Heat pump dryers and their auxiliary heating devices
By using a heating film with a carbon nanotube or rare earth nanotube heating layer as an auxiliary heating device in a heat pump dryer, the problem of refrigerant leakage, combustion, or explosion caused by traditional resistance wires is solved, thus improving safety and energy efficiency.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- QINGDAO HAIER SMART TECH R & D CO LTD
- Filing Date
- 2025-05-20
- Publication Date
- 2026-05-26
AI Technical Summary
When using R290 refrigerant, existing heat pump dryers may pose a safety hazard of refrigerant leakage leading to combustion or explosion if a traditional resistance wire auxiliary heating device is added.
A heating film with a carbon nanotube or rare earth nanotube heating layer is used as an auxiliary heating device. Heat is conducted through infrared radiation to avoid the refrigerant from burning due to high temperature resistance wire. The operating temperature is far below the deflagration threshold of R290 refrigerant.
It improves safety performance, reduces equipment energy consumption, avoids combustion or explosion accidents, and ensures safe use.
Smart Images
Figure CN224280838U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the technical field of clothing processing equipment, specifically providing a heat pump dryer and its auxiliary heating device. Background Technology
[0002] A heat pump dryer is an appliance used to accelerate the drying process of clothes. It mainly consists of a heat pump system, a drum, a drying duct, and a fan. The heat pump system includes a compressor, an evaporator, a condenser, and a throttling device. The specific drying process of a heat pump dryer is as follows: Under the action of the fan, air flows within the drying duct and is heated into dry, hot air by the condenser, then delivered into the drum. The dry, hot air comes into contact with the wet clothes inside the drum, causing the moisture in the clothes to evaporate into water vapor, thus forming humid, hot air. The humid, hot air enters the drying duct from the drum and flows through the evaporator, where the water vapor is condensed into liquid water, thus forming dry, cold air. The dry, cold air flows back through the condenser for the next cycle until the clothes are completely dry.
[0003] Heat pump systems use refrigerants, both fluorinated and non-fluorinated. Because fluorinated refrigerants damage the ozone layer, they are gradually being replaced by environmentally friendly non-fluorinated refrigerants. Among them, R290 (propane) refrigerant, as a new type of environmentally friendly refrigerant, has advantages such as high thermal conductivity and large latent heat of vaporization, significantly improving energy efficiency. However, R290 refrigerant has a safety rating of A3, and under certain conditions (such as when the concentration of R290 in the air reaches 2.1%–9.5% and the ambient temperature ≥470℃), it has a high risk of flammability and explosion. This characteristic necessitates strict safety measures in its application scenarios.
[0004] To improve drying efficiency, existing heat pump dryers typically incorporate auxiliary heating devices within the drying duct. Traditional auxiliary heating devices often use resistance wires as the heat source, but these devices suffer from problems such as excessively high operating temperatures and uneven heating, with localized areas easily exceeding the critical value of 470℃. If the heat pump system uses R290 refrigerant, a refrigerant leak could cause the high-temperature resistance wires to ignite the refrigerant, leading to combustion or explosion, posing a serious safety hazard. Utility Model Content
[0005] The present invention aims to solve the above-mentioned technical problems, namely, to solve the problem that existing heat pump dryers using flammable and environmentally friendly refrigerants as refrigerants may cause combustion or explosion accidents due to refrigerant leakage after the addition of auxiliary heating devices.
[0006] In a first aspect, this utility model provides an auxiliary heating device for a heat pump dryer, the auxiliary heating device comprising a heating film and a heat diffusion component, the heating film being attached to the heat diffusion component to conduct heat to the heat diffusion component.
[0007] The heating film includes a heating layer, which is a carbon nanotube heating layer and / or a rare earth nanotube heating layer.
[0008] In some feasible embodiments of the auxiliary heating device of the heat pump dryer described above, the heating film further includes a first protective layer and a second protective layer, with the heating layer sandwiched between the first protective layer and the second protective layer.
[0009] In some feasible embodiments of the auxiliary heating device of the heat pump dryer described above, there are two heat diffusion components, which are respectively attached to both sides of the heating film.
[0010] In some feasible embodiments of the auxiliary heating device of the heat pump dryer described above, the heat diffusion component includes a substrate and a fin structure, wherein the fin structure is disposed on the side of the substrate away from the heating film.
[0011] In some feasible embodiments of the auxiliary heating device of the heat pump dryer described above, the auxiliary heating device further includes a housing, the housing having an auxiliary air duct inside, and the heat diffusion component being disposed within the auxiliary air duct.
[0012] In some feasible embodiments of the auxiliary heating device of the heat pump dryer described above, the auxiliary air duct has a first air inlet and a first air outlet, and the housing includes a direct current section and a first bend section that are interconnected, the first air inlet being formed on the direct current section and the first air outlet being formed on the first bend section.
[0013] In some feasible embodiments of the auxiliary heating device of the heat pump dryer described above, the heat diffusion component and the heating film are disposed at the first air inlet, and the dimensions of both are adapted to the cross-sectional shape of the first air inlet.
[0014] The auxiliary heating device for the heat pump dryer provided by this utility model, by setting a heating film containing a carbon nanotube heating layer and / or a rare earth nanotube heating layer, can conduct heat to the heat diffusion component by infrared radiation. In this way, when the heating layer is working, the working temperature is much lower than the 470°C deflagration threshold of R290 refrigerant. Compared with traditional resistance wire, it has higher safety performance, thereby avoiding combustion or explosion accidents in the event of refrigerant leakage in the heat pump dryer.
[0015] In a second aspect, the present invention also provides a heat pump dryer, the heat pump dryer including the auxiliary heating device of the heat pump dryer described in any of the above technical solutions, the heat pump dryer further including a drying air duct, and the auxiliary heating device being disposed in the drying air duct.
[0016] In some feasible embodiments of the heat pump dryer described above, the drying duct has a second air outlet, and the drying duct has a second bend near the second air outlet, with the auxiliary heating device disposed at the second bend.
[0017] In some feasible embodiments of the heat pump dryer described above, the drying air duct is located at the bottom and back of the heat pump dryer.
[0018] Since the aforementioned heat pump dryer is equipped with the aforementioned auxiliary heating device for heat pump dryers, it possesses all the technical effects that the aforementioned auxiliary heating device for heat pump dryers can achieve, which will not be elaborated here. Attached Figure Description
[0019] The preferred embodiments of this utility model are described below with reference to the accompanying drawings, in which:
[0020] Figure 1 This is a schematic diagram of the auxiliary heating device of this utility model;
[0021] Figure 2 This is a cross-sectional view of the auxiliary heating device of this utility model;
[0022] Figure 3 This is a cross-sectional view of the casing of this utility model;
[0023] Figure 4 This is an exploded view of the heating film of this utility model;
[0024] Figure 5 This is one of the structural schematic diagrams of the heating film and heat diffusion component of this utility model;
[0025] Figure 6 This is the second schematic diagram of the structure of the heating film and heat diffusion component of this utility model;
[0026] Figure 7 This is a structural schematic diagram of the heat pump dryer of this utility model;
[0027] Figure 8 yes Figure 7 A magnified view of a portion of point A in the middle;
[0028] Figure 9 Based on Figure 7 A diagram illustrating the working principle of a heat pump dryer.
[0029] List of reference numerals in the attached diagram:
[0030] 1-Auxiliary heating device; 11-Housing shell; 111-Auxiliary air duct; 1111-First air inlet; 1112-First air outlet; 112-Direct current section; 113-First turning section; 12-Heating film; 121-Heating layer; 122-First protective layer; 123-Second protective layer; 124-Flexible electrode; 125-Thermistor; 126-Wire; 13-Heat diffusion component; 131-Substrate; 132-Fin structure; 2-Drying air duct; 21-Second air inlet; 22-Second air outlet; 23-Second turning section; 3-Condenser; 4-Evaporator; 5-Fan; 6-Cylinder; 7-Outer shell. Detailed Implementation
[0031] Preferred embodiments of the present invention will now be described with reference to the accompanying drawings. Those skilled in the art should understand that these embodiments are merely illustrative of the technical principles of the present invention and are not intended to limit the scope of protection of the present invention.
[0032] It should be noted that in the description of this utility model, terms such as "upper", "lower", "inner", and "outer" that indicate direction or positional relationship are based on the direction or positional relationship shown in the accompanying drawings. This is only for the convenience of description and does not indicate or imply that the device or element must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, it should not be construed as a limitation of this utility model.
[0033] Furthermore, it should be noted that in the description of this utility model, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection, a direct connection, or an indirect connection through an intermediate medium; they can refer to the internal connection of two components, and so on. Those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances. In addition, numerical terms such as "first," "second," etc., used herein are primarily (only) used to distinguish multiple similar objects, quantities, or processes; that is, they do not necessarily indicate any dependency and / or order between these objects, quantities, or processes. If a dependency and / or order is required, it will be explicitly stated in the context, or it will be obvious to those skilled in the art when understanding the specific embodiments.
[0034] To improve drying efficiency, existing heat pump dryers typically incorporate auxiliary heating devices within the drying duct. Traditional auxiliary heating devices often use resistance wires as the heat source, but this type of device suffers from problems such as excessively high operating temperatures and uneven heating, with localized areas easily exceeding the critical value of 470℃. If the heat pump dryer uses R290 refrigerant, R290 has a high flammability and explosion risk under specific conditions (such as an R290 concentration of 2.1%–9.5% in the air and an ambient temperature ≥470℃). In the event of a refrigerant leak, the high-temperature resistance wire in the traditional auxiliary heating device could easily ignite the refrigerant, leading to combustion or explosion accidents, posing a serious safety hazard.
[0035] To address the problem of refrigerant leakage leading to combustion or explosion accidents in existing heat pump dryers using R290 refrigerant, which, when an auxiliary heating device with a resistance wire as the heat source is added, causes such accidents, this utility model provides an auxiliary heating device 1 for a heat pump dryer. For example... Figure 1 As shown, the auxiliary heating device 1 of the heat pump dryer of this utility model includes a housing 11, a heat diffusion component 13 and a heating film 12. The heat diffusion component 13 is disposed inside the housing 11, and the heating film 12 is attached to the heat diffusion component 13 so as to conduct heat to the heat diffusion component 13.
[0036] like Figures 2 to 3 As shown, the housing 11 has an auxiliary air duct 111 inside. The auxiliary air duct 111 has a first air inlet 1111 and a first air outlet 1112. The housing 11 includes a direct flow section 112 and a first bend section 113 that are interconnected. The first air inlet 1111 is formed at the free end of the direct flow section 112, and the first air outlet 1112 is formed at the free end of the first bend section 113. A heat diffusion member 13 and a heating film 12 are disposed at the first air inlet 1111 and are located inside the direct flow section 112. The dimensions of the heat diffusion member 13 and the heating film 12 are adapted to the cross-sectional shape of the first air inlet 1111. The airflow path of the auxiliary air duct 111 is as follows: air enters the direct flow section 112 from the first air inlet 1111, passes through the heat diffusion member 13 with the heating film 12 attached, enters the first bend section 113, and finally flows out from the first air outlet 1112.
[0037] like Figure 4As shown, the heating film 12 of this invention includes a heating layer 121, a first protective layer 122, and a second protective layer 123, with the heating layer 121 sandwiched between the first protective layer 122 and the second protective layer 123. Specifically, the heating layer 121 is a carbon nanotube heating layer and / or a rare earth nanotube heating layer; the first protective layer 122 is a polyethylene terephthalate (PET) protective layer, a polypropylene (PP) protective layer, and / or a polyimide (PI) protective layer; and the second protective layer 123 is a polyethylene terephthalate protective layer, a polypropylene protective layer, and / or a polyimide protective layer.
[0038] Specifically, the heating layer 121 of this utility model is a carbon nanotube heating layer.
[0039] It should be noted that carbon nanotubes (CNTs) are a novel type of heating material capable of efficiently releasing heat through infrared radiation when energized. Specifically, when carbon nanotubes are energized and reach a temperature of tens of degrees Celsius, the electrons outside the nuclei of their carbon atoms undergo energy level transitions due to the temperature. During these transitions, a large amount of infrared radiation is released, thus releasing heat outwards through infrared radiation. Infrared radiation travels in a straight line, requiring no air or other medium to transfer energy, and is almost entirely unabsorbed by molecules in the air. Substances that absorb infrared radiation experience increased vibrations in their atoms or molecules, manifesting as a rise in temperature. Understandably, the technology for carbon nanotube heating layers is relatively mature and will not be elaborated upon further here.
[0040] The carbon nanotube heating layer of this invention, as a heat source for the auxiliary heating device 1, has the following advantages: First, its operating temperature is generally around 200℃, which is relatively low. Even under extreme conditions of dry burning, the temperature is below 350℃, far below the 470℃ deflagration threshold of R290 refrigerant, resulting in higher safety performance. Second, it has high heating efficiency, with a faster heating rate than traditional resistance wires, which helps reduce the overall energy consumption of the equipment. Third, it has a simple structure and low air resistance.
[0041] Alternatively, the heating layer 121 of this invention can also be a rare earth nanotube heating layer.
[0042] It should be noted that rare-earth nanotubes are a novel type of heating material capable of efficiently releasing heat through infrared radiation when energized. Specifically, when an electric current is applied to the rare-earth nanotubes, electrons in the rare-earth elements (such as lanthanum, cerium, and neodymium) are excited and undergo energy level transitions, releasing a large amount of infrared radiation, thus releasing heat outwards through infrared radiation. Infrared radiation travels in a straight line, requiring no air or other medium to transfer energy, and is hardly absorbed by molecules in the air. Substances that absorb infrared radiation experience increased vibrations in their atoms or molecules, manifesting as a rise in temperature. Understandably, the technology for rare-earth nanotube heating layers is relatively mature and will not be elaborated upon further here.
[0043] The rare-earth nanotube heating layer of this invention, as a heat source for the auxiliary heating device 1, has the following advantages: First, its operating temperature is 50–80℃, suitable for medium and low temperature environments, far below the 470℃ deflagration critical value of R290 refrigerant. Furthermore, rare-earth elements have high thermal stability, maintaining their heating performance over long periods of use, resulting in higher safety. Second, it has high heating efficiency, with a faster heating rate than traditional resistance wires, helping to reduce the overall energy consumption of the equipment. Third, its structure is simple, with low airflow resistance.
[0044] Alternatively, the heating layer 121 of this invention can also be a composite heating layer formed by a carbon nanotube heating layer and a rare earth nanotube heating layer.
[0045] Furthermore, the heating film 12 also includes wires 126, and a flexible electrode 124 and a thermistor 125, which are electrically connected to the wires 126, are disposed on the heating layer 121. The flexible electrode 124 is electrically connected to the heating layer 121 to supply power to the heating layer 121. The thermistor 125 is used to detect the real-time temperature of the heating layer 121. Specifically, by detecting the resistance value of the thermistor 125 in real time, the real-time temperature of the heating layer 121 can be indirectly calculated.
[0046] like Figures 5 to 6 As shown, there are two heat diffusion components 13, which are respectively attached to both sides of the heating film 12.
[0047] Specifically, the heat diffusion component 13 includes a substrate 131 and a fin structure 132. The heating film 12 is attached to one side of the substrate 131, and the fin structure 132 is disposed on the other side of the substrate 131, that is, the fin structure 132 is disposed on the side of the substrate 131 away from the heating film 12. Specifically, the fin structure 132 is composed of multiple fins, with a certain spacing between adjacent fins to allow airflow. The thickness of the fins is 1mm to 3mm, preferably 2mm; the spacing between adjacent fins is 5mm to 10mm, preferably 6mm.
[0048] The auxiliary heating device 1 of the heat pump dryer provided by this utility model, by setting a heating film 12 containing a carbon nanotube heating layer and / or a rare earth nanotube heating layer, can conduct heat to the heat diffusion component 13 by infrared radiation. In this way, when the heating layer 121 is working, the working temperature is much lower than the deflagration critical value of 470°C for R290 refrigerant. Compared with traditional resistance wire, it has higher safety performance, thereby avoiding combustion or explosion accidents in the event of refrigerant leakage in the heat pump dryer.
[0049] This utility model embodiment also provides a heat pump dryer, such as Figures 7 to 9 As shown, the heat pump dryer includes a drying duct 2, a fan 5, a drum 6, a heat pump system, and a casing 7. The drying duct 2, fan 5, drum 6, and heat pump system are all housed within the casing 7. Specifically, the drying duct 2 is located at the bottom and back of the heat pump dryer, i.e., below and behind the drum 6. The drying duct 2 has a second air inlet 21 and a second air outlet 22, which are interconnected with the drum 6. The heat pump system includes a condenser 3, an evaporator 4, a compressor, and a throttling device. The fan 5, evaporator 4, and condenser 3 are arranged sequentially within the drying duct 2 and below the drum 6, following the airflow direction within the drying duct 2. The condenser 3 heats the air within the drying duct 2, and the evaporator 4 condenses water vapor in the humid air into liquid water.
[0050] Continue to refer to Figures 7 to 9 The heat pump dryer of this utility model also includes an auxiliary heating device 1 of the heat pump dryer mentioned above. The auxiliary heating device 1 is installed in the drying air duct 2 and is located downstream of the condenser 3.
[0051] Further reference Figures 7 to 9 The drying air duct 2 has a second bend 23 near the second air outlet 22, and the auxiliary heating device 1 is disposed in the second bend 23. Specifically, the first bend 113 of the housing 11 is disposed at the second bend 23 of the drying air duct 2, and the outer contour shape of the first bend 113 is adapted to the inner contour shape of the second bend 23.
[0052] Further reference Figures 7 to 9 The outer diameter of the housing 11 of the auxiliary heating device 1 is smaller than the inner diameter of the second bend 23 of the drying air duct 2, so that part of the airflow in the drying air duct 2 passes through the auxiliary air duct 111. With the above arrangement, while ensuring that the outlet air temperature meets the standard, reducing the outer diameter of the housing 11 can reduce the air resistance in the drying air duct 2, which helps to reduce the overall energy consumption of the equipment.
[0053] The working principle of this heat pump dryer is as follows: Under the action of the fan 5, air flows in the drying duct 2. When the air flows to the condenser 3, it is heated to form dry hot air and flows to the second air outlet 22. Subsequently, near the second air outlet 22, part of the dry hot air flows to the second air outlet 22 through the second bend 23, and another part of the dry hot air flows into the auxiliary duct 111 and is reheated by the auxiliary heating device 1, and then merges with the dry hot air in the second bend 23, thereby increasing the air temperature near the second air outlet 22. Then, the dry hot air enters the drum 6 through the second air outlet 22 and comes into contact with the wet clothes, thereby evaporating the moisture in the clothes into water vapor, thus forming humid hot air. Then, the humid hot air enters the drying duct 2 from the drum 6 through the second air inlet 21. When it passes through the evaporator 4, the water vapor in it condenses and precipitates out, thereby forming dry air. The dry air flows through the condenser 3 again for heating to begin the next cycle of circulation until the clothes inside the drum 6 are completely dried.
[0054] It is understandable that since the heat pump dryer is equipped with the aforementioned auxiliary heating device 1 of the heat pump dryer, it possesses all the technical effects of the aforementioned auxiliary heating device 1 of the heat pump dryer, which will not be elaborated here.
[0055] The technical solution of this utility model has been described in conjunction with the preferred embodiments shown in the accompanying drawings. However, it will be readily understood by those skilled in the art that the protection scope of this utility model is obviously not limited to these specific embodiments. Without departing from the principle of this utility model, those skilled in the art can make equivalent changes or substitutions to the relevant technical features, and the technical solutions after these changes or substitutions will all fall within the protection scope of this utility model.
Claims
1. An auxiliary heating device for a heat pump dryer, characterized in that, The auxiliary heating device (1) includes a heating film (12) and a heat diffusion component (13). The heating film (12) is attached to the heat diffusion component (13) to conduct heat to the heat diffusion component (13). The heating film (12) includes a heating layer (121), which is a carbon nanotube heating layer and / or a rare earth nanotube heating layer.
2. The auxiliary heating device for the heat pump dryer according to claim 1, characterized in that, The heating film (12) further includes a first protective layer (122) and a second protective layer (123), with the heating layer (121) sandwiched between the first protective layer (122) and the second protective layer (123).
3. The auxiliary heating device for the heat pump dryer according to claim 1, characterized in that, There are two heat diffusion components (13), and the two heat diffusion components (13) are respectively attached to both sides of the heating film (12).
4. The auxiliary heating device for the heat pump dryer according to claim 3, characterized in that, The heat diffusion component (13) includes a substrate (131) and a fin structure (132), wherein the fin structure (132) is disposed on the side of the substrate (131) away from the heating film (12).
5. The auxiliary heating device for the heat pump dryer according to claim 1, characterized in that, The auxiliary heating device (1) also includes a housing (11), and an auxiliary air duct (111) is constructed inside the housing (11). The heat diffusion component (13) is disposed inside the auxiliary air duct (111).
6. The auxiliary heating device for the heat pump dryer according to claim 5, characterized in that, The auxiliary air duct (111) has a first air inlet (1111) and a first air outlet (1112). The housing (11) includes a direct current section (112) and a first turning section (113) that are interconnected. The first air inlet (1111) is formed on the direct current section (112), and the first air outlet (1112) is formed on the first turning section (113).
7. The auxiliary heating device for a heat pump dryer according to claim 6, characterized in that, The heat diffusion component (13) and the heating film (12) are disposed at the first air inlet (1111), and their dimensions are adapted to the cross-sectional shape of the first air inlet (1111).
8. A heat pump dryer, characterized in that, The heat pump dryer includes an auxiliary heating device of the heat pump dryer according to any one of claims 1 to 7, and the heat pump dryer further includes a drying air duct (2), wherein the auxiliary heating device (1) is disposed in the drying air duct (2).
9. The heat pump dryer according to claim 8, characterized in that, The drying duct (2) has a second air outlet (22), and the drying duct (2) has a second bend (23) near the second air outlet (22), and the auxiliary heating device (1) is provided in the second bend (23).
10. The heat pump dryer according to claim 8, characterized in that, The drying air duct (2) is located at the bottom and back of the heat pump dryer.