A method for testing thermal properties of rock-soil under multiple working conditions

Abstract

This application discloses a geotechnical thermal property testing method adaptable to multiple operating conditions, including: acquiring a test mode; generating target control information based on the test mode; controlling valve components to form a target fluid path according to the target fluid path, and controlling a first and / or second cooling and heating unit to participate in the cooling and heating regulation of the circulating medium in the circulation pipeline according to the target cooling and heating unit; acquiring test data; determining the actual control quantity based on the test data, and adjusting the output power of the first and / or second cooling and heating unit according to the actual control quantity and the target control quantity; addressing the issue that geotechnical thermal property testing using a fixed fluid path and a single cooling and heating source makes it difficult to coordinate the control of the constant inlet temperature requirement of the buried borehole in constant operating condition testing and the stable output power requirement of the instrument in constant flow testing, resulting in insufficient stability and low reliability of test data in the multi-condition testing process. This application achieves stable adaptation of testing under multiple test modes.

Description

Technical Field

[0001] This application relates to the field of ground source heat pumps, and in particular to a method for testing the thermal properties of soil and rock that is adaptable to multiple operating conditions. Background Technology

[0002] With the widespread application of ground source heat pump technology in building energy conservation, the design rationality and operational economy of buried pipe heat exchange systems increasingly depend on the accurate acquisition of geotechnical thermal property parameters. Geotechnical thermal response tests are an important means of obtaining parameters such as thermal conductivity, thermal diffusivity, volumetric specific heat capacity, and heat transfer capacity per unit burial depth. Among these, the stability of test data such as temperature, flow rate, and heat transfer power directly affects the reliability of subsequent calculations of geotechnical thermal property parameters.

[0003] Existing methods for testing the thermal properties of soil and rock mainly include the constant heat flow method and the constant operating condition method. The constant heat flow method, corresponding to constant heat flow and constant cold flow test conditions, focuses more on whether the heat transfer power input or extracted per unit time is stable. The constant operating condition method, corresponding to constant heat and constant cold test conditions, focuses more on whether the inlet temperature of the buried pipe is stable. Because the control objectives differ for different test conditions, the requirements for the output capacity of the heat and cold sources, the participation relationship of the heat and cold sources, and the connection method of the circulation pipeline also vary. Simply using the same fluid path and the same heat and cold source adjustment method can easily lead to a mismatch between the control objective and the actual object being adjusted.

[0004] However, existing geotechnical thermal property testing devices and methods mostly employ fixed fluid paths and single cold / heat source regulation logic. While these can achieve stable control under constant operating or constant heat flow test conditions, their limitation to a single testing mode prevents the obtained data from being cross-verified across multiple operating conditions. This results in insufficient accuracy and reliability of the calculated thermal property parameters, particularly failing to meet the needs of complex geological conditions or demanding testing scenarios. Therefore, there is an urgent need for a geotechnical thermal property testing method that can achieve unified testing under multiple operating conditions and cross-verification of results. Summary of the Invention

[0005] To address the problem that existing geotechnical thermal property testing methods employ fixed fluid paths and single cold / heat source regulation logic, making it difficult to coordinate control based on the different requirements for inlet temperature stability and heat exchange power stability in constant-condition and constant-flow tests, resulting in insufficient stability and reduced reliability of test data in multi-condition testing, this application provides a geotechnical thermal property testing method adaptable to multiple conditions. This method matches the target fluid path, participating cold / heat regulation units, and target control variables through test modes, and performs closed-loop regulation of the output power of the cold / heat regulation units based on detection data, thereby achieving stable adaptation of the testing process under various test modes.

[0006] This application provides a geotechnical thermophysical property testing method adaptable to multiple working conditions, applied to a testing device. The testing device includes a circulation pipeline for connecting to the buried pipe under test, a second heating and cooling regulation unit installed on the circulation pipeline, a first heating and cooling regulation unit selectively connected to the circulation pipeline, a valve assembly for switching fluid paths, a flow detection element, and a temperature detection element. The method includes:

[0007] Obtain the test mode, which includes the first test mode and the second test mode;

[0008] Target control information is generated based on the test mode. The target control information includes the target fluid path, the target heating and cooling regulation unit involved in the regulation, and the target control quantity.

[0009] The valve assembly is controlled to form the target fluid path according to the target fluid path, and the second and / or first cooling and heating regulating units are controlled to participate in the cooling and heating regulation of the circulating medium in the circulation pipeline according to the target cooling and heating regulating unit.

[0010] Acquire detection data, including circulating medium flow rate, soil temperature, water outlet temperature of the first and second heating and cooling units;

[0011] The actual control quantity is determined based on the detection data, and the output power of the first cooling and heating unit and / or the second cooling and heating unit is adjusted according to the actual control quantity and the target control quantity, so that the difference between the target control quantity and the actual control quantity is less than the threshold.

[0012] When the difference between the target control quantity and the actual control quantity is less than the threshold, test data is obtained for calculating the thermal physical parameters of soil and rock.

[0013] Compared to existing technologies, the advantages of this application are:

[0014] Existing methods for testing the thermophysical properties of soil and rock typically employ fixed fluid paths and single cold / heat source regulation logic. When switching between constant-condition and constant-flow tests, mismatches in the controlled objects can easily occur. For example, constant-condition tests require a stable inlet temperature of the buried pipe, while constant-flow tests require a stable heat exchange power per unit time. If the same pipeline and power regulation method are used, inlet temperature fluctuations or deviations in heat exchange power from the set value may occur, thus affecting the reliability of the test data. To address this, this application synchronously generates the target fluid path, the target cold / heat regulation units involved in the regulation, and the target control quantity according to the test mode. Based on the circulating medium flow rate, soil temperature, and the outlet water temperatures of the first and second cold / heat regulation units, the actual control quantity is determined. Then, the output power of the cold / heat regulation units is adjusted according to the difference between the actual control quantity and the target control quantity. This enables constant-condition testing to achieve closed-loop stable control around the target temperature at the inlet of the buried pipe, and constant-current testing to achieve closed-loop stable control around the target heat transfer power. This avoids control mismatch caused by sharing fixed control logic among different test modes, thereby improving the stability of temperature or heat transfer power during multi-condition geotechnical thermal property testing and enhancing the reliability of test data used to calculate geotechnical thermal property parameters. Attached Figure Description

[0015] This application will be further described by way of exemplary embodiments, which will be described in detail with reference to the accompanying drawings. These embodiments are not limiting; in these embodiments, the same reference numerals denote the same structures, wherein:

[0016] Figure 1 This is a flowchart of the thermophysical property testing process for this application;

[0017] Figure 2 This is a technical roadmap for a geotechnical thermophysical property testing method adapted to multiple working conditions, as described in this application.

[0018] Figure 3 This is a grouping diagram of the thermal properties of the fluid path in this application;

[0019] Figure 4 This is a schematic diagram of the pipeline fluid path corresponding to the constant heat flow in this application;

[0020] Figure 5 This is a schematic diagram of the pipeline fluid path corresponding to the four working conditions in this application;

[0021] Figure 6 This is a schematic diagram of the constant heat condition test mode logic of this application;

[0022] Figure 7 This is the calculation roadmap for the constant heat condition test mode of this application;

[0023] Figure 8 This is a schematic diagram of the constant cooling condition test mode logic of this application;

[0024] Figure 9 This is the calculation roadmap for the constant cooling condition test mode of this application;

[0025] Figure 10 This is a logic diagram of the constant heat flow test mode of this application;

[0026] Figure 11 This is a logic diagram of the constant heat flow test mode 2 of this application;

[0027] Figure 12 This is the calculation roadmap for the constant heat flux test mode of this application;

[0028] Figure 13 This is a schematic diagram of the constant cold flow test mode logic of this application;

[0029] Figure 14 This is the calculation roadmap for the constant cold flow test mode of this application.

[0030] Explanation of the labels in the diagram:

[0031] 10. Tester housing; 11. Filter; 12. Flow meter; 13. Heating tank; 14. Heating rod; 15. Water pump; 16. Control valve one; 17. Temperature sensor one; 18. Temperature sensor two; 19. Temperature sensor three;

[0032] 20. Buried side section; 21. Buried pipe inlet pipe; 22. Buried pipe outlet pipe;

[0033] 30. External cold and heat source section; 31. Air source heat pump; 32. Water supply tank; 33. Control valve two; 34. Control valve three; 35. Control valve four. Detailed Implementation

[0034] To make the objectives, technical solutions, and advantages of this application clearer, the embodiments of this application will be described in further detail below with reference to the accompanying drawings. It should be understood that the following embodiments are for illustrative purposes only and are not intended to limit the scope of protection of this application.

[0035] This application provides a method for testing the thermophysical properties of soil and rock that is adaptable to multiple working conditions, and this method can be applied to testing devices. For example... Figure 1As shown, the testing device may include a circulation pipeline for communication with the buried pipe under test, a second heating and cooling regulation unit disposed on the circulation pipeline, a first heating and cooling regulation unit selectively connected to the circulation pipeline, a valve assembly for switching fluid paths, a flow detection device, and a temperature detection device. Optionally, the second heating and cooling regulation unit is a heating tank 13, and the first heating and cooling regulation unit is an air source heat pump 31. The heating tank 13 is used to provide heating power to the circulation medium, the air source heat pump 31 is used to provide heating power or cooling power to the circulation medium, the flow detection device can be a flow meter 12, and the temperature detection device may include multiple temperature sensors.

[0036] The testing device may include a testing instrument housing 10, a buried side section 20, and an external heat source / cold source section 30. The testing instrument housing 10 may include a filter 11, a flow meter 12, a heating tank 13, a heating rod 14, a water pump 15, a control valve 16, a temperature sensor 17, a temperature sensor 18, and a temperature sensor 19. The filter 11 is used to filter impurities in the circulating medium; the flow meter 12 is used to detect the flow rate m of the circulating medium; the heating rod 14 is disposed inside the heating tank 13 and is used to provide heating power to the circulating medium within the heating tank 13; the water pump 15 is used to drive the circulating medium to circulate; and the temperature sensor 17 is used to detect the soil temperature or the temperature at a corresponding location in the buried side circuit. Temperature sensor 2, 18, is used to detect the outlet water temperature of heating tank 13. Temperature sensor 319 is used to detect the outlet water temperature of air source heat pump 31. .

[0037] The underground side portion 20 may include an underground pipe inlet pipe 21 and an underground pipe outlet pipe 22, which are used to connect the underground pipe to be tested.

[0038] The external heat source / cold source section 30 may include an air source heat pump 31, a water supply tank 32, a second control valve 33, a third control valve 34, and a fourth control valve 35. The air source heat pump 31 is optionally connected to the circulation pipeline and is used to provide heating or cooling power to the circulation medium according to the test mode; the water supply tank 32 is used to replenish the circulation medium to the circulation pipeline; the first control valve 31, the second control valve 33, the third control valve 34, and the fourth control valve 35 together constitute a valve assembly, which allows the test device to form different fluid paths through different opening and closing combinations. Optionally, Figure 1 The pink pipes in the diagram represent PE pipe connections, the black pipes represent steel pipe connections, and the orange pipes represent steel flexible hose connections; the above pipe types are merely examples and are not intended to limit the scope of this application.

[0039] Existing methods for testing the thermal properties of soil and rock typically employ fixed fluid paths and single heat / cold source regulation logic, making it difficult to synchronously match fluid paths, heat / cold source participation relationships, and target control quantities based on the differences between constant-condition and constant-flow tests. Therefore, this application's embodiment generates target control information based on the test mode, matching the target fluid path, the target heat / cold regulation units involved in the regulation, and the target control quantity with the test mode. Based on the detection data, the actual control quantity is determined, and then the output power of the heating tank 13 and / or the air source heat pump 31 is adjusted according to the difference between the actual and target control quantities. This allows for stable control of the constant-condition test around the inlet temperature of the buried pipe, and stable control of the constant-flow test around the heat exchange power.

[0040] The following is combined Figures 2 to 14 This application describes a geotechnical thermophysical property testing method adapted to multiple working conditions, as provided in the embodiments of this application. This method can be executed by the control unit of the testing device, which can be communicatively connected to the valve assembly, flow meter 12, various temperature sensors, heating tank 13, and air source heat pump 31.

[0041] Step 1, obtain the test mode.

[0042] Optionally, the test mode can be selected by the user through a human-computer interaction interface, or it can be automatically determined by the control unit based on pre-configured test tasks. For example... Figure 2 As shown, the test modes can include constant heat condition test mode, constant cold condition test mode, constant heat flow test mode, and constant cold flow test mode. Among them, the constant heat condition test mode and the constant cold condition test mode belong to the constant condition test modes with the control objective of stabilizing the inlet temperature of the buried pipe; the constant heat flow test mode and the constant cold flow test mode belong to the constant flow test modes with the control objective of stabilizing the heat exchange power.

[0043] The target control quantity may include the target temperature at the inlet of the buried pipe or the target heat exchange power. The target temperature at the inlet of the buried pipe refers to the expected temperature of the circulating medium entering the buried pipe under test in a constant-condition test mode; the target heat exchange power refers to the expected input heat / cold energy per unit time to be maintained in a constant-flow test mode.

[0044] Specifically, when the test mode is constant operating condition test mode, the subsequent control logic revolves around the target temperature of the buried pipe inlet to avoid the inlet temperature fluctuation affecting the constant operating condition test data; when the test mode is constant flow test mode, the subsequent control logic revolves around the target heat exchange power to avoid the actual heat exchange power deviating from the set value.

[0045] Step 2: Generate target control information based on the test mode.

[0046] The target control information includes the target fluid path, the target heating and cooling regulation units involved in the regulation, and the target control quantity. The target fluid path characterizes the flow path of the circulating medium within the test device, the target heating and cooling regulation units involved in the regulation characterize the heat and cold sources that need to participate in the heating and cooling regulation under the current test mode, and the target control quantity characterizes the object that needs to be stabilized for closed-loop control under the current test mode.

[0047] like Figures 3 to 5 As shown, where, Figure 3 This is a grouping diagram of fluid paths with thermal properties. Figure 4 For constant heat flow, the corresponding pipeline fluid path is one. Figure 5 The second pipeline fluid path corresponds to the four operating conditions: constant heat flow, constant cold flow, constant heat condition, and constant cold condition.

[0048] The testing device may include a first fluid path and a second fluid path. The first fluid path is a fluid path formed by connecting a circulation pipe, a first heating and cooling regulation unit, and the buried pipe under test. When the second heating and cooling regulation unit is a heating tank, the first fluid path can be understood as a circulation path formed by the heating tank, circulation pump, flow meter, and the buried pipe under test, where the air source heat pump does not participate in the heat exchange of the circulating medium. The second fluid path is a fluid path formed by connecting a circulation pipe, a first heating and cooling regulation unit, a second heating and cooling regulation unit, and the buried pipe under test. When the second heating and cooling regulation unit is a heating tank and the first heating and cooling regulation unit is an air source heat pump, the second fluid path can be understood as a path where both the heating tank and the air source heat pump participate in the regulation of the circulating medium. The air source heat pump, as a primary heating and cooling regulation unit, is used for primary heating or primary cooling of the circulating medium; the heating tank, as a secondary heating unit, is used for secondary heating or supplementary heating regulation of the circulating medium after regulation by the air source heat pump.

[0049] Optionally, when the test mode is constant heat flow test mode, the control unit can select the first fluid path as the target fluid path, select the second heating and cooling adjustment unit as the target heating and cooling adjustment unit to participate in the adjustment, and use the target heat exchange power as the target control quantity.

[0050] Specifically, the constant heat flow test mode supports two test paths: Path One and Path Two, allowing operators to flexibly choose according to actual testing needs. During the constant heat flow test, the system's terminal heat source is fixed to the heating tank. This is because air source heat pumps use a temperature feedback control mechanism, and due to the influence of temperature control logic, their output response has an inherent lag, making it difficult to meet the stringent requirements of constant heat flow testing for heat source output stability. In contrast, the heating tank has a stepless adjustment function, which can continuously and accurately adjust the output power according to testing needs, providing a stable heat flow output for the experiment and ensuring the stability and reliability of the test data.

[0051] Optionally, when the test mode is constant cold flow test mode, the control unit selects the second fluid path as the target fluid path, uses the first and second cold and heat regulation units as the target cold and heat regulation units participating in the regulation, and uses the target heat exchange power as the target control variable. Since the constant cold flow test requires providing cooling to the circulating medium, the air source heat pump can act as a primary cold source to output cooling power; simultaneously, the heating tank can act as a secondary heating unit to supplement and regulate the circulating medium after it has been cooled by the air source heat pump. Through the coupling of the primary cooling of the air source heat pump and the secondary heating of the heating tank, the net cooling power can be finely adjusted, stabilizing the actual heat exchange power near the target heat exchange power. Here, the output power of the air source heat pump refers to both cooling and heating capacity.

[0052] Optionally, when the test mode is a constant heat condition test mode or a constant cold condition test mode, the control unit selects the second fluid path as the target fluid path, uses the first and second cooling and heating adjustment units as the target cooling and heating adjustment units participating in the adjustment, and uses the target temperature of the buried pipe inlet as the target control variable. Specifically, in the constant heat condition test mode, the air source heat pump can provide primary heating for the circulating medium, and the heating tank can provide secondary heating or supplementary heating for the circulating medium after it has been heated by the air source heat pump, so as to stabilize the buried pipe inlet temperature near the target temperature of the buried pipe inlet. In the constant cold condition test mode, the air source heat pump can provide primary cooling for the circulating medium, and the heating tank can provide secondary supplementary heating for the circulating medium after it has been cooled by the air source heat pump, so as to avoid the buried pipe inlet temperature being too low or the temperature fluctuation being too large, thereby stabilizing the buried pipe inlet temperature near the target temperature of the buried pipe inlet.

[0053] Specifically, in the embodiments of this application, the target control information associates the test mode, the target fluid path, the target heating and cooling adjustment unit involved in the adjustment, and the target control quantity. Compared with the method of using a fixed fluid path and a single heating and cooling source adjustment logic, this application can avoid the problem of only switching the heating and cooling source or only switching the set power without simultaneously switching the controlled object.

[0054] For example, in constant-condition testing, linking the second fluid path, the combined participation of the heating tank and the air-source heat pump, and the target temperature at the inlet of the buried pipe helps stabilize the inlet temperature. In constant-flow testing, linking the corresponding fluid path, the participation of the cold and heat sources, and the target heat exchange power helps stabilize the heat exchange per unit time. This improves control consistency and testing stability when switching between different testing modes.

[0055] Step 3: Control the valve assembly to form the target fluid path according to the target fluid path, and control the second and / or first cooling and heating adjustment units to participate in the cooling and heating adjustment of the circulating medium in the circulation pipeline according to the target cooling and heating adjustment unit.

[0056] Optionally, the control unit controls the opening and closing states of each valve in the valve assembly according to the target fluid path, causing the circulating medium to flow along either the first or second fluid path. The valve assembly may include multiple control valves disposed between the heating tank, the air source heat pump, and the underground pipe under test. Different combinations of opening and closing of the control valves determine whether the air source heat pump is connected to the circulating pipeline. That is, in the first fluid path, the circulating medium flows through the heating tank and the underground pipe under test, and the air source heat pump can be bypassed or not participate in heat exchange; in the second fluid path, the circulating medium flows sequentially through the air source heat pump, the heating tank, and the underground pipe under test, so that both the air source heat pump and the heating tank participate in the temperature regulation of the circulating medium.

[0057] like Figure 2 As shown, after determining the test mode, the control unit can perform graded adjustments to the circulating medium according to the test mode. The first-level adjustment controls the first heating / cooling unit to heat or cool, while the second-level adjustment controls the second heating / cooling unit to heat. Optionally, when the second heating / cooling unit is a heating tank and the first heating / cooling unit is an air-source heat pump, the first-level adjustment can be for heat pump heating or cooling, and the second-level adjustment can be for heating the heating tank. Thus, the air-source heat pump undertakes the main heating / cooling load adjustment of the circulating medium, while the heating tank undertakes secondary supplementary heating or fine-tuning, thereby improving the stability of temperature or heat exchange power control under different test modes.

[0058] Specifically, in the constant heat flow test mode, the control unit can control the valve assembly to form a first fluid path and control the first cooling and heating adjustment unit to output heating power; when the target heat exchange power corresponding to the constant heat flow test mode is greater than the preset output capacity of the first cooling and heating adjustment unit, or when the test requires the use of a second fluid path, the control unit can also control the valve assembly to form a second fluid path and control the first cooling and heating adjustment unit and the second cooling and heating adjustment unit to jointly output heating power.

[0059] In the constant cooling flow test mode, the control unit controls the valve assembly to form a second fluid path, controls the first cooling and heating regulation unit to output cooling power, and controls the second cooling and heating regulation unit to output heating power. In other words, the air source heat pump outputs primary cooling power, and the heating tank outputs secondary heating power, thereby achieving cold and heat coupling regulation of the circulating medium. In this way, the air source heat pump can provide basic cooling capacity, and the heating tank can supplement and correct the circulating medium's heat transfer, ensuring that the actual heat exchange power is stabilized near the target heat exchange power.

[0060] In the constant heat condition test mode, the control unit controls the valve assembly to form a second fluid path, controls the output heating power of the first heating and cooling regulation unit, and controls the output heating power of the second heating and cooling regulation unit. In other words, the air source heat pump outputs primary heating power, and the heating tank outputs secondary heating power, thereby jointly heating and regulating the circulating medium to stabilize the inlet temperature of the buried pipe near the target inlet temperature.

[0061] In the constant cooling condition test mode, the control unit controls the valve assembly to form a second fluid path, controls the first cooling and heating regulation unit to output cooling power, and controls the second cooling and heating regulation unit to output heating power. In other words, the air source heat pump outputs primary cooling power, and the heating tank outputs secondary heating power, thereby performing cold and heat coupling regulation of the circulating medium to stabilize the inlet temperature of the buried pipe near the target inlet temperature.

[0062] Specifically, for constant heat flow tests aimed at stabilizing the target heat exchange power, this application allows the air source heat pump to not participate in the circulation when the heating tank can meet the power requirements, which helps reduce unnecessary primary heating and control lag. When the heating tank's heating capacity is insufficient, the air source heat pump can be connected for supplementary heating. For constant cold flow tests, since cold output is required, the air source heat pump is connected to the second fluid path to provide cooling power. At the same time, the net cooling power is adjusted by the heating tank's heating power, which helps stabilize the heat exchange power near the set value. For constant heat and constant cold conditions, primary heating or cooling is performed by the air source heat pump, and secondary heating is performed by the heating tank for fine adjustment. This avoids response lag or over-adjustment when a single heat or cold source directly adjusts the inlet temperature of the buried pipe, thereby improving the inlet temperature stability.

[0063] Step 4: Obtain the detection data.

[0064] The detection data includes circulating medium flow rate, soil temperature, outlet water temperature of the first and second heating and cooling units.

[0065] like Figure 2 As shown, the control unit acquires detection data during the test, which may include soil temperature. Circulating medium flow rate (m), outlet water temperature of the second heating and cooling unit and the outlet water temperature of the first heating and cooling unit Among them, soil temperature Temperature data can be collected by temperature sensors located on the side of the buried pipe to be tested or at the corresponding location on the buried pipe; the circulating medium flow rate m can be collected by flow rate sensors; the outlet water temperature of the second heating and cooling unit... The temperature can be collected by a temperature sensor located on the outlet side of the second heating and cooling unit; the outlet water temperature of the first heating and cooling unit. The temperature can be collected by a temperature sensor located on the outlet side of the first heating and cooling unit.

[0066] Optionally, the second heating and cooling unit is a heating tank, and the first heating and cooling unit is an air source heat pump. In this case, the outlet water temperature of the second heating and cooling unit... The outlet water temperature of the heating tank, and the outlet water temperature of the first hot and cold water regulating unit. This refers to the outlet water temperature of the air source heat pump. The circulating medium flow rate *m* can be set according to the depth, pipe diameter, and testing requirements of the buried borehole to be tested. For example, the standard single-hole flow rate for a buried borehole can be set to 1.4 m³ / h, or it can be adjusted within the range of 1.0 m³ / h to 1.8 m³ / h depending on project needs. Soil temperature. It can be determined based on the actual measured ground temperature on site; for example, it can be set to 15℃ in conventional calculations.

[0067] Step 5: Determine the actual control quantity based on the detection data, and adjust the output power of the first cooling and heating adjustment unit and / or the second cooling and heating adjustment unit according to the actual control quantity and the target control quantity, so that the difference between the target control quantity and the actual control quantity is less than the threshold.

[0068] The actual control quantity refers to the actual measured or calculated value corresponding to the current target control quantity. The threshold is used to determine whether the actual control quantity meets the stability requirements corresponding to the target control quantity. Optionally, when the target control quantity is the target temperature of the buried pipe inlet, the threshold can be a temperature threshold, such as 0.2℃; when the target control quantity is the target heat exchange power, the threshold can be a power threshold, such as 0.06kW.

[0069] Under constant operating condition test mode, the actual control quantity can be the outlet water temperature of the second heating and cooling unit. The control unit, according to The temperature difference between the temperature at the inlet of the buried pipe and the target temperature is used to adjust the heating power of the second heating and cooling unit, so that... The temperature stabilizes near the target temperature at the inlet of the buried pipe. In constant current test mode, the actual control quantity can be the actual heat exchange power calculated based on the detection data. The control unit can calculate the heating power of the first heating / cooling unit, the cooling power of the first heating / cooling unit, and the heating power of the second heating / cooling unit according to the following formulas:

[0070]

[0071] ;

[0072] ;

[0073] Where m is the circulating medium flow rate, For the specific heat capacity of the circulating medium, For soil temperature, The outlet water temperature of the second heating and cooling unit. This refers to the outlet water temperature of the first heating and cooling unit. If the unit of m is m³ / h, The unit is kJ / (kg·℃), so when calculating power, you can multiply by 1000 / 3600 to convert the unit.

[0074] Specifically, in this application, the control unit does not calculate an overall heat exchange based solely on the total temperature difference between the inlet and outlet of the circulating medium, but rather on the soil temperature. The outlet water temperature of the first heating and cooling unit Second heating and cooling unit outlet water temperature The heating and cooling regulation process is decomposed into the heating power of the first heating and cooling regulation unit. Cooling power of the first cooling and heating control unit and the heating power of the second heating and cooling control unit Three power components can be used for control. In this way, when the air source heat pump and the heating tank participate in regulation together, the control unit can distinguish the heating or cooling contribution of the air source heat pump to the circulating medium, and the secondary heating contribution of the heating tank to the circulating medium.

[0075] Therefore, in the constant heat flow test mode, the control unit can... or Determine the actual heat exchange power; in constant cooling flow test mode, the control unit can, based on... Determine the actual heat exchange power. Avoid conflating the heat pump's cooling capacity, heating capacity, and heating tank capacity with the same heat index when both the heat source and cold source are involved, thereby reducing inaccurate heat exchange power judgment. Furthermore, the control unit can determine whether to increase or decrease the output power of the first and / or second heat exchange regulation units based on the difference between the actual and target heat exchange power, ensuring that the heat exchange power per unit time in constant current test mode remains stable near the target heat exchange power.

[0076] The control process under the four test modes is described below.

[0077] (1) Constant heat condition test mode:

[0078] Optionally, such as Figure 6 and Figure 7 As shown, in the constant heat test mode, the target control variable is the target temperature of the buried pipe inlet, which can be determined by the outlet water temperature of the heating tank. Characterization. The control unit can set the target temperature of the water outlet from the heating tank. and will This serves as the target inlet temperature for the buried pipe under constant heat conditions. For example, based on the nominal cooling condition inlet water temperature of 25℃ on the heat source side of the ground source heat pump, and considering a 5℃ heat exchange temperature difference, the target temperature can be... Set to 30℃.

[0079] In this constant-heat test mode, the control unit controls the air source heat pump to perform primary heating regulation, ensuring that the outlet water temperature of the air source heat pump reaches or approaches the target outlet water temperature. Since the first heating and cooling regulation unit is an air source heat pump, its outlet water temperature is the same as the air source heat pump's outlet water temperature. For example, the outlet water temperature of the air source heat pump can be made to reach or approach 26.5℃. Simultaneously, the control unit performs secondary heating regulation, ensuring that the outlet water temperature of the second heating and cooling regulation unit reaches or approaches the target temperature of the buried pipe inlet. Since the second heating and cooling regulation unit is a heating tank, the outlet water temperature of the heating tank can be controlled to reach or approach 30℃.

[0080] When the outlet water temperature of the second heating and cooling unit is higher than the target temperature at the inlet of the buried pipe, the control unit reduces the heating power of the second heating and cooling unit, i.e., reduces the heating power of the heating tank; when the outlet water temperature of the second heating and cooling unit is lower than the target temperature at the inlet of the buried pipe, the control unit increases the heating power of the second heating and cooling unit, i.e., increases the heating power of the heating tank, thereby ensuring that the outlet water temperature of the second heating and cooling unit fluctuates within the allowable deviation range of the target temperature at the inlet of the buried pipe. Optionally, the outlet water temperature of the heating tank can be stabilized at 30℃±0.2℃.

[0081] For example, under a set of conventional constant-temperature operating parameters, the circulating medium flow rate m is 1.4 m³ / h, and the specific heat capacity of the circulating medium is... The soil temperature is 4.187 kJ / (kg·℃). The outlet water temperature of the air source heat pump is 15℃. The outlet water temperature of the heating tank is 26.5℃. If the temperature is 30℃, then the heating capacity required by the air source heat pump is approximately: 1.4. 4.187 (26.5 15) 1000 / 3600=18.73kW.

[0082] The heating capacity required by the heating tank is approximately: 1.4 4.187 (30 26.5) 1000 / 3600=5.70kW.

[0083] Therefore, the total heating demand under constant heat conditions is approximately 24.43kW.

[0084] In this embodiment, the constant heat condition test mode does not directly use a single heat source to heat the circulating medium to [temperature value missing]. Instead, the air-source heat pump first heats the circulating medium to an intermediate temperature close to the target temperature, and then the heating tank finely adjusts the intermediate temperature to the target temperature at the inlet of the buried pipe. Because the target inlet temperature is high under constant thermal conditions, for example... If the entire temperature rise is achieved solely by the heating tank, both the power requirement of the heating tank and the volume of the enclosure will increase. If the temperature is directly stabilized at 30°C solely by the air source heat pump, it is susceptible to fluctuations in the inlet temperature due to the heat pump's response accuracy. This embodiment allocates approximately 18.73kW of the main heating capacity to the air source heat pump and approximately 5.70kW of fine-tuning heat to the heating tank, allowing the heating tank to handle only small temperature difference adjustments. This satisfies the total heating demand of approximately 24.43kW while simultaneously increasing the inlet temperature of the buried pipe. The ability to remain stable within the range of 30℃±0.2℃.

[0085] (2) Constant cooling condition test mode:

[0086] Optionally, such as Figure 8 and Figure 9 As shown, in the constant cooling condition test mode, the target control variable is the target temperature of the buried pipe inlet, which can be determined by the outlet water temperature of the heating tank. Characterization. The control unit can set the target temperature of the water outlet from the heating tank. and will This serves as the target inlet temperature for the buried pipe under constant cooling operating conditions. For example, based on the nominal heating condition of the ground source heat pump with an inlet water temperature of 10℃, and considering a heat exchange temperature difference of 5℃, the target temperature for the buried pipe inlet can be... Set to 5℃.

[0087] In this constant cooling test mode, the control unit controls the air source heat pump to perform primary cooling regulation, thereby maintaining the air source heat pump outlet water temperature. The water temperature reaches or approaches the target outlet temperature of the heat pump, such as 3.5℃; the control unit controls the heating tank to perform secondary heating regulation, so that the outlet water temperature of the heating tank reaches or approaches the target outlet temperature of the heat pump. Reaching or approaching .when When the control unit reduces the heating power of the heating tank; when At that time, the control unit increases the heating power of the heating tank, thereby... exist Fluctuations within a certain range.

[0088] For example, under a set of conventional constant cooling operating parameters, the circulating medium flow rate m is 1.4 m³ / h, and the specific heat capacity of the circulating medium is... The soil temperature is 4.187 kJ / (kg·℃). The outlet water temperature of the air source heat pump is 15℃. The outlet water temperature of the heating tank is 3.5℃. If the temperature is 5℃, then the required cooling capacity of the air source heat pump is approximately 1.4. 4.187 (15 3.5) 1000 / 3600 = 18.73 kW; the heating capacity required by the heating tank is approximately 1.4 kW. 4.187 (5 3.5) 1000 / 3600=2.44kW.

[0089] In this embodiment, the constant cooling condition test mode does not rely solely on the air source heat pump to directly stabilize the circulating medium at a constant temperature. Instead, the air-source heat pump first cools the circulating medium to an intermediate temperature below the target temperature. Then the heating tank will heat up the water. Fine-tuned to the target temperature at the inlet of the buried pipe Because the target inlet temperature is low under constant cooling conditions, for example... If the temperature is directly stabilized at 5°C solely by the air source heat pump, it is susceptible to fluctuations in the inlet temperature due to lag in the heat pump's cooling response or overcooling. Without a secondary heating adjustment in the heating tank, it is difficult to provide subtle compensation for the overcooled circulating medium. This embodiment allocates approximately 18.73kW of the main cooling capacity to the air source heat pump and approximately 2.44kW of fine-tuning heat to the heating tank. This allows the air source heat pump to handle the large cooling output, while the heating tank handles the small temperature difference correction, thereby increasing the outlet water temperature of the heating tank. The ability to remain stable within the range of 5℃±0.2℃.

[0090] (3) Constant heat flow test mode:

[0091] Optionally, such as Figures 10 to 12 As shown, in the constant heat flow test mode, the target control variable is the target heat transfer power. The control unit can be set according to the test conditions. For example, under normal operating conditions, the heat exchange rate per meter of a buried borehole is 60W / m, and the designed depth of the buried borehole is 200m, so the heat exchange rate of a single borehole is about 12kW; under extreme operating conditions, the heat exchange rate per meter of a buried borehole is 75W / m, and the designed depth of the buried borehole is 200m, so the heat exchange rate of a single borehole is about 15kW.

[0092] In one constant heat flow test mode, the heating tank operates independently. At this time, the control unit controls the valve assembly to form the first fluid path, preventing the air source heat pump from participating in the circulating medium heat exchange, and controls the heating tank to operate according to the target heat exchange power. Output heating power. Heating capacity of the heating tank. It can be used as the actual heat exchange power.

[0093] For example, when When the control unit reduces the heating power of the heating tank; when At that time, the control unit increases the heating power of the heating tank, thereby... Maintain at Within the specified range. Optionally, to cover extreme operating conditions, the maximum output power of the heating tank can be no less than 15kW.

[0094] In another constant heat flow test method, the air source heat pump and the heating tank operate in conjunction. In this case, the control unit controls the valve assembly to form a second fluid path, ensuring that both the air source heat pump and the heating tank participate in the heat exchange of the circulating medium. Specifically, the control unit will... As the actual heat exchange power, and compared With target heat exchange power .when When the control unit reduces the heating power of the heating tank; when At this time, the control unit increases the heating power of the heating tank, thereby maintaining the actual heat exchange power at [value missing]. Within the range.

[0095] For example, when 12kW, soil temperature The outlet water temperature of the air source heat pump is 15℃. The temperature is 20℃, the flow rate of the circulating medium is 1.4 m³ / h, and the specific heat capacity of the circulating medium is... When the efficiency is 4.187 kJ / (kg·℃), the heating capacity of the air source heat pump is approximately 1.4. 4.187 (20 15) 1000 / 3600 = 8.14kW. At this point, the heating tank needs to replenish approximately 12 kWh of heat. 8.14 = 3.86 kW.

[0096] In this embodiment, the constant heat flow test mode does not use a single heat source or a fixed fluid path, but rather is based on the target heat transfer power. The size can be selected for either standalone operation of the heating tank or combined operation of the air source heat pump and the heating tank. For typical constant heat flow conditions, such as... At this time, the heating tank can independently meet the heating demand. By adopting the first fluid path and ensuring that the air source heat pump does not participate in heat exchange, the adjustment lag and heat coupling error caused by the connection of the air source heat pump can be avoided, thus maximizing the heating power of the heating tank. It is directly used as the actual heat exchange power for closed-loop control;

[0097] For higher power or extreme operating conditions, such as when the heat exchange capacity of a single outlet approaches 15kW, a second fluid path can be used. This allows the air source heat pump to first provide approximately 8.14kW of basic heating capacity, with the heating tank supplementing the remaining approximately 3.86kW. This approach maintains simple and stable power control under normal operating conditions while allowing for distributed output from two heat sources under high power demands, avoiding the increase in equipment size and cost caused by solely increasing the heating tank capacity.

[0098] (4) Constant cold flow test mode:

[0099] Optionally, such as Figure 13 and Figure 14 As shown, in the constant cooling flow test mode, the target control variable is the target heat transfer power. For example, under normal operating conditions, the heat exchange rate per meter of a buried borehole is 30 W / m, and the designed borehole depth is 200 m, so the heat exchange rate per borehole is approximately 6.0 kW; under extreme operating conditions, the heat exchange rate per meter of a buried borehole is 50 W / m, and the designed borehole depth is 200 m, so the heat exchange rate per borehole is approximately 10 kW. The control unit can... It is set to 8.0kW, but can also be set to other target values ​​according to the actual test conditions.

[0100] In the constant cooling flow test mode, the control unit controls the valve assembly to form a second fluid path, enabling both the air source heat pump and the heating tank to participate in the circulation medium regulation. As the actual heat exchange power, and compared With target heat exchange power .when When this occurs, it indicates insufficient net cooling power, and the control unit reduces the heating power of the heating tank; when If the net cooling power is too high, the control unit increases the heating power of the heating tank to maintain the actual heat exchange power at a certain level. Within the range.

[0101] For example, when 8.0kW, soil temperature The outlet water temperature of the air source heat pump is 15℃. The temperature is 8℃, the flow rate of the circulating medium is 1.4 m³ / h, and the specific heat capacity of the circulating medium is... When the energy density is 4.187 kJ / (kg·℃), the cooling capacity output of the air source heat pump is approximately: 1.4 × 4.187 × (15 8) × 1000 / 3600 = 11.4 kW. At this point, the heating capacity that the heating tank needs to compensate for is approximately 11.4 kW. 8.0 = 3.4kW.

[0102] In this embodiment, the constant cooling flow test mode does not use only the cooling capacity of the air source heat pump as the actual heat exchange power, but rather uses the cooling capacity output by the air source heat pump. Heat output from the heating tank The difference Closed-loop control is performed based on the actual heat exchange power. Since constant cooling flow testing requires stable net heat output, adjusting the cooling capacity solely through the air source heat pump can easily lead to fluctuations in the heat pump's cooling output or large adjustment steps. Deviation from the set value.

[0103] This embodiment achieves a stable net cooling power within the range of 8.0kW ± 0.06kW by having the air source heat pump provide a base cooling capacity greater than the target heat exchange power, for example, approximately 11.4kW, and then having the heating tank provide a reverse heating compensation of approximately 3.4kW. This allows the large cooling output of the heat pump to be combined with the small power adjustment of the heating tank, improving the stability of the target heat exchange power during constant cold flow testing.

[0104] Step 6: When the difference between the target control quantity and the actual control quantity is less than the threshold, test data for calculating the geotechnical thermal property parameters is obtained.

[0105] Optionally, when the difference between the target control quantity and the actual control quantity is less than a threshold, it can be considered that the circulating medium temperature or heat exchange power in the current test mode has met the stability requirements. Furthermore, to avoid misjudgment caused by instantaneous fluctuations, the control unit can determine whether the difference between the target control quantity and the actual control quantity is less than a threshold within a preset duration. If so, test data for calculating the geotechnical thermal property parameters is obtained.

[0106] Optionally, in the constant heat condition test mode, when the outlet water temperature of the heating tank is... When the temperature is maintained within the range of 30℃±0.2℃, output test data; in the constant cooling condition test mode, when the water temperature at the outlet of the heating tank... Test data is output when the temperature is maintained within the range of 5℃±0.2℃; in constant heat flow test mode, test data is output when the actual heat exchange power is maintained within the range of the target heat exchange power ±0.06kW; in constant cold flow test mode, test data is output when the actual heat exchange power is maintained within the range of the target heat exchange power ±0.06kW.

[0107] Optionally, the test data includes at least one of the following: test mode identifier, target fluid path, circulating medium flow rate, soil temperature, outlet water temperature of the first heating and cooling unit, outlet water temperature of the second heating and cooling unit, output power of the target heating and cooling unit involved in the regulation, and test time. The output power of the target heating and cooling unit involved in the regulation includes at least one of the heating power of the first heating and cooling unit, the heating power of the second heating and cooling unit, and the cooling power of the second heating and cooling unit.

[0108] Optionally, the test data is used to select a geotechnical thermal property parameter calculation model corresponding to the test mode to calculate at least one of the geotechnical thermal conductivity, thermal diffusivity, and volumetric specific heat capacity. For example, in the constant heat flow test mode, a geotechnical thermal property parameter calculation model corresponding to the constant heat flow method can be selected; in the constant cold flow test mode, a geotechnical thermal property parameter calculation model corresponding to the constant cold flow method can be selected; in the constant heat condition test mode or the constant cold condition test mode, a geotechnical thermal property parameter calculation model corresponding to the constant condition method can be selected.

[0109] Through the above method, the embodiments of this application can synchronously match the target fluid path, the target heating and cooling adjustment unit involved in the adjustment, and the target control quantity according to the test mode; and perform closed-loop adjustment after determining the actual control quantity based on the detection data. This avoids control mismatch caused by different test modes sharing a fixed fluid path and a single heating and cooling source adjustment logic, improving the stability of the multi-condition geotechnical thermophysical property testing process and the reliability of the test data.

[0110] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application 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. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the protection scope of the technical solutions of the embodiments of this application.

Claims

1. A method for testing the thermal properties of soil and rock under multiple working conditions, applied to a testing device, the testing device comprising a circulation pipeline for connecting to the buried pipe under test, a second heating and cooling adjustment unit disposed on the circulation pipeline, a first heating and cooling adjustment unit selectively connected to the circulation pipeline, a valve assembly for switching fluid paths, a flow detection element, and a temperature detection element, characterized in that, The methods include: Obtain the test mode, which includes the first test mode and the second test mode; Target control information is generated based on the test mode. The target control information includes the target fluid path, the target heating and cooling regulation unit involved in the regulation, and the target control quantity. The valve assembly is controlled to form the target fluid path according to the target fluid path, and the second and / or first cooling and heating regulating units are controlled to participate in the cooling and heating regulation of the circulating medium in the circulation pipeline according to the target cooling and heating regulating unit. Acquire detection data, including circulating medium flow rate, soil temperature, water outlet temperature of the first and second heating and cooling units; The actual control quantity is determined based on the detection data, and the output power of the first cooling and heating unit and / or the second cooling and heating unit is adjusted according to the actual control quantity and the target control quantity, so that the difference between the target control quantity and the actual control quantity is less than the threshold. When the difference between the target control quantity and the actual control quantity is less than the threshold, test data is obtained for calculating the geotechnical thermal property parameters.

2. The method for testing the thermal properties of soil and rock under multiple working conditions according to claim 1, characterized in that: The first test mode is a constant working condition test mode with the control objective of stabilizing the inlet temperature of the buried pipe. The second test mode is a constant current test mode with heat exchange power stability as the control objective; The target control parameters include the target temperature at the inlet of the buried pipe or the target heat exchange power; Among them, the constant operating condition test mode includes the constant hot operating condition test mode and the constant cold operating condition test mode; The constant current test mode includes the constant heat flow test mode and the constant cold flow test mode.

3. The method for testing the thermal properties of soil and rock under multiple working conditions according to claim 2, characterized in that: Generate target control information based on the test mode, including: When the test mode is constant heat flow test mode, the first fluid path is selected as the target fluid path, the first heating and cooling adjustment unit is selected as the target heating and cooling adjustment unit, and the target heat exchange power is used as the target control quantity. When the test mode is constant cold flow test mode, the second fluid path is selected as the target fluid path, and the first and second cold and heat regulation units are selected as the target cold and heat regulation units, and the target heat exchange power is selected as the target control quantity. When the test mode is constant heat condition test mode or constant cold condition test mode, the second fluid path is selected as the target fluid path, and the first and second cold and heat regulation units are selected as the target cold and heat regulation units, and the target temperature of the buried pipe inlet is selected as the target control quantity. The first fluid path is the fluid path formed by connecting the circulation pipeline, the second heating and cooling unit, and the buried pipe to be tested. The second fluid path is a fluid path formed by connecting the circulation pipeline, the first heating and cooling unit, the second heating and cooling unit, and the buried pipe to be tested.

4. The method for testing the thermal properties of soil and rock under multiple working conditions according to claim 3, characterized in that: The valve assembly is controlled to form the target fluid path according to the target fluid path, and the first and / or second cooling and heating regulating units are controlled to participate in the cooling and heating regulation of the circulating medium in the circulation pipeline according to the target cooling and heating regulating unit, including: When the test mode is constant heat flow test mode, the control valve assembly forms the first fluid path and controls the second heating and cooling adjustment unit to output heating power to heat and regulate the circulating medium. When the test mode is constant cold flow test mode, the control valve assembly forms a second fluid path, controls the first cold and heat regulation unit to output cooling power, and controls the second cold and heat regulation unit to output heating power, so as to perform cold and heat coupling regulation of the circulating medium. When the test mode is constant heat condition test mode, the control valve assembly forms a second fluid path, and controls the first cooling and heating adjustment unit to output heating power, and controls the second cooling and heating adjustment unit to output heating power, so as to jointly heat and regulate the circulating medium. When the test mode is the constant cooling condition test mode, the control valve assembly forms a second fluid path, controls the first cooling and heating adjustment unit to output cooling power, and controls the second cooling and heating adjustment unit to output heating power, so as to perform cooling and heating coupling adjustment of the circulating medium.

5. The method for testing the thermal properties of soil and rock under multiple working conditions according to claim 2, characterized in that: The actual control quantity is determined based on the detection data, and the output power of the first and / or second heating / cooling unit is adjusted according to the actual and target control quantities to ensure that the difference between the target and actual control quantities is less than a threshold, including: When the target control quantity is the target temperature of the buried pipe inlet, the outlet water temperature of the second heating and cooling unit is used as the actual control quantity. The temperature difference between the outlet water temperature of the second heating and cooling unit and the target temperature of the buried pipe inlet is calculated, and the power of the first heating and cooling unit and the second heating and cooling unit is adjusted according to the temperature difference. When the target control variable is the target heat exchange power, the actual heat exchange power is determined based on the circulating medium flow rate, soil temperature, outlet water temperature of the first and second heat exchange units. The actual heat exchange power is used as the actual control variable. The power difference between the actual heat exchange power and the target heat exchange power is calculated, and the power of the first and second heat exchange units is adjusted based on the power difference.

6. The method for testing the thermal properties of soil and rock under multiple working conditions according to claim 5, characterized in that: The actual heat exchange power is determined based on the circulating medium flow rate, soil temperature, outlet water temperature of the first and second heating / cooling units, including: The heating or cooling power of the first heating and cooling unit is determined based on the circulating medium flow rate, the specific heat capacity of the circulating medium, the soil temperature, and the outlet water temperature of the first heating and cooling unit. The heating power of the second heating and cooling unit is determined based on the circulating medium flow rate, the specific heat capacity of the circulating medium, the outlet water temperature of the first heating and cooling unit, and the outlet water temperature of the second heating and cooling unit. When the test mode is constant heat flow test mode, the actual heat exchange power is determined according to the heating power of the first heating and cooling adjustment unit. When the test mode is constant cold flow test mode, the actual heat exchange power is determined based on the cooling power of the first cooling and heating adjustment unit and the heating power of the second cooling and heating adjustment unit.

7. The method for testing the thermal properties of soil and rock under multiple working conditions according to claim 6, characterized in that: The first heating and cooling unit is an air source heat pump, and the second heating and cooling unit is a heating tank; The circulating medium flow rate is the flow rate detected by the flow sensing device; The soil temperature is the temperature of the buried pipe side measured by the temperature detection device.

8. The method for testing the thermal properties of soil and rock under multiple working conditions according to claim 7, characterized in that: The outlet water temperature of the first heating and cooling unit is the outlet water temperature of the air source heat pump detected by the temperature detection device. The outlet water temperature of the second heating and cooling unit is the outlet water temperature of the heating tank detected by the temperature detection device; wherein, the outlet water temperature of the heating tank is the temperature of the circulating medium before entering the buried pipe to be tested.

9. The method for testing the thermal properties of soil and rock under multiple working conditions according to claim 8, characterized in that: The heating power of the first heating / cooling control unit is calculated using the following formula. : ； The cooling power of the first heating and cooling control unit is calculated using the following formula. : ； The heating power of the second heating / cooling control unit is calculated using the following formula. : ； in, For circulating medium flow rate, For the specific heat capacity of the circulating medium, For soil temperature, The outlet water temperature of the second heating and cooling unit. The outlet water temperature of the first heating and cooling unit.

10. The method for testing the thermophysical properties of soil and rock under multiple working conditions according to any one of claims 1 to 9, characterized in that: The test data includes at least one of the following: test mode identifier, target fluid path, circulating medium flow rate, soil temperature, outlet water temperature of the first heating and cooling unit, outlet water temperature of the second heating and cooling unit, output power of the target heating and cooling unit involved in the regulation, and test time. The output power of the target heating and cooling regulation unit involved in the regulation includes at least one of the heating power of the first heating and cooling regulation unit, the cooling power of the first heating and cooling regulation unit, and the heating power of the second heating and cooling regulation unit. The test data is used to select a calculation model for the geothermal properties of soil and rock corresponding to the test mode, in order to calculate at least one of the thermal conductivity, thermal diffusivity and volumetric specific heat capacity of soil and rock.

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