An optimal dispatching method for integrated energy system in a park considering exergy economy

Abstract

Based on #imgabs0#economic theory, the present invention constructs an #imgabs4#economic analysis model of an integrated energy system by calculating different types of #imgabs1#flows, establishing #imgabs2#balance equations and cost balance equations of equipment, selecting reasonable cost allocation methods and #imgabs3#loss pricing methods. Then, evaluation indicators of different dimensions are selected to conduct a comprehensive evaluation of the integrated energy system, so as to have a deep understanding of the #imgabs5#economic performance of the integrated energy system, and provide a reference for the construction and result analysis of scheduling problems. On this basis, an optimization scheduling method for a park integrated energy system taking #imgabs6#economic into account is proposed. Taking the total #imgabs7#loss cost of the system as the target, corresponding constraints are established, and finally the commercial solver Gurobi is used to solve the mixed integer nonlinear problem to obtain the optimal scheduling instruction taking #imgabs8#economic into account. The present invention fully considers the energy quality and cost accumulation and allocation effects in the scheduling stage of the integrated energy system, so as to achieve economic and high #imgabs9#operation of the overall system.

Description

Technical Field

[0001] The present invention relates to a method of The invention discloses an economical park integrated energy system optimization dispatching method, belonging to the technical field of multi-energy complementary integrated energy system optimization. Background Art

[0002] The Integrated Energy System (IES) relies on the complementary advantages of multiple energy and multiple equipment to effectively realize the local consumption and utilization of intermittent renewable energy such as wind and solar. It is of great significance to the transformation of the energy system and is an important strategic development direction in the future of the national and international energy field. The integrated energy system is generally composed of various thermal cycles and energy production and conversion equipment to form various system topological structures. This feature makes the integrated energy system more complex than the traditional single energy production system, which can easily lead to instability or even decline in the system's energy utilization level and economic performance. In the context of the heterogeneous characteristics and multiple energy sources of the integrated energy system, the operation and management strategy is a decisive factor affecting the long-term performance of the IES and is of great significance.

[0003] The existing integrated energy system is still far from the ideal sustainable development multi-energy system, so more scheduling methods that take into account energy-saving potential are needed to tap the potential of IES. At present, there are two types of energy efficiency indicators widely used, namely energy indicators based on the first law of thermodynamics, but this indicator can only consider the change in the "quantity" of energy. The integrated energy system usually contains a variety of different types and qualities of energy, so the energy efficiency index based on the second law of thermodynamics is introduced. index. It indicates the highest energy that can be converted into useful work under environmental conditions. This indicator can take into account the changes in both the "quality" and "quantity" of energy. However, the irreversibility generated by different types of equipment within the entire system varies to a certain extent. Multi-objective optimization analysis often ignores this feature. In this context, The advantages of "economics" are highlighted. Economics is the application of thermodynamics It is a discipline that combines concepts with economics, and aims to comprehensively evaluate the value of energy by combining the "quantity" and "quality" of energy with the principle of irreversibility and inequality, and to point out the direction for rational and economical energy use. Specifically, Economics can be applied to the following areas:

[0004] (1) Energy system analysis: Economic analysis evaluates the availability and economic value of different forms of energy and provides a basis for energy selection and policy making.

[0005] (2) Energy conservation and resource optimization: Help enterprises and society find more effective ways to conserve energy, optimize resource allocation, and reduce waste.

[0006] (3) Environmental economics: Consider the impact of energy use on the environment, incorporate environmental costs into economic decision-making, and promote sustainable energy development.

[0007] (4) Technological innovation and development: Encourage innovation in energy technology, improve energy conversion efficiency, and develop new energy resources.

[0008] The application with publication number CN 113159989 B provides “based on Economy and "Heterogeneous Energy System Performance Optimization Method Based on Environmental Analysis" constructs and solves the analysis, economic analysis, and environmental analysis mathematical models of heterogeneous energy systems, uses system efficiency, system economic factors, and system environmental factors as objective functions, studies the system performance of heterogeneous energy systems, including energy utilization level, economic benefits, and ecological performance, and seeks improvement and optimization directions for heterogeneous energy systems. However, it only puts forward improvement suggestions and does not involve the quantitative optimization of the system. It still belongs to the category of system evaluation. Obviously, at present, The application of economics is mainly concentrated in the energy system analysis level, and has not been applied to optimization problems. Therefore, it is urgent to develop a method based on The economics-based optimization and scheduling method for integrated energy systems aims to more objectively and reasonably measure the level of energy utilization, formulate more efficient energy management strategies, and further promote the cascade utilization of energy in integrated energy systems. Summary of the invention

[0009] The present invention provides a method for An economical park integrated energy system optimization dispatching method fully considers the energy quality and cost accumulation and sharing effects in the integrated energy system dispatching stage, so as to achieve economic and high efficiency of the overall system. run.

[0010] The technical solution adopted by the present invention to solve its technical problem is:

[0011] A consideration The economical park integrated energy system optimization scheduling method specifically includes the following steps:

[0012] Step S1: construct a comprehensive energy system model of cold, heat and electricity multi-energy coupling;

[0013] Step S2: Based on Economic theory, building an integrated energy system Economic analysis model is used to reasonably construct the objective function of the optimization problem; evaluation indicators of different dimensions are selected to evaluate the comprehensive energy system Comprehensively evaluate the economic performance of the park, taking into account the differences in energy quality, the accumulation and allocation of costs along the process, and understanding the comprehensive energy system of the park and the various equipment within it. Economic performance, indicating the direction of improvement and the basis for result analysis for scheduling optimization;

[0014] Step S3: Based on the park's integrated energy system and each device within it Economic performance, construct the objective function of the optimization scheduling method, that is, The sum of loss costs is taken as the objective function;

[0015] Step S4: Define the constraints of the optimization scheduling method, take the objective function constructed in step S3 as the optimization target, solve the mixed integer nonlinear programming problem, and obtain Economical optimal dispatch instructions for the integrated energy system of the park;

[0016] As a further preferred embodiment of the present invention, in step S1, the energy forms of the park comprehensive energy system include fossil energy, solar energy, electric energy, thermal energy and cold energy; the equipment for producing, converting and storing the above energy forms includes solid oxide fuel cells, photovoltaic power generation devices, micro-turbines, heat pumps, electric boilers, absorption refrigerators, electric refrigerators, batteries, heat storage tanks and cold storage tanks;

[0017] As a further preferred embodiment of the present invention, in step S2, a comprehensive energy system is constructed. The specific steps of the economic analysis model to reasonably construct the objective function of the optimization problem are:

[0018] Step S21, determine different energy forms in the park's integrated energy system flowing The value calculation method provides a basis for subsequent analysis and evaluation, among which,

[0019] Among fossil energy sources, gas fuel adopts the Rand conversion method:

[0020] Ex fuel =γ f G f R f LHV f ( 1)

[0021] In formula (1), Ex fuel For system gas fuel Value; γ f G is the ratio of gas fuel to its higher calorific value, which is 0.95; f is the fuel flow rate; R f LHV is the ratio of the higher calorific value to the lower calorific value of the gas fuel, which is 1.11;f It is the lower heating value of fuel;

[0022] Electricity is defined as one of the highest energy forms with an effective energy utilization rate of 100%. Equal to electrical energy:

[0023] Ex e =P e (2)

[0024] In formula (2), Ex e For current Value, P e For electrical energy;

[0025] In heat energy and cold energy, hot and cold water flow The values ​​are:

[0026] Ex x =m x [(h x -h0)-T0(s x -s0)] (3)

[0027] In formula (3), Ex x is a water flow in the system Value; m x is the mass flow rate of a water flow in the system; h x is the enthalpy of a water flow in the system; s x is the entropy value of a water flow in the system; T0 is the ambient temperature; h0 is the enthalpy value of the water flow under the ambient state; s0 is the entropy value of the water flow under the ambient state;

[0028] Step S22: Treat each device in the park's integrated energy system as a black box and construct Analyze the black box model and establish the Balance equation and cost balance equation, through The balance equation combines the cost balance equation to relate the cost to the utilization and conversion of energy and determine the reasonable cost allocation method and Loss pricing method;

[0029] Step S23, define each device Lost Unit Economic cost is equal to the unit of output product of the subsystem Economic cost; As a further preferred embodiment of the present invention, in step S22, The equilibrium equation is:

[0030]

[0031] In formula (4), is the fuel flow of the i-th fuel stream of the device value, is the jth product flow of the equipment value, For the device k loss;

[0032] The cost balance equation is:

[0033]

[0034]

[0035]

[0036] In formulas (5), (6) and (7), is the fuel flow of the i-th fuel stream of the device value; The i-th fuel of the device Unit of flow Economic costs; is the jth product flow of the equipment value; This is the jth product of the device Unit of flow Economic cost; Z k is the non-energy cost of the device k; is the investment cost of the equipment k; is the operation and maintenance cost of the device k; R is the return on investment; is the investment cost coefficient of the equipment k; P cap.k is the rated capacity of device k; is the operation and maintenance cost coefficient of equipment k; P k is the actual operating power of equipment k; N is the annual average operating hours of equipment k; r is the bank interest rate, which is 6.7%; y is the service life of the equipment, which is 15 years for all equipment;

[0037] pass The balance equation is combined with the cost balance equation to determine the cost allocation method, and the exponential form of the energy quality coefficient is used as the output Parameters of stream quality differences, specifically:

[0038]

[0039] In formula (8), This is the jth product of the device Unit of flow Economic cost, λ j For the jth unit of the device Energy quality coefficient of the flow;

[0040] Different energy forms in the park's integrated energy system The energy quality coefficient of a flow is defined as:

[0041]

[0042] In formula (9), λ e For electricity Energy quality coefficient of flow; λ h For heat Energy quality coefficient of flow; λ c For cold Energy quality coefficient of flow; T a is the ambient temperature; T h Hot water temperature for the device; T c The temperature of the cold water supplied to the equipment;

[0043] In step S23, define each device Lost Unit Economic cost is equal to the unit of output product of the subsystem Economic costs, specifically:

[0044]

[0045] In formula (10), k for this device Lost Unit Economic costs, This is the jth product of the device Unit of flow Economic costs;

[0046] As a further preferred embodiment of the present invention, in step S2, the integrated energy system Comprehensively evaluate the economic performance of the integrated energy system constructed in steps S21 to S23 Based on the economic analysis model, the comprehensive evaluation is carried out using evaluation indicators of different dimensions. The evaluation indicators include two categories: Evaluation and Economic evaluation;

[0047] In the evaluation, the Efficiency and Loss is used as an evaluation indicator. In economics, the Loss cost and The economic coefficient is used as an evaluation indicator;

[0048] As a further preferred embodiment of the present invention,

[0049] In evaluation, The efficiency is:

[0050]

[0051] In formula (11), η ex For this device efficiency; is the jth product flow of the equipment value; is the fuel flow of the i-th fuel stream of the device value;

[0052] The loss is:

[0053]

[0054] In formula (12), For the device k loss; is the fuel flow of the i-th fuel stream of the device value; is the jth product flow of the equipment value;

[0055] In economics, The loss cost is:

[0056]

[0057] In formula (13), For the device k Loss cost; For the device k loss; k for this device Lost Unit Economic costs;

[0058] The economic coefficient is:

[0059]

[0060] In formula (14), for Economic coefficient; Z k is the non-energy cost of the device k; For the device k loss; k for this device Lost Unit Economic costs;

[0061] As a further preferred embodiment of the present invention, in step S3, the objective function is defined as:

[0062]

[0063] In formula (15), C loss-IES For each device in the system The sum of loss costs, For the device k loss; k for this device Lost Unit Economic cost; in the defined objective function, the photovoltaic power generation device, heat storage tank and cold storage tank The loss is not included in the calculation of the objective function;

[0064] As a further preferred embodiment of the present invention, the step of defining the constraints of the optimization scheduling method in step S4 is:

[0065] Step S41, establishing power balance constraints for electric power, thermal power and cooling power, specifically:

[0066]

[0067] In formula (16), is the output power of the micro-turbine at time t; is the output power of the solid oxide fuel cell at time t; P PV is the output power of the photovoltaic power generation device; is the discharge amount at the tth moment; is the charge amount at time t; is the energy discharge state of the battery at time t, is the charging state of the battery at time t, All are 0-1 variables; is the electrical load at time t; is the electrical power input to the heat pump at time t; is the input power of the electric refrigerator at time t; is the output thermal power of the heat pump at time t; is the output thermal power of the electric boiler at time t; is the heat released at the tth moment; Charge heat for the tth moment; is the energy release state of the heat storage tank at time t, is the charging state of the heat storage tank at time t, All are 0-1 variables; is the heat load at time t; is the input heat power of the absorption refrigerator at time t; is the cooling power output of the absorption chiller at time t; is the cooling power output of the electric refrigerator at time t; is the cooling capacity at the tth moment; The cold charge at the tth moment; is the energy release state of the cold storage tank at time t, are the charging states of the cold storage tank at time t, All are 0-1 variables; is the cooling load at time t;

[0068] Step S42, establishing operating characteristic constraints for each device in the system;

[0069] As a further preferred embodiment of the present invention,

[0070] In step S42, the operating characteristic constraints of each device in the system are established.

[0071] Micro-turbines are:

[0072]

[0073] In formula (17), is the upper limit of the output power of the micro-turbine, is the lower limit of the output power of the micro-turbine;

[0074] Solid oxide fuel cells are:

[0075]

[0076] In formula (18), is the upper limit of the electrical power of solid oxide fuel cells, is the lower limit of the electrical power of solid oxide fuel cells;

[0077] The heat pump is:

[0078]

[0079] In formula (19), is the upper limit of the heat pump power, is the lower power limit of the heat pump;

[0080] Electric boilers are:

[0081]

[0082] In formula (20), is the upper limit of the power of the electric boiler, is the lower power limit of the electric boiler;

[0083] Absorption chillers are:

[0084]

[0085] In formula (21), is the upper limit of the absorption chiller power, is the lower power limit of the absorption chiller;

[0086] The electric refrigerator is:

[0087]

[0088] In formula (22), is the upper limit of the power of the electric refrigerator, is the lower power limit of the electric refrigerator;

[0089] The energy storage equipment model and constraints including batteries, heat storage tanks and cold storage tanks are:

[0090]

[0091]

[0092] E x (1) = E x (24) (25)

[0093] In formula (23), is the upper limit of the power of the energy storage device. The lower power limit of energy storage equipment. The upper limit of the power for charging the energy storage device, is the lower limit of the power for charging the energy storage device; Formula (24) represents the capacity constraint of the energy storage device during operation, E cap,x is the capacity of the energy storage device; Formula (25) indicates that the energy storage state at the end of the dispatch period should be equal to the initial value;

[0094] As a further preferred embodiment of the present invention, the objective function defined in step S3 is used to solve the mixed integer nonlinear programming problem based on the constraints set in steps S41 and S42 using Matlab software and the commercial solver Gurobi to obtain Economical optimal dispatch instructions for integrated energy systems;

[0095] As a further preferred embodiment of the present invention, the objective function defined by formula (15) in step S3 is used to refine the optimization objective function to each device, that is,

[0096]

[0097] Among them, SOFC is a solid oxide fuel cell, MGT is a micro-turbine, HP is a heat pump, EB is an electric boiler, AC is an absorption refrigerator, and EC is an electric refrigerator.

[0098] Through the above technical solution, compared with the prior art, the present invention has the following beneficial effects:

[0099] 1. The present invention provides An economical park integrated energy system optimization scheduling method is first established to Economic analysis and evaluation model, so as to make a more reasonable assessment of the energy utilization level of the integrated energy system and verify the considerations The necessity and importance of economy, and provide reference for the establishment and result analysis of scheduling problems;

[0100] 2. The present invention provides The economical park integrated energy system optimization scheduling method fully considers the differences in energy quality and the accumulation and allocation effects of costs along the process. Multi-objective optimization with efficiency and cost rate as the target is more objective and reasonable, especially suitable for integrated energy systems with multi-energy coupling, which can effectively reduce the system's loss cost, aiming to provide an economical and high-efficiency integrated energy system Provide guidance for operation. BRIEF DESCRIPTION OF THE DRAWINGS

[0101] The present invention is further described below in conjunction with the accompanying drawings and embodiments.

[0102] Figure 1 This is an example equipment diagram of the park integrated energy system provided by the present invention;

[0103] Figure 2 The present invention provides Schematic flow chart of the economical optimization and scheduling method of the integrated energy system of the park. DETAILED DESCRIPTION

[0104] The present invention will now be described in further detail with reference to the accompanying drawings.

[0105] As described in the background technology, the currently introduced Economic theory mainly focuses on the analysis of energy systems, but has not been truly applied to optimization problems. This application aims to provide a method that takes into account An economical optimization scheduling method for integrated energy system in a park. Based on economics, it is applied to the optimization and scheduling problems of integrated energy systems to more objectively and reasonably measure the level of energy utilization and formulate more efficient energy management strategies.

[0106] Figure 2 As shown, the specific steps include:

[0107] Step S1: construct a comprehensive energy system model of cold, heat and electricity multi-energy coupling;

[0108] The overall architecture of the park's integrated energy system is established here to lay the foundation for the model for subsequent work, so the energy forms it covers are as comprehensive as possible. Figure 1 As shown, the park integrated energy system (IES) provided includes fossil energy, solar energy, electric energy, thermal energy and cold energy; the specific equipment for producing, converting and storing the above energy forms includes but is not limited to solid oxide fuel cells (SOFC), photovoltaic power generation devices (PV), micro gas turbines (MGT), heat pumps (HP), electric boilers (EB), absorption chillers (AC), electric chillers (EC), batteries, heat storage tanks and cold storage tanks.

[0109] Step S2: Based on Economic theory, building an integrated energy system Economic analysis model is used to reasonably construct the objective function of the optimization problem; evaluation indicators of different dimensions are selected to evaluate the comprehensive energy system Comprehensively evaluate the economic performance of the park, taking into account the differences in energy quality, the accumulation and allocation of costs along the process, and understanding the comprehensive energy system of the park and the various equipment within it. Economic performance, indicating the direction of improvement and the basis for result analysis for scheduling optimization;

[0110] Step S2 can be divided into two parts for specific analysis. The first part is to build a comprehensive energy system. Economic analysis model is to understand the quality and utilization efficiency of different forms of energy in order to optimize the design and improvement of the system and improve the overall energy utilization efficiency.

[0111] The specific steps for construction are:

[0112] Step S21: Most of the park integrated energy systems involve multiple energy flows, as described in the previous section, including but not limited to fossil energy, solar energy, electrical energy, thermal energy, cold energy, etc. flowing The calculation methods of the values ​​are different, the representative ones are as follows:

[0113] Among fossil energy sources, gas fuel adopts the Rand conversion method:

[0114] Ex fuel =γ f G f R f LHV f (1)

[0115] In formula (1), Ex fuel For system gas fuel Value; γ f G is the ratio of gas fuel to its higher calorific value, which is 0.95; f is the fuel flow rate; R f LHV is the ratio of the higher calorific value to the lower calorific value of the gas fuel, which is 1.11; f It is the lower heating value of fuel;

[0116] Electricity is defined as one of the highest energy forms with an effective energy utilization rate of 100%. Equal to electrical energy:

[0117] Ex e =P e (2)

[0118] In formula (2), Ex e For current Value, P e For electrical energy;

[0119] In heat energy and cold energy, hot and cold water flow The values ​​are:

[0120] Ex x =m x [(h x -h0)-T0(s x -s0)] (3)

[0121] In formula (3), Ex x is a water flow in the system Value; m x is the mass flow rate of a water flow in the system; h x is the enthalpy of a water flow in the system; s x is the entropy value of a water flow in the system; T0 is the ambient temperature; h0 is the enthalpy value of the water flow under the ambient state; s0 is the entropy value of the water flow under the ambient state;

[0122] Step S22: Treat each device in the park's integrated energy system as a black box and construct Analyze the black box model (no need to consider the specific internal process here, just focus on the energy flow of the device input and output), and establish the energy flow of each device based on the "fuel-product" theory. Balance equation and cost balance equation,

[0123] in, The equilibrium equation is:

[0124]

[0125] In formula (4), is the fuel flow of the i-th fuel stream of the device value, is the jth product flow of the equipment value, For the device k loss;

[0126] The cost balance equation is:

[0127]

[0128]

[0129]

[0130] In formulas (5), (6) and (7), is the fuel flow of the i-th fuel stream of the device value; The i-th fuel of the device Unit of flow Economic costs; is the jth product flow of the equipment value; This is the jth product of the device Unit of flow Economic cost; Z k is the non-energy cost of the device k; is the investment cost of the equipment k; is the operation and maintenance cost of the device k; R is the return on investment; is the investment cost coefficient of the equipment k; P cap.k is the rated capacity of device k; is the operation and maintenance cost coefficient of equipment k; P k is the actual operating power of equipment k; N is the annual average operating hours of equipment k; r is the bank interest rate, which is 6.7%; y is the service life of the equipment, which is 15 years for all equipment;

[0131] The cost balance equation reflects the relationship between the income and expenditure of the cost in the system. Through the cost balance equation, the source and destination of each cost in the system can be clarified, and the cost can be more accurately associated with the utilization and conversion of energy. Further, it is necessary to determine a reasonable cost allocation method and Loss pricing method.

[0132] When a device has multiple outputs When streaming, you need to choose an appropriate cost allocation method for the output The total cost of the flow is amortized to obtain each output Unit of flow Economic costs. A reasonable cost allocation method should reflect the horizontal Economic inequality, combined with the cost balance equation Balance equations, this step uses a method based on output The cost allocation method of flow quality is in the form of exponential energy quality coefficient e λ As reflected output Parameters of stream quality differences, specifically:

[0133]

[0134] In formula (8), This is the jth product of the device Unit of flow Economic cost, λ j For the jth unit of the device Energy quality coefficient of the flow;

[0135] Different forms of energy in the park's integrated energy system The energy quality coefficient of a flow is defined as:

[0136]

[0137] In formula (9), λ e For electricity Energy quality coefficient of flow; λ h For heat Energy quality coefficient of flow; λ c For cold Energy quality coefficient of flow; T a is the ambient temperature; T h Hot water temperature for the device; T c The temperature of the cold water supplied to the equipment;

[0138] Step S23: The construction of the objective function also requires the definition of the system components The unit cost of loss is the loss of energy. Since the transfer of energy is directional, all non-spontaneous processes of energy must pay a price. The price is the reduction of energy quality or quantity, and the decrease of work capacity. That is, all non-spontaneous processes of energy produce Loss. As a driving force, it promotes the energy transfer and conversion process. Therefore, the definition of each device Lost Unit Economic cost is equal to the unit of output product of the subsystem Economic costs, specifically:

[0139]

[0140] In formula (10), k for this device Lost Unit Economic costs, This is the jth product of the device Unit of flow Economic cost.

[0141] Steps S21-S23 build a comprehensive energy system Economic analysis model, in order to more accurately understand the system In order to optimize the scheduling and formulate a more reasonable operation plan, it is also necessary to use evaluation indicators of different dimensions to evaluate the comprehensive energy system. The second part of this step is to conduct a comprehensive evaluation of the economic analysis model.

[0142] The so-called multi-dimensionality means that the evaluation indicators cover Evaluation and Economic evaluation; In the evaluation, the Efficiency and Loss is used as an evaluation indicator. In economics, the Loss cost and The economic coefficient is used as an evaluation indicator.

[0143] Specifically, The efficiency is:

[0144]

[0145] In formula (11), η ex For this device efficiency; is the jth product flow of the equipment value; is the fuel flow of the i-th fuel stream of the device value;

[0146] The loss is:

[0147]

[0148] In formula (12), For the device k loss; is the fuel flow of the i-th fuel stream of the device value; is the jth product flow of the equipment value;

[0149] The loss cost is:

[0150]

[0151] In formula (13), for Loss cost; For the device k loss; k for this device Lost Unit Economic costs;

[0152] The economic coefficient is:

[0153]

[0154] In formula (14), for Economic coefficient; Z k is the non-energy cost of the device k; For the device k loss; k for this device Lost Unit Economic cost.

[0155] Step S3: One of the innovations of this application is to use the system as a whole The loss cost of each device in the system The sum of the loss and damage costs is used as the objective function for constructing the scheduling problem. For energy storage equipment and "green power" equipment using renewable energy, such as photovoltaics and wind turbines, their Losses are caused, so “green electricity” equipment and energy storage equipment are not included in the calculation of the objective function.

[0156] The objective function is defined as:

[0157]

[0158] In formula (15), C loss-IES For each device in the system The sum of loss costs, For the device k loss; k for this device Lost Unit Economic cost; in the defined objective function, the photovoltaic power generation device, heat storage tank and cold storage tank The loss is not included in the calculation of the objective function.

[0159] Step S4: After determining the objective function of the optimization scheduling method, it is also necessary to define the constraints of the optimization scheduling method, and then establish an optimization scheduling model for the integrated energy system to perform optimization and solve the problem to obtain the optimal output of the equipment at each moment.

[0160] Taking solid oxide fuel cells (SOFC), micro gas turbines (MGT), heat pumps (HP), electric boilers (EB), absorption chillers (AC) and electric chillers (EC) as examples, the method of establishing constraints is explained, specifically:

[0161] Step S41, establishing power balance constraints for electric power, thermal power and cooling power, specifically:

[0162]

[0163] In formula (16), is the output power of the micro-turbine at time t; is the output power of the solid oxide fuel cell at time t; P PV is the output power of the photovoltaic power generation device; is the discharge amount at the tth moment; is the charge amount at time t; is the energy discharge state of the battery at time t, is the charging state of the battery at time t, All are 0-1 variables; is the electrical load at time t; is the electrical power input to the heat pump at time t; is the input power of the electric refrigerator at time t; is the output thermal power of the heat pump at time t; is the output thermal power of the electric boiler at time t; is the heat released at the tth moment; Charge heat for the tth moment; is the energy release state of the heat storage tank at time t, is the charging state of the heat storage tank at time t, All are 0-1 variables; is the heat load at time t; is the input heat power of the absorption refrigerator at time t; is the cooling power output of the absorption chiller at time t; is the cooling power output of the electric refrigerator at time t; is the cooling capacity at the tth moment; The cold charge at the tth moment; is the energy release state of the cold storage tank at time t, are the charging states of the cold storage tank at time t, All are 0-1 variables; is the cooling load at time t;

[0164] Step S42, establishing the operating characteristic constraints of each device in the system, wherein:

[0165] ⑴Micro-turbine is:

[0166]

[0167] In formula (17), is the upper limit of the output power of the micro-turbine, is the lower limit of the output power of the micro-turbine;

[0168] ⑵ Solid oxide fuel cells are:

[0169]

[0170] In formula (18), is the upper limit of the electrical power of solid oxide fuel cells, is the lower limit of the electrical power of solid oxide fuel cells;

[0171] ⑶The heat pump is:

[0172]

[0173] In formula (19), is the upper limit of the heat pump power, is the lower power limit of the heat pump;

[0174] ⑷ Electric boiler:

[0175]

[0176] In formula (20), is the upper limit of the power of the electric boiler, is the lower power limit of the electric boiler;

[0177] ⑸ Absorption refrigeration machine is:

[0178]

[0179] In formula (21), is the upper limit of the absorption chiller power, is the lower power limit of the absorption chiller;

[0180] (6) Electric refrigerator:

[0181]

[0182] In formula (22), is the upper limit of the power of the electric refrigerator, is the lower power limit of the electric refrigerator;

[0183] ⑺ The energy storage equipment model and constraints including batteries, heat storage tanks and cold storage tanks are:

[0184]

[0185]

[0186] E x (1) = E x (24) (25)

[0187] In formula (23), is the upper limit of the power of the energy storage device. The lower power limit of energy storage equipment. The upper limit of the power for charging the energy storage device, is the lower limit of the power for charging the energy storage device; Formula (24) represents the capacity constraint of the energy storage device during operation, E cap,x is the capacity of the energy storage device; formula (25) indicates that the energy storage state at the end of the scheduling period should be equal to the initial value.

[0188] Based on the objective function defined in step S3, the optimization objective function is refined to each device, that is,

[0189]

[0190] Combined with the constraints of formula (16)-formula (25) set in step S41-step S42, the output of each device in the system is optimized to obtain the optimal scheduling plan for the integrated energy system under typical meteorological and user load scenarios. Specifically, Matlab software and the commercial solver Gurobi are used to solve the mixed integer nonlinear programming problem, and the optimal scheduling plan is obtained. The optimal dispatching instructions for the economical integrated energy system complete the entire optimization dispatching method.

[0191] In summary, this application is first based on Economic theory, by calculating different types of flow, establish the device Balance equation, cost balance equation, choose a reasonable cost allocation method and Loss pricing method, building a comprehensive energy system Economic analysis model. Then select evaluation indicators of different dimensions to conduct a comprehensive evaluation of the integrated energy system to gain a deeper understanding of the integrated energy system. Economic performance, and provide a reference for the construction and result analysis of scheduling problems. On this basis, a comprehensive consideration system An economical integrated energy system optimization dispatching method based on the total The loss cost is taken as the target, the corresponding constraints are established, and finally the mixed integer nonlinear problem is solved by using the commercial solver Gurobi. The application effectively reduces the system's available energy loss cost and helps achieve high efficiency of the integrated energy system. Economic operation and promote the sustainable development of the integrated energy system.

[0192] It will be understood by those skilled in the art that, unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as those generally understood by those skilled in the art to which this application belongs. It should also be understood that terms such as those defined in common dictionaries should be understood to have meanings consistent with the meanings in the context of the prior art, and will not be interpreted with idealized or overly formal meanings unless defined as herein.

[0193] The meaning of "and / or" described in this application means that the situations where each exists alone or both exist at the same time are included.

[0194] The term “connection” as used in this application may mean a direct connection between components or an indirect connection between components via other components.

[0195] Based on the above ideal embodiments of the present invention, the relevant staff can make various changes and modifications without departing from the technical concept of the present invention through the above description. The technical scope of the present invention is not limited to the contents of the specification, and its technical scope must be determined according to the scope of the claims.

Claims

1. A consideration The economical park integrated energy system optimization scheduling method is characterized by: The specific steps include: Step S1: construct a comprehensive energy system model of cold, heat and electricity multi-energy coupling; Step S2: Based on Economic theory, building an integrated energy system Economic analysis model to reasonably construct the objective function of the optimization problem; The specific steps are: Step S21, determine different energy forms in the park's integrated energy system flowing The value calculation method provides a basis for subsequent analysis and evaluation, among which, Among fossil energy sources, gas fuel adopts the Rand conversion method: Ex fuel =γ f G f R f LHV f (1) In formula (1), Ex fuel For system gas fuel Value; γ f G is the ratio of gas fuel to its higher calorific value, which is 0.95; f is the fuel flow rate; R f LHV is the ratio of the higher calorific value to the lower calorific value of the gas fuel, which is 1.11; f It is the lower heating value of fuel; Electricity is defined as one of the highest energy forms with an effective energy utilization rate of 100%. Equal to electrical energy: From e =P e (2) In formula (2), Ex e For current Value, P e For electrical energy; In heat energy and cold energy, hot and cold water flow The values ​​are: Ex x =m x [(h x -h0)-T0(s x -s0)] (3) In formula (3), Ex x is a water flow in the system Value; m x is the mass flow rate of a water flow in the system; h x is the enthalpy of a water flow in the system; s x is the entropy value of a water flow in the system; T0 is the ambient temperature; h0 is the enthalpy value of the water flow under the ambient state; s0 is the entropy value of the water flow under the ambient state; Step S22: Treat each device in the park's integrated energy system as a black box and construct Analyze the black box model and establish the Balance equation and cost balance equation, through The balance equation combines the cost balance equation to relate the cost to the utilization and conversion of energy and determine the reasonable cost allocation method and Loss pricing method; The equilibrium equation is: In formula (4), is the fuel flow of the i-th fuel stream of the device value, is the jth product flow of the equipment value, For the device k loss; The cost balance equation is: In formulas (5), (6) and (7), is the fuel flow of the i-th fuel stream of the device value; The i-th fuel of the device Unit of flow Economic costs; is the jth product flow of the equipment value; This is the jth product of the device Unit of flow Economic cost; Z k is the non-energy cost of the device k; is the investment cost of the equipment k; is the operation and maintenance cost of the device k; R is the return on investment; is the investment cost coefficient of the equipment k; P cap.k is the rated capacity of device k; is the operation and maintenance cost coefficient of equipment k; P k is the actual operating power of equipment k; N is the annual average operating hours of equipment k; r is the bank interest rate, which is 6.7%; y is the service life of the equipment, which is 15 years for all equipment; pass The balance equation is combined with the cost balance equation to determine the cost allocation method, and the exponential form of the energy quality coefficient is used as the output Parameters of stream quality differences, specifically: In formula (8), This is the jth product of the device Unit of flow Economic cost, λ j For the jth unit of the device Energy quality coefficient of the flow; Different energy forms in the park's integrated energy system The energy quality coefficient of a flow is defined as: In formula (9), λ e For electricity Energy quality coefficient of flow; λ h For heat Energy quality coefficient of flow; λ c For cold Energy quality coefficient of flow; T a is the ambient temperature; T h Hot water temperature for the device; T c The temperature of the cold water supplied to the equipment; Step S23, define each device Lost Unit Economic cost is equal to the unit of output product of the subsystem Economic costs; Specifically: In formula (10), k for this device Loss Unit Economic costs, This is the jth product of the device Unit of flow Economic costs; Select evaluation indicators of different dimensions to evaluate the integrated energy system Comprehensively evaluate the economic performance of the integrated energy system constructed in steps S21 to S23 Based on the economic analysis model, the comprehensive evaluation is carried out using evaluation indicators of different dimensions. The evaluation indicators include two categories: Evaluation and Economic evaluation; In the evaluation, the Efficiency and Loss is used as an evaluation indicator. In economics, the Loss cost and The economic coefficient is used as an evaluation indicator; the difference in energy quality, the accumulation and allocation effect of costs along the process are considered to understand the integrated energy system of the park and the various equipment within it. Economic performance, indicating the direction of improvement and the basis for result analysis for scheduling optimization; In evaluation, The efficiency is: In formula (11), η ex For this device efficiency; is the jth product flow of the equipment value; is the fuel flow of the i-th fuel stream of the device value; The loss is: In formula (12), For the device k loss; is the fuel flow of the i-th fuel stream of the device value; is the jth product flow of the equipment value; In economics, The loss cost is: In formula (13), For the device k Loss cost; For the device k loss; k for this device Loss Unit Economic costs; The economic coefficient is: In formula (14), for Economic coefficient; Z k is the non-energy cost of the device k; For the device k loss; k for this device Loss Unit Economic costs; Step S3: Based on the park's integrated energy system and each device within it Economic performance, construct the objective function of the optimization scheduling method, that is, The sum of loss costs is taken as the objective function; The objective function is defined as: In formula (15), C loss-IES For each device in the system The sum of loss costs, For the device k loss; k for this device Loss Unit Economic cost; in the defined objective function, the photovoltaic power generation device, heat storage tank and cold storage tank The loss is not included in the calculation of the objective function; Step S4: Define the constraints of the optimization scheduling method, take the objective function constructed in step S3 as the optimization target, solve the mixed integer nonlinear programming problem, and obtain Economical optimal dispatching instructions for the integrated energy system of a park.

2. The method according to claim 1 The economical park integrated energy system optimization scheduling method is characterized by: In step S1, the energy forms of the park's comprehensive energy system include fossil energy, solar energy, electrical energy, thermal energy and cold energy; the equipment for producing, converting and storing the above energy forms includes solid oxide fuel cells, photovoltaic power generation devices, micro-turbines, heat pumps, electric boilers, absorption refrigerators, electric refrigerators, batteries, heat storage tanks and cold storage tanks.

3. The method according to claim 1 The economical park integrated energy system optimization scheduling method is characterized by: The steps of defining the constraints of the optimization scheduling method in step S4 are: Step S41, establishing power balance constraints for electric power, thermal power and cooling power, specifically: In formula (16), is the output power of the micro-turbine at time t; is the output power of the solid oxide fuel cell at time t; P PV is the output power of the photovoltaic power generation device; is the discharge amount at the tth moment; is the charge amount at time t; is the energy discharge state of the battery at time t, is the charging state of the battery at time t, All are 0-1 variables; is the electrical load at time t; is the electrical power input to the heat pump at time t; is the input power of the electric refrigerator at time t; is the output thermal power of the heat pump at time t; is the output thermal power of the electric boiler at time t; is the heat released at the tth moment; Charge heat for the tth moment; is the energy release state of the heat storage tank at time t, is the charging state of the heat storage tank at time t, All are 0-1 variables; is the heat load at time t; is the input heat power of the absorption refrigerator at time t; is the cooling power output of the absorption chiller at time t; is the cooling power output of the electric refrigerator at time t; is the cooling capacity at the tth moment; The cold charge at the tth moment; is the energy release state of the cold storage tank at time t, are the charging states of the cold storage tank at time t, All are 0-1 variables; is the cooling load at time t; Step S42: Establishing operating characteristic constraints for each device in the system.

4. The method according to claim 3 The economical park integrated energy system optimization scheduling method is characterized by: In step S42, the operating characteristic constraints of each device in the system are established. Micro-turbines are: In formula (17), is the upper limit of the output power of the micro-turbine, is the lower limit of the output power of the micro-turbine; Solid oxide fuel cells are: In formula (18), is the upper limit of the electrical power of solid oxide fuel cells, is the lower limit of the electrical power of solid oxide fuel cells; The heat pump is: In formula (19), is the upper limit of the heat pump power, is the lower power limit of the heat pump; Electric boilers are: In formula (20), is the upper limit of the power of the electric boiler, is the lower power limit of the electric boiler; Absorption chillers are: In formula (21), is the upper limit of the absorption chiller power, is the lower power limit of the absorption chiller; The electric refrigerator is: In formula (22), is the upper limit of the power of the electric refrigerator, is the lower power limit of the electric refrigerator; The energy storage equipment model and constraints including batteries, heat storage tanks and cold storage tanks are: AND x (1)=And x (24) (25) In formula (23), is the upper limit of the power of the energy storage device. The lower power limit of energy storage equipment. The upper limit of the power for charging the energy storage device, is the lower limit of the power for charging the energy storage device; Formula (24) represents the capacity constraint of the energy storage device during operation, E cap,x is the capacity of the energy storage device; formula (25) indicates that the energy storage state at the end of the scheduling period should be equal to the initial value.

5. The method according to claim 1 The economical park integrated energy system optimization scheduling method is characterized by: Using the objective function defined in step S3 and the constraints set in steps S41 and S42, the mixed integer nonlinear programming problem is solved using Matlab software and the commercial solver Gurobi, and the solution is obtained. Optimal dispatch instructions for economical integrated energy systems.

6. The method according to claim 1 The economical park integrated energy system optimization scheduling method is characterized by: Using the objective function defined by formula (15) in step S3, the optimization objective function is refined to each device, that is, Among them, SOFC is a solid oxide fuel cell, MGT is a micro-turbine, HP is a heat pump, EB is an electric boiler, AC is an absorption refrigerator, and EC is an electric refrigerator.

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