A multi-energy supply system coordinated scheduling method

Abstract

The present application relates to a kind of multi-energy supply system collaborative scheduling method, the method is based on the multi-time scale operation strategy of ground source heat pump, the method specifically includes the following steps: step 1: obtaining the cold load, heat load and electric load of system energy supply building;Step 2: construct solar energy-geothermal energy-natural gas complementary energy supply system;Step 3: determine the scheduling strategy of solar energy-geothermal energy-natural gas complementary energy supply system;Step 4: establish the optimization model of solar energy-geothermal energy-natural gas complementary energy supply system;Step 5: refine the decision variable of solar energy-geothermal energy-natural gas complementary energy supply system.Compared with prior art, the present application has improved the economic, energy and environmental performance and other advantages of energy supply system.

Description

Technical Field

[0001] This invention relates to an energy system, and more particularly to a method for coordinated scheduling of multi-energy supply systems based on a ground-source heat pump multi-timescale operation strategy. Background Technology

[0002] The multi-energy supply system is a complementary system of solar energy, geothermal energy, and natural gas. In the prior art, Chinese Patent Publication No. CN113962438A discloses a combined optimization system and method for a hybrid energy system of cooling, heating, and electricity, such as... Figure 1 As shown, this paper proposes a scheduling optimization model for a microgrid system with hybrid energy (cooling, heating, and electricity) that aims to minimize both operating costs and CO2 emissions. The model solves for the optimal set of global energy scheduling that meets user demand for hybrid energy. The main input energy sources are the power grid, solar energy, geothermal energy, and natural gas. The hybrid system consists of batteries, photovoltaic modules, a ground source heat pump, a gas boiler, and an absorption chiller. The primary objectives are minimizing operating costs and CO2 emissions. While the existing patent's hybrid energy system includes batteries, photovoltaic modules, a ground source heat pump, a gas boiler, and an absorption chiller, and its optimization objective is low operating costs and minimal environmental pollution, it does not consider system construction costs. This results in a situation where, despite achieving the optimization objectives of minimizing operating costs and CO2 emissions, the system's construction cost is high.

[0003] The published paper, "Optimization Study of a Combined Cooling, Heating, and Power System and its Coupling System with a Ground Source Heat Pump," proposes a multi-objective optimization model for a CCHP-GSHP coupled system consisting of a gas turbine (including a heat recovery device), an absorption chiller, a heat exchanger, a boiler, a thermal storage device, and a ground source heat pump. In this multi-objective optimization model, combined with an electricity-driven, heat-dependent operation strategy, the rated electrical capacity of the prime mover, the proportion of cooling provided by the ground source heat pump to the total cooling capacity, the proportion of heating provided by the ground source heat pump to the total heating capacity, and key parameters determining whether the unit should be turned on are used as optimization variables. Simultaneously, the environmental, energy, and economic performance of the coupled system are considered as optimization objectives, and a genetic algorithm is used to solve the optimization problem. This existing literature proposes a multi-objective optimization model for a CCHP-GSHP coupled system consisting of a gas turbine (including a heat recovery device), an absorption chiller, a heat exchanger, a boiler, a thermal storage device, and a ground source heat pump. In this multi-objective optimization model, the proportions of cooling capacity provided by the ground source heat pump to the total cooling capacity and the proportions of heating capacity provided by the ground source heat pump to the total heating capacity are both set to constant values. This fails to reflect the operational flexibility of the ground source heat pump and cannot fully explore the environmental, energy, and economic performance of the coupled system.

[0004] Therefore, for a solar-geothermal-natural gas complementary energy supply system, how to establish more diversified ground source heat pump operation strategies to enhance the refined coordinated operation of each unit, and improve the economic, energy and environmental performance of the energy supply system by adopting appropriate ground source heat pump operation strategies, has become a technical problem that needs to be solved. Summary of the Invention

[0005] The purpose of this invention is to overcome the shortcomings of the existing technology and provide a method for coordinated scheduling of multi-energy supply systems, thereby improving the economic, energy and environmental performance of the energy supply system.

[0006] The objective of this invention can be achieved through the following technical solutions:

[0007] According to one aspect of the present invention, a method for coordinated scheduling of multi-energy supply systems is provided. This method is based on a multi-timescale operation strategy for ground-source heat pumps, and specifically includes the following steps:

[0008] Step 1: Obtain the cooling load, heating load, and electrical load of the building powered by the system;

[0009] Step 2: Construct a complementary energy supply system of solar energy, geothermal energy, and natural gas;

[0010] Step 3: Determine the scheduling strategy for the complementary energy supply system of solar-geothermal-natural gas;

[0011] Step 4: Establish an optimization model for a complementary energy supply system of solar energy, geothermal energy, and natural gas;

[0012] Step 5: Refine the decision variables for the complementary energy supply system of solar-geothermal-natural gas.

[0013] As a preferred technical solution, in step 1, for buildings already in use, the building's cooling load, heating load, and electrical load data are collected; for unused buildings, the building environment simulation analysis software DeST is used to calculate the building's cooling load, heating load, and electrical load data.

[0014] As a preferred technical solution, in step 2, the equipment of the solar-geothermal-natural gas complementary energy supply system includes: an internal combustion engine, an absorption chiller / water heater, photovoltaic power, solar thermal power, ground source heat pump, gas boiler, battery, water tank, and municipal power grid; wherein the internal combustion engine, photovoltaic power, battery, and municipal power grid can meet the electrical load of the user and the ground source heat pump; the absorption chiller / water heater, ground source heat pump, and water tank can meet the user's heat load and cooling load; the heat source of the absorption chiller / water heater includes the internal combustion engine, solar thermal power, and gas boiler.

[0015] As a preferred technical solution, in step 3, the scheduling strategy of the solar-geothermal-natural gas complementary energy supply system includes: under the electric follower strategy, the energy supply system prioritizes meeting the electrical load, and then meets the thermal load and cooling load.

[0016] As a preferred technical solution, for electrical load, when the electricity from photovoltaics exceeds the electrical load, the excess is preferentially stored in batteries, and if there is still surplus, it is sold to the municipal power grid; conversely, batteries are used to supplement the shortage of electrical energy; if the electricity provided by photovoltaics and batteries cannot meet the electrical load, the insufficient electrical energy is supplemented by the internal combustion engine or the municipal power grid; when the insufficient electrical energy is lower than the minimum power generation of the internal combustion engine, it is met by the municipal power grid; if the insufficient electrical energy is higher than the minimum power generation of the internal combustion engine but lower than the maximum power generation of the internal combustion engine, it is met by the internal combustion engine; if the insufficient electrical energy is higher than the maximum power generation of the internal combustion engine, it is met by both the internal combustion engine and the municipal power grid.

[0017] As a preferred technical solution, for heat load or cooling load, the operation mode of the ground source heat pump is improved by introducing heating and cooling ratio coefficients of the ground source heat pump at different time scales. The ground source heat pump prioritizes to provide a certain proportion of heat load or cooling load, and the remaining heat load or cooling load is met by absorption chillers and water storage tanks.

[0018] If the heat or cooling provided by the absorption chiller exceeds the remaining heat or cooling load, the excess is preferentially stored in the storage tank, and any remaining heat or cooling is discharged into the environment. Conversely, the storage tank is used to supplement the shortfall in heat or cooling. If the heat or cooling provided by the absorption chiller and storage tank cannot meet the remaining heat or cooling load, the gas boiler provides a certain amount of heat energy to the absorption chiller to increase its heat or cooling output and meet the remaining heat or cooling load.

[0019] As a preferred technical solution, the proportional coefficient includes a quarterly coefficient, a monthly coefficient, and a daily coefficient.

[0020] As a preferred technical solution, in step 4, the optimization model of the solar-geothermal-natural gas complementary energy supply system includes: taking the annual cost, primary energy consumption, and carbon dioxide emissions as objective functions, taking equipment output constraints and power balance constraints as constraints, and taking the capacity of internal combustion engine, photovoltaic, solar thermal, storage battery, water storage tank, and the heating ratio and cooling ratio of ground source heat pump as decision variables; then, a multi-objective genetic algorithm and the TOPSIS method are used to solve the model.

[0021] As preferred technical solutions, the first scenario involves using a quarterly coefficient for the operation of the ground source heat pump, with one heating coefficient for the heating season and one cooling coefficient for the cooling season, totaling two coefficients. The second scenario involves using a monthly coefficient for the operation of the ground source heat pump, with one energy supply coefficient required for each month of both the heating and cooling seasons, totaling nine coefficients. The third scenario involves using a daily coefficient for the operation of the ground source heat pump, with a total of 212 days in both the heating and cooling seasons, resulting in a total of 212 energy supply coefficients.

[0022] As a preferred technical solution, the objective function is as follows:

[0023] a1) Annual cost

[0024]

[0025] In the formula, N m C m and l m These represent the capacity, unit investment cost, and service life of the m-th device, respectively; r is the discount rate; ε is the maintenance factor; C ng C grid,im and C grid,ex These are the prices of natural gas, electricity purchase, and electricity sales; F pgu and F b These are the natural gas consumption figures for internal combustion engines and gas-fired boilers, respectively; E grid,im and E grid,ex These are the purchased electricity volume and the sold electricity volume;

[0026] a2) Primary energy consumption

[0027]

[0028] In the formula, η pp and η grid These are the power efficiencies of power plants and power grids, respectively.

[0029] a3) Carbon dioxide emissions

[0030]

[0031] In the formula, λ ng and λ grid These are the carbon dioxide emissions from natural gas and municipal power grids, respectively.

[0032] The constraints are as follows:

[0033] b1) Equipment output constraints

[0034] internal combustion engine:

[0035] E pgu =F pgu ηe,pgu

[0036] Q pgu =F pgu (1-η e,pgu -η h,loss )

[0037] 0.3N pgu ≤E pgu ≤N pgu

[0038] In the formula, E pgu Q pgu F pqu and N pgu These are the power supply, heat supply, natural gas consumption, and capacity of the internal combustion engine; η e,pgu and η h,loss These are the power generation efficiency and heat loss coefficient of an internal combustion engine, respectively.

[0039] Absorption chiller / hot water system:

[0040] Q h,abs =Q abs η h,abs

[0041] Q c,abs =Q abs η c,abs

[0042] In the formula, Q h,abs Q c,abs and Q abs These are the heating capacity, cooling capacity, and required heat energy of the absorption chiller / thermal water heater; η h,abs and η c,abs These are the heating efficiency and cooling efficiency of the absorption chiller / water heater, respectively.

[0043] Photovoltaics:

[0044]

[0045]

[0046] In the formula, E pv and N pv These represent the power supply and capacity of the photovoltaic system, respectively; f is the power derating factor for the photovoltaic system; G p G represents the actual light intensity. stc Light intensity under standard test conditions; α is the power temperature coefficient; T pv,p T represents the actual photovoltaic surface temperature. pv,stc The photovoltaic surface temperature under standard test conditions; T a,p The ambient temperature; T pv,socThe photovoltaic surface temperature under standard operating conditions; η e,pv τ represents the photovoltaic efficiency under standard test conditions; τ is the solar transmittance, β is the solar absorptivity; standard operating conditions are standard irradiance G. soc and standard ambient temperature T a,soc ;

[0047] Photothermal:

[0048]

[0049] η stc =0.7-2.5(40-T) a,p ) / G p (Winter and transitional seasons) or 0.7-2.5 (70-T) a,p ) / G pp (summer)

[0050] In the formula, Q stc N stc and η stc These are the heat output, capacity, and efficiency of solar thermal energy, respectively.

[0051] Ground source heat pump:

[0052] Q h,hp =θQ h,u

[0053] Q c,hp =θQ c,u

[0054] E hp =Q h,hp / η h,hp Or Q c,hp / η c,hp

[0055] In the formula, Q h,hp and Q c,hp These are the heating and cooling capacities of the ground source heat pump, respectively; Q h,u and Q c,u These represent the user's heat load and cooling load, respectively; θ represents the heating ratio and cooling ratio of the ground source heat pump; E hp This refers to the power consumption of a ground source heat pump; η h,hp and η c,hp These are the heating efficiency and cooling efficiency of the ground source heat pump, respectively.

[0056] Gas-fired boilers:

[0057] Q b =F b η b

[0058] In the formula, Q b Fb and η b These are the heating capacity of the gas-fired boiler, natural gas consumption, and thermal efficiency.

[0059] Storage battery:

[0060]

[0061] 0≤E s,out ≤0.4N s

[0062] 0≤E s,in ≤0.2N s

[0063] In the formula, and These represent the energy storage states of the battery before and after charging / discharging; η s,loss η s,ch η s,disch These represent the battery's self-dissipation rate, charging efficiency, and discharging efficiency, respectively; ξ takes a value of 0 or 1 (0, discharging; 1, charging); E s,out and E s,in These represent the battery's discharge and charge amounts, respectively; N s This refers to the capacity of the battery.

[0064] Water storage tank:

[0065]

[0066]

[0067] In the formula, Q h,wst,in and Q h,wst,out Q c,wst,in and Q c,wst,out The heat storage and heat release, cold storage capacity and cold release capacity of the water storage tank; and and These represent the energy storage states of the water tank before and after heat storage / release and cooling / storage, respectively; η wst The thermal efficiency of the water storage tank;

[0068] b2) Power balance constraints

[0069] Electric power:

[0070] E grid,im +E pv +E pgu +E s,out =E u +E hp +E s,in +e grid,ex

[0071] In the formula, e u For the user's electrical load;

[0072] Thermal power:

[0073] Q h,abs +Q h,hp +Q h,wst,out =Q h,u +Q h,wst,in

[0074] Cooling power:

[0075] Q c,abs +Q c,hp +Q c,wst,out =Q c,u +Q c,wst,in

[0076] The decision variables are as follows:

[0077] Case 1: X = [N] pgu N pv N stc N wst N s ,θ1,θ2]

[0078] Case 2: X = [N] pgu N pv N stc N wst N s ,θ1,θ2…θ9]

[0079] Case 3: X = [N] pgu N pv N stc N wst N s ,θ1,θ2…θ 212 ].

[0080] Compared with existing technologies, this invention explores the optimal operating mode of ground source heat pumps by introducing the heating ratio or cooling ratio of ground source heat pumps at different time scales, so as to optimize the economic, energy and environmental performance of the solar-geothermal-natural gas complementary energy supply system. Attached Figure Description

[0081] Figure 1 Flowchart of existing integrated cooling, heating and power energy optimization system and method;

[0082] Figure 2 A flowchart for the optimization research of existing combined cooling, heating and power systems and their coupling with ground source heat pump systems;

[0083] Figure 3This is a flowchart of the present invention;

[0084] Figure 4 This is a schematic diagram of the application system of the present invention;

[0085] Figure 5 This is a schematic diagram of the load and environmental parameters of the present invention, wherein (a) is the hourly heating and cooling load curve, (b) is the hourly electrical load curve, (c) is the hourly radiation intensity curve, and (d) is the hourly ambient temperature curve.

[0086] Figure 6 The diagram shows the performance of the energy supply system corresponding to different ground source heat pump operation strategies of the present invention, including (a) the relationship curve between annual cost, primary energy consumption and carbon dioxide emissions, (b) the relationship curve between annual cost and primary energy consumption, and (c) the relationship curve between annual cost and carbon dioxide emissions. Detailed Implementation

[0087] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of the present invention.

[0088] like Figure 3 As shown, the present invention provides a method for coordinated scheduling of multi-energy supply systems based on a multi-timescale operation strategy of ground source heat pumps. The method includes the following steps:

[0089] Step 1: Obtain the cooling load, heating load, and electrical load of the building powered by the system;

[0090] Step 2: Construct a complementary energy supply system of solar energy, geothermal energy, and natural gas;

[0091] Step 3: Determine the scheduling strategy for the complementary energy supply system of solar-geothermal-natural gas;

[0092] Step 4: Establish an optimization model for a complementary energy supply system of solar energy, geothermal energy, and natural gas;

[0093] Step 5: Refine the decision variables for the complementary energy supply system of solar-geothermal-natural gas.

[0094] (1) Taking a hotel in Beijing as an example, the hotel has a solar energy utilization area of ​​2000 square meters and operates continuously throughout the year. The hourly cooling, heating, and electrical loads of the hotel are calculated using the building environment simulation analysis software DeST. The environmental parameters and hourly cooling, heating, and electrical loads are as follows: Figure 5As shown in Table 1, the unit capacity investment cost for different generating units is as follows. The prices of natural gas and electricity from the municipal grid are shown in Table 2. The CO2 emission coefficients for natural gas and electricity from the municipal grid are 0.220 and 0.968 kg / kWh, respectively.

[0095] Table 1

[0096] internal combustion engine 985.3 Ground source heat pump 318.8 Absorption chiller / heater 217.4 Storage battery 258.2 Photovoltaics 1450 Water storage tank 33.3 Photothermal 434.7 Gas boiler 40

[0097] Table 2

[0098]

[0099] (2) Construct a complementary energy supply system of solar energy, geothermal energy and natural gas. The energy supply equipment includes: internal combustion engine, absorption chiller, photovoltaic, solar thermal, ground source heat pump, gas boiler, storage battery, water storage tank and municipal power grid; internal combustion engine, photovoltaic, storage battery and municipal power grid can meet the electrical load of users and ground source heat pump; absorption chiller, ground source heat pump and water storage tank can meet the heat load and cooling load of users; the heat source of absorption chiller includes internal combustion engine, solar thermal and gas boiler.

[0100] (3) The dispatching strategy adopts the electric following strategy, and the energy supply system prioritizes the electric load, and then meets the heat load and cold load.

[0101] (4) The optimization model of this energy supply system includes: using annual cost, primary energy consumption, and carbon dioxide emissions as objective functions, equipment output constraints and power balance constraints as constraints, and the capacity of internal combustion engine, photovoltaic, solar thermal, battery, water storage tank, and the heating and cooling ratios of ground source heat pump as decision variables. Specifically, in the first case, the ground source heat pump operation strategy uses quarterly coefficients, i.e., one heating coefficient for the heating season and one cooling coefficient for the cooling season, for a total of two coefficients; in the second case, the ground source heat pump operation strategy uses monthly coefficients, requiring one energy supply coefficient for each month of both the heating and cooling seasons, for a total of nine coefficients; in the third case, the ground source heat pump operation strategy uses daily coefficients, with a total of 212 days in both the heating and cooling seasons, for a total of 212 energy supply coefficients. Then, a multi-objective genetic algorithm and the TOPSIS method are used to solve the model.

[0102] The objective function is as follows:

[0103] 1) Annual cost

[0104]

[0105] In the formula, N m C m and l mThese represent the capacity, unit investment cost, and service life of the m-th device, respectively; r is the discount rate; ε is the maintenance factor; C ng C grid,im and C grid,ex These are the prices of natural gas, electricity purchase, and electricity sales; F pgu and F b These are the natural gas consumption figures for internal combustion engines and gas-fired boilers, respectively; E grid,im and E grid,ex These are the electricity purchased and the electricity sold.

[0106] 2) Primary energy consumption

[0107]

[0108] In the formula, η pp and η grid These are the power efficiency of the power plant and the power grid, respectively.

[0109] 3) Carbon dioxide emissions

[0110]

[0111] In the formula, λ ng and λ grid These are the carbon dioxide emissions from natural gas and municipal power grids, respectively.

[0112] The constraints are as follows:

[0113] 1) Equipment output constraints

[0114] internal combustion engine:

[0115] E pgu =F pgu η e,pgu

[0116] Q pgu =F pgu (1-η e,pgu -η h,loss )

[0117] 0.3N pgu ≤E pgu ≤N pgu

[0118] In the formula, E pgu Q pgu F pgu and N pgu These are the power supply, heat supply, natural gas consumption, and capacity of the internal combustion engine; η e,pgu and η h,loss These are the power generation efficiency and heat loss coefficient of an internal combustion engine, respectively.

[0119] Absorption chiller / hot water system:

[0120] Q h,abs =Q abs η h,abs

[0121] Q c,abs =Q abs η c,abs

[0122] In the formula, Q h,abs Q c,abs and Q abs These are the heating capacity, cooling capacity, and required heat energy of the absorption chiller / thermal water heater; η h,abs and η c,abs These refer to the heating efficiency and cooling efficiency of the absorption chiller / water heater.

[0123] Photovoltaics:

[0124]

[0125]

[0126] In the formula, E pv and N pv These represent the power supply and capacity of the photovoltaic system, respectively; f is the power derating factor for the photovoltaic system; G p G represents the actual light intensity. stc Light intensity under standard test conditions; α is the power temperature coefficient; T pv,p T represents the actual photovoltaic surface temperature. pv,stc The photovoltaic surface temperature under standard test conditions; T a,p The ambient temperature; T pv,soc The photovoltaic surface temperature under standard operating conditions; η e,pv τ represents the photovoltaic efficiency under standard test conditions; τ is the solar transmittance, β is the solar absorptivity; standard operating conditions are standard irradiance G. soc and standard ambient temperature T a,soc .

[0127] Photothermal:

[0128]

[0129] η stc =0.7-2.5(40-T) a,p ) / G p (Winter and transitional seasons) or 0.7-2.5 (70-T) a,p ) / G pp (summer)

[0130] In the formula, Q stc Nstc and η stc These represent the heat output, capacity, and efficiency of solar thermal energy.

[0131] Ground source heat pump:

[0132] Q h,hp =θQ h,u

[0133] Q c,hp =θQ c,u

[0134] E hp =Q h,hp / η h,hp Or Q c,hp / η c,hp

[0135] In the formula, Q h,hp and Q c,hp These are the heating and cooling capacities of the ground source heat pump, respectively; Q h,u and Q c,u These represent the user's heat load and cooling load, respectively; θ represents the heating ratio and cooling ratio of the ground source heat pump; E hp This refers to the power consumption of a ground source heat pump; η h,hp and η c,hp These are the heating efficiency and cooling efficiency of the ground source heat pump, respectively.

[0136] Gas-fired boilers:

[0137] Q b =F b ω b

[0138] In the formula, Q b F b and η b These are the heating capacity of the gas-fired boiler, natural gas consumption, and thermal efficiency.

[0139] Storage battery:

[0140]

[0141] 0≤E s,out ≤0.4N s

[0142] 0≤E s,in ≤0.2N s

[0143] In the formula, and These represent the energy storage states of the battery before and after charging / discharging; η s,loss η s,ch η s,dischThese represent the battery's self-discharge rate, charging efficiency, and discharging efficiency, respectively; ξ takes a value of 0 or 1 (0, discharging; 1, charging). E s,out and E s,in These represent the battery's discharge and charge amounts, respectively; N s This refers to the capacity of the battery.

[0144] Water storage tank:

[0145]

[0146]

[0147] In the formula, Q h,wst,in and Q h,wst,out Q c,wst,in and Q c,wst,out The heat storage and heat release, cold storage capacity and cold release capacity of the water storage tank; and and These represent the energy storage states of the water tank before and after heat storage / release and cooling / storage, respectively; η wst The thermal efficiency of the water storage tank.

[0148] 2) Power balance constraints

[0149] Electric power:

[0150] E grid,im +E pv +E pgu +E s,out =E u +E hp +E s,in +E grid,ex

[0151] In the formula, E u For the user's electrical load.

[0152] Thermal power:

[0153] Q h,abs +Q h,hp +Q h,wst,out =Q h,u +Q h,wst,in

[0154] Cooling power:

[0155] Q c,abs +Q c,hp +Q c,wst,out =Q c,u +Q c,wst,in

[0156] (5) The decision variables are as follows:

[0157] Case 1: X = [N] pgu N pv N stc N wst N s ,θ1,θ2]

[0158] Case 2: X = [N] pgu N pv N stc N wst N s ,θ1,θ2…θ9]

[0159] Case 3: X = [N] pgu N pv N stc N wst N s ,θ1,θ2…θ 212 ]

[0160] (6) The results of the example are shown below:

[0161] After optimization using a multi-objective genetic algorithm, the performance of the energy supply system corresponding to different ground source heat pump operation strategies is as follows: Figure 6 As shown, the ground source heat pump operating at the day coefficient (Case 3) delivers better economic, energy, and environmental benefits. Through polynomial fitting, the energy and environmental performance corresponding to the same economic performance for the three ground source heat pump operating strategies are shown in Table 3. It can be seen that compared to the quarterly and monthly coefficients, the day coefficient saves 190,262 kWh and 140,804 kWh in primary energy consumption, and reduces carbon dioxide emissions by 33,051 kg and 26,356 kg, respectively. The performance and configuration of the energy supply system corresponding to the ground source heat pump operating at the day coefficient (Case 3) after TOPSIS optimization are shown in Tables 4 and 5.

[0162] Table 3

[0163] Case 1 39000 1873775 423992 Case 2 39000 1824317 417297 Case 3 39000 1683513 390941

[0164] Table 4

[0165] Case 3 336810 1785745 413904

[0166] Table 5

[0167] internal combustion engine 174 Ground source heat pump 429 Absorption chiller / heater 1216 Storage battery 1400 Photovoltaics 727 Water storage tank 6202 Photothermal 0 Gas boiler 554

[0168] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any person skilled in the art can easily conceive of various equivalent modifications or substitutions within the technical scope disclosed in the present invention, and these modifications or substitutions should all be covered within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A method for coordinated scheduling of multi-energy supply systems, characterized in that, This method is based on a multi-timescale operation strategy for ground source heat pumps, and specifically includes the following steps: Step 1: Obtain the cooling load, heating load, and electrical load of the building powered by the system; Step 2: Construct a complementary energy supply system of solar energy, geothermal energy, and natural gas; Step 3: Determine the scheduling strategy for the complementary energy supply system of solar-geothermal-natural gas; Step 4: Establish an optimization model for a complementary energy supply system of solar energy, geothermal energy, and natural gas; Step 5: Refine the decision variables for the complementary energy supply system of solar-geothermal-natural gas; In step 3, the scheduling strategy of the solar-geothermal-natural gas complementary energy supply system includes: under the electricity following strategy, the energy supply system prioritizes meeting the electrical load, and then meets the thermal load and cooling load. For electrical load, when the electricity from photovoltaics exceeds the load, the excess is preferentially stored in batteries, and any remaining electricity is sold to the municipal power grid. Conversely, batteries are used to supplement the shortfall. If the electricity provided by photovoltaics and batteries cannot meet the load, the shortfall is supplemented by the internal combustion engine or the municipal power grid. When the shortfall is below the minimum power generation of the internal combustion engine, it is met by the municipal power grid. If the shortfall is above the minimum power generation of the internal combustion engine but below its maximum power generation, it is met by the internal combustion engine. If the shortfall is above the maximum power generation of the internal combustion engine, it is met by both the internal combustion engine and the municipal power grid. For heat load or cooling load, the operation mode of ground source heat pump is improved by introducing heating and cooling ratio coefficients for different time scales of ground source heat pump. Ground source heat pump prioritizes to provide a certain proportion of heat load or cooling load, and the remaining heat load or cooling load is met by absorption chiller and water storage tank. If the heat or cooling provided by the absorption chiller exceeds the remaining heat or cooling load, the excess is preferentially stored in the storage tank, and any remaining heat or cooling is discharged into the environment. Conversely, the storage tank is used to supplement the shortfall in heat or cooling. If the heat or cooling provided by the absorption chiller and storage tank cannot meet the remaining heat or cooling load, the gas boiler provides a certain amount of heat energy to the absorption chiller to increase its heat or cooling output and meet the remaining heat or cooling load.

2. The method for coordinated scheduling of a multi-energy supply system according to claim 1, characterized in that, In step 1, for buildings already in use, the building's cooling load, heating load, and electrical load data are collected. For buildings not in use, the building environment simulation analysis software DeST is used to calculate the building's cooling load, heating load, and electrical load data.

3. The method for coordinated scheduling of a multi-energy supply system according to claim 1, characterized in that, In step 2, the equipment of the solar-geothermal-natural gas complementary energy supply system includes: an internal combustion engine, an absorption chiller / water heater, photovoltaic power, solar thermal power, ground source heat pump, gas boiler, battery, water storage tank, and municipal power grid; wherein the internal combustion engine, photovoltaic power, battery, and municipal power grid can meet the electrical load of the user and the ground source heat pump; the absorption chiller / water heater, ground source heat pump, and water storage tank can meet the user's heat load and cooling load; the heat source of the absorption chiller / water heater includes the internal combustion engine, solar thermal power, and gas boiler.

4. The method for coordinated scheduling of a multi-energy supply system according to claim 1, characterized in that, The proportional coefficients include quarterly coefficients, monthly coefficients, and daily coefficients.

5. The method for coordinated scheduling of a multi-energy supply system according to claim 1, characterized in that, In step 4, the optimization model of the solar-geothermal-natural gas complementary energy supply system includes: using annual cost, primary energy consumption, and carbon dioxide emissions as objective functions, equipment output constraints and power balance constraints as constraints, and the capacity of internal combustion engine, photovoltaic, solar thermal, battery, water tank, and the heating and cooling ratios of ground source heat pump as decision variables; then, a multi-objective genetic algorithm and the TOPSIS method are used to solve the model.

6. The method for coordinated scheduling of a multi-energy supply system according to claim 5, characterized in that, In the first scenario, the ground source heat pump operates using a quarterly coefficient, meaning one heating coefficient is used during the heating season and one cooling coefficient is used during the cooling season, for a total of two coefficients. In the second scenario, the ground source heat pump operates using a monthly coefficient, requiring one energy supply coefficient for each month of both the heating and cooling seasons, for a total of nine coefficients. In the third scenario, the ground source heat pump operates using a daily coefficient, with a total of 212 days in both the heating and cooling seasons, resulting in a total of 212 energy supply coefficients.

7. The method for coordinated scheduling of a multi-energy supply system according to claim 5, characterized in that, The objective function is as follows: a1) Annual cost In the formula, , and They are the first The capacity, unit investment cost, and service life of each piece of equipment; The discount rate; Maintenance factor; , and These are the prices of natural gas, electricity purchase price, and electricity sales price; and These are the natural gas consumption figures for internal combustion engines and gas-fired boilers, respectively. and These are the purchased electricity volume and the sold electricity volume; a2) Primary energy consumption In the formula, and These are the power efficiencies of power plants and power grids, respectively. a3) Carbon dioxide emissions In the formula, and These are the carbon dioxide emissions from natural gas and municipal power grids, respectively. The constraints are as follows: b1) Equipment output constraints internal combustion engine: In the formula, , , and These are the power supply, heat supply, natural gas consumption, and capacity of the internal combustion engine; and These are the power generation efficiency and heat loss coefficient of an internal combustion engine, respectively. Absorption chiller / hot water system: In the formula, , and These are the heating capacity, cooling capacity, and required heat energy of the absorption chiller / thermal water heater. and These are the heating efficiency and cooling efficiency of the absorption chiller / water heater, respectively. Photovoltaics: In the formula, and These refer to the power supply and capacity of the photovoltaic system, respectively. This represents the power derating factor for photovoltaics. This represents the actual light intensity. Light intensity under standard test conditions; The power temperature coefficient; This refers to the actual photovoltaic surface temperature. The photovoltaic surface temperature under standard test conditions; The ambient temperature; The photovoltaic surface temperature under standard operating conditions; Photovoltaic efficiency under standard test conditions; For solar energy transmittance, Solar energy absorption rate; standard operating conditions are based on standard light intensity. and standard ambient temperature ; Photothermal: During winter and the transitional season, Or in summer, ; In the formula, , and These are the heat output, capacity, and efficiency of solar thermal energy, respectively. Ground source heat pump: or In the formula, and These are the heating and cooling capacities of the ground source heat pump, respectively. and These are the user's heat load and cooling load, respectively. For the heating ratio and cooling ratio of a ground source heat pump; This refers to the power consumption of a ground source heat pump; and These are the heating efficiency and cooling efficiency of the ground source heat pump, respectively. Gas-fired boilers: In the formula, , and These are the heating capacity of the gas-fired boiler, natural gas consumption, and thermal efficiency. Storage battery: In the formula, and These represent the energy storage states of the battery before and after charging / discharging. , , These are the battery's self-dissipation rate, charging efficiency, and discharging efficiency, respectively. The value can be 0 or 1, where 0 represents discharging and 1 represents charging. and These represent the battery's discharge and charge amounts, respectively. This refers to the capacity of the battery. Water storage tank: In the formula, and , and The heat storage and heat release, cold storage capacity and cold release capacity of the water storage tank; and , and These represent the energy storage states of the water tank before and after heat storage / release and cooling / storage. The thermal efficiency of the water storage tank; b2) Power balance constraints Electric power: In the formula, For the user's electrical load; Thermal power: Cooling power: The decision variables are as follows: Case 1: Case 2: Case 3: 。

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