Heat exchange type water heater with dry burning prevention and automatic water replenishing functions

Abstract

The invention relates to a heat exchange type water heater with dry burning prevention and automatic water replenishing functions, which comprises a water tank, a heat exchange assembly, a water replenishing device, a liquid level sensor and a main control system, and a first heater is arranged in the water tank; the heat exchange assembly comprises a heat exchanger which is arranged in the water tank; the water replenishing device is used for replenishing water into the water tank; the liquid level sensor is used for detecting the liquid level in the water tank; the first heater, the heat exchange assembly, the water supplementing device and the liquid level sensor are electrically connected with the main control system. The master control system is configured to control the first heater to be closed and control the water supplementing device to work when it is detected that the liquid level in the water tank is lower than a first position. When it is detected that the liquid level is located between the first position and the second position, the first heater and the water supplementing device are controlled to work; the second position is located above the first position; when the liquid level is detected to be higher than the second position, the water supplementing device is controlled to be closed. By means of the liquid level sensor and the main control system, the purposes of preventing dry burning and automatically supplementing water are achieved.

Description

Technical Field

[0001] The present application relates to the technical field of water heater equipment, and in particular to a heat exchange water heater with anti-dry-burning and automatic water replenishment functions. Background Art

[0002] An electric water heater is a water heater that uses electricity as energy for heating. It is one of the three major water heaters along with gas water heaters and solar water heaters. An electric water heater includes a water tank and a heating element. The heating element is located in the water tank to heat the water in the water tank. Since the heating element is an electric heating device, it will continue to heat after being powered on. If the water level in the water tank is low, dry burning is likely to occur. Summary of the invention

[0003] The present application provides a heat exchange water heater with dry-burn prevention and automatic water replenishment functions to achieve the purpose of dry-burn prevention and automatic water replenishment.

[0004] The present application provides a heat exchange water heater with anti-dry-burning and automatic water replenishment functions, comprising:

[0005] a water tank, wherein a first heater is provided in the water tank;

[0006] The heat exchange assembly comprises a heat exchanger, a water inlet pipeline and a water outlet pipeline, wherein the heat exchanger is arranged in the water tank; the water inlet pipeline and the water outlet pipeline are respectively connected to two ends of the heat exchanger and extend out of the water tank;

[0007] A water replenishing device, the water replenishing device is connected to the water tank and is used to replenish water into the water tank;

[0008] A liquid level sensor, used for detecting the liquid level in the water tank;

[0009] A main control system, wherein the first heater, the heat exchange assembly, the water replenishing device and the liquid level sensor are electrically connected to the main control system respectively; wherein the main control system is configured as follows:

[0010] When the liquid level sensor detects that the liquid level in the water tank is lower than a first position, the first heater is controlled to be turned off, and the water replenishing device is controlled to work; wherein the first position is higher than the upper side of the heat exchanger, or is flush with the upper side of the heat exchanger;

[0011] When the liquid level sensor detects that the liquid level in the water tank is between a first position and a second position, the first heater and the water replenishing device are controlled to operate; wherein the second position is above the first position;

[0012] When the liquid level sensor detects that the liquid level in the water tank is higher than the second position, the water replenishing device is controlled to be closed.

[0013] Furthermore, the liquid level sensor detects the liquid level in the water tank in real time, and sends the detected liquid level information to the main control system.

[0014] Furthermore, the second position is lower than an upper side wall of the inner cavity of the water tank.

[0015] Furthermore, it also includes an overflow device, which is installed in the water tank, and the upper overflow port of the overflow device is higher than the second position, or is flush with the second position.

[0016] Furthermore, the overflow device is provided with a check valve.

[0017] Furthermore, it also includes a thermostatic valve and a cold water branch, the thermostatic valve is electrically connected to the main control system; the cold water branch is connected to the water inlet pipeline, and the cold water branch and the water outlet pipeline are respectively connected to the thermostatic valve to mix the cold water in the cold water pipeline with the hot water in the water outlet pipeline to obtain mixed water.

[0018] Furthermore, it also includes a mixed water outlet pipe, which is connected to the thermostatic valve to output the mixed water;

[0019] It also includes a second heater, which is arranged on the mixed water outlet pipe and is used to heat the mixed water; the second heater is electrically connected to the main control system.

[0020] Furthermore, the water replenishing device includes a water replenishing pipe, which is passed through the water tank, one end of which is located inside the water tank, and the other end of which is located outside the water tank.

[0021] Furthermore, the water supply pipe is connected to the water inlet pipeline, and the water supply pipe is provided with a solenoid valve, and the solenoid valve is electrically connected to the main control system;

[0022] Or, the water supply pipe is connected to the thermostatic valve;

[0023] Alternatively, the water supply pipe is connected to an external water supply device, the water supply pipe is provided with a solenoid valve, and the solenoid valve is electrically connected to the main control system.

[0024] Furthermore, a heat-insulating layer is provided on the outer periphery of the water tank.

[0025] The above technical solution provided by this application has the following advantages compared with the prior art:

[0026] In the technical solution of the present application, when the first heater generates heat, the liquid in the water tank is heated, and water is supplied to the heat exchanger through the water inlet pipe. The water flow in the heat exchanger exchanges heat with the liquid in the water tank during the flow process, takes away the heat, and discharges the water after absorbing heat from the water outlet pipe for use. In this way, the water supply of the water heater is flowing living water, not stored water. At the same time, the liquid level in the water tank is detected by the liquid level sensor in the present application. When the liquid level drops to the first position, it indicates that water replenishment is needed at this time. To avoid dry burning, the first heater is turned off at this time, and the water replenishment device is controlled to work to replenish the water tank. When the liquid level is between the first position and the second position, there is no risk of dry burning at this time, the first heater can work normally, and the water replenishment device still replenishes the water tank until the liquid level in the water tank leads to the second position. At this time, the liquid in the water tank is sufficient, and the water replenishment device can be controlled to be closed and stop replenishing water. The present application achieves the purpose of preventing dry burning and automatic water replenishment through the liquid level sensor and the main control system. The first position is set to be higher than or flush with the upper side of the heat exchanger, so that the heat exchanger can be always immersed in the liquid in the water tank, thereby ensuring the heat exchange effect of the heat exchanger. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the invention and, together with the description, serve to explain the principles of the invention.

[0028] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, for ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative labor.

[0029] One or more embodiments are exemplarily described by pictures in the corresponding drawings, and these exemplified descriptions do not constitute limitations on the embodiments. Elements with the same reference numerals in the drawings represent similar elements, and unless otherwise stated, the figures in the drawings do not constitute proportional limitations.

[0030] Figure 1 A schematic structural diagram of a heat exchange water heater with anti-dry-burning and automatic water replenishment functions provided in the first embodiment of the present application;

[0031] Figure 2 for Figure 1 An enlarged schematic diagram of the coordination between the liquid level sensor and the water tank;

[0032] Figure 3 Shows Figure 1 waterways in;

[0033] Figure 4This is a schematic diagram of the control flow of the main control system in the embodiment of the present application;

[0034] Figure 5 A schematic structural diagram of a heat exchange water heater with anti-dry-burning and automatic water replenishment functions provided in the second embodiment of the present application;

[0035] Figure 6 A schematic structural diagram of a heat exchange water heater with anti-dry-burning and automatic water replenishment functions provided in the third embodiment of the present application.

[0036] Description of reference numerals:

[0037] Water tank 1, insulation layer 11, first position 1a, second position 1b, first heater 2, heat exchanger 31, water inlet pipeline 32, water outlet pipeline 33, cold water branch 34, mixed water outlet pipe 35, second heater 36, water replenishment device 4, water replenishment pipe 41, solenoid valve 42, liquid level sensor 5, high-level signal collection point 51, low-level signal collection point 52, main control system 6, overflow device 7, check valve 71, thermostatic valve 8, shell 9. DETAILED DESCRIPTION

[0038] In order to make the purpose, technical solution and advantages of the embodiments of the present application clearer, 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 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 making creative work are within the scope of protection of this application.

[0039] The disclosure below provides many different embodiments or examples to implement different structures of the present invention. In order to simplify the disclosure of the present invention, the parts and settings of specific examples are described below. Of course, they are only examples, and the purpose is not to limit the present invention. In addition, the present invention can repeat reference numbers and / or letters in different examples. This repetition is for the purpose of simplification and clarity, and does not itself indicate the relationship between the various embodiments and / or settings discussed.

[0040] For ease of description, spatial relative terms may be used herein to describe the relative positional relationship or movement of one element or feature relative to another element or feature as shown in the figure, such as "inside", "outside", "inner side", "outer side", "below", "below", "above", "above", "front", "back", etc. Such spatial relative terms are intended to include different orientations of the device in use or operation in addition to the orientation depicted in the figure. For example, if the device in the figure undergoes a position flip or a posture change or a motion state change, then these directional indications also change accordingly, for example: an element described as "below other elements or features" or "below other elements or features" will subsequently be oriented as "above other elements or features" or "above other elements or features". Therefore, the example term "below..." may include both upper and lower orientations. The device may be otherwise oriented (rotated 90 degrees or in other directions) and the spatial relative descriptors used herein are interpreted accordingly.

[0041] The present application provides a heat exchange water heater with anti-dry-burning and automatic water replenishment functions, in particular, an electric water heater.

[0042] Figures 1 to 3 A heat exchange water heater with anti-dry-burning and automatic water replenishment functions provided in the first embodiment of the present application includes a water tank 1, a heat exchange component, a water replenishment device 4, a liquid level sensor 5 and a main control system 6. A first heater is provided in the water tank 1; the heat exchange component includes a heat exchanger 31, a water inlet pipeline 32 and a water outlet pipeline 33, and the heat exchanger 31 is provided in the water tank 1; the water inlet pipeline 32 and the water outlet pipeline 33 are respectively connected to the two ends of the heat exchanger 31 and extend out of the water tank 1; the water replenishment device 4 is connected to the water tank 1 and is used to replenish water into the water tank 1; the liquid level sensor 5 is used to detect the liquid level in the water tank 1; the first heater, the heat exchange component, the water replenishment device 4 and the liquid level sensor 5 are respectively electrically connected to the main control system 6;

[0043] The main control system 6 is configured as follows:

[0044] When the liquid level sensor 5 detects that the liquid level in the water tank 1 is lower than the first position, the first heater is controlled to be turned off, and the water replenishing device 4 is controlled to work; wherein the first position is higher than the upper side of the heat exchanger 31, or is flush with the upper side of the heat exchanger 31;

[0045] When the liquid level sensor 5 detects that the liquid level in the water tank 1 is between the first position and the second position, the first heater and the water replenishing device 4 are controlled to work; wherein the second position is above the first position;

[0046] When the liquid level sensor 5 detects that the liquid level in the water tank 1 is higher than the second position, the water replenishing device 4 is controlled to be closed.

[0047] It can be understood that when the first heater generates heat, the liquid in the water tank 1 is heated, and water is provided to the heat exchanger 31 through the water inlet pipe 32. The water flow in the heat exchanger 31 exchanges heat with the liquid in the water tank 1 during the flow process, takes away the heat, and discharges the water after absorbing the heat from the water outlet pipe 33 for use. In this way, the water supply of the water heater is flowing living water, not stored water. At the same time, in this application, the liquid level in the water tank 1 is detected by the liquid level sensor 5. When the liquid level drops to the first position, it indicates that water replenishment is needed at this time. In order to avoid dry burning, the first heater is turned off at this time, and the water replenishment device 4 is controlled to work to replenish water to the water tank 1. When the liquid level is between the first position and the second position, there is no risk of dry burning at this time, the first heater can work normally, and the water replenishment device 4 still replenishes water to the water tank 1 until the liquid level in the water tank 1 leads to the second position. At this time, the liquid in the water tank 1 is sufficient, and the water replenishment device 4 can be controlled to be closed to stop replenishing water. This application achieves the purpose of preventing dry burning and automatic water replenishment through the liquid level sensor 5 and the main control system 6. The first position is set to be higher than or flush with the upper side of the heat exchanger 31 , so that the heat exchanger 31 is always immersed in the liquid in the water tank 1 , thereby ensuring the heat exchange effect of the heat exchanger 31 .

[0048] like Figure 1 and Figure 2 As shown, in this embodiment, the liquid level sensor 5 includes a high-level signal collection point 51 and a low-level signal collection point 52. The high-level signal collection point corresponds to the second position, and the low-level signal collection point 52 corresponds to the first position. The distance between the high-level signal collection point 51 and the low-level signal collection point 52 is L, that is, the distance between the first position and the second position is L. In one embodiment, L≥8mm.

[0049] As shown in Table 1 below, there are three states after the liquid level sensor 5 starts working: State 1 represents water shortage and the first heater is prohibited from running, at this time the water replenishment device 4 is in the water replenishment state; State 2 is that the high-level signal collection point 51 is short of water, the first heater is started, and the water replenishment device 4 is in the water replenishment state; State 3 is a full water signal, and the water replenishment device 4 stops adding water.

[0050] Table 1

[0051]

[0052] refer to Figure 4 Specifically, the logical flow of the control system of the heat exchange water heater provided in the present application is shown. Specifically, when the heat exchange water heater is powered on, the liquid level sensor 5 starts working immediately to detect the liquid level in the water tank 1.

[0053] When the liquid level is detected to be in state 1, the first heater is prohibited from running, and the water replenishment device 4 starts to replenish water. Figure 4The valve core action corresponds to Figure 1 The thermostatic valve 8 in the first embodiment, or Figure 5 The solenoid valve 42 in the second embodiment, or Figure 6 The electromagnetic valve 42 in the third embodiment. That is, the operation or closing of the water replenishing device 4 can be controlled by the action of the valve core corresponding to the thermostatic valve 8 or the electromagnetic valve 42.

[0054] When the liquid level is detected to be in state 2, the heat exchanger 31 is completely immersed in the liquid in the water tank 1, and the first heater can start to work normally to heat the liquid in the water tank 1. At this time, the water replenishing device 4 still works to replenish water.

[0055] When the liquid level is detected to be in state three, the liquid level in the water tank 1 of the heat exchanger 31 has reached the preset maximum position, and the water replenishing device 4 stops working.

[0056] In this embodiment, different from the traditional water storage type electric water heater, the water tank 1 described in the present application is an open water tank 1.

[0057] In this embodiment, the first heater is disposed at the lower position of the water tank 1 .

[0058] In the technical solution of this embodiment, the liquid level sensor 5 detects the liquid level in the water tank 1 in real time, and sends the detected liquid level information to the main control system 6. In this way, the main control system 6 can obtain real-time information on the liquid level in the water tank 1, can perform accurate control, improve control accuracy, and further reduce dry burning and overflow.

[0059] like Figure 1 As shown, in the technical solution of the first embodiment, the second position is lower than the upper side wall of the inner cavity of the water tank 1. When the liquid level in the water tank 1 reaches the maximum position, the liquid in the water tank 1 will not fill the entire water tank 1, and a part of the space will be left at the top of the water tank 1 for the volume expansion space when the liquid is heated.

[0060] To ensure that the liquid level in the water tank 1 is always at a distance from the upper side wall of the water tank 1, Figure 1 and Figure 3 As shown, in the technical solution of this embodiment, an overflow device 7 is also included. The overflow device 7 is installed in the water tank 1, and the upper overflow port of the overflow device 7 is higher than the second position, or flush with the second position. When the liquid level in the water tank 1 is replenished to the second position by the water replenishing device 4, the preset full water position has been reached. When the water replenishing device 4 stops replenishing water, the water replenishing is delayed, etc., and the water tank 1 is still replenished, the excess liquid will automatically flow out of the water tank 1 through the overflow device 7. In this way, the heat exchange water heater does not bear the water inlet pressure and the expansion pressure of the heated liquid, which can effectively improve the service life.

[0061] In this embodiment, the overflow is an overflow pipe.

[0062] like Figure 1 and Figure 3 As shown, in the technical solution of the first embodiment, the overflow device 7 is provided with a check valve 71. It can be understood that the flow direction of the liquid in the overflow pipe can be controlled by providing the check valve 71.

[0063] like Figure 1 and Figure 3 As shown, in the technical solution of the first embodiment, it also includes a thermostatic valve 8 and a cold water manifold 34, the thermostatic valve 8 is electrically connected to the main control system 6; the cold water manifold 34 is connected to the water inlet pipeline 32, and the cold water manifold 34 and the water outlet pipeline 33 are respectively connected to the thermostatic valve 8 to mix the cold water in the cold water pipeline with the hot water in the water outlet pipeline 33 to obtain mixed water.

[0064] It is understandable that the heat exchanger 31 is immersed in the water in the water tank 1, and the inside is a pipeline for flowing through the cold water provided from the water inlet pipeline 32. When the cold water flows through the heat exchanger 31, the heat of the water in the water tank 1 is transferred out, thereby turning the cold water into hot water. In order to ensure sufficient hot water, a thermostatic valve 8 is set to mix cold water and hot water, and then output the mixed water to avoid directly outputting hot water that is overheated and causes burns. The cold water mixed by the user is obtained from the water inlet pipeline 32 through the cold water branch 34, which can ensure that the mixed water is flowing water, not stored water.

[0065] like Figure 1 and Figure 3 As shown, in the technical solution of the first embodiment, a mixed water outlet pipe 35 is also included, and the mixed water outlet pipe 35 is connected to the thermostatic valve 8 to output mixed water;

[0066] It also includes a second heater 36 , which is disposed on the mixed water outlet pipe 35 for heating the mixed water; the second heater 36 is electrically connected to the main control system 6 .

[0067] It can be understood that, by providing a mixed water outlet pipe 35 for drawing out mixed water, the mixed water is then heated by the second heater 36 to reach the water temperature required by the user.

[0068] like Figure 1 and Figure 3 As shown, in the technical solution of the first embodiment, the water replenishment device 4 includes a water replenishment pipe 41, which is arranged in the water tank 1, one end of which is located in the water tank 1, and the other end of which is located outside the water tank 1. An overflow port is arranged at the upper end of the water replenishment pipe 41.

[0069] like Figure 1 and Figure 3As shown, in the technical solution of the first embodiment, the water supply pipe 41 is connected to the thermostatic valve 8; the main control system 6 controls the operation and closing of the water supply pipe 41 by controlling the thermostatic valve 8. When the water supply pipe 41 is working, the cold water provided by the cold water branch pipe is divided into two paths by the thermostatic valve 8, one path enters the water supply pipe 41, and the other path is mixed with the hot water in the water outlet pipe 33.

[0070] like Figure 5 As shown, in the technical solution of the second embodiment of the present application, the water supply pipe 41 is connected to the water inlet pipeline 32, and the water supply pipe 41 is provided with a solenoid valve 42, and the solenoid valve 42 is electrically connected to the main control system 6; the main control system 6 controls the operation and closing of the water supply pipe 41 by controlling the solenoid valve 42. In the second embodiment, except that the setting of the water supply device 4 is different from that of the first embodiment, other contents are the same as those of the first embodiment.

[0071] like Figure 6 As shown, in the technical solution of the third embodiment of the present application, the water supply pipe 41 is connected to the external water supply device, and the water supply pipe 41 is provided with a solenoid valve 42, and the solenoid valve 42 is electrically connected to the main control system 6. The main control system 6 controls the operation and closing of the water supply pipe 41 by controlling the solenoid valve 42. In the third embodiment, except that the setting of the water supply device 4 is different from that of the first embodiment, other contents are the same as those of the first embodiment.

[0072] like Figure 1 , Figure 5 and Figure 6 As shown, in the technical solution of this embodiment, a heat-insulating layer 11 is provided on the periphery of the water tank 1. The heat-exchange water heater further comprises a housing 9, the water tank 1 is arranged in the housing 9, and the main control system 6 and the like are arranged in the housing 9. The heat-insulating layer 11 is arranged on the periphery of the water tank 1 and is located between the housing 9 and the water tank 1. The heat-insulating layer 11 can play a heat-insulating role, prevent the heat loss of the liquid in the water tank 1, and improve the heat exchange effect.

[0073] The thermal insulation layer 11 can be made of foam material, EPS, rubber and plastic wool, vacuum insulation board, glass fiber wool, etc.

[0074] It should be understood that the terms used herein are only for the purpose of describing specific example embodiments and are not intended to be limiting. Unless the context clearly indicates otherwise, the singular forms "one", "an" and "said" as used herein may also be meant to include plural forms. The terms "include", "comprise", "contain", and "have" are inclusive, and therefore specify the existence of stated features, steps, operations, elements and / or parts, but do not exclude the existence or addition of one or more other features, steps, operations, elements, parts, and / or combinations thereof. The method steps, processes, and operations described herein are not interpreted as necessarily requiring them to be performed in the specific order described or illustrated, unless the execution order is clearly indicated. It should also be understood that additional or alternative steps may be used.

[0075] Although the terms first, second, third, etc. can be used in the text to describe multiple elements, components, regions, layers and / or sections, these elements, components, regions, layers and / or sections should not be limited by these terms. These terms can only be used to distinguish an element, component, region, layer or section from another region, layer or section. Unless the context clearly indicates, terms such as "first", "second" and other numerical terms do not imply order or sequence when used in the text. Therefore, the first element, component, region, layer or section discussed below can be referred to as the second element, component, region, layer or section without departing from the teaching of the example embodiments.

[0076] The foregoing is merely a specific embodiment of the present invention, which enables those skilled in the art to understand or implement the present invention. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but rather to the widest scope consistent with the principles and novel features claimed herein.

Claims

1. A heat exchange water heater with anti-dry burning and automatic water replenishment functions, characterized in that: include: A water tank (1), wherein a first heater is provided in the water tank (1); A heat exchange assembly, comprising a heat exchanger (31), a water inlet pipeline (32) and a water outlet pipeline (33), wherein the heat exchanger (31) is arranged in the water tank (1); the water inlet pipeline (32) and the water outlet pipeline (33) are respectively connected to two ends of the heat exchanger (31) and extend out of the water tank (1); a water replenishing device (4), the water replenishing device (4) being connected to the water tank (1) and being used to replenish water into the water tank (1); A liquid level sensor (5) for detecting the liquid level in the water tank (1); A main control system (6), wherein the first heater, the heat exchange component, the water replenishment device (4) and the liquid level sensor (5) are electrically connected to the main control system (6) respectively; wherein the main control system (6) is configured as follows: When the liquid level sensor (5) detects that the liquid level in the water tank (1) is lower than a first position, the first heater is controlled to be turned off, and the water replenishment device (4) is controlled to operate; wherein the first position is higher than the upper side of the heat exchanger (31), or is flush with the upper side of the heat exchanger (31); When the liquid level sensor (5) detects that the liquid level in the water tank (1) is between a first position and a second position, the first heater and the water replenishing device (4) are controlled to operate; wherein the second position is above the first position; When the liquid level sensor (5) detects that the liquid level in the water tank (1) is higher than the second position, the water replenishing device (4) is controlled to be closed.

2. The heat exchange water heater according to claim 1, characterized in that: The liquid level sensor (5) detects the liquid level in the water tank (1) in real time, and sends the detected liquid level information to the main control system (6).

3. The heat exchange water heater according to claim 1, characterized in that: The second position is lower than the upper side wall of the inner cavity of the water tank (1).

4. The heat exchange water heater according to claim 1, characterized in that: It also comprises an overflow device (7), wherein the overflow device (7) is disposed through the water tank (1), and an upper overflow port of the overflow device (7) is higher than the second position, or is flush with the second position.

5. The heat exchange water heater according to claim 4, characterized in that: The overflow device (7) is provided with a check valve (71).

6. The heat exchange water heater according to claim 1, characterized in that: It also comprises a thermostatic valve (8) and a cold water branch (34), wherein the thermostatic valve (8) is electrically connected to the main control system (6); the cold water branch (34) is connected to the water inlet pipeline (32), and the cold water branch (34) and the water outlet pipeline (33) are respectively connected to the thermostatic valve (8) so as to mix the cold water in the cold water pipeline with the hot water in the water outlet pipeline (33) to obtain mixed water.

7. The heat exchange water heater according to claim 6, characterized in that: It also includes a mixed water outlet pipe (35), which is connected to the thermostatic valve (8) to output the mixed water; It also includes a second heater (36) which is arranged on the mixed water outlet pipe (35) and is used to heat the mixed water; the second heater (36) is electrically connected to the main control system (6).

8. The heat exchange water heater according to claim 6, characterized in that: The water replenishment device (4) comprises a water replenishment pipe (41), wherein the water replenishment pipe (41) is passed through the water tank (1), one end of the water replenishment pipe (41) is located inside the water tank (1), and the other end is located outside the water tank (1).

9. The heat exchange water heater according to claim 8, characterized in that: The water supply pipe (41) is connected to the water inlet pipeline (32), and the water supply pipe (41) is provided with a solenoid valve (42), and the solenoid valve (42) is electrically connected to the main control system (6); Or, the water supply pipe (41) is connected to the thermostatic valve (8); Alternatively, the water supply pipe (41) is connected to an external water supply device, the water supply pipe (41) is provided with a solenoid valve (42), and the solenoid valve (42) is electrically connected to the main control system (6).

10. The heat exchange water heater according to any one of claims 1 to 9, characterized in that: The outer periphery of the water tank (1) is provided with a heat-insulating layer (11).

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