A geothermal long-time energy storage based thermal-electric decoupling system and control method

Abstract

The present application relates to the technical field of cogeneration system optimization, in particular to a heat and electricity decoupling system based on geothermal long-time energy storage and a control method. By constructing a low-temperature underground aquifer energy storage unit (ATES), combined with an electric heat pump unit (EHP) to recover the waste heat of a cogeneration unit (CHP), the CHP is deeply decoupled from heat and electricity through collaborative operation. Through intelligent scheduling strategy, the heat supply ratio is dynamically allocated, the power generation adjustment range of the cogeneration unit (CHP) is improved, the wind power consumption capacity is improved, the wind power curtailment rate is reduced, and it is suitable for centralized heating scenarios with high wind power penetration rate.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of combined heat and power system optimization, and particularly relates to a heat and power decoupling system based on geothermal long-term energy storage and a control method. BACKGROUND

[0002] With the rapid growth of global wind power installed capacity, the problem of wind power consumption is increasingly prominent. In the "three north" region of China, due to the heat and power coupling characteristics of combined heat and power (CHP) units, the curtailment rate of electricity during the heating period increases significantly. The traditional heat and power decoupling technology has the following main limitations:

[0003] Firstly, there is a bottleneck in thermal storage technology. Traditional sensible heat storage mainly relies on water tanks, which have limited storage capacity (usually less than 25000 cubic meters) and can only meet the daily peak shaving demand, making it difficult to cope with the fluctuation of wind power output across days. In addition, the matching of storage temperature and regional heating system is poor, which requires additional heat exchange links, resulting in significant energy efficiency loss.

[0004] Secondly, the energy efficiency of electric heat pump (EHP) is insufficient. Existing EHP systems mostly use ambient air as a low-temperature heat source, which limits the evaporation temperature and results in a low coefficient of performance (COP), limiting the ability to consume wind power. At the same time, the coordination mechanism of EHP and the storage system is not perfect, and the advantages of long-term energy storage cannot be fully utilized.

[0005] Thirdly, the dispatching strategy is relatively extensive. The current dispatching strategy is mainly based on historical data and experience rules, lacking precise prediction and real-time response ability to wind power fluctuations. In addition, these strategies do not fully consider the dynamic characteristics of the storage system (such as heat diffusion loss, changes in charging and discharging efficiency), resulting in unsatisfactory peak shaving effect.

[0006] In summary, the existing technology lacks a heat and power decoupling method that takes into account long-term energy storage, low-temperature heat source matching, and intelligent dispatching, making it difficult to achieve "storage-heat exchange-peak shaving" synergistic optimization in the case of large-scale wind power access. SUMMARY

[0007] The purpose of the present application is to provide a heat and power decoupling system based on geothermal long-term energy storage and a control method, which realizes deep heat and power decoupling of combined heat and power (CHP) system through the coordinated operation of the underground aquifer energy storage system (ATES) and the electric heat pump (EHP), thereby reducing wind power curtailment and improving the operating energy efficiency of combined heat and power (CHP).

[0008] To achieve the above purpose, the present application provides the following technical solutions:

[0009] A geothermal long-time energy storage based thermal power decoupling system, comprising: a geothermal aquifer energy storage unit, a plate heat exchanger, an electric heat pump unit, a combined heat and power unit, an electric grid and a heat grid, wherein,

[0010] The geothermal aquifer energy storage unit is connected with the plate heat exchanger, the plate heat exchanger is connected with the combined heat and power unit, the electric heat pump unit, the geothermal aquifer energy storage unit and the heat grid, the electric heat pump unit is connected with the plate heat exchanger, the electric grid and the combined heat and power unit, and the combined heat and power unit is connected with the electric heat pump unit, the plate heat exchanger, the electric grid and the heat grid.

[0011] The geothermal long-time energy storage based thermal power decoupling system as described above, further comprising:

[0012] The geothermal aquifer energy storage unit is used to provide a heat storage space by using a geothermal aquifer and release heat when the heat grid is peak-regulated;

[0013] The plate heat exchanger is used to exchange heat with the combined heat and power unit or the electric heat pump unit, store heat to the geothermal aquifer energy storage unit, provide peak-regulated heat to the heat grid, and reduce power generation and increase heat supply by reducing power generation of the combined heat and power unit;

[0014] The electric heat pump unit is used to recover waste heat of condensate water of the combined heat and power unit, store heat to the geothermal aquifer energy storage unit through the plate heat exchanger, and convert electric energy to heat energy by consuming abandoned wind power or peak power of the combined heat and power unit in the electric grid;

[0015] The combined heat and power unit is used to supply power to the electric grid and supply heat to the heat grid, and provide heat storage to the geothermal aquifer energy storage unit by exchanging heat with the plate heat exchanger.

[0016] A geothermal long-time energy storage based thermal power decoupling control method, applicable to the thermal power decoupling system as described above, comprising the steps of:

[0017] Step 1: constructing an optimization model of the geothermal aquifer energy storage unit, using the optimization model to determine heat storage capacity and optimize well spacing;

[0018] Step 2: collecting data in real time and preprocessing the data;

[0019] Step 3: using part of the data to assess abandoned wind power risk;

[0020] Step 4: using results of the abandoned wind power risk assessment and part of the data to establish a predictive control model;

[0021] Step 5: using the predictive control model to realize coordinated operation of thermal power decoupling.

[0022] The geothermal long-time energy storage-based thermal-electric decoupling control method as described above, further, the step 1 comprises:

[0023] Exploring the underground aquifer, arranging the wells, designing the underground aquifer energy storage unit heat storage capacity;

[0024] Establishing an aquifer temperature field model, optimizing the well spacing to reduce heat diffusion loss.

[0025] The geothermal long-time energy storage-based thermal-electric decoupling control method as described above, further, the step 2 comprises:

[0026] Collecting data: wind power prediction power sequence, electrical load sequence, thermal load sequence, underground aquifer energy storage unit heat storage temperature, combined heat and power unit state;

[0027] Preprocessing the data: correcting wind power prediction error, establishing temperature-heat storage conversion relationship.

[0028] The geothermal long-time energy storage-based thermal-electric decoupling control method as described above, further, the step 3 comprises:

[0029] Combined with predicted wind power, grid available wind power space, base load power generation, establish a wind curtailment risk assessment model.

[0030] The geothermal long-time energy storage-based thermal-electric decoupling control method as described above, further, the step 4 comprises:

[0031] Considering the operation cost of combined heat and power units, the operation cost of electric heat pump units, the wind curtailment penalty cost, carbon emissions, carbon emission weight factor, wind curtailment penalty coefficient; establish a minimum system total cost and carbon emission objective function;

[0032] Considering power balance, equipment operation, underground aquifer energy storage unit heat storage, scheduling priority logic, establishing a multi-layer constraint model;

[0033] Solving by quadratic programming algorithm, dynamically allocating the heat supply proportion of underground aquifer energy storage unit, electric heat pump unit and combined heat and power unit.

[0034] The geothermal long-time energy storage-based thermal-electric decoupling control method as described above, further, the step 5 comprises:

[0035] 1) Heat storage stage, i.e. low wind / high electrical load period:

[0036] ① When wind power output ≤ load demand and combined heat and power unit power generation is abundant, the combined heat and power unit extracts steam for heating, and part of the heat is stored in the underground aquifer energy storage unit through the heat exchanger;

[0037] ②At the same time, the electric heat pump unit takes the low-temperature water in the underground aquifer energy storage unit as a heat medium, recovers the waste heat of the condenser water of the cogeneration unit, consumes surplus electricity, and reduces forced power generation of the cogeneration unit.

[0038] 2) Exothermic phase, i.e. high wind / low electricity load period:

[0039] ① When the wind power output > load demand and the power grid needs to be regulated, the underground aquifer energy storage unit releases hot water to the heat supply network return water side to replace part of the heat supply of the cogeneration unit, reduces the steam extraction amount of the cogeneration unit, and reduces the power generation output of the cogeneration unit;

[0040] ② The electric heat pump unit preferentially consumes abandoned wind power, takes the water in the underground aquifer energy storage unit as a heat source to improve heat supply, and further releases power generation space.

[0041] Compared with the prior art, the present application has the following beneficial effects:

[0042] 1) Enhanced thermal-electric decoupling: by combining the long-term heat storage of ATES (cross-day peak regulation) with the instant decoupling of EHP, the adjustment range of CHP power generation is expanded, thereby improving the accommodation capacity of wind power;

[0043] 2) Improved energy efficiency: the recovery of low-temperature condensing heat of CHP can improve the COP (coefficient of performance) of EHP, while reducing the energy consumption of CHP, thereby improving the overall energy saving rate of the system;

[0044] 3) Optimized cost: the use of underground heat storage can reduce the land occupation of surface facilities, effectively reduce the life cycle cost, and reduce the heat loss rate. BRIEF DESCRIPTION OF DRAWINGS

[0045] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings needed in the embodiments will be briefly introduced as follows. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can also be obtained by those skilled in the art without creative labor.

[0046] Figure 1 The structure diagram of the thermal-electric decoupling system based on geothermal long-time energy storage in the embodiments of the present application;

[0047] Figure 2 The flowchart of the thermal-electric decoupling control method based on geothermal long-time energy storage in the embodiments of the present application;

[0048] Figure 3 The simulation result diagram of the system and the control method in the embodiments of the present application.

[0049] In the drawings: 1, underground aquifer energy storage unit; 2, plate heat exchanger; 3, electric heat pump unit; 4, combined heat and power unit; 5, power grid; 6, heat grid. DETAILED DESCRIPTION

[0050] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only some of the embodiments of the present application, but not all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative work fall within the scope of the present application.

[0051] Embodiment:

[0052] It should be noted that the terms "first", "second" and the like in the description and claims of the present application and the above drawings are used to distinguish similar objects, and do not necessarily indicate a specific order or sequence. It should be understood that the data thus used can be interchanged under appropriate circumstances, so that the embodiments of the application described herein can be implemented in other than the order illustrated or described herein. In addition, the terms "comprise" and "have" and any variations thereof in the embodiments of the present application are intended to cover non-exclusive inclusion, for example, a process, method, system, product or device that includes a series of steps or units does not have to include those steps or units clearly listed, but can include other steps or units not clearly listed

[0053] In the description of the present application, the meaning of "a plurality of" is at least two, for example, two, three, etc., unless otherwise explicitly specified. In addition, unless otherwise explicitly specified and limited, the terms "mount", "connect", "connect" should be understood broadly, for example, it can be fixedly connected, or it can be detachably connected, or integrally connected; it can be mechanically connected, or it can be electrically connected; it can be directly connected, or it can be indirectly connected through an intermediate medium, or it can be the communication inside two elements. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0054] Figure 1 The structural schematic diagram of the geothermal long-time energy storage-based thermal-electric decoupling system in the embodiments of the present application is shown in the figure Figure 1As shown, the embodiment of the present application provides a heat-electricity decoupling system based on geothermal long-time energy storage, comprising: an underground aquifer energy storage unit 1, a plate heat exchanger 2, an electric heat pump unit 3, a combined heat and power unit 4, a power grid 5 and a heat grid 6, wherein the underground aquifer energy storage unit is connected with the plate heat exchanger, the plate heat exchanger is connected with the combined heat and power unit, the electric heat pump unit, the underground aquifer energy storage unit and the heat grid, the electric heat pump unit is connected with the plate heat exchanger, the power grid and the combined heat and power unit, and the combined heat and power unit is connected with the electric heat pump unit, the plate heat exchanger, the power grid and the heat grid.

[0055] In an embodiment, the underground aquifer energy storage unit is used to provide a heat storage space by using an underground aquifer and release heat when the heat grid needs to be adjusted; the plate heat exchanger is used to exchange heat with the combined heat and power unit or the electric heat pump unit, store heat to the underground aquifer energy storage unit, provide peak-shaving heat to the heat grid, and reduce power generation and increase heat supply by reducing the power generation of the combined heat and power unit; the electric heat pump unit is used to recover waste heat of condensate water of the combined heat and power unit, store heat to the underground aquifer energy storage unit through the plate heat exchanger, and convert electric energy to heat energy by consuming abandoned wind power or peak power of the combined heat and power unit; and the combined heat and power unit is used to supply power to the power grid and heat to the heat grid, and provide heat storage to the underground aquifer energy storage unit by exchanging heat with the plate heat exchanger.

[0056] The system is described as a whole below:

[0057] Underground aquifer energy storage unit (ATES): connected with the plate heat exchanger (HEX), used to provide a heat storage space by using an underground aquifer and release heat when the heat grid needs to be adjusted. Specifically, the underground aquifer energy storage unit: provides a large-capacity underground heat storage space, meets the cross-day heat storage demand, releases heat when the heat grid needs to be adjusted, and guarantees the stability and continuity of heat supply.

[0058] Plate heat exchanger (HEX): connected with the combined heat and power unit (CHP), the electric heat pump unit (EHP), the underground aquifer energy storage unit (ATES) and the heat grid (HG), used to exchange heat with the CHP or the EHP, store heat to the ATES, provide peak-shaving heat to the heat grid (HG), and reduce power generation and increase heat supply by reducing the power generation of the combined heat and power unit (CHP). Specifically, the plate heat exchanger: exchanges heat among the combined heat and power unit (CHP), the electric heat pump unit (EHP) and the underground aquifer energy storage unit (ATES), realizes heat storage and release, and adjusts the power generation of the combined heat and power unit (CHP) to realize reverse operation of heat-electricity decoupling.

[0059] Electric heat pump unit (EHP): connected with plate heat exchanger (HEX), power grid (PG) and combined heat and power unit (CHP), used for recovering waste heat of condensate water of combined heat and power unit (CHP), storing heat in underground aquifer energy storage unit (ATES) through plate heat exchanger (HEX), consuming abandoned wind power or peak power of combined heat and power unit (CHP) to convert electric energy into heat energy. Specifically, electric heat pump unit recovers waste heat of condensate water generated by combined heat and power unit, improves energy utilization efficiency, stores heat by using abandoned wind power or peak power of CHP, and enhances the accommodation capacity of renewable energy.

[0060] Combined heat and power unit (CHP): connected with electric heat pump unit (EHP), plate heat exchanger (HEX), power grid (PG) and heat grid (HG), used for simultaneously supplying power to power grid (PG) and supplying heat to heat grid (HG), and providing heat storage for underground aquifer energy storage unit (ATES) through heat exchange with plate heat exchanger (HEX). Specifically, combined heat and power unit simultaneously provides electric power and heat, reasonably allocates energy through heat exchange with plate heat exchanger, and supports heat storage of underground aquifer energy storage unit (ATES).

[0061] Power grid (PG): connected with electric heat pump unit (EHP) and combined heat and power unit (CHP), used for transmission and distribution of electric power.

[0062] Heat grid (HG): connected with plate heat exchanger (HEX), combined heat and power unit (CHP) and underground aquifer energy storage unit (ATES), used for transmission and supply of heat.

[0063] Figure 2 A flowchart of the heat and electricity decoupling control method based on geothermal long-time energy storage in the embodiment of the present application; Figure 3 A simulation result diagram of the system and control method in the embodiment of the present application is shown in FIGS. Figure 2 、 3 The embodiment of the present application provides a heat and electricity decoupling control method based on geothermal long-time energy storage, which is suitable for the heat and electricity decoupling system described above, and includes the following steps:

[0064] Step 1: An optimization model of underground aquifer energy storage unit is constructed, and the optimization model is used to determine the heat storage capacity and optimize the well spacing.

[0065] 1) Exploring underground aquifer, arranging a pair of wells (injection well / production well), and designing ATES heat storage capacity

[0066] ① Geological exploration process: determining the depth (200-500 m), thickness (≥30 m) and permeability (10 -5 ~10 -4m / s); pumping test to determine the hydraulic conductivity (≥1000 m 2 / d), the storage coefficient (0.01-0.05); geothermal gradient test (2.5-3 °C / 100 m) to determine the initial heat storage temperature (25-35 °C).

[0067] ②ATES well group design: 5 pairs of injection wells-production wells, well spacing 200 m, well depth 350 m, single well flow rate 500 m 3 / h; casing configuration: double casing (inner tube Φ273 mm, outer tube Φ325 mm), insulation layer uses polyurethane foam, thermal conductivity ≤0.02 W / (m·K); heat storage capacity is 7.14×1012J, calculated as follows:

[0068] Q s = ρcnVΔTη s

[0069] Wherein, Q s is the heat storage capacity, J; ρ is the density of water, kg / m 3 ; c is the specific heat capacity of water, J / (kg·K); n is the number of well pairs; V is the single well influence volume, m 3 ; ΔT is the heat storage temperature difference, K; η s is the heat storage efficiency.

[0070] 2) Establishing the aquifer temperature field model, through well group spacing optimization, reducing heat diffusion loss

[0071] ① Heat conduction model

[0072]

[0073] Wherein, T is temperature, K; α is thermal diffusivity, m 2 / s; v is water flow velocity, m / s; q is heat source term, W / m 3 .

[0074] ② Well group spacing optimization

[0075] Using the heat conduction model, simulating heat diffusion loss under different well spacing: when the spacing is 200 m, the heat loss rate is 12% / month; the heat loss rate decreases by 3% for every 50 m increase in spacing, but the drilling cost increases by 15%. The optimal well spacing is 200 m, balancing heat loss and investment cost.

[0076]

[0077] Wherein, L a is the heat diffusion loss rate, % / day; k is the thermal conductivity, W / (m·K); A is the heat exchange area, m 2 ; V is the heat storage volume, m 3; ΔT m is the average temperature difference, K. By optimizing the well spacing (200 m), the heat diffusion loss rate is <0.1% / day.

[0078] ③ Temperature field monitoring

[0079] Distributed optical fiber temperature measurement (DTS): temperature measurement points are arranged every 2 m along the well depth, temperature measurement accuracy ±0.1°C; data acquisition frequency: 5 minutes / time, real-time feedback of temperature field changes.

[0080] S2. Real-time data acquisition and preprocessing of the data

[0081] 1) Acquisition parameters

[0082] Acquisition parameters: wind power prediction power sequence: Prediction step t = 1, 2, …, T; Electrical load sequence: P load (t); Thermal load sequence: Q load (t); ATES heat storage temperature: T high (t) (high-temperature reservoir), T low (t) (low-temperature reservoir); CHP unit state: power generation power P chp (t), heat supply power Q chp (t); EHP state: electric power P ehp (t), heat supply power Q ehp (t).

[0083] 2) Data preprocessing

[0084] Wind power prediction error correction:

[0085] wherein, is the historical prediction error mean, is the current prediction error, and ε is the forgetting factor.

[0086] Temperature-heat storage conversion: H ates (t) = ρcV(T(t) - T ref )

[0087] wherein, ρ is the water density, cwateris the specific heat capacity, V is the reservoir volume, T ref is the reference temperature.

[0088] S3. Abandoned wind power risk assessment using part of the data.

[0089] Combined with predicted wind power, grid available wind power space, and base load power generation, an abandoned wind power risk assessment model is established.

[0090]

[0091] P space (t)=P load -P base

[0092] where, is the predicted wind power, P space (t) is the grid available wind power space, P base is the base load generation power.

[0093] S4. Establish a predictive control model using the results of the wind curtailment risk assessment and some of the data.

[0094] 1) Consider the CHP operating cost, EHP operating cost, wind curtailment penalty cost, carbon emissions, carbon emission weight factor, wind curtailment penalty coefficient; Establish a total system cost and carbon emission objective function to minimize.

[0095]

[0096] where, C chp (t) is the CHP operating cost; C ehp (t) is the EHP operating cost; C pena (t) is the wind curtailment penalty cost; E co2 (t) is the carbon emissions; λ is the carbon emission weight factor; β is the wind curtailment penalty coefficient.

[0097] 2) Consider power balance, equipment operation, ATES heat storage, scheduling priority logic, etc. to establish a multi-layer constraint model.

[0098] ① Power balance constraint

[0099]

[0100] ② Equipment operation constraint

[0101]

[0102] ③ ATES heat storage constraint

[0103]

[0104] where, η char is the heat storage efficiency, η disch is the heat release efficiency, Δt is the time step.

[0105] ④ Scheduling priority logic constraint

[0106] When the wind curtailment risk R(t) > R h :

[0107]

[0108] wherein γ is a peak regulation factor.

[0109] When and :

[0110]

[0111] 3) Solving by quadratic programming (QP) algorithm, dynamically allocating the heating proportion of CHP, ATES, and EHP.

[0112] S5. Realizing heat and electricity decoupling collaborative operation by using a predictive control model.

[0113] 1) Heat storage stage (low wind / high electricity load period)

[0114] ① CHP steam extraction and ATES heat storage

[0115] Energy flow control:

[0116]

[0117] wherein, is the total heating capacity of CHP, is the heat load demand, η hx is the heat exchanger efficiency.

[0118] Control logic: when and , start steam extraction; the extraction amount is controlled by a regulating valve to ensure that the ATES heat storage power is ≤ 150 MW.

[0119] ② EHP waste heat recovery and electricity consumption

[0120] EHP operating parameters: heat medium temperature: ATES low-temperature water (25-30℃); heat network return water temperature: 50℃;

[0121]

[0122] wherein, α is an efficiency factor; T c is the condensation temperature, ℃; T e is the evaporation temperature, ℃.

[0123] Waste heat recovery amount: Q wast = mc(T c -T r ); wherein, T r is the return water temperature, ℃.

[0124] Electricity consumption: P ehp = Q hp / COP; wherein, Q hp is the heating power, W; Php W is the electrical power.

[0125] This part of the power consumption reduces the CHP forced power generation, realizing the heat and power decoupling.

[0126] 2) Exothermic phase (high wind / low electrical load period)

[0127] ①ATES exothermic and CHP peak shaving

[0128] Heat network temperature control:

[0129]

[0130] Where, T ates is the ATES water temperature, ℃; T chp is the CHP steam temperature, ℃.

[0131] H a (t) = H a (t-1) + η s Q s (t)Δt-Q r (t)Δt

[0132] Where, H a (t) is the heat storage at time t, J; η s is the heat storage efficiency; Q s , Q r are the heat storage and exothermic power, W; Δt is the time step, s.

[0133] Power generation space release:

[0134]

[0135] CHP power generation efficiency and the ATES exothermic power is , the power generation space ΔP chp ≈ 333 kW can be released.

[0136] P chp = P0-c v Q chp

[0137] Where, P chp is the actual CHP power generation, W; P0 is the maximum CHP power generation, W; c v is the power generation power reduction coefficient; Q chp is the maximum CHP heat supply power, W.

[0138] ②EHP wind curtailment consumption and heat supply enhancement

[0139] Wind power utilization:

[0140] Heat increment:

[0141] It should be understood that the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate relative or positional relationships based on the orientation or position shown in the drawings, and are used only to facilitate the description of the present application and simplify the description, and do not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the present application.

[0142] In the present application, unless otherwise explicitly specified and limited, the first feature is "on" or "under" the second feature, which can be direct contact between the first and second features, or indirect contact through an intermediate medium. Moreover, the first feature "above", "above" and "above" the second feature can be directly above or obliquely above the first feature, or only indicate that the horizontal height of the first feature is higher than that of the second feature. The first feature "below", "below" and "below" the second feature can be directly below or obliquely below the first feature, or only indicate that the horizontal height of the first feature is less than that of the second feature.

[0143] In the description of the present application, the description of the terms "one embodiment", "some embodiments", "example", "specific example" or "some examples" and the like means that the specific features, structures, materials or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present application. In the present application, the illustrative description of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any appropriate manner in any one or more embodiments or examples. In addition, different embodiments or examples described in the present application and the features of different embodiments or examples can be combined and combined by those skilled in the art without contradiction.

[0144] The above embodiments are only for the purpose of illustrating the technical concept and characteristics of the present application, and the purpose is to enable those skilled in the art to understand the content of the present application and to implement it, and cannot limit the protection scope of the present application. Any equivalent changes or modifications made in accordance with the essence of the present application should be covered within the protection scope of the present application.

Claims

1. A geothermal long-time energy storage-based thermal-electric decoupling control method, characterized in that, The application relates to a geothermal long-time energy storage-based heat and power decoupling system, which comprises an underground aquifer energy storage unit, a plate heat exchanger, an electric heat pump unit, a combined heat and power unit, an electric network and a heat network, wherein, the underground aquifer energy storage unit is connected with the plate heat exchanger, the plate heat exchanger is connected with the combined heat and power unit, the electric heat pump unit, the underground aquifer energy storage unit and the heat network, the electric heat pump unit is connected with the plate heat exchanger, the electric network and the combined heat and power unit, and the combined heat and power unit is connected with the electric heat pump unit, the plate heat exchanger, the electric network and the heat network; the method comprises the following steps: Step 1: constructing an optimization model of the underground aquifer energy storage unit, and determining the heat storage capacity and optimizing the well spacing by using the optimization model, wherein the underground aquifer is explored, a pair of wells is arranged, and the heat storage capacity of the underground aquifer energy storage unit is designed; a temperature field model of the aquifer is established, and the heat diffusion loss is reduced through well spacing optimization; Step 2: collecting data in real time and preprocessing the data, wherein the data collected include a wind power prediction power sequence, an electric load sequence, a heat load sequence, the heat storage temperature of the underground aquifer energy storage unit and the state of the combined heat and power unit; the data are preprocessed by correcting the wind power prediction error and establishing a temperature-heat storage quantity conversion relationship; Step 3: using part of the data to evaluate the risk of abandoned wind power, wherein a risk evaluation model of abandoned wind power is established by combining the predicted wind power, the space of the electric network that can accommodate wind power, and the base load power generation power; Step 4: using the results of the risk evaluation of abandoned wind power and part of the data to establish a predictive control model, wherein the operation cost of the combined heat and power unit, the operation cost of the electric heat pump unit, the abandoned wind power penalty cost, carbon emission, carbon emission weight factor and abandoned wind power penalty coefficient are considered; a minimum system total cost and carbon emission objective function is established; a multi-layer constraint model is established by considering power balance, equipment operation, underground aquifer energy storage unit heat storage and dispatching priority logic; the heat supply proportion of the underground aquifer energy storage unit, the electric heat pump unit and the combined heat and power unit is dynamically allocated by using a quadratic programming algorithm; Step 5: using the predictive control model to realize the collaborative operation of heat and power decoupling.

2. The heat and power decoupling control method based on geothermal long-time energy storage according to claim 1, wherein the underground aquifer energy storage unit is used to provide a heat storage space by using the underground aquifer and release heat when the heat network is peak-regulated; the plate heat exchanger is used to exchange heat with the combined heat and power unit or the electric heat pump unit, store heat to the underground aquifer energy storage unit, provide peak-regulated heat to the heat network, reduce power generation and increase heat supply by reducing the power generation power of the combined heat and power unit, and realize heat and power decoupling; the electric heat pump unit is used to recover the condensate water waste heat of the combined heat and power unit, store heat to the underground aquifer energy storage unit through the plate heat exchanger, consume the abandoned wind power in the electric network or the peak surplus power of the combined heat and power unit, convert electric energy into heat energy, enhance the heat storage capacity of the system, and realize deep heat and power decoupling. The cogeneration unit is used for supplying power to the power grid and supplying heat to the heat network, and heat exchange with the plate heat exchanger provides heat storage for the underground aquifer energy storage unit.

3. The geothermal-based long-time energy storage thermoelectric decoupling control method according to claim 1, characterized in that, The step 5 comprises: 1) heat storage stage, i.e. low wind / high electricity load period: ① when the wind power output is less than the load demand and the cogeneration unit has excess power generation, the cogeneration unit extracts steam for heat supply, and part of the heat is stored in the underground aquifer energy storage unit through the heat exchanger; ② at the same time, the electric heat pump unit takes the low-temperature water in the underground aquifer energy storage unit as the heat medium, recovers the waste heat of the condensate water of the cogeneration unit, consumes the excess power, and reduces the forced power generation of the cogeneration unit; 2) heat release stage, i.e. high wind / low electricity load period: ① when the wind power output is greater than the load demand and the power grid needs to be adjusted, the underground aquifer energy storage unit releases hot water to the return water side of the heat network to replace part of the heat supply of the cogeneration unit, reduces the steam extraction amount of the cogeneration unit, and reduces the power generation output of the cogeneration unit; ② the electric heat pump unit preferentially consumes the abandoned wind power, takes the water in the underground aquifer energy storage unit as the heat source to improve the heat supply, and further releases the power generation space.

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