Air conditioning unit

Abstract

The invention discloses an air conditioning unit which comprises an air outlet structure, a first air inlet structure and a second air outlet structure. The centrifugal fan communicates with the air outlet structure, and an air opening of the centrifugal fan discharges air towards the first air outlet cavity; an included angle is formed between the air outlet direction of the centrifugal fan and the airflow circulation direction of the first air outlet cavity, and a fan air opening of the centrifugal fan downwards and obliquely blows air to the first air outlet cavity; and the electric heater is arranged in the first air outlet cavity. The air conditioning unit effectively solves the problems that in the prior art, an electric heater of an air conditioning unit is poor in heating effect and too high in surface temperature.

Description

Technical Field

[0001] The present invention relates to the field of refrigeration technology, and in particular to an air conditioning unit. Background Art

[0002] As people demand more energy efficiency of air conditioners and pay more attention to the problem of global warming, more and more air conditioners are beginning to use flammable refrigerants. When a flammable refrigerant unit is used with an electric heater, the surface temperature of the auxiliary electric heater must be lower than the maximum allowable surface temperature due to the flammable characteristics of the flammable refrigerant.

[0003] At present, most air conditioners using centrifugal fans have small air outlets, so part of the air volume of the fan is not used, which is not conducive to reducing the surface temperature of the electric heating wire. In addition, some air conditioners are installed with air ducts when in use. In order to ensure the sealing effect between the air duct and the unit, materials are usually used for filling. In addition, the rear air outlet of conventional electric heating equipment is straight-out, and the temperature at the connection of the air duct is relatively high. This part of the filling material has a risk of combustion at high temperatures.

[0004] See also Figure 1 to Figure 2 In the prior art, the centrifugal fan 101 of the air conditioning unit is generally placed horizontally, the fan cavity 102 is connected to the centrifugal fan 101, the upper and lower side plates are horizontal, the electric heater 103 is located in the fan cavity 102, and the electric heater 103 is placed horizontally.

[0005] In this case, due to the centrifugal fan outlet velocity distribution characteristics, the high-speed airflow away from the fan center flows along the fan cavity to the unit outlet, and the high-speed airflow does not flow through the electric heating wire, and does not play a beneficial effect. Because the electric heater is placed horizontally, the number of electric heating wires in contact with the airflow direction is small. When the airflow flows through the electric heater, the electric heating wire at the rear relative to the airflow direction has a poor convective heat transfer effect because the airflow is blocked by the upstream electric heating wire, and the surface temperature of the electric heating wire at the rear is higher. Figure 2 and Figure 3 In the above case, a high-temperature eddy current package 104 will be formed behind the electric heating wire, and heat will gather at the high-temperature eddy current package 104, which will further increase the surface temperature of the downstream electric heating wire.

[0006] In summary, the electric heater of the air-conditioning unit in the prior art has poor heating effect and too high surface temperature. Summary of the invention

[0007] An embodiment of the present invention provides an air conditioning unit to solve the problems of poor heating effect and excessively high surface temperature of an electric heater of an air conditioning unit in the prior art.

[0008] To achieve the above-mentioned objectives, the present invention provides an air-conditioning unit, comprising: an air outlet structure, the air outlet structure having a first air outlet cavity; a centrifugal fan, the centrifugal fan being connected to the air outlet structure, the fan outlet of the centrifugal fan discharging air toward the first air outlet cavity; an angle being formed between the air outlet direction of the centrifugal fan and the air flow direction of the first air outlet cavity, the fan outlet of the centrifugal fan being tilted downward to blow toward the first air outlet cavity; and an electric heater being arranged in the first air outlet cavity.

[0009] Furthermore, the air outlet structure further comprises a second air outlet cavity, and the fan air outlet of the centrifugal fan is connected with the first air outlet cavity through the second air outlet cavity;

[0010] The second air outlet cavity has a first end face and a second end face, the first end face is connected to the fan outlet of the centrifugal fan, and the first end face is parallel to the air outlet section of the fan outlet; the second end face is connected to the first air outlet cavity, and the second end face is perpendicular to the air flow direction of the first air outlet cavity.

[0011] Furthermore, the bottom wall and the side wall of the second air outlet cavity form a sinking area, and the sinking area is located below the first end surface.

[0012] Furthermore, the angle ranges from 8° to 12°.

[0013] Further, the extension direction of the first air outlet cavity is arranged along the horizontal direction, and the airflow direction of the first air outlet cavity is the horizontal direction.

[0014] Furthermore, the air conditioning unit further comprises an external air duct, the external air duct being in communication with the first air outlet cavity, and the airflow passes through the first air outlet cavity and enters the external air duct;

[0015] A step structure is formed at a connection between the first air outlet cavity and the external air duct, and an inner diameter of the first air outlet cavity at the connection is greater than an inner diameter of the external air duct at the connection.

[0016] Furthermore, the electric heater comprises a plurality of groups of electric heating wires, and the plurality of groups of electric heating wires are arranged at intervals and distributed along the air flow direction.

[0017] Furthermore, the electric heater comprises a metal plate, the metal plate is fixed on the inner wall of the first air outlet cavity, and the electric heating wire is fixedly connected to the metal plate;

[0018] The electric heater further comprises a fuse and a temperature limiter, and the fuse and the temperature limiter are arranged on the metal plate.

[0019] Furthermore, the angle is 10°, and the electric heater is arranged at a position directly opposite to the fan outlet of the centrifugal fan.

[0020] Furthermore, the air-conditioning unit is a rooftop air conditioner.

[0021] The air conditioning unit of the present invention places the centrifugal fan at an angle, so that the fan outlet of the centrifugal fan is tilted downward to blow toward the first air outlet cavity. Due to the centrifugal fan outlet speed distribution characteristics, the high-speed airflow away from the center of the fan is controlled by the tilted fan outlet to tilt downward, so that the high-speed airflow can flow to the electric heater, making full use of the high-speed airflow, enhancing the heat dissipation effect of the airflow of the electric heater, so that the electric heater downstream of the airflow can also effectively dissipate heat without the problem of over-temperature. And as the heat dissipation effect is improved, the heating effect of the electric heater is effectively improved. Under the same heating effect, an electric heater with smaller power can be selected to achieve energy saving and environmental protection. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 It is a structural schematic diagram of an air conditioning unit in the prior art;

[0023] Figure 2 It is a schematic diagram of air flow of an air conditioning unit in the prior art;

[0024] Figure 3 It is an air flow simulation diagram of an air conditioning unit in the prior art;

[0025] Figure 4 is a structural schematic diagram of an air conditioning unit according to an embodiment of the present invention;

[0026] Figure 5 is a schematic diagram of air flow of an air conditioning unit according to an embodiment of the present invention;

[0027] Figure 6 is an air flow simulation diagram of an air conditioning unit according to an embodiment of the present invention;

[0028] Figure 7 is a structural schematic diagram of an external air duct and a first air outlet cavity of an air conditioning unit according to an embodiment of the present invention;

[0029] Figure 8 is a schematic diagram of the external structure of an air conditioning unit according to an embodiment of the present invention;

[0030] Fig. 9 Schematic diagram of the coordination of the air outlet structure and the centrifugal fan of an air conditioning unit according to an embodiment of the present invention;

[0031] Fig.10 is a front view of an electric heater of an air conditioning unit according to an embodiment of the present invention;

[0032] Fig.11 is a side view of an electric heater of an air conditioning unit according to an embodiment of the present invention;

[0033] Fig.12 4 is a bottom view of the electric heater of the air conditioning unit according to the embodiment of the present invention. DETAILED DESCRIPTION

[0034] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments, but they are not intended to limit the present invention.

[0035] See also Figures 4 to 12 As shown, according to an embodiment of the present invention, an air-conditioning unit is provided, the air-conditioning unit includes an air outlet structure 10, a centrifugal fan 20 and an electric heater 30, the air outlet structure 10 has a first air outlet cavity 11; the centrifugal fan 20 is connected to the air outlet structure 10, and the fan outlet 21 of the centrifugal fan 20 discharges air toward the first air outlet cavity 11; there is an angle between the air outlet direction of the centrifugal fan 20 and the air flow direction of the first air outlet cavity 11, and the fan outlet 21 of the centrifugal fan 20 is tilted downward to blow toward the first air outlet cavity 11; the electric heater 30 is arranged in the first air outlet cavity 11.

[0036] The air conditioning unit of the present invention places the centrifugal fan at an angle, so that the fan outlet 21 of the centrifugal fan 20 is tilted downward to blow toward the first air outlet cavity 11. Due to the centrifugal fan outlet speed distribution characteristics, the high-speed airflow away from the center of the fan is controlled by the tilted fan outlet 21 to tilt downward, so that the high-speed airflow can flow to the electric heater, making full use of the high-speed airflow, enhancing the heat dissipation effect of the airflow of the electric heater, so that the electric heater downstream of the airflow can also effectively dissipate heat without the problem of overtemperature. And as the heat dissipation effect is improved, the heating effect of the electric heater is effectively improved. Under the same heating effect, an electric heater with lower power can be selected to achieve energy saving and environmental protection.

[0037] Preferably, the air outlet structure 10 further has a second air outlet cavity 12, and the fan air outlet 21 of the centrifugal fan 20 is connected to the first air outlet cavity 11 through the second air outlet cavity 12;

[0038] The second air outlet cavity 12 has a first end face 12a and a second end face 12b, the first end face 12a is connected to the fan outlet 21 of the centrifugal fan 20, and the first end face 12a is parallel to the air outlet cross-section of the fan outlet 21; the second end face 12b is connected to the first air outlet cavity 11, and the second end face 12b is perpendicular to the air flow direction of the first air outlet cavity 11.

[0039] The second air outlet cavity plays the role of guiding and transitioning, so that the airflow blown out by the centrifugal fan is guided and rectified through the second air outlet cavity after passing through the fan air outlet, and then enters the first air outlet cavity, thereby increasing the area of ​​the high-efficiency convection region of the air outlet, which is beneficial to the heat dissipation of the electric heater.

[0040] Combination Figure 4and Figure 5 As shown, the bottom wall and the side wall of the second air outlet cavity 12 form a sinking area 12c, and the sinking area 12c is located below the first end surface 12a.

[0041] The sinking area 12c forms an airflow gradient. After the airflow flows out of the fan outlet 21, due to the gravity and the wall adhesion, the airflow direction sags, which can increase the area of ​​the high-efficiency convection area of ​​the air outlet, which is beneficial to the convection heat dissipation effect of the electric heating wire.

[0042] Preferably, the angle ∠α is in the range of 8° to 12°, wherein the minimum angle is 8°. If the angle is too small, the flow directions are close to each other, which is not conducive to the convection heat dissipation of the electric heater. The maximum angle is 12°. If the angle is too large, the flow rate will be lost, which will reduce the heating effect. Therefore, the angle is kept between 8° and 12° for the best effect.

[0043] In this embodiment, the extension direction of the first air outlet cavity 11 is arranged in the horizontal direction, and the airflow direction of the first air outlet cavity 11 is the horizontal direction.

[0044] Because the centrifugal fan is placed at an angle, there will be an angle between its air outlet direction and the horizontal direction of the electric heater. The electric heating wire close to the fan outlet will not block the air flow through the subsequent electric heating wire, which can reduce the surface temperature of the electric heating wire away from the fan outlet. At the same time, the tilted placement can eliminate the high-temperature eddy current package behind the heating wire, further reducing the surface temperature of the electric heating wire. Figure 6 .

[0045] See also Figure 7 The air conditioning unit further includes an external air duct 40, the external air duct 40 is connected to the first air outlet cavity 11, and the airflow passes through the first air outlet cavity 11 and enters the external air duct 40;

[0046] A step structure 41 is formed at a connection between the first air outlet cavity 11 and the external air duct 40 , and an inner diameter of the first air outlet cavity 11 at the connection is greater than an inner diameter of the external air duct 40 at the connection.

[0047] The air from the fan enters the external air duct 40 through the air outlet structure. Since the air passes through the electric heater, the air outlet temperature is relatively high. At this time, if it passes directly through the contact surface between the unit air outlet and the air duct, it is easy to cause the filler between the contact surfaces to be ignited. Therefore, the present invention adds a step structure 41 and a structural match. Since the inner diameter of the first air outlet cavity 11 at the connection is larger than the inner diameter of the external air duct 40 at the connection, the step structure 41 forms a safety shrinkage. After the airflow passes through the safety shrinkage, the airflow can be separated from the wall surface, and two secondary flow areas are formed before the safety shrinkage and the external air duct part behind it. There is no airflow attached to the wall in these two secondary flow areas, and the temperature is relatively low. There is not much heat transferred to the air duct connection area through the sheet metal. This method can reduce the temperature of the connection and prevent the filler at the connection from being ignited. The shrinkage length of the step structure is 4%-6% of the air outlet size, and is set according to the specific product needs.

[0048] Combination Figures 10 to 12 As shown, the electric heater 30 includes a plurality of groups of electric heating wires 31 , and the plurality of groups of electric heating wires 31 are arranged at intervals along the air flow direction.

[0049] Multiple groups of electric heating wires are distributed at intervals along the direction of air flow, which can ensure the heating effect without affecting the flow rate of the air flow and without losing the air volume. The electric heating wires are connected end to end to form a whole, and the electric heating wires are a spirally wound string structure. The electric heater can be composed of 4 groups of electric heating wires, and the 4 groups of electric heating wires are arranged in a horizontal direction.

[0050] Preferably, the electric heater 30 comprises a metal plate, the metal plate is fixed on the inner wall of the first air outlet cavity 11, and the electric heating wire 31 is fixedly connected to the metal plate;

[0051] The electric heater 30 further includes a fuse 32 and a temperature limiter 33 , and the fuse 32 and the temperature limiter 33 are disposed on the metal plate.

[0052] The metal plate provides installation reliability, and the fuse and temperature limiter mainly provide high temperature protection for the electric heater.

[0053] In this embodiment, the angle is 10°, and the electric heater 30 is disposed at a position directly opposite to the fan outlet 21 of the centrifugal fan 20 .

[0054] The setting of the angle and the electric heater can make the high-speed airflow away from the center of the fan flow to the electric heater, so as to make full use of the high-speed airflow and enhance the airflow heat dissipation effect of the electric heater.

[0055] See also Figure 8 and Fig. 9The air conditioning unit is a rooftop air conditioner. The upper part of the rooftop air conditioner is the external unit side, and the lower part of the rooftop air conditioner is the internal unit side. The centrifugal fan 20 and the air outlet structure 10 are located on the air outlet side (left side) of the internal unit side of the unit. The airflow enters through the return air side (right side), enters the air outlet side through the intermediate evaporator, enters the air outlet structure through the centrifugal fan, and then enters the external air duct for blowing out.

[0056] The structural coordination of the air outlet structure, the centrifugal fan and the electric heater is very suitable for use in rooftop air conditioners and can effectively improve the heating effect of the rooftop air conditioners.

[0057] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present application. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "comprise" and / or "include" are used in this specification, it indicates the presence of features, steps, operations, devices, components and / or combinations thereof.

[0058] It should be noted that the terms "first", "second", etc. in the specification and claims of the present application and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the numbers used in this way can be interchanged where appropriate, so that the embodiments of the present application described herein can be implemented in an order other than those illustrated or described herein.

[0059] Of course, the above are preferred embodiments of the present invention. It should be noted that, for those skilled in the art, several improvements and modifications can be made without departing from the basic principles of the present invention, and these improvements and modifications are also considered to be within the protection scope of the present invention.

Claims

1. An air conditioning unit, characterized in that: include: An air outlet structure (10), wherein the air outlet structure (10) has a first air outlet cavity (11); a centrifugal fan (20), the centrifugal fan (20) being in communication with the air outlet structure (10), the fan air outlet (21) of the centrifugal fan (20) discharging air towards the first air outlet cavity (11); an angle being formed between the air outlet direction of the centrifugal fan (20) and the air flow direction of the first air outlet cavity (11), the fan air outlet (21) of the centrifugal fan (20) being tilted downward to blow towards the first air outlet cavity (11); An electric heater (30) is arranged in the first air outlet cavity (11).

2. The air conditioning unit according to claim 1, characterized in that: The air outlet structure (10) further comprises a second air outlet cavity (12), and the fan air outlet (21) of the centrifugal fan (20) is connected to the first air outlet cavity (11) through the second air outlet cavity (12); The second air outlet cavity (12) comprises a first end face (12a) and a second end face (12b); the first end face (12a) is connected to a fan air outlet (21) of the centrifugal fan (20); the first end face (12a) is parallel to the air outlet cross section of the fan air outlet (21); the second end face (12b) is connected to the first air outlet cavity (11); the second end face (12b) is perpendicular to the air flow direction of the first air outlet cavity (11).

3. The air conditioning unit according to claim 2, characterized in that: The bottom wall and the side wall of the second air outlet cavity (12) form a sinking area (12c), and the sinking area (12c) is located below the first end surface (12a).

4. The air conditioning unit according to claim 1, characterized in that: The angle ranges from 8° to 12°.

5. The air conditioning unit according to claim 4, characterized in that: The extension direction of the first air outlet cavity (11) is arranged in the horizontal direction, and the airflow direction of the first air outlet cavity (11) is in the horizontal direction.

6. The air conditioning unit according to claim 1, characterized in that: The air conditioning unit further comprises an external air duct (40), wherein the external air duct (40) is in communication with the first air outlet cavity (11), and air flows through the first air outlet cavity (11) into the external air duct (40); A step structure (41) is formed at the connection between the first air outlet cavity (11) and the external air duct (40), and the inner diameter of the first air outlet cavity (11) at the connection is larger than the inner diameter of the external air duct (40) at the connection.

7. The air conditioning unit according to claim 1, characterized in that: The electric heater (30) comprises a plurality of groups of electric heating wires (31), and the plurality of groups of electric heating wires (31) are arranged in a spaced manner along the air flow direction.

8. The air conditioning unit according to claim 7, characterized in that: The electric heater (30) comprises a metal plate, the metal plate is fixed on the inner wall of the first air outlet cavity (11), and the electric heating wire (31) is fixedly connected to the metal plate; The electric heater (30) further comprises a fuse (32) and a temperature limiter (33), wherein the fuse (32) and the temperature limiter (33) are arranged on the metal plate.

9. The air conditioning unit according to claim 1, characterized in that: The angle is 10°, and the electric heater (30) is arranged at a position directly opposite to the fan outlet (21) of the centrifugal fan (20).

10. The air conditioning unit according to claim 1, characterized in that: The air conditioning unit is a rooftop air conditioner.

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