CN115930428A

CN115930428A - Thick film heater, heater and heating equipment

Info

Publication number: CN115930428A
Application number: CN202211461167.9A
Authority: CN
Inventors: 陈旭潮; 罗凯戈
Original assignee: Shenzhen Huyi Technology Co Ltd
Current assignee: Shenzhen Huyi Technology Co Ltd
Priority date: 2022-11-21
Filing date: 2022-11-21
Publication date: 2023-04-07

Abstract

The application discloses thick film heater, heater and firing equipment belongs to heater technical field. A thick film heater comprising: the heat conductor is columnar and is provided with a through heating channel; and the heat generating layer is arranged on the outer surface of the heat conductor along the axial direction, at least part of sections of the heat generating layer are discontinuous in the circumferential direction so as to form a spacer, and when the heater is used for heating, the spacer faces upwards. According to the thick film heater, the heating layer does not completely cover the surface of the heater, and the area which is not covered with the heating layer faces upwards, so that when the thick film heater is used, the part facing upwards equipment does not generate heat, and when the medium is not enough to completely cover the thick film heater, the area which is not heated is arranged in the part which is not covered with the heating layer, and the overheating caused by dry burning is avoided.

Description

Thick film heater, heater and heating equipment

Technical Field

The application relates to the technical field of heaters, in particular to a thick film heater, a heater and heating equipment.

Background

The heat generating layer of a thick film heater is generally covered on the surface of a heating channel, and when the medium in the heating channel is insufficient, a hollow part exists in the heating channel, and the hollow part is easy to gather bubbles, so that local dry burning is caused, and the device is damaged.

Disclosure of Invention

The present application is directed to solving at least one of the problems in the prior art. To this end, the application proposes a thick film heater, a heater and a heating device. When the thick film heater is used, the uncovered part has a non-heating area, so that dry burning overheating is avoided.

In a first aspect, the present application provides a thick film heater comprising: the heat conductor is columnar and is provided with a through heating channel; the heating layer is arranged on the outer surface of the heat conductor along the axial direction, at least part of the heating layer is discontinuous in the circumferential direction to form a spacer area, and when the heater is in heating operation, the spacer area is arranged towards the upper side.

According to the thick film heater, the heating layer does not completely cover the surface of the heater, and the area which is not covered with the heating layer faces upwards, so that when the thick film heater is used, the part facing upwards equipment does not generate heat, and when the medium is not enough to completely cover the thick film heater, the area which is not heated is arranged in the part which is not covered with the heating layer, and the overheating caused by dry burning is avoided.

According to one embodiment of the present application, the spacers are arranged uniformly in the axial direction, and the entire section of the heat generating layer is discontinuous in the circumferential direction.

According to an embodiment of the present application, the area of the spacer area accounts for 5% to 15% of the area of the outer surface of the heat conductor.

According to one embodiment of the present application, the thick film heater further comprises: the conveying shaft is arranged in the heat conductor, a spiral sheet is formed on the conveying shaft along the axial direction, and the spiral sheet is matched with the inner wall of the heating channel to form a spiral channel.

According to one embodiment of the present application, the helical pitch at both ends of the helical sheet is greater than the helical pitch at the middle section.

According to one embodiment of the application, the ratio of the spiral distance of the middle section of the spiral sheet to the axial length of the heating layer is 1:3 to 1:8.

according to an embodiment of the present application, the heat-generating layer is formed with a heating circuit, the thick film heater further comprising: the first temperature controller is arranged on a control loop of the heating circuit, is disconnected when the temperature of the heating circuit is greater than or equal to a first temperature threshold value, and is restored to be connected when the temperature of the heating circuit is less than the first temperature threshold value; and the second temperature controller is arranged on the control loop of the heating circuit, is connected with the first temperature controller in series, and is disconnected when the temperature of the heating circuit is greater than or equal to a second temperature threshold value.

According to one embodiment of the present application, 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; and the control unit is respectively connected with the first temperature sensor, the first temperature sensor and the heating circuit and is used for controlling the heating circuit according to the first temperature and the second temperature.

In a second aspect, the present application also provides a heater comprising: the heat conductor is columnar and is provided with a through heating channel; the heating layer is arranged on the outer surface of the heat conductor along the axial direction and comprises a plurality of heating areas, the heating amount of each heating area is different, and when the heater is in heating operation, the heating area with the minimum heating amount in each heating area faces upwards.

According to the heater, the heating layers are unevenly arranged on the outer surface of the heat conductor to form a plurality of heating areas with different heating values, and the heating area with the smallest heating value faces upwards, so that when the heater is used, the heating value of the part facing upwards equipment is lower, and when a medium is not enough to cover the heater, the heating value of the part which is not covered is lower, and the overheating caused by dry burning is avoided.

According to an embodiment of the present application, the plurality of heat generation regions include a first heat generation region and a second heat generation region, the first heat generation region having a smaller amount of heat generation than the second heat generation region, the first heat generation regions being uniformly arranged in the axial direction.

In a third aspect, the present application provides a heating apparatus comprising a thick film heater according to any preceding embodiment or a heater according to any preceding embodiment.

According to the heating equipment, the upward part of the heater does not generate heat or generates low heat, and when the medium is not enough to completely cover the heater, the part which is not covered does not generate heat or generates low heat, so that dry burning overheating is avoided.

In a fourth aspect, the present application provides a heating apparatus comprising: a water tank; a main unit connected to the water tank and forming a circulation water path, the main unit including the thick film heater according to any one of the preceding embodiments or the heater according to any one of the preceding embodiments, the thick film heater or the heater being provided on the circulation water path for heating water flow in the circulation water path.

According to one embodiment of the application, the thick film heater or the angle between the direction of arrangement of the heater and the vertical is greater than 0 degrees.

Drawings

The above and/or additional aspects and advantages of the present application will become apparent and readily appreciated from the following description of the embodiments, taken in conjunction with the accompanying drawings of which:

FIG. 1 is a schematic structural diagram of a heater provided in an embodiment of the present application;

FIG. 2 is a schematic structural diagram of a conveying shaft provided in an embodiment of the present application;

FIG. 3 is an exploded view of a heater according to an embodiment of the present application;

FIG. 4 is a schematic structural diagram of a heater provided in an embodiment of the present application;

fig. 5 is a second exploded view of the heater according to the embodiment of the present application.

Reference numerals are as follows:

a heat conductor 100;

a heat generating layer 200, a first heat generating region 210, a second heat generating region 220;

a heating channel 300;

a spacer 400;

a reserved segment 500;

a conveying shaft 600, a spiral sheet 610, a sealing part 620, and a through hole 621;

a first thermostat 710, a second thermostat 720;

a first temperature sensor 810, a second temperature sensor 820;

a protective case 900, a mounting hole 910;

a connecting member 1000, a connecting hole 1001;

input mechanism 1100, input port 1101;

an output port 1201 of the output mechanism 1200;

the rubber mat 1300 is sealed.

Detailed Description

Reference will now be made in detail to the embodiments of the present application, examples of which are illustrated in the accompanying drawings, wherein like reference numerals refer to the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are illustrative and are only for the purpose of explaining the present application and are not to be construed as limiting the present application.

Referring to fig. 1, one embodiment of the present application provides a thick film heater. The thick film heater includes a heat conductor 100 and a heat generating layer 200. The heat conductor 100 is columnar and is formed with a through heating channel 300; the heat generating layer 200 is axially printed on the outer surface of the heat conductor 100, and at least a part of the segments are discontinuous in the circumferential direction to form a spacer 400, and the spacer 400 is arranged to face upward when the thick film heater is in heating operation.

In this embodiment, the heat conductor 100 may be made of a metal material (such as copper), or a heat conducting material such as stainless steel. The heating channel 300 is used for conveying a medium, and when the medium passes through the heating channel 300, the heat conductor 100 transfers heat generated by the heat generating layer 200 to the medium, so that the medium is heated. The medium may be water, oil, or the like, and water is used as an example in the present embodiment.

The thermal conductor 100 may be cylindrical, but may also be other shapes, such as square column. This embodiment will be described by taking 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, and thus have a high flow area within a limited size.

It is understood that the heat generating layer 200 may be a heating circuit formed using a screen printing technique, which may be formed by sequentially printing a dielectric layer and a resistive layer.

In some embodiments, the heat conductor 100 has a width at both ends, and the circumferentially surrounding area is used as a reserved section 500, and the reserved section 500 is used for connecting with a waterway system. The thick film heater needs to be connected with a waterway system, and a water inlet mechanism and a water outlet mechanism can be arranged at the two ends of the thick film heater. Therefore, the reserved section 500 is arranged to be connected with the waterway system, and the waterway system is prevented from interfering with the heating layer 200.

It should be noted that, a printing section is provided between two reserved sections 500 on the heat conductor 100, the printing section is used for printing the heat conductor 100, and an area of the heat conductor 100 on the outer surface of the printing section that is not covered by the heat conductor 100 is the spacer 400. Since the heat generating layer 200 is not disposed in the spacer 400, heat is not generated when the thick film heater operates. Therefore, even if the inner wall of the heating channel 300 corresponding to the spacer 400 is not covered with the medium, there is no dry burning.

In some embodiments, the spacers 400 may include a plurality of independent areas, and the center line of each spacer 400 is arranged on the outer surface of the heat conductor 100 along the same bus bar. On the bus bar, the heat generating layers 200 are printed on the heat conductor 100 at intervals, and when the amount of heat generation is reduced, a certain amount of heat generation remains.

In this embodiment, the thick film heater may be connected to an external water supply circuit, and the thick film heater may be arranged horizontally or obliquely. The water flow enters from one side of the thick film heater and then exits from the other side. When the flow rate of the water flow is sufficient, the water flow fills the heating channel 300 in the whole thick film heater; when the flow rate of the water flow is insufficient, the water flow cannot fill the whole heating channel 300 in the thick film heater, and at this time, the water amount in the heating channel 300 covers the downward part and the upper part forms a hollow part under the action of gravity. The smaller the flow rate of the water flow, the larger the space of the hollow part, and correspondingly the larger the area of the inner wall which is not covered by the water flow, and the more serious the dry burning of the thick film heater.

It will be appreciated that to prevent dry-fire and related failure, the thick film heater needs to be positioned such that the spacer 400 is most susceptible to dry-fire when it is deployed. The arrangement of the thick film heater includes an inclined and horizontal arrangement. Wherein, when the thick film heater is arranged in an inclined manner, the position in the thick film heater where dry burning is most likely to occur is the upper surface of the higher end of the heat conductor 100; in the horizontal arrangement, the location in the thick film heater where dry burning is most likely to occur is the upper surface of the entire section of the thermal conductor 100.

When the thick film heater is obliquely arranged, the spacer 400 is arranged toward the upper side means that the spacer 400 is positioned on the upper surface of the higher end of the heat conductor 100 and arranged toward the upper side of the thick film heater. When the thick film heater is obliquely horizontally arranged, the spacer 400 is arranged toward the upper side means that the spacer 400 is arranged toward the upper side of the thick film heater. As such, the spacer 400 is located on top of the thermal conductor 100. The top of the heating channel 300 is not covered by the media when the media is not sufficient, but the thick film heater does not dry fire when the media is not sufficient because the top spacers 400 do not generate heat.

According to the thick film heater of the embodiment of the present application, the heat generating layer 200 does not completely cover the surface of the thick film heater. And the area which is not covered by the heating layer 200 is arranged upwards, so that when the thick film heater is used, the part facing upwards equipment does not generate heat, and when the medium is not enough to completely cover the thick film heater, the area which does not generate heat is arranged in the uncovered part, and the overheating caused by dry burning is avoided.

Referring to fig. 1, in some embodiments of the present application, the spacers 400 are uniformly arranged in the axial direction, and make the entire section of the heat generating layer 200 discontinuous in the circumferential direction.

In the present embodiment, the number of the spacers 400 is one. The whole section of the heat generating layer 200 refers to the whole printing section, the heat generating layer 200 is discontinuous in the circumferential direction at each position of the printing section, and two ends of the formed spacer 400 extend to the reserved sections 500 at two ends of the heat conductor 100. The thick film heater may be arranged in a horizontal arrangement with the centre line of the spacers 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 dry burning is avoided since the spacer 400 does not generate heat.

According to the thick film heater of the embodiment of the application, the heating layer 200 is uniformly printed along the axial direction of the heat conductor 100, and the blank end is reserved in the circumferential direction, so that the interval area 400 is uniformly distributed, and the printing of the heating layer 200 is simpler.

In some embodiments of the present application, the area of the spacers 400 accounts for 5% to 15% of the area of the outer surface of the thermal conductor 100.

In the present 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.

It will be appreciated that the provision of the spacer 400 results in a reduction in the maximum heat generation of the thick film heater, and that the larger the area of the spacer 400, the lower the maximum heat generation of the thick film heater, and the less the area of the spacer 400 is occupied. The heating performance of the thick film heater is prevented from being influenced by the arrangement of the spacer region 400 by setting the area of the spacer region 400 to be 5% -15% of the area of the outer surface of the heat conductor 100.

In some embodiments, the area of the spacers is 7% of the area of the outer surface of the thermal conductor.

According to the thick film heater of this application embodiment, through setting up 7% of the area of interval 400 area account for the external surface area of heat conductor 100, when avoiding thick film heater dry combustion, guaranteed that thick film heater has sufficient heating performance.

Referring to fig. 2, in some embodiments of the present application, the thick film heater may further include a delivery shaft 600. The conveying shaft 600 is disposed in the heat conductor 100, and the conveying shaft 600 is formed with a spiral sheet 610 along the axial direction, and the spiral sheet 610 is configured to cooperate with the inner wall of the heating channel 300 to form a spiral channel.

It should be noted that, after the conveying shaft 600 is disposed in the heat conductor 100, the original heating passage 300 is replaced by a spiral passage. After entering the heat conductor 100, the medium flows along a spiral channel. Compared with a straight heating channel, the spiral channel increases the surface area of water flow, and therefore the water heating efficiency is improved under the condition that the heating power and the heating size of the heating pipe are not changed.

It should be noted that, in order to facilitate the loading and unloading of the feeding shaft 600 into and from the heating channel 30 and 300, a certain interval may be provided between the outer diameter of the spiral piece 610 and the inner wall of the heating channel 300. Meanwhile, the interval is not too large to ensure that the water flow flows according to the spiral channel. In some embodiments, the outer diameter of the spiral sheet 610 may be 0.5 to 1.5mm narrower than the diameter of the heating channel 300.

In some embodiments, the outer diameter of the spiral piece 610 may be narrower than the diameter of the heating channel 300 by 0.5mm, which reduces the flow rate of the water flowing linearly along the axial direction of the thick film heater in the gap between the spiral piece 610 and the inner wall of the heating channel 300, so that the water can flow in the spiral channel, and the heating effect is improved.

In the present embodiment, the length L of the spiral sheet 610 may be equal to the axial length of the heat generating 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, and the overall flow rate of the water flow is reduced. If the length of the spiral piece 610 is too short, the flow rate of the water flow in the two ends of the heating channel 300 is large, and the heating effect is poor. Therefore, in the case where the length of the spiral pieces 610 may be equal to the axial length of the heat generating layer 200, the water flow can be heated most efficiently with less influence on the flow rate.

It will be appreciated that the thickness of the spiral sheet 610 is too thick, which reduces the space for the spiral channels and thus reduces the heating effect of the thick film heater. Therefore, the thickness of the spiral piece 610 may be as thin as possible while securing the strength. In some embodiments, the thickness of the spiral sheet 610 may be 0.8mm to 3mm, such as 1.2mm.

In some embodiments, the conveying shaft 600 is further formed with sealing parts 620 at both ends of the spiral piece 610, and through holes 621 are formed on the sealing parts 620, the through holes 621 being identical to the spiral passage. The sealing part 620 closes the heating passage 300 at both ends of the spiral piece 610 so that the spiral passage communicates with the outside space through the through hole 621. The through holes 621 at both ends can be used as water inlets or water outlets of the spiral channel.

According to the thick film heater of the embodiment of the application, the medium is conveyed in the thick film heater by utilizing the spiral channel, so that the medium is uniformly heated, and the heating efficiency of the thick film heater is improved.

In some embodiments of the present application, the helical pitch at both ends of the flight 610 is greater than the helical pitch at the middle section.

Referring to fig. 2, it should be noted that the pitch of the two ends of the spiral piece 610 refers to a first distance L1 between the connection surface of the through hole 621 and the spiral channel and the opposite spiral blade, and the pitch of the middle section of the spiral piece 610 is a second distance L2 between two adjacent spiral blades. Meanwhile, since the flight 610 is continuous, the pitch of the spirals at both ends of the flight 610 gradually decreases as it approaches the middle section.

It will be appreciated that the cross-sectional area of the spiral channel is small compared to the cross-sectional area of the external flume, and thus, when water flows into the spiral channel from the external flume or flows out of the spiral flume to the external flume, the water flow may be obstructed due to the abrupt narrowing of the flume. Wherein the cross-sectional area of the spiral channel refers to the area of the cross-section along the channel direction perpendicular to the spiral channel. The spiral space through making flight 610 both ends is greater than the spiral space of middle section, has increased the rivers flow space at spiral water course both ends to reduced rivers and got into spiral passage or flowed out the sudden change of flow when outside water course from outside water course, made rivers more smooth.

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 heat generating layer 200 is 1:3 to 1:8.

when the length of the spiral piece 610 is constant, the larger the ratio of the spiral pitch of the middle section of the spiral piece 610 to the axial length of the heat generating layer is, the longer the length of the spiral passage is, but the longer the spiral passage is, the water passage may be blocked. The smaller the ratio of the pitch of the spirals in the middle section of spiral piece 610 to the axial length of the heat generating layer, the shorter the length of the spiral channel, but too short a spiral channel may cause water to flow through the thick film heater too quickly, resulting in less efficient heating.

In some embodiments, the ratio of the pitch of the spirals in the middle section of the spiral sheet 610 to the axial length of the heat generating layer may be determined according to the heat generating power of the heat generating layer 200. When the heating power of the heating layer 200 is high, a short spiral channel can be set, that is, the ratio of the spiral distance of the middle section of the spiral piece 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 may be provided, i.e. the ratio of the spiral distance in the middle section of the spiral sheet 610 to the axial length of the heating layer is larger.

In some embodiments, the ratio of the pitch of the spirals in the middle section of the spiral 610 pieces to the axial length of the heat generating layer 200 is 1:7.

according to the thick film heater of this application embodiment, helical passage's length is moderate, and rivers are difficult to take place to block up when through helical passage, and rivers also can obtain abundant heating in helical passage simultaneously, have improved thick film heater's heating effect.

Referring to fig. 3, in some embodiments of the present application, the heat generating 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 temperature controller 710 is arranged on a control loop of the heating circuit, is disconnected when the temperature of the heating circuit is greater than or equal to a first temperature threshold value, and is restored when the temperature of the heating circuit is less than the first temperature threshold value; the second thermostat 720 is disposed on the control loop of the heating circuit, and is connected in series with the first thermostat 710, and is turned off when the temperature of the heating circuit is greater than or equal to a second temperature threshold.

It will be appreciated that the heating circuit may be a resistor with a trace. The heating circuit receives the driving current of the control unit and heats. The control unit may adjust the temperature of the heat generating circuit by adjusting a current value of the driving current. The temperature of the heat generating circuit can be determined by detecting the surface temperature of the heat generating layer 200. The control loop of the heating circuit refers to a connection loop of the control unit and the heating circuit, and the control unit transmits driving current to the heating circuit through the control loop.

The on/off of the control loop is controlled 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 turned off, the heating circuit cannot receive the driving current, the heating is stopped, and the temperature gradually decreases. When the first thermostat 710 or the second thermostat 720 are both in a connected state, the control circuit is connected, the heating circuit receives the driving current to generate heat, and the temperature is increased or kept constant.

It should be noted that the first thermostat 710 is a temperature controller capable of being recovered, that is, when the temperature of the heating circuit changes from a state greater than or equal to the first temperature threshold to a state less than the first temperature threshold, the first thermostat 710 can automatically recover from the off state to the on state. The second thermostat 720 is an unrecoverable thermostat, that is, when the temperature of the heating circuit changes from a state of being greater than or equal to the second temperature threshold to a state of being less than the second temperature threshold, the second thermostat 720 still keeps an off state. The first threshold and the second threshold range from 165 ℃ to 200 ℃, and the second threshold is greater than the first threshold, for example, the second threshold is 175 ℃ and the first threshold is 170 ℃.

According to the thick film heater of this application embodiment, through setting up a recoverable temperature controller and an unrecoverable temperature controller, detect the surface temperature under the thick film heater operating condition, the temperature controller of two-stage can make thick film heater have certain temperature regulation ability, reduces the temperature when the temperature is slightly high automatically, and stops to generate heat the disconnection protection when the temperature is too high to prevent thick film heater overheated dry combustion method.

In some embodiments of the present application, the thick film heater may further comprise a first temperature sensor 810 and a second temperature sensor 820 and a control unit. A first temperature sensor 810 for sensing a first temperature of fluid flowing into the thick film heater; a second temperature sensor 820 for sensing a second temperature of the fluid exiting the thick film heater; the control unit is electrically connected to the first temperature sensor 810, the first temperature sensor 820 and the heating circuit, respectively, for controlling the heating circuit according to the first temperature and the second temperature.

It will be appreciated that the thick film heater operates by heating the medium to a target temperature. The target temperature may be a user-entered temperature or a control unit for the thick film heater may be determined according to an internally-operating program. The first temperature is the temperature before the medium is heated, the second temperature is the temperature after the medium is heated, and the heating circuit can be controlled to operate at the proper heating power according to the first difference between the first temperature and the target temperature and the second difference between the second temperature and the target temperature. The heating power corresponding to the first difference and the second difference can be set as required, and the driving of the heating circuit has a mature technology, which is not described herein again in this embodiment.

According to the thick film heater of this application embodiment, detect the temperature before setting up temperature sensor to the medium heating and the temperature after the medium heating to according to testing result control heating circuit, thereby be convenient for adjust heating circuit's heating power, with heating the medium to target temperature.

In some embodiments, the thick film heater may further include a protective case 900. The protective shell 900 is disposed on the heat conductor 100 to isolate the heat conductor 100 from the outside, thereby preventing other components or users from contacting the surface of the heat conductor 100. The thick film heater is usually one of the components in the device, and the two ends of the protective shell 900 at the upper side may further be provided with mounting holes 910, and the mounting holes 910 may facilitate the installation of the thick film heater in the device. Meanwhile, the protective shell 900 can also have a certain heat insulation effect, and the heat generated by the thick film heater is prevented from affecting other parts in the equipment.

In some embodiments, the first thermostat 710 and the second thermostat 720 may be mounted on the protective case 900. The thick film heater may further include a connecting member 1000, one end of the connecting member 1000 may be provided with a connecting hole 1001, the connecting hole 1001 may be used to connect with the first temperature controller 710 and the second temperature controller 720, and the other end of the connecting member 1000 is fixed to the protective case 900 or to a device where the thick film heater is located, thereby fixing the first temperature controller 710 and the second temperature controller 720.

In some embodiments, the thick film heater may further comprise an input mechanism 1100 and an output mechanism 1200 at two ends, the input mechanism 1100 having an input port 1101, the output mechanism 1200 having an output port 1201, both the input port 1101 and the output port 1201 communicating with the heating channel or the spiral channel to input and output the medium. The thick film heater may further include a sealing gasket 1300 (e.g., a waterproof gasket, etc.), and the sealing gasket 1300 is disposed between the input mechanism 1100 and the heat conductor 100 and between the output mechanism 1200 and the heat conductor 100 to prevent the medium from leaking.

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 protrude into the pipeline, contacting the medium. In this way, the accuracy of the detection of the temperature of the medium can be increased.

Referring to fig. 4, the present application further provides a heater. The heater includes a heat conductor 100 and a heat generating layer 200. The heat conductor 100 is columnar and is formed with a through heating channel 300; the heat generating layer 200 is axially disposed on an outer surface of the heat conductor 100, the heat generating layer 200 includes a plurality of heat generating regions, heat generation amounts of the heat generating regions are different, and when the heater is operated by heating, a heat generating region having a smallest heat generation amount among the heat generating regions is arranged toward an upper side.

In this embodiment, the heat conductor 100 may be made of a metal material (such as copper), or a heat conducting material such as stainless steel. The heating channel 300 is used for conveying a medium, and when the medium passes through the heating channel 300, the heat conductor 100 transfers heat generated by the heat generating layer 200 to the medium, so that the medium is heated. The medium may be water or oil, and water is used as an example in the present embodiment.

In this embodiment, the heater is a thick film heater. The heat generating layer 200 may be a heating circuit formed using a screen printing technique, which may be formed by sequentially printing a dielectric layer and a resistive layer. The printing process of the heat generating layer 200 of the thick film heater is well-known in the art, and the detailed description of the embodiment is omitted.

In some embodiments, the thermal conductor 100 has a width at both ends, and a circumferential surrounding area is used as a reserved section 500, and the reserved section 500 is used for connecting with a waterway system. The heater needs to be connected with a waterway system, and if the two ends of the heater can be provided with a water inlet mechanism and a water outlet mechanism. Therefore, the reserved section 500 is arranged to be connected with the waterway system, and the waterway system is prevented from interfering with the heating layer 200. Between two reserved sections 500 on the heat conductor 100 is a printing section for printing the heat conductor 100.

In some embodiments, the resistive layer in the heat generating layer 200 is formed with resistive traces. The resistive traces within each heat generation area may have the same width and length, but the spacing between the resistive traces within each heat generation area is different, thereby forming different resistive trace distribution densities, which are performed to have different amounts of heat generation between the heat generation areas.

In some embodiments, the resistive traces within each heat generation area may be disposed at the same intervals, but the resistive traces within each heat generation area are different in width and length, such that the heat generation areas have different amounts of heat generation therebetween.

In the present embodiment, the heater may be connected to an external water supply circuit, and the heater may be disposed horizontally or obliquely. The water flow enters from one side of the heater and then exits from the other side. When the flow rate of the water flow is enough, the water flow fills the heating channel 300 in the whole heater; when the flow rate of the water is insufficient, the water cannot fill the heating passage 300 in the entire heater, and at this time, the water in the heating passage 300 covers the lower portion and the upper portion forms a hollow portion due to gravity. The smaller the flow rate of the water flow, the larger the space of the hollow portion, and correspondingly the larger the area of the inner wall which is not covered by the water flow, the more serious the dry burning of the heater.

It is understood that, in order to prevent dry burning, the heater needs to be disposed with the heat generation region having the smallest amount of heat generation at a position where dry burning is most likely to occur. Conventional arrangements of heaters include inclined and horizontal arrangements. Wherein, when the heater is arranged in an inclined manner, the position in the heater where dry burning is most likely to occur is the upper surface of the higher end of the heat conductor 100; in a horizontal arrangement, the position in the heater where dry burning is most likely to occur is the upper surface of the entire section of the heat conductor 100.

When the heater is obliquely arranged, the heat generation area having the smallest amount of heat generation is arranged toward the upper side means that the heat generation area having the smallest amount of heat generation is located on the upper surface of the higher end of the heat conductor 100 and is arranged toward the upper side of the heater. When the heater is arranged obliquely horizontally, the heat generation region having the smallest amount of heat generation is arranged toward the upper side means that the heat generation region having the smallest amount of heat generation is arranged toward the upper side of the heater. As such, the heat generating region having the smallest amount of heat generation is located on the top of the heat conductor 100. The top of the heating path 300 is not covered with the medium when the medium is insufficient, but the heater does not dry-fire when the medium is insufficient since the heat generation region of the top having the smallest amount of heat generation does not generate heat.

According to the heater, the heating layers are unevenly arranged on the outer surface of the heat conductor 100 to form a plurality of heating areas with different heating values, and the heating area with the smallest heating value faces upwards, so that when the heater is used, the heating value of the part facing upwards is lower, and when the medium is not enough to cover the heater, the heating value of the part which is not covered is lower, and the overheating caused by dry burning is avoided.

In some embodiments of the present application, the heat generation regions include a first heat generation region 210 and a second heat generation region 220, the first heat generation region 210 generates a smaller amount of heat than the second heat generation region 220, and the first heat generation regions 210 are uniformly arranged in the axial direction.

In the present embodiment, the heat generation layer 200 is divided into two heat generation regions, and the resistance track density in the first heat generation region 210 is smaller than the resistance track density in the second heat generation region 220, or the resistance track length or width in the first heat generation region 210 is smaller than the length or width of the second heat generation region 220.

The first heat generation regions 210 are uniformly arranged in the axial direction such that when the first heat generation regions 210 are arranged toward the upper side, the upper portion of the heater uniformly forms the heat generation region having a reduced amount of heat generation in the axial direction. When the medium is not sufficient to cover the heating channel, the uncovered area contains the first heating area 210 to the maximum extent, thereby avoiding dry burning. At the same time, printing of the heat generating layer 200 is also made simpler.

In some embodiments of the present application, the area of the first heat generation region 210 occupies 5% to 15% of the area of the heat generation layer 200.

It is understood that the arrangement of the first heat-generating region 210 may result in the maximum heat-generating amount of the heater being reduced, and the larger the area of the first heat-generating region 210 is, the lower the maximum heat-generating amount of the heater is, and the area ratio of the first heat-generating region 210 is not preferably too large. The heating performance of the heater is prevented from being affected by the arrangement of the first heat-generating region 210 by arranging that the area of the first heat-generating region 210 accounts for 5% -15% of the area of the heat-generating layer 200.

In some embodiments, the area of the first heat generating region 210 occupies 7% of the area of the heat generating layer 200.

According to the heater of the embodiment of the application, the area of the first heat-generating region 210 accounts for 7% of the area of the heat-generating layer 200, so that the heater is ensured to have enough heating performance while avoiding dry burning of the heater.

With continued reference to fig. 2, in some embodiments of the present application, the heater may further include a transport shaft 600. The conveying shaft 600 is disposed in the heat conductor 100, and the conveying shaft 600 is formed with a spiral sheet 610 along the axial direction, and the spiral sheet 610 is configured to cooperate with the inner wall of the heating channel 300 to form a spiral channel.

It should be noted that, after the conveying shaft 600 is disposed in the heat conductor 100, the original heating passage 300 is replaced by a spiral passage. After entering the heat conductor 100, the medium flows along a spiral channel. Compared with a straight-through heating channel, the spiral channel increases the surface area of water flow, and further improves the efficiency of water heating under the condition of not changing the heating power and size of the heating pipe.

It should be noted that, in order to facilitate the loading and unloading of the feeding shaft 600 into and from the heating channel 30 and 300, a certain interval may be provided between the outer diameter of the spiral piece 610 and the inner wall of the heating channel 300. Meanwhile, the interval should not be too large to ensure the water flow to flow according to the spiral channel. In some embodiments, the outer diameter of the spiral sheet 610 may be 0.5 to 1.5mm narrower than the diameter of the heating channel 300.

In some embodiments, the outer diameter of the spiral piece 610 may be narrower than the diameter of the heating channel 300 by 0.5mm, which reduces the flow rate of the water flowing linearly along the axial direction of the heater in the gap between the spiral piece 610 and the inner wall of the heating channel 300, so that the water can flow in the spiral channel, and the heating effect is improved.

In the present embodiment, the length L of the spiral sheet 610 may be equal to the axial length of the heat generating 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, and the overall flow rate of the water flow is reduced. If the length of the spiral piece 610 is too short, the flow rate of the water flow in the two ends of the heating channel 300 is large, and the heating effect is poor. Therefore, in the case where the length of the spiral sheet 610 may be equal to the axial length of the heat generating layer 200, the water flow can be heated most efficiently with less influence on the flow rate.

It will be appreciated that the thickness of the spiral sheet 610 is too thick, which reduces the space of the spiral passage, thereby reducing the heating effect of the heater. Therefore, the thickness of the spiral piece 610 may be as thin as possible while securing strength. In some embodiments, the thickness of the spiral sheet 610 may be 0.8mm to 3mm, such as 1.2mm.

In some embodiments, the conveying shaft 600 is further formed with sealing parts 620 at both ends of the spiral piece 610, and through holes 621 are formed on the sealing parts 620, the through holes 621 being identical to the spiral passage. The sealing part 800 closes the heating channel 300 at both ends of the spiral sheet 610 so that the spiral channel communicates with the outside space through the through hole 621. The through holes 621 at both ends can be used as water inlets or water outlets of the spiral channels.

According to the heater of this application embodiment, through utilizing helical passage to carry medium in the heater for the medium is by the equipartition heating, has improved the heating efficiency of heater.

Referring to fig. 2, it should be noted that the spiral pitch at both ends of the spiral piece 610 refers to a first distance L1 between a connection surface of the through hole 621 and the spiral channel and the opposite spiral blade, and the spiral pitch at the middle section of the spiral piece 610 is a second distance L2 between two adjacent spiral blades. Meanwhile, since the flight 610 is continuous, the pitch of the spirals at both ends of the flight 610 gradually decreases as it approaches the middle section.

It will be appreciated that the cross-sectional area of the spiral channel is small compared to the cross-sectional area of the external flume, and thus, when water flows into the spiral channel from the external flume or flows out of the spiral flume to the external flume, the water flow may be obstructed due to the abrupt narrowing of the flume. Wherein the cross-sectional area of the spiral channel refers to the area of the cross-section along the channel direction perpendicular to the spiral channel. The spiral space at the two ends of the spiral piece 610 is larger than that of the middle section, so that the fluid flowing spaces at the two ends of the spiral water channel are increased, the sudden change of the flow when water flows into the spiral channel from the external water channel or flows out of the spiral water channel to the external water channel is reduced, and the water flow is smoother.

when the length of the spiral piece 610 is constant, the larger the ratio of the spiral pitch of the middle section of the spiral piece 610 to the axial length of the heat generating layer is, the longer the length of the spiral passage is, but the longer the spiral passage is, the water passage may be blocked. The smaller the ratio of the spiral pitch of the middle section of the spiral sheet 610 to the axial length of the heat generating layer, the shorter the length of the spiral passage, but the too short spiral passage may cause the water to flow through the heater too fast, resulting in low heating efficiency.

In some embodiments, the ratio of the spiral pitch of the middle section of the spiral piece 610 to the axial length of the heat generating layer may be determined according to the heat generating power of the heat generating layer 200. When the heating power of the heating layer 200 is high, a short spiral channel can be set, that is, the ratio of the spiral distance of the middle section of the spiral piece 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 may be provided, i.e. the ratio of the spiral distance in the middle section of the spiral sheet 610 to the axial length of the heating layer is larger.

according to the heater of this application embodiment, helical passage's length is moderate, and rivers are difficult to take place to block up when through helical passage, and rivers also can obtain abundant heating in helical passage simultaneously, have improved the heating effect of heater.

Referring to fig. 5, in some embodiments of the present application, the heat generating 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 temperature controller 710 is arranged on a control loop of the heating circuit, is disconnected when the temperature of the heating circuit is greater than or equal to a first temperature threshold value, and is restored when the temperature of the heating circuit is less than the first temperature threshold value; the second thermostat 720 is disposed on the control loop of the heating circuit, and is connected in series with the first thermostat 710, and is turned off when the temperature of the heating circuit is greater than or equal to a second temperature threshold.

It will be appreciated that the heating circuit may be a resistor with a trace. The heating circuit receives the driving current of the control unit and generates heat. The control unit may adjust the temperature of the heat generating circuit by adjusting a current value of the driving current. The temperature of the heat generating circuit may be determined by detecting the surface temperature of the heat generating layer 200. The control loop of the heating circuit refers to a connection loop of the control unit and the heating circuit, and the control unit transmits driving current to the heating circuit through the control loop.

According to the heater of this application embodiment, through setting up a recoverable temperature controller and an unrecoverable temperature controller, detect the surface temperature under the heater operating condition, the temperature controller of two-stage can make the heater have certain temperature regulation ability, reduces the temperature when the temperature is slightly high automatically, and stops to generate heat when the temperature is too high and cuts off the protection to prevent the overheated dry combustion method of heater.

In some embodiments of the present application, the heater may further include first and

second temperature sensors

810 and 820 and a control unit. A first temperature sensor 810 for detecting a first temperature of the flow-through flowing into the heater; a second temperature sensor 820 for detecting a first temperature of the flow exiting the heater; the control unit is electrically connected to the first temperature sensor 810, the first temperature sensor 820 and the heating circuit, respectively, for controlling the heating circuit according to the first temperature and the second temperature.

It will be appreciated that the heater operates to heat the medium to a target temperature. The target temperature may be a temperature input by a user, or a control unit for the heater may be determined according to a program operated inside. The first temperature is the temperature before the medium is heated, the second temperature is the temperature after the medium is heated, and the heating circuit can be controlled to operate at the proper heating power according to the first difference between the first temperature and the target temperature and the second difference between the second temperature and the target temperature. The heating power corresponding to the first difference and the second difference can be set as required, and the driving of the heating circuit has a mature technology, which is not described herein again in this embodiment.

According to the heater of the embodiment of the application, the temperature sensor is arranged to detect the temperature of the medium before heating and the temperature of the medium after heating, and the heating circuit is controlled according to the detection result, so that the heating power of the heating circuit is convenient to adjust, and the medium is heated to the target temperature.

In some embodiments, the heater may further include a protective shell 900. The protective shell 900 is disposed on the heat conductor 100 to isolate the heat conductor 100 from the outside, thereby preventing other components or users from contacting the surface of the heat conductor 100. The heater is usually one of the components in the device, and both ends of the protective case 900 at the upper side may further be provided with mounting holes 910, and the mounting holes 910 may facilitate the installation of the heater into the device. Meanwhile, the protective shell 900 can have a certain heat insulation effect, and heat generated by the heater is prevented from affecting other components in the equipment.

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

In some embodiments, the heater may further comprise an input mechanism 1100 and an output mechanism 1200 at two ends, the input mechanism 1100 having an input port 1101, the output mechanism 1200 having an output port 1201, both the input port 1101 and the output port 1201 communicating with the heating channel or the spiral channel to input and output the medium. The heater may further include sealing gaskets 1300 (e.g., waterproof gaskets, etc.), and the sealing gaskets 1300 are disposed between the input mechanism 1100 and the heat conductor 100 and between the output mechanism 1200 and the heat conductor 100 to prevent the medium from leaking.

Embodiments of the present application also provide a heating apparatus comprising a thick film heater according to any one of the preceding embodiments or a heater according to any one of the preceding embodiments.

For the specific structure of the heater, reference may be made to the foregoing embodiments, and since the heating device in the embodiments of the present application may employ the heater in at least one of the foregoing embodiments, the heating device may have the technical effects in the foregoing embodiments, and details of this embodiment are not repeated herein.

An embodiment of the present application further provides a heating apparatus, and the heating apparatus includes: a water tank; and the main machine is connected with the water tank and is provided with a circulating water path, the main machine comprises the thick film heater according to any one of the previous embodiments or the heater according to any one of the previous embodiments, and the thick film heater or the heater is arranged on the circulating water path and is used for heating water flow in the circulating water path.

In some embodiments, the heating device may be a low-temperature slow cooker, the water pipe line of the circulation water path has an inlet connected to the water tank and an outlet connected to the water tank, and water in the water tank circulates through the circulation water path. The food is placed in a water tank, which contains a liquid. The main machine extracts water in the water tank, sends the water into the heater to be heated, and discharges the heated water back to the water tank, and the circulation is carried out to heat the water in the water tank to make the water reach the target temperature. The main machine heats the food in the water by heating the liquid.

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

In some embodiments, the heater in the slow cooker may be arranged horizontally or obliquely, so that the space 400 on the heat conductor 100 is arranged to face upward, and the heater may be placed for dry burning. In addition, the operation screen of the slow cooker is usually located above the heater, and if the heating value of the heater is too high, the screen may be overheated. In this embodiment, the spacers 400 on the heat conductor 100 are disposed to face upward, so that the amount of heat generated by the heater facing upward can be reduced, and overheating of the screen can be avoided.

The terms first, second and the like in the description and in the claims of the present application are used for distinguishing between similar elements and not necessarily for describing a particular sequential or chronological order. It will be appreciated that the data so used may be interchanged under appropriate circumstances such that embodiments of the application may be practiced in sequences other than those illustrated or described herein, and that the terms "first," "second," and the like are generally used herein in a generic sense and do not limit the number of terms, e.g., the first term can be one or more than one. In addition, "and/or" in the specification and claims means at least one of connected objects, a character "/", and generally means that the former and latter related objects are in an "or" relationship.

In the description of the present application, it is to be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "axial", "radial", "circumferential", and the like, indicate orientations and positional relationships based on the orientations and positional relationships shown in the drawings, and are used merely for convenience of description and for simplicity of description, and do not indicate or imply that the device or element being referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore, should not be considered as limiting the present application.

In the description of the present application, the first feature being "on" or "under" the second feature may include the first and second features being in direct contact, and may also include the first and second features being in contact not directly but via another feature therebetween.

In the description of the present application, the first feature being "on," "above" and "over" the second feature includes the first feature being directly above and obliquely above the second feature, or simply indicating that the first feature is at a higher level than the second feature.

Other configurations of heaters according to embodiments of the present application, such as heating circuits and sensors, and the like, and operation are known to those of ordinary skill in the art and will not be described in detail herein.

In the description herein, reference to the description of the terms "one embodiment," "some embodiments," "an illustrative embodiment," "an example," "a specific example," or "some examples" or the like means that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the application. In this specification, the schematic representations of the terms used above do not necessarily refer to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

While embodiments of the present application have been shown and described, it will be understood by those of ordinary skill in the art that: various changes, modifications, substitutions and alterations can be made to the embodiments without departing from the principles and spirit of the application, the scope of which is defined by the claims and their equivalents.

Claims

1. A thick film heater, comprising:

the heat conductor is columnar and is provided with a through heating channel;

the heating layer is arranged on the outer surface of the heat conductor along the axial direction, at least part of the heating layer is discontinuous in the circumferential direction to form a spacer area, and when the heater is in heating operation, the spacer area is arranged towards the upper side.

2. The thick film heater of claim 1, wherein the spacers are uniformly arranged in the axial direction and make the entire section of the heat generating layer circumferentially discontinuous.

3. The thick film heater of claim 2, wherein the spacer area comprises between 5% and 15% of the area of the outer surface of the thermal conductor.

4. The thick film heater of any one of claims 1-3, further comprising:

the conveying shaft is arranged in the heat conductor, a spiral sheet is formed on the conveying shaft along the axial direction, and the spiral sheet is used for being matched with the inner wall of the heating channel to form a spiral channel.

5. The thick film heater of claim 4, wherein the helical pitch at both ends of the helical sheet is greater than the helical pitch at the middle section.

6. The thick film heater of claim 5, wherein the ratio of the pitch of the spirals in the middle section of the spiral sheet to the axial length of the heat generating layer is 1:3 to 1:8.

7. the thick film heater of any one of claims 1-3, wherein the heat generating layer is formed with a heating circuit, the thick film heater further comprising:

the first temperature controller is arranged on a control loop of the heating circuit, is disconnected when the temperature of the heating circuit is greater than or equal to a first temperature threshold value, and is restored when the temperature of the heating circuit is less than the first temperature threshold value;

and the second temperature controller is arranged on the control loop of the heating circuit, is connected with the first temperature controller in series, and is disconnected when the temperature of the heating circuit is greater than or equal to a second temperature threshold value.

8. The thick film heater of claim 7, further comprising:

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 the control unit is respectively connected with the first temperature sensor, the first temperature sensor and the heating circuit and is used for controlling 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 is provided with a through heating channel;

the heating layer is arranged on the outer surface of the heat conductor along the axial direction and comprises a plurality of heating areas, the heating amount of each heating area is different, and when the heater is in heating operation, the heating area with the minimum heating amount in each heating area faces upwards.

10. The heater according to claim 9, wherein the plurality of heat generation regions include a first heat generation region and a second heat generation region, a heat generation amount of the first heat generation region is smaller than a heat generation amount of the second heat generation region, and the first heat generation regions are uniformly arranged in an axial direction.

11. A heating apparatus, characterised in that the heating apparatus comprises a thick film heater according to any one of claims 1 to 8 or a heater according to any one of claims 9 to 11.

12. A heating apparatus, characterized in that the heating apparatus comprises:

a water tank;

a main unit connected to the water tank and forming a circulation water path, the main unit comprising a thick film heater according to any one of claims 1 to 8 or a heater according to any one of claims 9 to 11, the thick film heater or the heater being provided on the circulation water path for heating a flow of water in the circulation water path.

13. A heating apparatus as claimed in claim 12, wherein the thick film heater or the heater is arranged at an angle to the vertical of greater than 0 degrees.