchasing electricity and gas

[0138]

[0139] Where: and They are the upper and lower limits of the purchased power respectively; and are the upper and lower limits of gas purchase power respectively; P e,buy,t P is the power purchased from the upper grid at time t; g,buy,t The gas power purchased from the superior gas network at time t;

[0140] 3) Electric power balance constraints

[0141]

[0142] Where: and They are respectively the electric loads that can be translated, transferred and reduced at time t;

[0143] 4) Thermal power balance constraints

[0144]

[0145] Where: P farm,h,t is the heating power of the breeding plant at time t; and They are respectively the heat load that can be translated and reduced at time t;

[0146] 5) Cold power balance constraint

[0147] P BSC,c,t +P ERU,c,t +P c,dis,t =P load,c,t +P c,cha,t (37);

[0148] 6) Natural gas power balance constraints

[0149] P g,buy,t +P MR,g,t =P GB,g,t (38);

[0150] 7) Hydrogen power balance constraints

[0151]

[0152] The present invention provides a cooling, heating and electricity optimization scheduling method for an agricultural park comprehensive energy system based on biomass-solar energy coupling, which has the following technical effects:

[0153] 1) Due to the insufficient supply of electricity, heat and cold energy in the comprehensive energy system of some agricultural parks, carbon emissions and operating costs remain high, and the phenomenon of abandoning wind and light is relatively serious, which has greatly curbed the development of planting and breeding industries in agricultural parks, and has a great impact on the stability of the comprehensive energy system of agricultural parks. To this end, step 1 of the present invention constructs a biomass-solar coupling system by combining the waste biomass generated in the agricultural park with a solar collector, and introduces a power-to-gas P2G device and a carbon capture CCS device. The power-to-gas P2G device produces hydrogen by electrolyzing water, which can effectively absorb new energy sources such as wind and light. The carbon capture CCS device can capture carbon dioxide and produce methane for the methane reactor, which can effectively reduce the carbon emissions of the agricultural park. Finally, an agricultural park comprehensive energy system considering biomass-solar coupling is constructed, which can not only effectively alleviate the problem of insufficient energy supply in the comprehensive energy system of the agricultural park, but also greatly improve the low-carbon economic benefits of the agricultural park.

[0154] 2) Since the agricultural park load is an adjustable load, it has not been utilized. Therefore, step 2 of the present invention analyzes the electric load and thermal load of the greenhouse in the agricultural park, the electric load and thermal load of the breeding plant, establishes an agricultural park flexible load model, and allows the agricultural park load to participate in the grid regulation, which can effectively alleviate the peak-to-valley difference of the grid and improve the low-carbon economic benefits of the comprehensive energy system of the agricultural park.

[0155] 3) To seek a low-carbon economic operation plan for the comprehensive energy system of the agricultural park. To this end, step 3 of the present invention establishes a cooling, heating and electricity optimization scheduling model for the comprehensive energy system of the agricultural park considering biomass-solar energy coupling, and introduces a step-by-step carbon trading mechanism to further limit the carbon emissions of the agricultural park. The model can effectively seek the optimal operation plan for the comprehensive energy system of the agricultural park.

[0156] 4) Regarding the defects mentioned in the background technology: the AIES model structure of the agricultural park integrated energy system is relatively simple, ignoring the consumption of wind and solar energy and the mutual conversion between multiple energy sources, resulting in the failure to further improve the performance of AIES;

[0157] The present invention introduces a power-to-gas P2G device, a carbon capture CCS device, an electric boiler EB device, an electric refrigerator ERU device and a gas boiler GB device into the comprehensive energy system of the agricultural park. The power-to-gas P2G device produces hydrogen by electrolyzing water, and can effectively absorb new energy sources such as wind and light. The carbon capture CCS device can capture carbon dioxide and produce methane for the methane reactor, which can effectively reduce the carbon emissions of the agricultural park. The electric boiler EB device can convert electrical energy into thermal energy, the electric refrigerator ERU can realize the conversion of electrical energy into cold energy, and the gas boiler can realize the conversion of natural gas into thermal energy, realizing the mutual conversion between energy sources, which is conducive to improving the low-carbon economic benefits of the agricultural park.

[0158] 5) Regarding the defects mentioned in the background technology: Although the above literature has established a relatively complete demand response model, it is still necessary to analyze the load type specifically for different IES loads and select the appropriate demand response mechanism according to the load type;

[0159] The present invention takes into account that the load characteristics of agricultural parks are different from conventional loads, and conventional price-based demand response and alternative demand response are not applicable. Therefore, the present invention deeply analyzes the electrical load and thermal load of greenhouses and breeding farms in agricultural parks, establishes a flexible load model for agricultural parks, and allows agricultural park loads to participate in grid regulation without affecting the normal operation of agricultural parks, thereby reducing the peak-to-valley difference of the grid and effectively reducing the operating cost of the comprehensive energy system of agricultural parks.

[0160] 6) Regarding the defects mentioned in the background technology: The above literature studies the utilization scenarios of biomass energy in IES, but does not consider the source of biomass

[0161] The present invention utilizes waste biomass generated in agricultural parks in combination with solar collectors to construct a biomass-solar coupling system, which can effectively realize the reuse of waste materials and reduce system operating costs.

[0162] 7) In response to the defects mentioned in the background technology: AIES considering biomass energy and agricultural flexible loads has been established, but the system structure is relatively simple and the absorption capacity is poor.

[0163] The present invention introduces power-to-gas P2G equipment, carbon capture CCS equipment, electric boiler EB equipment, electric refrigerator ERU equipment, gas boiler GB equipment and electric heat and cold energy storage equipment into the comprehensive energy system of the agricultural park. The power-to-gas P2G equipment produces hydrogen by electrolyzing water, which can effectively absorb new energy sources such as wind and light. The carbon capture CCS equipment can capture carbon dioxide and produce methane for the methane reactor, which can effectively reduce the carbon emissions of the agricultural park. The electric boiler EB equipment can convert electrical energy into thermal energy, the electric refrigerator ERU can realize the conversion of electrical energy into cold energy, and the gas boiler can realize the conversion of natural gas into thermal energy, realizing the mutual conversion between energy sources. The electric heat and cold energy storage equipment can effectively realize the time shift of energy, which is conducive to improving the low-carbon economic benefits of the agricultural park. BRIEF DESCRIPTION OF THE DRAWINGS

[0164] The present invention will be further described below in conjunction with the accompanying drawings and embodiments:

[0165] Figure 1 This is the AIES framework diagram of BSC.

[0166] Figure 2 This is the BSC system diagram.

[0167] Figure 3 It provides wind and solar output as well as electricity, heating and cooling load diagrams.

[0168] Figure 4 To optimize the flexible electricity load distribution map of the former agricultural park.

[0169] Figure 5 To optimize the flexible heat load distribution map of the former agricultural park.

[0170] Figure 6 To optimize the flexible electric load distribution map of the agricultural park.

[0171] Figure 7 Flexible heat load distribution map for optimized agricultural park.

[0172] Figure 8 Comparison chart of flexible electric load in agricultural park before and after optimization.

[0173] Fig. 9 Comparison chart of flexible heat load in agricultural park before and after optimization.

[0174] Fig.10 This is the electric power balance diagram for scenario 1.

[0175] Fig.11 This is the thermal power balance diagram for scenario 1.

[0176] Fig.12 This is the cold power balance diagram for scenario 1. DETAILED DESCRIPTION

[0177] A cooling, heating and electricity optimization scheduling method for an agricultural park integrated energy system based on biomass-solar energy coupling comprises the following steps:

[0178] Step 1: Construct an integrated energy system for the agricultural park based on biomass-solar energy coupling, introduce power-to-gas and carbon capture coupling equipment, multi-energy conversion equipment and energy storage equipment, and establish models for each device.

[0179] (1) Biomass-solar coupling device model

[0180] 1) Biomass gasification model

[0181] After being heated by the preheater, the biomass enters the gasification tank. Its gas production rate is related to the temperature. The biomass gas production rate and biomass output model are as follows:

[0182]

[0183] Where: η b,t and T t are the gas production rate and temperature of the biomass gas pool at time t; T0 is the most suitable temperature of the biomass gas pool, which is generally 35°C; P BSC,b,t and m bio,t are the input power and biomass mass flow rate of biomass at time t respectively; LHV is the lower heating value of biomass.

[0184] 2) Biomass gasification pool model

[0185] The gas production efficiency of the biomass gasification pool is closely related to the temperature in the pool and the ambient temperature. The present invention considers that the solar collector and the heat exchanger are combined to provide energy to maintain the appropriate temperature of the biomass gasification pool. The heat balance formula and heat dissipation model in the biomass gasification pool are as follows:

[0186]

[0187] Where: ρ and C p is the density and specific heat capacity of biomass materials; V d is the volume of the biomass gasification tank; HRT is the time the material is in the biomass gasification tank; T amb,t is the ambient temperature at time t; U h and S dis the total heat transfer coefficient and total heat dissipation area of ​​the biomass gasification pool; P GT,h,t and P GT,loss,t They are the energy and heat dissipation required by the biomass gasification pool at time t respectively.

[0188] 3) Solar collector

[0189] The solar collector has the highest output at noon, but the outside temperature is high at this time, and the energy required by the biomass gasification pool is less, resulting in a waste of heat energy. Therefore, the present invention considers that the solar collector gives priority to supplying heat to the biomass gasification pool, and the excess heat energy can be directly shared with the heat load. The solar collector model is as follows:

[0190] P TC,t =n TC η TC,t G TC,t Q TC (3);

[0191] Where: P TC,t , η TC,t and G TC,t is the output power, conversion efficiency and light radiation intensity of the solar collector at time t; n TC is the number of collectors; Q TC is the area of ​​a single collector.

[0192] 4) Biomass-solar coupled BSC system model

[0193] Part of the biomass gas is burned in an internal combustion engine to generate electricity, and part of it is used to generate heat through a heat exchanger. Part of the generated heat energy meets the heat load, part is supplied to the gasification pool, and the other part is supplied to the absorption refrigeration machine for cooling. The BSC system model is as follows:

[0194]

[0195] Where: P BSC,e,t , P BSC,h,t and P BSC,c,t are the electrical power, thermal power and cooling power output by BSC at time t respectively; P BSC,b,t is the total power input to BSC at time t; P HRB,h,t P is the heat energy supplied to the refrigerator at time t; HRB,tc,t P is the heat energy supplied to the gasification pool; TC,h,t The thermal energy that supplies the heat load to the solar collector at time t; η BSC,e , η BSC,h and η BSC,c are the electrical efficiency, thermal efficiency and cooling efficiency of BSC output respectively; P GT,h,t is the energy required by the biomass gasification pool at time t.

[0196] The operation constraints and ramp constraints of the BSC system are as follows:

[0197]

[0198] Where: and They are the upper and lower limits of the BSC system input power respectively; and The upper and lower limits of the BSC system climbing power; and The upper and lower limits of the input absorption chiller power; and Input the upper and lower limits of the absorption chiller's ramp power; and They are the upper and lower limits of the heat energy delivered to the gasification pool; and They are respectively the upper and lower limits of the climbing power of the transport gasification pool.

[0199] (2) Power-to-gas (P2G) and carbon capture (CCS) coupling equipment model

[0200] P2G and CCS coupling equipment can absorb excess wind and solar energy and reduce CO2 emissions. The P2G and CCS coupling model is as follows:

[0201] 1) Electrolyzer EL

[0202]

[0203] Where: P EL,e,t is the electrical energy input to EL at time t; is the hydrogen energy of EL input at time t; η EL is the energy conversion efficiency of EL; are the upper and lower limits of the input EL power, respectively; They are the upper and lower limits of EL climbing power respectively.

[0204] 2) Methane Reactor MR

[0205]

[0206] Where: is the hydrogen energy input into MR at time t; P MR,g,t is the gas power output by MR at time t; η MR is the energy conversion efficiency of MR; are the upper and lower limits of the hydrogen power input to MR respectively; They are the upper and lower limits of MR climbing power respectively.

[0207] 3) Hydrogen fuel cell HFC

[0208]

[0209] Where: is the hydrogen power input to HFC at time t; P HFC,e,t is the electric power output of HFC at time t; η HFC The efficiency of energy conversion of HFC; are the upper and lower limits of the input HFC hydrogen power, respectively; They are the upper and lower limits of HFC climbing power respectively.

[0210] 4) Carbon capture (CCS)

[0211] Considering the problem of coupling failure between P2G and CCS due to insufficient wind and solar energy output, a CO2 storage tank is introduced into CCS to strengthen the coupling between P2G and CCS. CO2 mainly comes from gas boilers and BSC systems. The CCS model is as follows:

[0212]

[0213] Where: P CCS,t , P CCS,f,t and P CCS,o,t are the total energy consumption, fixed energy consumption and operating energy consumption of CCS at time t respectively; is the mass of CO2 captured by CCS at time t; ε CCS is the energy consumption coefficient of CCS; and are the CO2 masses produced by GB and BSC at time t; ω CCS Efficiency of capturing CO2 for CCS; and are the amount of CO2 and the amount of CO2 stored by CCS required by MR at time t respectively.

[0214] Among them: The operating power constraint and climbing power constraint of CCS are as follows:

[0215]

[0216] Where: are the upper and lower limits of CCS energy consumption respectively; They are the upper and lower limits of CCS climbing energy consumption respectively.

[0217] (3) Energy conversion device model

[0218] Energy conversion equipment mainly includes EB, ERU and GB. EB is used to convert electrical energy into thermal energy, ERU converts electrical energy into cold energy, and GB burns natural gas to generate thermal energy. Its model is as follows:

[0219] 1) Electric boiler EB

[0220]

[0221] Where: P EB,e,t is the electric power consumed by EB at time t; P EB,h,t is the thermal power generated by EB at time t; η EB is the heating efficiency of EB; They are the upper and lower limits of the electric power consumed by EB respectively; It is the upper and lower limits of EB's climbing power.

[0222] 2) Electric Refrigerator ERU

[0223]

[0224] Where: P ERU,e,t is the electric energy consumed by ERU at time t; P ERU,c,t is the cooling energy generated by ERU at time t; η ERU is the ERU cooling efficiency; The upper and lower limits of the input ERU electric power; They are the upper and lower limits of ERU climbing power respectively.

[0225] 3) Gas boiler GB

[0226]

[0227] Where: P GB,g,t , P GB,h,t They represent the input gas power and output thermal power of GB at time t respectively; η GB is GB energy conversion efficiency; The upper and lower limits of GB input power; These are the upper and lower limits of GB’s climbing power.

[0228] (4) Energy storage equipment model

[0229] Multi-energy storage mainly consists of electrical energy storage, thermal energy storage, cold energy storage and hydrogen energy storage. Its general model is as follows:

[0230] 1) Charging and discharging power and state constraints:

[0231]

[0232] Where: x is the type of energy storage device, e, h, c and H2 represent electric, heat, cold and hydrogen energy storage respectively; P x,cha,t , P x,dis,t Respectively represent the charging and discharging power of the energy storage device x at time t; I x,cha,t ,I x,dis,t They represent the charging and discharging states of the energy storage device x at time t respectively; and Respectively represent the upper and lower limits of the charging power of the energy storage device x; and They respectively represent the upper and lower limits of the energy storage device x's discharge power.

[0233] 2) Energy storage state continuity constraints:

[0234]

[0235] Where: S x,t is the storage capacity of energy storage device x at time t; x is the self-loss coefficient of energy storage device x; η x,cha , η x,dis are the charging and discharging efficiencies of energy storage device x respectively; is the upper and lower limits of energy storage capacity; S x,1 is the storage capacity of energy storage device x at time 1; S x,24 is the storage capacity of energy storage device x at 24 hours.

[0236] Step 2: Based on the load characteristics of the agricultural park, establish a flexible load model for the agricultural park.

[0237] Considering that the load characteristics of agricultural parks are different from conventional loads, in order to deeply consider the impact of agricultural park loads on AIES, this paper analyzes the load characteristics of greenhouses and breeding farms in detail. The specific model is established as follows:

[0238] (1) Agricultural park load model

[0239] 1) Greenhouse electrical load

[0240] The electrical load of the greenhouse mainly includes electric irrigation machines, ventilators, roller shutter machines, plant supplementary lights and crop dryers. The model is as follows:

[0241]

[0242] Where: P gh,e,t is the power consumption of the greenhouse at time t; P pump,t , P fan,t , P driver,t , P light,t and P ldryer,t are the rated power of a single electric irrigation machine, ventilator, roller shutter machine, plant supplementary light and crop dryer respectively; d pump,t d fan,t d driver,t d light,t and d dryer,tIt is a 0-1 variable, corresponding to the working status of the electric irrigation machine, ventilator, roller shutter machine, plant fill light and crop dryer; N1 is the number of electric irrigation machines; N2 is the number of ventilators; N3 is the number of roller shutter machines; N4 is the number of plant fill lights; N5 is the number of crop dryers.

[0243] 2) Greenhouse heat load

[0244]

[0245] Where: T gh,t is the greenhouse temperature at time t; T gh,t+1 is the greenhouse temperature at time t+1; P gh,su,t , P gh,in,t and P gh,loss,t are the heat supply, heat production and heat dissipation of the greenhouse at time t; ρ air 、c air and ν gh are respectively the air density, specific heat capacity and greenhouse volume of the greenhouse. gh,loss,t Includes heat losses through walls, floors and air movement.

[0246] 3) Electricity load of breeding farm

[0247] The heating model of a breeding farm is similar to that of a greenhouse. The electrical load of a breeding farm is mainly composed of ventilation system, feed feeding system and waste treatment system. The heating model of a breeding farm is as follows:

[0248]

[0249] Where: P farm,e,t is the power consumption of the breeding farm at time t; P t air , P t feed and P t waste are the power consumption of ventilation system, feeding system and waste treatment system at time t; β t air , β t feed and β t waste are 0-1 variables, indicating whether the ventilation system, feeding system and waste treatment system are in working condition at time t; M1 is the number of ventilation systems; M2 is the number of feeding systems; M3 is the number of waste treatment systems.

[0250] The feed feeding system builds a farm feeding system that integrates feed crusher, feed mixer and automatic feeder. The electrical load model of the feed feeding system is as follows:

[0251]

[0252] Where: P t feed is the output of the feeding system at time t; and are the rated power of feed crusher, feed mixer and automatic feeder respectively; α cut , α mix and α rel is a 0-1 variable, indicating the working status of the feed crusher, feed mixer and automatic feeder; η i mix and Respectively represent the working efficiency of feed crusher, feed mixer and automatic feeder.

[0253] The waste treatment system is mainly composed of sewage treatment equipment and garbage crushing equipment. The electrical load model of the waste treatment system is as follows:

[0254]

[0255] Where: g and eP t duc are the power of treating sewage and park garbage at time t, The power consumption of the waste treatment system;

[0256] (2) Analysis of flexible load characteristics in agricultural parks

[0257] According to the load characteristics of agricultural parks, the electric load of agricultural parks can be divided into reducible electric load, shiftable electric load and transferable electric load. Considering that users are more sensitive to heat load, the heat load of greenhouses only considers reducible heat load and shiftable heat load. In addition, load adjustment compensation can be provided for the park to improve the enthusiasm of the park.

[0258] 1)Transferable load

[0259] In the present invention, the shiftable load model, the transferable load model and the reducible load model are all combinations of electrical loads and thermal loads, and are general models. For example, the shiftable load refers to a combination of a shiftable electrical load and a shiftable thermal load.

[0260] The simulation of the present invention takes into account the translation, transfer and reduction of the electric load; the thermal load only takes into account the translation and reduction, and considering that the agricultural park is sensitive to the thermal load, the transfer of the thermal load is not considered.

[0261] The movable loads in agricultural parks mainly include movable electrical loads and movable thermal loads. The movable loads have continuous energy consumption and need to be moved in whole sections, such as electric irrigation machines, automatic feeders, etc. The model is as follows:

[0262]

[0263] Where: and L shift are the loads before and after translation respectively; S shift is the set of starting moments of the translatable load; They are respectively S ,t S+1 ,t D The load of the moment; They are respectively after translation at τ, τ+1, τ+t D -1 time load; [t sh- ,t sh+ ] is the shiftable interval; t s is the starting period; t D For a continuous period.

[0264] The cost of the park to be compensated after the translation F shift for:

[0265]

[0266] Where: Price compensation for unit load shifting; For L shift The sum of translation loads; t sh- is the starting time of load translation; t sh+ -t D +1 is the starting time after the load is translated.

[0267] 2) Transferable load

[0268] Transferable electrical loads are relatively flexible and do not require continuous power consumption, but the total load must remain unchanged before and after the transfer, such as roller shutters, plant fill lights, etc. The model is as follows:

[0269]

[0270] Where: are the upper and lower limits of the transferable load respectively; β t is a 0-1 variable, indicating whether to transfer at time t; P t tran* , P t tran are the loads at time t before and after the transfer respectively; [t tr- ,t tr+ ] is the transfer interval.

[0271] The cost of the park to be compensated after the transfer F tran for:

[0272]

[0273] Where: The compensation price for load transfer.

[0274] 3) Load reduction possible

[0275] The load that can be reduced is to reduce part of the load without affecting the normal operation of the park, such as crop dryers, feed crushers, etc. The model is as follows:

[0276]

[0277] Where: P t cut* , P t cut are the loads before and after the reduction at time t; γ t is a 0-1 variable, indicating whether it is cut at time t; is the maximum continuous reduction time; N max is the maximum number of reductions.

[0278] Costs to be compensated to the park after reduction F cut for:

[0279]

[0280] Where: The compensation price for load reduction.

[0281] Step 3: Establish an optimal scheduling model for cooling, heating and electricity of the agricultural park integrated energy system based on biomass-solar energy coupling, and introduce a step-by-step carbon trading mechanism to limit carbon emissions.

[0282] (1) Objective function

[0283] The present invention comprehensively considers the energy purchase cost C of the agricultural park integrated energy system AIES buy , wind and solar cost C cut , Carbon trading costs Operation and maintenance cost C om and the park compensation cost C fill , construct with a total cost C total The minimum low-carbon economy targets are as follows:

[0284]

[0285] 1) Energy purchase cost

[0286] The energy purchase costs mainly include electricity purchase and gas purchase costs. The model is as follows:

[0287]

[0288] Where: α e and α g are the unit prices of electricity and gas respectively; P e,buy,t , P g,buy,t are the power of electricity and gas purchased at time t respectively; T is the time period.

[0289] 2) Cost of curtailing wind and solar power

[0290]

[0291] Where: wt , δ pv are the penalty factors for wind and solar abandonment, respectively; P wt,cut,t , P pv,cut,t are the wind power and solar power abandoned at time t respectively.

[0292] 3) Carbon trading costs

[0293] The present invention establishes a ladder-type carbon trading mechanism model, which is as follows:

[0294]

[0295] Where: E IES 、E e,buy 、E BSC and E GB They are the total quota of AIES, external power purchase quota, BSC system quota and GB quota; e , χ g and χ b E are the carbon emission quota coefficients per unit of electricity, natural gas and biomass gas consumption respectively. IES,a 、E e,buy,a , P BSC,b,a and P GB,h,a are the actual carbon emissions of IES, power purchase from higher authorities, BSC system and GB; E MR,a is the amount of CO2 actually absorbed by MR; E IES,t is the carbon emission trading amount; H is the coefficient corresponding to different carbon emission ranges.

[0296] 4) Operation and maintenance costs

[0297]

[0298] Where: β j is the unit operation and maintenance cost of the jth type of equipment; P j,t is the output power of the jth device at time t; j is the type of device.

[0299] 5) Park compensation costs

[0300] C fill =F shift +F tran +F cut (32);

[0301] (2) Constraints

[0302] The model constraints of the present invention mainly include wind and solar power output constraints, energy purchase constraints, power balance constraints, equipment energy constraints and energy storage constraints. The details are as follows:

[0303] 1) Wind and solar power output constraints

[0304]

[0305] Where: and are the upper limits of the output of photovoltaic units and wind turbine units, P pv,t is the photovoltaic power at time t; wt,t The fan power at time t;

[0306] 2) Restrictions on purchasing electricity and gas

[0307]

[0308] Where: and They are the upper and lower limits of the purchased power respectively; and are the upper and lower limits of gas purchase power, P e,buy,t is the power P purchased from the upper grid at time t g,buy,t The gas power purchased from the superior gas network at time t;

[0309] 3) Electric power balance constraints

[0310]

[0311] Where: and They are the shiftable electric load, transferable electric load and reducible electric load at time t respectively.

[0312] 4) Thermal power balance constraints

[0313]

[0314] Where: P farm,h,t is the heating power of the breeding plant at time t; and They are the heat load that can be shifted and the heat load that can be reduced at time t respectively.

[0315] 5) Cold power balance constraints

[0316] PBSC,c,t +P ERU,c,t +P c,dis,t =P load,c,t +P c,cha,t (37);

[0317] 6) Natural gas power balance constraints

[0318] P g,buy,t +P MR,g,t =P GB,g,t (38);

[0319] 7) Hydrogen power balance constraints

[0320]

[0321] The present invention selects an agricultural park in Gansu, China as an example for calculation and analysis, and optimizes the scheduling with a cycle of 24 hours a day, and the time interval is 1 hour. The BSC coupling equipment parameters are shown in Table 1; the biomass gasification pool parameters are shown in Table 2; the agricultural park flexible load parameters are shown in Table 3; the wind power, photovoltaic output, and electricity, heat and cooling load data are shown in Table 3. Figure 3 This example uses the CPLEX solver for optimization.

[0322] Table 1 BSC coupling equipment parameters

[0323]

[0324] Table 2 Biomass gasification pool parameters

[0325]

[0326] Table 3 Classification of characteristics of agricultural park equipment

[0327]

[0328]

[0329] In order to verify the rationality of the model considering the flexible load of the agricultural park and the coupling model of CCS and P2G in the model of the present invention, as well as the superiority of the BSC coupling system over the combined heating and cooling system using natural gas as raw material, the scheduling results of the following four scenarios are selected for comparative analysis:

[0330] Scenario 1: Considering BSC system participating in AIES, flexible load in agricultural park, and coupling of CCS and P2G;

[0331] Scenario 2: Considering the BSC system participating in AIES, CCS is coupled with P2G, and the flexible load of the agricultural park is not considered;

[0332] Scenario 3: Considering BSC coupling system participating in AIES, agricultural park flexible load, without considering P2G and CCS;

[0333] Scenario 4: Consider the traditional combined cooling, heating and power system participating in AIES, the flexible load of the agricultural park, and the coupling of CCS and P2G.

[0334] (1) Economic and carbon emission analysis

[0335] The optimization scheduling results of each scenario are shown in Table 3.

[0336] It can be seen from Table 3 that compared with scenario 1, the energy purchase cost of scenario 2 increased by 342.3 yuan, an increase of 245.9%; the carbon trading cost increased by 76 yuan, an increase of 5.5%, and the carbon emissions increased by 189 kg; the total cost increased by 148.2 yuan. This is because scenario 1 optimized the flexible load of the agricultural park, reduced, translated and transferred part of the load, and overall reduced part of the load while ensuring the normal operation of all parts of the agricultural park, and reduced the peak-to-valley difference of the load, which is conducive to the stable operation of the AIES economy.

[0337] As shown in Table 3, compared with Scenario 1, the carbon trading cost of Scenario 3 increased by 40.8 yuan and the carbon emissions increased by 131.9 kg. This is because Scenario 1 introduced P2G and CCS equipment into AIES, which can absorb excess wind and solar energy and reduce CO2 emissions.

[0338] It can be seen from Table 3 that compared with Scenario 1, the gas purchase cost of Scenario 4 increased by 80.5 yuan, the carbon trading cost increased by 240.8 yuan, the carbon emissions increased by 678 kg, and the total cost increased by 369.3 yuan, an increase of 16.9%. This is because compared with the traditional cogeneration system in Scenario 4 that uses natural gas as raw material, the BSC system in Scenario 1 uses biomass as the main energy source, which can fully utilize waste, reduce energy consumption and CO2 emissions, and reduce system costs.

[0339] (2) Analysis of flexible loads in agricultural parks

[0340] By comparing Scenario 1 and Scenario 2, the impact of optimizing the flexible electrical and thermal loads of the agricultural park on the results is analyzed.

[0341] Depend on Figure 6 and Figure 8 It can be seen that after optimization, the electric load that can be reduced in the time period (12:00-20:00) is reduced, the shiftable electric load 1 and the shiftable electric load 2 are shifted from the load peak period (12:00, 20:00) to the load valley period (5:00-8:00), and the transferable electric load is transferred from the load peak period (1:00-4:00) to the valley period (4:00-8:00), which is conducive to alleviating the peak-valley difference of the electric load.

[0342] Depend on Figure 7 and Fig. 9 It can be seen that the heat load that can be reduced is reduced in the time period (11:00-13:00), and the heat load that can be transferred is transferred from the peak load period (18:00-20:00) to the time period (11:00-13:00), which effectively alleviates the peak-to-valley difference of the heat load and improves the economic benefits of the system.

[0343] Depend on Fig.10 , Fig.11 and Fig.12 It can be seen that when the AIES wind and solar power output is insufficient, the BSC system, as a supplementary energy source, can not only effectively alleviate the system's energy shortage, but also fully utilize waste and reduce system operating costs.

[0344] (3) Comprehensive evaluation of BSC system access to AIES

[0345] In order to analyze in detail the difference between the BSC system in scenario 1 and the traditional combined cooling, heating and power system in scenario 4, this paper introduces the primary energy saving rate (PESR), CO2 emission saving rate (CEER) and total cost saving rate (TCSR) as the evaluation indicators of the system from the three aspects of economy, energy and environment. The detailed model refers to the reference "Research on Two-stage Robust Capacity Configuration of Biomass Gas-Solar-Wind Integrated Energy System [D]. Shandong University, 2022.". Among them, P PEC1 , P PEC4 、E CDE1 、E CDE4 , C COST1 , C COST4 They represent the total primary energy consumption (PEC), CO2 emissions (CDE) and total cost (total cost) of scenario 1 and scenario 4 in one day respectively.

[0346] Table 5 Evaluation indicators

[0347]

[0348]

[0349] It can be seen from Table 5 that although the primary energy consumption of scenario 1 is 16.2% higher than that of scenario 4, its CO2 emissions are reduced by 13.3% and the total cost is reduced by 14.5%. By utilizing biomass waste, the system operating cost and CO2 emissions can be effectively reduced. Therefore, the BSC system has better characteristics than the traditional cogeneration system in participating in AIES.

Claims

1. A cooling, heating and electricity optimization scheduling method for an agricultural park integrated energy system based on biomass-solar energy coupling, characterized in that: The following steps are involved: Step 1: Construct an integrated energy system for agricultural parks based on biomass-solar energy coupling; Step 2: Based on the load characteristics of the agricultural park, a flexible load model of the agricultural park is constructed; Step 3: Construct an optimal scheduling model for cooling, heating and electricity of the agricultural park integrated energy system based on biomass-solar energy coupling, and introduce a step-by-step carbon trading mechanism model to limit carbon emissions.

2. According to claim 1, a method for optimizing the dispatch of cooling, heating and electricity of an agricultural park integrated energy system based on biomass-solar energy coupling, characterized in that: In step 1, a comprehensive energy system for agricultural parks based on biomass-solar energy coupling is constructed, which specifically includes: (1) Construct a biomass-solar coupling device model; (2) Construct a power-to-gas (P2G) and carbon capture (CCS) coupling equipment model; (3) Construct an energy conversion device model; (4) Construct an energy storage device model.

3. The cooling, heating and electricity optimization scheduling method of the agricultural park integrated energy system based on biomass-solar energy coupling according to claim 2 is characterized by: (1) The biomass-solar coupling device model is constructed, which specifically includes: 1) Constructing a biomass gasification model After being heated by the preheater, the biomass enters the gasification tank. Its gas production rate is related to the temperature. The biomass gas production rate and biomass output model are as follows: Where: η b,t and T t are the gas production rate and temperature of the biomass gas pool at time t; T0 is the most suitable temperature of the biomass gas pool, which is generally 35°C; P BSC,b,t and m bio,t are the biomass input power and biomass mass flow rate at time t respectively; LHV is the lower heating value of biomass; 2) Constructing a biomass gasification pool model The energy to maintain the appropriate temperature of the biomass gasification pool is provided by the solar collector and the heat exchanger. The heat balance formula and heat dissipation model in the biomass gasification pool are as follows: Where: ρ and C p is the density and specific heat capacity of biomass materials; V d is the volume of the gasification pool; HRT is the time the material is in the gas pool; T amb,t is the ambient temperature at time t; U h and S d is the total heat transfer coefficient and total heat dissipation area of ​​the gasification pool; P GT,h,t and P GT,loss,t are the energy and heat dissipation required by the gasification pool at time t respectively; 3) Construct a solar collector model The solar collector gives priority to supplying heat to the biomass gasification pool, and the excess heat can be directly shared with the heat load; the solar collector model is as follows: P TC,t =n TC or TC,t G TC,t Q TC (3); Where: P TC,t , η TC,t and G TC,t is the output power, conversion efficiency and light radiation intensity of the solar collector at time t; n TC is the number of collectors; Q TC is the area of ​​a single collector; 4) Constructing a biomass-solar coupled BSC system model Part of the biomass gas is burned in an internal combustion engine to generate electricity, and part of it is used to generate heat through a heat exchanger. Part of the generated heat energy meets the heat load, part is supplied to the biomass gasification pool, and the other part is supplied to the absorption refrigeration machine for cooling; the biomass-solar coupled BSC system model is as follows: Where: P BSC,e,t , P BSC,h,t and P BSC,c,t are the electrical power, thermal power and cooling power output by BSC at time t respectively; P BSC,b,t is the total power input to BSC at time t; P HRB,h,t P is the heat energy supplied to the refrigerator at time t; HRB,tc,t P is the heat energy supplied to the gasification pool; TC,h,t The thermal energy that supplies the heat load to the solar collector at time t; η BSC,e , η BSC,h and η BSC,c are the electrical, thermal and cooling efficiencies of BSC output respectively; P GT,h,t is the energy required by the biomass gasification pool at time t; Among them, the operation constraints and ramp constraints of the BSC system are as follows: Where: and They are the upper and lower limits of the BSC system input power respectively; and The upper and lower limits of the BSC system climbing power; and The upper and lower limits of the input absorption chiller power; and Input the upper and lower limits of the absorption chiller's ramp power; and They are the upper and lower limits of the heat energy delivered to the gasification pool; and They are respectively the upper and lower limits of the climbing power of the transport gasification pool.

4. According to claim 2, a method for optimizing the dispatch of cooling, heating and electricity of an agricultural park integrated energy system based on biomass-solar energy coupling is characterized by: (2) The power-to-gas (P2G) and carbon capture (CCS) coupling equipment model is constructed, including: The power-to-gas (P2G) and carbon capture (CCS) coupling equipment can absorb excess wind and solar energy and reduce CO2 emissions. The power-to-gas (P2G) and carbon capture (CCS) coupling model is as follows: 1) Electrolyzer EL Where: P EL,e,t is the electrical energy input to EL at time t; is the hydrogen energy of EL input at time t; η EL is the energy conversion efficiency of EL; are the upper and lower limits of the input EL power, respectively; They are the upper and lower limits of EL climbing power respectively; 2) Methane Reactor MR Where: is the hydrogen energy input into MR at time t; P MR,g,t is the gas power output by MR at time t; η MR is the energy conversion efficiency of MR; are the upper and lower limits of hydrogen power input to MR, respectively; They are the upper and lower limits of MR climbing power respectively; 3) Hydrogen fuel cell HFC Where: is the hydrogen power input to HFC at time t; P HFC,e,t is the HFC output power at time t; η HFC The efficiency of HFC energy conversion; are the upper and lower limits of the input HFC hydrogen power, respectively; They are the upper and lower limits of HFC climbing power respectively; 4) Carbon capture CCS Considering the problem of coupling failure between P2G and CCS due to insufficient wind and solar energy output, a CO2 storage tank is introduced into the carbon capture CCS to strengthen the coupling between power-to-gas P2G and carbon capture CCS; CO2 mainly comes from gas boilers and BSC systems; the carbon capture CCS model is as follows: Where: P CCS,t , P CCS,f,t and P CCS,o,t are the total energy consumption, fixed energy consumption and operating energy consumption of CCS at time t respectively; is the mass of CO2 captured by CCS at time t; ε CCS is the energy consumption coefficient of CCS; and are the CO2 masses produced by GB and BSC at time t; ω CCS Efficiency of capturing CO2 for CCS; and The amount of CO2 provided and the amount of CO2 stored by CCS required by MR at time t, respectively; Among them: The operating power constraint and climbing power constraint of CCS are as follows: Where: They are the upper and lower limits of CCS energy consumption respectively; They are the upper and lower limits of CCS climbing energy consumption respectively.

5. According to claim 2, a method for optimizing the dispatch of cooling, heating and electricity of an agricultural park integrated energy system based on biomass-solar energy coupling is characterized by: (3) Construct an energy conversion device model, including: The energy conversion equipment includes electric boiler EB, electric refrigerator ERU and gas boiler GB; electric boiler EB is used to convert electrical energy into heat energy, electric refrigerator ERU converts electrical energy into cold energy, and gas boiler GB burns natural gas to generate heat energy; the models are as follows: 1) Electric boiler EB Where: P EB,e,t is the electric power consumed by EB at time t; P EB,h,t is the thermal power generated by EB at time t; η EB is the heating efficiency of EB; They are the upper and lower limits of EB power consumption respectively; The upper and lower limits of EB's climbing power; 2) Electric Refrigerator ERU Where: P ERU,e,t is the electric energy consumed by ERU at time t; P ERU,c,t is the cooling energy generated by ERU at time t; η ERU is the ERU cooling efficiency; The upper and lower limits of the input ERU electric power; They are the upper and lower limits of ERU climbing power respectively; 3) Gas boiler GB Where: P GB,g,t , P GB,h,t They represent the input gas power and output thermal power of GB at time t respectively; η GB is GB energy conversion efficiency; The upper and lower limits of GB input power; These are the upper and lower limits of GB’s climbing power.

6. The method for optimizing the dispatch of cooling, heating and electricity of an agricultural park integrated energy system based on biomass-solar energy coupling according to claim 2 is characterized by: (4) Construct the energy storage device model, including: Multi-energy storage includes electric energy storage, thermal energy storage, cold energy storage and hydrogen energy storage. The general model is as follows: 1) Charging and discharging power and state constraints: Where: x is the type of energy storage device, e, h, c and H2 represent electric, heat, cold and hydrogen energy storage respectively; P x,cha,t , P x,dis,t They represent the charging and discharging power of energy storage device x at time t; I x,cha,t ,I x,dis,t They represent the charging and discharging states of the energy storage device x at time t respectively; and Respectively represent the upper and lower limits of the charging power of the energy storage device x; and They represent the upper and lower limits of the energy storage device x’s discharge power respectively; 2) Energy storage state continuity constraint: Where: S x,t is the storage capacity of energy storage device x at time t; δ x is the self-loss coefficient of energy storage device x; η x,cha , η x,dis are the charging and discharging efficiencies of energy storage device x respectively; is the upper and lower limits of energy storage capacity; S x,1 is the storage capacity of energy storage device x at time 1; S x,24 is the storage capacity of energy storage device x at 24 hours.

7. The cooling, heating and electricity optimization scheduling method of the agricultural park integrated energy system based on biomass-solar energy coupling according to claim 1 is characterized by: In step 2, the flexible load model of the agricultural park is constructed, which specifically includes: (1) Construct a flexible load model for agricultural parks; 1) The greenhouse electrical load includes electric irrigation machines, ventilators, roller shutter machines, plant lighting and crop dryers. The greenhouse electrical load model is as follows: Where: P gh,e,t is the power consumption of the greenhouse at time t; P pump,t , P fan,t , P driver,t , P light,t and P ldryer,t are the rated power of a single electric irrigation machine, ventilator, roller shutter machine, plant supplementary light and crop dryer respectively; d pump,t ,d fan,t ,d driver,t ,d light,t and d dryer,t is a 0-1 variable, corresponding to the working status of the electric irrigation machine, ventilator, roller shutter, plant light and crop dryer; N1 is the number of electric irrigation machines; N2 is the number of ventilators; N3 is the number of roller shutters; N4 is the number of plant light; N5 is the number of crop dryers; 2) The heat load model of the greenhouse is as follows: Where: T gh,t is the greenhouse temperature at time t; T gh,t+1 is the greenhouse temperature at time t+1; P gh,su,t , P gh,in,t and P gh,loss,t are the heat supply, heat production and heat dissipation of the greenhouse at time t; ρ air 、c air and ν gh are respectively the air density, specific heat capacity and volume of the greenhouse; the heat loss of the greenhouse P gh,loss,t Includes heat losses from walls, floors and air flow; 3) The power load of the breeding farm includes ventilation system, feed feeding system and waste treatment system. The heating model of the breeding farm is as follows: Where: P farm,e,t is the power consumption of the breeding farm at time t; P t air , P t feed and P t waste are the power consumption of ventilation system, feed feeding system and waste treatment system at time t respectively; and are 0-1 variables, indicating whether the ventilation system, feed feeding system and waste treatment system are in working state at time t; M1 is the number of ventilation systems; M2 is the number of feed feeding systems; M3 is the number of waste treatment systems; Among them, the feed feeding system integrates feed crusher, feed mixer and automatic feeder. The electrical load model of the feed feeding system is as follows: Where: P t feed is the output of the feeding system at time t; and They are the rated power of feed crusher, feed mixer and automatic feeder respectively; α cut , α mix and α rel It is a 0-1 variable, indicating the working status of each device; and The working efficiency of each equipment in the feed feeding system; The waste treatment system includes sewage treatment equipment and garbage crushing equipment. The electrical load model of the waste treatment system is as follows: Where: P t sewag and eP t duc are the power of treating sewage and park garbage at time t respectively; The power consumption of the waste treatment system; (2) Conduct flexible load characteristics analysis in agricultural parks; 1) Translable load The shiftable load has continuous power consumption time, and the shiftable load model is as follows: Where: and L shift are the loads before and after translation respectively; S shift is the set of starting periods; They are respectively S ,t S+1 ,t D The load of the moment; They are respectively after translation at τ, τ+1, τ+t D -1 time load; [t sh- ,t sh+ ] is the shiftable interval; t s is the starting period; t D is the duration; The cost of the park to be compensated after the translation F shift for: Where: Price compensation for unit load shifting; For L shift The sum of translation loads; t sh- is the starting time of load translation; t sh+ -t D +1 is the starting time after the load translation; 2) The transferable load model is as follows: Where: are the upper and lower limits of the transferable load respectively; β t is a 0-1 variable, indicating whether to transfer at time t; P t tran* , P t tran are the loads at time t before and after the transfer; [t tr- ,t tr+ ] is the transfer interval; The cost of the park to be compensated after the transfer F tran for: Where: compensation price for load shifting; 3) The load reduction model is as follows: Where: P t cut* , P t cut are the loads before and after the reduction at time t; γ t is a 0-1 variable, indicating whether it is cut at time t; is the maximum continuous reduction time; N max is the maximum number of reductions; Costs to be compensated to the park after reduction F cut for: Where: The compensation price for load reduction.

8. The cooling, heating and electricity optimization scheduling method of the agricultural park integrated energy system based on biomass-solar energy coupling according to claim 1 is characterized by: In step 3, a cooling, heating and electricity optimization scheduling model for the agricultural park integrated energy system based on biomass-solar energy coupling is established, which specifically includes: Step 3.1: Construct the objective function Energy purchase cost C based on agricultural park integrated energy system AIES buy , wind and solar cost C cut 、Carbon trading costs C CO2 , Operation and maintenance cost C om and the park compensation cost C fill , construct with a total cost C total The minimum low-carbon economy targets are as follows: C total =min(C buy +C cut +C CO2 +C om +C fill ) (27); 1) Energy purchase cost Where: α e and α g are the unit prices of electricity and gas respectively; P e,buy,t , P g,buy,t They are the power of electricity and gas purchased at time t respectively; T is the time period; 2) Cost of curtailing wind and solar power Where: wt ,δ pv are the penalty factors for wind and solar abandonment, respectively; P wt,cut,t , P pv,cut,t They are wind power abandonment and solar power abandonment at time t respectively; 3) Carbon trading costs Construct a ladder-type carbon trading mechanism model, the model is as follows: Where: E IES 、E e,buy 、E BSC and E GB They are the total quota of AIES, external power purchase quota, BSC system quota and GB quota; e , χ g and χ b are the carbon emission quota coefficients per unit of electricity, natural gas and biomass gas consumption; E IES,a 、E e,buy,a , P BSC,b,a and P GB,h,a are the actual carbon emissions of IES, power purchase from higher authorities, BSC system and GB; E MR,a is the amount of CO2 actually absorbed by MR; E IES,t is the carbon emission trading amount; H is the coefficient corresponding to different carbon emission ranges; 4) Operation and maintenance costs Where: β j is the unit operation and maintenance cost of the jth type of equipment; P j,t is the output power of the jth device at time t; j is the type of device; 5) Park compensation costs C fill =F shift +F tran +F cut (32); Step 3.2: Constraints The constraints include wind and solar power output constraints, energy purchase constraints, power balance constraints, equipment energy constraints and energy storage constraints; the details are as follows: 1) Wind and solar power output constraints Where: and They are the upper limits of the output of photovoltaic units and wind turbine units respectively; P pv,t is the photovoltaic power at time t; P wt,t is the fan power at time t; 2) Restrictions on purchasing electricity and gas Where: and They are the upper and lower limits of purchased power respectively; and are the upper and lower limits of gas purchase power respectively; P e,buy,t P is the power purchased from the upper grid at time t; g,buy,t The gas power purchased from the superior gas network at time t; 3) Electric power balance constraints Where: and They are respectively the electric loads that can be translated, transferred and reduced at time t; 4) Thermal power balance constraints Where: P farm,h,t is the heating power of the breeding plant at time t; and They are the heat load that can be translated and reduced at time t respectively; 5) Cold power balance constraint P BSC,c,t +P ERU,c,t +P c,dis,t =P load,c,t +P c,cha,t (37); 6) Natural gas power balance constraints P g,buy,t +P MR,g,t =P GB,g,t (38); 7) Hydrogen power balance constraints

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