A high-proportion renewable energy multi-source collaborative heating construction method

Abstract

The present application belongs to the technical field of heat exchange, and particularly relates to a high-proportion renewable energy multi-source collaborative heating construction method. According to the climate conditions, resource occurrence, building form and coupling characteristics of the region, the method screens out multiple schemes composed of one or several renewable resources, takes the total cost as the minimum target value, reversely deduces the optimal solution, and obtains the high-proportion renewable energy multi-source collaborative heating system. The heating system provided by the present application all uses renewable resources, and has the advantages of environmental protection and no pollution. The heating system constructed by the present application uses the heating system to provide heating, and the annual fee of the system used in a year is the lowest, thereby reducing the heating cost. The present application is built on the TRNSYS platform, and provides the calculation of instantaneous heating. Compared with the data processed by static calculation, the obtained data is more accurate.

Description

Technical Field

[0001] This invention belongs to the field of heat exchange technology, specifically relating to a method for constructing a multi-source coordinated heating system with a high proportion of renewable energy. Background Technology

[0002] In recent years, with rapid economic development and a significant improvement in people's living standards, per capita heating energy consumption in northern my country's heating regions has been continuously increasing. However, many rural or remote areas are still not covered by centralized heating networks, and these areas still use small coal-fired or gas-fired boilers for heating. Utilizing clean energy to replace conventional energy sources as much as possible and promoting clean heating in northern regions during winter has become an important part of the energy production and consumption revolution and has received high attention from the state.

[0003] However, the use of renewable energy sources faces numerous limitations. For example, solar energy suffers from large system scale and unstable heating; biomass utilization is constrained by resource conditions and collection radius, and its boiler efficiency is low; air-source heat pumps experience severe frosting in humid areas; and ground-source heat pumps require well drilling and involve significant initial investment. In practical applications, a multi-renewable energy-integrated heating system should be established to meet the large-scale heating needs of northern my country.

[0004] However, there is currently no unified standard for the selection of specific equipment in multi-source coordinated heating systems. At the same time, the design of the heating ratio of each equipment in the system is usually calculated based on the maximum static load, ignoring the dynamic change characteristics of the load. The dynamic operating characteristics of the system are not fully considered during the design, which sometimes results in higher energy consumption and greater investment for heating from a single heat source in actual multi-source coordinated heating projects. Summary of the Invention

[0005] To address the shortcomings of related technologies, this invention provides a method for constructing a multi-source coordinated heating system with a high proportion of renewable energy, thereby solving the technical problem of high heating costs from a single renewable resource.

[0006] This invention provides a method for constructing a multi-source coordinated heating system with a high proportion of renewable energy, comprising the following steps: S1: Initial screening of heating systems: Based on the local climate conditions and resource reserves, select one or more renewable resource heating methods from the generalized heating system model to form various different heating systems; S2: Second-stage heating system: Based on the building type of the area and the coupling characteristics between renewable resource heating methods, a heating system composed of one or more renewable resource heating methods is further selected from the initial screening heating system. S3: Third screening of heating systems: Obtain the maximum heating load based on the meteorological conditions of the location, obtain the supply water temperature based on the maximum heating load, and determine the heating sequence of multiple renewable resource heating modes in the second screening heating system according to the lower limit of the supply water temperature; S4: Calculate the annual cost generated by using the heating system screened out in step S3, and select the heating system with the minimum annual cost as the high-proportion renewable energy multi-source collaborative heating system.

[0007] In other embodiments, the step S2 is constructed and processed on the TRNSYS software.

[0008] In other embodiments, the renewable resource heating modes include: solar energy, air source heat pump, water source heat pump, soil source heat pump, and biomass boiler.

[0009] In other embodiments, the sequence of turning on each device is: solar energy > water source heat pump > soil source heat pump > air source heat pump > biomass boiler.

[0010] In other embodiments, the number of the renewable resource heating modes is no more than three.

[0011] In other embodiments, the logic of the heating sequence in step S3 is: Device turn-on logic: Three comparison temperatures T1, T2 and T3 are set to compare with the actual temperature T: when T > T1, no device is turned on; when T2 < T < T1, one heating device is turned on; when T3 < T < T2, two heating devices are turned on; when T < T3, three heating devices are turned on; Device turn-off logic: Three comparison temperatures T4, T5 and T6 are set to compare with the actual temperature T: when T > T4, all devices are turned off; when T5 < T < T4, two devices are turned off; when T6 < T < T5, one heating device is turned off; when T < T6, all devices are turned off.

[0012] In other embodiments, the T3 is the supply water temperature, and its calculation formula is:

[0013] Wherein, Qmax is the maximum heating load, KW; m is the mass flow rate of the heating terminal, Kg / s; Cp is the constant pressure specific heat capacity of water, J / (Kg•℃); η is the heat exchange efficiency of the terminal heat exchanger; Ta is the ambient temperature under the maximum heating load of the terminal, ℃; T1, T2 and T3 form an arithmetic sequence; T3, T4, T5 and T6 form an arithmetic sequence.

[0014] In other embodiments, the difference between T1, T2 and T3 is 3℃, and the difference between T3, T4, T5 and T6 is 4℃.

[0015] In other embodiments, the annual fee is calculated as follows:

[0016] Where A is the annual value of investment, P is the total investment, i is the loan interest rate, and n is the equipment lifespan.

[0017] In other embodiments, the selection criteria for the renewable resource heating method are specifically as follows: The solar radiation is above 5400 MJ / m2, which is equivalent to an average daily radiation of above 3.8 kWh / m2, and the annual sunshine duration is above 3000 hours; Air source heat pump: The number of days with an average outdoor temperature of <0℃ and relative humidity of >65% accounts for less than 50% of the heating days; Water-based heat source pumps: provide heating within a radius of 4km; Biomass boilers: The amount of biomass resources in the heating area means that the operating cost of biomass boilers is lower than that of air source heat pumps for more than 50% of the heating season. Soil heat source pump: Suitability parameter B>5.

[0018] Based on the above technical solutions, the present invention provides a method for constructing a high-proportion renewable energy multi-source coordinated heating system. According to the climate conditions, resource reserves, building forms and coupling characteristics of the region, multiple schemes composed of one or more renewable resources are selected. The total investment cost is used as the minimum target value, and the optimal solution is derived to obtain a high-proportion renewable energy multi-source coordinated heating system. Attached Figure Description

[0019] The accompanying drawings, which are included to provide a further understanding of the invention and form part of this application, illustrate exemplary embodiments of the invention and, together with their description, serve to explain the invention and do not constitute an undue limitation thereof. In the drawings: Figure 1 Search logic graph for finding the system with the minimum annual fee; Figure 2 This is the TRNSYS visualization interface of the system in Scheme 1 of the embodiment; Figure 3 This is the TRNSYS visualization interface of the system in Scheme 2 of the embodiment; Figure 4 This is the TRNSYS visualization interface of the system in Scheme 3 of the embodiment; Figure 5 This is the TRNSYS visualization interface for the system in Scheme 4 of the embodiment; Figure 6 This shows the heat generation of each device under the optimal ratio. Detailed Implementation

[0020] The technical solutions in 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. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0021] This invention provides a method for constructing a multi-source coordinated heating system with a high proportion of renewable energy, comprising the following steps: S1: Initial Screening of Heating Systems: Based on the local climate conditions, building types, and resource availability, one or more renewable resource heating methods will be selected from the generalized heating system model to form various different heating systems. It is understood that climate conditions and resource availability are important factors considered in the planning, layout, and site selection of this project. Climate conditions include: local winter sunshine conditions, average temperature during the heating season, minimum temperature, humidity, etc. Resource availability includes: whether there is sufficient sunlight, the availability of rice husks, corn stalks, rice straw, etc. for combustion, and the existence of other heat energy sources.

[0022] S2: Second-stage heating system: Based on the building type of the region and the coupling characteristics between renewable resource heating methods, a heating system composed of one or more renewable resource heating methods is further selected from the initial screening heating system; it can be understood that the building type includes: rural detached houses, urban residential buildings, large urban buildings, etc.

[0023] S3: Three-screen heating system: The maximum heating load is obtained based on the local weather conditions, the water supply temperature is obtained based on the maximum heating load, and the heating sequence of multiple renewable resource heating methods in the two-screen heating system is determined based on the lower limit of the water supply temperature; it is understood that the different heating times and sequences of each renewable resource will have a significant impact on the annual cost generated in actual use.

[0024] S4: Calculate the annual cost of using the heating systems selected in step S3, and select the heating system with the lowest annual cost as the high-proportion renewable energy multi-source coordinated heating system. It can be understood that this invention aims to generate the minimum annual cost and then derives the optimal solution as the target solution.

[0025] This solution employs a multi-renewable resource co-generation heating approach, resulting in a heating system with minimal annual costs during operation and generating significant economic benefits in actual production.

[0026] In other embodiments, step S2 is implemented using TRNSYS software. Real-time changes in the heat load of heating users are calculated using the TRNSYS database. Transient simulations are performed on the system based on the heat load change curves. The instantaneous performance of the system is derived from the simulation results, and parameters such as system power consumption, biomass consumption, heat output of each device, and system operating costs are analyzed through integration. This implementation processes data dynamically, resulting in more accurate data compared to static processing.

[0027] In other embodiments, renewable resource heating methods include: solar energy, air source heat pumps, water source heat pumps, soil source heat pumps, and biomass boilers. The specific selection criteria for several renewable resources are as follows: (1) Solar energy: The most important environmental factors affecting the heat collection efficiency of solar collectors are the annual solar radiation and annual sunshine hours. The preliminary screening criteria for solar collectors are: the heating area is located in a solar energy-rich area (Zone I) or a relatively rich area (Zone II), and according to the classification criteria, the annual solar radiation on the horizontal plane should be 5400 MJ / m². 2 The above translates to an average daily radiation of 3.8 kWh / m². 2 The above areas have more than 3,000 hours of sunshine per year.

[0028] (2) Air source heat pump: Air source heat pump is currently the most widely used heating method in renewable energy heating. The main parameter affecting the performance of air source heat pump is outdoor temperature. As the air temperature decreases, the evaporation temperature of the air source heat pump unit decreases, the compression ratio of the compressor increases, and thus the coefficient of performance decreases. The preliminary screening criteria for air source heat pumps are set as follows: the number of days with an average outdoor temperature <0℃ and relative humidity >65% accounts for less than 50% of the heating days.

[0029] (3) Water source heat pump: Due to the location of the sewage treatment plant and the distribution of surrounding buildings, sewage source heat pump heating stations are often located at a certain distance from the load side. Because sewage source heat pump systems operate with small temperature differences and large flow rates, the greater the distance, the higher the investment in the transmission pipeline network and the higher the energy consumption of the pump, resulting in lower investment and system efficiency. According to the "Practical Heating and Air Conditioning Design Manual," the formula for calculating the proportion of transmission energy consumption to the total energy consumption of the heat pump unit (ns) when transmitting hot water is as follows:

[0030] Where Ns is the energy consumption of the water pump (kW), Qq is the heat exchange power that the sewage can provide (kW), and εr is the coefficient of performance (COP) of the heat pump unit. There is a certain relationship between the reasonable heating radius and the overall performance coefficient of the heat pump system. Calculations show that when the energy consumption of distribution accounts for about 20%-30% of the system's energy consumption, the COP of the sewage source heat pump system is around 3.5, and the heating radius is about 4km. When the overall COP is greater than this value, the system operates more economically. Similarly, the article "Study on the Applicability of Sewage Source Heat Pump Heating in Qingdao" points out that, from the perspective of energy saving and economy, building complexes should be located within 3.92km of the sewage treatment plant. The preliminary screening standard for air source heat pumps is set as: a heating radius within 4km.

[0031] (4) Biomass Boilers: The key factors affecting the usability of biomass boilers are the availability and market price of biomass resources. Winters in major heating areas of northern my country are relatively dry, with humidity rarely exceeding 65%. As analyzed above, air source heat pumps are generally well-suited for use in northern my country. Since biomass boilers and air source heat pumps have similar initial equipment investments, their operating costs can be compared to determine whether to choose a biomass boiler. Currently, the market price of biomass briquettes is generally around 1300 yuan / ton, making biomass boilers very expensive and uneconomical. However, in some areas with abundant biomass resources, the price of biomass briquettes may be far lower than the market price, potentially offering an advantage over air source heat pumps. Therefore, the initial screening criterion for biomass boilers is set as follows: the biomass resources in the heating area are large enough that the number of days during the heating season when the operating cost of a biomass boiler is lower than that of an air source heat pump exceeds 50% of the total heating season.

[0032] (5) Soil heat source pump: The formula for calculating parameter B, which characterizes the suitability of a soil source heat pump, is as follows:

[0033] The suitability of soil source heat pumps is taken as the system objective X; its key influencing factors are taken as attribute criteria, specifically divided into hydrogeological conditions X1, geothermal field characteristics X2, and soil and rock thermal properties X3; each attribute criterion is further divided into element indicators, where hydrogeological conditions include groundwater depth X11, aquifer thickness X12, and groundwater flow velocity X13; geothermal field characteristics include initial ground temperature X21 and geothermal gradient X22; and soil and rock thermal properties include average thermal conductivity X31 and average specific heat capacity X32. An attribute criterion comparison matrix is ​​set up to represent the relative importance of each attribute criterion, as shown in Table 2; an element indicator comparison matrix is ​​set up to represent the relative importance of each element indicator, as shown in Table 3. In Table 2, each number represents the ratio of the influence weight of the attribute criterion on the objective to the corresponding row and column, and each number represents the ratio of the influence weight of the element indicator on the attribute criterion to the corresponding row and column.

[0034] Table 1

[0035] Table 2

[0036] Yj represents the assigned value of the indicator element. The assignment criteria can be found in Table 4.

[0037] Table 3

[0038] The initial screening criterion for soil source heat pumps is set as follows: suitability parameter B > 5.

[0039] (6) Electric heating wires are very suitable as a temporary heating method under peak loads. When designing the equipment scale of a heating system, the five coldest days are usually ignored, and the heating load at the sixth lowest temperature of a single day is used as the maximum load for designing the heating system. In actual operation, electric heating wires are turned on for auxiliary heating during the five coldest days. Although the operating cost is relatively high at this time, the equipment scale of the heating system can be reduced, thus saving initial investment and being more economical overall. In actual heating projects, electric heating wires are usually equipped in the heat storage / hot water supply tank as auxiliary heating. Therefore, no preliminary screening criteria are set for electric heating wires.

[0040] In other embodiments, the order in which the devices are turned on is: solar energy > water source heat pump > soil source heat pump > air source heat pump > biomass boiler. Among these devices, solar energy has the lowest operating cost, followed by water source heat pump and soil source heat pump, then air source heat pump, and biomass boiler has the highest operating cost. The order of device use in the actual heating system is based on the level of operating cost.

[0041] In other embodiments, the renewable resource heating method is no more than three: ① When there are more than three types of heating equipment, the investment is usually large and the operation and switching between equipment is more complicated, so more than three types of equipment are not used for coordinated heating; ② For rural independent houses, the heating load is usually small, so three or more types of equipment are not used for coordinated heating, and only one or two types of equipment are considered; ③ For rural independent houses, since the initial investment of soil source heat pumps is large, the coupling of soil source heat pumps with other heating equipment is not considered, and only the method of soil source heat pumps and electric heating wires are considered.

[0042] In the above embodiments, the start-up and stop-down logics of each device are further determined. Specifically, the start-up logic uses the range of the hot water outlet temperature from the hot water tank as the basis for device start-up. Three comparison temperatures, T1, T2, and T3, are set to form four temperature ranges. The device start-up is determined based on the temperature range of the current heating temperature T, as detailed in Table 4. Table 4. Logical Relationship Between Equipment Start-up and Temperature

[0043] The shutdown logic is as follows: When the operation of the heating system causes the temperature to rise and exceed a certain target value, one of the heating devices needs to be shut down to save energy. However, the shutdown temperature of the device cannot coincide with the startup temperature; otherwise, it will lead to frequent start-ups and shutdowns, which is not only detrimental to energy saving but also affects the service life of the equipment. Therefore, temperature control precision is set for each type of heating device. If the current operation of the heating system causes the temperature to exceed the sum of the startup temperature and the temperature control precision, one of the currently operating devices can be shut down. Three comparison temperatures, T4, T5, and T6, are set to determine whether the device should be shut down, as detailed in Table 5. Table 5 Logical Relationship Between Equipment Shutdown and Temperature

[0044] Furthermore, specific values ​​for comparison temperatures T1, T2, T3, T4, T5, and T6 are set. First, the maximum heating load of the heating users is calculated, and the required supply water temperature under that load is calculated, and this temperature is set as T3. This setting ensures that the heating system can provide the required supply water temperature under any heat load. The calculation method for T3 is shown in the following formula:

[0045] In the formula, Qmax is the maximum heating load (kW); m is the mass flow rate at the heating terminal (Kg / s); Cp is the specific heat capacity of water at constant pressure (J / (Kg•℃)); η is the heat exchange efficiency of the terminal heat exchanger; and Ta is the ambient temperature at the maximum heating load at the terminal (℃). Based on this, the values ​​of T2 and T1 can be set arithmetic progressions, with the difference set to 3℃. Further, the temperature control precision for each heating scheme can be set. For example, if the hot water temperature is less than T3, three heating devices can be turned on simultaneously. When the temperature reaches the sum of T3 and the temperature control precision, one device can be turned off, and this temperature is set to T6, with the temperature control precision set to 4℃. Similarly, the specific values ​​of T4 and T5 can be obtained in this way.

[0046] In other embodiments, the annual value of investment is calculated according to the following formula:

[0047] Where A is the annual value of investment, P is the total investment, i is the loan interest rate, and n is the equipment lifespan.

[0048] The annual cost includes two parts: the annual investment cost and the operating costs.

[0049]

[0050]

[0051] Where Ac is the annual cost; Ai is the annual investment; Oc is the operating cost; Aei is the annual value of equipment and automation investment; Acon is the annual value of installation and construction investment; Ef is the operating electricity cost; Omc is the maintenance and management cost; and Ob is the cost of biomass fuel.

[0052] The optimization process aims to minimize the annual cost (min(Ac)). The constraints of the optimization process include energy balance constraints and maximum equipment load constraints.

[0053] Where Qequ,i is the actual heating power of the i-th type of heating equipment; Quser,h is the required heat load.

[0054]

[0055] Where Qequ,c is the rated heating power of the i-th type of heating equipment.

[0056] Using the heating power of each device as the optimization variable, the Hooke-Jeeves algorithm is used for automatic optimization. The automatic optimization process is as follows: Figure 1 As shown, through an automatic optimization process, the optimal heating ratio of the system is finally obtained.

[0057] Example This embodiment uses a rural detached house in a hot-summer, cold-winter region of my country as the heating source. Its floor area is 200m². 2 The heating area is 100m² 2 The design load index is 72W / m 2 The construction process of a high-proportion renewable energy multi-source coordinated heating construction method of the present invention is illustrated using an example of a heating period from October 20 of the current year to April 15 of the following year.

[0058] First, the heating system is initially screened according to step S2. The climate conditions, building types, and resource endowment of the region are as follows: the region is rich in biomass resources, has high humidity, and relatively abundant solar energy and groundwater resources. Therefore, the heating system initially screened is: solar energy, biomass boiler, and soil heat source pump.

[0059] Furthermore, following step S3, a second-stage heating system is implemented. Given that the local architecture consists primarily of detached rural houses, no other equipment can be selected when choosing a ground-source heat pump. Therefore, the following four options are available: Option 1: Soil heat source pump + electric wire heating; Option 2: Biomass boiler + electric wire heating; Option 3: Solar energy + electric wire heating; Option 4: Biomass boiler + solar energy + electric wire heating; Furthermore, four heating systems were constructed on the TRNSYS platform. The visualization interfaces of the systems constructed in Schemes 1 to 4 on the TRNSYS platform are as follows: Figures 2 to 5 As shown.

[0060] Furthermore, according to step S4, for the three-screen heating system, the first step is to calculate the required water supply temperature under the maximum heating load. Meteorological data for the selected area can be retrieved from the TRNSYS database, and the heating load is further calculated in TRNSYS. Based on this, the required water supply temperature is calculated using the aforementioned method. The calculated required water supply temperature in this embodiment is 34℃.

[0061] Furthermore, the control logic for the activation sequence of Schemes 1 to 3 is set as follows: Equipment activation procedure: When the water supply temperature is <34℃, turn on the heating equipment; when the water supply temperature is >34℃, even if the heating equipment is in the off state, it is not necessary to turn on the equipment. Equipment shutdown procedure: When the temperature rises to 38℃ after the equipment is turned on, shut down the heating equipment.

[0062] Furthermore, the control logic for the activation sequence of Scheme 4 is set as follows: Equipment activation plan: When the water supply temperature is <34℃, both the solar collector and the biomass boiler will be turned on for heating; when the water supply temperature is <37℃ but >34℃, only the solar collector will be turned on for heating; when the water supply temperature is >37℃, no heating equipment needs to be turned on.

[0063] Equipment shutdown plan: When both heating devices are turned on at the same time and the water temperature rises to 38°C, the biomass boiler will be shut down; when only solar heating is used and the temperature rises to 41°C, the solar collector will be shut down.

[0064] Furthermore, according to step S5, specifically, based on the set system operation control mode, the instantaneous operating state of the system in each scheme is simulated and calculated, and parameters such as the system's power consumption, heat output of each device, and system operating costs are obtained by integration throughout the heating season. Based on this, with the minimum annual cost as the optimization objective, the Hooke-Jeeves algorithm is used to optimize the heating ratio of each device in each selected system, and the scheme with the minimum annual cost is selected to determine the heating power of each device. The economic analysis of the system under the optimal heating ratio calculated for each scheme is shown in Table 6:

[0065] As shown in Table 6, after comparing the various schemes, Scheme 4 has the lowest annual system cost. This is because the addition of biomass boilers reduces the investment in solar collectors. At the same time, since the price of biomass raw materials in the heating area is much lower than the market price, the operating cost is also lower. Therefore, in this embodiment, the method of using multiple heat sources for coordinated heating has a lower cost than heating with a single heat source.

[0066] Ultimately, Scheme 4 was selected as the heating system for this embodiment. Under the optimal system heating ratio, the heat generation of each device is as follows: Figure 6 As shown.

[0067] Through the description of the method for constructing a high-proportion renewable energy multi-source coordinated heating system according to the present invention, it can be seen that the present invention has at least one or more of the following advantages: 1. The heating system provided by this invention uses renewable resources and has the advantages of being environmentally friendly and pollution-free; 2. The heating system constructed using this invention provides heating with the lowest annual cost, thus reducing heating costs. 3. This invention is built on the TRNSYS platform and provides calculations for instantaneous heating. Compared with static calculations, the data obtained is more accurate.

[0068] Finally, it should be noted that the various embodiments in this specification are described in a progressive manner, with each embodiment focusing on the differences from other embodiments. The same or similar parts between the various embodiments can be referred to each other.

[0069] The above embodiments are only used to illustrate the technical solutions of the present invention and not to limit them; although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications can still be made to the specific implementation of the present invention or equivalent substitutions can be made to some technical features without departing from the spirit of the technical solutions of the present invention, and all such modifications and substitutions should be covered within the scope of the technical solutions claimed in the present invention.

Claims

1. A method for constructing a multi-source coordinated heating system with a high proportion of renewable energy, characterized in that, comprising the following steps: S1: Preliminary screening of heating systems: selecting one or more renewable resource heating modes from a generalized heating system model to form a plurality of different heating systems according to the climatic conditions and resource endowment of the region; S2: Secondary screening of heating systems: further screening heating systems composed of one or more renewable resource heating modes from the preliminarily screened heating systems according to the building forms in the region and the coupling characteristics between the renewable resource heating modes; the step S2 is built and processed on TRNSYS software; S3: Tertiary screening of heating systems: obtaining the maximum heating load according to the meteorological conditions of the region, obtaining the water supply temperature according to the maximum heating load, and determining the heating sequence of the plurality of renewable resource heating modes in the secondarily screened heating systems according to the lower limit of the water supply temperature; S4: calculating the annual cost generated by using the heating system screened out in the step S3, and selecting the heating system with the minimum annual cost as the high-proportion renewable energy multi-source collaborative heating system; calculating the real-time change of the heating load of heating users through the TRNSYS database, performing transient simulation calculation on the system based on the heating load change curve, obtaining the instantaneous performance of the system according to the simulation result, and analyzing the system power consumption, biomass consumption, heat supply of each device and system operation cost through integration thereof; the renewable resource heating modes comprise: solar energy, air source heat pump, water source heat pump, soil source heat pump, and biomass boiler; the preliminary screening criteria for the renewable resource heating modes are specifically as follows: Solar radiation is 5400 MJ / m 2 The above translates to an average daily radiation of 3.8 kWh / m². 2 The above areas have more than 3,000 hours of sunshine per year; Air source heat pump: the number of days when the average outdoor ambient temperature is <0 and the relative humidity is >65% accounts for less than 50% of the heating days; Water source heat pump: the heating radius is within 4km; Biomass boiler: the amount of biomass resources in the heating area makes the operation cost of the biomass boiler during the heating period lower than that of the air source heat pump; the number of days of heat pump operation exceeds 50% of the heating period; Soil source heat pump: the suitability parameter B>5; wherein, the calculation formula of the parameter B representing the suitability degree of the soil source heat pump is: The suitability of soil source heat pumps is taken as the system objective X; its key influencing factors are taken as attribute criteria, specifically divided into hydrogeological conditions X1, geothermal field characteristics X2, and soil and rock thermal properties X3; each attribute criterion is further divided into element indicators, among which hydrogeological conditions include groundwater depth X11, aquifer thickness X12, and groundwater flow velocity X13; geothermal field characteristics include initial ground temperature X21 and geothermal gradient X22; soil and rock thermal properties include average thermal conductivity X31 and average specific heat capacity X32; where Yj is the assigned value of the indicator element; an attribute criterion comparison matrix is set to represent the relative importance degree among the attribute criteria, and an element index comparison matrix is set to represent the relative importance degree among the element indexes.

2. The method for constructing a high-proportion renewable energy multi-source coordinated heating system according to claim 1, characterized in that, The starting sequence of each device is: solar energy > water source heat pump > soil source heat pump > air source heat pump > biomass boiler.

3. The method for constructing a high-proportion renewable energy multi-source coordinated heating system according to claim 1, characterized in that, The number of the renewable resource heating modes is no more than three.

4. The method for constructing a high-proportion renewable energy multi-source coordinated heating system according to claim 3, characterized in that, The logic of the heating sequence in the step S3 is: Device starting logic: three comparison temperatures T1, T2, T3 are set to compare with the heating temperature T: when T>T1, no device is started; when T2<T<T1, one heating device is started; when T3<T<T2, two heating devices are started; when T<T3, three heating devices are started; Device shutdown logic: three comparison temperatures T4, T5, T6 are set to compare with the heating temperature T: when T>T4, all devices are shut down; when T5<T<T4, two devices are shut down; when T6<T<T5, one heating device is shut down; when T<T6, all devices are shut down.

5. The method for constructing a high-proportion renewable energy multi-source coordinated heating system according to claim 4, characterized in that, The T3 is the water supply temperature, and its calculation formula is: Where Qmax is the maximum heating load, kW; m is the mass flow rate at the heating terminal, kg / s; and Cp is the specific heat capacity of water at constant pressure, J / (kg·s). η is the heat exchange efficiency of the terminal heat exchanger; Ta is the ambient temperature under the maximum heating load at the terminal. T1, T2, and T3 form an arithmetic sequence; T3, T4, T5, and T6 form an arithmetic sequence.

6. The method for constructing a high-proportion renewable energy multi-source coordinated heating system according to claim 5, characterized in that, The temperature difference between T1, T2, and T3 is 3℃, and the temperature difference between T3, T4, T5, and T6 is 4℃.

7. The method for constructing a high-proportion renewable energy multi-source coordinated heating system according to claim 1, characterized in that, The annual fee is calculated as follows: Where A is the annual value of investment, P is the total investment, i is the loan interest rate, and n is the equipment lifespan.

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