A method and device for optimizing the structure of a thermoelectric power generation module

Abstract

The present application provides a method and device for optimizing the design of a thermoelectric power generation module structure, which belongs to the field of optimizing the design of thermoelectric power generation module structures. The method includes: obtaining the air flow rate and natural gas flow rate of the gas delivery pipeline; calculating the total heat released during the combustion process based on the air flow rate and natural gas flow rate, and calculating the flue gas flow rate and flue gas temperature of the thermoelectric power generation module based on the total heat; using the flue gas flow rate and flue gas temperature as boundary conditions to predict the longitudinal temperature distribution of the thermoelectric power generation module; determining the material of the thermoelectric module based on the longitudinal temperature distribution; calculating the number of thermoelectric modules based on the longitudinal temperature distribution; determining the boundary size information of the collector based on the total heat of the collector; using the boundary size information as the size constraint, and using the flue gas flow rate and flue gas temperature as the environmental boundary, to calculate the geometric information of multiple ribs. The present application can achieve comprehensive optimization of the structure of the thermoelectric power generation module and improve the power generation efficiency and performance of the thermoelectric power generation module.

Description

Technical Field

[0001] The present application relates to the technical field of thermoelectric power generation module structure optimization design, and in particular to a thermoelectric power generation module structure optimization design method and device. Background Art

[0002] With the development of science and technology, the research and application of thermoelectric power generation technology continues to advance. In practical application scenarios, such as industrial production processes that generate a large amount of waste heat and automobile engine exhaust that carries a large amount of waste heat, if this waste heat can be effectively utilized, it can not only improve energy efficiency but also reduce environmental pollution. As the core component for thermoelectric power generation, optimizing the performance and structure of the thermoelectric power generation module is crucial to improving power generation efficiency. Currently, the market demand for efficient and stable thermoelectric power generation equipment is constantly increasing, which has promoted the research progress of the structural optimization design of thermoelectric power generation modules.

[0003] The existing method for optimizing the design of the thermoelectric power generation module structure mainly adopts two methods. The first method is simulation, that is, establishing a model of the thermoelectric power generation module structure through simulation, inputting initial parameters into the model, simulating the heat-electricity conversion process, and then simulating the working conditions of the thermoelectric power generation module, and adjusting the structure of the thermoelectric power generation module according to the working conditions; the second method is numerical calculation, which is based on the working temperature conditions of the thermoelectric power generation module. After ignoring certain variables that make the calculation complicated, the numerical formula is used to calculate and solve, and the design parameters of the internal structure of the thermoelectric power generation module are obtained.

[0004] However, both approaches share a common problem: the input variable for structural design is the waste heat gas itself. Under these conditions, existing technologies, whether simulation or numerical calculation, require the addition of an intermediate variable detection process in the actual working environment to determine the state of the waste gas after combustion. Determining the initial conditions for structural design through testing involves numerous interfering factors, which can easily lead to inaccurate test results and, in turn, reduce the accuracy of the structural design. Summary of the Invention

[0005] In view of this, the present application provides a method and device for optimizing the design of a thermoelectric power generation module structure, so as to achieve a fast and accurate optimization design of the thermoelectric power generation module structure.

[0006] Specifically, this application is implemented through the following technical solutions:

[0007] In a first aspect, the present application provides a method for optimizing the structure of a thermoelectric power generation module, the method comprising:

[0008] Obtaining the air flow rate and natural gas flow rate injected into the gas transmission pipeline;

[0009] Calculating the total heat released during the combustion process based on the air flow rate and the natural gas flow rate, and calculating the flue gas flow rate and flue gas temperature of the thermoelectric power generation module based on the total heat;

[0010] The flue gas flow rate and the flue gas temperature are used as boundary conditions to predict the longitudinal temperature distribution from the hot end to the cold end of the thermoelectric power generation module; wherein, the flue gas temperature is used as an initial condition, and the flow path of the flue gas is simulated according to the flue gas flow rate and the structural composition of the thermoelectric power generation module;

[0011] Determining the material of the thermoelectric module according to the endpoint temperature values in the longitudinal temperature distribution;

[0012] Calculating the number of thermoelectric modules according to the longitudinal temperature distribution situation;

[0013] Calculating the total amount of heat collected by the collector based on the number and material of the thermoelectric modules, and determining boundary size information of the collector based on the total amount of heat;

[0014] The geometric information of the plurality of ribs is calculated using the boundary size information as a size constraint and the flue gas flow rate and the flue gas temperature as an environmental boundary.

[0015] A second aspect of the present application provides a device for optimizing the structure of a thermoelectric power generation module, the device comprising an acquisition module, a calculation module, a prediction module, and a determination module;

[0016] Wherein, the acquisition module is used to obtain the air flow rate and natural gas flow rate injected into the gas delivery pipeline;

[0017] The calculation module is used to calculate the total heat released during the combustion process based on the air flow rate and the natural gas flow rate, and calculate the flue gas flow rate and flue gas temperature of the thermoelectric power generation module based on the total heat;

[0018] The prediction module is configured to use the flue gas flow rate and the flue gas temperature as boundary conditions to predict the longitudinal temperature distribution from the hot end to the cold end of the thermoelectric power generation module; wherein, the flue gas temperature is used as an initial condition, and the flow path of the flue gas is simulated according to the flue gas flow rate and the structural composition of the thermoelectric power generation module;

[0019] The determining module is configured to determine the material of the thermoelectric module according to the endpoint temperature values in the longitudinal temperature distribution situation;

[0020] The calculation module is further configured to calculate the number of the thermoelectric modules according to the longitudinal temperature distribution situation;

[0021] The determination module is further configured to calculate the total amount of heat collected by the collector based on the number and material of the thermoelectric modules, and determine boundary size information of the collector based on the total amount of heat;

[0022] The calculation module is further configured to calculate geometric information of a plurality of rib columns using the boundary size information as a size constraint and the flue gas flow rate and the flue gas temperature as environmental boundaries.

[0023] The present application provides a method and device for optimizing the structure of a thermoelectric power generation module, which uses a numerical method to optimize the structure of the thermoelectric power generation module. In the existing numerical calculation method, the input condition used by the design method provided by the present application is the air and natural gas flow rate before input to the burner, that is, before combustion. This information is the initial variable of combustion control, that is, it is controlled by the user and can be accurately and quickly obtained. Based on the accurate acquisition of the initial variables, the present application considers the pipeline for transmitting air and natural gas, the burner and the thermoelectric power generation module as a whole, and uses the gas flow rate as an intermediate variable. Through numerical analysis of the transmission and combustion process, the waste heat gas that can be obtained based on the initial variables is predicted. According to the predicted results, the corresponding thermoelectric power generation module structure is accurately designed. In other words, the design method provided by the present invention has the air and natural gas flow rates input before combustion as input variables, and the output variables are the structural parameters of the thermoelectric power generation module. The core lies in the direct derivation of the type and mass flow rate of the combustion products from the input flow rate through numerical modeling of the combustion chemical reaction, without relying on actual detection of the intermediate variables. Specifically, based on the chemical equation for complete methane combustion, combined with the air composition ratio (21% oxygen, 79% nitrogen) and the excess air coefficient, the mass flow rates of carbon dioxide, water vapor, residual oxygen, and nitrogen can be theoretically calculated, thereby obtaining the flue gas flow rate and temperature. The use of numerical calculations significantly reduces the computational complexity of simulations and simplifies the structural optimization design process. Furthermore, the pre-placement of initial variables enables the design of the thermoelectric power generation module structure with more accurate input parameters, improving design accuracy. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 Flowchart of Example 1 of the structure optimization design method for thermoelectric power generation module provided in this application;

[0025] Figure 2 This is a structural diagram of the thermoelectric power generation module shown in this application;

[0026] Figure 3 This is a schematic diagram of the structure of the second embodiment of the device for optimizing the structure of the thermoelectric power generation module provided by this application;

[0027] Description of reference numerals:

[0028] 1: Gas inlet; 2: Burner; 3: Thermoelectric module; 4: Collector; 5: Water-cooled heat exchanger; 6: Clamping plate. DETAILED DESCRIPTION

[0029] Exemplary embodiments are described in detail herein, with examples illustrated in the accompanying drawings. When the following description refers to the drawings, identical numerals in different drawings represent identical or similar elements unless otherwise indicated. The embodiments described in the following exemplary embodiments are not intended to represent all embodiments consistent with this application.

[0030] The terms used in this application are for the purpose of describing specific embodiments only and are not intended to limit this application. The singular forms "a," "the," and "the" used in this application are also intended to include the plural forms unless the context clearly indicates otherwise. It should also be understood that the term "and / or" as used herein refers to and includes any or all possible combinations of one or more of the associated listed items.

[0031] It should be understood that although the terms first, second, third, etc. may be used in this application to describe various information, such information should not be limited to these terms. These terms are only used to distinguish information of the same type from each other. For example, without departing from the scope of this application, first information may also be referred to as second information, and similarly, second information may also be referred to as first information. Depending on the context, the word "if" as used herein may be interpreted as "at the time of" or "when" or "in response to determining".

[0032] Specific embodiments are given below to introduce the technical solutions of the present application in detail.

[0033] Example 1:

[0034] Figure 1 This is a flow chart of the first embodiment of the thermoelectric power generation module structure optimization design method provided by this application. Please refer to Figure 1 The method provided in this embodiment may include:

[0035] S101. Obtain the air flow rate and natural gas flow rate injected into the gas transmission pipeline.

[0036] The thermoelectric power generation module includes a gas delivery pipeline, one end of which is a gas inlet 1, and the other end is connected to a burner 2. The burner 2 is provided with a waste heat gas outlet, and the waste heat gas outlet is connected to the thermoelectric power generation module; the thermoelectric power generation module is provided with a plurality of thermoelectric modules 3 stacked on each other, and a collector 4 is provided under the thermoelectric module, and a plurality of ribs are distributed in rows and columns on the surface of the collector.

[0037] Figure 2 For the structural diagram of the thermoelectric power generation module shown in this application, please refer to Figure 2It should be noted that the thermoelectric power generation module is a device that uses temperature difference to generate electrical energy. The basic principle is based on the Seebeck effect, that is, two different conductors or semiconductors form a circuit. When the temperatures of the two contact points are different, an electromotive force will be generated in the circuit, thereby generating current. In this application, it generates electricity by receiving the waste heat gas discharged by the burner and using the temperature difference between the hot end (the end with a relatively high working environment temperature) and the cold end (the end with a relatively low working environment temperature). The thermoelectric module is the core component of the thermoelectric power generation module. It is generally made of thermoelectric materials. It can directly convert thermal energy into electrical energy. When there is a temperature difference between the two ends of the thermoelectric module, electrons will diffuse from the high-temperature end to the low-temperature end, thereby forming a current in the circuit. Among them, multiple thermoelectric modules stacked on each other can increase the efficiency and amount of power generation.

[0038] It should be noted that the heat collector 4 is typically located below the stacked thermoelectric modules 3. It collects heat from the exhaust gases emitted by the burners, raising the temperature at the hot end of the thermoelectric modules and enhancing the thermoelectric power generation effect. Its surface is decorated with multiple ribs arranged in rows and columns to increase the contact area with the exhaust gases and more efficiently absorb heat. The larger the rib surface area, the wider the contact area with the exhaust gases, allowing for more heat absorption. This improves the heat collection efficiency of the heat collector and ultimately enhances the power generation capacity of the thermoelectric modules.

[0039] It should also be noted that the thermoelectric power generation module also includes a water-cooled heat exchanger 5 and a clamping plate 6, wherein the water-cooled heat exchanger 5 absorbs heat through the circulating water, reduces the temperature of the thermoelectric power generation module, and ensures that it operates stably within an appropriate operating temperature range. The thermoelectric power generation module contains many components such as multiple stacked thermoelectric modules 3, a collector 4 below, and ribs on the surface. During actual operation, these components may be displaced or loosened due to factors such as vibration, thermal expansion and contraction, affecting the structural stability and performance of the thermoelectric power generation module. The clamping plate can tightly fix the various components together and provide a clamping force to ensure that the above components are tightly connected.

[0040] Specifically, air and natural gas flow rates can be measured by installing flow rate sensors at the inlet of the gas transmission pipeline. There are various types of flow rate sensors, such as ultrasonic sensors, which calculate flow velocity by measuring the propagation time difference of ultrasonic waves in the airflow; and thermal sensors, which use the heat removal property of gas flow to measure flow rate. As another optional embodiment, a combustion control program can be obtained and the air and natural gas flow rates can be determined based on the control flow rates in the program.

[0041] S102: Calculate the total heat released during the combustion process based on the air flow rate and the natural gas flow rate, and calculate the flue gas flow rate and flue gas temperature of the thermoelectric power generation module based on the total heat.

[0042] It should be noted that the main component of natural gas is methane (CH4), which undergoes combustion reaction with oxygen in the air. The chemical equation is: . The amount of oxygen involved in the reaction can be determined based on the air flow rate, and the amount of methane can be known by combining it with the natural gas flow rate. Based on the proportional relationship of the amounts of substances in the chemical reaction, the amount of flue gas components such as carbon dioxide and water vapor generated after combustion can be calculated. As an optional embodiment, if the oxygen in the air accounts for approximately 21% by volume, the actual amount of air required is in a multiple relationship with the theoretical value. After the combustion produces residual substances, the flue gas will carry away the heat generated by the combustion, which is then transmitted to the thermoelectric power generation module for converting heat energy into electrical energy.

[0043] Specifically, the total heat released during the combustion process is calculated based on the air flow rate and the natural gas flow rate, and the flue gas flow rate and flue gas temperature of the thermoelectric power generation module are calculated based on the total heat, including:

[0044] (1) Calculate the total mass flow rate of the combustion gas after mixing the air flow rate and the natural gas flow rate.

[0045] It should be noted that the calculation of the total mass flow rate of the combustion gas after the air flow rate and the natural gas flow rate are mixed includes:

[0046] (i) determining a plurality of post-combustion products based on the mixed post-combustion gas.

[0047] It should be noted that when natural gas (mainly methane) and air (mainly nitrogen and oxygen) burn in a burner, the degree of completeness of combustion may vary at different combustion temperatures, but in general, the products of complete combustion are carbon dioxide, water, nitrogen in the air that does not participate in the reaction, and remaining oxygen if there is excess air.

[0048] (ii) Calculate the mass flow rate of each product.

[0049] Specifically, assuming the flow rate of natural gas is (L / s), the actual air flow rate is (L / s), determine the molar mass (g / mol) of each product, and calculate the mass flow rate based on the product of the molar mass and the corresponding molar flow rate. The molar mass is determined by the product type. For each product, the molar mass of carbon dioxide is 44 g / mol, the molar mass of water is 18 g / mol, the molar mass of oxygen is 32 g / mol, and the molar mass of nitrogen is 28 g / mol.

[0050] Furthermore, the natural gas flow rate and air flow rate are converted to the corresponding molar flow rate. Since the input natural gas flow rate and air flow rate are volume flow rates, the conversion reference quantity under standard conditions is 22.4L / mol. The oxygen content in air is 21%, so the molar flow rate is the ratio of the volume flow rate to 22.4, so: , where the unit of molar flow is mol / s. Based on this, since according to the chemical equation, 1 mol of methane requires 2 mol of oxygen for complete combustion, the molar flow of the remaining oxygen is calculated as , where 0.21 is the proportion of oxygen in the air, 2 is the multiple relationship between oxygen and methane in the chemical relationship, and 22.4 is the conversion between volume flow and molar flow under standard conditions; the excess air coefficient is determined by the ratio of the molar flow of natural gas to the molar flow of oxygen in the air. .

[0051] Calculate the molar flow rate of each product. From the chemical formula, we know that the molar flow rate of carbon dioxide is equal to the molar flow rate of methane. , the molar flow rate of water is equal to twice the molar flow rate of methane The molar flow rate of nitrogen is the product of the molar flow rate of air and the proportion of unreacted nitrogen in the air. , of which the oxygen content in the air accounts for 21% and the nitrogen accounts for approximately 79%.

[0052] The product of the molar flow rate and the molar mass is determined as the mass flow rate (g / s). The molar flow rates of the remaining oxygen, carbon dioxide, water, and nitrogen calculated according to the above steps are multiplied by their corresponding molar masses to obtain the mass flow rate: 、 、 and .

[0053] (iii) Calculate the total mass flow rate based on the mass flow rates of the individual products.

[0054] Add the mass flow rates of the above products to obtain the total mass flow rate of the mixed combustion gas (g / s):

[0055] .

[0056] (2) Calculate the total heat released by the natural gas combustion based on the product of the natural gas flow rate and the standard combustion enthalpy change.

[0057] It should be noted that, combined with the above chemical equation, under standard conditions, each mole of methane will release a certain amount of heat when it is completely burned, which is called the standard combustion enthalpy change. (kJ / mol).

[0058] The molar flow rate of natural gas is calculated based on the natural gas flow rate, and the molar flow rate of carbon dioxide is calculated based on the molar flow rate of natural gas and the chemical reaction formula of natural gas combustion. Referring to the molar flow rate of carbon dioxide described in step (1), it can be seen that the molar flow rate of carbon dioxide is equal to the molar flow rate of methane. The calculation process has been derived in the previous article and will not be elaborated here.

[0059] The total heat (in kJ / s) is calculated by multiplying the molar flow rate of carbon dioxide by the standard combustion enthalpy change.

[0060] In specific implementation, the standard combustion enthalpy change of methane is known (generating water vapor), then the total heat released by natural gas combustion per unit time is .

[0061] (3) Calculating a temperature change value based on a ratio of the total heat amount to a product of the total mass flow rate and the mixed specific heat capacity.

[0062] It should be noted that, before calculating the temperature change value based on the ratio of the total heat and the product of the total mass flow and the mixed specific heat capacity, the method further includes:

[0063] (i) Determine the specific heat capacity weights of the individual products based on the excess air level of the burner.

[0064] It should be noted that the weight of specific heat capacity is generally determined solely by the excess air factor. The specific heat capacity of different products is affected by the degree of excess air in the burner. This excess air level changes the ratio of the various components in the combustion products, which in turn affects the proportion of each product in the gas mixture.

[0065] Furthermore, it is known that at the combustion temperature required by the burner, the specific heat capacities (kJ / (kg·K)) of each component are 1.0 for carbon dioxide, 1.8 for water, 0.9 for oxygen, and 0.75 for nitrogen. The excess air coefficient can be used to determine the amount of excess oxygen, and thus the mass flow rate of each remaining product. The specific heat capacity weight of each product is calculated based on the natural gas flow rate or air flow coefficient in the mass flow rate. Because different excess air levels will cause the proportion of each product to change, the specific heat capacity weights corresponding to different combustion conditions (affected by the excess air level) also vary.

[0066] (ii) calculating a weighted sum of the specific heat capacities of the products based on the specific heat capacity weights to obtain a mixed specific heat capacity.

[0067] Specifically, the mixing specific heat capacity (KJ / (kg·K)) is as follows:

[0068] .

[0069] Based on the calculated mixing specific heat capacity, calculate the temperature change (K):

[0070] ;

[0071] in, is the total heat released by natural gas combustion, calculated in step (2), in KJ / s, is the total mass flow rate, calculated in step (1), in g / s, is the mixing specific heat capacity, the unit is KJ / (kg·K).

[0072] Specifically, combined with the previous calculation results, the numerical calculation formula can be obtained:

[0073] .

[0074] in, is the flow rate of natural gas, is the flow rate of air.

[0075] (4) Calculating the flue gas temperature based on the sum of the temperature change value and the initial temperature value.

[0076] Assuming the initial temperature is 298K, the flue gas temperature is .

[0077] From the foregoing, it can be seen that in the flue gas temperature calculation method provided by the present invention, according to the modeling process of the combustion process mechanism model, during the calculation process, the residual air coefficient is determined by the input natural gas flow rate and air flow rate. When the gas molar mass, the oxygen content in the air, and the chemical reaction formula are constant, the mass flow rate of each product (carbon dioxide, residual oxygen, water, and nitrogen) is only affected by the input natural gas flow rate and air flow rate, and other calculated quantities are determined. Therefore, it can be seen that the coefficients of the natural gas flow rate and air flow rate in the mass flow rate are also determined. Therefore, the value of the mixed specific heat capacity is also determined. Therefore, it can be seen that the denominator of the temperature change value (the product of the total mass flow rate and the mixed specific heat capacity) is only affected by the input natural gas flow rate and air flow rate. The numerical values of other variables can be obtained according to the derivation process. Furthermore, the conversion factor (22.4) from volumetric flow rate to molar flow rate remains constant, as does the standard combustion enthalpy change. Based on this, the product of the molar flow rate and the standard combustion enthalpy change is affected only by the input natural gas flow rate and air flow rate. Therefore, the numerator of the temperature change calculation formula is also affected only by the input natural gas flow rate and air flow rate, while the other variables can be numerically derived based on the derivation process. In summary, the method provided by the present invention only requires the input natural gas flow rate and air flow rate to calculate the corresponding temperature change value according to the above numerical relationship, without the need for repeated derivation of the intermediate process.

[0078] It should also be noted that after obtaining the flue gas temperature, the method provided by the present invention also includes calculating the flue gas flow rate. Specifically, the natural gas flow rate and the air flow rate are converted into corresponding molar flow rates, and the molar flow rate of the remaining oxygen and the molar flow rate of each other product are calculated based on the molar flow rate; the mass flow rate of each product is calculated by multiplying the molar flow rate of the remaining oxygen and the molar flow rate of each other product with the molar mass of the corresponding substance; and the total mass flow rate is calculated based on the sum of the mass flow rates of all products. The calculation process is consistent with the process of calculating the flue gas temperature and will not be elaborated here. Furthermore, the intake density is calculated based on the natural gas flow rate and the air flow rate; the flue gas density is calculated based on the correlation between the intake density and the flue gas density. Specifically, , unit is kg / m 3 ; At high temperatures: , the unit is still kg / m 3 .

[0079] Finally, the flue gas flow rate is calculated as the ratio of the total mass flow rate to the product of the flue gas density and the cross-sectional area of the duct.

[0080] ;

[0081] Where A is the cross-sectional area of the pipe, in m 2 ; is the total volume flow rate of the mixed combustion gas, is the flow rate formula, m total is the total mass flow rate in g / s, is the smoke density, in kg / m 3 , it can be seen that the flue gas flow rate is also only related to the natural gas flow rate and the air flow rate.

[0082] S103. Using the flue gas flow rate and the flue gas temperature as boundary conditions, predict the longitudinal temperature distribution from the hot end to the cold end of the thermoelectric power generation module; wherein, using the flue gas temperature as an initial condition, simulate the flow path of the flue gas according to the flue gas flow rate and the structural composition of the thermoelectric power generation module.

[0083] It should be noted that the longitudinal temperature distribution refers to the temperature variation with position in the longitudinal direction from the hot end to the cold end of the thermoelectric power generation module. The hot end of the thermoelectric power generation module is the end that receives heat and is usually in contact with a high-temperature heat source (such as combustion flue gas), resulting in a higher temperature. The cold end of the thermoelectric power generation module is the end that releases heat and is usually in contact with a low-temperature environment or heat sink, resulting in a relatively low temperature.

[0084] Specifically, the flue gas flow rate and the flue gas temperature are used as boundary conditions to predict the longitudinal temperature distribution of the thermoelectric power generation module, including:

[0085] (1) Establish a spatial model with the same size as the thermoelectric power generation module.

[0086] It should be noted that the spatial model described is simply an empty shell model that matches the dimensions (length, width, and height) of the thermoelectric power generation module. It lacks specific internal structures such as thermoelectric modules and thermal collectors and is used solely to simulate the flow and heat transfer of flue gas within a fixed space. Its core function is to predict the basic temperature distribution trend without internal structures by inputting flue gas flow rate and temperature boundary conditions, given the known maximum module geometry. This provides initial thermal field data for the subsequent layout of thermoelectric modules, thermal collectors, and other components.

[0087] Specifically, the spatial model is constructed as follows: Using numerical simulation software (such as the Geometry module in ANSYS Workbench), a three-dimensional hollow shell model is created, with dimensions consistent with the maximum dimensions of the thermoelectric power generation module. This spatial model contains only the gas flow space (i.e., the area where the thermoelectric modules and collectors will be installed) and excludes any internal components. In the Fluent module in ANSYS Workbench, the model inlet is set to a velocity inlet boundary condition (flue gas flow velocity), the outlet to a pressure outlet, and the shell walls to adiabatic boundaries. By solving the continuity, momentum, and energy equations, the temperature distribution caused by the flue gas flow is simulated.

[0088] (2) The flue gas flow rate and the flue gas temperature are used as inputs of the space model to simulate and calculate the longitudinal temperature distribution of the space model. The temperature distribution is the temperature distribution when the thermoelectric power generation module is not designed with ribs.

[0089] It should be noted that simulation calculations can be performed using basic principles of heat transfer and fluid mechanics. Flue gas flow rate affects the intensity of convective heat transfer between the flue gas and the spatial model; faster flow rates increase convective heat transfer. Flue gas temperature is the driving force for heat transfer; higher temperatures result in greater heat transfer to the spatial model. By inputting these boundary conditions into the spatial model and combining them with material thermophysical properties (such as thermal conductivity and specific heat capacity), numerical calculation methods (such as the finite element method and the finite volume method) are used to solve the governing equations for heat transfer and fluid flow, thereby determining the temperature distribution within the module. The temperature distribution described here represents the temperature distribution of the thermoelectric power generation module without the use of ribs, considering only the flue gas flow and heat transfer within the spatial model. In this case, the spatial model contains only the gas flow space and does not consider the impact of the rib structure on flue gas flow and heat transfer. The purpose is to obtain basic temperature distribution data to provide a reference for the subsequent design of the rib structure within the space. This is because the presence of ribs alters the flue gas flow path and increases the contact area between the flue gas and the module, thereby affecting heat transfer efficiency and temperature distribution. In simulations without rib design, we can more clearly understand the temperature variation patterns within the thermoelectric power generation module under simple flue gas flow and spatial boundary conditions, which will help analyze the impact of rib design on overall performance. For example, by comparing the temperature distribution without ribs and with ribs with different parameters, we can evaluate the optimization effect of the rib shape, size, and layout on the temperature field of the thermoelectric power generation module, providing strong data support for the design of rib geometry information. Specifically, the operation of inputting boundary conditions into the spatial model to predict the longitudinal temperature distribution of the thermoelectric power generation module can be referred to the description of the relevant technology and will not be repeated here.

[0090] It should also be noted that the core function of the spatial model is to obtain the basic thermal field distribution without internal structure. Subsequent designs require integrating components such as thermoelectric modules and collectors within this space, and optimizing component parameters through iterative simulation to ensure that the final temperature distribution meets the power generation efficiency requirements. For example, if the empty shell model simulation shows uneven temperature distribution at the hot end, the simulation with the structured model can be repeated by increasing the collector rib density or adjusting the arrangement of the thermoelectric modules until the temperature distribution uniformity meets the requirements.

[0091] S104 : Determine the material of the thermoelectric module according to the endpoint temperature values in the longitudinal temperature distribution.

[0092] It should be noted that in the longitudinal temperature distribution, the maximum temperature value usually occurs at the hot end, which is in contact with high-temperature flue gas and receives a large amount of heat; the minimum temperature value generally occurs at the cold end, which is in contact with the low-temperature environment or heat dissipation device.

[0093] Different thermoelectric materials have different thermoelectric properties and applicable temperature ranges. The performance of thermoelectric materials is usually measured by the thermoelectric figure of merit. The thermoelectric figures of merit of various thermoelectric materials vary in different temperature ranges. Selecting materials with higher thermoelectric figures of merit within the temperature range corresponding to the endpoint temperature values can improve the power generation efficiency of the thermoelectric module. Specifically, the maximum and minimum temperature values are extracted from the longitudinal temperature distribution trend predicted above, and the thermoelectric material is selected based on the two endpoint temperature values. As an optional embodiment, the operating temperature of the thermoelectric material corresponding to the thermoelectric module needs to exceed the maximum and minimum temperature values, that is, the operating temperature range should be larger than the temperature range included in the maximum and minimum temperature values. During this process, if the temperature range spans the applicable range of different materials, it may be necessary to adopt a multi-stage thermoelectric module, that is, use different thermoelectric materials in different temperature ranges to give full play to the advantages of various materials. Specifically, the first layer material is determined according to the minimum temperature value, the temperature range is divided into intervals according to the working temperature of the first layer material, the maximum temperature point corresponding to the first layer material is determined, and the interval division of the first layer material is completed. The maximum temperature point corresponding to the first layer material is used as the new minimum temperature value, and the step of determining the material according to the minimum temperature value is returned.

[0094] S105 , calculating the number of the thermoelectric modules according to the longitudinal temperature distribution situation.

[0095] It should be noted that calculating the number of thermoelectric modules according to the longitudinal temperature distribution situation includes:

[0096] (1) Calculate a distribution curve of the temperature change rate based on the temperature distribution situation, wherein the abscissa of the distribution curve is the coordinate value of the position corresponding to the temperature change rate in the direction of the thermoelectric power generation module, the direction of the thermoelectric power generation module is the direction from the cold end to the hot end of the thermoelectric power generation module, and the ordinate of the distribution curve is the temperature change rate corresponding to the coordinate value.

[0097] It's important to note that the temperature change rate reflects how quickly the temperature changes with position. The temperature change rate can be obtained by taking the derivative of the longitudinal temperature distribution. By calculating the temperature change rate distribution curve, we can gain a more detailed understanding of the temperature variation characteristics within the module. Specifically, based on the previously predicted longitudinal temperature distribution, we obtain the temperature values at each location along the cold-to-hot end of the thermoelectric power generation module. We then use numerical differentiation methods (such as the finite difference method) to calculate the temperature change rate. For discrete temperature data points, we can approximate the temperature change rate by dividing the temperature difference between two adjacent points by the distance between them. The temperature change rate distribution curve is plotted, with the coordinate value of the location corresponding to the temperature change rate in the thermoelectric power generation module as the horizontal axis and the temperature change rate corresponding to the coordinate value as the vertical axis.

[0098] (2) The direction of the thermoelectric power generation module is segmented according to the amplitude change rate of the distribution curve to obtain multiple partitions of the thermoelectric power generation module.

[0099] It's important to note that the amplitude change rate of the distribution curve reflects the temperature change rate. A large amplitude change rate indicates a significant change in the temperature change rate in that region, suggesting a possible change in the module's internal heat transfer characteristics or operating conditions. By analyzing the amplitude change rate of the distribution curve, the thermoelectric power generation module can be divided into distinct regions, each with relatively consistent temperature change characteristics.

[0100] Specifically, the temperature change rate distribution curve is further differentiated to obtain the amplitude change rate, which can also be numerically calculated using the finite difference method. A threshold for the amplitude change rate is set. When the amplitude change rate exceeds the threshold, the position is considered a split point. Based on these split points, the thermoelectric power generation module is segmented from the cold end to the hot end, resulting in multiple partitions.

[0101] (3) Determine the temperature segmentation interval according to the thermoelectric conversion efficiency of a single thermoelectric module.

[0102] It's important to note that the thermoelectric conversion efficiency of a single thermoelectric module is related to its operating temperature, with different temperature ranges corresponding to different thermoelectric conversion efficiencies. By defining temperature partitions, each thermoelectric module can be operated within its optimal operating temperature range, thereby improving the power generation efficiency of the entire thermoelectric power generation module.

[0103] Specifically, through experiments or reference to data, a curve showing the change of thermoelectric conversion efficiency of a selected single thermoelectric module with temperature can be obtained. Then, based on the efficiency-temperature curve, the temperature range can be divided into several intervals, each of which corresponds to a relatively high and stable thermoelectric conversion efficiency.

[0104] (4) Determine the number of thermoelectric modules corresponding to each partition based on the temperature segmentation interval.

[0105] It should be noted that each zone has a different temperature range. The number of thermoelectric modules suitable for placement within each zone can be determined based on the temperature partitions. Specifically, the temperature range of each zone is determined based on the predicted longitudinal temperature distribution. Each zone's temperature range is then compared with the temperature partitions, and the number of thermoelectric modules to be placed within the zone is determined based on the temperature compatibility. For example, if a zone's temperature range spans two temperature partitions, the number of thermoelectric modules can be allocated based on the temperature percentage within these partitions and the thermoelectric conversion efficiency. In other words, each thermoelectric module achieves optimal thermoelectric conversion efficiency within a different temperature range, and this temperature range is used as the temperature partition, for example, 100°C. Assuming the temperature range of zone i is Ti∈[150°C, 350°C], and the temperature partitions are in 100°C increments, the resulting partitions are Ti1∈[150°C, 250°C] and Ti2∈[250°C, 350°C]. Therefore, two thermoelectric modules, or two in total, can be placed within this zone.

[0106] (5) The total number of thermoelectric modules in each partition is taken as the number of the thermoelectric modules.

[0107] It should be noted that the number of thermoelectric modules in each partition is added together to obtain the total number of thermoelectric modules required for the entire thermoelectric power generation module. This ensures that each partition has an appropriate number of thermoelectric modules to fully utilize the temperature distribution inside the module and improve power generation efficiency.

[0108] S106 , calculating the total amount of heat collected by the heat collector according to the number and material of the thermoelectric modules, and determining boundary size information of the heat collector according to the total amount of heat.

[0109] It's important to note that the overall dimensions of the thermoelectric power generation module are known. Based on this, the dimensions of other components, such as the clamping plate, are fixed. Once the number of thermoelectric modules is determined, the thickness is also determined. The remaining dimensions are the collector's boundary dimensions. The thickness is the remaining dimension, while the other boundaries are consistent with the overall dimensions of the thermoelectric power generation module. Thermoelectric modules require heat to be collected by the collector to generate thermoelectric power, and the number of thermoelectric modules affects the total heat requirement. Generally speaking, the more thermoelectric modules there are, the more heat the collector needs to collect to ensure that each module can obtain sufficient heat to maintain thermoelectric power generation. This usually means a larger collector area, and the boundary dimensions must be adjusted accordingly. If the collector boundary dimensions are too small, insufficient heat collection will occur, resulting in inefficient operation of the thermoelectric modules and reduced power generation efficiency. If the dimensions are too large, while the heat requirement can be met, the material cost and equipment size will increase.

[0110] Specifically, the total heat required by the collector can be calculated based on the heat required by a single thermoelectric module and the number of modules. Combining parameters such as the flue gas temperature and flow rate, and using heat transfer principles and relevant formulas, the effective heat transfer area of the collector required to meet the heat requirement can be calculated, thereby determining the collector's boundary dimensions.

[0111] Specifically, step S104 completes the design of a single thermoelectric module, taking into account the Seebeck effect, Peltier effect, and Joule effect in the material field, and comprehensively calculates the thermal information Q of the thermoelectric module. TEM After the number of thermoelectric modules M is designed in step S105, the total heat required to be collected by the collector can be calculated in step S106 based on the heat information of each thermoelectric module and the product of the number of thermoelectric modules. The convective heat transfer coefficient (related to the flow rate) is then calculated based on the principles of heat transfer and fluid mechanics: , and fin efficiency , C and m are constants, k f 、V f,max 、ν f 、P r and Pr w They are thermal conductivity, maximum velocity considering collector rib blocking effect, kinematic viscosity, Prandtl number and Prandtl number under wall temperature, d is the rib diameter, H is the rib height, k HC is the thermal conductivity of the collector bottom surface.

[0112] Finally, according to the formula Calculate the effective heat transfer area A of the collector to meet the heat demand HC1 , where T HC is the surface temperature of the collector bottom, T finalis the flue gas temperature. After determining the area, the shape of the collector must also be considered. For common flat-plate collectors, the length and width can be determined based on the effective heat transfer area. For other shapes, such as circular collectors, the radius and other dimensions must be determined. In addition, the limitations of the boundary dimensions due to factors such as installation space and manufacturing costs must also be considered. HC1 The corresponding length, width and remaining thickness are used as boundary dimension information to determine the length, width and thickness of the collector as the boundary dimensions of the design.

[0113] In this way, by reasonably determining the collector boundary size information, the collector and the thermoelectric module can be better matched, the heat collection and transfer efficiency can be improved, the thermoelectric module can be ensured to work under a suitable temperature difference, and the power generation efficiency and stability of the thermoelectric power generation module can be improved.

[0114] S107 , using the boundary size information as a size constraint, and the flue gas flow rate and the flue gas temperature as environmental boundaries, to calculate geometric information of a plurality of rib columns.

[0115] It's important to note that flue gas velocity and temperature, as environmental boundaries, represent the operating conditions of the ribs. Flue gas velocity influences the intensity of convective heat transfer between the flue gas and the ribs, while flue gas temperature is the driving force for heat transfer. Furthermore, rib geometry includes parameters such as shape (e.g., cylindrical, square), dimensions (e.g., diameter, height, spacing), and layout (e.g., the specific arrangement of rows and columns). This information determines performance, such as the contact area between the ribs and the flue gas and heat exchange efficiency. Specifically, based on the number of thermoelectric modules calculated in the previous steps, the total heat that the collector needs to collect, and the flue gas temperature, flow rate and other parameters, determine the amount of heat exchange that the rib column needs to bear (the determination of the heat exchange amount provides a basis for the subsequent calculation of the rib column size and layout), and then select the appropriate rib column shape according to the shape, size and actual application scenario requirements of the collector (common rib column shapes are cylindrical and square). In order to ensure the regularity of the geometric shape, this application comprehensively considers a variety of commonly used configurations such as cylinders, squares, and triangular prisms, and uses a conventional single variable method to calculate the power generation efficiency under each shape configuration on the basis of certain other design parameters, and finally selects the optimal shape under the current design environment. According to the heat exchange requirements and heat transfer principles, the rib column height is calculated using Newton's cooling law. After determining the rib column height, the diameter (for cylindrical rib columns) or side length (for square rib columns) of the rib column is calculated based on the relationship between the heat exchange area and the collector surface area. For example, the effective heat transfer area A of the collector is known. HC1 , it is planned to arrange n ribs, and the effective heat exchange area covered by the ribs is required to account for the proportion of the collector surface area β, then the heat exchange area of a single rib is β*A HC1 / n.

[0116] In addition, the spacing of the ribs needs to be determined (including the normal spacing of the ribs, that is, the distance between the ribs in the direction perpendicular to the flue gas flow; and the parallel spacing of the ribs, that is, the distance between the ribs in the direction of the flue gas flow). The spacing of the ribs will affect the flow characteristics and heat exchange efficiency of the flue gas. If the spacing is too small, the flue gas flow resistance will increase, which will lead to a decrease in the flue gas flow rate and reduce the overall heat exchange effect; if the spacing is too large, the thermal radiation and convection heat transfer between the ribs will be weakened, and the flue gas heat will not be fully utilized, and the heat distribution on the collector surface will be uneven. Specifically, the appropriate rib spacing can be determined through numerical simulation or experimental research. Finally, under the boundary size constraints of the collector, the layout of the ribs can be further optimized based on the calculated rib size and spacing. Specifically, for the method of calculating the geometric information of the ribs, please refer to the description of the relevant technology and will not be repeated here.

[0117] The method provided in this embodiment predicts the longitudinal temperature distribution trend by establishing a spatial model, and determines the thermoelectric module material based on this to ensure that it works at an appropriate temperature and gives full play to the material performance. At the same time, the number of thermoelectric modules is scientifically calculated and reasonably arranged to improve the conversion efficiency of thermal energy to electrical energy. The collector boundary size and rib column geometry information are optimized to enhance the heat collection and transfer capabilities, so that the thermoelectric module can better utilize heat to generate electricity, and the overall power generation efficiency of the temperature difference power generation module is improved. In addition, when determining the collector boundary size information, factors such as the number of thermoelectric modules, heat demand, installation space and manufacturing cost are comprehensively considered to avoid material waste or poor performance caused by the collector being too large or too small, thereby reducing material costs. By reasonably calculating the number of thermoelectric modules, unnecessary module use is avoided, reducing module costs.

[0118] Example 2:

[0119] Corresponding to the aforementioned embodiment of a method for optimizing the structure of a thermoelectric power generation module, the present application also provides an embodiment of a device for optimizing the structure of a thermoelectric power generation module.

[0120] Figure 3 This is a schematic diagram of the structure of the second embodiment of the thermoelectric power generation module structure optimization design device provided by this application. Figure 3 The device provided in this embodiment includes an acquisition module 310, a calculation module 320, a prediction module 330 and a determination module 340;

[0121] The acquisition module 310 is used to acquire the air flow rate and the natural gas flow rate injected into the gas delivery pipeline;

[0122] The calculation module 320 is used to calculate the total heat released during the combustion process based on the air flow rate and the natural gas flow rate, and calculate the flue gas flow rate and flue gas temperature of the thermoelectric power generation module based on the total heat;

[0123] The prediction module 330 is configured to use the flue gas flow rate and the flue gas temperature as boundary conditions to predict the longitudinal temperature distribution from the hot end to the cold end of the thermoelectric power generation module; wherein, the flue gas temperature is used as an initial condition, and the flow path of the flue gas is simulated according to the flue gas flow rate and the structural composition of the thermoelectric power generation module;

[0124] The determination module 340 is configured to determine the material of the thermoelectric module according to the endpoint temperature values in the longitudinal temperature distribution situation;

[0125] The calculation module 320 is further configured to calculate the number of the thermoelectric modules according to the longitudinal temperature distribution situation;

[0126] The determination module 340 is further configured to calculate the total amount of heat collected by the collector based on the number and material of the thermoelectric modules, and determine boundary size information of the collector based on the total amount of heat;

[0127] The calculation module 320 is further configured to calculate geometric information of a plurality of ribs using the boundary size information as a size constraint and the flue gas flow rate and the flue gas temperature as environmental boundaries.

[0128] The device of this embodiment can be used to perform Figure 1 The steps, specific implementation principles and implementation processes of the method embodiment shown are similar and will not be repeated here.

[0129] The implementation process of the functions and effects of each unit in the above-mentioned device is specifically described in the implementation process of the corresponding steps in the above-mentioned method, and will not be repeated here.

[0130] For the device embodiments, since they basically correspond to the method embodiments, the relevant parts can be referred to the partial description of the method embodiments. The device embodiments described above are merely schematic, wherein the units described as separate components may or may not be physically separated, and the components displayed as units may or may not be physical units, that is, they may be located in one place, or they may be distributed on multiple network units. Some or all of the modules may be selected according to actual needs to achieve the purpose of the present application scheme. A person of ordinary skill in the art can understand and implement it without paying any creative work.

[0131] The above description is only a preferred embodiment of the present application and is not intended to limit the present application. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present application shall be included in the scope of protection of the present application.

Claims

1. A method for optimizing the structure of a thermoelectric power generation module, characterized in that: The method comprises: Obtaining the air flow rate and natural gas flow rate injected into the gas transmission pipeline; Calculating the total heat released during the combustion process based on the air flow rate and the natural gas flow rate, and calculating the flue gas flow rate and flue gas temperature of the thermoelectric power generation module based on the total heat; The flue gas flow rate and the flue gas temperature are used as boundary conditions to predict the longitudinal temperature distribution from the hot end to the cold end of the thermoelectric power generation module; wherein, the flue gas temperature is used as an initial condition, and the flow path of the flue gas is simulated according to the flue gas flow rate and the structural composition of the thermoelectric power generation module; Determining the material of the thermoelectric module according to the endpoint temperature values in the longitudinal temperature distribution; Calculating the number of thermoelectric modules according to the longitudinal temperature distribution situation; Calculating the total amount of heat collected by the collector based on the number and material of the thermoelectric modules, and determining boundary size information of the collector based on the total amount of heat; The geometric information of the plurality of ribs is calculated using the boundary size information as a size constraint and the flue gas flow rate and the flue gas temperature as an environmental boundary.

2. The method according to claim 1, characterized in that The calculating the flue gas temperature of the thermoelectric power generation module includes: Calculating a total mass flow rate of combustion gas after mixing the air flow rate and the natural gas flow rate; calculating a total heat released by the combustion of the natural gas based on the product of the natural gas flow rate and a standard combustion enthalpy change; calculating a temperature change value based on a ratio of the total heat amount to a product of the total mass flow rate and a mixed specific heat capacity; The flue gas temperature is calculated based on the sum of the temperature change value and the initial temperature value.

3. The method according to claim 2, characterized in that The calculating the total mass flow rate of the combustion gas after the air flow rate and the natural gas flow rate are mixed comprises: determining a plurality of post-combustion products based on the mixed post-combustion gas; Calculate the mass flow rate of each product; The total mass flow rate is calculated based on the mass flow rate of each product.

4. The method according to claim 2, characterized in that Before calculating the temperature change value based on the ratio of the total heat and the product of the total mass flow and the mixed specific heat capacity, the method further includes: Determining the specific heat capacity weights of the individual products based on the degree of excess air in the burner; The weighted sum of the specific heat capacities of the products is calculated based on the specific heat capacity weights to obtain the mixed specific heat capacity.

5. The method according to claim 2, characterized in that The numerical calculation formula for the temperature change value is: ； in, is the flow rate of natural gas, in L / s; is the air flow rate in L / s.

6. The method according to claim 3, characterized in that The calculation of the mass flow rate of each product includes: Convert the natural gas flow rate and the air flow rate into corresponding molar flow rates, and calculate the molar flow rate of the remaining oxygen and the molar flow rates of each other product based on the molar flow rates; The mass flow rate of each product is calculated using the product of the molar flow rate of the remaining oxygen and the molar flow rate of each other product and the molar mass of the corresponding substance.

7. The method according to claim 1, characterized in that The calculation process of the flue gas flow rate includes: Calculate the intake air density based on the natural gas flow rate and the air flow rate; Calculating the smoke density based on the correlation between the intake air density and the smoke density; The flue gas flow rate is calculated based on the ratio of the total mass flow rate to the product of the flue gas density and the cross-sectional area of the duct.

8. The method according to claim 1, characterized in that The method of using the flue gas flow rate and the flue gas temperature as boundary conditions to predict the longitudinal temperature distribution of the thermoelectric power generation module includes: Establishing a spatial model with the same size as the thermoelectric power generation module; The flue gas flow rate and the flue gas temperature are used as inputs of the space model to simulate and calculate the longitudinal temperature distribution of the space model. The temperature distribution is the temperature distribution when the thermoelectric power generation module is not designed with ribs.

9. The method according to claim 1, characterized in that Calculating the number of the thermoelectric modules according to the longitudinal temperature distribution situation includes: Calculating a distribution curve of the temperature change rate based on the temperature distribution situation, wherein the abscissa of the distribution curve is the coordinate value of the position corresponding to the temperature change rate in the direction of the thermoelectric power generation module, the direction of the thermoelectric power generation module is the direction from the cold end to the hot end of the thermoelectric power generation module, and the ordinate of the distribution curve is the temperature change rate corresponding to the coordinate value; Performing regional segmentation on the direction of the thermoelectric power generation module according to the amplitude change rate of the distribution curve to obtain multiple partitions of the thermoelectric power generation module; determining a temperature segmentation interval according to the thermoelectric conversion efficiency of a single thermoelectric module; Determining the number of thermoelectric modules corresponding to each partition based on the temperature partition interval; The total number of thermoelectric modules in each partition is taken as the number of thermoelectric modules.

10. A device for optimizing the structure of a thermoelectric power generation module, characterized in that: The device includes an acquisition module, a calculation module, a prediction module and a determination module; Wherein, the acquisition module is used to obtain the air flow rate and natural gas flow rate injected into the gas delivery pipeline; The calculation module is used to calculate the total heat released during the combustion process based on the air flow rate and the natural gas flow rate, and calculate the flue gas flow rate and flue gas temperature of the thermoelectric power generation module based on the total heat; The prediction module is configured to use the flue gas flow rate and the flue gas temperature as boundary conditions to predict the longitudinal temperature distribution from the hot end to the cold end of the thermoelectric power generation module; wherein, the flue gas temperature is used as an initial condition, and the flow path of the flue gas is simulated according to the flue gas flow rate and the structural composition of the thermoelectric power generation module; The determining module is configured to determine the material of the thermoelectric module according to the endpoint temperature values in the longitudinal temperature distribution situation; The calculation module is further configured to calculate the number of the thermoelectric modules according to the longitudinal temperature distribution situation; The determination module is further configured to calculate the total amount of heat collected by the collector based on the number and material of the thermoelectric modules, and determine boundary size information of the collector based on the total amount of heat; The calculation module is further configured to calculate geometric information of a plurality of rib columns using the boundary size information as a size constraint and the flue gas flow rate and the flue gas temperature as environmental boundaries.

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