Design evaluation and operation control method of multi-energy complementary heating system

Abstract

The application discloses a design evaluation and operation regulation method of a multi-energy complementary heating system, and belongs to the technical field of building heating and energy system optimization. The method collects hourly meteorological data and building parameters, and establishes a dynamic heat load model; combined with solar energy resource level and soil heat exchange capacity, a three-level configuration strategy is adopted to construct a multi-energy complementary heating system structure; a system mathematical model is established, dynamic simulation analysis is carried out on different schemes, and operation parameters such as soil temperature, system energy efficiency and energy consumption are obtained; according to the simulation results, the laying proportion of the solar energy component is determined, and operation optimization is realized through water supply temperature regulation, water pump frequency conversion control and phase change heat storage unit configuration; further, an energy-economy-environment comprehensive evaluation model is constructed to quantitatively evaluate and sort the system schemes. The application realizes the collaborative optimization of the structure configuration, operation regulation and comprehensive evaluation of the multi-energy complementary heating system, and improves the energy utilization level and operation stability of the system.

Description

Technical Field

[0001] This invention relates to the field of building heating and energy system optimization technology, specifically to a design evaluation and operation control method for a multi-energy complementary heating system. Background Technology

[0002] With the continuous growth of building energy consumption, traditional heating methods, mainly based on coal or gas boilers, are gradually shifting towards cleaner and lower-carbon solutions. Ground source heat pumps, a technology that utilizes shallow geothermal energy for heating and cooling, offer advantages such as high energy efficiency, stable operation, and environmental friendliness, and have been widely used in building heating. However, ground source heat pump systems are prone to imbalances between heat extraction and replenishment from the underground soil during long-term operation, leading to a gradual decrease in soil temperature and affecting system operating efficiency and long-term stability.

[0003] Currently, multi-energy complementary heating systems still face the following problems in practical applications: First, the energy coupling structures are diverse, but there is a lack of systematic screening and design methods for different operating conditions and resource conditions; second, system operation and control rely heavily on experience or single parameter adjustment, making it difficult to achieve efficient synergy between multiple energy sources; and third, there is a lack of a comprehensive evaluation mechanism based on multi-dimensional performance indicators, making it difficult to conduct unified quantitative analysis and optimization decisions on the system's energy utilization efficiency, economic efficiency, and environmental benefits.

[0004] Therefore, it is necessary to propose a multi-energy complementary heating method that integrates system structure design, comprehensive performance evaluation and operation control, so as to achieve optimized configuration and efficient operation of multi-energy systems and improve the overall performance and long-term stability of the system. Summary of the Invention

[0005] To address the problems of insufficient basis for system structure selection, reliance on experience for operation and control strategies, and lack of a comprehensive evaluation mechanism for energy, economy, and environment in the design of existing multi-energy complementary heating systems, this invention proposes a design evaluation and operation control method for multi-energy complementary heating systems. Through multi-energy complementary system structure configuration, dynamic performance simulation, operation parameter optimization, and comprehensive benefit evaluation, the design and operation of the heating system are synergistically optimized.

[0006] To achieve the above objectives, the present invention adopts the following technical solution: This invention provides a method for design evaluation and operation control of a multi-energy complementary heating system, comprising the following steps: Step S001: Construct a multi-energy complementary heating system.

[0007] Collect hourly meteorological data, heating cycle parameters, and building envelope thermal parameters for the target area over many years; classify buildings into continuously heated buildings and intermittently heated buildings according to their usage characteristics, establish hourly dynamic heat load models, and obtain hourly heat load distribution curves for the heating season; Based on the hourly heat load distribution curve during the heating season, the level of regional solar energy resources, and the soil heat exchange capacity, a multi-energy complementary heating system structure is constructed according to a three-level configuration strategy. The three-level configuration strategy includes: The first configuration layer determines the configuration method of solar energy units based on the regional solar energy resource level and building heat load characteristics; The second configuration layer, based on the configuration of solar energy units, determines the series or parallel structure between the solar energy units and the ground source heat pump according to the stability of solar energy resources and soil thermal balance constraints. The third configuration layer determines the configuration method of photovoltaic power generation units based on the system's power demand and economic evaluation results; Based on the above configuration strategies, the following systems can be constructed: ground source heat pump heating system, solar thermal-ground source heat pump series heating system, solar thermal-ground source heat pump parallel heating system, photovoltaic-solar thermal-ground source heat pump series heating system, and photovoltaic-solar thermal-ground source heat pump parallel heating system.

[0008] The above technical solutions allow for the layered configuration of multi-energy complementary heating systems based on the solar energy resources, building heat load characteristics, and soil heat exchange capacity of the target area. This ensures that the system structure selection matches the regional resource conditions and building heating needs, providing a foundation for subsequent system performance analysis, operation control, and comprehensive evaluation.

[0009] Step S002: Establish a mathematical model and perform system performance simulation analysis.

[0010] Based on the multi-energy complementary heating system constructed in step S001, a mathematical model of the multi-energy complementary heating system is established by combining the meteorological conditions of the target area, the hourly heat load characteristics of the building, the level of solar energy resources, the soil thermal properties parameters, and the equipment operating parameters. The mathematical model includes a vacuum tube solar collector model, a ground source heat pump system model, a circulating water pump model, an underground buried pipe heat exchanger model, and a control system model. Based on the mathematical model, parameter configuration and dynamic simulation analysis were performed on different types of multi-energy complementary heating systems to obtain parameters such as soil temperature changes, system comprehensive energy efficiency ratio, solar heat collection, photovoltaic power generation, and unit power consumption over multiple heating cycles.

[0011] The above technical solutions can be used to uniformly model the processes of solar energy utilization, ground source heat exchange, heat pump operation, water pump distribution and control, and obtain the performance change patterns of different multi-energy complementary heating system schemes during long-term operation, providing data basis for system parameter optimization and operation regulation.

[0012] Step S003: Operation control and performance optimization of the multi-energy complementary heating system.

[0013] The solar panel installation ratio is determined based on the system performance simulation results; The heating and water supply temperature of the ground source heat pump unit is dynamically adjusted based on external ambient temperature parameters or building heat load change parameters. The operating frequencies of the ground source circulating water pump and the load-side circulating water pump are adjusted according to the external ambient temperature parameters or the building heat load change parameters. The optimized ground source heat pump subsystem is configured in different types of multi-energy complementary heating systems; A phase change thermal storage unit is configured in the multi-energy complementary heating system to realize the time-series regulation of the heating system's heat.

[0014] The above technical solutions can dynamically adjust the system operating parameters according to changes in building load and external environmental conditions, so that the heating capacity matches the load demand; at the same time, by optimizing the solar panel installation ratio and configuring phase change thermal storage units, the system's energy utilization level and operational stability can be improved.

[0015] Step S004: Comprehensive evaluation of the multi-energy complementary heating system.

[0016] Based on the system operation control and performance optimization results obtained in step S003, an energy-economy-environment comprehensive evaluation model is established to conduct a comprehensive benefit evaluation of different multi-energy complementary heating system schemes. The comprehensive evaluation model includes three evaluation dimensions: energy efficiency indicators, economic efficiency indicators, and environmental efficiency indicators.

[0017] The energy efficiency indicators are used to evaluate the energy utilization level of the heating system, including primary energy utilization rate, renewable energy self-sufficiency rate, and overall system energy efficiency ratio; the economic efficiency indicators are used to evaluate the economic feasibility of the heating system, including initial investment cost, annual net energy saving benefit, and investment payback period; and the environmental efficiency indicators are used to evaluate the environmental impact of the heating system, including carbon dioxide emission reduction and soil heat balance deviation.

[0018] Based on the direction of influence of each evaluation index on the overall performance of the system, the evaluation indexes are divided into positive and negative indicators, and a dimensionless standardization method is used to convert the indicators with different dimensions to a unified evaluation scale.

[0019] Positive indicators include: primary energy utilization rate, renewable energy self-sufficiency rate, system comprehensive energy efficiency ratio, annual net energy saving benefit, and carbon dioxide emission reduction; negative indicators include: initial investment cost, investment payback period, and soil thermal balance deviation.

[0020] For positive indicators, the following normalization process is used: For negative indicators, the following normalization method is used: Among them, S i+ Let S be the standardized score of the i-th positive indicator, 0 ≤ S i+ ≤1; S i- Let S be the standardized score of the i-th negative indicator, 0 ≤ S i- ≤1; X i X is the actual value of the i-th evaluation indicator; min X is the minimum value of this indicator among all options; max This represents the maximum value of this indicator across all options.

[0021] Then, weighting coefficients are introduced to weight each indicator, constructing a weighted evaluation function for each evaluation criterion, which is expressed as follows: In the formula U j Indicates the first j The scores for each core principle, S ji Indicates the first j Under the first core principle i Standardized scores of each indicator ω ji Indicates the first j Under the first core principle i The weight of each indicator, n Indicates the first j The number of indicators included in each core principle; Furthermore, corresponding weights are set according to the importance of the three evaluation dimensions of energy efficiency, economic efficiency and environmental efficiency, and a weighted comprehensive evaluation method is used to calculate the comprehensive evaluation value of the heating system.

[0022] Calculate the evaluation value for each evaluation dimension separately: Where U is the overall benefit score of the scheme, 0≤U≤1; ω j Let be the weight of the j-th core criterion.

[0023] The above comprehensive evaluation method can be used to quantitatively evaluate different multi-energy complementary heating system schemes from three aspects: energy utilization, economic benefits, and environmental impact, so as to achieve the optimal selection of heating system design schemes.

[0024] Further, step S001 specifically includes: The configuration of solar energy units is determined based on the intensity of regional solar radiation resources and the characteristics of building heat load. When the solar radiation resources do not meet the configuration conditions for solar energy units, a ground source heat pump heating system is used. When the solar radiation resources meet the configuration conditions for solar energy units, solar energy units are introduced as an auxiliary heat source.

[0025] After introducing solar energy units, the energy coupling form is determined based on the stability of solar energy resources and the constraints of soil thermal balance. When the coefficient of variation of solar radiation is greater than the preset threshold, it indicates that the solar energy resources fluctuate greatly, and a solar thermal-ground source heat pump series heating system is adopted. When the coefficient of variation of solar radiation is less than or equal to the preset threshold, it indicates that the solar energy resources are stable, and a solar thermal-ground source heat pump parallel heating system is adopted.

[0026] After determining the solar thermal-ground source heat pump structure, the configuration of the photovoltaic power generation unit is determined based on the system's electricity demand and economic evaluation results. When the photovoltaic power generation unit configuration conditions are met, a photovoltaic-solar thermal-ground source heat pump heating system is adopted; otherwise, a solar thermal-ground source heat pump heating system is adopted.

[0027] The above technical solutions can be used to rationally determine the multi-energy coupling mode based on regional solar energy resources, soil thermal balance constraints, and system electricity demand, thereby improving the adaptability of system structure configuration.

[0028] Further, step S002 specifically includes: A model of a vacuum tube solar collector is established, and the installation tilt angle and effective area of ​​the collector are determined based on the local solar radiation intensity, local latitude, climate conditions, load demand, and solar altitude angle.

[0029] This model can improve the rationality of solar thermal collector parameter configuration, and make the solar heat acquisition process match the regional climate conditions and building heat load requirements.

[0030] Establish a ground source heat pump system model, and determine the rated heat load, evaporator and condenser heat exchange capacity, flow rate and underground pipe length based on the building heating load, unit performance coefficient, buried pipe heat exchange capacity and safety factor.

[0031] This model enables parameter matching between ground source heat pump units and underground heat exchange systems, thereby improving system operational reliability.

[0032] Establish a circulating water pump model, and determine the flow rate and power of the water pumps on the solar side, ground source side, and load side based on the collector area, system flow requirements, pipeline resistance, terminal resistance, and head.

[0033] This model allows for the reasonable determination of the distribution parameters of the circulating system, thereby reducing energy consumption during operation.

[0034] A model of an underground buried pipe heat exchanger was established, and a heat transfer model was established based on the soil thermal conductivity, volumetric heat capacity, borehole depth, borehole spacing and buried pipe type.

[0035] This model allows for the analysis of underground heat exchange processes and soil thermal response characteristics, providing a basis for evaluating the long-term operational performance of the system.

[0036] Establish a control system model, and establish time control and temperature difference control models based on the heating period and temperature difference threshold.

[0037] This model can improve the accuracy of simulating the system's operation and control process.

[0038] Further, step S003 specifically includes: The solar module installation ratio is set using a tiered approach, with values ​​including 0.2, 0.4, 0.6, 0.8, and 1. Based on different solar module deployment ratios, corresponding operation schemes are constructed and dynamic simulation calculations are performed; Based on comparative analysis of soil temperature changes, system overall energy efficiency ratio, solar thermal collection, photovoltaic power generation, and unit power consumption parameters under different operating schemes, the configuration ratio of solar modules is determined.

[0039] The above technical solutions can determine the configuration ratio of solar modules based on simulation results, so that the solar input capacity matches the building load demand and system operation requirements.

[0040] Further, step S004 specifically includes: Energy efficiency indicators, economic efficiency indicators, and environmental efficiency indicators are divided into positive and negative indicators, and each indicator is standardized in a dimensionless manner so that the values ​​of each indicator are mapped to the [0,1] interval. We introduce weighting coefficients to weight each indicator and construct a weighted evaluation function for the evaluation criteria. Furthermore, energy efficiency criteria, economic efficiency criteria, and environmental efficiency criteria are used as upper-level evaluation units, and weight coefficients are introduced at the criterion level to construct a comprehensive system benefit evaluation function; Finally, the comprehensive benefit evaluation value was used as the evaluation basis to rank the different multi-energy complementary heating system schemes.

[0041] The above technical solutions can solve the problem of difficulty in direct comparison due to the different dimensions of different evaluation indicators, realize the comprehensive evaluation of different system solutions, and improve the scientific nature of solution selection.

[0042] Furthermore, the positive indicators include primary energy utilization rate, renewable energy self-sufficiency rate, annual net energy saving benefit, and carbon dioxide emission reduction; The negative indicators include investment payback period, initial investment cost, primary energy consumption of the system, and soil thermal balance deviation.

[0043] By setting the above indicators, the comprehensive performance of a multi-energy complementary heating system can be evaluated from three aspects: energy utilization, economic input, and environmental impact.

[0044] Furthermore, the weight of energy benefit is 0.4, the weight of environmental benefit is 0.35, and the weight of economic benefit is 0.25.

[0045] By setting the above weights, energy efficiency, environmental benefits, and economic feasibility can be comprehensively considered, so that the evaluation results meet the comprehensive evaluation requirements of multi-energy complementary heating systems.

[0046] It has the following beneficial effects: 1. This invention establishes a three-level configuration strategy for a multi-energy complementary heating system, and selects the system structure based on regional solar energy resources, building heat load characteristics, and soil heat exchange capacity, thereby improving the adaptability and rationality of the system design.

[0047] 2. By establishing a mathematical model of a multi-energy complementary heating system and conducting multi-cycle dynamic simulation analysis on different system schemes, this invention can obtain the soil temperature changes, the overall energy efficiency ratio, and energy utilization characteristics during the long-term operation of the system, providing a basis for system parameter optimization.

[0048] 3. This invention optimizes system operating parameters and improves system operating efficiency and stability by optimizing the solar module deployment ratio, adjusting heating and water supply temperatures, controlling the frequency conversion of circulating water pumps, and configuring phase change thermal storage units.

[0049] 4. This invention constructs an energy-economy-environment integrated evaluation model, which integrates energy benefits, economic benefits and environmental benefits into the evaluation system, and realizes the comprehensive evaluation and ranking of different multi-energy complementary heating system schemes, thereby improving the scientific nature and engineering application value of system scheme selection. Attached Figure Description

[0050] Figure 1 This is a schematic diagram of the overall steps of the design evaluation and operation control method of a multi-energy complementary heating system according to the present invention; Figure 2This is a schematic diagram of the decision-making process for hierarchical screening of multi-energy coupling structures in the design evaluation and operation control method of a multi-energy complementary heating system of the present invention; Figure 3 This is a schematic diagram of the ground source heat pump heating system in this invention; Figure 4 This is a schematic diagram of the solar thermal-ground source heat pump series heating system in this invention; Figure 5 This is a schematic diagram of the parallel heating system of solar thermal and ground source heat pumps in this invention; Figure 6 This is a schematic diagram of the photovoltaic-solar thermal-ground source heat pump series heating system in this invention; Figure 7 This is a schematic diagram of the photovoltaic-solar thermal-ground source heat pump parallel heating system in this invention; In the diagram: 1-Underground pipe system; 2-Ground source side water pump; 3-Heat pump unit; 4-Load side water pump; 5-Building load; 6-Solar system; 7-Heat pump; 8-Heat storage box; 9-Inverter; 10-Battery; 11-Heating valve; 12-Return valve. Detailed Implementation

[0051] 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 a part of the embodiments of the present invention, and not all of them. Other implementation methods obtained by those skilled in the art based on the embodiments of the present invention without creative effort are all within the protection scope of the present invention.

[0052] The flowchart shown in the accompanying drawings illustrates the basic implementation process of the method of the present invention and does not limit the unique execution order of the steps. In practical applications, the steps can be adjusted, combined, or partially merged according to specific operating conditions, as long as they do not deviate from the technical concept of the present invention, they all fall within the protection scope of the present invention.

[0053] Example 1: To verify the feasibility of the method of the present invention, the design evaluation and operation control method of the multi-energy complementary heating system proposed in this invention is illustrated using a heating system of a commercial building in Chengdu, Sichuan Province, China as an example. Chengdu is located in the heart of the Chengdu Plain in western Sichuan Basin, at 30°05′–31°26′ N and 102°54′–104°53′ E. It belongs to the subtropical humid monsoon climate zone. According to meteorological statistics over many years, the average annual sunshine duration in Chengdu is about 1,000 hours. The solar radiation intensity varies relatively steadily throughout the year, but is affected by seasonal changes. During the heating season, the solar radiation intensity is relatively low, and the direct solar heating capacity fluctuates to some extent. By statistically analyzing meteorological data from the past 30 years, a long-term climate benchmark was established. The year with the highest fit to the long-term average was selected from the meteorological data of the past 10 years as a typical meteorological year for subsequent heating load simulation. The commercial building's heating system is designed according to GB50189-2015 "Energy Conservation Design Standard for Public Buildings". The winter heating design temperature is set according to the standard, with a range of 18-26℃. The shopping mall atrium has no air conditioning or heating facilities. The heating period is from December 1st of the current year to February 28th of the following year, with weekday heating hours from 8:00 to 22:00 and weekend heating hours from 8:00 to 23:00. The indoor fresh air volume during working hours is 30m³. 3 / h·p, air exchange rate during non-working hours is 0.6 times / h; lighting power is 10W / m 2 The power consumption of equipment in a typical room is 20W / m. 2 The power consumption of equipment in the lobby, stairwell, and corridors is 2W / m. 2 The shopping mall faces due north and covers an area of ​​4000 square meters. 2 It is 80m wide in the east-west direction and 50m wide in the north-south direction; the central courtyard has an area of ​​800m². 2 The building is 40m wide in the east-west direction and 20m wide in the north-south direction; it has 5 floors, with floors 1-4 being 5m high and floor 5 being 7m high, for a total height of 27m; the total building area is 16,800m². 2 The heating area accounts for 0.8, and the ratio of windows to walls on the east, west, and two sides of commercial buildings is 1, while the ratio of windows to walls on the south and north sides is 0.625. refer to Figure 1 As shown in the figure, this embodiment provides a design evaluation and operation control method for a multi-energy complementary heating system, including steps S001 to S004, the specific steps of which are as follows.

[0054] S001. Construct a multi-energy complementary heating system; Collect hourly meteorological data, heating cycle parameters, and building envelope thermal parameters for the Chengdu area over many years; Based on the building's usage characteristics, the building is divided into continuous heating building conditions and intermittent heating building conditions. An hourly dynamic heat load model is established to obtain the hourly heat load distribution curve during the heating season. Based on the aforementioned heat load distribution curve, the region's solar energy resource level, and the soil's heat exchange capacity, a multi-energy complementary heating system structure is constructed according to a three-level configuration strategy. The configuration process is as follows: Figure 2 As shown.

[0055] The first configuration layer determines the configuration of solar energy units based on the solar resource level and building heat load characteristics of the target area. Based on the solar resource evaluation results, when the solar resource conditions in the target area do not meet the preset configuration requirements, a ground source heat pump heating system is constructed, with the structure as follows: Figure 3 As shown; the ground source heat pump heating system includes an underground pipe system, a ground source side circulating water pump, a heat pump unit, a load side circulating water pump, and a building load. The underground pipe system exchanges heat with the soil, and the heat pump unit increases the heat to meet the building's heating needs.

[0056] The second configuration layer, based on the configuration of solar energy units, determines the coupling form between the solar energy units and the ground source heat pump according to the solar resource stability evaluation results and soil thermal balance constraints. When the solar resource stability evaluation results are lower than a preset stability threshold, a solar thermal-ground source heat pump series heating system is constructed, with the structure as follows: Figure 4 As shown, this system preheats the circulating water on the evaporator side of the ground source heat pump through a solar thermal collector system, increasing the inlet temperature of the ground source heat pump, reducing the operating load of the heat pump, and achieving coordinated heating between the solar energy unit and the ground source heat pump. When the stability evaluation results of solar resources meet the preset stability threshold, a solar thermal-ground source heat pump parallel heating system is constructed, the structure of which is shown below. Figure 5 As shown, in this system, the solar thermal collector system and the ground source heat pump are independent heat sources, and they work together according to the building's heat load demand and solar energy output to improve the system's operational flexibility.

[0057] The third configuration layer determines the configuration method of photovoltaic power generation units based on the system's power demand and economic evaluation results.

[0058] Based on the above three-level configuration strategy, this embodiment adopts a photovoltaic-solar thermal-ground source heat pump series heating system, the structure of which is as follows: Figure 6 As shown; the system includes an underground pipe system, a ground source side water pump, a heat pump unit, a load side water pump, a building load, a solar energy system, a heat collector pump, a heat storage tank, an inverter, and a battery.

[0059] S002. Establish a mathematical model and perform system performance simulation analysis; Based on the constructed system, a mathematical model of a multi-energy complementary heating system is established, including a solar collector model, a ground source heat pump model, an underground buried pipe heat exchange model, and a circulating water pump model, etc. Based on a typical meteorological year, a dynamic simulation analysis of the system throughout the entire heating cycle was conducted, taking into account the soil thermal recovery process during the non-heating period. The following results were obtained: The building's maximum heating load is approximately 820kW, with an average load of approximately 460kW. The ground source inlet temperature is approximately 9.6℃, which increases to approximately 11.2℃ with solar assistance. The system's supply water temperature is 45℃, and the return water temperature is 35℃. Soil temperature changes and annual heat balance rate are also calculated to assess the system's long-term operational stability.

[0060] S003. Operation control and performance optimization of multi-energy complementary heating systems; The solar module installation ratio was set using a tiered approach, with values ​​of 0.2, 0.4, 0.6, 0.8, or 1. Multiple simulations were conducted to determine the optimal installation ratio as 0.4. The water supply temperature is adjusted in stages according to the outdoor temperature: When the outdoor temperature is <5℃, the water supply temperature is 45℃; when the outdoor temperature is 5-10℃, the water supply temperature is 42℃; when the outdoor temperature is >10℃, the water supply temperature is 40℃. Simultaneously adjust the operating frequency of the ground source side circulating water pump and the load side circulating water pump to ensure that the system maintains efficient operation under partial load; A phase change thermal storage unit (phase change temperature 38℃, latent heat about 200kJ / kg) is introduced to achieve heat time regulation: heat storage when solar energy is abundant, heat release when load increases or solar energy is insufficient, to achieve peak shaving and valley filling and improve soil thermal balance. S004. Comprehensive Evaluation of Multi-Energy Complementary Heating System: Based on the system operation results, an energy-economy-environment comprehensive evaluation model is constructed to evaluate the system: energy indicators include primary energy utilization rate, renewable energy self-sufficiency rate, and system comprehensive energy efficiency ratio; economic indicators include initial investment cost, annual net energy saving benefit, and investment payback period; environmental indicators include carbon dioxide emission reduction and soil heat balance deviation. The indicators are standardized and weighted to obtain a comprehensive evaluation value.

[0061] The results show that the system's overall energy efficiency ratio is 4.32; the unit heating cost is 0.36 yuan / kWh; compared with the traditional gas boiler system, energy consumption is reduced by about 41% and operating cost is reduced by about 32%. Therefore, a photovoltaic-solar-ground source heat pump series heating system with a solar module installation ratio of 0.4 was selected, coupled with a phase change thermal storage unit and a variable temperature and frequency coordinated control strategy, as the optimal multi-energy complementary heating scheme suitable for the Chengdu area.

[0062] Example 2: To further verify the applicability of the method of the present invention in different climate regions, a design evaluation and operation control method for a multi-energy complementary heating system proposed in this invention is described using a heating system of a commercial building in Lanzhou, Gansu Province, China as an example.

[0063] Lanzhou is located in the transitional zone between the Loess Plateau and the Qinghai-Tibet Plateau in Northwest my country, with geographical coordinates of 35°34′–37°07′ N and 102°35′–104°34′ E, belonging to the temperate continental climate zone. According to long-term meteorological statistics, Lanzhou has an average annual sunshine duration of approximately 2400 hours, indicating relatively abundant solar radiation resources, with good conditions for utilizing solar radiation intensity even in winter. A long-term climate benchmark was established through statistical analysis of meteorological data from the past 30 years. The year with the highest fit to the long-term average was selected from the meteorological data of the past 10 years as a typical meteorological year for subsequent heating load simulation. Lanzhou experiences low winter temperatures, resulting in significant heating demand; the heating season typically runs from November 1st of the current year to March 31st of the following year.

[0064] The commercial building is designed for heating in accordance with GB50189-2015 "Energy Conservation Design Standard for Public Buildings". The winter heating temperature is 18-24℃. The building's working hours are 8:00-18:00 on weekdays, and only the base temperature is maintained during non-working hours. The indoor fresh air volume during working hours is 30 m³ / h·p, and the air exchange rate during non-working hours is 0.5 times / h. The lighting power density is 9 W / m², and the office equipment power density is 15 W / m². The commercial building has a total floor area of ​​15,000 m², 6 floors, and is oriented north-south. The window-to-wall ratio is 0.6 on the south side, 0.4 on the north side, and 0.3 on the east-west side. The building envelope meets the requirements of the energy conservation design standard.

[0065] refer to Figure 1 As shown in the figure, this embodiment provides a design evaluation and operation control method for a multi-energy complementary heating system, including steps S001 to S004, the specific steps of which are as follows.

[0066] S001. Construct a multi-energy complementary heating system; Collect hourly meteorological data, heating cycle parameters, and building envelope thermal parameters for Lanzhou area over many years; Establish an hourly dynamic heat load model based on the building's usage characteristics to obtain the hourly heat load distribution curve during the heating season; Based on the solar energy resources, building heat load characteristics, and soil heat exchange capacity in Lanzhou, a multi-energy complementary heating system structure was constructed according to a three-level configuration strategy. The configuration process is as follows: Figure 2 As shown; The first configuration layer determines the configuration method of solar energy units based on the solar energy resources in Lanzhou and the building's heat load requirements. The second configuration layer determines the coupling structure between the solar energy unit and the ground source heat pump based on the stability of solar energy resources and soil thermal balance constraints. The third configuration layer determines the configuration method of photovoltaic power generation units based on the system's power demand and economic evaluation results.

[0067] After analyzing the three-level configuration strategy, it was determined that a photovoltaic-solar thermal-ground source heat pump parallel heating system would be adopted, the structure of which is as follows: Figure 7 As shown; The system includes an underground pipe system, a ground source side water pump, a heat pump unit, a load side water pump, a building load, a solar energy system, a heat collection pump, a heat storage tank, an inverter, a battery, a heating valve, and a return valve.

[0068] S002. Establish a mathematical model and perform system performance simulation analysis: Based on the constructed system, a mathematical model of a multi-energy complementary heating system is established, including a solar thermal collector model, a ground source heat pump model, an underground buried pipe heat exchange model, and a circulating water pump model, etc. A complete heating cycle dynamic simulation of the system was performed, taking into account the soil thermal recovery process during the non-heating period. The results are as follows: The maximum heating load is approximately 960kW, and the average load is approximately 520kW; the inlet temperature on the ground source side is approximately 10.3℃, and the evaporation side temperature is increased to 12.8℃ with solar assistance; the supply water temperature is 45℃, and the return water temperature is 35℃; the soil temperature deviation at the end of the year is approximately −0.21℃, and the annual heat balance rate is approximately 0.96, indicating that the system has good long-term operational stability. S003. Operation control and performance optimization of multi-energy complementary heating systems; Simulation comparison using graded laying ratios determined the optimal laying ratio to be 0.8, corresponding to a solar thermal collector area of ​​1600m² for commercial buildings; Water supply temperature is adjusted in stages according to outdoor temperature: When the outdoor temperature is <0℃, the water supply temperature is 45℃; when the outdoor temperature is 0~8℃, the water supply temperature is 43℃; when the outdoor temperature is >8℃, the water supply temperature is 40℃. Simultaneously adjust the operating frequency of the ground source side circulating water pump and the load side circulating water pump to enable the system to operate efficiently under partial load; Introducing a phase change thermal storage unit (phase change temperature 38℃) to achieve thermal timing regulation: When there is a surplus of solar energy, it stores heat and releases heat during periods of high nighttime load, thereby achieving peak shaving and valley filling and improving soil thermal balance. In this embodiment, the multi-energy system adopts a coordinated scheduling operation mode: when the solar thermal power is greater than 420kW, solar energy is used first; when the solar output is insufficient and the thermal storage unit meets the heat release conditions, the stored heat is released first; when the output of solar energy and thermal storage is still insufficient, the ground source heat pump is used to compensate, so as to improve the utilization rate of solar energy and reduce the unit's operating time.

[0069] S004. Comprehensive Evaluation of Multi-Energy Complementary Heating System: Based on the system operation results, an energy-economy-environment integrated evaluation model is constructed to evaluate the system: The results show that the system's overall energy efficiency ratio is 4.51; the unit heating cost is 0.33 yuan / kWh; compared with the traditional gas boiler system, energy consumption is reduced by about 44% and operating cost is reduced by about 36%. Therefore, a photovoltaic-solar-ground source heat pump parallel heating system with a solar module installation ratio of 0.8 was selected, coupled with a phase change thermal storage unit and a variable temperature and frequency coordinated control strategy, as the optimal multi-energy complementary heating scheme suitable for the Lanzhou area.

[0070] The working principle of this invention is briefly described below: This invention first collects multi-year hourly meteorological data, heating cycle parameters, and building envelope thermal parameters of the target area. Based on the building's usage characteristics, an hourly dynamic heat load model is established to obtain the hourly heat load distribution curve during the heating season. On this basis, combined with the region's solar energy resource level, building heat load characteristics, and underground soil heat exchange capacity, a multi-energy complementary heating system structure is constructed according to a three-level configuration strategy. By determining the configuration method of solar energy units, the coupling form between solar energy units and ground source heat pumps, and the configuration method of photovoltaic power generation units, a multi-energy complementary heating system scheme suitable for the target area is formed.

[0071] After the system structure is determined, a mathematical model of a multi-energy complementary heating system is established, which includes solar collectors, ground source heat pumps, underground buried pipe heat exchangers, circulating water pumps, and control systems. Dynamic simulation analysis is then performed on different system schemes to obtain operating parameters such as soil temperature changes, system comprehensive energy efficiency ratio, solar heat collection, photovoltaic power generation, and unit power consumption during system operation. This provides a basis for system performance analysis and operation optimization.

[0072] During the system operation and control phase, the solar panel installation ratio is determined based on simulation analysis results. The heating water supply temperature of the ground source heat pump unit and the operating frequency of the circulating water pump are dynamically adjusted according to external environmental temperature parameters or building heat load change parameters to achieve matching between the system's heating capacity and the building's heat load demand. At the same time, a phase change thermal storage unit is configured in the multi-energy complementary heating system to achieve heat timing regulation of the heating system through heat storage and release, thereby improving the system's adaptability to solar energy fluctuations and building load changes.

[0073] Furthermore, by constructing an energy-economy-environment comprehensive evaluation model, the operation results of different multi-energy complementary heating system schemes are standardized and weighted according to the evaluation index weights to obtain the comprehensive benefit evaluation value of each scheme. Based on the evaluation results, the multi-energy complementary heating system scheme with the higher comprehensive benefit evaluation value is determined.

[0074] The above methods enable collaborative analysis of multi-energy complementary heating systems, from structural configuration, performance simulation, operation control to comprehensive evaluation. This provides a technical basis for the design and operation optimization of multi-energy complementary heating systems under different regional conditions, thereby improving the system's energy utilization level, economy, and operational stability.

[0075] The above description is merely a preferred embodiment of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A method for design evaluation and operation control of a multi-energy complementary heating system, characterized in that, Includes the following steps: S001. Construct a multi-energy complementary heating system: Collect multi-year hourly meteorological data, heating cycle parameters, and building envelope thermal parameters of the target area; classify buildings into continuous heating buildings and intermittent heating buildings according to their usage characteristics, establish an hourly dynamic heat load model, and obtain the hourly heat load distribution curve during the heating season; based on the hourly heat load distribution curve during the heating season, the regional solar energy resource level, and the soil heat exchange capacity, construct a multi-energy complementary heating system structure according to a three-level configuration strategy. The three-level configuration strategy includes: The first configuration layer determines the configuration method of solar energy units based on the regional solar energy resource level and building heat load characteristics; The second configuration layer, under the condition of configuring solar energy units, determines the series or parallel structure between solar energy units and ground source heat pumps based on the stability of solar energy resources and soil thermal balance constraints. The third configuration layer determines the configuration method of photovoltaic power generation units based on the system's power demand and economic evaluation results; Based on the above configuration strategies, a ground source heat pump heating system, a solar thermal-ground source heat pump series heating system, a solar thermal-ground source heat pump parallel heating system, a photovoltaic-solar thermal-ground source heat pump series heating system, and a photovoltaic-solar thermal-ground source heat pump parallel heating system can be constructed. S002. Establish a mathematical model and perform system performance simulation analysis: Based on the constructed multi-energy complementary heating system, a mathematical model of the multi-energy complementary heating system is established by combining the meteorological conditions of the target area, the hourly heat load characteristics of the building, the level of solar energy resources, the soil thermal properties parameters, and the equipment operating parameters. Based on the mathematical model, parameter configuration and dynamic simulation analysis were performed on different types of multi-energy complementary heating systems to obtain parameters such as soil temperature changes, system comprehensive energy efficiency ratio, solar heat collection, photovoltaic power generation and unit power consumption during multiple heating cycles. S003. Operation control and performance optimization of multi-energy complementary heating systems: The solar panel installation ratio is determined based on the system performance simulation results; The heating and water supply temperature of the ground source heat pump unit is dynamically adjusted based on external ambient temperature parameters or building heat load change parameters. The operating frequencies of the ground source circulating water pump and the load-side circulating water pump are adjusted according to the external ambient temperature parameters or the building heat load change parameters. The optimized ground source heat pump subsystem is configured in different types of multi-energy complementary heating systems; A phase change thermal storage unit is configured in the multi-energy complementary heating system to realize the time-series regulation of the heating system's heat; S004. Comprehensive Evaluation of Multi-Energy Complementary Heating System: Based on the results of operation control and performance optimization, an energy-economy-environment comprehensive evaluation model is established; The comprehensive evaluation model includes energy benefit evaluation indicators, economic benefit evaluation indicators, and environmental benefit evaluation indicators. The evaluation indicators are standardized without dimensions and weighted according to preset weights to obtain the comprehensive benefit evaluation value of different multi-energy complementary heating system schemes. Based on the comprehensive benefit evaluation value, different system schemes are ranked, and the multi-energy complementary heating system scheme with the highest comprehensive benefit evaluation value is determined.

2. The design evaluation and operation control method for a multi-energy complementary heating system according to claim 1, characterized in that: In step S001, the three-level configuration strategy specifically includes: The configuration of solar energy units is determined based on the intensity of regional solar radiation resources and the characteristics of building heat load; when solar radiation resources do not meet the preset configuration requirements, a ground source heat pump heating system is used; when solar radiation resources meet the configuration requirements of solar energy units, solar energy units are introduced as an auxiliary heat source. After introducing solar energy units, the energy coupling form is determined based on the stability of solar energy resources and soil thermal balance constraints; The stability of solar energy resources is determined by the coefficient of variation of solar radiation during the heating season. The coefficient of variation of solar radiation represents the degree of fluctuation of solar radiation during the heating cycle. When the coefficient of variation of solar radiation is greater than a preset threshold, it indicates that the solar energy resources fluctuate greatly, and a solar thermal-ground source heat pump series heating system is adopted. When the coefficient of variation of solar radiation is less than or equal to the preset threshold, it indicates that the solar energy resources are stable, and a solar thermal-ground source heat pump parallel heating system is adopted. The configuration of photovoltaic power generation units is determined based on the system's electricity demand and economic evaluation results.

3. The design evaluation and operation control method for a multi-energy complementary heating system according to claim 2, characterized in that: When constructing the ground source heat pump heating system, the following components are used: an underground pipe system (1), a ground source side water pump (2), a heat pump unit (3), a load side water pump (4), and a building load (5); the underground pipe system (1) is connected to the evaporation side of the heat pump unit (3) through the ground source side water pump (2) to form a ground source circulation loop; the condensation side of the heat pump unit (3) is connected to the building load (5) through the load side water pump (4) to form a heating circulation loop; Based on the ground source heat pump heating system, the solar thermal-ground source heat pump series heating system is constructed by adding a solar energy system (6), a heat pump (7), and a heat storage box (8); the solar energy system (6) is connected to the heat storage box (8) through the heat pump (7); the heat storage box (8) is set in the circulation loop between the underground pipe system (1) and the heat pump unit (3), so that the heat generated by the solar energy system (6) and the ground source heat obtained by the underground pipe system (1) enter the heat pump unit (3) for heat exchange. The solar thermal-ground source heat pump parallel heating system is constructed on the basis of the ground source heat pump heating system by adding a solar energy system (6), a heat pump (7), a heat storage tank (8), a heating valve (11), and a return valve (12); the heating valve (11) is set at the evaporator side return end of the heat pump unit (3) and has a first channel and a second channel; the return valve (12) is set downstream of the ground source side water pump (2) and has a first channel and a second channel; when both the heating valve (11) and the return valve (12) open the first channel and close the second channel, a first branch is formed. When the heating valve (11) and the return valve (12) both open the second channel and close the first channel, a second branch is formed; the first branch starts from the evaporation side of the heat pump unit (3), flows through the ground source side water pump (2), the return valve (12), the heat storage tank (8), the heating valve (11) in sequence, and then returns to the evaporation side of the heat pump unit (3); the second branch starts from the evaporation side of the heat pump unit (3), flows through the ground source side water pump (2), the return valve (12), the underground buried pipe system (1), the heating valve (11) in sequence, and then returns to the evaporation side of the heat pump unit (3); By switching control of heating valve (11) and return valve (12), the solar heat exchange branch and the underground buried pipe heat exchange branch can form a parallel operation mode. The photovoltaic-thermal-ground source heat pump heating system includes a photovoltaic-thermal-ground source heat pump series heating system and a photovoltaic-thermal-ground source heat pump parallel heating system; The photovoltaic-solar-ground source heat pump series heating system is constructed by adding an inverter (9) and a battery (10) to the solar-solar-ground source heat pump series heating system. The solar system (6) adopts a photovoltaic / solar-solar integrated panel structure, which performs solar-solar-solar conversion and photoelectric conversion at the same time. The solar-solar conversion converts solar light into heat energy, and the heat is transported to the heat storage box (8) through the heat pump (7). The photoelectric conversion converts solar light into electrical energy, which is converted into electrical energy by the inverter (9) and stored by the battery (10) to provide power for the heat pump unit (3), the ground source side water pump (2), the load side water pump (4) and the heat pump (7). The photovoltaic-solar-ground source heat pump parallel heating system is constructed by adding an inverter (9) and a battery (10) to the solar-solar-ground source heat pump parallel heating system. Its structure and operation mode are the same as those of the inverter (9) and battery (10) in the photovoltaic-solar-ground source heat pump series heating system.

4. The design evaluation and operation control method for a multi-energy complementary heating system according to claim 1, characterized in that: In step S002, the mathematical model includes a vacuum tube solar collector model, a ground source heat pump system model, a circulating water pump model, an underground buried pipe heat exchanger model, and a control system model.

5. The design evaluation and operation control method for a multi-energy complementary heating system according to claim 4, characterized in that: The vacuum tube solar collector model determines the collector installation angle and effective area based on local solar radiation intensity, local latitude, climate conditions, load demand, and solar altitude angle. The ground source heat pump system model determines the rated heat load of the unit, the heat exchange capacity of the evaporator and condenser, the flow rate, and the length of the underground buried pipe based on the building heating load, the unit performance coefficient, the heat exchange capacity of the buried pipe, and the safety factor. The circulating water pump model determines the flow rate and power of the pumps on the solar energy side, ground source side, and load side based on the collector area, system flow requirements, pipeline resistance, terminal resistance, and head. The underground buried pipe heat exchanger model is established based on the soil thermal conductivity, volumetric heat capacity, drilling depth, drilling spacing and buried pipe type. The control system model establishes a time control and temperature difference control model based on the heating period and temperature difference threshold.

6. The design evaluation and operation control method for a multi-energy complementary heating system according to claim 1, characterized in that: In step S003, the solar module deployment ratio is set using a tiered approach, with values ​​including 0.2, 0.4, 0.6, 0.8, and 1; corresponding operation schemes are constructed based on different solar module deployment ratios, and dynamic simulation calculations are performed. Based on comparative analysis of soil temperature changes, system overall energy efficiency ratio, solar thermal collection, photovoltaic power generation, and unit power consumption parameters under different operating schemes, the configuration ratio of solar modules is determined.

7. The design evaluation and operation control method for a multi-energy complementary heating system according to claim 1, characterized in that: In step S004, the construction process of the comprehensive energy-economic-environment evaluation model of the multi-energy complementary heating system includes: the energy efficiency indicators include primary energy utilization rate, renewable energy self-sufficiency rate, and system comprehensive energy efficiency ratio; the economic efficiency indicators include annual net energy saving benefit, investment payback period, and initial investment cost; the environmental efficiency indicators include carbon dioxide emission reduction and soil heat balance deviation; the above indicators are divided into positive and negative indicators, and each indicator is standardized without dimensions to map the values ​​of each indicator to the [0,1] interval; then weighting coefficients are introduced to weight each indicator, and a weighted evaluation function for each evaluation criterion is constructed, the expression of which is: In the formula U j Indicates the first j The scores for each core principle, S ji Indicates the first j Under the first core principle i Standardized scores of each indicator ω ji Indicates the first j Under the first core principle i The weight of each indicator, n Indicates the first j The number of indicators included in each core principle; The evaluation values ​​of each criterion layer satisfy the following: the score of each evaluation criterion is the weighted sum of the standardized value of its corresponding indicator and the corresponding weight coefficient; Furthermore, by using energy efficiency criteria, economic efficiency criteria, and environmental efficiency criteria as upper-level evaluation units, and introducing weight coefficients at the criterion level, a comprehensive system benefit evaluation function is constructed, expressed as follows: In the formula U This represents the overall benefit score of the plan, 0 ≤ U ≤1; ω j Indicates the first j The weight of each core principle; The overall system benefit evaluation value is the weighted sum of the evaluation values ​​of each criterion layer and the corresponding weight coefficients; whereby the weights of each indicator and each criterion are set according to the preset evaluation strategy or actual application needs; Finally, based on the largest comprehensive benefit evaluation value, different multi-energy complementary heating system schemes were ranked to determine the optimal multi-energy complementary heating system scheme.

8. The design evaluation and operation control method for a multi-energy complementary heating system according to claim 7, characterized in that: The positive indicators include primary energy utilization rate, renewable energy self-sufficiency rate, system comprehensive energy efficiency ratio, annual net energy saving benefit, and carbon dioxide emission reduction. The negative indicators include investment payback period, initial investment cost, and soil thermal balance deviation.

9. The design evaluation and operation control method for a multi-energy complementary heating system according to claim 7, characterized in that: The weight for energy benefits is 0.4; the weight for environmental benefits is 0.35; and the weight for economic benefits is 0.25.

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