Energy-saving pot rack for round-bottom frying pot

Abstract

The invention provides an energy-saving pot rack suitable for using a round-bottom frying pot, the energy-saving pot rack is suitable for a household gas stove provided with a gas control basin, the energy-saving pot rack comprises a round straight ring and a conical ring extending upwards from the round straight ring, and a plurality of pot feet are arranged on the upper portion of the conical ring after the upper portion of the conical ring is flanged. According to the energy-saving pot rack, pot foot grooves can be formed in the lower portion of the round straight ring, and the positions of the pot foot grooves correspond to the positions of pot feet on the gas stove. After the energy-saving pot rack ring is used, equivalently, the edge of the air control basin extends upwards and inwards to the edge of a round-bottom pot, so that the air control and heat preservation effects are achieved. The gas-saving pot has the advantages that the diameter of the pot bottom in contact with the pot feet is large, and the pot can be placed stably. And 2, the outlet gap is fixed and high, has an air draft effect like a chimney, and has basically the same working point for all round-bottom pots of 26-40 centimeters.

Description

Technical Field

[0001] The invention relates to an energy-saving pot rack, which is suitable for placing a round-bottomed cooking pot on a household gas stove equipped with a gas control basin. Background Art

[0002] The basic structure of a gas stove has remained largely unchanged. It's always an atmospheric burner. Gas is injected into the burner's inlet pipe, mixed with primary air, and then passed to the ignition distributor on the burner. It then exits through the flame hole in the ignition distributor's fire cap, where it mixes with secondary air before burning. Cooking occurs with the flame fully exposed to the air. Modern gas stoves have only seen minor improvements in appearance, materials, ignition, and safety, but the basic structure remains unchanged, resulting in lower thermal efficiency.

[0003] The inventors have found through long-term research and development that the main reasons for low thermal efficiency are four aspects:

[0004] 1. Most existing gas stove burners feature two flame rings: an inner and outer ring. These are known as two-ring burners. The outer ring's flame holes project flames diagonally upward, with a diameter of approximately 110-120 mm. This design wastes the heated area of the pot bottom between the inner and outer flames, concentrating the outer flames in a narrow circle. While this burner exhibits high thermal efficiency during flame detection, it exhibits extremely low thermal efficiency when used in a Chinese round-bottomed wok, resulting in poor cooking results.

[0005] The root cause of this phenomenon lies in thermal efficiency testing standards that are out of touch with China's realities. Current national testing standards, based on international standards, use large frying pans with a diameter of over 30 centimeters for testing. Because the flame is ejected close to the pan's bottom, the flame velocity is high, resulting in a higher heat transfer coefficient. Even if some heated area is wasted in the center, it represents a relatively small percentage of the pan's base. Furthermore, while this wasted area is in the center, it effectively reduces the heat intensity to the lowest area of the pan's base. Therefore, it has little impact on overall thermal efficiency, resulting in a higher measured thermal efficiency value.

[0006] Most household pots, however, are small, just over 20 centimeters in diameter. This is especially true in China, where electrical appliances are often used for boiling water and cooking, while gas stoves are primarily used for stir-frying. Households typically cook smaller portions; a typical large bowl of food, weighing approximately 500 grams, occupies only about 20 centimeters of the pot's diameter. The broth, even smaller, is concentrated in the center of the pot. Because the round bottom curves upward, the outer flames projecting diagonally upwards from the outer ring have a contact diameter of approximately 150 centimeters at the pot's base. This effectively burns only the edges of the dish, ignoring the broth, leaving only the center, which is a low flame. This significantly reduces thermal efficiency. During cooking, the edges of the dish often burn while the broth in the center remains unboiled. This necessitates repeated opening and stirring, which not only causes significant heat loss but also prolongs cooking time, wastes gas, and is extremely difficult to cook.

[0007] There are also spiral stoves on the market, where the outer flame is ejected tangentially along the circumference. Increasing the tangential flame velocity is useless; only increasing the normal flame velocity and thinning the flame layer can improve the heat transfer coefficient and thus thermal efficiency. Therefore, while the heat is concentrated in the center, the flame is weak, the normal flame velocity is low, and the thermal efficiency is also low. Nine-burner stoves, which have been released in recent years, also have dispersed flames. While these two stoves are not very efficient in practical cooking, they offer more evenly distributed heat than two-ring stoves, making cooking easier.

[0008] There are also infrared stoves that are modified to mix the air only once to improve thermal efficiency, but in fact it is unreasonable. In addition, there are major defects such as fine fire holes, inability to clean after clogging, and short lifespan, so they have been basically eliminated.

[0009] 2. Every time a gas stove starts cooking, it wastes some heat to heat the burner, stovetop, and other components. This is called thermal inertia. The heavier the burner, the greater the thermal inertia, and the more heat is wasted. Current burners are made of brass (previously, they were cast iron, which is prone to rust). For example, a 300-gram burner, heated to a constant temperature of approximately 300°C, consumes roughly the same amount of heat as boiling 80 grams of water. For a household gas stove that only takes a few minutes to cook a single bowl of food, using about 500 grams of water, this represents a significant amount of waste. Therefore, the lower the thermal inertia, the better.

[0010] Current national standards don't measure thermal inertia or the thermal efficiency of round-bottomed woks. However, manufacturers should strive to produce gas stoves with low thermal inertia and high thermal efficiency using round-bottomed woks to truly contribute to energy conservation and emissions reduction. Our own rough test method uses the same round-bottomed iron pan, starting from cold, to boil 500g or 1000g of water at room temperature. We compare the time and gas consumption of each stove, providing a rough comparison of the actual thermal efficiency of various gas stoves.

[0011] 3. The flame burns when exposed to the air, and loses a lot of heat due to contact and mixing with too much air outside.

[0012] 4. About 30% of the heat in a flame is radiated by infrared rays, most of which is radiated downward and outward and is wasted.

[0013] In 1997, the inventors discovered the aforementioned flaws (1) and (2) while using a two-ring burner stove. They subsequently developed a straight-burner gas stove with a thin-walled stainless steel cover weighing only approximately 80 grams. Stainless steel has poor thermal conductivity, resulting in minimal heat loss to the burner head. This reduces thermal inertia and allows for concentrated, upward-focused fire. While the straight-burner head's distance from the pot bottom and its exposure to cold air makes it slightly less efficient than a two-ring burner stove, its practical performance when used with a frying pan was significantly better than that of a conventional stove. At the time, a satisfactory thermal efficiency was sufficient, making it a popular choice among users.

[0014] Gas stove energy efficiency ratings began to be standardized in 2015, with the national standard for built-in Class 1 energy-efficiency stoves setting a thermal efficiency of 63%. This is because the 1996 edition of the national standard for household gas stoves included an unreasonable stipulation regarding thermal efficiency testing: "…the initial water temperature should be room temperature plus 5°C, and the final water temperature should be the initial water temperature plus 50°C..." This "room temperature plus 5°C" preheats the stove for several minutes, masking the shortcomings of the high thermal inertia stove cover. The 2007 edition added an even more unreasonable stipulation: "…when the temperature rises 30K above the initial temperature, turn off the gas and continue stirring. The highest temperature reached is the final temperature..." This practice allows the stove with high thermal inertia to continue transferring heat to the pot even after it is turned off, further inflating the measured thermal efficiency. The 2020 version restored the 1996 method, but added a 15-minute preheating step, making it virtually indistinguishable between cooktops with different thermal inertias. (Actually, it would have been more reasonable to use an additional electric heater or ice pack to bring the water to room temperature and then test immediately after ignition. However, because the water volume tested was so large, the difference in thermal inertia values was minimal.) Knowing that their product's energy efficiency rating was low and unable to compete, they proactively discontinued production of the product.

[0015] In 2021, the inventors further realized the third and fourth reasons for the low thermal efficiency of the above-mentioned gas stoves, and developed a "gas stove insulation furnace", with a patent application number of 2021 2 1082865.9. The flame is placed in the insulation furnace to burn, firstly, to control the secondary combustion air, prevent too much cold air from contacting the flame, and allow part of the hot exhaust gas attached to the periphery of the flame to circulate in the furnace. Secondly, infrared radiation is made on the inner wall of the furnace to increase the furnace temperature, thereby reducing heat loss, and improving the use of thin-walled stainless steel fire covers with low thermal inertia for both the inner and outer fire covers. Due to manufacturing difficulties, the official trial product was not launched until the end of 2023, and the thermal efficiency was increased to 74%. However, due to the installation of aluminum silicate insulation cotton in the insulation furnace, the large size and clumsy appearance, coupled with some other defects, the market recognition is not high.

[0016] Therefore, in May 2024, the inventor changed the design to a gas stove with gas control only and no heat preservation. The patent is named "Gas stove with gas control pot rack" and the patent application number is 202421212615.6. Although the thermal efficiency is reduced to 69%, it is still much higher than the original 63% first-level energy efficiency. It also has good practical performance and user-acceptable appearance. However, there are some drawbacks: the stainless steel burner is difficult to remove and clean, and the interior of the gas control pot rack is also difficult to clean, and it will yellow and discolor over time.

[0017] As a result, some existing household gas stoves have gradually adopted the gas control principle and improved their design to increase the detected thermal efficiency, raising the nominal detected thermal efficiency to over 68%. However, to achieve this, the diameter of the gas control basin is made larger, resulting in a large gap between the edge of the basin and the round-bottomed cooking pot. This allows cold air to flow in through the gap, making it virtually useless when the pot is actually in use. In other words, the current gas control basin is merely a selling point to improve the detected thermal efficiency, with little practical value.

[0018] See Figure 1 , Figure 1 The diagram shows the operation and structure of an existing gas stove equipped with a gas control basin, with a large frying pan and a cooking pot placed on them respectively. Figure 1 In the figure, 1 is the gas stove part, 1-1 is the gas stove surface, 1-2 is the burner, 1-3 is the pressure plate, 1-4 is the gas control basin, 1-4-1 is the gas control basin support. The pot rack 1-5 is detachably placed on the gas control basin 1-4. Figure 1 The left side of the diagram illustrates the placement of a large frying pan 2. The exhaust gas outlet, located at the height a of the pan stand foot 1-5-1, is only approximately 9-10 mm. The outflowing exhaust gas equals the total inflow of internal and external combustion gas, internal and external primary air, and internal and external secondary air. The high-temperature, viscous exhaust gas that flows along with the exhaust gas is blocked and forced to circulate only in the gas control basin, raising the temperature inside the basin and reducing heat dissipation from the flame, thereby improving thermal efficiency.

[0019] Turning to the right, a diagram illustrates the placement of a round-bottomed pot 3. The distance b between the pot bottom and the edges of the gas control basins 1-4 is large, allowing a large amount of cold air to flow in from the edges of the gas control basins. The viscous exhaust gases, heated by the flame airflow, flow out along with the combustion exhaust, carrying away the heat. Consequently, when the round-bottomed pot 3 is in use, the gas control basins 1-4 are essentially ineffective. Summary of the Invention

[0020] Based on the above background technology, the purpose of the present invention is to provide an energy-saving pot rack, which is suitable for using a round-bottomed frying pan while also allowing the gas control basin to function, thereby improving practical thermal efficiency.

[0021] According to the above-mentioned purpose, the energy-saving pot rack for a round-bottomed frying pan of the present invention is suitable for a household gas stove equipped with a gas control basin. The energy-saving pot rack is arranged on the gas control basin of the gas stove, and includes a straight circle and a conical circle extending upward from the straight circle. The upper part of the conical circle is flanged and provided with a plurality of pot feet.

[0022] In the above energy-saving pot rack, a pot foot groove is opened at the lower part of the round straight circle, and its position corresponds to the position of the pot foot on the gas stove.

[0023] The energy-saving pot support ring of this invention effectively extends the edge of the gas control basin upward and inward to the edge of the round-bottomed pot, thus controlling gas and maintaining heat. This not only increases actual heat and saves gas, but also offers two other advantages: First, the pot base, where the pot legs contact, has a larger diameter, ensuring stable pot support. Second, the fixed and high outlet gap acts like a chimney, creating a draft-drawing effect. It maintains a similar operating point for all round-bottomed pots ranging from 26 to 40 cm. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] The embodiments of the present invention will be described in detail below with reference to the accompanying drawings, in which:

[0025] Figure 1 The diagram shows the operation and structure of an existing gas stove equipped with a gas control basin, with a large frying pan and a cooking pot placed on them respectively.

[0026] Figure 2 It is a side schematic diagram of an embodiment of the present invention.

[0027] Figure 3 is a schematic diagram of another embodiment, DETAILED DESCRIPTION

[0028] See Figure 2 , Figure 2 The gas stove part 1, gas stove surface 1-1, burner 1-2, pressure plate 1-3, gas control basin 1-4 and gas control basin support 1-4-1 are shown in the figure. Figure 1 The prior art is partially identical to the prior art. The difference lies in the pot stand employing the energy-saving pot stand 4 of the present invention. The energy-saving pot stand 4 of the present invention comprises a straight ring 4-1 and a conical ring 4-3 extending upward from the straight ring 4-1. The energy-saving pot stand 4 rests concentrically on the upper edge of the gas control basin 1-4, via the outer edge of the lower portion of the straight ring 4-1. The upper portion of the conical ring 4-3 of the energy-saving pot stand 4 is flanged and then provided (for example, by welding or integral molding) with a plurality of pot feet 4-2. The round-bottomed pot 3 rests on these feet 4-2. This structure limits the distance between the inner diameter edge and the round pot bottom, effectively extending the edge of the gas control basin upward and inward to the edge of the round pot. This gas control basin serves to control air and maintain heat, not only increasing actual firepower and saving gas, but also offering two additional advantages: first, the pot bottom diameter contacted by the feet is large, ensuring stable pot placement. Second, the outlet gap is fixed and high, acting like a chimney to extract air, achieving a substantially identical operating point for all round-bottomed pots between 26 and 40 cm.

[0029] Figure 3 Another embodiment of the present invention is shown. Figure 2 On the basis of , pot foot slot 4-1A is added to adapt to the use of existing gas stoves with pot foot 1-5A welded on gas control basin 1-1A. Figure 3A pot foot groove 4-1A is formed at the bottom of the straight circle 4-1, corresponding to the existing pot foot 1-5A on the gas stove. When the energy-saving pot rack 4 of the present invention is placed on the gas stove, the pot foot groove 4-1A is snapped onto the pot foot 1-5A. Then, the round-bottomed pot 3 is placed on the pot foot 4-2.

Claims

1. An energy-saving pot stand for a round-bottomed cooking pot, suitable for use on a household gas stove equipped with a gas control basin. The energy-saving pot stand is arranged on the gas control basin of the gas stove, and is characterized in that: The pot pot comprises a straight circle and a conical circle extending upward from the straight circle. A plurality of pot feet are arranged on the upper part of the conical circle after the flange is turned.

2. The energy-saving pot rack according to claim 1, characterized in that: A pot foot groove is provided at the lower part of the straight circle, and its position corresponds to the position of the pot foot on the gas stove.

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