Ground source heat pump system multi-working-condition cooperative control and vertical buried pipe construction method

Abstract

The invention relates to the technical field of ground source heat pump engineering, and particularly discloses a ground source heat pump system multi-working-condition cooperative control and vertical buried pipe construction method which comprises vertical buried pipe construction and system multi-working-condition control, specifically, in the construction stage, through a theodolite, accurate positioning is conducted, and 4 m * 4 m interval hole sites are located; a 150mm drill bit is used for drilling, and the depth is 103m (100m effective + 3m through hole); the double-U-pipe pressure test and pipe lowering are performed, the pressure test is performed under 1.5 MPa, and the positioning pipe clamp is separated for fixing; primary pulp backfilling is conducted, pressure is monitored in real time, and construction quality is ensured; in the control stage, heat is supplied in winter, the number of heat pumps is adjusted according to the temperature and the load rate, cold is supplied in summer, system switching is conducted according to the heat discharge amount and the soil temperature, energy storage is conducted, and energy consumption is reduced through cooperative control over off-peak electricity heat storage / cold storage. The problems that existing buried pipe construction is not solid and system working condition switching is low in efficiency are solved, the heat exchange efficiency is improved by 15%-20%, energy consumption is reduced by 25%-30%, and the system is suitable for building ground source heat pump projects.

Description

Technical Field

[0001] This invention relates to the field of ground source heat pump engineering technology, and in particular to a method for multi-condition coordinated control of ground source heat pump systems and construction of vertical buried pipes. Background Technology

[0002] Ground source heat pump systems are widely used in building cooling and heating due to their energy-saving and environmentally friendly characteristics, but existing technologies have the following problems: During the construction of vertical buried pipes, the drilling is prone to tilting and hole deviation, which leads to a decrease in the heat exchange efficiency of the buried pipe; during backfilling, it is easy to be compacted, forming voids that affect heat exchange. During the process of laying underground pipes, the pipes are easily damaged by friction or misposition, resulting in the scrapping of the pipe section; When the system is running, the switching between multiple operating conditions (heating, cooling, and energy storage) is inflexible, the pump frequency and unit start-up and shutdown lack coordinated control, and the energy consumption is high. During summer cooling season, the lack of clear guidelines for switching between the underground pipe system and the cooling water system can easily lead to soil temperature imbalance and affect the long-term operational stability of the system. Summary of the Invention

[0003] The purpose of this invention is to solve the problems in existing underground pipe construction, such as easy tilting and hole deviation during drilling, easy damage and inaccurate positioning of pipes during installation, and voids during backfilling; as well as the inflexible switching between multiple working conditions and the lack of clear switching criteria during system operation.

[0004] To achieve the above objectives, the present invention provides a method for constructing vertical buried pipes for a ground source heat pump system, comprising the following steps: S1. Measurement and layout and borehole positioning: Select benchmark points based on the building and measure and lay out the lines. Design the drilling spacing based on the measurement and layout results, and mark the positions of all boreholes according to the designed spacing. S2. Drilling construction: During the drilling process, control the drilling rig chassis to be horizontal and the tower to be vertical, and record the soil conditions. After drilling to the effective depth, continue drilling to form a through hole, and simultaneously excavate the mud pit and clean up the mud. S3. Construction of underground risers: Double U-pipes are used. Pressure test is performed before the pipe is laid. The pipe is laid at a uniform speed and the double U-pipes are fixed with separation positioning pipe clamps. Pipe sections are reserved on the ground and fixed. S4. Backfilling of buried pipes: Use slurry to backfill from bottom to top until it overflows, and then fill it again after it settles. Monitor the pipe pressure in real time during the backfilling process. If the pressure is abnormal, stop backfilling and investigate. Seal the pipe opening after it is qualified. Backfilling of buried pipes can also utilize circulating mud from adjacent boreholes.

[0005] Preferably, in step S1, the theodolite is used for the measurement and setting out, the drilling spacing is designed to be 4m×4m, and wooden stakes are set at the center points of all drilling locations. When there are underground obstacles at the marked borehole location, the design plan after adjusting the borehole location will be submitted to the design unit for approval. After the design unit approves it, the marked location of the borehole will be adjusted.

[0006] Preferably, in step S2, the drilling rig is equipped with a level, and the drill bit is 150mm or 200mm in size; the level of the drilling rig chassis is controlled to be ≤0.5mm / m, and the verticality of the tower is achieved by calibrating the verticality with a plumb bob; the effective drilling depth is 100m, and the through hole depth is 3m; the soil condition is recorded every 5m during the drilling process; the distance between the mud pit and the borehole is ≤5m; The specific steps for cleaning the mud are: cleaning the sand particles in the circulating mud in the mud pit in real time; flushing the hole with clean water for ≥10 minutes when the hole is clear, and stopping when there are no sand particles in the mud.

[0007] Preferably, in step S3, the double U-tube is a PE100 polyethylene double U-tube; a special pipe-laying tool is used when laying the pipe, and the spacing of the separation positioning pipe clamps is ≤3m; the length of the reserved pipe section on the ground is 0.5m-1.5m. The pressure test before pipe laying is as follows: before laying the pipe, test it with a pressure of 1.5MPa for 15 minutes. If the pressure drop is ≤3%, the pipe is qualified and pressure is maintained at 0.5MPa; if the pressure drop is >3%, the pipe is unqualified.

[0008] Preferably, the method for constructing vertical buried pipes in a ground source heat pump system further includes horizontal pipe construction, specifically: Dig a trench and lay fine sand, then test the horizontal pipe. After the test, lay the horizontal pipe in the trench, connect the horizontal pipe to the double U-pipe using an electrofusion sleeve, and backfill the horizontal pipe. The backfilling method for horizontal pipes is as follows: both sides of the pipe are backfilled simultaneously, and the top 50cm of the pipe is lightly compacted. The horizontal pipe pressure test is as follows: pressure 1.0MPa, stabilize pressure for 15min. If the pressure drop is ≤3%, the horizontal pipe is qualified; if the pressure drop is >3%, the horizontal pipe is unqualified.

[0009] Preferably, before the construction of vertical buried pipes, the drilling rig operators are given a special briefing, including: the drilling positioning error is ≤50mm and the drilling verticality deviation is ≤1‰; When the buried pipes arrive on site, their appearance and specifications shall be inspected. The appearance standards include: no bubbles or cracks. The sampling rate shall be 10% and no less than 1 pipe.

[0010] This invention also provides a multi-condition collaborative control method for a ground source heat pump system using the above-mentioned vertical buried pipe construction method, including the following control logic: S21. Winter heating condition: The number of heat pumps is controlled based on the user-side water supply temperature feedback value and the heat pump load rate. The system detects the current number of heat pumps in operation. If one heat pump is operating, the number of heat pumps is controlled based on the water supply temperature feedback value. If two heat pumps are operating, the number of heat pumps is controlled based on the heat pump load rate.

[0011] S22. Summer cooling operation: Monitor the heat dissipation of the buried pipe system into the ground and the soil temperature; Check whether the heat dissipation is less than the set heat dissipation value or the soil temperature is less than the set soil temperature value. If they are met, the electric chiller is grounded into the underground pipe system and two underground pipe circulation pumps are turned on. If they are not met, the electric chiller is switched to the cooling water system and the cooling tower fan automatically adjusts its frequency according to the cooling water outlet temperature = outdoor wet bulb temperature + 3℃. S23, Energy Storage Operation: Different control strategies are implemented according to the electricity consumption period; Check if the current time is between 23:00 and 7:00. If yes, execute the off-peak electricity strategy; otherwise, execute the peak electricity strategy. The off-peak electricity strategy is as follows: Detect whether the current mode is thermal storage or cold storage. If it is thermal storage, close the main valve on the user side and the bypass valve of the energy storage tank, open the differential pressure bypass valve and the upper inlet and lower outlet valve of the energy storage tank, run one heat pump, and check whether the outlet water temperature of the tank meets the set value of tank outlet water temperature - supply water temperature > 5℃ and lasts for 1 minute. If yes, stop the operation of the heat pump; if not, keep one heat pump running. If it is in cold storage mode, close the main valve on the user side and the bypass valve of the energy storage tank, open the differential pressure bypass valve and the lower inlet and upper outlet valve of the energy storage tank, run one heat pump / electric chiller, and check whether the outlet water temperature of the tank meets the set value of the supply water temperature - the outlet water temperature of the tank is >5℃ and lasts for 1 minute. If yes, stop the operation of the heat pump / electric chiller; if not, keep one heat pump / electric chiller running. The peak power strategy is to shut down the generating units and use energy storage tanks for cooling / heating.

[0012] Preferably, in step S21, controlling the number of heat pumps based on the water supply temperature feedback value specifically involves: Check if the water supply temperature feedback value meets the water supply temperature setpoint - feedback value > 1℃ and lasts for 10 minutes. If yes, add one heat pump; if not, keep one heat pump running. The specific method for controlling the number of heat pumps based on the heat pump load rate is as follows: Calculate the heat pump load rate and check if the heat pump load rate is less than 45% for 10 minutes. If so, shut down one heat pump; otherwise, keep both heat pumps running.

[0013] Preferably, in step S22, the control of the number of operating devices is as follows: Detect currently running equipment; If only one heat pump is running, check whether the heat pump meets the cooling demand. If it does, keep the heat pump running; otherwise, stop the heat pump and start the electric chiller. If one electric chiller is running, check whether the one electric chiller meets the cooling demand. If it does, keep it unchanged; if not, add one heat pump. If the system is operating with 1 electric chiller and 1 heat pump, check if the equipment load rate meets the requirement of load rate < reduce set value for 10 minutes. If yes, turn off 1 heat pump; otherwise, keep it unchanged. The range of the automatic frequency adjustment is 20-50Hz.

[0014] Preferably, in the collaborative control method, the underground pipe circulation pump and the user-side heat pump adopt frequency conversion control; The underground pipe circulation pump is linked with the heat pump in a 1:1 ratio during heating operation; when the chiller is connected to the power supply during cooling operation, two underground pipe circulation pumps are turned on, and the pump frequency adjustment range is 30-50Hz; the user-side pump adjusts its frequency according to the most unfavorable pressure difference at the end, with a range of 30-50Hz.

[0015] Preferably, in the energy storage condition described in step S23, the switching response time of the inlet and outlet water valves of the energy storage tank is ≤30s, the start-stop delay of the heat pump / electric chiller is ≤1min, and the energy storage efficiency is ≥85%; when running during off-peak electricity at night, the heat pump operates at 41 / 36℃ during heat storage and at 6 / 11℃ during cold storage.

[0016] The present invention employs the above-mentioned method for multi-condition coordinated control and vertical buried pipe construction of a ground source heat pump system, and its beneficial effects are as follows: (1) The drilling positioning error of this invention is ≤50mm, the verticality deviation is ≤1‰, and the backfill compaction is ≥95%, which avoids the underground pipe from going through holes and being damaged, improves the heat exchange efficiency by 15-20%, and significantly improves the construction quality. (2) The multi-condition collaborative control of the present invention reduces the energy consumption of water pumps by 25-30%, and the energy storage condition utilizes off-peak electricity, reducing operating costs by 30-35% and reducing energy consumption; (3) The switching basis of the summer cooling system of the present invention is clear, the soil temperature fluctuation is ≤2℃, the long-term operation failure rate of the system is reduced by 40%, and the system stability is enhanced; (4) This invention is applicable to ground source heat pump projects of different building scales. The construction parameters can be adjusted according to the project, and it has wide adaptability. Attached Figure Description

[0017] Figure 1 This is a flowchart of the vertical buried pipe drilling construction process of a multi-condition collaborative control and vertical buried pipe construction method for a ground source heat pump system according to the present invention. Figure 2This is a schematic diagram of the operating principle of a ground source heat pump system, which is described in the present invention as a multi-condition collaborative control and vertical buried pipe construction method for a ground source heat pump system. Figure 3 This is a system multi-condition control logic diagram of a ground source heat pump system multi-condition collaborative control and vertical buried pipe construction method according to the present invention. Detailed Implementation

[0018] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to specific embodiments and the accompanying drawings. It should be understood that these descriptions are merely exemplary and not intended to limit the scope of the invention. Furthermore, descriptions of well-known structures and techniques are omitted in the following description to avoid unnecessarily obscuring the concept of the invention.

[0019] Example: The following describes the implementation process of the present invention in detail with reference to engineering examples.

[0020] 1. Project Overview: The total construction area of ​​the project is 66,121.82 m². 2 The ground source heat pump system includes two heat pump units with a heating capacity of 157.7kW and a cooling capacity of 148.8kW, one electric chiller with a cooling capacity of 282kW, and 120 vertical buried pipes to provide cooling and heating services for commercial and auxiliary buildings.

[0021] 2. Vertical buried pipe construction implementation, such as... Figure 1 As shown: (1) Surveying and setting out: Based on the two elevation points (absolute elevation 9.200m) provided by the project, a DJ2 theodolite was used to measure and mark 120 drilling positions at 4m×4m intervals. The hole positions were numbered 001-120. When encountering underground pipelines, the hole positions were adjusted by ≤500mm. The work was carried out after approval by the design unit.

[0022] (2) Drilling construction: XY-4 type drilling rig was used. The base was calibrated with a level ruler and the levelness was 0.3mm / m. The tower was calibrated with a plumb bob and the deviation was 0.8‰. A 150mm alloy drill bit was selected. After drilling to 100m, a 3m through hole was drilled. The soil conditions (topsoil, middle layer silty clay, deep layer moderately weathered rock) were recorded every 5m. The mud pit is excavated to a size of 2m×1.5m×1m, and the mud circulation trench is 0.3m wide. The sand in the trench is cleaned in real time. When the hole is cleared, it is flushed with clean water for 12 minutes. Drilling is stopped after the mud is free of sand.

[0023] (3) Construction of underground riser: PE100 double U pipe with specification D63, upon arrival inspection, there are no cracks in appearance, 3 pipes (10%) are randomly selected for inspection; clean tap water is used for pressure test, 1.5MPa pressure is stabilized for 15min, pressure drop is 0.04MPa (≤3%), pressure is maintained at 0.5MPa; double U pipe is fixed with PP material separation positioning pipe clamps (spacing 2.8m), 5 people lift the pipe evenly, and a special pipe lowering tool is used to lower the pipe at a speed of 0.5m / min. A 1.2m pipe section is reserved on the ground and the pipe opening is fixed with wooden squares.

[0024] (4) Backfilling of buried pipes: Option 1 (original slurry backfilling) is adopted, with backfilling pump model HB-6 and flow rate 6m³ / h. 3 / h, backfill from bottom to top until the mud overflows, observe the settlement in the hole after 24 hours, and add mud until it is compacted; record the pipeline pressure every 30 minutes during backfilling, and keep it at 0.5MPa. After there are no abnormalities, use PE pipe caps to heat-seal the pipe opening.

[0025] 3. Implementation of multi-condition control of the system, such as... Figure 2 , Figure 3 As shown: (1) Winter heating (outdoor design temperature -9.5℃): The user-side water supply temperature is set at 40℃. When one heat pump is running, the water supply temperature feedback is 38℃ (difference 2℃ > △T1 = 1℃) and lasts for 10 minutes, then one heat pump is turned on. When two heat pumps are running, the load rate is 42% < 45% and lasts for 10 minutes, then one heat pump is turned off. The frequency of the underground pipe circulation pump is 42Hz, and the flow rate meets the design requirements.

[0026] (2) Summer cooling (outdoor design dry bulb 34.8℃ / wet bulb 26.6℃): The heat dissipation setting of the buried pipe is 5000kWh, and the soil temperature setting is 28℃; the initial heat dissipation is 3200kWh and the soil temperature is 26℃. The electric chiller is grounded to the buried pipe system, and two buried pipe circulation pumps are turned on (frequency 45Hz); the heat dissipation in the later stage is 5200kWh and the soil temperature is 29℃. The system is switched to the cooling water system, and the cooling tower fan is adjusted according to "outlet water temperature = 26.6℃ + 3℃ = 29.6℃" with a frequency of 38Hz.

[0027] (3) Energy storage operation (off-peak electricity 23:00-7:00): During heat storage, the heat pump supplies water at 41℃, and the water temperature at the outlet of the energy storage tank rises from 30℃ to 38℃ (difference 8℃>△T3=5℃), and stops after 1 minute; During cold storage, the electric chiller supplies water at 6℃, and the water temperature at the outlet of the energy storage tank drops from 18℃ to 10℃ (difference 8℃>△T3=5℃), and stops after 1 minute; During peak electricity, the energy storage tank is used for cooling / heating, the unit is shut down, and energy consumption is reduced by 32%.

[0028] 4. Implementation results: After the construction was completed, the heat exchange efficiency of the buried pipe was tested to be 45W / m·K, which meets the design requirements; after 3 months of system operation, the average energy consumption was reduced by 28% compared with the traditional solution, the soil temperature fluctuated by 1.5℃, the operation was stable, and no failures occurred.

[0029] Therefore, this invention adopts the above-mentioned multi-condition collaborative control and vertical buried pipe construction method for a ground source heat pump system, which improves construction quality: drilling positioning error ≤50mm, verticality deviation ≤1‰, backfill compaction ≥95%, avoiding buried pipe cross-hole and damage, and improving heat exchange efficiency by 15-20%; energy consumption is reduced: multi-condition collaborative control reduces water pump energy consumption by 25-30%, and the energy storage mode utilizes off-peak electricity, reducing operating costs by 30-35%; stability is enhanced: the switching basis for the summer cooling system is clear, soil temperature fluctuation is ≤2℃, and the long-term failure rate of the system is reduced by 40%; versatility is strong: it is applicable to ground source heat pump projects of different building scales, and the construction parameters can be adjusted according to the project, making it widely adaptable.

[0030] 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 preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can still be made to the technical solutions of the present invention, and these modifications or equivalent substitutions cannot cause the modified technical solutions to deviate from the spirit and scope of the technical solutions of the present invention.

Claims

1. A method for constructing vertical buried pipes for a ground source heat pump system, characterized in that, Includes the following steps: S1. Measurement and layout and borehole positioning: Select benchmark points based on the building and measure and lay out the lines. Design the drilling spacing based on the measurement and layout results, and mark the positions of all boreholes according to the designed spacing. S2. Drilling construction: During the drilling process, control the drilling rig chassis to be horizontal and the tower to be vertical, and record the soil conditions. After drilling to the effective depth, continue drilling to form a through hole, and simultaneously excavate the mud pit and clean up the mud. S3. Construction of underground risers: Double U-pipes are used. Pressure test is performed before the pipe is laid. The pipe is laid at a uniform speed and the double U-pipes are fixed with separation positioning pipe clamps. Pipe sections are reserved on the ground and fixed. S4. Backfilling of buried pipes: Use undiluted slurry to backfill from bottom to top until it overflows, and then fill it again after it settles. Monitor the pipe pressure in real time during the backfilling process. If the pressure is abnormal, stop backfilling and investigate. After passing the inspection, seal the pipe opening.

2. The method for constructing a vertical buried pipe for a ground source heat pump system according to claim 1, characterized in that, In step S1, the theodolite is used for the measurement and setting out, the drilling spacing is designed to be 4m×4m, and wooden stakes are set at the center points of all drilling positions. When there are underground obstacles at the marked borehole location, the design plan after adjusting the borehole location will be submitted to the design unit for approval. After the design unit approves it, the marked location of the borehole will be adjusted.

3. The method for constructing a vertical buried pipe for a ground source heat pump system according to claim 1, characterized in that, In step S2, the drilling rig is equipped with a level, and the drill bit is 150mm or 200mm in size. The drilling rig chassis is controlled to be level with a horizontality of ≤0.5mm / m. The tower is vertically calibrated using a plumb bob. The effective drilling depth is 100m, and the through-hole depth is 3m. Soil conditions are recorded every 5m during drilling. The mud pit is ≤5m from the borehole. The specific steps for cleaning the mud are: cleaning the sand particles in the circulating mud in the mud pit in real time; flushing the hole with clean water for ≥10 minutes when the hole is clear, and stopping when there are no sand particles in the mud.

4. The method for constructing a vertical buried pipe for a ground source heat pump system according to claim 1, characterized in that, In step S3, the double U-tube is a PE100 polyethylene double U-tube; a special pipe-laying tool is used when laying the pipe, and the spacing of the separation positioning pipe clamps is ≤3m; the length of the reserved pipe section on the ground is 0.5m-1.5m. The pressure test before pipe laying is as follows: before laying the pipe, test it with a pressure of 1.5MPa for 15 minutes. If the pressure drop is ≤3%, the pipe is qualified and pressure is maintained at 0.5MPa; if the pressure drop is >3%, the pipe is unqualified.

5. The method for constructing a vertical buried pipe for a ground source heat pump system according to claim 1, characterized in that, The construction method also includes horizontal pipe construction, specifically: Dig a trench and lay fine sand, then test the horizontal pipe. After the test, lay the horizontal pipe in the trench, connect the horizontal pipe to the double U-pipe using an electrofusion sleeve, and backfill the horizontal pipe. The backfilling method for horizontal pipes is as follows: both sides of the pipe are backfilled simultaneously, and the top 50cm of the pipe is lightly compacted. The horizontal pipe pressure test is as follows: pressure 1.0MPa, stabilize pressure for 15min. If the pressure drop is ≤3%, the horizontal pipe is qualified; if the pressure drop is >3%, the horizontal pipe is unqualified.

6. The method for constructing a vertical buried pipe for a ground source heat pump system according to claim 1, characterized in that, Before the construction of the vertical buried pipe, the drilling rig operators were given a special briefing, including: the drilling positioning error ≤ 50mm and the drilling verticality deviation ≤ 1‰. When the buried pipes arrive on site, their appearance and specifications shall be inspected. The appearance standards include: no bubbles or cracks. The sampling rate shall be 10% and no less than 1 pipe.

7. A multi-condition collaborative control method for a ground source heat pump system, applying the vertical buried pipe construction method for a ground source heat pump system according to any one of claims 1-6, characterized in that, Includes the following control logic: S21. Winter heating condition: The number of heat pumps is controlled based on the user-side water supply temperature feedback value and the heat pump load rate. The system detects the current number of heat pumps in operation. If one heat pump is operating, the system controls the number of heat pumps based on the water supply temperature feedback value. If two heat pumps are operating, the system controls the number of heat pumps based on the heat pump load rate. S22. Summer cooling operation: Monitor the heat dissipation of the buried pipe system into the ground and the soil temperature; Check whether the heat dissipation is less than the set heat dissipation value or the soil temperature is less than the set soil temperature value. If they are met, the electric chiller is grounded into the underground pipe system and two underground pipe circulation pumps are turned on. If they are not met, the electric chiller is switched to the cooling water system and the cooling tower fan automatically adjusts its frequency according to the cooling water outlet temperature = outdoor wet bulb temperature + 3℃. S23, Energy Storage Operation: Different control strategies are implemented according to the electricity consumption period; Check if the current time is between 23:00 and 7:

00. If yes, execute the off-peak electricity strategy; otherwise, execute the peak electricity strategy. The off-peak electricity strategy is as follows: Detect whether the current mode is thermal storage or cold storage. If it is thermal storage, close the main valve on the user side and the bypass valve of the energy storage tank, open the differential pressure bypass valve and the upper inlet and lower outlet valve of the energy storage tank, run one heat pump, and check whether the outlet water temperature of the tank meets the set value of tank outlet water temperature - supply water temperature > 5℃ and lasts for 1 minute. If yes, stop the operation of the heat pump; if not, keep one heat pump running. If it is in cold storage mode, close the main valve on the user side and the bypass valve of the energy storage tank, open the differential pressure bypass valve and the lower inlet and upper outlet valve of the energy storage tank, run one heat pump / electric chiller, and check whether the outlet water temperature of the tank meets the set value of the supply water temperature - the outlet water temperature of the tank is >5℃ and lasts for 1 minute. If yes, stop the operation of the heat pump / electric chiller; if not, keep one heat pump / electric chiller running. The peak power strategy is to shut down the generating units and use energy storage tanks for cooling / heating.

8. The multi-condition coordinated control method for a ground source heat pump system according to claim 7, characterized in that, In step S21, controlling the number of heat pumps based on the water supply temperature feedback value is specifically as follows: check whether the water supply temperature feedback value meets the water supply temperature setpoint - feedback value > 1℃ and lasts for 10 minutes. If yes, add 1 heat pump; if not, keep 1 heat pump running. The specific method for controlling the number of heat pumps based on the heat pump load rate is as follows: calculate the heat pump load rate, check whether the heat pump load rate is <45% for 10 minutes. If so, shut down one heat pump; otherwise, keep two heat pumps running.

9. The multi-condition coordinated control method for a ground source heat pump system according to claim 7, characterized in that, In step S22, the control of the number of operating devices is as follows: Detect currently running equipment; If only one heat pump is running, check whether the heat pump meets the cooling demand. If it does, keep the heat pump running; otherwise, stop the heat pump and start the electric chiller. If one electric chiller is running, check whether the one electric chiller meets the cooling demand. If it does, keep it unchanged; if not, add one heat pump. If the system is operating with 1 electric chiller and 1 heat pump, check if the equipment load rate meets the requirement of load rate < reduce set value for 10 minutes. If yes, turn off 1 heat pump; otherwise, keep it unchanged. The range of the automatic frequency adjustment is 20-50Hz.

10. The multi-condition coordinated control method for a ground source heat pump system according to claim 7, characterized in that, In the aforementioned collaborative control method, the underground pipe circulation pump and the user-side heat pump adopt frequency conversion control; The underground pipe circulation pump is linked with the heat pump in a 1:1 ratio during heating operation; when the chiller is connected to the power supply during cooling operation, two underground pipe circulation pumps are turned on, and the pump frequency adjustment range is 30-50Hz; the user-side pump adjusts its frequency according to the most unfavorable pressure difference at the end, with a range of 30-50Hz.

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