Oven

Abstract

According to the oven provided by the invention, the double air inlets of the fan can simultaneously bear pressure relief and heat dissipation functions, the first air inlet sucks hot air flow in the interval space, and the hot air flow is converged with high-pressure air sucked by the second air inlet and then is exhausted through the air exhaust duct. The impeller assembly is provided with a penetrating channel in the axial direction, the penetrating channel enables the space where the first impeller is located to communicate with the space where the second impeller is located, due to the fact that the air pressure generated by the first impeller is larger than that of the second impeller, the pressure difference pointing from the first impeller to the second impeller is formed in the penetrating channel, and the pressure difference can restrain airflow from entering the fan from the second air inlet. The suction force of the second impeller to the pressure relief hole is reduced, so that the situation that excessive gas carries heat to be discharged due to the fact that the suction force is too strong is avoided, heat loss of pressure relief can be effectively reduced under the condition that heat dissipation is guaranteed, and the energy efficiency of the oven is improved.

Description

TECHNICAL FIELD

[0001] The application belongs to the field of baking equipment, and more particularly relates to a baking oven. BACKGROUND

[0002] The baking oven is a kind of kitchen appliance which generates high temperature through internal heating elements to process food materials such as baking, roasting and heating, and is widely used in daily cooking at home and professional baking scenes.

[0003] During the use of the baking oven, the device needs to be cooled, and the interior needs to be depressurized. During the cooling and depressurization, part of the heat of the baking oven is discharged, which affects the energy efficiency of the baking oven, thereby resulting in low energy efficiency of the baking oven. SUMMARY

[0004] The purpose of the embodiment of the application is to provide a baking oven to solve the technical problem of low energy efficiency caused by the depressurization of the baking oven in the prior art.

[0005] To achieve the above purpose, the technical scheme adopted by the application is to provide a baking oven, which comprises:

[0006] An outer shell body; a cooling air duct is arranged in the outer shell;

[0007] An inner cavity; the inner cavity is arranged in the outer shell body, and there is a spacing space for mounting the device between the outer shell body and the inner cavity, and the inner cavity is provided with a pressure relief hole;

[0008] A fan; the fan comprises a first air inlet, a second air inlet and an air outlet, the first air inlet and the spacing space are communicated, and the second air inlet and the pressure relief hole are communicated;

[0009] An exhaust air duct; the exhaust air duct is communicated with the air outlet;

[0010] The fan further comprises an impeller assembly, and the impeller assembly comprises a first impeller and a second impeller, and the first impeller and the second impeller are coaxially arranged;

[0011] The first air inlet and the second air inlet are respectively arranged at the two ends of the axial direction of the fan, the first air inlet is opposite to the first impeller to drive the airflow from the first air inlet into the fan through the first impeller, the second air inlet is opposite to the second impeller to drive the airflow from the second air inlet into the fan through the second impeller, and the air outlet is arranged on the radial side of the fan to discharge the airflow from the fan;

[0012] The impeller assembly is provided with a through channel along the axial direction, which communicates the space where the first impeller is located and the space where the second impeller is located, the wind pressure generated by the first impeller is greater than the wind pressure generated by the second impeller, so as to form a pressure difference in the through channel, which is directed from the first impeller to the second impeller.

[0013] Optionally, the first impeller comprises a plurality of first blades arranged at intervals in a circumferential direction, and the second impeller comprises a plurality of second blades arranged at intervals in the circumferential direction; the number of the first blades is equal to that of the second blades, and each first blade is connected with a corresponding second blade to form an integrated blade, so that the first blades and the second impeller form integrated blades, and the intervals between adjacent integrated blades form the through channels.

[0014] Optionally, the impeller assembly further comprises a support member, and the plurality of integrated blades are connected to the support member.

[0015] Optionally, the support member comprises a support ring, the support ring and the integrated blades are coaxially connected, and the integrated blades extend from a radially inner side of the support ring to a radially outer side of the support ring; on the radially inner side and the radially outer side of the support ring, the through channels are respectively formed between adjacent integrated blades.

[0016] Alternatively, the support member comprises a support disc, the support disc and the integrated blades are coaxially connected, and the integrated blades extend to a radially outer side of the support disc; on the radially outer side of the support disc, the through channels are formed between adjacent integrated blades.

[0017] Optionally, a cross section of the support ring in an axial direction is elliptical, and a long axis direction of the cross section is perpendicular to the axial direction.

[0018] Optionally, the inner diameter and the outer diameter of the support ring satisfy (Q1-Q2) / 10Q3-Q4, and / or Q3-Q4<(Q1-Q2) / 2; wherein Q1 represents an outer diameter of the integrated blade, Q2 represents an inner diameter of the integrated blade, Q3 represents an outer diameter of the support ring, and Q4 represents an inner diameter of the support ring.

[0019] Optionally, an axial height of the first impeller is greater than an axial height of the second impeller.

[0020] Optionally, the axial height H1 of the first impeller and the axial height H2 of the second impeller satisfy 1 / 10≤H2 / H1≤1 / 4.

[0021] Optionally, the oven further comprises a first partition plate and a second partition plate arranged between the outer shell and the inner cavity, and the first partition plate is located on a side of the second partition plate close to the outer shell.

[0022] The first partition plate and the second partition plate form a fan cavity and an exhaust air duct, a side portion of the fan cavity forms an air outlet, and the fan cavity is in communication with the exhaust air duct through the air outlet.

[0023] The impeller assembly is arranged in the fan cavity, the first impeller faces the first partition plate, and the first air inlet is arranged on the first partition plate opposite to the first impeller; the second impeller faces the second partition plate, and the second air inlet is arranged on the second partition plate opposite to the second impeller.

[0024] Optionally, a connecting channel is provided between the second air inlet and the pressure relief hole, and the cross-sectional dimensions of the connecting channel gradually increase from the pressure relief hole to the second air inlet.

[0025] The beneficial effects of the oven provided in this application are as follows: Compared with the prior art, the oven in this application embodiment has dual air inlets for the fan, which can simultaneously perform pressure relief and heat dissipation functions. The first air inlet draws in hot airflow from the space, which merges with the high-pressure gas drawn in from the second air inlet and is then discharged through the exhaust duct. The impeller assembly has a through channel along the axial direction, which connects the spaces where the first impeller and the second impeller are located. Because the wind pressure generated by the first impeller is greater than that of the second impeller, a pressure difference is formed in the through channel from the first impeller to the second impeller. This pressure difference can inhibit airflow from entering the fan from the second air inlet, reducing the suction force of the second impeller on the pressure relief hole. This avoids excessive suction force causing excessive gas to carry heat out, thus effectively dissipating the heat from pressure relief while ensuring heat dissipation, thereby improving the energy efficiency of the oven. Attached Figure Description

[0026] To more clearly illustrate the technical solutions in the embodiments of this application, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0027] Figure 1 This is a schematic diagram of the appearance of the oven in the embodiments of this application;

[0028] Figure 2 This is a schematic diagram of the interior of the oven in an embodiment of this application;

[0029] Figure 3 This is a schematic diagram of the fan arrangement in the oven in this embodiment of the application;

[0030] Figure 4 A cross-sectional schematic diagram showing the location of the fan in the oven in this embodiment of the application;

[0031] Figure 5 This is a schematic diagram of an impeller assembly in one embodiment of this application;

[0032] Figure 6 for Figure 5 A top-view schematic diagram of the impeller assembly in the illustrated embodiment;

[0033] Figure 7 This is a schematic diagram of an impeller assembly in another embodiment of this application;

[0034] Figure 8 for Figure 7 A top-view schematic diagram of the impeller assembly in the illustrated embodiment;

[0035] Figure 9 Figure 1 is a schematic view of a first embodiment of the present application; Figure 5 Figure 2 is a partial cross-sectional view of the impeller assembly in the embodiment shown in Figure 1;

[0036] Figure 10 Figure 3 is a schematic view of an impeller assembly in another embodiment of the present application;

[0037] Figure 11 Figure 4 is a schematic view of the impeller assembly in the embodiment shown in Figure 3; Figure 10 Figure 5 is a lateral schematic view of the impeller assembly in the embodiment shown in Figure 3;

[0038] Figure 12 Figure 6 is an exploded view of the partition structure in the embodiment of the present application;

[0039] Figure 13 Figure 7 is a schematic view of the pressure relief passage of the pressure relief hole and the second air duct in the embodiment of the present application;

[0040] Figure 14 Figure 8 is a separate schematic view of the pressure relief passage in the embodiment of the present application.

[0041] In the drawings, reference numerals:

[0042] Oven 100; outer housing 1; inner cavity 2; spacing space; pressure relief hole 21; fan 3; first air inlet 31; second air inlet 32; air outlet 33; impeller assembly 34; integral blade 340; first impeller 341; first blade 3411; second impeller 342; second blade 3421; support ring 344; support disc 345; through passage 346; driving member 35; fan cavity 36; exhaust air duct 4; first partition 51; second partition 52; pressure relief passage 53; connecting buckle 531. DETAILED DESCRIPTION

[0043] In order to make the technical problems to be solved by the present application, technical solutions and beneficial effects clearer, the present application will be further described in detail below in combination with the drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and not used to limit the present application.

[0044] It should be noted that when an element is referred to as being "fixed to" or "disposed on" another element, it can be directly on the other element or indirectly on the other element. When an element is referred to as being "connected to" another element, it can be directly connected to the other element or indirectly connected to the other element.

[0045] It should be understood that the terms "length", "width", "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer" and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation of the present application.

[0046] In addition, the terms "first", "second" are only for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined with "first", "second" can explicitly or implicitly include one or more of the features. In the description of the present application, the meaning of "multiple" is two or more, unless otherwise explicitly and specifically limited.

[0047] As a commonly used household appliance, most of the main components of the oven include the shell, the heating element, the inner cavity, the temperature control system, the door body and the sealing structure, and the operation panel. The shell is the external support structure of the oven, which is usually made of cold-rolled steel plate or stainless steel material, and the surface is usually treated by powder spraying or wire drawing. Not only can it protect the internal parts from collision damage, but also can isolate the high temperature transmitted by the inner cavity to avoid accidental scalding of the user. The heating element is the core heating component of the oven, which is commonly known as an electric heating tube and a heating wire. The electric heating tube has a quartz tube, a stainless steel tube and other types, usually one set each at the top and bottom, and some ovens also have a back heating tube to generate the high temperature required for baking. The inner cavity is a closed space made of high-temperature-resistant metal, which is a place for placing food for baking. The inner wall is usually treated for anti-sticking or easy cleaning to facilitate daily cleaning. The temperature control system includes a temperature sensor and a temperature controller. The temperature sensor detects the temperature of the inner cavity, and the temperature controller adjusts the start and stop of the heating element according to the set temperature to maintain the stability of the inner cavity temperature. The door body is usually double-layer high-temperature-resistant glass, which is convenient for observing the baking state, and the door edge is provided with a sealing rubber strip, which can reduce heat and gas leakage. The operation panel is the main part of human-computer interaction, which can set temperature, time, baking mode and other parameters through knobs, buttons or touch screens.

[0048] When the oven is working, the user sets the target temperature and baking time through the operation panel, and the temperature control system starts the heating element after receiving the instruction. The heating element generates heat after being powered on, which is transmitted to the inner cavity through heat radiation and heat convection, causing the temperature of the inner cavity to gradually rise. The temperature sensor monitors the temperature of the inner cavity in real time, and when the temperature reaches the set value, the temperature controller sends a signal to cut off the power supply of the heating element to stop heating; when the temperature of the inner cavity drops below the set value, the temperature controller starts the heating element again, and this cycle continues to ensure that the temperature during baking is always maintained within the set range. During the baking process, the water in the food will vaporize to form steam, and the pressure in the inner cavity will change at this time. The pressure relief hole and other structures will play a role in helping to maintain pressure balance. When the set baking time is up, the heating element is automatically turned off.

[0049] At present, most ovens use passive pressure relief design, which usually relies on the small gap between the oven door and the cavity, or sets a simple pressure relief hole at the top of the oven body, and uses the air pressure difference to guide the gas out. The size of these gaps and pressure relief holes is usually fixed and pre-set according to the conventional use scene when the product is shipped, and cannot be adjusted according to the actual baking needs. If the gap is too wide, it will cause heat loss and affect temperature control accuracy, and if it is too narrow, the exhaust capacity will be limited. The top pressure relief hole is usually a single aperture circular hole or a grid structure, which can only rely on natural air flow to complete exhaust. This design can cope with the slow accumulation of slight pressure in the conventional baking scene, but it will immediately encounter problems in the face of special situations with sudden pressure rise.

[0050] For example, when baking food rich in moisture, such as whole roasted chicken, potatoes with skin, fresh vegetable tart, etc., high temperature can cause the water in the food to vaporize in a short time, forming a stream of steam. This sudden steam explosion can cause the pressure in the oven to rise several times in a short time. The passive pressure relief method lacks an active trigger pressure sensing mechanism, and the exhaust efficiency of natural penetration is very low, which cannot quickly balance the pressure difference between the inside and outside of the oven body in a short time. The delay of this pressure discharge not only may affect the expansion effect and taste level of the baked food, but also may cause safety hazards. Lightly, it may cause the oven door to be pushed open by the pressure, and high-temperature gas and soup may splash and scald the user. Heavy may cause deformation of the oven body sealing structure, affecting the service life of the oven, and in extreme cases, there is even a risk of cavity explosion.

[0051] Moreover, the controllability of the passive pressure relief mode has significant defects, and cannot actively control the pressure relief state according to the characteristics of the food materials and the baking stage. In the initial stage of baking that needs to maintain a certain humidity in the cavity, such as the expansion stage of making cakes, the fixed pressure relief structure will continuously discharge water vapor, resulting in insufficient humidity affecting the fluffiness of the cakes. In the final stage that needs to quickly discharge moisture, such as the crisp shaping stage of biscuits, due to the limited exhaust efficiency, the cavity cannot timely remove the excess moisture, resulting in a soft taste of the biscuits and difficulty in preservation. This passive exhaust mode without distinction in all periods cannot achieve precise pressure relief in cooperation with the baking curve of different food materials, limiting the possibility of household users to improve the baking quality.

[0052] To solve the above problems, the present application provides an oven 100, please refer to Figure 1 、 Figure 2 、 Figure 3 and Figure 4 The oven 100 in the embodiments of the present application comprises:

[0053] The outer shell 1 is provided with a heat dissipation air duct 20 inside the outer shell 1;

[0054] The inner cavity 2 is arranged in the outer shell 1, and the inner cavity 2 is provided with a pressure relief hole 21;

[0055] The fan 3 comprises a first air inlet 31, a second air inlet 32 and an air outlet 33, the first air inlet 31 and the interval space are in communication, and the second air inlet 32 and the pressure relief hole 21 are in communication;

[0056] The exhaust air duct 4 is in communication with the air outlet 33.

[0057] In this embodiment, the outer shell 1 serves as the outer layer structure of the oven 100, providing installation support and safety protection for the internal components; the inner cavity 2 is placed inside the outer shell 1 and is a closed space for food baking, and an interval space is formed between the two for installing power supply system, temperature control system and other devices. The side of the inner cavity 2 facing the outer shell 1 is usually provided with heat insulation material to reduce the heat entering the closed space. The inner cavity 2 is specially provided with a pressure relief hole 21 for balancing the pressure inside the inner cavity 2. The fan 3 is the power component of air flow control, which is provided with a first air inlet 31, a second air inlet 32 and an air outlet 33, i.e. the fan 3 is a double air inlet fan 3. Among them, the second air inlet 32 is directly connected with the pressure relief hole 21 of the inner cavity 2, and the first air inlet 31 is in communication with the interval space between the outer shell 1 and the inner cavity 2, and the air outlet 33 is single directed to the exhaust air duct 4. The fan 3 can be arranged at the upper part, side part or bottom part of the oven 100, such as Figure 3In the embodiment shown, the fan 3 is arranged on the top of the oven 100, facilitating the connection of the pressure relief hole 21 on the top of the inner cavity 2. The heat dissipation air duct 20 is an air duct for the circulation of heat dissipation air in the interior of the shell. The heat dissipation air duct 20 usually needs to pass through the main heat generating elements. In some embodiments, for example, there is a spacing space for installing devices between the shell 1 and the inner cavity 2, and this spacing space forms the heat dissipation air duct 20.

[0058] When the oven 100 starts the baking operation, the moisture in the food in the inner cavity 2 is rapidly vaporized after being heated, generating a large amount of steam, causing the internal pressure to gradually rise. At this time, the fan 3 connected to the pressure relief hole 21 of the inner cavity 2 starts to operate, and the second air inlet 32 of the fan 3 forms a negative pressure environment under the power of the fan 3. This negative pressure will actively suck the high-pressure gas accumulated in the inner cavity 2 from the pressure relief hole 21 into the interior of the fan 3, and then the gas enters the exhaust air duct 4 through the air outlet 33 of the fan 3, and is finally directed out of the oven 100. During the entire process, the pressure relief hole 21 serves as the outlet for pressure discharge, the fan 3 provides the driving force for active extraction, and the exhaust air duct 4 serves as the channel for airflow guidance, and the three form a complete linkage mechanism. Instead of relying on the natural pressure difference between the inside and outside, the pressure discharge is completed by the active driving of the fan 3, and the active regulation of the pressure in the inner cavity 2 is achieved.

[0059] The conventional oven 100 only relies on the fixed door gap or the pressure relief hole 21 for exhaust, and the exhaust speed is completely determined by the pressure difference. When encountering a sudden increase in steam, the pressure discharge is often delayed. However, this structure composed of the pressure relief hole 21, the double-air-inlet fan 3, and the exhaust air duct 4 can respond to pressure changes in real time through the power of the fan 3, and even if a large amount of steam is generated in a short period of time, the gas can be quickly extracted and discharged, avoiding excessive pressure in the inner cavity 2. The active extraction of pressure can effectively prevent the oven 100 door from being opened by the high pressure in the inner cavity 2, prevent high-temperature gas and soup from splashing and burning the user, and reduce the impact of pressure on the sealing structure of the cavity, thereby reducing the risk of deformation of the equipment. In addition, stable pressure in the inner cavity 2 can create a balanced cooking environment for food, reduce interference to food expansion, shaping, and moisture distribution caused by pressure fluctuations, and keep food in a stable state during the baking process, thereby greatly improving the quality of the baked product.

[0060] When the oven 100 is running, the components installed in the spacing space will generate redundant heat and the inner cavity will also have some heat escaping into the spacing space, which will affect the performance of the components if not dissipated in time. In the embodiment, the first air inlet 31 of the fan 3 is in communication with the spacing space. When the fan 3 starts to extract the high-pressure gas in the inner cavity 2, the first air inlet 31 will also generate suction to suck the hot air flow in the spacing space into the fan 3. Subsequently, the hot air flow in the spacing space and the high-pressure gas in the inner cavity 2 converge in the fan 3 and are discharged into the exhaust air duct 4 through the air outlet 33. At the same time, the external normal-temperature air will naturally supplement the spacing space through the gap of the outer shell 1 or the specially set air inlet, forming a hot air flow extraction and a continuous circulation of normal-temperature air supplement, thereby achieving efficient heat dissipation of the spacing space.

[0061] In the embodiment, the fan 3 simultaneously undertakes the pressure relief and heat dissipation functions through the double air inlets, without the need for additional heat dissipation fans and independent air ducts, thereby reducing the number of components. The two types of air flows share the exhaust air channel, which also makes the internal layout of the device more compact and reduces the manufacturing cost, thereby providing a possibility for the miniaturized design of the oven 100. For example Figure 1 The oven 100 in the actual oven 100 is an embedded oven 100, which has higher volume requirements. The compact internal layout can ensure the internal baking space of the oven 100 while ensuring the controllable external size of the oven 100.

[0062] Please refer to Figure 5 and Figure 6 In an embodiment of the present application, the fan 3 further includes an impeller assembly 34, the impeller assembly 34 including a first impeller 341 and a second impeller 342, the first impeller 341 and the second impeller 342 being coaxially arranged; the first air inlet 31 and the second air inlet 32 are respectively arranged at the two ends of the axial direction of the fan 3, the first air inlet 31 is opposite to the first impeller 341 to drive the air flow from the first air inlet 31 into the fan 3 through the first impeller 341; the second air inlet 32 is opposite to the second impeller 342 to drive the air flow from the second air inlet 32 into the fan 3 through the second impeller 342; the air outlet 33 is arranged on the radial side of the fan 3 to discharge the air flow out of the fan 3; the impeller assembly 34 is arranged along the axial direction and has a through channel 346 connecting the space where the first impeller 341 is located and the space where the second impeller 342 is located, the wind pressure generated by the first impeller 341 is greater than the wind pressure generated by the second impeller 342, so as to form a pressure difference in the through channel 346, the pressure difference being directed from the first impeller 341 to the second impeller 342. The first impeller 341 and the second impeller 342 are coaxially installed on a transmission shaft, and the transmission shaft is driven by a driving member 35 such as a motor. As shown in the embodiment of Figure 4 the driving member 35 is erected on the upper part of the first air inlet 31 through a support, which can utilize the air flow of the first air inlet 31 to dissipate heat for the driving member 35 without blocking the air inlet of the first air inlet 31.

[0063] The core execution component of the fan 3 is the impeller assembly 34, which includes a first impeller 341 and a second impeller 342 coaxially arranged through the same drive shaft. In the layout of the fan 3, the first air inlet 31 and the second air inlet 32 are respectively located at the two ends of the axial direction of the fan 3, and each is accurately aligned with the corresponding impeller. The first air inlet 31 is opposite to the first impeller 341, and the airflow driven by the first impeller 341 enters the fan 3 from the port; the second air inlet 32 is opposite to the second impeller 342, and the airflow driven by the second impeller 342 is sucked from the port. The exhaust structure of the fan 3 is the radial side outlet 33, which is used for the exhaust of the two types of airflows. In addition, the impeller assembly 34 is provided with a through passage 346 in the axial direction, which communicates the space where the first impeller 341 and the second impeller 342 are located, and because the wind pressure generated by the first impeller 341 is greater than that of the second impeller 342, a pressure difference is formed in the through passage 346 from the first impeller 341 to the second impeller 342.

[0064] The pressure difference in the through passage 346 forms a pressure barrier from the first impeller 341 side to the second impeller 342 side, which directly acts on the airflow suction process of the second air inlet 32. The second impeller 342 is driven by low wind pressure to leak the pressure airflow, and the reverse pressure generated by the pressure difference will inhibit the airflow from entering the fan 3 from the second air inlet 32, thereby reducing the suction force of the second impeller 342 to the pressure relief hole 21. This inhibitory effect is not to block the pressure relief, but to control the flow of the pressure relief airflow entering the fan 3, so as to avoid excessive gas exhaust caused by excessive suction force.

[0065] The first impeller 341 and the second impeller 342 rotate coaxially, and the rotating speed is kept consistent. The first impeller 341 can still efficiently suck the hot airflow in the interval space due to its high wind pressure characteristics, which fully guarantees the heat dissipation effect. At the same time, the pressure difference inhibits the air inlet of the second air inlet 32, which greatly reduces the additional pressure relief flow that may be introduced by the airflow linkage during the operation of the first impeller 341 under the premise that the rotating speeds of the two impellers are the same, thereby achieving a balance between the heat dissipation capacity and the controllable pressure relief flow.

[0066] After the pressure difference inhibits the pressure relief flow, the total amount of high-temperature gas discharged from the inner cavity 2 through the pressure relief hole 21 and the second air inlet 32 is significantly reduced, which avoids the loss of heat of the inner cavity 2 caused by excessive high-temperature airflow. This makes the heat generated by the heating element of the oven 100 more concentrated on the food roasting, reduces the loss of invalid heat caused by pressure relief, reduces the additional power consumption required by the heating element to maintain the temperature of the inner cavity, and directly improves the energy efficiency of the equipment.

[0067] On the basis of ensuring the heat dissipation effect, the differential pressure precisely controls the pressure relief flow, so that the fan 3 does not need to adjust the flow by reducing the speed or additional components, but only relies on the differential pressure of the through channel 346 to realize the dynamic adaptation of heat dissipation and pressure relief, reducing the energy waste in function cooperation. At the same time, the reduced pressure relief flow reduces the proportion of high temperature in the converged airflow, reduces the heat load of the exhaust air duct 4, and further optimizes the overall energy utilization efficiency.

[0068] Since the impeller assembly 34 is not provided with a middle plate, the overall strength is low, so the impeller assembly 34 in the embodiment is mainly suitable for scenes with relatively low speed.

[0069] Please refer to Figure 5 and Figure 6 In some embodiments of the present application, the first impeller 341 includes a plurality of first blades 3411 arranged at intervals in the circumferential direction, and the second impeller 342 includes a plurality of second blades 3421 arranged at intervals in the circumferential direction; the number of first blades 3411 and second blades 3421 is equal, and each first blade 3411 is connected with the corresponding second blade 3421 to form an integrated blade 340, so that the first blade 3411 and the second impeller 342 form an integrated blade 340, and the interval between adjacent integrated blades 340 forms a through channel 346.

[0070] The equal number of first blades 3411 and second blades 3421 and the connection into an integrated blade 340 make the impeller assembly 34 form a whole rigid structure. When rotating coaxially, the integrated blade 340 avoids deformation or vibration of the split blades due to uneven force, ensuring that the speed and running posture of the first blade 3411 and the second blade 3421 are completely synchronized. This structural stability ensures that the high wind pressure output of the first blade 3411 and the low wind pressure output of the second blade 3421 always maintain a stable difference, providing structural support for the pressure difference in the through channel 346 from the first impeller 341 to the second impeller 342, avoiding pressure difference fluctuations caused by blade deformation.

[0071] The interval between adjacent integrated blades 340 directly forms a through channel 346, and the integrated design of the blades makes the length of the through channel 346 completely match the axial size of the impeller, ensuring that the pressure difference can uniformly act on the entire channel, forming a stable pressure gradient and strengthening the suppression effect on the second air inlet 32.

[0072] The integrated blade 340 enables the first impeller 341 and the second impeller 342 to be driven in the same body, and can more accurately and synchronously respond to the driving shaft power compared to split blades. When the fan 3 is running, the actions of the first blade 3411 sucking heat dissipation airflow and the second blade 3421 sucking pressure relief airflow are completely synchronized, avoiding the power transmission delay that may occur in split structures.

[0073] The integrated blade 340 integrates the first impeller 341, the second impeller 342 and the through channel 346 into a single assembly, reduces the assembly steps and the gap between components of the impeller assembly 34, reduces the risk of air leakage at the gap between the blades or the joint of the assembly, and enables the high wind pressure generated by the first blade 3411 to act more concentratedly on the through channel 346, thereby enhancing the suppression effect of the pressure difference. At the same time, the simplified structure enables the air flow to flow more smoothly in the channel, reduces energy loss, and enables the regulation of the pressure difference on the relief flow to be more efficient.

[0074] In some embodiments of the present application, the impeller assembly 34 further comprises a support, and the plurality of integrated blades 340 are connected to the support.

[0075] The support connects the plurality of integrated blades 340 into a complete impeller unit, greatly improving the overall rigidity of the blade group. When the integrated blade 340 rotates at high speed, it will be subjected to a huge centrifugal force, especially at the end of the blade. The support is fixedly connected to each integrated blade 340, forming a multi-point support and overall force structure, dispersing the centrifugal force borne by the single blade to the entire support, avoiding bending or vibration of the blade due to excessive local stress, and ensuring that the blade always maintains the designed geometric shape.

[0076] Generally, as shown in Figure 6 , if the difference between the outer diameter Q1 of the integrated blade 340 and the inner diameter Q2 is less than 40 mm, the support does not need to be provided, and if Q1-Q2≥40 mm, the support needs to be provided.

[0077] Please refer to 7 and Figure 8 , the support comprises a support disc 345, the support disc 345 and the integrated blade 340 are coaxially connected, and the integrated blade 340 extends to the radial outside of the support disc 345; on the radial outside of the support disc 345, the through channel 346 is formed between adjacent integrated blades 340.

[0078] The centrifugal force generated by the high-speed rotation of the integrated blade 340 acts radially outward, and the connection points of the support disc 345 and the blade are concentrated in the blade root area. The support disc 345 directly transmits the centrifugal force borne by the blade root to the shaft center through its rigid structure. This concentrated constraint on the blade root is more accurate and can effectively resist the shear stress of the blade root, avoiding the root fracture of the blade caused by the centrifugal force, especially suitable for the structure of the blade extending outward. The support disc 345 is coaxially arranged with the blade, ensuring that the centrifugal force of all blades is evenly distributed along the circumferential direction of the support disc 345. The disc-shaped structure of the support disc 345 has excellent radial deformation resistance, and can convert the centrifugal force transmitted by each blade into circumferential stress along the circumference of the disc body, rather than concentrating in a local area.

[0079] The form of the through passage 346 radially outside the support disc 345 is determined by the blade spacing and the edge profile of the support disc 345. The support disc 345 ensures uniform spacing between the blades in the circumferential direction through coaxial positioning, so that the through passage 346 maintains a regular cross section radially outside, and the flow rate of the airflow flowing through the passage is stable, and the aerodynamic impact load generated on the blades is uniformly distributed. The design of the support disc 345 with a passage only on the outside reduces the flow interference of the airflow inside the support structure, and the aerodynamic load borne by the blades is more single, and the stress fluctuation is smaller.

[0080] Please refer to 5 and Figure 6 In some embodiments of the present application, the support includes a support ring 344, the support ring 344 and the integral blade 340 are coaxially connected, the integral blade 340 extends from the radially inner side of the support ring 344 to the radially outer side of the support ring 344; on the radially inner side and the radially outer side of the support ring 344, the through passage 346 is formed between adjacent integral blades 340.

[0081] The support ring 344 is coaxially connected with the integral blade 340, so that the stress of the blade in the circumferential direction forms a symmetrical distribution. The centrifugal force generated by the high-speed rotation of the integral blade 340 is uniformly transmitted to the entire support ring 344 through the connection point with the support ring 344, avoiding the local stress concentration that may occur in the non-coaxial connection. At the same time, the blade extends from the radially inner side to the outer side of the support ring 344, and the support ring 344 is just located in the radial middle region of the blade, which can effectively constrain the radial deformation of the blade. Whether it is the inner side of the blade close to the shaft or the outer end, it can obtain stable support through the support ring 344, greatly improving the bending and vibration resistance of the blade.

[0082] The continuous through passage 346 inside and outside the support ring 344 enables the space where the first impeller 341 and the second impeller 342 are located to be fully connected, and the pressure difference can be uniformly transmitted along the passage. Compared with the locally connected passage, this full-area through structure avoids the local attenuation of the pressure difference in the transmission process, so that the pressure difference gradient inside and outside the support ring 344 remains consistent. At the same time, the coaxial support ring 344 ensures that the flow characteristics of all through passages 346 are the same, and the pressure difference in each passage is uniform, and there is no local pressure difference fluctuation due to the difference in passage form, so that the second air inlet 32 can continuously and stably play a restraining role. The flow efficiency of the airflow in the radial inner side and the outer side is consistent, avoiding the energy consumption caused by local vortex. This enables the first blade 3411 to maintain a stable pressure difference without additional power output, and the resistance of the delivery of the cooling airflow and the pressure relief airflow is also greatly reduced, further reducing the overall energy consumption of the fan 3.

[0083] Please refer to Figure 9 In some embodiments of the present application, the cross section of the support ring 344 in the axial direction is an ellipse, and the long axis direction of the cross section is perpendicular to the axial direction.

[0084] The support ring 344 has an elliptical axial cross-section with the long axis perpendicular to the axial direction, so that the support ring 344 forms a wider load bearing surface in the radial direction. The centrifugal force generated by the high-speed rotation of the integral blade 340 mainly acts on the support ring 344 in the radial direction, and the design of the long axis perpendicular to the axial direction allows the support ring 344 to bear the radial load with a larger cross-sectional area, so that the force transmitted by the integral blade 340 is more evenly distributed to the entire ring structure, avoiding deformation of the support ring 344 caused by radial stress concentration. Compared with a circular cross-section, the bending stiffness of an elliptical cross-section in the radial direction is significantly improved, further enhancing the constraint effect on the radial deformation of the integral blade 340.

[0085] The integral blade 340 extends radially inward and outward from the support ring 344, and the connection point thereof mainly bears radial shear force. The long axis direction of the elliptical cross-section is accurately adapted to the stress direction of the integral blade 340, and the cross-sectional thickness and area at the connection point are larger, so that the force generated by the blade can be more stably transmitted, reducing stress concentration at the connection site. At the same time, the streamlined profile of the elliptical cross-section allows the support ring 344 and the integral blade 340 to be connected more smoothly, avoiding local stress peaks caused by right-angle or abrupt structures, and improving the fatigue resistance of the overall structure.

[0086] The elliptical cross-section has a natural streamlined profile, which can significantly reduce the flow resistance of the gas flow in the through channel 346 compared with a square or irregular cross-section. When the gas flow flows along the through channel 346 from the first impeller 341 side to the second impeller 342 side, it will smoothly flow along the elliptical surface of the support ring 344 without obvious gas flow impact or vortex. This streamlined design allows the gas flow to maintain a stable flow rate in the through channel 346 inside and outside the support ring 344, avoiding energy loss caused by sudden changes in cross-section, and providing a more optimal gas flow environment for uniform transmission of pressure difference.

[0087] Please refer to Figure 5 In some embodiments of the present application, the inner diameter and outer diameter of the support ring 344 satisfy: (Q1-Q2) / 10

[0088] When the integrated blade 340 rotates at high speed, a large centrifugal force is generated along the radial direction outward, and the centrifugal force increases with the increase of the blade radius, especially at the end of the blade. The support ring 344 has a radial width greater than 1 / 10 of the radial width of the integrated blade 340, so that the connection points of the integrated blade 340 and the support ring 344 are evenly distributed along the radial direction, rather than concentrated in a small area. The centrifugal force is transmitted to the support ring 344 through multiple dispersed connection points, and the stress borne by each connection point is greatly reduced, effectively avoiding the cracking of the blade root or the connection part caused by excessive local stress.

[0089] In some embodiments of the present application, the inner diameter and the outer diameter of the support ring 344 also satisfy Q3-Q4<(Q1-Q2) / 2. The support ring 344 with a radial width greater than 1 / 2 of the blade will form excessive support. Such support not only cannot significantly improve the overall carrying capacity, but also will increase the inertia load when the impeller assembly 34 rotates due to the increase of the weight of the support ring 344 itself, so that the driving shaft needs to output additional power to overcome the inertia, which indirectly increases the stress burden of the shaft and the blade. Limiting the upper limit of the width can accurately match the demand of the core stress area, and avoid the structural load redundancy caused by invalid support. Moreover, the width of the support ring 344 directly affects the radial size of the through channel 346 between adjacent blades, and if the width is greater than 1 / 2 of the radial width of the integrated blade 340, the radial flow space of the through channel 346 will be greatly compressed.

[0090] Please refer to Figure 10 and Figure 11 In some embodiments of the present application, the axial height of the first impeller 341 is greater than the axial height of the second impeller 342. The axial height of the first impeller 341 is greater, so that the blade can sweep a thicker air layer when rotating, and more air can be pushed into the fan 3 per revolution. In contrast, the axial height of the second impeller 342 is smaller, and the swept air layer is thinner, so the amount of air driven per unit time is naturally less. This difference in driving capacity directly translates into a flow difference, so that the airflow suction amount of the first air inlet 31 is greater than that of the second air inlet 32.

[0091] The axial height difference between the first impeller 341 and the second impeller 342 realizes precise adaptation and synchronous guarantee of the two core needs of heat dissipation and pressure relief. For the continuous and large-capacity heat dissipation demand of the heating element, temperature controller and other devices in the interval space, the larger axial height of the first impeller 341 brings high wind pressure and large flow, which can quickly remove the heat accumulated in the interval space, drive the external normal temperature air to supplement to form an efficient heat dissipation circulation, and avoid performance degradation or damage of the devices due to high temperature. At the same time, for the intermittent and moderate demand of the inner cavity 2 pressure relief, the smaller axial height of the second impeller 342 forms low wind pressure and small flow, which maintains the stability of the cavity in the initial roasting stage through a small amount of exhaust, timely discharges excess gas to avoid pressure exceeding the standard when the steam increases suddenly, and can prevent the moisture in the cavity from flowing out too fast to avoid problems such as food drying and poor expansion. Through the differential design of the axial height, the two realize the consideration of heat dissipation efficiency enhancement and pressure relief balance control.

[0092] Please refer to Figure 11 In some embodiments of the present application, the axial height H1 of the first impeller 341 and the axial height H2 of the second impeller 342 satisfy: H2 / H1≥1 / 10.

[0093] The axial height determines the air flow capture volume and wind pressure output capacity of the impeller. If H2 / H1 is less than 1 / 10, it means that the axial height of the second impeller 342 is too small. Corresponding to the wind pressure level, the negative pressure suction generated by the second impeller 342 will be significantly weak. When the inner cavity 2 of the oven 100 appears steam surge due to food vaporization, the weak suction cannot timely remove the high-pressure gas from the pressure relief hole 21, causing the pressure to continuously accumulate in the cavity, which not only may affect the food roasting quality, but also exists the risk of safety risks such as pressure exceeding the standard and high-temperature gas splashing. In terms of flow, the small axial height makes the air driving amount of the second impeller 342 insufficient per unit time, so even if the negative pressure can be formed, it is difficult to quickly discharge sufficient gas, which also causes the pressure relief response to lag.

[0094] In some embodiments of the present application, the axial height H1 of the first impeller 341 and the axial height H2 of the second impeller 342 satisfy: H2 / H1≤1 / 4. If H2 / H1 is higher than 1 / 10, the axial height of the second impeller 342 is too large, and its air flow capture volume will approach or even partially occupy the performance space of the first impeller 341. This will cause the wind pressure and flow of the second impeller 342 to increase significantly, which may on the one hand divert the power output of the fan 3, making the suction of the first impeller 341 for driving the heat dissipation airflow weaken, unable to quickly remove the heat accumulated in the interval space, causing the risk of device high-temperature aging; on the other hand, the large second impeller 342 will increase the overall load of the fan 3, which may cause the speed to decrease, further weakening the heat dissipation efficiency.

[0095] During the baking process, excessive negative pressure suction will continuously draw away the gas in the inner cavity 2, causing two problems: first, the humidity in the cavity is quickly lost, and the surface of the food material will dry out too early due to insufficient moisture, forming an undesirable state of hard outside and raw inside, affecting the uniformity of cooking; second, the continuous low pressure will damage the expansion and shaping mechanism of the food material, especially for food materials that rely on the pressure in the cavity to support the structure. Control H2 / H1≤1 / 4, control the performance of the second impeller 342 in the range of just enough, so that it can only discharge excess gas exceeding the safety threshold, which can not only avoid the risk of excessive pressure, but also maintain the dynamic balance of humidity and pressure in the cavity, create a suitable baking environment for food materials, and ensure the quality of finished products.

[0096] In general, the above-mentioned limitation on H2 / H1, the lower limit H2 / H1≥1 / 10 ensures that the second impeller 342 has basic pressure relief capability to avoid the risk of pressure accumulation, and the upper limit H2 / H1≤1 / 4 ensures the heat dissipation performance advantage of the first impeller 341, preventing excessive pressure relief and insufficient heat dissipation. The interval not only realizes the precise adaptation of heat dissipation and pressure relief functions, but also balances the stress stability and structural compactness of the impeller assembly 34, ultimately optimizing the energy consumption and service life of the equipment while ensuring the safe operation of the oven 100 and the baking quality.

[0097] For the impeller assembly with a through channel 346, since it is suitable for a slower speed scenario, the outlet angle of the corresponding integrated blade 340 is usually between 30° and 90°.

[0098] Please refer to Figure 4 and Figure 12 In some embodiments of the present application, the oven 100 further comprises a first partition plate 51 and a second partition plate 52 arranged between the outer shell 1 and the inner cavity 2, and the first partition plate 51 is located on the side of the second partition plate 52 close to the outer shell 1; the first partition plate 51 and the second partition plate 52 form a fan cavity 36 and an exhaust air duct 4 therebetween, the side of the fan cavity 36 forms an air outlet 33 and communicates with the exhaust air duct 4 through the air outlet 33; the impeller assembly 34 is arranged in the fan cavity 36, the first impeller 341 faces the first partition plate 51, and the first air inlet 31 is arranged on the first partition plate 51 opposite the first impeller 341; the second impeller 342 faces the second partition plate 52, and the second air inlet 32 is arranged on the second partition plate 52 opposite the second impeller 342.

[0099] The layered arrangement of the first partition plate 51 and the second partition plate 52, the first partition plate 51 close to the outer shell 1, the second partition plate 52 close to the inner cavity 2, the space between the two is divided into the fan cavity 36 and the exhaust air duct 4, forming a double-layer isolation, partitioned flow structure basis, the first impeller 341 faces the first partition plate 51 and directly opposite the first air inlet 31, the second impeller 342 faces the second partition plate 52 and directly opposite the second air inlet 32, so that the heat dissipation airflow and the pressure relief airflow are respectively sucked from the corresponding air inlet, and are completely independent before entering the fan cavity 36. After the heat dissipation airflow enters through the first air inlet 31, it is driven by the first impeller 341 to the fan cavity 36, and then enters the exhaust air duct 4 through the side air outlet 33; after the pressure relief airflow is sucked through the second air inlet 32, it first completes pressure balance in the fan cavity 36, and then is discharged together with the flow path of the exhaust air duct 4.

[0100] The heat dissipation airflow is oriented to enter from the first air inlet 31, and flows through the fan cavity 36 and the exhaust air duct 4 throughout, without backflowing to the inner cavity 2 to affect the baking environment; the pressure relief airflow is independently sucked from the second air inlet 32, and only meets the heat dissipation airflow in the fan cavity 36, avoiding mixing into the heat dissipation airflow to cause heat exchange efficiency to decrease. The path boundaries of the two types of airflow are clear, and the heat dissipation and pressure relief functions do not interfere with each other, and the respective operation efficiency is significantly improved.

[0101] The fan cavity 36, the exhaust air duct 4 and the impeller assembly 34 are integrated between the first partition plate 51 and the second partition plate 52, greatly improving the space utilization, and adapting to the limited installation environment inside the oven 100. At the same time, the airflow path is greatly shortened, the process of the heat dissipation airflow from suction to discharge is more simple, and the pressure relief airflow can be discharged without additional channel, reducing the energy loss in the airflow conveying process, reducing the operation energy consumption of the fan 3, and improving the overall energy efficiency of the equipment.

[0102] Please refer to Figure 12 , Figure 13 and Figure 14 In some embodiments of the present application, a pressure relief channel 53 is arranged between the second air inlet 32 and the pressure relief hole 21, and the cross-sectional size of the pressure relief channel 53 gradually increases from the pressure relief hole 21 to the second air inlet 32.

[0103] The gradually expanding structure of the cross-sectional size of the pressure relief channel 53, that is, similar to a horn-like structure, when the high-pressure gas in the inner cavity 2 enters the channel from the smaller cross-section of the pressure relief hole 21, as the cross-section of the channel gradually increases, the airflow flow space expands, the gas density in unit volume decreases, and the flow rate slows down, and the gas pressure is preliminarily released. This channel form of first collection and then release can make the high-pressure airflow complete stable pressure relief before reaching the second air inlet 32, avoiding the airflow impacting the second impeller 342 at high speed. At the same time, the gradually changing cross-sectional shape reduces the sudden change of the airflow in the channel, greatly reducing the vortex resistance generated by the sudden change of the path, laying the foundation for wind resistance control.

[0104] The second impeller 342 can complete pressure relief without strong negative pressure. If the airflow directly enters the second air inlet 32 at high pressure and high speed, it may cause the load of the impeller to suddenly increase, and even cause airflow turbulence. The gradually increasing cross section allows the airflow to complete pressure buffering in the channel, and the pressure and flow rate when reaching the second air inlet 32 are exactly matched with the driving capacity of the second impeller 342, forming an orderly connection of channel pressure relief and impeller pumping. This smooth connection avoids the violent impact of airflow and impeller blades, reducing vibration noise caused by airflow impact from the source, while reducing airflow resistance when the impeller is rotating.

[0105] The gradually changing cross section allows the airflow to flow more smoothly, avoiding vortex resistance and impact resistance caused by sudden changes in cross section. The energy loss of the airflow passing through the channel is greatly reduced, and the additional load of the fan 3 driving the pressure relief airflow is reduced. Moreover, the smooth airflow reduces the friction noise with the channel wall, and avoids the vibration noise caused by the impact of high-speed airflow on the impeller, significantly reducing the overall noise level of the oven 100 during operation and improving the user experience.

[0106] In some embodiments, the pressure relief hole 21 and the second air inlet 32 each include a plurality of small holes. When the high-pressure gas in the inner cavity 2 reaches the pressure relief hole 21, it is divided into multiple independent small airflows by the plurality of small holes, breaking the concentrated airflow beam formed by a single hole. These dispersed small airflows can more evenly fill the channel space after entering the pressure relief channel 53, avoiding uneven flow rate caused by excessive local airflow density. When the airflow reaches the second air inlet 32, which also has a multi-hole structure, it is again combed and sorted by the small holes, further weakening the concentrated impact force of the airflow, allowing the airflow to enter the fan cavity 36 in a more gentle state. Figure 12 and Figure 13 In the embodiments shown in

[0107] Please refer to Figure 13 and Figure 14 , the pressure relief channel 53 has a horn-like structure with a smaller bottom opening and a larger upper opening. The top of the pressure relief channel 53 is also provided with a connecting buckle 531, and the second partition plate 52 has a connecting hole at the corresponding position. By inserting and rotating the connecting buckle 531, it can be clamped into the connecting hole, achieving the fixation of the pressure relief channel 53.

[0108] For a more intuitive presentation, the following table shows the actual measurement data of the pressure relief and heat dissipation of the impeller assembly 34 in the embodiments of the present application.

[0109] Design Parameters Example 1 Example 2 Example 3 First / Second Impeller Height 13.5mm / 13.5mm 13.5mm / 13.5mm 22.3mm / 4.7mm First Inlet Flow 0.6m 3 / h]] 0.3m 3 / h]] 0.2m 3 / h]] Second Inlet Flow 29.4 m 3 / h]] 33.4 m 3 / h]] 36.3 m 3 / h]] Inlet Flow 30.1 m 3 / h]] 33.7 m 3 / h]] 36.6 m 3 / h]] Energy Efficiency Value 899W 886W 865W

[0110] Among them, the embodiment 1 adopts the impeller assembly 34 shown in Figure 7 , and the embodiment 2 adopts the impeller assembly 34 shown in Figure 5The impeller assembly 34 shown in the embodiment 3 adopts Figure 10 From the above table, it can be seen that in the embodiments of the present application, on the one hand, the heat loss of the inner cavity 2 is very small, the energy is effectively reduced, and the energy saving effect is better; on the other hand, the heat dissipation system can maintain a large air flow, which can quickly and efficiently discharge the heat accumulated in the equipment, and thus achieve a better heat dissipation effect.

[0111] From the above table, it can be seen that in the embodiments of the present application, on the one hand, the heat loss of the inner cavity 2 is very small, the energy is effectively reduced, and the energy saving effect is better; on the other hand, the heat dissipation system can maintain a large air flow, which can quickly and efficiently discharge the heat accumulated in the equipment, and thus achieve a better heat dissipation effect.

[0112] The above is only a preferred embodiment of the present application, and is not used to limit the present application, any modification, equivalent replacement and improvement made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. An oven, characterized in that, The oven includes: The outer casing; a heat dissipation duct is provided inside the outer casing; Inner cavity; the inner cavity is disposed within the outer shell, and the inner cavity is provided with a pressure relief hole; The fan includes a first air inlet, a second air inlet, and an air outlet. The first air inlet is connected to the heat dissipation duct, and the second air inlet is connected to the pressure relief hole. Exhaust duct; the exhaust duct is connected to the air outlet; The fan also includes an impeller assembly, which includes a first impeller and a second impeller, and the first impeller and the second impeller are coaxially arranged. The first air inlet and the second air inlet are respectively located at both ends of the fan's axial direction. The first air inlet is opposite to the first impeller so that airflow is driven by the first impeller to enter the fan from the first air inlet. The second air inlet is opposite to the second impeller so that airflow is driven by the second impeller to enter the fan from the second air inlet. The air outlet is located on the radial side of the fan so that airflow can be discharged from the fan. The impeller assembly is provided with a through channel along the axial direction to connect the space where the first impeller is located and the space where the second impeller is located. The wind pressure generated by the first impeller is greater than the wind pressure generated by the second impeller, so as to form a pressure difference from the first impeller to the second impeller in the through channel.

2. The oven as described in claim 1, characterized in that, The first impeller includes a plurality of first blades spaced apart along the circumferential direction, and the second impeller includes a plurality of second blades spaced apart along the circumferential direction; the number of first blades and second blades are equal, and each first blade is connected to a corresponding second blade to form an integral blade, so that the first blade and the second impeller form an integral blade, and the interval between adjacent integral blades forms the through channel.

3. The oven as described in claim 2, characterized in that, The impeller assembly also includes a support member, to which multiple integral blades are connected.

4. The oven as described in claim 3, characterized in that, The support member includes a support ring, which is coaxially connected to the integral blade. The integral blade extends from the radially inner side of the support ring to the radially outer side of the support ring. Through channels are formed between adjacent integral blades on the radially inner side and the radially outer side of the support ring, respectively. Alternatively, the support member includes a support disk, the support disk and the integral blade are coaxially connected, and the integral blade extends to the radially outer side of the support disk; on the radially outer side of the support disk, the through channel is formed between adjacent integral blades.

5. The oven as described in claim 4, characterized in that, The cross-section of the support ring in the axial direction is elliptical, and the major axis of the cross-section is perpendicular to the axial direction.

6. The oven as described in claim 4 or 5, characterized in that, The inner and outer diameters of the support ring satisfy: (Q1-Q2) / 10 < Q3-Q4, and / or, Q3-Q4 < (Q1-Q2) / 2; where Q1 represents the outer diameter of the integrated blade, Q2 represents the inner diameter of the integrated blade, Q3 represents the outer diameter of the support ring, and Q4 represents the inner diameter of the support ring.

7. The oven as described in claim 4 or 5, characterized in that, The axial height of the first impeller is greater than the axial height of the second impeller.

8. The oven as described in claim 4 or 5, characterized in that, The axial height H1 of the first impeller and the axial height H2 of the second impeller satisfy: 1 / 10 ≤ H2 / H1 ≤ 1 / 4.

9. The oven as described in any one of claims 1 to 8, characterized in that, The oven further includes a first partition and a second partition disposed between the outer shell and the inner cavity, wherein the first partition is located on the side of the second partition closer to the outer shell; A fan cavity and an exhaust duct are formed between the first partition and the second partition. The air outlet is formed on the side of the fan cavity and is connected to the exhaust duct through the air outlet. The impeller assembly is disposed within the fan cavity, with the first impeller facing the first partition and the first air inlet disposed on the first partition at a position opposite to the first impeller; the second impeller faces the second partition and the second air inlet is disposed on the second partition at a position opposite to the second impeller.

10. The oven as described in claim 9, characterized in that, A connecting channel is provided between the second air inlet and the pressure relief hole, and the cross-sectional dimensions of the connecting channel gradually increase from the pressure relief hole to the second air inlet.

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