Heating unit, film heater, film heating circuit, control method and device

Abstract

The invention discloses a heating unit, a film heater, a film heating circuit and a control method and device. The heating unit comprises a substrate, a first heating film and a second heating film, the first heating film and the second heating film are arranged on the substrate in parallel at an interval; the first heating film and the second heating film are used for being connected with a film heating circuit. According to the heating unit, the first heating film and the second heating film are arranged on the substrate in parallel, so that when any one of the first heating film and the second heating film stops working, the heating area of the substrate is not obviously changed, the substrate is still kept in a uniform heating state, and the heating films are prevented from falling off and being damaged due to non-uniform thermal stress.

Description

Technical Field

[0001] The present invention relates to the field of film heating technology, and in particular to a heating unit, a film heater, a film heating circuit, a control method and a device. Background Art

[0002] Film heating is a technology that uses thin film materials with resistive heating to achieve heating purposes. It mainly uses the heat generated by the current passing through the heating film to achieve heating. The heating unit made with film heating technology has a more uniform heating effect and faster response speed, and is widely welcomed by users.

[0003] In the existing heating units that utilize heating films to generate heat, at least two heating films are usually laid on the substrate to obtain a sufficiently large heat generation area and a higher heating efficiency. However, the existing heating films are usually laid on the substrate in different areas. When one of the heating films fails and loses power and cannot generate heat, a large temperature difference will appear between the area where the failed heating film is located and other areas, which will cause uneven thermal stress and lead to the heating film falling off and being damaged. Summary of the invention

[0004] The embodiments of the present invention provide a heating unit, a film heater, a film heating circuit, a control method and a device to solve the problem that when a heating film in the heating unit fails and loses power and cannot generate heat, uneven thermal stress may be caused, resulting in the heating film falling off and being damaged.

[0005] An embodiment of the present invention provides a heating unit, comprising a substrate, a first heating film and a second heating film; The first heating film and the second heating film are arranged on the substrate in parallel and at intervals; The first heating film and the second heating film are used to be connected to a film heating circuit.

[0006] Preferably, the first heating film is arranged in a serpentine shape, and the second heating film is arranged in a serpentine shape; The first heating films and the second heating films are arranged alternately.

[0007] An embodiment of the present invention further provides a film heater, comprising a housing and any one of the above described heating units; The heating unit is arranged in the shell, and a base plate of the heating unit is connected to an inner wall of the shell.

[0008] Preferably, the film heater further comprises two flow guide components, a heater inlet and a heater outlet; The two flow guide components are respectively arranged on both sides of the heating unit; Each of the flow guide components cooperates with the shell to form a steady flow cavity, and the heater outlet and the heater inlet are respectively arranged opposite to one of the steady flow cavities.

[0009] Preferably, the flow guide assembly comprises at least one flow guide plate; One end of each of the guide plates is connected to an inner wall of the shell; At least one of the guide plates and the heating unit are arranged alternately to form a serpentine guide channel between at least one of the guide plates and the heating unit; A guide plate farthest from the heating unit cooperates with the shell to form a steady flow cavity; A heater inlet or a heater outlet is provided on the inner wall of the shell corresponding to the flow stabilizing cavity.

[0010] An embodiment of the present invention further provides a film heating circuit, which is used to be connected to any of the above-mentioned heating units, and the film heating circuit includes a power module, a detection module and a controller; The power module is connected to the heating unit and is used to supply power to the heating unit; The detection module is connected to the heating unit and the power module and is used to collect detection signals; The controller is connected to the power module and the detection module, and controls the power module to work according to the detection signal output by the detection module.

[0011] Preferably, the detection module includes a current sampling circuit, a voltage sampling circuit and a temperature sampling circuit; The current sampling circuit is connected to the power module and is used to collect the current detection signal of the power module; The voltage sampling circuit is connected to the heating unit and is used to collect the voltage detection signal of the heating unit; The temperature sampling circuit is connected to the heating unit and is used to collect the temperature detection signal of the heating unit; The controller is connected to the current sampling circuit, the voltage sampling circuit and the temperature sampling circuit, and is used to control the operation of the power module according to the current detection signal, the voltage detection signal and the temperature detection signal.

[0012] Preferably, the power module includes a drive circuit and a power circuit; The power circuit is connected to the heating unit and is used to supply power to the heating unit; The driving circuit is connected to the power circuit and the controller, and is used to adjust the output power of the power circuit under the control of the controller.

[0013] Preferably, the power circuit includes a first control tube and a second control tube; The first end of the first control tube is used to be connected to the first end of the power supply, the second end of the first control tube is connected to the second end of the power supply through the first heating film, and the third end of the first control tube is connected to the driving circuit; The first end of the second control tube is used to connect to the first end of the power supply, the second end of the second control tube is connected to the second end of the power supply through the second heating film, and the third end of the second control tube is connected to the driving circuit.

[0014] Preferably, the power circuit further comprises a first capacitor and a second capacitor; Two ends of the first capacitor are respectively connected to a first end and a second end of the first control tube; Two ends of the second capacitor are connected to the first end and the second end of the second control tube respectively.

[0015] Preferably, the film heating circuit further comprises an auxiliary power supply module; The auxiliary power supply module is connected to the controller and the drive circuit, and is used to supply power to the controller and the drive circuit.

[0016] Preferably, the film heating circuit further comprises an isolation module; The controller is connected to the host computer through the isolation module and is used for communicating with the host computer.

[0017] An embodiment of the present invention further provides a film heating control method, which is applied to the film heating circuit as described in any one of the above, and includes the following steps executed by a controller: Get the detection signal; If the detection signal meets the fault assessment condition, a protection operation is performed; If the detection signal does not meet the fault assessment condition, the power module is controlled to operate.

[0018] Preferably, the fault assessment condition includes: the current current is greater than a preset current; or the current voltage is greater than a preset voltage; or the current temperature is greater than a preset temperature; The executing protection operation includes: controlling to shut down the power module and sending a fault signal to a host computer.

[0019] Preferably, the fault assessment condition includes: a plurality of temperature detection signals collected by the same heating film in a plurality of consecutive sampling periods are the same; The execution of the protection operation includes: shutting down control tubes corresponding to a plurality of heating films having the same temperature detection signals, and sending a fault signal to a host computer.

[0020] Preferably, the controlling the power module to operate includes: Get the ambient temperature signal sent by the host computer; Based on the ambient temperature signal, the power module is controlled to output a corresponding PWM signal.

[0021] Preferably, before acquiring the detection signal, the film heating control method further comprises: Perform self-inspection on the current function based on preset inspection rules; If the current function is in a normal state, a heating instruction sent by the host computer is obtained, and the power module is controlled to work according to the heating instruction; If the current function is in an abnormal state, a fault signal will be sent to the host computer.

[0022] An embodiment of the present invention further provides a film heating device, comprising the film heater as described in any one of the above items and the film heating circuit as described in any one of the above items, wherein the film heating circuit is used to execute the film heating control method as described in any one of the above items.

[0023] In the heating unit, film heater, film heating circuit, control method and device provided by the embodiments of the present invention, the heating unit is provided with a first heating film and a second heating film in parallel on the substrate, so that when either of the first heating film and the second heating film stops working, the heated area of ​​the substrate does not change significantly, so that the substrate still maintains a uniform heating state, and avoids the heating film from falling off and being damaged due to uneven thermal stress. The controller in the film heating circuit can monitor the current of the power module, the voltage at both ends of the heating unit, and the current temperature of the heating unit in real time, and control the operation of the power module according to the acquired current detection signal, voltage detection signal and temperature detection signal, so as to form feedback control on the heating unit and ensure the normal operation of the heating unit. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings required for use in the description of the embodiments of the present invention will be briefly introduced below. Obviously, the accompanying drawings in the following description are only some embodiments of the present invention. For ordinary technicians in this field, other accompanying drawings can be obtained based on these accompanying drawings without paying creative labor.

[0025] Figure 1 is a structural schematic diagram of a heating unit in one embodiment of the present invention; Figure 2 is a schematic structural diagram of a film heater in one embodiment of the present invention; Figure 3 is a block diagram of a membrane heating circuit in one embodiment of the present invention; Figure 4 is a circuit structure schematic diagram of a film heating circuit in one embodiment of the present invention; Figure 5 is a flow chart of a control method of a film heating circuit in one embodiment of the present invention; Figure 6 is another flow chart of a control method of a film heating circuit in one embodiment of the present invention; Figure 7 is another flow chart of a control method of a film heating circuit in one embodiment of the present invention.

[0026] In the figure: 1. heating unit; 11. substrate; 12. first heating film; 13. second heating film; 2. shell; 3. guide assembly; 31. flow stabilizing cavity; 32. guide plate; 4. heater inlet; 5. heater outlet; 6. power module; 61. drive circuit; 62. power circuit; 7. detection module; 71. current sampling circuit; 72. voltage sampling circuit; 73. temperature sampling circuit; 74. signal processing circuit; 8. controller; 9. auxiliary power module; 10. isolation module; 14. host computer. DETAILED DESCRIPTION

[0027] In order to make the technical problems, technical solutions and beneficial effects solved by the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0028] In the description of the present invention, it should be understood that the terms "longitudinal", "radial", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In the description of the present invention, unless otherwise specified, "plurality" means two or more.

[0029] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0030] An embodiment of the present invention provides a heating unit 1, comprising a substrate 11, a first heating film 12 and a second heating film 13; the first heating film 12 and the second heating film 13 are arranged in parallel and spaced apart on the substrate 1; the first heating film 12 and the second heating film 13 are used to be connected to a film heating circuit.

[0031] As an example, the heating unit 1 includes a substrate 11 and a first heating film 12 and a second heating film 13 arranged in parallel and spaced apart on the substrate 11. The spacing distance between the first heating film 12 and the second heating film 13 is within a set smaller distance value, and the smaller distance value is determined according to the size of the substrate. For example, the smaller distance value is 5% of the length or width of the substrate. The purpose is to arrange the first heating film 12 and the second heating film 13 at a close distance on the substrate 11, so that after one of the first heating film 12 and the second heating film 13 stops working, the heated area of ​​the substrate 11 will not change significantly. The first heating film 12 and the second heating film 13 are both connected to the film heating circuit to convert the electrical energy supplied by the film heating circuit into heat energy. When the first heating film 12 and the second heating film 13 work at the same time, the first heating film 12 and the second heating film 13 can transfer heat to the substrate 11 at the same time, and when any one of the first heating film 12 and the second heating film 13 does not work, since the first heating film 12 and the second heating film 13 are arranged in parallel and the distance between the first heating film 12 and the second heating film 13 is small, after one of the first heating film 12 and the second heating film 13 stops working, a nearby heating film still transfers heat to the substrate 11, and the heated area of ​​the substrate 11 does not change significantly. Therefore, uneven heating will not be caused by the cessation of one of the first heating film 12 and the second heating film 13, and the damage of the heating film due to uneven thermal stress can be avoided, thereby extending the life of the heating unit 1.

[0032] In one embodiment, the first heating films 12 are arranged in a serpentine shape, and the second heating films 13 are arranged in a serpentine shape; the first heating films 12 and the second heating films 13 are arranged alternately.

[0033] As an example, the first heating film 12 includes n first heating segments extending along the width direction of the substrate 11, and the n first heating segments are connected end to end, so that the first heating film 12 is arranged in a serpentine shape on the substrate 11 to increase the contact area between the first heating film 12 and the substrate 11, which helps to ensure its heating efficiency. Similarly, the second heating film 13 includes n second heating segments extending along the width direction of the substrate 11, and the n second heating segments are connected end to end, so that the second heating film 13 is arranged in a serpentine shape on the substrate 11 to increase the contact area between the second heating film 13 and the substrate 11, which helps to ensure its heating efficiency. The first heating film 12 and the second heating film 13 are arranged in parallel and spaced apart, so that at least two first heating segments and at least two second heating segments are alternately arranged on the substrate 11, forming a staggered arrangement structure of the first heating film 12 and the second heating film 13, which helps to ensure the heating efficiency of the entire substrate 11, and when any heating film fails, the heating effect of the substrate 11 can still be guaranteed. In this example, by arranging the first heating film 12 and the second heating film 13 in a serpentine shape, the first heating film 12 and the second heating film 13 can both form a uniform coverage on the substrate 11, so that the substrate 11 is heated evenly. The first heating film 12 and the second heating film 13 are parallel, spaced and staggered, so that after either of the first heating film 12 and the second heating film 13 stops working, the heated area of ​​the substrate 11 does not change significantly, and the substrate 11 still maintains a uniform heating state, thereby avoiding uneven thermal stress and causing the heating film to fall off and be damaged.

[0034] An embodiment of the present invention provides a film heater, comprising a housing 2 and a heating unit 1 in any one of the above embodiments; the heating unit 1 is disposed in the housing 2 , and a substrate 11 of the heating unit 1 is connected to an inner wall of the housing 2 .

[0035] As an example, the film heater includes a housing 2 and a heating unit 1 in any of the above examples. The heating unit 1 is arranged in the housing 2, and one side of the substrate 11 of the heating unit 1 is fixedly connected to an inner wall of the housing 2, and is used to heat the fluid for heat transfer filled in the housing 2. In this example, the first heating film 12 and the second heating film 13 in the heating unit 1 are arranged in parallel on the substrate 11. When any one of the first heating film 12 and the second heating film 13 stops working, the heated area of ​​the substrate 11 does not change significantly, and the substrate 11 still maintains a uniform heating state, which can avoid the heating film from falling off and being damaged due to uneven thermal stress.

[0036] In one embodiment, the film heater also includes two flow guide components 3, a heater inlet 4 and a heater outlet 5; the two flow guide components 3 are respectively arranged on both sides of the heating unit 1; each flow guide component 3 cooperates with the shell 2 to form a steady flow cavity 31, and the heater outlet 5 and the heater inlet 4 are respectively arranged opposite to a steady flow cavity 31.

[0037] As an example, the film heater includes a heater inlet 4 and a heater outlet 5. The fluid to be heated flows into the shell 2 of the film heater from the heater inlet 4. The heating unit 1 heats the fluid, and the heated fluid flows out from the heater outlet 5. The film heater also includes two flow guide components 3. The flow guide components 3 are used to guide the flow direction of the fluid and extend the flow path of the fluid so that the fluid can be fully heated in the shell 2. In this example, the heating unit 1 is arranged in the central area of ​​the shell 2, and the two flow guide components 3 are respectively arranged on both sides of the heating unit 1, and are respectively arranged opposite to the two side surfaces of the heating unit 1. A steady flow cavity 31 is formed between each flow guide component 3 and the shell 2, and the heater outlet 5 and the heater inlet 4 are respectively arranged opposite to a steady flow cavity 31. When the fluid to be heated flows in from the heater inlet 4, it first passes through a steady flow cavity 31 between the shell 2 and a flow guide component 3, and then continues to pass through the flow guide component 3 to the vicinity of the heating unit 1. The heating unit 1 heats the fluid, and the heated fluid passes through another steady flow cavity 31 between the shell 2 and another flow guide component 3, and finally flows out from the heater outlet 5 corresponding to the other steady flow cavity 31. In this example, the steady flow cavity 31 arranged opposite to the heater inlet 4 can play a buffering role for the fluid that has just entered the shell 2, and the steady flow cavity 31 connected to the heater outlet 5 can make the fluid that is about to flow out of the shell 2 fully mixed again in the steady flow cavity 31, so that the temperature of the fluid flowing in and out of the shell 2 is more uniform and constant, thereby making the heating temperature of the film heater more stable and controllable.

[0038] In one embodiment, the guide assembly 3 includes at least one guide plate 32; one end of each guide plate 32 is connected to an inner wall of the shell 2; at least one guide plate 32 and the heating unit 1 are alternately arranged to form a serpentine guide channel between at least one guide plate 32 and the heating unit 1; the guide plate 32 farthest from the heating unit 1 cooperates with the shell 2 to form a steady flow cavity 31, and a heater inlet 4 or a heater outlet 5 is provided on the inner wall of the shell 2 corresponding to the steady flow cavity 31.

[0039] As an example, the guide assembly 3 includes at least one guide plate 32. One end of each guide plate 32 is connected to an inner wall of the shell 2, and in each guide assembly 3, at least one guide plate 32 and the heating unit 1 are staggered. In this example, the heating unit 1 can be connected to the first inner wall of the shell 2, and a guide plate 32 adjacent to the heating unit 1 can be connected to the second inner wall of the shell 2. Any two adjacent guide plates 32 are staggered on the first inner wall and the second inner wall, wherein the first inner wall and the second inner wall are two inner walls arranged opposite to each other, so that a serpentine guide channel is formed between at least one guide plate 32 and the heating unit 1, so that the flow rate of the fluid in the guide channel is uniform. The guide plate 32 farthest from the heating unit 1 cooperates with the shell 2 to form a steady flow cavity 31. A heater inlet 4 or a heater outlet 5 is provided on the inner wall of the shell 2 corresponding to the steady flow cavity 31. Furthermore, in each guide assembly 3, a heater inlet 4 or a heater outlet 5 is provided on the inner wall of the shell 2 connected to a guide plate 32 farthest from the heating unit 1. By connecting the last guide plate 32 and the heater inlet 4 or the heater outlet 5 on the same inner wall, the fluid must completely pass through the steady flow cavity 31 after flowing out of the guide channel before being discharged through the heater outlet 5, or the fluid must completely pass through the steady flow cavity 31 for buffering when entering from the heater inlet 4 before entering the guide channel, thereby ensuring that the steady flow cavity 31 can play a buffering and constant temperature role.

[0040] An embodiment of the present invention also provides a film heating circuit, which is used to be connected to the heating unit 1 in any of the above-mentioned embodiments, and the film heating circuit includes a power module 6, a detection module 7 and a controller 8; the power module 6 is connected to the heating unit 1, and is used to supply power to the heating unit 1; the detection module 7 is connected to the heating unit 1 and the power module 6, and is used to collect detection signals; the controller 8 is connected to the power module 6 and the detection module 7, and controls the power module 6 to operate according to the detection signal output by the detection module 7.

[0041] As an example, the film heating circuit is connected to the heating unit 1, and the film heating circuit includes a power module 6, a detection module 7 and a controller 8. The power module 6 is connected to the heating unit 1 and is used to supply power to the heating unit 1 so that the heating unit 1 heats the fluid according to the amount of electric power supplied. The detection module 7 is connected to the heating unit 1, the power module 6 and the controller 8, and is used to collect detection signals, such as the current temperature of the heating unit 1, or the current flowing through the heating unit 1, and form a corresponding detection signal, and output it to the controller 8; the controller 8 is connected to the power module 6 and is used to control the power module 6 to work according to the detection signal output by the detection module 7. For example, according to the acquired detection signal, if it is known that the current temperature of the heating unit 1 exceeds the preset temperature range, the power module 6 is controlled to reduce the output power so that the temperature of the heating unit 1 is within the preset temperature range. In this example, the film heating circuit can form real-time detection and control of the heating temperature of the heating unit 1 to ensure that the heating unit 1 is heated normally.

[0042] In one embodiment, the detection module 7 includes a current sampling circuit 71, a voltage sampling circuit 72 and a temperature sampling circuit 73; the current sampling circuit 71 is connected to the power module 6, and is used to collect the current detection signal of the power module 6; the voltage sampling circuit 72 is connected to the heating unit 1, and is used to collect the voltage detection signal of the heating unit 1; the temperature sampling circuit 73 is connected to the heating unit 1, and is used to collect the temperature detection signal of the heating unit 1; the controller 8 is connected to the current sampling circuit 71, the voltage sampling circuit 72 and the temperature sampling circuit 73, and is used to control the operation of the power module 6 according to the current detection signal, the voltage detection signal and the temperature detection signal.

[0043] As an example, the detection module 7 includes a current sampling circuit 71, a voltage sampling circuit 72 and a temperature sampling circuit 73. The current sampling circuit 71 can be connected to the power module 6 through a signal processing circuit 74, and is used to collect the output current of the power module 6. The signal processing circuit 74 converts the collected output current into a current detection signal and sends it to the power module 6. Specifically, the current sampling circuit 71 may include a first current sampling circuit and a second current sampling circuit. The first current sampling circuit may be connected to the first heating film 12 through the power module 6, and is used to collect the current passing through the first heating film 12. The second current sampling circuit may be connected to the second heating film 13 through the power module 6, and is used to collect the current passing through the second heating film 13. The voltage sampling circuit 72 may be connected to the power module 6 through a signal processing circuit 74, and is used to collect the voltage across the heating unit 1. The signal processing circuit 74 converts the collected voltage into a voltage detection signal and sends it to the power module 6. Specifically, the voltage sampling circuit 72 may include a first voltage sampling circuit connected to the first heating film 12 and a second voltage sampling circuit connected to the second heating film 13, and respectively obtains the voltage across the first heating film 12 and the second heating film 13. The temperature sampling circuit 73 is connected to the heating unit 1, and is used to collect the temperature detection signal of the heating unit 1 according to the current temperature of the heating unit 1. Specifically, the temperature sampling circuit 73 may include a first temperature sampling circuit 73 arranged near the first heating film 12, and a second temperature sampling circuit 73 arranged near the second heating film 13, which respectively collect the temperatures of the first heating film 12 and the second heating film 13.

[0044] The controller 8 is connected to the current sampling circuit 71, the voltage sampling circuit 72 and the temperature sampling circuit 73, and is used to control the operation of the power module 6 according to the current detection signal, the voltage detection signal and the temperature detection signal. For example, when it is detected that the current detection signal is greater than the preset current signal, the power module 6 is controlled to reduce the output power, or stop working, to prevent the heating unit 1 from overheating. In this example, the controller 8 can monitor the current of the power module 6, the voltage across the heating unit 1 and the current temperature of the heating unit 1 in real time, and control the operation of the power module 6 according to the acquired current detection signal, voltage detection signal and temperature detection signal, and can form feedback control on the heating unit 1 to ensure the normal operation of the heating unit 1.

[0045] In one embodiment, the power module 6 includes a drive circuit 61 and a power circuit 62; the power circuit 62 is connected to the heating unit 1 and is used to supply power to the heating unit 1; the drive circuit 61 is connected to the power circuit 62 and the controller 8 and is used to adjust the output power of the power circuit 62 under the control of the controller 8.

[0046] As an example, the power module 6 includes a drive circuit 61 and a power circuit 62; the power circuit 62 is connected to the heating unit 1 and is used to supply power to the heating unit 1; the drive circuit 61 is connected to the power circuit 62 and the controller 8 and is used to adjust the output power of the power circuit 62 under the control of the controller 8. Specifically, the drive circuit 61 can output a PWM signal to drive the power circuit 62, and the controller 8 can control and change the duty cycle of the PWM signal output by the drive circuit 61. PWM signals with different duty cycles can drive the power circuit 62 to output different electric powers, so as to adjust the power supply power of the heating unit 1, thereby controlling the heating temperature of the heating unit 1.

[0047] In one embodiment, the power circuit 62 includes a first control tube Q1 and a second control tube Q2; the first end of the first control tube Q1 is used to be connected to the first end of the power supply, the second end of the first control tube Q1 is connected to the second end of the power supply through the first heating film 12, and the third end of the first control tube Q1 is connected to the drive circuit 61; the first end of the second control tube Q2 is used to be connected to the first end of the power supply, the second end of the second control tube Q2 is connected to the second end of the power supply through the second heating film 13, and the third end of the second control tube Q2 is connected to the drive circuit 61.

[0048] As an example, the power circuit 62 includes a first control tube Q1 and a second control tube Q2. The first control tube Q1 may be an NMOS tube. The first end of the first control tube Q1 is the source of the NMOS tube, the second end of the first control tube Q1 is the drain of the NMOS tube, and the third end of the first control tube Q1 is the gate of the NMOS tube. The first end of the first control tube Q1 is connected to the first end of the power supply, such as the negative end, and the second end of the first control tube Q1 is connected to the second end of the power supply, such as the positive end, through the first heating film 12. The first control tube Q1 and the first heating film 12 form a heating loop. The third end of the first control tube Q1 is connected to the drive circuit 61, and is used to be turned on or off under the control of the drive circuit 61.

[0049] Similarly, the second control tube Q2 can also be an NMOS tube, the first end of the second control tube Q2 is the source of the NMOS tube, the second end of the second control tube Q2 is the drain of the NMOS tube, and the third end of the second control tube Q2 is the gate of the NMOS tube. The first end of the second control tube Q2 is connected to the first end of the power supply, such as the negative end, and the second end of the second control tube Q2 is connected to the second end of the power supply, such as the positive end, through the second heating film 13. The second control tube Q2 and the second heating film 13 form another heating loop, and the third end of the second control tube Q2 is connected to the drive circuit 61, which is used to turn on or off under the control of the drive circuit 61.

[0050] In one embodiment, the power circuit 62 further includes a first capacitor C1 and a second capacitor C2; the two ends of the first capacitor C1 are respectively connected to the first end and the second end of the first control tube Q1; the two ends of the second capacitor C2 are respectively connected to the first end and the second end of the second control tube Q2.

[0051] As an example, the power circuit 62 further includes a first capacitor C1 and a second capacitor C2; the first end of the first capacitor C1 is connected to the first end of the first control tube Q1, and the second end of the first capacitor C1 is connected to the second end of the first control tube Q1; the first end of the second capacitor C2 is connected to the first end of the second control tube Q2, and the second end of the second capacitor C2 is connected to the second end of the second control tube Q2. The first capacitor C1 and the second capacitor C2 play a filtering role to resist voltage fluctuations.

[0052] In one embodiment, the film heating circuit further includes an auxiliary power module 9 ; the auxiliary power module 9 is connected to the controller 8 and the drive circuit 61 for supplying power to the controller 8 and the drive circuit 61 .

[0053] As an example, the film heating circuit also includes an auxiliary power supply module 9, which is connected to the controller 8 and the drive circuit 61 and is used to supply power to the controller 8 and the drive circuit 61. When the auxiliary power supply module 9 is turned on, the controller 8 and the drive circuit 61 can first work in a standby state. The controller 8 controls the drive circuit 61 to start working by receiving a heating instruction sent by the host computer 14, and then the power circuit 62 starts working, so that the heating unit 1 starts heating.

[0054] In one embodiment, the film heating circuit further includes an isolation module 10 ; the controller 8 is connected to the host computer 14 via the isolation module 10 and is used for communicating with the host computer 14 .

[0055] As an example, the film heating circuit further includes an isolation module 10. One end of the isolation module 10 is connected to the controller 8, and the other end is connected to the host computer 14, for performing electrical isolation so that the host computer 14 and the controller 8 can communicate smoothly. The controller 8 is connected to the host computer 14 through the isolation module 10, and can send a fault signal to the host computer 14, and can also control the power module 6 to work according to the corresponding electric power according to the heating instruction sent back by the host computer 14, so that the heating temperature of the heating unit 1 is within a preset temperature range.

[0056] The embodiment of the present invention further provides a film heating control method, which is applied to the film heating circuit in any of the above embodiments. Figure 5 As shown, the controller performs the following steps: S501: Acquire a detection signal; S502: If the detection signal meets the fault assessment condition, a protection operation is performed; S503: If the detection signal does not meet the fault assessment condition, control the power module to operate.

[0057] As an example, in step S501, the controller 8 obtains the detection signal collected by the detection module 7, specifically, the detection signal may include the current detection signal collected by the current sampling circuit 71, may also include the voltage detection signal collected by the voltage sampling circuit 72, and may also include the temperature detection signal collected by the temperature sampling circuit 73. The controller 8 can judge the working state of the film heating circuit and the heating unit 1 according to the obtained detection signal, so as to identify the abnormal state of the film heating circuit and the heating unit 1 and perform corresponding protection operations.

[0058] As an example, in step S502, the controller 8 performs detection processing on the acquired detection signal, and when the detection signal meets the fault assessment condition, the corresponding protection operation is performed to prevent circuit failure. For example, the current current of the power module 6, that is, the current flowing through the first heating film 12 and the second heating film 13, can be obtained according to the current detection signal. By detecting the current current, the controller 8 can determine whether the first heating film 12 and the second heating film 13 are in an overcurrent state, and perform corresponding protection operations in the case of overcurrent to prevent the first heating film 12 or the second heating film 13 from being ablated or the power module 6 from failing.

[0059] As an example, in step S503, if the detection signal obtained by the controller 8 does not meet the fault assessment condition, it means that the current film heating circuit and the heating unit 1 are in normal working state, and the power module 6 can be controlled to work according to the preset control scheme to supply power to the heating unit 1.

[0060] In one embodiment, the fault assessment conditions include: the current current is greater than the preset current; or the current voltage is greater than the preset voltage; or the current temperature is greater than the preset temperature; performing a protection operation, including: controlling the shutdown of the power module 6 and sending a fault signal to the host computer 14.

[0061] As an example, the controller 8 calculates the current current based on the acquired current detection signal. If the current current is greater than the preset current, it means that the current power module 6 and the first heating film 12 and the second heating film 13 connected to the power module 6 are in an overcurrent state. At this time, the controller 8 sends a fault signal to the host computer 14 and controls to shut down the power module 6 to prevent the first heating film 12 or the second heating film 13 from overheating and burning, thereby preventing damage to the power module 6. Specifically, the current sampling circuit 71 may include a first current sampling circuit connected to the first heating film 12, and a second current sampling circuit connected to the second heating film 13. The controller 8 obtains a first current detection signal fed back by the first current sampling circuit, and a second current detection signal fed back by the second current sampling circuit, and obtains a first working current currently flowing through the first heating film 12 and a second working current flowing through the second heating film 13. By judging whether the first working current and the second working current are greater than a preset current, it can be judged whether the first heating film 12 and the second heating film 13 are in an overcurrent state, and when the first heating film 12 is in an overcurrent state, the first control tube Q1 connected to the first heating film 12 in the power module 6 is turned off, and when the second heating film 13 is in an overcurrent state, the second control tube Q2 connected to the second heating film 13 in the power module 6 is turned off.

[0062] As another example, the controller 8 calculates the current voltage based on the acquired voltage detection signal. If the current voltage is greater than the preset voltage, it means that the current power module 6 and the first heating film 12 and the second heating film 13 connected to the power module 6 are in an overvoltage state. At this time, the controller 8 sends a fault signal to the host computer 14 and controls to shut down the power module 6 to prevent damage to the first heating film 12 or the second heating film 13 or the power module 6. Specifically, the voltage sampling circuit 72 may include a first voltage sampling circuit connected to the first heating film 12, and a second voltage sampling circuit connected to the second heating film 13. The controller 8 obtains a first voltage detection signal fed back by the first voltage sampling circuit, and a second voltage detection signal fed back by the second voltage sampling circuit, and obtains the first working voltage at both ends of the first heating film 12 and the second working voltage at both ends of the second heating film 13. By judging whether the first working voltage and the second working voltage are greater than the preset voltage, it can be judged whether the first heating film 12 and the second heating film 13 are in an overvoltage state, and when the first heating film 12 is in an overvoltage state, the first control tube Q1 connected to the first heating film 12 in the power module 6 is turned off, and when the second heating film 13 is in an overvoltage state, the second control tube Q2 connected to the second heating film 13 in the power module 6 is turned off.

[0063] As another example, the controller 8 calculates the current temperature based on the acquired temperature detection signal. If the current temperature is greater than the preset temperature, it means that the temperature of the first heating film 12 and the second heating film 13 connected to the current power module 6 is too high. At this time, the controller 8 sends a fault signal to the host computer 14 and controls to shut down the power module 6 to prevent overheating and ablation of the first heating film 12 or the second heating film 13. Specifically, the temperature sampling circuit 73 may include a first temperature sampling circuit 73 connected to the first heating film 12, and a second temperature sampling circuit 73 connected to the second heating film 13. The controller 8 obtains a first temperature detection signal fed back by the first temperature sampling circuit 73, and a second temperature detection signal fed back by the second temperature sampling circuit 73, and obtains the current first operating temperature of the first heating film 12 and the second operating temperature of the second heating film 13. By judging whether the first operating temperature and the second operating temperature are greater than the preset temperature, it can be judged whether the first heating film 12 and the second heating film 13 are in an overheated state, and when the first heating film 12 is in an overheated state, the first control tube Q1 connected to the first heating film 12 in the power module 6 is turned off, and when the second heating film 13 is in an overheated state, the second control tube Q2 connected to the second heating film 13 in the power module 6 is turned off.

[0064] In one embodiment, the fault assessment conditions include: multiple temperature detection signals collected by the same heating film in multiple consecutive sampling cycles are the same; performing a protection operation, including: shutting off the control tubes corresponding to the heating films with the same temperature detection signals, and sending a fault signal to the host computer.

[0065] As an example, the controller 8 obtains the first temperature detection signal and the second temperature detection signal sent back by the first temperature sampling circuit 73 and the second temperature sampling circuit 73 according to the preset acquisition frequency. When the first temperature detection signals obtained in n consecutive sampling cycles (for example, 10 consecutive sampling cycles) are the same, it means that the first heating film 12 detected by the first temperature sampling circuit 73 is ablated or mechanically damaged, and the first control tube Q1 connected to the first heating film 12 needs to be turned off to disconnect the first heating film 12 from the power supply, stop supplying power to the first heating film 12, and prevent further failures. At the same time, the controller 8 also transmits a fault signal to the upper computer 14, indicating that the first heating film 12 is faulty and damaged. The second heating film 13 is the same.

[0066] In one embodiment, if Figure 6 As shown, the control power module works, including: S601: Obtaining the ambient temperature signal sent by the host computer; S602: Based on the ambient temperature signal, control the power module to output a corresponding PWM signal.

[0067] As an example, in step S601, the controller 8 receives an ambient temperature signal sent by the host computer 14, which may be a temperature signal obtained by the host computer 14 through temperature detection of a component that currently requires heating by a film heater, such as a cabin, a battery, etc.

[0068] As an example, in step S602, the controller 8 calculates the heating temperature required for the heating unit 1 based on the ambient temperature signal, and adjusts the duty cycle of the PWM signal output by the drive circuit 61 according to the heating temperature, so that the power circuit 62 outputs the corresponding electric power, and finally enables the heating unit 1 to reach the required heating temperature.

[0069] In one embodiment, if Figure 7 As shown, in step S501, that is, before obtaining the detection signal, the film heating control method further includes: S701: Perform self-inspection on the current function based on preset inspection rules; S702: If the current function is in a normal state, a heating instruction sent by the host computer is obtained, and the power module is controlled to work according to the heating instruction; S703: If the current function is in an abnormal state, a fault signal is sent to the upper computer.

[0070] As an example, in step S701, after the auxiliary power module 9 is turned on and the controller 8 is powered on, the controller 8 first performs a self-check on its own functions, for example, a self-check on the communication function with the host computer 14, and a self-check on the signal acquisition function with the detection module 7, etc., to ensure that it is working in a normal state, so as to ensure that the control process can proceed smoothly.

[0071] As an example, in step S702, if the controller 8 checks and determines that its current function is in a normal state, it continues to receive the heating instruction sent by the host computer 14, and after receiving the heating instruction, controls the drive circuit 61 in the power module 6 to output the corresponding PWM signal to the power circuit 62 to power the heating unit 1.

[0072] As an example, in step S703, if the controller 8 checks and determines that its current function is in an abnormal state, a fault signal is sent to the upper computer 14 to prompt the controller 8 to fail, so as to actively eliminate the abnormal situation and facilitate maintenance.

[0073] An embodiment of the present invention further provides a film heating device, comprising the film heater in any of the above embodiments and the film heating circuit in any of the above embodiments, wherein the film heating circuit is used to execute the film heating control method in any of the above embodiments. Figure 5 S501-S503 are shown.

[0074] As an example, the film heating device includes the film heater in any of the above examples and the film heating circuit in any of the above examples, and the film heating circuit can execute the film heating control method in any of the above examples. In this example, the heating unit 1 in the film heating device is provided with a first heating film 12 and a second heating film 13 in parallel on the substrate 11, so that when any one of the first heating film 12 and the second heating film 13 stops working, the heated area of ​​the substrate 11 does not change significantly, so that the substrate 11 still maintains a uniform heating state, and avoids uneven thermal stress causing the heating film to fall off and be damaged. The flow guide component 3 in the film heating device forms a flow guide cavity between the shell 2, which can buffer the fluid that has just entered the shell 2, and can also make the fluid that is about to flow out of the shell 2 fully mixed again in the steady flow cavity 31, so that the temperature of the fluid flowing into and out of the shell 2 is more uniform and constant, thereby making the heating temperature of the film heating device more stable and controllable. The controller 8 in the membrane heating circuit can monitor the current of the power module 6, the voltage across the heating unit 1, and the current temperature of the heating unit 1 in real time, and control the operation of the power module 6 according to the acquired current detection signal, voltage detection signal, and temperature detection signal, thereby forming feedback control on the heating unit 1 and ensuring the normal operation of the heating unit 1.

[0075] The embodiments described above are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that the technical solutions described in the aforementioned embodiments may still be modified, or some of the technical features may be replaced by equivalents. Such modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention, and should all be included in the protection scope of the present invention.

Claims

1. A heating unit, characterized in that: It includes a substrate, a first heating film and a second heating film; The first heating film and the second heating film are arranged on the substrate in parallel and at intervals; The first heating film and the second heating film are used to be connected to a film heating circuit.

2. The heating unit according to claim 1, characterized in that: The first heating film is arranged in a serpentine shape, and the second heating film is arranged in a serpentine shape; The first heating films and the second heating films are arranged alternately.

3. A film heater, characterized in that: A heating device comprising a housing and a heating unit according to any one of claims 1 to 2; The heating unit is arranged in the shell, and a base plate of the heating unit is connected to an inner wall of the shell.

4. The film heater according to claim 3, characterized in that The film heater also includes two flow guide components, a heater inlet and a heater outlet; The two flow guide components are respectively arranged on both sides of the heating unit; Each of the flow guide components cooperates with the shell to form a steady flow cavity, and the heater outlet and the heater inlet are respectively arranged opposite to one of the steady flow cavities.

5. The film heater according to claim 4, characterized in that The flow guide assembly includes at least one flow guide plate; One end of each of the guide plates is connected to an inner wall of the shell; At least one of the guide plates and the heating unit are arranged alternately to form a serpentine guide channel between at least one of the guide plates and the heating unit; A guide plate farthest from the heating unit cooperates with the shell to form a steady flow cavity; A heater inlet or a heater outlet is provided on the inner wall of the shell corresponding to the flow stabilizing cavity.

6. A film heating circuit, characterized in that: Used to be connected to the heating unit according to any one of claims 1 to 2, the film heating circuit comprising a power module, a detection module and a controller; The power module is connected to the heating unit and is used to supply power to the heating unit; The detection module is connected to the heating unit and the power module and is used to collect detection signals; The controller is connected to the power module and the detection module, and controls the power module to work according to the detection signal output by the detection module.

7. The film heating circuit according to claim 6, characterized in that The detection module includes a current sampling circuit, a voltage sampling circuit and a temperature sampling circuit; The current sampling circuit is connected to the power module and is used to collect the current detection signal of the power module; The voltage sampling circuit is connected to the heating unit and is used to collect the voltage detection signal of the heating unit; The temperature sampling circuit is connected to the heating unit and is used to collect the temperature detection signal of the heating unit; The controller is connected to the current sampling circuit, the voltage sampling circuit and the temperature sampling circuit, and is used to control the operation of the power module according to the current detection signal, the voltage detection signal and the temperature detection signal.

8. The film heating circuit according to claim 6, characterized in that The power module includes a drive circuit and a power circuit; The power circuit is connected to the heating unit and is used to supply power to the heating unit; The driving circuit is connected to the power circuit and the controller, and is used to adjust the output power of the power circuit under the control of the controller.

9. The film heating circuit according to claim 8, characterized in that The power circuit includes a first control tube and a second control tube; The first end of the first control tube is used to be connected to the first end of the power supply, the second end of the first control tube is connected to the second end of the power supply through the first heating film, and the third end of the first control tube is connected to the driving circuit; The first end of the second control tube is used to connect to the first end of the power supply, the second end of the second control tube is connected to the second end of the power supply through the second heating film, and the third end of the second control tube is connected to the driving circuit.

10. The film heating circuit according to claim 9, characterized in that The power circuit also includes a first capacitor and a second capacitor; Two ends of the first capacitor are respectively connected to a first end and a second end of the first control tube; Two ends of the second capacitor are connected to the first end and the second end of the second control tube respectively.

11. The film heating circuit according to claim 8, characterized in that The film heating circuit also includes an auxiliary power supply module; The auxiliary power supply module is connected to the controller and the drive circuit, and is used to supply power to the controller and the drive circuit.

12. The film heating circuit according to claim 6, characterized in that The film heating circuit also includes an isolation module; The controller is connected to the host computer through the isolation module and is used for communicating with the host computer.

13. A film heating control method, characterized in that: The method is applied in a film heating circuit as claimed in any one of claims 6 to 12, comprising the following steps performed by a controller: Get the detection signal; If the detection signal meets the fault assessment condition, a protection operation is performed; If the detection signal does not meet the fault assessment condition, the power module is controlled to operate.

14. The film heating control method according to claim 13, characterized in that: The fault assessment conditions include: the current current is greater than the preset current; or the current voltage is greater than the preset voltage; or the current temperature is greater than the preset temperature; The executing protection operation includes: controlling to shut down the power module and sending a fault signal to a host computer.

15. The film heating control method according to claim 13, characterized in that: The fault assessment conditions include: multiple temperature detection signals collected by the same heating film in multiple consecutive sampling periods are the same; The execution of the protection operation includes: shutting down control tubes corresponding to a plurality of heating films having the same temperature detection signals, and sending a fault signal to a host computer.

16. The film heating control method according to claim 13, characterized in that: The control power module operation includes: Get the ambient temperature signal sent by the host computer; Based on the ambient temperature signal, the power module is controlled to output a corresponding PWM signal.

17. The film heating control method according to claim 13, characterized in that: Before acquiring the detection signal, the film heating control method further includes: Perform self-inspection on the current function based on preset inspection rules; If the current function is in a normal state, a heating instruction sent by the host computer is obtained, and the power module is controlled to work according to the heating instruction; If the current function is in an abnormal state, a fault signal will be sent to the host computer.

18. A film heating device, characterized in that: The invention comprises the film heater according to any one of claims 3 to 5 and the film heating circuit according to any one of claims 6 to 12, wherein the film heating circuit is used to execute the film heating control method according to any one of claims 13 to 17.

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