An electric water heater detection method, a detection circuit and an electric water heater

Abstract

The application discloses a kind of electric water heater detection method, detection circuit and electric water heater, the detection method includes, the resistance between the inner container of electric water heater and heating pipe is detected, according to the resistance value of detection judges whether the water level in inner container is higher than safe water level.The application judges whether the water level in electric inner container is higher than safe water level according to the resistance between the inner container of electric water heater and heating pipe, the resistance between inner container and heating pipe is larger when the water level in inner container is lower than safe water level, the resistance between inner container and heating pipe is smaller when water level is higher than safe water level, detection method is simple, easy to realize, and detection accuracy is high.Meanwhile the application can be detected when heating pipe stops heating, avoids heating pipe dry burning in detection process, improves the service life of heating pipe, reduces security risk.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of water heaters, in particular, relates to a detection method and detection circuit for an electric water heater and a water heater. BACKGROUND

[0002] With the improvement of people's living standards, the demand for hot water is also increasing, and the water heater as a household appliance that can store hot water has been widely used in people's daily life. According to the heating method of the water heater, the water heater can be divided into electric water heater, solar water heater, gas water heater, magnetic energy water heater, etc. Among them, the electric water heater has become the first choice of more and more users due to its simple installation and convenient use.

[0003] The electric water heater includes an inner container for storing water, and a heating pipe is arranged in the inner container to heat the water in the inner container. A temperature sensor is also arranged in the inner container, and the heating pipe stops working when the water is heated to the temperature set by the user. Due to the heat preservation function of the inner container, the water in the inner container can be prevented from cooling down quickly after the heating pipe stops working, so that the user can use hot water at any time. During the heating process of the heating pipe, if the water level in the inner container is low, dry burning will occur, which will affect the service life of the heating pipe.

[0004] One existing Chinese patent discloses an electric water heater dry burning prevention control method, which includes the following steps: obtaining a temperature rise rate threshold value; detecting the temperature of the inner container of the electric water heater and calculating the temperature rise rate according to the temperature of the inner container; determining whether the electric water heater is dry burning according to the temperature rise rate and the temperature rise rate threshold value; if the electric water heater is dry burning, controlling the electric water heater to stop heating; if the electric water heater is not dry burning, updating the temperature rise rate threshold value according to the temperature rise rate. In the prior art, the temperature rise rate of the inner container is detected during the heating process to determine whether dry burning occurs. If the temperature rise rate exceeds the preset value, it is determined that dry burning occurs and the heating is stopped.

[0005] In the prior art, the electric water heater needs to be heated for a period of time to determine whether the water heater is dry burning, and the temperature rise rate of the inner container is used to determine whether dry burning occurs. If dry burning occurs, the heating pipe has been dry burning for a certain period of time, which is not timely and affects the service life of the water heater.

[0006] Therefore, the present application is proposed. SUMMARY

[0007] The technical problem to be solved by the present application is to overcome the shortcomings of the prior art and provide an electric water heater detection method, detection circuit and electric water heater, which can determine whether the water heater is dry burning in time and improve the service life of the water heater.

[0008] To solve the above technical problems, the basic idea of the technical solution of the present application is:

[0009] The application discloses an electric water heater detection method, which detects the resistance value between an inner container and a heating pipe of the electric water heater, and judges whether the water level in the inner container is higher than a safety water level according to the detected resistance value.

[0010] Preferably, the resistance value between the inner container and the heating pipe is detected for multiple times continuously, and if the detected resistance value is within a preset range, it is judged that the water level in the inner container is higher than the safety water level.

[0011] Preferably, if the detected resistance value between the inner container and the heating pipe is out of the preset range, it is judged that the water level in the inner container is lower than the safety water level, and the detection of the resistance value between the inner container and the heating pipe is stopped.

[0012] Preferably, after the resistance value between the inner container and the heating pipe is detected, the detected resistance value is converted into an AD value, and if the AD value is less than a preset value, it is judged that the water level in the inner container is higher than the safety water level.

[0013] Preferably, before the heating pipe starts to heat, the resistance value between the inner container and the heating pipe is detected, and if it is judged that the water level in the inner container is higher than the safety water level, the heating pipe is controlled to start to heat the water in the inner container.

[0014] Another object of the application is to provide a detection circuit of an electric water heater adopting the detection method.

[0015] A resistance-capacitance circuit connected with a power supply;

[0016] A voltage stabilizing circuit connected with the resistance-capacitance circuit, and connected with an analog-digital converter;

[0017] A protection circuit connected with the resistance-capacitance circuit.

[0018] Preferably, the resistance-capacitance circuit comprises an electric connector J1, a pin 1 of the electric connector J1 is grounded, a pin 2 of the electric connector J1 is connected to a first end of a resistor R11 through resistors R14, R13, R12 and a capacitor C11 connected in series, and a second end of the resistor R11 is connected with the power supply.

[0019] Preferably, the protection circuit comprises a triode N1, a collector of the triode N1 is connected with the first end of the resistor R11, a base of the triode N1 is connected to a pulse input signal PWM, and an emitter of the triode N1 is grounded.

[0020] Preferably, the voltage stabilizing circuit comprises a diode D1, a positive electrode of the diode D1 is connected with a first end of a resistor R11, a negative electrode of the diode D1 is connected with a first end of a resistor R15, a second end of the resistor R15 is connected with a first end of a resistor R16, a first end of a capacitor C12 and a first end of a resistor R17, a second end of the resistor R17 is connected with a negative electrode of a voltage stabilizing tube ZD1, a first end of a capacitor C13 and an analog-digital converter, a second end of the resistor R16, a second end of the capacitor C12, a positive electrode of the voltage stabilizing tube ZD1 and a second end of the capacitor C13 are grounded.

[0021] Another object of the present application is to provide an electric water heater comprising:

[0022] The inner container is internally provided with a heating pipe, and the inner container and the heating pipe are insulated;

[0023] The detection circuit board is provided with the detection circuit as described above, a pin 1 of an electric connector J1 is connected with the inner container, and a pin 2 of the electric connector J1 is connected with the heating pipe.

[0024] Compared with the prior art, the present application has the following beneficial effects:

[0025] 1. The present application judges whether the water level in the inner container is higher than the safe water level according to the resistance value between the inner container and the heating pipe of the electric water heater, the resistance value between the inner container and the heating pipe is larger when the water level in the inner container is lower than the safe water level, and the resistance value between the inner container and the heating pipe is smaller when the water level is higher than the safe water level, so that the detection method is simple, easy to implement and has high detection accuracy.

[0026] 2. The present application improves the accuracy of the judgment result by continuously detecting the resistance value between the inner container and the heating pipe multiple times, thereby avoiding detection errors caused by accidental factors.

[0027] 3. The present application detects when the heating pipe stops heating, thereby avoiding dry burning of the heating pipe during the detection process, improving the service life of the heating pipe and reducing safety hazards.

[0028] The specific embodiments of the present application will be described in further detail below with reference to the accompanying drawings. BRIEF DESCRIPTION OF DRAWINGS

[0029] The accompanying drawings are part of the present application and serve to provide a further understanding of the present application, the illustrative embodiments of the present application and their descriptions serve to explain the present application but do not constitute an improper limitation of the present application. Obviously, the accompanying drawings described below are only some embodiments, and other drawings can be obtained from these drawings without creative labor for those skilled in the art. In the drawings:

[0030] Figure 1 is a flow diagram of an electric water heater detection method of the present application.

[0031] Figure 2 This is a schematic diagram of the detection circuit for an electric water heater according to the present invention.

[0032] It should be noted that these accompanying drawings and textual descriptions are not intended to limit the scope of the invention in any way, but rather to illustrate the concept of the invention to those skilled in the art by referring to specific embodiments. Detailed Implementation

[0033] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments will be clearly and completely described below with reference to the accompanying drawings. The following embodiments are used to illustrate the present invention, but are not intended to limit the scope of the present invention.

[0034] In the description of this invention, it should be noted that the terms "upper", "lower", "front", "rear", "left", "right", "vertical", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limiting this invention.

[0035] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0036] like Figure 1 As shown in the figure, this embodiment of the invention introduces a method for testing an electric water heater, which detects the resistance value between the inner tank and the heating element of the electric water heater, and determines whether the water level in the inner tank is higher than the safe water level based on the detected resistance value.

[0037] Electric water heaters typically contain a certain amount of water in the inner tank, which is equipped with a heating element to heat the water. The inner tank also has an insulation function to reduce the cooling effect of the water, allowing users to access the stored hot water at any time. To extend the lifespan of the heating element and avoid safety hazards, dry burning must be prevented. Dry burning occurs when the heating element is not submerged in water, the water level in the inner tank is lower than the heating element, and the element is directly exposed to air, leading to premature aging and a shortened lifespan. When the heating element is in operation, the water level in the inner tank must be maintained above a safe level, which means the water level in the inner tank is higher than the heating element.

[0038] When the water level in the inner container is lower than the safe water level, that is, the water level in the inner container is lower than the heating tube, the inner container and the heating tube are in an insulating state, and the resistance value between the inner container and the heating tube is high. When the water level in the inner container is higher than the safe water level, that is, the water level in the inner container is higher than the heating tube, the inner container and the heating tube are connected through water, and since water has conductivity, the inner container and the heating tube are in conduction, and the resistance value between the inner container and the heating tube is low.

[0039] The application detects the resistance value between the inner container and the heating tube of the electric water heater, judges whether the water level in the inner container is higher than the safe water level according to the detected resistance value, and has a simple detection method, is easy to implement, and has high detection accuracy.

[0040] In the embodiment of the application, the resistance value between the inner container and the heating tube is detected continuously for multiple times, and if the resistance value detected each time is within a preset range, it is judged that the water level in the inner container is higher than the safe water level.

[0041] If the resistance value between the inner container and the heating tube is detected to be out of the preset range, it is judged that the water level in the inner container is lower than the safe water level, and the detection of the resistance value between the inner container and the heating tube is stopped.

[0042] The application continuously detects the resistance value between the inner container and the heating tube for multiple times, improves the accuracy of the judgment result, and avoids detection errors caused by accidental factors. When the resistance value detected once is out of the preset range, it is considered that the water level in the inner container is lower than the safe water level, and the detection is stopped.

[0043] In the embodiment of the application, after the resistance value between the inner container and the heating tube is detected, the detected resistance value is converted into an AD value, and if the AD value is less than a preset value, it is judged that the water level in the inner container is higher than the safe water level. The preset value is preferably 1.5V.

[0044] The application converts the detected resistance value into an AD value, improves the stability of the detection result, and further improves the accuracy of the result of judging whether the water level in the inner container is higher than the safe water level.

[0045] In the embodiment of the application, before the heating tube starts heating, the resistance value between the inner container and the heating tube is detected, and if it is judged that the water level in the inner container is higher than the safe water level, the heating tube is controlled to start heating the water in the inner container.

[0046] If the water level in the inner container is lower than the safe water level during the detection when the heating tube is heating, the heating tube is still in a dry heating state during the detection, which affects the service life of the heating tube.

[0047] The application detects before the heating tube starts heating, if the water level in the inner container is higher than the safe water level, the heating tube starts heating the water in the inner container, if the water level in the inner container is lower than the safe water level, the heating tube is closed to avoid dry burning of the heating tube.

[0048] As shown in Figure 2 The application embodiment introduces a detection circuit of an electric water heater, which comprises: a resistance-capacitance circuit connected with a power supply; a voltage stabilizing circuit connected with the resistance-capacitance circuit and connected with an analog-digital converter; and a protection circuit connected with the resistance-capacitance circuit.

[0049] The resistance-capacitance circuit comprises an electric connector J1, a pin 1 of the electric connector J1 is grounded, a pin 2 of the electric connector J1 is connected to a first end of a resistor R11 through resistors R14, R13, R12 and a capacitor C11 in series connection, and a second end of the resistor R11 is connected with the power supply.

[0050] The protection circuit comprises a triode N1, a collector of the triode N1 is connected with the first end of the resistor R11, a base of the triode N1 is connected to a pulse input signal PWM, and an emitter of the triode N1 is grounded.

[0051] The voltage stabilizing circuit comprises a diode D1, a positive pole of the diode D1 is connected with the first end of the resistor R11, a negative pole of the diode D1 is connected with a first end of a resistor R15, a second end of the resistor R15 is connected with a first end of a resistor R16, a first end of a capacitor C12 and a first end of a resistor R17, a second end of the resistor R17 is connected with a negative pole of a voltage stabilizing tube ZD1, a first end of a capacitor C13 and the analog-digital converter, a second end of the resistor R16, a second end of the capacitor C12, a positive pole of the voltage stabilizing tube ZD1 and a second end of the capacitor C13 are all grounded.

[0052] When the water level in the inner container is lower than the safe water level, the inner container and the heating tube are insulated, and the resistance between the inner container and the heating tube is large, when the water level in the inner container is higher than the safe water level, the inner container and the heating tube are conductive through water, and the resistance between the inner container and the heating tube is small. The application can determine whether the water level in the inner container is higher than the safe water level at any time by connecting the detection circuit with the inner container and the heating tube and detecting the resistance value between the inner container and the heating tube. Meanwhile, the protection circuit in the detection circuit can avoid the elements in the circuit being broken down. The voltage stabilizing circuit is also provided to improve the stability of the detection result and make the determination result of the water level in the inner container more accurate.

[0053] The application embodiment introduces an electric water heater, which comprises: an inner container, a heating tube is arranged in the inner container, and the inner container and the heating tube are insulated; and a detection circuit board, the detection circuit board is provided with the detection circuit as described in the above embodiment, a pin 1 of an electric connector J1 is connected with the inner container, and a pin 2 of the electric connector J1 is connected with the heating tube.

[0054] Generally, a certain amount of water is stored in the inner container of the electric water heater, and a heating tube is arranged in the inner container to heat the water in the inner container. At the same time, the inner container has a heat preservation function, which can reduce the cooling effect of the water in the inner container, so that the user can use the hot water stored in the inner container at any time. In order to improve the service life of the heating tube and avoid safety hazards, it is necessary to avoid dry burning phenomenon, which refers to that the heating tube is not soaked in water during heating, and the heating tube is directly in contact with air, which causes the heating tube to easily age. When the heating tube is heating, it is necessary to ensure that the water level in the inner container is higher than the safe water level, which refers to that the water level in the inner container is higher than the heating tube.

[0055] When the water level in the inner container is lower than the safe water level, that is, the water level in the inner container is lower than the heating tube, the inner container and the heating tube are in an insulating state, and the resistance value between the inner container and the heating tube is high. When the water level in the inner container is higher than the safe water level, that is, the water level in the inner container is higher than the heating tube, the inner container and the heating tube are connected by water, and since water has conductivity, the inner container and the heating tube are in conduction, and the resistance value between the inner container and the heating tube is low.

[0056] The application detects the resistance value between the inner container and the heating tube through the detection circuit, and judges whether the water level in the inner container is higher than the safe water level according to the detection result of the resistance value. The detection method is simple, easy to implement, and has high detection accuracy.

[0057] In the embodiment of the application, the inner container is provided with a mounting hole, the heating tube penetrates through the mounting hole and extends into the inner container, and the heating tube is connected with a flange plate fixed outside the inner container. The inner container is provided with a bolt protruding towards the outside of the inner container, the flange plate is provided with a threaded hole, the bolt penetrates through the threaded hole, and the flange plate is fixed outside the inner container by screwing a nut on the bolt.

[0058] A first insulation part is arranged between the inner container and the flange plate, and a second insulation part is arranged on the bolt, the second insulation part being sleeved outside the bolt and arranged between the flange plate and the bolt. The second insulation part is provided with an annular flange near the side of the nut, and the annular flange is clamped between the nut and the flange plate.

[0059] A first electrode is arranged between the flange plate and the annular flange, and the first electrode is connected to the pin 2 of the electric connector J1 through a wire. A second electrode is arranged between the annular flange and the nut, and the second electrode is connected to the pin 1 of the electric connector J1 through a wire. The first electrode is connected to the heating tube through the flange plate, and the second electrode is connected to the inner container through the bolt.

[0060] When the water level in the inner container is lower than the safe water level, the water level in the inner container is lower than the heating tube, and since the first insulation part is arranged between the flange and the inner container, the flange and the inner container are insulated, which indicates that the first electrode and the second electrode are insulated. When the water level in the inner container is higher than the safe water level, the water level in the inner container is higher than the heating tube, and the heating tube and the inner container are conductive through water, and the first electrode and the second electrode are conductive.

[0061] The application detects the resistance value between the inner container and the heating tube through the detection circuit, and judges whether the water level in the inner container is higher than the safe water level according to the detection result of the resistance value, so that the detection method is simple, easy to implement, and has high detection accuracy.

[0062] In the description provided herein, a large number of specific details are described. However, it can be understood that the embodiments of the application can be practiced without these specific details. In some instances, well-known methods, structures and techniques have not been described in detail in order not to obscure the understanding of this description.

[0063] All features disclosed in this specification, including the claims, abstract, and drawings, can be combined in any combination, except such features and / or processes excluded in that the combination is mutually exclusive. Each feature disclosed in this specification (including the claims, abstract, and drawings) can also be replaced by alternative features providing the same, equivalent, or similar functionality unless expressly stated otherwise.

[0064] In addition, those skilled in the art can understand that although some embodiments described herein include certain features included in other embodiments but not others, the combination of features of different embodiments means within the scope of the application and forms different embodiments.

[0065] The above is only the preferred embodiment of the application, not any form of limitation on the application, although the application has been disclosed as above with the preferred embodiment, however, not to limit the application, any skilled person in the art can make some changes or modifications as equivalent embodiments with the above prompted technical content without departing from the scope of the technical solution of the application, the implementation of the above embodiments can be further combined or replaced, as long as it does not deviate from the content of the technical solution of the application, any simple modification, equivalent change and modification made on the above embodiments according to the technical essence of the application, still belongs to the scope of the application.

Claims

1. An electric water heater detection method, characterized in that, Detecting the resistance value between the inner container and the heating tube of the electric water heater, and judging whether the water level in the inner container is higher than the safe water level according to the detected resistance value; The inner container is provided with a bolt protruding outward, the bolt passes through the flange plate, and the flange plate is fixed to the outer side of the inner container through the nut and the bolt; One end of the heating tube extends into the inner container, and the other end is connected with the flange plate; A first insulation part is arranged between the inner container and the flange plate, and a second insulation part is arranged on the bolt between the flange plate and the bolt, the second insulation part is provided with an annular flange close to the nut side, and the annular flange is clamped between the nut and the flange plate; A first electrode is arranged between the flange plate and the annular flange, and a second electrode is arranged between the annular flange and the nut, the first electrode is connected to the heating tube through the flange plate, and the second electrode is connected to the inner container through the bolt; the resistance value between the first electrode and the second electrode is detected to obtain the resistance value between the inner container and the heating tube of the electric water heater.

2. The method of claim 1, wherein the method further comprises: The resistance value between the inner container and the heating tube is detected continuously for multiple times, if the resistance value detected each time is within a preset range, it is judged that the water level in the inner container is higher than the safe water level.

3. The method for testing an electric water heater according to claim 2, characterized in that, If the resistance value between the inner container and the heating tube is detected to be out of the preset range, it is judged that the water level in the inner container is lower than the safe water level, and the detection of the resistance value between the inner container and the heating tube is stopped.

4. The method of claim 1, wherein the method further comprises: After detecting the resistance value between the inner container and the heating tube, the detected resistance value is converted into an AD value, if the AD value is less than a preset value, it is judged that the water level in the inner container is higher than the safe water level.

5. The method of claim 1-4, wherein the method further comprises: Before the heating tube starts heating, the resistance value between the inner container and the heating tube is detected, if it is judged that the water level in the inner container is higher than the safe water level, the heating tube is controlled to start heating the water in the inner container.

6. A detection circuit of an electric water heater using the detection method according to any one of claims 1 to 5, characterized in that, It comprises: a resistance-capacitance circuit connected with a power supply; a voltage stabilizing circuit connected with the resistance-capacitance circuit and connected with an analog-to-digital converter; a protection circuit connected with the resistance-capacitance circuit.

7. The detection circuit for an electric water heater according to claim 6, characterized in that, The resistance-capacitance circuit comprises an electrical connector J1, the pin 1 of the electrical connector J1 is grounded, the pin 2 of the electrical connector J1 is connected to the first end of a resistor R11 through a resistor R14, a resistor R13, a resistor R12 and a capacitor C11 connected in series, and the second end of the resistor R11 is connected with the power supply.

8. The detection circuit of an electric water heater according to claim 7, wherein the detection circuit is configured to detect the presence of water in the tank by detecting the presence of a conductive object in the tank. The protection circuit comprises a triode N1, the collector of the triode N1 is connected with the first end of the resistor R11, the base of the triode N1 is connected to a pulse input signal PWM, and the emitter of the triode N1 is grounded.

9. The detection circuit of an electric water heater according to claim 7, wherein the detection circuit further comprises a second resistor connected in series with the first resistor and the second resistor has a resistance value greater than the resistance value of the first resistor. The voltage stabilizing circuit comprises a diode D1, the anode of the diode D1 is connected with the first end of the resistor R11, the cathode of the diode D1 is connected with the first end of a resistor R15, the second end of the resistor R15 is connected with the first end of a resistor R16, the first end of a capacitor C12 and the first end of a resistor R17, the second end of the resistor R17 is connected with the negative electrode of a voltage stabilizing tube ZD1, the first end of a capacitor C13 and an analog-to-digital converter, the second end of the resistor R16, the second end of the capacitor C12, the positive electrode of the voltage stabilizing tube ZD1 and the second end of the capacitor C13 are all grounded.

10. An electric water heater, characterised in that, It comprises: an inner container, the inner container is insulated from the heating tube; a detection circuit board provided with the detection circuit as claimed in any one of claims 6-9; a first electrode connected to the pin 2 of the electrical connector J1 through a wire, and a second electrode connected to the pin 1 of the electrical connector J1 through a wire.

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