Optimized adjusting method of ground source heat pump system

Abstract

The invention relates to the technical field of ground source heat pump operation control, in particular to an optimal adjustment method of a ground source heat pump system, which comprises the following steps: S1, collecting underground soil temperature and system heat load of the ground source heat pump system; s2, calculating a soil heat balance index based on the underground soil temperature; s3, according to the soil heat balance index and the system heat load, the optimized operation mode of the ground source heat pump system is judged; and S4, according to the optimized operation mode judged in the S3, the operation parameters of the ground source heat pump system are adjusted, and a corresponding execution mechanism is driven. According to the method, the operation mode is judged by introducing the soil heat balance index and combining the system heat load, meanwhile, the flow of the circulating water pump, the frequency of the compressor and the opening degree of the heat exchange valve are subjected to interval adjustment, and unification of energy efficiency optimization and long-term balance of the soil heat environment is achieved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of ground source heat pump operation control, and particularly relates to an optimal adjustment method of a ground source heat pump system. BACKGROUND

[0002] With the popularization of building energy saving and renewable energy utilization, the ground source heat pump system is widely applied to heating, cooling and domestic hot water system because it can fully utilize the cold and heat resources in the shallow underground soil. However, in the long-term operation process, there is a continuous energy exchange between the ground source heat pump system and the soil. If there is a lack of effective operation adjustment mechanism, the underground soil temperature gradually deviates from the natural balance state, and the heat accumulation or cold accumulation phenomenon occurs, thereby reducing the heat exchange efficiency, increasing the energy consumption, and even affecting the stable operation of the system. The existing system mainly adjusts according to the instantaneous load, and cannot consider the dynamic change of the soil thermal environment, so that the operation mode selection and parameter adjustment lack long-term balance and adaptability.

[0003] Based on the above status, the existing technology has three outstanding problems: first, there is a lack of quantitative index that can comprehensively reflect the soil thermal environment state, and it is difficult to accurately determine whether the soil is in a thermal balance state; second, the switching rule of the operation mode is single, and cannot comprehensively determine the soil thermal state and the system thermal load, which easily causes energy efficiency to decrease or frequent switching; third, the adjustment of the operation parameters lacks fine control, and the core parameters such as the circulating water pump flow, the compressor frequency and the heat exchange valve opening degree cannot be dynamically optimized according to the operation mode. Therefore, an optimal adjustment method of a ground source heat pump system is needed to solve the above problems. SUMMARY

[0004] Based on the above purpose, the present application provides an optimal adjustment method of a ground source heat pump system.

[0005] An optimal adjustment method of a ground source heat pump system, comprising the following steps: S1: collecting the underground soil temperature of the ground source heat pump system and the system thermal load; S2: calculating a soil thermal balance index based on the underground soil temperature; S3: determining an optimal operation mode of the ground source heat pump system according to the soil thermal balance index and the system thermal load, including a high efficiency mode, an energy saving mode and a thermal balance mode; S4: adjusting the operation parameters of the ground source heat pump system and driving the corresponding execution mechanism according to the optimal operation mode determined in S3, wherein the operation parameters include the circulating water pump flow, the compressor operation frequency and the heat exchange valve opening degree.

[0006] Optionally, the S1 specifically comprises: S11: arranging multiple temperature sensors in vertical direction around the soil heat exchanger, covering both shallow and deep locations, and recording a unique address code for each sensor; S12: performing power-on self-test and zero-point calibration for each temperature sensor, completing time synchronization and sampling period setting; S13: collecting underground soil temperature at each depth point according to the set sampling period, generating a time-stamped soil temperature sequence; S14: setting a flow meter on the primary side of the ground source heat pump pipeline, and setting temperature sensors on the water supply pipe and return pipe to synchronously collect volume flow, water supply temperature and return water temperature; S15: correlating volume flow and water supply-return temperature difference within the same time window by the controller to generate real-time heat exchange data of the system heat load.

[0007] Optionally, the S15 specifically includes: S151: setting a fixed length time window and a sliding step in the controller, and timestamping the raw data of the flow meter, water supply temperature sensor and return water temperature sensor; S152: in each time window, performing denoising and time alignment processing on the volume flow sequence to calculate the representative value of the volume flow in the window; S153: in the same time window, calculating the difference sequence of the water supply temperature and the return water temperature, and performing denoising and time alignment processing to calculate the representative value of the temperature difference in the window; S154: correlating the representative value of the volume flow and the representative value of the temperature difference corresponding to the window one by one to generate real-time heat exchange data records with timestamps; S155: performing data validity discrimination, when the volume flow is zero, marking the corresponding window data as invalid and not generating heat exchange data; when the temperature difference is zero, generating zero-value heat exchange data.

[0008] Optionally, the S2 specifically includes: S21: receiving the underground soil temperature obtained by S1, and collecting the data in the same window according to the time window set by the controller to form a temperature data set arranged by time; S22: according to the depth layering strategy and the preset weight table, layering and aggregating the temperature data set to obtain a comprehensive soil temperature for representing the heat state of the heat exchange region; S23: calling the seasonal soil reference temperature corresponding to the site location and the current date from the historical database; S24: comparing the comprehensive soil temperature with the seasonal soil reference temperature to determine the temperature deviation; S25: According to the soil heat capacity coefficient corresponding to the on-site soil type, the temperature deviation is normalized and converted to generate a soil heat balance index.

[0009] Optionally, the S22 specifically includes: S221: Establish a depth stratification strategy to determine the number of stratifications from top to bottom and the upper and lower boundaries of the depth thereof; S222: According to the installation depth of each temperature sensor, map the temperature data obtained in S1 to the corresponding stratification to form a set of in-layer temperature data; S223: For each stratification, calculate the representative temperature of the corresponding layer ; S224: Read the weight coefficient of each stratification from a preset weight table ; S225: Perform weighted aggregation on the representative temperature of each layer to obtain a comprehensive soil temperature for representing the heat state of the heat exchange region .

[0010] Optionally, the S25 specifically includes: S251: Receive the comprehensive soil temperature obtained in S22 and the seasonal soil reference temperature obtained in S23 to calculate the temperature deviation ; S252: Determine the soil type according to the on-site survey results, and read the corresponding volumetric heat capacity coefficient from a preset soil heat capacity coefficient table ; S253: Perform energy magnitude conversion on the temperature deviation and the volumetric heat capacity coefficient to obtain a volumetric energy disturbance amount, and the conversion formula is: ; wherein, is the volumetric energy disturbance amount; S254: Normalize the volumetric energy disturbance amount using a design reference volumetric energy threshold to generate a soil heat balance index .

[0011] Optionally, the S3 specifically includes: S31: Receive the soil heat balance index and the system heat load in the current time window; S32: Call a preset threshold set, the threshold set including a first threshold and a second threshold for the soil heat balance index, and a low load threshold and a high load threshold for the system heat load, forming three index intervals and three load intervals; ​​S33: determining the priority of the mode according to the interval of the soil heat balance index: setting the high efficiency mode as the priority when the absolute value of the index is lower than a first threshold value; setting the energy saving mode as the priority when the absolute value of the index is between the first threshold value and a second threshold value; setting the heat balance mode as the priority when the absolute value of the index is higher than the second threshold value; S34: making a final decision on the priority of the mode in combination with the interval of the system heat load: determining the high efficiency mode when the absolute value of the index is lower than the first threshold value; determining the heat balance mode for the low load interval and the energy saving mode for the medium load and high load intervals when the absolute value of the index is between the first threshold value and the second threshold value; determining the heat balance mode for any load interval when the absolute value of the index is higher than the second threshold value; S35: setting a minimum holding time and a switching inhibition condition for the mode determination result in the adjacent time window, maintaining the current mode when the holding time is not reached, and updating the mode when the switching condition is triggered and the new mode meets the decision result.

[0012] Optionally, the S35 specifically includes: S351: setting a minimum holding time threshold value in the controller; S352: maintaining the current mode unchanged when the newly determined mode in the adjacent time window is the same as the mode determined in the previous window and the cumulative holding time does not reach the minimum holding time threshold value; S353: ignoring the switching request and maintaining the previous mode when the newly determined mode in the adjacent time window is different from the mode determined in the previous window and the cumulative holding time is less than the minimum holding time threshold value; S354: setting the switching inhibition condition, including the continuous time length of the soil heat balance index deviating from the preset threshold value interval, the number of times the system heat load exceeds the interval boundary, and the cooling time after the mode switching; S355: confirming the mode switching and updating the new mode as the current effective mode when the minimum holding time and the switching inhibition condition are both met; S356: resetting the holding time timer and the switching inhibition condition counter after completing the mode switching, and entering a new round of determination cycle.

[0013] Optionally, the S4 specifically includes: S41: when the determined mode is the high efficiency mode, the controller gradually increases the circulating water pump flow to 90%-100% of the rated flow, increases the compressor frequency to 85%-95% of the rated frequency, and keeps the heat exchange valve opening in the interval of 80%-100%; S42: When the mode is determined as the energy saving mode, the controller adjusts the circulating water pump flow to 60-80% of the rated flow, adjusts the compressor frequency to 60-75% of the rated frequency, and keeps the heat exchange valve opening in the range of 50-70%; S43: When the mode is determined as the thermal balance mode, the controller performs differentiated adjustment according to the positive or negative direction of the soil thermal balance index; When the index is positive deviation, the circulating water pump flow is adjusted to 50-70% of the rated flow, the compressor frequency is adjusted to 50-65% of the rated frequency, and the valve opening is adjusted to 40-60%; When the index is negative deviation, the circulating water pump flow is adjusted to 80-95% of the rated flow, the compressor frequency is adjusted to 70-85% of the rated frequency, and the valve opening is adjusted to 60-80%.

[0014] Optionally, the S4 further comprises: S44: The adjusted parameters are converted into pulse width modulation signals or analog voltage signals, and are sent to the corresponding water pump, compressor and valve actuator to complete the closed-loop adjustment of the operating parameters.

[0015] The beneficial effects of the present application are: The present application can quantitatively characterize the underground soil temperature state by introducing the soil thermal balance index during operation, and comprehensively determines the system thermal load, so that the selection of the operation mode is no longer dependent on the instantaneous load, but also takes into account the long-term stability of the soil thermal environment, thereby avoiding the problems of heat accumulation and cold accumulation.

[0016] The present application realizes fine dynamic adjustment of operating parameters by configuring specific circulating water pump flow, compressor frequency and heat exchange valve opening parameter intervals for different operation modes; therefore, both energy efficiency in the high efficiency mode and energy saving in the energy saving mode can be ensured, and the soil thermal environment stability in the thermal balance mode can be maintained, realizing the unity of system efficiency and soil sustainability. BRIEF DESCRIPTION OF DRAWINGS

[0017] In order to more clearly illustrate the technical solutions in the present application or prior art, the following will briefly introduce the drawings needed to be used in the embodiments or prior art description. Obviously, the drawings in the following description only illustrate the present application, and for those skilled in the art, other drawings can also be obtained without creative labor.

[0018] Fig. 1 The schematic diagram of the optimization adjustment method of the embodiment of the present application; Fig. 2 The flowchart of calculating the soil thermal balance index of the embodiment of the present application. DETAILED DESCRIPTION

[0019] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments. It should also be noted that, to make the embodiments more comprehensive, the following embodiments are the best and preferred embodiments, and those skilled in the art can use other alternative methods to implement some well-known technologies; moreover, the accompanying drawings are only for more specific description of the embodiments and are not intended to specifically limit the present invention.

[0020] It should be noted that the use of terms such as "an embodiment," "an embodiment," "an exemplary embodiment," and "some embodiments" in the specification indicates that the described embodiment may include a specific feature, structure, or characteristic, but not every embodiment necessarily includes that specific feature, structure, or characteristic. Furthermore, when a specific feature, structure, or characteristic is described in connection with an embodiment, implementing such a feature, structure, or characteristic in conjunction with other embodiments (whether explicitly described or not) should be within the knowledge of those skilled in the art.

[0021] Generally, terms can be understood at least partly from their use in context. For example, depending at least partly on the context, the term "one or more" as used herein can be used to describe any feature, structure, or characteristic in a singular sense, or a combination of features, structures, or characteristics in a plural sense. Additionally, the term "based on" can be understood not necessarily to convey an exclusive set of factors, but rather, alternatively, depending at least partly on the context, to allow for the presence of other factors that are not necessarily explicitly described.

[0022] like Figs. 1-2 As shown, an optimization and adjustment method for a ground source heat pump system includes the following steps: S1: Collects the underground soil temperature and system heat load of the ground source heat pump system; S2: Calculate the soil heat balance index based on underground soil temperature; S3: Determine the optimal operating mode of the ground source heat pump system based on the soil heat balance index and system heat load, including high-efficiency mode, energy-saving mode and heat balance mode. S4: Based on the optimized operating mode determined by S3, adjust the operating parameters of the ground source heat pump system and drive the corresponding actuators. The operating parameters include the circulating water pump flow rate, the compressor operating frequency, and the opening degree of the heat exchange valve.

[0023] S1 specifically includes: S11: Multiple temperature sensors are arranged vertically around the soil heat exchanger, covering both shallow and deep locations, and a unique address code is recorded for each sensor. S12: Perform power-on self-test and zero-point calibration on each temperature sensor, and complete time synchronization and sampling period setting; S13: Collecting the underground soil temperature of each depth point according to the set sampling period to generate a time-stamped soil temperature sequence; S14: Setting a flow meter in the primary side pipeline of the ground source heat pump, and setting temperature sensors in the water supply pipe and the return pipe to synchronously collect the volume flow, the water supply temperature and the return water temperature; S15: Associating the volume flow and the temperature difference between the water supply and return in the same time window by the controller to generate real-time heat exchange data of the system heat load; the above steps ensure the completeness of the underground soil temperature field representation and the real-time of the system heat load measurement through the step-by-step acquisition mechanism of vertical multi-point coverage, synchronous acquisition and time alignment, providing a consistent time reference and stable data source for the soil heat balance index calculation in step S2 and the operation mode determination in step S3.

[0024] S15 specifically includes: S151: Setting a fixed length time window and a sliding step in the controller to unify the time stamp of the original data of the flow meter, the water supply temperature sensor and the return water temperature sensor; S152: In each time window, performing denoising and time alignment processing on the volume flow sequence to calculate the volume flow representative value of the window; The calculation principle of the volume flow representative value is as follows: in a fixed time window, the flow meter will output instantaneous volume flow data multiple times; since a single sampling value may fluctuate or have noise, if the flow value of a certain sampling is directly used, it may lead to unstable calculation results; by adding all the sampling values in the time window and dividing by the number of samplings, the average volume flow in the time period is obtained, which can reflect the overall flow level of the time window, thereby avoiding the deviation caused by instantaneous fluctuations; S153: In the same time window, calculate the temperature difference sequence of the water supply temperature and the return water temperature, and perform denoising and time alignment processing to calculate the temperature difference representative value of the window; The calculation principle of the temperature difference representative value is as follows: in the same time window, the water supply temperature and the return water temperature are collected multiple times; if only one temperature difference is taken, it may be distorted due to measurement noise or instantaneous disturbance; by averaging all the sampled temperature differences in the window, a more stable temperature difference value can be obtained, which reflects the overall heat exchange of the heat pump system in the time period; in other words, the average temperature difference can eliminate short-term fluctuations, making the temperature difference result closer to the real system operating state; S154: Associating the volume flow representative value and the temperature difference representative value corresponding to the window one by one to generate a time-stamped real-time heat exchange data record; The expression of real-time heat exchange is: , wherein, Q is the real-time heat exchange, is the density of the circulating working medium, is the specific heat capacity of the circulating working medium, is the volume flow representative value, is the temperature difference representative value; The essence of the system heat load is the heat carried by the fluid in the process of passing through the heat exchanger; according to the basic principle of thermodynamics, the heat is equal to the mass flow of the fluid multiplied by its specific heat capacity and then multiplied by the temperature change; in the formula, is the result of converting the volume flow into the mass flow, indicating the mass of the fluid passing through per unit time; is the specific heat capacity of the fluid, indicating the heat absorbed or released by the unit mass of the fluid when the temperature rises by one degree; is the temperature difference of the supply and return water, reflecting the temperature rise and fall amplitude of the fluid when passing through the heat exchanger; the three are multiplied to obtain the actual heat exchange per unit time, that is, the real-time heat load of the system; S155: execute data validity discrimination, when the volume flow is zero, mark the corresponding window data as invalid and do not generate heat exchange quantity record; when the temperature difference is zero, generate zero value heat exchange quantity record; the above belongs to step by introducing volume flow average, temperature difference average and heat exchange quantity calculation formula in each sub-step, guaranteeing the consistency of the collected data in time dimension and the calculability in numerical dimension, so as to obtain stable system heat load representation in real time, ensuring to provide accurate basis for the operation mode judgment of step S3.

[0025] S2 specifically includes: S21: receive the underground soil temperature obtained by S1, and collect the data in the same window according to the time window set by the controller, to form a temperature data set arranged by time; S22: according to the stratification strategy and the preset weight table, the temperature data set is stratified and aggregated to obtain a comprehensive soil temperature for representing the heat state of the heat exchange region; S23: call the seasonal soil reference temperature corresponding to the site location and the current date from the historical database; S24: compare the comprehensive soil temperature with the seasonal soil reference temperature to determine the temperature deviation; S25: according to the soil heat capacity coefficient corresponding to the on-site soil type, the temperature deviation is normalized and converted to generate a soil heat balance index; the above steps can obtain the soil heat balance index with physical meaning by stratified aggregation of the comprehensive soil temperature, comparison with the seasonal reference temperature and normalization conversion combined with the soil heat capacity coefficient, so that the index can accurately reflect the heat balance state of the current underground soil and provide basis for the optimized operation mode judgment of step S3.

[0026] S22 specifically includes: S221: Establish a depth stratification strategy to determine the layers from top to bottom S222: According to the installation depth of each temperature sensor, map the temperature data obtained in S1 to the corresponding layer to form a set of in-layer temperature data; S223: For each layer, calculate the representative temperature of the corresponding layer , the expression is: , where, is the number of sensors in the layer; is the temperature of the sensor in the layer; is the representative temperature of the layer; S224: Read the weight coefficients of each layer from the preset weight table ; S225: Perform weighted aggregation on the representative temperature of each layer to obtain the comprehensive soil temperature for representing the heat state of the heat exchange area , the expression is: , where, is the weight of the layer; is the comprehensive soil temperature; The above steps, through stratification aggregation based on depth and preset weight weighting, can accurately represent the heat contribution and actual heat state of the heat exchange area at different depths, improve the representativeness and stability of the subsequent soil heat balance index calculation, provide reliable input for the operation mode determination of S3, and reduce the influence of single-point measurement fluctuation on decision-making.

[0027] Table 1: Preset weight table

[0028] S25 specifically includes: S251: Receive the comprehensive soil temperature obtained in S22 and the seasonal soil reference temperature obtained in S23, and calculate the temperature deviation , the formula is: , where, is the seasonal soil reference temperature; S252: Determine the soil type according to the field survey results, and read the corresponding volumetric heat capacity coefficient from the preset soil heat capacity coefficient table ; Table 2: Soil heat capacity coefficient table

[0029] ​​​S253: The temperature deviation is energy magnitude converted with the volumetric heat capacity to obtain a volumetric energy perturbation, and the conversion formula is: ; wherein, is the volumetric energy perturbation; S254: The volumetric energy perturbation is normalized by using a design reference volumetric energy threshold to generate a soil heat balance index , and the formula is: , wherein, is the design reference volumetric energy threshold, is the soil heat balance index; the above steps obtain the soil heat balance index with consistent physical dimensions, cross-season comparability, and direct threshold determination, by forming the temperature deviation from the comprehensive soil temperature and the seasonal reference temperature, and then normalizing the reference threshold after energy magnitude conversion with the volumetric heat capacity, thereby providing a stable and engineering meaningful input for the optimized operation mode determination of step S3.

[0030] S3 specifically includes: S31: Receive the soil heat balance index and the system heat load in the current time window; S32: Call a preset threshold set, the threshold set including a first threshold and a second threshold for the soil heat balance index, and a low load threshold and a high load threshold for the system heat load, to form three index intervals and three load intervals; S33: Determine the mode priority according to the interval attribution of the soil heat balance index: set the high efficiency mode as the priority when the index absolute value is lower than the first threshold; set the energy saving mode as the priority when the index absolute value is between the first threshold and the second threshold; and set the heat balance mode as the priority when the index absolute value is higher than the second threshold; S34: Make a final decision on the mode priority in combination with the interval of the system heat load: when the index absolute value is lower than the first threshold, any load interval is determined as the high efficiency mode; when the index absolute value is between the first threshold and the second threshold, the low load interval is determined as the heat balance mode, and the medium load and high load intervals are determined as the energy saving mode; and when the index absolute value is higher than the second threshold, any load interval is determined as the heat balance mode; S35: Set a minimum holding time and a switching inhibition condition for the mode determination result in the adjacent time window, maintain the current mode if the holding time is not reached, and update the mode when the switching condition is triggered and the new mode meets the decision result; the above steps can ensure the recovery ability of the soil thermal environment while taking into account the energy consumption and heating and cooling demand, to obtain a stable and executable operation mode determination result, thereby providing clear and continuous control basis for the parameter adjustment of step S4.

[0031] S35 specifically includes: S351: Set a minimum holding time threshold in the controller, which corresponds to the shortest time length required to maintain the consistency of the running mode in the case of continuous determination results; S352: When the new determination mode in the adjacent time window is the same as the previous window determination mode and the cumulative holding time does not reach the minimum holding time threshold, the controller maintains the current mode unchanged; S353: When the new determination mode in the adjacent time window is different from the previous window determination mode and the cumulative holding time is less than the minimum holding time threshold, the controller ignores this switching request and maintains the previous mode; S354: Set the switching inhibition condition, including the continuous time length of the soil heat balance index deviating from the preset threshold interval, the number of times the system heat load exceeds the interval boundary, and the cooling time after mode switching; S355: When the minimum holding time and the switching inhibition condition are met at the same time, the controller confirms the mode switching, and updates the new mode as the current effective mode; S356: After completing the mode switching, reset the holding time timer and the switching inhibition condition counter, and enter a new round of determination period; The above steps avoid frequent mode switching caused by short-term fluctuations or accidental abnormal data by introducing the minimum holding time and the switching inhibition condition in the adjacent time window, thereby ensuring the stability and continuity of the running mode, and providing reliable control input for the running parameter adjustment of step S4.

[0032] S4 specifically includes: S41: When the determination mode is the high efficiency mode, the controller gradually increases the circulating water pump flow to 90%-100% of the rated flow, increases the compressor frequency to 85%-95% of the rated frequency, and keeps the heat exchange valve opening in the interval of 80%-100%; S42: When the determination mode is the energy saving mode, the controller reduces the circulating water pump flow to 60%-80% of the rated flow, reduces the compressor frequency to 60%-75% of the rated frequency, and keeps the heat exchange valve opening in the interval of 50%-70%; S43: When the determination mode is the heat balance mode, the controller performs differentiated adjustment according to the positive and negative directions of the soil heat balance index; When the index is positive deviation, reduce the circulating water pump flow to 50%-70% of the rated flow, the compressor frequency to 50%-65% of the rated frequency, and the valve opening to 40%-60%; When the index is negative deviation, increase the circulating water pump flow to 80%-95% of the rated flow, the compressor frequency to 70%-85% of the rated frequency, and the valve opening to 60%-80%.

[0033] S4 further comprises: S44: the adjusted parameters are converted into pulse width modulation signals or analog voltage signals, and are sent to corresponding water pumps, compressors and valve actuators to complete closed-loop regulation of the operating parameters; the above steps achieve closed-loop regulation by directly corresponding different operating modes to specific operating parameter intervals and driving the execution mechanism with controller output signals, avoid the redundancy of transitional steps, make the parameter adjustment process more concise and clear, and enable rapid implementation of accurate control of the circulating water pump, compressor and valve, and improve the regulation efficiency and operating reliability of the ground source heat pump system under different operating conditions.

[0034] The present application encompasses any substitutions, modifications, equivalent methods and schemes made on the essence and scope of the present application. In order for the public to have a thorough understanding of the present application, specific details are described in the following preferred embodiments of the present application, and the present application can also be fully understood without the description of these details by those skilled in the art. In addition, in order to avoid unnecessary confusion to the essence of the present application, well-known methods, processes, procedures, elements and circuits, etc. are not described in detail.

[0035] The above is only the preferred embodiment of the present application, and it should be pointed out that for those skilled in the art, without departing from the principle of the present application, a number of improvements and refinements can be made, and these improvements and refinements should also be considered as the protection scope of the present application.

Claims

1. An optimized adjustment method for a ground source heat pump system, characterized in that, Includes the following steps: S1: Collects the underground soil temperature and system heat load of the ground source heat pump system; S2: Calculate the soil heat balance index based on underground soil temperature; S3: Determine the optimal operating mode of the ground source heat pump system based on the soil heat balance index and system heat load, including high-efficiency mode, energy-saving mode and heat balance mode. S4: Based on the optimized operating mode determined in S3, adjust the operating parameters of the ground source heat pump system and drive the corresponding actuators. The operating parameters include the circulating water pump flow rate, the compressor operating frequency, and the opening degree of the heat exchange valve.

2. The optimization and adjustment method for a ground source heat pump system according to claim 1, characterized in that, S1 specifically includes: S11: Multiple temperature sensors are arranged vertically around the soil heat exchanger, covering both shallow and deep locations, and a unique address code is recorded for each sensor. S12: Perform power-on self-test and zero-point calibration on each temperature sensor, and complete time synchronization and sampling period setting; S13: Collect the underground soil temperature at each depth point according to the set sampling period and generate a soil temperature sequence with timestamps; S14: Install a flow meter on the primary side of the ground source heat pump and install temperature sensors on the supply and return water pipes respectively to collect volumetric flow rate, supply water temperature and return water temperature simultaneously. S15: The controller correlates the volumetric flow rate within the same time window with the temperature difference between the supply and return water to generate real-time heat exchange data of the system's heat load.

3. The optimization and adjustment method for a ground source heat pump system according to claim 2, characterized in that, S15 specifically includes: S151: Set a fixed-length time window and sliding step in the controller to unify the timestamps of the raw data from the flow meter, supply water temperature sensor and return water temperature sensor. S152: Within each time window, perform denoising and time alignment on the volumetric flow rate sequence, and calculate the representative value of the volumetric flow rate for the window. S153: Within the same time window, calculate the sequence of differences between the supply water temperature and the return water temperature, and perform noise reduction and time alignment processing to calculate the representative value of the temperature difference within the window. S154: Associate the volumetric flow rate representative value and the temperature difference representative value of the corresponding window one by one to generate a real-time heat exchange data record with a timestamp. S155: Perform data validity judgment. When the volumetric flow rate is zero, mark the corresponding window data as invalid and do not generate a heat exchange quantity record; when the temperature difference is zero, generate a zero-value heat exchange quantity record.

4. The optimization and adjustment method for a ground source heat pump system according to claim 1, characterized in that, S2 specifically includes: S21: Receive the underground soil temperature obtained by S1, and collect the data within the same window according to the time window set by the controller to form a temperature dataset arranged by time; S22: Based on the burial depth stratification strategy and the preset weight table, the temperature dataset is stratified and aggregated to obtain the comprehensive soil temperature used to characterize the thermal state of the heat exchange area. S23: Retrieve the seasonal soil baseline temperature corresponding to the site location and current date from the historical database; S24: Compare the overall soil temperature with the seasonal soil baseline temperature to determine the temperature deviation; S25: Based on the soil heat capacity coefficient corresponding to the soil type on site, perform normalization conversion on the temperature deviation to generate the soil heat balance index.

5. The optimization and adjustment method for a ground source heat pump system according to claim 4, characterized in that, S22 specifically includes: S221: Establish a stratified burial depth strategy to determine the top-to-bottom order. Each layer and its burial depth upper and lower limits ; S222: Based on the installation depth of each temperature sensor, map the temperature data acquired by S1 to the corresponding layer. This forms a set of temperature data within the layer; S223: For each layer, calculate the representative temperature of the corresponding layer. ; S224: Read the weight coefficients of each layer from the preset weight table. ; S225: Perform weighted aggregation on the representative temperatures of each layer to obtain the comprehensive soil temperature used to characterize the thermal state of the heat transfer zone. .

6. The optimization and adjustment method for a ground source heat pump system according to claim 4, characterized in that, Specifically, S25 includes: S251: Receive the composite soil temperature obtained from S22 and the seasonal soil reference temperature obtained from S23, and calculate the temperature deviation. ; S252: Determine the soil type based on the on-site survey results, and read the corresponding volumetric heat capacity coefficient from the preset soil heat capacity coefficient table. ; S253: Convert the temperature deviation to the volumetric heat capacity coefficient using energy magnitude conversion to obtain the volumetric energy disturbance. The conversion formula is as follows: ;in, This refers to the volumetric energy perturbation. S254: The volumetric energy disturbance is normalized using the design reference volumetric energy threshold to generate the soil heat balance index. .

7. The optimization and adjustment method for a ground source heat pump system according to claim 1, characterized in that, S3 specifically includes: S31: Receive the soil thermal balance index and system thermal load within the current time window; S32: Call the preset threshold set, which includes a first threshold and a second threshold for the soil heat balance index, and a low load threshold and a high load threshold for the system heat load, forming three index intervals and three load intervals. S33: Determine the mode priority based on the interval assignment of the soil heat balance index: when the absolute value of the index is lower than the first threshold, the high efficiency mode is set as the priority; when the absolute value of the index is between the first threshold and the second threshold, the energy-saving mode is set as the priority; when the absolute value of the index is higher than the second threshold, the heat balance mode is set as the priority. S34: Make a final decision on the mode priority based on the system heat load range: when the absolute value of the index is lower than the first threshold, any load range is determined to be the high-efficiency mode; when the absolute value of the index is between the first threshold and the second threshold, the low load range is determined to be the thermal balance mode, and the medium and high load ranges are determined to be the energy-saving mode; when the absolute value of the index is higher than the second threshold, any load range is determined to be the thermal balance mode. S35: Set a minimum holding time and switching suppression conditions for the mode determination results within adjacent time windows. Maintain the current mode if the holding time is not reached, and update the mode when the switching condition is triggered and the new mode meets the decision result.

8. The optimized adjustment method for a ground source heat pump system according to claim 7, characterized in that, Specifically, S35 includes: S351: Set the minimum hold duration threshold in the controller; S352: When the new judgment mode in an adjacent time window is the same as the judgment mode in the previous window and the cumulative holding time has not reached the minimum holding time threshold, the controller maintains the current mode unchanged. S353: When the new judgment mode in an adjacent time window is different from the judgment mode in the previous window and the cumulative holding time is less than the minimum holding time threshold, the controller ignores the switching request and maintains the previous mode. S354: Set switching suppression conditions, including the duration of continuous deviation of the soil heat balance index from the preset threshold range, the number of times the system heat load exceeds the range boundary, and the cooling time after mode switching. S355: When both the minimum hold time and the switching suppression condition are met, the controller confirms the mode switch and updates the new mode to the currently valid mode; S356: After completing the mode switch, reset the hold duration timer and the switch suppression condition counter, and enter a new round of judgment cycle.

9. The optimization and adjustment method for a ground source heat pump system according to claim 1, characterized in that, S4 specifically includes: S41: When the judgment mode is high efficiency mode, the controller will gradually increase the flow rate of the circulating water pump to 90%-100% of the rated flow rate, increase the compressor frequency to 85%-95% of the rated frequency, and keep the opening of the heat exchange valve in the range of 80%-100%. S42: When the judgment mode is energy saving mode, the controller will reduce the flow rate of the circulating water pump to 60%-80% of the rated flow rate, reduce the compressor frequency to 60%-75% of the rated frequency, and keep the opening of the heat exchange valve in the range of 50%-70%. S43: When the judgment mode is thermal balance mode, the controller performs differentiated adjustment based on the positive and negative directions of the soil thermal balance index. When the index deviates positively, reduce the circulating water pump flow rate to 50%-70% of the rated flow rate, the compressor frequency to 50%-65% of the rated frequency, and the valve opening to 40%-60%. When the index deviates negatively, increase the circulating water pump flow rate to 80%-95% of the rated flow rate, the compressor frequency to 70%-85% of the rated frequency, and the valve opening to 60%-80%.

10. The method for optimizing and adjusting a ground source heat pump system according to claim 9, characterized in that, S4 further includes: S44: The adjusted parameters are converted into pulse width modulation signals or analog voltage signals and sent to the corresponding water pumps, compressors and valve actuators to complete the closed-loop regulation of operating parameters.

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