Electric heating protection circuit, electric heating protection device, heat pump heating unit and heating and ventilation equipment

Abstract

The utility model discloses an electric heating protection circuit, an electric heating protection device, a heat pump heating unit and heating and ventilation equipment. The electric heating protection circuit comprises a power supply module, a heating module, a first switch module, a current detection module and a software control module. The first switch module is used for controlling on-off of a circuit between the heating module and the power module. The current detection module is connected to a circuit between the power supply module and the first switch module, and the current detection module is used for outputting a first detection result. The software control module is connected with the current detection module and the first switch module, and the software control module is used for controlling the first switch module to be switched off according to the first detection result. When the current detection module judges that the electric heating process breaks down, the first detection result is output to the software control module to control the first switch module to be switched off, and the electric heating protection effect is achieved.

Description

Technical Field

[0001] This application relates to the field of electric heating technology, and in particular to an electric heating protection circuit, an electric heating protection device, a heat pump heating unit, and HVAC equipment. Background Technology

[0002] As national requirements for energy utilization and efficiency of electrical equipment become increasingly stringent, heat pump heating is becoming more and more common. However, when the heating capacity of heat pumps is insufficient under extremely low temperatures, electric heating elements are typically used as an auxiliary heat source. Because electric heating has high power and large current, it can be controlled using relays. However, this relay control method is prone to malfunctions in the electric heating process of the heating element, leading to unexpected problems. Utility Model Content

[0003] In view of this, the present invention aims to at least partially solve one of the problems in the related technology. Therefore, the purpose of this application is to provide an electric heating protection circuit, an electric heating protection device, a heat pump heating unit, and HVAC equipment.

[0004] This application provides an electric heating protection circuit. The electric heating protection circuit includes a power supply module, a heating module, a first switch module, a current detection module, and a software control module. The power supply module provides power; the heating module is connected to the power supply module to heat the medium being heated; the first switch module is disposed between the power supply module and the heating module, and is used to control the on / off state of the circuit between the heating module and the power supply module; the current detection module is connected to the circuit between the power supply module and the first switch module, and is used to output a first detection result; the software control module is connected to both the current detection module and the first switch module, and is used to control the disconnection of the first switch module based on the first detection result.

[0005] In some embodiments, the 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. The shaping and filtering unit includes a first resistor, a shaping diode, a second resistor, a filter capacitor, and a third resistor. The first terminal of the first resistor is connected to both the current transformer and the shaping diode, and the second terminal of the first resistor is grounded. The first terminal of the second resistor is connected to the shaping diode, and the second terminal of the second resistor is connected to the current calculation unit. The first terminal of the filter capacitor is connected to both the second resistor and the current calculation unit, and the second terminal of the filter capacitor is grounded. The first terminal of the third resistor is connected to both the second resistor and the current calculation unit, and the second terminal of the third resistor is grounded.

[0006] In some embodiments, the electric heating protection circuit includes a second switching module. The second switching module is disposed between the power supply module and the first switching module, and also controls the on / off state of the circuit between the heating module and the power supply module; the software control module is connected to the second switching module, and is used to control the disconnection of the second switching module based on the first detection result.

[0007] In some implementations, the first switch module and the second switch module include one or more relays.

[0008] In some implementations, the current detection module is used to output a second detection result; the software control module is also used to control the disconnection of the second switch module based on the second detection result.

[0009] In some embodiments, the electric heating protection circuit includes a temperature detection module electrically connected to the software control module. The 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 control the disconnection of the first switch module; or to send a second control signal to the software control module to control the disconnection of the second switch module.

[0010] In some embodiments, the heating module includes an electric heating element, and the temperature detection module is connected to the electric heating element. After the software control module controls the first switch module to be disconnected, the temperature detection module is used to detect the temperature of the heating wire of the electric heating element, so as to output the second control signal to the software control module to control the disconnection of the second switch module.

[0011] In some embodiments, the electric heating protection circuit further includes a voltage detection module, which includes at least one voltage detector connected to both ends of a relay. The voltage detectors in both the first and second switching modules are electrically connected to the software control module. The voltage detection module is used to output a first electrical signal to the software control module to control the disconnection of the second switching module.

[0012] In some embodiments, the electric heating protection circuit further includes a prompting module, which is electrically connected to the software control module. The prompting module is used to issue fault prompts and temperature warnings corresponding to the heated medium.

[0013] This application also provides an electric heating protection device. The electric heating protection device includes the electric heating protection circuit described in any of the above embodiments.

[0014] This application also provides a heat pump heating unit. The heat pump heating unit includes the electric heating control device described in the above embodiments.

[0015] This application also provides a heating, ventilation, and air conditioning (HVAC) device. The HVAC device includes the heat pump heating unit described in the above embodiments.

[0016] Thus, when the current detection module detects that the current in the circuit between the power supply module and the first switch module has not reached the target current value within a first preset time, this application determines that the electric heating process of the heating module has malfunctioned. The current detection module outputs the first detection result to the software control module to control the disconnection of the first switch module, thereby playing a role in electric heating protection.

[0017] Additional aspects and advantages of this application will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of this application. Attached Figure Description

[0018] The above and / or additional aspects and advantages of this application will become apparent and readily understood from the following description of the embodiments taken in conjunction with the accompanying drawings, wherein:

[0019] Figure 1 This is one of the structural schematic diagrams of the electric heating protection circuit in certain embodiments of this application;

[0020] Figure 2 This is a second schematic diagram of the structure of the electric heating protection circuit in some embodiments of this application;

[0021] Figure 3 This is the third schematic diagram of the structure of the electric heating protection circuit in some embodiments of this application;

[0022] Figure 4 This is the fourth schematic diagram of the structure of the electric heating protection circuit in some embodiments of this application;

[0023] Figure 5 This is the fifth schematic diagram of the structure of the electric heating protection circuit in some embodiments of this application;

[0024] Figure 6 This is the sixth schematic diagram of the structure of the electric heating protection circuit in some embodiments of this application;

[0025] Figure 7 This is a schematic diagram of the structure of an electric heating protection device according to certain embodiments of this application. Detailed Implementation

[0026] The embodiments of this application are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain this application, and should not be construed as limiting this application.

[0027] 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 construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Therefore, features defined as "first" or "second" may explicitly or implicitly include one or more of the stated features. In the description of this application, "multiple" means two or more, unless otherwise explicitly specified.

[0028] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection, an electrical connection, or a connection that allows communication between them; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication between two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0029] The following disclosure provides many different implementations or examples for carrying out different structures of this application. To simplify the disclosure, specific examples of components and arrangements are described below. Of course, these are merely examples and are not intended to limit the scope of this application. Furthermore, reference numerals and / or reference letters may be repeated in different examples; such repetition is for simplification and clarity and does not in itself indicate a relationship between the various implementations and / or arrangements discussed.

[0030] The embodiments of this application are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain this application, and should not be construed as limiting this application.

[0031] Please see Figure 1 This application provides an electric heating protection circuit 100. The electric heating protection circuit 100 includes a power supply module 10, a heating module 20, a first switch module 30, a current detection module 40, and a software control module 50.

[0032] The power module 10 is used to supply power. The power module 10 of this application can be a single-phase power supply or a three-phase power supply; no limitation is made here. The heating module 20 is connected to the power module 10 to heat the medium being heated.

[0033] The first switch module 30 is disposed between the power supply module 10 and the heating module 20. The first switch module 30 is used to control the on / off state of the circuit between the heating module 20 and the power supply module 10.

[0034] The current detection module 40 is connected to the circuit between the power supply module 10 and the first switch module 30. The current detection module 40 is used to output a first detection result. Specifically, after the first switch module 30 is closed, the current detection module 40 outputs the first detection result when it detects that the current in the circuit between the power supply module 10 and the first switch module 30 has not reached the target current value within a first preset time.

[0035] The first preset time can be, for example, 1S, 1.1S, 1.2S, 1.3S, 1.4S, 2S, 3S, 3.5S, 4S, 4.1S or other values, and there are no restrictions here.

[0036] The target current value can be 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, without any restrictions.

[0037] The software control module 50 is connected to both the current detection module 40 and the first switch module 30. The software control module 50 controls the first switch module 30 to disconnect based on the first detection result. That is, the first detection result can be transmitted to the software control module 50 in the form of an electrical signal. The software control module 50 is also used to control the first switch module 30 to close when electric heating begins.

[0038] Understandably, when the electric heating process of the heating module 20 begins, the software control module 50 will automatically issue a closing command to control the first switch module 30 to close, so that the heating module 20 and the power supply module 10 are powered on to start electric heating.

[0039] After the first switch module 30 is closed, when the current detection module 40 detects that the current in the circuit between the power supply module 10 and the first switch module 30 reaches the target current value within a 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.

[0040] Conversely, after the first switch module 30 is closed, if the current detection module 40 detects that the current in the circuit between the power supply module 10 and the first switch module 30 has not reached the target current value within a first preset time and outputs the first detection result, it can be determined that the electric heating process of the heating module 20 has malfunctioned. If the first switch module 30 continues to be closed to provide power to the heating module 20 through the power supply module 10, allowing the heating module 20 to perform the electric heating process, the malfunction may lead to an accidental electric heating situation or damage to the heating module 20. Therefore, this application controls the current detection module 40 to output the first detection result to the software control module 50, and the software control module 50 controls the first switch module 30 to be disconnected according to the first detection result, which can avoid accidents caused by electric heating malfunctions.

[0041] Thus, when the current detection module 40 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, it determines that the electric heating process of the heating module 20 has malfunctioned. The current detection module 40 outputs the first detection result to the software control module 50 to control the disconnection of the first switch module 30, thereby playing a role in electric heating protection.

[0042] Please see Figure 2 The electric heating protection circuit 100 also includes a second switch module 60. The second switch module 60 is disposed between the power supply module 10 and the first switch module 30, and is also used to control the circuit connection between the heating module 20 and the power supply module 10. The software control module 50 is connected to the second switch module 60, and is also used to control the disconnection of the second switch module 60 based on the first detection result.

[0043] The first switch module 30 and the second switch module 60 include one or more relays. For example... Figure 3 As shown, when the power supply module 10 is a three-phase power supply, both the first switch module 30 and the second switch module 60 include three relays. The first switch module 30 includes relays K1, K2 and K3, and the second switch module 60 includes relays K4, K5 and K6.

[0044] Understandably, the first switch module 30 can be the 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 the heated medium, such as 60°C. When the set temperature is reached, the software control module 50 will issue a disconnect command to control the disconnection of the relay, so as to stop the electric heating process when the set temperature is reached.

[0045] The second switch module 60 can be a protective relay group in the electric heating protection circuit 100. That is, when the software control module 50 controls the first switch module 30 to be disconnected according to the first detection result, it also controls the second switch module 60 to be disconnected. This can prevent accidents from happening in the electric heating process due to the first switch module 30 sticking together when it needs to be disconnected. In other words, the second switch module 60 can play a further protective role.

[0046] In one embodiment, when the current detection module 40 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 the first detection result, the software control module 50 can simultaneously issue a control command to simultaneously control the disconnection of the first switch module 30 and the second switch module 60, so as to ensure that the path between the heating module 20 and the power module 10 is disconnected in time, and to avoid a series of problems caused by the fault.

[0047] Please see Figure 3 In some embodiments of this application, the current detection module 40 is further configured to output a second detection result. Specifically, after the first switch module 30 is disconnected, the current detection module 40 detects that the current in the circuit between the power supply module 10 and the first switch module 30 has not decreased to a first preset threshold within a first predetermined time or has not decreased to zero within a second predetermined time, and outputs a second detection result, wherein the first predetermined time is less than the second predetermined time. The software control module 50 is configured to control the disconnection of the second switch module 60 based on the second detection result.

[0048] The first predetermined time is a relatively short time, such as 1 second, 2 seconds, 3 seconds, 4 seconds, 5 seconds, 6 seconds, 7 seconds, 8 seconds, 9 seconds or 10 seconds, and there is no restriction here.

[0049] The specific current value of the first preset threshold can be, for example, 10% of the rated current of the heating module 20, 11% of the rated current of the heating module 20, or other values, and is not limited here.

[0050] The first scheduled time is a relatively long time, such as 20 seconds, 25 seconds, 28 seconds, 30 seconds, 32 seconds, 35 seconds, 39 seconds, 40 seconds, 50 seconds or 60 seconds, and there is no restriction here.

[0051] Understandably, in some embodiments where the software control module 50 does not control the disconnection of the second switch module 60 based on the first detection result after the first switch module 30 is disconnected, the electric heating protection circuit 100 of this application can also determine whether the first switch module 30 is stuck by detecting whether the current in the circuit between the power supply module 10 and the first switch module 30 decreases to a first preset threshold within a first predetermined time or decreases to zero within a second predetermined time through the current detection module 40. Thus, when there is current in the circuit between the power supply module 10 and the first switch module 30, it is determined that the first switch module 30 is stuck. At this time, the current detection module 40 can output a second detection result to the software control module 50 to disconnect the second switch module 60 based on the second detection result, which can ensure that the circuit between the heating module 20 and the power supply module 10 is disconnected, avoiding unexpected situations in the electric heating process due to the first switch module 30 sticking.

[0052] Specifically, please combine Figure 3 When the power supply module 10 is a three-phase power supply, it may include L1 phase, L2 phase, and L3 phase power branches, which are electrically connected to the heating module 20 respectively. Current flows between the power supply module 10 and the first switch module 30, which can refer to... Figure 2 There is current in any one or more circuits connected to phases L1, L2 and L3.

[0053] The current detection module 40 may specifically include Figure 3 The system includes current transformers 41 (CT1) and 41 (CT2), a shaping and filtering unit 42 connected to the current transformers, and a current calculation unit 43 connected to the shaping and filtering unit 42. The shaping and filtering unit 42 includes a first resistor (…). Figure 3 R1 or R4 in the middle), shaping diode ( Figure 3 D1 and D2 in the middle), the second resistor ( Figure 3 R2 or R5 in the middle), filter capacitor ( Figure 3 E1 and E2) and the third resistor ( Figure 3 (R3 or R6 in the diagram). The first terminal of the first resistor is connected to the current transformer 42 and the shaping diode, respectively, and the second terminal of the first resistor is grounded. The first terminal of the second resistor is connected to the shaping diode, and the second terminal of the second resistor is connected to the current calculation unit 43. The first terminal of the filter capacitor is connected to the second resistor and the current calculation unit 43, respectively, and the second terminal of the filter capacitor is grounded. The first terminal of the third resistor is connected to the second resistor and the current calculation unit, respectively, and the second terminal of the third resistor is grounded.

[0054] In detail, the method for calculating the current values ​​of phases L1 and L2 in two branches of a three-phase power supply in this application is as follows:

[0055] Assuming the turns 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 phase current of L1 is I1, and the phase current of L2 is I2:

[0056]

[0057]

[0058] Assume 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 across the diode (D1 or D2) is VF:

[0059]

[0060]

[0061] Summarized as follows:

[0062]

[0063]

[0064] The equations for I1 and I2 above can be used by the current calculation unit 42 to calculate that I1 and I2 are both 0. After the first switch module 30 has been disconnected, if either I1 or I2 cannot be reduced 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 neither I1 nor I2 can be reduced to 10% of the rated current of the heating module 20, or if either I1 or I2 cannot be reduced to 0 or neither I1 nor I2 can be reduced 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 has become stuck. Therefore, at this time, the second detection result can be output by the current detection module 40 to the software control module 50 to control the disconnection of the second switch module 60, ensuring that the circuit between the heating module 20 and the power supply module 10 is disconnected, thereby avoiding an accident in the electric heating process due to the sticking of the first switch module 30.

[0065] It should be noted that the determination of the presence of current in any one or more circuits connected to phases L1, L2, and L3 can also be based on the following method: if, for a period of time after the first switch module 30 is disconnected, a continuous current is present in any one of the circuits connected to the power supply of phases L1, L2, and L3, then the first switch module 30 has become stuck. For example, if, within 3 seconds after the first switch module 30 is disconnected, the current detection module 40 detects a continuous current in any one or more circuits connected to the power supply of phases L1, L2, and L3 for 3 seconds, that is, the current in the three circuits is not zero within 3 seconds, and if the current value in the three circuits remains at 2A or other values ​​within 3 seconds, then the first switch module 30 has become stuck.

[0066] Please see Figure 4 and Figure 5 In one embodiment of this application, the electric heating protection circuit 100 includes a temperature detection module 70. The temperature detection module 70 is electrically connected to the software control module 50. The temperature detection module 70 is used to detect the temperature of the heated medium, and to send a first control signal to the software control module to control the disconnection of the first switch module; or to send a second control signal to the software control module to control the disconnection of the second switch module.

[0067] Specifically, when the temperature detection module 70 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 50 to control the disconnection of the first switch module 30. After detecting that the temperature of the heated medium has reached the first set value, the temperature detection module 70 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 50 to control the disconnection of the second switch module 60, wherein the second set value is greater than the first set value.

[0068] The first control signal and the second control signal can be either voltage signals or current signals, and there are no restrictions on this.

[0069] The values ​​of the first and second setpoints are related to the type of heated medium. Different heated media correspond to different first and second setpoints. When the heated medium is water, the first setpoint can be, for example, 58℃, 60℃, 62℃, 62.5℃, 65℃, 66℃, 67℃, 68℃, 69℃, or 70℃, without limitation. The second setpoint can be, for example, 68℃, 70℃, 72℃, 72.5℃, 75℃, 76℃, 77℃, 78℃, 79℃, or 80℃, without limitation. In a specific embodiment, when the heated medium is water, the first setpoint can be 60℃ and the second setpoint can be 70℃.

[0070] Understandably, the first set value can be the target temperature that the heated medium needs to reach under normal heating conditions, while the second set value is the higher temperature detected after the heated medium has reached the target temperature, due to the adhesion of the first switch module 30 causing the heated medium to continue heating. Therefore, when the temperature detection module 70 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 50, thereby controlling the second switch module 60 to disconnect, preventing a safety accident from occurring during the electric heating process of the heating module 20 due to the adhesion of the first switch module 30.

[0071] Thus, this application can send a first control signal to the software control module 50 when the temperature of the heated medium reaches the first set value, via the temperature detection module 70, to control the first switch module 30 to precisely control the target heating temperature of the heated medium. After the first switch module 30 is disconnected, when the temperature of the heated medium continues to increase to the second set value, the temperature detection module 70 sends a second control signal to the software control module 50 to avoid safety accidents during the electric heating process of the heating module 20 due to adhesion of the first switch module 30.

[0072] In another embodiment of this application, the heating module 20 includes an electric heating tube, and the temperature detection module 70 is connected to the electric heating tube. After the software control module 50 controls the first switch module 30 to be disconnected, the temperature detection module 70 is used to detect the temperature of the heating wire of the electric heating tube, so as to output a second control signal to the software control module 50 to control the second switch module 60 to be disconnected.

[0073] Specifically, after the software control module 50 controls the first switch module 30 to be disconnected, the temperature detection module 70 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 50 to control the second switch module 60 to be disconnected.

[0074] The second preset time can be, for example, 2S, 3S, 3.5S, 4S, 4.5S, 5S, 5.1S, 5.5S, 6S or 6.5S, and there are no restrictions here.

[0075] The preset values ​​can be, for example, 1℃, 2℃, 2.5℃, 3℃, 3.5℃, 4℃, 4.5℃, 5℃, 5.1℃ or 6℃, and there are no restrictions here.

[0076] Understandably, if the temperature detection module 70 still detects that the heating wire temperature continues to rise by a preset value within a second preset time after the software control module 50 controls the first switch module 30 to disconnect, it indicates that the first switch module 30 has become stuck, causing the heating module 20 to continue heating the heated medium. Therefore, the temperature detection module 70 can also send a second control signal to the software control module 50 at this time, thereby controlling the disconnection of the second switch module 60. This ensures that the connection between the heating module 20 and the power supply module 10 is broken in the event of the first switch module 30 becoming stuck, preventing safety accidents caused by continuous electric heating.

[0077] Thus, the electric heating protection circuit 100 of this application can also detect the temperature of the heating wire of the electric heating tube through the temperature detection module 70, and then determine whether the first switch module 30 is stuck. In the event that the first switch module 30 is stuck, the second switch module 60 is disconnected to avoid safety accidents caused by continuous electric heating.

[0078] In another embodiment of this application, the electric heating protection circuit 100 further includes a voltage detection module. The 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 60 are both electrically connected to the software control module 50. The voltage detection module is used to output a first electrical signal to the software control module 50 to control the disconnection of the second switch module 60.

[0079] Specifically, after the software control module 50 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 decreased to the second preset threshold within a third predetermined time or has not decreased to zero within a fourth predetermined time, and outputs a first electrical signal to the software control module 50 to control the disconnection of the second switch module 60, wherein the third predetermined time is less than the fourth predetermined time.

[0080] 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, and there is no restriction here.

[0081] The specific current value of the second preset threshold can be, for example, 10% of the rated voltage of the heating module 20, 12% of the rated voltage of the heating module 20, or other values, and is not limited here.

[0082] The fourth scheduled time is a longer duration, such as 21 seconds, 23 seconds, 27 seconds, 31 seconds, 33 seconds, 35 seconds, 38 seconds, 40 seconds, 50 seconds, or 60 seconds, and there are no restrictions here.

[0083] Understandably, the electric heating protection circuit 100 of this 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 together.

[0084] Thus, when the voltage detector detects that the voltage across at least one relay of the first switching module 30 has not decreased to the second preset threshold within a third predetermined time or has not decreased to zero within a fourth predetermined time, the voltage protection circuit 100 of this application can output a first electrical signal to the software control module 50 to control the disconnection of the second switching module 60, so as to ensure that the path between the heating module 20 and the power module 10 is disconnected in time, and to avoid the occurrence of an accidental electric heating due to relay sticking.

[0085] Please see Figure 6 In some embodiments of this application, the electric heating protection circuit 100 may further include a prompting module 80. The prompting module 80 is electrically connected to the software control module 50. The prompting module 80 is used to issue fault prompts and temperature warnings corresponding to the heated medium.

[0086] Specifically, the prompt module 80 is used to issue a fault prompt when the software control module 50 controls the disconnection of the first switch module 30. The fault prompt can be given in the form of sound or text, or by flashing lights, or in other ways; there are no restrictions here. The fault prompt given in the form of sound or text could be something like, "Your electric heating equipment has experienced a heating malfunction; please have it repaired promptly!"

[0087] Additionally, while the software control module 50 receives the second control signal and / or the second detection result to control the disconnection of the second switch module 60, the prompting module 90 is also used to issue a temperature warning prompt corresponding to the heated medium. The temperature warning prompt can be given in the form of sound or text, or by flashing lights, or in other ways, without limitation. The fault prompt message given in the form of sound or text could be, "The temperature of your electrically heated medium is too high, please be careful!"

[0088] Thus, the electric heating protection circuit 100 of this application can prompt the user through the prompt module 80 whether a malfunction has occurred in 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 a timely manner, thereby improving the safety of the electric heating process.

[0089] Please see Figure 7This application also provides an electric heating protection device 200. The electric heating protection device includes the electric heating protection circuit 100 described in any of the above embodiments. The specific structure of the electric heating protection circuit 100 is as described above and will not be repeated here.

[0090] Thus, when the current detection module 40 detects that the current in the circuit between the power supply module 10 and the first switch module 30 has not reached the target current value within a first preset time, the electric heating protection circuit 100 of the electric heating protection device 200 of this application determines that the electric heating process of the heating module 20 has failed, and the current detection module 40 outputs the first detection result to the software control module 50 to control the disconnection of the first switch module 30, thereby playing the role of electric heating protection.

[0091] This application also provides a heat pump heating unit. The heat pump heating unit includes the electric heating control device 200 described in the above embodiments. 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.

[0092] Thus, in the heat pump heating unit of this application, when the current detection module 40 detects that the current in the circuit between the power supply module 10 and the first switch module 30 has not reached the target current value within a first preset time, the electric heating protection circuit 100 of the electric heating protection device 200 determines that the electric heating process of the heating module 20 has failed, and the current detection module 40 outputs the first detection result to the software control module 50 to control the disconnection of the first switch module 30, thereby playing the role of electric heating protection.

[0093] This application also provides a heating, ventilation, and air conditioning (HVAC) system. The HVAC system includes the heat pump heating unit described in the above embodiments. The HVAC system can be, for example, an air conditioner, a water heater, or other similar equipment.

[0094] Thus, in the heat pump heating unit of the HVAC equipment of this application, when the current detection module 40 detects that the current in the circuit between the power supply module 10 and the first switch module 30 has not reached the target current value within a first preset time, the electric heating protection circuit 100 determines that the electric heating process of the heating module 20 has failed, and the current detection module 40 outputs the first detection result to the software control module 50 to control the disconnection of the first switch module 30, thereby playing the role of electric heating protection.

[0095] The above embodiments merely illustrate several implementation methods of this application, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of this patent application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this patent application should be determined by the appended claims.

Claims

1. An electric heating protection circuit, characterized in that, The electric heating protection circuit includes: Power module, the power module is used for power supply; A heating module, which is connected to the power module to heat the medium being heated; A first switch module is disposed between the power supply module and the heating module, and the first switch module is used to control the circuit connection between the heating module and the power supply module; A current detection module is connected in the circuit between the power supply module and the first switch module, and the current detection module is used to output a first detection result; A software control module is connected to both the current detection module and the first switch module. The software control module is used to control the disconnection of the first switch module based on the first detection result. The electric heating protection circuit includes: The second switch module is disposed between the power module and the first switch module, and the second switch module is also used to control the circuit connection between the heating module and the power module. The software control module is connected to the second switch module, and the software control module is used to control the second switch module to disconnect according to the first detection result; the electric heating protection circuit includes a temperature detection module, which is electrically connected to the software control module, and the 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 control the disconnection of the first switch module; or send a second control signal to the software control module to control the disconnection of the second switch module.

2. The electric heating protection circuit according to claim 1, characterized in that, The 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. 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 connected to the current transformer 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; The first terminal of the filter capacitor is connected to the second resistor and the current calculation unit respectively, and the second terminal 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.

3. The electric heating protection circuit according to claim 1, characterized in that, The first switch module and the second switch module include one or more relays.

4. The electric heating protection circuit according to claim 1, characterized in that, The current detection module is used to output a second detection result; The software control module is also used to control the disconnection of the second switch module based on the second detection result.

5. The electric heating protection circuit according to claim 1, characterized in that, The heating module includes an electric heating element, and the temperature detection module is connected to the electric heating element. After the software control module controls the first switch module to be disconnected, the temperature detection module is used to detect the temperature of the heating wire of the electric heating element, so as to output the second control signal to the software control module to control the disconnection of the second switch module.

6. The electric heating protection circuit according to claim 1, characterized in that, The electric heating protection circuit further includes a voltage detection module, which includes at least one voltage detector. One of the voltage detectors is connected to both 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 voltage detection module is used to output a first electrical signal to the software control module to control the disconnection of the second switch module.

7. The electric heating protection circuit according to claim 5, characterized in that, The electric heating protection circuit also includes a prompting module, which is electrically connected to the software control module. The prompting module is used to issue fault prompts and temperature warnings corresponding to the heated medium.

8. An electric heating protection device, characterized in that, The electric heating protection device includes the electric heating protection circuit as described in any one of claims 1 to 7.

9. A heat pump heating unit, characterized in that, The heat pump heating unit includes the electric heating protection device as described in claim 8.

10. A heating, ventilation, and air conditioning (HVAC) device, characterized in that, The heating and ventilation equipment includes the heat pump heating unit as described in claim 9.

Images