Air duct assembly and electric heater

Abstract

The utility model provides an air duct assembly and an electric heater, relates to the technical field of household appliances, and solves the technical problem that in the prior art, an air inlet and an air outlet are arranged in the same direction, hot air is absorbed back and heated repeatedly, and the heating efficiency is low. The air duct assembly and the electric heater comprise a cyclone channel, the cyclone channel is provided with an air outlet and at least two sets of air inlet channels, inlet air of the at least two sets of air inlet channels forms rotating airflow in the cyclone channel and then is exhausted from the air outlet, and the directions of the air inlets of the at least two sets of air inlet channels are different from the directions of the air outlets. According to the air duct assembly and the electric heater, the heating efficiency is improved, and the energy consumption is effectively reduced.

Description

Technical Field

[0001] The utility model relates to the technical field of household appliances, in particular to an air duct component and an electric heater. Background Art

[0002] In recent years, with the improvement of people's living standards, most areas in the north have central heating systems, but some areas with cold winters do not have central heating due to various factors such as construction costs and regional restrictions. The low temperature environment in winter in areas without central heating makes life difficult, so single-unit portable electric heaters can greatly meet the needs of areas without central heating. Among them, how to quickly increase the temperature in the room and reduce energy consumption are the primary considerations for customers before purchasing.

[0003] The prior art discloses a heater, including a housing, a fan assembly and an air outlet are arranged in the housing, a horizontally arranged annular converging air duct is arranged in the air outlet, the fan assembly includes a main fan and an auxiliary fan arranged on both sides of the converging air duct, the bottom surface of the converging air duct is provided with an annular air outlet arranged coaxially therewith, and the airflow generated by the fan assembly is gathered and pressurized in the converging air duct and discharged centrally through the air outlet. It is specifically disclosed that the housing is arranged on the roof, and the air inlet and air outlet of the main fan and the auxiliary fan are in the same direction, both facing downward.

[0004] However, when the above-mentioned heater is in use, the air inlet and outlet are both arranged downward, which inevitably leads to the problem of back-absorbed hot air and repeated heating of the hot air, while the cold air outside cannot be heated, seriously affecting the indoor heating efficiency. Utility Model Content

[0005] The purpose of the utility model is to provide an air duct assembly and an electric heater to solve the technical problem that the air inlet and the air outlet are arranged in the same direction in the prior art, hot air is sucked back and heated repeatedly, resulting in low heating efficiency. The preferred technical solution among the many technical solutions provided by the utility model can produce many technical effects as described below.

[0006] In order to achieve the above purpose, the utility model provides the following technical solutions:

[0007] The air duct assembly provided by the utility model comprises a cyclone channel, wherein the cyclone channel is provided with an air outlet and at least two groups of air inlet channels, and the air entering the at least two groups of air inlet channels forms a rotating airflow in the cyclone channel and is discharged from the air outlet, and the direction of the air inlets of the at least two groups of air inlet channels is different from the direction of the air outlet.

[0008] As an optional implementation, the two groups of air inlet channels are arranged along a first direction and the air inlets of the two groups of air inlet channels are oriented in opposite directions, and the air outlets are arranged along a second direction perpendicular to the first direction.

[0009] As an alternative embodiment, the first direction is the horizontal direction, the second direction is the vertical direction, and the air outlet is arranged vertically upward.

[0010] As an alternative embodiment, the size of the air outlet accounts for more than half of the cyclone channel.

[0011] As an alternative embodiment, there are two groups of air inlet channels, the cyclone channel includes two groups of cyclone baffles, the cyclone baffles are arc-shaped baffles, and the two groups of cyclone baffles are arranged centrosymmetrically;

[0012] One of the two groups of air inlet channels can respectively guide the air inlet of one of the two groups of air inlet channels to the other air inlet channel of the two groups of air inlet channels, so that the air inlets of the two groups of air inlet channels form a rotating air flow in the cyclone channel and are discharged from the air outlet.

[0013] As an alternative embodiment, the cyclone baffle includes a first diversion section, an extension section and a second diversion section, and the first diversion section, the extension section and the second diversion section are sequentially connected to form an S-shaped structure;

[0014] The bending radius of the second diversion section is smaller than that of the first diversion section, and the air inlet of one of the two groups of air inlet channels is sequentially guided to the other air inlet channel of the two groups of air inlet channels through the first diversion section, the extension section and the second diversion section.

[0015] As an alternative embodiment, it further includes a baffle plate, the baffle plate is connected to the second diversion section and extends into the cyclone channel, and the setting direction of the baffle plate is the same as the air inlet direction of the air inlet channel.

[0016] As an alternative embodiment, the ratio of the bending radius of the first diversion section to that of the second diversion section is 3:1.

[0017] An electric heater includes the air duct assembly as described above.

[0018] As an alternative embodiment, a fan assembly and a PCT heating assembly are arranged in both groups of air inlet channels, and the two groups of fan assemblies are arranged oppositely.

[0019] The beneficial effects of the present utility model are as follows: The air duct assembly and the electric heater provided by the present utility model include a cyclone passage. The cyclone passage is provided with an air outlet and at least two groups of air inlet passages. The air inlet of at least two groups of air inlet passages can form a rotating air flow in the cyclone passage and then be discharged from the air outlet. The rotating air flow can disrupt the air at the air outlet, accelerate the air flow, and enable the heat to be quickly blended and dissipated, greatly accelerating the increase and maintenance of the indoor temperature and effectively reducing the energy consumption. In addition, the orientation of the air inlets of at least two groups of air inlet passages is different from the orientation of the air outlet, so as to ensure that the air flow discharged from the air outlet will not be repeatedly inhaled by the air inlet passages, avoid the air flow discharged from the air outlet being repeatedly heated, and improve the heating efficiency. Description of the Drawings

[0020] In order to more clearly illustrate the technical solutions in the embodiments of the present utility model or the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, the drawings in the following description are only some embodiments of the present utility model. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0021] Figure 1 is a schematic structural diagram of the electric heater in Embodiment 1 of the present utility model;

[0022] Figure 2 is an exploded view of the electric heater in Embodiment 1 of the present utility model;

[0023] Figure 3 is a schematic structural diagram of the air duct assembly in Embodiment 1 of the present utility model;

[0024] Figure 4 is a schematic structural diagram of the cyclone baffle in Embodiment 1 of the present utility model;

[0025] Figure 5 is a partial schematic structural diagram of the air duct assembly in Embodiment 2 of the present utility model.

[0026] In the figure:

[0027] 100, air duct assembly; 110, fan assembly; 120, PCT heating assembly; 130, cyclone passage; 140, air outlet; 150, air inlet passage; 160, cyclone baffle; 170, first diversion section; 180, extension section; 190, second diversion section; 200, baffle plate; 210, air inlet. Detailed Embodiments

[0028] The following can refer to the drawings Figures 1 to 5And understand the content of the present utility model and the differences between the present utility model and the prior art through the text content. The following further describes in detail the technical solutions (including preferred technical solutions) of the present utility model by way of the accompanying drawings and by listing some optional embodiments of the present utility model. It should be noted that: Any technical feature and any technical solution in this embodiment are one or several of a variety of optional technical features or optional technical solutions. For the sake of concise description, all alternative technical features and alternative technical solutions of the present utility model cannot be exhausted in this document, nor is it convenient to emphasize that each implementation manner of a technical feature is one of the multiple optional implementation manners. Therefore, those skilled in the art should be aware that: Any technical means provided by the present utility model can be replaced, or any two or more technical means or technical features provided by the present utility model can be combined with each other to obtain a new technical solution. Any technical feature and any technical solution within this embodiment do not limit the protection scope of the present utility model. The protection scope of the present utility model should include any alternative technical solution that those skilled in the art can think of without creative work, and any new technical solution obtained by those skilled in the art by combining any two or more technical means or technical features provided by the present utility model with each other.

[0029] In the description of the present invention, it should be noted that unless otherwise specified, the meaning of "a plurality of" is two or more; the orientation or positional relationship indicated by terms such as "upper", "lower", "left", "right", "inner", "outer", "front end", "rear end", "head", "tail", etc. is based on the orientation or positional relationship shown in the accompanying drawings. It is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be construed as a limitation to the present invention. In addition, terms such as "first", "second", "third", etc. are only used for descriptive purposes and cannot be construed as indicating or implying relative importance.

[0030] In the description of the present invention, it should also be noted that unless otherwise clearly defined and limited, the terms "installation", "connection", and "connection" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0031] The present utility model provides an air duct assembly and an electric heater that improve the heating efficiency and effectively reduce energy consumption.

[0032] The following combines Figures 1 to 5 to elaborate more detailedly on the technical solutions provided by the present utility model.

[0033] The present utility model provides an air duct assembly 100, which includes a cyclone passage 130. The cyclone passage 130 is provided with an air outlet 140 and at least two groups of air inlet passages 150. The air inlets of at least two groups of the air inlet passages 150 form a swirling air flow in the cyclone passage 130 and then are discharged from the air outlet 140, and the orientations of the air inlets 210 of at least two groups of the air inlet passages 150 are different from the orientation of the air outlet 140.

[0034] The present utility model provides an air duct assembly 100, which includes a cyclone passage 130. The cyclone passage 130 is provided with an air outlet 140 and at least two groups of air inlet passages 150. The air inlets of at least two groups of the air inlet passages 150 can form a swirling air flow in the cyclone passage 130 and then are discharged from the air outlet 140. The swirling air flow can disrupt the air at the air outlet 140, accelerate the air flow to make the heat blend and dissipate quickly, greatly accelerate the increase and maintenance of the indoor temperature, and effectively reduce the energy consumption. In addition, the orientations of the air inlets 210 of at least two groups of the air inlet passages 150 are different from the orientation of the air outlet 140, so as to ensure that the air flow discharged from the air outlet 140 will not be repeatedly inhaled by the air inlet passages 150, avoid the air flow discharged from the air outlet 140 being repeatedly heated, and improve the heating efficiency.

[0035] It can be understood that the orientations of the air inlets 210 of at least two groups of the air inlet passages 150 are different from the air outlet direction of the air outlet 140, which can avoid the air flow discharged from the air outlet 140 being repeatedly heated and improve the heating efficiency. It should be understood that: the orientations of the air inlets 210 of at least two groups of the air inlet passages 150 are different from the air outlet direction of the air outlet 140. At this time, since the orientations of the air inlets 210 of all the air inlet passages 150 are different from the air outlet direction of the air outlet 140, it can better avoid the air flow discharged from the air outlet 140 being repeatedly heated; or it can be understood that: the orientations of the air inlets 210 of some of the at least two groups of the air inlet passages 150 are different from the air outlet direction of the air outlet 140, which can also improve the heating efficiency.

[0036] In some embodiments of the present utility model, there are two groups of the air inlet passages 150. Two cyclone baffles 160 are arranged in the cyclone passage 130. The cyclone baffles 160 are arc-shaped baffles, and the two cyclone baffles 160 are arranged in central symmetry.

[0037] Each of the two cyclone baffles 160 can guide the air inlet of one of the two groups of the air inlet passages 150 to the other air inlet passage 150 of the two groups of the air inlet passages 150, so that the air inlets of the two groups of the air inlet passages 150 form a swirling air flow in the cyclone passage 130 and are discharged from the air outlet 140.

[0038] In some of the above embodiments of the present utility model, there are two groups of air inlet channels 150, and two groups of cyclone baffles 160 are arranged in the cyclone channel 130. Since both of the two cyclone baffles 160 can deflect the incoming air of one air inlet channel 150 to the other air inlet channel 150, after the incoming air of the two groups of air inlet channels 150 is deflected by the two groups of cyclone baffles 160, a rotating air flow is formed in the cyclone channel 130 and discharged from the air outlet 140. The rotating air flow can disrupt the air at the air outlet 140, accelerate the air flow, and enable the heat to be quickly blended and dissipated, greatly accelerating the increase and maintenance of the indoor temperature and effectively reducing the energy consumption.

[0039] In some embodiments of the present utility model, the cyclone baffle 160 includes a first diversion section 170, an extension section 180, and a second diversion section 190, and the first diversion section 170, the extension section 180, and the second diversion section 190 are sequentially connected to form an S-shaped structure;

[0040] The bending radius of the second diversion section 190 is smaller than that of the first diversion section 170. The incoming air of one of the two groups of air inlet channels 150 is sequentially deflected by the first diversion section 170, the extension section 180, and the second diversion section 190 to the other air inlet channel 150 of the two groups of air inlet channels 150.

[0041] In some of the above embodiments of the present utility model, the cyclone baffle 160 is in an S-shaped structure, and the bending radius of the second diversion section 190 is smaller than that of the first diversion section 170. After the incoming air is deflected by the first diversion section 170 and the extension section 180, its direction is changed by the large bending angle of the second diversion section 190 to form a deflected air flow. The incoming air of the two groups of air inlet channels 150 respectively forms two deflected air flows, and the two deflected air flows are mixed to form a rotating air flow and discharged from the air outlet 140.

[0042] It should be noted here that the bending radius of the second diversion section 190 being smaller than that of the first diversion section 170 means that the bending amplitude of the second diversion section 190 is larger than that of the first diversion section 170. When the incoming air passes through the second diversion section 190, a greater deflection can be achieved. After the air flows passing through the two air inlet channels 150 respectively pass through the two groups of the second diversion sections 190, their directions are both changed to form a rotating air flow.

[0043] It can be understood that when the air inlet channels 150 are arranged in three groups or more groups, a simple deformation of the above cyclone baffle 160 can also be used to change the direction of the air inlet of the air inlet channels 150, so as to form a rotating air flow.

[0044] When the air inlet channels 150 are arranged in three groups or more, the three groups or more air inlet channels 150 can be distributed in a circular array along the circumferential direction of the cyclone channel 130.

[0045] In some embodiments of the present utility model, two groups of the air inlet channels 150 are arranged along a first direction and the air inlet directions of the two groups of the air inlet channels 150 are opposite, and the air outlet 140 is arranged along a second direction perpendicular to the first direction.

[0046] In some of the above embodiments of the present utility model, the two groups of air inlet channels 150 respectively introduce air into the cyclone channel 130 from both sides of the first direction. After a rotating air flow is formed in the cyclone channel 130, it is discharged from the air outlet 140 in the second direction perpendicular to the first direction, thereby ensuring that the air flow discharged from the air outlet 140 will not be repeatedly sucked into the air inlet duct, avoiding the air flow discharged from the air outlet 140 from being repeatedly heated, and improving the heating efficiency.

[0047] In some embodiments of the present utility model, the first direction is the horizontal direction, the second direction is the vertical direction, and the air outlet 140 is arranged vertically upward.

[0048] In some of the above embodiments of the present utility model, the two groups of air inlet channels 150 are arranged along the horizontal direction, the air outlet 140 is arranged vertically upward, and the hot air discharged from the air outlet 140 does not directly blow on people, which can improve the user experience.

[0049] In addition, by using the principle that hot air rises and cold air descends, it can be ensured that the hot air discharged from the air outlet 140 rises, while the cold air entering the air inlet channels 150 is all from below. The electric heater can always preferentially heat the cold air, efficiently generate heat, and reduce energy consumption.

[0050] In some embodiments of the present utility model, the two groups of the air inlet channels 150 are arranged at an oblique angle to each other.

[0051] In some of the above embodiments of the present utility model, the two groups of air inlet channels 150 are arranged along the horizontal direction, and the air inlet directions of the two groups of air inlet channels 150 are opposite. The two groups of air inlet channels 150 are arranged at an oblique angle to each other, so that by introducing air from both sides, a rotating air flow is formed in the cyclone channel 130 under the action of the cyclone baffle 160 and then discharged.

[0052] It can be understood that the two groups of the air inlet channels 150 can also be arranged in parallel and are inclined to both ends of the cyclone channel 130.

[0053] In some embodiments of the present utility model, it further includes a baffle plate 200. The baffle plate 200 is connected to the second diversion section 190 and extends into the cyclone channel 130, and the setting direction of the baffle plate 200 is the same as the air inlet direction of the air inlet channel 150.

[0054] In some of the above embodiments of the present utility model, the setting direction of the baffle 200 is consistent with the air inlet direction of the air inlet passage 150. The baffle 200 can guide the air inlet of the air inlet passage 150 into the cyclone passage 130, avoiding the direct contact between the air inlet at the end of the air inlet passage 150 and the turning air flow on the other side, and affecting the air inlet effect.

[0055] In addition, the baffle 200 can block part of the turning air flow, interrupt part of the turning air flow, thereby disturbing the direction of the turning air flow, prompting the formation of a rotating air flow among the turning air flows, and then mixing with the turning air flow on the other side and discharging from the air outlet 140. The rotating air flow can more quickly disturb the air outside the air outlet 140, accelerate the air flow to make the heat blend and dissipate quickly, greatly accelerating the increase and maintenance of the indoor temperature, and effectively reducing the energy consumption.

[0056] In some embodiments of the present utility model, the ratio of the bending radius of the first guiding section 170 to the bending radius of the second guiding section 190 is 3:1.

[0057] In some of the above embodiments of the present utility model, the bending radius of the second guiding section 190 is much larger than the bending radius of the first guiding section 170. The second guiding section 190 can better change the air flow direction, and is more conducive to the formation of a rotating air flow.

[0058] The present utility model also provides an electric heater, including the air duct assembly 100 as described above.

[0059] In some embodiments of the present utility model, a fan assembly 110 and a PCT heating assembly 120 are provided in each of the two air inlet passages 150, and the two fan assemblies 110 are arranged oppositely.

[0060] For the electric heater provided by the present utility model, a fan assembly 110 and a PCT heating assembly 120 are provided in each of the two air inlet passages 150. The fan assembly 110 and the PCT heating assembly 120 are used to generate hot air. The two fan assemblies 110 are arranged oppositely, and the structure is more compact, which can reduce the occupied space of the electric heater. The hot air enters from at least two air inlet passages 150, and can form a rotating air flow in the cyclone passage 130 and then discharge from the air outlet 140. The rotating hot air flow can disturb the air at the air outlet 140, accelerate the air flow to make the heat blend and dissipate quickly, greatly accelerating the increase and maintenance of the indoor temperature, and effectively reducing the energy consumption. In addition, the air inlet directions of at least two air inlet passages 150 are different from the air outlet direction of the air outlet 140, so as to ensure that the air flow discharged from the air outlet 140 will not be repeatedly inhaled by the air inlet duct, avoiding the repeated heating of the air flow discharged from the air outlet 140 and improving the heating efficiency.

[0061] Embodiment 1:

[0062] The utility model provides an electric heater, as Figures 1 - 4 shown, which includes an air duct assembly 100, a fan assembly 110 and a PCT heating assembly 120. The air duct assembly 100 includes a cyclone channel 130. The cyclone channel 130 is provided with an air outlet 140 and two groups of air inlet channels 150. A fan assembly 110 and a PCT heating assembly 120 are provided in both groups of air inlet channels 150. The fan assembly 110 and the PCT heating assembly 120 are used to convey hot air into the cyclone channel 130, and the hot air forms a rotating air flow in the cyclone channel 130 and then is discharged from the air outlet 140.

[0063] Furthermore, the cyclone channel 130 includes two groups of cyclone baffles 160. The cyclone baffles 160 are arc-shaped baffles, and the two groups of cyclone baffles 160 are arranged in central symmetry to form the cyclone channel 130. The two groups of air inlet channels 150 are arranged at both ends of the two groups of cyclone baffles 160.

[0064] Specifically, the two groups of air inlet channels 150 are arranged diagonally, and the two groups of air inlet channels 150 are arranged parallel to each other in the horizontal direction. The air outlet 140 is arranged in the vertical direction, and the air outlet 140 is arranged vertically upward. The fans of the two groups of fan assemblies 110 are arranged in the two groups of air inlet channels 150, and the two groups of fans are arranged oppositely.

[0065] Furthermore, the cyclone baffle 160 includes a first diversion section 170, an extension section 180 and a second diversion section 190. The first diversion section 170, the extension section 180 and the second diversion section 190 are connected in sequence to form an S-shaped structure;

[0066] The bending radius of the second diversion section 190 is smaller than that of the first diversion section 170. The air inlet of one of the two groups of air inlet channels 150 is diverted through the first diversion section 170, the extension section 180 and the second diversion section 190 to the other air inlet channel of the two groups of air inlet channels 150.

[0067] The two groups of cyclone baffles 160 can respectively divert the air inlet of one of the two groups of air inlet channels 150 to the other air inlet channel of the two groups of air inlet channels 150, so that the air inlets of the two groups of air inlet channels 150 form a rotating air flow in the cyclone channel 130 and are discharged from the air outlet 140.

[0068] Furthermore, it further includes a baffle plate 200. The baffle plate 200 is connected to the second diversion section 190 and extends into the cyclone channel 130, and the setting direction of the baffle plate 200 is consistent with the air inlet direction of the air inlet channel 150.

[0069] The air supply process of the electric heater provided by the present utility model is as follows: The electric heater is placed on the ground. Under the action of the fan assembly 110, air enters from the air inlet channel 150 and hot air is generated under the heating action of the PCT heating assembly 120. The hot air enters the cyclone channel 130 and blows upward. Blowing upward can avoid direct blowing on people and improve the user experience. Secondly, blowing the hot air upward can reasonably utilize the principle that hot air rises and cold air sinks, ensuring that the air inlet channel 150 can effectively introduce cold air, avoiding repeated circulation and heating of hot air, enabling the indoor temperature to rise rapidly and reducing energy consumption.

[0070] Example 2:

[0071] The difference between this Example 2 and Example 1 is that as Figure 5 shown, the two groups of the air inlet channels 150 can also be arranged in parallel and are inclined at both ends of the cyclone channel 130.

[0072] In the description of this specification, the description with reference to terms such as "example", "embodiment" or "some embodiments" means that the specific features, structures, materials or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in a suitable manner in any one or more embodiments or examples.

[0073] Certainly, the present invention is not limited to the above embodiments. Those skilled in the art can also make equivalent deformations or substitutions without departing from the spirit of the present invention, and these equivalent deformations or substitutions are all included in the scope defined by the claims of this application.

Claims

1. An air duct assembly, characterized in that: It includes a cyclone channel, which is provided with an air outlet and at least two groups of air inlet channels. The air in the at least two groups of air inlet channels forms a rotating airflow in the cyclone channel and is discharged from the air outlet, and the direction of the air inlets of the at least two groups of air inlet channels is different from that of the air outlet.

2. The air duct assembly according to claim 1, characterized in that: The two groups of air inlet channels are arranged along a first direction and the air inlets of the two groups of air inlet channels are in opposite directions, and the air outlets are arranged along a second direction perpendicular to the first direction.

3. The air duct assembly according to claim 2, characterized in that: The first direction is a horizontal direction, the second direction is a vertical direction, and the air outlet is arranged vertically upward.

4. The air duct assembly according to claim 2, characterized in that: The size of the air outlet accounts for more than half of the proportion of the cyclone channel.

5. The air duct assembly according to any one of claims 1 to 4, characterized in that: The air inlet channel is provided with two groups, and the cyclone channel includes two groups of cyclone baffles, the cyclone baffles are arc-shaped baffles, and the two groups of cyclone baffles are centrally symmetrically arranged; The two groups of cyclone baffles can respectively guide the air inlet from one of the two groups of air inlet channels to the other of the two groups of air inlet channels, so that the air inlet from the two groups of air inlet channels forms a rotating airflow in the cyclone channel and is discharged from the air outlet.

6. The air duct assembly according to claim 5, characterized in that: The cyclone baffle comprises a first guide section, an extension section and a second guide section, wherein the first guide section, the extension section and the second guide section are sequentially connected to form an S-shaped structure; The bending radius of the second guide section is smaller than the bending radius of the first guide section, and the air in one of the two groups of air inlet channels is guided to the other air inlet channel of the two groups of air inlet channels via the first guide section, the extension section and the second guide section in sequence.

7. The air duct assembly according to claim 6, characterized in that: It also includes a spoiler, which is connected to the second guide section and extends into the cyclone channel, and the setting direction of the spoiler is consistent with the air inlet direction of the air inlet channel.

8. The air duct assembly according to claim 6, characterized in that: The ratio of the bending radius of the first guide section to that of the second guide section is 3:

1.

9. An electric heater, characterized in that: It comprises an air duct assembly as described in any one of claims 1 to 8.

10. The electric heater according to claim 9, characterized in that: A fan assembly and a PCT heating assembly are arranged in both groups of the air inlet passages, and the two groups of the fan assemblies are arranged opposite to each other.

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