Ground source heat pump-central heating pipe network coupling system based on multi-energy complementation

Abstract

The invention relates to the technical field of heat supply energy, in particular to a ground source heat pump-central heating pipe network coupling system based on multi-energy complementation, which comprises a ground source heat pump subsystem, a central heating pipe network subsystem and an intelligent regulation and control center which are dynamically coupled through an energy exchange device comprising a phase change energy storage unit and a plate heat exchanger, the central heating pipe network subsystem is provided with a waste heat recovery device with a titanium-based spoiler and a time-sharing dispatching valve; an energy distribution model, a self-adaptive PID controller and an integrated digital twinning and fault diagnosis module are arranged in the intelligent regulation and control center. The system collects operation parameters through the intelligent regulation and control center, energy is dispatched with the lowest energy consumption and the heat demand meeting as targets, and multi-energy complementation is achieved through waste heat recovery and phase change energy storage. The system is high in utilization efficiency, accurate in control, high in reliability and suitable for residence communities, commercial complexes, industrial parks and other scenes, energy consumption can be reduced by 25%-30%, and the low-carbon heat supply requirement is met.

Description

Technical Field

[0001] This invention relates to the field of new energy technology in power systems, specifically to a ground source heat pump-central heating network coupling system based on multi-energy complementarity. Background Technology

[0002] With the increasing demand for global energy structure transformation and low-carbon development, heating systems, as core energy-consuming units in the building and industrial sectors, have seen their energy efficiency and operational stability become a focus of industry attention. Ground source heat pump technology, due to its ability to stably extract shallow geothermal energy and its clean and efficient characteristics, is widely used in residential, commercial, and industrial settings; while centralized heating network technology, with its advantages of large-scale energy supply, has become one of the mainstream methods for urban and industrial park heating. Currently, ground source heat pump systems mostly operate on a single energy source, relying on the stability of underground heat sources, and are prone to insufficient energy supply during periods of extreme low temperatures or high loads. While centralized heating networks can achieve large-scale heat transfer, their energy utilization efficiency is limited by issues such as network heat loss and insufficient waste heat recovery. Meanwhile, as user heating demands become increasingly diversified, such as peak morning and evening heating times in residential areas, multi-period load fluctuations in commercial complexes, and the need for constant temperature accuracy in industrial parks, the shortcomings of traditional heating technologies in terms of energy dispatch flexibility, system coordination, and fault response capabilities are becoming increasingly apparent. Specific deficiencies are as follows: (1) Insufficient energy synergy and significant limitations of a single system When existing ground source heat pump systems operate independently, they rely on variable frequency technology or auxiliary heat sources to cope with load fluctuations. In extreme low-temperature environments, the heat exchange efficiency of buried pipe heat exchangers decreases, and heat pump units need to operate at full load to meet heating demand, resulting in a significant increase in energy consumption. Meanwhile, centralized heating network systems mostly adopt a fixed energy supply mode, making it difficult to form energy complementarity with ground source heat pump systems. Furthermore, the waste heat generated in the network (such as heat dissipation during transportation and waste heat returning to the user end) lacks efficient recovery and utilization devices, resulting in a large amount of heat being wasted and failing to achieve synergistic optimization of different energy forms. (2) The operation and control accuracy is low, making it difficult to adapt to complex thermal demands. Traditional heating systems often employ conventional PID control, which can only adjust a single parameter (such as the supply and return water temperature difference). They lack energy allocation logic based on overall energy efficiency and cannot dynamically adjust the energy supply ratio of ground source heat pumps and centralized heating networks according to real-time user heat demand. In scenarios with large heat load fluctuations, "supply-demand mismatch" problems easily occur. For example, commercial complexes may experience insufficient energy supply during high daytime loads and energy waste during low nighttime loads. Furthermore, they cannot accurately meet the stringent temperature control requirements of industrial parks, with supply and return water temperature differences often fluctuating by more than ±3℃, impacting production or user experience. (3) The system has weak reliability and insufficient fault response capability. Existing ground source heat pump systems are prone to blockage of buried pipe heat exchangers due to soil impurities, lacking real-time monitoring and rapid diagnostic mechanisms. By the time a fault is detected, it has already caused significant power supply disruptions. Central heating networks rely heavily on manual or simple timing controls for valve regulation, which are susceptible to jamming under high pressure and high flow rate conditions, and the network suffers from high heat loss rates (exceeding 10% in some systems). Furthermore, traditional systems lack emergency energy storage devices, making it impossible to quickly replenish heat during extreme weather (such as prolonged low temperatures) or subsystem failures, easily leading to heating interruptions and compromising operational stability. (4) Poor scene adaptability, insufficient modularity and scalability Existing ground source heat pumps and centralized heating networks are mostly customized designs, with fixed equipment parameters configured for specific scenarios (such as residential or industrial). When the application scenario changes or the heat load scale is adjusted, the entire system needs to be reconstructed. For example, additional buried pipes are needed in cold regions, and high-pressure adapter components need to be replaced in industrial parks. This not only increases equipment modification costs but also extends the construction period. At the same time, the system lacks a unified monitoring and management platform, making it impossible to integrate and analyze the operating data of different subsystems and optimize configuration according to scenario characteristics, thus limiting its widespread application in diverse heating demand scenarios.

[0003] (5) Insufficient integration of waste heat recovery and energy storage technologies Although there are some waste heat recovery devices in the centralized heating network system, most of them use ordinary metal heat exchange structures and lack special designs to enhance heat exchange efficiency, resulting in limited waste heat recovery. Moreover, existing energy storage technologies are mostly independent of the heating system. For example, phase change energy storage devices are only used as auxiliary heat sources and are not organically linked with ground source heat pumps and centralized heating networks. They cannot store excess heat during low-load periods and release it during peak periods, so the system still needs to rely on the main heat source to operate at full load when the load peak-valley difference is large, making it difficult to improve energy utilization efficiency. Summary of the Invention

[0004] The purpose of this invention is to provide a ground source heat pump-central heating network coupling system based on multi-energy complementarity, so as to solve the problems mentioned in the background art, such as poor single-system coordination, low heating control accuracy and high energy consumption, weak system reliability and insufficient fault response capability, and poor scenario adaptability in existing heating technologies.

[0005] To achieve the above objectives, the present invention provides the following technical solution: A ground source heat pump-central heating network coupling system based on multi-energy complementarity includes a ground source heat pump subsystem, a central heating network subsystem, and an intelligent control center. The three are dynamically coupled through an energy exchange device. The ground source heat pump subsystem includes a buried pipe heat exchanger and a variable frequency heat pump unit, and the centralized heating network subsystem is equipped with a waste heat recovery device and a time-sharing valve. The intelligent control center has a built-in energy distribution model and an adaptive PID controller, and integrates a digital twin module and a fault diagnosis module. The energy exchange device includes a phase change energy storage unit and a plate heat exchanger, which are connected in series through a heat transfer oil circulation pipeline. The phase change temperature of the phase change material in the phase change energy storage unit is set to 25-35℃. The waste heat recovery device has built-in titanium-based baffles. The intelligent control center collects the operating parameters of the ground source heat pump subsystem, the centralized heating network subsystem and the energy exchange device, and uses the energy distribution model and adaptive PID controller to realize the energy scheduling and stable control of the entire coupled system.

[0006] Preferably, the energy allocation model takes minimizing the total energy consumption of the system and meeting the heating demand as its objective functions, and the expression of the objective function is: + + ; + ≥ ; in, The total energy consumption of the system. For the energy consumption of the ground source heat pump subsystem, For the energy consumption of the centralized heating network subsystem, Energy consumption of energy exchange devices; To supply heat to the ground source heat pump subsystem, To supply heat to the centralized heating network subsystem, To release heat for the energy exchange device, Total heat demand on the user side.

[0007] Preferably, the control parameters of the adaptive PID controller are adjusted using a fuzzy adaptive algorithm. The inputs to the fuzzy adaptive algorithm are the system supply and return water temperature difference deviation e and the deviation change rate ec, and the output is the proportional coefficient correction of the PID controller. Integral coefficient correction amount and differential coefficient correction amount The corrected PID control parameters are: = ; = ; = ; in, , , These are the initial proportional coefficient, initial integral coefficient, and initial derivative coefficient of the PID controller, respectively.

[0008] Preferably, the buried pipe heat exchanger adopts a U-shaped double-tube structure with an outer diameter of 32-40mm, a tube spacing of 1.5-2.5m, a buried depth of 80-120m, and the heat exchange medium of the buried pipe heat exchanger is an ethylene glycol aqueous solution with a mass concentration of 30%-40%.

[0009] Preferably, the compressor of the variable frequency heat pump unit is a variable frequency scroll compressor, whose cooling capacity adjustment range is 25%-100% of the rated cooling capacity, and the COP performance coefficient of the variable frequency heat pump unit is not less than 4.2 under rated operating conditions.

[0010] Preferably, the time-sharing scheduling valve is an electric regulating ball valve with a regulation accuracy of ±1% and a working pressure range of 0.6-2.5MPa. The opening and closing and regulation actions of the time-sharing scheduling valve are controlled by the intelligent control center according to the time-sharing heating demand command, which is generated based on the heat load change pattern of the user side at different times.

[0011] Preferably, the phase change material in the phase change energy storage unit is a composite salt phase change material, which is made by mixing 60%-70% sodium nitrate, 20%-30% potassium chloride and 5%-10% calcium chloride by mass, and the latent heat of the phase change material is not less than 200kJ / kg.

[0012] Preferably, the digital twin module constructs a three-dimensional digital model of the coupled system to map the operating status of the physical entity of the system in real time. The digital twin model is updated at a frequency of 1-5 seconds per update, and the digital twin module has the function of simulating the operating characteristics of the system under different outdoor temperatures and user heat loads.

[0013] Preferably, the fault diagnosis module adopts a fault diagnosis algorithm based on neural networks. The input layer of the neural network consists of key system operating parameters, including the outlet water temperature of the ground source heat pump, the supply pressure of the centralized heating network, and the temperature of the phase change energy storage unit. The output layer consists of fault types, including underground pipe blockage, time-sharing valve jamming, and phase change material failure. After detecting a fault, the fault diagnosis module can automatically generate a fault alarm signal and send it to the monitoring terminal.

[0014] Preferably, the titanium-based baffles are 1-2 mm thick and have textured surfaces with a depth of 0.2-0.5 mm. The titanium-based baffles are arranged in an alternating pattern within the waste heat recovery device, with a spacing of 5-8 mm between adjacent baffles, to enhance the turbulence of the fluid within the waste heat recovery device and improve heat exchange efficiency.

[0015] Compared with the prior art, the beneficial effects of the present invention are: I. High energy efficiency, achieving multi-energy synergistic energy conservation. This invention constructs a multi-energy complementary energy supply mode by dynamically coupling a ground-source heat pump subsystem and a centralized heating network subsystem, combined with a waste heat recovery device and a phase change energy storage unit. On the one hand, the buried pipe heat exchanger can stably extract shallow geothermal energy, and the variable frequency heat pump unit adapts to load changes through a cooling capacity adjustment range of 25%-100%, avoiding the energy waste of traditional heat pumps operating at full load. On the other hand, the titanium-based baffles of the centralized heating network can enhance the recovery efficiency of waste heat (such as waste heat from industrial equipment and air conditioning return air), and the phase change energy storage unit (phase change temperature 25-35℃) can store excess heat during low-load periods and release it during peak periods, reducing the system's dependence on a single energy source. In actual operation, the total energy consumption of the system is reduced by 25%-30% compared to traditional single heating systems, and the thermal utilization efficiency is increased to over 85%, significantly reducing energy consumption and carbon emissions. II. Precise operation and control, adaptable to complex thermal demand scenarios. The energy allocation model of the intelligent control center aims to minimize total energy consumption and meet heat demand. It achieves optimal energy scheduling by quantitatively calculating the energy supply ratios of ground source heat pumps, centralized heating networks, and phase change energy storage. An adaptive PID controller, combined with a fuzzy adaptive algorithm, can adjust the supply and return water temperature difference deviation and its rate of change in real time, controlling the temperature fluctuation within ±1℃ to meet the heat demands of various scenarios, including peak hours in residential areas, fluctuating temperatures in commercial complexes, and high-precision temperature control in industrial parks. Simultaneously, the digital twin module, through real-time mapping and simulation functions every 1-5 seconds, can predict load changes and optimize configurations in advance, avoiding energy waste or insufficient heating caused by supply-demand mismatch. III. The system has high reliability and timely fault response. The waste heat recovery device features built-in titanium-based baffles that combine corrosion resistance and thermal conductivity, adapting to complex operating conditions such as industrial waste heat and humid environments, thus extending the device's service life. The fault diagnosis module, based on a neural network algorithm, can monitor key parameters in real time, such as the outlet water temperature of the ground source heat pump, the pressure of the centralized heating network, and the temperature of the phase change energy storage unit. It quickly identifies faults such as underground pipe blockage, valve jamming, and phase change material failure, with a response time of ≤10 seconds and a false alarm rate of less than 1%. It can automatically generate alarm signals and push them to the monitoring terminal, reducing system downtime. Furthermore, the phase change energy storage unit can also act as an emergency heat source in extreme weather (such as prolonged low temperatures) or when a subsystem fails, ensuring continuous heating and enhancing the system's resilience. IV. It has a wide range of applications and combines economic efficiency with environmental friendliness. This invention, through modular design, allows for configuration adjustments based on the heat load scale and environmental conditions of different scenarios (residential communities, commercial complexes, and industrial parks in cold regions). For cold regions, the number of underground pipes and the capacity of heat pump units can be increased; for industrial scenarios, the adaptability of waste heat recovery devices and high-pressure valves can be enhanced, eliminating the need for overall system reconstruction and reducing scenario adaptation costs. From an economic perspective, the system reduces the operating time of heat pump units through waste heat recovery and phase change energy storage, lowering annual operating costs by 20%-25% compared to traditional centralized heating systems. Furthermore, core components such as phase change materials and titanium-based baffles have a service life of over 10 years, resulting in low long-term maintenance costs. From an environmental perspective, the efficient utilization of geothermal energy and waste heat reduces fossil fuel consumption, reducing carbon emissions by 300-500 tons per 10,000 square meters annually, aligning with the needs of low-carbon heating development. Attached Figure Description

[0016] The accompanying drawings are provided to further illustrate the invention and form part of the specification. They are explained in detail together with the embodiments of the invention, but do not constitute a limitation thereof.

[0017] Figure 1 This is a system block diagram of the present invention. Detailed Implementation

[0018] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0019] This invention proposes a multi-energy complementary ground source heat pump-central heating network coupling system, comprising a ground source heat pump subsystem 1, a central heating network subsystem 2, and an intelligent control center 3, which are dynamically coupled through an energy exchange device 4. The ground source heat pump subsystem 1 includes a buried pipe heat exchanger 11 and a variable frequency heat pump unit 12, while the central heating network subsystem 2 is equipped with a waste heat recovery device 21 and a time-sharing control valve 22. The intelligent control center 3 incorporates an energy distribution model 31 and an adaptive PID controller 32, and integrates a digital twin module 33 for fault diagnosis. Diagnostic module 34; Energy exchange device 4 includes phase change energy storage unit 41 and plate heat exchanger 42, which are connected in series through heat transfer oil circulation pipeline. The phase change temperature of the phase change material in phase change energy storage unit 41 is set to 25-35℃; Waste heat recovery device 21 has built-in titanium-based baffles 211. Intelligent control center 3 collects the operating parameters of ground source heat pump subsystem 1, centralized heating network subsystem 2 and energy exchange device 4, and uses energy distribution model 31 and adaptive PID controller 32 to realize energy scheduling and stable control of the entire coupled system.

[0020] Specifically, energy allocation model 31 takes minimizing total system energy consumption and meeting heat demand as its objective functions. The objective function expression is as follows: + + ; + ≥ ; in, The total energy consumption of the system. Energy consumption of ground source heat pump subsystem 1 Energy consumption of the centralized heating network subsystem 2 Energy consumption for energy exchange device 4; To supply heat to ground source heat pump subsystem 1, To supply heat to the centralized heating network subsystem 2, Heat is released for energy exchange device 4. Total heat demand on the user side.

[0021] It is worth noting that the control parameters of the adaptive PID controller 32 are adjusted using a fuzzy adaptive algorithm. The inputs to the fuzzy adaptive algorithm are the system supply and return water temperature difference deviation e and the deviation change rate ec, and the output is the proportional coefficient correction of the PID controller. Integral coefficient correction amount and differential coefficient correction amount The corrected PID control parameters are: = ; = ; = ; in, , , These are the initial proportional coefficient, initial integral coefficient, and initial derivative coefficient of the PID controller, respectively.

[0022] Furthermore, the buried pipe heat exchanger 11 adopts a U-shaped double-tube structure with an outer diameter of 32-40mm, a tube spacing of 1.5-2.5m, a buried pipe depth of 80-120m, and the heat exchange medium of the buried pipe heat exchanger 11 is an ethylene glycol aqueous solution with a mass concentration of 30%-40%.

[0023] Specifically, the compressor of the variable frequency heat pump unit 12 is a variable frequency scroll compressor, whose cooling capacity adjustment range is 25%-100% of the rated cooling capacity, and the COP performance coefficient of the variable frequency heat pump unit 12 is not less than 4.2 under rated operating conditions.

[0024] It is worth noting that the time-sharing scheduling valve 22 is an electric regulating ball valve with a regulation accuracy of ±1% and a working pressure range of 0.6-2.5MPa. The opening and closing and regulation actions of the time-sharing scheduling valve 22 are controlled by the intelligent control center 3 according to the time-sharing heating demand command. The time-sharing heating demand command is generated based on the heat load change pattern of the user side at different times.

[0025] It is worth noting that the phase change material in the phase change energy storage unit 41 is a composite salt phase change material, which is made by mixing 60%-70% sodium nitrate, 20%-30% potassium chloride and 5%-10% calcium chloride by mass. The latent heat of the phase change material is not less than 200kJ / kg.

[0026] Among them, the digital twin module 33 constructs a three-dimensional digital model of the coupled system to map the operating status of the physical entity of the system in real time. The update frequency of the digital twin model is 1-5 seconds / time, and the digital twin module 33 has the function of simulating the system operating characteristics under different outdoor temperatures and user heat loads. The fault diagnosis module 34 adopts a fault diagnosis algorithm based on neural networks. The input layer of the neural network is the key operating parameters of the system, including the outlet water temperature of the ground source heat pump, the supply pressure of the centralized heating network, and the temperature of the phase change energy storage unit. The output layer is the fault type, which includes underground pipe blockage, time-sharing valve jamming, and phase change material failure. After detecting a fault, the fault diagnosis module 34 can automatically generate a fault alarm signal and send it to the monitoring terminal.

[0027] In addition, the titanium-based baffle 211 has a thickness of 1-2 mm and a textured surface with a depth of 0.2-0.5 mm. The titanium-based baffle 211 is arranged in an alternating pattern in the waste heat recovery device 21, with a spacing of 5-8 mm between adjacent baffles, in order to enhance the turbulence of the fluid in the waste heat recovery device 21 and improve the heat exchange efficiency.

[0028] Example 1: Application in a residential community in a cold region (40°-45°N latitude, extreme winter temperature -25°C). This example focuses on 10 18-story residential buildings (total building area 80,000㎡, design heat load 60W / ㎡). The system configuration and operating parameters are as follows: This example focuses on cold regions between 40-45° north latitude (such as parts of Northeast China and Inner Mongolia). The extreme low temperature in this region during winter can reach -25°C. The heat demand of 10 18-story residential buildings (total building area of ​​80,000 square meters) is concentrated and stable, with prominent morning and evening peaks. The peak hours for residential heating are from 7-9 am and 5-9 pm, while the demand is relatively stable during other times. From a system configuration perspective, the ground source heat pump subsystem employs 300-hole U-shaped double-pipe buried pipes (outer diameter 38mm, spacing 2.0m, burial depth 100m), paired with two variable frequency units (COP=4.5) rated for 800kW of heating capacity. This ensures heating capacity in low-temperature environments while adapting to load fluctuations through variable frequency regulation. The titanium-based baffles (1.5mm thickness, 0.3mm texture depth) of the centralized heating network subsystem enhance waste heat recovery efficiency; the 300kW waste heat recovery capacity can supplement 1 / 4 of the peak heat demand, while the time-sharing valves precisely match the 20% increase in heating demand during morning and evening peak hours. The 50m³ phase change energy storage unit (composite salt ratio 65% sodium nitrate + 25% potassium chloride + 10% calcium chloride, latent heat 210kJ / kg) of the energy exchange device can store 10.5MWh of heat, storing heat during off-peak hours and releasing heat during peak hours to alleviate the pressure on the heat pump units. The intelligent control center uses an objective function: + + ; To achieve optimal energy consumption, a digital twin update frequency of 3 seconds and a fault response time of ≤10 seconds are used to ensure stable system operation. In terms of operational performance, the system's total heat supply meets 100% of the heat demand under winter design conditions, with a total energy consumption of only 480 kW / h. The energy consumption of the ground source heat pump subsystem is 267 kW / h, accounting for less than 60%. The synergistic effect of waste heat recovery and phase change energy storage significantly reduces the load on the heat pump unit, solving the problem of low-temperature heating in cold regions and achieving energy-saving operation.

[0029] Example 2: Application in a commercial complex (including shopping mall, office building, and hotel, with a total building area of ​​150,000 square meters and large fluctuations in heat load). This example is designed for a 50,000㎡ shopping mall (operating from 9:00 AM to 10:00 PM), an 80,000㎡ office building (operating from 8:00 AM to 6:00 PM), and a 20,000㎡ hotel (operating 24 hours a day). The system needs to adapt to heat load changes over multiple time periods. The configuration and operating data are as follows: This embodiment targets a commercial complex (total building area of ​​150,000 square meters) that includes a shopping mall, office building, and hotel. The core characteristics of this scenario are large fluctuations in heat load and significant differences in time periods. The shopping mall (9 am to 10 pm) and office building (8 am to 6 pm) have concentrated heat consumption during the day, while the hotel (24 hours) needs continuous and stable heating. The overlapping of the three heat consumption periods forms the peak load from 8 am to 10 am, while the demand at night is mainly from the hotel. The system configuration is designed to adapt to multi-period loads and maximize waste heat utilization: the ground source heat pump subsystem uses 450-hole large-diameter U-shaped pipes (outer diameter 40mm, spacing 2.5m, burial depth 120m), and three 1000kW inverter units (COP=4.3) can handle the demand changes of 2200kW during the morning peak and low load at night through a cooling capacity adjustment range of 25%-100%; the centralized heating network subsystem uses titanium-based baffles (thickness 2.0mm, texture depth 0.5mm) to enhance the recovery of waste heat from the return air of the shopping mall's air conditioning (500kW), and four time-sharing valves (pressure 1.8MPa) adapted to different areas can accurately reduce the pressure. During off-peak hours (0-6 AM), the office building supplies 30% of its heating capacity to avoid energy waste. The 80m³ phase change energy storage unit (70% sodium nitrate + 20% potassium chloride + 10% calcium chloride, latent heat 205kJ / kg) of the energy exchange device stores 8MWh of waste heat from the shopping mall / office building during the day and releases 6MWh of heat to the hotel at night, achieving peak-shifting energy supply. The adaptive PID controller in the intelligent control center controls the supply and return water temperature difference deviation e≤2℃ and the deviation change rate ec≤0.5℃ / min, keeping the supply and return water temperature difference fluctuation within ±1℃, meeting the hotel's high requirements for heating stability. A 0% false alarm rate ensures continuous operation of the commercial scenario. With this configuration, the system can not only cope with the complex load fluctuations of commercial complexes, but also control the heat pump energy consumption at the morning peak to 512kW / h through the synergy of waste heat recovery and phase change energy storage, which is more than 30% more energy-efficient than traditional single heating systems, while meeting the heating needs of different business formats.

[0030] Example 3: Industrial park application (including machining workshops and office buildings, total heat load 2000kW, requiring stable heating) This embodiment targets 5 machining workshops (requiring a constant temperature of 15℃ and a heat load of 1200kW) and 2 office buildings (heat load of 800kW). The system must withstand industrial waste heat fluctuations. The configuration and operating data are as follows: This embodiment is designed for an industrial park containing 5 machining workshops and 2 office buildings. The core requirements are stable heating and tolerance to waste heat fluctuations. The machining workshops need to maintain a constant temperature of 15℃ (accuracy ±0.5℃) to ensure the processing accuracy of the equipment. The total heat load is 2000kW, and the operation of the equipment in the workshops will generate unstable waste heat (fluctuation range ±20%). The office buildings need to be heated in the winter as usual. The system configuration prioritizes stability, resistance to fluctuations, and high adaptability: the ground source heat pump subsystem employs 500-hole high-density U-shaped pipes (outer diameter 32mm, spacing 1.5m, burial depth 80m), with four 600kW variable frequency units (COP=4.2) that can flexibly adjust heating capacity, providing 1400kW of conventional heating to cover basic needs, with surplus load supplemented by waste heat; the centralized heating network subsystem uses titanium-based baffles (1.0mm thickness, 0.2mm texture depth, 5mm spacing) adapted to the high flow velocity characteristics of industrial networks, supporting 800kW vehicle... The waste heat recovery capacity of the equipment can supplement 40% of the total heat demand. Three high-pressure time-sharing valves (pressure 2.5MPa) can withstand the high-pressure environment of the industrial pipeline network while controlling the network heat loss rate to ≤5%. The 100m³ large-capacity phase change energy storage unit (60% sodium nitrate + 30% potassium chloride + 10% calcium chloride, latent heat 200kJ / kg) of the energy exchange device can store 20MWh of heat, providing 300kW of supplementary heat during industrial waste heat fluctuations to prevent workshop temperature fluctuations. The intelligent control center uses an energy distribution model to constrain conditions. + ≥ , To ensure that the total heat supply meets the demand, the digital twin module can simulate the system operation under outdoor temperatures of -15℃ to 5℃, optimize the configuration in advance, and ensure the temperature accuracy of the workshop is ±0.5℃. Operational data shows that the total energy consumption of the system is 680 kW / h, of which the heat pump energy consumption is 333 kW / h. The efficient utilization of industrial waste heat significantly reduces operating costs. At the same time, the anti-fluctuation design ensures the constant temperature requirements of the machining workshop, solving the pain points of unstable waste heat and high heating accuracy requirements in industrial parks. Compared with traditional industrial heating systems, the energy consumption is reduced by 25%, and the heating reliability requirements for continuous production in the workshop are met.

[0031] The advantages of this invention based on a multi-energy complementary ground source heat pump-central heating network coupling system are: I. High energy efficiency, achieving multi-energy synergistic energy conservation. This invention constructs a multi-energy complementary energy supply mode by dynamically coupling a ground-source heat pump subsystem and a centralized heating network subsystem, combined with a waste heat recovery device and a phase change energy storage unit. On the one hand, the buried pipe heat exchanger can stably extract shallow geothermal energy, and the variable frequency heat pump unit adapts to load changes through a cooling capacity adjustment range of 25%-100%, avoiding the energy waste of traditional heat pumps operating at full load. On the other hand, the titanium-based baffles of the centralized heating network can enhance the recovery efficiency of waste heat (such as waste heat from industrial equipment and air conditioning return air), and the phase change energy storage unit (phase change temperature 25-35℃) can store excess heat during low-load periods and release it during peak periods, reducing the system's dependence on a single energy source. In actual operation, the total energy consumption of the system is reduced by 25%-30% compared to traditional single heating systems, and the thermal utilization efficiency is increased to over 85%, significantly reducing energy consumption and carbon emissions. II. Precise operation and control, adaptable to complex thermal demand scenarios. The energy allocation model of the intelligent control center aims to minimize total energy consumption and meet heat demand. It achieves optimal energy scheduling by quantitatively calculating the energy supply ratios of ground source heat pumps, centralized heating networks, and phase change energy storage. An adaptive PID controller, combined with a fuzzy adaptive algorithm, can adjust the supply and return water temperature difference deviation and its rate of change in real time, controlling the temperature fluctuation within ±1℃ to meet the heat demands of various scenarios, including peak hours in residential areas, fluctuating temperatures in commercial complexes, and high-precision temperature control in industrial parks. Simultaneously, the digital twin module, through real-time mapping and simulation functions every 1-5 seconds, can predict load changes and optimize configurations in advance, avoiding energy waste or insufficient heating caused by supply-demand mismatch. III. The system has high reliability and timely fault response. The waste heat recovery device features built-in titanium-based baffles that combine corrosion resistance and thermal conductivity, adapting to complex operating conditions such as industrial waste heat and humid environments, thus extending the device's service life. The fault diagnosis module, based on a neural network algorithm, can monitor key parameters in real time, such as the outlet water temperature of the ground source heat pump, the pressure of the centralized heating network, and the temperature of the phase change energy storage unit. It quickly identifies faults such as underground pipe blockage, valve jamming, and phase change material failure, with a response time of ≤10 seconds and a false alarm rate of less than 1%. It can automatically generate alarm signals and push them to the monitoring terminal, reducing system downtime. Furthermore, the phase change energy storage unit can also act as an emergency heat source in extreme weather (such as prolonged low temperatures) or when a subsystem fails, ensuring continuous heating and enhancing the system's resilience. IV. It has a wide range of applications and combines economic efficiency with environmental friendliness. This invention, through modular design, allows for configuration adjustments based on the heat load scale and environmental conditions of different scenarios (residential communities, commercial complexes, and industrial parks in cold regions). For cold regions, the number of underground pipes and the capacity of heat pump units can be increased; for industrial scenarios, the adaptability of waste heat recovery devices and high-pressure valves can be enhanced, eliminating the need for overall system reconstruction and reducing scenario adaptation costs. From an economic perspective, the system reduces the operating time of heat pump units through waste heat recovery and phase change energy storage, lowering annual operating costs by 20%-25% compared to traditional centralized heating systems. Furthermore, core components such as phase change materials and titanium-based baffles have a service life of over 10 years, resulting in low long-term maintenance costs. From an environmental perspective, the efficient utilization of geothermal energy and waste heat reduces fossil fuel consumption, reducing carbon emissions by 300-500 tons per 10,000 square meters annually, aligning with the needs of low-carbon heating development.

[0032] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely preferred examples and are not intended to limit the invention. Various changes and modifications can be made to the invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the present invention as claimed. The scope of protection of the present invention is defined by the appended claims and their equivalents.

Claims

1. A ground-source heat pump-central heating network coupling system based on multi-energy complementarity, characterized in that, It includes a ground source heat pump subsystem (1), a centralized heating network subsystem (2), and an intelligent control center (3), which are dynamically coupled through an energy exchange device (4); The ground source heat pump subsystem (1) includes a buried pipe heat exchanger (11) and a variable frequency heat pump unit (12), and the centralized heating network subsystem (2) is equipped with a waste heat recovery device (21) and a time-sharing scheduling valve (22). The intelligent control center (3) has a built-in energy distribution model (31) and an adaptive PID controller (32), and integrates a digital twin module (33) and a fault diagnosis module (34). The energy exchange device (4) includes a phase change energy storage unit (41) and a plate heat exchanger (42), which are connected in series through a heat transfer oil circulation pipeline. The phase change temperature of the phase change material in the phase change energy storage unit (41) is set to 25-35℃. The waste heat recovery device (21) has a built-in titanium-based baffle plate (211). The intelligent control center (3) collects the operating parameters of the ground source heat pump subsystem (1), the centralized heating network subsystem (2) and the energy exchange device (4), and uses the energy distribution model (31) and the adaptive PID controller (32) to realize the energy scheduling and stable control of the entire coupled system.

2. The ground source heat pump-central heating network coupling system based on multi-energy complementarity according to claim 1, characterized in that: The energy allocation model (31) takes the minimum total energy consumption of the system and the heat supply meeting the demand as the objective function, and the expression of the objective function is: + + ； + ≥ ； in, This represents the total energy consumption of the system. Energy consumption of the ground source heat pump subsystem (1), Energy consumption of the centralized heating network subsystem (2), Energy consumption of energy exchange devices (4); To supply heat to the ground source heat pump subsystem (1), To supply heat to the centralized heating network subsystem (2), For the energy exchange device (4) to release heat, Total heat demand on the user side.

3. The ground source heat pump-central heating network coupling system based on multi-energy complementarity according to claim 1, characterized in that: The control parameters of the adaptive PID controller (32) are adjusted using a fuzzy adaptive algorithm. The inputs of the fuzzy adaptive algorithm are the system supply and return water temperature difference deviation e and the deviation change rate ec, and the output is the proportional coefficient correction of the PID controller. Integral coefficient correction amount and differential coefficient correction amount The corrected PID control parameters are as follows: = ； = ； = ； in, , , These are the initial proportional coefficient, initial integral coefficient, and initial derivative coefficient of the PID controller, respectively.

4. The ground source heat pump-central heating network coupling system based on multi-energy complementarity according to claim 1, characterized in that: The buried pipe heat exchanger (11) adopts a U-shaped double pipe structure with an outer diameter of 32-40mm, a pipe spacing of 1.5-2.5m, a buried pipe depth of 80-120m, and the heat exchange medium of the buried pipe heat exchanger (11) is an ethylene glycol aqueous solution with a mass concentration of 30%-40%.

5. The ground source heat pump-central heating network coupling system based on multi-energy complementarity according to claim 1, characterized in that: The compressor of the variable frequency heat pump unit (12) is a variable frequency scroll compressor, whose cooling capacity adjustment range is 25%-100% of the rated cooling capacity, and the COP performance coefficient of the variable frequency heat pump unit (12) is not less than 4.2 under rated operating conditions.

6. The ground source heat pump-central heating network coupling system based on multi-energy complementarity according to claim 1, characterized in that: The time-sharing scheduling valve (22) is an electric regulating ball valve with a regulation accuracy of ±1% and a working pressure range of 0.6-2.5MPa. The opening and closing and regulation actions of the time-sharing scheduling valve (22) are controlled by the intelligent control center (3) according to the time-sharing heating demand command. The time-sharing heating demand command is generated according to the heat load change pattern of different time periods on the user side.

7. The ground source heat pump-central heating network coupling system based on multi-energy complementarity according to claim 1, characterized in that: The phase change material in the phase change energy storage unit (41) is a composite salt phase change material, which is made by mixing sodium nitrate (60%-70% by mass), potassium chloride (20%-30% by mass), and calcium chloride (5%-10% by mass). The latent heat of the phase change material is not less than 200 kJ / kg.

8. The ground source heat pump-central heating network coupling system based on multi-energy complementarity according to claim 1, characterized in that: The digital twin module (33) constructs a three-dimensional digital model of the coupled system to map the operating status of the physical entity of the system in real time. The update frequency of the digital twin model is 1-5 seconds / time, and the digital twin module (33) has the function of simulating the operating characteristics of the system under different outdoor temperatures and user heat loads.

9. The ground source heat pump-central heating network coupling system based on multi-energy complementarity according to claim 1, characterized in that: The fault diagnosis module (34) adopts a fault diagnosis algorithm based on neural networks. The input layer of the neural network consists of key operating parameters of the system, including the outlet water temperature of the ground source heat pump, the pressure of the centralized heating network, and the temperature of the phase change energy storage unit. The output layer consists of fault types, including underground pipe blockage, time-sharing valve jamming, and phase change material failure. After detecting a fault, the fault diagnosis module (34) can automatically generate a fault alarm signal and send it to the monitoring terminal.

10. The ground source heat pump-central heating network coupling system based on multi-energy complementarity according to claim 1, characterized in that: The titanium-based baffle (211) has a thickness of 1-2 mm and a textured surface with a depth of 0.2-0.5 mm. The titanium-based baffle (211) is arranged in an alternating pattern in the waste heat recovery device (21), with a spacing of 5-8 mm between adjacent baffles, in order to enhance the turbulence of the fluid in the waste heat recovery device (21) and improve the heat exchange efficiency.

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