Multi-energy complementary low-carbon heat supply system, device and method for salt lake lithium extraction demand

Abstract

The application discloses a multi-energy complementary low-carbon heat supply system, device and method for the demand of extracting lithium from salt lakes, and the method divides the multi-energy complementary green low-carbon heat supply system game architecture into two levels of master-slave games, the upper layer of the first level of master-slave games is a heat pump operator and a gas boiler operator in the middle layer of the game architecture, and the lower layer is a power grid and a natural gas operator in the bottom layer of the game architecture; the upper layer of the second level of master-slave games is a lithium carbonate manufacturer in the top layer of the game architecture, and the lower layer is the heat pump operator and the gas boiler operator in the middle layer of the game architecture for providing heat energy for users, and the multi-objective optimization of the heat pump equipment, the gas boiler and the water tank energy storage operator is included; the two levels of master-slave games are optimized and solved, and the decision scheme of each game participant can be obtained.

Description

Technical Field

[0001] This invention belongs to the field of refrigeration and heat pump technology, and relates to a multi-energy complementary low-carbon heating system, device and method for lithium extraction from salt lakes. Background Technology

[0002] With the rapid development of emerging industries such as electric vehicles, renewable energy, and energy storage technologies, all sectors are facing the crucial task of energy structure reform. Lithium batteries, as a core component of electric vehicles, smartphones, and energy storage systems, are experiencing explosive market growth, leading to a surge in demand for metallic lithium. Currently, approximately 80% of the world's lithium resources come from salt lakes. Salt lake lithium extraction technology can efficiently and cost-effectively extract lithium, helping to meet the rapidly growing demand. Traditional lithium ore extraction technologies generate large amounts of pollutants and wastewater, while salt lake lithium extraction technology reduces environmental pollution and is environmentally friendly, thus it has been applied in many regions worldwide.

[0003] Lithium extraction from salt lakes typically employs adsorption, a process that consumes large amounts of hot water at around 40°C. Traditional solutions, considering the generally remote locations of salt lakes, often utilize the direct combustion of liquefied natural gas to produce hot water. While this can meet heating demands, the energy efficiency of direct combustion of distributed primary energy sources is low, and the lack of post-treatment processes leads to pollutant emissions, making it uncompetitive in terms of both energy conservation and environmental protection. Summary of the Invention

[0004] The purpose of this invention is to overcome the shortcomings of the prior art and provide a multi-energy complementary low-carbon heating system, device and method for lithium extraction from salt lakes, so as to solve the problem of high energy consumption and environmental unfriendliness in the production process of lithium extraction from salt lakes in the prior art.

[0005] To achieve the above objectives, the present invention employs the following technical solution:

[0006] A multi-energy complementary low-carbon heating method for lithium extraction from salt lakes includes the following steps:

[0007] S1, Construct a game model, which includes a two-level master-slave game; initialize the game model parameters and generate an initial population of payoff factors;

[0008] The first-level master-slave game consists of heat pump operators and gas boiler operators at the top, and grid operators and natural gas operators at the bottom; the second-level master-slave game consists of lithium carbonate producers at the top, and heat pump operators, gas boiler operators and water tank energy storage operators at the bottom.

[0009] S2, in the lower layer of the first-level master-slave game, the power grid and natural gas operators receive the payoff factor population. Using a mixed-integer linear programming solver, under constraints, the optimization strategy is solved according to the objective functions of the power grid operators and natural gas operators, and the optimized payoff is retained. Based on the optimized payoff, the genetic algorithm population evolves to generate the first evolved payoff factor population. The first fitness function of the payoff factor population before evolution is compared with the first fitness function of the first evolved payoff factor population to obtain the optimal payoff factor population selected by the first-level master-slave game. The first fitness function is the objective function of the heat pump operator and the gas boiler operator in the upper layer of the first-level master-slave game.

[0010] S3: Based on the optimal payoff factor population selected in the first-level master-slave game, and according to the multi-objective functions of heat pump operators, gas boiler operators, and water tank energy storage operators in the lower layer of the second-level master-slave game, the transformed objective function is solved again using a mixed-integer linear programming solver, and the optimized payoff is retained. Based on the optimized payoff, the genetic algorithm population evolves to generate a second evolutionary payoff factor population. The second fitness function of the optimal payoff factor population selected in the first-level master-slave game and the second evolutionary payoff factor population are compared to obtain the optimal payoff factor population selected in the second-level master-slave game. The second fitness function is the objective function of the lithium carbonate producer in the upper layer of the second-level master-slave game.

[0011] The objective function of the heat pump operator aims to maximize net heat output revenue and minimize energy consumption; the objective function of the gas boiler operator aims to maximize net heat output revenue and minimize energy consumption; the objective function of the lithium carbonate producer aims to minimize total heat input expenditure and minimize energy consumption.

[0012] S4. Repeat S2 and S3 until the game in S2 and S3 reaches the convergence condition, obtain the final payoff factors and energy strategies, and determine the heating strategies of heat pump operators, gas boiler operators and water tank energy storage operators based on the energy strategies.

[0013] A further improvement of the present invention is that:

[0014] Preferably, the revenue factor population includes heat pump operator heat output revenue factor, gas boiler operator heat output revenue factor, water tank heat output revenue factor, grid operator electricity output revenue factor, and natural gas operator gas output revenue factor.

[0015] Preferably, in S2, the optimization strategy is solved by a mixed-integer linear programming solver to obtain the real-time optimal energy allocation strategy.

[0016] Preferably, in S2, the objective function of the power grid operator is to maximize the revenue from electricity output, and the objective function of the natural gas operator is to maximize the revenue from gas output.

[0017] Preferably, in S2, in the first-level master-slave game, the heat pump operator and the gas boiler operator adjust the input electrical power according to the power output revenue factor of the grid operator, and the gas boiler operator adjusts the input gas volume according to the gas output revenue factor; the grid operator adjusts the power output revenue factor according to the adjusted output electrical power, and the natural gas operator adjusts the gas output revenue factor according to the adjusted output gas volume; in S3, in the second-level master-slave game, the lithium carbonate producer adjusts the input thermal power according to the thermal output revenue factors of the heat pump, gas boiler, and water tank energy storage operators respectively; the heat pump, gas boiler, and water tank energy storage operators receive the thermal power adjusted by the lithium carbonate producer and adjust the thermal output revenue factor again, forming a game relationship.

[0018] Preferably, in S3, for multi-objective functions, the transformation is performed using the entropy weight normalization method, and the transformed objective function is solved using a mixed-integer linear programming solver to obtain the real-time optimal energy allocation strategy.

[0019] Preferably, in S4, when the game reaches the convergence condition, the objective functions of the lithium carbonate producer, heat pump operator, gas boiler operator, water tank energy storage operator, grid operator, and natural gas operator are equal to their respective objective functions in the previous iteration.

[0020] Multi-energy complementary low-carbon heating devices for lithium extraction from salt lakes include:

[0021] An initialization unit is used to construct a game model, which includes a two-level master-slave game; initialize game model parameters and generate an initial payoff factor population; the upper level of the first-level master-slave game consists of heat pump operators and gas boiler operators, and the lower level consists of grid operators and natural gas operators; the upper level of the second-level master-slave game consists of lithium carbonate producers, and the lower level consists of heat pump operators, gas boiler operators and water tank energy storage operators.

[0022] The first-level game unit is used by the power grid and natural gas operators in the lower layer of the first-level master-slave game to receive the payoff factor population. Using a mixed-integer linear programming solver, under constraints, it solves the optimization strategy according to the objective functions of the power grid operators and natural gas operators, and retains the optimized payoff. Based on the optimized payoff, the genetic algorithm population evolves to generate the first evolved payoff factor population. The first fitness function of the payoff factor population before evolution is compared with the first fitness function of the first evolved payoff factor population to obtain the optimal payoff factor population selected by the first-level master-slave game. The first fitness function is the objective function of the heat pump operator and the gas boiler operator in the upper layer of the first-level master-slave game.

[0023] The second-level game unit is used to optimize the population of optimal payoff factors selected from the first-level master-slave game. Based on the multi-objective functions of heat pump operators, gas boiler operators, and water tank energy storage operators in the lower layer of the second-level master-slave game, a mixed-integer linear programming solver is used to solve the optimization strategy again for the transformed objective function, retaining the optimized payoff. Based on the optimized payoff, a genetic algorithm population evolves to generate a second-evolutionary payoff factor population. The second fitness function of the optimal payoff factor population selected from the first-level master-slave game and the second-evolutionary payoff factor population are compared to obtain the optimal payoff factor population selected from the second-level master-slave game. The second fitness function is the objective function of the lithium carbonate producer in the upper layer of the second-level master-slave game.

[0024] The objective function of the heat pump operator aims to maximize net heat output revenue and minimize energy consumption; the objective function of the gas boiler operator aims to maximize net heat output revenue and minimize energy consumption; the objective function of the lithium carbonate producer aims to minimize total heat input expenditure and minimize energy consumption.

[0025] The equilibrium unit is used to repeat the first-level game unit and the second-level game unit until the game of the first-level game unit and the second-level game unit both reach the convergence condition, and obtain the final payoff factors and energy strategies. Based on the energy strategies, the heating strategies of heat pump operators, gas boiler operators and water tank energy storage operators are determined.

[0026] Preferably, it includes a battery-grade lithium carbonate preparation unit, wherein the outlets of two cold demineralized water pipelines of the battery-grade lithium carbonate preparation unit are connected to the inlet of a hot water tank unit, and the outlet of the demineralized water pipeline of the hot water tank unit is connected to the inlet of the battery-grade lithium carbonate preparation unit; the demineralized water in the two cold demineralized water pipelines has a different temperature.

[0027] The low-temperature medium water outlet of the hot water tank is connected to the low-temperature medium water inlet of several heat pump units, and the high-temperature medium water outlet of several heat pump units is connected to the high-temperature medium water inlet of the hot water tank.

[0028] The medium water is heated and demineralized in the hot water tank unit.

[0029] Preferably, it also includes a gas-fired boiler unit connected to the lithium carbonate production unit.

[0030] Compared with the prior art, the present invention has the following beneficial effects:

[0031] This invention discloses a multi-energy complementary low-carbon heating method for lithium extraction from salt lakes. This method divides the game architecture of the multi-energy complementary green low-carbon heating system into a two-level master-slave game. The first-level master-slave game consists of heat pump operators and gas boiler operators in the middle layer of the game architecture, and power grid and natural gas operators at the bottom layer. The second-level master-slave game consists of lithium carbonate producers at the top layer of the game architecture, and heat pump operators and gas boiler operators providing heat energy to users in the middle layer, encompassing multiple optimization objectives for heat pump equipment, gas boilers, and water tank energy storage operators. Optimizing and solving the two-level master-slave game yields the decision schemes of each game participant. A creative game-theoretic method for setting up a multi-energy complementary green low-carbon heating system to meet the demand for lithium extraction from salt lakes is proposed. This method reduces energy consumer expenditures in complex energy networks and increases the net benefits of energy producers, consumers, and transporters. Specifically, it reduces energy expenditures for lithium carbonate production, increases the net benefits of heat pumps and gas boilers, and simultaneously considers the benefits of multiple operators supplying energy to lithium carbonate production. Overall, this improves the efficiency of individual multi-energy complementary green low-carbon heating systems and reduces energy consumption.

[0032] This invention discloses a multi-energy complementary low-carbon heating system for lithium extraction from salt lakes. The system employs a transcritical CO2 air-source heat pump unit and two transcritical CO2 water-source heat pump systems, achieving a heat-to-electricity ratio of 300%–600%, demonstrating significant energy-saving advantages. This system utilizes heat pump technology as the optimal solution for replacing end-point electricity in multiple industrial sectors. It can use air, soil, or waste heat from industrial wastewater as heat sources, providing a large amount of heat energy at different temperature ranges to various industrial scenarios and needs with minimal electricity consumption. Considering the complexity of the lithium extraction process from salt lakes and the availability of multiple waste heat sources in industrial settings, including ground-source, air-source, and waste water-source heat pump technologies, this system is expected to become one of the main energy-saving and emission-reduction technologies for future lithium extraction from salt lakes, possessing significant academic and engineering practical value. Attached Figure Description

[0033] Figure 1 This is a flowchart of the multi-energy complementary green and low-carbon heating system for lithium extraction from salt lakes according to the present invention (heat pump part only);

[0034] Figure 2 This is a diagram showing the game hierarchy of the multi-energy complementary green low-carbon heating system of the present invention.

[0035] Figure 3 The flowchart shows the game optimization algorithm for the multi-energy complementary green low-carbon heating system of the present invention.

[0036] Among them, 1 is the battery-grade lithium carbonate preparation unit; 2 is the transcritical CO2 air source heat pump unit; 3 is the concentrated liquid water source heat pump unit; 4 is the old brine water source heat pump unit; and 5 is the hot water tank unit.

[0037] 11 is the carnallite preparation unit; 12 is the adsorption tower; 21 is the first transcritical CO2 compressor; 22 is the first gas cooler; 23 is the first throttle valve; 24 is the air heat source evaporator; 31 is the second transcritical CO2 compressor; 32 is the second gas cooler; 33 is the second throttle valve; 34 is the concentrate heat source evaporator; 41 is the third transcritical CO2 compressor; 42 is the third gas cooler; 43 is the third throttle valve; 44 is the old brine heat source evaporator. Detailed Implementation

[0038] The present invention will now be described in further detail with reference to the accompanying drawings:

[0039] In the description of this invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention. The terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance. Furthermore, unless otherwise explicitly specified and limited, the terms "installed," "connected," and "linked" should be interpreted broadly. For example, they can refer to a fixed connection or a detachable connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal connection of two elements. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0040] See Figure 1 The present invention discloses a multi-energy complementary green and low-carbon heating system for lithium extraction from salt lakes. The system includes a battery-grade lithium carbonate preparation unit 1, a transcritical CO2 air source heat pump unit 2, two transcritical CO2 water source heat pump systems and a hot water tank 5. The two transcritical CO2 water source heat pump systems are a concentrated liquid water source heat pump 3 and an old brine water source heat pump 4.

[0041] The battery-grade lithium carbonate preparation unit 1 includes a carnallite preparation unit 11 and an adsorption tower 12. The old brine pipeline of the carnallite preparation unit 11 is connected to the old brine inlet pipeline of the adsorption tower 12. The carnallite preparation unit 11 transfers the old brine to the adsorption tower 12, and the adsorption tower 12 prepares lithium carbonate through the old brine and heated demineralized water. The adsorption tower 12 is equipped with four liquid outlets: a hot demineralized water outlet at 30-35℃, a cold demineralized water outlet at 10-25℃, a concentrated liquid outlet at 25℃, and an old brine outlet at 10℃. The cold demineralized water outlets at 30-35℃ and 10-25℃ are both connected to the hot water tank unit 5. The low-temperature medium water outlet of the hot water tank unit 5 is connected to the transcritical CO2 air source heat pump unit 2, the concentrated liquid water source heat pump 3, and the old brine water source heat pump 4. The hot water tank unit 5 is equipped with a high-temperature return water tank for inputting the heated medium water into the hot water tank unit 5. After heat exchange between the medium water and the demineralized water, the demineralized water is heated to 40℃ in the hot water tank unit 5. The demineralized water outlet of the hot water tank unit 5 is connected to the adsorption tower 12.

[0042] The transcritical CO2 air source heat pump unit 2 includes a first transcritical CO2 compressor 21, a first gas cooler 22, a first throttle valve 23, and an air heat source evaporator 24. The air heat source evaporator 24 absorbs heat from the air and transfers the heat to the refrigerant flowing through it. The refrigerant is compressed in the first transcritical CO2 compressor 21. The compressed refrigerant heats the medium water output from the hot water tank unit 5 in the first gas cooler 22. After releasing energy, it returns to the evaporator 24 for circulation via the first throttle valve 23. The low-temperature water medium discharged from the hot water tank unit 5 is heated in the first gas cooler 22 to become high-temperature water medium and flows back to the hot water tank unit 5.

[0043] The concentrated liquid water source heat pump 3 includes a second transcritical CO2 compressor 31, a second gas cooler 32, a throttling valve 33, and a concentrated liquid heat source evaporator 34. After the refrigerant flows out from the second throttling valve 33, it absorbs heat from the concentrated liquid in the concentrated liquid heat source evaporator 34. After being compressed in the second transcritical CO2 compressor 31, the refrigerant enters the second gas cooler 32 and exchanges heat with the low-temperature medium water. After releasing heat, the refrigerant returns to the concentrated liquid heat source evaporator 34 via the second throttling valve 33. The low-temperature medium water 32 is heated to high-temperature medium water in the second gas cooler 32 and flows back to the hot water tank unit 5.

[0044] The old brine water source heat pump 4 includes a third gas cooler 42, a third throttling valve 43, and an old brine heat source evaporator 44. After the refrigerant flows out from the third throttling valve 43, it absorbs heat from the waste old brine in the old brine heat source evaporator 44. The refrigerant that has absorbed heat is compressed in the third transcritical CO2 compressor 41, and then exchanges heat with low-temperature medium water in the third gas cooler 42 to obtain high-temperature return water, which is then introduced into the hot water tank 5. The refrigerant that releases heat returns to the old brine heat source evaporator 44 via the third throttling valve 43.

[0045] The above process results in the high-temperature medium water inlet of hot water tank unit 5 originating from three heat pump units.

[0046] The adsorption tower 12 is also connected to a gas-fired boiler unit. When the heat provided by the transcritical CO2 air source heat pump unit 2 and the two transcritical CO2 water source heat pump units cannot meet the heat demand of the adsorption tower, the gas-fired boiler needs to heat the medium water to supplement the adsorption tower 12.

[0047] On the gas cooler side of the transcritical CO2 air source heat pump, low-temperature inlet water from the hot water tank exchanges heat with high-temperature CO2 in the gas cooler, and is heated to high-temperature return water before returning to the hot water tank. The function of the high-temperature side of the transcritical CO2 water source heat pump system is the same as that of the air source heat pump. In transcritical CO2 water source heat pump system 1, low-temperature CO2 in the evaporator exchanges heat with concentrated liquid from the adsorption tower, and the concentrated liquid is discharged after being cooled; in transcritical CO2 water source heat pump system 2, low-temperature CO2 in the evaporator exchanges heat with old brine from the adsorption tower, and the old brine is cooled before being discharged. When the heat supply of the heat pump system is insufficient, it can be supplemented by a gas boiler.

[0048] The combination of air source and water source heat pump described above is only one feasible embodiment of the present invention and is not intended to limit the present invention. In fact, any ground source, sewage source, waste heat source heat pump, etc. can be considered for implementation as appropriate and should be included within the protection scope of the present invention.

[0049] See Figure 2This invention proposes a game-theoretic hierarchy setting method for a multi-energy complementary green low-carbon heating system, comprising: a battery-grade lithium carbonate production energy-consuming end; heating equipment (including a transcritical CO2 air-source heat pump unit 2, a concentrated liquid water-source heat pump 3, an old brine water-source heat pump 4, and a gas-fired boiler); the three heat pump units (including the transcritical CO2 air-source heat pump unit 2, the concentrated liquid water-source heat pump 3, and the old brine water-source heat pump 4) convert electrical energy into heat energy; and the gas-fired boiler converts the chemical energy of natural gas into heat energy. In the electrothermal coupling relationship and the natural gas thermal coupling relationship, the electrical load and natural gas load change with variations in the lithium extraction heat load from the salt lake, operating conditions, etc.; the three heat pump units and the gas-fired boiler interact with the power grid and natural gas operators, drawing electricity from the grid or obtaining natural gas; for a single system, the user is the lithium extraction equipment from the salt lake, and the heat pump equipment and the gas-fired boiler are energy producers and consumers (thermal energy production and electrification). The system is structured as follows: For lithium extraction equipment, three heat pump units and the energy storage device (heat tank unit 5) supply heat energy, acting as energy producers. A three-tiered game theory framework is constructed based on a single multi-energy complementary green low-carbon heating system. The participants include lithium carbonate producers, water tank operators, heating equipment operators, and grid and natural gas operators. The top tier of the game theory framework consists of lithium carbonate producers; the middle tier comprises operators providing energy to lithium carbonate production, including heat pump operators, gas boiler operators, and water tank energy storage operators; and the bottom tier consists of grid and natural gas operators. Grid operators set electricity output revenue factors, natural gas operators set gas output revenue factors, and heat pump operators, gas boiler operators, and water tank energy storage operators each set their own heat output revenue factors.

[0050] See Figure 3 This invention discloses a multi-objective game optimization control method and an optimization solution method for multi-level, multi-objective games, including:

[0051] S1, Input system initialization parameters, randomly generate an initial population of revenue factors, which includes the electricity output revenue factor, gas output revenue factor and heat output revenue factor of each operator.

[0052] S2, the power grid and natural gas operators in the lower level of the first-level master-slave game receive the payoff factor population. Using a mixed-integer linear programming solver, under constraints, the optimization strategy is solved according to the objective function of the power grid operator and the natural gas operator, and the optimization payoff is retained.

[0053] Based on optimized returns, the genetic algorithm population evolution generates new electricity output return factors, gas output return factors, and heat output return factors, namely the first evolved return factor population. The first fitness function is calculated, which is the objective function of the heat pump and gas boiler operators in the first-level master-slave game. According to the fitness function before and after the evolution of the return factor population, the better population is selected from the return factor population before or after the evolution. The optimal population is the return factor population that is more beneficial to the operators with higher importance levels. The optimal return factor population selected in the first master-slave game is obtained.

[0054] In the first level of the master-slave game, the heat pump operator adjusts the input electrical power based on the power output revenue factor of the grid operator, and the gas boiler operator adjusts the input gas volume based on the gas output revenue factor of the natural gas operator. The grid operator and the natural gas operator adjust their revenue factors again upon receiving the adjusted electrical power from the heat pump or the adjusted natural gas volume from the gas boiler, thus forming a game relationship.

[0055] S3, the optimal payoff factor population selected by the first-level master-slave game is passed to the second-level master-slave game. For the multi-objective function of multiple operators in the lower level of the second-level master-slave game, the entropy weight normalization method is used to transform it. The transformed objective function is optimized again by a mixed integer linear programming solver, and the current payoff is retained.

[0056] Based on the optimized returns, new electricity output return factors, gas output return factors, and heat output return factors are generated again, which are the second evolutionary return factor population. The second fitness function of the optimal return factor population in the first-level master-slave game and the second evolutionary return factor population is calculated and compared. The second fitness function is the objective function of the upper-level user aggregation quotient in the second-level master-slave game. The population before or after evolution is selected again.

[0057] In the second-level master-slave game, the lithium carbonate producer adjusts the input heat power according to the heat output revenue factors of the heat pump, gas boiler, and water tank energy storage operators respectively; the heat pump, gas boiler, and water tank energy storage operators receive the adjusted heat power from the lithium carbonate producer and then adjust the heat output revenue factors again, thus forming a game relationship.

[0058] S4. If the entire game reaches the convergence condition, that is, the objective function values ​​of each player in the previous two iterations are less than the convergence error, then the solution is completed, and the final payoff factor and energy strategy are determined. Otherwise, continue to repeat steps 2 and 3 for iterative calculation.

[0059] In some embodiments of the present invention, the game strategy set is {electricity output revenue factor of grid operator, gas output revenue factor of natural gas operator, heat output revenue factor of each heat pump operator, heat output revenue factor of gas boiler operator, heat output revenue factor of water tank energy storage operator, water tank charging power, electricity extraction power of each heat pump, gas extraction power of gas boiler, heat extraction power of lithium carbonate producer from heat pump and gas boiler, heat extraction power of lithium carbonate producer from water tank};

[0060] System parameter initialization includes parameters such as user initial heat load, genetic population size, population mutation rate, crossover probability, and game convergence error;

[0061] In some embodiments of the present invention, in S2 and S3, the objectives of the game participants in the multi-energy complementary green low-carbon heating system include:

[0062] Grid operators output electrical energy and aim to maximize profits; their objective function is maxC. grid,e ;

[0063]

[0064] Natural gas operators output gas and aim to maximize profits; their objective function is maxC. grid,g :

[0065]

[0066] The objective functions of each heat pump operator (including air source heat pumps, No. 1 medium-temperature water source heat pump, and No. 2 high-temperature water source heat pump) include the heat energy revenue generated from the output to battery-grade lithium carbonate manufacturers and water tank operators, the cost of obtaining electricity from the grid operator, and the operation and maintenance costs of the heat pumps. Ultimately, they aim to maximize net revenue and minimize energy consumption. The objective functions for each are maxC. ashp maxC wshp1 maxC wshp2 :

[0067]

[0068]

[0069]

[0070] The objective function of a gas-fired boiler operator includes the heat revenue generated from supplying battery-grade lithium carbonate manufacturers and water tank operators, the cost of obtaining natural gas from natural gas operators, and the operation and maintenance costs of the gas-fired boiler. Ultimately, it aims to maximize net revenue and minimize energy consumption. Its objective function is maxC. boil :

[0071]

[0072] Water tank operators acquire heat energy from various heating equipment operators and then supply that heat energy to battery-grade lithium carbonate manufacturers, aiming to maximize net profit. Their objective function is maxC. tk :

[0073]

[0074] Battery-grade lithium carbonate equipment operators obtain heat energy from heat pump operators, gas boiler operators, and water tank operators, aiming to minimize total expenditure, which in this game also means minimizing energy consumption. Their objective function is minC. lc :

[0075]

[0076] The multi-level, multi-objective game-theoretic optimization control method for the multi-energy complementary green low-carbon heating system is characterized in that the game solution must satisfy constraints, which include:

[0077] The capacity of the water tank is limited by both upper and lower limits:

[0078]

[0079] Heat pumps and boilers are limited by their rated capacity and energy efficiency ratio:

[0080]

[0081] Electrical balance:

[0082]

[0083] Thermal equilibrium:

[0084]

[0085] Gas balance:

[0086]

[0087] The glossary of technical terms used in the formula is as follows:

[0088]

[0089]

[0090] The entropy weight normalization transformation process for the multi-objective function in the second-level master-slave game includes:

[0091] The second-level master-slave game involves five participants: an air source heat pump, a No. 1 water source heat pump, a No. 2 water source heat pump, a gas boiler, and a water tank energy storage operator. There are m objective functions (m=5). The system is run n times randomly, yielding n sets of data for the objective functions. Each objective function is represented as a matrix C.

[0092]

[0093] The objective functions of the above operators are all benefit-oriented objective functions; the larger the objective function value, the better. These are extremely large evaluation indicators. Matrix C is normalized using the following formula to obtain a normalized matrix, where the elements are x. ij Calculate the information entropy S j With weighting coefficient w j :

[0094]

[0095] The original multi-objective function C j The multi-objective function F, after normalization and entropy weighting transformation of (j∈{air source heat pump operator, No. 1 water source heat pump operator, No. 2 water source heat pump operator, gas boiler operator, water tank energy storage operator}), is expressed as:

[0096]

[0097] In some embodiments of the present invention, the method for determining game equilibrium and convergence in the optimization solution is as follows:

[0098] When the game reaches equilibrium, the objective functions of lithium carbonate producers, heat pump operators, gas boiler operators, water tank energy storage operators, grid operators, and natural gas operators are equal to the objective function of the previous iteration:

[0099]

[0100] For ease of calculation during optimization, the game is considered to reach equilibrium when the following convergence conditions are met:

[0101]

[0102] In the formula: ε is the convergence error.

[0103] This invention also discloses a multi-energy complementary low-carbon heating device for lithium extraction from salt lakes, comprising:

[0104] An initialization unit is used to construct a game model, which includes a two-level master-slave game; initialize game model parameters and generate an initial payoff factor population; the upper level of the first-level master-slave game consists of heat pump operators and gas boiler operators, and the lower level consists of grid operators and natural gas operators; the upper level of the second-level master-slave game consists of lithium carbonate producers, and the lower level consists of heat pump operators, gas boiler operators and water tank energy storage operators.

[0105] The first-level game unit is used by the power grid and natural gas operators in the lower layer of the first-level master-slave game to receive the payoff factor population. Using a mixed-integer linear programming solver, under constraints, it solves the optimization strategy according to the objective functions of the power grid operators and natural gas operators, and retains the optimized payoff. Based on the optimized payoff, the genetic algorithm population evolves to generate the first evolved payoff factor population. The first fitness function of the payoff factor population before evolution is compared with the first fitness function of the first evolved payoff factor population to obtain the optimal payoff factor population selected by the first-level master-slave game. The first fitness function is the objective function of the heat pump operator and the gas boiler operator in the upper layer of the first-level master-slave game.

[0106] The second-level game unit is used to optimize the population of optimal payoff factors selected from the first-level master-slave game. Based on the multi-objective functions of heat pump operators, gas boiler operators, and water tank energy storage operators in the lower layer of the second-level master-slave game, a mixed-integer linear programming solver is used to solve the optimization strategy again for the transformed objective function, retaining the optimized payoff. Based on the optimized payoff, a genetic algorithm population evolves to generate a second-evolutionary payoff factor population. The second fitness function of the optimal payoff factor population selected from the first-level master-slave game and the second-evolutionary payoff factor population are compared to obtain the optimal payoff factor population selected from the second-level master-slave game. The second fitness function is the objective function of the lithium carbonate producer in the upper layer of the second-level master-slave game.

[0107] The objective function of the heat pump operator aims to maximize net heat output revenue and minimize energy consumption; the objective function of the gas boiler operator aims to maximize net heat output revenue and minimize energy consumption; the objective function of the lithium carbonate producer aims to minimize total heat input expenditure and minimize energy consumption.

[0108] The equilibrium unit is used to repeat the first-level game unit and the second-level game unit until the game of the first-level game unit and the second-level game unit both reach the convergence condition, and obtain the final payoff factors and energy strategies. Based on the energy strategies, the heating strategies of heat pump operators, gas boiler operators and water tank energy storage operators are determined.

[0109] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A multi-energy complementary low-carbon heating method for lithium extraction from salt lakes, characterized in that: Includes the following steps: S1, Construct a game model, which includes a two-level master-slave game; initialize the game model parameters and generate an initial population of payoff factors; The first level of the master-slave game consists of heat pump operators and gas boiler operators at the top, and power grid operators and natural gas operators at the bottom. The second-level master-slave game consists of lithium carbonate producers at the top and heat pump operators, gas boiler operators, and water tank energy storage operators at the bottom. S2, in the lower layer of the first-level master-slave game, the power grid and natural gas operators receive the payoff factor population. Using a mixed-integer linear programming solver, under constraints, the optimization strategy is solved according to the objective functions of the power grid operators and natural gas operators, and the optimized payoff is retained. Based on the optimized payoff, the genetic algorithm population evolves to generate the first evolved payoff factor population. The first fitness function of the payoff factor population before evolution is compared with the first fitness function of the first evolved payoff factor population to obtain the optimal payoff factor population selected by the first-level master-slave game. The first fitness function is the objective function of the heat pump operator and the gas boiler operator in the upper layer of the first-level master-slave game. S3: Based on the optimal payoff factor population selected in the first-level master-slave game, and according to the multi-objective functions of heat pump operators, gas boiler operators, and water tank energy storage operators in the lower layer of the second-level master-slave game, the transformed objective function is solved again using a mixed-integer linear programming solver, and the optimized payoff is retained. Based on the optimized payoff, the genetic algorithm population evolves to generate a second evolutionary payoff factor population. The second fitness function of the optimal payoff factor population selected in the first-level master-slave game and the second evolutionary payoff factor population are compared to obtain the optimal payoff factor population selected in the second-level master-slave game. The second fitness function is the objective function of the lithium carbonate producer in the upper layer of the second-level master-slave game. The objective function of the heat pump operator aims to maximize net heat output revenue and minimize energy consumption; the objective function of the gas boiler operator aims to maximize net heat output revenue and minimize energy consumption; the objective function of the lithium carbonate producer aims to minimize total heat input expenditure and minimize energy consumption. S4. Repeat S2 and S3 until the game in S2 and S3 reaches the convergence condition, obtain the final payoff factors and energy strategies, and determine the heating strategies of heat pump operators, gas boiler operators and water tank energy storage operators based on the energy strategies.

2. The multi-energy complementary low-carbon heating method for lithium extraction from salt lakes according to claim 1, characterized in that, The revenue factor population includes heat pump operators' heat output revenue factors, gas boiler operators' heat output revenue factors, water tank operators' heat output revenue factors, grid operators' electricity output revenue factors, and natural gas operators' gas output revenue factors.

3. The multi-energy complementary low-carbon heating method for lithium extraction from salt lakes according to claim 1, characterized in that, In S2, the optimization strategy is solved by a mixed-integer linear programming solver to obtain the real-time optimal energy allocation strategy.

4. The multi-energy complementary low-carbon heating method for lithium extraction from salt lakes according to claim 1, characterized in that, In S2, the objective function of the power grid operator is to maximize the revenue from electricity output, while the objective function of the natural gas operator is to maximize the revenue from gas output.

5. The multi-energy complementary low-carbon heating method for lithium extraction from salt lakes according to claim 1, characterized in that, In S2, in the first-level master-slave game, the heat pump operator and the gas boiler operator adjust the input power according to the power output revenue factor of the grid operator, and the gas boiler operator adjusts the input gas volume according to the gas output revenue factor. The grid operator adjusts the electricity output revenue factor based on the adjusted output power, and the natural gas operator adjusts the gas output revenue factor based on the adjusted output gas volume. In S3, in the second-level master-slave game, the lithium carbonate producer adjusts the input heat power based on the heat output revenue factors of the heat pump, gas boiler, and water tank energy storage operators respectively. The heat pump, gas boiler, and water tank energy storage operators receive the heat power adjusted by the lithium carbonate producer and adjust their heat output revenue factors again, forming a game relationship.

6. The multi-energy complementary low-carbon heating method for lithium extraction from salt lakes according to claim 1, characterized in that, In S3, for multi-objective functions, the entropy weight normalization method is used to transform them, and the transformed objective functions are solved using a mixed-integer linear programming solver to obtain the real-time optimal energy allocation strategy.

7. The multi-energy complementary low-carbon heating method for lithium extraction from salt lakes according to claim 1, characterized in that, In S4, when the game reaches the convergence condition, the objective functions of the lithium carbonate producer, heat pump operator, gas boiler operator, water tank energy storage operator, grid operator, and natural gas operator are equal to their respective objective functions in the previous iteration.

8. A multi-energy complementary low-carbon heating device for lithium extraction from salt lakes, characterized in that: include: An initialization unit is used to construct a game model, which includes a two-level master-slave game; initialize game model parameters, and generate an initial population of payoff factors; The first-level master-slave game consists of heat pump operators and gas boiler operators at the top, and grid operators and natural gas operators at the bottom; the second-level master-slave game consists of lithium carbonate producers at the top, and heat pump operators, gas boiler operators and water tank energy storage operators at the bottom. The first-level game unit is used by the power grid and natural gas operators in the lower layer of the first-level master-slave game to receive the payoff factor population. Using a mixed-integer linear programming solver, under constraints, it solves the optimization strategy according to the objective functions of the power grid operators and natural gas operators, and retains the optimized payoff. Based on the optimized payoff, the genetic algorithm population evolves to generate the first evolved payoff factor population. The first fitness function of the payoff factor population before evolution is compared with the first fitness function of the first evolved payoff factor population to obtain the optimal payoff factor population selected by the first-level master-slave game. The first fitness function is the objective function of the heat pump operator and the gas boiler operator in the upper layer of the first-level master-slave game. The second-level game unit is used to optimize the population of optimal payoff factors selected from the first-level master-slave game. Based on the multi-objective functions of heat pump operators, gas boiler operators, and water tank energy storage operators in the lower layer of the second-level master-slave game, a mixed-integer linear programming solver is used to solve the optimization strategy again for the transformed objective function, retaining the optimized payoff. Based on the optimized payoff, a genetic algorithm population evolves to generate a second-evolutionary payoff factor population. The second fitness function of the optimal payoff factor population selected from the first-level master-slave game and the second-evolutionary payoff factor population are compared to obtain the optimal payoff factor population selected from the second-level master-slave game. The second fitness function is the objective function of the lithium carbonate producer in the upper layer of the second-level master-slave game. The objective function of the heat pump operator aims to maximize net heat output revenue and minimize energy consumption; the objective function of the gas boiler operator aims to maximize net heat output revenue and minimize energy consumption; the objective function of the lithium carbonate producer aims to minimize total heat input expenditure and minimize energy consumption. The equilibrium unit is used to repeat the first-level game unit and the second-level game unit until the game of the first-level game unit and the second-level game unit both reach the convergence condition, and obtain the final payoff factors and energy strategies. Based on the energy strategies, the heating strategies of heat pump operators, gas boiler operators and water tank energy storage operators are determined.

9. A multi-energy complementary low-carbon heating system for lithium extraction from salt lakes, applied to the multi-energy complementary low-carbon heating method for lithium extraction from salt lakes as described in any one of claims 1-7, characterized in that, The battery-grade lithium carbonate preparation unit (1) is included. The outlets of the two cold demineralized water pipelines of the battery-grade lithium carbonate preparation unit (1) are connected to the inlet of the hot water tank unit (5). The outlet of the demineralized water pipeline of the hot water tank unit (5) is connected to the inlet of the battery-grade lithium carbonate preparation unit (1). The demineralized water in the two cold demineralized water pipelines has different temperatures. The low-temperature medium water outlet of the hot water tank (5) is connected to the low-temperature medium water inlet of several heat pump units, and the high-temperature medium water outlet of several heat pump units is connected to the high-temperature medium water inlet of the hot water tank (5). The medium water is heated and demineralized in the hot water tank unit (5).

10. The multi-energy complementary low-carbon heating system for lithium extraction from salt lakes according to claim 9, characterized in that, It also includes a gas-fired boiler unit connected to the lithium carbonate preparation unit (1).

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