Carbon neutral energy supply system and method with pumped storage power station and geothermal energy cascade utilization

Abstract

The application provides a carbon neutral energy supply system and method for pumped storage power station and geothermal energy cascade utilization, comprising: a geothermal grading power generation unit, a pumped storage unit, a waste heat-potential energy coupling unit, a carbon cycle management unit and an intelligent collaborative regulation unit; the geothermal grading power generation unit comprises a high-temperature geothermal well, a medium-low temperature geothermal well and a two-stage flash evaporation generator set, high-temperature geothermal steam drives a first-stage steam turbine to generate power, and the remaining steam is mixed with medium-low temperature fluid to drive a second-stage steam turbine to generate power. Through the three-in-one architecture of'multi-energy cascade utilization-carbon closed loop management-intelligent dynamic optimization', the application solves the industry problems of traditional pumped storage power station, such as dependence on high-carbon power, low utilization rate of geothermal resources and insufficient system flexibility, and realizes four breakthroughs of 'energy efficiency, low-carbon operation, intelligent management and control and diversified benefits', thereby providing a carbon neutral solution that can be replicated and popularized for building a new power system.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of pumped storage and carbon neutralization, and in particular to a carbon neutralization energy supply system and method for pumped storage power station and geothermal energy cascade utilization. BACKGROUND

[0002] Although the existing pumped storage power station is widely used in grid peak shaving, its energy conversion efficiency is low, and the pumping stage relies on high-carbon grid power, indirectly increasing carbon emissions. The utilization of geothermal energy is limited by low efficiency of low-temperature resource power generation, waste heat of tail water not being recovered, and emission of associated greenhouse gases, resulting in energy waste and increased carbon footprint. Both of them are difficult to meet the demand of carbon neutralization target when running independently.

[0003] The existing joint technology attempts to simply couple pumped storage and geothermal energy, such as using geothermal power generation surplus power to drive the water pump, but does not build a heat energy-electricity-potential energy cascade utilization chain, and the waste heat of geothermal tail water is still abandoned, and the comprehensive energy efficiency is improved by less than 5%. At the same time, the system lacks dynamic regulation and control capability, and cannot respond to changes in grid and geothermal parameters, and does not solve the carbon emission closed loop problem of geothermal development, and the whole life cycle carbon intensity is still over standard.

[0004] The core problem of the traditional scheme is the lack of energy utilization fault and carbon management: the traditional scheme fails to realize the integration of multi-energy complementary optimization and negative carbon technology, resulting in low resource utilization and poor economy. SUMMARY

[0005] In view of the defects of the prior art, the present application provides a carbon neutralization energy supply system and method for pumped storage power station and geothermal energy cascade utilization, which can effectively solve the above problems.

[0006] The technical scheme adopted by the present application is as follows:

[0007] The present application provides a carbon neutralization energy supply system for pumped storage power station and geothermal energy cascade utilization, comprising: a geothermal grading power generation unit, a pumped storage unit, a waste heat-potential energy coupling unit, a carbon cycle management unit and an intelligent collaborative regulation and control unit;

[0008] The geothermal grading power generation unit comprises a high-temperature geothermal well, a medium-low temperature geothermal well and a two-stage flash steam turbine generator set; the two-stage flash steam turbine generator set comprises a primary steam turbine and a secondary steam turbine; the high-temperature geothermal steam of the high-temperature geothermal well drives the primary steam turbine to generate electricity, and the remaining high-temperature geothermal steam of the high-temperature geothermal well and the medium-low temperature fluid of the medium-low temperature geothermal well are mixed to drive the secondary steam turbine to generate electricity;

[0009] The pumped storage unit comprises a reversible pump turbine, an upper reservoir and a lower reservoir; the reversible pump turbine uses the geothermal power surplus and the grid surplus power of the geothermal grading power generation unit to pump and store water during the low load period of the power grid, and generates power by releasing water from the upper reservoir to the lower reservoir during the peak period;

[0010] The waste heat-potential energy coupling unit comprises a waste heat recovery heat exchanger, an ORC generator set and a phase change heat storage tank; based on the waste heat recovery heat exchanger, the ORC generator set uses the waste heat of the geothermal tail water of the geothermal grading power generation unit to generate power, the generated waste heat is stored in the phase change heat storage tank, and the heat pump provides anti-freezing preheating for the pumping and storing pipeline of the pumped storage unit;

[0011] The carbon cycle management unit comprises a geothermal fluid CO2 separation device, a mineralization storage well and a carbon sink monitoring terminal; the geothermal fluid CO2 separation device uses an amine-membrane separation composite process to capture the geothermal tail gas of the geothermal grading power generation unit, separates out CO2, and uses the mineralization storage well to inject the separated CO2 into the basalt layer for mineralization under the water pressure of the lower reservoir of the pumped storage unit; the carbon sink monitoring terminal is used for carbon sink monitoring of the geothermal tail gas treated by the geothermal fluid CO2 separation device;

[0012] The intelligent collaborative regulation unit is deployed on an edge computing node and comprises a prediction layer, an optimization layer and a control layer; the prediction layer is used for predicting the future 12-hour power grid load and the geothermal output of the geothermal grading power generation unit; the optimization layer is used for establishing a target function of maximum benefit and minimum carbon emission intensity; and the control layer is used for dynamically allocating the power of the pumped storage unit and the carbon capture energy consumption weight of the carbon cycle management unit according to the prediction result of the prediction layer and taking the target function of the optimization layer as the target, so that the system comprehensive energy efficiency and the whole life cycle carbon emission intensity meet the set target.

[0013] Preferably, the CO2 mineralization reaction rate in the carbon cycle management unit is calculated in real time, and the value is related to the reaction constant, the activation energy, the temperature, the applied pressure of the lower reservoir and the fracture surface area of the rock layer.

[0014] Preferably, in the waste heat-potential energy coupling unit, the heat energy release rate of the phase change heat storage tank satisfies:

[0015]

[0016] wherein: T 储热The time constant of the heat storage material is reduced by 60% by optimizing the value of U*A; U: heat transfer coefficient, indicating the heat transfer efficiency between the phase change heat storage tank and the pumped storage pipeline, the larger the value, the stronger the heat transfer capacity; A: heat transfer area, which is the effective heat transfer area of the phase change heat storage tank and the pumped storage pipeline; Tpipeline: real-time temperature of the pumped storage pipeline wall, which is the outer wall temperature of the pumped storage pipeline that needs to be preheated to prevent freezing, monitored by a temperature sensor; t is the time variable.

[0017] Preferably, the prediction layer predicts the future 12-hour power grid load and the geothermal output of the geothermal grading power generation unit using an LSTM-Attention neural network, and the hidden state update formula is:

[0018] h t =LSTM(x t ,h t-1 ),α t =softmax(W a [h t ;H history ]);

[0019] Where: h t : hidden state at time t; h t-1 : hidden state at time t-1; x t is the input vector at time t; H history is the historical load sequence encoding vector; W a is the attention weight matrix; α t is the attention weight at time t.

[0020] Preferably, the multi-objective function F constructed by the optimization layer is:

[0021] F=λ1f 收益 +λ2f 碳强度

[0022]

[0023] Where: λ1 is the weight coefficient of the revenue target; λ2 is the weight coefficient of the carbon intensity target; f 收益 is the revenue function, representing the economic revenue target of the system; f 碳强度 is the carbon intensity function, representing the carbon emission intensity target of the system; t is the time; T is the period; P 售电 (t) is the electricity price at time t; E 发电 (t) is the power generation of the pumped storage unit at time t; C 抽蓄 (t) is the pumped storage cost of the pumped storage unit at time t; Q CO2 is the CO2 storage capacity of the carbon cycle management unit; P 碳价The transaction price per unit of carbon; E 地热 (t) is the geothermal power generation of the geothermal grading power generation unit at time t; μ 地热 is the carbon emission coefficient of the geothermal grading power generation unit, which is the theoretical value of the carbon emission per unit of geothermal power generation; E 电网 (t) is the electrical energy obtained from the power grid at time t; μ 电网 is the carbon emission coefficient of the power grid, which is the theoretical value of the carbon emission per unit of power grid electrical energy; E 总输出 is the total power generation of the system.

[0024] Preferably, the control layer uses the improved NSGA-III algorithm to solve the Pareto front, and dynamically allocates the power of the pumped storage unit and the carbon capture energy consumption weight of the carbon cycle management unit; wherein the quantum genetic operator of the improved NSGA-III algorithm takes the current optimal solution as input, and optimizes the algorithm performance by enhancing the population diversity and convergence speed;

[0025] The control layer real-time corrects the power of the pumped storage unit according to the following rules: when the actual deviation of the power grid frequency is greater than or equal to 0.1 Hz, the power of the pumped storage unit is corrected by using the PID adjustment mechanism based on the predicted frequency deviation and the actual deviation; otherwise, the predicted value is directly used.

[0026] Preferably, it further comprises a carbon net removal amount calculation unit.

[0027] The carbon net removal amount calculation unit is configured to calculate the theoretical value of the instantaneous carbon emission according to the geothermal fluid flow Q 地热 (t) and the CO2 concentration

[0028]

[0029] Wherein: is the CO2 density; t1 and t2 are the starting time and the ending time of the calculation interval;

[0030] Then, through the blockchain smart contract, the carbon net removal amount is generated by comparing with the sequestration amount Q 封存

[0031] Preferably, it further comprises a hybrid energy storage coordination control unit.

[0032] The hybrid energy storage coordination control unit comprises lithium ion batteries and supercapacitors, and allocates the energy storage output through the following optimization model:

[0033] min(ω1·C 损耗 +ω2·|P 需求 -P 出力 |)​​

[0034] Constraints:

[0035]

[0036] wherein: ω1, ω2 are weight coefficients; C 损耗 is the loss cost of the hybrid energy storage system, including the energy consumption loss cost of the lithium ion battery pack and the super capacitor; P 需求 is the power demand of the hybrid energy storage system to meet the total power load; P 出力 is the actual output power of the hybrid energy storage system; P 抽蓄 is the output power of the pumped storage unit; P 电池 is the output power of the lithium ion battery pack; P 电容 is the output power of the super capacitor; SOC 电池 is the battery state of charge of the lithium ion battery pack; T 电容 is the temperature of the super capacitor;

[0037] Further comprising: an ecological safety monitoring module; the ecological safety monitoring module comprises a water quality sensor, a soil humidity probe and a biological diversity camera terminal, and dynamically adjusts the operating parameters to meet:

[0038] a: dissolved oxygen in the downstream of the reservoir is greater than or equal to 5 mg / L; b: the pH value fluctuation of the surrounding soil is less than or equal to ± 0.5; c: the thermal discharge temperature in the endangered species activity area is less than or equal to 30℃;

[0039] If any index is out of limit, the ORC generator set is automatically triggered to generate power and reduce load or the pumped storage power of the pumped storage unit is limited until the ecological parameters recover to the safety threshold.

[0040] The application also provides a method for carbon neutral energy supply of the pumped storage power station and the geothermal energy cascade utilization, comprising the following steps:

[0041] The geothermal cascade power generation unit is used for geothermal cascade power generation; specifically, the geothermal cascade power generation unit comprises a high-temperature geothermal well, a medium-low temperature geothermal well and a two-stage flash steam turbine generator set; the two-stage flash steam turbine generator set comprises a first-stage steam turbine and a second-stage steam turbine; the high-temperature geothermal steam of the high-temperature geothermal well drives the first-stage steam turbine to generate power, and the residual high-temperature geothermal steam of the high-temperature geothermal well and the medium-low temperature fluid of the medium-low temperature geothermal well are mixed to drive the second-stage steam turbine to generate power;

[0042] The pumped storage unit is used for pumped storage and power generation; specifically, the pumped storage unit comprises a reversible pump turbine, an upper reservoir and a lower reservoir; the reversible pump turbine uses the geothermal power generation surplus power of the geothermal cascade power generation unit and the grid surplus power to store water in the low valley period of the grid load, and releases water from the upper reservoir to the lower reservoir to generate power in the peak period.

[0043] The waste heat-potential energy coupling unit is used for coupling between the waste heat of the geothermal tail water and the preheating of the pumped storage pipeline; specifically, the waste heat-potential energy coupling unit comprises a waste heat recovery heat exchanger, an ORC generator set and a phase change heat storage tank; based on the waste heat recovery heat exchanger, the ORC generator set generates power by using the waste heat of the geothermal tail water of the geothermal staged power generation unit, the waste heat generated in power generation is stored in the phase change heat storage tank, and the phase change heat storage tank provides anti-freezing preheating for the pumped storage pipeline of the pumped storage unit through a heat pump;

[0044] The carbon cycle management unit is used for capturing the geothermal tail gas and separating out CO2, and then mineralizing and sealing; specifically, the carbon cycle management unit comprises a geothermal fluid CO2 separation device, a mineralization sealing well and a carbon sink monitoring terminal; the geothermal fluid CO2 separation device captures the geothermal tail gas of the geothermal staged power generation unit by using an amine liquid-membrane separation composite process, separates out CO2, and injects the separated CO2 into a basalt layer for mineralization by using the water pressure of the lower reservoir of the pumped storage unit; the carbon sink monitoring terminal is used for monitoring the carbon sink of the geothermal tail gas treated by the geothermal fluid CO2 separation device;

[0045] The intelligent collaborative regulation unit is used for dynamically allocating the power of the pumped storage unit and the carbon capture energy consumption weight of the carbon cycle management unit; specifically, the intelligent collaborative regulation unit is deployed on an edge computing node and comprises a prediction layer, an optimization layer and a control layer; the prediction layer is used for predicting the future 12-hour power grid load and the geothermal output of the geothermal staged power generation unit; the optimization layer is used for establishing a target function of maximum benefit and minimum carbon emission intensity; and the control layer is used for dynamically allocating the power of the pumped storage unit and the carbon capture energy consumption weight of the carbon cycle management unit according to the prediction result of the prediction layer and taking the target function of the optimization layer as a target, so that the system comprehensive energy efficiency and the whole life cycle carbon emission intensity meet the set target.

[0046] The carbon neutral energy supply system and method provided by the application have the following advantages:

[0047] The application solves the industry problems of traditional pumped storage depending on high-carbon power, low utilization rate of geothermal resources and insufficient system flexibility by means of the three-in-one architecture of multi-energy cascade utilization-carbon closed-loop management-intelligent dynamic optimization, and realizes four breakthroughs of energy efficiency, low-carbon operation, intelligent management and control and diversified benefits, thereby providing a replicable and popularized carbon neutral solution for building a new power system. BRIEF DESCRIPTION OF DRAWINGS

[0048] Figure 1 The flowchart of the carbon neutral energy supply method for the pumped storage power station and the geothermal energy cascade utilization provided by the application is shown. Detailed Implementation

[0049] 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 embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0050] Please see Figure 1 The present invention provides the following technical solutions:

[0051] This invention provides a carbon-neutral energy supply system for pumped storage power stations and geothermal energy cascade utilization, comprising: a geothermal cascade power generation unit, a pumped storage unit, a waste heat-potential energy coupling unit, a carbon cycle management unit, and an intelligent collaborative control unit.

[0052] Specifically, the geothermal graded power generation unit, pumped storage unit, waste heat-potential energy coupling unit, carbon cycle management unit, and intelligent collaborative control unit form a closed-loop carbon-neutral energy supply system through the three-dimensional coordination of energy flow, material flow, and information flow.

[0053] Energy flow: the stepwise conversion and complementarity of thermal energy → electrical energy → potential energy;

[0054] Breaking away from the traditional single-energy utilization model, we can achieve the full-chain development of multi-grade thermal energy;

[0055] Material flow: Closed-loop management of geothermal fluid → CO2 → mineralized products;

[0056] Information flow: Data-driven multi-objective dynamic optimization;

[0057] Data-driven intelligence can be used to resolve multi-objective conflicts in complex systems (such as economic efficiency versus low carbon emissions).

[0058] The following is a detailed introduction to each unit:

[0059] (I) Geothermal graded power generation unit

[0060] The geothermal staged power generation unit includes a high-temperature geothermal well (150-300℃), a medium-low temperature geothermal well (80-150℃), and a two-stage flash evaporation generator set; the two-stage flash evaporation generator set includes a first-stage steam turbine and a second-stage steam turbine; the high-temperature geothermal steam from the high-temperature geothermal well drives the first-stage steam turbine to generate electricity, and the remaining high-temperature geothermal steam from the high-temperature geothermal well is mixed with the medium-low temperature fluid from the medium-low temperature geothermal well to drive the second-stage steam turbine to generate electricity.

[0061] (II) Pumped Storage Unit

[0062] The pumped storage unit comprises a reversible pump turbine, an upper reservoir and a lower reservoir; the reversible pump turbine uses the geothermal power surplus electricity and the grid surplus electricity of the geothermal grading power generation unit to pump and store water during the low load period of the power grid, and generates electricity by releasing water from the upper reservoir to the lower reservoir during the peak period.

[0063] (Three) waste heat-potential energy coupling unit

[0064] The waste heat-potential energy coupling unit comprises a waste heat recovery heat exchanger, an ORC generator set and a phase change heat storage tank; based on the waste heat recovery heat exchanger, the ORC generator set uses the geothermal tail water waste heat (50-80℃) of the geothermal grading power generation unit to generate electricity, and the generated waste heat (30-50℃) is stored in the phase change heat storage tank, and the heat pump provides anti-freezing preheating for the pumped storage pipeline of the pumped storage unit;

[0065] Specifically, the waste heat power generation efficiency is improved: through the dynamic pressure matching formula, the ORC unit is ensured to operate at the maximum efficiency within the safety margin ΔP 安全 , and the waste heat power generation efficiency is improved higher. The system stability is enhanced; the equipment wear caused by pressure mismatch is avoided, and the service life of the ORC unit is prolonged.

[0066] In the waste heat-potential energy coupling unit, the heat release rate of the phase change heat storage tank satisfies:

[0067]

[0068] Where: T 储热 is the time constant of the heat storage material, the pipe heat loss is reduced by 60% by optimizing the U·A value; U: heat transfer coefficient, unit: W / (m 2 ·K), indicating the heat transfer efficiency between the phase change heat storage tank material and the pumped storage pipeline, the larger the value, the stronger the heat transfer capacity; A: heat exchange area, unit: m 2 , is the effective heat transfer area of the phase change heat storage tank and the pumped storage pipeline; Tpipe: real-time temperature of the pumped storage pipeline wall, unit: ℃ or K, is the outer wall temperature of the pumped storage pipeline that needs to be preheated to prevent freezing, which is monitored by a temperature sensor in real time; t is a time variable.

[0069] (Four) carbon cycle management unit

[0070] The carbon cycle management unit comprises a geothermal fluid CO2 separation device, a mineralization storage well, and a carbon sink monitoring terminal. The geothermal fluid CO2 separation device uses an amine liquid-membrane separation composite process to capture geothermal tail gas from the geothermal staged power generation unit, separates out CO2, and uses the mineralization storage well to inject the separated CO2 into a basalt layer for mineralization using the water pressure of the lower reservoir of the pumped storage unit. The carbon sink monitoring terminal is used to monitor the carbon sink of the geothermal tail gas treated by the geothermal fluid CO2 separation device.

[0071] The CO2 mineralization reaction rate in the carbon cycle management unit is calculated in real time, and its value is related to the reaction constant, activation energy, temperature, applied pressure of the lower reservoir, and fracture surface area of the rock layer. The calculation formula is as follows:

[0072]

[0073] Wherein: k0 is the reaction constant, E a is the activation energy, P 水压 is the applied pressure of the lower reservoir, S 裂隙 is the fracture surface area of the rock layer, R is the gas constant, and T is the absolute temperature.

[0074] Specifically, based on the above formula, the mineralization rate is monitored, the storage efficiency is high, and precise storage control is achieved. The water pressure of the pumped storage lower reservoir is used to drive storage, without additional energy consumption, reducing the cost of carbon capture.

[0075] (Five) Intelligent collaborative regulation unit

[0076] The intelligent collaborative regulation unit is deployed on an edge computing node and includes a prediction layer, an optimization layer, and a control layer.

[0077] The prediction layer is used to predict the future 12-hour power grid load and geothermal output of the geothermal staged power generation unit. The optimization layer is used to establish a target function of maximum benefit and minimum carbon emission intensity. The control layer is used to dynamically allocate the power of the pumped storage unit and the carbon capture energy consumption weight of the carbon cycle management unit based on the prediction results of the prediction layer and the target function of the optimization layer, so that the system comprehensive energy efficiency and life cycle carbon emission intensity meet the set target.

[0078] The prediction layer uses an LSTM-Attention neural network to predict the future 12-hour power grid load and geothermal output of the geothermal staged power generation unit, and the hidden state update formula is as follows:

[0079] h t =LSTM(x t ,h t-1 ),α t =softmax(W a [ht ;H history ]);

[0080] wherein: h t is the hidden state at time t, which is the hidden state at the current time in the LSTM-Attention neural network; h t-1 is the hidden state at time t-1, which is the hidden state at the previous time in the LSTM-Attention neural network; x t is the input vector at time t, which is used as the input of the LSTM-Attention neural network; H history is the historical load sequence encoding vector; W a is the attention weight matrix; α t is the attention weight at time t, which is used to weight the importance of the historical sequence in the LSTM-Attention neural network.

[0081] Loss function of the LSTM-Attention neural network Add a carbon intensity regularization term:

[0082]

[0083] wherein: γ is a regularization coefficient, which forces the model to preferentially learn low-carbon emission scheduling strategies.

[0084] The multi-objective function F constructed by the optimization layer is:

[0085] F = λ1f 收益 + λ2f 碳强度

[0086]

[0087] wherein: λ1 is a weight coefficient of the revenue target, which is used for weighting the revenue target in the multi-objective function; λ2 is a weight coefficient of the carbon intensity target, which is used for weighting the carbon intensity target in the multi-objective function; f 收益 is the revenue function, which represents the economic revenue target of the system; f 碳强度 is the carbon intensity function, which represents the carbon emission intensity target of the system; t is time; T is the period, which is the time interval for calculating the revenue and carbon intensity; P 售电 (t) is the electricity selling price at time t; E 发电 (t) is the power generation of the pumped storage unit at time t; C 抽蓄 (t) is the pumped storage cost of the pumped storage unit at time t; Q CO2 is the CO2 storage capacity of the carbon cycle management unit; P 碳价 is the transaction price per unit of carbon; E 地热 (t) is the geothermal power generation of the geothermal grading power generation unit at time t; μ地热 is the carbon emission coefficient of the geothermal grading power generation unit, which is a theoretical value of carbon emission corresponding to a unit of geothermal power generation; E 电网 (t) is the power obtained from the power grid at time t; μ 电网 is the carbon emission coefficient of the power grid, which is a theoretical value of carbon emission corresponding to a unit of power grid power; E 总输出 is the total power generation of the system.

[0088] The control layer solves the Pareto front by using an improved NSGA-III algorithm, dynamically allocates the power of the pumped storage unit and the carbon capture energy consumption weight of the carbon cycle management unit, and makes the system meet the following conditions: comprehensive energy efficiency 288%, and life cycle carbon intensity ≤0.03 kgCO2 / kWh. The quantum genetic operator of the improved NSGA-III algorithm takes the current optimal solution as input, and optimizes the algorithm performance by enhancing population diversity and convergence speed. Specifically, the quantum genetic operator Q-Gate(x i is guided by the adaptive mutation coefficient β and the elite solution x 精英 , enhances population diversity, avoids falling into local optimum, and has high algorithm convergence speed. The delay of the Pareto solution set screening is ≤200 ms, which ensures the real-time dynamic balance of the power grid peak shaving and carbon intensity target.

[0089] The control layer real-time corrects the power of the pumped storage unit according to the following rules: when the actual deviation of the power grid frequency is ≥0.1 Hz, the power of the pumped storage unit is corrected by using a PID adjustment mechanism based on the predicted frequency deviation and the actual deviation; otherwise, the predicted value is directly used. The formula is as follows:

[0090]

[0091] Where: P 抽蓄 (t) is the power of the pumped storage unit at time t; Δf(t) is the actual deviation of the power grid frequency at time t; P 预测 is the predicted deviation of the power grid frequency by the prediction layer; K p ,K i are PID adjustment parameters; Δf(τ) is the actual deviation of the power grid frequency at time τ from 0 to t.

[0092] Specifically, the PID adjustment formula responds within seconds when the deviation of the power grid frequency is ≥0.1 Hz, and the frequency fluctuation is suppressed to ≤0.05 Hz; the peak shaving reliability is improved: the risk of load shedding caused by the response delay of traditional pumped storage is reduced by more than 50%.

[0093] In the application, through the coupling of geothermal step-by-step power generation, pumped storage peak regulation and waste heat step-by-step utilization, three-level conversion of thermal energy-electric energy-potential energy is realized, and the comprehensive energy efficiency is improved to >=88%, which is significantly higher than the efficiency of traditional pumped storage system (70%-80%).

[0094] The application integrates CO2 capture and mineralization storage technology, and the carbon intensity of the system in the whole life cycle is <=0.03 kgCO2 / kWh, which directly supports the carbon neutralization target.

[0095] The application is based on LSTM-Attention prediction and NSGA-III multi-objective optimization algorithm, realizes second-level response (delay <=200 ms), and takes into account economic benefits and low-carbon operation.

[0096] (Six) carbon net removal amount calculation unit

[0097] The carbon net removal amount calculation unit is used for calculating the carbon net removal amount according to the geothermal fluid flow Q 地热 (t) and the CO2 concentration The theoretical value of the instantaneous carbon emission amount is calculated

[0098]

[0099] Wherein: is the CO2 density; t1 and t2 are the starting time and the ending time of the calculation interval;

[0100] Then, through the blockchain smart contract, the carbon net removal amount is calculated and the storage amount Q 封存 are compared, and the carbon net removal amount is generated, and a tradable certificate is issued.

[0101] (Seven) mixed energy storage coordination control unit

[0102] The mixed energy storage coordination control unit includes a lithium ion battery pack and a super capacitor, and the energy storage output is distributed through the following optimization model:

[0103] min (ω1·C 损耗 +ω2·|P 需求 -P 出力 |)

[0104] Constraint condition:

[0105]

[0106] Wherein: ω1, ω2 are weight coefficients; C 损耗 is the loss cost of the mixed energy storage system, including the energy consumption loss cost of the lithium ion battery pack and the super capacitor; P 需求 is the power demand of the mixed energy storage system to meet the total power load; P 出力P is the actual output power of the hybrid energy storage system; 抽蓄 P is the output power of the pumped storage unit; 电池 P is the output power of the lithium ion battery pack; 电容 P is the output power of the supercapacitor; SOC 电池 P is the battery state of charge (SOC) of the lithium ion battery pack, i.e., the ratio of the current battery capacity to the rated capacity; T 电容 P is the temperature of the supercapacitor.

[0107] (Eight) Ecological safety monitoring module

[0108] The ecological safety monitoring module includes water quality sensors, soil humidity probes, and biodiversity camera terminals, and dynamically adjusts operating parameters to meet:

[0109] a: dissolved oxygen in the downstream of the reservoir is greater than or equal to 5 mg / L; b: the pH value of the surrounding soil fluctuates by less than or equal to ± 0.5; c: the thermal discharge temperature in the endangered species activity area is less than or equal to 30℃;

[0110] If any index exceeds the limit, the ORC generator set is automatically triggered to generate power and reduce load or the pumped storage power of the pumped storage unit is limited until the ecological parameters return to the safety threshold.

[0111] The application also provides a carbon neutral energy supply method for a pumped storage power station and a geothermal energy cascade utilization, comprising the following steps:

[0112] The geothermal cascade power generation unit is used for geothermal cascade power generation; specifically, the geothermal cascade power generation unit includes a high-temperature geothermal well, a medium-low temperature geothermal well, and a two-stage flash steam power generator; the two-stage flash steam power generator includes a first-stage steam turbine and a second-stage steam turbine; the high-temperature geothermal steam of the high-temperature geothermal well drives the first-stage steam turbine to generate power, and the remaining high-temperature geothermal steam of the high-temperature geothermal well and the medium-low temperature fluid of the medium-low temperature geothermal well are mixed to drive the second-stage steam turbine to generate power;

[0113] The pumped storage unit is used for pumped storage and power generation; specifically, the pumped storage unit includes a reversible pump-turbine, an upper reservoir, and a lower reservoir; the reversible pump-turbine uses the geothermal power generation surplus power of the geothermal cascade power generation unit and the grid surplus power to store water during the low load period of the grid, and releases water from the upper reservoir to the lower reservoir to generate power during the peak period;

[0114] The waste heat-potential energy coupling unit is used for coupling between waste heat of geothermal tail water and preheating of a pumped storage pipeline; specifically, the waste heat-potential energy coupling unit comprises a waste heat recovery heat exchanger, an ORC generator set and a phase change heat storage tank; based on the waste heat recovery heat exchanger, the ORC generator set generates power by using waste heat of geothermal tail water of the geothermal staged power generation unit, and waste heat generated in power generation is stored in the phase change heat storage tank, and a heat pump is used to provide anti-freezing preheating for the pumped storage pipeline of the pumped storage unit;

[0115] The carbon cycle management unit is used for capturing geothermal tail gas and separating CO2, and then mineralizing and sealing; specifically, the carbon cycle management unit comprises a geothermal fluid CO2 separation device, a mineralization sealing well and a carbon sink monitoring terminal; the geothermal fluid CO2 separation device uses an amine liquid-membrane separation composite process to capture geothermal tail gas of the geothermal staged power generation unit, separates CO2, and uses the mineralization sealing well to inject the separated CO2 into a basalt layer for mineralization by using water pressure of the lower reservoir of the pumped storage unit; the carbon sink monitoring terminal is used for carbon sink monitoring on geothermal tail gas treated by the geothermal fluid CO2 separation device;

[0116] The intelligent collaborative regulation unit is used for dynamically allocating power of the pumped storage unit and carbon capture energy consumption weight of the carbon cycle management unit; specifically, the intelligent collaborative regulation unit is deployed on an edge computing node and comprises a prediction layer, an optimization layer and a control layer; the prediction layer is used for predicting future 12-hour power grid load and geothermal output of the geothermal staged power generation unit; the optimization layer is used for establishing a target function of maximum benefit and minimum carbon emission intensity; and the control layer is used for dynamically allocating power of the pumped storage unit and carbon capture energy consumption weight of the carbon cycle management unit according to a prediction result of the prediction layer and taking the target function of the optimization layer as a target, so that system comprehensive energy efficiency and whole life cycle carbon emission intensity meet a set target.

[0117] The carbon neutral energy supply system and method for pumped storage power station and geothermal energy cascade utilization provided by the application have the following advantages:

[0118] The application solves the industry problems of traditional pumped storage depending on high-carbon power, low utilization rate of geothermal resources and insufficient system flexibility by means of the three-in-one architecture of multi-energy cascade utilization-carbon closed loop management-intelligent dynamic optimization, and realizes four breakthroughs of energy efficiency, low-carbon operation, intelligent management and control and diversified benefits, thereby providing a replicable and popularized carbon neutral solution for building a new power system.

[0119] While embodiments of the application have been shown and described, it is to be understood that the embodiments described are merely exemplary of the principles and application of the present application. Numerous modifications and adaptions can be effected without departing from the spirit and scope of the present application, which is not limited to the exact construction and arrangement described. It is intended, therefore, to cover all modifications and adaptions that fall within the scope of the claims and their equivalents.

Claims

1. A carbon neutral energy supply system of pumped storage power station and geothermal energy cascade utilization, characterized in that, The application relates to a geothermal power generation system. The geothermal power generation system comprises a geothermal grading power generation unit, a pumped storage unit, a waste heat-potential energy coupling unit, a carbon cycle management unit and an intelligent collaborative regulation unit. The geothermal grading power generation unit comprises high-temperature geothermal wells, medium-low-temperature geothermal wells and two-stage flash evaporation generator sets; the two-stage flash evaporation generator sets comprise a first-stage steam turbine and a second-stage steam turbine; high-temperature geothermal steam of the high-temperature geothermal wells drives the first-stage steam turbine to generate power; and the remaining high-temperature geothermal steam of the high-temperature geothermal wells is mixed with medium-low-temperature fluid of the medium-low-temperature geothermal wells to drive the second-stage steam turbine to generate power. The pumped storage unit comprises a reversible pump-turbine, an upper reservoir and a lower reservoir; the reversible pump-turbine uses geothermal power generation residual power of the geothermal grading power generation unit and grid surplus power to pump and store water during a low-load period of a power grid, and generates power by releasing water from the upper reservoir to the lower reservoir during a peak period. The waste heat-potential energy coupling unit comprises a waste heat recovery heat exchanger, an ORC power generation unit and a phase change heat storage tank; based on the waste heat recovery heat exchanger, the ORC power generation unit uses geothermal tail water waste heat of the geothermal grading power generation unit to generate power, and stores power generation waste heat in the phase change heat storage tank; and the phase change heat storage tank provides anti-freezing preheating for a pumped storage pipeline of the pumped storage unit through a heat pump. The carbon cycle management unit comprises a geothermal fluid CO2 separation device, a mineralization storage well and a carbon sink monitoring terminal; the geothermal fluid CO2 separation device uses an amine-membrane separation composite process to capture geothermal tail gas of the geothermal grading power generation unit, separates out CO2, and injects the separated CO2 into a basalt layer for mineralization by using water pressure of the lower reservoir of the pumped storage unit; and the carbon sink monitoring terminal is used for monitoring carbon sinks of geothermal tail gas treated by the geothermal fluid CO2 separation device. The intelligent collaborative regulation unit is arranged on an edge computing node and comprises a prediction layer, an optimization layer and a control layer; the prediction layer is used for predicting power grid load in the next 12 hours and geothermal output of the geothermal grading power generation unit; the optimization layer is used for establishing a target function of maximum benefit and minimum carbon emission intensity; and the control layer is used for dynamically allocating power of the pumped storage unit and carbon capture energy consumption weight of the carbon cycle management unit according to a prediction result of the prediction layer and according to the target function of the optimization layer, so that system comprehensive energy efficiency and whole life cycle carbon emission intensity meet set targets. The application further comprises a carbon net removal amount calculation unit. The carbon net removal amount calculation unit is configured to calculate a theoretical value of instantaneous carbon emission amount based on the geothermal fluid flow rate and CO concentration . ; wherein: is CO density; and are the start time and end time of the calculation interval; Then, the carbon net removal amount is generated by comparing the sequestration amount with the amount of carbon dioxide released from the carbon sink.

2. The carbon neutral energy supply system of claim 1, wherein, The CO2 mineralization reaction rate in the carbon cycle management unit is calculated in real time, and the value is related to a reaction constant, activation energy, temperature, applied pressure of the lower reservoir and fracture surface area of a rock layer.

3. The carbon-neutral energy supply system of claim 1, wherein, The heat energy release rate of the phase change heat storage tank in the residual heat-potential energy coupling unit satisfies: ； wherein: is the time constant of the thermal storage material, the value of reduces the heat loss of the pipeline by 60%; U: heat transfer coefficient, indicating the heat transfer efficiency between the material of the phase change thermal storage tank and the pumped storage pipeline, the larger the value, the stronger the heat transfer ability; A: heat exchange area, which is the effective heat transfer area of the phase change thermal storage tank in contact with the pumped storage pipeline; Tpipeline: real-time temperature of the pumped storage pipeline wall, which is the outer wall temperature of the pumped storage pipeline that needs to be preheated to prevent freezing, monitored by a temperature sensor; t is the time variable.

4. The carbon-neutral energy supply system of claim 1, wherein, The prediction layer uses an LSTM-Attention neural network to predict power grid load in the next 12 hours and geothermal output of the geothermal grading power generation unit, and a hidden state updating formula of the LSTM-Attention neural network is as follows: ; wherein: : hidden state at time t; : hidden state at time t-1; is an input vector at time t; is a historical load sequence encoding vector; is an attention weight matrix; is an attention weight at time t.

5. The carbon-neutral energy supply system of claim 1, wherein, The multi-objective function for the optimization layer construction Is: ； ； ； wherein: is a weight coefficient of the benefit target; is a weight coefficient of the carbon intensity target; is a benefit function, representing an economic benefit target of the system; is a carbon intensity function, representing a carbon emission intensity target of the system; is time; is a period; is a power selling price at time t; is a power generation amount of the pumped storage unit at time t; is a pumped storage cost of the pumped storage unit at time t; is a CO2 storage amount of the carbon cycle management unit; is a transaction price per unit of carbon; is a geothermal power generation amount of the geothermal staged power generation unit at time t; is a carbon emission coefficient of the geothermal staged power generation unit, being a theoretical value of a carbon emission amount corresponding to a unit of geothermal power generation amount; is an electricity amount obtained from the power grid at time t; is a carbon emission coefficient of the power grid, being a theoretical value of a carbon emission amount corresponding to a unit of power grid electricity amount; is a total power generation amount of the system.

6. The carbon-neutral energy supply system of claim 1, wherein, The control layer solves the Pareto frontier by using an improved NSGA-III algorithm, and dynamically allocates the power of the pumped storage unit and the carbon capture energy consumption weight of the carbon cycle management unit; wherein the quantum genetic operator of the improved NSGA-III algorithm takes the current optimal solution as input, and optimizes the algorithm performance by enhancing population diversity and convergence speed; The control layer real-time corrects the power of the pumped storage unit according to the following rules: when the actual deviation of the grid frequency is greater than or equal to 0.1 Hz, the power of the pumped storage unit is corrected by using a PID adjustment mechanism based on the predicted frequency deviation and the actual deviation; otherwise, the predicted value is directly used.

7. The carbon-neutral energy supply system of claim 1, wherein, Further comprising: A hybrid energy storage coordination control unit; The hybrid energy storage coordination control unit contains lithium ion battery packs and supercapacitors, and allocates energy output by the following optimization model: ； Constraint conditions: ； wherein: is a weight coefficient; is a loss cost of the hybrid energy storage system, including energy consumption loss costs of the lithium-ion battery pack and the supercapacitor; is a power demand of the hybrid energy storage system to meet the total power load; is an actual output power of the hybrid energy storage system; is an output power of the pumped storage unit; is an output power of the lithium-ion battery pack; is an output power of the supercapacitor; is a battery state of charge of the lithium-ion battery pack; is a supercapacitor temperature; Further comprising: an ecological safety monitoring module; the ecological safety monitoring module contains water quality sensors, soil humidity probes, and biodiversity camera terminals, and dynamically adjusts operating parameters to meet: a: dissolved oxygen in the downstream of the reservoir mg / L; b: soil in the periphery fluctuation ; c C; If any index exceeds the limit, the ORC generator set is automatically triggered to generate power and reduce load or the pumped storage power of the pumped storage unit is limited until the ecological parameters return to the safety threshold.

8. The working method of the carbon neutral energy supply system of pumped storage power station and geothermal energy cascade utilization according to any one of claims 1-7, characterized in that, The following steps are included: The geothermal energy is graded and generated by using a geothermal energy grading generation unit; specifically, the geothermal energy grading generation unit includes high-temperature geothermal wells, medium-low temperature geothermal wells, and two-stage flash steam turbine generator sets; the two-stage flash steam turbine generator set includes a primary steam turbine and a secondary steam turbine; the high-temperature geothermal steam of the high-temperature geothermal well drives the primary steam turbine to generate electricity, and the remaining high-temperature geothermal steam of the high-temperature geothermal well and the medium-low temperature fluid of the medium-low temperature geothermal well are mixed to drive the secondary steam turbine to generate electricity; The pumped storage unit is used for pumped storage and power generation; specifically, the pumped storage unit includes a reversible pump-turbine, an upper reservoir, and a lower reservoir; the reversible pump-turbine uses the geothermal power surplus and the grid surplus power of the geothermal energy grading generation unit to pump and store energy during the low load period of the grid, and generates electricity by releasing water from the upper reservoir to the lower reservoir during the peak period; The waste heat-potential energy coupling unit is used for coupling between geothermal tail water waste heat and preheating of the pumped storage pipeline; specifically, the waste heat-potential energy coupling unit includes a waste heat recovery heat exchanger, an ORC generator set, and a phase change heat storage tank; based on the waste heat recovery heat exchanger, the ORC generator set uses the geothermal tail water waste heat of the geothermal energy grading generation unit to generate electricity, the generated waste heat is stored in the phase change heat storage tank, and the heat pump is used to provide anti-freezing preheating for the pumped storage pipeline of the pumped storage unit. The carbon cycle management unit is used to capture geothermal tail gas and separate CO2 for mineralization sealing; specifically, the carbon cycle management unit comprises a geothermal fluid CO2 separation device, a mineralization sealing well and a carbon sink monitoring terminal; the geothermal fluid CO2 separation device uses an amine-membrane separation composite process to capture geothermal tail gas of the geothermal staged power generation unit, separate CO2, and inject the separated CO2 into a basalt layer for mineralization using the water pressure of the lower reservoir of the pumped storage unit; the carbon sink monitoring terminal is used to monitor the carbon sink of geothermal tail gas treated by the geothermal fluid CO2 separation device; The intelligent collaborative regulation unit is used to dynamically allocate the power of the pumped storage unit and the carbon capture energy consumption weight of the carbon cycle management unit; specifically, the intelligent collaborative regulation unit is deployed on an edge computing node and comprises a prediction layer, an optimization layer and a control layer; the prediction layer is used to predict the future 12-hour power grid load and the geothermal output of the geothermal staged power generation unit; the optimization layer is used to establish a target function of maximum benefit and minimum carbon emission intensity; the control layer is used to dynamically allocate the power of the pumped storage unit and the carbon capture energy consumption weight of the carbon cycle management unit according to the prediction result of the prediction layer and the target function of the optimization layer as the target, so that the system comprehensive energy efficiency and the whole life cycle carbon emission intensity meet the set target.

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