An electric heating system and method of energy utilization thereof

Abstract

The application discloses an electric heating system and an energy utilization method thereof, and the method comprises the following steps: when the overflow electric energy generated by a wind power plant for consumption of power load equipment overflows, the overflow electric energy of the wind power plant is delivered to a heat pump or a hydrogen energy storage system; when the overflow electric energy generated by a fuel cell for consumption of power load equipment overflows, the overflow electric energy generated by the fuel cell is delivered to a power grid; and when high-grade heat energy generated by the fuel cell, the high-grade heat energy is used to heat cold water flowing through the fuel cell to obtain heated hot water, and the hot water is injected into a heat supply pipe network. Therefore, in the electric heating system, the overflow electric energy generated by the wind power plant and the hydrogen energy storage system can be fully utilized, and the high-grade heat energy generated by the fuel cell can be used to heat the hot water in the heat supply pipe network, so that the cascade utilization of energy is realized, the energy utilization efficiency of the electric heating system is improved, and the carbon emission of the electric heating system is reduced.

Description

Technical Field

[0001] This application relates to the field of power system technology, and more specifically, to an electrothermal system and a method for utilizing its energy. Background Technology

[0002] Electric heating systems are a common type of integrated energy system that provides both electrical and thermal energy. The electrical energy generated in an electric heating system supplies power to the electrical load equipment, and the thermal energy generated supplies heat to the electrical load equipment. Because hydrogen is a carbon-free energy source with a high calorific value and can be stored in large quantities, modern electric heating systems use electrolyzers and fuel cells to convert hydrogen into electrical and thermal energy, generating a large amount of electrical energy and high-grade thermal energy.

[0003] However, current electric heating systems neglect waste heat recovery from fuel cells and the utilization of excess electrical energy, resulting in low energy efficiency. Summary of the Invention

[0004] In view of the above problems, this application is made to provide an electrothermal system and its energy utilization method for recovering waste heat generated by fuel cells and distributing and utilizing surplus electrical energy generated by various components, thereby improving the energy utilization rate of the electrothermal system.

[0005] To achieve the above objectives, the following specific solutions are proposed:

[0006] An electrothermal system includes a wind farm, a combined heat and power (CHP) unit, a hydrogen energy storage system, a heat pump, and electrical load equipment. The hydrogen energy storage system includes an electrolyzer, a hydrogen storage tank, and a fuel cell. The hydrogen energy storage system, the CHP unit, and the heat pump are coupled together with electricity, thermal power, and hydrogen.

[0007] The wind farm is used to transfer the overflowing electrical energy generated by the wind farm for the consumption of the electrical load equipment to the heat pump or the hydrogen energy storage system when the overflowing electrical energy is generated by the wind farm.

[0008] The hydrogen energy storage system is used to transmit the overflow electrical energy generated by the fuel cell to the power grid when the electrical energy generated by the fuel cell for the consumption of the electrical load equipment overflows, and to use the high-grade heat energy to heat the cold water flowing through the fuel cell to obtain heated hot water, so as to inject the hot water into the heating network.

[0009] Optionally, the hydrogen energy storage system is also used for:

[0010] Based on the operating characteristics of the electrolyzer, the hydrogen storage tank, and the fuel cell, the system operates under the following constraint formulas:

[0011]

[0012] in, Let be the amount of hydrogen consumed by the electrolyzer in the t-th hour of the day under scenario s. The electrolytic cell has an electrical efficiency. Let Δt be the electrical power of the electrolytic cell in the t-th hour of the day under scenario s, and Δt be the scheduling interval of the electrothermal system. Let X be a binary variable representing the electrolytic cell at hour t in scenario s. ELE The capacity of the electrolytic cell is [missing information]. Let be the electrical power of the fuel cell in the t-th hour of the day under scenario s. Let X be a binary variable representing the fuel cell at hour t in scenario s. FC The capacity of the fuel cell, Let t be the amount of hydrogen stored in the hydrogen storage tank during the t-th hour of the day in scenario s. X represents the amount of hydrogen produced by the fuel cell in the t-th hour of the day under scenario s. HST The capacity of the hydrogen storage tank is [missing information]. This represents the initial state of the hydrogen storage tank on that day. This represents the final state of the hydrogen storage tank on that day. Let κ be the thermal power of the fuel cell in the t-th hour of the day under scenario s. E λ is the first power coefficient of the fuel cell. E κ is the second power coefficient of the fuel cell's electrical power. H Let λ be the first thermal-work coefficient of the fuel cell's thermal power. H The second thermal power coefficient is the thermal power coefficient of the fuel cell.

[0013] Optionally, the electric heating system is used for:

[0014] The hydrogen energy storage system operates according to the aforementioned constraint formulas, with the goal of minimizing the equivalent cost, and operates under the constraints of annual equivalent investment cost, annual operating cost, and annual emission cost.

[0015] The minimum equivalent cost is:

[0016] min C tot =C INV +C O&M +C CO2

[0017] Among them, C INV The annual equivalent investment cost is:

[0018]

[0019] C O&M The annual operating cost is:

[0020]

[0021] C CO2 The annual emission cost is:

[0022]

[0023] Where r is the discount rate of the equipment to be installed in the electric heating system, and L is the lifespan of the equipment to be installed in the electric heating system. X represents the unit investment of the device e to be optimized in the electric heating system. e Let Ψ be the capacity of the device e to be optimized, Ψ be the set of all devices to be optimized in the electrothermal system, Ω be the set of all scenarios, Γ be the set of all time steps, and ω be the set of all time steps. s Let α be the number of days in a year that scene s occurs. CHP β CHP and γ CHP These are the first cost coefficient, the second cost coefficient, and the third cost coefficient of the CHP, respectively. Let CHP be the electrical power of the CHP in the t-th hour of the day under scenario s. Let CHP be the thermal power of the CHP in the t-th hour of the day under scenario s. Let be the thermal power of the fuel cell in the t-th hour of the day under scenario s. Let be the heat power of the heat pump in the t-th hour of the day under scenario s. The unit operation and maintenance cost of the electrolytic cell, The unit operation and maintenance cost of the fuel cell, The unit operation and maintenance cost of the hydrogen storage tank. c represents the unit operation and maintenance cost of the heat pump. CO2 For the carbon unit price, χ E χ represents the carbon emissions of the CHP's motor set. H B represents the carbon emissions of the CHP's thermal power unit. CO2 Free carbon credits.

[0024] Optionally, the electric heating system is also used for:

[0025] The system operates under capacity constraints of a hydrogen energy storage system, which include a first capacity constraint, a second capacity constraint, and a third capacity constraint. The first capacity constraint is that the capacity of the electrolyzer is not greater than the upper limit of the electrolyzer's capacity. The second capacity constraint is that the capacity of the hydrogen storage tank is not greater than the upper limit of the hydrogen storage tank's capacity. The third capacity constraint is that the capacity of the fuel cell is not greater than the upper limit of the fuel cell's capacity.

[0026] Optionally, the electric heating system further includes a heat load device for consuming the heat energy generated by the heat pump, the heat energy generated by the CHP, and the heat energy generated by the hydrogen energy storage system.

[0027] The electric heating system is also used for:

[0028] It operates under both electrical power balance and thermal power balance constraints.

[0029] The power balance constraint is:

[0030]

[0031] in, Let be the electrical power of the wind farm in scenario s within the t-th hour of the day. Let be the load power of the electrical load equipment in the t-th hour of the day under scenario s. Let be the electrical power of the heat pump in the t-th hour of the day under scenario s;

[0032] The thermal power balance constraint is that, in the same scenario and at the same time period, the thermal load power of the thermal load equipment is the sum of the thermal power of the heat pump, the thermal power of the CHP, and the thermal power of the fuel cell.

[0033] Optionally, the electric heating system is also used for:

[0034] It operates under the constraints of CHP's operational characteristics.

[0035] The CHP operating characteristic constraints are as follows:

[0036]

[0037] in, This refers to the first critical electrical power of the CHP in its preset operating mode. This refers to the second critical electrical power of the CHP in the preset operating mode. This refers to the third key electrical power of the CHP in the preset operating mode. This refers to the fourth key electrical power of the CHP in the preset operating mode. This refers to the first critical thermal power of the CHP in the preset operating mode. This refers to the second key thermal power of the CHP in the preset operating mode. This refers to the third key thermal power of the CHP in the preset operating mode. This refers to the fourth key thermal power of the CHP in the preset operating mode. M represents the operating status of CHP in the t-th hour of the day under scenario s. CHP It is a preset constant that is greater than a preset positive value.

[0038] Optionally, the electric heating system is also used for:

[0039] It operates under the constraints of heat pump operating characteristics;

[0040] The operating characteristics of the heat pump are constrained as follows:

[0041]

[0042] in, Let ρ be the electrical power of the heat pump in the t-th hour of the day under scenario s. HP The coefficient of performance (COP) of the heat pump is given. This is the upper limit of the heat power of the heat pump.

[0043] Optionally, the electrical load device is used to consume the electrical energy generated by the wind farm, the electrical energy generated by the hydrogen energy storage system, and the electrical energy generated by the CHP.

[0044] Optionally, the CHP is used to deliver the electrical energy it generates to the electrical load equipment and / or the heat pump.

[0045] An energy utilization method for an electrothermal system, applied to a processor of the electrothermal system as described above;

[0046] The method includes:

[0047] When the electrical energy generated by the wind farm for the consumption of the electrical load equipment overflows, the overflow electrical energy of the wind farm is delivered to the heat pump or the hydrogen energy storage system.

[0048] When the electrical energy generated by the fuel cell for the electrical load equipment overflows, the overflow electrical energy generated by the fuel cell is transmitted to the power grid;

[0049] When the fuel cell generates high-grade heat energy, the high-grade heat energy is used to heat the cold water flowing through the fuel cell to obtain heated hot water, which is then injected into the heating network.

[0050] Using the above technical solution, the electrothermal system of this application includes a wind farm, a combined heat and power (CHP) unit, a hydrogen energy storage system, a heat pump, and electrical load equipment. The hydrogen energy storage system includes an electrolyzer, a hydrogen storage tank, and a fuel cell. The hydrogen energy storage system, the CHP unit, and the heat pump are coupled together with electricity, thermal power, and hydrogen. The wind farm is used to transmit the overflowing electrical energy generated by the wind farm for use by the electrical load equipment to the heat pump or the hydrogen energy storage system when the electrical energy generated by the wind farm overflows. The hydrogen energy storage system is used to transmit the overflowing electrical energy generated by the fuel cell for use by the electrical load equipment to the power grid when the fuel cell generates high-grade heat energy, and to use the high-grade heat energy to heat the cold water flowing through the fuel cell to obtain heated hot water, which is then injected into the heating network. Therefore, it can be seen that the overflow electrical energy generated by wind farms and hydrogen energy storage systems can be fully utilized in the electric heating system, and the high-grade heat energy generated by fuel cell power generation can be used to heat the hot water in the heating network, realizing the cascade utilization of energy, thereby improving the energy utilization efficiency of the electric heating system and reducing the carbon emissions of the electric heating system. Attached Figure Description

[0051] Various other advantages and benefits will become apparent to those skilled in the art upon reading the following detailed description of preferred embodiments. The accompanying drawings are for illustrative purposes only and are not intended to limit the scope of this application. Furthermore, the same reference numerals denote the same parts throughout the drawings. In the drawings:

[0052] Figure 1 An architectural diagram of an electrothermal system provided in an embodiment of this application;

[0053] Figure 2 An architecture diagram of a hydrogen energy storage system provided in this application embodiment;

[0054] Figure 3 A schematic diagram illustrating the electrothermal energy recovery of a fuel cell according to an embodiment of this application;

[0055] Figure 4 Another architectural diagram of the electrothermal system provided in the embodiments of this application;

[0056] Figure 5 A block diagram illustrating the operating mechanism of an electrothermal system provided in this application embodiment;

[0057] Figure 6 This application provides a diagram showing the relationship between thermal power and electrical power in one operating mode of a combined heat and power unit.

[0058] Figure 7 This is a schematic diagram illustrating the energy utilization process of an electrothermal system provided in an embodiment of this application. Detailed Implementation

[0059] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0060] Figure 1 An optional architecture for the electrothermal system provided in the embodiments of this application, such as Figure 1 As shown, the architecture may include:

[0061] 10 Wind farm, 20 Combined heat and power (CHP) unit, 30 Hydrogen energy storage system, 40 Heat pump and 50 Electrical load equipment.

[0062] Specifically, wind farm 10 can be connected to electrical load equipment to transmit the electrical energy converted from wind energy to electrical load equipment 50. Wind farm 10 can also be connected to heat pump 40 and hydrogen energy storage system 30 respectively, so that it can directly obtain the electrical energy generated by wind farm when heat pump 40 or hydrogen energy storage system 30 needs electricity. Hydrogen energy storage system 30 can be connected to electrical load equipment 50 to transmit the electrical energy converted from hydrogen to electrical load equipment 50. CHP 20 can be connected to electrical load equipment 50 to transmit the generated electrical energy to electrical load equipment 50. Heat pump 40 can be connected to CHP 20 to obtain the electrical energy from CHP 20. Hydrogen energy storage system 30, CHP 20 and heat pump 40 can be coupled together with electricity, thermal power and hydrogen.

[0063] It is understandable that the electrical power in the electric heating system involves the wind farm 10, CHP20, hydrogen energy storage system 30, and electrical load equipment 50, while the thermal power involves the CHP20, hydrogen energy storage system 30, and heat pump 40.

[0064] One architecture of the hydrogen energy storage system 30 is as follows: Figure 2 As shown, the architecture may include an electrolyzer 31, a hydrogen storage tank 32, and a fuel cell 33.

[0065] The wind farm 10 can be used to transfer the overflow electrical energy generated by it to the heat pump 40 or the hydrogen energy storage system 30 when the electrical energy consumed by the power supply load equipment 50 overflows.

[0066] Understandably, due to the characteristics of wind power as a renewable energy source, wind power generation can be a preferred option for providing electrical loads. Therefore, when the wind speed exceeds a preset value, the wind farm 10 will generate excess electrical energy that is consumed by the electrical load equipment 50. This excess electrical energy can power the heat pump 40 or the hydrogen energy storage system 30. Based on this, electrical energy can be converted into heat energy or hydrogen, which is beneficial for the regulation of renewable energy and further reduces the carbon emissions of the electric heating system.

[0067] The hydrogen energy storage system 30 can be used to transmit the overflow energy generated by the fuel cell 33 to the power grid when the electrical energy consumed by the power supply load device 50 is overflowed.

[0068] Understandably, the redox reaction in fuel cell 33 will generate a large amount of electrical energy, which is sufficient to power the load equipment 50 and has surplus power. The surplus power can be fed into the grid. Specifically, the surplus power is DC power, so it can be converted into AC power by an inverter and fed into the grid.

[0069] The hydrogen energy storage system 30 can also be used to heat the cold water flowing through the fuel cell 33 when the fuel cell 33 generates high-grade heat energy, so as to obtain heated hot water and inject the hot water into the heating network.

[0070] Understandably, the redox reaction in fuel cell 33 generates a large amount of high-grade heat energy, which can be used to heat cold water from the heating network. After the cold water flows through fuel cell 33, its temperature rises and it becomes hot water. The hot water can then be injected back into the heating network, allowing the high-grade heat energy to be utilized.

[0071] Specifically, a schematic diagram of the electrothermal energy recovery of the fuel cell 33 in the hydrogen energy storage system 30 is shown below. Figure 3 As shown.

[0072] The electrothermal system provided in this embodiment includes a wind farm, a CHP (hydrogen fuel cell), a hydrogen storage system, a heat pump, and electrical load equipment. The hydrogen storage system includes an electrolyzer, a hydrogen storage tank, and a fuel cell. The hydrogen storage system, the CHP, and the heat pump are coupled together with electricity, thermal power, and hydrogen. The wind farm is used to transmit the overflowing electrical energy generated by the wind farm for use by the electrical load equipment to the heat pump or the hydrogen storage system when the overflowing electrical energy generated by the fuel cell for use by the electrical load equipment is transmitted to the power grid. The hydrogen storage system is used to use the high-grade heat energy generated by the fuel cell to heat the cold water flowing through the fuel cell to obtain heated hot water, which is then injected into the heating network. Therefore, it can be seen that the overflow electrical energy generated by wind farms and hydrogen energy storage systems can be fully utilized in the electric heating system, and the high-grade heat energy generated by fuel cell power generation can be used to heat the hot water in the heating network, realizing the cascade utilization of energy, thereby improving the energy utilization efficiency of the electric heating system and reducing the carbon emissions of the electric heating system.

[0073] based on Figure 1 The architecture of the electric heating system shown is as follows: Figure 4 This application illustrates another architecture of the electrothermal system provided in its embodiments, with reference to... Figure 4 The architecture may include: wind farm 10, CHP20, hydrogen energy storage system 30, heat pump 40, electrical load equipment 50 and thermal load equipment 60.

[0074] The connection relationships between the components of wind farm 10, CHP20, hydrogen energy storage system 30, heat pump 40 and electrical load equipment 50, as well as the functions of each component, correspond one-to-one with the wind farm 10, CHP20, hydrogen energy storage system 30, heat pump 40 and electrical load equipment 50 in the aforementioned embodiments. For details, please refer to the description in the aforementioned embodiments, which will not be repeated here.

[0075] Since the objects involved in the heat power are CHP20, hydrogen energy storage system 30 and heat pump 40, the heat load device 60 can be connected to CHP20, hydrogen energy storage system 30 and heat pump 40 through a heat channel to realize heat transfer.

[0076] Specifically, the thermal power device 60 can consume the heat energy generated by the heat pump 40, the heat energy generated by the CHP20, and the heat energy generated by the fuel cell 33 in the hydrogen energy storage system through the redox reaction.

[0077] based on Figure 4 The electric heating system architecture shown is as follows: Figure 5 This illustrates one operating mechanism of an electric heating system. For example... Figure 5As shown, wind farm 10 can preferentially transmit electrical energy to electrical load device 50, and secondarily to hydrogen energy storage system 30 or heat pump 40. Hydrogen energy storage system 30 can transmit electrical energy to electrical load device 50 and deliver heat energy to heat load device 60. It can recycle hydrogen itself. CHP20 can provide electrical energy to electrical load device 50 and / or heat pump 40 and deliver heat energy to heat load device 60. Heat pump 40 can deliver heat energy to heat load device 60. Electrical load device 50 can consume electrical energy generated by wind farm 10, electrical energy generated by CHP20, and electrical energy generated by hydrogen energy storage system 30. Heat load device 60 can consume heat energy from CHP20, hydrogen energy storage system 30, and heat pump 40.

[0078] In some embodiments of this application, considering the variable efficiency of the fuel cell 33 and the utilization efficiency of high-grade thermal energy, the hydrogen energy storage system 30 is further described. Specifically, the hydrogen energy storage system 30 can also be used for:

[0079] Based on the operating characteristics of electrolyzer 31, hydrogen storage tank 32, and fuel cell 33, the following constraint formulas apply:

[0080]

[0081] in, This represents the amount of hydrogen consumed by electrolyzer 31 in the t-th hour of the day under scenario s. The electrical efficiency of electrolytic cell 31 Let Δt be the electrical power of electrolytic cell 31 in the t-th hour of the day under scenario s, and let Δt be the scheduling interval of the electrothermal system. Let X be a binary variable representing the electrolytic cell 31 at hour t in scenario s. ELE The capacity of electrolytic cell 31, Let f_33 be the electrical power of fuel cell 33 in the t-th hour of the day under scenario s. Let X be a binary variable representing fuel cell 33 at hour t in scenario s. FC For the capacity of fuel cell 33, Let t be the amount of hydrogen stored in hydrogen storage tank 32 in the t-th hour of the day under scenario s. X represents the amount of hydrogen produced by fuel cell 33 in the t-th hour of the day under scenario s. HST For the capacity of hydrogen storage tank 32, This represents the initial state of hydrogen storage tank 32 on that day. This represents the final state of hydrogen storage tank 32 for the day. Let κ be the thermal power of fuel cell 33 in the t-th hour of the day under scenario s. E λ is the first power coefficient of the fuel cell 33. Eκ is the second power coefficient of the fuel cell 33. H λ is the first thermal-work coefficient of the thermal power of fuel cell 33. H The second thermal work coefficient is the thermal power of fuel cell 33.

[0082] Specifically, a scenario can represent a wind power output power scenario.

[0083] Understandably, in power system analysis, to describe the uncertainty of wind power output, multiple curves are typically used to depict the possible daily output power curves of wind power, with each curve representing a scenario. Since the values ​​of the optimization variables vary depending on the wind power output, all of the aforementioned variables are scenario-dependent.

[0084] Considering that both the electrical efficiency and thermal efficiency of fuel cell 33 are related to its rated state, the following efficiency relationship exists:

[0085]

[0086]

[0087] in, α represents the electrical efficiency of the fuel cell under rated operating conditions. E and β E These are the first and second electrical efficiency coefficients of fuel cell 33, respectively, and α. H β H and γ H These are the first thermal efficiency coefficient, the second thermal efficiency coefficient, and the third thermal efficiency coefficient of fuel cell 33, respectively.

[0088] Based on this, substituting the efficiency relationship into the following equation:

[0089]

[0090] It can be obtained

[0091]

[0092] And κ can be obtained E , λ E κ H and λ H .

[0093] The electrothermal system provided in this embodiment, by analyzing the operating characteristics of the electrolyzer 31, the hydrogen storage tank 32, and the fuel cell 33, enables the hydrogen energy storage system 30 to efficiently utilize high-grade thermal energy under multiple constraints.

[0094] In some embodiments of this application, considering the energy cost of the electric heating system, the operating mode of the electric heating system is optimized. Based on this, the electric heating system mentioned in the above embodiments is further described. Specifically, the electric heating system can be used for:

[0095] The hydrogen energy storage system 30 operates according to the various constraint formulas, with the goal of minimizing the equivalent cost, and operates under the constraints of annual equivalent investment cost, annual operating cost, and annual emission cost.

[0096] The minimum equivalent cost is:

[0097] min C tot =C INV +C O&M +C CO2

[0098] Among them, C INV The annual equivalent investment cost is:

[0099]

[0100] C O&M The annual operating cost is:

[0101]

[0102] C CO2 The annual emission cost is:

[0103]

[0104] Where r is the discount rate of the equipment to be installed in the electric heating system, and L is the lifespan of the equipment to be installed in the electric heating system. For the unit investment of the equipment e to be optimized in the electric heating system, X e Let Ψ be the capacity of the device to be optimized (e), Ψ be the set of all devices to be optimized in the electrothermal system, Ω be the set of all scenarios, Γ be the set of all time steps, and ω be the set of all time steps. s Let α be the number of days in a year that scene s occurs. CHP β CHP and γ CHP These are the first cost coefficient, second cost coefficient, and third cost coefficient of CHP20, respectively. Let CHP20 be the electrical power of the CHP20 in the t-th hour of the day under scenario s. Let CHP20 be the thermal power of the CHP20 in scenario s within the t-th hour of the day. Let f be the thermal power of fuel cell 33 in the t-th hour of the day under scenario s. Let the heat pump 40 be the heat output of the heat pump in the t-th hour of the day under scenario s. The unit operation and maintenance cost of electrolytic cell 31, The unit operation and maintenance cost of fuel cell 33, The unit operation and maintenance cost of hydrogen storage tank 32, For the unit operation and maintenance cost of heat pump 40, c CO2 For the carbon unit price, χ E For the carbon emissions of the CHP20 motor set, χ H For the carbon emissions of the CHP20 thermal power unit, B CO2 Free carbon credits.

[0105] In some embodiments of this application, considering the economic factors of the electrothermal system, the capacity of each component of the hydrogen energy storage system 30 can be limited. Based on this, the electrothermal system mentioned in the above embodiments will be further described. This electrothermal system can also be used for:

[0106] It operates under the capacity constraints of hydrogen energy storage systems.

[0107] Specifically, the capacity constraints of hydrogen energy storage systems include a first capacity constraint, a second capacity constraint, and a third capacity constraint.

[0108] The first capacity constraint is that the capacity of the electrolyzer 31 is not greater than the upper limit of the capacity of the electrolyzer 31; the second capacity constraint is that the capacity of the hydrogen storage tank 32 is not greater than the upper limit of the capacity of the hydrogen storage tank 32; and the third capacity constraint is that the capacity of the fuel cell 33 is not greater than the upper limit of the capacity of the fuel cell 33.

[0109] In some embodiments of this application, considering that both electrical power and thermal power in the electric heating system need to be balanced, the electrical power and thermal power of each component in the electric heating system can be limited. Based on this, the electric heating system mentioned in the above embodiments will be further described. This electric heating system can also be used for:

[0110] It operates under both electrical power balance and thermal power balance constraints.

[0111] Specifically, the power balance constraint is as follows:

[0112]

[0113] in, Let t be the electrical power of wind farm 10 in scenario s for the t-th hour of the day. Let 50 be the load power of electrical load equipment in the t-th hour of the day under scenario s. Let t be the electrical power of heat pump 40 in scenario s during the t-th hour of the day.

[0114] The thermal power balance constraint is that, in the same scenario and at the same time period, the thermal load power of the thermal load device 60 is equal to the sum of the thermal power of the heat pump 40, the thermal power of the CHP20, and the thermal power of the fuel cell 33.

[0115] In some embodiments of this application, considering the operating characteristics of the combined heat and power unit CHP20, the electrothermal system can also operate under the constraints of the CHP operating characteristics.

[0116] Specifically, the CHP operating characteristic constraints are as follows:

[0117]

[0118] in, This represents the first critical electrical power of the CHP20 in its preset operating mode. This is the second critical electrical power of the CHP20 in its preset operating mode. This is the third key electrical power of the CHP20 in its preset operating mode. This is the fourth key electrical power of the CHP20 in the preset operating mode. This represents the first critical thermal power of the CHP20 in its preset operating mode. This represents the second key thermal power of the CHP20 in its preset operating mode. This is the third key thermal power of CHP20 in the preset operating mode. This is the fourth key thermal power of CHP20 in the preset operating mode. M represents the operating status of CHP20 in scenario s within the t-th hour of the day. CHP It is a preset constant that is greater than a preset positive value.

[0119] Specifically, the CHP20 cogeneration unit can operate according to a pre-set operating mode. In this operating mode, thermal power and electrical power can have a specific correspondence, described by a curve as follows: Figure 6 As shown, the four vertices of the curve are A (first critical thermal power, first critical electrical power), B (second critical thermal power, second critical electrical power), C (third critical thermal power, third critical electrical power) and D (fourth critical thermal power, fourth critical electrical power).

[0120] In some embodiments of this application, the electric heating system can also operate under the constraints of the heat pump's operating characteristics, taking into account the operating characteristics of the heat pump 40.

[0121] Specifically, the operating characteristics constraints of the heat pump are as follows:

[0122]

[0123] in, Let ρ be the electrical power of heat pump 40 in the t-th hour of the day under scenario s. HP The coefficient of performance (COP) of heat pump 40 is given. This is the upper limit of the heat power of heat pump 40.

[0124] In some embodiments of this application, to facilitate solving the mixed-integer model of the electrothermal system, the constraint formulas mentioned in the above embodiments can be used... Linearize the nonlinear terms.

[0125] Specifically, the Big M method can be used to... Replace with the following group of expressions:

[0126]

[0127] in, It is an auxiliary variable for the bilinear term, which matches the scene and time step, M ELE It can be a preset value that is greater than a preset positive number.

[0128] based on Figure 1 The system architecture shown is as follows: Figure 7 This paper illustrates a flowchart of an energy utilization process for an electrothermal system provided in an embodiment of this application. (Refer to...) Figure 7 The process may include:

[0129] Step S110: When the electrical energy generated by the wind farm 10 for power supply load equipment 50 overflows, the overflow electrical energy of the wind farm 10 is delivered to the heat pump 40 or the hydrogen energy storage system 30.

[0130] Understandably, due to the characteristics of wind power as a renewable energy source, wind power generation can be a preferred option for providing electrical loads. Therefore, when the wind speed exceeds a preset value, the wind farm 10 will generate excess electrical energy that is consumed by the electrical load equipment 50. This excess electrical energy can power the heat pump 40 or the hydrogen energy storage system 30. Based on this, electrical energy can be converted into heat energy or hydrogen, which is beneficial for the regulation of renewable energy and further reduces the carbon emissions of the electric heating system.

[0131] Step S120: When the electrical energy generated by the fuel cell 33 for powering the load device 50 overflows, the overflow electrical energy generated by the fuel cell 33 is transmitted to the power grid.

[0132] Understandably, the redox reaction in fuel cell 33 will generate a large amount of electrical energy, which is sufficient to power the load equipment 50 and has surplus power. The surplus power can be fed into the grid. Specifically, the surplus power is DC power, so it can be converted into AC power by an inverter and fed into the grid.

[0133] Step S130: When the fuel cell 33 generates high-grade heat energy, the high-grade heat energy is used to heat the cold water flowing through the fuel cell 33 to obtain heated hot water, which is then injected into the heating network.

[0134] Understandably, the redox reaction in fuel cell 33 generates a large amount of high-grade heat energy, which can be used to heat cold water from the heating network. After the cold water flows through fuel cell 33, its temperature rises and it becomes hot water. The hot water can then be injected back into the heating network, allowing the high-grade heat energy to be utilized.

[0135] The energy utilization method of the electrothermal system provided in this embodiment involves the following steps: when the electrical energy generated by the wind farm for powering load equipment overflows, the overflow electrical energy is transported to a heat pump or hydrogen storage system; when the electrical energy generated by the fuel cell for powering load equipment overflows, the overflow electrical energy is transported to the power grid; and when the fuel cell generates high-grade heat energy, this high-grade heat energy is used to heat the cold water flowing through the fuel cell to obtain heated hot water, which is then injected into the heating network. Therefore, the electrothermal system can fully utilize the overflow electrical energy generated by the wind farm and hydrogen storage system, and can also use the high-grade heat energy generated by the fuel cell to heat the hot water in the heating network, achieving cascaded energy utilization, thereby improving the energy utilization efficiency of the electrothermal system and reducing its carbon emissions.

[0136] Finally, it should be noted that in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0137] The various embodiments in this specification are described in a progressive manner. Each embodiment focuses on the differences from other embodiments. The various embodiments can be combined as needed, and the same or similar parts can be referred to each other.

[0138] The above description of the disclosed embodiments enables those skilled in the art to make or use this application. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of this application. Therefore, this application is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. An electric heating system, characterized in that, It includes a wind farm, a combined heat and power (CHP) unit, a hydrogen energy storage system, a heat pump, and electrical load equipment. The hydrogen energy storage system includes an electrolyzer, a hydrogen storage tank, and a fuel cell. The hydrogen energy storage system, the CHP unit, and the heat pump are coupled together with electricity, thermal power, and hydrogen. The wind farm is used to transfer the overflowing electrical energy generated by the wind farm for the consumption of the electrical load equipment to the heat pump or the hydrogen energy storage system when the overflowing electrical energy is generated by the wind farm. The hydrogen energy storage system is used to transmit the overflow electrical energy generated by the fuel cell to the power grid when the electrical energy generated by the fuel cell for the power load equipment overflows, and to use the high-grade heat energy to heat the cold water flowing through the fuel cell to obtain heated hot water, so as to inject the hot water into the heating network. The hydrogen energy storage system is also used for: Based on the operating characteristics of the electrolyzer, the hydrogen storage tank, and the fuel cell, the system operates under the following constraint formulas: in, Let be the amount of hydrogen consumed by the electrolyzer in the t-th hour of the day under scenario s. The electrolytic cell has an electrical efficiency. Let be the electrical power of the electrolytic cell in the t-th hour of the day under scenario s. The scheduling interval of the electric heating system. Let be a binary variable representing the electrolytic cell at hour t in scenario s. The capacity of the electrolytic cell is [missing information]. Let be the electrical power of the fuel cell in the t-th hour of the day under scenario s. Let be the binary variable of the fuel cell in scenario s at hour t. The capacity of the fuel cell, Let t be the amount of hydrogen stored in the hydrogen storage tank during the t-th hour of the day in scenario s. Let be the amount of hydrogen produced by the fuel cell in the t-th hour of the day under scenario s. The capacity of the hydrogen storage tank is [missing information]. This represents the initial state of the hydrogen storage tank on that day. This represents the final state of the hydrogen storage tank on that day. Let be the thermal power of the fuel cell in the t-th hour of the day under scenario s. The first power coefficient of the fuel cell is the electrical power coefficient. The second power coefficient of the fuel cell is the electrical power of the fuel cell. The first thermal work coefficient is the thermal power of the fuel cell. The second thermal work coefficient is the thermal power of the fuel cell; The electric heating system is used for: The hydrogen energy storage system operates according to the aforementioned constraint formulas, with the goal of minimizing the equivalent cost, and operates under the constraints of annual equivalent investment cost, annual operating cost, and annual emission cost. The minimum equivalent cost is: in, The annual equivalent investment cost is: The annual operating cost is: The annual emission cost is: Where r is the discount rate of the equipment to be installed in the electric heating system, and L is the lifespan of the equipment to be installed in the electric heating system. For the unit investment of the device e to be optimized in the electric heating system, For the capacity of device e to be optimized, This refers to the set of all devices in the electrothermal system that need to be optimized. A collection of various scenarios. For each time step, Let s be the number of days in a year that scene s appears. , and These are the first cost coefficient, the second cost coefficient, and the third cost coefficient of the CHP, respectively. Let CHP be the electrical power of the CHP in the t-th hour of the day under scenario s. Let CHP be the thermal power of the CHP in the t-th hour of the day under scenario s. Let be the thermal power of the fuel cell in the t-th hour of the day under scenario s. Let be the heat power of the heat pump in the t-th hour of the day under scenario s. The unit operation and maintenance cost of the electrolytic cell, The unit operation and maintenance cost of the fuel cell, The unit operation and maintenance cost of the hydrogen storage tank. The unit operation and maintenance cost of the heat pump is... For carbon unit price, This refers to the carbon emissions of the CHP's motor assembly. This refers to the carbon emissions of the CHP's thermal power unit. Free carbon credits; The electric heating system also includes a heat load device, which is used to consume the heat energy generated by the heat pump, the heat energy generated by the CHP, and the heat energy generated by the hydrogen energy storage system. The electric heating system is also used for: It operates under both electrical power balance and thermal power balance constraints. The power balance constraint is: in, Let be the electrical power of the wind farm in scenario s within the t-th hour of the day. Let be the load power of the electrical load equipment in the t-th hour of the day under scenario s. Let be the electrical power of the heat pump in the t-th hour of the day under scenario s; The thermal power balance constraint is that, in the same scenario and at the same time period, the thermal load power of the thermal load equipment is the sum of the thermal power of the heat pump, the thermal power of the CHP, and the thermal power of the fuel cell; The electric heating system is also used for: It operates under the constraints of CHP's operational characteristics. The CHP operating characteristic constraints are as follows: in, This refers to the first critical electrical power of the CHP in its preset operating mode. This refers to the second critical electrical power of the CHP in the preset operating mode. This refers to the third key electrical power of the CHP in the preset operating mode. This refers to the fourth key electrical power of the CHP in the preset operating mode. This refers to the first critical thermal power of the CHP in the preset operating mode. This refers to the second key thermal power of the CHP in the preset operating mode. This refers to the third key thermal power of the CHP in the preset operating mode. This refers to the fourth key thermal power of the CHP in the preset operating mode. This refers to the operating status of CHP within the t-th hour of the day in scenario s. A preset constant that is greater than a preset positive value; The electric heating system is also used for: It operates under the constraints of heat pump operating characteristics; The operating characteristics of the heat pump are constrained as follows: in, Let be the electrical power of the heat pump in the t-th hour of the day under scenario s. The coefficient of performance (COP) of the heat pump is given. This is the upper limit of the heat power of the heat pump.

2. The electrothermal system according to claim 1, characterized in that, The electric heating system is also used for: The system operates under capacity constraints of a hydrogen energy storage system, which include a first capacity constraint, a second capacity constraint, and a third capacity constraint. The first capacity constraint is that the capacity of the electrolyzer is not greater than the upper limit of the electrolyzer's capacity. The second capacity constraint is that the capacity of the hydrogen storage tank is not greater than the upper limit of the hydrogen storage tank's capacity. The third capacity constraint is that the capacity of the fuel cell is not greater than the upper limit of the fuel cell's capacity.

3. The electrothermal system according to claim 1 or 2, characterized in that, The electrical load equipment is used to consume the electrical energy generated by the wind farm, the electrical energy generated by the hydrogen energy storage system, and the electrical energy generated by the CHP.

4. The electrothermal system according to claim 1 or 2, characterized in that, The CHP is used to deliver the electrical energy it generates to the electrical load equipment and / or the heat pump.

5. A method for utilizing energy in an electrothermal system, characterized in that, Applied to the electric heating system as described in claim 1; The method includes: When the electrical energy generated by the wind farm for the consumption of the electrical load equipment overflows, the overflow electrical energy of the wind farm is delivered to the heat pump or the hydrogen energy storage system. When the electrical energy generated by the fuel cell for the electrical load equipment overflows, the overflow electrical energy generated by the fuel cell is transmitted to the power grid; When the fuel cell generates high-grade heat energy, the high-grade heat energy is used to heat the cold water flowing through the fuel cell to obtain heated hot water, which is then injected into the heating network.

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