Thermal power plant high-capacity heat supply method and device based on hot water energy storage and off-peak electricity utilization

Abstract

The invention discloses a thermal power plant high-capacity heat supply method and device based on hot water energy storage and off-peak electricity utilization, and the method comprises the following steps: S1, carrying out the time-power matrix division of off-peak electricity energy storage window data, and obtaining heat storage time period units; s2, electric-heat conversion efficiency calculation is conducted on the heat storage time period unit, and time period heat power data are obtained; s3, heat storage system parameters are set; s4, generating medium temperature field distribution data; s5, generating a thermal characteristic curve of the heat storage process; and S6, checking the pressure-bearing performance of the heat storage device according to the thermal characteristic curve. According to the method, time-power matrix division is carried out on off-peak electricity energy storage window data, a continuous energy storage window is decomposed into heat storage time period units, off-peak electricity of a power grid can be fully utilized for energy storage, the utilization rate of electric power resources is increased, pressure bearing performance checking is carried out, and the structural safety of a heat storage device is guaranteed.

Description

Technical Field

[0001] This invention relates to the field of thermal power plant heating technology, and in particular to a method and apparatus for large-capacity heating in thermal power plants based on hot water energy storage and off-peak electricity utilization. Background Technology

[0002] In the current energy structure, thermal power plants, as important energy suppliers, undertake the dual tasks of power generation and heating. However, the power grid load exhibits peak-valley differences, with a relative surplus of electricity supply during off-peak hours, resulting in underutilization of electrical resources and energy waste.

[0003] Existing thermal power plant heating systems lack effective energy storage methods to absorb off-peak electricity. Furthermore, the thermodynamic characteristics of the storage medium are difficult to accurately grasp during the storage process, resulting in low storage efficiency, significant heat loss, and unreliable structural safety of the storage devices. Traditional thermal storage methods often employ simple energy storage models, failing to achieve refined modeling and dynamic simulation of the storage process. This lack of scientifically accurate data support for the design and operation of thermal storage systems ultimately affects the stability and economic efficiency of large-capacity heating in thermal power plants. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to provide a method and device for large-capacity heating in thermal power plants based on hot water energy storage and off-peak electricity utilization.

[0005] The technical solution adopted by this invention to solve the above-mentioned technical problems is: a large-capacity heating method for thermal power plants based on hot water energy storage and off-peak electricity utilization, comprising the following steps:

[0006] S1: Divide the off-peak electricity storage window data into time-power matrix to obtain thermal storage period units; the time-power matrix is ​​a data structure that discretizes the off-peak electricity storage window in two dimensions according to time and expected input power;

[0007] The thermal storage period unit is the smallest simulated time segment in the time-power matrix that has a definite start and end time and constant or variable electrical power input characteristics;

[0008] S2: Calculate the electrothermal conversion efficiency of the thermal storage time unit to obtain the time period thermal power data;

[0009] S3: Set the parameters of the thermal storage system;

[0010] S4: Use the thermal power data of the time period to simulate the thermodynamic state of the thermal storage medium and generate medium temperature field distribution data;

[0011] S5: Perform dynamic heat loss analysis on the temperature field distribution data using the parameters of the thermal storage system to generate a thermal characteristic curve of the thermal storage process;

[0012] S6: Verify the pressure-bearing performance of the thermal storage device based on the aforementioned thermodynamic characteristic curve.

[0013] Preferably, in step S1, the specific method for dividing the off-peak electricity storage window data into a time-power matrix is ​​as follows: the continuous off-peak electricity storage window is discretized into multiple time period units with clear heat input characteristics according to the time step and power level, and uniformly divided using a fixed time step.

[0014] Preferably, in step S2, the electrothermal conversion efficiency is the proportion of input electrical energy converted into effective thermal energy by the electric heating device within a set thermal storage period unit.

[0015] The time period thermal power data is the effective thermal input power sequence within each thermal storage time period unit after correction for electrothermal conversion efficiency.

[0016] Calculate the thermal power data for each time period: For each thermal storage unit, call the efficiency curve of the electric boiler under different load rates, calculate the effective thermal output power after electrothermal conversion efficiency correction for each time period, and form a time period thermal power data sequence.

[0017] Preferably, in step S3, the thermal storage system parameters are a set of engineering design parameters that describe the geometry, materials, and operating boundaries of the thermal storage device.

[0018] Preferably, in step S4,

[0019] The heat storage medium is hot water, which is provided by the circulating water system of the heating system of the thermal power plant.

[0020] The medium temperature field distribution data is a dataset of the temperature distribution of the thermal storage medium in the spatial and temporal dimensions during the thermal storage process.

[0021] Preferably, in step S5, the specific method for performing dynamic heat loss analysis on the temperature field distribution data through the parameters of the thermal storage system is as follows: the temperature field is coupled with the tank wall structure and ambient temperature, the heat loss per unit time is calculated and integrated to obtain the effective heat storage attenuation curve, and the overall heat loss is quickly estimated based on the lumped parameter method.

[0022] Preferably, in step S6, the pressure bearing performance verification is based on the highest temperature and pressure in the thermodynamic characteristic curve of the thermal storage process to verify whether the structural strength of the storage tank meets the safety specifications.

[0023] An apparatus utilizing the aforementioned heating method includes:

[0024] The data partitioning unit is used to partition the off-peak electricity storage window data into a time-power matrix to obtain thermal storage period units; the time-power matrix is ​​a data structure that discretizes the off-peak electricity storage window in two dimensions according to time and expected input power; the thermal storage period unit is the smallest simulated time segment in the time-power matrix that has a definite start and end time and constant or variable power input characteristics.

[0025] An efficiency calculation unit, connected to the data partitioning unit, is used to calculate the electrothermal conversion efficiency of the thermal storage period unit to obtain the period thermal power data. The electrothermal conversion efficiency is the proportion of input electrical energy converted into effective thermal energy by the electric heating device within a set thermal storage period unit. The period thermal power data is the effective thermal input power sequence within each thermal storage period unit after correction for electrothermal conversion efficiency.

[0026] The parameter setting unit is used to set and store the parameters of the thermal storage system;

[0027] The thermodynamic simulation unit is connected to the efficiency calculation unit and the parameter setting unit respectively, and is used to simulate the thermodynamic state of the thermal storage medium using the time period thermal power data and thermal storage system parameters to generate medium temperature field distribution data.

[0028] The heat loss analysis unit is connected to the parameter setting unit and the thermodynamic simulation unit respectively, and is used to perform dynamic heat loss analysis on the temperature field distribution data through the parameters of the thermal storage system, and generate the thermodynamic characteristic curve of the thermal storage process.

[0029] The pressure-bearing verification unit is connected to the heat loss analysis unit and is used to verify the pressure-bearing performance of the thermal storage device based on the thermodynamic characteristic curve.

[0030] Preferably, the pressure-bearing performance verification method of the pressure-bearing verification unit is: based on the highest temperature and pressure in the thermodynamic characteristic curve of the thermal storage process, verify whether the structural strength of the storage tank meets the safety specifications.

[0031] The beneficial effects of this invention are:

[0032] This invention divides the off-peak electricity energy storage window data into a time-power matrix, decomposing the continuous energy storage window into thermal storage time period units. This allows for full utilization of off-peak electricity in the power grid for energy storage, improving the utilization rate of power resources and reducing energy waste.

[0033] This invention combines the characteristic curve of electric heating equipment to calculate the electrothermal conversion efficiency and obtain time-period thermal power data. It can capture the non-uniform temperature rise characteristics inside the heat storage medium and generate medium temperature field distribution data, providing reliable input for subsequent heat loss analysis.

[0034] This invention performs pressure-bearing performance verification, ensuring the structural safety of the thermal storage device. Attached Figure Description

[0035] Figure 1 This is a flowchart of the heating method of the present invention;

[0036] Figure 2 This is a flowchart of step S1 in this invention;

[0037] Figure 3 This is a schematic diagram of the thermodynamic characteristic curve of the thermal storage process in step S5 of the present invention, which is a dynamic heat loss analysis.

[0038] Figure 4 This is a schematic diagram showing the relationship between the highest temperature and pressure in step S6 of the present invention for verifying the pressure-bearing performance. Detailed Implementation

[0039] The present invention will be further described in detail below with reference to specific embodiments.

[0040] A thermal power plant plans to build hot water storage tanks for off-peak electricity energy storage. The present invention, based on hot water energy storage and off-peak electricity utilization, is used for large-capacity heating in thermal power plants. Figure 1 As shown, the specific implementation steps are as follows:

[0041] S1: As Figure 2 As shown, the data of off-peak electricity energy storage window is divided into time-power matrix to obtain thermal storage time period units;

[0042] The time-power matrix is ​​a data structure that discretizes the off-peak electricity storage window in two dimensions according to time and expected input power, and is used to decompose the continuous energy storage window into time-series energy units that can be independently modeled and scheduled; the thermal storage period unit is the smallest simulation time segment in the time-power matrix with definite start and end times and constant or variable power input characteristics, and serves as the basic time granularity for calculating electrothermal conversion efficiency and simulating thermodynamic state.

[0043] like Figure 2 As shown, the specific method for dividing the time-power matrix of the off-peak electricity storage window data is as follows: the continuous off-peak electricity storage window is discretized into multiple time period units with clear heat input characteristics according to the time step and power level.

[0044] For example, processing off-peak electricity storage window data: Off-peak electricity period: The grid-approved off-peak electricity window is 00:00-06:00 (6 hours in total); using a fixed time step of 15 minutes, the window data is divided into a time-power matrix, resulting in 24 thermal storage time period units. Each time period unit has a clear start and end time and power input characteristics. Power acquisition accuracy: ±0.1MW; Time-power matrix dimensions: 24 time period units × 1 power dimension.

[0045] S2: Calculate the electrothermal conversion efficiency of the thermal storage period unit to obtain the thermal power data for the period.

[0046] The electrothermal conversion efficiency is the proportion of input electrical energy converted into effective thermal energy by the electric heating device within a set thermal storage period unit. It is used to correct the theoretical electrical power input value and obtain the actual effective thermal power that can be used for thermal storage.

[0047] The time-period thermal power data is the effective heat input power sequence within each thermal storage time period unit after correction for electrothermal conversion efficiency.

[0048] Calculate the thermal power data for each time period: For each thermal storage unit, call the efficiency curve of the electric boiler under different load rates, calculate the effective thermal output power after electrothermal conversion efficiency correction for each time period, and form a time period thermal power data sequence.

[0049] Electric heating device type: High-pressure electrode type electric boiler;

[0050] Efficiency curve source: Load rate-efficiency measured curve provided by the electric boiler manufacturer;

[0051] Calculation logic: Periodic thermal power = Input electrical power × Electrothermal conversion efficiency at the corresponding load rate. The periodic thermal power sequence serves as the input for subsequent thermodynamic simulations.

[0052] S3: Set the parameters of the thermal storage system;

[0053] The thermal storage system parameters are a set of engineering design parameters that describe the geometry, materials, and operational boundaries of the thermal storage device.

[0054] The specific method for setting the parameters of the thermal storage system is as follows: input the design parameters such as the geometric dimensions, material properties, thermal insulation performance, and fluid interface configuration of the thermal storage device.

[0055] For example, when setting parameters for a thermal storage system: input the design parameters for a 10,000 m³ hot water storage tank, including the tank diameter of 30 m, height of 15 m, tank material of carbon steel, insulation layer of 50 mm thick aluminum silicate material, specifications and location of fluid interfaces, and other thermal storage system parameters.

[0056] S4: Use time-period thermal power data to simulate the thermodynamic state of the thermal storage medium and generate medium temperature field distribution data;

[0057] The heat storage medium is hot water, provided by the circulating water system of the power plant's heating system, used as a heat energy carrier to absorb, retain, and release heat during the heat storage process. The medium temperature field distribution data is a dataset of the temperature distribution of the heat storage medium in the spatial and temporal dimensions during the heat storage process.

[0058] S5: Dynamic heat loss analysis is performed on the temperature field distribution data using the parameters of the thermal storage system to generate thermodynamic characteristic curves of the thermal storage process, such as... Figure 3 As shown, the heat loss pattern is as follows: the stored heat capacity decreases from 100% to 92.7% (100% - 7.3%) after 8 hours. The curve is slightly faster in the early stage and flattened in the later stage, which is consistent with the thermodynamic characteristics of the heat storage device.

[0059] Methods for calculating heat loss:

[0060] Using the lumped parameter method, and considering the tank structure and environmental conditions, the calculation model is as follows: Where K is the overall heat transfer coefficient; A is the heat dissipation area of ​​the storage tank; Let t be the average temperature of the medium at time t; The ambient temperature.

[0061] The dynamic heat loss analysis calculates the heat loss process over time during thermal storage. The thermal storage process thermodynamic characteristic curve describes the dynamic performance of stored heat, temperature, or available energy over time, characterizing the energy storage and attenuation characteristics of the thermal storage system under real-world operating conditions. For example, the effective heat storage capacity of this tank decreased by 7.3% over 8 hours, and the thermodynamic characteristic curve shows a maximum saturation pressure of 0.23 MPa.

[0062] S6: Verify the pressure-bearing performance of the thermal storage device based on the thermodynamic characteristic curve.

[0063] The pressure bearing performance verification is a process of verifying whether the structural strength of the storage tank meets safety standards based on the highest temperature and pressure in the thermodynamic characteristic curve of the thermal storage process, and stress-pressure comparison is performed according to the pressure vessel design standards.

[0064] Based on the thermodynamic characteristic curve of the thermal storage process generated in step S5, the highest operating temperature (125℃) and the corresponding saturation pressure (0.23MPa) are extracted. The maximum principal stress of the tank body is calculated according to the pressure vessel design standards, and the design wall thickness is verified to meet the requirements. Figure 4 As shown, the design check point (125℃, 0.23MPa) is located within the range, and the structural strength meets the safety specifications.

[0065] Through the implementation of this embodiment, the thermal power plant successfully utilized off-peak electricity for large-capacity hot water energy storage, accurately obtained the thermodynamic characteristic data of the heat storage medium, ensured the structural safety of the heat storage device, provided a reliable basis for the subsequent operation of the heating system, and also achieved effective absorption of off-peak electricity, thus improving energy utilization efficiency.

[0066] An apparatus utilizing the above-described heating method includes:

[0067] The data partitioning unit is used to partition the off-peak electricity storage window data into a time-power matrix to obtain thermal storage period units; the time-power matrix is ​​a data structure that discretizes the off-peak electricity storage window in two dimensions according to time and expected input power; the thermal storage period unit is the smallest simulated time segment in the time-power matrix that has a definite start and end time and constant or variable power input characteristics.

[0068] An efficiency calculation unit, connected to the data partitioning unit, is used to calculate the electrothermal conversion efficiency of the thermal storage period unit to obtain the period thermal power data. The electrothermal conversion efficiency is the proportion of input electrical energy converted into effective thermal energy by the electric heating device within a set thermal storage period unit. The period thermal power data is the effective thermal input power sequence within each thermal storage period unit after correction for electrothermal conversion efficiency.

[0069] The parameter setting unit is used to set and store the parameters of the thermal storage system;

[0070] The thermodynamic simulation unit is connected to the efficiency calculation unit and the parameter setting unit respectively, and is used to simulate the thermodynamic state of the thermal storage medium using the time period thermal power data and thermal storage system parameters to generate medium temperature field distribution data.

[0071] The heat loss analysis unit is connected to the parameter setting unit and the thermodynamic simulation unit respectively, and is used to perform dynamic heat loss analysis on the temperature field distribution data through the parameters of the thermal storage system, and generate the thermodynamic characteristic curve of the thermal storage process.

[0072] The pressure-bearing verification unit is connected to the heat loss analysis unit and is used to verify the pressure-bearing performance of the thermal storage device based on the thermodynamic characteristic curve.

[0073] The pressure-bearing performance verification method of the pressure-bearing verification unit is as follows: based on the highest temperature and pressure in the thermodynamic characteristic curve of the thermal storage process, verify whether the structural strength of the storage tank meets the safety specifications.

[0074] The above description is merely a specific embodiment of the present invention. Various examples and illustrations do not constitute a limitation on the substantive content of the present invention. Those skilled in the art can modify or transform the specific embodiments described above after reading the specification without departing from the essence and scope of the invention.

Claims

1. A method for large-capacity heating in a thermal power plant based on hot water energy storage and off-peak electricity utilization, characterized in that: Includes the following steps: S1: Divide the off-peak electricity storage window data into time-power matrix to obtain thermal storage period units; the time-power matrix is ​​a data structure that discretizes the off-peak electricity storage window in two dimensions according to time and expected input power; The thermal storage period unit is the smallest simulated time segment in the time-power matrix that has a definite start and end time and constant or variable electrical power input characteristics; S2: Calculate the electrothermal conversion efficiency of the thermal storage time unit to obtain the time period thermal power data; S3: Set the parameters of the thermal storage system; S4: Use the thermal power data of the time period to simulate the thermodynamic state of the thermal storage medium and generate medium temperature field distribution data; S5: Perform dynamic heat loss analysis on the temperature field distribution data using the parameters of the thermal storage system to generate a thermal characteristic curve of the thermal storage process; S6: Verify the pressure-bearing performance of the thermal storage device based on the aforementioned thermodynamic characteristic curve.

2. The method for large-capacity heating in a thermal power plant based on hot water energy storage and off-peak electricity utilization according to claim 1, characterized in that: In step S1, the specific method for dividing the off-peak electricity storage window data into a time-power matrix is ​​as follows: the continuous off-peak electricity storage window is discretized into multiple time period units with clear heat input characteristics according to the time step and power level, and uniformly divided using a fixed time step.

3. The method for large-capacity heating in a thermal power plant based on hot water energy storage and off-peak electricity utilization according to claim 1, characterized in that: In step S2, the electrothermal conversion efficiency is the proportion of input electrical energy converted into effective thermal energy by the electric heating device within a set thermal storage period unit. The time period thermal power data is the effective thermal input power sequence within each thermal storage time period unit after correction for electrothermal conversion efficiency. Calculate the thermal power data for each time period: For each thermal storage unit, call the efficiency curve of the electric boiler under different load rates, calculate the effective thermal output power after electrothermal conversion efficiency correction for each time period, and form a time period thermal power data sequence.

4. The method for large-capacity heating in a thermal power plant based on hot water energy storage and off-peak electricity utilization according to claim 1, characterized in that: In step S3, the thermal storage system parameters are a set of engineering design parameters that describe the geometry, materials, and operating boundaries of the thermal storage device.

5. The method for large-capacity heating in a thermal power plant based on hot water energy storage and off-peak electricity utilization according to claim 1, characterized in that: In step S4, The heat storage medium is hot water, which is provided by the circulating water system of the heating system of the thermal power plant. The medium temperature field distribution data is a dataset of the temperature distribution of the thermal storage medium in the spatial and temporal dimensions during the thermal storage process.

6. The method for large-capacity heating in a thermal power plant based on hot water energy storage and off-peak electricity utilization according to claim 1, characterized in that: In step S5, the specific method for performing dynamic heat loss analysis on the temperature field distribution data through the parameters of the thermal storage system is as follows: the temperature field is coupled with the tank wall structure and ambient temperature, the heat loss per unit time is calculated and integrated to obtain the effective heat storage attenuation curve, and the overall heat loss is quickly estimated based on the lumped parameter method.

7. The method for large-capacity heating in a thermal power plant based on hot water energy storage and off-peak electricity utilization according to claim 1, characterized in that: In step S6, the pressure bearing performance verification is based on the highest temperature and pressure in the thermodynamic characteristic curve of the thermal storage process to verify whether the structural strength of the storage tank meets the safety specifications.

8. An apparatus utilizing the heating method according to any one of claims 1-7, characterized in that: include: The data partitioning unit is used to partition the off-peak electricity storage window data into a time-power matrix to obtain thermal storage period units; the time-power matrix is ​​a data structure that discretizes the off-peak electricity storage window in two dimensions according to time and expected input power; the thermal storage period unit is the smallest simulated time segment in the time-power matrix that has a definite start and end time and constant or variable power input characteristics. An efficiency calculation unit, connected to the data partitioning unit, is used to calculate the electrothermal conversion efficiency of the thermal storage period unit to obtain the thermal power data of the period; the electrothermal conversion efficiency is the proportion of input electrical energy converted into effective thermal energy by the electric heating device within a set thermal storage period unit. The time period thermal power data is the effective thermal input power sequence within each thermal storage time period unit after correction for electrothermal conversion efficiency. The parameter setting unit is used to set and store the parameters of the thermal storage system; The thermodynamic simulation unit is connected to the efficiency calculation unit and the parameter setting unit respectively, and is used to simulate the thermodynamic state of the thermal storage medium using the time period thermal power data and thermal storage system parameters to generate medium temperature field distribution data. The heat loss analysis unit is connected to the parameter setting unit and the thermodynamic simulation unit respectively, and is used to perform dynamic heat loss analysis on the temperature field distribution data through the parameters of the thermal storage system, and generate the thermodynamic characteristic curve of the thermal storage process. The pressure-bearing verification unit is connected to the heat loss analysis unit and is used to verify the pressure-bearing performance of the thermal storage device based on the thermodynamic characteristic curve.

9. The large-capacity heating device for thermal power plants based on hot water energy storage and off-peak electricity utilization according to claim 8, characterized in that: The pressure-bearing performance verification method of the pressure-bearing verification unit is as follows: based on the highest temperature and pressure in the thermodynamic characteristic curve of the thermal storage process, verify whether the structural strength of the storage tank meets the safety specifications.

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