Gas stove simulation analysis method based on static state and combustion state

Abstract

The invention discloses a gas stove simulation analysis method based on a static state and a combustion state, and relates to the technical field of gas stove design, and the gas stove simulation analysis method comprises the following steps: S1, constructing a static premixing flow model; s2, setting boundary conditions of the static premixing flow model; s3, performing process simulation on the static premixing flow model; obtaining a first simulation result; executing S4 only when the first simulation result reaches a first preset standard, otherwise, executing S2; s4, constructing a combustion state heat transfer model; s5, setting boundary conditions of the combustion state heat transfer model; s6, performing process simulation on the combustion state heat transfer model; obtaining a second simulation result; executing S7 only when the second simulation result reaches a second preset standard, otherwise executing S5; s7, performing proofing verification on the simulation model, and evaluating whether the performance of the sample meets a preset requirement or not; if not, executing S5; and if so, ending the simulation. Compared with the prior art, the working efficiency of the gas stove design simulation test is effectively improved, and the time cost is reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of gas stove design, and in particular to a simulation analysis method for gas stoves based on static and combustion states. Background Art

[0002] A gas cooker is a heating device that achieves stable combustion by premixing gas and air, and can be divided into two categories: atmospheric (partial premixing) and fully premixed according to the combustion method. The entire gas system includes three key processes: ejector mixing, combustion reaction, and heat transfer and mass transfer, involving the multi-form conversion of chemical energy, thermal energy, and kinetic energy. The forms and flow directions of the system energy are diverse and complex. Therefore, in order to reveal the interaction laws between system energies and provide an energy-saving approach for gas stoves, it is necessary to establish an energy flow model of the gas stove system for research.

[0003] However, the complexity of the gas stove structure makes any minor adjustment may significantly affect its overall performance. In the traditional optimization design process, each structural modification requires the manufacture of a new mold for physical testing, which not only results in high time costs but also brings huge financial pressure. For example, the patent document with the publication number CN106547998B provides a method for evaluating the optimization design of a gas cooker and its test system, which can quickly evaluate the combustion conditions, thermal performance, and flue gas emission indexes of the gas cooker without producing the gas cooker entity, so as to improve the design efficiency and technical level of the cooker.

[0004] Nevertheless, simulation itself also faces the challenge of time consumption. Due to the multi-physical field coupling effects involved in gas stoves, such as fluid dynamics, combustion chemistry, heat conduction, and structural strength, establishing a high-precision simulation model requires fine mesh division and strict boundary condition setting. Taking the optimization of the ejector as an example, a single three-dimensional CFD simulation needs to process more than 3 million mesh elements, and the convergence calculation of the combustion chamber pressure field and temperature field usually takes 12 - 18 hours. In addition, during the simulation test of the gas stove, there are two research directions, namely, the simulation of the gas fluid transportation process and the simulation of the flame combustion heat transfer process. Whenever the simulation results deviate from the design goal, it is necessary to repeatedly correct the boundary conditions such as the turbulence intensity and restart the full-process simulation calculation, that is, each time the structure is adjusted and then the simulation is carried out, it consumes a lot of time. How to improve the efficiency of simulation analysis in the gas stove optimization design process has become a key issue. Summary of the Invention

[0005] In view of the problems existing in the prior art, the present invention provides a simulation analysis method for gas stoves based on static and combustion states. Compared with the prior art, it can effectively improve the simulation design efficiency of gas stoves, improve the R & D efficiency of gas stove products, and save the cost consumption in the R & D process.

[0006] The technical solution of the present invention is realized as follows: A simulation analysis method for gas stoves based on static and combustion states, comprising the following steps: S1. Extract the structures of the nozzle, ejector tube, burner head, and burner cap with fire holes in the gas stove to construct a static premixed flow model of the gas stove; perform simplified settings on the static premixed flow model; the static premixed flow model mainly studies the mixing flow characteristics of gas and air in a non-combustion state, focusing on fluid dynamics parameters such as flow field structure, turbulent mixing, pressure distribution, and velocity field. Its core assumption is to only simulate the gaseous mixing process at room temperature.

[0007] S2. Set the boundary conditions of the static premixed flow model, including the primary air intake boundary condition; set the ratio of the inlet air pressure and inlet air mass of the nozzle. S3. Perform process simulation on the static premixed flow model; calculate / extract the first simulation results, including the ejection efficiency of the ejector tube, and the ratio of the outlet gas flow rate and outlet gas mass of the fire hole; only when the first simulation results meet the first preset standard, execute S4, otherwise, continue to execute S2. S4. Construct a combustion state heat transfer model of the gas stove; the combustion state heat transfer model studies chemical reactions, heat release, and heat transfer mechanisms during the combustion process, and is used for refined analysis of combustion efficiency and emission performance. Perform simplified settings on the combustion state heat transfer model. S5. Set the boundary conditions of the combustion state heat transfer model, including the secondary air intake boundary condition; set the ratio of the outlet gas flow rate and the outlet gas mass; at the same time, also set the combustion turbulence intensity and wall temperature. S6. Perform process simulation on the combustion state heat transfer model; calculate / extract the second simulation results; only when the second simulation results meet the second preset standard, execute S7, otherwise, continue to execute S5. S7. Perform proofing verification on the static premixed flow model and the combustion state heat transfer model, and evaluate whether the performance of the proofing sample meets the preset requirements; if not, execute step S5 and readjust the boundary conditions of the combustion state heat transfer model. If it meets, end the simulation analysis. The preset requirements are the working indicators of the final production product. Further, the working indicators can be / including the first preset standard and the second standard.

[0008] This application creatively divides the simulation of the static premixed flow model and the simulation of the combustion state heat transfer model into two stages and conducts them successively. Only when the gas stove passes the simulation of the static premixed flow model and meets the standards and is qualified, stop the iterative optimization of the static premixed flow model, and then perform the iterative optimization of the combustion state heat transfer model. Instead of, as in the prior art, performing cold state simulation and hot state simulation simultaneously, and having to iterate all once the simulation results do not meet the standards. It effectively improves the working efficiency of the design simulation test of the gas stove and greatly reduces the time cost.

[0009] In existing gas stoves, the nozzle includes a nozzle inlet, a nozzle outlet, and a nozzle injection hole; the ejector tube includes an ejector tube inlet and an ejector tube outlet; the gas stove also includes a burner head; the upper end of the burner head is connected to the burner cap; the burner cap is also provided with flame stabilizing holes, and the flame stabilizing holes are arranged on the outer periphery of the burner holes; the gas stove is also provided with an air duct, and the air duct penetrates through the upper and lower ends of the burner head; The nozzle inlet is connected to the connecting gas valve body for receiving gas; the nozzle injection hole is used for introducing primary air intake; the nozzle outlet is communicated with the ejector tube inlet; the ejector tube outlet, the flame stabilizing holes, and the burner holes are all communicated with the inner cavity of the burner head; the primary air intake and the gas form premixed gas in the ejector tube and are sprayed towards the burner head; the premixed gas is ejected and burned from the burner holes; the air duct is used for introducing secondary air intake from bottom to top towards the area of the burner holes; The primary air intake corresponds to the primary air intake boundary conditions; the secondary air intake corresponds to the secondary air intake boundary conditions.

[0010] The primary air intake mainly participates in premixing to ensure an appropriate mixing ratio of gas and air; the secondary air intake supplements oxygen during combustion to prevent incomplete combustion. The two achieve efficient and stable combustion of the gas stove through synergistic effects.

[0011] As a further optimization of the above solution, the primary air intake boundary conditions are the parameters of the static premixed flow model in different regions, including: the pressure at the nozzle inlet is B1 Pa; the pressures at the nozzle injection hole, the ejector tube inlet, and the ejector tube outlet are all B2 Pa; the wall temperatures of the nozzle and the ejector tube are both B3 K; The value range of B1 is 2500 - 3000; the value range of B2 is -5 to 0; the value range of B3 is 300 to 350.

[0012] In fluid mechanics and thermodynamics, the wall refers to the solid boundary of the fluid flow path, such as the inner surface of a pipe, nozzle, or burner. Its functions include restricting fluid flow, transferring heat, and bearing fluid pressure, etc. In a gas stove, the wall temperatures of the nozzle and the ejector tube will affect the preheating effect of the gas and the combustion stability.

[0013] As a further optimization of the above solution, when simulating the gas stove, a standard pot model is also set; In S4, according to the burner cap and the standard pot model, the combustion state heat transfer model is constructed; the combustion state heat transfer model also includes an influence space area formed on the outer peripheral side of the standard pot model; The secondary air intake boundary conditions are the parameters of the combustion state heat transfer model in different regions, including: The pressures of the affected spatial region on the side, top, and bottom surfaces are C1 Pa, C2 Pa, and C3 Pa respectively; the wall temperature of the burner cap is C4 K; the wall temperature of the standard pot model is C5 K; the velocity of the premixed gas of the gas stove at the inlet of the flame hole is C6 m / s; the wall temperature of the secondary air intake is C7 K; the pressure of the secondary air intake at the bottom of the standard pot model is C8 Pa; The value range of C1 is from -0.1 to 0; the value range of C2 is from -0.1 to 0; the value range of C3 is from 0 to 2; the value range of C4 is from 770 to 800; the value range of C5 is from 550 to 575; the value range of C6 is from 0 to 2; the value range of C7 is from 550 to 575; the value range of C8 is from 0 to 0.02.

[0014] As a further optimization of the above solution, in step S7, if the preset requirements are not met, then step S5 is executed to readjust C4, C5, and C7.

[0015] The large space outside the standard pot model refers to the external environmental area where the gas-air mixture and flame propagation occur during the combustion process. In natural convection heat transfer, it refers to the open area where the boundary layer of the fluid (such as air) is not affected by the adjacent wall or flow interference during its flow. Its core feature is the freedom of fluid movement. Even if the geometric space is limited, as long as the boundary layer is not disturbed, it can still be regarded as a "large space". For example, the air area around the gas stove flame that is not blocked by the cookware can be regarded as a large space for analyzing natural convection heat dissipation.

[0016] As a further optimization of the above solution, the simplification in S1 is as follows: The rated gas supply pressure of the gas is the pressure at the inlet of the nozzle; The injection hole of the nozzle is directly connected to the outside, and its boundary condition is the normal temperature and pressure environment; The inlet of the injection pipe is directly connected to the outside, and its boundary condition is the normal temperature and pressure environment; The outlet of the flame hole is directly connected to the outside, and its boundary condition is the normal temperature and pressure environment; The boundary conditions of the nozzle and the walls of the burner head are both constant wall temperature and no-slip.

[0017] In the flow of viscous fluids (such as gas and air), when the fluid contacts the solid wall surface, the tangential velocity of the fluid at the wall surface is consistent with the wall surface movement velocity. If the wall surface is stationary, the fluid velocity at the wall surface is zero, meaning that the fluid will not slide along the wall surface.

[0018] Constant wall temperature means that in the simulation or physical system, the temperature of the solid wall surface is fixed at a certain constant value, which belongs to the fixed temperature type in the thermal boundary conditions.

[0019] As a further optimization of the above solution, the simplification in S4 is as follows: On the same burner cap, the gas components of the gas ejected from each of the fire holes are the same, and the distribution of the fire holes is uniform; On the same burner cap, the outlet gas flow rates of each of the fire holes are the same; When the combustion reaches a steady state, the temperature of the standard pot model does not change, and the boundary conditions of the wall surface of the standard pot model are set to a constant wall temperature and no-slip; The boundary conditions of the influence space region are a normal temperature and normal pressure environment.

[0020] As a further optimization of the above solution, after constructing the static premixed flow model, grid division is performed on the static premixed flow model; among them, grid encryption processing is performed on the nozzle region.

[0021] The premixed cold state model has both a nozzle structure and a chamber structure. The internal structure of the nozzle is extremely small compared to the space of the mixing chamber, and the spatial dimensions of each structure have a large span. Therefore, when dividing the grid, if the grid size is set the same, there will be a situation where the grid at the nozzle is too large or the grid in the chamber is too small, resulting in problems with the calculation results. To avoid this phenomenon, in this article, a body region is set separately for the nozzle structure and other structures. The grid size at the nozzle is set smaller, and the grid in the chamber is set larger, saving the calculation cost while ensuring the accuracy of the calculation results.

[0022] As a further optimization of the above solution, the first preset standard is that the entrainment efficiency is 0.5 - 0.8; the fluid velocity at the fire hole outlet is A1 m / s; the value range of A1 is 0.8 - 1.0; The types of gas burned by the gas stove include natural gas and liquefied petroleum gas; among them, the calculation of the entrainment efficiency of different types of gas is different; When the gas is natural gas, the entrainment efficiency is , that is: ; When the gas is liquefied petroleum gas, the entrainment efficiency is , that is: ; Among them, n represents the mole fraction of the gas, respectively represent oxygen, methane, propane, and butane contained in the gas at the fire hole outlet.

[0023] The combustion of natural gas involves methane, that is ; the combustion of liquefied petroleum gas involves propane and butane, that is and In addition, there are other types of gas, and the calculation of the entrainment efficiency is transformed according to the corresponding chemical combustion formula.

[0024] As a further optimization of the above solution, in S5, during a new round of iteration, the turbulence intensity of the combustion heat transfer model is corrected, that is: ; where represents the turbulence intensity, and ; refers to the Reynolds number.

[0025] The Reynolds number is a dimensionless number that can be used to characterize the fluid flow situation.

[0026] As a further optimization of the above solution, the second simulation result includes the thermal efficiency and thermal load of the gas stove, as well as the CO concentration emitted during combustion; wherein, the thermal efficiency refers to the efficiency of the gas stove to convert the chemical energy of the gas into the effective heat absorption of the standard pot model, and the thermal load refers to the total energy released by the gas stove burning gas per unit time; The second preset standard is that the thermal efficiency reaches or exceeds the preset rated thermal efficiency, the thermal load is within the rated thermal load range, and the CO concentration is less than the set value; The thermal efficiency is calculated as: ; where represents the bottom heat load of the pot body of the standard pot model; represents the side heat load of the pot body of the standard pot model; represents the chemical release heat during combustion. The set value here is a customizable threshold that meets the design requirements. For example, in the domestic standard of gas stoves, the CO concentration generated during combustion is less than 500 ppm.

[0027] Except for the thermal efficiency, the rest of the parameters are automatically simulated and generated by the simulation software.

[0028] Compared with the prior art, the present invention has the following beneficial effects: This application creatively divides the simulation of the static premixed flow model and the simulation of the combustion heat transfer model into two stages and conducts them successively. Only when the simulation of the static premixed flow model of the gas stove meets the standards and is qualified, the iterative optimization of the static premixed flow model is stopped, the ejection efficiency is transmitted to the next stage, and then the iterative optimization of the combustion heat transfer model is carried out. Unlike the prior art, the cold-state simulation and the hot-state simulation are carried out simultaneously, and once the simulation results do not meet the standards, all iterations are required. Compared with the prior art, the operation efficiency of the design simulation test of the gas stove and the accuracy of the simulation are effectively improved, thereby improving the R & D efficiency of the gas stove product, saving the cost consumption in the R & D process, and greatly reducing the time cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 FIG. is a schematic flow chart of a simulation analysis method for a gas stove based on static and combustion states provided by an embodiment of the present invention; Figure 2 FIG. is a sectional view of a partial structure of a gas stove provided by an embodiment of the present invention; Figure 3 FIG. is a schematic diagram of the effect of the static premixed flow model provided by an embodiment of the present invention; Figure 4 FIG. is a schematic diagram of the effect of the combustion heat transfer model provided by an embodiment of the present invention.

[0030] REFERENCE SIGNS: 1. Nozzle inlet; 2. Nozzle outlet; 3. Nozzle ejection hole; 4. Burner head; 5. Flame holes; 6. Flame stabilizing holes; 7. Ejector tube inlet; 8. Ejector tube outlet; 9. Air duct; 10. Primary air intake; 11. Secondary air intake; 12. Premixed gas; 13. Standard pot model; 14. Influence space area. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0031] In order to make the objectives, technical solutions and advantages of the present invention clearer and more understandable, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the scope of protection of the present invention.

[0032] As Figures 1 to 4 shown, this embodiment provides a simulation analysis method for a gas stove based on static and combustion states. The gas stove includes a nozzle, an ejector tube, a burner head 4 and a burner cap. The burner cap is provided with flame holes 5 and flame stabilizing holes 6. A standard pot model 13 is also provided on the gas hood.

[0033] In this embodiment, the nozzle includes a nozzle inlet 1, a nozzle outlet 2, and a nozzle ejector hole 3. The ejector tube includes an ejector tube inlet 7 and an ejector tube outlet 8. The upper end of the burner head 4 is communicated with the burner cap; the flame stabilizing holes 6 are arranged on the outer periphery of the flame holes 5. The gas stove is also provided with an air duct 9, and the air duct 9 penetrates through the upper and lower ends of the burner head 4; The nozzle inlet 1 is connected to the connecting gas valve body for receiving gas; the nozzle ejector hole 3 is used for introducing primary air intake 10; the nozzle outlet 2 is communicated with the ejector tube inlet 7; the ejector tube outlet 8, the flame stabilizing holes 6, and the flame holes 5 are all communicated with the inner cavity of the burner head 4; the primary air intake 10 and the gas form premixed gas 12 in the ejector tube and are sprayed towards the burner head 4; the premixed gas 12 is ejected from the flame holes 5 and burns; the air duct 9 is used for introducing secondary air intake 11 from bottom to top to the area of the flame holes 5; the primary air intake 10 mainly participates in premixing to ensure an appropriate mixing ratio of gas and air; the secondary air intake 11 supplements oxygen during combustion to prevent incomplete combustion. The two achieve efficient and stable combustion of the gas stove through synergistic effects.

[0034] The method includes the following steps: S1. Import the geometric model into ANSYS ICEM to set the area and divide the computational grid, select a suitable turbulent flow model, extract the structure of the gas stove, and construct a static premixed flow model of the gas stove according to the nozzle, ejector tube, burner head 4, and burner cap; after constructing the static premixed flow model, perform grid division on the static premixed flow model; among them, grid encryption is performed on the nozzle area.

[0035] In the premixed cold state model, there are both nozzle structures and chamber structures. The internal structure of the nozzle is extremely small compared to the space of the mixing chamber, and the spatial dimensions of each structure have a large span. Therefore, when dividing the grid, if the grid size is set the same, there will be too large a grid at the nozzle or too small a grid in the chamber, resulting in problems in the calculation results. To avoid this phenomenon, in this paper, separate body areas are set for the nozzle structure and other structures. The grid size at the nozzle is set smaller, and the chamber grid is set larger, saving the calculation cost while ensuring the accuracy of the calculation results.

[0036] For the premixed cold state general model, for the processes of gas and air entrainment and premixing, research on the characteristics of gas-air entrainment and premixing and flow resistance analysis are carried out for different stove structures. Focus on analyzing the process of fuel injection and mixing with air to form a combustible mixture in the complex space of different burners, and reveal the influence law of fuel injection parameters, burner structure parameters, etc. on the uniformity of the combustible mixture under the action of turbulence.

[0037] Simplified settings are made for the static premixed flow model, including: The rated gas supply pressure is the pressure at the nozzle inlet 1; The nozzle ejector hole 3 is directly connected to the outside, and its boundary condition is a normal temperature and normal pressure environment; The inlet of the ejector tube 7 is directly connected to the outside, and its boundary condition is the normal temperature and pressure environment; The outlet of the flame hole 5 is directly connected to the outside, and its boundary condition is the normal temperature and pressure environment; The boundary conditions of the nozzle and the wall surface of the burner head 4 are both constant wall temperature and no-slip.

[0038] In the flow of viscous fluids (such as gas and air), when the fluid contacts the solid wall surface, the tangential velocity of the fluid at the wall surface is consistent with the wall movement velocity. If the wall is stationary, the fluid velocity at the wall surface is zero, meaning the fluid will not slide along the wall.

[0039] Constant wall temperature means that in the simulation or physical system, the temperature of the solid wall surface is fixed at a certain constant value, which belongs to the fixed temperature type in the thermal boundary conditions.

[0040] The static premixed flow model mainly studies the mixing flow characteristics of gas and air in the non-combustion state, focusing on hydrodynamic parameters such as the flow field structure, turbulent mixing, pressure distribution, and velocity field. Its core assumption is to only simulate the gaseous mixing process at normal temperature.

[0041] S2. Set the boundary conditions of the static premixed flow model, including the boundary conditions of the primary air intake 10; in this embodiment, the boundary conditions of the primary air intake 10 are the parameters of the static premixed flow model in different regions, including: The pressure at the inlet 1 of the nozzle is 2800 Pa; the pressures at the ejector holes 3 of the nozzle, the inlet 7 of the ejector tube, and the outlet 8 of the ejector tube are all -5 Pa to 0 Pa; the wall temperatures of the nozzle and the ejector tube are both 300 K to 350 K.

[0042] In fluid mechanics and thermodynamics, the wall surface refers to the solid boundary of the fluid flow path, such as the inner surface of a pipe, nozzle, or burner. Its functions include restricting fluid flow, transferring heat, and bearing fluid pressure, etc. In a gas stove, the wall temperatures of the nozzle and the ejector tube will affect the preheating effect and combustion stability of the gas.

[0043] Set the ratio of the inlet air pressure and the inlet air mass of the nozzle; S3. Conduct a process simulation on the static premixed flow model; calculate / extract the first simulation results, including the entrainment efficiency of the ejector tube, and the ratio of the outlet gas flow velocity and the outlet gas mass of the flame hole 5; The types of gas burned by the gas stove include natural gas and liquefied petroleum gas; among them, the calculation of the entrainment efficiency of different types of gas stoves is different; When the gas is natural gas, the entrainment efficiency is , that is: ; When the gas is liquefied petroleum gas, the entrainment efficiency is , that is: ; Among them, n represents the molar fraction of the gas, respectively representing oxygen, methane, propane, and butane contained in the gas at the outlet of the flame hole 5.

[0044] The combustion of natural gas involves methane, that is, ; the combustion of liquefied petroleum gas involves propane and butane, that is, and .

[0045] Only when the first simulation result reaches the first preset standard, execute S4; otherwise, continue to execute S2.

[0046] In this embodiment, the first preset standard is that the entrainment efficiency is 0.5 - 0.8; the fluid velocity at the outlet of the flame hole 5 is 0.8 m / s - 1.0 m / s; S4. Construct a combustion-state heat transfer model of the gas stove according to the burner cap and the standard pot model 13; the combustion-state heat transfer model studies the chemical reactions, heat release, and heat transfer mechanisms during the combustion process, and is used for the refined analysis of combustion efficiency and emission performance. For the combustion process of the premixed gas 12, reveal the flame morphology, heat release, and the generation, migration, and evolution mechanisms of pollutants such as NOx and HC in the burner, and study the influence laws of different burner cap and stove rack structures on the thermal performance of the gas stove.

[0047] In this embodiment, the combustion-state heat transfer model further includes an influence space region 14 formed on the outer peripheral side of the standard pot model 13.

[0048] The large space outside the standard pot model 13 refers to the external environmental region where the gas and air are mixed and the flame propagates during the combustion process. In natural convection heat transfer, it refers to the open region where the boundary layer of the fluid (such as air) is not affected by adjacent walls or flows during its movement. Its core feature is the freedom of fluid movement. Even if the geometric space is limited, as long as the boundary layer is not disturbed, it can still be regarded as a "large space". For example, the air region around the gas stove flame that is not blocked by the cookware can be regarded as a large space for analyzing natural convection heat dissipation.

[0049] Perform a simplified setting on the combustion-state heat transfer model; in this embodiment, the simplified setting is as follows: On the same burner cap, the gas components of the gas ejected from each flame hole 5 are the same, and the distribution of the flame holes 5 is uniform; On the same burner cap, the outlet gas flow rates of each flame hole 5 are the same; When the combustion reaches a steady state, the temperature of the standard pot model 13 does not change, and the boundary condition of the wall surface of the standard pot model 13 is set to a constant wall temperature and no-slip; The boundary condition of the influence space region 14 is a normal temperature and pressure environment.

[0050] S5. Set the boundary conditions of the combustion heat transfer model, including the boundary conditions of the secondary air intake 11; The boundary conditions of the secondary air intake 11 are the parameters of the combustion heat transfer model in different regions, including: The pressures affecting the spatial region 14 on the side, top, and bottom are -0.1 Pa to 0 Pa, -0.1 Pa to 0 Pa, and 0 Pa to 2 Pa respectively; the wall temperature of the burner cap is 770 K - 800 K; the wall temperature of the standard pot model 13 is 550 K - 575 K; the velocity of the premixed gas 12 at the entrance of the flame hole 5 is 0 m / s to 2 m / s; the wall temperature of the secondary air intake 11 is 550 K - 575 K; the pressure of the secondary air intake 11 at the bottom of the standard pot model 13 is 0 Pa to 0.02 Pa.

[0051] The combustion heat transfer model involves the coupled process of flow and combustion. The surface of the burner cap is in direct contact with the flame; the wall temperature at the inlet of the secondary air intake 11 of the burner head 4 is 373 K; the bottom surface temperature of the pot is the boiling point of water at normal temperature and pressure, 373 K; the flame deviates from the bottom surface of the pot and diffuses outward along the circumferential direction, so a certain negative pressure is set for the large - space structure.

[0052] Set the ratio of the outlet gas velocity to the outlet gas mass; meanwhile, also set the combustion turbulence intensity and the wall temperature; in this embodiment, during a new round of iteration, the turbulence intensity of the combustion heat transfer model is corrected, that is: ; Wherein, represents the turbulence intensity, and ; refers to the Reynolds number.

[0053] The Reynolds number is a dimensionless number that can be used to characterize the fluid flow situation.

[0054] S6. Conduct a process simulation on the combustion heat transfer model; calculate / extract the second simulation results; in this embodiment, the second simulation results include the thermal efficiency and heat load of the gas stove, as well as the CO concentration emitted during combustion; Among them, the thermal efficiency refers to the efficiency of the gas stove in converting the chemical energy of the gas into the effective heat absorption of the standard pot model 13, and the heat load refers to the total energy released by the gas stove when burning gas per unit time; The second preset standard is that the thermal efficiency reaches or exceeds the preset rated thermal efficiency, the heat load is within the rated heat load range, and the CO concentration is less than 500 ppm; Thermal efficiency The calculation of is: ; Wherein, Represents the bottom heat load of the pot body of the standard pot model 13; Represents the side heat load of the pot body of the standard pot model 13; Represents the chemical heat release during combustion.

[0055] Except for the thermal efficiency, the remaining parameters are automatically simulated and generated by the simulation software.

[0056] Only when the second simulation result reaches the second preset standard, execute S7; otherwise, continue to execute S5; S7. Conduct proofing verification on the static premixed flow model and the combustion heat transfer model, and evaluate whether the performance of the sample meets the preset requirements; if not, execute step S5 to readjust the boundary conditions of the combustion heat transfer model, specifically several parameters related to temperature. If it meets, end the simulation analysis.

[0057] This application creatively divides the simulation of the static premixed flow model and the simulation of the combustion heat transfer model into two stages and conducts them successively. Only when the simulation of the gas stove through the static premixed flow model reaches the standard and is qualified, stop the iterative optimization of the static premixed flow model, and then conduct the iterative optimization of the combustion heat transfer model. Instead of, as in the prior art, conducting the cold-state simulation and the hot-state simulation simultaneously, and having to iterate all over again once the simulation result does not meet the standard. It effectively improves the working efficiency of the gas stove design simulation test and greatly reduces the time cost.

[0058] According to the disclosure and teachings of the above specification, those skilled in the art to which the present invention pertains can also make changes and modifications to the above embodiments. Therefore, the present invention is not limited to the specific embodiments disclosed and described above, and some modifications and changes to the present invention should also fall within the protection scope of the claims of the present invention. In addition, although some specific terms are used in this specification, these terms are only for convenience of description and do not constitute any limitation to the present invention.

Claims

1. A simulation analysis method for gas stoves based on static and combustion states, characterized in that, It includes the following steps: S1. Extract the structures of the nozzle, the ejector tube, the burner head, and the burner cap with flame holes in the gas stove, and construct a static premixed flow model of the gas stove; perform simplified settings on the static premixed flow model; S2. Set the boundary conditions of the static premixed flow model, including the primary air intake boundary condition; set the ratio of the inlet air pressure to the inlet air mass of the nozzle; S3. Perform process simulation on the static premixed flow model; calculate / extract the first simulation results, including the ejection efficiency of the ejector tube, and the ratio of the outlet gas velocity to the outlet gas mass of the flame hole; only when the first simulation results meet the first preset standard, execute S4, otherwise, continue to execute S2; S4. Construct a combustion-state heat transfer model of the gas stove; perform simplified settings on the combustion-state heat transfer model; S5. Set the boundary conditions of the combustion-state heat transfer model, including the secondary air intake boundary condition; set the ratio of the outlet gas velocity to the outlet gas mass; at the same time, also set the combustion turbulence intensity and the wall temperature; S6. Perform process simulation on the combustion-state heat transfer model; calculate / extract the second simulation results; only when the second simulation results meet the second preset standard, execute S7, otherwise, continue to execute S5; S7. Perform proofing verification on the static premixed flow model and the combustion-state heat transfer model, and evaluate whether the performance of the proofing sample meets the preset requirements; if not, execute step S5 and readjust the boundary conditions of the combustion-state heat transfer model; if so, end the simulation analysis.

2. The simulation analysis method of a gas stove based on static and combustion states according to claim 1, wherein The first preset standard is that the ejection efficiency is 0.5 - 0.8; the fluid velocity at the flame hole outlet is A1 m / s; the value range of A1 is 0.8 - 1.0; The gas types burned by the gas stove include natural gas and liquefied petroleum gas; When the fuel gas is natural gas, the entrainment efficiency is , that is: ； When the fuel gas is liquefied petroleum gas, the ejecting efficiency is , that is: ； where n represents the molar fraction of the gas, respectively representing oxygen, methane, propane, and butane contained in the gas at the outlet of the flame hole.

3. A simulation analysis method of a gas stove based on static and combustion states according to claim 1, characterized in that, In S5, during a new round of iteration, perform turbulence intensity correction on the combustion-state heat transfer model, that is: ； Among them, represents the turbulence intensity, and ; refers to the Reynolds number.

4. A simulation analysis method of a gas stove based on static and combustion states according to claim 1, characterized in that, The primary air intake boundary condition is the parameter of the static premixed flow model in different regions, including: The pressure at the nozzle inlet is B1 Pa; the pressures at the nozzle ejection hole, the ejector tube inlet, and the ejector tube outlet are all B2 Pa; the wall temperatures of the nozzle and the ejector tube are both B3 K; The value range of B1 is 2500 - 3000; the value range of B2 is -5 - 0; the value range of B3 is 300 - 350.

5. A simulation analysis method of a gas stove based on static and combustion states according to claim 1, characterized in that, When performing simulation on the gas stove, also set a standard pot model; In S4, construct the combustion-state heat transfer model according to the burner cap and the standard pot model; the combustion-state heat transfer model also includes an influence space area formed on the outer peripheral side of the standard pot model; The secondary air intake boundary condition is the parameter of the combustion-state heat transfer model in different regions, including: The pressures of the influence space region on the side, top, and bottom surfaces are C1 Pa, C2 Pa, and C3 Pa respectively; the wall temperature of the burner cap is C4 K; the wall temperature of the standard pot model is C5 K; the velocity of the premixed gas of the gas stove at the inlet of the flame hole is C6 m / s; the wall temperature of the secondary air intake is C7 K; the pressure of the secondary air intake at the bottom of the standard pot model is C8 Pa; The value range of C1 is -0.1 to 0; the value range of C2 is -0.1 to 0; the value range of C3 is 0 to 2; the value range of C4 is 770 to 800; the value range of C5 is 550 to 575; the value range of C6 is 0 to 2; the value range of C7 is 550 to 575; the value range of C8 is 0 to 0.

02.

6. A simulation analysis method of a gas stove based on static and combustion states according to claim 5, characterized in that The second simulation result includes the thermal efficiency and heat load of the gas stove, and the CO concentration emitted during combustion; Among them, the thermal efficiency refers to the efficiency of the gas stove converting the chemical energy of the gas into the effective heat absorption of the standard pot model, and the heat load refers to the total energy released by the gas stove burning the gas per unit time; The second preset standard is that the thermal efficiency reaches or exceeds the preset rated thermal efficiency, the heat load is within the rated heat load range, and the CO concentration is less than the set value; The thermal efficiency is calculated as follows: ； Among them, represents the bottom heat load of the pot body of the standard pot model; represents the side heat load of the pot body of the standard pot model; represents the chemical heat release during combustion.

7. A simulation analysis method of a gas stove based on static and combustion states according to claim 4, characterized in that The simplification in S1 is as follows: The rated gas supply pressure of the gas is the pressure at the inlet of the nozzle; The injection hole of the nozzle is directly connected to the outside, and its boundary condition is a normal temperature and normal pressure environment; The inlet of the injection pipe is directly connected to the outside, and its boundary condition is a normal temperature and normal pressure environment; The outlet of the flame hole is directly connected to the outside, and its boundary condition is a normal temperature and normal pressure environment; The boundary conditions of the walls of the nozzle and the burner head are both constant wall temperature and no-slip.

8. A simulation analysis method of a gas stove based on static and combustion states according to claim 5, characterized in that, The simplification in S4 is as follows: On the same burner cap, the gas components of the gases ejected from each flame hole are the same, and the distribution of the flame holes is uniform; On the same burner cap, the outlet gas velocities of each flame hole are the same; When combustion reaches a steady state, the temperature of the standard pot model does not change, and the boundary condition of the wall of the standard pot model is set to constant wall temperature and no-slip; The boundary condition of the influence space region is a normal temperature and normal pressure environment.

9. A simulation analysis method for a gas stove based on static and combustion states according to claim 1, characterized in that, After constructing the static premixed flow model, grid division is performed on the static premixed flow model; among them, grid refinement is performed on the nozzle region.

10. A simulation analysis method of a gas stove based on static and combustion states according to claim 5, characterized in that, In step S7, if the preset requirements are not met, then step S5 is executed to readjust C4, C5, and C7.

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