Dynamic heat measuring instrument for middle-deep geothermal heat exchange well

Abstract

The application provides a kind of middle deep geothermal heat exchange well dynamic heat measuring instrument, mainly relates to geothermal utilization equipment technical field, to solve the technical problems of low heat measurement precision, poor real-time, lack of system linkage control ability of existing heat exchange well.The measuring instrument includes downhole monitoring unit, ground monitoring unit and linkage control unit;Downhole monitoring unit contains double-casing temperature sensor array, high-precision electromagnetic flowmeter and data acquisition transmission module, can real-time acquisition fluid temperature and flow data at different depths;Ground monitoring unit contains well source side / user side heat meter, working condition identification module and data processing display terminal, realize ground and downhole data collaborative acquisition, dynamic heat calculation.The application effectively improves the measurement accuracy through two-dimensional collaborative monitoring, supports working condition adaptive matching, can optimize the system comprehensive energy efficiency ratio, operation and maintenance is convenient, suitable for various middle deep geothermal "heat extraction without water" heat exchange system dynamic heat measurement and energy efficiency regulation.

Description

Technical Field

[0001] This invention mainly relates to the field of ground source heat pump equipment technology, specifically a dynamic heat measurement instrument for medium-deep geothermal heat exchange wells. Background Technology

[0002] Medium-deep geothermal energy, as a clean and sustainable new energy source, utilizes "heat extraction without water extraction" technology to extract underground heat energy through downhole heat exchangers. It is widely used in building heating, industrial heating, and other fields, offering significant environmental and energy-saving advantages. Dynamic heat measurement is a core component of energy efficiency assessment, operating condition control, and energy consumption metering for medium-deep geothermal heat exchange systems, directly affecting the system's operational stability and energy-saving performance.

[0003] Existing technologies for measuring the dynamic heat of medium-deep geothermal wells have many shortcomings and are difficult to meet the needs of actual engineering. The specific problems are as follows: Low measurement accuracy and poor coverage: Traditional measurement methods mostly use single-point temperature and flow sensors, which can only collect data from a single depth downhole or a single node on the surface. They cannot fully reflect the changes in fluid temperature gradient and fluid flow state at different depths downhole. Due to the limitations of the measurement points, large errors can easily occur in the heat transfer calculation, making it difficult to achieve high-precision measurement. Insufficient real-time performance and weak anti-interference capability: The environment inside the well is complex, with problems such as high temperature, high pressure, fluid turbulence, and scale adhesion, which can easily lead to sensor signal distortion and data transmission delay. Existing equipment is unable to achieve synchronous acquisition and real-time processing of data between the well and the surface, and cannot accurately capture dynamic changes in the heat exchange process. Lack of system linkage capability: Most existing measurement equipment operates independently and can only complete data acquisition and display. It cannot be linked with heat pump units, circulating pumps, user-side heating systems, etc., making it difficult to adaptively adjust the system operating conditions based on measurement results and unable to support system energy efficiency optimization. High maintenance costs and poor applicability: Some high-precision measurement equipment has a complex structure, is difficult to install, and does not have remote fault diagnosis and data access functions. The maintenance workload is large and the cost is high. At the same time, it is difficult to adapt to the measurement needs of different heating conditions (such as full heating in extreme cold and separate heating for different buildings).

[0004] To address the shortcomings of the existing technologies, there is an urgent need for a dynamic heat measurement instrument for medium-deep geothermal heat exchange wells that can achieve coordinated monitoring between downhole and surface environments, has high precision, strong real-time performance, system linkage and control capabilities, and is easy to operate and maintain. Summary of the Invention

[0005] To address the shortcomings of existing technologies, this invention provides a dynamic heat measurement instrument for medium-deep geothermal heat exchange wells, enabling dual-dimensional collaborative monitoring of downhole and surface conditions, improving the accuracy and real-time performance of dynamic heat measurement, and possessing adaptive identification of operating conditions and system linkage control functions, thereby reducing operation and maintenance costs and optimizing the energy efficiency of the heat exchange system.

[0006] To achieve the above objectives, the present invention employs the following technical solution: A dynamic heat measurement instrument for medium-deep geothermal heat exchange wells includes a downhole monitoring unit, a surface monitoring unit, and a linkage control unit, which are interconnected via armored cables and communication lines. The downhole monitoring unit collects temperature and flow data of the downhole fluid and transmits it to the surface monitoring unit. The surface monitoring unit receives downhole data, collects heat-related data of the surface-side heat exchange system, and performs dynamic heat exchange calculation and operating condition identification. The linkage control unit adaptively regulates the heat pump unit and circulating pump based on the monitoring and calculation results.

[0007] The downhole monitoring unit includes a dual-tube temperature sensor array, a high-precision electromagnetic flowmeter, and a data acquisition and transmission module. The dual-tube temperature sensor array consists of at least three high-precision platinum resistance temperature sensors, using a dual-tube encapsulation structure, and is arranged at different depths in the inner tube production heat flow channel and the outer tube annular fluid channel, spaced 5-10m apart. The high-precision electromagnetic flowmeter is installed at the inner tube inlet, with a measurement range of 0.5-10 m³ / h and an accuracy class of not less than 0.2. The data acquisition and transmission module is electrically connected to the dual-tube temperature sensor array and the high-precision electromagnetic flowmeter, and has a built-in data amplifier, A / D converter, and wireless transmission module, and has a data caching function.

[0008] The ground monitoring unit includes a well-source side heat meter, a user-side heat meter, an operating condition identification module, and a data processing and display terminal. Both the well-source side and user-side heat meters are ultrasonic heat meters with an accuracy class of no less than 0.2, installed on the inlet and outlet pipes of the evaporator and condenser sides of the heat pump unit, respectively. The operating condition identification module incorporates an ambient temperature sensor and an operating condition judgment algorithm, automatically identifying three operating conditions: extreme cold full-supply, normal full-supply, and separate heating for each building. The data processing and display terminal is an industrial touchscreen with a built-in data processing chip and dedicated computing software, supporting data storage, querying, and export, with a storage time of no less than one year.

[0009] The dynamic heat exchange is calculated using the following formula: In the formula: Q is the dynamic heat exchange (kW), ρ is the density of the heat exchange fluid (kg / m³), c is the specific heat capacity of the heat exchange fluid (kJ / (kg·℃)), q is the instantaneous flow rate (m³ / h), and ΔT is the temperature difference between the supply and return water (℃); the data processing and display terminal simultaneously calculates and displays the system energy efficiency ratio COP, COP = cumulative heat on the user side / power consumption of the heat pump unit.

[0010] The linkage control unit includes an adaptive operating condition control module, an abnormal operating condition alarm module, and a remote communication module. The adaptive operating condition control module can automatically adjust the water supply temperature setpoint and the speed of the circulating pump of the heat pump unit according to the operating condition identification result. The abnormal operating condition alarm module has a built-in threshold setting unit, which can trigger an audible and visual alarm and push alarm information to the operation and maintenance personnel terminal. The remote communication module supports 4G / 5G and Ethernet communication to realize remote data access, parameter modification, and operation and maintenance control.

[0011] The control strategy of the adaptive control module is as follows: for extreme cold full supply conditions (ambient temperature ≤ -10℃), the heat pump water supply temperature is set to 44℃ and the circulation pump speed is increased; for normal full supply conditions (-10℃ < ambient temperature ≤ 5℃), the heat pump water supply temperature is set to 40℃ and the circulation pump speed is optimized; for building-by-building heating conditions (ambient temperature > 5℃), the user-side circulation pump speed is adjusted to achieve on-demand flow distribution.

[0012] The dual-tube temperature sensor array has a packaging structure that is resistant to high temperature, high pressure, and scale adhesion, making it suitable for high-temperature and high-pressure environments inside wells. The armored cable is also resistant to high temperature and high pressure and is used to enable data transmission between the well and the surface.

[0013] The downhole monitoring unit is integrated between the inner and outer pipes of the medium-deep geothermal heat exchange well, while the surface monitoring unit and linkage control unit are located in the surface control room.

[0014] A dynamic heat measurement instrument for medium-deep geothermal heat exchange wells includes a downhole monitoring unit, a surface monitoring unit, and a linkage control unit. The three units are electrically connected and exchange data via armored cables and communication lines. The specific structure is as follows: (a) Downhole monitoring unit The downhole monitoring unit is integrated between the inner and outer pipes of a medium-deep geothermal heat exchange well. It is used to collect real-time temperature and flow rate data of fluids at different depths downhole and transmit the collected data to the surface monitoring unit. It includes: 1. Dual-tube temperature sensor array: Composed of at least 3 high-precision platinum resistance temperature sensors. The sensors adopt a dual-tube encapsulation structure and are respectively arranged at different depths (5-10m apart) in the inner tube production heat flow channel and the outer tube annular fluid channel. It is used to synchronously collect real-time temperature data of different depths and different fluid channels in the well. The encapsulation structure has the characteristics of high temperature resistance, high pressure resistance and scale adhesion resistance, and is suitable for complex well environments. 2. High-precision electromagnetic flowmeter: installed at the inlet of the inner pipe, made of corrosion-resistant and wear-resistant material, with a measurement range of 0.5-10 m³ / h and an accuracy class of not less than 0.2. It is used to measure the flow rate data of the heat flow in the inner pipe in real time and can effectively resist the interference of fluid turbulence and impurities in the well. 3. Data Acquisition and Transmission Module: Electrically connected to the dual-tube temperature sensor array and high-precision electromagnetic flowmeter, with built-in data amplifier, A / D converter and wireless transmission module, it can convert the acquired analog signals into digital signals and transmit them to the ground monitoring unit through armored cable (high temperature and high pressure resistant). It also has a data buffering function to prevent data loss.

[0015] (ii) Ground monitoring unit The ground monitoring unit is located in the ground control room and is used to receive data transmitted from the downhole monitoring unit, collect heat-related data of the surface-side heat exchange system, and perform dynamic heat exchange calculations, operating condition identification, and data display. It includes: 1. Heat meter on the well source side and heat meter on the user side: The heat meter on the well source side is installed on the inlet and outlet pipes on the evaporator side of the heat pump unit, and the heat meter on the user side is installed on the inlet and outlet pipes on the condenser side of the heat pump unit. Both are ultrasonic heat meters with an accuracy class of not less than 0.2. They can collect the supply water temperature, return water temperature, instantaneous flow rate and cumulative heat data of the corresponding side in real time. Operating Condition Identification Module: With a built-in ambient temperature sensor and operating condition judgment algorithm, it can collect ambient temperature data in real time and automatically identify the operating conditions of the heat exchange system based on the user's heating needs (full-scale heating / partial-scale heating). These include three typical operating conditions: extreme cold full-scale heating (ambient temperature ≤ -10℃, heating of the entire building on the user's side), normal full-scale heating (-10℃ < ambient temperature ≤ 5℃, heating of the entire building on the user's side), and partial-scale heating (ambient temperature > 5℃, heating of some floors on the user's side). Data processing and display terminal: It adopts an industrial touch screen, with built-in data processing chip and dedicated computing software. It can receive all data transmitted from downhole monitoring unit, well source side heat meter, and user side heat meter, calculate dynamic heat exchange according to preset formula, and display instantaneous heat exchange, cumulative heat exchange, system energy efficiency ratio (COP), temperature / flow data of each measuring point. It supports data storage, query and export functions, and the storage time is not less than 1 year.

[0016] The dynamic heat exchange is calculated using the following formula: In the formula: Q is the dynamic heat exchange (kW), ρ is the density of the heat exchange fluid (kg / m³), c is the specific heat capacity of the heat exchange fluid (kJ / (kg·℃)), q is the instantaneous flow rate (m³ / h), and ΔT is the temperature difference between the supply and return water (℃); the system energy efficiency ratio COP = cumulative heat on the user side / power consumption of the heat pump unit.

[0017] (III) Linkage Control Unit The linkage control unit is electrically connected to the ground monitoring unit and communicates with the control modules of the heat pump unit and circulating pump via a communication interface. It is used to adaptively adjust the heat exchange system based on the measurement results and operating condition identification results from the ground monitoring unit. This includes: Adaptive Control Module: Based on the operating conditions identified by the operating condition identification module, the module automatically adjusts the setpoint of the heat pump unit's water supply temperature and the speed of the circulating pump. For example, under extremely cold full-supply conditions, the heat pump water supply temperature is set to 44℃, and the circulating pump speed is increased to enhance the heat exchange intensity in the well. Under normal full-supply conditions, the heat pump water supply temperature is set to 40℃, and the circulating pump speed is optimized to reduce energy consumption. Under separate heating conditions for different buildings, the circulating pump speed on the user side is adjusted to achieve on-demand flow distribution. Abnormal operating condition alarm module: Built-in threshold setting unit, which can preset the normal threshold range of temperature, flow rate and energy consumption. When the monitored data (such as abnormal rise / fall of downhole temperature, flow rate lower / higher than the set value, abnormally low system energy efficiency ratio) deviates from the threshold, an audible and visual alarm is immediately triggered, and the alarm information is pushed to the mobile terminal of the operation and maintenance personnel. The alarm information includes abnormal measurement point, abnormal data and abnormal type. Remote communication module: Supports 4G / 5G and Ethernet communication. Maintenance personnel can access the monitoring data of the measuring instrument, modify the control parameters, and view alarm records through remote terminals (computers, mobile phones) to realize remote operation and control.

[0018] Compared with the prior art, the beneficial effects of the present invention are: High measurement accuracy and wide coverage: Temperature acquisition at different depths and in different fluid channels is achieved through a downhole dual-casing temperature sensor array. Combined with downhole and surface dual-dimensional flow and temperature monitoring, the error of a single measuring point is eliminated, and the dynamic heat metering accuracy is improved to within ±2%, which can comprehensively reflect the dynamic changes of the heat exchange process. High real-time performance and excellent anti-interference capability: The downhole data acquisition and transmission module adopts high-precision signal processing technology and is combined with armored cable transmission to effectively avoid interference from the complex environment inside the well, realize synchronous acquisition, real-time processing and display of downhole and surface data, and the data transmission delay is ≤1s; The adaptive operating conditions and energy efficiency optimization are significant: the operating condition identification module can automatically identify different operating conditions and link the control unit to realize the adaptive regulation of the heat pump unit and the circulating pump, so that the heat exchange system always operates in the best condition. Compared with the existing technology, the overall energy efficiency ratio of the system is improved by more than 15%, and energy consumption is greatly reduced. Convenient operation and maintenance, wide applicability: It supports remote data access, fault diagnosis and alarm, which reduces the workload and cost of on-site operation and maintenance; the equipment has a modular design, is easy to install, and can be adapted to medium-deep geothermal heat exchange wells of different depths and specifications, while being compatible with various working conditions such as full supply and separate building heating. Strong data integrity: It has complete data storage, query and export functions, and can store monitoring data for a long time, providing reliable data support for energy efficiency assessment, fault diagnosis and optimization and upgrading of heat exchange system. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the overall system architecture of the dynamic heat measurement instrument for deep geothermal heat exchange wells in this invention; Figure 2 This is a schematic diagram of the installation structure of the downhole monitoring unit of the present invention; Figure 3 This is a schematic diagram of the connection structure between the ground monitoring unit and the linkage control unit of the present invention; Figure 4 This is a schematic diagram of the dynamic heat exchange, temperature and flow monitoring curves under typical operating conditions of the present invention. Figure 5 This is a schematic diagram of some monitoring data from the present invention; Figure 6 This is a schematic diagram of the heating process after heat exchange according to the present invention; Figure 7 This is a schematic diagram of the geothermal heat extraction principle of the present invention. Detailed Implementation

[0020] The present invention will be further described in conjunction with the accompanying drawings and specific embodiments. It should be understood that these embodiments are for illustrative purposes only and are not intended to limit the scope of the invention. Furthermore, it should be understood that after reading the teachings of this invention, those skilled in the art can make various alterations or modifications to the invention, and these equivalent forms also fall within the scope defined in this application.

[0021] Combined with appendix Figures 1-7A dynamic heat measurement instrument for medium-deep geothermal heat exchange wells includes a downhole monitoring unit, a surface monitoring unit, and a linkage control unit, which are interconnected via armored cables and communication lines. The downhole monitoring unit is used to collect temperature and flow data of the downhole fluid and transmit them to the surface monitoring unit. The surface monitoring unit is used to receive downhole data, collect heat-related data of the surface-side heat exchange system, and complete dynamic heat exchange calculation and operating condition identification. The linkage control unit is used to adaptively regulate the heat pump unit and circulating pump based on the monitoring and calculation results.

[0022] The downhole monitoring unit includes a dual-tube temperature sensor array, a high-precision electromagnetic flowmeter, and a data acquisition and transmission module. The dual-tube temperature sensor array consists of at least one high-precision platinum resistance temperature sensor, using a dual-tube encapsulation structure, and is arranged at different depths in the inner tube production heat flow channel and the outer tube annular fluid channel, spaced 5-10m apart. The high-precision electromagnetic flowmeter is installed at the inner tube inlet, with a measurement range of 0.5-10 m³ / h and an accuracy class of not less than 0.2. The data acquisition and transmission module is electrically connected to the dual-tube temperature sensor array and the high-precision electromagnetic flowmeter, and has a built-in data amplifier, A / D converter, and wireless transmission module, and has a data buffering function.

[0023] The ground monitoring unit includes a well-source side heat meter, a user-side heat meter, an operating condition identification module, and a data processing and display terminal. Both the well-source side heat meter and the user-side heat meter are ultrasonic heat meters with an accuracy class of at least [insert accuracy level here], and are installed on the inlet and outlet pipes of the evaporator and condenser sides of the heat pump unit, respectively. The operating condition identification module has a built-in ambient temperature sensor and operating condition judgment algorithm, which can automatically identify three operating conditions: extreme cold full supply, normal full supply, and building-by-building heating. The data processing and display terminal is an industrial touchscreen with a built-in data processing chip and dedicated computing software, supporting data storage, querying, and export, with a storage time of at least one year.

[0024] The dynamic heat exchange is calculated using the following formula: In the formula: Q is the dynamic heat exchange capacity in kW, ρ is the density of the heat exchange fluid in kg / m³, c is the specific heat capacity of the heat exchange fluid in kJ / (kg·℃), q is the instantaneous flow rate in m³ / h, and ΔT is the temperature difference between the supply and return water in ℃; the data processing and display terminal simultaneously calculates and displays the system energy efficiency ratio COP, COP = cumulative heat on the user side / power consumption of the heat pump unit.

[0025] The linkage control unit includes an adaptive operating condition control module, an abnormal operating condition alarm module, and a remote communication module. The adaptive operating condition control module can automatically adjust the water supply temperature setpoint and the speed of the circulating pump of the heat pump unit according to the operating condition identification result. The abnormal operating condition alarm module has a built-in threshold setting unit, which can trigger an audible and visual alarm and push alarm information to the operation and maintenance personnel terminal. The remote communication module supports 4G / 5G and Ethernet communication to realize remote data access, parameter modification, and operation and maintenance control.

[0026] The control strategy of the adaptive control module is as follows: for extreme cold full-supply conditions with an ambient temperature ≤ -10℃, the heat pump water supply temperature is set to 44℃, and the circulation pump speed is increased; for normal full-supply conditions with an ambient temperature ≤ 5℃, the heat pump water supply temperature is set to 40℃, and the circulation pump speed is optimized; for building-specific heating conditions with an ambient temperature > 5℃, the user-side circulation pump speed is adjusted to achieve on-demand flow distribution.

[0027] The dual-tube temperature sensor array has a packaging structure that is resistant to high temperature, high pressure, and scale adhesion, making it suitable for high-temperature and high-pressure environments inside wells. The armored cable is also resistant to high temperature and high pressure and is used to enable data transmission between the well and the surface.

[0028] The downhole monitoring unit is integrated between the inner and outer pipes of the medium-deep geothermal heat exchange well, while the surface monitoring unit and linkage control unit are located in the surface control room.

[0029] Example 1 This embodiment provides a dynamic heat measurement instrument for a medium-deep geothermal heat exchange well, applied to a medium-deep geothermal heat exchange well with a depth of 1500m, an inner pipe diameter of 150mm, and an outer pipe diameter of 273mm. Clean water is used as the heat exchange fluid. The specific implementation process is as follows: (I) Installation and Deployment 1. Installation of downhole monitoring unit: The dual-tube temperature sensor array (4 platinum resistance temperature sensors, accuracy class 0.1) is deployed at depths of 500m, 800m, 1200m, and 1500m, respectively, with 2 deployed in the inner tube production heat flow channel and 2 deployed in the outer tube annular fluid channel; a high-precision electromagnetic flowmeter (measuring range 0.5-10m³ / h, accuracy class 0.2) is installed at the inlet of the inner tube, integrated and fixed with the temperature sensor array and data acquisition and transmission module, and laid along the well wall to the surface control room via armored cable; 2. Ground monitoring unit installation: Install well-source-side ultrasonic heat meters on the inlet and outlet pipes of the evaporator side of the heat pump unit, and install user-side ultrasonic heat meters on the inlet and outlet pipes of the condenser side (both with an accuracy of 0.2 class); the operating condition identification module and the ambient temperature sensor (measuring range -40℃~80℃) are installed outside the ground control room, and the data processing and display terminal (15-inch industrial touch screen) is arranged inside the control room and electrically connected to each heat meter and operating condition identification module; 3. Installation of linkage control unit: Connect the linkage control unit to the data processing and display terminal electrically, and connect it to the control module of the heat pump unit and the circulating pump through the RS485 communication interface. Complete the wiring and debugging to ensure the interconnection between the downhole unit, the surface unit, and the linkage unit.

[0030] (II) Measurement and Control Process 1. Data Acquisition: The dual-tube temperature sensor array of the downhole monitoring unit collects fluid temperature data at different depths in real time, and the electromagnetic flowmeter collects heat flow data of the inner tube. After being converted into digital signals by the data acquisition and transmission module, the data is transmitted to the surface monitoring unit through the armored cable. At the same time, the heat meters on the well source side and the user side collect the temperature, flow rate and heat data of the supply and return water on the surface side, and the operating condition identification module collects the ambient temperature data. 2. Operating Condition Identification and Data Processing: The data processing and display terminal of the ground monitoring unit receives all collected data. The operating condition identification module automatically identifies the operating condition based on the ambient temperature and user-side heating demand; the data processing module uses formulas... Calculate the dynamic heat exchange (where ρ=1000kg / m³, c=4.2kJ / (kg·℃)) and the system energy efficiency ratio COP, and display all data on the display terminal in real time; 3. Interlocking Control: The interlocking control unit automatically adjusts the heat pump unit and circulating pump based on the operating condition identification results and measurement data. (1) Extreme cold full supply condition (ambient temperature ≤ -10℃): Set the heat pump supply water temperature to 44℃, increase the circulation pump speed to 90% of the rated speed, strengthen the heat exchange in the well, and ensure the heating effect on the user side. (2) Normal full supply operation (-10℃ < ambient temperature ≤ 5℃): Set the heat pump water supply temperature to 40℃ and adjust the circulation pump speed to 70%-80% of the rated speed to achieve energy efficiency optimization; (3) Heating in separate floors (ambient temperature > 5℃): Adjust the speed of the circulating pump on the user side according to the heating demand on the user side, and distribute the flow rate of each floor to avoid energy waste; 4. Anomaly Handling: When the monitored data deviates from the preset threshold (such as downhole temperature > 80℃, flow rate < 0.5m³ / h, COP < 2.5), the abnormal operating condition alarm module immediately triggers an audible and visual alarm and pushes the alarm information to the mobile phone of the operation and maintenance personnel. The operation and maintenance personnel can view the anomaly details through the remote terminal and troubleshoot the fault in a timely manner.

[0031] (III) Verification of Application Effect The measuring instrument of this embodiment was applied to a medium-deep geothermal heating project. After three months of operation, the results showed that the dynamic heat measurement accuracy was stable within ±1.8%, and the data transmission delay was ≤0.8s. Compared with existing measuring equipment, the overall energy efficiency ratio of the heat exchange system was improved by 18%, and the average monthly energy consumption was reduced by 16%. Maintenance personnel can complete data monitoring and troubleshooting through remote terminals, reducing maintenance costs by 30% and fully meeting the project's measurement and control needs.

[0032] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A dynamic heat measurement instrument for medium-deep geothermal heat exchange wells, characterized in that, The system includes a downhole monitoring unit, a surface monitoring unit, and a linkage control unit, which are interconnected via armored cables and communication lines. The downhole monitoring unit collects temperature and flow data of the downhole fluid and transmits it to the surface monitoring unit. The surface monitoring unit receives downhole data, collects heat-related data of the surface-side heat exchange system, and performs dynamic heat exchange calculations and operating condition identification. The linkage control unit adaptively regulates the heat pump unit and circulating pump based on the monitoring and calculation results.

2. The dynamic heat measurement instrument for medium-deep geothermal heat exchange wells according to claim 1, characterized in that, The downhole monitoring unit includes a dual-tube temperature sensor array, a high-precision electromagnetic flowmeter, and a data acquisition and transmission module. The dual-tube temperature sensor array consists of at least three high-precision platinum resistance temperature sensors, using a dual-tube encapsulation structure, and is arranged at different depths in the inner tube production heat flow channel and the outer tube annular fluid channel, spaced 5-10m apart. The high-precision electromagnetic flowmeter is installed at the inner tube inlet, with a measurement range of 0.5-10 m³ / h and an accuracy class of not less than 0.

2. The data acquisition and transmission module is electrically connected to the dual-tube temperature sensor array and the high-precision electromagnetic flowmeter, and has a built-in data amplifier, A / D converter, and wireless transmission module, and has a data caching function.

3. The dynamic heat measurement instrument for medium-deep geothermal heat exchange wells according to claim 1, characterized in that, The ground monitoring unit includes a well-source side heat meter, a user-side heat meter, an operating condition identification module, and a data processing and display terminal. Both the well-source side and user-side heat meters are ultrasonic heat meters with an accuracy class of no less than 0.2, installed on the inlet and outlet pipes of the evaporator and condenser sides of the heat pump unit, respectively. The operating condition identification module incorporates an ambient temperature sensor and an operating condition judgment algorithm, automatically identifying three operating conditions: extreme cold full-supply, normal full-supply, and separate heating for each building. The data processing and display terminal is an industrial touchscreen with a built-in data processing chip and dedicated computing software, supporting data storage, querying, and export, with a storage time of no less than one year.

4. The dynamic heat measurement instrument for medium-deep geothermal heat exchange wells according to claim 3, characterized in that, The dynamic heat exchange is calculated using the following formula: In the formula: Q is the dynamic heat exchange (kW), ρ is the density of the heat exchange fluid (kg / m³), c is the specific heat capacity of the heat exchange fluid (kJ / (kg·℃)), q is the instantaneous flow rate (m³ / h), and ΔT is the temperature difference between the supply and return water (℃); the data processing and display terminal simultaneously calculates and displays the system energy efficiency ratio COP, COP = cumulative heat on the user side / power consumption of the heat pump unit.

5. The dynamic heat measurement instrument for medium-deep geothermal heat exchange wells according to claim 1, characterized in that, The linkage control unit includes an adaptive operating condition control module, an abnormal operating condition alarm module, and a remote communication module. The adaptive operating condition control module can automatically adjust the water supply temperature setpoint and the speed of the circulating pump of the heat pump unit according to the operating condition identification result. The abnormal operating condition alarm module has a built-in threshold setting unit, which can trigger an audible and visual alarm and push alarm information to the operation and maintenance personnel terminal. The remote communication module supports 4G / 5G and Ethernet communication to realize remote data access, parameter modification, and operation and maintenance control.

6. The dynamic heat measurement instrument for medium-deep geothermal heat exchange wells according to claim 5, characterized in that, The control strategy of the adaptive control module is as follows: in extreme cold full supply conditions (ambient temperature ≤ -10℃), the heat pump supply water temperature is set to 44℃, and the circulation pump speed is increased. In normal full-supply operation (-10℃ < ambient temperature ≤ 5℃), the heat pump supply temperature is set to 40℃, and the circulation pump speed is optimized; in building-by-building heating operation (ambient temperature > 5℃), the user-side circulation pump speed is adjusted to achieve on-demand flow distribution.

7. The dynamic heat measurement instrument for medium-deep geothermal heat exchange wells according to claim 2, characterized in that, The dual-tube temperature sensor array has a packaging structure that is resistant to high temperature, high pressure, and scale adhesion, making it suitable for high-temperature and high-pressure environments inside wells. The armored cable is also resistant to high temperature and high pressure and is used to enable data transmission between the well and the surface.

8. The dynamic heat measurement instrument for medium-deep geothermal heat exchange wells according to claim 1, characterized in that, The downhole monitoring unit is integrated between the inner and outer pipes of the medium-deep geothermal heat exchange well, while the surface monitoring unit and linkage control unit are located in the surface control room.

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