Heater and refrigeration device

Abstract

The embodiment of the present application discloses a heater and a refrigeration device, and relates to the technical field of household appliances. The heater is used for defrosting an evaporator of the refrigeration device. The heater comprises a metal tube, an insulating part, a heating wire, a conductive rod and a pressure-sensitive resistor. The metal tube is electrically connected with a grounding end of the refrigeration device, and the insulating part is filled in the metal tube. The heating wire is embedded in the insulating part. At least a part of the conductive rod is located in the metal tube and is electrically connected with the heating wire, and the conductive rod is used for being electrically connected with a power supply of the refrigeration device. The pressure-sensitive resistor is sleeved on the part of the conductive rod located in the metal tube and is in contact with an inner wall of the metal tube. When a voltage between the conductive rod and the metal tube is less than a set voltage threshold, the pressure-sensitive resistor electrically isolates the conductive rod and the metal tube. When the voltage between the conductive rod and the metal tube is greater than or equal to the set voltage threshold, the pressure-sensitive resistor electrically connects the conductive rod and the metal tube. The embodiment of the present application can reduce the risk of short circuit of the heater caused by a surge and improve the use safety of the heater.

Description

Technical Field

[0001] Embodiments of this application relate to the technical field of electric heating, and more particularly to a heater and a refrigeration device. Background Technology

[0002] The heater may include a metal tube, an insulating part, a heating wire, and a conductive rod. The insulating part is filled inside the metal tube, the heating wire is embedded in the insulating part, and the conductive rod connects the heating wire and the power source.

[0003] When a surge occurs in the circuit, the surge voltage can easily break down the insulation, causing a short circuit between the metal tube and the conductive rod or heating wire, which affects the safety and reliability of the heater. Utility Model Content

[0004] Embodiments of this application provide a heater and a cooling device that can reduce the risk of short circuits between metal tubes and conductive rods or heating wires caused by surge voltage, thereby improving the safety and reliability of the heater.

[0005] On one hand, embodiments of this application provide a heater for defrosting the evaporator of a refrigeration device. The heater includes a metal tube, an insulating portion, a heating wire, a conductive rod, and a varistor. The metal tube is electrically connected to the grounding terminal of the refrigeration device. The insulating portion is filled within the metal tube. The heating wire is embedded within the insulating portion. At least a portion of the conductive rod is located within the metal tube and is electrically connected to the heating wire; the conductive rod is used for electrical connection to a power source. The varistor is sleeved on the portion of the conductive rod located within the metal tube and is in contact with the inner wall of the metal tube. The varistor is configured to: electrically isolate the conductive rod and the metal tube when the voltage between them is less than a set voltage threshold; and electrically connect them when the voltage between them is greater than or equal to the set voltage threshold.

[0006] Understandably, when a surge exists in the circuit, the surge will be conducted to the heater via the conductive rod. When the voltage between the conductive rod and the metal tube is less than the set voltage threshold, it can be determined that no surge is conducted to the heater. At this time, the resistance value of the varistor is large enough to electrically isolate the conductive rod and the metal tube, and the heater can work normally.

[0007] When the voltage between the conductive rod and the metal tube is greater than or equal to a set voltage threshold, it can be determined that the surge is conducted to the heater. At this point, the resistance of the varistor is relatively low, enabling it to electrically connect the conductive rod and the metal tube. Understandably, the metal tube is electrically connected to the grounding terminal, allowing the conductive rod to be grounded through the metal tube, thereby transmitting the surge to the grounding terminal.

[0008] In other words, a varistor is installed inside the metal tube on the part of the conductive rod and in contact with the inner wall of the metal tube. This allows the varistor to electrically connect the conductive rod and the metal tube when a surge is conducted to the heater, and to electrically connect the metal tube and the grounding terminal, thereby transmitting the surge to the grounding terminal.

[0009] This reduces the risk of surge voltage breaking down the insulation, thereby reducing the risk of short circuits between the metal tube and the conductive rod or heating wire, and improving the safety and reliability of the heater.

[0010] Compared to setting the varistor on the circuit board, the embodiments of this application sleeve the varistor in the part of the conductive rod located inside the metal tube, so that the varistor does not need to occupy additional space on the circuit board, reducing the number of components on the circuit board and facilitating the miniaturization of the circuit board.

[0011] In some possible implementations, the varistor has a tubular structure, and the tube wall includes a first conductive layer, a second conductive layer, and a varistor material. The first conductive layer is fitted over the portion of the conductive rod located inside the metal tube. The second conductive layer surrounds the first conductive layer and is in contact with the inner wall of the metal tube. The varistor material is filled between the first and second conductive layers.

[0012] This configuration allows the varistor to have a ring structure. Understandably, the first and second conductive layers conduct electricity and protect the varistor material. The resistance of the varistor material changes with the applied voltage, allowing the varistor's resistance to change with the voltage between the metal tube and the conductive rod, thus electrically connecting the conductive rod and the metal tube when a surge is conducted to the heater.

[0013] In some possible implementations, the first conductive layer includes a first body portion and a first protrusion. The first body portion is fitted over the portion of the conductive rod located inside the metal tube, and a first gap exists between the first body portion and the outer surface of the conductive rod. The first protrusion is connected to the first body portion and located within the first gap, and the first protrusion is in contact with the outer surface of the conductive rod. And / or, the second conductive layer includes a second body portion and a second protrusion. The second body portion surrounds the first body portion, and a second gap exists between the second body portion and the inner wall of the metal tube. The second protrusion is connected to the second body portion and located within the second gap, and the second protrusion is in contact with the inner wall of the metal tube.

[0014] The first conductive layer includes a first body portion and a first protrusion portion, which can reduce the friction between the first conductive layer and the outer surface of the conductive rod during the process of putting the varistor on the conductive rod, and improve the convenience of putting the varistor on the conductive rod.

[0015] The second conductive layer includes a second body portion and a second protrusion portion, which can reduce the friction between the second conductive layer and the inner wall of the metal tube during the process of placing the varistor inside the metal tube, thereby improving the convenience of placing the varistor inside the metal tube.

[0016] In some possible implementations, when the first conductive layer includes a first body portion and a first protrusion, the heater further includes a first filling portion that fills the first gap. When the second conductive layer includes a second body portion and a second protrusion, the heater further includes a second filling portion that fills the second gap.

[0017] By setting the first filling part to fill the first gap, the risk of the first body part deforming toward the first gap due to external force can be reduced, which is beneficial to improving the mechanical strength of the heater.

[0018] By providing a second filling part to fill the second gap, the risk of the second body part deforming toward the second gap due to external force can be reduced, and the risk of the metal tube denting into the second gap can be reduced, which is beneficial to improving the mechanical strength of the heater.

[0019] In some possible implementations, the conductive rod is electrically connected to a power supply via a rectifier unit of the cooling device, which converts the alternating current (AC) output from the power supply into direct current (DC). The conductive rod includes a first conductive rod and a second conductive rod. At least a portion of the first conductive rod is located inside a metal tube and electrically connected to a heating wire; the first conductive rod is used for electrical connection to the positive terminal of the rectifier unit. At least a portion of the second conductive rod is located inside a metal tube and electrically connected to the heating wire; the second conductive rod is used for electrical connection to the negative terminal of the rectifier unit. A varistor is sleeved on at least one of the first and second conductive rods.

[0020] The conductive rods include a first conductive rod and a second conductive rod, so that after the current flows out from the positive terminal of the rectifier unit, it can flow into the heating wire through the first conductive rod, so that the heating wire can generate heat, and then flow back to the negative terminal of the rectifier unit through the second conductive rod.

[0021] When there are two varistors, one varistor is sleeved on the first conductive rod and the other varistor is sleeved on the second conductive rod, so that the first and second conductive rods can be connected to the metal tube through the varistors respectively. This allows surge currents in different directions to be guided to the grounding terminal, reducing the risk of surge voltage breaking down the insulation and improving the safety and reliability of the heater.

[0022] Alternatively, there can be only one varistor. In this case, the varistor can be mounted on the first or second conductive rod to simplify the structure of the heater and reduce its cost.

[0023] By setting the varistor to be sleeved on at least one of the first and second conductive rods, the flexibility of the varistor setting is improved, meeting different usage requirements.

[0024] In some possible implementations, the refrigeration device also includes a relay connected between the first conductive rod and the positive terminal of the rectifier unit, used to control the connection or disconnection of the first conductive rod and the positive terminal of the rectifier unit. A single varistor is included and mounted on the second conductive rod.

[0025] The first conductive rod is electrically connected to the positive terminal of the rectifier unit via a relay. The relay controls the connection or disconnection between the first conductive rod and the rectifier unit. The heater operates normally when the relay is on and stops operating when the relay is off.

[0026] Understandably, when the relay is disconnected, the surge current cannot enter the heater via the first conductive rod. Furthermore, the heater does not need to continuously defrost the evaporator; it only needs to operate for about 0.5 hours per day, making the probability of surge current entering the heater via the first conductive rod relatively low.

[0027] In this way, the number of varistors can be set to one and placed on the second conductive rod, reducing the risk of surge current entering the heater through the second conductive rod, improving the safety and reliability of the heater, simplifying the heater structure, and reducing the cost of the heater.

[0028] In some possible implementations, the heater further includes a first sealing portion and a second sealing portion. The first sealing portion is fitted over the portion of the conductive rod located inside the metal tube and contacts the inner wall of the metal tube. Along the extension direction of the metal tube, the first sealing portion is located between the varistor and the insulating portion, and is an insulating element. The second sealing portion is fitted over the portion of the conductive rod located inside the metal tube and contacts the inner wall of the metal tube. Along the extension direction of the metal tube, the second sealing portion is located on the side of the varistor away from the first sealing portion, and seals the opening of the metal tube. The second sealing portion is also an insulating element.

[0029] The first sealing part isolates the insulating part from the varistor, thus providing a seal and reducing the risk of leakage of the insulating part from the metal tube. Furthermore, as an insulating component, the first sealing part provides electrical isolation, reducing the risk of short circuits between the conductive rod and the metal tube.

[0030] The second sealing part can seal the opening of the metal tube, reducing the risk of the varistor, insulating part, and conductive rod falling out of the metal tube. Furthermore, the second sealing part is an insulating component, providing electrical isolation and reducing the risk of a short circuit between the conductive rod and the metal tube.

[0031] In some possible implementations, the insulating material includes magnesium oxide.

[0032] Understandably, magnesium oxide has good insulation properties, ensuring the insulation effect of the insulating part and reducing the risk of short circuits between the heating wire and the metal tube. In addition, magnesium oxide has good thermal conductivity, which can conduct the heat dissipated by the heating wire to the metal tube, improving the heating performance of the heater.

[0033] In some possible implementations, a portion of the conductive rod is located inside the metal tube, while another portion extends outside the metal tube through its opening. The heater also includes an insulating protective sleeve fitted over the portion of the metal tube and the portion of the conductive rod that is outside the metal tube.

[0034] By adopting the above-described configuration, on the one hand, the portion of the metal tube near the opening and the portion of the conductive rod outside the metal tube can be electrically isolated, reducing the risk of a short circuit between them. On the other hand, it can protect both the portion of the metal tube near the opening and the portion of the conductive rod outside the metal tube.

[0035] On the other hand, embodiments of this application provide a refrigeration device. The refrigeration device includes a housing, a refrigeration system, a control board, and a heater as described above. The housing encloses a storage chamber and an evaporation chamber, which are connected. The refrigeration system includes a compressor, a condenser, and an evaporator connected in sequence via pipes. The evaporator is located within the evaporation chamber and provides cooling to the storage chamber. The control board includes a circuit board and a rectifier unit. The circuit board is electrically connected to a power source. The rectifier unit is mounted on the circuit board and converts the alternating current (AC) output from the power source into direct current (DC). The heater is located within the evaporation chamber, and its conductive rod is electrically connected to the output of the rectifier unit. The heater is used to defrost the evaporator.

[0036] The refrigeration equipment provided in the embodiments of this application includes the heater as described above, and therefore has all the above-described beneficial effects, which will not be repeated here. Attached Figure Description

[0037] Figure 1 This is a schematic diagram of the structure of a refrigeration device provided in some embodiments of this application; Figure 2 Schematic diagrams of the structure of the refrigeration system and heater provided in some embodiments of this application; Figure 3 Schematic diagrams of the heater provided in some embodiments of this application; Figure 4 for Figure 3 A schematic diagram of the exploded structure of the heater in some embodiments; Figure 5 for Figure 3 A schematic diagram of the cross-sectional structure along the A1-A1 direction; Figure 6 for Figure 5 A magnified schematic diagram of a portion of the E1 region; Figure 7 A schematic diagram showing the connection relationship between the filter unit, the rectifier unit, and the heater provided in some embodiments of this application; Figure 8 for Figure 3 A schematic diagram of the cross-sectional structure along the A2-A2 direction; Figure 9 This is a schematic diagram of the structure of a varistor provided in some embodiments of this application; Figure 10 for Figure 9 A schematic diagram of the cross-sectional structure along the A3-A3 direction.

[0038] Explanation of icon numbers: 100 - Heater, 110 - Metal tube, 1101 - Inner wall of metal tube 110, 130 - Heating wire, 140 - Conductive rod, 141 - First conductive rod, 142 - Second conductive rod, 150 - Varistor, 1511 - First conductive layer, 1511a - First body part, 1511b - First protrusion, 1512 - Second conductive layer, 1512a - Second body part, 1512b - Second protrusion, 1513 - Varistor material, 171 - First sealing part, 172 - Second sealing part, 180 - Insulating protective sleeve, 181 - First insulating protective sleeve, 182 - Second insulating protective sleeve, 190- Reinforcing member, 200- Refrigeration equipment, 210- Box body, 211- Storage room, 211a- Refrigerated room, 211b- Freezer room, 220- Refrigeration system, 221- Pipe, 222- Compressor, 223- Evaporator, 224- Condenser, 230- Rectifier unit, 240- Relay, 260- Filter unit, 250- Door body, 251- First door body, 252- Second door body, CX1- First capacitor, CX2- Second capacitor, CY1- Third capacitor, CY2- Fourth capacitor, P1- First gap, P2- Second gap. Detailed Implementation

[0039] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all possible embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0040] In the embodiments of this application, the terms "exemplary" or "for example" are used to indicate that something is an example, illustration, or description. Any embodiment or design that is described as "exemplary" or "for example" in the embodiments of this application should not be construed as being more preferred or advantageous than other embodiments or designs. Specifically, the use of the terms "exemplary" or "for example" is intended to present the relevant concepts in a specific manner.

[0041] As used herein, terms such as “equal,” “parallel,” and “perpendicular” include the described situation and situations that are similar to the described situation, within an acceptable range of deviation, which is determined by those skilled in the art taking into account the measurement under discussion and the errors associated with the measurement of a particular quantity (i.e., the limitations of the measurement system). For example, “equal” includes absolute equality and approximate equality, where an acceptable range of deviation for approximate equality may be, for example, a difference between the two equal items less than or equal to 5% of either one.

[0042] In the embodiments of this application, the directional indications used to explain the structure and movement of different components, such as up, down, left, right, front, and back, are relative. These indications are appropriate when the components are in the positions shown in the figures. However, if the description of the component positions changes, these directional indications will also change accordingly.

[0043] Figure 1 The diagram shows the structure of a refrigeration device provided in some embodiments of this application. Figure 1 As shown, an embodiment of this application provides a refrigeration device 200. For example, the refrigeration device 200 can be a refrigerator or a freezer; the embodiments of this application do not further limit the specific form of the refrigeration device 200.

[0044] In some examples, such as Figure 1 As shown, the refrigeration equipment 200 includes a housing 210, which can enclose a storage room 211.

[0045] Understandably, storage compartment 211 is used for storing items. The housing 210 can enclose one storage compartment 211 or multiple storage compartments 211. When the housing 210 encloses multiple storage compartments 211, the multiple storage compartments 211 may include a refrigerator compartment 211a and a freezer compartment 211b, the temperature of the freezer compartment 211b may be lower than the temperature of the refrigerator compartment 211a. Alternatively, the multiple storage compartments 211 may also include other chambers besides the refrigerator compartment 211a and the freezer compartment 211b. The embodiments of this application do not further limit the number and function of the storage compartments 211.

[0046] Continue to refer to Figure 1The refrigeration equipment 200 may also include a door 250, which is rotatably connected to the cabinet 210 for opening or closing the opening of the storage room 211.

[0047] When the cabinet 210 encloses the refrigerator compartment 211a and the freezer compartment 211b, the door 250 may include a first door 251 and a second door 252. The first door 251 is used to open or close the opening of the refrigerator compartment 211a, and the second door 252 is used to open or close the opening of the freezer compartment 211b.

[0048] The number of first doors 251 can be one or more, for example, two. When there are two first doors 251, the two first doors 251 can jointly close the opening of the refrigerator compartment 211a. The number of second doors 252 can also be one or more, for example, two. When there are two second doors 252, the two second doors 252 can jointly close the opening of the freezer compartment 211b.

[0049] Figure 2 The diagram shows a simplified structural representation of a refrigeration system and heater provided in some embodiments of this application. In some examples, such as... Figure 2 As shown, the refrigeration equipment 200 also includes a refrigeration system 220, which provides cooling capacity to the storage compartment 211. The refrigeration system 220 includes a compressor 222, a condenser 224, and an evaporator 223 connected in sequence via pipes 221. Understandably, the refrigerant can circulate between the compressor 222, the condenser 224, and the evaporator 223 to achieve refrigeration.

[0050] For example, compressor 222 can compress refrigerant into high-temperature and high-pressure gaseous refrigerant, which can flow into condenser 224 through pipe 221 and release heat in condenser 224 to become medium-temperature and high-pressure liquid refrigerant.

[0051] Medium-temperature, high-pressure liquid refrigerant flows into a throttle valve (not shown in the figure) via pipe 221, where it becomes a low-temperature, low-pressure liquid refrigerant (or a gas-liquid mixture). It then flows into the evaporator 223 via pipe 221, where it evaporates and absorbs heat before flowing back to the compressor 222. Understandably, the process of refrigerant evaporating and absorbing heat in the evaporator 223 provides cooling to the storage compartment 211.

[0052] For example, the refrigerant may include at least one of Freon, hydrofluorocarbons and hydrofluoroolefins, and the embodiments of this application do not further limit the specific form of the refrigerant.

[0053] In some examples, the housing 210 may also enclose an evaporation chamber (not shown in the figure), and the storage chamber 211 is connected to the evaporation chamber. An evaporator 223 is disposed in the evaporation chamber and is used to provide cooling to the storage chamber 211.

[0054] Evaporator 223 is located in the evaporation chamber, so that the refrigerant can absorb heat from the evaporation chamber during the evaporation process in evaporator 223. The evaporation chamber and the storage chamber 211 are connected, so that evaporator 223 can provide cooling capacity to storage chamber 211.

[0055] Understandably, during the cooling process of the refrigeration equipment 200, water vapor in the air will condense into frost at the evaporator 223. The longer the refrigeration equipment 200 operates, the more frost will condense at the evaporator 223. Frost will affect the evaporation efficiency of the evaporator 223, therefore, the evaporator 223 needs to be defrosted.

[0056] In some examples, such as Figure 2 As shown, the refrigeration equipment 200 also includes a heater 100 for defrosting the evaporator 223 of the refrigeration equipment 200.

[0057] Understandably, heater 100 is capable of converting electrical energy into heat energy. For example, heater 100 may be a heat pipe heater. In some examples, heater 100 is positioned within an evaporation chamber, enabling it to defrost evaporator 223.

[0058] The embodiments of this application do not further limit other components of the refrigeration equipment 200; the heater 100 is described below as an example.

[0059] Figure 3 This is a schematic diagram of the structure of a heater provided in some embodiments of this application. Figure 4 for Figure 3 The heater in some embodiments is shown in the exploded structure diagram.

[0060] In some examples, such as Figure 3 and Figure 4 As shown, the heater 100 includes a metal tube 110, an insulating part (not shown) heating wire 130, and a conductive rod 140.

[0061] The metal pipe 110 can be a steel pipe, a copper pipe, or a metal pipe made of other metal materials. The metal pipe 110 can be a round pipe, a square pipe, or other regular or irregular tubular structures. The embodiments of this application do not further limit the material and shape of the metal pipe 110.

[0062] The metal tube 110 can extend in one direction or bend and extend in multiple directions. The embodiments of this application do not further limit the extension direction of the metal tube 110.

[0063] In some examples, the insulation is filled inside the metal tube 110, and the heating wire 130 is embedded inside the insulation.

[0064] The heating wire 130 can be a metal wire, enabling it to conduct electricity. Furthermore, the heating wire 130 can have a relatively high resistance, allowing it to convert electrical energy into heat energy. The length of the heating wire 130 can be slightly less than the length of the metal tube 110, ensuring that most of the heater 100 can generate heat.

[0065] Understandably, in the accompanying drawings of this application, the following characters are used... Figure 4 For example, only a portion of the heating wire 130 is shown, and the length of the heating wire 130 in the embodiments of this application is not limited.

[0066] The insulating part can serve as an electrical isolation component. The heating wire 130 is embedded in the insulating part, which can reduce the risk of short circuit between the heating wire 130 and the metal tube 110.

[0067] In some examples, the insulation material includes magnesium oxide.

[0068] Understandably, magnesium oxide has good insulation properties, ensuring the insulation effect of the insulating part and reducing the risk of short circuit between the heating wire 130 and the metal tube 110. In addition, magnesium oxide has good thermal conductivity, which can conduct the heat dissipated by the heating wire 130 to the metal tube 110, improving the heating performance of the heater 100.

[0069] For example, the insulation may include magnesium oxide powder to improve the ease of filling the insulation into the metal tube 110.

[0070] Figure 5 for Figure 3 A schematic diagram of the cross-sectional structure along the A1-A1 direction. Figure 6 for Figure 5 A magnified schematic diagram of the E1 region.

[0071] In some examples, such as Figure 5 and Figure 6 As shown, at least a portion of the conductive rod 140 is located inside the metal tube 110 and is electrically connected to the heating wire 130.

[0072] Understandably, the conductive rod 140 can be entirely located inside the metal tube 110, or the conductive rod 140 can be partially located inside the metal tube 110.

[0073] In some examples, such as Figure 6 As shown, a portion of the conductive rod 140 is located inside the metal tube 110, and another portion of the conductive rod 140 extends outside the metal tube 110 through the opening of the metal tube 110.

[0074] For ease of description, the portion of the conductive rod 140 located inside the metal tube 110 can be referred to as the first part of the conductive rod, and the portion of the conductive rod 140 located outside the metal tube 110 can be referred to as the second part of the conductive rod. A portion of the first part of the conductive rod can be embedded in the insulating part and electrically connected to the heating wire 130, while the other portion of the first part of the conductive rod can be exposed outside the insulating part and extend to the opening of the metal tube 110.

[0075] For example, the heating wire 130 may be wound around and electrically connected to the conductive rod 140 located within the insulating portion, or the heating wire 130 may be embedded in and electrically connected to the conductive rod 140 located within the insulating portion.

[0076] In some examples, the conductive rod 140 is electrically connected to the power supply.

[0077] The power supply can output alternating current (AC). For example, the power supply can output 220V (volts) AC. The conductive rod 140 can be directly connected to the power supply or indirectly connected to the power supply through other circuit structures.

[0078] Understandably, the conductive rod 140 is electrically connected to the power supply, so that the current output by the power supply can flow through the conductive rod 140 to the heating wire 130, thereby enabling the heating wire 130 to generate heat.

[0079] Figure 7 This is a schematic diagram showing the connection relationship between the filter unit, rectifier unit, and heater provided in some embodiments of this application.

[0080] In some examples, the refrigeration equipment 200 control panel, for instance, may be located within a containment cavity enclosed by the cabinet and isolated from the storage compartment.

[0081] like Figure 7 As shown, the control board may include a circuit board (not shown) and a rectifier unit 230. The circuit board is electrically connected to the power supply, and the rectifier unit 230 is mounted on the circuit board. The rectifier unit 230 is used to convert the alternating current (AC) output from the power supply into direct current (DC).

[0082] The circuit board may include at least one of a printed circuit board (PCB), a flexible printed circuit (FPC), and a flexible printed circuit board (FPCB). The embodiments of this application do not further limit the specific form of the circuit board.

[0083] like Figure 7 As shown, the rectifier unit 230 can be electrically connected between the live wire L and the neutral wire N. The rectifier unit 230 can include multiple electrically connected diodes to convert the AC power output from the power supply into DC power.

[0084] like Figure 7 As shown, the refrigeration device 200 may further include a filter unit 260, which is mounted on a circuit board and electrically connected between the power supply and the rectifier unit 230. The filter unit 260 may include multiple filter capacitors and multiple filter inductors electrically connected to each other, serving a filtering function to reduce the impact of noise in the AC power supply on the rectifier unit 230.

[0085] For example, the filter unit 260 may include a first capacitor CX1, a second capacitor CX2, a third capacitor CY1, and a fourth capacitor CY2, which can suppress common-mode interference and differential-mode interference in the alternating current.

[0086] Understandably, the rectifier unit 230 and the filter unit 260 can also be, in addition to... Figure 7 Other than the circuit structures shown in the diagram, the embodiments of this application do not further limit the circuit structures of the rectifier unit 230 and the filter unit 260.

[0087] In some examples, such as Figure 7 As shown, the conductive rod 140 is electrically connected to the output terminal of the rectifier unit 230. That is, the conductive rod 140 is electrically connected to the power supply through the rectifier unit 230. In this way, the DC power output by the rectifier unit 230 can be transmitted to the heating wire 130 through the conductive rod 140, thereby enabling the heater 100 to generate heat.

[0088] Refer again Figure 4 In some examples, the conductive rod 140 includes a first conductive rod 141 and a second conductive rod 142.

[0089] At least a portion of the first conductive rod 141 is located inside the metal tube 110 and is electrically connected to the heating wire 130. The first conductive rod 141 is used to electrically connect to the positive terminal of the rectifier unit 230. At least a portion of the second conductive rod 142 is located inside the metal tube 110 and is electrically connected to the heating wire 130. The second conductive rod 142 is used to electrically connect to the negative terminal of the rectifier unit 230.

[0090] Understandably, the positive terminal of the rectifier unit 230 is the positive terminal of DC power, and the negative terminal of the rectifier unit 230 is the negative terminal of DC power.

[0091] A portion of the first conductive rod 141 may be located inside the metal tube 110 and electrically connected to one end of the heating wire 130. Another portion of the first conductive rod 141 may extend outside the metal tube 110 through one opening of the metal tube 110 and be electrically connected to the positive terminal of the rectifier unit 230.

[0092] A portion of the second conductive rod 142 may be located inside the metal tube 110 and electrically connected to the other end of the heating wire 130. The other end of the second conductive rod 142 may extend outside the metal tube 110 through another opening of the metal tube 110 and be electrically connected to the negative terminal of the rectifier unit 230.

[0093] In this way, after the current flows out from the positive terminal of the rectifier unit 230, it can flow into the heating wire 130 through the first conductive rod 141, so that the heating wire 130 can generate heat, and then flow back to the negative terminal of the rectifier unit 230 through the second conductive rod 142.

[0094] Continue to refer to Figure 4 In some examples, heater 100 also includes an insulating sleeve 180 that covers the portion of metal tube 110 and conductive rod 140 outside of metal tube 110.

[0095] For example, the insulating protective sleeve 180 may include a first insulating protective sleeve 181 and a second insulating protective sleeve 182.

[0096] The first insulating protective sleeve 181 can be fitted onto the portion of the metal tube 110 near one opening and the portion of the first conductive rod 141 outside the metal tube 110 (that is, the second part of the first conductive rod 141). The second insulating protective sleeve 182 can be fitted onto the portion of the metal tube 110 near the other opening and the portion of the second conductive rod 142 outside the metal tube 110 (that is, the second part of the second conductive rod 142).

[0097] Understandably, the insulating protective sleeve 180 serves both insulating and protective functions. By employing the above-described arrangement, on the one hand, the portion of the metal tube 110 near the opening and the portion of the conductive rod 140 outside the metal tube 110 are electrically isolated, reducing the risk of a short circuit between them. On the other hand, it protects both the portion of the metal tube 110 near the opening and the portion of the conductive rod 140 outside the metal tube 110.

[0098] For example, the material of the insulating protective sleeve 180 may include at least one of insulating materials such as rubber and epoxy resin. The embodiments of this application do not further limit the material of the insulating protective sleeve 180.

[0099] Understandably, heater 100 does not need to defrost evaporator 223 for a long time. Under normal circumstances, heater 100 only needs to work for about 0.5 hours a day.

[0100] In some examples, such as Figure 7 As shown, the refrigeration device 200 also includes a relay 240, which is connected between the first conductive rod 141 and the positive terminal of the rectifier unit 230, and is used to control the first conductive rod 141 and the positive terminal of the rectifier unit 230 to be turned on or off.

[0101] Understandably, when defrosting of the evaporator 223 is required, the relay 240 can be turned on, allowing the rectifier unit 230 to supply power to the heating wire 130 through the first conductive rod 141. When defrosting of the evaporator 223 is not required, the relay 240 can be turned off, causing the heater 100 to stop working, thereby reducing the impact of the heater 100 on the evaporator 223.

[0102] For example, relay 240 can be turned on or off based on control commands from the controller of the refrigeration equipment 200, or relay 240 can be turned on or off based on user operations. The embodiments of this application do not further limit this.

[0103] Understandably, surges can occur in the power grid when struck by lightning or other factors. Surge voltages are typically very high, potentially reaching several kilovolts or even higher. When a surge is conducted to heater 100, the surge voltage can potentially break down the insulation, causing a short circuit between the metal tube 110 and the conductive rod 140 or heating wire 130, or even sparking, thereby causing a fire and affecting the safety and reliability of heater 100.

[0104] In some possible implementations, a varistor can be placed on the circuit board. When the voltage across the varistor is low, the resistance of the varistor is high; when the voltage across the varistor is high, the resistance of the varistor is low.

[0105] For example, varistors can be placed between the live wire L and the neutral wire N, between the live wire L and the ground wire, and between the neutral wire N and the ground wire on the circuit board.

[0106] Taking the varistor between the live wire L and the neutral wire N as an example, when there is no surge, the voltage between the live wire L and the neutral wire N on the circuit board is small, and the resistance value of the varistor is large, which can electrically isolate the live wire L and the neutral wire N. When a surge is conducted to the live wire L and the neutral wire N, the resistance value of the varistor is small, which can conduct the live wire L and the neutral wire N, so that the surge will not be transmitted to the rectifier unit 230 and the heater 100, reducing the risk of a short circuit between the metal tube 110 and the conductive rod 140 or the heating wire 130 caused by the surge voltage.

[0107] However, when the varistor is connected between the live wire (L) and the ground wire, the leakage current on the varistor will be relatively large, requiring a discharge tube to suppress the leakage current, which increases the complexity of the circuit structure. Furthermore, placing varistors between the live wire (L) and the neutral wire (N), between the live wire (L) and the ground wire, and between the neutral wire (N) and the ground wire will increase the number of components on the circuit board, hindering cost reduction and miniaturization of the circuit board.

[0108] Based on this, in the embodiments of this application, the metal pipe 110 and the grounding terminal of the refrigeration device 200 are electrically connected. For example, the refrigeration device 200 may include a housing, which may be electrically connected to the grounding terminal, and the metal pipe 110 may be electrically connected to the housing, so that the metal pipe 110 can be grounded. Alternatively, the metal pipe 110 may also be directly electrically connected to the grounding terminal.

[0109] In some examples, such as Figure 6 As shown, the heater 100 includes a varistor 150, which is sleeved on the portion of the conductive rod 140 located inside the metal tube 110 and is in contact with the inner wall 1101 of the metal tube 110.

[0110] For example, the varistor 150 can be a metal oxide varistor (MOV). The varistor 150 can be a ring structure, so that the varistor 150 can be sleeved on the part of the conductive rod 140 located inside the metal tube 110, and can contact the inner wall 1101 of the metal tube 110.

[0111] Varistor 150 is configured as follows: When the voltage between the conductive rod 140 and the metal tube 110 is less than a set voltage threshold, the conductive rod 140 and the metal tube 110 are electrically isolated.

[0112] When the voltage between the conductive rod 140 and the metal tube 110 is greater than or equal to a set voltage threshold, the conductive rod 140 and the metal tube 110 are electrically connected.

[0113] Understandably, when a surge exists in the circuit, the surge will be conducted to the heater 100 via the conductive rod 140. When the voltage between the conductive rod 140 and the metal tube 110 is less than a set voltage threshold, it can be determined that no surge enters the heater 100. At this time, the resistance value of the varistor 150 is large, which can electrically isolate the conductive rod 140 and the metal tube 110, and the heater 100 can work normally.

[0114] When the voltage between the conductive rod 140 and the metal tube 110 is greater than or equal to a set voltage threshold, it can be determined that the surge is conducted to the heater 100. At this time, the resistance of the varistor 150 is small enough to electrically connect the conductive rod 140 and the metal tube 110. Understandably, the metal tube 110 is electrically connected to the grounding terminal, so that the conductive rod 140 can be grounded through the metal tube 110, thereby enabling the surge to be transmitted to the grounding terminal.

[0115] In other words, a varistor 150 is fitted inside the conductive rod 140 within the metal tube 110 and contacts the inner wall 1101 of the metal tube 110, so that the varistor 150 can electrically connect the conductive rod 140 and the metal tube 110 when a surge is conducted to the heater 100, and the metal tube 110 is electrically connected to the grounding terminal, thereby transmitting the surge to the grounding terminal.

[0116] This reduces the risk of surge voltage breaking down the insulation, thereby reducing the risk of short circuits between the metal tube 110 and the conductive rod 140 or the heating wire 130, and improving the safety and reliability of the heater 100.

[0117] Compared to setting the varistor on the circuit board, the embodiments of this application enclose the varistor 150 in the portion of the conductive rod 140 located inside the metal tube 110, so that the varistor 150 does not need to occupy additional space on the circuit board, reducing the number of components on the circuit board and facilitating the miniaturization of the circuit board.

[0118] Understandably, the embodiments of this application do not further limit the value of the set voltage threshold.

[0119] In some examples, the varistor sleeve 150 is disposed on at least one of the first conductive rod 141 and the second conductive rod 142.

[0120] Understandably, there can be two varistor 150s. One varistor 150 is sleeved on the part of the first conductive rod 141 located inside the metal tube 110 and in contact with the inner wall 1101 of the metal tube 110. The other varistor 150 is sleeved on the part of the second conductive rod 142 located inside the metal tube and in contact with the inner wall 1101 of the metal tube 110.

[0121] When the surge current flows along the direction from the first conductive rod 141 to the second conductive rod 142, the varistor 150 sleeved on the first conductive rod 141 can electrically connect the first conductive rod 141 and the metal tube 110, so that the first conductive rod 141 can be grounded through the metal tube 110, thereby guiding the surge to the grounding terminal.

[0122] Conversely, when the surge current flows along the direction from the second conductive rod 142 to the first conductive rod 141, the varistor 150 sleeved on the second conductive rod 142 can electrically connect the second conductive rod 142 and the metal tube 110, so that the second conductive rod 142 can be grounded through the metal tube 110, thereby guiding the surge to the grounding terminal.

[0123] When there are two varistors 150, one varistor 150 is sleeved on the first conductive rod 141 and the other varistor 150 is sleeved on the second conductive rod 142, so that the first conductive rod 141 and the second conductive rod 142 can be electrically connected to the metal tube 110 through the varistor 150 respectively. This allows surges in different directions to be guided to the grounding terminal, reducing the risk of surge voltage breaking down the insulation and improving the safety and reliability of the heater 100.

[0124] Alternatively, the number of varistor 150 can be one. In this case, the varistor 150 can be sleeved on the first conductive rod 141 or the second conductive rod 142 to simplify the structure of the heater 100 and reduce the cost of the heater 100.

[0125] The varistor sleeve 150 is set on at least one of the first conductive rod 141 and the second conductive rod 142, which improves the flexibility of the varistor 150 and meets different usage requirements.

[0126] In some examples, there is one varistor 150, which is mounted on the second conductive rod 142.

[0127] As described above, the first conductive rod 141 is electrically connected to the positive terminal of the rectifier unit 230 via the relay 240. The relay 240 controls the connection or disconnection between the first conductive rod 141 and the rectifier unit 230. When the relay 240 is on, the heater 100 operates normally; when the relay 240 is off, the heater 100 stops operating.

[0128] Understandably, when relay 240 is disconnected, surge current cannot enter heater 100 via first conductive rod 141. Since heater 100 does not need to continuously defrost evaporator 223, heater 100 only needs to operate for about 0.5 hours per day, making the probability of surge current entering heater 100 via first conductive rod 141 relatively small.

[0129] In this way, the number of varistor 150 can be set to one and sleeved on the second conductive rod 142, which reduces the risk of surge current entering the heater 100 through the second conductive rod 142, improves the safety and reliability of the heater 100, simplifies the structure of the heater 100, and reduces the cost of the heater 100.

[0130] Figure 8 for Figure 3 A schematic diagram of the cross-sectional structure along the A2-A2 direction. In some examples, such as... Figure 8 As shown, the varistor 150 has a tubular structure, and the tube wall 151 of the varistor 150 includes a first conductive layer 1511 and a second conductive layer 1512 of varistor material 1513.

[0131] A first conductive layer 1511 is sleeved on the portion of the conductive rod 140 located inside the metal tube 110. A second conductive layer 1512 surrounds the first conductive layer 1511, and the second conductive layer 1512 is in contact with the inner wall 1101 of the metal tube 110. A pressure-sensitive material 1513 is filled between the first conductive layer 1511 and the second conductive layer 1512.

[0132] This configuration allows the varistor 150 to have a ring-shaped structure. Understandably, the first conductive layer 1511 and the second conductive layer 1512 serve to conduct electricity and protect the varistor material 1513. The varistor material 1513 may include a semiconductor varistor material, and its resistance changes with the applied voltage. This allows the resistance of the varistor 150 to change with the voltage between the metal tube 110 and the conductive rod 140, thereby electrically connecting the conductive rod 140 and the metal tube 110 when a surge is conducted to the heater 100.

[0133] For example, the pressure-sensitive material 1513 may include zinc oxide. Alternatively, the pressure-sensitive material 1513 may also include other semiconductor pressure-sensitive materials, which are not further limited in the embodiments of this application.

[0134] Figure 9 The diagram shows the structure of a varistor provided in some embodiments of this application. Figure 10 for Figure 9 A schematic diagram of the cross-sectional structure along the A3-A3 direction.

[0135] In some examples, combined Figure 8 , Figure 9 and Figure 10 The first conductive layer 1511 includes a first body portion 1511a and a first protrusion portion 1511b.

[0136] The first body portion 1511a is sleeved on the portion of the conductive rod 140 located inside the metal tube 110, and a first gap P1 is formed between the first body portion 1511a and the outer surface of the conductive rod 140. The first protrusion 1511b is connected to the first body portion 1511a and located within the first gap P1, and the first protrusion 1511b is in contact with the conductive rod 140.

[0137] Understandably, the first protrusion 1511b protrudes relative to the first body portion 1511a in a direction away from the second conductive layer 1512, so that the first protrusion 1511b can be located within the first gap P1.

[0138] The first protrusion 1511b can be a circular protrusion, an annular protrusion, a frustum-shaped protrusion, or other regular and irregular shapes. The embodiments of this application do not further limit the shape of the first protrusion 1511b.

[0139] The number of first protrusions 1511b can be multiple, with multiple first protrusions 1511b arranged at intervals and connected to the first body portion 1511a respectively. The embodiments of this application do not further limit the number or arrangement position of the first protrusions 1511b.

[0140] For example, a first protrusion 1511b can be formed on the first body portion 1511a by stamping, so that the first protrusion 1511b can protrude relative to the first body portion 1511a. The first protrusion 1511b can abut against the conductive rod 140 to improve the reliability of the electrical contact between the first protrusion 1511b and the conductive rod 140.

[0141] The first conductive layer 1511 includes a first body portion 1511a and a first protrusion portion 1511b, which can reduce the friction between the first conductive layer 1511 and the outer surface of the conductive rod 140 during the process of putting the varistor 150 on the conductive rod 140, and improve the convenience of putting the varistor 150 on the conductive rod 140.

[0142] Continue to refer to Figure 8 , Figure 9 and Figure 10 In some examples, the second conductive layer 1512 includes a second body portion 1512a and a second protrusion 1512b.

[0143] The second body portion 1512a surrounds the first body portion 1511a, and a second gap P2 is formed between the second body portion 1512a and the inner wall 1101 of the metal tube 110. The second protrusion 1512b is connected to the second body portion 1512a and is located within the second gap P2, and the second protrusion 1512b is in contact with the inner wall 1101 of the metal tube 110.

[0144] Understandably, the second protrusion 1512b protrudes relative to the second body portion 1512a in a direction away from the first conductive layer 1511, so that the second protrusion 1512b can be located within the second gap P2.

[0145] The second protrusion 1512b can be a circular protrusion, an annular protrusion, a frustum-shaped protrusion, or other regular and irregular shapes. The embodiments of this application do not further limit the shape of the second protrusion 1512b.

[0146] The number of second protrusions 1512b can be multiple, and the multiple second protrusions 1512b are arranged at intervals and connected to the second body portion 1512a respectively. The embodiments of this application do not further limit the number and arrangement position of the second protrusions 1512b.

[0147] Understandably, the shape and number of the first protrusion 1511b may be the same as or different from the shape and number of the second protrusion 1511b.

[0148] For example, a second protrusion 1512b can be formed on the second body portion 1512a by stamping, so that the second protrusion 1512b can protrude relative to the second body portion 1512a. The second protrusion 1512b can abut against the inner wall 1101 of the metal tube 110 to improve the reliability of the electrical contact between the second protrusion 1512b and the metal tube 110.

[0149] For example, the varistor 150 can be interference-fitted with the metal tube 110 and the conductive rod 140, so that the first protrusion 1511b can abut against the conductive rod 140 and the second protrusion 1512b can abut against the inner wall 1101 of the metal tube 110.

[0150] The second conductive layer 1512 includes a second body portion 1512a and a second protrusion portion 1512b, which can reduce the friction between the second conductive layer 1512 and the inner wall 1101 of the metal tube 110 during the process of placing the varistor 150 inside the metal tube 110, thereby improving the convenience of placing the varistor 150 inside the metal tube 110.

[0151] In some examples, when the first conductive layer 1511 includes a first body portion 1511a and a first protrusion 1511b, the heater 100 also includes a first filling portion (not shown in the figure), which fills the first gap P1.

[0152] By setting the first filling part to fill the first gap P1, the risk of the first body part 1511a deforming toward the first gap P1 due to external force can be reduced, which is beneficial to improving the mechanical strength of the heater 100.

[0153] For example, the first filler portion can be an insulating material; for instance, the material of the first filler portion may include epoxy resin. Alternatively, the first filler portion can also be a conductive material to improve the conductivity between the varistor 150 and the conductive rod 140.

[0154] When the second conductive layer 1512 includes a second body portion 1512a and a second protrusion 1512b, the heater 100 also includes a second filling portion (not shown in the figure), which fills the second gap P2.

[0155] By providing a second filling portion to fill the second gap P2, the risk of the second body portion 1512a deforming toward the second gap P2 due to external force can be reduced, and the risk of the metal tube 110 denting toward the second gap P2 can be reduced, which is beneficial to improving the mechanical strength of the heater 100.

[0156] For example, the second filler portion can be an insulating material; for instance, the material of the second filler portion may include epoxy resin. Alternatively, the second filler portion can also be a conductive material to improve the conductivity between the varistor 150 and the metal tube 110.

[0157] Refer again Figure 6 In some examples, heater 100 also includes a first sealing portion 171 and a second sealing portion 172.

[0158] The first sealing part 171 is sleeved on the part of the conductive rod 140 located inside the metal tube 110 and is in contact with the inner wall 1101 of the metal tube 110. Along the extension direction of the metal tube 110, the first sealing part 171 is located between the varistor 150 and the insulating part. The first sealing part 171 is an insulating component.

[0159] Understandably, the first sealing part 171 can isolate the insulating part and the varistor 150, thus providing a seal and reducing the risk of magnesium oxide powder in the insulating part leaking from the metal tube 110. Furthermore, the first sealing part 171 is an insulating component, providing electrical isolation and reducing the risk of a short circuit between the conductive rod 140 and the metal tube 110.

[0160] The second sealing part 172 is sleeved on the part of the conductive rod 140 located inside the metal tube 110 and contacts the inner wall 1101 of the metal tube 110. Along the extension direction of the metal tube 110, the second sealing part 172 is located on the side of the varistor 150 away from the first sealing part 171, and the second sealing part 172 seals the opening of the metal tube 110. The second sealing part 172 is an insulating component.

[0161] Understandably, the second sealing part 172 can seal the opening of the metal tube 110, reducing the risk of the varistor 150, the insulating part, and the conductive rod 140 falling out of the metal tube 110. Furthermore, the second sealing part 172 is an insulating component, which can play a role in electrical isolation, reducing the risk of short circuit between the conductive rod 140 and the metal tube 110.

[0162] For example, the material of the sealing portion (including the first sealing portion 171 and the second sealing portion 172) may include epoxy resin, or the sealing portion may also include other insulating materials such as rubber. The embodiments of this application do not further limit the material of the sealing portion. It is understood that the materials of the first sealing portion 171 and the second sealing portion 172 may be the same or different.

[0163] In the process of manufacturing the heater 100, the heating wire 130 and the conductive rod 140 can be electrically connected first, and the heating wire 130 and the first part of the conductive rod can be placed inside the metal tube 110. Then, magnesium oxide powder can be filled into the metal tube 110, allowing the heating wire 130 and a portion of the first part of the conductive rod to be embedded within the insulating portion. Understandably, the magnesium oxide powder has good fluidity within the metal tube 110 and can fill the gaps formed between the heating wire 130, the conductive rod 140, and the inner wall 1101 of the metal tube 110.

[0164] After magnesium oxide powder is filled into the metal tube 110, a first sealing portion 171 can be formed, such that the first sealing portion 171 can be fitted onto the portion of the conductive rod 140 located inside the metal tube 110 and contact the inner wall 1101 of the metal tube 110. Then, a varistor 150 can be fitted onto the portion of the conductive rod 140 located inside the metal tube 110.

[0165] After the varistor 150 is fitted onto the portion of the conductive rod 140 located inside the metal tube 110, a second sealing portion 172 can be formed, such that the second sealing portion 172 can be fitted onto the portion of the conductive rod 140 located inside the metal tube 110 and contact the inner wall 1101 of the metal tube 110, and that the second sealing portion 172 can seal the opening of the metal tube 110.

[0166] After the second sealing part 172 is formed, the insulating protective sleeve 180 can be fitted onto the part of the metal tube 110 near the tube opening and the part of the conductive rod 140 outside the metal tube 110 (i.e. the second part of the conductive rod) to provide protection and insulation.

[0167] For example, the metal tube 110 can be bent after or before the insulating protective sleeve 180 is applied, so that the metal tube 110 can be bent and extended according to a set shape.

[0168] For example, such as Figure 3 and Figure 4 As shown, the heater 100 may also include a reinforcing member 190, which is located on the outer surface of the metal tube 110 and connects adjacent sections of the metal tube 110 to improve the mechanical strength of the heater 100.

[0169] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the embodiments of this application, and are not intended to limit them; although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the foregoing embodiments, or make equivalent substitutions for some or as many of the technical features as possible; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application.

Claims

1. A heater, characterized in that, The heater, used for defrosting the evaporator of a refrigeration unit, includes: A metal tube, which is electrically connected to the grounding terminal of the refrigeration equipment; The insulating part is filled inside the metal tube; The heating wire is embedded within the insulating portion; A conductive rod, at least a portion of which is located inside the metal tube and electrically connected to the heating wire, the conductive rod being used for electrical connection to a power source; and, A varistor is fitted onto the portion of the conductive rod located inside the metal tube and is in contact with the inner wall of the metal tube; The varistor is configured as follows: When the voltage between the conductive rod and the metal tube is less than a set voltage threshold, the conductive rod and the metal tube are electrically isolated. When the voltage between the conductive rod and the metal tube is greater than or equal to a set voltage threshold, the conductive rod and the metal tube are electrically connected.

2. The heater according to claim 1, characterized in that, The varistor has a tubular structure, and the tube wall of the varistor includes: The first conductive layer is sleeved on the portion of the conductive rod located inside the metal tube; A second conductive layer surrounds the first conductive layer, and the second conductive layer is in contact with the inner wall of the metal tube; A pressure-sensitive material is filled between the first conductive layer and the second conductive layer.

3. The heater according to claim 2, characterized in that, The first conductive layer includes: A first body portion is sleeved on the portion of the conductive rod located inside the metal tube, and a first gap exists between the first body portion and the outer surface of the conductive rod; A first protrusion is connected to the first body portion and located within the first gap, the first protrusion being in contact with the outer surface of the conductive rod; and / or The second conductive layer includes: The second body portion surrounds the first body portion, and a second gap exists between the second body portion and the inner wall of the metal tube; The second protrusion is connected to the second body portion and located within the second gap, and the second protrusion is in contact with the inner wall of the metal tube.

4. The heater according to claim 3, characterized in that, When the first conductive layer includes the first body portion and the first protrusion portion, the heater further includes: The first filling part fills the first gap; When the second conductive layer includes the second body portion and the second protrusion portion, the heater further includes: The second filling portion fills the second gap.

5. The heater according to claim 1, characterized in that, The conductive rod is electrically connected to the power supply via the rectifier unit of the cooling device. The rectifier unit is used to convert the alternating current output by the power supply into direct current. The conductive rod includes: A first conductive rod, at least a portion of which is located inside the metal tube and electrically connected to the heating wire, is used to electrically connect to the positive terminal of the rectifier unit. A second conductive rod, at least a portion of which is located inside the metal tube and electrically connected to the heating wire, is used to electrically connect to the negative terminal of the rectifier unit; The varistor is sleeved on at least one of the first conductive rod and the second conductive rod.

6. The heater according to claim 5, characterized in that, The refrigeration device also includes a relay, which is connected between the first conductive rod and the positive terminal of the rectifier unit, and is used to control the first conductive rod and the positive terminal of the rectifier unit to be connected or disconnected. The number of varistors is one, and it is sleeved on the second conductive rod.

7. The heater according to any one of claims 1 to 6, characterized in that, Also includes: The first sealing part is sleeved on the portion of the conductive rod located inside the metal tube and in contact with the inner wall of the metal tube. Along the extension direction of the metal tube, the first sealing part is located between the varistor and the insulating part, and the first sealing part is an insulating component. The second sealing part is sleeved on the portion of the conductive rod located inside the metal tube and in contact with the inner wall of the metal tube. Along the extension direction of the metal tube, the second sealing part is located on the side of the varistor away from the first sealing part, and the second sealing part seals the opening of the metal tube. The second sealing part is an insulating component.

8. The heater according to any one of claims 1 to 6, characterized in that, The insulating material includes magnesium oxide.

9. The heater according to any one of claims 1 to 6, characterized in that, A portion of the conductive rod is located inside the metal tube, and another portion of the conductive rod extends outside the metal tube through the opening of the metal tube; The heater also includes: An insulating protective sleeve is fitted over the portion of the metal tube and the conductive rod located outside the metal tube.

10. A refrigeration device, characterized in that, include: The container encloses a storage chamber and an evaporation chamber, and the storage chamber and the evaporation chamber are connected. A refrigeration system, comprising a compressor, a condenser, and an evaporator connected in sequence by pipes, wherein the evaporator is disposed in the evaporation chamber and is used to provide cooling capacity to the storage chamber; Control panel, including: The circuit board is electrically connected to the power supply. A rectifier unit is disposed on the circuit board, and the rectifier unit is used to convert the AC power output by the power supply into DC power. The heater as described in any one of claims 1 to 9, wherein the heater is disposed in the evaporation chamber, the conductive rod of the heater is electrically connected to the output terminal of the rectifier unit, and the heater is used for defrosting the evaporator.

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