A linear flame modeling method

Abstract

The invention discloses a linear flame modeling method, firstly, a linear burner is divided into a plurality of regions along a linear direction, then a flame shape approximation diagram is established with the linear load ratio of each region as the ordinate and the label of each region as the abscissa, and finally the linear flame modeling is assisted according to the flame shape approximation diagram. The flame modeling method of the invention can accurately determine the design scheme to the minimum range before experiments and numerical calculations, can greatly simplify the design process, and provide a highly reliable guidance scheme for flame modeling.

Description

Technical Field

[0001] The invention relates to a linear flame shaping method and belongs to the technical field of burners. Background Art

[0002] Flame shaping is very useful in the field of fireworks performances, where engineers need to achieve different flame shapes based on visual and performance requirements. Similarly, in the field of thermal energy engineering, industrial furnace burners need to adjust flame shapes based on load conditions to meet engineering needs.

[0003] Different from the flame produced by a square or circular burner, a linear flame is a flame formed by one or more burners arranged in a linear direction. Patent CN201720508919.0 mentions a linear flame stabilizing structure and describes the flame stabilizing structure using an air outer guard plate. Patent CN204213926U mentions the structure of a modular linear burner and describes the modular structure for constructing a linear burner. In addition, some researchers have studied linear flames or linear burners, but there is no modeling construction method for linear flames in the prior art, especially when there are engineering problems that require flame shape construction. If a flame modeling estimation method can be used, the design scheme can be quickly determined and the engineering implementation stage can be entered. Summary of the invention

[0004] The purpose of the present invention is to overcome the above defects and provide a linear flame shaping method, which divides the linear burner into n areas along the linear direction and adjusts the linear load ratio of each area. The flame shape approximation diagram is established with the ordinate as the ordinate and the labels of each area as the abscissa; the linear flame modeling is assisted according to the flame shape approximation diagram. The flame modeling method of the present invention can accurately determine the design scheme to the minimum range before the test and numerical calculation, can greatly simplify the design process, and provide a highly reliable guidance scheme for flame modeling.

[0005] In order to achieve the above-mentioned object of the invention, the present invention provides the following technical solutions:

[0006] A linear flame modeling method, comprising:

[0007] The linear burner is divided into n regions along the linear direction, and the length of each region is recorded as L i ; n>0, i is the number of each region, indicating the i-th region along the linear direction, i=1, 2, ...n;

[0008] Get the heat load Q of each area i ;

[0009] Get the total load Q of the linear burner;

[0010] Calculate the heat load Q of each area iThe heat load ratio q of each area relative to the total load Q of the linear burner i ;

[0011] According to the heat load proportion of each area q i and the length L of each region i , get the line load ratio of each area

[0012] Based on the line load ratio of each area Establish an approximate flame shape diagram with the ordinate as the ordinate and the labels of each area as the abscissa;

[0013] The linear burner is controlled according to the flame shape approximation diagram to obtain the desired linear flame shape.

[0014] Furthermore, the heat load ratio of each area is q i =Q i / Q;

[0015] Line load ratio of each area

[0016] Furthermore, the linear burner is one burner that can independently generate a linear flame, or is a burner group consisting of more than one burner arranged linearly.

[0017] Furthermore, when the flame produced by the linear burner is a buoyancy-controlled flame, the linear load ratio of each area The flame shape approximation diagram is established in the form of a scatter point connection diagram with the ordinate as the ordinate and the labels of each area as the abscissa;

[0018] When the flame produced by the linear burner is a momentum controlled flame, the linear load ratio of each area With the vertical axis as the ordinate and the number of each area as the horizontal axis, an approximate flame shape diagram is established in the form of a bar graph.

[0019] Furthermore, according to the Froude number Fr f Determine the type of flame produced by the linear burner.

[0020] Furthermore, when Fr f When <5, the flame produced by the linear burner is considered to be a buoyancy-controlled flame;

[0021] When Fr f When ≥5, the flame produced by the linear burner is considered to be a momentum-controlled flame.

[0022] Furthermore, in the n regions, the number of nozzles included in each region is ≥0, and the total number of nozzles included in the n regions is >0.

[0023] Furthermore, the heat loads of the nozzles in the same area are equal.

[0024] Furthermore, the lengths of the regions are equal or unequal.

[0025] Furthermore, the heat load Q of each area i The calculation is based on the heat load of the nozzles contained in this area.

[0026] Compared with the prior art, the present invention has at least one of the following beneficial effects:

[0027] (1) The present invention innovatively provides a flame shaping method, which can accurately determine the design scheme to the minimum range before testing and numerical calculation, greatly simplifying the design process and providing a highly reliable guidance scheme for flame shaping;

[0028] (2) The burner targeted by the present invention can be a single burner or a burner group composed of a series of burners. When dividing the area, it is not necessary to mechanically divide it into equal distances, and it has wide applicability;

[0029] (3) The present invention adopts a method of converting the heat load of each area into a load proportion, which can effectively improve the flame shape approximation;

[0030] (4) The present invention reasonably considers the flame type and reasonably establishes a flame shape approximation diagram according to the flame type, thereby further improving the flame shape approximation. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 A flow chart of a linear flame shaping method in a preferred embodiment of the present invention;

[0032] Figure 2 A schematic diagram of the linear burner nozzle opening and the division of various regions used in Example 1 of the present invention;

[0033] Figure 3 is a line load ratio diagram obtained in Example 1 of the present invention;

[0034] Figure 4 This is a photograph of the linear flame modeling obtained in Example 1 of the present invention. DETAILED DESCRIPTION

[0035] The following detailed description of the present invention will make the features and advantages of the present invention more clear and explicit.

[0036] The word "exemplary" is used exclusively herein to mean "serving as an example, embodiment, or illustration." Any embodiment described herein as "exemplary" is not necessarily to be construed as preferred or advantageous over other embodiments. Although various aspects of the embodiments are shown in the drawings, the drawings are not necessarily drawn to scale unless otherwise noted.

[0037] In engineering, if the flame shape of linear flame combustion needs to be constructed, it is often necessary to judge through relatively complex methods such as experiments and numerical calculations. Most of these methods are time-consuming and labor-intensive, and if there are many working conditions, they will be difficult to implement. The flame shaping method provided by the present invention can accurately determine the design scheme to the minimum range before experiments and numerical calculations, which can greatly simplify the design process and provide a highly reliable guidance scheme for flame shaping.

[0038] The invention discloses a linear flame shaping method, wherein the linear burner is divided into a plurality of regions along a linear direction, and the length of each region is L1, L2, ...L n , calculate the heat load Q1, Q2, ...Q of each area respectively i , and calculate the load proportion of each area heat load to the total burner load q1, q2, ...q i , that is, q i =Q i / Q, the ratio of the heat load of each area to the length of each area is calculated to obtain the line load ratio of each area Line load ratio With the vertical coordinate as the ordinate and the region number i as the horizontal coordinate, an approximate diagram of the flame shape can be obtained to assist in modeling design.

[0039] Furthermore, for different types of flames, especially buoyancy-controlled flames and momentum-controlled flames, it is necessary to distinguish the flame shapes. For example, if the flame of a linear burner is a buoyancy-controlled flame, the flame is relatively floating, and the shape formed is a smooth transition. The scatter point connection diagram is the approximate shape of the flame, which has a good approximation degree; if the flame is a momentum-controlled flame, the flame is relatively rigid, and the shape formed should be stepped. The bar graph is the approximate shape of the flame, which has a good approximation degree.

[0040] Furthermore, the Froude number Fr is generally used f To distinguish the momentum control mode and buoyancy control mode of the flame. For turbulent jet flames, when Fr f When Fr is less than 5, it is considered to be a flame controlled by buoyancy. f When ≥5, it is considered to be momentum controlled flame.

[0041] Furthermore, the linear burner may be a single burner forming a linear flame, or may be a plurality of burners forming a linear flame together.

[0042] Furthermore, when the linear burner is divided into multiple regions along the linear direction, the length of each region is not restricted, and the boundaries of each region can be set according to the specific situation to facilitate the estimation of the flame situation. However, it is necessary to ensure that the heat load of each nozzle in a single region is consistent. If it is inconsistent, it will lead to deviations in the flame shape estimation within the region and reduce the accuracy of the flame shape approximation. That is, the regions can be unequally divided, but the heat load of each nozzle in each region must be consistent.

[0043] Embodiment 1:

[0044] This embodiment will be combined with the attached Figures 1 to 4 The flame modeling method of the present invention is further described.

[0045] The flame shaping method of the invention is applied to a hydrogen energy handheld torch.

[0046] like Figure 2 The linear burner is divided into 5 areas, each area contains a number of nozzles, and the total number of nozzles is 24. Specifically, the number of nozzles contained in the 1st to 5th areas is 2, 6, 6, 8, and 3 respectively. The opening diameter of the nozzles in each area is equal.

[0047] According to the heat load of the nozzle, Figure 1 Methods The line load ratio of each area is converted and the line load ratio of each area is drawn.

[0048] In this embodiment, the total load of the linear burner is Q=36kW, and the data of each area are shown in Table 1:

[0049] Table 1 Data of each area of ​​linear burner

[0050]

[0051] The line load ratio of the 1st to 5th area is used as the vertical axis, and the area numbers 1 to 5 are used as the horizontal axis to establish the following Figure 3 The flame shape approximation diagram shown in the figure shows that the flame in this embodiment is a buoyancy-controlled flame, and a scatter point connection diagram has a better approximation effect. The flame shape approximation diagram is compared with the expected linear flame shape, and the linear burner is controlled according to the comparison result to achieve the following: Figure 4 Desired linear flame shape shown.

[0052] In this embodiment, the linear burner is bent according to the curved surface characteristics of the torch during actual use.

[0053] The present invention has been described in detail above in conjunction with specific implementations and exemplary examples, but these descriptions cannot be understood as limiting the present invention. Those skilled in the art understand that, without departing from the spirit and scope of the present invention, a variety of equivalent substitutions, modifications or improvements may be made to the technical solution of the present invention and its implementation methods, all of which fall within the scope of the present invention. The scope of protection of the present invention shall be subject to the attached claims.

[0054] The contents not described in detail in the specification of the present invention belong to the common knowledge of those skilled in the art.

Claims

1. A method for shaping a linear flame, characterized in that: include: The linear burner is divided into n regions along the linear direction, and the length of each region is recorded as L i ; n>0, i is the number of each region, indicating the i-th region along the linear direction, i=1, 2, ...n; Get the heat load Q of each area i ; Get the total load Q of the linear burner; Calculate the heat load Q of each area i The heat load ratio q of each area relative to the total load Q of the linear burner i ; According to the heat load proportion of each area q i and the length L of each region i , get the line load ratio of each area Based on the line load ratio of each area Establish an approximate flame shape diagram with the ordinate as the ordinate and the labels of each area as the abscissa; The linear burner is controlled according to the flame shape approximation diagram to obtain the desired linear flame shape.

2. A linear flame shaping method according to claim 1, characterized in that: Heat load ratio of each area q i =Q i / Q; Line load ratio of each area 3. A linear flame shaping method according to claim 1, characterized in that: A linear burner is a burner that can independently generate a linear flame, or a burner group consisting of more than one burner arranged linearly.

4. A linear flame shaping method according to claim 1, characterized in that: When the flame produced by the linear burner is a buoyancy controlled flame, the linear load ratio of each area The flame shape approximation diagram is established in the form of a scatter point connection diagram with the ordinate as the ordinate and the labels of each area as the abscissa; When the flame produced by the linear burner is a momentum controlled flame, the linear load ratio of each area With the vertical axis as the ordinate and the number of each area as the horizontal axis, an approximate flame shape diagram is established in the form of a bar graph.

5. A linear flame shaping method according to claim 4, characterized in that: According to the Froude number Fr f Determine the type of flame produced by the linear burner.

6. A linear flame shaping method according to claim 5, characterized in that: When Fr f When <5, the flame produced by the linear burner is considered to be a buoyancy-controlled flame; When Fr f When ≥5, the flame produced by the linear burner is considered to be a momentum-controlled flame.

7. A linear flame shaping method according to claim 1, characterized in that: In the n regions, the number of nozzles contained in each region is ≥0, and the total number of nozzles contained in the n regions is >0.

8. A linear flame shaping method according to claim 7, characterized in that: The heat load on nozzles in the same area is equal.

9. A linear flame shaping method according to claim 1, characterized in that: The lengths of the regions may be equal or unequal.

10. A linear flame shaping method according to claim 1, characterized in that: Heat load Q of each area i The calculation is based on the heat load of the nozzles contained in this area.

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