Noise reduction method for steam heating device and steam heating device

Abstract

The present application discloses a noise reduction method for a steam heating device and a steam heating device, wherein the steam heating device comprises a steam generating system and a cooking cavity, wherein the steam generating system comprises a pipeline structure for conveying liquid or gas, and a steam generator is arranged on the pipeline structure; the steam generating system is started, the steam generator is used to generate steam, and a second gas is supplied to the steam generating system; a mixed gas of the second gas and the steam is passed into the cooking cavity below the liquid level for heating. The noise reduction method of the present application can mix steam with the second gas, has a simple structure, low cost, good application value, obvious noise reduction effect, and good user experience.

Description

Technical Field

[0001] The present invention relates to but is not limited to the field of kitchen appliances, and in particular to a noise reduction method for a steam heating device and a steam heating device. Background Art

[0002] Some existing steam heating devices heat water into steam through a steam generating device, and the steam enters a cooking chamber through a gas pipeline. The cooking chamber is filled with water or a mixture of water and solid food (such as a rice water mixture). The high-temperature steam is input into the water or the mixture of water and solid food for heating.

[0003] When the high-temperature steam is introduced into water or a mixture of water and solid food, a harsh noise will be emitted. Especially in the early cooking stage, the noise is particularly obvious, affecting the user experience. Summary of the invention

[0004] In order to solve the above technical problems, the embodiments of the present application provide a noise reduction method for a steam heating device and a steam heating device, which can effectively eliminate the noise generated by the passage of high-temperature steam into water or a mixture of water and solid food, thereby improving user experience.

[0005] In order to achieve the purpose of the application, an embodiment of the present application provides a noise reduction method for a steam heating device, wherein the steam heating device includes a steam generating system and a cooking cavity, wherein the steam generating system includes a pipeline structure for conveying liquid or gas, and a steam generator is provided on the pipeline structure; the steam generating system is started, the steam generator generates steam, and a second gas is supplied to the steam generating system; a mixed gas of the second gas and the steam is passed into the cooking cavity below the liquid level for heating.

[0006] In the above method, a possible embodiment includes a gas supply device, and the supplying the second gas to the steam generating system includes: sucking external gas or generating gas through the gas supply device to deliver the second gas to the steam generating system.

[0007] In the above method, a possible embodiment is that the second gas is introduced into the pipeline structure before generating the steam; or; the second gas is introduced into the steam generator when generating the steam; or; the second gas is introduced into the pipeline structure after generating the steam.

[0008] In the above method, a possible embodiment, making the mixed gas of the second gas and the steam includes: heating the fluid containing the second gas in the steam generator and outputting the mixed gas of the second gas and the steam; or; mixing the steam generated in the steam generator with the second gas delivered into the steam generator; or; mixing the second gas with the steam in the pipeline structure between the steam generator and the cooking chamber.

[0009] In the above method, a possible embodiment includes a water tank, through which the second gas is delivered to the steam generating system.

[0010] In the above method, in a possible embodiment, the volume of the second gas accounts for 0.5%-5% of the volume of the mixed gas.

[0011] In the above method, in a possible embodiment, when the temperature of the cooking cavity is greater than a preset temperature, supply of the second gas is stopped.

[0012] In the above method, in a possible embodiment, when the temperature of the cooking cavity is lower than a preset temperature, the second gas is supplied with a maximum heating power.

[0013] In the above method, in a possible embodiment, the air supply device is a self-inhaling structure, and the negative pressure formed by the flow of fluid inside the self-inhaling structure is used to inhale external gas as the second gas into the steam generating system.

[0014] In addition, the present application also proposes a steam heating device, which performs steam heating by using any of the noise reduction methods for steam heating devices described above.

[0015] Compared with the prior art, the noise reduction method of the steam heating device of the embodiment of the present application has the following beneficial effects:

[0016] 1. The noise reduction method for steam heating of the present application can well solve the problem of excessive noise when high-temperature steam is introduced below the liquid surface for cooking, so that the experience of some cooking processes is further upgraded, and it contributes to creating a quiet cooking environment. Compared with the prior art, when performing steam heating, the present application supplies a second gas to the steam generating system, and a mixed gas of the second gas and the steam is introduced below the liquid surface in the cooking cavity for heating. In this way, the mixed gas flow composed of the second gas and the steam enters the liquid or solid-liquid mixture to form countless bubbles, and the outside of the bubbles is liquid or solid-liquid mixture. The inner gas is composed of high-temperature steam and a second gas. The outside of the bubble is under the pressure of a liquid or solid-liquid mixture, and the temperature difference between the inside and the outside causes the high-temperature steam in the bubble to liquefy. The volume of the bubble shrinks under the action of the external pressure and the temperature difference between the inside and the outside. Due to the presence of the second gas, the bubble can resist the external pressure and avoid complete liquefaction of the internal gas, and can reduce the heat transfer coefficient of the bubble, thereby reducing the rate of bubble volume reduction. When it becomes difficult for the bubble to shrink, it will be more difficult for the bubble to collapse in the liquid or solid-liquid mixture, which slows down the impact released by the collapse of the bubble when the steam enters the liquid or solid-liquid mixture, thereby reducing the noise.

[0017] Other features and advantages of the present application will be described in the following description, and partly become apparent from the description, or understood by practicing the present application. The purpose and other advantages of the present application can be realized and obtained through the structures particularly pointed out in the description and the drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] The accompanying drawings are used to provide further understanding of the technical solution of the present application and constitute a part of the specification. Together with the embodiments of the present application, they are used to explain the technical solution of the present application and do not constitute a limitation on the technical solution of the present application.

[0019] Figure 1 This is a flow chart of a noise reduction method according to a specific implementation of the present application.

[0020] Figure 2 The relationship between the radius of a single bubble and the sound pressure level in the prior art is shown in FIG.

[0021] Figure 3 This is a curve showing the relationship between the radius of a single bubble and the sound pressure level after the second gas is introduced into the specific embodiment of the present application;

[0022] Figure 4 A schematic diagram of a steam heating device according to a specific embodiment of the present application, wherein the air supply device is an air blowing member, and the air blowing member is arranged on the side of the pot body;

[0023] Figure 5 A schematic diagram of a steam heating device according to a specific embodiment of the present application, wherein the air supply device is an air blowing member, and the air blowing member is arranged on the side of the pot cover;

[0024] Figure 6 This is a schematic diagram of a steam heating device according to a specific embodiment of the present application, wherein the air supply device thereof is a self-suction structure;

[0025] Figure 7 A schematic diagram of a steam heating device with a head according to a specific embodiment of the present application;

[0026] Figure 8 This is a schematic diagram of a steam heating device in which steam is transported from bottom to top in a specific embodiment of the present application;

[0027] Fig. 9 This is a schematic diagram of a pipeline structure in a cooking cavity provided with a self-inhalation structure in a specific embodiment of the present application;

[0028] Fig.10 This is a schematic diagram of a specific embodiment of the present application in which the pipeline structure in the pot cover has a self-inhalation structure;

[0029] Fig.11a For this application Figure 5 Schematic diagram of the three-dimensional structure of the self-aspirating structure;

[0030] Fig.11b For this application Figure 5 Schematic diagram of the full cross-section structure of the self-aspirating structure.

[0031] Reference numerals:

[0032] 1 pot body; 11 cooking cavity; 12 pot taking and placing area; 13 machine head;

[0033] 2 Steam generator;

[0034] 3 drainage pipe; 31 steam outlet; 32 steam nozzle;

[0035] 4 air supply device; 400 self-inhalation structure; 41 first air flow channel; 42 second air flow channel; 43 installation section; 44 contraction section; 45 upper sealing section; 46 lower sealing section; 411 gradually contracting section; 412 throat section; 413 gradually expanding section; 421 air inlet; 422 air outlet; 401 air blowing member; 402 one-way valve; 403 infusion pipeline.

[0036] 5 pipeline structure; 51 pipe body, 52 steam channel; 521 lower steam channel; 522 upper steam channel; 523 butt joint;

[0037] 6 installation cavity; 61 air intake gap;

[0038] 7 liner;

[0039] 8. Pot cover;

[0040] 9 Water tank DETAILED DESCRIPTION

[0041] In order to make the purpose, technical solution and advantages of the present application more clear, the embodiments of the present application will be described in detail below with reference to the accompanying drawings. It should be noted that the embodiments and features in the embodiments of the present application can be combined with each other arbitrarily without conflict.

[0042] In the prior art, when high-temperature steam is introduced into the liquid surface for heating, there will be obvious noise, and the lower the water temperature, the greater the noise. Figure 2 The relationship between the radius of a single bubble and the sound pressure level is shown in the figure, where the horizontal axis is the radius of the bubble (mm) and the vertical axis is the sound pressure level (db). Figure 2 It can be seen that as the bubble radius gradually decreases, the noise generated also gradually increases. When the bubble radius is less than 0.1 mm, that is, when the bubble is about to collapse and disappear, the noise increases sharply.

[0043] Take the inner tank 7 filled with room temperature water (about 23°C) as an example. When water vapor enters the room temperature water in the inner tank 7, bubbles formed by water vapor are formed in the water. The number and size of the bubbles are related to the amount of steam input, the steam temperature, the size, number, arrangement and bubble pressure of the steam outlet 31. The heat of the bubbles in the water is quickly transferred to the surrounding water, the water vapor in the bubbles turns into water, and the bubbles collapse. The bubble collapse process is constantly occurring in the inner tank 7, and noise is generated when the bubbles collapse. For example, 0.1g of water vapor is input into the inner tank 7 filled with room temperature water per second, the initial diameter of each bubble is 3mm, the initial air pressure is 1 standard atmosphere, the temperature is 100°C, and all the bubbles collapse in the room temperature water. The volume of water vapor introduced per second is 0.0001675m 3 , the volume of each bubble is 0.0000000141372m 3 , the number of bubbles that collapse per second is about 11848 in steady state. Figure 7 The change curve of , because there are a large number of bubble collapses in the inner tank 7, just produces obvious noise. In fact, the bubble collapse noise in the inner tank 7 is the most obvious noise in the steam heating working process.

[0044] This embodiment provides a method for reducing noise of a steam heating device, wherein the steam heating device comprises a steam generating system and a cooking cavity 11, wherein the steam generating system comprises a pipeline structure 5 for conveying liquid or gas, wherein the pipeline structure 5 is connected to a steam generator 2;

[0045] like Figure 1 As shown, the noise reduction method includes the following steps:

[0046] S01: starting a steam generating system, the steam generator 2 to generate steam, and supplying a second gas to the steam generating system;

[0047] S02: Passing a mixed gas of the second gas and the steam into the cooking cavity 11 below the liquid level for heating.

[0048] The steam heating device, such as Figure 4-7 As shown, it is specifically a steam rice cooker, which is an application of a steam heating device. Others may also include electric steamers, coffee machines, soy milk machines, etc.; the cooking cavity 11 is used to cook food, and can hold liquid or solid-liquid mixtures, and high-temperature steam is transported to the liquid or solid-liquid mixture for heating; the liquid or solid-liquid mixture can be water, rice water mixed food, soy milk, porridge, braised pork, coffee, soup, tea, etc.; the pipeline structure 5 can be used to transport liquid or gas, the liquid is generally used for the steam generator 2 to generate steam, and the gas is generally the generated steam or the second gas. The pipeline structure 5 can be a hard pipe or a soft pipe, such as a silicone tube or a metal tube. The front end of the pipeline structure 5 can be connected to a water tank 9 or other water sources, the end is a cooking cavity 11, and the steam generator 2, a water pump and other structures are arranged in the middle; the front end of the pipeline structure 5 can also be the steam generator 2, which is only responsible for transporting steam, but not transporting liquid. The liquid is stored in the steam generator for heating to generate steam.

[0049] The steam generator is used to generate steam. The liquid used to generate steam can be transported into the steam generator through the pipeline structure 5, or the liquid inside the steam generator can be directly heated to generate steam.

[0050] The noise reduction method for steam heating of the present application can well solve the problem of excessive noise when high-temperature steam is introduced below the liquid surface for cooking, so that the experience of some cooking processes is further upgraded, and contributes to creating a quiet cooking environment; compared with the prior art, when performing steam heating, the present application supplies a second gas to the steam generating system, and a mixed gas of the second gas and the steam is introduced below the liquid surface in the cooking cavity 11 for heating, so that the mixed gas composed of the second gas and the steam enters the liquid or solid-liquid mixture to form countless bubbles, and the outside of the bubbles is liquid or solid-liquid mixture, The inner gas is composed of high-temperature steam and a second gas. The outside of the bubble is under the pressure of a liquid or solid-liquid mixture, and the temperature difference between the inside and the outside causes the high-temperature steam in the bubble to liquefy. The volume of the bubble shrinks under the action of the external pressure and the temperature difference between the inside and the outside. Due to the presence of the second gas, the bubble can resist the external pressure and avoid complete liquefaction of the internal gas, and can reduce the heat transfer coefficient of the bubble, thereby reducing the rate of bubble volume reduction. When it becomes difficult for the bubble to shrink, it will be more difficult for the bubble to collapse in the liquid or solid-liquid mixture, which slows down the impact released by the collapse of the bubble when the steam enters the liquid or solid-liquid mixture, thereby reducing the noise.

[0051] In addition, the second gas can be air, or a gas whose physical property is that it is less likely to change phase, condense or dissolve in a liquid or solid-liquid mixture than high-temperature water vapor, or a gas whose chemical property is that it is less likely to react with water. In actual use, the second gas should also be a gas that does not affect the cooking effect, taste, human health, etc. of food. In this embodiment, air is preferred. The second gas is formed by using air, and no additional preparation is required, so the acquisition cost is low, and it will not affect the cooking effect, taste, and human health of food. At the same time, it is not easy to change phase or condense at normal temperature and pressure.

[0052] In order to supply the second gas, the supplying the second gas to the steam generating system comprises:

[0053] External gas or generated gas is sucked in through the gas supply device 4 to deliver the second gas to the steam generating system.

[0054] The gas supply device 4 may be an air pump or a fan, which sucks in external air to deliver the second gas to the steam generating system. The air pump or fan structure can be well controlled automatically. For example, by connecting the air pump or fan structure to a control system, the delivery of the second gas can be completed in certain stages of cooking, and the amount of the delivered second gas can be well adjusted by adjusting the power of the air pump or the speed of the fan to avoid the heating efficiency being reduced due to the continued introduction of the second gas when there is no water in the cooking cavity 11.

[0055] The gas supply device 4 may also be a self-inhalation structure 400, through which external gas is used to deliver the second gas to the steam generation system. The self-inhalation structure 400 may simplify the structure and reduce the cost, making the whole structure more compact.

[0056] As a preferred embodiment of the present application, the second gas can be prepared by the gas supply device 4, such as by an oxygen generator, a carbon dioxide generator, etc., through the chemical reaction or physical reaction of certain substances to generate gas to deliver the second gas to the steam generation system. This method is suitable for implementation in some scenarios with high hygiene requirements during cooking or steam heating, for example, some food materials need to be oxidized faster, etc. This is to use an oxygen generator to prepare high-purity oxygen and high-temperature steam to pass it below the liquid surface, which can complete the oxidation of the food materials and also complete the noise reduction.

[0057] In a preferred embodiment, Figure 4 As shown, the steam generator 2 of the steam generation system quickly generates high-temperature steam through input water. At this time, the pipeline structure 5 includes a liquid delivery pipeline 403 located at the front section of the steam generator 2 and a gas delivery pipeline (i.e., steam channel 52) located at the rear section of the steam generator 2.

[0058] In this way, when the second gas is input into the steam generating system, it can be introduced into the pipeline structure 5 before the steam is generated. In other words, the second gas is introduced into the liquid. In this way, the liquid entering the steam generator 2 will be mixed with the second gas to achieve "gas-liquid mixing" - the second gas is mixed with the liquid in the liquid delivery pipeline 403. After entering the steam generator 2, the liquid is heated and liquefied to form water vapor, while the second gas is still the second gas after heating. At this time, the high-temperature steam generated by the steam generator 2 contains the second gas, and the steam with the second gas is fully mixed in the rear pipeline structure 5 to ensure the uniformity of the second gas and the high-temperature steam, thereby ensuring that the proportion of the second gas in each bubble heated below the liquid surface is uniform, thereby ensuring a good noise reduction effect.

[0059] The means of introducing steam into the pipe structure 5 before generating steam may be:

[0060] (1) An external air pump is connected to the front section of the infusion pipeline 403, and the air pump is used to pump gas into the infusion pipeline 403. The air pump can also be a fan. To avoid backflow, a one-way valve can be set on the pipeline where the air pump or fan is set. By sending air through the air pump or fan, air can be pumped into the liquid smoothly, and the pumping amount and timing of the gas can be adjusted according to actual needs, thereby achieving precise control.

[0061] (2) A self-priming structure is provided on the liquid infusion pipeline 403. When the liquid flows through the self-priming structure, negative pressure is generated, and self-priming is achieved through the negative pressure. The self-priming structure can achieve self-priming, has a simple structure, and is low in cost.

[0062] (3) The second gas is delivered to the steam generation system through the water tank 9; for example, the second gas is delivered through the water outlet connected to the water tank 9 and the liquid infusion pipeline 403, and specifically, the second gas can be injected into the water tank 9 through an air pump. By delivering the second gas through the water tank 9, there is no need to improve the existing steam generation system, and it is convenient to upgrade the old product.

[0063] In some preferred embodiments, the second gas is introduced into the steam generator 2 when the steam is generated. In the process of the steam generator 2 heating the liquid, the liquid is heated to become steam, so the second gas can also be introduced into the steam generator 2; this is suitable for some steam generating systems that do not have a liquid infusion pipeline 403 at the front end. Of course, some steam generating systems that have a liquid infusion pipeline 403 at the front end can also use the second gas introduced from the steam generator 2. After entering the steam generator 2, it can be "gas-liquid mixing" - the second gas is mixed with the liquid water in the steam generator 2, or it can be "gas-steam mixing" - the second gas is mixed with the high-temperature steam in the steam generator 2. The means of introducing the second gas can still be achieved by using an air pump, a fan, self-suction, self-generated gas supply, etc., which will not be repeated here.

[0064] In some preferred embodiments of the present application, the second gas is introduced into the pipeline structure 5 after the steam is generated. In other words, the second gas is introduced into the gas pipeline between the steam generator 2 and the cooking chamber 11 to achieve "gas-steam mixing" - the second gas is mixed with the high-temperature steam in the gas pipeline. "Gas-steam mixing" is easier than "gas-liquid mixing" and does not affect the normal operation of the steam generator 2, and can ensure the continuous generation of high-temperature steam with a stable flow rate. As for the generation method of the second gas, "gas-steam mixing" can also be achieved by using an air pump, a fan, self-priming, self-generated gas supply, etc., which will not be repeated here.

[0065] Depending on the second gas delivery position, the mixing position, duration and temperature of the second gas and steam are also different. Generally speaking, in order to ensure that the introduced second gas and high-temperature steam are evenly mixed, the second gas should be mixed with the high-temperature steam for a longer time, so that the noise reduction effect is better.

[0066] In a possible implementation manner, the mixed gas of the second gas and the steam comprises:

[0067] Mixing of the second gas and steam is performed in the steam generator 2;

[0068] The steam and the second gas begin to mix in the steam generator 2. Since there is a gas pipeline between the steam generator 2 and the cooking chamber 11, the mixing time is the longest at this time, and the ratio of the second gas and steam in each bubble formed by the mixed gas transported below the liquid surface is more uniform. At the same time, the mixing is carried out in the steam generator 2, so that the second gas is also heated by the steam generator 2, avoiding the problem of reduced heating efficiency caused by the temperature drop of the mixed gas input below the liquid surface due to the large temperature difference between the second gas and the steam, and taking into account both the noise reduction effect and the heating effect. The second gas in the steam generator 2 can be input before the steam generator 2 or on the steam generator 2, as mentioned above, and will not be repeated here.

[0069] According to whether the steam generator 2 heats the second gas, there are two specific methods:

[0070] (1) heating the fluid containing the second gas in the steam generator 2 and outputting a mixed gas of the second gas and steam;

[0071] (2) The steam generated in the steam generator 2 is mixed with the second gas transported into the steam generator 2.

[0072] The former will not reduce the heating efficiency, while the latter will not affect the normal operation of the steam generator 2, thereby ensuring the stable steam output and uniform flow rate of the steam generator.

[0073] At the same time, in addition to mixing in the steam generator 2, mixing can also be performed in the gas pipeline. As described above, when the liquid containing the second gas is heated in the steam generator 2 to generate high-temperature steam, the working temperature of the steam generator 2 decreases, and there is a risk of dry burning, which affects the life of the steam generator. To this end, a preferred embodiment is that the mixed gas of the second gas and the steam includes:

[0074] The second gas is mixed with steam in the pipe structure 5 between the steam generator 2 and the cooking chamber 11 .

[0075] At this time, the normal operation of the steam generator 2 is not affected, so that the steam output temperature and flow rate are balanced. The mixing time depends on the length of the gas pipeline. If a more uniform mixed gas is to be obtained, the position where the second gas is input can be set as far away from the cooking chamber 11 as possible.

[0076] In addition, at the beginning of cooking, the temperature of the liquid in the cooking cavity 11 is low, the temperature difference between the steam and the liquid is large, the condensation speed is fast, and the bubble collapse speed generated by the steam entering the liquid is also fast, and the noise generated at this time is relatively large. In the prior art, in order to reduce the noise at the beginning of cooking, some steam cooking appliances usually control the steam generator 2 to operate at a lower power at the beginning of cooking to reduce the condensation effect of the steam. When the temperature of the liquid in the pot rises, high-power cooking is adopted. Therefore, the amount of steam input into the cooking cavity 11 at the beginning of cooking is small, and the heating efficiency is low. However, the present application reduces the noise of liquid collision and bubble collapse in the cooking cavity 11 by mixing gas into the steam. Therefore, the steam cooking appliance of the present application reduces the limitation of power on the cooking program design, allowing the steam cooking appliance to perform high-power steam heating when the temperature in the cooking cavity 11 is low at the beginning of cooking, simplifying the overall operation program and improving the heating efficiency. To this end, in some preferred embodiments, the following steps are performed:

[0077] When the temperature of the cooking cavity 11 is greater than a preset temperature, the supply of the second gas is stopped;

[0078] When the temperature of the cooking cavity 11 is lower than a preset temperature, the second gas is supplied and the heating power is maximum.

[0079] The preset temperature can be 0-100 degrees, preferably 80-98 degrees. At this time, the water level rises to a relatively high temperature, the noise is relatively small, and the second gas supply can be stopped. When it is less than the preset temperature, the second gas is supplied, and the heating power is maximum. At this time, it can be the rated power of the heating device. The temperature of the cooking cavity 11 can be obtained by a temperature sensor, and the temperature sensor can be a top sensor or a bottom sensor.

[0080] As a preferred embodiment of the present application, the volume of the second gas accounts for 0.5%-5% of the volume of the mixed gas. This ratio can also be converted into the ratio of the second gas to steam in the output mixed gas.

[0081] When the volume of the second gas accounts for 0.5%-5% of the volume of the mixed gas, it can ensure that the second gas effectively prevents the rate of decrease in the volume of the bubbles, while also ensuring the heating efficiency of the steam cooking appliance and the amount of steam introduced, so that the steam has a better heating effect on the food in the cooking cavity 11, avoiding excessive introduction of the second gas, which leads to a reduction in the amount of steam introduced into the cooking cavity 11 and a decrease in the temperature of the steam, thereby affecting the heating efficiency.

[0082] Experiments have shown that when the volume of the input second gas accounts for 0.5% of the volume of the mixed gas, the heat transfer coefficient on the surface of the bubbles formed by the mixed gas in the liquid in the cooking chamber 11 is reduced by 50%, the heat transfer between the bubbles and the liquid is slower, the condensation rate of the steam in the bubbles is lower, the rate at which the bubble volume shrinks is slower, the squeezing force of the liquid around the bubbles on the bubbles is smaller, the collision speed of the liquid is lower, and the noise generated by the liquid collision is smaller.

[0083] When the volume of the input second gas accounts for 5% of the volume of the mixed gas, the heat transfer coefficient on the surface of the bubbles formed by the mixed gas in the liquid in the cooking chamber 11 is reduced by 90%, the heat transfer between the bubbles and the liquid is slow, the condensation rate of the steam in the bubbles is greatly reduced, the rate at which the bubble volume shrinks is slow, the squeezing force of the liquid around the bubbles on the bubbles is small, the collision speed of the liquid is low, and the liquid collision produces a weak sound that is basically imperceptible to the human ear.

[0084] Furthermore, by introducing the second gas with different volume fractions, after the bubbles disappear, 0.5%-5% of the second gas still exists, and this part of the second gas prevents the volume of the bubbles from continuing to decrease, thereby avoiding violent collision of the liquid. Preferably, after the steam condenses and disappears, the radius of the sphere formed by the second gas is greater than 1 mm, that is, the second gas prevents the radius of the bubble from decreasing to less than 1 mm, so as to avoid noise increase.

[0085] like Figure 3 The curve of the relationship between the radius of a single bubble and the sound pressure level when there is 2% air in the bubble is shown. For a bubble with a diameter of 3 mm and the remaining 2% of the second gas, its volume at one atmosphere is 0.000000000282744m 3 The diameter is 0.40716264mm. At this time, the remaining 2% prevents the bubble from decreasing. The diameter of the bubble is not close to 0, which reduces the noise. In general, when the bubble contains a second gas, the actual collapse of the bubble is more complicated. First, the condensation heat transfer coefficient of the bubble will decrease with the increase of the content of the second gas. Second, the bubble diameter has a repeated process of decrease-rebound-decrease during the collapse of the bubble. Experiments show that when a small amount of air is introduced into the water vapor, the noise can be significantly reduced. When the volume fraction of the introduced air reaches 2% of the water vapor, the noise is significantly reduced and is basically imperceptible to the human ear during cooking.

[0086] The present application also proposes a steam heating appliance that can perform the noise reduction method of a steam heating device for steam heating, including a steam generating system and a cooking chamber 11, wherein the steam generating system includes a pipeline structure 5 for conveying liquid or gas, and the pipeline structure 5 is connected to a steam generator 2.

[0087] In this application, if Figure 4-7 As shown, the pipeline structure 5 of this embodiment includes a drainage pipe 3 arranged in the cooking cavity 11, the drainage pipe 3 extends from top to bottom into the cooking cavity 11, the drainage pipe 3 is provided with a steam outlet 31, the steam outlet 31 is located below the liquid level in the cooking cavity 11, and the steam is transported from top to bottom into the cooking cavity 11, so as to heat the solid or solid-liquid mixture by the high-temperature steam;

[0088] It should be noted that the present application does not specifically limit the structure of the steam heating device. The present application is a steam rice cooker, and it can also be an electric steamer, a coffee machine, an electric rice cooker, etc. In a specific embodiment, Figure 6As shown, the steam heating device has an inner pot 7, and the cooking cavity 11 is formed in the inner pot 7. The steam cooking utensil also includes a pot cover 8 covering the pot body 1 to close the cooking cavity 11. The drainage pipe 3 is arranged on the pot cover 8. At this time, the pipeline structure 5 includes the drainage pipe 3, a lower steam channel 521 on one side of the pot body 1 and an upper steam channel 522 on the pot cover 8, and a docking joint 523 for connecting the lower steam channel 521 and the upper steam channel 522. When the pot cover 8 is covered on the pot body 1, the upper and lower steam channels 521 are docked. When the pot cover 8 is separated from the pot body 1, the upper and lower steam channels 521 are separated. At this time, the self-inhalation structure 400 can be set at any position of the pipeline structure 5, such as in the pot body 1, in the pot cover 8, or on the drainage pipe 3. In another specific embodiment, as Figure 7 As shown, the pot body 1 is provided with a pot taking and placing area 12, the pot taking and placing area 12, the steam heating device has an inner pot 7, the inner pot 7 is placed in the pot taking and placing area 12, the pot body 1 also includes a head 13 located above the pot taking and placing area 12, a pot cover 8 is provided on the inner pot 7, a drainage pipe 3 is provided on the pot cover 8, and extends from top to bottom into the cooking cavity 11, the head 13 is connected to the pot cover 8 of the inner pot 7, the pipeline structure 5 includes a channel arranged in the pot body 1, the head, and the pot cover 8, and the drainage pipe 3 in the inner pot 7, the steam sequentially passes through the above-mentioned channel and the drainage pipe 3 to send the high-temperature steam of the head 13 to below the liquid level of the food in the inner pot 7 for heating; of course, the steam heating device can also be other structures.

[0089] At the same time, if Figure 8 As shown, the steam heating device can also be an electric steamer with bottom air intake. In a specific embodiment, it includes a cooking cavity 11 and a pipeline structure 5 arranged in the pot body 1. The upper cover of the cooking cavity 11 is provided with a pot cover 8. The pipeline structure 5 includes a channel in the pot body 1 and a steam nozzle 32 arranged on the bottom side of the cooking cavity 11. The steam nozzle 32 is provided with at least one steam outlet 31; of course, the steam can also be transported at other positions of the cooking cavity 11, such as on the side wall, and a gas supply device 4 is provided at the bottom for transporting the second gas. Of course, the present application does not limit the structural form of how the pipeline structure 5 transports steam to the liquid or solid-liquid mixture.

[0090] As a preferred embodiment of the present application, the supply of the second gas is achieved through the gas supply device 4, such as Figure 4 As shown, the steam cooking appliance is provided with a pipeline structure 5 connecting the steam generator 2 and the steam outlet 31, and the air supply device 4 includes an air blower 401, which can be an air pump or a fan, and the air outlet of the air blower 401 is connected with the pipeline structure 5, and the air blower 401 is used to pump air into the pipeline structure 5. In some embodiments, a one-way valve 402 is further provided to prevent steam from flowing back into the air blower.

[0091] The air is pumped by the air blowing member 401, and the pumped air is easy to obtain. The air blowing member 401 for producing air is relatively cheap, which reduces the production cost. Moreover, the air is introduced into the cooking cavity 11, which does not affect the cooking effect and taste of the food, thereby ensuring the cooking effect of the food. The air blowing member 401 may be an air pump, a blower, etc., which is not specifically limited here.

[0092] Of course, the gas supply device 4 may also be of other types to deliver the second gas to the pipeline structure 5. For example, the gas supply device 4 may also be an oxygen generator to deliver oxygen to the pipeline structure 5.

[0093] This embodiment does not specifically limit the location of the gas-blowing member 401. In a specific embodiment, Figure 5 As shown, the steam cooking appliance further comprises a pot cover 9 covering the pot body 1, and the air blowing member 401 is arranged on the pot cover 9. In another specific embodiment, as Figure 1 As shown, the air-blowing member 401 is arranged on the pot body 1. Compared with the method of being arranged on the pot cover, this embodiment reduces the weight of the pot cover, making it easier for the user to take the pot cover, and allows the air pumped by the air-blowing member 401 to mix with the steam as early as possible, so that the two are fully mixed, avoiding stratification of air and steam and affecting the noise reduction effect.

[0094] In addition, the air supply device 4 can also be a self-inhalation structure 400, as follows;

[0095] like Figure 6 As shown, a self-inhalation structure 400 is provided on the drainage tube 3, and the steam channel 52 includes a first airflow channel 41 formed in the self-inhalation structure 400, and the first airflow channel 41 is used to transport steam; a second airflow channel 42 is provided on the self-inhalation structure 400, and the second airflow channel 42 is used to transport a second gas; after the steam is mixed with the second gas, it is transported to the liquid or solid-liquid mixture of the cooking cavity 11 through the drainage tube 3 for heating.

[0096] The following is a detailed description of the noise reduction process with the accompanying drawings:

[0097] As a preferred embodiment of the present application, the second airflow formed by the second gas is sucked into the first airflow channel 41 by the negative pressure generated by the steam airflow formed by the steam, such as Figure 6 , Fig. 9The diagram illustrates a structure of the first air flow channel 41 inside the self-inhalation structure 400. Specifically, the first air flow channel 41 includes a tapered section 411, a throat section 412 and a gradually expanding section 413. The tapered section 411, the throat section 412 and the gradually expanding section 413 are connected in sequence. The diameter of the gradually expanding section 413 gradually increases from the side of the throat section 412 to the side away from the throat section 412, and the diameter of the tapered section 411 gradually decreases from the side away from the throat section 412 to the side close to the throat section 412. When the steam enters the first air flow channel 41 and passes through the throat section 412, the steam will accelerate when it flows to the throat section 412 because the diameter of the throat section 412 is smaller than the diameter of the inlet side of the first air flow channel 41. According to Bernoulli's principle, the speed of the air flow increases and the pressure decreases. At this time, a negative pressure environment is formed near the throat section 412 and the gradually expanding section 413, so that the air outside the self-inhalation structure 400 flows from the second air flow channel 42 to the first air flow channel 41 under the action of the air pressure difference, completing natural suction without the need to set up an additional air pumping device, thereby simplifying the internal structure of the steam cooking appliance and contributing to miniaturization.

[0098] In addition, the steam ejected from the steam outlet 31 is subjected to water pressure, and the local pressure loss coefficient is greater than 1. Therefore, preferably, a gradually expanding section 413 is provided on the steam outlet side of the throat section 412, and the size of the gradually expanding section 413 gradually increases from the side of the throat section 412 to the side away from the throat section 412. In this way, the fluid can be gradually decelerated, the turbulence is reduced, and the pressure head loss is small. In some embodiments, the gradually contracting section 411 may not be provided, and a sudden contraction section may be provided, and the present application does not impose any restrictions on this.

[0099] The self-inhalation structure 400 is at a preset distance from the steam outlet 31 of the drainage tube 3, which can facilitate the full mixing of the second gas and the steam, and ensure that the mixed gas is introduced into the cooking cavity 11 when the second gas and the steam are completely mixed, so as to ensure that the second gas and the steam are evenly mixed in the bubbles formed by the contact between the mixed gas and the liquid, thereby avoiding stratification of the second gas and the steam, affecting the quality of the mixed gas, and further affecting the noise reduction effect.

[0100] The second airflow channel 42 includes an air inlet 421 located outside the self-inhalation structure 400, and an air outlet 422 located inside the self-inhalation structure 400 and connected to the first airflow channel 41. The external second gas is sucked in through the air inlet 421 and enters the first airflow channel 41 from the air outlet 422. The air outlet 422 is located on the throat section 412 or the gradually expanding section 413, so that the pressure of the air outlet 422 is lower than the pressure of the air inlet 421, forming a negative pressure difference, so that the second airflow is formed in the second airflow channel 42, mixed with the steam in the first airflow channel 41, and the steam is prevented from flowing out of the second airflow channel 42.

[0101] like Fig. 9 As shown, the angle between the outlet direction of the second airflow at the outlet 422 and the flow direction of the steam airflow in the first airflow channel 41 is an acute angle. In this embodiment, the angle between the airflow direction of the outlet 422 and the flow direction of the steam airflow is 65°. In some embodiments, the second airflow channel 42 can be tilted or bent, which is not limited. Since the angle between the outlet direction and the steam airflow is an acute angle, the flow direction of the steam airflow and the airflow direction of the second airflow do not interfere with each other, and the second airflow can enter the first airflow channel 41 more smoothly under the inertia of the steam airflow, thereby increasing the air intake and mixing effect.

[0102] like Figure 6 As shown, in this embodiment, the self-inhalation structure 400 is arranged in the pipeline structure 5 in the cooking cavity 11. Specifically, the pipeline structure 5 is a drainage pipe 3, which is detachably arranged in the pot cover 8. The self-inhalation structure 400 is located in the upper section of the drainage pipe 3 to inhale the second gas in advance. The drainage pipe 3 can be arranged integrally with the self-inhalation structure 400, or can be arranged separately. The self-inhalation structure 400 has a mounting section 43 detachably connected to the pot cover 8, and is connected to the pot cover 8 through the mounting section 43. The cooking cavity 11 includes a lower space below the liquid level or solid-liquid mixture and an upper space above the liquid level. The air inlet 421 of the second air flow channel 42 is connected to the upper space, and the second gas is the gas in the upper space. During the cooking process, the upper space of the cooking cavity 11 is filled with air and steam, the lower space is liquid or a solid-liquid mixture, and the upper space is located on the inner side of the cooking utensil and in the cooking cavity 11. Therefore, the temperature of the gas is higher than that of the atmosphere outside the heating utensil. Therefore, the self-inhalation structure 400 located in the cooking cavity 11 inhales the second gas from the upper space, which can reduce energy loss and improve cooking efficiency. Therefore, in this embodiment, the self-inhalation structure 400 is preferably set on the drainage pipe 3.

[0103] In some alternative embodiments, such as Fig.10 , 11aAs shown in 11b, the self-inhalation structure 400 is arranged on the pipeline structure 5 of the pot cover 8. In this case, the self-inhalation structure 400 can be formed separately, and the structure is simpler. It is arranged on the pipeline structure 5 of the pot cover 8, so that the self-inhalation structure 400 can be farther away from the steam outlet 31, and the inhaled second gas can have sufficient time and path to mix with the steam to ensure uniform mixing and improve the noise reduction effect. At this time, in order to facilitate installation, the pot cover 8 is provided with a mounting cavity 6, and the self-inhalation structure 400 is nested in the mounting cavity 6 and docked on the pipeline structure 5 up and down. It is preferably made of flexible silicone material to facilitate the sealing between the self-inhalation structure 400 and the pipeline structure 5 or the pot cover 8 to avoid steam leakage. In order to facilitate the second air flow channel 42 to inhale the second gas, a contraction section 44, an upper sealing section 45 and a lower sealing section 46 are provided on the outside of the self-inhalation structure 400, and the air inlet 421 is arranged on the contraction section 44. The outer diameter of the contraction section 44 is smaller than the outer diameters of the upper sealing section 45 and the lower sealing section 46 at both ends of the self-inhalation structure 400. In this way, the sealing with the installation cavity 6 can be achieved by mixing the upper sealing section 45 and the lower sealing section 46 at both ends. Through the contraction section 44 in the middle, an air intake gap 61 can be formed between the outer side of the self-inhalation structure 400 and the installation cavity 6. There is air in the air intake gap 61, and the air inlet 421 is arranged on the air intake gap 61 to facilitate air intake.

[0104] In some preferred embodiments of the present application, a self-inhalation structure may be provided in the liquid delivery pipeline 403 , and a self-inhalation structure may also be provided on the steam generator 2 .

[0105] Of course, the gas supply device 4 can also be a self-generating gas supply device, such as an oxygen supply machine, etc., which can be arranged on the front pipe structure, the rear pipe structure or the steam generator 2 according to specific circumstances.

[0106] In the description of this application, the terms "install", "connect", "connect", "fix" and the like should be understood in a broad sense. For example, "connect" can be a fixed connection, a detachable connection, or an integral connection; it can be a direct connection or an indirect connection through an intermediate medium. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0107] In the description of this specification, the description of the terms "one embodiment", "some embodiments", "specific embodiments", etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present application. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0108] Although the implementation methods disclosed in this application are as above, the contents are only implementation methods adopted to facilitate understanding of this application, and are not intended to limit this application. Any technician in the field to which this application belongs can make any modifications and changes in the form and details of implementation without departing from the spirit and scope disclosed in this application, but the scope of patent protection of this application shall still be based on the scope defined by the attached claims.

Claims

1. A method for reducing noise of a steam heating device, wherein the steam heating device comprises a steam generating system and a cooking chamber, wherein the steam generating system comprises a pipeline structure for conveying liquid or gas, and the pipeline structure is connected to a steam generator; characterized in that: starting a steam generating system, the steam generator to generate steam, and supplying a second gas to the steam generating system; A mixed gas of the second gas and the steam is introduced into the cooking cavity below the liquid level for heating.

2. The noise reduction method for a steam heating device according to claim 1, characterized in that: Comprising a gas supply device, the supplying of the second gas to the steam generating system comprises: External gas or generated gas is sucked in through the gas supply device to deliver the second gas to the steam generating system.

3. The noise reduction method for a steam heating device according to claim 2, characterized in that: The second gas is introduced into the pipeline structure before generating the steam; or; The second gas is introduced into the steam generator when generating the steam; or; The second gas is introduced into the pipeline structure after the steam is generated.

4. The noise reduction method for a steam heating device according to claim 1, characterized in that: The mixed gas of the second gas and the steam comprises: heating the fluid containing the second gas in the steam generator and outputting a mixed gas of the second gas and steam; or; mixing the steam generated in the steam generator with a second gas fed into the steam generator; or; The second gas is mixed with steam in a conduit structure between the steam generator and the cooking cavity.

5. The noise reduction method for a steam heating device according to claim 1, characterized in that: A water tank is included, through which the second gas is delivered to the steam generating system.

6. The noise reduction method for a steam heating device according to claim 1, characterized in that: The volume of the second gas accounts for 0.5%-5% of the volume of the mixed gas.

7. The noise reduction method for a steam heating device according to claim 1, characterized in that: When the temperature of the cooking cavity is greater than a preset temperature, supply of the second gas is stopped.

8. The noise reduction method for a steam heating device according to claim 1, characterized in that: When the temperature of the cooking cavity is lower than a preset temperature, the second gas is supplied with maximum heating power.

9. The method for reducing noise of a steam heating device according to claim 2, characterized in that: The air supply device is a self-inhaling structure, which uses the negative pressure formed by the flow of fluid inside the self-inhaling structure to inhale external gas as the second gas into the steam generating system.

10. A steam heating device, characterized in that: Steam heating is performed by the noise reduction method for a steam heating device according to any one of claims 1 to 9.

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