Air energy-soil composite heat pump cross-seasonal energy storage and winter combined heating system and application method

Abstract

The invention discloses an air energy-soil composite heat pump cross-seasonal energy storage and winter combined heating system and an application method, and relates to the technical field of building energy conservation. Comprising the following steps: acquiring quantitative data of heat unbalance; when a heat unbalance phenomenon exists, determining a soil initial temperature and a maximum rising temperature before heat compensation, and calculating a heat compensation amount; determining a heat compensation operation time period and a system type selection of an air source heat pump; determining an initial rising temperature, a heat compensation initial investment and a preset age limit; the operation cost is determined, when the number of times of heat compensation is larger than a preset year limit, the sum of the initial investment of heat compensation and the operation cost within the preset year limit is recorded, and when it is detected that the total soil temperature increasing value is not lower than the maximum temperature increasing value, the air source heat pump system is determined again; and the strategy with the minimum operation cost and the minimum initial heat compensation investment is used as the optimal soil heat compensation strategy. The system obviously improves the utilization rate of renewable energy sources, and has the advantages of high energy efficiency, wide adaptability and low whole life cycle cost.

Description

Technical Field

[0001] This invention relates to the field of building energy conservation technology, and in particular to an air-source-soil composite heat pump system for cross-seasonal energy storage and winter combined heating, and its application method. Background Technology

[0002] With the increasing prominence of the global energy crisis and environmental problems, efficient and environmentally friendly heating systems have become a research hotspot in the field of building energy conservation. Traditional ground source heat pump systems generally suffer from soil thermal imbalance during long-term operation, especially in cold regions, where the accumulated heat taken in winter is significantly higher than the heat released in summer, leading to a gradual decrease in soil temperature and severe degradation of system energy efficiency. Existing technologies mostly employ methods such as single heat supplementation or expansion of underground heat exchangers, but these suffer from drawbacks such as low heat supplementation efficiency, poor economics, or large footprint. Meanwhile, although air source heat pumps have flexible heat supplementation potential, existing solutions lack deep coupling with ground source systems and cross-seasonal energy storage synergy mechanisms, making it difficult to achieve precise control of soil thermal balance and efficient energy utilization.

[0003] Therefore, how to provide a method for the application of an air-source-soil composite heat pump system for cross-seasonal energy storage and winter combined heating to overcome the difficulties of existing technologies is a problem that urgently needs to be solved by those skilled in the art. Summary of the Invention

[0004] In view of this, the present invention provides an application method for an air-source-soil composite heat pump cross-seasonal energy storage and winter combined heating system, which significantly improves the utilization rate of renewable energy and has the advantages of high energy efficiency, wide adaptability and low life cycle cost.

[0005] To achieve the above objectives, the present invention adopts the following technical solution:

[0006] An air-source heat pump-soil composite heat pump system for seasonal energy storage and winter heating includes an air-source heat pump unit, a ground-source heat pump unit, a buried pipe heat exchanger, and heating terminals.

[0007] The heating terminal, ground source heat pump unit and buried pipe heat exchanger are connected in series, and air source heat pump unit and ground source heat pump unit are connected in parallel.

[0008] A method for applying an air-source-soil composite heat pump system for interseasonal energy storage and combined winter heating, applicable to any of the aforementioned air-source-soil composite heat pump systems for interseasonal energy storage and combined winter heating, includes the following steps:

[0009] S1. Obtain thermal imbalance quantitative data to determine whether there is thermal imbalance in the target building's ground source heat pump system under heating and cooling operation conditions. If so, determine the initial temperature, maximum rise temperature, initial rise temperature, and rise step of the soil before heat replenishment in the target area. Based on the soil volume, initial temperature, target temperature, and specific heat capacity of the soil in the target area, determine the soil heat demand. Based on the building load data, determine the operating time period and preset number of years for summer air source heat pump heat replenishment.

[0010] S2. Based on the soil heat demand and the operating time of the air source heat pump for summer heat replenishment, calculate the average daily heat replenishment of the soil in summer, determine the heating capacity of the air source heat pump based on the average daily heat replenishment, and then determine the selection of the air source heat pump system, obtain the summer heat replenishment operation strategy, and determine the initial investment of the heat replenishment system.

[0011] S3. Based on the performance parameters of the air source heat pump unit and the outdoor temperature, obtain the curve and fitting formula of the air source heat pump unit heating capacity correction coefficient and the outdoor ambient temperature, and the curve and fitting formula of the input power correction coefficient and the outdoor ambient temperature to obtain the summer heat supplementation and winter heating operation strategies.

[0012] S4. Based on the summer heat supplementation operation strategy of air source heat pump and the joint operation strategy of air source heat pump and ground source heat pump for winter heating, obtain the operating costs of summer heat supplementation and winter heating, set the number of heat supplementation times, and set the initial value to 0.

[0013] S5. Determine whether the number of reheating cycles is less than or equal to the preset number of years. If yes, increment the number of reheating cycles by 1 and continue running. If no, record the sum of the initial investment in reheating and the operating costs of summer reheating and winter combined heating within the preset number of years, and determine whether the improved soil temperature exceeds the maximum value of soil temperature improvement.

[0014] S6. If not, take the increased soil temperature as the initial increased temperature of the target area, increment the cycle number by 1, redetermine the air source heat pump system, and repeat steps S2-S5; output multiple soil heating strategies, and take the strategy with the lowest operating cost and initial investment in heating as the optimal soil heating strategy.

[0015] Optionally, thermal imbalance quantification data includes building load data and cumulative heat input and output data of the ground source heat pump system. The assessment of thermal imbalance is based on the cumulative heat output Q of the ground source heat pump system. c And cumulative heat Q h get:

[0016] The ratio of cumulative heat taken out to cumulative heat released is defined as a comprehensive index. The expression is as follows:

[0017]

[0018] when When the cumulative heat taken out by the ground source heat pump system exceeds the cumulative heat released, a thermal imbalance occurs; when When the cumulative heat output of the ground source heat pump system is greater than or equal to the cumulative heat output, there is no thermal imbalance.

[0019] Optionally, the supplementary heat is determined based on the soil heat demand, expressed as:

[0020]

[0021] Among them, Q k The heat required by the soil in the k-th cycle is expressed in kWh, ΔT. k This represents the increase in soil temperature during the k-th cycle.

[0022] Optionally, the heating capacity of the air source heat pump is determined including:

[0023]

[0024] Among them, Q 空 ξ is the heating power of the air source heat pump; D is the number of days the air source heat pump provides supplemental heating; t is the average daily supplemental heating hours; ξ is a correction factor used to reflect the efficiency of the air source heat pump as the outdoor temperature changes.

[0025] Optionally, the expression for the correction factor ξ under different outdoor temperatures is:

[0026]

[0027] Wherein, the heating capacity ξ(T) is the actual heating capacity of the air source heat pump at ambient temperature T; the rated heating capacity is the heating capacity of the air source heat pump under rated operating conditions.

[0028] Optionally, factors that determine the performance parameters of an air source heat pump unit include heating capacity, energy efficiency ratio, noise level, investment cost, and ease of maintenance.

[0029] Optionally, the expression for adjusting the soil temperature rise value is as follows:

[0030] t k =C1+(k-1)△T s ,

[0031] Among them, t k ΔT represents the soil temperature rise, k represents the number of cycles, and ΔT is the soil temperature rise value. s To change the step size of soil temperature increase, C1 is the initial value of the soil temperature increase, and the corresponding expression is:

[0032]

[0033] Where △Q is the difference between the annual heat load and cooling load of the target building before supplemental heating, and C p ·ρ·ν represents the soil heat capacity.

[0034] As can be seen from the above technical solution, compared with the prior art, the present invention provides an air-source-soil composite heat pump cross-seasonal energy storage and winter combined heating system and application method, which has the following beneficial effects: 1) The present invention establishes a soil temperature variation amplitude prediction algorithm and an economic evaluation model to achieve dynamic balance of soil temperature field and optimal operating cost; 2) The present invention effectively solves the performance degradation problem caused by thermal imbalance of traditional systems, significantly improves the utilization rate of renewable energy, and has the advantages of high energy efficiency, wide adaptability and low life cycle cost. Attached Figure Description

[0035] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0036] Figure 1 This is a schematic diagram of an air-source-soil composite heat pump system for cross-seasonal energy storage and combined winter heating, as disclosed in this invention.

[0037] Figure 2 This is a flowchart of an application method for an air-source-soil composite heat pump cross-seasonal energy storage and winter combined heating system disclosed in this invention;

[0038] Figure 3 This is a schematic diagram of the application method of an air-source-soil composite heat pump cross-seasonal energy storage and winter combined heating system disclosed in this invention;

[0039] Among them, 1 is the buried pipe heat exchanger, 2 is the air source heat pump unit, 3 is the ground source heat pump unit, and 4 is the heating terminal. Detailed Implementation

[0040] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0041] Reference Figure 1As shown, the present invention discloses an air source heat pump-soil composite heat pump cross-seasonal energy storage and winter combined heating system, including an air source heat pump unit 2, a ground source heat pump unit 3, a buried pipe heat exchanger 1, and a heating terminal 4.

[0042] Heating terminal 4, ground source heat pump unit 3 and buried pipe heat exchanger are connected in series, and air source heat pump unit 2 and ground source heat pump unit 3 are connected in parallel.

[0043] Specifically, during the non-heating season (summer), the air source heat pump absorbs heat from the air and then transports the heat to the underground pipe heat exchanger via a circulating water pump, storing the heat in the underground soil to achieve cross-seasonal energy storage. During the heating season (winter), the air source heat pump and the ground source heat pump operate in combination, extracting heat from the air and soil respectively, and achieving coordinated heating through a multi-path switching device to provide stable heating to end users.

[0044] A method for applying an air-source-soil composite heat pump system for interseasonal energy storage and combined winter heating, applicable to any of the aforementioned air-source-soil composite heat pump systems for interseasonal energy storage and combined winter heating, with reference to... Figure 2 and Figure 3 As shown, it includes the following steps:

[0045] S1. Obtain thermal imbalance quantitative data to determine whether there is thermal imbalance in the target building's ground source heat pump system under heating and cooling operation conditions. If so, determine the initial temperature, maximum rise temperature, initial rise temperature, and rise step of the soil before heat replenishment in the target area. Based on the soil volume, initial temperature, target temperature, and specific heat capacity of the soil in the target area, determine the soil heat demand. Based on the building load data, determine the operating time period and preset number of years for summer air source heat pump heat replenishment.

[0046] S2. Based on the soil heat demand and the operating time of the air source heat pump for summer heat replenishment, calculate the average daily heat replenishment of the soil in summer, determine the heating capacity of the air source heat pump based on the average daily heat replenishment, and then determine the selection of the air source heat pump system, obtain the summer heat replenishment operation strategy, and determine the initial investment of the heat replenishment system.

[0047] S3. Based on the performance parameters of the air source heat pump unit and the outdoor temperature, obtain the curve and fitting formula of the air source heat pump unit heating capacity correction coefficient and the outdoor ambient temperature, and the curve and fitting formula of the input power correction coefficient and the outdoor ambient temperature to obtain the summer heat supplementation and winter heating operation strategies.

[0048] S4. Based on the summer supplementary heating operation strategy of air source heat pump and the joint operation strategy of air source heat pump and ground source heat pump for winter heating, obtain the operating costs of summer supplementary heating and winter heating, set the number of supplementary heating times, and set the initial value to 0 (set the number of supplementary heating times first, and then determine the operating costs).

[0049] S5. Determine whether the number of reheating cycles is less than or equal to the preset number of years. If yes, increment the number of reheating cycles by 1 and continue running. If no, record the sum of the initial investment in reheating and the operating costs of summer reheating and winter combined heating within the preset number of years, and determine whether the improved soil temperature exceeds the maximum value of soil temperature improvement.

[0050] S6. If not, take the increased soil temperature as the initial increased temperature of the target area, increment the cycle number by 1, redetermine the air source heat pump system, and repeat steps S2-S5; output multiple soil heating strategies, and take the strategy with the lowest operating cost and the lowest initial investment in heating as the optimal soil heating strategy.

[0051] Furthermore, the thermal imbalance quantification data includes building load data and cumulative heat input and output data of the ground source heat pump system. The assessment of thermal imbalance is based on the cumulative heat output Q of the ground source heat pump system. c And cumulative heat Q h get:

[0052] The ratio of cumulative heat taken out to cumulative heat released is defined as a comprehensive index. The expression is as follows:

[0053]

[0054] when When the cumulative heat taken out by the ground source heat pump system exceeds the cumulative heat released, a thermal imbalance occurs; when When the cumulative heat output of the ground source heat pump system is greater than or equal to the cumulative heat output, there is no thermal imbalance, and the cumulative heat output Q is... c And cumulative heat Q h All units are in kWh.

[0055] Furthermore, the cumulative heat dissipation Q of the ground source heat pump system c And cumulative heat Q h Calculated based on building load data and heat pump unit performance parameters:

[0056] Based on the meteorological conditions of the target building, the building load data clarifies the heating and cooling time periods, and uses energy consumption simulation software to calculate the hourly heating and cooling loads of the target building under design conditions.

[0057] Cumulative heat dissipation Q c The corresponding expression is:

[0058]

[0059] in, q represents the cumulative cooling load of the system. ciThe system's hourly cooling load is represented by EER, which is the seasonal energy efficiency coefficient of the heat pump unit under cooling conditions, and N is the number of cooling hours.

[0060] Cumulative heat extraction Q h The corresponding expression is:

[0061]

[0062] in, q represents the cumulative cooling load of the system. hi The system's hourly heat load is given by , COP is the seasonal energy efficiency coefficient of the heat pump unit under heating conditions, and n is the number of heating hours.

[0063] Furthermore, over a period of time, changes in soil temperature depend on the relationship between the injected or extracted heat and the soil's heat capacity; the changes in soil heat can be expressed as:

[0064]

[0065] Among them, Q b The soil heat capacity is C, which represents the amount of heat injected or extracted into the soil over a period of time. P ·ρ·V,C ρ Let ρ be the specific heat capacity of the soil, ρ be the soil density, V be the soil volume, and ΔT be the soil temperature change. After simplification, we can obtain:

[0066]

[0067] Specifically, during winter heating,

[0068] Q b =Q c -Q e ,

[0069]

[0070] Where L is the length of the buried pipe, d is the hole spacing, and Q e For the heating capacity of the water pump, P e Δt represents the rated power of the water pump and the time interval.

[0071] Furthermore, the heat supplement is determined based on the soil heat demand, expressed as:

[0072]

[0073] Among them, Q k ΔT is the amount of heat required by the soil in the k-th cycle. k This represents the increase in soil temperature during the k-th cycle.

[0074] Furthermore, the heating capacity of the air source heat pump is determined to include:

[0075]

[0076] Among them, Q 空 ξ is the heating power of the air source heat pump; D is the number of days the air source heat pump provides supplemental heating; t is the average daily supplemental heating hours; ξ is a correction factor used to reflect the efficiency of the air source heat pump as the outdoor temperature changes.

[0077] Furthermore, the correction factor ξ is used to reflect the efficiency change of the air source heat pump under different outdoor ambient temperatures. Typically, the rated operating conditions of an air source heat pump are the performance parameters at a certain standard outdoor temperature (such as 7°C). Each air source heat pump has a set of performance curves showing the heating capacity, energy efficiency ratio (COP), and power consumption at different outdoor temperatures. These curves can be obtained from the equipment's technical manual.

[0078] Furthermore, the expression for the correction factor ξ under different outdoor temperatures is as follows:

[0079]

[0080] Wherein, the heating capacity ξ(T) is the actual heating capacity of the air source heat pump at ambient temperature T; the rated heating capacity is the heating capacity of the air source heat pump under rated operating conditions.

[0081] To account for the impact of outdoor temperature variations during model selection, a correction factor needs to be applied to the rated operating conditions of the air source heat pump to calculate the adjusted heating demand. The specific steps are as follows:

[0082] Obtain correction factors at ambient temperatures: Obtain correction factors for different ambient temperatures from the equipment's performance curves. For example, the correction factors ξ at ambient temperatures of -5℃, 0℃, 5℃, and 10℃ are respectively... -5 ξ0, ξ5, ξ 10 .

[0083] Determine the weighted average correction factor: Based on meteorological data during the summer operating period, determine the frequency of occurrence f(T) of each ambient temperature, and then calculate the weighted average correction factor ξ. avg The corresponding expression is:

[0084]

[0085] The adjusted formula for calculating heating power is:

[0086]

[0087] When selecting a model, the total heating power should not be less than Q. 空 .

[0088] Furthermore, factors that determine the performance parameters of an air source heat pump unit include heating capacity, energy efficiency ratio, noise level, investment cost, and ease of maintenance.

[0089] Specifically, prioritize heat pumps with higher COP to reduce operating costs; a COP ≥ 3.0 is recommended. When the air source heat pump is located in a residential area, a low-noise model should be selected.

[0090] Furthermore, the expression for the soil temperature rise is adjusted as follows:

[0091] t k =C1+(k-1)△T s ,

[0092] Among them, t k ΔT represents the soil temperature rise, k represents the number of cycles, and ΔT is the soil temperature rise value. s To change the step size of soil temperature increase, C1 is the initial value of the soil temperature increase, and the corresponding expression is:

[0093]

[0094] Where △Q is the difference between the annual heat load and cooling load of the target building before supplemental heating, and C p ·ρ·v represents the soil heat capacity.

[0095] In one specific embodiment, with the goal of minimizing operating costs, the heat storage strategy obtained by optimizing equipment operating time and load allocation to ensure cost minimization includes:

[0096] 1. Heat storage strategies during the non-heating season (summer):

[0097] Dynamically controlled operating cycle: After each heating season, the soil is replenished with heat by an air source heat pump to maintain soil thermal balance. By combining the soil heat replenishment design, the start-up and shutdown times of the air source heat pump are dynamically adjusted to ensure sufficient heat storage in the soil.

[0098] 2. Operational strategy for the heating season (winter):

[0099] During the winter heating season, air-source heat pumps and ground-source heat pumps operate in tandem, extracting heat from the air and soil to meet building heating needs. To achieve efficient operation, the following strategies are required:

[0100] Air source heat pump operation strategy: During the early and late stages of winter when ambient temperatures are high, the air source heat pump is prioritized to reduce reliance on the ground source heat pump. When the heating load of the air source heat pump is insufficient to meet the building's heating needs, the ground source heat pump automatically connects for coordinated operation.

[0101] Ground source heat pump operation strategy: During peak heating periods (such as the coldest part of winter), when the soil heat reserve is sufficient, the ground source heat pump operates independently, and the operating frequency is scientifically adjusted in conjunction with a soil thermal imbalance monitoring model to avoid excessive drop in soil temperature. When the total load demand of the building exceeds the heating capacity of the ground source heat pump system, the combined operation mode is activated. The ground source heat pump continues to operate up to its rated maximum load, while the air source heat pump provides additional heat.

[0102] Intelligent energy management: Utilizes intelligent controllers to collect and analyze key system parameters (such as soil temperature, outdoor ambient temperature, load demand, etc.) in real time, and dynamically adjusts the operating mode.

[0103] The above description of the disclosed embodiments enables those skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. An air-source-soil composite heat pump system for cross-seasonal energy storage and combined winter heating, characterized in that, It includes an air source heat pump unit (2), a ground source heat pump unit (3), a buried pipe heat exchanger (1), and a heating terminal (4); The heating terminal (4), the ground source heat pump unit (3) and the buried pipe heat exchanger (1) are connected in series, and the air source heat pump unit (2) and the ground source heat pump unit (3) are connected in parallel.

2. A method for applying an air-source-soil composite heat pump system for interseasonal energy storage and combined winter heating, applicable to the air-source-soil composite heat pump system for interseasonal energy storage and combined winter heating as described in claim 1, characterized in that... Includes the following steps: S1. Obtain thermal imbalance quantitative data to determine whether there is thermal imbalance in the target building's ground source heat pump system under heating and cooling operation conditions. If so, determine the initial temperature, maximum rise temperature, initial rise temperature, and rise step of the soil before heat replenishment in the target area. Based on the soil volume, initial temperature, target temperature, and specific heat capacity of the soil in the target area, determine the soil heat demand. Based on the building load data, determine the operating time period and preset number of years for summer air source heat pump heat replenishment. S2. Based on the soil heat demand and the operating time of the air source heat pump for summer heat replenishment, calculate the average daily heat replenishment of the soil in summer, determine the heating capacity of the air source heat pump based on the average daily heat replenishment, and then determine the selection of the air source heat pump system, obtain the summer heat replenishment operation strategy, and determine the initial investment of the heat replenishment system. S3. Based on the performance parameters of the air source heat pump unit and the outdoor temperature, obtain the curve and fitting formula of the air source heat pump unit heating capacity correction coefficient and the outdoor ambient temperature, and the curve and fitting formula of the input power correction coefficient and the outdoor ambient temperature to obtain the summer heat supplementation and winter heating operation strategies. S4. Based on the summer heat supplementation operation strategy of air source heat pump and the joint operation strategy of air source heat pump and ground source heat pump for winter heating, obtain the operating costs of summer heat supplementation and winter heating, set the number of heat supplementation times, and set the initial value to 0. S5. Determine whether the number of reheating cycles is less than or equal to the preset number of years. If yes, increment the number of reheating cycles by 1 and continue running. If no, record the sum of the initial investment in reheating and the operating costs of summer reheating and winter combined heating within the preset number of years, and determine whether the improved soil temperature exceeds the maximum value of soil temperature improvement. S6. If not, take the increased soil temperature as the initial increased temperature of the target area, increment the cycle number by 1, redetermine the air source heat pump system, and repeat steps S2-S5; output multiple soil heating strategies, and take the strategy with the lowest operating cost and initial investment in heating as the optimal soil heating strategy.

3. The application method of an air-source-soil composite heat pump cross-seasonal energy storage and winter combined heating system according to claim 2, characterized in that, Thermal imbalance data includes building load data and cumulative heat input and output data of the ground source heat pump system. The assessment of thermal imbalance is based on the cumulative heat output Q of the ground source heat pump system. c And cumulative heat Q h get: The ratio of cumulative heat taken out to cumulative heat released is defined as a comprehensive index. The expression is as follows: when When the cumulative heat taken out by the ground source heat pump system exceeds the cumulative heat released, a thermal imbalance occurs; when When the cumulative heat output of the ground source heat pump system is greater than or equal to the cumulative heat output, there is no thermal imbalance.

4. The application method of an air-source-soil composite heat pump cross-seasonal energy storage and winter combined heating system according to claim 2, characterized in that, The heat supplement is determined based on the soil heat demand, and the expression is: Among them, Q k The heat required by the soil in the k-th cycle is expressed in kW h, ΔT. k This represents the increase in soil temperature during the k-th cycle.

5. The application method of an air-source-soil composite heat pump cross-seasonal energy storage and winter combined heating system according to claim 2, characterized in that, Determining the heating capacity of an air source heat pump includes: Among them, Q 空 ξ is the heating power of the air source heat pump; D is the number of days the air source heat pump provides supplemental heating; t is the average daily supplemental heating hours; ξ is a correction factor used to reflect the efficiency of the air source heat pump as the outdoor temperature changes.

6. The application method of an air-source-soil composite heat pump cross-seasonal energy storage and winter combined heating system according to claim 5, characterized in that, The expression for the correction factor ξ under different outdoor temperatures is: Wherein, the heating capacity ξ(T) is the actual heating capacity of the air source heat pump at ambient temperature T; the rated heating capacity is the heating capacity of the air source heat pump under rated operating conditions.

7. The application method of an air-source-soil composite heat pump cross-seasonal energy storage and winter combined heating system according to claim 2, characterized in that, Factors that determine the performance parameters of an air source heat pump unit include heating capacity, energy efficiency ratio, noise level, investment cost, and ease of maintenance.

8. The application method of an air-source-soil composite heat pump cross-seasonal energy storage and winter combined heating system according to claim 2, characterized in that, The expression for adjusting the soil temperature rise is as follows: t k =C1+(k-1)△T s , Among them, t k ΔT represents the soil temperature rise, k represents the number of cycles, and ΔT is the soil temperature rise value. s To change the step size of soil temperature increase, C1 is the initial value of the soil temperature increase, and the corresponding expression is: Where △Q is the difference between the annual heat load and cooling load of the target building before supplemental heating, and C p ·ρ·v represents the soil heat capacity.

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