Quick heating type electric water heater

Abstract

The utility model discloses a quick-heating type electric water heater which comprises an inner container, a water outlet pipe, a first temperature sensor and a first electric heating pipe. The water outlet pipe is installed and fixed in the inner container, and the water inlet end of the water outlet pipe extends into the inner container and extends in the top direction of the inner container; one end of the first electric heating tube is fixedly connected to the inner container, and the other end of the first electric heating tube extends in the top direction of the inner container. And the first temperature sensor is detachably and fixedly connected to the outer wall of the inner container and is arranged close to the other end of the first electric heating pipe, and compared with an existing quick-heating type electric water heater, when the temperature or the temperature change rate of the wall face of the inner container close to the first electric heating pipe reaches a set value, the first electric heating pipe is started to heat the inner container. The controller of the water heater judges that the first electric heating tube is in the dry-burning state and controls the first electric heating tube to stop heating, so that the first electric heating tube is prevented from continuing dry-burning, compared with an existing quick-heating type water heater, the water heater is not affected by heating deformation of the water outlet pipe or faults of the flow sensor, the dry-burning prevention reliability is higher, and the use safety of a user is improved.

Description

Technical Field

[0001] The present application relates to the technical field of water heaters, and in particular to an instant electric water heater. Background Art

[0002] In the prior art, a storage-type electric water heater refers to a fixed appliance for heating water. It can store hot water for a long time or temporarily. It is easy to install and inexpensive, so it is loved by more and more users. However, a storage-type electric water heater needs to be heated for a long time and can only be used after reaching a certain temperature. Therefore, a storage-type electric water heater usually requires a long wait when using hot water. In order to reduce the waiting time, a quick-heating electric water heater has appeared on the market. By setting an electric heating tube, i.e., a quick-heating tube, on the top of the inner tank, the water on the top of the inner tank is centrally heated so that the outlet water temperature meets the use requirements. In order to make the outlet water temperature meet the use requirements, the surface heat load of the quick-heating tube is large. If the quick-heating tube is dry-burned, it is easy to burn out. Therefore, a flow sensor is set on the outlet pipe to detect the flow. When the user uses water, the flow sensor detects that there is water flow in the outlet pipe, and the quick-heating tube continues to heat. When the user stops using water, the flow sensor detects that there is no water flow in the outlet pipe, and the quick-heating tube stops heating. The above method prevents the quick-heating tube from being in a dry-burning state. However, when the water heater is used for a long time, the water outlet pipe is deformed due to heat, causing the water inlet of the water outlet pipe to be lower than the quick-heating tube. When the user uses water, part of the quick-heating tube is exposed above the water surface of the inner tank, or the flow sensor fails. The water heater controller believes that there is water flow in the water outlet pipe but no water in the inner tank. The quick-heating tube continues to work, resulting in dry burning. In severe cases, it may cause fire, reducing the user's safety. Utility Model Content

[0003] The technical problem solved by the utility model is to provide an instant electric water heater, which can judge whether the instant electric water heater is in a dry-burning state, thereby improving the safety of users.

[0004] The above technical problems are solved by the following technical solutions:

[0005] An instant electric water heater comprises: an inner tank, a water outlet pipe, a first temperature sensor and a first electric heating tube;

[0006] The water outlet pipe is installed and fixed to the inner pot, and its water inlet end extends into the inner pot and extends along the top direction of the inner pot; one end of the first electric heating tube is fixed to the inner pot, and the other end extends along the top direction of the inner pot; the first temperature sensor is detachably fixed to the outer wall of the inner pot, and is arranged close to the other end of the first electric heating tube.

[0007] The utility model provides a fast-heating electric water heater. When in use, the other end of the first electric heating tube centrally heats the hot water on the upper part of the inner tank, and the water flow flowing into the water outlet pipe has a better heating effect, which meets the user's instant water temperature requirement; at the same time, the first temperature sensor is detachably connected to the outer wall of the inner tank, that is, the temperature detection end of the first temperature sensor can better detect the wall temperature of the inner tank. When the other end of the first electric heating tube is separated from the water surface and dry-burning occurs, the first electric heating tube exchanges heat with the wall of the inner tank through heat convection and heat radiation. The temperature of the inner tank wall adjacent to the other end of the first electric heating tube rises rapidly, and the first temperature sensor The sensor is arranged close to the other end of the first electric heating tube, so the first temperature sensor can quickly detect the temperature of the inner tank wall adjacent to the other end of the first electric heating tube and can transmit the temperature signal to the controller of the water heater. When the temperature of the inner tank wall adjacent to the other end of the first electric heating tube or the temperature change rate reaches the set value, the controller of the water heater determines that the first electric heating tube is in a dry-burning state and controls the first electric heating tube to stop heating, thereby preventing the first electric heating tube from continuing to dry-burn. Compared with the existing instant heating water heaters, it is not affected by the thermal deformation of the water outlet pipe or the failure of the flow sensor, and the anti-dry-burning reliability is higher, thereby improving the user's safety.

[0008] In one embodiment, the other end of the first electric heating tube is arranged close to the water outlet end of the water outlet pipe.

[0009] In one embodiment, the instant electric water heater further comprises a heat collection cup with openings at both ends, the heat collection cup is fixedly mounted on the other end of the first electric heating tube, and is respectively sleeved on the other end of the first electric heating tube and the water outlet pipe.

[0010] In one embodiment, the temperature detection end of the first temperature sensor is in close contact with the outer wall of the inner pot, and at least a part of the temperature detection end of the first temperature sensor is located within the projection range of the inner pot on an end surface of the heat collecting cup.

[0011] In one embodiment, the instant electric water heater further includes a first threaded connector and a second threaded connector; the first threaded connector is fixedly connected to the outer wall of the inner tank, and the first threaded connector is threadedly connected to the second threaded connector so that the first temperature sensor can be removably fixed to the outer wall of the inner tank.

[0012] In one embodiment, the first threaded connection is a screw, which is fixed to the outer wall of the inner tank; the second threaded connection is a nut; the first temperature sensor is provided with a mounting end; the screw is threadedly connected to the nut so that the nut presses the mounting end against the outer wall of the inner tank.

[0013] In one embodiment, the first threaded connection is a nut, which is fixed to the outer wall of the inner tank; the second threaded connection is a screw; the first temperature sensor is provided with a mounting end; the screw is threadedly connected to the nut so that the screw presses the mounting end against the outer wall of the inner tank.

[0014] In one of the embodiments, the mounting end is provided with a mounting hole, and the screw rod is passed through the mounting hole and is threadedly connected with the nut.

[0015] In one embodiment, the instant electric water heater further comprises a heat-conducting sleeve, the outer wall of which is tightly fixed to the outer wall of the inner tank; the first temperature sensor is inserted and fixed to the heat-conducting sleeve so that the first temperature sensor can be removably fixed to the outer wall of the inner tank.

[0016] In one embodiment, the instant electric water heater further includes a controller, a second electric heating tube, a second temperature sensor and a temperature detection blind tube; one end of the second electric heating tube is fixedly connected to the inner tank, and the other end extends along the bottom direction of the inner tank; the temperature detection blind tube is fixedly connected to the inner tank and extends along the bottom direction of the inner tank, and the second temperature sensor is inserted in the temperature detection blind tube; the controller is electrically connected to the first electric heating tube, the second electric heating tube, the first temperature sensor and the second temperature sensor, respectively.

[0017] It should be understood that the content described in this section is not intended to identify the key or important features of the embodiments of the present application, nor is it intended to limit the scope of the present application. Other features of the present application will become easily understood through the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0019] Figure 1 It is a schematic cross-sectional structure diagram of an instant electric water heater provided by the present application;

[0020] Figure 2 It is a structural schematic diagram of a quick-heating electric water heater provided by the present application;

[0021] Figure 3 yes Figure 2 The enlarged structural diagram at A in the middle;

[0022] Figure 4It is a schematic diagram of the structure of a heating component of an instant electric water heater provided in the present application.

[0023] In the figure, the reference numerals are:

[0024] 1. Inner tank; 2. Water outlet pipe; 30. First temperature sensor; 300. Mounting end; 31. Second temperature sensor; 40. First electric heating tube; 400. Rapid heating section; 41. Second electric heating tube; 5. Heat collecting cup; 6. Screw; 7. Nut; 8. Temperature detection blind tube. DETAILED DESCRIPTION

[0025] In order to enable those skilled in the art to better understand the solution of the present application, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the present application.

[0026] In the description of the present invention, it should be understood that the terms "center", "upper", "lower" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific position, be constructed and operated in a specific position, and therefore cannot be understood as limiting the present invention.

[0027] Hereinafter, the terms "including", "having" and their cognates, which may be used in various embodiments of the present invention, are intended only to indicate specific features, numbers, steps, operations, elements, components or combinations of the foregoing items, and should not be understood as first excluding the existence of one or more other features, numbers, steps, operations, elements, components or combinations of the foregoing items or adding the possibility of one or more features, numbers, steps, operations, elements, components or combinations of the foregoing items.

[0028] Furthermore, the terms “first”, “second”, etc. are merely used for distinguishing descriptions and should not be understood as indicating or implying relative importance.

[0029] Unless otherwise defined, all terms (including technical terms and scientific terms) used herein have the same meanings as those generally understood by those skilled in the art to which the various embodiments of the present invention belong. The terms (such as those defined in generally used dictionaries) will be interpreted as having the same meanings as the contextual meanings in the relevant technical field and will not be interpreted as having idealized meanings or overly formal meanings unless clearly defined in the various embodiments of the present invention.

[0030] like Figure 1-3 As shown, in one embodiment, the utility model provides

[0031] An instant electric water heater, comprising: an inner tank 1, a water outlet pipe, a first temperature sensor 30 and a first electric heating tube 40;

[0032] The water outlet pipe is installed and fixed to the inner pot 1, and its water inlet end extends into the inner pot 1 and extends along the top direction of the inner pot 1; one end of the first electric heating tube 40 is fixed to the inner pot 1, and the other end extends along the top direction of the inner pot 1; the first temperature sensor 30 is detachably fixed to the outer wall of the inner pot 1, and is arranged close to the other end of the first electric heating tube 40.

[0033] On the basis of the above structure, when in use, the other end of the first electric heating tube 40 centrally heats the hot water on the upper part of the inner tank 1, and the water flow flowing into the water outlet pipe has a better heating effect, which meets the user's immediate water temperature requirements; at the same time, the first temperature sensor 30 is detachably fixed to the outer wall of the inner tank 1, that is, the temperature detection end of the first temperature sensor 30 can better detect the wall temperature of the inner tank 1. When the other end of the first electric heating tube 40 is separated from the water surface and dry-burned, the first electric heating tube 40 exchanges heat with the wall of the inner tank 1 through heat convection and heat radiation. The temperature of the wall of the inner tank 1 adjacent to the other end of the first electric heating tube 40 rises rapidly, and the first temperature sensor 30 and The other end of the first electric heating tube 40 is arranged close to it, so the first temperature sensor 30 can quickly detect the wall temperature of the inner tank 1 adjacent to the other end of the first electric heating tube 40 and can transmit the temperature signal to the controller of the water heater. When the wall temperature or the temperature change rate of the inner tank 1 adjacent to the other end of the first electric heating tube 40 reaches the set value, the controller of the water heater determines that the first electric heating tube 40 is in a dry-burning state and controls the first electric heating tube 40 to stop heating, thereby preventing the first electric heating tube 40 from continuing to dry-burn. Compared with the existing instant heating water heater, it is not affected by the thermal deformation of the water outlet pipe or the failure of the flow sensor, and the reliability of anti-dry-burning is higher, thereby improving the user's safety.

[0034] It can be understood that the first temperature sensor 30 is arranged close to the other end of the first electric heating tube 40, that is, the distance between the first temperature sensor 30 and the other end of the first electric heating tube 40 is less than the distance between the first temperature sensor 30 and one end of the first electric heating tube 40, so that the sensitivity of the first temperature sensor 30 to the temperature rise detection of the first electric heating tube 40 is improved to avoid the occurrence of dry burning. Among them, the distance between the first temperature sensor 30 and the other end of the first electric heating tube 40 should not be too large, otherwise the sensitivity of the first temperature sensor 30 to the temperature rise detection of the other end of the first electric heating tube 40 will be reduced. The distance between the first temperature sensor 30 and the other end of the first electric heating tube 40 can be determined according to the sensitivity requirements of the temperature rise detection of the other end of the first electric heating tube 40, and considering the distance requirements between the other end of the first temperature sensor 30 and the inner wall of the inner tank and the wall thickness of the inner tank, for example, the distance between the first temperature sensor 30 and the other end of the first electric heating tube 40 can be in the range of 2cm to 10cm to meet the temperature detection requirements.

[0035] In addition, the first temperature sensor 30 may be a temperature sensor with an existing structure or specification, and the structure or specification of the first temperature sensor 30 will not be described in detail herein.

[0036] It is worth mentioning that the first temperature sensor 30 is detachably fixedly connected to the outer wall of the inner liner 1. On the one hand, it ensures that the first temperature sensor 30 does not move when the insulation material is filled between the inner liner 1 and the outer shell, thereby ensuring the accuracy of the detection of the first temperature sensor 30. On the other hand, it is convenient to replace the first temperature sensor 30.

[0037] Optionally, in this embodiment, the other end of the first electric heating tube 40 is arranged close to the water outlet end of the water outlet pipe. Exemplarily, the other end of the first electric heating tube 40 is provided with a quick heating section 400 with a U-shaped bending structure, and the quick heating section 400 is arranged close to the water outlet end of the water outlet pipe; such a setting can better concentrate the heating of the water flow flowing into the water outlet pipe to meet the outlet water temperature requirement. In addition, the first temperature sensor 30 can more accurately detect the outlet water temperature, which is beneficial for the water heater controller to control the first electric heating tube 40 according to the outlet water temperature.

[0038] It can be understood that the quick heating section 400 is arranged close to the water inlet end of the water outlet pipe, that is, the distance between the quick heating section 400 and the water inlet end of the water outlet pipe is smaller than the distance between the quick heating section 400 and the water outlet end of the water outlet pipe. The distance between the quick heating section 400 and the water inlet end of the water outlet pipe should not be too large, otherwise the outlet water cannot be effectively heated. On the basis of a certain power of the first electric heating tube 40, the distance between the quick heating section 400 and the water inlet end of the water outlet pipe can be determined according to the outlet water temperature requirement, while taking into account the distance requirement between the other end of the first temperature sensor 30 and the water outlet pipe. By way of example, the distance between the quick heating section 400 and the water inlet end of the water outlet pipe can range from 2 cm to 5 cm to meet the outlet water temperature requirement.

[0039] In this embodiment, the instant electric water heater further includes a heat collection cup 5 with openings at both ends, wherein the heat collection cup 5 is installed and fixed to the other end of the first electric heating tube 40, and is respectively sleeved on the other end of the first electric heating tube 40 and the water outlet pipe; such arrangement enables the instant heating section 400 to better centrally heat the water flowing into the water outlet pipe to meet the outlet water temperature requirements.

[0040] Furthermore, in this embodiment, in order to improve the sensitivity of the first temperature sensor 30 to the temperature rise detection of the first electric heating tube 40, the temperature detection end of the first temperature sensor 30 is close to the outer wall of the inner pot 1, and the temperature detection end of the first temperature sensor 30 is at least partially located at one end face of the heat collection cup 5 within the projection range of the inner pot 1. In this way, the heat generated by the other end of the first electric heating tube 40 can be concentrated and transferred to the wall surface of the inner pot 1 through the end face of the heat collection cup 5. The first temperature sensor 30 can detect the temperature rise of the other end of the first electric heating tube 40 more quickly, thereby more quickly knowing whether the other end of the first electric heating tube 40 is in a dry burning state.

[0041] In this embodiment, the instant electric water heater further includes a first threaded connector and a second threaded connector; the first threaded connector is fixedly connected to the outer wall of the inner tank 1, and the second threaded connector is fixedly connected to the temperature sensor, and the first threaded connector and the second threaded connector are threadedly connected so that the first temperature sensor 30 can be removably fixed to the outer wall of the inner tank 1; such a configuration improves the convenience of assembly and disassembly between the first temperature sensor 30 and the inner tank 1.

[0042] It should be noted that the first threaded connection can be fixed to the outer wall of the inner tank 1 by welding, bonding, etc.; optionally, the second threaded connection can be fixed to the first temperature sensor 30 by welding, bonding, etc., and the first threaded connection is threadedly connected to the second threaded connection to fix the first temperature sensor 30 to the outer wall of the inner tank 1; or the first threaded connection is threadedly connected to the second threaded connection, and the second threaded connection presses the first temperature sensor 30 to the outer wall of the inner tank 1.

[0043] Furthermore, if Figure 3 As shown, in this embodiment, the first threaded connection member is a screw 6, and the screw 6 is fixedly connected to the outer wall of the inner tank 1; the second threaded connection member is a nut 7; the first temperature sensor 30 is provided with a mounting end 300; the screw 6 is threadedly connected to the nut 7 so that the nut 7 presses the mounting end 300 against the outer wall of the inner tank 1.

[0044] It should be noted that, in this embodiment, the screw rod 6 is fixed to the outer wall of the inner container 1 by welding.

[0045] Furthermore, in this embodiment, in order to more firmly fix the first temperature sensor 30 on the outer wall of the inner tank 1, in this embodiment, the mounting end 300 is provided with a mounting hole, and the screw 6 is passed through the mounting hole and threadedly connected with the nut 7.

[0046] Of course, in other embodiments, the first threaded connector is a nut 7, and the nut 7 is fixed to the outer wall of the inner container 1; the second threaded connector is a screw 6; the first temperature sensor 30 is provided with a mounting end 300; the screw 6 is threadedly connected to the nut 7 so that the screw 6 presses the mounting end 300 against the outer wall of the inner container 1;

[0047] Alternatively, in other embodiments, the instant water heater further comprises a heat-conducting sleeve, the outer wall of which is tightly fixed to the outer wall of the inner tank 1; the first temperature sensor 30 is inserted and fixed to the heat-conducting sleeve so that the first temperature sensor 30 can be removably fixed to the outer wall of the inner tank 1.

[0048] It should be noted that the heat-conducting sleeve is fixed to the outer wall of the inner tank 1 by welding, so that the heat-conducting performance is better; further, the heat-conducting sleeve can be made of some metal materials with excellent heat-conducting performance such as copper and aluminum.

[0049] In this embodiment, if Figure 4As shown, the instant heating water heater further includes a controller (not shown in the figure), a second electric heating tube 41, a second temperature sensor 31 and a temperature detection blind tube 8; one end of the second electric heating tube 41 is fixedly connected to the inner tank 1, and the other end extends along the bottom direction of the inner tank 1; the temperature detection blind tube 8 is fixedly connected to the inner tank 1 and extends along the bottom direction of the inner tank 1, and the second temperature sensor 31 is inserted in the temperature detection blind tube 8; the controller (not shown in the figure) is electrically connected to the first electric heating tube 40, the second electric heating tube 41, the first temperature sensor 30 and the second temperature sensor 31 respectively; in this way, when the water heater is working, the water with higher temperature is located at the top position of the inner tank 1, and the water with lower temperature is located at the bottom position of the inner tank 1. By setting the first temperature sensor 30 and the second temperature sensor 31, the hot water in the inner tank 1 is layered and temperature detected, and the controller (not shown in the figure) controls the operation of the first electric heating tube 40 and the second electric heating tube 41 according to the temperature information detected by the first temperature sensor 30 and the second temperature sensor 31, so as to meet the hot water output demand and reduce energy consumption.

[0050] Furthermore, the temperature detection blind tube 8 can be made of metal materials with excellent thermal conductivity such as copper and aluminum.

[0051] Exemplarily, when a user uses water, when the second temperature sensor 31 detects that the temperature at the bottom of the inner tank 1 is less than 60°C and the first temperature sensor 30 detects that the temperature at the top of the inner tank 1 is less than 80°C, the controller (not shown in the figure) controls the first electric heating tube 40 and the second electric heating tube 41 to work simultaneously; when the second temperature sensor 31 detects that the temperature at the bottom of the inner tank 1 is less than 60°C and the first temperature sensor 30 detects that the temperature at the top of the inner tank 1 is greater than or equal to 80°C, the controller (not shown in the figure) controls the first electric heating tube 40 to stop working and the second electric heating tube 41 to continue working; when the second temperature sensor 31 detects that the temperature at the bottom of the inner tank 1 is greater than or equal to 60°C and the first temperature sensor 30 detects that the temperature at the top of the inner tank 1 is less than 80°C, the controller (not shown in the figure) controls the first electric heating tube 40 to continue working and the second electric heating tube 41 to stop working. In this way, the user's hot water demand can be met while reducing the heat loss caused by excessive heating when the user is not using water and increasing energy consumption.

[0052] It should be noted that the controller (not shown in the figure), the second electric heating tube 41, and the second temperature sensor 31 can be mature products with existing structures or specifications. The structures or specifications of the controller (not shown in the figure), the second electric heating tube 41, and the second temperature sensor 31 are not described in detail here.

[0053] The embodiments of the present application provide the above specific implementation methods, which do not constitute a limitation on the protection scope of the present application. It should be understood by those skilled in the art that various modifications, combinations, sub-combinations and substitutions can be made according to design requirements and other factors. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present application should be included in the protection scope of the present application.

Claims

1. An instant electric water heater, characterized in that: include: Inner tank, water outlet pipe, first temperature sensor and first electric heating tube; The water outlet pipe is installed and fixed to the inner pot, and its water inlet end extends into the inner pot and extends along the top direction of the inner pot; one end of the first electric heating tube is fixed to the inner pot, and the other end extends along the top direction of the inner pot; the first temperature sensor is detachably fixed to the outer wall of the inner pot, and is arranged close to the other end of the first electric heating tube.

2. The instant electric water heater according to claim 1, characterized in that: The distance between the first temperature sensor and the other end of the first electric heating tube is 2 cm to 10 cm.

3. The instant electric water heater according to claim 1, characterized in that: The other end of the first electric heating tube is arranged close to the water outlet end of the water outlet pipe.

4. The instant electric water heater according to claim 3, characterized in that: It also includes a heat collecting cup with openings at both ends. The heat collecting cup is fixed to the other end of the first electric heating tube and is respectively sleeved on the other end of the first electric heating tube and the water outlet pipe.

5. The instant electric water heater according to claim 4, characterized in that: The temperature detection end of the first temperature sensor is closely attached to the outer wall of the inner container, and at least a part of the temperature detection end of the first temperature sensor is located within the projection range of the inner container at one end surface of the heat collecting cup.

6. The instant electric water heater according to claim 1, characterized in that: It also includes a first threaded connector and a second threaded connector; the first threaded connector is fixedly connected to the outer wall of the inner container, and the first threaded connector is threadedly connected to the second threaded connector so that the first temperature sensor can be detachably fixed to the outer wall of the inner container.

7. The instant electric water heater according to claim 6, characterized in that: The first threaded connection is a screw, which is fixed to the outer wall of the inner tank; the second threaded connection is a nut; the first temperature sensor is provided with a mounting end; the screw is threadedly connected to the nut so that the nut presses the mounting end against the outer wall of the inner tank; or, the first threaded connection is a nut, which is fixed to the outer wall of the inner tank; the second threaded connection is a screw; the first temperature sensor is provided with a mounting end; the screw is threadedly connected to the nut so that the screw presses the mounting end against the outer wall of the inner tank.

8. The instant electric water heater according to claim 7, characterized in that: The mounting end is provided with a mounting hole, and the screw rod is passed through the mounting hole and is threadedly connected with the nut.

9. The instant electric water heater according to claim 1, characterized in that: It also includes a heat-conducting sleeve, the outer side wall of which is tightly fixed to the outer wall of the inner pot; the first temperature sensor is inserted and fixed to the heat-conducting sleeve so that the first temperature sensor can be detachably fixed to the outer wall of the inner pot.

10. The instant electric water heater according to claim 1, characterized in that: It also includes a controller, a second electric heating tube, a second temperature sensor and a temperature detection blind tube; one end of the second electric heating tube is fixedly connected to the inner pot, and the other end extends along the bottom direction of the inner pot; the temperature detection blind tube is fixedly connected to the inner pot and extends along the bottom direction of the inner pot, and the second temperature sensor is inserted in the temperature detection blind tube; the controller is electrically connected to the first electric heating tube, the second electric heating tube, the first temperature sensor and the second temperature sensor respectively.

Images