Pumped storage power station and geothermal energy gradient utilization carbon neutralization energy supply system and method

Abstract

The invention provides a pumped storage power station and geothermal energy gradient utilization carbon neutralization energy supply system and method. The system comprises a geothermal graded power generation unit, a pumped storage unit, a waste heat-potential energy coupling unit, a carbon cycle management unit and an intelligent cooperative regulation and control unit. The terrestrial heat grading power generation unit comprises a high-temperature terrestrial heat well, a medium-low temperature terrestrial heat well and a two-stage flash evaporation generator set, high-temperature terrestrial heat steam drives a first-stage steam turbine to generate power, and residual steam and medium-low temperature fluid are mixed to drive a second-stage steam turbine to generate power. Through a three-in-one framework of'multi-energy gradient utilization, carbon closed-loop management and intelligent dynamic optimization ', the industrial problems that traditional pumped storage depends on high-carbon electric power, the utilization rate of geothermal resources is low and the system flexibility is insufficient are solved, and quadruple breakthrough of'high energy efficiency, low operation carbon, intelligent management and control and diverse benefits' is achieved; and a replicable and generalizable carbon neutralization solution is provided for constructing a novel power system.

Description

Technical Field

[0001] The present invention relates to the field of pumped storage and carbon neutrality technology, and specifically to a carbon neutral energy supply system and method for cascade utilization of a pumped storage power station and geothermal energy. Background Art

[0002] While existing pumped-storage hydropower stations are widely used for grid peak load regulation, their energy conversion efficiency is relatively low, and the pumping phase relies on high-carbon grid electricity, indirectly increasing carbon emissions. Geothermal energy utilization is limited by the low power generation efficiency of medium- and low-temperature resources, the lack of waste heat recovery from tailwater, and associated greenhouse gas emissions, resulting in energy waste and an increased carbon footprint. Operating independently, neither approach can meet carbon neutrality targets.

[0003] Existing combined technologies attempt to simply couple pumped storage with geothermal energy, such as using excess electricity from geothermal power generation to drive water pumps. However, this fails to establish a cascaded utilization chain from thermal energy to electrical energy to potential energy. Consequently, the excess heat from geothermal tailwater remains wasted, resulting in less than a 5% improvement in overall energy efficiency. Furthermore, the system lacks dynamic control capabilities, making it unable to respond to changes in grid and geothermal parameters. Furthermore, the closed-loop carbon emissions issue of geothermal development remains unresolved, and the carbon intensity of the entire life cycle remains excessive.

[0004] The core problem of traditional solutions lies in the gap in energy utilization and the lack of carbon management: traditional solutions fail to achieve multi-energy complementary optimization and negative carbon technology integration, resulting in low resource utilization and poor economic efficiency. Summary of the Invention

[0005] In response to the defects of the existing technology, the present invention provides a carbon-neutral energy supply system and method for cascade utilization of pumped storage power stations and geothermal energy, which can effectively solve the above problems.

[0006] The technical solution adopted in the present invention is as follows:

[0007] The present invention provides a carbon-neutral energy supply system for pumped storage power stations and cascade utilization of geothermal energy, comprising: a geothermal hierarchical power generation unit, a pumped storage unit, a waste heat-potential energy coupling unit, a carbon cycle management unit, and an intelligent coordinated control unit;

[0008] The geothermal staged power generation unit comprises a high-temperature geothermal well, a medium-low temperature geothermal well, and a two-stage flash evaporation generator set; the two-stage flash evaporation generator set comprises 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;

[0009] The pumped storage unit comprises a reversible pump-turbine, an upper reservoir and a lower reservoir; the reversible pump-turbine utilizes the surplus power generated by the geothermal staged power generation unit and the surplus power of the power grid to pump and store water during the off-peak period of the power grid, and releases water from the upper reservoir to the lower reservoir to generate electricity during the peak period;

[0010] 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 waste heat of the geothermal tail water of the geothermal staged power generation unit to generate electricity, and the waste heat from power generation is stored in the phase-change heat storage tank. The heat pump is used to provide anti-freezing preheating for the pumped storage pipeline of the pumped storage unit.

[0011] The carbon cycle management unit includes a geothermal fluid CO2 separation device, a mineralized 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 CO2, and uses the mineralized storage well to utilize the water pressure of the lower reservoir of the pumped storage unit to inject the separated CO2 into the basalt layer for mineralization; 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;

[0012] The intelligent collaborative control unit is deployed on the edge computing node and includes a prediction layer, an optimization layer and a control layer; the prediction layer is used to predict the grid load and the geothermal output of the geothermal staged power generation unit in the next 12 hours; the optimization layer is used to establish an objective function with 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 objective function of the optimization layer, so that the system's comprehensive energy efficiency and full life cycle carbon emission intensity meet the set targets.

[0013] Preferably, in the geothermal staged power generation unit, the exhaust pressure P of the secondary steam turbine is turbine The optimal evaporator pressure P of the ORC generator set with the waste heat-potential energy coupling unit ORC Satisfy the dynamic matching formula:

[0014] P ORC =argminf[(η ORC (P,P turbine )-0.8·η ORC,max ) 2 +(P turbine -P-ΔP 安全 ) 2 ]

[0015] Where: P ORCis the optimal pressure of the evaporator of the ORC generator set, is the optimization target; η ORC,max is the maximum theoretical efficiency of the ORC generator set, ΔP 安全 is the pressure safety margin threshold; P is the evaporator pressure of the ORC generator set; η ORC (P,P turbine ) is the pressure of the ORC generator set when the evaporator pressure is P and the exhaust pressure of the second-stage steam turbine is P turbine The actual efficiency under ; f[] represents the objective function.

[0016] Preferably, 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, pressure applied by the lower reservoir and the surface area of ​​rock fractures.

[0017] Preferably, in the waste heat-potential energy coupling unit, the heat energy release rate of the phase change heat storage tank is satisfy:

[0018]

[0019] Where: T 储热 is the time constant of the heat storage material. By optimizing the U·A value, the heat loss in the pipeline was reduced by 60%; U is the heat transfer coefficient, which represents the heat conduction efficiency between the material of the phase change heat storage tank and the pumped storage pipeline. A larger value indicates a stronger heat transfer capacity; A is the heat exchange area, which is the effective heat transfer area in contact between the phase change heat storage tank and the pumped storage pipeline; Tpipe is the real-time temperature of the pumped storage pipeline wall, which is the temperature of the outer wall of the pumped storage pipeline that needs to be preheated for antifreeze protection and is monitored in real time by a temperature sensor; t is the time variable.

[0020] Preferably, the prediction layer uses an LSTM-Attention neural network to predict the grid load and the geothermal output of the geothermal hierarchical power generation unit in the next 12 hours, and its hidden state update formula is:

[0021] h t =LSTM(x t ,h t-1 ),α t =softmax(W a [h t ;H history ]);

[0022] 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 W is the encoding vector of the historical load sequence; a is the attention weight matrix; α tis the attention weight at time t.

[0023] Preferably, the multi-objective function F constructed by the optimization layer is:

[0024] F=λ1f 收益 +λ2f 碳强度

[0025]

[0026] Where: λ1 is the weight coefficient of the income target; λ2 is the weight coefficient of the carbon intensity target; f 收益 is the profit function, which represents the economic profit 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; 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 is the transaction price per unit carbon; E 地热 (t) is the geothermal power generation of the geothermal hierarchical power generation unit at time t; μ 地热 is the carbon emission coefficient of the geothermal hierarchical power generation unit, which is the theoretical value of carbon emissions per unit geothermal power generation; E 电网 (t) is the electric energy obtained from the grid at time t; μ 电网 is the carbon emission coefficient of the power grid, which is the theoretical value of carbon emissions per unit of power grid electricity; E 总输出 is the total power generation of the system.

[0027] Preferably, the control layer uses an improved NSGA-III algorithm to solve the Pareto front and dynamically allocate 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 contemporary optimal solution as input and optimizes the algorithm performance by enhancing population diversity and convergence speed;

[0028] The control layer corrects the power of the pumped storage unit in real time according to the following rules: when the actual deviation of the grid frequency is ≥0.1 Hz, the power of the pumped storage unit is corrected using a PID adjustment mechanism based on the predicted frequency deviation and the actual deviation; in other cases, the predicted value is directly used.

[0029] Preferably, it further comprises: a carbon net removal amount calculation unit;

[0030] The carbon net removal calculation unit is used to calculate the carbon net removal amount according to the geothermal fluid flow rate Q 地热(t) and CO2 concentration Calculate the theoretical value of instantaneous carbon emissions

[0031]

[0032] in: is the CO2 density; t1 and t2 are the starting and ending times of the calculation interval;

[0033] Then, through the blockchain smart contract and storage volume Q 封存 Comparison to generate net carbon removal.

[0034] Preferably, it further comprises: a hybrid energy storage coordination control unit;

[0035] The hybrid energy storage coordination control unit includes a lithium-ion battery pack and supercapacitors, and allocates energy storage output through the following optimization model:

[0036] min(ω1·C 损耗 +ω2·|P 需求 -P 出力 |)

[0037] Constraints:

[0038]

[0039] Among them: ω1, ω2 are weight coefficients; C 损耗 is the loss cost of the hybrid energy storage system, including the energy loss cost of lithium-ion battery packs and supercapacitors; P 需求 P is the power requirement of the hybrid energy storage system to meet the total power load; 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 supercapacitor; SOC 电池 is the battery state of charge of the lithium-ion battery pack; T 电容 is the supercapacitor temperature;

[0040] It also includes: an ecological security monitoring module; the ecological security monitoring module includes a water quality sensor, a soil moisture probe and a biodiversity camera terminal, and dynamically adjusts operating parameters to meet:

[0041] a: Dissolved oxygen downstream of the reservoir ≥ 5 mg / L; b: Fluctuation of pH value of surrounding soil ≤ ± 0.5; c: Heat emission temperature in the endangered species activity area ≤ 30°C;

[0042] If any indicator exceeds the limit, the ORC generator set will automatically reduce its power generation load or the pumped storage unit will be limited in its pumped storage power until the ecological parameters return to the safety threshold.

[0043] The present invention also provides a method for a carbon-neutral energy supply system for a pumped storage power station and cascade utilization of geothermal energy, comprising the following steps:

[0044] A geothermal staged power generation unit is used for geothermal staged power generation; specifically, the geothermal staged power generation unit includes a high-temperature geothermal well, a medium-low temperature geothermal well, 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;

[0045] A 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 utilizes the surplus power generated by the geothermal staged power generation unit and the surplus power of the power grid to pump and store water during off-peak periods of the power grid, and releases water from the upper reservoir to the lower reservoir to generate electricity during peak periods;

[0046] A waste heat-potential energy coupling unit is used to couple the waste heat of geothermal tailwater with 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 generates electricity using the waste heat of the geothermal tailwater of the geothermal staged power generation unit, and the waste heat from power generation is stored in the phase change heat storage tank. The heat pump is used to provide anti-freeze preheating for the pumped storage pipeline of the pumped storage unit.

[0047] A carbon cycle management unit is used to capture geothermal tail gas and separate CO2, which is then mineralized and stored. Specifically, the carbon cycle management unit includes a geothermal fluid CO2 separation device, a mineralized storage well, and a carbon sink monitoring terminal. The geothermal fluid CO2 separation device uses an amine liquid-membrane separation composite process to capture the geothermal tail gas of the geothermal staged power generation unit and separate the CO2. The mineralized storage well utilizes the water pressure of the lower reservoir of the pumped storage unit to inject the separated CO2 into the basalt layer for mineralization. The carbon sink monitoring terminal is used to monitor the carbon sink of the geothermal tail gas after it has been treated by the geothermal fluid CO2 separation device.

[0048] An intelligent collaborative control 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 control unit is deployed on the edge computing node, and includes a prediction layer, an optimization layer and a control layer; the prediction layer is used to predict the grid load and the geothermal output of the geothermal staged power generation unit in the next 12 hours; the optimization layer is used to establish an objective function with 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 results of the prediction layer and the objective function of the optimization layer, so that the system's comprehensive energy efficiency and full life cycle carbon emission intensity meet the set targets.

[0049] The carbon-neutral energy supply system and method for cascade utilization of pumped storage power stations and geothermal energy provided by the present invention have the following advantages:

[0050] Through the three-in-one architecture of "multi-energy cascade utilization-carbon closed-loop management-intelligent dynamic optimization", this invention has overcome the industry difficulties of traditional pumped storage's reliance on high-carbon electricity, low utilization of geothermal resources, and insufficient system flexibility, and achieved four breakthroughs in "energy efficiency, low-carbon operation, intelligent management and control, and diversified benefits", providing a replicable and popularizable carbon neutral solution for building a new power system. BRIEF DESCRIPTION OF THE DRAWINGS

[0051] Figure 1 A flow chart of a carbon-neutral energy supply method for cascade utilization of a pumped storage power station and geothermal energy provided by the present invention. DETAILED DESCRIPTION

[0052] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0053] See also Figure 1 , the present invention provides the following technical solutions:

[0054] The present invention provides a carbon-neutral energy supply system for pumped-storage power stations and cascade utilization of geothermal energy, including: a geothermal staged power generation unit, a pumped storage unit, a waste heat-potential energy coupling unit, a carbon cycle management unit and an intelligent coordinated control unit.

[0055] Specifically, the geothermal staged 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.

[0056] Energy flow: step-by-step conversion and complementation of thermal energy → electrical energy → potential energy;

[0057] Break the traditional single energy utilization model and realize the full-chain development of multi-grade thermal energy;

[0058] Material flow: closed-loop management of geothermal fluid → CO2 → mineralized products;

[0059] Information flow: data-driven multi-objective dynamic optimization;

[0060] Driven by data intelligence, we can solve multi-objective conflicts in complex systems (such as economy vs. low carbon).

[0061] The following is a detailed introduction to each unit:

[0062] (1) Geothermal hierarchical power generation unit

[0063] The geothermal staged power generation unit includes a high-temperature geothermal well (150-300°C), a medium-low temperature geothermal well (80-150°C) 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.

[0064] (2) Pumped storage unit

[0065] The pumped storage unit includes a reversible pump-turbine, an upper reservoir and a lower reservoir; the reversible pump-turbine utilizes the surplus power generated by geothermal power generation of the geothermal staged power generation unit and the surplus power of the power grid to pump and store energy during the off-load period of the power grid, and releases water from the upper reservoir to the lower reservoir to generate electricity during the peak period.

[0066] (3) Waste heat-potential energy coupling unit

[0067] 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 waste heat (50-80°C) of the geothermal tail water of the geothermal staged power generation unit to generate electricity. The waste heat (30-50°C) is stored in the phase-change heat storage tank and used to provide anti-freezing preheating for the pumped storage pipeline of the pumped storage unit through a heat pump.

[0068] Specifically, the exhaust pressure P of the second-stage steam turbine in the geothermal staged power generation unit is turbine The optimal evaporator pressure P of the ORC generator set with the waste heat-potential energy coupling unit ORC Satisfy the dynamic matching formula:

[0069] P ORC =argminf[(η ORC (P,P turbine )-0.8·η ORC,max ) 2 +(P turbine -P-ΔP 安全 ) 2 ]

[0070] Where: P ORC is the optimal pressure of the evaporator of the ORC generator set, is the optimization target; η ORC,max is the maximum theoretical efficiency of the ORC generator set, ΔP 安全 is the pressure safety margin threshold; P is the evaporator pressure of the ORC generator set; η ORC (P,P turbine ) is the pressure of the ORC generator set when the evaporator pressure is P and the exhaust pressure of the second-stage steam turbine is P turbine The actual efficiency under ; f[] represents the objective function.

[0071] Specifically, the waste heat power generation efficiency is improved: through the dynamic pressure matching formula, the ORC unit is ensured to have a safety margin ΔP 安全 The system operates at maximum efficiency, significantly improving waste heat power generation efficiency. This enhances system stability, avoids equipment wear caused by pressure mismatch, and extends the life of the ORC unit.

[0072] In the waste heat-potential energy coupling unit, the heat energy release rate of the phase change heat storage tank is satisfy:

[0073]

[0074] Where: T 储热 is the time constant of the heat storage material. By optimizing the U·A value, the heat loss of the pipeline is reduced by 60%; U: heat transfer coefficient, unit: W / (m 2 K), which represents the heat transfer efficiency between the material of the phase change heat storage tank 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 between the phase change heat storage tank and the pumped storage pipeline; Tpipeline: real-time temperature of the pumped storage pipeline wall, unit: ℃ or K, is the temperature of the outer wall of the pumped storage pipeline that needs to be preheated for antifreeze, and is monitored in real time by the temperature sensor; t is the time variable.

[0075] (4) Carbon cycle management unit

[0076] The carbon cycle management unit includes a geothermal fluid CO2 separation device, a mineralized 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 CO2, and uses the mineralized storage well to utilize the water pressure of the lower reservoir of the pumped storage unit to inject the separated CO2 into the basalt layer for mineralization; 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;

[0077] The CO2 mineralization reaction rate in the carbon cycle management unit is calculated in real time. Its value is related to the reaction constant, activation energy, temperature, pressure applied by the lower reservoir, and the surface area of ​​the rock fracture. The calculation formula is as follows:

[0078]

[0079] Where: k0 is the reaction constant, E a is the activation energy, P 水压 Apply pressure to the lower reservoir, S 裂隙 is the surface area of ​​rock fractures, R is the gas constant, and T is the absolute temperature.

[0080] Specifically, the above formula is used to monitor the mineralization rate, achieve high storage efficiency, and achieve precise storage control. Using pumped storage reservoir water pressure to drive storage eliminates the need for additional energy consumption and reduces carbon capture costs.

[0081] (5) Intelligent collaborative control unit

[0082] The intelligent collaborative control unit is deployed on the edge computing node and includes a prediction layer, an optimization layer, and a control layer;

[0083] The prediction layer is used to predict the grid load and the geothermal output of the geothermal staged power generation unit in the next 12 hours; the optimization layer is used to establish an objective function for maximizing benefits and minimizing 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 objective function of the optimization layer, so that the system's comprehensive energy efficiency and full life cycle carbon emission intensity meet the set targets.

[0084] The prediction layer uses the LSTM-Attention neural network to predict the grid load and the geothermal output of the geothermal hierarchical power generation unit in the next 12 hours. The hidden state update formula is:

[0085] h t =LSTM(x t ,h t-1 ),α t =softmax(W a [ht ;H history ]);

[0086] Where: h t : The hidden state at time t, which is the hidden state at the current moment in the LSTM-Attention neural network; h t-1 : The hidden state at time t-1, which is the hidden state of the previous moment in the LSTM-Attention neural network; x t is the input vector at time t, used as the input of the LSTM-Attention neural network; H history W is the encoding vector of the historical load sequence; a is the attention weight matrix; α t is the attention weight at time t, which is used to weight the importance of historical sequences in the LSTM-Attention neural network.

[0087] Loss function of LSTM-Attention neural network Add carbon intensity regularization term:

[0088]

[0089] Where: γ is the regularization coefficient, which forces the model to prioritize learning low-carbon emission scheduling strategies.

[0090] The multi-objective function F constructed by the optimization layer is:

[0091] F=λ1f 收益 +λ2f 碳强度

[0092]

[0093] Where: λ1 is the weight coefficient of the benefit target, which is used to weight the benefit target in the multi-objective function; λ2 is the weight coefficient of the carbon intensity target, which is used to weight the carbon intensity target in the multi-objective function; f 收益 is the profit function, which represents the economic profit 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 benefits and carbon intensity; 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 is the transaction price per unit carbon; E 地热 (t) is the geothermal power generation of the geothermal hierarchical power generation unit at time t; μ地热 is the carbon emission coefficient of the geothermal hierarchical power generation unit, which is the theoretical value of carbon emissions per unit geothermal power generation; E 电网 (t) is the electric energy obtained from the grid at time t; μ 电网 is the carbon emission coefficient of the power grid, which is the theoretical value of carbon emissions per unit of power grid electricity; E 总输出 is the total power generation of the system.

[0094] The control layer uses the improved NSGA-III algorithm to solve the Pareto frontier and dynamically allocates the power of the pumped storage unit and the carbon capture energy consumption weight of the carbon cycle management unit, so that the system meets the following requirements: comprehensive energy efficiency of 288% and full life cycle carbon intensity ≤ 0.03kgCO2 / kWh. The quantum genetic operator of the improved NSGA-III algorithm takes the contemporary 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 ) through adaptive coefficient of variation β and elite solution x 精英 Guidance enhances population diversity, avoids falling into local optima, and significantly improves algorithm convergence speed. Pareto solution set screening delay is ≤ 200ms, ensuring a real-time dynamic balance between grid peak regulation and carbon intensity targets.

[0095] The control layer corrects the power of the pumped storage unit in real time according to the following rules: when the actual grid frequency deviation is ≥0.1Hz, the PID adjustment mechanism based on the predicted frequency deviation and the actual deviation is used to correct the power of the pumped storage unit; in other cases, the predicted value is directly used. The formula is as follows:

[0096]

[0097] Where: P 抽蓄 (t) is the power of the pumped storage unit at time t; Δf(t) is the actual deviation of the grid frequency at time t; P 预测 K is the grid frequency deviation predicted by the prediction layer; p ,K i is the PID adjustment parameter; Δf(τ) is the actual deviation of the grid frequency at time τ from 0 to time t.

[0098] Specifically, through the PID adjustment formula When the grid frequency deviation is ≥0.1Hz, the system responds within seconds and suppresses frequency fluctuation to ≤0.05Hz; the peak load regulation reliability is improved: the risk of load shedding caused by response delay in traditional pumped storage is reduced by more than 50%.

[0099] In the present invention, through the coupling of geothermal staged power generation, pumped storage peak regulation and waste heat cascade utilization, the three-level conversion of thermal energy-electrical energy-potential energy is realized, and the comprehensive energy efficiency is improved to ≥88%, which is a significant improvement over the traditional pumped storage system (70%-80%).

[0100] This application integrates CO2 capture and mineralization storage technology. The carbon intensity of the system throughout its life cycle is ≤0.03kgCO2 / kWh, directly supporting the carbon neutrality goal.

[0101] This application is based on LSTM-Attention prediction and NSGA-III multi-objective optimization algorithm to achieve second-level response (delay ≤ 200ms), taking into account both economic benefits and low-carbon operation.

[0102] (6) Net carbon removal calculation unit

[0103] The carbon net removal calculation unit is used to calculate the carbon net removal amount according to the geothermal fluid flow rate Q 地热 (t) and CO2 concentration Calculate the theoretical value of instantaneous carbon emissions

[0104]

[0105] in: is the CO2 density; t1 and t2 are the starting and ending times of the calculation interval;

[0106] Then, through the blockchain smart contract and storage volume Q 封存 Compare and generate net carbon removals and issue tradable certificates.

[0107] (7) Hybrid Energy Storage Coordination Control Unit

[0108] The hybrid energy storage coordination control unit includes a lithium-ion battery pack and supercapacitors, and allocates energy storage output through the following optimization model:

[0109] min(ω1·C 损耗 +ω2·|P 需求 -P 出力 |)

[0110] Constraints:

[0111]

[0112] Among them: ω1, ω2 are weight coefficients; C 损耗 is the loss cost of the hybrid energy storage system, including the energy loss cost of lithium-ion battery packs and supercapacitors; P 需求 P is the power requirement of the hybrid energy storage system to meet the total power load; 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 supercapacitor; SOC 电池 The state of charge of the lithium-ion battery pack is the ratio of the current battery charge to the rated capacity. 电容 is the supercapacitor temperature.

[0113] (8) Ecological security monitoring module

[0114] The ecological security monitoring module includes a water quality sensor, a soil moisture probe, and a biodiversity camera terminal, which dynamically adjusts operating parameters to meet the following requirements:

[0115] a: Dissolved oxygen downstream of the reservoir ≥ 5 mg / L; b: Fluctuation of pH value of surrounding soil ≤ ± 0.5; c: Heat emission temperature in the endangered species activity area ≤ 30°C;

[0116] If any indicator exceeds the limit, the ORC generator set will automatically reduce its power generation load or the pumped storage unit will be limited in its pumped storage power until the ecological parameters return to the safety threshold.

[0117] The present invention also provides a carbon-neutral energy supply method for cascade utilization of a pumped storage power station and geothermal energy, comprising the following steps:

[0118] A geothermal staged power generation unit is used for geothermal staged power generation; specifically, the geothermal staged power generation unit includes a high-temperature geothermal well, a medium-low temperature geothermal well, 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;

[0119] A 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 utilizes the surplus power generated by the geothermal staged power generation unit and the surplus power of the power grid to pump and store water during off-peak periods of the power grid, and releases water from the upper reservoir to the lower reservoir to generate electricity during peak periods;

[0120] A waste heat-potential energy coupling unit is used to couple the waste heat of geothermal tailwater with 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 generates electricity using the waste heat of the geothermal tailwater of the geothermal staged power generation unit, and the waste heat from power generation is stored in the phase change heat storage tank. The heat pump is used to provide anti-freeze preheating for the pumped storage pipeline of the pumped storage unit.

[0121] A carbon cycle management unit is used to capture geothermal tail gas and separate CO2, which is then mineralized and stored. Specifically, the carbon cycle management unit includes a geothermal fluid CO2 separation device, a mineralized storage well, and a carbon sink monitoring terminal. The geothermal fluid CO2 separation device uses an amine liquid-membrane separation composite process to capture the geothermal tail gas of the geothermal staged power generation unit and separate the CO2. The mineralized storage well utilizes the water pressure of the lower reservoir of the pumped storage unit to inject the separated CO2 into the basalt layer for mineralization. The carbon sink monitoring terminal is used to monitor the carbon sink of the geothermal tail gas after it has been treated by the geothermal fluid CO2 separation device.

[0122] An intelligent collaborative control 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 control unit is deployed on the edge computing node, and includes a prediction layer, an optimization layer and a control layer; the prediction layer is used to predict the grid load and the geothermal output of the geothermal staged power generation unit in the next 12 hours; the optimization layer is used to establish an objective function with 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 results of the prediction layer and the objective function of the optimization layer, so that the system's comprehensive energy efficiency and full life cycle carbon emission intensity meet the set targets.

[0123] The carbon-neutral energy supply system and method for cascade utilization of pumped storage power stations and geothermal energy provided by the present invention have the following advantages:

[0124] Through the three-in-one architecture of "multi-energy cascade utilization-carbon closed-loop management-intelligent dynamic optimization", this invention has overcome the industry difficulties of traditional pumped storage's reliance on high-carbon electricity, low utilization of geothermal resources, and insufficient system flexibility, and achieved four breakthroughs in "energy efficiency, low-carbon operation, intelligent management and control, and diversified benefits", providing a replicable and popularizable carbon neutral solution for building a new power system.

[0125] While embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions, and variations may be made to these embodiments without departing from the principles and spirit of the invention, and that the scope of the invention is defined by the appended claims and their equivalents.

Claims

1. A carbon-neutral energy supply system using a pumped storage power station and geothermal energy cascade, characterized in that: include: Geothermal hierarchical power generation unit, pumped storage unit, waste heat-potential energy coupling unit, carbon cycle management unit and intelligent coordinated control unit; The geothermal staged power generation unit comprises a high-temperature geothermal well, a medium-low temperature geothermal well, and a two-stage flash evaporation generator set; the two-stage flash evaporation generator set comprises 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; The pumped storage unit comprises a reversible pump-turbine, an upper reservoir and a lower reservoir; the reversible pump-turbine utilizes the surplus power generated by the geothermal staged power generation unit and the surplus power of the power grid to pump and store water during the off-peak period of the power grid, and releases water from the upper reservoir to the lower reservoir to generate electricity during the peak period; 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 waste heat of the geothermal tail water of the geothermal staged power generation unit to generate electricity, and the waste heat from power generation is stored in the phase-change heat storage tank. 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 includes a geothermal fluid CO2 separation device, a mineralized 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 CO2, and uses the mineralized storage well to utilize the water pressure of the lower reservoir of the pumped storage unit to inject the separated CO2 into the basalt layer for mineralization; 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; The intelligent collaborative control unit is deployed on the edge computing node and includes a prediction layer, an optimization layer and a control layer; the prediction layer is used to predict the grid load and the geothermal output of the geothermal staged power generation unit in the next 12 hours; the optimization layer is used to establish an objective function with 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 objective function of the optimization layer, so that the system's comprehensive energy efficiency and full life cycle carbon emission intensity meet the set targets.

2. A carbon-neutral energy supply system for cascade utilization of pumped storage power stations and geothermal energy according to claim 1, characterized in that: The exhaust pressure P of the second-stage steam turbine in the geothermal staged power generation unit is turbine The optimal evaporator pressure P of the ORC generator set with the waste heat-potential energy coupling unit ORC Satisfy the dynamic matching formula: P ORC =argminf[(η ORC (P,P turbine )-0.8·η ORC,max ) 2 +(P turbine -P-ΔP 安全 ) 2 ] Where: P ORC is the optimal pressure of the evaporator of the ORC generator set, is the optimization target; η ORC,max is the maximum theoretical efficiency of the ORC generator set, ΔP 安全 is the pressure safety margin threshold; P is the evaporator pressure of the ORC generator set; η ORC (P,P turbine ) is the pressure of the ORC generator set when the evaporator pressure is P and the exhaust pressure of the second-stage steam turbine is P turbine The actual efficiency under ; f[] represents the objective function.

3. A carbon-neutral energy supply system for cascade utilization of pumped storage power stations and geothermal energy according to claim 1, characterized in that: 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, pressure applied by the lower reservoir and the surface area of ​​rock fractures.

4. A carbon-neutral energy supply system for pumped storage power stations and cascade utilization of geothermal energy according to claim 1, characterized in that: In the waste heat-potential energy coupling unit, the heat energy release rate of the phase change heat storage tank is satisfy: Where: T 储热 is the time constant of the heat storage material. By optimizing the U·A value, the heat loss in the pipeline was reduced by 60%; U is the heat transfer coefficient, which represents the heat conduction efficiency between the material of the phase change heat storage tank and the pumped storage pipeline. A larger value indicates a stronger heat transfer capacity; A is the heat exchange area, which is the effective heat transfer area in contact between the phase change heat storage tank and the pumped storage pipeline; Tpipe is the real-time temperature of the pumped storage pipeline wall, which is the temperature of the outer wall of the pumped storage pipeline that needs to be preheated for antifreeze protection and is monitored in real time by a temperature sensor; t is the time variable.

5. A carbon-neutral energy supply system for pumped storage power stations and cascade utilization of geothermal energy according to claim 1, characterized in that: The prediction layer uses the LSTM-Attention neural network to predict the grid load and the geothermal output of the geothermal hierarchical power generation unit in the next 12 hours. The hidden state update formula is: h t =LSTM(x t ,h t-1 ),α t =softmax(W a [h t ;H history ]); 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 W is the encoding vector of the historical load sequence; a is the attention weight matrix; α t is the attention weight at time t.

6. A carbon-neutral energy supply system for cascade utilization of pumped storage power stations and geothermal energy according to claim 1, characterized in that: The multi-objective function F constructed by the optimization layer is: F=λ1f 收益 +λ2f 碳强度 Where: λ1 is the weight coefficient of the income target; λ2 is the weight coefficient of the carbon intensity target; f 收益 is the profit function, which represents the economic profit 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; 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 is the transaction price per unit carbon; E 地热 (t) is the geothermal power generation of the geothermal hierarchical power generation unit at time t; μ 地热 is the carbon emission coefficient of the geothermal hierarchical power generation unit, which is the theoretical value of carbon emissions per unit geothermal power generation; E 电网 (t) is the electric energy obtained from the grid at time t; μ 电网 is the carbon emission coefficient of the power grid, which is the theoretical value of carbon emissions per unit of power grid electricity; E 总输出 is the total power generation of the system.

7. A carbon-neutral energy supply system for cascade utilization of pumped storage power stations and geothermal energy according to claim 1, characterized in that: The control layer uses an improved NSGA-III algorithm to solve the Pareto front and dynamically allocate 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 uses the contemporary optimal solution as input and optimizes algorithm performance by enhancing population diversity and convergence speed; The control layer corrects the power of the pumped storage unit in real time according to the following rules: when the actual deviation of the grid frequency is ≥0.1 Hz, the power of the pumped storage unit is corrected using a PID adjustment mechanism based on the predicted frequency deviation and the actual deviation; in other cases, the predicted value is directly used.

8. The carbon-neutral energy supply system of pumped storage power station and geothermal energy cascade utilization according to claim 1 is characterized in that: Also includes: Net carbon removal calculation unit; The carbon net removal calculation unit is used to calculate the carbon net removal amount according to the geothermal fluid flow rate Q 地热 (t) and CO2 concentration Calculate the theoretical value of instantaneous carbon emissions in: is the CO2 density; t1 and t2 are the starting and ending times of the calculation interval; Then, through the blockchain smart contract and storage volume Q 封存 Comparison to generate net carbon removal.

9. The carbon-neutral energy supply system of pumped storage power station and geothermal energy cascade utilization according to claim 1 is characterized in that: Also includes: Hybrid energy storage coordination control unit; The hybrid energy storage coordination control unit includes a lithium-ion battery pack and supercapacitors, and allocates energy storage output through the following optimization model: min(ω1·C 损耗 +ω2·|P 需求 -P 出力 |) Constraints: Among them: ω1, ω2 are weight coefficients; C 损耗 is the loss cost of the hybrid energy storage system, including the energy loss cost of lithium-ion battery packs and supercapacitors; P 需求 P is the power requirement of the hybrid energy storage system to meet the total power load; 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 supercapacitor; SOC 电池 is the battery state of charge of the lithium-ion battery pack; T 电容 is the supercapacitor temperature; It also includes: an ecological security monitoring module; the ecological security monitoring module includes a water quality sensor, a soil moisture probe and a biodiversity camera terminal, and dynamically adjusts operating parameters to meet: a: Dissolved oxygen downstream of the reservoir ≥ 5 mg / L; b: Fluctuation of pH value of surrounding soil ≤ ± 0.5; c: Heat emission temperature in the endangered species activity area ≤ 30°C; If any indicator exceeds the limit, the ORC generator set will automatically reduce its power generation load or the pumped storage unit will be limited in its pumped storage power until the ecological parameters return to the safety threshold.

10. A method for a carbon-neutral energy supply system for a pumped storage power station and cascade utilization of geothermal energy according to any one of claims 1 to 9, characterized in that: The following steps are involved: A geothermal staged power generation unit is used for geothermal staged power generation; specifically, the geothermal staged power generation unit includes a high-temperature geothermal well, a medium-low temperature geothermal well, 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; A 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 utilizes the surplus power generated by the geothermal staged power generation unit and the surplus power of the power grid to pump and store water during off-peak periods of the power grid, and releases water from the upper reservoir to the lower reservoir to generate electricity during peak periods; A waste heat-potential energy coupling unit is used to couple the waste heat of geothermal tailwater with 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 generates electricity using the waste heat of the geothermal tailwater of the geothermal staged power generation unit, and the waste heat from power generation is stored in the phase change heat storage tank. The heat pump is used to provide anti-freeze preheating for the pumped storage pipeline of the pumped storage unit. A carbon cycle management unit is used to capture geothermal tail gas and separate CO2, which is then mineralized and stored. Specifically, the carbon cycle management unit includes a geothermal fluid CO2 separation device, a mineralized storage well, and a carbon sink monitoring terminal. The geothermal fluid CO2 separation device uses an amine liquid-membrane separation composite process to capture the geothermal tail gas of the geothermal staged power generation unit and separate the CO2. The mineralized storage well utilizes the water pressure of the lower reservoir of the pumped storage unit to inject the separated CO2 into the basalt layer for mineralization. The carbon sink monitoring terminal is used to monitor the carbon sink of the geothermal tail gas after it has been treated by the geothermal fluid CO2 separation device. An intelligent collaborative control 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 control unit is deployed on the edge computing node, and includes a prediction layer, an optimization layer and a control layer; the prediction layer is used to predict the grid load and the geothermal output of the geothermal staged power generation unit in the next 12 hours; the optimization layer is used to establish an objective function with 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 results of the prediction layer and the objective function of the optimization layer, so that the system's comprehensive energy efficiency and full life cycle carbon emission intensity meet the set targets.

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