Instant heater with anti-dry-burning structure

Abstract

The utility model discloses an instant heater with an anti-dry-burning structure, which comprises a shell provided with a liquid inlet and a liquid outlet. The electric heating tube is arranged in the shell, and a wiring end of the electric heating tube extends out of one end of the shell; the electric heating tube is sleeved with the heat conduction temperature sensing block, and the outer side face of the heat conduction temperature sensing block is partially or completely attached to the inner wall of the shell; the temperature limiter is connected to the outer wall of the shell in an attached mode through a support and is attached to the outer side face of the heat conduction temperature sensing block. Compared with the prior art, the electric heating tube is sleeved with the heat conduction temperature sensing block attached to the inner wall of the shell, the temperature limiter is connected to the outer wall of the shell in an attached mode and attached to the outer side face of the heat conduction temperature sensing block, and once the electric heating tube is subjected to dry burning, the surface temperature of a heating tube of the electric heating tube is rapidly conducted to the temperature limiter through the heat conduction temperature sensing block; and the temperature limiter immediately responds to trigger the power-off action of the electric heating tube, so that the electric heating tube is effectively prevented from being exploded and the heating wire is prevented from being burnt.

Description

Technical Field

[0001] The utility model relates to the technical field of liquid heaters, in particular to an instant heater with an anti-dry burning structure. Background Art

[0002] Instant electric heaters are used immediately without heat storage. The difference between the instant electric water heater standard GB4706.11 and the storage electric water heater standard GB4706.12 is that the former does not require energy efficiency rating testing while the latter must have energy efficiency testing standards. The core is that the electric heating efficiency of the former is unmatched by the latter. The trend of instant electric heaters being fully used in the fields of hot water supply, heating, boiling water and even steam in the corresponding complete machine has increased by orders of magnitude in the past decade, but while this type of product has played its advantages, it has also exposed safety defects, mainly focusing on the lack of reliability of the electric heating tube's anti-dry burning protection.

[0003] Figure 1 It is a conventional instant electric heater structure. Except for the difference in the number of electric heating tubes in the shell, there is basically no difference in the structural principle. Figure 1 Product structure diagram analysis reasons:

[0004] 1. When there is no water or lack of water, the heat conduction between the surface of the electric heating tube and the shell is only carried out in the form of heat radiation, and the amount of heat obtained on the shell is determined by the distance between the two. Even if the temperature value presented on the shell is greatly different from the temperature value of the electric heating tube, when the distance between the two is tried to be reduced as much as possible to increase the thermal response speed and promote the implementation of the intention of the temperature limiter, another problem will arise, that is, in normal use, the water flow will cause the electric heating tube and the shell to vibrate and cause knocking sound;

[0005] 2. The lack of water in the shell is caused by many factors: such as shell leakage, siphoning, and even reverse connection of the inlet and outlet, which lead to complete or semi-lack of water in the shell. These situations are difficult to effectively avoid through general structure or control. The corresponding national standard defines that the action of the temperature limiter under abnormal conditions is a necessary function. In fact, all faulty products have the following characteristics: even if the temperature limiter has been activated, the electric heating tube has been irreparably damaged. This feature further illustrates that the surface temperature of the electric heating tube is not only out of sync with the surface of the shell, but also has a huge time difference in lag. Because in this case, even if the electric heating tube has not exploded, the heating wire must have burned out, and the temperature of the worst grade iron-chromium-aluminum heating wire must be above 650°C, which can easily cause the electric heating tube to explode or the heating wire to burn out due to the slow reaction of the temperature limiter 3. Utility Model Content

[0006] The utility model aims to provide an instant heater with an anti-dry burning structure, aiming to solve the problem in the prior art that the slow reaction of the temperature limiter may cause the electric heating tube to burst or the heating wire to burn.

[0007] In order to achieve the above-mentioned purpose, the utility model provides an instant heater with an anti-dry-burning structure, including a shell, on which a liquid inlet and a liquid outlet are provided; an electric heating tube, which is arranged inside the shell, and the wiring terminal of the electric heating tube extends from one end of the shell; a thermally conductive temperature-sensing block, which is sleeved on the electric heating tube, and the outer side surface of the thermally conductive temperature-sensing block is partially or completely arranged to fit the inner wall of the shell; a temperature limiter, which is fit-connected to the outer wall of the shell through a bracket and is close to the outer side surface of the thermally conductive temperature-sensing block.

[0008] Furthermore, the shell and the thermally conductive temperature sensing block are fixedly connected via a supporting structure.

[0009] Furthermore, a protrusion is provided on the inner wall of the shell, and a recessed portion that cooperates and engages with the protrusion is provided on the outer surface of the thermally conductive temperature sensing block.

[0010] Furthermore, a liquid channel is provided on the thermally conductive temperature sensing block.

[0011] Furthermore, sealed end covers are provided at two opposite ends of the shell, and the connection end of the electric heating tube extends out of the sealed end cover at one end or the sealed end covers at both ends, and is sealed and fixedly connected to the sealed end covers.

[0012] Furthermore, the sealing end cover is connected to the end of the shell by welding.

[0013] Furthermore, the electric heating tube is any one of a single-head electric heating tube, a double-head electric heating tube, a U-shaped electric heating tube, an L-shaped electric heating tube and a W-shaped electric heating tube.

[0014] Furthermore, the heat-conducting temperature-sensing block is sleeved on the electric heating tube at a position close to the liquid outlet.

[0015] Furthermore, the liquid outlet is arranged close to the top of the shell in the vertical direction, and the liquid inlet is arranged close to the bottom of the shell in the vertical direction.

[0016] The instant heater with an anti-dry-burning structure provided by the utility model, compared with the prior art, is provided with a thermally conductive temperature-sensing block which is fitted with the inner wall of the shell on the electric heating tube, and the temperature limiter is fitted and connected to the outer wall of the shell and close to the outer side surface of the thermally conductive temperature-sensing block. Once the electric heating tube is dry-burned, the surface temperature of the heating tube is quickly transmitted to the temperature limiter through the thermally conductive temperature-sensing block, and the temperature limiter immediately reacts to trigger the power supply of the electric heating tube to shut down, thereby effectively protecting the electric heating tube from bursting and burning the heating wire. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a structural schematic diagram of a conventional instant electric heater in the prior art;

[0018] Figure 2 This is a schematic diagram of the structure of an instant heater with an anti-dry burning structure according to the utility model;

[0019] Figure 3 This is a schematic diagram of the internal structure of an instant heater with an anti-dry burning structure according to the utility model;

[0020] Figure 4 It is a structural schematic diagram of a heat-conducting temperature-sensing block in an instant heater with an anti-dry-burning structure according to the utility model;

[0021] Figure 5 This is a time measurement data chart of an instant heater with an anti-dry-burning structure according to the utility model from power-on to the action of a temperature limiter.

[0022] Description of Reference Numerals

[0023] 1-shell; 2-electric heating tube; 3-temperature limiter; 4-liquid inlet; 5-liquid outlet; 6-sealing end cover; 7-thermal conductive temperature sensing block; 8-liquid channel; 9-raised portion; 10-recessed portion. DETAILED DESCRIPTION

[0024] The present invention is described in detail below in conjunction with specific embodiments.

[0025] In the present utility model, when directional words appear, they are used to facilitate the description of the utility model and simplify the description, rather than to indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and cannot be understood as limiting the specific protection scope of the present utility model.

[0026] In the present invention, unless otherwise specified and limited, when terms such as "disposed on", "connected" and "connected" appear, these terms should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can also be a mechanical connection; it can be directly connected, or it can be connected through an intermediate medium, or the two elements can be internally connected. For those skilled in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0027] like Figure 2 As shown, an instant heater with an anti-dry burning structure includes a shell 1, an electric heating tube 2, a thermal conductive temperature sensing block 7 and a temperature limiter 3.

[0028] The shell 1 is made of stainless steel, and a liquid inlet 4 and a liquid outlet 5 are provided on the shell 1. The electric heating tube 2 is arranged inside the shell 1, and the terminal of the electric heating tube 2 extends from one end of the shell 1, and is insulated and sealed at its extended end by ceramic insulating particles. The thermal conductive temperature sensing block 7 is sleeved on the electric heating tube 2, and the outer side surface of the thermal conductive temperature sensing block 7 is partially or completely fitted with the inner wall of the shell 1, serving as a heat conduction element of the temperature limiter 3. The temperature limiter 3 is fitted and connected to the outer wall of the shell 1 through a bracket, and is close to the outer side surface of the thermal conductive temperature sensing block 7, so that the sudden high temperature generated by the shell 1 is quickly transferred to the temperature limiter 3 through the thermal conductive temperature sensing block 7 for rapid response, and the electric heating tube 2 is powered off through the controller, which effectively protects the electric heating tube 2 from bursting and burning the heating wire.

[0029] The material of the heat-conductive temperature sensing block 7 must be a metal material with good thermal conductivity and corrosion resistance, such as aluminum or copper, so that the heat can be quickly transferred to the temperature limiter 3 for sensing.

[0030] In this embodiment, the shell 1 and the thermally conductive temperature sensing block 7 are fixedly connected by a supporting structure to prevent the thermally conductive temperature sensing block 7 from sliding on the electric heating tube 2 and inside the shell 1 due to other factors such as vibration or looseness, so that the temperature limiter 3 can always receive heat conduction feedback from the thermally conductive temperature sensing block 7.

[0031] Specifically, a protrusion 9 is provided on the inner wall of the housing 1, and a recess 10 is provided on the outer surface of the thermal conductive temperature sensing block 7 to cooperate with the protrusion 9 to improve the connection stability of the thermal conductive temperature sensing block 7 inside the housing 1 and on the electric heating tube 2. The protrusion 9 and the recess 10 can be formed by one-time extrusion.

[0032] In this embodiment, a liquid channel 8 is provided on the heat-conducting temperature-sensing block 7, and the liquid channel 8 can be a hole of any shape.

[0033] In a specific implementation, the shell 1 can be a square column, a cylinder or a polygonal column. When the shell 1 is a cylinder and the thermal conductive temperature sensing block 7 is also a cylinder, the thermal conductive temperature sensing block 7 is sleeved on the electric heating tube 2 and the thermal conductive temperature sensing block 7 also contacts the inner wall of the shell 1. At this time, the entire outer peripheral surface of the thermal conductive temperature sensing block 7 must be in contact with the inner wall of the shell 1. Then, the liquid needs to pass through the liquid channel 8 and the thermal conductive temperature sensing block 7, otherwise the liquid cannot flow out from the liquid outlet 5.

[0034] In this embodiment, sealed end covers 6 are provided at two opposite ends of the shell 1, and the connection ends of the electric heating tubes 2 extend out of the sealed end covers 6 at one end or the sealed end covers 6 at both ends, and are sealed and fixedly connected to the sealed end covers 6, thereby preventing water in the shell 1 from leaking and contacting the power supply.

[0035] In addition, in order to ensure the sealing between the sealing end cover 6 and the end of the shell 1, the sealing end cover 6 and the end of the shell 1 are connected by welding.

[0036] In this embodiment, the electric heating tube 2 is any one of a single-ended electric heating tube 2 , a double-ended electric heating tube 2 , a U-shaped electric heating tube 2 , an L-shaped electric heating tube 2 and a W-shaped electric heating tube 2 .

[0037] In this embodiment, the thermal conductive temperature sensing block 7 is mounted on the electric heating tube 2 near the liquid outlet 5, so as to maximize the liquid level entering the shell 1, while also preventing the part of the electric heating tube 2 that is not in contact with the liquid from starting to dry burn after the liquid level drops.

[0038] In this embodiment, the liquid outlet 5 is arranged near the top of the shell 1 in the vertical direction, and the liquid inlet is arranged near the bottom of the shell 1 in the vertical direction, so that the liquid in the shell 1 can better cover the surface of the electric heating tube 2, fully heat the liquid, and avoid dry burning due to a small part of the electric heating tube 2 being unable to contact the liquid.

[0039] Compared with the prior art, the instant heater with an anti-dry-burning structure provided by the utility model is provided with a heat-conducting temperature-sensing block 7 which is arranged in close contact with the inner wall of the shell on the electric heating tube 2, and the temperature limiter 3 is connected in close contact with the outer wall of the shell 1 and is close to the outer side surface of the heat-conducting temperature-sensing block 7. Once the electric heating tube 2 is dry-burned, the surface temperature of the heating tube is quickly transmitted to the temperature limiter 3 through the heat-conducting temperature-sensing block 7, and the temperature limiter 3 immediately reacts to trigger the power off action of the electric heating tube 2, thereby effectively protecting the electric heating tube 2 from bursting and burning the heating wire.

[0040] The following is the actual test structure of the above structure:

[0041] Test 1

[0042] No. 1 is the manual reset type with the action point temperature of the temperature limiter 3 at 130℃ (CK201 type). The load of the electric heating tube 2 is 18W / Cm2. The distance between the electric heating tube 2 and the stainless steel cup is 5mm. The cup is in a state of complete water shortage. The time measurement value from power-on to the action of the temperature limiter 3 is as follows: Figure 4 shown.

[0043] No. 2 is a manual reset type with a temperature limiter 3 action point temperature of 130℃ (CK201 type), the load of the electric heating tube 2 is 18W / Cm2, the distance between the electric heating tube 2 and the stainless steel cup body is 5mm, but a heat-conducting temperature-sensitive aluminum block made of AL6063 material is added, and the shell 1 is also in a state of complete water shortage. The time measurement value from power-on to the action of the temperature limiter 3 is as follows: Figure 4 shown.

[0044] Test 2

[0045] No. 1 is the manual reset type with the action point temperature of the temperature limiter 3 at 130℃ (CK201 type). The load of the electric heating tube 2 is 15W / Cm2. The distance between the electric heating tube 2 and the stainless steel cup is 5mm. The cup is in a state of complete water shortage. The time measurement value from power-on to the action of the temperature limiter 3 is as follows: Figure 4 shown.

[0046] No. 2 is a manual reset type with a temperature limiter 3 action point temperature of 130℃ (CK201 type), the load of the electric heating tube 2 is 15W / Cm2, the distance between the electric heating tube 2 and the stainless steel cup body is 5mm, but a heat-conducting temperature-sensitive aluminum block made of AL6063 material is added, and the shell 1 is also in a state of complete water shortage. The time measurement value from power-on to the action of the temperature limiter 3 is as follows: Figure 4 shown.

[0047] Test Three

[0048] No. 1 is the manual reset type with the action point temperature of the temperature limiter 3 at 130℃ (CK201 type). The load of the electric heating tube 2 is 21W / Cm2. The distance between the electric heating tube 2 and the stainless steel cup is 5mm. The cup is in a state of complete water shortage. The time measurement value from power-on to the action of the temperature limiter 3 is as follows: Figure 4 shown.

[0049] No. 2 is a manual reset type with a temperature limiter 3 action point temperature of 130℃ (CK201 type). The load of the electric heating tube 2 is 21W / Cm2. The distance between the electric heating tube 2 and the stainless steel cup body is 5mm. However, a heat-conducting temperature-sensitive aluminum block made of AL6063 material is installed. The shell 1 is also in a state of complete water shortage. The time measurement value from power-on to the action of the temperature limiter 3 is as follows: Figure 4 shown.

[0050] Through the above three sets of tests, while adjusting the tube surface load of the electric heating tube 2 at the same time, the following conclusions can be drawn:

[0051] 1. After the heat-conducting temperature-sensing block 7 is installed on the electric heating tube 2, the heat can be quickly and effectively transferred out, which is significantly better than the transfer efficiency of the heat radiation on the surface of the electric heating tube 2;

[0052] 2. The thermal conductive temperature sensing block 7 and the housing 1 need to fit tightly together for a more obvious effect;

[0053] 3. The positions of the heat-conducting temperature sensing block 7, the housing 1 and the temperature limiter 3 must be consistent to effectively trigger the action of the temperature limiter 3;

[0054] 4. The thermal conductivity of the material of the thermal conductive temperature sensing block 7 also determines the speed of heat conduction.

[0055] In the absence of conflict, the above-mentioned embodiments and features thereof may be combined with each other.

[0056] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the utility model, rather than to limit the protection scope of the utility model. Although the utility model has been described in detail with reference to the preferred embodiments, ordinary technicians in this field should understand that the technical solution of the utility model can be modified or replaced by equivalents without departing from the essence and scope of the technical solution of the utility model.

Claims

1. An instant heater with an anti-dry burning structure, characterized in that: include: A shell, wherein the shell is provided with a liquid inlet and a liquid outlet; An electric heating pipe is arranged inside the shell, and a terminal of the electric heating pipe extends out from one end of the shell; A heat-conducting temperature-sensing block is sleeved on the electric heating tube, and a part or all of an outer side surface of the heat-conducting temperature-sensing block is arranged in contact with an inner wall of the shell; The temperature limiter is connected to the outer wall of the shell through a bracket and is close to the outer side surface of the heat-conducting temperature-sensing block.

2. The instant heater with an anti-dry burning structure according to claim 1, characterized in that: The shell and the heat-conductive temperature-sensing block are fixedly connected via a supporting structure.

3. The instant heater with anti-dry burning structure according to claim 2, characterized in that: A protrusion is provided on the inner wall of the shell, and a recessed portion which cooperates and engages with the protrusion is provided on the outer surface of the thermal conductive temperature sensing block.

4. The instant heater with an anti-dry burning structure according to claim 1 or 2, characterized in that: The heat-conducting temperature-sensing block is provided with a liquid channel.

5. The instant heater with anti-dry burning structure according to claim 1, characterized in that: Sealed end covers are provided at two opposite ends of the shell, and the connection end of the electric heating tube extends out of the sealed end cover at one end or the sealed end covers at both ends, and is sealed and fixedly connected with the sealed end covers.

6. The instant heater with anti-dry burning structure according to claim 5, characterized in that: The sealing end cover is connected to the end of the shell by welding.

7. The instant heater with an anti-dry burning structure according to claim 5, characterized in that: The electric heating tube is any one of a single-ended electric heating tube, a double-ended electric heating tube, a U-shaped electric heating tube, an L-shaped electric heating tube and a W-shaped electric heating tube.

8. The instant heater with anti-dry burning structure according to claim 1, characterized in that: The heat-conducting temperature-sensing block is sleeved on the electric heating tube at a position close to the liquid outlet.

9. The instant heater with an anti-dry burning structure according to claim 1, characterized in that: The liquid outlet is arranged close to the top of the shell in the vertical direction, and the liquid inlet is arranged close to the bottom of the shell in the vertical direction.

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