Energy-saving enclosure device with secondary air guide structure

Abstract

This invention discloses an energy-saving enclosure device with a secondary airflow structure for use in direct-fire heating equipment. The device includes a base plate and an energy-saving enclosure. The enclosure is composed of two or more converging baffles. A sufficient gap exists between adjacent converging baffles. Each converging baffle includes a baffle body and a raised surface. The raised surface has an opening at its upper end and continuously bulges inward along the longitudinal extension direction of the baffle body. The raised surface is symmetrically arranged with its longitudinal central ridge line as the axis of symmetry, and its cross-sectional profile on a plane perpendicular to the longitudinal central ridge line is an inwardly convex arc shape. The curvature of the raised surface gradually decreases from top to bottom. Air outside the energy-saving enclosure communicates with the inner area of ​​the enclosure through the upper opening of the raised surface, forming a secondary airflow channel. Therefore, this invention can accelerate airflow, enhance secondary mixing and combustion, achieve active air replenishment, optimize combustion conditions, improve heating uniformity, and alleviate uneven burning.

Description

Technical Field

[0001] This invention relates to an energy-saving enclosure device with a secondary airflow guiding structure, used in direct-fire heating equipment, and belongs to the field of energy-saving control technology. Background Technology

[0002] Gas stoves are the most common cooking appliances in homes and the catering industry. Their core structure consists of a valve body, burner head (including the ejector), burner cap (flame distributor), and related pot supports and structural elements. The burner head ensures thorough mixing of gas and primary air. The burner cap consists of a central burner cap and an outer ring burner cap, with numerous perforations on its surface to ensure a uniform and stable high-temperature airflow (flame). During use, gas initially mixes with air in the burner head. The mixture is then regulated and injected through the valve body, ejected from the burner cap's perforations, and finally ignited by the ignition needle. Any insufficiently mixed gas continues to mix with the surrounding air in subsequent flows (secondary mixing) for combustion. However, in practice, due to poor design and manufacturing quality of the valve body, burner head, etc., uneven high-temperature airflow (flame) combustion can easily occur, with one side of the flame burning better than the other. Furthermore, the high-temperature airflow (flame) mostly concentrates at the bottom of the cookware, and a considerable amount of heat from the high-temperature airflow (flame) is not directly transferred to other parts of the cookware (such as the sides), but can only be transferred through the heat conduction of the cookware itself, resulting in energy waste. In addition, due to the incomplete mixing and combustion of gas and air in the first stage, the heat generated by the secondary mixing and combustion is also difficult to be efficiently transferred to the cookware.

[0003] Similar problems exist in direct-fire heating equipment used in the deep processing of agricultural products, such as disc dryers and rotary drying drums. These devices directly heat the bottom or outer wall of the container through flames generated by combustion in a furnace, resulting in extremely uneven heat distribution. This can easily lead to localized overheating or underheating of materials during drying or heat treatment, affecting product quality consistency. Especially for natural product extracts rich in polyphenols, flavonoids, and other active ingredients, localized high temperatures can even cause degradation or loss of these active ingredients. Furthermore, existing direct-fire heating equipment lacks effective guidance and constraint of flame and hot airflow direction in its combustion furnace, making it difficult to create a uniform and stable thermal environment around the material-bearing container (such as drying trays or rotary drums), thus affecting processing efficiency and product quality consistency.

[0004] In summary, existing direct-fired heating vessels have significant shortcomings in areas such as secondary mixing of high-temperature airflow (high-temperature airflow (flame)) and uniform heating. There is an urgent need for a device that can control the position of the high-temperature airflow (high-temperature airflow (flame)) while also promoting secondary mixing and even combustion, thereby improving energy and fuel utilization, further ensuring uniform heating of the direct-fired heating vessel, and comprehensively enhancing the performance of direct-fired heating equipment. Summary of the Invention

[0005] The purpose of this invention is to provide an energy-saving enclosure device with a secondary airflow structure, which aims to solve the technical problems of existing direct-fire heating equipment (such as household stoves, baking trays and baking drums with direct-fire heating), such as flame deviation, low heat utilization, uneven heating, and incompatibility with various direct-fire heating equipment.

[0006] To achieve the above-mentioned technical objectives, the present invention will adopt the following technical solution: An energy-saving enclosure device with a secondary airflow structure includes a base plate and an energy-saving enclosure set on the base plate; the energy-saving enclosure is formed by two or more converging baffles; there is a gap that meets the requirements between two adjacent converging baffles; The gathering baffle includes a baffle body and a raised surface; wherein: The upper end of the raised surface is provided with an opening, and the remaining end faces are sealed to or integrally formed with the inner wall of the baffle body, and continuously bulge inward along the longitudinal extension direction of the baffle body; the raised surface is symmetrically arranged on the left and right with its longitudinal central ridge line as the axis of symmetry, and the cross-sectional profile of the raised surface on the plane perpendicular to the longitudinal central ridge line is an inwardly convex arc shape, while the curvature of the raised surface gradually decreases from the top to the bottom. The air outside the energy-saving enclosure connects with the inner area of ​​the enclosure through the upper opening of the raised surface, forming a secondary airflow channel.

[0007] Preferably, the lower end of the gathering baffle is connected to the base plate via a hinge, and a spring is installed between the gathering baffle and the base plate; the initial preload provided by the spring can ensure that the included angle α between the gathering baffle and the base plate is 105°~120°.

[0008] Preferably, the surface of the gathering baffle is set as a straight surface near the hinge and an arc-shaped surface away from the hinge, and the radius R1 of the arc-shaped surface and the longitudinal length L of the gathering baffle satisfy: 1.75L≤R1≤2.25L.

[0009] Preferably, the first preset position is set close to the installation position of the hinge, while the second preset position can ensure that the projection length H of the longitudinal center ridge of the raised surface in the vertical direction and the longitudinal length L of the gathering baffle satisfy: H = (70%~90%)L.

[0010] Preferably, the ridge angle β of the raised surface satisfies: 1.1γ≤90°-β≤1.25γ, where γ is the normal deviation angle of the flame hole provided on the outer ring flame cap.

[0011] Preferably, the raised surface is part of a cylindrical surface, and its outer radius R2 and the width W of the baffle body satisfy: 0.1W≤R2≤0.3W.

[0012] Preferably, the angle δ between the generatrix of the cylindrical surface of the raised surface and the side of the converging baffle does not exceed 10°; the angle θ between the line connecting the symmetrical plane of the baffle body and the generatrix of the cylindrical surface does not exceed 25°.

[0013] Preferably, the vertical projection height of the tip of the baffle body and the side near the hinge is T1, and the vertical projection height of the raised surface is T2, which satisfies: T2 ≤ T1 ≤ 1.2T2.

[0014] Preferably, the thickness of the gathering baffle is 1mm to 2.5mm.

[0015] Preferably, the number of converging baffles is the same as the number of original pot rack supports of the stove, and the width W of the baffle body is equal to the distance between adjacent pot rack supports.

[0016] Based on the above-mentioned technical objectives, the present invention has the following advantages compared with the prior art: The energy-saving enclosure device with a secondary airflow structure described in this invention accelerates airflow, enhances secondary mixing and combustion, and achieves active air replenishment by setting a specific structural protrusion on the inner wall of the converging baffle. This optimizes combustion conditions and improves the heating uniformity of direct-fire heating containers such as pots, baking trays, and rotary drums, thus alleviating uneven heating. Specifically: 1. The convex profile gradually converges longitudinally from top to bottom (wider at the top and narrower at the bottom). As the flame gas rises along the inner surface of the baffle, the air passages flowing through both sides of the convex profile gradually contract, increasing the airflow velocity. According to Bernoulli's principle in fluid mechanics, the increased velocity leads to a decrease in local pressure, thus forming a stronger low-pressure zone around the convex profile and inducing a more intense longitudinal vortex. This vortex significantly enhances the turbulent mixing of unburned gas and secondary air, resulting in more complete combustion. With optimized design, using natural gas as the primary fuel, the combustion efficiency of this invention can be improved by more than 5‰ under typical operating conditions.

[0017] 2. The raised surface is hollow inside and open at the top, forming a secondary airflow channel from the outside to the inside of the energy-saving enclosure. During operation, the negative pressure in the inner flame zone is transmitted to the internal cavity of the raised surface through the upper opening, drawing in fresh air from the outside and allowing it to flow upwards along the cavity before finally being injected into the flame zone from the upper opening. This airflow channel has the following advantages: directional air supply: secondary air is directly injected into the high-temperature flame zone, precisely participating in combustion; air preheating: the air is preheated by the metal wall of the raised surface as it flows within the cavity, which helps to increase the combustion temperature; aligned with the mainstream: the direction of the ejected air is consistent with the upward direction of the flame, avoiding cross-blowing that interferes with flame stability.

[0018] 3. The symmetrical ridge structure of the convex surface and the longitudinal vortices it induces can draw high-temperature gas from the core of the flame to both sides, expanding the radial distribution range of heat. Simultaneously, the converging design of the convex surface from top to bottom increases the airflow velocity along the path, with the airflow velocity being faster and the heat exchange more intense closer to the bottom of the direct-fire heating container (such as a pot), compensating for insufficient heat loss from the upper part of the flame. Furthermore, the gaps between the converging baffles allow for a suitable amount of air to enter, preventing oxygen-deficient combustion due to excessive sealing, further ensuring the uniformity of the temperature field. Through design optimization, the average temperature (thermodynamic temperature scale) at the bottom of the pot can be increased by more than 3‰; the area with a temperature (thermodynamic temperature scale) less than 1% can be increased by more than double, and the temperature drop at the edge of the pot compared to the center is reduced by more than 30%.

[0019] 4. This invention utilizes the converging effect of the converging baffle on the high-temperature airflow (flame), so that most of the high-temperature airflow (flame) is trapped between the direct-fire heating container (such as a pot) and the converging baffle, thereby reducing the energy carried away by the traditional flue gas and the energy of radiation / convection heat dissipation to the environment. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of an energy-saving enclosure device with a secondary airflow guiding structure. Figure 2 An isometric view of the converging baffle; Figure 3 The front view of the convergence baffle; Figure 4 A top view of the converging baffle; Figure 5 A side view (half section) of the converging baffle. Figure 6 This is a schematic diagram showing the angle of the burner holes on a gas stove. Figure 7 A diagram showing a frying pan placed on a baffle plate; Figure 8 A diagram showing a wok placed on a baffle plate; Figure 9 The static temperature contour plot of the radial section is obtained by numerical simulation of the basic configuration (a simplified model of a flat-bottomed pan without a baffle) under simplified typical working conditions. Figure 10 The numerical simulation static temperature contour map of the radial section is obtained when the improved configuration (a simplified model of a flat-bottomed pan with a gathering baffle) is in a simplified typical working condition. Figure 11 This is the radial temperature distribution from the center of the pan to one side. In the figure: the red solid line is the temperature distribution of the basic configuration, and the green dashed line is the temperature distribution of the improved configuration; the horizontal axis represents the radius R from the center of the pan to one side.

[0021] Figure 12It is the velocity vector diagram of the improved configuration near the convergent baffle; The diagram includes: 1. Tabletop, 2. Converging baffle, 2.1. Baffle body, 2.2. Raised surface, 3. Pot support, 4. Base plate, 5. Hinge, 6. Outer ring burner cap, 7. Burner hole, 8. Central high-temperature gas injection ring (central burner cap). Detailed Implementation

[0022] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. The following description of at least one exemplary embodiment is merely illustrative and is in no way intended to limit the present invention or its application or use. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention. Unless otherwise specifically stated, the relative arrangement, expressions, and values ​​of components and steps set forth in these embodiments do not limit the scope of the present invention. Techniques, methods, and devices known to those skilled in the art may not be discussed in detail, but where appropriate, such techniques, methods, and devices should be considered part of the specification. In all examples shown and discussed herein, any specific values ​​should be interpreted as merely exemplary and not as limitations. Therefore, other examples of exemplary embodiments may have different values.

[0023] For ease of description, spatial relative terms such as "above," "over," "on the upper surface of," "above," etc., are used here to describe the spatial positional relationship of a device or feature as shown in the figure with other devices or features. It should be understood that spatial relative terms are intended to encompass different orientations in use or operation besides the orientation of the device as described in the figure. For example, if the device in the figure is inverted, a device described as "above" or "above" other devices or structures would subsequently be positioned as "below" or "under" other devices or structures. Thus, the exemplary term "above" can include both "above" and "below." The device may also be positioned in other different ways (rotated 90 degrees or in other orientations).

[0024] like Figure 1As shown, the energy-saving enclosure device with a secondary airflow structure of the present invention includes a base plate 4, four converging baffles 2 (corresponding to a four-claw pot rack), and a hinge 5 connecting the base plate 4 and each converging baffle 2. Each converging baffle 2 includes a baffle body 2.1 and a raised surface 2.2. The outer edge of the base plate 4 can be square, or it can be adapted to the installation environment. The inner edge can be circular according to the shape of existing household stoves, or it can be square according to general combustion furnaces. In short, it needs to match the shape of the furnace opening. For existing household stoves, it can be placed on the stove surface 1 and under the original pot rack support 3. For existing direct-fire heating equipment such as disc dryers and baking drums, the base plate can be connected to the furnace opening of the combustion furnace as one piece. The hinge 5 is installed on the outer edge of the base plate 4, allowing the converging baffles 2 to rotate around the hinge 5. Each hinge 5 is also equipped with a spring (not shown in the figure), with one end of the spring abutting against the base plate 4 and the other end abutting against the gathering baffle 2.

[0025] The springs are primarily selected from torsion springs or elastic steel sheets. The spring selection follows existing mechanical design principles, aiming to ensure that when no direct-heating container (such as a pot) is placed, the spring force slightly opens several converging baffles, bringing them nearly upright. When the direct-heating container (such as a pot) is placed down, the converging baffles open and close accordingly. When no direct-heating container is placed down, such as a pot, the angle α between the converging baffles and the base plate should ideally be between 105° and 120°. In the attached diagram, when no direct-heating container is placed, the initial preload provided by the torsion spring ensures that the converging baffles 2 automatically open to an angle of approximately 110° with the base plate 4.

[0026] Reference Figures 2 to 5 The width W of the baffle body 2.1 is equal to the gap width between the adjacent pot support 3. The height L′ of the pot support 3 and the length L of the baffle body 2.1 satisfy 2L′≤L≤4.5L′. The lower boundary value 2L′ ensures that the converging baffle can rotate freely without interfering with the stove surface, while also ensuring that the converging baffle effectively "wraps" the side edge of the flame to achieve a converging effect. The upper boundary value 4.5L′ effectively limits the cantilever length of the converging baffle. Generally, although an excessively long converging baffle covers a large area, it will affect the stability of direct-fire heating containers (such as pots) placed on the burner / stove head and affect the secondary contact between the flame and air.

[0027] The projection of the baffle body is rectangular, but its shape changes continuously. The side of the baffle body 2.1 near the hinge 5 is a flat surface, and the side away from the hinge 5 is an arc surface. Its arc radius R1 satisfies 1.75L≤R1≤2.25L.

[0028] The raised surface 2.2 begins to protrude from near the hinge 5 and extends to approximately 15 mm from the tip of the baffle body 2.1. The raised surface 2.2 is symmetrical about its longitudinal central ridge. The raised surface 2.2 is part of a cylindrical surface, and its outer radius R2 satisfies the condition 0.1W ≤ R2 ≤ 0.3W with respect to the width W of the baffle body 2.1. The projected length H of the longitudinal central ridge of the raised surface satisfies a certain relationship with the length L of the baffle body: H = (70%~90%)L. This size is chosen based on a trade-off between the benefits of secondary air mixing with partially combusted high-temperature gases and the heat loss caused by the temperature drop resulting from the introduction of secondary air. If the projected length H is small, the secondary air will be injected near the flame nozzle. The convex shape will affect the effect of primary combustion, and the amount of secondary air introduced by the convex shape will be very small. Conversely, the contact area between the secondary air and the high-temperature gas is small, the mixing effect is poor, it is difficult to achieve effective combustion, and it may even reduce the temperature of the high-temperature gas due to the introduction of too much secondary air, resulting in unnecessary energy loss.

[0029] From the top view of the converging baffle, the apex of the arc-shaped baffle body is tangent to the straight edge near the hinge, and all the surfaces on the converging baffle are located on one side passing through the hinge plane. To ensure that the bottom of the pot fits snugly against the tip area of ​​the baffle body 2.1, while the raised surface 2.2 is located below the bottom of the pot but not in direct contact, the vertical projection height T1 between the tip of the baffle body 2.1 and the hinge side and the vertical projection height T2 of the raised surface 2.2 satisfy: T2 ≤ T1 ≤ 1.2T2. Therefore, for most direct-fire heating containers (such as pots), this invention can introduce secondary air through the raised surface, promote the secondary combustion of high-temperature gas, and enhance mixing.

[0030] Considering the upward buoyancy of high-temperature gas, the outer ring of the burner cap 6 in this invention is provided with a ring of flame holes. The normal deviation angle γ of the flame holes (i.e., the projection of the angle between the flame hole axis and the radius direction onto the horizontal plane) and the ridge angle β of the raised surface satisfy: 1.1γ ≤ 90° - β ≤ 1.25γ. This design ensures that the ridge of the raised surface is more inclined than the flame hole axis. Coupled with the upward buoyancy of the high-temperature gas, this makes the direction of the flame jet closer to the direction of secondary air entry, resulting in better mixing and afterburning effects.

[0031] The raised surface requires special design. Considering thermal deformation, manufacturing, cost, and usage, the raised surface is part of the cylindrical surface. The angle δ between the generatrix of the raised cylindrical surface (the axis of the cylinder) and the side of the converging baffle generally does not exceed 10° (optionally, δ=5°). This is because if the angle δ is too large, the raised surface will contact the bottom of the direct-fire heating container (such as a pot) first, which is inconsistent with the original design. The angle θ between the line connecting the symmetrical plane of the converging baffle body and the generatrix of the cylindrical surface (the axis of the cylinder) does not exceed 25° (optionally, θ=15°). A large angle θ will cause the raised surface to affect the high-temperature combustion gas, hindering the mixing and afterburning of secondary air. Similarly, excessively large angles can cause cracks during manufacturing, which is detrimental to long-term use.

[0032] The connection between the baffle body 2.1 and the raised surface 2.2 is rounded with R1, and the whole is made of 1.5mm thick stainless steel plate by stamping.

[0033] Reference Figure 7 When a frying pan is placed, the bottom surface of the direct-fire heating container (such as a pot) first contacts the flat tip of the baffle body 2.1. As it continues to press down, the baffle 2 overcomes the torsion spring force and opens outward. Finally, the bottom of the pan fits into the tip area of ​​the baffle body 2.1. The raised surface 2.2 is located below the bottom of the pan but does not directly contact it, which plays a role in guiding the flame and generating a vortex.

[0034] Reference Figure 8 When a direct-fire heating container (curved bottom) is placed, the bottom surface of the direct-fire heating container fits against the raised surface 2.2, while a gap remains between the tip of the baffle body 2.1 and the bottom of the pot. Due to the support of the raised surface 2.2, the wok is raised, allowing the flame to be evenly distributed along the curved surface of the pot bottom. At the same time, the guiding effect of the raised surface 2.2 promotes the secondary mixing of the flame and air.

[0035] Figures 9 to 12 Numerical simulation results of the basic configuration (a simplified model of a frying pan without a baffle) and the improved configuration (a simplified model of a frying pan with a baffle) under simplified typical working conditions are disclosed. Based on Figure 9 , Figure 10 The publicly available numerical simulation static temperature cloud maps of both devices show that placing a converging baffle under the pan can make the high-temperature zone under the pan more uniform and achieve a higher temperature. Based on Figure 11 The publicly available temperature distribution comparison charts show that placing a converging baffle under the pan results in a higher temperature near the edge and a better average temperature at the bottom of the pan. Based on Figure 12The publicly available velocity vector diagram near the converging baffle shows that some airflow is drawn into the area below the pan through the convex surface of the converging baffle, where it undergoes secondary combustion and enhanced mixing. Statistical analysis shows that in areas where the pan bottom thermodynamic temperature decreases by less than 1%, the improved configuration increases by 165% compared to the basic configuration; a 1% increase in combustion efficiency results in a 5‰ increase in the average pan bottom thermodynamic temperature, and a 36% reduction in the pan edge temperature.

[0036] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. An energy-saving enclosure device with a secondary airflow guiding structure, comprising a base plate and an energy-saving enclosure disposed on the base plate; characterized in that, Energy-saving enclosures are formed by two or more clustered baffles; there are gaps between adjacent clustered baffles that meet the requirements; The gathering baffle includes a baffle body and a raised surface; wherein: The upper end of the raised surface is provided with an opening, and the remaining end faces are sealed to or integrally formed with the inner wall of the baffle body, and continuously bulge inward along the longitudinal extension direction of the baffle body; the raised surface is symmetrically arranged on the left and right with its longitudinal central ridge line as the axis of symmetry, and the cross-sectional profile of the raised surface on the plane perpendicular to the longitudinal central ridge line is an inwardly convex arc shape, while the curvature of the raised surface gradually decreases from the top to the bottom. The air outside the energy-saving enclosure connects with the inner area of ​​the enclosure through the upper opening of the raised surface, forming a secondary airflow channel.

2. The energy-saving enclosure device with a secondary airflow guiding structure according to claim 1, characterized in that, The lower end of the gathering baffle is connected to the base plate via a hinge, and a spring is installed between the gathering baffle and the base plate; the initial preload provided by the spring can ensure that the included angle α between the gathering baffle and the base plate is 105°~120°.

3. The energy-saving enclosure device with a secondary airflow guiding structure according to claim 2, characterized in that, The surface of the gathering baffle is set as a flat surface near the hinge and an arc-shaped surface away from the hinge. The radius R1 of the arc-shaped surface and the longitudinal length L of the gathering baffle satisfy: 1.75L≤R1≤2.25L.

4. The energy-saving enclosure device with a secondary airflow guiding structure according to claim 3, characterized in that, The first preset position is set close to the hinge installation position, while the second preset position can ensure that the vertical projection length H of the longitudinal center ridge of the raised surface and the longitudinal length L of the gathering baffle satisfy: H = (70%~90%)L.

5. The energy-saving enclosure device with a secondary airflow guiding structure according to claim 4, characterized in that, The ridge angle β of the raised surface satisfies: 1.1γ≤90°-β≤1.25γ, where γ is the normal deviation angle of the fire hole set on the outer ring fire cap.

6. The energy-saving enclosure device with a secondary airflow guiding structure according to claim 1, characterized in that, The raised surface is part of the cylindrical surface, and its outer radius R2 and the width W of the baffle body satisfy: 0.1W≤R2≤0.3W.

7. The energy-saving enclosure device with a secondary airflow guiding structure according to claim 1, characterized in that, The angle δ between the generatrix of the cylindrical surface of the raised surface and the side of the converging baffle does not exceed 10°; the angle θ between the line connecting the symmetrical plane of the baffle body and the generatrix of the cylindrical surface does not exceed 25°.

8. The energy-saving enclosure device with a secondary airflow guiding structure according to claim 1, characterized in that, The vertical projection height of the tip of the baffle body and the side near the hinge is T1, and the vertical projection height of the convex surface is T2. The two satisfy: T2 ≤ T1 ≤ 1.2T2.

9. The energy-saving enclosure device with a secondary airflow guiding structure according to claim 1, characterized in that, The thickness of the gathering baffle is 1mm~2.5mm.

10. The energy-saving enclosure device with a secondary airflow guiding structure according to claim 1, characterized in that, The number of converging baffles is the same as the number of original pot rack supports of the stove, and the width W of the baffle body is equal to the distance between adjacent pot rack supports.

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