Solar cross-seasonal heat storage and release ground source heat pump system and balance control method and device

Abstract

The invention relates to a solar cross-seasonal heat storage and release ground source heat pump system and a balance control method and device, and relates to the technical field of ground source heat pump systems. The ground source heat pump subsystem comprises a ground heat exchanger group which is arranged in a partitioned manner; and the cross-seasonal heat storage device is used for storing and releasing solar heat and is thermally coupled with the buried pipe heat exchanger group, the cross-seasonal heat storage device is of an underground concrete structure, and three temperature gradient areas of a high-temperature layer, a medium-temperature layer and a low-temperature layer are arranged in the cross-seasonal heat storage device. Through the synergistic effect of the dynamic load distribution mechanism and the layered heat storage strategy, the problem of soil cold and heat accumulation caused by long-term operation of the ground source heat pump system can be effectively relieved. Differential design of the core heat exchange area and the buffer temperature adjustment area is combined with a multi-objective optimization algorithm, so that the difference value of annual accumulated heat taking capacity and heat supplementing capacity is controlled within 5%, and the self-recovery capacity of the soil thermal field is remarkably improved.

Description

Technical Field

[0001] The present application relates to the technical field of ground source heat pump systems, and in particular to a solar energy cross-seasonal heat storage and release ground source heat pump system, a balance control method and a device. Background Art

[0002] Long-term operation of traditional ground-source heat pump systems can easily lead to soil thermal imbalance. Due to the lack of a dynamic regulation mechanism, it's difficult to accurately match heat supply and heat withdrawal loads, leading to a continuous deterioration of the ground temperature field. Interseasonal heat storage devices generally struggle to maintain thermal stratification, and unplanned heat loss severely impacts heat storage density and utilization efficiency.

[0003] In existing technologies, multi-energy coupling systems often adopt a fixed operating mode and are unable to intelligently switch energy supply strategies according to seasonal operating conditions and load demands, resulting in energy waste and equipment loss.

[0004] Furthermore, the system's safety protection mechanisms often rely on single-threshold control, making it difficult to quickly respond to sudden changes in thermal parameters under extreme operating conditions, posing a risk of insufficient operational reliability. These technical bottlenecks restrict the deep synergy between ground-source heat pumps and renewable energy, necessitating breakthroughs through innovative thermal coupling modeling and intelligent control methods. Summary of the Invention

[0005] The purpose of this application is to provide a solar energy cross-seasonal heat storage and release geothermal heat pump system, a balance control method and a device, which solves the technical problems caused by the long-term operation of the existing geothermal heat pump system, the difficulty in maintaining thermal stratification of the cross-seasonal heat storage device, the inflexible switching of the energy supply mode, and the insufficient system reliability under extreme working conditions.

[0006] In the first aspect, the present application provides a solar inter-seasonal heat storage and release geothermal heat pump system, comprising: A solar thermal collection subsystem for collecting and storing solar heat; The ground source heat pump subsystem includes a group of buried pipe heat exchangers arranged in zones; The inter-seasonal heat storage device is used to store and release solar heat and is thermally coupled with the ground pipe heat exchanger group.

[0007] Preferably, the buried heat exchanger group of the ground source heat pump subsystem is divided into a core heat exchange area and a buffer temperature adjustment area, and the load distribution ratio satisfies the following dynamic adjustment equation: in: Q core (t): load of the core heat exchange area at time t; Q adjust (t): load of the buffer temperature control zone at time t; Q total(t): total load demand of the system at time t; α(t): Dynamic adjustment coefficient of the core area, based on the real-time monitored soil temperature T soil (t) and ambient temperature T ambient (t) calculation; β(t): dynamic adjustment coefficient of the temperature adjustment zone, satisfying β(t) = 1-α(t).

[0008] Preferably, the inter-seasonal heat storage device is an underground concrete structure, which is provided with three temperature gradient zones including a high temperature layer, a medium temperature layer and a low temperature layer.

[0009] Preferably, the solar heat collection subsystem comprises a vacuum tube-phase change thermal storage integrated collector, the heat storage density of which is not less than 180MJ / m 3 .

[0010] In a second aspect, the present application provides a balance control method comprising the following steps: Decision-making on inter-seasonal heat supplementation based on soil heat balance; Switch heating and cooling modes according to seasonal conditions; Dynamically adjust the load distribution ratio of the buried pipe heat exchange area; Implement temperature-stratified heat storage and priority extraction strategies.

[0011] Preferably, the cross-seasonal heat supplementation decision is to calculate the amount of heat supplementation by the following soil heat balance equation: Q storage =α·A solar ·G-β·(T soil -T ambient )-Q heatpump ; in: α is the solar energy conversion coefficient, A solar is the effective area of ​​the collector, G is the solar irradiance, β is the soil heat dissipation coefficient, T soil is the soil temperature, T ambient is the ambient temperature, Q heatpump Take heat for the heat pump.

[0012] Preferably, the dynamic adjustment process is implemented through a multi-objective optimization model, and the objective function is: in: Q solar To supplement the heat of solar energy, Q geo Heat for ground source heat pump, COP sys is the system real-time energy efficiency ratio, COP target is the preset energy efficiency target value; ω1, ω2 are weight coefficients.

[0013] Preferably, the seasonal operating condition switching includes: When the temperature of the high-temperature layer of the heat storage device is ≥60°C, it switches to the direct heat pump mode; When the temperature of the heat storage device is less than 35℃, it switches to the buried pipe heating mode.

[0014] In a third aspect, the present application provides a coupling device, comprising: a first heat pipe loop connecting the solar heat collection subsystem and the heat storage device; A second heat pipe loop connecting the heat storage device and the buried heat exchanger group; Multi-condition switching valve group is used to select the flow direction of the heat source.

[0015] Preferably, the switching conditions of the multi-mode switching valve group include: When the temperature of the high temperature layer of the heat storage device is ≥60°C, the first heat pipe loop is started to directly pass through the heat pump evaporator; When the temperature of the mesolayer of the heat storage device is ≥40°C, the second heat pipe loop is started in parallel to supplement heat.

[0016] In summary, this application includes at least one of the following beneficial technical effects: 1. The present invention can effectively alleviate the problem of soil heat and cold accumulation caused by the long-term operation of the ground source heat pump system through the synergistic effect of the dynamic load distribution mechanism and the layered heat storage strategy. The differentiated design of the core heat exchange area and the buffer temperature adjustment area is combined with the multi-objective optimization algorithm to control the difference between the annual cumulative heat intake and heat replenishment within 5%, significantly improving the self-recovery ability of the soil thermal field; 2. The present invention adopts a combined design of temperature priority extraction strategy and three-circuit switching device to achieve efficient spatiotemporal matching of solar energy and geothermal energy. The layered heat storage structure prioritizes the use of heat from the high-temperature layer to meet immediate needs, and the heat from the medium and low temperature layers is used for geothermal field regulation, which increases the overall energy efficiency of the system by more than 20%; 3. This invention utilizes a hierarchical control method based on a fuzzy decision tree, combined with a thermal short-circuit suppression structure design, to effectively extend the heat retention period of the heat storage device. The synergistic effect of the high-temperature layer's honeycomb fins for enhanced heat exchange and the basalt baffles' thermal resistance regulation reduces unintended heat loss to less than 30% of that of a traditional single-layer heat storage structure. 4. This invention combines a dual-threshold protection mechanism with a multi-mode switching strategy to maintain system stability under extreme operating conditions. The redundant design of the emergency cooling system and pressure relief device, combined with a closed-loop control algorithm, reduces fault response time to less than 500 milliseconds, significantly reducing the risk of system downtime. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 This is the system architecture diagram of this application; Figure 2 It is a flow chart of the method of this application. DETAILED DESCRIPTION

[0018] The following is combined with Figure 1 -Attached Figure 2 , further details of this application are given.

[0019] Example 1: A solar-powered, seasonally-storing geothermal heat pump system comprising: A solar thermal collection subsystem for collecting and storing solar heat; The present invention discloses a specific implementation of the solar thermal collection subsystem in a solar inter-seasonal heat storage and release geothermal heat pump system. The subsystem realizes efficient collection and storage of solar energy through composite structure design and intelligent control. The specific technical solution includes the following contents: The solar thermal collection subsystem adopts a vacuum tube-phase change thermal storage integrated collector, and the inner wall of the vacuum glass tube is coated with a selective absorption coating to enhance the photothermal conversion efficiency. The coating is preferably an aluminum nitride oxide multilayer composite structure, with an absorptivity of not less than 0.92 in the 0.3-2.5μm band, and an infrared emissivity controlled below 0.12. A micron-level texture structure is provided on the surface of the coating, which extends the optical path length through multiple reflection effects, effectively improving the ability to capture solar radiation energy.

[0020] The collector's interlayer is encapsulated with an inorganic hydrated salt phase-change material, preferably a sodium acetate trihydrate-based composite material with a phase-change temperature range of 58-62°C and a latent heat value of no less than 220 kJ / kg. An expanded graphite-based thermal conductivity enhancement medium is filled between the phase-change material and the heat-absorbing fins, forming a three-dimensional network of heat transfer channels. This design allows absorbed solar energy to be instantly stored in the phase-change material, avoiding the transient heat loss associated with conventional collectors due to insufficient heat capacity.

[0021] The heat flow channel adopts a copper-aluminum composite heat pipe structure, the evaporation section is embedded in the vacuum tube, and the condensation section is connected to the cross-seasonal heat storage device. The heat pipe working fluid is preferably acetone, the filling volume is 25-30% of the tube cavity volume, and the working pressure is maintained at 0.3-0.5MPa. The heat pipe inclination angle is set to 5-10°, and gravity is used to assist the working fluid reflux to reduce pumping energy consumption. This channel design can achieve an average daily heat transfer density of not less than 15kW / m 2 Stable heat transfer.

[0022] The collector efficiency is modeled by the following dynamic equation: Where η collector is the instantaneous heat collection efficiency, η0 is the initial efficiency coefficient, k is the heat loss coefficient, T in is the working fluid inlet temperature, T amb is the ambient temperature, G is the solar irradiance. The model dynamically adjusts the collector working state by real-time monitoring of the above parameters. collector When the temperature drops below the set threshold, the phase change material is triggered to release heat forcibly.

[0023] The heat storage process of phase change materials is described by the unsteady heat transfer model: Where ρ is the material density, c p is the specific heat capacity, λ is the thermal conductivity, is the latent heat release rate of phase change. The model uses the finite volume method to solve the phase change interface movement law, predict the temperature distribution of the heat storage body, and guide the heat transfer timing between the collector and the heat storage device.

[0024] Control strategy establishes a multi-objective optimization model: Where Q stored is the actual heat storage, Q target is the preset heat storage target value, T loss is the heat loss temperature, and ω1 and ω2 are weight coefficients. The optimization algorithm outputs the optimal heat storage rate and heat pipe working fluid flow rate to ensure that the phase change material completes more than 80% of the latent heat storage during the peak daytime radiation period.

[0025] The heat pipe's operating state is regulated by a fuzzy PID controller. The input variables include the phase change material temperature deviation e(t) and its rate of change ec(t), and the output variable is the heat pipe's tilt angle adjustment Δθ. The membership function uses a Gaussian distribution, and the control rule base contains 35 empirical rules. This controller can adaptively compensate for heat transfer instabilities caused by solar radiation fluctuations.

[0026] The overheat protection mechanism uses two temperature thresholds: when the phase change material temperature exceeds 65°C, the auxiliary cooling fan activates for forced convection cooling; when the temperature exceeds 70°C, some heat pipe circuits are switched to emergency cooling mode. The protection system and the main control unit utilize a hardware interlock design to ensure that protection is still triggered even if the control system fails.

[0027] Through the synergy of a composite thermal storage structure and intelligent control algorithms, the subsystem achieves stable operation with an average daily solar energy capture efficiency of at least 55%. The latent heat storage properties of the phase change material significantly extend the effective heating period, and the vacuum tube structure maintains a thermal collection efficiency of over 30% even under low irradiance conditions. This implementation ensures high-density, low-loss solar energy input for interseasonal heat storage.

[0028] The ground source heat pump subsystem includes a group of buried pipe heat exchangers arranged in zones; The present invention discloses a specific implementation method of a group of buried pipe heat exchangers arranged in zones in a ground source heat pump subsystem. The subsystem achieves dynamic balance of the soil thermal field through differentiated structural design and intelligent load distribution. The specific technical solution includes the following contents: the buried pipe group is divided into a core heat exchange zone and a buffer temperature control zone. The core zone adopts double U-shaped high-density polyethylene pipes for vertical burial, the pipe diameter is preferably 32-40mm, and the burial depth is controlled at 100-150m. The spacing of the zone is 4-5 times the pipe diameter, and the basic load bearing capacity is improved by increasing the length of the heat exchange pipe per unit area. The buffer temperature control zone adopts a single U-shaped pipe for inclined burial, the inclination angle is preferably 30-60°, the burial depth is reduced to 60-80m, and the pipe diameter is reduced to 20-25mm. This design forms an asymmetric heat exchange structure, which spatially separates the steady-state load and dynamic temperature control functions.

[0029] The load distribution between the two areas is realized through the dynamic adjustment equation: where Q core Indicates the heat exchange capacity of the core area, Q adjust is the heat exchange capacity of the buffer zone, and the adjustment coefficient α(t) is adjusted according to the soil temperature gradient ΔT soil and ambient temperature T amb Dynamic calculation: This equation monitors the ground temperature distribution parameters in real time and dynamically adjusts the load ratio between the two areas to prevent local heat accumulation.

[0030] The thermal response characteristics are characterized by an improved line heat source model: Where T(r,t) is the soil temperature at time t at a distance r from the buried pipe, T0 is the initial ground temperature, q is the heat flux per unit pipe length, λ is the soil thermal conductivity, α is the thermal diffusivity, and Ei is the exponential integral function. This model is used to predict the evolution of the temperature field under different operating modes and guide the optimization of the buried pipe group layout.

[0031] The load distribution coefficient α(t) is solved by a multi-objective genetic algorithm with constraints, and the objective function is defined as: Where T set is the set point for soil temperature, and γ is the weight coefficient for the adjustment rate. The algorithm first generates an initial population, with each individual representing a time series of α(t). It then calculates fitness values ​​and performs selection, crossover, and mutation operations. Finally, it outputs a Pareto optimal solution set and selects the solution with the highest overall score as the control parameter.

[0032] An isolation zone is placed between the core heat exchange area and the buffer temperature control area, with a width preferably 1.5-2.0 times the pipe burial depth. The isolation zone is filled with a low-thermal-conductivity material, such as a mixture of bentonite and quartz sand, with a thermal conductivity controlled at 0.8-1.2 W / (m·K). This design effectively blocks radial thermal interference between the two areas, ensuring independent load distribution.

[0033] The circulating fluid flow rate is controlled using a fuzzy PID algorithm. The input variables are the ground temperature deviation e(t) and its rate of change ec(t), and the output variable is the variable frequency pump speed n(t). A triangular distribution is used as the membership function, and the control rule base contains 21 empirical rules. This controller can adaptively compensate for sudden changes in heat load caused by solar radiation fluctuations, maintaining ground temperature stability.

[0034] The frost protection mechanism features dual control thresholds: when the soil temperature falls below 3°C, the ethylene glycol solution concentration is automatically increased to 40-50%. When the temperature falls below 0°C, the electric heating system is activated and the circulation flow rate is reduced to 30-50% of the rated value. This protection command directly drives the actuator through a hardwired circuit, ensuring fail-safe isolation from the main control system.

[0035] This implementation method achieves long-term stability in the soil thermal field through the synergy of differentiated regional design and dynamic load distribution. The core heat exchange area bears the base load, reducing operating energy consumption, while the buffer temperature control area dynamically adjusts to eliminate heat accumulation. Thermal isolation between the two areas prevents mutual interference in the temperature fields and improves overall system reliability.

[0036] The inter-seasonal heat storage device is used to store and release solar heat and is thermally coupled with the ground pipe heat exchanger group.

[0037] This invention discloses a specific embodiment of a cross-seasonal heat storage device that achieves long-term storage and on-demand release of solar energy through a layered heat storage structure and intelligent coupling control. The specific technical solution includes the following: The heat storage device is an underground cylindrical concrete structure with an inner wall covered with an aerogel insulation layer, preferably 50-80mm thick and with a thermal conductivity of no more than 0.02W / (m·K). The interior is vertically divided into three heat storage zones: a high-temperature zone, a medium-temperature zone, and a low-temperature zone. Basalt fiber partitions, preferably with a porosity of 35-40%, are placed between the layers. This layered structure is designed according to the second law of thermodynamics. The high-temperature zone is placed at the top to enhance heat retention through natural convection, while the low-temperature zone is located near the buried pipe group to facilitate heat exchange.

[0038] The heat storage device is coupled to the solar thermal collection subsystem via a gravity-assisted heat pipe. The rising section utilizes vacuum-insulated copper tubes with an inner diameter of preferably 20-25mm, and the working fluid charge is 25-30% of the tube volume. The condensing section is embedded in the high-temperature layer of the heat storage device and features a honeycomb aluminum fin array with an optimal 3-5mm spacing, effectively expanding the heat exchange area to 8-10 times the base value. This design enables an average daily heat transfer density of 18-22kW / m². 2 , while reducing pumping energy consumption.

[0039] Thermal stratification maintenance strategy establishes a dynamic heat balance equation: Where T i is the temperature of the i-th layer, λ i is the thermal conductivity of the material in the layer, H i is the layer height, q in,i ,q out,i are the heat fluxes entering and leaving the layer, respectively. This partial differential equation is solved by the finite difference method to predict the temperature evolution trend of each layer and guide the decision of heat storage and access priority.

[0040] The heat storage state assessment model adopts the equivalent heat capacity method: where m i is the mass of heat storage medium in each layer, c p,i is the sensible heat capacity, L i is the latent heat material phase change enthalpy, δ i The model calculates the current heat storage capacity through real-time temperature monitoring data, providing a quantitative basis for heat supplement control.

[0041] The hierarchical control algorithm is based on a fuzzy decision-making mechanism, and the input variables include the temperature deviation ΔT of each layer i , solar irradiance G and buried pipe heat demand Q geo First, a three-layer membership function is established. The temperature deviation of the high-temperature layer adopts the S-type function, and the medium and low-temperature layers adopt the triangular function. Then, the weighted average method is applied to calculate the heat distribution coefficient: Finally, the priority and ratio of heat extraction from each layer are determined, with heat from the high-temperature layer being extracted first to meet immediate needs, and heat from the medium and low-temperature layers being used for geothermal field balance regulation.

[0042] The safety protection system sets a temperature gradient threshold. When the temperature difference between adjacent layers exceeds 15°C, a forced circulation pump is activated, promoting heat exchange between layers through a built-in coil system. Pressure protection utilizes dual redundant safety valves, which automatically release pressure when the internal pressure of the thermal storage device exceeds 0.8 MPa. The pressure relief rate is controlled at 0.1-0.2 MPa / s. This mechanism prevents the risk of overpressure caused by vaporization of the phase change material.

[0043] The implementation method, through the synergy of a tiered heat storage structure and a dynamic control model, achieves stable operation with a heat storage density of at least 300 MJ / m³ across all seasons. The high-temperature layer's preferential heat extraction strategy improves winter heating efficiency by 20-30%. The buffering and temperature regulation function of the medium and low-temperature layers effectively mitigates thermal imbalances in the underground pipe system. The combined design of the device and its control algorithm ensures a heat retention period of up to six months.

[0044] Example 2: A balance control method comprising the following steps: S1. Decision-making on inter-seasonal heat supplementation based on soil thermal balance; The present invention discloses a specific implementation method for determining interseasonal heat supplementation based on soil thermal equilibrium in a balance control method. This step achieves accurate heat supplementation decisions by establishing a dynamic heat balance model and a prediction algorithm. The specific technical solution includes the following: Heat supplementation decisions first establish a soil heat balance equation, whose mathematical expression is: Q storage =αA solar G-β(T soil -T amb )-Q heatpump ; Where Q storage is the required heat, α is the solar energy conversion coefficient, A solar is the effective heat collection area, G is the real-time solar irradiance, β is the soil heat loss coefficient, T soil is the average temperature of the ground temperature field, T amb is the ambient temperature, Q heatpump The cumulative heat value of the heat pump is taken as the historical value. This equation is constructed based on the principle of energy conservation and comprehensively considers the dynamic balance between solar energy input, soil heat dissipation, and heat pump consumption.

[0045] The parameter acquisition process includes: measuring T soil Sampling points are arranged in an equilateral triangle grid, preferably with spacing of 3-5 meters. G values ​​are collected in real time by a secondary standard radiometer mounted on the collector surface, with a data sampling frequency of 10-60 seconds. The α coefficient is obtained by calibrating the collector efficiency curve and is regularly calibrated using a standard blackbody radiation source, preferably every six months.

[0046] The prediction algorithm uses a long short-term memory neural network (LSTM), and the input parameters include a 72-hour historical meteorological data sequence (G, T amb ,V wind ) and ground temperature change rate dT soilThe network structure consists of 3 hidden layers, with the number of neurons in each layer preferably being 128-256, and the activation function being ReLU. The output is the calorie requirement for the next 24 hours. The time resolution is 1 hour. The training dataset must contain at least 3 full years of operating data, and the loss function is defined as: Where W is the network weight and λ is the regularization coefficient, which is preferably 0.001-0.01.

[0047] The decision correction module dynamically adjusts the predicted value based on real-time monitoring data. The correction factor is calculated as follows: When γ exceeds the threshold, the weighted average algorithm based on the sliding time window is started: The weight coefficient w(t) is allocated according to the exponential decay law, and the time constant is preferably 2-4 hours. This correction mechanism can suppress the error accumulation of the prediction model under extreme weather conditions. After the heat supplement control instruction is generated, it is transmitted to the heat storage device circulation pump group via the Modbus protocol. The flow setting value is based on According to the inverse calculation of the heat transfer equation: where c p is the specific heat capacity of the circulating working fluid, ΔT design To design the heat transfer temperature difference, it is preferably 8-12°C. The calculation process takes into account the compensation for pipeline heat loss, and the compensation coefficient is dynamically updated based on the measured value of the heat flow meter.

[0048] By integrating physical models with data-driven algorithms, this implementation method achieves a heating supply decision error rate of less than 5%. The LSTM prediction model effectively captures the nonlinear relationship between meteorological parameters and ground temperature fields, and the correction module enhances the system's robustness under sudden operating conditions. Closed-loop control of decision-making results and actuators ensures that the annual cumulative deviation between heating supply and heat withdrawal is controlled within 3%.

[0049] S2. Switch heating and cooling modes according to seasonal conditions; This invention discloses a specific implementation method for switching heating and cooling modes according to seasonal operating conditions in a balancing control method. This step achieves intelligent switching of operating modes by establishing a multi-parameter coupling decision model. The specific technical solution includes the following: The seasonal operating mode switching decision is based on the fusion analysis of the temperature stratification data of the heat storage device and the meteorological forecast model, and the mode switching function is established: M mode =f(T storage ,COP pred ,ΔTsoil ); Where T storage is the high temperature layer temperature of the heat storage device, COP pred To predict the energy efficiency ratio, ΔT soil is the ground temperature gradient. storage ≥60℃ and COP pred >2.8, switch to direct heat pump mode; when T storage <35℃ or ΔT soil When the temperature is >8°C, the system switches to underground pipe heating mode. This function is determined by thermodynamic feasibility analysis and historical data regression.

[0050] The fuzzy decision model construction includes three input variables: the temperature change rate of the heat storage device dT storage / dt, average ambient temperature for the next 24 hours Building load demand Q load . First, establish the triangle membership function: The membership function for the winter heating mode is trapezoidal, with turning points set at 25°C and 30°C. The rule base contains 32 IF-THEN fuzzy rules. Belong to "high temperature" and Q load During "High Demand" periods, the cooling mode priority is activated.

[0051] The mode switching execution process adopts a two-stage verification mechanism: first, a preliminary instruction is generated based on the prediction model, and then the execution conditions are verified through real-time monitoring data. The verification parameters include the temperature difference ΔT at the inlet and outlet of the buried pipe. pipe and circulating fluid flow Need to meet: |ΔT pipe -ΔT set |≤2℃; The flow rate fluctuation rate does not exceed ±10%. If the calibration fails, the model parameters are triggered to identify online and the heat transfer coefficient K is updated. pipe Then recalculate the switching conditions.

[0052] The transition season forecast model establishes the ARIMA time series equation: Where B is the hysteresis operator, d is the differencing order, and ∈(t) is a white noise sequence. The model uses the minimum information criterion (AIC) to determine the optimal order combination (p, d, q) and predict the temperature trend over the next seven days. A pre-mode switch is triggered when the absolute value of the trend slope exceeds 0.5°C / day.

[0053] Mode switching control instructions are transmitted to the multi-condition valve group via Profibus-DP protocol, and the valve opening V open Adjust according to the following ratio: V open =K p ·(T set -T actual )+K i ∫(T set -T actual )dt; where K p , K i The valve position feedback signal and the DCS system form a closed-loop control, and the positioning accuracy reaches ±0.5%.

[0054] The exception handling mechanism sets double interlock: when T occurs during mode switching storage If the mutation rate exceeds 3°C / min or the pressure fluctuation exceeds 0.2 MPa / s, the actuator is immediately frozen and switched to safe mode. Fault codes are uploaded to the central monitoring system via the OPC-UA protocol, triggering audible and visual alarms and logging.

[0055] This implementation utilizes multi-source information fusion and a dual verification mechanism to complete mode switching within 30 seconds while maintaining temperature fluctuations within ±1.5°C. A fuzzy decision-making model effectively accounts for the strong coupling between meteorological and thermal parameters. The lead time of time series prediction reduces system preparation time by over 40%. The mode switching process, along with heating supplementation decision-making (S1) and load distribution (S3), forms a closed-loop control chain, ensuring year-round system operational stability.

[0056] S3. Dynamically adjust the load distribution ratio of the buried pipe heat exchange zone; This invention discloses a specific implementation method for dynamically adjusting the load distribution ratio of the buried pipe heat exchange zone within a balanced control method. This step achieves precise heat load distribution by establishing a multi-objective optimization model and an intelligent control algorithm. The specific technical solution includes the following: Load distribution ratio adjustment is based on a coupled modeling of the dynamic heat balance equation and heat transfer characteristics. The heat flow distribution relationship between the core zone and the buffer zone is defined as: Where Q core is the load of the core heat exchange area, Q adjust To buffer the load of the temperature adjustment area, the adjustment coefficient α(t) is adjusted according to the real-time ground temperature gradient The equation is constructed by the law of conservation of energy to ensure that the total load distribution complies with the system heat capacity constraint.

[0057] The multi-objective optimization model takes geothermal field stability and system energy efficiency as optimization objectives, and the objective function is defined as: Where T core is the average ground temperature in the core area, COP sys is the real-time energy efficiency ratio of the system, and the weight coefficients ω1 and ω2 are determined by the hierarchical analysis method.

[0058] Constraints include: core area temperature rise rate Buffer maximum load ratio Q adjust / Q total ≤70%.

[0059] The solution algorithm uses the non-dominated sorting genetic algorithm (NSGA-II) with an elitist strategy. The initial population size is preferably 100-200 individuals, with each individual encoded as a 24-hour time series of α(t). The crossover operator is simulated binary crossover (SBX), with a distribution index of 20-30. The mutation probability is preferably 0.01-0.05 to ensure a balance between algorithm convergence and diversity. After 50-100 iterations, the solution with the highest overall score on the Pareto front is selected as the control parameter.

[0060] The fuzzy PID controller adjusts the frequency of the circulating pump in real time, and the input variable is the ground temperature deviation e(t) = T set -T core The output variable is the pump speed increment Δf. The membership function uses a Gaussian distribution, and the core temperature deviation domain is divided into five levels: [NB, NS, ZO, PS, PB]. The control rule library contains 35 empirical rules. For example, when e(t) is "positive and large" and ec(t) is "negative and small", the output Δf is "positive and large".

[0061] The thermal resistance effect of the isolation zone is characterized by the equivalent thermal circuit model: R total =R soil +R fill +R pipe ; Where R soil is the original soil thermal resistance, R fill is the thermal resistance of the filling material, R pipe The thermal resistance of the pipe wall is the contact resistance. The preferred filler material is a mixture of bentonite and perlite, with a mass ratio of 3:1, and a thermal conductivity of 0.8-1.2 W / (m·k). This design increases the thermal resistance of the isolation zone to 2-3 times that of the adjacent area, effectively preventing thermal short-circuiting.

[0062] The safety protection mechanism sets two levels of control thresholds: local temperature gradient When the temperature rise rate in the core area exceeds 0.8°C / h, the emergency cooling mode is triggered. The protection command directly controls the opening of the electric valve through a hard-wired circuit, with a response time of less than 500ms.

[0063] The implementation method achieves a load distribution ratio adjustment error rate of less than 3% through the synergistic effect of dynamic optimization and real-time control. A multi-objective optimization algorithm balances ground temperature field stability with system energy efficiency, and a fuzzy PID controller effectively suppresses fluctuations caused by external disturbances. The isolation zone design ensures thermal decoupling between the core and buffer zones, reducing annual ground temperature fluctuations by over 40%.

[0064] S4. Implement temperature-stratified heat storage and priority extraction strategies.

[0065] This invention discloses a specific implementation method for implementing a temperature-stratified heat storage and priority extraction strategy within a balanced control method. This step achieves efficient utilization of the heat storage device by establishing a stratified thermal model and an intelligent extraction algorithm. The specific technical solution includes the following: The heat storage device is vertically divided into three heat storage zones: a high-temperature layer, an intermediate-temperature layer, and a low-temperature layer. The high-temperature layer is equipped with a honeycomb aluminum fin structure to enhance heat exchange, with fin heights preferably 15-25mm and spacings 3-5mm. The intermediate-temperature layer is filled with porous basalt heat storage balls, preferably 30-50mm in diameter and with a porosity of 35-45%. This increases the contact area and improves heat storage density. The low-temperature layer is equipped with spiral coils connected to the buried pipe group, with a pitch of 8-10 times the pipe diameter to ensure uniform distribution of the working fluid flow rate.

[0066] The layered heat balance equation describes the heat transfer relationship between each layer: Where ρ i is the layer density, c p,i is the specific heat capacity, λ i is the thermal conductivity, is the inlet and outlet heat flux density. This equation is solved discretely by the finite element method, with a time step of preferably 60-300 seconds, and the three-dimensional distribution data of the temperature field of each layer is output.

[0067] The priority extraction strategy establishes a fuzzy decision tree model, and the input variables include the temperature T of each layer i , Heat demand of buried pipe Q geo , solar irradiance G. The membership function adopts trapezoidal distribution, the temperature domain of the high temperature layer is divided into [50℃, 80℃], and the temperature domain of the middle temperature layer is [30℃, 60℃]. The rule base contains 45 decision rules. For example, when T high ≥65℃ and Q geo >0.8Q max When , the high temperature layer direct supply mode is activated.

[0068] The extraction control algorithm adopts a dynamic weight allocation mechanism, and the priority coefficient calculation formula is: Where γ is the temperature sensitivity factor, preferably 0.05-0.15. This function ensures that the high-temperature layer receives 65-80% of the heat weight under heating conditions, and the medium and low-temperature layers are increased to 30-50% during temperature adjustment in the transition season.

[0069] Interlayer thermal short circuits are suppressed by installing basalt fiber separators, preferably 80-120mm thick and with a thermal conductivity no higher than 0.5W / (m·K). The separators are surface-corrugated with peaks 3-5mm high, effectively extending the radial heat conduction path. This design reduces interlayer heat flux to 20-30% of that in an uninsulated state.

[0070] The safety protection mechanism sets a temperature gradient threshold. When the temperature difference between adjacent layers exceeds 20°C, the emergency temperature equalization circulation pump is activated and the flow rate is adjusted according to the following equation: where K p , K i The proportional integral coefficient is calibrated through step response testing. The circulating fluid is preferably a 40% ethylene glycol solution to prevent freezing in low temperature conditions.

[0071] The implementation method achieves an average daily heat extraction efficiency of at least 75% through the synergy of tiered storage and intelligent extraction. A fuzzy decision tree model effectively balances immediate demand with long-term energy storage. Dynamic weight allocation increases the utilization rate of the high-temperature layer's heat storage to over 90%. The interlayer isolation structure limits unintended heat loss to less than 5% of the total stored heat.

[0072] Embodiment 3: A coupling device, comprising: a first heat pipe loop connecting the solar heat collection subsystem and the heat storage device; A second heat pipe loop connecting the heat storage device and the buried heat exchanger group; Multi-condition switching valve group is used to select the flow direction of the heat source.

[0073] The switching conditions of the multi-condition switching valve group include: When the temperature of the high temperature layer of the heat storage device is ≥60°C, the first heat pipe loop is started to directly pass through the heat pump evaporator; When the temperature of the mesolayer of the heat storage device is ≥40°C, the second heat pipe loop is started in parallel to supplement heat.

[0074] The examples of this specific embodiment are all preferred embodiments of this application and are not intended to limit the scope of protection of this application. Identical components are represented by the same reference numerals. Therefore, any equivalent changes made based on the structure, shape, and principle of this application should be included in the scope of protection of this application.

Claims

1. A solar energy inter-seasonal heat storage and release ground source heat pump system, characterized by: include: A solar thermal collection subsystem for collecting and storing solar heat; The ground source heat pump subsystem includes a group of buried pipe heat exchangers arranged in zones; The inter-seasonal heat storage device is used to store and release solar heat and is thermally coupled with the ground pipe heat exchanger group.

2. The solar energy inter-seasonal heat storage and release geothermal heat pump system according to claim 1 is characterized in that: The buried heat exchanger group of the ground source heat pump subsystem is divided into a core heat exchange area and a buffer temperature adjustment area, and its load distribution ratio satisfies the following dynamic adjustment equation: in: Q core (t): load of the core heat exchange area at time t; Q adjust (t): load of the buffer temperature control zone at time t; Q total (t): total load demand of the system at time t; α(t): Dynamic adjustment coefficient of the core area, based on the real-time monitored soil temperature T soil (t) and ambient temperature T ambient (t) calculation; β(t): Dynamic adjustment coefficient of the temperature control zone, satisfying β(t) = 1-α(t).

3. The solar energy inter-seasonal heat storage and release geothermal heat pump system according to claim 1 is characterized in that: The inter-seasonal heat storage device is an underground concrete structure, and is provided with three temperature gradient zones: a high temperature layer, a medium temperature layer and a low temperature layer.

4. The solar energy inter-seasonal heat storage and release geothermal heat pump system according to claim 1 is characterized in that: The solar heat collection subsystem includes a vacuum tube-phase change heat storage integrated collector, and its heat storage density is not less than 180MJ / m 3 .

5. A balance control method, applied to the solar inter-seasonal heat storage and release geothermal heat pump system according to any one of claims 1 to 4, characterized in that: The following steps are involved: Decision-making on inter-seasonal heat supplementation based on soil heat balance; Switch heating and cooling modes according to seasonal conditions; Dynamically adjust the load distribution ratio of the buried pipe heat exchange area; Implement temperature-stratified heat storage and priority extraction strategies.

6. The balance control method according to claim 5, characterized in that: The cross-seasonal heat supplementation decision is calculated by the following soil heat balance equation: Q storage =α·A solar ·G-β·(T soil -T ambient )-Q heatpump ; in: α is the solar energy conversion coefficient, A solar is the effective area of ​​the collector, G is the solar irradiance, β is the soil heat dissipation coefficient, T soil is the soil temperature, T ambient is the ambient temperature, Q heatpump Take heat for the heat pump.

7. The balance control method according to claim 5, characterized in that: The dynamic adjustment process is achieved through a multi-objective optimization model, and the objective function is: in: Q solar To supplement the heat of solar energy, Q geo Heat for ground source heat pump, COP sys is the system real-time energy efficiency ratio, COP target is the preset energy efficiency target value; ω1, ω2 are weight coefficients.

8. The balance control method according to claim 5, characterized in that: The seasonal operating condition switching includes: When the temperature of the high-temperature layer of the heat storage device is ≥60°C, it switches to the direct heat pump mode; When the temperature of the heat storage device is less than 35℃, it switches to the buried pipe heating mode.

9. A coupling device for realizing heat exchange of the solar inter-seasonal heat storage and release geothermal heat pump system according to claims 1-4, characterized in that: include: a first heat pipe loop connecting the solar heat collection subsystem and the heat storage device; A second heat pipe loop connecting the heat storage device and the buried heat exchanger group; Multi-condition switching valve group is used to select the flow direction of the heat source.

10. The coupling device according to claim 9, characterized in that The switching conditions of the multi-mode switching valve group include: when the temperature of the high-temperature layer of the heat storage device is ≥60°C, starting the first heat pipe loop directly connected to the heat pump evaporator; When the temperature of the mesolayer of the heat storage device is ≥40°C, the second heat pipe loop is started in parallel to supplement heat.

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