Configuration and operation optimization method for park comprehensive energy system containing fused salt heat storage

Abstract

The invention relates to a configuration and operation optimization method for a park comprehensive energy system containing fused salt heat storage, and the method comprises the steps: constructing a unit equipment physical model which comprises energy equipment in the park comprehensive energy system and a fused salt heat storage system; according to the unit equipment physical model, a comprehensive energy system operation optimization mathematical model including a target function and constraint conditions is constructed based on a mathematical programming method; the comprehensive energy system operation optimization mathematical model is solved, and the optimized comprehensive energy system capacity configuration and the heat charging / discharging strategy of the fused salt heat storage system are obtained. Compared with the prior art, by integrating multiple energy forms such as electricity, gas and cold and utilizing the efficient heat storage and release capacity of the fused salt heat storage technology, the flexibility and the renewable energy consumption level of the system are remarkably improved, and the comprehensive energy system is promoted to develop towards the low-carbon and intelligent direction.

Description

Technical Field

[0001] This invention relates to the field of energy storage and integrated energy system application technology, and in particular to a method for configuring and optimizing the operation of an integrated energy system for a park containing molten salt thermal storage. Background Technology

[0002] In recent years, the scale of renewable energy sources, represented by wind and solar power, has expanded rapidly in the power system. At the same time, the intermittency and volatility of renewable energy sources lead to challenges for the power system, such as fluctuating power supply times and times and increased peak-shaving pressure. Compared with electrochemical and mechanical energy storage technologies, thermal energy storage technology offers longer lifespan, lower cost, and is safer and more stable than electrical storage. Against this backdrop, molten salt thermal energy storage technology, with its high energy density, long lifespan, and wide temperature range, has become a key technology for solving the problems of renewable energy integration and multi-energy synergistic optimization.

[0003] When the proportion of renewable energy sources such as wind and solar power in the power supply exceeds 30%, integrated energy systems must be equipped with at least 15% energy storage capacity to ensure the stability of the power grid. Molten salt thermal energy storage technology can achieve energy supply across time scales through thermal energy storage and release. Integrated energy systems have the potential for multi-energy coupling and system integration optimization, and can significantly improve energy utilization efficiency through the synergy of electricity, heat, and cooling multi-energy flows. In user-side integrated energy systems, molten salt thermal energy storage can be coordinated with distributed energy sources such as solar and wind power, reducing energy costs and carbon emissions through strategies such as "valley electricity thermal storage and peak-hour heat release" or "waste heat recovery." At the same time, based on mathematical optimization methods for coordinated system scheduling, the complementary potential between molten salt thermal energy storage and electricity / heat / cooling subsystems can be further explored, thereby improving overall energy efficiency and economy. In the future, with the decrease in the cost of molten salt materials and the maturity of system integration technology, molten salt thermal energy storage is expected to play a more critical role in scenarios such as industrial parks and regional energy stations, promoting the development of integrated energy systems towards low-carbon and intelligent directions.

[0004] Existing integrated energy systems rarely consider incorporating molten salt thermal energy storage systems. Chinese patent application CN117709653A mentions a capacity optimization method for building integrated energy systems that considers the flexibility of molten salt thermal energy storage. This patent provides a new feasible method for optimizing the configuration of equipment in building integrated energy systems by combining molten salt thermal energy storage with photovoltaic power generation, thereby achieving thermal-electric decoupling of the energy hub during the energy dispatch phase. Although this patent utilizes the optimization method of incorporating molten salt thermal energy storage systems, it mainly targets the optimization of building integrated energy systems. The integrated energy system of a park is different from that of a building integrated energy system. It not only includes photovoltaic power generation but also other different renewable energy power generation methods. The equipment and operational influencing factors involved are also different, resulting in complex coupling relationships.

[0005] In summary, in order to promote the optimization and improvement of the overall energy efficiency of integrated energy systems, there is a need for a method to optimize the capacity configuration and operation scheduling of integrated energy systems in industrial parks from the perspective of considering the optimal investment and operating costs. Summary of the Invention

[0006] The purpose of this invention is to overcome the shortcomings of the existing technology and provide a method for configuring and optimizing the operation of a comprehensive energy system for a park with molten salt thermal storage.

[0007] The objective of this invention can be achieved through the following technical solutions:

[0008] A method for configuring and optimizing the operation of an integrated energy system for a park containing molten salt thermal storage, the method comprising:

[0009] Construct physical models of unit equipment, including energy equipment and molten salt thermal storage systems in the park's integrated energy system;

[0010] Based on the physical model of the unit equipment, a comprehensive energy system operation optimization mathematical model including objective function and constraints is constructed using mathematical programming methods;

[0011] Solve the mathematical model for optimizing the operation of the integrated energy system to obtain the optimized capacity configuration of the integrated energy system and the charging / discharging strategy of the molten salt thermal storage system;

[0012] The molten salt thermal storage system is modeled based on the current capacity of the molten salt thermal storage system, the current stored or released heat, the upper and lower limits of thermal storage power, the upper and lower limits of heat release power, the hourly heat loss rate, and the rated capacity.

[0013] Furthermore, the energy equipment in the integrated energy system of the park includes wind turbines, photovoltaic power generation units, electric heaters, steam generators, electric chillers, high-temperature heat pumps, and storage batteries.

[0014] Furthermore, the model of the wind turbine is as follows:

[0015]

[0016] in, P is the predicted wind turbine output at time t. WT V is the rated power of the fan. t Let V be the actual wind speed at time t. ci V is the cut-in wind speed for the fan. r V is the rated wind speed of the fan. co Cut off the wind speed for the fan;

[0017]

[0018] Where V0 represents the known wind speed at a height h0 above the ground, n is the surface friction coefficient, and h t Let be the height above the ground at time t;

[0019] The model of the photovoltaic power generation unit is as follows:

[0020]

[0021] in, Let A be the photovoltaic power output at time t, Ra represent the current irradiance of the region, and A be the irradiance of the region. PV Indicates the area covered by photovoltaic panels, η PV η represents the photovoltaic power conversion efficiency. in For inverter efficiency;

[0022] The model of the electric heater is as follows:

[0023]

[0024] in, Let be the heat output power of the electric heater at time t. Let η be the power consumption of the electric heater at time t. EB S represents the heating efficiency of the electric heater. EB This refers to the rated capacity power of the electric heater;

[0025] The model of the steam generator is as follows:

[0026]

[0027] in, Let be the steam generator's steam production power at time t. η is the heat input to the steam generator at time t. S S represents the efficiency of a steam generator in converting thermal energy into steam. S This refers to the rated capacity power of the steam generator;

[0028] The model of the electric chiller is as follows:

[0029]

[0030] in, Let be the cooling power output of the electric chiller at time t. Let COP be the power consumption of the electric chiller at time t. EC S is the coefficient of performance of the electric chiller. EC This refers to the rated capacity power of the electric chiller;

[0031] The model of the high-temperature heat pump is as follows:

[0032]

[0033] in, Let t be the steam production power output of the high-temperature heat pump at time t. Let be the power consumption of the high-temperature heat pump at time t, and COP. HP S is the coefficient of performance of a high-temperature heat pump. HP This refers to the rated capacity power of the high-temperature heat pump;

[0034] The model of the storage battery is as follows:

[0035]

[0036] in, Let be the capacity of the battery at time t. and Both variables are 0-1, representing the charge / discharge state of the battery at time t. Batteries cannot be charged and discharged simultaneously at the same time. and These are the upper and lower limits of the battery's discharge power, respectively. and These represent the upper and lower limits of the battery's storage capacity, S. e This refers to the rated capacity of the battery.

[0037] Furthermore, both the wind turbine generators and photovoltaic power generation units are subject to output constraints, the conditions of which are as follows:

[0038]

[0039] in, The predicted wind turbine output at time t. Let be the photovoltaic power output at time t. and This corresponds to the predicted output value of the new energy generating unit at time t. and This represents the amount of electricity wasted by the corresponding new energy generating unit at time t.

[0040] Furthermore, the model of the molten salt thermal storage system is as follows:

[0041]

[0042] in, Let t be the capacity of the molten salt thermal storage system at time t. and These represent the heat stored or released by the system at time t, respectively. and These represent the upper and lower limits of the thermal storage capacity of the molten salt thermal storage system. and γ represents the upper and lower limits of the heat release power of the molten salt thermal storage system, γ is the hourly heat loss rate of the molten salt thermal storage, and S is the upper and lower limits of the heat release power of the molten salt thermal storage system.MS This refers to the rated capacity of the molten salt thermal storage system.

[0043] Furthermore, the objective function of the mathematical model for optimizing the operation of the integrated energy system is:

[0044] minF=C inv +C om +C buy ,

[0045] Among them, C inv C represents the initial investment cost of each device in the system. om For the operation and maintenance costs of each piece of equipment, C buy For time-of-use electricity purchase and sale costs;

[0046]

[0047] Among them, C op,WT C represents the unit capacity investment cost of wind turbine units. op,PV C represents the unit capacity investment cost of photovoltaic units. op,e C represents the unit capacity investment cost of the battery. op,MS C represents the unit capacity investment cost of the molten salt thermal energy storage system. op,EB C represents the unit capacity investment cost of the electric heater. op,S C represents the unit capacity investment cost of the steam generator. op,EC C represents the unit capacity investment cost of the electric chiller. op,HP S represents the unit capacity investment cost of a high-temperature heat pump. WT For the capacity configuration of wind turbine units, S PV For the capacity configuration of photovoltaic units, S e S represents the rated capacity of the battery. MS S represents the rated capacity of the molten salt thermal storage system. EB S represents the rated capacity of the electric heater. S S is the rated capacity power of the steam generator. EC S represents the rated capacity power of the electric chiller. HP This refers to the rated capacity power of the high-temperature heat pump;

[0048]

[0049] Among them, C WT C represents the unit operation and maintenance cost of wind turbine units. PV C represents the unit operation and maintenance cost of photovoltaic units. e For the unit operation and maintenance cost of batteries, C MS C represents the unit operation and maintenance cost of a molten salt thermal energy storage system. EB C represents the unit operation and maintenance cost of the electric heater. S C represents the unit operation and maintenance cost of the steam generator.EC For the unit operation and maintenance cost of electric chillers, C HP For the unit operation and maintenance cost of high-temperature heat pumps, POW WT For the total annual output of wind turbines, POW PV For the total annual output of photovoltaic units, POW e For the total annual output of the battery, POW MS For the total annual output of the molten salt thermal storage system, POW EB For the total annual output of the electric heater, POW S For the total annual output of the steam generator, POW EC For the total annual output of the electric chiller, POW HP The total annual output of the high-temperature heat pump;

[0050]

[0051] in, and For time-of-use electricity purchases, the price of electricity sold... and This refers to the power purchased and sold on an hourly basis.

[0052] Furthermore, the constraints of the integrated energy system operation optimization mathematical model include energy balance constraints and equipment capacity constraints, and the equipment capacity constraints include steam load constraints and cooling load constraints.

[0053] Furthermore, the energy balance constraint is:

[0054]

[0055] in, The predicted wind turbine output at time t. Let be the photovoltaic power output at time t. Let be the battery discharge power at time t. Let t be the power purchased at time t. Let t be the electrical load of the park at time t. Let be the battery charging power at time t. Let be the power consumption of the electric heater at time t. Let t be the power consumption of the high-temperature heat pump. Let be the power consumption of the electric chiller at time t. Let be the electricity sold at time t;

[0056] The steam load constraint is:

[0057]

[0058] in, Let t be the regional steam load demand. Let t be the steam production power output of the high-temperature heat pump at time t. Let t be the steam generation power of the steam generator at time t;

[0059] The cooling load constraint is:

[0060]

[0061] in, Let be the cooling power of the electric chiller at time t. Let t be the regional cooling load demand at time t.

[0062] Furthermore, based on preset parameters and actual application scenarios, the mathematical model for optimizing the operation of the integrated energy system is solved. A time-dimensional operation optimization strategy is adopted. Starting from the time dimension, the division of time is considered through time-of-use pricing. Combined with the analysis of renewable energy output and load demand in the integrated energy system, the charging / discharging strategy of the molten salt thermal storage system is optimized.

[0063] Furthermore, after solving the mathematical model for optimizing the operation of the integrated energy system, historical cases were selected to verify the effectiveness of the optimized integrated energy system capacity configuration and the charging / discharging strategy of the molten salt thermal storage system through quantitative analysis.

[0064] Compared with the prior art, the beneficial effects of the present invention include:

[0065] 1. In this invention, molten salt thermal energy storage originates from off-peak electricity heating and renewable energy sources. It converts excess electricity at night into thermal energy storage, reducing the power supply pressure on the grid during peak hours. At the same time, it enhances the renewable energy absorption capacity, helping to achieve the grid balance goal of "peak shaving and valley filling," and reducing dependence on fossil fuels and carbon emissions. This invention considers a comprehensive energy system with molten salt thermal energy storage. By integrating multiple energy forms such as electricity, gas, and cooling, and utilizing the efficient heat storage and release capacity of molten salt thermal energy storage technology, it significantly improves the system's flexibility and renewable energy absorption level, promoting the development of comprehensive energy systems towards low-carbon and intelligent directions. This invention incorporates the molten salt thermal energy storage system into the comprehensive energy system. Due to its large capacity, it is more suitable for the long-term storage of high-grade thermal energy, which can significantly reduce energy waste and improve the stability and economy of the comprehensive energy system.

[0066] 2. This invention aims to minimize the total sum of equipment investment and operating costs. By dynamically adjusting the equipment scale through mathematical programming, it achieves synergistic optimization of investment and operating costs. Combined with the peak-valley difference in electricity prices, it stores electricity / heat during low-price periods and releases or sells electricity during high-price periods, significantly reducing overall costs and improving economic efficiency.

[0067] 3. In this invention, the storage battery and the molten salt thermal storage system correspond to short-term regulation and long-term thermal storage, respectively. The two work together to cope with fluctuations. The storage battery can undertake high-frequency charging and discharging tasks during the transition season to alleviate short-term power supply gaps. The molten salt thermal storage system can stably release heat during the high heating demand period in winter to ensure steam load. The synergistic effect of the two can not only maintain high economic efficiency, but also enhance the stability and reliability of the park's integrated energy system.

[0068] 4. When solving the mathematical model for the operation optimization of the integrated energy system, this invention adopts a time-dimensional operation optimization strategy. Starting from the time dimension, the strategy is optimized, fully considering the characteristics of heat demand changing with the seasons. Seasonal optimization scheduling is carried out, and the steam generator and high-temperature heat pump supply steam on demand. The electric chiller responds flexibly to the cooling load, enabling the park's integrated energy system to dynamically adapt to seasonal load changes. Attached Figure Description

[0069] Figure 1 This is a flowchart of the method of the present invention;

[0070] Figure 2 This is a physical structure diagram of the integrated energy system constructed in an embodiment of the present invention;

[0071] Figure 3 This is a diagram showing the heat charging and discharging schedule of the molten salt thermal storage system on a typical winter day in an embodiment of the present invention.

[0072] Figure 4 This is a diagram showing the heat charging and discharging schedule of the molten salt thermal storage system on a typical transition day in this embodiment of the invention.

[0073] Figure 5 This is a diagram showing the heat charging and discharging schedule of the molten salt thermal storage system on a typical summer day in an embodiment of the present invention. Detailed Implementation

[0074] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of the present invention.

[0075] Example 1

[0076] This embodiment discloses a method for configuring and optimizing the operation of a comprehensive energy system for a park containing molten salt thermal storage. This method optimizes the capacity configuration of each device in the comprehensive energy system, achieves the optimal heat charging and discharging strategy for the thermal storage system, and improves the overall energy efficiency of the system. The specific process of the method is as follows: Figure 1 As shown, it includes:

[0077] Step S1: Construct a physical model of the unit equipment, including the energy equipment and molten salt thermal storage system in the park's integrated energy system;

[0078] Step S2: Based on the physical model of the unit equipment, construct a comprehensive energy system operation optimization mathematical model including objective function and constraints using mathematical programming methods;

[0079] Step S3: Solve the mathematical model for optimizing the operation of the integrated energy system to obtain the optimized capacity configuration of the integrated energy system and the charging / discharging strategy of the molten salt thermal storage system;

[0080] Step S4: Select historical cases and verify the effectiveness of the optimized integrated energy system capacity configuration and the charging / discharging strategy of the molten salt thermal storage system through quantitative analysis.

[0081] In step S1, the energy equipment in the park's integrated energy system includes wind turbines, photovoltaic power generation units, electric heaters, steam generators, electric chillers, high-temperature heat pumps, and storage batteries.

[0082] The model of the wind turbine is as follows:

[0083]

[0084] in, P is the predicted wind turbine output at time t. WT V is the rated power of the fan. t Let V be the actual wind speed at time t. ci V is the cut-in wind speed for the fan. r V is the rated wind speed of the fan. co Cut off the wind speed for the fan;

[0085]

[0086] Where V0 represents the known wind speed at a height h0 above the ground, n is the surface friction coefficient, and h t Let t be the height above the ground at time t.

[0087] The model for a photovoltaic power generation unit is as follows:

[0088]

[0089] in, The photovoltaic output power is represented by Ra, which represents the current irradiance of the region, and A. PV Indicates the area covered by photovoltaic panels, η PV η represents the photovoltaic power conversion efficiency. in This refers to the inverter efficiency.

[0090] Both wind turbine generators and photovoltaic power generation units are subject to output constraints, the conditions of which are as follows:

[0091]

[0092] in, The predicted wind turbine output at time t. For photovoltaic power output, and To correspond to the predicted output values ​​of new energy generating units, and This is to address the abandoned electricity generated by new energy power plants.

[0093] The model of the electric heater is as follows:

[0094]

[0095] in, For the heat output power of the electric heater, η represents the power consumption of the electric heater. EB S represents the heating efficiency of the electric heater. EB This refers to the rated capacity power of the electric heater.

[0096] The model of the steam generator is as follows:

[0097]

[0098] in, The steam generation capacity of the steam generator. The heat input to the steam generator, η S S represents the efficiency of a steam generator in converting thermal energy into steam. S This refers to the rated capacity power of the steam generator.

[0099] The model of the electric chiller is as follows:

[0100]

[0101] in, The cooling power output of the electric chiller. The power consumption of the electric chiller, COP EC S is the coefficient of performance of the electric chiller. EC This refers to the rated capacity power of the electric chiller.

[0102] The model of a high-temperature heat pump is as follows:

[0103]

[0104] in, This refers to the steam production power output of the high-temperature heat pump. For the power consumption of a high-temperature heat pump, COP HP S is the coefficient of performance of a high-temperature heat pump. HPThis refers to the rated capacity power of the high-temperature heat pump.

[0105] The battery model is as follows:

[0106]

[0107] in, Let be the capacity of the battery at time t. and Both variables are 0-1, representing the charge / discharge state of the battery at time t. Batteries cannot be charged and discharged simultaneously at the same time. and These are the upper and lower limits of the battery's discharge power, respectively. and These represent the upper and lower limits of the battery's storage capacity, S. e This refers to the rated capacity of the battery.

[0108] In step S1, the model of the molten salt thermal storage system is as follows:

[0109]

[0110] in, Let t be the capacity of the molten salt thermal storage system at time t. and These represent the heat stored or released by the system at time t, respectively. and These represent the upper and lower limits of the thermal storage capacity of the molten salt thermal storage system. and γ represents the upper and lower limits of the heat release power of the molten salt thermal storage system, γ is the hourly heat loss rate of the molten salt thermal storage, and S is the upper and lower limits of the heat release power of the molten salt thermal storage system. MS This refers to the rated capacity of the molten salt thermal storage system.

[0111] In step S2, the objective function of the integrated energy system operation optimization mathematical model is:

[0112] minF=C inv +C om +C buy ,

[0113] Among them, C inv C represents the initial investment cost of each device in the system. om For the operation and maintenance costs of each piece of equipment, C buy For time-of-use electricity purchase and sale costs;

[0114]

[0115] Among them, C op,WT C represents the unit capacity investment cost of wind turbine units. op,PV C represents the unit capacity investment cost of photovoltaic units. op,eC represents the unit capacity investment cost of the battery. op,MS C represents the unit capacity investment cost of the molten salt thermal energy storage system. op,EB C represents the unit capacity investment cost of the electric heater. op,S C represents the unit capacity investment cost of the steam generator. op,EC C represents the unit capacity investment cost of the electric chiller. op,HP S represents the unit capacity investment cost of a high-temperature heat pump. WT For the capacity configuration of wind turbine units, S PV For the capacity configuration of photovoltaic units, S e S represents the rated capacity of the battery. MS S represents the rated capacity of the molten salt thermal storage system. EB S represents the rated capacity of the electric heater. S S is the rated capacity power of the steam generator. EC S represents the rated capacity power of the electric chiller. HP This refers to the rated capacity power of the high-temperature heat pump;

[0116]

[0117] Among them, C WT C represents the unit operation and maintenance cost of wind turbine units. PV C represents the unit operation and maintenance cost of photovoltaic units. e For the unit operation and maintenance cost of batteries, C MS C represents the unit operation and maintenance cost of a molten salt thermal energy storage system. EB C represents the unit operation and maintenance cost of the electric heater. S C represents the unit operation and maintenance cost of the steam generator. EC For the unit operation and maintenance cost of electric chillers, C HP For the unit operation and maintenance cost of high-temperature heat pumps, POW WT For the total annual output of wind turbines, POW PV For the total annual output of photovoltaic units, POW e For the total annual output of the battery, POW MS For the total annual output of the molten salt thermal storage system, POW EB For the total annual output of the electric heater, POW S For the total annual output of the steam generator, POW EC For the total annual output of the electric chiller, POW HP The total annual output of the high-temperature heat pump;

[0118]

[0119] in, and For time-of-use electricity purchases, the price of electricity sold... and This refers to the power purchased and sold on an hourly basis.

[0120] In step S2, the constraints of the integrated energy system operation optimization mathematical model include energy balance constraints and equipment capacity constraints. The equipment capacity constraints include steam load constraints and cooling load constraints.

[0121] The energy balance constraint is:

[0122]

[0123] in, The predicted wind turbine output at time t. Let be the photovoltaic power output at time t. This refers to the battery discharge power. For the power purchase capacity, For the park's electrical load, To charge the battery, The power consumption of the electric heater, For high-temperature heat pump power consumption, The power consumption of the electric chiller This refers to the electricity sold.

[0124] Steam load constraints are:

[0125]

[0126] in, To meet the regional steam load demand, This refers to the steam production power output of the high-temperature heat pump. This refers to the steam generation capacity of the steam generator.

[0127] The cooling load constraint is:

[0128]

[0129] in, This refers to the cooling capacity of the electric chiller. To meet the regional cooling load demand.

[0130] In step S3, the mathematical model for optimizing the operation of the integrated energy system is solved based on preset parameters and actual application scenarios. A time-dimensional operation optimization strategy is adopted. Starting from the time dimension, the division of time is considered through time-of-use pricing. Combined with the analysis of renewable energy output and load demand in the integrated energy system, the charging / discharging strategy of the molten salt thermal storage system is optimized.

[0131] The solution to the above-mentioned optimization method for the configuration and operation of the integrated energy system in the park containing molten salt thermal storage is based on the open-source PUP library in Python. After constructing the objective function and constraints using the open-source PUP library in Python, the known values ​​are input into the objective function and constraints. Finally, running the program can obtain the capacity configuration of the integrated energy system and the charging / discharging strategy of the molten salt thermal storage system. The capacity configuration values ​​of the integrated energy system include: wind turbine output power, photovoltaic unit output power, battery capacity, molten salt thermal storage system capacity, electric chiller capacity, steam generator capacity, high-temperature heat pump capacity, and electric heater capacity. The charging / discharging strategy of the molten salt thermal storage system is the hourly charging / discharging / storing of the molten salt thermal storage system throughout the day. The known values ​​are the remaining values ​​in the objective function and constraints after removing the values ​​of the integrated energy system capacity configuration and the charging / discharging strategy of the molten salt thermal storage system.

[0132] In step S4, historical cases are selected to verify the effectiveness of the optimized integrated energy system capacity configuration and the charging / discharging strategy of the molten salt thermal storage system through quantitative analysis. The open-source Pulp library in Python is also used here. The solution process using the open-source Pulp library in Python is existing technology and will not be elaborated upon here.

[0133] Figure 2 This diagram shows the physical structure of an integrated energy system that incorporates molten salt thermal energy storage. The left side of the diagram represents the wind farm, photovoltaic system, and power grid, which form the energy source of the system. The wind farm and photovoltaic system generate electricity using wind and solar power, respectively, while the power grid transmits power from an external grid. Figure 2 The right side represents the power load end of the integrated energy system, i.e., the output end, which includes electrical load, steam load, and cooling load. The electrical load directly obtains electricity from wind farms, photovoltaic systems, and the power grid. The steam load obtains heat energy in two ways: firstly, by using electricity from wind farms, photovoltaic systems, and the power grid to drive a high-temperature heat pump; secondly, by using an electric heater to heat a molten salt storage tank, which then heats the steam generator, indirectly obtaining heat energy. The cooling load obtains electricity from wind farms, photovoltaic systems, and the power grid to drive an electric chiller for electric cooling. In the diagram, batteries can store excess electricity from wind farms, photovoltaic systems, and the power grid, supporting the electricity demand of each load for short periods during peak electricity consumption periods. The molten salt storage tank can also store excess electricity from wind farms, photovoltaic systems, and the power grid as heat energy, providing heating during the peak heat demand period in winter.

[0134] To verify the effectiveness of the aforementioned method, a specific industrial park was selected for analysis. The basic load of the chosen case park includes three forms: cooling, electricity, and steam load. Molten salt thermal storage and batteries are the energy storage devices in the park.

[0135] To determine the capacity configuration and operation scheduling of the system in this case study park, it is necessary to obtain relevant equipment parameters. The specific parameters obtained after actual measurement are shown in Tables 1 and 2 below.

[0136] Table 1 Equipment Parameter Table

[0137]

[0138] Table 2 Battery Equipment Parameters

[0139] parameter unit numerical values Charging load rate ％ 0-100 Energy storage self-loss rate ％ / h neglect Charging efficiency ％ 90 Discharge efficiency ％ 90 Lower limit of energy storage capacity operation ％ 10 upper limit of energy storage capacity ％ 90 Investment costs Yuan / kWh 1800 Operation and maintenance costs Yuan / kWh 0.018

[0140] In this embodiment, the overall strategy for system scheduling optimization is to use renewable energy and energy storage devices to meet the park's load demand during peak hours and to charge the energy storage devices during off-peak hours. This can reduce the system's operating costs and alleviate grid pressure.

[0141] Table 3 below shows the capacity configuration results for this park after being solved using the method in this embodiment. It can be seen that no photovoltaic (PV) units are configured. The reason for this is that, after investigation, it was found that the local solar irradiance is too low. Forcibly laying large areas of PV panels would lead to higher costs and have a minimal impact on the system. Therefore, it can be seen that optimizing the equipment combination according to the actual situation can reduce the overall cost.

[0142] Table 3 Capacity Configuration Results

[0143]

[0144] Industrial parks have varying demands for different energy sources at different times. This paper selects three typical days from winter, the transitional season, and summer to observe the operation and scheduling strategy of an integrated energy system including battery energy storage and molten salt thermal energy storage. It analyzes the energy interaction at different times and the charging / discharging strategy of the molten salt thermal energy storage system after applying this method. Table 4-6 shows the power supply and demand balance for the three typical days. The table divides a day into 24 hours, showing the power generation, power purchase, power sales, power storage, and power consumption. Power generation is represented by wind power columns and battery discharge columns; power purchase columns represent purchased power; power sales columns represent sold power; battery charging columns represent stored power; and the remaining columns represent power consumption.

[0145] Table 4. Electricity Supply and Demand Balance Sheet for Typical Winter Days

[0146]

[0147] As can be seen from Table 4 above, which shows the power supply and demand balance of a typical winter day, wind power has a large output, but is limited by the characteristics of winter winds. Wind power output drops sharply from evening to night, failing to meet load demand. This leads to a significant increase in electricity purchases during the afternoon (15:00-17:00) and night (21:00-23:00) to make up for the power shortage. The power of electric chillers is almost zero, which is consistent with the low cooling demand in winter. During the morning peak electricity period from 8:00 to 12:00, it was found that the output of wind turbines was sufficient to meet the power demand of the park, and there was even surplus electricity sold to reduce daily operating costs.

[0148] As can be seen from Table 5, the power supply and demand balance sheet for a typical day during the transition season, wind power output is more dispersed between 2:00 and 7:00, resulting in more drastic fluctuations in overall output. This leads to higher daily power purchases, significantly higher than typical winter days. However, during the off-peak period of 4:00-7:00, a significant amount of electricity is stored in batteries, and during the peak period of 10:00-14:00, batteries release some electricity, increasing battery charging and discharging activity. The energy storage system undertakes more peak-shaving tasks, alleviating the pressure on power supply demand. During the transition season, electric chillers begin to operate in small quantities, consuming a small amount of electricity to meet the cooling load demand of the park.

[0149] Table 5. Typical Daily Electricity Supply and Demand Balance Sheet During the Transition Season

[0150]

[0151] As can be seen from Table 6 below, the power supply and demand balance sheet for typical summer days shows that wind power output is generally stable in summer, providing stable power transmission to the park. Therefore, on typical days during this season, there is only a small demand for electricity purchases between 6:00-7:00 and 16:00-17:00, and there is revenue from electricity sales during peak electricity price periods, reducing operating costs. During this season, the demand for steam load decreases significantly, and the output of electric heating equipment and high-temperature heat pumps also decreases. The power of refrigeration units increases significantly with the increase in cooling load demand during this season.

[0152] Table 6. Electricity Supply and Demand Balance Sheet for Typical Summer Days

[0153]

[0154] In summary, it can be seen that wind power output is distributed differently in different seasons. It is limited in winter, dispersed in the transition season, and relatively stable in summer. Electricity purchase varies with seasonal load. Electricity purchase is large during the peak heating season in winter and the peak cooling season in summer, and decreases during the transition season, which reflects the characteristic of the integrated energy system to dynamically adjust with load demand.

[0155] Figure 3-5 The diagram shows the heat charge and discharge schedule for a molten salt thermal storage system on three typical days. Figure 3In the typical winter day's molten salt thermal storage system charging and discharging scheduling diagram, molten salt charging exhibits higher power during several periods, such as 0:00-7:00 and 15:00-17:00, indicating that this integrated energy system actively charges during winter by utilizing off-peak electricity or surplus wind power. Molten salt discharging is concentrated between 8:00 and 14:00, which coincides with the aforementioned peak daytime heating demand in winter. The molten salt system's heat storage capacity first rises rapidly, then drops significantly due to heat dissipation, and then adjusts with charging, reflecting the frequent response of the thermal storage system to heating demand in winter, with large fluctuations in heat storage capacity.

[0156] exist Figure 4 The molten salt thermal storage system's charging and releasing schedule on a typical day during the transition season shows that the charging power and duration of molten salt are reduced compared to winter, but the charging period is consistent with winter, reflecting the reduced heat demand during the transition season. The molten salt releasing period is still from 8:00 to 14:00, but the intensity is weakened. The rise and fall of the heat storage curve are slowing down, indicating that this integrated energy system reduces the scale of charging and releasing heat according to the heat load characteristics of the transition season, and the change in heat storage is more gradual, reflecting the flexibility and adaptability of energy dispatch.

[0157] exist Figure 5 The heat release and charging schedule of the molten salt thermal storage system on a typical summer day is shown in the diagram. Molten salt charging occurs at a lower power during off-peak hours, and with a significant reduction in summer heating demand, the frequency and intensity of molten salt heat release further decrease. The heat storage curve shows minimal fluctuations and tends to stabilize overall, indicating that the thermal storage system mainly plays an auxiliary regulatory role in summer, with significantly reduced charging and releasing activities to match the characteristics of low summer heating demand.

[0158] In winter, the focus is on the "charge-release" cycle of thermal storage to ensure heating supply; during the transition season, the frequency and intensity of charging and releasing are reduced; and in summer, the system's basic regulation is maintained by minimizing the amount of heat charged and released. Seasonal comparisons clearly demonstrate how this method allows the thermal storage system to coordinate with changes in heat load to achieve efficient energy storage and release, proving the effectiveness of the method. This method helps improve the overall economy and reliability of the system.

[0159] The above examples lead to the following conclusions: In integrated energy systems considering molten salt thermal storage, while the use of lithium-ion batteries has a relatively small impact on the system's capacity, it significantly reduces the installed capacity of the wind power generation system, lowers the overall system installation cost, and allows for a more rational allocation and use of electricity generated from renewable energy. Based on the determined capacity configuration, adjusting the scheduling strategy of the molten salt thermal storage system by dividing the year into winter, transitional season, and summer for system operation scheduling optimization, and employing different operating strategies to meet the electricity, steam, and cooling load demands of typical days in different seasons, can optimize the overall economic benefits of the system and complete the operational optimization of the integrated energy system considering molten salt thermal storage.

[0160] Example 2

[0161] Based on Embodiment 1, this embodiment provides an electronic device, including: one or more processors and a memory, wherein the memory stores one or more programs, and the one or more programs include instructions for executing the aforementioned method for configuring and optimizing the operation of a park integrated energy system containing molten salt thermal storage.

[0162] At the hardware level, the electronic device includes a processor, internal bus, network interface, memory, and non-volatile memory, and may also include other hardware required for business operations. The processor reads the corresponding computer program from the non-volatile memory into memory and then runs it to implement the above-mentioned method for configuring and optimizing the operation of the integrated energy system in the park containing molten salt thermal storage. Of course, in addition to the software implementation, this invention does not exclude other implementation methods, such as logic devices or a combination of hardware and software, etc. That is to say, the execution subject of the following processing flow is not limited to individual logic units, but can also be hardware or logic devices.

[0163] Memory may include non-persistent storage in computer-readable media, such as random access memory (RAM) and / or non-volatile memory, such as read-only memory (ROM) or flash RAM. Memory is an example of computer-readable media.

[0164] Computer-readable media includes both permanent and non-permanent, removable and non-removable media that can store information using any method or technology. Information can be computer-readable instructions, data structures, modules of programs, or other data. Examples of computer storage media include, but are not limited to, phase-change memory (PRAM), static random access memory (SRAM), dynamic random access memory (DRAM), other types of random access memory (RAM), read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), flash memory or other memory technologies, CD-ROM, digital versatile optical disc (DVD) or other optical storage, magnetic tape, disk storage or other magnetic storage devices, or any other non-transferable medium that can be used to store information accessible by a computing device. As defined herein, computer-readable media does not include transient computer-readable media, such as modulated data signals and carrier waves.

[0165] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any person skilled in the art can easily conceive of various equivalent modifications or substitutions within the technical scope disclosed in the present invention, and these modifications or substitutions should all be covered within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A method for configuring and optimizing the operation of a comprehensive energy system for a park containing molten salt thermal storage, characterized in that, The method includes: Construct physical models of unit equipment, including energy equipment and molten salt thermal storage systems in the park's integrated energy system; Based on the physical model of the unit equipment, a comprehensive energy system operation optimization mathematical model including objective function and constraints is constructed using mathematical programming methods; Solve the mathematical model for optimizing the operation of the integrated energy system to obtain the optimized capacity configuration of the integrated energy system and the charging / discharging strategy of the molten salt thermal storage system; The molten salt thermal storage system is modeled based on the current capacity of the molten salt thermal storage system, the current stored or released heat, the upper and lower limits of thermal storage power, the upper and lower limits of heat release power, the hourly heat loss rate, and the rated capacity.

2. The method for configuring and optimizing the operation of a comprehensive energy system for a park containing molten salt thermal storage as described in claim 1, characterized in that, The energy equipment in the park's integrated energy system includes wind turbines, photovoltaic power generation units, electric heaters, steam generators, electric chillers, high-temperature heat pumps, and storage batteries.

3. The method for configuring and optimizing the operation of a comprehensive energy system for a park containing molten salt thermal storage as described in claim 2, characterized in that, The model of the wind turbine is as follows: in, P is the predicted wind turbine output at time t. WT V is the rated power of the fan. t Let V be the actual wind speed at time t. ci V is the cut-in wind speed for the fan. r V is the rated wind speed of the fan. co Cut off the wind speed for the fan; Where V0 represents the known wind speed at a height h0 above the ground, n is the surface friction coefficient, and h t Let be the height above the ground at time t; The model of the photovoltaic power generation unit is as follows: in, Let A be the photovoltaic power output at time t, Ra represent the current irradiance of the region, and A be the irradiance of the region. PV Indicates the area covered by photovoltaic panels, η PV η represents the photovoltaic power conversion efficiency. in For inverter efficiency; The model of the electric heater is as follows: in, Let be the heat output power of the electric heater at time t. Let η be the power consumption of the electric heater at time t. EB S represents the heating efficiency of the electric heater. EB This refers to the rated capacity power of the electric heater; The model of the steam generator is as follows: in, Let be the steam generator's steam production power at time t. η is the heat input to the steam generator at time t. S S represents the efficiency of a steam generator in converting thermal energy into steam. S This refers to the rated capacity power of the steam generator; The model of the electric chiller is as follows: in, Let be the cooling power output of the electric chiller at time t. Let COP be the power consumption of the electric chiller at time t. EC S is the coefficient of performance of the electric chiller. EC This refers to the rated capacity power of the electric chiller; The model of the high-temperature heat pump is as follows: in, Let t be the steam production power output of the high-temperature heat pump at time t. Let be the power consumption of the high-temperature heat pump at time t, and COP. HP S is the coefficient of performance of a high-temperature heat pump. HP This refers to the rated capacity power of the high-temperature heat pump. The model of the storage battery is as follows: in, Let be the capacity of the battery at time t. and Both variables are 0-1, representing the charging / discharging state of the battery at time t. Batteries cannot be charged and discharged simultaneously at the same time. and These are the upper and lower limits of the battery's discharge power, respectively. and These represent the upper and lower limits of the battery's storage capacity, S. e This refers to the rated capacity of the battery.

4. The method for configuring and optimizing the operation of a comprehensive energy system for a park containing molten salt thermal storage as described in claim 2, characterized in that, Both the wind turbine generators and photovoltaic generators are subject to output constraints, the conditions of which are as follows: in, The predicted wind turbine output at time t. Let be the photovoltaic power output at time t. and This corresponds to the predicted output value of the new energy generating unit at time t. and This represents the amount of electricity wasted by the corresponding new energy generating unit at time t.

5. The method for configuring and optimizing the operation of a comprehensive energy system for a park containing molten salt thermal storage as described in claim 1, characterized in that, The model of the molten salt thermal storage system is as follows: in, Let t be the capacity of the molten salt thermal storage system at time t. and These represent the heat stored or released by the system at time t, respectively. and These represent the upper and lower limits of the thermal storage capacity of the molten salt thermal storage system. and γ represents the upper and lower limits of the heat release power of the molten salt thermal storage system, γ is the hourly heat loss rate of the molten salt thermal storage, and S is the upper and lower limits of the heat release power of the molten salt thermal storage system. MS This refers to the rated capacity of the molten salt thermal storage system.

6. The method for configuring and optimizing the operation of a comprehensive energy system for a park containing molten salt thermal storage as described in claim 1, characterized in that, The objective function of the mathematical model for optimizing the operation of the integrated energy system is: minF=C inv +C om +C buy , Among them, C inv C represents the initial investment cost of each device in the system. om For the operation and maintenance costs of each piece of equipment, C buy For time-of-use electricity purchase and sale costs; Among them, C op,WT C represents the unit capacity investment cost of wind turbine units. op,PV C represents the unit capacity investment cost of photovoltaic units. op,e C represents the unit capacity investment cost of the battery. op,MS C represents the unit capacity investment cost of the molten salt thermal energy storage system. op,EB C represents the unit capacity investment cost of the electric heater. op,S C represents the unit capacity investment cost of the steam generator. op,EC C represents the unit capacity investment cost of the electric chiller. op,HP S represents the unit capacity investment cost of a high-temperature heat pump. WT For the capacity configuration of wind turbine units, S PV For the capacity configuration of photovoltaic units, S e S represents the rated capacity of the battery. MS S represents the rated capacity of the molten salt thermal storage system. EB S represents the rated capacity of the electric heater. S S is the rated capacity power of the steam generator. EC S represents the rated capacity power of the electric chiller. HP This refers to the rated capacity power of the high-temperature heat pump. Among them, C WT C represents the unit operation and maintenance cost of wind turbine units. PV C represents the unit operation and maintenance cost of photovoltaic units. e For the unit operation and maintenance cost of batteries, C MS C represents the unit operation and maintenance cost of a molten salt thermal energy storage system. EB C represents the unit operation and maintenance cost of the electric heater. S C represents the unit operation and maintenance cost of the steam generator. EC For the unit operation and maintenance cost of electric chillers, C HP For the unit operation and maintenance cost of high-temperature heat pumps, POW WT For the total annual output of wind turbines, POW PV For the total annual output of photovoltaic units, POW e For the total annual output of the battery, POW MS For the total annual output of the molten salt thermal storage system, POW EB For the total annual output of the electric heater, POW S For the total annual output of the steam generator, POW EC For the total annual output of the electric chiller, POW HP The total annual output of the high-temperature heat pump; in, and For time-of-use electricity purchases, the price of electricity sold... and This refers to the power purchased and sold on an hourly basis.

7. The method for configuring and optimizing the operation of a comprehensive energy system for a park containing molten salt thermal storage as described in claim 1, characterized in that, The constraints of the mathematical model for optimizing the operation of the integrated energy system include energy balance constraints and equipment capacity constraints, and the equipment capacity constraints include steam load constraints and cooling load constraints.

8. The method for configuring and optimizing the operation of a comprehensive energy system for a park containing molten salt thermal storage as described in claim 7, characterized in that, The energy balance constraint is: in, The predicted wind turbine output at time t. Let be the photovoltaic power output at time t. Let be the battery discharge power at time t. Let t be the power purchased at time t. Let t be the electrical load of the park at time t. Let be the battery charging power at time t. Let be the power consumption of the electric heater at time t. Let t be the power consumption of the high-temperature heat pump. Let be the power consumption of the electric chiller at time t. Let be the electricity sold at time t; The steam load constraint is: in, Let t be the regional steam load demand. Let t be the steam production power output of the high-temperature heat pump at time t. Let t be the steam generation power of the steam generator at time t; The cooling load constraint is: in, Let be the cooling power of the electric chiller at time t. Let t be the regional cooling load demand at time t.

9. The method for configuring and optimizing the operation of a comprehensive energy system for a park containing molten salt thermal storage as described in claim 1, characterized in that, The mathematical model for optimizing the operation of the integrated energy system is solved based on preset parameters and actual application scenarios. A time-dimensional operation optimization strategy is adopted. Starting from the time dimension, the division of time is considered through time-of-use pricing. Combined with the analysis of renewable energy output and load demand in the integrated energy system, the charging / discharging strategy of the molten salt thermal storage system is optimized.

10. The method for configuring and optimizing the operation of a comprehensive energy system for a park containing molten salt thermal storage as described in claim 1, characterized in that, After solving the mathematical model for optimizing the operation of the integrated energy system, historical cases were selected to verify the effectiveness of the optimized integrated energy system capacity configuration and the charging / discharging strategy of the molten salt thermal storage system through quantitative analysis.

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