CN210328030U

CN210328030U - Surrounding type heating device, heating rod and liquid heater

Info

Publication number: CN210328030U
Application number: CN201920979989.3U
Authority: CN
Inventors: 宁子
Original assignee: Individual
Current assignee: Individual
Priority date: 2019-06-26
Filing date: 2019-06-26
Publication date: 2020-04-14
Anticipated expiration: 2029-06-26

Abstract

The utility model discloses a surrounding type heating device, which comprises an outer device tube, a heat conduction fixing seat distributed in the outer device tube for a circle, a PTC heating component arranged in the heat conduction fixing seat and a hollow inner supporting tube, wherein the cross section of the heat conduction fixing seat is arc-shaped, a fixing seat cavity is arranged in the heat conduction fixing seat, the PTC heating component is arranged in the fixing seat cavity, the inner supporting tube is arranged in an assembly space, and a lead of the PTC heating component is led out of the outer device tube from one end of the heat conduction fixing seat; the PTC heating assembly comprises two heating surfaces which are respectively opposite to the device outer tube and the inner supporting tube. The utility model also discloses a heating rod, liquid heater. Compared with the prior art, make PTC heating element both sides can be closely knit contact with device shell, interior stay tube, the heat reaches away more easily, improves the monolithic power of PTC, and the temperature that generates heat of each position of device shell is the same all, thereby realizes high efficiency even heating, improves the heating effect of liquid.

Description

Surrounding type heating device, heating rod and liquid heater

Technical Field

The utility model relates to a heating device, in particular to surrounding type heating device and heating rod, liquid heater.

Background

At present, an existing heating rod generally adopts an electric heating wire as a heating element, magnesium oxide powder with thermal conductivity is added into a pipe body to fill a space between the pipe body and the electric heating wire, and because the position of the electric heating wire in the pipe body is difficult to determine, temperature difference is easy to occur on the heating rod, namely, different positions of the pipe body have different heat, so that heating effect is uneven and poor, and the electric heating wire cannot be burnt in a dry state in use, so that the water level in a water tank or a liquid heater needs to be ensured to be capable of completely or partially soaking the heating rod all the time; if the situation of insufficient water supply occurs, the danger of explosion of the heating rod occurs, so that not only is fire easily caused, but also the personal safety is threatened. At present, the vast majority of the liquid flow channels of the existing PTC liquid heaters are made of aluminum profiles, the aluminum profiles can have the problem of corrosivity when used in liquid for a long time, the service life is short, the liquid flow channels are particularly used in the northern coal-to-electricity heating market, the medium heated by the heaters is water, the water quality difference of all areas is large, and the existing PTC heaters cannot meet the requirement of corrosion resistance. In addition, the existing PTC heater only has single-side through type heating, so that the heat efficiency is low, and the power is easy to attenuate.

SUMMERY OF THE UTILITY MODEL

An object of the utility model is to provide a surrounding type heating device and heating rod, liquid heater, the technical problem that solve are the thermal efficiency that improves the heating device and with low costs, security height moreover.

In order to solve the above problem, the utility model discloses a following technical scheme realizes: a surrounding type heating device comprises a hollow tubular device outer tube, a heat conduction fixing seat distributed in the device outer tube in a circle, a PTC heating assembly arranged in the heat conduction fixing seat and a hollow inner support tube, wherein the cross section of the heat conduction fixing seat is arc-shaped, the heat conduction fixing seats are multiple and are spliced with one another to form an annular shape so as to form an assembly space between the heat conduction fixing seats, a fixing seat cavity is formed in the heat conduction fixing seat, the PTC heating assembly is arranged in the fixing seat cavity, the inner support tube is arranged in the assembly space, the inner support tube is expanded through a stainless steel tube expanding process so as to tightly press and fix the PTC heating assembly and the heat conduction fixing seat between the device outer tube and the inner support tube, and a lead of the PTC heating assembly is led out of the device outer tube from one end of the heat conduction fixing seat; the PTC heating assembly comprises two heating surfaces which are opposite to the device outer tube and the inner supporting tube respectively so as to conduct heat to the device outer tube and the inner supporting tube through the heat conduction fixing seat.

Furthermore, one side edge of the heat conduction fixing seat is provided with a notch communicated with the fixing seat cavity, so that the PTC heating assembly is assembled and the heat conduction fixing seat can deform when being extruded, and the PTC heating assembly is compressed.

Furthermore, the opposite side edge of heat conduction fixing base and the breach position department of being relative is equipped with grafting portion, the one end that the fixed seat chamber was kept away from to the breach is equipped with the socket with grafting looks adaptation to make two adjacent heat conduction fixing bases 4 insert the socket through grafting portion and splice.

Furthermore, a fixing cavity groove extending towards the device outer tube direction is formed in the cavity of the fixing seat and close to the device outer tube, wherein the cavity wall of one end of the fixing seat cavity is opposite to the inserting part, and a compression deformation part is formed on the heat conduction fixing seat.

Further, the heat conduction fixing base includes a fixing base and a fixing base top cap, fixing base and the mutual joint of fixing base top cap, fixing base and the adjacent setting of interior support tube, fixing base top cap and the adjacent setting of device outer tube, a fixing base is the cambered surface of indent with the relative terminal surface of interior support tube, fixing base cavity is located fixing base and is served with the relative one of fixing base top cap, be equipped with the buckle that extends towards fixing base direction on the relative terminal surface of fixing base top cap and fixing base, be equipped with the draw-in groove with the corresponding department in buckle position on fixing base, realize that fixing base top cap and the mutual joint of fixing base are fixed.

Furthermore, be equipped with the exhibition arm on the fixing base top cap with the both ends that the buckle is adjacent, on every fixing base, be equipped with in one of them draw-in groove and stick out the arm of inserting outside the fixing base, form the inserting groove between the exhibition arm of another draw-in groove and this side, splice in inserting the inserting groove through inserting the arm between two adjacent heat conduction fixing bases.

Furthermore, a first deformation groove and a second deformation groove are respectively formed in two sides of one end, located on the inner supporting tube, of the fixed seat cavity and two sides of one end, opposite to the fixed seat cavity, of the fixed seat top cover.

The utility model also discloses a heating rod, include surrounding type heating device.

The utility model discloses still further disclose a liquid heater, include surrounding type heating device, the both ends of interior stay tube stretch out to the device outside the tube, the both ends of interior stay tube are the inlet outlet with the lumen intercommunication of interior stay tube to make liquid from the inlet outlet of interior stay tube one end advance the lumen of interior stay tube and flow from the inlet outlet of the other end, and heat the liquid in the support tube lumen in getting into.

The utility model further discloses a liquid heater, which comprises an outer tube body and the surrounding heating device, wherein the outer tube body is of a hollow structure, one end of the outer tube body is a closed surface, the other end of the outer tube body is a tube body opening communicated with the tube cavity of the outer tube body, the surrounding heating device is inserted into the outer tube body from the tube body opening, the surrounding heating device and the outer tube body are arranged on the same straight line, a flow passage is arranged between the surrounding heating device and the outer tube body, one end of the tube wall of the outer tube body, which is positioned at the tube body opening, is provided with a joint pipe communicated with the flow passage, two ends of the inner supporting tube all extend out of the device outer tube body, two ends of the inner supporting tube are respectively provided with a first inlet and a second outlet communicated with the tube cavity of the inner supporting tube, the tube body opening is provided with a cover plate hermetically connected, the cover plate seals the opening of the pipe body, a first through hole for the pipe body of the inner supporting pipe to extend out is arranged on the cover plate, one end of the inner supporting pipe, which is provided with a second inlet and a second outlet, extends out of the outer pipe body from the first through hole, and the first through hole is hermetically connected with the pipe body of the inner supporting pipe to prevent water from overflowing; liquid enters the inner supporting tube from the second inlet and outlet to be heated for the first time and enters the flow passage from the first inlet and outlet to be heated for the second time and then flows out from the joint tube or liquid enters the flow passage from the joint tube to be heated for the first time and enters the inner supporting tube from the first inlet and outlet to be heated for the second time and then flows out from the second inlet and outlet, so that the secondary heating of the liquid is realized.

Compared with the prior art, the utility model, set up a tubulose device shell, the annular distributes the heat conduction fixing base of a week in the device shell lumen, PTC heating element and hollow interior stay tube set up in heat conduction fixing base, adopt stainless steel expand tube technology in order to form the inflation portion on the interior stay tube through interior stay tube, realize compressing heat conduction fixing base and PTC heating element tightly and fixing between device shell and interior stay tube, make PTC heating element both sides can be closely knit and contact with device shell, interior stay tube, the heat passes away more easily, improve the monolithic power of PTC, the heating temperature of each position of device shell is the same, thereby realize high efficiency even heating, improve the heating effect of liquid; the heating surface of the PTC heating assembly is opposite to the device shell and the inner supporting tube, so that most of heat generated by the heater can be conducted into heated liquid, the heat efficiency is improved, and the energy is saved; will the utility model discloses a surrounding type heating device is arranged in liquid heater, with between device shell and the outer body and support the pipe in as heating container or piece as heating container in and to support the pipe as heating container to introduce liquid and heat, because PTC heating element's the face that generates heat is relative with device shell and interior support tube respectively, realize carrying out the even heating to liquid, and reduce the energy consumption.

Drawings

Fig. 1 is a schematic structural diagram of a circumferential heating device according to the present invention.

Fig. 2 is a schematic structural diagram of the wraparound heating device of the present invention.

Fig. 3 is a schematic structural view of the PTC heating assembly of the present invention.

Fig. 4 is a schematic view of a first structure of the heat-conducting fixing base of the present invention.

Fig. 5 is a schematic view of a second structure of the heat-conducting fixing base of the present invention.

Fig. 6 is a schematic structural view of the heating rod of the present invention.

Fig. 7 is a schematic structural view of the straight-through liquid heater of the present invention.

Fig. 8 is a schematic structural view of the liquid heater capable of secondary heating according to the present invention.

Detailed Description

The present invention will be described in further detail with reference to the accompanying drawings and examples.

As shown in fig. 1 and fig. 2, the utility model discloses a surrounding type heating device, which comprises a hollow tubular device outer tube 1, a heat conduction fixing seat 4 distributed in the device outer tube 1 for a circle, a PTC heating assembly 2 arranged in the heat conduction fixing seat 4 and a hollow inner support tube 3, wherein the device outer tube 1 can adopt a tube body with an opening at one end and a closed surface at the other end, and certainly can also adopt a tube body with openings at both ends; the inner supporting tube 3 is a tube body with openings at two ends, and the device outer tube 1 and the inner supporting tube 3 are arranged on the same straight line;

as shown in fig. 4, the heat conducting fixing seat 4 is arranged to extend along the axial direction of the device outer tube 1, the cross-sectional shape of the heat conducting fixing seat 4 is arc, a plurality of heat conducting fixing seats 4 are arranged to form a ring shape after being spliced with each other, so as to form an assembly space 5 between the heat conducting fixing seats 4 forming the ring shape, the center of the assembly space 5 and the axis of the device outer tube 1 are arranged on the same straight line, a fixing seat cavity 41 is arranged in the heat conducting fixing seat 4, the fixing seat cavity 41 is arranged along the length direction of the heat conducting fixing seat 4 and penetrates through two ends of the heat conducting fixing seat 4, the PTC heating assembly 2 is arranged in the fixing seat cavity 41, the inner support tube 3 is arranged in the assembly space 5, the inner support tube 3 is expanded by a stainless steel tube expansion process, so as to press and fix the PTC heating assembly 2 and the heat conducting fixing seat 4 between the device outer tube 1 and the inner, a lead 21 of the PTC heating assembly 2 is led out of the device outer tube 1 from one end of the heat-conducting fixed seat 4; as shown in fig. 3, the PTC heating assembly 2 includes two heating surfaces 22, and the two heating surfaces 22 are respectively opposite to the device outer tube 1 and the inner support tube 3 to conduct heat to the device outer tube 1 and the inner support tube 3 through the heat-conducting fixing base 4.

The utility model discloses in, device outer tube 1, interior stay tube 3 all adopt stainless steel material to make it can the rust-resistant, increase of service life, heat conduction fixing base 4 adopts aluminum alloy material to make, can carry out deformation slightly when carrying out the stainless steel expand tube technology with the realization.

As shown in fig. 3, the PTC heating element 2 of the present invention includes a plurality of sheet-shaped PTC heating elements 23, electrode sheets 24 and insulating paper 25, the PTC heating elements 23 are sequentially arranged along the length direction of the heat-conducting fixing base 4, the PTC heating elements 23 include two opposite surfaces and a circumference side, the two surfaces of the PTC heating elements 23 are heating surfaces 22, electrode coatings are coated on the two surfaces, two electrode sheets 24 are provided, which are respectively disposed on the two end surfaces of the PTC heating elements 23 and are in contact with the electrode coatings, two electrode sheets 24 are respectively provided with leads 21, one of the electrode sheets 24 is a positive electrode, the other electrode sheet 24 is a negative electrode, the two electrode sheets 24 clamp the PTC heating elements 23 therebetween to form a whole, and the insulating paper 25 is wound on the outer surface of the whole; the PTC heating element 23 is a ceramic PTC heating element, and both ends of the PTC heating assembly 2 are respectively filled with a sealant, thereby sealing the PTC heating assembly 2.

Example 1

As shown in fig. 4, the thermally conductive fixing base 4 can be implemented by the following structure: in the utility model, the structure and shape of each heat-conducting fixed seat 4 are the same, and one side of each heat-conducting fixed seat 4 opposite to the adjacent heat-conducting fixed seat 4 is provided with a notch 42 communicated with the fixed seat cavity 41, so as to facilitate the assembly of the PTC heating component 2 and ensure that the heat-conducting fixed seat 4 can deform when being extruded, thereby compressing the PTC heating component 2; specifically, the heat-conductive fixing base 4 includes a fixing base surface 401 opposite to the device outer tube 1 and the inner support tube 3, and a side surface 402 opposite to the adjacent heat-conductive fixing base 4, the two fixing base surfaces 401 form a heat-conductive surface to be opposite to the heat-generating surface 22 of the PTC heating assembly 2, and the notch 42 is provided on one of the side surfaces 402 and is provided along the length direction of the heat-conductive fixing base 4.

As shown in fig. 4, an insertion portion 43 is disposed on the other side of each heat-conducting fixed seat 4 opposite to the notch 42 and opposite to the notch 42, and a socket 44 adapted to the insertion portion 43 is disposed at one end of the notch 42 away from the fixed seat cavity 41, so that two adjacent heat-conducting fixed seats 4 are inserted into the socket 44 through the insertion portion 43 for splicing, and thus the heat-conducting fixed seats 4 are relatively limited for assembly; specifically, the insertion part 43 is disposed on the other side 402 opposite to the notch, the insertion part 43 is disposed along the length direction of the heat-conducting fixing base 4, and the notch 42, the socket 44 and the insertion part 43 are disposed at positions close to the fixing base surface 401 opposite to the device outer tube 1.

As shown in fig. 4, the cross-sectional shape of the insertion part 43 is crescent-shaped, and the recess is opposite to the insertion opening 44, and the insertion opening 44 is arc-shaped to match the outer shape of the insertion part 43.

As shown in fig. 4, on the basis of the above embodiment 1, a fixing cavity groove 45 extending toward the device outer tube 1 is formed in the fixing cavity 41 at the cavity wall at the end opposite to the insertion part 43 and adjacent to the device outer tube 1, so as to form a compressive deformation part 46 on the heat-conducting fixing seat 4, after the stainless steel tube expansion process is performed on the inner support tube 3, the inner support tube 3 extrudes the heat-conducting fixing seat 4, and the compressive deformation part 46 deforms in the extrusion process, so that the fixing cavity 41 deforms, the heating surface of the PTC heating assembly 2 is in close contact with the fixing cavity 41, and finally, the heat-conducting fixing seat 4 and the PTC heating assembly 2 are tightly pressed and fixed between the inner support tube 3 and the device outer tube 1.

Set up like this and to make heat conduction fixing base form a ring body of mutual interlock, the construction of being convenient for, every heat conduction fixing base sets to opening mode and easy to assemble PTC heating core, work efficiency is greatly improved, be favorable to at the inside and outside coating heat conduction silica gel of PTC heating element simultaneously, in addition, each position atress is even when more effectual solution hydraulic pressure expand tube, PTC heating element also can effectively receive the power of hydraulic pressure expand tube equally, thereby make PTC heating element and each parts zonulae occludens, thereby provide the heat conductivity rate.

Example 2

The heat-conducting fixing seat 4 can also be realized by adopting the following structure, as shown in fig. 5, in the present invention, the structure and shape of each heat-conducting fixing seat 4 are the same, the heat-conducting fixing seat 4 comprises a fixing seat base 47 and a fixing seat top cover 48, the fixing seat base 47 and the fixing seat top cover 48 are clamped with each other, the fixing seat base 47 is arranged adjacent to the inner supporting tube 3, the fixing seat top cover 48 is arranged adjacent to the device outer tube 1, one end surface of the fixing seat top cover 48 opposite to the device outer tube 1 is an outward convex cambered surface to form a heat-conducting surface to be tightly attached to the tube cavity of the device outer tube 1 after being pressed, one end surface of the fixing seat base 47 opposite to the inner supporting tube 3 is an inward cambered surface to form a heat-conducting surface to be tightly attached to the surface of the inner supporting tube 3 after being pressed, the fixing seat cavity, the two sides of one end face, opposite to the fixed seat base 47, of the fixed seat top cover 48 are symmetrically provided with buckles 481 extending towards the fixed seat base 47, and the positions, corresponding to the buckles 481, of the fixed seat base 47 are provided with clamping grooves 471, so that the fixed seat top cover 48 and the fixed seat base 47 are clamped and fixed with each other; specifically, the snap 481 is arranged along the length direction of the holder top cover 48, and the catch 471 is arranged along the length direction of the holder base 47.

As shown in fig. 5, the two ends of the fixing seat top cover 48 adjacent to the buckle 481 are provided with extending arms 482, on each fixing seat base 47, one of the slots 471 is provided with an inserting arm 472 protruding out of the fixing seat base 47, an inserting slot 49 is formed between the other slot 471 and the extending arm 482 at the side, and two adjacent heat-conducting fixing seats 4 are inserted into the inserting slot 49 through the inserting arm 472 for splicing; specifically, the extending arms 482 are parallel to the extending direction of the inserting arms 472, and after all the heat-conducting fixing bases 4 are spliced, each inserting arm 472 is just inserted into the inserting groove 49 at the corresponding position.

As shown in fig. 5, on the basis of the above embodiment 2, the first deforming groove 473 and the second deforming groove 483 are respectively disposed on the two sides of the end of the inner support tube 3 of the fixing seat cavity 41 and the two sides of the end of the fixing seat top cover 48 opposite to the fixing seat cavity 41, so that when the inner support tube 3 presses the heat-conducting fixing seat 4 after expanding, the fixing seat top cover 48 and the fixing seat base 47 deform, and the two heating surfaces 22 of the PTC heating assembly 2 are tightly contacted with the fixing seat top cover 48 and the fixing seat cavity 41.

As shown in fig. 6, the utility model also discloses a heating rod, including foretell surrounding type heating device, because the structure of surrounding type heating device has carried out detailed explanation in the foregoing, no longer repeated here, device outer tube 1 is as the shell of heating rod, the one end of device outer tube 1 is the closed surface 101, the other end is opening 102, and lead wire 21 is drawn forth from opening 102's one end, the one end outer wall that device outward appearance 1 is located opening 102 is equipped with a week bulge loop 103, and the cross section of bulge loop 103 is the T font, the utility model discloses a device outer tube 1 inserts in the water tank that device outer tube 1 is equipped with the one end of opening 102 and is located outside the water tank.

As shown in fig. 6, it is of course also possible to use an integrally formed structure of the outer tube 1 and the inner support tube 3 of the device.

As shown in fig. 7, the utility model also discloses a liquid heater, including foretell surrounding type heating device, because the structure of surrounding type heating device has carried out detailed explanation in the foregoing, no longer describe here, carry out detailed description to liquid heater's specific structure below, the both ends of interior stay tube 3 are stretched out outside device outer tube 1, the both ends of interior stay tube 3 are the inlet outlet 31 with the lumen intercommunication of interior stay tube 3 to make liquid advance into the lumen of interior stay tube 3 and flow out from the inlet outlet 31 of the other end from the inlet outlet 31 of interior stay tube 3 one end, and heat the liquid that gets into in the lumen of interior stay tube 3, be equipped with the external screw thread on the body outer wall that interior stay tube 3 stretches out device outer tube 1 both ends.

As shown in fig. 8, the present invention further discloses a liquid heater, which comprises an outer tube 200 and the above-mentioned surrounding heating device, wherein the outer tube 200 is a hollow structure, one end of the outer tube 200 is a closed surface 206, the other end is a tube opening 203 communicating with the tube cavity of the outer tube 200, the surrounding heating device 300 is inserted into the outer tube 200 from the tube opening 203, the surrounding heating device 300 and the outer tube 200 are arranged on the same straight line, a flow channel 201 is arranged between the surrounding heating device 300 and the outer tube 200, a connector 202 communicated with the flow channel 201 is arranged at one end of the tube wall of the outer tube 200 and located at the tube opening 203, two ends of the inner support tube 3 extend out of the device 1, two ends of the inner support tube 3 are respectively provided with a first inlet and a second outlet 32 communicated with the tube cavity of the inner support tube 3, a cover plate 204 hermetically connected with the outer tube 200 by welding is arranged on the tube opening 203, the cover plate 204 seals the opening 203 of the tube body, the cover plate 204 is provided with a first through hole 205 for the tube body of the inner support tube 3 to extend out, of course, the cover plate 204 is also provided with a hole for the lead 21 to extend out, the hole and the lead 21 are sealed, the sealing can be realized by arranging a sealing ring, one end of the inner support tube 3 provided with the second inlet and outlet 33 extends out of the outer tube body 200 from the first through hole 205, and the first through hole 205 is welded with the outer tube 1 to realize sealing; the first port 32 is located in the lumen of the outer tube body 200; liquid enters the inner support tube 3 from the second inlet and outlet 33 to be heated for the first time and enters the flow passage 201 from the first inlet and outlet 32 to be heated for the second time, and then flows out of the joint tube 202, or the liquid enters the flow passage 201 from the joint tube 202 to be heated for the first time and enters the inner support tube 3 from the first inlet and outlet 32 to be heated for the second time, and then flows out of the second inlet and outlet 33, so that the secondary heating of the liquid is realized; specifically, the inner diameter of the outer tube 200 is larger than the outer diameter of the surrounding heating device to form a flow channel 201; the axis of the joint pipe 202 is perpendicular to the axis of the outer pipe body 200, and external threads are arranged on the outer pipe wall of the joint pipe 202; the outer wall of the tube body at the end of the inner support tube 3 provided with the second inlet and outlet 33 is provided with external threads.

As shown in fig. 8, the end of the inner support tube 3 opposite to the sealing surface 206 is abutted against the sealing surface 206, and the first port 32 is provided on the outer wall of the tube body of the outer tube 1 of the device extending from the inner support tube 3 toward the sealing surface 206; specifically, the first inlet/outlet 32 is distributed around the outer wall of the tube body of the inner support tube 3.

Adopt foretell liquid heater, can carry out the secondary heating to liquid, in the liquid heater of equal flow, the utility model discloses can realize the secondary heating, improve heating efficiency and heating effect.

The utility model aims at:

1. the ceramic PTC is used as a heat source for heating, is safer than an electric heating tube and other heating materials, and has high electrothermal conversion rate which can reach 99%.

2. The whole body of the flow channel is designed by stainless steel, so that the flow channel is corrosion-resistant and can reduce the generation of water scale.

3. The liquid is heated by the two sides of the PTC, so that the problem that the power of the liquid is attenuated due to large temperature difference when the liquid is heated by the single side of the PTC is effectively solved, in addition, the power of the PTC single chip is improved, and the high-efficiency thermal conductivity is realized.

4. The cost is reduced, and the cost is greatly reduced compared with that of a red copper runner by adopting a stainless steel runner. The corrosion resistance is greatly improved.

Claims

1. A wrap-around heating device, comprising: the device comprises a hollow tubular device outer tube (1), heat conduction fixing seats (4) distributed in the device outer tube (1) for a circle, PTC heating components (2) arranged in the heat conduction fixing seats (4) and a hollow inner supporting tube (3), wherein the heat conduction fixing seats (4) are arc-shaped in cross section, a plurality of heat conduction fixing seats (4) are spliced with one another to form an annular shape so as to form an assembly space (5) between the heat conduction fixing seats (4), a fixing seat cavity (41) is arranged in each heat conduction fixing seat (4), the PTC heating components (2) are arranged in the fixing seat cavities (41), the inner supporting tube (3) is arranged in the assembly space (5), the inner supporting tube (3) is expanded through a stainless steel tube expanding process so as to tightly press and fix the PTC heating components (2) and the heat conduction fixing seats (4) between the device outer tube (1) and the inner supporting tube (3), a lead (21) of the PTC heating assembly (2) is led out of the device outer tube (1) from one end of the heat-conducting fixing seat (4); the PTC heating assembly (2) comprises two heating surfaces (22), wherein the two heating surfaces (22) are respectively opposite to the device outer tube (1) and the inner supporting tube (3) so as to conduct heat to the device outer tube (1) and the inner supporting tube (3) through the heat conducting fixing seat (4).

2. The wrap-around heating device of claim 1, wherein: one of them side of heat conduction fixing base (4) is equipped with breach (42) with fixed seat chamber (41) intercommunication to the assembly of PTC heating element (2) and make heat conduction fixing base (4) can take place deformation when being extruded, thereby compress tightly PTC heating element (2).

3. The wrap-around heating device of claim 2, wherein: the other side edge of the heat-conducting fixed seat (4) is provided with an inserting part (43) opposite to the position of the notch (42), and one end of the notch (42) far away from the fixed seat cavity (41) is provided with a socket (44) matched with the inserting part (43), so that two adjacent heat-conducting fixed seats (4) are inserted into the socket (44) through the inserting part (43) for splicing.

4. A wraparound heating device according to any one of claims 2 to 3, wherein: and a fixing cavity groove (45) extending towards the device outer tube (1) direction is formed in the cavity (41) of the fixing seat and at the cavity wall at one end opposite to the inserting part (43) and close to the device outer tube (1) so as to form a compression deformation part (46) on the heat-conducting fixing seat (4).

5. The wrap-around heating device of claim 1, wherein: the heat-conducting fixed seat (4) comprises a fixed seat base (47) and a fixed seat top cover (48), the fixed seat base (47) and the fixed seat top cover (48) are mutually clamped, the fixed seat base (47) is arranged adjacent to the inner supporting tube (3), the fixed seat top cover (48) is arranged adjacent to the device outer tube (1), one end surface of the fixed seat base (47) opposite to the inner supporting tube (3) is an inward concave cambered surface, the fixed seat cavity (41) is arranged at one end of the fixed seat base (47) opposite to the fixed seat top cover (48), a buckle (481) extending towards the direction of the fixed seat base (47) is arranged on one end surface of the fixed seat top cover (48) opposite to the fixed seat base (47), a clamping groove (471) is formed in the position, corresponding to the position of the buckle (481), of the fixing seat base (47), and the fixing seat top cover (48) and the fixing seat base (47) are clamped and fixed with each other.

6. The wrap-around heating device of claim 5, wherein: the heat-conducting fixing base is characterized in that the two ends, adjacent to the buckles (481), of the fixing base top cover (48) are provided with extension arms (482), each fixing base (47) is provided with an insertion arm (472) protruding out of the corresponding fixing base (47) in one clamping groove (471), an insertion groove (49) is formed between the other clamping groove (471) and the extension arm (482) on the side, and the two adjacent heat-conducting fixing bases (4) are spliced by inserting the insertion arms (472) into the insertion grooves (49).

7. The wrap-around heating device of claim 5 or 6, wherein: and a first deformation groove (473) and a second deformation groove (483) are respectively arranged on two sides of one end of the fixed seat cavity (41) positioned on the inner support tube (3) and two sides of one end of the fixed seat top cover (48) opposite to the fixed seat cavity (41).

8. A heating rod, characterized in that: comprising a wrap around heating device according to any of claims 1-7.

9. A liquid heater, comprising: comprising the wraparound heating device according to any one of claims 1 to 7, wherein both ends of the inner support tube (3) extend out of the outer tube (1) of the device, and both ends of the inner support tube (3) are water inlets and water outlets communicated with the tube cavity of the inner support tube (3), so that liquid enters the tube cavity of the inner support tube (3) from the water inlet and water outlet at one end of the inner support tube (3) and flows out from the water inlet and water outlet at the other end, and heats the liquid entering the tube cavity of the inner support tube (3).

10. A liquid heater, comprising: the device comprises an outer tube (200) and the surrounding type heating device as claimed in any one of claims 1 to 7, wherein the outer tube (200) is of a hollow structure, one end of the outer tube (200) is a closed surface (206), the other end of the outer tube is a tube opening (203) communicated with a tube cavity of the outer tube (200), the surrounding type heating device (300) is inserted into the outer tube (200) from the tube opening (203), the surrounding type heating device (300) and the outer tube (200) are arranged on the same straight line, a flow channel (201) is arranged between the surrounding type heating device (300) and the outer tube (200), a joint tube (202) communicated with the flow channel (201) is arranged at one end of the tube opening (203) on the tube wall of the outer tube (200), two ends of the inner support tube (3) both extend out of the outer tube (1), and two ends of the inner support tube (3) are respectively provided with a first inlet and a first outlet (32) communicated with the tube cavity of the inner support tube (3), A cover plate (204) which is connected with the outer pipe body (200) in a sealing manner in a welding manner is arranged on the pipe body opening (203), the pipe body opening (203) is sealed by the cover plate (204), a first through hole (205) for the pipe body of the inner supporting pipe (3) to extend out is arranged on the cover plate (204), one end of the inner supporting pipe (3) provided with a second inlet and outlet (33) extends out of the outer pipe body (200) from the first through hole (205), and the first through hole (205) is connected with the pipe body of the inner supporting pipe (3) in a sealing manner so as to prevent water from overflowing; liquid enters the inner supporting pipe (3) from the second inlet and outlet (33) to be heated for the first time and enters the flow channel (201) from the first inlet and outlet (32) to be heated for the second time and then flows out from the joint pipe (202) or liquid enters the flow channel (201) from the joint pipe (202) to be heated for the first time and enters the inner supporting pipe (3) from the first inlet and outlet (32) to be heated for the second time and then flows out from the second inlet and outlet (33), and secondary heating of the liquid is achieved.