Thick film heater, heater and heating equipment

Abstract

The invention discloses a thick film heater, a heater and heating equipment, and belongs to the technical field of heaters. The thick film heater comprises a heat conductor (100) which is columnar and is provided with a through heating channel (300); the heating layer (200) is printed on the outer surface of the heat conductor (100) in the axial direction, at least part of the heating layer (200) is discontinuous in the circumferential direction so as to form a spacer region (400), and when the heater operates in a heating mode, the spacer region (400) is arranged upwards.

Description

Thick film heaters, heaters and heating equipment Technical Field

[0001] The present application relates to the technical field of heaters, and in particular to a thick film heater, a heater and a heating device. Background Art

[0002] The heating layer of a thick film heater is usually covered on the surface of the heating channel. When it is used, if the medium in the heating channel is insufficient, there will be a hollow part in the heating channel, and bubbles are likely to accumulate in the hollow part, causing local dry burning and damaging the device.

[0003] Summary of the Invention

[0004] The present application aims to solve at least one of the technical problems existing in the prior art. To this end, the present application provides a thick film heater, a heater, and a heating device. When the thick film heater is in use, the uncovered portion has a non-heating area, thereby avoiding dry burning and overheating.

[0005] In the first aspect, the present application provides a thick film heater, which includes: a heat conductor, which is cylindrical and has a through heating channel; a heating layer, which is axially arranged on the outer surface of the heat conductor, and at least part of the section is discontinuous in the circumferential direction to form a spacing area. When the heater is heating, the spacing area is arranged upward.

[0006] According to the thick film heater of the present application, the heating layer does not completely cover the surface of the heater, and the area not covered by the heating layer is arranged to face upward, so that when the thick film heater is in use, the part facing the upper device does not generate heat. When the medium is not sufficient to completely cover the thick film heater, there is a non-heating area in the uncovered part, thereby avoiding dry burning and overheating.

[0007] According to one embodiment of the present application, the spacing areas are evenly arranged in the axial direction, and the entire heating layer is discontinuous in the circumferential direction.

[0008] According to one embodiment of the present application, the area of ​​the spacer region accounts for 5% to 15% of the outer surface area of ​​the heat conductor.

[0009] According to one embodiment of the present application, the thick film heater further includes: a conveying shaft disposed in the heat conductor, wherein the conveying shaft is formed with spiral blades along the axial direction, and the spiral blades are used to cooperate with the inner wall of the heating channel to form a spiral channel.

[0010] According to one embodiment of the present application, the spiral pitch at both ends of the spiral sheet is greater than the spiral pitch in the middle section.

[0011] According to one embodiment of the present application, the ratio of the spiral pitch of the middle section of the spiral sheet to the axial length of the heating layer is 1:3 to 1:8.

[0012] According to one embodiment of the present application, the heating layer forms a heating circuit, and the thick film heater also includes: a first thermostat, which is arranged on the control loop of the heating circuit, and is disconnected when the temperature of the heating circuit is greater than or equal to a first temperature threshold, and is restored when the temperature of the heating circuit is less than the first temperature threshold; a second thermostat, which is arranged on the control loop of the heating circuit and is connected in series with the first thermostat, and is disconnected when the temperature of the heating circuit is greater than or equal to the second temperature threshold.

[0013] According to one embodiment of the present application, the thick film heater also includes: a first temperature sensor for detecting a first temperature of the fluid flowing into the heater; a second temperature sensor for detecting a second temperature of the fluid flowing out of the heater; and a control unit respectively connected to the first temperature sensor, the second temperature sensor and the heating circuit, for controlling the heating circuit according to the first temperature and the second temperature.

[0014] In the second aspect, the present application also provides a heater, which includes: a heat conductor, which is columnar and has a through heating channel; a heating layer, which is axially arranged on the outer surface of the heat conductor, and the heating layer includes multiple heating areas, each of which has a different heating amount. When the heater is in heating operation, the heating area with the smallest heat amount in each of the heating areas is arranged upward.

[0015] According to the heater of the present application, the heating layer is unevenly arranged on the outer surface of the heat conductor to form a plurality of heating areas with different heat amounts, and the heating area with the smallest heat amount is set upward, so that when the heater is in use, the heat amount of the part facing the upper equipment is lower. When the medium is not sufficient to completely cover the heater, the heat amount of the uncovered part is lower, thereby avoiding dry burning and overheating.

[0016] According to one embodiment of the present application, the multiple heating areas include a first heating area and a second heating area, the heat generated by the first heating area is less than the heat generated by the second heating area, and the first heating areas are evenly arranged along the axial direction.

[0017] According to one embodiment of the present application, the area of ​​the first heating region accounts for 5% to 15% of the area of ​​the heating layer.

[0018] According to one embodiment of the present application, the heater further includes: a conveying shaft disposed in the heat conductor, wherein the conveying shaft is formed with spiral blades along the axial direction, and the spiral blades are used to cooperate with the inner wall of the heating channel to form a spiral channel.

[0019] According to one embodiment of the present application, the spiral pitch at both ends of the spiral sheet is greater than the spiral pitch in the middle section.

[0020] According to one embodiment of the present application, the ratio of the spiral pitch of the middle section of the spiral sheet to the axial length of the heating layer is 1:3 to 1:8.

[0021] According to one embodiment of the present application, the heating layer forms a heating circuit, and the heater also includes: a first thermostat, which is arranged on the control loop of the heating circuit, and is disconnected when the temperature of the heating circuit is greater than or equal to a first temperature threshold, and is restored when the temperature of the heating circuit is less than the first temperature threshold; a second thermostat, which is arranged on the control loop of the heating circuit and is connected in series with the first thermostat, and is disconnected when the temperature of the heating circuit is greater than or equal to the second temperature threshold.

[0022] According to one embodiment of the present application, the heater also includes: a first temperature sensor for detecting a first temperature of the fluid flowing into the heater; a second temperature sensor for detecting a second temperature of the fluid flowing out of the heater; and a control unit respectively connected to the first temperature sensor, the second temperature sensor and the heating circuit, for controlling the heating circuit according to the first temperature and the second temperature.

[0023] In a third aspect, the present application provides a heating device, comprising the thick film heater according to any one of the aforementioned embodiments or the heater according to any one of the aforementioned embodiments.

[0024] According to the heating device of the present application, the upward portion of the heater does not generate heat or generates a low amount of heat. When the medium is insufficient to completely cover the heater, the uncovered portion does not generate heat or generates a low amount of heat, thereby avoiding dry burning and overheating.

[0025] In a fourth aspect, the present application provides a heating device, which includes: a water tank; a main unit connected to the water tank and forming a circulating water circuit, the main unit including a thick film heater according to any one of the aforementioned embodiments or a heater according to any one of the aforementioned embodiments, the thick film heater or the heater being arranged on the circulating water circuit for heating the water flow in the circulating water circuit.

[0026] According to the heating device of the present application, the upward portion of the heater does not generate heat or generates a low amount of heat. When the medium is insufficient to completely cover the heater, the uncovered portion does not generate heat or generates a low amount of heat, thereby avoiding dry burning and overheating.

[0027] According to one embodiment of the present application, an angle between the arrangement direction of the thick film heater or the heater and the vertical direction is greater than 0 degree. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] The above and / or additional aspects and advantages of the present application will become apparent and easily understood from the description of the embodiments in conjunction with the following drawings, in which:

[0029] FIG1 is a schematic diagram of a structure of a heater provided in an embodiment of the present application;

[0030] FIG2 is a schematic structural diagram of a conveying shaft provided in an embodiment of the present application;

[0031] FIG3 is one of the exploded views of the heater provided in an embodiment of the present application;

[0032] FIG4 is a schematic diagram of a structure of a heater provided in an embodiment of the present application;

[0033] FIG5 is a second exploded view of the heater provided in an embodiment of the present application.

[0034] Reference numerals:

[0035] Thermal conductor 100;

[0036] Heating layer 200, first heating area 210, second heating area 220;

[0037] Heating channel 300;

[0038] spacer 400;

[0039] Reserved segment 500;

[0040] Conveying shaft 600, spiral piece 610, sealing portion 620, through hole 621;

[0041] A first thermostat 710, a second thermostat 720;

[0042] A first temperature sensor 810, a second temperature sensor 820;

[0043] Protective shell 900, mounting hole 910;

[0044] Connecting piece 1000, connecting hole 1001;

[0045] Input mechanism 1100, input port 1101;

[0046] Output mechanism 1200 output port 1201;

[0047] Sealing gasket 1300. DETAILED DESCRIPTION

[0048] The following describes in detail embodiments of the present application. Examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present application and are not to be construed as limiting the present application.

[0049] Referring to Figure 1 , one embodiment of the present application provides a thick film heater. The thick film heater includes a heat conductor 100 and a heating layer 200 . The heat conductor 100 is cylindrical and has a through-going heating channel 300 . The heating layer 200 is printed axially on the outer surface of the heat conductor 100 , with at least some sections being discontinuous circumferentially, forming a spacer 400 . When the thick film heater is operating, the spacer 400 is positioned upward.

[0050] In this embodiment, the heat conductor 100 can be made of a metal material (such as copper) or a heat-conducting material such as stainless steel. The heating channel 300 is used to transport the medium. When the medium passes through the heating channel 300, the heat conductor 100 transfers the heat generated by the heating layer 200 to the medium, thereby heating the medium. The medium can be water or oil, etc., and this embodiment uses water as an example.

[0051] The heat conductor 100 may be cylindrical, but it may also be in other shapes, such as a square column. This embodiment is described using a cylindrical shape as an example. The heating channel 300 may have the same shape as the heat conductor 100, such as a circular channel, thereby providing a larger flow area within a limited size.

[0052] It is understandable that the heating layer 200 may be a heating circuit formed by screen printing technology, which may be formed by sequentially printing a dielectric layer and a resistor layer.

[0053] In some embodiments, the heat conductor 100 has a predetermined width at both ends, with the circumferential area surrounding it serving as a reserved section 500 for connection to a water system. Thick-film heaters require connection to a water system, such as by installing water inlet and outlet mechanisms at both ends. Therefore, by providing a reserved section 500 for connection to the water system, interference between the water system and the heating layer 200 is avoided.

[0054] It should be noted that the area between the two reserved sections 500 on the heat conductor 100 serves as a printed section for printing the heat conductor 100. The area on the outer surface of the heat conductor 100 not covered by the heat conductor 100 within this printed section is the spacer 400. Because the heat-generating layer 200 is not disposed within the spacer 400, no heat is generated during operation of the thick-film heater. Therefore, even if the inner wall of the heating channel 300 corresponding to the spacer 400 is not covered by a dielectric, dry heating will not occur.

[0055] In some embodiments, the spacer 400 may include multiple independent areas, and the center lines of the spacers 400 are arranged along the same busbar on the outer surface of the heat conductor 100. On this busbar, the heating layer 200 is printed on the heat conductor 100 at intervals, reducing the heat generation while retaining a certain amount of heat generation.

[0056] In this embodiment, the thick film heater can be connected to an external water supply circuit, and the thick film heater can be arranged horizontally or tilted. Water flows into the thick film heater from one side and flows out from the other side. When the water flow rate is sufficient, the water flow fills the entire heating channel 300 in the thick film heater; when the water flow rate is insufficient, the water flow cannot fill the entire heating channel 300 in the thick film heater. At this time, due to the action of gravity, the water in the heating channel 300 covers the lower part, and the upper part forms a hollow part. The smaller the water flow rate, the larger the space of the hollow part, and the correspondingly larger the inner wall area not covered by the water flow, and the more serious the dry burning of the thick film heater.

[0057] It is understood that to prevent dry-burning and related malfunctions, the thick-film heater should be arranged so that the spacer 400 is located at the location most susceptible to dry-burning. Thick-film heaters can be arranged in either an inclined or horizontal configuration. In an inclined configuration, the location most susceptible to dry-burning is the upper surface of the higher end of the heat conductor 100; in a horizontal configuration, the location most susceptible to dry-burning is the upper surface of the entire heat conductor 100.

[0058] When the thick-film heater is tilted, the upward orientation of the spacer 400 means that the spacer 400 is located on the upper surface of the higher end of the heat conductor 100 and is positioned above the thick-film heater. When the thick-film heater is tilted and horizontally arranged, the upward orientation of the spacer 400 means that the spacer 400 is positioned above the thick-film heater. In this way, the spacer 400 is located at the top of the heat conductor 100. When the dielectric is insufficient, the top of the heating channel 300 is not covered by the dielectric. However, since the spacer 400 at the top does not generate heat, the thick-film heater will not dry-heat when the dielectric is insufficient.

[0059] In the thick film heater of the embodiment of the present application, the heating layer 200 does not completely cover the surface of the thick film heater. Furthermore, the area not covered by the heating layer 200 is arranged upward. This ensures that when the thick film heater is in use, the portion facing upward does not generate heat. When the dielectric material is insufficient to completely cover the thick film heater, the uncovered portion provides a non-heating area, thus preventing dry heating and overheating.

[0060] 1 , in some embodiments of the present application, the spacer regions 400 are evenly arranged in the axial direction, and the entire heating layer 200 is discontinuous in the circumferential direction.

[0061] In this embodiment, there is one spacer 400. The entire section of the heating layer 200 refers to the entire printed section. The heating layer 200 is discontinuous in the circumferential direction at each position of the printed section, and the ends of the formed spacer 400 extend to the reserved sections 500 at both ends of the heat conductor 100. When the thick film heater is arranged, it can be arranged horizontally, with the center line of the spacer 400 at the top. When the medium in the heating channel 300 is insufficient, the top of the heating channel 300 is not covered by the medium, but because the spacer 400 does not generate heat, dry burning is avoided.

[0062] According to the thick film heater of the embodiment of the present application, the heating layer 200 is evenly printed along the axial direction of the heat conductor 100 and a blank end is reserved in the circumferential direction to form a uniformly distributed spacing area 400, making the printing of the heating layer 200 simpler.

[0063] In some embodiments of the present application, the area of ​​the spacer 400 accounts for 5% to 15% of the outer surface area of ​​the heat conductor 100 .

[0064] In this embodiment, the outer surface area of ​​the heat conductor 100 may refer to the outer surface area of ​​the heat conductor 100 within the printing section. The larger the area of ​​the spacer 400 is, the smaller the area of ​​the heat generating layer 200 is.

[0065] It is understood that the provision of the spacer 400 will reduce the maximum heating value of the thick film heater. Furthermore, the larger the area of ​​the spacer 400, the lower the maximum heating value of the thick film heater. Therefore, the area of ​​the spacer 400 should not be too large. By setting the area of ​​the spacer 400 to account for 5% to 15% of the outer surface area of ​​the heat conductor 100, the provision of the spacer 400 can be prevented from affecting the heating performance of the thick film heater.

[0066] In some embodiments, the area of ​​the spacer region accounts for 7% of the outer surface area of ​​the heat conductor.

[0067] According to the thick film heater of the embodiment of the present application, by setting the area of ​​the spacer 400 to account for 7% of the outer surface area of ​​the heat conductor 100, the thick film heater is prevented from dry burning while ensuring sufficient heating performance.

[0068] 2 , in some embodiments of the present application, the thick film heater may further include a conveying shaft 600 . The conveying shaft 600 is disposed in the heat conductor 100 and has spiral blades 610 formed along the axial direction thereof. The spiral blades 610 are used to cooperate with the inner wall of the heating channel 300 to form a spiral channel.

[0069] It should be noted that after the delivery shaft 600 is installed in the heat conductor 100, the original heating channel 300 is replaced by a spiral channel. After entering the heat conductor 100, the medium flows along the spiral channel. Compared with a straight heating channel, the spiral channel increases the surface area of ​​the water flow, thereby improving the water heating efficiency without changing the heating power and size of the heating tube.

[0070] It should be noted that to facilitate the insertion and removal of the conveyor shaft 600 into and from the heating channel 300, a certain distance can be provided between the outer diameter of the spiral blade 610 and the inner wall of the heating channel 300. Furthermore, to ensure that the water flows along the spiral channel, this distance should not be too large. In some embodiments, the outer diameter of the spiral blade 610 can be 0.5 to 1.5 mm narrower than the diameter of the heating channel 300.

[0071] In some embodiments, the outer diameter of the spiral blade 610 can be 0.5 mm narrower than the diameter of the heating channel 300, reducing the flow rate of water flowing in a straight line along the axial direction of the thick film heater in the gap between the spiral blade 610 and the inner wall of the heating channel 300, allowing the water to flow in the spiral channel, thereby improving the heating effect.

[0072] In this embodiment, the length L of the spiral piece 610 can be equal to the axial length of the heating layer 200. If the length of the spiral piece 610 is too long, the water flow in the two ends of the spiral channel cannot be heated, but will lead to a decrease in the overall flow rate of the water flow. If the length of the spiral piece 610 is too short, the water flow in the two ends of the heating channel 300 is large and the heating effect is poor. Therefore, when the length of the spiral piece 610 can be equal to the axial length of the heating layer 200, the water flow can be heated most effectively and the flow rate is less affected.

[0073] It is understood that excessive thickness of the spiral blade 610 will reduce the space in the spiral channel, thereby reducing the heating effect of the thick film heater. Therefore, the thickness of the spiral blade 610 can be as thin as possible while ensuring strength. In some embodiments, the thickness of the spiral blade 610 can be 0.8 mm to 3 mm, such as 1.2 mm.

[0074] In some embodiments, the conveying shaft 600 further includes sealing portions 620 at both ends of the spiral blade 610. These sealing portions 620 include through-holes 621, which are identical to the spiral channel. The sealing portions 620 seal the heating channel 300 at both ends of the spiral blade 610, allowing the spiral channel to communicate with the external space through the through-holes 621. The through-holes 621 at both ends can serve as the water inlet or outlet of the spiral channel.

[0075] According to the thick film heater of the embodiment of the present application, the spiral channel is used to transport the medium in the thick film heater, so that the medium is evenly heated, thereby improving the heating efficiency of the thick film heater.

[0076] In some embodiments of the present application, the spiral pitch at both ends of the spiral sheet 610 is greater than the spiral pitch in the middle section.

[0077] Referring to Figure 2 , it should be noted that the spiral pitch at both ends of the spiral piece 610 refers to a first distance L1 between the connecting surface of the through hole 621 and the spiral channel and the opposite spiral piece, and the spiral pitch in the middle section of the spiral piece 610 refers to a second distance L2 between two adjacent spiral pieces. Furthermore, since the spiral piece 610 is continuous, the spiral pitch at both ends of the spiral piece 610 gradually decreases as it approaches the middle section.

[0078] It is understandable that the cross-sectional area of ​​the spiral channel is smaller than the cross-sectional area of ​​the external water channel. Therefore, when the water flows into the spiral channel from the external water channel or flows out from the spiral water channel to the external water channel, the water flow may be poor due to the sudden narrowing of the water channel. Among them, the cross-sectional area of ​​the spiral channel refers to the area of ​​the cross section along the opposite direction of the channel perpendicular to the spiral channel. By making the spiral pitch at both ends of the spiral blade 610 greater than the spiral pitch in the middle section, the water flow space at both ends of the spiral water channel is increased, thereby reducing the sudden change in flow when the water flows into the spiral channel from the external water channel or flows out from the spiral water channel to the external water channel, making the water flow smoother.

[0079] In some embodiments of the present application, the ratio of the spiral pitch of the middle section of the spiral sheet 610 to the axial length of the heating layer 200 is 1:3 to 1:8.

[0080] It should be noted that, given a given length of the spiral blade 610, a greater ratio of the spiral pitch in the middle section of the spiral blade 610 to the axial length of the heating layer indicates a longer spiral channel. However, an excessively long spiral channel may cause water channel blockage. A smaller ratio of the spiral pitch in the middle section of the spiral blade 610 to the axial length of the heating layer indicates a shorter spiral channel. However, an excessively short spiral channel may cause water to flow through the thick film heater too quickly, resulting in lower heating efficiency.

[0081] In some embodiments, the ratio of the spiral pitch of the middle section of the spiral sheet 610 to the axial length of the heating layer can be determined according to the heating power of the heating layer 200. When the heating power of the heating layer 200 is high, a shorter spiral channel can be provided, that is, the ratio of the spiral pitch of the middle section of the spiral sheet 610 to the axial length of the heating layer is low; when the heating power of the heating layer 200 is low, a longer spiral channel can be provided, that is, the ratio of the spiral pitch of the middle section of the spiral sheet 610 to the axial length of the heating layer is large.

[0082] In some embodiments, the ratio of the spiral pitch of the middle section of the spiral 610 to the axial length of the heating layer 200 is 1:7.

[0083] According to the thick film heater of the embodiment of the present application, the length of the spiral channel is moderate, and the water flow is not easily blocked when passing through the spiral channel. At the same time, the water flow can also be fully heated in the spiral channel, thereby improving the heating effect of the thick film heater.

[0084] 3 , in some embodiments of the present application, the heating layer 200 is formed with a heating circuit, and the thick film heater may further include a first thermostat 710 and a second thermostat 720. The first thermostat 710 is provided on a control loop of the heating circuit, and is disconnected when the temperature of the heating circuit is greater than or equal to a first temperature threshold, and is restored when the temperature of the heating circuit is less than the first temperature threshold; the second thermostat 720 is provided on the control loop of the heating circuit and is connected in series with the first thermostat 710, and is disconnected when the temperature of the heating circuit is greater than or equal to the second temperature threshold.

[0085] It is understood that the heating circuit can be a resistor with a certain trajectory. The heating circuit receives the driving current from the control unit and generates heat. The control unit can adjust the temperature of the heating circuit by adjusting the current value of the driving current. The temperature of the heating circuit can be determined by detecting the surface temperature of the heating layer 200. The control loop of the heating circuit refers to the connection loop between the control unit and the heating circuit, and the control unit transmits the driving current to the heating circuit through the control loop.

[0086] The control circuit is switched on and off by the first thermostat 710 and the second thermostat 720. When either the first thermostat 710 or the second thermostat 720 is in the off state, the control circuit is disconnected, the heating circuit cannot receive the driving current, heating stops, and the temperature gradually decreases. When both the first thermostat 710 or the second thermostat 720 are in the connected state, the control circuit is connected, the heating circuit receives the driving current, heating occurs, and the temperature rises or remains constant.

[0087] It should be noted that the first thermostat 710 is a recoverable thermostat, that is, when the temperature of the heating circuit changes from a state greater than or equal to the first temperature threshold to less than the first temperature threshold, the first thermostat 710 can automatically recover from the disconnected state to the connected state. The second thermostat 720 is a non-recoverable thermostat, that is, when the temperature of the heating circuit changes from a state greater than or equal to the second temperature threshold to less than the second temperature threshold, the second thermostat 720 remains disconnected. The first threshold and the second threshold range from 165°C to 200°C, and the second threshold is greater than the first threshold, for example, the second threshold is 175°C and the first threshold is 170°C.

[0088] According to the thick film heater of the embodiment of the present application, a recoverable thermostat and an irreversible thermostat are set to detect the surface temperature of the thick film heater in the working state. The two-stage thermostat can enable the thick film heater to have a certain temperature regulation ability, automatically lower the temperature when the temperature is slightly higher, and stop heating and disconnect protection when the temperature is too high, thereby preventing the thick film heater from overheating and drying out.

[0089] In some embodiments of the present application, the thick film heater may further include a first temperature sensor 810, a second temperature sensor 820, and a control unit. The first temperature sensor 810 is configured to detect a first temperature of the fluid flowing into the thick film heater; the second temperature sensor 820 is configured to detect a second temperature of the fluid flowing out of the thick film heater; and the control unit is electrically connected to the first temperature sensor 810, the first temperature sensor 820, and the heating circuit, respectively, and is configured to control the heating circuit based on the first and second temperatures.

[0090] It is understood that when the thick film heater is in operation, the medium needs to be heated to a target temperature. The target temperature can be a temperature input by the user, or determined by the thick film heater's control unit according to an internally running program. The first temperature is the temperature of the medium before heating, and the second temperature is the temperature of the medium after heating. Based on a first difference between the first temperature and the target temperature, and a second difference between the second temperature and the target temperature, the heating circuit can be controlled to operate at an appropriate heating power. The heating power corresponding to the first difference and the second difference can be set according to demand, and the driving technology of the heating circuit is also mature, so this embodiment will not be described in detail here.

[0091] According to the thick film heater of the embodiment of the present application, a temperature sensor is set to detect the temperature of the medium before and after heating, and the heating circuit is controlled according to the detection results, thereby facilitating the adjustment of the heating power of the heating circuit to heat the medium to the target temperature.

[0092] In some embodiments, the thick film heater may further include a protective shell 900. The protective shell 900 is mounted on the heat conductor 100 to isolate the heat conductor 100 from the outside and prevent other components or users from contacting the surface of the heat conductor 100. The thick film heater is usually one of the components within the device. The protective shell 900 may also be provided with mounting holes 910 at both ends of the upper side. The mounting holes 910 facilitate the installation of the thick film heater into the device. At the same time, the protective shell 900 can also provide a certain degree of thermal insulation to prevent the heat generated by the thick film heater from affecting other components within the device.

[0093] In some embodiments, the first thermostat 710 and the second thermostat 720 can be mounted on the protective shell 900. The thick film heater can further include a connector 1000. One end of the connector 1000 can be provided with a connection hole 1001, which can be used to connect to the first thermostat 710 and the second thermostat 720. The other end of the connector 1000 is fixed to the protective shell 900 or to the device where the thick film heater is located, thereby fixing the first thermostat 710 and the second thermostat 720.

[0094] In some embodiments, an input mechanism 1100 and an output mechanism 1200 may be provided at both ends of the thick film heater. The input mechanism 1100 has an input port 1101, and the output mechanism 1200 has an output port 1201. Both the input port 1101 and the output port 1201 communicate with the aforementioned heating channel or spiral channel to allow the medium to enter and exit. The thick film heater may also include a sealing gasket 1300 (such as a waterproof gasket), which is provided between the input mechanism 1100 and the heat conductor 100 and between the output mechanism 1200 and the heat conductor 100 to prevent leakage of the medium.

[0095] In some embodiments, the input port 1101 and the output port 1201 may be provided with openings, through which the first temperature sensor 810 and the second temperature sensor 820 extend into the pipeline and contact the medium, thereby improving the accuracy of the medium temperature detection.

[0096] Referring to Figure 4 , the present application also provides a heater. The heater includes a heat conductor 100 and a heating layer 200 . The heat conductor 100 is cylindrical and has a through-going heating channel 300 . The heating layer 200 is axially disposed on the outer surface of the heat conductor 100 . The heating layer 200 includes multiple heating regions, each generating a different amount of heat. When the heater is operating, the region with the smallest amount of heat generated is arranged upward.

[0097] In this embodiment, the heat conductor 100 can be made of a metal material (such as copper) or a heat-conducting material such as stainless steel. The heating channel 300 is used to transport the medium. When the medium passes through the heating channel 300, the heat conductor 100 transfers the heat generated by the heating layer 200 to the medium, thereby heating the medium. The medium can be water or oil, etc., and this embodiment uses water as an example.

[0098] The heat conductor 100 may be cylindrical, but it may also be in other shapes, such as a square column. This embodiment is described using a cylindrical shape as an example. The heating channel 300 may have the same shape as the heat conductor 100, such as a circular channel, thereby providing a larger flow area within a limited size.

[0099] In this embodiment, the heater is a thick film heater. The heating layer 200 can be a heating circuit formed using screen printing technology, which can be formed by sequentially printing a dielectric layer and a resistor layer. The printing process for the heating layer 200 of a thick film heater is a mature technology and will not be further described in this embodiment.

[0100] In some embodiments, the heat conductor 100 has a certain width at both ends, and the area surrounding it along the circumference serves as a reserved section 500, which is used to connect to the water system. The heater needs to be connected to the water system, such as a water inlet and outlet mechanism can be installed at both ends of the heater. Therefore, by providing a reserved section 500 for connecting to the water system, interference between the water system and the heating layer 200 is avoided. The area between the two reserved sections 500 on the heat conductor 100 serves as a printing section, which is used to print the heat conductor 100.

[0101] In some embodiments, the resistance layer of the heating layer 200 is formed with resistance tracks. The resistance tracks in each heating area can have the same width and length, but the spacing between the resistance tracks in each heating area is different, thereby forming different resistance track distribution densities, so that the heating areas have different heating values.

[0102] In some embodiments, the resistance tracks in each heating area may be arranged at the same interval, but the width and length of the resistance tracks in each heating area are different, so that each heating area has a different heating value.

[0103] In this embodiment, the heater can be connected to an external water supply circuit, and the heater can be arranged horizontally or tilted. Water flows into the heater from one side and out from the other side. When the water flow rate is sufficient, the water flows to fill the entire heating channel 300 in the heater; when the water flow rate is insufficient, the water flow cannot fill the entire heating channel 300 in the heater. At this time, due to the action of gravity, the amount of water in the heating channel 300 covers the lower part, and the upper part forms a hollow part. The smaller the water flow rate, the larger the space of the hollow part, and the correspondingly larger the inner wall area not covered by the water flow, and the more serious the dry burning of the heater.

[0104] It's understood that to prevent dry burning, the heater should be arranged so that the heating area with the lowest heat output is located where dry burning is most likely to occur. Common heater arrangements include tilted and horizontal arrangements. In a tilted arrangement, the location most susceptible to dry burning is the upper surface of the higher end of the heat conductor 100; in a horizontal arrangement, the location most susceptible to dry burning is the upper surface of the entire heat conductor 100.

[0105] When the heater is tilted, the heating area with the minimum heat output is arranged upward, meaning that the heating area with the minimum heat output is located on the upper surface of the higher end of the heat conductor 100 and is arranged toward the top of the heater. When the heater is tilted and horizontally arranged, the heating area with the minimum heat output is arranged upward, meaning that the heating area with the minimum heat output is arranged toward the top of the heater. In this way, the heating area with the minimum heat output is located at the top of the heat conductor 100. When the medium is insufficient, the top of the heating channel 300 is not covered by the medium. However, since the heating area with the minimum heat output at the top does not generate heat, the heater will not dry-burn when the medium is insufficient.

[0106] According to the heater of the present application, the heating layer is unevenly arranged on the outer surface of the heat conductor 100, forming a plurality of heating areas with different heat amounts, and the heating area with the smallest heat amount is set upward, so that when the heater is in use, the heat amount of the part facing the upper equipment is lower. When the medium is not sufficient to completely cover the heater, the heat amount of the uncovered part is lower, thereby avoiding dry burning and overheating.

[0107] In some embodiments of the present application, the heating area includes a first heating area 210 and a second heating area 220 . The heat generated by the first heating area 210 is less than that of the second heating area 220 . The first heating area 210 is evenly arranged along the axial direction.

[0108] In this embodiment, the heating layer 200 is divided into two heating areas, the resistance track density in the first heating area 210 is less than the resistance track density in the second heating area 220, or the resistance track length or width in the first heating area 210 is less than the length or width of the second heating area 220.

[0109] The first heating regions 210 are evenly arranged along the axial direction. When the first heating regions 210 face upward, the upper portion of the heater forms a uniform heating region with reduced heat output along the axial direction. When the dielectric material is insufficient to cover the heating channel, the uncovered area maximizes the coverage of the first heating regions 210, thus preventing dry heating. This also simplifies printing of the heating layer 200.

[0110] In some embodiments of the present application, the area of ​​the first heating region 210 accounts for 5% to 15% of the area of ​​the heating layer 200 .

[0111] It is understood that the provision of the first heating region 210 will reduce the maximum heating value of the heater, and the larger the area of ​​the first heating region 210, the lower the maximum heating value of the heater. Therefore, the area of ​​the first heating region 210 should not be too large. By setting the area of ​​the first heating region 210 to account for 5% to 15% of the area of ​​the heating layer 200, the provision of the first heating region 210 is prevented from affecting the heating performance of the heater.

[0112] In some embodiments, the area of ​​the first heating region 210 accounts for 7% of the area of ​​the heating layer 200 .

[0113] According to the heater of the embodiment of the present application, by setting the area of ​​the first heating region 210 to account for 7% of the area of ​​the heating layer 200, the heater is prevented from dry burning while ensuring sufficient heating performance.

[0114] 2 , in some embodiments of the present application, the heater may further include a conveying shaft 600 . The conveying shaft 600 is disposed in the heat conductor 100 and has a spiral sheet 610 formed along the axial direction thereof. The spiral sheet 610 is used to cooperate with the inner wall of the heating channel 300 to form a spiral channel.

[0115] It should be noted that after the delivery shaft 600 is installed in the heat conductor 100, the original heating channel 300 is replaced by a spiral channel. After entering the heat conductor 100, the medium flows along the spiral channel. Compared with a straight heating channel, the spiral channel increases the surface area of ​​the water flow, thereby improving the water heating efficiency without changing the heating power and size of the heating tube.

[0116] It should be noted that to facilitate the insertion and removal of the conveyor shaft 600 into and from the heating channel 300, a certain distance can be provided between the outer diameter of the spiral blade 610 and the inner wall of the heating channel 300. Furthermore, to ensure that the water flows along the spiral channel, this distance should not be too large. In some embodiments, the outer diameter of the spiral blade 610 can be 0.5 to 1.5 mm narrower than the diameter of the heating channel 300.

[0117] In some embodiments, the outer diameter of the spiral blade 610 can be 0.5 mm narrower than the diameter of the heating channel 300, reducing the flow rate of water flowing in a straight line along the axial direction of the heater in the gap between the spiral blade 610 and the inner wall of the heating channel 300, allowing the water to flow in the spiral channel, thereby improving the heating effect.

[0118] In this embodiment, the length L of the spiral piece 610 can be equal to the axial length of the heating layer 200. If the length of the spiral piece 610 is too long, the water flow in the two ends of the spiral channel cannot be heated, but will lead to a decrease in the overall flow rate of the water flow. If the length of the spiral piece 610 is too short, the water flow in the two ends of the heating channel 300 is large and the heating effect is poor. Therefore, when the length of the spiral piece 610 can be equal to the axial length of the heating layer 200, the water flow can be heated most effectively and the flow rate is less affected.

[0119] It is understood that if the thickness of the spiral blade 610 is too thick, it will reduce the space in the spiral channel, thereby reducing the heating effect of the heater. Therefore, the thickness of the spiral blade 610 can be as thin as possible while ensuring strength. In some embodiments, the thickness of the spiral blade 610 can be 0.8 mm to 3 mm, such as 1.2 mm.

[0120] In some embodiments, the conveying shaft 600 further includes sealing portions 620 at both ends of the spiral blade 610. These sealing portions 620 include through-holes 621, which are identical to the spiral channel. The sealing portions 800 seal the heating channel 300 at both ends of the spiral blade 610, allowing the spiral channel to communicate with the external space through the through-holes 621. The through-holes 621 at both ends can serve as the water inlet or outlet of the spiral channel.

[0121] According to the heater of the embodiment of the present application, the medium is transported in the heater by utilizing the spiral channel, so that the medium is evenly heated, thereby improving the heating efficiency of the heater.

[0122] In some embodiments of the present application, the spiral pitch at both ends of the spiral sheet 610 is greater than the spiral pitch in the middle section.

[0123] Referring to Figure 2 , it should be noted that the spiral pitch at both ends of the spiral piece 610 refers to a first distance L1 between the connecting surface of the through hole 621 and the spiral channel and the opposite spiral piece, and the spiral pitch in the middle section of the spiral piece 610 refers to a second distance L2 between two adjacent spiral pieces. Furthermore, since the spiral piece 610 is continuous, the spiral pitch at both ends of the spiral piece 610 gradually decreases as it approaches the middle section.

[0124] It is understandable that the cross-sectional area of ​​the spiral channel is smaller than the cross-sectional area of ​​the external water channel. Therefore, when the water flows into the spiral channel from the external water channel or flows out from the spiral water channel to the external water channel, the water channel may suddenly narrow and flow poorly. Among them, the cross-sectional area of ​​the spiral channel refers to the area of ​​the cross section along the opposite direction of the channel perpendicular to the spiral channel. By making the spiral pitch at both ends of the spiral sheet 610 larger than the spiral pitch in the middle section, the fluid flow space at both ends of the spiral water channel is increased, thereby reducing the sudden change in flow when the water flows into the spiral channel from the external water channel or flows out from the spiral water channel to the external water channel, making the water flow smoother.

[0125] In some embodiments of the present application, the ratio of the spiral pitch of the middle section of the spiral sheet 610 to the axial length of the heating layer 200 is 1:3 to 1:8.

[0126] It should be noted that, given a given length of the spiral blade 610, a larger ratio of the spiral pitch in the middle section of the spiral blade 610 to the axial length of the heating layer indicates a longer spiral channel. However, an excessively long spiral channel may cause water blockage. A smaller ratio of the spiral pitch in the middle section of the spiral blade 610 to the axial length of the heating layer indicates a shorter spiral channel. However, an excessively short spiral channel may cause water to flow through the heater too quickly, resulting in lower heating efficiency.

[0127] In some embodiments, the ratio of the spiral pitch of the middle section of the spiral sheet 610 to the axial length of the heating layer can be determined according to the heating power of the heating layer 200. When the heating power of the heating layer 200 is high, a shorter spiral channel can be provided, that is, the ratio of the spiral pitch of the middle section of the spiral sheet 610 to the axial length of the heating layer is low; when the heating power of the heating layer 200 is low, a longer spiral channel can be provided, that is, the ratio of the spiral pitch of the middle section of the spiral sheet 610 to the axial length of the heating layer is large.

[0128] In some embodiments, the ratio of the spiral pitch of the middle section of the spiral 610 to the axial length of the heating layer 200 is 1:7.

[0129] According to the heater of the embodiment of the present application, the length of the spiral channel is moderate, and the water flow is not easily blocked when passing through the spiral channel. At the same time, the water flow can be fully heated in the spiral channel, thereby improving the heating effect of the heater.

[0130] 5 , in some embodiments of the present application, the heating layer 200 is formed with a heating circuit, and the heater may further include a first thermostat 710 and a second thermostat 720. The first thermostat 710 is provided on a control loop of the heating circuit, and is disconnected when the temperature of the heating circuit is greater than or equal to a first temperature threshold, and is restored when the temperature of the heating circuit is less than the first temperature threshold; the second thermostat 720 is provided on the control loop of the heating circuit and is connected in series with the first thermostat 710, and is disconnected when the temperature of the heating circuit is greater than or equal to the second temperature threshold.

[0131] It is understood that the heating circuit can be a resistor with a certain trajectory. The heating circuit receives the driving current from the control unit and generates heat. The control unit can adjust the temperature of the heating circuit by adjusting the current value of the driving current. The temperature of the heating circuit can be determined by detecting the surface temperature of the heating layer 200. The control loop of the heating circuit refers to the connection loop between the control unit and the heating circuit, and the control unit transmits the driving current to the heating circuit through the control loop.

[0132] The control circuit is switched on and off by the first thermostat 710 and the second thermostat 720. When either the first thermostat 710 or the second thermostat 720 is in the off state, the control circuit is disconnected, the heating circuit cannot receive the driving current, heating stops, and the temperature gradually decreases. When both the first thermostat 710 or the second thermostat 720 are in the connected state, the control circuit is connected, the heating circuit receives the driving current, heating occurs, and the temperature rises or remains constant.

[0133] It should be noted that the first thermostat 710 is a recoverable thermostat, that is, when the temperature of the heating circuit changes from a state greater than or equal to the first temperature threshold to less than the first temperature threshold, the first thermostat 710 can automatically recover from the disconnected state to the connected state. The second thermostat 720 is a non-recoverable thermostat, that is, when the temperature of the heating circuit changes from a state greater than or equal to the second temperature threshold to less than the second temperature threshold, the second thermostat 720 remains disconnected. The first threshold and the second threshold range from 165°C to 200°C, and the second threshold is greater than the first threshold, for example, the second threshold is 175°C and the first threshold is 170°C.

[0134] According to the heater of the embodiment of the present application, a recoverable thermostat and an irreversible thermostat are set to detect the surface temperature of the heater in the working state. The two-stage thermostat can enable the heater to have a certain temperature regulation ability, automatically lower the temperature when the temperature is slightly higher, and stop heating and disconnect protection when the temperature is too high, thereby preventing the heater from overheating and dry burning.

[0135] In some embodiments of the present application, the heater may further include a first temperature sensor 810, a second temperature sensor 820, and a control unit. The first temperature sensor 810 is configured to detect a first temperature of the fluid flowing into the heater; the second temperature sensor 820 is configured to detect a first temperature of the fluid flowing out of the heater; and the control unit is electrically connected to the first temperature sensor 810, the first temperature sensor 820, and the heating circuit, respectively, and is configured to control the heating circuit based on the first and second temperatures.

[0136] It is understood that when the heater is in operation, the medium needs to be heated to a target temperature. This target temperature can be a temperature input by the user, or determined by the heater control unit according to an internal program. The first temperature is the temperature of the medium before heating, and the second temperature is the temperature of the medium after heating. Based on a first difference between the first temperature and the target temperature, and a second difference between the second temperature and the target temperature, the heating circuit can be controlled to operate at an appropriate heating power. The heating power corresponding to the first difference and the second difference can be set according to demand. The driving technology of the heating circuit is also mature, and this embodiment will not be described in detail here.

[0137] According to the heater of the embodiment of the present application, a temperature sensor is set to detect the temperature of the medium before and after heating, and the heating circuit is controlled according to the detection results, thereby facilitating the adjustment of the heating power of the heating circuit to heat the medium to the target temperature.

[0138] In some embodiments, the heater may further include a protective shell 900. The protective shell 900 is mounted on the heat conductor 100 to isolate the heat conductor 100 from the outside and prevent other components or users from contacting the surface of the heat conductor 100. The heater is usually one of the components inside the device. The protective shell 900 may also be provided with mounting holes 910 at both ends of the upper side. The mounting holes 910 facilitate the installation of the heater into the device. At the same time, the protective shell 900 can also provide a certain degree of thermal insulation to prevent the heat generated by the heater from affecting other components inside the device.

[0139] In some embodiments, the first thermostat 710 and the second thermostat 720 can be mounted on the protective shell 900. The heater can further include a connector 1000, one end of which can be provided with a connection hole 1001, which can be used to connect with the first thermostat 710 and the second thermostat 720. The other end of the connector 1000 is fixed to the protective shell 900 or to the device where the heater is located, thereby fixing the first thermostat 710 and the second thermostat 720.

[0140] In some embodiments, an input mechanism 1100 and an output mechanism 1200 may be provided at both ends of the heater. The input mechanism 1100 has an input port 1101, and the output mechanism 1200 has an output port 1201. Both the input port 1101 and the output port 1201 communicate with the aforementioned heating channel or spiral channel to allow the medium to enter and exit. The heater may also include a sealing gasket 1300 (such as a waterproof gasket), which is provided between the input mechanism 1100 and the heat conductor 100 and between the output mechanism 1200 and the heat conductor 100 to prevent leakage of the medium.

[0141] In some embodiments, the input port 1101 and the output port 1201 may be provided with openings, through which the first temperature sensor 810 and the second temperature sensor 820 extend into the pipeline and contact the medium, thereby improving the accuracy of the medium temperature detection.

[0142] An embodiment of the present application further provides a heating device, which includes the thick film heater according to any one of the aforementioned embodiments or the heater according to any one of the aforementioned embodiments.

[0143] According to the heating device of the present application, the upward portion of the heater does not generate heat or generates a low amount of heat. When the medium is insufficient to completely cover the heater, the uncovered portion does not generate heat or generates a low amount of heat, thereby avoiding dry burning and overheating.

[0144] The specific structure of the heater can refer to the aforementioned embodiments. Since the heating device of the embodiment of the present application can apply at least one of the heaters of the above embodiments, the heating device can have the technical effects of the above embodiments, and this embodiment will not be repeated here.

[0145] An embodiment of the present application also provides a heating device, which includes: a water tank; a main unit connected to the water tank and forming a circulating water circuit, the main unit including a thick film heater according to any one of the aforementioned embodiments or a heater according to any one of the aforementioned embodiments, the thick film heater or the heater is arranged on the circulating water circuit and is used to heat the water flow in the circulating water circuit.

[0146] In some embodiments, the heating device can be a slow cooker. The circulating water circuit refers to a water supply line whose inlet and outlet are connected to a water tank. Water in the tank circulates through the circulating water circuit. Food is placed in the water tank, which contains a liquid. The main unit draws water from the tank and sends it to the heater for heating. The heated water is then returned to the tank, continuing this cycle to heat the water in the tank to the target temperature. By heating the liquid, the main unit heats the food in the water.

[0147] According to the heating device of the present application, the upward portion of the heater does not generate heat or generates a low amount of heat. When the medium is insufficient to completely cover the heater, the uncovered portion does not generate heat or generates a low amount of heat, thereby avoiding dry burning and overheating.

[0148] In some embodiments of the present application, the angle between the thick film heater or the arrangement direction of the heater and the vertical direction is greater than 0 degree.

[0149] In some embodiments, the heater in a slow cooker can be arranged horizontally or tilted, with the spacer 400 on the heat conductor 100 facing upward. This prevents the heater from burning dry. Furthermore, the operating screen of a slow cooker is typically located above the heater. If the heater generates too much heat, the screen may overheat. This embodiment, by arranging the spacer 400 on the heat conductor 100 facing upward, can also reduce the amount of heat generated by the heater, preventing screen overheating.

[0150] The terms "first," "second," and the like in the specification and claims of this application are used to distinguish similar objects, and are not used to describe a specific order or precedence. It should be understood that the terms used in this manner are interchangeable where appropriate, so that the embodiments of this application can be implemented in an order other than that illustrated or described herein, and that the objects distinguished by "first," "second," and the like are generally of the same type, and do not limit the number of objects; for example, the first object can be one or more. In addition, the term "and / or" in the specification and claims refers to at least one of the connected objects, and the character " / " generally indicates that the objects connected are in an "or" relationship.

[0151] In the description of the present application, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "axial", "radial", "circumferential" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present application.

[0152] In the description of the present application, a first feature being “on” or “under” a second feature may include the first and second features being in direct contact with each other, or the first and second features being in contact with each other not directly but via another feature therebetween.

[0153] In the description of this application, a first feature “on”, “above” and “above” a second feature includes the first feature being directly above and obliquely above the second feature, or simply means that the first feature is horizontally higher than the second feature.

[0154] Other components of the heater according to the embodiment of the present application, such as the heating circuit and the sensor, and operations are known to those skilled in the art and will not be described in detail here.

[0155] Throughout this specification, reference to terms such as "one embodiment," "some embodiments," "illustrative embodiments," "examples," "specific examples," or "some examples" means that the specific features, structures, materials, or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

[0156] Although the embodiments of the present application have been shown and described, those skilled in the art will appreciate that various changes, modifications, substitutions, and variations may be made to the embodiments without departing from the principles and purpose of the present application, and that the scope of the present application is defined by the claims and their equivalents.

Claims

1. A thick film heater, characterized in that include: The heat conductor is columnar and has a through heating channel; The heating layer is axially arranged on the outer surface of the heat conductor, and at least part of the sections are discontinuous in the circumferential direction to form a spacing area. When the heater is in heating operation, the spacing area is arranged upward.

2. The thick film heater according to claim 1, wherein The spacing areas are evenly arranged in the axial direction, and the entire heating layer is discontinuous in the circumferential direction.

3. The thick film heater according to claim 2, characterized in that The area of ​​the spacing zone accounts for 5% to 15% of the outer surface area of ​​the heat conductor.

4. The thick film heater according to any one of claims 1 to 3, characterized in that The thick film heater further comprises: The conveying shaft is arranged in the heat conductor, and the conveying shaft is formed with a spiral piece along the axial direction. The spiral piece is used to cooperate with the inner wall of the heating channel to form a spiral channel.

5. The thick film heater according to claim 4, characterized in that The spiral pitch at both ends of the spiral sheet is greater than the spiral pitch in the middle section.

6. The thick film heater according to claim 5, characterized in that The ratio of the spiral pitch of the middle section of the spiral sheet to the axial length of the heating layer is 1:3 to 1:

8.

7. The thick film heater according to any one of claims 1 to 3, characterized in that The heating layer is formed with a heating circuit, and the thick film heater further comprises: a first thermostat, provided on a control loop of the heating circuit, disconnected when the temperature of the heating circuit is greater than or equal to a first temperature threshold, and restored when the temperature of the heating circuit is less than the first temperature threshold; The second thermostat is provided on the control loop of the heating circuit and is connected in series with the first thermostat, and is disconnected when the temperature of the heating circuit is greater than or equal to a second temperature threshold.

8. The thick film heater according to claim 7, characterized in that The thick film heater further comprises: a first temperature sensor for detecting a first temperature of the fluid flowing into the heater; a second temperature sensor for detecting a second temperature of the fluid flowing out of the heater; A control unit is connected to the first temperature sensor, the second temperature sensor and the heating circuit respectively, and is used to control the heating circuit according to the first temperature and the second temperature.

9. A heater, characterized in that: The heater comprises: The heat conductor is columnar and has a through heating channel; The heating layer is axially arranged on the outer surface of the heat conductor. The heating layer includes multiple heating areas, and the heating amounts of each heating area are different. When the heater is in heating operation, the heating area with the smallest heat amount among the heating areas is arranged upward.

10. The heater according to claim 9, characterized in that The plurality of heating areas include a first heating area and a second heating area. The heat generated by the first heating area is less than that of the second heating area. The first heating areas are evenly arranged along the axial direction.

11. The heater according to claim 10, characterized in that The area of ​​the first heating region accounts for 5% to 15% of the area of ​​the heating layer.

12. The heater according to any one of claims 9 to 11, characterized in that The heater further comprises: The conveying shaft is arranged in the heat conductor, and the conveying shaft is formed with a spiral piece along the axial direction. The spiral piece is used to cooperate with the inner wall of the heating channel to form a spiral channel.

13. The heater according to claim 12, characterized in that The spiral pitch at both ends of the spiral sheet is greater than the spiral pitch in the middle section.

14. The heater according to claim 13, wherein The ratio of the spiral pitch of the middle section of the spiral sheet to the axial length of the heating layer is 1:3 to 1:

8.

15. The heater according to any one of claims 9 to 11, characterized in that The heating layer is formed with a heating circuit, and the heater further comprises: a first thermostat, provided on a control loop of the heating circuit, disconnected when the temperature of the heating circuit is greater than or equal to a first temperature threshold, and restored when the temperature of the heating circuit is less than the first temperature threshold; The second thermostat is provided on the control loop of the heating circuit and is connected in series with the first thermostat, and is disconnected when the temperature of the heating circuit is greater than or equal to a second temperature threshold.

16. The heater according to claim 15, characterized in that The heater further comprises: a first temperature sensor for detecting a first temperature of the fluid flowing into the heater; a second temperature sensor for detecting a second temperature of the fluid flowing out of the heater; A control unit is connected to the first temperature sensor, the second temperature sensor and the heating circuit respectively, and is used to control the heating circuit according to the first temperature and the second temperature.

17. A heating device, characterized in that: The heating device comprises a thick film heater according to any one of claims 1-8 or a heater according to any one of claims 9-16.

18. A heating device, characterized in that: The heating device comprises: water tank; The main unit is connected to the water tank and forms a circulating water circuit. The main unit includes a thick film heater according to any one of claims 1 to 8 or a heater according to any one of claims 9 to 16. The thick film heater or the heater is arranged on the circulating water circuit and is used to heat the water flow in the circulating water circuit.

19. The heating device according to claim 18, characterized in that An angle between the arrangement direction of the thick film heater or the heater and a vertical direction is greater than 0 degrees.

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