Safe electric heater

Abstract

The utility model relates to a safe electric heater, which starts from a time delay relay KD and an alternating current contactor KM, carries out a brand new circuit connection design, and aims at supplying power to a cooling fan through a normally closed switch group of the time delay relay KD and supplying power to an electric heating device H through a normally open switch group of the alternating current contactor KM. A coil of a time delay relay KD and a coil of an alternating current contactor KM form a detection subsystem, a second rotary temperature controller T2 is introduced into the detection subsystem, and through detection of the environment temperature where an electric heating device H is located, power supply control is conducted on the electric heating device H through the detection subsystem, detection of the environment temperature is achieved, and control over work of the electric heating device H is achieved. And the use efficiency and the use safety of the electric heater are improved.

Description

Technical Field

[0001] The utility model relates to a safety electric heater, belonging to the technical field of safety heating tools. Background Art

[0002] In general existing electric heaters, the internal electrical components and heating elements are too close. After working for a long time, if the heat dissipation environment is not good, the internal electrical components of the electric heater will be damaged. In addition, the cooling fan inside the existing electric heater uses a delay relay to control the on and off. When the cooling fan motor is running, it will vibrate, which can easily cause the coil of the delay relay to pop out of the base, thereby causing the cooling fan to stop or even damage the cooling fan motor. At the same time, the internal heating element continues to heat up, which will further cause the heating element or electrical components to burn out, affecting the safe use and electrical life of the electric heater. Utility Model Content

[0003] The technical problem to be solved by the utility model is to provide a safe electric heater, which starts with a time delay relay KD and an AC contactor KM, carries out a new circuit connection design, controls the power supply of the electric heating element H through detection, and improves the efficiency and safety of the electric heater.

[0004] In order to solve the above technical problems, the present invention adopts the following technical solutions: The present invention designs a safe electric heater, including an electric control system, an electric heating device H, and a cooling fan, wherein the power taking end of the electric control system is connected to an external power supply for power taking, and the electric control system includes a time delay relay KD and an AC contactor KM. The power taking end of the electric control system is connected to the motor M of the cooling fan via the normally closed switch group of the internal time delay relay KD for power supply, and the power taking end of the electric control system is connected to the electric heating device H via the normally open switch group of the internal AC contactor KM for power supply; at the same time, a detection subsystem is constructed inside the electric control system by the coil of the time delay relay KD and the coil of the AC contactor KM, and the detection subsystem is used for safety detection, and controls the normally open switch group of the AC contactor KM, and then controls the power supply to the electric heating device H.

[0005] As a preferred technical solution of the present invention: each phase line power taking end of the electric control system corresponds to each power supply phase line of the external power supply and is respectively connected to draw power, and the neutral line end of the electric control system is connected to the neutral line of the external power supply, each phase line power taking end of the electric control system is connected to the motor M of the cooling fan via each switch in the normally closed switch group of the internal delay relay KD for power supply, and each phase line power taking end of the electric control system is connected to the electric heating device H via each switch in the normally open switch group of the internal AC contactor KM for power supply;

[0006] The electronic control system also includes a second rotary temperature controller T2 with a temperature detection function. Based on the definition of any phase line in the power supply end of the electronic control system as the target phase line, in the structure of the detection subsystem within the electronic control system, one end of the coil of the AC contactor KM is connected to the connection line between the normally closed switch group of the time delay relay KD and the motor M of the cooling fan corresponding to the target phase line. The other end of the coil of the AC contactor KM is connected in series with the second rotary temperature controller T2, and then further connected to the neutral line end of the power supply end of the electronic control system and one end of the normally closed switch of the AC contactor KM. The other end of the normally closed switch of the AC contactor KM is connected to one end of the coil of the time delay relay KD, and the other end of the coil of the time delay relay KD is connected to the phase line power supply end corresponding to the target phase line in the power supply end of the electronic control system. The second rotary temperature controller T2 is used to detect the ambient temperature of the electric heating device H, and controls the normally open switch group of the AC contactor KM through the detection subsystem, thereby controlling the power supply to the electric heating device H.

[0007] As an optimal technical solution of the present invention: the electronic control system also includes a first rotary temperature control T1. In the structure of the detection subsystem inside the electronic control system, one end of the coil of the AC contactor KM is connected in series with the first rotary temperature control T1, and then further connected to the normally closed switch group of the delay relay KD and the corresponding target phase line between the motor M of the cooling fan.

[0008] As an optimal technical solution of the present invention: the electric control system also includes an air switch group QF, and the phase line power supply end and the neutral line end of the electric control system are connected to the phase lines and the neutral line of the external power supply through the air switch group QF.

[0009] As a preferred technical solution of the present invention: it also includes an electrical box, an electric heater housing, and a bracket, wherein the electric heating device H and the cooling fan are arranged in the electric heater housing, the electric control system is arranged in the electrical box, the electrical box is connected to the surface of the electric heater housing through the bracket, and a preset spacing gap is maintained between the electrical box and the electric heater housing.

[0010] The safety electric heater described in the utility model adopts the above technical solution and has the following technical effects compared with the prior art:

[0011] The utility model designs a safe electric heater. Starting from a time delay relay KD and an AC contactor KM, a new circuit connection design is carried out. In order to supply power to a cooling fan via a normally closed switch group of the time delay relay KD and to supply power to an electric heating element H via a normally open switch group of the AC contactor KM, a detection subsystem is constructed using the coil of the time delay relay KD and the coil of the AC contactor KM. A second rotary temperature control T2 is introduced into the detection subsystem. By detecting the ambient temperature of the electric heating element H, the power supply to the electric heating element H is controlled via the detection subsystem, thereby realizing detection of the ambient temperature and controlling the operation of the electric heating element H, thereby improving the use efficiency and safety of the electric heater. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 This is the electrical principle diagram of the safety electric heater designed by this utility model. DETAILED DESCRIPTION

[0013] The specific implementation of the present invention will be further described in detail below with reference to the accompanying drawings.

[0014] The present utility model designs a safety electric heater. In actual application, the specific design includes an electric control system, an electric heating device H, and a cooling fan. As shown in Question 1, the power-taking end of the electric control system is connected to an external power supply for power supply. The electric control system includes a time delay relay KD and an AC contactor KM. The power-taking end of the electric control system is connected to the motor M of the cooling fan via the normally closed switch group of the internal time delay relay KD for power supply, and the power-taking end of the electric control system is connected to the electric heating device H via the normally open switch group of the internal AC contactor KM for power supply. At the same time, a detection subsystem is constructed by the coil of the time delay relay KD and the coil of the AC contactor KM inside the electric control system. The detection subsystem is used for safety detection and controls the normally open switch group of the AC contactor KM, thereby controlling the power supply to the electric heating device H.

[0015] In the specific implementation of the above scheme, as shown in Question 1, the design of the electric control system also includes an air switch group QF. The phase power-taking ends and the neutral line end in the power-taking end of the electric control system are connected to the phase lines and the neutral line of the external power supply through the air switch group QF, such as the three-phase power supply lines U, V, W, and the neutral line N based on the external power supply. The three-phase power-taking ends in the power-taking end of the electric control system are connected to the three-phase power supply lines U, V, and W of the external power supply corresponding to each switch in the air switch group QF for power supply, and the neutral line end in the power-taking end of the electric control system is connected to the neutral line N of the external power supply through the switch in the air switch group QF. In addition, the three-phase power-taking ends in the power-taking end of the electric control system are designed to be connected to the motor M of the cooling fan through each switch in the normally closed switch group of the internal delay relay KD for power supply, and the three-phase power-taking ends in the power-taking end of the electric control system are connected to the electric heating device H through each switch in the normally open switch group of the internal AC contactor KM for power supply.

[0016] In actual applications, the specific design of the electronic control system also includes a first rotating temperature controller T1 and a second rotating temperature controller T2 with a temperature detection function, and is connected to the three-phase power supply scenario of the external power supply, as shown in Question 1. For example, the power supply phase line W in the power supply end of the electronic control system is defined as the target phase line. In the specific structural design of the detection subsystem inside the electronic control system, one end of the coil of the AC contactor KM is connected in series with the first rotating temperature controller T1, and then connected to the connection between the normally closed switch group of the delay relay KD and the motor M of the cooling fan corresponding to the power supply phase line W. The other end of the coil of the AC contactor KM is connected in series with the second rotating temperature controller T2, and then connected to the neutral line end of the power supply end of the electronic control system. One end of the coil of the delay relay KD is connected in series with the normally closed switch of the AC contactor KM, and then connected to the neutral line end of the power supply end of the electronic control system. The other end of the coil of the delay relay KD is connected to the phase line power supply end corresponding to the target phase line in the power supply end of the electronic control system.

[0017] According to the structural design of the above-mentioned detection subsystem, in application, the second rotary temperature control T2 is used to detect the ambient temperature of the electric heating device H, and the normally open switch group of the AC contactor KM is controlled through the detection subsystem, thereby controlling the power supply to the electric heating device H.

[0018] Applying the above design scheme in practice, as shown in Question 1, the normally closed switch group of the initialization delay relay KD is closed, the normally open switch group of the AC contactor KM is disconnected, and the second rotary temperature control T2 is closed to complete the initialization operation. Then, in actual application, when only the air switch group QF is closed, that is, when the first rotary temperature control T1 is disconnected, the external power supply is supplied to the cooling fan motor M through the air switch group QF and the normally closed switch group of the delay relay KD, and the cooling fan starts to work. However, since the coil of the contactor KM is not energized, the normally open switch group of the AC contactor KM remains disconnected, and the normally closed switch of the AC contactor KM remains closed, the electric heating element H does not work, and the delay relay KD is energized to start timing. When the timing reaches the set time, the normally closed switch group of the delay relay KD is disconnected, and the cooling fan stops working. Here, the process is that when only the air switch group QF is closed and the first rotary temperature control T1 is disconnected, the electric heating element H does not work, and the cooling fan stops after working for a period of time, thus protecting the entire system.

[0019] After the above initialization operation, the air switch group QF is closed, and the first rotary temperature control T1 is closed, then the external power supply is used to supply power to the motor M of the cooling fan through the air switch group QF and the normally closed switch group of the time delay relay KD, and further supplies power to the AC contactor KM through the first rotary temperature control T1. Then the cooling fan starts to work, the AC contactor KM is energized, so that the normally open switch group of the AC contactor KM is closed and the normally closed switch of the AC contactor KM is disconnected, then the electric heating device H starts to work, but at this time the time delay relay KD is not energized, that is, the normally closed switch group of the time delay relay KD is kept closed, that is, the cooling fan keeps working. Here, the process is to close the air switch group QF, and when the first rotary temperature control T1 is closed, the electric heating device H and the cooling fan start to work synchronously. While the electric heating device H is working and heating, the cooling fan dissipates heat to the environment where the electric heating device H is located.

[0020] During the synchronous operation of the above-mentioned electric heating device H and the cooling fan, the second rotary temperature control T2 in the closed state detects the ambient temperature of the electric heating device H in real time. When a fault causes the cooling fan motor M to burn out and the cooling fan stops, the ambient temperature of the electric heating device H continues to rise. When the ambient temperature rises to a preset temperature upper limit, such as 280°C, the second rotary temperature control T2 for detecting the ambient temperature trips, and the local circuit where the coil of the AC contactor KM is located is disconnected, that is, the coil of the AC contactor KM loses power, causing the normally open switch group of the AC contactor KM to be disconnected and the normally closed switch of the AC contactor KM to be closed, thereby cutting off the power supply to the electric heating device H, and the electric heating device H stops working, thereby protecting the electric heating device H. At the same time, since the normally closed switch of the AC contactor KM is closed, the time delay relay KD is energized and starts timing. When the timing reaches the set time, the normally closed switch group of the delay relay KD is disconnected, that is, the power supply to the cooling fan is cut off.

[0021] The above design scheme starts with the time delay relay KD and the AC contactor KM, and carries out a new circuit connection design. In order to supply power to the cooling fan through the normally closed switch group of the time delay relay KD, and to supply power to the electric heating device H through the normally open switch group of the AC contactor KM, a detection subsystem is constructed with the coil of the time delay relay KD and the coil of the AC contactor KM, and a second rotary temperature control T2 is introduced into the detection subsystem. By detecting the ambient temperature of the electric heating device H, the power supply to the electric heating device H is controlled through the detection subsystem, thereby realizing the detection of the ambient temperature, controlling the operation of the electric heating device H, and improving the efficiency and safety of the electric heater.

[0022] In actual application, the above-mentioned safety electric heater design scheme is further designed to include an electrical box, an electric heater shell, and a bracket, wherein the electric heating device H and the cooling fan are arranged in the electric heater shell, and the electronic control system is arranged in the electrical box. The electrical box is connected to the surface of the electric heater shell through the bracket, and a preset spacing gap is maintained between the electrical box and the electric heater shell; such a design isolates the electrical box of the electrical component separately, and at the same time isolates it from the electric heater shell, so as to avoid the electrical component being burned due to the electrical heating device H being too close, and at the same time facilitates future maintenance and replacement of electrical components.

[0023] The embodiments of the present invention are described in detail above with reference to the accompanying drawings. However, the present invention is not limited to the above embodiments. Various changes can be made within the scope of knowledge possessed by ordinary technicians in this field without departing from the purpose of the present invention.

Claims

1. A safety electric heater, characterized by: It includes an electronic control system, an electric heating device H, and a cooling fan, wherein the power-taking end of the electronic control system is connected to an external power supply for power. The electronic control system includes a time delay relay KD and an AC contactor KM. The power-taking end of the electronic control system is connected to the motor M of the cooling fan via the normally closed switch group of the internal time delay relay KD for power supply, and the power-taking end of the electronic control system is connected to the electric heating device H via the normally open switch group of the internal AC contactor KM for power supply; at the same time, a detection subsystem is constructed inside the electronic control system by the coil of the time delay relay KD and the coil of the AC contactor KM. The detection subsystem is used for safety detection and controls the normally open switch group of the AC contactor KM, thereby controlling the power supply to the electric heating device H.

2. A safety electric heater according to claim 1, characterized in that: Each phase line power taking end of the electric control system corresponds to each power supply phase line of the external power supply and is connected to draw power, and the neutral line end of the electric control system is connected to the neutral line of the external power supply, each phase line power taking end of the electric control system is connected to the motor M of the cooling fan via each switch in the normally closed switch group of the internal delay relay KD for power supply, and each phase line power taking end of the electric control system is connected to the electric heating device H via each switch in the normally open switch group of the internal AC contactor KM for power supply; The electronic control system also includes a second rotary temperature controller T2 with a temperature detection function. Based on the definition of any phase line in the power supply end of the electronic control system as the target phase line, in the structure of the detection subsystem within the electronic control system, one end of the coil of the AC contactor KM is connected to the connection line between the normally closed switch group of the time delay relay KD and the motor M of the cooling fan corresponding to the target phase line. The other end of the coil of the AC contactor KM is connected in series with the second rotary temperature controller T2, and then further connected to the neutral line end of the power supply end of the electronic control system and one end of the normally closed switch of the AC contactor KM. The other end of the normally closed switch of the AC contactor KM is connected to one end of the coil of the time delay relay KD, and the other end of the coil of the time delay relay KD is connected to the phase line power supply end corresponding to the target phase line in the power supply end of the electronic control system. The second rotary temperature controller T2 is used to detect the ambient temperature of the electric heating device H, and controls the normally open switch group of the AC contactor KM through the detection subsystem, thereby controlling the power supply to the electric heating device H.

3. A safety electric heater according to claim 2, characterized in that: The electronic control system also includes a first rotary temperature control T1. In the structure of the detection subsystem inside the electronic control system, one end of the coil of the AC contactor KM is connected in series with the first rotary temperature control T1, and then further connected to the normally closed switch group of the delay relay KD and the corresponding target phase line between the motor M of the cooling fan.

4. A safety electric heater according to claim 2, characterized in that: The electric control system further includes an air switch group QF, and each phase line power supply terminal and a neutral line terminal of the electric control system power supply terminal are connected to each phase line and a neutral line of an external power supply through the air switch group QF.

5. A safety electric heater according to any one of claims 1 to 4, characterized in that: It also includes an electrical box, an electric heater housing, and a bracket, wherein the electric heating device H and the cooling fan are arranged in the electric heater housing, the electric control system is arranged in the electrical box, the electrical box is connected to the surface of the electric heater housing through the bracket, and a preset spacing gap is maintained between the electrical box and the electric heater housing.

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