Thermoelectric waste heat coupling heat supply system based on geothermal energy

Abstract

The invention discloses a thermoelectric waste heat coupling heat supply system based on geothermal energy, and particularly relates to the technical field of energy utilization, comprising: a geothermal energy extraction module transmits geothermal energy to a heat supply pipe network through a geothermal well and a heat pump to realize primary heat supply; the heat pump module raises the geothermal temperature to ensure stable output; the heat supply analysis module monitors the primary heat supply state and judges whether the hidden danger of heat insufficiency exists or not; if the defects exist, the overall heat supply state judgment module generates a geothermal energy heat supply index and a heat pump efficiency index, and the heat supply state is comprehensively judged; the control adjusting module triggers the thermal power plant waste heat module according to the result, and secondary temperature increasing is carried out to guarantee heat supply; the geothermal energy and the waste heat of the thermal power plant are organically coupled, the two heat sources are effectively integrated, optimal allocation of resources is achieved, the geothermal energy serves as a basic heat source to meet basic heat supply requirements, the waste heat of the thermal power plant serves as an auxiliary heat source to automatically start to supplement heat when heat supply is insufficient, and therefore continuity and stability of heat supply are guaranteed.

Description

Technical Field

[0001] The present invention relates to the technical field of energy utilization, and more specifically, to a thermoelectric waste heat coupling heating system based on geothermal energy. Background Art

[0002] In traditional heating systems, a single heat source (such as natural gas, coal-fired boilers or electric heaters) is usually used to meet heating needs. However, with the increasingly stringent requirements for energy conservation, emission reduction and environmental protection, the shortcomings of these traditional heating methods have become increasingly obvious: fossil fuels are the main energy source in traditional heating systems, with high consumption and high operating costs, which not only increases energy costs, but also relies on limited fossil resources, which does not meet the requirements of sustainable development. Traditional heating methods emit a large amount of greenhouse gases and pollutants, aggravating environmental pollution and climate change, and having adverse effects on ecosystems and human health.

[0003] Based on these problems, geothermal energy and waste heat from thermal power plants are gradually being seen as clean and promising alternative heating solutions. Geothermal energy is a renewable, low-carbon energy source that is stable and continuous, making it very suitable for heating. Waste heat from thermal power plants is waste heat generated during the power generation process. By recycling and utilizing waste heat, energy can be reused for the second time, further reducing energy consumption and costs. However, in existing technologies, geothermal energy and waste heat from thermal power plants are usually operated independently, lacking an efficient joint regulation mechanism. This separate operation mode leads to the following problems:

[0004] During peak demand periods, a single geothermal heating system often cannot meet heating demand, and the use of waste heat from thermal power plants alone has problems such as high startup costs and inflexible response, making it difficult to respond to changes in heating load in a timely manner. Geothermal energy and waste heat from thermal power plants operate independently, failing to form a coordinated heating mechanism, resulting in low utilization of the two resources, and failing to give full play to their advantages under different heating conditions, wasting precious energy resources, and easily losing balance between insufficient heating and energy waste, affecting the economy and environmental protection of the heating system.

[0005] Therefore, the present invention proposes a geothermal energy-based thermoelectric waste heat coupled heating system, which organically combines geothermal energy and thermal power plant waste heat to form a "primary heating + secondary warming" collaborative heating mode to improve the system's heating capacity and energy utilization efficiency. Summary of the invention

[0006] To achieve the above object, the present invention provides the following technical solutions:

[0007] A thermoelectric waste heat coupled heating system based on geothermal energy, comprising a geothermal energy extraction module, a heat pump module, a thermal power plant waste heat module, a heating analysis module, an overall heating state determination module, and a control and regulation module;

[0008] The geothermal energy extraction module extracts underground geothermal energy through geothermal wells and heat pump equipment and transmits it to the heating network through heat exchangers, and the heating network performs primary heating operations;

[0009] The heat pump module uses a heat pump to raise low-temperature geothermal energy to a preset heating temperature, ensuring a stable output of primary heating;

[0010] The heating analysis module is used to collect data and analyze the primary heating operation, and determine whether there is a hidden danger of insufficient heat in the primary heating according to the analysis results;

[0011] The overall heating status judgment module performs overall heating analysis when there is a hidden danger of insufficient heat in the primary heating, generates a geothermal heating index and a heat pump working efficiency index respectively, and then performs a comprehensive judgment based on the geothermal heating index and the heat pump working efficiency index. The judgment result is the state type of the overall heating;

[0012] The control and regulation module is used to generate corresponding control and regulation strategies according to the analysis results, and send activation instructions to the waste heat module of the thermal power plant when the coupled heating mechanism is triggered;

[0013] When receiving the activation command, the waste heat module of the thermal power plant enables the waste heat of the thermal power plant, couples with the heating network through the heat exchanger, and adaptively performs secondary warming operation.

[0014] In a preferred embodiment, the primary heating operation and the secondary temperature increase operation are both heating actions performed for the heating area, and the heating area is divided into multiple heat demand areas according to preset standards.

[0015] In a preferred embodiment, heat supply analysis refers to:

[0016] Calculate the difference between the geothermal source temperature and the heat pump extraction output temperature to obtain geothermal temperature difference data, obtain geothermal temperature difference data within a fixed time period, and divide the entire time period into multiple continuous temperature difference time windows W, each time window records the geothermal temperature difference data within a period of time, and forms a temperature difference time series;

[0017] The average value and variance of the temperature difference data in each temperature difference time window W are calculated, and the average value and variance of each temperature difference time window W are compared with the corresponding preset benchmark values. If the average value and variance of the temperature difference time window W are both within the corresponding preset benchmark range, the window is marked as a normal temperature difference window. If the average value or standard deviation of the temperature difference time window W exceeds the corresponding preset benchmark range, the window is marked as an abnormal temperature difference window.

[0018] In a preferred embodiment, judging whether there is a hidden danger of insufficient heat in primary heating refers to:

[0019] The ratio of the total number of abnormal temperature difference windows to the total number of temperature difference time windows W is calculated, and then compared with the preset hidden danger threshold. If the ratio is greater than the preset hidden danger threshold, it is judged that there is a hidden danger of insufficient heat for primary heating. If the ratio is less than or equal to the preset hidden danger threshold, it is judged that there is no hidden danger of insufficient heat for primary heating.

[0020] In a preferred embodiment, the steps of obtaining the geothermal energy heating index are:

[0021] According to the geothermal source temperature at time i and the heat extracted by the heat pump, the actual geothermal energy extracted is calculated:

[0022] Q i =m·C p ·(T geo -T out );Q i represents the amount of geothermal energy extracted at time i, T geo represents the geothermal source temperature at time i, T out represents the output hot water temperature at time i, C p represents the specific heat capacity of the fluid at time i, and m represents the mass flow rate of the fluid at time i;

[0023] Combined with the heat load requirements of multiple heat demand areas, the geothermal energy heating demand required by the heating area at time i is calculated:

[0024] X i represents the geothermal heating demand required by the heating area at time i, H j represents the heat load demand of the jth heat demand area at time i, ΔT j represents the difference between the heating target temperature of the jth heat demand area and the current ambient temperature at time i;

[0025] Get the difference sequence D(t) under a fixed time window. The difference sequence is obtained by the following formula:

[0026] D(t)=Q i (t)-X i (t); t is the time point in the difference sequence. During the calculation, the actual extracted geothermal energy and the geothermal heating demand required in the heating area are aligned in time;

[0027] Calculate the sliding average of the difference sequence D(t)

[0028] T represents the current time point, t represents each time point in the time window, ranging from T-N+1 to T, and N represents the size of the sliding window;

[0029] Next, the standard deviation σD(t) of the difference sequence D(t) in the sliding window is calculated, and the proportion of the number of negative differences in the difference sequence D(t) to the total number of differences is recorded as R(t);

[0030] The calculation formula of geothermal heating index is:

[0031] CESI(t) represents the geothermal heating index at time point t, and f1, f2, and f3 are all preset non-zero proportional coefficients.

[0032] The steps to obtain the heat pump efficiency index are as follows:

[0033] At each time point t, calculate the actual operating performance coefficient COP(t) of the heat pump:

[0034] TG(t) represents the heat provided by the heat pump at time t, and XH(t) represents the power consumption of the heat pump at time t;

[0035] At each time point t, calculate the theoretical maximum efficiency XL(t) of the heat pump:

[0036] RY(t) represents the temperature of the geothermal source at time t, and SC(t) represents the temperature of the heat pump output at time t;

[0037] The heat pump efficiency index calculation formula is:

[0038] Represents the heat pump working efficiency index at time point t.

[0039] In a preferred embodiment, a comprehensive judgment is made based on the geothermal energy heating index and the heat pump working efficiency index, and the judgment result is that the state type of the overall heating refers to:

[0040] In a fixed time window, the average values ​​of geothermal heating index and heat pump working efficiency index are obtained and used as input data of fuzzy logic. The state type of overall heating is used as output data of fuzzy logic. The input variables are fuzzified and their values ​​are converted into fuzzy sets. The output variables are fuzzified and their values ​​are converted into fuzzy sets. Fuzzy rules are formulated to describe the adaptability of state types under different data type combinations. The fuzzified input variables are inferred through fuzzy rules to obtain the state type of overall heating.

[0041] In a preferred embodiment, the state types of overall heating include sufficient overall heating, slightly insufficient overall heating, moderately insufficient overall heating, and highly insufficient overall heating, and when the overall heating is highly insufficient and the coupled heating mechanism is triggered, the control and regulation module sends an activation instruction to the waste heat module of the thermal power plant.

[0042] Technical effects and advantages of the present invention:

[0043] By organically coupling geothermal energy with waste heat from thermal power plants, the present invention effectively integrates the two heat sources and achieves optimal allocation of resources. Geothermal energy serves as a basic heat source to meet basic heating needs, while waste heat from thermal power plants serves as an auxiliary heat source, automatically starting to supplement heat when heating is insufficient, thereby ensuring the continuity and stability of heating. This collaborative heating method greatly improves the overall energy efficiency of the system. The present invention gives priority to the use of low-cost geothermal energy, and only uses waste heat from thermal power plants for supplementation when necessary, reducing dependence on high-cost fossil energy. This flexible heating strategy significantly reduces the operating cost of the system and provides users with a more economical heating solution.

[0044] By reducing the demand for fossil fuels, the present invention significantly reduces the emission of greenhouse gases and pollutants, which meets the current green environmental protection policy requirements. Geothermal energy and waste heat from thermal power plants are both clean energy or waste heat recovery. Through this combined heating method, the present invention provides effective support for achieving the goal of low-carbon and sustainable development. When the present invention detects that the primary heating is insufficient, it can automatically trigger the waste heat from the thermal power plant to increase the temperature, ensuring that the heating stability and reliability can be maintained even under peak heating demand.

[0045] The present invention uses fuzzy logic to conduct a comprehensive analysis of the geothermal energy heating index and the heat pump working efficiency index, and automatically adjusts the heating strategy according to the heating status type (such as sufficient heating, low degree of shortage, medium degree of shortage, and high degree of shortage) to achieve heating on demand. This intelligent control method not only improves the response speed of the system, but also avoids energy waste. By efficiently utilizing geothermal energy resources, the present invention can reduce dependence on external energy (such as electricity, natural gas, etc.) to a certain extent, improve regional energy self-sufficiency, and is suitable for application in areas far away from traditional energy supplies to improve the self-sufficiency of the heating system. BRIEF DESCRIPTION OF THE DRAWINGS

[0046] In order to facilitate understanding by those skilled in the art, the present invention is further described below in conjunction with the accompanying drawings;

[0047] Figure 1 This is a schematic diagram of a thermoelectric waste heat coupling heating system based on geothermal energy in the present invention. DETAILED DESCRIPTION

[0048] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0049] Reference Figure 1 The following embodiments are obtained:

[0050] Example 1

[0051] A thermoelectric waste heat coupled heating system based on geothermal energy, comprising a geothermal energy extraction module, a heat pump module, a thermal power plant waste heat module, a heating analysis module, an overall heating state determination module, and a control and regulation module;

[0052] The geothermal energy extraction module extracts underground geothermal energy through geothermal wells and heat pump equipment and transmits it to the heating network through heat exchangers, which performs primary heating operations; this module is used to extract underground geothermal energy. Heat is obtained from underground through geothermal wells and heat pump equipment, and then transmitted to the heating network through heat exchangers to provide basic heating resources. It is the main source of geothermal energy in the system and ensures the basic energy supply of the heating system.

[0053] The heat pump module uses a heat pump to raise the low-temperature geothermal energy to the preset heating temperature to ensure the stable output of primary heating; the function of the heat pump module is to heat the low-temperature heat source extracted from the geothermal energy to the temperature required for heating. This process can ensure that the temperature of the geothermal energy is suitable for the heating needs of the building or heating area. It ensures the temperature stability of the primary heating, so that the geothermal energy can be directly used for heating and meet the basic heat load requirements of the system.

[0054] The heating analysis module is used to collect data and analyze the primary heating operation, and determine whether there is a hidden danger of insufficient heat in the primary heating based on the analysis results; this module is mainly used to collect data and analyze the status of the primary heating, and determine whether the current heating system has sufficient heat. Through the analysis of temperature difference data, the heating analysis module can identify whether there is a hidden danger of insufficient heat in the primary heating, and provide data support for further regulation.

[0055] The overall heating status determination module performs overall heating analysis when there is a hidden danger of insufficient heat in the primary heating, generates a geothermal heating index and a heat pump efficiency index, and then conducts a comprehensive assessment based on the geothermal heating index and the heat pump efficiency index. The assessment result is the overall heating status type. When the heating analysis module detects that there is a hidden danger of insufficient heat in the primary heating, the overall heating status determination module conducts a deeper analysis of the overall heating status of the system. This module generates a "geothermal heating index" and a "heat pump efficiency index" and comprehensively analyzes the status of the heating system to determine the adequacy or insufficiency of the overall heating.

[0056] The control and regulation module is used to generate the corresponding control and regulation strategy based on the judgment results, and send an activation instruction to the thermal power plant waste heat module when the coupled heating mechanism is triggered; the control and regulation module generates the corresponding control strategy based on the judgment results of the overall heating status judgment module. When the system determines that the heating is insufficient, the module will trigger the coupled heating mechanism and send an activation instruction to the thermal power plant waste heat module to ensure that the system performs secondary heating through the thermal power waste heat.

[0057] When the thermal power plant waste heat module receives the activation command, it activates the waste heat of the thermal power plant, couples with the heating network through the heat exchanger, and adaptively performs secondary warming operation. When the geothermal energy cannot fully meet the heating demand or the heating is insufficient, the thermal power plant waste heat module will be activated. It uses the waste heat generated by the thermal power plant and transfers it to the heating system through the heat exchanger to achieve auxiliary warming. This module provides a means of secondary warming to ensure that the system can still provide stable heating when the geothermal energy is insufficient.

[0058] Both the primary heating operation and the secondary warming operation are heating behaviors for the heating area, and the heating area is divided into multiple heat demand areas according to preset standards. Primary heating refers to the process of initially utilizing geothermal energy through the geothermal energy extraction module and the heat pump module and heating it to the preset heating temperature. The direct application of geothermal energy can meet the basic heating needs of the system. This stage mainly relies on geothermal resources and does not involve the auxiliary heat source of the thermal power plant. When the heat of the primary heating is insufficient, the secondary warming of the heating is achieved by activating the thermal power plant waste heat module. The secondary warming is an auxiliary heating process that increases the overall temperature of the system by introducing the waste heat of the thermal power plant. The secondary warming ensures that the system can still provide a stable heating temperature in cold weather or high load demand, making up for the problem of insufficient geothermal heating. Coupling refers to the organic combination of geothermal energy and waste heat from thermal power plants to achieve multi-heat source joint heating. Through the coupling mechanism, the heating system can be flexibly combined between different heat sources. When the local heating is insufficient, the system will automatically trigger the warming of the waste heat from the thermal power plant through a coupling mechanism, allowing the two heat sources to work together to achieve improved heating stability and energy utilization efficiency.

[0059] Heating analysis refers to:

[0060] Calculate the difference between the geothermal source temperature and the heat pump extraction output temperature to obtain geothermal temperature difference data, obtain geothermal temperature difference data within a fixed time period, and divide the entire time period into multiple continuous temperature difference time windows W, each time window records the geothermal temperature difference data within a period of time, and forms a temperature difference time series;

[0061] The average value and variance of the temperature difference data in each temperature difference time window W are calculated, and the average value and variance of each temperature difference time window W are compared with the corresponding preset benchmark values. If the average value and variance of the temperature difference time window W are both within the corresponding preset benchmark range, the window is marked as a normal temperature difference window. If the average value or standard deviation of the temperature difference time window W exceeds the corresponding preset benchmark range, the window is marked as an abnormal temperature difference window.

[0062] The core of heating analysis is to collect the difference between the geothermal source temperature and the heat pump output temperature, which is called geothermal temperature difference data. By obtaining temperature difference data in a fixed time period and dividing it into multiple temperature difference time windows (W), the system can observe the changes in heating conditions over time in detail. Each temperature difference time window W records geothermal temperature difference data over a period of time. These windows can form a temperature difference time series, which helps the system to more clearly understand the changes in temperature difference in different time periods. By calculating the mean and variance of the data in each temperature difference window, the system can quantify the average level and fluctuation of the temperature difference in the time period (the size of the fluctuation is represented by the variance). The mean and variance of each temperature difference time window will be compared with the corresponding preset benchmark range, and the benchmark value reflects the expected level under normal heating conditions. If the mean and variance of the temperature difference window are within the preset benchmark range, it is marked as a normal temperature difference window, indicating that the heating is stable during this period. If the mean or variance exceeds the benchmark range, it is marked as an abnormal temperature difference window, which indicates that there may be problems with the heating during this period, such as insufficient heat or excessive temperature fluctuations. By identifying abnormal temperature difference windows, the system can determine during which periods of time there are potential problems with the heating system. This analysis method can help the heating system detect and respond to abnormal situations in a timely manner, avoiding insufficient or fluctuating heating that affects the heating effect.

[0063] To judge whether there is a hidden danger of insufficient heat in primary heating, we refer to:

[0064] The ratio of the total number of abnormal temperature difference windows to the total number of temperature difference time windows W is counted, and then compared with the preset hidden danger threshold. If the ratio is greater than the preset hidden danger threshold, it is judged that there is a hidden danger of insufficient heat for primary heating. If the ratio is less than or equal to the preset hidden danger threshold, it is judged that there is no hidden danger of insufficient heat for primary heating. By counting the ratio of abnormal temperature difference windows, the system can monitor the stability of primary heating in real time. If the ratio of abnormal temperature difference windows is high, it means that the heating system has failed to meet the preset temperature difference requirements for a considerable period of time, indicating that the system is at risk of insufficient heat. The preset hidden danger threshold is equivalent to the lower limit of the heating safety of the system. When the abnormal ratio exceeds the threshold, the system will judge that there is a hidden danger of insufficient heating. This method can identify potential problems in time and issue early warning signals before the heating problem seriously affects the user experience, providing a basis for subsequent adjustments. When the ratio of abnormal temperature difference windows exceeds the hidden danger threshold, the system can determine whether to take measures through subsequent judgments, such as introducing waste heat from thermal power plants for auxiliary heating, to ensure stable heating. Through a reasonable early warning mechanism, the system can dynamically allocate resources between geothermal energy and thermal power waste heat, which can not only meet the heating needs of users, but also avoid unnecessary energy waste. By judging whether there is a hidden danger of insufficient heat in the primary heating, the heating system can take remedial measures at the early stage of insufficient heating to avoid affecting user experience or system safety due to insufficient temperature. This judgment method ensures the stability of the heating system, enabling it to continue to operate reliably under adverse environmental conditions or peak heating demand.

[0065] The steps to obtain the geothermal heating index are as follows:

[0066] According to the geothermal source temperature at time i and the heat extracted by the heat pump, the actual geothermal energy extracted is calculated:

[0067] Q i =m·C p ·(T geo -T out );Q i represents the amount of geothermal energy extracted at time i, that is, the actual heat extracted from geothermal energy at time i, T geo represents the geothermal source temperature at time i, T out represents the output hot water temperature at time i, C p represents the specific heat capacity of the fluid at time i, that is, the heat required to raise the temperature of unit mass of fluid by one degree; m represents the mass flow rate of the fluid at time i, that is, the flow rate of the fluid in the geothermal well per unit time; this formula calculates the heat extracted from the geothermal source by the geothermal energy extraction module at time i, reflecting the real-time supply capacity of geothermal energy.

[0068] Combined with the heat load requirements of multiple heat demand areas, the geothermal energy heating demand required by the heating area at time i is calculated:

[0069] X i represents the geothermal heating demand required by the heating area at time i, H j represents the heat load demand (kW) of the jth heat demand area at time i, reflecting the heat demand of each area, ΔT j It represents the difference between the heating target temperature of the jth heat demand area at time i and the current ambient temperature. By multiplying the heat load demand of each area by the temperature difference, the total demand of the entire heating area is obtained, which is used as the standard for evaluating geothermal heating demand.

[0070] Get the difference sequence D(t) under a fixed time window. The difference sequence is obtained by the following formula:

[0071] D(t)=Q i (t)-X i (t); t is the time point in the difference sequence. During the calculation, the actual geothermal energy extracted and the geothermal heating demand required by the heating area are aligned in time; the difference sequence D(t) reflects the adequacy of geothermal heating at time t. If D(t) is positive, it means that the geothermal heating supply exceeds the demand; if it is negative, it means that the heating is insufficient.

[0072] Calculate the sliding average of the difference sequence D(t)

[0073] T represents the current time point, t represents each time point in the time window, changing from T-N+1 to T, and N represents the size of the sliding window, that is, the length of the time period for average calculation; the sliding average is used to smooth the fluctuations of the difference sequence, reflecting the average level of heating difference over a period of time, and avoiding short-term fluctuations affecting heating evaluation.

[0074] Then, the standard deviation σD(t) of the difference sequence D(t) in the sliding window is calculated. The standard deviation indicates the degree of fluctuation of the difference sequence in the current sliding window. The larger the standard deviation, the more drastic the fluctuation of the heating difference, and the poorer the heating stability of the system; the smaller the standard deviation, the more stable the heating system is, and the proportion of the number of negative differences in the difference sequence D(t) to the total number of differences is recorded as R(t); the proportion of negative differences is used to quantify the frequency of insufficient heating. The higher the proportion, the higher the frequency of insufficient heating, and additional heating measures may need to be taken.

[0075] The calculation formula of geothermal heating index is: CESI(t) represents the geothermal heating index at time point t, and f1, f2, and f3 are all preset non-zero proportional coefficients. The geothermal heating index (CESI) is a key indicator for evaluating the heating status of geothermal energy systems. The larger the index value, the closer the geothermal energy extraction is to or exceeds the heating demand, and the more sufficient the heating situation is; the smaller the index value, the higher the risk of insufficient heating. The larger the CESI, the stronger the geothermal heating capacity is, which can meet or even exceed the current heating demand, and the heating system operates more stably; the smaller the CESI, the insufficient heating and the need for auxiliary heating may be required.

[0076] The steps to obtain the heat pump efficiency index are as follows:

[0077] At each time point t, calculate the actual operating performance coefficient COP(t) of the heat pump:

[0078] TG(t) represents the heat provided by the heat pump at time point t (usually in kW), XH(t) represents the power consumption of the heat pump at time point t (usually in kW); COP(t) represents the actual efficiency of the heat pump system at time point t, reflecting the amount of heat that can be generated per unit of power consumption. The higher the COP(t) value, the higher the efficiency of the heat pump at that moment, and the better the energy efficiency performance.

[0079] At each time point t, calculate the theoretical maximum efficiency XL(t) of the heat pump:

[0080] RY(t) represents the geothermal source temperature at time t (usually in °C), SC(t) represents the output temperature of the heat pump at time t (usually in °C); XL(t) represents the theoretical maximum efficiency of the heat pump system at time t, which is determined by the difference between the geothermal source temperature and the output temperature. This indicator represents the maximum energy efficiency that the heat pump can achieve under ideal conditions. The higher XL(t) is, the higher the theoretical efficiency of the heat pump under the temperature difference condition.

[0081] The heat pump efficiency index calculation formula is:

[0082] Represents the heat pump working efficiency index at time point t. HPWEI(t) represents the ratio of the actual efficiency of the heat pump at time point t to the theoretical maximum efficiency, reflecting the working efficiency level of the heat pump system. This index is used to evaluate the effective operating status of the heat pump at a specific time point. If HPWEI(t) is close to 100%, it means that the actual working efficiency of the heat pump is close to its theoretical maximum efficiency; if it is less than 100%, it means that there is a certain loss in the working efficiency of the heat pump and it has not reached the optimal state.

[0083] Based on the geothermal energy heating index and heat pump efficiency index, the overall heating status type is:

[0084] In a fixed time window, the average values ​​of geothermal heating index and heat pump working efficiency index are obtained and used as input data of fuzzy logic. The state type of overall heating is used as output data of fuzzy logic. The input variables are fuzzified and their values ​​are converted into fuzzy sets. The output variables are fuzzified and their values ​​are converted into fuzzy sets. Fuzzy rules are formulated to describe the adaptability of state types under different data type combinations. The fuzzified input variables are inferred through fuzzy rules to obtain the state type of overall heating.

[0085] Within a preset time window (for example, the past few hours or days), the average values ​​of the geothermal heating index and the heat pump efficiency index are calculated respectively. These average values ​​can smooth out the impact of instantaneous fluctuations and reflect the overall state of the system during this time period. The average values ​​of the geothermal heating index and the heat pump efficiency index are used as input variables of the fuzzy logic system. The overall heating status type (for example, overall heating is sufficient, low degree is insufficient, medium degree is insufficient, high degree is insufficient) is used as the output variable of the fuzzy logic system. Fuzzy processing of input variables:

[0086] The average geothermal heating index and the average heat pump efficiency index are converted into fuzzy sets respectively. The purpose of this step is to fuzzify the values ​​so that the system can judge the state according to different value ranges. For example, the average geothermal heating index can be divided into three fuzzy sets of "high", "medium" and "low"; the average heat pump efficiency index can also be divided into similar fuzzy sets.

[0087] The output variable - the overall heating status type, is fuzzified and divided into several possible fuzzy sets, such as "sufficient heating", "low deficiency", "moderate deficiency" and "high deficiency".

[0088] Each status type corresponds to a different system heating situation, which can help the system take different measures according to the current status.

[0089] Based on the understanding of the heating system, fuzzy rules are formulated to map the heating status under different input data combinations to the output status type.

[0090] Rule 1: If the average value of the geothermal heating index is "high" and the average value of the heat pump working efficiency index is "high", the overall heating status type is "sufficient heating". Rule 2: If the average value of the geothermal heating index is "low" and the average value of the heat pump working efficiency index is "medium", the overall heating status type is "moderately insufficient". Rule 3: If the average value of the geothermal heating index is "low" and the average value of the heat pump working efficiency index is "low", the overall heating status type is "highly insufficient". These rules can be flexibly formulated according to actual conditions to ensure that the system can accurately judge the current heating status.

[0091] The fuzzified input variables (average value of geothermal heating index and average value of heat pump working efficiency index) are inferred through fuzzy rules to generate fuzzy output, that is, the state type of overall heating. The fuzzy reasoning process calculates the output fuzzy set according to the set fuzzy rules to obtain the fitness of each state type. According to the reasoning results, the output variables are defuzzified to obtain a clear state type of overall heating (such as "sufficient heating", "low degree insufficient", etc.). This state type will serve as the current heating state of the system and provide a basis for further regulation of the system.

[0092] The status types of overall heating include sufficient overall heating, insufficient overall heating to a low degree, moderately insufficient overall heating, and highly insufficient overall heating. When the overall heating is highly insufficient and the coupled heating mechanism is triggered, the control and regulation module sends an activation instruction to the waste heat module of the thermal power plant.

[0093] The control and adjustment module is used to generate corresponding control and adjustment strategies based on the analysis results, which refers to:

[0094] Adequate heating means that the current system is running well and no additional regulation is required. In the low-deficient state, the heating system is slightly insufficient, but it is still close to demand overall. The following measures can be taken to make small adjustments: Improve the operating efficiency of the heat pump: By optimizing the operating parameters of the heat pump, such as increasing the power output of the heat pump, optimizing the temperature setting value, etc., the heat pump can more effectively increase the heating temperature of geothermal energy. Increase the operating time of the heat pump: Appropriately extend the operating time of the heat pump during peak heat usage hours to ensure that the amount of geothermal energy extracted can meet demand. Adjust load distribution: Redistribute the heating load among the heat demand areas, give priority to ensuring the heating of high-demand areas, and reduce the heating amount of low-demand areas to achieve an overall balance.

[0095] In the moderate shortage state, the heat shortage is more obvious, but the waste heat from the thermal power plant is still not introduced. The following measures can be used to supplement the heat supply:

[0096] Add auxiliary heating equipment: In addition to heat pumps, small auxiliary heating equipment (such as electric heaters) can be used to heat water and increase the heating temperature to make up for the lack of heating. These devices usually consume a small amount of electricity and will not significantly increase the cost of the system. Enable intermittent heating: According to the actual needs of each area, adopt an intermittent heating strategy, that is, centralized heating during peak heat usage periods and reduced heating during off-peak periods to optimize the use of geothermal energy. Adjust the heat pump cycle frequency: Appropriately increase the heat pump cycle frequency to increase the heat exchange rate of the heat pump and increase the heating temperature. Increase the geothermal water flow rate: Appropriately increase the water flow rate in the geothermal well to extract more thermal energy in a short period of time and increase the overall heating supply.

[0097] The coupling of the waste heat module of the thermal power plant and the secondary warming are triggered only after receiving the activation command. The reason for this design is that the system gives priority to using geothermal energy to meet the heating demand, and only considers the waste heat of the thermal power plant for supplementation when the geothermal energy is insufficient.

[0098] Geothermal energy is a renewable energy source with the advantages of low cost and low carbon emissions. The system relies on geothermal energy for primary heating first to ensure the greenness, environmental protection and economy of energy. Although waste heat from thermal power plants is also a form of waste heat recovery, it may require additional facilities and operating costs compared to geothermal energy. Therefore, the waste heat module is only activated when geothermal energy is insufficient to provide sufficient heating, which can effectively reduce the operating costs of the system.

[0099] If the system directly introduces waste heat from the thermal power plant when the heating supply is sufficient or only slightly insufficient, it may lead to over-coupling and energy waste. The system accurately judges the heating status through the heating analysis and overall status judgment module, and triggers the coupling mechanism only when it is highly insufficient, ensuring that the heating operation is only carried out when necessary, improving the overall efficiency of the system.

[0100] Secondary warming is an important means to cope with fluctuations in heating demand. By triggering secondary warming when geothermal heating is insufficient, the system can adaptively respond to changes in demand and avoid excess energy or unnecessary high-temperature heating caused by premature coupling. The setting of coupling trigger conditions allows the system to flexibly adapt to changes in demand and achieve dynamic adjustments under extreme weather or peak heating demand, ensuring user experience and heating stability.

[0101] The activation of the waste heat module of the thermal power plant requires the coordination of the operation of the waste heat recovery system and heat exchange equipment of the power plant. And the supply of waste heat from the thermal power plant needs to be adaptively adjusted during coupling. Frequent coupling may bring unnecessary load to the thermal power plant and affect its normal operation. When the heating demand is relatively low or the geothermal heating is sufficient, avoiding coupling operation can reduce the additional burden on the thermal power plant and make the control of the entire system simpler and more predictable.

[0102] The above formulas are all dimensionless and numerical calculations. The formula is a formula for the most recent real situation obtained by collecting a large amount of data and performing software simulation. The preset parameters in the formula are set by technicians in this field according to actual conditions.

[0103] It should be understood that in the various embodiments of the present application, the size of the serial numbers of the above-mentioned processes does not mean the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of the present application.

[0104] Those of ordinary skill in the art will appreciate that the units and algorithm steps of each example described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Professional and technical personnel can use different methods to implement the described functions for each specific application, but such implementation should not be considered to be beyond the scope of this application.

[0105] Those skilled in the art can clearly understand that, for the convenience and brevity of description, the specific working processes of the systems, devices and units described above can refer to the corresponding processes in the aforementioned method embodiments and will not be repeated here.

[0106] The above is only a specific implementation of the present application, but the protection scope of the present application is not limited thereto. Any person skilled in the art who is familiar with the present technical field can easily think of changes or substitutions within the technical scope disclosed in the present application, which should be included in the protection scope of the present application. Therefore, the protection scope of the present application should be based on the protection scope of the claims.

Claims

1. A thermoelectric waste heat coupling heating system based on geothermal energy, characterized in that: It includes geothermal energy extraction module, heat pump module, thermal power plant waste heat module, heating analysis module, overall heating status determination module, and control and regulation module; The geothermal energy extraction module extracts underground geothermal energy through geothermal wells and heat pump equipment and transmits it to the heating network through heat exchangers, and the heating network performs primary heating operations; The heat pump module uses a heat pump to raise low-temperature geothermal energy to a preset heating temperature, ensuring a stable output of primary heating; The heating analysis module is used to collect data and analyze the primary heating operation, and determine whether there is a hidden danger of insufficient heat in the primary heating according to the analysis results; The overall heating status judgment module performs overall heating analysis when there is a hidden danger of insufficient heat in the primary heating, generates a geothermal heating index and a heat pump working efficiency index respectively, and then performs a comprehensive judgment based on the geothermal heating index and the heat pump working efficiency index. The judgment result is the state type of the overall heating; The control and regulation module is used to generate corresponding control and regulation strategies according to the analysis results, and send activation instructions to the waste heat module of the thermal power plant when the coupled heating mechanism is triggered; When receiving the activation command, the waste heat module of the thermal power plant enables the waste heat of the thermal power plant, couples with the heating network through the heat exchanger, and adaptively performs secondary warming operation.

2. The thermoelectric waste heat coupling heating system based on geothermal energy according to claim 1 is characterized in that: Both the primary heating operation and the secondary warming operation are heating behaviors for the heating area, and the heating area is divided into multiple heat demand areas according to preset standards.

3. The thermoelectric waste heat coupling heating system based on geothermal energy according to claim 2 is characterized in that: Heating analysis refers to: Calculate the difference between the geothermal source temperature and the heat pump extraction output temperature to obtain geothermal temperature difference data, obtain geothermal temperature difference data within a fixed time period, and divide the entire time period into multiple continuous temperature difference time windows W, each time window records the geothermal temperature difference data within a period of time, and forms a temperature difference time series; The average value and variance of the temperature difference data in each temperature difference time window W are calculated, and the average value and variance of each temperature difference time window W are compared with the corresponding preset benchmark values. If the average value and variance of the temperature difference time window W are both within the corresponding preset benchmark range, the window is marked as a normal temperature difference window. If the average value or standard deviation of the temperature difference time window W exceeds the corresponding preset benchmark range, the window is marked as an abnormal temperature difference window.

4. The thermoelectric waste heat coupling heating system based on geothermal energy according to claim 3 is characterized in that: To judge whether there is a hidden danger of insufficient heat in primary heating, we refer to: The ratio of the total number of abnormal temperature difference windows to the total number of temperature difference time windows W is calculated, and then compared with the preset hidden danger threshold. If the ratio is greater than the preset hidden danger threshold, it is judged that there is a hidden danger of insufficient heat for primary heating. If the ratio is less than or equal to the preset hidden danger threshold, it is judged that there is no hidden danger of insufficient heat for primary heating.

5. The thermoelectric waste heat coupling heating system based on geothermal energy according to claim 4 is characterized in that: The steps to obtain the geothermal heating index are as follows: According to the geothermal source temperature at time i and the heat extracted by the heat pump, the actual geothermal energy extracted is calculated: Q i =m·C p ·(T geo -T out );Q i represents the amount of geothermal energy extracted at time i, T geo represents the geothermal source temperature at time i, T out represents the output hot water temperature at time i, C p represents the specific heat capacity of the fluid at time i, and m represents the mass flow rate of the fluid at time i; Combined with the heat load requirements of multiple heat demand areas, the geothermal energy heating demand required by the heating area at time i is calculated: X i represents the geothermal heating demand required by the heating area at time i, H j represents the heat load demand of the jth heat demand area at time i, ΔT j represents the difference between the heating target temperature of the jth heat demand area and the current ambient temperature at time i; Get the difference sequence D(t) under a fixed time window. The difference sequence is obtained by the following formula: D(t)=Q i (t)-X i (t); t is the time point in the difference sequence. During the calculation, the actual extracted geothermal energy and the geothermal heating demand required in the heating area are aligned in time; Calculate the sliding average of the difference sequence D(t) T represents the current time point, and t represents each time point in the time window, changing from T-N+1 to T; Next, the standard deviation σD(t) of the difference sequence D(t) in the sliding window is calculated, and the proportion of the number of negative differences in the difference sequence D(t) to the total number of differences is recorded as R(t); The calculation formula of geothermal heating index is: CESI(t) represents the geothermal heating index at time point t, and f1, f2, and f3 are all preset non-zero proportional coefficients.

6. The thermoelectric waste heat coupling heating system based on geothermal energy according to claim 5 is characterized in that: The steps to obtain the heat pump efficiency index are as follows: At each time point t, calculate the actual operating performance coefficient COP(t) of the heat pump: TG(t) represents the heat provided by the heat pump at time t, and XH(t) represents the power consumption of the heat pump at time t; At each time point t, calculate the theoretical maximum efficiency XL(t) of the heat pump: RY(t) represents the temperature of the geothermal source at time t, and SC(t) represents the temperature of the heat pump output at time t; The heat pump efficiency index calculation formula is: HPWEI(t) represents the heat pump efficiency index at time point t.

7. The thermoelectric waste heat coupling heating system based on geothermal energy according to claim 6 is characterized in that: Based on the geothermal energy heating index and heat pump efficiency index, the overall heating status type is: In a fixed time window, the average values ​​of geothermal heating index and heat pump working efficiency index are obtained and used as input data of fuzzy logic. The state type of overall heating is used as output data of fuzzy logic. The input variables are fuzzified and their values ​​are converted into fuzzy sets. The output variables are fuzzified and their values ​​are converted into fuzzy sets. Fuzzy rules are formulated to describe the adaptability of state types under different data type combinations. The fuzzified input variables are inferred through fuzzy rules to obtain the state type of overall heating.

8. The thermoelectric waste heat coupling heating system based on geothermal energy according to claim 7 is characterized in that: The status types of overall heating include sufficient overall heating, insufficient overall heating to a low degree, moderately insufficient overall heating, and highly insufficient overall heating. When the overall heating is highly insufficient and the coupled heating mechanism is triggered, the control and regulation module sends an activation instruction to the waste heat module of the thermal power plant.

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