Electric heating tube explosion-proof early warning device

Abstract

The application discloses an explosion-proof early warning device for an electric heating tube, which comprises a three-way circuit breaker QS, a three-way fuse FU, a three-way alternating current contactor KM, three-way alternating current transformers LH1, LH2 and LH3, a self-resetting temperature controller, a manual reset temperature controller, a current detection controller, a resistance sensor RH, a power switch SA1, a heating signal control switch SA2, a motor M and a capacitor C, wherein one end of the three-way circuit breaker QS is connected with 380V fire line three-phase input ends L1, L2 and L3 respectively. During factory inspection, the voltage of the equipment to which the electric heating tube belongs is adjusted to the rated voltage through a voltage regulator, and after a period of stable operation, the resistance value and the current of the equipment are detected, and the detected resistance value and current value are set as standard values. When the fan equipment connected with the electric heating tube is blocked at the air inlet or the motor is stuck, the self-resetting temperature controller is disconnected after the self-resetting temperature rises to the set value, so that the alternating current contactor is disconnected, and the fan equipment for heat dissipation of the electric heating tube is cut off after a second time delay.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of electric heating tube, and particularly relates to an electric heating tube explosion-proof early warning device. BACKGROUND

[0002] An electric heating tube (electric heating tube) is a component that converts electric energy into heat energy and is widely used in industrial, household and commercial fields. During the use of the electric heating tube, the explosion (breakage or burst) of the electric heating tube will not only cause damage to the equipment, but also may cause serious safety accidents.

[0003] The hazards of the common electric heating tube explosion are as follows: (1) equipment damage and function failure. After the explosion of the electric heating tube, the electric heating tube cannot work normally, which causes the paralysis of the entire heating system (such as the non-heating of a water heater and the out-of-control temperature of an industrial reaction kettle). The internal resistance wire is exposed, which may cause the burning of a temperature controller, a fuse or other circuit components. (2) medium leakage. If the electric heating tube is used for liquid heating (such as a boiler and a water tank), the explosion of the electric heating tube may cause the leakage of water, oil or chemical medium, which pollutes the environment or damages other equipment. In an industrial scene, the leakage of corrosive liquid (acid and alkali) may cause secondary accidents. (3) electrical safety hazards. Electric shock risk - after the explosion of the electric heating tube, the metal shell or the resistance wire contacts the medium (such as water), which may cause an electric shock accident. Short-circuit fire - the internal circuit short-circuit may generate an electric arc, which ignites the surrounding combustible materials (such as plastic and oil stains).

[0004] The hazards of the electric heating tube explosion show that it is necessary to discover and prevent the risk of the electric heating tube explosion in time. SUMMARY

[0005] In view of the above problems, the application provides an electric heating tube explosion-proof early warning device for giving an early warning before the explosion of the electric heating tube, so as to improve the safety of the use of the electric heating tube.

[0006] To solve the above technical problems, the application adopts the following technical scheme:

[0007] The explosion-proof early warning device of the electric heating tube comprises three-way circuit breaker QS, three-way fuse FU, three-way AC contactor KM, three-way AC current transformer LH1, LH2 and LH3, self-resetting temperature controller, manual reset temperature controller, current detection controller, resistance sensor RH, power switch SA1, heating signal control switch SA2, motor M and capacitor C, wherein one end of the three-way circuit breaker QS is connected with 380V fire line three-phase input end L1, L2 and L3 respectively, the other end of the three-way circuit breaker QS is connected with one end of the three-way fuse FU, the other end of the three-way fuse FU is connected with one end of the three-way AC contactor KM, the other end of the three-way AC contactor KM is connected with one end of Y-type three-phase electric heating tube R1, R2 and R3 through the three-way current transformer LH1, LH2 and LH3, one end of the three-way current transformer LH1, LH2 and LH3 is connected with three input ends of the current detection controller respectively, 380V zero line N input end is connected with one end of the self-resetting temperature controller, one end of the power indicator lamp and one input end of the current detection controller respectively, the other end of the self-resetting temperature controller is connected with one end of the manual reset temperature controller, the other end of the manual reset temperature controller is connected with the coil one contact point of the KM, the other contact point of the KM coil is connected with the P1 input end of the current detection controller, the other end of the fuse of the fire line L3 is connected with one end of the power switch, the other end of the power switch is connected with the other end of the power indicator lamp, the fire line input end of the current detection controller and one input end of the heating signal control switch SA2, the other end of the heating signal control switch SA2 is connected with the P2 input end of the current detection controller, three output ends of the current detection controller are connected with L1 alarm indicator lamp, L2 alarm indicator lamp and L3 alarm indicator lamp respectively, the heating signal control switch SA2 is connected with the signal port of the digital display temperature controller or the ring temperature controller; four lead wires are arranged on the motor M, two of which are connected with the capacitor, and the other two are connected with the fan signal port in the integrated electric control cabinet.

[0008] In a possible implementation, during factory inspection, the voltage of the equipment to which the electric heating tube belongs is adjusted to the rated voltage through the voltage regulator, and after a period of stable operation in the energized state, the resistance value and the current of the equipment are detected, and the detected resistance value and current value are set as standard values.

[0009] In a possible implementation, when the fan equipment connected with the electric heating tube is blocked at the air inlet or the motor is stuck, after the self-resetting temperature rises to the set value, the self-resetting temperature controller is disconnected, so that the AC contactor is disconnected, and the fan equipment for dissipating heat of the electric heating tube is cut off after a second time delay.

[0010] In a possible implementation, when the self-resetting temperature controller fails, the fan equipment connected with the electric heating tube is blocked or the motor is stuck, the temperature continues to rise, and after the manually reset temperature rises to the set value of the manually reset temperature controller, the manually reset temperature controller is disconnected, so that the AC contactor KM is disconnected, and the power supply is cut off.

[0011] In a possible implementation, after the first start, the standard value of the circuit current is detected by the three mutual inductors, when any mutual inductor detects that the current I in the circuit is greater than or equal to the standard value*K1, the corresponding alarm indicator blinks 3 seconds / once, K1 is 1.2-2, and an alarm buzzer is sounded, when the abnormality is eliminated, the power is turned off, and the reset is performed after restarting.

[0012] In a possible implementation, after the first start, the standard value of the circuit current is detected by the three mutual inductors, when any mutual inductor detects that the current I in the circuit is less than or equal to the standard value*K2, the corresponding alarm indicator blinks 3 seconds / once, K2 is 0.3-0.8, and an alarm buzzer is sounded, when the abnormality is eliminated, the power is turned off, and the reset is performed after restarting.

[0013] In a possible implementation, the resistance sensor RH further acquires the resistance value of the electric heating tube in real time.

[0014] The on-off state of the fan and / or the contact of the AC contactor is controlled according to the size relationship between the resistance value and the resistance threshold value.

[0015] In a possible implementation, the control of the on-off state of the cooling mechanism and / or the contact of the AC contactor according to the size relationship between the resistance value and the resistance threshold value comprises:

[0016] If the resistance value is greater than the resistance threshold value, the contact of the AC contactor is controlled to be disconnected, and the fan is controlled to continue to run for a preset time length, and then the power supply is cut off.

[0017] The application has the following beneficial effects: the explosion prevention prediction and early warning of the electric heating tube can be effectively realized, and the safety and effectiveness of the electric heating tube are greatly improved. BRIEF DESCRIPTION OF DRAWINGS

[0018] Figure 1 The circuit principle diagram of the electric heating tube explosion prevention early warning device is shown. DETAILED DESCRIPTION

[0019] With reference to the accompanying drawings, the technical solutions in the embodiments of the present application will be clearly and completely described below. Obviously, the described embodiments are only some of the embodiments of the present application, rather than all the embodiments of the present application. Based on the embodiments of the present application, all other embodiments obtained by those of ordinary skill in the art without creative effort should fall within the scope of the present application.

[0020] Referring to Figure 1 , a circuit schematic diagram of an electric heating tube explosion-proof early warning device is shown, which comprises three-way circuit breakers QS, three-way fuses FU, three-way AC contactors KM, three-way AC current transformers LH1, LH2 and LH3, a self-resetting temperature controller, a manual reset temperature controller, a current detection controller, a resistance sensor RH, a power switch SA1, a heating signal control switch SA2, a motor M and a capacitor C. One end of the three-way circuit breakers QS is connected to 380V fire line three-phase input terminals L1, L2 and L3, respectively. The other end of the three-way circuit breakers QS is connected to one end of the three-way fuses FU. The other end of the three-way fuses FU is connected to one end of the three-way AC contactors KM. The other end of the three-way AC contactors KM is connected to one end of Y-type three-phase electric heating tubes R1, R2 and R3 through the three-way current transformers LH1, LH2 and LH3. One terminal of the three-way current transformers LH1, LH2 and LH3 is connected to three input terminals of the current detection controller, respectively. The 380V zero line N input terminal is connected to one end of the self-resetting temperature controller, one end of the power indicator lamp and one input terminal of the current detection controller, respectively. The other end of the self-resetting temperature controller is connected to one end of the manual reset temperature controller. The other end of the manual reset temperature controller is connected to the coil one contact of KM. The other contact of the KM coil is connected to the P1 input terminal of the current detection controller. The other end of the fuse of the fire line L3 is connected to one end of the power switch. The other end of the power switch is connected to the other end of the power indicator lamp, the fire line input terminal of the current detection controller and one input terminal of the heating signal control switch SA2. The other end of the heating signal control switch SA2 is connected to the P2 input terminal of the current detection controller. The three output terminals of the current detection controller are connected to the L1 alarm indicator lamp, the L2 alarm indicator lamp and the L3 alarm indicator lamp, respectively. The heating signal control switch SA2 is connected to the signal port of the digital display temperature controller or the ring temperature controller. Four leads are arranged on the motor M, two of which are connected to the capacitor, and the other two are connected to the fan signal port in the integrated electric control cabinet.

[0021] The electric heating tube explosion-proof early warning device is set as above. During factory inspection, the voltage of the electric heating tube is adjusted to the rated voltage by the voltage regulator. After a period of stable operation under the power-on state, the resistance value and the current of the device are detected. The detected resistance value and current value are set as standard values. The period of time may be, for example, 30 minutes.

[0022] After setting the standard values of resistance and current values, temperature control protection can be performed. When the fan equipment connected with the electric heating tube is blocked or the motor is stuck, the self-reset temperature rises to the set value, the self-reset temperature controller is disconnected, the AC contactor is disconnected, the fan equipment for heat dissipation of the electric heating tube is cut off after a second time, and the power supply is cut off. The above is the automatic reset temperature controller protection. The second time can be, for example, 10 minutes.

[0023] When the self-reset temperature controller fails, the temperature continues to rise when the fan equipment connected with the electric heating tube is blocked or the motor is stuck, the manual reset temperature rises to the set value of the manual reset temperature controller, the manual reset temperature controller is disconnected, the AC contactor KM is disconnected, and the power supply is cut off. The above is the manual reset temperature controller protection.

[0024] In another embodiment of the application, an electric heating tube explosion-proof early warning device is provided. After the first start, the standard value of the circuit current is detected by three mutual inductors. When any mutual inductor detects that the current I in the circuit is greater than or equal to the standard value*K1, the corresponding alarm indicator blinks 3 seconds / second, K1 is 1.2-2, and an alarm buzzer is sounded. When the abnormality is eliminated, the power is turned off, and the reset is performed after restarting.

[0025] At the same time, after the first start, the standard value of the circuit current is detected by three mutual inductors. When any mutual inductor detects that the current I in the circuit is less than or equal to the standard value*K2, the corresponding alarm indicator blinks 3 seconds / second, K2 is 0.3-0.8, and an alarm buzzer is sounded. When the abnormality is eliminated, the power is turned off, and the reset is performed after restarting.

[0026] Further, in an embodiment of the application, an electric heating tube explosion-proof early warning device is provided. As the electric heating tube increases with the working time, the power will decay, thereby causing the resistance to increase to the default value set before leaving the factory. When the resistance increases to the set value, the resistance sensor RH acquires the resistance value of the electric heating tube in real time during the working process. The size relationship between the resistance value and the resistance threshold value controls the on-off state of the fan and / or the contact of the AC contactor.

[0027] Specifically, controlling the on-off state of the cooling mechanism and / or the contact of the AC contactor according to the size relationship between the resistance value and the resistance threshold value can include: if the resistance value is greater than the resistance threshold value, controlling the contact of the AC contactor to be disconnected, and controlling the fan to continue to operate for a preset time length and then cut off the power supply.

[0028] The above setting of the heat pipe explosion-proof early warning device enables the electric heating tube to have the automatic reset temperature controller protection function and the manual reset temperature controller protection function during use, and also has the electric heating tube explosion-proof prediction and early warning function, thereby greatly improving the safety and effectiveness of the electric heating tube.

[0029] It is to be understood that the example embodiments described herein are illustrative rather than limiting. Although one or more embodiments of the application are described in connection with the accompanying drawings, it will be understood that various modifications in form and detail can be made without departing from the spirit and scope of the application as defined by the appended claims.

Claims

1. An explosion-proof early warning device for an electrothermal tube, characterized in that, The three-way circuit breaker QS, the three-way fuse FU, the three-way AC contactor KM, the three-way AC current transformer LH1, LH2 and LH3, the self-resetting temperature controller, the manual reset temperature controller, the current detection controller, the resistance sensor RH, the power switch SA1, the heating signal control switch SA2, the motor M and the capacitor C, wherein one end of the three-way circuit breaker QS is connected with the 380V live line three-phase input end L1, L2 and L3, the other end of the three-way circuit breaker QS is connected with one end of the three-way fuse FU, the other end of the three-way fuse FU is connected with one end of the three-way AC contactor KM, the other end of the three-way AC contactor KM is connected with one end of the Y-type three-phase electric heating tube R1, R2 and R3 through the three-way current transformer LH1, LH2 and LH3, one terminal of the three-way current transformer LH1, LH2 and LH3 is connected with three input ends of the current detection controller, the 380V zero line N input end is connected with one end of the self-resetting temperature controller, one end of the power indicator lamp and one input end of the current detection controller, the other end of the self-resetting temperature controller is connected with one end of the manual reset temperature controller, the other end of the manual reset temperature controller is connected with the coil one contact point of the KM, the other contact point of the KM coil is connected with the P1 input end of the current detection controller, the other end of the fuse of the live line L3 is connected with one end of the power switch, the other end of the power switch is connected with the other end of the power indicator lamp, the live line input end of the current detection controller and one input end of the heating signal control switch SA2, the other end of the heating signal control switch SA2 is connected with the P2 input end of the current detection controller, three output ends of the current detection controller are connected with the L1 alarm indicator lamp, the L2 alarm indicator lamp and the L3 alarm indicator lamp, the heating signal control switch SA2 is connected with the signal port of the digital display temperature controller or the ring temperature controller; four lead wires are arranged on the motor M, two of which are connected with the capacitor, and the other two are connected with the fan signal port in the integrated electric control cabinet. The resistance sensor RH acquires the resistance value of the electric heating tube in real time. The switching state of the fan and / or the contact point of the AC contactor is controlled according to the size relationship between the resistance value and the resistance threshold value, including: if the resistance value is greater than the resistance threshold value, the contact point of the AC contactor is controlled to be disconnected, and the fan is controlled to continue running for a preset time length, and then the power supply is cut off.

2. The electric heating tube explosion-preventing early-warning device according to claim 1, characterized in that, During the factory inspection, the voltage of the equipment to which the electric heating tube belongs is adjusted to the rated voltage through the voltage regulator, and in the power-on state, after a period of stable operation, the resistance value and the current of the equipment are detected, and the detected resistance value and current value are set as the standard value.

3. The electric heating tube explosion-preventing early-warning device according to claim 2, characterized in that, When the fan equipment connected with the electric heating tube is blocked or the motor is stuck, after the self-resetting temperature rises to the set value, the self-resetting temperature controller is disconnected, so that the AC contactor is disconnected, and the fan equipment for heat dissipation of the electric heating tube is cut off after a second time delay.

4. The electric heating tube explosion-preventing early-warning device according to claim 2, characterized in that, When the self-resetting temperature controller fails, the fan equipment connected with the electric heating pipe is blocked or the motor is stuck, the temperature continues to rise, and after the manually reset temperature rises to the set value of the manually reset temperature controller, the manually reset temperature controller is disconnected, so that the AC contactor KM is disconnected, and the power supply is cut off.

5. The electric heating tube explosion warning device according to claim 2, wherein the electric heating tube is a heating tube for a vehicle. After the first start, the standard value of the circuit current is detected by the three mutual inductors, and when any mutual inductor detects that the current I in the circuit is greater than or equal to the standard value*K1, the corresponding alarm indicator blinks 3 seconds / time, K1 is 1.2-2, and an alarm buzzer is sounded. When the abnormality is eliminated, power off, restart and reset.

6. The electric heating tube explosion warning device according to claim 2, wherein the electric heating tube is a heating tube for a vehicle. After the first start, the standard value of the circuit current is detected by the three mutual inductors, and when any mutual inductor detects that the current I in the circuit is greater than or equal to the standard value*K1, the corresponding alarm indicator blinks 3 seconds / time, K1 is 1.2-2, and an alarm buzzer is sounded. When the abnormality is eliminated, power off, restart and reset.

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