Electric heating control circuit, and control method and apparatus, and heat pump heating unit

Abstract

Disclosed in the present application is an electric heating control circuit. The electric heating control circuit in the present application comprises: a power source module, a heating module, a first switch module and a control module, wherein the power source module is used for supplying power; the heating module is connected to the power source module, so as to heat a heated medium; the first switch module is disposed between the power source module and the heating module, and the first switch module is used for controlling the on / off of a circuit between the heating module and the power source module on the basis of an electrical signal; and the control module is electrically connected to the first switch module, and the control module is used for sending the electrical signal on the basis of a current or voltage measurement result between the power source module and the first switch module, or sending the electrical signal on the basis of the temperature of the heated medium in the heating module and the temperature of a heating wire of an electric heating tube. Thus, by means of a control module of the electric heating control circuit in the present application, when it is determined that a fault occurs during an electric heating process of a heating module, the control module can control, in a timely manner and on the basis of an electrical signal, a first switch module to be turned off, thereby achieving an electric heating protection effect.

Description

Electric heating control circuit, control method and device thereof, and heat pump heating unit

[0001] Priority information

[0002] This application claims priority and benefits of patent application No. 202410023198.9 filed with the State Intellectual Property Office of China on January 5, 2024, and claims priority and benefits of patent application No. 202420233030.6 filed with the State Intellectual Property Office of China on January 30, 2024, and the entire text of which is incorporated herein by reference. Technical Field

[0003] The present application relates to the field of heat pump heating, and in particular to an electric heating control circuit, a control method and a device thereof, and a heat pump heating unit. Background Art

[0004] As national requirements for energy efficiency and energy efficiency in electrical equipment continue to rise, heat pump heating is becoming increasingly common. However, when heat pumps are insufficient in extremely low temperatures, electric heating elements are often used as auxiliary heat sources. Because electric heating elements generate high power and current, they can be controlled using relays. However, this relay-based control method can easily lead to malfunctions in the heating element's heating process, resulting in unexpected problems. Summary of the Invention

[0005] In view of this, the present invention aims to solve at least one of the problems in the related art to a certain extent. To this end, the purpose of this application is to provide an electric heating control circuit, a control method and a device thereof, and a heat pump heating unit.

[0006] In certain embodiments, the present application provides an electric heating control circuit. The electric heating control circuit includes a power supply module, a heating module, a first switch module, and a control module. The power supply module is used to supply power; the heating module is connected to the power supply module to heat the heated medium; the first switch module is arranged between the power supply module and the heating module, and the first switch module is used to control the on-off of the circuit between the heating module and the power supply module according to an electrical signal; the control module is electrically connected to the first switch module, and the control module is used to send the electrical signal according to the current or voltage detection result between the power supply module and the first switch module, or send the electrical signal according to the temperature of the heated medium in the heating module and the temperature of the heating wire of the electric heating tube.

[0007] In some embodiments, the electric heating control circuit also includes: a second switch module, which is arranged between the power module and the first switch module, or between the heating module and the first switch module, and the second switch module is used to control the on and off of the circuit between the heating module and the power module; the control module includes a first temperature detection module, which is electrically connected to the first switch module and the second switch module respectively, and the first temperature detection module is used to detect the temperature of the heated medium. When the temperature reaches a first set value, the first electrical signal is output to the first switch module to control the disconnection of the circuit between the heating module and the power module; after the first temperature detection module outputs the first electrical signal, it continues to detect the temperature of the heated medium. When the temperature reaches a second set value, the second electrical signal is output to the second switch module to control the disconnection of the circuit between the heating module and the power module, wherein the second set value is greater than the first set value.

[0008] In certain embodiments, the first temperature detection module includes: a first detection unit and a second detection unit. The first detection unit is electrically connected to the first switch module, and is configured to output a first electrical signal to the first switch module when detecting that the temperature of the heated medium reaches the first set value, thereby disconnecting the circuit between the heating module and the power module; and the second detection unit is electrically connected to the second switch module, and is configured to output a second electrical signal to the second switch module when detecting that the temperature of the heated medium reaches the second set value after the first switch module outputs the first electrical signal, thereby disconnecting the circuit between the heating module and the power module.

[0009] In certain embodiments, the electric heating control circuit includes a plurality of second switch modules connected in series, and the second detection unit outputs different second electrical signals to control different second switch modules according to different second set values.

[0010] In some embodiments, the electric heating control circuit includes a plurality of second switch modules connected in series and a plurality of second detection units connected to the second switch modules, and the plurality of second detection units are respectively connected to the plurality of second switch modules in a one-to-one correspondence; the plurality of second detection units respectively output different second electrical signals, and when the plurality of second detection units output different second electrical signals, the corresponding second set values ​​are different.

[0011] In some embodiments, the electric heating control circuit also includes a third switch module, which is arranged between the power module and the second switch module, and the third switch module is used to control the on and off of the circuit between the heating module and the power module; the control module also includes a first current detection module, one end of the first current detection module is connected to the circuit between the heating module and the power module, and the other end of the first current detection module is electrically connected to the third switch module, and the first current detection module is used to output a third electrical signal to control the third switch module when detecting the presence of current in the circuit between the heating module and the power module after the second switch module outputs the second electrical signal, so as to control the circuit between the heating module and the power module to be disconnected.

[0012] In some embodiments, the first switch module, the second switch module, and the third switch module include one or more relays.

[0013] In some embodiments, the control module also includes a first voltage detection module, which includes at least one voltage detector, one of which is connected to both ends of a relay, and the voltage detectors in the first switch module and the second switch module are both electrically connected to the third switch module; the first voltage detection module is used to: after the first temperature detection module outputs the first electrical signal, when at least one of the voltage detectors detects that there is voltage at both ends of at least one of the relays in the first switch module, output a fourth electrical signal to control the second switch module to control the disconnection of the circuit between the heating module and the power supply module; after the first temperature detection module outputs the second electrical signal, when at least one of the voltage detectors detects that there is voltage at both ends of at least one of the relays in the second switch module, output a fifth electrical signal to control the third switch module to control the disconnection of the circuit between the heating module and the power supply module.

[0014] In some embodiments, the heating module includes an electric heating tube, the first temperature detection module is connected to the electric heating tube, and the first temperature detection module is also used to detect the temperature of the heating wire of the electric heating tube in real time; after the first temperature detection module outputs the first electrical signal, the first temperature detection module detects that the temperature of the heating wire rises by a preset value within a preset time, and outputs the second electrical signal to the second switch module to control the disconnection of the circuit between the heating module and the power supply module.

[0015] In some embodiments, the first temperature detection module is connected to the third switch module, and the first temperature detection module is further used to: after the first temperature detection module outputs a second electrical signal, detect that the temperature of the heating wire or the heated medium rises to a preset value within a preset time, and output a sixth electrical signal to the third switch module to control the disconnection of the circuit between the heating module and the power supply module.

[0016] In some embodiments, the electric heating control circuit also includes a prompt module, which is electrically connected to the first current detection module, the first voltage detection module and / or the first temperature detection module, respectively. The prompt module is used to: issue a temperature warning prompt of the heated medium when the first current detection module outputs the third electrical signal; issue a temperature warning prompt of the heated medium when the first voltage detection module outputs the fifth electrical signal; and issue a temperature warning prompt of the heated medium when the first temperature detection module outputs the sixth electrical signal.

[0017] In certain embodiments, the control module includes: a second current detection module and a software control module, the second current detection module is connected to the circuit between the power supply module and the first switch module, and the second current detection module is used to output a first detection result; the software control module is respectively connected to the second current detection module and the first switch module, and the software control module is used to send a seventh electrical signal based on the first detection result to control the disconnection of the first switch module.

[0018] In some embodiments, the second current detection module includes a current transformer, a shaping filter unit and a current calculation unit, the shaping filter unit is connected between the current transformer and the current calculation unit, and the shaping filter unit includes a first resistor, a shaping diode, a second resistor, a filter capacitor and a third resistor; the first end of the first resistor is respectively connected to the current transformer and the shaping diode, and the second end of the first resistor is grounded; the first end of the second resistor is connected to the shaping diode, and the second end of the second resistor is connected to the current calculation unit; the first end of the filter capacitor is respectively connected to the second resistor and the current calculation unit, and the second end of the filter capacitor is grounded; the first end of the third resistor is respectively connected to the second resistor and the current calculation unit, and the second end of the third resistor is grounded.

[0019] In some embodiments, the electric heating control circuit includes a second switch module, which is arranged between the power module and the first switch module, and the second switch module is also used to control the on and off of the circuit between the heating module and the power module according to an electrical signal; the software control module is connected to the second switch module, and the software control module is used to output an eighth electrical signal according to the first detection result to control the disconnection of the second switch module.

[0020] In some embodiments, the first switch module and the second switch module include one or more relays.

[0021] In some embodiments, the second current detection module is used to output a second detection result; and the software control module is further used to output a ninth electrical signal according to the second detection result to control the disconnection of the second switch module.

[0022] In certain embodiments, the control module includes a second temperature detection module, which is electrically connected to the software control module. The second temperature detection module is used to detect the temperature of the heated medium to send a first control signal to the software control module to output a tenth electrical signal to control the disconnection of the first switch module; or send a second control signal to the software control module to output an eleventh electrical signal to control the disconnection of the second switch module.

[0023] In certain embodiments, the heating module includes an electric heating tube, and the second temperature detection module is connected to the electric heating tube. After the software control module controls the disconnection of the first switch module, the second temperature detection module is used to detect the temperature of the heating wire of the electric heating tube to output the second control signal to the software control module to output a twelfth electrical signal to control the disconnection of the second switch module.

[0024] In some embodiments, the control module also includes a second voltage detection module, the second voltage detection module includes at least one voltage detector, one of the voltage detectors is connected to both ends of a relay, and the voltage detectors in the first switch module and the second switch module are both electrically connected to the software control module; the second voltage detection module is used to output a first electrical signal to the software control module to output a thirteenth electrical signal to control the disconnection of the second switch module.

[0025] In certain embodiments, the electric heating control circuit further includes a prompt module, which is electrically connected to the software control module and is configured to issue a fault prompt and a temperature warning prompt corresponding to the heated medium.

[0026] The present application also provides an electric heating control method based on the electric heating control circuit described in any one of the above embodiments. The electric heating control method includes: detecting the temperature of the heated medium through the first temperature detection module; when the temperature reaches the first set value, controlling the first temperature detection module to output the first electrical signal to the first switch module to control the circuit between the heating module and the power module to be disconnected; after the first temperature detection module outputs the first electrical signal, detecting the temperature of the heated medium through the first temperature detection module; when the temperature reaches the second set value, controlling the first temperature detection module to output the second electrical signal to the second switch module to control the circuit between the heating module and the power module to be disconnected, wherein the second set value is greater than the first set value.

[0027] In certain embodiments, the electric heating control method includes: after the second switch module outputs the second electrical signal, detecting whether there is current in the circuit between the heating module and the power supply module through the first current detection module; when the first current detection module detects that there is current in the circuit between the heating module and the power supply module, controlling the first current detection module to output a third electrical signal to control the third switch module to control the circuit between the heating module and the power supply module to be disconnected.

[0028] In some embodiments, the electric heating control method includes: detecting the temperature of the heating wire of the electric heating tube in the heating module through the first temperature detection module, and after the first temperature detection module outputs the first electrical signal, when the first voltage detection module detects that there is voltage at both ends of at least one of the relays in the first switch module, outputting a fourth electrical signal to control the second switch module to control the circuit between the heating module and the power supply module to be disconnected; after the first temperature detection module outputs the second electrical signal, when the first voltage detection module detects that there is voltage at both ends of at least one of the relays in the second switch module, outputting a fifth electrical signal to control the third switch module to control the circuit between the heating module and the power supply module to be disconnected.

[0029] In certain embodiments, the electric heating control method includes: after the first temperature detection module outputs the first electrical signal, the first temperature detection module detects that the temperature of the heating wire rises by a preset value within a preset time, and outputs a second electrical signal to the second switch module to control the disconnection of the circuit between the heating module and the power supply module; after the first temperature detection module outputs the second electrical signal, the first temperature detection module detects that the temperature of the heating wire rises by a preset value within a preset time, and outputs a sixth electrical signal to the third switch module to control the disconnection of the circuit between the heating module and the power supply module.

[0030] In certain embodiments, the electric heating control method includes: controlling the prompt module to issue a temperature warning prompt of the heated medium while the first current detection module outputs the third electrical signal; controlling the prompt module to issue a temperature warning prompt of the heated medium while the first voltage detection module outputs the fifth electrical signal; and controlling the prompt module to issue a temperature warning prompt of the heated medium while the first temperature detection module outputs the sixth electrical signal.

[0031] The present application also provides an electric heating control device, which includes the electric heating control circuit described in any one of the above embodiments or is used to implement the electric heating control method described in any one of the above embodiments.

[0032] The present application also provides a heat pump heating unit, which includes the electric heating control device described in the above embodiment.

[0033] The present application also provides a heating and ventilation equipment, which includes the heat pump heating unit described in the above embodiment.

[0034] Additional aspects and advantages of the present application will be given in part in the description below, and in part will become obvious from the description below, or will be learned through practice of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] The above and / or additional aspects and advantages of the present application will become apparent and easily understood from the following description of the embodiments in conjunction with the accompanying drawings, in which:

[0036] FIG1 is a schematic structural diagram of an electric heating control circuit according to certain embodiments of the present application;

[0037] FIG2 is a schematic diagram of the structure of an electric heating control circuit according to certain embodiments of the present application;

[0038] FIG3 is a schematic diagram of the structure of an electric heating control circuit according to certain embodiments of the present application;

[0039] FIG4 is a schematic diagram of the structure of an electric heating control circuit according to certain embodiments of the present application;

[0040] FIG5 is a schematic structural diagram of an electric heating control circuit according to certain embodiments of the present application;

[0041] FIG6 is a schematic structural diagram of an electric heating control circuit according to certain embodiments of the present application;

[0042] FIG7 is a schematic diagram of the structure of an electric heating control circuit according to certain embodiments of the present application;

[0043] FIG8 is a schematic structural diagram of an electric heating control circuit according to certain embodiments of the present application;

[0044] FIG9 is a schematic structural diagram of an electric heating control circuit according to certain embodiments of the present application;

[0045] FIG10 is a schematic structural diagram of an electric heating control circuit according to certain embodiments of the present application;

[0046] FIG11 is a schematic structural diagram of an electric heating control circuit according to certain embodiments of the present application;

[0047] FIG12 is a schematic diagram of the structure of an electric heating control circuit according to certain embodiments of the present application;

[0048] FIG13 is a schematic diagram of the structure of an electric heating control circuit according to certain embodiments of the present application;

[0049] FIG14 is a schematic structural diagram of an electric heating control circuit according to certain embodiments of the present application;

[0050] FIG15 is a schematic structural diagram of an electric heating control circuit according to certain embodiments of the present application;

[0051] FIG16 is a schematic diagram of the structure of an electric heating control circuit according to certain embodiments of the present application;

[0052] FIG17 is a schematic diagram of the structure of an electric heating control circuit according to certain embodiments of the present application;

[0053] FIG18 is a schematic structural diagram of an electric heating control circuit according to certain embodiments of the present application;

[0054] FIG19 is a flow chart of an electric heating control method according to certain embodiments of the present application;

[0055] FIG20 is a schematic structural diagram of an electric heating control device according to certain embodiments of the present application;

[0056] FIG21 is a flow chart of an electric heating control method according to certain embodiments of the present application;

[0057] FIG22 is a flow chart of an electric heating control method according to certain embodiments of the present application;

[0058] FIG23 is a flow chart of an electric heating control method according to certain embodiments of the present application. DETAILED DESCRIPTION

[0059] The embodiments of the present application are described in detail below, and examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present application, and should not be understood as limiting the present application.

[0060] In the description of this application, it should be understood that the terms "first" and "second" are used for descriptive purposes only and should not be understood to indicate or imply relative importance or implicitly specify the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the described features. In the description of this application, "plurality" means two or more, unless otherwise expressly and specifically defined.

[0061] In the description of this application, it should be noted that, unless otherwise expressly specified or limited, the terms "installed," "connected," and "connected" should be understood in a broad sense. For example, they can refer to fixed connections, detachable connections, or integral connections; they can refer to mechanical connections, electrical connections, or connections that can communicate with each other; they can refer to direct connections or indirect connections through an intermediate medium; they can refer to internal connectivity between two components or interactions between two components. Those skilled in the art will understand the specific meanings of the above terms in this application based on specific circumstances.

[0062] The disclosure below provides many different embodiments or examples for implementing different structures of the present application. In order to simplify the disclosure of the present application, the components and settings of specific examples are described below. Of course, these are merely examples and are not intended to limit the present application. In addition, the present application may repeat reference numbers and / or reference letters in different examples. Such repetition is for the purpose of simplicity and clarity and does not in itself indicate the relationship between the various embodiments and / or settings discussed.

[0063] The embodiments of the present application are described in detail below, and examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present application, and should not be understood as limiting the present application.

[0064] Please refer to Figure 1. The present application provides an electric heating control circuit 100. The electric heating control circuit 100 includes: a power module 10, a heating module 20, a first switch module 30 and a control module 40. The power module 10 is used to supply power. The heating module 20 is connected to the power module 10 to heat the heated medium. The first switch module 30 is arranged between the power module 10 and the heating module 20, and the first switch module 30 is used to control the on-off of the circuit between the heating module 20 and the power module 10 according to an electrical signal. The control module 40 is electrically connected to the first switch module 30, and the control module 40 is used to send an electrical signal based on the current or voltage detection result between the power module 10 and the heating module 20, or send an electrical signal based on the temperature of the heated medium in the heating module 20 and the heating wire temperature of the electric heating tube.

[0065] Specifically, the power module 10 is used to supply power. The power module 10 of the present application can be a single-phase power supply or a three-phase power supply, which is not limited here. The heating module 20 is connected to the power module 10 to heat the heated medium.

[0066] The first switch module 30 is disposed between the power module 10 and the heating module 20. The first switch module 30 is used to control the on / off of the circuit between the heating module 20 and the power module 10.

[0067] The control module 40 can be connected to the circuit between the power module 10 and the first switch module 30, thereby sending an electrical signal to the first switch module 30 based on the current or voltage detection results between the power module 10 and the first switch module 30. For example, when the current between the power module 10 and the first switch module 30 deviates significantly from the normal current value, it can be determined that the electric heating process of the heating module 20 has failed. The control module 40 can then send an electrical signal to the first switch module 30 to control the first switch module 30 to disconnect, thereby providing electrical heating protection.

[0068] The control module 40 can also be electrically connected to the heating module 20, thereby sending an electrical signal to the first switch module 30 based on the temperature of the heated medium in the heating module 20 and the temperature of the heating wire of the electric heating tube. When the temperature of the heated medium in the heating module 20 and the temperature of the heating wire of the electric heating tube are too high, it can also be determined that the electric heating process of the heating module 20 has failed. The control module 40 can send an electrical signal to the first switch module 30 to control the disconnection, thereby providing electrical heating protection.

[0069] In this way, the control module 40 of the electric heating control circuit 100 of the present application can send an electrical signal based on the current or voltage detection results between the power module 10 and the first switch module 30, and send an electrical signal based on the temperature of the heated medium in the heating module 20 and the temperature of the heating wire of the electric heating tube, to determine whether the electric heating process of the heating module 20 has failed. If it is determined that the electric heating process of the heating module 20 has failed, the control module 40 can promptly control the disconnection of the first switch module 30 based on the electrical signal, thereby providing electric heating protection.

[0070] Referring to Figures 2 and 3 , the present application provides an electric heating control circuit 100. The electric heating control circuit 100 further includes a second switch module 50, and the control module 40 includes a first temperature detection module 41. In this embodiment, the electric heating control circuit 100 includes a power module 10, a heating module 20, a first switch module 30, a second switch module 50, and a first temperature detection module 41.

[0071] The power module 10 is used for power supply. As shown in FIG4 , the power module 10 can be a three-phase power supply, with three phases L1 , L2 and L3 corresponding to the three-phase power supply providing power, or a single-phase power supply or other power supply, which is not limited here.

[0072] The heating module 20 is connected to the power module 10 to heat the heated medium. As shown in Figure 4, the heating module 20 can be, for example, an electric heating tube or other heating element, without limitation. The heated medium can be, for example, water or other liquids, or other heatable substances. This application uses water as the heated medium for illustration.

[0073] The first switch module 30 is disposed between the power module 10 and the heating module 20. The first switch module 30 is used to control the circuit between the heating module 20 and the power module 10. The first switch module 30 can be a switching element such as a relay. As shown in FIG4 , the first switch module 30 can include electric auxiliary heating control relays K1, K2, and K3.

[0074] As shown in Figure 2, the second switch module 50 is disposed between the power module 10 and the first switch module 30. Alternatively, as shown in Figure 3, the second switch module 50 is disposed between the heating module 20 and the first switch module 30. The second switch module 50 is used to control the circuit between the heating module 20 and the power module 10. The second switch module 50 can also be a switching element such as a relay. As shown in Figure 4, the second switch module 50 can include electric auxiliary thermal protection relays K4, K5, and K6.

[0075] The first switch module 30 may include one or more relays, and the second switch module 50 may also include one or more relays.

[0076] It is understood that the number of relays included in the first switch module 30 and the second switch module 50 of the present application is related to the number of power sources corresponding to the power module 10. If the power module 10 is a single-phase power source, the number of relays included in the first switch module 30 and the second switch module 50 can be one. If the power module 10 is a multi-phase power source, the number of relays included in the first switch module 30 and the second switch module 50 can be multiple. For example, when the power module 10 is a three-phase power source, the number of relays included in the first switch module 30 and the second switch module 50 can be three.

[0077] It should be noted that when the power supply module 10 of the present application is a single-phase power supply, the first switch module 30 and the second switch module 50 may also include multiple relays connected in series, so as to avoid an accident caused by adhesion of a relay in the first switch module 30 or the second switch module 50, resulting in continuous heating of the heating module 20.

[0078] It can be understood that the present application uses low-cost relays to replace the original expensive contactors to control the heating process of the heating module 20, which can reduce costs.

[0079] The first temperature detection module 41 is electrically connected to the first switch module 30 and the second switch module 50 respectively. The first temperature detection module 41 is used to detect the temperature of the heated medium. When the temperature reaches the first set value, the first temperature detection module 41 outputs a first electrical signal to the first switch module 30 to control the disconnection of the circuit between the heating module 20 and the power module 10. After the first temperature detection module 41 outputs the first electrical signal, it continues to detect the temperature of the heated medium. When the temperature reaches the second set value, it outputs a second disconnection signal to the second switch module 50 to control the disconnection of the circuit between the heating module 20 and the power module 10, wherein the second set value is greater than the first set value. The first temperature detection module 41 can be a thermocouple temperature sensor or other instrument, which is not limited here. The first temperature detection module 41 can be partially or completely placed in the heated medium.

[0080] The first set value may be a default temperature value. The first set value may also be a temperature value set according to different heated media. For example, when the heated medium is water, the first set value may be 58°C, 60°C, 61.5°C, 62°C, 62.5°C, 63.5°C, 64.8°C, 65°C, 66°C, or 68°C. Other values ​​are also possible and are not limited here. For example, when the heated medium is oil, the first set value may be 100°C.

[0081] The second set value can be a default temperature value. The second set value can also be set to a different temperature value based on the heated medium. For example, when the heated medium is water, the second set value can be 70°C, 71°C, 71.5°C, 72°C, 72.5°C, 73.5°C, 74.8°C, 75°C, 76°C, or 78°C. Other values ​​are also possible and are not limited here. For example, when the heated medium is oil, the second set value can be 110°C.

[0082] In addition, after the temperature of the heated medium reaches a first set value, the electric heating tube can be set to reheat the heated medium after the temperature of the heated medium drops. After the temperature of the heated medium reaches a second set value, the electric heating tube can be set to stop reheating the heated medium after the temperature of the heated medium drops.

[0083] The first electrical signal may be a voltage signal or a current signal, which is not limited here. The second electrical signal may also be a voltage signal or a current signal, which is not limited here.

[0084] It can be understood that after the first temperature detection module 41 outputs the first electrical signal, if the first temperature detection module 41 detects that the water temperature continues to rise, it means that there is adhesion in the relay in the first switch module 30, which causes the heating module to continue to heat the heated medium, causing the temperature of the heated medium to rise instead of fall.

[0085] Therefore, the temperature detection module of the present application can continue to detect the temperature of the heated medium after outputting the first electrical signal. When the temperature reaches a second set value greater than the first set value, it again outputs a second disconnection signal to the second switch module 50 to control the disconnection of the circuit between the heating module 20 and the power supply module 10, thereby ensuring that the heating module 20 will not continue to work, avoiding accidents caused by the heating module 20 continuing to heat the heated medium.

[0086] In this way, after the first temperature detection module 41 outputs the first electrical signal in the electric heating control circuit 100 of the present application, the temperature of the heated medium continues to be detected. When the temperature reaches the second set value, a second disconnection signal is output to the second switch module to control the disconnection of the circuit between the heating module and the power supply module. This can effectively prevent the relay in the first switch module from sticking, causing the heating module to continue heating and causing an accident.

[0087] In detail, referring to FIG. 5 , the first temperature detection module 41 may include a first detection unit 411 and a second detection unit 412 .

[0088] The first detection unit 411 is electrically connected to the first switch module 30. The first detection unit 30 is used to detect that the temperature of the heated medium reaches a first set value and output a first electrical signal to the first switch module 30 to control the circuit between the heating module 20 and the power module 10 to be disconnected.

[0089] The second detection unit 412 is electrically connected to the second switch module 50. The second detection unit 412 is configured to output a second electrical signal to the second switch module 50 when the temperature of the heated medium reaches a second set value after the first switch module 30 outputs the first electrical signal, thereby disconnecting the circuit between the heating module 20 and the power module 10.

[0090] Specifically, the first detection unit 411 may be an electronic temperature controller or other temperature controllers, which are not limited herein. The electronic temperature controller uses its internal circuit program to control the heating temperature of the heated medium, allowing the user to accurately adjust the heating temperature of the heated medium.

[0091] In other words, the first detection unit 411 can convert the collected temperature into a voltage signal or a current signal and output it to the first switch module. In other words, the first detection unit 411 can be a thermocouple temperature sensor, which can convert the temperature into a voltage signal and output it.

[0092] In detail, as shown in Figure 5, when the first detection unit 411 is an electronic water temperature controller, when the electronic water temperature controller detects that the water temperature reaches the first set value, for example, when the water temperature reaches 60°C, it can control the first switch module 30 to disconnect the circuit between the heating module 20 and the power supply module 10, that is, disconnect the electric auxiliary heating control relays K1, K2 and K3 in Figure 4, so that the water is reheated when the water temperature drops.

[0093] The second detection unit 412 can be a mechanical water temperature protector or other temperature sensor, without limitation. It is understood that after the first switch module 30 outputs the first electrical signal, if the mechanical water temperature protector detects that the water temperature continues to rise, it indicates that the control relays K1, K2, and K3 are sticking. When the water temperature reaches the second set value, the mechanical water temperature protector disconnects the auxiliary heating protection relays K4, K5, and K6, and the electric heating tube stops heating, thereby preventing accidents caused by the electric heating tube continuing to heat.

[0094] It should be noted that the first detection unit 411 and the second detection unit 412 of the present application may be two independent temperature sensors, or may be two independent detection units provided in one temperature sensor.

[0095] In this way, the first temperature detection module 41 of the present application can detect the temperature of the heated medium under different temperature conditions through two detection units to avoid the relay in the first switch module from sticking, causing the heating module to continue heating and causing accidents.

[0096] Please refer to Figure 6. In some embodiments of the present application, the electric heating control circuit 100 includes a plurality of second switch modules 50 connected in series in sequence. For example, Figure 5 includes a plurality of second switch modules 50, namely 501, 502 and 503. The second detection unit 412 outputs different second electrical signals to control different second switch modules 50 according to different second set values.

[0097] That is, the present application can include multiple second switch modules 50, i.e., multiple groups of relays as protective relays, and detect the temperature of the heated medium via a second detection unit 412. When the second detection unit 412 detects that the temperature reaches different second set values, different relay groups are controlled to disconnect in stages to prevent a relay in the first switch module 30 or the second switch module 50 from sticking, causing the heating module 20 to continue heating and causing accidents, thereby providing multi-stage protection for the electric heating process.

[0098] Taking the second switch module 50 including 3 relays forming a relay group and the second detection unit 412 as a mechanical water temperature protector as an example, that is, the electric heating control circuit 100 of the present application can be provided with multiple relay groups connected in series and a mechanical water temperature protector, and the mechanical water temperature protector is connected to multiple relay groups respectively.

[0099] As shown in Figure 6, the multiple second switch modules 50 are multiple relay groups, specifically relay group 501, relay group 502 and relay group 503 in Figure 6. Relay group 501, relay group 502 and relay group 503 are all electrically connected to the mechanical water temperature protector 4121. Among them, relay group 501 includes relays K4, K5 and K6, relay group 502 includes relays K7, K8 and K9, and relay group 503 includes relays K10, K11 and K12. When the mechanical water temperature protector 521 detects that the temperature of the heated medium reaches the second set value, which may be 70°C, for example, the mechanical water temperature protector 4121 outputs a second electrical signal to control the relay group 501 to disconnect. When the mechanical water temperature protector 4121 detects that the temperature of the heated medium continues to rise and reaches the second set value, which may be 74°C, for example, the mechanical water temperature protector 4121 outputs a second electrical signal to control the relay group 502 to disconnect. When the mechanical water temperature protector 4121 detects that the temperature of the heated medium continues to rise and reaches a second set value, for example, 79° C., the mechanical water temperature protector 4121 outputs a second electrical signal to control the relay group 503 to disconnect.

[0100] It is understandable that the greater the number of second switch modules 50 , the more effective it is to prevent one or more relays in the first switch module 30 or the second switch module 50 from sticking together, causing the heating module 20 to continue heating and cause accidents.

[0101] In this way, the present application can achieve multi-level protection for the process of the heating module 20 heating the heated medium by setting up multiple second switch modules 50 and one second detection unit 412, and can further ensure that the relay in the first switch module 30 or the second switch module 50 is prevented from sticking, causing the heating module 20 to continue heating and cause accidents.

[0102] Referring to FIG. 7 , in certain embodiments of the present application, the electric heating control circuit 100 includes a plurality of second switch modules 50 connected in series and a plurality of second detection units 412 connected to the second switch modules 50. The plurality of second detection units 412 are connected one-to-one to the plurality of second switch modules 50. The plurality of second detection units 412 output different second electrical signals, and when the plurality of second detection units 412 output different second electrical signals, the corresponding second set values ​​are different.

[0103] Specifically, the second switch module 50 includes three relays forming a relay group and the second detection unit 412 is a mechanical water temperature protector. For example, the electric heating control circuit 100 of the present application can be provided with multiple relay groups and multiple mechanical water temperature protectors connected in series, and the multiple mechanical water temperature protectors are connected one-to-one with the multiple relay groups. Compared with the method of connecting one mechanical water temperature protector to multiple relay groups, this connection method of connecting multiple mechanical water temperature protectors one-to-one with multiple relay groups makes the circuit connection clearer, the control instructions are not easily confused, and the on and off of a single relay group can be controlled by a single water temperature protector.

[0104] As shown in FIG7 , the plurality of second switch modules 50 are a plurality of relay groups, specifically relay group 504, relay group 505, and relay group 506 in FIG7 , and the plurality of second detection units 412 can be mechanical water temperature protectors 4122, 4123, and 4124. Relay group 504 is electrically connected to mechanical water temperature protector 4122, relay group 505 is electrically connected to mechanical water temperature protector 4123, and relay group 506 is electrically connected to mechanical water temperature protector 4124.

[0105] When the mechanical water temperature protector 4122 detects that the temperature of the heated medium has reached a second set value, for example, 70°C, the mechanical water temperature protector 4122 outputs a second electrical signal to control the relay group 504 to disconnect. When the mechanical water temperature protector 4123 detects that the temperature of the heated medium has reached a second set value, for example, 72°C, the mechanical water temperature protector 4123 outputs a second electrical signal to control the relay group 505 to disconnect. When the mechanical water temperature protector 4124 detects that the temperature of the heated medium has reached a second set value, for example, 78°C, the mechanical water temperature protector 4124 outputs a second electrical signal to control the relay group 506 to disconnect.

[0106] It can be understood that at this time, the more the number of second switch modules 50 and second detection units 412 is, the more it can ensure that one or more relays in the first switch module 30 or the second switch module 50 will not stick together, causing the heating module 20 to continue heating and cause accidents.

[0107] In this way, the present application can achieve multi-level protection for the process of the heating module 20 heating the heated medium by setting up multiple second switch modules 50 and multiple second detection units 412, which can further ensure that the relays in the first switch module 30 or the second switch module 50 are prevented from sticking, causing the heating module 20 to continue heating and cause accidents.

[0108] 8 and 9 , the electric heating control circuit 100 further includes a third switch module 60. The control module 40 further includes a first current detection module 42. The third switch module 60 is disposed between the power module 10 and the second switch module 30. The third switch module 60 is used to control the on / off state of the circuit between the heating module 20 and the power module 10.

[0109] The third switch module 60 may also include one or more relays. As shown in FIG9 , the third switch module 60 may include three relays, namely, electric auxiliary thermal protection relays K7 , K8 and K9 .

[0110] One end of the first current detection module 42 is connected to the circuit between the heating module 20 and the power module 10, and the other end of the first current detection module 42 is electrically connected to the third switch module 60. After the second switch module 60 outputs the second electrical signal, the first current detection module 42 is configured to output a third electrical signal to control the third switch module 60 to disconnect the circuit between the heating module 20 and the power module 10 when it detects the presence of current in the circuit between the heating module 20 and the power module 10.

[0111] It can be understood that if the first current detection module 42 detects that the current in each branch circuit between the heating module 20 and the power supply module 10 is not zero, that is, there is current in any circuit, that is, IL1≠0, or IL2≠0, or IL3≠0, it means that the electric auxiliary thermal protection relay K4, K5 or K6 is stuck. At this time, the first current detection module 42 can control the disconnection of the electric auxiliary thermal protection relays K7, K8, K9 to prevent the heating module 20 from continuously heating the heated medium and causing accidents.

[0112] That is, the present application detects the on-off state of the relay by detecting the current between the power module 10 and the heating module 20 to prevent accidents caused by the heating module 20 continuously heating the heated medium due to adhesion of the relay.

[0113] As shown in Figure 9, the first current detection module 42 may include a current transformer 421, a filter and rectifier unit 422, and a current detection unit 423. The current transformer 421 is connected to the current detection unit 423 via the filter and rectifier unit 422, and the current detection unit 423 may be electrically connected to the third switch module 60, thereby outputting a third electrical signal to the third switch module 60 to control the circuit between the heating module 20 and the power module 10 to be disconnected.

[0114] The current transformer 421 converts the primary side high current into the secondary side low current for measurement. As shown in FIG9 , the current transformer 421 can be directly set in the circuit between the power module 10 and the third switch module 60 .

[0115] The filtering and rectifying unit 422 operates on the principle of rectification and filtering, based on the different responses of circuit components to voltage, current, frequency, and other characteristics. This filtering and smoothing process is performed on AC signals and DC signals, ensuring that the current detection unit 423 can obtain relatively accurate current detection results. Referring to Figure 9 , the filtering and rectifying unit 422 may include a filter capacitor E1, a filter capacitor E2, a rectifier diode D1, a rectifier diode D2, and multiple resistors R connected in series.

[0116] The first current detection module 42 can be connected only to the power supply branch corresponding to any one, two, or three phases of the three-phase power supply, thereby detecting whether the relays on each branch are sticking. As shown in Figure 8, only one first current detection module 42 can be connected to each of the circuits corresponding to phases L1 and L2 of the three-phase power supply, thereby detecting the current of relays K1, K2, K4, and K5 in the circuits corresponding to phases L1 and L2, thereby preventing accidents caused by the heating module 20 continuously heating the heated medium.

[0117] Referring to FIG. 10 , the control module 40 may further include a first voltage detection module 43. The first voltage detection module 43 includes at least one voltage detector, one voltage detector being connected in parallel across a relay. The voltage detectors in the first switch module 30 and the second switch module 50 are both electrically connected to the third switch module 60.

[0118] The first voltage detection module 43 is configured to output a fourth electrical signal to control the second switch module 50 to disconnect the circuit between the heating module 20 and the power module 10 when at least one voltage detector detects a voltage across at least one relay in the first switch module 30 after the first temperature detection module 41 outputs the first electrical signal. The fourth electrical signal may be a voltage signal or a current signal.

[0119] The first voltage detection module 43 is further configured to output a fifth electrical signal to control the third switch module 30 to disconnect the circuit between the heating module 20 and the power module 10 when at least one voltage detector detects a voltage across at least one relay in the second switch module 50 after the first temperature detection module 41 outputs the second electrical signal. The fifth electrical signal may be a voltage signal or a current signal.

[0120] It is understandable that if, after the relay receives the disconnect signal and disconnects, the voltage detector detects voltage across the relay, it indicates that the relay has become stuck, which may cause the heating module 20 to continue heating the heated medium and cause an accident. Therefore, the present application uses a voltage detector to detect in real time whether each relay has become stuck after disconnection, ensuring the electrical safety of the heating module 20.

[0121] In this way, the electric heating control circuit 100 of the present application can also detect whether the relays in the first switch module 30 and the second switch module 50 are sticking through the first voltage detection module 43, so that corresponding protective measures can be taken automatically and in time to prevent accidents caused by the heating module 20 continuing to heat the heated medium due to the adhesion of the relay.

[0122] In one embodiment of the present application, the heating module 20 includes an electric heating tube, and the first temperature detection module 41 is connected to the electric heating tube. The first temperature detection module 41 is also used to detect the temperature of the heating wire of the electric heating tube in real time. After the first temperature detection module 41 outputs a first electrical signal, if the first temperature detection module 41 detects that the temperature of the heating wire has risen by a preset value within a preset time, the first temperature detection module 41 outputs a second electrical signal to the second switch module 50 to control the disconnection of the circuit between the heating module 20 and the power module 10. The second electrical signal can be a voltage signal or a current signal.

[0123] The preset time may be, for example, 2s, 3s, 4s, 5s, 5.5s, 5.6s, 5.8s, 6s, 7s, or 7.5s, without limitation. The preset value may be, for example, 1°C, 1.5°C, 1.8°C, 2°C, 2.4°C, 2.8°C, 3°C, 4°C, 5°C, or 6°C, without limitation.

[0124] Understandably, if after the relay receives the disconnect signal and disconnects, the temperature of the heating wire of the electric heating tube is still rising when detected by the first temperature detection module 41, it indicates that the relay has become stuck, which may cause the heating module 20 to continue heating the heated medium and cause an accident. Therefore, the present application uses the first temperature detection module 41 to detect the temperature of the heating wire of the electric heating tube to detect whether the relay in the first switch module 30 has become stuck after disconnection, thereby ensuring the electrical safety of the heating module 20.

[0125] In this way, the electric heating control circuit 100 of the present application can also detect whether the relay in the first switch module 30 is stuck through the first temperature detection module 41, so that corresponding protective measures can be taken automatically and in time to prevent the heating module 20 from continuously heating the heated medium due to the adhesion of the relay and causing accidents.

[0126] In another embodiment of the present application, the first temperature detection module 41 is connected to the third switch module 60. The first temperature detection module 41 is further configured to continue detecting the heating wire temperature after the first temperature detection module 41 outputs the second electrical signal. Upon detecting that the heating wire temperature rises again by a preset value within a preset time, the first temperature detection module 41 outputs a sixth electrical signal to the third switch module 60 to disconnect the circuit between the heating module 20 and the power module 10. The sixth electrical signal may be a voltage signal or a current signal.

[0127] The preset time may be, for example, 3s, 4.2s, 5.3s, 5.5s, 5.6s, 5.8s, 6s, 6.1s, 7s, or 8s, without limitation. The preset value may be, for example, 1°C, 1.4°C, 1.9°C, 2°C, 2.5°C, 2.9°C, 3°C, 4°C, 5.5°C, or 7°C, without limitation.

[0128] It is understandable that if the temperature of the heating wire of the electric heating tube is still rising after the relay receives the disconnect signal and disconnects, it means that the relay has stuck, which may cause the heating module 20 to continue heating the heated medium and cause an accident. Therefore, the present application uses the first temperature detection module 41 to detect the temperature of the heating wire of the electric heating tube to detect whether the relay in the second switch module 50 has stuck after disconnecting, thereby ensuring the safety of the heating module 20.

[0129] In this way, the electric heating control circuit 100 of the present application can also detect again whether the relay in the second switch module 50 is stuck through the first temperature detection module 41, so that corresponding protection measures can be taken automatically and in time to prevent accidents caused by the heating module 20 continuing to heat the heated medium due to the adhesion of the relay.

[0130] Please refer to Figures 11 and 12. In some embodiments of the present application, the electric heating control circuit 100 further includes a prompt module 70, which is electrically connected to the first current detection module 42, the first voltage detection module 43 and the first temperature detection module 41 respectively.

[0131] The prompt module 70 is configured to issue a temperature warning of the heated medium simultaneously with the output of the third electrical signal by the first current detection module 42. The prompt module 70 is further configured to issue a temperature warning of the heated medium simultaneously with the output of the fifth electrical signal by the first voltage detection module 43. The prompt module 70 is further configured to issue a temperature warning of the heated medium simultaneously with the output of the sixth electrical signal by the first temperature detection module 41.

[0132] The temperature warning prompt can be provided by voice prompt, red light, or other means, which are not limited here. As shown in FIG11 or FIG12 , the prompt module 70 can be electrically connected to the current detection unit 423 in the first current detection module 42 .

[0133] In this way, while the first current detection module 42 outputs the third electrical signal, the prompt module 70 can issue a temperature warning prompt for the heated medium. After receiving the prompt, the user can take corresponding power-off protection measures to prevent the heating module 20 from continuously heating the heated medium and causing accidents.

[0134] Referring to FIG. 13 , the present application further provides an electric heating protection circuit 100 . The control module 40 includes a second current detection module 44 and a software control module 45 . Specifically, in this embodiment, the electric heating protection circuit 100 includes a power module 10 , a heating module 20 , a first switch module 30 , a second current detection module 44 , and a software control module 45 .

[0135] The power module 10 is used to supply power. The power module 10 of the present application can be a single-phase power supply or a three-phase power supply, which is not limited here. The heating module 20 is connected to the power module 10 to heat the heated medium.

[0136] The first switch module 30 is disposed between the power module 10 and the heating module 20. The first switch module 30 is used to control the on / off of the circuit between the heating module 20 and the power module 10.

[0137] The second current detection module 44 is connected to the circuit between the power module 10 and the first switch module 30. The second current detection module 44 is configured to output a first detection result. Specifically, after the first switch module 30 is closed, the second current detection module 44 outputs the first detection result if it detects that the current in the circuit between the power module 10 and the first switch module 30 has not reached a target current value within a first preset time.

[0138] The first preset time may be, for example, 1S, 1.1S, 1.2S, 1.3S, 1.4S, 2S, 3S, 3.5S, 4S, 4.1S or other values, which are not limited here.

[0139] The target current value can be, for example, a pre-set current value that enables the heating module 20 to heat normally, such as 18A, 18.5A, 19A, 20A, 21A, 22A, 23A, 23.5A, 24A, 25A or other values, which are not limited here.

[0140] The software control module 45 is connected to the second current detection module 44 and the first switch module 30, respectively. The software control module 45 is configured to generate a seventh electrical signal based on the first detection result to control the opening of the first switch module 30. In other words, the first detection result can be transmitted to the software control module 45 in the form of the seventh electrical signal. The software control module 45 is also configured to control the closing of the first switch module 30 when electric heating begins.

[0141] It is understandable that when the electric heating process of the heating module 20 begins, the software control module 45 will automatically issue a closing instruction to control the first switch module 30 to close, so that the heating module 20 and the power module 10 are powered on to start electric heating.

[0142] After the first switch module 30 is closed, when the second current detection module 44 detects that the current of the circuit between the power module 10 and the first switch module 30 reaches the target current value within the first preset time and outputs the first detection result, it can be determined that the electric heating process of the heating module 20 is normal at this time.

[0143] Conversely, after the first switch module 30 is closed, when the second current detection module 44 detects that the current in the circuit between the power module 10 and the first switch module 30 has not reached the target current value within the first preset time and outputs a first detection result, it can be determined that a fault has occurred in the electric heating process of the heating module 20. If the first switch module 30 is continued to be closed to provide power to the heating module 20 through the power module 10, causing the heating module 20 to perform the electric heating process, the fault may cause an electric heating accident or damage the heating module 20. Therefore, the present application controls the second current detection module 44 to output the first detection result to the software control module 45, and the software control module 45 controls the disconnection of the first switch module 30 based on the first detection result, thereby avoiding accidents caused by electric heating failures.

[0144] In this way, when the second current detection module 44 detects that the current in the circuit between the power module 10 and the first switch module 30 has not reached the target current value within the first preset time, the present application determines that the electric heating process of the heating module 20 has failed. The second current detection module 44 outputs the first detection result to the software control module 45 to send a seventh electrical signal to control the disconnection of the first switch module 30, thereby playing a role in electric heating protection.

[0145] Referring to Figure 14 , the electric heating protection circuit 100 further includes a second switch module 50. The second switch module 50 is disposed between the power module 10 and the first switch module 30. The second switch module 50 is also configured to control the connection and disconnection of the circuit between the heating module 20 and the power module 10 based on the electrical signal. The software control module 45 is connected to the second switch module 50 and is further configured to output an eighth electrical signal based on the first detection result to disconnect the second switch module 50.

[0146] The first switch module 30 and the second switch module 50 include one or more relays. As shown in FIG3 , when the power module 10 is a three-phase power supply, the first switch module 30 and the second switch module 50 each include three relays. The first switch module 30 includes relays K1, K2, and K3, and the second switch module 50 includes relays K4, K5, and K6.

[0147] It can be understood that the first switch module 30 can be a control relay group in the electric heating protection circuit 100. The working principle of the control relay is that the user sets a maximum temperature required for heating the heated medium, for example, 60°C. When the set temperature is reached, the software control module 45 will issue a disconnection instruction to control the disconnection relay to stop the electric heating process when the set temperature is reached.

[0148] The second switch module 50 may be a protection relay group in the electric heating protection circuit 100. That is, when the software control module 45 controls the disconnection of the first switch module 30 based on the first detection result, it also controls the disconnection of the second switch module 50. This can prevent accidents during the electric heating process caused by the first switch module 30 becoming stuck when it needs to be disconnected. In other words, the second switch module 50 can provide further protection.

[0149] In one embodiment, when the second current detection module 44 detects that the current in the circuit between the power module 10 and the first switch module 30 has not reached the target current value within a first preset time and outputs a first detection result, the software control module 45 can simultaneously issue a control instruction to simultaneously control the disconnection of the first switch module 30 and the second switch module 50 to ensure that the path between the heating module 20 and the power module 10 is disconnected in time to avoid a series of problems caused by the fault.

[0150] Referring to Figure 15 , in certain embodiments of the present application, the second current detection module 44 is further configured to output a second detection result. Specifically, after the first switch module 30 is disconnected, the second current detection module 44 detects that the current in the circuit between the power module 10 and the first switch module 30 has not decreased to a first preset threshold value within a first predetermined time or has not decreased to zero within a second predetermined time, and outputs the second detection result, where the first predetermined time is less than the second predetermined time. The software control module 45 is configured to output a ninth electrical signal based on the second detection result to control the disconnection of the second switch module 50.

[0151] The first predetermined time is a shorter time, such as 1 second, 2 seconds, 3 seconds, 4 seconds, 5 seconds, 6 seconds, 7 seconds, 8 seconds, 9 seconds or 10 seconds, which is not limited here.

[0152] The specific current value of the first preset threshold value may be, for example, 10% of the rated current of the heating module 20 , or 11% of the rated current of the heating module 20 , or other values, which are not limited herein.

[0153] The first predetermined time is a longer time, for example, 20 seconds, 25 seconds, 28 seconds, 30 seconds, 32 seconds, 35 seconds, 39 seconds, 40 seconds, 50 seconds or 60 seconds, which is not limited here.

[0154] It is understandable that in certain embodiments in which the software control module 45 does not control the disconnection of the second switch module 50 based on the first detection result after the first switch module 30 is disconnected, the electric heating protection circuit 100 of the present application can also determine whether the first switch module 30 is stuck by detecting, through the second current detection module 44, whether the current in the circuit between the power module 10 and the first switch module 30 decreases to a first preset threshold value within a first predetermined time or decreases to zero within a second predetermined time. Thus, when current exists in the circuit between the power module 10 and the first switch module 30, it is determined that the first switch module 30 is stuck. At this time, the second current detection module 44 can output the second detection result to the software control module 45, so as to disconnect the second switch module 50 based on the second detection result, thereby ensuring that the circuit between the heating module 20 and the power module 10 is disconnected, and avoiding accidents in the electric heating process caused by the sticking of the first switch module 30.

[0155] Specifically, referring to FIG15 , when the power module 10 is a three-phase power supply, it may include L1-phase, L2-phase, and L3-phase power supply branches, each electrically connected to the heating module 20. The presence of current in the circuit between the power module 10 and the first switch module 30 may refer to the presence of current in any one or more circuits connected to the L1-phase, L2-phase, and L3-phase in FIG2 .

[0156] The second current detection module 44 may specifically include the current transformer 441 (CT1) and the current transformer 442 (CT2) shown in FIG15 , a shaping filter unit 443 connected to the current transformer, and a current calculation unit 444 connected to the shaping filter unit 443. The shaping filter unit 443 includes a first resistor (R1 or R4 in FIG3 ), a shaping diode (D1 and D2 in FIG3 ), a second resistor (R2 or R5 in FIG3 ), a filter capacitor (E1 and E2 in FIG3 ), and a third resistor (R3 or R6 in FIG3 ). The first end of the first resistor is connected to the current transformer 42 and the shaping diode, respectively, and the second end of the first resistor is grounded. The first end of the second resistor is connected to the shaping diode, and the second end of the second resistor is connected to the current calculation unit 444. The first end of the filter capacitor is connected to the second resistor and the current calculation unit 444, respectively, and the second end of the filter capacitor is grounded. The first end of the third resistor is connected to the second resistor and the current calculation unit, respectively, and the second end of the third resistor is grounded.

[0157] In detail, the current value calculation method of the two branches L1 and L2 in the three-phase power supply of the present application can be specifically as follows:

[0158] Assume that the transformation ratio of current transformers CT1 and CT2 is N, the output voltage of CT1 is V_CT1, the output voltage of CT2 is V_CT1, the L1 phase current is I1, and the L2 phase current is I2:

[0159] Assume that the output voltage of the current transformer CT1 filter circuit is V_AD1, the output voltage of the current transformer CT2 filter circuit is V_AD2, and the voltage drop of the diode (D1 or D2) is VF:

[0160] Arranged:

[0161] The equations of I1 and I2 can be calculated by the current calculation unit 42 to obtain I1 and I2, which are 0. After the first switch module 30 has been disconnected, if either I1 or I2 cannot drop to 10% of the rated current of the heating module 20 or both I1 and I2 cannot drop to 10% of the rated current of the heating module 20 within a short period of time, such as 2 seconds, 3 seconds, or 5 seconds, or if either I1 or I2 cannot drop to 0 or both I1 and I2 cannot drop to 0 within a long period of time, such as 20 seconds, 40 seconds, or 60 seconds, it indicates that the first switch module 30 is stuck. Therefore, at this time, the second current detection module 44 can output the second detection result to the software control module 45 to control the disconnection of the second switch module 50, ensuring that the circuit between the heating module 20 and the power module 10 is disconnected, thereby avoiding accidents in the electric heating process caused by the sticking of the first switch module 30.

[0162] It should be noted that the presence of current in any one or more circuits connected to the L1, L2, and L3 phases can also be determined by the fact that current continues to exist in any one of the circuits connected to the L1, L2, and L3 phase power supplies for a period of time after the first switch module 30 is disconnected, indicating that the first switch module 30 is stuck. For example, within 3 seconds after the first switch module 30 is disconnected, if the second current detection module 44 detects that current continues to exist in any one or more circuits connected to the L1, L2, and L3 phase power supplies for 3 seconds, that is, the current in the three circuits is not zero within 3 seconds, such as if the current value in the three circuits remains at 2A or other values ​​within 3 seconds, then the first switch module 30 is stuck.

[0163] Referring to Figures 16 and 17 , in one embodiment of the present application, the control module 40 further includes a second temperature detection module 46. The second temperature detection module 46 is electrically connected to the software control module 45. The second temperature detection module 46 is configured to detect the temperature of the heated medium and to send a first control signal to the software control module 45 to output a tenth electrical signal to control the disconnection of the first switch module 30; or to send a second control signal to the software control module 45 to output an eleventh electrical signal to control the disconnection of the second switch module 30.

[0164] Specifically, when the second temperature detection module 46 detects that the temperature of the heated medium has reached a first set value, it sends a first control signal to the software control module 45 to output a tenth electrical signal to control the disconnection of the first switch module 30. After the second temperature detection module 46 detects that the temperature of the heated medium has reached the first set value, it continues to detect the temperature of the heated medium. When the temperature of the heated medium reaches a second set value, it sends a second control signal to the software control module 45 to output an eleventh electrical signal to control the disconnection of the second switch module 50. The second set value is greater than the first set value.

[0165] The first control signal and the second control signal may be voltage signals or current signals, which are not limited here.

[0166] The values ​​of the first set value and the second set value are related to the type of the heated medium. Different heated media have different corresponding first set values ​​and second set values. When the heated medium is water, the first set value can be, for example, 58°C, 60°C, 62°C, 62.5°C, 65°C, 66°C, 67°C, 68°C, 69°C or 70°C, without limitation. The second set value can be, for example, 68°C, 70°C, 72°C, 72.5°C, 75°C, 76°C, 77°C, 78°C, 79°C or 80°C, without limitation. In a specific embodiment, when the heated medium is water, the first set value can be 60°C and the second set value can be 70°C.

[0167] It is understood that the first set value can be the target temperature that the heated medium normally needs to reach during heating, while the second set value can be the higher temperature detected after the heated medium reaches the target temperature, resulting from continued heating of the heated medium due to adhesion of the first switch module 30. Therefore, when the second temperature detection module 46 detects that the temperature of the heated medium has reached the second set value, it can send a second control signal to the software control module 45, thereby controlling the second switch module 50 to disconnect, thereby preventing safety accidents during the electrical heating process of the heating module 20 caused by adhesion of the first switch module 30.

[0168] In this way, the present application can detect that the temperature of the heated medium reaches a first set value through the second temperature detection module 46, and then send a first control signal to the software control module 45 to control the first switch module 30 to accurately control the target heating temperature of the heated medium. After the first switch module 30 is disconnected, the second temperature detection module 46 sends a second control signal to the software control module 45 when the temperature of the heated medium continues to increase to a second set value, thereby preventing safety accidents during the electrical heating process of the heating module 20 due to adhesion of the first switch module 30.

[0169] In another embodiment of the present application, the heating module 20 includes an electric heating tube, and the second temperature detection module 46 is connected to the electric heating tube. After the software control module 45 controls the disconnection of the first switch module 30, the second temperature detection module 46 is used to detect the heating wire temperature of the electric heating tube to output a second control signal to the software control module 45 to output a twelfth electrical signal to control the disconnection of the second switch module 50.

[0170] Specifically, after the software control module 45 controls the disconnection of the first switch module 30, the second temperature detection module 46 detects that the temperature of the heating wire rises by a preset value within a second preset time, and outputs a second control signal to the software control module 45 to output a twelfth electrical signal to control the disconnection of the second switch module 50.

[0171] The second preset time may be, for example, 2S, 3S, 3.5S, 4S, 4.5S, 5S, 5.1S, 5.5S, 6S or 6.5S, which is not limited here.

[0172] The preset value may be, for example, 1°C, 2°C, 2.5°C, 3°C, 3.5°C, 4°C, 4.5°C, 5°C, 5.1°C or 6°C, without limitation herein.

[0173] It is understood that if, after the software control module 45 controls the disconnection of the first switch module 30, the second temperature detection module 46 still detects that the temperature of the heating wire continues to rise by a preset value within the second preset time, it indicates that the first switch module 30 has become stuck, causing the heating module 20 to continue heating the heated medium. Therefore, at this time, the second temperature detection module 46 can also send a second control signal to the software control module 45 to control the disconnection of the second switch module 50. In this way, if the first switch module 30 becomes stuck, the path between the heating module 20 and the power module 10 is disconnected, thereby preventing safety accidents caused by continued electric heating.

[0174] In this way, the electric heating protection circuit 100 of the present application can also detect the temperature of the heating wire of the electric heating tube through the second temperature detection module 46, and then determine whether the first switch module 30 is stuck. When it is determined that the first switch module 30 is stuck, the second switch module 50 is controlled to be disconnected to avoid safety accidents caused by continuous electric heating.

[0175] In another embodiment of the present application, the electric heating protection circuit 100 further includes a second voltage detection module. The second voltage detection module includes at least one voltage detector. One voltage detector is connected to both ends of a relay, and the voltage detectors in the first switch module 30 and the second switch module 50 are both electrically connected to the software control module 45. The second voltage detection module is configured to output a first electrical signal to the software control module 45, which in turn outputs a thirteenth electrical signal to control the disconnection of the second switch module 50.

[0176] Specifically, after the software control module 45 controls the disconnection of the first switch module 30, at least one voltage detector detects that the voltage across at least one relay in the first switch module 30 has not dropped to the second preset threshold within a third predetermined time or has not dropped to zero within a fourth predetermined time, and outputs a first electrical signal to the software control module 45 to control the disconnection of the second switch module 50, wherein the third predetermined time is less than the fourth predetermined time.

[0177] The third predetermined time is a shorter time, such as 1 second, 2 seconds, 3 seconds, 4 seconds, 6 seconds, 7 seconds, 8 seconds, 9 seconds, 10 seconds or 11 seconds, which is not limited here.

[0178] The specific current value of the second preset threshold value may be, for example, 10% of the rated voltage of the heating module 20 , or 12% of the rated voltage of the heating module 20 , or other values, which are not limited herein.

[0179] The fourth predetermined time is a longer time, for example, 21 seconds, 23 seconds, 27 seconds, 31 seconds, 33 seconds, 35 seconds, 38 seconds, 40 seconds, 50 seconds or 60 seconds, which is not limited here.

[0180] It is understandable that the electric heating protection circuit 100 of the present application can also detect the voltage of one or more relays in the first switch module 30 to determine whether the relays in the first switch module 30 are stuck based on the voltage.

[0181] In this way, the voltage protection circuit 100 of the present application can output a first electrical signal to the software control module 45 to output a thirteenth electrical signal to control the disconnection of the second switch module 50 when the voltage detector detects that the voltage at both ends of at least one relay of the first switch module 30 has not dropped to the second preset threshold within the third predetermined time or has not dropped to zero within the fourth predetermined time, so as to ensure that the path between the heating module 20 and the power supply module 10 is disconnected in time to avoid accidents of electric heating caused by relay adhesion.

[0182] 18 , in certain embodiments of the present application, the electric heating protection circuit 100 may further include a prompt module 80. The prompt module 80 is electrically connected to the software control module 45. The prompt module 80 is configured to issue a fault prompt and a temperature warning prompt corresponding to the heated medium.

[0183] Specifically, the prompt module 80 is configured to issue a fault prompt simultaneously with the software control module 45 controlling the disconnection of the first switch module 30. This fault prompt can be provided in the form of an audio or text message, a flashing light, or other methods, without limitation. The audio or text message can include the following: "Your electric heating device has experienced a heating failure. Please promptly inspect and repair it!"

[0184] Furthermore, when the software control module 45 receives the second control signal and / or the second detection result to control the disconnection of the second switch module 50, the prompt module 90 is further configured to issue a temperature warning corresponding to the heated medium. This temperature warning can be provided in the form of an audio or text message, a flashing light, or other methods, without limitation. The fault warning provided in the form of an audio or text message can include the message "The temperature of the heated medium in your electrically heated system is too high. Please note!"

[0185] In this way, the electric heating protection circuit 100 of the present application can prompt the user through the prompt module 80 whether a fault occurs during the electric heating process or whether the heating temperature is too high, so that the user can take corresponding protective measures or inspection measures in time to improve the safety of the electric heating process.

[0186] The above description is about the specific structure of the electric heating control circuit 100 . The following describes the electric heating control method implemented based on the electric heating control circuit 100 .

[0187] Referring to FIG. 19 , the present application provides an electric heating control method based on the electric heating control circuit 100 described in any of the above embodiments. The electric heating control method includes:

[0188] 01: Detect the temperature of the heated medium through the first temperature detection module;

[0189] 03: When the temperature reaches the first set value, the first temperature detection module is controlled to output a first electrical signal to the first switch module to control the circuit between the heating module and the power module to be disconnected;

[0190] 05: After the first temperature detection module outputs the first electrical signal, the temperature of the heated medium is detected by the first temperature detection module; and

[0191] 07: When the temperature reaches a second set value, the first temperature detection module is controlled to output a second electrical signal to the second switch module to control the circuit between the heating module and the power module to be disconnected, wherein the second set value is greater than the first set value.

[0192] 20 , the present application further provides an electric heating control device 200. The electric heating control device 200 includes the electric heating control circuit 100 described in the above embodiment.

[0193] Steps 01, 03, 05 and 07 can be implemented by the electric heating control device 200, that is, the electric heating control device 200 is used to: detect the temperature of the heated medium through the first temperature detection module; when the temperature reaches the first set value, control the first temperature detection module to output a first electrical signal to the first switch module to control the circuit between the heating module and the power module to be disconnected; after the first temperature detection module outputs the first electrical signal, detect the temperature of the heated medium through the first temperature detection module; when the temperature reaches the second set value, control the first temperature detection module to output a second electrical signal to the second switch module to control the circuit between the heating module and the power module to be disconnected, wherein the second set value is greater than the first set value. The specific structure of the electric heating control circuit 100 is as described above and will not be repeated here. The first set value and the second set value are as described above and will not be repeated here.

[0194] Specifically, after the circuits of the heating module 20 and the power module 10 are connected, the heating module 20 electrically heats the heated medium, and the temperature of the heated medium gradually increases. At this time, the temperature of the heated medium is first detected in real time by the first temperature detection module 41. When the temperature reaches a first set value, the first temperature detection module 41 is controlled to output a first electrical signal to the first switch module 30 to control the circuit between the heating module 20 and the power module 10 to be disconnected. In other words, after receiving the first electrical signal, the first switch module 30 can control the relay within the first switch module 30 to disconnect, thereby controlling the circuit between the heating module 20 and the power module 10 to be disconnected.

[0195] Understandably, if the relay within the first switch module 30 is not sticking after the first switch module 30 receives the first electrical signal, the circuit between the heating module 20 and the power module 10 is disconnected, and the temperature of the heated medium will drop. Therefore, if the temperature of the heated medium rises instead of falling after the first switch module 30 receives the first electrical signal, it is determined that the relay within the first switch module 30 is sticking.

[0196] Therefore, after the first temperature detection module 41 outputs the first electrical signal and the temperature of the heated medium continues to rise and reaches the second set value, the first temperature detection module 41 is controlled to output the second electrical signal to the second switch module 30, so that the circuit between the heating module 20 and the power module 10 is disconnected, which can avoid a relay in the first switch module 30 from sticking, causing the heating module 20 to continue heating and causing an accident.

[0197] In this way, the electric heating control method of the present application can continue to detect the temperature of the heated medium after the first temperature detection module 41 outputs the first electrical signal. When the temperature reaches a second set value greater than the first set value, it again outputs a second disconnection signal to the second switch module 50 to control the disconnection of the circuit between the heating module 20 and the power supply module 10, thereby ensuring that the heating module 20 will not continue to work, avoiding accidents caused by the heating module 20 continuing to heat the heated medium.

[0198] Referring to FIG. 21 , the electric heating control method includes:

[0199] 02: After the second switch module outputs the second electrical signal, the first current detection module detects whether there is current in the circuit between the heating module and the power module; and

[0200] 04: When the first current detection module detects that there is current in the circuit between the heating module and the power module, the first current detection module is controlled to output a third electrical signal to control the third switch module to control the circuit between the heating module and the power module to be disconnected.

[0201] Referring to FIG19 , steps 02 and 04 can also be implemented by the electric heating control device 200. That is, the electric heating control device 200 is configured to, after the second switch module outputs the second electrical signal, detect whether current exists in the circuit between the heating module and the power module via the first current detection module; and when the first current detection module detects that current exists in the circuit between the heating module and the power module, control the first current detection module to output a third electrical signal to control the third switch module, thereby disconnecting the circuit between the heating module and the power module.

[0202] Specifically, if the first current detection module 42 detects that the current in each branch circuit between the heating module 20 and the power supply module 10 is not zero, that is, there is current in any circuit, that is, IL1≠0, or IL2≠0, or IL3≠0, then it means that the electric auxiliary thermal protection relay K4, K5 or K6 is stuck. At this time, the first current detection module 42 can control the disconnection of the electric auxiliary thermal protection relays K7, K8 and K9 to prevent the heating module 20 from continuously heating the heated medium and causing accidents.

[0203] In this way, the present application detects the current between the power module 10 and the heating module 20 through the first current detection module 42 and then detects the on and off status of the relays in the first switch module 30 and the second switch module 50 to prevent accidents caused by the heating module 20 continuously heating the heated medium due to adhesion of the relay.

[0204] In addition, in addition to applying the above method to prevent the relays in the first switch module 30 and the second switch module 50 from sticking, the present application can also use a voltage detector directly connected to the two ends of each relay. When it is necessary to disconnect one or more relays, it can be determined whether the relay is stuck by checking whether there is a displayed value on the voltage detector, thereby preventing accidents caused by the heating module 20 continuing to heat the heated medium due to the adhesion of the relay.

[0205] Referring to FIG. 22 , the electric heating control method includes:

[0206] 06: After the first temperature detection module outputs the first electrical signal, when the first voltage detection module detects that there is a voltage across at least one relay in the first switch module, a fourth electrical signal is output to control the second switch module to control the circuit between the heating module and the power supply module to be disconnected; and

[0207] 08: After the first temperature detection module outputs the second electrical signal, when the voltage detection module detects that there is voltage at both ends of at least one relay in the second switch module, it outputs a fifth electrical signal to control the third switch module to control the circuit between the heating module and the power supply module to be disconnected.

[0208] Referring to FIG. 20 , steps 06 and 08 can also be implemented by the electric heating control device 200. That is, the electric heating control device 200 is configured to, after the temperature detection module outputs the first electrical signal, output a fourth electrical signal to control the second switch module to disconnect the circuit between the heating module and the power module when the voltage detection module detects that a voltage exists across the terminals of at least one relay in the first switch module; and, after the temperature detection module outputs the second electrical signal, output a fifth electrical signal to control the third switch module to disconnect the circuit between the heating module and the power module when the voltage detection module detects that a voltage exists across the terminals of at least one relay in the second switch module.

[0209] The specific structure, connection relationship and detection steps of the first voltage detection module 43 are as described above and will not be repeated here.

[0210] In this way, the electric heating control method of the present application can also detect whether the relays in the first switch module 30 and the second switch module 50 are sticking through the first voltage detection module 43, so that corresponding protective measures can be taken in time to prevent accidents caused by the heating module 20 continuing to heat the heated medium due to the adhesion of the relay.

[0211] Referring to FIG. 23 , the electric heating control method includes:

[0212] 091: Detecting the temperature of the heating wire of the electric heating tube in the heating module through the first temperature detection module, after the first temperature detection module outputs a first electrical signal, the first temperature detection module detects that the temperature of the heating wire rises by a preset value within a preset time, and outputs a second electrical signal to the second switch module to control the disconnection of the circuit between the heating module and the power supply module; and

[0213] 093: After the first temperature detection module outputs the second electrical signal, the first temperature detection module detects that the temperature of the heating wire rises to a preset value within a preset time, and outputs a sixth electrical signal to the third switch module to control the disconnection of the circuit between the heating module and the power supply module.

[0214] Referring to FIG20 , steps 091 and 093 can also be implemented by the electric heating control device 200. That is, the electric heating control device 200 is configured to detect the temperature of the heating wire of the electric heating tube in the heating module through the first temperature detection module, and after the first temperature detection module outputs a first electrical signal, if the first temperature detection module detects that the temperature of the heating wire has risen by a preset value within a preset time, then the device outputs a second electrical signal to the second switch module to control the disconnection of the circuit between the heating module and the power module; and after the first temperature detection module outputs a second electrical signal, if the first temperature detection module detects that the temperature of the heating wire has risen by a preset value within a preset time, then the device outputs a sixth electrical signal to the third switch module to control the disconnection of the circuit between the heating module and the power module.

[0215] The specific structure, connection relationship and detection steps of the first temperature detection module 41 are as described above and will not be repeated here.

[0216] As mentioned above, the preset time can be, for example, 2s, 3s, 4s, 5s, 5.5s, 5.6s, 5.8s, 6s, 7s, or 7.5s, without limitation. The preset value can be, for example, 1°C, 1.5°C, 1.8°C, 2°C, 2.4°C, 2.8°C, 3°C, 4°C, 5°C, or 6°C, without limitation.

[0217] In this way, the electric heating control method of the present application can also detect whether the relays in the first switch module 30 and the second switch module 50 are sticking through the first temperature detection module 41, so that corresponding protective measures can be taken in time to prevent accidents caused by the heating module 20 continuing to heat the heated medium due to the adhesion of the relay.

[0218] In certain embodiments of the present application, the electric heating control method includes: when the first current detection module outputs a third electrical signal, the control prompt module issues a temperature warning prompt for the heated medium; when the first voltage detection module outputs a fifth electrical signal, the control prompt module issues a temperature warning prompt for the heated medium; and when the first temperature detection module outputs a sixth electrical signal, the control prompt module issues a temperature warning prompt for the heated medium.

[0219] The electric heating control device 200 is used to control the prompt module to issue a temperature warning prompt for the heated medium when the first current detection module outputs a third electrical signal; to control the prompt module to issue a temperature warning prompt for the heated medium when the first voltage detection module outputs a fifth electrical signal; and to control the prompt module to issue a temperature warning prompt for the heated medium when the first temperature detection module outputs a sixth electrical signal.

[0220] The temperature warning prompt can be given by voice prompt, by lighting a red light, or in other ways, without limitation.

[0221] In this way, the electric heating control method of the present application can issue a temperature warning prompt of the heated medium through the prompt module 70, so that the user can take corresponding power-off protection measures after receiving the prompt to prevent the heating module 20 from continuously heating the heated medium and causing accidents.

[0222] The present application also provides a heat pump heating unit. The heat pump heating unit includes the electric heating control device 200 in the above embodiment. The specific electric heating control device 200 is as described above and will not be repeated here.

[0223] In this way, the electric heating control device 200 in the heat pump heating unit of the present application can continue to detect the temperature of the heated medium after the first temperature detection module 41 outputs the first electrical signal. When the temperature reaches the second set value, it outputs a second disconnection signal to the second switch module 50 to control the disconnection of the circuit between the heating module and the power supply module, which can effectively avoid the relay in the first switch module 30 from sticking, causing the heating module to continue heating and causing accidents.

[0224] The present application also provides a heating and ventilation equipment. The heating and ventilation equipment includes the heat pump heating unit described in the above embodiment. The heating and ventilation equipment can be, for example, an air conditioner, a water heater, or other equipment.

[0225] In this way, the electric heating control device 200 in the HVAC equipment of the present application can continue to detect the temperature of the heated medium after the first temperature detection module 41 outputs the first electrical signal. When the temperature reaches the second set value, it outputs a second disconnection signal to the second switch module 50 to control the disconnection of the circuit between the heating module and the power supply module, which can effectively avoid the relay in the first switch module 30 from sticking, causing the heating module to continue heating and causing accidents.

[0226] 20 , the present application further provides an electric heating protection device 200 . The electric heating protection device includes the electric heating protection circuit 100 described in any one of the above embodiments. The specific structure of the electric heating protection circuit 100 is as described above and will not be repeated here.

[0227] In this way, when the electric heating protection circuit 100 of the electric heating protection device 200 of the present application detects that the current of the circuit between the power module 10 and the first switch module 30 does not reach the target current value within the first preset time, it is determined that the electric heating process of the heating module 20 has failed. The second current detection module 44 outputs the first detection result to the software control module 45 to control the disconnection of the first switch module 30, thereby playing a role in electric heating protection.

[0228] The present application also provides a heat pump heating unit. The electric heating control device 200 described in the above embodiment of the heat pump heating unit. The specific structures of the electric heating control device 200 and the electric heating protection circuit 100 are as described above and will not be repeated here.

[0229] In this way, the control module 40 of the electric heating protection circuit 100 of the electric heating protection device 200 and the electric heating control circuit 100 of the present application can determine whether a fault has occurred in the electric heating process of the heating module 20 based on the current or voltage detection results between the power module 10 and the first switch module 30, as well as the temperature of the heated medium within the heating module 20 and the temperature of the heating wire of the electric heating tube. If a fault has occurred in the electric heating process of the heating module 20, the control module 40 can promptly control the disconnection of the first switch module 30 based on the electrical signal, thereby providing electric heating protection.

[0230] The present application also provides a heating and ventilation equipment. The heating and ventilation equipment includes the heat pump heating unit described in the above embodiment. The heating and ventilation equipment can be, for example, an air conditioner, a water heater, or other equipment.

[0231] In this way, the electric heating protection circuit 100 of the electric heating protection device 200 in the heat pump heating unit of the HVAC equipment of the present application and the control module 40 of the electric heating control circuit 100 of the present application can send an electrical signal based on the current or voltage detection result between the power module 10 and the first switch module 30, and send an electrical signal based on the temperature of the heated medium in the heating module 20 and the temperature of the heating wire of the electric heating tube, to determine whether the electric heating process of the heating module 20 has failed. When it is determined that the electric heating process of the heating module 20 has failed, the control module 40 can promptly control the disconnection of the first switch module 30 based on the electrical signal, thereby playing a role in electric heating protection.

[0232] The above embodiments merely illustrate several implementation methods of the present application. While the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the present invention. It should be noted that a person skilled in the art could make various modifications and improvements without departing from the spirit of the present invention, all of which fall within the scope of protection of the present invention. Therefore, the scope of protection of the present invention shall be determined by the appended claims.

Claims

1. An electric heating control circuit, characterized in that, The electric heating control circuit includes: a power supply module for supplying power; a heating module connected to the power supply module to heat the medium to be heated; a first switch module disposed between the power supply module and the heating module, the first switch module being configured to control the on / off of the circuit between the heating module and the power supply module according to an electrical signal; a control module electrically connected to the first switch module, the control module being configured to issue the electrical signal according to the current or voltage detection result between the power supply module and the first switch module, or issue the electrical signal according to the temperature of the medium to be heated and the temperature of the heating wire of the electric heating tube in the heating module.

2. The electric heating control circuit according to claim 1, wherein The electric heating control circuit further includes: a second switch module disposed between the power supply module and the first switch module, or disposed between the heating module and the first switch module, the second switch module being configured to control the on / off of the circuit between the heating module and the power supply module; The control module includes a first temperature detection module electrically connected to the first switch module and the second switch module respectively. The first temperature detection module is configured to detect the temperature of the medium to be heated, and when the temperature reaches a first set value, output a first electrical signal to the first switch module to control the disconnection of the circuit between the heating module and the power supply module; after the first temperature detection module outputs the first electrical signal, continue to detect the temperature of the medium to be heated, and when the temperature reaches a second set value, output a second electrical signal to the second switch module to control the disconnection of the circuit between the heating module and the power supply module, where the second set value is greater than the first set value.

3. The electric heating control circuit according to claim 2, wherein The first temperature detection module includes: a first detection unit electrically connected to the first switch module, the first detection unit being configured to output the first electrical signal to the first switch module to control the disconnection of the circuit between the heating module and the power supply module when the temperature of the medium to be heated reaches the first set value; and a second detection unit electrically connected to the second switch module, the second detection unit being configured to output the second electrical signal to the second switch module to control the disconnection of the circuit between the heating module and the power supply module when the temperature of the medium to be heated reaches the second set value after the first switch module outputs the first electrical signal.

4. The electric heating control circuit according to claim 3, characterized in that, The electric heating control circuit includes a plurality of the second switch modules connected in series in sequence, and the second detection unit outputs different second electrical signals to control different second switch modules according to different second set values.

5. The electric heating control circuit according to claim 3, wherein, The electric heating control circuit includes a plurality of the second switch modules connected in series in sequence and a plurality of the second detection units connected to the second switch modules. The plurality of second detection units are respectively connected to the plurality of second switch modules in one-to-one correspondence; Multiple said second detection units respectively output different said second electrical signals, and the corresponding second set values are different when multiple said second detection units output different said second electrical signals.

6. The electric heating control circuit according to claim 2 or 3, characterized in that, The electric heating control circuit further includes: A third switch module, which is arranged between the power supply module and the second switch module, and the third switch module is used to control the on-off of the circuit between the heating module and the power supply module; and The control module further includes a first current detection module. One end of the first current detection module is connected to the circuit between the heating module and the power supply module, and the other end of the first current detection module is electrically connected to the third switch module. The first current detection module is used to output a third electrical signal to control the third switch module to disconnect the circuit between the heating module and the power supply module when there is current in the circuit between the heating module and the power supply module after the second switch module outputs the second electrical signal.

7. The electric heating control circuit according to claim 6, wherein The first switch module, the second switch module and the third switch module include one or more relays.

8. The electric heating control circuit according to claim 7, wherein, The control module further includes a first voltage detection module. The first voltage detection module includes at least one voltage detector. One voltage detector is connected to both ends of one relay. The voltage detectors in the first switch module and the second switch module are both electrically connected to the third switch module; the first voltage detection module is used for: After the first temperature detection module outputs the first electrical signal, when at least one voltage detector detects voltage across at least one of the relays in the first switch module, output a fourth electrical signal to control the second switch module to disconnect the circuit between the heating module and the power supply module; After the first temperature detection module outputs the second electrical signal, when at least one voltage detector detects voltage across at least one of the relays in the second switch module, output a fifth electrical signal to control the third switch module to disconnect the circuit between the heating module and the power supply module.

9. The electric heating control circuit according to claim 8, wherein The heating module includes an electric heating tube. The first temperature detection module is connected to the electric heating tube, and the first temperature detection module is also used to detect the temperature of the heating wire of the electric heating tube in real time; After the first temperature detection module outputs the first electrical signal, when the first temperature detection module detects that the temperature of the heating wire rises by a preset value within a preset time, output the second electrical signal to the second switch module to control the disconnection of the circuit between the heating module and the power supply module.

10. The electric heating control circuit according to claim 9, characterized in that, The first temperature detection module is connected to the third switch module, and the first temperature detection module is also used for: After the first temperature detection module outputs the second electrical signal, when it detects that the temperature of the heating wire or the heated medium rises by a preset value within a preset time, output a sixth electrical signal to the third switch module to control the disconnection of the circuit between the heating module and the power supply module.

11. The electric heating control circuit according to claim 10, characterized in that, The electric heating control circuit further includes a prompting module, which is electrically connected to the first current detection module, the first voltage detection module, and / or the first temperature detection module respectively. The prompting module is configured to: When the first current detection module outputs the third electrical signal, issue a temperature warning prompt for the medium to be heated; When the first voltage detection module outputs the fifth electrical signal, issue a temperature warning prompt for the medium to be heated; And When the first temperature detection module outputs the sixth electrical signal, issue a temperature warning prompt for the medium to be heated.

12. The electric heating control circuit according to claim 1, characterized in that, The control module includes: a second current detection module and a software control module. The second current detection module is connected to the circuit between the power supply module and the first switch module, and the second current detection module is configured to output a first detection result; the software control module is respectively connected to the second current detection module and the first switch module, and the software control module is configured to issue a seventh electrical signal according to the first detection result to control the disconnection of the first switch module.

13. The electric heating control circuit according to claim 12, characterized in that, The second current detection module includes a current transformer, a shaping and filtering unit, and a current calculation unit. The shaping and filtering unit is connected between the current transformer and the current calculation unit, and the shaping and filtering unit includes a first resistor, a shaping diode, a second resistor, a filtering capacitor, and a third resistor; The first end of the first resistor is respectively connected to the current transformer and the shaping diode, and the second end of the first resistor is grounded; The first end of the second resistor is connected to the shaping diode, and the second end of the second resistor is connected to the current calculation unit; The first end of the filtering capacitor is respectively connected to the second resistor and the current calculation unit, and the second end of the filtering capacitor is grounded; The first end of the third resistor is respectively connected to the second resistor and the current calculation unit, and the second end of the third resistor is grounded.

14. The electric heating control circuit according to claim 13, characterized in that, The electric heating control circuit includes: A second switch module, which is arranged between the power supply module and the first switch module, and the second switch module is also configured to control the on / off of the circuit between the heating module and the power supply module according to an electrical signal; The software control module is connected to the second switch module, and the software control module is configured to output an eighth electrical signal according to the first detection result to control the disconnection of the second switch module.

15. The electric heating control circuit according to claim 14, characterized in that, The first switch module and the second switch module include one or more relays.

16. The electric heating control circuit according to claim 15, characterized in that The second current detection module is configured to output a second detection result; The software control module is further configured to output a ninth electrical signal according to the second detection result to control the disconnection of the second switch module.

17. The electric heating control circuit according to claim 14, characterized in that, The control module includes a second temperature detection module, which is electrically connected to the software control module. The second temperature detection module is used to detect the temperature of the heated medium, so as to send a first control signal to the software control module to output a tenth electrical signal to control the disconnection of the first switch module; or send a second control signal to the software control module to output an eleventh electrical signal to control the disconnection of the second switch module.

18. The electric heating control circuit according to claim 17, wherein The heating module includes an electric heating tube. The second temperature detection module is connected to the electric heating tube. After the software control module controls the disconnection of the first switch module, the second temperature detection module is used to detect the temperature of the heating wire of the electric heating tube, so as to output the second control signal to the software control module to output a twelfth electrical signal to control the disconnection of the second switch module.

19. The electric heating control circuit according to claim 18, wherein, The control module further includes a second voltage detection module. The second voltage detection module includes at least one voltage detector. One voltage detector is connected across the two ends of a relay. The voltage detectors in the first switch module and the second switch module are both electrically connected to the software control module; the second voltage detection module is used to output a first electrical signal to the software control module to output a thirteenth electrical signal to control the disconnection of the second switch module.

20. The electric heating control circuit according to claim 19, wherein The electric heating control circuit further includes a prompt module, which is electrically connected to the software control module. The prompt module is used to give a fault prompt and give a temperature warning prompt corresponding to the heated medium.

21. An electric heating control method, based on the electric heating control circuit according to any one of claims 1 to 20, characterized in that, The electric heating control method includes: Detecting the temperature of the heated medium through the first temperature detection module; When the temperature reaches the first set value, controlling the first temperature detection module to output the first electrical signal to the first switch module to control the disconnection of the circuit between the heating module and the power supply module; After the first temperature detection module outputs the first electrical signal, detecting the temperature of the heated medium through the first temperature detection module; and When the temperature reaches the second set value, controlling the first temperature detection module to output the second electrical signal to the second switch module to control the disconnection of the circuit between the heating module and the power supply module, where the second set value is greater than the first set value.

22. The electric heating control method according to claim 21, characterized in that, The electric heating control method includes: After the second switch module outputs the second electrical signal, detecting whether there is current in the circuit between the heating module and the power supply module through the first current detection module; When the first current detection module detects that there is current in the circuit between the heating module and the power supply module, controlling the first current detection module to output a third electrical signal to control the third switch module to control the disconnection of the circuit between the heating module and the power supply module.

23. The electric heating control method according to claim 22, characterized in that, The electric heating control method includes: The temperature of the heating wire of the electric heating tube in the heating module is detected by the first temperature detection module. After the first temperature detection module outputs the first electrical signal, when the first voltage detection module detects that there is voltage across at least one of the relays in the first switch module, a fourth electrical signal is output to control the second switch module to disconnect the circuit between the heating module and the power supply module; and After the first temperature detection module outputs the second electrical signal, when the first voltage detection module detects that there is voltage across at least one of the relays in the second switch module, a fifth electrical signal is output to control the third switch module to disconnect the circuit between the heating module and the power supply module.

24. The electric heating control method according to claim 23, wherein The electric heating control method includes: After the first temperature detection module outputs the first electrical signal, when the first temperature detection module detects that the temperature of the heating wire rises by a preset value within a preset time, a second electrical signal is output to the second switch module to control the disconnection of the circuit between the heating module and the power supply module; and After the first temperature detection module outputs the second electrical signal, when the first temperature detection module detects that the temperature of the heating wire rises by a preset value within a preset time, a sixth electrical signal is output to the third switch module to control the disconnection of the circuit between the heating module and the power supply module.

25. The electric heating control method according to claim 24, characterized in that, The electric heating control method includes: While the first current detection module outputs the third electrical signal, control the prompting module to issue a temperature warning prompt for the medium to be heated; While the first voltage detection module outputs the fifth electrical signal, control the prompting module to issue a temperature warning prompt for the medium to be heated; and While the first temperature detection module outputs the sixth electrical signal, control the prompting module to issue a temperature warning prompt for the medium to be heated.

26. An electric heating control device, characterized in that, The electric heating control device includes the electric heating control circuit according to any one of claims 1 to 20 or is used to implement the electric heating control method according to any one of claims 21 to 25.

27. A heat pump heating unit, characterized in that, The heat pump heating unit includes the electric heating control device according to claim 26.

28. A heating, ventilation and air conditioning (HVAC) device, characterized in that, The heating and ventilation equipment includes the heat pump heating unit according to claim 27.

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