Method and system for transforming mining area wasteland hot well

Abstract

The invention discloses a transformation method and system for a mining area wasteland hot well, and relates to the technical field of development and utilization of geothermal resources, and the transformation method comprises the following steps: carrying out sealing treatment on cracks and damaged parts of a well mouth and a well wall of the mining area wasteland hot well; a thermal insulation material is installed on the well wall of the wasteland hot well subjected to sealing treatment; selecting a corresponding heat storage material according to the ground temperature gradient of the wasteland hot well and the corresponding well depth, and obtaining the laying amount of the heat storage material based on the volume of the wasteland hot well; the heat storage material is arranged in the waste land hot well provided with the heat preservation material according to the laying amount, and a buried pipe heat exchanger is arranged on the inner wall of the heat storage material and connected with a ground system. The system is not limited to single winter heating or hot water supply, the energy utilization efficiency of the geothermal well can be improved, organic combination of geothermal resources and renewable energy sources is achieved, and the diversified requirements of different fields are met.

Description

Technical Field

[0001] The present invention relates to the technical field of development and utilization of geothermal resources, and particularly to a method and system for reforming abandoned geothermal wells in mining areas. Background Art

[0002] With the continuous development and exploitation of resources in mining areas, many mining areas have left a large number of abandoned geothermal wells due to resource exhaustion or the update of mining technologies. The initial function of these geothermal wells is usually to provide heat energy for mining areas or to be used in other resource extraction processes. However, due to reasons such as the closure of mining areas, equipment aging, outdated technologies, or declining economic benefits, their original uses gradually lose meaning and are thus abandoned. However, these geothermal wells do not mean that they have completely lost their value. In fact, abandoned geothermal wells usually still have a certain potential for geothermal resource reserves, which can provide an important development platform for energy reuse and new energy technologies. However, the current level of development and utilization of abandoned geothermal wells is relatively low, and there is a phenomenon of resource waste.

[0003] The application mode of traditional geothermal wells is relatively single, mostly limited to direct heating or providing hot water for daily life. This utilization method has obvious limitations. Especially in seasons or periods when heat supply is not required, due to the lack of efficient heat storage technologies, geothermal resources often remain idle and cannot be effectively stored for future use, resulting in energy waste.

[0004] The current methods for reforming abandoned geothermal wells mainly seal the wellhead and cracks in the well wall and introduce heat storage materials to restore the basic functions of the geothermal wells and extend their service life. However, even in some reforming schemes where heat storage materials are introduced, the selection is often limited to traditional sensible heat storage materials (such as water or rocks). These materials have a low heat storage density, resulting in low heat transfer efficiency and significant energy losses during the heat storage and heat release processes. At the same time, these reforming methods usually only focus on a single use, such as winter heating or hot water supply, without considering how to store heat during non-heating seasons or cope with variable heat energy demands. Summary of the Invention

[0005] Based on the defects existing in the above-mentioned prior art, the present invention provides a method and system for reforming abandoned geothermal wells in mining areas, which solves the existing problems.

[0006] The present invention adopts the following technical solutions:

[0007] In a first aspect, the present invention provides a method for reforming an abandoned geothermal well in a mining area, comprising the following steps:

[0008] Seal the wellhead, cracks and damaged parts of the well wall of the abandoned geothermal well in the mining area;

[0009] Install thermal insulation materials on the well wall of the abandoned geothermal well after the sealing treatment;

[0010] Select the corresponding heat storage material according to the geothermal gradient and the corresponding well depth of the abandoned geothermal well, and obtain the laying amount of the heat storage material based on the volume of the abandoned geothermal well;

[0011] Arrange the heat storage material in the abandoned geothermal well after installing the thermal insulation material according to the laying amount, set up a buried pipe heat exchanger on the inner wall of the heat storage material, and connect the buried pipe heat exchanger to the ground system; the ground system includes a temperature control system and a domestic water system, and the temperature control system is used to obtain the stored heat of the heat storage material, and convert the external electric energy into heat energy and store it in the heat storage material during the non-heating period or when the stored heat is less than the preset value; during the heating period, transfer the stored heat to the domestic water system through the buried pipe heat exchanger.

[0012] Preferably, the selection of the corresponding heat storage material according to the geothermal gradient and well depth includes:

[0013] Obtain the geothermal gradient of the abandoned geothermal well through the following formula:

[0014]

[0015] In the formula, G is the geothermal gradient, ΔZ is the depth, and ΔT1 is the temperature difference between the rock and soil at the corresponding depth;

[0016] When the geothermal gradient of the abandoned geothermal well is 10 - 25 °C and its depth is 0 m - 400 m, use an organic material with a melting point lower than 60 °C as the heat storage material;

[0017] When the geothermal gradient of the abandoned geothermal well is 20 - 35 °C and its depth is 400 m - 1500 m, use a composite phase change material with a melting point between 60 - 150 °C as the heat storage material;

[0018] When the geothermal gradient of the abandoned geothermal well is above 35 °C and its depth is above 1500 m, use a high-temperature molten salt material with a melting point between 150 - 500 °C as the heat storage material.

[0019] Preferably, the laying amount of the heat storage material is obtained based on the volume of the abandoned geothermal well, and the laying amount is specifically as follows:

[0020] V = π * r 2 * H;

[0021] M = ρ * V;

[0022] In the formula, V is the well volume, r is the wellhead radius, H is the well depth, M is the mass of the laid heat storage material, and ρ is the density of the heat storage material.

[0023] Preferably, the temperature control system is used to obtain the stored heat of the heat storage material, and specifically includes the following steps:

[0024] Obtaining the heat loss of the heat storage material:

[0025] Q loss = k * A * ΔT3 * t / d;

[0026] In the formula, Q loss is the heat loss, K is the thermal conductivity of the heat insulation material, A is the wellbore area, ΔT3 is the temperature difference between the heat storage material and the wellbore, t is the time, and d is the thickness of the heat insulation material;

[0027] Obtaining the heat of the heat storage material:

[0028] E = Q s -Q d ;

[0029] In the formula, E is the heat in the current heat storage device, Q s is the input heat, and Q d is the output heat;

[0030] Obtaining the heat storage efficiency from the heat and heat loss of the heat storage material:

[0031]

[0032] In the formula, η is the heat storage efficiency.

[0033] Preferably, the preset value is 5% - 10%.

[0034] Preferably, there is a backfill material between the heat storage material and the buried pipe heat exchanger.

[0035] Preferably, the circulating working fluid of the buried pipe heat exchanger is water, and the domestic water system includes:

[0036] A purification and filtration device, whose input end is connected to an output end of the buried pipe heat exchanger through a control valve, and is used to filter the hot water output by the buried pipe heat exchanger;

[0037] A supplementary water tank, whose input end is connected to the output end of the purification and filtration device, and is used to store the filtered hot water;

[0038] A heat pump, whose input end is connected to the other output end of the buried pipe heat exchanger through a control valve, and is used to heat the hot water output by the buried pipe heat exchanger;

[0039] The output ends of the supplementary water tank and the heat pump are connected to the input end of the user side, and the output end of the user side is connected to the input end of the buried pipe heat exchanger.

[0040] In a second aspect, the present invention provides a transformation system for abandoned geothermal wells in mining areas, including:

[0041] A sealing module for sealing the wellhead, cracks and damaged parts of the well wall of abandoned geothermal wells in mining areas;

[0042] An installation module for installing thermal insulation materials on the well wall of the sealed abandoned geothermal well;

[0043] A selection module for selecting corresponding heat storage materials according to the geothermal gradient and corresponding well depth of the abandoned geothermal well, and obtaining the laying amount of heat storage materials based on the volume of the abandoned geothermal well;

[0044] A connection module for arranging heat storage materials in the abandoned geothermal well after installing thermal insulation materials according to the laying amount, setting a buried pipe heat exchanger on the inner wall of the heat storage materials, and connecting the buried pipe heat exchanger with the ground system; the ground system includes a temperature control system and a domestic water system, the temperature control system is used to obtain the stored heat of the heat storage materials, and convert the external electric energy into heat energy and store it in the heat storage materials during non-heating periods or when the stored heat is less than a preset value; during the heating period, transfer the stored heat to the domestic water system through the buried pipe heat exchanger.

[0045] Compared with the prior art, the above at least one technical solution adopted by the present invention can achieve the following beneficial effects:

[0046] The present invention first seals the wellhead, cracks and damaged parts of the well wall of the abandoned geothermal well in the mining area and installs thermal insulation materials; selects corresponding heat storage materials according to the geothermal gradient and corresponding well depth of the abandoned geothermal well, and obtains the laying amount of heat storage materials based on the volume of the abandoned geothermal well. By reasonably selecting heat storage materials, the heat storage efficiency and applicability of different types of geothermal wells can be effectively improved. At the same time, a buried pipe heat exchanger is set on the inner wall of the heat storage materials and connected with the ground system. The ground system converts the external electric energy into heat energy and stores it in the heat storage materials during non-heating periods or when the stored heat is less than a preset value; during the heating period, transfers the stored heat to the domestic water system through the buried pipe heat exchanger, so as to realize the long-term and stable storage and use of energy. The present invention is not limited to single winter heating or hot water supply, can improve the energy utilization efficiency of geothermal wells, and realize the organic combination of geothermal resources and renewable energy to meet the diverse needs of different fields. Description of the Drawings

[0047] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0048] Figure 1Flow chart of a method for transforming abandoned geothermal wells in a mining area according to the present invention;

[0049] Figure 2 Circulation structure diagram of the present invention;

[0050] Figure 3 Operation flow chart of the present invention.

[0051] In the figure: 1 - buried pipe heat exchanger, 2 - backfill material, 3 - heat storage material, 4 - rock and soil mass, 5 - control valve, 6 - purification and filtration device, 7 - make-up water tank, 8 - heat pump, 9 - monitoring system, 10 - user side. Detailed implementation manners

[0052] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0053] How to scientifically and reasonably develop the potential value of abandoned geothermal wells has become an urgent technical problem in the current field of geothermal energy utilization. The present invention aims to solve the existing problems and proposes a new way of using abandoned geothermal wells, storing thermal energy when domestic hot water or heating is not needed, and providing stable heating or domestic hot water when needed.

[0054] The purpose of the present invention is to provide a method for transforming abandoned geothermal wells in a mining area, which can store thermal energy when not heating, and realize the supply of heating or domestic hot water when needed, improving the utilization efficiency of geothermal resources. Refer to Figure 1 , including the following steps:

[0055] S1: Seal the wellhead, cracks and damaged parts of the well wall of the abandoned geothermal well in the mining area.

[0056] The transformation of abandoned geothermal wells is a key step in the redevelopment and utilization of geothermal resources. First, it is necessary to comprehensively clean the well, remove the accumulated impurities and sediments, ensure the smoothness of the pipelines in the well, and restore its basic transportation and storage functions. In this process, methods such as high-pressure flushing and mechanical cleaning can be used, and at the same time, the well structure is detected to exclude possible heat leakage points and cracks.

[0057] By detecting the integrity of the well structure, seal the cracks and damaged parts of the wellhead and well wall, and use high-temperature resistant and corrosion-resistant sealing materials to fill the cracks and install sealing valves to prevent heat leakage.

[0058] S2: Install thermal insulation materials on the wellbore of the abandoned geothermal well after sealing treatment.

[0059] After cleaning, install high-efficiency thermal insulation materials inside the wellbore. These materials need to have excellent high-temperature resistance and corrosion resistance, such as aerogel, fiberglass, or ceramic fiber. The purpose of installing thermal insulation materials is to reduce the loss of heat conduction from the well to the outside, so as to reduce the loss of heat during storage, extend the thermal energy storage time, and thus improve the storage efficiency of geothermal resources, laying a solid foundation for the operation of subsequent heat storage devices. During construction, it is necessary to ensure that the thermal insulation materials are closely attached to the wellbore, and at the same time, add a protective layer to improve durability. This transformation can not only improve the utilization efficiency of geothermal resources but also extend the service life of geothermal wells, providing important support for the sustainable development of energy.

[0060] S3: Obtain the geothermal temperature of the area where the abandoned geothermal well is located, and select the corresponding heat storage material according to the geothermal temperature and well depth.

[0061] The design of the heat storage device includes the selection of heat storage materials and the calculation of the corresponding heat storage capacity.

[0062] For the selection of heat storage materials, first, the local geothermal gradient can be obtained by referring to the relevant local geothermal geological parameters or calculated according to formula (1):

[0063]

[0064] In the formula, G is the geothermal gradient, ΔZ is the depth, and ΔT1 is the temperature difference between rock and soil at the corresponding depth.

[0065] According to the temperature range and application requirements of the geothermal well, the system can select different types of heat storage materials according to the geothermal gradient and the corresponding well depth to achieve efficient heat storage and thermal energy utilization. The depth of shallow geothermal wells is generally between 0 and 400 meters, the depth of medium geothermal wells is between 400 and 1500 meters, and geothermal wells with a depth of more than 1500 meters are deep geothermal wells.

[0066] When the geothermal temperature of a shallow geothermal well is 10 - 25°C, organic materials with a melting point below 60°C (such as ethylene glycol or paraffin) are usually used as the heat storage medium. For medium-temperature geothermal wells with a geothermal temperature of 20 - 35°C, composite phase change materials (such as a mixture of paraffin and inorganic salts) can be selected, with a melting point between 60 - 150°C and the characteristic of high heat capacity. For high-temperature geothermal wells with a geothermal temperature above 35°C, high-temperature molten salts need to be used as heat storage materials. These materials have a melting point between 150 - 500°C and have high heat storage density and good thermal stability. By reasonably selecting heat storage materials, the heat storage efficiency and applicability of different types of geothermal wells can be effectively improved.

[0067] S4: Obtain the laying quantity of the heat storage material based on the volume of the abandoned geothermal well.

[0068] Calculation of heat storage capacity: According to formulas (2)-(4), the laying amount of the heat storage material and the corresponding heat storage amount can be quantitatively obtained, so as to calculate the relevant content of the heat storage material according to the actual heat storage demand.

[0069] Calculation formula for the volume of the well body:

[0070] V = π * r 2 * H (2);

[0071] In the formula, V is the volume of the well body, r is the radius of the wellhead, and H is the well depth.

[0072] Calculation formula for the mass of the heat storage material:

[0073] M = ρ * V (3);

[0074] In the formula, M is the mass of the laid heat storage material, and ρ is the density of the heat storage material.

[0075] Calculation formula for heat:

[0076] Q = CMΔT2 (4);

[0077] In the formula, Q is the heat storage amount, C is the specific heat of the heat storage material, and ΔT2 is the heat storage temperature difference.

[0078] By arranging the heat storage material, the heat energy generated in the geothermal well can be effectively stored for heating or providing domestic hot water when needed. These heat storage materials are coupled with the natural hot water system in the geothermal well (some geothermal water originally existing in the geothermal well, which is heated by the underground heat source and can be used as the source of heat storage), and the natural heat energy of the underground geothermal resources is used to heat the heat storage materials to achieve efficient heat storage and stable output of heat. In this way, not only the problem of heat waste in the traditional geothermal utilization process is avoided, but also the flexible application ability of geothermal resources is improved, providing technical support for the comprehensive reuse of geothermal wells.

[0079] S5: Install a buried pipe heat exchanger on the inner wall of the heat storage material and connect the buried pipe heat exchanger to the ground system.

[0080] Install a temperature control system on the surface of the geothermal well, which can realize the real-time monitoring of the temperature in the well, and calculate and feedback the real-time heat storage efficiency according to formulas (5) and (6) by controlling the working state of the heat storage device. According to formula (7), the system will dynamically adjust according to the real-time monitored heat demand to achieve dynamic management of heat.

[0081] Calculation of heat loss:

[0082] Q loss = k * A * ΔT3 * t / d (5);

[0083] K is the thermal conductivity of the thermal insulation material (unit: W / m·K), A is the area of the wellbore (unit: m 2 ), ΔT3 is the temperature difference between the heat storage material and the wellbore (unit: K), t is the time (unit: s), and d is the thickness of the thermal insulation material (unit: m).

[0084] Calculation of heat storage efficiency:

[0085]

[0086] Dynamic heat storage control formula:

[0087] E = Q s -Q d (7);

[0088] E is the heat in the current heat storage material, Q s is the input heat, that is, the energy in the rock and soil, Q d is the output heat, that is, the energy consumed for heating or domestic hot water.

[0089] The system has a two-way heat exchange function: during the non-heating period or when the heat storage efficiency is low (i.e., the heat storage efficiency is less than 5%-10%), the excess electric energy generated by external renewable energy is used to convert it into heat energy and store it in the well; during the heating period, through a high-efficiency heat exchanger, the stored heat is efficiently released for heating or providing domestic hot water, so as to realize the long-term and stable storage and use of energy. This intelligent management method can improve the energy utilization efficiency of the geothermal well and realize the organic combination of geothermal resources and renewable energy.

[0090] The excess electric energy generated by external renewable energy (such as solar energy and wind energy) can be converted into heat energy through an electric heating device (such as an electric heating tube or an electric heating element). This heat energy is then transferred to the heat storage material through a heating device (an electric heating rod or an electromagnetic induction heater). These heat storage materials can store heat at high temperatures and efficiently release it through the heat exchange system when heating is required.

[0091] During the non-heating period, the geothermal well can store the heat converted from external electric energy and stably release it when needed, realizing the dynamic management of energy and improving the utilization efficiency of geothermal resources.

[0092] Refer to Figure 2 and Figure 3, the buried pipe heat exchanger 1 is used to efficiently extract geothermal energy from abandoned wells. Its circulating working fluid is water, and the arrows indicate the flow direction of the working fluid. The sustainable recycling of thermal energy is achieved through a closed-loop design. The backfill material 2 is filled between the buried pipes and the heat storage material to eliminate possible voids during heat transfer, ensuring close contact between the two, thereby significantly improving the heat transfer efficiency and heat storage performance. The heat storage material 3 is used to store the heat in the geothermal well when direct extraction of geothermal energy is not required, for subsequent heating or domestic hot water needs. It is selected based on real-time monitoring data of the geothermal gradient and well depth, and materials with high heat capacity and efficient heat storage performance are often chosen. The rock and soil mass 4 is the rock and soil structure around the geothermal well, providing stable support for the buried pipes and heat storage system, and at the same time playing a role in slow heat transfer, helping to maintain the temperature stability of the heat storage material. The control valve 5 is installed at the outlet of the buried pipe to regulate the flow direction of the high-temperature hot water. During heating, the upper branch control valve is opened; when providing domestic hot water, the lower branch control valve is opened to achieve flexible heat energy distribution. The purification and filtration device 6 conducts preliminary water quality treatment on the extracted high-temperature hot water to remove impurities, particulate matter, and sediment, ensuring water quality safety to meet subsequent usage requirements. The makeup water tank 7 is used to store the preliminarily purified high-temperature hot water and conduct secondary treatment to ensure that the water quality of domestic water meets the standards and the temperature is appropriate, providing stable water supply guarantee for users. The heat pump 8 upgrades the quality of the hot water temperature to provide efficient energy support for the heating or hot water demand on the user side, and at the same time optimizes the overall operating efficiency of the system. The monitoring system 9 arranges temperature sensors at the wellhead inlet, outlet, and the position of the heat storage material to monitor the operating temperature of the geothermal well in real time, ensure the safe operation of the system, and provide accurate operating data for optimized management. The user side 10 is for the user end to extract heat energy from the system for heating or providing domestic hot water according to actual needs. The system can intelligently adjust the heating intensity to ensure efficient utilization of heat energy and a comfortable user experience.

[0093] An intelligent control system is configured at the geothermal wellhead, capable of realizing the automated management of the entire heat storage and heat supply process. A control cabinet is installed at the wellhead, which integrates a temperature control module, a heat sensor, and a data transmission module inside, and can collect and monitor the temperature changes in the well, the status of the heat storage device, and the heat transfer efficiency in real time. The control system is connected to the energy management platform of the mining area through the network, supporting remote data transmission and adjustment functions. Users can remotely view the operating conditions of the geothermal well through the platform and adjust the working status of the system according to their needs. In addition, the system has an early warning management function. When temperature anomalies, heat leakage, or equipment failures occur, it can alarm in time and send maintenance prompts, thus ensuring the safety and reliability of the entire geothermal well operating system.

[0094] According to the actual needs on the user side, a flexible heating and domestic water system can be designed to make full use of geothermal well resources. Under heating demand, the hot water at the outlet of the geothermal well is combined with the heat pump system. After the temperature grade of the hot water is raised by the heat pump, it is transported to the user side to meet the indoor heating demand and achieve efficient and stable heat energy supply. Under the demand for domestic hot water, the hot water at the outlet of the geothermal well can be led to another pipeline, equipped with efficient impurity removal, filtration and sterilization treatment devices. After ensuring that the water quality meets the safety standards of domestic water, it is then transported to the user side for use. Through this demand-oriented design, not only can the efficient utilization of geothermal resources be realized, but also the heat demand in different application scenarios can be flexibly responded to, the reliability of the system and the user experience can be improved, while reducing energy waste and operating costs.

[0095] Online monitoring equipment is configured to monitor the water quality, water volume and waste heat utilization in real time, and through remote data transmission technology, unattended fully automatic operation and early warning management are realized. This system can collect and analyze key operation data in a timely manner to ensure the efficient and stable operation of the equipment. At the same time, it can quickly issue an early warning when an abnormal situation occurs, facilitating remote intervention and maintenance, and greatly improving the operation efficiency and safety of the system.

[0096] To meet the actual needs of users, the operation design of the geothermal well heating and hot water system fully considers efficiency and stability. Users extract hot water from the geothermal well through pipelines, and the configuration of circulation pumps ensures the stability and continuity of the hot water flow, providing continuous heat source support for the user side. During the use of heating or domestic hot water, the efficient heat exchanger installed in the pipeline system can quickly transfer the heat of the hot water in the geothermal well to the user side, while avoiding the pollution problem caused by direct use of hot water. This heat exchange method can flexibly adjust the heat supply intensity according to user needs to meet the heat demand in different scenarios, so as to maximize resource utilization and minimize operating costs, ensuring that the user side always obtains stable and efficient heat energy support.

[0097] Based on the same concept, the present invention also provides a transformation system for abandoned geothermal wells in mining areas, including a sealing module, an installation module, a selection module and a connection module.

[0098] The sealing module is used to seal the wellhead, cracks and damaged parts of the well wall of the abandoned geothermal well in the mining area.

[0099] The installation module is used to install thermal insulation materials on the well wall of the abandoned geothermal well after sealing treatment.

[0100] The selection module is used to select corresponding heat storage materials according to the geothermal gradient and the corresponding well depth of the abandoned geothermal well, and obtain the laying amount of the heat storage materials based on the volume of the abandoned geothermal well.

[0101] The connection module is used to arrange the heat storage material in the abandoned geothermal well after installing the thermal insulation material according to the laying amount, and a buried tube heat exchanger is arranged on the inner wall of the heat storage material to connect the buried tube heat exchanger with the ground system; the ground system includes a temperature control system and a domestic water system. The temperature control system is used to obtain the stored heat of the heat storage material and convert the external electric energy into heat energy during the non-heating period or when the stored heat is less than the preset value and store it in the heat storage material; during the heating period, the stored heat is transferred to the domestic water system through the buried tube heat exchanger.

[0102] The present invention is not limited to single waste heat recovery, but expands the energy utilization scenarios through innovative design, achieving comprehensive coverage from soil remediation to residential heating and domestic hot water supply. Especially in the energy utilization of abandoned geothermal wells, it breaks through the limitations of traditional single functions and builds it into an integrated energy service platform, significantly improving energy utilization efficiency and social benefits, and providing a new solution for the modern urban energy system. This expansion of uses and innovation of scenarios make the present invention more valuable in application and market potential, and can meet the diverse needs of different fields.

[0103] For deep geothermal wells, the present invention uses high-performance heat storage materials, such as high-temperature heat storage media like molten salt, breaking through the limitations of the existing method using phase change materials and greatly improving the energy storage density and stability of heat energy storage. Thanks to this efficient heat storage technology, the present invention can not only quickly store waste heat in a short time, but also achieve long-term stable output of heat, meeting the heating and hot water needs of users all day long and throughout the seasons. Especially in scenarios where large-scale energy storage is required, this technical advantage is particularly prominent, providing a reliable guarantee for energy management and heat supply, and enhancing the sustainable operation ability of the system.

[0104] The present invention comprehensively realizes the intelligence and high efficiency of heat utilization by introducing a smart heat management system. This system combines real-time temperature monitoring, two-way heat flow control and dynamic heat exchange functions, and can automatically adjust heat storage and output according to the actual needs of users. This intelligent dynamic management method not only adapts to the changing heat demand, but also significantly improves the flexibility and stability of the system operation.

[0105] The present invention fundamentally improves the user experience by adopting the design of combining advanced heat pump technology and efficient heat exchangers. This system can flexibly provide heat at different temperatures according to the actual needs of users, which can be used for winter heating and meet the supply demand of domestic hot water. In addition, the optimized design greatly reduces the operation cost, while improving the operation reliability and service life of the system, providing a more efficient and economical heat solution for users.

[0106] The present invention proposes an intelligent selection method for heat storage materials that combines the characteristics of geothermal gradient, well depth, and geothermal well temperature. By introducing the geothermal gradient formula (1) and the heat storage capacity calculation formulas (2)-(4), the system can dynamically determine the types of heat storage materials required for different geothermal wells and their arrangement quantities. For shallow, medium, and high-temperature geothermal wells, organic materials, composite phase change materials, and high-temperature molten salts are respectively selected as heat storage media, and through layered arrangement and optimization calculation, an efficient adaptation of the heat storage system is achieved.

[0107] The present invention innovatively integrates a smart heat management system that dynamically adjusts the heat storage and heat release processes by real-time monitoring of the well temperature and heat storage status. The system uses the heat loss formula (5), the heat extraction efficiency formula (6), and the dynamic heat storage control formula (7), combines the excess electric energy of renewable energy sources (such as photovoltaic and wind power), and converts external energy into heat to be stored in the geothermal well. At the same time, during the peak period of heating or domestic hot water demand, the heat is released to the user side through an efficient heat exchanger to achieve the dynamic and efficient utilization of heat.

[0108] The present invention innovatively integrates heat pump technology with an efficient heat exchanger to design an intelligent system that can dynamically regulate the heat output according to the user-side demand. By real-time monitoring of the heating or hot water demand at the user side, the system can flexibly adjust the working state of the heat pump and the heat output efficiency of the heat exchanger to accurately provide heat energy at different temperatures. This design is particularly suitable for seasonal and diverse heat demand, and can not only provide efficient heating in winter but also stably supply domestic hot water throughout the year.

[0109] Although the preferred embodiments of the present invention have been described, those skilled in the art can make additional changes and modifications once they learn the basic creative concept. Therefore, the appended claims are intended to be interpreted to include the preferred embodiments as well as all changes and modifications falling within the scope of the present invention.

[0110] Obviously, those skilled in the art can make various changes and deformations to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and deformations of the present invention fall within the scope of the claims of the present invention and their equivalent technologies, the present invention also intends to include these changes and deformations.

Claims

1. A method for transforming abandoned geothermal wells in a mining area, characterized in that, It includes the following steps: Seal the wellhead, cracks and damaged parts of the well wall of the abandoned geothermal well in the mining area; Install thermal insulation materials on the well wall of the sealed abandoned geothermal well; Select corresponding heat storage materials according to the geothermal gradient and corresponding well depth of the abandoned geothermal well, and obtain the laying amount of heat storage materials based on the volume of the abandoned geothermal well; Arrange the heat storage materials in the abandoned geothermal well after installing thermal insulation materials according to the laying amount, set up a buried pipe heat exchanger on the inner wall of the heat storage materials, and connect the buried pipe heat exchanger to the ground system; the ground system includes a temperature control system and a domestic water system, and the temperature control system is used to obtain the stored heat of the heat storage materials, and convert the external electric energy into heat energy and store it in the heat storage materials during non-heating periods or when the stored heat is less than a preset value; during the heating period, transfer the stored heat to the domestic water system through the buried pipe heat exchanger.

2. The transformation method of an abandoned geothermal well in a mining area according to claim 1, characterized in that The selection of corresponding heat storage materials according to the geothermal gradient and well depth includes: Obtain the geothermal gradient of the abandoned geothermal well through the following formula: In the formula, G is the geothermal gradient, ΔZ is the depth, and ΔT1 is the temperature difference between the rock and soil at the corresponding depth; When the geothermal gradient of the abandoned geothermal well is 10 - 25 °C and its depth is 0 m - 400 m, use an organic material with a melting point lower than 60 °C as the heat storage material; When the geothermal gradient of the abandoned geothermal well is 20 - 35 °C and its depth is 400 m - 1500 m, use a composite phase change material with a melting point between 60 - 150 °C as the heat storage material; When the geothermal gradient of the abandoned geothermal well is above 35 °C and its depth is above 1500 m, use a high-temperature molten salt material with a melting point between 150 - 500 °C as the heat storage material.

3. The transformation method of an abandoned geothermal well in a mining area according to claim 1, characterized in that, The obtaining of the laying amount of heat storage materials based on the volume of the abandoned geothermal well, the laying amount is specifically as follows: V = π * r 2 * H; M = ρ * V; In the formula, V is the volume of the well body, r is the wellhead radius, H is the well depth, M is the mass of the laid heat storage materials, and ρ is the density of the heat storage materials.

4. The transformation method of an abandoned geothermal well in a mining area according to claim 1, characterized in that, The temperature control system is used to obtain the stored heat of the heat storage materials, and specifically includes the following steps: Obtain the heat loss of the heat storage materials; Q loss = k * A * ΔT3 * t / d; Where Q loss is the heat loss, K is the thermal conductivity of the thermal insulation material, A is the wellbore area, ΔT3 is the temperature difference between the heat storage material and the wellbore, t is the time, and d is the thickness of the thermal insulation material; Obtain the heat of the heat storage materials; E = Q s -Q d ; where E is the heat in the current heat storage device, and Q s is the input heat, and Q d is the output heat; Obtain the heat storage efficiency through the heat of the heat storage materials and the heat loss; In the formula, η is the heat storage efficiency.

5. The transformation method of an abandoned geothermal well in a mining area as described in claim 1, characterized in that, The preset value is 5% - 10%.

6. The transformation method of an abandoned geothermal well in a mining area according to claim 1, characterized in that, There is a backfill material between the heat storage materials and the buried pipe heat exchanger.

7. The transformation method of an abandoned geothermal well in a mining area according to claim 1, characterized in that, The circulating working fluid of the buried pipe heat exchanger is water, and the domestic water system includes: A purification and filtration device, whose input end is connected to an output end of the buried pipe heat exchanger through a control valve, and is used to filter the hot water output by the buried pipe heat exchanger; A supplementary water tank, whose input end is connected to the output end of the purification and filtration device, and is used to store the filtered hot water; A heat pump, whose input end is connected to another output end of the buried pipe heat exchanger through a control valve, and is used to heat the hot water output by the buried pipe heat exchanger; The output ends of the supplementary water tank and the heat pump are connected to the input end of the user side, and the output end of the user side is connected to the input end of the buried pipe heat exchanger.

8. A transformation system for abandoned geothermal wells in a mining area, characterized in that, It includes: A sealing module, which is used to seal the wellhead, cracks and damaged parts of the well wall of the abandoned geothermal well in the mining area; An installation module, which is used to install thermal insulation materials on the well wall of the sealed abandoned geothermal well; A selection module, configured to select a corresponding heat storage material according to the geothermal temperature gradient and the corresponding well depth of the abandoned geothermal well, and obtain the laying amount of the heat storage material based on the volume of the abandoned geothermal well; A connection module, configured to arrange the heat storage material in the abandoned geothermal well after installing the thermal insulation material according to the laying amount, and set a buried pipe heat exchanger on the inner wall of the heat storage material, and connect the buried pipe heat exchanger to the ground system; the ground system includes a temperature control system and a domestic water system, and the temperature control system is configured to obtain the stored heat of the heat storage material, and convert the external electric energy into heat energy and store it in the heat storage material during the non-heating period or when the stored heat is less than a preset value; during the heating period, transfer the stored heat to the domestic water system through the buried pipe heat exchanger.

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